Relationships between orthopedic disability and perceived social support: Four theoretical hypotheses.

Tested the way in which an orthopedic disability affects reported social support (SSU), using path analysis with 100 Ss with mild orthopedic disabilities. Hypotheses were offered concerning the effect of vulnerability, uncertainty, personality, and social resources on perceived SSU. Ss were given measures of social support, severity of disability, conspicuousness, sense of impediment, anxiety, and social status. An older S whose disability was not conspicuous and who suffered high trait anxiety, experienced least support; a younger, nonanxious S, whose disability was clearly visible, experienced most support. Ss' personality was more important in terms of perceived SSU than was the actual disability, and the uncertainty of an encounter between an able-bodied and disabled person contributed to the perception of less SSU by the S. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Glomerular endothelial cells synthesize collagens but little gelatinase A and B

Mesangial sclerosis is a major feature of progressive renal disease. The mesangium contains mesangial cells and is bounded by the peripheral glomerular basement membrane and endothelial cells. Mesangial cells synthesize and degrade extracellular matrix. Whereas both mesangial and endothelial cells synthesize extracellular matrix components, the degradative pathway, well studied in the former, has not been investigated in endothelial cells. This study examines lines of all three glomerular cell types derived from female B6SJLF1/J mice, as well as mRNA levels for collagens alpha1(I), alpha1(IV), alpha3 (IV), alpha5 (IV), and alpha1 (VI), laminin, tenascin, matrix metalloproteinase-2 (MMP-2), and MMP-9. Type I and IV collagen synthesis was confirmed by enzyme-linked immunosorbent assay. MMP-2 and MMP-9 enzyme activity was measured by zymography. It was found that glomerular endothelial cells are a significant source of collagens, laminin, and tenascin. However, they express only low levels of MMP-2 and no detectable MMP-9. Stimulation with exogenous transforming growth factor-beta1 leads to a significant increase in collagen I, tissue inhibitors of metalloproteinase-1, and MMP-9 in conditioned media. These data suggest that glomerular endothelial cells may play an active role in extracellular matrix remodeling in glomerular disease.     

Making research apply: High stakes public policy in a regulatory environment.

The experiences of 3 social psychologists asked to evaluate (and improve) a series of large-scale programs designed to change energy-related attitudes and behavior are described. The research generated significant change but also substantial conflict involving both the utility companies being evaluated and the state agency that commissioned the evaluation. This experience is reviewed with an eye to maximizing the usefulness of future efforts to apply social psychology in complex and potentially conflicted public policy arenas. The difference between influence and power models of applied research is discussed, and possible remedies are examined for social psychologists undertaking future research similar in scale, policy consequences, or potential controversy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of stoichiometry on the fracture toughness of a liquid crystalline epoxy

The fracture toughness of a liquid crystalline epoxy was compared with that of a standard bisphenol‐A based epoxy to understand how both the liquid crystalline structure and the crosslink density affect fracture toughness. For the liquid crystalline epoxy, the liquid crystalline domain size decreased with increasing temperature of cure and away from the stoichiometric formulation. Quantitative fractography showed that there is a competition between the liquid crystalline domain structure and the stoichiometry in determining the fracture toughness. At some cure conditions the effect of the domains is dominant. When the cure conditions are adjusted to reduce the domain size, the domains become too small to affect the fracture toughness, and thus the effect of the stoichiometry is dominant. The result is that the formation of liquid crystalline structure only increases the fracture toughness relative to that of a traditional epoxy at and near the stoichiometric formulation.     

Exercise stimulates the mitogen-activated protein kinase pathway in human skeletal muscle

Physical exercise can cause marked alterations in the structure and function of human skeletal muscle. However, little is known about the specific signaling molecules and pathways that enable exercise to modulate cellular processes in skeletal muscle. The mitogen-activated protein kinase (MAPK) cascade is a major signaling system by which cells transduce extracellular signals into intracellular responses. We tested the hypothesis that a single bout of exercise activates the MAPK signaling pathway. Needle biopsies of vastus lateralis muscle were taken from nine subjects at rest and after 60 min of cycle ergometer exercise. In all subjects, exercise increased MAPK phosphorylation, and the activity of its downstream substrate, the p90 ribosomal S6 kinase 2. Furthermore, exercise increased the activities of the upstream regulators of MAPK, MAP kinase kinase, and Raf-1. When two additional subjects were studied using a one-legged exercise protocol, MAPK phosphorylation and p90 ribosomal S6 kinase 2, MAP kinase kinase 1, and Raf-1 activities were increased only in the exercising leg. These studies demonstrate that exercise activates the MAPK cascade in human skeletal muscle and that this stimulation is primarily a local, tissue-specific phenomenon, rather than a systemic response to exercise. These findings suggest that the MAPK pathway may modulate cellular processes that occur in skeletal muscle in response to exercise.     

Energy conservation behavior: The difficult path from information to action.

Presents a social-psychological model of energy-use behavior that draws on behavioral and social research to explain influence processes and behavioral change related to energy conservation behavior. The model consists of 2 interacting sets of factors: psychological factors that refer to how information is processed by individual decision makers and positional factors that relate to characteristics of the decision makers' situations that support or constrain action. Suggestions for maximizing the effectiveness of informational appeals to conserve energy by convincing the consumer that a pay-off will result from the use of energy conserving devices are discussed. It is suggested that the adoption of a conservatory attitude is influenced by the vividness of the argument to conserve energy, the credibility of the source, the understanding and retention of the message, and the degree to which an individual is able and willing to install conservation devices in his/her home. Alternatives to informational appeals through mass media to encourage energy conservation are proposed. (47 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Human climbing with efficiently scaled gecko-inspired dry adhesives

Since the discovery of the mechanism of adhesion in geckos, many synthetic dry adhesives have been developed with desirable gecko-like properties such as reusability, directionality, self-cleaning ability, rough surface adhesion and high adhesive stress. However, fully exploiting these adhesives in practical applications at different length scales requires efficient scaling (i.e. with little loss in adhesion as area grows). Just as natural gecko adhesives have been used as a benchmark for synthetic materials, so can gecko adhesion systems provide a baseline for scaling efficiency. In the tokay gecko (Gekko gecko), a scaling power law has been reported relating the maximum shear stress σ_max to the area A: σ_max ∝ A^−1/4. We present a mechanical concept which improves upon the gecko''s non-uniform load-sharing and results in a nearly even load distribution over multiple patches of gecko-inspired adhesive. We created a synthetic adhesion system incorporating this concept which shows efficient scaling across four orders of magnitude of area, yielding an improved scaling power law: σ_max ∝ A^−1/50. Furthermore, we found that the synthetic adhesion system does not fail catastrophically when a simulated failure is induced on a portion of the adhesive. In a practical demonstration, the synthetic adhesion system enabled a 70 kg human to climb vertical glass with 140 cm² of adhesive per hand.     

Pressure-Based Liquid Feed System for Suspension Plasma Spray Coatings

Thermal spraying with liquid-based feedstocks demonstrated a potential to produce coatings with new and enhanced characteristics. A liquid delivery system prototype was developed and tested in this study. The feeder is based on the 5MPE platform and uses a pressure setup to optimally inject and atomize liquid feedstock into a plasma plume. A novel self-cleaning apparatus is incorporated into the system to greatly reduce problems associated with clogging and agglomeration of liquid suspensions. This approach also allows the liquid feedstock line to the gun to remain charged for quick on-off operation. Experiments on aqueous and ethanol-based suspensions of titania, alumina, and YSZ were performed through this liquid delivery system using a 9MB plasma gun. Coatings with ultrafine splat microstructures were obtained by plasma spraying of those suspensions. Phase composition and microstructure of the as-sprayed coatings were investigated.