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Search Results: 1 - 10 of 10463 matches for " Tawanda Jonathan Chisango "
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Differences in Serum Levels of Magnesium, Phosphate, and Albumin for HAART-Experienced and HAART-Na?ve Female Patients Attending Parirenyatwa Opportunistic Infections Clinic in Harare, Zimbabwe
Denise Mudzinge,Tinashe Kenny Nyazika,Tawanda Jonathan Chisango,Danai Tavonga Zhou
ISRN AIDS , 2013, DOI: 10.1155/2013/383214
Abstract: Antiretroviral therapy inhibits HIV replication, maintains health, and preserves life. However, both antiretroviral therapy and HIV infection have been reported to have short- and long-term effects on bone metabolism. A cross-sectional study was performed to compare serum bone profiles in HIV positive patients on highly active antiretroviral therapy and compare them to therapy-na?ve patients. Serum levels of calcium, magnesium, phosphate, and albumin were measured in 40 female participants on highly active antiretroviral therapy, recruited sequentially from Parirenyatwa Opportunistic Infections Clinic, Harare, Zimbabwe. The 40 women were matched for age with 40 antiretroviral therapy-na?ve women. Magnesium, phosphate, and albumin levels were significantly higher in the therapy-na?ve than in therapy-experienced patients. There was no statistically significant difference in calcium levels of the two groups of women. Evidence from this study suggests that highly active antiretroviral therapy lowers levels of magnesium, phosphate, and albumin but has no effect on levels of serum calcium. 1. Introduction Zimbabwe is in sub-Saharan Africa which is at the epicenter of the human immune deficiency virus (HIV) epidemic. According to UNAIDS the prevalence of HIV in Zimbabwe has decreased to about 1 in 10 adults (2012) from a high one of almost 1 in 4 in 2002 [1]. While the decline is commendable HIV infection still remains a major problem in Zimbabwe with 14.3% of adults being HIV positive [2]. The high disease burden of HIV has necessitated a rapid increase in the use of highly active antiretroviral therapy (HAART). As of 2012, over 476 thousand HIV-infected Zimbabweans were on HAART compared to only 8000 in 2003 [1]. In the Zimbabwe National Program, first line drug combinations include a dual combination of tenofovir/TDF/disoproxil fumarate (Gilead Sciences, USA); a nucleoside reverse transcriptase inhibitor (NRTI) and lamivudine/3TC/2,3 dideoxy-3-thiacytidine (GlaxoSmithKline and Pfizer, UK), an NRTI and a triple combination of tenofovir, lamivudine with nevirapine/XR/viramune (Boehringer Ingelheim, USA) a non-nucleoside reverse Transcriptase inhibitor (NNRTI) [3, 4]. In the event of treatment failure the patients are treated with second line drugs including zidovudine/AZT (Company) an NRTI; didanosine/DDI/Videx (Bristol-Myers Squibb Co, USA), an NRTI together with lopinavir and ritonavir; protease inhibitors (PIs) also known as kaletra/aluvia (Abbot Laboratories) [3]. HAART has reduced both the morbidity and mortality of HIV-infected people due to AIDS.
Factors Affecting Knowledge Production in Open and Distance Learning in Zimbabwe. Case of Zimbabwe Open University
Tawanda Dzama,Chisango F.T Future
International Journal of Asian Social Science , 2012,
Abstract: Zimbabwe Open University has been in existence for over a decade and is the only institution offering open and distance learning in Zimbabwe. The institution when it started had the highest enrolment which was higher than four conventional state universities combined. Currently the university is on the enrolment decline. This is contrary to the fact that distance education is spreading to almost all areas of education and training worldwide. It is also against the background that the Government is channeling many resources towards the establishment of a fully integrated distance learning system which involves the development of course materials and providing student support and instruction. This exhibits negative forces acting against knowledge production as less and fewer graduates are produced. Therefore the purpose of this paper was be to examine the key factors affecting open and distance learning in Zimbabwe. A descriptive survey design was adopted in form of a structured questionnaire which was used to collect data from 70 undergraduates, and 20 students post graduates. Also an interview guide was developed to carry out interviews to 10 staff members consisting of 2 Regional Directors, 2 Regional administrators, and 6 lecturers. Descriptive statistical analysis was a basic one which involves finding frequency of factors and converts them to percentages. This method was able to reduce lots of data into simpler summaries to present easily.
A new proof of the nonrationality of cubic threefolds
Tawanda Gwena
Mathematics , 2002,
Abstract: A new proof of the non-rationality of a generic cubic threefold is given as follows: If a generic cubic threefold were rational then the associated intermediate Jacobian would be a product of Jacobians of curves. We degenerate a generic cubic threefold to the Segre Cubic Threefold and so there is a degeneration of intermediate Jacobians as well. Associated to the degenerating family of Pryms is a unimodular system of vectors. Rationality of the generic cubic threefold would imply that the unimodular system would be cographic dicing. However, we show that the unimodular system obtained is a well known symmetric non-cographic dicing called E_5.
Effects of Long Term Cropping Systems on Soil Chemical Properties
U. Mazarura,C. Chisango
Asian Journal of Agriculture and Rural Development , 2012,
Abstract: In this study we examined the impact on soil C, total soil N and available P of six rotations namely: long season tobacco cultivar ‘KM10’ grown continuously (ContKM10), medium season tobacco cultivar ‘RK8’ grown continuously (ContRK8), grass-grass-grass-KM10 (G-G-G-KM10), grass-grass-grass-RK8 (G-G-G-RK8), KM10-Crotalaria juncea (KM10-Cr) and RK8-Crotalaria juncea (RK8-Cr). The experiment was established in 1990 under irrigation on a sandy loam soil at Kutsaga Research Station, Zimbabwe. Soil samples were taken from 0- to 15-cm deep, after each season. After 9 years, tobacco-grass rotations showed higher soil C than monocropping, regardless of variety. The monocropping systems, ContKM10 and ContRK8, did not differ from KM10-Cr and RK8-Cr respectively showing that when crop intensity is maintained soil C will be reduced regardless of a winter C. juncea green manure in a sandy loam soil. After 9 years, soil N was greatest in the G-G-G-KM10 rotation. Available P was lower in the grass (G-G-G-KM10, G-G-G-RK8) relative to the other rotations regardless of variety. Available P accumulated in monocropping systems (ContRK8, ContKM10) and was consistently lower in the grass-tobacco rotations. This indicated an accumulation of P in the case of monocropping systems because of continuous inorganic fertiliser input. The results reaffirmed the deleterious effect of monocropping and suggested the need for diverse rotations.
Anidulafungin in the treatment of invasive fungal infections
Kathryn Sabol,Tawanda Gumbo
Therapeutics and Clinical Risk Management , 2008,
Abstract: Kathryn Sabol, Tawanda GumboUniversity of Texas Southwestern Medical Center, Dallas, TX, USAAbstract: More antifungal agents have reached clinical use in the past two decades than at any other time. The echinocandins have been a welcome addition to this group, with the latest being anidulafungin. There are several lines of evidence to support anidulafungin’s role as primary therapy for the treatment of invasive candidiasis in non-neutropenic patients, and as alternative therapy to fluconazole in patients with esophageal candidiasis with azole intolerance or triazole-resistant Candida. Pharmacokinetic–pharmacodynamic studies in animals have demonstrated superior efficacy, defined as maximal microbial kill, when compared to fluconazole, regardless of the fluconazole susceptibility of the Candida species. These studies, as well as dose-effect studies in patients, also support the currently recommended dose of anidulafungin. A well designed randomized controlled trial has demonstrated anidulafungin’s efficacy in patients with invasive candidiasis. In this paper, we argue that anidulafungin may be preferable to fluconazole for the treatment of candidemia. However, as of yet, the difference between anidulafungin and the other two licensed echinocandins as first-line therapy for invasive candidiasis is unclear. On the other hand, there is insufficient evidence as of yet to support first-line use of anidulafungin in patients with neutropenia or aspergillosis.Keywords: anidulafungin, pharmacokinetics-pharmacodynamics, efficacy, candidiasis
Management of the Root Knot Nematode (Meloidogyne Javanica. Treub) and Sore Shin (Rhizoctonia Solani. Kuhn) Using A Nematicide and Poor Host Crops in Rotations
U. Mazarura,C. Chisango,M. Goss
Asian Journal of Agriculture and Rural Development , 2012,
Abstract: In a long term study the effects of a nematicide and six rotations: root-knot-susceptible tobacco, Nicotiana tabacum L. cv.‘KM10’ grown continuously (ContKM10), root-knot-resistant tobacco cv. ‘RK8’ grown continuously (ContRK8), grass-grass-grass-KM10 (G-G-G-KM10), grass-grass-grass-RK8 (G-G-G-RK8), KM10-Crotalaria juncea (KM10-Cr) and RK8-Crotalaria juncea (RK8-Cr), on root knot nematode, Meloidogyne javanica and sore shin, Rhizoctonia solani infection were studied. The nematicide used was ethylene dibromide (EDB) and was applied to each tobacco crop, as is standard practice. Chloris gayana cv. ‘Rhodes Katambora’, presumably a poor host of nematodes, was the grass used in all the grass-grass-grass-Tobacco rotations. The treatments were arranged in a randomized complete block design. ContKM10, KM10-Cr, G-G-G-RK8, ContiRK8 and RK8-Cr reduced root knot galling while G-G-G-KM10 increased galling. Sore shin increased with every year of rotation regardless of rotation, except in the case of G-G-G-KM10 and G-G-G-RK8 which reduced infection relative to other rotations. With the exception of G-G-G-RK8, all rotations that included RK8 suppressed root knot infection but did not suppress sore shin infection. The rotations including KM10 suppressed nematodes only with EDB treatment yearly and did not suppress sore shin except the rotation G-G-G-KM10. The role of Crotolaria juncea was masked by either RK8 or EDB. Host plant resistance in the form of RK8 was effective in controlling nematodes but did not reduce sore shin except mildly when rotated with the grass. This work recommends the use of resistant cultivars with broad-spectrum resistances.
Quantification of echodensities in tuberculous pericardial effusion using fractal geometry: a proof of concept study
Mpiko Ntsekhe, Bongani M Mayosi, Tawanda Gumbo
Cardiovascular Ultrasound , 2012, DOI: 10.1186/1476-7120-10-30
Abstract: We used fractal geometry to quantify the echocardiographic densities in patients who were enrolled in the Investigation of the Management of Pericarditis in Africa (IMPI Africa) Registry. Sub-costal and four chamber images were included in the analysis if a minimum of two clearly identified fibrin strands were present and the quality of the images were of a standard which allowed for accurate measurement of the fractal dimension. The fractal dimension was calculated as follows: Df?=?limlog N(s)/[log (l/s)], where Df is the box counting fractal dimension of the fibrin strand, s is the side length of the box and N(s) is the smallest number of boxes of side length s to cover the outline of the object being measured. We compared the fractal dimension of echocardiographic findings in patients with effusive constrictive pericarditis to effusive non-constrictive pericardial effusion using the non-parametric Mann–Whitney test.Of the 14 echocardiographs from 14 participants that were selected for the study, 42.8% (6/14) of images were subcostal views while 57.1% (8/14) were 4-chamber views. Eight of the patients had tuberculous effusive constrictive pericarditis while 6 had tuberculous effusive non-constrictive pericarditis. The mean fractal dimension Df was 1.325 with a standard deviation (SD) of 0.146. The measured fibrin strand dimension exceeded the topological dimension in all the images over the entire range of grid scales with a correlation coefficient (r2) greater than 0.8 in the majority. The fractal dimension of echodensities was 1.359?±?0.199 in effusive constrictive pericarditis compared to 1.330?±?0.166 in effusive non-constrictive pericarditis (p?=?0.595).The echocardiographic densities in tuberculous pericardial effusion have a fractal geometrical dimension which is similar in pure effusive and effusive constrictive disease.Echocardiography is used extensively in patients with pericarditis to identify pericardial effusion, and to look for evidence of cardiac t
Maps between moduli spaces of vector bundles and the base locus of the theta divisor
Tawanda Gwena,Montserrat Teixidor i Bigas
Mathematics , 2007,
Abstract: Given a vector bundle $E$ of rank $r$ and degree $d$ on a curve $C$ of genus $g$, one can associate to $E$ in a natural way several other vector bundles. For example, one can take wedge powers of $E$. If $E$ is generated by global sections, the kernel of the evaluation map of sections is again a vector bundle. Also, new vector bundles can be produced by taking elementary transformations centered at a fixed point. Under suitable conditions on degree and rank, these constructions can be carried out globally. While all this processes seem quite elementary, very little is known about the resulting maps. The purpose of this paper is to fill in this gap.
Some examples of vector bundles in the base locus of the generalized theta divisor
Sebastian Casalaina-Martin,Tawanda Gwena,Montserrat Teixidor i Bigas
Mathematics , 2007,
Abstract: This paper shows that on the moduli space of semi-stable vector bundles of fixed rank and determinant (of any degree) on a smooth curve of genus at least two, the base locus of the generalized theta divisor is large provided the rank is sufficiently large. It also shows that the base locus is large for positive multiples of the theta divisor. This work extends results already known for the case where the determinant is of degree zero.
Association of house spraying with suppressed levels of drug resistance in Zimbabwe
Sungano Mharakurwa, Susan L Mutambu, Robert Mudyiradima, Tawanda Chimbadzwa, Steven K Chandiwana, Karen P Day
Malaria Journal , 2004, DOI: 10.1186/1475-2875-3-35
Abstract: Periodic assessments of the therapeutic response of uncomplicated falciparum malaria to chloroquine in two selectively sprayed or unsprayed health centre catchments, from 1995 – 2003. Cross-sectional analysis of in vivo chloroquine failure events for five sites in relation to natural endemicity and spraying history.During selective house spraying, the chloroquine failure rate for the sprayed catchment decreased, such that, after four years, the odds of chloroquine failure were 4× lower than before start of spraying in the area (OR 0.2, 95% CI 0.07 – 0.75, p = 0.010, n = 100). Chloroquine failure odds for the sprayed area became 4× lower than contemporaneous failure odds for the unsprayed area (OR 0.2 95% CI 0.08 – 0.65, p = 0.003, n = 156), although the likelihood of failure was not significantly different for the two catchments before selective spraying started (OR 0.5, 95% CI 0.21 – 1.32; p = 0.170, n = 88). When spraying ended, in 1999, the drug failure odds for the former sprayed area increased back 4 fold by 2003 (OR 4.2, 95%CI 1.49 – 11.78, p = 0.004, n = 146). High altitude areas with naturally lower transmission exhibited a 6× lower likelihood of drug failure than low-lying areas (OR 0.16 95% CI 0.068 – 0.353, -2 log likelihood change 23.239, p < 0.001, n = 465). Compared to sites under ongoing annual spraying, areas that were last sprayed 3–7 years ago experienced a 4-fold higher probability of chloroquine failure (OR 4.1, 95%CI 1.84 – 9.14, -2 log likelihood change 13.956, p < 0.001).Reduced transmission is associated with suppressed levels of resistance to chloroquine and presumably other regimens with multigenic drug resistance. It seems the adoption of transmission control alongside combination chemotherapy is a potent strategy for the future containment of drug-resistant malaria.The escalation of parasite drug resistance has persisted as a major obstacle to malaria control for decades [1-3]. Owing to dwindling options for affordable, safe and effective
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