1,207 research outputs found
Susceptibility to intestinal infection and diarrhoea in Zambian adults in relation to HIV status and CD4 count.
BACKGROUND: The HIV epidemic in sub-Saharan Africa has had a major impact on infectious disease, and there is currently great interest in the impact of HIV on intestinal barrier function. A three year longitudinal cohort study in a shanty compound in Lusaka, Zambia, carried out before anti-retroviral therapy was widely available, was used to assess the impact of HIV on susceptibility to intestinal infectious disease. We measured the incidence and seasonality of intestinal infection and diarrhoea, aggregation of disease in susceptible individuals, clustering by co-habitation and genetic relatedness, and the disease-to-infection ratio. METHODS: Adults living in a small section of Misisi, Lusaka, were interviewed every two weeks to ascertain the incidence of diarrhoea. Monthly stool samples were analysed for selected pathogens. HIV status and CD4 count were determined annually. RESULTS: HIV seroprevalence was 31% and the prevalence of immunosuppression (CD4 count 200 cells/microL or less) was 10%. Diarrhoea incidence was 1.1 episodes per year and the Incidence Rate Ratio for HIV infection was 2.4 (95%CI 1.7-3.3; p < 0.001). The disease-to-infection ratio was increased at all stages of HIV infection. Aggregation of diarrhoea in susceptible individuals was observed irrespective of immunosuppression, but there was little evidence of clustering by co-habitation or genetic relatedness. There was no evidence of aggregation of asymptomatic infections. CONCLUSION: HIV has an impact on intestinal infection at all stages, with an increased disease-to-infection ratio. The aggregation of disease in susceptible individuals irrespective of CD4 count suggests that this phenomenon is not a function of cell mediated immunity
High-grade urothelial carcinoma with squamous differentiation metastasizing to the tongue.
Tumors metastasizing to the head and neck region are uncommon. Metastasis of urothelial carcinoma to the maxillofacial region is exceedingly rare and mostly involves the jaw. We present a case of urothelial carcinoma metastasizing to the tongue. Immunohistochemistry in conjunction with fluorescent in situ hybridization was used to confirm the relation between the primary and metastatic lesions, making it the first such reported case employing the UroVysion (Catalogue number 02 J27-025, Abbott Molecular Inc., Des Plaines, IL, USA) fluorescent in situ hybridization probe in a metastatic lesion in the head and neck region
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A performance evaluation framework for building fault detection and diagnosis algorithms
Fault detection and diagnosis (FDD) algorithms for building systems and equipment represent one of the most active areas of research and commercial product development in the buildings industry. However, far more effort has gone into developing these algorithms than into assessing their performance. As a result, considerable uncertainties remain regarding the accuracy and effectiveness of both research-grade FDD algorithms and commercial products—a state of affairs that has hindered the broad adoption of FDD tools. This article presents a general, systematic framework for evaluating the performance of FDD algorithms. The article focuses on understanding the possible answers to two key questions: in the context of FDD algorithm evaluation, what defines a fault and what defines an evaluation input sample? The answers to these questions, together with appropriate performance metrics, may be used to fully specify evaluation procedures for FDD algorithms
Phase I safety trial of intravenous ascorbic acid in patients with severe sepsis
Background Parenterally administered ascorbic acid modulates sepsis-induced inflammation and coagulation in experimental animal models. The objective of this randomized, double-blind, placebo-controlled, phase I trial was to determine the safety of intravenously infused ascorbic acid in patients with severe sepsis.
Methods Twenty-four patients with severe sepsis in the medical intensive care unit were randomized 1:1:1 to receive intravenous infusions every six hours for four days of ascorbic acid: Lo-AscA (50 mg/kg/24 h, n = 8), or Hi-AscA (200 mg/kg/24 h, n = 8), or Placebo (5% dextrose/water, n = 8). The primary end points were ascorbic acid safety and tolerability, assessed as treatment-related adverse-event frequency and severity. Patients were monitored for worsened arterial hypotension, tachycardia, hypernatremia, and nausea or vomiting. In addition Sequential Organ Failure Assessment (SOFA) scores and plasma levels of ascorbic acid, C-reactive protein, procalcitonin, and thrombomodulin were monitored.
Results Mean plasma ascorbic acid levels at entry for the entire cohort were 17.9 ± 2.4 μM (normal range 50-70 μM). Ascorbic acid infusion rapidly and significantly increased plasma ascorbic acid levels. No adverse safety events were observed in ascorbic acid-infused patients. Patients receiving ascorbic acid exhibited prompt reductions in SOFA scores while placebo patients exhibited no such reduction. Ascorbic acid significantly reduced the proinflammatory biomarkers C-reactive protein and procalcitonin. Unlike placebo patients, thrombomodulin in ascorbic acid infused patients exhibited no significant rise, suggesting attenuation of vascular endothelial injury.
Conclusions Intravenous ascorbic acid infusion was safe and well tolerated in this study and may positively impact the extent of multiple organ failure and biomarkers of inflammation and endothelial injury
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The effects of diesel exhaust pollution on floral volatiles and the consequences for honey bee olfaction
There is growing evidence of a substantial decline in pollinators within Europe and North America, most likely caused by multiple factors such as diseases, poor nutrition, habitat loss, insecticides, and environmental pollution. Diesel exhaust could be a contributing factor to this decline, since we found that diesel exhaust rapidly degrades floral volatiles, which honey bees require for flower recognition. In this study, we exposed eight of the most common floral volatiles to diesel exhaust in order to investigate whether it can affect volatile mediated plant-pollinator interaction. Exposure to diesel exhaust altered the blend of common flower volatiles significantly: myrcene was considerably reduced, β-ocimene became undetectable, and β-caryophyllene was transformed into its cis-isomer isocaryophyllene. Proboscis extension response (PER) assays showed that the alterations of the blend reduced the ability of honey bees to recognize it. The chemically reactive nitrogen oxides fraction of diesel exhaust gas was identified as capable of causing degradation of floral volatiles
Blending Bathymetry: Combination of image-derived parametric approximations and celerity data sets for nearshore bathymetry estimation
Estimation of nearshore bathymetry is important for accurate prediction of
nearshore wave conditions. However, direct data collection is expensive and
time-consuming while accurate airborne lidar-based survey is limited by
breaking waves and decreased light penetration affected by water turbidity.
Instead, tower-based platforms or Unmanned Aircraft System (UAS) can provide
indirect video-based observations. The video-based time-series imagery provides
wave celerity information and time-averaged (timex) or variance enhanced (var)
images identify persistent regions of wave breaking.
In this work, we propose a rapid and improved bathymetry estimation method
that takes advantage of image-derived wave celerity and a first-order
bathymetry estimate from Parameter Beach Tool (PBT), software that fits
parameterized sandbar and slope forms to the timex or var images. Two different
sources of the data, PBT and wave celerity, are combined or blended optimally
based on their assumed accuracy in a statistical framework. The PBT-derived
bathymetry serves as "prior" coarse-scale background information and then is
updated and corrected with the imagery-derived wave data through the dispersion
relationship, which results in a better bathymetry estimate that is consistent
with imagery-based wave data. To illustrate the accuracy of our proposed
method, imagery data sets collected in 2017 at the US Army EDRC's Field
Research Facility in Duck, NC under different weather and wave height
conditions are tested. Estimated bathymetry profiles are remarkably close to
the direct survey data. The computational time for the estimation from
PBT-based bathymetry and imagery-derived wave celerity is only about five
minutes on a free Google Cloud node with one CPU core. These promising results
indicate the feasibility of reliable real-time bathymetry imaging during a
single flight of UAS.Comment: 21 pages, 14 figures, preprint
High Force Unimanual Handgrip Contractions Increase Ipsilateral Sensorimotor Activation and Functional Connectivity
Imaging and brain stimulation studies seem to correct the classical understanding of how brain networks, rather than contralateral focal areas, control the generation of unimanual voluntary force. However, the scaling and hemispheric-specificity of network activation remain less understood. Using fMRI, we examined the effects of parametrically increasing right-handgrip force on activation and functional connectivity among the sensorimotor network bilaterally with 25%, 50%, and 75% maximal voluntary contractions (MVC). High force (75% MVC) unimanual handgrip contractions resulted in greater ipsilateral motor activation and functional connectivity with the contralateral hemisphere compared to a low force 25% MVC condition. The ipsilateral motor cortex activation and network strength correlated with relative handgrip force (% MVC). Increases in unimanual handgrip force resulted in greater ipsilateral sensorimotor activation and greater functional connectivity between hemispheres within the sensorimotor network. (C) 2020 IBRO. Published by Elsevier Ltd. All rights reserved
RSAT™ process development for post-combustion CO2 capture: Scale-up from laboratory and pilot test data to commercial process design
AbstractIt is believed that a RSAT™ (Regenerable Solvent Absorption Technology) process is the most viable nearterm technology for post-combustion CO2 capture from power plant flue gas. The Babcock & Wilcox Power Generation Group, Inc. (B&W) has deployed a suite of research tools to evaluate and develop the CO2 scrubbing technology, including laboratory, pilot-scale, and simulation modeling capabilities. Since the construction and operation of test facilities require significant resources, it is essential to effectively utilize these research tools by choosing a scale-up approach which provides robust design data for a commercial process while minimizing the amount of experimentation required.The scale-up protocol used for RSAT CO2 scrubbing processes was rigorously developed using rate-based modeling concurrent with acquiring fundamental laboratory and pilot plant data for process validation. These development activities were not conducted in series but rather overlapped to yield an optimized commercial CO2 scrubbing process in a reasonable time frame with a high degree of design confidence [1,2].This paper presents the scale-up protocol used in evaluating the RSAT process which encompasses both laboratory and pilot-scale testing as well as rate-based modeling to achieve a commercial-scale RSAT process design. This document demonstrates the qualification of test data from a packed tower scale-up point of view. Solvent screening research activities recently conducted within B&W successfully demonstrate the scale-up protocol used for RSAT process development. The time and cost of process development can be significantly reduced through rigorous rate-based modeling in conjunction with laboratory experiments and pilot plant validation
Wavelets and graph -algebras
Here we give an overview on the connection between wavelet theory and
representation theory for graph -algebras, including the higher-rank
graph -algebras of A. Kumjian and D. Pask. Many authors have studied
different aspects of this connection over the last 20 years, and we begin this
paper with a survey of the known results. We then discuss several new ways to
generalize these results and obtain wavelets associated to representations of
higher-rank graphs. In \cite{FGKP}, we introduced the "cubical wavelets"
associated to a higher-rank graph. Here, we generalize this construction to
build wavelets of arbitrary shapes. We also present a different but related
construction of wavelets associated to a higher-rank graph, which we anticipate
will have applications to traffic analysis on networks. Finally, we generalize
the spectral graph wavelets of \cite{hammond} to higher-rank graphs, giving a
third family of wavelets associated to higher-rank graphs
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Concept selection for advanced low-emission coal fired boiler
The Babcock & Wilcox Company (B&W), under contract to the US Department of Energy (DOE) with subcontract to Physical Sciences, Inc. (PSIT), the Massachusetts Institute of Technology (MIT) and United Engineers and Constructors (UE&C) has begun development of an advanced low-emission boiler system (LEBS). The initial phase of this multi-phase program required a thorough review and assessment of potential advanced technologies and techniques for control of combustion and flue gas emissions. Results of this assessment are presented in this paper
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