Bifurcation of Localized Disturbances in a Model Biochemical Reaction

Asymptotic solutions are presented to the nonlinear parabolic reaction-diffusion equations describing a model biochemical reaction proposed by I. Prigogine. There is a uniform steady state which, for certain values of the adjustable parameters, may be unstable. When the uniform solution is slightly unstable, the two-timing method is used to find the bifurcation of new solutions of small amplitude. These may be either nonuniform steady states or time-periodic solutions, depending on the ratio of the diffusion coefficients. When one of the parameters is allowed to depend on space and the basic state is unstable, it is found that the nonuniform steady state which is approached may show localized spatial oscillations. The localization arises out of the presence of turning points in the linearized stability equations

IMPACT OF NO-TILL TECHNOLOGIES IN GHANA

In the 1990s, no-till with mulch, a sustainable agricultural alternative, was introduced to Ghanaian farmers through a joint program between the Crops Research Institute in Kusami, Ghana, Sasakawa Global 2000, and the Monsanto Company. The package was disseminated to farmers in the Forest, Transition, and Guinea Savannah Zones, and rapidly adopted. In 2000, it was estimated that 100,000 small-scale farmers practiced no-till on 45,000 hectares of land. This study examines the impact of no-till on farmers who adopted the technology in the three zones, and to a lesser extent, the reasons for non-adoption. The impact of no-till among agrochemical dealers was also evaluated. The report found that no-till brought important changes to farmers using the technology and expanded the market for agrochemicals. It calls for more research on machinery for the technology, crop rotations, and the dynamics of diseases and weed and pest populations. More research on the organization and performance of agrochemical markets is also needed to identify bottlenecks that hamper the dissemination of no-till.Farm Management,

Ecommerce in virtual worlds : a ‘just do it’ approach?

For the corporate world, virtual worlds (VWs) are still an unexplored land of opportunities. The fact that some big companies such as IBM and Sun Microsystems have devoted considerable funds and talent to taming the new territory has convinced others to step in. However and by the same token, the spectacular falls of some of these VWs ‘projects’ made other corporations hesitant or at least lukewarm about developing their own VW presence agenda

Electronic swallowing intervention package to support swallowing function in patients with head and neck cancer: development and feasibility study

Background: Many patients undergoing treatment for head and neck cancer (HNC) experience significant swallowing difficulties, and there is some evidence that swallowing exercises may improve outcomes, including quality of life. This feasibility study developed an evidence-based, practical Swallowing Intervention Package (SiP) for patients undergoing chemo-radiotherapy (CRT) for HNC. As part of the study, an electronic version of SiP (e-SiP) was concurrently developed to support patients to self-manage during treatment. This paper reports on the e-SiP component of this work. Objective: To develop and conduct preliminary evaluation of an electronic support system (e-SiP) for patients undergoing CRT for head and neck cancer. Methods: The study involved health professionals and patients who were undergoing CRT for head and neck cancer. The scoping stage of e-SiP development involved investigated the potential usefulness of e-SiP, exploring how e-SiP would look and feel and what content would be appropriate to provide. Patient and carer focus groups and a health professionals’ consensus day were used as a means of data gathering around potential e-SiP content. A repeat focus group looked at an outline version of e-SIP and informed the next stage of its development around requirements for tool. This was followed by further development and a testing stage of e-SiP involved the coding of a prototype which was then evaluated using a series of steering group meetings, semi-structured interviews with both patients and health care professionals, and analysis of e-SiP log data. Results: Feedback from focus groups and health professional interviews was very positive and it was felt e-SiP use would support and encourage patients in conducting their swallowing exercises. However, of the ten patients offered e-SIP, only two opted to use it. For these patients, aspects of the e-SIP application were considered useful, in particular the ease of keeping a diary of exercises performed. Interviews with users and non-users suggested significant barriers to its use. Most significantly the lack of flexibility of platform on which e-SiP could be accessed appeared a dominant factor in deterring e-SiP use. Conclusions: Results suggest a need for further research to be conducted around the implementation of e-SiP. This involves evaluating how e-SiP can be better integrated into usual care, and through patient training and staff engagement, can be seen as a beneficial tool to help support patients in conducting swallowing exercises