基于分级遗传算法的结构损伤识别方法

提出了一种基于遗传算法的利用不完整振动数据识别结构损伤的新方法，该方法首先扩展不完整的振型并利用单元能量熵差比确定结构损伤的大致位置，然后采用二级搜索策略，借助遗传算法确定结构损伤的程度，数值计算结果表明，当可能的损伤区域较大时，本方法较直接搜索策略更能有效地确定结构损伤的程度。     

Partial deficiency of erythrocyte spectrin in hereditary spherocytosis

Hereditary spherocytosis (HS) is a common, clinically heterogeneous haemolytic anaemia in which the primary erythrocyte defect is believed to be some abnormality in the spectrin-actin membrane skeleton, leading to loss of surface membrane. Recessively inherited spectrin deficiency with extreme erythrocyte fragility and spherocytosis has been identified in certain mutant mice and two severely anaemic humans. Although suspected, deficiency of spectrin has not been demonstrated in less severe forms of human HS. We not report the quantitation of erythrocytes spectrin by radioimmunoassay. We found that normal erythrocytes contained 240,000 copies of spectrin heterodimer, whereas erythrocytes from 14 patients with a variety of types of HS were all partially deficient in spectrin (range 74,000-200,000 copies), the magnitude of the deficiency correlating with the severity of the disease. Spectrin deficiency of varying degrees is common in HS and probably represents the principal structural defect leading to loss of surface membrane.     

Human gamma-chain genes are rearranged in leukaemic T cells and map to the short arm of chromosome 7

Three gene families that rearrange during the somatic development of T cells have been identified in the murine genome. Two of these gene families (alpha and beta) encode subunits of the antigen-specific T-cell receptor and are also present in the human genome. The third gene family, designated here as the gamma-chain gene family, is rearranged in murine cytolytic T cells but not in most helper T cells. Here we present evidence that the human genome also contains gamma-chain genes that undergo somatic rearrangement in leukaemia-derived T cells. Murine gamma-chain genes appear to be encoded in gene segments that are analogous to the immunoglobulin gene variable, constant and joining segments. There are two closely related constant-region gene segments in the human genome. One of the constant-region genes is deleted in all three T-cell leukaemias that we have studied. The two constant-region gamma-chain genes reside on the short arm of chromosome 7 (7p15); this region is involved in chromosomal rearrangements identified in T cells from individuals with the immunodeficiency syndrome ataxia telangiectasia and observed only rarely in routine cytogenetic analyses of normal individuals. This region is also a secondary site of beta-chain gene hybridization.     

基于免疫网络理论的TCSC与PSS协调控制

电力系统稳定器(PSS)和可控串联补偿器(TCSC)被广泛用于电力系统的稳定控制,多个控制器之间的交互作用会影响彼此的控制效果.本文介绍了生物免疫系统中不同类型的抗体协调合作,共同清除抗原的协调机理.提出了基于免疫网络理论的协调控制方法,用于在线协调控制多个阻尼控制器,抑制电力系统的功率振荡.以装有多个PSS和TCSC的系统为例,对多个控制器进行在线协调阻尼控制.仿真结果表明该方法能够缩短抑制振荡所需的时间,具有有效性和鲁棒性.     

Buccal floor of reptiles, a summary

A general survey of the information presently available on the osteology and myology of the hyobranchial apparatus. Included in the survey are examples of the hyobranchial skeleton of the major groups of reptiles, including the Chelonia, Crocodilia, Rhynchocephalia, and Squamata. The myology treats the muscles directly associated with the hyoid as well as those associated with the functioning of the apparatus, but not arising or inserted directly on or from the hyoid. The innervation of the hyobranchial apparatus is reviewed and briefly discussed based on the information available in a few major studies. An attempt is made to cite all pertinent literature references, and in Tables 1 and 2 the references to basic areas are indicated. Twenty - nine plates and figures are included, some of which represent original research.     

Clark's Nutcrackers harvest sugar pine seeds from cones

This is the first report of Clark’s Nutcrackers ( Nucifraga columbiana ) harvesting seeds from the cones of sugar pine ( Pinus lambertiana ), based on observations over several years in Crater Lake National Park, Oregon. The harvesting period in late September corresponded to peak cone-opening dates. Nutcrackers placed harvested seeds in their throat pouches, a behavior associated with seed caching.     

Attributes associated with probability of infestation by the pi?on ips, Ips confusus (Coleoptera: Scolytidae), in pi?on pine, Pinus edulis

We examined attributes of pi?on pine ( Pinus edulis ) associated with the probability of infestation by pi?on ips ( Ips confuses ) in an outbreak in the Coconino National Forest, Arizona. We used data collected from 87 plots, 59 infested and 28 uninfested, and a logistic regression approach to estimate the probability of infestation based on plot and tree-level attributes. Pi?on pine stand density index was a good predictor of the likelihood of infestation by pi?on ips at the plot level, and a cross-validation analysis confirmed that the model correctly classified 82% of the cases. Diameter at root collar and pi?on dwarf mistletoe infestation level were good predictors of individual tree infestation, and a cross-validation analysis indicated that the model correctly classified 72% of the cases. Results suggest that the occurrence of pi?on ips infestations may be related to stress factors associated with increased stocking and pi?on dwarf mistletoe infestations.     

Effects of habitat fragmentation and differing mobility on the population structures of a Great Basin dragonfly ( Sympetrum corruptum ) and damselfly ( Enallagma carunculatum )

The population structure of 2 Great Basin odonate species was assessed using protein electrophoresis. Analyses included 7 populations of Sympetrum corruptum (suborder Anisoptera), a migratory and highly mobile dragonfly, and 8 populations of Enallagma carunculatum (suborder Zygoptera), a weak flier that is not known to migrate far from natal water sources. Though we expected the damselfly ( E. carunculatum ) to show greater genetic isolation than the dragonfly ( S. corruptum ), both species apparently had high levels of gene flow (theta = 0.0604 for S. corruptum , theta = 0.0485 for E. carunculatum ) and showed no evidence for isolation by distance. These results suggest that both species are highly vagile and that the most important factors affecting population structure of these odonates may be ecological conditions such as habitat patchiness and the ephemerality of water sources.     

Vegetation parameters for judging the quality of reclamation on coal mine spoils in the Southwest

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