2,879 research outputs found
Nanostructured Vanadium Oxide Uncooled Bolometers and Method of Fabrication
The present invention relates to uncooled microbolometers which can be integrated in future thermal instruments engaged in land imaging on future observatories. The present invention includes: (1) developing and characterizing a microstructured VOx thin film, and, (2) fabricating an uncooled microbolometer array over the 8-14 micron spectral band
When trees grow too long: Investigating the causes of highly inaccurate bayesian branch-length estimates
A surprising number of recent Bayesian phylogenetic analyses contain branch-length estimates that are several orders of magnitude longer than corresponding maximum-likelihood estimates. The levels of divergence implied by such branch lengths are unreasonable for studies using biological data and are known to be false for studies using simulated data. We conducted additional Bayesian analyses and studied approximate-posterior surfaces to investigate the causes underlying these large errors. We manipulated the starting parameter values of the Markov chain Monte Carlo (MCMC) analyses, the moves used by the MCMC analyses, and the prior-probability distribution on branch lengths. We demonstrate that inaccurate branch-length estimates result from either 1) poor mixing of MCMC chains or 2) posterior distributions with excessive weight at long tree lengths. Both effects are caused by a rapid increase in the volume of branch-length space as branches become longer. In the former case, both an MCMC move that scales all branch lengths in the tree simultaneously and the use of overdispersed starting branch lengths allow the chain to accurately sample the posterior distribution and should be used in Bayesian analyses of phylogeny. In the latter case, branch-length priors can have strong effects on resulting inferences and should be carefully chosen to reflect biological expectations. We provide a formula to calculate an exponential rate parameter for the branch-length prior that should eliminate inference of biased branch lengths in many cases. In any phylogenetic analysis, the biological plausibility of branch-length output must be carefully considered
Leukocytoclastic Vasculitis in a 66-Year-Old Woman After Fusion of the Second Right Metatarsocuneiform Joint Using Titanium Plate and Screws: A Case Report
Metallic orthopaedic implants are known to instigate cutaneous reactions; however, the mechanism by which this occurs is not fully understood. Contact dermatitis after implantation of stainless steel fracture plates was first described in 1966, and similar reactions to various implants have been documented subsequently. Leukocytoclastic vasculitis (LCV) is an inflammatory condition of small dermal blood vessels resulting from neutrophil invasion, degranulation, and cell death caused by a type III hypersensitivity reaction. No studies have reported use of titanium orthopaedic implants resulting in LCV. We describe a 66-year-old woman who developed LCV after the fusion of her second right metatarsocuneiform joint with a titanium plate and screws. At 4 months after removal of the titanium plate and screws, the LCV symptoms had resolved without further intervention. Although this rash might be a rare complication associated with orthopaedic implants, it is an important differential diagnosis for orthopaedic surgeons to consider when assessing and treating postoperative rashes
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Measles vaccination and antibody response in autism spectrum disorder
OBJECTIVE: To test the hypothesis that measles vaccination was involved in the pathogenesis of autism spectrum disorders (ASD) as evidenced by signs of a persistent measles infection or abnormally persistent immune response shown by circulating measles virus or raised antibody titres in children with ASD who had been vaccinated against measles, mumps and rubella (MMR) compared with controls. DESIGN: Case-control study, community based. METHODS: A community sample of vaccinated children aged 10-12 years in the UK with ASD (n = 98) and two control groups of similar age, one with special educational needs but no ASD (n = 52) and one typically developing group (n = 90), were tested for measles virus and antibody response to measles in the serum. RESULTS: No difference was found between cases and controls for measles antibody response. There was no dose-response relationship between autism symptoms and antibody concentrations. Measles virus nucleic acid was amplified by reverse transcriptase-PCR in peripheral blood mononuclear cells from one patient with autism and two typically developing children. There was no evidence of a differential response to measles virus or the measles component of the MMR in children with ASD, with or without regression, and controls who had either one or two doses of MMR. Only one child from the control group had clinical symptoms of possible enterocolitis. CONCLUSION: No association between measles vaccination and ASD was shown
Microscopic crystallographic analysis of dislocations in molecular crystals
Organic molecular crystals encompass a vast range of materials from
pharmaceuticals to organic optoelectronics and proteins to waxes in biological
and industrial settings. Crystal defects from grain boundaries to dislocations
are known to play key roles in mechanisms of growth and also in the functional
properties of molecular crystals. In contrast to the precise analysis of
individual defects in metals, ceramics, and inorganic semiconductors enabled by
electron microscopy, significantly greater ambiguity remains in the
experimental determination of individual dislocation character and slip systems
in molecular materials. In large part, nanoscale dislocation analysis in
molecular crystals has been hindered by the severely constrained electron
exposures required to avoid irreversibly degrading these crystals. Here, we
present a low-dose, single-exposure approach enabling nanometre-resolved
analysis of individual extended dislocations in molecular crystals. We
demonstrate the approach for a range of crystal types to reveal dislocation
character and operative slip systems unambiguously.Comment: Manuscript (14 pages, 4 figures) and Supplementary Material (32
pages, 19 figures) in a single PDF fil
Verbal Compliments As a Differential Source of Mate Poaching Threat For Men and Women
Two studies tested whether people feel threatened by another individual verbally complimenting their romantic partner. Such compliments may indicate that the other person is a potential rival who will try to poach their mate. Across two studies, women were more threatened than men when imagining another person complimenting their partner\u27s physical appearance. There were no sex differences in response to imagining another person complimenting their partner\u27s sense of humor. When another person compliments one\u27s partner\u27s physical appearance, this indicates that they may be sexually attracted to the partner. Mediation analyses revealed that the sex difference occurs because women believe men are more open to casual sex, and therefore more vulnerable to mate poaching when another person expresses sexual interest in them
Multicentury Fire and Forest Histories at 19 Sites in Utah and Eastern Nevada
Our objective is to provide site-specific fire and forest histories from Utah and eastern Nevada that can be used for land management or additional research. We systematically sampled fire scars and tree-recruitment dates across broad gradients in elevation and forest type at 13 sites in Utah and 1 in eastern Nevada to characterize spatial and temporal variation in historical fire regimes as well as forest structure and composition. We collected similar data non-systematically at five additional sites in Utah. These 19 sites include a broad range of forest types (from pinyon-juniper woodlands to spruce-fir forests) and fire regime types. In this report, we summarize local-scale spatial and temporal variation with site-specific details of historical fire regimes and forests that will be useful for local natural resource and fire management of the individual sites. For each site, we report topography, chronologies of fire and tree recruitment, and properties derived from those chronologies such as time-averaged fire regime parameters (mean fire interval and fire severity) and changes in forest composition and structure that have occurred since the late 1800s
NMR elastometry of fluid membranes in the mesoscopic regime
In solid-state 2H NMR of fluid lipid bilayers, quasielastic deformations at MHz frequencies are detected as a square-law dependence of the nuclear spin-lattice (R1Z) relaxation rates and order parameters (SCD). The signature square-law slope is found to decrease progressively with the mole fraction of cholesterol and with the acyl chain length, due to a stiffening of the membrane. The correspondence to thermal vesicle fluctuations and molecular dynamics simulations implies that a broad distribution of modes is present, ranging from the membrane size down to the molecular dimensions
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The peripheral blood transcriptome in septic cardiomyopathy: an observational, pilot study.
BACKGROUND:Septic cardiomyopathy (SCM) is common in sepsis and associated with increased morbidity and mortality. Left ventricular global longitudinal strain (LV GLS), measured by speckle tracking echocardiography, allows improved identification of impaired cardiac contractility. The peripheral blood transcriptome may be an important window into SCM pathophysiology. We therefore studied the peripheral blood transcriptome and LV GLS in a prospective cohort of patients with sepsis. RESULTS:In this single-center observational pilot study, we enrolled adult patients (age > 18) with sepsis within 48 h of admission to the ICU. SCM was defined as LV GLS > - 17% based on echocardiograms performed within 72 h of admission. We enrolled 27 patients, 24 of whom had high-quality RNA results; 18 (75%) of 24 had SCM. The group was 50% female and had a median (IQR) age of 59.5 (48.5-67.0) years and admission APACHE II score of 21.0 (16.0-32.3). Forty-six percent had septic shock. After filtering for low-expression and non-coding genes, 15,418 protein coding genes were expressed and 73 had significantly different expression between patients with vs. without SCM. In patients with SCM, 43 genes were upregulated and 30 were downregulated. Pathway analysis identified enrichment in type 1 interferon signaling (adjusted p < 10-5). CONCLUSIONS:In this hypothesis-generating study, SCM was associated with upregulation of genes in the type 1 interferon signaling pathway. Interferons are cytokines that stimulate the innate and adaptive immune response and are implicated in the early proinflammatory and delayed immunosuppression phases of sepsis. While type 1 interferons have not been implicated previously in SCM, interferon therapy (for viral hepatitis and Kaposi sarcoma) has been associated with reversible cardiomyopathy, perhaps suggesting a role for interferon signaling in SCM
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