Evaluation of an Integrated Approach Involving Chemical and Biological Processes for the Detoxification of Gold Tailings Effluent in Ghana

Chemical and bio-remediation measures for the detoxification of pollutants such as cyanide and heavy metals in mine tailings effluent have been developed over the years. The study sought to evaluate the decrease in the concentrations of Cu, Zn, Fe, Cd, As and Pb through the integration of the processes involving photo-oxidation, activated carbon, hydrogen peroxide and bacterial degradation to decontaminate wastewater from the gold ore treatment plant until release into the environment in Ghana. The levels of trace metals Cu (0.345 mg l-1), Zn (0.07 mg l-1) and Fe (0.146 mg l-1) in treated effluent released into natural water bodies after bacterial degradation was generally within international and local standards for effluent discharges. Except for As, the levels of Cd and Pb which are hazardous heavy metals that may pose adverse health and environmental effects were within acceptable limits. The toxicity of these metals were in the increasing order Pb < Cd < As. The anthropogenic source of As in the chemically processed arseno-pyritic rock ores of the study area and the marginal 14–49% efficiency of As of the different detoxification processes could have contributed to the high levels of As in the effluent. If optimal conditions are attained for the decontamination processes used, the multi-remediation approach could be an effective solution for the decontamination of mine tailings effluent

Bio-recovery of N and P from an anaerobic digester effluent: The potential of duckweed (Lemna minor)

The possibility of growing duckweed (Lemna minor) on anaerobic digester effluent and its nitrogen and phosphorus acquisition potential was studied. Duckweed was cultured for 21 days on an anaerobic digester effluent using two methods: static aeration (SAT) and normal batch reactor (NBR) techniques, respectively. The treatments involved pure effluent and 1/10, 1/25 and 1/50 effluent dilutions, respectively. Fifty duckweed fronds were grown in the anaerobic digester effluent for 21 days. At the end of the growth period, phosphate levels, total ammonium nitrogen (TAN) andtotal oxidized nitrogen (TON) contents of the growth media were determined. Total nitrogen concentration and orthophosphate P content in the duckweed were also determined. The results obtained indicated that duckweed was capable of growing on the anaerobic digester effluent provided its TAN content did not exceed 42 mg N l-1. Nitrogenuptake by the duckweed from the effluent ranged between 53 and 115.7 mg l-1 whereas P uptake varied from 1.40 to 8.4 mg P l-1. The relative growth rate of duckweed in the anaerobic digester effluent was observed to be comparable to literature value of 0.22 mg day -1. The results have demonstrated that duckweed has the potential to recover N and P from anaerobic digester effluent

What drives me there? The interplay of socio-psychological gratification and consumer values in social media brand engagement

This is the final version. Available on open access from Elsevier via the DOI in this recordThe social behavioral perspective is under-researched in the extant literature. This hinders the holistic understanding of social media brand engagement. This study examines the interplay of socio-psychological gratification variables (perceived homophily, perceived critical mass, and self-status seeking) and consumer values (personal, interpersonal, and fun) on consumer participation in social media brand engagement. The conceptual model in this study is situated on the principles of Uses and Gratifications, Critical Mass, Homophily, and Values theories. Based on an online survey of 713 Facebook users, a structural equation modeling (with Amos 23.0) disclosed insights on the interplay of motivational factors that underlie social media brand engagement. Our findings suggest that socio-psychological gratification variables (perceived homophily, perceived critical mass, and self-status seeking) drive consumers’ engagement with brand pages and brand communities on social media. This relationship is strengthened by the consumer values. These insights serve as an important basis for researchers and practitioners to understand social media brand engagement and its outcomes

Diabetes and stroke

The association between diabetes and stroke is well established. Recent large‐scale, international population studies suggest that diabetes is one of the most important modifiable risk factors for cerebrovascular disease. Despite this, we still have a relative paucity of evidence around the management of diabetes in stroke. The landscape is evolving and recent studies are helping establish best practice and suggesting new therapeutic opportunities. It is possible to develop a practical and clinical synthesis of the evidence around managing diabetes in adult patients with stroke and cerebrovascular disease, based on large trials, systematic reviews and guidelines, and focusing on the scenarios most often encountered in clinical practice. It is also important to recognise that there are common situations where robust evidence is lacking, but practical guidance for clinicians can be suggested

Metabolomics-Based Discovery of Diagnostic Biomarkers for Onchocerciasis

Onchocerciasis, caused by the filarial parasite Onchocerca volvulus, afflicts millions of people, causing such debilitating symptoms as blindness and acute dermatitis. There are no accurate, sensitive means of diagnosing O. volvulus infection. Clinical diagnostics are desperately needed in order to achieve the goals of controlling and eliminating onchocerciasis and neglected tropical diseases in general. In this study, a metabolomics approach is introduced for the discovery of small molecule biomarkers that can be used to diagnose O. volvulus infection. Blood samples from O. volvulus infected and uninfected individuals from different geographic regions were compared using liquid chromatography separation and mass spectrometry identification. Thousands of chromatographic mass features were statistically compared to discover 14 mass features that were significantly different between infected and uninfected individuals. Multivariate statistical analysis and machine learning algorithms demonstrated how these biomarkers could be used to differentiate between infected and uninfected individuals and indicate that the diagnostic may even be sensitive enough to assess the viability of worms. This study suggests a future potential of these biomarkers for use in a field-based onchocerciasis diagnostic and how such an approach could be expanded for the development of diagnostics for other neglected tropical diseases

Short-Course, High-Dose Rifampicin Achieves Wolbachia Depletion Predictive of Curative Outcomes in Preclinical Models of Lymphatic Filariasis and Onchocerciasis

Lymphatic filariasis (LF) and onchocerciasis are priority neglected tropical diseases targeted for elimination. The only safe drug treatment with substantial curative activity against the filarial nematodes responsible for LF (Brugia malayi, Wuchereria bancrofti) or onchocerciasis (Onchocerca volvulus) is doxycycline. The target of doxycycline is the essential endosymbiont, Wolbachia. Four to six weeks doxycycline therapy achieves >90% depletion of Wolbachia in worm tissues leading to blockade of embryogenesis, adult sterility and premature death 18–24 months post-treatment. Long treatment length and contraindications in children and pregnancy are obstacles to implementing doxycycline as a public health strategy. Here we determine, via preclinical infection models of Brugia malayi or Onchocerca ochengi that elevated exposures of orally-administered rifampicin can lead to Wolbachia depletions from filariae more rapidly than those achieved by doxycycline. Dose escalation of rifampicin achieves >90% Wolbachia depletion in time periods of 7 days in B. malayi and 14 days in O. ochengi. Using pharmacokinetic-pharmacodynamic modelling and mouse-human bridging analysis, we conclude that clinically relevant dose elevations of rifampicin, which have recently been determined as safe in humans, could be administered as short courses to filariasis target populations with potential to reduce anti-Wolbachia curative therapy times to between one and two weeks

A Research Agenda for Helminth Diseases of Humans: Health Research and Capacity Building in Disease-Endemic Countries for Helminthiases Control

Capacity building in health research generally, and helminthiasis research particularly, is pivotal to the implementation of the research and development agenda for the control and elimination of human helminthiases that has been proposed thematically in the preceding reviews of this collection. Since helminth infections affect human populations particularly in marginalised and low-income regions of the world, they belong to the group of poverty-related infectious diseases, and their alleviation through research, policy, and practice is a sine qua non condition for the achievement of the United Nations Millennium Development Goals. Current efforts supporting research capacity building specifically for the control of helminthiases have been devised and funded, almost in their entirety, by international donor agencies, major funding bodies, and academic institutions from the developed world, contributing to the creation of (not always equitable) North–South “partnerships”. There is an urgent need to shift this paradigm in disease-endemic countries (DECs) by refocusing political will, and harnessing unshakeable commitment by the countries' governments, towards health research and capacity building policies to ensure long-term investment in combating and sustaining the control and eventual elimination of infectious diseases of poverty. The Disease Reference Group on Helminth Infections (DRG4), established in 2009 by the Special Programme for Research and Training in Tropical Diseases (TDR), was given the mandate to review helminthiases research and identify research priorities and gaps. This paper discusses the challenges confronting capacity building for parasitic disease research in DECs, describes current capacity building strategies with particular reference to neglected tropical diseases and human helminthiases, and outlines recommendations to redress the balance of alliances and partnerships for health research between the developed countries of the “North” and the developing countries of the “South”. We argue that investing in South–South collaborative research policies and capacity is as important as their North–South counterparts and is essential for scaled-up and improved control of helminthic diseases and ultimately for regional elimination

Autophagy Gene Variant IRGM −261T Contributes to Protection from Tuberculosis Caused by Mycobacterium tuberculosis but Not by M. africanum Strains

The human immunity-related GTPase M (IRGM) has been shown to be critically involved in regulating autophagy as a means of disposing cytosolic cellular structures and of reducing the growth of intracellular pathogens in vitro. This includes Mycobacterium tuberculosis, which is in agreement with findings indicating that M. tuberculosis translocates from the phagolysosome into the cytosol of infected cells, where it becomes exposed to autophagy. To test whether IRGM plays a role in human infection, we studied IRGM gene variants in 2010 patients with pulmonary tuberculosis (TB) and 2346 unaffected controls. Mycobacterial clades were classified by spoligotyping, IS6110 fingerprinting and genotyping of the pks1/15 deletion. The IRGM genotype −261TT was negatively associated with TB caused by M. tuberculosis (OR 0.66, CI 0.52–0.84, Pnominal 0.0009, Pcorrected 0.0045) and not with TB caused by M. africanum or M. bovis (OR 0.95, CI 0.70–1.30. P 0.8). Further stratification for mycobacterial clades revealed that the protective effect applied only to M. tuberculosis strains with a damaged pks1/15 gene which is characteristic for the Euro-American (EUAM) subgroup of M. tuberculosis (OR 0.63, CI 0.49–0.81, Pnominal 0.0004, Pcorrected 0.0019). Our results, including those of luciferase reporter gene assays with the IRGM variants −261C and −261T, suggest a role for IRGM and autophagy in protection of humans against natural infection with M. tuberculosis EUAM clades. Moreover, they support in vitro findings indicating that TB lineages capable of producing a distinct mycobacterial phenolic glycolipid that occurs exclusively in strains with an intact pks1/15 gene inhibit innate immune responses in which IRGM contributes to the control of autophagy. Finally, they raise the possibility that the increased frequency of the IRGM −261TT genotype may have contributed to the establishment of M. africanum as a pathogen in the West African population

Correction: A Seroepidemiological Study of Serogroup A Meningococcal Infection in the African Meningitis Belt.

[This corrects the article DOI: 10.1371/journal.pone.0147928.]

Wolbachia endobacteria depletion by doxycycline as antifilarial therapy has macrofilaricidal activity in onchocerciasis: a randomized placebo-controlled study

In a randomized, placebo-controlled trial in Ghana, 67 onchocerciasis patients received 200-mg/day doxycycline for 4–6 weeks, followed by ivermectin (IVM) after 6 months. After 6–27 months, efficacy was evaluated by onchocercoma histology, PCR and microfilariae determination. Administration of doxycycline resulted in endobacteria depletion and female worm sterilization. The 6-week treatment was macrofilaricidal, with >60% of the female worms found dead, despite the presence of new, Wolbachia-containing worms acquired after the administration of doxycycline. Doxycycline may be developed as second-line drug for onchocerciasis, to be administered in areas without transmission, in foci with IVM resistance and in areas with Loa co-infections