Forced migration, processes of return and livelihood construction among pastoralists in northern Sudan

The Hawaweer, a nomadic, pastoralist group in northern Sudan, were seriously affected by the drought in the Sahel during the mid-1980s. Their experience illustrates the connection between internally displaced people, normal mobility, forced migration, dilemmas and opportunities of return and how new livelihoods can be successfully constructed based on traditional rights, strong local institutions and external resources. Some displaced Hawaweer got the chance to return to their homeland as new livelihood opportunities were established; others did not get this opportunity nor would they have returned if they had been given the chance. In both situations, the processes of displacement and return had an impact on the sense of belonging and identity.     

Testing hypotheses about management to enhance habitat for feeding birds in a freshwater wetland

The level of water was manipulated in a freshwater wetland, with the aim of enhancing abundances of benthic animals and, ultimately, improving habitat for feeding birds (Japanese Snipe, Gallinago hardwickii). We tested whether these actions had the predicted and desired effects on benthic animals, by contrasting changes in two managed locations to one control location which was left unmanipulated. The number of taxa and abundances of chironomids decreased strongly and significantly in the manipulated locations, while the abundance of oligochaetes appeared to vary in a seasonal manner. Temporal variability of the structure and composition of assemblages was also increased in manipulated locations. Such effects have previously been suggested to indicate stress in benthic assemblages. Therefore, in contrast to what was predicted, managerial actions made benthic fauna less abundant and thus, less suitable as habitat for feeding birds. Several general lessons can be learned from these results. (1) Effects of managerial actions like these are difficult to predict a priori and can only be reliably evaluated with an experimental framework. (2) Because abundances of animals vary naturally, evaluations of managerial actions must include appropriate spatial replication. (3) Sampling at hierarchical temporal scales is important, because abundances of animals may vary in an unpredictable manner at short temporal scales and because changes in temporal variability may be a symptom of stress. (4) Combined use of uni- and multivariate techniques provides a comprehensive set of tools to assess the effects of restoration and creation of new habitats. Finally, these results emphasise the need for clear predictions about desired outcomes and specific experimental plans about how to test whether the desired results were achieved, before managerial actions are taken. Although this is often very difficult to achieve in real situations, it is necessary for practices of management to evolve on the basis of sound empirical experience.     

省沽油中硒含量及其测定方法研究

采用消化液硝酸／高氯酸消解法、硝酸-硫酸消解法和微波消解方法消化省沽油，用原子吸收分光光度法测定硒（Se）含量。比较了3种消解方法在测定省沽油中的硒含量。发现微波消解法测定野生省沽油（干菜）中Se含量准确性好、时间段效率高、对环境污染少、操作简单。     

溆浦县枣业发展的SWOT分析及对策探讨

围绕溆浦县枣业发展的现状,运用SWOT分析方法指出该县枣业发展的优势、劣势、机会和威胁,并针对该县枣业发展的问题提出了对策。     

A COMPARISON OF STATISTICAL TESTS ON THE EXTREME-VALUE TYPE-1 DISTRIBUTION1

ABSTRACT: The effects of the selections of plotting position formulae and class division schemes on goodness of fit tests are investigated for the extreme-value type-1 distribution using annual flood and annual maximum daily rainfall data. It was found that the plotting position formulae have a minor influence on the tests which involve their use, while the class division schemes may have a pronounced effect on the X²-test. The study also recommended the maximum likelihood method for fitting purposes and a new test which is independent of the afore-mentioned selections for judging the goodness of fit.     

Utilitarian killing,replacement, and rights

The ethical theory underlying much of our treatment of animals in agriculture and research is the moral agency view. It is assumed that only moral agents, or persons, are worthy of maximal moral significance, and that farm and laboratory animals are not moral agents. However, this view also excludes human non-persons from the moral community. Utilitarianism, which bids us maximize the amount of good (utility) in the world, is an alternative ethical theory. Although it has many merits, including impartiality and the extension of moral concern to all sentient beings, it also appears to have many morally unacceptable implications. In particular, it appears to sanction the killing of innocents when utility would be maximized, including cases in which we would deliberately kill and replace a being, as we typically do to animals on farms and in laboratories. I consider a number of ingenious recent attempts by utilitarians to defeat the killing and replaceability arguments, including the attempt to make a place for genuine moral rights within a utilitarian framework. I conclude that utilitarians cannot escape the killing and replaceability objections. Those who reject the restrictive moral agency view and find they cannot accept utilitarianism's unsavory implications must look to a different ethical theory to guide their treatment of humans and non-humans.     

新疆阿克苏地区平原区高砷地下水分布特征及富集因素分析

地下水砷污染是全球化环境问题.本文基于阿克苏地区平原区2017年75个地下水砷实测含量进行分析.结果表明,研究区地下水砷含量变化范围为ND-98.70 μg?L-1,平均值为9.42μg?L-1,超标率达26.7％.水平方向上,高砷地下水主要集中在研究区的中部偏南一带;垂直方向上,山麓斜坡冲洪积砾质平原潜水区地下水砷含...     

地震学综合定量预报方法在华东地区地震预测中的应用研究

本文应用地震学综合定量预报方法,结合区域地震活动特点,在华东地区进行了分区实际预报效能检验.结果表明该方法在华东地区有5个区域通过R值检验,效果较好,有4个区域未能通过R值检验;并对通过检验的区域地震活动趋势进行了分析.     

排污权交易是控制环境问题的一种有效途径

排污权交易是解决环境外部不经济性的手段,与传统的控制环境问题手段相比,它具有在确保环境质量目标的前提下,以控制环境污染成本最小化实现资源最优配置的优点,符合我国国情,是我国控制环境问题的有效途径。     

黄土高原沙棘灌丛资源保护和发展问题

沙棘适合于在干旱瘠溥的黄土高原地区生长，在黄土高原生态恢复、环境治理和经济发展中成效显著，近年来沙棘灌丛资源发展迅速。但由于在沙棘灌丛资源保护和发展中还存在不少问题，使黄土高原区域整体效益并不理想。文章研究了黄土高原地区沙棘灌丛资源的类型，共有6个群系；分析了黄土高原沙棘灌丛资源的现状和效益，其在工矿废弃地治理、砒砂岩区治理、沙化土地治理、水土保持等方面作用明显，对当地畜牧业、食品工业、医药业起到促进作用；探讨了存在的主要问题，一是资源发展问题，二是保护问题，三是管理问题，四是科学技术问题；最后从多个方面提出了黄土高原沙棘灌丛资源保护与发展的对策，