We consider a pushdown automaton as a word-rewriting system with labelled rules applied only in a prefix way. The notion of pushdown transition graph is then extended to the notion of prefix transition graph generated by a word-rewriting system and accessible from a given axiom. Such accessible prefix transition graphs are context-free graphs in the sense of Muller and Schupp (1985), and we sho...

Pentameric ligand-gated ion channels are an important family of membrane proteins and play key roles in physiological processes, including signal transduction at chemical synapses. Here, we study the conformational changes associated with the opening and closing of the channel pore. Based on recent crystal structures of two prokaryotic members of the family in open and closed states, respective...

The goal of this paper is to address whether and how the changing family sizes of cohorts born before and after the demographic transition are associated with increasing schooling in Brazil. Multivariate analyses of nationally representative data demonstrate that, although a higher proportion of adolescents born after the demographic transition live in smaller families, they also suffer a great...

Natural Family Planning ............................. 1 The Menstrual Cycle .................................. 4 Male Fertility ................................................ 6 Contraceptives ........................................... 9 Under the Microscope Staging the Menopausal Transition: TREMIN and STRAW.................................. 13 Of Interest ......................................

Amido rotation in the chromium(vi), d(0)-system NCr(NPr(i)2)2X is under investigation as a method for the parameterization of ligands for their donor properties toward high valent metals. In this study, two new series were prepared and studied based on chalcogenide ligands, X = EBu(t) and EPh and where E = O, S, Se, Te; the OPh and SPh compounds were previously reported. The ligand donor parame...

OBJECTIVE The objective was to provide a synthesis of the results of the research and discourse lines on main dimensions of patient-centered care in the context of chronic disease management in family medicine, building on Stewart et al.'s model. METHODS We developed search strategies for the Medline, Embase, and Cochrane databases, from 1980 to April 2009. All articles addressing patient-cen...

Introduction: Adolescence is a transition period from childhood to adulthood. Important patterns that can affect a person's life throughout his/her lifetime are formed during this period. Therefore, it is necessary to study the variables associated with behavioral patterns, especially the high-risk behaviors among adolescents. Methods: The purpose of this study was to investigate the relations...

MOTIVATION microRNAs (miRNAs) are known to play an essential role in the post-transcriptional gene regulation in plants and animals. Currently, several computational approaches have been developed with a shared aim to elucidate miRNA-mRNA regulatory relationships. Although these existing computational methods discover the statistical relationships, such as correlations and associations between ...

The impact of bolus ingestion and level of consciousness on swallowing apnea duration (SAD) in healthy term infants has not been adequately explored despite the likely contribution of swallowing apnea to upper airway protection against aspiration. SAD during wakefulness, sleep, and feeding (breast or bottle) of 10 term infants was measured 10 times from birth to 1 year of age. Nineteen thousand...

BACKGROUND Preparing adolescents for transition into adult care and supporting their acquisition of self-health care management skills is a critical determinant of their post-transition HIV care outcomes. However, there is a scarcity of research on effective transition strategies. This study explores factors associated with adolescent preparedness for transition into adult care in Cambodia. M...