Biomedical subjects

Tim Robinson

Publications and source records attributed to Tim Robinson.

6 recordsLinked to original sources

PubMed2006

GIS and multiple-criteria evaluation for the optimisation of tsetse fly eradication programmes.

Tsetse flies are the vectors of trypanosomes, the causal agent of trypanosomiasis, a widespread disease of livestock and people in Africa. Control of tsetse may open vast areas of land to livestock-keeping, with the associated benefits of developing mixed crop-livestock production systems. However, as well as possible positive impacts there are also risks: bush clearing would accelerate and cattle numbers would rise, leading to a reduction of vegetation cover, and an increase in runoff and erosion; there may also be increased pressure on conserved areas and reductions in biodiversity. The objective of this study is to show how remotely sensed and other environmental data can be combined in a decision support system to help inform tsetse control programmes in a manner that could be used to limit possible detrimental effects of tsetse control. For Zambia, a methodology is developed that combines a tree-based decision-support approach with the use of Multiple-Criteria Evaluation (MCE), within a Geographical Information System (GIS), in order to target areas for tsetse control. The results show clear differentiation of priority areas under a series of hypothetical scenarios, and some areas (e.g. northwest of Petauke in the Eastern Province of Zambia) are consistently flagged as high priority for control. It is also demonstrated that priority areas do not comprise isolated tsetse populations, meaning that disease control using an integrated approach is likely to be more economically viable than local eradication.

Animals↗

PubMed2006

Indicators of mortality in African adults with malaria.

Malaria is a major cause of morbidity and mortality amongst adults in sub-Saharan Africa, but descriptions of symptoms and mortality in this group have received little attention in the past. A retrospective study was performed on adults admitted to a tertiary hospital in Tanzania with a primary diagnosis of malaria. Frequency and mortality for the criteria in the WHO definition of severe malaria were recorded. Logistic regression analysis was then used to identify symptoms with the greatest prognostic value. Two hundred and sixty-nine adults (median age 28 years) with a primary diagnosis of malaria were studied, with an overall mortality rate of 15.2%. Logistic regression identified three key prognostic indicators: unconsciousness (odds ratio (OR) 44.44; 95% CI 4.05-488.24), renal failure (OR 7.37; 95% CI 1.70-31.96) and pulmonary oedema (OR 13.83; 95% CI 3.52-54.32). Whilst the WHO criteria predicted all of the 41 adults who died, 37 (90.2%) had at least one of the following symptoms: unconsciousness (n=39, fatality rate 74.4%), renal failure (n=26, fatality rate 66.7%) and pulmonary oedema (n=28, fatality rate 64.3%). These symptoms can therefore identify those at a high risk of death in African adults with malaria.

Adult↗

PubMed2006

Bacterial diversity is determined by volume in membrane bioreactors.

It has been proposed that established models and theories developed in classical ecology could be employed to greatly improve the optimization of wastewater treatment plants (WWTP) by placing the microbiological component onto a model-predictive basis. In particular, this could be achieved by better understanding bacterial community assembly and development. The species-area relationship is one of the oldest biological laws and has been used to describe spatial diversity patterns in contiguous habitats and on islands. In the current study, bacterial communities in seven membrane bioreactors (MBR), of increasing size, located across the UK were sampled. A significant linear relationship between bacterial taxa richness and reactor size was observed and was similar to classical species-area relationships of larger organisms colonizing oceanic islands. Rank-abundance plots revealed a gradient of greater evenness in community structure as MBR volume increased. Application of the Raup and Crick probability-based similarity index indicated a strong role for dispersal in MBR colonization and community structure. Our findings demonstrate that the MBR sampled behaved like islands with respect to bacterial colonization in accordance with the theory of island biogeography. In addition this study provides further evidence that biodiversity at the bacterial level is more similar to that of animals and plants than previously postulated.

Bacteria↗

PubMed2005

Using remote sensing and geographic information systems to identify villages at high risk for rhodesiense sleeping sickness in Uganda.

Geographic information systems (GIS) and remote sensing were used to identify villages at high risk for sleeping sickness, as defined by reported incidence. Landsat Enhanced Thematic Mapper (ETM) satellite data were classified to obtain a map of land cover, and the Normalised Difference Vegetation Index (NDVI) and Landsat band 5 were derived as unclassified measures of vegetation density and soil moisture, respectively. GIS functions were used to determine the areas of land cover types and mean NDVI and band 5 values within 1.5 km radii of 389 villages where sleeping sickness incidence had been estimated. Analysis using backward binary logistic regression found proximity to swampland and low population density to be predictive of reported sleeping sickness presence, with distance to the sleeping sickness hospital as an important confounding variable. These findings demonstrate the potential of remote sensing and GIS to characterize village-level risk of sleeping sickness in endemic regions.

Animals↗

PubMed2003

Predicting sediment toxicity using logistic regression: a concentration-addition approach.

The question posed in this article is how useful the chemical concentration measurements for predicting the outcome of sediment toxicity tests are. Using matched data on sediment toxicity and sediment chemical concentrations from a number of studies, we investigated several approaches for predicting toxicity based on multiple logistic regression with concentration-addition models. Three models were found to meet criteria for acceptability. The first model uses individual chemicals selected using stepwise selection. The second uses derived variables to reflect combined metal contamination, polycyclic aromatic hydrocarbon (PAH) contamination, and the interaction between metals and PAHs. The third and final model is a separate species model with derived variables. Overall, these models suggest that toxicity may be correctly predicted approximately 77% of the time, although prediction is better for samples identified as nontoxic than for those known to be toxic.

Animals↗

PubMed2002

Studies on the removal of dyes from a synthetic textile effluent using barley husk in static-batch mode and in a continuous flow, packed-bed, reactor.

The adsorption of five reactive dyes in a synthetic textile dye effluent onto barley husks has been studied in static-batch mode and in a continuous flow, packed-bed, reactor (CFPBR). Effective adsorption, thermodynamics and various initial concentrations (C0) were studied for static batch conditions. The effect of C0 and retention time (r), by varying height and weight of packing, along with the kinetics of dye adsorption in CFPBR, were studied. The Langmuir isotherm was used to predict saturation capacities. The barley husks were found to remove 8 mg g(-1) of dyes at C0 100 mg l(-1) in CFPBR with a residence of 11 min, with 90% adsorption being achieved.

Adsorption↗