971 resultados para Agricultural and Biological Sciences(all)
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Brazilian scientific output exhibited a 4-fold increase in the last two decades because of the stability of the investment in research and development activities and of changes in the policies of the main funding agencies. Most of this production is concentrated in public universities and research institutes located in the richest part of the country. Among all areas of knowledge, the most productive are Health and Biological Sciences. During the 1998-2002 period these areas presented heterogeneous growth ranging from 4.5% (Pharmacology) to 191% (Psychiatry), with a median growth rate of 47.2%. In order to identify and rank the 20 most prolific institutions in these areas, searches were made in three databases (DataCAPES, ISI and MEDLINE) which permitted the identification of 109,507 original articles produced by the 592 Graduate Programs in Health and Biological Sciences offered by 118 public universities and research institutes. The 20 most productive centers, ranked according to the total number of ISI-indexed articles published during the 1998-2003 period, produced 78.7% of the papers in these areas and are strongly concentrated in the Southern part of the country, mainly in São Paulo State.
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Selostus: Maatalous- ja elintarviketieteiden www-pohjaiset viitetietokannat ja aihehakemistot - suomalaisen tiedonetsijän näkökulma
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Clubroot disease and the causal microbe Plasmodiophora brassicae offer abundant challenges to agriculturists and biological scientists. This microbe is well fitted for the environments which it inhabits. Plasmodiophora brassicae exists in soil as microscopic well protected resting spores and then grows actively and reproduces while shielded inside the roots of host plants. The pathogen is active outside the host for only short periods. Consequently, scientific studies are made challenging by the biological context of the host and pathogen and the technology required to investigate and understand that relationship. Controlling clubroot disease is a challenge for farmers, crop consultants and plant pathology practitioners because of the limited options which are available. Full symptom expression happens solely in members of the Brassicaceae family. Currently, only a few genes expressing strong resistance to P. brassicae are known and readily available. Agrochemical control is similarly limited by difficulties in molecule formulation which combines efficacy with environmental acceptability. Manipulation of husbandry encouraging improvements in soil structure, texture, nutrient composition and moisture content can reduce populations of P. brassicae. Integrating such strategies with rotation and crop management will reduce but not eliminate this disease. There are indications that forms of biological competition may be mobilised as additions to integrated control strategies. The aim of this review is to chart key themes in the development of scientific biological understanding of this host-pathogen relationship by offering signposts to grapple with clubroot disease which devastates crops and their profitability. Particular attention is given to the link between soil and nutrient chemistry and activity of this microbe.
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Funding: This work was supported by funding awards to Dr Isabel Crane from the National Eye Research Centre, Bristol, UK (Grant ref. SCIAD 058); and NHS Grampian Endowment Trust (Grant ref. 10/16). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
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At head of title: U.S. Atomic Energy Commission.
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Acknowledgments The authors wish to thank the crews, fishermen and scientists who conducted the various surveys from which data were obtained, and Mark Belchier and Simeon Hill for their contributions. This work was supported by the Government of South Georgia and South Sandwich Islands. Additional logistical support provided by The South Atlantic Environmental Research Institute with thanks to Paul Brickle. Thanks to Stephen Smith of Fisheries and Oceans Canada (DFO) for help in constructing bootstrap confidence limits. Paul Fernandes receives funding from the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland), and their support is gratefully acknowledged. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions. We also wish to thank two anonymous referees for their helpful suggestions on earlier versions of this manuscript.
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Animal pain is defined by a series of expectations or criteria, one of which is that there should be a physiological stress response associated with noxious stimuli. While crustacean stress responses have been demonstrated they are typically preceded by escape behaviour and thus the physiological change might be attributed to the behaviour rather than a pain experience. We found higher levels of stress as measured by lactate in shore crabs exposed to brief electric shock than non-shocked controls. However, shocked crabs showed more vigorous behaviour than controls. We then matched crabs with the same level of behaviour and still found that shocked crabs had stronger stress response compared with controls. The finding of the stress response, coupled with previous findings of long-Term motivational change and avoidance learning, fulfils the criteria expected of a pain experience.
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Insights into the potential for pain may be obtained from examination of behavioural responses to noxious stimuli. In particular, prolonged responses coupled with long-term motivational change and avoidance learning cannot be explained by nociceptive reflex but are consistent with the idea of pain. Here, we placed shore crabs alternately in two halves of a test area divided by an opaque partition. Each area had a dark shelter and in one repeated small electric shocks were delivered in an experimental but not in a control group. Crabs showed no specific avoidance of the shock shelter either during these trials or in a subsequent test in which both were offered simultaneously; however they often emerged from the shock shelter during a trial and thus avoided further shock. More crabs emerged in later trials and took less time to emerge than in early trials. Thus, despite the lack of discrimination learning between the two shelters they used other tactics to markedly reduce the amount of shock received. We note that a previous experiment using simultaneous presentation of two shelters demonstrated rapid discrimination and avoidance learning but the paradigm of sequential presentation appears to prevent this. Nevertheless, the data show clearly that the shock is aversive and tactics, other than discrimination learning, are used to avoid it. Thus, the behaviour is only partially consistent with the idea of pain.
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Field trials and laboratory bioassays were undertaken to compare the performance and efficacy (mortality of diamondback moth larvae) of insecticides applied to cabbages with three high volume hydraulic knapsack sprayers (NS-16, PB-20 and Selecta 12V) and a controlled droplet application (CDA) sprayer. In field experiments, the high volume knapsack sprayers (application rate 500-600 L ha(-1)) provided better spray coverage on the upper and lower surfaces of inner leaves, the upper surfaces of middle and outer leaves, and greater biological efficacy than the CDA sprayer (application rate 20similar to40 L ha(-1)). The PB-20 provided better spray coverage on the upper surface of middle leaves and both surfaces of outer leaves when compared with the Selecta 12V. However, its biological efficacy in the field was not significantly different from that of the other high volume sprayers. Increasing the application rate from 20 to 40 L ha(-1) for the CDA sprayer significantly increased droplet density but had no impact on test insect mortality. Laboratory evaluations of biological efficacy yielded higher estimates than field evaluations and there was no significant difference between the performance of the PB-20 and the CDA sprayer. Significant positive relationships were detected between insect mortality and droplet density deposited for both the PB-20 and the CDA sprayers.
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En Argentina, desde comienzos del presente siglo, las políticas científicas y tecnológicas explícitas evidencian un claro interés en la producción de conocimientos orientados a la resolución de problemas sociales, productivos y medioambientales de carácter local. Desde la bibliometría se vienen realizando estudios sobre la producción científica de los países, existiendo varios antecedentes que enfocan la atención en la producción científica argentina. Sin embargo, son incipientes y escasos los trabajos sobre la producción científica enfocada a temas locales. Los objetivos de esta investigación son analizar y describir la relación entre lo local y lo global en la producción científica argentina con visibilidad en Scopus en el período 2008-2012, y comparar indicadores de publicación, colaboración y liderazgo desde las dimensiones nacionales e internacionales de las prácticas de comunicación científica. Los resultados muestran ;que una cuarta parte de la producción está orientada a temas locales, con destacada presencia de contribuciones en Ciencias sociales, Economía y Administración, Ciencias agrícolas y biológicas, Ciencias de la tierra y relacionadas con el ambiente. Un alto porcentaje de esta producción se publica en revistas extra-regionales. Hay un mayor predominio de investigación en colaboración nacional y sin colaboración en los temas locales. Sin embargo casi un tercio de la producción se realizó en colaboración internacional, con diferencias porcentuales según las disciplinas. Por último, destaca el alto porcentaje de producción liderada por investigadores de instituciones argentinas en todas las disciplinas, tanto en los temas locales como globales
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En Argentina, desde comienzos del presente siglo, las políticas científicas y tecnológicas explícitas evidencian un claro interés en la producción de conocimientos orientados a la resolución de problemas sociales, productivos y medioambientales de carácter local. Desde la bibliometría se vienen realizando estudios sobre la producción científica de los países, existiendo varios antecedentes que enfocan la atención en la producción científica argentina. Sin embargo, son incipientes y escasos los trabajos sobre la producción científica enfocada a temas locales. Los objetivos de esta investigación son analizar y describir la relación entre lo local y lo global en la producción científica argentina con visibilidad en Scopus en el período 2008-2012, y comparar indicadores de publicación, colaboración y liderazgo desde las dimensiones nacionales e internacionales de las prácticas de comunicación científica. Los resultados muestran ;que una cuarta parte de la producción está orientada a temas locales, con destacada presencia de contribuciones en Ciencias sociales, Economía y Administración, Ciencias agrícolas y biológicas, Ciencias de la tierra y relacionadas con el ambiente. Un alto porcentaje de esta producción se publica en revistas extra-regionales. Hay un mayor predominio de investigación en colaboración nacional y sin colaboración en los temas locales. Sin embargo casi un tercio de la producción se realizó en colaboración internacional, con diferencias porcentuales según las disciplinas. Por último, destaca el alto porcentaje de producción liderada por investigadores de instituciones argentinas en todas las disciplinas, tanto en los temas locales como globales
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En Argentina, desde comienzos del presente siglo, las políticas científicas y tecnológicas explícitas evidencian un claro interés en la producción de conocimientos orientados a la resolución de problemas sociales, productivos y medioambientales de carácter local. Desde la bibliometría se vienen realizando estudios sobre la producción científica de los países, existiendo varios antecedentes que enfocan la atención en la producción científica argentina. Sin embargo, son incipientes y escasos los trabajos sobre la producción científica enfocada a temas locales. Los objetivos de esta investigación son analizar y describir la relación entre lo local y lo global en la producción científica argentina con visibilidad en Scopus en el período 2008-2012, y comparar indicadores de publicación, colaboración y liderazgo desde las dimensiones nacionales e internacionales de las prácticas de comunicación científica. Los resultados muestran ;que una cuarta parte de la producción está orientada a temas locales, con destacada presencia de contribuciones en Ciencias sociales, Economía y Administración, Ciencias agrícolas y biológicas, Ciencias de la tierra y relacionadas con el ambiente. Un alto porcentaje de esta producción se publica en revistas extra-regionales. Hay un mayor predominio de investigación en colaboración nacional y sin colaboración en los temas locales. Sin embargo casi un tercio de la producción se realizó en colaboración internacional, con diferencias porcentuales según las disciplinas. Por último, destaca el alto porcentaje de producción liderada por investigadores de instituciones argentinas en todas las disciplinas, tanto en los temas locales como globales
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Millets are major food and feed sources in the developing world especially in the semi-arid tropical regions of Africa and Asia. The most widely cultivated millets are pearl millet [Pennisetum glaucum (L.) R. Br.], finger millet [Eleusine coracana (L.) Gaertn], foxtail millet [Setaria italica (L.) P. Beauvois], Japanese barnyard millet [Echinochloa esculneta (A. Braun) H. Scholz], Indian Barnyard millet [Echinochloa frumetacea Link], kodo millet [Paspalum scrobiculatum L.], little millet [Panicum sumatrense Roth.ex.Roem. & Schult.], proso millet [Panicum miliaceum L.], tef [Eragrostis tef (Zucc.) Trotter] and fonio or acha [Digitaria exilis (Kippist) Stapf and D. iburua Stapf]. Millets are resilient to extreme environmental conditions especially to inadequate moisture and are rich in nutrients. Millets are also considered to be a healthy food, mainly due to the lack of gluten (a substance that causes coeliac disease) in their grain. Despite these agronomic, nutritional and health-related benefits, millets produce very low yield compared to major cereals such as wheat and rice. This extremely low productivity is related to the challenging environment in which they are extensively cultivated and to the little research investment in these crops. Recently, several national and international initiatives have begun to support the improvement of diverse millet types.
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With the widespread availability of high-throughput sequencing technologies, sequencing projects have become pervasive in the molecular life sciences. The huge bulk of data generated daily must be analyzed further by biologists with skills in bioinformatics and by "embedded bioinformaticians," i.e., bioinformaticians integrated in wet lab research groups. Thus, students interested in molecular life sciences must be trained in the main steps of genomics: sequencing, assembly, annotation and analysis. To reach that goal, a practical course has been set up for master students at the University of Lausanne: the "Sequence a genome" class. At the beginning of the academic year, a few bacterial species whose genome is unknown are provided to the students, who sequence and assemble the genome(s) and perform manual annotation. Here, we report the progress of the first class from September 2010 to June 2011 and the results obtained by seven master students who specifically assembled and annotated the genome of Estrella lausannensis, an obligate intracellular bacterium related to Chlamydia. The draft genome of Estrella is composed of 29 scaffolds encompassing 2,819,825 bp that encode for 2233 putative proteins. Estrella also possesses a 9136 bp plasmid that encodes for 14 genes, among which we found an integrase and a toxin/antitoxin module. Like all other members of the Chlamydiales order, Estrella possesses a highly conserved type III secretion system, considered as a key virulence factor. The annotation of the Estrella genome also allowed the characterization of the metabolic abilities of this strictly intracellular bacterium. Altogether, the students provided the scientific community with the Estrella genome sequence and a preliminary understanding of the biology of this recently-discovered bacterial genus, while learning to use cutting-edge technologies for sequencing and to perform bioinformatics analyses.