5,298 research outputs found
Efeito da fertilização precoce e roçada sobre o desenvolvimento e antecipação do ciclo de pastejo hibernal de pastagens consorciadas de hemartria e Azevém BRS Ponteio.
O objetivo do trabalho foi avaliar o desenvolvimento da pastagem consorciada de hemarthria e azevém BRS Ponteio (presente no banco de sementes do solo), submetida a dois fatores: adubação e roçada.Fernando Flores Cardoso, editor técnico
Biologia do bicho do cesto Oiketicus kirbyi (Lands.-Guilding, 1827) (Lepidoptera, Psychidae) em folhas de Eucalyptus spp
The bagworm Oiketicus kirbyi (Lands.-Guilding), an extremely polyphagous insect, is a pest of several crops of economic importance mainly in the southern region on Brazil. It occurs in eucalipt plantations although no outbreaks have been registered until today. This paper deals with the biology of 0. kirbyi on Eucalyptus spp. leaves. The insect was reared in laboratory conditions (temperature of 25±3°C, relative humidity of 70±10%, and photophase of 13 hours) and the following mean values were obtained: egg period of 43.1 days; larval period of 140 days (males) and 151 days (females); pupal period of 38.2 days (males); adult longevity of 3.0 days (males) and 3.9 days (females), and oviposition period of 2.1 days. Other data obtained were: dimensions of egg, pupa, adult and head capsules; number of larval instars; mating period and estimation of leaf damage.O bicho do cesto, Oiketicus kirbyi (Lands.-Guilding, 1827), inseto extremamente polÃfago, é praga de várias culturas de importância econômica, principalmente na região sul do Brasil. Sua ocorrência em áreas reflorestadas com eucalipto é freqüente, embora não tenha causado, ainda, danos econômicos de monta. Este trabalho trata da biologia deste inseto em folhas de Eucalyptus spp., com a finalidade de trazer subsÃdios para o caso de eventuais surtos de O. kirbyi em florestas implantadas. O bicho do cesto foi criado em laboratório em temperatura de 25±3°C, umidade relativa de 70± 10% e fotofase de 13 h. Os seguintes valores médios foram obtidos: perÃodo embrionário de 43,1 dias, perÃodo larval de 140 dias (machos) e 151 dias (fêmeas), perÃodo pupal de 38,2 dias (machos), longevidade dos adultos de 3,0 dias (machos) e 3,9 dias (fêmeas) e perÃodo de oviposição 2,1 dias. Foram determinadas, também, as dimensões de ovos, pupas, adultos e das cápsulas cefálicas, o número de Ãnstares larvais, perÃodo de cópula, além da estimativa do dano foliar
Economic analysis and revenue optimization in management regimes of Pinus taeda.
Este trabalho teve por objetivo selecionar, por meio de técnicas da pesquisa operacional, regimes de manejo de Pinus taeda L. que maximizem a receita com a madeira produzida, considerando diferentes taxas de atratividade. Foi utilizado o software OpTimber?LP® para a otimização florestal, o qual realiza as simulações por meio do software SisPinus®. Os regimes foram compostos por diferentes combinações de sÃtios florestais, densidades de plantio, regimes de desbaste e idades para corte raso, totalizando 17.760 regimes por sÃtio. A produção de madeira foi quantificada e valorada mediante classes de sortimento. Custos de plantio, desbaste e colheita foram considerados. O Valor Presente LÃquido Anualizado (VPLA) e a Taxa Interna de Retorno (TIR) de cada regime de manejo foram calculados. Como resultado, a densidade de 1.600 plantas por ha otimizou o VPLA para a maioria dos casos. Os regimes otimizados incluÃram nenhum ou apenas um desbaste e forneceram VPLA de 2.753 e 158 reais por ha e TIR de 22,9% e 2,9%, para os sÃtios I e IV, respectivamente. Concluiu-se que o número ideal de desbastes é reduzido em sÃtios com qualidade inferior, e quanto menos produtivo for o sÃtio, mais tardio será o ano ideal para o corte raso. A taxa de atratividade é um parâmetro que contribui para a determinação de regimes de desbaste, pois quanto maior for essa taxa, maior deve ser o número de desbastes, bem como mais precoces devem ser suas aplicaçõe
Planejamento, análise econômica e pesquisa operacional da teca.
Descrição do SisTeca; Diagrama de Manejo da Densidade no SisTeca; Descrição do SisILPF_Teca; A base estatÃstica dos softwares
Desempenho das cultivares de milho BRS Planalto e BRS Missões nas safras 2003/04 e 2004/05.
bitstream/CNPT-2010/40543/1/p-co178.pd
Effect of inclusion of distillers dried grains and solubles from barley, wheat and corn in isonutritive diets on the performance and caecal environment of growing rabbits
[EN] To evaluate how the dietary inclusion of distillers dried grains and solubles (DDGS) could affect the performance and caecal environment of growing rabbits, four experimental diets were formulated from a control diet without DDGS (C), including 20% of barley DDGS (Db20), 20% of wheat DDGS (Dw20) and 20 (Dc20) or 40% (Dc40) of corn DDGS. Animals had free access to medicated versions of the diets until 49 d, and then to unmedicated diets until 59 d of age. The performance trial was done using 475 three-way crossbred weaned rabbits of 28 d of age, individually housed in 5 batches. Caecal fermentation traits were determined in 20 animals per diet and at 42 d and at 59 d of age. No significant effect of the growing diet on mortality, morbidity or sanitary risk index was observed. In the whole period and respect to the control group, animals fed with Db20 showed higher dry matter (DM) and digestible energy (DE) intake (+6 and +12%, respectively; P<0.05), but similar daily weight gain (DWG) and increased feed conversion ratio (+9%; P<0.05). Similarly, and regardless of its inclusion level, the increase in DE intake of animals fed with corn DDGS (+9, respectively; P<0.05) did not increase DWG. In contrast, higher DM and DE intake of animals fed with Dw20 (+8; P<0.05) resulted in a higher DWG (+2.8 g/d; P<0.05) than those fed with C. Although inclusion of DDGS at 20% did not affected main caecal parameters controlled at 42 d, caecum of animals fed with the diet Dc40 was characterized by greater N-NH3 and valeric acid and lower total volatile fatty acids and acetic acid concentrations than the average of the other groups (on av. +5.2±1.7 mmol/L, +0.29±0.07 mol/100 mol, –17.17±4.41 μmol/L and –2.60±0.99 mol/100 mol, respectively; P<0.05). At 59 d of age, higher caecal DM, and propionic and valeric acid concentration and lower values of total volatile fatty acids and acetic/propionic rate were observed for DDGS inclusion at 20% compared to the control (+1.6±0.5%, +0.95±0.44 mol/100 mol, –9.3±4.3 μmol/L and –2.7±1.2, respectively; P<0.05). Linear inclusion of corn DDGS increased caecal DM, propionic acid proportion and total volatile fatty acids concentration and reduced acetate/propionic rate (+4.0±0.4%, +2.27±0.41 mol/100 mol, –21.27±3.9 μmol/L and –5.6±1.1, respectively for Dc40 compared to C; P<0.05). Rabbits given Dc40were also characterized for a greater caecum N-NH3 content than the other groups (on av. –8.7±1.7 mmol/L; P<0.05) at 59 d of age. The results of the present work reveal that inclusion of DDGS up to 20%, independently of the grain source (barley, wheat or corn), could be an interesting alternative in balanced diets for growing rabbits.The authors are much obliged to the European Commission for the PhD grant from the ARBOPEUE EMECW Programme, which made this work possible. This study was also supported by the Interministerial Commission for Science and Technology (CICYT) of the Spanish Government (AGL2011-30170-C02-01).Alagón, G.; Arce, ON.; MartÃnez-Paredes, E.; Ródenas, L.; Cervera, C.; Pascual, JJ. (2014). Effect of inclusion of distillers dried grains and solubles from barley, wheat and corn in isonutritive diets on the performance and caecal environment of growing rabbits. World Rabbit Science. 22(3):195-205. https://doi.org/10.4995/wrs.2014.1458SWORD19520522
Spitzer mapping of molecular hydrogen pure rotational lines in NGC 1333: A detailed study of feedback in star formation
We present mid-infrared spectral maps of the NGC 1333 star forming region,
obtained with the the Infrared Spectrometer on board the Spitzer Space
Telescope. Eight pure H2 rotational lines, from S (0) to S (7), are detected
and mapped. The H2 emission appears to be associated with the warm gas shocked
by the multiple outflows present in the region. A comparison between the
observed intensities and the predictions of detailed shock models indicates
that the emission arises in both slow (12 - 24 km/s) and fast (36 - 53 km/s)
C-type shocks with an initial ortho-to-para ratio of ~ 1. The present H2
ortho-to-para ratio exhibits a large degree of spatial variations. In the
post-shocked gas, it is usually about 2, i.e. close to the equilibrium value (~
3). However, around at least two outflows, we observe a region with a much
lower (~ 0.5) ortho-to-para ratio. This region probably corresponds to gas
which has been heated-up recently by the passage of a shock front, but whose
ortho-to-para has not reached equilibrium yet. This, together with the low
initial ortho-to-para ratio needed to reproduce the observed emission, provide
strong evidence that H2 is mostly in para form in cold molecular clouds. The H2
lines are found to contribute to 25 - 50% of the total outflow luminosity, and
thus can be used to ascertain the importance of star formation feedback on the
natal cloud. From these lines, we determine the outflow mass loss rate and,
indirectly, the stellar infall rate, the outflow momentum and the kinetic
energy injected into the cloud over the embedded phase. The latter is found to
exceed the binding energy of individual cores, suggesting that outflows could
be the main mechanism for core disruption.Comment: Accepted for publication in the Astrophysical Journa
AMI-LA radio continuum observations of Spitzer c2d small clouds and cores: Perseus region
We present deep radio continuum observations of the cores identified as
deeply embedded young stellar objects in the Perseus molecular cloud by the
Spitzer c2d programme at a wavelength of 1.8 cm with the Arcminute Microkelvin
Imager Large Array (AMI-LA). We detect 72% of Class 0 objects from this sample
and 31% of Class I objects. No starless cores are detected. We use the flux
densities measured from these data to improve constraints on the correlations
between radio luminosity and bolometric luminosity, infrared luminosity and,
where measured, outflow force. We discuss the differing behaviour of these
objects as a function of protostellar class and investigate the differences in
radio emission as a function of core mass. Two of four possible very low
luminosity objects (VeLLOs) are detected at 1.8 cm.Comment: 18 pages, 9 figures, accepted MNRA
Validation of a small-animal PET simulation using GAMOS: a Geant4-based framework
onte Carlo-based modelling is a powerful tool to help in the design and optimization of positron emission tomography (PET) systems. The performance of these systems depends on several parameters, such as detector physical characteristics, shielding or electronics, whose effects can be studied on the basis of realistic simulated data. The aim of this paper is to validate a comprehensive study of the Raytest ClearPET small-animal PET scanner using a new Monte Carlo simulation platform which has been developed at CIEMAT (Madrid, Spain), called GAMOS (GEANT4-based Architecture for Medicine-Oriented Simulations). This toolkit, based on the GEANT4 code, was originally designed to cover multiple applications in the field of medical physics from radiotherapy to nuclear medicine, but has since been applied by some of its users in other fields of physics, such as neutron shielding, space physics, high energy physics, etc. Our simulation model includes the relevant characteristics of the ClearPET system, namely, the double layer of scintillator crystals in phoswich configuration, the rotating gantry, the presence of intrinsic radioactivity in the crystals or the storage of single events for an off-line coincidence sorting. Simulated results are contrasted with experimental acquisitions including studies of spatial resolution, sensitivity, scatter fraction and count rates in accordance with the National Electrical Manufacturers Association (NEMA) NU 4-2008 protocol. Spatial resolution results showed a discrepancy between simulated and measured values equal to 8.4% (with a maximum FWHM difference over all measurement directions of 0.5 mm). Sensitivity results differ less than 1% for a 250–750 keV energy window. Simulated and measured count rates agree well within a wide range of activities, including under electronic saturation of the system (the measured peak of total coincidences, for the mouse-sized phantom, was 250.8 kcps reached at 0.95 MBq mL−1 and the simulated peak was 247.1 kcps at 0.87 MBq mL−1). Agreement better than 3% was obtained in the scatter fraction comparison study. We also measured and simulated a mini-Derenzo phantom obtaining images with similar quality using iterative reconstruction methods. We concluded that the overall performance of the simulation showed good agreement with the measured results and validates the GAMOS package for PET applications. Furthermore, its ease of use and flexibility recommends it as an excellent tool to optimize design features or image reconstruction techniques
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