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排序方式: 共有10000条查询结果,搜索用时 140 毫秒
991.
Fenna A. R. Jansen Sheila M. P. Everwijn Robert Scheepjens Theo Stijnen Cacha M. P. C. D. Peeters-Scholte Jan M. M. van Lith Monique C. Haak 《黑龙江环境通报》2016,36(7):601-613
Congenital heart defects (CHDs) are associated with neurodevelopmental (ND) delay. This study aims to assess evidence for impaired prenatal brain development, in fetuses with CHD. A systematical search was performed, and 34 studies evaluating the fetal brain [magnetic resonance imaging (MRI) or ultrasound] in isolated CHD were included (1990–2015). Data regarding cerebral abnormalities, head circumference growth and middle cerebral artery flow were extracted. Prenatal MRI was studied in ten articles (445 fetuses), resulting in a pooled prevalence of 18% (95%CI −6%; 42%) for combined structural and acquired cerebral abnormalities. Prenatal head circumference was studied in 13 articles (753 fetuses), resulting in a pooled z-score of −0.51 (95%CI −0.84; −0.18). Doppler was studied in 21 articles (1412 fetuses), resulting in a lower middle cerebral artery pulsatility index (z-score −0.70 95%CI −0.99; −0.41) in left-sided CHD only. We conclude that prenatal MRI and ultrasound demonstrate brain abnormalities, delay in head growth and brainsparing in subgroups of CHD. However, large MRI studies are scarce, and ultrasound data are biased towards severe and left-sided CHD. Long-term follow-up studies correlating prenatal findings with postnatal ND outcome are limited, and data are lacking to support counseling families regarding ND outcome based on prenatal findings suggestive of altered brain development. © 2016 John Wiley & Sons, Ltd. 相似文献
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Steven C. Latta 《Conservation biology》2000,14(1):132-139
Abstract: As research biologists move into conservation biology, especially in foreign countries, providing support for conservation planning efforts presents unique challenges. Published accounts of national, multidisciplinary planning efforts and priority setting for avian conservation are not common. I describe the process and results of a broad-based, grassroots-oriented avian conservation planning workshop held in the Dominican Republic in which we designed a coordinated strategy for avian conservation in the country. The planning process sought to (1) increase communication and cooperation among conservationists; (2) familiarize participants with resources pertinent to avian conservation; (3) encourage the transfer of information between researchers and managers; (4) promote the concepts of long-term avian monitoring, avian conservation plans, and species management plans; and (5) develop a common, multidisciplinary strategy to promote the conservation of birds in the Dominican Republic. The workshop highlighted group discussions among research biologists, managers, educators, and public policy specialists to assess avian conservation needs and priorities with respect to each discipline and has since galvanized a significant portion of the conservation community around several cooperative projects involving diverse segments of the community. Avian biologists can play a significant role in conservation efforts through a willingness to work with key players in diverse fields and to envision holistic, multidisciplinary approaches to conservation issues. 相似文献
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Y. Nassiri P. S. Rainbow C. Amiard-Triquet F. Rainglet B. D. Smith 《Marine Biology》2000,136(3):477-484
The talitrid amphipod crustacean Orchestia gammarellus (Pallas) was collected from metal-contaminated (Dulas Bay, Gironde) and control (Millport) sites in the UK and France. Irrespective
of site of origin, the amphipods showed the same physiological mechanism of trace-metal detoxification, involving the ventral
caeca. Copper was always present in lysosomal residual bodies in the ventral caeca. Following laboratory exposure to zinc
and cadmium, the lysosomes usually contained both copper and zinc but cadmium was not detectable. The lysosomal copper concentration
is positively correlated to that of sulphur, while the concentration of lysosomal zinc is related to that of phosphorus. Results
are interpreted in terms of the differential rates of turnover of metallothioneins chelating copper, zinc or cadmium.
Received: 9 February 1999 / Accepted: 2 December 1999 相似文献
996.
Abstract: Although economic analysis can be used to argue for preservation of species and habitats, many natural assets represent inferior investments in society's asset portfolio. We demonstrate this for the case of ancient temperate rainforests and minke whales ( Balaenoptera acutorostrata ). For both rainforests and whales, we determined their value for harvest and balanced this against society's valuation of the preserved stock. For the market and nonmarket data available, we then determined how much rainforest and how many minke whales global society should keep in its asset portfolio. Although ecologists increasingly attempt to justify preservation of biological assets on economic grounds, we argue that this might be a dangerous approach to take. Ultimately, it may be necessary to reexamine the ethical foundations for conservation of nature and biodiversity, including the economist's use of utilitarianism. We suggest that the safe minimum standard approach may prove useful in practice. 相似文献
997.
Rachèl V. van Schendel G. C. Page-Christiaens Lean Beulen Catia M. Bilardo Marjon A. de Boer Audrey B. C. Coumans Brigitte H. Faas Irene M. van Langen Klaske D. Lichtenbelt Merel C. van Maarle Merryn V. E. Macville Dick Oepkes Eva Pajkrt Lidewij Henneman for the Dutch NIPT Consortium 《黑龙江环境通报》2016,36(12):1091-1098
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