Solving Polynomial Systems via a Stabilized Representation of Quotient Algebras

We consider the problem of finding the isolated common roots of a set of polynomial functions defining a zero-dimensional ideal I in a ring R of polynomials over C. We propose a general algebraic framework to find the solutions and to compute the structure of the quotient ring R/I from the null space of a Macaulay-type matrix. The affine dense, affine sparse, homogeneous and multi-homogeneous cases are treated. In the presented framework, the concept of a border basis is generalized by relaxing the conditions on the set of basis elements. This allows for algorithms to adapt the choice of basis in order to enhance the numerical stability. We present such an algorithm and show numerical results

Understanding interface effects in perovskite thin films

The control of matter properties (transport, magnetic, dielectric,...) using synthesis as thin films is strongly hindered by the lack of reliable theories, able to guide the design of new systems, through the understanding of the interface effects and of the way the substrate constraints are imposed to the material. The present paper analyses the energetic contributions at the interfaces, and proposes a model describing the microscopic mechanisms governing the interactions at an epitaxial interface between a manganite and another transition metal oxide in perovskite structure (as for instance $\rm SrTiO_3$). The model is checked against experimental results and literature analysis

FITCA-EMMC workshops on information exchange and training with rural communities on environment: Eastern Uganda. W1

Four workshops were held in four sub counties in the districts of Soroti, Tororo, Iganga and Kamuli. Five to seven villages were involved in each sub county. Participatory approach was used to gather the farmers' perception on four environmental themes; Forests and woodlands, wetlands and water, land and soils and livestock and wildlife. The main issues that have caused changes in each theme were: deforestation; cultivation of wetlands and drying up of swamps; land degradation and low productivity; livestock diseases and habitat destruction. 5 The communities related the changes to their effects on human livelihood and incidences of sleeping sickness and Nagana. Majority of these changes have had negative impacts on livelihood, thus making the communities poorer than before. Loss of habitat due to over exploitation of forests and cultivation of wetlands have affected tsetse ecolo gy and resulted in sleeping sickness and Nagana. The activities being undertaken by FITCA in reclaiming tsetse infested areas and making them available for agricultural activities are short term benefits whereas land degradation and the resultant cycle of poverty are the long term outcomes, unless steps are taken now to address the expected land use changes and the land carrying capacity. In this regard the initiative to encourage zero grazing and pasture development may help to address the problem of land degradation. The communities developed a suite of recommendations and indicators for each theme. It is important that follow up meetings be done to see the development of action plans at village level to implement these recommendations in order to arrest the downward spiral of the environment. Involvement of communities in monitoring, management and conservation is important in order to have a sustained conservation effort, as these communities are the ones bearing the full impacts of the changes that have taken place in the environment. (Résumé d’auteur

Injection of vacancies at metal grain boundaries during the oxidation of nickel

Nickel foils have been oxidised at 1000 °C on one side only in laboratory air, the other side being protected from oxidation by a reducing atmosphere. After the oxidation treatment, the unoxidised face was carefully examined by using an atomic force microscope. Grain boundaries grooves were characterised and their depth were compared to the ones obtained on the same sample heat treated in the reducing atmosphere during the same time. Grain boundaries grooves are found to be much deeper in the case of the single side oxidised samples. It is shown that this additional grooving is directly linked to the growth of the oxide scale on the opposite side and that it can be explained by the diffusion of the vacancies produced at the oxide scale–metal interface, across the entire sample through grain boundaries. Moreover, the comparison between single side oxidised samples and samples oxidised on both sides points out that voids in grain boundaries are only observed in this latter case proving the vacancies condensation in the metal when the two faces are oxidised

Dissimilarity-based representation for radiomics applications

Radiomics is a term which refers to the analysis of the large amount of quantitative tumor features extracted from medical images to find useful predictive, diagnostic or prognostic information. Many recent studies have proved that radiomics can offer a lot of useful information that physicians cannot extract from the medical images and can be associated with other information like gene or protein data. However, most of the classification studies in radiomics report the use of feature selection methods without identifying the machine learning challenges behind radiomics. In this paper, we first show that the radiomics problem should be viewed as an high dimensional, low sample size, multi view learning problem, then we compare different solutions proposed in multi view learning for classifying radiomics data. Our experiments, conducted on several real world multi view datasets, show that the intermediate integration methods work significantly better than filter and embedded feature selection methods commonly used in radiomics.Comment: conference, 6 pages, 2 figure

International cooperation and the reform of public procurement policies

The decision not to launch negotiations in the World Trade Organization (WTO) on three of the Singapore Issues in the so-called July 2004 package provides an opportunity to revisit the knowledge base on which proposals for further international collective action may be drawn. This paper examines the available evidence on public procurement practices in developing countries that could be relevant to further multilateral rule making on state purchasing. Although there is considerable agreement on ends (efficient, non-corrupt, and transparent public purchasing systems), little information is available on means and, in particular, on the effective and replicable strategies that developing countries can adopt to improve their public procurement systems. A concerted effort to substantially add to the knowledge base on public procurement reforms in developing countries, through targeted research and international exchange of information on implemented procurement policies and outcomes, is critical to identifying areas where further binding multilateral disciplines may be beneficial.Government Procurement,Corruption&Anitcorruption Law,Public Sector Corruption&Anticorruption Measures,Pharmaceuticals&Pharmacoeconomics,Business in Development

Kenya research situation analysis on orphans and other vulnerable children

This item is archived in the repository for materials published for the USAID supported Orphans and Vulnerable Children Comprehensive Action Research Project (OVC-CARE) at the Boston University Center for Global Health and Development.Addressing the needs of orphans and vulnerable children (OVC) and mitigating negative outcomes of the growing OVC population worldwide is a high priority for national governments and international stakeholders that recognize this as an issue with social, economic, and human rights dimensions. Assembling the relevant available data on OVC in one place, and acknowledging the gaps that still exist in our knowledge, will assist policy makers and program implementers to make evidence-based decisions about how best to direct funding and program activities and maximize positive outcomes for children and their caretakers. This Research Situation Analysis, Kenya Country Brief, presents a program-focused summary of available information on: • The number of orphans and vulnerable children in Kenya. • Current policies, programs and interventions designed and implemented to assist them. • Gaps in these policies, programs and interventions. • OVC research conducted between 2004 and 2008. • Gaps in the Kenyan OVC evidence base.The Brief analyzes the available data for critical gaps in the national response and our understanding about whether current interventions are fulfilling the needs and improving the lives of vulnerable children. The report then recommends actions required to increase the knowledge base for improving the effectiveness and impact of OVC programs.The USAID | Project SEARCH, Orphans and Vulnerable Children Comprehensive Action Research (OVC-CARE) Task Order, is funded by the U.S. Agency for International Development under Contract No. GHH-I-00-07-00023-00, beginning August 1, 2008. OVC-CARE Task Order is implemented by Boston University. The opinions expressed herein are those of the authors and do not necessarily reflect the views of the funding agency