53 research outputs found

    Quantitative real time PCR assay for detecting EBV virus in multiple sample types.

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    PosterWe are developing a real time quantitative PCR assay to detect EBV in serum, plasma, whole blood, tissue and spinal fluid. Real time PCR, with its intrinsic quantitative capacity, is an excellent method for measuring EBV viral load. Epstein Barr virus is a member of the Herpesvirus family, with a tropism for B lymphocytes, where it establishes latency. In transplant settings, it causes post transplantation lymphoproliferative isorder (PTLD). High doses of immunosuppressive drugs allow the virus to escape the immune system, which normally keeps the latent virus in check. Symptoms of PTLD can mimic those of organ rejection, leading to increased immunosuppression, when a decrease in dosage is actually necessary. The primers and probes for this assay are supplied by Epoch/Nanogen and target a region of the BNFR1 gene. This EBV assay design has the probe-binding site overlapping one of the primer binding sites by five nucleotides. Dilutions of a plasmid containing the cloned amplicon are used as standards. A new standard curve is generated and stored with each new lot of EBV reagents or Taq polymerase. Sequestration of reagent lots and the lyophilization of control material have been shown to help maintain stability of assay performance over the period that a stored standard curve is being used. A plasmid internal control is included in the sample extraction to detect PCR inhibition and extraction failures

    Quantitative real time PCR assay for detecting BK virus in serum, plasma and urine.

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    PosterBK is a non-enveloped virus in the Polyomavirus family, closely related to SV40 and JC virus. Primary infection with BK generally occurs during childhood without specific symptoms, and is widespread in the population, with approximately 80% of adults infected globally. The virus remains latent in the urogenital tract, but can become transplant patients,reactivated. Asymptomatic reactivation and sporadic shedding of BK virus in urine can happen spontaneously in immunocompetant patients

    Sustainable Agriculture for Alaska and the Circumpolar North: Part III. Meeting the Challenges of High-Latitude Farming

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    Agriculture is a severely underdeveloped industry in Alaska and throughout most of the Subarctic. Growers and entrepreneurs must overcome a diverse set of challenges to achieve greater sustainability in northern communities where resilience is threatened by food insecurity and challenges to northern agriculture have limited the industry. However, several field-based or social policy solutions to problems of high-latitude agriculture have been proposed or are being put into practice. Field-based solutions include the use of special infrastructure or farm management strategies to extend the short growing season, improve soil quality, integrate appropriate pest and irrigation management practices, and further develop the livestock sector. Social and policy solutions are resolutions or decisions reached by stakeholders and government, often through cooperative interaction and discussion. These solutions stem from meaningful discussion and decision making among community members, organizations, agencies, and legislators. Social and policy solutions for Alaska include addressing the high costs of land and the preservation of agricultural lands; improved markets and market strategies; more appropriate funding for research, education and infrastructure; and other integrative or cooperative efforts. Collectively, these solutions will work to improve the outlook for sustainable agriculture in Alaska.En Alaska et dans une grande partie des régions subarctiques, l’agriculture est une industrie extrêmement sous-développée. Les producteurs et les entrepreneurs doivent surmonter un ensemble de défis variés pour donner lieu à une plus grande durabilité dans les collectivités nordiques, là où la résilience est menacée par l’insécurité alimentaire et où les défis caractérisant l’agriculture nordique imposent des restrictions à l’industrie. Cependant, plusieurs solutions apportées sur le terrain ou par le biais de politiques sociales vis-à-vis des problèmes touchant l’agriculture en haute latitude ont été proposées ou sont en train d’être mises en pratique. Parmi les solutions apportées sur le terrain, notons le recours à une infrastructure particulière ou à des stratégies de gestion agricole visant à prolonger la courte saison de croissance, à améliorer la qualité du sol, à intégrer des méthodes de gestion de l’irrigation et des organismes nuisibles, et à mettre davantage l’accent sur le secteur de l’élevage du bétail. Les solutions en matière de politiques sociales prennent la forme de résolutions ou de décisions prises par les parties prenantes et le gouvernement, souvent en collaboration et à la lumière de discussions. Ces solutions découlent de discussions et de prises de décisions importantes entre les membres des collectivités, les organisations, les agences et les législateurs. Les solutions de politiques sociales de l’Alaska portent notamment sur le coût élevé de la terre et la conservation des terres agricoles, sur l’amélioration des marchés et des stratégies de commercialisation, sur la nécessité d’obtenir des sources de financement plus adéquates pour la recherche, l’éducation et l’infrastructure, ainsi que sur d’autres efforts d’intégration et de coopération. Ensemble, ces solutions permettront d’améliorer la conjoncture de l’agriculture durable en Alaska

    Sustainable Agriculture for Alaska and the Circumpolar North: Part II. Environmental, Geophysical, Biological and Socioeconomic Challenges

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    Local agriculture, food security and food supply are limited in Alaska, as well as in much of the circumpolar North. These limitations stem from a suite of challenges that have never been well characterized, categorized, or wholly defined. We identify these challenges as being environmental, geophysical, biological, or socioeconomic in nature, noting that some challenges are interrelated. Additionally, Alaska is expansive, and growing conditions are highly variable across different regions and microclimates of the state. Environmental challenges to Alaskan agriculture are generally linked to high latitude and include strong seasonality, a short growing season, cold temperatures, and unpredictable frosts. Geophysical challenges are characterized by a high percentage of soils that are wet and cold or low in natural fertility. Biological challenges include cultivar adaptability and selection; the control of various pests, weeds, and diseases; and decreased microbial activity in cold soils, which can allow pesticides to linger and slow mineralization of organic fertilizers. Socioeconomic challenges to farming in Alaska are especially limiting and may categorically represent the strongest hindrances to agriculture. They often overlap or interact with many of the identified agro-ecological and biogeographic challenges. Major socioeconomic issues can be a relatively low financial incentive or reward for farmers; inconsistent or limited markets; the high cost of land, infrastructure, and inputs; zoning challenges; a lack of cooperatives; and for rural farmers, time conflicts with more traditional means of subsistence food acquisition. These challenges collectively represent factors that limit agriculture in Alaska, and they provide a basis and justification for developing more sustainable solutions. agriculture; Alaska; challenges; climate; circumpolar; farming; soils; subarctic; sustainable; socioeconomicEn Alaska, l’agriculture locale, la sécurité alimentaire et les approvisionnements en vivres sont limités. C’est également le cas d’une grande partie du Nord circumpolaire. Ces limitations découlent d’un ensemble de défis qui n’ont jamais été bien caractérisés, catégorisés ou entièrement définis. Nous estimons que ces défis sont d’ordre environnemental, géophysique, biologique ou socioéconomique, et que certains des défis sont interreliés. De plus, l’Alaska est d’une grande étendue, et les conditions de croissance varient énormément d’une région à l’autre et d’un microclimat à l’autre de l’État. De manière générale, les défis environnementaux inhérents à l’agriculture alaskienne ont trait à la haute latitude, ce qui comprend une importante saisonnalité, une courte saison de croissance, des températures froides et des gelées imprévisibles. Pour leur part, les défis géophysiques sont caractérisés par un fort pourcentage de sols humides et froids, ou encore, de sols dont la fertilité naturelle est faible, puis les défis d’ordre biologique ont trait à l’adaptabilité et à la sélection des cultivars, à la lutte contre divers organismes nuisibles, les mauvaises herbes et les maladies, ainsi qu’à une activité microbienne réduite dans les sols froids, ce qui permet aux pesticides de rester plus longtemps et ralentit la minéralisation des engrais organiques. Quant aux défis de nature socioéconomique, ils imposent des restrictions particulièrement fortes en Alaska, au point où ils pourraient même catégoriquement représenter le plus grand obstacle à l’agriculture. Dans bien des cas, les défis se chevauchent ou ont une action réciproque sur un grand nombre d’enjeux agroécologiques et biogéographiques. De plus, les grands enjeux socioéconomiques peuvent prendre la forme de récompenses financières relativement faibles pour les agriculteurs, de marchés irréguliers ou limités, du coût élevé de la terre, des infrastructures et des intrants, d’obstacles inhérents au zonage, d’un manqué de coopératives et, dans le cas des agriculteurs ruraux, de conflits d’emploi du temps avec les moyens de subsistance plus traditionnels d’acquisition de la nourriture. Collectivement, ces défis représentent les facteurs qui imposent des restrictions à l’agriculture en Alaska, et ils constituent les fondements et la justification nécessaires au développement de solutions plus durables

    Chemokine Binding Protein M3 of Murine Gammaherpesvirus 68 Modulates the Host Response to Infection in a Natural Host

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    Murine γ-herpesvirus 68 (MHV-68) infection of Mus musculus-derived strains of mice is an attractive model of γ-herpesvirus infection. Surprisingly, however, ablation of expression of MHV-68 M3, a secreted protein with broad chemokine-binding properties in vitro, has no discernable effect during experimental infection via the respiratory tract. Here we demonstrate that M3 indeed contributes significantly to MHV-68 infection, but only in the context of a natural host, the wood mouse (Apodemus sylvaticus). Specifically, M3 was essential for two features unique to the wood mouse: virus-dependent inducible bronchus-associated lymphoid tissue (iBALT) in the lung and highly organized secondary follicles in the spleen, both predominant sites of latency in these organs. Consequently, lack of M3 resulted in substantially reduced latency in the spleen and lung. In the absence of M3, splenic germinal centers appeared as previously described for MHV-68-infected laboratory strains of mice, further evidence that M3 is not fully functional in the established model host. Finally, analyses of M3's influence on chemokine and cytokine levels within the lungs of infected wood mice were consistent with the known chemokine-binding profile of M3, and revealed additional influences that provide further insight into its role in MHV-68 biology

    Novel insights into the aetiology and pathophysiology of increased airway inflammation during COPD exacerbations

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    Airway inflammation increases during acute exacerbations of COPD. Extrinsic factors, such as airway infections, increased air pollution, and intrinsic factors, such as increased oxidative stress and altered immunity may contribute to this increase. The evidence for this and the potential mechanisms by which various aetiological agents increase inflammation during COPD exacerbations is reviewed. The pathophysiologic consequences of increased airway inflammation during COPD exacerbations are also discussed. This review aims to establish a cause and effect relationship between etiological factors of increased airway inflammation and COPD exacerbations based on recently published data. Although it can be speculated that reducing inflammation may prevent and/or treat COPD exacerbations, the existing anti-inflammatory treatments are modestly effective

    Consistent patterns of common species across tropical tree communities

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    Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe

    Consistent patterns of common species across tropical tree communities

    Get PDF
    Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees

    Consistent patterns of common species across tropical tree communities

    Get PDF
    Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees

    Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

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    Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome
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