108 research outputs found

    The glacial geomorphology of upper Godthåbsfjord (Nuup Kangerlua) in south-west Greenland

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    © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of Journal of Maps. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.The Greenland Ice Sheet (GrIS) is known to have experienced widespread retreat over the last century. Information on outlet glacier dynamics, prior to this, are limited due to both a lack of observations and a paucity of mapped or mappable deglacial evidence which restricts our understanding of centennial to millennial timescale dynamics of the GrIS. Here we present glacial geomorphological mapping, for upper Godthåbsfjord, covering 5800 km 2 at a scale of 1:92,000, using a combination of ASTER GDEM V2, a medium-resolution DEM (error < 10 m horizontal and < 6 m vertical accuracy), panchromatic orthophotographs and ground truthing. This work provides a detailed geomorphological assessment for the area, compiled as a single map, comprising of moraines, meltwater channels, streamlined bedrock, sediment lineations, ice-dammed lakes, trimlines, terraces, gullied sediment and marine limits. Whilst some of the landforms have been previously identified, the new information presented here improves our understanding of ice margin behaviour and can be used for future numerical modelling and landform dating programmes. Data also form the basis for palaeoglaciological reconstructions and contribute towards understanding of the centennial to millennial timescale record of this sector of the GrIS.Peer reviewedFinal Published versio

    Terrestrial snail communities of the lower rio grande valley are affected by human disturbance and correlate with vegetation community composition

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    The lower Rio Grande Valley of Texas (LRGV) contains a unique, subtropical, semiarid floodplain with most of the few remaining Tamaulipan thorn forests in the United States. Less than 2% of Tamaulipan thorn forest remains, with urban and agricultural conversion potentially threatening diverse plant and animal communities native to the habitat. We performed vegetative community surveys and conducted a comprehensive survey of terrestrial snail communities in intact (refugia sites, minimally altered in recent times) and altered (previously cleared and regrown or restored) Tamaulipan thorn forest habitats of the LRGV. In a comparison of intact and altered sites that have comparable vegetation (paired sites), we found that intact sites had a less species-rich snail community than their altered counterparts, but this difference was not statistically significant. This counterintuitive result, in part reflects the fact that the most species-rich, intact snail communities (i.e., Sabal Palm Forest) have no altered (restored or regrown) counterparts and so were not included in the paired comparisons. A nestedness analysis supports this, finding that these unique intact sites, which have the highest species richness and no comparable restored sites, contain the largest pool of species in South Texas. Species richness of snails significantly correlated with a precipitation gradient. A general linear model incorporating mean canopy cover, mean plant height, plant abundance, and plant species richness shows a significant correlation with snail communities. This study is the only comprehensive survey of the snail communities of the lower Rio Grande Valley. - La cuenca baja del río Grande en Texas (LRGV) contiene una llanura de inundación única, subtropical y semiárida con la mayor´ıa de los remanentes de los bosques espinosos tamaulipecos en los Estados Unidos. Queda menos del 2% del bosque espinoso tamaulipeco, con la conversión a áreas urbanas y agrıcolas potencialmente amenazando las comunidades diversas de plantas y animales nativos del hábitat. Hicimos muestreos de comunidades vegetales y un muestreo comprensivo de comunidades de caracoles terrestres en hábitats de bosques espinosos tamaulipecos intactos (sitios refugio, con poca alteración en tiempos recientes) y perturbados (previamente cortados y recuperados o restaurados) en el LRGV. En una comparaci ´on de los sitios intactos con los perturbados con la vegetación comparable (sitios emparejados), sitios intactos tuvieron comunidades con menos riqueza de especies de caracoles que sus contrapartes alteradas, aunque la diferencia no fue estad´ısticamente significativa. Este resultado contra intuitivo, en parte refleja el hecho de que las comunidades intactas de caracoles mas ricas en especies (o sea, Sabal Palm Forest) no tienen contrapartes alteradas (restauradas o regeneradas) y por eso no fueron incluidas en las comparaciones emparejadas. Un análisis de anidamiento respalda esto, encontrando que estos ´unicos sitios intactos, que tienen la mayor riqueza de especies y ningun sitio comparable restaurado, contienen el grupo más grande de especies en el sur de Texas. La riqueza de especies de caracoles se correlacion significativamente con un gradiente de precipitación. Un modelo lineal general incorporando el promedio de cobertura del dosel, el promedio de altura vegetal, la abundancia de plantas, y la riqueza de especies de plantas muestra una correlación significativa con comunidades de caracoles. Este es el único muestreo comprensivo de las comunidades de caracoles de la cuenca baja del río Grande

    Transitions in digital personhood:Making sense of online activity in early retirement

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    We present findings from a qualitative study about how Internet use supports self-functioning following the life transition of retirement from work. This study recruited six recent retirees and included the deployment of OnLines, a design research artifact that logged and visualized key online services used by participants at home over four-weeks. The deployment was supported by pre- and post-deployment interviews. OnLines prompted participants’ reflection on their patterns of Internet use. Position Exchange Theory was used to understand retirees’ sense making from a lifespan perspective, informing the design of supportive online services. This paper delivers a three-fold contribution to the field of human-computer interaction, advancing a lifespan-oriented approach by conceptualizing the self as a dialogical phenomenon that develops over time, advancing the ageing discourse by reporting on retirees’ complex identities in the context of their life histories, and advancing discourse on research through design by developing OnLines to foster participant-researcher reflection informed by Self Psychology

    Greenland tidewater glacier advanced rapidly during era of Norse Settlement

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    ACKNOWLEDGMENTS We thank the Greenland Institute of Natural Resources for providing logistical support in Nuuk. Martin Blicher, Thomas Juul-Pedersen, and Johanne Vad are thanked for their research and field assistance. We acknowledge the support of the National Museum of Greenland for permission to undertake excavations near Norse ruin sites (permit 2015/03). Project funding was provided by the Leverhulme Trust Research Project grant 2014-093, and J.M. Lea was supported by funding from the Quaternary Research Association, British Society for Geomorphology, and a UK Research and Innovation (UKRI) Future Leaders Fellowship (MR/S017232/1). We thank two anonymous reviewers and the editor for constructive comments, which helped to substantially improve this paper. D.M. Pearce would like to dedicate this paper to her father Richard M. Pearce.Peer reviewedPostprin

    Ribosomal oxygenases are structurally conserved from prokaryotes to humans

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    2-Oxoglutarate (2OG)-dependent oxygenases have important roles in the regulation of gene expression via demethylation of N-methylated chromatin components1,2 and in the hydroxylation of transcription factors3 and splicing factor proteins4. Recently, 2OG-dependent oxygenases that catalyse hydroxylation of transfer RNA5,6,7 and ribosomal proteins8 have been shown to be important in translation relating to cellular growth, TH17-cell differentiation and translational accuracy9,10,11,12. The finding that ribosomal oxygenases (ROXs) occur in organisms ranging from prokaryotes to humans8 raises questions as to their structural and evolutionary relationships. In Escherichia coli, YcfD catalyses arginine hydroxylation in the ribosomal protein L16; in humans, MYC-induced nuclear antigen (MINA53; also known as MINA) and nucleolar protein 66 (NO66) catalyse histidine hydroxylation in the ribosomal proteins RPL27A and RPL8, respectively. The functional assignments of ROXs open therapeutic possibilities via either ROX inhibition or targeting of differentially modified ribosomes. Despite differences in the residue and protein selectivities of prokaryotic and eukaryotic ROXs, comparison of the crystal structures of E. coli YcfD and Rhodothermus marinus YcfD with those of human MINA53 and NO66 reveals highly conserved folds and novel dimerization modes defining a new structural subfamily of 2OG-dependent oxygenases. ROX structures with and without their substrates support their functional assignments as hydroxylases but not demethylases, and reveal how the subfamily has evolved to catalyse the hydroxylation of different residue side chains of ribosomal proteins. Comparison of ROX crystal structures with those of other JmjC-domain-containing hydroxylases, including the hypoxia-inducible factor asparaginyl hydroxylase FIH and histone Nε-methyl lysine demethylases, identifies branch points in 2OG-dependent oxygenase evolution and distinguishes between JmjC-containing hydroxylases and demethylases catalysing modifications of translational and transcriptional machinery. The structures reveal that new protein hydroxylation activities can evolve by changing the coordination position from which the iron-bound substrate-oxidizing species reacts. This coordination flexibility has probably contributed to the evolution of the wide range of reactions catalysed by oxygenases

    Nurse-led group consultation intervention reduces depressive symptoms in men with localised prostate cancer: a cluster randomised controlled trial

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    BACKGROUND: Radiotherapy for localised prostate cancer has many known and distressing side effects. The efficacy of group interventions for reducing psychological morbidity is lacking. This study investigated the relative benefits of a group nurse-led intervention on psychological morbidity, unmet needs, treatment-related concerns and prostate cancer-specific quality of life in men receiving curative intent radiotherapy for prostate cancer. METHODS: This phase III, two-arm cluster randomised controlled trial included 331 men (consent rate: 72&nbsp;%; attrition: 5&nbsp;%) randomised to the intervention (n&thinsp;=&thinsp;166) or usual care (n&thinsp;=&thinsp;165). The intervention comprised four group and one individual consultation all delivered by specialist uro-oncology nurses. Primary outcomes were anxious and depressive symptoms as assessed by the Hospital Anxiety and Depression Scale. Unmet needs were assessed with the Supportive Care Needs Survey-SF34 Revised, treatment-related concerns with the Cancer Treatment Scale and quality of life with the Expanded Prostate Cancer Index -26. Assessments occurred before, at the end of and 6 months post-radiotherapy. Primary outcome analysis was by intention-to-treat and performed by fitting a linear mixed model to each outcome separately using all observed data. RESULTS: Mixed models analysis indicated that group consultations had a significant beneficial effect on one of two primary endpoints, depressive symptoms (p = 0.009), and one of twelve secondary endpoints, procedural concerns related to cancer treatment (p = 0.049). Group consultations did not have a significant beneficial effect on generalised anxiety, unmet needs and prostate cancer-specific quality of life. CONCLUSIONS: Compared with individual consultations offered as part of usual care, the intervention provides a means of delivering patient education and is associated with modest reductions in depressive symptoms and procedural concerns. Future work should seek to confirm the clinical feasibility and cost-effectiveness of group interventions

    Greenland tidewater glacier advanced rapidly during era of Norse settlement

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    Our ability to improve prognostic modeling of the Greenland Ice Sheet relies on understanding the long-term relationships between climate and mass flux (via iceberg calving) from marine-terminating tidewater glaciers (TWGs). Observations of recent TWG behavior are widely available, but long-term records of TWG advance are currently lacking. We present glacial geomorphological, sedimentological, archaeological, and modeling data to reconstruct the ~20 km advance of Kangiata Nunaata Sermia (KNS; the largest tidewater glacier in southwest Greenland) during the first half of the past millennium. The data show that KNS advanced ~15 km during the 12th and 13th centuries CE at a rate of ~115 m a–1, contemporaneous with regional climate cooling toward the Little Ice Age and comparable to rates of TWG retreat witnessed over the past ~200 years. Presence of Norse farmsteads proximal to KNS demonstrates their resilience to climate change, manifest as a rapidly advancing TWG in a cooling climate. The results place limits on the magnitude of ice-margin advance and demonstrate TWG sensitivity to climate cooling as well as warming. These data combined with our grounding-line stability analysis provide a long-term record that validates approaches to numerical modeling aiming to link calving to climate
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