An Age Dependent Epidemic Model*

The model presented here describes the spread of an infection in a population by keeping track of the chronological ages of the participants as well as their “class ages” (i.e. the length of time since entering their present state). The reasoning behind this model is similar to that used in the equation of age dependent population growth.     

Book reviews

International Review of Education -     

Indian plate paleogeography,subduction and horizontal underthrusting below Tibet: paradoxes,controversies and opportunities

The India–Asia collision zone is the archetype to calibrate geological responses to continent–continent collision, but hosts a paradox: there is no orogen-wide geological record of oceanic subduction after initial collision around 60–55 Ma, yet thousands of kilometers of post-collisional subduction occurred before the arrival of unsubductable continental lithosphere that currently horizontally underlies Tibet. Kinematically restoring incipient horizontal underthrusting accurately predicts geologically estimated diachronous slab break-off, unlocking the Miocene of Himalaya–Tibet as a natural laboratory for unsubductable lithosphere convergence. Additionally, three endmember paleogeographic scenarios exist with different predictions for the nature of post-collisional subducted lithosphere but each is defended and challenged based on similar data types. This paper attempts at breaking through this impasse by identifying how the three paleogeographic scenarios each challenge paradigms in geodynamics, orogenesis, magmatism or paleogeographic reconstruction and identify opportunities for methodological advances in paleomagnetism, sediment provenance analysis, and seismology to conclusively constrain Greater Indian paleogeography.     

Emerging analytical methods to characterize zeolite-based materials

Zeolites and zeolitic materials are, through their use in numerous conventional and sustainable applications, very important to our daily lives, including to foster the necessary transition to a more circular society. The characterization of zeolite-based materials has a tremendous history and a great number of applications and properties of these materials have been discovered in the past decades. This review focuses on recently developed novel as well as more conventional techniques applied with the aim of better understanding zeolite-based materials. Recently explored analytical methods, e.g. atom probe tomography, scanning transmission X-ray microscopy, confocal fluorescence microscopy and photo-induced force microscopy, are discussed on their important contributions to the better understanding of zeolites as they mainly focus on the micro- to nanoscale chemical imaging and the revelation of structure–composition–performance relationships. Some other techniques have a long and established history, e.g. nuclear magnetic resonance, infrared, neutron scattering, electron microscopy and X-ray diffraction techniques, and have gone through increasing developments allowing the techniques to discover new and important features in zeolite-based materials. Additional to the increasing application of these methods, multiple techniques are nowadays used to study zeolites under working conditions (i.e. the in situ/operando mode of analysis) providing new insights in reaction and deactivation mechanisms.     

Marriage and the Parenting Alliance: Longitudinal Prediction of Change in Parenting Perceptions and Behaviors

The study evaluates how marriage and the parenting alliance affect parenting experiences over time. Couples ( N = 79) with school-age children who have mental retardation completed self-report and observational measures of marriage, the parenting alliance, and parenting attitudes and behaviors at 2 periods, 18–24 months apart. Longitudinal structural equation modeling demonstrated significant effects of marital quality on changes over time in self-reports of perceived parenting competence for both the mothers and the fathers, and in observed negative mother-child interactions. Also, in all cases, the parenting alliance mediated the effects of marriage on parenting experiences. There was little evidence of reciprocal causation in which parenting variables predicted change in the quality of marriage and the parenting alliance. Interactions involving child age suggested that teenagers as opposed to younger children were more reactive to negative features of their parents' marital functioning and parenting alliance. Implications are discussed regarding stable but negative marital functioning and regarding possible differences in mothers' and fathers' parenting in the context of marital distress.     

Attachment style and loneliness in adolescence

Possible associations between parent-child interactions and adolescent well-being have been explored from a number of theoretical perspectives. In the present study, attachment theory was used as a general theoretical framework to study these associations with attention being concentrated on one particular aspect of adolescent well-being, i.e., loneliness and attitudes towards being alone. Measures of adolescent attachment style (based on ratings of both normal family scenes and stressful separation situations) and a multidimensional measure of loneliness were administered to two samples of Belgian (Dutch-speaking) adolescents aged 15 to 18 (n=200 and n=357, respectively). Subjects were classified into four attachment groups: Secure, Dependent, Anxious-Ambivalent and Avoidant. Results indicated that Securely attached adolescents experienced lower levels of parent-related loneliness and this effect extended to loneliness in the relationships with peers. Aversion to being alone was experienced more strongly among Dependently attached adolescents. Finally, adolescents who evidenced Avoidant or Anxious-Ambivalent attachment felt more positive about being on their own. Implications of these findings for attachment theory are discussed and problems associated with the four-category model of attachment as used in the present study are outlined.     

An interview study of college freshmens’ beliefs about their academic motivation

An important aspect of metacognition, one potentially affecting much of students’ academic efforts, was tapped in this study. College students’ beliefs about their academic motivation were elicited systematically using ethnographic interviewing. We reasoned that students are very conscious of their decisionmaking regarding academics, and thus, they would be able to report on many of the factors affecting their academic motivation. In general, the students reported that many factors affect their academic motivation, specifically, many more factors than have been considered in previous theoretical analyses of academic motivation, with students perceiving that interactions between motivational factors often are critically determinative of academic efforts and achievement.     

The Shift from Teaching to Learning: How Well Designed for the Shift are University‐level History Teacher Training Programmes?

The author, the President of EUROCLIO, a major association of European history teachers, considers the present state of history teacher preparation in the universities of Europe. Her primary complaint is that university programmes that are intended primarily for the training and preparation of future historians may neglect the needs of students planning to teach history in middle or in secondary schools. Typical university undergraduate history programmes tend to be overly academic, failing to provide enough in the way of pedagogical training. Thus the author recommends a strong dose of pedagogical methods courses as well as practical training for future history teachers. Other European organizations, particularly the Council of Europe and the European Union, are taking an interest in the ways in which history is being taught in the schools of their member states. The article ends with a survey of some recent conferences sponsored by these two organizations as well as by EUROCLIO on pedagogical and topical aspects of history teaching.     

Phase-based information retrieval

In this article we describe a retrieval schema which goes beyond the classical information retrieval keyword hypothesis and takes into account also linguistic variation. Guided by the failures and successes of other state-of-the-art approaches, as well as our own experience with the Irena system, our approach is based on phrases and incorporates linguistic resources and processors. In this respect, we introduce the phrase retrieval hypothesis to replace the keyword retrieval hypothesis. We suggest a representation of phrases suitable for indexing, and an architecture for such a retrieval system. Syntactical normalization is introduced to improve retrieval effectiveness. Morphological and lexico-semantical normalizations are adjusted to fit in this model.