389 research outputs found
Policy brief, number 9, 2014
[From Introduction] In South Africa, social grants are a central component of government's efforts to alleviate poverty. The number of people receiving social grants has significantly increased in recent years (from about 10.9 million in 2005 to almost 15.7 million in 2013, and an anticipated 16.8 million recipients by 2015).With social grants playing an increasingly important role, a pressing policy issue is whether or not the current social grant schemes are an effective tool for alleviating poverty. Some studies have shown that social grants improve food security (Case and Deaton, 1998; Samson et al., 2008) and in the long run can promote employment through accumulation of human capital and enhancing productivity of poor households (Edmonds et al., 2006; Samson et al., 2008; Surender et al., 2007). However, other studies have reported that social grants have possible disincentive effects on labor market activity, for example, through the relaxing of household budget constraints which may lead to a reduction in labor supply (Bertrand et al., 2003; Ranchorhod, 2006; Klasen and Woolard, 2009). Our study provides new insights by highlighting two key household characteristics, gender and education, in catalyzing or diminishing the effects of grants on household livelihood outcomes. Our analysis mainly focuses on impacts of pensions on household food security and labor supply of household members
Responses of African elephants towards a bee threat: Its application in mitigating human-elephant conflict.
Human settlement expansion into elephant ranges, as well as increasing elephant populations within confined areas has led to heightened levels of human-elephant conflict in southern African communities living near protected areas. Several methods to mitigate this conflict have been suggested including the use of bees as an elephant deterrent. We investigated whether bee auditory and olfactory cues (as surrogates for live bees) could be used to effectively deter elephants. We evaluated the responses of elephants in the southern section of the Kruger National Park to five different treatments: (1) control noise, (2) buzzing bee noise, (3) control noise with honey scent, (4) honey scent, and (5) bee noise with honey scent. Elephants did not respond or displayed less heightened responses to the first four treatments. All elephants exposed to the bee noise with honey scent responded with defensive behaviours and 15 out of 21 individuals also fled. We concluded that buzzing bees or honey scent as isolated treatments (as may be the case with dormant beehives) were not effective elephant deterrents, but rather an active beehive emitting a combination of auditory and olfactory cues was a viable deterrent. However, mismatches in the timing of elephant raids and activity of bees may limit the use of bees in mitigating the prevailing human-elephant conflict.SP201
Socio-economic aspects in draught animal-crop linkages: a diagnostic study of Tsholotsho, Chinyika and Mutoko smallholder farming areas of Zimbabwe
A research paper on Zimbabwe's small-holder farmers' constraints in crop production due to shortages of draught animal power during the 1994/95 agricultural season.A survey was conducted on 451 households in Tsholotsho, Chinyika and Mutoko smallholder areas to understand farmers’ crop production constraints in relation to draught animal power (DAP) during the 1994/95 agricultural season. Farmers without DAP constituted 48.6 percent in the three districts. Of these, 54.5 percent had access to neighbours’ or relatives’ animals. The rest hired or worked in others’ fields in exchange for draught animals. Animal diseases and shortage of grazing land were noted as the major constraints in animal production. Both farmer education and experience as well as household head were found to be associated with district (p<0.001). Tsholotsho had the largest number of farmers (52.8 percent) with more than 10 years experience while Mutoko had the largest proportion (43.3 percent) of Master farmers. Farmer education and experience were found to be independent of sex. The average land holdings per farmer for Tsholotsho, Chinyika and Mutoko were 6.21 ha, 4.22 ha and 1.62 ha, respectively. Tsholotsho is a dryland communal area whilst Chinyika is a relatively wet area. Mutoko is a typical communal area with a high population pressure. Maize is the main crop in Chinyika and Mutoko whilst millet is the most common in Tsholotsho
Assessing the nutritional status of beef cattle: current practices and future prospects
Accurate determination of nutritional and health status of animals is invaluable in modern animalagriculture. Body weights and body condition scoring are the commonly used methods of assessingnutritional status of animals. This paper discusses drawbacks these methods have and highlights thebenefits for using blood metabolites in assessing nutritional status of beef cattle. Blood metabolitelevels indicate the extent of metabolism of energy, proteins and other nutrients in animals. Glucose,cholesterol, non-esterified fatty acids, protein, urea, creatinine, albumin, globulin, minerals, liverenzymes and haematology can be used objectively, reliably and routinely to assess the nutritionalstatus of cattle. In Southern Africa, the use of these metabolites is rare due to lack of equipment forblood analysis and the high cost of analyzing the blood parameters. However, use of high value Ngunicattle in Southern Africa requires the use of blood parameters to accurately assess their nutritionalstatus. Several factors, such as physiological status of an animal, breed, nutrition, season and ageaffect levels of blood metabolites. Combining body weights, body condition scores and bloodmetabolites increase accuracy of assessing the nutritional state and welfare of beef cattle
Differing natural killer cell, T cell and antibody profiles in antiretroviral-naive HIV-1 viraemic controllers with and without protective HLA alleles
Previous work suggests that HIV controllers with protective human leukocyte antigen class I alleles (VC+) possess a high breadth of Gag-specific CD8+ T cell responses, while controllers without protective alleles (VC-) have a different unknown mechanism of control. We aimed to gain further insight into potential mechanisms of control in VC+ and VC-. We studied 15 VC+, 12 VC- and 4 healthy uninfected individuals (UI). CD8+ T cell responses were measured by ELISpot. Flow cytometry was performed to analyse surface markers for activation, maturation, and exhaustion on natural killer (NK) cell and T cells, as well as cytokine secretion from stimulated NK cells. We measured plasma neutralization activity against a panel of 18 Env-pseudotyped viruses using the TZM-bl neutralization assay. We found no significant differences in the magnitude and breadth of CD8+ T cell responses between VC+ and VC-. However, NK cells from VC- had higher levels of activation markers (HLA-DR and CD38) (p = 0.03), and lower cytokine expression (MIP-1β and TNF-α) (p = 0.05 and p = 0.04, respectively) than NK cells from VC+. T cells from VC- had higher levels of activation (CD38 and HLA-DR co-expression) (p = 0.05), as well as a trend towards higher expression of the terminal differentiation marker CD57 (p = 0.09) when compared to VC+. There was no difference in overall neutralization breadth between VC+ and VC- groups, although there was a trend for higher neutralization potency in the VC- group (p = 0.09). Altogether, these results suggest that VC- have a more activated NK cell profile with lower cytokine expression, and a more terminally differentiated and activated T cell profile than VC+. VC- also showed a trend of more potent neutralizing antibody responses that may enhance viral clearance. Further studies are required to understand how these NK, T cell and antibody profiles may contribute to differing mechanisms of control in VC+ and VC-
A digital procurement framework for South African public sector: A content analysis approach
Background:Â Public procurement plays a pivotal role in the South African economy and accounts for a significant portion of public expenditure. The effective management of procurement processes is crucial for ensuring that money is spent wisely and there is an efficient service delivery. However, the paper-based procurement systems have been plagued by inefficiencies.
Objectives:Â To address the challenges of paper-based procurement systems, the study developed a digital procurement framework. The development of a digital procurement framework for the South African public sector represents a strategic response to these challenges and aims to leverage cutting-edge digital technologies to revolutionise the way that the government procures goods and services.
Method:Â The study followed a qualitative research methodology in which content analysis was used to identify themes. Subsequently, a thematic analysis was conducted to formulate the components of the proposed framework. The study facilitated an understanding of the Internet of Things (IoT) and cloud computing.
Results:Â The literature revealed that Industry 4.0 technologies are crucial as they present opportunities which are consistent with legislation like scalability, cost efficiency, collaboration, transparency, accountability and process efficiency.
Conclusion:Â Implementing procurement reforms effectively will result in a public sector procurement system that is responsible, offers value for money and ensures high-quality service delivery.
Contribution: The study contributed to the body of knowledge by providing a guide for a digital procurement of South Africa’s public sector and impact of technology on public procurement
Subtle Longitudinal Alterations in Env Sequence Potentiate Differences in Sensitivity to Broadly Neutralizing Antibodies following Acute HIV-1 Subtype C Infection
Broadly neutralizing antibodies (bNAbs) for HIV-1 prevention or cure strategies must inhibit transmitted/founder and reservoir viruses. Establishing sensitivity of circulating viruses to bNAbs and genetic patterns affecting neutralization variability may guide rational bNAbs selection for clinical development. We analyzed 326 single env genomes from nine individuals followed longitudinally following acute HIV-1 infection, with samples collected at ~1 week after the first detection of plasma viremia; 300 to 1,709 days postinfection but prior to initiating antiretroviral therapy (ART) (median = 724 days); and ~1 year post ART initiation. Sequences were assessed for phylogenetic relatedness, potential N- and O-linked glycosylation, and variable loop lengths (V1 to V5). A total of 43 env amplicons (median = 3 per patient per time point) were cloned into an expression vector and the TZM-bl assay was used to assess the neutralization profiles of 15 bNAbs targeting the CD4 binding site, V1/V2 region, V3 supersite, MPER, gp120/gp41 interface, and fusion peptide. At 1 μg/mL, the neutralization breadths were as follows: VRC07-LS and N6.LS (100%), VRC01 (86%), PGT151 (81%), 10-1074 and PGT121 (80%), and less than 70% for 10E8, 3BNC117, CAP256.VRC26, 4E10, PGDM1400, and N123-VRC34.01. Features associated with low sensitivity to V1/V2 and V3 bNAbs were higher potential glycosylation sites and/or relatively longer V1 and V4 domains, including known "signature" mutations. The study shows significant variability in the breadth and potency of bNAbs against circulating HIV-1 subtype C envelopes. VRC07-LS, N6.LS, VRC01, PGT151, 10-1074, and PGT121 display broad activity against subtype C variants, and major determinants of sensitivity to most bNAbs were within the V1/V4 domains. IMPORTANCE Broadly neutralizing antibodies (bNAbs) have potential clinical utility in HIV-1 prevention and cure strategies. However, bNAbs target diverse epitopes on the HIV-1 envelope and the virus may evolve to evade immune responses. It is therefore important to identify antibodies with broad activity in high prevalence settings, as well as the genetic patterns that may lead to neutralization escape. We investigated 15 bNAbs with diverse biophysical properties that target six epitopes of the HIV-1 Env glycoprotein for their ability to inhibit viruses that initiated infection, viruses circulating in plasma at chronic infection before antiretroviral treatment (ART), or viruses that were archived in the reservoir during ART in subtype C infected individuals in South Africa, a high burden country. We identify the antibodies most likely to be effective for clinical use in this setting and describe mutational patterns associated with neutralization escape from these antibodies
Productivity and efficiency analysis of maize under conservation agriculture in Zimbabwe
This study assesses the productivity and efficiency of maize production under conservation agriculture (CA). The analysis is based on a three year (2008–2010) panel sample of small holder farming households across 15 rural districts in Zimbabwe. We make a comparison of CA with alternative conventional farming methods. Our empirical strategy consists of two methods. First, using a fixed effects model, we estimate maize production functions and derive technical change estimates under CA and conventional farming. Second, we estimate a joint stochastic production frontier to compare productivity and technical efficiency between CA and conventional farming. Under CA, technical progress has been land-saving but seed and fertilizer-using, while it has been land-using but seed-saving in conventional farming. Lastly, the results of the efficiency analysis show that that farmers produce 39% more in CA compared with conventional farming, but technical efficiency levels are essentially equal in both technologies. Overall, the results show significant yield gains in CA practices and significant contributions to food production. CA is land-saving, and this is an important issue for land constrained farmers because they can still have viable food production on smaller area. However, high labor and fertilizer demands in CA present some problems in adoption amongst resource-constrained farmers
Chronic schistosomiasis suppresses HIV-specific responses to DNA-MVA and MVA-gp140 Env vaccine regimens despite antihelminthic treatment and increases helminth-associated pathology in a mouse model
Future HIV vaccines are expected to induce effective Th1 cell-mediated and Env-specific antibody responses that are necessary to offer protective immunity to HIV infection. However, HIV infections are highly prevalent in helminth endemic areas. Helminth infections induce polarised Th2 responses that may impair HIV vaccine-generated Th1 responses. In this study, we tested if Schistosoma mansoni (Sm) infection altered immune responses to SAAVI candidate HIV vaccines (DNA and MVA) and an HIV-1 gp140 Env protein vaccine (gp140) and whether parasite elimination by chemotherapy or the presence of Sm eggs (SmE) in the absence of active infection influenced the immunogenicity of these vaccines. In addition, we evaluated helminth-associated pathology in DNA and MVA vaccination groups. Mice were chronically infected with Sm and vaccinated with DNA+MVA in a prime+boost combination or MVA+gp140 in concurrent combination regimens. Some Sm-infected mice were treated with praziquantel (PZQ) prior to vaccinations. Other mice were inoculated with SmE before receiving vaccinations. Unvaccinated mice without Sm infection or SmE inoculation served as controls. HIV responses were evaluated in the blood and spleen while Sm-associated pathology was evaluated in the livers. Sm-infected mice had significantly lower magnitudes of HIV-specific cellular responses after vaccination with DNA+MVA or MVA+gp140 compared to uninfected control mice. Similarly, gp140 Env-specific antibody responses were significantly lower in vaccinated Sm-infected mice compared to controls. Treatment with PZQ partially restored cellular but not humoral immune responses in vaccinated Sm-infected mice. Gp140 Env-specific antibody responses were attenuated in mice that were inoculated with SmE compared to controls. Lastly, Sm-infected mice that were vaccinated with DNA+MVA displayed exacerbated liver pathology as indicated by larger granulomas and increased hepatosplenomegaly when compared with unvaccinated Sm-infected mice. This study shows that chronic schistosomiasis attenuates both HIV-specific T-cell and antibody responses and parasite elimination by chemotherapy may partially restore cellular but not antibody immunity, with additional data suggesting that the presence of SmE retained in the tissues after antihelminthic therapy contributes to lack of full immune restoration. Our data further suggest that helminthiasis may compromise HIV vaccine safety. Overall, these findings suggested a potential negative impact on future HIV vaccinations by helminthiasis in endemic areas.</p
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