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1.
Loss of genetic diversity in Harpacticoida near offshore platforms   总被引:1,自引:0,他引:1  
Offshore oil and gas production platforms can be a source of chronic stress that could lead to sublethal impacts on resident benthic organisms. In June 1993 and January 1994, genetic diversity of Harpacticoida (Copepoda) living proximal to operating, offshore platforms in the Gulf of Mexico was estimated to test if platforms are associated with strong selective pressures. Because harpacticoids have short generation times and direct benthic development, they are suitable organisms for examining population responses. Genetic diversity was estimated by comparing restriction fragment length polymorphisms generated from mitochondrial DNA amplified by the polymerase chain reaction on individuals of five species (Cletodes sp., Enhydrosoma pericoense, Normanella sp., Robertsonia sp., and Tachidiella sp.). Populations living at Near regions (stations<50 m from a platform) had significantly less haplotype diversity than populations of the same species living at Far regions (stations>3 km from a platform). The levels of haplotype diversity exhibited by the Far populations were similar at three different platforms located hundreds of kilometers apart. The differences in haplotype diversity between Near and Far regions were the result of a higher proportion of dominant haplotypes, and a loss of less common haplotypes. Haplotypic diversity was inversely correlated with a multivariate measurement of levels of sediment contaminants. The pattern of haplotype diversity on the Gulf of Mexico continental shelf seems to consist of a uniform level of haplotype diversity, punctuated by islands of lower diversity around oil and gas platforms. The selective pressures that lead to a loss of genetic diversity may be the result of contaminants, other differences in the physico-chemical environment, or disturbance in general.  相似文献   
2.
This paper evaluates the adoption of standards as proof of and an incentive for sound environmental practice in business and industry. The paper outlines the origins of environmental management and the development of the first environmental management standard BS 7750. The background to quality management is outlined to provide a context for these developments. The paper then goes on to examine the likely success of BS 7750 in actually improving the environmental performance of organizations in the light of experience in the field of quality. Finally, alternative approaches are looked at as ways of achieving environmental improvement.  相似文献   
3.
This paper discusses the application of a novel polyacrylate-based ion-exchange material for the removal of Pb ions from water. Preliminary testing includes the establishment of the operating pH range, capacity information, and the effect of Ca2+ and anions in the matrix. Batch testing with powder indicates slightly different optimal operational conditions from those used for column testing. The ion-exchanger is excellent for removing Pb from aqueous solutions.  相似文献   
4.
There is a concern that mismanagement of medical waste in developing countries may be a significant risk factor for disease transmission. Quantitative estimation of medical waste generation is needed to estimate the potential risk and as a basis for any waste management plan. Dhaka City, the capital of Bangladesh, is an example of a major city in a developing country where there has been no rigorous estimation of medical waste generation based upon a thorough scientific study. These estimates were obtained by stringent weighing of waste in a carefully chosen, representative, sample of HCEs, including non-residential diagnostic centres. This study used a statistically designed sampling of waste generation in a broad range of Health Care Establishments (HCEs) to indicate that the amount of waste produced in Dhaka can be estimated to be 37 ± 5 ton per day. The proportion of this waste that would be classified as hazardous waste by World Health Organisation (WHO) guidelines was found to be approximately 21%. The amount of waste, and the proportion of hazardous waste, was found to vary significantly with the size and type of HCE.  相似文献   
5.
We report a case of maternal mosaic trisomy 21 ascertained at prenatal diagnosis as a result of maternal cell contamination of an amniotic fluid sample. A 34 year old female was referred for karyotyping because of a previous trisomy 21 pregnancy. Chromosome analysis of primary in situ cultures showed a karyotype of 47,XX, + 21[6]/46,XY[32]/46,XX[2]. Molecular testing demonstrated maternal cell contamination of the amniotic fluid sample and G-banded karyotyping of maternal blood showed that 3/200 cells had trisomy 21, consistent with the mother being a Down syndrome mosaic. A normal male baby with a 46,XY chromosome complement was delivered at 30 weeks. This case emphasises the need for close collaboration between cytogenetic and molecular genetics laboratories in resolving unusual cases of mosaicism. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
6.
Copper (Cu) is an essential element to humans; however, exposure to elevated concentrations through occupational hazard and/or environmental means may be detrimental. This paper provides results of a cross-sectional study aimed to determine the prevalence of copper sulphate (CuSO4) use in South African traditional medicine by traditional health practitioners (THPs) and details the use thereof. A total of 201 THPs were enrolled from two main municipal areas of KwaZulu-Natal (South Africa). Information on demographic characteristics of THPs, reasons for using or not using CuSO4 as well as administration methods and age groups of recipients were collected. Of the 201 THPs interviewed, 145 (72 %) use CuSO4 for healing purposes. The use of CuSO4 was strongly associated with gender (p = 0.009) where the proportion of CuSO4 users was higher for female than male THPs. CuSO4 was reportedly administered to individuals of all ages, including infants and children. The main routes of administration were enema (n = 110; 76 %), oral (n = 40; 28 %) and use in bath (n = 40; 28 %). The reasons cited for use are diverse and included skin rashes (n = 43; 30 %), aches, pains and swelling (n = 38; 28 %) as well as sexually transmitted diseases (n = 28; 19 %). This study identified a high prevalence of THPs using CuSO4 for healing purposes. These findings support the need to regulate South African traditional medicine to safeguard the user.  相似文献   
7.
The Science of Adaptation: A Framework for Assessment   总被引:2,自引:0,他引:2  
Mitigation and Adaptation Strategies for Global Change - This paper outlines what is meant by "adaptation" to climate change, and how it might be addressed in the IPCC Assessments. Two...  相似文献   
8.
Release of land for mineral extraction is often dependent on the quality of the restoration which can be achieved. It follows, therefore, that some means of judging the success of restoration is required, especially where restoration is an agricultural after use.In order to assess whether land has been well restored it is therefore necessary to know what the physical characteristics of the land were before mineral extraction took place, what changes are likely to have occurred to the land and soil as a result of mineral extraction, and lastly whether the physical characteristics of the land are as good as when the land was last used for agriculture. Most permissions however, were granted before there was a requirement to record pre-site conditions so it is impossible to know what the site was like when it was last used for agriculture. Furthermore, this paper will argue that land quality is only one factor which should be considered in assessing the quality of restored land, other factors for example, visual integration, farm management must also be taken into consideration. This paper will outline the existing evaluation procedures used by the Ministry of Agriculture, Fisheries & Food and Minerals Planners and suggest developing an evaluation procedure which considers various dimensions of restored land namely soil and land quality, visual integration and the management and productivity of restored land. This evaluation procedure has been applied to seventeen study sites of sand and gravel pits. The paper will indicate whether the evaluation procedure successfully classified these sites or not.  相似文献   
9.
Relationships among populations (southeast Atlantic and northern Gulf coast, USA) of a ubiquitous, estuarine, harpacticoid copepod (Microarthridion littorale Poppe) were estimated using sequence data from two loci: one mitochondrial [cytochrome b (Cyt b)] and one nuclear [first internal transcribed spacer of ribosomal DNA (ITS-1)]. Copepods were collected from seven estuaries in 1997/98. Allelic phylogenies based on both genes were generally concordant, and suggested that M. littorale populations are structured over large geographic scales (hundreds of kilometers). Three well-supported groups were found in both gene trees comprising clades of alleles sampled from South Carolina, Florida, and Louisiana. Alleles from the Savannah, Georgia sample formed a monophyletic group using the Cyt b data, but this clade was not distinguishable with comparable ITS-1 data. A single specimen from Louisiana was classified in different clades depending on the locus assayed. Received: 11 June 1998 / Accepted: 29 April 1999  相似文献   
10.
Biodiversity of sharks in the tropical Indo-Pacific is high, but species-specific information to assist sustainable resource exploitation is scarce. The null hypothesis of population genetic homogeneity was tested for scalloped hammerhead shark (Sphyrna lewini, n = 237) and the milk shark (Rhizoprionodon acutus, n = 207) from northern and eastern Australia, using nuclear (S. lewini, eight microsatellite loci; R. acutus, six loci) and mitochondrial gene markers (873 base pairs of NADH dehydrogenase subunit 4). We were unable to reject genetic homogeneity for S. lewini, which was as expected based on previous studies of this species. Less expected were similar results for R. acutus, which is more benthic and less vagile than S. lewini. These features are probably driving the genetic break found between Australian and central Indonesian R. acutus (F-statistics; mtDNA, 0.751–0.903, respectively; microsatellite loci, 0.038–0.047 respectively). Our results support the spatially homogeneous monitoring and management plan for shark species in Queensland, Australia.  相似文献   
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