Association between adolescent idiopathic scoliosis prevalence and age at menarche in different geographic latitudes

BACKGROUND: Age at menarche is considered a reliable prognostic factor for idiopathic scoliosis and varies in different geographic latitudes. Adolescent idiopathic scoliosis prevalence has also been reported to be different in various latitudes and demonstrates higher values in northern countries. A study on epidemiological reports from the literature was conducted to investigate a possible association between prevalence of adolescent idiopathic scoliosis and age at menarche among normal girls in various geographic latitudes. An attempt is also made to implicate a possible role of melatonin in the above association. MATERIAL-METHODS: 20 peer-reviewed published papers reporting adolescent idiopathic scoliosis prevalence and 33 peer-reviewed papers reporting age at menarche in normal girls from most geographic areas of the northern hemisphere were retrieved from the literature. The geographic latitude of each centre where a particular study was originated was documented. The statistical analysis included regression of the adolescent idiopathic scoliosis prevalence and age at menarche by latitude. RESULTS: The regression of prevalence of adolescent idiopathic scoliosis and age at menarche by latitude is statistically significant (p < 0.001) and are following a parallel declining course of their regression curves, especially in latitudes northern than 25 degrees. CONCLUSION: Late age at menarche is parallel with higher prevalence of adolescent idiopathic scoliosis. Pubarche appears later in girls that live in northern latitudes and thus prolongs the period of spine vulnerability while other pre-existing or aetiological factors are contributing to the development of adolescent idiopathic scoliosis. A possible role of geography in the pathogenesis of idiopathic scoliosis is discussed, as it appears that latitude which differentiates the sunlight influences melatonin secretion and modifies age at menarche, which is associated to the prevalence of idiopathic scoliosis

The Overconfidence Problem in Insurance Markets

Adverse selection has long been recognized as a rationale for government intervention in in- surance markets and for the adoption of public compulsory insurance. A different rationale for compulsory insurance is that overconfident individuals may underinsure because they underes- timate the relevant risks. We show that government intervention is not a Pareto improvement in an adverse selection model with a significant fraction of overcon�dent agents. We underline that behavioral biases need not be the basis for government intervention. In fact, behavioral biases may overturn existing compelling reasons for intervention in the economy. Our model also delivers novel positive implications on aggregate variables that have been at the center of recent empirical investigation

The effectiveness of boards of directors in two-tier board system: Evidence from Vietnamese-listed enterprises

This paper presents several theories to achieve a better understanding of corporate governance structures and their operations in a two-tier-board corporate governance structure. The author also analyses transitional economies using the case of Vietnam. The author investigates the influence of independent directors upon the probability of CEO turnover as well as the sensitivity of the link between performance and turnover. The findings show that non-executive directors are not always independent. At the same time, independent directors have a vital role to play in making decisions concerning CEO dismissal. These directors also reduce the effects of CEO ownership and CEO duality upon the probability of CEO turnover. In summation, the research found that performance and CEO age constitute key factors in CEO turnover, regardless of the corporation or board size

Enterprise Systems and Corporate Governance: Parallel and Interconnected Evolution, 26 J. Marshall J. Computer & Info. L. 359 (2009)

Today\u27s business requirements have moved Enterprise Systems ( ES ) governance into the focus of attention as they are necessary in supporting business processes in many organizations. Corporate Governance ( CG ) and ES constitute two seemingly dissimilar research areas that attract the interest of completely different academics as practitioners. However, at a time when there is an increasing focus on CG practices and the impact of ES on corporate performance, these topics are tightly connected and complimentary. Given the fact that ES can contribute positively in achieving business objectives, it is imperative to discuss the relationship of CG and information technology ( IT ). Moreover, the authors argue that good CG depends on effective management and integrity of information within an organization. This shift is being accelerated and influenced by the passage of the Sarbanes-Oxley Act (SOX) of 2002 in the United States ( U.S. ) and the Organization for Economic Co-Operation and Development ( OECD ) principles in Europe

Macroeconomic and industry-specific determinants of Greek bank profitability

Purpose: The purpose of this paper is to investigate the external factors that influence the profitability of a typical Greek systemic bank over the period 2001 – 2014. Design/Methodology/Approach: A conceptual framework incorporating two fundamental groups of const ructs, namely, macroeconomic forces and industry related factors, was developed. Two constructs were examined in the former: GDP growth rate and unemployment rate, whilst two attributes were explored in the latter; the bank's market share, both in terms of deposits and in terms of assets, and the banking market growth, also both in terms of the market's total assets and total deposits. In order to isolate the effects of the ongoing financial crisis, the research was undertaken for two periods, firstly 2001 to 2014 and secondly, the period 2001 - 2011, which excluded the deep recession. Consequently, multiple regression analysis was conducted and linear models were specified by means of OLS. Findings: The empirical analysis revealed that both macroeconomic forces and industry-related factors affect bank profitability. As far as the macroeconomic factors are concerned, unemployment rate has a negative impact, whereas the GDP growth rate has a positive impact on bank profitability. The industry -related factors, rate of growth of the industry's deposits and bank's assets market share have a positive impact on the financial performance of the bank. Finally, the rate of growth of the industry's assets and the bank's deposits market share have a negative effect on bank profitability. Originality/Value: This study reveals the mechanism determining bank profitability over a recent period that includes the financial crisis. Moreover, understanding the impact of macroeconomic forces as well as industry related attributes on bank profitability may enable banks to focus on the most critical factors in their decision process

Semantic querying of tree-structured data sources using partially specified tree patterns

Nowadays, huge volumes of data are organized or exported in a tree-structured form. Querying capabilities are pro-vided through queries that are based on branching path ex-pression. Even for a single knowledge domain structural differences raise difficulties for querying data sources in a uniform way. In this paper, we present a method for seman-tically querying tree-structured data sources using partially specified tree patterns. Based on dimensions which are sets of semantically related nodes in tree structures, we define dimension graphs. Dimension graphs can be automatically extracted from trees and abstract their structural informa-tion. They are semantically rich constructs that support the formulation of queries and their efficient evaluation. We design a tree-pattern query language to query multiple tree-structured data sources. A central feature of this language is that the structure can be specified fully, partially, or not at all in the queries. Therefore, it can be used to query multiple trees with structural differences. We study the derivation of structural expressions in queries by introducing a set of in-ference rules for structural expressions. We define two types of query unsatisfiability and we provide necessary and suffi-cient conditions for checking each of them. Our approach is validated through experimental evaluation