Clinicopathologic characteristics of early-onset breast cancer: a comparative analysis of cases from across Ghana.

BACKGROUND: Breast cancer is the commonest cancer diagnosed globally and the second leading cause of cancer-related mortality among women younger than 40 years. This study comparatively reviewed the demographic, pathologic and molecular features of Early-Onset Breast Cancer (EOBC) reported in Ghana in relation to Late Onset Breast Cancer (LOBC). METHODS: A descriptive, cross-sectional design was used, with purposive sampling of retrospective histopathology data from 2019 to 2021. Reports of core or incision biopsy, Wide Local Excision or Mastectomy with or without axillary lymph node dissection specimen and matched immunohistochemistry reports were merged into a single file and analysed with SPSS v. 20.0. Descriptive statistics of frequencies and percentages were used to describe categorical variables. Cross-tabulation and chi-square test was done at a 95% confidence interval with significance established at p < 0.05. RESULTS: A total of 2418 cases were included in the study with 20.2% (488 cases) being EOBCs and 79.8% (1930 cases) being LOBCs. The median age at diagnosis was 34.66 (IQR: 5.55) in the EOBC group (< 40 years) and 54.29 (IQR: 16.86) in the LOBC group (≥ 40 years). Invasive carcinoma-No Special Type was the commonest tumour type with grade III tumours being the commonest in both categories of patients. Perineural invasion was the only statistically significant pathologic parameter with age. EOBC was associated with higher DCIS component (24.8% vs 21.6%), lower hormone-receptor-positive status (52.30% vs 55.70%), higher proliferation index (Ki-67 > 20: 82.40% vs 80.30%) and a higher number of involved lymph nodes (13.80% vs 9.00%). Triple-Negative Breast cancer (26.40% vs 24.30%) was the most predominant molecular subtype of EOBC. CONCLUSION: EOBCs in our setting are generally more aggressive with poorer prognostic histopathological and molecular features when compared with LOBCs. A larger study is recommended to identify the association between relevant pathological features and early onset breast cancer in Ghana. Again, further molecular and genetic studies to understand the molecular genetic drivers of the general poorer pathological features of EOBCs and its relation to patient outcome in our setting is needed.

Identifying deprived "slum" neighbourhoods in the Greater Accra Metropolitan Area of Ghana using census and remote sensing data.

Background: Identifying urban deprived areas, including slums, can facilitate more targeted planning and development policies in cities to reduce socio-economic and health inequities, but methods to identify them are often ad-hoc, resource intensive, and cannot keep pace with rapidly urbanizing communities. Objectives: We apply a spatial modelling approach to identify census enumeration areas (EAs) in the Greater Accra Metropolitan Area (GAMA) of Ghana with a high probability of being a deprived area using publicly available census and remote sensing data. Methods: We obtained United Nations (UN) supported field mapping data that identified deprived "slum" areas in Accra's urban core, data on housing and population conditions from the most recent census, and remotely sensed data on environmental conditions in the GAMA. We first fitted a Bayesian logistic regression model on the data in Accra's urban core (n=2,414 EAs) that estimated the relationship between housing, population, and environmental predictors and being a deprived area according to the UN's deprived area assessment. Using these relationships, we predicted the probability of being a deprived area for each of the 4,615 urban EAs in GAMA. Results: 899 (19%) of the 4,615 urban EAs in GAMA, with an estimated 745,714 residents (22% of its urban population), had a high predicted probability (≥80%) of being a deprived area. These deprived EAs were dispersed across GAMA and relatively heterogeneous in their housing and environmental conditions, but shared some common features including a higher population density, lower elevation and vegetation abundance, and less access to indoor piped water and sanitation. Conclusion: Our approach using ubiquitously available administrative and satellite data can be used to identify deprived neighbourhoods where interventions are warranted to improve living conditions, and track progress in achieving the Sustainable Development Goals aiming to reduce the population living in unsafe or vulnerable human settlements.

The effects of dietary microbial 6-phytase on growth parameters, intestinal morphometric properties and selected intestinal genes expression in rainbow trout (Oncorhynchus mykiss, Walbaum 1876).

This study investigated the effects of dietary 6-phytase, produced by a genetically modified Komagataella phaffii, on growth performance, feed utilisation, flesh quality, villus morphometric properties, and intestinal mRNA expression in rainbow trout. Six iso-nitrogenous, iso-lipidic, and iso-caloric diets were formulated and fed to triplicate groups of juvenile rainbow trout weighing 32.57 ± 0.36 g (mean ± SD) for 90 days. The dietary treatments included two positive controls (PC), one formulated with 400 g/kg of fish meal named T1, and the other formulated with 170 g/kg of fish meal plus 1% avP derived from monocalcium phosphate named T2. The remaining dietary treatments consisted of a negative control (NC) formulated with 170 g/kg of fish meal (T3), NC+ 750, NC+ 1500, and NC+ 3000 OTU/kg levels of phytase designated as T4, T5, and T6 diets respectively. Compared to T1, weight gain (WG) increased by 16.29, 13.71 and 11.66% in T4, T5 and T6, respectively (p < 0.05). Feed conversion ratio (FCR) was lowered by 3.2 and 0.8% in T4 and T5 compared to T1 (p < 0.05). WG, feed intake (FI), FCR, final body length, bone ash, bone ash P, and intestinal morphometry were negatively affected in T3 fed fish (p < 0.05). Whole-body fish nutrient, bone ash, bone ash phosphorus (P) compositions and mucosal villus morphometric properties improved in rainbow trout fed diets supplemented with phytase dose ranging from 750-3000 OTU. Bone ash increased by 6.12% in T5 compared to T1 (p < 0.05). Phytase inclusion enhanced the profitability of feeding juvenile rainbow trout such diets as it reduced the feed price and economic conversion rate. Dietary inclusion of phytase down-regulated mRNA expression of genes responsible for fatty acid synthesis and lipogenesis in juvenile rainbow trout. Dietary phytase up-regulated the mRNA expression of genes (SLC4A11 and ATP1A3A) responsible for nutrient uptake and down-regulated intestinal expression of MUCIN 5AC-like genes (mucus secreting genes) in juvenile rainbow trout. Along with improving performance parameters, the inclusion of phytase in rainbow trout diet containing plant-based protein sources, can preserve intestinal morphology by regulating the mRNA expression of genes responsible for fatty acid synthesis, lipogenesis and nutrient uptake and transport.

Spatial distribution of Hg in Pra River Basin, Southwestern Ghana using HF acid combination method.

The study assessed the spatial distribution of total mercury (THg) in soils, sediments, mining wastes, and Au-rich Hg-contaminated tailings from artisanal and small-scale gold mining (ASGM) from Offin, Lower and Upper Pra, Birim, and Anum Rivers, Pra River Basin, Southwestern Ghana. THg measurement using Cold Vapor Atomic Absorption Spectrometry (CVAAS) after acid digestion with HNO3/HCl/HF and k0-INAA, as a reference method, and both provided comparable results. A digestion method, HNO3/HClO2/H2SO4 acid mixture before CVAAS provided lower results, which indicates that the use of HF is of fundamental importance in THg analysis based on acid digestion and its omission may significantly underestimate the presence of Hg in soils and sediments. THg in soils, sediments, Au-rich Hg-contaminated tailings, and mining wastes from the river basin were liberated into a solution for measurement using HNO3/HCl/HF. The study revealed Offin and Lower Pra Rivers showed high distribution (ranges; mg Hg kg-1) of THg in soils (103-770) and sediments (0.20-20.8), respectively; Upper Pra and Anum rivers showed the lowest THg in soils (2.20-3.20) and sediments (0.004-0.02), respectively. About 76.0% of THg in sediments was lower than the USEPA guideline of 0.2 mg Hg kg-1. The highest mean THg (mg Hg kg-1) in Au-rich Hg-contaminated tailings (1673 ± 4.8, n = 4) and mining wastes (17.3-21.5) were from the river Offin. The study showed Offin (Dunkwa-on-Offin site 1) and Lower Pra (Beposo Township) rivers are Hg hotspots that need attention.

The distribution of covert microbial natural enemies of a globally invasive crop pest, fall armyworm, in Africa: Enemy release and spillover events.

Invasive species pose a significant threat to biodiversity and agriculture world-wide. Natural enemies play an important part in controlling pest populations, yet we understand very little about the presence and prevalence of natural enemies during the early invasion stages. Microbial natural enemies of fall armyworm Spodoptera frugiperda are known in its native region, however, they have not yet been identified in Africa where fall armyworm has been an invasive crop pest since 2016. Larval samples were screened from Malawi, Rwanda, Kenya, Zambia, Sudan and Ghana for the presence of four different microbial natural enemies; two nucleopolyhedroviruses, Spodoptera frugiperda NPV (SfMNPV) and Spodoptera exempta NPV (SpexNPV); the fungal pathogen Metarhizium rileyi; and the bacterium Wolbachia. This study aimed to identify which microbial pathogens are present in invasive fall armyworm, and determine the geographical, meteorological and temporal variables that influence prevalence. Within 3 years of arrival, fall armyworm was exposed to all four microbial natural enemies. SfMNPV probably arrived with fall armyworm from the Americas, but this is the first putative evidence of host spillover from Spodoptera exempta (African armyworm) to fall armyworm for the endemic pathogen SpexNPV and for Wolbachia. It is also the first confirmed incidence of M. rileyi infecting fall armyworm in Africa. Natural enemies were localised, with variation being observed both nationally and temporally. The prevalence of SfMNPV (the most common natural enemy) was predominantly explained by variables associated with the weather; declining with increasing rainfall and increasing with temperature. However, virus prevalence also increased as the growing season progressed. The infection of an invasive species with a natural enemy from its native range and novel pathogens specific to its new range has important consequences for understanding the population ecology of invasive species and insect-pathogen interactions. Additionally, while it is widely known that temporal and geographic factors affect insect populations, this study reveals that these are important in understanding the distribution of microbial natural enemies associated with invasive pests during the early stages of invasion, and provide baseline data for future studies.

Spatial modelling and inequalities of environmental noise in Accra, Ghana.

Noise pollution is a growing environmental health concern in rapidly urbanizing sub-Saharan African (SSA) cities. However, limited city-wide data constitutes a major barrier to investigating health impacts as well as implementing environmental policy in this growing population. As such, in this first of its kind study in West Africa, we measured, modelled and predicted environmental noise across the Greater Accra Metropolitan Area (GAMA) in Ghana, and evaluated inequalities in exposures by socioeconomic factors. Specifically, we measured environmental noise at 146 locations with weekly (n = 136 locations) and yearlong monitoring (n = 10 locations). We combined these data with geospatial and meteorological predictor variables to develop high-resolution land use regression (LUR) models to predict annual average noise levels (LAeq24hr, Lden, Lday, Lnight). The final LUR models were selected with a forward stepwise procedure and performance was evaluated with cross-validation. We spatially joined model predictions with national census data to estimate population levels of, and potential socioeconomic inequalities in, noise levels at the census enumeration-area level. Variables representing road-traffic and vegetation explained the most variation in noise levels at each site. Predicted day-evening-night (Lden) noise levels were highest in the city-center (Accra Metropolis) (median: 64.0 dBA) and near major roads (median: 68.5 dBA). In the Accra Metropolis, almost the entire population lived in areas where predicted Lden and night-time noise (Lnight) surpassed World Health Organization guidelines for road-traffic noise (Lden <53; and Lnight <45). The poorest areas in Accra also had significantly higher median Lden and Lnight compared with the wealthiest ones, with a difference of ∼5 dBA. The models can support environmental epidemiological studies, burden of disease assessments, and policies and interventions that address underlying causes of noise exposure inequalities within Accra.

Neighbourhood, Built Environment and Children's Outdoor Play Spaces in Urban Ghana: Review of Policies and Challenges.

Although a great deal of research work has been done by social scientists on walkability and playability, the focus to a large extent has been on the global north. Research work on the urban built environment and children's play has not engaged Africa in general and Ghana in particular. More importantly, there is limited evidence of policies in terms of community-based practices and governmental policies and programmes for the promotion of play. The limited effort in promoting physical activities have to a large extent focused on walkability, yet evidence to date indicates that walking only constitutes a small proportion of the physical activities of children. This is against the backdrop of growing urbanization and the increasing reported incidence of sedentary lifestyles, less physical activity and obesity among children and the youth. Our main objective in this paper is to contribute to the literature on Ghana, and by extension Sub-Saharan Africa, by examining the extent to which playability features in city and national policies and strategies in urban Ghana. We conclude that while there is dearth of public policies on children's play, with the situation in communities compounded by weak city government capacity to plan, implement and enforce development control to protect open spaces for children's play and recreational purposes. The paper recommends a change in policy and practice on creating spaces in urban built-environments for children's play in urban Ghana.

Spatial heterogeneity in drinking water sources in the Greater Accra Metropolitan Area (GAMA), Ghana.

Universal access to safe drinking water is essential to population health and well-being, as recognized in the Sustainable Development Goals (SDG). To develop targeted policies which improve urban access to improved water and ensure equity, there is the need to understand the spatial heterogeneity in drinking water sources and the factors underlying these patterns. Using the Shannon Entropy Index and the Index of Concentration at the Extremes at the enumeration area level, we analyzed census data to examine the spatial heterogeneity in drinking water sources and neighborhood income in the Greater Accra Metropolitan Area (GAMA), the largest urban agglomeration in Ghana. GAMA has been a laboratory for studying urban growth, economic security, and other concomitant socio-environmental and demographic issues in the recent past. The current study adds to this literature by telling a different story about the spatial heterogeneity of GAMA's water landscape at the enumeration area level. The findings of the study reveal considerable geographical heterogeneity and inequality in drinking water sources not evidenced in previous studies. We conclude that heterogeneity is neither good nor bad in GAMA judging by the dominance of both piped water sources and sachet water (machine-sealed 500-ml plastic bag of drinking water). The lessons from this study can be used to inform the planning of appropriate localized solutions targeted at providing piped water sources in neighborhoods lacking these services and to monitor progress in achieving universal access to improved drinking water as recognized in the SDG 6 and improving population health and well-being.

Loops and Building Blocks: a Knowledge co-Production Framework for Equitable Urban Health.

This paper sets out a structured process for the co-production of knowledge between researchers and societal partners and illustrates its application in an urban health equity project in Accra, Ghana. The main insight of this approach is that research and knowledge co-production is always partial, both in the sense of being incomplete, as well as being circumscribed by the interests of participating researchers and societal partners. A second insight is that project-bound societal engagement takes place in a broader context of public and policy debate. The approach to co-production described here is formed of three recursive processes: co-designing, co-analysing, and co-creating knowledge. These 'co-production loops' are themselves iterative, each representing a stage of knowledge production. Each loop is operationalized through a series of research and engagement practices, which we call building blocks. Building blocks are activities and interaction-based methods aimed at bringing together a range of participants involved in joint knowledge production. In practice, recursive iterations within loops may be limited due of constraints on time, resources, or attention. We suggest that co-production loops and building blocks are deployed flexibly.

Face Mask Use Among Commercial Drivers During the COVID-19 Pandemic in Accra, Ghana.

The paper contributes to unravelling the perceptions of urban commercial drivers regarding their vulnerability to catching the SARS-CoV-2 virus while at work. It further examines how the perception of vulnerability influences personal use of face masks by drivers, as well as on their insistence on appropriate masking behaviour by other persons on-board public transport. Overcrowding and unsanitary conditions in informal public transport in Africa could facilitate the spread of the corona virus. However, the use of face masks, among other enhanced mitigation measures significantly contain and minimize the spread of the virus. Primary data, obtained through surveys at five major public transport terminals in Accra, was analysed and interpreted using the Health Belief Model as an explanatory framework. Results indicate that most drivers have a high vulnerability perception to Covid-19. It further emerged that older drivers, in particular, consistently wore face masks and insisted on other persons in their commercial vehicles to follow suit. Socio-demographic factors, and the need to ensure one's personal safety and those of loved ones were critical determinants of face mask use among surveyed drivers. The study thus recommends that public awareness campaigns should strategically focus attention on the younger generation of drivers (i.e. 18-39 years) who perceived themselves to be immune to the SARS-CoV-2 virus. Also, the collaborative efforts of state and non-state actors, like the transport operator unions, must be further strengthened if the gains made so far against Covid-19 is to be sustained.

Short-Term Changes in Behaviors Resulting from COVID-19-Related Social Isolation and Their Influences on Mental Health in Ghana.

This study assessed the behavioral outcomes of Coronavirus 2019 (COVID-19) social distancing protocols and their influences on mental health. An online survey hosted by Survey Monkey was utilized to collect data from residents of three Ghanaian cities of Accra, Kumasi and Tamale. A total of 621 surveys were analyzed, with a sensitivity analysis utilized to select covariates for the regression model. The average age of participants was about 36 years. Findings indicate that reduced physical activity time and a change in sexual activity and smoking frequency are some short-term changes in behavior resulting from social isolation during the lockdown. An increase in sedentary behavior had a negative influence on mental health. For the most part, changes in behaviors in the short-term were associated with lower mental health scores. The study implied that COVID-19 social distancing measures should be implemented alongside public education for discouraging unhealthy changes in behaviors.

Population awareness and attitudes toward waste-related health risks in Accra, Ghana.

Despite significant knowledge about the potential health hazards of waste, there are few studies in African cities that investigate awareness of health issues related to waste management, although such research is needed to lower population exposure. This paper examines the case study of Accra in Ghana, a city dealing with serious health and pollution problems. Three focus groups and 157 households in Accra were surveyed on household waste disposal and awareness of waste-related health hazards. Surveyed households had limited knowledge of waste-related health hazards in their neighbourhoods. Although the households reported diseases that could be associated with environmental factors linked to waste management, 87% of all surveyed households did not think that someone in their household could have fallen ill of a disease that can be related to waste. In middle- and high-income neighbourhoods, waste burning increases substantially when waste is not collected.

Geographical Inequalities and Social and Environmental Risk Factors for Under-Five Mortality in Ghana in 2000 and 2010: Bayesian Spatial Analysis of Census Data.

BACKGROUND: Under-five mortality is declining in Ghana and many other countries. Very few studies have measured under-five mortality-and its social and environmental risk factors-at fine spatial resolutions, which is relevant for policy purposes. Our aim was to estimate under-five mortality and its social and environmental risk factors at the district level in Ghana. METHODS AND FINDINGS: We used 10% random samples of Ghana's 2000 and 2010 National Population and Housing Censuses. We applied indirect demographic methods and a Bayesian spatial model to the information on total number of children ever born and children surviving to estimate under-five mortality (probability of dying by 5 y of age, 5q0) for each of Ghana's 110 districts. We also used the census data to estimate the distributions of households or persons in each district in terms of fuel used for cooking, sanitation facility, drinking water source, and parental education. Median district 5q0 declined from 99 deaths per 1,000 live births in 2000 to 70 in 2010. The decline ranged from <5% in some northern districts, where 5q0 had been higher in 2000, to >40% in southern districts, where it had been lower in 2000, exacerbating existing inequalities. Primary education increased in men and women, and more households had access to improved water and sanitation and cleaner cooking fuels. Higher use of liquefied petroleum gas for cooking was associated with lower 5q0 in multivariate analysis. CONCLUSIONS: Under-five mortality has declined in all of Ghana's districts, but the cross-district inequality in mortality has increased. There is a need for additional data, including on healthcare, and additional environmental and socioeconomic measurements, to understand the reasons for the variations in mortality levels and trends.

The Local Food Environment and Body Mass Index among the Urban Poor in Accra, Ghana.

Obesity in the sub-Saharan Africa region has been portrayed as a problem of affluence, partly because obesity has been found to be more common in urban areas and among the rich. Recent findings, however, reveal rising prevalence among the poor particularly the urban poor. A growing body of literature mostly in Western countries shows that obesity among the poor is partly the result of an obesogenic-built environment. Such studies are lacking in the African context. This study examines the characteristics of the local food environment in an urban poor setting in Accra, Ghana and further investigates the associated risk of obesity for residents. Data on the local food environment was collected using geographic positioning system (GPS) technology. The body mass indices (BMI) of females (15-49 years) and males (15-59 years) were calculated from measured weight and height. Data on the socio-demographic characteristics and lifestyle behaviors of respondents was also collected through a household survey. Spatial analysis tools were used to examine the characteristics of the local food environment while the influence of the food environment on BMI was examined using a two-level multilevel model. The measures of the food environment constituted the level 2 factors while individual socio-demographic characteristics and lifestyle behaviors constituted the level 1 factors. The local food environment in the study communities is suggestive of an obesogenic food environment characterized by an abundance of out-of-home cooked foods, convenience stores, and limited fruits and vegetables options. The results of the multilevel analysis reveal a 0.2 kg/m(2) increase in BMI for every additional convenience store and a 0.1 kg/m(2) reduction in BMI for every out-of-home cooked food place available in the study area after controlling for individual socio-demographic characteristics, lifestyle behaviors, and community characteristics. The findings of this study indicate that the local food environment in urban poor Accra is associated with increased risk of obesity through providing access to convenience stores. In order to reduce the risk of obesity in these urban poor communities, there is the need to regulate the availability of and access to convenience stores while also encouraging healthier offerings in convenience stores.

Prevalence of Inguinal Hernia in Adult Men in the Ashanti Region of Ghana.

BACKGROUND: Inguinal hernia is thought to be common in rural Ghana, though no recent data exist on hernia prevalence in the country. This information is needed to guide policy and increase access to safe hernia repair in Ghana and other low-resource settings. METHODS: Adult men randomly selected from the Barekese sub-district of Ashanti Region, Ghana were examined by surgeons for the presence of inguinal hernia. Men with hernia completed a survey on demographics, knowledge of the disease, and barriers to surgical treatment. RESULTS: A total of 803 participants were examined, while 105 participants completed the survey. The prevalence of inguinal hernia was 10.8 % (95 % CI 8.0, 13.6 %), and 2.2 % (95 % CI 0, 5.4 %) of participants had scars indicative of previous repair, making the overall prevalence of treated and untreated inguinal hernia 13.0 % (95 % CI 10.2, 15.7 %). Prevalence of inguinal hernia increased with age; 35.4 % (95 % CI 23.6, 47.2 %) of men aged 65 and older had inguinal hernia. Untreated inguinal hernia was associated with lower socio-economic status. Of those with inguinal hernia, 52.4 % did not know the cause of hernia. The most common reason cited for failing to seek medical care was cost (48.2 %). CONCLUSION: Although inguinal hernia is common among adult men living in rural Ghana, surgical repair rates are low. We propose a multi-faceted public health campaign aimed at increasing access to safe hernia repair in Ghana. This approach includes a training program of non-surgeons in inguinal hernia repair headed by the Ghana Hernia Society and could be adapted for use in other low-resource settings.

Chemical characterization and source apportionment of household fine particulate matter in rural, peri-urban, and urban West Africa.

Household air pollution in sub-Saharan Africa and other developing regions is an important cause of disease burden. Little is known about the chemical composition and sources of household air pollution in sub-Saharan Africa, and how they differ between rural and urban homes. We analyzed the chemical composition and sources of fine particles (PM2.5) in household cooking areas of multiple neighborhoods in Accra, Ghana, and in peri-urban (Banjul) and rural (Basse) areas in The Gambia. In Accra, biomass burning accounted for 39-62% of total PM2.5 mass in the cooking area in different neighborhoods; the absolute contributions were 10-45 µg/m(3). Road dust and vehicle emissions comprised 12-33% of PM2.5 mass. Solid waste burning was also a significant contributor to household PM2.5 in a low-income neighborhood but not for those living in better-off areas. In Banjul and Basse, biomass burning was the single dominant source of cooking-area PM2.5, accounting for 74-87% of its total mass; the relative and absolute contributions of biomass smoke to PM2.5 mass were larger in households that used firewood than in those using charcoal, reaching as high as 463 µg/m(3) in Basse homes that used firewood for cooking. Our findings demonstrate the need for policies that enhance access to cleaner fuels in both rural and urban areas, and for controlling traffic emissions in cities in sub-Saharan Africa.

Household and community poverty, biomass use, and air pollution in Accra, Ghana.

Many urban households in developing countries use biomass fuels for cooking. The proportion of household biomass use varies among neighborhoods, and is generally higher in low socioeconomic status (SES) communities. Little is known of how household air pollution varies by SES and how it is affected by biomass fuels and traffic sources in developing country cities. In four neighborhoods in Accra, Ghana, we collected and analyzed geo-referenced data on household and community particulate matter (PM) pollution, SES, fuel use for domestic and small-commercial cooking, housing characteristics, and distance to major roads. Cooking area PM was lowest in the high-SES neighborhood, with geometric means of 25 (95% confidence interval, 21-29) and 28 (23-33) µg/m(3) for fine and coarse PM (PM(2.5) and PM(2.5-10)), respectively; it was highest in two low-SES slums, with geometric means reaching 71 (62-80) and 131 (114-150) µg/m(3) for fine and coarse PM. After adjustment for other factors, living in a community where all households use biomass fuels would be associated with 1.5- to 2.7-times PM levels in models with and without adjustment for ambient PM. Community biomass use had a stronger association with household PM than household's own fuel choice in crude and adjusted estimates. Lack of regular physical access to clean fuels is an obstacle to fuel switching in low-income neighborhoods and should be addressed through equitable energy infrastructure.

Inequalities in urban air pollution in sub-Saharan Africa: an empirical modeling of ambient NO and NO2 concentrations in Accra, Ghana.

Road traffic has become the leading source of air pollution in fast-growing sub-Saharan African cities. Yet, there is a dearth of robust city-wide data for understanding space-time variations and inequalities in combustion related emissions and exposures. We combined nitrogen dioxide (NO2) and nitric oxide (NO) measurement data from 134 locations in the Greater Accra Metropolitan Area (GAMA), with geographical, meteorological, and population factors in spatio-temporal mixed effects models to predict NO2 and NO concentrations at fine spatial (50 m) and temporal (weekly) resolution over the entire GAMA. Model performance was evaluated with 10-fold cross-validation (CV), and predictions were summarized as annual and seasonal (dusty [Harmattan] and rainy [non-Harmattan]) mean concentrations. The predictions were used to examine population distributions of, and socioeconomic inequalities in, exposure at the census enumeration area (EA) level. The models explained 88% and 79% of the spatiotemporal variability in NO2 and NO concentrations, respectively. The mean predicted annual, non-Harmattan and Harmattan NO2 levels were 37 (range: 1-189), 28 (range: 1-170) and 50 (range: 1-195) µg m-3, respectively. Unlike NO2, NO concentrations were highest in the non-Harmattan season (41 [range: 31-521] µg m-3). Road traffic was the dominant factor for both pollutants, but NO2 had higher spatial heterogeneity than NO. For both pollutants, the levels were substantially higher in the city core, where the entire population (100%) was exposed to annual NO2 levels exceeding the World Health Organization (WHO) guideline of 10 µg m-3. Significant disparities in NO2 concentrations existed across socioeconomic gradients, with residents in the poorest communities exposed to levels about 15 µg m-3 higher compared with the wealthiest (p < 0.001). The results showed the important role of road traffic emissions in air pollution concentrations in the GAMA, which has major implications for the health of the city's poorest residents. These data could support climate and health impact assessments as well as policy evaluations in the city.

Heteroepitaxial growth of GaSb nanotrees with an ultra-low reflectivity in a broad spectral range.

We report on the growth of GaSb nanotrees on InAs { ̅1 ̅1 ̅1}(B) substrates by chemical beam epitaxy. GaSb nanotrees form by the nucleation of Ga droplets on the surface of < ̅1 ̅1 ̅1>(B) oriented GaSb nanowires followed by the epitaxial growth of branches catalyzed by these Ga droplets. In the tip region, the trunks of the GaSb nanotrees are periodically twinned, which is attributed to a change of the effective V/III ratio at the later stage of growth as a consequence of the change in surface structure. The reflectivity of a forest of nanotrees was measured for a broad spectral range and compared to the reflectivity of a GaSb ( ̅1 ̅1 ̅1)(B) wafer and of GaSb nanowires. At wavelengths from 500 to 1700 nm, the presence of GaSb nanotrees decreased the reflection by three orders of magnitude compared to a blank GaSb substrate.

C-kit-negative transmural gastrointestinal stromal tumor in the stomach: A rare case of upper GI bleeding in Ghana.

Upper GI bleeding from GIST is rare in Africa. The C-kit-negative variant is uncommon worldwide. We report a case of a 42-year-old woman managed for upper GI bleeding secondary to stomach GIST, negative for CD117 but positive for DOG 1 and CD 34. The 1-year postsurgery review is uneventful.