3 resultados para íon Fe (II)

em DigitalCommons@University of Nebraska - Lincoln


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I. Gunter and Christmas (1973) described the events leading to the stranding of a baleen whale on Ship Island, Mississippi, in 1968, giving the species as Balaenopteru physalus, the Rorqual. Unfortunately the identification was in error, but fortunately good photographs were shown. The underside of the tail was a splotched white, but there was no black margin. The specimen also had fewer throat and belly grooves than the Rorqual, as a comparison with True’s (1904) photograph shows. Dr. James Mead (in litt.) pointed out that the animal was a Sei Whale, Balaenoptera borealis. This remains a new Mississippi record and according to Lowery’s (1974) count, it is the fifth specimen reported from the Gulf of Mexico. The stranding of a sixth Sei Whale on Anclote Keys in the Gulf, west of Tarpon Springs, Florida on 30 May 1974, was reported in the newspapers and by the Smithsonian Institution (1974). II. Gunter, Hubbs and Beal (1955) gave measurements on a Pygmy Sperm Whale, Kogia breviceps, which stranded on Mustang Island on the Texas coast and commented upon the recorded variations of proportional measurements in this species. Then according to Raun, Hoese and Moseley (1970) these questions were resolved by Handley (1966), who showed that a second species, Kogia simus, the Dwarf Sperm Whale, is also present in the western North Atlantic. Handley’s argument is based on skull comparisons and it seems to be rather indubitable. According to Raun et al. (op. cit.), the stranding of a species of Kogia on Galveston Island recorded by Caldwell, Ingles and Siebenaler (1960) was K. simus. They also say that Caldwell (in litt.) had previously come to the same conclusion. Caldwell et al. also recorded another specimen from Destin, Florida, which is now considered to have been a specimen of simus. The known status of these two little sperm whales in the Gulf is summarized by Lowery (op. cit.).

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This paper reports the results of a comparative study of the development of the larval Echinococcus multilocularis Leuckart, 1863), and associated tissue reaction in naturally and experimentally infected mammals representing 31 species. The histogenesis of the larval cestode was traced in detail in arvicoline rodents of several species, and interspecific differences were defined. In arvicoline rodents, the developing larva exhibited host-specific characteristics within about a month after infection was established. The tissue reaction in Microtus oeconomus was characterized by the production of a large quantity of detritus around the larva, and by the formation of a thick epithelioid zone. In one subspecies, M. oeconomus innuitus, development of the larva was retarded, and the detrital mass was often calcified; in another, M. oeconomus operarius, the detritus rarely became calcified and the larva proliferated more rapidly. In M. pennsylvanicus, the tissue reaction was minimal, and little detritus was present. The characteristics of the tissue reaction in M. montebelli placed it in an intermediate position between the aforementioned species. In Clethrionomys rutilus, a thin epithelioid zone and an outer zone of loose collagenous fibers composed the adventitial layer; exogenous budding was retarded in this vole. A minimal tissue reaction occurred in Lagurus curtatus. In Lemmus spp., larger cysts were characteristic, but areas of small-cystic proliferation were always present. Similar differences in species or subspecies of Citellus and Dicrostonyx were described. Lesions of alveolar bydatid disease in man also were studied. The invasive growth of the larval cestode in the human liver involves a process comparable to small-cystic proliferation in the natural intermediate hosts. Although the later stages of development of the larval cestode are inhibited in man, exogenous proliferation of vesicles continues for the life of the host. The lesion in man was compared with a morphologically similar formation produced by anomalous development of the larval E. granulosus in the bovine liver. The latter is distinguished by the absence of areas of small-cystic proliferation. Non-echinococcal lesions found in the tissues studied, some of which resembled foci caused by the larval E. multilocularis, were briefly discussed.

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The helminths of North American mouse-like rodents have received little study. Previous work has been based on low numbers of animals examined, and there has been little reference to the ecology involved. The purpose of this paper is to present data resulting from the examination of over 600 voles, with special reference to host-parasite relationships