Numerical solution of Boundary Value Problems by Piecewise Analysis Method

In this paper, we use an efficient numerical algorithm for solving two point fourth-order linear  and nonlinear boundary value problems, which is based on the homotopy analysis method (HAM), namely, the piecewise – homotopy analysis method ( P-HAM).The method contains an auxiliary parameter that provides a powerful tool to analysis strongly linear and nonlinear ( without linearization ) problems directly. Numerical examples are presented to compare the results obtained with some existing results found in literatures. Results obtained by the RHAM performed better in terms of accuracy achieved. Keywords:            Piecewise-homotopy analysis, perturbation, Adomain decomposition method, Variational Iteration, Boundary Value Problems

Feasibility of Large-Scale Combined-Cycle Hydroelectric Power Generation at Shiroro Hydroelectric Power Station, Nigeria

This paper focuses on a model for increasing the power generation of a hydroelectric power station using the combined application of hydrokinetic turbines installed at the tailrace of the existing dam. Hydrokinetic turbines will capture additional power from the energy remaining in water currents exiting draft-tube outlets and tailrace of the dam. Two commercially available hydrokinetic turbines of different orientation were used for the analysis to theoretically estimate the increased power generation capability of Shiroro hydropower station using an array of 75, 150, 225 and 300 units. Preliminary results showed that at 50% reliability, combined-cycle hydropower can increase the generation capacity of Shiroro hydropower station by 2.5% and that there is a considerable power generation potentials that can be harnessed to augment existing output from the power station and alleviate the existing power problems in the country

Retropharyngeal Abscess in Adults: Five Case Reports and Review of the Literature

Retropharyngeal abscesses are rare in adults. They occur mostly in immunocompromised patients or as a foreign body complication. We report 5 cases of retropharyngeal abscess collected in the ENT Department of CHU Mohammed VI of Marrakech, during a two-year period (December 2008 to December 2009). Local trauma by foreign body ingestion was the aetiology in four patients. The presenting symptoms, for all patients, were fever, odynophagia, torticollis, and trismus, and the clinical examination showed bulging of the posterior wall of the oropharynx. The radiography of cervical spine showed prevertebral thickening in all cases, this thickening was associated with an aspect of vertebral lysis of the fourth cervical vertebra in one case. A CT scan was performed in all our cases and showed features of retropharyngeal abscess which was associated, in one case, with spondylodiscitis. The biological assessment found one case of diabetes. The intradermal reaction to the tuberculin was clearly positive in one case. Endobuccal abscess puncture was practiced in 4 cases; only one organism was identified by culture: Staphylococcus aureus treatment was based on triple intravenous antibiotics and anti-Koch's therapy (in one case), and the surgical drainage under general anesthesia was also performed in the case of the diabetes patient which required also the correction of hyperglycemia in intensive care unit. The outcome was good in all our patients. The diagnosis of retropharyngeal abscess can be difficult and one must seek a comorbidity; a tuberculosis aetiology must be considered in countries with a high prevalence. The management of these cases is based on antibiotics and surgical drainage

Cost savings in the Swiss healthcare system resulting from professional periodontal care

More than 740 million people worldwide are affected by periodontal disease and are at higher risk of secondary damage such as cardiovascular disease and type 2 diabetes, which place a considerable financial burden on healthcare systems. The aim of this study was to use a computer simulation to estimate the direct and indirect costs of prevention and treatment of gingivitis, periodontitis and related secondary damage in the Swiss population, paid both out of pocket (OOP) and from social welfare (SW). For three different scenarios, iterations with 200,000 simulated individuals over their assumed life span of 35 to 100 years corresponded to a period of four months in which an individual could move from one periodontal condition to the next, each associated with presumed direct and indirect treatment costs. Appropriate diagnosis and adherence to professional periodontal care had a strong benefit saving up to CHF 5.94 billion OOP and CHF 1.03 billion SW costs for the current Swiss population. Considering direct and indirect health care costs, the total expected costs for a 35-year-old individual until death were CHF 17'310 with minimal care and CHF 15'606 with optimal care, resulting in savings of CHF 1'704. In conclusion, early detection and appropriate treatment of periodontitis can help to reduce both overall costs of treating periodontitis and associated secondary damage, especially in the second half of life. These cost savings may further pay off on an individual level through regular supportive periodontal care, both for treatments paid out-of-pocket and those covered by social welfare

X-ray Absorption Near-Edge Structure (XANES) at the O K-Edge of Bulk Co₃O₄: Experimental and Theoretical Studies

We combine theoretical and experimental X-ray absorption near-edge spectroscopy (XANES) to probe the local environment around cationic sites of bulk spinel cobalt tetraoxide (Co3O4). Specifically, we analyse the oxygen K-edge spectrum. We find an excellent agreement between our calculated spectra based on the density functional theory and the projector augmented wave method, previous calculations as well as with the experiment. The oxygen K-edge spectrum shows a strong pre-edge peak which can be ascribed to dipole transitions from O 1s to O 2p states hybridized with the unoccu- pied 3d states of cobalt atoms. Also, since Co3O4 contains two types of Co atoms, i.e., Co3+ and Co2+, we find that contribution of Co2+ ions to the pre-edge peak is solely due to single spin-polarized t2g orbitals (dxz, dyz, and dxy) while that of Co3+ ions is due to spin-up and spin-down polarized eg orbitals (dx2−y2 and dz2 ). Furthermore, we deduce the magnetic moments on the Co3+ and Co2+ to be zero and 3.00 μB respectively. This is consistent with an earlier experimental study which found that the magnetic structure of Co3O4 consists of antiferromagnetically ordered Co2+ spins, each of which is surrounded by four nearest neighbours of oppositely directed spins

LES MUCOCELES SINUSIENNES : ASPECTS DIAGNOSTIQUES ET THERAPEUTIQUES, A PROPOS DE 16 CAS

Introduction: The sinus mucoceles are expansive pseudokystic benign tumours, whose wall is the sinus wall at least modified and of which sticky and aseptic contents.Patients and method: Our work is a retrospective study, bearing on 16 cases of sinus mucoceles in the service of ORL of hospital ANTAKI of Marrakech, from January 2000 to December 2006. It was interested in the characters epidemiologic, clinical, radiological, therapeutic and evolutionary of this pathology. Results: The average age in our series is 49 years, with extremes of 25 years and 81 years, and a sex ratio of a unit. The sinusal case histories were noted among four patients. The time with the consultation was 2 months in 48 months. The ethmoïdo-frontal sinus mucoceles in 12 cases (75% of the cases), were followed by the maxillary mucoceles in 2 cases (12,5 % of the cases) and by the sphenoid sinus mucocele in 2 cases (12,5%). In the ethmoïdo-frontal form, clinical symptomatology was dominated by the exophthalmia (100%), the tumefaction of the interior angle of the eye (100%) and the cephalus (67%). In the sphenoid form, the cephalus, the fall of vision and the exophtalmy dominated the clinical picture. In the maxillary form, the nasal obstruction associated with rhinorrhea was found among all patients. All the patients underwent an endoscopic visualization in the search of a suspect endonasal lesion. It highlighted a component endonasale of the mucocele in 60%. The diagnosis was marked in all the cases by the tomodensitometry of the sines which highlighted an orbital regional extension, endocranial or endonasal and guided the choice of the way initially and the knowledge of operational difficulties. The marsupialisation by endonasal way under endoscopic guidance was made among nine patients, including five ethmoido-frontal cases of mucocele, two cases of maxillaries mucoceles and two cases of sphenoid mucoceles. The initially combined way was used in seven ethmoido-frontal cases of mucoceles in front of the insufficiency of the gesture of marsupialisation. An anatomopathologic study of the mucocele wall did not objectify malignant lesions. The evolution noted two cases of recidivism. The retreat was 3 years and 10 months. Discussion: the sinus mucocele is an unsual pathology. Diagnosis is radio-clinical. Treatment is surgical. The endoscopic way take more and more place than the conventional surgery.Introduction : Les mucocèles sinusiennes sont des tumeurs bénignes pseudokystiques expansives des sinus dont la paroi est la paroi sinusienne plus ou moins modifiée, et dont le contenu gluant et aseptique. Patients et méthode : Notre travail est une étude rétrospective, portant sur 16 cas de mucocèles sinusiennes colligés au service d'ORL de l'hôpital ANTAKI de Marrakech, de Janvier 2000 à Décembre 2006. Résultats : La moyenne d'âge dans notre série a été de 49 ans, avec des extrêmes de 25 ans et 81 ans, et un sexe ratio d'une unité. Le délai à la consultation a été de 2 mois à 48 mois. Les mucocèles ethmoïdo-frontales ont été retrouvés dans 12 cas (75% des cas), suivies par les mucocèles maxillaires dans 2 cas (12,5% des cas) et par les mucocèles sphénoïdales dans 2 cas (12,5%). Dans la forme ethmoïdo-frontale, la symptomatologie clinique a été dominée par l'exophtalmie (100%), la tuméfaction de l'angle interne de l’oeil (100%) et les céphalées (67%). Dans la forme sphénoïdale, les céphalées et la baisse de l'acuité visuelle et l'exophtalmie dominaient le tableau c1inique. Dans la forme maxillaire, l'obstruction nasale associée à une rhinorrhée a été retrouvée chez tous les patients. L'endoscopie nasale a mis en évidence une composante endonasale de la mucocèle dans 60% des cas. La tomodensitométrie des sinus a mis en évidence une extension régionale orbitaire, endocrânienne ou endonasale. La marsupialisation par voie endonasale sous guidage endoscopique a été faite chez neuf patients. La voie d’abord combinée a été utilisée dans sept cas. L'étude anatomopathologique de la paroi mucocélique n'a pas objectivé de lésions malignes. L'évolution a noté deux cas de récidive. Le recul moyen est de 3ans et 10 mois. Discussion : la mucocèle sinusienne est une pathologie rare. Son diagnostic est radio-clinique. Le traitement est chirurgical. La voie endoscopique prend de plus en plus place par rapport à la chirurgie conventionnelle

Serospatial epidemiology of zoonotic Coxiella burnetii in a cross section of cattle and small ruminants in northern Nigeria

The persistent and highly transmissible Coxiella burnetii is a neglected infection that negatively affects reproductive parameters of livestock. It is also of zoonotic importance and has been reported to cause devastating human infections globally. Domestic ruminants represent the most frequent source of human infection. Data from Nigeria are very few and outdated. There is a significant gap in up-to-date information on the exposure, spatial distribution and risk factors of infection of this important disease. The exposure to C. burnetii was determined using sensitive serological assays in cattle and small ruminants. A total of 538 animals made up of 268 cattle and 270 small ruminants were sampled from three northern Nigerian states. The proportion of cattle sampled that were seropositive from the study locations were: Kwara 14/90 (15.6%; 95% CI: 8.8–24.7); Plateau 10/106 (9.43%; 95% CI: 4.6–16.7) and Borno 4/72 (5.56%; 95% CI: 1.5–13.6) states. Lower seroprevalence was recorded among the small ruminants sampled, with positives recorded from sheep and goat sampled from only Kwara state 6/184 (3.3%; 95% CI: 1.2–7.0); while none of the small ruminants sampled from Plateau were seropositive. The results of the bivariate analysis showed that none of the tested independent variables (village, age group, sex, breed of cattle, presence of ticks, reproductive status, and management system) were statistically significant factors associated with seropositivity of cattle for antibodies to C. burnetii. Stakeholders involved in animal husbandry should be duly educated on proper disposal of birth products as well as bodily fluids in order to reduce environmental contamination, persistence and human infection

Retropharyngeal Abscess in Adults: Five Case Reports and Review of the Literature

Retropharyngeal abscesses are rare in adults. They occur mostly in immunocompromised patients or as a foreign body complication. We report 5 cases of retropharyngeal abscess collected in the ENT Department of CHU Mohammed VI of Marrakech, during a two-year period (December 2008 to December 2009). Local trauma by foreign body ingestion was the aetiology in four patients. The presenting symptoms, for all patients, were fever, odynophagia, torticollis, and trismus, and the clinical examination showed bulging of the posterior wall of the oropharynx. The radiography of cervical spine showed prevertebral thickening in all cases, this thickening was associated with an aspect of vertebral lysis of the fourth cervical vertebra in one case. A CT scan was performed in all our cases and showed features of retropharyngeal abscess which was associated, in one case, with spondylodiscitis. The biological assessment found one case of diabetes. The intradermal reaction to the tuberculin was clearly positive in one case. Endobuccal abscess puncture was practiced in 4 cases; only one organism was identified by culture: Staphylococcus aureus treatment was based on triple intravenous antibiotics and anti-Koch's therapy (in one case), and the surgical drainage under general anesthesia was also performed in the case of the diabetes patient which required also the correction of hyperglycemia in intensive care unit. The outcome was good in all our patients. The diagnosis of retropharyngeal abscess can be difficult and one must seek a comorbidity; a tuberculosis aetiology must be considered in countries with a high prevalence. The management of these cases is based on antibiotics and surgical drainage

DNA Copy Number Analysis in Gastrointestinal Stromal Tumors Using Gene Expression Microarrays

We report a method, Expression-Microarray Copy Number Analysis (ECNA) for the detection of copy number changes using Affymetrix Human Genome U133 Plus 2.0 arrays, starting with as little as 5 ng input genomic DNA. An analytical approach was developed using DNA isolated from cell lines containing various X-chromosome numbers, and validated with DNA from cell lines with defined deletions and amplifications in other chromosomal locations. We applied this method to examine the copy number changes in DNA from 5 frozen gastrointestinal stromal tumors (GIST). We detected known copy number aberrations consistent with previously published results using conventional or BAC-array CGH, as well as novel changes in GIST tumors. These changes were concordant with results from Affymetrix 100K human SNP mapping arrays. Gene expression data for these GIST samples had previously been generated on U133A arrays, allowing us to explore correlations between chromosomal copy number and RNA expression levels. One of the novel aberrations identified in the GIST samples, a previously unreported gain on 1q21.1 containing the PEX11B gene, was confirmed in this study by FISH and was also shown to have significant differences in expression pattern when compared to a control sample. In summary, we have demonstrated the use of gene expression microarrays for the detection of genomic copy number aberrations in tumor samples. This method may be used to study copy number changes in other species for which RNA expression arrays are available, e.g. other mammals, plants, etc., and for which SNPs have not yet been mapped