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Hunting behavior of a marine mammal beneath the antarctic fast Ice   总被引:1,自引:0,他引:1  
The hunting behavior of a marine mammal was studied beneath the Antarctic fast ice with an animal-borne video system and data recorder. Weddell seals stalked large Antarctic cod and the smaller subice fish Pagothenia borchgrevinki, often with the under-ice surface for backlighting, which implies that vision is important for hunting. They approached to within centimeters of cod without startling the fish. Seals flushed P. borchgrevinki by blowing air into subice crevices or pursued them into the platelet ice. These observations highlight the broad range of insights that are possible with simultaneous recordings of video, audio, three-dimensional dive paths, and locomotor effort.  相似文献   
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Development of the foetal respiratory system includes both pulmonary growth and maturation. In human medicine, a higher incidence of respiratory distress is reported in newborn males. This study aimed to identify different phases of canine foetal lung maturation throughout pregnancy, to determine the stage of pregnancy in which surfactant production begins and to compare pulmonary development of male and female foetuses. Pregnant bitches (34) were subjected to elective ovariohysterectomy and allocated into four groups, according to the stage of pregnancy: 30–40 days of pregnancy (n = 10), 41–50 days (n = 10), 51–60 days (n = 10) and bitches in the first stage of parturition (n = 4). Foetal lungs were histologically processed and evaluated by optical microscopy. The pseudoglandular phase was identified between the 35th day and 46th day of gestation; the onset of canalicular and saccular periods was observed, respectively, from the 48th day and 60th day of pregnancy. Lungs from foetuses at term were in the saccular phase; thus, the development into the alveolar period occurs in the neonatal period. The histological analyses revealed that respiratory tract development is centrifugal, from upper to lower airways. Therefore, it is possible to identify distinct development periods in different portions of the same organ. In conclusion, the saccular phase of lung development begins around 57 and 60 days of pregnancy, the period in which surfactant production is believed to occur. Male and female foetuses present similar pulmonary development from early pregnancy until parturition.  相似文献   
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Conservation of threatened animals is frequently limited by lack of knowledge about their ecological preferences, and often artificial feeding is one of the few chances to save endangered species. We investigated the possibility to artificially feed two endangered flat bark beetles dependent on dead wood for their diet—namely, Cucujus cinnaberinus (Scopoli, 1763) and Cucujus haematodes Erichson, 1845—by examining their dietary preferences, life cycle duration, and survival in laboratory conditions. Individuals of the two species were caught in the wild and larvae and adults were fed in laboratory conditions by live or dead prey. Three species of saproxylic beetles: two cerambycids (Acanthocinus griseus Fabricius, 1793 and Rhagium inquisitor Linnaeus, 1758), one scolytid (Ips sexdentatus Börner, 1776) one tenebrionid (Tenebrio molitor (Linnaeus, 1758)) one dipteran (Lucilia sericata (Meigen, 1826)) and one ant (Lasius sp. Fabricius, 1804) were used as prey, with minced meat as a control. Our results indicated high survival and no difference in prey choice between the two flat beetle species. Larvae and adults preferred dead prey, but no significant preference was detected among dead prey taxa, supporting the hypothesis that the two species are opportunistic scavengers. Comparing data with previous results, both species and their developmental stages should be classified as obligate saproxylic organisms with preference to the dead and decaying organic material. Successful artificial feeding and rearing of these endangered species, followed by the release in the wild through rescue or reintroduction programs, therefore appear relevant for their protection and future conservation.  相似文献   
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A Monteggia fracture is a humero-radial luxation combined with a fracture of the ulna. It is a rare injury, infrequently reported in the horse. This case report describes the surgical repair of such a fracture in a 4-month-old filly.  相似文献   
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The presence of the zona pellucida has been perceived as a requirement for the oviductal transfer of cloned embryos at early stages of development while protecting the embryo from an immune system response. We hypothesized that steroid hormone therapy could reduce a potential cellular immune response after the transfer of zona‐free cloned embryos into the oviduct of recipient female goats. In Experiment 1, seven does were used to study the systemic immunosuppressant effect of the methylprednisolone administration (for 3 days) on blood cell counts. Whole blood was collected prior to treatment with methyprednisolone and then on Days 1, 2, 3, 4, 7, 14, 21 and 28 after the first dose of methylprednisolone for the analysis of haematological parameters. Methylprednisolone treatment significantly reduced circulating white blood cells and neutrophils in comparison with pre‐treatment levels, demonstrating a systemic immunosuppressant effect. In Experiment 2, a group of 58 does were used as recipient females to study the effect of administration of methylprednisolone for 3 days on the establishment of pregnancies after the transfer of zona‐free cloned embryos into the oviducts. No effects on pregnancy rates on Day 30 were observed regarding the distinct treatment groups (control vs. methylprednisolone), the source of oocytes (in vivo‐ vs in vitro‐matured) or the presence or absence of the zona pellucida in embryos. In summary, methylprednisolone was effective at inducing a systemic immunosuppressed state in goats, but the treatment prior to embryo transfer did not affect pregnancy rates. Moreover, pregnancy rates were similar between zona‐free and zona‐intact goat cloned embryos.  相似文献   
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The effect of maternal antibody to the toxin of Corynebacterium pseudotuberculosis, produced by caseous lymphadenitis (CLA) in ewes or by vaccinating ewes before lambing, on the efficacy of vaccination against CLA in their lambs was examined. Lambs were allocated to treatments according to either the vaccination history of their dam or level of CLA toxin antibody of their dam. They were vaccinated twice using 2 different inoculation regimes and then artificially infected with CLA organisms. The number of lambs with CLA lesions was assessed at slaughter. In one experiment high levels of CLA toxin antibody activity in ewes were associated with decreased efficacy of CLA vaccination in their lambs, when lambs were vaccinated at 2 and 8 weeks or 8 and 14 weeks of age. In a second experiment the efficacy of lamb vaccination at 8 and 12 weeks, but not at 14 and 18 weeks of age, was decreased. In sheep flocks with a high prevalence of CLA, vaccinating lambs against CLA at less than 10 weeks of age may not produce optimum protection against CLA in lambs. There was no difference in infection rate between lambs from vaccinated and unvaccinated ewes. However, vaccination of lambs at 2 and 8 wks was less effective that vaccination at 8 and 14 weeks, probably due to reduced immunocompetence in young lambs. In sheep flocks where significant numbers of lambs receive their primary vaccination at less than 3 weeks of age vaccination programmes to control CLA in lambs may be less effective.  相似文献   
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