Taste transduction: Linkage between molecular mechanisms and psychophysics

Taste transduction is initiated when taste stimuli interact with receptor sites on the exposed apical microvilli of receptor cells. The interaction leads to an increase in intracellular Ca⁺⁺ and transmitter release from the taste cell. Recent studies have revealed that taste cells utilize a diversity of mechanisms for transduction. Ionic taste stimuli, such as salts and acids, interact directly with apically located ion channels to depolarize taste cells. In contrast, amino acids, sweeteners and most bitter tasting stimuli bind to specific membrane receptors that are usually coupled to G proteins and second messenger systems. This review summarizes recent progress in understanding the initial events in taste transduction. Commonalities of molecular mechanisms for different taste stimuli may help explain psychophysical interactions of taste stimuli.     

Performance in a tool-using task by common chimpanzees (Pan troglodytes), bonobos (Pan paniscus), an orangutan (Pongo pygmaeus), and capuchin monkeys (Cebus apella).

Performance by individual animals of three species of great apes (Pan troglodytes, Pan paniscus, and Pongo pygmaeus) and capuchin monkeys (Cebus apella) was assessed by presenting a food treat inside a clear tube. The subjects readily used a straight stick to obtain the food. When sticks were bundled together, the apes immediately unwrapped the bundle to obtain an individual stick, whereas capuchins attempted to insert the bundled sticks. When a misshapen stick was provided, apes, but not capuchins, showed an improvement in terms of modifying the misshapen stick before insertion. Our results indicate that all these species can solve these tasks. However, only the performance of apes is consistent with emerging comprehension of the causal relations required for the avoidance of errors in the more complex tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual concommitants of racial attitudes in urban grade-school children.

Investigated children's racial attitudes and their concomitant perceptual responses in a 2-part study. In Phase 1, a total of 400 2nd, 4th and 6th graders at 2 racially integrated urban elementary schools were given a battery of 4 attitude tests (e.g., the Projective Prejudice Test). In Phase 2, a subsample of 96 Ss were classified into high- and low-prejudice groups on the basis of attitude scores and judged the similarity of pictures of facial pairs. Stimuli varied as to color, shade, expression, and hair type. A 4-way factorial design was employed (Grade * Prejudice Level * Race of Subject * Race of Examiner). Findings indicate that the various ways of assessing Ss' racial attitudes were not equivalent. Some instruments were strongly affected by developmental and racial factors, whereas others were not. Correlations between indices were low. Findings in Phase 2 indicated that racial attitudes do have perceptual correlates, particularly for white children. Race-related cues were accentuated by high-prejudice children, whereas non-race-related ones were less salient. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Clients' demographic characteristics and therapeutic treatment: Differences that make a difference.

Studied the relationship between clients' demographic characteristics (age, sex, education, income, marital status, and ethnicity) and services received (diagnosis, type of treatment, type of personnel rendering services, and type of therapy and number of sessions). Ss were 1,190 White and 1,294 minority-group community mental health center clients. Client attributes were related to services rendered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Delivery of community mental health services to black and white clients.

Compared services rendered to 959 black and 11,904 white clients seen at 17 community mental health centers. Data included client's age, sex, income, education, marital status, diagnosis, assignment to type of treatment program, major service received, number of contacts, and assignment to type of therapist. Results indicate that the 959 blacks compared to a 10% random sample of 1,190 whites (a) represented a different group of clients in demographic characteristics, (b) were no more likely to receive inferior forms of treatment programs, (c) saw paraprofessional rather than professional personnel, and (d) failed to return after the initial contact at a high rate (i.e., over 50% terminated at this time). The latter 2 findings persisted irrespective of other demographic differences between blacks and whites. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The minimal dimension of stable faces required to guaranteestability of a matrix polytope

Considers the problem of determining whether each point in a polytope n×n matrices is stable. The approach is to check stability of certain faces of the polytope. For n⩾3, the authors show that stability of each point in every (2n-4)-dimensional face guarantees stability of the entire polytope. Furthermore, they prove that, for any k⩽n², there exists a k-dimensional polytope containing a strictly unstable point and such that all its subpolytopes of dimension min {k-1,2n-5} are stable     

An LCOS‐based digital‐cinema projector

Abstract— A digital cinema projector that utilizes three JVC QXGALCDs, and provides 12,000 lumens, 2000:1 contrast, and 3‐Mpixel resolution was developed. This system, which was described in a prior paper (see Ref. 10), has a novel optical configuration based on the use of intermediate imaging optics and wire‐grid polarizers and is described in greater detail in this paper. The polarization optics, including the polarization compensators, contribute to a system that provides high contrast at a low f/#, with a wide color gamut and minimal color shading at high power.     

Perceptions of racial microaggressions among black supervisees in cross-racial dyads.

Perceived racial microaggressions by White supervisors were examined through a qualitative analysis of 10 self-identified Black doctoral supervisees in counseling and clinical psychology. Results indicated 7 microaggression themes directed toward this group: (a) invalidating racial-cultural issues, (b) making stereotypic assumptions about Black clients, (c) making stereotypic assumptions about Black supervisees, (d) reluctance to give performance feedback for fear of being viewed as racist, (e) focusing primarily on clinical weaknesses, (f) blaming clients of color for problems stemming from oppression, and (g) offering culturally insensitive treatment recommendations. The impact of these racial microaggressions was found to be detrimental to Black trainees, the supervisory relationship, and, indirectly, to clients of color. Implications of the findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)