486 research outputs found

    Precursors To and Pathways Through Conversion: Catalytic Experiences of Born Again Christian College Students

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    Born again Christians are a significant religious population in the United States, and throughout the world. The process by which a born again identity is assumed is not clearly described in the research literature. Therefore, we asked 18 born again Christian college students a series of questions designed to uncover what led to their identity of being born again. Responses fell into three overarching themes. First, participants described exposure within relationships to God’s principles. Second, participants noted the influence of introspection and reflection on their lives apart from the influence of God. Third, participants had an active response in which they reported such things as recognizing conviction by the Holy Spirit, that they decided to act on that conviction, and that they took action to follow Jesus. Findings are discussed within the framework of Cohen and Hill’s (2007) theory of religion as culture

    Large Deletions in the pAtC58 Megaplasmid of Agrobacterium tumefaciens Can Confer Reduced Carriage Cost and Increased Expression of Virulence Genes

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    The accessory plasmid pAtC58 of the common laboratory strain of Agrobacterium tumefaciens confers numerous catabolic functions and has been proposed to play a role in virulence. Genomic sequencing of evolved laboratory strains of A. tumefaciens revealed the presence of multiple deletion events in the At plasmid, with reductions in plasmid size ranging from 25% to 30% (115–194 kb). Flanking both ends of the sites of these deletions is a short-nucleotide repeat sequence that is in a single copy in the deleted plasmids, characteristic of a phage- or transposon-mediated deletion event. This repeat sequence is widespread throughout the C58 genome, but concentrated on the At plasmid, suggesting its frequency to be nonrandom. In this study, we assess the prevalence of the larger of these deletions in multiple C58 derivatives and characterize its functional significance. We find that in addition to elevating virulence gene expression, this deletion is associated with a significantly reduced carriage cost to the cell. These observations are a clear demonstration of the dynamic nature of the bacterial genome and suggest a mechanism for genetic plasticity of these costly but otherwise stable plasmids. Additionally, this phenomenon could be the basis for some of the dramatic recombination events so ubiquitous within and among megaplasmids

    Wastewater Sample Site Selection to Estimate Geographically Resolved Community Prevalence of COVID-19: A Sampling Protocol Perspective

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    Wastewater monitoring for virus infections within communities can complement conventional clinical surveillance. Currently, most SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) clinical testing is voluntary and inconsistently available, except for a few occupational and educational settings, and therefore likely underrepresents actual population prevalence. Randomized testing on a regular basis to estimate accurate population-level infection rates is prohibitively costly and is hampered by a range of limitations and barriers associated with participation in clinical research. In comparison, community-level fecal monitoring can be performed through wastewater surveillance to effectively surveil communities. However, epidemiologically defined protocols for wastewater sample site selection are lacking. Herein, we describe methods for developing a geographically resolved population-level wastewater sampling approach in Jefferson County, Kentucky, and present preliminary results. Utilizing this site selection protocol, samples (n = 237) were collected from 17 wastewater catchment areas, September 8 to October 30, 2020 from one to four times per week in each area and compared to concurrent clinical data aggregated to wastewater catchment areas and county level. SARS-CoV-2 RNA was consistently present in wastewater during the studied period, and varied by area. Data obtained using the site selection protocol showed variation in geographically resolved wastewater SARS-CoV-2 RNA concentration compared to clinical rates. These findings highlight the importance of neighborhood-equivalent spatial scales and provide a promising approach for viral epidemic surveillance, thus better guiding spatially targeted public health mitigation strategies

    The Relation of Diabetes, Impaired Fasting Blood Glucose, and Insulin Resistance to Left Ventricular Structure and Function in African Americans: The Jackson Heart Study

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    OBJECTIVE We assessed the relation of diabetes and insulin resistance (IR) on left ventricular (LV) structure and function in African Americans. RESEARCH DESIGN AND METHODS Among those receiving echocardiograms in cycle 1 of the Jackson Heart Study, we assessed the sex-specific relation of fasting blood glucose (FBG), diabetes, and IR to LV structure and function, adjusting for age, systolic blood pressure, antihypertensive medications, and BMI. RESULTS Among 2,399 participants, LV mass index (Pwomen = 0.0002 and Pmen = 0.02), posterior wall thickness (Pwomen = 0.01 and Pmen = 0.05), and interventricular septal wall thickness (Pwomen = 0.01) were related to FBG categories. Among those with normal FBG and no diabetes, concentric remodeling and low ejection fraction in women and LV mass index and posterior wall thickness in men were related to IR. CONCLUSIONS In the largest study of its kind in a community-based cohort of African Americans, we found a relation of FBG category and IR to LV structure and function

    A pilot study comparing the metabolic profiles of elite-level athletes from different sporting disciplines

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    Background: The outstanding performance of an elite athlete might be associated with changes in their blood metabolic profile. The aims of this study were to compare the blood metabolic profiles between moderate- and high-power and endurance elite athletes and to identify the potential metabolic pathways underlying these differences. Methods: Metabolic profiling of serum samples from 191 elite athletes from different sports disciplines (121 high- and 70 moderate-endurance athletes, including 44 high- and 144 moderate-power athletes), who participated in national or international sports events and tested negative for doping abuse at anti-doping laboratories, was performed using non-targeted metabolomics-based mass spectroscopy combined with ultrahigh-performance liquid chromatography. Multivariate analysis was conducted using orthogonal partial least squares discriminant analysis. Differences in metabolic levels between high- and moderate-power and endurance sports were assessed by univariate linear models. Results: Out of 743 analyzed metabolites, gamma-glutamyl amino acids were significantly reduced in both high-power and high-endurance athletes compared to moderate counterparts, indicating active glutathione cycle. High-endurance athletes exhibited significant increases in the levels of several sex hormone steroids involved in testosterone and progesterone synthesis, but decreases in diacylglycerols and ecosanoids. High-power athletes had increased levels of phospholipids and xanthine metabolites compared to moderate-power counterparts. Conclusions: This pilot data provides evidence that high-power and high-endurance athletes exhibit a distinct metabolic profile that reflects steroid biosynthesis, fatty acid metabolism, oxidative stress, and energy-related metabolites. Replication studies are warranted to confirm differences in the metabolic profiles associated with athletes’ elite performance in independent data sets, aiming ultimately for deeper understanding of the underlying biochemical processes that could be utilized as biomarkers with potential therapeutic implications

    Lubricating Bacteria Model for Branching growth of Bacterial Colonies

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    Various bacterial strains (e.g. strains belonging to the genera Bacillus, Paenibacillus, Serratia and Salmonella) exhibit colonial branching patterns during growth on poor semi-solid substrates. These patterns reflect the bacterial cooperative self-organization. Central part of the cooperation is the collective formation of lubricant on top of the agar which enables the bacteria to swim. Hence it provides the colony means to advance towards the food. One method of modeling the colonial development is via coupled reaction-diffusion equations which describe the time evolution of the bacterial density and the concentrations of the relevant chemical fields. This idea has been pursued by a number of groups. Here we present an additional model which specifically includes an evolution equation for the lubricant excreted by the bacteria. We show that when the diffusion of the fluid is governed by nonlinear diffusion coefficient branching patterns evolves. We study the effect of the rates of emission and decomposition of the lubricant fluid on the observed patterns. The results are compared with experimental observations. We also include fields of chemotactic agents and food chemotaxis and conclude that these features are needed in order to explain the observations.Comment: 1 latex file, 16 jpeg files, submitted to Phys. Rev.

    Combinatorial quorum sensing allows bacteria to resolve their social and physical environment

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    Quorum sensing (QS) is a cell–cell communication system that controls gene expression in many bacterial species, mediated by diffusible signal molecules. Although the intracellular regulatory mechanisms of QS are often well-understood, the functional roles of QS remain controversial. In particular, the use of multiple signals by many bacterial species poses a serious challenge to current functional theories. Here, we address this challenge by showing that bacteria can use multiple QS signals to infer both their social (density) and physical (mass-transfer) environment. Analytical and evolutionary simulation models show that the detection of, and response to, complex social/physical contrasts requires multiple signals with distinct half-lives and combinatorial (nonadditive) responses to signal concentrations. We test these predictions using the opportunistic pathogen Pseudomonas aeruginosa and demonstrate significant differences in signal decay betweeallyn its two primary signal molecules, as well as diverse combinatorial responses to dual-signal inputs. QS is associated with the control of secreted factors, and we show that secretome genes are preferentially controlled by synergistic “AND-gate” responses to multiple signal inputs, ensuring the effective expression of secreted factors in high-density and low mass-transfer environments. Our results support a new functional hypothesis for the use of multiple signals and, more generally, show that bacteria are capable of combinatorial communication

    Prediction by Promoter Logic in Bacterial Quorum Sensing

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    Quorum-sensing systems mediate chemical communication between bacterial cells, coordinating cell-density-dependent processes like biofilm formation and virulence-factor expression. In the proteobacterial LuxI/LuxR quorum sensing paradigm, a signaling molecule generated by an enzyme (LuxI) diffuses between cells and allosterically stimulates a transcriptional regulator (LuxR) to activate its cognate promoter (pR). By expressing either LuxI or LuxR in positive feedback from pR, these versatile systems can generate smooth (monostable) or abrupt (bistable) density-dependent responses to suit the ecological context. Here we combine theory and experiment to demonstrate that the promoter logic of pR – its measured activity as a function of LuxI and LuxR levels – contains all the biochemical information required to quantitatively predict the responses of such feedback loops. The interplay of promoter logic with feedback topology underlies the versatility of the LuxI/LuxR paradigm: LuxR and LuxI positive-feedback systems show dramatically different responses, while a dual positive/negative-feedback system displays synchronized oscillations. These results highlight the dual utility of promoter logic: to probe microscopic parameters and predict macroscopic phenotype
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