Production of Activated Carbon in a Multi-Functional Platform Pilot Plant

Activated carbons were produced from coconut shells as  raw materials in a Multi-Functional Platform (MFP) pilot plant using the chemical activation method.. Derived activated carbon named, C1, C2, C3, C4, C5, and C6, based on the activation agent used and the heating rate employed, were compared to a commercial activated carbon based on acceptable parameters. C1, C2, C3, C4, C5 and C6 had relative hardness of 95.67%, 92.67%, 89.67, 91.6%, 90.67% and 93.33% respectively, averaging 92.26%, as compared to 95.6% relative hardness for the commercial activated carbon used. C6 the best performing activated carbon produced (using KOH and heating rate of 7.67 ºC/min) , had an adsorption rate of 188.68 mg Au/ h g, which was higher than the adsorption rate of the commercial activated carbon, which is 185.19 mg Au/ h g. This validates the possibility of activated carbon production commercially in Ghana

Economic Impacts of Climate Change on Cereal Production: Implications for Sustainable Agriculture in Northern Ghana

This paper investigates the economic impacts of climate change on cereal crop production in Northern Ghana using 240 households comprising maize and sorghum farmers. The Ricardian regression approach was used to examine the economic impacts of climate change based on data generated from a survey conducted in the 2013/2014 farming seasons. Forty-year time-series data of rainfall and temperature from 1974 to 2013, together with cross-sectional data, were used for the empirical analysis. The Ricardian regression estimates for both maize and sorghum showed varying degrees of climate change impacts on net revenues. The results indicated that early season precipitation was beneficial for sorghum, but harmful for maize. However, mid-season precipitation tended to promote maize production. Temperature levels for all seasons impacted negatively on net revenue for both crops, except during the mid-season, when temperature exerted a positive effect on net revenue for sorghum. Our findings suggest that appropriate adaptation strategies should be promoted to reduce the negative impacts of prevailing climate change on cereal crop production

Chest CT features of patients under investigation for Covid-19 pneumonia in a Ghanaian tertiary hospital: a descriptive study

Background: Coronavirus disease 2019 (COVID-19) has since December 2019 become a problem of global concern. Due to the virus’ novelty and high infectivity, early diagnosis is key to curtailing spread. The knowledge and identification of chest Computerized Tomography (CT) features in Patients Under Investigation (PUI) for the disease would help in its management and containment. Objectives: To describe the chest CT findings of PUI for COVID-19 pneumonia referred to the Department of Radiology of the Korle Bu Teaching Hospital; as well as to determine the relationship between symptom onset and severity of the chest CT findings. Methods: The study was retrospective and included 63 PUI for COVID-19 referred to the Department between 11th April, 2020 and 10th June, 2020, for non-enhanced chest CT imaging. Clinical data were obtained from patients’ records and Reverse Transcriptase–Polymerase Chain Reaction (RT-PCR) results were acquired after the CT evaluation. Results: The mean age in years was 51.1±19.9 SD. More males (52.8%) than females (47.2%) tested positive for COVID-19 and the age range for positive cases was 7 months to 86 years, with a mean of 53.2±21 SD years. Common features of COVID-19 pneumonia were bilateral posterior basal consolidations, Ground Glass Opacities (GGO) and air bronchograms. Findings were worse in patients scanned 5–9 days after onset of symptoms. Conclusion: Adequate knowledge of chest CT features of COVID-19 pneumonia, proves a valuable resource in triaging of symptomatic patients and consequent containment of the disease in the hospital setting

Pneumococcal Antibody Concentrations and Carriage of Pneumococci more than 3 Years after Infant Immunization with a Pneumococcal Conjugate Vaccine

BACKGROUND: A 9-valent pneumococcal conjugate vaccine (PCV-9), given in a 3-dose schedule, protected Gambian children against pneumococcal disease and reduced nasopharyngeal carriage of pneumococci of vaccine serotypes. We have studied the effect of a booster or delayed primary dose of 7-valent conjugate vaccine (PCV-7) on antibody and nasopharyngeal carriage of pneumococci 3-4 years after primary vaccination. METHODOLOGY/PRINCIPAL FINDINGS: We recruited a subsample of children who had received 3 doses of either PCV-9 or placebo (controls) into this follow-up study. Pre- and post- PCV-7 pneumococcal antibody concentrations to the 9 serotypes in PCV-9 and nasopharyngeal carriage of pneumococci were determined before and at intervals up to 18 months post-PCV-7. We enrolled 282 children at a median age of 45 months (range, 38-52 months); 138 had received 3 doses of PCV-9 in infancy and 144 were controls. Before receiving PCV-7, a high proportion of children had antibody concentrations >0.35 µg/mL to most of the serotypes in PCV-9 (average of 75% in the PCV-9 and 66% in the control group respectively). The geometric mean antibody concentrations in the vaccinated group were significantly higher compared to controls for serotypes 6B, 14, and 23F. Antibody concentrations were significantly increased to serotypes in the PCV-7 vaccine both 6-8 weeks and 16-18 months after PCV-7. Antibodies to serotypes 6B, 9V and 23F were higher in the PCV-9 group than in the control group 6-8 weeks after PCV-7, but only the 6B difference was sustained at 16-18 months. There was no significant difference in nasopharyngeal carriage between the two groups. CONCLUSIONS/SIGNIFICANCE: Pneumococcal antibody concentrations in Gambian children were high 34-48 months after a 3-dose primary infant vaccination series of PCV-9 for serotypes other than serotypes 1 and 18C, and were significantly higher than in control children for 3 of the 9 serotypes. Antibody concentrations increased after PCV-7 and remained raised for at least 18 months

Do pneumococcal conjugate vaccines provide any cross-protection against serotype 19A?

<p>Abstract</p> <p>Background</p> <p>Introduction of the 7-valent pneumococcal conjugate vaccine (7vCRM) in several countries has led to a rapid, significant drop in vaccine-type invasive pneumococcal disease (IPD) in immunized children. In the United States and some other countries with high antibiotic use, a subsequent rise in serotype 19A IPD has been taken to indicate that the 19F conjugate in the vaccine provides no cross-protection against the immunologically related 19A.</p> <p>Discussion</p> <p>We systematically assessed the clinical efficacy and effectiveness of 19F-containing vaccines against 19A disease or nasopharyngeal carriage by searching English-language articles in the electronic databases PubMed, Current contents, Scopus, and Embase from 1985 to 2008. The vaccine efficacy and effectiveness point estimates were consistently positive for modest protection against 19A IPD and acute otitis media (AOM). However, statistical significance was not reached in any individual study. No consistent impact of 7vCRM on 19A nasopharyngeal colonization could be detected. These findings are discussed in context of immunogenicity analyses indicating that 7vCRM induces functionally active anti-19A antibodies after the booster dose, and that other 19F-containing vaccine formulations may elicit higher levels of such antibodies after both primary and booster doses.</p> <p>Summary</p> <p>Taken together, these results suggest that 19F-conjugates can provide some protection against 19A disease. The magnitude of this protection in a given setting will likely depend on several factors. These include the anti-19A immunogenicity of the specific vaccine formulation, the number of doses of that formulation needed to elicit the response, and the burden of 19A disease that occurs after those doses. It is possible that a modest protective effect may be obscured by the presence of countervailing selection pressures (such as high antibiotic use) that favor an increase in colonization with antibiotic-non-susceptible strains of 19A.</p

Economic evaluation of pneumococcal conjugate vaccination in The Gambia

<p>Abstract</p> <p>Background</p> <p>Gambia is the second GAVI support-eligible country to introduce the 7-valent pneumococcal conjugate vaccine (PCV7), but a country-specific cost-effectiveness analysis of the vaccine is not available. Our objective was to assess the potential impact of PCVs of different valences in The Gambia.</p> <p>Methods</p> <p>We synthesized the best available epidemiological and cost data using a state-transition model to simulate the natural histories of various pneumococcal diseases. For the base-case, we estimated incremental cost (in 2005 US dollars) per disability-adjusted life year (DALY) averted under routine vaccination using PCV9 compared to no vaccination. We extended the base-case results for PCV9 to estimate the cost-effectiveness of PCV7, PCV10, and PCV13, each compared to no vaccination. To explore parameter uncertainty, we performed both deterministic and probabilistic sensitivity analyses. We also explored the impact of vaccine efficacy waning, herd immunity, and serotype replacement, as a part of the uncertainty analyses, by assuming alternative scenarios and extrapolating empirical results from different settings.</p> <p>Results</p> <p>Assuming 90% coverage, a program using a 9-valent PCV (PCV9) would prevent approximately 630 hospitalizations, 40 deaths, and 1000 DALYs, over the first 5 years of life of a birth cohort. Under base-case assumptions ($3.5 per vaccine), compared to no intervention, a PCV9 vaccination program would cost$670 per DALY averted in The Gambia. The corresponding values for PCV7, PCV10, and PCV13 were $910,$670, and $570 per DALY averted, respectively. Sensitivity analyses that explored the implications of the uncertain key parameters showed that model outcomes were most sensitive to vaccine price per dose, discount rate, case-fatality rate of primary endpoint pneumonia, and vaccine efficacy against primary endpoint pneumonia.</p> <p>Conclusions</p> <p>Based on the information available now, infant PCV vaccination would be expected to reduce pneumococcal diseases caused by <it>S. pneumoniae </it>in The Gambia. Assuming a cost-effectiveness threshold of three times GDP per capita, all PCVs examined would be cost-effective at the tentative Advance Market Commitment (AMC) price of$3.5 per dose. Because the cost-effectiveness of a PCV program could be affected by potential serotype replacement or herd immunity effects that may not be known until after a large scale introduction, type-specific surveillance and iterative evaluation will be critical.</p

Biodegradable Poly(disulfide)s Derived from RAFT Polymerization: Monomer Scope, Glutathione Degradation, and Tunable Thermal Responses

Telechelic, RAFT (reversible addition–fragmentation chain transfer)-derived macromonomers with a pyridyl disulfide end-group were converted into high molecular weight, disulfide-linked polymers using a polycondensation, step-growth procedure. The applicability of the method to polycondense a library of macromonomers with different functionalities including (meth)acrylates and acrylamides was investigated. Side-chain sterics were found to be important as nonlinear poly(ethylene glycol) analogues, which proved incompatible with this synthetic methodology, as were methacrylates due to their pendant methyl group. This method was used to incorporate disulfide bonds into poly(N-isopropylacrylamide), pNIPAM, precursors to give dual-responsive (thermo- and redox) materials. These polymers were shown to selectively degrade in the presence of intracellular concentrations of glutathione but be stable at low concentrations. Due to the molecular weight-dependent cloud point of pNIPAM, the lower critical solution temperature behavior could be switched off by a glutathione gradient without a temperature change: an isothermal transition