Facies Structure and Quantitative Parameters of Pleistocene Sediments of the Bering Sea

Lithofacies zoning is described for the first time for the Neo- and Eopleistocene of the Bering Sea. Four lithofacies sedimentation zones are distinguished: (I) terrigenous; (II) siliceous–terrigenous; (III) siliceous, and (IV) volcanoterrigenous ones. Corresponding maps were treated using Ronov volumetric method to quantify sedimentation parameters for distinguished lithofacies zones (subzones) and types of Pleistocene sediments. It was revealed that terrigenous sediments predominate over other sediments. Accumulation of the terrigenous sediments was more intense (by 1.4 times) in the Neopleistocene than in the Eopleistocene. The sedimentation rate of siliceous sediments of the Bowers Ridge in the Eopleistocene was two times higher than in the Neopleistocene.     

The relation between typical concentrations of chemical constituents in potable water and their injurious limits

 There is an obvious similarity between the values of the typical concentrations of the inorganic and synthetic organic constituents in potable water and their injurious limits to human health. This similarity is attributed to the adaptation of man to his environment, i.e. it has resulted from natural selection. Received: 6 August 1999 · Accepted: 30 November 1999     

Evidence for short term changes in the intensity and spectrum of hard X-rays from Cyg X-1

The paper presents experimental evidence for the existence of fast intensity fluctuations with time scales of the order of a minute in the X-ray emission from Cyg X-1 at energies greater than 29 keV. Spectral variations over time intervals of 20–25 min are also observed in the same energy range. Whereas, similar intensity and spectral fluctuations have been reported earlier at lower energies the observations presented here is the first evidence for the existence of similar fluctuations at high energies.     

Urban–agricultural water appropriation: the Hyderabad, India case

With the urbanisation drive comes steady growth in urban water demand. Although in the past this new demand could often be met by tapping unclaimed water sources, this option is increasingly untenable in many regions where little if any unclaimed water remains. The result is that urban water capture, and the appropriation of associated physical and institutional infrastructure, now often implies conflict with other existing uses and users. While the urbanisation process has been studied in great depth, the processes and, critically, impacts of urban water capture and appropriation are not well researched or understood. This paper undertakes a critical examination of the specific case of Hyderabad, one of India's fastest growing cities, to shed light more generally on the process of water capture by cities and the resultant impacts on pre-existing claims, particularly agriculture. It does this by examining the history and institutional response to Hyderabad's urban–rural water contest; how the results of that contest are reflected in surface and groundwater hydrology; and the eventual impacts on agriculture. The findings show that the magnitude, and sometimes even direction, of impact from urban water transfer vary in space and time and depend on location-specific rainfall patterns, the nature of existing water infrastructure and institutions, and farmers' adaptive capacities and options, notably recourse to groundwater. Broader consideration of the specific findings provides insights into policy mechanisms to reduce the possible negative impacts from the global, and seemingly inexorable, flow of water to the world's growing cities.     

TRACKING THE BABY BOOM,THE BABY BUST,AND THE ECHO GENERATIONS: HOW AGE COMPOSITION REGULATES US MIGRATION*

US regional and state migration data from the 1940s–80s, when members of the baby boom generation aged into their years of peak labor force mobility, suggest ways in which changing age composition regulates geographical mobility and interregional migration. Labor supply pressure plays a key role in the dynamics of the national migration system. A “delayed mobility” effect in the 1980s similar to the delayed fertility of the baby boom cohorts appears to be a result of the depressed rates of mobility experienced by members of this generation when they flooded regional labor markets with record numbers of entrants in the 1970s. Recent temporal shifts in age-specific volumes of interregional migration help predict the future pace of migration based upon the projected age distribution of the nation.