304 research outputs found
Genomic sequence of Campylobacter jejuni subsp. jejuni HS:19 Penner serotype reference strain RM3420
Campylobacter jejuni subsp. jejuni infections are a leading cause of foodborne gastroenteritis and the most prevalent antecedent to Guillain-Barré syndrome (GBS). Penner serotype HS:19 is among several capsular types shown to be markers for GBS. This study describes the genome of C. jejuni subsp. jejuni HS:19 Penner reference strain RM3420
Complete genomic sequence of Campylobacter jejuni subsp. jejuni HS: 19 strain RM1285 isolated from packaged chicken
Poultry products serve as the main source of Campylobacter jejuni subsp. jejuni infections in humans. C. jejuni subsp. jejuni infections are a leading cause of foodborne gastroenteritis and are a prevalent antecedent to Guillain-Barré syndrome. This study describes the genome of C. jejuni subsp. jejuni HS:19 strain RM1285, isolated from packaged chicken in California
Identification of a system required for the functional surface localization of sugar binding proteins with class III signal peptides in Sulfolobus solfataricus
The hyperthermophilic archaeon Sulfolobus solfataricus contains an unusual large number of sugar binding proteins that are synthesized as precursors with a class III signal peptide. Such signal peptides are commonly used to direct archaeal flagellin subunits or bacterial (pseudo)pilins into extracellular macromolecular surface appendages. Likewise, S. solfataricus binding proteins have been suggested to assemble in higher ordered surface structures as well, tentatively termed the bindosome. Here we show that S. solfataricus contains a specific system that is needed for the functional surface localization of sugar binding proteins. This system, encoded by the bas (bindosome assembly system) operon, is composed of five proteins: basABC, three homologues of so-called bacterial (pseudo)pilins; BasE, a cytoplasmic ATPase; and BasF, an integral membrane protein. Deletion of either the three (pseudo)pilin genes or the basEF genes resulted in a severe defect of the cells to grow on substrates which are transported by sugar binding proteins containing class III signal peptides, while growth on glucose and maltose was restored when the corresponding genes were reintroduced in these cells. Concomitantly, ΔbasABC and ΔbasEF cells were severely impaired in glucose uptake even though the sugar binding proteins were normally secreted across the cytoplasmic membrane. These data underline the hypothesis that the bas operon is involved in the functional localization of sugar binding proteins at the cell surface of S. solfataricus. In contrast to surface structure assembly systems of Gram-negative bacteria, the bas operon seems to resemble an ancestral simplified form of these machineries.
Complete genome sequences of Campylobacter jejuni strains RM3196 (233.94) and RM3197 (308.95) isolated from patients with Guillain-Barré syndrome
Infections with Campylobacter jejuni subsp. jejuni are a leading cause of foodborne gastroenteritis and the most prevalent infection preceding Guillain-Barré syndrome (GBS). This study describes the genomes of C. jejuni subsp. jejuni HS:41 strains RM3196 (233.94) and RM3197 (308.95) that were isolated from patients with GBS in Cape Town, South Africa
Electroluminescence enhancement in mid-infrared InAsSb resonant cavity light emitting diodes for CO 2 detection
In this work, we demonstrated a mid-infrared resonant cavity light emitting diode (RCLED) operating near 4.2 μm at room temperature, grown lattice-matched on a GaSb substrate by molecular beam epitaxy, suitable for CO 2 gas detection. The device consists of a 1 λ-thick microcavity containing an InAs 0.90 Sb 0.1 active region sandwiched between two high contrast, lattice-matched AlAs 0.08 Sb 0.92 /GaSb distributed Bragg reflector (DBR) mirrors. The electroluminescence emission spectra of the RCLED were recorded over the temperature range from 20 to 300 K and compared with a reference LED without DBR mirrors. The RCLED exhibits a strong emission enhancement due to resonant cavity effects. At room temperature, the peak emission and the integrated peak emission were found to be increased by a factor of ∼ 70 and ∼ 11, respectively, while the total integrated emission enhancement was ∼ × 33. This is the highest resonant cavity enhancement ever reported for a mid-infrared LED operating at this wavelength. Furthermore, the RCLED also exhibits a superior temperature stability of ∼ 0.35 nm/K and a significantly narrower (10×) spectral linewidth. High spectral brightness and temperature stable emission entirely within the fundamental absorption band are attractive characteristics for the development of next generation CO 2 gas sensor instrumentation. © 2019 Author(s)
Fredholm Determinants, Differential Equations and Matrix Models
Orthogonal polynomial random matrix models of NxN hermitian matrices lead to
Fredholm determinants of integral operators with kernel of the form (phi(x)
psi(y) - psi(x) phi(y))/x-y. This paper is concerned with the Fredholm
determinants of integral operators having kernel of this form and where the
underlying set is a union of open intervals. The emphasis is on the
determinants thought of as functions of the end-points of these intervals. We
show that these Fredholm determinants with kernels of the general form
described above are expressible in terms of solutions of systems of PDE's as
long as phi and psi satisfy a certain type of differentiation formula. There is
also an exponential variant of this analysis which includes the circular
ensembles of NxN unitary matrices.Comment: 34 pages, LaTeX using RevTeX 3.0 macros; last version changes only
the abstract and decreases length of typeset versio
Bomb-<sup>14</sup>C analysis of ecosystem respiration reveals that peatland vegetation facilitates release of old carbon
The largest terrestrial-to-atmosphere carbon flux is respired CO<sub>2</sub>. However, the partitioning of soil and plant sources, understanding of contributory mechanisms, and their response to climate change are uncertain. A plant removal experiment was established within a peatland located in the UK uplands to quantify respiration derived from recently fixed plant carbon and that derived from decomposition of soil organic matter, using natural abundance <sup>13</sup>C and bomb-<sup>14</sup>C as tracers. Soil and plant respiration sources were found respectively to contribute ~ 36% and between 41-54% of the total ecosystem CO<sub>2</sub> flux. Respired CO<sub>2</sub> produced in the clipped (‘soil’) plots had a mean age of ~ 15 years since fixation from the atmosphere, whereas the <sup>14</sup>C content of ecosystem CO<sub>2</sub> was statistically indistinguishable from the contemporary atmosphere. Results of carbon mass balance modelling showed that, in addition to respiration from bulk soil and plant respired CO<sub>2</sub>, a third, much older source of CO<sub>2</sub> existed. This source, which we suggest is CO<sub>2</sub> derived from the catotelm constituted between ~ 10 and 23% of total ecosystem respiration and had a mean radiocarbon age of between several hundred to ~ 2000 years before present (BP). These findings show that plant-mediated transport of CO<sub>2</sub> produced in the catotelm may form a considerable component of peatland ecosystem respiration. The implication of this discovery is that current assumptions in terrestrial carbon models need to be re-evaluated to consider the climate sensitivity of this third source of peatland CO<sub>2</sub>
Sensations of skin infestation linked to abnormal frontolimbic brain reactivity and differences in self-representation
Some patients experience skin sensations of infestation and contamination that are elusive to proximate dermatological explanation. We undertook a functional magnetic resonance imaging study of the brain to demonstrate, for the first time, that central processing of infestation-relevant stimuli is altered in patients with such abnormal skin sensations. We show differences in neural activity within amygdala, insula, middle temporal lobe and frontal cortices. Patients also demonstrated altered measures of self-representation, with poorer sensitivity to internal bodily (interoceptive) signals and greater susceptibility to take on an illusion of body ownership: the rubber hand illusion. Together, these findings highlight a potential model for the maintenance of abnormal skin sensations, encompassing heightened threat processing within amygdala, increased salience of skin representations within insula and compromised prefrontal capacity for self-regulation and appraisal
TFOS DEWS II Report Executive Summary
This article presents an Executive Summary of the conclusions and recommendations of the 10-chapter TFOS DEWS II report. The entire TFOS DEWS II report was published in the July 2017 issue of The Ocular Surface. A downloadable version of the document and additional material, including videos of diagnostic and management techniques, are available on the TFOS website: www.TearFilm.org
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