Anti-angiogenic activity of Entada africana root

Entada africana roots are used in African traditional medicine for various diseases including inflammation. This application may be mediated through anti-angiogenic effects. Thus, in this study the anti-angiogenic activity of E. africana root extracts (n-hexane, chloroform, chloroform/methanol and methanol) was preliminarily evaluated by the quantitative determination of endogenous alkaline phosphatase in zebrafish embryos. A bioactivity-guided fractionation of chloroform/methanol extract yielded apigenin and robinetin as the main constituents from the most active fractions. In addition, a marked reduction on capillary formation was evidenced in chick chorioallantoic membrane after treatment with the active fractions or isolated compounds. Results obtained in this study suggest that the anti-angiogenic effects of E. africana root may account for its use in inflammatory diseases and other related pathological conditions.     

Existence Results for Some Partial Integro-Differential Equations

In this note, we deal with semilinear integro-differential equations subject to homogeneous Dirichlet boundary conditions given on the boundaries of the sections. Even if the differentiation will be taken only in some directions, it is not possible to see the main problem parameterized by the other coordinates because of the non-local terms which also obliged the problem to be degenerate. We establish the existence of solutions by employing the singular perturbations method as a natural tool. The perturbed problems are classical, non-local, semilinear elliptic problems and the limits of the subsequences of their solutions, in weighted Sobolev type spaces, are solutions of the main problem. Some improvement, concerning the existence of the solutions and the convergence results depending on the weights, will be established. The paper also gives an idea about the study of the anisotropic singular perturbations in the framework of weighted spaces.     

Effects of Kigelia africana (Lam.) Benth. fruits extract on the development and maturation of the reproductive system in immature male rats

Abstract

In the present study, we investigated the effects of Kigelia africana (Lam.) Benth. fruits ethanolic extract in prepubertal male rats, to evaluate the influence of the extract on the reproductive system and on pubertal development. Experiments were conducted using the rodent pubertal male assay. The plant extract, analyzed by TLC, HPLC-PDA and HPLC-ESI-MS, was administered orally at doses of 200, 400 and 800?mg/kg b.w. from post-natal date 21 to post-natal day 53. Age at puberty onset, body growth, development of sexual organs exposure to plant extract or positive control were examined. Results obtained indicate that Kigelia extract, at all doses tested, significantly anticipates puberty and increases body growth and sexual organs development. These effects appears to be due to stimulation of the secretion of androgenic hormones by the compounds found in its extract and scientifically support some of its traditional uses in disorders of the male reproductive system.     

A framework for incremental generation of closed itemsets

Association rule mining from a transaction database (TDB) requires the detection of frequently occurring patterns, called frequent itemsets (FIs), whereby the number of FIs may be potentially huge. Recent approaches for FI mining use the closed itemset paradigm to limit the mining effort to a subset of the entire FI family, the frequent closed itemsets (FCIs). We show here how FCIs can be mined incrementally yet efficiently whenever a new transaction is added to a database whose mining results are available. Our approach for mining FIs in dynamic databases relies on recent results about lattice incremental restructuring and lattice construction. The fundamentals of the incremental FCI mining task are discussed and its reduction to the problem of lattice update, via the CI family, is made explicit. The related structural results underlie two algorithms for updating the set of FCIs of a given TDB upon the insertion of a new transaction. A straightforward method searches for necessary completions throughout the entire CI family, whereas a second method exploits lattice properties to limit the search to CIs which share at least one item with the new transaction. Efficient implementations of the parsimonious method is discussed in the paper together with a set of results from a preliminary study of the method's practical performances.     

Design of space thrusters: a topology optimization problem solved via a Branch and Bound method

In this paper, an exact Branch and Bound Algorithm has been developed to solve a difficult global optimization problem concerning the design of space thrusters. This optimization problem is hard to solve mainly because the objective function to be minimized is implicit and must be computed by using a Finite Element method code. In a previous paper, we implement a method based on local search algorithms and we then proved that this problem is non convex yielding a strong dependency between the obtained local solution and the starting points. In this paper, by taking into account a monotonicity hypothesis that we validated numerically, we provide properties making it possible the computation of bounds. This yields the development of a topology optimization Branch and Bound code. Some numerical examples show the efficiency of this new approach.     

Kinks in the STEM Pipeline: Tracking STEM Graduation Rates Using Science and Mathematics Performance

In an effort to maintain the global competitiveness of the United States, ensuring a strong Science, Technology, Engineering and Mathematics (STEM) workforce is essential. The purpose of this study was to identify high school courses that serve as predictors of success in college level gatekeeper courses, which in turn led to the successful completion of STEM degrees. Using a purposive sample of 893 students who had declared a STEM major between the fall of 2006 and the spring of 2008, data were collected on students' high school grades, college grades, national test scores, grade point average, gender, and ethnicity. Using analysis of variance, correlations, multiple discriminant function analysis, and multiple regression models we found that high school calculus, physics, and chemistry (respectively) were predictors of success in STEM gatekeeper college courses. Then using those courses, we constructed a predictive model of STEM degree completion. The implications of this study highlight and reinforce the importance of providing rigorous mathematics and science courses at the high school level, as well as provide some evidence of a potential mediated model of the relationship between high school performance, college performance, and graduating with a STEM degree.