88 research outputs found

    Population Analysis of the Fusarium graminearum Species Complex from Wheat in China Show a Shift to More Aggressive Isolates

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    A large number of Fusarium isolates was collected from blighted wheat spikes originating from 175 sampling sites, covering 15 provinces in China. Species and trichothecene chemotype determination by multilocus genotyping (MLGT) indicated that F. graminearum s. str. with the 15-acetyl deoxynivalenol (15ADON) chemotype and F. asiaticum with either the nivalenol (NIV) or the 3-acetyl deoxynivalenol (3ADON) chemotype were the dominant causal agents. Bayesian model-based clustering with allele data obtained with 12 variable number of tandem repeats (VNTR) markers, detected three genetic clusters that also show distinct chemotypes. High levels of population genetic differentiation and low levels of effective number of migrants were observed between these three clusters. Additional genotypic analyses revealed that F. graminearum s. str. and F. asiaticum are sympatric. In addition, composition analysis of these clusters indicated a biased gene flow from 3ADON to NIV producers in F. asiaticum. In phenotypic analyses, F. asiaticum that produce 3ADON revealed significant advantages over F. asiaticum that produce NIV in pathogenicity, growth rate, fecundity, conidial length, trichothecene accumulation and resistance to benzimidazole. These results suggest that natural selection drives the spread of a more vigorous, more toxigenic pathogen population which also shows higher levels of fungicide resistance

    Changing Patterns of Microhabitat Utilization by the Threespot Damselfish, Stegastes planifrons, on Caribbean Reefs

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    Background: The threespot damselfish, Stegastes planifrons (Cuvier), is important in mediating interactions among corals, algae, and herbivores on Caribbean coral reefs. The preferred microhabitat of S. planifrons is thickets of the branching staghorn coral Acropora cervicornis. Within the past few decades, mass mortality of A. cervicornis from white-band disease and other factors has rendered this coral a minor ecological component throughout most of its range. Methodology/Principal Findings: Survey data from Jamaica (heavily fished), Florida and the Bahamas (moderately fished), the Cayman Islands (lightly to moderately fished), and Belize (lightly fished) indicate that distributional patterns of S. planifrons are positively correlated with live coral cover and topographic complexity. Our results suggest that speciesspecific microhabitat preferences and the availability of topographically complex microhabitats are more important than the abundance of predatory fish as proximal controls on S. planifrons distribution and abundance. Conclusions/Significance: The loss of the primary microhabitat of S. planifrons—A. cervicornis—has forced a shift in the distribution and recruitment of these damselfish onto remaining high-structured corals, especially the Montastraea annulari

    The three major axes of terrestrial ecosystem function.

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    The leaf economics spectrum1,2 and the global spectrum of plant forms and functions3 revealed fundamental axes of variation in plant traits, which represent different ecological strategies that are shaped by the evolutionary development of plant species2. Ecosystem functions depend on environmental conditions and the traits of species that comprise the ecological communities4. However, the axes of variation of ecosystem functions are largely unknown, which limits our understanding of how ecosystems respond as a whole to anthropogenic drivers, climate and environmental variability4,5. Here we derive a set of ecosystem functions6 from a dataset of surface gas exchange measurements across major terrestrial biomes. We find that most of the variability within ecosystem functions (71.8%) is captured by three key axes. The first axis reflects maximum ecosystem productivity and is mostly explained by vegetation structure. The second axis reflects ecosystem water-use strategies and is jointly explained by variation in vegetation height and climate. The third axis, which represents ecosystem carbon-use efficiency, features a gradient related to aridity, and is explained primarily by variation in vegetation structure. We show that two state-of-the-art land surface models reproduce the first and most important axis of ecosystem functions. However, the models tend to simulate more strongly correlated functions than those observed, which limits their ability to accurately predict the full range of responses to environmental changes in carbon, water and energy cycling in terrestrial ecosystems7,8

    Author Correction: The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data

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    The following authors were omitted from the original version of this Data Descriptor: Markus Reichstein and Nicolas Vuichard. Both contributed to the code development and N. Vuichard contributed to the processing of the ERA-Interim data downscaling. Furthermore, the contribution of the co-author Frank Tiedemann was re-evaluated relative to the colleague Corinna Rebmann, both working at the same sites, and based on this re-evaluation a substitution in the co-author list is implemented (with Rebmann replacing Tiedemann). Finally, two affiliations were listed incorrectly and are corrected here (entries 190 and 193). The author list and affiliations have been amended to address these omissions in both the HTML and PDF versions

    The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data.

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    The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their data to create global datasets. Data were quality controlled and processed using uniform methods, to improve consistency and intercomparability across sites. The dataset is already being used in a number of applications, including ecophysiology studies, remote sensing studies, and development of ecosystem and Earth system models. FLUXNET2015 includes derived-data products, such as gap-filled time series, ecosystem respiration and photosynthetic uptake estimates, estimation of uncertainties, and metadata about the measurements, presented for the first time in this paper. In addition, 206 of these sites are for the first time distributed under a Creative Commons (CC-BY 4.0) license. This paper details this enhanced dataset and the processing methods, now made available as open-source codes, making the dataset more accessible, transparent, and reproducible

    Dor dentaria e fatores associados em adolescentes brasileiros: a Pesquia Nacional de Saude do Escolar (PeNSE), Brasil, 2009

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    Abstract published in English and Portuguese English title: Dental pain and associated factors in Brazilian adolescents: the National school-based health survey (PeNSE), Brazil, 2009The aim of this study was to assess the prevalence of dental pain and associated socio-demographic and behavioral factors in Brazilian adolescents, using data from the National School-Based Health Survey (PeNSE), Brazil, 2009. The survey was conducted by the Brazilian Institute of Geography and Statistics (IBGE) and Ministry of Health in students 11 to 17 years of age or older in the 27 State capitals, using a self-administered questionnaire. Analyses included Poisson regression following a hierarchical approach. Prevalence of dental pain in the sample (n = 54,985) in the previous six months was 17.8% (95%CI: 17.5-18.1). Higher prevalence was associated with female gender, age 14 years and over, racial self-identification as black, brown, or indigenous, enrollment in public schools, lower maternal schooling, not living with the mother, history of smoking or drinking, less frequent toothbrushing, and heavy consumption of sweets and soft drinks. Dental pain was thus associated with socio-demographic factors and health-related behaviors. = O objetivo deste estudo foi estimar a prevalência da dor de dente em adolescentes brasileiros e analisar fatores sociodemográficos e comportamentais associados, utilizando os dados da Pesquisa Nacional de Saúde do Escolar (PeNSE) de 2009. A pesquisa foi realizada pelo Instituto Brasileiro de Geografia e Estatística e pelo Ministério da Saúde em escolares com idades entre 11 e 17 anos ou mais, das 27 capitais brasileiras, por meio de questionário autoaplicável. Utilizou-se a análise de regressão de Poisson, segundo um modelo hierárquico de determinação. A prevalência de dor na amostra (n = 54.985) nos últimos seis meses foi de 17,8% (IC95%: 17,5-18,1). Prevalências mais elevadas foram encontradas em mulheres, naqueles com 14 anos ou mais, das raças preta, parda e indígena, de escolas públicas, cujas mães tinham baixa escolaridade, que não moravam com a mãe, que haviam experimentado cigarro e álcool alguma vez na vida, que relataram menor frequência de escovação e maior consumo de guloseimas e refrigerantes. A prevalência de dor foi considerável e associada a aspectos sociodemográficos e de comportamentos relacionados à saúde.Maria do Carmo Matias Freire, Cláudio Rodrigues Leles, Luciana Monteiro Vasconcelos Sardinha, Moacir Paludetto Junior, Deborah Carvalho Malta, Marco A. Pere
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