1
|
Gonzalez V, Grant MG, Suzuki M, Christophers B, Rowland Williams J, Burdine RD. Cooperation between Nodal and FGF signals regulates zebrafish cardiac cell migration and heart morphogenesis. bioRxiv 2024:2024.01.05.574380. [PMID: 38260277 PMCID: PMC10802409 DOI: 10.1101/2024.01.05.574380] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Asymmetric vertebrate heart development is driven by an intricate sequence of morphogenetic cell movements, the coordination of which requires precise interpretation of signaling cues by heart primordia. Here we show that Nodal functions cooperatively with FGF during heart tube formation and asymmetric placement. Both pathways act as migratory stimuli for cardiac progenitor cells (CPCs), but FGF is dispensable for directing heart tube asymmetry, which is governed by Nodal. We further find that Nodal controls CPC migration by inducing left-right asymmetries in the formation of actin-based protrusions in CPCs. Additionally, we define a developmental window in which FGF signals are required for proper heart looping and show cooperativity between FGF and Nodal in this process. We present evidence FGF may promote heart looping through addition of the secondary heart field. Finally, we demonstrate that loss of FGF signaling affects proper development of the atrioventricular canal (AVC), which likely contributes to abnormal chamber morphologies in FGF-deficient hearts. Together, our data shed insight into how the spatiotemporal dynamics of signaling cues regulate the cellular behaviors underlying organ morphogenesis.
Collapse
Affiliation(s)
- Vanessa Gonzalez
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA, 08544
| | - Meagan G. Grant
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA, 08544
| | - Makoto Suzuki
- Amphibian Research Center, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashihiroshima, Hiroshima, Japan, 739-8526
| | - Briana Christophers
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA, 08544
| | - Jessica Rowland Williams
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA, 08544
- Current affiliation: National Institute for Student Success, at Georgia State University, Atlanta, GA 30303
| | - Rebecca D. Burdine
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA, 08544
| |
Collapse
|
2
|
Williams JR, Neal K, Alfayyadh A, Capin JJ, Khandha A, Manal K, Snyder-Mackler L, Buchanan TS. Patellofemoral contact forces and knee gait mechanics 3 months after ACL reconstruction are associated with cartilage degradation 24 months after surgery. Osteoarthritis Cartilage 2023; 31:96-105. [PMID: 36252943 PMCID: PMC9771964 DOI: 10.1016/j.joca.2022.10.007] [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] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 09/26/2022] [Accepted: 10/06/2022] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Evaluate patellofemoral cartilage health, as assessed by quantitative magnetic resonance imaging (qMRI) T2 relaxation times, 24-months after ACL reconstruction (ACLR) and determine if they were associated with patellofemoral contact forces and knee mechanics during gait 3 months after surgery. DESIGN Thirty individuals completed motion analysis during overground walking at a self-selected speed 3 months after ACLR. An EMG-driven neuromusculoskeletal model was used to determine muscle forces, which were then used in a previously described model to estimate patellofemoral contact forces. Biomechanical variables of interest included peak patellofemoral contact force, peak knee flexion angle and moment, and walking speed. These same participants underwent a sagittal bilateral T2 mapping qMRI scan 24-months after surgery. T2 relaxation times were estimated for both patellar and trochlear cartilage. Paired t-tests were used to compare T2 relaxation times between limbs while Pearson correlations and linear regressions were utilized to assess the association between the biomechanical variables of interest and T2 relaxation times. RESULTS Prolonged involved limb trochlear T2 relaxation times (vs uninvolved) were present 24-months after surgery, indicating worse cartilage health. No differences were detected in patellar cartilage. Significant negative associations were present within the involved limb for all the biomechanical variables of interest 3 months after ACLR and trochlear T2 relaxation times at 24-months. No associations were found in patellar cartilage or within the uninvolved limb. CONCLUSIONS Altered involved limb trochlear cartilage health is present 24-months after ACLR and may be related to patellofemoral loading and other walking gait mechanics 3 months after surgery.
Collapse
Affiliation(s)
- J R Williams
- Department of Mechanical Engineering, University of Delaware, Newark, DE, USA.
| | - K Neal
- Department of Mechanical Engineering, University of Delaware, Newark, DE, USA.
| | - A Alfayyadh
- Biomechanics and Movement Science, University of Delaware, Newark, DE, USA; Physical Therapy and Rehabilitation Department, Jouf University, Jouf, Saudi Arabia.
| | - J J Capin
- Department of Physical Therapy, Marquette University, Milwaukee, WI, USA.
| | - A Khandha
- Department of Biomedical Engineering, University of Delaware, Newark, DE, USA.
| | - K Manal
- Biomechanics and Movement Science, University of Delaware, Newark, DE, USA; Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA.
| | - L Snyder-Mackler
- Biomechanics and Movement Science, University of Delaware, Newark, DE, USA; Department of Biomedical Engineering, University of Delaware, Newark, DE, USA; Department of Physical Therapy, University of Delaware, Newark, DE, USA.
| | - T S Buchanan
- Department of Mechanical Engineering, University of Delaware, Newark, DE, USA; Biomechanics and Movement Science, University of Delaware, Newark, DE, USA; Department of Biomedical Engineering, University of Delaware, Newark, DE, USA.
| |
Collapse
|
3
|
Carollo RA, Aveline DC, Rhyno B, Vishveshwara S, Lannert C, Murphree JD, Elliott ER, Williams JR, Thompson RJ, Lundblad N. Observation of ultracold atomic bubbles in orbital microgravity. Nature 2022; 606:281-286. [PMID: 35585238 DOI: 10.1038/s41586-022-04639-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 03/14/2022] [Indexed: 11/09/2022]
Abstract
Substantial leaps in the understanding of quantum systems have been driven by exploring geometry, topology, dimensionality and interactions in ultracold atomic ensembles1-6. A system where atoms evolve while confined on an ellipsoidal surface represents a heretofore unexplored geometry and topology. Realizing an ultracold bubble-potentially Bose-Einstein condensed-relates to areas of interest including quantized-vortex flow constrained to a closed surface topology, collective modes and self-interference via bubble expansion7-17. Large ultracold bubbles, created by inflating smaller condensates, directly tie into Hubble-analogue expansion physics18-20. Here we report observations from the NASA Cold Atom Lab21 facility onboard the International Space Station of bubbles of ultracold atoms created using a radiofrequency-dressing protocol. We observe bubble configurations of varying size and initial temperature, and explore bubble thermodynamics, demonstrating substantial cooling associated with inflation. We achieve partial coverings of bubble traps greater than one millimetre in size with ultracold films of inferred few-micrometre thickness, and we observe the dynamics of shell structures projected into free-evolving harmonic confinement. The observations are among the first measurements made with ultracold atoms in space, using perpetual freefall to explore quantum systems that are prohibitively difficult to create on Earth. This work heralds future studies (in orbital microgravity) of the Bose-Einstein condensed bubble, the character of its excitations and the role of topology in its evolution.
Collapse
Affiliation(s)
- R A Carollo
- Department of Physics and Astronomy, Bates College, Lewiston, ME, USA
| | - D C Aveline
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - B Rhyno
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - S Vishveshwara
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - C Lannert
- Department of Physics, Smith College, Northampton, MA, USA.,Department of Physics, University of Massachusetts, Amherst, MA, USA
| | - J D Murphree
- Department of Physics and Astronomy, Bates College, Lewiston, ME, USA
| | - E R Elliott
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - J R Williams
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - R J Thompson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - N Lundblad
- Department of Physics and Astronomy, Bates College, Lewiston, ME, USA.
| |
Collapse
|
4
|
Rao SM, Galioto R, Sokolowski M, McGinley M, Freiburger J, Weber M, Dey T, Mourany L, Schindler D, Reece C, Miller DM, Bethoux F, Bermel RA, Williams JR, Levitt N, Phillips GA, Rhodes JK, Alberts J, Rudick RA. Multiple Sclerosis Performance Test: validation of self-administered neuroperformance modules. Eur J Neurol 2020; 27:878-886. [PMID: 32009276 DOI: 10.1111/ene.14162] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [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: 05/13/2019] [Revised: 10/07/2019] [Accepted: 12/03/2019] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE The purpose was to determine the test-retest reliability, practice effects, convergent validity and sensitivity to multiple sclerosis (MS) disability of neuroperformance subtests from the patient self-administered Multiple Sclerosis Performance Test (MSPT) designed to assess low contrast vision (Contrast Sensitivity Test, CST), upper extremity motor function (Manual Dexterity Test, MDT) and lower extremity motor function (Walking Speed Test, WST) and to introduce the concept of regression-based norms to aid clinical interpretation of performance scores using the MSPT cognition test (Processing Speed Test, PST) as an example. METHODS Substudy 1 assessed test-retest reliability, practice effects and convergent validity of the CST, MDT and WST in 30 MS patients and 30 healthy controls. Substudy 2 examined sensitivity to MS disability in over 600 MS patients as part of their routine clinic assessment. Substudy 3 compared performance on the PST in research volunteers and clinical samples. RESULTS The CST, MDT and WST were shown to be reliable, valid and sensitive to MS outcomes. Performance was comparable to technician-administered testing. PST performance was poorer in the clinical sample compared with the research volunteer sample. CONCLUSIONS The self-administered MSPT neuroperformance modules produce reliable, objective metrics that can be used in clinical practice and support outcomes research. Published studies which require patient voluntary consent may underestimate the rate of cognitive dysfunction observed in a clinical setting.
Collapse
Affiliation(s)
- S M Rao
- Mellen Center for Multiple Sclerosis, Neurological Institute, Cleveland Clinic Foundation, Cleveland, OH, USA.,Lou Ruvo Center for Brain Health, Neurological Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - R Galioto
- Mellen Center for Multiple Sclerosis, Neurological Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - M Sokolowski
- Lou Ruvo Center for Brain Health, Neurological Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - M McGinley
- Mellen Center for Multiple Sclerosis, Neurological Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - J Freiburger
- Lou Ruvo Center for Brain Health, Neurological Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - M Weber
- Mellen Center for Multiple Sclerosis, Neurological Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - T Dey
- Department of Quantitative Health Sciences, Learner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - L Mourany
- Mellen Center for Multiple Sclerosis, Neurological Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - D Schindler
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA.,Qr8Health, Boston, MA, USA
| | - C Reece
- Lou Ruvo Center for Brain Health, Neurological Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - D M Miller
- Mellen Center for Multiple Sclerosis, Neurological Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - F Bethoux
- Mellen Center for Multiple Sclerosis, Neurological Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - R A Bermel
- Mellen Center for Multiple Sclerosis, Neurological Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | | | | | | | | | - J Alberts
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | | |
Collapse
|
5
|
Cardenas LM, Bhogal A, Chadwick DR, McGeough K, Misselbrook T, Rees RM, Thorman RE, Watson CJ, Williams JR, Smith KA, Calvet S. Nitrogen use efficiency and nitrous oxide emissions from five UK fertilised grasslands. Sci Total Environ 2019; 661:696-710. [PMID: 30684838 PMCID: PMC6383039 DOI: 10.1016/j.scitotenv.2019.01.082] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [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: 10/18/2018] [Revised: 12/31/2018] [Accepted: 01/08/2019] [Indexed: 05/15/2023]
Abstract
Intensification of grasslands is necessary to meet the increasing demand of livestock products. The application of nitrogen (N) on grasslands affects the N balance therefore the nitrogen use efficiency (NUE). Emissions of nitrous oxide (N2O) are produced due to N fertilisation and low NUE. These emissions depend on the type and rates of N applied. In this study we have compiled data from 5 UK N fertilised grassland sites (Crichton, Drayton, North Wyke, Hillsborough and Pwllpeiran) covering a range of soil types and climates. The experiments evaluated the effect of increasing rates of inorganic N fertiliser provided as ammonium nitrate (AN) or calcium ammonium nitrate (CAN). The following fertiliser strategies were also explored for a rate of 320 kg N ha-1: using the nitrification inhibitor dicyandiamide (DCD), changing to urea as an N source and splitting fertiliser applications. We measured N2O emissions for a full year in each experiment, as well as soil mineral N, climate data, pasture yield and N offtake. N2O emissions were greater at Crichton and North Wyke whereas Drayton, Hillsborough and Pwllpeiran had the smallest emissions. The resulting average emission factor (EF) of 1.12% total N applied showed a range of values for all the sites between 0.6 and 2.08%. NUE depended on the site and for an application rate of 320 kg N ha-1, N surplus was on average higher than 80 kg N ha-1, which is proposed as a maximum by the EU Nitrogen Expert Panel. N2O emissions tended to be lower when urea was applied instead of AN or CAN, and were particularly reduced when using urea with DCD. Finally, correlations between the factors studied showed that total N input was related to Nofftake and Nexcess; while cumulative emissions and EF were related to yield scaled emissions.
Collapse
Affiliation(s)
- L M Cardenas
- Rothamsted Research, Okehampton, Devon, EX20 2SB, UK.
| | - A Bhogal
- ADAS Boxworth, Battlegate Road, Boxworth, Cambridge CB23 4NN, UK
| | - D R Chadwick
- School of Natural Sciences, Bangor University, Bangor LL57 2UW, UK
| | - K McGeough
- Agri-Food and Biosciences Institute, 18a, Newforge Lane, BT9 5PX Belfast, UK
| | - T Misselbrook
- Rothamsted Research, Okehampton, Devon, EX20 2SB, UK
| | - R M Rees
- Scotland's Rural College (SRUC), King's Buildings, West Mains Road, Edinburgh EH9 3JG, UK
| | - R E Thorman
- ADAS Boxworth, Battlegate Road, Boxworth, Cambridge CB23 4NN, UK
| | - C J Watson
- Agri-Food and Biosciences Institute, 18a, Newforge Lane, BT9 5PX Belfast, UK
| | - J R Williams
- ADAS Boxworth, Battlegate Road, Boxworth, Cambridge CB23 4NN, UK
| | - K A Smith
- School of Geosciences, University of Edinburgh, Crew Building, Alexander Crum Brown Road, Edinburgh EH9 3FF, and Weston Road, Totnes TQ9 5AH, Devon, UK
| | - S Calvet
- Universitat Politècnica de València, Institute of Animal Science and Technology, Camino de Vera s.n., 46022, Valencia, Spain
| |
Collapse
|
6
|
Chadwick DR, Cardenas LM, Dhanoa MS, Donovan N, Misselbrook T, Williams JR, Thorman RE, McGeough KL, Watson CJ, Bell M, Anthony SG, Rees RM. The contribution of cattle urine and dung to nitrous oxide emissions: Quantification of country specific emission factors and implications for national inventories. Sci Total Environ 2018; 635:607-617. [PMID: 29679833 PMCID: PMC6024564 DOI: 10.1016/j.scitotenv.2018.04.152] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [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: 03/12/2018] [Revised: 04/10/2018] [Accepted: 04/10/2018] [Indexed: 05/27/2023]
Abstract
Urine patches and dung pats from grazing livestock create hotspots for production and emission of the greenhouse gas, nitrous oxide (N2O), and represent a large proportion of total N2O emissions in many national agricultural greenhouse gas inventories. As such, there is much interest in developing country specific N2O emission factors (EFs) for excretal nitrogen (EF3, pasture, range and paddock) deposited during gazing. The aims of this study were to generate separate N2O emissions data for cattle derived urine and dung, to provide an evidence base for the generation of a country specific EF for the UK from this nitrogen source. The experiments were also designed to determine the effects of site and timing of application on emissions, and the efficacy of the nitrification inhibitor, dicyandiamide (DCD) on N2O losses. This co-ordinated set of 15 plot-scale, year-long field experiments using static chambers was conducted at five grassland sites, typical of the soil and climatic zones of grazed grassland in the UK. We show that the average urine and dung N2O EFs were 0.69% and 0.19%, respectively, resulting in a combined excretal N2O EF (EF3), of 0.49%, which is <25% of the IPCC default EF3 for excretal returns from grazing cattle. Regression analysis suggests that urine N2O EFs were controlled more by composition than was the case for dung, whilst dung N2O EFs were more related to soil and environmental factors. The urine N2O EF was significantly greater from the site in SW England, and significantly greater from the early grazing season urine application than later applications. Dycandiamide reduced the N2O EF from urine patches by an average of 46%. The significantly lower excretal EF3 than the IPCC default has implications for the UK's national inventory and for subsequent carbon footprinting of UK ruminant livestock products.
Collapse
Affiliation(s)
- D R Chadwick
- School of Environment, Natural Resources and Geography, Bangor University, Bangor LL57 2UW, UK.
| | - L M Cardenas
- Rothamsted Research, North Wyke, Devon EX20 2SB, UK
| | - M S Dhanoa
- Rothamsted Research, North Wyke, Devon EX20 2SB, UK
| | - N Donovan
- Rothamsted Research, North Wyke, Devon EX20 2SB, UK
| | | | - J R Williams
- ADAS Boxworth, Battlegate Rd., Cambridge CB23 4NN, UK
| | - R E Thorman
- ADAS Boxworth, Battlegate Rd., Cambridge CB23 4NN, UK
| | - K L McGeough
- Agri-Food and Biosciences Institute, 18a, Newforge Lane, BT9 5PX, Belfast, UK
| | - C J Watson
- Agri-Food and Biosciences Institute, 18a, Newforge Lane, BT9 5PX, Belfast, UK
| | - M Bell
- Scotland's Rural College (SRUC), West Mains Road, Edinburgh EH9 3JG, UK
| | - S G Anthony
- ADAS Wolverhampton, Titan 1 offices, Coxwell Avenue, Wolverhampton Science Park, Wolverhampton WV10 9RT, UK
| | - R M Rees
- Scotland's Rural College (SRUC), West Mains Road, Edinburgh EH9 3JG, UK
| |
Collapse
|
7
|
Snyder RA, Trimble CJ, Rong CC, Folkes PA, Taylor PJ, Williams JR. Weak-link Josephson Junctions Made from Topological Crystalline Insulators. Phys Rev Lett 2018; 121:097701. [PMID: 30230891 DOI: 10.1103/physrevlett.121.097701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Indexed: 06/08/2023]
Abstract
We report on the fabrication of Josephson junctions using the topological crystalline insulator Pb_{0.5}Sn_{0.5}Te as the weak link. The properties of these junctions are characterized and compared to those fabricated with weak links of PbTe, a similar material yet topologically trivial. Most striking is the difference in the ac Josephson effect: junctions made with Pb_{0.5}Sn_{0.5}Te exhibit a rich subharmonic structure consistent with a skewed current-phase relation. This structure is absent in junctions fabricated from PbTe. A discussion is given on the origin of this effect as an indication of novel behavior arising from the topologically nontrivial surface state.
Collapse
Affiliation(s)
- R A Snyder
- Department of Physics, Joint Quantum Institute and the Center for Nanophysics and Advanced Materials, University of Maryland, College Park, Maryland 20742, USA
| | - C J Trimble
- Department of Physics, Joint Quantum Institute and the Center for Nanophysics and Advanced Materials, University of Maryland, College Park, Maryland 20742, USA
| | - C C Rong
- Army Research Laboratory, Adelphi, Maryland 20783, USA
| | - P A Folkes
- Army Research Laboratory, Adelphi, Maryland 20783, USA
| | - P J Taylor
- Army Research Laboratory, Adelphi, Maryland 20783, USA
| | - J R Williams
- Department of Physics, Joint Quantum Institute and the Center for Nanophysics and Advanced Materials, University of Maryland, College Park, Maryland 20742, USA
| |
Collapse
|
8
|
Williams JR, Roseland JM, Nguyen QV, Howe JC, Patterson KY, Pehrsson PR, Thompson LD. Nutrient composition and retention in whole turkeys with and without added solution. Poult Sci 2017; 96:3586-3592. [PMID: 28938764 DOI: 10.3382/ps/pex165] [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: 08/22/2016] [Accepted: 05/11/2017] [Indexed: 11/20/2022] Open
Abstract
Whole turkeys sold in retail outlets are typically processed with added solutions to improve their taste and tenderness. The purpose of this study was to evaluate the nutrient composition of whole turkeys with and without added solution, and to update the nutrient profile of turkey for the USDA National Nutrient Database for Standard Reference. Eleven pairs of turkeys with added solution were obtained from statistically representative retail outlets using a nationwide sampling plan developed for USDA's National Food and Nutrient Analysis Program; 4 pairs of turkeys without added solution were purchased from local food outlets. Turkeys were roasted to an internal temperature of 165°F (74°C). Values of selected nutrients in light and dark meat, including skin, were determined by USDA approved laboratories using quality assurance protocols. Both raw and cooked turkeys, with and without added solution, were compared by one-way and 2-way factorial ANOVA. The results showed a significant interaction for fat (P < 0.0001) and zinc (P = 0.0070) between turkeys that were raw and cooked and those prepared with or without added solution. Fat was higher in raw turkeys with added solution compared to without added solution. Similarly, sodium, phosphorus, and calcium values were significantly higher in turkeys with added solution (P < 0.05) than in turkeys without added solution. Data from this study will be useful for developing strategies to address sodium-related health issues, nutrition monitoring, consumption surveys, and policy development.
Collapse
Affiliation(s)
- J R Williams
- US Department of Agriculture, Nutrient Data Laboratory, 10300 Baltimore Avenue, Building 005, Beltsville, MD 20705
| | - J M Roseland
- US Department of Agriculture, Nutrient Data Laboratory, 10300 Baltimore Avenue, Building 005, Beltsville, MD 20705
| | - Q V Nguyen
- US Department of Agriculture, Nutrient Data Laboratory, 10300 Baltimore Avenue, Building 005, Beltsville, MD 20705
| | - J C Howe
- 7800 LaSalle Court, Severn, MD 21144
| | - K Y Patterson
- US Department of Agriculture, Nutrient Data Laboratory, 10300 Baltimore Avenue, Building 005, Beltsville, MD 20705
| | - P R Pehrsson
- US Department of Agriculture, Nutrient Data Laboratory, 10300 Baltimore Avenue, Building 005, Beltsville, MD 20705
| | - L D Thompson
- Department of Animal and Food Sciences, Texas Tech University, Box 42141, Lubbock, TX 79409
| |
Collapse
|
9
|
Ribeiro TR, Costa FWG, Soares ECS, Williams JR, Fonteles CSR. Enamel and dentin mineralization in familial hypophosphatemic rickets: a micro-CT study. Dentomaxillofac Radiol 2015; 44:20140347. [PMID: 25651274 DOI: 10.1259/dmfr.20140347] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
OBJECTIVES The aim of the present study was to analyse the mineralization pattern of enamel and dentin in patients affected by X-linked hypophosphatemic rickets (XLHR) using micro-CT (µCT), and to associate enamel and dentin mineralization in primary and permanent teeth with tooth position, gender and the presence/absence of this disease. METHODS 19 teeth were collected from 5 individuals from the same family, 1 non-affected by XLHR and 4 affected by XLHR. Gender, age, tooth position (anterior/posterior) and tooth type (deciduous/permanent) were recorded for each patient. Following collection, teeth were placed in 0.1% thymol solution until µCT scan. Projection images were reconstructed and analysed. A plot profile describing the greyscale distance relationship in µCT images was achieved through a line bisecting each tooth in a region with the presence of enamel and dentin. The enamel and dentin mineralization densities were measured and compared. Univariate ANOVA and post hoc Tukey tests were used for all comparisons. RESULTS Teeth of all affected patients presented dentin with a different mineralization pattern compared with the teeth of healthy patients with dentin defects observed next to the pulp chambers. Highly significant differences were found for gray values between anterior and posterior teeth (p < 0.05), affected and non-affected (p < 0.05), as well as when position and disease status were considered (p < 0.05). CONCLUSIONS In conclusion, the mineralization patterns of dentin differed when comparing teeth from patients with and without FHR, mainly next to pulp chambers where areas with porosity and consequently lower mineral density and dentin defects were found.
Collapse
Affiliation(s)
- T R Ribeiro
- 1 Clinical Dentistry Department, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | | | | | | | | |
Collapse
|
10
|
Santhi C, Arnold JG, White M, Di Luzio M, Kannan N, Norfleet L, Atwood J, Kellogg R, Wang X, Williams JR, Gerik T. Effects of agricultural conservation practices on N loads in the Mississippi-atchafalaya river basin. J Environ Qual 2014; 43:1903-1915. [PMID: 25602207 DOI: 10.2134/jeq2013.10.0403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A modeling framework consisting of a farm-scale model, Agricultural Policy Environmental Extender (APEX); a watershed-scale model, Soil and Water Assessment Tool (SWAT); and databases was used in the Conservation Effects Assessment Project to quantify the environmental benefits of conservation practices on cropland. APEX is used to simulate conservation practices on cultivated cropland and Conservation Reserve Program land to assess the edge-of-field water-quality benefits. Flow and pollutant loadings from APEX are input to SWAT. SWAT simulates the remaining noncultivated land and routes flow and loads generated from noncultivated land, point sources, and cropland to the basin outlet. SWAT is used for assessing the effects of practices on local and in-stream water-quality benefits. Each river basin is calibrated and validated for streamflow and loads at multiple gauging stations. The objectives of the current study are to estimate the effects of currently existing and additional conservation practices on total N (TN) loads in the Mississippi-Atchafalaya River Basin (MARB) and draw insights on TN load reductions necessary for reducing the hypoxic zone in the Gulf of Mexico. The effects of conservation practice scenarios on local and in-stream (riverine) water quality are evaluated. Model results indicate that conservation practices currently on cropland have reduced the TN losses to local waters between 20 and 59% in the six river basins within MARB and the TN load discharged to the Gulf by 17%. Further water-quality improvement can be obtained in the MARB with additional conservation treatment.
Collapse
|
11
|
Falk K, McCoy CA, Fryer CL, Greeff CW, Hungerford AL, Montgomery DS, Schmidt DW, Sheppard DG, Williams JR, Boehly TR, Benage JF. Temperature measurements of shocked silica aerogel foam. Phys Rev E Stat Nonlin Soft Matter Phys 2014; 90:033107. [PMID: 25314547 DOI: 10.1103/physreve.90.033107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Indexed: 06/04/2023]
Abstract
We present recent results of equation-of-state (EOS) measurements of shocked silica (SiO_{2}) aerogel foam at the OMEGA laser facility. Silica aerogel is an important low-density pressure standard used in many high energy density experiments, including the novel technique of shock and release. Due to its many applications, it has been a heavily studied material and has a well-known Hugoniot curve. This work then complements the velocity and pressure measurements with additional temperature data providing the full EOS information within the warm dense matter regime for the temperature interval of 1-15 eV and shock velocities between 10 and 40 km/s corresponding to shock pressures of 0.3-2 Mbar. The experimental results were compared with hydrodynamic simulations and EOS models. We found that the measured temperature was systematically lower than suggested by theoretical calculations. Simulations provide a possible explanation that the emission measured by optical pyrometry comes from a radiative precursor rather than from the shock front, which could have important implications for such measurements.
Collapse
Affiliation(s)
- K Falk
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - C A McCoy
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - C L Fryer
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - C W Greeff
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A L Hungerford
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - D S Montgomery
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - D W Schmidt
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - D G Sheppard
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J R Williams
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - T R Boehly
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - J F Benage
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA and Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| |
Collapse
|
12
|
Amet F, Williams JR, Watanabe K, Taniguchi T, Goldhaber-Gordon D. Selective equilibration of spin-polarized quantum Hall edge states in graphene. Phys Rev Lett 2014; 112:196601. [PMID: 24877955 DOI: 10.1103/physrevlett.112.196601] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Indexed: 06/03/2023]
Abstract
We report on transport measurements of dual-gated, single-layer graphene devices in the quantum Hall regime, allowing for independent control of the filling factors in adjoining regions. Progress in device quality allows us to study scattering between edge states when the fourfold degeneracy of the Landau level is lifted by electron correlations, causing edge states to be spin and/or valley polarized. In this new regime, we observe a dramatic departure from the equilibration seen in more disordered devices: edge states with opposite spins propagate without mixing. As a result, the degree of equilibration inferred from transport can reveal the spin polarization of the ground state at each filling factor. In particular, the first Landau level is shown to be spin polarized at half filling, providing an independent confirmation of a conclusion of Young et al. [Nat. Phys. 8, 550 (2012). The conductance in the bipolar regime is strongly suppressed, indicating that copropagating edge states, even with the same spin, do not equilibrate along PN interfaces. We attribute this behavior to the formation of an insulating ν = 0 stripe at the PN interface.
Collapse
Affiliation(s)
- F Amet
- Department of Applied Physics, Stanford University, Stanford, California 94305, USA
| | - J R Williams
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - K Watanabe
- Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - T Taniguchi
- Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - D Goldhaber-Gordon
- Department of Physics, Stanford University, Stanford, California 94305, USA
| |
Collapse
|
13
|
Mitchell KM, Foss AM, Prudden HJ, Mukandavire Z, Pickles M, Williams JR, Johnson HC, Ramesh BM, Washington R, Isac S, Rajaram S, Phillips AE, Bradley J, Alary M, Moses S, Lowndes CM, Watts CH, Boily MC, Vickerman P. Who mixes with whom among men who have sex with men? Implications for modelling the HIV epidemic in southern India. J Theor Biol 2014; 355:140-50. [PMID: 24727187 PMCID: PMC4064301 DOI: 10.1016/j.jtbi.2014.04.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [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: 01/04/2013] [Revised: 04/01/2014] [Accepted: 04/02/2014] [Indexed: 11/19/2022]
Abstract
In India, the identity of men who have sex with men (MSM) is closely related to the role taken in anal sex (insertive, receptive or both), but little is known about sexual mixing between identity groups. Both role segregation (taking only the insertive or receptive role) and the extent of assortative (within-group) mixing are known to affect HIV epidemic size in other settings and populations. This study explores how different possible mixing scenarios, consistent with behavioural data collected in Bangalore, south India, affect both the HIV epidemic, and the impact of a targeted intervention. Deterministic models describing HIV transmission between three MSM identity groups (mostly insertive Panthis/Bisexuals, mostly receptive Kothis/Hijras and versatile Double Deckers), were parameterised with behavioural data from Bangalore. We extended previous models of MSM role segregation to allow each of the identity groups to have both insertive and receptive acts, in differing ratios, in line with field data. The models were used to explore four different mixing scenarios ranging from assortative (maximising within-group mixing) to disassortative (minimising within-group mixing). A simple model was used to obtain insights into the relationship between the degree of within-group mixing, R0 and equilibrium HIV prevalence under different mixing scenarios. A more complex, extended version of the model was used to compare the predicted HIV prevalence trends and impact of an HIV intervention when fitted to data from Bangalore. With the simple model, mixing scenarios with increased amounts of assortative (within-group) mixing tended to give rise to a higher R0 and increased the likelihood that an epidemic would occur. When the complex model was fit to HIV prevalence data, large differences in the level of assortative mixing were seen between the fits identified using different mixing scenarios, but little difference was projected in future HIV prevalence trends. An oral pre-exposure prophylaxis (PrEP) intervention was modelled, targeted at the different identity groups. For intervention strategies targeting the receptive or receptive and versatile MSM together, the overall impact was very similar for different mixing patterns. However, for PrEP scenarios targeting insertive or versatile MSM alone, the overall impact varied considerably for different mixing scenarios; more impact was achieved with greater levels of disassortative mixing. Different mixing scenarios are explored for 3 groups of role-segregated MSM. Models show that the mixing scenario affects both R0 and endemic HIV prevalence. When models are fit to data, predicted HIV trends are unaffected by mixing. Impact of targeted (but not non-targeted) interventions can be affected by mixing.
Collapse
Affiliation(s)
- K M Mitchell
- London School of Hygiene and Tropical Medicine, London, UK.
| | - A M Foss
- London School of Hygiene and Tropical Medicine, London, UK.
| | - H J Prudden
- London School of Hygiene and Tropical Medicine, London, UK.
| | - Z Mukandavire
- London School of Hygiene and Tropical Medicine, London, UK.
| | - M Pickles
- London School of Hygiene and Tropical Medicine, London, UK; Imperial College London, London, UK.
| | | | - H C Johnson
- London School of Hygiene and Tropical Medicine, London, UK.
| | - B M Ramesh
- Karnataka Health Promotion Trust, Bangalore, India; University of Manitoba, Winnipeg, MB, Canada.
| | - R Washington
- Karnataka Health Promotion Trust, Bangalore, India; St. John's Research Institute, Bangalore, India.
| | - S Isac
- Karnataka Health Promotion Trust, Bangalore, India.
| | - S Rajaram
- CHARME-India Project, Bangalore, India.
| | | | - J Bradley
- CHARME-India Project, Bangalore, India; Centre de recherche du CHU de Québec, Québec, QC, Canada.
| | - M Alary
- Centre de recherche du CHU de Québec, Québec, QC, Canada; Département de medicine sociale et preventive, Université laval, Québec, QC, Canada; Institut national de santé publique du Québec, Québec, QC, Canada.
| | - S Moses
- University of Manitoba, Winnipeg, MB, Canada.
| | - C M Lowndes
- Centre de recherche du CHU de Québec, Québec, QC, Canada; Public Health England, London, UK.
| | - C H Watts
- London School of Hygiene and Tropical Medicine, London, UK.
| | - M-C Boily
- Imperial College London, London, UK.
| | - P Vickerman
- University of Bristol, Bristol, UK; London School of Hygiene and Tropical Medicine, London, UK.
| |
Collapse
|
14
|
Bloom BJ, Nicholson TL, Williams JR, Campbell SL, Bishof M, Zhang X, Zhang W, Bromley SL, Ye J. An optical lattice clock with accuracy and stability at the 10(-18) level. Nature 2014; 506:71-5. [PMID: 24463513 DOI: 10.1038/nature12941] [Citation(s) in RCA: 726] [Impact Index Per Article: 72.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 12/04/2013] [Indexed: 11/09/2022]
Abstract
Progress in atomic, optical and quantum science has led to rapid improvements in atomic clocks. At the same time, atomic clock research has helped to advance the frontiers of science, affecting both fundamental and applied research. The ability to control quantum states of individual atoms and photons is central to quantum information science and precision measurement, and optical clocks based on single ions have achieved the lowest systematic uncertainty of any frequency standard. Although many-atom lattice clocks have shown advantages in measurement precision over trapped-ion clocks, their accuracy has remained 16 times worse. Here we demonstrate a many-atom system that achieves an accuracy of 6.4 × 10(-18), which is not only better than a single-ion-based clock, but also reduces the required measurement time by two orders of magnitude. By systematically evaluating all known sources of uncertainty, including in situ monitoring of the blackbody radiation environment, we improve the accuracy of optical lattice clocks by a factor of 22. This single clock has simultaneously achieved the best known performance in the key characteristics necessary for consideration as a primary standard-stability and accuracy. More stable and accurate atomic clocks will benefit a wide range of fields, such as the realization and distribution of SI units, the search for time variation of fundamental constants, clock-based geodesy and other precision tests of the fundamental laws of nature. This work also connects to the development of quantum sensors and many-body quantum state engineering (such as spin squeezing) to advance measurement precision beyond the standard quantum limit.
Collapse
Affiliation(s)
- B J Bloom
- 1] JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440, USA [2] Department of Physics, University of Colorado, Boulder, Colorado 80309-0390, USA [3]
| | - T L Nicholson
- 1] JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440, USA [2] Department of Physics, University of Colorado, Boulder, Colorado 80309-0390, USA [3]
| | - J R Williams
- 1] JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440, USA [2] Department of Physics, University of Colorado, Boulder, Colorado 80309-0390, USA [3] Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA
| | - S L Campbell
- 1] JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440, USA [2] Department of Physics, University of Colorado, Boulder, Colorado 80309-0390, USA
| | - M Bishof
- 1] JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440, USA [2] Department of Physics, University of Colorado, Boulder, Colorado 80309-0390, USA
| | - X Zhang
- 1] JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440, USA [2] Department of Physics, University of Colorado, Boulder, Colorado 80309-0390, USA
| | - W Zhang
- 1] JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440, USA [2] Department of Physics, University of Colorado, Boulder, Colorado 80309-0390, USA
| | - S L Bromley
- 1] JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440, USA [2] Department of Physics, University of Colorado, Boulder, Colorado 80309-0390, USA
| | - J Ye
- 1] JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440, USA [2] Department of Physics, University of Colorado, Boulder, Colorado 80309-0390, USA
| |
Collapse
|
15
|
Santhi C, Kannan N, White M, Di Luzio M, Arnold JG, Wang X, Williams JR. An integrated modeling approach for estimating the water quality benefits of conservation practices at the river basin scale. J Environ Qual 2014; 43:177-198. [PMID: 25602551 DOI: 10.2134/jeq2011.0460] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The USDA initiated the Conservation Effects Assessment Project (CEAP) to quantify the environmental benefits of conservation practices at regional and national scales. For this assessment, a sampling and modeling approach is used. This paper provides a technical overview of the modeling approach used in CEAP cropland assessment to estimate the off-site water quality benefits of conservation practices using the Ohio River Basin (ORB) as an example. The modeling approach uses a farm-scale model, Agricultural Policy Environmental Extender (APEX), and a watershed scale model (the Soil and Water Assessment Tool [SWAT]) and databases in the Hydrologic Unit Modeling for the United States system. Databases of land use, soils, land use management, topography, weather, point sources, and atmospheric depositions were developed to derive model inputs. APEX simulates the cultivated cropland, Conserve Reserve Program land, and the practices implemented on them, whereas SWAT simulates the noncultivated land (e.g., pasture, range, urban, and forest) and point sources. Simulation results from APEX are input into SWAT. SWAT routes all sources, including APEX's, to the basin outlet through each eight-digit watershed. Each basin is calibrated for stream flow, sediment, and nutrient loads at multiple gaging sites and turned in for simulating the effects of conservation practice scenarios on water quality. Results indicate that sediment, nitrogen, and phosphorus loads delivered to the Mississippi River from ORB could be reduced by 16, 15, and 23%, respectively, due to current conservation practices. Modeling tools are useful to provide science-based information for assessing existing conservation programs, developing future programs, and developing insights on load reductions necessary for hypoxia in the Gulf of Mexico.
Collapse
|
16
|
Amet F, Williams JR, Watanabe K, Taniguchi T, Goldhaber-Gordon D. Insulating behavior at the neutrality point in single-layer graphene. Phys Rev Lett 2013; 110:216601. [PMID: 23745906 DOI: 10.1103/physrevlett.110.216601] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 01/15/2013] [Indexed: 06/02/2023]
Abstract
The fate of the low-temperature conductance at the charge-neutrality (Dirac) point in a single sheet of graphene on boron nitride is investigated down to 20 mK. As the temperature is lowered, the peak resistivity diverges with a power-law behavior and becomes as high as several megohms per square at the lowest temperature, in contrast with the commonly observed saturation of the conductivity. As a perpendicular magnetic field is applied, our device remains insulating and directly transitions to the broken-valley-symmetry, ν=0 quantum Hall state, indicating that the insulating behavior we observe at zero magnetic field is a result of broken valley symmetry. Finally we discuss the possible origins of this effect.
Collapse
Affiliation(s)
- F Amet
- Department of Applied Physics, Stanford University, Stanford, California 94305, USA
| | | | | | | | | |
Collapse
|
17
|
Nicholson TL, Martin MJ, Williams JR, Bloom BJ, Bishof M, Swallows MD, Campbell SL, Ye J. Comparison of two independent Sr optical clocks with 1×10(-17) stability at 10(3) s. Phys Rev Lett 2012; 109:230801. [PMID: 23368177 DOI: 10.1103/physrevlett.109.230801] [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] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Indexed: 06/01/2023]
Abstract
Many-particle optical lattice clocks have the potential for unprecedented measurement precision and stability due to their low quantum projection noise. However, this potential has so far never been realized because clock stability has been limited by frequency noise of optical local oscillators. By synchronously probing two ^{87}Sr lattice systems using a laser with a thermal noise floor of 1×10(-15), we remove classically correlated laser noise from the intercomparison, but this does not demonstrate independent clock performance. With an improved optical oscillator that has a 1×10(-16) thermal noise floor, we demonstrate an order of magnitude improvement over the best reported stability of any independent clock, achieving a fractional instability of 1×10(-17) in 1000 s of averaging time for synchronous or asynchronous comparisons. This result is within a factor of 2 of the combined quantum projection noise limit for a 160 ms probe time with ~10(3) atoms in each clock. We further demonstrate that even at this high precision, the overall systematic uncertainty of our clock is not limited by atomic interactions. For the second Sr clock, which has a cavity-enhanced lattice, the atomic-density-dependent frequency shift is evaluated to be -3.11×10(-17) with an uncertainty of 8.2×10(-19).
Collapse
Affiliation(s)
- T L Nicholson
- JILA, National Institute of Standards and Technology and University of Colorado, Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Martin CJ, Sutton DG, Magee J, McVey S, Williams JR, Peet D. Derivation of factors for estimating the scatter of diagnostic x-rays from walls and ceiling slabs. J Radiol Prot 2012; 32:373-396. [PMID: 23006642 DOI: 10.1088/0952-4746/32/4/373] [Citation(s) in RCA: 4] [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] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Computed tomography (CT) scanning rooms and interventional x-ray facilities with heavy workloads may require the installation of shielding to protect against radiation scattered from walls or ceiling slabs. This is particularly important for the protection of those operating x-ray equipment from within control cubicles who may be exposed to radiation scattered from the ceiling over the top of the protective barrier and round the side if a cubicle door is not included. Data available on the magnitude of this tertiary scatter from concrete slabs are limited. Moreover, there is no way in which tertiary scatter levels can be estimated easily for specific facilities. There is a need for a suitable method for quantification of tertiary scatter because of the increases in workloads of complex x-ray facilities. In this study diagnostic x-ray air kerma levels scattered from concrete and brick walls have been measured to verify scatter factors. The results have been used in a simulation of tertiary scatter for x-ray facilities involving summation of scatter contributions from elements across concrete ceiling slabs. The majority of the ceiling scatter air kerma to which staff behind a barrier will be exposed arises from the area between the patient/x-ray tube and the staff. The level depends primarily on the heights of the ceiling and protective barrier. A method has been developed to allow tertiary scatter levels to be calculated using a simple equation based on a standard arrangement for rooms with different ceiling and barrier heights. Coefficients have been derived for a CT facility and an interventional suite to predict tertiary scatter levels from the workload, so that consideration can be given to the protection options available.
Collapse
Affiliation(s)
- C J Martin
- Health Physics, Gartnavel Royal Hospital, 1055 Great Western Road, Glasgow G12 0XH, UK
| | | | | | | | | | | |
Collapse
|
19
|
Williams JR, Bestwick AJ, Gallagher P, Hong SS, Cui Y, Bleich AS, Analytis JG, Fisher IR, Goldhaber-Gordon D. Unconventional Josephson effect in hybrid superconductor-topological insulator devices. Phys Rev Lett 2012; 109:056803. [PMID: 23006196 DOI: 10.1103/physrevlett.109.056803] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Indexed: 06/01/2023]
Abstract
We report on transport properties of Josephson junctions in hybrid superconducting-topological insulator devices, which show two striking departures from the common Josephson junction behavior: a characteristic energy that scales inversely with the width of the junction, and a low characteristic magnetic field for suppressing supercurrent. To explain these effects, we propose a phenomenological model which expands on the existing theory for topological insulator Josephson junctions.
Collapse
Affiliation(s)
- J R Williams
- Department of Physics, Stanford University, California 94305, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Sutton DG, Martin CJ, Peet D, Williams JR. The characterization and transmission of scattered radiation resulting from x-ray beams filtered with zero to 0.99 mm copper. J Radiol Prot 2012; 32:117-129. [PMID: 22555158 DOI: 10.1088/0952-4746/32/2/117] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The specification of shielding for fluoroscopic facilities in the UK is based on the determination of scatter incident on a barrier using a simple formula linking kerma area product and scatter kerma. Over the last few years there has been a move to incorporate additional copper filtration in equipment used for high dose fluoroscopic and interventional examinations, and the existing formula does not take this into account. The spectral and transmission characteristics of the scattered radiation resulting from a primary x-ray beam filtered with additional copper are not known. In this study, the relationship between primary and scattered radiation in these beams has been investigated as have their transmission characteristics. The scatter kerma area product from filtered beams is shown to be greater than that from conventional x-rays and a simple numerical correction linking the two has been derived. The implications for shielding calculations have been assessed and the impact of the correction on calculated barrier thickness has been shown to be relatively small. The broad beam transmission characteristics of the radiation scattered from the filtered beams have been simulated using Monte Carlo methods and found to be adequately described by the standard transmission equation using conventional coefficients.
Collapse
Affiliation(s)
- D G Sutton
- Medical Physics, Ninewells Hospital and Medical School, Dundee, DD1 9SY, UK.
| | | | | | | |
Collapse
|
21
|
Williams JR, Hirsch ES, Anderson K, Bush AL, Goldstein SR, Grill S, Lehmann S, Little JT, Margolis RL, Palanci J, Pontone G, Weiss H, Rabins P, Marsh L. A comparison of nine scales to detect depression in Parkinson disease: which scale to use? Neurology 2012; 78:998-1006. [PMID: 22422897 DOI: 10.1212/wnl.0b013e31824d587f] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE The Methods of Optimal Depression Detection in Parkinson's Disease (MOOD-PD) study compared the psychometric properties of 9 depression scales to provide guidance on scale selection in Parkinson disease (PD). METHODS Patients with PD (n = 229) from community-based neurology practices completed 6 self-report scales (Beck Depression Inventory [BDI]-II, Center for Epidemiologic Studies Depression Rating Scale-Revised [CESD-R], 30-item Geriatric Depression Scale [GDS-30], Inventory of Depressive Symptoms-Patient [IDS-SR], Patient Health Questionnaire-9 [PHQ-9], and Unified Parkinson's Disease Rating Scale [UPDRS]-Part I) and were administered 3 clinician-rated scales (17-item Hamilton Depression Rating Scale [HAM-D-17], Inventory of Depressive Symptoms-Clinician [IDS-C], and Montgomery-Åsberg Depression Rating Scale [MADRS] and a psychiatric interview. DSM-IV-TR diagnoses were established by an expert panel blinded to the self-reported rating scale data. Receiver operating characteristic curves were used to estimate the area under the curve (AUC) of each scale. RESULTS All scales performed better than chance (AUC 0.75-0.85). Sensitivity ranged from 0.66 to 0.85 and specificity ranged from 0.60 to 0.88. The UPDRS Depression item had a smaller AUC than the BDI-II, HAM-D-17, IDS-C, and MADRS. The CESD-R also had a smaller AUC than the MADRS. The remaining AUCs were statistically similar. CONCLUSIONS The GDS-30 may be the most efficient depression screening scale to use in PD because of its brevity, favorable psychometric properties, and lack of copyright protection. However, all scales studied, except for the UPDRS Depression, are valid screening tools when PD-specific cutoff scores are used.
Collapse
Affiliation(s)
- J R Williams
- Food and Drug Administration, Silver Spring, MD, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Wallace H, Martin CJ, Sutton DG, Peet D, Williams JR. Establishment of scatter factors for use in shielding calculations and risk assessment for computed tomography facilities. J Radiol Prot 2012; 32:39-50. [PMID: 22327169 DOI: 10.1088/0952-4746/32/1/39] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The specification of shielding for CT facilities in the UK and many other countries has been based on isodose scatter curves supplied by the manufacturers combined with the scanner's mAs workload. Shielding calculations for radiography and fluoroscopy are linked to a dose measurement of radiation incident on the patient called the kerma-area product (KAP), and a related quantity, the dose-length product (DLP), is now employed for assessment of CT patient doses. In this study the link between scatter air kerma and DLP has been investigated for CT scanners from different manufacturers. Scatter air kerma values have been measured and scatter factors established that can be used to estimate air kerma levels within CT scanning rooms. Factors recommended to derive the scatter air kerma at 1 m from the isocentre are 0.36 µGy (mGy cm)(-1) for the body and 0.14 µGy (mGy cm)(-1) for head scans. The CT scanner gantries only transmit 10% of the scatter air kerma level and this can also be taken into account when designing protection. The factors can be used to predict scatter air kerma levels within a scanner room that might be used in risk assessments relating to personnel whose presence may be required during CT fluoroscopy procedures.
Collapse
Affiliation(s)
- H Wallace
- Health Physics, Gartnavel Royal Hospital, 1055 Great Western Road, Glasgow, G12 0XH, UK
| | | | | | | | | |
Collapse
|
23
|
Lee M, Williams JR, Zhang S, Frisbie CD, Goldhaber-Gordon D. Electrolyte gate-controlled Kondo effect in SrTiO3. Phys Rev Lett 2011; 107:256601. [PMID: 22243097 DOI: 10.1103/physrevlett.107.256601] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Indexed: 05/31/2023]
Abstract
We report low-temperature, high-field magnetotransport measurements of SrTiO(3) gated by an ionic gel electrolyte. A saturating resistance upturn and negative magnetoresistance that signal the emergence of the Kondo effect appear for higher applied gate voltages. This observation, enabled by the wide tunability of the ionic gel-applied electric field, promotes the interpretation of the electric field-effect-induced 2D electron system in SrTiO(3) as an admixture of magnetic Ti(3+) ions, i.e., localized and unpaired electrons, and delocalized electrons that partially fill the Ti 3d conduction band.
Collapse
Affiliation(s)
- Menyoung Lee
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | | | | | | | | |
Collapse
|
24
|
Blatt S, Nicholson TL, Bloom BJ, Williams JR, Thomsen JW, Julienne PS, Ye J. Measurement of optical Feshbach resonances in an ideal gas. Phys Rev Lett 2011; 107:073202. [PMID: 21902391 DOI: 10.1103/physrevlett.107.073202] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Indexed: 05/31/2023]
Abstract
Using a narrow intercombination line in alkaline earth atoms to mitigate large inelastic losses, we explore the optical Feshbach resonance effect in an ultracold gas of bosonic (88)Sr. A systematic measurement of three resonances allows precise determinations of the optical Feshbach resonance strength and scaling law, in agreement with coupled-channel theory. Resonant enhancement of the complex scattering length leads to thermalization mediated by elastic and inelastic collisions in an otherwise ideal gas. Optical Feshbach resonance could be used to control atomic interactions with high spatial and temporal resolution.
Collapse
Affiliation(s)
- S Blatt
- JILA and Department of Physics, NIST and University of Colorado, Boulder, 80309-0440, USA
| | | | | | | | | | | | | |
Collapse
|
25
|
Abstract
We investigate transport in locally gated graphene devices, where carriers are injected and collected along, rather than across, the gate edge. Tuning densities into the p-n regime significantly reduces resistance along the p-n interface, while resistance across the interface increases. This provides an experimental signature of snake states, which zigzag along the p-n interface and remain stable as applied perpendicular magnetic field approaches zero. Snake states appear as a peak in transverse resistance measured along the p-n interface. The generic role of snake states in disordered graphene is also discussed.
Collapse
Affiliation(s)
- J R Williams
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | | |
Collapse
|
26
|
Nakaharai S, Williams JR, Marcus CM. Gate-defined graphene quantum point contact in the quantum Hall regime. Phys Rev Lett 2011; 107:036602. [PMID: 21838385 DOI: 10.1103/physrevlett.107.036602] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Indexed: 05/31/2023]
Abstract
We investigate transport in a gate-defined graphene quantum point contact in the quantum Hall regime. Edge states confined to the interface of p and n regions in the graphene sheet are controllably brought together from opposite sides of the sample and allowed to mix in this split-gate geometry. Among the expected quantum Hall features, an unexpected additional plateau at 0.5h/e2 is observed. We propose that chaotic mixing of edge channels gives rise to the extra plateau.
Collapse
Affiliation(s)
- S Nakaharai
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | | | | |
Collapse
|
27
|
Williams JR, Low T, Lundstrom MS, Marcus CM. Gate-controlled guiding of electrons in graphene. Nat Nanotechnol 2011; 6:222-225. [PMID: 21317890 DOI: 10.1038/nnano.2011.3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 01/06/2011] [Indexed: 05/30/2023]
Abstract
Ballistic semiconductor structures have allowed the realization of optics-like phenomena in electronic systems, including the magnetic focusing and electrostatic lensing of electrons. An extension that appears unique to graphene is to use both n and p carrier types to create electronic analogues of optical devices with both positive and negative indices of refraction. Here, we use the gate-controlled density of both p and n carrier types in graphene to demonstrate the electronic analogue of fibre-optic guiding. Two basic effects are investigated: bipolar p-n junction guiding, based on the principle of angle-selective transmission through the interface between the graphene and the p-n junction; and unipolar fibre-optic guiding, using total internal reflection controlled by carrier density. We also demonstrate modulation of the guiding efficiency through gating, and comparison of these data with numerical simulations indicates that guiding performance is limited by the roughness of the interface. The development of p-n and fibre-optic guiding in graphene may lead to electrically reconfigurable wiring in high-mobility devices.
Collapse
Affiliation(s)
- J R Williams
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | | | | | | |
Collapse
|
28
|
Abstract
We report nanoscale patterning of graphene using a helium ion microscope configured for lithography. Helium ion lithography is a direct-write lithography process, comparable to conventional focused ion beam patterning, with no resist or other material contacting the sample surface. In the present application, graphene samples on Si/SiO2 substrates are cut using helium ions, with computer controlled alignment, patterning, and exposure. Once suitable beam doses are determined, sharp edge profiles and clean etching are obtained, with little evident damage or doping to the sample. This technique provides fast lithography compatible with graphene, with approximately 15 nm feature sizes.
Collapse
Affiliation(s)
- D C Bell
- School of Engineering and Applied Sciences, Center for Nanoscale Systems, Harvard University, Cambridge, MA 02138, USA
| | | | | | | | | |
Collapse
|
29
|
Williams JR, Hazlett EL, Huckans JH, Stites RW, Zhang Y, O'Hara KM. Evidence for an excited-state Efimov trimer in a three-component Fermi gas. Phys Rev Lett 2009; 103:130404. [PMID: 19905496 DOI: 10.1103/physrevlett.103.130404] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Indexed: 05/28/2023]
Abstract
We observe enhanced three-body recombination in a three-component ;{6}Li Fermi gas attributable to an excited Efimov trimer state intersecting the three-atom scattering threshold near 895 G. From measurements of the recombination rate we determine the Efimov parameters kappa_{*} and eta_{*} for the universal region above 600 G which includes three overlapping Feshbach resonances. The value of kappa_{*} also predicts the locations of loss features previously observed near 130 and 500 G [T. B. Ottenstein, Phys. Rev. Lett. 101, 203202 (2008)10.1103/PhysRevLett.101.203202; J. H. Huckans, Phys. Rev. Lett. 102, 165302 (2009)10.1103/PhysRevLett.102.165302] suggesting they are associated with a ground-state Efimov trimer near threshold. We also report on the realization of a degenerate three-component Fermi gas with approximate SU(3) symmetry.
Collapse
Affiliation(s)
- J R Williams
- Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802-6300, USA
| | | | | | | | | | | |
Collapse
|
30
|
Huckans JH, Williams JR, Hazlett EL, Stites RW, O'Hara KM. Three-body recombination in a three-state Fermi gas with widely tunable interactions. Phys Rev Lett 2009; 102:165302. [PMID: 19518723 DOI: 10.1103/physrevlett.102.165302] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2008] [Revised: 03/17/2009] [Indexed: 05/27/2023]
Abstract
We investigate the stability of a three spin state mixture of ultracold fermionic 6Li atoms over a range of magnetic fields encompassing three Feshbach resonances. For most field values, we attribute decay of the atomic population to three-body processes involving one atom from each spin state and find that the three-body loss coefficient varies by over 4 orders of magnitude. We observe high stability when at least two of the three scattering lengths are small, rapid loss near the Feshbach resonances, and two unexpected resonant loss features. At our highest fields, where all pairwise scattering lengths are approaching a_{t}=-2140a_{0}, we measure a three-body loss coefficient L_{3} approximately 5x10;{-22} cm;{6}/s and a trend toward lower decay rates for higher fields indicating that future studies of color superfluidity and trion formation in a SU(3) symmetric Fermi gas may be feasible.
Collapse
Affiliation(s)
- J H Huckans
- Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802-6300, USA
| | | | | | | | | |
Collapse
|
31
|
Smee RI, Williams JR, Bridger GP. The management dilemmas of invasive subglottic carcinoma. Clin Oncol (R Coll Radiol) 2008; 20:751-6. [PMID: 18849154 DOI: 10.1016/j.clon.2008.08.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Revised: 08/18/2008] [Accepted: 08/19/2008] [Indexed: 10/21/2022]
Abstract
AIMS To evaluate a single centre's experience with subglottic laryngeal carcinoma. MATERIALS AND METHODS The laryngeal cancer database at the Prince of Wales Hospital was sourced to define a sub-population of patients presenting with primary subglottic carcinoma. Excluded from the analysis were patients having a glottic origin for their carcinoma and secondarily involving the subglottis. RESULTS Of 969 patients with newly diagnosed laryngeal cancer, 10 (1%) had subglottic origin. T stage was six T2 and four T3, all were N0. A total laryngectomy was carried out in five patients, four of whom had postoperative radiotherapy, a hemilaryngectomy in one patient and definitive radiotherapy in four patients. There was only one local failure, who could not be salvaged, and one patient died locally controlled with metastatic disease. Thus, local control was achieved in nine of 10 patients. CONCLUSION Although an infrequent sub-population, subglottic carcinoma has a high likelihood of being locally controlled.
Collapse
Affiliation(s)
- R I Smee
- Department of Radiation Oncology, The Prince of Wales Cancer Centre, Randwick, New South Wales, Australia.
| | | | | |
Collapse
|
32
|
Natarajan RN, Williams JR, Lavender SA, An HS, Anderson GB. Relationship between disc injury and manual lifting: a poroelastic finite element model study. Proc Inst Mech Eng H 2008; 222:195-207. [PMID: 18441755 DOI: 10.1243/09544119jeim260] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Understanding how failure originates in a lumbar motion segment subjected to loading conditions that are representative of manual lifting is important because it will pave the way for a better formulation of the exposure-injury relationship. The aim of the current investigation was to use a poroelastic finite element model of a human lumbar disc to determine its biomechanical characteristics under loading conditions that corresponded to three different, commonly occurring lifting activities and to identify the most hazardous type of loading with regard to damage to the disc. The current study showed that asymmetric lifting may increase the risk of back injury and pain. Lifting that involved lateral bending (asymmetric lifting) of the trunk was found to produce stresses at a localized area in the annulus, annuluar fibres, end plates, and facet joints that were higher than their respective tissue failure strength. Thus asymmetric lifting, if performed over a large number of cycles, might help to propagate this localized failure of the disc tissue to a larger area, owing to fatigue. The analyses also showed that largest fluid exchange between the nucleus and the end plates occurred during asymmetric lifting. If the fluid exchange is restricted owing to end plate calcification or sclerosis of the subchondral bone, high intradiscal pressure might develop, leading to higher disc bulge causing back pain.
Collapse
Affiliation(s)
- R N Natarajan
- Department of Orthopedic Surgery, Rush University Medical Center, Armour Academic Facility, Chicago, IL 60612-3833, USA.
| | | | | | | | | |
Collapse
|
33
|
Abstract
We report measurements of current noise in single-layer and multilayer graphene devices. In four single-layer devices, including a p-n junction, the Fano factor remains constant to within +/-10% upon varying carrier type and density, and averages between 0.35 and 0.38. The Fano factor in a multilayer device is found to decrease from a maximal value of 0.33 at the charge-neutrality point to 0.25 at high carrier density. These results are compared to theories for shot noise in ballistic and disordered graphene.
Collapse
Affiliation(s)
- L Dicarlo
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | | | | | | | | |
Collapse
|
34
|
Abstract
Medulloblastomas - primitive neuroectodermal tumours are rare in adults. This review will evaluate a single centre's experience with this malignancy. The medulloblastoma - primitive neuroectodermal tumour database was evaluated for all patients aged more than 18 years who were referred for management. Relevant information from the database was abstracted to provide a descriptive record of this malignancy. Between 1977-2004 there were 11 patients referred, 1 with persistent disease and 10 were eligible, presenting with initial diagnosis. There was increased intracranial pressure in 50% of patients. Most patients had symptoms >3 months, with three having symptoms 1-3 months before diagnosis and one patient having thoracic dural metastases at presentation. Complete resection was recorded in four patients and six had 50-90% resection. All patients completed craniospinal radiotherapy (35-36 Gy at 1.8-2.0 Gy fractions) barring one patient, who died of surgical complications during his radiotherapy. Chemotherapy was given in five of the nine patients postradiotherapy. There were two posterior fossa recurrences, with associated supratentorial and extra central nervous system disease. Of the 10 primary patients 7 are alive with no evidence of disease, 2 died because of disease, with 1 intercurrent death. One patient developed a second malignancy. The outcome for adults matches that of the more common paediatric patients. Radiotherapy could control local disease even where complete resection was not achieved.
Collapse
Affiliation(s)
- R I Smee
- Department of Radiation Oncology, Prince of Wales Hospital, Sydney, NSW, Australia.
| | | |
Collapse
|
35
|
Abstract
The unique band structure of graphene allows reconfigurable electric-field control of carrier type and density, making graphene an ideal candidate for bipolar nanoelectronics. We report the realization of a single-layer graphene p-n junction in which carrier type and density in two adjacent regions are locally controlled by electrostatic gating. Transport measurements in the quantum Hall regime reveal new plateaus of two-terminal conductance across the junction at 1 and 32 times the quantum of conductance, e(2)/h, consistent with recent theory. Beyond enabling investigations in condensed-matter physics, the demonstrated local-gating technique sets the foundation for a future graphene-based bipolar technology.
Collapse
Affiliation(s)
- J R Williams
- School of Engineering and Applied Science, Harvard University, Cambridge, MA 02138, USA
| | | | | |
Collapse
|
36
|
Abstract
Hydrologic/water quality models are increasingly used to explore management and policy alternatives for managing water quality and quantity from intensive silvicultural practices with best management practices (BMPs) in forested watersheds due to the limited number of and cost of conducting watershed monitoring. The Agricultural Policy/Environmental eXtender (APEX) model was field-tested using 6 yr of data for flow, sediment, nutrient, and herbicide losses collected from nine small (2.58 to 2.74 ha) forested watersheds located in southwest Cherokee County in East Texas. Simulated annual average stream flow for each of the nine watersheds was within +/- 7% of the corresponding observed values; simulated annual average sediment losses were within +/- 8% of measured values for eight out of nine watersheds. Nash-Sutcliffe efficiency (EF) values ranged from 0.68 to 0.94 based on annual stream flow comparison and from 0.60 to 0.99 based on annual sediment comparison. Similar to what was observed, simulated flow, sediment, organic N, and P were significantly increased on clear-cut watersheds compared with the control watersheds. APEX reasonably simulated herbicide losses, with an EF of 0.73 and R(2) of 0.74 for imazapyr, and EF of 0.65 and R(2) of 0.68 for hexazinone based on annual values. Overall, the results show that APEX was able to predict the effects of silvicultural practices with BMPs on water quantity and quality and that the model is a useful tool for simulating a variety of responses to forest conditions.
Collapse
Affiliation(s)
- X Wang
- Texas Agricultural Experiment Stn., Blackland Research and Extension Center, 720 E. Blackland Rd., Temple, TX 76502, USA.
| | | | | | | | | |
Collapse
|
37
|
Abstract
The lack of potable water in arid countries leads to the use of treated sewage water (TSW) for crop growth. Mercury accumulation (up to 500 ng/g) in agricultural soil originating from daily irrigation with TSW was found at two sites fed separately from a hospital sewage plant and an industrial plant. A control site irrigated with potable water ([Hg] <0.01 ng/ml) had much reduced levels in soil (<12 ng/g). Cold-vapour analysis of TSW revealed that Hg concentrations fluctuated widely, and were between 10-100 times higher than those of potable water. The TSW data originated from a total of 46 samples (1 L each), from both plants, collected over a 6-month period. The Hg levels varied from 0.1 to 1.0 ng/ml, which suggested that the possible source of the accumulation could be found in continuous irrigation with comparatively higher Hg levels. Remedial measures could be approached from the perspective of curbing this inconsistency to produce more consistent Hg concentrations below 0.5 ng/ml. It was found that the electrical conductivity of TSW is a useful indicator to rapidly monitor fluctuations in treatment. A novel development in the study was the potential capacity of the plastic TSW discharge-pipes to behave as crude 'chromatographic' columns for possible Hg adsorption. If this property of the pipes is developed further it could have a considerable mitigating effect on the Hg levels. Possible recommendations for remediation to limit the Hg levels and promote sustainable development are discussed.
Collapse
Affiliation(s)
- A E Pillay
- The Petroleum Institute, PO Box 2533, Abu Dhabi, United Arab Emirates.
| | | | | | | |
Collapse
|
38
|
Wang S, Dhar S, Wang SR, Ahyi AC, Franceschetti A, Williams JR, Feldman LC, Pantelides ST. Bonding at the SiC-SiO2 interface and the effects of nitrogen and hydrogen. Phys Rev Lett 2007; 98:026101. [PMID: 17358620 DOI: 10.1103/physrevlett.98.026101] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2006] [Indexed: 05/14/2023]
Abstract
Unlike the Si-SiO2 interface, the SiC-SiO2 interface has large defect densities. Though nitridation has been shown to reduce the defect density, the effect of H remains an open issue. Here we combine experimental data and the results of first-principles calculations to demonstrate that a Si-C-O bonded interlayer with correlated threefold-coordinated C atoms accounts for the observed defect states, for passivation by N and atomic H, and for the nature of residual defects.
Collapse
Affiliation(s)
- Sanwu Wang
- Department of Physics and Engineering Physics, University of Tulsa, Tulsa, Oklahoma 74104, USA
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Williams JR, Foss AM, Vickerman P, Watts C, Ramesh BM, Reza-Paul S, Washington RG, Moses S, Blanchard J, Lowndes CM, Alary M, Boily MC. What is the achievable effectiveness of the India AIDS Initiative intervention among female sex workers under target coverage? Model projections from southern India. Sex Transm Infect 2006; 82:372-80. [PMID: 17012512 PMCID: PMC2563856 DOI: 10.1136/sti.2006.020875] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [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: 07/07/2006] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND The India AIDS Initiative (Avahan) prevention programme funded by the Bill and Melinda Gates Foundation aims to reduce HIV prevalence in high risk groups such as female and male sex workers and their clients, to limit HIV transmission in the general population. OBJECTIVES To assess the potential effectiveness of the Avahan intervention at the level of coverage targeted, in different epidemiological settings in India. METHODS A deterministic compartmental model of the transmission dynamics of HIV and two sexually transmitted infections, and sensitivity analysis techniques, were used, in combination with available behavioural and epidemiological data from Mysore and Bagalkot districts in the Indian state of Karnataka, to evaluate the syndromic sexually transmitted infection (STI) management (STI treatment), periodic presumptive treatment of STI (PPT), and condom components of the Avahan intervention targeted to female sex workers (FSW). RESULTS If all components of the intervention reach target coverage (that is, PPT, STI treatment and condom use), the intervention is expected to prevent 22-35% of all new HIV infections in FSW and in the total population over 5 years in a low transmission setting like Mysore, and to be half as effective in high transmission settings such as Bagalkot. The results were sensitive to small variations in intervention coverage. The condom component alone is expected to prevent around 20% of all new HIV infections over 5 years in Mysore and around 6% for the STI component alone; compared with 7%-14% for the PPT component alone. Multivariate sensitivity analyses suggested that interventions may be more effective in settings with low FSW HIV prevalence and small FSW populations, whereas HIV prevalence was most influenced by sexual behaviour and condom use parameters for FSW. CONCLUSION The Avahan intervention is expected to be effective. However, to be able to demonstrate effectiveness empirically in the different settings, it is important to achieve target coverage or higher, which in the case of PPT could take a number of years to achieve. These preliminary model predictions need to be validated with more detailed mathematical models, as better data on sexual behaviour, condom use, STI and HIV trends over time, and intervention coverage data accumulate over the course of the programme.
Collapse
Affiliation(s)
- J R Williams
- Department of Infectious Disease Epidemiology, Imperial College London, St Mary's Hospital, Norfolk Place, London W2 1PG, UK
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
He X, Izaurralde RC, Vanotti MB, Williams JR, Thomson AM. Simulating long-term and residual effects of nitrogen fertilization on corn yields, soil carbon sequestration, and soil nitrogen dynamics. J Environ Qual 2006; 35:1608-19. [PMID: 16825481 DOI: 10.2134/jeq2005.0259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Soil carbon sequestration (SCS) has the potential to attenuate increasing atmospheric CO2 and mitigate greenhouse warming. Understanding of this potential can be assisted by the use of simulation models. We evaluated the ability of the EPIC model to simulate corn (Zea mays L.) yields and soil organic carbon (SOC) at Arlington, WI, during 1958-1991. Corn was grown continuously on a Typic Argiudoll with three N levels: LTN1 (control), LTN2 (medium), and LTN3 (high). The LTN2 N rate started at 56 kg ha(-1) (1958), increased to 92 kg ha(-1) (1963), and reached 140 kg ha(-1) (1973). The LTN3 N rate was maintained at twice the LTN2 level. In 1984, each plot was divided into four subplots receiving N at 0, 84, 168, and 252 kg ha(-1). Five treatments were used for model evaluation. Percent errors of mean yield predictions during 1958-1983 decreased as N rate increased (LTN1 = -5.0%, LTN2 = 3.5%, and LTN3 = 1.0%). Percent errors of mean yield predictions during 1985-1991 were larger than during the first period. Simulated and observed mean yields during 1958-1991 were highly correlated (R2 = 0.961, p < 0.01). Simulated SOC agreed well with observed values with percent errors from -5.8 to 0.5% in 1984 and from -5.1 to 0.7% in 1990. EPIC captured the dynamics of SOC, SCS, and microbial biomass. Simulated net N mineralization rates were lower than those from laboratory incubations. Improvements in EPIC's ability to predict annual variability of crop yields may lead to improved estimates of SCS.
Collapse
Affiliation(s)
- X He
- Joint Global Change Research Institute, Pacific Northwest National Laboratory, University of Maryland, College Park, MD 20740, USA
| | | | | | | | | |
Collapse
|
41
|
Williams JR, Harrison TR, Grollman A. A SIMPLE METHOD FOR DETERMINING THE SYSTOLIC BLOOD PRESSURE OF THE UNANESTHETIZED RAT. J Clin Invest 2006; 18:373-6. [PMID: 16694670 PMCID: PMC434883 DOI: 10.1172/jci101051] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- J R Williams
- Department of Medicine, Vanderbilt University School of Medicine, Nashville
| | | | | |
Collapse
|
42
|
Al-Hamdi AMH, Williams JR, Al-Kindy SMZ, Pillay AE. Optimization of a High-Performance Liquid Chromatography Method to Quantify Bilirubin and Separate It From Its Photoproducts: Effect of Column Length, pH, Mobile Phase Composition, and Flow Rate. Appl Biochem Biotechnol 2006; 135:209-18. [PMID: 17299208 DOI: 10.1385/abab:135:3:209] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [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: 12/05/2005] [Revised: 11/30/1999] [Accepted: 03/31/2006] [Indexed: 11/11/2022]
Abstract
A rapid reversed-phase (RP) high-performance liquid chromatography method for the isolation of bilirubin from its photoproducts (e.g., biliverdin) is reported. The method is based on isocratic elution using methanol:water as the mobile phase. A 24 full-factorial experimental design approach was adopted. For the optimization, the best separation was obtained using a flow rate of 1.50 mL/min, a mobile phase of 99:1 methanol:water (v/v) at pH 3.60, and a 150 x 4.6 mm id RP (C18) column containing 5-microm particles. These conditions produced the fastest total retention time of 3.38 +/- 0.055 min, and other chromatographic parameters were acceptable. Under the optimum conditions, a linear calibration curve for bilirubin was obtained over the 1.0-40.0 microg/L concentration range studied. The limit of quantification was 0.79 g/L and the limit of detection was 0.24 microg/L. Bilirubin in solution was monitored by ultraviolet detection at 450 nm.
Collapse
Affiliation(s)
- A M H Al-Hamdi
- Department of Chemistry, College of Science, Sultan Qaboos University, Al-Khod 123, Sultanate of Oman, United Arab Emirates
| | | | | | | |
Collapse
|
43
|
Aldridge SE, Lennard TWJ, Williams JR, Birch MA. Vascular endothelial growth factor receptors in osteoclast differentiation and function. Biochem Biophys Res Commun 2005; 335:793-8. [PMID: 16105658 DOI: 10.1016/j.bbrc.2005.07.145] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [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: 07/17/2005] [Accepted: 07/20/2005] [Indexed: 12/11/2022]
Abstract
Osteoclasts are derived from haematopoietic stem cell precursors of the monocyte/macrophage cell lineage, through interaction with factors that are believed to include M-CSF and RANKL. VEGF is a proangiogenic cytokine that has been shown to promote osteoclast differentiation and survival. In this study, we assessed the role of VEGF and its receptors in osteoclastogenesis, in vitro, by culturing osteoclast precursors in the presence of VEGF, VEGF receptor-specific ligands, and blocking antibodies to VEGF receptors. Activation of VEGFR1 in the presence of RANKL induces osteoclast differentiation. Stimulating the receptors individually induced increased resorption by osteoclasts compared to controls but not to the level observed when stimulating both receptors simultaneously. We have shown that VEGF induces osteoclast differentiation through its action on VEGFR1. The way in which VEGF mediates its effect on mature osteoclast activity, however, may be through its interaction with both receptor subtypes.
Collapse
Affiliation(s)
- S E Aldridge
- The School of Surgical Sciences, The Medical School, Framlington Place, University of Newcastle upon Tyne, NE2 4HH, UK.
| | | | | | | |
Collapse
|
44
|
Candal-Couto JJ, Williams JR, Sanderson PL. Impaired forearm rotation after tension-band-wiring fixation of olecranon fractures: evaluation of the transcortical K-wire technique. J Orthop Trauma 2005; 19:480-2. [PMID: 16056081 DOI: 10.1097/01.bot.0000164338.79013.10] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The tension-band-wiring technique is a well-accepted method of internal fixation of olecranon fractures. In addition, it is suggested that transcortical placement of the k-wires results in lower rates wire migration. We encountered two clinical cases in which transcortical placement of the k-wires led to impairment of forearm rotation. An anatomic study was conducted to study the effect of transcortical wire placement to avoid similar future complications. Using specimens from 10 embalmed cadavers, we found that transcortical wires inserted in <30 degrees of ulnar angulation in the coronal plane to the medial ridge of the olecranon, impinged on the radial neck, supinator muscle, or biceps tendon. This was avoided in all 10 specimens when the wires were inserted, with the forearm in supination, at 30 degrees of ulnar angulation. We recommend this technique to be adopted to avoid forearm rotation impairment.
Collapse
Affiliation(s)
- J J Candal-Couto
- Department of Trauma & Orthopaedic Surgery, Freeman Hospital, High Heaton, Newcastle-upon Tyne, England, UK.
| | | | | |
Collapse
|
45
|
Abstract
The goal of this study was to compare the Oxford Shoulder Score (OSS), the Shoulder Pain and Disability Index (SPADI), and the Short Form 36 (SF-36) for their correlation, agreement, sensitivity to change, and test-retest reliability in patients with a clinical diagnosis of subacromial impingement. All patients attending a specialist subacromial impingement clinic over a 6-month period completed the OSS, SPADI, and SF-36 at each visit. A total of 323 sets of observations were recorded in 110 patients. The first 38 of these patients were also sent the questionnaires to complete before their visit. There was good correlation between the OSS and SPADI scores (correlation coefficient = 0.85) and good agreement between the scores on each scale (weighted kappa = 0.79). The correlation with total SF-36 was poor (0.37 for OSS and 0.26 for SPADI). The OSS and SPADI showed good effect sizes compared with the total SF-36 score and good test-retest reliability. These data support the use of the OSS or SPADI in patients with subacromial impingement.
Collapse
Affiliation(s)
- D J Cloke
- Department of Orthopaedics, Freeman Hospital, Newcastle-upon-Tyne, United Kingdom.
| | | | | | | | | | | |
Collapse
|
46
|
Abstract
The authors were involved in developing an ethical framework to assist the Queens Region Board (Prince Edward Island, Canada) set priorities in health and health care. Two and one half years after the adoption of this framework, the authors undertook an evaluation of the framework. This paper will discuss: (a) the historical background of regionalization in Canada, and in particular the circumstances leading up to the institution of regional boards in Prince Edward Island; (b) the sorts of ethical issues facing the Queens Regional Board; (c) issues arising in connection with the use and development of ethics frameworks for managing ethical issues in priority setting; (d) the framework adopted by the Queens Board and the process that led to its development; (e) issues arising as concerns implementation of the framework; (f) questions and issues pertinent to other boards and bodies considering similar initiatives.
Collapse
Affiliation(s)
- M Yeo
- Canadian Medical Association
| | | | | |
Collapse
|
47
|
Abstract
Vascular endothelial growth factor (VEGF) is a proangiogenic cytokine that is expressed highly in many solid tumours often correlating with a poor prognosis. In this study, we investigated the expression of VEGF and its receptors in bone metastases from primary human breast tumours and further characterised its effects on osteoclasts in vitro. Breast cancer metastases to bone were immunohistochemically stained for VEGF, its receptors VEGFR1 and 2 (vascular endothelial growth factor receptor 1 and 2), demonstrating that breast cancer metastases express VEGF strongly and that surrounding osteoclasts express both VEGFR1 and VEGFR2. RAW 264.7 cells (mouse monocyte cell line) and human peripheral blood mononuclear cells (PBMCs) were cultured with VEGF, RANKL and M-CSF. VEGF and RANKL together induced differentiation of multinucleated, tartrate-resistant acid phophatase (TRAP)-positive cells in similar numbers to M-CSF and RANKL. The PBMCs were also able to significantly stimulate resorption of mineralised matrix after treatment with M-CSF with RANKL and VEGF with RANKL. We have shown that VEGF in the presence of RANKL supports PBMC differentiation into osteoclast-like cells, able to resorb substrate. Vascular endothelial growth factor may therefore play a role in physiological bone resorption and in pathological situations. Consequently, VEGF signalling may be a therapeutic target for osteoclast inhibition in conditions such as tumour osteolysis.
Collapse
Affiliation(s)
- S E Aldridge
- The School of Surgical Sciences, The Medical School, Framlington Place, University of Newcastle upon Tyne, NE2 4HH, UK.
| | | | | | | |
Collapse
|
48
|
Abstract
A mathematical model was used to evaluate the impact of the Italian Measles National Elimination Plan (NEP), and possible sources of failure in achieving its targets. The model considered two different estimates of force of infection, and the possible effect on measles transmission of the current Italian demographic situation, characterized by a below-replacement fertility. Results suggest that reaching all NEP targets will allow measles elimination to be achieved. In addition, the model suggests that achieving elimination by reaching a 95 % first-dose coverage appears unlikely; and that conducting catch-up activities, reaching high vaccination coverage, could interrupt virus circulation, but could not prevent the infection re-emerging before 2020. Also, the introduction of the second dose of measles vaccine seems necessary for achieving and maintaining elimination. Furthermore, current Italian demography appears to be favourable for reaching elimination.
Collapse
Affiliation(s)
- P Manfredi
- Dipartimento di Statistica e Matematica Applicata all'Economia, Università di Pisa, Pisa, Italy
| | | | | | | |
Collapse
|
49
|
Dicello JF, Christian A, Cucinotta FA, Gridley DS, Kathirithamby R, Mann J, Markham AR, Moyers MF, Novak GR, Piantadosi S, Ricart-Arbona R, Simonson DM, Strandberg JD, Vazquez M, Williams JR, Zhang Y, Zhou H, Huso D. In vivo mammary tumourigenesis in the Sprague-Dawley rat and microdosimetric correlates. Phys Med Biol 2005; 49:3817-30. [PMID: 15446807 DOI: 10.1088/0031-9155/49/16/024] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [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] [Indexed: 11/11/2022]
Abstract
Standard methods for risk assessments resulting from human exposures to mixed radiation fields in Space consisting of different particle types and energies rely upon quality factors. These are generally defined as a function of linear energy transfer (LET) and are assumed to be proportional to the risk. In this approach, it is further assumed that the risks for single exposures from each of the radiation types add linearly. Although risks of cancer from acute exposures to photon radiations have been measured in humans, quality factors for protons and ions of heavier atomic mass are generally inferred from animal and/or cellular data. Because only a small amount of data exists for such particles, this group has been examining tumourigenesis initiated by energetic protons and iron ions. In this study, 741 female Sprague-Dawley rats were irradiated or sham irradiated at approximately 60 days of age with 250 MeV protons, 1 GeV/nucleon iron ions or both protons and iron ions. The results suggest that the risk of mammary tumours in the rats sequentially irradiated with 1 GeV/nucleon 56Fe ions and 250 MeV protons is less than additive. These data in conjunction with earlier results further suggest that risk assessments in terms of only mean LETs of the primary cosmic rays may be insufficient to accurately evaluate the relative risks of each type of particle in a radiation field of mixed radiation qualities.
Collapse
Affiliation(s)
- J F Dicello
- Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD 21231-2410, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Abstract
OBJECTIVE To determine the prevalence and impact of comorbid psychiatric disturbances in Parkinson disease (PD) patients with psychosis. METHODS Subject data were derived from a research database of 116 PD patients participating in standardized motor, cognitive, psychiatric, and caregiver assessments. RESULTS There were 25 patients (22%) with psychosis manifest as hallucinations (n = 9), delusions (n = 1), or hallucinations and delusions (n = 15) and 25 patients (22%) who had no current or past psychiatric comorbidities (PDN). In the psychotic group, 44% had psychosis only (PSY), and 56% had psychosis plus at least one other comorbid psychiatric disturbance (PSY+), including depressive disorders (71%), anxiety disorders (21%), apathetic syndromes (14%), and delirium (14%). There were no differences in age, sex, education, or age onset or duration of PD among the PSY, PSY+, and PDN groups. Both psychotic groups had greater motor, functional, and frontal cognitive deficits and increased caregiver burden scores relative to PDN. PSY+ showed greater global and selective cognitive deficits compared to PDN. Psychosis was a primary predictor of caregiver burden, whereas depressive symptoms indirectly enhanced motor impairments. CONCLUSIONS Nonpsychotic psychiatric disturbances, especially affective disturbances, are common comorbidities in PD patients with psychosis and warrant clinical attention to reduce morbidity and caregiver distress.
Collapse
Affiliation(s)
- L Marsh
- Department of Psychiatry and Behavioral Sciences, Morris K. Udall Parkinson's Disease Research Center of Excellence at Johns Hopkins, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
| | | | | | | | | | | |
Collapse
|