Fractography of unidirectional graphite-epoxy as a function of moisture,temperature and specimen quality

The tensile failure surfaces of (0°)₈ T300/5208 graphite-epoxy specimens were examined using both optical and scanning electron microscopy. Fractography was used to determine how moisture content and temperature as well as specimen preparation technique, prepreg batch and cure condition affected the failure mode. A distinctive low-energy failure morphology was found in defective specimens and also in those whose edges were poorly prepared. This morphology was predominant in failures at elevated temperature or moisture content for specimens which had been made from one suspect batch of prepreg. This finding combined with unusual end-tab failures from such specimens indicated that this batch was indeed defective, but that such defective batches could in the future be identified by tests under hot, wet conditions. For specimens made from good prepreg, temperature or moisture appeared to decrease flaw sensitivity and thus increase strength, even though moisture also seemed to increase interfacial debonding between filament and matrix. When combined, moisture and temperature appeared to degrade performance by increasing interfacial debonding and making the epoxy matrix more prone to fracture.     

A NEW PARADIGM FOR IS

An Is paradigm shift will create problems of adjustment and new opportunities for IS professionals. To function effectively in this new world, current and future IS professionals must acquire new knowledge and skills. This will not be easy to accomplish and will require the joint effort of both industry and academia. However, the payoffs from such human investments will be enormous. The existence of a cadre of capable IS professionals who can intelligently and effectively apply emerging information technologies not only affects the success of individual organizations but improves the competitiveness of our nation.     

De novo fatty acid synthesis and fatty acid elongation catalyzed by subcellular fractions from hog and human aorta

De novo synthesis and mitochondrial elongation of fatty acids have been demonstrated in subcellular fractions from hog and human aorta. Microsomal fatty acid elongation has been shown in hog aorta. The activity catalyzing the formation of fatty acids from acetyl and malonyl CoA was associated with a high molecular weight complex in the 6×10⁶g×min supernatant fraction. The principal product was palmitic acid. Some myristic and stearic acids were also formed. One elongation system was associated with protein which sedimented between 4500 g×min and 150,000 g×min. It used acetyl CoA but not malonyl CoA, and NADH was the preferred reducing agent. Radioactivity from acetyl CoA was incorporated into many fatty acids. In hog aorta a second elongation system was found associated with protein which sedimented at 6×10⁶ g×min. It used malonyl CoA preferentially as substrate and either NADH or NADPH as reducing agent.     

Association between socioeconomic status and metabolic syndrome in women: Testing the reserve capacity model.

Objective: Low socioeconomic status (SES) environments may impede the development of a bank of resources, labeled reserve capacity, and may also be stressful, thereby depleting available reserves. In consequence, lower SES persons may experience more negative emotions, leading to adverse health consequences. The authors tested the reserve capacity model in relation to the metabolic syndrome. Design: There were 401 initially healthy women who followed longitudinally for 12 years. Self-reported characteristics, stressors, and cardiovascular risk factors were measured repeatedly. Structural equation modeling was used to evaluate hypothesized relationships. Main Outcome Measure: Metabolic syndrome factor. Results: Confirmatory factor analysis verified reserve capacity as the aggregate of optimism, self-esteem, and social support, and negative emotion as the aggregate of depressive symptoms, anger, and tension. Structural equation modeling showed two pathways to the metabolic syndrome factor, (χ2(59) = 111.729, p ldf = 1.894; CFI = .956; RMSEA = .047): direct from low SES to the metabolic syndrome factor (B = -0.19, t = -3.24, p = .001); and indirect, from low SES to low reserve capacity to high negative emotions to the metabolic syndrome factor (B = -0.024, t = -2.05, p = .04). Conclusion: Low SES may increase risk for metabolic syndrome, in part, through reserve capacity and negative emotions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What's wrong with believing in repression?: A review for legal professionals.

Some courts in recent years have tarnished their credibility by willingly and blindly adopting the theory of repressed memory. Such acceptance can destroy the reputations of falsely accused individuals, and, by failing to pay due attention to scientific evidence, gives credence to pseudoscience and demeans the scientific method. This paper was written to inform judges and attorneys about the relevant evidence, which shows that: (a) the concepts of repressed and recovered memory are not generally accepted in the psychological and psychiatric community; (b) the studies cited to support these concepts reveal significant flaws; (c) much empirical evidence has been accumulated against the theory of repression; (d) the studies using the best methodology offer the least support for the repression hypothesis; and (e) there is no evidence that recovered memories accurately reveal the specifics of long-ago events. Repressed- and recovered-memory theory is not supported by science. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Family conflict and intragroup marginalization as predictors of acculturative stress in Latino college students.

This study examined the impact of family conflict and intragroup marginalization on acculturative stress in 188 bicultural Latino college students. Results showed that low parental income, low acculturation, perceived family conflict, and perceived intragroup marginalization were related to higher acculturative stress for participants. Intragroup marginalization accounted for a statistically significant proportion of the variance in acculturative stress after all variables were controlled. The findings emphasize the need to recognize culture-specific stressors of college students. Implications for mental health providers are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Universal intervention effects on substance use among young adults mediated by delayed adolescent substance initiation.

In this article, the authors examine whether delayed substance initiation during adolescence, achieved through universal family-focused interventions conducted in middle school, can reduce problematic substance use during young adulthood. Sixth-grade students enrolled in 33 rural midwestern schools and their families were randomly assigned to 3 experimental conditions. Self-report questionnaires provided data at 7 time points for the Iowa Strengthening Families Program (ISFP), Preparing for the Drug Free Years (PDFY), and control groups through young adulthood. Five young adult substance frequency measures (drunkenness, alcohol-related problems, cigarettes, illicit drugs, and polysubstance use) were modeled as distal outcomes affected by the average level and rate of increase in substance initiation across the adolescent years in latent growth curve analyses. Results show that the models fit the data and that they were robust across outcomes and interventions, with more robust effects found for ISFP. The addition of direct intervention effects on young adult outcomes was not supported, suggesting long-term effects were primarily indirect. Relative reduction rates were calculated to quantify intervention-control differences on the estimated proportion of young adults indicating problematic substance use; they ranged from 19% to 31% for ISFP and from 9% to 16% for PDFY. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotional and cardiovascular sensitization to daily stress following childhood parental loss.

Adverse childhood events can influence the development of emotional and physiological self-regulatory abilities, with significant consequences for vulnerability to psychological and physical illness. This study evaluated stress sensitization and inoculation models of the impact of early parental death on stress exposure and reactivity in late adolescence/young adulthood. Ambulatory blood pressure (BP) and diary reports of minor stress were collected every 30 min during waking hours over a 24-hr period from 91 late adolescents/young adults (43 early bereaved, 48 nonbereaved). Across the sample, minor stressors were associated with elevated BP and negative affect. The bereaved group had lower BP than did the nonbereaved group. Within the bereaved group, higher perceived caring from the surviving parent was associated with fewer reports of minor stress and lower stress-related negative affect. Higher perceived parental caring during childhood was associated with lower BP across the sample and more frequent hassles in the nonbereaved group. Findings support both the stress inoculation and sensitization models, suggesting that childhood parental loss and parental caring exert important influences on children's development of stress sensitivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Defining a complex intervention: The development of demarcation criteria for “meditation”.

The authors used a 5-round Delphi study with a panel of 7 experts in meditation research to achieve agreement on a set of criteria for a working definition of “meditation” for use in a comprehensive systematic review of the therapeutic use of meditation. Participants agreed that essential to a meditation practice is its use of (a) a defined technique, (b) logic relaxation, and (c) a self-induced state. Participants also agreed that a meditation practice may (d) involve a state of psychophysical relaxation somewhere in the process; (e) use a self-focus skill or anchor; (f) involve an altered state/mode of consciousness, mystic experience, enlightenment or suspension of logical thought processes; (g) be embedded in a religious/spiritual/philosophical context; or (h) involve an experience of mental silence. The results of this study provide insight into the challenges faced by researchers who want to demarcate meditative practices from nonmeditative practices, and they describe an approach to this problem that may prove useful for researchers trying to operationalize meditation in the context of comparative research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive and serotonergic vulnerability to depression: Convergent findings.

Cognitive reactivity (CR) is a psychological vulnerability marker of depression, whereas response to acute tryptophan depletion (ATD; a serotonergic challenge procedure) is a biological vulnerability marker. The aim of this study was to investigate the relationship between these markers. Thirty-nine remitted depressed patients participated in 2 ATD sessions in a double-blind crossover design. CR, assessed prior to the ATD sessions, predicted depressive response to high-dose ATD. CR also diminished the effects of 2 known predictors of ATD response: gender and residual symptoms. Neuroticism and behavioral inhibition were unrelated to ATD response. CR is associated with an increased sensitivity to reductions of serotonin concentrations. These findings present a small step toward unifying cognitive and neurobiological theories of depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)