243 research outputs found
Water Management and Supply in a Mining Community â A Case Study of Tarkwa and its Environs
Since mining activities require a lot of water and also increase population of host communities as a result of influx of workers, water resources in mining communities must be efficiently managed. This paper considered the various factors affecting water supply and its distribution in the Tarkwa area, a mining community, to find out the possible reasons for the inadequate water supply to Tarkwa. The maximum flood discharge for a reservoir constructed along the course of the River Bonsa was computed as 81.34 m3 /s using the rational method for the estimation of peak flood flow. The volume of containment of the reservoir was also calculated from hydrographic surveys data to be 25 456 m3. These results were analysedagainst the water demand vis-a-vis the current population growth. Also the condition of the equipment for pumping water both from the reservoir for treatment and after treatment to the storage tanks from where water is supplied to customers were considered together with the capacity of the treatment plant and the booster station at Bonsaso and Tamso respectively. It was concluded that the reservoir has enough water to meet the demand. However, the problem of inadequate supply was traced to non-regular power supply to both the treatment plant and booster station from where customers are served
The phytochemical analysis and antibacterial effects of stem bark extracts of Brachystegia eurycoma harms
Plant based antimicrobials represent a vast potential of untapped sources of medicines. Antimicrobial sensitivity patterns change over time due to resistance developed by microorganisms, underpinning the great need for search of novel antimicrobial drugs. Phytochemical and antibacterial effects of crude aqueous (hot and cold) and alcohol extracts of stem bark of Brachystegia eurycoma was investigated using standard methods. The preliminary phytochemical screening revealed the presence of saponins, alkaloids, steroids and tannins as major components. Also, of the three different extracts tested against four pathogenic bacteria (Sphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Proteus vulgaris), only the cold aqueous extract showed a mild zone of inhibition (3mm) against Escherichia coli, with an MIC of 12.5mg/ml and MBC of 25mg/ml. This suggests that cold aqueous extract of B. eurycoma has antibacterial activity, which might account for its inclusion in traditional herbal preparations in the treatment of wounds and infections.Key words: Brachystegia eurycoma, phytochemical, stem bark, antibacterial, extract
The complete mitochondrial genome of Epomophorus gambianus (Chiroptera: Pteropodidae) and its phylogenetic analysis
The Gambian epauletted fruit bat, Epomophorus gambianus, is widely distributed across sub-Saharan Africa. Its assembled and annotated mitochondrial genome (GenBank accession no. KT963027) is 16,702 bases in length, containing 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes and two non-coding regions: the control region (D-loop) and the origin of light-strand replication (OL). The average base composition is 32.2% A; 27.6% C; 14% G; and 26.1% T. The mitogenome presented a structural composition greatly conserved between members of the Pteropodidae family
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Outcomes of meningococcal serogroup B disease in children after implementation of routine infant 4CMenB vaccination in England: an active, prospective, national surveillance study.
BACKGROUND: In 2015, the UK included 4CMenB, a multi-component, recombinant protein-based vaccine against meningococcal serogroup B (MenB) disease, in the national infant immunisation programme. We aimed to assess the effect of 4CMenB vaccination on the severity of MenB disease presentation and outcomes. METHODS: In this active, prospective, national surveillance study, we used data from the UK Health Security Agency national surveillance of meningococcal disease. We included data from follow-up of children younger than 5 years with laboratory-confirmed MenB disease who were eligible for 4CMenB vaccination with general practice 3-6 months after disease onset. All invasive MenB isolates were tested using the Meningococcal Antigen Typing System to determine whether the isolate was potentially preventable by 4CMenB. Admission to intensive care, death, and, when possible, reported sequelae in survivors were reviewed alongside vaccine status. For the epidemiological analysis, we compared laboratory-confirmed MenB disease cases before 4CMenB implementation (Sept 1, 2010, to March 31, 2015) with those after implementation (Sept 1, 2015, to March 31, 2020). For clinical follow-up and outcomes, we included all children younger than 5 years with laboratory-confirmed MenB disease between Sept 1, 2015, and March 31, 2021. FINDINGS: Between Sept 1, 2015, and March 31, 2021, there were 371 cases of MenB disease in children younger than 5 years, including 256 (69%) in those younger than 1 year and 128 (35%) in those younger than 3 months. After the introduction of 4CMenB, the peak age of patients with MenB disease shifted from 5-6 months to 1-3 months. Overall, 108 (29%) of 371 children were too young for vaccination, unvaccinated, or developed MenB disease within 14 days of the first dose. Of 110 meningococcal strains characterised, 11 (92%) of 12 were potentially preventable by 4CMenB in unvaccinated children compared with 53 (66%) of 80 in partly vaccinated and 11 (69%) of 16 in fully vaccinated children. 78 (21%) of 371 children required intensive care, and the case fatality ratio was 5% (17 of 371), with 11 of 17 deaths occurring before 1 year of age, including seven in infants who were too young (<8 weeks) for vaccination. Of 354 survivors, 57 (16%) had 74 sequelae reported; 45 (61%) of 74 were neurological, 17 (23%) were physical, two (3%) were behavioural or psychological, and ten (14%) were other complications. Prevalence of sequelae was similar in unvaccinated (15 [15%] of 98) and vaccinated (42 [16%] 256) children, as were composite outcomes of death or sequelae, and intensive care or death or sequelae. INTERPRETATION: Cases of MenB disease in vaccine-eligible children declined after 4CMenB implementation, but morbidity in vaccinated and unvaccinated children remained unchanged, highlighting the importance of vaccination to prevent MenB disease. The lower peak age of infants with MenB disease after 4CMenB implementation, with a higher case fatality ratio in young infants, highlights the importance of timely vaccination. FUNDING: UK Health Security Agency
Quantifying within-city inequalities in child mortality across neighbourhoods in Accra, Ghana: a Bayesian spatial analysis
Objective Countries in sub-Saharan Africa suffer the highest rates of child mortality worldwide. Urban areas tend to have lower mortality than rural areas, but these comparisons likely mask large within-city inequalities. We aimed to estimate rates of under-five mortality (U5M) at the neighbourhood level for Ghanaâs Greater Accra Metropolitan Area (GAMA) and measure the extent of intraurban inequalities. Methods We accessed data on >700â000 women aged 25â49 years living in GAMA using the most recent Ghana census (2010). We summarised counts of child births and deaths by five-year age group of women and neighbourhood (n=406) and applied indirect demographic methods to convert the summaries to yearly probabilities of death before age fiveâyears. We fitted a Bayesian spatiotemporal model to the neighbourhood U5M probabilities to obtain estimates for the year 2010 and examined their correlations with indicators of neighbourhood living and socioeconomic conditions. Results U5M varied almost five-fold across neighbourhoods in GAMA in 2010, ranging from 28 (95% credible interval (CrI) 8 to 63) to 138 (95% CrI 111 to 167) deaths per 1000 live births. U5M was highest in neighbourhoods of the central urban core and industrial areas, with an average of 95 deaths per 1000 live births across these neighbourhoods. Peri-urban neighbourhoods performed better, on average, but rates varied more across neighbourhoods compared with neighbourhoods in the central urban areas. U5M was negatively correlated with multiple indicators of improved living and socioeconomic conditions among peri-urban neighbourhoods. Among urban neighbourhoods, correlations with these factors were weaker or, in some cases, reversed, including with median household consumption and womenâs schooling. Conclusion Reducing child mortality in high-burden urban neighbourhoods in GAMA, where a substantial portion of the urban population resides, should be prioritised as part of continued efforts to meet the Sustainable Development Goal national target of less than 25 deaths per 1000 live births
Particle emission characteristics of a gas turbine with a double annular combustor
The total climate, air quality and health impact of aircraft black carbon (BC) emissions depends on quantity (mass and number concentration), as well as morphology (fractal dimension and surface area) of emitted BC aggregates. This study examines multiple BC emission metrics from a gas turbine with a double annular combustor, CFM56-5B4-2P. As a part of the SAMPLE III.2 campaign, concurrent measurements of particle mobility, particle mass, particle number concentration and mass concentration, as well as collection of transmission electron microscopy (TEM) samples, allowed for characterization of the BC emissions. Mass- and number-based emission indices were strongly influenced by thrust setting during pilot combustion and ranged from <1 to 208 mg/kg-fuel and 3Ă1012 to 3Ă1016 particles/kg-fuel, respectively. Mobility measurements indicated that mean diameters ranged from 7-44 nm with a strong dependence on thrust during pilot-only combustion. Using aggregation and sintering theory with empirical effective density relationships, a power law relationship between primary particle diameter and mobility diameter is presented. Mean primary particle diameter ranged from 6-19 nm, however, laser induced incandescence (LII) and mass-mobility calculated primary particle diameters demonstrated opposite trends with thrust setting. Similarly, mass-mobility-calculated aggregate mass specific surface area and LII-measured surface area were not in agreement, indicating both methods need further development and validation before use as quantitative indicators of primary particle diameter and mass-specific surface area.The authors express their gratitude to a number of people and organizations in helping to plan, conduct, finance and provide instruments for this measurement campaign. The 537 European Aviation Safety Agency (EASA) funded the SAMPLE III SC02 campaign (EASA.2010.FC.10, Specific Contract No: SC02). The Federal Office of Civil Aviation, Switzerland (FOCA) was critical in for providing additional financial support and arranging facilities which made this study possible. We also thank the SR Technics test bed staff, including Frithjof Siegerist, for operating the engines and enabling access to the test facility. We thank AVL, Cambustion, Grimm & TSI supplying both instruments and expertise.This is the author accepted manuscript. The final version is available from Taylor & Francis via http://dx.doi.org/10.1080/02786826.2015.107845
Secondary bacterial infections of buruli ulcer lesions before and after chemotherapy with streptomycin and rifampicin
Buruli ulcer (BU), caused by Mycobacterium ulcerans is a chronic necrotizing skin disease. It usually starts with a subcutaneous nodule or plaque containing large clusters of extracellular acid-fast bacilli. Surrounding tissue is destroyed by the cytotoxic macrolide toxin mycolactone produced by microcolonies of M. ulcerans. Skin covering the destroyed subcutaneous fat and soft tissue may eventually break down leading to the formation of large ulcers that progress, if untreated, over months and years. Here we have analyzed the bacterial flora of BU lesions of three different groups of patients before, during and after daily treatment with streptomycin and rifampicin for eight weeks (SR8) and determined drug resistance of the bacteria isolated from the lesions. Before SR8 treatment, more than 60% of the examined BU lesions were infected with other bacteria, with Staphylococcus aureus and Pseudomonas aeruginosa being the most prominent ones. During treatment, 65% of all lesions were still infected, mainly with P. aeruginosa. After completion of SR8 treatment, still more than 75% of lesions clinically suspected to be infected were microbiologically confirmed as infected, mainly with P. aeruginosa or Proteus miriabilis. Drug susceptibility tests revealed especially for S. aureus a high frequency of resistance to the first line drugs used in Ghana. Our results show that secondary infection of BU lesions is common. This could lead to delayed healing and should therefore be further investigated
Phylogeography and demographic history of Epomophorus gambianus: contrasting nuclear and mitochondrial DNA
The Gambian epauletted fruit bat (Epomophorus gambianus) is an abundant species that roosts in both urban and rural settings. The possible role of E. gambianus as a reservoir host of zoonotic diseases underlines the need to better understand the species movement patterns. So far, neither observational nor phylogenetic studies have identified the dispersal range or behavior of this species. Comparative analyses of mitochondrial and nuclear markers from 20 localities across the known distribution of E. gambianus showed population panmixia, except for the populations in Ethiopia and southern Ghana (Accra and VeâGolokwati). The Ethiopian population may be ancestral and is highly divergent to the species across the rest of its range, possibly reflecting isolation of an ancient colonization along an eastâwest axis. Mitochondrial haplotypes in the Accra population display a strong signature of a past bottleneck event; evidence of either an ancient or recent bottleneck using microsatellite data, however, was not detected. Demographic analyses identified population expansion in most of the colonies, except in the female line of descent in the Accra population. The molecular analyses of the colonies from Ethiopia and southern Ghana show gender dispersal bias, with the mitochondrial DNA fixation values over ten times those of the nuclear markers. These findings indicate free mixing of the species across great distances, which should inform future epidemiological studies
The Gambian Epauletted Fruit Bat Shows Increased Genetic Divergence in the Ethiopian Highlands and in an Area of Rapid Urbanisation
The Gambian epauletted fruit bat (Epomophorus gambianus) is an abundant species that roosts in both urban and rural settings. The possible role of E. gambianus as a reservoir host of zoonotic diseases underlines the need to better understand the species movement patterns. So far, neither observational nor phylogenetic studies have identified the dispersal range or behavior of this species. Comparative analyses of mitochondrial and nuclear markers from 20 localities across the known distribution of E. gambianus showed population panmixia, except for the populations in Ethiopia and southern Ghana (Accra and VeâGolokwati). The Ethiopian population may be ancestral and is highly divergent to the species across the rest of its range, possibly reflecting isolation of an ancient colonization along an eastâwest axis. Mitochondrial haplotypes in the Accra population display a strong signature of a past bottleneck event; evidence of either an ancient or recent bottleneck using microsatellite data, however, was not detected. Demographic analyses identified population expansion in most of the colonies, except in the female line of descent in the Accra population. The molecular analyses of the colonies from Ethiopia and southern Ghana show gender dispersal bias, with the mitochondrial DNA fixation values over ten times those of the nuclear markers. These findings indicate free mixing of the species across great distances, which should inform future epidemiological studies
COVID-19 outbreaks following full reopening of primary and secondary schools in England: Cross-sectional national surveillance, November 2020.
Background: The full reopening of schools in September 2020 was associated with an increase in COVID-19 cases and outbreaks in educational settings across England. Methods: Primary and secondary schools reporting an outbreak (âĽ2 laboratory-confirmed cases within 14 days) to Public Health England (PHE) between 31 August and 18 October 2020 were contacted in November 2020 to complete an online questionnaire. Interpretation: There were 969 school outbreaks reported to PHE, comprising 2% (n = 450) of primary schools and 10% (n = 519) of secondary schools in England. Of the 369 geographically-representative schools contacted, 179 completed the questionnaire (100 primary schools, 79 secondary schools) and 2,314 cases were reported. Outbreaks were larger and across more year groups in secondary schools than in primary schools. Teaching staff were more likely to be the index case in primary (48/100, 48%) than secondary (25/79, 32%) school outbreaks (P = 0.027). When an outbreak occurred, attack rates were higher in staff (881/17,362; 5.07; 95%CI, 4.75-5.41) than students, especially primary school teaching staff (378/3852; 9.81%; 95%CI, 8.90-10.82%) compared to secondary school teaching staff (284/7146; 3.97%; 95%CI, 3.79-5.69%). Secondary school students (1105/91,919; 1.20%; 95%CI, 1.13-1.28%) had higher attack rates than primary school students (328/39,027; 0.84%; 95%CI, 0.75-0.94%). Conclusions: A higher proportion of secondary schools than primary schools reported a COVID-19 outbreak and experienced larger outbreaks across multiple school year groups. The higher attack rate among teaching staff during an outbreak, especially in primary schools, suggests that additional protective measures may be needed. Funding: PHE
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