Digital game based learning: an exploratory analysis of perceived educational benefits at a junior high school level.

Masters Degree. University of KwaZulu-Natal, Durban.Digital Game Based Learning (DGBL) incorporates innovative tools that are widely recognized as having considerable potential to foster and support active learning, problem-solving and communication while providing an environment that embraces practice and learning through failure. The many proponents of DGBL believe that its use can provide a teaching approach that is relevant to the digital needs of the youth of today. Indeed, there are many studies that document the many benefits associated with DGBL for both teaching and learning. However, as was discovered in this study, there are many issues concerning the successful implementation and adoption of constructivist teaching technologies such as DGBL. Computer games can be expensive to purchase and difficult to personalise. Moreover, learners and educators alike; need to be convinced of their effectiveness before buying into their use. Furthermore, many educators simply do not have the time; or the expertise, to be able to effectively design and create games of their own. A problem exacerbated by the, perceived, high level of specialist expertise normally associated with game development. While there are many theorized benefits associated with DGBL there are as many issues concerning its successful implementation. The main purpose of this study was to investigate these theoretical benefits by addressing the following research questions: Can DGBL positively influence teaching and learning? And can DGBL positively influence learner perceptions of Information Technology (IT), with specific reference to coding? A survey was deployed after the implementation of an intervention within Grade 8 Computer Literacy classrooms. The instrument explored the perceptions and effectiveness of DGBL and served to inform the closed-ended questions used in the follow-up focus group interviews. To further support the data, educator interviews also took place post-intervention. The study found that DGBL did have a positive effect on both teaching and learning. Educator and learner views were either reinforced or changed in favour of a DGBL approach to teaching IT. The study recommended, further study into the academic and inter-disciplinary benefits of DGBL be conducted. The study also recommends the development of a set of guidelines on the use of DGBL as a means to support 21st century skills development in the classroom

EVALUATION OF A COUNTER-ROTATING ELECTRIC DUCTED FAN

The research and analysis presented in this study quantifies the benefits of a dual-stage counter-rotating electric ducted fan (EDF) that is optimized for high-speed operations. A thrust increase of 29% over a single rotor with the same frontal area was demonstrated. A custom thrust stand was developed to obtain these results and leave in place a capability to test future multi-stage EDF concepts. Commercial off-the-shelf components were modified to accommodate the proposed study. In addition, 3D scanning and reverse engineering techniques to create the necessary CAD models for computations studies were developed, which in turn allows for validation of the proposed EDF performance using three-dimensional fluid modeling software.Outstanding ThesisCivilian, Department of the NavyApproved for public release. Distribution is unlimited

Can Food-for-Work Programmes Reduce Vulnerability?

Famine, Food aid, Poverty, Public employment programmes, Transfers

Investigation and development of techniques for the characterisation of the synthetic/biological interface

The purpose of this study is to increase our knowledge of the nature of the surface properties of polymeric materials and improve our understanding of how these factors influence the deposition of proteins to form a reactive biological/synthetic interface. A number of surface analytical techniques were identified as being of potential benefit to this investigation and included in a multidisciplinary research program. Cell adhesion in culture was the primary biological sensor of surface properties, and it showed that the cell response to different materials can be modified by adhesion promoting protein layers: cell adhesion is a protein-mediated event. A range of surface rugosity can be produced on polystyrene, and the results presented here show that surface rugosity does not play a major role in determining a material's cell adhesiveness. Contact angle measurements showed that surface energy (specifically the polar fraction) is important in promoting cell spreading on surfaces. The immunogold labelling technique indicated that there were small, but noticeable differences, between the distribution of proteins on a range of surfaces. This study has shown that surface analysis techniques have different sensitivities in terms of detection limits and depth probed, and these are important in determining the usefulness of the information obtained. The techniques provide information on differing aspects of the biological/synthetic interface, and the consequence of this is that a range of techniques is needed in any full study of such a complex field as the biomaterials area

HETEROGENEOUS CONSTRAINTS, INCENTIVES AND INCOME DIVERSIFICATION STRATEGIES IN RURAL AFRICA

A burgeoning recent literature emphasizes "livelihood" diversification among smallholder populations (Chambers and Conway 1992, Davies 1993, Ellis 1998, Bryceson 1999, Ellis 2000, Little et al. 2001). While definitions vary within this literature, the concept of livelihoods revolves around the opportunity set afforded an individual or household by their asset endowment and their chosen allocation of those assets across various activities to generate a stream of benefits, most commonly measured as income. This holistic perspective has the potential to enhance our understanding of the strategies that farm households pursue to ensure food and income security given the natural and economic environment in which they operate. Diversification patterns reflect individuals' voluntary exchange of assets and their allocation of assets across various activities so as to achieve an optimal balance between expected returns and risk exposure conditional on the constraints they face (e.g., due to missing or incomplete markets for credit, labor, or land). Because it offers a glimpse as to what people presently consider their most attractive options, given the incentives and constraints they face, the study of diversification behavior offers important insights as to what policy or project interventions might effectively improve either the poor's asset holdings or their access to higher return or lower risk uses of the assets they already possess. Since diversification is not an end unto itself, it is essential to connect observed livelihood strategies back to resulting income distributions and poverty. Not all diversification into off-farm or non-farm income earning activities offers the same benefits and not all households have equal access to the more lucrative diversification options. Yet the livelihoods literature offers little documentation or explanation of important differences between observed diversification strategies. This paper addresses that gap by offering a comparative analysis using data from three different countries, Cote d'Ivoire, Kenya and Rwanda. Like Dercon and Krishnan (1996) and Omamo (1999), we emphasize that interhousehold heterogeneity in constraints and incentives must factor prominently in any sensible explanation of observed diversification behaviors. Indeed, section 4 demonstrates that at a very fundamental level - the choice of basic livelihood strategy - households would prefer locally available livelihood strategies other than those they choose, were they not constrained from doing so. A simple appeal to the principle of revealed preference thus suggests that heterogeneous constraints and incentives play a fundamental role in determining livelihood diversification patterns manifest in income diversification data. The plan for the remainder of this paper is as follows. The next section presents the basic conceptual foundation from which we operate. Section 3 then introduces the data sets and definitions employed in the analysis. Section 4 presents findings relating to the observed variation in income sources across the income distribution, to distinct livelihood strategies pursued by rural African households, to the determinants of strategy choice, and to the effects of alternative livelihood strategies on income dynamics. These findings point especially to significant rural markets failures - especially with respect to finance and land - that force poorer subpopulations to select strategies offering demonstrably lower returns while wealthier subpopulations are able to enjoy higher return strategies to which entry is at least partly impeded by fixed costs and lower marginal costs of participation. Section 5 concludes.Labor and Human Capital, O & Q12,

Intra-Annual Variability of Silver Carp Populations in the Des Moines River, USA

Since their introduction in the 1970s, Silver Carp Hypophthalmichthys molitrix have spread throughout the Mississippi River basin. Management of any species relies on an accurate understanding of population characteristics and dynamics. However, Silver Carp seasonal sampling variation is unknown. Sampling during periods of peak catch rates would facilitate Silver Carp assessment and management, improving monitoring and removal techniques. The objective of this study was to evaluate adult Silver Carp seasonal sampling variation with boat electroshocking and trammel nets. Silver Carp were collected monthly (April–October) during 2014 and 2015 from four locations in the Des Moines River, Iowa. Trammel nets rarely captured Silver Carp (mean ± SE = 4.9 ± 1.6 fish/net; 60% of fish were captured in 6.3% of net sets) and therefore were not included in analyses. Electroshocking catch rates (CPUEs) exhibited a bimodal distribution, with peak CPUEs generally occurring in May, June, and September and lower catch rates observed during July and August. Catch rates were positively related to river discharge at upstream sites but not at downstream sites. Silver Carp size structure was similar among months and sites except at Cliffland, where fish were smaller during August and October compared to earlier in the year. Finally, Silver Carp condition peaked during April and May and decreased throughout the year except at Keokuk, where peaks were observed during both May and August. Although spatiotemporal variability was substantial, these results suggest that sampling of Silver Carp via electroshocking in May–June and September–October generally produces higher catch rates compared to July–August sampling and generates a more representative size structure. Using site-specific knowledge, monitoring and surveillance programs could more effectively sample during these periods of high vulnerability and densities in order to manage the spread and impacts of Silver Carp at statewide and regionwide scales

A comparison of Grass Carp population characteristics upstream and downstream of Lock and Dam 19 of the Upper Mississippi River

Grass Carp Ctenopharyngodon idella have been intentionally stocked for aquatic vegetation control across the Midwestern United States for several decades. During the 1970s, escapement of Grass Carp into the Missouri River facilitated their naturalization into much of the Mississippi River basin, including the Upper Mississippi River. Lock and Dam 19 (LD19) in Keokuk, Iowa, is a high-head dam that represents a focal point for naturalized Grass Carp management where populations may differ between upstream and downstream pools as result of limited upstream migration, but potential differences between populations have yet to be evaluated to the best of our knowledge. The objective of this study was to compare the relative abundance, size structure, condition, growth, and recruitment variability of Grass Carp collected upstream and downstream of LD19. We sampled Grass Carp monthly (April–October) during 2014 and 2015 from four locations in the Des Moines River (downstream of LD19) and five locations throughout the Skunk, Iowa, and Cedar rivers (upstream of LD19) using boat electrofishing and trammel net sets. We captured 29 Grass Carp upstream of LD19 compared with 179 individuals captured downstream. Trammel nets only captured Grass Carp downstream of LD19; trammel net catch per unit effort upstream of LD19 was low and ranged from 0.0 to 8.0 fish/net lift (mean 6 SE¼0.39 6 0.13). Electrofishing catch per unit effort ranged from 0.0 to 22.7 fish/h (1.49 6 0.30) and was higher downstream (2.42 6 0.30) of LD19 than upstream (0.57 6 0.07). Grass Carp downstream of LD19 tended to be smaller, younger, of lower body condition, had higher mortality rates, and were slower growing compared with those collected upstream and to populations documented in other systems. Understanding and monitoring adult Grass Carp population characteristics upstream and downstream of LD19 is necessary to determine how they may change in response to ongoing harvest efforts for invasive carps in these river reaches

Can food-for-work programmes reduce vulnerability?

Food-for-work (FFW) programmes have been widely heralded as a means of providing self-targeting transfers coupled with investment in public goods. This paper reviews the changing context that has sparked such interest in FFW, the simple theory that makes it so conceptually appealing, and conceptual problems with that simple theory, all illustrated with empirical examples, primarily from east Africa. We conclude with an attempt at distilling some useful rules of thumb as to when, how and why FFW can serve effectively as short-term insurance, a longer-term rehabilitation and development intervention, or both. – famine ; food aid ; poverty ; public employment programmes ; transfer