73 research outputs found
A Study of Atmospheric Aerosols in The Bahamas Using Camera Lidar and Star Photometry Techniques
Aerosols, the tiny suspended particles in the atmosphere, are a widely studied topic around the world due to their effects on the Earthâs radiation budget, climate change, and human health. Knowledge of the spatial and temporal distribution of aerosols is essential to assess air pollution and predict potential climate change. This study measured aerosol optical depth (AOD) and altitude-dependent aerosol extinctions in Nassau, The Bahamas simultaneously using a camera-based imaging lidar (CLidar). The bistatic geometry of the setup which consisted of a wide-angle lens fitted to a charge-coupled device (CCD) camera, allowed for the measurement of extinctions at all altitudes at once without requiring expensive timing electronics common to lidars. A case study was conducted on November 5, 2018. The top of the boundary layer beyond which aerosol extinction was nearly zero was detected at ~ three km above sea level. Due to the excellent resolution of the CLidar at lower altitudes, variations of aerosol concentrations within the boundary layer are efficiently detected. Optical depth was measured using the same CLidar camera at the same time, utilising star photometry, and was found to be 0.043 ± 0.040. The value falls within the range of assumed values of AOD near the regions obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua satellite
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Self-reactive human CD4 T cell clones form unusual immunological synapses
Recognition of selfâpeptide-MHC (pMHC) complexes by CD4 T cells plays an important role in the pathogenesis of many autoimmune diseases. We analyzed formation of immunological synapses (IS) in self-reactive T cell clones from patients with multiple sclerosis and type 1 diabetes. All self-reactive T cells contained a large number of phosphorylated T cell receptor (TCR) microclusters, indicative of active TCR signaling. However, they showed little or no visible pMHC accumulation or transport of TCRâpMHC complexes into a central supramolecular activation cluster (cSMAC). In contrast, influenza-specific T cells accumulated large quantities of pMHC complexes in microclusters and a cSMAC, even when presented with 100-fold lower pMHC densities. The self-reactive T cells also maintained a high degree of motility, again in sharp contrast to virus-specific T cells. 2D affinity measurements of three of these self-reactive T cell clones demonstrated a normal off-rate but a slow on-rate of TCR binding to pMHC. These unusual IS features may facilitate escape from negative selection by self-reactive T cells encountering very small amounts of self-antigen in the thymus. However, these same features may enable acquisition of effector functions by self-reactive T cells encountering large amounts of self-antigen in the target organ of the autoimmune disease
Exploring the modification of Sunday hunting restrictions on wildlife management areas in South Carolina
This report examines Sunday hunting restrictions on Wildlife Management Areas (WMA) in the state of South Carolina, and what person and community level factors may promote and/or inhibit the expansion of hunting to include Sundays. Two sources of data are specifically examined in the report: (1) five listening sessions facilitated by SCDNR leadership across the state of South Carolina, and (2) a web-based questionnaire distributed through multiple channels to both hunters and non-hunters. This report provides the South Carolina Department of Natural Resources (SCDNR) with user-feedback to make evidence based decisions regarding the management of hunting on WMAs in collaboration with partners across the state of South Carolina
Does vitamin D supplementation alter plasma adipokines concentrations? A systematic review and meta-analysis of randomized controlled trials
We aimed to elucidate the role of vitamin D supplementation on adipokines through a systematic review and a meta-analysis of randomized placebo-controlled trials (RCTs). The search included PUBMED, Scopus, Web of Science and Google Scholar through July 1st, 2015. Finally we identified 9 RCTs and 484 participants. Meta-analysis of data from 7 studies did not find a significant change in plasma adiponectin concentrations following vitamin D supplementation (mean difference [MD]: 4.45%, 95%CI: â3.04, 11.93, p = 0.244; Q = 2.18, I2 = 0%). In meta-regression, changes in plasma adiponectin concentrations following vitamin D supplementation were found to be independent of treatment duration (slope: 0.25; 95%CI: â0.69, 1.19; p = 0.603) and changes in serum 25-hydroxy vitamin D [25(OH)D] levels (slope: â0.02; 95%CI: â0.15, 0.12; p = 0.780). Meta-analysis of data from 6 studies did not find a significant change in plasma leptin concentrations following vitamin D supplementation (MD: â4.51%, 95%CI: â25.13, 16.11, p = 0.668; Q = 6.41, I2 = 21.97%). Sensitivity analysis showed that this effect size is sensitive to one of the studies; removing it resulted in a significant reduction in plasma leptin levels (MD: â12.81%, 95%CI: â24.33, â1.30, p = 0.029). In meta-regression, changes in plasma leptin concentrations following vitamin D supplementation were found to be independent of treatment duration (slope: â1.93; 95%CI: â4.08, 0.23; p = 0.080). However, changes in serum 25(OH)D were found to be significantly associated with changes in plasma leptin levels following vitamin D supplementation (slope: 1.05; 95%CI: 0.08, 2.02; p = 0.033). In conclusion, current data did not indicate a significant effect of vitamin D supplementation on adiponectin and leptin levels
Inflammation-dependent cerebrospinal fluid hypersecretion by the choroid plexus epithelium in posthemorrhagic hydrocephalus
This is the author accepted manuscript. The final version is available from Springer Nature via the DOI in this recordThere is another record in ORE for this publication: http://hdl.handle.net/10871/33419The choroid plexus epithelium (CPE) secretes higher volumes of fluid (cerebrospinal fluid, CSF) than any other epithelium and simultaneously functions as the blood-CSF barrier to gate immune cell entry into the central nervous system. Posthemorrhagic hydrocephalus (PHH), an expansion of the cerebral ventricles due to CSF accumulation following intraventricular hemorrhage (IVH), is a common disease usually treated by suboptimal CSF shunting techniques. PHH is classically attributed to primary impairments in CSF reabsorption, but little experimental evidence supports this concept. In contrast, the potential contribution of CSF secretion to PHH has received little attention. In a rat model of PHH, we demonstrate that IVH causes a Toll-like receptor 4 (TLR4)- and NF-ÎșB-dependent inflammatory response in the CPE that is associated with a âŒ3-fold increase in bumetanide-sensitive CSF secretion. IVH-induced hypersecretion of CSF is mediated by TLR4-dependent activation of the Ste20-type stress kinase SPAK, which binds, phosphorylates, and stimulates the NKCC1 co-transporter at the CPE apical membrane. Genetic depletion of TLR4 or SPAK normalizes hyperactive CSF secretion rates and reduces PHH symptoms, as does treatment with drugs that antagonize TLR4-NF-ÎșB signaling or the SPAK-NKCC1 co-transporter complex. These data uncover a previously unrecognized contribution of CSF hypersecretion to the pathogenesis of PHH, demonstrate a new role for TLRs in regulation of the internal brain milieu, and identify a kinase-regulated mechanism of CSF secretion that could be targeted by repurposed US Food and Drug Administration (FDA)-approved drugs to treat hydrocephalus.We thank D.R. Alessi (Dundee) and R.P. Lifton (Rockefeller) for their support. K.T.K. is supported by the March of Dimes Basil O'Connor Award, a Simons Foundation SFARI Grant, the Hydrocephalus Association Innovator Award, and the NIH (4K12NS080223-05). J.M.S. is supported by the National Institute of Neurological Disorders and Stroke (NINDS) (NS060801; NS061808) and the US Department of Veterans Affairs (1BX002889); R.M. is supported by the Howard Hughes Medical Institute
Rediscovering the value of families for psychiatric genetics research
As it is likely that both common and rare genetic variation are important for complex disease risk, studies that examine the full range of the allelic frequency distribution should be utilized to dissect the genetic influences on mental illness. The rate limiting factor for inferring an association between a variant and a phenotype is inevitably the total number of copies of the minor allele captured in the studied sample. For rare variation, with minor allele frequencies of 0.5% or less, very large samples of unrelated individuals are necessary to unambiguously associate a locus with an illness. Unfortunately, such large samples are often cost prohibitive. However, by using alternative analytic strategies and studying related individuals, particularly those from large multiplex families, it is possible to reduce the required sample size while maintaining statistical power. We contend that using whole genome sequence (WGS) in extended pedigrees provides a cost-effective strategy for psychiatric gene mapping that complements common variant approaches and WGS in unrelated individuals. This was our impetus for forming the âPedigree-Based Whole Genome Sequencing of Affective and Psychotic Disordersâ consortium. In this review, we provide a rationale for the use of WGS with pedigrees in modern psychiatric genetics research. We begin with a focused review of the current literature, followed by a short history of family-based research in psychiatry. Next, we describe several advantages of pedigrees for WGS research, including power estimates, methods for studying the environment, and endophenotypes. We conclude with a brief description of our consortium and its goals.This research was supported by National Institute of Mental Health grants U01 MH105630 (DCG), U01 MH105634 (REG), U01 MH105632 (JB), R01 MH078143 (DCG), R01 MH083824 (DCG & JB), R01 MH078111 (JB), R01 MH061622 (LA), R01 MH042191 (REG), and R01 MH063480 (VLN).UCR::VicerrectorĂa de InvestigaciĂłn::Unidades de InvestigaciĂłn::Ciencias BĂĄsicas::Centro de InvestigaciĂłn en BiologĂa Celular y Molecular (CIBCM)UCR::VicerrectorĂa de Docencia::Ciencias BĂĄsicas::Facultad de Ciencias::Escuela de BiologĂ
Mobile-Enhanced Field Research: Biocore Plant Identification
In this report, we discuss a pilot study of a plant identification field research activity in an undergraduate âBiocore: Ecology, Genetics, and Evolutionâ laboratory course at the University of WisconsinâMadison. This study investigates the efficiency and accuracy of using mobile devices for field research data collection activities. We draw from theories of distributed cognition (Cole & Engeström 1993; Hutchins, 1995) and situated learning (Brown, Collins& Duguid, 1989; Lave & Wenger, 1991) to explore how novices use mobile devices in the field to collect data. We conducted a design experiment(Brown, 1995), and we offer our findings and their implications for the development of a generalized field research platform
Chandra X-Ray Observations of PSR J1849-0001, Its Pulsar Wind Nebula, and the TeV Source HESS J1849-000
We obtained a 108 ks Chandra X-ray Observatory (CXO) observation of PSR J1849-0001 and its pulsar wind nebula (PWN) coincident with the TeV source HESS J1849-000. By analyzing the new and old (archival) CXO data, we resolved the pulsar from the PWN, explored the PWN morphology on arcsecond and arcminute scales, and measured the spectra of different regions of the PWN. Both the pulsar and the compact inner PWN spectra are hard with power-law photon indices of 1.20 ± 0.07 and 1.49 ± 0.20, respectively. The jet-dominated PWN has a relatively low luminosity, lack of Îł -ray pulsations, relatively hard and nonthermal spectrum of the pulsar, and sine-like pulse profile, which indicates a relatively small angle between the pulsarâs spin and magnetic dipole axis. In this respect, it shares similar properties with a few other so-called MeV pulsars. Although the joint X-ray and TeV spectral energy distribution can be roughly described by a single-zone model, the obtained magnetic field value is unrealistically low. A more realistic scenario is the presence of a relic PWN, no longer emitting synchrotron X-rays but still radiating in TeV via inverse-Compton upscattering. We also serendipitously detected surprisingly bright X-ray emission from a very wide binary whose components should not be interacting
Reverse end-to-side neurotization in a regenerating nerve.
Bypass grafting around a neuroma-in-continuity entails coapting a nerve graft above and below the injured segment using two sequential end-to-side repairs. The proximal repair is analogous to what has been classically described as an end-to-side repair; the axons from the intact nerve sprout into the end of a recipient nerve and travel distally. At the distal connection, however, axons in the graft must enter the side of the intact nerve and find their way to appropriate end organs. This process has not been well investigated. To examine this, a reverse end-to-side repair, suturing the distal end of the peroneal nerve to the side of a transected and repaired tibial nerve, was performed in 20 rats. A primary end-to-end repair of the tibial nerve was performed in 10 additional rats. Twelve weeks later, contraction forces of the gastrocnemius muscle were measured following proximal stimulation. Measurements were repeated following elimination of potential axonal pathways to identify which axons (peroneal or tibial) had achieved greater reinnervation. The results indicated that both groups of axons had achieved significant reinnervation. This study supports the idea that a reverse end-to-side repair can result in axonal invasion of an intact but regenerating nerve and achieve functional recovery
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