Modeling of Dislocation

A physically-based dislocation theory of plasticity is derived within an extended continuum mechanical context. Thermodynamically consistent flow rules at the grain boundaries are derived. With an analytical solution of a three-phase periodic laminate, dislocation pile-up at grain boundaries and dislocation transmission through the grain boundaries are investigated. For the finite element implementations, numerically efficient approaches are introduced based on accumulated field variables

Student Characteristics And Student Evaluations Of College Teaching: A Within-class Analysis

Research examining the relation between student characteristics and individual student evaluations of college teaching has often pooled data across classes, thereby mixing between- and within-class variability and allowing the possibility of obscuring differential within-class relationships. To avoid these difficulties, the present study examined associations between student characteristics and evaluations of teaching within separate classes. Each of 278 students from six undergraduate classes completed a questionnaire assessing perceptions of instructional effectiveness and teacher personality, as well as their own personality, interest in the course, gender, university level, grades, perceptions of amount learned, likelihood of future course enrollment, and attitude toward university instruction. Averaged across classes, individual student evaluations were found to correlate with: other subjective indices of teaching effectiveness (ratings of amount learned and likelihood of future enrollment); perceived teacher nurturance, achievement, orderliness, and neuroticism (negatively related); perceived positive student-teacher dissimilarity in nurturance, extraversion, achievement, orderliness, and neuroticism; interest in the course; university level; and attitudes toward university instruction. Averaged across classes, however, individual student evaluations failed to correlate significantly with: perceived student-teacher similarity in personality; students\u27 university grade average; course grades; perceived grading leniency; gender; area of major; or student personality. The relationship between student personality and evaluations, however, was found to differ across classes for 3 of 5 dimensions, demonstrating the utility of within-class analyses. Moreover, these differences were found to be related to differences between classes in mean perceptions of relevant teacher personality traits. Certain types of students seemed to find certain types of instructors to be most effective; whereas other types of students seemed to find other types of instructors to be most effective. Findings were interpreted as evidence for the validity of student ratings of instructional effectiveness and discussed in terms of understanding and improving college instruction

Interleukin-1 blockade in recently decompensated systolic heart failure: study design of the recently decompensated heart failure anakinra response trial (RED-HART)

Heart Failure (HF) is a clinical syndrome characterized by dyspnea, fatigue, and poor exercise capacity due to impaired cardiac function. The incidence of HF is increasing and represents the leading cause of hospitalization in the United States among patients > 65 years of age. Neurohormonal blockade has proven to reduce morbidity and mortality; however the persistent toll of HF demonstrates the urgent need to continue to develop novel drugs that target other pathophysiological paradigms. The presence of inflammation in cardiovascular disease has been well-established and interleukin-1 (IL-1), the prototypical proinflammatory agent, has been shown in preclinical animal models to induce cardiac dysfunction. The current study will investigate the role of IL-1 as an inflammatory mediator of HF progression and investigate whether IL-1 blockade with anakinra, recombinant human IL-1 receptor antagonist, improves aerobic exercise performance in patients with recently decompensated systolic HF. This study will be composed of 3 treatment arms (20 patients each): 1) anakinra 100mg daily for 12 weeks; 2) anakinra 100mg daily for 2 weeks followed by placebo for 10 weeks; or 3) placebo for 12 weeks. All patients will be followed for at least 24 weeks. The co-primary endpoints will be placebo-corrected interval changes in peak oxygen consumption (VO2) and ventilatory efficiency (VE/VCO2 slope) measured by Cardiopulmonary Exercise Testing (CPX) after 2 weeks of anakinra treatment. Secondary endpoints will include interval changes in 1) CPX variables at 4, 12 and 24 weeks; 2) echocardiographic measures of cardiac dimension/function; 3) quality of life assessments; 4) inflammatory biomarkers; and 5) clinical outcome including days alive outside of the hospital and survival free of re-hospitalization for HF. The RED-HART study will be the first study to address the potential benefits of IL-1 blockade on aerobic exercise performance in patients with recently decompensated HF