Changes in hydrodynamic, structural and geochemical properties in carbonate rock samples due to reactive transport

Reactive transport plays an important role in the development of a wide range of both anthropic and natural processes affecting geological media. To predict the consequences of reactive transport processes on structural and hydrodynamic properties of a porous media at large time and spatial scales, numerical modeling is a powerful tool. Nevertheless, such models, to be realistic, need geochemical, structural and hydrodynamic data inputs representative of the studied reservoir or material. Here, we present an experimental study coupling traditional laboratory measurements and percolation experiments in order to obtain the parameters that define rock heterogeneity, which can be altered during the percolation of a reactive fluid. In order to validate the experimental methodology and identify the role of the initial heterogeneities on the localization of the reactive transport processes, we used three different limestones with different petrophysical characteristics. We tracked the changes of geochemical, structural and hydrodynamic parameters in these samples induced by the percolation of an acid fluid by measuring, before and after the percolation experiment, petrophysical and hydrodynamic properties of the rocks.Peer ReviewedPostprint (published version

MEETING REPORT: UNESCO-MERCK AFRICA RESEARCH SUMMIT 2015- ACCELERATING ACCESS AND SUSTAINING INNOVATION 'FROM AFRICA FOR AFRICA'.

Background: The Ebola virus disease outbreak of 2014 was the largest, longest and most devastating in the history of the disease. It demonstrated the social and economic impact an emerging infectious disease can have in a globalized world. Health systems in affected countries were stretched to the point of near collapse, while social relations and traditional practices were negatively impacted. Heads of African research institutions, African government representatives, leaders of global pharmaceutical companies, global infectious disease experts and close to 100 young African researchers from 25 countries; Assembled in Geneva on 19 and 20th October 2015, for the inaugural UNESCO-Merck Africa Summit sponsored by the United Nations Educational, Science and Culture Organization and Merck KGA Goal of Summit: The primary goal of the summit was to develop strategies to increase health research capacity in Africa, with special focus on Ebola and enhancing pandemic preparation for emerging infectious diseases. The summit was also provide a forum to showcase the research taking place in Africa, and provided platform for African researchers to network. Some of the key issues discussed included; strategies for enhancing policy frameworks to promote knowledge translation, strengthening of health systems, enhancing knowledge and data sharing, and increasing innovation in Africa. Conclusions: Summit attendees recognized that Africa still bore the heaviest burden of infectious disease, and increased commitment by African governments to fund health research, offered the best hope for developing health solutions and interventions to improve the health of Africans. Improved health in turn would enhance the productivity of Africans, further supporting the socio-economic transformation currently taking place on the contine

Community accountability at peripheral health facilities: a review of the empirical literature and development of a conceptual framework.

Public accountability has re-emerged as a top priority for health systems all over the world, and particularly in developing countries where governments have often failed to provide adequate public sector services for their citizens. One approach to strengthening public accountability is through direct involvement of clients, users or the general public in health delivery, here termed 'community accountability'. The potential benefits of community accountability, both as an end in itself and as a means of improving health services, have led to significant resources being invested by governments and non-governmental organizations. Data are now needed on the implementation and impact of these initiatives on the ground. A search of PubMed using a systematic approach, supplemented by a hand search of key websites, identified 21 papers from low- or middle-income countries describing at least one measure to enhance community accountability that was linked with peripheral facilities. Mechanisms covered included committees and groups (n = 19), public report cards (n = 1) and patients' rights charters (n = 1). In this paper we summarize the data presented in these papers, including impact, and factors influencing impact, and conclude by commenting on the methods used, and the issues they raise. We highlight that the international interest in community accountability mechanisms linked to peripheral facilities has not been matched by empirical data, and present a conceptual framework and a set of ideas that might contribute to future studies

Working with Community Health Workers as 'volunteers' in a vaccine trial: practical and ethical experiences and implications.

Community engagement is increasingly emphasized in biomedical research, as a right in itself, and to strengthen ethical practice. We draw on interviews and observations to consider the practical and ethical implications of involving Community Health Workers (CHWs) as part of a community engagement strategy for a vaccine trial on the Kenyan Coast. CHWs were initially engaged as an important network to be informed about the trial. However over time, and in response to community advice, they became involved in trial information sharing and identifying potential participants; thereby taking on roles that overlapped with those of employed fieldworkers (FWs). While CHWs involvement was generally perceived as positive and appreciated, there were challenges in their relations with FWs and other community members, partly related to levels and forms of remuneration. Specifically, payment of CHWs was not as high as for FWs and was based on 'performance'. This extrinsic motivation had the potential to crowd out CHWs intrinsic motivation to perform their pre-existing community roles. CHWs remuneration potentially also contributed to CHWs distorting trial information to encourage community members to participate; and to researchers encouraging CHWs to utilize their social connections and status to increase the numbers of people who attended information giving sessions. Individual consent processes were protected in this trial through final information sharing and consent being conducted by trained clinical staff who were not embedded in study communities. However, our experiences suggest that roles and remuneration of all front line staff and volunteers involved in trials need careful consideration from the outset, and monitoring and discussion over time

Complex realities: community engagement for a paediatric randomized controlled malaria vaccine trial in Kilifi, Kenya.

BACKGROUND: Community engagement (CE) is increasingly promoted for biomedical research conducted in resource poor settings for both intrinsic and instrumental purposes. Given the potential importance of CE, but also complexities and possibility of unexpected negative outcomes, there is need for more documentation of CE processes in practice. We share experiences of formal CE for a paediatric randomized controlled malaria vaccine trial conducted in three sites within Kilifi County, Kenya. METHODS: Social scientists independent of the trial held in-depth individual interviews with trial researchers (n=5), community leaders (n=8) and parents (15 with enrolled children and 4 without); and group discussions with fieldworkers (n=6) and facility staff (n=2). We conducted a survey of participating households (n=200) and observed over 150 CE activities. RESULTS: The overall CE plan was similar across the three study sites, although less community-based information in site C. Majority perceived CE activities to clear pre-existing concerns and misconceptions; increase visibility, awareness of and trust in trial staff. Challenges included: some community leaders attempting to exert pressure on people to enrol; local wording in information sheets and consent forms feeding into serious anxieties about the trial; and concerns about reduced CE over time. Negative effects of these challenges were mitigated through changes to on-going CE activities, and final information sharing and consent being conducted individually by trained clinical staff. One year after enrolment, 31% (n = 62) of participants' parents reported malaria prevention as the main aim of the activities their children were involved in, and 93% wanted their children to remain involved. CONCLUSION: The trial teams' goals for CE were relatively clear from the outset. Other actors' hopes and expectations (like higher allowances and future employment) were not openly discussed, but emerged over the course of engagements. Encouraging open discussion of all actors' intentions and goals from the outset takes time, risks raising expectations that cannot be met, and is complex. However, doing so in future similar trials may allow successes here to be built upon, and some challenges minimized or avoided. TRIAL REGISTRATION: ClinicalTrials.gov NCT00866619 (registration 19-Mar-2009)

Evidence of anti-chikungunya virus igg and igm antibodies among patients seeking treatment in different health facilities in Kyela District, Tanzania

Chikungunya is an arboviral disease transmitted by aedes mosquitoes, caused by Chikungungunya virus. It consists of an acute illness characterized by fever, rash, and incapacitating arthralgia. This study aimed to estimate the prevalence of Chikungunya fever in patients presenting fever at different health facilities located in Kyela district. Out of 132 recruited patients, 94(71.2 %) were female and 38 (28.8 %) were male. The majority of them 80 (60.6%) were adults (≥25 years). Anti-Chikungunya virus anti-immunoglobulin G (IgG) and anti-immunoglobulin M (IgM) antibodies were detected in serum samples using indirect enzyme-linked immunosorbent assay. Chikungunya virus IgG or IgM antibodies were detected in 19 among 132 serum specimens tested indicating a seroprevalence of 14.3%. Out of 132 sera tested, 14 (11%) had IgG antibodies and 5(3.8%) had IgM antibodies. The higher anti-CHIKV IgG seroprevalence was found in female patients (OR= 3.22; 95% CI: 1.03-10.06) than in male. Similarly patients who took some medication before going to the health centre were found with high CHIKV IgG antibodies (OR= 13.912; 95% CI: 1.76-109.78) as well as in patients who never been vaccinated (OR=4.6; 95%CI: 0.02 – 1.71). Additionally, the uni-variate analysis results revealed, feeling nausea as the symptom of significant association with Chikungunya IgG seropositivity (OR = 4.5; 95% CI: 1.3– 14.4). These findings confirm that CHIKV infection seems to be among the common causes of febrile illness in Kyela district and appears to be actively circulating in the population but is routinely misdiagnosed. This suggests a need to raise awareness among health facilities and policy makers on the use of specific diagnosis for better control of arbovirus diseases in the study region

Complex realities: Community engagement for a paediatric randomized controlled malaria vaccine trial in Kilifi, Kenya

Background: Community engagement (CE) is increasingly promoted for biomedical research conducted in resource poor settings for both intrinsic and instrumental purposes. Given the potential importance of CE, but also complexities and possibility of unexpected negative outcomes, there is need for more documentation of CE processes in practice. We share experiences of formal CE for a paediatric randomized controlled malaria vaccine trial conducted in three sites within Kilifi County, Kenya.Methods: Social scientists independent of the trial held in-depth individual interviews with trial researchers (n = 5), community leaders (n = 8) and parents (15 with enrolled children and 4 without); and group discussions with fieldworkers (n = 6) and facility staff (n = 2). We conducted a survey of participating households (n = 200) and observed over 150 CE activities.Results: The overall CE plan was similar across the three study sites, although less community-based information in site C. Majority perceived CE activities to clear pre-existing concerns and misconceptions; increase visibility, awareness of and trust in trial staff. Challenges included: some community leaders attempting to exert pressure on people to enrol; local wording in information sheets and consent forms feeding into serious anxieties about the trial; and concerns about reduced CE over time. Negative effects of these challenges were mitigated through changes to on-going CE activities, and final information sharing and consent being conducted individually by trained clinical staff. One year after enrolment, 31% (n = 62) of participants' parents reported malaria prevention as the main aim of the activities their children were involved in, and 93% wanted their children to remain involved.Conclusion: The trial teams' goals for CE were relatively clear from the outset. Other actors' hopes and expectations (like higher allowances and future employment) were not openly discussed, but emerged over the course of engagements. Encouraging open discussion of all actors' intentions and goals from the outset takes time, risks raising expectations that cannot be met, and is complex. However, doing so in future similar trials may allow successes here to be built upon, and some challenges minimized or avoided.Trial registration: ClinicalTrials.gov NCT00866619 (registration 19-Mar-2009). © 2014 Angwenyi et al.; licensee BioMed Central Ltd