VIRTUAL TEACHING CASES?AN EXPLORATORY STUDY

This research, when complete, will represent a prototype of the development of a virtual teaching case and the use and assessment of the initial versions of research instruments whose aim is the assessment of this new form of teaching case, or any type of teaching case, with regards to learning efficacy, gains, satisfaction, and environment. The purpose of this virtual teaching case (that is, a teaching case, embedded within a virtual world) is to leverage the rich heritage of casebased teaching while helping today’s students to learn by providing a more engaging environment where these students (experienced with multiplayer computer games and the Internet) can collaboratively practice project management skills such as planning scopes of work, schedules, and budgets—skills they have already learnt in class. In a virtual teaching case, students can experience the challenges of discovering problems; collaboratively creating, judging, and transforming resolutions; and reacting to changing circumstances

Selecting a Virtual World Platform for Learning

Like any infrastructure technology, Virtual World (VW) platforms provide affordances that facilitate some activities and hinder others. Although it is theoretically possible for a VW platform to support all types of activities, designers make choices that lead technologies to be more or less suited for different learning objectives. Virtual World platforms’ capabilities can be characterized in terms of the extent to which they are multiple or special purpose and the degree to which they support incorporation of few or many knowledge resources. Matching these capabilities with a framework for characterizing instructional approach and learning objectives provides a basis for selecting, piloting, and advocating use of particular VW platforms in specific educational contexts

Teaching and Learning Collaboratively and Virtually

In this paper we describe five knowledge areas for IS educational activities called for in the MSIS 2006 Model Curriculum. The knowledge areas are business processes, emerging technologies, globalization, human–computer interactions, and the impacts of digitization. We then describe two graduate-level courses which pursue these activities — each from a different perspective. One perspective focuses on students learning concepts about virtual teams and collaboration technologies. Another perspective centers on students finding, implementing, and evaluating virtual team and collaboration technologies. We describe the results of educational activities we embedded within these courses that purportedly helped students learn about the five knowledge areas. Next, we share feedback from students. We close the paper by encapsulating our lessons learned

Electrophoretic karyotypes and molecular genetic analysis of Tilletia caries and T. controversa

Electrophoretic karyotypes were obtained from intact cells of four wild type strains of Tilletia caries and T. controversa, and 5 inter specific hybrid progeny using clamped homogeneous electric field, pulsed field gel electrophoresis (CHEF PFGE). Each karyotype was polymorphic and unique relative to the other strains. However, the relative size range of all the chromosomes was consistent and typically ranged from approximately 850 to 4,490 kilobasepairs (Kb) for all strains, accept for two atypically small chromosomes in one strain of T. caries. The minimum estimated number of chromosomes was 19 or 20 for strains of T. controversa, 14 to 20 for T. caries, and from 19 to 22 for the hybrid progeny. The minimum estimated total genome size ranged from 28 to 39 megabasepairs (mb) for T. caries, 34 to 40 mb for T. controversa, and 36 to 42 mb for the hybrid progeny. Southern hybridization analysis performed with cloned, single copy homologous DNA fragments identified a single similar-sized chromosome in all strains. The maximum percent variability of the linkage groups defined by the single copy probes was 10% or less. The rDNA from Neurospora crassa hybridized with 2 or 3 chromosomes in the wild type stains of T. caries and T. controversa, and with 1 to 3 chromosomes in the hybrid progeny. The maximum percent variability among chromosomes that hybridized with the rDNA probe ranged from 35 to 40%. Either 1 or 2 chromosomes were identified by the single copy actin gene from Aspergillus nidulans, and the maximum percent variability ranged from 4 to 14% for these chromosomes. It was not possible to differentiate between the karyotypes of strains of either T. caries or T. controversa using the physical appearance of the karyotypes, the number and sizes of chromosomes, the genome sizes, or by Southern hybridization analysis. Analysis of the karyotypes of the hybrid progeny revealed that all were unique relative to each other and the parental stains, providing circumstantial evidence for the presence of recombinant chromosomes. That the genome size and chromosomes numbers of the hybrid progeny were similar to their monokaryotic parental strains strongly argues that the reduction division stage of meiosis had occurred. Seven teliospore samples from Oregon and Turkey were examined for their germination and autofluorescence properties. The teliospore samples were analyzed to determine if low temperature germination (0-4° C) and autofluorescing spore-wall reticulations associated with spores of T. controversa were usually linked. Two of the seven teliospore samples showed these characteristics to be unlinked. In an attempt to clone the mating type genes of T. caries and T. controversa, total genomic DNA was probed with a fragment of the b west mating type gene from Ustilago hordei. Although single 1.4 kb BamHI fragment from both pathogens was cloned by homology and sequenced, its role in mating type function remains uncertain

Effects of Corn Crop Residue Grazing on Soil Physical Properties and Subsequent Soybean Production in a Corn–Soybean Crop Rotation

For three years beginning in 1999, a 96-acre field near Atlantic, Iowa was used to study the effects of corn residue grazing by beef cows on soil characteristics and soybean yields in subsequent years. Each winter, cows were allowed to graze corn crop residues inside selected paddocks in four sub-fields over five monthly periods. To compare the effects of grazing, one paddock was left as an ungrazed control. At the end of grazing in the spring, soil bulk density, moisture content, and penetration resistance were measured inside and 15 ft outside twelve grazing exclosures in each paddock. Soil surface roughness, texture, and type were also measured in twelve locations in each paddock. Corn crop residues were collected for yield, cover, and composition at the initiation, middle and termination of grazing. Precipitation and soil temperature also were recorded throughout the grazing season. Each following year, soybeans were planted in replicated subfields with disking or no tillage and harvested using a combine equipped with a yield monitor and global positioning system (GPS). Cattle grazing corn crop residue has shown no effect on soil bulk density, but there has been a measurable effect on penetration resistance in paddocks grazed in October and November (P\u3c 0.05). There is an increase in soil surface roughness during certain periods of cattle grazing where 75% of the variation can be contributed to increase in the amount of time soil temperature is above freezing. Cattle grazing had no effect on soybean plant population. However, 36 and 38% of the variation in soybean yield can be attributed to penetration resistance and soil surface roughness

Spatial Frequency Analysis of Anisotropic Drug Transport in Tumor Samples

Directional Fourier spatial frequency analysis was used on standard histological sections to identify salient directional bias in the spatial frequencies of stromal and epithelial patterns within tumor tissue. This directional bias is shown to be correlated to the pathway of reduced fluorescent tracer transport. Optical images of tumor specimens contain a complex distribution of randomly oriented aperiodic features used for neoplastic grading that varies with tumor type, size, and morphology. The internal organization of these patterns in frequency space is shown to provide a precise fingerprint of the extracellular matrix complexity, which is well known to be related to the movement of drugs and nanoparticles into the parenchyma, thereby identifying the characteristic spatial frequencies of regions that inhibit drug transport. The innovative computational methodology and tissue validation techniques presented here provide a tool for future investigation of drug and particle transport in tumor tissues, and could potentially be used a priori to identify barriers to transport, and to analyze real-time monitoring of transport with respect to therapeutic intervention

Gut inflammation provides a respiratory electron acceptor for Salmonella.

Salmonella enterica serotype Typhimurium (S. Typhimurium) causes acute gut inflammation by using its virulence factors to invade the intestinal epithelium and survive in mucosal macrophages. The inflammatory response enhances the transmission success of S. Typhimurium by promoting its outgrowth in the gut lumen through unknown mechanisms. Here we show that reactive oxygen species generated during inflammation react with endogenous, luminal sulphur compounds (thiosulphate) to form a new respiratory electron acceptor, tetrathionate. The genes conferring the ability to use tetrathionate as an electron acceptor produce a growth advantage for S. Typhimurium over the competing microbiota in the lumen of the inflamed gut. We conclude that S. Typhimurium virulence factors induce host-driven production of a new electron acceptor that allows the pathogen to use respiration to compete with fermenting gut microbes. Thus the ability to trigger intestinal inflammation is crucial for the biology of this diarrhoeal pathogen

Paradoxical Roles of Tumour Necrosis Factor-Alpha in Prostate Cancer Biology

Tumour necrosis factor (TNF) is a pleiotropic cytokine with dual roles in cancer biology including prostate cancer (PCa). On the one hand, there is evidence that it stimulates tumour angiogenesis, is involved in the initiation of PCa from an androgen-dependent to a castrate resistant state, plays a role in epithelial to mesenchymal plasticity, and may contribute to the aberrant regulation of eicosanoid pathways. On the other hand, TNF has also been reported to inhibit neovascularisation, induce apoptosis of PCa cells, and stimulate antitumour immunity. Much of the confusion surrounding its seemingly paradoxical roles in cancer biology stems from the dependence of its effects on the biological model within which TNF is investigated. This paper will address some of these issues and also discuss the therapeutic implications

Winter grazing of corn residues: Effects on soil properties and subsequent crop yields from a corn-soybean crop rotation

Corn residues could be a good resource for winter cattle grazing. The study investigates whether winter grazing causes soil compaction and yield reduction in crops that are planted following grazing

Factors affecting farmers’ willingness to grow alternative biofuel feedstocks across Kansas

Energy conservation has emerged as one of the biggest challenges of the world in the XXI century, and not different from many countries, the US has created plans and policies to stimulate renewable energy alternative. Among the important alternatives for energy conservation is the use of biomass energy. Despite these stimuli production predictions are not confident that production would achieve the planned target for the U.S. Consequently, the predictions raise questions about farmer's willingness to grow bioenergy crops or produce alternative cellulosic feedstocks. In other words, farmers and landholders may not be willing to grow bioenergy crops. With this concerns in mind, the study advances previous research about bioenergy production by evaluating farmer's and landholder's willingness to produce different varieties of biofuel feedstocks. To achieve our goals, we used a mail survey of Kansas farmers conducted from January to April of 2011. The survey contained questions related to how farmers make their land-use decisions covering a wide array of topics. Through this survey, we evaluate the effect of farm characteristics, farm management practices, farmer perceptions (such as risk aversion), physical variables (such as soil, weather, and the availability of water for irrigation) on farmers' willingness to produce value-added feedstocks (e.g., corn stover), dedicated annual bioenergy crops (e.g., energy sorghum), and dedicated perennial bioenergy crops (e.g., switchgrass) for biofuel production in Kansas, though the use of logistic regressions and marginal effects