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901.
Dr. J. A. M. A. Tan J. S. H. Tay L. I. Lin S. K. Y. Kham J. N. Chia T. M. Chin Norkamar Bt. Adb. Aziz H. B. Wong 《黑龙江环境通报》1994,14(11):1077-1082
β-Thalassaemia major patients have chronic anaemia and since 3–4 per cent of Singaporeans carry the β-gene, prenatal diagnosis is essential. We evaluated the amplification refractory mutation system (ARMS) technique as a routine test for prenatal diagnosis of β-major. Six mutations along the β-gene were studied—41–42 (-TCTT), IVSII #654 (C-T), 17β (A-T), – 28 TATA (A-G), IVSI #5 (G-C), and IVSI #1 (G-T). Our results indicate that prenatal diagnosis using these mutations can be offered to 90 per cent (35/39) of our Chinese couples and 54·6 per cent (12/22) of our Malay couples at risk. Confirmation of ARMS results was carried out using allele-specific oligonucleotide hybridization. Prenatal diagnosis using ARMS was successfully carried out in nine cases which included a set of triplets and twins. The triplets were diagnosed with the β-trait carrying the 41–42 mutation. The couple with twins possessed the #654 mutation and one twin was diagnosed with the β-trait and the other with #654 homozygosity. Genomic sequencing of the undefined mutations in the Chinese couples revealed rarer mutations at − 29 and an ATG-AGG base substitution at the initiation codon for translation. In the Malay couples, genomic sequencing detected mutations at codon 15 (TGG-TAG) and codon 26 (GAG-AAG). We conclude that ARMS with its direct detection of amplified products by gel electrophoresis provides an accurate, rapid, and simpler method for our β-thalassaemia prenatal diagnosis programme in Singapore. 相似文献
902.
Soy cake* was homogenized and filtered through an 80 mesh net to produce small, detritus-like particles. The effect of soy-cake particles, an artificial detritus, on the survival and growth of Penaeus japonicus Bate zoea was then tested. The soy cake was considered to be effective for survival and growth of the zoea. The best survival rate, 85.9%, was obtained in a tank receiving soy cake in quantities of 0.16 mg/zoea/day. An experiment was also performed to compare three kinds of food: particles of soy cake alone, diatoms (Chaetoceros rigidus) alone, and a half and half mixture of the two. The best growth, 2.49 mm, and the highest survival rate, 79.1%, were found in larvae fed the mixture of soy-cake particles and diatoms. The results thus seem to demonstrate that particles of soy cake could be usefully applied to the mass-culture of the penaeid prawn. 相似文献
903.
904.
Dr Patrick H. Armstrong 《The Environmentalist》1994,14(3):215-231
Summary A historic analysis of human-initiated influences on the Falkland Islands ecologies is presented. Ecosystems were extensively altered by the destruction of seal and penguin communities in the late eighteenth and nineteenth centuries; and by the introduction of domesticated animals and exotic plants, the proliferation of fires, and the hunting to extinction, or near extinction, of certain animals. The harsh Falklands climate has permitted only limited recovery from some of these ravages. No island ecosystems, however remote, are spared the effects of economic and political changes influencing the rest of the world.He has published a previous article on island ecologies inThe Environmentalist (1992). 相似文献
905.
Summary Biosphere reserves are protected areas of representative environments internationally recognised for their value for conservation and for their ability to provide the scientific knowledge, skills and human values to support sustainable development. Biosphere reserves — as a part of the UNESCO programme Man and the Biosphere (MAB) — make up a world-wide network sharing research information on ecosystem conservation, management and development. They include strictly protected core-areas — representative examples of natural or minimally disturbed ecosystems. Core areas are surrounded by buffer zones in which research, environmental education and training and recreation can take place. Buffer zones are, in turn, surrounded by transition areas, large open areas where the aim is to ensure rational development of the natural resources of the region. At present, twelve biosphere reserves are designated in Germany, covering in all an area of 11,589 km2. The role of biosphere reserves to support sustainable development in Germany and Europe is discussed.Karl-Heinz Erdmann is a geographer and Deputy Secretary General at the Secretariat of the German National Committee for the UNESCO Programme on Man and Biosphere (MAB), Federal Agency for Nature Conservation. He is also a Committee Member of the Society for Man and Environment (GMU). 相似文献
906.
Dr A. Y. Sangodoyin 《The Environmentalist》1993,13(4):255-261
Summary There has been a paucity of reliable data on the contribution of Nigerian women in rural development, particularly with respect to water projects. From a detailed survey of many rural settings, and an evaluation of the availability of sources of water and the existing methods of purification, it was discovered that rural women, especially those of younger years, were heavily involved in water collection. The time and energy involved in water fetching and purification could sometimes be so high that other economic and domestic activities were adversely affected. The participation of Nigerian women in water development and quality improvement is hindered by problems, such as their standard of education, low level of awareness of the benefits of a good water source, lack of funds and organisational constraints. In general, this study has recognised an urgent need for more imaginative, better funded and better co-ordinated water development projects for the enhancement of the quality of life, especially for women in rural settings. 相似文献
907.
Summary The basic tools of engineering, energy and material balances and rate expressions, provide a pathway to apply the Natural Laws of Hazardous Waste for proper waste management. Overall, one must focus on nature's limits, which are discussed, using open minded engineering practices for proper waste management. By expansion of balance concepts beyond end-of-pipe and integrating concepts beyond basic life-cycles, as discussed in this paper, the true impact ofwaste management practices may be established. These cradle-to-grave balances are connected to nature's limits via results of recent work by others on risk assessment. The combination of approaches for evaluating concentration limits of chemicals in the environment allows the facility for an engineering solution for proper waste management. The method is presented by making example comparisons of choices of technology for recycling, storage, and site remediation. 相似文献
908.
Dr Martin Akhurst B. Sc. 《The Environmentalist》1995,15(1):58-64
Summary Noting a paucity of sociological research investigating countryside recreation from an experiential perspective, this paper reports on a study aimed at exploring the meaning of such terms as the countryside, rural and natural as they are understood by the person-in-the-street. A typification of countryside recreation is constructed which suggests that individuals have an essentially simple understanding of the environment in this context which centres upon an urban-rural dichotomy. The urban setting is generally associated with negative experiences while the rural setting is regarded more positively. These attitudes suggest that the countryside represents a form of refuge from many stresses commonly associated with modern, urban lifestyles. An implication of this conclusion is that attempts to educate people into recognizing the links between their everyday behaviour and the degradation of the countryside will be met with considerable resistance since this would entail them in reconstruing their relationship with the environment. 相似文献
909.
910.