An environmental accounting approach to valuing the services of natural forests and woodlands in Swaziland

Economists and statisticians constructing the national income accounts usually overlook the many benefits derived by communities from natural forests and woodlands. This study attempted to impute a value for the ecosystem services of these resources in Swaziland employing an environmental accounting framework. The current measure of national income was found to underestimate GDP by 2% and under value national savings by 10% by not accounting for the flow and asset values of natural forests and woodlands. The study also revealed a very high dependence of the rural communities in Swaziland on natural forests and woodlands for their livelihoods as they derive more than 50% of the value of total household consumption expenditure from these resources. These results clearly indicate the significant contribution to and crucial role these resources play in the lives and wellbeing of the Swazi people and hence the importance of prudent management and utilisation of this resource sector.Environmental Economics and Policy,

Macroscopic and spectroscopic analysis of lanthanide adsorption to bacterial cells

This study was designed to combine surface complexation modelling of macroscopic adsorption data with X-ray Absorption Spectroscopic (XAS) measurements to identify lanthanide sorption sites on the bacterial surface. The adsorption of selected representatives for light (La and Nd), middle (Sm and Gd) and heavy (Er and Yb) lanthanides was measured as a function of pH, and biomass samples exposed to 4 mg/L lanthanide at pH 3.5 and 6 were analysed using XAS. Surface complexation modelling was consistent with the light lanthanides adsorbing to phosphate sites, whereas the adsorption of middle and heavy lanthanides could be modelled equally well by carboxyl and phosphate sites. The existence of such mixed mode coordination was confirmed by Extended X-ray Absorption Fine Structure (EXAFS) analysis, which was also consistent with adsorption to phosphate sites at low pH, with secondary involvement of carboxyl sites at high adsorption density (high pH). Thus, the two approaches yield broadly consistent information with regard to surface site identity and lanthanide coordination environment. Furthermore, spectroscopic analysis suggests that coordination to phosphate sites is monodentate at the metal/biomass ratios used. Based on the best-fitting pKa site, we infer that the phosphate sites are located on N-acetylglucosamine phosphate, the most likely polymer on gram-negative cells with potential phosphate sites that deprotonate around neutral pH

Bacterial dissolution of fluorapatite as a possible source of elevated dissolved phosphate in the environment

In order to understand the contribution of geogenic phosphorus to lake eutrophication, we have investigated the rate and extent of fluorapatite dissolution in the presence of two common soil bacteria (Pantoea agglomerans and Bacillus megaterium) at T = 25 °C for 26 days. The release of calcium (Ca), phosphorus (P), and rare earth elements (REE) under biotic and abiotic conditions was compared to investigate the effect of microorganism on apatite dissolution. The release of Ca and P was enhanced under the influence of bacteria. Apatite dissolution rates obtained from solution Ca concentration in the biotic reactors increased above error compared with abiotic controls. Chemical analysis of biomass showed that bacteria scavenged Ca, P, and REE during their growth, which lowered their fluid concentrations, leading to apparent lower release rates. The temporal evolution of pH in the reactors reflected the balance of apatite weathering, solution reactions, bacterial metabolism, and potentially secondary precipitation, which was implied in the variety of REE patterns in the biotic and abiotic reactors. Light rare earth elements (LREE) were preferentially adsorbed to cell surfaces, whereas heavy rare earth elements (HREE) were retained in the fluid phase. Decoupling of LREE and HREE could possibly be due to preferential release of HREE from apatite or selective secondary precipitation of LREE enriched phosphates, especially in the presence of bacteria. When corrected for intracellular concentrations, both biotic reactors showed high P and REE release compared with the abiotic control. We speculate that lack of this correction explains the conflicting findings about the role of bacteria in mineral weathering rates. The observation that bacteria enhance the release rate of P and REE from apatite could account for some of the phosphorus burden and metal pollution in aquatic environments

Ethno-veterinary practices amongst livestock farmers in Ngamiland district, Botswana

We carried out a study to determine ethno-veterinary knowledge used to treat and prevent livestock diseases in Toteng Village in Ngamiland District, northwestern Botswana. Primary data were collected through simple random sampling of 45 households in Toteng. Respondents were either livestock owners or cattle herders. Respondents were interviewed using a structured questionnaire which had both open and closed-ended questions. Cattle ownership or herdership in Toteng is an inter-generational occupation with people ranging from 15 to 94 years old. Cattle wereacquired either through inheritance, buying, mafisa (reciprocal exchange) system or government scheme. Women in the study area were more involved in livestock farming activities. Eleven livestock diseases were reported to be prevalent in the study area. The top six diseases were tlhako le molomo -foot and mouth disease (FMD), matlho - eye infections, letshololo-diarrhea, madi -pasteurollosis, mokokomalo - aphosphorisis and pholoso- contagious abortion. At least nine medicinal plant species having ethno-veterinary applications were recorded in the study area. Single plants are mostly used rather than a combination of plants. A number of social strategies were mentioned such as ‘go fetola mafudiso’ - to change grazing areas, and ‘go thaa lesaka’ – to ritualistically ‘protect a kraal’ or livestock against evil spells and predators (lions). Although the intervention of conventional veterinary medicine is pervasive in Toteng,and many livestock owners are resorting to it, there is evidence, however, of generalized ethno-veterinary knowledge used to treat and prevent livestock diseases. Local farmers and their herders in Ngamiland are not only knowledgeable and experienced in treating a range of livestock diseases, but also in performing other veterinary tasks such as assisting in births, treating fractures and range management strategies to mitigate particular threats from their local environment. The efficacy of ethno-veterinary knowledge for preventing and treating livestock diseases andrange management strategies identified in this study need to be fully investigated and integrated in veterinary extension services.Key words: Okavango Delta, ethnoveterinary medicine, livestock diseases, indigenous Knowledge, traditional medicinal Plants, ethnodiagnostic skills

An isotopic study of the Palata Creek watershed, Lubombo area, eastern Swaziland.

The main objective of this investigation was to examine storm runoff generation in the Palata Creek watershed in eastern Swaziland. Specifically, a suite of natural isotopic, chemical and hydrometric methods were used to assess groundwater contributions to storm runoff. The Palata Creek watershed drains an area of 6.35 km\sp2. It is underlain by a massive rhyolite formation which is locally weathered. The average hydraulic conductivity of the weathered rhyolite as determined from single well tests in shallow wells is 1.0\times 10\sp{-7} m/s. Soils in the catchment are generally thin, and range from sandy to silty clay. During this research, the study area and the whole of southern Africa were affected by the worst drought in years. There were only three significant rainfall events in the catchment during this study. Oxygen-18 concentrations in rainfall, baseflow and stormflow, as well as hydrometric data were used to determine groundwater contributions to storm runoff in the catchment. Baseflow chemistry and isotopic composition matched that of shallow groundwater. The variability in the oxygen-18 content between rainfall events was large and it generated small but significant fluctuations in the stream isotopic composition. Both the chloride and electrical conductivity data in the baseflow and shallow groundwater showed no dilution by the rain water. Intact, a flushing effect occurred in which the electrical conductivity and chloride increased during the hydrograph rise. This type of flushing effect made chloride and electrical conductivity unsuitable as natural tracers for the mass balance hydrograph separation. (Abstract shortened by UMI.)Dept. of Geology and Geological Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1993 .N594. Source: Masters Abstracts International, Volume: 32-02, page: 0568. Adviser: M. G. Sklash. Thesis (M.Sc.)--University of Windsor (Canada), 1993

An investigation into the improvement in WCDMA system performance using multiuser detection and interference cancellation

WCDMA is typically characterised as a system capable of providing mobile users with data rates up to 2 Mb/s and beyond. It has been termed an ultra high-speed, ultra high-capacity radio technology that will be able to carry a new range of fast, colourful media, such as colour graphics, video, animations, digital audio, Internet and e-mail that consumers will be able to access over their mobiles devices. This current study has researched on the various existing Multiuser detection (MUD) processes or proposals conducted by various research institutions around the world. It has identified the advantages that the past work offers, and it is these advantages that form the basis of the current research into the improvement techniques. The proposed Partial Parallel Pipelined Multiuser Detector (PPPMUD or P3MUD) has come about from two main flavours or directions of research. The first one seeks to promote the Soft Parallel Interference Cancellation technique as an effective bias mitigation technique. This bias occurring in the second stage decision statistics, exhibits a very harmful effect on system Bit Error Rate, (BER), particularly for large system loads. This current study goes further by carefully analysing the Soft Cancellation Factor, SCF behaviour to eventually derive and determine the optimum SCF value which exhibits positive characteristics when varied with the increasing system load (number of users). This optimum SCF value is called the universal SCF or SCFUNV, as it is theoretically supposed to perform favourably under various system loads. A favourable or acceptable performance would be characterised by low observed or measured BER during the system processing stages. A further enhancement to the operational performance of the SCFUNV algorithm is the SCFUNV Compensator, which is basically a compensation mechanism created by modelling the behaviour of the SCF values, and adjusts the SCFUNV depending on the system load, (number of simultaneous users). Thus, the SCFUNV is adaptively adjusted in order to perform acceptably under all load conditions. The second direction of research, as regards improvements in MUD techniques, involves the conventional Bit-Streaming, Pipelined Multiuser Detector. This came about due to the computational complexity as well as matrix inversions which affected earlier asynchronous multiuser detection techniques. This detector has a pipelined architecture which avoids multishot (block-based) detection and instead, processes the bits in a streaming fashion. The architecture consists of a matched filter followed by three stages of parallel interference cancellation, (PIC). This present study extends that research by outlining the advantages of incorporating the soft parallel interference cancellation technique, by way of the universal soft cancellation factor, (SCFUNV), into the conventional pipelined multiuser detector architecture to form the P3MUD architecture, which includes the compensator. The contributions of the proposed P3MUD system is that the observed BER output simulations are promising, with an observed overall decrease in the error rate for the P3MUD process, as compared to the conventional pipelined detection method. This decrease signifies an improvement offered by the proposed (P3MUD) algorithm. Further observed analysis indicates the possibility of decreasing the number of parallel interference cancellation stages from three to at least two, after the matched filter detection stage, without an observable change in system BER. Hence, the proposal of the two-stage P3MUD.Dissertation (MEng (Electronic))--University of Pretoria, 2006.Electrical, Electronic and Computer Engineeringunrestricte

Factors contributing to the foster care backlog : service providers’ perspectives and suggestions

The backlog in foster care applications has been an issue in the Department of Health and Social Development, Johannesburg office, for the last number of years, resulting in foster care placement applications accumulating and families’ quality of life being affected and compromised. The service providers are inundated with high caseloads. Foster care applications could take up to a year or longer before they are processed and finalised at the Children’s Court. The aim of the study was to explore and describe the factors contributing to the foster care backlog from the service providers’ perspective and to provide suggestions to address this continuing backlog. The researcher employed a qualitative research approach and an explorative, descriptive and contextual research design. Factors such as high caseloads, lack of resources and lack of support and training from management were identified as contributing to the backlog. Recommendations made are the immediate filling of vacant posts, induction of new social workers, provision of adequate resources and infrastructure as well as the division of foster care services.Social WorkM.A. (Mental Health

Reducing the Competition: A Dual-Purpose Ionic Liquid for the Extraction of Gallium from Iron Chloride Solutions

The separation of gallium from iron by solvent extraction from chloride media is challenging because the anionic chloridometalates, FeCl4− and GaCl4−, display similar chemical properties. However, we report here that the selective separation of gallium from iron in HCl solution can be achieved using the dual-purpose ionic liquid methyltrioctylammonium iodide in a solvent extraction process. In this case, the reduction of Fe3+ to Fe2+ by the iodide counterion was found to inhibit Fe transport, facilitating quantitative Ga extraction by the ionic liquid with minimal Fe extraction from 2 M HCl

Spatial heterogeneity in projected leprosy trends in India

Background: Leprosy is caused by infection with Mycobacterium leprae and is characterized by peripheral nerve damage and skin lesions. The disease is classified into paucibacillary (PB) and multibacillary (MB) leprosy. The 2012 London Declaration formulated the following targets for leprosy control: (1) global interruption of transmission or elimination by 2020, and (2) reduction of grade-2 disabilities in newly detected cases to below 1 per million population at a global level by 2020. Leprosy is treatable, but diagnosis, access to treatment and treatment adherence (all necessary to curtail transmission) represent major challenges. Globally, new case detection rates for leprosy have remained fairly stable in the past decade, with India responsible for more than half of cases reported annually. Methods: We analyzed publicly available data from the Indian Ministry of Health and Family Welfare, and fit linear mixed-effects regression models to leprosy case detection trends reported at the district level. We assessed correlation of the new district-level case detection rate for leprosy with several state-level regressors: TB incidence, BCG coverage, fraction of cases exhibiting grade 2 disability at diagnosis, fraction of cases in children, and fraction multibacillary. Results: Our analyses suggest an endemic disease in very slow decline, with substantial spatial heterogeneity at both district and state levels. Enhanced active case finding was associated with a higher case detection rate. Conclusions: Trend analysis of reported new detection rates from India does not support a thesis of rapid progress in leprosy control