918 resultados para Commonwealth Scientific and Industrial Research Organisation
Resumo:
n recent years, declines of honey bee populations have received massive media attention worldwide, yet attempts to understand the causes have been hampered by a lack of standardisation of laboratory techniques. Published as a response to this, the COLOSS BEEBOOK is a unique collaborative venture involving 234 bee scientists from 34 countries, who have produced the definitive guide to how to carry out research on honey bees. It is hoped that these volumes will become the standards to be adopted by bee scientists worldwide. Volume II includes approximately 600 separate protocols dealing with the study of the pests and diseases of the honey bee, Apis mellifera. These cover epidemiology and surveying techniques, virus diseases, bacterial diseases such as European and American foulbrood, fungal and microsporidian diseases such as Nosema, mites such as Acarapis, Varroa and Tropilaelaps, and other pests such as the small hive beetle.
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Venous thromboembolism (VTE) is a potentially lethal clinical condition that is suspected in patients with common clinical complaints, in many and varied, clinical care settings. Once VTE is diagnosed, optimal therapeutic management (thrombolysis, IVC filters, type and duration of anticoagulants) and ideal therapeutic management settings (outpatient, critical care) are also controversial. Clinical prediction tools, including clinical decision rules and D-Dimer, have been developed, and some validated, to assist clinical decision making along the diagnostic and therapeutic management paths for VTE. Despite these developments, practice variation is high and there remain many controversies in the use of the clinical prediction tools. In this narrative review, we highlight challenges and controversies in VTE diagnostic and therapeutic management with a focus on clinical decision rules and D-Dimer.
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Environmental aspects are increasingly being integrated in Negev Bedouin studies by both, NGO activists and scholars. We will present these recent works and discuss new concepts and methodologies of environmental studies with potential relevance in the field of Negev Bedouin studies. We will then identify research areas where environmental and development approaches converge or diverge with mainstream social sciences on this specific field of research. While most of the Bedouin population in southern Israel lives in urban centers in the Northern Negev, a large part of Bedouin people live in unrecognized clusters of houses in remote areas. Extensive livestock rearing is an important source of livelihood at least for non-urbanized Bedouin, the latter forming the lowest economic strata of the Israeli spectrum of incomes. Numerous stressors affect this Bedouin community enduring uncertain livelihood and access to land. The erratic precipitations from year to year and long-term changes in precipitation trends are a source of great uncertainty. With a significant price increase for feeding supplements to compensate for dry years, livestock rearing has become a harsher source of livelihood. Land scarcity for grazing adds to the difficulty in ensuring enough income for living. Studies in the last 15 years have described several livelihood strategies based on a livestock rearing semi-nomadic economy in the Negev. A number of other analyses have shown how Bedouin herders and governmental agencies have found agreements at the advantage of both, the agencies and the herders. New concepts such as transformability, resilience and adaptation strategies are important tools to analyze the capacity of vulnerable communities to cope with an ever increasing livelihood uncertainty. Such research concepts can assist in better understanding how Bedouin herders in the Negev may adapt to climate and political risks.
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First indications of prehistoric sites in lakes of Switzerland go back more than 200 years and in 1854 Ferdinand Keller (1800-1881) published his famous book The Celtic Pile Dwellings in Swiss Lakes. Since these times, large-scale rescue excavations as well as survey and research projects have extended our knowledge about Neolithic and Bronze Age settlements in lakes, bogs and rivers around the European Alps. In 2011 a representative choice of 111 sites out of nearly 1000 in six countries around the Alps (Austria, France, Germany, Italy, Slovenia and Switzerland) were recognized by the UNESCO World Heritage committee as serial World Heritage. The lecture will give a general overview on prehistoric lake dwellings around the Alps (distribution, types of lakes/bogs and environment of sites, chronology/cultural units in the time scale 5300 to 800 BC) and present examples of well-documented settlement structures. The intense use of dendrochronological dating allowed the building up of a well-fixed chronological framework. In some cases dendrochronology is the basis for year-by-year reconstructions of prehistoric village biographies and detailed insights in the life cycle of early agrarian settlements. Beside these local events the grouped repartition of lake dwelling remains on the time scale makes a more global correlation between Holocene lake levels and the preservation of archaeological layers likely.
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BACKGROUND HIV-1 RNA viral load (VL) testing is recommended to monitor antiretroviral therapy (ART) but not available in many resource-limited settings. We developed and validated CD4-based risk charts to guide targeted VL testing. METHODS We modeled the probability of virologic failure up to 5 years of ART based on current and baseline CD4 counts, developed decision rules for targeted VL testing of 10%, 20%, or 40% of patients in 7 cohorts of patients starting ART in South Africa, and plotted cutoffs for VL testing on colour-coded risk charts. We assessed the accuracy of risk chart-guided VL testing to detect virologic failure in validation cohorts from South Africa, Zambia, and the Asia-Pacific. RESULTS In total, 31,450 adult patients were included in the derivation and 25,294 patients in the validation cohorts. Positive predictive values increased with the percentage of patients tested: from 79% (10% tested) to 98% (40% tested) in the South African cohort, from 64% to 93% in the Zambian cohort, and from 73% to 96% in the Asia-Pacific cohort. Corresponding increases in sensitivity were from 35% to 68% in South Africa, from 55% to 82% in Zambia, and from 37% to 71% in Asia-Pacific. The area under the receiver operating curve increased from 0.75 to 0.91 in South Africa, from 0.76 to 0.91 in Zambia, and from 0.77 to 0.92 in Asia-Pacific. CONCLUSIONS CD4-based risk charts with optimal cutoffs for targeted VL testing maybe useful to monitor ART in settings where VL capacity is limited.
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BACKGROUND There are no specific recommendations for the design and reporting of studies of children with fever and neutropenia (FN). As a result, there is marked heterogeneity in the variables and outcomes that are reported and new definitions continue to emerge. These inconsistencies hinder the ability of researchers and clinicians to compare, contrast and combine results. The objective was to achieve expert consensus on a core set of variables and outcomes that should be measured and reported, as a minimum, in pediatric FN studies. PROCEDURE The Delphi method was used to achieve consensus among an international group of clinicians, pharmacists, researchers, and patient representatives. Four surveys focusing on (i) the identification of a core set of variables and outcomes; and (ii) definitions of these variables and outcomes, were administered electronically. Consensus was predefined as more than 80% agreement on any statement. RESULTS There were forty-five survey participants and the response rate ranged between 84 and 96%. There was consensus on eight core variables and 10 core outcomes that should be collected and reported in all studies of children with FN. Consensus definitions were identified for all of the core outcomes. CONCLUSION Using the Delphi method, expert consensus on a set of core variables and outcomes, and their corresponding definitions, was achieved. These core sets represent the minimum that should be collected and reported in all studies of children with FN. This will promote collaboration and ensure consistency and comparability between studies.
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An accurate and efficient determination of the highly toxic Cr(VI) in solid materials is important to determine the total Cr(VI) inventory of contaminated sites and the Cr(VI) release potential from such sites into the environment. Most commonly, total Cr(VI) is extracted from solid materials following a hot alkaline extraction procedure (US EPA method 3060A) where a complete release of water-extractable and sparingly soluble Cr(VI) phase is achieved. This work presents an evaluation of matrix effects that may occur during the hot alkaline extraction and in the determination of the total Cr(VI) inventory of variably composed contaminated soils and industrial materials (cement, fly ash) and is compared to water-extractable Cr(VI) results. Method validation including multiple extractions and matrix spiking along with chemical and mineralogical characterization showed satisfying results for total Cr(VI) contents for most of the tested materials. However, unreliable results were obtained by applying method 3060A to anoxic soils due to the degradation of organic material and/or reactions with Fe2+-bearing mineral phases. In addition, in certain samples discrepant spike recoveries have to be also attributed to sample heterogeneity. Separation of possible extracted Cr(III) by applying cation-exchange cartridges prior to solution analysis further shows that under the hot alkaline extraction conditions only Cr(VI) is present in solution in measurable amounts, whereas Cr(III) gets precipitated as amorphous Cr(OH)3(am). It is concluded that prior to routine application of method 3060A to a new material type, spiking tests are recommended for the identification of matrix effects. In addition, the mass of extracted solid material should to be well adjusted to the heterogeneity of the Cr(VI) distribution in the material in question.
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Academic and industrial research in the late 90s have brought about an exponential explosion of DNA sequence data. Automated expert systems are being created to help biologists to extract patterns, trends and links from this ever-deepening ocean of information. Two such systems aimed on retrieving and subsequently utilizing phylogenetically relevant information have been developed in this dissertation, the major objective of which was to automate the often difficult and confusing phylogenetic reconstruction process. ^ Popular phylogenetic reconstruction methods, such as distance-based methods, attempt to find an optimal tree topology (that reflects the relationships among related sequences and their evolutionary history) by searching through the topology space. Various compromises between the fast (but incomplete) and exhaustive (but computationally prohibitive) search heuristics have been suggested. An intelligent compromise algorithm that relies on a flexible “beam” search principle from the Artificial Intelligence domain and uses the pre-computed local topology reliability information to adjust the beam search space continuously is described in the second chapter of this dissertation. ^ However, sometimes even a (virtually) complete distance-based method is inferior to the significantly more elaborate (and computationally expensive) maximum likelihood (ML) method. In fact, depending on the nature of the sequence data in question either method might prove to be superior. Therefore, it is difficult (even for an expert) to tell a priori which phylogenetic reconstruction method—distance-based, ML or maybe maximum parsimony (MP)—should be chosen for any particular data set. ^ A number of factors, often hidden, influence the performance of a method. For example, it is generally understood that for a phylogenetically “difficult” data set more sophisticated methods (e.g., ML) tend to be more effective and thus should be chosen. However, it is the interplay of many factors that one needs to consider in order to avoid choosing an inferior method (potentially a costly mistake, both in terms of computational expenses and in terms of reconstruction accuracy.) ^ Chapter III of this dissertation details a phylogenetic reconstruction expert system that selects a superior proper method automatically. It uses a classifier (a Decision Tree-inducing algorithm) to map a new data set to the proper phylogenetic reconstruction method. ^
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In this survey, we examine the operations of innovation processes within industrial districts by exploring the ways in which differentiation, specialization, and integration affect the generation, diffusion, and use of new knowledge in such districts. We begin with an analysis of the importance of the division of labor and then investigate the effects of social embeddedness on innovation. We also consider the effect of forms of organization within industrial districts at various stages of product and process life, and we examine the negative aspects of embeddedness for innovation. We conclude with a discussion of the possible consequences of new information and communications technologies on innovation in industrial districts.