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1.
Osteopoikilosis, Buschke-Ollendorff syndrome (BOS) and melorheostosis are disorders characterized by increased bone density. The occurrence of one or more of these phenotypes in the same individual or family suggests that these entities might be allelic. We collected data from three families in which affected individuals had osteopoikilosis with or without manifestations of BOS or melorheostosis. A genome-wide linkage analysis in these families, followed by the identification of a microdeletion in an unrelated individual with these diseases, allowed us to map the gene that is mutated in osteopoikilosis. All the affected individuals that we investigated were heterozygous with respect to a loss-of-function mutation in LEMD3 (also called MAN1), which encodes an inner nuclear membrane protein. A somatic mutation in the second allele of LEMD3 could not be identified in fibroblasts from affected skin of an individual with BOS and an individual with melorheostosis. XMAN1, the Xenopus laevis ortholog, antagonizes BMP signaling during embryogenesis. In this study, LEMD3 interacted with BMP and activin-TGFbeta receptor-activated Smads and antagonized both signaling pathways in human cells.  相似文献   
2.
Interests on climate change in the source region of Yangtze River have been raised since it is a region with the greatest warming over the Tibetan Plateau (TP). A 70-year history of precipitation δ~(18)O has been recovered using an ice core record retrieved in a plat portion of the firn area in the Guoqu Glacier (33°34′37.8″N, 91°10′35.3″E, 5720 m a.s.l.), Mt. Geladaindong (the source region of Yangtze River), in November, 2005. By using a significant positive relationship between ice core δ~(18)O record and summer air temperature (July to September) from the nearby meteorological stations, a history of summer air temperature has been reconstructed for the last 70 years. Summer temperature was relatively low in 1940s and high in 1950s to the middle of 1960s. The lowest temperature occurred in the middle of 1970s. Temperature was low in 1980s and dramatically increased since 1990s, keeping the trend to the begin-ning of the 21st century. The warming rate recorded in the ice core with 0.5℃/10 a since 1970s is much higher that that in the central TP and the Northern Hemisphere (NH), and it becomes 1.1℃/10 a since 1990s which is also higher than these from the central TP and the NH, reflecting an accelerated warm-ing and a more sensitive response to global warming in the high elevation region.  相似文献   
3.
The pressure dependence of the onset of the formation of Ta C and Ta2 C from the elements has been investigated by in situ X-ray diffraction and pyrometry.Ta C has been synthesized by the reaction of Ta and graphite at pressures between 8.6 and 14.3 GPa and at temperatures up to 2,300 K using a laser-heated diamond anvil cell. The products were characterized by X-ray diffraction. Ta and graphite begin to react around 1,100 K at ambient pressure conditions, and the reaction temperature increases with increasing pressure. A linear extrapolation of these data is consistent with recent observations of the formation of Ta C at 90 GPa and 3,600 K. We show that diffusion of carbon into tantalum significantly changes the lattice parameter of up to 2 % in the pressure range of up to19 GPa. In some experiments, Ta2 C was formed concomitantly. The experimentally determined bulk modulus of Ta2 C is B0;exp:= 286(5) GPa. Other tantalum carbide phases were not observed.  相似文献   
4.
Ready, set, hire     
Bjorn G 《Nature》2008,451(7179):740-741
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5.
Annual accumulation records covering 1935 to 2004 were reconstructed using Geladaindong ice core in the source of Yangtze River. A significant positive correlation between annual accumulation and precipitation from nearby meteorological stations was found, suggesting ice core accumulation could be taken as a precipitation proxy in the region. In the past 70 years, precipitation in the Geladaindong region was low from 1930s to early 1960s, and the lowest value occurred in the later 1950s. Since 1960s, precipitation increased dramatically and reached the maximum around 1980s, then decreased slightly in 1990s. By using Mann-Kendall rank statistical test method, a change point for precipitation was determined in 1967. Analysis of the atmospheric circulation over the Tibetan Plateau suggested that, compared with the southwest wind during the low precipitation period (before 1967), it extended about 2 latitudes northward during high precipitation period (after 1967). Moreover, during the high precipitation, the trough over the Bal Karshi Lake was also enhanced, and both the meridional wind and vapor transporting displayed a remarkable aggrandizement.  相似文献   
6.
Williams syndrome is a neurodevelopmental disorder caused by the hemizygous deletion of 1.6 Mb on human chromosome 7q11.23. This region comprises the gene CYLN2, encoding CLIP-115, a microtubule-binding protein of 115 kD. Using a gene-targeting approach, we provide evidence that mice with haploinsufficiency for Cyln2 have features reminiscent of Williams syndrome, including mild growth deficiency, brain abnormalities, hippocampal dysfunction and particular deficits in motor coordination. Absence of CLIP-115 also leads to increased levels of CLIP-170 (a closely related cytoplasmic linker protein) and dynactin at the tips of growing microtubules. This protein redistribution may affect dynein motor regulation and, together with the loss of CLIP-115-specific functions, underlie neurological alterations in Williams syndrome.  相似文献   
7.
8.
Bjorn G 《Nature》2008,454(7207):1024-1025
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9.
This study explores the political construction of Inspiria Science Center. The ambition is to bring the science center itself in focus and contribute to our understanding of the relationship between a science center and its community. It employs actor–network theory and discourse models treating the construction of Inspiria as a specific historical event, expressed in approximately 160 newspaper articles over a period of more than 10 years. The outcome describes how Inspiria Science Center transforms from a voluntary based project and kids playing with Lego bricks in the Faculty of Engineering’s basement to a national science center with Fiscal Budget funding and a regional development agenda. The outcome recognizes major disruptions and conflicts driving the transformation, exposing how the science center is not just context or an arena for someone else, but an actor in the science-learning network. Based on the findings we suggest developing specific models on the construction of a science center to increase the awareness towards mechanisms involved in gaining (and regaining) support.  相似文献   
10.
城市化进程中北京市区县经济竞争力定量分析   总被引:1,自引:0,他引:1  
应用传统偏离份额分析法, 对北京市 18 个区县1993?2002年和2005?2007年的经济发展状况进行了比较分析;应用 SPSS统计分析方法, 构建了 18 个区县经济竞争力与其影响因子之间的计量模型。结果表明, 1993?2002 年间, 城八区经济竞争力高于郊区县。2005 年后, 郊区县经济竞争力的增长高于城八区。各区县经济竞争力与财政收入、就业、大气环境质量和人均工资成正比, 与人口成反比。这些计量模型可为北京市及各区县政府通过政策工具, 合理调整 自身产业结构, 实现区域可持续发展提供依据。  相似文献   
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