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71.
Patterns of contemporary hybridization inferred from paternity analysis in a four-oak-species forest
Background
Few studies address the issue of hybridization in a more than two-species context. The species-rich Quercus complex is one of the systems which can offer such an opportunity. To investigate the contemporary pattern of hybridization we sampled and genotyped 320 offspring from a natural mixed forest comprising four species of the European white oak complex: Quercus robur, Q. petraea, Q. pubescens, and Q. frainetto. 相似文献72.
Luminita Baditoiu Carmen Axente Diana Lungeanu Delia Muntean Florin Horhat Roxana Moldovan Elena Hogea Ovidiu Bedreag Dorel Sandesc Monica Licker 《Annals of clinical microbiology and antimicrobials》2017,16(1):71
Background
Over recent decades, a dramatic increase in infections caused by multidrug-resistant pathogens has been observed worldwide. The aim of the present study was to investigate the relationship between local resistance bacterial patterns and antibiotic consumption in an intensive care unit in a Romanian university hospital.Methods
A prospective study was conducted between 1st January 2012 and 31st December 2013. Data covering the consumption of antibacterial drugs and the incidence density for the main resistance phenotypes was collected on a monthly basis, and this data was aggregated quarterly. The relationship between the antibiotic consumption and resistance was investigated using cross-correlation, and four regression models were constructed, using the SPSS version 20.0 (IBM, Chicago, IL) and the R version 3.2.3 packages.Results
During the period studied, the incidence of combined-resistant and carbapenem-resistant P. aeruginosa strains increased significantly [(gradient = 0.78, R2 = 0.707, p = 0.009) (gradient = 0.74, R2 = 0.666, p = 0.013) respectively], mirroring the increase in consumption of β-lactam antibiotics with β-lactamase inhibitors (piperacillin/tazobactam) and carbapenems (meropenem) [(gradient = 10.91, R2 = 0.698, p = 0.010) and (gradient = 14.63, R2 = 0.753, p = 0.005) respectively]. The highest cross-correlation coefficients for zero time lags were found between combined-resistant vs. penicillins consumption and carbapenem-resistant P. aeruginosa strains vs. carbapenems consumption (0.876 and 0.928, respectively). The best model describing the relation between combined-resistant P. aeruginosa strains and penicillins consumption during a given quarter incorporates both the consumption and the incidence of combined-resistant strains in the hospital department during the previous quarter (multiple R2 = 0.953, p = 0.017). The best model for explaining the carbapenem resistance of P. aeruginosa strains based on meropenem consumption during a given quarter proved to be the adjusted model which takes into consideration both previous consumption and incidence density of strains during the previous quarter (Multiple R2 = 0.921, p = 0.037).Conclusions
The cross-correlation coefficients and the fitted regression models provide additional evidence that resistance during the a given quarter depends not only on the consumption of antibacterial chemotherapeutic drugs in both that quarter and the previous one, but also on the incidence of resistant strains circulating during the previous quarter.73.
74.
Lemieux M Bouchard F Gosselin P Paquin J Mateescu MA 《Biochemical and biophysical research communications》2011,(3):429-434
The objective of this study was to evaluate the human NCI-N87 cell line as a model for gastric permeability drug studies under pH conditions of the stomach. The optimal conditions that led NCI-N87 cells to form a typical differentiated gastric epithelial barrier were a seeding density of 2.5 × 105 cells/cm2 on porous inserts and growth in serum-complemented RPMI-1640 medium until 18–27 days post-confluency. The resulting cell monolayers showed moderately high transepithelial electrical resistance (TEER) values of about 500 Ω cm2, cells of polygonal morphology expressing E-cadherin and ZO-1 proteins at their contact surfaces, and production of mucus clusters. The monolayers withstood apical pH of 7.4 down to 3.0 with the basal pH fixed at 7.4. The apparent permeability coefficients (Papp) of model compounds were evaluated in the apical-to-basolateral and basolateral-to-apical directions under different pH gradients. The monolayers were impermeable to the integrity marker Lucifer Yellow (low Papp of 0.3–1.1 × 10−6 cm/s). The furosemide Papp (0.4–1.5 × 10−5 cm/s) were slightly dependent on pH but remained moderate. The caffeine Papp (4.2–5.0 × 10−5 cm/s) were higher and insensitive to pH changes. The NCI-N87 cell line provides a useful in vitro tool to assess gastric drug permeability and absorption under physiologic conditions prevailing in the human stomach. 相似文献
75.
76.
Ezhevskaya M Trandafir F Moens L Dewilde S Van Doorslaer S 《Journal of inorganic biochemistry》2011,105(9):1131-1137
The function of neuroglobin, a member of the vertebrate globin family, is still unknown. In human neuroglobin (NGB), the formation of a disulfide bridge between the CysCD7 and CysD5 is known to affect the heme environment and its ligand-binding kinetics. Here, we show by means of EPR that the PheB10 residue plays a key role in transmitting the structural information from the disulfide bridge to the heme-pocket region. While formation of a disulfide bridge in ferric wild-type NGB leads to a considerable change of its EPR parameters, only minor changes are observed in the case of ferric PheB10Leu NGB. Furthermore, wild-type NGB is found to be much more stable in the presence of H2O2 than its PheB10Leu or its HisE7Leu mutants. While tyrosyl radicals are induced in HisE7Leu NGB by the addition of H2O2, this is not the case for wild-type and PheB10Leu NGB. The results will be discussed in terms of the protein's putative functions. 相似文献
77.
Alexandru Milcu Christiane Roscher Arthur Gessler Dörte Bachmann Annette Gockele Markus Guderle Damien Landais Clément Piel Christophe Escape Sebastien Devidal Olivier Ravel Nina Buchmann Gerd Gleixner Anke Hildebrandt Jacques Roy 《Ecology letters》2014,17(4):435-444
Little is known about the role of plant functional diversity for ecosystem‐level carbon (C) fluxes. To fill this knowledge gap, we translocated monoliths hosting communities with four and 16 sown species from a long‐term grassland biodiversity experiment (‘The Jena Experiment’) into a controlled environment facility for ecosystem research (Ecotron). This allowed quantifying the effects of plant diversity on ecosystem C fluxes as well as three parameters of C uptake efficiency (water and nitrogen use efficiencies and apparent quantum yield). By combining data on ecosystem C fluxes with vegetation structure and functional trait‐based predictors, we found that increasing plant species and functional diversity led to higher gross and net ecosystem C uptake rates. Path analyses and light response curves unravelled the diversity of leaf nitrogen concentration in the canopy as a key functional predictor of C fluxes, either directly or indirectly via LAI and aboveground biomass. 相似文献
78.
Artur Dzialuk Igor Chybicki Roman Gout Tomasz Mączka Peter Fleischer Heino Konrad Alexandru Lucian Curtu Nicolae Sofletea Alain Valadon 《Conservation Genetics》2014,15(6):1433-1445
In Europe, most of the alpine timberline ecotone has been altered by human activities and climate change. Hence, mountain forests are of the highest conservation interest. Here, we screened 25 populations of Swiss stone pine (Pinus cembra L.) from the Carpathians and the Alps, using a set of ten microsatellite primers to assess the relative conservation value of populations sampled in Polish and Slovak Tatra National Parks, where potential extinction risk is the highest within the Carpathian range. Although endangered, with small and fragmented populations, P. cembra in the Tatra Mts. shows high levels of allelic richness (AR = 5.0) and observed heterozygosity (H o = 0.554). Our results suggest that anthropogenic habitat fragmentation has had little impact on DNA variation of Swiss stone pine in the Tatra Mts. However, the effects of changing conditions on the genetic structure may occur with a substantial time delay due to the long life span of P. cembra. Moreover, inbreeding depression may occur in the next generations, since we found inbreeding (F IS = 0.063) and elevated coancestry coefficient (θ = 0.062) in all populations. Also a shallow pattern of genetic differentiation between populations was found, indicating recent fragmentation of a common gene pool that formerly occupied a larger range. Therefore, the Tatra Mts. can be considered as a single conservation unit. Based on our results, we suggest possible conservation activities for Swiss stone pine both in Poland and Slovakia. 相似文献
79.
Alexandru Coman Daniel N. Maftei Whitney S. Krueger Gary L. Heil Razvan M. Chereches Emanuela Sirlincan Paul Bria Claudiu Dragnea Iosif Kasler Marissa A. Valentine Gregory C. Gray 《PloS one》2014,9(5)
Background
In this prospective study we sought to examine seroepidemiological evidence for acute zoonotic influenza virus infection among Romanian agricultural workers.Methods
Sera were drawn upon enrollment (2009) and again at 12 and 24 months from 312 adult agriculture workers and 51 age-group matched controls. Participants were contacted monthly for 24 months and queried regarding episodes of acute influenza-like illnesses (ILI). Cohort members meeting ILI criteria permitted respiratory swab collections as well as acute and convalescent serum collection. Serologic assays were performed against 9 avian, 3 swine, and 3 human influenza viruses.Results
During the two-year follow-up, a total of 23 ILI events were reported. Two subjects'' specimens were identified as influenza A by rRT-PCR. During the follow-up period, three individuals experienced elevated microneutralization antibody titers ≥1∶80 against three (one each) avian influenza viruses: A/Teal/Hong Kong/w312/97(H6N1), A/Hong Kong/1073/1999(H9N2), or A/Duck/Alberta/60/1976(H12N5). However, none of these participants met the criteria for poultry exposure. A number of subjects demonstrated four-fold increases over time in hemagglutination inhibition (HI) assay titers for at least one of the three swine influenza viruses (SIVs); however, it seems likely that two of these three responses were due to cross-reacting antibody against human influenza. Only elevated antibody titers against A/Swine/Flanders/1/1998(H3N2) lacked evidence for such confounding. In examining risk factors for elevated antibody against this SIV with multiple logistic regression, swine exposure (adjusted OR = 1.8, 95% CI 1.1–2.8) and tobacco use (adjusted OR = 1.8; 95% CI 1.1–2.9) were important predictors.Conclusions
While Romania has recently experienced multiple incursions of highly pathogenic avian influenza among domestic poultry, this cohort of Romanian agriculture workers had sparse evidence of avian influenza virus infections. In contrast, there was evidence, especially among the swine exposed participants, of infections with human and one swine H3N2 influenza virus. 相似文献80.
Anika Wranke Benjamin Heidrich Stefanie Ernst Beatriz Calle Serrano Florin Alexandru Caruntu Manuela Gabriela Curescu Kendal Yalcin Selim Gürel Stefan Zeuzem Andreas Erhardt Stefan Lüth George V. Papatheodoridis Birgit Bremer Judith Stift Jan Grabowski Janina Kirschner Kerstin Port Markus Cornberg Christine S. Falk Hans-Peter Dienes Svenja Hardtke Michael P. Manns Cihan Yurdaydin Heiner Wedemeyer HIDIT- Study Group 《PloS one》2014,9(7)