云南淡水渔业种业发展战略的若干思考

目的 为了充分发挥云南的资源和气候优势,服务国家战略,服务地方社会经济发展,服务东南亚,乃至全球渔业发展,提出将云南建设成为我国淡水渔业种业南繁基地的战略构想。方法 文章通过实地考察和历史文献资料研究,综合分析论述云南建设成为我国淡水渔业种业南繁基地的可行性、必要性和和重要意义,在气候条件、种质资源、淡水资源等必备条件方面论证云南建设成为我国淡水渔业种业南繁基地不可替代的优势。结果 （1）云南具有优越的气候条件、丰富的特有渔业种质资源、充足的淡水资源,为建设我国淡水渔业种业南繁基地奠定了重要的物质基础。（2）滇南地区日照充足,积温高,鱼类可周年生长,提早性成熟,缩短繁育周期,提高良种选育效率,为快出良种、出优质良种提供了极佳的气候条件。（3）云南是我国淡水渔业种质资源的宝库,分布鱼类达629种,占全国淡水鱼类种类总数的39.93%,居全国各省市之首,其中有大量性状优良的特有物种,开发利用潜力巨大。（4）云南淡水资源蕴藏量丰富,人均水资源占有量是全国人均的2.3倍,澜沧江下游的西双版纳州人均水资源占有量是全国的4.6倍,但水资源开发利用率仅5.7%,发展渔业是符合大食物观,提高水资源利用率的有效途径。因此,云南完全具备建设成为我国淡水渔业种业南繁基地的必备条件。结论 云南建设成为我国省淡水渔业种业南繁基地是可行和必要的,将服务于云南经济和社会发展,改善优化云南农业产业结构,培育出的优良品种将支撑我国淡水养殖业升级换代,满足消费者对优质水产品的需求,还可以澜沧江—湄公河下游的中南半岛国家为依托,向全世界提供中国新品种和中国技术方案。     

A High Road to Sustainability? Wildflower Harvesting,Ethical Trade and Social Upgrading in South Africa's Western Cape

This paper evaluates the outcomes from an ambitious wildflower harvesting programme in South Africa's Western Cape, which has sought to achieve positive outcomes in terms of socio‐economic development and biodiversity conservation. Indigenous wildflowers, harvested according to conservation principles, are processed into ‘Cape Flora’ bouquets and sold into international and domestic markets. The principal supply chain provides an example of ethical trade due to the explicit environmental and social standards that are required at local sites of production. The incorporation of such standards represents an attempt to engender economic and social upgrading within the value chain. In this sense, the programme is consistent with dominant policy discourses, which suggest that exploiting potentially profitable niches within international trade flows represents a ‘high road’ to economic growth and transformation. The paper focuses upon the job creation and social impacts of the programme in the context of efforts to overcome South Africa's deeply entrenched socio‐economic disparities and high poverty levels. Despite impressive growth in production and exports during the global financial crisis, there have been mixed outcomes in terms of benefits to stakeholders at the upstream end of the supply chain. The paper concludes by considering the extent to which local initiatives operating under the framework of ethical trade possess the potential to facilitate effective social and economic upgrading.     

Financial Analysis of Scale Versus Lump Sum Timber Sale Payment Methods

A financial analysis of two methods commonly used by public land management agencies to collect payment for stumpage sold was carried out using data from the St. Louis County Minerals and Land Department (SLCMLD) in northern Minnesota. The two payment methods evaluated were scale (also called pay-as-cut and consumer scale) where the buyer only pays for timber harvested and lump sum (also called sold-on-appraised-volume or SOAV) where a buyer pays for the entire tract’s estimated volume, regardless of the amount of timber actually harvested. The analysis found no significant difference in gross timber sale revenue collected by the SLCMLD under the two payment methods Scaled timber sales incurred an additional $323 in administrative costs per timber sale compared to lump sum timber sales. This increase in administrative costs represents less than 1% of the timber value contained in the average SLCMLD timber sale. Differences in the standards agencies use to estimate merchantable stand volume of a timber sale and the administrative time spent processing timber sales can impact the financial costs associated with each timber payment method.     

芝麻在储藏过程中的生物化学变化

在储藏过程中,芝麻所含3大营养物质皆发生了相应的生物化学变化。其中,糖类物质在有氧呼吸和无氧呼吸作用下被氧化分解生成二氧化碳、水及乙醇等;脂类物质经酶促反应和非酶促反应作用生成过氧化物、甘油和游离脂肪酸等;蛋白质类物质在不同的酸度条件下分解生成氨基酸或进一步分解生成氨、硫化氢和胺类物质等。     

非公有制林木采伐管理改革成效、问题及政策建议——基于河北省三个平原试点县的调查

通过访谈和问卷调查,考察和分析了河北省3个平原试点县非公有制林木采伐管理改革的实施效果,总结了改革过程中存在的问题,提出了五项建议:编制森林经营方案,协调国土资源管理部门统一土地类型,按林业资源的实际安排采伐限额指标,完善落实生态效益补偿基金,取消育林基金。     

Applied Policy Analysis of the Rice Marketing Subsector of Guinea-Bissau

Simple analytical techniques are used to diagnose and demonstrate problems observed in the rice marketing subsector of Guinea-Bissau. The problems are typical of those encountered by liberalizing economics. The recommendations favor policies that enhance competition.     

电子标签辅助拣选研究

详细介绍了电子标签辅助拣选的两种主要拣货方式:摘取式拣货和播种式拣选,并简要介绍了电子标签辅助拣选的特点及适用的行业。     

Regime switching in stochastic models of commodity prices: An application to an optimal tree harvesting problem

This paper investigates whether a regime switching model of stochastic lumber prices is better for the analysis of optimal harvesting problems in forestry than a more traditional single regime model. Prices of lumber derivatives are used to calibrate a regime switching model, with each of two regimes characterized by a different mean reverting process. A single regime, mean reverting process is also calibrated. The value of a representative stand of trees and optimal harvesting prices are determined by specifying a Hamilton-Jacobi-Bellman Variational Inequality, which is solved for both pricing models using a implicit finite difference approach. The regime switching model is found to more closely match the behavior of futures prices than the single regime model. In addition, analysis of a tree harvesting problem indicates significant differences in terms of land value and optimal harvest thresholds between the regime switching and single regime models.     

Regulation and Evolution of Compliance in Common Pool Resources

The evolution of compliance with regulation and the evolution of a CPR stock are modeled jointly in a setup where replicator dynamics describing compliance with harvesting rules are combined with resource stock dynamics. This evolutionary approach suggests that in long‐run equilibrium, coexistence of both cooperative and non‐cooperative rules is possible under regulation. Stock effects on profits and a certain structure of auditing probabilities could imply the emergence of a limit cycle in areas of low stock levels, as an equilibrium outcome. It might be easier for the regulator to obtain full compliance under precommitment to fixed auditing probabilities.     

Developers and farmers intertwining interventions: the case of rainwater harvesting and food-for-work in Degua Temben,Tigray, Ethiopia

Understanding the objectives, strategies and actions of the different actors that play a role in the implementation of rural development programmes is a key to explaining the latter's success and sustainability. Based on in-depth anthropological fieldwork and from an actor perspective this paper shows how the Rainwater Harvesting Pond Programme (RHPP) and the public work component of the Productive Safety Net Programme (PSNP) work out in practice in one district of the Tigray region in Ethiopia. Developers and farmers turn the two essentially unrelated rural development programmes into practically intertwined interventions, which leads to an undesirable set of outcomes. The RHPP's participants, who are conceived of as willing to improve, are favoured above other candidates for employment in the PSNP, which farmers compete for. Developers' and farmers' moves and countermoves result in targeting errors in the PSNP and in farmers massively constructing rainwater harvesting ponds, the large majority of which fail because farmers do not aspire to make them succeed, but merely see them as a stepping stone to employment in the PSNP. In addition both groups' perception of each other is affected. Our observations challenge prevailing interpretations of the effects of development interventions on Tigrayan people's livelihoods.