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Kratochvíla J, Jiřík R, Bartoš M, Standara M, Starčuk Z, Taxt T. Blind deconvolution decreases requirements on temporal resolution of DCE-MRI: Application to 2nd generation pharmacokinetic modeling. Magn Reson Imaging 2024; 109:238-248. [PMID: 38508292 DOI: 10.1016/j.mri.2024.03.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 03/08/2024] [Accepted: 03/16/2024] [Indexed: 03/22/2024]
Abstract
PURPOSE Dynamic Contrast-Enhanced (DCE) MRI with 2nd generation pharmacokinetic models provides estimates of plasma flow and permeability surface-area product in contrast to the broadly used 1st generation models (e.g. the Tofts models). However, the use of 2nd generation models requires higher frequency with which the dynamic images are acquired (around 1.5 s per image). Blind deconvolution can decrease the demands on temporal resolution as shown previously for one of the 1st generation models. Here, the temporal-resolution requirements achievable for blind deconvolution with a 2nd generation model are studied. METHODS The 2nd generation model is formulated as the distributed-capillary adiabatic-tissue-homogeneity (DCATH) model. Blind deconvolution is based on Parker's model of the arterial input function. The accuracy and precision of the estimated arterial input functions and the perfusion parameters is evaluated on synthetic and real clinical datasets with different levels of the temporal resolution. RESULTS The estimated arterial input functions remained unchanged from their reference high-temporal-resolution estimates (obtained with the sampling interval around 1 s) when increasing the sampling interval up to about 5 s for synthetic data and up to 3.6-4.8 s for real data. Further increasing of the sampling intervals led to systematic distortions, such as lowering and broadening of the 1st pass peak. The resulting perfusion-parameter estimation error was below 10% for the sampling intervals up to 3 s (synthetic data), in line with the real data perfusion-parameter boxplots which remained unchanged up to the sampling interval 3.6 s. CONCLUSION We show that use of blind deconvolution decreases the demands on temporal resolution in DCE-MRI from about 1.5 s (in case of measured arterial input functions) to 3-4 s. This can be exploited in increased spatial resolution or larger organ coverage.
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Affiliation(s)
- Jiří Kratochvíla
- Czech Academy of Sciences, Institute of Scientific Instruments, Královopolská 147, 612 64 Brno, Czech Republic.
| | - Radovan Jiřík
- Czech Academy of Sciences, Institute of Scientific Instruments, Královopolská 147, 612 64 Brno, Czech Republic
| | - Michal Bartoš
- Czech Academy of Sciences, Institute of Information Technology and Automation, Pod Vodárenskou věží 4, 182 08 Praha 8, Czech Republic
| | - Michal Standara
- Department of Radiology, Masaryk Memorial Cancer Institute, Žlutý kopec 7, 656 53 Brno, Czech Republic
| | - Zenon Starčuk
- Czech Academy of Sciences, Institute of Scientific Instruments, Královopolská 147, 612 64 Brno, Czech Republic
| | - Torfinn Taxt
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, Bergen, Norway
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Psarris G, Eleftheriadis N, Sidiras C, Sereti A, Iliadou VM. Temporal resolution and pitch discrimination in music education: novel data in children. Eur Arch Otorhinolaryngol 2024:10.1007/s00405-024-08571-7. [PMID: 38573511 DOI: 10.1007/s00405-024-08571-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 02/19/2024] [Indexed: 04/05/2024]
Abstract
BACKGROUND Rehabilitation of hearing and listening difficulties through neuroplasticity of the auditory nervous system is a promising technique. Evidence of enhanced auditory processing in adult musicians is often not based on clinical auditory processing tests and is lacking in children with musical education. PURPOSE The aim of this study is to investigate the temporal resolution and frequency discrimination elements of auditory processing both in adults and children with musical education and to compare them with those without any musical education. METHODS Participants consisted of ten children without musical training and ten children with musical training with mean age 11.3 years and range 8-15 years as well as ten adults without musical education and ten adults with musical education with mean age 38.1 years and range 30-45 years. All participants were tested with two temporal resolution tests (GIN:Gaps-In-Noise and RGDT:Random Gap Detection Test), a temporal ordering frequency test (FPT:Frequency Pattern Test), and a frequency discrimination test (DLF: Different Limen for Frequency). RESULTS All test results revealed better performance in both children and adults with musical training for both ears. CONCLUSION A positive effect of formal music education for specific auditory processing elements in both children and adults is documented. Larger samples, longitudinal studies, as well as groups with impaired hearing and/or auditory processing are needed to further substantiate the effect shown.
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Affiliation(s)
- Georgios Psarris
- School of Medicine, Aristotle University of Thessaloniki, 54124, Thessaloníki, Greece
| | | | - Christos Sidiras
- School of Medicine, Aristotle University of Thessaloniki, 54124, Thessaloníki, Greece
| | - Afroditi Sereti
- School of Medicine, Aristotle University of Thessaloniki, 54124, Thessaloníki, Greece
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Singhal I, Srinivasan N. Temporal correspondence in perceptual organization: Reciprocal interactions between temporal sensitivity and figure-ground segregation. Psychon Bull Rev 2024; 31:819-827. [PMID: 37726597 DOI: 10.3758/s13423-023-02373-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2023] [Indexed: 09/21/2023]
Abstract
How do visual representations account for time? Is it the case that they represent time by themselves possessing temporal properties (temporal mirroring) or by atemporal markers/tags (temporal tagging)? This question has been asked for the past 5 decades and more, in neuroscience, philosophy, and psychology. To address this debate, we designed a study to test temporal correspondence. We tested whether a temporal property (flicker frequency) could influence figure-ground segregation, and in turn, reciprocally, whether a figure-ground segregation would alter a temporal property (here, temporal resolution). We manipulated flicker frequency of dots on either side of an ambiguous edge in Experiment 1 and asked participants to indicate the figural region. In Experiment 2, we measured temporal sensitivity using a temporal order judgment (TOJ) task in both figural and ground regions. We showed temporal correspondence by showing specifically that figure-ground segregation depends on flicker frequency differences between two regions in ambiguous displays, where slow-flickering regions are seen as figural (Experiment 1). Reciprocally, in Experiment 2, we showed that participants performed a temporal-order judgment task better when the task had to be performed on a region seen as background compared with the same region seen as a figure. We show how relatively slower flickering regions are seen as figural, and correspondingly, seeing a region as figural is associated with a poorer temporal resolution. Our results collectively allow us to demonstrate a tight temporal correspondence in figure-ground perception, which could be explained using the parvocellular and magnocellular pathways, the two major retino-geniculo-cortical pathways.
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Affiliation(s)
- Ishan Singhal
- Department of Cognitive Science, Indian Institute of Technology Kanpur, Kanpur, 208106, India
| | - Narayanan Srinivasan
- Department of Cognitive Science, Indian Institute of Technology Kanpur, Kanpur, 208106, India.
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Monnin P, Rotzinger D, Viry A, Vitzthum V, Racine D. Assessment of temporal resolution and detectability of moving objects in CT: A task-based image quality study. Phys Med 2024; 120:103337. [PMID: 38552274 DOI: 10.1016/j.ejmp.2024.103337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 03/12/2024] [Accepted: 03/25/2024] [Indexed: 04/19/2024] Open
Abstract
The metrics used for assessing image quality in computed tomography (CT) do not integrate the influence of temporal resolution. A shortcoming in the assessment of image quality for imaging protocols where motion blur can therefore occur. We developed a method to calculate the temporal resolution of standard CT protocols and introduced a specific spatiotemporal formulation of the non-prewhitening with eye filter (NPWE) model observer to assess the detectability of moving objects as a function of their speed. We scanned a cubic water phantom with a plexiglass cylindrical insert (120 HU) using a large panel of acquisition parameters (rotation times, pitch factors and collimation widths) on two systems (GE Revolution Apex and Siemens SOMATOM Force) to determine the in-plane task-based transfer functions (TTF) and noise power spectra (NPS). The phantom set in a uniform rectilinear motion in the transverse plane allowed the temporal modulation transfer function (MTF) calculation. The temporal MTF appropriately compared the temporal resolution of the various acquisition protocols. The longitudinal TTF was measured using a thin tungsten wire. The detectability index showed the advantage of applying high rotation speed, wide collimations and high pitch for object detection in the presence of motion. No counterpart to the increase in these three parameters was found in the in-plane and longitudinal image quality.
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Affiliation(s)
- P Monnin
- Institute of Radiation Physics (IRA), Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Rue du Grand-Pré 1, 1007 Lausanne, Switzerland.
| | - D Rotzinger
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Rue du Bugnon 46, 1011 Lausanne, Switzerland
| | - A Viry
- Institute of Radiation Physics (IRA), Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Rue du Grand-Pré 1, 1007 Lausanne, Switzerland
| | - V Vitzthum
- Institute of Radiation Physics (IRA), Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Rue du Grand-Pré 1, 1007 Lausanne, Switzerland
| | - D Racine
- Institute of Radiation Physics (IRA), Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Rue du Grand-Pré 1, 1007 Lausanne, Switzerland
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Auad Y, Baaboura J, Blazit JD, Tencé M, Stéphan O, Kociak M, Tizei LHG. Time calibration studies for the Timepix3 hybrid pixel detector in electron microscopy. Ultramicroscopy 2024; 257:113889. [PMID: 38056397 DOI: 10.1016/j.ultramic.2023.113889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 11/13/2023] [Accepted: 11/23/2023] [Indexed: 12/08/2023]
Abstract
Direct electron detection is currently revolutionizing many fields of electron microscopy due to its lower noise, its reduced point-spread function, and its increased quantum efficiency. More specifically to this work, Timepix3 is a hybrid-pixel direct electron detector capable of outputting temporal information of individual hits in its pixel array. Its architecture results in a data-driven detector, also called event-based, in which individual hits trigger the data off the chip for readout as fast as possible. The presence of a pixel threshold value results in an almost readout-noise-free detector while also defining the hit time of arrival and the time the signal stays over the pixel threshold. In this work, we have performed various experiments to calibrate and correct the Timepix3 temporal information, specifically in the context of electron microscopy. These include the energy calibration, and the time-walk and pixel delay corrections, reaching an average temporal resolution throughout the entire pixel matrix of 1.37±0.04ns. Additionally, we have also studied cosmic rays tracks to characterize the charge dynamics along the volume of the sensor layer, allowing us to estimate the limits of the detector's temporal response depending on different bias voltages, sensor thickness, and the electron beam ionization volume. We have estimated the uncertainty due to the ionization volume ranging from about 0.8 ns for 60 keV electrons to 8.8 ns for 300 keV electrons.
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Affiliation(s)
- Yves Auad
- Laboratoire des Physique des Solides, Université Paris Saclay, Orsay, France.
| | - Jassem Baaboura
- Laboratoire des Physique des Solides, Université Paris Saclay, Orsay, France
| | - Jean-Denis Blazit
- Laboratoire des Physique des Solides, Université Paris Saclay, Orsay, France
| | - Marcel Tencé
- Laboratoire des Physique des Solides, Université Paris Saclay, Orsay, France
| | - Odile Stéphan
- Laboratoire des Physique des Solides, Université Paris Saclay, Orsay, France
| | - Mathieu Kociak
- Laboratoire des Physique des Solides, Université Paris Saclay, Orsay, France
| | - Luiz H G Tizei
- Laboratoire des Physique des Solides, Université Paris Saclay, Orsay, France
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Sartoretti T, Mergen V, Dzaferi A, Allmendinger T, Manka R, Alkadhi H, Eberhard M. Effect of temporal resolution on calcium scoring: insights from photon-counting detector CT. Int J Cardiovasc Imaging 2024:10.1007/s10554-024-03070-6. [PMID: 38389028 DOI: 10.1007/s10554-024-03070-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 02/13/2024] [Indexed: 02/24/2024]
Abstract
To intra-individually investigate the variation of coronary artery calcium (CAC), aortic valve calcium (AVC), and mitral annular calcium (MAC) scores and the presence of blur artifacts as a function of temporal resolution in patients undergoing non-contrast cardiac CT on a dual-source photon counting detector (PCD) CT. This retrospective, IRB-approved study included 70 patients (30 women, 40 men, mean age 78 ± 9 years) who underwent ECG-gated cardiac non-contrast CT with PCD-CT (gantry rotation time 0.25 s) prior to transcatheter aortic valve replacement. Each scan was reconstructed at a temporal resolution of 66 ms using the dual-source information and at 125 ms using the single-source information. Average heart rate and heart rate variability were calculated from the recorded ECG. CAC, AVC, and MAC were quantified according to the Agatston method on images with both temporal resolutions. Two readers assessed blur artifacts using a 4-point visual grading scale. The influence of average heart rate and heart rate variability on calcium quantification and blur artifacts of the respective structures were analyzed by linear regression analysis. Mean heart rate and heart rate variability during data acquisition were 76 ± 17 beats per minute (bpm) and 4 ± 6 bpm, respectively. CAC scores were smaller on 66 ms (median, 511; interquartile range, 220-978) than on 125 ms reconstructions (538; 203-1050, p < 0.001). Median AVC scores [2809 (2009-3952) versus 3177 (2158-4273)] and median MAC scores [226 (0-1284) versus 251 (0-1574)] were also significantly smaller on 66ms than on 125ms reconstructions (p < 0.001). Reclassification of CAC and AVC risk categories occurred in 4% and 11% of cases, respectively, whereby the risk category was always overestimated on 125ms reconstructions. Image blur artifacts were significantly less on 66ms as opposed to 125 ms reconstructions (p < 0.001). Intra-individual analyses indicate that temporal resolution significantly impacts on calcium scoring with cardiac CT, with CAC, MAC, and AVC being overestimated at lower temporal resolution because of increased motion artifacts eventually leading to an overestimation of patient risk.
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Affiliation(s)
- Thomas Sartoretti
- Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland
| | - Victor Mergen
- Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland
| | - Amina Dzaferi
- Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland
| | | | - Robert Manka
- Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland
- Department of Cardiology, University Heart Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Hatem Alkadhi
- Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland
| | - Matthias Eberhard
- Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland.
- Radiology, Spital Interlaken, Spitäler fmi AG, Unterseen, Switzerland.
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Schmidt-Rimpler J, Backhaus SJ, Hartmann FP, Schaten P, Lange T, Evertz R, Schulz A, Kowallick JT, Lapinskas T, Hasenfuß G, Kelle S, Schuster A. Impact of temporal and spatial resolution on atrial feature tracking cardiovascular magnetic resonance imaging. Int J Cardiol 2024; 396:131563. [PMID: 37926379 DOI: 10.1016/j.ijcard.2023.131563] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 09/27/2023] [Accepted: 10/27/2023] [Indexed: 11/07/2023]
Abstract
BACKGROUND Myocardial deformation assessment by cardiovascular magnetic resonance-feature tracking (CMR-FT) has incremental prognostic value over volumetric analyses. Recently, atrial functional analyses have come to the fore. However, to date recommendations for optimal resolution parameters for accurate atrial functional analyses are still lacking. METHODS CMR-FT was performed in 12 healthy volunteers and 9 ischemic heart failure (HF) patients. Cine sequences were acquired using different temporal (20, 30, 40 and 50 frames/cardiac cycle) and spatial resolution parameters (high 1.5 × 1.5 mm in plane and 5 mm slice thickness, standard 1.8 × 1.8 × 8 mm and low 3.0 × 3.0 × 10 mm). Inter- and intra-observer reproducibility were calculated. RESULTS Increasing temporal resolution is associated with higher absolute strain and strain rate (SR) values. Significant changes in strain assessment for left atrial (LA) total strain occurred between 20 and 30 frames/cycle amounting to 2,5-4,4% in absolute changes depending on spatial resolution settings. From 30 frames/cycle onward, absolute strain values remained unchanged. Significant changes of LA strain rate assessment were observed up to the highest temporal resolution of 50 frames/cycle. Effects of spatial resolution on strain assessment were smaller. For LA total strain a general trend emerged for a mild decrease in strain values obtained comparing the lowest to the highest spatial resolution at temporal resolutions of 20, 40 and 50 frames/cycle (p = 0.006-0.046) but not at 30 frames/cycle (p = 0.140). CONCLUSION Temporal and to a smaller extent spatial resolution affect atrial functional assessment. Consistent strain assessment requires a standard spatial resolution and a temporal resolution of 30 frames/cycle, whilst SR assessment requires even higher settings of at least 50 frames/cycle.
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Affiliation(s)
- Jonas Schmidt-Rimpler
- University Medical Center Göttingen, Department of Cardiology and Pneumology, Georg-August University, Göttingen, Germany; University Medical Center Göttingen, Institute for Diagnostic and Interventional Radiology, Georg-August University, Göttingen, Germany
| | - Sören J Backhaus
- University Medical Center Göttingen, Department of Cardiology and Pneumology, Georg-August University, Göttingen, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
| | - Finn P Hartmann
- University Medical Center Göttingen, Department of Cardiology and Pneumology, Georg-August University, Göttingen, Germany
| | - Philip Schaten
- Graz University of Technology, Institute of Biomedical Imaging, Graz, Austria
| | - Torben Lange
- University Medical Center Göttingen, Department of Cardiology and Pneumology, Georg-August University, Göttingen, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
| | - Ruben Evertz
- University Medical Center Göttingen, Department of Cardiology and Pneumology, Georg-August University, Göttingen, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
| | - Alexander Schulz
- University Medical Center Göttingen, Department of Cardiology and Pneumology, Georg-August University, Göttingen, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
| | - Johannes T Kowallick
- University Medical Center Göttingen, Institute for Diagnostic and Interventional Radiology, Georg-August University, Göttingen, Germany
| | - Tomas Lapinskas
- German Heart Center Berlin (DHZB), University of Berlin, Department of Internal Medicine / Cardiology, Charité Campus Virchow Clinic, Berlin, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Germany; Department of Cardiology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Gerd Hasenfuß
- University Medical Center Göttingen, Department of Cardiology and Pneumology, Georg-August University, Göttingen, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
| | - Sebastian Kelle
- German Heart Center Berlin (DHZB), University of Berlin, Department of Internal Medicine / Cardiology, Charité Campus Virchow Clinic, Berlin, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Germany
| | - Andreas Schuster
- University Medical Center Göttingen, Department of Cardiology and Pneumology, Georg-August University, Göttingen, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany.
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Watkins A. Scaling procedures in climate science: Using temporal scaling to identify a paleoclimate analogue. Stud Hist Philos Sci 2023; 102:31-44. [PMID: 37804549 DOI: 10.1016/j.shpsa.2023.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 08/22/2023] [Accepted: 09/23/2023] [Indexed: 10/09/2023]
Abstract
Using past episodes of climate change as a source of evidence to inform our projections about contemporary climate change requires establishing the extent to which episodes in the deep past are analogous to the current crisis. However, many scientists claim that contemporary rates of climate change (e.g., rates of carbon emissions or temperature change) are unprecedented, including compared to episodes in the deep past. If so, this would limit the utility of paleoclimate analogues. In this paper, I show how a data adjustment procedure called "temporal scaling," which must be applied to both contemporary and past rate data, complicates the claim that contemporary rates are truly unprecedented. On top of giving actionable recommendations to scientists, this paper advances the philosophical literature concerning the use of models that are known to be somewhat disanalogous to their target systems.
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Affiliation(s)
- Aja Watkins
- University of Wisconsin-Madison; Madison, WI, USA.
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Zhang J, Xiong Z, Tian D, Hu S, Song Q, Li Z. Compressed sensing cine imaging with higher temporal resolution for analysis of left atrial strain and strain rate by cardiac magnetic resonance feature tracking. Jpn J Radiol 2023; 41:1084-1093. [PMID: 37067751 DOI: 10.1007/s11604-023-01433-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 04/10/2023] [Indexed: 04/18/2023]
Abstract
PURPOSE Cardiac magnetic resonance (CMR) feature tracking (FT) is more widely used in the measurement of left atrial (LA) strain and strain rate (SR). However, in recent years, researchers have attempted to improve the low temporal resolution of CMR-FT to better capture the subtle deformations of the myocardium. The technique of compressed sensing (CS) has been applied clinically, reducing scan time while increasing temporal resolution. The purpose of this study was to explore the effect of the increased temporal resolution of CS cine sequences on the analysis of LA longitudinal strain and SR. MATERIALS AND METHODS Twenty-nine healthy subjects were included in the study. They underwent CMR with a reference steady-state free precession cine sequence of conventional temporal resolution (standard SSFP sequence), a cine sequence of higher temporal resolution (HT sequence), and an HT cine sequence with CS (CS HT sequence) (temporal resolution: 22.1-44.3/24.9-47.1 ms, 11.1-19.4 ms, and 8.3-19.4 ms, respectively). The standard SSFP sequence, HT sequence, and CS HT sequence were acquired in all subjects during the same scanning session. LA longitudinal strain and SR, reflecting LA reservoir, conduit, and contraction booster-pump function, were measured by CMR-FT and compared among the three sequences. RESULTS The measurements of LASR reservoir, conduit, and booster-pump were significantly higher on the HT and CS HT sequences than on the standard SSFP sequence. The standard SSFP sequence was correlated significantly with the HT and CS HT sequences in terms of LA strain and SR analysis, respectively. The LA strain and SR measurements also showed excellent agreement between the HT and CS HT sequences. CONCLUSION Higher temporal resolution led to significantly higher measured LASR values in CMR-FT. Furthermore, the addition of CS reduced scan time and did not affect LA longitudinal strain or SR analysis.
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Affiliation(s)
- Jingyu Zhang
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, 222 Zhongshan Road, Xigang District, Dalian, 116011, China
| | - Ziqi Xiong
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, 222 Zhongshan Road, Xigang District, Dalian, 116011, China
| | - Di Tian
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, 222 Zhongshan Road, Xigang District, Dalian, 116011, China
| | - Shuai Hu
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, 222 Zhongshan Road, Xigang District, Dalian, 116011, China
| | - Qingwei Song
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, 222 Zhongshan Road, Xigang District, Dalian, 116011, China
| | - Zhiyong Li
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, 222 Zhongshan Road, Xigang District, Dalian, 116011, China.
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Wu H, Li G, Hou J, Sotthewes K. Probing surface properties of organic molecular layers by scanning tunneling microscopy. Adv Colloid Interface Sci 2023; 318:102956. [PMID: 37393823 DOI: 10.1016/j.cis.2023.102956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 06/21/2023] [Accepted: 06/23/2023] [Indexed: 07/04/2023]
Abstract
In view of the relevance of organic thin layers in many fields, the fundamentals, growth mechanisms, and dynamics of thin organic layers, in particular thiol-based self-assembled monolayers (SAMs) on Au(111) are systematically elaborated. From both theoretical and practical perspectives, dynamical and structural features of the SAMs are of great intrigue. Scanning tunneling microscopy (STM) is a remarkably powerful technique employed in the characterization of SAMs. Numerous research examples of investigation about the structural and dynamical properties of SAMs using STM, sometimes combined with other techniques, are listed in the review. Advanced options to enhance the time resolution of STM are discussed. Additionally, we elaborate on the extremely diverse dynamics of various SAMs, such as phase transitions and structural changes at the molecular level. In brief, the current review is expected to supply a better understanding and novel insights regarding the dynamical events happening in organic SAMs and how to characterize these processes.
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Affiliation(s)
- Hairong Wu
- State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum-Beijing, Beijing 102249, China; Unconventional Petroleum Research Institute, China University of Petroleum-Beijing, Beijing 102249, China.
| | - Genglin Li
- College of Science, China University of Petroleum-Beijing, Beijing 102249, China
| | - Jirui Hou
- State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum-Beijing, Beijing 102249, China; Unconventional Petroleum Research Institute, China University of Petroleum-Beijing, Beijing 102249, China
| | - Kai Sotthewes
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500AE Enschede, the Netherlands.
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Martín-Gabarrella A, Gemeno C, Belušič G. Spectral sensitivity of retinal photoreceptors of tortricid moths is not tuned to diel activity period. J Exp Biol 2023:jeb.245461. [PMID: 37416981 DOI: 10.1242/jeb.245461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 07/01/2023] [Indexed: 07/08/2023]
Abstract
Leafrollers (Lepidoptera: Tortricidae) are a large family of small moths containing over 10.000 species, many of which are crop pests. Grapholita molesta (Busck), Lobesia botrana (Denis & Schiffermüller) and Cydia pomonella (L.) adults are sexually active before, during and after sunset, respectively. We wanted to determine if being active at different times of the day and night is associated with differences in their visual system. Spectral sensitivity (SS) was measured with electroretinograms and selective adaptation with green, blue and ultraviolet light. SS curves could be fitted with a triple nomogram template which indicated the existence of three photoreceptor classes peaking at 355 nm, 440 nm and 525 nm. The retinae showed clear regionalization, with fewer blue receptors dorsally. No differences among species or between sexes were found. Intracellular recordings in C. pomonella revealed three photoreceptor classes with sensitivities peaking at 355 nm, 440 nm and 525 nm. The blue photoreceptors showed inhibitory responses in the green part of the spectrum, indicating the presence of a color-opponent system. Flicker fusion frequency experiments showed that the response frequency was similar between sexes and species at around 100 Hz. Our results indicate that the three species have the ancestral insect retinal substrate for a trichromatic color vision, based upon the UV, blue and green-sensitive photoreceptors, and lack any prominent adaptations related to being active under different light conditions.
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Affiliation(s)
- Alejandro Martín-Gabarrella
- University of Lleida, Department of Agricultural and Forest Sciences and Engineering, Agrotecnio-CERCA Center, Av. Alcalde Rovira Roure 191, 25198 Lleida, Spain
| | - César Gemeno
- University of Lleida, Department of Agricultural and Forest Sciences and Engineering, Agrotecnio-CERCA Center, Av. Alcalde Rovira Roure 191, 25198 Lleida, Spain
| | - Gregor Belušič
- Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia
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12
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Kılıç M, Kara E. Investigation of hearing aid users' speech understanding in noise and their spectral- temporal resolution skills. J Otol 2023; 18:146-151. [PMID: 37497328 PMCID: PMC10366584 DOI: 10.1016/j.joto.2023.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 04/01/2023] [Accepted: 04/22/2023] [Indexed: 07/28/2023] Open
Abstract
Purpose Our study aims to compare speech understanding in noise and spectral- temporal resolution skills with regard to the degree of hearing loss, age, hearing aid use experience and gender of hearing aid users. Methods Our study included sixty-eight hearing aid users aged between 40-70 years, with bilateral mild and moderate symmetrical sensorineural hearing loss. Random gap detection test, Turkish matrix test and spectral-temporally modulated ripple test were implemented on the participants with bilateral hearing aids. The test results acquired were compared statistically according to different variables and the correlations were examined. Results No statistically significant differences were observed for speech-in-noise recognition, spectral-temporal resolution among older and younger adults in hearing aid users (p>0.05). There wasn't found a statistically significant difference among test outcomes as regards different hearing loss degrees (p>0.05). Higher performances were obtained in terms of temporal resolution in male participants and participants with more hearing aid use experience (p<0.05). Significant correlations were obtained between the results of speech-in-noise recognition, temporal resolution and spectral resolution tests performed with hearing aids (p<0.05). Conclusion Our study findings emphasized the importance of regular hearing aid use and it showed that some auditory skills can be improved with hearing aids. Observation of correlations among the speech-in-noise recognition, temporal resolution and spectral resolution tests have revealed that these skills should be evaluated as a whole to maximize the patient's communication abilities.
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Affiliation(s)
- Mert Kılıç
- Istanbul University-Cerrahpaşa, Institute of Graduate Studies, Department of Audiology, Istanbul, Turkey
| | - Eyyup Kara
- Istanbul University-Cerrahpaşa, Faculty of Health Sciences, Department of Audiology, Istanbul, Turkey
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13
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El Sayed R, Sharifi A, Park CC, Haussen DC, Allen JW, Oshinski JN. Optimization of 4D Flow MRI Spatial and Temporal Resolution for Examining Complex Hemodynamics in the Carotid Artery Bifurcation. Cardiovasc Eng Technol 2023; 14:476-488. [PMID: 37156900 PMCID: PMC10524741 DOI: 10.1007/s13239-023-00667-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 04/24/2023] [Indexed: 05/10/2023]
Abstract
BACKGROUND Three-dimensional, ECG-gated, time-resolved, three-directional, velocity-encoded phase-contrast MRI (4D flow MRI) has been applied extensively to measure blood velocity in great vessels but has been much less used in diseased carotid arteries. Carotid artery webs (CaW) are non-inflammatory intraluminal shelf-like projections into the internal carotid artery (ICA) bulb that are associated with complex flow and cryptogenic stroke. PURPOSE Optimize 4D flow MRI for measuring the velocity field of complex flow in the carotid artery bifurcation model that contains a CaW. METHODS A 3D printed phantom model created from computed tomography angiography (CTA) of a subject with CaW was placed in a pulsatile flow loop within the MRI scanner. 4D Flow MRI images of the phantom were acquired with five different spatial resolutions (0.50-2.00 mm3) and four different temporal resolutions (23-96 ms) and compared to a computational fluid dynamics (CFD) solution of the flow field as a reference. We examined four planes perpendicular to the vessel centerline, one in the common carotid artery (CCA) and three in the internal carotid artery (ICA) where complex flow was expected. At these four planes pixel-by-pixel velocity values, flow, and time average wall shear stress (TAWSS) were compared between 4D flow MRI and CFD. HYPOTHESIS An optimized 4D flow MRI protocol will provide a good correlation with CFD velocity and TAWSS values in areas of complex flow within a clinically feasible scan time (~ 10 min). RESULTS Spatial resolution affected the velocity values, time average flow, and TAWSS measurements. Qualitatively, a spatial resolution of 0.50 mm3 resulted in higher noise, while a lower spatial resolution of 1.50-2.00 mm3 did not adequately resolve the velocity profile. Isotropic spatial resolutions of 0.50-1.00 mm3 showed no significant difference in total flow compared to CFD. Pixel-by-pixel velocity correlation coefficients between 4D flow MRI and CFD were > 0.75 for 0.50-1.00 mm3 but were < 0.5 for 1.50 and 2.00 mm3. Regional TAWSS values determined from 4D flow MRI were generally lower than CFD and decreased at lower spatial resolutions (larger pixel sizes). TAWSS differences between 4D flow and CFD were not statistically significant at spatial resolutions of 0.50-1.00 mm3 but were different at 1.50 and 2.00 mm3. Differences in temporal resolution only affected the flow values when temporal resolution was > 48.4 ms; temporal resolution did not affect TAWSS values. CONCLUSION A spatial resolution of 0.74-1.00 mm3 and a temporal resolution of 23-48 ms (1-2 k-space segments) provides a 4D flow MRI protocol capable of imaging velocity and TAWSS in regions of complex flow within the carotid bifurcation at a clinically acceptable scan time.
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Affiliation(s)
- Retta El Sayed
- Department of Biomedical Engineering, The Wallace H. Coulter, Emory University and Georgia Institute of Technology, Atlanta, GA, USA
| | - Alireza Sharifi
- Department of Radiology & Imaging Sciences, Emory University, 1364 Clifton Rd, Atlanta, GA, 30322, USA
| | - Charlie C Park
- Department of Radiology & Imaging Sciences, Emory University, 1364 Clifton Rd, Atlanta, GA, 30322, USA
| | | | - Jason W Allen
- Department of Biomedical Engineering, The Wallace H. Coulter, Emory University and Georgia Institute of Technology, Atlanta, GA, USA
- Department of Radiology & Imaging Sciences, Emory University, 1364 Clifton Rd, Atlanta, GA, 30322, USA
- Department of Neurology, Emory University, Atlanta, GA, USA
| | - John N Oshinski
- Department of Biomedical Engineering, The Wallace H. Coulter, Emory University and Georgia Institute of Technology, Atlanta, GA, USA.
- Department of Radiology & Imaging Sciences, Emory University, 1364 Clifton Rd, Atlanta, GA, 30322, USA.
- Department of Neurology, Emory University, Atlanta, GA, USA.
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14
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Chen J, Tang M, Wang JQ, Chen C, Zhou Y, Lu GM, Zhang LJ. Influence of temporal resolution on computed tomography feature-tracking strain measurements. Eur J Radiol 2023; 158:110644. [PMID: 36525702 DOI: 10.1016/j.ejrad.2022.110644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 11/14/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022]
Abstract
PURPOSE Temporal resolution significantly affects strain values demonstrated by Magnetic resonance feature-tracking and speckle-tracking echocardiography. We investigated the influence of R-R interval reconstruction increments on left ventricular (LV) and left atrial (LA) strain measurements of Computed tomography feature-tracking (CT-FT). METHODS Subjects who underwent retrospective electrocardiogram-gated coronary CT angiography (CCTA) were retrospectively included, and CCTA images were reconstructed in 5% and 10% steps throughout the entire cardiac cycle (0-100% R-R interval). LV global longitudinal strain (GLS), circumferential strain (GCS), radial strain (GRS), LA GLS, ejection fraction (EF), and left atrioventricular coupling indices were computed. We evaluated the consistency and variability of continuous variables between the two reconstruction increment groups, the demarcation between the LA conduit and contraction phases, and observer reproducibility in 20 randomly selected participants. RESULTS Eighty-one participants with or without cardiac disease were included. The reconstruction increment of the R-R interval significantly affected the CT-FT-derived strain values. The 5% R-R increment resulted in significantly larger absolute strain values. LV GRS had the greatest difference between the two groups. In the subgroups with heart rates greater than 80 beats per minute or impaired cardiac function, group differences were attenuated, especially for LV GLS, LV GRS, and LA GLS. The prevalence of definite demarcation between the LA conduit and contraction phases was significantly higher in the 5% R-R reconstruction increment group than in the 10% R-R reconstruction increment group. The average heart rate during CCTA scanning was a strong risk factor for indefinite demarcation, which is independent of LVEF. As average heart rate increased, so did the incidence of indefinite demarcation between the LA conduit and contraction phases. The observer reproducibility of LV and LA strain values was independent of the R-R reconstruction increment. CONCLUSION Reconstruction increment of the R-R interval is an important source of variation in LV and LA CT-FT strain values, especially with low heart rate and preserved cardiac function. It is essential to control the heart rate and apply a narrow R-R reconstruction increment to quantify phasic LA strain.
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15
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Long Z, Pan Z, Jin X, Zou Q, He J, Li W, Waters CN, Turner SD, do Sul JAI, Yu X, Chen J, Lin H, Ren J. Anthropocene microplastic stratigraphy of Xiamen Bay, China: A history of plastic production and waste management. Water Res 2022; 226:119215. [PMID: 36240710 DOI: 10.1016/j.watres.2022.119215] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 09/13/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Microplastics (MPs) are considered one of the significant stratigraphic markers of the onset of the Anthropocene Epoch; however, the interconnections between historic plastic production, waste management as well as social-economic and timing of MP accumulation are not well understood. Here, stratigraphic data of MPs from a sediment core from Xiamen Bay, China, was used to reconstruct the history of plastic pollution. Generalized Additive Modeling indicates a complex temporal evolution of MP accumulation. The oldest MPs deposited in 1952 was 30,332 ± 31,457 items/kg•dw, coincide with the infancy of the plastic industry and onset of the Anthropocene. The Cultural Revolution (1966-1976) curtailed these initial increases. Subsequent rapid growth in MPs during the late 1970s was peaked at 189,241 ± 29,495 items/kg•dw in 1988 and was followed by a drastic decline in the late 1980s to a low value in 1996 (16,626 ± 26,371 items/kg•dw), coinciding with proliferation of MP sources, coupled with evolution of plastic production, consumption, and regulation. Increasing MPs over the past decades implies that previous mitigation measures have been compromised by the escalated influx of MPs from increasing plastics production, legacy MPs remaining in circulation and insufficient waste management for a growing population. The present methodology and results represent a conceptual advance in understanding how changes in policy and economics over time correlate to changes in MP records in Anthropocene strata, which may help make decisions on plastic pollution mitigation strategies worldwide.
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Affiliation(s)
- Zouxia Long
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China; College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan 430074, China
| | - Zhong Pan
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China.
| | - Xianglong Jin
- Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China; College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan 430074, China.
| | - Qingping Zou
- The Lyell Centre for Earth and Marine Science and Technology, Institute for Infrastructure and Environment, Heriot-Watt University, Edinburgh EH14 4AS, UK.
| | - Jianhua He
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
| | - Weiwen Li
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
| | - Colin N Waters
- School of Geography, Geology and the Environment, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - Simon D Turner
- Department of Geography, Environmental Change Research Centre, University College London, Gower Street, London WC1E 6BT, UK
| | - Juliana A Ivar do Sul
- Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Seestrasse 15, Rostock 18119 , Germany
| | - Xingguang Yu
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
| | - Jian Chen
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
| | - Hui Lin
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China.
| | - Jianye Ren
- College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan 430074, China.
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Nakamura T, Murakami I. Temporal resolution and temporal extent of orientation repulsion. Vision Res 2022; 200:108104. [PMID: 35878472 DOI: 10.1016/j.visres.2022.108104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 06/24/2022] [Accepted: 07/12/2022] [Indexed: 01/25/2023]
Abstract
A vertical target is perceived as tilted against a slightly tilted inducer surrounding it. To identify the temporal resolution and temporal extent of this phenomenon of orientation repulsion in the same paradigm, we used an alternating pair of inducer stimuli having complementary orientation distributions and quantified repulsion at various alternation frequencies. The duration of each inducer stimulus was inversely proportional to the frequency. When an orthogonal pair of D2 patterns, a type of grating whose luminance modulation in a particular orientation was the second-order partial derivative of an isotropic 2D-Gaussian, was used as the inducer, repulsion occurred when the duration exceeded 20 ms and leveled off at 30 ms and beyond. When a custom-made texture with a narrowband orientation distribution and another texture with a complementary orientation distribution were alternated as the inducer, repulsion gradually increased until the inducer duration reached 200 ms. The gradual increase in repulsion was observed regardless of whether the orientation of the inducer that appeared simultaneously with the target was discernible. These findings reveal that contextual modulation in orientation occurs at a high temporal resolution and continues to a long temporal extent under optimal conditions.
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Affiliation(s)
- Tomoya Nakamura
- Department of Psychology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083, Japan.
| | - Ikuya Murakami
- Department of Psychology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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17
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Shibuya S, Oosone H, Ohki Y. Tactile temporal order judgment during rubber hand illusion: Distinct modulation of the point of subjective simultaneity and temporal resolution. Conscious Cogn 2022; 105:103402. [PMID: 36067686 DOI: 10.1016/j.concog.2022.103402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 08/10/2022] [Accepted: 08/24/2022] [Indexed: 01/27/2023]
Abstract
During the rubber hand illusion (RHI), individuals feel a fake hand as their own (ownership) and a perceived position of their real hand shifts toward the fake hand (proprioceptive drift; PD), which represents updating of multisensory hand representations. Bimanual tactile temporal order judgment (TOJ) includes processes of localizing tactile stimuli in space, for which multisensory hand representations are essential. According to the common processes, we examined tactile TOJ performance during the RHI and non-RHI. Temporal resolution (TR) as TOJ accuracy worsened during the non-RHI compared to the RHI. Additionally, a significant correlation between TR and PD was observed only in the non-RHI condition. However, the point of subjective simultaneity (PSS), which offers relative weighting of tactile inputs from the right and left hands, was correlated with illusory hand ownership. These results suggest that PSS and TR from tactile TOJ during RHI relate to self-attribution and localization of the hand, respectively.
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Affiliation(s)
- Satoshi Shibuya
- Department of Integrative Physiology, School of Medicine, Kyorin University, 6-20-2 Shinkawa, Mitaka, Tokyo 181-8611, Japan.
| | - Hiroki Oosone
- Chiba Minato Rehabilitation Hospital, 1-17-18 Chuo-minato, Chuo-ku, Chiba City, Chiba 260-0024, Japan
| | - Yukari Ohki
- Department of Integrative Physiology, School of Medicine, Kyorin University, 6-20-2 Shinkawa, Mitaka, Tokyo 181-8611, Japan
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18
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Sugimoto F, Kimura M, Takeda Y. Investigation of the optimal time interval between task-irrelevant auditory probes for evaluating mental workload in the shortest possible time. Int J Psychophysiol 2022; 177:103-110. [PMID: 35513137 DOI: 10.1016/j.ijpsycho.2022.04.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 04/27/2022] [Accepted: 04/30/2022] [Indexed: 10/18/2022]
Abstract
Event-related brain potentials (ERPs) elicited by auditory stimuli unrelated to a current visual-cognitive task (i.e., task-irrelevant auditory probes) can be used to evaluate the level of mental workload. Towards the evaluation of workload in the shortest possible time, the present study with a multiple-stimulus paradigm (Takeda and Kimura, 2014, Int. J. Psychophysiol.) examined whether manipulating time intervals between probes could improve the temporal resolution in evaluating workload. Probes were presented in four interval conditions as a combination of two mean interval lengths [long (600 ms) vs. short (300 ms)] and two interval variabilities [variable (five levels) vs. fixed], while participants were performing a driving game at slow and fast speeds (i.e., imposing low and high workload, respectively). For each interval condition, the minimum data length required to obtain a significant difference in the amplitude of ERPs (i.e., auditory N1 and P2) between the slow and fast driving tasks was estimated. The N1 difference was significant in all four interval conditions but the required minimum data lengths to observe this difference did not greatly differ across the interval conditions (about 60-90 s). The P2 difference was significant only in the long-variable condition and the required minimum data length was about 120 s. These results suggest that, at least with a multiple-stimulus paradigm, manipulations of time intervals between probes did not greatly improve the temporal resolution in evaluating mental workload; at present, long-variable intervals would be optimal for evaluating mental workload in detail.
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Affiliation(s)
- Fumie Sugimoto
- National Institute of Advanced Industrial Science and Technology (AIST), Japan.
| | - Motohiro Kimura
- National Institute of Advanced Industrial Science and Technology (AIST), Japan
| | - Yuji Takeda
- National Institute of Advanced Industrial Science and Technology (AIST), Japan
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19
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Umesawa Y, Ide M, Wada M. The relationship between the effect of hand visibility on visuotactile temporal resolution and autistic traits. Exp Brain Res 2022; 240:1557-1564. [PMID: 35391582 DOI: 10.1007/s00221-022-06347-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 03/10/2022] [Indexed: 11/28/2022]
Abstract
Individuals with autism spectrum disorder (ASD) have atypical sensory processing, particularly when sensory stimuli are delivered from different modalities with a temporal lag of subseconds. Previous studies have suggested that individuals with ASD require a longer temporal lag to judge temporal orders of successive audiovisual stimuli than neurotypical individuals; however, it remains unclear whether a lower temporal resolution in the visuotactile domain is associated with an individual's autistic traits. In addition, a previous study demonstrated that visuotactile temporal resolution degraded when the participants saw a hand image on a display. In this study, we investigated whether the temporal resolution of the visuotactile stimuli degrades when the participant's own hand or rubber hands are visible, and whether the effect of the hand's visibility on the temporal resolution decreases according to an individual's autistic traits. We used the temporal order judgment (TOJ) of the vibrotactile stimulus delivered to the participant's index finger and an LED attached above their own hand or rubber hand. Our findings suggest that when participants could not see their hand, temporal order judgment tended to be coarser in participants with higher autistic traits. However, this tendency was not observed when they could see both their own or the rubber hands. Moreover, temporal resolution degraded when the participants could see their own hands. These results indicate that autistic traits influence the temporal resolution of visuotactile stimuli if they are delivered as external signals in TOJ.
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Affiliation(s)
- Yumi Umesawa
- Developmental Disorders Section, Department of Rehabilitation for Brain Functions, Research Institute of National Rehabilitation Center for Persons with Disabilities, 4-1, Namiki, Tokorozawa-shi, Saitama, 359-8555, Japan
| | - Masakazu Ide
- Developmental Disorders Section, Department of Rehabilitation for Brain Functions, Research Institute of National Rehabilitation Center for Persons with Disabilities, 4-1, Namiki, Tokorozawa-shi, Saitama, 359-8555, Japan.
| | - Makoto Wada
- Developmental Disorders Section, Department of Rehabilitation for Brain Functions, Research Institute of National Rehabilitation Center for Persons with Disabilities, 4-1, Namiki, Tokorozawa-shi, Saitama, 359-8555, Japan
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Abstract
Impaired temporal resolution of the central auditory system has long been suggested to contribute to speech understanding deficits in the elderly. However, it has been difficult to differentiate between direct age-related central deficits and indirect effects of confounding peripheral age-related hearing loss on temporal resolution. To differentiate this, we measured temporal acuity in the inferior colliculus (IC) of aged CBA/J and C57BL/6 mice, as a model of aging with and without concomitant hearing loss. We used two common measures of auditory temporal processing: gap detection as a measure of temporal fine structure and amplitude-modulated noise as a measure of envelope sensitivity. Importantly, auditory temporal acuity remained precise in the IC of old CBA/J mice when no or only minimal age-related hearing loss was present. In contrast, temporal acuity was only indirectly reduced by the presence of age-related hearing loss in aged C57BL/6 mice, not by affecting the brainstem precision, but by affecting the signal-to-noise ratio of the neuronal activity in the IC. This demonstrates that indirect effects of age-related peripheral hearing loss likely remain an important factor for temporal processing in aging in comparison to 'pure' central auditory decline itself. It also draws attention to the issue that the threshold difference between 'nearly normal' or 'clinically normal' hearing aging subjects in comparison to normal hearing young subjects still can have indirect effects on central auditory neural representations of temporal processing.
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Affiliation(s)
- Rüdiger Land
- Department of Experimental Otology, Institute for Audioneurotechnology, Hannover Medical School, Hannover, Lower Saxony, Germany.
| | - Andrej Kral
- Department of Experimental Otology, Institute for Audioneurotechnology, Hannover Medical School, Hannover, Lower Saxony, Germany; Department of Biomedical Sciences, School of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
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Abdo A, Zamoun M, Vasile T, Bailly MT, El Hatimi S, Bellin MF, Meyrignac O. Right ventricular shotgun pellet embolism: Case report and radiological aspect. Radiol Case Rep 2021; 16:3172-3175. [PMID: 34484513 PMCID: PMC8405947 DOI: 10.1016/j.radcr.2021.07.060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 07/25/2021] [Accepted: 07/25/2021] [Indexed: 11/21/2022] Open
Abstract
Pellet embolism to the heart following gunshot injuries is an unusual event that requires a fast diagnosis. Imaging assessment is necessary to locate the projectiles and look for associated injuries. We present a case of a 41-year-old woman admitted after sustaining 2 gunshot wounds in the abdomen and left thigh, with the initial computed tomography (CT) scan showing a metallic object next to the right ventricle. Further radiological evaluation included transthoracic echocardiography and electrocardiogram-gated cardiac CT scan which confirmed the diagnosis of a migrating pellet to the right ventricle, entrapped within the trabeculations. Electrocardiogram-gated cardiac CT has a major role in detailed evaluation of bullet embolism to the heart cavities and guides the management.
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Affiliation(s)
- Alain Abdo
- Radiology department, Bicetre Hospital APHP, 78 Rue du Général Leclerc, Le Kremlin Bicetre 94270, France
| | - Mylene Zamoun
- Radiology department, Bicetre Hospital APHP, 78 Rue du Général Leclerc, Le Kremlin Bicetre 94270, France
| | - Teodor Vasile
- Radiology department, Bicetre Hospital APHP, 78 Rue du Général Leclerc, Le Kremlin Bicetre 94270, France
| | - Minh Tam Bailly
- Cardiology department, Bicetre Hospital APHP, Le Kremlin Bicetre, France
| | - Safwane El Hatimi
- Cardiology department, Bicetre Hospital APHP, Le Kremlin Bicetre, France
| | - Marie-France Bellin
- Radiology department, Bicetre Hospital APHP, 78 Rue du Général Leclerc, Le Kremlin Bicetre 94270, France
- Faculty of medicine, Paris-Saclay University, Le Kremlin Bicetre, France
- BioMaps Multimodal biomedical imaging laboratory, Paris-Saclay University, Le Kremlin Bicetre, France
| | - Olivier Meyrignac
- Radiology department, Bicetre Hospital APHP, 78 Rue du Général Leclerc, Le Kremlin Bicetre 94270, France
- Faculty of medicine, Paris-Saclay University, Le Kremlin Bicetre, France
- BioMaps Multimodal biomedical imaging laboratory, Paris-Saclay University, Le Kremlin Bicetre, France
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Kocaoglu M, Pednekar A, Tkach JA, Taylor MD. Quantitative assessment of velocity and flow using compressed SENSE in children and young adults with adequate acquired temporal resolution. J Cardiovasc Magn Reson 2021; 23:113. [PMID: 34663351 PMCID: PMC8522244 DOI: 10.1186/s12968-021-00811-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 09/03/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Phase contrast (PC) cardiovascular magnetic resonance (CMR) imaging with parallel imaging acceleration is established and validated for measuring velocity and flow. However, additional acceleration to further shorten acquisition times would be beneficial in patients with complex vasculature who need multiple PC-CMR measurements, especially pediatric patients with higher heart rates. METHODS PC-CMR images acquired with compressed sensitivity encoding (C-SENSE) factors of 3 to 6 and standard of care PC-CMR with sensitivity encoding (SENSE) factor of 2 (S2) acquired as part of clinical CMR examinations performed between November 2020 and January 2021 were analyzed retrospectively. The velocity and flow through the ascending aorta (AAo), descending aorta (DAo), and superior vena cava (SVC) in a transverse plane at the level of pulmonary artery bifurcation were compared. Additionally, frequency power distribution and dynamic time warp distance were calculated for these acquisitions. To further validate the adequate temporal resolution requirement, patients with S2 PC-CMR in the same acquisition plane were added in frequency power distribution analysis. RESULTS Twenty-eight patients (25 males; 15.9 ± 1.9 years; body surface area (BSA) 1.7 ± 0.2 m2; heart rate 81 ± 16 bpm) underwent all five PC-CMR acquisitions during the study period. An additional 22 patients (16 males; 17.5 ± 7.7 years; BSA 1.6 ± 0.5 m2; heart rate 91 ± 16 bpm) were included for frequency power spectrum analysis. As expected, scan time decreased with increasing C-SENSE acceleration factor = 3 (37.5 ± 6.5 s, 26.4 ± 7.6%), 4 (28.1 ± 4.9 s, 44.7 ± 5.6%), 5 (21.6 ± 3.6 s, 57.6 ± 4.4%), and 6 (19.1 ± 3.2 s, 62.3 ± 4.2%) relative to SENSE = 2 (51.3 ± 10.1 s) PC-CMR acquisition. Mean peak velocity, net flow, and cardiac output were comparable (p > 0.87) between the five PC-CMR acquisitions with mean differences less than < 4%, < 2%, and < 3% respectively. All individual blood vessels showed a non-significant dependence of difference in fmax99 (< 4 Hz, p > 0.2), and dynamic time warp distance (p > 0.3) on the C-SENSE acceleration factor used. There was a strongly correlated (r = 0.74) increase in fmax99 (10.5 ± 2.2, range: 7.1-16.4 Hz) with increasing heart rate. The computed minimum required cardiac phase number was 15 ± 2.0 (range: 11-20) over the heart rate of 86 ± 15 bpm (range: 58-113 bpm). CONCLUSIONS Stroke volume, cardiac output, and mean peak velocity measurements using PC-CMR with C-SENSE of up to 6 agree with measurements by standard of care PC-CMR with SENSE = 2 and resulted in up to a 65% reduction in acquisition time. Adequate temporal sampling can be ensured by acquiring 20 cardiac phases throughout the entire cardiac cycle over a wide range of pediatric and young adult heart rates.
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Affiliation(s)
- Murat Kocaoglu
- Department of Radiology, Cincinnati Children’s Hospital Medical Center, S1.533, 3333 Burnet Ave, Cincinnati, OH 45229 USA
- Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - Amol Pednekar
- Department of Radiology, Cincinnati Children’s Hospital Medical Center, S1.533, 3333 Burnet Ave, Cincinnati, OH 45229 USA
- Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - Jean A. Tkach
- Department of Radiology, Cincinnati Children’s Hospital Medical Center, S1.533, 3333 Burnet Ave, Cincinnati, OH 45229 USA
- Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - Michael D. Taylor
- The Heart Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH USA
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Han D, Yuan R, Jiang X, Geng S, Zhong Q, Zhang Y, Yao Z, Wang F. Nanosecond resolution photography system for laser-induced cavitation based on PIV dual-head laser and industrial camera. Ultrason Sonochem 2021; 78:105733. [PMID: 34536700 PMCID: PMC8452887 DOI: 10.1016/j.ultsonch.2021.105733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 08/09/2021] [Accepted: 08/19/2021] [Indexed: 06/13/2023]
Abstract
The detailed study of the initial and collapse processes of the laser-induced cavitation requires nanosecond resolution (both nanoseconds exposure and nanoseconds interframe time) of the photography measurement system. The high-speed video cameras are difficult to achieve nanoseconds interval time. The framing and streak cameras are able to reach the nanosecond resolution, but their complex technology and expensive prices make them far from being commercially available. The present study builds a nanosecond resolution photography system based on PIV dual-head laser and conventional industrial camera. The exposure time of the photography system is controlled by the laser pulse width, which is 5 ns. The two heads of the PIV laser are operated independently thus the smallest time interval between two laser pulses can be set to less than 10 ns. A double-pulse per-exposure imaging technique is used to record the information from two laser pulses on single frame on a low-speed industrial camera. The nanosecond resolution photography system was applied to the laser-induced cavitation experiments to verify the reliability of the measurement results. The measurement of the shock wave velocity demonstrates the ability of the system to capture ultrafast phenomena, which reduces from 3611 m/s to approximately 1483 m/s within 400 ns. The experimental results also reveal the asymmetric evolution of laser-induced cavitation bubbles. The major axis of the ellipsoidal bubble has twice reversals along the laser propagation and perpendicular direction from the laser-induced breakdown to the first collapse.
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Affiliation(s)
- Dixi Han
- College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China
| | - Rui Yuan
- College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China
| | - Xinkuan Jiang
- College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China
| | - Siyuan Geng
- College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China
| | - Qiang Zhong
- College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China; Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing 100083, China.
| | - Yifan Zhang
- College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China
| | - Zhifeng Yao
- College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China; Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing 100083, China
| | - Fujun Wang
- College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China; Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing 100083, China
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Tavakoli P, Duda V, Boafo A, Campbell K. The effects of sleep on objective measures of gap detection using a time-efficient multi-deviant paradigm. Brain Cogn 2021; 152:105772. [PMID: 34218026 DOI: 10.1016/j.bandc.2021.105772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 04/14/2021] [Accepted: 06/23/2021] [Indexed: 10/21/2022]
Abstract
Auditory temporal resolution, measured through gap detection, is critical for the perception of speech. A time-efficient multi-deviant paradigm has previously been developed for gap detection. The purpose of the present study was to determine if this multi-deviant paradigm could be used for gap detection during NREM sleep. ERPs were recorded in 10 young adults while awake and during the first two hours of NREM sleep. A multi-deviant paradigm was employed with six different deviants varying in gap duration, ranging from 2 to 40 ms. During waking, a DRN was observed for the 10, 20, 30 and 40 ms gaps. The DRN was absent during sleep. A P2 was present in NREM for the 20, 30 and 40 ms gaps followed by a P3a to the 30 and 40 ms gaps. An N350 was observed following the 10, 20, 30 and 40 ms gaps. Previous studies have reported significant ERPs to gaps having shorter durations than the present study. The multi-deviant paradigm may not be suitable for the determination of gap threshold during sleep. Nevertheless, it provides an exquisite means to determine perceptibility and the extent of processing of longer duration, supra-threshold gaps during sleep.
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Risk BB, Murden RJ, Wu J, Nebel MB, Venkataraman A, Zhang Z, Qiu D. Which multiband factor should you choose for your resting-state fMRI study? Neuroimage 2021; 234:117965. [PMID: 33744454 PMCID: PMC8159874 DOI: 10.1016/j.neuroimage.2021.117965] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/05/2021] [Accepted: 03/06/2021] [Indexed: 12/30/2022] Open
Abstract
Multiband acquisition, also called simultaneous multislice, has become a popular technique in resting-state functional connectivity studies. Multiband (MB) acceleration leads to a higher temporal resolution but also leads to spatially heterogeneous noise amplification, suggesting the costs may be greater in areas such as the subcortex. We evaluate MB factors of 2, 3, 4, 6, 8, 9, and 12 with 2 mm isotropic voxels, and additionally 2 mm and 3.3 mm single-band acquisitions, on a 32-channel head coil. Noise amplification was greater in deeper brain regions, including subcortical regions. Correlations were attenuated by noise amplification, which resulted in spatially varying biases that were more severe at higher MB factors. Temporal filtering decreased spatial biases in correlations due to noise amplification, but also tended to decrease effect sizes. In seed-based correlation maps, left-right putamen connectivity and thalamo-motor connectivity were highest in the single-band 3.3 mm protocol. In correlation matrices, MB 4, 6, and 8 had a greater number of significant correlations than the other acquisitions (both with and without temporal filtering). We recommend single-band 3.3 mm for seed-based subcortical analyses, and MB 4 provides a reasonable balance for studies analyzing both seed-based correlation maps and connectivity matrices. In multiband studies including secondary analyses of large-scale datasets, we recommend reporting effect sizes or test statistics instead of correlations. If correlations are reported, temporal filtering (or another method for thermal noise removal) should be used. The Emory Multiband Dataset is available on OpenNeuro.
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Affiliation(s)
- Benjamin B Risk
- Department of Biostatistics and Bioinformatics, Atlanta, GA, United States.
| | - Raphiel J Murden
- Department of Biostatistics and Bioinformatics, Atlanta, GA, United States
| | - Junjie Wu
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, United States
| | - Mary Beth Nebel
- Center for Neurodevelopmental and Imaging Research, Kennedy Krieger Institute, Baltimore, MD, United States; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Arun Venkataraman
- Department of Physics and Astronomy, University of Rochester, Rochester, NY, United States
| | - Zhengwu Zhang
- Department of Statistics and Operations Research, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Deqiang Qiu
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, United States
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Backhaus SJ, Metschies G, Billing M, Schmidt-Rimpler J, Kowallick JT, Gertz RJ, Lapinskas T, Pieske-Kraigher E, Pieske B, Lotz J, Bigalke B, Kutty S, Hasenfuß G, Kelle S, Schuster A. Defining the optimal temporal and spatial resolution for cardiovascular magnetic resonance imaging feature tracking. J Cardiovasc Magn Reson 2021; 23:60. [PMID: 34001175 PMCID: PMC8127257 DOI: 10.1186/s12968-021-00740-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Accepted: 03/16/2021] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Myocardial deformation analyses using cardiovascular magnetic resonance (CMR) feature tracking (CMR-FT) have incremental value in the assessment of cardiac function beyond volumetric analyses. Since guidelines do not recommend specific imaging parameters, we aimed to define optimal spatial and temporal resolutions for CMR cine images to enable reliable post-processing. METHODS Intra- and inter-observer reproducibility was assessed in 12 healthy subjects and 9 heart failure (HF) patients. Cine images were acquired with different temporal (20, 30, 40 and 50 frames/cardiac cycle) and spatial resolutions (high in-plane 1.5 × 1.5 mm through-plane 5 mm, standard 1.8 × 1.8 x 8mm and low 3.0 × 3.0 x 10mm). CMR-FT comprised left ventricular (LV) global and segmental longitudinal/circumferential strain (GLS/GCS) and associated systolic strain rates (SR), and right ventricular (RV) GLS. RESULTS Temporal but not spatial resolution did impact absolute strain and SR. Maximum absolute changes between lowest and highest temporal resolution were as follows: 1.8% and 0.3%/s for LV GLS and SR, 2.5% and 0.6%/s for GCS and SR as well as 1.4% for RV GLS. Changes of strain values occurred comparing 20 and 30 frames/cardiac cycle including LV and RV GLS and GCS (p < 0.001-0.046). In contrast, SR values (LV GLS/GCS SR) changed significantly comparing all successive temporal resolutions (p < 0.001-0.013). LV strain and SR reproducibility was not affected by either temporal or spatial resolution, whilst RV strain variability decreased with augmentation of temporal resolution. CONCLUSION Temporal but not spatial resolution significantly affects strain and SR in CMR-FT deformation analyses. Strain analyses require lower temporal resolution and 30 frames/cardiac cycle offer consistent strain assessments, whilst SR measurements gain from further increases in temporal resolution.
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Affiliation(s)
- Sören J. Backhaus
- Department of Cardiology and Pneumology, University Medical Center Göttingen, Georg-August University, Robert-Koch-Str. 40, 37099 Göttingen, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
| | - Georg Metschies
- Department of Cardiology and Pneumology, University Medical Center Göttingen, Georg-August University, Robert-Koch-Str. 40, 37099 Göttingen, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
| | - Marcus Billing
- Department of Cardiology and Pneumology, University Medical Center Göttingen, Georg-August University, Robert-Koch-Str. 40, 37099 Göttingen, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
| | - Jonas Schmidt-Rimpler
- Department of Cardiology and Pneumology, University Medical Center Göttingen, Georg-August University, Robert-Koch-Str. 40, 37099 Göttingen, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
| | - Johannes T. Kowallick
- German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
- Institute for Diagnostic and Interventional Radiology, University Medical Center Göttingen, Georg-August University, Göttingen, Germany
| | - Roman J. Gertz
- Department of Cardiology and Pneumology, University Medical Center Göttingen, Georg-August University, Robert-Koch-Str. 40, 37099 Göttingen, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
| | - Tomas Lapinskas
- German Heart Center Berlin (DHZB), Department of Internal Medicine/Cardiology, University of Berlin, Charité Campus Virchow Clinic, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site, Berlin, Germany
- Department of Cardiology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Elisabeth Pieske-Kraigher
- German Heart Center Berlin (DHZB), Department of Internal Medicine/Cardiology, University of Berlin, Charité Campus Virchow Clinic, Berlin, Germany
| | - Burkert Pieske
- German Heart Center Berlin (DHZB), Department of Internal Medicine/Cardiology, University of Berlin, Charité Campus Virchow Clinic, Berlin, Germany
| | - Joachim Lotz
- German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
- Institute for Diagnostic and Interventional Radiology, University Medical Center Göttingen, Georg-August University, Göttingen, Germany
| | - Boris Bigalke
- Department of Cardiology and Pneumology, Charité Campus Benjamin Franklin, University Medical Center Berlin, Berlin, Germany
| | - Shelby Kutty
- Taussig Heart Center, Johns Hopkins Hospital, Baltimore, MD 21287 USA
| | - Gerd Hasenfuß
- Department of Cardiology and Pneumology, University Medical Center Göttingen, Georg-August University, Robert-Koch-Str. 40, 37099 Göttingen, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
| | - Sebastian Kelle
- German Heart Center Berlin (DHZB), Department of Internal Medicine/Cardiology, University of Berlin, Charité Campus Virchow Clinic, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site, Berlin, Germany
| | - Andreas Schuster
- Department of Cardiology and Pneumology, University Medical Center Göttingen, Georg-August University, Robert-Koch-Str. 40, 37099 Göttingen, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
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Sudarshan VP, Li S, Jamadar SD, Egan GF, Awate SP, Chen Z. Incorporation of anatomical MRI knowledge for enhanced mapping of brain metabolism using functional PET. Neuroimage 2021; 233:117928. [PMID: 33716154 DOI: 10.1016/j.neuroimage.2021.117928] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 02/08/2021] [Accepted: 02/28/2021] [Indexed: 02/07/2023] Open
Abstract
Functional positron emission tomography (fPET) imaging using continuous infusion of [18F]-fluorodeoxyglucose (FDG) is a novel neuroimaging technique to track dynamic glucose utilization in the brain. In comparison to conventional static or dynamic bolus PET, fPET maintains a sustained supply of glucose in the blood plasma which improves sensitivity to measure dynamic glucose changes in the brain, and enables mapping of dynamic brain activity in task-based and resting-state fPET studies. However, there is a trade-off between temporal resolution and spatial noise due to the low concentration of FDG and the limited sensitivity of multi-ring PET scanners. Images from fPET studies suffer from partial volume errors and residual scatter noise that may cause the cerebral metabolic functional maps to be biased. Gaussian smoothing filters used to denoise the fPET images are suboptimal, as they introduce additional partial volume errors. In this work, a post-processing framework based on a magnetic resonance (MR) Bowsher-like prior was used to improve the spatial and temporal signal to noise characteristics of the fPET images. The performance of the MR guided method was compared with conventional denosing methods using both simulated and in vivo task fPET datasets. The results demonstrate that the MR-guided fPET framework denoises the fPET images and improves the partial volume correction, consequently enhancing the sensitivity to identify brain activation, and improving the anatomical accuracy for mapping changes of brain metabolism in response to a visual stimulation task. The framework extends the use of functional PET to investigate the dynamics of brain metabolic responses for faster presentation of brain activation tasks, and for applications in low dose PET imaging.
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Choi HG, Hong SK, Lee HJ, Chang J. Acute Alcohol Intake Deteriorates Hearing Thresholds and Speech Perception in Noise. Audiol Neurootol 2020; 26:218-225. [PMID: 33341812 DOI: 10.1159/000510694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 08/05/2020] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES The hearing process involves complex peripheral and central auditory pathways and could be influenced by various situations or medications. To date, there is very little known about the effects of alcohol on the auditory performances. The purpose of the present study was to evaluate how acute alcohol administration affects various aspects of hearing performance in human subjects, from the auditory perceptive threshold to the speech-in-noise task, which is cognitively demanding. METHODS A total of 43 healthy volunteers were recruited, and each of the participants received calculated amounts of alcohol according to their body weight and sex with a targeted blood alcohol content level of 0.05% using the Widmark formula. Hearing was tested in alcohol-free conditions (no alcohol intake within the previous 24 h) and acute alcohol conditions. A test battery composed of pure-tone audiometry, speech reception threshold (SRT), word recognition score (WRS), distortion product otoacoustic emission (DPOAE), gaps-in-noise (GIN) test, and Korean matrix sentence test (testing speech perception in noise) was performed in the 2 conditions. RESULTS Acute alcohol intake elevated pure-tone hearing thresholds and SRT but did not affect WRS. Both otoacoustic emissions recorded with DPOAE and the temporal resolution measured with the GIN test were not influenced by alcohol intake. The hearing performance in a noisy environment in both easy (-2 dB signal-to-noise ratio [SNR]) and difficult (-8 dB SNR) conditions was decreased by alcohol. CONCLUSIONS Acute alcohol elevated auditory perceptive thresholds and affected performance in complex and difficult auditory tasks rather than simple tasks.
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Affiliation(s)
- Hyo Geun Choi
- Department of Otorhinolaryngology-Head & Neck Surgery, Hallym University College of Medicine, Chuncheon, Republic of Korea.,Laboratory of Brain & Cognitive Sciences for Convergence Medicine, Hallym University College of Medicine, Anyang, Republic of Korea
| | - Sung Kwang Hong
- Department of Otorhinolaryngology-Head & Neck Surgery, Hallym University College of Medicine, Chuncheon, Republic of Korea.,Laboratory of Brain & Cognitive Sciences for Convergence Medicine, Hallym University College of Medicine, Anyang, Republic of Korea
| | - Hyo-Jeong Lee
- Department of Otorhinolaryngology-Head & Neck Surgery, Hallym University College of Medicine, Chuncheon, Republic of Korea, .,Laboratory of Brain & Cognitive Sciences for Convergence Medicine, Hallym University College of Medicine, Anyang, Republic of Korea,
| | - Jiwon Chang
- Department of Otorhinolaryngology-Head & Neck Surgery, Hallym University College of Medicine, Chuncheon, Republic of Korea
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Santini F, Pansini M, Hrabak-Paar M, Yates D, Langenickel TH, Bremerich J, Bieri O, Schubert T. On the optimal temporal resolution for phase contrast cardiovascular magnetic resonance imaging: establishment of baseline values. J Cardiovasc Magn Reson 2020; 22:72. [PMID: 33012283 PMCID: PMC7534161 DOI: 10.1186/s12968-020-00669-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 09/08/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The aim of this study is to quantify the frequency content of the blood velocity waveform in different body regions by means of phase contrast (PC) cardiovascular magnetic resonance (CMR) and Doppler ultrasound. The highest frequency component of the spectrum is inversely proportional to the ideal temporal resolution to be used for the acquisition of flow-sensitive imaging (Shannon-Nyquist theorem). METHODS Ten healthy subjects (median age 33y, range 24-40) were scanned with a high-temporal-resolution PC-CMR and with Doppler ultrasound on three body regions (carotid arteries, aorta and femoral arteries). Furthermore, 111 patients (median age 61y) with mild to moderate arterial hypertension and 58 patients with aortic aregurgitation, atrial septal defect, or repaired tetralogy of Fallot underwent aortic CMR scanning. The frequency power distribution was calculated for each location and the maximum frequency component, fmax, was extracted and expected limits for the general population were inferred. RESULTS In the healthy subject cohort, significantly different fmax values were found across the different body locations, but they were nonsignificant across modalities. No significant correlation was found with heart rate. The measured fmax ranged from 7.7 ± 1.1 Hz in the ascending aorta, up to 12.3 ± 5.1 Hz in the femoral artery (considering PC-CMR data). The calculated upper boundary for the general population ranged from 11.0 Hz to 27.5 Hz, corresponding to optimal temporal resolutions of 45 ms and 18 ms, respectively. The patient cohort exhibited similar values for the frequencies in the aorta, with no correlation between blood pressure and frequency content. CONCLUSIONS The temporal resolution of PC-CMR acquisitions can be adapted based on the scanned body region and in the adult population, should approach approximately 20 ms in the peripheral arteries and 40 ms in the aorta. TRIAL REGISTRATION This study presents results from a restrospective analysis of the clinical study NCT01870739 (ClinicalTrials.gov).
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Affiliation(s)
- Francesco Santini
- Department of Radiology, Division of Radiological Physics, University Hospital Basel, Petersgraben 4, 4031, Basel, Switzerland.
- Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland.
| | | | - Maja Hrabak-Paar
- University Hospital Center Zagreb, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Denise Yates
- Novartis Institutes of Biomedical Research, Cambridge, MA, USA
| | - Thomas H Langenickel
- Novartis Institutes for Biomedical Research, Translational Medicine, Basel, Switzerland
- Ethris GmbH, Planegg, Germany
| | - Jens Bremerich
- Department of Radiology, University Hospital Basel, Basel, Switzerland
| | - Oliver Bieri
- Department of Radiology, Division of Radiological Physics, University Hospital Basel, Petersgraben 4, 4031, Basel, Switzerland
- Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland
| | - Tilman Schubert
- Department of Neuroradiology, Zurich University Hospital, Zurich, Switzerland
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Eisen-Enosh A, Farah N, Burgansky-Eliash Z, Maharshak I, Polat U, Mandel Y. A dichoptic presentation device and a method for measuring binocular temporal function in the visual system. Exp Eye Res 2020; 201:108290. [PMID: 33022269 DOI: 10.1016/j.exer.2020.108290] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/16/2020] [Accepted: 09/03/2020] [Indexed: 10/23/2022]
Abstract
Recent studies highlight the importance of the temporal domain in visual processing. Critical Flicker Frequency (CFF), the frequency at which a flickering light is perceived as continuous, is a widely used measure for evaluating visual temporal processing. Another important issue to investigate is the cortical interactions arising between the flicker stimuli of both eyes. This paper presents a robust and reliable dichoptic tool for evaluating the CFF threshold in both eyes. This system is based on an analog output device used to independently drive two LEDs through a custom-written MATLAB code (using a laptop PC) for eliciting sinusoidal flickering stimuli and for psychophysically measuring the perceived CFF threshold. The luminance and phases of each LED are individually controlled, enabling the investigation of the effect of phase and luminance differences on binocular summation in subjects with different ocular pathologies. Experiments were designed to evaluate the CFF threshold through a psychophysical test, based on a discrimination task with a stimulus duration of 1 s, based on a temporal alternative forced-choice paradigm. The target stimulus temporal features were modulated using the staircase method. Subjects were requested to discriminate between a target stimulus (a flickering light at various frequencies) and a flickering light at a frequency of 120 Hz, which is significantly higher than the CFF in humans; therefore, it is perceived as constant. One of the main advantages of the introduced dichoptic presentation system is that it enables the visual temporal performance to be measured under both monocular and binocular conditions where phenomena such as temporal binocular summation (BS) can be evaluated. Moreover, the system offers great flexibility by introducing a stimulus phase shift, which enables studying how stimulus timing affects the temporal function at millisecond scale resolution. Our results confirm that no crosstalk exists between the eyes and that the system can reliably separate the stimuli presented to the eyes. Using this set-up, we observed the binocular summation of CFF for low target luminance levels. The CFF was significantly (p = 0.011) higher (5.2%) under binocular compared with monocular viewing conditions. More importantly, introducing an inter - ocular phase shift reduced the binocular CFF in normally sighted subjects. Finally, in amblyopic subjects the amblyopic eye showed a decrease of 3.9 Hz (15%) in CFF, compared with the fellow eye (p = 0.001). The ability to assess binocular temporal performance using a dichoptic display can shed light on visual temporal performance in general, and on binocular temporal summation processes in particular, both for subjects with normal binocular vision and for subjects with impaired binocular vision (e.g., amblyopic subjects). Furthermore, such a presentation set-up may facilitate the development of training paradigms aimed at improving binocular vision performance. In this paper we describe the system and methods in detail and provide all necessary computer code and other details that will enable an easy and quick adaptation of the method by scientists interested in studying the temporal resolution of the visual system in general, and in studying inter-ocular differences or interactions in particular.
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Affiliation(s)
- Auria Eisen-Enosh
- School of Optometry and Vision Science, Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Nairouz Farah
- School of Optometry and Vision Science, Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Zvia Burgansky-Eliash
- E. Wolfson Medical Center, Holon, Israel; Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Idit Maharshak
- E. Wolfson Medical Center, Holon, Israel; Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Uri Polat
- School of Optometry and Vision Science, Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Yossi Mandel
- School of Optometry and Vision Science, Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel; Bar Ilan's Institute for Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat Gan, Israel; The Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel.
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Malekian V, Rastegar F, Shafieizargar B, Nasiraei-Moghaddam A. SSFP fMRI at 3 tesla: Efficiency of polar acquisition-reconstruction technique. Magn Reson Imaging 2020; 74:171-180. [PMID: 32898650 DOI: 10.1016/j.mri.2020.09.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 08/20/2020] [Accepted: 09/02/2020] [Indexed: 12/31/2022]
Abstract
SSFP-based fMRI techniques, known for their high specificity and low geometrical distortion, look promising for high-resolution brain mapping. Nevertheless, they suffer from lack of speed and sensitivity, leading them to be exploited mostly in high-field scanners. Radial acquisition can help with these inefficiencies through better tSNR and more effective coverage of the spatial frequencies. Here, we present a SSFP-fMRI approach and experimentally investigate it at 3 T scanners using radial readout for acquisition. In particular, the visual activity is mapped through three bSSFP techniques: 1- Cartesian, 2- Radial with re-gridding reconstruction, 3- Radial with Polar Fourier Transform (PFT) reconstruction. In the PFT technique streaking artifacts, generated at high acceleration rates by re-gridding reconstruction, are avoided and pixel size in the final framework is retrospectively selectable. General agreement, but better tSNR of Radial reading, was first confirmed for these techniques in detection of neural activities at 2 × 2 mm2 in-plane resolution for all 28 subjects,. Next the outcome of the PFT algorithm with 1 × 1 mm2 pixel size was compared to images reconstructed by re-gridding (from the same raw data) with the identical pixel size through interpolation. The localization of the activity showed improvement in PFT over interpolation both qualitatively (i.e., well-fitting in gray-matter) and quantitatively (i.e., higher z-scores and tSNR). The proposed technique can therefore be considered as a remedy for lack of speed and sensitivity in SSFP-based fMRI, in conventional field strengths. The proposed approach is particularly useful in task-based studies when we concentrate on a ROI considerably smaller than FOV, without sacrificing spatial resolution.
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Affiliation(s)
- Vahid Malekian
- School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran; Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Iran
| | - Fatemeh Rastegar
- Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Iran; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Banafshe Shafieizargar
- Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Iran; imec-Vision Lab, Department of Physics, University of Antwerp, Belgium
| | - Abbas Nasiraei-Moghaddam
- School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran; Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Iran.
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Li W, Fang H, Qin G, Tan X, Huang Z, Zeng F, Du H, Li S. Concentration estimation of dissolved oxygen in Pearl River Basin using input variable selection and machine learning techniques. Sci Total Environ 2020; 731:139099. [PMID: 32434098 DOI: 10.1016/j.scitotenv.2020.139099] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/27/2020] [Accepted: 04/27/2020] [Indexed: 06/11/2023]
Abstract
Dissolved oxygen (DO) concentration is an essential index for water environment assessment. Here, we present a modeling approach to estimate DO concentrations using input variable selection and data-driven models. Specifically, the input variable selection technique, the maximal information coefficient (MIC), was used to identify and screen the primary environmental factors driving variation in DO. The data-driven model, support vector regression (SVR), was then used to construct a robust model to estimate DO concentration. The approach was illustrated through a case study of the Pearl River Basin in China. We show that the MIC technique can effectively screen major local environmental factors affecting DO concentrations. MIC value tended to stabilize when the sample size >3000 and EC had the highest score with an MIC >0.3 at both of the stations. The variable-reduced datasets improved the performance of the SVR model by a reduction of 28.65% in RMSE, and increase of 22.16%, 56.27% in R2, NSE, respectively, relative to complete candidate sets. The MIC-SVR model constructed at the tidal river network performed better than nontidal river network by a reduction of approximately 63.01% in RMSE, an increase of 62.36% in NSE, and R2 >0.9. Overall, the proposed technique was able to handle nonlinearity among environmental factors and accurately estimate DO concentrations in tidal river network regions.
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Affiliation(s)
- Wenjing Li
- National Key Laboratory of Water Environmental Simulation and Pollution Control, Guangdong Key Laboratory of Water and Air Pollution Control, South China Institute of Environmental Sciences, Ministry of Environmental Protection of the People's Republic of China, Guangzhou 510530, China
| | - Huaiyang Fang
- National Key Laboratory of Water Environmental Simulation and Pollution Control, Guangdong Key Laboratory of Water and Air Pollution Control, South China Institute of Environmental Sciences, Ministry of Environmental Protection of the People's Republic of China, Guangzhou 510530, China
| | - Guangxiong Qin
- National Key Laboratory of Water Environmental Simulation and Pollution Control, Guangdong Key Laboratory of Water and Air Pollution Control, South China Institute of Environmental Sciences, Ministry of Environmental Protection of the People's Republic of China, Guangzhou 510530, China
| | - Xiuqin Tan
- National Key Laboratory of Water Environmental Simulation and Pollution Control, Guangdong Key Laboratory of Water and Air Pollution Control, South China Institute of Environmental Sciences, Ministry of Environmental Protection of the People's Republic of China, Guangzhou 510530, China
| | - Zhiwei Huang
- National Key Laboratory of Water Environmental Simulation and Pollution Control, Guangdong Key Laboratory of Water and Air Pollution Control, South China Institute of Environmental Sciences, Ministry of Environmental Protection of the People's Republic of China, Guangzhou 510530, China
| | - Fantang Zeng
- National Key Laboratory of Water Environmental Simulation and Pollution Control, Guangdong Key Laboratory of Water and Air Pollution Control, South China Institute of Environmental Sciences, Ministry of Environmental Protection of the People's Republic of China, Guangzhou 510530, China
| | - Hongwei Du
- National Key Laboratory of Water Environmental Simulation and Pollution Control, Guangdong Key Laboratory of Water and Air Pollution Control, South China Institute of Environmental Sciences, Ministry of Environmental Protection of the People's Republic of China, Guangzhou 510530, China.
| | - Shuping Li
- School of Geography and Planning, Sun Yat-sen University, Guangzhou 510275, China.
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Li Z, Ho KF, Yim SHL. Source apportionment of hourly-resolved ambient volatile organic compounds: Influence of temporal resolution. Sci Total Environ 2020; 725:138243. [PMID: 32298889 DOI: 10.1016/j.scitotenv.2020.138243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/20/2020] [Accepted: 03/25/2020] [Indexed: 06/11/2023]
Abstract
High temporal-resolution VOC concentration data can provide detailed and important temporal variations of VOC species and emission sources, which is not possible when using coarse temporal-resolution data. In this study, we utilized the positive matrix factorization (PMF) model to conduct source apportionment of hourly concentrations of nineteen VOC species and CO measured at the Mong Kok air quality monitoring station, operated by the Hong Kong Environmental Protection Department, from January 2013 to December 2014. The PMF analysis of the hourly dataset (PMF_Hourly) identified five sources, including liquefied petroleum gas (LPG) (contribution of 45%), gasoline exhaust (21%), combustion (20%), biogenic emission (9%), and paint solvents (6%). The diurnal patterns of VOC emissions from identified sources are likely to be affected by the strength of emissions, variation of the planetary boundary layer height, and photochemical reactions. In addition, the PMF analyses of hourly and 24-hour averaged data of the hourly-resolved data (PMF_Hourly and PMF_Daily) were generally comparable, but the time series of VOC emissions from PMF_Hourly could not be well captured by PMF_Daily for two local VOC sources of gasoline exhaust and LPG. This study highlights the benefit of high temporal-resolution measurement data in apportioning VOC sources, hence providing critical information on VOC emission sources (e.g., diurnal variations) for controlling VOC emissions effectively.
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Affiliation(s)
- Zhiyuan Li
- Institute of Environment, Energy and Sustainability, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
| | - Kin-Fai Ho
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; Institute of Environment, Energy and Sustainability, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
| | - Steve Hung Lam Yim
- Department of Geography and Resource Management, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; Institute of Environment, Energy and Sustainability, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; Stanley Ho Big Data Decision Analytics Research Centre, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
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Choi YJ, Ahlman MA, Mallek M, Cork TE, Chen MY, Bluemke DA, Sandfort V. Cardiac cine CT approaching 1 mSv: implementation and assessment of a 58-ms temporal resolution protocol. Int J Cardiovasc Imaging 2020; 36:1583-1591. [PMID: 32367189 DOI: 10.1007/s10554-020-01863-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 04/22/2020] [Indexed: 11/25/2022]
Abstract
Clinical use of cardiac cine CT imaging is limited by high radiation dose and low temporal resolution. To evaluate a low radiation dose, high temporal resolution cardiac cine CT protocol in human cardiac CT and phantom scans. CT scans of a circulating iodine target were reconstructed using the conventional single heartbeat half-scan (HS, approx. 175 ms temporal resolution) and the 3-heartbeat multi-segment (MS, approx. 58 ms) algorithms. Motion artifacts were quantified by the root-mean-square error (RMSE). Low-dose cardiac cine CT scans were performed in 55 subjects at a tube potential of 80 kVp and current of 80 mA. Image quality of HS and MS scans was assessed by blinded reader quality assessment, left ventricular (LV) free wall motion, and LV ejection rate. Motion artifacts in phantom scans were higher in HS than in MS reconstructions (RSME 188 and 117 HU, respectively; p = 0.001). Median radiation dose in human scans was 1.2 mSv. LV late diastolic filling was observed more frequently in MS than in HS images (42 vs. 26 subjects, respectively; p < 0.001). LV free wall systolic motion was more physiologic and had less error in MS than in HS reconstructions (sum-of-squared errors 34 vs. 45 mm2, respectively; p < 0.001), and LV peak ejection rate was higher in MS than in HS reconstructions (166 vs. 152 mL/s, respectively; p < 0.001). Cardiac cine CT imaging is feasible at a low radiation dose of 1.2 mSv. MS reconstruction showed improved imaging of rapid motion in phantom studies and human cardiac CTs.
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Affiliation(s)
- Younhee J Choi
- Department of Radiology and Imaging Sciences, National Institutes of Health, 10 Center Drive, Bethesda, MD, 20892, USA
| | - Mark A Ahlman
- Department of Radiology and Imaging Sciences, National Institutes of Health, 10 Center Drive, Bethesda, MD, 20892, USA
| | - Marissa Mallek
- Department of Radiology and Imaging Sciences, National Institutes of Health, 10 Center Drive, Bethesda, MD, 20892, USA
| | - Tyler E Cork
- Department of Radiology and Imaging Sciences, National Institutes of Health, 10 Center Drive, Bethesda, MD, 20892, USA
| | - Marcus Y Chen
- Advanced Cardiovascular Imaging Laboratory, National Heart, Lung, and Blood Institute, 10 Center Drive, Bethesda, MD, 20892, USA
| | - David A Bluemke
- Department of Radiology and Imaging Sciences, National Institutes of Health, 10 Center Drive, Bethesda, MD, 20892, USA
- Department of Radiology, University of Wisconsin, 600 Highland Ave, Madison, WI, USA
| | - Veit Sandfort
- Department of Radiology and Imaging Sciences, National Institutes of Health, 10 Center Drive, Bethesda, MD, 20892, USA.
- Department of Radiology, Stanford Medicine, 300 Pasteur Drive, Stanford, CA, USA.
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Tuz D, Aslan F, Böke B, Yücel E. Assessment of temporal processing functions in early period cochlear implantation. Eur Arch Otorhinolaryngol 2020; 277:1939-1947. [PMID: 32221678 DOI: 10.1007/s00405-020-05935-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 03/18/2020] [Indexed: 11/30/2022]
Abstract
PURPOSE The purpose of this study is to compare the temporal processing performance of children with cochlear implant (CI) according to the age of implantation and to determine their relation with auditory perception scores. METHODS In this study, 30 cochlear implant users and ten normal hearing children at 9 and 10 years were included. Children with cochlear implants are divided into two groups according to the age of implantation: group I includes participants whose implantation age is between 13 and 35 months (20 children), group II includes participants whose implantation age is between 36 and 45 months (10 children). Individuals were evaluated with random gap detection test (RGDT), duration pattern test (DPT), frequency pattern test (FPT), the Mr. Potato Head task, word recognition, and sentence recognition test. RESULTS A significant difference was found between the control and CI groups in temporal processing performance. The temporal processing ability of CI groups was significantly worse than those of normal hearing. Although there was no significant difference among the groups with cochlear implant in terms of temporal processing performance, children who started to use CI at an earlier age showed a tendency of better performance on temporal processing tasks. There was a significant relationship between Daily Sentence Test and FPT, and the Mr. Potato Head task and FPT rev (the score calculated by accepting the reverse patterns correctly). There was a significant relationship between duration of implant use and temporal ordering performance CONCLUSION: In this study, children with CI cannot perform as well as normal-hearing peers on temporal processing tasks, even if they had started to use their CIs at an early age. It is important to evaluate temporal processing in implanted individuals and to guide auditory training considering the evaluation results.
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Affiliation(s)
- Deniz Tuz
- Department of Audiology, Faculty of Health Sciences, Hacettepe University, 06100, Ankara, Turkey.
| | - Filiz Aslan
- Department of Audiology, Faculty of Health Sciences, Hacettepe University, 06100, Ankara, Turkey
| | - Bilgehan Böke
- ENT Department, Medical Faculty, Hacettepe University, 06100, Ankara, Turkey
| | - Esra Yücel
- Department of Audiology, Faculty of Health Sciences, Hacettepe University, 06100, Ankara, Turkey
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Abstract
Birds, and especially raptors, are highly visual animals. Some of them have the highest spatial resolving power known in the animal kingdom, allowing prey detection at distance. While many raptors visually track fast-moving and manoeuvrable prey, requiring high temporal resolution, this aspect of their visual system has never been studied before. In this study, we estimated how fast raptors can see, by measuring the flicker fusion frequency of three species with different lifestyles. We found that flicker fusion frequency differed among species, being at least 129 Hz in the peregrine falcon, Falco peregrinus, 102 Hz in the saker falcon, Falco cherrug, and 81 Hz in the Harris's hawk, Parabuteo unicinctus We suggest a potential link between fast vision and hunting strategy, with high temporal resolution in the fast-flying falcons that chase fast-moving, manoeuvrable prey and a lower resolution in the Harris's hawk, which flies more slowly and targets slower prey.
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Affiliation(s)
- Simon Potier
- Lund Vision Group, Department of Biology, Lund University, Sölvegatan 35, Lund S-22362, Sweden
| | - Margaux Lieuvin
- Lund Vision Group, Department of Biology, Lund University, Sölvegatan 35, Lund S-22362, Sweden
| | - Michael Pfaff
- Lund Vision Group, Department of Biology, Lund University, Sölvegatan 35, Lund S-22362, Sweden
| | - Almut Kelber
- Lund Vision Group, Department of Biology, Lund University, Sölvegatan 35, Lund S-22362, Sweden
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Chen Q, Li Y, Jiang R, Zou C, Tie C, Wen J, Yang X, Zhang X, Liu X, Zheng H. A flexible 9-channel coil array for fast 3D MR thermometry in MR-guided high-intensity focused ultrasound (HIFU) studies on rabbits at 3 T. Magn Reson Imaging 2019; 65:37-44. [PMID: 31655140 DOI: 10.1016/j.mri.2019.10.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 09/12/2019] [Accepted: 10/14/2019] [Indexed: 01/09/2023]
Abstract
Signal-to-noise ratio (SNR) is a critical factor in MR-guided high-intensity focused ultrasound (HIFU) for local heating, which can affect the accuracy of temperature measurement. In order to achieve high SNR and higher temporal resolution, dedicated coil arrays for MR-guided HIFU applications need to be developed. In this work, a flexible 9-channel coil array was designed, and constructed at 3 T to achieve fast temperature mapping for MR-guided HIFU applications on rabbit leg muscle. Coil performance was evaluated for SNR, and parallel imaging capability by in-vivo studies. Compared to a commercially available 4-channel flexible coil array, the dedicated 9-channel coil array has a much higher SNR, with at least a 2.6-fold increment in the region of interest (ROI). The inverse g-factors maps demonstrated that the dedicated 9-channel coil array has a better parallel imaging capability than the Flex Small 4. With accelerations normal to the array direction, both coil arrays showed much higher g-factors than those of accelerations along the array direction. Room temperature mapping was implemented to evaluate the temperature measurement accuracy by in-vivo experiments. The precisions of the 9-channel coil, ±0.18 °C for un-acceleration and ± 0.56 °C for acceleration at R = 2 × 2, both improved by an order of magnitude than these of the 4-channel coil, which were ± 1.45 °C for un-acceleration and ± 3.52 °C for acceleration at R = 2 × 2. In the fast temperature imaging on the rabbit leg muscle with heating, a high temporal resolution of 3.3 s with a temperature measurement precision of ±0.56 °C has been achieved using the dedicated 9-channel coil. This study demonstrates that the dedicated 9-channel coil array for rabbit leg imaging provides improved performance in SNR, parallel imaging capability, and the accuracy of temperature measurement compared to a commercial 4-channel coil, and it also achieves fast temperature mapping in practical MR-guided HIFU applications.
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Affiliation(s)
- Qiaoyan Chen
- Lauterbur Imaging Research Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China; Shenzhen Key Laboratory for MRI, Shenzhen, China
| | - Ye Li
- Lauterbur Imaging Research Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China; Shenzhen Key Laboratory for MRI, Shenzhen, China
| | - Rui Jiang
- Lauterbur Imaging Research Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China; Shenzhen Key Laboratory for MRI, Shenzhen, China
| | - Chao Zou
- Lauterbur Imaging Research Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China; Shenzhen Key Laboratory for MRI, Shenzhen, China
| | - Changjun Tie
- Lauterbur Imaging Research Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China; Shenzhen Key Laboratory for MRI, Shenzhen, China
| | - Jianhong Wen
- Lauterbur Imaging Research Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China; Shenzhen Key Laboratory for MRI, Shenzhen, China
| | - Xing Yang
- Lauterbur Imaging Research Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China; Shenzhen Key Laboratory for MRI, Shenzhen, China
| | - Xiaoliang Zhang
- Department of Radiology and Biomedical Imaging, University of California San Francisco, CA, United States; UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA, United States
| | - Xin Liu
- Lauterbur Imaging Research Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China; Shenzhen Key Laboratory for MRI, Shenzhen, China
| | - Hairong Zheng
- Lauterbur Imaging Research Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China; Shenzhen Key Laboratory for MRI, Shenzhen, China.
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Zhang L, Dong Q. Analytical analysis and simulation on fringe field effect of deflector plates applied in ultrafast electron microscopy. Micron 2019; 126:102751. [PMID: 31525718 DOI: 10.1016/j.micron.2019.102751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/07/2019] [Accepted: 09/07/2019] [Indexed: 11/26/2022]
Abstract
Deflector plates are one of the critical components in ultrafast electron microscope (UEM), which generates the short electron pulse. While the electron pulse can be stretched due to the velocity dispersion induced by the fringe field of the deflector plates, understanding the effect of the fringe field on the electron velocity and how to avoid the adverse effect of it are needed in the design of the deflector plates. In this paper, firstly, an analytical model of the fringe field of deflector plates with double field input is given. This analytical model can be adapted to other new designs with different double field inputs, and as an example, the velocity dispersion, stretched time, and energy gain of an electron pulse are calculated with a linear double field input. Secondly, three sets of particle tracing simulations on electron velocities have been studied in terms of different single field inputs. The simulated results show that the longitudinal velocity of the electron changes very differently as a result of the different voltage sign on the deflector plates. In our model, the longitudinal velocity is almost constant until the electron leaves the deflector plates. So the results suggest that the deflector plates with double field input are recommended not only in UEM setups but also in other charged particle beam setups where needs high deflection accuracy.
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Affiliation(s)
- Lixin Zhang
- School of Instrumentation and Optoelectronic Engineering, Beihang University, Beijing, 100191, China; Key Laboratory of Micro-nano Measurement-Manipulation and Physics (Ministry of Education), Beihang University, Beijing, 100191, China.
| | - Quanlin Dong
- School of Instrumentation and Optoelectronic Engineering, Beihang University, Beijing, 100191, China; Key Laboratory of Micro-nano Measurement-Manipulation and Physics (Ministry of Education), Beihang University, Beijing, 100191, China
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Qu M, Anderson S, Lyu P, Malang Y, Lai J, Liu J, Jiang B, Xie F, Liu HHT, Lefebvre DD, Wang YS. Effective aerial monitoring of cyanobacterial harmful algal blooms is dependent on understanding cellular migration. Harmful Algae 2019; 87:101620. [PMID: 31349882 DOI: 10.1016/j.hal.2019.101620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 03/22/2019] [Accepted: 05/24/2019] [Indexed: 06/10/2023]
Abstract
Cyanobacterial harmful algal blooms (CHABs) degrade water quality and may produce toxins. The distribution of CHABs can change rapidly due to variations in population dynamics and environmental conditions. Biological and ecological aspects of CHABs were studied in order to better understand CHABs dynamics. Field experiments were conducted near Hartington, Ontario, Canada in ponds dominated by Microcystis aeruginosa and CHABs floating experiments were conducted at Lake Taihu during the summers of 2015 and 2016. Single colonies composed of hundreds to thousands of cells with an average median of 0.2-0.5 mm in diameter were the basic form assumed by the Microcystis, and this remained the same throughout the growing season. Thorough mixing of the water column followed by calm conditions resulted in over 90% of the cyanobacteria floating after 1 h. Multiple colonies floated on the water surface in four types of assemblages: aggregates, ribbons, patches, and mats. It is the mats that are conventionally considered the blooming stage of cyanobacteria. Presence of CHABs on open water surfaces also depends on environmental influences such as direct and indirect wind effects. For example, field tests revealed that the surface coverage of CHABs can be reduced to half within an hour at wind speeds of 0.5 m/s. Because our findings indicated that blooming involves surface display of cyanobacteria essentially presenting as a two-dimensional plane under defined conditions, the use of surface imagery to quantify CHABs was justified. This is particularly important in light of the fact that traditional detection methods do not provide accurate distribution information. Nor do they portray CHABs events in a real-time manner due to limitations in on-demand surveillance and delays between sample time and analyzed results. Therefore, a new CHAB detection method using small unmanned aerial systems with consumer-grade cameras was developed at a maximum detection altitude of 80 m. When cyanobacteria were floating on the surface, CHABs detection through RGB band cameras and spectral enhancement techniques was efficient and accurate. Small unmanned aerial systems were capable of providing coverage up to 1 km2 per mission and the short intervals between sampling and results (approx. 2 h) allowed for the rapid analysis of data and for implementing follow-up monitoring or treatments. This method is very cost-effective at an estimate of as low as $100 CAD per mission with an average cyanobacterial detection accuracy of 86%. Thus, it is a good candidate method to fill the urgent need for CHABs detection, providing cost effective, rapid, and accurate information to improve risk management at a local level as well as to help quickly allocate resources for purposes of mitigation.
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Affiliation(s)
- Mingzhi Qu
- Department of Biology, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Stephen Anderson
- Department of Biology, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Pin Lyu
- Institute for Aerospace Studies, University of Toronto, Toronto, ON, M3H 5T6, Canada; College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
| | - Yasir Malang
- Institute for Aerospace Studies, University of Toronto, Toronto, ON, M3H 5T6, Canada
| | - Jizhou Lai
- College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
| | - Jianye Liu
- College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
| | - Bin Jiang
- College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
| | - Feng Xie
- School of Rail Transportation, Soochow University, Suzhou, 215131, China
| | - Hugh H T Liu
- Institute for Aerospace Studies, University of Toronto, Toronto, ON, M3H 5T6, Canada
| | - Daniel D Lefebvre
- Department of Biology, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Yuxiang S Wang
- Department of Biology, Queen's University, Kingston, ON, K7L 3N6, Canada.
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Ismaail NM, Shalaby AA, Ibraheem OA. Effect of age on Gaps-In-Noise test in pediatric population. Int J Pediatr Otorhinolaryngol 2019; 122:155-160. [PMID: 31029950 DOI: 10.1016/j.ijporl.2019.04.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 04/10/2019] [Accepted: 04/10/2019] [Indexed: 10/27/2022]
Abstract
OBJECTIVES The main objective was to examine the effect of central maturation on the auditory temporal resolution in a group of school-age children using Gaps-In-Noise test. METHODS The study involved 180 children (6-16 years) with normal hearing, average intelligence and language skills, and adequate scholastic achievement. Subjects were divided into four age subgroups. Investigations involved basic audiological evaluation, screening test battery for central auditory processing, and finally Gaps-In-Noise test. RESULTS Comparison of the four age subgroups revealed non-significant age effect on the Gaps-In-Noise test. The approximate gap detection threshold of children was comparable to that of adults. Equivalent data were obtained as a function of the ear, gender, list, and retest. CONCLUSION Central auditory maturation of the temporal resolution and hence the Gaps-In-Noise test has been established by age 5 years. Consequently, assessment of Gaps-In-Noise test in school-age children provided adult-like normative data. The stability of outcomes across different factors highlights the clinical validity of Gaps-In-Noise test in the assessment of temporal resolution deficit and follow-up after remediation.
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Affiliation(s)
- Naema M Ismaail
- Audio-vestibular Medicine Unit, Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine (Girls), University of AL-Azhar, Cairo, Egypt
| | - Amany A Shalaby
- Audio-vestibular Medicine Unit, Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine, University of Ain Shams, Cairo, Egypt
| | - Ola A Ibraheem
- Audio-vestibular Medicine Unit, Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine, University of Zagazig, Zagazig, Egypt.
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Lee HL, Li Z, Coulson EJ, Chuang KH. Ultrafast fMRI of the rodent brain using simultaneous multi-slice EPI. Neuroimage 2019; 195:48-58. [PMID: 30910726 DOI: 10.1016/j.neuroimage.2019.03.045] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 03/05/2019] [Accepted: 03/19/2019] [Indexed: 12/25/2022] Open
Abstract
Increasing spatial and temporal resolutions of functional MRI (fMRI) measurement has been shown to benefit the study of neural dynamics and functional interaction. However, acceleration of rodent brain fMRI using parallel and simultaneous multi-slice imaging techniques is hampered by the lack of high-density phased-array coils for the small brain. To overcome this limitation, we adapted phase-offset multiplanar and blipped-controlled aliasing echo planar imaging (EPI) to enable simultaneous multi-slice fMRI of the mouse brain using a single loop coil on a 9.4T scanner. Four slice bands of 0.3 × 0.3 × 0.5 mm3 resolution can be simultaneously acquired to cover the whole brain at a temporal resolution of 300 ms or the whole cerebrum in 150 ms. Instead of losing signal-to-noise ratio (SNR), both spatial and temporal SNR can be increased due to the increased k-space sampling compared to a standard single-band EPI. Task fMRI using a visual stimulation shows close to 80% increase of z-score and 4 times increase of activated area in the visual cortex using the multiband EPI due to the highly increased temporal samples. Resting-state fMRI shows reliable detection of bilateral connectivity by both single-band and multiband EPI, but no significant difference was found. Without the need of a dedicated hardware, we have demonstrated a practical method that can enable unparallelly fast whole-brain fMRI for preclinical studies. This technique can be used to increase sensitivity, distinguish transient response or acquire high spatiotemporal resolution fMRI.
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Affiliation(s)
- Hsu-Lei Lee
- Queensland Brain Institute, The University of Queensland, Brisbane, Australia; Centre of Advanced Imaging, The University of Queensland, Brisbane, Australia
| | - Zengmin Li
- Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Elizabeth J Coulson
- Queensland Brain Institute, The University of Queensland, Brisbane, Australia; School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Kai-Hsiang Chuang
- Queensland Brain Institute, The University of Queensland, Brisbane, Australia; Centre of Advanced Imaging, The University of Queensland, Brisbane, Australia.
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Demetriou L, Kowalczyk OS, Tyson G, Bello T, Newbould RD, Wall MB. A comprehensive evaluation of increasing temporal resolution with multiband-accelerated protocols and effects on statistical outcome measures in fMRI. Neuroimage 2018; 176:404-416. [PMID: 29738911 DOI: 10.1016/j.neuroimage.2018.05.011] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 04/30/2018] [Accepted: 05/02/2018] [Indexed: 11/25/2022] Open
Abstract
Accelerated functional Magnetic Resonance Imaging (fMRI) with 'multiband' protocols is now relatively widespread. These protocols can be used to dramatically reduce the repetition time (TR) and produce a time-series sampled at a higher temporal resolution, which may produce benefits in the statistical methods typically used to analyse fMRI data. We tested the effects of higher temporal resolutions for fMRI on statistical outcome measures in a comprehensive manner on two different MRI scanner platforms. Spatial resolution was maintained at a constant of 3 mm isotropic voxels, and an in-plane acceleration factor of 2 was used for all experiments. Experiment 1 tested a range of acceleration factors (1-6) against a standard EPI protocol on a single composite task that mapped a number of basic sensory, motor, and cognitive networks. Experiment 2 compared the standard protocol with acceleration factors of 2 and 3 on both resting-state and two task paradigms (an N-back task, and faces/places task), with a number of different analysis approaches. Results from experiment 1 showed modest but relatively inconsistent effects of the higher sampling rate on statistical outcome measures. Experiment 2 showed strong benefits of the multiband protocols on results derived from resting-state data, but more varied effects on results from the task paradigms. Notably, the multiband protocols were superior when Multi-Voxel Pattern Analysis was used to interrogate the faces/places data, but showed less benefit in conventional General Linear Model analyses of the same data. In general, ROI-derived measures of statistical effects benefitted only modestly from higher sampling resolution, with greater effects seen when using a measure of the top range of statistical values. Across both experiments, results from the two scanner platforms were broadly comparable. The statistical benefits of high temporal resolution fMRI with multiband protocols may therefore depend on a number of factors, including the nature of the investigation (resting-state vs. task-based), the experimental design, the particular statistical outcome measure, and the type of analysis used.
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Affiliation(s)
- Lysia Demetriou
- Imanova Centre for Imaging Sciences, Burlington Danes Building, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Oliwia S Kowalczyk
- Department of Psychology, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK
| | - Gabriella Tyson
- Department of Psychology, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK
| | - Thomas Bello
- Department of Biomedical Engineering, The University of Arizona, 1127 E. James E. Rogers Way, P.O. Box 210020, Tucson, AZ 85721-0020, USA
| | - Rexford D Newbould
- Imanova Centre for Imaging Sciences, Burlington Danes Building, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Matthew B Wall
- Imanova Centre for Imaging Sciences, Burlington Danes Building, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK; Division of Brain Sciences, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK; Clinical Psychopharmacology Unit, Research Department of Clinical, Educational and Health Psychology, University College London, Gower St, London, WC1E 6BT, UK.
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Nair PG, Basheer BM. Influence of temporal resolution skills in speech discrimination abilities of older subjects. Acta Otorhinolaryngol Ital 2018; 37:58-62. [PMID: 28374872 PMCID: PMC5384311 DOI: 10.14639/0392-100x-863] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 03/26/2016] [Indexed: 11/24/2022]
Abstract
Compromised temporal resolving power of the auditory system can be one of the main factors contributing to poor speech perception skills in the elderly. Very few of the earlier studies have systematically examined this aspect. Hence, the current study was designed with the following objectives: 1) To establish normative database of Gaps in Noise (GIN) test in elderly population in an Indian context. 2) To determine the relationship between speech discrimination skills and temporal resolution abilities in elderly individuals with normal hearing sensitivity. Thirty normal hearing elderly individuals (age range: 55-75 years; mean age: 59.86 ± 4.11 years) participated in the study. The audiological evaluation comprised of tympanometry, puretone and speech audiometry (Speech Reception Threshold-SRT, Speech Discrimination Score-SDS) and GIN. The results of the present study revealed mean Gap Detection Threshold (GDT) of 8.7 msec (SD = 3.38) in the right ear and 8.83 msec (SD = 2.86) in the left ear for the older participants. The mean Total Percentage Score (TPS) in the right ear was 47% (SD = 11.92) and 45% (SD = 11.29) in the left ear. These results suggest that temporal resolution abilities are poor in the elderly compared to the young and middle-aged group. There was no significant ear based difference on either GDT or TPS. The GDT was inversely correlated with speech discrimination performance. The TPS was positively correlated with SDS. This study clearly demonstrated a positive relationship between temporal resolution abilities and speech discrimination. The current database might be useful when assessing temporal resolution abilities in hearing impaired elderly individuals. Furthermore, all elderly individuals should undergo temporal resolution evaluation, irrespective of their hearing status, during audiological assessment.
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Affiliation(s)
- P G Nair
- Department of Speech pathology and Audiology, Amrita Institute of Medical Sciences and Research Centre, Amrita Vishwa Vidyapeetham University, Kochi, Kerala, India
| | - B M Basheer
- Mar Thoma College of Special Education, Kerala University of Health Sciences, Kasaragod, Kerala, India
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Saito H, Ito T, Tsujiguchi T, Yamaguchi M, Kashiwakura I. Characteristics of temporal resolution in 16- and 64-row computed tomography scanners. Radiol Phys Technol 2017; 11:100-108. [PMID: 29264837 DOI: 10.1007/s12194-017-0436-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 12/14/2017] [Accepted: 12/15/2017] [Indexed: 11/29/2022]
Abstract
This study aimed to analyze the temporal sensitivity profile (TSP) shapes and temporal resolutions of computed tomography (CT) and investigate the effect of a combination of a given rotation time and helical pitch on the TSP and image quality. The study was performed on 16- and 64-row CT scanners, and the TSP and temporal resolution were measured using the impulse method. A shorter gantry rotation time and larger helical pitch improved the temporal resolution of both CT scanners. Although the measured TSP shapes were dependent on the helical pitch, the maximum helical pitch did not improve the temporal resolution of either CT scanner. Different combinations of gantry rotation time and helical pitch yielded different TSP shapes such as the triangle, trapezoid, and rectangle, despite the use of equivalent scan speeds. We suggest that the different combinations of rotation time and helical pitch can greatly affect the TSP shapes.
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Affiliation(s)
- Hitoshi Saito
- Department of Radiology, Akita Kousei Medical Center, 1-1-1 Iijima Nishibukuro, Akita, 011-0948, Japan.
| | - Teruhiro Ito
- Department of Radiology, Akita Kousei Medical Center, 1-1-1 Iijima Nishibukuro, Akita, 011-0948, Japan
| | - Takakiyo Tsujiguchi
- Radiation Science, Hirosaki University Graduate School of Health Science, 66-1 Hon-cho, Hirosaki, Aomori, 036-8564, Japan
| | - Masaru Yamaguchi
- Radiation Science, Hirosaki University Graduate School of Health Science, 66-1 Hon-cho, Hirosaki, Aomori, 036-8564, Japan
| | - Ikuo Kashiwakura
- Radiation Science, Hirosaki University Graduate School of Health Science, 66-1 Hon-cho, Hirosaki, Aomori, 036-8564, Japan
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Takamura T, Hori M, Kamagata K, Kumamaru KK, Irie R, Hagiwara A, Hamasaki N, Aoki S. Slice-accelerated gradient-echo echo planar imaging dynamic susceptibility contrast-enhanced MRI with blipped CAIPI: effect of increasing temporal resolution. Jpn J Radiol 2017; 36:40-50. [PMID: 29086345 DOI: 10.1007/s11604-017-0695-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 10/13/2017] [Indexed: 01/02/2023]
Abstract
PURPOSE To assess the influence of high temporal resolution on the perfusion measurements and image quality of perfusion maps, by applying simultaneous-multi-slice acquisition (SMS) dynamic susceptibility contrast-enhanced (DSC) magnetic resonance imaging (MRI). MATERIALS AND METHODS DSC-MRI data using SMS gradient-echo echo planar imaging sequences in 10 subjects with no intracranial abnormalities were retrospectively analyzed. Three additional data sets with temporal resolution of 1.0, 1.5, and 2.0 s were created from the raw data sets of 0.5 s. Cerebral blood flow (CBF), cerebral blood volume, mean transit time (MTT), time to peak (TTP), and time to maximum tissue residue function (T max) measurements were performed, as was visual perfusion map analysis. The perfusion parameter for temporal resolution of 0.5 s (reference) was compared with each synthesized perfusion parameter. RESULTS CBF, MTT, and TTP values at temporal resolutions of 1.5 and 2.0 s differed significantly from the reference. The image quality of MTT, TTP, and T max maps deteriorated with decreasing temporal resolution. CONCLUSION The temporal resolution of DSC-MRI influences perfusion parameters and SMS DSC-MRI provides better image quality for MTT, TTP, and T max maps.
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Affiliation(s)
- Tomohiro Takamura
- Department of Radiology, Juntendo University School of Medicine, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
| | - Masaaki Hori
- Department of Radiology, Juntendo University School of Medicine, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Koji Kamagata
- Department of Radiology, Juntendo University School of Medicine, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Kanako K Kumamaru
- Department of Radiology, Juntendo University School of Medicine, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Ryusuke Irie
- Department of Radiology, Juntendo University School of Medicine, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Akifumi Hagiwara
- Department of Radiology, Juntendo University School of Medicine, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
- Department of Radiology, Graduate School of Medicine, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Nozomi Hamasaki
- Department of Radiology, Juntendo University School of Medicine, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Shigeki Aoki
- Department of Radiology, Juntendo University School of Medicine, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
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Baltus A, Wagner S, Wolters CH, Herrmann CS. Optimized auditory transcranial alternating current stimulation improves individual auditory temporal resolution. Brain Stimul 2017; 11:118-124. [PMID: 29079460 DOI: 10.1016/j.brs.2017.10.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 10/10/2017] [Accepted: 10/14/2017] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Temporal resolution of cortical, auditory processing mechanisms is suggested to be linked to peak frequency of neuronal gamma oscillations in auditory cortex areas (individual gamma frequency, IGF): Individuals with higher IGF tend to have better temporal resolution. HYPOTHESIS Modulating ongoing gamma activity with transcranial alternating current stimulation (tACS) is expected to improve performance in gap detection (GD) tasks (shorter GD thresholds) if the frequency is higher and to decrease GD performance (longer GD thresholds) if the frequency is lower than IGF. METHODS For 26 healthy participants the IGF and temporal resolution were identified using an auditory steady state response (ASSR) paradigm and a between-channel GD task. Finite element modelling was used to generate an optimized tACS electrode montage (one channel per hemisphere: FC5-TP7/P7 and FC6-TP8/P8). Afterwards, GD thresholds were examined during tACS (tACS frequency group A: above IGF, tACS frequency group B: below IGF). Relative changes of GD thresholds were compared between groups. Additionally, effects of tACS on oscillatory activity were investigated comparing relative changes of ASSR amplitudes before and after stimulation. RESULTS Performance of group-A-participants improved significantly during tACS in comparison to performance of group-B-participants. Significant relative changes of ASSR amplitudes were found in both groups. CONCLUSION The possibility to improve gap detection with individualized stimulation protocols for tACS further supports the link between oscillatory activity and temporal resolution, whereby the improvement of temporal resolution is particularly relevant for the clinical aspect of auditory tACS.
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Affiliation(s)
- Alina Baltus
- Experimental Psychology Lab, Cluster of Excellence "Hearing4all", European Medical School, Carl von Ossietzky University, Oldenburg, Germany
| | - Sven Wagner
- Institute for Biomagnetism and Biosignalanalysis, University of Muenster, Muenster, Germany
| | | | - Christoph Siegfried Herrmann
- Experimental Psychology Lab, Cluster of Excellence "Hearing4all", European Medical School, Carl von Ossietzky University, Oldenburg, Germany; Research Center Neurosensory Science, Carl von Ossietzky University, Oldenburg, Germany.
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Oleszkiewicz A, Meusel T, Güpfert M, Westermann B, Hummel T, Welge-Lüssen A. Olfactory deficits decrease the time resolution for trigeminal lateralization. Int J Psychophysiol 2017; 121:18-21. [PMID: 28918916 DOI: 10.1016/j.ijpsycho.2017.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 04/27/2017] [Accepted: 09/07/2017] [Indexed: 11/19/2022]
Abstract
OBJECTIVES To date the temporal resolution of the detection of almost simultaneously applied intranasal trigeminal stimuli is unknown. The aim of our study was to examine this temporal resolution in an/hyposmic subjects, who are known to have reduced trigeminal sensitivity and compare it with healthy controls. METHODS Participants were 20 posttraumatic an/hyposmic patients, and 23 healthy controls (matched with regard to sex and age). Olfactory function was tested psychophysically using the Sniffin´ Sticks test battery. Bilateral trigeminal stimulation was carried out using a birhinal high-precision olfactometer. The trigeminal stimulus used was CO₂ 60% v/v, the interstimulus interval ranged from 28 to 32s, stimulus duration was 200ms. Time-lags tested between right and left side of stimulation were at 40, 80, 120, 160 and 200ms. Subjects raised their left or right hand to indicate the side on which the stimulus had been perceived first. RESULTS In both groups the accuracy in the trigeminal lateralization task increased with the time-lag but normosmic subjects significantly outperformed an/hyposmics in the 200ms time-lag condition. Normosmics significantly exceeded 50% chance level at the time-lag of 80ms, whereas an/hyposmics were only able to score above chance starting from 120ms time-lag. Lateralization scores significantly decreased with age. CONCLUSIONS At a time lag of 200ms intranasal trigeminal stimuli can be lateralized. The reduced trigeminal sensitivity in patients with anosmia or hyposmia leads to an increased time lag required for correct perception of intranasal, almost simultaneously, applied stimuli.
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Affiliation(s)
- A Oleszkiewicz
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany; Institute of Psychology, University of Wroclaw, Wroclaw, Poland.
| | - T Meusel
- Department of Otorhinolaryngology, Head and Neck Surgery, University of Erlangen Medical School, Erlangen, Germany
| | - M Güpfert
- Department of Otorhinolaryngology, Head and Neck Surgery, University of Basel, Basel, Switzerland
| | - B Westermann
- Department of Neurosurgery, University of Basel, Basel, Switzerland
| | - T Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - A Welge-Lüssen
- Department of Otorhinolaryngology, Head and Neck Surgery, University of Basel, Basel, Switzerland
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Ronald KL, Sesterhenn TM, Fernandez-Juricic E, Lucas JR. The sensory substrate of multimodal communication in brown-headed cowbirds: are females sensory 'specialists' or 'generalists'? J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2017; 203:935-943. [PMID: 28819686 DOI: 10.1007/s00359-017-1203-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 07/31/2017] [Accepted: 08/01/2017] [Indexed: 12/16/2022]
Abstract
Many animals communicate with multimodal signals. While we have an understanding of multimodal signal production, we know relatively less about receiver filtering of multimodal signals and whether filtering capacity in one modality influences filtering in a second modality. Most multimodal signals contain a temporal element, such as change in frequency over time or a dynamic visual display. We examined the relationship in temporal resolution across two modalities to test whether females are (1) sensory 'specialists', where a trade-off exists between the sensory modalities, (2) sensory 'generalists', where a positive relationship exists between the modalities, or (3) whether no relationship exists between modalities. We used female brown-headed cowbirds (Molothrus ater) to investigate this question as males court females with an audiovisual display. We found a significant positive relationship between female visual and auditory temporal resolution, suggesting that females are sensory 'generalists'. Females appear to resolve information well across multiple modalities, which may select for males that signal their quality similarly across modalities.
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Affiliation(s)
- Kelly L Ronald
- Purdue University, 915 West State Street, West Lafayette, IN, USA. .,Indiana University, 1001 East 3rd Street, Bloomington, IN, USA.
| | - Timothy M Sesterhenn
- Purdue University, 915 West State Street, West Lafayette, IN, USA.,Morningside College, 1501 Morningside Avenue, Sioux City, IA, USA
| | | | - Jeffrey R Lucas
- Purdue University, 915 West State Street, West Lafayette, IN, USA
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Abstract
PURPOSE OF REVIEW This review aims to highlight the general and specific strengths and limitations of intraoperative 3D echocardiography. This article explains the value of real-time three-dimensional transesophageal echocardiography (RT 3D TEE) during cardiac surgery and cardiac interventions. RECENT FINDINGS Recently published recommendations and guidelines include the use of RT 3D TEE. RT 3 D TEE provides additional value particularly for guidance during cardiac interventions (i.e., transcatheter mitral valve repair, left atrial appendix and atrial septal defect closures), assessment of the mitral valve in surgical repair, measurement of left ventricular outflow tract area for transcatheter valvular replacements, and estimating right and left ventricular volumes and function. The exact localization of paravalvular leakage is another strength of RT 3D TEE. The major limitation is the reduced temporal resolution compared to 2D TEE. SUMMARY Three-dimensional echocardiography is a powerful tool that improves communication and accurate measurements of cardiac structures.
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Affiliation(s)
- Edwin Wilberforce Turton
- Department of Anesthesiology and Intensive Care Medicine, Heart Center Leipzig, Struempellstr 39, 04289 Leipzig, Germany
| | - Jörg Ender
- Department of Anesthesiology and Intensive Care Medicine, Heart Center Leipzig, Struempellstr 39, 04289 Leipzig, Germany
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Lu HD, Chen G, Cai J, Roe AW. Intrinsic signal optical imaging of visual brain activity: Tracking of fast cortical dynamics. Neuroimage 2017; 148:160-8. [PMID: 28063974 DOI: 10.1016/j.neuroimage.2017.01.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 12/29/2016] [Accepted: 01/03/2017] [Indexed: 11/21/2022] Open
Abstract
Hemodynamic-based brain imaging techniques are typically incapable of monitoring brain activity with both high spatial and high temporal resolutions. In this study, we have used intrinsic signal optical imaging (ISOI), a relatively high spatial resolution imaging technique, to examine the temporal resolution of the hemodynamic signal. We imaged V1 responses in anesthetized monkey to a moving light spot. Movies of cortical responses clearly revealed a focus of hemodynamic response traveling across the cortical surface. Importantly, at different locations along the cortical trajectory, response timecourses maintained a similar tri-phasic shape and shifted sequentially across cortex with a predictable delay. We calculated the time between distinguishable timecourses and found that the temporal resolution of the signal at which two events can be reliably distinguished is about 80 milliseconds. These results suggest that hemodynamic-based imaging is suitable for detecting ongoing cortical events at high spatial resolution and with temporal resolution relevant for behavioral studies.
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