1,295 research outputs found
Chronic Post-Concussion Neurocognitive Deficits. I. Relationship with White Matter Integrity.
We previously identified visual tracking deficits and associated degradation of integrity in specific white matter tracts as characteristics of concussion. We re-explored these characteristics in adult patients with persistent post-concussive symptoms using independent new data acquired during 2009-2012. Thirty-two patients and 126 normal controls underwent cognitive assessments and MR-DTI. After data collection, a subset of control subjects was selected to be individually paired with patients based on gender and age. We identified patients' cognitive deficits through pairwise comparisons between patients and matched control subjects. Within the remaining 94 normal subjects, we identified white matter tracts whose integrity correlated with metrics that indicated performance degradation in patients. We then tested for reduced integrity in these white matter tracts in patients relative to matched controls. Most patients showed no abnormality in MR images unlike the previous study. Patients' visual tracking was generally normal. Patients' response times in an attention task were slowed, but could not be explained as reduced integrity of white matter tracts relating to normal response timing. In the present patient cohort, we did not observe behavioral or anatomical deficits that we previously identified as characteristic of concussion. The recent cohort likely represented those with milder injury compared to the earlier cohort. The discrepancy may be explained by a change in the patient recruitment pool circa 2007 associated with an increase in public awareness of concussion
Sulfonated copolymers as heparin-mimicking stabilizer of fibroblast growth factor : size, architecture, and monomer distribution effects
Fibroblast growth factors (FGF) are involved in a wide range of biological processes such as cell proliferation and differentiation. In living organisms, the binding of FGF to its receptors are mediated through electrostatic interactions between FGF and naturally occurring heparin. Despite its prevalent use in medicine, heparin carries notable limitations, namely; its extraction from natural sources (expensive, low yield and extensive purification), viral contamination, and batch-to-batch heterogeneity. In this work a range of synthetic homopolymers and copolymers of sodium 2-acrylamido-2-methylpropane sulfonate (AMPS®) were evaluated as potential FGF stabilisers. This was studied by measuring the proliferation of BaF3-FR1c cells, as a model assay, and the results will be compared with the natural stabilisation and activation of FGF by heparin. This study explores the structure-activity relationship of these polysulfonated polymers with a focus on the effect of molecular weight, co-monomer type, charge dispersion and polymer architecture on protein stabilisation
Search and analysis of giant radio galaxies with associated nuclei (SAGAN) -- I : New sample and multi-wavelength studies
We present the first results of a project called SAGAN, which is dedicated
solely to the studies of relatively rare megaparsec-scale radio galaxies in the
Universe, called giant radio galaxies (GRGs). We have identified 162 new GRGs
primarily from the NVSS with sizes ranging from ~0.71 Mpc to 2.82 Mpc in the
redshift range of ~0.03 - 0.95, of which 23 are hosted by quasars (giant radio
quasars, GRQs). As part of the project SAGAN, we have created a database of all
known GRGs, the GRG catalogue, from the literature (including our new sample);
it includes 820 sources. For the first time, we present the multi-wavelength
properties of the largest sample of GRGs. Our results establish that the
distributions of the radio spectral index and the black hole mass of GRGs do
not differ from the corresponding distributions of normal-sized radio galaxies
(RGs). However, GRGs have a lower Eddington ratio (ER) than RGs. Using the
mid-infrared data, we classified GRGs in terms of their accretion mode: either
a high-power radiatively efficient high-excitation state, or a radiatively
inefficient low-excitation state. We find that GRGs in high-excitation state
statistically have larger sizes, stronger radio power, jet kinetic power, and
higher ER than those in low-excitation state. Our analysis reveals a strong
correlation between the ER and the scaled jet kinetic power, which suggests a
disc-jet coupling. Our environmental study reveals that ~10% of all GRGs may
reside at the centres of galaxy clusters, in a denser galactic environment,
while the majority appears to reside in a sparse environment. We find that the
probability of BCG as a GRG is quite low. We present new results for GRGs that
range from black hole mass to large-scale environment properties. We discuss
their formation and growth scenarios, highlighting the key physical factors
that cause them to reach their gigantic size. Abridged.Comment: Accepted for publication in Astronomy & Astrophysics. 14 figures, 7
tables and 7 montages. Comments are welcome. "SAGAN Project website
https://sites.google.com/site/anantasakyatta/sagan
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An Opportunity for Diagonal Development in Global Surgery: Cleft Lip and Palate Care in Resource-Limited Settings
Global cleft surgery missions have provided much-needed care to millions of poor patients worldwide. Still, surgical capacity in low- and middle-income countries is generally inadequate. Through surgical missions, global cleft care has largely ascribed to a vertical model of healthcare delivery, which is disease specific, and tends to deliver services parallel to, but not necessarily within, the local healthcare system. The vertical model has been used to address infectious diseases as well as humanitarian emergencies. By contrast, a horizontal model for healthcare delivery tends to focus on long-term investments in public health infrastructure and human capital and has less often been implemented by humanitarian groups for a variety of reasons. As surgical care is an integral component of basic healthcare, the plastic surgery community must challenge itself to address the burden of specific disease entities, such as cleft lip and palate, in a way that sustainably expands and enriches global surgical care as a whole. In this paper, we describe a diagonal care delivery model, whereby cleft missions can enrich surgical capacity through integration into sustainable, local care delivery systems. Furthermore, we examine the applications of diagonal development to cleft care specifically and global surgical care more broadly
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The LONI QC System: A Semi-Automated, Web-Based and Freely-Available Environment for the Comprehensive Quality Control of Neuroimaging Data.
Quantifying, controlling, and monitoring image quality is an essential prerequisite for ensuring the validity and reproducibility of many types of neuroimaging data analyses. Implementation of quality control (QC) procedures is the key to ensuring that neuroimaging data are of high-quality and their validity in the subsequent analyses. We introduce the QC system of the Laboratory of Neuro Imaging (LONI): a web-based system featuring a workflow for the assessment of various modality and contrast brain imaging data. The design allows users to anonymously upload imaging data to the LONI-QC system. It then computes an exhaustive set of QC metrics which aids users to perform a standardized QC by generating a range of scalar and vector statistics. These procedures are performed in parallel using a large compute cluster. Finally, the system offers an automated QC procedure for structural MRI, which can flag each QC metric as being 'good' or 'bad.' Validation using various sets of data acquired from a single scanner and from multiple sites demonstrated the reproducibility of our QC metrics, and the sensitivity and specificity of the proposed Auto QC to 'bad' quality images in comparison to visual inspection. To the best of our knowledge, LONI-QC is the first online QC system that uniquely supports the variety of functionality where we compute numerous QC metrics and perform visual/automated image QC of multi-contrast and multi-modal brain imaging data. The LONI-QC system has been used to assess the quality of large neuroimaging datasets acquired as part of various multi-site studies such as the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) Study and the Alzheimer's Disease Neuroimaging Initiative (ADNI). LONI-QC's functionality is freely available to users worldwide and its adoption by imaging researchers is likely to contribute substantially to upholding high standards of brain image data quality and to implementing these standards across the neuroimaging community
Decreasing adrenergic or sympathetic hyperactivity after severe traumatic brain injury using propranolol and clonidine (DASH After TBI Study): study protocol for a randomized controlled trial
BACKGROUND: Severe TBI, defined as a Glasgow Coma Scale ≤ 8, increases intracranial pressure and activates the sympathetic nervous system. Sympathetic hyperactivity after TBI manifests as catecholamine excess, hypertension, abnormal heart rate variability, and agitation, and is associated with poor neuropsychological outcome. Propranolol and clonidine are centrally acting drugs that may decrease sympathetic outflow, brain edema, and agitation. However, there is no prospective randomized evidence available demonstrating the feasibility, outcome benefits, and safety for adrenergic blockade after TBI. METHODS/DESIGN: The DASH after TBI study is an actively accruing, single-center, randomized, double-blinded, placebo-controlled, two-arm trial, where one group receives centrally acting sympatholytic drugs, propranolol (1 mg intravenously every 6 h for 7 days) and clonidine (0.1 mg per tube every 12 h for 7 days), and the other group, double placebo, within 48 h of severe TBI. The study uses a weighted adaptive minimization randomization with categories of age and Marshall head CT classification. Feasibility will be assessed by ability to provide a neuroradiology read for randomization, by treatment contamination, and by treatment compliance. The primary endpoint is reduction in plasma norepinephrine level as measured on day 8. Secondary endpoints include comprehensive plasma and urine catecholamine levels, heart rate variability, arrhythmia occurrence, infections, agitation measures using the Richmond Agitation-Sedation Scale and Agitated Behavior scale, medication use (anti-hypertensive, sedative, analgesic, and antipsychotic), coma-free days, ventilator-free days, length of stay, and mortality. Neuropsychological outcomes will be measured at hospital discharge and at 3 and 12 months. The domains tested will include global executive function, memory, processing speed, visual-spatial, and behavior. Other assessments include the Extended Glasgow Outcome Scale and Quality of Life after Brain Injury scale. Safety parameters evaluated will include cardiac complications. DISCUSSION: The DASH After TBI Study is the first randomized, double-blinded, placebo-controlled trial powered to determine feasibility and investigate safety and outcomes associated with adrenergic blockade in patients with severe TBI. If the study results in positive trends, this could provide pilot evidence for a larger multicenter randomized clinical trial. If there is no effect of therapy, this trial would still provide a robust prospective description of sympathetic hyperactivity after TBI. TRIAL REGISTRATION: ClinicalTrials.gov NCT0132204
Health and lifestyle of Nepalese migrants in the UK
Background: The health status and lifestyle of migrants is often poorer than that of the general
population of their host countries. The Nepalese represent a relatively small, but growing,
immigrant community in the UK, about whom very little is known in term of public health.
Therefore, our study examined the health and lifestyle of Nepalese migrants in the UK.
Methods: A cross-sectional survey of Nepalese migrants in UK was conducted in early 2007 using
a postal, self-administered questionnaire in England and Scotland (n = 312), and telephone
interviews in Wales (n = 15). The total response rate was 68% (327 out of 480). Data were analyzed
to establish whether there are associations between socio-economic and lifestyle factors. A
multivariate binary logistic regression was applied to find out independent effect of personal factors
on health status.
Results: The majority of respondents was male (75%), aged between 30 and 45 (66%), married or
had a civil partner (83%), had university education (47%) and an annual family income (69%) ranging
from £5,035 to £33,300. More than one third (39%) of the respondents have lived in the UK for 1
to 5 years and approximately half (46%) were longer-term residents. Most (95%) were registered
with a family doctor, but only 38% with a dentist. A low proportion (14%) of respondents smoked
but more than half (61%) consumed alcohol. More than half (57%) did not do regular exercises and
nearly one fourth (23%) of respondents rated their health as poor. Self reported 'good' health
status of the respondents was independently associated with immigration status and doing regular exercise
Conclusion: The self reported health status and lifestyle, health seeking behaviour of Nepalese
people who are residing in UK appears to be good. However, the overall regular exercise and dentist registration was rather poor. Health promotion, especially aimed at Nepalese migrants could help encourage them to exercise regularly and assist them to register with a dentist
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