Why do dominant personalities attain influence in face-to-face groups? The competence-signaling effects of trait dominance.

Individuals high in the personality trait dominance consistently attain high levels of influence in groups. Why they do is unclear, however, because most group theories assert that people cannot attain influence simply by behaving assertively and forcefully; rather, they need to possess superior task abilities and leadership skills. In the present research, the authors proposed that individuals high in trait dominance attain influence because they behave in ways that make them appear competent--even when they actually lack competence. Two studies examined task groups using a social relations analysis of peer perceptions (D. A. Kenny & L. LaVoie, 1984). The authors found that individuals higher in trait dominance were rated as more competent by fellow group members, outside peer observers, and research staff members, even after controlling for individuals' actual abilities. Furthermore, frequency counts of discrete behaviors showed that dominance predicts the enactment of competence-signaling behaviors, which in turn predicts peer ratings of competence. These findings extend researchers' understanding of trait dominance, hierarchies in groups, and perceptions of competence and abilities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Advancing Equity in Clinical Preventive Services: The Role of Health Communication

In 2002, the Institute of Medicine released its landmark report “Unequal Treatment: Confronting Racial and Ethnic Disparities in Health Care.” This report led to increased efforts in identifying, assessing, and documenting racial and ethnic disparities in health care, as well as developing, testing, and implementing interventions in an attempt to reduce health disparities throughout the United States. This article reviews the rise of health disparities research in the United States and reports on selected studies and interventions developed by researchers at the Northwestern University Feinberg School of Medicine. These interventions have used communication and behavioral science theories and frameworks in their development and dissemination, particularly in the realm of clinical preventive medicine.     

Composite Semiconductor Material of Carbon Nanotubes and Poly[5,5′-bis(3-dodecyl-2-thienyl)-2,2′-bithiophene] for High-Performance Organic Thin-Film Transistors

A nonpercolating network of non-covalently functionalized single-walled carbon nanotubes was embedded within air-stable poly[5,5′-bis(3-dodecyl-2-thienyl)-2,2′-bithiophene] (PQT-12) thin films for the purpose of enhancing the field-effect mobility in thin-film transistors. The host polymer was used to stabilize the nanotubes in suspension through π-orbital overlap caused by simple application of ultrasonication. The stable nanotube suspension was cast into two different device architectures, both of which exhibited excellent on/off ratios ranging from 10⁵ to 10⁶ and dramatically improved mobilities compared with pristine PQT-12 semiconductor. A single-layer film with nanotubes embedded throughout was easy to fabricate and had mobility up to 0.34 cm²/Vs, an enhancement of over 3× compared with PQT-12. Placing the nanotubes closer to the dielectric surface in a dual-layer approach resulted in a mobility improvement of up to six times (0.58 cm²/Vs). The effects of the nanotube content on the polymer interaction within the suspension, film morphology, and electrical properties were investigated as well.     

Evaluation of the historical records of lead pollution in the annual growth rings and bark pockets of a 250-year-old Quercus crispula in Nikko,Japan

The annual growth rings and bark pockets of a 250-year-old Japanese oak (Quercus crispula), collected from the Nikko National Park, Japan in 2000 AD, were analysed by ICP mass spectrometry. The annual rings, sampled in 5-year increments, recorded Pb concentrations from 0.01 to 0.1 mg kg(-1) and there was no significant change in concentration with time. In contrast, bark pocket samples dating from 1875 to the present showed a progressive increase in Pb concentration with time, from approximately 0.1 to 10 mg kg(-1). Shoots of epiphytic moss growing on the tree trunk contained 17 mg kg(-1) Pb. The bark pockets recorded historical increases in airborne Pb pollution accompanying the industrialisation of Japan, which was initiated by the opening of Japan's borders from 1854. This increase was not reflected by the annual rings. The 206Pb/207Pb isotope ratio of the bark pockets decreased from approximately 1.18 to 1.16 from 1964 to the present, indicating changes in the sources of Pb pollution. The 206Pb/207Pb isotope ratio of the moss shoots was similar to the current bark (1.16). The data showed bark pockets to be more effective than annual rings for recording historical change in airborne lead pollution.     

Enhancing the effectiveness of tobacco package warning labels: a social psychological perspective

OBJECTIVE: To outline social psychological principles that could influence the psychosocial and behavioural effects of tobacco warning labels, and to inform the development of more effective tobacco warning labels. DATA SOURCES: PsycInfo and Medline literature searches and expert guided selection of principles and theories in social psychology and of tobacco warning labels, including articles, books, and reports. CONCLUSIONS: Tobacco warning labels represent a potentially effective method of influencing attitudes and behaviours. This review describes social psychological principles that could be used to guide the creation of more effective warning labels. The potential value of incorporating warning labels into a broader public health education campaign is discussed, and directions for future research are suggested.     

Optical particle sizing in backscatter

Several possibilities for the use of elastic light scattering in the backscatter range (scattering angle theta(s) > 140 deg) for determination of size, velocity, and refractive index of spherical particles are investigated. First the phase Doppler technique is considered. Numerical simulations of light scattering with the Lorenz-Mie theory are used to show that the phase Doppler technique is unsuitable for such backscatter configurations, except for special measurement conditions. The time-shift (or pulse-displacement) technique is then considered by use of the Fourier-Lorenz-Mie theory. Simulations show that up to four fractional signals can be obtained by use of the technique in backscatter, corresponding to the scattering order or modes: surface wave (long path), reflection, second-order refraction (inner path), and a mixture of second-order refraction (outer path) and surface wave (short path). Signal characteristics as a function of particle size, refractive index, and particle ellipticity are studied. Suggestions for a practical measurement instrument are put forward.     

A neuromorphic depth-from-motion vision model with STDP adaptation

We propose a simplified depth-from-motion vision model based on leaky integrate-and-fire (LIF) neurons for edge detection and two-dimensional depth recovery. In the model, every LIF neuron is able to detect the irradiance edges passing through its receptive field in an optical flow field, and respond to the detection by firing a spike when the neuron's firing criterion is satisfied. If a neuron fires a spike, the time-of-travel of the spike-associated edge is transferred as the prediction information to the next synapse-linked neuron to determine its state. Correlations between input spikes and their timing thus encode depth in the visual field. The adaptation of synapses mediated by spike-timing-dependent plasticity is used to improve the algorithm's robustness against inaccuracy caused by spurious edge propagation. The algorithm is characterized on both artificial and real image sequences. The implementation of the algorithm in analog very large scale integrated (aVLSI) circuitry is also discussed.     

Videoendoscopic diagnosis of esophageal motility disorders

PURPOSE: Looking for a valid, reliable, and feasible method to collect data on the performances of practicing family physicians, the authors compare the measurement characteristics of a multiple-station examination (MSE) using standardized patients with those of a video assessment of regular consultations in daily practice (practice video assessment, PVA). METHOD: In a cross-sectional study, consultations of 90 family physicians were videotaped both in an MSE and in their daily practices. Peer-observers used a validated instrument (MAAS-Global) to assess the physicians' communication with patients and their medical performances. The physicians were randomly divided into two groups, comparable for demographic characteristics, and half underwent the assessments in reverse order to test for time-order effects. Content validity, criterion validity, reliability, and feasibility of the two methods were compared. RESULTS: Content validity of the PVA was superior to that of the MSE, since the domain of general family practice care was better covered. Observed participants judged the videotaped practice consultations to be "natural," whereas hardly any family physician, after reviewing the videotaped consultations of the MSE, recognized his or her usual working style. Specific criteria made it possible to standardize real practice. Concerning criterion validity, only the medical-performance components of the two methods correlated. No correlation was found for the communication components. Real-practice performance proved to be less influenced by observation than was performance during the MSE. The reliabilities of the two methods, expected to be better in the controlled MSE, were comparable. The administration of the PVA was more flexible, less costly, and better accepted by the family physicians than was that of the MSE. CONCLUSION: Assessment for quality improvement of family physicians' practices by video observation in daily practice is superior to video assessment in a simulated setting using standardized patients.     

Light backscattering polarization patterns from turbid media: theory and experiment

We present both experimental measurements and Monte-Carlo-based simulations of the diffusely backscattered intensity patterns that arise from illuminating a turbid medium with a polarized laser beam. It is rigorously shown that, because of axial symmetry of the system, only seven elements of the effective backscattering Mueller matrix are independent. A new numerical method that allows simultaneous calculation of all 16 elements of the two-dimensional Mueller matrix is used. To validate our method we compared calculations to measurements from a turbid medium that consisted of polystyrene spheres of different sizes and concentrations in deionized water. The experimental and numerical results are in excellent agreement.     

LDL particle size in subjects with previously unsuspected coronary heart disease: relationship with other cardiovascular risk markers

PURPOSE: We report a retrospective series of 850 patients treated by external irradiation for carcinoma of the eyelid at Institut Curie and we compare our results with other techniques: brachytherapy and surgery. METHODS AND MATERIALS: Eight hundred fifty patients were treated by external radiotherapy for carcinoma of the eyelid. None of these patients have been previously treated. All the patients were classified according to the TNM classification of (UICC). We distinguished five histological types and five clinical groups according to the site of the skin tumor. Three modalities of external radiotherapy were used: contact therapy, conventional radiotherapy, and electrontherapy. We reviewed the clinical files of the 850 patients who went regularly at follow-up visits. RESULTS: We report the 5-year survival results--alive with no evidence of disease: 72%; alive with progression: 2%; died from tumor progression: 0.5%; died from intercurrent disease: 19.5%; and lost to follow-up: 5%. The 5-year local control rate was 97.5%. We observed 45 failures--lymph node, metastatic, and local--and emphasize this last group by presenting the results of treatment of these local failures. We studied the complications of treatment: 2.3% of corneal complications, 2% of cataracts, and 1.4% of serious ocular complications. CONCLUSIONS: Our results concerning local failures and loss of the eye are comparable to those reported for other techniques involving brachytherapy or surgery. Overall, external radiotherapy is a safe and effective treatment, as it ensures a high local control rate and provides perfectly satisfactory functional and esthetic results. It seemed particularly useful to report this series in that few publications are available on this subject that, nevertheless, constitutes a topical issue.