SSME lifetime prediction and verification, integrating environments, structures, materials: The challenge

The planned missions for the space shuttle dictated a unique and technology-extending rocket engine. The high specific impulse requirements in conjunction with a 55-mission lifetime, plus volume and weight constraints, produced unique structural design, manufacturing, and verification requirements. Operations from Earth to orbit produce severe dynamic environments, which couple with the extreme pressure and thermal environments associated with the high performance, creating large low cycle loads and high alternating stresses above endurance limit which result in high sensitivity to alternating stresses. Combining all of these effects resulted in the requirements for exotic materials, which are more susceptible to manufacturing problems, and the use of an all-welded structure. The challenge of integrating environments, dynamics, structures, and materials into a verified SSME structure is discussed. The verification program and developmental flight results are included. The first six shuttle flights had engine performance as predicted with no failures. The engine system has met the basic design challenges

Current incentives for scientists lead to underpowered studies with erroneous conclusions

We can regard the wider incentive structures that operate across science – such as the priority given to novel findings – as an ecosystem within which scientists strive to maximise their fitness (i.e., publication record and career success). Here, we develop an optimality model that predicts the most rational research strategy, in terms of the proportion of research effort spent on seeking novel results rather than on confirmatory studies, and the amount of research effort per exploratory study. We show that, for parameter values derived from the scientific literature, researchers acting to maximise their fitness should spend most of their effort seeking novel results and conduct small studies that have only 10-40% statistical power. As a result, half of the studies they publish will report erroneous conclusions. Current incentive structures are in conflict with maximising the scientific value of research; we suggest ways that the scientific ecosystem could be improved

Prospective Investigation of Video Game Use in Children and Subsequent Conduct Disorder and Depression Using Data from the Avon Longitudinal Study of Parents and Children

There is increasing public and scientific concern regarding the long-term behavioural effects of video game use in children, but currently little consensus as to the nature of any such relationships. We investigated the relationship between video game use in children, degree of violence in games, and measures of depression and a 6-level banded measure of conduct disorder. Data from the Avon Longitudinal Study of Parents and Children were used. A 3-level measure of game use at age 8/9 years was developed, taking into account degree of violence based on game genre. Associations with conduct disorder and depression, measured at age 15, were investigated using ordinal logistic regression, adjusted for a number of potential confounders. Shoot-em-up games were associated with conduct disorder bands, and with a binary measure of conduct disorder, although the strength of evidence for these associations was weak. A sensitivity analysis comparing those who play competitive games to those who play shoot-em-ups found weak evidence supporting the hypothesis that it is violence rather than competitiveness that is associated with conduct disorder. However this analysis was underpowered, and we cannot rule out the possibility that increasing levels of competition in games may be just as likely to account for the observed associations as violent content. Overall game exposure as indicated by number of games in a household was not related to conduct disorder, nor was any association found between shoot-em-up video game use and depression

Postural instability in an immersive Virtual Reality adapts with repetition and includes directional and gender specific effects

The ability to handle sensory conflicts and use the most appropriate sensory information is vital for successful recovery of human postural control after injury. The objective was to determine if virtual reality (VR) could provide a vehicle for sensory training, and determine the temporal and spatial nature of such adaptive changes. Twenty healthy subjects participated in the study (10 females). The subjects watched a 90-second VR simulation of railroad (rollercoaster) motion in mountainous terrain during five repeated simulations, while standing on a force platform that recorded their stability. The immediate response to watching the VR movie was an increased level of postural instability. Repeatedly watching the same VR movie significantly reduced both the anteroposterior (62%, p < 0.001) and lateral (47%, p = 0.001) energy used. However, females adapted more slowly to the VR stimuli as reflected by higher use of total (p = 0.007), low frequency (p = 0.027) and high frequency (p = 0.026) energy. Healthy subjects can significantly adapt to a multidirectional, provocative, visual environment after 4–5 repeated sessions of VR. Consequently, VR technology might be an effective tool for rehabilitation involving visual desensitisation. However, some females may require more training sessions to achieve effects with VR

Illness Schema Activation and the Effects of Illness Seasonality on Accessibility of Implicit Illness-Related Information

The Common-Sense Model (CSM) of illness self-regulation is a leading theoretical framework describing the process by which an individual recognizes that he or she is physically ill and subsequently attempts to manage that illness state. The CSM proposes that people possess schematically organized implicit cognitive representations of health threats comprising information about illness such as symptoms, causes, label, duration, consequences, and procedures for managing threat [1, 2, 3, 4]. The proposed function of these stored knowledge structures is to activate a self-regulation process that might protect or restore a state of well-being [5]. The CSM proposes that the schematic representation is centrally activated by detection of deviations from the normal functioning self (i.e., experienced symptoms). The identification of illness and the initiation of self-management attempts follow from the search for illness-relevant cognitive structures and the matching of the content of illness schema to the symptomatic experience. For example, a headache (a symptomatic deviation from normal somatic experience) might activate illness schemata containing the cognitive representation of “headache” such as “hangover,” “dehydration,” or “flu.” The matching of the symptom to a particular illness schema will follow from the search and match to other aspects of plausible illness representations, such as its probable cause or duration (timeline).Full Tex

Genetic and neurological foundations of customer orientation: field and experimental evidence

We explore genetic and neurological bases for customer orientation (CO) and contrast them with sales orientation (SO). Study 1 is a field study that establishes that CO, but not SO, leads to greater opportunity recognition. Study 2 examines genetic bases for CO and finds that salespeople with CO are more likely to have the 7R variant of the DRD4 gene. This is consistent with basic research on dopamine receptor activity in the brain that underlies novelty seeking, the reward function, and risk taking. Study 3 examines the neural basis of CO and finds that salespeople with CO, but not SO, experience greater activation of their mirror neuron systems and neural processes associated with empathy. Managerial and research implications are discussed

Gene transfer and expression in human neutrophils. The phox homology domain of p47(phox )translocates to the plasma membrane but not to the membrane of mature phagosomes

BACKGROUND: Neutrophils are non-dividing cells with poor survival after isolation. Consequently, exogenous gene expression in neutrophils is challenging. We report here the transfection of genes and expression of active proteins in human primary peripheral neutrophils using nucleofection. RESULTS: Exogenous gene expression in human neutrophils was achieved 2 h post-transfection. We show that neutrophils transfected by nucleofection are functional cells, able to respond to soluble and particulate stimuli. They conserved the ability to undergo physiological processes including phagocytosis. Using this technique, we were able to show that the phox homology (PX) domain of p47(phox )localizes to the plasma membrane in human neutrophils. We also show that RhoB, but not the PX domain of p47(phox), is translocated to the membrane of mature phagosomes. CONCLUSION: We demonstrated that cDNA transfer and expression of exogenous protein in human neutrophils is compatible with cell viability and is no longer a limitation for the study of protein function in human neutrophils

Financial difficulties but not other types of recent negative life events show strong interactions with 5-HTTLPR genotype in the development of depressive symptoms

Several studies indicate that 5-HTTLPR mediates the effect of childhood adversity in the development of depression, while results are contradictory for recent negative life events. For childhood adversity the interaction with genotype is strongest for sexual abuse, but not for other types of childhood maltreatment; however, possible interactions with specific recent life events have not been investigated separately. The aim of our study was to investigate the effect of four distinct types of recent life events in the development of depressive symptoms in a large community sample. Interaction between different types of recent life events measured by the List of Threatening Experiences and the 5-HTTLPR genotype on current depression measured by the depression subscale and additional items of the Brief Symptom Inventory was investigated in 2588 subjects in Manchester and Budapest. Only a nominal interaction was found between life events overall and 5-HTTLPR on depression, which failed to survive correction for multiple testing. However, subcategorising life events into four categories showed a robust interaction between financial difficulties and the 5-HTTLPR genotype, and a weaker interaction in the case of illness/injury. No interaction effect for the other two life event categories was present. We investigated a general non-representative sample in a cross-sectional approach. Depressive symptoms and life event evaluations were self-reported. The 5-HTTLPR polymorphism showed a differential interaction pattern with different types of recent life events, with the strongest interaction effects of financial difficulties on depressive symptoms. This specificity of interaction with only particular types of life events may help to explain previous contradictory findings

Epigenetic and Genetic Factors Predict Women's Salivary Cortisol following a Threat to the Social Self

10.1371/journal.pone.0048597PLoS ONE711