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The mechanism of mass collaboration in risk management was studied during the Sichuan earthquake under a Web-based “PeopleFinder” project, where information is contributed and shared among mass contributors. The case study is provided by a great earthquake that happened in Wenchuan County, Sichuan Province, of southwestern China at 2:28 p.m. on May 12, 2008. We witnessed and experienced the rescue and relief efforts for the great earthquake. In this article, two fundamental frameworks are developed to study the mechanism of mass collaboration. Mass collaboration is proven to be effective in a big public crisis such as the Sichuan earthquake. 相似文献
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The aggregation of amyloid-β protein (Aβ) in vivo is a critical pathological event in Alzheimer's disease. Although more and more evidence shows that the intermediate oligomers are the primary neurotoxic species in Alzheimer's disease, the particular structural features responsible for the toxicity of these intermediates are poorly understood. We measured the peptide level solvent accessibility of multiple Aβ(1-40) aggregated states using hydrogen exchange detected by mass spectrometry. A gradual reduction in solvent accessibility, spreading from the C-terminal region to the N-terminal region was observed with ever more aggregated states of Aβ peptide. The observed hydrogen exchange protection begins with reporter peptides 20-34 and 35-40 in low molecular weight oligomers found in fresh samples and culminates with increasing solvent protection of reporter peptide 1-16 in long time aged fibrillar species. The more solvent exposed structure of intermediate oligomers in the N-termini relative to well-developed fibrils provides a novel explanation for the structure-dependent neurotoxicity of soluble oligomers reported previously. 相似文献
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Theresa M. Bert Kevin J. McCarthy Hector Cruz-Lopez Steven Bogdanowicz 《Evolution; international journal of organic evolution》1996,50(2):655-671
Many investigators categorize individuals from hybrid zones to facilitate comparisons among genotypic classes (e.g., parental, F1, backcross) for comparative studies in which components of fitness or geographic variation are being analyzed. Frequently, multiple character sets representing genetically independent traits are used to classify these individuals and various methodologies are employed to combine the classifications obtained from the different character sets. We adapted the principles of total evidence and taxonomic congruence (two formalized approaches used by systematists in formulating phylogenetic hypotheses) to address the problem of discriminating hybridizing species and classifying individuals from hybrid zones. As our model, we used two morphological (coloration and morphometric) and two molecular (allozyme and mitochondrial DNA restriction-fragment-length polymorphism) character sets that differentiate two stone crab species (Menippe adina and M. mercenaria). Using principal-components analysis, we determined that combining character sets and eliminating characters or character sets that did not have large eigenvector coefficients for the principal component that best separated the two species yielded the highest level of discrimination between species and allowed us to classify a broad range of morpho-genotypes as hybrids. For the stone crabs, three diagnostic allozyme loci and five diagnostic coloration characters best separated the species. The two character sets were not completely congruent, but they agreed in their classification of 50% of the individuals from the hybrid zone and rarely strongly disagreed in their classifications. Classification discrepancies between the two character sets probably represent variation between traits in interspecific gene flow rather than intraspecific, ecologically mediated variation. Our results support the assertions of previous investigators who espoused the benefits associated with using multiple character sets to classify individuals from hybrid zones and demonstrate that, if character sets are reasonably congruent and numerically balanced, combining diagnostic characters from multiple character sets (a total-evidence approach) can enhance discriminatory power between species and facilitate the assignment of hybrid-zone individuals to genotypic classes. On the contrary, classifying hybrid-zone individuals using character sets separately (a taxonomic-congruence approach) provides the opportunity to compare levels of introgression between species and to assess reasons for discordance among the data sets. 相似文献
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Haiyan Miao Jingjing Lu Yibing Guo Hongquan Qiu Yu Zhang Xihao Yao Xiaohong Li Yuhua Lu 《Journal of cellular and molecular medicine》2021,25(7):3654-3664
Pancreatic ductal adenocarcinoma (PDAC) is an invasive and aggressive cancer that remains a major threat to human health across the globe. Despite advances in cancer treatments and diagnosis, the prognosis of PDAC patients remains poor. New and more effective PDAC therapies are therefore urgently required. In this study, we identified a novel host factor, namely the LncRNA TP73-AS1, as overexpressed in PDAC tissues compared to adjacent healthy tissue samples. The overexpression of TP-73-AS1 was found to correlate with both PDAC stage and lymph node metastasis. To reveal its role in PDCA, we targeted TP73-AS1 using LnRNA inhibitors in a range of pancreatic cancer (PC) cell lines. We found that the inhibition of TP73-AS1 led to a loss of MMP14 expression in PC cells and significantly inhibited their migratory and invasive capacity. No effects of TP73-AS1 on cell survival or proliferation were observed. Mechanistically, we found that TP73-AS1 suppressed the expression of the known oncogenic miR-200a. Taken together, these data highlight the prognostic potential of TP73-AS1 for PC patients and highlight it as a potential anti-PDAC therapeutic target. 相似文献
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