8,203 research outputs found

    Disciplining and Screening Top Executives

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    Boards of directors face the twin task of disciplining and screening executives. To perform these tasks directors do not have detailed information about executives' behaviour, and only infrequently have information about the success or failure of initiated strategies, reorganizations, mergers etc. We analyse the nature of (implicit) retention contracts boards use to discipline and screen executives. Consistent with empirical observation, we find that executives may become overly active to show their credentials; that the link between bad performance and dismissal is weak; and that boards occasionally dismiss competent executives

    In Defense of Boards

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    It is often assumed that bad corporate performance means a bad CEO. The task of a board of directors is then simple: dismiss the executive. If it fails to do so, the board is said to be indolent. We take a kinder approach to observed board behaviour and point to the problems even well-intended boards would encounter. They face the twin task of disciplining and screening executives. To perform these tasks directors do not have detailed information about executives behaviour, and only infrequently hav

    Wear Behavior of a Ni/Co Bilayer Coating by Physical Vapor Deposition on AISI 1045 Steel

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    Coatings by physical vapor deposition (PVD) have become highly relevant due to their wide range of applications and the rapid rate of coating formation. In this work, AISI steel 1045 was coated with two layers, Ni and Co using the PVD technique. Each coating was deposited with a thickness of 1 μm. After applying the coatings, a post-treatment was applied in an AC plasma reactor using a boron nitride blank in an Ar atmosphere at a pressure of 3 Torr, 0.3 A, and 460 V at 4, 8, and 12h. The post-treatment was characterized by optical emission spectroscopy (OES) in a range of 200-1100 nm. The main species observed by OES were Ar+, N2, N2+, and B+. The coatings on 1045 steel and posttreatment were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Also, were subjected to tribological tests to analyze wear resistance, using the Pin-on-Disk technique. The coatings on steel 1045 present remarkably better wear properties than the uncoated 1045 steel, being the sample post-treated at 4h that showed a lower wear rate

    Técnicas terapéuticas endovasculares

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    Percutaneous and endovascular techniques have shown their efficacy in the treatment of a great variety of pathologies. The advances in diagnostic imaging as well as the development of new materials have made it possible to carry out new procedures that were unthinkable not many years ago. The irruption of this new form of treating patients has had, is having, and will have a clear impact on the multidisciplinary approach to numerous diseases

    Internal mammary artery dilatation in a patient with aortic coarctation, aortic stenosis, and coronary disease. Case report

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    The ideal surgical approach is unclear in adult patients with coarctation of the aorta that is associated with other cardiovascular pathologies that require intervention. Standard median sternotomy allows simultaneous, coronary revascularization surgery, valve replacement and repair of aortic coarctation. However the collateral circulation and the anatomy of the mammary arteries must be determined, to avoid possible complications. We report a case of a 69 year-old man with aortic coarctation, aortic stenosis, coronary artery disease and internal mammary artery dilatation who underwent concomitant surgical procedures through a median sternotomy

    Breast Cancer Mortality in Older and Younger Patients in California

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    BACKGROUND: Breast cancer in younger patients is reported to be more aggressive and associated with lower survival; however, factors associated with age-specific mortality differences have not been adequately assessed. METHODS: We used data from the population-based California Cancer Registry for 38,509 younger (18-49 years) and 121,573 older (50 years and older) women diagnosed with stage I to III breast cancer, 2005-2014. Multivariable Cox regression models were used to estimate breast cancer-specific mortality rate ratios (MRR) and 95% confidence intervals (CI), stratified by tumor subtype, guideline treatment, and care at an NCI-designated cancer center (NCICC). RESULTS: Older breast cancer patients at diagnosis experienced 17% higher disease-specific mortality than younger patients, after multivariable adjustment (MRR = 1.17; 95% CI, 1.11-1.23). Higher MRRs (95% CI) were observed for older versus younger patients with hormone receptor (HR)(+)/HER2(-) (1.24; 1.14-1.35) and HR(+)/HER2(+) (1.38; 1.17-1.62), but not for HR(-)/HER2(+) (HR = 0.94; 0.79-1.12) nor triple-negative breast cancers (1.01; 0.92-1.11). The higher mortality in older versus younger patients was diminished among patients who received guideline-concordant treatment (MRR = 1.06; 95% CI, 0.99-1.14) and reversed among those seen at an NCICC (MRR = 0.86; 95% CI, 0.73-1.01). CONCLUSIONS: Although younger women tend to be diagnosed with more aggressive breast cancers, adjusting for these aggressive features results in older patients having higher mortality than younger patients, with variations by age, tumor subtype, receipt of guideline treatment, and being cared for at an NCICC. IMPACT: Higher breast cancer mortality in older compared with younger women could partly be addressed by ensuring optimal treatment and comprehensive patient-centered care

    DualSPHysics: from fluid dynamics to multiphysics problems

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    DualSPHysics is a weakly compressible smoothed particle hydrodynamics (SPH) Navier–Stokes solver initially conceived to deal with coastal engineering problems, especially those related to wave impact with coastal structures. Since the first release back in 2011, DualSPHysics has shown to be robust and accurate for simulating extreme wave events along with a continuous improvement in efficiency thanks to the exploitation of hardware such as graphics processing units for scientific computing or the coupling with wave propagating models such as SWASH and OceanWave3D. Numerous additional functionalities have also been included in the DualSPHysics package over the last few years which allow the simulation of fluid-driven objects. The use of the discrete element method has allowed the solver to simulate the interaction among different bodies (sliding rocks, for example), which provides a unique tool to analyse debris flows. In addition, the recent coupling with other solvers like Project Chrono or MoorDyn has been a milestone in the development of the solver. Project Chrono allows the simulation of articulated structures with joints, hinges, sliders and springs and MoorDyn allows simulating moored structures. Both functionalities make DualSPHysics especially suited for the simulation of offshore energy harvesting devices. Lately, the present state of maturity of the solver goes beyond single-phase simulations, allowing multi-phase simulations with gas–liquid and a combination of Newtonian and non-Newtonian models expanding further the capabilities and range of applications for the DualSPHysics solver. These advances and functionalities make DualSPHysics an advanced meshless solver with emphasis on free-surface flow modelling

    Decision Making with Asymmetric Information

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    Every day individuals make numerous choices. What is important for making the right choice is that individuals have good information about the consequences of the different alternatives. However, investigating the full consequences of the different alternatives is complicated and costly. Consequently, individuals sometimes do not possess all relevant information to take a decision. This thesis discusses models in which an agent decides whether or not to perform a task on behalf of the principal. A key element in the models we consider is incomplete and asymmetric information. Broadly, the thesis can be split up into two parts. The first part of the thesis deals with models in which the principal is better informed than the agent. The agent has to decide whether or not to perform a task, but lacks information about his ability. We analyze how the agent makes a self-assessment of his ability, based on appraisals of others (the principal) and experience. Based on this self-assessment the agent takes a decision. The second part of the thesis deals with models in which the agent is better informed than the principal. On behalf of the principal the agent takes a decision about a project. Sometimes agents do not act in the interest of the principal. We analyze how the principal can use retention contracts to discipline the agent. In the remainder of the Introduction we discuss the two parts of the thesis and we provide an overview of the chapters of this thesis

    On the Role of Pre-Determined Rules for HRM Policies

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    Using simple game-theoretical models, this paper studies the role of pre-determined rules for HRM policies. We consider a model in which HRM decisions affect employees' self-images and thereby their motivation. We show that in the absence of written rules, managers are too reluctant (1) to differentiate between employees on the basis of their abilities, and (2) to terminate employment of employees on probation. Generally, organizations benefit from committing to strict rules for various HRM practices

    An Approach to an Inhibition Electronic Tongue to Detect On-Line Organophosphorus Insecticides Using a Computer Controlled Multi-Commuted Flow System

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    An approach to an inhibition bioelectronic tongue is presented. The work is focused on development of an automated flow system to carry out experimental assays, a custom potentiostat to measure the response from an enzymatic biosensor, and an inhibition protocol which allows on-line detections. A Multi-commuted Flow Analysis system (MCFA) was selected and developed to carry out assays with an improved inhibition method to detect the insecticides chlorpyrifos oxon (CPO), chlorfenvinfos (CFV) and azinphos methyl-oxon (AZMO). The system manifold comprised a peristaltic pump, a set of seven electronic valves controlled by a personal computer electronic interface and software based on LabView® to control the sample dilutions into the cell. The inhibition method consists in the injection of the insecticide when the enzyme activity has reached the plateau of the current; with this method the incubation time is avoided. A potentiostat was developed to measure the response from the enzymatic biosensor. Low limits of detection of 10 nM for CPO, CFV, and AZMO were achieved
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