On the Complexity of Constructing Evolutionary Trees

In this paper we study a few important tree optimization problems with applications to computational biology. These problems ask for trees that are consistent with an as large part of the given data as possible. We show that the maximum homeomorphic agreement subtree problem cannot be approximated within a factor of , where N is the input size, for any 0 in polynomial time unless P = NP, even if all the given trees are of height 2. On the other hand, we present an O(N log N)-time heuristic for the restriction of this problem to instances with O(1) trees of height O(1) yielding solutions within a constant factor of the optimum. We prove that the maximum inferred consensus tree problem is NP-complete, and provide a simple, fast heuristic for it yielding solutions within one third of the optimum. We also present a more specialized polynomial-time heuristic for the maximum inferred local consensus tree problem.     

Effects of suicidal behavior on a psychiatric unit nursing team

1. Suicide of a psychiatric inpatient can have significant, although diverse, effects on the emotions and behavior of both individual nurses and team functioning. 2. The majority of participants in this study felt there was a need for formal debriefing or counseling for themselves and their colleagues after a critical incident, although there was less consensus about the timing and structure of such an intervention. 3. This research highlights the need for advanced training of critical incident stress management team members and for flexibility in the application of critical incident stress management techniques.     

Perturbation Analysis of Indices of Lifespan Variability

A number of indices exist to calculate lifespan variation, each with different underlying properties. Here, we present new formulae for the response of seven of these indices to changes in the underlying mortality schedule (life disparity, Gini coefficient, standard deviation, variance, Theil’s index, mean logarithmic deviation, and interquartile range). We derive each of these indices from an absorbing Markov chain formulation of the life table, and use matrix calculus to obtain the sensitivity and the elasticity (i.e., the proportional sensitivity) to changes in age-specific mortality. Using empirical French and Russian male data, we compare the underlying sensitivities to mortality change under different mortality regimes to determine the conditions under which the indices might differ in their conclusions about the magnitude of lifespan variation. Finally, we demonstrate how the sensitivities can be used to decompose temporal changes in the indices into contributions of age-specific mortality changes. The result is an easily computable method for calculating the properties of this important class of longevity indices.     

A Note on Exponentially Smoothed Seasonal Differences

Filtering economic time series can be justified if variations within a certain frequency interval are relevant for the problem at hand. It is shown here that exponential smoothing of seasonal differences provides a simple means of damping short oscillations, including seasonal ones.     

Agriculture,communities, and new social movements: East European ruralities in the process of restructuring

This paper examines the usefulness of the new social movements (NSMs) paradigm in the changing context of East European post-communist societies and their agricultural systems and rural communities. Starting with statements formulated in Western sociology in the context of Western democratic societies about NSMs as a protest against modernity, the paper analyses the role of such movements in the still modernizing Eastern European reality. The first part of the paper briefly examines some basic elements of the NSMs paradigm in European and American social science. The goal of this section is not only to identify the basic characteristics of NSMs, but also to identify the typical frames used by them. The second part of the paper focuses on the presence of NSMs in the communist era. Drawing on the idea of NSMs as indicators of a ‘post-materialist shift’ as well as of ‘anti-establishment’ and ‘pro-participatory democracy’, the paper examines the frames of democratic opposition in Eastern Europe before 1989. The final part of the paper considers several selected examples from Poland, Hungary, and the Czech Republic to explore the role of NSMs in the process of shaping new ruralities during the post-communist transformation.     

Psychometric Properties of the Differentiation of Self Inventory‐Revised in Turkish Adults

The purpose of the current study was to examine the validity and reliability of (Journal of Marital and Family Therapy 2003, 29, 209) Differentiation of Self Inventory‐Revised (DSI‐R; Skowron & Schmit, 2003) in Turkish adults. The DSI‐R was translated, independently back‐translated, and revised. Two independent samples of adults over the age of 25 were used. The original 46‐item DSI‐R was not supported by the data derived from Sample 1 (n = 221). However, a revised 20‐item, four‐factor model fit the data well. This 20‐item model was subsequently cross‐validated with a second sample of Turkish adults (n = 187). Scale scores showed adequate internal consistency, 5‐week test–retest reliability, and satisfactory convergent and criterion‐related validity. It was concluded that Turkish DSI‐R (DSI‐T) is a valid and reliable measure to assess an individual's differentiation level. In light of the findings, implications for the use of the DSI‐T and ideas for future research are discussed.