Effect of high resistive barrier on earthing system

Substation earthing provides a low impedance path and carries current into ground under normal and fault conditions without adversely affecting continuity of service. Under a fault condition, the ground voltage may rise to a level that may endanger the public outside the vicinity of the substation. In such a case a high resistive barrier can be inserted around the vicinity of the substation to reduce the surface potentials immediately beyond the barrier. In this paper the effect of barrier on the overall performance of the earthing system has been investigated experimentally and computationally based on an earthing system consisted of combined grid and rods in a water tank. The effect of the position and depth of the barrier to the resistance of the earthing system and surface potentials in and around the substation have been examined

Ectopic Thyroid Presenting as a Sublingual Mass in a Sudanese Girl

Although extremely rare, the presence of ectopic thyroid tissue in the sublingual region should be considered in the differential diagnosis of masses in the cervical region. Diagnosis is confirmed by Fine-needle Aspiration\Biopsy Cytology and exclusion of malignancy by histopathologic analysis of the lesion. In general, surgery should not be attemptrd before radioisotope scan is obtained as this might be the only functioning thyroid tissue.  This is a rare case of ectopic thyroid in the sublingual region reported in a Sudanese girl; it was diagnosed after radioisotope thyroid scan and proved to be the only functioning thyroid tissue. &nbsp

The Performance of Candidates in the Examinations of the Otorhinolaryngology Specialty, Sudanese National Board of Medical Specializations

Introduction: The Otorhinolaryngology, Head and Neck Surgery Council is one of the first established councils of the Sudanese National Board of Medical Specializations (SNBMS).This report covers the fourth rotation period from 2009-2013. It is meant to be in the form of an analytical study for more objectivity and transparency and to be a model for promotion of the general performance of other councils in administrative, examination and training issues. Objectives: The main objective of this study is to analyze the trainees’ results in part 1 and part 2 (final) examinations with regard to gender and pass rates and to draw relevant indices that help in planning for training and expansion of specialist services. Materials and Methods: This is an analytical retrospective study conducted at the (SNMSB) headquarters Khartoum, Sudan during the period from January 2009- December 2012 .This study covers the fourth rotation of the scientific council for the specialty. The study included all candidates sitting for both part 1 and part 2 examinations (265). Candidates were classified according to gender and pass rates. Candidates who withdrew form the program after passing the part 1 examination were excluded. Results:  The total number of doctors sitting for part 1 examinant was 207. Females were 118 and males were 89. Female to male ratio was 1.3:1.0. Sixty nine (69) doctors passed the examination with over all pass percentage of 33.3%. The percentage of passed candidates among females was 31% and among males was 36%. The total number for trainees sitting for the final examination was 58. Females were 23 and males were 35. Female to male ratio was 1.0: 1.5. Thirty three (33) trainees passed the examination with over all pass percentage of 56.9%. The percentage of passed trainees among females was 52.2% and among males was 60%. The annual number of doctors sitting for part 1 examination showed marked reduction from 69 in the first year to 48 in the fourth year although there was a steady increase in-between. The average annual pass rate for part 1 examination showed noticeable increase from 23% to 42% by the end of the fourth year. The annual number of trainees sitting for the final examination was fluctuating and the biggest number was in the first year. There was a minimal increase in the number of graduates.  Conclusions: Applicants for part one examination are mostly females. Applicants numbers are generally decreasing. The pass percentages are increasing in both parts of the examination. Males performance in both part one and part two examinations is better than females. The number of graduates does not satisfy the national needs for specialist services provision and expansion

Einstein Geometrization Philosophy and Differential Identities in PAP-Geometry

The importance of Einstein's geometrization philosophy, as an alternative to the least action principle, in constructing general relativity (GR), is illuminated. The role of differential identities in this philosophy is clarified. The use of Bianchi identity to write the field equations of GR is shown. Another similar identity in the absolute parallelism geometry is given. A more general differential identity in the parameterized absolute parallelism geometry is derived. Comparison and interrelationships between the above mentioned identities and their role in constructing field theories are discussed.Comment: LaTeX file, 17 pages, comments and criticism are welcom

Primary Tuberculosis of the Maxillary Sinus: A case report

Tuberculosis is up-to-date a leading cause of human suffering and loss of life. Although tuberculosis is a systemic disease, primary tuberculosis of the paranasal sinuses is rare. It should be kept in mind in any undiagnosed or atypical clinical infection or inflammation in this region. We present here a case of primary paranasal sinuses tuberculosis in an elderly Sudanese woman. Although Sudan is one of the highest three countries in the incidence of tuberculosis, this is the first case to be reported in Suda

Common Ear, Nose & Throat Problems in the Under- Five Sudanese Children

Introduction: The health problems of children and especially the under-5 years are of great concern and impact on both medical and surgical practice. No wonder they attract political and administrative concern Objective: This study aims to identify the common Ear, Nose & Throat (ENT) problems of under-5 Sudanese children and to study the frequency, admissions, available beds and operations and to compare this work load with the rest of the ENT wards. Furthermore, to outline what is needed to improve the services for this age group. Methodology: This is a retrospective hospital–based study including all patients (n=21384) who presented to the ENT department, Wad-Medani Hospital, Gezira, Sudan, during a period of two years from the first of January 2010 to the thirty first of December 2011. Results: The total number of the under-5 children was 2330; which contributed to 41.32% of total paediatric age group, up to 16 years, (n=5639) and 10.90% of the total number of ENT patients who presented to the ENT department at Wad-Medani Hospital. The total number of admissions of under-5 children accounted for 32.72% of all paediatric patients and 20.66% of all ENT patients. Their commonest problems found in this study were; adenoiditis & tonsillitis (37.68%), otitis media (27.25%), Upper respiratory tract infections (URTIs) & allergy (12.31%), foreign body related (12.23%), otitis externa (5.45%), others (3.43%), epistaxis (0.75%), hearing & speech disorders (0.90%). The total number of children under-5 requiring surgical operations constituted 55.46% of all paediatric patients and 33.98% of the total number of all ENT patients who were operated on. Of these operations 57.01% were elective and 42.99% were emergency operations. The main indications in 94.77% of the elective operations were adenoidectomy & tonsillectomy, while most of the surgical emergencies 91.32% were due to foreign body related problems. Conclusions: The ENT problems of the under-5 children in Wad-Medani General Hospital constitute an obvious high proportion of the work load. More attention is to be paid to this age group in terms of facilities, staff training and special requirements needed in settings and equipments. Thus, better handling and outcomes could be achieved for this important and delicate age group

An Electronically Reconfigurable Patch Antenna Design for Polarization Diversity with Fixed Resonant Frequency

In this paper, an electronically polarization reconfigurable circular patch antenna with fixed resonant frequency operating at Wireless Local Area Network (WLAN) frequency band (2.4-2.48 GHz) is presented. The structure of the proposed design consists of a circular patch as a radiating element fed by coaxial probe, cooperated with four equal-length slits etched on the edge along x-axis and y-axis. A total of four switches was used and embedded across the slits at specific locations, thus controlled the length of the slits. By activating and deactivating the switches (ON and OFF) across the slits, the current on the patch is changed, thus modifying the electric field and polarization of the antenna. Consequently, the polarization excited by the proposed antenna can be switched into three types, either linear polarization, left-hand circular polarization or right-hand circular polarization. This paper proposes a simple approach that able to switch the polarizations and excited at the same operating frequency. Simulated and measured results of ideal case (using copper strip switches) and real case (using PIN diode switches) are compared and presented to demonstrate the performance of the antenna

Exploring The Effects Of Genetic Variation On Gene Regulation In Cancer In The Context Of 3D Genome Structure

Background Numerous genome-wide association studies (GWAS) conducted to date revealed genetic variants associated with various diseases, including breast and prostate cancers. Despite the availability of these large-scale data, relatively few variants have been functionally characterized, mainly because the majority of single-nucleotide polymorphisms (SNPs) map to the non-coding regions of the human genome. The functional characterization of these non-coding variants and the identification of their target genes remain challenging. Results In this communication, we explore the potential functional mechanisms of non-coding SNPs by integrating GWAS with the high-resolution chromosome conformation capture (Hi-C) data for breast and prostate cancers. We show that more genetic variants map to regulatory elements through the 3D genome structure than the 1D linear genome lacking physical chromatin interactions. Importantly, the association of enhancers, transcription factors, and their target genes with breast and prostate cancers tends to be higher when these regulatory elements are mapped to high-risk SNPs through spatial interactions compared to simply using a linear proximity. Finally, we demonstrate that topologically associating domains (TADs) carrying high-risk SNPs also contain gene regulatory elements whose association with cancer is generally higher than those belonging to control TADs containing no high-risk variants. Conclusions Our results suggest that many SNPs may contribute to the cancer development by affecting the expression of certain tumor-related genes through long-range chromatin interactions with gene regulatory elements. Integrating large-scale genetic datasets with the 3D genome structure offers an attractive and unique approach to systematically investigate the functional mechanisms of genetic variants in disease risk and progression

COVID-19 infection and death rates: the need to incorporate causal explanations for the data and avoid bias in testing

COVID-19 testing strategies are primarily driven by medical need - focusing on people already hospitalized with significant symptoms or on people most at risk. However, such testing is highly biased because it fails to identify the extent to which COVID-19 is present in people with mild or no symptoms. If we wish to understand the true rate of COVID-19 infection and death, we need to take full account of the causal explanations for the resulting data to avoid highly misleading conclusions about infection and death rates. We describe how causal (Bayesian network) models can provide such explanations and the need to combine these with more random testing in order to achieve reliable data and predictions for the both policy makers and the public