9,159 research outputs found
Microbial diversity in the thermal springs within Hot Springs National Park
The thermal water systems of Hot Springs National Park (HSNP) in Hot Springs, Arkansas exist in relative isolation from other North American thermal systems. The HSNP waters could therefore serve as a unique center of thermophilic microbial biodiversity. However, these springs remain largely unexplored using culture-independent next generation sequencing techniques to classify species of thermophilic organisms. Additionally, HSNP has been the focus of anthropogenic development, capping and diverting the springs for use in recreational bathhouse facilities. Human modification of these springs may have impacted the structure of these bacterial communities compared to springs left in a relative natural state. The goal of this study was to compare the community structure in two capped springs and two uncapped springs in HSNP, as well as broadly survey the microbial diversity of the springs. We used Illumina 16S rRNA sequencing of water samples from each spring, the QIIME workflow for sequence analysis, and generated measures of genera and phyla richness, diversity, and evenness. In total, over 700 genera were detected and most individual samples had more than 100 genera. There were also several uncharacterized sequences that could not be placed in known taxa, indicating the sampled springs contain undescribed bacteria. There was great variation both between sites and within samples, so no significant differences were detected in community structure between sites. Our results suggest that these springs, regardless of their human modification, contain a considerable amount of biodiversity, some of it potentially unique to the study site
Improved Workflow for Unsupervised Multiphase Image Segmentation
Quantitative image analysis often depends on accurate classification of
pixels through a segmentation process. However, imaging artifacts such as the
partial volume effect and sensor noise complicate the classification process.
These effects increase the pixel intensity variance of each constituent class,
causing intensities from one class to overlap with another. This increased
variance makes threshold based segmentation methods insufficient due to
ambiguous overlap regions in the pixel intensity distributions. The class
ambiguity becomes even more complex for systems with more than two
constituents, such as unsaturated moist granular media. In this paper, we
propose an image processing workflow that improves segmentation accuracy for
multiphase systems. First, the ambiguous transition regions between classes are
identified and removed, which allows for global thresholding of single-class
regions. Then the transition regions are classified using a distance function,
and finally both segmentations are combined into one classified image. This
workflow includes three methodologies for identifying transition pixels and we
demonstrate on a variety of synthetic images that these approaches are able to
accurately separate the ambiguous transition pixels from the single-class
regions. For situations with typical amounts of image noise, misclassification
errors and area differences calculated between each class of the synthetic
images and the resultant segmented images range from 0.69-1.48% and 0.01-0.74%,
respectively, showing the segmentation accuracy of this approach. We
demonstrate that we are able to accurately segment x-ray microtomography images
of moist granular media using these computationally efficient methodologies
Suppression of allergic airway inflammation by helminth-induced regulatory T cells
Allergic diseases mediated by T helper type (Th) 2 cell immune responses are rising dramatically in most developed countries. Exaggerated Th2 cell reactivity could result, for example, from diminished exposure to Th1 cell–inducing microbial infections. Epidemiological studies, however, indicate that Th2 cell–stimulating helminth parasites may also counteract allergies, possibly by generating regulatory T cells which suppress both Th1 and Th2 arms of immunity. We therefore tested the ability of the Th2 cell–inducing gastrointestinal nematode Heligmosomoides polygyrus to influence experimentally induced airway allergy to ovalbumin and the house dust mite allergen Der p 1. Inflammatory cell infiltrates in the lung were suppressed in infected mice compared with uninfected controls. Suppression was reversed in mice treated with antibodies to CD25. Most notably, suppression was transferable with mesenteric lymph node cells (MLNC) from infected animals to uninfected sensitized mice, demonstrating that the effector phase was targeted. MLNC from infected animals contained elevated numbers of CD4(+)CD25(+)Foxp3(+) T cells, higher TGF-β expression, and produced strong interleukin (IL)-10 responses to parasite antigen. However, MLNC from IL-10–deficient animals transferred suppression to sensitized hosts, indicating that IL-10 is not the primary modulator of the allergic response. Suppression was associated with CD4(+) T cells from MLNC, with the CD4(+)CD25(+) marker defining the most active population. These data support the contention that helminth infections elicit a regulatory T cell population able to down-regulate allergen induced lung pathology in vivo
New insight into the molecular control of bacterial functional amyloids.
New insight into the molecular control of bacterial functional amyloids. Front. Cell. Infect. Microbiol. 5:33. doi: 10.3389/fcimb.2015.00033 New insight into the molecular control of bacterial functional amyloid
Ultralow phase noise microwave generation with an Er:fiber-based optical frequency divider
We present an optical frequency divider based on a 200 MHz repetition rate
Er:fiber mode-locked laser that, when locked to a stable optical frequency
reference, generates microwave signals with absolute phase noise that is equal
to or better than cryogenic microwave oscillators. At 1 Hz offset from a 10 GHz
carrier, the phase noise is below -100 dBc/Hz, limited by the optical
reference. For offset frequencies > 10 kHz, the phase noise is shot noise
limited at -145 dBc/Hz. An analysis of the contribution of the residual noise
from the Er:fiber optical frequency divider is also presented.Comment: 4 pages, 3 figure
EXOGEN ultrasound bone healing system for long bone fractures with non-union or delayed healing: a NICE medical technology guidance
Open Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.This article has been made available through the Brunel Open Access Publishing Fund.A routine part of the process for developing National Institute for Health and Care Excellence (NICE) medical technologies guidance is a submission of clinical and economic evidence by the technology manufacturer. The Birmingham and Brunel Consortium External Assessment Centre (EAC; a consortium of the University of Birmingham and Brunel University) independently appraised the submission on the EXOGEN bone healing system for long bone fractures with non-union or delayed healing. This article is an overview of the original evidence submitted, the EAC’s findings, and the final NICE guidance issued.The Birmingham and Brunel Consortium is funded by NICE to act as an External Assessment Centre for the Medical Technologies Evaluation Programme
Ultrafast, high repetition rate, ultraviolet, fiber based laser source: application towards Yb+ fast quantum-logic
Trapped ions are one of the most promising approaches for the realization of
a universal quantum computer. Faster quantum logic gates could dramatically
improve the performance of trapped-ion quantum computers, and require the
development of suitable high repetition rate pulsed lasers. Here we report on a
robust frequency upconverted fiber laser based source, able to deliver 2.5 ps
ultraviolet (UV) pulses at a stabilized repetition rate of 300.00000 MHz with
an average power of 190 mW. The laser wavelength is resonant with the strong
transition in Ytterbium (Yb+) at 369.53 nm and its repetition rate can be
scaled up using high harmonic mode locking. We show that our source can produce
arbitrary pulse patterns using a programmable pulse pattern generator and fast
modulating components. Finally, simulations demonstrate that our laser is
capable of performing resonant, temperature-insensitive, two-qubit quantum
logic gates on trapped Yb ions faster than the trap period and with
fidelity above 99%
Constituting monetary conservatives via the 'savings habit': New Labour and the British housing market bubble
The ongoing world credit crunch might well kill off the most recent bubble dynamics in the British housing market by driving prices systematically downwards from their 2007 peak. Nonetheless, the experience of that bubble still warrants analytical attention. The Labour Government might not have been responsible for consciously creating it, but it has certainly grasped the opportunities the bubble has provided in an attempt to enforce a process of agential change at the heart of the British economy. The key issue in this respect is the way in which the Government has challenged the legitimacy of passive welfare receipts in favour of establishing a welfare system based on incorporating the individual into an active asset-holding society. The housing market has taken on new political significance as a means for individuals first to acquire assets and then to accumulate wealth on the back of asset ownership. The ensuing integration of the housing market into an increasingly reconfigured welfare system has permeated into the politics of everyday life. It has been consistent with individuals remaking their political subjectivities in line with preferences for the type of conservative monetary policies that typically keep house price bubbles inflated
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