Three decades of composites activities at US Air Force Materials Laboratory

In the decades of 1960s–1980s, Air Force Materials Laboratory pioneered many programs and training of personnel that led to major advances in the understanding and utilization of composite materials and structures. The early involvement of industry resulted in rapid identification of the advantages and technical hurdles to be overcome. Through extensive use of postdoctoral appointments, ROTC at universities, visiting and exchange scientists, the Laboratory was able to reach many talented young people who in the years following have assumed leadership in teaching and research of composite materials worldwide. A recount of the activities during these three decades is timely because most of the “young” men and women who had spent time at the Laboratory will be ready to retire in the next few years.     

You protest too much, methinks: Investigating the features of truthful and fabricated reports of traumatic experiences.

Legal decision-makers frequently assess the credibility of reports of traumatic victimization. In this study, we compared the memory features and post-traumatic symptoms associated with truthful and malingered reports of trauma. Participants (N=126) described in writing both a genuine and a fabricated traumatic experience (counterbalanced) and completed scales relating to the severity of the associated trauma symptoms. Relative to accounts of genuine trauma, the information in fabricated accounts was less plausible and contained fewer contextual details. However, truthful and false reports were qualitatively similar on other criteria such as coherence and relevance. Fabricated traumatic experiences were associated with extreme ratings on multiple, diverse psychological measures of emotional distress and a higher level of apparent post-traumatic stress disorder. However, most participants were able to "fool" widely used validity scales. Implications for evaluating the credibility of claims of victimization in legal cases are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimism, coping, psychological distress, and high-risk sexual behavior among men at risk for acquired immunodeficiency syndrome (AIDS).

In a cohort of gay men responding to the threat of AIDS, dispositional optimism was associated with less distress, less avoidant coping, positive attitudes as a coping strategy, and fewer AIDS-related concerns. Men who knew they were seropositive for HIV were significantly more optimistic about not developing AIDS than men who knew they were seronegative for HIV. This AIDS-specific optimism was related to higher perceived control over AIDS and to active coping among seropositive men only and to health behaviors in both serostatus groups. There was no relation of optimism to risk-related sexual behavior. It is concluded that optimism is psychologically adaptive without necessarily compromising health behavior. It is also concluded that it is useful to distinguish between event-based optimistic expectations and dispositional optimism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis,chemical stability and application of a thiohydroxamic acid linker (THA) for solid-phase organic synthesis

The synthesis and chemical compatibility of a ‘traceless’ thiohydroxamic acid (THA) linker is reported. The linker is shown to be stable to visible light and heat. This paper also describes preliminary work in the application of the THA linker to act as a polymer-supported source of radicals.     

Extracts from red muscadine and cabernet sauvignon wines induce cell death in MOLT-4 human leukemia cells

Red wine contains a diversity of polyphenolic compounds that exert beneficial health effects including anti-cancer effects. This trial evaluated the anti-proliferative potential of red muscadine (Vitis rotundifolia) and red cabernet sauvignon (Vitis vinifera) wines in cell culture. Chemical properties of wines were determined by HPLC-PDA analysis and concentrated extracts of each wine were evaluated before and after glycosidic hydrolysis in MOLT-4 leukemia cells. Cell growth and the induction of apoptosis were evaluated after exposure to various extract dilutions. Wine extracts reduced cell viability up to 68% and cell numbers up to 50% after 48 h with muscadine extracts being more effective than cabernet sauvignon. Caspase-3 activity was induced similarly by all extracts in a dose dependent manner. Cell cycle arrest in the G₂/M phase was observed for both muscadine and the non-hydrolyzed cabernet sauvignon extract. Collectively, extracts from both wines exerted anti-cancer effects in leukemia cells.     

Modeling thermal effects in nano-devices

For the purpose of investigating the role of self-heating effects on the electrical characteristics of nano-scale devices, we implemented a two-dimensional Monte Carlo device simulator that self-consistently includes the solution of the energy balance equations for both, acoustic and optical phonons. We find less degradation in the current in smaller device structures because of the more pronounced velocity overshoot.     

Spatial memory during progressive disorientation.

Human spatial representations of object locations in a room-sized environment were probed for evidence that the object locations were encoded relative not just to the observer (egocentrically) but also to each other (allocentrically). Participants learned the locations of 4 objects and then were blindfolded and either (a) underwent a succession of 70° and 200° whole-body rotations or (b) were fully disoriented and then underwent a similar sequence of 70° and 200° rotations. After each rotation, participants pointed to the objects without vision. Analyses of the pointing errors suggest that as participants lost orientation, represented object directions generally "drifted" off of their true directions as an ensemble, not in random, unrelated directions. This is interpreted as evidence that object-to-object (allocentric) relationships play a large part in the human spatial updating system. However, there was also some evidence that represented object directions occasionally drifted off of their true directions independently of one another, suggesting a lack of allocentric influence. Implications regarding the interplay of egocentric and allocentric information are considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Arachidonic acid maldistribution in obesity

Arachidonic acid is an important regulator of cellular function via its effects on the physical properties of membranes, in its free form, or as a substrate for eicosanoids. Dietary studies indicate that its production is regulated, but the mechanisms of this regulation and factors influencing arachidonate distribution from the site of production remain to be determined. In particular, whether there is a nonoxidative fate for arachidonate once it has been released from phospholipid has yet to be determined. Variations in the arachidonate content of serum, liver, and muscle lipid fractions have been correlated with alterations in lipogenesis and insulin action, implying a role for arachidonate in fuel partitioning. Evidence for this mechanism acting systemically has been found in genetic models of obesity in rodents and also in humans. This review proposes that variation in the distribution of arachidonate between phospholipid and cholesteryl ester fractions participates in the abnormal fuel partitioning associated with some forms of genetic obesity.