Finance in Africa - Achievements and Challenges

In spite of shallow financial markets, Sub-Saharan Africa will not escape the repercussions of the global financial crisis. The global turmoil threatens the progress Sub-Saharan Africa has made in financial sector deepening and broadening over the recent years and underlines the importance of continuing and deepening the necessary institutional reforms. In this context it is important to define the role of government in expanding financial sectors in a sustainable and market-friendly manner. Foreign banks have brought more benefits than risks for their host economies in Sub-Saharan Africa, but are certainly not a panacea and not a substitute for institutional and policy reform. The profile of foreign banks, however, has changed, with more and more regional banks emerging. This trend toward regional integration is promising as it might allow the small African financial system to reap benefits from scale economies, but it also requires regulatory and supervisory improvements and coordination across the region.Banks&Banking Reform,Debt Markets,Access to Finance,,Emerging Markets

Venezuela's National Music Education Program El Sistema: Its Interactions with Society and Its Participants' Engagement in Praxis

Venezuela's government-funded, national music education program, El Sistema, has attracted worldwide attention because of its purported success in ‘saving’ children from lives filled with drugs, violence, and crime. It does this by giving them the opportunity to play in an after-school orchestra, one to four hours a day, five to six days a week. This article describes the program’s organizational philosophy and mission, and accounts for its day-to-day activities in order to explore how these programmatic aspects may positively contribute to participant engagement in Paulo Freire’s notion of praxis, that is, “reflection and action upon the world in order to transform it” (Freire and Ramos, 2004, p. 51). Additionally, other programmatic aspects of El Sistema are highlighted to help link the program with previous research on improving students’ social behavior and cognitive development. Finally, the article discusses some of the program’s strengths and weaknesses and how it plays a role in Venezuelan society, interacting not only with the community of students and parents, but also with national and local governments and the private business sector. In doing so, El Sistema is contextualized within its social environment and conclusions are drawn on the potential for success and replicability in other cities and countries

A combined finite element–finite volume framework for phase-field fracture

Numerical simulations of brittle fracture using phase-field approaches often employ a discrete approximation framework that applies the same order of interpolation for the displacement and phase-field variables. In particular, the use of linear finite elements to discretize both stress equilibrium and phase-field equations is widespread in the literature. However, the use of Lagrange shape functions to model the phase-field is not optimal, as the latter contains cusps for fully developed cracks. These should in turn occur at locations corresponding to Gauss points of the associated FE model for the mechanics. Such a feature is challenging to reproduce accurately with low order elements, and element sizes must consequently be made very small relative to the phase-field regularization parameter in order to achieve convergence of results with respect to the mesh. In this paper, we combine a standard linear FE discretization of stress equilibrium with a cell-centered finite volume approximation of the phase-field evolution equation based on the two-point flux approximation constructed over the same simplex mesh. Compared to a pure FE formulation utilizing linear elements, the proposed framework results in looser restrictions on mesh refinement with respect to the phase-field length scale. This ability to employ coarser meshes relative to the traditional implementation allows for significant reductions on computational cost, as demonstrated in several numerical examples.publishedVersio

Semantically-based crossover in genetic programming: application to real-valued symbolic regression

We investigate the effects of semantically-based crossover operators in genetic programming, applied to real-valued symbolic regression problems. We propose two new relations derived from the semantic distance between subtrees, known as semantic equivalence and semantic similarity. These relations are used to guide variants of the crossover operator, resulting in two new crossover operators—semantics aware crossover (SAC) and semantic similarity-based crossover (SSC). SAC, was introduced and previously studied, is added here for the purpose of comparison and analysis. SSC extends SAC by more closely controlling the semantic distance between subtrees to which crossover may be applied. The new operators were tested on some real-valued symbolic regression problems and compared with standard crossover (SC), context aware crossover (CAC), Soft Brood Selection (SBS), and No Same Mate (NSM) selection. The experimental results show on the problems examined that, with computational effort measured by the number of function node evaluations, only SSC and SBS were significantly better than SC, and SSC was often better than SBS. Further experiments were also conducted to analyse the perfomance sensitivity to the parameter settings for SSC. This analysis leads to a conclusion that SSC is more constructive and has higher locality than SAC, NSM and SC; we believe these are the main reasons for the improved performance of SSC

An accelerated staggered scheme for variational phase-field models of brittle fracture

There is currently an increasing interest in developing efficient solvers for variational phase-field models of brittle fracture. The governing equations for this problem originate from a constrained minimization of a non-convex energy functional, and the most commonly used solver is a staggered solution scheme. This is known to be robust compared to the monolithic Newton method, however, the staggered scheme often requires many iterations to converge when cracks are evolving. The focus of our work is to accelerate the solver through a scheme that sequentially applies Anderson acceleration and over-relaxation, switching back and forth depending on the residual evolution, and thereby ensuring a decreasing tendency. The resulting scheme takes advantage of the complementary strengths of Anderson acceleration and over-relaxation to make a robust and accelerating method for this problem. The new method is applied as a post-processing technique to the increments of the solver. Hence, the implementation merely requires minor modifications to already available software. Moreover, the cost of the acceleration scheme is negligible. The robustness and efficiency of the method are demonstrated through numerical examples.publishedVersio

Geography of hospital admissions for multiple sclerosis in England and comparison with the geography of hospital admissions for infectious mononucleosis: a descriptive study

Objective It is well recognised that variation in the geographical distribution of multiple sclerosis (MS) exists. Early studies in England have shown the disease to have been more common in the North than the South. However, this could be an artefact of inaccurate diagnosis and ascertainment, and recent data on MS prevalence are lacking. In the present study, data were analysed to provide a more contemporary map of the distribution of MS in England and, as infectious mononucleosis (IM) has been shown to be associated with the risk of MS, the geographical distribution of IM with that of MS was compared.Methods Analysis of linked statistical abstracts of hospital data for England between 1999 and 2005.Results There were 56 681 MS patients. The admission rate for MS was higher in females (22/10(5); 95% CI 21.8 to 22.3) than males (10.4/10(5); 95% CI 10.2 to 10.5). The highest admission rate for MS was seen for residents of Cumbria and Lancashire (North of England) (20.1/10(5); 95% CI 19.3 to 20.8) and the lowest admission rate was for North West London residents (South of England) (12.4/10(5); 95% CI 11.8 to 13.1). The geographical distributions of IM and MS were significantly correlated (weighted regression coefficient (r (w))=0.70, p<0.0001). Admission rates for MS were lowest in the area quintile with the highest level of deprivation and they were also lowest in the area quintile with the highest percentage of population born outside the UK. A significant association between northernliness and MS remained after adjustment for deprivation and UK birthplace.Conclusions The results show the continued existence of a latitude gradient for MS in England and show a correlation with the distribution of IM. The data have implications for healthcare provision, because lifetime costs of MS exceed 1 pound million per case in the UK, as well as for studies of disease causality and prevention

Improved results of induction chemoradiation before surgical intervention for selected patients with stage IIIA-N2 non–small cell lung cancer

ObjectiveOptimal management of stage IIIA-N2 non–small cell lung cancer remains controversial. The surgical arm of the North American Intergroup 0139 trial was adopted as the standard treatment for patients with resectable N2 disease at the University Health Network. Results after 7 years of experience are reported.MethodsThis is a retrospective study of consecutive patients with biopsy-proved T1-3 N2 M0 lung cancer who underwent induction chemoradiation before surgical intervention from January 1997 through August 2004. Induction chemotherapy consisted of cisplatin, 50 mg/m2, on days 1 and 8; etoposide, 50 mg/m2, on days 1 to 5, weeks 1 and 5; and concurrent daily external beam radiotherapy to 45 Gy. Lung resection was performed within 6 weeks of completion of chemoradiation, followed by 2 further cycles of consolidation chemotherapy.ResultsBetween January 1997 and August 2004, 40 patients were treated according to this protocol (25% T1, 62.5% T2, 7.5% T3, and 5% T4). Overall and disease-free median survivals were 40 and 37.1 months, respectively, whereas overall and disease-free 3-year survivals were 51.7% and 52.3%, respectively. R0 resection was achieved in 92.5%. The overall operative mortality rate was 7.5% (0% for lobectomy and 27% for pneumonectomy). Notably, all mortalities occurred within the first 2 years of our experience with this regimen.ConclusionChemoradiation before pulmonary resection in carefully selected patients with surgically resectable stage IIIA (N2) non–small cell lung cancer can lead to improved overall and disease-free survival

Machine learning-based scoring models to predict hematopoietic stem cell mobilization in allogeneic donors

Mobilized peripheral blood has become the primary source of hematopoietic stem cells for both autologous and allogeneic stem cell transplantation. Granulocyte colony-stimulating factor (G-CSF) is currently the standard agent used in the allogeneic setting. Despite the high mobilization efficacy in most donors, G-CSF requires 4-5 days of daily administration, and a small percentage of the donors fail to mobilize an optimal number of stem cells necessary for a safe allogeneic stem cell transplant. In this study, we retrospectively reviewed 1361 related allogeneic donors who underwent stem cell mobilization at Washington University. We compared the standard mobilization agent G-CSF with five alternative mobilization regimens, including GM-CSF, G-CSF+GM-CSF, GM-CSF + Plerixafor, Plerixafor and BL-8040. Cytokine-based mobilization strategies (G-CSF or in combination with GM-CSF) induce higher CD34 cell yield after 4-5 consecutive days of treatment, while CXCR4 antagonists (plerixafor and BL-8040) induce significantly less but rapid mobilization on the same day. Next, using a large dataset containing the demographic and baseline laboratory data from G-CSF-mobilized donors, we established machine learning (ML)-based scoring models that can be used to predict patients who may have less than optimal stem cell yields after a single leukapheresis session. To our knowledge, this is the first prediction model at the early donor screening stage, which may help identify allogeneic stem cell donors who may benefit from alternative approaches to enhance stem cell yields, thus ensuring safe and effective stem cell transplantation