Population dynamics of the bark-dwelling spider Eustala perfida Mello-Leitão, 1947 (Araneidae)

Population dynamics of spiders may vary according to biotic and abiotic factors. We studied the phenology of the bark-dwelling spider Eustala perfida over a two-year period and investigated how temperature, precipitation, and prey availability were associated with the population of this species. The population of E. perfida presented a well-defined fluctuation, with one reproductive cycle per year. The recruitment of spiders occurred in summer, followed by successive phenological peaks at all stages of development. The species is protogynic, and the population of adult males peaks in the cold/dry season, indicating a winter mature phenological pattern. The diet of E. perfida is composed mainly of medium-sized homopterans, complemented by small dipterans and hymenopterans. We found that the higher abundance of spiders occurred two months after the highest values of precipitation and temperature, and three months after the higher abundance of potential prey items. These results indicate that spiders require time to respond to changes in environmental conditions. The species’ natural history and the structure of the trunks in which it lives may also affect the number of individuals in a particular area and over time.     

Mode of débitage and technical cognition of hominids at the Guanyindong site

Exploring and interpreting the mode of cognition and behavioral patterns of prehistoric hunter-gatherers is always one of the main goals of current Paleolithic research. In the 1940s, French prehistorians proposed the technological method for studying lithic assemblages which opened a brand-new perspective on the prehistoric domain. In the 1960s, French ethnographer and anthropologist Andre Leroi-Gourhan proposed the concept ＂chaine operatoire＂ and established the theory of lithic technological study. After the 1980s, the concept ＂chaine operatoire＂ was substituted for two different but complementary concepts： techno-cognition and techno-economy, which contributed not only to revealing the technical knowledge and know-how applied during lithic production but also to interpreting the technical behavior of prehistoric hunter-gatherers from social and economic viewpoints. The lithic technological study of the Guanyindong site, presented in this paper, was carried out for the first time by applying lithic technological method developed by French prehistorians to the Chinese materials. Our analytical results demonstrated that the debitage system of Guanyindong is quite distinct from the concept Levallois largely used in Europe, Near-East and Africa. The differentiation between these two debitage modes may contribute to exploring and interpreting the relationship in Middle Paleolithic between China and Europe, Near-East and Africa.     

多目标随机规划的交互遗传算法

利用遗传算法在处理过程中不依赖问题的种类,并具有较强鲁棒性等特点,提出了一种基于交互式的求解多目标随机规划的遗传算法,算法的意思是,结合小生境技巧和构造Pareto选优过滤器的手段,通过与决策者的反复交互对话,最后得到使决策者满意的问题的Pateto有效解集。     

论软动力学的系统辩证思维特征

从哲学内涵上探讨了软动力学的方法论意义 ,并对软动力学理论模型及其核心概念中的辩证思维特征作了延伸性分析     

The karyotype ofOxymycterus sp (Cricetidae,Rodentia) from Central Brazil

Cytogenetical data, including G-, C-bands and NORs distribution ofOxymycterus sp (2n=54; FN=64) captured in Distrito Federal, state of Goiás, Central Brazil are presented. Our results are compared to the karyotype information already available on this genus.     

Effect of actinomycin D onTrypanosoma cruzi

Summary Viable metacyclic forms ofT. cruzi, Y strain, treated with an adequate dose of actinomycin D (50 g Act-D/ml/10⁷ parasites/ml for 72 h at 28° C) showed the following properties: 1) they lost their ability to replicate in culture medium, in blood and in tissues of normal mice and were no longer able to incorporate tritiated thymidine; 2) they could no penetrate into Vero cells and could not replicate inside normal macrophages; 3) they retained their immunogenicity and the ability to protect mice against a virulent infection; 4) they did not induce histological lesions as described in chronic experimental Chagas' disease.