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131.
开展生态系统生产总值(GEP)核算是推进生态文明制度建设的必要措施,也是将生态效益纳入经济社会发展评价体系的重要举措。本研究以福州市为研究对象,通过构建具有“山、海、城”特色的生态系统价值核算体系,对2015和2018年福州市GEP进行核算,从时空变化角度对福州市GEP进行对比。结果表明: 2015、2018年福州市GEP分别为9205.92、10472.42亿元,人均GEP分别为13.02、14.39万元,生态产品供给服务价值分别为941.81、1102.61亿元,生态调节服务价值分别为6364.20、5988.51亿元,生态文化服务价值分别为1899.91、3381.3亿元。与2015年相比,2018年福州市GEP增加1266.50亿元,增幅为13.8%,主要得益于生态产品供给服务价值和生态文化服务价值的增加。然而,生态调节服务价值减少375.69亿元,降幅为5.9%,主要源于气候调节、水流动调节和水质净化服务价值的减少。福州率先探索建立一套具有山、海、城特色的核算体系,可以为福建省其他城市及我国其他地区的核算工作提供“福州样板”,同时助推建立生态价值实现的长效机制。  相似文献   
132.
We describe the development of 13 variable microsatellites developed to investigate population structure and dispersal in the sea urchin Centrostephanus rodgersii. This species is the dominant grazing herbivore in southeast Australian coastal waters and has the ability to modify benthic community structure. The microsatellites we identified showed a range of allele numbers (4–21) and expected heterozygosity (0.32–0.91) in two sampled populations. Contrary to previous findings in free‐spawning marine invertebrates, genotype proportions in neither population deviated significantly from Hardy–Weinberg expectations.  相似文献   
133.
Spermiating male European sea bass Dicentrarchus labrax were treated with gonadotropin-releasing hormone agonists (GnRHa), either a GnRHa injection (IN; 25 μg kg−1 body mass) or one of three types of controlled-release GnRHa-delivery systems: fast release implants (EVAc; 1OO μg kg−1), slow release implants (EVSL; lOO μg kg−1) and slow release microspheres (MC; 50 μg kg−1). Luteinizing hormone (LH) release was highly stimulated by all GnRHa treatments, with elevated plasma levels lasting for 2 days in injected fish (IN) and 2, 4 and 6 weeks in controlled-release-treated fish (EVAc, MC and EVSL, respectively), correlating with a 1, 3, 5 and 5 week period of stimulation of milt production, respectively. Plasma levels of the androgens testosterone (T) and 11-ketotestosterone (11-KT), were not significantly affected by the GnRHa treatments. Plasma T was high at early spermiation and declined sharply near the end of this period. Plasma 11-KT levels declined continuously throughout the experiment. Levels of 17,20 β -dihydroxy-4-pregnen-3-one (17,20 β -P), a proposed maturation-inducing steroid (MIS) in European sea bass, fluctuated around 0.2–1 ng ml−1 and were not greatly affected by the treatments. These results indicated a close correlation between sustained stimulation of LH release, achieved by GnRHa-delivery systems, and long-term enhancement of milt production. They also show an absence of changes in the common sex steroids, associated with elevated LH and enhanced spermiation.  相似文献   
134.
The surface structures of the tongues of Dissostichus mawsoni, Trematomus bemacchii, f. borchgrevinki (Nototheniidae), Stemoptyx diaphana (Sternoptychidae), Diretmus sp. (Diretmidae), Cataetyx memorabilis (Ophidiidae), Photoblepharon palpebratus (Anomalopidae), Carapus mourlani (Carapidae) and Salmo gairdneri (Salmonidae) were investigated with the scanning electron microscope. The aim of the study was to test the theory that the degree to which gustatory receptors are developed morphologically in different species of fishes is related to the environment, and in particular to the variey of food present in the latter. It was found that in the two mesopelagic species, S. diaphana and Diretmus sp., taste receptors were poorly developed, but in the benthic deep-water fish C. memorabilii , which lives off South West Africa in a biologically rich environment, well-developed taste receptors occurred in large numbers. The three Antarctic species studied had similar tongue surface structures with rather well developed papillae of a moderate density. Photoblepharon palpebratus , in spite of its small tongue, possessed a large number of taste buds on elevated ridges; Carapus mourlani , however, had only very few obvious receptors and is thought to be a poor taster. Undoubtedly the highest degree of taste receptor development is found in the freshwater trout Salmo gairdneri. The results support the hypothesis that taste receptor development and the variety of food types preseni in a fish's environment are correlated.  相似文献   
135.
In spite of their potential importance in evolution, there is little information about Hox genes in animal groups that are related to ancestors of deuterostome. It has been reported that only two Hox genes (Hbox1 and Hbox7) are expressed significantly in sea urchin embryos. Expression of Hbox1 protein is restricted to the aboral ectoderm, and Hbox7 expression is restricted to oral ectoderm, endoderm and secondary mesenchyme cells in sea urchin embryos after the gastrula stage. With the aim of gaining insight into the role of Hbox1 and Hbox7 in sea urchin development, Hbox1 and Hbox7 overexpression experiments were performed. Overexpression of Hbox1 repressed the development of oral ectoderm, endoderm and mesenchyme cells. On the contrary, overexpression of Hbox7 repressed the development of aboral ectoderm and primary mesenchyme cells. The data suggest that Hbox1 and Hbox7 are expressed in distinct non-overlapping territories, and overexpression of either one inhibits territory-specific gene expression in the domain of the other. It is proposed that an important function of both Hbox1 and Hbox7 genes is to maintain specific territorial gene expression by each one, in its domain of expression, while repressing the expression of the other in this same domain.  相似文献   
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137.
The molecular order of brain and liver membranes isolated from deep sea and continental shelf fish species have been estimated and compared using the fluorescence polarization technique in order to determine whether life in a high pressure habitat is associated with an adjustment of membrane order. Fish were trawled at depths between 200 m and 4000 m, liver and brain membranes were fractionated, and fluorescence polarization was measured at 4°C and ambient pressure. Polarization of the brain myelin fraction provided a statistically significant regression with depth of capture (P<0.001) with a slope of ?0.004 km?1. This change in polarization with depth was sufficient to offset approximately half of the pressure-induced increase in polarization and thus represents the first structural evidence of homeoviscous adaptation to pressure. Polarization of the brain synaptic and liver mitochondrial fraction was not significantly related to depth. This may be due, at least in part, to a high individual variability of polarization compared to laboratory-acclimated freshwater fish.  相似文献   
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140.
Recent expeditions have revealed high levels of biodiversity in the tropical deep‐sea, yet little is known about the age or origin of this biodiversity, and large‐scale molecular studies are still few in number. In this study, we had access to the largest number of solariellid gastropods ever collected for molecular studies, including many rare and unusual taxa. We used a Bayesian chronogram of these deep‐sea gastropods (1) to test the hypothesis that deep‐water communities arose onshore, (2) to determine whether Antarctica acted as a source of diversity for deep‐water communities elsewhere and (3) to determine how factors like global climate change have affected evolution on the continental slope. We show that although fossil data suggest that solariellid gastropods likely arose in a shallow, tropical environment, interpretation of the molecular data is equivocal with respect to the origin of the group. On the other hand, the molecular data clearly show that Antarctic species sampled represent a recent invasion, rather than a relictual ancestral lineage. We also show that an abrupt period of global warming during the Palaeocene Eocene Thermal Maximum (PETM) leaves no molecular record of change in diversification rate in solariellids and that the group radiated before the PETM. Conversely, there is a substantial, although not significant increase in the rate of diversification of a major clade approximately 33.7 Mya, coinciding with a period of global cooling at the Eocene–Oligocene transition. Increased nutrients made available by contemporaneous changes to erosion, ocean circulation, tectonic events and upwelling may explain increased diversification, suggesting that food availability may have been a factor limiting exploitation of deep‐sea habitats. Tectonic events that shaped diversification in reef‐associated taxa and deep‐water squat lobsters in central Indo‐West Pacific were also probably important in the evolution of solariellids during the Oligo‐Miocene.  相似文献   
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