广西北部湾经济区农业非均衡发展比较研究

在广西自治区北部湾经济区基本情况的基础上,对农业经济、农业生产、农民生活等农业发展总体情况进行了分析;利用广西自治区、南宁市、防城港市、钦州市、北海市面板数据,借鉴国内学者的研究成果和经济非均衡增长理论,从该区域第一产业人均增加值、粮经比、农产品产出、人均农产品占有量4个方面对该区域存在的非均衡发展现象进行比较分析。基于经济、产业、条件等基础层面分析非均衡发展现象的成因,并提出了强化北部湾农业产业分工与协同、强化北部湾农村改革试验的集成研究、强化北部湾农业产业升级与转型发展的对策建议。     

广西北部湾方格星虫氨基酸组成与营养价值评价

[目的]测定广西北部湾方格星虫的氨基酸,进行营养价值分析评价,为进一步开发利用提供理论依据。[方法]用全自动氨基酸分析仪测定广西北部湾方格星虫的氨基酸含量,利用荧光法测定色氨酸含量,并根据FAO/WHO的氨基酸评分标准模式进行氨基酸营养价值评价。[结果]共测定18种氨基酸,总量为(73.93±2.80)%;鲜味氨基酸为(30.60±1.05)%,占氨基酸总量的41.39%;必需氨基酸为(26.22±1.01)%,占氨基酸总量的35.47%;非必需氨基酸含量为(39.12±1.43)%,必需氨基酸与非必需氨基酸的比例为67.05%,符合FAO/WHO标准。[结论]广西北部湾方格星虫营养价值较高、品质优良,具有较高保健价值和药用价值,值得进一步开发。     

Eutrophication and Recreational Fishing on the Finnish Coast of the Gulf of Finland: A Mail Survey

The Gulf of Finland is one of the most eutrophic areas in the Baltic Sea and is also the main fishing area for more than 150 000 recreational fishermen in Finland. The findings of a mail survey showed that the most important species for the recreational fishery is perch, Perca fluviatilis L. There is no clear evidence that eutrophication has had a harmful effect on the stocks of perch and other species considered important. Heavy fouling of gear, particularly gill nets, is the most acute problem caused by eutrophication to the local recreational fishery. The rapid fouling of passive gear was experienced by 67–86% of all fishermen in the three study areas. A general deterioration in water quality was perceived because only 2–14% of fishermen rated the water quality as excellent. However, a minority of recreational fishermen seem to have adapted or grown accustomed to the deterioration in water quality. Even in the two most eutrophic study areas, 23–31% of recreational fishermen considered that an improvement in local water quality would not benefit their own fishing in any way.     

Trends in coho marine survival in relation to the regime concept

There was a synchronous and significant decrease in marine survival of coho salmon in the Strait of Georgia, Puget Sound, and off the coast from California to Washington after 1989. This large-scale, synchronous change indicates that trends in coho marine survivals were linked over the southern area of their distribution in the north-east Pacific, and that these linkages were associated with a common event. Indicators of large-scale climate change (the Aleutian Low Pressure Index) and of recent regional climate change (the April flows from the Fraser River) also changed abruptly about the same time. The synchrony of trends in marine survival of aggregates of coho stocks from three distinct marine areas and trends in climate indices implies that climate/ocean changes can have profound impacts on the population dynamics of coho salmon. The trend towards low marine survival may persist as long as the trends in the climate indicators do not change.     

基于Goldstein模型的农村人力资源培训需求研究——以广西北部湾为例

采用Goldstein模型,从组织、任务、人员3个方面对广西北部湾农村人力资源培训需求进行研究,结果表明,培训内容应包括激发参加培训的积极性、提高文化素质、提高科技素质、培养经营能力。     

基于SPOT-VEGETATION的北部湾经济区植被变化特征

以2000-2011年423景SPOT-VEGETATION逐旬NDVI数据为基础,采用MVC、标准差、线性趋势分析和HURST指数等数理统计方法对北部湾经济区植被覆被时空变化特征及未来趋势进行定量分析。结果表明,2000-2011年北部湾经济区NDVI值呈波动上升趋势,快于广西区年NDVI平均增长速率。NDVI均值存在着明显的分段特征,且转折点出现在2006年,2006年以前研究区植被覆盖呈现下降趋势,2006年以后呈现显著增加趋势。NDVI均值在空间上呈现出西北和西南植被覆被低、东南植被覆被高的态势,NDVI均值纬向分布呈现出北高南低,经向分布线性倾向率比较小,仅为0.5952/1N°。NDVI标准差的变幅较大,表现为波动小主要分布在NDVI均值的两个极端,波动较小与波动较大并存,波动较大分布比较零散的空间格局。NDVI的Hurst指数反持续(10.03%)持续性序列(89.97%),说明经济区植被的变化趋势处于持续性改善的趋势。     

我国北部湾部分海产品中副溶血弧菌的基因分型研究

利用RAPD技术对北部湾分离的24株Vp进行基因分型。结果显示：RAPD可以分离出7~11条不同的条带,大小0.45~1.50 kb。聚类分析结果表明在相似度为0.84时,RAPD分辨力指数为0.931。采用通过POPGENE 32软件对比了24株Vp的各种遗传参数,结果表明：RAPD的Shannon信息指数、有效等位基因数、Nei基因多样性分别为0.5616、1.6816和0.3823。表明RAPD能较好地研究Vp的分子遗传特征,适合于区分不同来源的Vp菌株。     

Transnational Ecosystem Services: The Potential of Habitat Conservation for Waterfowl Through Recreational Hunting Activities

This article explores transnational ecosystem services in North America, provided by winter habitat for waterfowl in western Mexico coastal lagoons, and the hunting industry supported by these birds in the United States. This article shows that the number of waterfowl harvested in the United States is related to the abundance of waterfowl wintering in Mexico. On average, this flow of ecosystem services annually yields US$ 4.68 million in hunting stamp sales in the western United States. A demand curve, fitted to duck hunting licenses as a function of stamp price and previous-year waterfowl harvest, estimated US$3–6 million in consumer surplus produced in addition to governmental stamp sales revenue. This strongly suggests that waterfowl wintering habitat in western Mexico is economically valuable to U.S. hunters. Because hunters may benefit substantially from these habitats they may be willing to pay for conservation efforts in western Mexico that can result in transnational benefits received in the United States.     

Evaluating alternative rodenticides for island conservation: roof rat eradication from the San Jorge Islands, Mexico

Introduced commensal rats (Rattus spp.) are a major contributor to the extinction and endangerment of island plants and animals. The use of the toxin brodifacoum to completely eradicate rats from islands is a powerful conservation tool. However, brodifacoum is toxic to animals other than rats and on some islands its use may not be feasible without prohibitively expensive mitigation. As part of a regional conservation program, we experimentally tested brodifacoum and two less toxic rodenticides, diphacinone and cholecalciferol, in eradicating Rattus rattus from three small islands in the northern Gulf of California, Mexico. All three rodenticides were successful in eradicating rats, suggesting that the less toxic diphacinone and cholecalciferol may be useful alternatives to brodifacoum for some island eradication programs. However, the choice of rodenticide must be balanced between efficacy and the risks to non-target species. Applied field research is needed on less toxic rodenticides, as well as improving palatability of baits. This may prove invaluable in preventing extinctions and in restoring larger and more diverse island ecosystems.     

Genetic differentiation in hatchery strains and wild white shrimp Penaeus (Litopenaeus) vannamei (Boone, 1931) from northwest Mexico

Ten enzymatic systems were analyzed to determine allozyme genetic differentiation among three hatchery strains (A, B and C) of white shrimp, Penaeus (Litopenaeus) vannamei, commonly used in shrimp farming in northwest Mexico. A wild population from northern Sinaloa was used as a reference. Fifteen loci were detected, nine of which were polymorphic (ACP-1*, ACP-2*, AKP-2*, EST-2*, EST-3*, EST-4*, EST-5*, LAP*, and LDH*). Polymorphism of A, B and C were 53, 53, and 40%. The mean observed heterozygosity per locus was 0.071, 0.093, and 0.050 without any significant difference among them or with respect to the wild population (0.056). In all samples observed heteroxygosity was smaller than expected. The mean number of alleles per locus was 1.8 in A and 1.87 in both B and C. Strain A was the only sample without rare alleles. Only EST-3* and LAP* of strain A were in Hardy-Weinberg equilibrium; the other loci were in disequilibrium in all samples. High inbreeding values and heterozygote deficiencies were detected in all samples. Distribution of allelic frequencies was heterogeneous among the samples (G-test), involving all polymorphic loci and suggesting a genetic differentiation. According to Fst, a moderate genetic differentiation (7.4%) was detected among the samples. Greater differences were between strains A and C. Based on genetic distance, the samples were grouped into two pairs, B-C and A-wild. Strain A is a young strain related to the wild sample, whereas strains B and C have a different geographic origin than the wild sample.