8～12岁男孩的性激素与智力、人格的关系

Recently there emerged more and more researhes concerning about sex hormone-related cognitive ability and behaviours. Few were carried out in pre- to early adolescent children., and the objective of the current study is to investigate whether there are covariance between sex hormones, intelligence and personality in 232 pre- to early adolescent boys, including 62 gifted boys. Indexes of sex hormone levels were salivary testosterone and estradiol concentrations, the 2D:4D digit ratio ( a reliable pointer of prenatal sex hormone concentraions). The Cattell Culture Fair Intelligence Test and a Chinese version of Children’s Personality Questionaire was applied in the current study. The main findings are: 1) salivary sex hormone concentrations significantly positively correlated with intelligence performance in 10-year-old boys; 2) salivary testosterone negatively related to intelligence performance in 12-year-old boys; 3) gifted boys bears lower testosterone concentrations in both prenatal period and pre- to early adolescence; 4) for personality, higher salivary estradiol was related to extraversion and digit ratios correlated with several personality factors in 8-year-old boys. In conclusion, results in the current study suggested that for male early maturers, intelligence may be negatively influenced by early coming androgen surge. In contrast, male late matures may benefit from their lately and moderately increasing hormone. Besides, the results suggested that the relationship between 2D:4D digit ratio and personality may also be paid attention to.

Enriched environment experience overcomes the memory deficits and depressive-like behavior induced by early life stress

Stress in early life is believed to cause cognitive and affective disorders, and to disrupt hippocampal synaptic plasticity in adolescence into adult, but it is unclear whether exposure to enriched environment (EE) can overcome these effects. Here, we rep

Vortex motion in the early stages of unsteady flow around a circular cylinder

In this paper, processes in the early stages of vortex motion and the development of flow structure behind an impulsively-started circular cylinder at high Reynolds number are investigated by combining the discrete vortex model with boundary layer theory, considering the separation of incoming flow boundary layer and rear shear layer in the recirculating flow region. The development of flow structure and vortex motion, particularly the formation and development of secondary vortex and a pair of secondary vortices and their effect on the flow field are calculated. The results clearly show that the flow structure and vortices motion went through a series of complicated processes before the symmetric main vortices change into asymmetric: development of main vortices induces secondary vortices; growth of the secondary vortices causes the main vortex sheets to break off and causes the symmetric main vortices to become “free” vortices, while a pair of secondary vortices is formed; then the vortex sheets, after breaking off, gradually extend downstream and the structure of a pair of secondary vortices becomes relaxed. These features of vortex motion look very much like the observed features in some available flow field visualizations. The action of the secondary vortices causes the main vortex sheets to break off and converts the main vortices into free vortices. This should be the immediate cause leading to the instability of the motion of the symmetric main vortices. The flow field structure such as the separation position of boundary layer and rear shear layer, the unsteady pressure distributions and the drag coefficient are calculated. Comparison with other results or experiments is also made.

PIXE and ICP-AES analysis of early glass unearthed from Xinjiang (China)

Early glasses (about 1066 BC-220 AD) unearthed from Xinjiang of China were chemically characterized by using PIXE and ICP-AES. It was found that these glasses were basically attributed to PbO-BaO-SiO2 system, K2O-SiO2 system, Na2O-CaO-SiO2 system and Na2O-CaO-PbO-SiO2 system. The results from the cluster analysis showed that some glasses had basically similar recipe and technology. The PbO-BaO-SiO2 glass and the K2O-SiO2 glass were thought to come from the central area and the south of ancient China, respectively. The part of the Na2O-CaO-SiO2 glass (including the Na2O-CaO-PbO-SiO2 glass) might be imported from Mesopotamia, while the other part might be locally produced. (c) 2005 Elsevier B.V. All rights reserved.