Applicability of <Emphasis Type="Italic">Perinereis aibuhitensis</Emphasis> Grube for fish waste removal from fish cages in Sanggou Bay,P. R. China

The present study investigated the applicability of integrated polychaete-fish culture for fish waste removal to offset negative impact induced by organic benthic enrichment. A field study demonstrated that deposition rate was significantly higher underneath the fish farm than that in control area. The material settling under the farm was characterized by a high amount of fish feces (45%) and uneaten feed (27%). Both feeding rate (FR) and apparent digestibility rate (ADR) increased with decreasing body weight, as was indicated by significantly a higher rate observed for the groups containing smaller individuals in a lab study. The nutrient in fresh deposited material (De) was higher than that in sediments collected under the farm (Se), resulting in lower feces production but higher apparent digestibility rate for the De group as feeding rate was similar. Consequently, higher nutrient removal efficiency was observed in the De group. A mass balance approach indicated that approximately 400–500 individuals m?2 is required for removing all waste materials deposited underneath the fish farm, whereas abundance can be lower (about 300–350 individuals m^?2) when only the fish waste needs to be removed. The results showed that a significant amount of waste had been accumulated in the fish cages in Sanggou Bay. The integration of fish with P. aibuhitensis seems promising for preventing organic pollution in the sediment and therefore is an effective strategy for mitigating negative effect of fish farms. Thus such integration can become a new IMTA (integrated multi-trophic aquaculture) model in Sanggou Bay.     

地理信息电子政务应用中若干问题的思考

本文分析地理信息技术在电子政务中应用模式的现状和发展趋势,地理信息技术在电子政务应用模式从松耦合向紧耦合发展。同时就地理信息技术在电子政务应用中亟待解决的若干技术和体制问题进行讨论,提出解决上述问题可能的方案和途径。     

Recreational value estimation of suburban leisure agriculture: a case study of the Qianjiangyue agritourism farm

As a form of economic and community development, agritourism has a strong and widespread appeal to all tourists. To explore the situation and value of agritourism in China, the Qianjiangyue agritourism farm located between Fuzhou City and Yongtai County was chosen to evaluate recreational values. The data was obtained from tourists and farm samples in Qianjiangyue agritourism farm by questionnaires. Two basic models including the zonal travel cost method (ZTCM) and the individual travel cost method (ITCM) were applied for data analysis. The recreational value estimation results obtained from ITCM and ZTCM showed that the total consumer surplus (CS) of the Qianjiangyue agritourism farm in 2011 was estimated at 54,533,300 CNY (8,894,682 US$) which was equal to a CS per tourist of 3029.63 CNY (494.15 US$), and the annual recreational value of agricultural landscapes per hm² was 361,078 CNY (58,893.82 US$). The average annual recreational value of agritourism farmland was 15.7 times of that from traditional farming, and 6 times of present land business income. This paper will be helpful for exploring and utilizing appropriate environmental resources in China.     

Structure and dynamics of fisheries in Nigeria

The changes that have taken place in Nigerian fisheries are reviewed. Artisanal fishery has continued to dominate the fisheries,contributing over 85% of total fish production. The inland water and coastal seas are fully exploited and the increase in fishery production is not likely. Aquaculture potentials remain untapped as much as deep-sea fisheries. The combined potential of the fisheries resources-freshwater,marine and aquaculture can meet over 90% of the nation's demand for fish. Opportunities for invest-ments,therefore,exist in the various subsectors,especially in the areas of storage,processing and preservation for the capture fishery and fish seed multiplication for aquaculture.     

采煤塌陷地复垦项目PPP融资模式应用研究

探索PPP融资的运作模式与双方合作机制,促进PPP融资模式在采煤塌陷地复垦项目中的应用。研究基于风险-收益均衡原则,从私人资本与政府的风险偏好特点出发,建立了项目总成本最小的最优风险分担模型;在风险分担系数已知的情况下,建立了Shapley值模型对双方收益进行合理分配。结果表明:私人投资主体的综合风险系数略大,双方基本上均担风险;私人投资主体承担绝大部分的项目资金投入,所获收益略大于政府。因此引入PPP模式进行采煤塌陷地复垦,对于政府而言,可以解决资金压力,分散不擅长的项目与金融、市场风险;对于私人投资主体而言,可以避免过多的政策与不确定性风险,获得较高的投资收益。该研究为采煤塌陷地复垦项目PPP融资谈判提供了理论依据,对加快塌陷区复垦进程具有非常重要的现实意义。     

How can saline and hypersaline lakes contribute to aquaculture development? A review

A considerable part of the world's population is currently experiencing a severe scarcity of freshwater and nutrition. Inland aquaculture has the fastest growth in fresh waters, and this contributes to the eutrophication of freshwater bodies. The increase in freshwater aquaculture impacts on the increasing demand for fresh water. A way to overcome this is to develop aquaculture in saline lakes. This article discusses how saline and hypersaline lakes may contribute to overcome this problem and gives a list of fish and shrimp species that can be cultivated in saline lakes. Successful development of aquaculture depends on a healthy cultured stock of commercial fish and shrimps. A sustainable healthy stock of fish and shrimps can be only maintained using live food for the cultured fish larvae, fry and fingerlings. As well as Artemia spp. there are many other crustacean species with the potential for growing in hypersaline waters. At least 26 copepod species around the world can live at a salinity above 100 g/L with 12 species at a salinity higher than 200 g/L, and these all have excellent nutritional value. There is a high potential to use eukaryotic organisms of diff erent taxa in saline/hypersaline aquaculture for food, agri-aquaculture, diff erent industries and as food supplements.     

Large-Scale Screening of Growth-Related Variants in Chinese Tongue Sole(Cynoglossus semilaevis)

Growth is the most valuable economic trait for improving aquaculture fish species, since fast growth can reduce labor cost and make more economic benefits. However, the knowledge about how many and which genes are related to the growth of Chinese tongue sole is limited. High-throughput sequencing screening of variants is a fast, economical and accurate assay to identify genes related to growth in crops, livestock and other aquaculture products. In the present study, genome-wide resequencing of 30 female Chinese tongue sole individuals from large and small groups to screen growth trait-related variations(SNPs, InDels) was carried out. In total, 6545735 SNPs and 1016745 InDels were detected, while 31 genes related to growth traits were identified. Their functions were mainly involved in muscle architecture, post-embryonic development, neurosensory development and hormone regulation. Furthermore, 18 of the 31 genes related to growth trait are located on W chromosome, indicating that W chromosome plays an important role in regulating the body size of female tongue soles. The markers and genes identified in our study can be applied to selective breeding of tongue sole and thus will promote the aquaculture industry and increase economic efficiency.     

电子政务与数字中国地理空间基础框架

在对电子政务和数字中国地理空间基础框架的基本概念、内容和体系结构进行深入描述之后,指出电子政务非常需要数字中国地理空间基础框架的支撑,集中体现为：数字中国地理空间基础框架是电子政务的空间定位平台,可以为电子政务提供空间辅助决策支持,并可为电子政务提供清晰易读的可视化工具;与此同时,电子政务为数字中国地理空间基础框架的建设提供了新的应用空间和发展机遇。     

A Comparative Study of Fish Assemblages Near Aquaculture,Artificial and Natural Habitats

Habitat plays a critical role in regulating fish community structure. Using the data collected from a monthly trammel net survey in Ma’an archipelago off the east coast of China, we evaluated impacts of five different habitats(artificial reefs, mussel farms, cage aquaculture, rocky reefs and soft bottom) on fish assemblages. This study suggests that artificial reefs(AR) have significantly higher species richness, abundance and diversity than mussel farms(MF) or soft bottom(SB) habitats during most seasons, and that fish taxa in the AR habitats are similar to those in the rocky reef(RR) habitats. Two different fish assemblage patterns were revealed in the study area using non-metric multidimensional scaling ordination: an assemblage dominated by reef fishes(especially by Scorpaenidae species) in AR, RR and cage aquaculture(CA) habitats and an assemblage dominated by Sciaenidae species in MF and SB habitats. We suggest that reef fishes play a key role in differentiating fish community structures in the study area. Although few differences in fish abundance and diversity were found between the CA and SB habitats, a more diverse age structure was observed in the CA habitats. A much more complex fish assemblage and enhanced population of local species were established as a result of the presence of both floating and fixed artificial structures, probably through improved survival rates.     

城市GIS应用与发展之案例分析与对策

研究城市GIS持续发展问题,对于城市决策者具有很高的参考价值,对于GIS参与者也具有借鉴意义。以实现城市GIS持续发展为目标,调查了中、美、英11个都市区的GIS案例,围绕GIS组织管理、战略规划、数据开发等方面,分析这些城市的GIS应用与推广经验。在讨论城市GIS持续发展的基础上,中国城市GIS应用突破的关键在于:成立完善的组织体系;重视中长期的战略事项;落实项目管理;优先开发基础地理数据;注重GIS的投资效益。     

基于SOA云服务的济宁市电子政务服务平台研究

基于政务网的政府各部门横向与纵向信息共享及业务协同的需求十分迫切,传统的单向共享模式的应用瓶颈日益突出,结合济宁市政务信息平台建设的实际环境及需求,设计了基于SOA云服务的政府部门间信息资源共享及在线业务协同平台的框架,实现了政府各部门之间数据有序交换和资源共享,建立了数据建设规范和业务协同机制,极大地提升了政务办公自动化水平。     

N-策略精益生产排队模型分析与设计

研究了精益生产环境下，生产线可能发生故障的单服务台N-策略M／M／I随机服务服务系统，利用概率母函数给出了模型的各项稳态指标；设计了预期费用函数，利用函数求解出当预期费用最少时的最优N-策略；并对模型进行了数值模拟。     

Numerical Simulation of Mechanical Characteristics of a Metal Net for Deep-Sea Aquaculture

The investigation on hydrodynamic characteristics of a cage is important for its application in the deep-sea aquaculture in our country. With finite element method, the beam element is used to simulate a three-dimensional metal chain net, and the connector element is introduced as the interaction between metal net lines. A mechanical model for the metal net is constructed to simulate the hydrodynamic characteristics of a metal net subjected to fluid current forces. The static simulation results show that the relative errors of the displacements are 2.13%, 4.19%, 6.64%, and 11.35% compared with static concentrated load tests under concentrated forces of 20, 40, 60, and 80 N, respectively. Both the transient hydrodynamic deformations and drag forces of the netting structures under different current velocities are obtained by solving the hydrodynamic equation of the netting structure. The average relative error of the current forces obtained by numerical simulations shows an 8.13% deviation from the drag tests of the metal nets in the tank under five current velocities. The effectiveness and precision of the simulation approach are verified by static and dynamic tests. The proposed simulation approach will provide a good foundation for the further investigation of the hydrodynamic characteristics of deep-sea aquaculture metal cages and the parameter design for the safety of such cage systems.     

Assessment of nitrogen maintenance requirement in juvenile Black Porgy <Emphasis Type="Italic">Acanthopagrus schlegeli</Emphasis>

Nitrogen balance method and nitrogen-free diet were used in this study to determine nitrogen maintenance requirement (NM) and nitrogen maintenance requirement per unit metabolism body weight (NM′) of black porgy Acanthopagrus schlegeli. Fish with body weight (BW) of 50, 80, 120, 160 and 200 g were fed by the diets containing three graded levels of crude protein (380, 420 and 460 g/kg). The results from nitrogen balance experiment showed that the amount of nitrogen deposition varied from 0.15 to 0.31 mg/g BW per day, accounting for 12.2% to 21.1% of nitrogen intake. The amount of fecal nitrogen excretion varied from 0.21 to 0.32 mg/g BW per day, accounting for 16.3% to 21.6% of nitrogen intake. The endogenous nitrogen excretion, a main part of nitrogen consumption varied from 0.79 to 0.97 mg/g BW per day, accounting for 63.3 % to 68.0% of nitrogen intake. Positive correlation was found between NM and body weight, while a negative correlation was found between NM of unit body weight and the growth duration. No significant differences (p>0.05) were found in NM′ among different growth stages. The average of NM′ was 0.485 7mg/g per day. The results from nitrogen-free diet experiment showed that a negative correlation between NM and feed intake of nitrogen-free diet. NM increased with the decrease of feed intake of fish. The average of NM was 0.482 9 mg/g BW per day that was close to 0.483 8 mg/g BW obtained from fish with 120 g BW in nitrogen balance experiment. The nitrogen balance method is recommended to be a better method for determining NM in consideration of fish stress and result stability. This study also provides a calculated result of the protein content in diets, which is necessary for maintaining fish body protein at different growth stages. The calculation was based on the amount of nitrogen required for maintaining body protein per kg BW. Supported by Scientific Research Project Grant (No.2004C100059) from the city government of Ningbo, China.     

Comparative study of the nutritional composition and toxic elements of farmed and wild Chanodichthys mongolicus

Information of the difference in quality between farmed and wild fish is central to better ensuring fish products produced in aquaculture meet regulatory and consumer requirements.Proximate composition,amino acid and fatty acid profiles,and toxic elements contents of farmed and wild Chanodichthys mongolicus were established and compared.Significantly higher crude protein content while lower moisture content in farmed fish compared to wild fish were observed(P0.05).The percentages of total amino acids(TAA),total essential amino acids(TEAA),total non-essential amino acids(TNEAA)and total delicious amino acids(TDAA) in farmed fish were all significantly higher than those in the wild equivalent(PO.05).Compared to the FAO/WHO recommended reference values,the ratios of TEAA/TAA(39.84%-40.33%) were comparable to 40%and TEAA/TNEAA(66.22%-67.60%) were above 60%.Fatty acid profiles in both fanned and wild C.mongolicus were dominated by monounsaturated fatty acid(MUFA),with farmed fish contained much more MUFA content compared to wild counterpart(P0.05).Notably,wild fish exhibited significantly higher levels of total polyunsaturated fatty acid(PUFA) including eicosapentaenoic acid(EPA) and docosahexaenoic acid(DHA) than farmed fish(P0.05).The EPA(C_(20:5n3))and linoleic acid(C_(18:2n6)) were the predominant PUFA in wild and fanned C.mongolicus,respectively.Moreover,farmed fish displayed an overall lower toxic element levels(As,Cd,Pb and Hg) in comparison with wild fish,and both were far lower than the established limit standard.In conclusion,our results suggest that the nutritional quality of farmed C.mongolicus was inferior to their wild counterpart with respect to fatty acids nutrition,and therefore further studies should focus on the improving C.mongolicus diet in order to enhance the overall nutritional composition.     

Integrated biological control of water hyacinths, Eichhornia crassipes by a novel combination of grass carp, Ctenopharyngodon idella (Valenciennes, 1844), and the weevil, Neochetina spp.

The efficacy of grass carp Ctenopharyngodon idella (Cyprinidae) and weevils Neochetina spp. (Curculionidae) to control the aquatic weed, water hyacinth, is investigated in a square net cage (happas) setting at a farm in Cuddalore District, South India. This novel combination of insects and fish is found to be superior to individual treatments for controlling the weed growth within 110 d. The biomass of the weed, number of plants, percentage of flowered plants and chlorophyll contents were studied. The weed ...     

“互联网+政府服务”初探

简要论述了利用互联网加强服务型政府建设的重要性和必要性,概略分析了我国利用互联网加强服务型政府建设的现状,指出"互联网+政府服务",实质上是利用互联网技术,依托互联网平台,把互联网思维融入政府服务,让政府决策更科学、服务更聪明,让企业和群众办事更方便、更快捷、更有效率,建设的重点是政务新媒体和电子政务平台,关键是政府服务创新,难点是互联网思维的养成,核心在于落实"以人民为中心"的发展思想,提出"互联网+政府服务",要着力加强政务新媒体建设、做强网上官方舆论场、大力发展电子政务、丰富政府大数据资源、创新智能化公共服务、推进网络问政等6个方面的建设,强化做好顶层设计、加强法规制度和基础设施建设、深化行政管理体制改革、增强政府服务意识、推进示范引领、激发群众自觉参与、强化网络监督等7个方面的支撑。     

Experimental Study on the Hydrodynamic Characteristics of a Submersible Fish Cage at Various Depths in Waves

Submersible fish cages can be submerged under the water to mitigate the negative effects that arise from severe sea conditions and improve the growing environment for the farmed fish. Thus they are increasingly applied in offshore aquaculture. To ensure both safety and economic efficiency of submersible fish cages, it is important to determine the optimum submergence depth. In this study, a series of physical model experiments were conducted to investigate the hydrodynamic performance of a submersible fish cage at various submergence depths(1/6, 1/4, 1/3, and 1/2 of the water depth as well as the floating condition for reference) with a model scale of 1:20. The results of the physical model experiment for the different depths were compared to analyze the effects of submergence depths on the mooring line tension and the movement of the floating collar. The results showed that the mooring line tension and the floating collar movement significantly attenuated with increasing submergence depth. However, the attenuation tendency became stable when the fish cage reached a certain depth. According to the results, 1/3 of water depth was determined as the optimal submergence depth of the fish cages. Deeper submergence depths showed no significant advantage from a perspective of the hydrodynamic characteristics of the fish cage. The determination of the optimum submergence depth is beneficial for the structural design and operation safety of submersible net cages.     

Determinants of public goods investment in rural communities in mountainous areas of Sichuan Province,China

This study aims to investigate two important issues： what are the determinants of public goods investment and what is the government＇s investment behavior in mountainous areas. The impacts of natural conditions, target, and demand elements on public goods investment are analyzed with statistical method, and the determinants of public goods investment in the areas are obtained by using population-weighted and stepwise regression models with Eviews6.0 software with survey data in 2008 and calculated data based on GIS of 20 typical villages in mountainous regions in Sichuan, China. The results showed： （1） natural conditions are the important determinants of public investment. Mountainous villages with steep slope have relatively high levels of investment; （2） concentration of population and the educational levels of the village leaders also have important impacts on public goods investment; （3） the government is more concerned with public investment resources particularly in areas characterized by fragile ecological environment and poor agricultural output. These results suggest that the current investment strategy helps to reduce disparities in regional development.