Ocorrência e sobrevivência de Botryodiplodia theobromae Papouillard em sementes de algodoeiro (Gossypium hirsutum L.) produzidas no estado de Minas Gerais.

No presente trabalho, avaliou-se a ocorrência de B. theobromae (Papouillard 1892) em sementes de algodoeiro das regiões do Triângulo e Norte do Estado de Minas Gerais, safra 90/91, utilizando-se sementes com e sem linter. O fungo foi detectado em 100% das amostras de sementes provenientes da região do Triângulo, independentemente da presença de linter. Na região Norte, foi detectado em 90,2 e 82% das sementes analisadas com e sem linter, respectivamente. Os níveis de ocorrência nas amostras estiveram, em geral, abaixo de 25%, que é a proposta para o padrão de tolerância do fungo na classe de sementes certificadas/ fiscalizadas no Brasil e menores na região Norte. A maioria das amostras apresentou crescimento médio de B.theobromae por semente, cobrindo mais de 50% de sua superfície visível, estimado através da atribuição de notas. A ocorrência de B. theobromae em sementes armazenadas durante 11 meses, sofreu declinio acentuado a partir do quarto mês e atingiu níveis próximos a zero a partir do oitavo mês, quando as sementes foram mantidas em ambiente de laboratório. A ocorrência do patógeno foi preservada ao longo deste período, quando as sementes foram mantidas em câmara fria e seca. A avaliação do percentual de germinação das sementes realizada em três épocas. durante o período de armazenamento, mostrou aumento aos 6 e 11 meses. sendo este efeito maior em ambiente de laboratório

Modelo experimental para pesquisa e desenvolvimento de aditivos alternativos para frangos de corte.

bitstream/item/85481/1/DCOT-315.pd

Cultivares de milho para silagem: recomendações para as Regiões Sul, Sudeste e Brasil-Central.

bitstream/item/44224/1/CT-103.pd

Caracterização de acessos silvestres de maracujazeiro com base em descritores morfoagronômicos.

Existem espécies silvestres de maracujazeiros que possuem potencial agronômico para a utilização no melhoramento genético e no desenvolvimento de variedades e híbridos, porém a escassez de informações morfoagronômicas dessas espécies silvestres indica a necessidade de estudos básicos relacionados à caracterização e à avaliação do germoplasma. Este trabalho teve como objetivo caracterizar acessos silvestres de maracujazeiro, com base em descritores qualitativos e quantitativos

Recurrence in intracranial atherosclerotic disease: a stenosis-based analysis

BACKGROUND: Intracranial atherosclerotic disease is a common cause of stroke; its incidence and prevalence vary widely by ethnicity. The aim of our study was to analyze the recurrence rate of cerebrovascular events in patients with symptomatic and asymptomatic intracranial stenosis (IS). METHODS: We conducted a historical cohort study including all patients admitted in our hospital for stroke or transient ischemic attack (TIA) during 2011 and 2012 with information on intracranial circulation (ultrasonography and/or computed tomography angiography). We identified patients with symptomatic and asymptomatic IS and studied the recurrence of cerebrovascular events (TIA or ischemic stroke within the territory of the stenosis) for a minimum follow-up period of 6 months after the diagnosis of IS. For the recurrence rate estimation, patients with other potentially embolic diseases (in cervical arteries or heart) were excluded. We calculated the rate of recurrence of cerebrovascular events and performed Kaplan-Meier survival curves for symptomatic and asymptomatic IS. RESULTS: We investigated 1302 patients, mean age was 72.41 years (standard deviation 12.75). We identified 218 IS in 158 patients, 77 were symptomatic and 141 were asymptomatic. The recurrence rate of cerebrovascular events was 12.32 per 100 patient-years, with a mean time to recurrence of 1.73 months for symptomatic intracranial stenosis (SIS) and .88 per 100 patient-years for asymptomatic IS (P < .001). CONCLUSIONS: These results indicate a high risk of early recurrence of stroke in the territory of a SIS, highlighting the importance of its early diagnosis and aggressive treatment.info:eu-repo/semantics/publishedVersio

Response of a catalytic reaction to periodic variation of the CO pressure: Increased CO_2 production and dynamic phase transition

We present a kinetic Monte Carlo study of the dynamical response of a Ziff-Gulari-Barshad model for CO oxidation with CO desorption to periodic variation of the CO presure. We use a square-wave periodic pressure variation with parameters that can be tuned to enhance the catalytic activity. We produce evidence that, below a critical value of the desorption rate, the driven system undergoes a dynamic phase transition between a CO_2 productive phase and a nonproductive one at a critical value of the period of the pressure oscillation. At the dynamic phase transition the period-averged CO_2 production rate is significantly increased and can be used as a dynamic order parameter. We perform a finite-size scaling analysis that indicates the existence of power-law singularities for the order parameter and its fluctuations, yielding estimated critical exponent ratios $\beta/\nu \approx 0.12$ and $\gamma/\nu \approx 1.77$. These exponent ratios, together with theoretical symmetry arguments and numerical data for the fourth-order cumulant associated with the transition, give reasonable support for the hypothesis that the observed nonequilibrium dynamic phase transition is in the same universality class as the two-dimensional equilibrium Ising model.Comment: 18 pages, 10 figures, accepted in Physical Review

Influence of the Location of the Internal Temperature Control Loop on the Performance of the Dual Temperature Control for Feed Temperature Disturbance

A control strategy with distributed corrective action for distillation has been proposed and consists of a conventional dual temperature control combined with an additional column tray. In this work, we evaluated the influence of the location of this internal loop as part of the new proposal, compared to a conventional system. Tests were carried out in a 13-column tray distillation equipment and feed temperature was disturbed. Two different column trays from the stripping section were used (11 and 12) for internal decentralized temperature control, each one separately, plus the dual control of top and bottom temperatures. The results demonstrated that this proposed control approach with distributed corrective action is faster than the conventional one, regardless of the column tray in use. It was also determined that the internal loop close to the feed (disturbance) is more interesting as a way to minimize transients