Seedbed treatment with direct heat from burning stubble and its effect on seedbed fungi, damping-off, and growth of tomato seedlings

A 1-m2 seedbed with a history of damping-off was exposed to heat from burning stubble and assayed for soil fungi, damping-off, and growth of tomato seedlings. Seedbed drenched with a formalin-water mixture and an untreated seedbed were also studied. Heat was produced by burning a heap of stubble on the bed two times in two consecutive days. Temperatures of the heated bed were measured during heating at about 0-5 and 5-15 cm depths with a thermocouple fitted to a thermometer. Seedbed soils were assayed for fungi by the soil dilution plate technique and the beds bioassayed two times in situ at 4-mn interval with the tomato cultivar, Power. Soil pH, nitrogen, phosphorous and potassium concentrations were also determined. Soil temperatures ranging from an average of 55 oC (bottom 5-15 cm) to 70 oC (top 5 cm) were recorded during burning. Heating eradicated pythiaceous fungi and most fungi from the top 15 cm of the seedbed. Untreated seedbed had significantly higher populations of fungi. The effect of heat was comparable to that of formalin. Post-emergence damping-off was 0, 0.65 and 55.88 per cent, respectively, on the heated, formalin-treated and untreated beds. Tomato seedling growth (seedling height, fresh and dry weights) was significantly greater on the heated bed than on the unheated bed. Higher levels of soil pH, potassium and phosphorous were associated with the heated seedbed. However, soil nitrogen was unaffected. Based on these results, burning of stubble on seedbeds can be recommended as a non-chemical integrated pest management approach against weeds, damping-off of seedlings, and for enhancing seedbed fertility.Un semis de 1m2 ayant une histoire de humectage était exposé à la chaleur de chaume brûlant et mis à l'essai pour le fongus du sol, le humectage et la croissance à venir de jeunes tomates. Pour le but de comparaison un semis trempé de formol: eau (7:1) mélangé et un semis non-traité étaient également étudiés. Chauffage était accompli par le vrûlage d'un tas de chaume sur le semis deux fois pendant deux jours consécutifs. Les températures de semis chauffé étaient prises pendant le chauffage à approximativement 0-5 cm et 5-15 cm de profondeurs avec une thermocouple ajusté au thermomètre. Les sols du semis étaient mis à l'essai pour le fongus pat la technique de plaque de dikution du sol et les semis étaient mis au bio-essai deux fois in situ à l'intervale de 4-mn avec la variété du tomate appellée Power. Les niveaux de pH du sol, l'azote, la phosphore et le potassium étaient également déterminés. Les températures de sol variant entre un moyen de 55 oC (en bas 5-15 cm) et 70 oC (enhaut 5 cm) étaient réalisées pendant le brûlage Chauffage éradiquait le fongus pythiaceoux et la pludart fongus de 15 cm du haut du semis. Le semis non-traité avait les populations de fongus considérablement plus élevées. L'effet de la chaleur était comparable à celui de formol. Le humectage de post émergence était 0, 0.65 et 55.88 % respectivement sur les semis chauffés, traités de formol et non-traités. La croissance de jeune tomate (taille de jeune tomate, poids de plante fraîche, poids de plante sèche) était considérablement meilleure sur le semis traité de chaleur que sur le semis non-traité. Les niveaux plus élevés de pH du sol de potassium et de phosphore étaient associés avec le semis chauffé. L'azote du sol n'était, cependant, pas influencé. D'après ces résultats, le brûlage de chaume sur les semis pourrait être recommandé comme un approche non-chimique intégré de désinsectisation pour lutter contre les mauvaises herbes et le humectage de jeunes tomates et pour eméliorer la fertilité du semis. Ghana Journal of Agricultural Science Vol. 39 (1) 2006: pp. 51-6

An adaptive household sampling method for rural African communities

Investigators working in rural communities and small towns in Africa face many obstacles to obtaining a random and representative sample of households for their research. The civic infrastructure used as the building blocks of survey sampling in developed countries are mostly absent in rural Africa. The purpose of the study described in this paper was to pilot an innovative and cost-effective approach to household sampling designed to generate probability samples representative of the socio-economic diversity of the small town of Berekuso, in the Eastern Region of Ghana, without relying on existing census data, household registers, or a regular layout of roads and dwellings. Utilizing Google Earth images and a Graphical Information System (GIS) map of Berekuso, sampling units were defined as 15-degree wedge-shaped sectors radiating from the center of the original township. All households within randomly selected sectors were surveyed, and based on a household classification scheme, each household type was identified. Additional sectors were randomly selected and surveyed in sequence until no new household types were identified – a notion recognized by laboratory scientists as an ‘end point’. The adaptive sampling strategy was cost and time effective: freely available versions of Google Earth and QGIS software were employed along with inexpensive handheld Global Positioning System (GPS) devices; a total of 57 households were surveyed by teams of two enumerators over three consecutive Sundays. The survey method yielded a probability sample that is representative of the socioeconomic diversity of Berekuso, and produced generalizable results for median household size, median age of residents, sources of potable water and toilet types, among others. For example, based on the results of the survey, a 95% confidence interval estimate of the proportion of residents of Berekuso under the age of 20 years is between 0.49 and 0.58. These figures are consistent with results of Ghana’s 2010 census which pegged the proportion of the population of the Eastern Region under the age of the 20 years at 0.49. The authors believe that the methodology described in this paper may be applicable to household research in many rural African villages and small towns where little civic infrastructure exists to create more traditional sampling frames.Key words: Google Earth, area sampling, household survey, impact evaluation, wealth rankin

Defluorination of drinking water using surfactant modified zeolites

The prevalence of high concentrations of fluoride (i.e. > 1.5 mg/l) in groundwater in the Northernpart of Ghana especially around the Bongo communities has been an issue of concern.Owingto the arid nature of these localities, the inhabitants (who are mainly peasant farmers), relymore on groundwater sources for their drinking water. With the strenuous nature of their joband the warm weather conditions, the farmers generally consume more water, thus becomingmore vulnerable to dental and skeletal fluorosis. This study focused on the removal of fluoridefrom groundwater by employing surfactant modified zeolites (SMZ) synthesized using locallyavailable kaolin material as precursor. The zeolite synthesis involved calcination of kaolin, alkaline fusion and hydrothermal treatment. The final product was modified with 5g/L Hexadecyltrimethylammonium bromide (HDTMABr). The zeolite was characterised by Xray Diffraction(XRD), Energy Dispersive Xray (EDX) and Scanning Electron Microscopy (SEM) and the modified form employed in batch fluoride removal studies. The fluoride adsorption kinetics was studiedusing model water with varying initial fluoride concentration. From the EDX analysis, the synthesized zeolite NaLSX was found to comprise predominantly Oxygen (60%), Silicon (15%), and Aluminium (13%). The SEM showed the zeolite NaLSX crystals to be octahedrally shaped. The unmodified zeolite NaLSX was incapable of adsorbing fluoride ions but the surfactant modified zeolite adsorbed fluoride. The fluoride adsorption capacity of the modified zeolite was pH dependent and peaked at pH 6.0 – 7.0. Keywords: characterization, defluoridation, groundwater, surfactant, zeolite

Evaluating Access to Potable Water and Basic Sanitation in Ghana's Largest Urban Slum Community: Old Fadama, Accra

Access to potable water and basic sanitation in urban poor communities remains a critical issue in the developing world. This paper examines access to potable water and basic sanitation in Ghana's largest urban slum and the level of commitment by stakeholders to improve the current conditions. It drew on an extensive field survey, interviews, focus group discussions and drinking water quality analyses. The study revealed that the community depend entirely on vended water for their daily water supply needs. Apart from being sold at exorbitant prices, the sources of drinking water is also contaminated with attendant health risks. Household toilets are non-existent in the community and thus residents rely exclusively on public latrines; KVIP and pan latrines which are also inadequate. This partly accounts for the practice of open defecation in the community with possible health effects such as diarrhea and cholera. Indiscriminate dumping of refuse, choked drains and pools of stagnant water are ubiquitous thereby posing health threats. There is a low level of commitment to improving access to water and sanitation in the community by major stakeholders in spite of the glaring health effects. The outcomes of this study will be useful to relevant stakeholders and authorities in developing suitable strategies for improving access to water and sanitation for urban poor communities. Keywords: Accra, health, Old Fadama, sanitation, slum, wate

Mild Deprotection of the \u3cem\u3eN-Tert\u3c/em\u3e-Butyloxycarbonyl (\u3cem\u3eN\u3c/em\u3e-Boc) Group Using Oxalyl Chloride

We report a mild method for the selective deprotection of the N-Boc group from a structurally diverse set of compounds, encompassing aliphatic, aromatic, and heterocyclic substrates by using oxalyl chloride in methanol. The reactions take place under room temperature conditions for 1–4 h with yields up to 90%. This mild procedure was applied to a hybrid, medicinally active compound FC1, which is a novel dual inhibitor of IDO1 and DNA Pol gamma. A broader mechanism involving the electrophilic character of oxalyl chloride is postulated for this deprotection strategy

Effect of crystallization time on the hydrothermal synthesis of zeolites from kaolin and bauxite

Kaolin and bauxite were used as alumina and silica sources to synthesize zeolites hydrothermally. The source mate-rials as well as the synthesized zeolites were characterized by X-ray diffraction (XRD) scanning electron microscopy (SEM), en-ergy dispersive x-ray analysis (EDX) and Fourier transformed infrared spectroscopy (FTIR). XRD spectra of the bauxite showed Gibbsite phase whereas that of kaolin gave 32.4 % quartz and 67.6 %. The main phases of zeolites obtained after hydrothermal crystallizations were zeolite types LTA, analcime and zeolite X. Longer crystallization time resulted in phase change of the zeo-lites into sodalite. Hence, natural raw materials such as bauxite and kaolin have the attractive features of providing the staring reagents for the synthesis of ultrapure synthetic zeolites

Synthesis, Characterization, and Antiproliferative Activity of Novel Chiral [QuinoxP*AuCl2]\u3csup\u3e+\u3c/sup\u3e Complexes

Herein is reported the synthesis of two Au(III) complexes bearing the (R,R)-(–)-2,3-Bis(tert-butylmethylphosphino)quinoxaline (R,R-QuinoxP*) or (S,S)-(+)-2,3-Bis(tert-butylmethylphosphino)quinoxaline (S,S-QuinoxP*) ligands. By reacting two stoichiometric equivalents of HAuCl4.3H2O to one equivalent of the corresponding QuinoxP* ligand, (R,R)-(–)-2,3-Bis(tert-butylmethylphosphino)quinoxalinedichlorogold(III) tetrachloroaurates(III) (1) and (S,S)-(+)-2,3-Bis(tert-butylmethylphosphino)quinoxalinedichlorogold(III) tetrachloroaurates(III) (2) were formed, respectively, in moderate yields. The structure of (S,S)-(+)-2,3-Bis(tert-butylmethylphosphino)quinoxalinedichlorogold(III) tetrachloroaurates(III) (2) was further confirmed by X-ray crystallography. The antiproliferative activities of the two compounds were evaluated in a panel of cell lines and exhibited promising results comparable to auranofin and cisplatin with IC50 values between 1.08 and 4.83 µM. It is noteworthy that in comparison to other platinum and ruthenium enantiomeric complexes, the two enantiomers (1 and 2) do not exhibit different cytotoxic effects. The compounds exhibited stability in biologically relevant media over 48 h as well as inert reactivity to excess glutathione at 37 °C. These results demonstrate that the Au(III) atom, stabilized by the QuinoxP* ligand, can provide exciting compounds for novel anticancer drugs. These complexes provide a new scaffold to further develop a robust and diverse library of chiral phosphorus Au(III) complexes

Effects of Different Solid Loading Rates of Faecal Sludge on the Dewatering Performance of Unplanted Filter Bed.

The aim of this study was to investigate which Solid Loading Rate (SLR) of faecal sludge will best improve the dewatering performance of selected sand with particle sizes range of (? 0.1 ? 0.5) mm raised on bench scale filter beds. Public toilet sludge  and septage collected from suction trucks discharging at Dompoase stabilisation  ponds in Kumasi , Ghana, mixed in the ratio of 1:1, 1:2 and 1:3 by volume representing SLR1, SLR2 and SLR3 respectively, were used for the dewatering. Percolate volume was measured every 24 hour. The faecal sludge of SLR1, SLR2 and SLR3 dewatered at average dewatering times of 7, 5 and 4 days respectively. Removal efficiencies of the different solid loading rates though very high for TS, SS, TVS, COD, DCOD, NH3-N, did not show any significant difference. Organic matter build up in the top 10cm of the filter bed was least in SLR3. Again SLR3 showed the highest potential for annual generation of biosolids at 438, 421 and 379 (kg/m2 year) for SL3, SLR2 and SLR1 respectively. Therefore SLR3 of faecal sludge is recommended for dewatering on the selected filter bed. Key words: Faecal sludge, solid loading rate, dewatering time, filter bed, percolate

An adaptive household sampling method for rural African communities

Part of the Berekuso Impact StudyInvestigators working in rural communities and small towns in Africa face many obstacles to obtaining a random and representative sample of households for their research. The civic infrastructure used as the building blocks of survey sampling in developed countries are mostly absent in rural Africa. The purpose of the study described in this paper was to pilot an innovative and cost-effective approach to household sampling designed to generate probability samples representative of the socio-economic diversity of the small town of Berekuso, in the Eastern Region of Ghana, without relying on existing census data, household registers, or a regular layout of roads and dwellings. Utilizing Google Earth images and a Graphical Information System (GIS) map of Berekuso, sampling units were defined as 15-degree wedge-shaped sectors radiating from the center of the original township. All households within randomly selected sectors were surveyed, and based on a household classification scheme, each household type was identified. Additional sectors were randomly selected and surveyed in sequence until no new household types were identified – a notion recognized by laboratory scientists as an‘end point’. The adaptive sampling strategy was cost and time effective: freely available versions of Google Earth and QGIS software were employed along with inexpensive handheld Global Positioning System (GPS) devices; a total of 57 households were surveyed by teams of two enumerators over three consecutive Sundays. The survey method yielded a probability sample that is representative of the socioeconomic diversity of Berekuso, and produced generalizable results for median household size, median age of residents, sources of potable water and toilet types, among others. For example, based on the results of the survey, a 95% confidence interval estimate of the proportion of residents of Berekuso under the age of 20 years is between 0.49 and 0.58. These figures are consistent with results of Ghana’s 2010 census which pegged the proportion of the population of the Eastern Region under the age of the 20 years at 0.49. The authors believe that the methodology described in this paper may be applicable to household research in many rural African villages and small towns where little civic infrastructure exists to create more traditional sampling frames.Ashesi University Colleg

Non-communicable disease comorbidities in KwaZulu-Natal Province, South Africa

Background. The prevalence of chronic non-communicable disease (NCD) comorbidity in low- to middle-income countries is increasing, yet evidence on the pattern, prevalence, awareness and treatment of NCD comorbidity is inadequate.Objectives. To investigate the prevalence, awareness, treatment and control of comorbid hypertension and diabetes, and the underlying risk factors in Mpumza, KwaZulu-Natal Province, South Africa (SA).Methods. Data were gathered by the SA Human Sciences Research Council from 587 participants in KwaZulu-Natal in 2015. Percentages were used to describe all the variables. Cross-tabulations and χ2 tests were used to describe variations in the prevalences of hypertension, diabetes and comorbidities according to sociodemographic and socioeconomic variables and lifestyle risk factors.Results. Approximately a third of the participants had hypertension (32%) and 9% had diabetes. The prevalence of comorbid hypertension and diabetes was 6%, and this was significantly higher among women, the aged, the obese, and the formerly married compared with their counterparts. Comorbidity awareness was high (86%). Although most of the participants with comorbidities were being treated with lifestyle changes, insulin and antihypertensive medication (74%), control of comorbidities was low (13%).Conclusions. The study reported a higher burden of comorbid hypertension and diabetes among vulnerable populations in Mpumza, SA, particularly women, the obese, and those with a low level of education. In addition, control of comorbidities was low. Developing appropriate interventions to improve control of comorbidities can reduce the risk of macrovascular and microvascular diseases in this population