On the numerical evaluation of algebro-geometric solutions to integrable equations

Physically meaningful periodic solutions to certain integrable partial differential equations are given in terms of multi-dimensional theta functions associated to real Riemann surfaces. Typical analytical problems in the numerical evaluation of these solutions are studied. In the case of hyperelliptic surfaces efficient algorithms exist even for almost degenerate surfaces. This allows the numerical study of solitonic limits. For general real Riemann surfaces, the choice of a homology basis adapted to the anti-holomorphic involution is important for a convenient formulation of the solutions and smoothness conditions. Since existing algorithms for algebraic curves produce a homology basis not related to automorphisms of the curve, we study symplectic transformations to an adapted basis and give explicit formulae for M-curves. As examples we discuss solutions of the Davey-Stewartson and the multi-component nonlinear Schr\"odinger equations.Comment: 29 pages, 20 figure

ECONOMIC ANALYSIS OF BROILER PRODUCTION AT MIANGO PLATEAU STATE, NIGERIA

This paper evaluate the economics of broiler production at Miango, Plateau State, Nigeria using a – 9 years record (1992 – 2000). During the period, 76 batches of broilers were reared to point of slaughter. The results shows that the enterprise incurred an average total variable cost of N620,6333.31 out of which feeding cost, day old chicks (stock) and mortality cost represents 58.13%, 19.13% and of 9.64% of the total cost of production, respectively. Total revenue within the period was estimated to be N763,969.44 which was mainly generated from the sales of broiler birds. The gross margin was found to be N143,334.13 with N0.23 as the returns per naira invested in the enterprise. Thus the broiler production is a profitable venture in the study area.Broilers, Income, Investment & Profitability, Livestock Production/Industries,

Exploration of CIGAS Alloy System for Thin-Film Photovoltaics on Novel Lightweight and Flexible Substrates

Thin-film photovoltaics (TFPV) on lightweight and flexible substrates offer the potential for very high solar array specific power (W/kg). ITN Energy Systems, Inc. (ITN) is developing flexible TFPV blanket technology that has potential for specific power greater than 2000 W/kg (including space coatings) that could result in solar array specific power between 150 and 500 W/kg, depending on array size, when mated with mechanical support structures specifically designed to take advantage of the lightweight and flexible substrates.(1) This level of specific power would far exceed the current state of the art for spacecraft PV power generation, and meet the needs for future spacecraft missions.(2) Furthermore the high specific power would also enable unmanned aircraft applications and balloon or high-altitude airship (HAA) applications, in addition to modular and quick deploying tents for surface assets or lunar base power, as a result of the high power density (W/sq m) and ability to be integrated into the balloon, HAA or tent fabric. ITN plans to achieve the high specific power by developing single-junction and two-terminal monolithic tandem-junction PV cells using thin-films of high-efficiency and radiation resistant CuInSe2 (CIS) partnered with bandgap-tunable CIS-alloys with Ga (CIGS) or Al (CIAS) on novel lightweight and flexible substrates. Of the various thin-film technologies, single-junction and radiation resistant CIS and associated alloys with gallium, aluminum and sulfur have achieved the highest levels of TFPV device performance, with the best efficiency reaching 19.5% under AM1.5 illumination conditions and on thick glass substrates.(3) Thus, it is anticipated that single- and tandem-junction devices with flexible substrates and based on CIS and related alloys will achieve the highest levels of thin-film space and HAA solar array performance

Consultation outcomes for musculoskeletal conditions at two community health centres in Cape Town

Objectives: To compare the proportion of patients with documented diagnoses and management plans when they presented with musculoskeletal complaints at two community health centres (CHCs) using two models of care: one with a rheumatology outreach service and the other with none. Secondly, to describe the profile of patients with rheumatoid arthritis (RA) who attended the CHC with the outreach service. Design: Cross-sectional. Setting: Heidelberg Community Health Centre and Vanguard Community Health Centre, Cape Town. Subjects: A group of 59 patients at each CHC were compared regarding engagement of their musculoskeletal complaints by doctors and clinical nurse practitioners (CNPs). Secondly, 24 RA patients who attended Heideveld CHC were profiled. Results: A comparison of the “overall engagement” between the two CHCs [risk difference (RD) -0.06, 95% confidence interval (CI): -0.17–0.05, odds ratio (OR) 0.79, 95% CI: 0.51–1.24, chi-square 0.82, p-value 0.36] was not significantly different. Comparison between doctors (RD -0.05, 95% CI: -0.05–0.08, OR 0.80, 95% CI: 0.46–1.40, chi-square 0.41, p-value 0.52) was also not significantly different. The comparison between the CNPs at the two CHCs was statistically significant (RD 0.30, 95% CI: 0.14–0.45, OR 8.37, 95% CI: 1.05–66.60, Fisher's exact test 0.01), but the CI around OR was large. Patients with RA had a mean age of 60 years, an average of two co-morbidities and an average of three annual clinic visits. Eighty- three per cent resided in the drainage area of the clinic. Conclusion: There was no significant difference in engagement between the CHCs. The potential that CNPs seemed to show of being positively influenced by the outreach service should be further researched. Patients with RA had co- morbidities that required management at primary healthcare level

On hypergeometric generalized negative binomial distribution

It is shown that the hypergeometric generalized negative binomial distribution has moments of all positive orders, is overdispersed, skewed to the right, and leptokurtic. Also, a three-term recurrence relation for computing probabilities from the considered distribution is given. Application of the distribution to entomological field data is given and its goodness-of-fit is demonstrated

Polyarteritis nodosa presenting as a bladder outlet obstruction

Polyarteritis nodosa (PAN) of the urinary tract is rare. An unusual case of systemic PAN involving the bladder neck is described. A 27-year-old man, with known diastolic hypertension diagnosed 2 years earlier, was admitted with chronic urinary obstruction complicated by hydronephrosis. He had symptoms of myalgia and weight loss, was afebrile but had an elevated erythrocyte sedimentation rate and acute-on-chronic renal impairment. All virological and serological tests including hepatitis B and anti-neutrophil cytoplasmic antibody were negative. A computed tomography scan of the brain revealed small-vessel disease. A bladder neck mass was visualised on cystoscopy. Histological examination of this demonstrated a medium-sized necrotising vasculitis with small-vessel fibrinoid necrosis suggestive of PAN. At least six of the American College of Rheumatology criteria for PAN were met. The patient was treated with pulses of intravenous cyclophosphamide and oral corticosteroids with a good clinical response

Profil épidémiologique de l’infection à VIH au cours d’une campagne de sensibilisation à Yaoundé au Cameroun

Introduction: L'objectif de ce travail était de déterminer le profil épidémiologique de l'infection à VIH/SIDA au cours d'une campagne de sensibilisation à Yaoundé au Cameroun. Méthodes: Après avoir obtenu le consentement éclairé des participants, le dépistage de l'infection par le VIH a été effectué selon l'algorithme de dépistage en série de l'Organisation Mondiale de la Santé (OMS). En outre, un questionnaire socio-comportemental a été proposé à chaque participant. Résultats: Au total, 911 personnes ont été dépistées. La prévalence de l'infection par le VIH était de 2.6%. Elle était 3 fois plus élevée parmi les femmes (RC=3.22, IC (1.26 - 8.18). Les prévalences les plus élevées ont été observées chez les personnes de plus de 45 ans (p=0.01), les personnes sans emploi (p<0.001) et les veufs/veuves (p=0.02). Plus de 80% des participants trouvaient le test de dépistage nécessaire et 76,2% l'avaient déjà effectué au moins une fois auparavant. Il s'agissait principalement de femmes (p=0.02), d'étudiants (p<0.001) et des personnes âgées de 25 à 34 ans (p<0.001). Les personnes séropositives avaient moins tendance à retirer leur résultat (p=0.01). Conclusion: Il apparait urgent d'intensifier les campagnes de dépistage de l'infection par le VIH en ciblant davantage des groupes particuliers tels que les élèves, les personnes âgées et les veufs/veuves, tout en recherchant les facteurs pouvant favoriser la propagation de l'infection dans ces groupes.Key words: Dépistage du VIH, prévalence, profil épidémiologique, campagne de sensibilisatio