A renormalization group approach to crowd psychology and inter-group coupling in social many-body systems

By adopting majority rule within a renormalization group approach, we can show that the strength of inter-group interaction in a social system either grows or shrinks monotonically with increasing group size, depending on the initial coupling strength of individuals in the group. This contrasts with the findings of previous studies in which the strength of the interaction grows with group size regardless of the initial strength. Our approach clearly demonstrates that the phenomena of crowd psychology, such as an extreme anti-reaction between different ethnic or ideological groups, could be a consequence of the many-particle nature of social systems when the initial strength of the interaction is larger than a critical value. The effect of neutral opinion holders is critically examined using the spin-one Ising model. The critical size of the population of neutral opinion holders, that can prevent crowd polarization, depends on the block spin rule.     

Olfactory ensheathing cells are attracted to, and can endocytose, bacteria

Olfactory ensheathing cells (OECs) have been shown previously to express Toll-like receptors and to respond to bacteria by translocating nuclear factor-kappaB from the cytoplasm to the nucleus. In this study, we show that OECs extended significantly more pseudopodia when they were exposed to Escherichia coli than in the absence of bacteria (p=0.019). Co-immunoprecipitation showed that E. coli binding to OECs was mediated by Toll-like receptor 4. Lyso-Tracker, a fluorescent probe that accumulates selectively in lysosomes, and staining for type 1 lysosome-associated membrane proteins demonstrated that endocytosed FITC-conjugated E. coli were translocated to lysosomes. They appeared to be subsequently broken down, as shown by transmission electron microscopy. No obvious adherence to the membrane and less phagocytosis was observed when OECs were incubated with inert fluorescent microspheres. The ability of OECs to endocytose bacteria supports the notion that OECs play an innate immune function by protecting olfactory tissues from bacterial infection.     

Further characterization of the effects of ultraviolet irradiation of the amphibian egg

UV-irradiation of the vegetal hemisphere of amphibian eggs leads to developmental abnormalities in neural morphogenesis. The possibility that the egg's transient sensitivity to irradiation could be due to pigmentation changes was examined in albino eggs. The tissue specificity of the effects of irradiation was analyzed by exchanging the ectoderm between irradiated and control embryos.     

Inhibition of caspase-1 slows disease progression in a mouse model of Huntington's disease.

Huntington's disease is an autosomal-dominant progressive neurodegenerative disorder resulting in specific neuronal loss and dysfunction in the striatum and cortex. The disease is universally fatal, with a mean survival following onset of 15-20 years and, at present, there is no effective treatment. The mutation in patients with Huntington's disease is an expanded CAG/polyglutamine repeat in huntingtin, a protein of unknown function with a relative molecular mass of 350,000 (M(r) 350K). The length of the CAG/polyglutamine repeat is inversely correlated with the age of disease onset. The molecular pathways mediating the neuropathology of Huntington's disease are poorly understood. Transgenic mice expressing exon 1 of the human huntingtin gene with an expanded CAG/polyglutamine repeat develop a progressive syndrome with many of the characteristics of human Huntington's disease. Here we demonstrate evidence of caspase-1 activation in the brains of mice and humans with the disease. In this transgenic mouse model of Huntington's disease, expression of a dominant-negative caspase-1 mutant extends survival and delays the appearance of neuronal inclusions, neurotransmitter receptor alterations and onset of symptoms, indicating that caspase-1 is important in the pathogenesis of the disease. In addition, we demonstrate that intracerebroventricular administration of a caspase inhibitor delays disease progression and mortality in the mouse model of Huntington's disease.     

Using quasi ionosphere-free post-processing algorithm on the medium-range kinematic high accuracy GPS relative positioning

We utilize Quasi Ionosphere-Free (QIF) post-processing algorithm to account for ionosphere delay and use addition parameters to solve for tropospheric bias. Then the estimated integer ambiguities and troposphere parameters are fixed to acquire kinematic relative positions at every epoch.Using kinematic relative positioning, data from the Taiwan continuous GPS network (TCGN) are utilized to analyze the co-seismic displacements associated with the 21 September 1999 Chi-Chi earthquake (ML=7.3). The station near the highest peak of Taiwan, Yushan (YUSN) and a station ineastem Taiwan, Fenglin (FLNM) show significant co-seismic displacements of 18 and 12 cm in the north direction as well as 16 and 24 cm in the west direction, respectively. Comparing the co-seismic displacements estimated from daily solutions with those from kinematic results, the differences are less than 2 cm in the horizontal components. The impact of the major aftershocks occurred immediately after the mainshock can be identified from the kinematic positioning. The same algorithm is also applied to study the 1 Hz sampling rate data related to 31 March 2002 off Hualien earthquake (ML=6.8), seven stations of the TCGN are analyzed to study the co-seismic deformation. With the higher sampling rate data, the instantaneous ground motion caused by the propagation of seismic waves can be observed.     

具有可变形剪切连接件的连续复合梁的结构行为

对原型双跨复合梁的结构行为给出了详细的有限元研究．由于基本上认为剪切连接件是非刚性的,在高等有限元模型中采用弹簧单元可以将它们的非线性荷载一滑移性质考虑在内．对各种原型双跨复合梁进行了参数研究,并提出了主要的研究结果．主要的结构参数包括剪切连接件在正弯矩和负弯矩区域内的变形韧性和变形程度．总共比较和讨论了9个具有不同类型和剪切件数目的复合梁的结构行为,对目前的设计缺陷进行了鉴定．由于提出的有限元模型对详细调查复合梁的结构行为非常有效,有效地利用所提出的模型将对更具有改善结构精度和效率的细化设计准则的发展有帮助．