Engaging youth in post-disaster research: Lessons learned from a creative methods approach

Children and youth often demonstrate resilience and capacity in the face of disasters. Yet, they are typically not given the opportunities to engage in youth-driven research and lack access to official channels through which to contribute their perspectives to policy and practice during the recovery process. To begin to fill this void in research and action, this multi-site research project engaged youth from disaster-affected communities in Canada and the United States. This article presents a flexible youth-centric workshop methodology that uses participatory and arts-based methods to elicit and explore youth’s disaster and recovery experiences. The opportunities and challenges associated with initiating and maintaining partnerships, reciprocity and youth-adult power differentials using arts-based methods, and sustaining engagement in post-disaster settings, are discussed. Ultimately, this work contributes to further understanding of the methods being used to conduct research for, with, and about youth.Keywords: youth, disaster recovery, engagement, resilience, arts-based methods, participatory researc

Preclinical evaluation of lime juice as a topical microbicide candidate

Background: The continued growth of the global HIV epidemic highlights the urgent need to develop novel prevention strategies to reduce HIV transmission. The development of topical microbicides is likely to take a number of years before such a product would be widely available. This has resulted in a call for the rapid introduction of simpler vaginal intervention strategies in the interim period. One suggested practice would be vaginal douching with natural products including lime or lemon juice. Here we present a comprehensive preclinical evaluation of lime juice (LiJ) as a potential intervention strategy against HIV. Results: Pre-treatment of HIV with LiJ demonstrated direct virucidal activity, with 10% juice inactivating the virus within 5 minutes. However, this activity was significantly reduced in the presence of seminal plasma, where inactivation required maintaining a 1:1 mixture of neat LiJ and seminal plasma for more than 5 minutes. Additionally, LiJ demonstrated both time and dosedependent toxicity towards cervicovaginal epithelium, where exposure to 50% juice caused 75–90% toxicity within 5 minutes increasing to 95% by 30 minutes. Cervicovaginal epithelial cell monolayers were more susceptible to the effects of LiJ with 8.8% juice causing 50% toxicity after 5 minutes. Reconstructed stratified cervicovaginal epithelium appeared more resilient to LiJ toxicity with 30 minutes exposure to 50% LiJ having little effect on viability. However viability was reduced by 75% and 90% following 60 and 120 minutes exposure. Furthermore, repeat application (several times daily) of 25% LiJ caused 80–90% reduction in viability. Conclusion: These data demonstrate that the virucidal activity of LiJ is severely compromised in the presence of seminal plasma. Potentially, to be effective against HIV in vivo, women would need to apply a volume of neat LiJ equal to that of an ejaculate, and maintain this ratio vaginally for 5–30 minutes after ejaculation. Data presented here suggest that this would have significant adverse effects on the genital mucosa. These data raise serious questions about the plausibility and safety of such a prevention approach

Pore structural evolution of shale following thermochemical treatment

Shales experience heat treatment concurrent with the presence of water or steam during reservoir engineering interventions, such as high pressure water fracking and in-situ combustion of hydrocarbons. This work utilises a novel technique, which is a combination of gas sorption overcondensation and integrated mercury porosimetry experiments, not used before for any type of porous material, to study the pore structure of a shale rock, and its evolution following thermal treatment in the presence of water. Overcondensation allows the extension of gas sorption beyond the limits of conventional experiments to enable direct study of macroporosity. Scanning curve experiments, initiated from the complete boundary desorption isotherm, that can only be obtained for macropores by overcondensation experiments, has revealed details of the relative pore size spatial disposition within the network. In particular, it has been found that the new large voids formed by treatment are shielded by relatively much narrower pore windows. Use of a range of different adsorbates, with differing polarity, has allowed the chemical nature of the pore surface before and after treatment to be probed. Integrated rate of gas sorption and mercury porosimetry experiments have determined the level of the particular contribution to mass transport rates of the newly introduced porosity generated by thermal treatment. Combined CXT and mercury porosimetry have allowed the mapping of the macroscopic spatial distribution of even the new mesoporosity, and revealed the degree of pervasiveness of the new voids that leads to a thousand-fold increase in mass transport on thermal treatment

Determination of pore network accessibility in hierarchical porous solids

This paper validates the hypothesis that the supposedly non-specific adsorbates nitrogen and argon wet heavy metals differently, and shows how this unexpected effect can be actively utilised to deliver information on pore inter-connectivity. To explore surface chemistry influences on differential adsorbate wetting, new findings for a mixed silica-alumina material were compared with data for pure silica and alumina materials. The new structural characterisation described can determine the distribution of the particular sub-set of meso-and micro-pores that connect directly to macropores that entrap mercury following porosimetry, as mapped by computerised X-ray tomography. Hence, it elucidates the spatial organization of the network and measures the improved accessibility to smaller pores provided by larger pores. It was shown that the silica-alumina pellets have a hierarchical pore-size arrangement, similar to the optimal blood vessel network architecture in animals. The network architecture derived from the new method has been independently validated using complementary gas sorption scanning curves, integrated mercury porosimetry, and NMR cryoporometry. It has also been shown that, rather than hindering interpretation of characterisation data, emergent effects for networks associated with these techniques can be marshalled to enable detailed assessment of the pore structures of complex, disordered solids

Structural and chemical heterogeneity in ancient glass probed using gas overcondensation, X-ray tomography, and solid-state NMR

Rare ancient glasses have complex, multi-scale structures requiring more sophisticated and non-destructive pore characterisation techniques than usual. Homotattic patch models for nitrogen adsorption gave better fits to the isotherm data, more accurate void space descriptors, and also greater understanding of the underlying physical factors affecting adsorption, than standard BET. These homotattic patch models revealed the critical role of iron impurities in determining adsorption behaviour. Non-destructive sodium-23 NMR relaxometry validated the homotattic patch model for some natron glasses, and, in turn, was validated using multiple quantum magic-angle spinning (MQMAS) 23Na NMR. X-ray tomography images of the glasses showed the presence of large macroporous bubbles, while FEG-SEM revealed nanopores within the glass matrix. A newly-developed, gas overcondensation technique, suitable for small amounts of low porosity material, assessed the inter-relationship between the disparate levels in this hierarchical porosity. This technique demonstrated that the nanoporosity did not form a ‘corona’ around the bubbles, due to leaching from the glass, as initially supposed from tomography data, but was completely disconnected, and, thus, is probably associated with glass alkalinity. Gas overcondensation is demonstrated as a non-destructive alternative to mercury porosimetry for probing multi-scale porosity in rare artefacts

Evolution of the mineralogy, pore structure and transport properties of Nordland Shale following exposure to supercritical carbon dioxide

The Nordland shale forms the caprock of the Utsira sands of the Sleipner reservoir currently used for carbon dioxide sequestration. The long-term exposure of shale rocks to supercritical carbon dioxide (scCO2), or scCO2-brine mixtures, may lead to structural and chemical changes in shale that lead to increases in permeability of inter-layers and caprocks, that may mean changes to plume migration behaviour and/or loss of seal efficiency of caprocks. A detailed study has been made of the initial pore structure of Nordland shale and the changes following accelerated treatment with scCO2. Gas sorption scanning curves have suggested that the void space of the original shale consisted of a Network (denoted 1) of micropores and smaller mesopores that is thermodynamically independent of a Network (2) of larger mesopores and macropores. This work introduces a new iodononane pre-adsorption technique to map the macroscopic (>microns) spatial distribution of micropores (<2 nm) and smaller mesopores in shales using CXT. CXT imaging of shale samples with iodononane pre-adsorbed in Network 1, or with entrapped mercury confined to only Network 2, suggested that both small- and large-sized pore networks were pervasive through the shale and associated with the continuous illite matrix phase. The feldspar and quartz grains did not form part of either network, though inter-particle macropores were found surrounding these mineral grains from CXT imaging of mercury entrapped there. Kinetic gas uptake experiments conducted on samples before and after filling Network 1 with iodononane suggested that the smaller mesopores were, despite their small size and thermodynamic independence from the macropores, still critical to mass transport, with the diffusion flux being funnelled through them. Shale surface areas obtained using the homotattic patch adsorption model were found more physically realistic than those determined via the ISO BET method since multi-linear regression of only the logarithm of the former, together with that of the Network 1 pore volume, predicted the gas-phase mass transport coefficient following treatment. This work demonstrated the need for the novel characterisation methods and data analysis presented here to properly understand the structure-transport relationship in shales exposed to scCO2

Determination of pore network accessibility in hierarchical porous solids

This paper validates the hypothesis that the supposedly non-specific adsorbates nitrogen and argon wet heavy metals differently, and shows how this unexpected effect can be actively utilised to deliver information on pore inter-connectivity. To explore surface chemistry influences on differential adsorbate wetting, new findings for a mixed silica-alumina material were compared with data for pure silica and alumina materials. The new structural characterisation described can determine the distribution of the particular sub-set of meso-and micro-pores that connect directly to macropores that entrap mercury following porosimetry, as mapped by computerised X-ray tomography. Hence, it elucidates the spatial organization of the network and measures the improved accessibility to smaller pores provided by larger pores. It was shown that the silica-alumina pellets have a hierarchical pore-size arrangement, similar to the optimal blood vessel network architecture in animals. The network architecture derived from the new method has been independently validated using complementary gas sorption scanning curves, integrated mercury porosimetry, and NMR cryoporometry. It has also been shown that, rather than hindering interpretation of characterisation data, emergent effects for networks associated with these techniques can be marshalled to enable detailed assessment of the pore structures of complex, disordered solids

Techniques for direct experimental evaluation of structure-transport relationships in disordered porous solids

Determining structure-transport relationships is critical to optimising the activity and selectivity performance of porous pellets acting as heterogeneous catalysts for diffusion-limited reactions. For amorphous porous systems determining the impact of particular aspects of the void space on mass transport often requires complex characterization and modelling steps to deconvolve the specific influence of the feature in question. These characterization and modelling steps often have limited accuracy and precision. It is the purpose of this work to present a case-study demonstrating the use of a more direct experimental evaluation of the impact of pore network features on mass transport. The case study evaluated the efficacy of the macropores of a bidisperse porous foam structure on improving mass transport over a purely mesoporous system. The method presented involved extending the novel integrated gas sorption and mercury porosimetry method to include uptake kinetics. Results for the new method were compared with those obtained by the alternative NMR cryodiffusometry technique, and found to lead to similar conclusions. It was found that the experimentally-determined degree of influence of the foam macropores was in line with expectations from a simple resistance model for a disconnected macropore network