994 resultados para Apis mellftra
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Ibuprofen (IB), a BCS Class II compound, is a highly crystalline substance with poor solubility properties. Here we report on the disruption of this crystalline structure upon intimate contact with the polymeric carrier cross-linked polyvinylpyrrolidone (PVP-CL) facilitated by low energy simple mixing. Whilst strong molecular interactions between APIs and carriers within delivery systems would be expected on melting or through solvent depositions, this is not the case with less energetic mixing. Simple mixing of the two compounds resulted in a significant decrease in the differential scanning calorimetry (DSC) melting enthalpy for IB, indicating that approximately 30% of the crystalline content was disordered. This structural change was confirmed by broadening and intensity diminution of characteristic IB X-ray powder diffractometry (PXRD) peaks. Unexpectedly, the crystalline content of the drug continued to decrease upon storage under ambient conditions. The molecular environment of the mixture was further investigated using Fourier transform infrared (FT-IR) and Fourier transform Raman (FT-Raman) spectroscopy. These data suggest that the primary interaction between these components of the physical mix is hydrogen bonding, with a secondary mechanism involving electrostatic/hydrophobic interactions through the IB benzene ring. Such interactions and subsequent loss of crystallinity could confer a dissolution rate advantage for IB. (C) 2006 Elsevier B.V. All rights reserved.
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Pollination is one of the most important ecosystem services in agroecosystems and supports food production. Pollinators are potentially at risk being exposed to pesticides and the main route of exposure is direct contact, in some cases ingestion, of contaminated materials such as pollen, nectar, flowers and foliage. To date there are no suitable methods for predicting pesticide exposure for pollinators, therefore official procedures to assess pesticide risk are based on a Hazard Quotient. Here we develop a procedure to assess exposure and risk for pollinators based on the foraging behaviour of honeybees (Apis mellifera) and using this species as indicator representative of pollinating insects. The method was applied in 13 European field sites with different climatic, landscape and land use characteristics. The level of risk during the crop growing season was evaluated as a function of the active ingredients used and application regime. Risk levels were primarily determined by the agronomic practices employed (i.e. crop type, pest control method, pesticide use), and there was a clear temporal partitioning of risks through time. Generally the risk was higher in sites cultivated with permanent crops, such as vineyard and olive, than in annual crops, such as cereals and oil seed rape. The greatest level of risk is generally found at the beginning of the growing season for annual crops and later in June–July for permanent crops.
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Pollination services are known to provide substantial benefits to human populations and agriculture in particular. Although many species are known to provide pollination services, honeybees (Apis mellifera) are often assumed to provide the majority of these services to agriculture. Using data from a range of secondary sources, this study assesses the importance of insect pollinated crops at regional and national scales and investigates the capacity of honeybees to provide optimal pollination services to UK agriculture. The findings indicate that insect pollinated crops have become increasingly important in UK crop agriculture and, as of 2007, accounted for 20% of UK cropland and 19% of total farmgate crop value. Analysis of honeybee hive numbers indicates that current UK populations are only capable of supplying 34% of pollination service demands even under favourable assumptions, falling from 70% in 1984. In spite of this decline, insect pollinated crop yields have risen by an average of 54% since 1984, casting doubt on long held beliefs that honeybees provide the majority of pollination services. Future land use and crop production patterns may further increase the role of pollination services to UK agriculture, highlighting the importance of measures aimed at maintaining both wild and managed species.
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1. Pollinating insects provide crucial and economically important ecosystem services to crops and wild plants, but pollinators, particularly bees, are globally declining as a result of various driving factors, including the prevalent use of pesticides for crop protection. Sublethal pesticide exposure negatively impacts numerous pollinator lifehistory traits, but its influence on reproductive success remains largely unknown. Such information is pivotal, however, to our understanding of the long-term effects on population dynamics. 2 We investigated the influence of field-realistic trace residues of the routinely used neonicotinoid insecticides thiamethoxam and clothianidin in nectar substitutes on the entire life-time fitness performance of the red mason bee Osmia bicornis. 3 We show that chronic, dietary neonicotinoid exposure has severe detrimental effects on solitary bee reproductive output. Neonicotinoids did not affect adult bee mortality; however, monitoring of fully controlled experimental populations revealed that sublethal exposure resulted in almost 50% reduced total offspring production and a significantly male-biased offspring sex ratio. 4 Our data add to the accumulating evidence indicating that sublethal neonicotinoid effects on non-Apis pollinators are expressed most strongly in a rather complex, fitness-related context. Consequently, to fully mitigate long-term impacts on pollinator population dynamics, present pesticide risk assessments need to be expanded to include whole life-cycle fitness estimates, as demonstrated in the present study using O. bicornis as a model.
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Over the past 50 years, many millions of European honey bee (Apis mellifera) colonies have died as the ectoparasitic mite, Varroa destructor, has spread around the world. Subsequent studies have indicated that the mite's association with a group of RNA viral pathogens (Deformed Wing Virus, DWV) correlates with colony death. Here, we propose a phenomenon known as superinfection exclusion that provides an explanation of how certain A. mellifera populations have survived, despite Varroa infestation and high DWV loads. Next-generation sequencing has shown that a non-lethal DWV variant 'type B' has become established in these colonies and that the lethal 'type A' DWV variant fails to persist in the bee population. We propose that this novel stable host-pathogen relationship prevents the accumulation of lethal variants, suggesting that this interaction could be exploited for the development of an effective treatment that minimises colony losses in the future.The ISME Journal advance online publication, 27 October 2015; doi:10.1038/ismej.2015.186.
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Stingless bee honey samples were evaluated by sensory descriptive analysis using free choice profile methodology. Appearance, flavor, and aroma were described and the data were treated with Generalized Procrustes Analysis. Individual descriptive terms ranged from 8 to 20. Plotting the samples in a bidimensional plan indicated that appearance attributes (color and viscosity) and sweet, sour and acid flavor were strongly correlated with x axis (Dimension 1) while coconut, wood, acid, sour, and sweet flavor aroma attributes were correlated with y axis (Dimension 2). The affective test was also performed and with the exception of the Melipona scutellaris honey, all the other samples showed good acceptance. Honeys that were described as sweeter and less acid were preferred by nontrained assessors, indicating that the regular consumer recognizes honey produced by Apis mellifera bee as a standard.
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Stingless bees (Meliponini) constitute a diverse group of highly eusocial insects that occur throughout tropical regions around the world. The meliponine genus Melipona is restricted to the New World tropics and has over 50 described species. Melipona, like Apis, possesses the remarkable ability to use representational communication to indicate the location of foraging patches. Although Melipona has been the subject of numerous behavioral, ecological, and genetic studies, the evolutionary history of this genus remains largely unexplored. Here, we implement a multigene phylogenetic approach based on nuclear, mitochondrial, and ribosomal loci, coupled with molecular clock methods, to elucidate the phylogenetic relationships and antiquity of subgenera and species of Melipona. Our phylogenetic analysis resolves the relationship among subgenera and tends to agree with morphology-based classification hypotheses. Our molecular clock analysis indicates that the genus Melipona shared a most recent common ancestor at least similar to 14-17 million years (My) ago. These results provide the groundwork for future comparative analyses aimed at understanding the evolution of complex communication mechanisms in eusocial Apidae. (C) 2010 Elsevier Inc. All rights reserved.
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We see today many efforts to quantify biodiversity in different biomes. It is very important then to develop and to apply other methodologies that allow us to assess biodiversity. Here we present an example of application of three tools with this goal. We analyzed two populations of Plebeia remota from two distinct biomes that already showed several differences in morphology and behavior. Based on these differences, it has been suggested that the populations of Cunha and Prudentopolis do not represent a single species. In order to verify the existence or absence of gene flow between these two groups, we characterized the patterns of mtDNA through RFLP, the patterns of wing venation through geometric morphometry, and the cuticular hydrocarbons through gas chromatography-mass spectrometry. We used bees collected in these two locations and also from colonies which have being kept for around 9 years at Sao Paulo University. We found six different haplotypes in these specimens, of which three of them occurred exclusively in the population of Cunha and three only in the Prudentopolis population. The fact that the populations do not share haplotypes suggests no maternal gene flow between them. The two populations were differentiated by the pattern of the wing veins. They also had different mixtures of cuticle hydrocarbons. Furthermore it was shown that the colonies kept at the university did not hybridize. These two groups may constitute different species. We also show here the importance of using other methodologies than traditional taxonomy to assess and understand biodiversity, especially in bees.
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Interoperability of water quality data depends on the use of common models, schemas and vocabularies. However, terms are usually collected during different activities and projects in isolation of one another, resulting in vocabularies that have the same scope being represented with different terms, using different formats and formalisms, and published in various access methods. Significantly, most water quality vocabularies conflate multiple concepts in a single term, e.g. quantity kind, units of measure, substance or taxon, medium and procedure. This bundles information associated with separate elements from the OGC Observations and Measurements (O&M) model into a single slot. We have developed a water quality vocabulary, formalized using RDF, and published as Linked Data. The terms were extracted from existing water quality vocabularies. The observable property model is inspired by O&M but aligned with existing ontologies. The core is an OWL ontology that extends the QUDT ontology for Unit and QuantityKind definitions. We add classes to generalize the QuantityKind model, and properties for explicit description of the conflated concepts. The key elements are defined to be sub-classes or sub-properties of SKOS elements, which enables a SKOS view to be published through standard vocabulary APIs, alongside the full view. QUDT terms are re-used where possible, supplemented with additional Unit and QuantityKind entries required for water quality. Along with items from separate vocabularies developed for objects, media, and procedures, these are linked into definitions in the actual observable property vocabulary. Definitions of objects related to chemical substances are linked to items from the Chemical Entities of Biological Interest (ChEBI) ontology. Mappings to other vocabularies, such as DBPedia, are in separately maintained files. By formalizing the model for observable properties, and clearly labelling the separate concerns, water quality observations from different sources may be more easily merged and also transformed to O&M for cross-domain applications.
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Passiflora suberosa Linnaeus (Passifloraceae), uma espécie de maracujá nativa no Rio Grande do Sul, é estudada em relação à biologia reprodutiva e ao processo de polinização. As avaliações são realizadas em populações cultivadas de P. suberosa presentes em áreas urbanas no Munícipio de Porto Alegre, RS. Aspectos concernentes à biologia floral foram avaliadas em uma população do Campus do Vale(UFRGS). A observação e coleta dos visitantes florais foi realizada em um jardim residencial, no bairro Passo da Areia. Avalia-se o sistema reprodutivo de P. suberosa em condições de campo através de três tratamentos: xenogamia, autogamia espontânea e autogamia manual. Um grupo de flores é marcado e deixado em condições naturais(controle) para se observar a formação de frutos. O padrão de produção e o volume de néctor produzido foram observados em flores isoladas e amostradas a cada duas horas das 8 as 18 horas. O efeito provocado pela remoção intermitente de néctar foi avaliado nas mesmas flores. A quantidade diária de néctar produzida foi avaliada utilizando-se um novo conjunto de flores a cada amostragem Para verificar o padrão de disponibilização diária de pólen, amostrou-se flores isoladas a cada 30 minutos, das 7 às 14 horas. Similarmente, flores não isoladas foram avaliadas para determinar quanto tempo o pólen permanece disponível na presença dos visitantes florais.A receptividade do estigma foi testada in vivo, por meio de polinização manual em flores emasculadas, das 8 até às 18 horas. Os visitantes florais foram monitorados de dezembro de 2001 a novembro de 2002.Observações seguidas de coleta foram realizadas a cada quinze dias, no período entre as 8 e as 14 horas. Nessas ocasiões, as flores abertas foram contadas e registrava-se a posição das pétalas, anteras e estigmas. Os visitantes florais foram observados em relação a hora da visita, contato com anteras e/ou estigmas, partes do corpo que contava as estruturas reprodutivas, presença de pólen no corpo e taxa de visita Os grãos de pólen aderidos no dorso dos insetos foram montados em lâminas microscópicas e analisadas em laboratório. Os resotados indicam que P. suberosa é autocompatível, entretanto a autofecundação espontânea não parece ser freqüente devido a posição das anteras e estigmas na flor. O polén não é disponibilizado de forma gradual, devido ao fato das cinco anteras de uma mesma flor tornarem-se deiscentes em tempos diferentes, desde a abertura da flor até o final da manhã, período em que todo o pólen está disponível. O número de flores com estigmas receptivos na população variou durante o dia, sendo o período entre 10 e 15 horas aquele em que se observou o maior número de flores receptivas. As flores P. suberosa já abriram com algum néctar disponível e continuaram produzindo. As 10 horas observou-se o volume máximo de néctar produzido durante o dia. As folhas foram visitadas principalmente por Polybia ignobilis, Pachodynerus guadulpensis, Polistes versicolor, Polistes cavapytiformis (Vespidae), por Augochloropsis sp. e Augochlorella ephyra (halictidae) e por Apis mellifera(Apidae). Ainda que todos os visitantes florais amostrados possam polinizar as flores, Polybia ignobilis, dado os seus atributos morfológicos, padrão comportamental de forrageio e a grande quantidade de pólen amostrada sobre a região dorsal do tórax, foi aquela que efetivamente contribuiu para a polinização da população de P. suberosa estudada.
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Computação Móvel é um termo genérico, ainda em definição, ao redor do qual se delineia um espectro de cenários possíveis, desde a Computação Pessoal, com o uso de computadores de mão, até a visão futurista da Computação Ubíqua. O foco do projeto ISAM (Infra-estrutura de Suporte às Aplicações Móveis Distribuída), em desenvolvimento no II/UFRGS, é a Pervasive Computing. Esta desenha um cenário onde o usuário é livre para se deslocar mantendo o acesso aos recursos da rede e ao seu ambiente computacional, todo tempo em qualquer lugar. Esse novo cenário apresenta muitos desafios para o projeto e execução de aplicações. Nesse escopo, esta tese aprofunda a discussão sobre questões relativas à adaptação ao contexto em um ambiente pervasivo sob a ótica de uma Linguagem de Programação, e define uma linguagem chamada ISAMadapt. A definição da linguagem ISAMadapt baseia-se em quatro abstrações: contexto, adaptadores, políticas e comandos de adaptação. Essas abstrações foram concretizadas em duas visões: (1) em tempo de programação, através de comandos da linguagem e arquivos de configuração, descritos com o auxílio do Ambiente de Desenvolvimento de Aplicações; (2) em tempo de execução, através de serviços e APIs fornecidos pelos componentes que integram o ambiente de execução pervasiva (ISAMpe). Deste, os principais componentes que implementam a semântica de execução da aplicação ISAMadapt são: o serviço de reconhecimento de contexto, ISAMcontextService, e a máquina de execução da adaptação dinâmica, ISAMadaptEngine.As principais contribuições desta tese são: (a) primeira linguagem para a codificação de aplicações pervasivas; (b) sintaxe e semântica de comandos para expressar sensibilidade ao contexto pervasivo; (c) fonte para o desenvolvimento de uma metodologia de projeto de aplicações pervasivas; (d) projeto ISAM e o projeto contextS (www.inf.ufrgs.br/~isam) que fornecem suporte para o ciclo de vida das aplicações, desde o desenvolvimento até a execução de aplicações pervasivas.
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Este trabalho apresenta um sistema multiagente que permite simular execuções musicais em violão. Em uma execução musical no violão observam-se elementos distintos que, trabalhando em conjunto, produzem a sonoridade desejada pelo músico. Ou seja, as ações tomadas pelo violonista, através do sincronismo de suas mãos sobre o instrumento, influenciam diretamente na sonoridade obtida. A idéia básica deste trabalho é desenvolver uma comunidade de agentes que represente as entidades envolvidas em uma performance musical de violão. Quatro agentes foram identificados e modelados no contexto desta dissertação. São eles: Mão Esquerda (ME): Responsável pela execução dos acordes, ou seja, deve possuir o conhecimento de formação de acordes dada a afinação do instrumento bem como a interpretação das cifras que representam os acordes. Agente Mão Direita (MD): Responsável pelo ritmo impresso na música; Caixa de Som (CS): Permite que os usuários simplesmente escutem a composição, sem nenhuma (ou muito pouca) interferência na composição. Agente Solista (SL): Projetado somente para ler arquivos MIDI e enviar notas para o Agente Caixa de Som (CS). O conhecimento relativo ao reconhecimento das cifras, geração do acorde e posterior cálculo do desenho do acorde para um instrumento de corda foi encapsulado em duas bibliotecas que visam auxiliar no desenvolvimento de outros novos projetos que necessitem de funcionalidades similares. Ainda, são abordadas as questões da comunicação entre os agentes e componentes gráficos utilizados na captura de informações rítmicas. O material musical produzido pelo sistema está contido no CD-ROM em anexo, bem como a documentação das API’s.
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INTRODUCTION With the advent of Web 2.0, social networking websites like Facebook, MySpace and LinkedIn have become hugely popular. According to (Nilsen, 2009), social networking websites have global1 figures of almost 250 millions unique users among the top five2, with the time people spend on those networks increasing 63% between 2007 and 2008. Facebook alone saw a massive growth of 566% in number of minutes in the same period of time. Furthermore their appeal is clear, they enable users to easily form persistent networks of friends with whom they can interact and share content. Users then use those networks to keep in touch with their current friends and to reconnect with old friends. However, online social network services have rapidly evolved into highly complex systems which contain a large amount of personally salient information derived from large networks of friends. Since that information varies from simple links to music, photos and videos, users not only have to deal with the huge amount of data generated by them and their friends but also with the fact that it‟s composed of many different media forms. Users are presented with increasing challenges, especially as the number of friends on Facebook rises. An example of a problem is when a user performs a simple task like finding a specific friend in a group of 100 or more friends. In that case he would most likely have to go through several pages and make several clicks till he finds the one he is looking for. Another example is a user with more than 100 friends in which his friends make a status update or another action per day, resulting in 10 updates per hour to keep up. That is plausible, especially since the change in direction of Facebook to rival with Twitter, by encouraging users to update their status as they do on Twitter. As a result, to better present the web of information connected to a user the use of better visualizations is essential. The visualizations used nowadays on social networking sites haven‟t gone through major changes during their lifetimes. They have added more functionality and gave more tools to their users, but still the core of their visualization hasn‟t changed. The information is still presented in a flat way in lists/groups of text and images which can‟t show the extra connections pieces of information. Those extra connections can give new meaning and insights to the user, allowing him to more easily see if that content is important to him and the information related to it. However showing extra connections of information but still allowing the user to easily navigate through it and get the needed information with a quick glance is difficult. The use of color coding, clusters and shapes becomes then essential to attain that objective. But taking into consideration the advances in computer hardware in the last decade and the software platforms available today, there is the opportunity to take advantage of 3D. That opportunity comes in because we are at a phase were the hardware and the software available is ready for the use of 3D in the web. With the use of the extra dimension brought by 3D, visualizations can be constructed to show the content and its related information to the user at the same screen and in a clear way. Also it would allow a great deal of interactivity. Another opportunity to create better information‟s visualization presents itself in the form of the open APIs, specifically the ones made available by the social networking sites. Those APIs allow any developers to create their own applications or sites taking advantage of the huge amount of information there is on those networks. Specifically to this case, they open the door for the creation of new social network visualizations. Nevertheless, the third dimension is by itself not enough to create a better interface for a social networking website, there are some challenges to overcome. One of those challenges is to make the user understand what the system is doing during the interaction with the user. Even though that is important in 2D visualizations, it becomes essential in 3D due to the extra dimension. To overcome that challenge it‟s necessary the use of the principles of animations defined by the artists at Walt Disney Studios (Johnston, et al., 1995). By applying those principles in the development of the interface, the actions of the system in response to the user inputs became clear and understandable. Furthermore, a user study needs to be performed so the users‟ main goals and motivations, while navigating the social network, are revealed. Their goals and motivations are important in the construction of an interface that reflects the user expectations for the interface, but also helps in the development of appropriate metaphors. Those metaphors have an important role in the interface, because if correctly chosen they help the user understand the elements of the interface instead of making him memorize it. The last challenge is the use of 3D visualization on the web, since there have been several attempts to bring 3D into it, mainly with the various versions of VRML which were destined to failure due to the hardware limitations at the time. However, in the last couple of years there has been a movement to make the necessary tools to finally allow developers to use 3D in a useful way, using X3D or OpenGL but especially flash. This thesis argues that there is a need for a better social network visualization that shows all the dimensions of the information connected to the user and that allows him to move through it. But there are several characteristics the new visualization has to possess in order for it to present a real gain in usability to Facebook‟s users. The first quality is to have the friends at the core of its design, and the second to make use of the metaphor of circles of friends to separate users in groups taking into consideration the order of friendship. To achieve that several methods have to be used, from the use of 3D to get an extra dimension for presenting relevant information, to the use of direct manipulation to make the interface comprehensible, predictable and controllable. Moreover animation has to be use to make all the action on the screen perceptible to the user. Additionally, with the opportunity given by the 3D enabled hardware, the flash platform, through the use of the flash engine Papervision3D and the Facebook platform, all is in place to make the visualization possible. But even though it‟s all in place, there are challenges to overcome like making the system actions in 3D understandable to the user and creating correct metaphors that would allow the user to understand the information and options available to him. This thesis document is divided in six chapters, with Chapter 2 reviewing the literature relevant to the work described in this thesis. In Chapter 3 the design stage that resulted in the application presented in this thesis is described. In Chapter 4, the development stage, describing the architecture and the components that compose the application. In Chapter 5 the usability test process is explained and the results obtained through it are presented and analyzed. To finish, Chapter 6 presents the conclusions that were arrived in this thesis.
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Sea anemones contain a variety of biologically active substances. Bunodosoma caissarum is a sea anemone from the Cnidaria phylum, found only in Brazilian coastal waters. The aim of the present work was to study the biological effects of PLA(2) isolated from the sea anemone B. caissarum on the isolated perfused kidney, the arteriolar mesenteric bed and on insulin secretion. Specimens of B. caissarum were collected from the Sao Vicente Channel on the southern coast of the State of São Paulo, Brazil. Reverse phase HPLC analysis of the crude extract of B. caissarum detected three PLA(2) proteins (named BcPLA(2)1, BCPLA(2)2 and BcPLA(2)3) found to be active in B. caissarum extracts. MALDI-TOF mass spectrometry of BcPLA(2)1 showed one main peak at 14.7 kDa. The N-terminal amino acid sequence of BcPLA(2)1 showed high amino acid sequence identity with PLA(2) group III protein isolated from the Mexican lizard (PA23 HELSU, HELSU, PA22 HELSU) and with the honey bee Apis mellifera (PLA(2) and 1POC_A). In addition, BcPLA(2)1 also showed significant overall homology to bee PLA(2). The enzymatic activity induced by native BCPLA(2)1 (20 mu g/well) was reduced by chemical treatment with p-bromophenacyl bromide (p-BPB) and with morin. BcPLA(2)1 strongly induced insulin secretion in presence of high glucose concentration. In isolated kidney, the PLA(2) from B. caissarum increased the perfusion pressure, renal vascular resistance, urinary flow, glomerular filtration rate, and sodium, potassium and chloride levels of excretion. BcPLA(2)1, however, did not increase the perfusion pressure on the mesenteric vascular bed. In conclusion, PLA(2), a group III phospholipase isolated from the sea anemone B. caissarum, exerted effects on renal function and induced insulin secretion in conditions of high glucose concentration. (C) 2009 Elsevier Ltd. All rights reserved.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)