THE REMOVAL OF ARSENIC FROM AQUATIC SYSTEMS BY IRON OXYHYDROXIDES

Surveys of dissolved Fe, Mn and As in the River Tamar, Devon, indicated general removal from the water column at low salinities. Manganese and As showed evidence of remobilisation at higher salinities. Total and non-detrital sediment extracts confirmed a remobilisation chemistry for Mn and non-detrital As, and a redox couple between Mn and As was considered. Spatial-temporal analysis of sediment data indicated both physical and chemical processes were involved in the estuarine transport of these elements. Studies of synthetic and natural Fe precipitates indicated that speciation of the Fe source and temperature of formation influenced the surface area and nature of the precipitate formed. The presence of non-authigenic Fe coatings on sedimentary particles was demonstrated. Chemical models of synthetic and natural Fe oxyhydroxides were used to study As adsorption as a function of pH, temperature and precipitate age. Uptake of As (V) onto fresh Fe (III)-derived material was rapid and related to precipitate formation. Adsorption by fresh Fe (II) precipitates was pH dependent in freshwater and in seawater followed two kinetic regimes. Adsorption was 1st order at pH 7.6, where the adsorption process was rate determining. General agreement was found with natural precipitates. The overall adsorption behaviour of aged Fe (II) and Fe (III) precipitates suggested a physical process and an electrostatic adsorption model was proposed. Aged Fe (II) material did not adsorb As (III) and an Fe (III) - As (III) redox model was developed to account for the general slowness of As (III) adsorption. Natural aged precipitates showed complex adsorption behaviour, confirmed by precipitate characterisation studies which indicated a mixed oxide composition. The estuarine behaviour of As was interpreted in terms of the adsorption models and estuarine surveys. A model illustrating the timescales of As adsorption and desorption within an estuary was developed, and used to elucidate the anomalous behaviour of dissolved Fe, Mn and As in the River Carnon, Cornwall.Marine Biological Association, The Laboratory, The Hoe, Plymouth, Devo

Symptoms and severity of visual stress in nursing students: implications for education and healthcare settings

Visual Stress reportedly affects 5-12% of the general population and 20-30% of people with dyslexia. Symptoms are characterized by visual discomfort and perceptual distortions when viewing lines of text, and can be exacerbated by fluorescent lighting and bright paper. In this study, nursing students reported their levels of visual discomfort while reading text on contemporary (ultra-white) paper and on beige-coloured paper, under either standard classroom-lighting (600 lux; n = 31) or reduced illumination(400 lux; n = 25). Under the standard lighting, 10(28%) of subjects reported notable levels of Visual Stress (scoring ≥15 on a visual discomfort scale of 1-30). When reading from the beige-coloured paper the group reported less discomfort across all six symptoms. These differences were statistically significant for five of the six symptoms and the total discomfort score. The results were similar but less pronounced for the group in the reduced illumination condition. This study found that Visual Stress-related reading discomfort can also affect capable readers and, moreover, that simple adjustments to lighting and/or visual media can alleviate such symptoms. The implications of these findings for organisational practice in education and healthcare settings are discussed. El estrés visual puede afectar del 5 al 12% de la población general y del 20 al 30% de las personas con dislexia. Los síntomas se caracterizan por incomodidad visual y distorsiones de la percepción visual en la lectura, y pueden agravarse con la iluminación fluorescente y el papel brillante. En este estudio, estudiantes de enfermería expresan niveles de incomodidad visual al leer texto en papel ultrablanco y en papel de color beige, ya sea con iluminación estándar del aula (600 lux; n = 31) o con iluminación reducida (400 lux ; n = 25). Bajo la iluminación estándar, 10 (28%) de los sujetos informaron niveles notables de estrés visual (puntuación ? 15 en una escala de1 a 30). Al leer en color beige, el grupo presentó menos malestar en los síntomas. Estas diferencias fueron estadísticamente significativas para cinco síntomas y el total de malestar. Los resultados fueron menos pronunciados para el grupo en la condición de iluminación reducida. Encontrándose que la incomodidad de lectura relacionada con estrés visual también puede afectar a lectores expertos y, además, que simples ajustes a la iluminación y/o medios visuales pueden reducirla. Se discuten las implicaciones para la práctica en entornos educativos y sanitarios

Gram scale laboratory synthesis of TC AC 28, a high affinity BET bromodomain ligand

TC AC 28, 6-(1H-Indol-4-yl)-8-methoxy-1-methyl-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepine-4-acetic acid methyl ester, has been synthesized on a near gram scale in seven steps with notable improvements in the reported poor yielding last 2 steps enabling this key chemical probe compound to be available for researchers

On the accretion mode of the intermediate polar V1025 Centauri

The long white-dwarf spin periods in the magnetic cataclysmic variables EX Hya and V1025 Cen imply that if the systems possess accretion discs then they cannot be in equilibrium. It has been suggested that instead they are discless accretors in which the spin-up torques resulting from accretion are balanced by the ejection of part of the accretion flow back towards the secondary. We present phase-resolved spectroscopy of V1025 Cen aimed at deducing the nature of the accretion flow, and compare this with simulations of a discless accretor. We find that both the conventional disc-fed model and the discless-accretor model have strengths and weaknesses, and that further work is needed before we can decide which applies to V1025 Cen.Comment: 9 pages, 8 figures, To appear in MNRAS, includes low-res figures to reduce siz

Soft power, hard news:How journalists at state-funded transnational media legitimize their work

How do journalists working for different state-funded international news organizations legitimize their relationship to the governments which support them? In what circumstances might such journalists resist the diplomatic strategies of their funding states? We address these questions through a comparative study of journalists working for international news organizations funded by the Chinese, US, UK and Qatari governments. Using 52 interviews with journalists covering humanitarian issues, we explain how they minimized tensions between their diplomatic role and dominant norms of journalistic autonomy by drawing on three – broadly shared – legitimizing narratives, involving different kinds of boundary-work. In, the first ‘exclusionary’ narrative, journalists differentiated their ‘truthful’ news reporting from the ‘false’ state ‘propaganda’ of a common Other, the Russian-funded network, RT. In the second ‘fuzzifying’ narrative, journalists deployed the ambiguous notion of ‘soft power’ as an ambivalent ‘boundary concept’, to defuse conflicts between journalistic and diplomatic agendas. In the final ‘inversion’ narrative, journalists argued that, paradoxically, their dependence on funding states gave them greater ‘operational autonomy’. Even when journalists did resist their funding states, this was hidden or partial, and prompted less by journalists’ concerns about the political effects of their work, than by serious threats to their personal cultural capital

Re-conceptualising the link between research and practice in social work: a literature review on knowledge utilisation

Despite the recent movement towards greater research use in many areas of social work, criticisms persist that decision making in practice is seldom informed by sound research evidence. Discourse about the research-to-practice gap in social work has tended to focus on the feasibility of evidence-based practice for the profession, but has rarely drawn from the broader knowledge utilisation literature. There are important understandings to be gained from the knowledge utilisation field, which spans more than six decades of interdisciplinary research.This article introduces the wider knowledge utilisation literature to a social work audience. It considers the potential of this body of literature to facilitate research use in social work, as well as conceptual issues that may be hindering it from informing improvements to research utilisation in practice

Inhibition of αvβ5 Integrin Attenuates Vascular Permeability and Protects against Renal Ischemia-Reperfusion Injury

Ischemia-reperfusion injury (IRI) is a leading cause of AKI. This common clinical complication lacks effective therapies and can lead to the development of CKD. The αvβ5 integrin may have an important role in acute injury, including septic shock and acute lung injury. To examine its function in AKI, we utilized a specific function-blocking antibody to inhibit αvβ5 in a rat model of renal IRI. Pretreatment with this anti-αvβ5 antibody significantly reduced serum creatinine levels, diminished renal damage detected by histopathologic evaluation, and decreased levels of injury biomarkers. Notably, therapeutic treatment with the αvβ5 antibody 8 hours after IRI also provided protection from injury. Global gene expression profiling of post-ischemic kidneys showed that αvβ5 inhibition affected established injury markers and induced pathway alterations previously shown to be protective. Intravital imaging of post-ischemic kidneys revealed reduced vascular leak with αvβ5 antibody treatment. Immunostaining for αvβ5 in the kidney detected evident expression in perivascular cells, with negligible expression in the endothelium. Studies in a three-dimensional microfluidics system identified a pericyte-dependent role for αvβ5 in modulating vascular leak. Additional studies showed αvβ5 functions in the adhesion and migration of kidney pericytes in vitro Initial studies monitoring renal blood flow after IRI did not find significant effects with αvβ5 inhibition; however, future studies should explore the contribution of vasomotor effects. These studies identify a role for αvβ5 in modulating injury-induced renal vascular leak, possibly through effects on pericyte adhesion and migration, and reveal αvβ5 inhibition as a promising therapeutic strategy for AKI