1,083 research outputs found
Economics, Politics, and the International Principles for Sound Compensation Practices: An Analysis of Executive Pay at European banks
In this Article, we submit that the compensation structures at banks before the financial crisis were not necessarily flawed and that recent reforms in this area largely reflect already existing best practices. In Part I we review recent empirical studies on corporate governance and executive pay at banks and suggest that there is no strong support for regulating bankers\u27 compensation structures. We also argue that detailed regulation of incentives would subtract essential decisionmaking powers from boards of directors and make compensation structures too rigid.
In Part II we note that political support for regulating bankers\u27 pay has been strong and led to reforms promoting long- term incentives to executives on the assumption that short-term incentives were a cause of the crisis. The Financial Stability Board Principles for Sound Compensation Practices (the Principles\u27) follow this trend, at the same time representing a political compromise between the various interest groups concerned. They pick up traditional compensation criteria from pre-crisis best practices, adapting them to the post-crisis setting, while leaving some flexibility in pay structures. We suggest that a certain degree of flexibility should be kept when implementing the Principles in national jurisdictions.
In Part III we analyze the regulatory developments concerning executive pay at banks in Europe and find variations in the implementation of the Principles. We also show that remuneration policies at large European banks are converging toward the international Principles, while varying in the implementation of individual standards. However, recent EU reforms may change the situation considerably by imposing detailed requirements as to pay structures in the financial sector. The analysis in Parts I, II, and III speaks directly to this issue by explaining why historic baselines will prove effective in certain applications but decidedly problematic in others
2,7-Bis(trichloromethyl)-1,8-naphthyridine1
The complete molecule of the title compound, C10H4Cl6N2, is generated by crystallographic twofold symmetry, with two C atoms lying on the rotation axis; the 1,8-naphthyridine ring is almost planar with an r.m.s. deviation of 0.0002 Å. In the crystal structure, the molecules are stacked in an antiparallel manner along [001]. Short Cl⋯Cl [3.3502 (4)] and Cl⋯N [3.2004 (11)–3.2220 (10) Å] contacts are observed in the crystal structure
Immunohistochemical evidence of a cytokine and chemokine network in three patients with Erdheim-Chester disease: Implications for pathogenesis.
OBJECTIVE:
Erdheim-Chester disease (ECD) is a rare form of non-Langerhans' cell histiocytosis (LCH) of unknown etiology, characterized by diffuse histiocyte infiltration of bones and soft tissue. The purpose of this study was to assess cell proliferation and expression of cytokines, chemokines, and chemokine receptors that may potentially be important in histiocyte accumulation in ECD lesions.
METHODS:
Biopsies were performed on 3 patients with ECD. The diagnosis of the disease was based on clinical signs including typical radiologic osteosclerosis, and on the detection of foamy CD68+,CD1a- non-Langerhans' cell histiocytes on histologic examination. The expression of the proliferation marker Ki-67 as well as of selected chemokine/chemokine receptor pairs and cytokines was analyzed by immunohistochemistry.
RESULTS:
In all samples, Ki-67 was undetectable in CD68+ histiocytes. Conversely, these cells expressed the chemokines CCL2 (monocyte chemotactic protein 1), CCL4/macrophage inflammatory protein 1beta (MIP-1beta), CCL5/RANTES, CCL20/MIP-3alpha, and CCL19/MIP-3beta, and their counter-receptors CCR1, CCR2, CCR3, CCR5, CCR6, and CCR7. Moreover, ECD histiocytes expressed interferon-gamma-inducible 10-kd protein (CXCL10), which is specifically induced by interferon-gamma, and interleukin-6 and RANKL, which are both implicated in bone remodeling. Finally, all cases showed a Th1-type lymphocyte infiltrate.
CONCLUSION:
Our data indicate that, similar to LCH, ECD lesions are characterized by a complex cytokine and chemokine network, which may orchestrate histiocyte activation and accumulation through an autocrine loop and contribute to the pathogenesis of the disease
Higher moment models for risk and portfolio management
This thesis considers specific topics related to the dynamic modelling and management of risk, with a particular emphasis on the generation of asymmetric and fat tailed behavior observed in practise. Specifically, extensions to the dynamics of the popular GARCH model, to capture time variation in higher moments, are considered in the univariate and multivariate context, with a special focus on the Generalized Hyperbolic distribution. In Chapter 1, I consider the extension of univariate GARCH processes with higher moment dynamics based on the Autoregressive Conditional Density model of Hansen (1994), with conditional distribution the Generalized Hyperbolic. The value of such dynamics are analyzed in the context of risk management, and the question of ignoring them discussed. In Chapter 2, I review some popular multivariate GARCH models with a particular emphasis on the dynamic correlation model of Engle (2002), and alternative distributions such those from the Generalized Asymmetric Laplace of Kotz, Kozubowski, and Podgorski (2001). In Chapter 3, I propose a multivariate extension to the Autoregressive Conditional Density model via the independence framework of the Generalized Orthogonal GARCH models, providing the first feasible model for large dimensional multivariate modelling of time varying higher moments. A comprehensive out-of- sample risk and portfolio management application provides strong evidence of the improvement over non time varying higher moments. Finally, in Chapter 4, I consider the benefits of active investing when the benchmark index is not optimally weighted. I investigate advances in the definition and use of risk measures in portfolio allocation, and propose certain simple solutions to challenges arising in the optimization of these measures. Combining the models discussed in the previous chapters, within a fractional programming optimization framework and using a range of popular risk measures, a large scale out-of-sample portfolio application on the point in time constituents of the Dow Jones Industrial Average is presented and discussed, with clear implications for active investing and benchmark policy choice.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Exploring the Role of Cell-Free Nucleic Acids and Peritoneal Dialysis: A Narrative Review
Introduction: Cell-free nucleic acids (cf-NAs) represent a promising biomarker of various pathological and physiological conditions. Since its discovery in 1948, cf-NAs gained prognostic value in oncology, immunology, and other relevant fields. In peritoneal dialysis (PD), blood purification is performed by exposing the peritoneal membrane. Relevant sections: Complications of PD such as acute peritonitis and peritoneal membrane aging are often critical in PD patient management. In this review, we focused on bacterial DNA, cell-free DNA, mitochondrial DNA (mtDNA), microRNA (miRNA), and their potential uses as biomarkers for monitoring PD and its complications. For instance, the isolation of bacterial DNA in early acute peritonitis allows bacterial identification and subsequent therapy implementation. Cell-free DNA in peritoneal dialysis effluent (PDE) represents a marker of stress of the peritoneal membrane in both acute and chronic PD complications. Moreover, miRNA are promising hallmarks of peritoneal membrane remodeling and aging, even before its manifestation. In this scenario, with multiple cytokines involved, mtDNA could be considered equally meaningful to determine tissue inflammation. Conclusions: This review explores the relevance of cf-NAs in PD, demonstrating its promising role for both diagnosis and treatment. Further studies are necessary to implement the use of cf-NAs in PD clinical practice
A new mechanism shapes the naïve CD8+ T cell repertoire: the selection for full diversity
During thymic T cell differentiation, TCR repertoires are shaped by negative, positive and agonist selection. In the thymus and in the periphery, repertoires are also shaped by strong inter-clonal and intra-clonal competition to survive death by neglect. Understanding the impact of these events on the T cell repertoire requires direct evaluation of TCR expression in peripheral naïve T cells. Several studies have evaluated TCR diversity, with contradictory results. Some of these studies had intrinsic technical limitations since they used material obtained from T cell pools, preventing the direct evaluation of clone sizes. Indeed with these approaches, identical TCRs may correspond to different cells expressing the same receptor, or to several amplicons from the same T cell. We here overcame this limitation by evaluating TCRB expression in individual naïve CD8+ T cells. Of the 2269 Tcrb sequences we obtained from 13 mice, 99% were unique. Mathematical analysis of this data showed that the average number of naïve peripheral CD8+ T cells expressing the same TCRB is 1.1 cell. Since TCRA co-expression studies could only increase repertoire diversity, these results reveal that the number of naïve T cells with unique TCRs approaches the number of naïve cells. Since thymocytes undergo multiple rounds of divisions after TCRB rearrangement; and 3–5% of thymocytes survive thymic selection events; the number of cells expressing the same TCRB was expected to be much higher. Thus, these results suggest a new repertoire selection mechanism, which strongly selects for full TCRB diversity
Sampling from T cell receptor repertoires
Modern single-cell sequencing techniques allow the unique TCR signature of each of a sample of hundreds of T cells to be read. The mathematical challenge is to extrapolate from the properties of a sample to those of the whole repertoire of an individual, made up of many millions of T cells. We consider the distribution of the number of repeats of any TCR in a sample, the mean number of samples needed to find a repeat with probability one half, and the relationship between the true distribution of clonal sizes and that experimentally observed in the sample. We consider two special cases, where the distribution of clonal sizes is geometric, and where a subset of clones in the repertoire is expanded
Principal molecular axis and transition dipole moment orientations in liquid crystal systems: an assessment based on studies of guest anthraquinone dyes in a nematic host
An assessment of five different definitions of the principal molecular axis along which molecules align in a nematic liquid crystal system has been made by analysing fully atomistic molecular dynamics (MD) simulations of a set of anthraquinone dyes in the cyanobiphenyl-based nematic host mixture E7. Principal molecular axes of the dyes defined by minimum moment of inertia, minimum circumference, minimum area, maximum aspect ratio, and surface tensor models were tested, and the surface tensor model was found to give the best description. Analyses of MD simulations of E7 alone showed that the surface tensor model also gave a good description of the principal molecular axes of the host molecules, suggesting that this model may be applicable more generally. Calculated dichroic order parameters of the guest-host systems were obtained by combining the surface tensor analysis with fixed transition dipole moment (TDM) orientations from time-dependent density functional theory (TD-DFT) calculations on optimised structures of the dyes, and the trend between the dyes generally matched the trend in the experimental values. Additional analyses of the guest-host simulations identified the range of conformers explored by the flexible chromophores within the dyes, and TD-DFT calculations on corresponding model structures showed that this flexibility has a significant effect on the TDM orientations within the molecular frames. Calculated dichroic order parameters that included the effects of this flexibility gave a significantly improved match with the experimental values for the more flexible dyes. Overall, the surface tensor model has been shown to provide a rationale for the experimental alignment trends that is based on molecular shape, and molecular flexibility within the chromophores has been shown to be significant for the guest-host systems: The computational approaches reported here may be used as a general aid in the predictive design of dyes with appropriate molecular shapes and flexibilities for guest-host applications
- …