463 research outputs found
A Pair Polarimeter for Linearly Polarized High Energy Photons
A high quality beam of linearly polarized photons of several GeV will become
available with the coherent bremsstrahlung technique at JLab. We have developed
a polarimeter which requires about two meters of the beam line, has an
analyzing power of 20% and an efficiency of 0.02%. The layout and first results
of a polarimeter test on the laser back-scattering photon beam at SPring-8/LEPS
are presented
Population-based epidemiology of Escherichia coli ST1193 causing blood stream infections in a centralized Canadian region
Please read abstract in the article.The JPIAMR/Canadian Institute Health Research program.https://link.springer.com/journal/10096hj2023Medical Microbiolog
Population-based surveillance of Enterobacter cloacae complex causing blood stream infections in a centralized Canadian region
Active population-based surveillance determined clinical factors, susceptibility patterns, incidence rates (IR), and genomics among Enterobacter cloacae complex (n = 154) causing blood stream infections in a centralized Canadian region (2015–2017). The annual population IR was 1.2/100,000 (95% CI 0.9–16) in 2015, 1.4/100,000 (95% CI 1.1–1.9) in 2016, and 1.5/100,000 (95% CI 1.2–2.0) in 2017, affecting mainly elderly males with underlying comorbid conditions in the hospital setting. E. cloacae complex was dominated by polyclonal subspecies (i.e., E. hormaechei subsp. steigerwaltii, subsp. hoffmanni and subsp. xiangfangesis). Antimicrobial resistant determinants were rare. This study provided novel information about Enterobacter genomics in a well-defined human population.The Alberta Precision Laboratories.https://link.springer.com/journal/10096hj2023Medical Microbiolog
Extracting synaptic conductances from single membrane potential traces
In awake animals, the activity of the cerebral cortex is highly complex, with
neurons firing irregularly with apparent Poisson statistics. One way to
characterize this complexity is to take advantage of the high interconnectivity
of cerebral cortex and use intracellular recordings of cortical neurons, which
contain information about the activity of thousands of other cortical neurons.
Identifying the membrane potential (Vm) to a stochastic process enables the
extraction of important statistical signatures of this complex synaptic
activity. Typically, one estimates the total synaptic conductances (excitatory
and inhibitory) but this type of estimation requires at least two Vm levels and
therefore cannot be applied to single Vm traces. We propose here a method to
extract excitatory and inhibitory conductances (mean and variance) from single
Vm traces. This "VmT method" estimates conductance parameters using maximum
likelihood criteria, under the assumption are that synaptic conductances are
described by Gaussian stochastic processes and are integrated by a passive
leaky membrane. The method is illustrated using models and is tested on
guinea-pig visual cortex neurons in vitro using dynamic-clamp experiments. The
VmT method holds promises for extracting conductances from single-trial
measurements, which has a high potential for in vivo applications.Comment: Neuroscience (in press
The decline and conservation of bumblebees
Declines in bumblebee species in the last 60 years are well documented in Europe, where they are primarily driven by habitat loss and declines in floral abundance and diversity resulting from agricultural intensification. Impacts of habitat degradation and fragmentation are likely to be compounded by the social nature of bumblebees and their largely monogamous breeding system which renders their effective population size low. Hence populations are susceptible to stochastic extinction events and inbreeding. In North America, catastrophic declines of some bumblebee species since the 1990s are probably attributable to the accidental introduction of a non-native parasite from Europe, a result of global trade in domesticated bumblebee colonies used for pollination of greenhouse crops. Given the importance of bumblebees as pollinators of crops and wildflowers, it is vital that steps be taken to prevent further declines. Suggested measures include tight regulation of commercial bumblebee use and targeted use of agri-environment schemes to enhance floristic diversity in agricultural landscapes
The use of aortic balloon occlusion in traumatic shock : first report from the ABO trauma registry
Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a technique for temporary stabilization of patients with non-compressible torso hemorrhage. This technique has been increasingly used worldwide during the past decade. Despite the good outcomes of translational studies, clinical studies are divided. The aim of this multicenter-international study was to capture REBOA-specific data and outcomes. REBOA practicing centers were invited to join this online register, which was established in September 2014. REBOA cases were reported, both retrospective and prospective. Demographics, injury patterns, hemodynamic variables, REBOA-specific data, complications and 30-days mortality were reported. Ninety-six cases from 6 different countries were reported between 2011 and 2016. Mean age was 52 +/- 22 years and 88% of the cases were blunt trauma with a median injury severity score (ISS) of 41 (IQR 29-50). In the majority of the cases, Zone I REBOA was used. Median systolic blood pressure before balloon inflation was 60 mmHg (IQR 40-80), which increased to 100 mmHg (IQR 80-128) after inflation. Continuous occlusion was applied in 52% of the patients, and 48% received non-continuous occlusion. Occlusion time longer than 60 min was reported as 38 and 14% in the non-continuous and continuous groups, respectively. Complications, such as extremity compartment syndrome (n = 3), were only noted in the continuous occlusion group. The 30-day mortality for non-continuous REBOA was 48%, and 64% for continuous occlusion. This observational multicenter study presents results regarding continuous and non-continuous REBOA with favorable outcomes. However, further prospective studies are needed to be able to draw conclusions on morbidity and mortality.Peer reviewe
Genome-Wide Analysis of Subependymomas Shows Underlying Chromosomal Copy Number Changes Involving Chromosomes 6, 7, 8 and 14 in a Proportion of Cases
Subependymomas (SE) are slow-growing brain tumors that tend to occur within the ventricles of middle-aged and elderly adults. The World Health Organization classifies these tumors within the ependymoma group. Previous limited analysis of this tumor type had not revealed significant underlying cytogenetic abnormalities
The problem with dyes in infection control
Photoantimicrobial - i.e. light-activated - antimicrobial agents constitute a subset of compounds from a variety of dye classes, mainly synthetic. However, in terms of clinical acceptance, this identification as ‘dye’ is disadvantageous. The following is an attempt, via rationalisation and precedent, to put the case for the medical use of photoantimicrobials, at a time of an accepted need for alternative approaches to infection control, beside that of conventional antimicrobial drugs. Note: the term antibiotic is employed here with the everyday, rather than the scientific, meaning, i.e. rather than antibacterial. © 2017 Elsevier Lt
Proteins and esterase isozymes during developmental stages of organophosphate resistant strains in Anopheles stephensi liston
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