糖在猕猴精子低温冷冻保存过程中的作用

TTE或TEST防冻液在冻存猕猴精子时产生不同结果，其主要不同在于防冻液中糖成分的不同。实验结果表明，冷冻复苏过程对精子结构产生了影响，TTE法低温保存的猕猴精子的头部的质膜出现少许皱褶或泡化现象，但精子的顶体、核或是精子尾部的结构与鲜精的结构基本相似。猕猴精子经TEST法低温保存后，大部分精子结构则发生了明显的变化，精子膜、顶体和精子核明显泡化、损伤或破裂，精子尾部不能分辨出正常的超微结构。这提示，可能由于TTE防冻液中复杂的糖成分在降温/复苏过程对精子起到了较好的协同冷冻保护作用；而TEST防冻液中单一的糖成分不能完全保护精子避免低温损伤，低温保存过程破坏了精子的结构，并影响了复苏后精子体外存活能力与受精能力。

大脑前额叶皮层与免疫机能的关系Ⅰ.损毁前额叶皮层对猕猴淋巴细胞免疫机能的影响

用临床细胞免疫学检测方法, 对损毁大脑前额叶背外侧部皮层手术前、手术后7天和手术后30天的猕猴外周血液淋巴细胞的4种免疫花环(Et、Ea、ZYC 和 ME 花环）进行了跟踪监测, 并与假手术组进行对照. 结果表明: 损毁大脑前额叶皮层后, 其外周血活化 T 淋巴细胞花环率（Ea）和 B 淋巴细胞的小鼠红细胞花环率（ME）均在手术后7天显著下降; 直到手术后30天仍显著低于手术前. 而总 T 淋巴细胞花环率（Et）和酵母多糖补体复合物花环率（ZYC）则在手术后7天显著下降, 在手术后30天又回复. 这些结果提示: 大脑前额叶皮层对机体免疫机能具有一定的调节联系作用, 损毁大脑前额叶皮层对机体免疫机能具有一定的调节联系作用, 损毁大脑前额叶皮层后, 可引起机体淋巴细胞免疫功能下降, 其作用机理尚待进一步研究。

发光蚯蚓的发光体系研究进展

发光蚯蚓在世界范围内广泛分布.大多数发光蚯蚓的发光体系包含于蚯蚓体腔液内充满颗粒的细胞内.早期对不同种发光蚯蚓的生理学及生物化学方面的对比研究表明大多数发光蚯蚓的发光体系是类似的,但最近对线蚓科的两个种的研究发现它们不仅发光源的定位特殊,而且发光反应所需要的成分也明显不同于其他种类.本文对发光蚯蚓的发光器官和发光体系的研究现状及其进展进行了综述,并将有代表性的发光蚯蚓的发光体系进行了对比总结.

Distribution of endangered native fish fauna and their conservation in Lake Victoria

Lake Victoria in East Africa, supports socio-economically important fisheries for more than 30 million inhabitants in the lake basin. The lake had until the 1970's a diverse fish assemblage dominated by haplochromines species which formed at least 83% of the fish biomass (Kudhongania & Cordone 1974). The more than 500 haplochromine species in Lake Victoria, over 99% of them endemic, exploited virtually all the food sources in the lake (Witte and van Oijen 1990). Each species had its own unique combination of food and habitat preference (Goldschmidt et al., 1990).

Physical and chemical characteristics of major aquatic ecosystems in the Victoria and Kyoga lake basins

The physical-chemical characteristics of any aquatic ecosystem include pH, conductivity, and temperature, water transparency, nutrient and the chlorophyll-a levels. Physical and chemical factors of any ecosystem determine the type and quality of flora present in it and these forms the basis on which the system operates. The elements required in largest amounts for plant productions are carbon, phosphorus, nitrogen, and silicon, which is important for diatoms as a major component of the cell wall. Nutrients may limit algal productivity in the tropics despite the high temperature there allowing rapid nutrient recycling. Nutrients most likely to be limiting African lakes are nitrogen (Talling & Talling 1965; Moss 1969; Lehman & Branstrator 1993, 1994) and phosphorus (Melack.et al l982; Kalff 1983) while silicon may limit diatom growth (Hecky & Kilham 1988). The objective of the study is to investigate the impact of physical-chemical characteristics on the distribution and abundance of organisms in the major aquatic ecosystems.

EARLY MOTHER-INFANT RELATIONSHIPS OF MACACA-THIBETANA AT MT-EMEI CHINA

Quantitative data on early mother-infant relationships in the Tibetan macaque was collected during the first 23 weeks of infant life in spring, 1987, at Mt. Emei, China. During the first week of life, infants spent 98.3% of their time in ventroventral contact with their mothers. This contact rapidly decreased to 33.8% by the 4th week and thereafter to 0.85% by the 23rd week. Nipple contact decreased relatively slowly from 89.7% to 62.9% within the first 4 weeks of infant life and to 19.8% by the 23rd week. Ventrolateral and ventrodorsal contact appeared by the 2nd week, mean-while, maternal restraining behavior appeared, and reached a peak by the 3rd week. The mother neither encouraged nor discouraged her infant's independence during 4-8th weeks. Maternal rejection of the infant was first observed when the infant was 11 weeks old and continued thereafter.

The biology and ecology of native non-cichlids in the Victoria and Kyoga lake basins

An overview of the biology and ecology of some of the constantly less important commercial species is given below. These included Bagrus docmac, Clarias gariepinus, Protopterus aethiopicus, Labeo victorianus, Barbus spp, Mormyrids, Synodontis spp, and Schilbe intermedius. The stocks of most of these species declined due to over-exploitation and introduction of non-native fishes especially Nile perch. A few of these taxa still survive in the main lake and others in satellite lakes. The current status of these species in the Victoria lake basin is not known but the available information provided some information on some habitat and other requirements of some of these originally important species of the Victoria lake basin.

The biology, ecology, distribution and conservation of surviving haplochromine cichlids in Lakes Victoria, Kyoga and Nabugabo

Haplochrmine cichlids were the most abundant taxa in Lakes Victoria, Kyoga and Nabugabo prior to introduction of the Nile perch. As stocks of the introduced predator increased, these taxa were depleted to such an extent that they are now virtually absent from the lake. The haplochromine cichlids played an important role in the ecology of Lakes Victoria, Kyoga and Nabugabo. They occupied virtually all trophic levels in the lake and facilitated an efficient flow of energy through the ecosystem. Their depletion seem to have left much organic matter whose decomposition has contributed to accumulation of dead organic matter which may be contributing to prolonged anoxia in Lake Victoria. The haplochromines formed an important small-scale fishery. Fishermen formerly subsisting on this fishery have been driven out of business because they cannot afford the expensive nets required for Nile perch fishery. In addition to providing a cheap source of fish protein to humans, the species were an important source of Scientific material for students of genetics antd adaptive radiation.

Economic impacts of globalisation at the district, landing site and sub-sector enterprise levels on Lakes Kyoga, Albert and Victoria

The Globalisation and fish utilisation and marketing study is a collaboration between the Fisheries Resources Research Institute (FIRRI) and the Mike Dillon Associates Limited , with funding from the Department for International Development (DFID) of the Government of the United Kingdom. The study is designed to examine the impact of the development of the export fishery on the fish producers, processors, traders and consumers in the artisanal fishery in Uganda. FIRRI 's role is to collect field data relating to the livelihoods of artisanal fish producers, processors, traders and consumers. in particular data relating to income and revenue flow. The initial focus is on the eccnomic structure of fish landing sites. The purpose of this paper is to review the progress in implementation of the project and present the interim findings for discussion. During the first quarter, namely April to June, 2002, work was carried out on Lakes Kyoga and Albert and a report produced. During the second quarter, July to September, 2002, Lake Victoria was covered. In both phases, the focus has been on the economic structure of fish landings.

The marketing, processing and distribution implications of trawling on Lake Victoria

Work which has been carried out by exploratory and stock assessment scientists indicates that some 200,000 metric tons of freshwater fish could be harvested annually from Lake Victoria. Haplochromis forms approximately 83 per cent of the total stocks

Development of the 28-foot inboard-engined fishing boat in Uganda

With the encouraging results of trawling experiments in Lake Victoria, it became apparent early in 1969 that commercial trawling on Lake Victoria might well be a viable economic enterprise. Considerable discussion about the optimum size and type of fishing vessel ensued, and the Fisheries Department decided to commission a number of different prototypes for comparative trials.

Cambodia: towards a modern commons

The Community Fisheries organizations in Cambodia possess the basic framework and principles to be considered good examples of a created ‘modern commons’....