Display of functional alphabeta single-chain T-cell receptor molecules on the surface of bacteriophage

The ability to display functional T-cell receptors (TCR) on the surface of bacteriophage could have numerous applications. For instance, TCR phage-display could be used to develop new strategies for isolating TCRs with unique specificity or it could be used to carry out mutagenesis studies on TCR molecules for analyzing their structure-function. We initially selected a TCR from the murine T-cell hybridoma, DO11.10, as our model system, and genetically engineered a three domain single-chain TCR (scTCR) linked to the gene p8 protein of the Escherichia coli bacteriophage fd. Immunoblotting studies revealed that (1) E. coli produced a soluble scTCR/p8 fusion protein and (2) the fusion protein was packaged by the phage. Cellular competition assays were performed to evaluate the functionality of the TCR and showed the DO11.10 TCR-bearing phage could significantly inhibit stimulation of DO11.10 T hybridoma cells by competing for binding to immobilized MHC/peptide IA(d)/OVA(323-339). Flow cytometric analysis was carried out to evaluate direct binding of DO11.10 TCR-bearing phage onto the surface of cells displaying either IAd containing irrelevant peptide or OVA peptide. The results revealed binding of DO11.10 TCR-bearing phage only on cells expressing IA(d) loaded with OVA peptide showing TCR fine specificity for peptide. To illustrate the generality of TCR phage-display, we also cloned and displayed on phage a second TCR which recognizes a peptide fragment from human tumor suppressor protein p53 restricted by HLA-A2. These findings demonstrate functional TCR can be displayed on bacteriophage potentially leading to the development of novel applications involving TCR phage-display.     

Development of materials specifications and emplacement procedures for backfilling nuclear fuel waste vaults

Atomic Energy of Canada Limited and Ontario Hydro are conducting a research program to assess the environmental impact and safety of the concept of disposal of nuclear fuel waste in an underground vault in plutonic rock of the Canadian Shield. The Vault Sealing Program, one of the components of the Nuclear Fuel Waste Management Program, is concerned with the development of materials specifications and emplacement procedures for backfilling the vault. Backfilling materials would surround the nuclear waste containers and fill all vault openings to minimize leaching and movement of radionuclides. This paper presents the procedure followed to select candidate backfill materials, the integration of mathematical modelling studies and physical testing for the definition of materials specifications, and the principal elements of the recommended handling and emplacement systems.     

Sex pheromone specificity as a reproductive isolating mechanism among the sibling speciesArchips argyrospilus andA. mortuanus and other sympatric tortricine moths (Lepidoptera: Tortricidae)

MaleArchips argyrospilus (Walker) were maximally attracted to a 60404200 admixture of (Z)-11-tetradecenyl, (E)-11-tetradecenyl, (Z)-9-tetradecenyl and dodecyl acetates. The identification of (Z)-9-tetradecenyl acetate, in addition to the other 3 components reported previously, is the first report of a 4-component pheromone system in moths.Archips mortuanus Kearfoot, a sibling species, was maximally attracted to a blend of the same components, but in a 90101 mix of the tetradecenyl acetates. Among a number of tortricine moths that co-occur on apples and other hosts in New York, British Columbia, and elsewhere, differences in diel rhythms of attraction and seasonal distribution are insufficient to maintain reproductive isolation. Although the attractant systems of these species often possess components in common, males are maximally attracted to a speciesspecific blend. In tortricine moths attraction specificity appears to be a paramount mechanism for species partitioning.     

多媒体教学中电视卡和视频的应用与实践

我所在的是一高职院校，比较注重对学生实践和动手能力的培养，在计算机专业教学中，《多媒体技术与应用》课程有一部分关于电视卡和数据压缩技术的介绍，但内容相对来说比较简单，而且实践的安排基本没有。而随着电脑的普及和电视卡价格的下降．电视卡的功能和应用越来越引起了学生们的关注和兴趣，所以在教学中适当增加这部分内容的讲解及实践既满足了学生的要求．保存下来的电视材料又为后面做视频处理做了很好的素材准备工作，而且为了保存这些庞大的视频文件，也为数据压缩技术的知识与实践提供了条件，使得以前这些枯燥乏味的知识变得丰富多彩起来。当然这些知识在实际生活中也是非常有用和有趣的。     

Photovoltaic processes in metal-semicrystalline silicon Schottky barriers and implications for grating solar cells

Experimental investigations of the photovoltaic properties of metal-silicon Schottky barriers are reported, in which edge collection of the photocurrent is dominant as in the majority-carrier grating solar cells proposed by Green. Both elemental metals and alloy Schottky electrodes, and both crystalline and semicrystalline cast silicon have been studied. The superposition principle for dark currents and photocurrents is shown unambiguously to be violated, and the effects of grain-boundary recombination and shunt resistance are identified. Limitations to the operation of these devices above the semiempirical limit of continuous Schottky barrier solar cells is seriously compromised by enhanced space-charge recombination current. This results from the large photocurrent densities for low contact area/active area ratios. The treatment of the space-charge recombination mechanism under optical illumination follows the normal Sah-Noyce-Shockley approach, but we introduce here a built-in “recombination potential” to encompass the non-zero recombination for short-circuit conditions.     

An improved approximation for the isolated transition in saturated magnetic recording

An improved analytic approximation for the isolated transition in saturated magnetic recording is developed. This, in turn, has led to a determination of the analytic form of the magnetization pattern which appears to be a more general representation of the traditional arctangent form.     

Toward a relationship perspective on aggression among schoolchildren: Integrating social cognitive and interdependence theories.

The traditional psychological approach of studying aggression among schoolchildren in terms of individual differences in aggression and in victimization has been valuable in identifying prevalence rates, risk, and consequences of involvement in aggression. However, it is argued that a focus on aggressor–victim relationships is warranted based on both conceptual and empirical grounds. Such a shift in focus requires modification and integration of existing theories of aggression, and this paper integrates social-cognitive theory and interdependence theory to suggest a new, interdependent social-cognitive theory of aggression. Specifically, this paper identifies points of overlap and different foci between these theories, and it illustrates their integration through a proposed model of the emergence of aggressor–victim interactions and relationships. The paper concludes that expanding consideration to include aggressor–victim relationships among schoolchildren offers considerable theoretical, empirical, and intervention opportunities. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Information foraging.

Information foraging theory is an approach to understanding how strategies and technologies for information seeking, gathering, and consumption are adapted to the flux of information in the environment. The theory assumes that people, when possible, will modify their strategies or the structure of the environment to maximize their rate of gaining valuable information. The theory is developed by (a) adaptation (rational) analysis of information foraging problems and (b) a detailed process model (adaptive control of thought in information foraging [ACT-IF]). The adaptation analysis develops (a) information patch models, which deal with time allocation and information filtering and enrichment activities in environments in which information is encountered in clusters; (b) information scent models, which address the identification of information value from proximal cues; and (c) information diet models, which address decisions about the selection and pursuit of information items. ACT-IF is instantiated as a production system model of people interacting with complex information technology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Imperfect pulse detection in neural nets with temporal codes

The statistics of pulsed neural networks employing temporal codes (time to rth pulse) are investigated under conditions of imperfect pulse detection. The mixed negative binomial distributions that result are broadened by the errors without changing their essential shapes. For r=1, the near-geometric distributions primarily exhibit decreasing effective rate parameters. These results are important in deciding between rate codes and temporal codes in noisy or otherwise imperfect artificial neural (or biological) environments.