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Jokar M, Rahmanian V, Golestani N, Raziee Y, Farhoodi M. The Global Seroprevalence of Equine Brucellosis: A Systematic Review and Meta-analysis Based on Publications From 1990 to 2022. J Equine Vet Sci 2023; 123:104227. [PMID: 36649828 DOI: 10.1016/j.jevs.2023.104227] [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: 09/17/2022] [Revised: 01/11/2023] [Accepted: 01/11/2023] [Indexed: 01/15/2023]
Abstract
Brucellosis, a bacterial infection caused by Brucella spp., is a widespread zoonosis concerning human and animal health. In equines, brucellosis may occur asymptomatically or with clinical signs such as arthritis, bursitis, and tenosynovitis. This study aims to ascertain the overall seroprevalence of equine brucellosis and its related factors, including geographic region, serological detection method, equine's species, gender, age, and body condition. This is because equine brucellosis is a zoonotic infection with significant epidemiological implications. The systematic literature search was conducted from January 1, 1990, to April 1, 2022, in the following electronic databases: Google Scholar, Scopus, Pub Med, Science Direct, Web of Science, Embase, Springer, and ProQuest. Based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA) and inclusion criteria, 49 qualified studies were acquired from several countries. Because Egger's test result and the asymmetry in the funnel plot indicated significant publication bias, the meta-analysis model was corrected using the trim-and-fill method. After correction, the pooled seroprevalence of equine brucellosis was 1.92% (95% CI, 0.67-3.79; estimated by the random effect model). Based on meta-regression analysis, the probable heterogeneity factors may be geographic areas (continents and countries). The brucellosis seroprevalence in equines was the lowest in Europe (0%, 95% CI, 0-0.1) and the highest in Asia (10.03%, 95% CI, 8-12.9). The highest overall estimate of seroprevalence of Brucella infection in equines based on a subset of serological tests was made using the serum agglutination test (10.2%, 95% CI, 7.7-13.4). The combined seroprevalence of brucellosis in donkeys (7.3%, 95% CI, 4.9-9.7) was higher than in other equine species. The overall seroprevalence of brucellosis in female equines was significantly higher than in males (OR = 1.437; 95% CI, 1.025-2.014); despite this, the overall seroprevalence had no significant difference based on other risk factors such as age and body condition. Understanding the epidemiology of this zoonotic infection in equines is critical for one-health integration. In addition, this study's results may be appropriate for controlling and managing equine brucellosis.
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Affiliation(s)
- Mohammad Jokar
- Faculty of Veterinary Medicine, Karaj Branch, Islamic Azad University, Karaj, Iran
| | - Vahid Rahmanian
- Department of Public Health, Torbat Jam Faculty of Medical Sciences, Torbat Jam, Iran.
| | - Nadia Golestani
- Department of Animal Biosciences, Ontario Agriculture College, University of Guelph, Guelph, Canada
| | - Yasamin Raziee
- Faculty of Veterinary Medicine, Karaj Branch, Islamic Azad University, Karaj, Iran
| | - Mehran Farhoodi
- Department of Clinical Sciences, Karaj Branch, Islamic Azad University, Karaj, Iran
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McCrae P, Spong H, Golestani N, Mahnam A, Bashura Y, Pearson W. Validation of an Equine Smart Textile System for Heart Rate Variability: A Preliminary Study. Animals (Basel) 2023; 13:ani13030512. [PMID: 36766401 PMCID: PMC9913118 DOI: 10.3390/ani13030512] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/11/2023] [Accepted: 01/28/2023] [Indexed: 02/04/2023] Open
Abstract
Electrocardiograms (ECGs), and associated heart rate (HR) and heart rate variability (HRV) measurements, are essential in assessing equine cardiovascular health and fitness. Smart textiles have gained popularity, but limited validation work has been conducted. Therefore, the objective of this study was to compare HR and HRV data obtained using a smart textile system (Myant) to the gold-standard telemetric device (Televet). Simultaneous ECGs were obtained using both systems in seven horses at rest and during a submaximal exercise test. Bland-Altman tests were used to assess agreement between the two devices. Strong to perfect correlations without significant differences between the two devices were observed for all metrics assessed. During exercise, mean biases of 0.31 bpm (95% limits of agreement: -1.99 to 2.61) for HR, 1.43 ms (-11.48 to 14.33) for standard deviation of R-R intervals (SDRR), and 0.04 (-2.30 to 2.38) for the HRV triangular index (TI) were observed. A very strong correlation was found between the two devices for HR (r = 0.9993, p < 0.0001) and for HRV parameters (SDRR r = 0.8765, p < 0.0001; TI r = 0.8712, p < 0.0001). This study demonstrates that a smart textile system is reliable for assessment of HR and HRV of horses at rest and during submaximal exercise.
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Affiliation(s)
- Persephone McCrae
- Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Hannah Spong
- Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Nadia Golestani
- Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Amin Mahnam
- Department of Research and Development, Myant Inc., Toronto, ON M9W 1B6, Canada
| | - Yana Bashura
- Department of Research and Development, Myant Inc., Toronto, ON M9W 1B6, Canada
| | - Wendy Pearson
- Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada
- Correspondence:
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Golestani N, Khoshkhoo PH, Hosseini H, Azad GA. Detection and identification of Chlamydia spp. from pigeons in Iran by nested PCR and sequencing. Iran J Microbiol 2020; 12:331-337. [PMID: 32994905 PMCID: PMC7502139 DOI: 10.18502/ijm.v12i4.3937] [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] [Indexed: 11/24/2022]
Abstract
Background and Objectives Chlamydia psittaci, an obligate intracellular, Gram-negative zoonotic pathogen, has eight serovars and nine genotypes isolated from avian species with higher frequency in parrots and pigeons. The aim of this study was to characterize Chlamydia spp. using nested PCR and sequencing. Materials and Methods A total of 270 pharyngeal swab samples collected randomly from asymptomatic pigeons of 30 pigeon aviaries in Tehran province. DNA was extracted with specific kit and amplified by specific primers in the first PCR and outer membrane protein A (ompA) gene in the second PCR. Positive samples were sequenced and phylogenetic tree analyzed based on the ompA gene. Results Records showed that 16 of 30 (53%) pigeon aviaries were positive for Chlamydia spp. Phylogenetic tree analysis revealed that 15 of 16 (93.7%) positive samples, belonged to C. psittaci genotype B whereas the other sample belonged to C. avium. C. psittaci detected in 50% of pigeon aviaries that is high rate in Tehran province. Conclusion As C. psittaci is a zoonosis and life threaten pathogen for human being, these results indicate the significance of it detection in asymptomatic pigeons. Also, this is the first report of Chlamydia avium presence in Iranian pigeons which its zoonotic potential is still unknown.
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Affiliation(s)
- Nadia Golestani
- Department of Clinical Sciences, School of Veterinary Medicine, Karaj Branch, Islamic Azad University, Karaj, Iran
| | - Payam Haghighi Khoshkhoo
- Department of Clinical Sciences, School of Veterinary Medicine, Karaj Branch, Islamic Azad University, Karaj, Iran
| | - Hossein Hosseini
- Department of Clinical Sciences, School of Veterinary Medicine, Karaj Branch, Islamic Azad University, Karaj, Iran
| | - Gita Akbari Azad
- Department of Clinical Sciences, School of Veterinary Medicine, Karaj Branch, Islamic Azad University, Karaj, Iran
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Mogheiseh A, Derakhshandeh A, Batebi E, Golestani N, Moshiri A. Co-relation of estrous cycle phases with uterine bacterial and fungal flora in non-pregnant female laboratory rabbits. Iran J Vet Res 2017; 18:128-133. [PMID: 28775754 PMCID: PMC5534257] [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: 07/11/2015] [Revised: 08/09/2016] [Accepted: 12/24/2016] [Indexed: 06/07/2023]
Abstract
This study was designed to investigate the relationship between the estrous cycle phases with uterine bacterial and fungal flora in non-pregnant female rabbits. Thirty laboratory mature multiparous rabbits were used for this purpose. Samples from uterine lavage for culture of bacteria and fungi were collected at different stages of estrous cycle (based on vaginal cytology), and histopathological observations were evaluated based on the scoring system used for defining the infection of the uterus. Various types of bacteria and fungi were isolated from rabbits at all stages of estrous cycle. The widest variety of bacteria and fungi was isolated at Di-estrous stage and the lowest variety was detected at estrous stage. Klebsiella oxytoca as well as yeast have been isolated at all stages of estrous cycle. This study showed that infection with K. oxytoca and yeast had no relationship with different stages of estrous cycle but other bacteria and fungus were associated with one or more stages of the estrous cycle in rabbits.
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Affiliation(s)
- A. Mogheiseh
- Department of Clinical Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran
| | - A. Derakhshandeh
- Department of Pathobiology, School of Veterinary Medicine, Shiraz University, Shiraz, Iran
| | - E. Batebi
- Veterinary Medicine Private Practitioner, Shiraz, Iran
| | - N. Golestani
- Graduated from School of Veterinary Medicine, Shiraz University, Shiraz, Iran
| | - A. Moshiri
- Veterinary Medicine Private Practitioner, Shiraz, Iran
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Golestani N, EtehadTavakol M, Ng EYK. Level set method for segmentation of infrared breast thermograms. EXCLI J 2014; 13:241-51. [PMID: 26417258 PMCID: PMC4464455] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Accepted: 02/07/2014] [Indexed: 11/14/2022]
Abstract
Breast thermography is a physiological test that provides information based on the temperature changes in breast. It records the temperature distribution of a body using the infrared radiation emitted by the surface of that body. Precancerous tissue and the area around a cancerous tumor have higher temperature due to angiogenesis, and higher chemical and blood vessel activity than a normal breast; hence breast thermography has potential to detect early abnormal changes in breast tissues. It can detect the first sign of forming up cancer before mammography can detect. The thermal information can be shown in a pseudo colored image where each color represents a specific range of temperature. Various methods can be applied to extract hot regions for detecting suspected regions of interests in the breast infrared images and potentially suspicious tissues. Image segmentation techniques can play an important role to segment and extract these regions in the breast infrared images. Shape, size and borders of the hottest regions of the images can help to determine features which are used to detect abnormalities. In this paper, three image segmentation methods: k-means, fuzzy c-means and level set are discussed and compared. These three methods are tested for different cases such as fibrocystic, inflammatory cancer cases. The hottest regions of thermal breast images in all cases are extracted and compared to the original images. According to the results, level set method is a more accurate approach and has potential to extract almost exact shape of tumors.
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Affiliation(s)
- N Golestani
- Electrical and Computer Engineering Department, Isfahan University of Technology, Iran, Isfahan, 84154, Iran; e-mail:
| | - M EtehadTavakol
- Medical Image and Signal Processing Research Centre, Isfahan University of Medical Sciences, Isfahan 81745-319, Iran; e-mail:
| | - EYK Ng
- School of Mechanical and Aerospace Engineering, College of Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore,*To whom correspondence should be addressed: EYK Ng, School of Mechanical and Aerospace Engineering, College of Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore, E-mail:
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Evans S, Kyong JS, Rosen S, Golestani N, Warren JE, McGettigan C, Mourão-Miranda J, Wise RJS, Scott SK. The pathways for intelligible speech: multivariate and univariate perspectives. Cereb Cortex 2013; 24:2350-61. [PMID: 23585519 PMCID: PMC4128702 DOI: 10.1093/cercor/bht083] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [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] [Indexed: 11/30/2022] Open
Abstract
An anterior pathway, concerned with extracting meaning from sound, has been identified in nonhuman primates. An analogous pathway has been suggested in humans, but controversy exists concerning the degree of lateralization and the precise location where responses to intelligible speech emerge. We have demonstrated that the left anterior superior temporal sulcus (STS) responds preferentially to intelligible speech (Scott SK, Blank CC, Rosen S, Wise RJS. 2000. Identification of a pathway for intelligible speech in the left temporal lobe. Brain. 123:2400–2406.). A functional magnetic resonance imaging study in Cerebral Cortex used equivalent stimuli and univariate and multivariate analyses to argue for the greater importance of bilateral posterior when compared with the left anterior STS in responding to intelligible speech (Okada K, Rong F, Venezia J, Matchin W, Hsieh IH, Saberi K, Serences JT,Hickok G. 2010. Hierarchical organization of human auditory cortex: evidence from acoustic invariance in the response to intelligible speech. 20: 2486–2495.). Here, we also replicate our original study, demonstrating that the left anterior STS exhibits the strongest univariate response and, in decoding using the bilateral temporal cortex, contains the most informative voxels showing an increased response to intelligible speech. In contrast, in classifications using local “searchlights” and a whole brain analysis, we find greater classification accuracy in posterior rather than anterior temporal regions. Thus, we show that the precise nature of the multivariate analysis used will emphasize different response profiles associated with complex sound to speech processing.
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Affiliation(s)
- S Evans
- Institute of Cognitive Neuroscience, MRC Cognition and Brain Sciences Unit, Cambridge CB2 7EF, UK
| | - J S Kyong
- Department of Speech, Hearing and Phonetic Sciences
| | - S Rosen
- Department of Speech, Hearing and Phonetic Sciences
| | - N Golestani
- Institute of Cognitive Neuroscience, Department of Clinical Neuroscience, University Medical School, Geneva CH-1211, Switzerland
| | - J E Warren
- Computational, Cognitive and Clinical Neuroimaging Laboratory, Imperial College London, London W12 0NN, UK
| | - C McGettigan
- Institute of Cognitive Neuroscience, Department of Psychology, Royal Holloway University, University of London, Egham TW20 0EX, UK and
| | - J Mourão-Miranda
- Department of Computer Science, Centre for Computational Statistics and Machine Learning, University College London, London WC1E 6BT, UK Centre for Neuroimaging Sciences, Institute of Psychiatry, King's College, London SE5 8AF, UK
| | - R J S Wise
- Computational, Cognitive and Clinical Neuroimaging Laboratory, Imperial College London, London W12 0NN, UK
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Tabandeh MR, Golestani N, Kafi M, Hosseini A, Saeb M, Sarkoohi P. Gene expression pattern of adiponectin and adiponectin receptors in dominant and atretic follicles and oocytes screened based on brilliant cresyl blue staining. Anim Reprod Sci 2012; 131:30-40. [PMID: 22391295 DOI: 10.1016/j.anireprosci.2012.02.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2011] [Revised: 01/17/2012] [Accepted: 02/02/2012] [Indexed: 12/17/2022]
Abstract
Adiponectin and its receptors (AdipoR1 and AdipoR2) are novel endocrine systems that act at various levels to control male and female fertility. The aim of this study was to determine whether adiponectin and its receptors gene expression levels differ between dominant follicle (DF) and atretic follicle (AF) and also between oocytes which were stained positively and negatively with brilliant cresyl blue (BCB(+) and BCB(-)). Based on estradiol/progesterone ratio, follicles from ovaries were classified as AFs and DFs. The stages of estrous cycle (follicular or luteal phases) were defined by macroscopic observation of the ovaries and the uterus. Oocytes were stained with BCB for 90 min. The relative expression of adiponectin, AdipoR1 and AdipoR2 mRNA in theca and cumulus cells and oocytes of different follicles were determined by quantitative real time PCR. Adiponectin and its receptors genes were clearly expressed higher (P<0.05) in theca and cumulus cells and oocytes of DFs than those of AFs during the follicular and luteal phases. BCB(+) oocytes showed a higher (P<0.05) expression of adiponectin and its receptors compared with their BCB(-) counterparts. Positive correlation (r>0.725, P<0.001) was observed between adiponectin mRNA level in ovarian cells of DFs and follicular fluid E2 concentration in follicular phase. Adiponectin mRNA abundance in ovarian cells of AFs showed a significant negative correlation with follicular fluid progesterone concentration in follicular and luteal phases (r<-0.731, P<0.001). This work has revealed the novel association of adiponectin and its receptors genes with follicular dominance and oocyte competence, thereby opening several new avenues of research into the mechanisms of dominance and competence in animal and human.
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Affiliation(s)
- M R Tabandeh
- Department of Biochemistry and Molecular Biology, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Iran.
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Rodrigo S, Naggara O, Oppenheim C, Golestani N, Poupon C, Cointepas Y, Mangin JF, Le Bihan D, Meder JF. Human subinsular asymmetry studied by diffusion tensor imaging and fiber tracking. AJNR Am J Neuroradiol 2007; 28:1526-31. [PMID: 17846205 PMCID: PMC8134399 DOI: 10.3174/ajnr.a0584] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND AND PURPOSE Our aim was to improve our understanding of the subinsular white matter microstructural asymmetries in healthy right-handed subjects. Structural brain asymmetries could be related to functional asymmetries such as hemisphere language dominance or handedness. Besides the known gray matter asymmetries, white matter asymmetries could also play a key role in the understanding of hemispheric specialization, notably that of language. MATERIALS AND METHODS White matter asymmetries were studied by diffusion tensor imaging at 1.5T (41 diffusion-gradient directions; b-value set to 700 s/mm(2); matrix, 128(2); in-plane resolution, 1.875 x 1.875 mm; section thickness, 2.0 mm) and fiber tracking (BrainVISA software). The main white matter bundles passing through the subinsular area were segmented, and fractional anisotropy (FA) was measured along each of the segmented bundles. RESULTS In line with published results, we found an asymmetry of the arcuate fasciculus and the subinsular white matter, namely left-greater-than-right FA in right-handed controls. Furthermore, by segmenting major tracts coursing through this region, we showed that the subinsular portions of the uncinate fasciculus (UF) and the inferior occipitofrontal fasciculus (IOF) contribute to this FA asymmetry. Those tracts have been reported to be likely implicated in the language network. CONCLUSION Because the left hemisphere hosts language functions in most right-handers, the significant leftward asymmetry observed within the arcuate fasciculus, the subinsular part of the UF and IOF may be related to the hemispheric specialization for language.
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Affiliation(s)
- S Rodrigo
- Département d'Imagerie Morphologique et Fonctionnelle, Faculté de Médecine, Université Paris-Descartes, Centre Hospitalier Sainte-Anne, Paris, France
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Rodrigo S, Oppenheim C, Chassoux F, Golestani N, Cointepas Y, Poupon C, Semah F, Mangin JF, Le Bihan D, Meder JF. Uncinate fasciculus fiber tracking in mesial temporal lobe epilepsy. Initial findings. Eur Radiol 2007; 17:1663-8. [PMID: 17219141 DOI: 10.1007/s00330-006-0558-x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2006] [Revised: 11/24/2006] [Accepted: 12/01/2006] [Indexed: 10/23/2022]
Abstract
In temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS), ictal discharge spread to the frontal and insulo-perisylvian cortex is commonly observed. The implication of white matter pathways in this propagation has not been investigated. We compared diffusion tensor imaging (DTI) measurements along the uncinate fasciculus (UF), a major tract connecting the frontal and temporal lobes, in patients and controls. Ten right-handed patients referred for intractable TLE due to a right HS were investigated on a 1.5-T MR scanner including a DTI sequence. All patients had interictal fluorodeoxyglucose PET showing an ipsilateral temporal hypometabolism associated with insular and frontal or perisylvian hypometabolism. The controls consisted of ten right-handed healthy subjects. UF fiber tracking was performed, and its fractional anisotropy (FA) values were compared between patients and controls, separately for the right and left UF. The left-minus-right FA UF asymmetry index was computed to test for intergroup differences. Asymmetries were found in the control group with right-greater-than-left FA. This asymmetrical pattern was lost in the patient group. Right FA values were lower in patients with right HS versus controls. Although preliminary, these findings may be related to the preferential pathway of seizure spread from the mesial temporal lobe to frontal and insulo-perisylvian areas.
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Affiliation(s)
- S Rodrigo
- Département d'Imagerie Morphologique et Fonctionnelle, Université Paris-Descartes, Faculté de Médecine, Centre Hospitalier Sainte-Anne, 75674 Paris, France
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El Kouby V, Cointepas Y, Poupon C, Rivière D, Golestani N, Poline JB, Le Bihan D, Mangin JF. MR diffusion-based inference of a fiber bundle model from a population of subjects. ACTA ACUST UNITED AC 2006; 8:196-204. [PMID: 16685846 DOI: 10.1007/11566465_25] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
This paper proposes a method to infer a high level model of the white matter organization from a population of subjects using MR diffusion imaging. This method takes as input for each subject a set of trajectories stemming from any tracking algorithm. Then the inference results from two nested clustering stages. The first clustering converts each individual set of trajectories into a set of bundles supposed to represent large white matter pathways. The second clustering matches these bundles across subjects in order to provide a list of candidates for the bundle model. The method is applied on a population of eleven subjects and leads to the inference of 17 such candidates.
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Affiliation(s)
- V El Kouby
- Service Hospitalier Frederic Joliot, CEA, 91401 Orsay, France.
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Naggara O, Rodrigo S, Oppenheim C, Golestani N, Pierrefitte S, Poupon C, Meder J. CO-22 - Apport de la tractographie pour l’étude de la substance blanche sous insulaire. J Neuroradiol 2006. [DOI: 10.1016/s0150-9861(06)77142-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Perrin M, Poupon C, Cointepas Y, Rieul B, Golestani N, Pallier C, Rivière D, Constantinesco A, Le Bihan D, Mangin JF. Fiber tracking in q-ball fields using regularized particle trajectories. Inf Process Med Imaging 2005; 19:52-63. [PMID: 17354684 DOI: 10.1007/11505730_5] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Most of the approaches dedicated to fiber tracking from diffusion-weighted MR data rely on a tensor model. However, the tensor model can only resolve a single fiber orientation within each imaging voxel. New emerging approaches have been proposed to obtain a better representation of the diffusion process occurring in fiber crossing. In this paper, we adapt a tracking algorithm to the q-ball representation, which results from a spherical Radon transform of high angular resolution data. This algorithm is based on a Monte-Carlo strategy, using regularized particle trajectories to sample the white matter geometry. The method is validated using a phantom of bundle crossing made up of haemodialysis fibers. The method is also applied to the detection of the auditory tract in three human subjects.
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Affiliation(s)
- M Perrin
- Service Hospitalier Frédéric Joliot, CEA, 91401 Orsay, France.
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Abstract
In three experiments, we examined memory for responses and stimuli experienced in a single direct psychophysical scaling session in which subjects made absolute magnitude estimations of the loudnesses of pure tones. Recall of scaling responses was found to be accurate for the softest and loudest stimuli, but systematically greater than actual judgments for the intermediate stimulus amplitudes, yielding distorted psychophysical functions for the recall data which nonetheless had the same power function exponent as that for the judged stimuli. Also, memory for the range of stimulus amplitudes was fairly accurate, but subjects could not distinguish between judged and nonjudged amplitudes within that range. The results are consistent with the role of extreme stimuli as anchors for judgment, and indicate that memories for these stimuli and responses made to them can be expected to influence future scaling judgments. These results also are consistent with the uncertainty hypothesis of mnemophysics.
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Affiliation(s)
- L M Ward
- Department of Psychology, University of British Columbia, 2136 West Mall, Vancouver, BC V6T 1Z4, Canada.
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Abstract
Several successful theories of psychophysical judgment imply that exponents of power functions in scaling tasks should covary with measures of intensity resolution such as d' in the same tasks, whereas the prevailing metatheory of ideal psychophysical scaling asserts the independence of the two. In a direct test of this relationship, three prominent psychophysical scaling paradigms were studied: category judgment without an identification function, absolute magnitude estimation, and cross-modality matching with light intensity as the response continuum. Separate groups of subjects for each scaling paradigm made repeated judgments of the loudnesses of the pure tones that constituted each of two stimulus ensembles. The narrow- and wide-range ensembles shared six identical stimulus intensities in the middle of each set. Intensity resolution, as measured by d'-like distances, of these physically identical stimuli was significantly worse for the wide-range set for all three methods. Exponents of power functions fitted to geometric mean responses, and in magnitude estimation and cross-modality matching the geometric mean responses themselves, were also significantly smaller in the wide-range condition. The variation of power function exponents, and of psychophysical scale values, for stimulus intensities that were identical in the two stimulus sets with the intensities of other members of the ensembles is inconsistent with the metatheory on which modern psychophysical scaling practice is based, although it is consistent with other useful approaches to measurement of psychological magnitudes.
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Affiliation(s)
- L M Ward
- Department of Psychology, University of British Columbia, Vancouver, Canada.
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