Effect of pre-straining on the size effect in molybdenum pillars

The effect of prior deformation on mechanical behavior as a function of size is investigated for body-centered cubic (bcc) molybdenum (Mo) pillars. Experiments were performed using focused ion beam (FIB) manufactured [0 0 1] and [2 3 5] Mo micro/nanopillars, which were compressed, re-FIB machined, and compressed again. Unlike in bulk materials, pre-straining has a negligible effect on stress–strain behavior of the pillars, suggesting that dislocation storage does not occur in small-scale bcc specimens. The prevailing mechanism behind the size effect is attributed to dislocation nucleation mechanisms.     

Failure mode of isotropic three-dimensional reticulated porous materials under various compressive loads

The failure mode of isotropic three-dimensional reticulated porous materials under compression has been investigated. A mathematical relationship between nominal main stresses and porosity has been derived for this class of materials at shearing failure under various compressive loads from the simplified structural model of an octahedron. These compressive loads cover all three loading conditions, including uniaxial compression, biaxial compression and triaxial compression. The results indicate that (1) the failure mode is relative to the material species of these porous bodies under compression, (2) the porous body of brittle material species will show the tensile fracture mode of pore struts and (3) the porous body of ductile material species will probably display the shearing fracture mode of pore struts. Through a relevant expression, the criterion of strength design can be enhanced for these porous materials under shearing failure caused by compressive loadings.     

主动控制感在大脑表征中的时空标记

主动控制感是主动动作过程中产生的控制自身动作, 进而控制外部环境的主观体验。构成动作主动控制感的核心要素是主观意图与结果反馈。本研究试图通过操控这两个核心要素的不同属性, 借助脑磁图等技术, 探寻主动控制感在大脑额-顶为主的脑网络中前-后馈的作用方式及时空特异性标记, 并建构新的认知神经理论模型。这将有利于理解人类动作的产生及后效、为相关精神类疾病的临床诊断提供更加客观的参照标准。     

Angry Versus Furious: A Comparison Between Valence and Arousal in Dimensional Models of Emotions

The present study compared the roles of valence and arousal, proposed by the dimensional models of emotions, in recognizing emotional expressions. It was hypothesized that the dimension of valence, due to its functional significance, would be more salient in the recognition of emotional expressions than the dimension of arousal would be. The results of the current study supported this hypothesis. The participants in all age groups were more accurate and quicker in recognizing an emotion when the expression was paired up with another emotional expression that was different in the polarity of the valence dimension than with this similar polarity difference in the arousal dimension. The insignificant difference in recognizing the positive and negative emotional expressions in the group of elders also rejected the Socio-Emotional Selectivity Theory.     

Compression and texture in socks enhance football kicking performance

The purpose of this study was to observe effects of wearing textured insoles and clinical compression socks on organisation of lower limb interceptive actions in developing athletes of different skill levels in association football. Six advanced learners and six completely novice football players (15.4 ± 0.9 years) performed 20 instep kicks with maximum velocity, in four randomly organised insoles and socks conditions, (a) Smooth Socks with Smooth Insoles (SSSI); (b) Smooth Socks with Textured Insoles (SSTI); (c) Compression Socks with Smooth Insoles (CSSI) and (d), Compression Socks with Textured Insoles (CSTI). Reflective markers were placed on key anatomical locations and the ball to facilitate three-dimensional (3D) movement recording and analysis. Data on 3D kinematic variables and initial ball velocity were analysed using one-way mixed model ANOVAs. Results revealed that wearing textured and compression materials enhanced performance in key variables, such as the maximum velocity of the instep kick and increased initial ball velocity, among advanced learners compared to the use of non-textured and compression materials. Adding texture to football boot insoles appeared to interact with compression materials to improve kicking performance, captured by these important measures. This improvement in kicking performance is likely to have occurred through enhanced somatosensory system feedback utilised for foot placement and movement organisation of the lower limbs. Data suggested that advanced learners were better at harnessing the augmented feedback information from compression and texture to regulate emerging movement patterns compared to novices.     

Optimal Scoring of the Multidimensional Pain Inventory in a Chronic Pain Sample

The Multidimensional Pain Inventory (MPI) is one of the most commonly used self-report instruments in pain settings. The MPI can be used to classify patients into three clusters or its nine scales can be treated as dimensions in efforts to understand patient heterogeneity. Previous research suggests the existence of a fourth cluster, whose members have been labeled ‘repressors,’ that emerges with the addition of a defensiveness scale to the MPI. The current paper compared the abilities of MPI cluster and dimensional models with and without a measure of defensiveness to capture variability in validating variables related to personality, psychopathology, physical functioning, and treatment outcome in a chronic pain sample. Results suggest that dimensional models consistently outperform cluster models in explaining variance in outcome variables, and that the addition of a measure of defensiveness increments the validity offered by the MPI scales. Implications for the assessment of pain patients are discussed.

Problem decomposability as a factor in complexity of the dimensional change card sort task

According to cognitive complexity and control (CCC) theory complexity depends on number of levels of a hierarchy of rules. According to relational complexity (RC) theory complexity is a function of the number of related variables in the task, and the most difficult tasks are those in which there is a constraint on decomposition into simpler subtasks. One hundred and twenty, 3–6-year old children were tested on the standard dimensional change card sort (DCCS) task, or a modified version, the DecompDCCS, in which the dimensions could be decomposed into subtasks. The standard version requires two levels of a hierarchy to be processed, and is ternary relational according to RC theory, whereas the subtasks of the DecompDCCS are binary relational. The DecompDCCS was easier than the DCCS for 3–4 year-olds, but all 5–6 year-olds succeeded on both. The results indicate that decomposability into simpler subtasks, as suggested by RC theory, is a factor in difficulty of DCCS. The role of decomposability in other tasks that are persistently difficult for young children is discussed.     

Temporal compression in episodic memory for real-life events

Remembering an event typically takes less time than experiencing it, suggesting that episodic memory represents past experience in a temporally compressed way. Little is known, however, about how the continuous flow of real-life events is summarised in memory. Here we investigated the nature and determinants of temporal compression by directly comparing memory contents with the objective timing of events as measured by a wearable camera. We found that episodic memories consist of a succession of moments of prior experience that represent events with varying compression rates, such that the density of retrieved information is modulated by goal processing and perceptual changes. Furthermore, the results showed that temporal compression rates remain relatively stable over one week and increase after a one-month delay, particularly for goal-related events. These data shed new light on temporal compression in episodic memory and suggest that compression rates are adaptively modulated to maintain current goal-relevant information.     

Définir ou détecter des pathologies ? Utilisation et interprétation des scores seuils à la lumière du débat dimensions/catégories

A number of psychometric tests are aimed at locating the performance of an individual along a continuous range that goes from normal to worrying. In a different paradigm, there are tests whose goal is to assess whether or not an individual is healthy with respect to a psychological, psychiatric or neurological pathology that is defined independently from the test itself. The former rely on a dimensional concept of psychopathologies; the latter imply a categorical concept. The former require to compare the performance of the individual to a standard sample that is representative of the general population; the latter involve a standard sample representative of the healthy population only. The former might imply the use of a cut-off score to indicate that a certain degree of rarity of the performance has been reached, while the latter must involve a cut-off score to make a decision (whether the individual belongs to the “healthy” or “pathological” category), a score that is most often set so as to control the false-positive rate in making this decision. In the former paradigm, the cut-off score defines or contributes to define the pathology. In the latter, it only helps detecting it. This article aims at making clear the difference between these two realms and highlight their practical as well as theoretical impact on psychological practice.     

椎体成形术和球囊扩张椎体后凸成形术治疗骨质疏松性椎体压缩骨折的对比研究

为对比分析椎体成形术（PVP）与球囊扩张椎体后凸成形术（PKP）治疗骨质疏松性椎体压缩骨折的临床疗效。共治疗患者45例。PVP25例,PKP20例。所有患者术后疼痛均明显减轻或消失,PVP组与PKP组两组相比,术后的伤椎及相邻椎间隙高度、脊柱后凸Cobb角及ODI评分差异有统计学意义（P〈0．05）。PKP能够更好的恢复骨折椎体的高度,矫正脊柱后凸畸形,改善脊柱功能,明显减少骨水泥渗漏,临床效果较PVP更为满意。