Internal migration and development transitions in South East Asia     

Pryor RJ 《Population geography : a journal of the Association of Population Geographers of India》1981,3(1-2):57-68

The relationships between migration trends and changes in socioeconomic structures, settlement systems, and regional development programs in developing countries are analyzed. Current and possible future trends in urbanization in Southeast Asia are summarized, with a focus on the effects of migration. The impact of internal migration on spatial distibution in Thailand, Malaysia, Indonesia, and the Philippines is examined. The need for taking cultural traditions into consideration in the formulation of population policies and programs is emphasized.  相似文献   

Conflicts between explicit and implicit population distribution policies in Asian development plans     

Fuchs RJ 《Population geography : a journal of the Association of Population Geographers of India》1981,3(1-2):41-56

Conflicts between explicit and implicit population distribution policies in Asian development plans are examined. Various implicit policies and their possible consequences for spatial distribution are discussed. The development plans of China and Thailand are analyzed with particular attention to population distribution goals, the principal explicit policies aimed at promoting those goals, and the implicit policies that might conflict with explicit goals.  相似文献   

Simulated infrared emission spectra of highly excited polyatomic molecules: a detailed model of the PAH-UIR hypothesis     

Cook DJ  Saykally RJ 《The Astrophysical journal》1998,(2):793-802

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Hypoxia and benthic community recovery in Korean coastal waters   总被引：1，自引：0，他引：1  

Lim HS  Diaz RJ  Hong JS  Schaffner LC 《Marine pollution bulletin》2006,52(11):1517-1526

Low dissolved oxygen (hypoxia and/or anoxia) has become a major cause of change to the benthic component of ecosystems around the world. We present the response of a benthic community to hypoxia in organically enriched environments in Korean coastal waters. Disturbances due to low dissolved oxygen (DO), and organic enrichment altered community dynamics, result in defaunation during summer hypoxia with delayed recolonization occurring in winter. As DO decreased, the number of taxa, their abundance and biomass of macrofauna dropped significantly at inner bay stations in Chinhae Bay and Youngsan River estuarine bay affected by hypoxia. With the return of normoxic conditions in Chinhae Bay, recolonization was initiated by opportunistic species, with a 1-4months lag. The polychaetes, Sigambra tentaculata, Mesochaetopterus sp., and Lumbrineris longifolia, were most persistent under hypoxia. The first recolonizers were the polychaetes Paraprionospio pinnata, S. tantaculata, Glycinde gurjanovae and Nectoneanthes multignatha and the bivalve Theora fragilis. The second group of colonizers included the polychaetes Capitella capitata, Mesochaetopterus sp. and L. longifolia, and the bivalve Raetellops pulchella. Hypoxic and near anoxic conditions resulted in mass mortality in Chinhae Bay and Youngsan River estuarine bay, but communities did partially recover after return to normoxic conditions despite delayed recolonization.  相似文献   

An assessment of chemical pollution from the MSC Napoli     

Readman JW  Guitart C  Frickers T  Law RJ 《Marine pollution bulletin》2007,54(5):501-503

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Biological and ecological factors related to trace element levels in harbour porpoises (Phocoena phocoena) from European waters     

Lahaye V  Bustamante P  Law RJ  Learmonth JA  Santos MB  Boon JP  Rogan E  Dabin W  Addink MJ  López A  Zuur AF  Pierce GJ  Caurant F 《Marine environmental research》2007,64(3):247-266

Selected trace elements (Cd, Cu, Hg, Se, Zn) were measured in the kidneys and the liver of 104 harbour porpoises (Phocoena phocoena) stranded along the coasts of France, Galicia (Spain), Ireland, Scotland (UK), and the Netherlands. Generally, relatively low concentrations of toxic elements were encountered in the tissues of European porpoises, except for two individuals, which displayed high hepatic Hg concentrations. Also, elevated Cd levels obtained in Scottish porpoises could be related to their feeding preferences and this result suggests an increase of the proportion of cephalopods in their diet with latitude. Moreover, significant geographical differences were seen in hepatic Zn concentrations; the elevated Zn concentrations displayed by porpoises from the Netherlands may relate their poor health status. Variation in metal concentrations within porpoises from the North Sea is likely to reflect a long-term segregation between animals from northern (Scotland) and southern areas (the Netherlands), making trace elements powerful ecological tracers.  相似文献   

Suburbanization and sustainability in metropolitan Moscow     

Mason RJ  Nigmatullina L 《Geographical review》2011,101(3):316-333

Although Soviet-era urban-growth controls produced relatively sustainable metropolitan development patterns, low-density suburban sprawl has accelerated markedly in modern Russia. Distinctive features of Moscow's development history are its greenbelt, which dates from 1935 and is becoming increasingly fragmented, proliferation of satellite cities at the urban fringe, conversion of seasonal dachas into full-time residences, the very exclusive Rublevo Uspenskoe Highway development, and today's crippling traffic congestion. The recent economic crisis has slowed development and actually increased the supply of “economy-class” single-family homes, for which there is much pent-up desire but insufficient credit availability to meet the demand. A renewed commitment to sustainability's triple bottom line—environmental quality, equity, and economic prosperity—will require greater government transparency and fairness, stronger planning controls, and an expanded public transportation system.  相似文献   

Microbial survival in space shuttle crash     

McLean RJ  Welsh AK  Casasanto VA 《Icarus》2006,181(1):323-325

A slow growing, heat resistant bacterium, identified by 16S rRNA gene sequencing as Microbispora sp., was recovered from the wreckage of the ill-fated space shuttle Columbia (STS-107). As this organism survived disintegration of the space craft, heat of reentry, and impact, it supports the possibility of a natural mechanism for the interplanetary spread of life by meteorites.  相似文献   

Distribution of contaminants in biota and sediments in the Musquash Estuary, Atlantic Canada, marine protected area site initiative and contaminant exclusion zone     

Chou CL  Paon LA  Moffatt JD  Buzeta MI  Fenton D  Rutherford RJ 《Marine pollution bulletin》2004,48(9-10):884-893

The Musquash Estuary, one of the last ecologically intact estuaries in New Brunswick, has been designated an area of interest for a marine protected area (MPA) under the Oceans Act. The area has been assessed for contaminant background levels as required for establishing MPA environmental quality. American lobster (Homarus americanus), blue mussel (Mytilus edulis) and sediments were collected for assessing contaminant levels and distribution in the harbour. Levels of contaminants from the indicator species and the abiotic component have shown: (1) two extremes of high and low Cu and Ag in lobster from the area; and (2) lower metal levels in inner Musquash Harbour sediments and mussels than in those from the harbour mouth. These suggest that deposition of contaminants into the Musquash MPA site was due to transport of contaminants by coastal currents from upstream coastal industrial activities. This reverse trend with higher contaminant levels in the biotic and abiotic components in the outer harbour than in the inner harbour differs from a contaminated harbour and suggests that a contaminant exclusion zone should be considered for controlling contamination from nearby coastal and estuarine industrial sites to protect the sensitive habitats within the marine protected area.  相似文献   

Impact of erosion and accretion on the distribution of enterococci in beach sands     

Gast RJ  Gorrell L  Raubenheimer B  Elgar S 《Continental Shelf Research》2011,31(14):1457-1461

Bacterial pathogens in coastal sediments may pose a health risk to users of beaches. Although recent work shows that beach sands harbor both indicator bacteria and potential pathogens, it is neither known how deep within beach sands the organisms may persist nor if they may be exposed during natural physical processes. In this study, sand cores of approximately 100 cm depth were collected at three sites across the beach face in Kitty Hawk, North Carolina, before, during, and after large waves from an offshore hurricane. The presence of DNA from the fecal indicator bacterium Enterococci was detected in subsamples at different depths within the cores by PCR amplification. Erosion and accretion of beach sand at the three sites were also determined for each sampling day. The results indicate that ocean beach sands with persisting enterococci signals could be exposed and redistributed when wind, waves, and currents cause beach erosion or accretion.  相似文献