Equilibrium and non-equilibrium models of livestock population dynamics in pastoral Africa: their relevance to Arctic grazing systems

Equilibrium grazing systems are characterised by climatic stability that results in predictable primary production. Non-equilibrium grazing systems receive low and erratic rainfall that produces unpredictable fluctuations in forage supplies. In semi-arid Africa, these two types of environment present livestock owners with very different management problems. Identifying and maintaining optimal stocking rates is useful in equilibrium systems because livestock reproduce and produce at a rate determined by the availability of feed, which is an inverse function of stock density. The only problem is to determine what stocking rate is optimal. The correct stocking rate for a grazing system will vary depending on the production strategy and the social and economic circumstances of the rangeland user - there is no single, biologically predetermined optimum density. Variable rainfall complicates the picture in non-equilibrium systems. Set stocking rates of any kind have little value if fluctuation in rainfall has a stronger effect than animal numbers on the abundance of forage. More useful in such an environment is the ability to adjust stocking rates rapidly to track sudden changes in feed availability. In semi-arid Africa, the distinction between equilibrium and non-equilibrium systems hinges on the reliability of rainfall. In northern latitudes, at least three primary variables important for plant growth and the survival of herbivores must be considered: rainfall, snow cover and temperature. It is probably not useful to consider arctic grazing systems as equilibrium systems; on the other hand, the non-equilibrium models developed in hot semi-arid environments do not capture the range of complexity which may be an inherent feature of plant-herbivore dynamics on the mountain and tundra pastures where reindeer are herded or hunted

New Wave Computer Technology and the Administration of Speech Communication Performance Courses

The article talks about the continued interest of the speech communication field in technology-supported instruction. Earlier detailed descriptions of teaching/learning laboratories in speech communication are based upon older computer-assisted instruction models and such laboratories were financially out of reach for most small-to-average sized departments. Recent, dramatic enhancements of the memories and processing speeds of microcomputers has made them ideal for recording, editing, and replaying sound supported motion picture clips of speech presentations. Clearly, evaluating student performance and providing substantial and prompt instructional feedback can easily be accommodated by the course web site. Aside from the interactive testing and automated grading features described above, computer-assisted grading and evaluation of speaking performances are supported by specialized forms software and the personal data assistant or PDA connected to a server

Computer-Assisted Evaluation of Speaking Competencies in the Basic Speech Course

This article discusses the computer-assisted evaluation of speaking competencies in the basic speech course. Whenever a college-level course utilizes a number of instructors and sections, administrators responsible for ensuring the quality of that course become increasingly concerned about issues of equivalency or the extent to which students in the various sections of the course are receiving essentially the same educational experience. educators have recommended the use of student portfolios in courses featuring public speaking. In this instructional strategy, a student\u27s work during a course is compiled and reviewed periodically throughout the academic term. This improvements will dramatically enhance record keeping for both teaching and research purposes

Perspectives on Norm-Referenced and Criterion-Referenced Grading in Introductory Speech Performance Courses

This article explores the integration and amalgamation of norm-referenced and criterion-referenced perspectives in a manner that is particularly appropriate for use in basic or introductory speech communication performance courses. Possibly the greatest virtue of using criterion-referenced grading of speeches in a basic speech performance course is the generation of positive affect toward performance. Because students identify with their speeches, they are much more demoralized by negative feedback about their work on these assignments than for others. By setting appropriate minimal performance criteria that most beginning students can achieve, morale remains high, there is an atmosphere of success, and, in fact, most students will have mastered the skill levels that one can reasonably expect from a graduate of the basic course. For the content aspect of the course, norm-referenced examinations provide appropriate distributions that, when combined with speaking scores, still support the grade expectations of the school or department. Now, somewhat more of the variance in final course grades is accounted for by the norm-referenced aspect of the dualistic grading system. In summary, there are important benefits in using both grading methods. Students prefer criterion-referenced grading for performances and are especially appreciative of the fact that they can work toward mastery using whatever reasonable amount of time they need. Secondly, they like norm-referenced grading for the content components of the course because that\u27s what they expect on the basis of past experience. Third, elevating the difficulty level of content exams seldom creates new problems, especially when the results are somewhat positively curved

Range-Based Livestock Production in Turkmenistan

Turkmenistan retains a centralized system of livestock production in which many critical assets are owned by the state. Though technically in the temperate zone, the country\u27s climate is harsh and unstable. Groundwater resources are unevenly distributed, leaving many potential grazing areas seasonally inaccessible due to lack of drinking water for livestock. This paper summarizes the results of a three-year study of rangelands, livestock production, flock economics and land tenure at two study sites, one in central and the other in eastern Turkmenistan. The results of this study suggest that pastoral communities in Turkmenistan have coped remarkably well with the institutional changes that followed the demise of the Soviet Union, and with the country\u27s persistently unstable climate and scarce natural resources

Communication Education Transformations: Implications for Curricular Change

This article explores the implications of communication education transformations for curricular change in the U.S. Differences in education and training between public relations (PR) practitioners and journalists reflect, in part, effects of certain pressures brought to bear upon these professions. Any edge which graduates may have in the marketplace will depend on the extent to which their communication programs have focused on initial detection and measurement of related talents, skill development and enhancement, and discovery of communication-related careers that depend on the integration and application of these skills. With respect to faculty placement, infusing PR faculty into existing communication programs will produce creative collegial associations among scholars serving to stimulate innovative lines of teaching and research

A large deformation and thermomechanically coupled interface approach

Interfaces are formed e.g. by the contact surface of different materials of heterogeneous solids or by crack flanks within damaged bodies. Since the combination of temperature evolution and mechanical loadings influences significantly the deformation and thermal behavior of interfacial layers, these failure layers are thermally and mechanically described in the presented approach in a fully coupled sense. Thermomechanical interface descriptions can be used for prediction of crack propagation and, as soon as a designated failure layer exists, to predict the thermomechanical behavior of the observed solid. The presented interface approach for finite deformation introduces a consistent framework derived from principle thermodynamical laws

Grading Policy and Student Retention

This article discuses two policies that work at cross purposes to one another which university administrators and faculty works collaboratively with. Schools are actively resisting grade inflation trends while at the same time seeking to retain students. The article describes the borderline student, a category of at risk student often overlooked, yet numerous. It is found that academic performance was the highest ranked risk factor, accounting for approximately 20% of the variance, while behavior and coping skills was a distant second, accounting for only 6% of the risk factor variance. Borderline students can be efficiently rescued with modest outlays of additional institutional resources and are more likely to persist than students with less ability or more pernicious learning difficulties