371 research outputs found

    Momento de colheita do sorgo forrageiro BRS-610. I. Características agronômicas.

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    O objetivo deste trabalho foi avaliar o momento de colheita do sorgo forrageiro BRS-610. Foram avaliadas as acumulações de MS, teores de MS, proporções das partes da planta, altura e stand médio. O híbrido foi plantado em 28 canteiros num delineamento inteiramente casualizado. As idades de corte foram 96, 103, 110, 117, 124, 131, 138 dias. A altura e o stand foram medidos a cada corte. As proporções de colmo, folha e panícula foram obtidas a partir de dez plantas por canteiro. Determinou-se a matéria seca (MS) da planta e suas partes a 105° C (AOAC, 1980). A produção de MS (t/ha) baseou-se na produção de MN e teor de MS da planta e suas partes. As produções de MS da planta reduziram de 10,58 para 7,26 t/ha de 89 para 138 dias, respectivamente. As percentagens de panícula não diferiram (p< 0,05) de 96 para 138 dias e o valor médio foi de 15,51%. As percentagens de colmo aumentaram com a idade e variou de 73,03 a 81,69 %. A participação das folhas reduziu com a idade e variou de 17.90 a 3,43 % aos 89 e 138 dias, respectivamente. O teor de matéria seca aumentou com a maturidade. A variação na %MS de 89 até 138 dias foi de 19,39 a 45,86% para a planta, de 15,44 a 20,44% para o colmo, de 29,23 a 79,12% para a folha e de 29,88 a 79,84% para a panícula. Os resultados desse experimento sugerem que o ponto ideal de ensilagem deve estar entre 117 e 131 dias pós-plantio, quando se tem boa produtividade e valores de MS mais próximos do desejável para uma silagem de boa qualidade

    População de plantas e taxa de rebrota de seis cruzamentos interespecíficos de "Sorghum bicolor" e "Sorghum sudanense".

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    Foram avaliados o número de plantas e a taxa de rebrota de quatro híbridos experimentais e dois híbridos comerciais de sorgo com capim Sudão. Nos primeiros cortes de ambas as épocas ocorreram diferenças significativas (p<0,05) entre os híbridos quanto ao número de plantas, sendo que no primeiro corte da época 1, o híbrido ATF 54 x CMSXS 912 foi semelhante aos híbridos BRS 800 e CMSXS 156 x CMSXS 912, sendo superior aos demais híbridos. No primeiro corte da segunda época, o híbrido ATF54 x CMSXS 912 apresentou número de plantas semelhantes aos híbridos AG2501C, BRS 800 e CMSXS 157 x CMSXS 912, porém superiores aos híbridos CMSXS 156 x CMSXS 912 e CMSXS 210 x CMSXS 912. Já na segunda época de plantio, os híbridos AG2501C, BRS 800 e ATF 54 x CMSXS 912 tiveram seu número de plantas reduzido a partir do segundo corte, enquanto os híbridos CMSXS 156 X CMSXS 912, CMSXS 157 x CMSXS 912, CMSXS 210 x CMSXS 912 mantiveram o número de plantas até o segundo corte, a partir do qual também houve redução. A média do número de plantas/ha foi significativamente (p<0,05) maior na época 1, com média de 841,66 mil plantas/ha. As taxas médias de rebrota foram inferiores a 1,00, não havendo diferença entre híbridos. Não houve diferença significativa (p<0,05) para as médias de rebrota entre híbridos, com exceção do híbrido AG2501C (testemunha) que, na rebrota 1, apresentou valor superior na época 1. O híbridos analisados apresentam uma boa quantidade de plantas por hectare e ótima taxa de rebrota

    Produção de matéria verde, matéria seca e matéria seca digestível de hibridos de "Sorghum bicolor" com "Sorghum sudanense".

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    Foram avaliadas as produções de matéria verde (MV), matéria seca (MS) e matéria seca digestível (MSDG) de seis híbridos de "Sorghum bicolor" com "Sorghum sudanense". Foram utilizados dois híbridos comerciais e quatro híbridos experimentais. Utilizou-se um delineamento experimental de blocos ao acaso, com quatro repetições de seis híbridos plantados em duas épocas diferentes e submetidos a três cortes consecutivos. As análises foram feitas utilizando-se o teste SNK (p0,05) entre os híbridos para a produção media de MV e MS, com valores variando de 13,63 a 18,37 e 1,71 a 2,28 t/ha, respectivamente. A média de produção de MV e MS da época 2 foi significativamente (p0,05) entre híbridos, com valores entre 0,96 a 1,28 t/ha. Na época 1 não houve diferença entre híbridos dentro de cada corte. A época 2 apresentou média de produção de MSDG superior à época 1. A produção de MSDG apresentou correlação de 0,99 (p<0,0001) com a produção de MS. Não houve diferença entre os híbridos para as produções totais de MSDG, com valores entre 2,87 a 3,86 t/ha

    CARDIOVASCULAR MEDICINE C reactive protein concentration and recurrence of atrial fibrillation after electrical cardioversion

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    Background: To test the hypothesis that a high C reactive protein (CRP) concentration would predict recurrence of atrial fibrillation (AF) after cardioversion in patients taking antiarrhythmic drugs. Methods: 111 patients who underwent direct current cardioversion for symptomatic AF were enrolled. Blood was drawn for CRP determination before cardioversion on the same day. All patients were taking antiarrhythmic drugs before and after electrical cardioversion. Results: After a mean follow up of 76 days, 75 patients had recurrence of AF. In univariate analysis, the median CRP concentration was significantly higher in patients with AF recurrence (3.95 mg/l v 1.81 mg/l, p = 0.002). Among the 55 patients with CRP in the upper 50th centile, 44 (80%) experienced recurrence of AF over a total follow up of 8.98 patient years, whereas among the 56 patients with CRP in the lower 50th centile, 31 (55%) experienced recurrence of AF over a total follow up of 14.3 patient years (p , 0.001). The adjusted hazard ratio comparing the upper 50th centile of CRP with the lower 50th centile of CRP was 2.0 (95% confidence interval 1.2 to 3.2, p = 0.007). Conclusions: CRP is independently associated with recurrence of AF after electrical cardioversion among patients taking antiarrhythmic drugs. These results suggest that inflammation may have a role in the pathogenesis of AF resistant to antiarrhythmic drugs

    Perovskite solar cells: a deep analysis using current–voltage and capacitance–voltage techniques

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    Perovskite solar cells exhibiting~14–15% efficiency were experimentally measured using current–voltage (I–V) and capacitance–voltage (C–V) techniques in order to extract material and device properties, and understand the action of photovoltaic (PV) operation. Deep analyses were carried out on dark- and illuminated I–V curves, and dark C–V curves. Results were compared with those of graded bandgap solar cells fabricated on inorganic n-type window layers. These analyses according to a physicist’s point of view lead to understand the perovskite solar cell as a graded bandgap solar cell built on a p-type window layer. I–V and C–V results show very similar behaviour and the principle of PV action is identical. Once the stability issues with perovskites are solved, these devices have very high potential of producing next generation solar cells reaching at least mid-20% efficiency values

    Sub-surface Oxygen and Surface Oxide Formation at Ag(111): A Density-functional Theory Investigation

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    To help provide insight into the remarkable catalytic behavior of the oxygen/silver system for heterogeneous oxidation reactions, purely sub-surface oxygen, and structures involving both on-surface and sub-surface oxygen, as well as oxide-like structures at the Ag(111) surface have been studied for a wide range of coverages and adsorption sites using density-functional theory. Adsorption on the surface in fcc sites is energetically favorable for low coverages, while for higher coverage a thin surface-oxide structure is energetically favorable. This structure has been proposed to correspond to the experimentally observed (4x4) phase. With increasing O concentrations, thicker oxide-like structures resembling compressed Ag2O(111) surfaces are energetically favored. Due to the relatively low thermal stability of these structures, and the very low sticking probability of O2 at Ag(111), their formation and observation may require the use of atomic oxygen (or ozone, O3) and low temperatures. We also investigate diffusion of O into the sub-surface region at low coverage (0.11 ML), and the effect of surface Ag vacancies in the adsorption of atomic oxygen and ozone-like species. The present studies, together with our earlier investigations of on-surface and surface-substitutional adsorption, provide a comprehensive picture of the behavior and chemical nature of the interaction of oxygen and Ag(111), as well as of the initial stages of oxide formation.Comment: 17 pages including 14 figures, Related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm

    In-reach specialist nursing teams for residential care homes : uptake of services, impact on care provision and cost-effectiveness

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    Background: A joint NHS-Local Authority initiative in England designed to provide a dedicated nursing and physiotherapy in-reach team (IRT) to four residential care homes has been evaluated.The IRT supported 131 residents and maintained 15 'virtual' beds for specialist nursing in these care homes. Methods: Data captured prospectively (July 2005 to June 2007) included: numbers of referrals; reason for referral; outcome (e.g. admission to IRT bed, short-term IRT support); length of stay in IRT; prevented hospital admissions; early hospital discharges; avoided nursing home transfers; and detection of unrecognised illnesses. An economic analysis was undertaken. Results: 733 referrals were made during the 2 years (range 0.5 to 13.0 per resident per annum)resulting in a total of 6,528 visits. Two thirds of referrals aimed at maintaining the resident's independence in the care home. According to expert panel assessment, 197 hospital admissions were averted over the period; 20 early discharges facilitated; and 28 resident transfers to a nursing home prevented. Detection of previously unrecognised illnesses accounted for a high number of visits. Investment in IRT equalled £44.38 per resident per week. Savings through reduced hospital admissions, early discharges, delayed transfers to nursing homes, and identification of previously unrecognised illnesses are conservatively estimated to produce a final reduction in care cost of £6.33 per resident per week. A sensitivity analysis indicates this figure might range from a weekly overall saving of £36.90 per resident to a 'worst case' estimate of £2.70 extra expenditure per resident per week. Evaluation early in implementation may underestimate some cost-saving activities and greater savings may emerge over a longer time period. Similarly, IRT costs may reduce over time due to the potential for refinement of team without major loss in effectiveness. Conclusion: Introduction of a specialist nursing in-reach team for residential homes is at least cost neutral and, in all probability, cost saving. Further benefits include development of new skills in the care home workforce and enhanced quality of care. Residents are enabled to stay in familiar surroundings rather than unnecessarily spending time in hospital or being transferred to a higher dependency nursing home setting
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