Maine Woods

https://digitalcommons.library.umaine.edu/mmb-me/1137/thumbnail.jp

Seasonal drought limits tree species across the Neotropics

Within the tropics, the species richness of tree communities is strongly and positively associated with precipitation. Previous research has suggested that this macroecological pattern is driven by the negative effect of water-stress on the physiological processes of most tree species. This process implies that the range limits of taxa are defined by their ability to occur under dry conditions, and thus in terms of species distributions it predicts a nested pattern of taxa distribution from wet to dry areas. However, this ‘dry-tolerance’ hypothesis has yet to be adequately tested at large spatial and taxonomic scales. Here, using a dataset of 531 inventory plots of closed canopy forest distributed across the Western Neotropics we investigated how precipitation, evaluated both as mean annual precipitation and as the maximum climatological water deficit, influences the distribution of tropical tree species, genera and families. We find that the distributions of tree taxa are indeed nested along precipitation gradients in the western Neotropics. Taxa tolerant to seasonal drought are disproportionally widespread across the precipitation gradient, with most reaching even the wettest climates sampled; however, most taxa analysed are restricted to wet areas. Our results suggest that the ‘dry tolerance’ hypothesis has broad applicability in the world's most species-rich forests. In addition, the large number of species restricted to wetter conditions strongly indicates that an increased frequency of drought could severely threaten biodiversity in this region. Overall, this study establishes a baseline for exploring how tropical forest tree composition may change in response to current and future environmental changes in this region

Um sistema de classificação para avaliação de conhecimentos na formação de competências de um graduado universitário

Assessment of educational achievements of university students on the basis of rating and competence-based approaches is an urgent issue of pedagogy, psychology and methodology and requires research of various approaches and the search for effective methods of such an assessment. The main emphasis in the article is made on the study of the existing problems of the formation of a competence model of a university graduate, the formation of key competencies, the development of professional skills and their assessment. The author proposes a competence model and a method for assessing the level of competence formation of university students based on the apparatus of fuzzy logic, the author proves the expediency of its use, describes the features of analyzing and processing data, identifies further areas of research on this issue.La evaluación de los logros educativos de los estudiantes universitarios sobre la base de enfoques basados ​​en la calificación y las competencias es un tema urgente de pedagogía, psicología y metodología y requiere la investigación de varios enfoques y la búsqueda de métodos efectivos de tal evaluación. El énfasis principal en el artículo se hace en el estudio de los problemas existentes de la formación de un modelo competencial de un egresado universitario, la formación de competencias clave, el desarrollo de habilidades profesionales y su evaluación. El autor propone un modelo de competencia y un método para evaluar el nivel de formación de competencias de los estudiantes universitarios basado en el aparato de la lógica difusa, el autor demuestra la conveniencia de su uso, describe las características del análisis y procesamiento de datos, identifica otras áreas de investigación en este tema.A avaliação do desempenho educacional de estudantes universitários com base em avaliações e abordagens baseadas em competências é uma questão urgente de pedagogia, psicologia e metodologia e requer a pesquisa de várias abordagens e a busca de métodos eficazes de tal avaliação. A ênfase principal do artigo é colocada no estudo dos problemas existentes de formação de um modelo de competências de um graduado universitário, a formação de competências-chave, o desenvolvimento de competências profissionais e sua avaliação. O autor propõe um modelo de competências e um método para avaliar o nível de formação de competências de estudantes Universitario com base no aparato da lógica difusa, o autor prova a conveniência de seu uso, descreve as características de análise e processamento de dados, identifica outras áreas de pesquisa nesse assunto

RNA virus error catastrophe: Direct molecular test by using ribavirin

RNA viruses evolve rapidly. One source of this ability to rapidly change is the apparently high mutation frequency in RNA virus populations. A high mutation frequency is a central tenet of the quasispecies theory. A corollary of the quasispecies theory postulates that, given their high mutation frequency, animal RNA viruses may be susceptible to error catastrophe, where they undergo a sharp drop in viability after a modest increase in mutation frequency. We recently showed that the important broad-spectrum antiviral drug ribavirin (currently used to treat hepatitis C virus infections, among others) is an RNA virus mutagen, and we proposed that ribavirin's antiviral effect is by forcing RNA viruses into error catastrophe. However, a direct demonstration of error catastrophe has not been made for ribavirin or any RNA virus mutagen. Here we describe a direct demonstration of error catastrophe by using ribavirin as the mutagen and poliovirus as a model RNA virus. We demonstrate that ribavirin's antiviral activity is exerted directly through lethal mutagenesis of the viral genetic material. A 99.3% loss in viral genome infectivity is observed after a single round of virus infection in ribavirin concentrations sufficient to cause a 9.7-fold increase in mutagenesis. Compiling data on both the mutation levels and the specific infectivities of poliovirus genomes produced in the presence of ribavirin, we have constructed a graph of error catastrophe showing that normal polio-virus indeed exists at the edge of viability. These data suggest that RNA virus mutagens may represent a promising new class of antiviral drugs

Differential gene expression in Varroa jacobsoni mites following a host shift to European honey bees (Apis mellifera)

Background: Varroa mites are widely considered the biggest honey bee health problem worldwide. Until recently, Varroa jacobsoni has been found to live and reproduce only in Asian honey bee (Apis cerana) colonies, while V. destructor successfully reproduces in both A. cerana and A. mellifera colonies. However, we have identified an island population of V. jacobsoni that is highly destructive to A. mellifera, the primary species used for pollination and honey production. The ability of these populations of mites to cross the host species boundary potentially represents an enormous threat to apiculture, and is presumably due to genetic variation that exists among populations of V. jacobsoni that influences gene expression and reproductive status. In this work, we investigate differences in gene expression between populations of V. jacobsoni reproducing on A. cerana and those either reproducing or not capable of reproducing on A. mellifera, in order to gain insight into differences that allow V. jacobsoni to overcome its normal species tropism. Results: We sequenced and assembled a de novo transcriptome of V. jacobsoni. We also performed a differential gene expression analysis contrasting biological replicates of V. jacobsoni populations that differ in their ability to reproduce on A. mellifera. Using the edgeR, EBSeq and DESeq R packages for differential gene expression analysis, we found 287 differentially expressed genes (FDR ≤ 0.05), of which 91% were up regulated in mites reproducing on A. mellifera. In addition, mites found reproducing on A. mellifera showed substantially more variation in expression among replicates. We searched for orthologous genes in public databases and were able to associate 100 of these 287 differentially expressed genes with a functional description. Conclusions: There is differential gene expression between the two mite groups, with more variation in gene expression among mites that were able to reproduce on A. mellifera. A small set of genes showed reduced expression in mites on the A. mellifera host, including putative transcription factors and digestive tract developmental genes. The vast majority of differentially expressed genes were up-regulated in this host. This gene set showed enrichment for genes associated with mitochondrial respiratory function and apoptosis, suggesting that mites on this host may be experiencing higher stress, and may be less optimally adapted to parasitize it. Some genes involved in reproduction and oogenesis were also overexpressed, which should be further studied in regards to this host shift. © 2016 The Author(s)

Application of Backend and Frontend Systems on Go-Baby Application in Bandung City

The purpose of this research is that researchers build basic applications in solving problems that occur in housewives and career women, namely GO-BABY Application that provides facilities to find a place in caring for children, and can provide security, education, health and comfort for a child. Applications are built from 2 parts, namely the first part in the society side such as housewives / career women and the second part is the side of the provider of child care services. The application that is built will integrated between applications that are applied in the society and service providers through an Androidbased application and web based application. The results of this study will have a direct impact on both housewives/career women, in providing child care solutions that can be trusted while for child care services provider, provide convenience in the administration of child care services. Based on the function of the application, there are 2 parts that are given, namely to providers of child care services by providing an easy function of administrative data processing, including registration of child care services through online or offline, providing ease in processing data on children's facilities, ease of payment report on income of child care services. Whereas for the community is the ease in the process of online registration and booking of child care services quickly and reliably

Brain mechanisms that underlie the effects of motivational audiovisual stimuli on psychophysiological responses during exercise

Motivational audiovisual stimuli such as music and video have been widely used in the realm of exercise and sport as a means by which to increase situational motivation and enhance performance. The present study addressed the mechanisms that underlie the effects of motivational stimuli on psychophysiological responses and exercise performance. Twenty-two participants completed fatiguing isometric handgrip-squeezing tasks under two experimental conditions (motivational audiovisual condition and neutral audiovisual condition) and a control condition. Electrical activity in the brain and working muscles was analyzed by use of electroencephalography and electromyography, respectively. Participants were asked to squeeze the dynamometer maximally for 30 s. A single-item motivation scale was administered after each squeeze. Results indicated that task performance and situational motivational were superior under the influence of motivational stimuli when compared to the other two conditions (~20% and ~25%, respectively). The motivational stimulus downregulated the predominance of low-frequency waves (theta) in the right frontal regions of the cortex (F8), and upregulated high-frequency waves (beta) in the central areas (C3 and C4). It is suggested that motivational sensory cues serve to readjust electrical activity in the brain; a mechanism by which the detrimental effects of fatigue on the efferent control of working muscles is ameliorated.This research was supported, in part, by grants from the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

An Enhanced Single Base Extension Technique for the Analysis of Complex Viral Populations

Many techniques for the study of complex populations provide either specific information on a small number of variants or general information on the entire population. Here we describe a powerful new technique for elucidating mutation frequencies at each genomic position in a complex population. This single base extension (SBE) based microarray platform was designed and optimized using poliovirus as the target genotype, but can be easily adapted to assay populations derived from any organism. The sensitivity of the method was demonstrated by accurate and consistent readouts from a controlled population of mutant genotypes. We subsequently deployed the technique to investigate the effects of the nucleotide analog ribavirin on a typical poliovirus population through two rounds of passage. Our results show that this economical platform can be used to investigate dynamic changes occurring at frequencies below 1% within a complex nucleic acid population. Given that many key aspects of the study and treatment of disease are intimately linked to population-level genomic diversity, our SBE-based technique provides a scalable and cost-effective complement to both traditional and next generation sequencing methodologies

Seasonal drought limits tree species across the Neotropics

AcceptedArticle in Press© 2016 Nordic Society Oikos.Within the tropics, the species richness of tree communities is strongly and positively associated with precipitation. Previous research has suggested that this macroecological pattern is driven by the negative effect of water-stress on the physiological processes of most tree species. This implies that the range limits of taxa are defined by their ability to occur under dry conditions, and thus in terms of species distributions predicts a nested pattern of taxa distribution from wet to dry areas. However, this 'dry-tolerance' hypothesis has yet to be adequately tested at large spatial and taxonomic scales. Here, using a dataset of 531 inventory plots of closed canopy forest distributed across the western Neotropics we investigated how precipitation, evaluated both as mean annual precipitation and as the maximum climatological water deficit, influences the distribution of tropical tree species, genera and families. We find that the distributions of tree taxa are indeed nested along precipitation gradients in the western Neotropics. Taxa tolerant to seasonal drought are disproportionally widespread across the precipitation gradient, with most reaching even the wettest climates sampled; however, most taxa analysed are restricted to wet areas. Our results suggest that the 'dry tolerance' hypothesis has broad applicability in the world's most species-rich forests. In addition, the large number of species restricted to wetter conditions strongly indicates that an increased frequency of drought could severely threaten biodiversity in this region. Overall, this study establishes a baseline for exploring how tropical forest tree composition may change in response to current and future environmental changes in this region.This paper is a product of the RAINFOR and ATDN networks and of ForestPlots.net researchers (http://www.forestplots.net). RAINFOR and ForestPlots have been supported by a Gordon and Betty Moore Foundation grant, the European Union’s Seventh Framework Programme (283080, ‘GEOCARBON’; 282664, ‘AMAZALERT’); European Research Council (ERC) grant ‘Tropical Forests in the Changing Earth System’ (T-FORCES), and Natural Environment Research Council (NERC) Urgency Grant and NERC Consortium Grants ‘AMAZONICA’ (NE/F005806/1) and ‘TROBIT’ (NE/D005590/1). Additional funding for fieldwork was provided by Tropical Ecology Assessment and Monitoring (TEAM) Network, a collaboration among Conservation International, the Missouri Botanical Garden, the Smithsonian Institution, and the Wildlife Conservation Society. A.E.M. receives a PhD scholarship from the T-FORCES ERC grant. O.L.P. is supported by an ERC Advanced Grant and a Royal Society Wolfson Research Merit Award. We thank Jon J. Lloyd, Chronis Tzedakis, David Galbraith, and two anonymous reviewers for helpful comments and Dylan Young for helping with the analyses. This study would not be possible without the extensive contributions of numerous field assistants and rural communities in the Neotropical forests. Alfredo Alarcón, Patricia Alvarez Loayza, Plínio Barbosa Camargo, Juan Carlos Licona, Alvaro Cogollo, Massiel Corrales Medina, Jose Daniel Soto, Gloria Gutierrez, Nestor Jaramillo Jarama, Laura Jessica Viscarra, Irina Mendoza Polo, Alexander Parada Gutierrez, Guido Pardo, Lourens Poorter, Adriana Prieto, Freddy Ramirez Arevalo, Agustín Rudas, Rebeca Sibler and Javier Silva Espejo additionally contributed data to this study though their RAINFOR participations. We further thank those colleagues no longer with us, Jean Pierre Veillon, Samuel Almeida, Sandra Patiño and Raimundo Saraiva. Many data come from Alwyn Gentry, whose example has inspired new generations to investigate the diversity of the Neotropics