Gender-Typed and Gender-Segregated Play Among Tanzanian Hadza and Congolese BaYaka Hunter-Gatherer Children and Adolescents

Few data exist on gender-typed and gender-segregated play in hunter-gatherer societies, despite their unique demographic and cultural features which may influence children’s gendered play. Using naturalistic observations of Hadza (N = 46, 41% female) and BaYaka (N = 65, 48% female) hunter-gatherer 3- to 18-year-olds from Tanzania and the Republic of Congo, we showed that access to playmates was negatively associated with playing in mixed-gender groups. Young boys did not engage in more rough-and-tumble play than girls, but adolescent boys participated in this type of play more than adolescent girls. Children were also more likely to participate in work-themed play which conformed to gender norms within their society. Findings are discussed within the context of gendered division of labor, child autonomy, and demography.     

Reading Comprehension of Dutch Deaf Children

In this study, the reading comprehension of deaf children and adolescents in the Netherlands is examined along with their word identification. The reading comprehension of 464 deaf students and the word identification of 504 deaf students between 6 and 20 years of age was examined. The results show the reading comprehension scores of deaf children to be far below the scores of hearing children. On average, the deaf subjects scored at a level equivalent to a hearing child in the first grade. The word identification scores of the deaf children, however, were almost equivalent to the scores of hearing children. Although reading comprehension and word identification appear to be related, this relation does not completely explain the comprehension difficulties encountered by deaf children. Additional factors are required to explain deaf children’s difficulties with reading comprehension.     

Relative preferences for various bivalued ratio schedules

Widely cited experiments on optimal foraging have used bivalued distributions as representing environmental stochasticity, characterizing these in terms of their arithmetic means. In contrast, research on free-operant choice has established that organisms prefer variable patterns of food delivery, relative to fixed patterns with the same mean values. To explore such departures from linear averaging, specifically with respect to bivalued alternatives, pigeons were given choices between a fixed-ratio (FR) schedule of food delivery that required 15, 30, or 60 responses and bivalued variable-ratio schedules with an arithmetic mean of 60,5 or 60, A bivalued schedule of 1 and 120 was preferred almost exclusively over each of the FR values. With a bivalued schedule of 15 and 105, there was a shift of preference, most notably in the FR-15 condition, but in no case was linear averaging a good predictor of the birds’ choices. Geometric averaging fared better, but even this failed to represent the apparent salience of the minimum value of the bivalued schedule in some conditions.     

Students in Australian Catholic and Independent Schools Have More Positive Learning Environments: Evidence From the 2012 PISA Study

Critics of Catholic and independent (nongovernment) schools in Australia contend that the higher levels of performance of students in nongovernment schools can be dismissed as simply a function of student- and especially school-level socioeconomic status (school-SES). A recent article extends this critique to school-sector differences in students’ evaluations of their teachers and schools, arguing that the observable school-sector differences are because of differences in school-SES, not because of school-sector differences in their teachers and schools. In response, this article reviews these arguments and focuses on school-sector differences in students’ evaluations of their teachers and schools using the Organization for Economic Development and Cooperation’s (OECD) measures in the PISA 2009 study. On eight of the 10 attitudinal measures, students attending Catholic and independent schools have more positive evaluations and these school-sector differences survive controls for students’ SES, their overall level of achievement and school-SES, which has no substantive influence. Although the effect sizes are generally small (0.06–0.26) their combined influence means that nongovernment school students enjoy superior learning environments which is likely to contribute to their generally higher levels of academic performance in senior secondary school.     

On optimal location and management of a new industrial plant: Numerical simulation and control

Within the framework of numerical modelling and multi-objective control of partial differential equations, in this work we deal with the problem of determining the optimal location of a new industrial plant. We take into account both economic and ecological objectives, and we look not only for the optimal location of the plant but also for the optimal management of its emissions rate. In order to do this, we introduce a mathematical model (a system of nonlinear parabolic partial differential equations) for the numerical simulation of air pollution. Based on this model, we formulate the problem in the field of multi-objective optimal control from a cooperative viewpoint, recalling the standard concept of Pareto-optimal solution, and pointing out the usefulness of Pareto-optimal frontier in the decision making process. Finally, a numerical algorithm – based on a characteristics/Galerkin discretization of the adjoint model – is proposed, and some numerical results for a hypothetical situation in the region of Galicia (NW Spain) are presented.