Food insecurity in households in informal settlements in urban South Africa

Food insecurity in the urban poor is a major public health challenge. The Health, Environment and Development study assessed trends in food insecurity and food consumption over a period of 7 years in an informal settlement in Johannesburg, South Africa (SA). Annual cross-sectional surveys were conducted in the informal settlement (Hospital Hill). The degree of household food insecurity decreased significantly from 2006 (85%) to 2012 (70%). There was a spike in 2009 (91%), possibly owing to global food price increases. Childhood food insecurity followed the same trend as household food insecurity. During the first 3 study years, consumption of protein, vegetables and fruit decreased by 10 - 20%, but had returned to previous levels by 2012. In this study, although declining, food insecurity remains unacceptably high. Hunger relief and poverty alleviation need to be more aggressively implemented in order to improve the quality of life in poor urban communities in SA

What is an ROC curve?

The paper by Body et al is concerned with the evaluation of decision aids, which can be used to identify potential acute coronary syndromes (ACS) in the ED. The authors previously developed the Manchester Acute Coronary Syndromes model (MACS) decision aid, which uses several clinical variables and two biomarkers to ‘rule in’ and ‘rule out’ ACS. However, one of the two biomarkers (heart-type fatty acid bindingprotein, H-FABP) is not widely used so a revised decision aid has been developed (Troponin-only Manchester Acute Coronary Syndromes, T-MACS), which include a single biomarker hs-cTnT. In this issue, the authors show how they derive a revised decision aid and describe its performance in a number of independent diagnostic cohort studies. Decision aids (as well as other types of ‘diagnostic tests’) are often evaluated in terms of diagnostic testing parameters such as the area under the receiver operating characteristic (ROC) curve, sensitivity and specificity. In this article, we explain how the ROC analysis is conducted and why it is an essential step towards developing a test with the desirable levels of sensitivity and specificity

A systematic review of the role of non-magnified endoscopy for the assessment of H. pylori infection.

Background There is growing interest in the endoscopic recognition of H. pylori infection, and application to routine practice. We present a systematic review of the current literature regarding diagnosis of H. pylori during standard (non-magnified) endoscopy, including adjuncts such as image enhancement and computer-aided diagnosis. Method The Medline and Cochrane databases were searched for studies investigating the performance of non-magnified optical diagnosis for H. pylori, or those which characterised mucosal features associated with H. pylori infection. Studies were preferred with a validated reference test as the comparator, although were included if at least one validated reference test was used. Results 20 suitable studies were identified and included for analysis. In total, 4,703 patients underwent investigation including white light endoscopy, narrow band imaging, i-scan, blue-laser imaging, and computer-aided diagnostic techniques. The endoscopic features of H. pylori infection observed using each modality are discussed and diagnostic accuracies reported. The Regular Arrangement of Collecting Venules (RAC) is an important predictor of the H. pylori naïve stomach. ‘Mosaic’ and ‘Mottled’ patterns have a positive association with H. pylori infection. The ‘Cracked’ pattern may be a predictor of an H. pylori negative stomach following eradication. Conclusions This review summarises the current progress made in endoscopic diagnosis of H. pylori infection. At present there is no single diagnostic approach that provides validated diagnostic accuracy. Further prospective studies are required, as is the development of a validated classification system. Early studies in Computer-Aided Diagnosis suggest potential for a high level of accuracy but real-time results are awaited

The endoscopy evolution: 'the superscope era'

Developments to the design of the flexible endoscope are transforming the field of gastroenterology. There is a drive to improve colonic adenoma detection rates leading to advancements in the design of the colonoscope. Novel endoscopes now allow increased visualisation of colonic mucosa, including behind colonic folds, and aim to reduce pain associated with the procedure. In addition, a shift in surgical paradigm towards minimally invasive endoluminal surgery has meant innovations in flexible platforms are being sought. There are a number of limitations of the basic endoscope. These include a lack of stability and triangulation of instruments. Modifications to the flexible endoscope design form the basis of a number of newly developed and research platforms, some of which are discussed in this review

Flexible multimode endoscope for tissue reflectance and autofluorescence hyperspectral imaging

A dual reflectance and autofluorescence spectral imaging probe compatible with the biopsy channels of standard flexible endoscopes is demonstrated. Spatially-resolved haemoglobin and autofluorescent signals from porcine bowel were obtained in vivo

Individual burner air/fuel ratio control optical adaptive feedback control system

On cover : Combustion Research Facility.Conventional combustion control systems for multiburner installations which rely on monitoring the average C02 and/or 02 content of the gases have a number of inherent limitations on their ability to maintain efficient plant operation. Air infiltration'into the flue or sampling lines has the same effect as an instrumental error in causing the control system to adjust the stoichiometry to an incorrect level. Even' when the overall stoichiometry of the furnace is correctly and accurately controlled it is still extremely difficult to ensure that no individual burners are operating inefficiently due to local maldistributions of air or fuel, or to poor nozzle spray characteristics. The potential for fuel savings and for'improved limitation of pollutant emissions has provided strong incentive for the development of individual burner fuel/air ratio control systems which would eliminate the shortcomings associated with the global control method. The present report first reviews past attempts to identify some unique property of an individual flame which can be reliably interpreted as an indicator of the flame behavior over a wide range of operating conditions.. Information potentially usable in this manner could be contained in the acoustic characteristics of the flame, in the local distribution of key chemical species, or in the electromagnetic radiation or absorption behavior of regions of the flame. For many reasons the previous studies have tended to concentrate on the optical portion of the electromagnetic spectrum, with particular emphasis on emission from flames over much of the ultraviolet (u.v.), visible and infrared (i.r.) wavelength regions. A brief review is given of the pioneering work of Penzias and his associates, and of the later work carried out at Sheffield University by Smith which led to the development of the LandTM control system. All of these studies dealt with the infrared emission from flames, wilth particular emphasis on the CO2 barnd at 4.3 pm, and on the H0/CO2 binds near 2.8 m. The report then addresses the experimental work carried out at M.I.T under the sponsorship of five utility companies supporting the M.I.T. Energy Laboratory Electric Power Program. This focused initially on attempts to use a Land control system in the Combustion Research Facility (CRF), with limited success in terms of achieving stability and adequacy of control when operating conditions were varied over a moderate range. The experiments in the CRF also yielded very useful data on the intensities and sources of u.v. emission from No. 6 fuel oil flames over a wide range of fuel equivalence ratio. One other set of experiments carried out in the CRF made use of equipment and personnel supplied by the Foxboro Company, and results of this work are discussed. Also included in the report is a summary of measurements carried out on a small methane-fueled burner which add appreciably to the available information on the dependence of the infrared emission on viewing location relative to the flame front and on fuel equivalence ratio. The overall results obtained under this program do not leave the prospect of individual fuel/air ratio controllers within immediate grasp, but they substantially advance the state of knowledge required for attainment of such control. They give a strong indication that satisfactory control could be obtained over a wide range of furnace operating conditions if both i.r. and u.v. signals were monitored and used in the control system

Malignant melanoma of the gastrointestinal tract: symptoms, diagnosis, and current treatment options.

Malignant melanoma (MM) has become the fifth most frequent cancer in the UK. It is the most common carcinoma to metastasize to the gastrointestinal (GI) tract. MM particularly has an affinity to spread to the small bowel, which is followed by the involvement of the stomach and large intestine. Excellent endoscopic options including video capsule endoscopy and enteroscopy are available for a precise diagnosis of GI involvement by a metastatic MM. The complete surgical resection of GI metastatic MM in carefully selected patients not only provides symptom control, but has also been associated with an increase in overall survival. The approval of BRAF-targeted therapies and immune checkpoint inhibitors has transformed therapeutic approaches for patients with metastatic MM over the past decade. Currently, the overall survival of patients with advanced metastatic MM who have been treated with a combination of immunotherapeutic agents reaches 52% at five years. The role of surgery for patients with the metastatic involvement of the GI tract with MM is evolving in the era of effective systemic treatments

Assessment of disk MHD generators for a base load powerplant

Results from a study of the disk MHD generator are presented. Both open and closed cycle disk systems were investigated. Costing of the open cycle disk components (nozzle, channel, diffuser, radiant boiler, magnet and power management) was done. However, no detailed costing was done for the closed cycle systems. Preliminary plant design for the open cycle systems was also completed. Based on the system study results, an economic assessment of the open cycle systems is presented. Costs of the open cycle disk conponents are less than comparable linear generator components. Also, costs of electricity for the open cycle disk systems are competitive with comparable linear systems. Advantages of the disk design simplicity are considered. Improvements in the channel availability or a reduction in the channel lifetime requirement are possible as a result of the disk design