17 research outputs found
Isolation and Characterization of Salinivibrio sp. Strain LP-1 from an Impoundment Used for Marcellus Shale Waste Waters
A euryhalic, gram-negative, facultatively anaerobic bacterium was isolated from an enrichment culture found in an impoundment used for storing Marcellus Shale waste water. Designated strain LP-1, its cells were non-spore-forming, motile, curved rods with a single polar flagellum. Phylogenetic analysis using 16S rRNA gene sequences revealed it is a £^-proteobacerium closely related (98%) to Salinivibrio costicola. Carbohydrates serve as energy sources both aerobically and anaerobically. It grew anaerobically on nitrate with hydrogen, acetate, pyruvate, or lactate but not with formate, and did not use arsenate, sulfate, or thiosulfate as electron acceptors. Strain LP-1 grew optimally at 37°C (range 4-65°C), 10.0% NaCl (range 0-20.0%), and a pH of 7.5 (range 4.5-10.5). It is capable of forming pellicles in liquid culture and Strontium and Barium-containing precipitates. These results suggest that the recycling impoundments contain unique microbiota that have adapted to living in a broad range of conditions
Functional annotation of the transcriptome of Sorghum bicolor in response to osmotic stress and abscisic acid
<p>Abstract</p> <p>Background</p> <p>Higher plants exhibit remarkable phenotypic plasticity allowing them to adapt to an extensive range of environmental conditions. Sorghum is a cereal crop that exhibits exceptional tolerance to adverse conditions, in particular, water-limiting environments. This study utilized next generation sequencing (NGS) technology to examine the transcriptome of sorghum plants challenged with osmotic stress and exogenous abscisic acid (ABA) in order to elucidate genes and gene networks that contribute to sorghum's tolerance to water-limiting environments with a long-term aim of developing strategies to improve plant productivity under drought.</p> <p>Results</p> <p>RNA-Seq results revealed transcriptional activity of 28,335 unique genes from sorghum root and shoot tissues subjected to polyethylene glycol (PEG)-induced osmotic stress or exogenous ABA. Differential gene expression analyses in response to osmotic stress and ABA revealed a strong interplay among various metabolic pathways including abscisic acid and 13-lipoxygenase, salicylic acid, jasmonic acid, and plant defense pathways. Transcription factor analysis indicated that groups of genes may be co-regulated by similar regulatory sequences to which the expressed transcription factors bind. We successfully exploited the data presented here in conjunction with published transcriptome analyses for rice, maize, and Arabidopsis to discover more than 50 differentially expressed, drought-responsive gene orthologs for which no function had been previously ascribed.</p> <p>Conclusions</p> <p>The present study provides an initial assemblage of sorghum genes and gene networks regulated by osmotic stress and hormonal treatment. We are providing an RNA-Seq data set and an initial collection of transcription factors, which offer a preliminary look into the cascade of global gene expression patterns that arise in a drought tolerant crop subjected to abiotic stress. These resources will allow scientists to query gene expression and functional annotation in response to drought.</p
A reactive, scalable, and transferable model for molecular energies from a neural network approach based on local information
Despite the ever-increasing computer power, accurate ab initio calculations for large
systems (thousands to millions of atoms) remain infeasible. Instead, approximate em-
pirical energy functions are used. Most current approaches are either transferable
between different chemical systems, but not particularly accurate, or they are fine-
tuned to a specific application. In this work, a data-driven method to construct a
potential energy surface based on neural networks is presented. Since the total energy
is decomposed into local atomic contributions, the evaluation is easily parallelizable
and scales linearly with system size. With prediction errors below 0.5 kcal mol −1 for
both, unknown molecules and configurations, the method is accurate across chemical
and configurational space, which is demonstrated by applying it to data sets from
nonreactive and reactive molecular dynamics simulations and a diverse database of
equilibrium structures. The possibility to use small molecules as reference data to
predict larger structures is also explored. Since the descriptor only uses local informa-
tion, high-level ab initio methods, which are computationally too expensive for large
molecules, become feasible for generating the necessary reference data used to train
the neural network
Heat/mortality sensitivities in Los Angeles during winter: a unique phenomenon in the United States
Abstract Background Extreme heat is often associated with elevated levels of human mortality, particularly across the mid-latitudes. Los Angeles, CA exhibits a unique, highly variable winter climate, with brief periods of intense heat caused by downsloping winds commonly known as Santa Ana winds. The goal is to determine if Los Angeles County is susceptible to heat-related mortality during the winter season. This is the first study to specifically evaluate heat-related mortality during the winter for a U.S. city. Methods Utilizing the Spatial Synoptic Classification system in Los Angeles County from 1979 through 2010, we first relate daily human mortality to synoptic air mass type during the winter season (December, January, February) using Welch’s t-tests. However, this methodology is only somewhat effective at controlling for important inter- and intra-annual trends in human mortality unrelated to heat such as influenza outbreaks. As a result, we use distributed lag nonlinear modeling (DLNM) to evaluate if the relative risk of human mortality increases during higher temperatures in Los Angeles, as the DLNM is more effective at controlling for variability at multiple temporal scales within the human mortality dataset. Results Significantly higher human mortality is uncovered in winter when dry tropical air is present in Los Angeles, particularly among those 65 years and older (p < 0.001). The DLNM reveals the relative risk of human mortality increases when above average temperatures are present. Results are especially pronounced for maximum and mean temperatures, along with total mortality and those 65 + . Conclusions The discovery of heat-related mortality in winter is a unique finding in the United States, and we recommend stakeholders consider warning and intervention techniques to mitigate the role of winter heat on human health in the County
Heat/mortality sensitivities in Los Angeles during winter: a unique phenomenon in the United States
Assessment of Carotenoid Bioavailability of Whole Foods Using a Caco-2 Cell Culture Model Coupled with an in Vitro Digestion
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Risk of COVID-19 after natural infection or vaccinationResearch in context
Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health