Corporate and Individual Influences on Managers\u27 Social Orientation

This paper reports research on the influence of corporate and individual characteristics on managers\u27 social orientation in Germany. The results indicate that mid-level managers expressed a significantly lower social orientation than low-level managers, and that job activity did not impact social orientation. Female respondents expressed a higher social orientation than male respondents. No impact of the political system origin (former East Germany versus former West Germany) on social orientation was shown. Overall, corporate position had a significantly higher impact on social orientation than did the characteristics of the individuals surveyed

Determinants of Medical Costs Following a Diagnosis of Depression

Objective: Assess the determinants of medical costs for depressed individuals. Method: Using medical insurance claims for a population of depressed individuals with employer provided insurance, we estimated multivariate models of the costs for general medical care, exclusive of costs for mental health services, following diagnosis. Explanatory variables included provider choice (psychiatrist or non-physician mental health specialist), treatment choice (medication, psychotherapy, or combination treatment); treatment adequacy as defined by APA guidelines; characteristics of depression symptoms and severity; and other demographic characteristics. Results: On average, there were increases in the costs for general medical services in the year following diagnosis of a depressive disorder. The increases in general medical costs were slightly higher when depressed persons received a treatment for depression when compared to those who did not receive a treatment for depression. Among those treated, there was no significant difference between those who received an adequate course of treatment when compared with those who did not. Significant predictors of high medical costs following diagnosis included choice of a non-psychiatrist as the initial provider, high pre-period medical costs, and several measures of severity. Conclusions: Our findings suggest that a diagnosis of depression is associated with increases in costs for general medical care. These increases are more modest when care is initially provided by a psychiatrist

Psychotherapy in Antidepressant Patients

Depression is a condition with various modes of treatment, including pharmacotherapy, psychotherapy, and some combination of each. The role of psychotherapy in the treatment of depression relative to the role of pharmacotherapy is not well understood, and guidelines for psychotherapy in the primary care setting differ from guidelines for specialty care. There is little evidence about the circumstances in actual practice that affect the use of psychotherapy in conjunction with pharmacotherapy. We retrospectively identify the most important factors associated with the use of psychotherapy in combination with pharmacotherapy in the treatment of depression. Specifically, we study provider choice, health plan characteristics, and patient characteristics. We use a comprehensive medical and pharmacy claims data sample of 1,023 individuals during 1992–1994. We select persons prescribed with an antidepressant medication and diagnosed with a depressive disorder by a primary care physician, psychiatrist, or non-physician mental health specialist. Controlling for depression diagnosis and severity, comorbidity, and demographics, we examine the role of provider type and plan benefit characteristics. We study the intensity of psychotherapy using zero-inflated count regression, the intensity of pharmacotherapy using truncated count regression, and the likelihood of relapse of depression using logistic regression. Patients initially seeing a psychiatrist receive more than double the amount of psychotherapy and slightly more pharmacotherapy than patients of other providers. An additional prescription for antidepressant medication reduces by five percent the likelihood of relapse into depression, but the amount of psychotherapy does not affect relapse. Patients seeing a psychiatrist are half as likely to relapse, independent of any effect of psychotherapy. Case management and coinsurance rates do not affect the amount of psychotherapy, but the presence of case management has a positive effect on the amount of pharmacotherapy and on the likelihood of relapse. We find no discernible pattern of complementarity or substitution between pharmacotherapy and psychotherapy across providers. Although the amount of psychotherapy provided in conjunction with medication does not affect the rate of relapse to depression, psychotherapy may nonetheless provide beneficial outcomes not studied here. Choice of a psychiatrist reduces the likelihood of relapse, independent of the number of psychotherapy sessions and antidepressant prescriptions. The effect of provider choice on relapse could be an artifact of differences in provider follow-up practices or could represent a difference in provider skills. Managed care strategies do not appear to reduce the intensity of depression treatment, but case management does increase the likelihood of relapse. Pharmacotherapy and psychotherapy appear to be neither substitutes nor complements in the treatment of depression, suggesting that treatment is individualized. Choice of psychiatrist as the initial provider appears to reduce the likelihood of relapse, suggesting models of coordinated care may be beneficial. The link between psychiatrists and more psychotherapy is consistent with the hypothesis that patients resistant to treatment may nonetheless receive high quality care. Managed care tools such as case management and coinsurance rates do not appear to restrict the use of either psychotherapy or pharmacotherapy. The association of case management with an increased likelihood of relapse suggests that plan characteristics can affect outcomes. Our study focuses on psychotherapy combined with medication and does not psychotherapy alone in the treatment of depression, which may be a preferred mode of treatment for some. Outcomes other than relapse, as well as costs, should also be considered. Our findings that psychiatrists are associated with a decreased likelihood of relapse and that case management is associated with an increased likelihood of relapse despite a correlation with greater pharmacotherapy intensity present avenues for additional study

Provider Type and Depression Treatment Adequacy

We investigate the effect of initial provider (primary care physician, psychiatrist, or non-physician mental health specialist) on the adequacy of subsequent treatment for persons with depression. Our data are from MarketScan®, a medical and pharmacy insurance claims database, which we use to estimate models of the likelihood of treatment for depression and the likelihood that any treatment received is adequate. Patients initially seeing psychiatrists are most likely to receive adequate treatment. Provider type has a statistically and medically significant effect on whether any treatment occurs but a smaller effect on treatment adequacy among treated patients. The results show the importance of provider type in treatment patterns, but the effects on patient outcomes are yet to be determined definitively

Beating patterns of filaments in viscoelastic fluids

Many swimming microorganisms, such as bacteria and sperm, use flexible flagella to move through viscoelastic media in their natural environments. In this paper we address the effects a viscoelastic fluid has on the motion and beating patterns of elastic filaments. We treat both a passive filament which is actuated at one end, and an active filament with bending forces arising from internal motors distributed along its length. We describe how viscoelasticity modifies the hydrodynamic forces exerted on the filaments, and how these modified forces affect the beating patterns. We show how high viscosity of purely viscous or viscoelastic solutions can lead to the experimentally observed beating patterns of sperm flagella, in which motion is concentrated at the distal end of the flagella

Vesicle shape, molecular tilt, and the suppression of necks

Can the presence of molecular-tilt order significantly affect the shapes of lipid bilayer membranes, particularly membrane shapes with narrow necks? Motivated by the propensity for tilt order and the common occurrence of narrow necks in the intermediate stages of biological processes such as endocytosis and vesicle trafficking, we examine how tilt order inhibits the formation of necks in the equilibrium shapes of vesicles. For vesicles with a spherical topology, point defects in the molecular order with a total strength of $+2$ are required. We study axisymmetric shapes and suppose that there is a unit-strength defect at each pole of the vesicle. The model is further simplified by the assumption of tilt isotropy: invariance of the energy with respect to rotations of the molecules about the local membrane normal. This isotropy condition leads to a minimal coupling of tilt order and curvature, giving a high energetic cost to regions with Gaussian curvature and tilt order. Minimizing the elastic free energy with constraints of fixed area and fixed enclosed volume determines the allowed shapes. Using numerical calculations, we find several branches of solutions and identify them with the branches previously known for fluid membranes. We find that tilt order changes the relative energy of the branches, suppressing thin necks by making them costly, leading to elongated prolate vesicles as a generic family of tilt-ordered membrane shapes.Comment: 10 pages, 7 figures, submitted to Phy. Rew.

Recent Applications of Higher-Order Spectral Analysis to Nonlinear Aeroelastic Phenomena

Recent applications of higher-order spectral (HOS) methods to nonlinear aeroelastic phenomena are presented. Applications include the analysis of data from a simulated nonlinear pitch and plunge apparatus and from F-18 flight flutter tests. A MATLAB model of the Texas A&MUniversity s Nonlinear Aeroelastic Testbed Apparatus (NATA) is used to generate aeroelastic transients at various conditions including limit cycle oscillations (LCO). The Gaussian or non-Gaussian nature of the transients is investigated, related to HOS methods, and used to identify levels of increasing nonlinear aeroelastic response. Royal Australian Air Force (RAAF) F/A-18 flight flutter test data is presented and analyzed. The data includes high-quality measurements of forced responses and LCO phenomena. Standard power spectral density (PSD) techniques and HOS methods are applied to the data and presented. The goal of this research is to develop methods that can identify the onset of nonlinear aeroelastic phenomena, such as LCO, during flutter testing

Rigid Chiral Membranes

Statistical ensembles of flexible two-dimensional fluid membranes arise naturally in the description of many physical systems. Typically one encounters such systems in a regime of low tension but high stiffness against bending, which is just the opposite of the regime described by the Polyakov string. We study a class of couplings between membrane shape and in-plane order which break 3-space parity invariance. Remarkably there is only {\it one} such allowed coupling (up to boundary terms); this term will be present for any lipid bilayer composed of tilted chiral molecules. We calculate the renormalization-group behavior of this relevant coupling in a simplified model and show how thermal fluctuations effectively reduce it in the infrared.Comment: 11 pages, UPR-518T (This replaced version has fonts not used removed.

Inactivation of the Pta-AckA Pathway Causes Cell Death in \u3ci\u3eStaphylococcus aureus\u3c/i\u3e

During growth under conditions of glucose and oxygen excess, Staphylococcus aureus predominantly accumulates acetate in the culture medium, suggesting that the phosphotransacetylase-acetate kinase (Pta-AckA) pathway plays a crucial role in bacterial fitness. Previous studies demonstrated that these conditions also induce the S. aureus CidR regulon involved in the control of cell death. Interestingly, the CidR regulon is comprised of only two operons, both encoding pyruvate catabolic enzymes, suggesting an intimate relationship between pyruvate metabolism and cell death. To examine this relationship, we introduced ackA and pta mutations in S. aureus and tested their effects on bacterial growth, carbon and energy metabolism, cid expression, and cell death. Inactivation of the Pta-AckA pathway showed a drastic inhibitory effect on growth and caused accumulation of dead cells in both pta and ackA mutants. Surprisingly, inactivation of the Pta-AckA pathway did not lead to a decrease in the energy status of bacteria, as the intracellular concentrations of ATP, NAD+, and NADH were higher in the mutants. However, inactivation of this pathway increased the rate of glucose consumption, led to a metabolic block at the pyruvate node, and enhanced carbon flux through both glycolysis and the tricarboxylic acid (TCA) cycle. Intriguingly, disruption of the Pta-AckA pathway also induced the CidR regulon, suggesting that activation of alternative pyruvate catabolic pathways could be an important survival strategy for the mutants. Collectively, the results of this study demonstrate the indispensable role of the Pta-AckA pathway in S. aureus for maintaining energy and metabolic homeostasis during overflow metabolism