358 research outputs found
Guidance and Control Elements for Improved Access to Space:from Planetary Landers to Reusable Launchers
Caprino-ovinocultura de corte: manejo reprodutivo e sua importância para o sucesso da exploração.
bitstream/item/52256/1/PL-Aurino.pd
Eficiência produtiva de ovelhas deslanadas acasaladas com reprodutores especializados para corte.
Uncoupled GPS Road Constrained Positioning based on Constrained Kalman Filtering
Car navigation systems take advantage of the synergies between the Global Positioning System (GPS) and digital road maps. For this kind of applications the digital road maps can provide a priori information to improve the positioning accuracy. This paper presents a method for the estimation of the user’s position, based on GPS positioning estimates, constrained to a road map. A low-cost GPS receiver was assumed as being the source of the positioning information. The techniques used in the proposed estimator were developed taking in consideration that the platforms where typically they would be implemented are characterized by having reduced computational capabilities. The algorithm’s positioning accuracy was characterized based on real data from a low-cost GPS receiver installed in a car. Different scenarios were used in the field trials in order to evaluate the impact of the satellite constellation visibility and geometry in the algorithm’s performance
Atividade ovariana pós-parto em ovelhas Santa Inês sob diferentes manejos de amamentação na região semiárida do Nordeste.
Objetivou-se investigar o efeito de diferentes manejos de amamentação sobre a atividade ovariana pós-parto em ovelhas da raça Santa Inês por meio das concentrações circulantes de progesterona. Foram utilizadas 18 fêmeas com idade entre 22 e 72 meses. Após o parto, os cordeiros ficaram com as ovelhas até o 14º diae, a partir do 15º dia foram distribuídas em dois grupos: amamentação contínua (n=9) e controlada (n=9). As coletas de sangue para a dosagem de progesterona aconteceram a cada sete dias a partir do parto até o primeiro estro e, em seguida, a cada quatro dias até o segundo estro. Houve atividade ovulatória silenciosa antes do primeiro estro pós-parto em 85,70% (5/9) e 25% (3/9) das fêmeas em amamentação contínua e controlada, respectivamente. As ovelhas com amamentação contínua apresentaram o estro mais tardiamente (37,71±3,34 dias) do que as com mamada controlada (26,12±2,4 dias). As concentrações plasmáticas de progesterona entre o parto e o primeiro estro foram 2,81±1,58ng/mL vs 1,45±0,59ng/mL e ao estro 0,25±0,34ng/mL vs 0,32±0,18ng/mL para amamentação contínua e controlada, respectivamente. Os níveis médios de progesterona entre o primeiro e o segundo estro pós-parto foram 1,53±0,54 ng/mL e 2,50±1,09ng/mL, para amamentação contínua e controlada, respectivamente, estes estros ocorreram em 77,7% vs 100% e 66.6% vs 100% das fêmeas, na mesma ordem. Conclui-se que a amamentação tem influência sobre a atividade Ovarian activity in Santa Inês sheep under different types of suckling in semi-arid area of Brazil ovariana pós-parto em ovelhas Santa Inês e ciclos curtos e silenciosos são necessários para uma atividade cíclica normal no pós-parto. Ovarian activity in Santa Inês sheep under different types of suckling in semi-arid area of Brazil. SUMMARY - Aiming to investigate the suckling effect on ovarian activity in postpartum Santa Inês ewes through progesterone levels, it was used 18 females aging between 22 and 72 months. After parturition, the lambs stayed with the dams until the 14th day and from the 15th day they were divided in two treatments: continuous and controlled suckling. The blood collection for progesterone happened each seven days from parturition until the first estrous, and, thereafter, each 4 days until the second estrous. There was a silence ovulatory activity before the first postpartum estrous in 85.70% and 25% of the animals submitted to continuos and controlled suckling, while the occurrence of first estrous in the first group was delayed (37.71±3.34 days) in relation to controlled suckling group (26.12±2.4 days). The progesterone average levels between the parturition and the first estrous postpartum were 2.81±1.58ng/mL versus 1.45±0.59ng/mL, and on estrous were 0.25±0,34ng/mL versus 0,32±0,18ng/mL, for females under continuos and controlled suckling, respectively. The progesterone average levels between the first and the second estrous postpartum were 1.53±0.54ng/mL and 2.50±1.09ng/mL, for females under continuos and controlled suckling, espectively, happened these estrous in 77.7% versus 100% and 66.6% versus 100% for females, in the same order. It is concluded that suckling stimuli has influence on the postpartum ovarian activity in Santa Inês ewes and short and silent cycles are necessaries to normal postpartum ovarian cyclic
Preparation of controlled release microspheres using supercritical fluid technology for delivery of anti-inflammatory drugs
Ethylcellulose/methylcellulose blends were produced using different precipitation techniques and impregnated with naproxen, a non-steroidal
anti-inflammatory drug (NSAID). Solvent-evaporation technique was used not only for the preparation of ethylcellulose/methylcellulose microspheres
but also to encapsulate naproxen. Supercritical fluid (SCF) impregnation was also performed to prepare naproxen loaded microspheres. The
microspheres, impregnated by the SCF technique, were prepared both by solvent-evaporation and by a supercritical antisolvent (SAS) process. In
vitro release profiles at pH 7.4 and 1.2, of naproxen-loaded microspheres were evaluated and the results were modelled Fick’s law of diffusion and
Power law. Miscrospheres prepared by supercritical antisolvent have a higher loading capacity and present a slower release profile. The systems
studied present a release mechanism controlled by drug diffusion which complies Fick’s law of diffusion
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