Supportive friendships moderate the association between stressful life events and sexual risk taking among African American adolescents.

Objective: This study examined whether uncontrollable stressful life events were associated with sexual risk taking among adolescents across a 1-year period, and whether supportive friendships modified associations. Design: Participants were 159 sexually active African American adolescents (57% male; mean age [SD] = 17.0 [1.5] years at baseline). Participants were recruited for in-person interviews through random digit dialing in one inner-city neighborhood characterized by high rates of poverty and crime relative to the surrounding city. Main Outcome Measures: Dependent variables included substance use before sexual activity and inconsistent condom use. Results: Among adolescents who reported low levels of supportive friendships, uncontrollable stressors were associated with greater levels of sexual risk taking over time. In contrast, uncontrollable stressors were not associated with sexual risk taking among adolescents who reported high social support from friends; risk taking was typically moderate to high among these adolescents. Conclusion: Different processes may explain sexual risk taking among adolescents with varying levels of social support from friends. Adolescents with low support may be prone to engagement in health risk behavior as a stress response, while adolescents with high support may engage in risk behavior primarily due to peer socialization of risk. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lattice Boltzmann simulation of cerebral artery hemodynamics

A hemodynamics analysis approach that combines the level-set method for medical imaging processing and the Lattice Boltzmann method for flow simulation with patient-specific cerebral vasculature geometry is presented. The flow solver is validated by simulating a bent duct flow and is then applied to investigate blood flow in actual cerebral artery models. It is demonstrated that this approach is effective in studying complex hemodynamic flows.     

Application of an alternative contractor selection model

The results described confirm the thorough assessment implemented by the model and an output mechanism able to highlight key contractor characteristics. The exercise also supports the contention, that examination of contractors should aim to establish project performance potential and rely less on estimated project cost (tender sum).     

Wound healing and the immune response in swine treated with a hemostatic bandage composed of salmon thrombin and fibrinogen

We investigated the inflammatory response in pigs exposed to salmon fibrinogen/thrombin dressings. Animals were exposed to the material in 3 ways: (a) thrombin and fibrinogen were injected intravenously, (b) dual full-thickness skin lesions were surgically created on the dorsal aspect of the swine and treated with the fibrinogen/thrombin bandage and a commercial bandage or (c) a fibrinogen/thrombin bandage was inserted through an abdominal incision into the peritoneal cavity. Blood was collected twice weekly and animals were sacrificed at 7, 10 or 28 days. Animals in the 28-day dermal lesion group were given an injection of salmon fibrinogen/thrombin at the 10 day point to simulate a second bandage application. The immune response manifested itself as induction of germinal centers in mesenteric lymph nodes and in the white pulp of the spleen. Examination of the histology of the skin and organs showed a cellular inflammatory response with granulation tissue and signs of edema that resolved by the 28-day stage. Antibodies reactive to salmon and human thrombin and fibrinogen were detected, but fibrinogen levels and coagulation processes were not affected. In conclusion, animals treated with salmon fibrinogen/thrombin bandages demonstrated a smooth recovery course in terms of both tissue healing and the immune response without adverse effects from the exposure to the fish proteins.     

Anti-inflammatory activity of Pseudopterosins by laser doppler blood flow evaluation

IFSCC Magazines , 12 (2009) (1) 25–30
Approximately 40% of the population (all skin categories and phototypes) complain of sensitive skin. Sensitive skin is healthy but overresponsive, meaning it reacts faster and more intensely to several parameters including environmental factors such as temperature changes and the sun, use of cosmetic products, and certain medicines. It experiences discomfort, tingling, burning and intolerance to certain types of products, a condition referred to as neurosensitivity characterized by a lower threshold of tolerance. Currently, all of the causes are not known but an increase in the permeability of the stratum corneum and an exaggeration of the nerve response are considered to be involved in the phenomenon of sensitive skin. Lifestyle factors including tobacco, alcohol, stress, fatigue and emotions also have an effect. A new synthetic tetrapeptide, N -acetyl- L -tyrosyl- L -prolyl- L -phenylalanyl- L -phenylalaninamide (Ac-YPFF-NH2), mimicking a natural opioid peptide was developed with the aim to decrease skin nerve ending stimulation. This tetrapeptide was demonstrated in vitro to reduce cutaneous overreactivity by decreasing release of calcitonin gene-related peptide from sensory neurons via an agonist effect on the μ opioid receptors and in vivo to improve the comfort of sensitive skin by decreasing unpleasant sensations and pain induced by heat and capsaicin. This tetrapeptide targeting an exaggerated nerve response helps to relieve sensitive skin by normalizing the tolerance threshold for environmental factors or certain topically applied uncomfortable products or skincare treatments.
Keywords:  Calcitonin gene-related peptide, μ opioid receptor, nerve endings, peptide, sensitive skin     

THE RELATIONSHIP OF CONTROL AND LEARNING TO PROJECT PERFORMANCE

ABSTRACT

Management controls can be divided into two types that can have opposite effects on organizational learning: behavioral controls, which promote efficiency but also stifle much of the learning opportunity, and outcome controls, which foster interaction among stakeholders can add to the learning environment. This article reports on a study that confirms these observations and explores the nature of their direct and indirect influences on project performance. Data from a sample of software development professionals confirms that behavioral controls and learning directly influence project performance, while outcome controls contribute only indirectly through their impact on learning.     

Assessing the Floristic Diversity of Hedge Networks: A landscape perspective

The type of land cover adjacent to hedges has been shown to influence the species composition of the ground flora. An assessment of the contribution of hedge networks to the biodiversity of landscapes therefore requires information on the relative lengths of hedge associated with different land covers. In the River Tyne catchment, Northern England, the association between hedges and land cover types differed between four landscapes. Overall, the greatest length of hedge was adjacent to arable crops, improved grasslands and roads. Hedges next to improved grassland and roads were the most species-rich, while those adjacent to arable crops were the least species-rich. Species which were common adjacent to arable crops were also common adjacent to other land covers. Hedges adjacent to improved grassland, roads and semi-natural broadleaved woodland supported species which were not common elsewhere in the hedge network. It was also found that hedges with different land cover on each side supported different floras on each side. When planning landscape-scale surveys of hedge biodiversity, it is important to survey both sides of hedges, and sampling should be stratified to include hedges adjacent to the different types of land cover present.     

Estimating life cycle plant maintenance costs

The financial success or otherwise of a maintenance strategy can be determined realistically only when actual costs are compared with target ‘predicted’ values. This is because, in the absence of accurate cost control mechanisms, maintenance expenditure can exceed capital cost. In order to address this problem, a methodology is presented for predicting life cycle maintenance expenditure over the useful life of tracked hydraulic excavators. First, time series analysis (using a moving centred average) illustrates that the trend in maintenance cost expenditure is difficult to isolate due to large perturbations in periodic unscheduled maintenance. Such expenditure accounts for 92% of total maintenance cost. Second, cumulative costs of maintenance are modelled using a cubic equation, with time (in hours) as the predictor (x_n) variable. Model performance is robust with a coefficient of determination (R²) of 0.99 and a mean percentage error (MPE) of minus 3.94. The paper concludes with direction for future research in this field, particularly with respect to expanding the model's application to machines of various weights, manufacturers and machines operating in other industries, and determination of criteria with which to predict when a plant item will reach the end of its useful life.     

Application of Active Contours on Metallurgical Microstructures

Employing computer algorithms for finding and outlining the boundaries between phases or grain boundaries (referred to as edge detection) is a widely used technique employed as an intermediate step in microstructure analysis. Having an outlined region of interest enables the user to extract data about the region or use it in the reconstruction of three-dimensional models. Because traditional edge detection relies on a user-selected threshold value, the results often are subjective. Furthermore, traditional edge detection frequently results in outlines that are incomplete, requiring additional processing steps, such as edge linking and spur removal. Active contouring is an edge-detection-based technique that typically yields results superior to that of a traditional edge detector. High noise tolerance and built-in flexibilities of active contours make the technique desirable to use across a broad range of applications. Although initially used for meteorological applications, several uses of active contours are presented for metallurgical microstructural data obtained using optical and electron microscopies to demonstrate robustness and the range of applications that can employ active contours.