27 resultados para I Belong in the LLB

em DigitalCommons@University of Nebraska - Lincoln


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The most significant cetacean trade items until commercial whaling all but ceased in the 1990s (aside from scientific exchanges of tissues etc.) were meat and blubber from baleen whales for human consumption. Since then, live dolphins and 'small' whales for display (and to some extent for research, military use, and 'therapy') have become the most significant cetacean 'products' in international trade. Trade in live cetaceans is presently dominated by bottlenose dolphins (Tursiops spp.), beluga whales (Debhinapterns leucas) and to a lesser extent killer whales (Orcinus orca) (Fisher and Reeves 2005). In the past, most of the dolphins in trade were common bottlenose dolphins (Tursiops truncatus) originating in the United States, Mexico and the Black Sea, but since the 1980s the United States has essentially stopped its capture-for-export activities and in 2001Mexico implemented a moratorium on live-captures. The source countries for dolphins in trade are now geographically diverse, but Cuba and Japan are currently major source nations for common bottlenose dolphins. Russia is the only current source for belugas. Russia and Japan have become the main potential sources for killer whales since Iceland ceased exporting them in the 1980s or early 1990s.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The reproductive habits of the wolverine, largest of the terrestrial mustelids, have remained largely unknown. Recently Rausch (1953) has concluded that the American and European wolverines belong to the same species (Gulo gulo). In this paper, the reproduction of this species is investigated.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Mycobacterium bovis infects the wildlife species badgers Meles meles who are linked with the spread of the associated disease tuberculosis (TB) in cattle. Control of livestock infections depends in part on the spatial and social structure of the wildlife host. Here we describe spatial association of M. bovis infection in a badger population using data from the first year of the Four Area Project in Ireland. Using second-order intensity functions, we show there is strong evidence of clustering of TB cases in each the four areas, i.e. a global tendency for infected cases to occur near other infected cases. Using estimated intensity functions, we identify locations where particular strains of TB cluster. Generalized linear geostatistical models are used to assess the practical range at which spatial correlation occurs and is found to exceed 6 in all areas. The study is of relevance concerning the scale of localized badger culling in the control of the disease in cattle.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Cucullanus palmeri n. sp. is described from the shortnose batfish, Ogcocephalus nasutus, in the Gulf of Mexico. This species is anatomically most similar to Cucullanus gendrei but differs from it in having a shorter esophagus and longer tail. Males differ in having a smaller gubernaculum and a different arrangement of a lateral caudal papilla. Cucullanus palmeri is readily distinguished from Cucullanus lophii, also from a lophiform fish host, in that the deirids and excretory pore are not posterior to the posterior end of the esophagus like in C. lophii.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Gonadal maturation of cobia, Rachycentron canadum, was evaluated by examining 508 specimens from its recreational fishery. Specimens were collected off southeast Louisiana to northwest Florida by hook-and-line during February through October 1987-1991. Fork lengths (FL) of these fish ranged from 580-1,530 mm, with corresponding weights of 2.0-43.5 kg. The female:male ratio was 1:0.37. Using a combination of oocyte size frequency and histological assessment of many of the fish, we determined that females were ripe from May through September, with atretic oocytes occurring in some fish from July through October. Degenerating hydrated oocytes in July and October and the presence of resting ovaries in July suggest two major spawning periods; however, monthly gonosomatic indices peaking in May, followed by a steady decline, do not support that finding. Ovaries were placed into undeveloped, early developing, mid-developing, or late developing categories based upon oocyte size-frequency distributions. Developing ovaries had two or three modes of oocytes larger than 30 μm. Batch fecundity was estimated to be 2.6×106 - 1.91×108 oocytes, depending on the size of fish/ovaries. The smallest female with oocytes exhibiting vitellogenesis was 834 mm FL. This fish was 2 years old based its otolith evaluation. The smallest male with an abundance of spermatozoa in its testes was 640 mm FL and 1 year old based on otolith evaluation; smaller males were not examined. Females larger than 840 mm FL had vitellogenic oocytes in March and April. A few fish still had vitellogenic oocytes in early October, but none did by late October. When Gilson’s fluid was used to assess ovarian tissue, the fresh weight of the tissue was reduced by 20% after being stored for 3 months. The diameter of oocytes shrunk about 25% in Gilson’s fluid which was 11% less than those fixed in formalin, embedded in paraffin, and sectioned. Tissue sections from specific individuals, each demonstrating a variety of different developmental stages, were similar regardless of whether they were obtained from the anterior, middle, or posterior portion of either ovary.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Juveniles of Contracaecum multipapillatum infected the Mayan cichlid (Cichlasoma urophthalmus) and adults infected the olivaceous cormorant (Phalacrocorax olivaceus) and the great egret (Casmerodius albus) in the coastal lagoon at Celestun, State of Yucatan, Mexico. All are new host records, and, even though the geographic locality record of Mexico for the species has not been published, unidentified but presumably conspecific specimens have been reported from there. When juveniles of C. multipapillatum were fed to a kitten, but not rats, ducks, or chickens, they developed into adults. Measurements and morphological data are provided on the specimens from the kitten. Development of an avian ascaridoid in the intestine of a mammal increases the potential of this widespread species to infect other mammals, including humans.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We report Phrixocephalus cincinnatus, a pennellid copepod infecting the eyes of flatfishes, from a single specimen of rex sole, Glyptocephalus zachirus, for the first time. In the typical host, the arrowtooth flounder, Atherestes stomias, the parasite occurred commonly in sampled populations from the Broughton Archipelago in British Columbia, infected primarily the right eye of the flounder, and on only one occasion presented more than two parasites per eye. The copepod attached to the choroid layer and ramified throughout the posterior compartment of the eye, resulting in the disruption of the retina and probably impairing host vision. Inflammation and hyperplasia progressed to necrosis and proliferation of connective tissue, resulting in the total destruction of the eye.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Oocysts of Eimeria funduli were studied by transmission electron microscopy in naturally-infected livers of the Gulf killifish, Fundulus grandis. Tissues were cryo-processed because membranous structures in the oocyst appear to hinder routine fixation and embedment. The oocyst wall (about 25 nm thick) was adjacent to the host cell and consisted of an outer membrane that limited the host cell cytoplasm and an inner membrane separated from the outer membrane by a narrow space. In some specimens, dense material was applied to the inner face of the inner membrane. Individual sporocysts were surrounded by a membranous "veil" (about 25 nm thick) that consisted of two unit membranes. Sporopodia, projections of the sporocyst wall, supported the veil. The sporocyst wall (130-150 nm thick) consisted of two layers, a thin electron-lucent outer layer (about 10 nm thick) and a thick electron dense inner layer (about 130 nm thick). Depending on the plane of section, the inner layer had transverse striations with periods of 3 to 4 nm or 12 to 15 nm. A narrow fissure, broadest at the anterior pole of the sporocyst, extended about one-third the length of the sporocyst wall. The posterior pole of the sporocyst was characterized by a bulbous swelling. Although this swelling resembled a Stieda body in light microscopic preparations, ultrastructurally, the swelling was a knoblike thickening in the sporocyst wall and did not plug a gap in this wall

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Sebekia mississippiensis sp. n. is described from Alligator mississippiensis in Louisiana, Mississippi, and Florida. Closely related to S. oxycephala in South American crocodilians, it differs by having a smaller and less spinous hook shield, a broader base for the posterior extensions of the oral cadre. and a thinner and more delicate tegument. The male reproductive system differs somewhat from that described for other pentastomids. Nymphs parasitize several fishes as well as turtles, snakes, and mammals.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The great whales of the Southern Ocean were extensively exploited by modern whaling methods, with the first catches made in the Falkland Islands Dependencies region of IWC Management Area II in 1904 (Tønnesson and Johnsen, 1982; Hart, 2006). Exploitation went through several phases. Populations of humpback whales, Megaptera novaeangliae, and blue whales, Balaenoptera musculus, around South Georgia crashed around the time of World War I, and further exploitation occurred in other regions into the 1930’s. There was a hiatus in whaling during World War II, but large-scale catches resumed in Antarctic waters after 1945.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

1. Blue whale locations in the Southern Hemisphere and northern Indian Ocean were obtained from catches (303 239), sightings (4383 records of ≥ 8058 whales), strandings (103), Discovery marks (2191) and recoveries (95), and acoustic recordings. 2. Sighting surveys included 7 480 450 km of effort plus 14 676 days with unmeasured effort. Groups usually consisted of solitary whales (65.2%) or pairs (24.6%); larger feeding aggregations of unassociated individuals were only rarely observed. Sighting rates (groups per 1000 km from many platform types) varied by four orders of magnitude and were lowest in the waters of Brazil, South Africa, the eastern tropical Pacific, Antarctica and South Georgia; higher in the Subantarctic and Peru; and highest around Indonesia, Sri Lanka, Chile, southern Australia and south of Madagascar. 3. Blue whales avoid the oligotrophic central gyres of the Indian, Pacific and Atlantic Oceans, but are more common where phytoplankton densities are high, and where there are dynamic oceanographic processes like upwelling and frontal meandering. 4. Compared with historical catches, the Antarctic (‘true’) subspecies is exceedingly rare and usually concentrated closer to the summer pack ice. In summer they are found throughout the Antarctic; in winter they migrate to southern Africa (although recent sightings there are rare) and to other northerly locations (based on acoustics), although some overwinter in the Antarctic. 5. Pygmy blue whales are found around the Indian Ocean and from southern Australia to New Zealand. At least four groupings are evident: northern Indian Ocean, from Madagascar to the Subantarctic, Indonesia to western and southern Australia, and from New Zealand northwards to the equator. Sighting rates are typically much higher than for Antarctic blue whales.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Stomach contents were analyzed from 127 Baird’s beaked whales, Berardizls bairdii, taken in coastal waters of Japan. During late July-August of 1985- 1987, 1989, and 1991, 107 samples were collected from off the Pacific coast of Honshu. An additional 20 samples were collected from whales taken in the southern Sea of Okhotsk during late August-September of 1988 and 1989. Prey identification using fish otoliths and cephalopod beaks revealed the whales fed primarily on deep-water gadiform fishes and cephalopods in both regions. Prey species diversity and the percentage of cephalopods and fish differed between the two regions. Off the Pacific coast of Honshu the whales fed primarily on benthopelagic fishes (81.8%) and only 18.0% on cephalopods. Eight species of fish representing two families, the codlings (Moridae) and the grenadiers (Macrouridde), collectively made up 81.3% of the total. Thirty species of cephalopods representing 14 families made up 12.7%. In the southern Sea of Okhotsk, cephalopods accounted for 87.1% of stomach contents. The families Gonatidae and Cranchiidae were the predominant cephalopod prey, accounting for 86.7% of the diet. Gadiform fish accounted for only 12.9% of the diet. Longfin codling, Laernonma longipes, was the dominant fish prey in both regions. Depth distribution of the two commonly consumed fish off the Pacific coast of Honshu indicate the whales in this region fed primarily at depths ranging from 800 to 1,200 m.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The title of this volume promises more than the content delivers. The heart of the book is information from Ward's 1992 University of Chicago doctoral dissertation, which focused on the social and cultural reasons leading to students dropping out of school. Her first two chapters provide a good review of research on dropouts and Indian education; the following six focus on the results of her 1987-1989 study of 698 Northern Cheyenne, Crow, and white high school students attending the Colstrip Public, St. Labre Catholic, and Busby Tribal Schools in Montana. Fifty-two percent of the students in this study were Indian, with a dropout rate of 45% .

Relevância:

100.00% 100.00%

Publicador:

Resumo:

There is compelling evidence that Planet Earth is on the path to an era of global warming that has serious implications for the well-being of both people and nature. This three-volume synthesis of literature will be a marvelous place for both the public and new scholars interested in global warming to begin their pursuit of the subject. The author captures the best of the scientific literature and press materials appearing in recent years. The utility of these volumes as a resource for gaining a broad background or pursuing a particular aspect of global warming is enhanced by Johansen's talent for explaining with clarity a vast and rapidly growing subject.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

For all intents and purposes, the settlement of the Canadian prairie was the founding of a new society using materials brought to the new land along with those close at hand. Of course, preexisting aboriginal society had to be supplanted in the course of this founding. In both the supplanting and the founding, the rule of law as we currently know it was a principal means and end of the settlement process.