Acquiring Articles through Unmediated, User-Initiated Pay-Per-View Transactions: An Assessment of Current Practices

Depressed economic times often lead libraries to consider new practices, including alternatives to the traditional subscription model. This column discusses a pay-per-view (PPV) model for acquiring journal articles whereby a library creates an account with a content provider through which authenticated users can purchase articles at the library’s expense. To gain insight into the current use of this model, the paper draws on both a literature review and the results of a survey assessing the practices of academic libraries with experience acquiring articles through unmediated, user-initiated pay-per-view transactions. The future of the PPV model as well as issues and challenges that it raises are also considered

Mechanics of musculoskeletal repair devices

This paper applies the mechanics of engineering science and materials to the understanding of clinical devices used in Orthopaedics and Trauma. The rigidity of devices is described to be a function of material stiffness and its geometry relative to the loading axes. Structures are more rigid under loads that are applied along their long axes and are more flexible under bending and torsion, which increases with length. This may be applied to an individual plate, screw or bone and to the entire construct. Increasing the thickness of a plate greatly increases rigidity as a third power relationship exists between these variables. Similarly, increasing the diameter of a rod increases its rigidity by a fourth power relationship. A hollow cylindrical cross-section, as found in long bones, provides the most effective rigidity to weight ratio when complex stresses are applied. This paper provides examples to reinforce basic structural mechanics applied to medical devices

Supporting adolescent athletes' dual careers: The role of an athlete's social support network

Objectives The objectives of this study were to, (a) understand the role of the social support network in facilitating adolescent athletes' dual careers in sport and education, and; (b) gain insights into the factors that may optimize the provision of such support. Design A two-stage qualitative study. Method In stage one, four different sport and education settings in the UK were examined: A tennis academy, a football academy, a national field hockey squad, and a high-performance swimming squad. Interviews were conducted with two athletes and associated significant others from each setting. In stage two, nine current or former international athletes from a variety of sports and countries recalled their experiences of managing a dual career. Analysis was conducted following the procedures outlined by Miles, Huberman, and Saldaña (2014). Results Overall, athletes in stage one and two perceived that to maintain their dual careers, they were heavily dependent upon the support of significant others. The role of the support network was to recognize the demands of a dual career, anticipate problems, value education, minimize barriers, and create autonomy-supportive environments. Key factors to optimize such support were focusing on the whole person, providing integrated support, and fostering a culture that promotes continuing education. Conclusions Results indicate that athletes require particular types of support within their home, at school, and in their sport context to be able to manage their dual career. However, a range of individual and group-level factors may influence the extent to which such support is available to athletes

Associative / Dissociative Cognitive Strategies in Sustained Physical Activity: Literature Review and Proposal for a Mindfulness-Based Conceptual Model

We reviewed and summarize the extant literature on associative/dissociative cognitive strategies used by athletes and others in circumstances necessitating periods of sustained attention. This review covers studies published since a prior publication by Masters and Ogles (1998), and, in keeping with their approach, offers a methodological critique of the literature. We conclude that the distinction between associative and dissociative strategies has outlived its usefulness since initially proposed in an earlier era of ground-breaking research by Morgan and Pollock (1977) that was influenced to some extent by psychodynamic thinking. In recent years there has been an evolutionary shift in concepts of sustained attention toward mindfulness—moment-by-moment attention—that has had a significant impact on conceptual models and clinical practice in diverse areas including stress management, psychotherapy, and athletic performance. We propose that future research on cognitive activity in sustained performance settings be embedded in a mindfulness-based conceptual model

Is Natural Selection an Outworn Term?

Author Institution: Dr. Hess and Clark, Inc., Ashland, Ohi

Greenhouse gases in intensive agriculture: contributions of individual gases to the radiative forcing of the atmosphere

Includes bibliographical references (pages 1924-1925).Agriculture plays a major role in the global fluxes of the greenhouse gases carbon dioxide, nitrous oxide, and methane. From 1991 to 1999, we measured gas fluxes and other sources of global warming potential (GWP) in cropped and nearby unmanaged ecosystems. Net GWP (grams of carbon dioxide equivalents per square meter per year) ranged from 110 in our conventional tillage systems to -211 in early successional communities. None of the annual cropping systems provided net mitigation, although soil carbon accumulation in no-till systems came closest to mitigating all other sources of GWP. In all but one ecosystem, nitrous oxide production was the single greatest source of GWP. In the late successional system, GWP was neutral because of significant methane oxidation. These results suggest additional opportunities for lessening the GWP of agronomic systems.Publisher version: http://www.jstor.org/stable/3077685

Supporting adolescent athletes' dual careers: The role of an athlete's social support network

© 2018 Objectives: The objectives of this study were to, (a) understand the role of the social support network in facilitating adolescent athletes' dual careers in sport and education, and; (b) gain insights into the factors that may optimize the provision of such support. Design: A two-stage qualitative study. Method: In stage one, four different sport and education settings in the UK were examined: A tennis academy, a football academy, a national field hockey squad, and a high-performance swimming squad. Interviews were conducted with two athletes and associated significant others from each setting. In stage two, nine current or former international athletes from a variety of sports and countries recalled their experiences of managing a dual career. Analysis was conducted following the procedures outlined by Miles, Huberman, and Saldaña (2014). Results: Overall, athletes in stage one and two perceived that to maintain their dual careers, they were heavily dependent upon the support of significant others. The role of the support network was to recognize the demands of a dual career, anticipate problems, value education, minimize barriers, and create autonomy-supportive environments. Key factors to optimize such support were focusing on the whole person, providing integrated support, and fostering a culture that promotes continuing education. Conclusions: Results indicate that athletes require particular types of support within their home, at school, and in their sport context to be able to manage their dual career. However, a range of individual and group-level factors may influence the extent to which such support is available to athletes

Integration of Plant Defense Traits with Biological Control of Arthropod Pests: Challenges and Opportunities

Crop plants exhibit a wide diversity of defensive traits and strategies to protect themselves from damage by herbivorous pests and disease. These defensive traits may be naturally occurring or artificially selected through crop breeding, including introduction via genetic engineering. While these traits can have obvious and direct impacts on herbivorous pests, many have profound effects on higher trophic levels, including the natural enemies of herbivores. Multi-trophic effects of host plant resistance have the potential to influence, both positively and negatively, biological control. Plant defense traits can influence both the numerical and functional responses of natural enemies; these interactions can be semiochemically, plant toxin-, plant nutrient-, and/or physically mediated. Case studies involving predators, parasitoids, and pathogens of crop pests will be presented and discussed. These diverse groups of natural enemies may respond differently to crop plant traits based on their own unique biology and the ecological niches they fill. Genetically modified crop plants that have been engineered to express transgenic products affecting herbivorous pests are an additional consideration. For the most part, transgenic plant incorporated protectant (PIP) traits are compatible with biological control due to their selective toxicity to targeted pests and relatively low non-target impacts, although transgenic crops may have indirect effects on higher trophic levels and arthropod communities mediated by lower host or prey number and/or quality. Host plant resistance and biological control are two of the key pillars of integrated pest management; their potential interactions, whether they are synergistic, complementary, or disruptive, are key in understanding and achieving sustainable and effective pest management