3,377 research outputs found

    Biodesalination: an emerging technology for targeted removal of Na+and Cl−from seawater by cyanobacteria

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    Although desalination by membrane processes is a possible solution to the problem of freshwater supply, related cost and energy demands prohibit its use on a global scale. Hence, there is an emerging necessity for alternative, energy and cost-efficient methods for water desalination. Cyanobacteria are oxygen-producing, photosynthetic bacteria that actively grow in vast blooms both in fresh and seawater bodies. Moreover, cyanobacteria can grow with minimal nutrient requirements and under natural sunlight. Taking these observations together, a consortium of five British Universities was formed to test the principle of using cyanobacteria as ion exchangers, for the specific removal of Na+ and Cl− from seawater. This project consisted of the isolation and characterisation of candidate strains, with central focus on their potential to be osmotically and ionically adaptable. The selection panel resulted in the identification of two Euryhaline strains, one of freshwater (Synechocystis sp. Strain PCC 6803) and one of marine origin (Synechococcus sp. Strain PCC 7002) (Robert Gordon University, Aberdeen). Other work packages were as follows. Genetic manipulations potentially allowed for the expression of a light-driven, Cl−-selective pump in both strains, therefore, enhancing the bioaccumulation of specific ions within the cell (University of Glasgow). Characterisation of surface properties under different salinities (University of Sheffield), ensured that cell–liquid separation efficiency would be maximised post-treatment, as well as monitoring the secretion of mucopolysaccharides in the medium during cell growth. Work at Newcastle University is focused on the social acceptance of this scenario, together with an assessment of the potential risks through the generation and application of a Hazard Analysis and Critical Control Points plan. Finally, researchers in Imperial College (London) designed the process, from biomass production to water treatment and generation of a model photobioreactor. This multimodal approach has produced promising first results, and further optimisation is expected to result in mass scaling of this process

    Sex and Gender in Medical Education, and proceedings from the 2015 Sex and Gender Education Summit

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    The Sex and Gender Medical Education Summit: a roadmap for curricular innovation was a collaborative initiative of the American Medical Women\u27s Association, Laura W. Bush Institute for Women’s Health, Mayo Clinic, and Society for Women\u27s Health Research (www.sgbmeducationsummit.com). It was held on October 18–19, 2015 to provide a unique venue for collaboration among nationally and internationally renowned experts in developing a roadmap for the incorporation of sex and gender based concepts into medical education curricula. The Summit engaged 148 in-person attendees for the 1 1/2-day program. Pre- and post-Summit surveys assessed the impact of the Summit, and workshop discussions provided a framework for informal consensus building. Sixty-one percent of attendees indicated that the Summit had increased their awareness of the importance of sex and gender specific medicine. Other comments indicate that the Summit had a significant impact for motivating a call to action among attendees and provided resources to initiate change in curricula within their home institutions. These educational efforts will help to ensure a sex and gender basis for delivery of health care in the future

    Comment on "X-ray resonant scattering studies of orbital and charge ordering in Pr1-xCaxMnO3"

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    In a recent published paper [Phys. Rev. B 64, 195133 (2001)], Zimmermann et al. present a systematic x-ray scattering study of charge and orbital ordering phenomena in the Pr1-xCaxMnO3 series with x= 0.25, 0.4 and 0.5. They propose that for Ca concentrations x=0.4 and 0.5, the appearance of (0, k+1/2, 0) reflections are originated by the orbital ordering of the eg electrons in the a-b plane while the (0, 2k+1, 0) reflections are due to the charge ordering among the Mn3+ and Mn4+ ions. Moreover, for small Ca concentrations (x<0.3), the orbital ordering is only considered and it occurs at (0, k, 0) reflections. A rigorous analysis of all these resonance reflections will show the inadequacy of the charge-orbital model proposed to explain the experimental results. In addition, this charge-orbital model is highly inconsistent with the electronic balance. On the contrary, these reflections can be easily understood as arising from the anisotropy of charge distribution induced by the presence of local distortions, i.e. due to a structural phase transition.Comment: 10 pages, 2 figures.To be published Phys. Rev.

    Bereavement through substance use: findings from an interview study with adults in England and Scotland

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    Background Deaths associated with alcohol and/or drugs belong to a category of ‘special’ deaths due to three characteristics: traumatic circumstances of the death, stigma directed to both the bereaved and the deceased, and resulting disenfranchised grief experienced by the bereaved. These factors can impede those who are bereaved in this way from both grieving and accessing support. In response to a lack of research in this area this paper reports on an interview study that has aimed to better understand the experiences and needs of this neglected group of bereaved people. Method Interviews with 106 adults (parents, children, spouses, siblings, nieces and friends) bereaved through substance use in Scotland and England. Results Five themes describe interviewee experiences: possibility of death, official processes, stigma, grief and support. These findings suggest what is dominant or unique in this group of bereaved people; namely, that living with substance use (including anticipatory grief), experiencing the subsequent death (often traumatic and stigmatised) and the responses of professionals and others (more likely negative than positive) can disenfranchise grief and negatively impact bereavement and seeking support. Conclusions This article describes a large and unique sample, the largest in the world to be recruited from this population. Our study raises awareness of a hitherto largely ignored and marginalised group of bereaved people, highlighting what might be particular to their bereavement experience and how this may differ from other bereavements, thereby providing an evidence base for improving the availability, level and quality of support. © 2016 Taylor & Franci

    A New Atomic Force Microscopy Technique for the Measurement of the Elastic Properties of Biological Materials

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    We developed a new technique to measure elastic properties by using the atomic force microscope (AFM) tip to press samples into grooves etched in a GaAs substrate. We measured the Young\u27s modulus of ÎČ-chitin fibres with cross-sections less than 40 nm X 20 nm to be 1-2 X 1011 N/m2. In the isotropic approximation, the Young\u27s modulus of the S-layer sheath of the archaeobacterium Methanospirillum hungatei was 1-3 X 1010 N/m2. By testing the sheath to breaking strength we estimated the bacterium can sustain an internal pressure as high as 100-200 atmospheres (1-2 x 107 N/m2)
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