Non-symmetric magnetohydrostatic equilibria:a multigrid approach

Aims. Linear magnetohydrostatic (MHS) models of solar magnetic fields balance plasma pressure gradients, gravity and Lorentz forces where the current density is composed of a linear force-free component and a cross-field component that depends on gravitational stratification. In this paper, we investigate an efficient numerical procedure for calculating such equilibria.Methods. The MHS equations are reduced to two scalar elliptic equations – one on the lower boundary and the other within the interior of the computational domain. The normal component of the magnetic field is prescribed on the lower boundary and a multigrid method is applied on both this boundary and within the domain to find the poloidal scalar potential. Once solved to a desired accuracy, the magnetic field, plasma pressure and density are found using a finite difference method.Results. We investigate the effects of the cross-field currents on the linear MHS equilibria. Force-free and non-force-free examples are given to demonstrate the numerical scheme and an analysis of speed-up due to parallelization on a graphics processing unit (GPU) is presented. It is shown that speed-ups of ×30 are readily achievable

Stem cell research: a religious and ethical perspective

Stem cell research is among the most promising and controversial technological breakthroughs of our time. Stem cells are the cells from which all 210 different kinds of tissue in the human body originate. There are great potential to relieve human disease and suffering. The first studies on stem cells began in the 60s. Scientists have isolated the first human embryonic stem cell lines specifically tailored to match the nuclear DNA of patients, both male and female of various ages, suffering from disease or spinal cord injury. Because many diseases result from the death or dysfunction of a single cell type, scientists believe that the introduction of healthy cells of this type into a patient may restore lost or compromised function. Stem cells are able to divide, while maintaining their totipotent or pluripotent characteristics. Early in mammalian development, stem cells (embryonic stem cells); have the ability to differentiate into every cell of the human body (totipotent), potentially forming an entire fetus. Stem cells derived from later stages of mammalian development have the ability to differentiate into multiple cell types, but not into an entire organism. Adult stem cells are generally limited to differentiating into different cell types of their tissue of origin Most cells in the human body are differentiated and have the ability to form only cells similar to them. If one can manipulate the conditions controlling cellular differentiation, it may be possible to create replacement cells and organs, potentially curing illnesses such as diabetes, Alzheimer's disease, Parkinson's disease and other potentially serious illnesses.. Embryonic Stem cells for research are obtained from the surplus fertilized embryos in infertility management with IVF, from aborted fetuses, umbilical cord and cloning whether therapeutic or reproductive. The overwhelming objection to stem cell research is that it involves the destruction of an embryo or foetus. For many, this constitutes destruction of a potential human, and conflicts with religious and moral views held in our society. For others, the potential for this research to provide treatments and possibly cures for debilitating illnesses that have no cure and significantly impact on our way of life overrides this concern. Central to any argument on this is what actually constitutes the beginning of life for a human. Opinions on this vary from the moment of conception to a 14 day embryo and a living baby at birth. The other major ethical issue associated with stem cell research ties in with the combination of embryonic stem cell and cloning technologies. This newly emerging technology has caused a great deal of ethical, legal, and theological discussion and debate. Is IVF permitted to begin with? Are pre-embryos included in the prohibition of abortion? May a very early embryo be sacrificed for stem cells that could save lives or at least cure disease? May we fertilize ova specifically to create an embryo to be sacrificed for stem cells? With 'surplus' embryos cryopreserved in IVF clinics, is there a need to create additional embryos solely for purposes of stem cells basic research? Need we make "fences" in the form of protective laws to protect fetuses from wanton destruction? May tissue from aborted fetuses be used for research or medical treatment?. This paper discusses stem cell research in an ethical and religious perspective showing the Islamic, Catholic, Judaism and secular ethical views. it also projects possible compromises that could be utilized and urges local authorities to develop regulations for all clinical and research work that involves the human embryo

Hepatitis B virus and hepatitis C virus in pregnant Sudanese women

<p>Abstract</p> <p>Background</p> <p>The epidemiology of viral hepatitis during pregnancy is essential for health planners and programme managers. While much data exist concerning viral hepatitis during pregnancy in many African countries, no proper published data are available in Sudan.</p> <p>Aim</p> <p>The study aimed to investigate the sero-prevalance and the possible risk factors for hepatitis B virus (HBV) and hepatitis C virus (HCV) among antenatal care attendants in central Sudan.</p> <p>Methods</p> <p>During 3 months from March–June 2006, sera were collected from pregnant women at Umdurman Maternity Hospital in Sudan, and they were tested for markers of hepatitis B virus (HBVsAg) and HCV.</p> <p>Results</p> <p>HBVsAg was detected in 41 (5.6%) out 728 women, Anti-HCV was detected in 3 (0.6%) out of 423 women, all of them were not aware of their condition. Age, parity, gestational age, residence, history of blood transfusion, dental manipulations, tattooing and circumcision did not contribute significantly to increased HBVsAg sero-positivity.</p> <p>Conclusion</p> <p>Thus 5.6% of pregnant women were positive for HBVsAg irrespective of their age, parity and socio-demographic characteristics. There was low prevalence of Anti-HCV.</p

Obturator with soft liner in the management of hard palate defect: A case report

Maxillary defects are created following surgical treatment of patients with congenital defects, trauma, or neoplasm. Oral cancer is one of the more common malignanciesif detected lately massive tissues will be excised surgically and correction will be challenging. One of the treatment strategies is obturator, the retention of which is a major problem. 70 years old female presented with complaint of difficulty in chewing, speech and unlike her appearance. Hemimaxillectomy (or transectomy) was done 6 months ago as surgical treatment of squamous cell carcinoma resulted in a huge hole on the right side of the remaining maxilla.The size of the defect was about 3.0X1.5 cm. Acrylic obturator was made. Soft liner (Mucopren, Germany) was added to the fitting surface of the obturator. The patient’s speech, swallowing, mastication and facial appearance were improved. The use of hard acrylic base obturator with soft linear rendered the obturator more retentive and comfortable to the patient. To the best of our knowledge this is the first case to be reported in Sudan in a method different from those used by others worldwide.Keywords: Obturator, soft linear, maxillary defect, Sudan

Adjustment programmes and agricultural incentives in Sudan: a comparative study

Corr. versio

EFFECT OF PHOSPHATE ROCK AND TRIPLESUPERPHOSPHATE ON GROWTH AND LEAF N, P AND K CONTENTS OF GROUNDNUT (ARACHIS HYPOGAEA L.) GROWN ON A CLAY SOIL

A pot experiment was carried out to investigate the agricultural value of a local phosphate rock (PR) as a source of plant phosphorus compared with that of the currently imported triplesuper-phosphate (TSP) .The PR was applied at the rate of 0, 55, and 110 kg P2O5 /ha and the TSP was at the rate of 0, 45 and 90 kg P2O5 /ha. The growth and leaf contents of N, P and K of groundnut (Arachis hypogaea L.) grown on a clay soil were measured. The experiment continued for two sea-sons. Phosphatic fertilizers are of low recovery; therefore, they can remain for the next crop. Thus, the pots of the first season were set to study the residual effect of phosphorus in the second season. The results indicated that PR and TSP significant-ly (P>0.05) increased dry weights of shoot and root, leaf contents of N , P and available soil phosphorus. However, plant height was signifi-cantly increased by TSP only. The leaf content of K was neither affected by PR nor TSP application. The results showed a positive effect of the residual PR and TSP on the measured parameters. Moreo-ver, the results revealed that the plant measure-ments obtained from PR treatments were compa-rable to those obtained from TSP treatments which indicate that PR can be used as a potential source of phosphorus fertilizer

A Packet Scheduling Scheme for Improving Real-time Applications Performance in Downlink LTE–advanced

Quality of Service based packet scheduling is a key-feature of LTE-A mandating selection and transmission of individual user packets based on their priority. HARQ Aware Scheduling, Retransmission Aware Proportional Fair, Chase Combining Based Max C/I Scheduling and Maximum- Largest Weighted First (M-LWDF) are popular Packet Scheduling Algorithms (PSAs) developed to meet QoS requirements. In highly erroneous LTE-A cannel, M-LWDF is considered to be one of best PSA. To validate the performance of M-LWDF for the LTE-A channel, Mean User Throughout, and Fairness performance measures were evaluated for 3 different PSAs designed based on M-LWDF algorithm in this paper. A C++ based simulation results indicate the superiority of the PSA3 algorithm within the threshold of the performance measures against benchmarks. It has shown more efficiency and the performance of RTA traffic was enhanced. Results show that PSA3 is superior to its benchmark PSA2 by 12% in Mean User Throughput and 11% in Fairness. PSA2 performed the worst because it prioritizes new users and it allocated all available RBs to the scheduled user leaving the rest to wait in the buffer. PSA3 maintians good Mean User Throughput and fairnessdue to scheduling each user on its RB which leads to multi-user diversity

The effect of water deprivation on the pharmacokinetics of antipyrine and sulphadimidine following intravenous administration in Nubian goats

The effect of water deprivation on the pharmacokinetic parameters of antipyrine and sulphadimidine in the Nubian goat was studied. Water deprivation, to a level of dehydration at which the animals lost an average of 7.5% body weight, resulted in a significant reduction in antipyrine clearance (p < 0.05), and a consequently increased AUC value (p < 0.05). No effect was observed on the distribution parameters of the drug. In dehydrated animals which had lost an average of 10% or 12.5% of their body weight owing to water deprivation, significant changes were found in the distribution and elimination pharmacokinetic parameters of antipyrine and sulphadimidine. The volume of distribution was significantly decreased, resulting n elevated plasma levels for the two drags compared to normally watered animals. Significant decreases in clearance and subsequent prolongation of the elimination half-lives were observed during these periods of water deprivation. These changes in the disposition kinetics of the two drugs may be attributed to the loss of total body water and extracellular fluids and changes in the liver and kidney functions taking place during dehydration

Maximum-largest weighted delay first algorithm for heterogeneous traffic in 4G networks

Real time applications with strict QoS like delay sensitive applications require an advanced technology to adopt them. This is where Long Term Evolution-Advanced (LTE-A) fulfills this requirement. With this ever evolving technology the need for improvements is required. Packet scheduling is one of the important key features of LTE-A, where it dictates user selection and transmission of those user’s packets based on the priority of the users to reach the receiver correctly. Packet scheduling is one mean to achieve those QoS requirements that real-time applications require. Such algorithms are HARQ Aware Scheduling Algorithm (HAS), Retransmission Aware Proportional Fair Algorithm (RAPF), Chase Combining Based Max C/I Scheduling and Maximum- Largest WeightedDealy First algorithm (M-LWDF). In this paper, M-LWDF is one of the best algorithms in LTE-A which was chosen for further investigated to support QoS in high mobility environment. Packet Loss Ratio (PLR), and Mean User Throughput performance measures were used to validate the performance of M-LWDF algorithm against other algorithms using similar mobile environment. Simulation results indicate the capability of M-LWDF algorithm within the threshold of the performance measures against other benchmarks where it has demonstrated more efficiency to support and improve the performance of real-time multimedia traffic