The sympathetic nervous system''s role in regulating blood pressurevariability

This article focuses on how sympathetic nerve activity (SNA) contributes to the variability seen in blood pressure. Specifically, it examines the following questions: why do oscillations occur at certain frequencies, why do only certain frequencies of oscillations in SNA induce oscillations in the vasculature, and what may be the functional purpose of these oscillations     

Field-induced electron emission from electrically nanostructured heterogeneous (ENH) materials.

This paper discusses the origins of field-induced electron emission from thin films of electrically nanostructured heterogeneous (ENH) materials. Such materials exhibit low macroscopic field (LMF) electron emission: as thin films on a conducting substrate, they emit electrons into vacuum when LMFs, typically about 1-10 V/microm, are applied. An ENH material comprises: a dielectric matrix, which may contain nanoscale inclusions of higher electrical conductivity; conducting channels that open in the dielectric between the inclusions (if present) and between them and the substrate; and an electron emitting channel that opens into vacuum. Electrically nanostructured heterogeneous materials can have a variety of different detailed structures and theories, but all can exhibit LMF emission under suitable circumstances. This paper provides an updated summary of an integrating overview recently presented to explain LMF emission. A central feature is that electrical nanostructure within the film can create internal field enhancement, thereby producing a high local field at the vacuum interface: this enables thermalised electrons to escape rapidly into vacuum by tunnelling. The question of what aspect of the system controls the emission current is a separate issue. Various features and implications of the theory are set out.     

Remote,condition-based maintenance for web-enabled robotic system

The current trends in industry include an integration of information and knowledge-base network with a manufacturing system, which coined a new term, e-manufacturing. From the perspective of e-manufacturing any production equipment and its control functions do not exist alone, instead becoming a part of the holistic operation system with distant monitoring, remote quality control, and fault diagnostic capabilities. The key to this new paradigm is the accessibility to a remotely located system and having the means of responding to a changing environment, which is better suited for today's rapidly changing environment. Within the framework of the web-enabled robotic system, this paper focuses on the remote maintenance schemes with an emphasis on condition-based maintenance strategies. Real-time monitoring of robot harmonic drive systems and operational status have been attained over the Web. A mathematical modeling of system availability has been derived in order to account for other failures that might occur in the subsystems of the robot. Compared to the schedule-based maintenance strategies, the proposed approach shows great potential for improving overall production efficiency, while reducing the cost of maintenance.     

Prediction of plasticizer solvency using hansen solubility parameters

The solvating strength of a plasticizer for poly(vinyl chloride) resin is a measure of the interactive forces between these two materials. Hansen's three-dimensional solubility parameters provide a quantitative measure of these interactive forces. By using CO-ACT^SM service, a computer program designed for solvent systems with various resins, plasticizers were found to lie near the edge of the solvency “sphere” of PVC. The relative positions of various plasticizer structures are in the expected order, while known solvents show strong association and lubricating additives fall outside the solvency sphere of PVC.     

Risk aversion in rats (Rattus norvegicus) under varying levels of resource availability.

Five male Wistar rats chose between a certain prospect and an uncertain prospect having equal expected value under varying levels of resource (water) availability. In contrast to results found with granivorous birds and common shrews (Sorex araneus), the rats did not switch from risk aversion (choosing the certain prospect) to risk preference (choosing the uncertain prospect) as resource availability varied from surplus to deficit, even though deficits were maintained for extended periods of time. Rather, Ss displayed an approximately constant level of risk aversion throughout. Explanations for these differences are offered in terms of procedural differences between this and earlier studies and in terms of differential behavioral patterns of relatively large organisms with large internal resource stores relative to their daily resource requirements. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Taxometrics of Marriage: Is Marital Discord Categorical?

This study used taxometric methods to investigate the latent structure of the construct of marital adjustment as indexed by the Marital Adjustment Test (MAT; H. J. Locke & K. M. Wallace, 1959). That is, the authors examined whether marital adjustment is best thought of as a "dimension" of adjustment only or whether there also are categorical differences between "discordant" and "nondiscordant" couples. Analyses of data provided by 447 couples married for approximately 2 years provided converging evidence for a latent category of marital discord, suggesting that marital discord can be viewed as a qualitatively distinct state experienced by approximately 20% of the couples in the current sample. Implications for marital assessment are outlined. (PsycINFO Database Record (c) 2010 APA, all rights reserved)