478 research outputs found

    Magneto-orbital helices and multiferroicity

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    Orbitally ordered states evolving coincidentally with structural distortions and magnetic ordering provide a novel route to controlling electronic and magnetic properties of materials through external fields. We report an unprecedented magneto-orbital helix in CaMn7O12, found to give rise to the largest magnetically induced ferroelectric polarisation measured to date. Characterisation of the structural modulation using x-ray diffraction, and analysis of magnetic exchange shows that orbital order is crucial in stabilising a chiral magnetic structure, thus allowing for electric polarisation. Additionally, the presence of a global structural rotation enables the coupling between this polarisation and magnetic helicity required for multiferrocitiy. These novel principles open up the possibility of discovering new high-temperature multiferroics.Comment: Submitted to Nature Communication

    High-frequency monitoring of nitrogen and phosphorus response in three rural catchments to the end of the 2011–2012 drought in England

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    This paper uses high-frequency bankside measurements from three catchments selected as part of the UK government-funded Demonstration Test Catchments (DTC) project. We compare the hydrological and hydrochemical patterns during the water year 2011–2012 from the Wylye tributary of the River Avon with mixed land use, the Blackwater tributary of the River Wensum with arable land use and the Newby Beck tributary of the River Eden with grassland land use. The beginning of the hydrological year was unusually dry and all three catchments were in states of drought. A sudden change to a wet summer occurred in April 2012 when a heavy rainfall event affected all three catchments. The year-long time series and the individual storm responses captured by in situ nutrient measurements of nitrate and phosphorus (total phosphorus and total reactive phosphorus) concentrations at each site reveal different pollutant sources and pathways operating in each catchment. Large storm-induced nutrient transfers of nitrogen and or phosphorus to each stream were recorded at all three sites during the late April rainfall event. Hysteresis loops suggested transport-limited delivery of nitrate in the Blackwater and of total phosphorus in the Wylye and Newby Beck, which was thought to be exacerbated by the dry antecedent conditions prior to the storm. The high rate of nutrient transport in each system highlights the scale of the challenges faced by environmental managers when designing mitigation measures to reduce the flux of nutrients to rivers from diffuse agricultural sources. It also highlights the scale of the challenge in adapting to future extreme weather events under a changing climate

    1881 Proceedings of the Ecumenical Methodist Conference

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    https://place.asburyseminary.edu/wmcproceedings/1007/thumbnail.jp

    Glioma stem-like cells and metabolism:Potential for novel therapeutic strategies

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    Glioma stem-like cells (GSCs) were first described as a population which may in part be resistant to traditional chemotherapeutic therapies and responsible for tumour regrowth. Knowledge of the underlying metabolic complexity governing GSC growth and function may point to potential differences between GSCs and the tumour bulk which could be harnessed clinically. There is an increasing interest in the direct/indirect targeting or reprogramming of GSC metabolism as a potential novel therapeutic approach in the adjuvant or recurrent setting to help overcome resistance which may be mediated by GSCs. In this review we will discuss stem-like models, interaction between metabolism and GSCs, and potential current and future strategies for overcoming GSC resistance

    Effect of an extreme flood event on solute transport and resilience of a mine water treatment system in a mineralised catchment

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    Extreme rainfall events are predicted to become more frequent with climate change and can have a major bearing on instream solute and pollutant transport in mineralised catchments. The Coledale Beck catchment in north-west England was subject to an extreme rainfall event in December 2015 that equated to a 1 in 200-year event. The catchment contains the UK's first passive metal mine water treatment system, and as such had been subject to intense monitoring of solute dynamics before and after commissioning. Due to this monitoring record, the site provides a unique opportunity to assess the effects of a major storm event on (1) catchment-scale solute transport, and (2) the resilience of the new and novel passive treatment system to extreme events. Monitoring suggests a modest decline in treatment efficiency over time that is not synchronous with the storm event and explained instead by changes in system hydraulic efficiency. There was no apparent flushing of the mine system during the event that could potentially have compromised treatment system performance. Analysis of metal transport in the catchment downstream of the mine suggests relatively subtle changes in instream chemistry with modest but statistically-significant reductions in zinc in the lower catchment irrespective of flow condition after the extreme event, but most parameters of interest show no significant change. Increased export of colloidal iron and aluminium is associated with major landslips in the mid-catchment after the storm and provide fresh sorption sites to attenuate dissolved zinc more rapidly in these locations, corroborated by laboratory experiments utilising site materials to investigate the attenuation/release of metals from stream and terrestrial sediments. The data are important as they show both the resilience of passive mine water treatment systems to extreme events and the importance of catchment-scale monitoring to ensure continued effectiveness of treatment initiatives after major perturbation

    Identification of floodwater source areas in Nepal using SCIMAP‐Flood

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    Practical approaches for managing flooding from fluvial sources are moving away from mitigation solely at the point of impact and towards integrated catchment management. This considers the source areas, flow pathways of floodwaters and the locations and exposure to the risk of communities. For a field site in southern Nepal, we analyse catchment response to a range of simulated rainfall events, which when evaluated collectively can help guide potential flood management solutions. This is achieved through the adoption of SCIMAP-Flood, a decision support framework that works at the catchment-scale to identify critical source areas for floodwaters. The SCIMAP-Flood Fitted inverse modelling approach has been applied to the East Rapti catchment, Nepal. For multiple flood impact locations throughout the catchment, SCIMAP-Flood effectively identifies locations where flood management measures would have the most positive effects on risk reduction. The results show that the spatial targeting of mitigation measures in areas of irrigated and rainfed agriculture and the prevention of deforestation or removal of shrubland would be the most effective approaches. If these actions were in the upper catchment above Hetauda or upstream of Manahari they would have the most effective reduction in the flood peak

    Insulin-like growth factor-binding protein-2 promotes prostate cancer cell growth via IGF-dependent or -independent mechanisms and reduces the efficacy of docetaxel

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    Background: The development of androgen independence, chemo-, and radioresistance are critical markers of prostate cancer progression and the predominant reasons for its high mortality. Understanding the resistance to therapy could aid the development of more effective treatments. Aim: The aim of this study is to investigate the effects of insulin-like growth factor-binding protein-2 (IGFBP-2) on prostate cancer cell proliferation and its effects on the response to docetaxel. Methods: DU145 and PC3 cells were treated with IGFBP-2, insulin-like growth factor I (IGF-I) alone or in combination with blockade of the IGF-I receptor or integrin receptors. Cells were also treated with IGFBP-2 short interfering ribonucleic acid with or without a PTEN (phosphatase and tensin homologue deleted on chromosome 10) inhibitor or docetaxel. Tritiated thymidine incorporation was used to measure cell proliferation and Trypan blue cell counting for cell death. Levels of IGFBP-2 mRNA were measured using RT-PCR. Abundance and phosphorylation of proteins were assessed using western immunoblotting. Results: The IGFBP-2 promoted cell growth in both cell lines but with PC3 cells this was in an IGF-dependent manner, whereas with DU145 cells the effect was independent of IGF receptor activation. This IGF-independent effect of IGFBP-2 was mediated by interaction with ÎČ-1-containing integrins and a consequent increase in PTEN phosphorylation. We also determined that silencing IGFBP-2 in both cell lines increased the sensitivity of the cells to docetaxel. Conclusion: The IGFBP-2 has a key role in the growth of prostate cancer cells, and silencing IGFBP-2 expression reduced the resistance of these cells to docetaxel. Targeting IGFBP-2 may increase the efficacy of docetaxel.7 page(s

    The development of accounting in UK universities:an oral history

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    This article reports on the development of the accounting discipline in universities in England and Scotland from the 1960s. Drawing on the oral history narratives of six distinguished accounting scholars who played a significant role in the discipline, this article documents (1) the initial influences on the teaching of accounting in English universities, (2) the different influences on the teaching of accounting in Scottish universities and (3) the influence of US universities and their scholars on the development of academic accounting in the United Kingdom. With a focus on the second wave of accounting professoriate who followed the London School of Economics (LSE) ‘Triumvirate’ of William Baxter, Harold Edey and David Solomons, this article provides first-hand insights into the shape and spread of university accounting education at a crucial stage of its development. This, in turn, develops an understanding of the contemporary academic accounting discipline in the United Kingdom.PostprintPeer reviewe
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