689 research outputs found

    Simulating soil carbon sequestration from long term fertilizer and manure additions under continuous wheat using the DailyDayCent model

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    Bangabandhu Fellowship on Science and ICT project, Ministry of Science and Technology, People’s Republic of Bangladesh. Open Access via Springer Compact AgreementPeer reviewedPublisher PD

    Combination Therapy of Viral Leukemia: Statolon, Radiation and Transplantation

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    Author Institution: Celluar and Radiation Biology Laboratories, Clinical Radiation Therapy Research Center, Division of Radiology, Allegheny General HospitalStudies were carried out to determine the effectiveness of treating murine viral leukemia by combining statolon therapy with irradiation and transplantation therapy. The experimental design involved inoculating Rauscher leukemia-infected mice with statolon, a potent interferon inducer, prior to lethal whole-body irradiation and following hematopoietic cell transplantation. The data show that treating the leukemic animals in this manner resulted in positive responses from all indices of leukemia development investigated. These responses included a 42% decrease in spleen weight at autopsy, a 21% increase in survival at 30 days, and significantly decreased white blood cell counts and spleen weight during the treatment period. Although the effect of the combination therapy was not permanent and further refinement of the experimental protocol is necessary, it appears to be a promising method of treating viral leukemia

    The Power of Expert Opinion in Ecological Models Using Bayesian Methods: Impact of Grazing on Birds

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    One of our greatest challenges as researchers is predicting impacts of landuse on biota and predicting the impact of livestock grazing on birds is no exception. Insufficient data and poor survey design often yield results that are not statistically significant or difficult to interpret because researchers cannot disentangle the effects of grazing from other disturbances. This has resulted in few publications on the impact of grazing on birds alone. Ecologists with extensive experience in bird ecology in grazed landscapes could inform an analysis when time and monetary constraints limit the amount of data that can be collected. Using responses from twenty well-recognised ecologists throughout Australia we capture this expert knowledge and incorporate it into a statistical model using Bayesian methods. Although relatively new to ecology, Bayesian methods allow straightforward probability statements to be made about specific models or scenarios and they allow the integration of different types of information, including scientific judgement while formally accommodating and incorporating the uncertainty in the information provided. Data on bird density was collected across three broad levels of grazing (no/low, moderate and high) typical of sub-tropical Australia. This field data was used in conjunction with expert data to produce estimates of species persistence under grazing. The addition of expert data through priors in our model strengthened results under at least one grazing level for all but one bird species examined. When experts were in agreement credible intervals were tightened substantially, whereas when experts were in disagreement results were similar to those evaluated in the absence of expert information. In fields where there is extensive expert knowledge, yet little published data, the use of expert information as priors for ecological models is a cost effective way of making more confident predictions about the effect of management on biodiversity

    Update on Mycoplasma hyopneumoniae infections in pigs : knowledge gaps for improved disease control

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    Mycoplasma hyopneumoniae (M. hyopneumoniae) is the primary pathogen of enzootic pneumonia, a chronic respiratory disease in pigs. Infections occur worldwide and cause major economic losses to the pig industry. The present paper reviews the current knowledge on M. hyopneumoniae infections, with emphasis on identification and analysis of knowledge gaps for optimizing control of the disease. Close contact between infected and susceptible pigs is the main route of M. hyopneumoniae transmission. Management and housing conditions predisposing for infection or disease are known, but further research is needed to better understand M. hyopneumoniae transmission patterns in modern pig production systems, and to assess the importance of the breeding population for downstream disease control. The organism is primarily found on the mucosal surface of the trachea, bronchi and bronchioles. Different adhesins and lipoproteins are involved in the adherence process. However, a clear picture of the virulence and pathogenicity of M. hyopneumoniae is still missing. The role of glycerol metabolism, myoinositol metabolism and the Mycoplasma Ig binding protein-Mycoplasma Ig protease system should be further investigated for their contribution to virulence. The destruction of the mucociliary apparatus, together with modulating the immune response, enhances the susceptibility of infected pigs to secondary pathogens. Clinical signs and severity of lesions depend on different factors, such as management, environmental conditions and likely also M. hyopneumoniae strain. The potential impact of strain variability on disease severity is not well defined. Diagnostics could be improved by developing tests that may detect virulent strains, by improving sampling in live animals and by designing ELI-SAs allowing discrimination between infected and vaccinated pigs. The currently available vaccines are often cost-efficient, but the ongoing research on developing new vaccines that confer protective immunity and reduce transmission should be continued, as well as optimization of protocols to eliminate M. hyopneumoniae from pig herds

    Modelling spatial and inter-annual variations of nitrous oxide emissions from UK cropland and grasslands using DailyDayCent

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    This work contributes to the Defra funded projects AC0116: ‘Improving the nitrous oxide inventory’, and AC0114: ‘Data Synthesis, Management and Modelling’. Funding for this work was provided by the UK Department for Environment, Food and Rural Affairs (Defra) AC0116 and AC0114, the Department of Agriculture, Environment and Rural Affairs for Northern Ireland, the Scottish Government and the Welsh Government. Rothamsted Research receives strategic funding from the Biotechnology and Biological Sciences Research Council. This study also contributes to the projects: N-Circle (BB/N013484/1), U-GRASS (NE/M016900/1) and GREENHOUSE (NE/K002589/1).Peer reviewedPublisher PD

    Update on Mycoplasma hyopneumoniaeinfections in pigs: Knowledge gaps for improved disease control

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    Mycoplasma hyopneumoniae(M. hyopneumoniae) is the primary pathogen of enzooticpneumonia, a chronic respiratory disease in pigs. Infections occur worldwide andcause major economic losses to the pig industry. The present paper reviews the cur-rent knowledge onM. hyopneumoniaeinfections, with emphasis on identificationand analysis of knowledge gaps for optimizing control of the disease. Close contactbetween infected and susceptible pigs is the main route ofM. hyopneumoniaetrans-mission. Management and housing conditions predisposing for infection or diseaseare known, but further research is needed to better understandM. hyopneumoniaetransmission patterns in modern pig production systems, and to assess the impor-tance of the breeding population for downstream disease control. The organism isprimarily found on the mucosal surface of the trachea, bronchi and bronchioles. Dif-ferent adhesins and lipoproteins are involved in the adherence process. However, aclear picture of the virulence and pathogenicity ofM. hyopneumoniaeis still missing.The role of glycerol metabolism, myoinositol metabolism and theMycoplasmaIgbinding protein—MycoplasmaIg protease system should be further investigated fortheir contribution to virulence. The destruction of the mucociliary apparatus,together with modulating the immune response, enhances the susceptibility ofinfected pigs to secondary pathogens. Clinical signs and severity of lesions dependon different factors, such as management, environmental conditions and likely alsoM. hyopneumoniaestrain. The potential impact of strain variability on disease sever-ity is not well defined. Diagnostics could be improved by developing tests that maydetect virulent strains, by improving sampling in live animals and by designing ELI-SAs allowing discrimination between infected and vaccinated pigs. The currentlyavailable vaccines are often cost-efficient, but the ongoing research on developingnew vaccines that confer protective immunity and reduce transmission should becontinued, as well as optimization of protocols to eliminateM. hyopneumoniaefrompig herds.info:eu-repo/semantics/acceptedVersio

    Manipulation and removal of defects in spontaneous optical patterns

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    Defects play an important role in a number of fields dealing with ordered structures. They are often described in terms of their topology, mutual interaction and their statistical characteristics. We demonstrate theoretically and experimentally the possibility of an active manipulation and removal of defects. We focus on the spontaneous formation of two-dimensional spatial structures in a nonlinear optical system, a liquid crystal light valve under single optical feedback. With increasing distance from threshold, the spontaneously formed hexagonal pattern becomes disordered and contains several defects. A scheme based on Fourier filtering allows us to remove defects and to restore spatial order. Starting without control, the controlled area is progressively expanded, such that defects are swept out of the active area.Comment: 4 pages, 4 figure
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