Investigations of the optical and EPR spectra for VO2+ in NaHC2O4 · H2O single crystals

Theoretical calculations of the optical absorption and electron paramagnetic resonance (EPR) spectra of VO²⁺ in NaHC₂O₄?·?H₂O single crystals were performed using the complete diagonalization energy matrix method (CDM) and the perturbation theory method (PTM) for the 3d ¹ electronic configuration. The calculated results are in good agreement with experimental results. The negative signs of hyperfine structure constants A _∥ and A _⊥ for VO²⁺ in NaHC₂O₄·H₂O single crystals are suggested from the calculations. Comparison of the two calculation methods indicates that the PTM is a good approximation of CDM and that both theoretical methods are valid in interpretation of the optical and EPR spectra for VO²⁺ ions in NaHC₂O₄?·?H₂O crystals.     

With a letter-searched prime, boat primes float but swim and coat don't: further evidence for automatic semantic activation

Letter search (LS) on the prime typically eliminates semantic priming (swim-float) and orthographic/phonological (O/P) priming (coat-float) but not morphological priming (marked-mark). However, LS on the prime does not reduce semantic priming for low-frequency targets (Tse & Neely, 2007). These findings suggest that semantic activation survives LS but decays during LS to a low level that can be detected only with sensitive measures, which are afforded by low-frequency targets and morphologically related primes and targets. In the present research, we show that LS on the prime results in 0 msec of semantic priming (e.g., swim-float) and 11 msec of O/P priming (e.g., coat-float), both of which are statistically null, whereas the LS semantic+O/P priming effect for primes and targets that do not share a morpheme (e.g., boat-float) is a robust 37 msec. Discussion focuses on the automaticity of semantic activation and whether morphological priming is mediated by (1) a morphemic representation that is separate from semantic representations or (2) activation combined from semantics and orthography/phonology.     

Metacognition as a Moderator of Creative Ideation and Creative Production

Recent theoretical work has called for exploration of the moderating effects of cognitive factors on the relationship between creative ideation and creative production. The Cognitive-Creative Sifting model suggests skills in processing and transforming information influence the association. This study used the Runco Ideational Behavior Scale, Metacognitive Awareness Inventory, and Creative Behavior Inventory to test the moderating effect. Medium to large moderator effects (f² = .015 to f² = .041) were observed across previous theoretically proposed aspects of metacognition. A large, statistically significant moderator effect was observed for overall metacognition (f² = .031). Observed differences across subcomponents of metacognition paralleled theoretical connections between metacognition and creativity. Further studies are suggested using more diverse creativity measures, as well as tests for other cognitive sifters. Implications for educational practice, particularly regarding the creatively gifted, are offered.     

The temperature dependence of the optical dispersion parameters in Si and Ge

Abstract

In Si and Ge, the optical dispersion parameters (single-oscillator energy E_o , dispersion energy E_d and bond energy gap E_g developed by Wemple and DiDomenico, and Phillips) have been analysed in the temperature range 100-300 K using data obtained by Icenogle et al. E_o and E_g exhibit a very small temperature dependence in both materials. The thermal coefficients of the dispersion energy, dE_d/dT, have opposite signs (Si, –41·9 × 10^?4eVK^?1; Ge, +37·7 × 10^?4eVK^?1).     

Analysis of Interactions and Nonlinear Effects with Missing Data: A Factored Regression Modeling Approach Using Maximum Likelihood Estimation

Abstract

When estimating multiple regression models with incomplete predictor variables, it is necessary to specify a joint distribution for the predictor variables. A convenient assumption is that this distribution is a multivariate normal distribution, which is also the default in many statistical software packages. This distribution will in general be misspecified if predictors with missing data have nonlinear effects (e.g., x²) or are included in interaction terms (e.g., x·z). In the present article, we introduce a factored regression modeling approach for estimating regression models with missing data that is based on maximum likelihood estimation. In this approach, the model likelihood is factorized into a part that is due to the model of interest and a part that is due to the model for the incomplete predictors. In three simulation studies, we showed that the factored regression modeling approach produced valid estimates of interaction and nonlinear effects in regression models with missing values on categorical or continuous predictor variables under a broad range of conditions. We developed the R package mdmb, which facilitates a user-friendly application of the factored regression modeling approach, and present a real-data example that illustrates the flexibility of the software.     

Psychosocial mediators of a theory-based resistance training maintenance intervention for prediabetic adults

Objective: Examine psychosocial mediators of the effects of high vs. low-dose resistance training (RT) maintenance interventions among older (ages 50–69), overweight and pre-diabetic adults.

Design: Participants (N = 123) completed a three-month supervised RT initiation phase and were subsequently randomised (time 1) to high or low-dose six-month unsupervised RT maintenance interventions (time 2), followed by a six-month no-contact phase (time 3).

Main Outcome Measures: Online measures of putative mediators and RT behaviour.

Results: RT intervention condition (high vs. low dose) had significant effects on change from time 1 to time 2 in behavioural expectation, self-regulation and perceived satisfaction (f² = .04–.08), but not outcome expectancies, RT strategies or behavioural intentions (f² ≤ .02). Change in each of the putative mediators, except for outcome expectancies (f² ≤ .02), had significant effects on RT behaviour at times 2 (f² = .12–.27) and 3 (f² = .23–.40). In a multiple mediation model, behavioural expectation (f² = .11) and self-regulation (f² = .06) mediated the effects of RT intervention condition on time 2 RT behaviour, whereas perceived satisfaction did not (f² = .01). Self-regulation was a significant mediator of intervention effects on time 3 RT behaviour (f² = .11), but behavioural expectation and perceived satisfaction were not (f² = .04).

Conclusions: Findings suggest that behavioural expectation and self-regulation are appropriate targets for RT maintenance interventions among at-risk older adults.     

Defect analysis of Fe3(Al1– x Si x ) alloys by positron-lifetime spectroscopy

The recovery behaviour of vacancy-type defects created at 1000°C in Fe₃(Al_{1– x} Si _x ) alloys has been investigated by positron-lifetime measurements in samples cooled to room temperature by water quenching, air quenching and furnace cooling. In addition, a set of samples was aged for one week at 520°C. After water quenching, measurements reveal a high concentration of thermal vacancies, and from the decrease of the average positron lifetime it is inferred that vacancy recovery is strongly composition-dependent. Greater decreases of the positron lifetime were found for Si-rich samples, suggesting diffusion enhancement as the Si concentration increases. For the Fe₃Al alloy, the retained vacancy concentration depends strongly on the cooling rate. This is related to atomic ordering and a rebuilding of the D0₃ structure.     

Pressure-Induced transitions in amorphous TlxSe100−x alloys

Abstract

The electrical resistivity of bulk semiconducting amorphous Tl_xSe_100?x alloys with 0 ≤ x ≤ 25 has been investigated up to a pressure of 14 GPa and down to liquidnitrogen temperature by use of a Bridgman anvil device. All the glasses undergo a discontinuous pressure-induced semiconducting-to-metal transition. X-ray diffraction studies on the pressure-recovered samples show that the high-pressure phase is the crystalline phase. The pressure-induced crystalline products are identified to be a mixture of Se having a hexagonal structure with a = 4·37 Å and c = 4·95 Å and TlSe having a tetragonal structure with a = 8·0 Å and c = 7·0 Å     

Teachers’ Perceptions of Creativity in the Classroom

Teachers’ implicit understandings of creativity may not align with current research-based understanding of creativity and characteristics associated with creative students. Even teachers who say they value creativity may actually find creative characteristics undesirable. Participating teachers (n = 371) rated student characteristics on a scale of very undesirable to very desirable. Participants also completed a brief self-assessment of personal creativity and rank-ordered a set of educational objectives based on what they perceived as most important. Results indicated that teachers found student characteristics associated with creativity less desirable than those characteristics contraindicative to creativity (d = 2.70). No effects were found based on the grade level (d = 0.07) and small effects were found for subjects taught (η² = 0.023). Similarly, no effects were found for the teachers’ level of experience (η² = 0.004) or age (η² = 0.002). Teachers’ level of personal creativity was related (r = .248) to how desirable they rated student characteristics associated with creativity, but the importance with which teachers ranked creative thinking had small effects (η² = 0.04) on how desirable they found characteristics associated with creativity. These results generally confirm previous studies and suggest that teachers’ grade level, subject, experience, and age have no effect on their perception of creative characteristics. However, some evidence suggests that teachers who are more creative find student characteristics associated with creativity more desirable in class.     

On Properties and Processes on Numerical Assignment: An Empiricist Approach

By starting from the idea of processes of numerical assignment, an explication, á la Kant, of the concept of property is proposed. In this way two results are achieved: on the one hand, the Kantian doctrine of explication is revaluated; on the other hand, the notion of property is tackled from an empiricist point of view based on the representational theory of measurement. This revised version was published online in August 2006 with corrections to the Cover Date.     

Vocal fundamental and formant frequencies affect perceptions of speaker cooperativeness

In recent years, the perception of social traits in faces and voices has received much attention. Facial and vocal masculinity are linked to perceptions of trustworthiness; however, while feminine faces are generally considered to be trustworthy, vocal trustworthiness is associated with masculinized vocal features. Vocal traits such as pitch and formants have previously been associated with perceived social traits such as trustworthiness and dominance, but the link between these measurements and perceptions of cooperativeness have yet to be examined. In Experiment 1, cooperativeness ratings of male and female voices were examined against four vocal measurements: fundamental frequency (F₀), pitch variation (F₀?SD), formant dispersion (D_f), and formant position (P_f). Feminine pitch traits (F₀ and F₀?SD) and masculine formant traits (D_f and P_f) were associated with higher cooperativeness ratings. In Experiment 2, manipulated voices with feminized F₀ were found to be more cooperative than voices with masculinized F₀^, among both male and female speakers, confirming our results from Experiment 1. Feminine pitch qualities may indicate an individual who is friendly and non-threatening, while masculine formant qualities may reflect an individual that is socially dominant or prestigious, and the perception of these associated traits may influence the perceived cooperativeness of the speakers.     

Experimental evidence of relaxation arising from the motion of geometrical kinks on screw dislocations in iron

Abstract

Internal friction measurements with a superimposed bias stress have provided evidence for geometrical kink migration on screw dislocations in iron. This intrinsic process causes a relaxation phenomenon in internal friction which has been identified with the occurrence of a subpeak (below 20 K) of the α-peak. The effect of different bias stress has allowed us to evaluate the kink migration energy, E ^m _k ? 0·001eV.     

Near-infrared transitions of LiNdP4O12 and LiErYP4O12

Abstract

Fluorescence transitions in LiNdP₄O₁₂: ⁴ F_3/2→⁴I_9/2 (0·90μm), ⁴F_3/2→⁴I_11/2 (1·05μm), ⁴F_3/2→⁴I_13/2 (1·32μm), ⁴F_3/2→⁴I_15/2 (1·77μm), and in LiErYP₄O₁₂: ⁴S_3/2→⁴I_11/2 (1·3μm), ⁴I_13/2→⁴I_15/2 (1·53μm), have been obtained at room temperature. The positions of the energy levels related to the excitation, nonradiative and radiative processes have been established from complementary absorption measurements. The fluorescence lifetimes of the above-mentioned transitions have been determined from single exponential decays.     

Effects of a prevention program for divorced families on youth cortisol reactivity 15 years later

Objective: We examined whether an empirically based, randomised controlled trial of a preventive intervention for divorced mothers and children had a long-term impact on offspring cortisol regulation.

Design: Divorced mothers and children (age 9–12) were randomly assigned to a literature control condition or the 11-week New Beginnings Program, a family-focused group preventive intervention for mothers and children in newly divorced families.

Main Outcome Measures: Fifteen years after the trial, offspring salivary cortisol (n = 161) was measured before and after a social stress task.

Results: Multilevel mixed models were used to predict cortisol from internalizing symptoms, externalizing symptoms, group assignment and potential moderators of intervention effects. Across the sample, higher externalizing symptoms were associated with lower cortisol reactivity. There was a significant group-by-age interaction such that older offspring in the control group had higher reactivity relative to the intervention group, and younger offspring in the control group exhibited a decline across the task relative to younger offspring in the intervention group.

Conclusions: Preventive interventions for youth from divorced families may have a long-term impact on cortisol reactivity to stress. Results highlight the importance of examining moderators of program effects.     

Ghrelin level negatively predicts quality of life in obese women

A cross-sectional cohort study was conducted to investigate whether ghrelin level in obese women predicts the quality of life (QOL). A total of 307 subjects fulfilled the criteria: (1) age between 20 and 65 years old, (2) body mass index ≥27 kg/m² (3) waist circumference ≥80 cm were enrolled in the study. All subjects were assigned to one of the plasma ghrelin level categories according to the quartiles. The median of age and BMI of the 307 obese women were 45 ± 18 years and 29.9 ± 4.1 kg/m², respectively. The main outcome evaluated is the associations of plasma ghrelin level and QOL, which were evaluated using multiple linear regression analysis. Results of linear trend test show significant statistical difference in plasma lipoproteins (triglyceride, cholesterol, HDL-cholestero and LDL-cholesterol = and levels of obesity-related hormone peptides, including leptin, adiponectin, insulin among quartiles of ghrelin. Multiple liner regression analysis of serum obesity-related hormone peptide level and QOL using stepwise method shows ghrelin concentration was the only predictor of QOL, including PCS-12 level (β = ?0.18, p = 0.001), MCS-12 level (β = ?0.14, p = 0.009), WHOQOL-BREF scores: physical (β = ?0.13, p = 0.03), psychological (β = ?0.16, p = 0.007), social (β = ?0.21, p?= < 0.001), and environmental (β = ?0.22, p?= <0.001), after adjusting other factors for obese female subjects. This study demonstrated that ghrelin concentration is strongly associated with QOL level among obese women. Hence, ghrelin concentration might be a valuable marker to be monitored in obese women.     

A Note on the Comparative Value of the “True” Index of Studiousness for the Purpose of Prognosis

It was hypothesized that observers would be less inclined to expect a person to shift from one task to another when the initial task had been chosen than when it had been assigned, and when costs incurred while working on the initial task could not be recouped. Choice was also hypothesized to favor attribution of preference for the initial task and optimism concerning its completion, while unrecoupable costs were expected to encourage the attribution of preference but inhibit the attribution of optimism. It was also hypothesized that the effects of choice on attributed preference and optimism would be negated by the individual's failure to shift tasks at the earliest opportunity, but the effects of unrecoupable costs would not be. Ss were 188 male undergraduates who twice responded to paper-and-pencil instruments while watching video-taped experimental sessions. The manipulations created a 2 × 2 × 2 design. All hypotheses were supported. It was concluded that unrecoupable costs establish a strong and lasting presumption of commitment, whereas the effects of choice vs. assignment tend not to persist in the face of contradictory evidence.     

Differential Method of Characterizing Gait Strategies From Step Lengths and Frequencies: Strategy of Velocity Modulation

The differential method consists of the analysis of the variation of gait parameters length, frequency, and velocity with respect to their mean values, respectively, ΔL = L — L_m , Δf = f — f_m , and Δv = v – v_m , where L_m , f_m , and v_m represent the mean values of those parameters. Assuming that the strategy of modulation of velocity implies that L and f are functions of v and that statistical analyses of ratios ΔL/Δv and Δf/Δv have established that there is a very significant linear correlation, close to 1, between those ratios, the mathematical procedure allows one to determine the equation of step length, L = a · f + b · v + K, where a and b are the slope and the intercept of the linear regression and K is close to L_m . The equation was experimentally tested on 140 gait sequences performed by 6 participants and for gait velocities ranging from 0.6 to 2.2 m/s and was found to be very representative of all individual values. The differential method provides another way of using the derivative of velocity, v = L·f, to characterize the strategy of velocity modulation, which then permits one to determine the linear equation of velocity, v = f · L_m + L · f_m — L_m · f_m , and to show that the respective parts played by each parameter in the progression velocity are approximately equal. The author establishes the uniqueness of the different linear adjustments and discusses the differential method's own modes of use, that is, interindividually or globally.     

A Propensity Score Adjustment for Multiple Group Structural Equation Modeling

In the behavioral and social sciences, quasi-experimental and observational studies are used due to the difficulty achieving a random assignment. However, the estimation of differences between groups in observational studies frequently suffers from bias due to differences in the distributions of covariates. To estimate average treatment effects when the treatment variable is binary, Rosenbaum and Rubin (1983a) proposed adjustment methods for pretreatment variables using the propensity score. However, these studies were interested only in estimating the average causal effect and/or marginal means. In the behavioral and social sciences, a general estimation method is required to estimate parameters in multiple group structural equation modeling where the differences of covariates are adjusted. We show that a Horvitz–Thompson-type estimator, propensity score weighted M estimator (PWME) is consistent, even when we use estimated propensity scores, and the asymptotic variance of the PWME is shown to be less than that with true propensity scores. Furthermore, we show that the asymptotic distribution of the propensity score weighted statistic under a null hypothesis is a weighted sum of independent χ² ₁ variables. We show the method can compare latent variable means with covariates adjusted using propensity scores, which was not feasible by previous methods. We also apply the proposed method for correlated longitudinal binary responses with informative dropout using data from the Longitudinal Study of Aging (LSOA). The results of a simulation study indicate that the proposed estimation method is more robust than the maximum likelihood (ML) estimation method, in that PWME does not require the knowledge of the relationships among dependent variables and covariates.     

A new allotropic structure of silver nanocrystals nucleated and grown over planar polymer molecules

Polymer molecules of polyvinyl alcohol (PVA) serve as a good Ag⁺?→?Ag⁰ reducer as well as a template to produce Ag⁰ nanocrystals of anisotropic shapes. Thin Ag–PVA films (50–100?µm thick) were prepared by carrying out the reaction in aqueous PVA (under heating conditions) and then spin casting the sample in this shape. A topotactic Ag⁺?→?Ag⁰ reaction and in-situ Ag⁰ growth occur in support over the PVA molecules (as per the local structure and Ag⁰–PVA interactions) of elongated surfaces. The Ag⁰ state is confirmed with 3d _5/2 and 3d _3/2 XPS signals of 368.37 and 374.13?eV binding energies, respectively. As analyzed with X-ray diffraction, it is a new allotrope with an orthorhombic structure, lattice parameters a?=?0.8535, b?=?0.8410?nm and c?=?0.4119?nm, and density ρ?=?9.69?g?cm^?3. On heating in air, the well-known cubic structure develops, a?=?0.4082?nm (ρ?=?10.53?g?cm^?3) after 150°C, whereas a?=?0.4071?nm (ρ?= 10.61?g?cm^?3) after 300°C for 2?h. According to proposed models, it is a vacancy-stabilized allotrope, which evolves from multiply twinned particles.