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

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

Prevalence and effect of parasitic infections on cycling in traditionally managed cattle herds in Bauchi, Nigeria

The incidence of infection and infestation by parasites (i.e. helminth, ectoparasites and haemoparasites) and the relationship between them and cycling in cattle was investigated in 16 traditionally managed herds in Bauchi, Nigeria. Parasitic infection and infestation show seasonality with most infections and infestations occurring in the rainy season. This study also shows some relationship between parasitic infection and infestation with cycling in some poorly managed herds. Good management practices were also shown to be important in disease control and prevention

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

Trabecular bone density in premenopausal rheumatoid arthritis patients

Objective. This study was undertaken to compare trabecular bone mineral density (BMD) in premenopausal rheumatoid arthritis. (RA) patients and normal age-matched controls.Method. A protocol was designed to record age, duration of disease, use of corticosteroids (CS) and/ or slow-acting antirheumatic drug (SAARD) therapy together with duration of such therapy. BMD was measured using the Hologic QDR 1 000 dual energy X-ray absorptiometer. The first four lumbar vertebrae and the left femur were measured in 56 RA patients and 165 controls. Height and weight were measured. Comparisons were made between RA patients and controls, as well as between subgroups of RA patients based on CS therapy.Results. Patients with RA had significantly lower BMD (P < 0.05) at all the sites than the normal controls. The mean duration of RA at the time of study was 60 months (standard deviation 58 months). Thirteen RA patients had used CS in doses less than 10 mg daily for 6 months or longer (mean 19 months), while 25 patients had been on SAARD for an excess of 6 months (mean 23 months). The CS-treated patients had significantly lower BMD than untreated subjects at the femoral neck and inter-trochanteric region (P < 0.05), but not at the lumbar spine. However, when compared with normal controls, the CS-treated subgroups had significantly lower BMD at the lumbar spine and all femoral areas. Trochanteric BMD was the best determinant of the RA group, with a sensitivity of 65% and specificity of 77%. The positive predictive value was 16%, while the negative predictive value was 10%. Using Bayes' theorem, the prevalence of osteopenia in RA was found to be6%.Conclusion. We conclude that generalised bone loss is a systemic feature of RA and that loss at the spine and femur may be aggravated by CS therapy

Composite Cutting with Abrasive Water Jet

Abrasive Water Jet (AWJ) technology has demonstrated to be an interesting manufacturing process for space, aircraft, boat and automotive sectors due to its specific advantages when machining composite materials. However, AWJ cutting of composite laminates possesses several challenges. It is necessary to develop a methodology to adapt the process parameters for each type of FRP & CFRP material which will allow AWJ trimming operations to be easily carried out on composite materials, since machine manufacturers still do not provide good databases for composite cutting. The presented work aims at studying the behaviour of a machinability model in composite materials. The machinability index for various composite materials with different thicknesses was found experimentally, which showed very different results for different materials. A study of the effect of the abrasive waterjet process parameters on the quality of cut (taper and surface roughness) was carried out

On mikusinski's operators of fractional integration

In the field F of convolution quotients,  b∝ is the operator of integration of fractional order ∝ and b∝ f   Is the Riemann - Liouville integral of order   ∝ of f. In this paper we give a generalization of this operator, which is denoted as b∝,va . Some particular cases are mentioned and the inverse operator is obtained

Transgenesis and Genomics in Molecular Breeding of Forage Plants

Forage plant breeding has been largely based on phenotypic selection following sexual recombination of natural genetic variation found between and within ecotypes. Advances in plant genetic manipulation over the last 15 years have provided convincing evidence that these powerful technologies can complement and enhance plant breeding programs. Significant progress in the establishment of the methodologies required for the molecular breeding of forage plants has been made. Examples of current products and approaches for the application of these methodologies to forage grass and legume improvement are outlined. Large-scale genomic analysis of many organisms is under way with human, arabidopsis and rice genome sequences almost completed. Forage plant breeding is just now entering the genome era. The plethora of new technologies and tools now available for high-throughput gene discovery and genome-wide gene expression analysis have opened up opportunities for innovative applications in the identification, functional characterisation and use of genes of value in forage production systems and beyond. Examples of these opportunities, such as ‘molecular phenotyping’, ‘symbio-genomics’ and ‘xeno-genomics’ are introduced