Parameter study using a finite element simulation of a carving Alpine ski to investigate the turn radius and its dependence on edging angle,load, and snow properties

For ski manufacturers, it is important to know how a given ski-binding system performs under different loading conditions. Important performance parameters are the ski deformation and the resulting turn radius. This study focuses on carving turns. The aims of this study were: (1) to investigate the dependence of the turn radius on edging angle, load on the binding, and snow hardness using a finite element (FE) simulation, and (2) to compare the results with predictions of a frequently used model introduced by Howe. The FE simulation used a quasi-static approach (similar to Howe’s model), but the ski–snow interaction model incorporated the groove that forms in the snow during a carved turn. Up to edging angles of 40°, the results of the FE simulation agreed well with Howe’s model. However, for large edging angles (>50°) the calculated turn radius leveled out, whereas Howe’s model tends to zero. This effect was more pronounced for soft snow than for hard snow conditions. Increasing forces on the binding caused a decrease in the calculated turn radii. In summary, the FE simulation showed that particularly at large edging angles the groove in the snow needs to be considered in models of the ski–snow interaction or in computations of the turn radius.     

A jaundiced bodybuilder Cholestatic hepatitis as side effect of injectable anabolic–androgenic steroids

The use of anabolic steroids is prevalent in recreational athletes. This case report describes a young amateur bodybuilder who was referred to our outpatient clinic with jaundice and loss of appetite due to cholestatic hepatitis. Additional tests including a liver biopsy made it likely that the hepatitis was caused by the injectable anabolic steroid trenbolone enanthate. Cholestatic hepatitis may not be limited to the use of oral anabolic–androgenic steroids, as is widely assumed. Therefore, and because of other side effects, the recreational use of all forms of anabolic steroids should be discouraged.     

Virtual worlds vs books and videos in history education

In this paper, we investigate an application of virtual reality and artificial intelligence (AI) as a technological combination that has a potential to improve the learning experience and engage with the modern generation of students. To address this need, we have created a virtual reality replica of one of humanity's first cities, the city of Uruk and populated this city with AI-controlled 3D avatars, which re-enact everyday life of ancient Sumerians in the period around 3000 B.C. Our hypothesis is that by immersing students into this environment and allowing them to learn by browsing through it and interacting with its virtual citizens can be more engaging and motivating than simply reading the corresponding history text or watching an educational video. To confirm this assumption, we have designed a study with three groups of students. One group was given a historical text about Uruk and everyday life of its citizens (created by our subject matter experts), the second group was shown a documentary video on Uruk and the third group was immersed into virtual Uruk and engaged into interactions with its virtual inhabitants. The outcomes of the study suggest that not only did people in the third group provide much more positive qualitative feedback about the learning experience, but they also showed a better comprehension of the study material by performing (on average) 20% better than the first two groups on the mini-exam that was conducted as a part of this study.     

Allchin's Shoehorn, or Why Science is Hypothetico-Deductive

Allchin's critique of my analysis of Galileo's discovery of Jupiter's moons, and of my characterization of science as hypothetico-deductive, contains several factual and conceptual errors. Thus, contrary to his attempt to paint scientific discovery in terms of blind search and limited induction, a careful analysis of the way humans spontaneously process information and reason supports a general hypothetico-deductive theory of human information processing, reasoning, and scientific discovery.     

The role of hypothetico-deductive reasoning and physical analogues of molecular interactions in conceptual change

Two hypotheses about theoretical concept acquisition, application, and change were tested. College biology students classified as intuitive, transitional, or reflective (hypothetico-deductive) reasoners were first taught two theoretical concepts (molecular polarity and bonding) to explain the mixing of dye with water, but not with oil, when all three were shaken in a container. The students were then tested in a context in which they misapplied the concepts in an attempt to explain the gradual spread of blue dye in standing water. Next students were taught another theoretical concept (diffusion), with and without the use of physical analogues. They were retested to see which students acquired the concept of diffusion and which students changed from use of the incorrect polarity and bonding concepts (i.e., the misconceptions) to use of the diffusion concept to correctly explain the dye's gradual spread. As predicted, the experimental/analogy group scored significantly higher than the control group on a posttest question that required the definition of diffusion. Also as predicted, hypothetico-deductive reasoning skill was significantly related to correct application of the diffusion concept and to a change from the misapplication of the polarity and bonding concepts to the correct application of the diffusion concept to explain the gradual spread of the blue dye. Thus, the results support the hypotheses that physical analogues are helpful in theoretical concept acquisition and that hypothetico-deductive reasoning is needed for successful concept application and change. Educational implications are drawn.     

Do We Have It? A Comparative Analysis of Library Journal Holdings and Works Referenced in Faculty Publications

Libraries often wonder if their collections can support their faculty’s research. Large citation databases, such as Scopus or Web of Science, can help automate such a review process. This session will present findings about to what extent faculty were able to complete their journal publications without utilizing interlibrary loan. Using data gathered from Scopus, the range and date of journals referenced by faculty at my home institution will be compared with holdings from my library’s electronic resources knowledge base to determine the level of overlap. Results will be presented by journal discipline to highlight any variation among the science, social science, and arts and humanities divisions. Special emphasis will be given to using this data to inform decisions about purchasing journal backfile collections.     

Self‐efficacy,reasoning ability,and achievement in college biology

This study compared the relationships of self‐efficacy and reasoning ability to achievement in introductory college biology. Based on the hypothesis that developing formal and postformal reasoning ability is a primary factor influencing self‐efficacy, a significant positive correlation was predicted between reasoning ability and degree of self‐efficacy to complete biological tasks. Further, reasoning ability was predicted to be more highly correlated with course achievement than self‐efficacy. The study involved pre‐ and posttesting 459 introductory biology students. Both self‐efficacy and reasoning ability increased during the semester. As predicted, self‐efficacy and reasoning ability were positively correlated. Depending on the nature of the achievement measure, reasoning ability accounted for some 15 to 30 times more variance in achievement than self‐efficacy. Also, as predicted, reasoning ability was a strong predictor of self‐efficacy, but self‐efficacy was not a strong predictor of reasoning ability. Self‐efficacy estimates and achievement were higher for the concrete tasks than for the formal tasks and higher for the formal tasks than for the postformal tasks. In general, students tended to overestimate their abilities to carry out the concrete, formal, and postformal tasks. Results support the study's working hypothesis that intellectual development continues for some students during the college years, that a postformal level of intellectual development exists, and that reasoning ability is a primary factor influencing both self‐efficacy and achievement. Student overestimation of their abilities may contribute to complacency, lack of effort, and to less than optimal achievement. Consequently, it may be advantageous early in the semester to provide students with particularly challenging tasks that “shock” them out of their complacency and perhaps increase their effort, their reasoning skills, and their achievement. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 44: 706–724, 2007     

The nature of advanced reasoning and science instruction

Although the development of reasoning is recognized as an important goal of science instruction, its nature remains somewhat of a mystery. This article discusses two key questions: Does formal thought constitute a structured whole? And what role does propositional logic play in advanced reasoning? Aspects of a model of advanced reasoning are presented in which hypothesis generation and testing are viewed as central processes in intellectual development. It is argued that a number of important advanced reasoning schemata are linked by these processes and should be made a part of science instruction designed to improve students' reasoning abilities. Concerning students' development and use of formal reasoning, Linn (1982) calls for research into practical issues such as the roles of task-specific knowledge and individual differences in performance, roles not emphasized by Piaget in his theory and research. From a science teacher's point of view, this is good advice. Accordingly, this article will expand upon some of the issues raised by Linn in a discussion of the nature of advanced reasoning which attempts to reconcile the apparent contradiction between students' differential use of advanced reasoning schemata in varying contexts with the notion of a general stage of formal thought. Two key questions will be discussed: Does formal thought constitute a structured whole? And what role does propositional logic play in advanced reasoning? The underlying assumption of the present discussion is that, among other things, science instruction should concern itself with the improvement of students' reasoning abilities (cf. Arons, 1976; Arons & Karplus, 1976; Bady, 1979; Bauman, 1976; Educational Policies Commission, 1966; Herron, 1978; Karplus, 1979; Kohlberg & Mayer, 1972; Moshman & Thompson, 1981; Lawson, 1979; Levine & linn, 1977; Pallrand, 1977; Renner & Lawson, 1973; Sayre & Ball, 1975; Schneider & Renner, 1980; Wollman, 1978). The questions are of interest because to date they lack clear answers, yet clear answers are necessary if we hope to design effective instruction in reasoning.     

The rejection of nonscientific beliefs about life: Effects of instruction and reasoning skills

Nine hundred fifty-four students in a large university nonmajors biology course were pretested to determine the extent to which they held nonscientific beliefs in creationism, orthogenesis, the soul, nonreductionism, vitalism, teleology, and nonemergentism. To test the hypothesis that hypothetico-deductive reasoning skills facilitate movement away from nonscientific beliefs, the degree to which those nonscientific beliefs were initially held and the degree to which they were modified during instruction were compared to student reasoning level (intuitive, transitional, reflective). As predicted, the results showed that the less skilled reasoners were more likely to initially hold the nonscientific beliefs and were less likely to change those beliefs during instruction. It was also discovered that less skilled reasoners were less likely to be strongly committed to the scientific beliefs.