A classification updating procedure motivated by high-content screening data

The current paradigm for the identification of candidate drugs within the pharmaceutical industry typically involves the use of high-throughput screens. High-content screening (HCS) is the term given to the process of using an imaging platform to screen large numbers of compounds for some desirable biological activity. Classification methods have important applications in HCS experiments, where they are used to predict which compounds have the potential to be developed into new drugs. In this paper, a new classification method is proposed for batches of compounds where the rule is updated sequentially using information from the classification of previous batches. This methodology accounts for the possibility that the training data are not a representative sample of the test data and that the underlying group distributions may change as new compounds are analysed. This technique is illustrated on an example data set using linear discriminant analysis, k-nearest neighbour and random forest classifiers. Random forests are shown to be superior to the other classifiers and are further improved by the additional updating algorithm in terms of an increase in the number of true positives as well as a decrease in the number of false positives.     

A robust principal component analysis

This work is concerned with robustness in Principal Component Analysis (PCA). The approach, which we adopt here, is to replace the criterion of least squares by another criterion based on a convex and sufficiently differentiable loss function ρ. Using this criterion we propose a robust estimate of the location vector and introduce an orthogonality with respect to (w.r.t.) ρ in order to define the different steps of a PCA. The influence functions of a vector mean and principal vectors are developed in order to provide method for obtaining a robust PCA. The practical procedure is based on an alternative-steps algorithm.     

Why Are Some Subsidiaries of Multinationals the Source of Novel Practices while Others Are Not? National,Corporate and Functional Influences

It has frequently been argued that multinational companies are moving towards network forms whereby subsidiaries share different practices with the rest of the company. This paper presents large‐scale empirical evidence concerning the extent to which subsidiaries input novel practices into the rest of the multinational. We investigate this in the field of human resources through analysis of a unique international data set in four host countries – Canada, Ireland, Spain and the UK – and address the question of how we can explain variation between subsidiaries in terms of whether they initiate the diffusion of practices to other subsidiaries. The data support the argument that multiple, rather than single, factor explanations are required to more effectively understand the factors promoting or retarding the diffusion of human resource practices within multinational companies. It emerges that national, corporate and functional contexts all matter. More specifically, actors at subsidiary level who seek to initiate diffusion appear to be differentially placed according to their national context, their place within corporate structures and the extent to which the human resource function is internationally networked.     

A new estimate of Ukrainian population losses during the crises of the 1930s and 1940s

Ukraine experienced two very acute demographic crises during the Soviet era: the 1933 famine and the Second World War. While different estimates of total losses have been produced previously, we have tried here to distinguish the specific impact of the crises on mortality from their impact on fertility and migration. Taking into account all existing sources of registered data and estimates, a painstaking reconstruction of annual demographic changes has been produced and complete annual life tables have been computed for the years 1926-59. Life expectancy at birth fell to a level as low as 10 years for females and 7 for males in 1933 and plateaued around 25 for females and 15 for males in the period 1941-44.     

Ethical Issues that arise in Bankruptcy

Bankruptcy is designed to give the debtor another chance after a financial failure, and it is often an option that is both more ethical and more efficient than liquidation. We address some basic issues, such as whether Chapter 11 bankruptcy itself is ethical and what elements help one to decide if a particular bankruptcy is ethical. There are many chances for unethical acts during bankruptcy, such as the ethics of a firm that files for Chapter 11 bankruptcy yet has sufficient assets to meet its financial obligations, or the often exorbitant fees that bankruptcy professionals are allowed as well as the apparent partiality demonstrated in some bankruptcy courts.     

L‘économie des Québécois francophones à la lumière de la socio-anthropologie*

After taking a summary look at the links that exist between anthropology and sociology, the author introduces what would seem at first glance to be a new discipline, that of socio-anthropology. Advances made in this new field of research stem from the implications behind the definition given to the object of study, and from the methods used. An economic sector controlled by French-speaking Quebecers serves as an illustration. Its examination draws on the hypothesis that family relationships are constituent of relationships in production, that is, of the economic structure. The author then posits that an interdisciplinary approach is essential in socio-anthropology. Après un rapide survol des liens entre l'anthropologie et la sociologie, cet article présente ce qui semble être, au premier abord, une nouvelle discipline: la socio-anthropologie. Les progrès de cette dernière résident notamment dans la teneur de la définition de l'objet et dans les méthodes adoptées pour l'étudier. L'examen de l'économie des francophones au Québec sert ici d'illustration. Il se réclame de l'hypothèse voulant que les rapports de parenté soient constitutifs des rapports de production, c'est-á-dire de la structure économique. La socio-anthropologie relève, au dire de l'auteur, d'une approche interdisciplinaire.     

Sexual inactivity among men who have sex with men living with hiv in europe

Objectives: Most people living with HIV stay sexually active, but some remain inactive. This study investigated prevalence and correlates of sexual inactivity among European HIV-positive men who have sex with men (MSM). Methods: An anonymous sexual health questionnaire was distributed in 17 HIV outpatient clinics throughout Europe. Ninety-seven (11.6%) of 838 respondents reported absence of sexual activity. Results: Multivariable regression analysis identified older age, relationship status, and less satisfaction with general health and sexual desire as being associated with sexual inactivity. Conclusions: Prevalence of sexual inactivity has declined since the introduction of antiretroviral therapy to levels similar to those of HIV-negative MSM, suggesting a tendency toward normalization of HIV-positive MSM's sex lives.