Growth and Production of Golden Shiner, Notemigonous crysoleucas, Under Different Stocking Densities and Feeding Rates

Experiments on the effects of stocking densities and feeding rates on growth and production of golden shiner were conducted under laboratory conditions. The stocking densities were 20, 28 and 36 fry per 60 gal of water. The fish in tanks with 28 fry were fed at 1, 3 and 5% feeding rates and the rest were fed at 5% feeding rate. A 5% feeding rate was found to be essential for good production. The stocking density of 20 fry (400 lb/acre production) with 5% feeding rate yielded better growth in weight and length and better production than the rest of the experimental conditions

On the Heterogeneity of Dowry Motives

Dowries have been modeled as pre-mortem bequests to daughters or as groom-prices paid to in-laws. These two classes of models yield mutually exclusive predictions, but empirical tests of these predictions have been mixed. We argue that the heterogeneity of findings can be explained by a heterogeneous world--some households use dowries as a bequest and others use dowries as a price. We estimate a model with heterogeneous dowry motives and use the predictions from the competing theories in an exogenous switching regression to place households in the price or bequest regime. Our empirical strategy generates multiple, independent checks on the validity of regime assignment. Using retrospective marriage data from rural Bangladesh, we find robust evidence of heterogeneity in dowry motives in the population; that bequest dowries have declined in prevalence and amount over time; and that bequest households are better off compared to price households on a variety of welfare measures.

Stress versus temperature dependent activation energies in creep

The activation energy for creep at low stresses and elevated temperatures is lattice diffusion, where the rate controlling mechanism for deformation is dislocation climb. At higher stresses and intermediate temperatures, the rate controlling mechanism changes from that of dislocation climb to one of obstacle-controlled dislocation glide. Along with this change, there occurs a change in the activation energy. It is shown that a temperature-dependent Gibbs free energy does a good job of correlating steady-state creep data, while a stress-dependent Gibbs free energy does a less desirable job of correlating the same data. Applications are made to copper and a LiF-22 mol. percent CaF2 hypereutectic salt

Optimization of a low-energy, high brightness electron gun for inverse photoemission spectrometers

Availability of a low-energy, high current electron gun delivering a well-focused spot on the sample is essential for the inverse photoelectron spectroscopy. We have optimized an electron gun to obtain the maximum beam current at all electron kinetic energies of relevance with a reasonably small focus spot. Here we present the design, the procedure for the optimization, as well as the resulting characteristics of the electron gun

An exploratory study to determine students' perceptions of the value of interaction in an Australian classroom context and the perceived impact on learning outcomes

Interaction has long been a defining and critical component of the educational process, whatever the classroom context (Anderson 2003). This paper presents findings of a study to explore the attitudes of students at an Australian university towards various types interactivity in the classroom. The study also investigates students perceptions of how interactivity in the classroom impacts on cognitive, affective and behavioural learning outcomes. In a recent review of the literature Muirhead & Juwah (2003) argue that interactivity is critical in underpinning the learning process in face-to-face, campus based and distance and online education. They say that interactions serve a diverse range of functions in the educational process, which include learner to learner, learner to content, learner to tutor, learner to technology, tutor to content, tutor to technology, content to content. These functions promote and enhance the quality of active, participative learning in a learning environment. However, literature indicates that attitudes towards active learning involving greater interactivity varies across students and between students and lecturers (Billings, Connors, & Skiba 2001). Investigation into student attitudes of the value and effectiveness of interaction is of particular interest for educators who are adapting the learning of a diverse range of students, including oncampus, distance, international, under and postgradute students. Much of the existing research into classroom interaction was grounded in the behaviourist and cognitive sciences approach to learning and teaching, where traditional classroom interaction placed the teacher at the centre of all activities as transmitter of knowledge and co-coordinator of student interaction (McLoughlin 2002). Those studies predate the recent application of constructivism (Bonk and Cunningham 1998) and social learning theory (Bandura (1977), and the emphasis on building life long learning skills. This research will contribute to current discussion about the role of interaction in learning, based on a constructivist approach to developing life long learning skills. This paper will present the findings of an exploratory study of students’ attitudes to various types of interaction in a classroom context. The first step of this exploratory study will employ a focus group approach to gather data from on campus students to identify the key issues that emerge from this data. These findings will be used to design a survey instrument to implement a follow-up research project