Teachers' brief nonverbal behaviors in defined instructional situations can predict students' evaluations.

Can a few seconds of high school teachers' nonverbal (NV) behavior predict students' ratings of these teachers (SRT)? Yes, but NV-SRT relations varied among various instructional situations. NV behaviors while administering the class and using the board were unrelated to SRT. Positive judgments of NV behavior while disciplining the class and interacting with students were positively related to SRT. NV behaviors in frontal teaching were negatively related to SRT. The most negative NV-SRT relations were found for teachers' differential NV behavior toward high- versus low-achieving students. Teacher differentiality and SRT have rarely been investigated in high school. The structure of SRT seems to differ between high school and college, and students' anger about teachers' differentiality strongly predicted their evaluations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Controlled linear perturbation

We present an algorithmic solution to the robustness problem in computational geometry, called controlled linear perturbation, and demonstrate it on Minkowski sums of polyhedra. The robustness problem is how to implement real RAM algorithms accurately and efficiently using computer arithmetic. Approximate computation in floating point arithmetic is efficient but can assign incorrect signs to geometric predicates, which can cause combinatorial errors in the algorithm output. We make approximate computation accurate by performing small input perturbations, which we compute using differential calculus. This strategy supports fast, accurate Minkowski sum computation. The only prior robust implementation uses a less efficient algorithm, requires exact algebraic computation, and is far slower based on our extensive testing.     

The Psychological Price of Media Bias.

Media bias was investigated through the effects of a TV interviewer's preferential behavior on the image of the interviewee in the eyes of the viewers. Judges viewed a political interview with either a friendly or a hostile interviewer then rated their impressions of the interviewed politician, whose behavior was identical in all conditions. The preferential nonverbal behavior of the interviewer (controlling for recognition and comprehension of verbal content) systematically influenced viewers' ratings of the politician. The effect consisted mainly of damage to the politician in the hostile interviewer condition. Describing the interviewee as a professor yielded a similar preferential behavior effect. A strong halo effect was identified, but it was ruled out as the mechanism accounting for the interviewer effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pygmalion, Galatea, and the Golem: Investigations of biased and unbiased teachers.

Examined differential expectancy effects as a function of teachers' susceptibility to biasing information and the distinction between positive ("Galatea") and negative ("Golem") outcomes of teacher expectancies. 26 biased and unbiased student teachers were identified on the basis of their susceptibility to biasing information in scoring drawings allegedly made by high- or low-status students. High-bias teachers treated the students they perceived to be of low potential negatively while at the same time treating randomly selected students in a manipulated high-expectancy group as favorably as they treated the students they themselves nominated as being of high potential. Unbiased teachers treated all 3 groups of students (N?=?202) equitably. The strongest and most consistent Golem effects were observed for behavioral manifestations of dogmatism. These patterns of differential negative expectancy effects were evident not only in teachers' behavior but also in students' actual performance of specially designed tasks. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The teacher's pet phenomenon: Rate of occurrence, correlates, and psychological costs.

The teacher's pet phenomenon was investigated in 80 5th-grade Israeli classrooms. Pets were identified through students' sociometric nominations in 80% of the classrooms: exclusive pets in 26% and unexclusive pets in 54% of the classrooms. Pets tended to be girls rather than boys, of Ashkenazi rather than Sephardi origin, very good (but not necessarily the best) students academically, and perceived as charming, socially skilled, and compliant. Teachers who had pets were found to hold somewhat more authoritarian attitudes than teachers who did not have pets, and the rate of occurrence of the pet phenomenon was higher in religious than in secular schools. Students' affective reactions to their teachers were more positive in classrooms without pets, and most negative in exclusive-pet classrooms. Potential favoritism in assigning teacher grades to exclusive pets was also investigated: No overall favoritism was found, but a trace of favoritism by more authoritarian teachers was discovered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Topochemical manipulation of perovskites: low-temperature reaction strategies for directing structure and properties

Topochemical reaction strategies offer an important low-temperature (<500 °C) approach to the conscious manipulation of various inorganic host materials, allowing access to compounds that cannot be prepared by standard high-temperature methods. As the utility of these strategies continues to expand, researchers will be able to more effectively target materials with technologically significant properties. This Progress Report presents recent advances in topochemical reaction strategies as applied to perovskite and perovskite-related compounds. Emphasis is placed on structural modifications and corresponding variations in properties. Additionally, the future prospects of this approach to the rational design of intricate target compounds are discussed.     

Self-generated drug outcomes in high-risk adolescents.

The perceived outcomes of drug use were studied in a sample of high-risk adolescents. Participants' self-generated responses provided the actual words they used to describe drug outcomes as well as associative frequency norms valuable for future research. The authors also compared outcomes in terms of class of outcome (positive vs. negative) and class of drug (alcohol, marijuana, cigarettes, cocaine, speed, and LSD). Although the studied drugs have divergent pharmacological effects. participants self-generated some of the same outcomes (e.g., relaxation) across some of the drugs. In addition, outcomes self-generated as positive outcomes were very rarely also self-generated as negative outcomes. Finally, regressions revealed that self-generated responses were not predicted by ethnicity, gender, or previous drug use. Many drug use outcomes thus appeared to be available in memory regardless of previous drug use or other characteristics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Room temperature oxidative intercalation with chalcogen hydrides: Two-step method for the formation of alkali-metal chalcogenide arrays within layered perovskites

A two-step topochemical reaction strategy utilizing oxidative intercalation with gaseous chalcogen hydrides is presented. Initially, the Dion-Jacobson-type layered perovskite, RbLaNb₂O₇, is intercalated reductively with rubidium metal to make the Ruddlesden-Popper-type layered perovskite, Rb₂LaNb₂O₇. This compound is then reacted at room-temperature with in situ generated H₂S gas to create RbS layers within the perovskite host. Rietveld refinement of X-ray powder diffraction data (tetragonal, a = 3.8998(2) Å, c = 15.256(1) Å; space group P4/mmm) shows the compound to be isostructural with (Rb₂Cl)LaNb₂O₇ where the sulfide resides on a cubic interlayer site surrounded by rubidium ions. The mass increase seen on sulfur intercalation and the refined S site occupation factor (～0.8) of the product indicate a higher sulfur content than expected for S^2? alone. This combined with the Raman studies, which show evidence for an HS stretch, indicate that a significant fraction of the intercalated sulfide exists as hydrogen sulfide ion. Intercalation reactions with H₂Se_(g) were also carried out and appear to produce an isostructural selenide compound. The utilization of such gaseous hydride reagents could significantly expand multistep topochemistry to a larger number of intercalants.