Prevention of T cell anergy by signaling through the gamma c chain of the IL-2 receptor

When stimulated through their antigen receptor without requisite costimulation, T cells enter a state of antigen-specific unresponsiveness termed anergy. In this study, signaling through the common gamma chain of the interleukin-2 (IL-2), IL-4, and IL-7 receptors in the presence of antigen was found to be sufficient to prevent the induction of anergy. After culture with IL-2, IL-4, or IL-7, Jak3 kinase was tyrosine-phosphorylated, which correlated with the prevention of anergy. Therefore, a signal through the common gamma chain may regulate the decision of T cells to either clonally expand or enter a state of anergy.     

Manipulation of avoidance behavior as a function of increased or decreased demand on repeated behavioral tests.

5 groups of 15 female undergraduates reporting fear of snakes participated in 2 behavioral avoidance tests employing a snake as the target object. 4 groups were first tested under low demand for approach and then under the same conditions or under 1 of 3 conditions of demand increase, mediated by instructions, mode of administration, or both. The 5th group was tested under high, then low demand. Ss first tested under low demand showed significantly more fear than those first tested under high demand. In addition, Ss in the demand-increase groups showed significant increases in approach at the 2nd behavior avoidance test, while Ss in the demand-decrease group showed a significant reduction in approach. Ss in the repeated-measure control group showed no significant changes. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of defects on the fatigue crack initiation process in two p/m superalloys: part i. fatigue origins

Two high strength P/M nickel-base superalloys, AF-115 and AF2-1DA, with different defect populations, were tested to determine the effect of preexisting defects on the fatigue crack initiation process. Strain controlled continuous cycle fatigue tests were performed at room and at elevated temperature; these were followed by fractographic examination to characterize both the location and character of the fatigue origins. In most cases, particularly at elevated temperature, the initiation process was associated with a large pre-existing defect, either a pore or a nonmetallic inclusion. There was also a change in the location of the crack that caused failure as the strain range varied: at high strain ranges initiation occurred at or near the specimen’s surface, while at the lower strain ranges the failure originated in the specimen’s interior. The initiation mode for both alloys at room temperature was different than at elevated temperature. At room temperature, Stage I crystallographic cracking at or near the surface dominated the process in all strain range regimes. This difference was attributed, in part, to the differences in deformation mode for nickel-base superalloys at room and elevated temperature. Formerly with Metals and Ceramics Division, Air Force Materials Laboratory, Wright-Patterson AFB, OH.     

The power of inequality semijoins

Semijoin is a relational operator used in many relational query processing algorithms. Semijoins can be used to “reduce” the database by delimitting portions of the database that contain data relevant to a given query. For some queries, there exist sequences of semijoins that delimit the exact portions of the database needed to answer the query. Such sequences are called full reducers.

This paper considers a class of queries called natural inequality queries (NI queries), and characterizes a subclass for which full reducers exist. We also present an efficient algorithm that decides whether an NI query lies within this subclass, and constructs a full reducer for the query. The NI queries are a subset of the aggregate-free, conjunctive queries of QUEL, and permit join clauses to include <, , =, , >.     

Computers and the 16th-century Chanson a pilot project at the University of Chicago

Conclusions One cardinal principle guided our evaluation of the data provided for us by the computer: never to be deluded into believing that the computer was in any way capable of analyzing a piece of music. Rather, we used the information made available by the computer as a means of substantiating or explaining the insights into a given composition that we gained by means of a direct confrontation with the music. In this way, the data supplied by the computer proved to be very useful in explaining why a particular portion of a chanson generates a sense of tension, while another section of the same piece creates a feeling of rest. Similarly, the electronically derived information was particularly helpful in setting up stylistic profiles of the various composers whose chansons were included in our sampling. In fact, the computer output was instrumental in helping to settle more than one problem of conflicting attributions, largely on the basis of these stylistic profiles. Like any other computerized process, our program elicited from the computer no analytical operation that could not have been done without the assistance of the computer. Very little precise measurement has been done in the analysis of the music of the Renaissance, however, and for good reason: the compilation of statistical data of the type we have described takes so much time that it can be considered feasible only with mechanical assistance. The ability we gained to apply to the chanson repertory a somewhat more precise system of analytical measurement was the most encouraging aspect of the pilot project. candidate for the Ph.D. in Physics     

The role of retained austenite in stress corrosion cracking of steels

Metallurgical and Materials Transactions A - The ability of retained austenite to affect stress corrosion cracking susceptibility has been examined in two steels, containing mechanically stable and...     

Field and laboratory aging of polymeric distribution cableterminations. I. Field aging

This, two-part paper, describes the results of a research project aimed at understanding the magnitude of aging of polymeric cable terminations used in distribution. The termination types evaluated are currently used; hence, they have satisfied IEEE Standard 48. This standard does not address the issue of aging. Terminations made from 3 different polymer families and porcelain were evaluated. Presented in Part I, are the results of field aging from 5 outdoor sites in the USA over a 3 year period; and in Part II, results from accelerated aging fog chamber laboratory tests. The results from field aging show that only minor changes were produced. Some differences were observed in the electrical performance of formulations within the same polymer family, and among different polymer families. However, it was concluded that the performance of the terminations evaluated would not be compromised by aging produced changes in the weathershed housing     

Identification of the inertia matrix of a rotating body based on errors‐in‐variables models

This paper proposes a procedure for identifying the inertia matrix of a rotating body. The procedure based on Euler's equation governing rotational motion assumes errors‐in‐variables models in which all measurements, torque as well as angular velocities, are corrupted by noises. In order for consistent estimation, we introduce an extended linear regression model by augmenting the regressors with constants and the parameters with noise‐contributed terms. A transformation, based on low‐pass filtering, of the extended model cancels out angular acceleration terms in the regressors. Applying the method of least correlation to the model identifies the elements of the inertia matrix. Analysis shows that the estimates converge to the true parameters as the number of samples increases to infinity. Monte Carlo simulations demonstrate the performance of the algorithm and support the analytical consistency. Copyright © 2009 John Wiley & Sons, Ltd.