853 resultados para 1094


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Ten Canadian expert rowing coaches and 10 Canadian elite rowers were interviewed regarding their perceptions of effective coaching behaviors. The questions of the interview guide focused on coaches' behaviors in training, competition, and organization settings. Qualitative data analyses revealed seven behaviors elicited by coaches and athletes. Effective coaching behaviors perceived as important by both athletes and coaches were; 1) plan proactively, 2)create a positive training environment, 3)facilitate goal setting, 4)build athletes' confidence, 5) teach skills effectively, 6)recognize individual differences, and 7)establish a positive rapport with each athlete.

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En este artículo nuestro objetivo fue indagar la percepción de estudiantes universitarios con discapacidad visual (ECDV) acerca del desarrollo de sus competencias digitales. Participaron en el estudio los diez ECDV inscritos en programas de licenciatura en el ciclo 2014-02. Evaluamos el avance que perciben los estudiantes en competencias digitales relacionadas con el aprendizaje social y colaborativo, la búsqueda y tratamiento de la información, el desarrollo de relaciones interpersonales en el contexto universitario, y el uso de herramientas virtuales y de comunicación social de la universidad. Los resultados sugieren que, a excepción de aquellas referentes a las relaciones interpersonales, los ECDV perciben poco adelanto en sus competencias digitales. Con una prueba Anova de medidas repetidas, determinamos que la percepción de los ECDV sobre las competencias digitales concernientes a las relaciones interpersonales es significativamente mayor que la que reportan en las otras competencias. Concluimos que los ECDV no perciben una mejora en sus competencias digitales, en particular las de aprendizaje social y colaborativo, así como el uso de herramientas digitales.

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On-site detection of inoculum of polycyclic plant pathogens could potentially contribute to management of disease outbreaks. A 6-min, in-field competitive immunochromatographic lateral flow device (CLFD) assay was developed for detection of Alternaria brassicae (the cause of dark leaf spot in brassica crops) in air sampled above the crop canopy. Visual recording of the test result by eye provides a detection threshold of approximately 50 dark leaf spot conidia. Assessment using a portable reader improved test sensitivity. In combination with a weather-driven infection model, CLFD assays were evaluated as part of an in-field risk assessment to identify periods when brassica crops were at risk from A. brassicae infection. The weather-driven model overpredicted A. brassicae infection. An automated 7-day multivial cyclone air sampler combined with a daily in-field CLFD assay detected A. brassicae conidia air samples from above the crops. Integration of information from an in-field detection system (CLFD) with weather-driven mathematical models predicting pathogen infection have the potential for use within disease management systems.

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El objetivo del documento es identificar dos posibles canales que expliquen por qué el programa OLPC en el Perú no generó efectos significativos en el rendimiento de los niños. Para ello se estimará el efecto de la introducción de tecnología (en este caso, laptops) sobre dos potenciales canales: el método de enseñanza del profesor y el tiempo destinado a actividades dentro del hogar. En primer lugar se espera que la entrega de laptops haya reducido la probabilidad que el alumno reciba un método centrado en el alumno donde se promueven las actividades cooperativas. A pesar de que este tipo de método genera un impacto positivo en el rendimiento del alumno. En segundo lugar, se espera que la entrega de laptops haya reducido el tiempo destinado a quehaceres domésticos, cuando estos inciden negativamente el rendimiento de los alumnos. A través de una estimación de mínimos cuadrados ordinarios en dos etapas y bajo una regresión simple se encuentra que la entrega exógena de laptops reduce la probabilidad del profesor de implementar un método centrado en el alumno con actividades cooperativas entre 10 y 8 puntos porcentuales para los cursos de lenguaje y matemáticas respectivamente. Para lenguaje; ello incide en el rendimiento, ya que este método genera un efecto positivo y significativo en el rendimiento de 0.025 desviaciones estándar. Mientras que, para matemáticas, el método no tiene efecto alguno en el rendimiento académico.

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Puccinia psidii (Myrtle rust) is an emerging pathogen that has a wide host range in the Myrtaceae family; it continues to show an increase in geographic range and is considered to be a significant threat to Myrtaceae plants worldwide. In this study, we describe the development and validation of three novel real-time polymerase reaction (qPCR) assays using ribosomal DNA and β-tubulin gene sequences to detect P. psidii. All qPCR assays were able to detect P. psidii DNA extracted from urediniospores and from infected plants, including asymptomatic leaf tissues. Depending on the gene target, qPCR was able to detect down to 0.011 pg of P. psidii DNA. The most optimum qPCR assay was shown to be highly specific, repeatable, and reproducible following testing using different qPCR reagents and real-time PCR platforms in different laboratories. In addition, a duplex qPCR assay was developed to allow coamplification of the cytochrome oxidase gene from host plants for use as an internal PCR control. The most optimum qPCR assay proved to be faster and more sensitive than the previously published nested PCR assay and will be particularly useful for high-throughput testing and to detect P. psidii at the early stages of infection, before the development of sporulating rust pustules.

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Glutamine synthetase (GS) is a vital enzyme for the assimilation of ammonia into amino acids in higher plants. In legumes, GS plays a crucial role in the assimilation of the ammonium released by nitrogen-fixing bacteria in root nodules, constituting an important metabolic knob controlling the nitrogen (N) assimilatory pathways. To identify new regulators of nodule metabolism, we profiled the transcriptome of Medicago truncatula nodules impaired in N assimilation by specifically inhibiting GS activity using phosphinothricin (PPT). Global transcript expression of nodules collected before and after PPT addition (4, 8, and 24 h) was assessed using Affymetrix M. truncatula GeneChip arrays. Hundreds of genes were regulated at the three time points, illustrating the dramatic alterations in cell metabolism that are imposed on the nodules upon GS inhibition. The data indicate that GS inhibition triggers a fast plant defense response, induces premature nodule senescence, and promotes loss of root nodule identity. Consecutive metabolic changes were identified at the three time points analyzed. The results point to a fast repression of asparagine synthesis and of the glycolytic pathway and to the synthesis of glutamate via reactions alternative to the GS/GOGAT cycle. Several genes potentially involved in the molecular surveillance for internal organic N availability are identified and a number of transporters potentially important for nodule functioning are pinpointed. The data provided by this study contributes to the mapping of regulatory and metabolic networks involved in root nodule functioning and highlight candidate modulators for functional analysis.

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There is no information on the effect of sulfuryl fluoride (SF) on durum wheat technological properties and products made from fumigated durum wheat. Durum wheat and semolina were exposed to a range of SF applications under conditions that might be typically encountered in bulk storage facilities used in many countries. SF greatly reduced the germination percentage of fumigated durum wheat with increasing impact under higher SF concentration, grain moisture content, and fumigation temperature. SF greatly reduced seed germination percentage impacting more the higher the SF concentration. SF had little to no effects on grain test weight, 1000 grain weight, hardness, protein content, semolina ash content and mixograph properties. At the highest SF concentration (31.25 mg/L for 48 h) there was a tendency for pasta cooking loss to be increased but still acceptable while other pasta properties were largely unaffected. Fumigation with SF did not have any impact on the baking properties of a wholemeal durum flour-commercial flour mix. Therefore, SF is not recommended if the grains are to be used as seeds for agricultural production but for the production of semolina, pasta and bread, SF used under typical fumigation conditions has little to no impact on technological properties of durum wheat.

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This paper presents a case-based heuristic selection approach for automated university course and exam timetabling. The method described in this paper is motivated by the goal of developing timetabling systems that are fundamentally more general than the current state of the art. Heuristics that worked well in previous similar situations are memorized in a case base and are retrieved for solving the problem in hand. Knowledge discovery techniques are employed in two distinct scenarios. Firstly, we model the problem and the problem solving situations along with specific heuristics for those problems. Secondly, we refine the case base and discard cases which prove to be non-useful in solving new problems. Experimental results are presented and analyzed. It is shown that case based reasoning can act effectively as an intelligent approach to learn which heuristics work well for particular timetabling situations. We conclude by outlining and discussing potential research issues in this critical area of knowledge discovery for different difficult timetabling problems.

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"Ciência e cultura mas que mistura” tem como principal objetivo dar a conhecer a TCA, promover a sua utilização como uma ferramenta acessível e desta forma contribuir para melhorar os hábitos alimentares dos cidadãos. A TCA é um documento de referência nacional para a composição dos alimentos consumidos em Portugal, que reúne informação sobre o teor de 42 componentes/nutrientes (Energia, Macroconstituintes, Ácidos Gordos, Colesterol, Vitaminas e Minerais). A versão atual da TCA inclui 1094 alimentos (crus, cozinhados e processados). É uma iniciativa do Instituto Ricardo Jorge, através do seu Departamento de Alimentação e Nutrição, em colaboração com a Associação dos Armadores de Pesca Local e Artesanal do Centro Sul e a Docapesca. Nesta primeira edição da iniciativa será apresentado o grupo do pescado, alimento-chave no padrão de alimentação mediterrânico.

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"Ciência e cultura mas que mistura” tem como principal objetivo dar a conhecer a TCA, promover a sua utilização como uma ferramenta acessível e desta forma contribuir para melhorar os hábitos alimentares dos cidadãos. A TCA é um documento de referência nacional para a composição dos alimentos consumidos em Portugal, que reúne informação sobre o teor de 42 componentes/nutrientes (Energia, Macroconstituintes, Ácidos Gordos, Colesterol, Vitaminas e Minerais). A versão atual da TCA inclui 1094 alimentos (crus, cozinhados e processados). É uma iniciativa do Instituto Ricardo Jorge, através do seu Departamento de Alimentação e Nutrição, em colaboração com a Associação dos Armadores de Pesca Local e Artesanal do Centro Sul e a Docapesca. Nesta primeira edição da iniciativa será apresentado o grupo do pescado, alimento-chave no padrão de alimentação mediterrânico.

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There is considerable interest in the use of genetic algorithms to solve problems arising in the areas of scheduling and timetabling. However, the classical genetic algorithm paradigm is not well equipped to handle the conflict between objectives and constraints that typically occurs in such problems. In order to overcome this, successful implementations frequently make use of problem specific knowledge. This paper is concerned with the development of a GA for a nurse rostering problem at a major UK hospital. The structure of the constraints is used as the basis for a co-evolutionary strategy using co-operating sub-populations. Problem specific knowledge is also used to define a system of incentives and disincentives, and a complementary mutation operator. Empirical results based on 52 weeks of live data show how these features are able to improve an unsuccessful canonical GA to the point where it is able to provide a practical solution to the problem.

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Incidence of dry flower disease of macadamia (Macadamia integrifolia), expressed as blight of the flowers, necrosis and dieback of the rachis, is increasing in Australia. In the 2012/13 production season, incidence of dry flower disease resulted in 10% to 30% yield loss in the affected orchards. Etiology of the disease has not been established. This study was established to characterise the disease and identify the causal pathogen. A survey of the major macadamia producing regions in Australia revealed dry flower disease symptoms, regardless of cultivar or location at all stages of raceme development. Based on colony and conidial morphology, the majority (41%) of fungal isolates obtained from tissue samples were identified as Pestalotiopsis and Neopestalotiopsis spp. The phylogeny of the combined partial sequence of the internal transcribed spacer, beta-tubulin and translation elongation factor 1-alpha gene loci, segregated the isolates into two well supported clades, independent of location or part of the inflorescence affected. Further morphological examination supported the establishment of two new species, which are formally described as Neopestalotiopsis macadamiae sp. nov. and Pestalotiopsis macadamiae sp. nov. Using spore suspensions of isolates of both species, Koch?s postulates were fulfilled on three macadamia cultivars at all stages of raceme development. To our knowledge, this is the first report of species of Neopestalotiopsis and Pestalotiopsis as causal agents of inflorescence disease in macadamia.