基于随机森林赋权和改进ELECTRE-Ⅲ方法的科技奖励评价研究

针对科技奖励评价中各指标权重的不确定性问题,提出随机森林赋权法,利用可靠性分析计算专家评分数据的泛化误差,根据最小错误率得到各评价项目的各评价指标权重,减少主观赋权的影响;引入一致可信度、非一致可信度和净可信度信息,提出改进的ELECTRE-Ⅲ方法,将某一评价项目优于其他评价项目的程度具体量化,解决专家评分数据为次序变量的问题.实证表明:随机森林赋权法和改进后的ELECTRE-Ⅲ方法相结合,既提高了权重估计的精确度和可信度,又解决了难以给定门槛值和不能完全排序的问题,使评价结果更加科学、客观、合理.     

Protein intrinsic disorder as a flexible armor and a weapon of HIV-1

Many proteins and protein regions are disordered in their native, biologically active states. These proteins/regions are abundant in different organisms and carry out important biological functions that complement the functional repertoire of ordered proteins. Viruses, with their highly compact genomes, small proteomes, and high adaptability for fast change in their biological and physical environment utilize many of the advantages of intrinsic disorder. In fact, viral proteins are generally rich in intrinsic disorder, and intrinsically disordered regions are commonly used by viruses to invade the host organisms, to hijack various host systems, and to help viruses in accommodation to their hostile habitats and to manage their economic usage of genetic material. In this review, we focus on the structural peculiarities of HIV-1 proteins, on the abundance of intrinsic disorder in viral proteins, and on the role of intrinsic disorder in their functions.     

Evidence of widespread selection on standing variation in Europe at height-associated SNPs

Strong signatures of positive selection at newly arising genetic variants are well documented in humans, but this form of selection may not be widespread in recent human evolution. Because many human traits are highly polygenic and partly determined by common, ancient genetic variation, an alternative model for rapid genetic adaptation has been proposed: weak selection acting on many pre-existing (standing) genetic variants, or polygenic adaptation. By studying height, a classic polygenic trait, we demonstrate the first human signature of widespread selection on standing variation. We show that frequencies of alleles associated with increased height, both at known loci and genome wide, are systematically elevated in Northern Europeans compared with Southern Europeans (P < 4.3 × 10(-4)). This pattern mirrors intra-European height differences and is not confounded by ancestry or other ascertainment biases. The systematic frequency differences are consistent with the presence of widespread weak selection (selection coefficients ～10(-3)-10(-5) per allele) rather than genetic drift alone (P < 10(-15)).     

Mutations in SWI/SNF chromatin remodeling complex gene ARID1B cause Coffin-Siris syndrome

We identified de novo truncating mutations in ARID1B in three individuals with Coffin-Siris syndrome (CSS) by exome sequencing. Array-based copy-number variation (CNV) analysis in 2,000 individuals with intellectual disability revealed deletions encompassing ARID1B in 3 subjects with phenotypes partially overlapping that of CSS. Taken together with published data, these results indicate that haploinsufficiency of the ARID1B gene, which encodes an epigenetic modifier of chromatin structure, is an important cause of CSS and is potentially a common cause of intellectual disability and speech impairment.     

Soil water and temperature response to prescribed burning

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Prescribed burning of Texas wintergrass ( Stipa leucotricha Trin. & Rupr.) communities reduced soil water contents for two to six months, and additional reductions occurred when the subsequent crop of cool-season grasses and forbs began growth. These soil water reductions occurred despite reduced plant production following burning. Soil water reductions were greater at 15 to 45 cm depths than in the upper 15 cm and greater following spring burning. Soil temperatures were higher on burned plots for most of the first year following burning. &nbsp;&nbsp;     

Plant and soil relationships in two hydrothermally altered areas of the Breat Basin

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} In two areas of hydrothermally altered rocks in the Great Basin, the native vegetation differs in composition and areal cover from unaltered to altered sites on the same geologic formations. Analysis suggests that physical rather than chemical factors may be the cause of the vegetation differences, especially permeability of bedrock, depth and texture of soils, and, possibly, amounts and types of clay minerals present. These characteristics influence the ability of soils to absorb and retain water. In the East Tintic Mountains, Utah, the soils from argillized or mixed argillized and silicified parent materials have more characteristics associated with dryness and support sparser vegetation and more species especially adapted to dry conditions than do soils from unaltered or silicified parent materials. In Battle Mountain, Nevada, unaltered areas have greater vegetation cover and have soil depth and texture that are more favorable for plants than do altered areas. Soil pH is higher in altered areas than in unaltered areas.     

Optimal Hedge Ratio Estimation and Effectiveness Using ARCD

This paper examines the importance of forecasting higher moments for optimal hedge ratio estimation. To this end, autoregressive conditional density (ARCD) models are employed which allow for time variation in variance, skewness and kurtosis. The performance of ARCD models is evaluated against that of GARCH and of other conventional hedge ratio estimation methodologies based on exponentially weighted moving averages, ordinary least squares and error correction, respectively. An empirical application using spot and futures data on the DJI, FTSE and DAX equity indices compares the in‐sample and out‐of‐sample hedging effectiveness of each approach in terms of risk minimization. The results show that the ARCD approach has the best performance, thus suggesting that forecasting higher moments is of practical importance for futures hedging. Copyright © 2012 John Wiley & Sons, Ltd.