Modelling an abrasive wear experiment by the boundary element method

This Note presents a computational technique for simulating friction-induced wear in a tribology experiment on a plan/plan, ring-on-disc contact configuration. The boundary element method results in modest computing times and facilitates the mesh modifications used for tracking the wear profile evolution. A typical wear simulation result is presented and discussed

Tribological and corrosion wear of graphite ring against Ti6Al4V disk in artificial sea water

Severe degradations result from the friction of two antagonists in sea water environment. It is proposed to evaluate materials resistance to wear with a tribocorrosion experimental set-up which is mechanically and electrochemically instrumented. The method is illustrated with graphite and Ti6Al4V.The deposition of graphite on Ti6Al4V samples is observed and modifies the contact characteristics. Processes of graphite wear due to mechanical effect are characterised. Observations clearly indicate that Ti6Al4V degradations depend on the electrochemical potential imposed and more precisely on the electrochemical conditions in the contact zone

Drivers of dietary behaviours in women living in urban Africa: a systematic mapping review.

OBJECTIVE: To (i) systematically review the literature to determine the factors influencing diet and dietary behaviour in women living in urban Africa; (ii) present these in a visual map; and (iii) utilize this to identify potentially important areas for future research. DESIGN: Systematic mapping review. The review protocol was registered at PROSPERO (http://www.crd.york.ac.uk/PROSPERO/; registration number CRD42015017749). Six databases were systematically searched, followed by reference and citation searching. Eligibility criteria included women aged 18-70 years living in urban Africa, any design/methodology, exploring any driver, using any measure of dietary behaviour. Quality appraisal occurred parallel with data extraction. Twelve predominantly cross-sectional quantitative studies were included; reported in seventeen publications. Determinants were synthesized narratively and compiled into a map adapted from an existing ecological model based on research in high-income countries. SETTING: Urban Africa. SUBJECTS: African women aged 18-70 years. RESULTS: Determinants significantly associated with unhealthy dietary behaviour ranged from the individual to macro level, comprising negative body image perception, perceptions of insufficient food quantity and poorer quality, poorer food knowledge, skipping meals, snacking less, higher alcohol consumption, unhealthy overall lifestyle, older age, higher socio-economic status, having an education, lower household food expenditure, frequent eating outside the home and media influence. Marital status and strong cultural and religious beliefs were also identified as possible determinants. CONCLUSIONS: Few studies have investigated drivers of dietary behaviours in urban African settings. Predominantly individual-level factors were reported. Gaps in the literature identified a need for research into the neglected areas: social, physical and macro-level drivers of food choice

Addressing malnutrition in low- and middle-income countries with double-duty actions

Multiple forms of malnutrition co-exist (the double burden) in low- and middle-income countries, but most interventions and policies target only one form. Identifying shared drivers of the double burden of malnutrition is a first step towards establishing effective interventions that simultaneously address the double burden of malnutrition (known as double-duty actions). We identified shared drivers for the double burden of malnutrition, to assess which double-duty actions are likely to have the greatest reach in preventing all forms of malnutrition, in the context of the sustainable development goals. We reviewed existing conceptual frameworks of the drivers of undernutrition, obesity and environmental sustainability. Shared drivers affecting all forms of malnutrition and environmental sustainability were captured using a socio-ecological approach. The extent to which drivers were addressed by the five double-duty actions proposed by the WHO was assessed. Overall, eighty-three shared drivers for the double burden of malnutrition were identified. A substantial proportion (75·0%) could be addressed by the five WHO double-duty actions. ‘Regulations on marketing’ and ‘promotion of appropriate early and complementary feeding in infants’ addressed the highest proportion of shared drivers (65·1% and 53·0%, respectively). Twenty-four drivers were likely to be sensitive to environmental sustainability, with ‘regulations on marketing’ and ‘school food programmes and policies’ likely to have the greatest environmental reach. A quarter of the shared drivers remained unaddressed by the five WHO double-duty actions. Substantially more drivers could be addressed with minor modifications to the WHO double-duty actions and the addition of de novo actions

What can dietary patterns tell us about the nutrition transition and environmental sustainability of diets in Uganda?

Uganda is undergoing dietary transition, with possible environmental sustainability and health implications, particularly for women. To explore evidence for dietary transitions and identify how environmentally sustainable women’s dietary patterns are, principal component analysis was performed on dietary data collected using a 24 h recall during the Uganda Food Consumption Survey (n = 957). Four dietary patterns explained 23.6% of the variance. The “traditional, high-fat, medium environmental impact” pattern was characterized by high intakes of nuts/seeds, fats, oils and spreads, fish and boiled vegetables. High intakes of bread and buns, rice and pasta, tea and sugar characterized the “transitioning, processed, low environmental impact’ pattern. The ‘plant-based, low environmental impact” pattern was associated with high intakes of legumes, boiled roots/tubers, boiled traditional vegetables, fresh fruit and fried traditional cereals. High intakes of red/organ meats, chicken, and soups characterized the “animal-based high environmental impact” pattern. Urban residence was positively associated with “transitioning, processed, low environmental impact” (β = 1.19; 1.06, 1.32) and “animal-based high environmental impact” (β = 0.45; 0.28, 0.61) patterns; but negatively associated with the “plant-based low environmental impact” pattern (β= −0.49; −0.62, −0.37). A traditional, high-fat dietary pattern with medium environmental impact persists in both contexts. These findings provide some evidence that urban women’s diets are transitioning

Factors influencing dietary behaviours in urban food environments in Africa: a systematic mapping review

Objective: To identify factors influencing dietary behaviours in urban food environments in Africa and identify areas for future research. Design: We systematically reviewed published/grey literature (protocol CRD4201706893). Findings were compiled into a map using a socio-ecological model on four environmental levels: individual, social, physical and macro. Setting: Urban food environments in Africa. Participants: Studies involving adolescents and adults (11–70 years, male/female). Results: Thirty-nine studies were included (six adolescent, fifteen adolescent/adult combined and eighteen adult). Quantitative methods were most common (twenty-eight quantitative, nine qualitative and two mixed methods). Studies were from fifteen African countries. Seventy-seven factors influencing dietary behaviours were identified, with two-thirds at the individual level (45/77). Factors in the social (11/77), physical (12/77) and macro (9/77) environments were investigated less. Individual-level factors that specifically emerged for adolescents included self-esteem, body satisfaction, dieting, spoken language, school attendance, gender, body composition, pubertal development, BMI and fat mass. Studies involving adolescents investigated social environment-level factors more, for example, sharing food with friends. The physical food environment was more commonly explored in adults, for example, convenience/availability of food. Macro-level factors associated with dietary behaviours were food/drink advertising, religion and food prices. Factors associated with dietary behaviour were broadly similar for men and women. Conclusions: The dominance of studies exploring individual-level factors suggests a need for research to explore how social, physical and macro-level environments drive dietary behaviours of adolescents and adults in urban Africa. More studies are needed for adolescents and men, and studies widening the geographical scope to encompass all African countries

Factors influencing dietary practices in a transitioning food environment: a cross-sectional exploration of four dietary typologies among rural and urban Ugandan women using Photovoice

Background Healthy and sustainable dietary practices offer a possible solution to competing tensions between health and environmental sustainability, particularly as global food systems transition. To encourage such dietary practices, it is imperative to understand existing dietary practices and factors influencing these dietary practices. The aim of this study was to identify multi-level factors in lived rural and urban Ugandan food environments that influence existing dietary practices among women of reproductive age (WRA). Methods A mixed methods study was conducted. Multiple correspondence analysis followed by hierarchical cluster analysis were performed on dietary data collected among a sample (n = 73) of Ugandan WRA in Kampala (urban) and Wakiso (rural) districts to elicit dietary clusters. Dietary clusters, which were labelled as dietary typologies based on environmental impact and nutrition transition considerations, were reflective of dietary practices. Following this, a smaller sample of WRA (n = 18) participated in a Photovoice exercise and in-depth interviews to identify factors in their social, physical, socio-cultural and macro-level environments influencing their enactment of the identified dietary typologies, and therefore dietary practices. Results Four dietary typologies emerged: ‘urban, low-impact, early-stage transitioners’, ‘urban, medium-impact, mid-stage transitioners’, ‘rural, low-impact, early-stage transitioners’ and ‘rural, low-impact, traditionalists’. Although experienced somewhat differently, the physical environment (access, availability and cost), social networks (parents, other family members and friends) and socio-cultural environment (dietary norms) were cross-cutting influences among both urban and rural dietary typologies. Seasonality (macro-environment) directly influenced consumption of healthier and lower environmental impact, plant-based foods among the two rural dietary typology participants, while seasonality and transportation intersected to influence consumption of healthier and lower environmental impact, plant-based foods among participants in the two urban dietary typologies. Conclusion Participants displayed a range of dietary typologies, and therefore dietary practices. Family provides an avenue through which interventions aimed at encouraging healthier and lower environmental impact dietary practices can be targeted. Home gardens, urban farming and improved transportation could address challenges in availability and access to healthier, lower environmental impact plant-based foods among urban WRA

Unhealthy food and beverage consumption during childhood and risk of cardiometabolic disease: a systematic review of prospective cohort studies

Background Global consumption of unhealthy foods, including ultra-processed foods (UPFs) and sugar-sweetened beverages (SSBs), has increased substantially among pediatric populations. Suboptimal diet during early life can track into adulthood, alongside risk factors for cardiometabolic disease. Objective To inform the development of updated WHO guiding principles for complementary feeding of infants and young children, this systematic review sought to examine the association between unhealthy food consumption during childhood and cardiometabolic risk biomarkers. Methods PubMed (Medline), EMBASE, and Cochrane CENTRAL were systematically searched, with no language restriction, up to 10 March 2022. Inclusion criteria were randomized controlled trials (RCTs), non-RCTs, and longitudinal cohort studies; children aged ≤10.9 y at exposure; studies reporting greater consumption of unhealthy foods and beverages (defined using nutrient- and food-based approaches) than no or low consumption; studies assessing critical nonanthropometric cardiometabolic disease risk outcomes (blood lipid profile, glycemic control, or blood pressure). Results Of 30,021 identified citations, 11 articles from 8 longitudinal cohort studies were included. Six studies focused on exposure to unhealthy foods or UPF, and 4 focused on SSB only. Methodological heterogeneity was too high across studies to meta-analyze effect estimates. A narrative synthesis of quantitative data revealed that exposure to unhealthy foods and beverages, specifically NOVA-defined UPF, in children of preschool age may be associated with a worse blood lipid and blood pressure profile in later childhood (Grading of Recommendations Assessment, Development, and Evaluation [GRADE]: low and very low certainty, respectively). No associations were evident between SSB consumption and blood lipids, glycemic control, or blood pressure (GRADE: all low certainty). Conclusions No definitive conclusion can be made because of quality of the data. More high-quality studies that purposefully assess the effects of unhealthy food and beverage exposure during childhood on cardiometabolic risk outcomes are needed. This protocol was registered at https://www.crd.york.ac.uk/PROSPERO/ as CRD42020218109

Unhealthy food and beverage consumption in children and risk of overweight and obesity: a systematic review and meta-analysis

This WHO-commissioned review contributed to the update of complementary feeding recommendations, synthesizing evidence on effects of unhealthy food and beverage consumption in children on overweight and obesity. We searched PubMed (Medline), Cochrane CENTRAL and Embase for articles, irrespective of language or geography. Inclusion criteria were: 1) randomized controlled trials (RCTs); non-RCTs; cohort studies and pre/post studies with control; 2) participants ≤ 10.9 y at exposure; 3) studies reporting greater consumption of unhealthy foods/beverages vs. no or low consumption; 4) studies assessing anthropometric and/or body composition; and 5) publication date ≥ 1971. Unhealthy foods and beverages were defined using nutrient- and food-based approaches. Risk of bias was assessed using the ROBINS-I and RoB2 tools for non-randomized and randomized studies, respectively. Narrative synthesis was complemented by meta-analyses where appropriate. Certainty of evidence was assessed using GRADE. Of 26,542 identified citations, 60 studies from 71 articles were included. Most studies were observational (59/60), and no included studies were from low-income countries. The evidence base was low quality, as assessed by ROBINS-I and RoB2 tools. Evidence synthesis was limited by the different interventions and comparators across studies. Evidence indicated that consumption of sugar-sweetened beverages (SSB) and unhealthy foods in childhood may increase body mass index (BMI)/BMI z-score, % body fat or odds of overweight/obesity (low certainty of evidence). Artificially-sweetened beverages and 100% fruit juice consumption may make little/no difference to BMI, % body fat or overweight/obesity outcomes (low certainty of evidence). Meta-analyses of a subset of studies indicated a positive association between SSB intake and % body fat, but no association with change in BMI and BMI z-score. High-quality epidemiological studies that are designed to assess the effects of unhealthy food consumption during childhood on risk of overweight/obesity are needed to contribute to a more robust evidence base upon which to design policy recommendations. This protocol was registered at https://www.crd.york.ac.uk/PROSPERO as CRD42020218109