Using genetic markers in unpedigreed populations to detect a heritable trait

Before a breeder invests selection pressure on a trait of interest, it needs to be established whether that trait is actually heritable. Some traits may not have been measured widely in pedigreed populations, for example, a disease or deformity may become more prevalent than previously, but is still relatively rare. One approach to detect inheritance would be to screen a commercial population to obtain a sample of "affecteds" (the test group) and to also obtain a random control group. These indi- viduals are then genotyped with a set of genetic markers and the relationships between individuals within each group estimated. If the relatedness is higher in the test group than in the control group, this provides initial evidence for the trait being heritable. A power simulation shows that this approach is feasible with moderate resources.     

Use of stochastic simulations to investigate the power and design of a whole genome association study using single nucleotide polymorphism arrays in farm animals

This paper presents a quick, easy to implement and versatile way of using stochastic simulations to investigate the power and design of using single nucleotide polymorphism (SNP) arrays for genome-wide association studies in farm animals. It illustrates the methodology by discussing a small example where 6 experimental designs are considered to analyse the same resource consisting of 6006 animals with pedigree and phenotypic records: (1) genotyping the 30 most widely used sires in the population and all of their progeny (515 animals in total), (2) genotyping the 100 most widely used sires in the population and all of their progeny (1102 animals in total), genotyping respectively (3) 515 and (4) 1102 animals selected randomly or genotyping respectively (5) 515 and (6) 1102 animals from the tails of the phenotypic distribution. Given the resource at hand, designs where the extreme animals are genotyped perform the best, followed by designs selecting animals at random. Designs where sires and their progeny are genotyped perform the worst, as even genotyping the 100 most widely used sires and their progeny is not as powerful of genotyping 515 extreme animals.     

The struggle for legitimacy: language provision in two ‘residual’ comprehensive high schools in Australia

Despite the contemporary policy rhetoric of global citizenry and the importance of languages and intercultural capabilities, language learning in Australian schools struggles for recognition and support. The curriculum marginalisation of languages, however, is uneven, affecting some school sectors more than others. In this article, we examine the provision of languages in two government comprehensive high schools, both low socio-economic status, located in urban areas in New South Wales, Australia’s largest state. They are termed ‘residual’ high schools because they cater for the students remaining in the local schools while others attend either private or selective government high schools. We provide a qualitative picture of language provision in these two schools from the perspectives of key stakeholders – school principals, teachers, students and parents. We also draw on observational data of language classes. The aim is to provide, within a largely social class framework, an understanding of the state of language provision in these schools. We argue that currently students in these schools are experiencing unequal access to the linguistic and cultural capital associated with language learning relative to students in more privileged communities and schools.     

A pedagogy of larger concerns used as a lens to reflect on the design of student learning experiences

ABSTRACT

Although engineering educational endeavours are often described with regard to how well they prepare students to meet national or global engineering concerns, the purpose of this paper is to show how those efforts can also serve the larger educational goals of the educators themselves as they develop learning experiences for their students. This paper describes the reflections of four engineering educators who used a research-based ‘Pedagogy of Larger Concerns’ (PLC) as a conceptual lens for examining important aspects of their courses. A PLC is a set of teaching conceptions that was identified in a study exploring the thinking of outstanding professors in order to improve our understanding of the basis of their effectiveness.     

Impulsiveness in pigeons living in the experimental chamber

Pigeons’ choices between larger, more delayed and smaller, less delayed reinforcers were examined while the pigeons lived in the experimental chamber for 23-h sessions. In Condition 1, 4 pigeons were food deprived prior to each session and exposed to one session every 4th day. Condition 2 was identical except that the pigeons began each session at their ad-lib weights. Condition 3 was identical to Condition 2 except that sessions were conducted on consecutive days. Condition 4 was identical to Condition 3 except that the subjects (2 pigeons from Conditions 1–3 plus a naive pigeon) could obtain reinforcers much less frequently. In all of the conditions, the pigeons consistently chose the smaller, less delayed reinforcers; the pigeons were impulsive. The restriction of food access caused a disruption in the diurnal pattern of feeding, but did not decrease impulsiveness even in this 23-h live-in procedure.     

The determination of direction in landmark-based spatial search in pigeons: A further test of the vector sum model

In four experiments, pigeons were trained to find hidden food at a constant location with respect to one or two arrays of landmarks. On crucial tests, the birds were presented with conflicting cues associated with two different directions, which were 90° apart from the center of the search space at the same radial distance. The direction-averaging model predicts that the radial distance of search should not change on these tests, compared with radial distance of search on control tests without conflicting cues. The vector-averaging (vector sum) model predicts that when pigeons average the two conflicting cues, the radial distance of search should be shorter. Results support the direction-averaging model and suggest that distance and direction are independently computed in landmark-based search. Multiple sources are averaged by pigeons in determining direction.     

Independence of the amount and delay ratios in the generalized matching law

Eight pigeons chose between pairs of different sizes and delays of reinforcement scheduled according to nonindependent concurrent variable-interval variable-interval schedules. The results were best described by the generalized matching law, where the relative effects of amount and delay on preference are independent and multiplicative. Order of presentation of the conditions had a significant effect on preference that was best represented in the model by a modification of the bias parameter.     

A Descriptive Analysis of Elite-Level Racquetball

In this study, we used social cognitive career theory (Lent, Brown, &; Hackett, 1994) to examine the development of female athletes' career interest in coaching and, specifically, the impact of contextual factors (female coaching role models, working hours, and perceived discrimination) on coaching self-efficacy and outcome expectations. Participants were 205 predominantly White, heterosexual female student athletes. A path analysis indicated that role models and working hours predicted coaching self-efficacy, which predicted coaching outcome expectations. Additionally, coaching self-efficacy, coaching outcome expectations, and contextual factors predicted coaching interest. Practical implications are discussed as well as suggestions for further research in this relatively unexplored area.