166 research outputs found
Shouldice Versus Lichtenstein Hernia Repair Techniques: A Prospective Randomized Study
Background: The objectives of this study was to compare the tension-free mesh (Lichtenstein), and the 4-layer tissue repair (Shouldice) techniques of inguinal hernia surgery and to determine to what extent doctors in a general surgical unit were able to reproduce the excellent results reported from specialist hernia centres.Methods: Patients with primary unilateral inguinal hernia were over an 18month period randomized to either the Shouldice group (experiment) or to the Lichtenstein group (control). The operating time, convalescence, hospital stay, postoperative analgesic consumption and complications, were assessed and compared.Results: There Lichtenstein group had a shorter operating time but had a higher occurrence of persistent postoperative pain compared to the Shouldice group. There was no significant difference in convalescence between the two groups and no recurrences have been recorded in eithergroup. Conclusion: Despite Shouldice being more challenging to perform compared to Lichtenstein, the postoperative results are comparable. Ourexperience shows that both procedures can be taught to medical officers who can perform them with relative safety, efficacy and reproducibility tosurgeons. Shouldice method being the more cost effective procedure should be encouraged in men with primary unilateral inguinal hernias.Key Words: Hernia, Lichtenstein, Shouldice, Clinical Tria
Chronic Ileocecal Intussusception Secondary to Non-Hodgkins Lymphoma
Chronic intussusception is a distinct clinical entity which is unfortunately poorly recognized due to its atypical presentation. A 5½ year old female patient presented with a 5 month history of abdominal pain associated with occasional vomiting, anorexia and progressive weight loss. 5 days prior to admission she developed loose, non-mucoid, non-blood stained stool associated with refusal to feed and irritability. Systemic examination, an abdominal ultrasound and abdominal radiograph were non-contributory.During treatment for malnutrition and dehydration she was noted to clinically improve, however, 6 days post-admission she developed abdominal pain, a palpable sausage-shaped abdominal mass, and currant-jelly stool. Emergency laparotomy revealed an ileocecal intussusception with oedematous nonviable, aperistaltic terminal ileum and mobile cecum, a cecal mass and mesenteric lymphadenopathy was found. We performed a right hemicolectomy with an ileocolic anastomosis and mesenteric lymph node sampling. Histology results revealed the cecal mass as a lymphoproliferative neoplasm with a diagnostic consideration of intermediate to large cell Non-Hodgkins Lymphoma; and reactive hyperplasia of mesenteric lymph nodes. There is need for a highindex of suspicion in children with non-specific abdominal symptoms for which no cause can be found. Further, all suspicious masses should haveimmunohistological histological evaluation.Key Words: Chronic Ileocecal Intussusception, Non Hodgkins Lymphom
Bioinformatics platform: Harnessing bioinformatics for food security and sustainable development
Optimal energy mix of a microhydro-wind-grid system powering a dairy farm in Western Cape, South Africa
This paper presents an optimal control strategy of a grid-tied microhydro-wind power system for a rural dairy farm in South Africa. The problem is formulated as a multi-objective optimisation programme in discrete time domain to minimise grid imported energy cost under Time of Use Tariff (TOU) while at the same time maximising revenue generated from the sale of surplus renewable energy to the grid at a specified renewable energy feed-in tariff. The application of the proposed model to a practical case study shows the potential of the model to save the farmer the grid energy cost up to 75.07% in summer and 70.69% in the winter with a discounted repayment period of 3 years and 7 months.The MasterCard Foundation and the National Hub for Energy Efficiency and Demand Side Management.http://www.elsevier.com/locate/procediaam2018Electrical, Electronic and Computer Engineerin
Optimal control of conventional hydropower plant retrofitted with a cascaded pumpback system powered by an on-site hydrokinetic system
This paper presents an optimal control strategy for a hydropower plant retrofitted with a hydrokineticpowered
cascaded pumpback system in dry season. Pumpback operation aims at recycling a part of the
down-stream discharge back to the main dam to maintain a high water level to optimise the energy value
of the available water. The problem is formulated as a multi-objective optimisation problem to simultaneously
minimise the grid pumping energy demand, minimise the wear and tear associated with the
switching frequency of the pumps, maximise the restoration of the volume of the dam through pumpback
operation and maximise the use of on-site generated hydrokinetic power for pumping operation.
The performance of the proposed cascaded model is compared with the classical single pump pumped
storage model. Simulation results based on a practical case study shows that the cascaded pumpback
model can reduce the pumping energy demand by up to 48.18% and increase the energy yield of the
resultant system by up to 47.10% in dry season.The authors would like to thank the MasterCard Foundation, the
National Hub for Energy Efficiency and Demand Side Management South
Africa and the University of Zambia-Zambia for financial and
other support towards this research.http://www.elsevier.com/locate/enconman2018-01-31hb2017Electrical, Electronic and Computer Engineerin
Genotyping for point mutations in selected codons of pfcrt and pfmdr-1 genes of Plasmodium falciparum among patients with uncomplicated malaria in Mbita district Kenya.
Background Malaria remains a leading cause of morbidity and mortality in Kenya, especially in young children and pregnant women. Due to widespread resistance of Plasmodium falciparum to drugs such as Chloroquine (CQ) and Sulfurdoxine-Pyrthamine (SP), Artemisisnin Combination Therapy (ACT) was adopted in Africa as a means of improving treatment efficacy and slowing the spread of resistance. The development of drug resistance by the parasites for the various malaria drug regimens that have been in use before has been attributed to point mutations within the parasite genome. Therefore this study investigated the prevalence of point mutations in selected codons of the pfcrt and pfmdr-1 genes of Plasmodium falciparum. It is however unclear whether ACT will be effective in preventing the selection of resistant parasites in Africa, where parasite transmission rates are generally much higher with parts of Asia and Africa already reporting a reduction in sensitivity to ACT. Methods The dot-blot/probe hybridization technique was used to identify point mutations in codons 74, 75 and 76 of the pfcrt gene and codons 1034, 1042 and 1246 of the pfmdr-1 gene in Mbita a malaria holoendemic site in Kenya. In the pfcrt gene, 76T mutation was found to be in 91 (79.83% CI 63.1-88.5) of 114 samples while the, the wild type allele 76K was present in 23 (20.17% CI 9.0-22.0) samples. Codons 1246 showed allelic variation with 1246D the wild type allele being 72.8% (CI 52.0-89.1). This was a significant increase in the 76K allele (p=0.001) in comparison to the year 2005 where prevalence of 76K was 6%. Conclusion There’s an expansion of the wild-type allele 76K of the pfcrt gene and no significant difference in the 1246D allele of the pfmdr1 gene, moreover the prevalence of 76T allele is still high in Mbita hence it’s beneficial to continue using AL as treatment for uncomplicated malaria. Keywords: Malaria, Drug Resistance, Point Mutations
Enhancing resistance against African weevils through development of transgenic sweetpotato cultivars (Ipomoea batatas (L.) Lam.) expressing cry7Aa1, cry3Ca1 and ET33-34 genes.
Sweetpotato (Ipomoea batatas) is one of the most important food crops in tropical and subtropical countries. In Sub-Saharan Africa, sweetpotato is mainly produced for consumption and as a source of income by resource-poor farmers. However, their production is limited by severe damage caused by pests and diseases. The African weevils Cylas puncticollis and C. brunneus are the main biological constraints that may cause losses between 50 and 100%. Biotechnological approaches to control weevils include the introduction of genes encoding Cry proteins found to be active against these pests. To that end, several protocols for sweetpotato regeneration and transformation by organogenesis or somatic embryogenesis have been developed but their efficiency remains largely genotype-dependent and time-consuming. In this study, 31 African sweetpotato cultivars from CIP genebank were screened for regeneration and transformation efficiencies by organogenesis and somatic embryogenesis. Additionally, “Jewel” and “Jonathan” cultivars were used as organogenic and embryogenic controls, respectively. Regeneration by organogenesis was conducted using a two-step protocol including 2,4-D then thidiazuron, zeatin or kinetin while regeneration by embryogenesis was performed using a three-step protocol, each one using a different hormone (2,4,5-T, ABA and AG3). Higher than 40% regeneration efficiencies were obtained for 8 cultivars (Jewel, Imby, Kawogo, Luapula, Mafutha, CIP440163, Zambezi and Ukerewe) with an organogenesis protocol and 8 cultivars (Jonathan, Imby, K51/3251, Bwanjule, CIP440163, SPK004, New Kawogo and KSP 11) with an embryogenesis protocol. Genetic transformation of sweetpotato with Jewel by organogenesis and Imby, CIP440163 and Jonathan by somatic embryogenesis has been achieved using chimerical genes coding for three of the most active proteins (Cry7Aa1, ET33-34, and Cry3Ca1) against African weevils. Transgenic events have been confirmed by kanamycin resistant calli test, PCR and Southern blot. Transcriptional activity and Cry protein accumulation are being tested in leaves and storage roots by Real time PCR and DAS-ELISA respectively
Consistency of Mycobacterium tuberculosis-Specific Interferon-Gamma Responses in HIV-1-Infected Women during Pregnancy and Postpartum
Background. We determined the consistency of positive interferon-gamma (IFN-γ) release assays (IGRAs) to detect latent TB infection (LTBI) over one-year postpartum in HIV-1-infected women. Methods. Women with positive IGRAs during pregnancy had four 3-monthly postpartum IGRAs. Postpartum change in magnitude of IFN-γ response was determined using linear mixed models. Results. Among 18 women with positive pregnancy IGRA, 15 (83%) had a subsequent positive IGRA; 9 (50%) were always positive, 3 (17%) were always negative, and 6 (33%) fluctuated between positive and negative IGRAs. Women with pregnancy IGRA IFN-γ>8 spot forming cells (SFCs)/well were more likely to have consistent postpartum IGRA response (odds ratio: 10.0; 95% confidence interval (CI): 0.9–117.0). Change in IFN-γ response over postpartum was 10.2 SFCs/well (95% CI: −1.5–21.8 SFCs/well). Conclusion. Pregnancy positive IGRAs were often maintained postpartum with increased consistency in women with higher baseline responses. There were modest increases in magnitude of IGRA responses postpartum
2D-Galactic chemical evolution: The role of the spiral density wave
© 2019 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. We present a 2D chemical evolution code applied to a Milky Way type Galaxy, incorporating the role of spiral arms in shaping azimuthal abundance variations, and confront the predicted behaviour with recent observations taken with integral field units. To the usual radial distribution of mass, we add the surface density of the spiral wave and study its effect on star formation and elemental abundances. We compute five different models: one with azimuthal symmetry which depends only on radius, while the other four are subjected to the effect of a spiral density wave. At early times, the imprint of the spiral density wave is carried by both the stellar and star formation surface densities; conversely, the elemental abundance pattern is less affected. At later epochs, however, differences among the models are diluted, becoming almost indistinguishable given current observational uncertainties. At the present time, the largest differences appear in the star formation rate and/or in the outer disc (R ≥ 18 kpc). The predicted azimuthal oxygen abundance patterns for t ≤ 2 Gyr are in reasonable agreement with recent observations obtained with VLT/MUSE for NGC 6754
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