Insecticide fingerprinting tecinique for detection and location of organochlorine insecticide rssiduss in foods

Abstract

Insecticide fingerprinting technique enables the detection and location of DDT and HCII residues in vegetables through the development of green and Prussian blue colors respectively. Cut vegetables are pressed against o‐tolidine impregnated paper and exposed to sunlight where colored spots appear instantly. The studies on 18 vegetable varieties revealed the pesticide residues and their distribution in different tissues. This direct method is sensitive (0.3 μg for HCII & 0.5 μg for DDT) and has special applications in quality control laboratorios and food industry.     

The development and applications of a Drought Early Warning System in Botswana*

This article describes the indicators and data sources used by the Botswana Drought Early Warning System formally established in early 1984, the main uses of the indicators in the assessment of drought conditions and the design of relief programmes are outlined. Limitations of the sources of data available are discussed, as is the feasibility of adding some possible further indicators. In conclusion, the importance of a functioning Early Warning System in a country highly susceptible to repeated droughts is stressed, in the context of die current effort to elaborate a comprehensive National Food Strategy and to establish a Regional Early Warning System for Southern Africa.     

广西沿江重镇洪灾特点及减灾对策

阐述了广西沿江重镇洪灾的主要特点：暴雨强度大、洪水灾发性强、抗灾能力低，探讨了致灾的成因；指出了防洪减灾的主要对策是强调工程与非工程防洪措施相结合，建立全流域综合防洪体系及根据各城市的具体情况采取针对性的措施。     

From drought relief to post-disaster recovery: The case of Botswana

This article discusses the initiative of the Government of Botswana in formulating and introducing a programme to assist recovery in rural areas after the present drought period as an important aspect of the national development effort. It examines the process by which this Post Drought Recovery Programme was arrived at, its limitations, the extent of its appropriateness to longer-term factors which render rural households more vulnerable to drought, and suggests conclusions which may be drawn to inform the design of similar programmes elsewhere.     

Methods of increasing food self-sufficiency following disasters in the commonwealth Caribbean*

In the Caribbean, catastrophic events take their toll on food availability through loss of food crops and livestock, disruption in the channels of distribution and loss of foreign exchange earnings from export crops, which are used to procure imported foodstuffs. Nutritional consequences such as the protein energy malnutrition among children, pregnant and lactating women and hard-working males and females are likely to follow. Choice of crops and livestock systems following disasters should be such as to allow for a rapid rehabilitation of the agricultural production and distribution system to eliminate prolonged dependence on food aid. Opportunities should be provided for balanced meal plans including staples, legumes, vegetables, food from animals, fruits, oils and fats. These issues are addressed in this article.     

Influence of biomass density and food to microorganisms ratio on the mixed culture type I methanotrophs enriched from activated sludge

Methanotrophic based process can be the remedy to offset the wastewater treatment facilities increasing energy requirements due to methanotroph's unique ability to integrate methane assimilation with multiple biotechnological applications like biological nitrogen removal and methanol production. Regardless of the methanotrophic process end product, the challenge to maintain stable microbial growth in the methanotrophs cultivation bioreactor at higher cell densities is one of the major obstacles facing the process upscaling. Therefore, a series of consecutive batch tests were performed to attentively investigate the biomass density influence on type I methanotrophs bacterial growth. In addition, food to microorganisms(F/M), carbon to nitrogen(C/N) and nitrogen to microorganisms(N/M) ratio effect on the microbial activity was studied for the first time. It was clarified that the F/M ratio is the most influencing factor on the microbial growth at higher biomass densities rather than the biomass density increase, whereas C/N and N/M ratio change, while using nitrate as the nitrogen source,does not influence methanotrophs microbial growth. These study results would facilitate the scaling up of methanotrophic based biotechnology by identifying that F/M ratio as the key parameter that influences methanotrophs cultivation at high biomass densities.     

鼓楼区饮食娱乐服务业环境污染调查

对鼓楼区922家饮食娱乐服务企业环境污染现状进行了调查与分析。提出应通过合法程序尽早出台《鼓楼区饮食娱乐服务企业环境保护管理实施办法》。对具有饮食娱乐服务功能的商业用房、新建项目审批、污染扰民老企业进行严格限制，明确政府各部门的审批、管理职责，结合创建绿色社区工作，对现行污染严重、群众反映强烈、影响大的饮食娱乐服务企业，由环保、工商、卫生、城建、公安、市容等部门联合执法。     

Effects of food availability on dispersal and cub sex ratio in the Mednyi Arctic fox

Since the Pleistocene, Arctic foxes, Alopex lagopus, on Mednyi Island in the North Pacific have been isolated in a small area with rich food resources and no other terrestrial carnivores. This situation provides an unusually simple system within which the effect of food dispersion on demography and social organisation was examined. We studied the composition, location and dispersal of 67 Arctic fox groups and mapped their major food resources (seabird colonies) during 1994–2000 on Mednyi. We compared our observations with the predictions of models of sex-ratio determination. Our observations are most consistent with the predictions of Julliard's (2000) model, where mothers are expected to produce more offspring of the most dispersing sex in low-quality habitats, and more offspring of the most philopatric sex in high-quality habitats. The polygynous foxes on Mednyi Island lived where the principal food resources were patchily distributed (present on 11% of the shoreline), and cub survival to dispersal age or reproductive adult was higher in rich (25/45) than in poor (24/79) home ranges. Furthermore, dispersal was strongly sex-biased: most females (60%) remained on their natal ranges, whereas very few males (9%) did so. Significantly more female than male cubs (54 compared with 24) emerged from dens in resource rich ranges, whereas the sex ratio on poor ranges was approximately equal (51 females and 56 males). While our observations are also to some extent consistent with the local resource enhancement (LRE) hypothesis (which predicts a bias towards the sex most likely to cooperate with parents), this does not account for the observed spatial variability.     

What is hidden behind the concept of ecosystem efficiency in energy transformation?

The number of energy transformation levels in trophic webs is usually below five, but can be extended up to ten when parasites and hyper-parasites are included. Research on the structure and function of food webs is relevant to the complexity–stability–productivity debate. The aim of this theoretical analysis is to link energetic and connectional aspects of ecosystems with information theory. Updating an energetic model reported by Ricklefs [Ecologia, Zanichelli Editore S.p.A., Bologna, Italy, 1993, p. 896], our approach is integrated with a static analysis of food webs. The length of food webs is theoretically associated with the average ecological efficiency which can be empirically correlated with the effective connectance between species. Furthermore, the advantage of greater complexity when applied to a signalling network is qualitatively addressed.The overall efficiency of energy transformation into biomass throughout a trophic web, in an ecosystem with a given number of species, is the resultant of the various ecological efficiencies, η, at the transitions between the trophic levels. However, we propose that an increment in effective connectance and interspecies connectivity based on a superimposed signalling web may increase the η values, despite the fact that signalling per se has an energetic cost. According to this hypothesis, ecosystem stability would not be necessarily reduced by increasing the number of trophic levels, N, whenever stability in terms of persistence is improved by a cost-efficient regulatory network.