967 resultados para Captive portal


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This study analyzed the effects of noise levels and number of visitors on the behaviors of a mother puma and her daughter in a zoo environment with respect to the time of day. The study monitored visitation (noise and number) over two 1-week periods (4 weeks between periods) and frequency of various puma behaviors (videorecorded). The study analyzed videotaped behavior of the pumas based on the time of day and visitors number and noise levels. There was a direct association of puma behaviors with visitors number and noise levels. The daughter puma was the most affected and behavioral changes of both pumas correlated more strongly with the noise level than the number of visitors. The noise level and number of visitors affected the behavior of the mother and her daughter only in the morning. The results of this study indicate that both noise level and number of visitors affected these pumas but revealed the noise as predominant. Moreover, the response of these pumas to visitors depended on the time of the day.

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Platynosomum illiciens (Trematoda, Plagiorchida) is a trematode parasite reported in felids and falconiforms. It was identified in the gall bladder of eight captive neotropical necropsied primates from the National Primate Center (CENP), Ananindeua, State of Para, Brazil. This is the first description of Platynosomum illiciens as a parasite of primates.

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This study examines the unpalatability of Hyla semilineata tadpoles, relating this possible defence mechanism to their black, presumably aposematic, colouration. Bullfrog tadpoles (Rana catesbeiana), similar in size to the H. semilineata larvae, were used as controls in the experiments. The palatability of H. semilineata tadpoles was tested by offering the tadpoles to Fish (Hoplias malabaricus), free-ranging passerine birds (Pitangus sulphuratus) and hawks (Buteo magnirostris), and domestic chickens (Gallus domesticus). All predators showed a significant preference towards the control R. catesbeiana tadpoles. However, in experiments with fish, this preference was not significant for tadpole capture, only for their ingestion, suggesting that the fish could not distinguish between the two species before tasting them. Although great kiskadees (P. sulphuratus) preferred the control R. catesbeiana tadpoles, they promptly ingested more than half of the test H. semilineata tadpoles when these were offered alone. The chickens, used as naive predators, clearly learned to avoid the black H. semilineata tadpoles after a few trials. The conspicuous colouration and unpalatability of H. semilineata tadpoles may benefit the individual as well as the group, depending on the predator involved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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In this paper we search for the dynamics of a simple portal structure in the free and in the periodic excitation cases. By using the Center Manifold approach and Averaging Method, we obtain results on both stability and bifurcation of equilibrium points and periodic orbits. (C) 2005 Elsevier Ltd. All rights reserved.

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In this paper, we examine the nonlinear control method based on the saturation phenomenon and of systems coupled with quadratic nonlinear ties applied to a shear-building portal plane frame foundation that supports an unbalanced direct cut-rent with limited power supply (non-ideal system). We analyze the equations of motion by using the method of averaging and numerical simulation. The interaction of the non-ideal structure with the saturation controller may lead to the occurrence of interesting phenomena during the forward passage through the several resonance states of the systems. Special attention is focused on passage through resonance when the non-ideal excitation frequency is near the portal frame natural frequency and when the non-ideal system frequency is approximately twice the controller frequency (two-to-one internal resonance).

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A practical problem of synchronization of a non-ideal (i.e. when the excitation is influenced by the response of the system) and non-linear vibrating system was posed and investigated by means of numerical simulations. Two rotating unbalanced motors compose the mathematical model considered here with limited power supply mounted on the horizontal beam of a simple portal frame. As a starting point, the problem is reduced to a four-degrees-of-freedom model and its equations of motion, derived elsewhere via a Lagrangian approach, are presented. The numerical results show the expected phenomena associated with the passage through resonance with limited power. Further, for a two-to-one relationship between the frequencies associated with the first symmetric mode and the sway mode, by using the variation of torque constants, the control of the self-synchronization and synchronization (in the system) are observed at certain levels of excitations.

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Eight Panthera onca (Po), 13 Felis concolor (Fc), 7 Felis yagouaroundi (Fy), 7 Felis tigrina (Ft) and 5 Felis pardalis (Fp) specimens from São Paulo State zoos were used. All animals were restrained with darts containing 10 mg/kg ketamine and 1 mg/kg xylazine. Venous blood samples were collected as soon as possible (within 15-20 min) and serum was frozen until the time for cortisol quantification. Cortisol was determined using a solid phase radioimmunoassay with an intra-assay coefficient of 8.51%. Data were analyzed statistically by the Kruskal-Wallis test, followed by Dunn's multiple comparisons test, and the one-sample t-test, with the level of significance set at P<0.05. Data are reported as means ± SEM. Cortisol levels differed among the captive felines: Po = 166 ± 33a, Fc = 670 ± 118b, Fy = 480 ± 83b, Ft = 237 ± 42ab, Fp = 97 ± 12a nmol/l (values followed by different superscript letters were significantly different (P<0.001)). Since most of the veterinary procedures on these species involve chemical restraint, these results show the necessity of preventive measures in order to minimize the effect of restraint stress on more susceptible species

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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O estudo da veia porta quanto aos vasos confluentes para sua formação e suas tributárias foi efetuado em 10 cutias (Dasyprocta aguti), adultas (3 fêmeas e 7 machos), nas quais o sistema desta veia foi injetado com látex corado, sendo a seguir fixadas em formol a 10% e dissecadas. Verificou-se que o tronco da veia porta origina-se sempre pela confluência de duas raízes, sendo representadas em 90% dos casos, pela veia lienal e pelo tronco mesentérico comum, constituído pelas veias mesentéricas cranial e caudal e, em 10%, pela veia lienal e pela veia mesentérica cranial. O tronco da veia porta recebe como tributárias a veia pancreaticoduodenal cranial (100%), a veia gástrica direita (90%) e, ainda, a veia gastroepiplóica direita (40%).

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The main purpose of the present study was to investigate the occurrence of antibodies against T gondii and N. caninum in captive maned wolves from Brazil, considering that little information is available at the literature about infections by these parasites in this wild animal. Serum samples were obtained from 59 maned wolves originated from six zoos and from one ecological reserve of the southeastern and midwestern regions of Brazil. To detect IgG antibodies against T gondii, an ELISA protocol was used and the results were expressed as ELISA reactivity indexes (131). Serology for N. caninum was carried out by indirect fluorescent antibody test (IFAT) and cut-off titers were established at 1:25 dilution. From the total of the analyzed samples, 44 (74.6%) were seropositive for T gondii and only 5 (8.5%) for N. caninum. Seropositivity for T gondii ranged from 0 to 100% in the seven different origin locals, with rates over 50% among the six zoos, whereas no positivity was found in the samples from ecological reserve. For N. caninum, seroprevalence varied from 0 to 50% in the different locals, with the highest rates also detected in zoos. Seroprevalence for T gondii was strongly related with age, with rates significantly higher among adult wolves (91.7%) when compared to newborn or young animals. Seropositive samples for N. caninum were found predominantly in adult wolves. For both parasites, seroprevalence did not show a significant distinction in relation to gender. Although seroprevalence for T gondii was significantly higher when compared to N. caninum in the Brazilian captive maned wolves tested, these findings reflect the great exposure of this species to T gondii and, in lower extension, to N. caninum. Also, the present study demonstrated for the first time the presence of antibodies to N. caninum in wild life from South America. (C) 2004 Elsevier B.V. All rights reserved.

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We present measurements of the non-linear oscillations of a portal frame foundation for a non-ideal motor. We consider a three-time redundant structure with two columns, clamped in their bases and a horizontal beam. An electrical unbalanced motor is mounted at mid span of the beam. Two non-linear phenomena are studied: a) mode saturation and energy transfer between modes; b) interaction between high amplitude motions of the structure and the rotation regime of a real limited power motor. The dynamic characteristics of the structure were chosen to have one-to-two internal resonance between the anti-symmetrical mode (sway motions) and the first symmetrical mode natural frequencies. As the excitation frequency reaches near resonance conditions with the 2nd natural frequency, the amplitude of this mode grows up to a certain level and then it saturates. The surplus energy pumped into the system is transferred to the sway mode, which experiences a sudden increase in its amplitude. Energy is transformed from low amplitude high frequency motion into high amplitude low frequency motion. Such a transformation is potentially dangerous.We consider the fact that real motors, such as the one used in this study, have limited power output. In this case, this energy source is said to be non-ideal, in contrast to the ideal source whose amplitude and frequency are independent of the motion of the structure. Our experimental research detected the Sommerfeld Effect: as the motor accelerates to reach near resonant conditions, a considerable part of its output energy is consumed to generate large amplitude motions of the structure and not to increase its own angular speed. For certain parameters of the system, the motor can get stuck at resonance not having enough power to reach higher rotation regimes. If some more power is available, jump phenomena may occur from near resonance to considerably higher motor speed regimes, no stable motions being possible between these two.

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The prevalence of Chlamydophila psittaci (formerly Chlamydia psittaci) infection was assessed in 95 apparently healthy, captive Amazon parrots from three breeder collections in southeastern and west-central Brazil. Cloacal swabs from 95 birds were tested for chlamydial antigen, which was detected by direct immunofluorescence (DIF), and serum samples from 44 of these birds were tested for antibodies to C. psittaci using an enzyme-linked immunosorbent assay. The prevalences of active infection as detected by DIF were 16.7%, 22.2%, and 56.1%, and seroprevalences were 100%, 87.5%, and 60% in flocks A, B, and C, respectively. We can therefore infer that C. psittaci may be widespread in captive parrot populations in Brazil.

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The gross anatomy of the portal vein (V. portae) and its tributaries was studied through anatomical methods, i.e. dissection, corrosion and diaphanization, in 45 opossums (Didelphis albiventris). In all animals the portal vein was formed by the junction of the cranial mesenteric, caudal mesenteric and lienal veins (V. mesenterica cranialis, V. mesenterica caudalis and V. lienalis, respectively). Many collateral tributaries were observed running into the portal venous trunk.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)