一个新的核酸序列比对算法及其在序列全局比对中的应用

目前在序列比对中所广泛使用的动态规划算法,虽然能达到最优比对结果,但却由于具有高计算复杂度O(N_2)而极大地降低了计算效率。将多阶段动态规划决策算法用于两两序列比对并用Visual BASIC编程实现,结果发现该新算法在将计算复杂度减小到O(N)的同时,也能够获得较为理想的计算精度,预期将在序列全局比对中起重要作用。     

Colonialism and ethnicity: A theory and comparative case study

This article explores Arab American "invisibility" as a central theme in the historical narrative of Arab immigrants and their descendants in North America. "Invisibility" is primarily addressed in terms of Arab Americans' paradoxical positioning within the US racial/ethnic classification system. The article argues that four central paradoxes shape Arab American identity. The first paradox is that Arab Americans are a complex, diverse community, but are represented as a monolith in popular North American media images. The second paradox is that Arab Americans are simultaneously racialized as whites and as non-whites. The third paradox is that Arab Americans are racialized according to religion (Islam) rather than biology (phenotype). The fourth paradox involves the intersection between religious forms of identity that Arab immigrants bring to the US and racial forms of identity that structure US society. Overall, the article claims that each paradox of Arab American identity reinforces the difficulties associated in classifying this population.     

Seed ecology of dust seeds in situ: a new study technique and its application in terrestrial orchids

A method is described by which seeds of terrestrial orchids are sown and retrieved in the field under almost natural conditions. For the first time it is possible to conduct a quantitative study of orchid germination in situ and observe seasonal growth and mortality of seedlings. The technique has also enabled us to investigate the relation between the site where the seeds are sown, the availability of an appropriate fungus to infect the seeds, and seedling establishment in the soil. Five local species were studied. Corallorhiza odontorhiza, Goodyera pubescens, and Galearis spectabilis all began to germinate in May–June, after 23-30 weeks in the soil. These species differed in their dependency on infection at germination time, but none of the seedlings developed beyond the point of rupturing the testa except when infected. Seeds of Liparis lilifolia and Tipularia discolor did not germinate within the first 12 months of the experiment. The implications and potential uses of this field sowing technique for further studies and for other kinds of minute seeds are discussed.     

A new technique for skin grafting in avascular areas: a preliminary report.

A 3 X 3 cm, buried, split-skin graft will survive on an avascular bed if it is temporarily covered with a skin flap. Four cases of secondary ear reconstruction are presented, in which this technique was effectively used.     

High- and multi-frequency EPR study of Mn12: A new technique for studying new objects

In this paper, the principles and constituents of the wide band high-frequency and high-field EPR spectrometer developed at GHMFL are presented. The interest of multifrequency EPR is then illustrated with the study performed along the years on Mn12 single-molecule magnets. In particular, the progress realized on the experimental set-up, its use and on the interpretation of the spectra are underlined, resulting in the detailed understanding of the origin of the magnetic anisotropy and in the establishment of magneto-structural correlations.     

A new technique of vaginal reconstruction using neurovascular pudendal-thigh flaps: a preliminary report

The blood supply to the skin of the perineum, medial groin, and upper thigh was studied in fresh female cadavers. The pudendal-thigh flap was designed as a result to reconstruct the vagina. The flaps are raised bilaterally in the groin crease just lateral to the labia majora and then are transposed toward the midline and sutured together to form a skin-lined cul-de-sac which opens at the introitus. The technique has been used successfully in three patients to reconstruct the vagina. The first patient, an adult, was reconstructed after total pelvic exenteration for malignancy, while two children had reconstructions for congenital vaginal anomalies. This technique is superior to currently available methods because it is simple and reliable. No stents or dilators are needed. It is safe technique without complications in our hands. The reconstructed vagina has a natural angle for intercourse and is sensate. The donor scars in the groin are well hidden.     

Pancreatic duct occlusion in the rat: report and assessment of a new technique

Temporary reduction of the exocrine pancreatic secretion may be desirable in various experimental models. In the rat this can be achieved by obstructing the connection between the pancreas and the duodenum. A new, simple technique of pancreatic duct occlusion using metal hemostatic clips is described. The reduction of secretion produced by the procedure was assessed by measuring duodenal protein, amylase, and trypsin during stimulation with cholecystokinin. Stimulated duodenal amylase activity 1 and 4 weeks following duct occlusion was reduced by approximately 80% compared with sham-operated controls, whereas proteolytic activity was reduced by 96 and 60%, respectively. The magnitude and duration of pancreatic insufficiency achieved by this technique is equivalent to that achieved with more complicated methods.     

A new method for 2D gel spot alignment: application to the analysis of large sample sets in clinical proteomics

Background  

In current comparative proteomics studies, the large number of images generated by 2D gels is currently compared using spot matching algorithms. Unfortunately, differences in gel migration and sample variability make efficient spot alignment very difficult to obtain, and, as consequence most of the software alignments return noisy gel matching which needs to be manually adjusted by the user.     

The ethnic question in an environment of insecurity: the Kurds in Turkey

This article examines the effect that a poor structural context, what we term an "environment of insecurity", has on the Kurdish ethnic nationalist mobilization in Turkey. The empirical evidence for this analysis is based on data from the 1993 Turkish Demographic and Health Survey [TDHS]. The data provide, to the best of our knowledge, the first reliable and representative figures on the situation of Kurds in Turkey. Our key claim is that the Kurdish population in Turkey is relatively much worse off than the Turkish population in the country. This claim is strongly supported by the data. Many other factors also account for the ethnic nationalist mobilization, but we argue that the Turkish Kurds' environment of insecurity, materially and non-materially, stands out as a key package of both causal and intermediate variables behind the ethnic revival.     

白血病小鼠模型的建立与应用进展

白血病又被称为"血癌",其发病的根本特征是白血病细胞在骨髓及其他造血组织中呈恶性、无限制地增生,浸润全身各组织和脏器,产生不同症状,使患者易发生严重的感染或继发性的败血症、引起出血、肠功能衰竭、高尿酸血症等,严重威胁到患者的生命。因此白血病治疗的研究至关重要。利用实验动物进行各种疾病、药物疗效实验的研究,是医药领域发展的一个重要方面。对于白血病的研究,小鼠在生物学、遗传学、造血系统等方面与人类相似,因此是较为理想的动物白血病模型。本文对近五年来国内外研究常用的小鼠白血病模型进行综述。     

Review article: The Aboriginal experience: A problem of interpretation

Raymond Evans, Kay Saunders and Kathryn Cronin, RACE RELATIONS IN COLONIAL QUEENSLAND: A HISTORY OF EXCLUSION, EXPLOITATION AND EXTERMINATION, St. Lucia: University of Queensland Press, 1988 (fp.1975), 450 pp., $26.95.

Henry Reynolds, WITH THE WHITE PEOPLE: THE CRUCIAL ROLE OF ABORIGINES IN THE EXPLOITATION AND DEVELOPMENT OF AUSTRALIA, Ringwood: Penguin Books, 1990, 288 pp., $16.99.

Jeff Collmann, FRINGE‐DWELLERS AND WELFARE: THE ABORIGINAL RESPONSE TO BUREAUCRACY, St. Lucia: University of Queensland Press, 1988, 276 pp., $29.95.     

A comparative study of metric and non-metric traits in a series of modern crania

The purpose of this study is to question the utility of non-metric traits as predictors of age, race, and sex by comparing a group of non-metric variables with a group of metric variables. Twelve metric variables and 15 nonmetric variables were scored on 317 crania from the Terry Collection at the U. S. National Museum, and later statistically evaluated with a number of multivariate analysis programs and a stepwise discriminant program. The metric variables were found to be significant sex and race discriminators, where-as the non-metric variables were non-significant. The non-metric variables were found to be better age discriminators than the metric variables, even though neither could be classified as highly significant. It was concluded that non-metric traits by themselves have very little discriminatory value and should be used instead to supplement other osteological measurements and observations.     

Culture of cells in beem capsules: A new technique for electron microscopic study of monolayer cultures

Summary A method is described for the monolayer cultivation of primary cell suspensions and established cell lines directly in carbon-coated BEEM capsules. BEEM capsules are routinely employed by electron microscopists in tissue embedding procedures; growing monolayer cultures directly on the lids of inverted BEEM capsules presents the obvious advantage of maintaining cell to cell to substratum contacts with a minimum of stress and damage in the preparative steps for electron microscopy. This work was supported by grant AM 17631 from the National Institute of Arthritis, Metabolism, and Digestive Diseases, grant CA 11339 from the National Cancer Institute. The Jackson Laboratory is fully accredited by the American Association for Accreditation of Laboratory Animal Care.     

Innovativeness as an emergent property: a new alignment of comparative and experimental research on animal innovation

Innovation and creativity are key defining features of human societies. As we face the global challenges of the twenty-first century, they are also facets upon which we must become increasingly reliant. But what makes Homo sapiens so innovative and where does our high innovation propensity come from? Comparative research on innovativeness in non-human animals allows us to peer back through evolutionary time and investigate the ecological factors that drove the evolution of innovativeness, whereas experimental research identifies and manipulates underpinning creative processes. In commenting on the present theme issue, I highlight the controversies that have typified this research field and show how a paradigmatic shift in our thinking about innovativeness will contribute to resolving these tensions. In the past decade, innovativeness has been considered by many as a trait, a direct product of cognition, and a direct target of selection. The evidence I review here suggests that innovativeness will be hereon viewed as one component, or even an emergent property of a larger array of traits, which have evolved to deal with environmental variation. I illustrate how research should capitalize on taxonomic diversity to unravel the full range of psychological processes that underpin innovativeness in non-human animals.     

微阵列技术在糖组学研究中的应用

糖组学是研究糖链组成及其功能的一门新学科,近年来备受关注.目前糖组学的研究还处于起步阶段,阻碍糖组学迅速发展的主要原因是糖链本身结构的复杂性和研究技术的限制.微阵列技术作为一种快速、高效、高通量、微型化和自动化的分析技术,已经在基因组学和蛋白质组学的研究中发挥了重要的作用,将其应用于糖组学研究必将推动糖组学的发展.     

The pipette method: A new rapid technique for chromosome analysis in prenatal diagnosis

Summary A new method has been developed to abridge the time between amniocentesis and chromosome analysis in prenatal diagnosis. With this method cells in metaphase are separated from the clones by a micropipette with the help of a micromanipulator and then prepared.