1,007 research outputs found

    Economic results of the integrated crop-livestock systems implementation in degraded pastures in Pium, TO, Brazil.

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    In Pium, Tocantins state, Brazil, in 2012 Embrapa developed a technology transference project in partnership with the state?s rural extension service for the consolidation of low carbon emissions agriculture. The goal was to recover the degraded grasslands of the Trigueira farm (49°1'37.44"W and 10°24'58.84"S) with low cost using a crop-livestock system

    Morphogenetic and structural characteristics of guinea grass pastures submitted to three frequencies and two defoliation severities.

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    It was evaluated the morphogenic and structural characteristics of guinea grass under rotational at three grazing intervals and two defoliation intensities. Grazing intervals corresponded to the time needed by the forage canopy to reach 90, 95 or 100% of incident light interception during regrowth and they were evaluated combined to two defoliation severities (post-grazing conditions, 25 and 50 cm of height), being allocated to experimental units according to a complete randomized design, with three replicates and 3 × 2 factorial arrangement. The experiment was conducted from July 2003 to May 2004. For evaluation of morphogenetic and structural characteristics, ten tillers per experimental unit were selected. Morphogenetic and structural characteristics were strongly influenced by seasons of the year inasmuch as leaf elongation rate increased 3.5 fold from winter to summer. In addition to year season effect, there was also an effect of defoliation frequencies on tiller population density, which was greater in the defoliation period corresponding to 90% of light interception, especially if evaluated in relation to the interval corresponding to 100% of light interception. Defoliation frequency is determinant in expression of phenotypic plasticit, acting on the control of stem elongation

    Morphogenetic and structural characteristics of guinea grass pastures submitted to three frequencies and two defoliation severities.

    Get PDF
    It was evaluated the morphogenic and structural characteristics of guinea grass under rotational at three grazing intervals and two defoliation intensities. Grazing intervals corresponded to the time needed by the forage canopy to reach 90, 95 or 100% of incident light interception during regrowth and they were evaluated combined to two defoliation severities (post-grazing conditions, 25 and 50 cm of height), being allocated to experimental units according to a complete randomized design, with three replicates and 3 × 2 factorial arrangement. The experiment was conducted from July 2003 to May 2004. For evaluation of morphogenetic and structural characteristics, ten tillers per experimental unit were selected. Morphogenetic and structural characteristics were strongly influenced by seasons of the year inasmuch as leaf elongation rate increased 3.5 fold from winter to summer. In addition to year season effect, there was also an effect of defoliation frequencies on tiller population density, which was greater in the defoliation period corresponding to 90% of light interception, especially if evaluated in relation to the interval corresponding to 100% of light interception. Defoliation frequency is determinant in expression of phenotypic plasticit, acting on the control of stem elongation

    Virtual reality and rehabilitation: why or why not? A systematic literature review

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    O processo de reabilitação, independentemente da área de saúde a que se refere, continua a ser um desafio para profissionais, pacientes e suas famílias. Na tentativa de superar as limitações das intervenções tradicionais, a tecnologia de Realidade Virtual (RV) tem sido aplicada de forma crescente à reabilitação e começa a fornecer importantes ferramentas que, contudo, geram debate e posicionamentos divergentes. Com o objetivo de investigar quais os contributos da RV aplicada ao domínio da reabilitação, nomeadamente em termos das vantagens e limitações que comporta, o presente estudo procede a uma revisão sistemática da produção científica nesta área e apresenta um modelo que permite, de modo hierarquizado, descrever e sistematizar a natureza dos estudos revistos e as principais temáticas abordadas. A revisão sistemática focou-se sobre trabalhos científicos indexados, até novembro de 2010, na base de dados ISI Web of Knowledge. Os trabalhos incluídos foram analisados por dois investigadores independentes no programa NVivo 9 e o modelo desenvolvido aplicado à recodificação do material em análise. Foram identificados 963 artigos, dos quais, aplicados os critérios de exclusão, 288 títulos e resumos foram analisados. O modelo desenvolvido indica, como categorias centrais da bibliografia: Tipo de Artigo (Empírico; Teórico); Contextualização do Projeto; Tipo de Abordagem (Tecnologia Assistiva; Realidade Aumentada; Abordagens Tradicionais; Realidade Virtual). Esta última categoria (RV) foi decomposta de forma exaustiva para documentação da sua aplicabilidade, efeitos e tendências futuras. Como vantagens da RV, surgem: a possibilidade de sua aplicação a uma diversidade de domínios, funções cognitivas, comportamentos, doenças neurológicas e incapacidades físicas; as suas características e respetivas consequências; e a possibilidade de superar limitações das intervenções tradicionais. Do lado das limitações aparecem discutidos: os efeitos secundários da RV, as causas das limitações e precauções sugeridas. Os resultados evidenciam tendências promissoras acerca da utilização da tecnologia de RV no domínio da reabilitação, com implicações para a forma como será realizada no futuro. Sugerem ainda a necessidade de dar continuidade aos trabalhos que procuram avaliar a aplicabilidade da RV na reabilitação em geral e na reabilitação (neuro) cognitiva em particular.Regardless of the health domain involved, the process of rehabilitation remains a challenge for professionals, patients and their families. In an attempt to overcome the limitations of traditional interventions, the technology of Virtual Reality (VR) has been increasingly applied to rehabilitation and begins to provide important tools which, however, generate debate and divergent positions. In order to examine VR's contributions to the field of rehabilitation in terms of its advantages and limitations, this study presents a systematic review of scientific literature in this area and provides a hierarchical model describing and systematizing the nature of the studies reviewed and their main subjects. The literature review focused on scientific papers indexed, until November 2010, in the ISI Web of Knowledge databases. Two independent researchers analyzed the included papers in NVivo 9 and the developed model was applied to the recoding of the material. A total of 963 articles were identified, of which 288 titles and abstracts were reviewed, after application of the exclusion criteria. The model indicates, as central categories in the literature: Type of Article (Empirical, Theoretical); Project Background; Type of Approach (Assistive Technology; Augmented Reality; Traditional Approaches; Virtual Reality). This last category (VR) was exhaustively decomposed so that its applicability, effects and future trends could be documented. Results suggest that VR's advantages include: its possible application to a variety of fields, cognitive functions, behaviors, neurological disorders and physical disabilities; its characteristics and respective consequences; and its potential to overcome limitations of traditional interventions. On the side of the limitations, papers address: VR's side effects, causes for the limitations, and suggested precautions. The results show promising trends in the use of VR technology in the field of rehabilitation, with implications for its future implementation. Results further indicate the need for continuing research that evaluates VR's applicability to rehabilitation in general and (neuro)cognitive rehabilitation in particular.info:eu-repo/semantics/publishedVersio

    An fMRI paradigm based on Williams inhibition test to study the neural substrates of attention and inhibitory control

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    The purpose of this study is to present an fMRI paradigm, based on the Williams inhibition test (WIT), to study attentional and inhibitory control and their neuroanatomical substrates. We present an index of the validity of the proposed paradigm and test whether the experimental task discriminates the behavioral performances of healthy participants from those of individuals with acquired brain injury. Stroop and Simon tests present similarities with WIT, but this latter is more demanding. We analyze the BOLD signal in 10 healthy participants performing the WIT. The dorsolateral prefrontal cortex, the inferior prefrontal cortex, the anterior cingulate cortex, and the posterior cingulate cortex were defined for specified region of interest analysis. We additionally compare behavioral data (hits, errors, reaction times) of the healthy participants with those of eight acquired brain injury patients. Data were analyzed with GLM-based random effects and Mann-Whitney tests. Results show the involvement of the defined regions and indicate that the WIT is sensitive to brain lesions. This WIT-based block design paradigm can be used as a research methodology for behavioral and neuroimaging studies of the attentional and inhibitory components of executive functions.info:eu-repo/semantics/publishedVersio
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