51 research outputs found

    Classification of Plants According to Their Heavy Metal Content around North Mara Gold Mine, Tanzania: Implication for Phytoremediation

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    Plants like other living organisms respond differently under different environmental conditions. An elevated level of heavy metals is one of the stresses which results into three classes of plants depending on their heavy metal content. The classes of plant species according to their accumulated heavy metals around North Mara Gold Mine were not known. To study such classes, a line transect of 700m long was established opposite the gold mine wastes. A total of eight sampling points were systematically established each after every 100m in that transect. Fifteen plant species were sampled; at least one species per sampling point. Approximately 5g of the root and shoot portions of the plants were separately collected from each plant. Three soil samples were also collected at each sampling point where vegetations were previously sampled. The soils and vegetations were analyzed for heavy metals (copper, lead, chromium, zinc, cadmium and nickel) by AAS. Of 15 plant species; 10, 6, 6 were hyperaccumulators, excluders and indicators for heavy metals respectively. Detailed studies on the agronomical requirements, optimizations, growth rates and the incidence of pests and diseases are required on the identified heavy metal hyperaccumulator plants for possible future remediation of the study area.Tanz. J. Sci. Vol. 37 2011, 109-11

    Plant Morphoecological Traits, Grass-Weed Interactions and Water Use Efficiencies of Grasses Used for Restoration of African Rangelands

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    Degradation characterized by depleted vegetation cover is a serious environmental problem in African rangelands. It poses a serious threat to millions of pastoralists and agropastoralists who depend on livestock as a source of livelihood. Consequently, there has been a growing global interest to consolidate efforts to restore degraded ecosystems. For example, the UN decade of Ecosystem Restoration initiative aims at uniting the world behind a common goal of preventing, halting and reversing the degradation of ecosystems. Grass reseeding using native perennial species has been identified as one of the practical ecological strategies for restoring degraded African rangelands, enhancing vegetation cover and forage production. Knowledge of the multifaceted performance of African rangeland grasses in terms of morphoecological traits, interaction with weeds and water use efficiencies is however largely limited and often elusive. Perennial grasses indigenous to African rangelands Cenchrus ciliaris L. (African foxtail grass), Enteropogon macrostachyus (Hochst. Ex A. Rich.) Monro ex Benth. (Bush rye grass) and Eragrostis superba Peyr. (Maasai love grass), were established in an African semi-arid rangeland under natural conditions to fill this knowledge gap. Morphoecological plant traits: aboveground biomass (shoot, leaf and stem) production, plant densities, basal cover, tiller densities and plant height were measured 9 months after establishment. Interaction between the target grass species and weeds and water use efficiencies (WUE) were also determined. Enteropogon macrostachyus displayed significantly higher values for plant densities, tiller densities and basal cover, indices commonly used to estimate the potential of grasses for ecological restoration. Eragrostis superba produced the highest shoot biomass and water use efficiencies. This is attributed to its higher leafy biomass fraction. Higher aboveground biomass production of E. superba demonstrate its suitability for enhancing rangeland productivity. Cenchrus ciliaris suppressed the weeds. This is linked to its aggressive and allelopathic nature. In conclusion, the three perennial grasses displayed distinct morphoecological traits. In order to achieve successful seed-based restoration of degraded African rangelands using native perennial grasses, careful selection species to maximize on their unique traits is recommended. Ultimately, this selection process should match the desired restoration outcomes and subsequent use of the rangeland.Peer reviewe

    Combining Rainwater Harvesting and Grass Reseeding to Revegetate Denuded African Semi-arid Landscapes

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    In African drylands, perennial grasses preferred by grazing livestock are disappearing at an alarming rate. This has led to recurrent livestock feed shortages threatening pastoralist’s livelihoods. Combining native grass reseeding and rainwater harvesting offers a viable and innovative solution to reverse this trend. However, studies to determine how biomass yields are affected by soil moisture availability attributed to in situ rainwater harvesting in African drylands are limited. We investigated how biomass yields of three grasses native to Africa, i.e., Enteropogon macrostachyus (Bush rye grass), Cenchrus ciliaris (African foxtail grass), and Eragrostis superba (Maasai love grass), are affected by soil moisture content in a typical semi-arid landscape. Rainwater harvesting structures included trenches, micro-catchments and furrows. Additionally, rain runoff was diverted from an adjacent road used as a catchment area. Soil moisture was measured between November 2018 and August 2019 using PlantCare Mini-Logger sensors installed at 40 and 50 cm depths and 0, 1, 5 and 15 m away from the trench. Quadrat method was used to determine biomass yields in August 2019. Peaks in soil moisture were observed after rainfall events. Soil moisture content gradually decreased after the rainy season, but was higher closer to the trench. This is attributed to the prolonged rainwater retention in the trenches. Biomass yields were in the order Eragrostis superba > Cenchrus ciliaris > Enteropogon macrostachyus. Biomass production was higher near the trenches for all the studied species. Sensitivity to soil moisture demonstrated by the magnitude to yield reduction during the growing season was in the order Eragrostis superba > Cenchrus ciliaris > Enteropogon macrostachyus. These results suggest that Eragrostis superba is more sensitive to drought stress than Enteropogon macrostachyus that is adapted to a wide range of soil moisture conditions. We demonstrated that in situ rainwater harvesting structures enhanced soil moisture availability and displayed great potential for revegetating denuded natural rangelands in semi-arid African landscapes. Thus, combining rainwater harvesting and reseeding techniques can produce measurable improvements in pastoral livelihoods and should be incorporated in dryland development policies in the region. Ultimately, incorporating such innovative strategies can strengthen the effectiveness of ecological restoration in African drylands to meet the objectives of the UN Decade on Ecosystem Restoration and achieving the UN Sustainable Development Goals.Peer reviewe

    Dry matter yields and hydrological properties of three perennial grasses of a semi-arid environment in east Africa

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    Enteropogon macrostachyus (Bush rye), Cenchrus ciliaris L. (African foxtail grass) and Eragrostis superba Peyr (Maasai love grass) are important perennial rangeland grasses in Kenya. They provide an important source of forage for domestic livestock and wild ungulates. These grasses have been used extensively to rehabilitate denuded patches in semi-arid environment of Kenya. This study investigated the dry matter yields and hydrological properties of the three grasses under simulated rainfall at three phenological stages; early growth, elongation and reproduction. Laboratory seed viability tests were also done. Hydrological properties of the three grasses were estimated using a Kamphorst rainfall simulator. Results showed that there was a significant difference (p > 0.05) in dry matter yields and soil hydrological properties at the different grass phenological stages. Generally, all the three grasses improved the soil hydrological properties with an increase in grass stubble height. C. ciliaris gave the best soil hydrological properties followed by E. macrostachyus and E. superba, respectively. E. macrostachyus recorded the highest seed viability percentage. C. ciliaris and E. superba were ranked second and third, respectively. C. ciliaris yielded the highest biomass production at the reproductive stage followed by E. superba and E. macrostachyus, respectively. (Résumé d'auteur

    Feasibility and acceptability of the smart pillbox and medication label with differentiated care to support person-centered tuberculosis care among ASCENT trial participants - A multicountry study.

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    INTRODUCTION: Digital adherence technologies (DATs) can offer alternative approaches to support tuberculosis treatment medication adherence. Evidence on their feasibility and acceptability in high TB burden settings is limited. We conducted a cross-sectional survey among adults with drug-sensitive tuberculosis (DS-TB), participating in pragmatic cluster-randomized trials for the Adherence Support Coalition to End TB project in Ethiopia (PACTR202008776694999), the Philippines, South Africa and Tanzania (ISRCTN 17706019). METHODS: From each country we selected 10 health facilities implementing the DAT intervention (smart pillbox or medication labels, with differentiated care support), ensuring inclusion of urban/rural and public/private facilities. Adults on DS-TB regimen using a DAT were randomly selected from each facility. Feasibility of the DATs was assessed using a standardized tool. Acceptability was measured using a 5-point Likert-scale, using the Capability, Opportunity, Motivation, Behavior (COM-B) model. Mean scores of Likert-scale responses within each COM-B category were estimated, adjusted for facility-level clustering. Data were summarized by country and DAT type. RESULTS: Participants using either the pillbox (n = 210) or labels (n = 169) were surveyed. Among pillbox users, phone ownership (79%), use of pillbox reminders (87%) and taking treatment without the pillbox (22%) varied by country. Among label users, phone ownership (81%), paying extra to use the labels (8%) and taking treatment without using labels (41%) varied by country. Poor network, problems with phone charging and access, not having the pillbox and forgetting to send text were reasons for not using DATs. Overall, people with TB had a favorable impression of both DATs, with mean composite scores between 4·21 to 4·42 across COM-B categories. Some disclosure concerns were reported. CONCLUSION: From client-perspective, pillboxes and medication labels with differentiated care support were feasible to implement and acceptable in variety of settings. However, implementation challenges related to network, phone access, stigma, additional costs to people with TB to use DATs need to be addressed

    Multi‐stakeholder participation for successful implementation of applied research projects in Africa

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    Rainwater harvesting from Roads For Indigenous Pasture production and improved rural livelihoods in Kitui, Kenya (ROFIP) is an applied research project. It assessed the potential of combining multiple sustainable land management practices, for example native grass reseeding, rainwater harvesting from roads and in situ microcatchments to enhance vegetation cover in a semi-arid dryland in Kenya. Rural earth roads were used as a catchment. Runoff generated from rainfall events was diverted into reseeded pastures with trenches established at intervals, across a slope. The ROFIP project also integrated microcatchments created using ox-driven ploughs, a traditional practice for seedbed preparation and harnessing in situ rainwater harvesting in African drylands. Combining the diversion of runoff from roads and harvesting rainwater in situ improves and prolongs soil moisture availability in reseeded pastures. Consequently, this translated to higher biomass yields (i.e. forage for livestock) and vegetation cover (land degradation mitigation and enhanced soil health). This project clearly showed that combining rainwater harvesting and native pasture reseeding improves water retention and soil health, thus improving sustainable pasture production. However, for this to be achieved, it is prudent to involve practitioners to co-design practical solutions that are socially, economically and environmentally sustainable. Multi-stakeholder engagement, effective knowledge sharing, and community involvement can be major enablers in the pursuit of environmental and socioeconomic relevant benefits in applied research projects in Africa. This approach enhances a sense of shared purpose among practitioners and empowers them to become points of reference to their peers

    A cluster randomised controlled trial of the community effectiveness of two interventions in rural Malawi to improve health care and to reduce maternal, newborn and infant mortality

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    <p>Abstract</p> <p>Background</p> <p>The UN Millennium Development Goals call for substantial reductions in maternal and child mortality, to be achieved through reductions in morbidity and mortality during pregnancy, delivery, postpartum and early childhood. The MaiMwana Project aims to test community-based interventions that tackle maternal and child health problems through increasing awareness and local action.</p> <p>Methods/Design</p> <p>This study uses a two-by-two factorial cluster-randomised controlled trial design to test the impact of two interventions. The impact of a community mobilisation intervention run through women's groups, on home care, health care-seeking behaviours and maternal and infant mortality, will be tested. The impact of a volunteer-led infant feeding and care support intervention, on rates of exclusive breastfeeding, uptake of HIV-prevention services and infant mortality, will also be tested. The women's group intervention will employ local female facilitators to guide women's groups through a four-phase cycle of problem identification and prioritisation, strategy identification, implementation and evaluation. Meetings will be held monthly at village level. The infant feeding intervention will select local volunteers to provide advice and support for breastfeeding, birth preparedness, newborn care and immunisation. They will visit pregnant and new mothers in their homes five times during and after pregnancy.</p> <p>The unit of intervention allocation will be clusters of rural villages of 2500-4000 population. 48 clusters have been defined and randomly allocated to either women's groups only, infant feeding support only, both interventions, or no intervention. Study villages are surrounded by 'buffer areas' of non-study villages to reduce contamination between intervention and control areas. Outcome indicators will be measured through a demographic surveillance system. Primary outcomes will be maternal, infant, neonatal and perinatal mortality for the women's group intervention, and exclusive breastfeeding rates and infant mortality for the infant feeding intervention.</p> <p>Structured interviews will be conducted with mothers one-month and six-months after birth to collect detailed quantitative data on care practices and health-care-seeking. Further qualitative, quantitative and economic data will be collected for process and economic evaluations.</p> <p>Trial registration</p> <p>ISRCTN06477126</p

    Author Correction: Drivers of seedling establishment success in dryland restoration efforts

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    1 Pág. Correción errata.In the version of this Article originally published, the surname of author Tina Parkhurst was incorrectly written as Schroeder. This has now been corrected.Peer reviewe
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