Modelling two way contingency tables with recursive logits and odds ratios

In this work a new type of logits and odds ratios, which includes as special cases the continuation and the reverse-continuation logits and odds ratios, are defined. We prove that these logits and odds ratios define a parameterization of the joint probabilities of a two way contingency table. The problem of testing equality and inequality constraints on these logits and odds ratios is examined with particular regard to two new hypotheses of monotone dependence. Work partially supported by a MIUR2004 grant. Preliminary findings have been presented at SIS (Società Italiana di Statistica) Annual Meeting, Torino, 2006.     

Predicting Severity of Foreign Body Injuries in Children in Upper Airways: An Approach Based on Regression Trees

The entry of a small item into the upper airways is one of the leading causes of injuries in children up to 14 years old. The aim of this study is to characterize types of objects causing choking along with the features of the children involved in the accident and compare results with current standards. The European Survey on Foreign Bodies Injuries Study (ESFBI) collected data on foreign body injuries from 19 European countries. The data from ESFBI were selected according to the ICD-9-CM codes 933 (foreign body in the pharynx and larynx) and 934 (foreign body in the trachea, bronchi, and lungs). Both a classification tree and a linear discriminant analysis (LDA) have been set up to predict the probability that an injured child experiences a hospitalization. The classification tree provides flowchart-type decision rules and allows for analyzing the impact of the item features, the children characteristics, and the circumstances of the accidents on the severity of the foreign body injuries. Results showed that children younger than 3.5 who are involved in an accident have a high probability to experience a hospitalization.     

The policies of unemployment protection in Europe

The abundant literature on welfare state policies, regimes or ‘worlds’ has been only limitedly interested in unemployment protection, and even less in youth unemployment protection. What is clearly lacking in the literature is an updated analysis of the most recent policies developed in European countries targeting youth. This mini‐symposium aims to fill in this gap by presenting findings from an EU‐funded research project entitled ‘Youth, Unemployment and Exclusion in Europe: A Multidimensional Approach to Understanding the Conditions and Prospects for Social and Political Integration of Young Unemployed’ (YOUNEX). The main aim of the research endeavour was to develop theory and contribute to empirical knowledge concerning the social and political exclusion of unemployed youth in Europe.     

Public Health Institutions,Clinical Research and Protection System of Patients’ Rights: An Impact Evaluation of Public Policy

Public health institutions are involved in human experimentations, which is a specific phase of pharmaceutical industry’s production process. These medical centers collect clinical evidence about experimental treatments and, at the same time, they have to guarantee patients’ safety through appropriate Institutional Review Boards. Taking human experimentation into account, this work aims at estimating a public policy designed to reduce transaction costs that are related to the protection system of patients’ rights, with both a normative and positive approach. On the one hand, considering a sample of European countries as counterfactual, an empirical analysis is performed in order to estimate the impact of a national law aimed at harmonizing the procedure to obtain opinions on clinical trials. On the other hand, an alternative law, which might be able to favor the exchange between pharmaceutical companies and patients, is proposed.     

Friendships in late life: A rural-urban comparison

This study examines the friendship patterns of older adults living in rural and urban areas. The sample consisted of 132 urban adults and 126 rural adults, 65 years of age and older. Respondents were randomly selected and interviewed in their own homes. While both groups were involved in joint social activities and helping behaviors with their friends, there was a distinction in the type of involvement according to geographical location.Karen Roberto is Assistant Professor and Coordinator of the Gerontology Program at the University of Northern Colorado. Her current research interests include women's health issues in aging and older people's involvement with informal support networks. Dr. Roberto holds a Ph.D. in Human Development from Texas Tech University.Jean Pearson Scott is Associate Professor in the Department of Human Development and Family Studies at Texas Tech University. Dr. Scott earned her Ph.D. from the University of North Carolina at Greensboro and is currently conducting research on Alzheimers Disease in the family and the rural elderly.This is a revised version of a paper presented at the Families and Close Relationships: Individuals in Social Interaction Conference, Lubbock, TX, February, 1982.This study was supported by a grant from AARP Andrus Foundation and the Institute for University Research, College of Home Economics, Texas Tech University, Lubbock, Texas 79409.     

BULIMIA: THE TRANSGENERATIONAL VIEW*

Within families presenting with bulimia, there exist interactional patterns that can be said to enable, and perpetuate, the binge-eating and purging symptoms of the identified patient. A transgenerational treatment method is proposed, which not only intervenes in ongoing dysfunctional patterns, but also provides a frame for creating a therapeutic metaphor (“legacy”) to direct the therapy. Rationale and stages of the treatment process are outlined, and a case example is given to illustrate use of the transgenerational frame.     

Partial and inverse autocorrelations in portmanteau-type tests for time series

We present a decomposition of the correlation coefficient between x_t and x_t?k into three terms that include the partial and inverse autocorrelations. The first term accounts for the portion of the autocorrelation that is explained by the inner variables {x_t?1 , x_t?2 , …, x _{t? k+1}}, the second one measures the portion explained by the outer variables {x _t+1, x _t+2, } ∪ {x _t?k?1, x _t?k?2,…} and the third term measures the correlation between x _t and x_t?k given all other variables. These terms, squared and summed, can form the basis of three portmanteau-type tests that are able to detect both deviation from white noise and lack of fit of an entertained model. Quantiles of their asymptotic sample distributions are complicated to derive at an adequate level of accuracy, so they are approximated using the Monte Carlo method. A simulation experiment is carried out to investigate significance levels and power of each test, and compare them to the portmanteau test.     

A new mixture model on the simplex

This paper is meant to introduce a significant extension of the flexible Dirichlet (FD) distribution, which is a quite tractable special mixture model for compositional data, i.e. data representing vectors of proportions of a whole. The FD model displays several theoretical properties which make it suitable for inference, and fairly easy to handle from a computational viewpoint. However, the rigid type of mixture structure implied by the FD makes it unsuitable to describe many compositional datasets. Furthermore, the FD only allows for negative correlations. The new extended model, by considerably relaxing the strict constraints among clusters entailed by the FD, allows for a more general dependence structure (including positive correlations) and greatly expands its applicative potential. At the same time, it retains, to a large extent, its good properties. EM-type estimation procedures can be developed for this more complex model, including ad hoc reliable initialization methods, which permit to keep the computational issues at a rather uncomplicated level. Accurate evaluation of standard error estimates can be provided as well.     

Soil organic carbon stock in different urban land uses: high stock evidence in urban parks

Urban Ecosystems - Urban areas are major producers of atmospheric CO2 emissions, but at the same time they can offset some of the associated C losses by retaining stable organic carbon in their...     

Size does matter: Passive sampling in urban parks of a regional bat assemblage

Urban Ecosystems - We studied the occurrence of bats in urban parks in the city of Madrid (Spain), and the resulting patterns were compared with bat occurrence in the surrounding region. In this...