Cardiovascular responses to occupational stress in male medical students: A paradigm for ambulatory monitoring studies.

Examined hemodynamic responses to systematic variations in occupational stress using ambulatory blood pressure monitors. Heart rate, systolic blood pressure, diastolic blood pressure, rate–pressure product, and mood states were measured before, during, and after low-stress (lecture) and high-stress (examination) work in 44 healthy White male medical students. The lecture day was characterized by stable patterns of cardiovascular activity across all 3 periods. Hemodynamic activity and reports of activation and distress were greater on the examination day than on the lecture day. Cardiovascular activity during the pre-examination period was as high as that seen during the examination period itself, indicating an anticipatory stress effect. Pressor activity decreased after the examination, although some residual chronotropic activity was seen. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of Specimen Geometry in the Effect of Fiber Orientation on the Thermal Conductivity of a Uniaxial Carbon-Fiber-Reinforced Aluminoborosilicate Glass-Matrix Composite

A study concerning the effect of fiber orientation on the thermal conductivity of a uniaxial carbon-fiber-reinforced borosilicate glass was conducted. For thin specimens, and thick specimens with specimen sides cut parallel to the fiber direction, the dependence of thermal conductivity on fiber orientation showed excellent agreement with theoretical behavior predicted for a composite infinite in extent. In contrast, the thermal conductivity data for rectangular thick specimens fell well below the data for the thin and angled specimens. For fiber orientation of 45° and higher, at which the heat was directed toward the side of the specimen rather than across, the thermal conductivity values showed excellent agreement with theoretical behavior predicted for a finite composite strip with insulated sides.     

Improved quality of continuous flow manufacturing through the combination of statistical process control and conventional computer process control

This paper represents a portion of the evaluation of the use of Statistical Process Control within the realm of Conventional Computer Process Control. Various control charts commonly utilized in continuous processes are evaluated when subjected to process disturbances typical of continuous processes. The control charts considered are the Moving Average and Moving Range Chart combination, the Individual and Moving Range Chart combination, and the Exponentially Weighted moving Average Chart. The types of process disturbances considered are unit step and linear trend disturbances to the process average. The evaluation is based on the determination of the Average Run Lengths (ARLs) resulting from computer simulations.     

On the Mechanism of Palladium(0)-Catalyzed Reactions of Allylic Substrates with Nucleophiles. Origin of the Loss of Stereospecificity

The mechanism of the loss of stereospecificity in palladium-catalyzed nucleophilic substitution of allylic substrates has been investigated. Eight substrates (cis and trans isomers of 1a-d) and two nucleophiles (Et₂NH and NaCH(SO₂Ph)₂) were studied. In the animation reactions two pathways are responsible for the formation of anomalous inversion product, viz., isomerization of the starting material (path B, Scheme 2) and isomerization of the π-allyl intermediate via displacement of palladium by Pd(0) (path C, Scheme 2), the latter of which predominates. In the alkylation the results indicate that loss of stereospecificity is caused only by path C. The use of a more reactive substrate increased the stereospecificity of the reaction and suppressed the isomerization pathway. An analysis of the kinetics is consistent with the hypothesis that path C is the major pathway for the stereochemical loss.     

Citizen Preferences and Paying for Police

Abstract: Researchers frequently approach questions dealing with local fiscal decision‐making using economic models. These models typically base the demand for public services on a set of socioeconomic characteristics that serve as rough proxies for voter preferences. Our study focuses more directly on preference formation and explores the nature of the relationship between citizens’ attitudes about police services and their willingness to pay for them. We pay particular attention to the role of demographic traits, television media, and direct contact with service providers. We present data from a survey of Connecticut adults and use these data to test direct and indirect effects models with regression analysis. We find evidence that attitudes about police predict willingness to pay for police services, holding the demographic attributes of respondents constant. We also find that the effects of some demographic traits on demand for services are mediated by preferences, as are some types of experience and media exposure.     

Temperamental resistance to control increases the association between sleep problems and externalizing behavior development.

This study examined the moderating effects of temperamental resistance to control on the link between development of sleep problems and development of externalizing behaviors over a 5-year period. Resistance to control was assessed with mothers' retrospective reports of temperament in infancy, provided when children were 5 years of age. Sleep problems were assessed with mother reports on an annual basis from age 5 to age 9. Externalizing behaviors were assessed with teacher reports on an annual basis from age 5 to age 9. A cross-domain latent growth curve model indicated that sleep problem trajectories were positively associated with externalizing behavior trajectories only for children high in resistance to control. In addition, resistance to control was positively associated with initial (age 5) sleep problems and initial (age 5) externalizing behaviors. The authors speculate that the development of sleep problems promotes the development of behavior problems for resistant children, whose self-regulatory abilities are especially tenuous. Implications for prevention and treatment of conduct problems are considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Durability of polymeric glazing materials for solar applications

The economic viability of solar collector systems for domestic hot water (DHW) generation is strongly linked to the cost of such systems. Installation and hardware costs must be reduced by 50% to allow significant market penetration. An attractive approach to cost reduction is to replace glass and metal parts with less expensive, lighter weight polymeric components. Weight reduction decreases the cost of shipping, handling, and installation. The use of polymeric materials also allows the benefits and cost savings associated with well established manufacturing processes, along with savings associated with improved fastening, reduced part count, and overall assembly refinements. A key challenge is to maintain adequate system performance and assure requisite durability for extended lifetimes. Results of preliminary and ongoing screening tests for a large number of candidate polymeric glazing materials are presented. Based on these results, two specific glazings with moderate and poor weathering stability are selected to demonstrate how a service lifetime methodology can be applied to accurately predict the optical performance of these materials during in-service use. A summary is given for data obtained by outdoor exposure and indoor testing of polyvinyl chloride (PVC) and high temperature modified polycarbonate copolymer (coPC) materials, and an initial risk analysis is given for the two materials. Screening tests and analyses for service lifetime prediction are discussed. A methodology that provides a way to derive correlations between degradation experienced by materials exposed to controlled accelerated laboratory exposure conditions and materials exposed to in-service conditions is given, and a validation is presented for the methodology based upon durability test results for PVC and coPC.     

Dynamic Effects in Hopkinson Bar Four-Point Bend Fracture

Hopkinson bar techniques have played an important role in the study of high-rate deformation and fracture behavior of materials. In the current work, a split Hopkinson pressure bar was developed for dynamic four-point bend fracture testing, referred to as a “two-bar (incident and transmitted bars)/four-point” (2-bar/4-pt) bend test. To further understand some fundamental issues regarding stress wave propagation in this 2-bar/4-pt bend testing system, dynamic fracture tests were performed in pulse-shaped and unshaped pulse testing conditions. The effect of the pulse shaper on the incident pulse characteristics (rise time and duration), specimen’s dynamic response (load and loading point displacement), crack initiation time and stress-state equilibrium were investigated experimentally in the current work. The present results show that stress state equilibrium can be achieved prior to fracture initiation in notched and precracked specimens. In the pulse-shaped bending test, the specimen is more likely to attain stress-state equilibrium than in an unshaped incident pulse test. The crack initiation time was extended and the time required for attaining stress equilibrium was reduced by pulse shaping due to the tailored incident pulse having a longer rise time, which ensures that stress equilibrium is achieved prior to crack initiation. This article is based on a presentation made in the symposium entitled “Dynamic Behavior of Materials,” which occurred during the TMS Annual Meeting and Exhibition, February 25–March 1, 2007 in Orlando, Florida, under the auspices of The Minerals, Metals and Materials Society, TMS Structural Materials Division, and TMS/ASM Mechanical Behavior of Materials Committee.     

The residential therapeutic caring community.

The residential therapeutic caring community (RTCC) for adolescents combines psychotherapeutic principles of the professional model and self-help concept of the therapeutic community by using the collective resources of members to mobilize peer pressure. The RTCC is a safe, structured, supportive treatment environment that employs a confrontation, teaching, interpretative, and reasoning approach and uses the psychotherapeutic principles of reality therapy and existential thought. In the RTCC, the staff serve as mentors and role models, and they demonstrate their concern by maintaining high expectations for immediate improved behavior. The personal qualities necessary for a psychotherapist working in an RTCC are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)