814 resultados para Fur-bearing animals.
Resumo:
We examined the summer distribution of marine mammals off the northern Washington coast based on six ship transect surveys conducted between 1995 and 2002, primarily from the NOAA ship McArthur. Additionally, small boat surveys were conducted in the same region between 1989 and 2002 to gather photographic identification data on humpback whales (Megaptera novaeangliae) and killer whales (Orcinus orca) to examine movements and population structure. In the six years of ship survey effort, 706 sightings of 15 marine mammal species were made. Humpback whales were the most common large cetacean species and were seen every year and a total of 232 sightings of 402 animals were recorded during ship surveys. Highest numbers were observed in 2002, when there were 79 sightings of 139 whales. Line-transect estimates for humpback whales indicated that about 100 humpback whales inhabited these waters each year between 1995 and 2000; in 2002, however, the estimate was 562 (CV= 0.21) whales. A total of 191 unique individuals were identified photographically and mark recapture estimates also indicated that the number of animals increased from under 100 to over 200 from 1995 to 2002. There was only limited interchange of humpback whales between this area and feeding areas off Oregon and California. Killer whales were also seen on every ship survey and represented all known ecotypes of the Pacific Northwest, including southern and northern residents, transients, and offshore-type killer whales. Dall’s porpoise (Phocoenoides dalli) were the most frequently sighted small cetacean; abundance was estimated at 181−291 individuals, except for 2002 when we observed dramatically higher numbers (876, CV= 0.30). Northern fur seals (Callorhinus ursinus) and elephant seals (Mirounga angustirostris) were the most common pinnipeds observed. There were clear habitat differences related to distance offshore and water depth for different species.
Resumo:
Hermaphroditism, a phenomenon in which one and the same individual produces sperms, the male gamate the ovum, the female gamate, is generally common in plants and lower animals and hence is considered as a primitive character. However, it is rare in higher invertebrates such as insects, spiders, prawns and also in the lower vertebrates to which fishes belong. Prawns and fishes have highly evolved reproductive systems and occur as separate individuals of males and females. Both these groups do have some species which are regurarly hermaphrodites and others which are teratologically hermaphrodites.
Resumo:
The potential use of YBa2Cu3C7as an active component in a magnetic bearing is being investigated. Measurements are being made of the load bearing capacity and related stiffnesses in comparison to predictions from the critical state model. Although the load bearing capacity is high and increases with the square of the magnetic field trapped the stiffness is low. We report on a novel design concept to overcome this problem. © 1995 IEEE
Resumo:
The use of a superconducting magnetic bearing in an Urenco Power Technologies (UPT) 100kW flywheel is being studied. The dynamics of a conventional flywheel energy storage system have been studied at low frequencies. We show that the main design consideration is overcoming drag friction losses and parasitic resonances. We propose an original superconducting magnetic bearing design and improved cryogenic motor cooling to increase stability and decrease energy losses in the system. © 2008 IOP Publishing Ltd.
Resumo:
Thirteen restriction endonucleases were used to investigate nucleotide sequence variation in the 18S rRNA DNA of 88 individuals from ten Sarcocystis taxa collected as cysts from their intermediate hosts, swine, cattle and water buffalo. A DNA sequence of
On the dynamic thermal state in a hydrodynamic bearing with a whirling journal using CFD techniques,