23 research outputs found
Restoration of soil quality using biochar and brown coal waste: A review
Soils in intensively farmed areas of the world are prone to degradation. Amendment of such soils with organic waste materials attempts to restore soil quality. Organic amendments are heterogeneous media, which are a source of soil organic matter (SOM) and maintain or restore chemical, physical, biological and ecological functionality. More specifically, an increase in SOM can influence the soil microclimate, microbial community structure, biomass turnover and mineralisation of nutrients. The search is on-going for locally sourced alternatives as many forms may be costly or geographically limiting. The present review focuses on a heterogeneous group of amendments i.e. biochar and brown coal waste (BCW). Both biochar (made from a variety of feedstocks at various temperatures) and BCW (mined extensively) are options that have worldwide applicability.
These materials have very high C contents and soil stability, therefore can be used for long-term C sequestration to abate greenhouse gas emissions and as conditioners to improve soil quality. However, biochar is costly for large-scale applications and BCW may have inherently high moisture and pollutant contents. Future studies should focus on the long-term application of these amendments and determine the physicochemical properties of the soil, bioavailability of soil contaminants, diversity of soil communities and productivity of selected crops. Furthermore, the development of in situ technologies to lower production and processing costs of biochar and BCW would improve their economic feasibility for large-scale application
The acceptability and effectiveness of a polyester drinking-water filter in a dracunculiasis-endemic village in northern region, Ghana.
In the global effort to eradicate dracunculiasis (guinea-worm disease) one of the main tools is the use of filters for filtering unsafe drinking-water. The expensive and high-quality monofilament nylon filters, which for many years were donated to all dracunculiasis-endemic countries, are now mainly reserved for highly endemic countries. Polyester cloth is less expensive, and we investigated the user acceptability and effectiveness of this material as a drinking-water filter in a dracunculiasis-endemic village in Northern Region, Ghana, over a 3-month period. The polyester cloth completely retained the stages of copepods that are responsible for transmitting dracunculiasis. Over the 3-month study period a majority of respondents found that the new cloth was superior to the nylon filter with regard to strength (83%), filtering time (80%), and the ease with which the filter could be cleaned (87%). Inspection revealed that the filters were used intensively and that the new cloth was damaged after 2-3 months of use, which is also the case for the monofilament nylon filters
Large-Scale Surveillance of Plasmodium falciparum crt(K76T) in Northern Ghana▿
Surveillance of Plasmodium falciparum crt(K76T) [Pfcrt(K76T)], a resistance marker of chloroquine and, limitedly, amodiaquine, in >4,000 children in northern Ghana revealed a prevalence of 79%. Pfcrt(K76T) was heterogeneously distributed and associated with chloroquine use, low parasitemia, and the dry season. Widespread chloroquine resistance challenges the regional life span of amodiaquine as a partner drug in artemisinin combination therapy
High residual chloroquine blood levels in African children with severe malaria seeking healthcare
Despite widespread resistance, chloroquine remains widely used in West Africa, particularly in home treatment. We examined chloroquine blood levels on admission to a referral hospital with respect to the manifestation of severe malaria in 290 Ghanaian children. Of the patients, 78% exhibited chloroquine concentrations (subtherapeutic, 35%; therapeutic, 37%; supratherapeutic, 6%) and 11% died. Most parasites (78%) carried the pfcrt-T76 chloroquine resistance mutation. High drug concentrations correlated with reduced parasitaemia but also with selection of resistant parasites, lower respiratory and heart rates, increased plasma lactate levels and impaired consciousness. Geometric mean chloroquine concentrations tended to be higher in children who died than in survivors (1.135 vs. 778nmol/l; P=0.09). Supratherapeutic drug levels (>5000nmol/l) were associated with fatal outcome (odds ratio 8.6; 95% CI 1.4-51.7). Residual chloroquine concentrations were found to be abundant in children with severe malaria and to be associated with alterations in the clinical manifestation of the disease and its case fatality. This may result from toxic effects of the drug and/or reflect preceding overtreatment in children with acute life-threatening disease. In areas of intense chloroquine resistance and frequent pre-treatment, additional administration of chloroquine at hospital admission is not only ineffective but may even further endanger patient