Mechanical spectroscopy of a high-Nb-bearing γ-TiAl-based alloy with near-gamma and fully lamellar microstructure

Intermetallic γ-TiAl sheet material of composition Ti–46?at.%Al–9?at.%Nb and two different microstructures (fine-grained near-gamma and coarse-grained fully lamellar) was studied by mechanical-loss (internal-friction) measurements using two frequency ranges: (I) 0.01–10?Hz and (II) around 2?kHz. The mechanical spectra in range I show (i) a loss peak of Debye type at T?≈?1000?K, which occurs only in fully lamellar samples; and (ii) a high-temperature damping background above?≈?1100?K. The values of the activation enthalpy H of the high-temperature background, 4.3?eV (near-gamma) and 4.2?eV (fully lamellar), which were determined from the frequency shift, are distinctly higher than those obtained for TiAl sheet material with low Nb content. The high-temperature damping background is assigned to diffusion-assisted climb of dislocations, and the 1000?K peak (H?=?2.9?eV) to local (reversible) glide of dislocation segments anchored between lamella interfaces. From measurements of the eigenfrequency in range II, the variation of Young's modulus in the temperature range 300–1000?K was determined.     

Biological maturation and physical activity in adolescent British females: The roles of physical self-concept and perceived parental support

ObjectivesThis study examined the mediating and moderating effects of physical self-concept and parental support, respectively, on relations between maturation and physical activity (PA) in British adolescent females.DesignCross-sectional field based study.MethodsBiological maturity status, physical self-concept, perceived parental support for PA, and self-reported PA were assessed in 244 female British year 7–9 pupils (M age = 12.8 years, SD = .9).ResultsStructural equation modelling, employing maximum likelihood estimation and boot-strapping procedures supported the contention that physical self-concept mediated an inverse relation between maturation and PA. A regression model examining the main and interactive effects of maturation and parental support on PA provided evidence of a main effect for parental support, but no interactive effect.ConclusionsThe results suggest that physical self-concept partially mediates an inverse relation between maturity and physical activity in adolescent females. Accordingly, how adolescent females interpret or perceive the changes associated with maturation may be more important than maturation itself. Encouraging adolescent females to view puberty as a natural and attractive aspect of the process of ‘growing up’ may help mitigate any negative health consequences associated with early maturation. Parental support for PA does not appear to moderate relations between maturation and PA.     

Assessing individual differences in achievement motivation with the Implicit Association Test

The authors examined the validity of an Implicit Association Test (Greenwald, McGhee, & Schwartz, 1998) for assessing individual differences in achievement tendencies. Eighty-eight students completed an IAT and explicit self-ratings of achievement orientation, and were then administered a mental concentration test that they performed either in the presence or in the absence of achievement-related feedback. Implicit and explicit measures of achievement orientation were uncorrelated. Under feedback, the IAT uniquely predicted students’ test performance but failed to predict their self-reported task enjoyment. Conversely, explicit self-ratings were unrelated to test performance but uniquely related to subjective accounts of task enjoyment. Without feedback, individual differences in both performance and enjoyment were independent of differences in either of the two achievement orientation measures.     

Are country level prevalences of rule violations associated with knowledge overclaiming among students?

Cultural norms of behaviour influence desirable and problematic behaviours of individuals. In particular, cultural norms should influence individuals' dishonesty. In a recent Nature study, prevalence of rule violations was introduced as a new country‐level measure of behavioural norms. However, information on individuals' actual honesty was not available due to characteristics of the experimental design. Overcoming this limitation, we show that country‐level behavioural norms are related to individual‐level knowledge overclaiming behaviour (i.e., claiming to know concepts that do not exist, a measure of individuals' actual behavioural dishonesty) among 290,954 students from 57 countries (from the 2012 PISA study). Our study represents a crucial test of the argument that cultural norms influence individual's behaviour and of the validity of the measurement of countries' prevalences of rule violations. These results imply that shaping the behaviour of today's students may result in new behavioural norms that emphasise honesty and rule adherence more strongly.     

Who Reaps the Benefits of Social Change? Exploration and Its Socioecological Boundaries

We investigated the interplay between the personality trait exploration and objective socioecological conditions in shaping individual differences in the experience of two individual‐level benefits of current social change: new lifestyle options, which arise from the societal trend toward individualization, and new learning opportunities, which accrue from the societal trend toward lifelong learning. We hypothesized that people with higher trait exploration experience a greater increase in lifestyle options and learning opportunities––but more so in social ecologies in which individualization and lifelong learning are stronger, thus offering greater latitude for exploring the benefits of these trends. We employed structural equation modeling in two parallel adult samples from Germany (N = 2,448) and Poland (N = 2,571), using regional divorce rates as a proxy for individualization and Internet domain registration rates as a proxy for lifelong learning. Higher exploration was related to a greater perceived increase in lifestyle options and in learning opportunities over the past 5 years. These associations were stronger in regions in which the trends toward individualization and lifelong learning, respectively, were more prominent. Individuals higher in exploration are better equipped to reap the benefits of current social change––but the effects of exploration are bounded by the conditions in the social ecology.     

Die posthume Begutachtung der Testierfähigkeit

Based upon German law and jurisdiction, forensic-psychiatric literature as well as the author’s experiences, essential criteria for the assessment of testamentary capacity are presented, peculiarities of the posthumous assessment of psychopathology are explained, and common sources of error are discussed.     

Comparative judgments with missing information: a regression and process tracing analysis

We had participants decide which one of two applicants was better qualified for a scholarship. They also judged the difference between them (comparative judgment). The applicants were described by features (grades) in different subjects (dimensions). The grades on some dimensions were missing (unique dimensions) for an alternative while all the grades were available on other dimensions (common dimensions). In a conventional regression analysis, we found that decision makers gave more weight to dimensions when they were common than when they were unique. However, this commensurability effect was limited to medium important dimensions and did not apply to dimensions of high or low importance. We also observed how participants retrieved information for the choice alternatives and analysed how importance and commensurability are reflected in the processing prior to the decision. Features on more important or common dimensions were inspected earlier than features on less important or unique dimensions. Participants preferred dimensional transitions and inspected features on unique dimensions longer than their common counterparts. This finding suggested that participants used inferences when features were missing. We propose an outline of a decision heuristic to describe decision making with missing information.     

Stress on the dance floor: the cortisol stress response to social-evaluative threat in competitive ballroom dancers

The social self-preservation theory states that humans have a fundamental motivation to preserve the social self and that threats to the social self perturb biological markers such as cortisol. Five studies were designed to examine the cortisol response to competitive ballroom dancing as a paradigm for real-life social-evaluative threat. Competitive dancing produced substantial increases in cortisol compared to a control day. These increases were not due to the physical strain of dancing and were greater than those found during social-evaluative laboratory stressors. Responses did not habituate across competitions and were mostly elevated under highly focused conditions of threat (couple vs. group competition). These findings support the notion of a social self-preservation system that is physiologically responsive to threats to the social self.