Constraining type Ia supernova models:SN 2011fe as A test case

The nearby supernova SN 2011fe can be observed in unprecedented detail. Therefore, it is an important test case for Type Ia supernova (SN Ia) models, which may bring us closer to understanding the physical nature of these objects. Here, we explore how available and expected future observations of SN 2011fe can be used to constrain SN Ia explosion scenarios. We base our discussion on three-dimensional simulations of a delayed detonation in a Chandrasekhar-mass white dwarf and of a violent merger of two white dwarfs (WDs) - realizations of explosion models appropriate for two of the most widely discussed progenitor channels that may give rise to SNe Ia. Although both models have their shortcomings in reproducing details of the early and near-maximum spectra of SN 2011fe obtained by the Nearby Supernova Factory (SNfactory), the overall match with the observations is reasonable. The level of agreement is slightly better for the merger, in particular around maximum, but a clear preference for one model over the other is still not justified. Observations at late epochs, however, hold promise for discriminating the explosion scenarios in a straightforward way, as a nucleosynthesis effect leads to differences in the Co production. SN 2011fe is close enough to be followed sufficiently long to study this effect. © © 2012 The American Astronomical Society. All rights reserved.

The buffering effect of hope on clinicians' behavior:A test in pediatric primary care

Although trait hope is thought to motivate goal-directed actions in the face of impediments, few studies have directly examined hope's role in overcoming obstacles, and none have done so while accounting for related goal constructs. We describe a study of 127 pediatric primary care providers who over the course of a year were asked to identify new cases of asthma and confirm previously diagnosed active disease by completing for each of their patients a brief survey validated for this purpose. These clinicians also completed measures of hope, self-efficacy, conscientiousness, and perceived obstacles to implementing a pediatric asthma management program. As predicted by hope theory, the agency component of hope buffered clinicians from perceived obstacles by facilitating the identification of asthma cases among high-hope clinicians in the face of obstacles. This buffering effect remained after controlling for self-efficacy and conscientiousness. We discuss the study findings in terms of current theories of goal-directed behavior and implications for delivering hope-related interventions, and we offer a testable hypothesis regarding when agency and pathways thinking facilitate goal-related behavior.

Relations Between Political Violence and Child Adjustment: a four-wave test of the role of emotional insecurity about community

This study further explored the impact of sectarian violence and children's emotional insecurity about community on child maladjustment using a 4-wave longitudinal design. The study included 999 mother-child dyads in Belfast, Northern Ireland (482 boys, 517 girls). Across the 4 waves, child mean age was 12.19 (SD = 1.82), 13.24 (SD = 1.83), 13.61 (SD = 1.99), and 14.66 years (SD = 1.96), respectively. Building on previous studies of the role of emotional insecurity in child adjustment, the current study examines within-person change in emotional insecurity using latent growth curve analyses. The results showed that children's trajectories of emotional insecurity about community were related to risk for developing conduct and emotion problems. These findings controlled for earlier adjustment problems, age, and gender, and took into account the time-varying nature of experience with sectarian violence. Discussion considers the implications for children's emotional insecurity about community for relations between political violence and children's adjustment, including the significance of trajectories of emotional insecurity over time.

Supernatural Beliefs, Unconscious Threat and Judgment Bias in Tibetan Buddhists

Individuals who have been subtly reminded of death display heightened in-group favouritism, or “worldview defense.” Terror management theory argues (i) that death cues engender worldview defense via psychological mechanisms specifically evolved to suppress death anxiety, and (ii) that the core function of religiosity is to suppress death anxiety. Thus, terror management theory predicts that extremely religious individuals will not evince worldview defense. Here, two studies are presented in support of an alternative perspective. According to the unconscious vigilance hypothesis, subtly processed threats (which need not pertain to death) heighten sensitivity to affectively valenced stimuli (which need not pertain to cultural attitudes). From this perspective, religiosity mitigates the influence of mortality-salience only insofar as afterlife doctrines reduce the perceived threat posed by death. Tibetan Buddhism portrays death as a perilous gateway to rebirth rather than an end to suffering; faith in this doctrine should therefore not be expected to nullify mortality-salience effects. In Study 1, devout Tibetan Buddhists who were subtly reminded of death produced exaggerated aesthetic ratings unrelated to cultural worldviews. In Study 2, devout Tibetan Buddhists produced worldview defense following subliminal exposure to non-death cues of threat. The results demonstrate both the domain-generality of the process underlying worldview defense and the importance of religious doctrinal content in moderating mortality-salience effects.

Human resource management practices in the multinational company: A test of system, societal, and dominance effects

Does the use of HRM practices by multinational companies (MNCs) reflect their national origins or are practices similar regardless of context? To the extent that practices are similar, is there any evidence of global best standards? The authors use the system, societal, and dominance framework to address these questions through analysis of 1,100 MNC subsidiaries in Canada, Ireland, Spain, and the United Kingdom. They argue that this framework offers a richer account than alternatives such as varieties of capitalism. The study moves beyond previous research by differentiating between system effects at the global level and dominance effects arising from the diffusion of practices from a dominant economy. It shows that both effects are present, as are some differences at the societal level. Results suggest that MNCs configure their HRM practices in response to all three forces rather than to some uniform global best practices or to their national institutional contexts.

Evaluation of a substructured soft Real-time Hybrid Test for performing Seismic analysis of complex structural systems

The hybrid test method is a relatively recently developed dynamic testing technique that uses numerical modelling combined with simultaneous physical testing. The concept of substructuring allows the critical or highly nonlinear part of the structure that is difficult to numerically model with accuracy to be physically tested whilst the remainder of the structure, that has a more predictable response, is numerically modelled. In this paper, a substructured soft-real time hybrid test is evaluated as an accurate means of performing seismic tests of complex structures. The structure analysed is a three-storey, two-by-one bay concentrically braced frame (CBF) steel structure subjected to seismic excitation. A ground storey braced frame substructure whose response is critical to the overall response of the structure is tested, whilst the remainder of the structure is numerically modelled. OpenSees is used for numerical modelling and OpenFresco is used for the communication between the test equipment and numerical model. A novel approach using OpenFresco to define the complex numerical substructure of an X-braced frame within a hybrid test is also presented. The results of the hybrid tests are compared to purely numerical models using OpenSees and a simulated test using a combination of OpenSees and OpenFresco. The comparative results indicate that the test method provides an accurate and cost effective procedure for performing
full scale seismic tests of complex structural systems.