Fast photochemical oxidation of proteins for comparing structures of protein-ligand complexes: the calmodulin-peptide model system

Fast photochemical oxidation of proteins (FPOP) is a mass spectrometry-based protein footprinting method that modifies proteins on the microsecond time scale. Highly reactive (?)OH, produced by laser photolysis of hydrogen peroxide, oxidatively modifies the side chains of approximately one-half the common amino acids on this time scale. Because of the short labeling exposure, only solvent-accessible residues are sampled. Quantification of the modification extent for the apo and holo states of a protein-ligand complex provides structurally sensitive information at the amino-acid level to compare the structures of unknown protein complexes with known ones. We report here the use of FPOP to monitor the structural changes of calmodulin in its established binding to M13 of the skeletal muscle myosin light chain kinase. We use the outcome to establish the unknown structures resulting from binding with melittin and mastoparan. The structural comparison follows a comprehensive examination of the extent of FPOP modifications as measured by proteolysis and LC-MS/MS for each protein-ligand equilibrium. The results not only show that the three calmodulin-peptide complexes have similar structures but also reveal those regions of the protein that became more or less solvent-accessible upon binding. This approach has the potential for relatively high throughput, information-dense characterization of a series of protein-ligand complexes in biochemistry and drug discovery when the structure of one reference complex is known, as is the case for calmodulin and M13 of the skeletal muscle myosin light chain kinase, and the structures of related complexes are not.     

Growth of germanium nanowires on silicon(111) substrates by molecular beam epitaxy

Heteroepitaxial growth of Ge nanowires was carried out on Si(111) substrates by MBE. Au seeds were used as precursor for the VLS growth of the nanowires. Even if the Au droplets do not act as catalyst for the dissociation of gas, they are local preferential areas where the energetic barrier of Ge nucleation is lowered compare to the remaining non activated surface. Two sets of Au seeds were used as precursors for the VLS process. The first set have an average diameter of 125 nm and the second of 25 nm. In-situ RHEED monitoring showed a Au wetting layer between these seeds before the nanowires growth as well as at the end of the Ge nanowires growth. It means that the wetting layer acted as a surfactant from the Si(111) surface to the Ge grown layer between the nanowires. Analysis of SEM images brought the fact that the diffusion of gold from the droplets on the surface and the sidewalls of the nanowires via the Ostwald ripening is a key parameter of the growth of the nanowires.     

Multicriteria DSS with Historical Database for Attenuator Selection

A computerized information system has been developed for the management of field data on vehicle impacts with crash attenuators. The system has been developed for an intranet platform with a Java-based interface. A central Oracle database contains a variety of data describing site conditions, maintenance history, and accident characteristics. Several standard reports can be generated, summarizing attenuator usage, life-cycle costs, and accident outcomes under a variety of site or crash conditions. In addition, a multicriteria decision support system uses historical data to rank attenuators based on their past performance under specific site conditions. This application supports the design and selection of attenuators for new locations; it can also be used to analyze current placement recommendations for common scenarios. Use of the system will allow highway safety personnel to better understand the performance and applicability of various types of crash attenuators. Further, the research extends the concept of a decision hierarchy by: (1) using deterministic and heuristic importance functions to vary the weights to reflect changes in site conditions; and (2) using a possibilistic matching algorithm to include historical data that partially matches the user-input site characteristics in the performance evaluations.     

Alcohol expectancies regarding sex, aggression, and sexual vulnerability: Reliability and validity assessment.

This study was designed to validate the Alcohol Expectancies Regarding Sex, Aggression, and Sexual Vulnerability Questionnaire. This instrument includes alcohol expectancies in 4 domains (aggression, sexual affect, sexual drive, and vulnerability to sexual coercion) for 3 targets (self, women, and men). Confirmatory factor analyses with 715 undergraduates supported the hypothesized factor structure for the entire sample, as well as for gender and ethnic subgroups. Each of the subscales had high internal consistency reliability, moderate test-retest reliability, and good discriminant validity. Multivariate analyses of variance supported the hypothesis that participants' alcohol expectancies for other people conformed to gender role stereotypes. Participants saw themselves as being less influenced by alcohol than were others. Implications for sexual assault prevention programs are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Diversity-oriented synthesis of blue emissive nitrogen heterocycles and their conjugation with carbon nano-onions

The search for new fluorescent molecules for possible applications as functional p-electron systems and their conjugation with different nanomaterials is nowadays of paramount importance to broaden the availability of materials with different properties. Herein we present a diversity-oriented approach to heterocyclic luminophores based on a multicomponent Ugi reaction followed by a Pd-mediated cascade sequence. The new molecules are coupled to carbon nano-onions, and hybrid systems represent the first example of blue emitters conjugated with these carbon nanoparticles.     

Color improves object recognition in normal and low vision.

Does color improve object recognition? If so, is the improvement greater for images with low spatial resolution in which there is less shape information? Do people with low visual acuity benefit more from color? Three experiments measured reaction time (RT) and accuracy for naming food objects displayed in 4 types of images: gray scale or color, and high or low spatial resolution (produced by blur). Normally sighted Ss had faster RTs with color, but the improvement was not significantly greater for images with low spatial resolution. Low vision Ss were also faster with color, but the difference did not depend significantly on acuity. In 2 additional experiments, it was found that the faster RTs for color stimuli were related to objects' prototypicality but not to their color diagnosticity. It was concluded that color does improve object recognition, and the mechanism is probably sensory rather than cognitive in origin. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Male violence against women: Current research and future directions.

This Psychology in the Public Forum section, authored by the American Psychological Association's Committee on Women in Psychology's Task Force on Male Violence Against Women and by Senator Joseph Biden, examines the prevalence, impact, and public policy dimensions of physical assault, sexual assault, and sexual harassment of women. This introduction reviews common themes that emerge from the articles that follow. It concludes by emphasizing that the problem of violence against women cannot be fully understood, let alone solved, by focusing exclusively on individual psychology. Only by changing the social and cultural institutions that have given rise to the problem can a lasting solution be achieved. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Therapists' emotional reactions to substance abusers: A new questionnaire and initial findings.

Developed and tested the Ratings of Emotional Attitudes to Clients by Treaters (REACT) scale. The REACT was administered to 52 therapists and 140 cocaine-dependent outpatients, at sessions 2, 5, and 24 of psychotherapy. It was found to have high internal consistency at each time point, moderately high convergent validity with therapists' (but not patients') therapeutic alliance ratings, and a factor structure that appeared to meaningfully derive 4 factors: "therapist in conflict with self," "therapist focused on own needs," "positive connection," and "therapist in conflict with the patient." Therapists' emotional responses were found to become more negative over the course of treatment, and, when compared by theoretical orientation, were found more positive for 12-step drug counselors than for cognitive or supportive-expressive therapists. (PsycINFO Database Record (c) 2010 APA, all rights reserved)