シリコンナノワイヤトランジスタにおけるキャリア伝導機構の研究

制度:新 ; 文部省報告番号:甲2624号 ; 学位の種類:博士(工学) ; 授与年月日:2008/3/15 ; 早大学位記番号:新478

Population Aging: Facts, Challenges, and Responses

The world’s population is growing older, leading us into uncharted demographic waters. There will be higher absolute numbers of elderly people, a larger share of elderly, longer healthy life expectancies, and relatively fewer numbers of working-age people. There are alarmist views – both popular and serious – in circulation regarding what these changes might mean for business and economic performance. But the effects of population aging are not straightforward to predict. Population aging does raise some formidable and fundamentally new challenges, but they are not insurmountable. These changes also bring some new opportunities, because people have longer, healthier lives, resulting in extended working years, and different capacities and needs. The key is adaptation on all levels: individual, organizational, and societal. This article explores some potentially useful responses from government and business to the challenges posed by aging.population, aging, longevity, fertility

Pensions and labor turnover in Japan

In the study, an unusually rich dataset containing linked information on pension plans and labor markets was assembled to investigate the effects of wages and pension benefits on job turnover in Japanese manufacturing. Both the description of how wage and pension compensation are structured in Japan, and the research findings on the role pensions play in inducing strong job attachment among Japanese workers, should be of interest to policy makers, personnel managers, and labor economists studying issues of aging and retirement

Interspecies Differences in Food Sources for the Tropical Callichirid Shrimp \u3ci\u3eNeocallichirus\u3c/i\u3e spp. on San Salvador Island, Bahamas

At least 4 species of callichirid shrimp coexist in the shallow marine settings of San Salvador Island, an isolated, small platform of the all-carbonates Bahama Archipelago, implying that interspecific competition or trophic niche segregation occurs between these shrimp species. Carbon and nitrogen stable isotope analyses were conducted on soft tissues of 3 callichirid species, Neocallichirus cacahuate, N. grandimana, and N. maryae, to determine the food sources for each species. These analyses revealed that the isotopic trophic niches for these 3 species do not overlap. The most important food source for all 3 species was manatee grass Syringodium filiforme. The second most important food source for N. cacahuate and N. grandimana was drifting seaweed Sargassum sp., whereas that for N. maryae was turtle grass Thalassia testudium. These food-source adaptations likely contribute to the high species diversity of callichirid shrimp in tropical settings such as those found on San Salvador Island

Burrow Morphology of the Bahamian Land Crab \u3ci\u3eGecarcinus lateralis\u3c/i\u3e

Abstract from 2010 Workshop on Crustacean Bioturbation — Fossil and Recent held in Lepe, Spain. Editors: Jordi M. deGibert, Fernando Muñiz, Eduardo Mayoral, Zain Belaústegu

Burrow Morphology of the Land Crab Gecarcinus lateralis and the Ghost Crab Ocypode quadrata on San Salvador Island, The Bahamas: Comparisons and Palaeoenvironmental Implications

Burrow morphologies of the land crab Gecarcinus lateralis and the ghost crab Ocypode quadrata were investigated on East Beach, San Salvador Island, The Bahamas, with the goals of critical comparison of their morphologies and of clarifying and advancing their palaeoenvironmental usefulness. In comparing land crab burrows to those of the ghost crab, the former are simpler but more variable in overall shape. G. lateralis burrows have a more compressed form in the transverse section of the burrow shaft and possess lower (more horizontal) shaft inclination than those of O. quadrata. In the late Holocene backshore and dune deposits on San Salvador, two types of fossil burrows were observed. On the basis of the morphologic differences documented herein between modern burrows of land and ghost crab species, one fossil burrow form can be interpreted as having been produced by G. lateralis and the other (trace fossil Psilonichnus upsilon) produced by O. quadrata. Because the modern burrows of these crabs are different not only in shape but also in their environmental preference, the occurrence of trace fossils comparable to burrows of the land crab and ghost crab (P. upsilon) could be used as indicators of vegetated coastal dunes (land crab burrows) and beach backshore (near sea level; ghost crab burrows) palaeoenvironments. Las morfologías de las madrigueras del cangrejo rojo terrestre, Gecarcinus lateralis, y del cangrejo fantasma, Ocypode quadrata, se investigaron en la playa del Este (East Beach) de la isla de San Salvador (Bahamas) con el objetivo tanto de diferenciarlas defi nitivamente entre sí como de clarifi car y avanzar en la comprensión de su signifi cado paleoambiental. Al comparar las madrigueras de los cangrejos terrestres con las de los cangrejos fantasma, se observa que las primeras son más simples pero más variables en morfología. La sección transversal de las madrigueras de G. lateralis presenta una forma más comprimida que la observable en las madrigueras de O. quadrata, así como su inclinación, más horizontal en la parte inferior. En los depósitos dunares y de backshore del Holoceno tardío de San Salvador se han diferenciado dos tipos de madrigueras fósiles. A partir de las diferencias morfológicas observadas entre las madrigueras de las especies actuales de los cangrejos fantasma y terrestres podría interpretarse que uno de estos tipos de madrigueras fósiles fue producido por G. lateralis y el otro (Psilonichnus upsilon) por O. quadrata. Puesto que actualmente las madrigueras de estas especies de cangrejos terrestres (G. lateralis) y fantasma (O. quadrata), además de ser diferentes en morfología, también son propias de ambientes determinados, la existencia de icnofósiles comparables a sus madrigueras se puede usar como indicador de paleoambientes asociados a dunas costeras con vegetación (las del cangrejo terrestre) y de depósitos de backshore (cercano al nivel del mar; las del cangrejo fantasma)

Modern and Fossil Callianassid Burrows of the Bahamas: Comparisons and Implications for Paleoenvironmental Analysis

Reprinted from: Bosiljka Glumac & Michael Savarese (eds.), Proceedings of the 16th Symposium on the Geology of the Bahamas and Other Carbonate Regions:San Salvador, Gerace Research Cente