137 research outputs found
Preliminary Ground-Based Observation for the Soil Moisture Measurement Validation of ADEOS II-AMSR/AMSR-E
研究概要:AMSR-E(2002年3月打ち上げ予定)とAMSR (2002年11月打ち上げ予定)の土壌水分測定アルゴリズムの検証のために、モンゴル高原で地上検証用試験地の設定と検証のための準備観測(モニタリングと集中土壌水分・植物水分移動観測)を行った。試験地内の降雨分布および土壌水分と植物水分の分布には地域的な差異があることが分かると共に変化幅も検証に値するものであることが分かった
Increased ventral striatal volume in college-aged binge drinkers
BACKGROUND
Binge drinking is a serious public health issue associated with cognitive, physiological, and anatomical differences from healthy individuals. No studies, however, have reported subcortical grey matter differences in this population. To address this, we compared the grey matter volumes of college-age binge drinkers and healthy controls, focusing on the ventral striatum, hippocampus and amygdala.
METHOD
T1-weighted images of 19 binge drinkers and 19 healthy volunteers were analyzed using voxel-based morphometry. Structural data were also covaried with Alcohol Use Disorders Identification Test (AUDIT) scores. Cluster-extent threshold and small volume corrections were both used to analyze imaging data.
RESULTS
Binge drinkers had significantly larger ventral striatal grey matter volumes compared to controls. There were no between group differences in hippocampal or amygdalar volume. Ventral striatal, amygdalar, and hippocampal volumes were also negatively related to AUDIT scores across groups.
CONCLUSIONS
Our findings stand in contrast to the lower ventral striatal volume previously observed in more severe forms of alcohol use disorders, suggesting that college-age binge drinkers may represent a distinct population from those groups. These findings may instead represent early sequelae, compensatory effects of repeated binge and withdrawal, or an endophenotypic risk factor
The treatment-related experiences of parents, children and young people with regular prescribed medication
Background Taking regular medication has been shown to have an impact on the daily lives of patients and their families. Objective To explore the medication-related experiences of patients and their families when a child or young person is prescribed regular medication. Setting A specialist U.K. paediatric hospital. Method Semi-structured face-to-face interviews of 24 parents/carers, children or young people, who had been taking two or more medications for 6 weeks or longer. The themes explored included the medication regimen, formulation, supplies, social aspects and adverse effects. The data was analysed using NVIVO version 11. Main outcome measure The experiences of patients, and their parents/carers, when a child/young person takes regular medication. Results Participants described a range of experiences associated with taking regular medication. Medication-related challenges were experienced around the timing of administration which was managed over 24 h rather than waking hours. Updating medication doses for administration at school was often delayed. Unintended nonadherence was cited as the biggest challenge with a range of strategies employed to manage this. The internet was commonly used as a source of additional information accessed for reassurance and adverse effects but there were varying experiences of using patient forums/help groups. Other challenges included the adequacy of information, travelling with medication, formulation issues, arranging supplies and adverse effects. Conclusion Patients and parents experience many challenges with children’s medication. Individualised treatment options should be considered. Further research is required to determine how these experiences may be managed including the role of paediatric medication review
Genomic identification of cryptic susceptibility to penicillins and β-lactamase inhibitors in methicillin-resistant Staphylococcus aureus.
Antibiotic resistance in bacterial pathogens threatens the future of modern medicine. One such resistant pathogen is methicillin-resistant Staphylococcus aureus (MRSA), which is resistant to nearly all β-lactam antibiotics, limiting treatment options. Here, we show that a significant proportion of MRSA isolates from different lineages, including the epidemic USA300 lineage, are susceptible to penicillins when used in combination with β-lactamase inhibitors such as clavulanic acid. Susceptibility is mediated by a combination of two different mutations in the mecA promoter region that lowers mecA-encoded penicillin-binding protein 2a (PBP2a) expression, and in the majority of isolates by either one of two substitutions in PBP2a (E246G or M122I) that increase the affinity of PBP2a for penicillin in the presence of clavulanic acid. Treatment of S. aureus infections in wax moth and mouse models shows that penicillin/β-lactamase inhibitor susceptibility can be exploited as an effective therapeutic choice for 'susceptible' MRSA infection. Finally, we show that isolates with the PBP2a E246G substitution have a growth advantage in the presence of penicillin but the absence of clavulanic acid, which suggests that penicillin/β-lactamase susceptibility is an example of collateral sensitivity (resistance to one antibiotic increases sensitivity to another). Our findings suggest that widely available and currently disregarded antibiotics could be effective in a significant proportion of MRSA infections.MRC - G1001787/1
MRC - MR/N002660/1
WT098600
HICF-T5-342
MR/S00291X/1
201344/Z/16/Z
MR/P007201/
Overview and status of EXCLAIM, the experiment for cryogenic large-aperture intensity mapping
The EXperiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM) is a
balloon-borne far-infrared telescope that will survey star formation history
over cosmological time scales to improve our understanding of why the star
formation rate declined at redshift z < 2, despite continued clustering of dark
matter. Specifically,EXCLAIM will map the emission of redshifted carbon
monoxide and singly-ionized carbon lines in windows over a redshift range 0 < z
< 3.5, following an innovative approach known as intensity mapping. Intensity
mapping measures the statistics of brightness fluctuations of cumulative line
emissions instead of detecting individual galaxies, thus enabling a blind,
complete census of the emitting gas. To detect this emission unambiguously,
EXCLAIM will cross-correlate with a spectroscopic galaxy catalog. The EXCLAIM
mission uses a cryogenic design to cool the telescope optics to approximately
1.7 K. The telescope features a 90-cm primary mirror to probe spatial scales on
the sky from the linear regime up to shot noise-dominated scales. The telescope
optical elements couple to six {\mu}-Spec spectrometer modules, operating over
a 420-540 GHz frequency band with a spectral resolution of 512 and featuring
microwave kinetic inductance detectors. A Radio Frequency System-on-Chip
(RFSoC) reads out the detectors in the baseline design. The cryogenic telescope
and the sensitive detectors allow EXCLAIM to reach high sensitivity in spectral
windows of low emission in the upper atmosphere. Here, an overview of the
mission design and development status since the start of the EXCLAIM project in
early 2019 is presented.Comment: SPIE Astronomical Telescopes + Instrumentation. arXiv admin note:
substantial text overlap with arXiv:1912.0711
Assessment of population genetic structure in the arbovirus vector midge, Culicoides brevitarsis (Diptera Ceratopogonidae), using multi-locus DNA microsatellites
Bluetongue virus (BTV) is a major pathogen of ruminants that is transmitted by biting midges (Culicoides spp.). Australian BTV serotypes have origins in Asia and are distributed across the continent into two distinct episystems, one in the north and another in the east. Culicoides brevitarsis is the major vector of BTV in Australia and is distributed across the entire geographic range of the virus. Here, we describe the isolation and use of DNA microsatellites and gauge their ability to determine population genetic connectivity of C. brevitarsis within Australia and with countries to the north. Eleven DNA microsatellite markers were isolated using a novel genomic enrichment method and identified as useful for genetic analyses of sampled populations in Australia, northern Papua New Guinea (PNG) and Timor-Leste. Significant (P < 0.05) population genetic subdivision was observed between all paired regions, though the highest levels of genetic sub-division involved pair-wise tests with PNG (PNG vs. Australia (F-ST = 0.120) and PNG vs. Timor-Leste (F-ST = 0.095)). Analysis of multi-locus allelic distributions using STRUCTURE identified a most probable two-cluster population model, which separated PNG specimens from a cluster containing specimens from Timor-Leste and Australia. The source of incursions of this species in Australia is more likely to be Timor-Leste than PNG. Future incursions of BTV positive C. brevitarsis into Australia may be genetically identified to their source populations using these microsatellite loci. The vector's panmictic genetic structure within Australia cannot explain the differential geographic distribution of BTV serotypes
Remodeling of the Cortical Structural Connectome in Posttraumatic Stress Disorder:Results from the ENIGMA-PGC PTSD Consortium
BACKGROUND: Posttraumatic stress disorder (PTSD) is accompanied by disrupted cortical neuroanatomy. We investigated alteration in covariance of structural networks associated with PTSD in regions that demonstrate the case-control differences in cortical thickness (CT) and surface area (SA). METHODS: Neuroimaging and clinical data were aggregated from 29 research sites in >1,300 PTSD cases and >2,000 trauma-exposed controls (age 6.2-85.2 years) by the ENIGMA-PGC PTSD working group. Cortical regions in the network were rank-ordered by effect size of PTSD-related cortical differences in CT and SA. The top-n (n = 2 to 148) regions with the largest effect size for PTSD > non-PTSD formed hypertrophic networks, the largest effect size for PTSD < non-PTSD formed atrophic networks, and the smallest effect size of between-group differences formed stable networks. The mean structural covariance (SC) of a given n-region network was the average of all positive pairwise correlations and was compared to the mean SC of 5,000 randomly generated n-region networks. RESULTS: Patients with PTSD, relative to non-PTSD controls, exhibited lower mean SC in CT-based and SA-based atrophic networks. Comorbid depression, sex and age modulated covariance differences of PTSD-related structural networks. CONCLUSIONS: Covariance of structural networks based on CT and cortical SA are affected by PTSD and further modulated by comorbid depression, sex, and age. The structural covariance networks that are perturbed in PTSD comport with converging evidence from resting state functional connectivity networks and networks impacted by inflammatory processes, and stress hormones in PTSD
A Comparison of Methods to Harmonize Cortical Thickness Measurements Across Scanners and Sites
Results of neuroimaging datasets aggregated from multiple sites may be biased by site-specific profiles in participants’ demographic and clinical characteristics, as well as MRI acquisition protocols and scanning platforms. We compared the impact of four different harmonization methods on results obtained from analyses of cortical thickness data: (1) linear mixed-effects model (LME) that models site-specific random intercepts (LME INT), (2) LME that models both site-specific random intercepts and age-related random slopes (LME INT+SLP), (3) ComBat, and (4) ComBat with a generalized additive model (ComBat-GAM). Our test case for comparing harmonization methods was cortical thickness data aggregated from 29 sites, which included 1,340 cases with posttraumatic stress disorder (PTSD) (6.2–81.8 years old) and 2,057 trauma-exposed controls without PTSD (6.3–85.2 years old). We found that, compared to the other data harmonization methods, data processed with ComBat-GAM was more sensitive to the detection of significant case-control differences (Χ 2(3) = 63.704, p < 0.001) as well as case-control differences in age-related cortical thinning (Χ 2(3) = 12.082, p = 0.007). Both ComBat and ComBat-GAM outperformed LME methods in detecting sex differences (Χ 2(3) = 9.114, p = 0.028) in regional cortical thickness. ComBat-GAM also led to stronger estimates of age-related declines in cortical thickness (corrected p-values < 0.001), stronger estimates of case-related cortical thickness reduction (corrected p-values < 0.001), weaker estimates of age-related declines in cortical thickness in cases than controls (corrected p-values < 0.001), stronger estimates of cortical thickness reduction in females than males (corrected p-values < 0.001), and stronger estimates of cortical thickness reduction in females relative to males in cases than controls (corrected p-values < 0.001). Our results support the use of ComBat-GAM to minimize confounds and increase statistical power when harmonizing data with non-linear effects, and the use of either ComBat or ComBat-GAM for harmonizing data with linear effects
New loci for body fat percentage reveal link between adiposity and cardiometabolic disease risk
To increase our understanding of the genetic basis of adiposity and its links to cardiometabolic disease risk, we conducted a genome-wide association meta-analysis of body fat percentage (BF%) in up to 100,716 individuals. Twelve loci reached genome-wide significance (P<5 × 10−8), of which eight were previously associated with increased overall adiposity (BMI, BF%) and four (in or near COBLL1/GRB14, IGF2BP1, PLA2G6, CRTC1) were novel associations with BF%. Seven loci showed a larger effect on BF% than on BMI, suggestive of a primary association with adiposity, while five loci showed larger effects on BMI than on BF%, suggesting association with both fat and lean mass. In particular, the loci more strongly associated with BF% showed distinct cross-phenotype association signatures with a range of cardiometabolic traits revealing new insights in the link between adiposity and disease risk
Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity.
Global dispersal and increasing frequency of the SARS-CoV-2 spike protein variant D614G are suggestive of a selective advantage but may also be due to a random founder effect. We investigate the hypothesis for positive selection of spike D614G in the United Kingdom using more than 25,000 whole genome SARS-CoV-2 sequences. Despite the availability of a large dataset, well represented by both spike 614 variants, not all approaches showed a conclusive signal of positive selection. Population genetic analysis indicates that 614G increases in frequency relative to 614D in a manner consistent with a selective advantage. We do not find any indication that patients infected with the spike 614G variant have higher COVID-19 mortality or clinical severity, but 614G is associated with higher viral load and younger age of patients. Significant differences in growth and size of 614G phylogenetic clusters indicate a need for continued study of this variant
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