Linear instability signals the initiation of motion of a twin plane under load

This letter presents a study of the atomic mechanism of the initiation of motion of a static twin plane under applied mechanical load in a model shape-memory material. By tracking the deformation under load and using linear stability analysis, we find that the eigenvalues of the Hessian matrix provide an indicator of the initiation of motion of the twin plane. The initiation of motion is signaled by a linear instability and a drop in the lowest eigenvalue to zero as well as a sharp drop in higher eigenvalues. Additionally, by comparing with direct molecular dynamics, we see that the eigenmode associated with the zero eigenvalue is found to accurately predict the initial mode of motion. We also find that the initial motion occurs through the formation of a stacking fault just ahead of the existing twin plane and the broadening of the stacking fault drives further transformation.     

胃肠道肿瘤的分子靶向治疗:未来的方向?

分子靶向治疗是这几年来消化道肿瘤治疗领域的热门话题.这类新一代的分子靶向生物治疗模式,将在临床治疗肿瘤实践中具有广阔的应用前景.从事肿瘤研究的临床医务人员需要综合归纳这些信息,融汇入自己的认知将之合理应用于患者.我们将真正进入传统的细胞毒性药物攻击与非细胞毒性靶向性药物相结合使用的时代,真正实现延长患者的生命,改善其生活质量的目标.     

Does habit strength moderate the intention–behaviour relationship in the Theory of Planned Behaviour? The case of fruit consumption

The present study examined if habit strength moderated the influence of intention on fruit consumption in a Dutch adult sample (N?=?521, 46.3% males, mean age?=?34.50, SD?=?10.87), using the theoretical relations of the Theory of Planned Behaviour (TPB). TPB variables and habit strength were assessed at baseline. Fruit consumption was assessed with a validated questionnaire five weeks later. Three groups were created: low habit strength (n?=?180), medium habit strength (n?=?185) and high habit strength (n?=?156). Confirmatory factor analyses and multi-group path analyses were performed using AMOS 4.0. A good fit was obtained for the overall measurement model and the structural models. Multi-group path analyses showed that intention was a significant predictor of fruit consumption in the low habit (β?=?0.36, p?<?0.001) and medium habit group (β?=?0.30, p?<?0.001), but a non-significant predictor in the high habit group (β?=?0.05, p?=?0.596). Implications for information-based and motivation-based interventions are discussed.     

Deformation twinning and plastic recovery in Cu/Ag nanolayers under uniaxial tensile straining

Molecular dynamics simulations of nanoscale multilayered Cu/Ag metals have been conducted under uniaxial tensile straining to elucidate the out-of-plane deformation behaviour relevant to tensile spallation experiments. In nanolayers with pristine architectures, plastic dissipation prior to crack nucleation is suppressed owing to the high hydrostatic tensile stress state. The presence of sources for micro-twinning partials, such as micro-cracks or columnar grain boundaries, result in abundant deformation twin lamellae across multiple Cu/Ag interlayers. Plastic recovery is observed during unloading of the nanolayers.     

Crystal growth velocity in deeply undercooled Ni–Si alloys

The crystal growth velocity of Ni₉₅Si₅ and Ni₉₀Si₁₀ alloys as a function of undercooling is investigated using molecular dynamics simulations. The modified imbedded atom method potential yields the equilibrium liquidus temperatures T _L?≈?1505 and 1387?K for Ni₉₅Si₅ and Ni₉₀Si₁₀ alloys, respectively. From the liquidus temperatures down to the deeply undercooled region, the crystal growth velocities of both the alloys rise to the maximum with increasing undercooling and then drop slowly, whereas the athermal growth process presented in elemental Ni is not observed in Ni–Si alloys. Instead, the undercooling dependence of the growth velocity can be well-described by the diffusion-limited model, furthermore, the activation energy associated with the diffusion from melt to interface increases as the concentration increases from 5 to 10?at.% Si, resulting in the remarkable decrease of growth velocity.     

Changes in Catastrophizing and Depressed Mood During and After Early Cognitive Behaviorally Oriented Interventions for Pain

Catastrophizing and depressed mood are risk factors for poor outcome in treatments for pain and appear to act as mediators for favorable outcome. However, little is known about how catastrophizing and depressed mood co-occur within individuals and how these patterns change during treatment, which is the focus of the current study. The study uses data from a randomized controlled trial about early cognitive behaviorally oriented interventions for patients with nonspecific spinal pain (N = 84). Cluster analyses were used to extract subgroups of individuals with similar scoring patterns on catastrophizing and depressed mood at pretreatment, mid-treatment, posttreatment, and at 6 months' follow-up. To track individual progress, the clusters were linked over time. The analyses revealed four clusters: “low depression and catastrophizing”, “high depression and catastrophizing”, “high depression”, and “high catastrophizing”. There was little individual transition from one scoring pattern to another across time, not at least for those scoring high on both depressed mood and catastrophizing. Moreover, high stability within this cluster was related to low levels of psychological flexibility at baseline. It is concluded that catastrophizing and depressed mood at the start of treatment were likely to remain high despite a cognitive behavioral intervention and that a lack of psychological flexibility may have a role.     

A Latent Variable Framework for Power Estimation Within Intervention Contexts

This paper presents a latent growth SEM approach for the estimation of treatment effects, and power to detect such effects, within a true experimental design setting in which subjects are randomly assigned to treatment and control conditions. Power estimation is a critical component of intervention experiment design and the testing of their results. Although researchers have become increasingly sophisticated in applying tests for statistical significance in intervention contexts, few are aware of the power of these tests. The issues raised in this paper are not new; however, reminding researchers to consider these points is important. Exactly how the researcher handles these issues will depend on the questions asked and the resources available, as well as other considerations. Discussion underscores the relationship between the reliability of a study's measures and concomitant increases in power obtained within the SEM framework.     

Linkage analysis: Modus operandi, ritual, and signature in serial sexual crime

This article examines a process of behavioral analysis, referred to as linkage analysis, used in identifying sexual offenses that have been committed by the same offender. This type of analysis examines behavior that is contained in three distinct components of a crime, i.e., the modus operandi (MO) or the “how to” of a crime; the ritual or fantasy-based behaviors for a particular type or series of sexual crimes; the signature or unique combination of behaviors, which suggests that a series of crimes has been perpetrated by the same offender. Linkage analysis involves five assessment procedures: (1) gathering detailed, varied, and multisource documentation; (2) reviewing the documentation and identifying significant features of each crime individually across the series; (3) classifying the significant features of the crime as either MO and/or ritualistic constructs; (4) comparing the combination of MO and ritualistic features across the crimes to determine if a signature exists; (5) compiling a written analysis that details the conclusions derived from the available information. Results of this type of analysis can be used for investigative purposes and, in some instances, can help to inform the decision-making of the courts.     

Emotion Regulation Across the Life Span: An Integrative Perspective Emphasizing Self-Regulation,Positive Affect,and Dyadic Processes

In this commentary, we build upon the papers featured in this 2-part special issue to advance an integrative perspective on emotion regulation that emphasizes the developmentally specific goal-contexts of emotional phenomena. We highlight the importance of (1) multilevel longitudinal investigations of interactions among biological, affective, cognitive, and behavioral processes with respect to emotion regulation; (2) the integration of emotion-regulation processes with self-regulatory processes across the life course; (3) the dynamic relationship between positive and negative affect and their respective influence on regulatory processes; and (4) greater consideration of the dyadic context of emotion-regulation processes. From this perspective, the optimal developmental outcome with respect to emotion regulation is not affective homeostasis, but rather a dynamic flexibility in emotional experience, the ability to pursue and prioritize different goals, and the capacity to selectively and proactively mobilize emotions and cognitions in the service of context-specific and developmentally specific goals.