Excessively pronated feet: a health hazard to developing children

There is a serious misconception on the part of the public as well as amongst a great number of professionals to equate the problem of flatfoot with excessively pronated feet in growing children. This is a matter of grave concern since flatness of the arch of the foot can be a normal or abnormal finding in foot posture, whereas the excessively pronated foot is flattened as part of a pathological structural malposition. This inherent biomechanical defect is commonly present in the great majority of human children and is the basic reason for most postural pathology of the lower extremity.Excessive pronation of the feet in children should in no way be interpreted as a normal condition to be automatically outgrown. As a matter of fact, Whitman, the famous Orthopaedic Surgeon, noted in 1917 in his text Orthopaedic Surgery that pronation of the feet commonly seen in children is more likely to worsen than improve over the years. This paper presents the probable cause of the condition, treatment and prevention of the problem and recommendations for the future.The deforming foot posture known as excessive pronation is familiar to Podiatric Medicine and to Medicine generally. Yet, in spite of this familiarity, only an insignificant number of the millions of children in our country receive the simple available help required to minimize the problem.The Podiatric profession has within its grasp the wherewithal to correct this situation, through education and counseling of parents, through cooperation with pediatricians and other professionals and by utilizing technological advances in children's footgear and orthotics. It is the intention of this paper to provide an overview of the literature and history associated with the problem of excessive pronation in children, as well as to suggest some simple techniques for improving this situation.Dr. Tax is an international renowned consultant to many Podiatric Hospital amon which is the Veterans Administration in New Jersey, New York College of Podiatric Medicine, Ohio College of Podiatric Medicine. He has written and lectured extensively on the subject of children and problems with their feet.     

Improving logistic regression on the imbalanced data by a novel penalized log-likelihood function

Logistic regression is estimated by maximizing the log-likelihood objective function formulated under the assumption of maximizing the overall accuracy. That does not apply to the imbalanced data. The resulting models tend to be biased towards the majority class (i.e. non-event), which can bring great loss in practice. One strategy for mitigating such bias is to penalize the misclassification costs of observations differently in the log-likelihood function. Existing solutions require either hard hyperparameter estimating or high computational complexity. We propose a novel penalized log-likelihood function by including penalty weights as decision variables for observations in the minority class (i.e. event) and learning them from data along with model coefficients. In the experiments, the proposed logistic regression model is compared with the existing ones on the statistics of area under receiver operating characteristics (ROC) curve from 10 public datasets and 16 simulated datasets, as well as the training time. A detailed analysis is conducted on an imbalanced credit dataset to examine the estimated probability distributions, additional performance measurements (i.e. type I error and type II error) and model coefficients. The results demonstrate that both the discrimination ability and computation efficiency of logistic regression models are improved using the proposed log-likelihood function as the learning objective.     

Cultural capital or relative risk aversion? Two mechanisms for educational inequality compared1

In this paper we empirically examined two explanatory mechanisms for educational inequality: cultural reproduction and relative risk aversion, using survey data taken from secondary school pupils in Amsterdam. Cultural reproduction theory seeks to explain class variations in schooling by cultural differences between social classes. Relative risk aversion theory argues that educational inequalities can be understood by between-class variation in the necessity of pursuing education at branching points in order to avoid downward mobility. We showed that class variations in early demonstrated ability are for a substantial part cultural: cultural capital - measured by parental involvement in highbrow culture - affected school performance at the primary and secondary level. However, relative risk aversion - operationalized by being concerned with downward mobility - strongly affects schooling ambitions, whereas cultural capital had no effect. Thus, we conclude that 'primary effects' of social origin on schooling outcomes are manifested through cultural capital and not through relative risk aversion (in addition to other potential sources of class variations such as genetics). Relative risk aversion, and not cultural capital, affects schooling ambitions, which is relevant for our understanding of secondary effects.     

Correlation in a Bayesian framework

The authors consider the correlation between two arbitrary functions of the data and a parameter when the parameter is regarded as a random variable with given prior distribution. They show how to compute such a correlation and use closed form expressions to assess the dependence between parameters and various classical or robust estimators thereof, as well as between p‐values and posterior probabilities of the null hypothesis in the one‐sided testing problem. Other applications involve the Dirichlet process and stationary Gaussian processes. Using this approach, the authors also derive a general nonparametric upper bound on Bayes risks.     

Examining the interplay of an organization's prior reputation,CEO's visibility,and immediate response to a crisis

In one of only a few crisis communication research studies taking a relational approach, examining the effects of a company's prior reputation in publics’ responses to a given crisis situation, Lyons and Cameron (2004) found that both reputation and response profoundly affected publics’ attitude and behavioral intentions toward an organization involved in a crisis situation, using hypothetical, fictitious organizations and crises. Using actual organizations and crises, our research team designed a 2 (reputation: good vs. bad) × 2 (crisis response: apologetic vs. defensive) × 2 (CEO visibility in immediate crisis response: visible vs. invisible) within-subjects experiment (N = 102) to examine the variances in stakeholders’ attitudes and behavioral intentions toward a company after being exposed to online video that delivered a corporate crisis response. Findings were counter-intuitive: a defensive response to a crisis is as acceptable to crisis stakeholders as an apologetic response if the CEO is visible (or audible) in the response and if the pre-crisis company-stakeholder reputation is positive. Good reputation, defensive crisis response and CEO visibility in immediate response to a crisis resulted in the best stakeholder attitudes and purchase intentions.     

Weighted simulated integrated conditional moment tests for parametric conditional distributions of stationary time series processes

In this article, we propose a weighted simulated integrated conditional moment (WSICM) test of the validity of parametric specifications of conditional distribution models for stationary time series data, by combining the weighted integrated conditional moment (ICM) test of Bierens (1984 Bierens, H. J. (1984). Model specification testing of time series regressions. Journal of Econometrics 26:323–353.[Crossref], [Web of Science ®] , [Google Scholar]) for time series regression models with the simulated ICM test of Bierens and Wang (2012 Bierens, H. J., Wang, L. (2012). Integrated conditional moment tests for parametric conditional distributions. Econometric Theory 28:328–362.[Crossref], [Web of Science ®] , [Google Scholar]) of conditional distribution models for cross-section data. To the best of our knowledge, no other consistent test for parametric conditional time series distributions has been proposed yet in the literature, despite consistency claims made by some authors.     

Income inequality and participation: A comparison of 24 European countries

Previous research suggests that when there is a high level of inequality, there is a low rate of participation. Two arguments are generally offered: First, inequality depresses participation because people from different status groups have fewer opportunities to share common goals. Second, people may participate more in civic and social life when they have more resources. However, until now, these explanations have not been separated empirically. Using EU-SILC data for 24 European countries, we analyze how income inequality is related to civic and social participation. Our results indicate that the main effects of inequality manifest via resources at the individual and societal level. However, independent of these resources, higher inequality is associated with lower civic participation. Furthermore, inequality magnifies the relationship between income and participation. This finding is in line with the view that inter-individual processes explain why inequality diminishes participation.