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81.
The surface water samples were collected in river Dahe and its tributaries, which flow into severely eutrophic lake Dianchi, Yunnan Province, China, in order to elucidate factors controlling water quality fluctuations. The temporal and spatial distribution of water quality tendency was observed. The water quality of each river is dependent on the hydrology effect such water gate and circulating irrigation system. We must consider the hydrology effect to accurately understand water quality variations of river in this study field. In river without highly circulating irrigation system or water gate effect, the downstream nitrate nitrogen (NO3-N) concentration increase occurred in area dominated by open field cultivation, whereas the NO3-N concentration was constant or decreased in area dominated by greenhouse land use. This result suggests that greenhouse covers the soil from precipitation, and nitrate load of greenhouse could be less than that of open field cultivation while the rainfall event. In the upper reaches of river, where is dominated by open field cultivation, there were no sharp increase dissolved molybdate reactive phosphorus and total phosphorus concentration, but P load was accumulated in the lower reaches of river, whose predominant land use is greenhouse. Although the P sources is unclear in this study, greenhouse area may have potential of P loads due to its high P content in greenhouse soil. Considering hydrology effect is necessary to determine what the major factor is influencing the water quality variation, especially in area with highly complicated irrigation system in this studying site.  相似文献   
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Parasites are ubiquitous in natural systems and ecosystem-level effects should be proportional to the amount of biomass or energy flow altered by the parasites. Here we quantified the extent to which a manipulative parasite altered the flow of energy through a forest-stream ecosystem. In a Japanese headwater stream, camel crickets and grasshoppers (Orthoptera) were 20 times more likely to enter a stream if infected by a nematomorph parasite (Gordionus spp.), corroborating evidence that nematomorphs manipulate their hosts to seek water where the parasites emerge as free-living adults. Endangered Japanese trout (Salvelinus leucomaenis japonicus) readily ate these infected orthopterans, which due to their abundance, accounted for 60% of the annual energy intake of the trout population. Trout grew fastest in the fall, when nematomorphs were driving energy-rich orthopterans into the stream. When infected orthopterans were available, trout did not eat benthic invertebrates in proportion to their abundance, leading to the potential for cascading, indirect effects through the forest-stream ecosystem. These results provide the first quantitative evidence that a manipulative parasite can dramatically alter the flow of energy through and across ecosystems.  相似文献   
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Health care waste is considered a major public health hazard. The objective of this study was to assess health care waste management (HCWM) practices currently employed at health care centers (HCCs) in the West Bank – Palestinian Territory. Survey data on solid health care waste (SHCW) were analyzed for generated quantities, collection, separation, treatment, transportation, and final disposal. Estimated 4720.7 m3 (288.1 tons) of SHCW are generated monthly by the HCCs in the West Bank. This study concluded that: (i) current HCWM practices do not meet HCWM standards recommended by the World Health Organization (WHO) or adapted by developed countries, and (ii) immediate attention should be directed towards improvement of HCWM facilities and development of effective legislation. To improve the HCWM in the West Bank, a national policy should be implemented, comprising a comprehensive plan of action and providing environmentally sound and reliable technological measures.  相似文献   
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S. Sato 《Marine Biology》1994,118(4):663-672
The relationship between shell growth and sexual maturation was studied in the venerid bivalve Phacosoma japonicum (Reeve) based on specimens from six populations around the Japanese coast in 1991 and 1992. A distinct latitudinal variation in the patterns of shell growth and gonad development was detected. Speciments from northern populations are characterized by slower rates of gonad development, later offset of interval of shell growth, and larger shell size at a given age than those from southern populations, excluding the population from the Ariake Bay, Kyushu. These data indicate the presence of a tradeoff between reproductive effort and continued growth in this species. However, in all populations bivalves attain sexual maturity before ending shell growth. First sexual maturity occurs at a shell size of about 60% of the maximum asymptotic shell height. Maximum reproductive effort appears to start when the energy available for shell growth (i.e., the yearly growth rate of shell weight) attains a maximum. These relationships between shell growth and sexual maturation were also confirmed in some other bivalve species.  相似文献   
88.
A new Triassic archosaurian from China shows a number of aquatic specializations, of which the most striking is the extreme lateral compression of the long tail. Others that may also reflect aquatic adaptations include platelike scapula and coracoid, elongate neck with extremely long and slender ribs, and reduction of osteoderms. In contrast, its pelvic girdle and hind limb have no aquatic modifications. Anatomic features, taphonomy, and local geological data suggest that it may have lived in a coastal–island environment. This lifestyle, convergent with some Jurassic marine crocodyliforms that lived at least 40 million years later and the saltwater species of extant Crocodylus, contradicts with the prevailing view that Triassic archosaurians were restricted to nonmarine ecosystems. Its mosaic anatomy represents a previously unknown ecomorph within primitive archosaurians.Electronic Supplementary Material  Supplementary material is available for this article at  相似文献   
89.
A new type of waste gasification and smelting system using oxygen blowing based on high-temperature metallurgy, was developed by Sumitomo Metals, Japan. This system can steadily gasify and melt not only municipal waste, but also plastic waste and polyvinyl chloride (PVC) waste by using a top-blow oxygen lance together with sideways-blow oxygen lances. As a result of gasification in the high-temperature reducing atmosphere and rapid gas cooling, dioxin-free, high-calorie purified gas was produced. Ash components in the wastes were smelted in a high-temperature reducing atmosphere, and high-quality slag free of heavy metals was produced. Most of the chlorine in the wastes was converted into hydrogen chloride in the off gas. The hydrogen chloride can be recovered as hydrochloric acid or chlorine, which are recyclable to PVC manufacturing.  相似文献   
90.
Four automatic weather stations (AWS) were installed on the slopes and foot areas of the Tianshan and Kunlun Mountains along a longitude of 80 degrees east: (1) Taglak 2400 m a.s.l., (2) Aksu 1000 m, (3) Kartash 2800 m, and (4) Qira 1700 m. These two slopes face the Taklimakan Desert. Tagliak lies on the southern slope of Tianshan, and Kartash on the northern slope of Kunlun. The meteorological characteristics of the mountainous regions were investigated using surface data obtained during an intensive observation period (IOP) in spring 2002. It was found that visibility on the slopes decreases in the daytime, and there is no relationship between visibility and wind speed in the mountainous areas. Two snow layers containing dust particles were observed in the snow cover in Taglak during the IOP in spring 2003. These results suggest that a warm air parcel containing aeolian dust climbs over the slopes of the mountainous areas, and dust particles in the mountainous areas are transported from the foot areas.  相似文献   
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