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61.
Stark JH Sharma R Ostroff S Cummings DA Ermentrout B Stebbins S Burke DS Wisniewski SR 《PloS one》2012,7(3):e34245
Background
Influenza is a contagious respiratory disease responsible for annual seasonal epidemics in temperate climates. An understanding of how influenza spreads geographically and temporally within regions could result in improved public health prevention programs. The purpose of this study was to summarize the spatial and temporal spread of influenza using data obtained from the Pennsylvania Department of Health''s influenza surveillance system.Methodology and Findings
We evaluated the spatial and temporal patterns of laboratory-confirmed influenza cases in Pennsylvania, United States from six influenza seasons (2003–2009). Using a test of spatial autocorrelation, local clusters of elevated risk were identified in the South Central region of the state. Multivariable logistic regression indicated that lower monthly precipitation levels during the influenza season (OR = 0.52, 95% CI: 0.28, 0.94), fewer residents over age 64 (OR = 0.27, 95% CI: 0.10, 0.73) and fewer residents with more than a high school education (OR = 0.76, 95% CI: 0.61, 0.95) were significantly associated with membership in this cluster. In addition, time series analysis revealed a temporal lag in the peak timing of the influenza B epidemic compared to the influenza A epidemic.Conclusions
These findings illustrate a distinct spatial cluster of cases in the South Central region of Pennsylvania. Further examination of the regional transmission dynamics within these clusters may be useful in planning public health influenza prevention programs. 相似文献62.
Samuel A. Bedgood Sarah E. Mastroni Matthew E. S. Bracken 《Proceedings. Biological sciences / The Royal Society》2020,287(1940)
Mutualistic symbioses are common, especially in nutrient-poor environments where an association between hosts and symbionts can allow the symbiotic partners to persist and collectively out-compete non-symbiotic species. Usually these mutualisms are built on an intimate transfer of energy and nutrients (e.g. carbon and nitrogen) between host and symbiont. However, resource availability is not consistent, and the benefit of the symbiotic association can depend on the availability of resources to mutualists. We manipulated the diets of two temperate sea anemone species in the genus Anthopleura in the field and recorded the responses of sea anemones and algal symbionts in the family Symbiodiniaceae to our treatments. Algal symbiont density, symbiont volume and photosynthetic efficiency of symbionts responded to changes in sea anemone diet, but the responses depended on the species of sea anemone. We suggest that temperate sea anemones and their symbionts can respond to changes in anemone diet, modifying the balance between heterotrophy and autotrophy in the symbiosis. Our data support the hypothesis that symbionts are upregulated or downregulated based on food availability, allowing for a flexible nutritional strategy based on external resources. 相似文献
63.
Kenefick RW Cheuvront SN Elliott LD Ely BR Sawka MN 《American journal of physiology. Regulatory, integrative and comparative physiology》2012,302(2):R252-R258
Appropriate quantification of analytical and biological variation of thermoregulatory sweating has important practical utility for research design and statistical analysis. We sought to examine contributors to variability in local forearm sweating rate (SR) and sweating onset (SO) and to evaluate the potential for using bilateral measurements. Two women and eight men (26 ± 9 yr; 79 ± 12 kg) completed 5 days of heat acclimation and walked (1.8 l/min VO(2)) on three occasions for 30 min in 40°C, 20% RH, while local SR and SO were measured. Local SR measures among days were not different (2.14 ± 0.72 vs. 2.02 ± 0.79 vs. 2.31 ± 0.72 mg·cm(2)·min(-1), P = 0.19) nor was SO (10.47 ± 2.54 vs. 10.04 ± 2.97 vs. 9.87 ± 3.44 min P = 0.82). Bilateral SR (2.14 ± 0.72 vs. 2.16 ± 0.71 mg·cm(2)·min(-1), P = 0.56) and SO (10.47 ± 2.54 vs. 10.83 ± 2.48 min, P = 0.09) were similar and differences were ≤ 1 SD of day-to-day differences for a single forearm. Analytical imprecision (CV(a)), within (CV(i))-, and between (CV(g))-subjects' coefficient of variation for local SR were 2.4%, 22.3%, and 56.4%, respectively, and were 0%, 9.6%, and 41%, respectively, for SO. We conclude: 1) technologically, sweat capsules contribute negligibly to sweat measurement variation; 2) bilateral measures of SR and SO appear interchangeable; 3) when studying potential factors affecting sweating, changes in SO afford a more favorable signal-to-noise ratio vs. changes in SR. These findings provide a quantitative basis for study design and optimization of power/sample size analysis in the evaluation of thermoregulatory sweating. 相似文献
64.
Roxane M Barthélémy Anne Chenuil Samuel Blanquart Jean-Paul Casanova Eric Faure 《BMC evolutionary biology》2007,7(1):146
Background
Chaetognaths, or arrow worms, are small marine, bilaterally symmetrical metazoans. The objective of this study was to analyse ribosomal protein (RP) coding sequences from a published collection of expressed sequence tags (ESTs) from a chaetognath (Spadella cephaloptera) and to use them in phylogenetic studies. 相似文献65.
66.
Jean-Luc Montillet Nathalie Leonhardt Samuel Mondy Sylvain Tranchimand Dominique Rumeau Marie Boudsocq Ana Victoria Garcia Thierry Douki Jean Bigeard Christiane Laurière Anne Chevalier Carmen Castresana Heribert Hirt 《PLoS biology》2013,11(3)
Plant stomata function in innate immunity against bacterial invasion and abscisic acid (ABA) has been suggested to regulate this process. Using genetic, biochemical, and pharmacological approaches, we demonstrate that (i) the Arabidopsis thaliana nine-specific-lipoxygenase encoding gene, LOX1, which is expressed in guard cells, is required to trigger stomatal closure in response to both bacteria and the pathogen-associated molecular pattern flagellin peptide flg22; (ii) LOX1 participates in stomatal defense; (iii) polyunsaturated fatty acids, the LOX substrates, trigger stomatal closure; (iv) the LOX products, fatty acid hydroperoxides, or reactive electrophile oxylipins induce stomatal closure; and (v) the flg22-mediated stomatal closure is conveyed by both LOX1 and the mitogen-activated protein kinases MPK3 and MPK6 and involves salicylic acid whereas the ABA-induced process depends on the protein kinases OST1, MPK9, or MPK12. Finally, we show that the oxylipin and the ABA pathways converge at the level of the anion channel SLAC1 to regulate stomatal closure. Collectively, our results demonstrate that early biotic signaling in guard cells is an ABA-independent process revealing a novel function of LOX1-dependent stomatal pathway in plant immunity. 相似文献
67.
Jessica K. Calland Ben Pascoe Sion C. Bayliss Evangelos Mourkas Elvire Berthenet Harry A. Thorpe Matthew D. Hitchings Edward J. Feil Jukka Corander Martin J. Blaser Daniel Falush Samuel K. Sheppard 《PLoS genetics》2021,17(9)
Measuring molecular evolution in bacteria typically requires estimation of the rate at which nucleotide changes accumulate in strains sampled at different times that share a common ancestor. This approach has been useful for dating ecological and evolutionary events that coincide with the emergence of important lineages, such as outbreak strains and obligate human pathogens. However, in multi-host (niche) transmission scenarios, where the pathogen is essentially an opportunistic environmental organism, sampling is often sporadic and rarely reflects the overall population, particularly when concentrated on clinical isolates. This means that approaches that assume recent common ancestry are not applicable. Here we present a new approach to estimate the molecular clock rate in Campylobacter that draws on the popular probability conundrum known as the ‘birthday problem’. Using large genomic datasets and comparative genomic approaches, we use isolate pairs that share recent common ancestry to estimate the rate of nucleotide change for the population. Identifying synonymous and non-synonymous nucleotide changes, both within and outside of recombined regions of the genome, we quantify clock-like diversification to estimate synonymous rates of nucleotide change for the common pathogenic bacteria Campylobacter coli (2.4 x 10−6 s/s/y) and Campylobacter jejuni (3.4 x 10−6 s/s/y). Finally, using estimated total rates of nucleotide change, we infer the number of effective lineages within the sample time frame–analogous to a shared birthday–and assess the rate of turnover of lineages in our sample set over short evolutionary timescales. This provides a generalizable approach to calibrating rates in populations of environmental bacteria and shows that multiple lineages are maintained, implying that large-scale clonal sweeps may take hundreds of years or more in these species. 相似文献
68.
Barragán-Ocaña Alejandro Reyes-Ruiz Gerardo Olmos-Peña Samuel Gómez-Viquez Hortensia 《Transgenic research》2019,28(3-4):391-399
Transgenic Research - Transgenic crops have been the recipient of strong support as well as vigorously opposed opinions since their appearance. In any case, their growth throughout the world has... 相似文献
69.
Favaro PM de Souza Medina S Traina F Bassères DS Costa FF Saad ST 《Biochemical and biophysical research communications》2003,311(2):365-371
The very large family of Formin proteins is involved in processes such as morphogenesis, embryonic differentiation, cell polarity, and cytokinesis. A novel human gene from the Formin family, denominated human leukocyte formin gene, was cloned. The cDNA of the gene was determined to be 3959bp long with an open reading frame of 3302bp and computational analysis located this gene on chromosome 17, suggesting that it is composed of 27 exons. Northern blot analysis revealed a restricted expression of mRNA in the thymus, spleen, and peripheral blood leukocytes in normal human tissues. Western blot analysis demonstrated that the protein encoded by this gene is overexpressed in lymphoid malignancies; cancer cell lines and peripheral blood leukocyte from chronic lymphocytic leukemia (CLL) patients. Furthermore, the human leukocyte formin protein was observed to associate with Akt, a critical survival regulator in many different cell types. 相似文献
70.
Samuel Jalali Gurukumar K. Ramanathan Prasanna Tamarapu Parthasarathy Salman Aljubran Lakshmi Galam Asfiya Yunus Sara Garcia Ruan R. Cox Jr. Richard F. Lockey Narasaiah Kolliputi 《PloS one》2012,7(10)
Pulmonary Arterial Hypertension (PAH) is a progressive devastating disease characterized by excessive proliferation of the Pulmonary Arterial Smooth Muscle Cells (PASMCs). Studies suggest that PAH and cancers share an apoptosis-resistant state featuring excessive cell proliferation. MicroRNA-206 (miR-206) is known to regulate proliferation and is implicated in various types of cancers. However, the role of miR-206 in PAH has not been studied. In this study, it is hypothesized that miR-206 could play a role in the proliferation of PASMCs. In the present study, the expression patterns of miR-206 were investigated in normal and hypertensive mouse PASMCs. The effects of miR-206 in modulating cell proliferation, apoptosis and smooth muscle cell markers in human pulmonary artery smooth muscle cells (hPASMCs) were investigated in vitro. miR-206 expression in mouse PASMCs was correlated with an increase in right ventricular systolic pressure. Reduction of miR-206 levels in hPASMCs causes increased proliferation and reduced apoptosis and these effects were reversed by the overexpression of miR-206. miR-206 over expression also increased the levels of smooth muscle cell differentiation markers α-smooth muscle actin and calponin implicating its importance in the differentiation of SMCs. miR-206 overexpression down regulated Notch-3 expression, which is key a factor in PAH development. These results suggest that miR-206 is a potential regulator of proliferation, apoptosis and differentiation of PASMCs, and that it could be used as a novel treatment strategy in PAH. 相似文献