Analysis of Ozone (O3) and Erythemal UV (EUV) measured by TOMS in the equatorial African belt

We presented time series of total ozone column amounts (TOCAs) and erythemal UV (EUV) doses derived from measurements by TOMS (Total Ozone Mapping Spectrometer) instruments on board the Nimbus-7 (N7) and the Earth Probe (EP) satellites for three locations within the equatorial African belt for the period 1979 to 2000. The locations were Dar-es-Salaam (6.8° S, 39.26° E) in Tanzania, Kampala (0.19° N, 32.34° E) in Uganda, and Serrekunda (13.28° N, 16.34° W) in Gambia. Equatorial Africa has high levels of UV radiation, and because ozone shields UV radiation from reaching the Earth’s surface, there is a need to monitor TOCAs and EUV doses. In this paper we investigated the trend of TOCAs and EUV doses, the effects of annual and solar cycles on TOCAs, as well as the link between lightning and ozone production in the equatorial African belt. We also compared clear-sky simulated EUV doses with the corresponding EUV doses derived from TOMS measurements. The TOCAs were found to vary in the ranges 243 DU − 289 DU, 231 DU − 286 DU, and 236 DU − 296 DU, with mean values of 266.9 DU, 260.9 DU, and 267.8 DU for Dar-es-Salaam, Kampala and Serrekunda, respectively. Daily TOCA time series indicated that Kampala had the lowest TOCA values, which we attributed to the altitude effect. There were two annual ozone peaks in Dar-es-Salaam and Kampala, and one annual ozone peak in Serrekunda. The yearly TOCA averages showed an oscillation within a five-year period. We also found that the EUV doses were stable at all three locations for the period 1979−2000, and that Kampala and Dar-es-Salaam were mostly cloudy throughout the year, whereas Serrekunda was mostly free from clouds. It was also found that clouds were among the major factors determining the level of EUV reaching the Earth´s surface. Finally, we noted that during rainy seasons, horizontal advection effects augmented by lightning activity may be responsible for enhanced ozone production in the tropics.publishedVersio

A new algorithm for simultaneous retrieval of aerosols and marine parameters

We present an algorithm for simultaneous retrieval of aerosol and marine parameters in coastal waters. The algorithm is based on a radiative transfer forward model for a coupled atmosphere-ocean system, which is used to train a radial basis function neural network (RBF-NN) to obtain a fast and accurate method to compute radiances at the top of the atmosphere (TOA) for given aerosol and marine input parameters. The inverse modelling algorithm employs multidimensional unconstrained non-linear optimization to retrieve three marine parameters (concentrations of chlorophyll and mineral particles, as well as absorption by coloured dissolved organic matter (CDOM)), and two aerosol parameters (aerosol fine-mode fraction and aerosol volume fraction). We validated the retrieval algorithm using synthetic data and found it, for both low and high sun, to predict each of the five parameters accurately, both with and without white noise added to the top of the atmosphere (TOA) radiances. When varying the solar zenith angle (SZA) and retraining the RBF-NN without noise added to the TOA radiance, we found the algorithm to predict the CDOM absorption, chlorophyll concentration, mineral concentration, aerosol fine-mode fraction, and aerosol volume fraction with correlation coefficients greater than 0.72, 0.73, 0.93, 0.67, and 0.87, respectively, for 45∘≤∘≤ SZA ≤ 75∘∘. By adding white Gaussian noise to the TOA radiances with varying values of the signal-to-noise-ratio (SNR), we found the retrieval algorithm to predict CDOM absorption, chlorophyll concentration, mineral concentration, aerosol fine-mode fraction, and aerosol volume fraction well with correlation coefficients greater than 0.77, 0.75, 0.91, 0.81, and 0.86, respectively, for high sun and SNR ≥ 95.publishedVersio

Erysipelothrix rhusiopathiae infection in pigs, pork and raw pork handlers in Kamuli District, Eastern Uganda

Erysipelothrix rhusiopathiae is a zoonotic ubiquitous gram-positive bacterium, which causes erysipelas in swine, mammals, birds and erysipeloid in humans. People in contact with animals, animal products or animal wastes are at greatest risk. From June 2013 to December 2015, a multidisciplinary risk assessment was conducted to identify the risks associated with E. rhusiopathiae along the pig value chain in Kamuli District, Eastern Uganda. Quantitative and qualitative methods of data collection were employed. Serum from 460 pigs and 100 fresh pork samples and human EDTA blood was gathered from 302 raw pork handlers (butchers, abattoir workers and housewives), for microbiology cultures and serology. Six focus group discussions were conducted with 26 butchers/abattoir workers and with 26 housewives. Three key informant interviews were conducted with a health assistant, veterinary officer and a nursing officer. Overall, 308/460 (67%) of the pig sera carried antibodies against E. rhusiopathiae. Forty-five percent (45/100, 45%) of the fresh pork samples were contaminated with E. rhusiopathiae and 30/302 (9.9%) of the raw pork handlers were positive for infection with E. rhusiopathiae. The mean age of the raw pork handlers was 38 years, 21/30 (70%) of men were infected compared to 9/30(30%) of the women. The main risk factor for the infection was the type of raw pork handler. Of the abattoir workers 14/38 (47%) were positive, 9/59 (30%) of the butchers and 7/205 (23.3%) of the housewives were infected with E.rhusiopathiae. This is the first ever report of E. rhusiopathiae in pigs and humans in Uganda and East Africa. Previously, the acute form of swine erysipelas may have been confused for other diseases in pigs reported in Uganda which are characterized acute symptoms such as sudden death (for example, African swine fever). We recommend increasing awareness of the disease among animal and human practitioners as treatment is easy and available and vaccination is possible. However, the disease is still unknown to local veterinarians, clinical doctors, meat inspectors, butchers and laboratory personnel. Proper hygiene, regular pork inspection, use of protective wear among people working/ in contact with animals should be promoted. The study was conducted under the Safe Food, Fair Food project led by the International Livestock Research Institute and carried out with the financial support of the Federal Ministry for Economic Cooperation and Development, Germany, and the CGIAR Research Program on Agriculture for Nutrition and Health, led by the International Food Policy Research Institute

CDOM absorption properties of natural water bodies along extreme environmental gradients

We present absorption properties of colored dissolved organic matter (CDOM) sampled in six different water bodies along extreme altitudinal, latitudinal, and trophic state gradients. Three sites are in Norway: the mesotrophic Lysefjord (LF), Samnangerfjord (SF), and Røst Coastal Water (RCW); two sites are in China: the oligotrophic Lake Namtso (LN) and the eutrophic Bohai Sea (BS); and one site is in Uganda: the eutrophic Lake Victoria (LV). The site locations ranged from equatorial to subarctic regions, and they included water types from oligotrophic to eutrophic and altitudes from 0 m to 4700 m. The mean CDOM absorption coefficients at 440 nm [ a CDOM (440) aCDOM(440) ] and 320 nm [ a CDOM (320) aCDOM(320) ] varied in the ranges 0.063–0.35 m −1 −1 and 0.34–2.28 m −1 −1 , respectively, with highest values in LV, Uganda and the lowest in the high-altitude LN, Tibet. The mean spectral slopes S 280−500 S280−500 and S 350−500 S350−500 were found to vary in the ranges of 0.017–0.032 nm −1 −1 and 0.013–0.015 nm −1 −1 , respectively. The highest mean value for S 280−500 S280−500 as well as the lowest mean value for S 350−500 S350−500 were found in LN. Scatter plots of S 280−500 S280−500 versus a CDOM (440) aCDOM(440) and a CDOM (320) aCDOM(320) values ranges revealed a close connection between RCW, LF, and SF on one side, and BS and LV on the other side. CDOM seems to originate from terrestrial sources in LF, SF, BS, and LV, while RCW is characterized by autochthonous-oceanic CDOM, and LN by autochthonous CDOM. Photobleaching of CDOM is prominent in LN, demonstrated by absorption towards lower wavelengths in the UV spectrum. We conclude that high altitudes, implying high levels of UV radiation and oligotrophic water conditions are most important for making a significant change in CDOM absorption properties.publishedVersio

Perspectives on key principles of generalist medical practice in public service in sub-saharan africa: a qualitative study

The original publication is available at http://www.biomedcentral.comAbstract Background: The principles and practice of Family Medicine that arose in developed Western countries have been imported and adopted in African countries without adequate consideration of their relevance and appropriateness to the African context. In this study we attempted to elicit a priori principles of generalist medical practice from the experience of long-serving medical officers in a variety of African counties, through which we explored emergent principles of Family Medicine in our own context. Methods A descriptive study design was utilized, using qualitative methods. 16 respondents who were clinically active medical practitioners, working as generalists in the public services or non-profit sector for at least 5 years, and who had had no previous formal training or involvement in academic Family Medicine, were purposively selected in 8 different countries in southern, western and east Africa, and interviewed. Results The respondents highlighted a number of key issues with respect to the external environment within which they work, their collective roles, activities and behaviours, as well as the personal values and beliefs that motivate their behaviour. The context is characterized by resource constraints, high workload, traditional health beliefs, and the difficulty of referring patients to the next level of care. Generalist clinicians in sub-Saharan Africa need to be competent across a wide range of clinical disciplines and procedural skills at the level of the district hospital and clinic, in both chronic and emergency care. They need to understand the patient's perspective and context, empowering the patient and building an effective doctor-patient relationship. They are also managers, focused on coordinating and improving the quality of clinical care through teamwork, training and mentoring other health workers in the generalist setting, while being life-long learners themselves. However, their role in the community, was found to be more aspirational than real. Conclusions The study derived a set of principles for the practice of generalist doctors in sub-Saharan Africa based on the reported activities and approaches of the respondents. Patient-centred care using a biopsychosocial approach remains as a common core principle despite wide variations in context. Procedural and hospital care demands a higher level of skills particularly in rural areas, and a community orientation is desirable, but not widely practiced. The results have implications for the postgraduate training of family physicians in sub-Saharan Africa, and highlight questions regarding the realization of community-orientated primary care.Publishers' Versio

Exome sequencing implicates genetic disruption of prenatal neuro-gliogenesis in sporadic congenital hydrocephalus

Congenital hydrocephalus (CH), characterized by enlarged brain ventricles, is considered a disease of excessive cerebrospinal fluid (CSF) accumulation and thereby treated with neurosurgical CSF diversion with high morbidity and failure rates. The poor neurodevelopmental outcomes and persistence of ventriculomegaly in some post-surgical patients highlight our limited knowledge of disease mechanisms. Through whole-exome sequencing of 381 patients (232 trios) with sporadic, neurosurgically treated CH, we found that damaging de novo mutations account for >17% of cases, with five different genes exhibiting a significant de novo mutation burden. In all, rare, damaging mutations with large effect contributed to ~22% of sporadic CH cases. Multiple CH genes are key regulators of neural stem cell biology and converge in human transcriptional networks and cell types pertinent for fetal neuro-gliogenesis. These data implicate genetic disruption of early brain development, not impaired CSF dynamics, as the primary pathomechanism of a significant number of patients with sporadic CH

Transcriptomes of <i>Trypanosoma brucei</i> rhodesiense from sleeping sickness patients, rodents and culture:Effects of strain, growth conditions and RNA preparation methods

All of our current knowledge of African trypanosome metabolism is based on results from trypanosomes grown in culture or in rodents. Drugs against sleeping sickness must however treat trypanosomes in humans. We here compare the transcriptomes of Trypanosoma brucei rhodesiense from the blood and cerebrospinal fluid of human patients with those of trypanosomes from culture and rodents. The data were aligned and analysed using new user-friendly applications designed for Kinetoplastid RNA-Seq data. The transcriptomes of trypanosomes from human blood and cerebrospinal fluid did not predict major metabolic differences that might affect drug susceptibility. Usefully, there were relatively few differences between the transcriptomes of trypanosomes from patients and those of similar trypanosomes grown in rats. Transcriptomes of monomorphic laboratory-adapted parasites grown in in vitro culture closely resembled those of the human parasites, but some differences were seen. In poly(A)-selected mRNA transcriptomes, mRNAs encoding some protein kinases and RNA-binding proteins were under-represented relative to mRNA that had not been poly(A) selected; further investigation revealed that the selection tends to result in loss of longer mRNAs

Effectiveness of kangaroo mother care before clinical stabilisation versus standard care among neonates at five hospitals in Uganda (OMWaNA): a parallel-group, individually randomised controlled trial and economic evaluation

BACKGROUND: Preterm birth is the leading cause of death in children younger than 5 years worldwide. WHO recommends kangaroo mother care (KMC); however, its effects on mortality in sub-Saharan Africa and its relative costs remain unclear. We aimed to compare the effectiveness, safety, costs, and cost-effectiveness of KMC initiated before clinical stabilisation versus standard care in neonates weighing up to 2000 g. METHODS: We conducted a parallel-group, individually randomised controlled trial in five hospitals across Uganda. Singleton or twin neonates aged younger than 48 h weighing 700-2000 g without life-threatening clinical instability were eligible for inclusion. We randomly assigned (1:1) neonates to either KMC initiated before stabilisation (intervention group) or standard care (control group) via a computer-generated random allocation sequence with permuted blocks of varying sizes, stratified by birthweight and recruitment site. Parents, caregivers, and health-care workers were unmasked to treatment allocation; however, the independent statistician who conducted the analyses was masked. After randomisation, neonates in the intervention group were placed prone and skin-to-skin on the caregiver's chest, secured with a KMC wrap. Neonates in the control group were cared for in an incubator or radiant heater, as per hospital practice; KMC was not initiated until stability criteria were met. The primary outcome was all-cause neonatal mortality at 7 days, analysed by intention to treat. The economic evaluation assessed incremental costs and cost-effectiveness from a disaggregated societal perspective. This trial is registered with ClinicalTrials.gov, NCT02811432. FINDINGS: Between Oct 9, 2019, and July 31, 2022, 2221 neonates were randomly assigned: 1110 (50·0%) neonates to the intervention group and 1111 (50·0%) neonates to the control group. From randomisation to age 7 days, 81 (7·5%) of 1083 neonates in the intervention group and 83 (7·5%) of 1102 neonates in the control group died (adjusted relative risk [RR] 0·97 [95% CI 0·74-1·28]; p=0·85). From randomisation to 28 days, 119 (11·3%) of 1051 neonates in the intervention group and 134 (12·8%) of 1049 neonates in the control group died (RR 0·88 [0·71-1·09]; p=0·23). Even if policy makers place no value on averting neonatal deaths, the intervention would have 97% probability from the provider perspective and 84% probability from the societal perspective of being more cost-effective than standard care. INTERPRETATION: KMC initiated before stabilisation did not reduce early neonatal mortality; however, it was cost-effective from the societal and provider perspectives compared with standard care. Additional investment in neonatal care is needed for increased impact, particularly in sub-Saharan Africa. FUNDING: Joint Global Health Trials scheme of the Department of Health and Social Care, Foreign, Commonwealth and Development Office, UKRI Medical Research Council, and Wellcome Trust; Eunice Kennedy Shriver National Institute of Child Health and Human Development

Paenibacillus infection with frequent viral coinfection contributes to postinfectious hydrocephalus in Ugandan infants

Postinfectious hydrocephalus (PIH), which often follows neonatal sepsis, is the most common cause of pediatric hydrocephalus worldwide, yet the microbial pathogens underlying this disease remain to be elucidated. Characterization of the microbial agents causing PIH would enable a shift from surgical palliation of cerebrospinal fluid (CSF) accumulation to prevention of the disease. Here, we examined blood and CSF samples collected from 100 consecutive infant cases of PIH and control cases comprising infants with non-postinfectious hydrocephalus in Uganda. Genomic sequencing of samples was undertaken to test for bacterial, fungal, and parasitic DNA; DNA and RNA sequencing was used to identify viruses; and bacterial culture recovery was used to identify potential causative organisms. We found that infection with the bacterium Paenibacillus, together with frequent cytomegalovirus (CMV) coinfection, was associated with PIH in our infant cohort. Assembly of the genome of a facultative anaerobic bacterial isolate recovered from cultures of CSF samples from PIH cases identified a strain of Paenibacillus thiaminolyticus. This strain, designated Mbale, was lethal when injected into mice in contrast to the benign reference Paenibacillus strain. These findings show that an unbiased pan-microbial approach enabled characterization of Paenibacillus in CSF samples from PIH cases, and point toward a pathway of more optimal treatment and prevention for PIH and other proximate neonatal infections