我国全民健身“大群体”格局发展战略及推进路径

通过对全民健身"大群体"格局发展内涵的解读,分析了我国全民健身"大群体"格局发展的基本特征:发展过程始终坚持全面普及与重点推进,管理体制由政府"垄断式"管理向"分权化"管理转变,发展目标与竞技体育"协调"发展到"全面"发展的转变。同时,研究提出要完善和巩固全民健身"大群体"格局发展的长效机制,其推进路径可通过构建多元化全民健身服务供给体系,建立全民决策参与机制,设立多元问责监管机制,健全部门协同机制和完善示范引导与评估激励机制五种具体举措来实现。

论居家养老服务对我国老年人体育事业发展的支持

居家养老服务对我国老年人体育事业发展提供了一种资源整合性支持,体现了非体育组织在老年人体育事业发展中的积极作用,提升了体育部门和养老部门在老年人体育事业发展中的合力,契合了我国当下全民健身工作的"大群体"工作思路。发挥居家养老服务对我国老年人体育事业发展的支持,需以跨界整合和整体思维理念为指导,形成一个以全国老龄事业委员会为主导,体育、民政等相关部门协同配合的老年人体育运行机制。

Polygynous Mating System and Behavioural Reason of Black Crested Gibbon (Nomascus concolor jingdongensis) at Dazhaizi,Mt.Wuliang, Yunnan,China

The field research on five black crested gibbon groups, recently performed at Dazhaizi, Mr. Wuliang, Central Yunnan, China, showed that all groups in the local population consisted of one adult male, two adult females and 2 - 5 sub-adults, juveniles and itfants. The mean group size was 6.2 in August 2003 and 6.4 in August 2005. Two subadult males disappeared from their natal home range and three newborns were given birth in Group 3 （G3） and G4 during this study. The two adult females in G1, G2 and G3 gave births and/or carried babies but at different times. There was no aggressive or dominating behaviour observed between the two adult females. One floating female was first seen in G3＇s territory on April 15, 2005. The two resident females interrupted her duet with adult male and chased her. We did not observe adult male chased this floating female and she left G3＇s territory 10 days later. Sub-adult males often kept distance with the family, and they often sang solo bouts in their natal territory before they dispersed. The sub-adult males and females dispersed from natal territory and two adult resident females rejected the third one, which might were the reasons why the black gibbon groups were polygyny in Dazhaizi.

LsrR-binding site recognition and regulatory characteristics in Escherichia coli AI-2 quorum sensing

In quorum sensing （QS） process, bacteria regulate gene expression by utilizing small signaling molecules called autoinducers in response to a variety of environmental cues. Autoinducer 2 （AI-2）, a QS signaling molecule proposed to be involved in interspecies communication, is produced by many species of gram-negative and gram-positive bacteria. In Escherichia coil and Salmonella typhimurium, the extracellular AI-2 is imported into the cell by a transporter encoded by the lsr operon. Upstream of the lsr operon, there is a divergently transcribed gene encoding LsrR, which was reported previously to repress the transcription of the lsr operon and itself. Here, we have demonstrated for the first time that LsrR represses the transcription of the lsr operon and itself by directly binding to their promoters using gel shift and DNase I footprinting assays. The β-galactosidase reporter assays further suggest that two motifs in both the lsrR and lsrA promoter regions are crucial for the LsrR binding. Furthermore, in agreement with the conclusion that phosphorylated AI-2 can relieve the repression of LsrR in previous studies, our data show that phospho- AI-2 renders LsrR unable to bind to its own promoter in vitro.

An EAL domain protein and cyclic AMP contribute to the interaction between the two quorum sensing systems in Escherichia coli

Quorum sensing （QS） is a bacterial cell-cell communication process by which bacteria communicate using extracellular signals called autoinducers. Two QS systems have been identified in Escherichia coli K-12, including an intact QS system 2 that is stimulated by the cyclic AMP （cAMP）-cAMP receptor protein （CRP） complex and a partial QS system 1 that consists of SdiA （suppressor of cell division inhibitor） responding to signals generated by other microbial species. The relationship between QS system 1 and system 2 in E. coli, however, remains obscure. Here, we show that an EAL domain protein, encoded by ydiV, and cAMP are involved in the interaction between the two QS systems in E. coli. Expression of sdiA and ydiV is inhibited by glucose. SdiA binds to the ydiV promoter region in a dose-dependent, but nonspecific, manner; extracellular autoinducer 1 from other species stimulates ydiV expression in an sdiA-depen- dent manner. Furthermore, we discovered that the double sdiA-ydiV mutation, but not the single mutation, causes a 2-fold decrease in intracellular cAMP concentration that leads to the inhibition of QS system 2. These results indicate that signaling pathways that respond to important environmental cues, such as autoinducers and glucose, are linked together for their control in E. coli.

Genetic Variation Assessed with Microsatellites in Mass Selection Lines of the Pacific Oyster (Crassostrea gigas) in China

Abstract Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding pro- grams in China were examined at ten polymorphic microsatellite loci to assess the level of allelic diversity and estimate the effective population size. These data were compared with those of their base population. The results showed that the genetic variation of the four generations were maintained at high levels with an average allelic richness of 18.8-20.6, and a mean expected heterozygosity of 0.902-0.921. They were not reduced compared with those of their base population. Estimated effective population sizes based on temporal variances in microsatellite frequencies were smaller to that of sex ratio-corrected broodstock count estimates. Using a rela- tively large number ofbroodstock and keeping an equal sex ratio in the broodstock each generation may have contributed to retaining the original genetic diversity and maintaining relatively large effective population size. The results obtained in this study showed that the genetic variation was not affected greatly by mass selection progress and high genetic variation still existed in the mass selection lines, suggesting that there is still potential for increasing the gains in future generations of C. gigas. The present study provided im- portant information for future genetic improvement by selective breeding, and for the design of suitable management guidelines for genetic breeding of C. gigas.

Assessment of parental contribution and effective population size from a 3×3 diallel cross of clam Meretrix meretrix

Unbalanced parental contribution and small effective population size （Ne） are common issues during the artificial breeding of marine bivalves. The impact of hatchery-spawning practices on parental contribution, effective population size, the Ne/Nratio, and genetic diversity are largely unknown. To address this, we conducted a parentage analysis on a complete 3×3 diallel cross of clam Meretrix meretrix using eight microsatellite markers. The genetic diversity of the parents was higher than that of their respective offspring in most crosses （8/9）. Sires or dams from the same family contributed unequally to the pool of offspring from a particular cross, and the same parent clam exhibited large variation in parental contribution among different crosses. The variance in male contribution was higher than that of the female contribution in most crosses, suggesting that male contribution was more skewed than for females. The No/N ratio for nine crosses ranged from 0.58 to 0.86. There was no linear relationship between the sex ratio and the Ne/Nratio （P〉0.05）. Moreover, a sex ratio closer to one-to-one does not necessarily mean a larger effective population size. A solution to small effective population size in commercial breeding programs is increasing broodstoek numbers and attempting to maintain a balanced sex ratio.

The Effect of Selective Logging on the Nest Density, Foraging Range and Colony Size on the Ground-Dwelling Ant Aphaenogaster Swammerdami Forel, 1886 in Kirindy ForestmMadagascar

Studying the ecology of ants can be a powerful tool for conservation, While the effect of logging is mainly investigated by the comparison of species richness and composition, the impact on individual species are often neglected. This study investigated the effect of selective logging on the nest density, foraging range and colony size on the ground-dwelling ant Aphaenogaster swammerdami in Kirindy forest--Madagascar. This ant is a common ground-dwelling species in Kirindy, a western dry deciduous forest of Madagascar. Sampling was done in two sites of the forest： One part that was selectively lodged and another that have not been logged. Here we show that selective logging led to a decrease in colony size and density, while the foraging range seemed to be unaffected. Higher desiccation stress and lower food availability in the logged forest are most likely to be responsible for these results.

Morphology and ontogeny of dendritic cells in rats at different development periods

AIM： To study the morphology and ontogeny of dendritic cells of Peyer＇s patches in rats at different development periods. METHODS： The morphometric and flow cytometric analyses were performed to detect all the parameters of villous-crypts axis and the number of OX62＋DC, OX62＋CD4＋SIRP＋DC, and OX62＋CD4-SIRP-DC in the small intestine in different groups of rats. The relationship between the parameters of villous-axis and the number of DC and DC subtype were analyzed. RESULTS： All morphometric parameters changed significantly with the development of pups in the different age groups （F = 10.751, 12.374, 16.527, 5.291, 3.486; P = 0.000, 0.000, 0.000, 0.001, 0.015）. Villous height levels were unstable and increased from 115.24μm to 140.43 μm as early as 3 wk postpartum. Villous area increased significantly between 5 and 7 wk postpartum, peeked up to 13817.60 tam2 at 7 wk postpartum. Villous height and crypt depth ratios were relatively stable and increased significantly from 2.80 ＋ 1.01 to 4.54 =1= 1.56, 9-11 wk postpartum. The expression of OX62＋DC increased from 33.30%±5.80% to 80%± 17.30%, 3-11 wk postpartum （F =5.536, P = 0.0013）. OX62＋CD4＋SIRP＋DC subset levels detected in single-cell suspensions of rat total Peyer＇s patch dendritic cells （PP-DCs） increased significantly from 30.73% ± 5.16% to 35.50% ± 4.08%, 5-7 wk postpartum and from 34.20% ±1.35% to 43.60% ± 2.07% 9-11 wk postpartum （F = 7.216, P = 0.005）. CONCLUSION： This study confirms the agerelated changes in villous-crypt axis differentiation in the small intestine. Simultaneously, there are also development and maturation in rat PP-DCs phenotypic expression. Furthermore, the morphological changes of intestinal mucosa and the development of immune cells （especially DC） peaked at 9-11 wk postpartum, indicating that the intestinal mucosae reached a relatively mature state at 11 wk postpartum.

Evaluating the Ryman-Laikre effect for marine stock enhancement and aquaculture

The Ryman-Laikre （R-L） effect is an increase in inbreeding and a reduction in total effective population size （NET） in a combined captive-wild system, which arises when a few captive parents produce large numbers of offspring. To facilitate evaluation of the R-L effect for scenarios that are relevant to marine stock enhancement and aquaculture, we extended the original R-L formula to explicitly account for several key factors that determine NeT, including the numbers of captive and wild adults, the ratio of captive to wild Ne/N （β）, productivity of captive and wild breeders, and removal of individuals from the wild for captive breeding. We show how to provide quantitative answers to questions such as： What scenarios lead to no loss of effective size？ What is the maximum effective size that can be achieved？ and What scenarios insure that NeTWill be no smaller than a specified value？ Important results include the following： （1） For large marine populations, the value of β becomes increasingly important as the captive contribution increases. Captive propagation will sharply reduce NeT unless the captive contribution is very small or β is very large （～10^3 or higher）. （2） Very large values of β are only possible if wild Ne/N is tiny. Therefore, large wild populations undergoing captive enhancement at even modest levels will suffer major reductions in effective size unless wild Ne is a tiny fraction of the census size （about 10 4 or lower）.

Reproductive traits of the gray ratsnake Ptyas korros from three geographically distinct populations

Abstract We collected gravid gray rat snakes Ptyas korros from three geographically distinct populations in China, Chenzhou （CZ）, Jiangshan （JS） and Dinghai （DH）, to study geographical variation in female reproductive traits. Egg-laying dates differed among the three populations such that at the most northern latitude egg-laying was latest, and earliest at the most southern latitutde. Clutch size, clutch mass, egg mass, egg shape, within clutch variability in egg sizes and relative clutch mass differed among the three populations, whereas post-oviposition body mass did not. Except for egg-laying date, none of the traits examined varied in a geographically continuous trend. CZ and DH females, although separated by a distance of approximately 1100 km as the crow flies, were similar in nearly all traits examined. JS females were distinguished from CZ and DH females by their higher fecundity （clutch size）, greater reproductive output （clutch mass） and more rounded eggs. Our data do not validate the prediction that larger offspring should be produced in colder localities. The absence of an egg size-number trade-off in each of the three populations presumably suggests that P. korros is among species where eggs are well optimized for size within a population.