Sex pheromones of moths

It is well established that male moths are attracted to the females by physiologically highly active substances (pheromones) secreted by the latter. Research has revealed the chemical nature of many of these pheromones and much attention has been directed to putting them to practical use, with other methods, for the field control of pests.     

Bessel functions and buckling of the uniform column under combined action due to its own weight and an axial load

If one considers the set of vertical and horizontal loads applied to the column with constant inertia, the classical homogeneous Euler differential equation of the third-order expressing the behavior of the column under its own weight uniformly distributed along the vertical axis is transformed into a non-homogeneous equation by the concept of fictitious length. A new operator attached to Bessel functions is introduced, and the general solution to the non- homogeneous equation is obtained, leading to a formula expressing the critical load of the bar. New formulae are also proposed for the critical load of the bar under its own weight acting alone, and under different support conditions.     

LATENT CLASS ANALYSIS OF CONDUCT PROBLEMS OF ELEMENTARY STUDENTS RECEIVING SPECIAL EDUCATION SERVICES

Students with conduct problems (CPs) may present heterogeneity in terms of behavioral manifestations and service needs. Previous studies using Latent Class Analysis (LCA) to capture this heterogeneity have been conducted mostly with community samples and have often applied a narrow definition of CP. Considering this context, this study investigated CP subgroups among elementary students with CP receiving special education services. LCA was conducted on 10 CP indices for 297 6–9 year old children. Latent CP subgroups were compared with 201 controls without CP. LCA suggests a three‐class solution based on severity of CP and context/informant reports (home/parent, school/teacher). Multinomial logistic regressions indicated that all CP subgroups differed from the control group on social competence and surgency/extraversion temperament scale in the expected direction but varied on specific personal, family, or school correlates. Interventions aimed at reducing CP should consider differences in CP subtype and in correlated risk factors.     

Improving Person-Fit Assessment by Correcting the Ability Estimate and Its Reference Distribution

The standardized log-likelihood of a response vector (l_z) is a popular IRT-based person-fit test statistic for identifying model-misfitting response patterns. Traditional use of l_z is overly conservative in detecting aberrance due to its incorrect assumption regarding its theoretical null distribution. This study proposes a method for improving the accuracy of person-fit analysis using l_z which takes into account test unreliability when estimating the ability and constructs the distribution for each l_z through resampling methods. The Type I error and power (or detection rate) of the proposed method were examined at different test lengths, ability levels, and nominal α levels along with other methods, and power to detect three types of aberrance—cheating, lack of motivation, and speeding—was considered. Results indicate that the proposed method is a viable and promising approach. It has Type I error rates close to the nominal value for most ability levels and reasonably good power.     

Bridging Courses in Chemistry and Physics for Engineering Students

Throughout the 1980s there has been a remarkable rise in the retention rate of Australian students in secondary education. Although the absolute numbers of students undertaking the traditional upper secondary school preparatory subjects for Engineering courses has been increasing, their proportion as a percentage of the whole Year 12 group has simultaneously been decreasing.

In the face of this situation, the Faculty of Engineering at Monash decided in 1989 to ask the Faculty of Education to offer special bridging courses in chemistry and physics to students who had the appropriate high entry scores, but who had not studied either one or the other of these subjects during their Year 12 program.

After an initial period of data collection involving researching the chemistry and physics courses, two intensive special bridging courses to be taken over one semester were designed to meet the needs of these students. The first four years of the program have produced very encouraging results. The paper describes the rationale behind the design of these courses and the range of teaching and learning strategies that have been employed. It includes a discussion of some of the conditions that are believed to be necessary to ensure the success of such a bold educational experiment.     

An analysis of research studies in which “homemade” achievement instruments were utilized

This article will have as its focus a problem described by Anderson, namely, the quality of the construction and reporting of research that contains “homemade” achievement tests. The current status of homemade achievement tests was examined in this study. Research reports in two science education journals were analyzed, using Anderson's eight categories of information that a high quality research report should include. The journals examined were Journal of Research in Science Teaching and Science Education from January 1975 to January 1980. The findings indicate that reliability estimates and the procedures for selecting test items were mentioned more frequently in the science education journals than in Anderson's study. However, there was little or no improvement in describing the relation of test items to instruction. These findings should be of interest both to researchers who are utilizing “homemade” achievement tests in their studies and to journal panels who are reviewing studies for publication.     

Pädagogisierung und Systembildung

Eine M?glichkeit, das Verh?ltnis von P?dagogik und Gesellschaft zu beschreiben, scheint im Begriff P?dagogisierung zu liegen. In der jüngeren Diskussion lassen sich zwei Konzeptualisierungen dieses Begriffs unterscheiden. P?dagogisierung kann erstens als Transformation sozialer Probleme in p?dagogische Probleme gedeutet werden. Hier wird unterstellt, dass soziale Probleme durch die Einwirkung auf Menschen mit den Mitteln institutionalisierter Erziehung und Bildung zu bearbeiten seien. P?dagogisierung l?sst sich zweitens als Ausdifferenzierung eines symbolisch-kommunikativen Systems innerhalb der Gesellschaft beschreiben. Diese Vorstellung referiert auf die Abl?sung des P?dagogischen von den klassischen Erziehungsinstitutionen. Vor dem Hintergrund dieser Unterscheidung rückt der vorliegende Beitrag in drei Fallstudien den gesellschaftlichen Umgang mit dem so genannten Dritte-Welt-Problem in der Bundesrepublik in das Blickfeld. Die dabei zu beobachtenden Bezugnahmen auf P?dagogik durch die Dritte-Welt-Protestbewegung, das zust?ndige Bundesministerium und Organisationen des Erziehungssystems werden als je unterschiedliche P?dagogisierungsf?lle rekonstruiert. Deren Hybridit?t, d.h. sowohl Eingrenzung wie Entgrenzung, sowohl Bezug des P?dagogischen auf wie auch Abl?sung des P?dagogischen vom institutionalisierten Erziehungssystem, legt es theoretisch nahe, so die These, P?dagogisierungsprozesse in den Zusammenhang von Formbildungen des P?dagogischen einzuordnen.