Aggregating and Testing Intra-Individual Correlations: Methods and Comparisons

From a longitudinal study, we have repeatedly measured data from multiple individuals at multiple occasions. For each individual, the relation between 2 variables can be measured by the Pearson’s correlation. The question is how to aggregate the multiple correlations and conduct statistical inference on the aggregated intra-individual correlation. Several methods are proposed to aggregate and test intra-individual correlations: (a) a meta-analysis method based on Fisher’s Z transformed correlations, (b) a meta-analysis method based on the Pearson’s correlations, and (c) a multilevel modeling method using data standardized within each individual. The performance of the methods after bias corrections was compared using simulations with considering factors including numbers of individuals, numbers of time points, population effect sizes, and their distribution forms (homogeneous vs heterogeneous). The results from the simulation studies show that estimation biases were found using the meta-analytic methods and suggestions on when and how to correct biases were provided based on the simulation results. Furthermore, the performance of the 3 methods after necessary bias corrections was found to be comparable and reasonably good, indicating that all 3 methods worked for aggregating and testing intra-individual correlations. An empirical daily diary data set was then used to illustrate the applications of the 3 methods. The assumptions, advantages and disadvantages, and possible extensions of the 3 methods were discussed.     

Motivational pathways to STEM career choices: Using expectancy–value perspective to understand individual and gender differences in STEM fields

The United States has made a significant effort and investment in STEM education, yet the size and the composition of the STEM workforce continues to fail to meet demand. It is thus important to understand the barriers and factors that influence individual educational and career choices. In this article, we conduct a literature review of the current knowledge surrounding individual and gender differences in STEM educational and career choices, using expectancy–value theory as a guiding framework. The overarching goal of this paper is to provide both a well-defined theoretical framework and complementary empirical evidence for linking specific sociocultural, contextual, biological, and psychological factors to individual and gender differences in STEM interests and choices. Knowledge gained through this review will eventually guide future research and interventions designed to enhance individual motivation and capacity to pursue STEM careers, particularly for females who are interested in STEM but may be constrained by misinformation or stereotypes.     

Exposure to violence reduces empathetic responses to other’s pain

Past researches showed that empathy for pain not only triggers a resonance mechanism between other and self, but also is modulated by contextual factors. Using functional magnetic resonance imaging, the present study demonstrated that short-term media violence exposure reduced both pain ratings and also the activation of anterior insula and anterior mid-cingulate cortex to other’s pain. Thus, violence exposure modulated empathic responses to other’s pain based on a physiological desensitization.     

Charting the Developmental Trajectories of Attention and Executive Function in Chinese School-Aged Children

Attention is a complex domain that has reawakened research interest in recent years. There are relatively few studies that have examined age-related changes across different attention subcomponents, such as selection, maintenance, and control, using large samples covering a wide age range. The present study assessed performance in 466 participants in order to identify the ages at which mature performance was reached across differing attention subcomponents. Furthermore, we investigated whether the nature of the attentional demands or task difficulty predicted the age at which stable levels of performance were reached. The results supported the former rather than the latter alternative.     

Deformation-induced dislocations in 15R-SiC grown by sublimation

Single-crystal 15R-SiC boules have been successfully grown by sublimation. The Vickers hardness of a Si-terminated (0001) face has been measured in the temperature range 25-1300C. As expected, the hardness decreases with increasing temperature from about 30GPa at room temperature to about 10GPa at 1300C. The fracture toughness is estimated to be about 1.0MPam 1/2 at room temperature. Transmission electron microscopy investigation of the dislocations introduced by indentation at 900 and 1300C shows that they are activated predominantly on the basal plane. Most of them consist of a single leading partial without the corresponding trailing partial.     

Determination of electrostatic characteristics at a 24°, [001] tilt grain boundary in a SrTiO3 bicrystal by electron holography

The electrostatic potential and associated space charge across a 24°, [001] tilt boundary of SrTiO₃ ceramic have been determined using electron holography. The results reveal a positive charged interface with a negative space charge on either side. The form of the double Schottky barrier and the local charge-density distribution at the interface are derived from the results.     

Survey of plateau behaviour in the cyclic stress-strain curve of copper single crystals

Experimental results relating to the plateau behaviour in the cyclic stress-strain (CSS) curve of copper single crystals located on different sides of the stereographic triangle are summarized. Unlike the situation for single-sliporiented crystals, the crystallographic orientation has a strong effect on the plateau behaviour in the CSS curves of double- and multiple-slip-oriented crystals. The existence or non-existence of a plateau in the CSS curves, as well as the corresponding plateau stress amplitude, depend not only on the modes and intensities of dislocation interactions among slip systems operating in the crystals but also on the slip deformation characteristics associated with crystal orientations. The plateau region in CSS curve disappears only when multiple slip plays a determining role during cyclic deformation.     

Crystallization behaviour of Al-based amorphous alloy and nanocomposites by rapid quenching

The microstructure and crystallization behaviour of melt-spun Al₈₈Ni₉Ce₂Fe₁ amorphous alloy and nanophase composites have been studied by means of X-ray diffraction, transmission electron microscopy and scanning and isothermal calorimetry. The diffraction patterns from Al₈₈Ni₉Ce₂Fe₁ amorphous alloys are diffuse, indicating a basically amorphous structure but contain two rings presumed to be associated with quenched-in nuclei. In the cases of Al₈₈Ni₉Ce₂Fe₁ nanophase composites, nanoscale precipitated particles are homogeneously dispersed in an amorphous matrix, and the crystallite diameter and volume fraction are sensitive to quenching conditions. During thermal crystallization, a two-step phase transformation occurs in the amorphous alloy and nanocomposites, which is characterized by a diffusion-controlled precipitation of nanoscale Al particles and the growth of a Al₃(Ni, Fe) nanophase prior to a Al₁₁Ce₃ nanophase. This study gives insight into structure-control for obtaining nanophases dispersed in an amorphous matrix by rapid quenching.     

Cognition and Emotion in TV Message Processing: How Valence,Arousing Content,Structural Complexity,and Information Density Affect the Availability of Cognitive Resources

This paper examines whether emotional message content alters the effects of structural complexity and information density on available resources, measured by secondary task reaction times (STRTs), and message encoding, measured by audio recognition. In addition, hypotheses relating motivational activation and resource availability based on the motivational activation concepts of positivity offset (greater appetitive activation in a neutral environment) and negativity bias (faster aversive activation) influence are tested. Results replicate previous research supporting the contention that STRTs measure available resources. In addition, they show that the basic pattern of STRTs and recognition as a function of allocated and required resources is relatively consistent regardless of emotional content of the message. Emotion appears to function as a constant, increasing both resource allocation and resources required. Finally, these data provide some initial support for predicted relationships between motivational activation and resource allocation based on the constructs of positivity offset and negativity bias.