The Riddle of Gravitation

There is no doubt that both the special and general theories of relativity capture the imagination. The anti-intuitive properties of the special theory of relativity and its deep philosophical implications, the bizzare and dazzling predictions of the general theory of relativity: the curvature of spacetime, the exotic characteristics of black holes, the bewildering prospects of gravitational waves, the discovery of astronomical objects as quasers and pulsers, the expansion and the (possible) recontraction of the universe..., are all breathtaking phenomena. In this paper, we give a philosophical non-technical treatment of both the special and the general theory of relativity together with an exposition of some of the latest physical theories. We then give an outline of an axiomatic approach to relativity theories due to Andreka and Nemeti that throws light on the logical structure of both theories. This is followed by an exposition of some of the bewildering results established by Andreka and Nemeti concerning the foundations of mathematics using the notion of relativistic computers. We next give a survey on the meaning and philosophical implications of the the quantum theory and end the paper by an imaginary debate between Einstein and Neils Bohr reflecting both Einstein's and Bohr's philosophical views on the quantum world. The paper is written in a somewhat untraditional manner; there are too many footnotes. In order not to burden the reader with all the details, we have collected the more advanced material the footnotes. We think that this makes the paper easier to read and simpler to follow. The paper in full is adressed more to experts.Comment: 40 pages, LaTeX-fil

An Efficient Automatic Mass Classification Method In Digitized Mammograms Using Artificial Neural Network

In this paper we present an efficient computer aided mass classification method in digitized mammograms using Artificial Neural Network (ANN), which performs benign-malignant classification on region of interest (ROI) that contains mass. One of the major mammographic characteristics for mass classification is texture. ANN exploits this important factor to classify the mass into benign or malignant. The statistical textural features used in characterizing the masses are mean, standard deviation, entropy, skewness, kurtosis and uniformity. The main aim of the method is to increase the effectiveness and efficiency of the classification process in an objective manner to reduce the numbers of false-positive of malignancies. Three layers artificial neural network (ANN) with seven features was proposed for classifying the marked regions into benign and malignant and 90.91% sensitivity and 83.87% specificity is achieved that is very much promising compare to the radiologist's sensitivity 75%.Comment: 13 pages, 10 figure

TRAINING COURSE ON DELIVERY CARE AND NEONATAL CARE IN RURAL HOSPITALS, GEZIRA STATE, SUDAN

This paper describes a training course for medical officers working in the rural hospitals in Gezira State to achieve a general objective; safe management of obstetric emergencies, miscarriage and the newborn . the description of the course includes; an introduction, the specific learning objectives, a detailed plan of work, instructional methods, resources , the course timetable, evaluation methods, description of the logbook and the feedback questionnaire. This article also includes descriptions of our experience in three rounds during which 43 medical officesr were traine

Monte-Carlo methods for the pricing of American options: a semilinear BSDE point of view

We extend the viscosity solution characterization proved in [5] for call/put American option prices to the case of a general payoff function in a multi-dimensional setting: the price satisfies a semilinear re-action/diffusion type equation. Based on this, we propose two new numerical schemes inspired by the branching processes based algorithm of [8]. Our numerical experiments show that approximating the discontinu-ous driver of the associated reaction/diffusion PDE by local polynomials is not efficient, while a simple randomization procedure provides very good results

Buckling Analysis of CNTRC Curved Sandwich Nanobeams in Thermal Environment

none6siThis paper presents a mathematical continuum model to investigate the static stability buckling of cross-ply single-walled (SW) carbon nanotube reinforced composite (CNTRC) curved sandwich nanobeams in thermal environment, based on a novel quasi-3D higher-order shear deformation theory. The study considers possible nano-scale size effects in agreement with a nonlocal strain gradient theory, including a higher-order nonlocal parameter (material scale) and gradient length scale (size scale), to account for size-dependent properties. Several types of reinforcement material distributions are assumed, namely a uniform distribution (UD) as well as X- and O- functionally graded (FG) distributions. The material properties are also assumed to be temperature-dependent in agreement with the Touloukian principle. The problem is solved in closed form by applying the Galerkin method, where a numerical study is performed systematically to validate the proposed model, and check for the effects of several factors on the buckling response of CNTRC curved sandwich nanobeams, including the reinforcement material distributions, boundary conditions, length scale and nonlocal parameters, together with some geometry properties, such as the opening angle and slenderness ratio. The proposed model is verified to be an effective theoretical tool to treat the thermal buckling response of curved CNTRC sandwich nanobeams, ranging from macroscale to nanoscale, whose examples could be of great interest for the design of many nanostructural components in different engineering applications.openAhmed Amine Daikh; Mohammed Sid Ahmed Houari; Behrouz Karami; Mohamed A. Eltaher; Rossana Dimitri; Francesco TornabeneAmine Daikh, Ahmed; Sid Ahmed Houari, Mohammed; Karami, Behrouz; Eltaher, Mohamed A.; Dimitri, Rossana; Tornabene, Francesc

Possible alternative for national supply of seed potatoes (Solanum tuberosum L.) from in vitro culture at the Agro-physio-genetic and Plants Biotechnology laboratory of IPR / IFRA of Katibougou, Mali

The enhancement of the potential for reducing food insecurity and poverty through potato cultivation in Mali is largely limited by difficult access to quality seed. In trying to find ways to reduce these shortcomings outlined above that work has been done. The objective of this work was to assess the economic profitability of the local potato seed sourcing scheme from in vitro propagation and to analyze the competitiveness of the sourcing scheme from imported elite seed. The technical and economic feasibility of the local potato seed supply scheme was assessed at five levels. The first concerns the production of vitro-plants in the laboratory, the second the production of mini zero generation tubers (G0). Regarding the other three levels of evaluation, they were carried out in collaboration with the seed cooperatives by successive multiplication from mini-tubers to obtain seeds of one “G1”, two “G2” and three “G3” generations". The profitability of the procurement scheme from the elite imported and multiplied once seed was evaluated in order to analyze its competitiveness in relation to the local circuit. The valuation indicates positive profit margins. However, it should be noted that the economic efficiency coefficients of vitro-propagation (0.77) and tunnel multiplication (0.75) are less than 1. The production cost of one kilogram of G3 is equal to at 463.39 F CFA. A profit margin of 456.61 F CFA / kg emerges between this unit production cost and the selling price of imported seeds, which amounts on average to 920 F CFA / kg. The production of plants is technically feasible and profitable with a cost price of one kg of G3 in the order of 500 to 600 F CFA against 900 to 1000 F CFA / kg for imported seed. La valorisation du potentiel de réduction de l’insécurité alimentaire et de la pauvreté à travers la culture de la pomme de terre au Mali est limitée en grande partie par l’accès difficile à la semence de qualité. En essayant de trouver des moyens pour réduire ces insuffisances soulignées ci-dessus que ce travail a été effectué. Le présent travail avait pour objectif d’évaluer la rentabilité économique du schéma d’approvisionnement locale en semences de pomme de terre à partir de la vitro propagation et d’analyser la compétitivité du schéma d’approvisionnement à partir de la semence élite importées. La faisabilité technico-économique du schéma d’approvisionnement local en semences de pomme de terre était évaluée à cinq niveaux. Le premier concerne la production de vitro-plants au laboratoire, le deuxième la production de mini tubercules de génération zéro (G0). Pour ce qui concerne les trois autres niveaux d’évaluation, ils ont été réalisés en collaboration avec les coopératives semencières par multiplications successives à partir de mini-tubercules pour obtenir des semences de génération une «G1», deux «G2» et trois «G3». La rentabilité, du schéma d’approvisionnement à partir de la semence élite importée et multipliée une fois, a été évaluée en vue d’analyser sa compétitivité en rapport avec le circuit local. L’évaluation indique des marges bénéficiaires positives. Cependant, il faut remarquer que les coefficients d’efficacité économiques de la vitro-propagation (0,77) et de la multiplication sous tunnels (0,75) sont inférieurs à 1. Le coût de production d’un kilogramme de G3 est égal à 463,39 F CFA. Une marge bénéficiaire de 456,61 F CFA / kg se dégage entre ce coût de production unitaire et le prix de vente des semences importées qui s’élève en moyenne à 920 F CFA / kg. La production de plants est techniquement faisable et rentable avec un coût de revient d’un kg de G3 de l’ordre de 500 à 600 F CFA contre 900 à 1 000 F CFA / kg pour la semence importée

SUCCESSFUL TWO PREGNANCIES IN ACHONDROPLASIC MOTHER, A CASE REPORT

The word achondroplasia is derived from Greek and means "without cartilage formation," although individuals with achondroplasia do have cartilage. In genetics, dominance describes the effects of the different versions of a particular gene on the phenotype of an organism. Many animals (including humans) and plants have two copies of each gene in their genome, one inherited from each parent

Telleparallel Lagrange Geometry and a Unified Field Theory: Linearization of the Field Equations

The present paper is a natural continuation of our previous paper: "Teleparallel Lagrange geometry and a unified field theory, Class. Quantum Grav., 27 (2010), 045005 (29pp)" \cite{WNA}. In this paper, we apply a linearization scheme on the field equations obtained in \cite{WNA}. Three important results under the linearization assumption are accomplished. First, the vertical fundamental geometric objects of the EAP-space loose their dependence on the positional argument $x$. Secondly, our linearized theory in the Cartan-type case coincides with the GFT in the first order of approximation. Finally, an approximate solution of the vertical field equations is obtained.Comment: 18 pages, LaTeX fil