Creep deformation structural analysis using an efficient numerical algorithm

This paper presents a fast numerical algorithm for the implementation of material models for creep into finite element codes. First, an overview of existing algorithms for transient and steady-state creep is given. Next, a new formulation is presented which reduces the constitutive integration to the solution of a scalar non-linear algebraic equation. A solution is shown to exist without the need for subincrementation. Details of the numerical algorithm are then discussed. The paper closes with several numerical examples which illustrate the speed, robustness and accuracy of the proposed procedure as implemented in the Lawrence Livermore National Laboratory finite element codes NIKE2D and NIKE3D.     

Postintegration methods for numerical integration of non-linear dynamic equations of motion

The paper presents a family of methods with postintegration, for numerical integration of non-linear dynamic equations of motion of discrete systems. Both explicit and implicit algorithms of these methods are conditionally stable, but can give solutions of accuracy of a few orders higher than the known methods with preintegration, corresponding to them. A general analysis of stability and accuracy of single-step methods is carried out. The postintegration methods have been tested on a single-degree-of-freedom non-linear system.     

Psychiatric evaluation in accordance with the transsexualism regulation. An experience-based plea for guidelines and against arbitrary bias

Today patients want to change their Christian names not so much for social support but in order to obtain sex change operations. For this reason among others we caution against casual and careless evaluations and plead for conscientiousness and thoroughness. The spectrum of 16 evaluation cases in the year 1995 is presented. Following this and looking for guiding principles, the most important aspects are discussed: the dilatable frame of the written law, the examiner's diagnostic process, the duty of being well informed, reconstruction of development as the first goal of examination, real-life self-testing and therapy, the obligation to report one's own findings, change of Christian name and indication of operation, evaluation for gender changing, problems of the judge-expert relationship and of future development.     

A new eicosapentaenoic acid formed from arachidonic acid in the coralline red algaeBossiella orbigniana

Aqueous extracts of the coralline red algaeBossiella orbigniana have been shown to catalyze the enzymatic oxidation of arachidonic acid to a previously unreported ω6 eicosapentaenoic acid product. This unique fatty acid contains a conjugated tetraene with absorption maxima at 293, 306, and 321 nm, and was identified by spectral methods as 5(Z),8(Z),10(E),12(E),14(Z)-eicosapentaenoic acid. The compound was given the trivial name bosseopentaenoic acid. Under experimental conditions, production of bosseopentaenoic acid was linear up to 2 hr and dioxygen was consumed. Bosseopentaenoic acid, along with several other conjugated tetraenes, was also present in the algae endogenously as revealed by a comparison of the ultraviolet (UV) spectra and the high-performance liquid chromatographic (HPLC) pattern of the purified product and the organic extract ofBossiella.     

Introduction to the special series: HIV infection among drug abusers.

Drug users are particularly at risk for contracting the human immunodeficiency virus and serve as a major mechanism for spreading the virus to other sectors of the population. As a result drug abuse treatment and potential behavioral change strategies are primary public health issues. The purpose of this article is to review the contributions included in this special edition, which represent an effort to describe the most current thinking in the field with a blend of theoretical, review, and empirical articles. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceived equity, motivation, and final-offer arbitration in major league baseball.

Final-offer salary arbitration in major league baseball offers a unique institutional arrangement that creates a naturally occurring, non-equivalent-groups, repeated measures research design. The structural arrangements allow for examination of anticipatory expectancy effects and assessment of behavioral responses consistent with equity theory predictions. In addition, equity theory can be tested without the methodological problems inherent in defining the referent other. Performance and mobility were examined for major league baseball position players who won and lost their arbitration hearings. Prearbitration performance significantly predicted arbitration outcome. A significant relationship was noted between losing arbitration and postarbitration performance decline. Losers were significantly more likely to change teams and leave major league baseball. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional cues in chronic schizophrenia: Abnormal disengagement of attention.

M. I. Possner's 1980 reaction time (RT) paradigm was used to examine the engagement and disengagement operations of visual selective attention in patients with schizophrenia. In the 1st experiment 14 medicated, chronic schizophrenic Ss (diagnosed by criteria of the Diagnostic and Statistical Manual of Mental Disorders [DSM-I]), and 15 age-matched normal and control Ss made a speeded response to a target preceded by a valid, and invalid, or no cue. Control Ss showed the expected advantage and disadvantage in RT for valid and invalid cues, which suggests intact engagement and disengagement operations. For schizophrenic Ss, valid cues also enhanced RT, but invalid cues did not slow RT. Similar results were found in the 2nd experiment. The failure of unpredictable, invalid cues to inhibit RT in chronic schizophrenia may be related to an abnormality in the disengagement operation of selective attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Depletion of cortical norepinephrine in rats by 6-hydroxydopamine does not impair performance of a delayed-nonmatching-to-sample task.

Rats were trained on a spatial delayed-nonmatching-to-sample (DNMTS) task, matched for performance, and randomly assigned to treatment with dorsal noradrenergic bundle injections of either 6-hydroxydopamine, to deplete cortical norepinephrine (NE), or vehicle, to control for the effects of surgery. After recovery, there were no significant differences between the groups when retrained on the DNMTS task at retention intervals (RIs) from 0.1 to 15.0 sec. Furthermore, no differences were observed when rats were trained at a 6.0-sec RI filled with distracting stimuli or when dummy information runs were added to increase proactive interference. These results demonstrate that depletion of cortical NE cannot account for the DNMTS performance deficits observed in rats recovered from pyrithiamine-induced thiamine deficiency (R. L. Knoth and R. G. Mair, 1991; J. K. Robinson and Mair, 1992). (PsycINFO Database Record (c) 2010 APA, all rights reserved)