Binomial Ideals and Congruences on Nn

Producción CientíficaA congruence on Nn is an equivalence relation on Nn that is compatible with the additive structure. If k is a field, and I is a binomial ideal in k[X1,…,Xn] (that is, an ideal generated by polynomials with at most two terms), then I induces a congruence on Nn by declaring u and v to be equivalent if there is a linear combination with nonzero coefficients of Xu and Xv that belongs to I. While every congruence on Nn arises this way, this is not a one-to-one correspondence, as many binomial ideals may induce the same congruence. Nevertheless, the link between a binomial ideal and its corresponding congruence is strong, and one may think of congruences as the underlying combinatorial structures of binomial ideals. In the current literature, the theories of binomial ideals and congruences on Nn are developed separately. The aim of this survey paper is to provide a detailed parallel exposition, that provides algebraic intuition for the combinatorial analysis of congruences. For the elaboration of this survey paper, we followed mainly (Kahle and Miller Algebra Number Theory 8(6):1297–1364, 2014) with an eye on Eisenbud and Sturmfels (Duke Math J 84(1):1–45, 1996) and Ojeda and Piedra Sánchez (J Symbolic Comput 30(4):383–400, 2000).National Science Foundation (grant DMS-1500832)Ministerio de Economía, Industria y Competitividad (project MTM2015-65764-C3-1)Junta de Extremadura (grupo de investigación FQM-024

What Is Influencing Financially-Driven Shareholder Activism in the US and UK—Principal-Agent or Principal-Principal Problems?

Shareholder activism is a response to corporate underperformance by one or more shareholders of the corporation. Classic agency theory suggests that shareholder activism is a mechanism to curb principal-agent problems in the firm. However, the principal-principal perspective suggests that shareholder activism is a mechanism for dominant shareholders to extract resources from the firm. This dissertation extends the current research by developing and testing competing hypotheses to examine the antecedents of financially driven shareholder activism in the United States and the United Kingdom. The extant literature on financially driven shareholder activism (FDSA) is reviewed, research gaps in the literature identified and a new model of shareholder activism is introduced. Agency theory and the principal-principal perspective are used to develop eight hypotheses, which are empirically tested. Findings show that several proxies for the principal-principal perspective are better predictors of FDSA than proxies from the principal-agent perspective. The study also shows a positive relationship between FDSA and changes in long-term market-based performance, a principal-agency prediction. The results also show that the relationship between FDSA and change in subsequent firm performance is moderated by governance environment. This study provides evidence that the principal-principal problems are not just found in emerging market countries as previous studies show, but are also a problem in developed countries like the US and the UK. In addition, this study suggests that agency theory is limited in its explanatory power. For policymakers, this study questions whether shareholder activism can act as an effective method to monitor corporate management

A Recursion-Theoretic Characterization of the Probabilistic Class PP

Probabilistic complexity classes, despite capturing the notion of feasibility, have escaped any treatment by the tools of so-called implicit-complexity. Their inherently semantic nature is of course a barrier to the characterization of classes like BPP or ZPP, but not all classes are semantic. In this paper, we introduce a recursion-theoretic characterization of the probabilistic class PP, using recursion schemata with pointers

Did Board Configuration Matter? The Case of US Subprime Lenders

Research Question/Issue: The origins of the global financial crisis have been attributed to the combination of a housing price bubble and innovative financial instruments, as well as the lack of restraint by corporate executives and boards to engage in excessive risk-taking. The rise in subprime lending between 1997 and 2005 played a crucial role in inflating the housing price bubble. We take a unique dataset of US financial institutions heavily engaged in subprime lending and ask the following research question: Did board configuration play a role in determining whether a financial institution specialized in subprime lending? Research Findings/Insights: We use a matched-pair sample of firms in the financial industry from 1997-2005 with half of the sample specializing in subprime lending and conduct panel data logistic regression analysis. We find that the board configurations of those financial institutions that engaged in subprime lending were significantly different from those that did not. Specifically, subprime lenders had boards that were busier, had less tenure, and were less diverse with respect to gender. Theoretical/Academic Implications: This study uses the group decision making perspective in the context of subprime lending to examine board of director configuration and its influence on decision making processes around the issue of risky subprime lending. Findings show that how boards were configured did influence the decision to specialize in subprime lending. We find robust support for predictions based on the group decision making perspective. Practitioner/Policy Implications: The deterioration of mortgage lending requirements that gave rise to the defaults of so many subprime loans, in retrospect, appears to be something that should have been entirely preventable. By demonstrating that subprime specialists had significant differences in board configuration that impacted group decision making, this study offers guidance to policymakers considering additional regulation and for corporate officers examining corporate governance issues

Complexity Measures from Interaction Structures

We evaluate new complexity measures on the symbolic dynamics of coupled tent maps and cellular automata. These measures quantify complexity in terms of $k$-th order statistical dependencies that cannot be reduced to interactions between $k-1$ units. We demonstrate that these measures are able to identify complex dynamical regimes.Comment: 11 pages, figures improved, minor changes to the tex

G08-1376 Drinking Water: Fluoride

At optimal levels, fluoride in drinking water can be beneficial to dental health. Learn more about fluoride concentration and potential health effects in this 2008 NebGuide

What Are The Correlates of Interdisciplinary Research Impact? The Case of Corporate Governance Research

We explore the concept of interdisciplinary research impact and better understand what factors might be associated with it. Using the field of corporate governance research as a case study and linking our research impact concept to a novel measure of scholarly citation rates, we seek to understand why some corporate governance scholars are cited more than others. We first developed a comprehensive ranking of the top-100 scholars cited for their research in corporate governance and then compared that high-impact group with scholars who had published governance research that was not yet cited. We hypothesized that indicators from the social network perspective would be predictive of interdisciplinary research impact. Our data largely supported our hypotheses using this new and improved measure of research impact, and robustness tests also supported our results

FAS-dependent cell death in α-synuclein transgenic oligodendrocyte models of multiple system atrophy

Multiple system atrophy is a parkinsonian neurodegenerative disorder. It is cytopathologically characterized by accumulation of the protein p25α in cell bodies of oligodendrocytes followed by accumulation of aggregated α-synuclein in so-called glial cytoplasmic inclusions. p25α is a stimulator of α-synuclein aggregation, and coexpression of α-synuclein and p25α in the oligodendroglial OLN-t40-AS cell line causes α-synuclein aggregate-dependent toxicity. In this study, we investigated whether the FAS system is involved in α-synuclein aggregate dependent degeneration in oligodendrocytes and may play a role in multiple system atrophy. Using rat oligodendroglial OLN-t40-AS cells we demonstrate that the cytotoxicity caused by coexpressing α-synuclein and p25α relies on stimulation of the death domain receptor FAS and caspase-8 activation. Using primary oligodendrocytes derived from PLP-α-synuclein transgenic mice we demonstrate that they exist in a sensitized state expressing pro-apoptotic FAS receptor, which makes them sensitive to FAS ligand-mediated apoptosis. Immunoblot analysis shows an increase in FAS in brain extracts from multiple system atrophy cases. Immunohistochemical analysis demonstrated enhanced FAS expression in multiple system atrophy brains notably in oligodendrocytes harboring the earliest stages of glial cytoplasmic inclusion formation. Oligodendroglial FAS expression is an early hallmark of oligodendroglial pathology in multiple system atrophy that mechanistically may be coupled to α-synuclein dependent degeneration and thus represent a potential target for protective intervention

Workflow Engineering in Materials Design within the BATTERY 2030+Project

In recent years, modeling and simulation of materials have become indispensable to complement experiments in materials design. High-throughput simulations increasingly aid researchers in selecting the most promising materials for experimental studies or by providing insights inaccessible by experiment. However, this often requires multiple simulation tools to meet the modeling goal. As a result, methods and tools are needed to enable extensive-scale simulations with streamlined execution of all tasks within a complex simulation protocol, including the transfer and adaptation of data between calculations. These methods should allow rapid prototyping of new protocols and proper documentation of the process. Here an overview of the benefits and challenges of workflow engineering in virtual material design is presented. Furthermore, a selection of prominent scientific workflow frameworks used for the research in the BATTERY 2030+ project is presented. Their strengths and weaknesses as well as a selection of use cases in which workflow frameworks significantly contributed to the respective studies are discussed

Оценка надежности высоконадежных систем с учетом ЗИП

Предложены приближенные верхние и нижние оценки коэффициента готовности высоконадежной восстанавливаемой системы со структурной избыточностью. Полученные расчетные соотношения могут использоваться для оценки надежности высоконадежных систем с учетом различных стратегий пополнения ЗИП