Trace elements in skin of Dall's porpoises (Phocoenoides dalli) from the northern waters of Japan: an evaluation for utilization as non-lethal tracers

Concentrations of Fe, Zn, Cu, Se, Mn, Mo, Hg, Cd, Cr, Ag, Pb, Sr and V were determined in skins of Dall's porpoises (Phocoenoides dalli) of the Pacific coast truei-type population (PT population) (N=45), and the Sea of Japan-Okhotsk dalli-type population (JD population) (N=31) from the northern waters of Japan. Cutaneous Hg concentrations in both PT and JD populations were significantly correlated with age, indicating a possible alternative method of age estimation. A significant correlation was also noted between Hg concentrations in skin and liver, suggesting that biopsy samples of skin can provide a non-lethal surrogate for monitoring Hg contamination in this species. Trace element accumulation patterns differed strongly between PT and JD populations, when analyzed by principal component analysis, suggesting these patterns could be utilized as non-lethal tracers of population identification.     

Proximity of adult children to their parents in Great Britain

Much of the authors' knowledge of kin interaction and exchange in Britain is partial, in that it is based on studies of co-resident groups and excludes consideration of kin "beyond the household". It is known that there have been large declines in intergenerational co-residence, raising fears that family bonds have weakened. It is also commonly assumed that family members are less likely to live in close proximity than in the past. In this paper the authors examine one important aspect of kin relationships--proximity of adult children to their parents--using nationally representative data from 1986, 1995, and 1999. The analyses presented focus on: differences between 1986, 1995, and 1999 in proximity of adults to their parents; sociodemographic characteristics associated with variations in proximity, and temporal differences in the pattern of these variations. The paper concludes with an assessment of some of the policy implications of the findings.     

Branch migration and the international dispersal of families

This paper discusses the dispersal of facilities where family members migrate to different destination countries. Terminology for internationally dispersed families is proposed, and the term branch migration is suggested for the migration of related people from the same source country to different destination countries. Data from two 1993 surveys of senior secondary students show that 22% of Sydney students and 20% of Hong Kong students have relatives in two or more other countries. The data suggest that many Asian migrant families have branched between the US, Canada, Australia and other migrant-receiving nations. The causes and implications of the international dispersal of families are discussed.     

Recent Changes in the Near-Infrared Structure of eta Carinae

I present the first results from a Hubble Space Telescope/NICMOS imaging study of the most metal-poor blue compact dwarf galaxy, I Zw 18. The near-infrared color-magnitude diagram (CMD) is dominated by two populations, one 10-20 Myr population of red supergiants and one 0.1-5 Gyr population of asymptotic giant branch stars. Stars older than 1 Gyr are required to explain the observed CMD at the adopted distance of 12.6 Mpc, showing that I Zw 18 is not a young galaxy. The results hold also if the distance to I Zw 18 is significantly larger. This rules out the possibility that I Zw 18 is a truly young galaxy formed recently in the local universe.     

A Measurement of Omega from the North American Test Flight of Boomerang

We use the angular power spectrum of the cosmic microwave background, measured during the North American test flight of the Boomerang experiment, to constrain the geometry of the universe. Within the class of cold dark matter models, we find that the overall fractional energy density of the universe Omega is constrained to be 0.85相似文献   

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