Storage and retrieval considerations of binary data bases

A binary approach to data storage and retrieval is introduced. It views the data base as a two-dimensional matrix that relates entities to all possible values the attributes of these entities may take. As such, it provides a unified solution to the two conflicting types of data base transactions—operational and managerial. An analytical investigation of the feasibility of binary storage and a compression method for reducing meaningless areas of the matrix are presented. Storage efficiencies of binary and conventional inverted file methods are compared and evaluated. An analysis of retrieval considerations associated with the binary matrix is given, particularly the issue of going from high to low orders of compression. Results of these analyses indicate that the binary data base's efficiency increases with increases in query complexity. Future research directions are sited and discussed.     

Computed tomography‐enhanced anatomy course using enterprise visualization

Rapid changes in medical knowledge are forcing continuous adaptation of the basic science courses in medical schools. This article discusses a three‐year experience developing a new Computed Tomography (CT)‐based anatomy curriculum at the Sackler School of Medicine, Tel Aviv University, including describing the motivations and reasoning for the new curriculum, the CT‐based learning system itself, practical examples of visual dissections, and student assessments of the new curriculum. At the heart of this new curriculum is the emphasis on studying anatomy by navigating inside the bodies of various living individuals utilizing a CT viewer. To assess the students’ experience with the new CT‐based learning method, an anonymous questionnaire was administered at the end of the course for three consecutive academic years: 2008/2009, 2009/2010, 2010/2011. Based upon the results, modifications were made to the curriculum in the summers of 2009 and 2010. Results showed that: (1) during these three years the number of students extensively using the CT system quadrupled (from 11% to 46%); (2) students' satisfaction from radiologists involvement increased by 150%; and (3) student appreciation of the CT‐based learning method significantly increased (from 13% to 68%). It was concluded that discouraging results (mainly negative feedback from students) during the first years and a priori opposition from the teaching staff should not weaken efforts to develop new teaching methods in the field of anatomy. Incorporating a new curriculum requires time and patience. Student and staff satisfaction, along with utilization of the new system, will increase with the improvement of impeding factors. Anat Sci Educ 6: 332–341. © 2013 American Association of Anatomists.     

The scattering of X-rays

Present Status of the Problem.—The scattering of X-rays is one of the outstanding problems of electromagnetic radiation which has not been solved satisfactorily. All theories (based on classical electrodynamics) presented thus far do not explain either the diminution in the scattering coefficient, or the observed asymmetry in the scattering, or both. Among such theories we may mention:J. J. Thompson's Theory.—Assuming that the scattering is done by a point electron, and making use of certain additional hypotheses, Thomson showed that the scattering coefficient of any substance is given by

$\text{σ=}\text{8πNpe}{}^4\text{3m}{}^2\text{c}{}^4$

and that the intensity of the scattered radiation is given by

$\text{I}{}_{\mathrm{\theta }}\text{=I}\text{e}{}^4\text{(I+cos}{}^2\text{θ)}\text{2r}{}^2\text{m}{}^2\text{c}{}^4$

where N is the number of atoms per c.c., p the number of electrons per atom, e the electronic charge, m the electronic mass, c the velocity of light, I_θ the intensity of the scattered radiation at an angle θ between the incident beam and the radius vector joining the centre of the electron and the point P distant r from the electron, and I is the intensity of the incident beam. This theory explains neither the asymmetry nor the decrease in the coefficient of scattering.Schott's Theory.—Among other things, the assumption is here made that the atom consists of coaxal rings of electron. The electrons in each ring are spaced at equal intervals and revolve with a uniform angular velocity, which, however, may be different for different rings. This theory fails to explain the observed diminution in the scattering coefficient.Debye's Theory.—In its essentials, Debye's theory has the same merits and demerits as that of Schott. Debye assumes that all the electrons in an atom are arranged in a single ring, and that they are spaced at equal intervals. This theory (and also Schott's theory) explains the asymmetry and the “excess scattering,” but is altogether unable to explain the diminution in the scattering coefficient.Modification of the Classical Theory.—The present paper presents a discussion of the possibility of modifying the classical theory (that of J. J. Thomson) so as to account for the decrease in the scattering coefficient as well as the dissymmetry. By assuming that the electron is made up of a number of parts—for simplicity, of two parts—it has been found possible to account for the diminution in the scattering coefficient without, at the same time, explaining the observed asymmetry. To accomplish both objects is what was aimed at in the combination of the present work with that of Debye. In this research the goal has not been perfection between predicted and observed results, but rather to discuss some possible modifications of the classical theory and their consequences.     

The road to self-assessment: exemplar marking before peer review develops first-year students’ capacity to judge the quality of a scientific report

Lack of clarity about assessment criteria and standards is a source of anxiety for many first-year university students. The Developing Understanding of Assessment for Learning (DUAL) programme was designed as a staged approach to gradually familiarise students with expectations, and to provide opportunities for the development of the skills required to successfully complete assessment tasks. This paper investigated the students’ perceptions of the first two components of the DUAL programme, which assist first-year biology students to engage with stated assessment criteria and standards in order to develop their capacity to make judgements about scientific report exemplars, their peers’ scientific reports and ultimately their own. The study found strong evidence (96% of responses) that the marking and discussion of exemplar reports with peers and demonstrators clarified expectations of scientific report writing. A key feature of this element of DUAL was the opportunity for structured discussion about assessment criteria and standards between peers and markers (demonstrators). During these discussions, students can clarify explicit statements and develop a tacit knowledge base to enhance their ability to judge the quality of others’ work and their own. The peer review exercise (the second element of DUAL) was not rated as highly, with 65% of students finding the process helpful for improving their report. The negative reactions by a sizeable minority of students highlight the need to clearly communicate the expectations and benefits of peer review, with a focus on how the process of giving feedback to peers might benefit a student as much as receiving feedback on their own report.     

A Model of Academic Self-Concept for High School Hispanic Students in New York

This study examined how Hispanic students’ academic self-concept influences the independent variables of family academic expectations, peer relationships, schoolwork, and student–teacher relationships. A survey was administered to 222 ninth-grade students in Long Island, New York, 99 of whom self-identified as Hispanic. A structural equation model analyzed the influence of the independent variables on the dependent variable, academic self-concept. A multiple regression analysis indicated that peer relationships, family academic expectations, and schoolwork were significant predictors of students’ academic self-concept. Peer relationships was a modifying variable on students’ academic self-concept.     

Time Comparison between the Cross-Over and Jab-Step Starts

Abstract

The purpose of this investigation was to evaluate and quantify physiological differences among groups of distance runners. The subjects included 20 elite distance runners (8 marathon, 12 middle-long distance) and 8 good runners. Working capacity and cardiorespiratory function were determined by submaximal and maximal treadmill tests, and body composition by hydrostatic weighing. The variables studied were maximum oxygen uptake ([Vdot]O₂ max), [Vdot]O₂ submax, lactic acid submax, lean body weight, and fat weight. MANOVA showed that the good runners differed from the elite runners (p < 0.01) and the elite marathon runners differed from the elite middle-long distance runners (p < 0.05). Discriminant analysis showed that both functions were significant. The first was a general physiological efficiency factor that separated the good and elite runners. The second separated the elite marathon and middle-long distance groups. The second function showed that the marathon runners had lower lactic acid submax values. The middle-long distance runners had higher [Vdot]O₂ max values. Classification analysis was used to evaluate the accuracy of the discriminant analysis; 80% of the elite runners were correctly classified as marathon or middle-long distance runners. The discriminant functions were used to develop a multivariate scaling model for evaluating distance runners. Two premier runners, one marathoner (F. Shorter) and one middle-long distance runner (S. Prefontaine), were found to be at the extremes of the scale. The data showed that the discriminant functions provided a valid model for evaluating differences among elite distance runners.     

On the potential for using immersive virtual environments to support laboratory experiment contextualisation

This paper explores the hypothesis that embedding a laboratory activity into a virtual environment can provide a richer experimental context and hence improve the understanding of the relationship between a theoretical model and the real world, particularly in terms of the model's strengths and weaknesses. While an identified learning objective of laboratories is to support the understanding of the relationship between models and reality, the paper illustrates that this understanding is hindered by inherently limited experiments and that there is scope for improvement. Despite the contextualisation of learning activities having been shown to support learning objectives in many fields, there is traditionally little contextual information presented during laboratory experimentation. The paper argues that the enhancing laboratory activity with contextual information affords an opportunity to improve students’ understanding of the relationship between the theoretical model and the experiment (which is effectively a proxy for the complex real world), thereby improving their understanding of the relationship between the model and reality. The authors propose that these improvements can be achieved by setting remote laboratories within context-rich virtual worlds.     

Balancing Head and Heart: The Importance of Relational Accountability in Community-University Partnerships

In this article we introduce a “head and heart” approach to community-engaged scholarship. Through the literatures of Aboriginal scholarship and engaged scholarship we reflect on a community-university research and program development project undertaken in response to health and education concerns of Aboriginal people in Canada. We suggest that the head and heart approach was crucial to the program’s success and provides access to an ethical space where multiple worldviews are recognized and where the importance of relational accountability becomes evident. We then examine the implications of this approach for engaged scholarship and higher education practices.