Spatial variability in penetration resistance of a hardsetting tropical alfisol

Geostatistical techniques were used to analyse the spatial variation of penetration resistance on an experimental plot intended for root studies. Penetration resistance was measured at two soil water conditions. Penetration resistance exhibited spatial structure but the models describing the semivariograms were different for the two soil water conditions. An isotropic linear model provided the best fit for penetration resistance in the dry soil while an isotropic spherical model was used for penetration in the wet soil. A complementary study of the spatial structure of water content also showed a similar trend. Cross-semivariograms were constructed to determine the spatial relationship between penetration resistance and water content. Penetration resistance in the dry soil was negatively correlated with water content. The nugget variances as the percentage of the sill in the wet soil data set suggest that the topsoil was slightly more variable than the subsoil. The spatial scale of variation in penetration resistance of the wet soil was 33 m at 7.5 cm depth and 20–27 m at 15–30 cm depth. Punctual kriging was used to estimate the penetration resistance and water content values. The estimated values are presented as contour maps. The pattern of variation and the underlying possible processes for the variation are discussed. The results suggest that the likely influence of spatial variation of soil properties on crop growth may have to be considered in modelling in order to simulate the real field situation

Smartphone colorimetry using ambient subtraction: Application to neonatal jaundice screening in Ghana

A smartphone app to screen for neonatal jaundice has a large potential impact in reducing neonatal death and disability. Our app, neoSCB, uses a colour measurement of the sclera to make a screening decision. Although there are numerous benefits of a smartphone-based approach, smartphone colour measurement that is accurate and repeatable is a challenge. Using data from a clinical setting in Ghana, we compare sclera colour measurement using an ambient subtraction method to sclera colour measurement using a standard colour card method, and find they are comparable provided the subtracted signal-to-noise ratio (SSNR) is sufficient. Calculating a screening decision metric via the colour card method gave 100% sensitivity and 69% specificity (n=87), while applying the ambient subtraction method gave 100% sensitivity and 78% specificity (SSNR>3.5; n=50)

Feasibility of smartphone colorimetry of the face as an anaemia screening tool for infants and young children in Ghana

Background Anaemia affects approximately a quarter of the global population. When anaemia occurs during childhood, it can increase susceptibility to infectious diseases and impair cognitive development. This research uses smartphone-based colorimetry to develop a non-invasive technique for screening for anaemia in a previously understudied population of infants and young children in Ghana. Methods We propose a colorimetric algorithm for screening for anaemia which uses a novel combination of three regions of interest: the lower eyelid (palpebral conjunctiva), the sclera, and the mucosal membrane adjacent to the lower lip. These regions are chosen to have minimal skin pigmentation occluding the blood chromaticity. As part of the algorithm development, different methods were compared for (1) accounting for varying ambient lighting, and (2) choosing a chromaticity metric for each region of interest. In comparison to some prior work, no specialist hardware (such as a colour reference card) is required for image acquisition. Results Sixty-two patients under 4 years of age were recruited as a convenience clinical sample in Korle Bu Teaching Hospital, Ghana. Forty-three of these had quality images for all regions of interest. Using a naïve Bayes classifier, this method was capable of screening for anaemia (<11.0g/dL haemoglobin concentration) vs healthy blood haemoglobin concentration (≥11.0g/dL) with a sensitivity of 92.9% (95% CI 66.1% to 99.8%), a specificity of 89.7% (72.7% to 97.8%) when acting on unseen data, using only an affordable smartphone and no additional hardware. Conclusion These results add to the body of evidence suggesting that smartphone colorimetry is likely to be a useful tool for making anaemia screening more widely available. However, there remains no consensus on the optimal method for image preprocessing or feature extraction, especially across diverse patient populations

Smoke-Free Policy in Vermont Public Housing Authorities

Introduction. Millions of adults and children living in public housing face exposure to second hand smoke from adjacent apartments. These tenants are less able to escape smoke exposure by moving, and Housing Authorities are beginning to implement smoke-free policies. We assessed the status of smoke-free policy in Vermont public housing, and explored the experience of tenants and managers in Burlington who recently implemented such a policy.https://scholarworks.uvm.edu/comphp_gallery/1080/thumbnail.jp

Measuring soil processes in agricultural research

Soil and crop management strategies (e.g., tillage, bunding, cropping intensity, and crop sequencing) are location- and season-specific in the way they affect soil processes and resource utilization by crops. Research findings on these effects therefore need to be modeled if they are to be extrapolated to other locations wi th similar soils and climatic conditions. This manual presents practical methods for assessing management effects on such soil processes as water infiltration and erosion by water, and on water, air, and nutrient use by crops. It covers the basic elements of soil physical characterization, and deals principally with the role of soil structure on water infiltration and percolation, heat flow, aeration, and the mobility of roots and soil microorganisms. The authors discuss the agronomic and engineering practices that affect soil processes; and the effects of such strategies as contour cultivation, organic and inorganic amendments, watershed management, and soil surface manipulations are emphasized

Perception and risk factors for cervical cancer among women in northern Ghana

Objective: This study assessed the perception of risk of cervical cancer and existence of risk factors for cervical cancer based on five known risk factors among women attending the Tamale Teaching Hospital in Tamale, Ghana.Methods: A consecutive sample of 300 women was interviewed using a semi structured questionnaire to inquire about risk factors and perception of risk of cervical cancer. Specific risk factors that were explored included early coitarche, multiple sexual partners, polygamous relationships, history of smoking, and having a current partner who had multiple sexual partners.Results: Sixty-one per cent of women reported that they had no personal risk for cervical cancer. 27% of respondents were in polygamous relationships, and of those, more than half didn’t think they were at an increased risk of cervical cancer. 2 women had a total of ≥ 5 sexual partners in their lifetime and neither believed they were at any risk for cervical cancer. 23% said their current partner had had at least 2 sexual partners in his lifetime, and of those, (61%) thought they were at no risk for cervical cancer. 46% of respondents reported not having any of the risk factors listed in the study. 23% of respondents reported having one risk factor while 21% had two risk factors and 11% had three or more risk factors.Conclusion: Women’s perception of personal risk for cervical cancer is lower than their actual risk based on the five behavioural risk factors assessed and a lack of knowledge of the personal factors for the diseaseFunding: This project was supported by NIH Research Training Grant #R25 TW009345 funded by the Fogarty International Centre, in partnership with several NIH Institutes (NIMH, NIGMS, NHLBI, OAR and OWH)Keywords: Cervical Cancer, Risk, Perceptions, Northern Ghan

Gaseous emissions during concurrent combustion of biomass and non-recyclable municipal solid waste

Background: Biomass and municipal solid waste offer sustainable sources of energy; for example to meet heat and electricity demand in the form of combined cooling, heat and power. Combustion of biomass has a lesser impact than solid fossil fuels (e. g. coal) upon gas pollutant emissions, whilst energy recovery from municipal solid waste is a beneficial component of an integrated, sustainable waste management programme. Concurrent combustion of these fuels using a fluidised bed combustor may be a successful method of overcoming some of the disadvantages of biomass (high fuel supply and distribution costs, combustion characteristics) and characteristics of municipal solid waste (heterogeneous content, conflict with materials recycling). It should be considered that combustion of municipal solid waste may be a financially attractive disposal route if a 'gate fee' value exists for accepting waste for combustion, which will reduce the net cost of utilising relatively more expensive biomass fuels. Results: Emissions of nitrogen monoxide and sulphur dioxide for combustion of biomass are suppressed after substitution of biomass for municipal solid waste materials as the input fuel mixture. Interactions between these and other pollutants such as hydrogen chloride, nitrous oxide and carbon monoxide indicate complex, competing reactions occur between intermediates of these compounds to determine final resultant emissions. Conclusions: Fluidised bed concurrent combustion is an appropriate technique to exploit biomass and municipal solid waste resources, without the use of fossil fuels. The addition of municipal solid waste to biomass combustion has the effect of reducing emissions of some gaseous pollutants