280 research outputs found

    Obtenção de etanol utilizando-se de mandiocaba (Manihot esculenta Crantz).

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    A mandioca (Manihot esculenta Crantz) pode representar uma boa opção para a produção de etanol em áreas onde o cultivo da cana-de-açúcar não é viável e em períodos de entressafra. Objetivouse avaliar o rendimento em etanol do caldo fermentado obtido de raízes de mandioca doce. Foram realizados 11 ensaios em um fermentador de 1 L, seguindo um planejamento fatorial do tipo composto central (DCC), com dois níveis originais, utilizando-se o software Statistica 7.0. As condições das fermentações investigadas foram pH inicial 4,5-6,0 e temperatura 28-35ºC. Em todos os ensaios foi utilizado como mosto o caldo da mandiocaba devidamente esterilizado. Foi verificado que ao final das fermentações que se pode obter um teor alcoólico de 2,2 °GL a partir da mandiocaba. Notou-se que a produção de etanol foi maior em fermentações com baixas temperaturas, não havendo uma influência significativa do pH

    Manejo de irrigação em fruteiras tropicais.

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    As incertezas quanto a contribuição das chuvas para garantir umidade adequada no solo, tem levado a grande maioria dos fruticultores a adotarem a irrigação como tecnologia indispensável ao sistema produtivo das fruteiras. O efeito potencial da irrigação em fruteiras contribui para os dois pontos mais importantes de uma economia globalizada: o aumento da produtividade e a melhoria da qualidade da fruta. O presente trabalho procura transmitir conhecimentos básicos do sistema solo-planta-atmosfera, descrevendo os diversos métodos de obtenção dos parâmetros do solo, da planta e do clima necessários aos cálculos de manejo de irrigação. Métodos e sistemas de irrigação, necessidades hídricas e recomendações de manejo de irrigação são abordadas para fruteiras tropicais como: abacate, abacaxi, banana, citros, goiaba, mamão, manga e maracujá.bitstream/item/81294/1/Manejo-de-Irrigacao-Eugenio-Coelho-Circular-Tecnica-40-2000.pd

    The European Portuguese version of the ASAS Health Index for Patients with Spondyloarthritis: Measurement properties

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    Objective: The Assessments of SpondyloArthritis international Society Health Index (ASAS HI), estimates the impact of Spondyloarthritis (SpA) on global functioning and health. This article assesses the construct validity, reliability and responsiveness of the Portuguese version of the ASAS HI. Patients And Methods: Patients fulfilling ASAS classification criteria for axial (axSpA) or peripheral SpA (pSpA) were included. Construct validity was assessed through Spearman’s correlation analysis with other health outcomes. Discriminant validity wastested comparing the ASAS HI across disease activity and functionalstates using the Kruskal–Wallistest. Internal consistency was assessed by Cronbach’s a, and test-retest reliability by intraclass correlation coefficients (ICC). Responsiveness was evaluated by the standardized response mean (SRM) in patients with active disease who required therapy escalation. Results: Among the 91 patients included, 67% were male, mean (SD) age 47.2 (12.9) years, 63 patients with axSpA and 28 patients with pSpA. The hypothesis defined a priori to test construct validity were confirmed. The ASAS HI showed ability to discriminate between patients with different disease activity and functional states (p<0.001). Internal consistency (Cronbach’s a: 0.88) and test-retest reliability [ICC=0.76 (95%CI 0.09-0.91)] were good. Responsiveness was moderate\ud (SRM=-0.53). The smallest detectable change was 3.0. Conclusions: The Portuguese version of the ASAS HI is a comprehensible questionnaire that is valid, reliable and responsive. It can be used to assess the impact of SpA and its treatment on functioning and health, in clinical practice and for research purposes

    Bidirectional flow of action potentials in axons drives activity dynamics in neuronal cultures

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    Objective. Recent technological advances are revealing the complex physiology of the axon and challenging long-standing assumptions. Namely, while most action potential (AP) initiation occurs at the axon initial segment in central nervous system neurons, initiation in distal parts of the axon has been reported to occur in both physiological and pathological conditions. The functional role of these ectopic APs, if exists, is still not clear, nor its impact on network activity dynamics. Approach. Using an electrophysiology platform specifically designed for assessing axonal conduction we show here for the first time regular and effective bidirectional axonal conduction in hippocampal and dorsal root ganglia cultures. We investigate and characterize this bidirectional propagation both in physiological conditions and after distal axotomy. Main results. A significant fraction of APs are not coming from the canonical synapse-dendrite-soma signal flow, but instead from signals originating at the distal axon. Importantly, antidromic APs may carry information and can have a functional impact on the neuron, as they consistently depolarize the soma. Thus, plasticity or gene transduction mechanisms triggered by soma depolarization can also be affected by these antidromic APs. Conduction velocity is asymmetrical, with antidromic conduction being slower than orthodromic. Significance. Altogether these findings have important implications for the study of neuronal function in vitro, reshaping our understanding on how information flows in neuronal cultures.info:eu-repo/semantics/publishedVersio

    Manejo de irrigação através do balanço de água no solo.

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    Balanco de água no solo; Modelo simplificado de balanço de água em solo cultivados

    METHYLPHENIDATE: PROCONVULSANT EFFECT AND ACTION ON ACETYL CHOLINESTERASE ACTIVITY IN YOUNG AND ADULT MICE

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    Objective: Methylphenidate (MPH) is a derivative of piperidine, structurally related to amphetamine. It is the most widely psychostimulant used in Brazil for treating attention deficit disorder and hyperactivity. This drug was investigated in an epilepsy model induced by pilocarpine and on acetylcholinesterase (AChE) activity in young and adult mice. Methods: The control group was treated with saline. The treated groups received MPH (2.5, 5, 10 or 20 mg/kg) in single dose, followed by pilocarpine (400mg/Kg). The groups were observed for1h after treatment. Results: MPH, in all doses, was efficacious in decreasing both the latency to first seizures and the survival percentage in young and adult animals. Determination of AChE activity in the hippocampus and striatum of young and adult animals, after pilocarpine-induced status epilepticus, demonstrated that pretreatment with MPH reduced AChE activity only in the striatum. Conclusion: Our findings suggest that MPH has proconvulsant action and cholinergic neurotransmission system can play a role in this effect

    Caracterização dos produtores do núcleo rural Buriti Vermelho - DF (2009).

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