Machine Learning in Automated Text Categorization

The automated categorization (or classification) of texts into predefined categories has witnessed a booming interest in the last ten years, due to the increased availability of documents in digital form and the ensuing need to organize them. In the research community the dominant approach to this problem is based on machine learning techniques: a general inductive process automatically builds a classifier by learning, from a set of preclassified documents, the characteristics of the categories. The advantages of this approach over the knowledge engineering approach (consisting in the manual definition of a classifier by domain experts) are a very good effectiveness, considerable savings in terms of expert manpower, and straightforward portability to different domains. This survey discusses the main approaches to text categorization that fall within the machine learning paradigm. We will discuss in detail issues pertaining to three different problems, namely document representation, classifier construction, and classifier evaluation.Comment: Accepted for publication on ACM Computing Survey

Active Brownian Particles. From Individual to Collective Stochastic Dynamics

We review theoretical models of individual motility as well as collective dynamics and pattern formation of active particles. We focus on simple models of active dynamics with a particular emphasis on nonlinear and stochastic dynamics of such self-propelled entities in the framework of statistical mechanics. Examples of such active units in complex physico-chemical and biological systems are chemically powered nano-rods, localized patterns in reaction-diffusion system, motile cells or macroscopic animals. Based on the description of individual motion of point-like active particles by stochastic differential equations, we discuss different velocity-dependent friction functions, the impact of various types of fluctuations and calculate characteristic observables such as stationary velocity distributions or diffusion coefficients. Finally, we consider not only the free and confined individual active dynamics but also different types of interaction between active particles. The resulting collective dynamical behavior of large assemblies and aggregates of active units is discussed and an overview over some recent results on spatiotemporal pattern formation in such systems is given.Comment: 161 pages, Review, Eur Phys J Special-Topics, accepte

The Three-Component Model of Occupational Commitment: A Comparative Study of Chinese and British Accountants

The authors find some support for the cross-cultural validity of the Meyer, Allen, and Smith (1993) three-component model of occupational commitment in samples of Chinese and British accountants. Normative and affective commitments are higher in the Chinese sample, and continuance commitment is higher in the British sample. There is some support for hypotheses on the consequences of the components of occupational commitment (occupational withdrawal cognitions and the intention to participate in professional activities). However, contrary to the hypotheses, the authors' analysis suggests that there are no significant differences in these relationships between the two samples. The authors find a significant interaction between affective and continuance commitment in the analysis of occupational withdrawal cognitions, such that the relationship between each of these components and withdrawal cognitions is stronger where commitment on the other component is low

Medical decisional capacity among children with HIV

Medical decisional capacity (DC) refers to the ability to understand, appreciate, and make meaningful decisions about one\u27s health. This is an important construct for children living with HIV whose involvement in their medical care has important implications for disease management. In this study, we assessed the relationship among DC, developmental stage, intellectual ability, and social-emotional functioning of children with and without HIV infection (n_50). We hypothesized a positive correlation between variables, but did not expect to find a difference in DC between groups. Results provided partial support for our hypotheses. There was a positive relationship between developmental stage and understanding, which is but one dimension of DC. Children with HIV infection obtained significantly lower scores on measures of intellectual and adaptive functioning, but there was no significant difference in DC between groups. Findings suggest that children living with HIV have the capacity to meaningfully participate in their healthcare despite lower intellectual and adaptive functioning

End-of-life decision making in pediatrics: literature review on children's and adolescents' participation

Background: Pediatric guidelines recommend that children and adolescents participate in a developmentally appropriate way in end-of-life decision making. Shared decision making in pediatrics is unique because of the triadic relationship of patient, parents, and physician. The involvement of the patient may vary on a continuum from no involvement to being the sole decision maker. However, the effects of child participation have not been thoroughly studied. The aim of this literature review is to identify studies on end-of-life decision making in pediatrics to explore patient participation and to assess the effects of such participation. Methods: Five databases - PubMed, PsycInfo, Medline, CINAHL, and Sociological Abstract - were searched for empirical studies on end-of-life decision making in pediatrics. Selected articles fulfilling the criteria were assessed for type of decision, participants’ characteristics, reports on participation of the minor patient, and outcome. Results: Fifty-seven articles on end-of-life decision making in pediatrics were identified. The majority of papers (n = 43, 75%) investigated parents’ and clinicians’ perspectives, while only 14 articles (25%) included perspectives of children and adolescents. Twenty-two articles (39%) reported some details on various forms of children's participation (e.g., receive information, plan care details, consulted before or after a decision was made). Positive (e.g., respect for patient's preferences) as well as negative (e.g., conflict due to diverging opinions) effects of children's participation in end-of-life decision making were reported. Conclusions: This systematic review highlights the need for research to identify factors that contribute to a favorable participation of minors in decision making processes as well as strategies to solve possible conflicts. More research should take into account the dynamics in the triadic process of decision making and emphasize children and adolescents’ perspectives. A better understanding of how to meaningfully involve children and adolescents in end-of-life decision making could facilitate the practice of patient participation in pediatrics