Contractile Filament Stress: Comparison of Different Disease States in Man

Author Institution: Department of Engineering and Department of Physiology, Wright State UniversityCardiac catheterization data on 39 patients was classified in 5 cardiovascular groups: normal, compensated volume overload, decompensated volume overload, compensated pressure overload, and congestive cardiomyopathy. Both the Lagrangian stress and contractile filament stress for the circumferential axis and the longitudinal axis were computed over a complete cardiac cycle. Contractile filament stress was 24% higher than Lagrangian stress in the circumferential direction, and 43% higher than Lagrangian stress in the longitudinal direction. The percent difference in stress between the contractile filament stress and Lagrangian stress was greatest for patients with pressure overload, and least for patients with compensated volume overload. No significant difference in calculated wall stress was noted between the normal group and the 4 pathological groups. Circumferential velocity of the contractile element occurring at peak stress was plotted as a function of peak contractile filament stress and patients with compensated pressure overload exhibited high values of both velocity and peak stress. Patients with congestive cardiomyopathy showed low values of both velocity and peak stress. Circumferential velocity of the contractile element occurring throughout the cardiac cycle was plotted as a function of both the instantaneous Lagrangian stress and the instantaneous contractile filament stress, resulting in 2 stress-velocity curves for each patient. The value of the maximum velocity extrapolated from either stress-velocity curve was approximately the same, but the maximum stress extrapolated from the contractile filament stress-velocity curve was significantly higher than the maximum stress extrapolated from the Lagrangian stressvelocity curve. The product of peak contractile filament stress in the circumferential direction times heart rate was a clinically useful index of myocardial oxygen consumption, and predicted a lower rate of oxygen consumption than did the product of peak developed stress times heart rate

Active Material Properties of the Myocardium: Correlation With Left Ventricular Function in Man

Author Institution: Department of Engineering and Physiology, Wright State UniversityThe effects of anisotrophy and nonhomogeneity of the ventricular myocardium as represented by a linear increase in the midwall effective modulus of elasticity were investigated in the present study, specifically as they effect the circumferential stress distribution. Various studies are presented suggesting a linear increase in the effective modulus of elasticity from endocardium to epicardium. In our study, this increase in the effective modulus was constrained by the approximation that stress per unit sarcomere length is constant. We evaluated 12 functionally normal cases and 9 functionally abnormal cases. The stress distribution for the 9 functionally abnormal cases was calculated, first with the normal and secondly with the abnormal variation in the modulus of elasticity. Assuming the myocardium has constant material properties that do not change with functional decomposition, the stress distributions in the first calculations indicated higher stresses through the inner half of the myocardium and lower stresses through the outer half of the myocardium as compared to the second. This finding suggests that the inner fibers are overloaded and the outer fibers are underloaded in left ventricular decompensation. The difference between the first and second stress distributions averaged 26% (range: 11% to 48%). A useful, clinical, and quantitative measure of stress loading of the sarcomeres in functionally normal and abnormal left ventricles is proposed

Iraq and Afghanistan Veterans report symptoms consistent with chronic multisymptom illness one year after deployment

Many Veterans returning from service in Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) experience chronic pain. What is not known is whether for some OIF/OEF Veterans this pain is part of a larger condition of diffuse multisystem symptoms consistent with chronic multisymptom illness (CMI). We use data from a prospective longitudinal study of OIF/OEF Veterans to determine the frequency of CMI. We found that 1 yr after deployment, 49.5% of OIF/OEF Veterans met criteria for mild to moderate CMI and 10.8% met criteria for severe CMI. Over 90% of Veterans with chronic pain met criteria for CMI. CMI was not completely accounted for either by posttraumatic stress disorder or by predeployment levels of physical symptoms. Veterans with symptoms consistent with CMI reported significantly worse physical health function than Veterans who did not report symptoms consistent with CMI. This study suggests that the presence of CMI should be considered in the evaluation of OIF/OEF Veterans. Further, it suggests that the pain management for these Veterans may need to be tailored to take CMI into consideration

A Comprehensive Survey of Hydrogen Chloride in the Galaxy

We report new observations of the fundamental $J=1-0$ transition of HCl (at 625.918GHz) toward a sample of 25 galactic star-forming regions, molecular clouds, and evolved stars, carried out using the Caltech Submillimeter Observatory. Fourteen sources in the sample are also observed in the corresponding H\tscl\ $J=1-0$ transition (at 624.978GHz). We have obtained clear detections in all but four of the targets, often in emission. Absorptions against bright background continuum sources are also seen in nine cases, usually involving a delicate balance between emission and absorption features. From RADEX modeling, we derive gas densities and HCl column densities for sources with HCl emission. HCl is found in a wide range of environments, with gas densities ranging from $10^5$ to $10^7$~cm$^{-3}$. The HCl abundance relative to H$_2$ is in the range of $(3-30)\times10^{-10}$. Comparing with the chlorine abundance in the solar neighborhood, this corresponds to a chlorine depletion factor of up to $\sim$400, assuming that HCl accounts for one third of the total chlorine in the gas phase. The [\tfcl]/[\tscl] isotopic ratio is rather varied, from unity to $\sim$5, mostly lower than the terrestrial value of 3.1. Such variation is highly localized, and could be generated by the nucleosynthesis in supernovae, which predicts a \tscl\ deficiency in most models. The lower ratios seen in W3IRS4 and W3IRS5 likely confine the progenitors of the supernovae to stars with relatively large mass (\ga25M_\sun) and high metallicity (Z$\sim$0.02).Comment: 11 pages, 5 figures, accepted by Ap

Structural Transitions and Global Minima of Sodium Chloride Clusters

In recent experiments on sodium chloride clusters structural transitions between nanocrystals with different cuboidal shapes were detected. Here we determine reaction pathways between the low energy isomers of one of these clusters, (NaCl)35Cl-. The key process in these structural transitions is a highly cooperative rearrangement in which two parts of the nanocrystal slip past one another on a {110} plane in a direction. In this way the nanocrystals can plastically deform, in contrast to the brittle behaviour of bulk sodium chloride crystals at the same temperatures; the nanocrystals have mechanical properties which are a unique feature of their finite size. We also report and compare the global potential energy minima for (NaCl)NCl- using two empirical potentials, and comment on the effect of polarization.Comment: extended version, 13 pages, 8 figures, revte

Hydrophobic and ionic-interactions in bulk and confined water with implications for collapse and folding of proteins

Water and water-mediated interactions determine thermodynamic and kinetics of protein folding, protein aggregation and self-assembly in confined spaces. To obtain insights into the role of water in the context of folding problems, we describe computer simulations of a few related model systems. The dynamics of collapse of eicosane shows that upon expulsion of water the linear hydrocarbon chain adopts an ordered helical hairpin structure with 1.5 turns. The structure of dimer of eicosane molecules has two well ordered helical hairpins that are stacked perpendicular to each other. As a prelude to studying folding in confined spaces we used simulations to understand changes in hydrophobic and ionic interactions in nano droplets. Solvation of hydrophobic and charged species change drastically in nano water droplets. Hydrophobic species are localized at the boundary. The tendency of ions to be at the boundary where water density is low increases as the charge density decreases. Interaction between hydrophobic, polar, and charged residue are also profoundly altered in confined spaces. Using the results of computer simulations and accounting for loss of chain entropy upon confinement we argue and then demonstrate, using simulations in explicit water, that ordered states of generic amphiphilic peptide sequences should be stabilized in cylindrical nanopores

Corporate governance and inequality: The impact of financialization and shareholder value

Copyright © 2017 by Emerald Group Publishing Limited. Purpose - The purpose of this chapter is to analyse how in recent years the rediscovery that extreme inequality is returning to advanced economies and has become widespread. What is at issue are the causes of this inequality. It is becoming clear that the wider population, particularly in Anglo-American economies have not shared in the growing wealth of the countries concerned, and that the majority of this wealth is being transferred on a continuous and systemic basis to the very rich. Corporate governance and the pursuit of shareholder value it is argued has become a major driver of inequality. Methodology/approach - The current statistical evidence produced by leading authorities including the US Federal Reserve, World Economic Forum, Credit Suisse and Oxfam are examined. The policy of shareholder value and the mechanisms by which the distributions from business take place are investigated from a critical perspective. Findings - While the Anglo-American economies are seeing a return to the extremes of inequality last witnessed in the 19th century, the causes of this inequality are changing. In the 19th century great fortunes often were inherited, or derived by entrepreneurs from the ownership and control of productive assets. By the late 20th century as Atkinson, Piketty and Saez (2011) and others have highlighted, the sustained and rapid inflation in top income shares have made a significant contribution to the accelerating rate of income and wealth inequality. Research implications - The intensification of inequality in advanced industrial economies, despite the consistent work of Atkinson and others, was largely neglected until the recent research of Picketty which has attracted international attention. It is now acknowledged widely that inequality is a serious issue; however, the contemporary causes of inequality remain largely unexplored. Practical/social implications - The significance of inequality, now that it is recognized, demands policy and practical interventions. However, the capacity or even willingness to intervene is lacking. Further analysis of the debilitating consequences of inequality in terms of the efficiency and stability of economies and societies may encourage a more robust approach, yet the resolve to end extreme inequality is not present. Originality/value - The analysis of inequality has not been neglected and this chapter represents a pioneering effort to relate the shareholder value orientation now dominant in corporate governance to the intensification of inequality

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

Creating positive environmental impact through citizen science

Interest in citizen science is growing, including from governments and research funders. This interest is often driven by a desire for positive environmental impact, and the expectation that citizen science can deliver it by engaging the public and simultaneously collecting environmental data. Yet, in practice, there is often a gap between expected and realised impact. To close this gap, we need to better understand pathways to impact and what it takes to realise them. We articulate six key pathways through which citizen science can create positive environmental change: (1) environmental management; (2) evidence for policy; (3) behaviour change; (4) social network championing; (5) political advocacy; and (6) community action. We explore the project attributes likely to create impact through each of these pathways and show that there is an interplay between these project attributes and the needs and motivations of target participant groups. Exploring this interplay, we create a framework that articulates four citizen science approaches that create environmental impact in different ways: place-based community action; interest group investigation; captive learning research; and mass participation census