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941.
942.
M. Cougnon P. De FrenneL. Bommelé B. De CauwerK. Verheyen D. Reheul 《Agriculture, ecosystems & environment》2011,144(1):159-166
This study tested the hypothesis that raising canal water levels with 30 cm beyond the growing season in intensively managed lowland grassland (2.4-3.7 m above sea level) in Belgium decreases the agronomic value of pastures The study ran 3 years before and 3 years after the water elevation. Using five pairs of plots inside and outside the wetted perimeter, it was not possible to demonstrate significant impacts of the elevated water level on dry matter yield, forage quality, botanical composition, and penetration resistance of the top soil layer of the grassland. In an ex situ lysimeter experiment, simulating the effect of a water level in canals up to 50 cm beneath the surface of the pastures indicated a significant decrease of the penetration resistance of the top soil layer.Results are discussed and confronted with the difficulties of field research addressing the elevation of water levels. 相似文献
943.
“绿色贸易堡垒”是国际贸易中非关税贸易堡垒重要的组成部分,它从保护环境的目的出发,在国际贸易中发挥着越来越重要的作用。文章通过对天津市现实状况的研究,提出克服绿色贸易堡垒,为天津市经济在入世后获得“绿色通行证”的对策建议。 相似文献
944.
本文对攀枝花市的环保产业及其构成进行了分析,提出了该市环保产业的基本思路和具体目标,并针对该市环保产业存在的问题提出了发展环保产业的对策。 相似文献
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947.
Hélène Duval Laurence Michel-Calemard Marie Gonzales Philippe Loget Claire Beneteau Annie Buenerd Madeleine Joubert Marielee Denis-Musquer Alix Clemenson Anne-Laure Chesnais Sophie Blesson Isabelle De Pinieux Anne-Lise Delezoide Gheorghe Bonyhay Christine Bellanné-Chantelot Laurence Heidet Florence Dupré Sophie Collardeau-Frachon 《黑龙江环境通报》2016,36(8):744-751
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Jan Deprest Marie-Paule Emonds Jute Richter Philip DeKoninck Tim Van Mieghem Dominique Van Schoubroeck Roland Devlieger Luc De Catte Liesbeth Lewi 《黑龙江环境通报》2011,31(7):661-666
With the increased use of invasive fetal procedures, the number of women facing post-procedure membrane rupture is increasing. Here we review the use of platelets and fresh frozen plasma for sealing iatrogenic fetal membrane defects by describing the mechanisms of action of the amniopatch procedure as well as published experience. In cases of iatrogenic preterm pre-labour rupture of the membranes, amniopatch effectively seals the fetal membranes in over two-thirds of cases. There is a risk of 16% of in utero fetal death, which may occur at varying intervals from the procedure and often for unknown reasons. Amniopatch has also been used as a treatment of chorionic membrane separation. In summary, current experience suggests that in cases of early onset but persistent amniotic fluid leakage following an invasive fetal procedure, amniopatch is an option. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
950.
The social environment of many species includes synchronous maturation of siblings in family groups, followed by limited dispersal
of adults from their natal site. Under these conditions, females may experience high encounter rates with same-age siblings
during mate searching, increasing their risk of inbreeding. If inbreeding depression occurs, mating with a sibling is often
considered maladaptive; however, in some contexts, the inclusive fitness benefits of inbreeding may outweigh the costs, favoring
females that tolerate some level of inbreeding depression. We evaluated mating patterns in the treehopper Umbonia crassicornis, a semelparous species in which females encounter same-age siblings during mate searching. A female U. crassicornis that mates with a brother suffers from inbreeding depression. We used a free-choice mating design that offered females simultaneous
mating opportunities with three groups of males: siblings, same-age nonsiblings, and older nonsiblings. These groups represent
the types of males typically encountered by females during mate searching. Our goal was to assess whether mating patterns
were influenced by inbreeding avoidance by evaluating two hypotheses: kin discrimination and age-based mating (older males
cannot be siblings in this species). There was no difference in the proportions of females mating with siblings vs nonsiblings,
suggesting an absence of kin discrimination. However, females mated with a greater proportion of older vs younger males. Given
that females do not avoid siblings as mates despite a cost to inbreeding, our results provide a possible example of inbreeding
tolerance. We also discuss some factors that may have contributed to the mating advantage of older males. 相似文献