620 resultados para colony collpase disorder


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Nosema ceranae is an emergent and potentially virulent pathogen of the honey bee (Apis mellifera) that has spread across the world in the last 10 or so years. Its precise origin and timing of spread are currently unclear because of a lack of appropriate genetic markers and inadequate sampling in putative Asian source populations. Though it has been dismissed as a cause of CCD in the USA based on correlational analyses of snapshot sampling of diseased hives, observations of naturally infected colonies suggest that it leads to colony collapse in Spain. Experiments are sorely needed to investigate its impact on individuals and colonies, and to pin down a causal relationship between N. ceranae and colony collapse. Whether N. ceranae is displacing N. apis is uncertain. For temperate zone apiculturalists, global climate change may mean that N. ceranae presents more of a challenge than has hitherto been considered the case.

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The purpose of the current research project is to design a successful in-situ hybridization to identify regions within the brains of honeybees where DWV replicates. The localization of the virus in the brains of the bees can draw a connection between CCDand DWV.In conclusion, these results demonstrate that in bees infected with DWV the virus replicates actively in very important regions of the brain, including neuropils that are responsible for vision and olfaction. This means that the virus could adversely affect the vision and olfaction of the honeybees making it difficult for bees to behave normally.

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Understanding the fundaments of colony losses and improving the status of colony health will require cross-cutting research initiatives including honeybee pathology, chemistry, genetics and apicultural extension. The 7th framework of the European Union requested research to empirically and experimentally fill knowledge gaps on honeybee pests and diseases, including 'Colony Collapse Disorder' and the impact of parasites, pathogens and pesticides on honeybee mortality. The interactions among these drivers of colony loss will be studied in different European regions, using experimental model systems including selected parasites (e. g. Nosema and Varroa mites), viruses (Deformed Wing Virus, Black Queen Cell Virus, Israeli Acute Paralysis Virus) and model pesticides (thiacloprid, tau-fluvalinate). Transcriptome analyses will be used to explore host-pathogen-pesticide interactions and identify novel genes for disease resistance. Special attention will be given to sublethal and chronic exposure to pesticides and will screen how apicultural practices affect colony health. Novel diagnostic screening methods and sustainable concepts for disease prevention will be developed resulting in new treatments and selection tools for resistant stock. Research initiatives will be linked to various national and international ongoing European, North-and South-American colony health monitoring and research programs, to ensure a global transfer of results to apicultural practice in the world community of beekeepers.

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Accounting for biodiversity has received increasing attention from the academic accounting community in recent years. Despite a stream of research investigating the quality and quantity of biodiversity reporting in general, no academic research has focused on reporting related to one specific species. This paper explores the quality and quantity of corporate disclosures relating to bees. Society is becoming increasingly concerned about the accelerating fall in bee populations around the world. Colony Collapse Disorder has been spreading through global bee populations since 2006, decimating commercial hives. Concerns are fuelled by fears that pollinators may become extinct which would have dire consequences for the majority of world food production, leaving human pollination, at immense cost, the only alternative. On the basis of these fears, companies as well as other organisations, have started to establish programmes aimed at rejuvenating global bee populations. In this paper we explore the bee-related disclosures provided by a large selection of UK listed companies. We assess the extent to which companies believe they have a role to play in enhancing and protecting bee populations. Further we consider whether corporate accountability in this area derives solely from a business case or whether there is a deeper societal connection with bees as a species which is encouraging companies to protect their survival. The paper investigates the historical and philosophical connection between bees and human beings, for example the ways industrial production has been likened to honey production. We draw parallels between bees and human industrial organisation as well as between the role and responsibilities of the bookkeeper and the beekeeper.

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Os ácaros ectoparasitas Varroa destructor, que parasitam as abelhas tornaram-se um problema global. Embora seja pouco provável que estes ácaros, por si só, provoquem a mortalidade das colmeias, eles desempenham um importante papel como vetor de muitas doenças virais. E estas doenças são identificados como algumas das mais importantes razões para a Desordem do Colapso das Colônias. Os efeitos da infestação do V.destructor são distintas em diferentes partes do mundo. Maiores mortalidades de colônias têm sido relatadas em colônias de abelhas européias (AE) em países da Europa, Ásia e América do Norte. No entanto, este ácaro está presente no Brasil já por muitos anos e não existem relatos de perdas em colônias das abelhas africanizadas (AA). Estudos realizados no México mostraram que alguns comportamentos de resistência ao ácaro Varroa - especialmente o grooming e o comportamento higiênico - são diferentes em cada uma das subespécie. Poderiam então esses mecanismos explicar por que as abelhas africanizadas são menos suscetíveis à Desordem do Colapso das Colônias? A fim de responder a esta pergunta, propomos um modelo matemático baseado em equações diferenciais, com o objetivo de analisar o papel desses mecanismos de resistência na saúde geral da colônia e na capacidade da colônia para enfrentar desafios ambientais.

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Bees have a crucial role in pollination; therefore, it is important to determine the causes of their recent decline. Fipronil and imidacloprid are insecticides used worldwide to eliminate or control insect pests. Because they are broad-spectrum insecticides, they can also affect honeybees. Many researchers have studied the lethal and sublethal effects of these and other insecticides on honeybees, and some of these studies have demonstrated a correlation between the insecticides and colony collapse disorder in bees. The authors investigated the effects of fipronil and imidacloprid on the bioenergetic functioning of mitochondria isolated from the heads and thoraces of Africanized honeybees. Fipronil caused dose-dependent inhibition of adenosine 5'-diphosphate-stimulated (state 3) respiration in mitochondria energized by either pyruvate or succinate, albeit with different potentials, in thoracic mitochondria; inhibition was strongest when respiring with complex I substrate. Fipronil affected adenosine 5'-triphosphate (ATP) production in a dose-dependent manner in both tissues and substrates, though with different sensitivities. Imidacloprid also affected state-3 respiration in both the thorax and head, being more potent in head pyruvate-energized mitochondria; it also inhibited ATP production. Fipronil and imidacloprid had no effect on mitochondrial state-4 respiration. The authors concluded that fipronil and imidacloprid are inhibitors of mitochondrial bioenergetics, resulting in depleted ATP. This action can explain the toxicity of these compounds to honeybees. (c) 2014 SETAC

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Apis mellifera L., the European honeybee, is a crucial pollinator of many important agricultural crops in the United States. Recently, honeybee colonies have been affected by Colony Collapse Disorder (CCD), a disorder in which the colony fails due to the disappearance of a key functional group of worker bees. Though no direct causalrelationship has been confirmed, hives that experience CCD have been shown to have a high incidence of Deformed Wing Virus (DWV), a common honeybee virus. While the genome sequence and gene-order of DWV has been analyzed fairly recently, few other studies have been performed to understand the molecular characterization of the virus.Since little is known about where DWV proteins localize in infected host cells, the objective of this project was to determine the subcellular localization of two of the important non-structural proteins that are encoded in the DWV genome. This project focused on the protein 3C, an autocatalytic protease which cleaves itself from a longer polyprotein and helps to cut all of the other proteins apart from one another so that they can become functional, and 3D, the RNA-dependent RNA polymerase (RdRp) which is critical for replication of the virus because it copies the viral genome. By tagging nested constructs containing these two proteins and tracking where they localized in living cells, this study aimed to better understand the replication of DWV and to elicit possible targetsfor further research on how to control the virus. Since DWV is a picorna-like virus, distantly related to human viruses such as polio, and picornavirus non-structural proteins aggregate at cellular membranes during viral replication, the major hypothesis was that the 3C and 3CD proteins would localize at cellular organelle membranes as well. Using confocal microscopy, both proteins were found to localize in the cytoplasm, but the 3CDprotein was found to be mostly diffuse cytoplasmic, and the 3C protein was found to localize more specifically on membranous structures just outside of the nucleus.

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Objective: This study aimed to investigate rates of psychiatric disorder in human immunodeficiency virus (HIV) infection, in an Australian sample of homosexual and bisexual men. Method: A cross-sectional study of a total of 65 HIV sero-negative (HIV-) and 164 HIV sero-positive men (HIVt) (79 CDC stage 1 1/1 11 and 85 CDC stage IV) was conducted in three centres. Lifetime and current prevalence rates of psychiatric disorder were evaluated using the Diagnostic Interview Schedule Version lllR (DIS-IIIR). Results: Elevated current and lifetime rates of major depression were detected in both HIV negative and HIV positive homosexual/bisexual men. Lifetime rates of alcohol abuseldependence were significantly elevated in HIV positive men (CDC group IV) when compared with HIV negative men. Among the HIV positive group the majority of psychiatric disorders detected were preceded by a pre-HIV diagnosis of psychiatric disorder. Major depression represented the disorder most likely to have first onset after HIV infection diagnosis. Conclusions: Lifetime rates of major depression were elevated in this sample of HIV-negative and HIV-positive men, In the HIV-positive men, psychiatric disorder was significantly associated with the presence of lifetime psychiatric disorder prior to HIV infection diagnosis, The findings indicate the importance of evaluation of psychiatric history prior to HIV infection and the clinical significance of depressive syndromes in this population.

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This study investigated the psychological impact of HIV infection through assessment of posttraumatic stress disorder in response to HIV infection. Sixty-one HIV-positive homosexual/bisexual men were assessed for posttraumatic stress disorder in response to HIV infection (PTSD-HIV) using a modified PTSD module of the DIS-III-R. Thirty percent met criteria for a syndrome of posttraumatic stress disorder in response to HIV diagnosis (PTSD-HIV). In over one-third of the PTSD cases, the disorder had an onset greater than 6 months after initial HIV infection diagnosis. PTSD-HIV was associated with other psychiatric diagnoses, particularly the development of first episodes of major depression after HIV infection diagnosis. PTSD-HIV was significantly associated with a pre-HIV history of PTSD from other causes, and other pre-HIV psychiatric disorders and neuroticism scores, indicating a similarity with findings in studies of PTSD from other causes. The findings from this preliminary study suggest that a PTSD response to HIV diagnosis has clinical validity and requires further investigation in this population and other medically ill groups. The results support the inclusion of the diagnosis of life-threatening illness as a traumatic incident that may lead to a posttraumatic stress disorder, which is consistent with the DSM-IV criteria.