Representations and Positive Definite Functions on Hypergroups

Some relationships between representations of a hypergroup X, its algebras, and positive definite functions on X are studied. Also, various types of convergence of positive definite functions on X are discussed

Myocardial bridge and coronary arteries: morphological study and clinical significance

Myocardial bridge (MB) is the myocardial bundles covering a segment of a coronary artery or one of its branches. This work aimed to study the morphological properties of MB and their effects on the structure of the dominant coronary artery. Sixty adult human hearts (40 male and 20 female) were obtained from the Anatomy Department, Faculty of Medicine, King Abdulaziz University. Dissection o fthe coronary arteries and their main branches was done. Number, site, length and thickness of MB were determined in correlation with coronary dominancy. External diameter of proximal and distal segments of bridged branches and histology of the different segments of the anterior interventricular artery were examined as well. Thirty-six MB were observed in 27 (45%) hearts (18 male and 9 female). MB were mostly observed on the middle segment of the anterior interventricular artery (52.8%) and to a lesser extent on its diagonal branch (13.8%), posterior interventricular artery (13.8%), median and left marginal branches (5.6%), and right coronary artery stem (2.8%). In 30% out of 56.7% of right, in 8.3% out of 26.7% of balanced and in 6.7% out of 16.7% of left dominant hearts revealed MB. The mean length of MB was 24.9 ± 1.98 mm and that of their thickness was 2.28 ± 0.13 mm. Morphological differences in external diameter and histological structure of the different parts of bridged branch were observed. Knowledge of morphological aspects and effects of MB provide better therapeutic and surgical interventions for clinicians dealing with patients having MB

A Study of the Affective Domain in School Science

It has been found that the present science syllabuses to 'O' grade contain material which is of high social relevance. However, normal classroom teaching can take place quite satisfactorily from a certificate point of view but neglect the conscious teaching of these socially important topics. It seems that schools are successful with the cognitive domain but tend to be less successful in helping to develop desirable social attitudes and the willingness to communicate. The purpose of this study is to enable the 'O' grade pupils to develop desirable social attitudes and awareness, change existing attitudes, and as a bonus, to encourage the development of group skills such as communication, co-operation and discussion. Pour topics were chosen for the purpose of the study - "Food and Man" in the third year biology syllabus; "Water Pollution, "Air Pollution" and "Bronchitis and Cancer of the lung", all these three are in the fourth year biology syllabus. Two different kinds of material were prepared, one for the Experimental Group, and the other for the Control Group. For the Experimental Group it included (a) media : games, simulation games, a multimedia package and audio-visual programme; (b) pupil tests; (c) / (c) teacher questionnaire; (d) articles . For the Control Group it included -(a) factual articles; (b) pupil tests; (c) teacher questionnaire. Six schools were chosen for the purpose of the study, and the pupils who used the material were in third and fourth year leading to 'O' grade. The general method of application was that the Experimental Group was provided with the simulation and other new materials, whereas the Control Group was provided with an article containing the same facts as appeared in the simulation, etc. Then both were given the same cognitive and affective tests. Findings showed that the study for the Experimental Group has - (a) provided a useful addition to the work normally carried out in the classrom; (b) contributed to the knowledge reinforcement and recall; (c) helped the pupils to be willing to communicate their understanding to others (through discussion, argument, presentation and reporting); (d) provided the motivation advantage by helping the pupils to develop a high level of interest, enthusiasm and excitement; (e) / (e) helped the pupils to become capable of making their own decisions; (f) encouraged the pupils to be able to work co-operatively with others; (g) provided interaction and peer learning

The radial artery and its variations: anatomical study and clinical implications

Objectives: to describe the radial artery and its variants in origin, branching pattern, mode of termination, measurements of its length and external diameter.Methods: 100 upper limbs of 30 men & 20 women adult cadavers were used in this study.  The cadavers were obtained from the Anatomy department, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.  The axillary region, arm, forearm and hand of each limb were dissected to clarify the course and branches of radial artery.  This anatomical descriptive study was conducted between September, 2010 and August, 2012 after approval the ethical committee.Results: the mean distance of the normal origin of radial artery as one of two terminal branches of brachial artery was 38.7±9.5mm in men & 36.5±8.5mm in women upper limbs below the intercondylar line while, variant origin of radial artery was found in eight limbs.  The mean of radial artery length was 226.2±21.7mm in men and 209.9 ±13.9 mm in women limbs and that of its external diameter was 3.3 ±0.7 mm in men & 3.2±0.66mm in women at 1 cm distal to its origin; 3.1±0.73 mm in men & 3.0±0.66 in women at 2cm proximal to styloid process of radius.  The radial artery showed different branching patterns and three modes of termination.Conclusion: Knowledge of radial artery description and its variants has great importance in different clinical fields and basic medical studies

Wind reduction patterns around isolated biomass for wind erosion control in a desertified area of Central Sudan

The aim of this study was to assess the effectiveness of sparse vegetation, feature common in arid zone, to reduce wind force (velocity) and hence protect the surface and regions downwind from drifting sand and their consequences. Respectively 4 (with heights h of 4, 3.2, 2 and 1.66 m), 2 (with h of 3 and 2.5 m) and 3 (with h of 1.04, 0.9 and 0.8 m ) well established single biomass configurations of Leptadenia pyrotechnica trees, Prosopis juliflora trees and Panicum turgidum grass, were selected in the field. Solar powered cup anemometer wind measurements with a data logger system were taken at heights of 0.25 and 0.5 h, at distances 0.5 and 1 h, at four sides of the tree in the prevailing wind direction and perpendicular to it, and additionally at 2, 4 and 6 h windward and leeward. The protection effectiveness of the biomass was calculated as a wind reduction ratio and in terms of objects protection, which was evaluated using the dimensionless protection index (É). The study showed that windward protection provided by Leptadenia and Prosopis at level 0.25h and distance 0.5 h was similar, w ith a wind reduction ratio R0.8, while Panicum showed comparably higher R-values. Even at the 0.5 h level, Panicum showed an R of 0.65 at 0.5 h distance. Leew ard, at 0.25 h level differences were small, R increasing from 0.6/0.7 to 0.8/1 with distance, Leptadenia protecting best. At higher level (0.5 h) at distances 0.5 and 1 h Prosopis gave better protection than the other two at distances 0.5, 1 and 2 h. The research is an exam ple of simple experimental work under difficult environmental conditions in Africa. It was part of studies in which additional attention was paid to quantification aspects under such conditions as well as to the problems it helped solve in the African societies concerned as agrometeorological service