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BackgroundTemporary lower limb immobilisation following injury is a risk factor for symptomatic venous thromboembolism (VTE). Pharmacological thromboprophylaxis can mitigate this risk but it is unclear which patients benefit from this intervention. The Aberdeen VTE risk tool was developed to tailor thromboprophylaxis decisions in these patients and this evaluation aimed to describe its performance in clinical practice. Secondarily, diagnostic metrics were compared with other risk assessment methods (RAMs).MethodsA prospective cohort service evaluation was conducted. Adult patients (≥16 years) managed with lower limb immobilisation for injury who were evaluated with the Aberdeen VTE risk tool prior to discharge from the ED were identified contemporaneously between February 2014 and December 2020. Electronic patient records were scrutinised up to 3 months after removal of immobilisation for the development of symptomatic VTE or sudden death due to pulmonary embolism (PE). Other RAMs, including the Thrombosis Risk Prediction for Patients with cast immobilisation (TRiP(cast)) and Plymouth scores, were assimilated retrospectively and diagnostic performance compared.ResultsOf 1763 patients (mean age 46 (SD 18) years, 51% women), 15 (0.85%, 95% CI 0.52% to 1.40%) suffered a symptomatic VTE or death due to PE. The Aberdeen VTE tool identified 1053 (59.7%) patients for thromboprophylaxis with a sensitivity of 80.0% (95% CI 54.8% to 93.0%) and specificity of 40.4% (95% CI 38.1% to 42.6%) for the primary outcome. In 1695 patients, fewer were identified as high risk by the TRiP(cast) (33.3%) and Plymouth (24.4%) scores, but with greater specificity, 67.0% and 75.6%, respectively, than dichotomous RAMs, including the Aberdeen VTE tool.ConclusionRoutine use of the Aberdeen VTE tool in our population resulted in an incidence of symptomatic VTE of less than 1%. Ordinal RAMs, such as the TRiP(cast) score, may more accurately reflect VTE risk and permit more individually tailored thromboprophylaxis decisions but prospective comparison is needed.

The kinetics of reaction between oxides of nitrogen, ammonia, water vapour and oxygen in ppm quantities in nitrogen were studied. The kinetics of the nitrogen dioxide-ammonia reaction and of the nitrogen dioxide-water reaction were investigated separately, and a reaction model was developed to predict the rate of disappearance of nitrogen dioxide in the overall reaction system based on the reaction rate expressions deduced for the separate reactions. There was satisfactory agreement between measured and predicted dioxide concentrations as a function of time. The results have relevance to consideration of clean-up processes of tail gases in nitric acid plants and to studies of reactions in polluted atmospheres.

The formation of ammonium nitrate in a reaction system containing oxides of nitrogen, ammonia, water vapour and oxygen present in ppm quantities in nitrogen was investigated. The measured amounts of nitrate produced were compared with those predicted by use of a kinetic model for the reacting system. For any temperature there was an initial pressure of ammonia below which nitrate was not found. This pressure was determined solely by thermodynamic considerations. At higher pressures of nitrogen dioxide, equilibrium was quickly attained, but at low pressures nitrate was not always formed in the time of contact of reactants. Water vapour enhanced the rate of formation of nitrate. The work has relevance to the possibility of formation of ammonium nitrate in nitric acid plants and to its formation in the atmosphere.

A study was undertaken to remove colour from a kraft mill's treated effluent in Kenya and determine the suitability of phosphate rock to replace wood ash during the electrochemical process. The electrochemical method alone, electrochemical combined with alum (ELCAL), wood ash leachate (ELCAS) and phosphate rock (ELPHOS) solutions at a rate of 165 to 1,000 g/m3 were tested. Effluent characteristics were determined after complete removal of colour. Same reduction rates of TS (85%) and TSS (89%) were recorded by ELCAS and ELPHOS. However, ELPHOS removed more COD (86 to 91%) and more BOD (85 to 92%) than ELCAS. Furthermore, the pH of ELPHOS treated solution was 9.3, within the Kenya Local Government's allowable limit. Power reduction with ELCAS and ELPHOS varied between 53 to 73% and 49 to 69% respectively but the difference was not statistically significant. Overnight aeration further improved the quality of ELCAS and ELPHOS treated effluent, reducing BOD and COD values to 0 mg/l. ELPHOS cost ($0.29/m3) was nevertheless three times higher than that of ELCAS ($0.10/m3), mainly because of free wood ash. ELPHOS did not also increase effluent phosphorus. It was therefore recommended that various ways be explored in making ELPHOS more economical to replace ELCAS.

Occupational environmental health associated with both industrial and domestic sewage reuse for food production in Athi River town Kenya has been studied. The levels of toxic heavy metals such as lead, cadmium, selenium and arsenic in the soil, roof crops, leaf crops and fruits (or seed) were determined using atomic absorption spectoscophy (AAS). In soils the average levels of lead and cadmium were 0.44mg/g and 0.13mg/g respectively. The crops analysed were selected as root crops, leaf crops and fruits (or seed) crops. The levels of lead found in these crops were 0.06 μg/g, 0.01 μg/g and fruit 0.05 μg/g for root, leaf and fruit crops respectively. Similarly, the cadmium in root, leaf and fruit crops was 0.016 μg/g, 0.03 μg/g and 0.02 μg/g respectively. Coliform counts were greater than 300 counts per 100ml in all samples, which gave a positive indication of the presence of Escherichia coli.

A study was undertaken on the combined wastewater effluent from a Tannin extract plant (90%) and a Mushroom Production Unit (10%). The effluent had BOD5 of 2350 mg/l, COD of 4600 mg/l, and high levels of total suspended solid (0.43-4.20 mg/l), phosphorus (2078 mg/l), free ammonia (2982 mg/l) and colour index of 50 to 150°H. These values are effluent Standards of Eldoret Town in Kenya. To address these problems, three potential treatment processes were considered: VITOX system using pure oxygen, lagoon evaporation system, and Step-alum coagulation/flocculation process using wood ash leachate for pH adjustment. The latter was chosen because of its efficiency for not only BOD5, COD, phosphorus and free ammonia reduction but also for the complete colour removal when alum was added in two stages as laboratory Jar-tests indicated. A plant was subsequently designed that incorporated a two-step alum coagulation/flocculation process in two upflow tanks with wood-ash leachate for pH adjustment during and after flocculation.

Scanning electron microscopy (SEM) in conjunction with energy dispersive X-ray spectrometry has been used to characterize Athabasca oil sand (AOS) and various coked residues prepared therefrom for mineral phase and size distribution. The composite mineral particles were classified into ten particle size ranges. Increasing coking time caused an increase in the percentage of small particles of quartz and clay The AOS is relatively rich in sulfur and iron; 6.17% and 0.173%, respectively. The micrographs of AOS show that the majority of the sand grains are not in direct contact with each other and that the bitumen forms a thin layer between the grains. For the coked residues, the sand grains were connected to one another by their coke bridges.

Separation of simulated industrial food products, by method of adsorption, has been studied. A thermodynamic approach has been applied to study the liquid adsorption where benzene and cyclohexane have been used to simulate edible oils in a system that employs silica gel as the adsorbent. Different models suggested in the literature have been tested with experimental data in order to characterize properties of the system, such as the tendency to ideality, for both adsorbed and bulk liquid phases. The methods of determining thermodynamic properties such as free energy of adsorption, adsorption capacity and activity coefficients in the adsorbed phase have been studied. It was observed that a model based on the assumption that adsorbed phase, but not liquid phase, is ideal gave a good for that may suffice for engineering design of liquid adsorption systems that may be applied in food processing, such as decolourising crude sugar syrup, recovery of polypeptides and extraction of flavouring. The Journal of Food Technology in Africa Volume 6 Number 2 (April-June 2001), pp. 63-67 KEY WORDS: Separation, food, model, adsorption, simulation and surface excess.

A die-back of Terminalia ivorensis (A. Chev.) is causing widespread damage to this valuable timber species in plantations throughout the tree's natural range in Ghana and Ivory Coast. In this article the characteristic symptoms of T. ivorensis die-back and other relative information are provided. Surveys in both countries show that abnormally chlorotic and diminutive leaves are the first obvious indicators of die-back followed by leaf fall and die-back of branches. Staining of sapwood is commonly found in affected trees and this is usually closely associated with the presence of a fungus of the genus Endothia (Fr.).

A study into the distribution of thermophilic and thermotolerant fungi in a spruce-pine (Picea spp.—Pinus spp.) wood chip pile at Prince George, B.C., was carried out. Five treatments were examined: pine, spruce, spruce containing a core bag of fines, spruce containing a core bag of sterilized spruce chips and spruce containing a core bag of spruce chips inoculated with a Ptychogaster sp. [probably Chrysosporiumpruinosum (Gilman and Abbott) Carmichael]. Samples of wood chips buried at different locations in the chip pile were examined after 3, 6, and 12 month storage periods. From 100 randomly selected chips from each sample, the fungi were isolated on 2% malt, 2% agar, and 0.5% malic acid medium. Data on temperature during storage, pH of wood chips, moisture content, and weight loss at the time of sampling were calculated for the various sampling positions.Thermophilic fungi colonized the inner regions of the wood chip pile where higher wood substance losses occurred, while thermotolerant fungi inhabited the outer regions. Among the thermophilic fungi listed according to frequency of isolation were Byssochlamysemersonii Stolk-Apinis, Allescheriaterrestris Apinis, Sporotrichumthermophile Apinis, Thermoascusaurantiacus Miehe, and Humicolalanuginosa (Griffon and Maublanc) Bunce. The most common thermotolerant fungi were Aspergillusfumigatus Fresenius and C. pruinosum.Fungal distribution was generally related to position in the wood chip pile. Of the associated factors, temperature (17–60 °C) was most strongly related to fungal distribution, whereas treatment, pH of wood chips, and moisture content did not relate to fungal distribution.

Eucalyptus citriodora planted at Sege in Ghana was attacked by a root rot fungus similar to that on roots of Cassia siamea. A description of the fungus is given and the name transferred to the new genus Pseudophaeolus Ryv. Symptoms of the disease, disease cycle and its importance in the management of eucalypt plantations are discussed.

Under laboratory conditions, the effects of culture medium, size of wood sample, method of inoculation, duration and temperature of incubation on weight loss of ponderosa pine (Pinus ponderosa Laws.) sapwood were studied. Test wood samples 0.2 X 1.9 X 4.4 cm were planted on fungal cultures using several different media and incubated at temperatures ranging from 25 to 60 C. Incubation periods ranged from 2 to 12 weeks. Fungi grown on Abrams-cellulose or yeast-cellulose medium generally provided the greatest wood substance loss. Maximum wood substance loss occurred during the first 6 weeks of incubation; incubation longer than this seemed unnecessary. No single incubation temperature provided the maximum activity for all the fungi tested, but 40 C or 50 C were optimum temperatures. The greatest weight losses were obtained if the fungi were grown for one week before the wood samples were planted on the cultures. When wood blocks of three different sizes were used, their loss in weight following fungal degradation appeared to be directly related to their volumes and not to their surface areas. Decreasing block size did not result in an increase in rate of weight loss following fungal attack.