561 research outputs found
Into the Wasteland: Applying Equality Principles to Medical Inadmissibility in Canadian Immigration Law
Into the Wasteland: Applying Equality Principles to Medical Inadmissibility in Canadian Immigration Law
Advancing Social Justice Through an Interdisciplinary Approach to Clinical Legal Education: The Case of Legal Assistance of Windsor
Since its inception in 1974, the University of Windsor’s Clinical Law Program at Legal Assistance of Windsor (LAW) has placed law students in a downtown community legal clinic staffed by lawyers and social workers. As an interdisciplinary clinical legal education program whose mission is “to provide access to justice to the poor,” LAW holds numerous possibilities for advancing a social justice agenda in both professional education and practice. In this Essay, however, we suggest that its success in this regard depends upon renewed and purposeful attention to certain critical factors: (1) a shared understanding of LAW’s goals and values; (2) curriculum design that is reflective of these goals and values; and (3) institutional sanction and support for the goals and values
DESIGN STUDIES ON CESIUM-137 AS A SOURCE FOR HIGH LEVEL GAMMA IRRADIATIONS. Quarterly Progress Report No. 2 Covering the Period from Sept. 1, 1959 to Dec. 1, 1959
Further studies are reported on the analytical behavior and experimental testing of Cs/sup 137/ plaque irradiator designs. Low-level sources used for the initial experiments consisted of about 7 mc of Cs/sup 137/ aqueous solution in brass trays 20 by 20 by 1/2 in. high having wall thicknesses of 1/16 in. Calibration tests were made preliminary to radiation field mapping. (T.R. H.
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The Role of syndecan-1 in flow-mediated endothelial mechanotransduction
Cardiovascular disease kills over 750,000 people in the United States and an estimated 17.3 million people worldwide each year. Atherosclerosis, the formation of lipid-rich plaques in the walls of blood vessels, is the primary driver of complications in cardiovascular disease. These plaques partially or totally occlude downstream blood flow, resulting in ischemia and in peripheral limbs can require amputation. Alternatively, they can develop a vulnerable ‘fibrous cap’ phenotype that is susceptible to rupture, leading to a massive thrombotic cascade that can cause stroke or myocardial infarction. Current treatments predominately focus on either physically opening the blood vessels (e.g. balloon catheters and stenting) or creating bypass grafts. These treatments, however, frequently need to be repeated, particularly if patients do not change their dietary and exercise protocols. Therefore, a new approach to treating atherosclerosis that targets the mechanisms that drive vessels towards a pathogenic phenotype could be extremely helpful for preventing disease.
Endothelial cells line blood vessels and are the principle cells responsible for interactions between blood flow and the surrounding tissue. In addition to providing a barrier, they are capable of sensing the mechanical forces induced by the blood flow. This sensing mechanism is responsible for driving their phenotype between an ‘atheroprotective’ or ‘atheroprone’ state; specifically, steady laminar shear stress results in ‘healthy’ endothelial cells while low or oscillatory shear stresses induces an inflammatory phenotype. While research has been conducted to look at the effects of shear stress on endothelial cells, the initial sensing mechanism that drives these downstream pathways remains unclear. Here we investigate the heparan sulfate proteoglycan syndecan-1 as a potential upstream regulator of these changes. Using custom-built shear stress application devices, we show that endothelial cells lacking syndecan-1 have a reduced response to shear stress and a general increase in inflammatory state. In vivo studies in a knockout mouse model extend these results; syndecan-1 knockout mice have more pronounced inflammatory responses and an increase in leukocyte-binding proteins in low shear conditions. These findings illustrate syndecan-1 as a potential target for future therapeutics aimed at driving potentially vulnerable vasculature away from a pathogenic phenotype.Biomedical Engineerin
Automated Real-Time Behavioral and Physiological Data Acquisition and Display Integrated with Stimulus Presentation for fMRI
Functional magnetic resonance imaging (fMRI) is based on correlating blood oxygen-level dependent (BOLD) signal fluctuations in the brain with other time-varying signals. Although the most common reference for correlation is the timing of a behavioral task performed during the scan, many other behavioral and physiological variables can also influence fMRI signals. Variations in cardiac and respiratory functions in particular are known to contribute significant BOLD signal fluctuations. Variables such as skin conduction, eye movements, and other measures that may be relevant to task performance can also be correlated with BOLD signals and can therefore be used in image analysis to differentiate multiple components in complex brain activity signals. Combining real-time recording and data management of multiple behavioral and physiological signals in a way that can be routinely used with any task stimulus paradigm is a non-trivial software design problem. Here we discuss software methods that allow users control of paradigm-specific audio–visual or other task stimuli combined with automated simultaneous recording of multi-channel behavioral and physiological response variables, all synchronized with sub-millisecond temporal accuracy. We also discuss the implementation and importance of real-time display feedback to ensure data quality of all recorded variables. Finally, we discuss standards and formats for storage of temporal covariate data and its integration into fMRI image analysis. These neuroinformatics methods have been adopted for behavioral task control at all sites in the Functional Biomedical Informatics Research Network (FBIRN) multi-center fMRI study
DESIGN STUDIES ON CESIUM-137 AS A SOURCE FOR HIGH LEVEL GAMMA IRRADIATORS. Quarterly Progress Report No. 1 covering the Period June 1 to August 31, 1959
A study was made of radiation physics problems involved in the design of high-level cesium-137 gamma sources. The radiation properties of cesium-137 sources are reviewed and design and dosimetry problems are discussed. The economics, efficiency, and dose distribution for material undergoing process irradiation were calculated. A comparison of cesium-137 with cobalt-60 gamma sources indicated that in the case of irradiators specifically designed for high efficiency of useful energy conversion, the performance of cesium-137 source material should be at least comparable to the performance of cobalt-60 source material. (C.H.
Presurgical language fMRI: Mapping of six critical regions.
Language mapping is a key goal in neurosurgical planning. fMRI mapping typically proceeds with a focus on Broca's and Wernicke's areas, although multiple other language-critical areas are now well-known. We evaluated whether clinicians could use a novel approach, including clinician-driven individualized thresholding, to reliably identify six language regions, including Broca's Area, Wernicke's Area (inferior, superior), Exner's Area, Supplementary Speech Area, Angular Gyrus, and Basal Temporal Language Area. We studied 22 epilepsy and tumor patients who received Wada and fMRI (age 36.4[12.5]; Wada language left/right/mixed in 18/3/1). fMRI tasks (two × three tasks) were analyzed by two clinical neuropsychologists who flexibly thresholded and combined these to identify the six regions. The resulting maps were compared to fixed threshold maps. Clinicians generated maps that overlapped significantly, and were highly consistent, when at least one task came from the same set. Cases diverged when clinicians prioritized different language regions or addressed noise differently. Language laterality closely mirrored Wada data (85% accuracy). Activation consistent with all six language regions was consistently identified. In blind review, three external, independent clinicians rated the individualized fMRI language maps as superior to fixed threshold maps; identified the majority of regions significantly more frequently; and judged language laterality to mirror Wada lateralization more often. These data provide initial validation of a novel, clinician-based approach to localizing language cortex. They also demonstrate clinical fMRI is superior when analyzed by an experienced clinician and that when fMRI data is of low quality judgments of laterality are unreliable and should be withheld. Hum Brain Mapp 38:4239-4255, 2017. © 2017 Wiley Periodicals, Inc
A Multi-site Resting State fMRI Study on the Amplitude of Low Frequency Fluctuations in Schizophrenia
Background: This multi-site study compares resting state fMRI amplitude of low frequency fluctuations (ALFF) and fractional ALFF (fALFF) between patients with schizophrenia (SZ) and healthy controls (HC). Methods: Eyes-closed resting fMRI scans (5:38 min; n = 306, 146 SZ) were collected from 6 Siemens 3T scanners and one GE 3T scanner. Imaging data were pre-processed using an SPM pipeline. Power in the low frequency band (0.01–0.08 Hz) was calculated both for the original pre-processed data as well as for the pre-processed data after regressing out the six rigid-body motion parameters, mean white matter (WM) and cerebral spinal fluid (CSF) signals. Both original and regressed ALFF and fALFF measures were modeled with site, diagnosis, age, and diagnosis × age interactions. Results: Regressing out motion and non-gray matter signals significantly decreased fALFF throughout the brain as well as ALFF in the cortical edge, but significantly increased ALFF in subcortical regions. Regression had little effect on site, age, and diagnosis effects on ALFF, other than to reduce diagnosis effects in subcortical regions. There were significant effects of site across the brain in all the analyses, largely due to vendor differences. HC showed greater ALFF in the occipital, posterior parietal, and superior temporal lobe, while SZ showed smaller clusters of greater ALFF in the frontal and temporal/insular regions as well as in the caudate, putamen, and hippocampus. HC showed greater fALFF compared with SZ in all regions, though subcortical differences were only significant for original fALFF. Conclusions: SZ show greater eyes-closed resting state low frequency power in frontal cortex, and less power in posterior lobes than do HC; fALFF, however, is lower in SZ than HC throughout the cortex. These effects are robust to multi-site variability. Regressing out physiological noise signals significantly affects both total and fALFF measures, but does not affect the pattern of case/control differences
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