Propagation of thornless blackberries utilizing adventitious shoots from root cuttings

Studies were conducted in early 2003 to determine the effect of root source and length on yield of adventitious shoots from root cuttings and on subsequent plant yield for University of Arkansasdeveloped thornless blackberries. In the first study, roots from ‘Arapaho’ and ‘Apache’ plants grown in an aboveground bed containing commercial potting soil were compared to field-grown roots. Bed-grown roots averaged 6.9 shoots per 15 cm root cutting while field grown roots averaged 3.4. ‘Apache’ produced more shoots/root cutting compared to Arapaho, (5.9 vs. 4.4 shoots/root cutting, respectively). In a comparison of 15- vs. 30-cm-long root cuttings of ‘Apache’, ‘Arapaho’, and ‘Ouachita’, shoot yield of 30-cm roots was higher than that of 15 cm roots, but total yield of shoots per root unit was not increased by the longer root cuttings. Rooting of adventitious shoots neared 100% in both studies, and resulting quality of plants from these shoots was very good. This minor modification to the traditional method of planting root pieces to yield individual plants could lead to a more efficient and productive yield of propagules. The use of adventitious shoots from root cuttings for blackberry plant propagation appears to be a viable method for nurserymen to consider

Student understanding of the Boltzmann factor

We present results of our investigation into student understanding of the physical significance and utility of the Boltzmann factor in several simple models. We identify various justifications, both correct and incorrect, that students use when answering written questions that require application of the Boltzmann factor. Results from written data as well as teaching interviews suggest that many students can neither recognize situations in which the Boltzmann factor is applicable, nor articulate the physical significance of the Boltzmann factor as an expression for multiplicity, a fundamental quantity of statistical mechanics. The specific student difficulties seen in the written data led us to develop a guided-inquiry tutorial activity, centered around the derivation of the Boltzmann factor, for use in undergraduate statistical mechanics courses. We report on the development process of our tutorial, including data from teaching interviews and classroom observations on student discussions about the Boltzmann factor and its derivation during the tutorial development process. This additional information informed modifications that improved students' abilities to complete the tutorial during the allowed class time without sacrificing the effectiveness as we have measured it. These data also show an increase in students' appreciation of the origin and significance of the Boltzmann factor during the student discussions. Our findings provide evidence that working in groups to better understand the physical origins of the canonical probability distribution helps students gain a better understanding of when the Boltzmann factor is applicable and how to use it appropriately in answering relevant questions

A Study of the Temporal Changes in Offshore Macrofauna in the Northern Gulf of Mexico During the Development of the Offshore Oil Industry

Paper by John R. Thompso

Collaborative Research: Research on the Learning and Teaching of Thermal Physics

Groups at Iowa State University and the University of Maine will collaborate in a coordinated program of research and research-based curriculum development in thermal physics, targeting both introductory general physics courses and advanced-level undergraduate courses. The research component involves one-on-one student interviews, written pre- and post-test questions, and multiple-choice surveys. This research is then applied to the development of curricular materials intended to improve student understanding in a manner consistent with active-learning methods previously shown be effective in physics instruction. The curriculum will in turn be evaluated for its effectiveness at addressing the student difficulties previously identified through research. This project will provide insight into student learning of fundamental concepts in thermal physics. Instructional materials will be designed specifically to address student difficulties found in the research, and will utilize proven pedagogical techniques to increase their effectiveness. The dissemination of both the research results and of the curricular materials will improve instruction in thermal physics nationally and internationally

Collaborative Research: Paradigms in Physics: Creating and Testing Materials to Facilitate Dissemination of the Energy and Entropy Module

Topics in statistical and thermal physics have long been problematic in the undergraduate curriculum. To many students, the subject matter is abstract and theoretical and often requires mathematical tools they lack. This project addresses the challenge of teaching upper-division thermal and statistical mechanics by building on the Energy and Entropy (E&E) paradigm developed through the Paradigms in Physics Project at Oregon State University and a physics education research project at the University of Maine. E&E takes a radically different approach to statistical mechanics, incorporating the issues of quantum mechanics and measurement at its core and focusing on entropy as the Principle of Least Bias. In the approach, thermodynamic systems are treated as large, i.e. macroscopic, quantum systems that are not perfectly isolated from the remainder of the universe. This external interaction has enormous consequences that when taken into account clarifies thermodynamics\u27 substance, with thermal variables now understood as macroscopic quantum averages and thermal probabilities as macroscopic quantum probabilities. An entropy postulate then plays the ultimate and crucial role of match maker in this marriage. As part of the current project, E&E curricular materials are being further refined and the materials are being field tested at Oregon State University and at collaborator sites at Ithaca College and Pacific University, a detailed instructor\u27s manual is being prepared, and an education research project is being conducted to examine the efficacy of the approach and materials in supporting student learning of these concepts in advanced courses

The applicability of self-regulation theories in sport : goal adjustment capacities, stress appraisals, coping and well-being among athletes

Objectives: We examined a model, informed by self-regulation theories, which included goal adjustment capacities, appraisals of challenge and threat, coping, and well-being. Design: Prospective. Methods: Two hundred and twelve athletes from the United Kingdom (n = 147) or Australia (n = 65), who played team (n = 135) or individual sports (n = 77), and competed at international (n = 7), national (n = 11), county (n = 67), club (n = 84), or beginner (n = 43) levels participated in this study. Participants completed measures of goal adjustment capacities and stress appraisals two days before competing. Athletes also completed questions on coping and well-being within three hours of their competition ending. Results: The way an athlete responds to an unattainable goal is associated with his or her well-being in the period leading up to and including the competition. Goal reengagement positively predicted well-being, whereas goal disengagement negatively predicted well-being. Further, goal reengagement was positively associated with challenge appraisals, which in turn was linked to task-oriented coping, and task-oriented coping positively associated with well-being. Conclusion: When highly-valued goals become unattainable, consultants could encourage athletes to seek out alternative approaches to achieve the same goal or help them develop a completely new goal

WHY DO FARMERS FORWARD CONTRACT IN FACTOR MARKETS?

This study investigated farmers' incentives to forward purchase inputs. A model of farmer decision making was used to derive an optimal forward contracting rule. Explicit in the model was the tradeoff between the quantity of input to be purchased in advance, and the remaining portion to be purchased later on the spot market. Results indicated that the primary reasons farmers contract inputs are to reduce risk and to speculate on favorable price moves. A numerical example of fertilizer used in corn production indicated that the size of the price discount was the dominant factor in forward contracting decisions.Farm Management,

Identifying Student Difficulties with Entropy, Heat Engines, and the Carnot Cycle

We report on several specific student difficulties regarding the Second Law of Thermodynamics in the context of heat engines within upper-division undergraduates thermal physics courses. Data come from ungraded written surveys, graded homework assignments, and videotaped classroom observations of tutorial activities. Written data show that students in these courses do not clearly articulate the connection between the Carnot cycle and the Second Law after lecture instruction. This result is consistent both within and across student populations. Observation data provide evidence for myriad difficulties related to entropy and heat engines, including students' struggles in reasoning about situations that are physically impossible and failures to differentiate between differential and net changes of state properties of a system. Results herein may be seen as the application of previously documented difficulties in the context of heat engines, but others are novel and emphasize the subtle and complex nature of cyclic processes and heat engines, which are central to the teaching and learning of thermodynamics and its applications. Moreover, the sophistication of these difficulties is indicative of the more advanced thinking required of students at the upper division, whose developing knowledge and understanding give rise to questions and struggles that are inaccessible to novices