False-belief understanding in 2.5-year-olds: evidence from two novel verbal spontaneous-response tasks

Recent research indicates that toddlers and infants succeed at various non-verbal spontaneous-response false-belief tasks; here we asked whether toddlers would also succeed at verbal spontaneous-response false-belief tasks that imposed significant linguistic demands. We tested 2.5-year-olds using two novel tasks: a preferential-looking task in which children listened to a false-belief story while looking at a picture book (with matching and non-matching pictures), and a violation-of-expectation task in which children watched an adult 'Subject' answer (correctly or incorrectly) a standard false-belief question. Positive results were obtained with both tasks, despite their linguistic demands. These results (1) support the distinction between spontaneous- and elicited-response tasks by showing that toddlers succeed at verbal false-belief tasks that do not require them to answer direct questions about agents' false beliefs, (2) reinforce claims of robust continuity in early false-belief understanding as assessed by spontaneous-response tasks, and (3) provide researchers with new experimental tasks for exploring early false-belief understanding in neurotypical and autistic populations.     

Discontinuous cracking of TiN films on a steel substrate induced by an adhesive interlayer

ABSTRACT

The basic mechanisms governing the process of cracking of single-layer brittle films have been extensively explored through both simulations and experiments. However, the role that an adhesive interlayer plays in the cracking of the overlying brittle film remains unclear. By performing three-point bending experiments, we observed that the insertion of a 100?nm thick Ti interlayer changed the cracking behaviour of TiN films from a continuous pattern to a discontinuous pattern. The slight change in the microstructure of the film and the increase in film thickness arising from the addition of the Ti interlayer are unlikely to cause the observed cracking morphology. The combination of the different interface between the Ti and the steel substrate and the fracture of the Ti interlayer are responsible for the transition in the TiN film cracking morphologies.     

A study of the spin-Hamiltonian parameters for Cr5+ at the rhombically-distorted tetrahedral P5+ site of Ca2PO4Cl crystal using a two-mechanism model

The complete high-order perturbation formulae of spin-Hamiltonian (SH) parameters (g factors g_i and hyperfine structure constants A_i , where i = x, y, z) containing contributions from both the crystal-field (CF) and charge-transfer (CT) mechanisms (the latter mechanism is neglected in the widely-used CF theory) are established for d¹ ions in rhombic tetrahedra. From these formulae, the SH parameters of Cr⁵⁺ ion at the rhombically-distorted tetrahedral P⁵⁺ site of Ca₂PO₄Cl crystal are calculated. The CF and CT energy levels used in the calculation are obtained from the optical spectra of the studied Ca₂PO₄Cl : Cr⁵⁺ crystal. The calculated results showed reasonable agreement with the experimental values. The signs of the hyperfine structure constants A_i and the relative importance of the CT mechanism to SH parameters are acquired from the calculations.     

Interaction of a dislocation with an elliptical hole in icosahedral quasicrystals

The interaction between a dislocation and an elliptical hole in icosahedral quasicrystals is considered. An explicit expression for the complex potential is derived using the extended Stroh formalism. Based on the conformal mapping method and a perturbation technique, closed-form solutions are obtained. The field intensity factors at a crack tip and the image forces on the dislocation arising from the crack are calculated. The effects of phonon–phason elastic coupling on the mechanical behavior are also observed.     

The Strengths and Difficulties Questionnaire (SDQ): the Factor Structure and Scale Validation in U.S. Adolescents

The Strengths and Difficulties Questionnaire (SDQ) is one of the most commonly used instruments for screening psychopathology in children and adolescents. This study evaluated the hypothesized five-factor structure of the SDQ and examined its convergent validity against comprehensive clinical diagnostic assessments. Data were derived from the National Comorbidity Survey - Adolescent Supplement (NCS-A), a nationally representative sample of U.S. adolescents aged 13 to 18 years. Parents/parent surrogates (n=6,483) was asked to complete a self-administered questionnaire including the SDQ and DSM-IV comprehensive diagnostic information on the participating adolescents. Confirmatory factor analysis (CFA) was conducted to assess the factor structure of the SDQ. The five-factor solution of the SDQ (including emotional, conduct, hyperactivity-inattention, peer relationship, and prosocial) provided a satisfactory fit to the data, and was invariant across sex, age, race/ethnicity and income subgroups. SDQ scores predicted a significantly increased probability of meeting criteria for a DSM-IV disorder, with better prediction for behavior disorders than for mood disorders. Decreasing the SDQ cutoffs to the 80th percentile significantly increased the sensitivity from 39% to 63% for the SDQ Total Difficulties Score, with an expected decrease in specificity from 93% to 87%. This work confirms the five-factor structure of the SDQ in an ethnically and sociodemogrpahically diverse community sample of adolescents. Our findings strengthen empirical evidence for the use of the parent-reported SDQ as a screening tool for DSM-IV behavioral and emotional disorders in adolescents identified in the general population.     

单侧化准备电位启始时间点的测算:刀切法*

刀切法是统计学家Quenouille提出的一种参数估计方法,由Miller等在1998年首次将刀切法应用在单侧化准备电位(LRP)启始时间点(onset)的测量中。相对于以往单个被试法而言,它是较新的一种统计方法。本文综述了刀切法的统计原理和基本使用过程,并和单个被试法进行了差异比较,最后对这一方法的发展趋势做了展望。     

Kinematics, kinetics, and electromyogram of ankle during drop landing: a comparison between dominant and non-dominant limb

The biomechanical difference between the dominant and non-dominant limb has seldom been studied during double-leg landing. The objective of this study was to evaluate the effectiveness of limb laterality on the ankle kinematics, kinetics and electromyogram (EMG) during drop landing. Sixteen healthy adults were recruited and dropped individually from platforms with three different heights (0.32 m, 0.52 m, and 0.72 m). The ground reaction force, ankle joint kinematics, and surface EMG of tibialis anterior (TA) and lateral gastrocnemius (LG) were measured in both lower extremities. Two-way analysis of variance was used to analyze the effects of laterality and dropping height. The peak angular velocities in dorsiflexion and abduction were significantly higher in the dominant ankle, whereas the pre- and post-landing EMG amplitudes of the TA were significantly higher in the non-dominant limb. Compared with the dominant side, the non-dominant ankle has a more effective protective mechanism in that excessive joint motion is restrained by greater ankle flexor activity. Compared with the non-dominant side, the dominant ankle joint is in greater injury risk during drop landing, and data measured in the dominant limb may produce more conservative conclusions for injury protection or prediction.     

Extreme response style as a cultural response to climato‐economic deprivation

We investigated the effects of climato‐economic harshness on extreme response style. Climato‐economic theorising postulates that a more threatening climate in poorer countries, in contrast to countries with a more comforting climate and richer countries with a more challenging climate, triggers intolerance of ambiguity and uncertainty avoidance inherent to conservatism, in‐group favouritism and autocracy. Scores of extreme response style at country level, a proxy of this cluster of cultural characteristics, were extracted from students' responses in the Programme for International Student Assessment to test the hypothesis. In a series of hierarchical regression analysis across 64 countries, cold demands, heat demands and GDP per capita showed a highly significant interaction effect on extreme response style, predicting in total 30.7% of the variance. Extreme response style was highest in poorer countries with higher climatic demands, and lowest in richer countries with lower climate demands. Implications are discussed.     

Loneliness and Suicidal Risk in Young Adults: Does Believing in a Changeable Future Help Minimize Suicidal Risk Among the Lonely?

This study examined loneliness and future orientation as predictors of suicidal risk, namely, depressive symptoms and suicide ideation, in a sample of 228 college students (54 males and 174 females). Results of regression analyses indicated that loneliness was a significant predictor of both indices of suicidal risk. The inclusion of future orientation was found to significantly augment the prediction model of both depressive symptoms and suicide ideation, even after accounting for loneliness. Noteworthy, beyond loneliness and future orientation, the Loneliness × Future Orientation interaction term was found to further augment both prediction models of suicidal risk. Consistent with the notion that future orientation is an important buffer of suicidal risk, among lonely students, those with high future orientation, compared to low future orientation, were found to report significantly lower levels of depressive symptoms and suicide ideation. Some implications of the present findings for studying both risk and protective factors associated with suicidal risk in young adults are discussed.