1,124 research outputs found

    ‘That eccentric use of land at the top of the hill’: Cemeteries and stories of the city

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    Most contemporary research accounts for conflict within cemetery space, but does not consider the potentially contested and poorly understood role of cemeteries within their broader cityscape. This study draws on stories from cemetery managers across England and Wales to narrate this multifunctionality, as they hold the pivotal role which oversees both the day-to-day running of the cemetery, and its strategic role within a given municipality. The study outlines how cemeteries hold multiple functions in the cities in which they are located, specifically contributing to greenspace or green infrastructure, civic identity and local place attachment. These varying city level roles in turn impact on what is deemed (il)legitimate behaviour within the cemetery. Moreover, they raise important considerations for urban planners and policymakers who currently have little guidance on planning for new or existing cemeteries but are critical in the ongoing successful development of cities

    Orbital and Suborbital‐Scale Variations of Productivity and Sea Surface Conditions in the Gulf of Alaska During the Past 54,000 Years: Impact of Iron Fertilization by Icebergs and Meltwater

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    As a high-nutrient and low-chlorophyll region, the modern Gulf of Alaska (GoA) is strongly impacted by the limitation of iron. Paleostudies along the Alaskan slope have mainly focused on reconstructing environmental conditions over the past 18 ka. Based on micropaleontological, biogeochemical, and sedimentological parameters, we explore a sediment record covering the past 54 ka at Integrated Ocean Drilling Program Site U1419 to understand the impact of orbital- and suborbital-scale climate variability on productivity and sea-surface conditions. Close to the Cordilleran Ice Sheet (CIS), Site U1419 is ideally located to elucidate how the evolution of a large ice mass and glacial processes affected orbital- and suborbital-scale changes in nutrients (e.g., iron) supply. Meltwater discharge from the northern CIS impacted sea surface dynamics of GoA coastal waters. The corresponding increases in bulk biogenic concentrations during Marine Isotope Stage (MIS) 3 and MIS 2 (54–17 ka) suggests a direct impact from iron fertilization. The lack of a consistent relationship between productivity and SST suggests that cooling of surface waters was not the dominant control on primary producers. The inundation of the subaerially exposed continental shelf during the last deglacial (17–10 ka) warming could have served as a major micronutrient source, accounting for a deglacial peak in production. Low productivity after the last deglaciation suggests reduced iron availability, which we link to reduced meltwater inputs from smaller ice masses onshore. Our multiproxy approach reveals a more comprehensive picture of late Quaternary productivity variations compared to earlier studies along the Alaskan margin. The impact of tidewater glaciers and meltwater discharge on past marine productivity and nutrient budget dynamics of high-latitude coastal regions is discussed

    Are spherulitic lacustrine carbonates an expression of large-scale mineral carbonation? : A case study from the East Kirkton Limestone, Scotland

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    BP Exploration Co. is thanked for funding, and particularly the Carbonate Team for supporting this research and for fruitful discussions. West Lothian Council and Scottish Natural Heritage are thanked for allowing access and permission for sampling the site. The Core Store Team at BGS Keyworth is particularly acknowledged for their assistance. Mark Anderson, Tony Sinclair (University of Hull), and Bouk Lacet (VU University Amsterdam) are thanked for technical support. Anne Kelly (SUERC) for carrying out the Strontium Isotope analyses. Mark Tyrer is thanked for his advice on PHREEQC modelling.Peer reviewedPostprin

    High-Resolution Magnetic Resonance Imaging of the Regenerating Adult Zebrafish Heart

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    The adult zebrafish is a well-established model for studying heart regeneration, but due to its tissue opaqueness, repair has been primarily assessed using destructive histology, precluding repeated investigations of the same animal. We present a high-resolution, non-invasive in vivo magnetic resonance imaging (MRI) method incorporating a miniature respiratory and anaesthetic perfusion set-up for live adult zebrafish, allowing for visualization of scar formation and heart regeneration in the same animal over time at an isotropic 31 µm voxel resolution. To test the method, we compared well and poorly healing cardiac ventricles using a transgenic fish model that exhibits heat-shock (HS) inducible impaired heart regeneration. HS-treated groups revealed persistent scar tissue for 10 weeks, while control groups were healed after 4 weeks. Application of the advanced MRI technique allowed clear discrimination of levels of repair following cryo- and resection injury for several months. It further provides a novel tool for in vivo time-lapse imaging of adult fish for non-cardiac studies, as the method can be readily applied to image wound healing in other injured or diseased tissues, or to monitor tissue changes over time, thus expanding the range of questions that can be addressed in adult zebrafish and other small aquatic species

    Late Pliocene Cordilleran Ice Sheet development with warm northeast Pacific sea surface temperatures

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    The initiation and evolution of the Cordilleran Ice Sheet are relatively poorly constrained. International Ocean Discovery Program (IODP) Expedition 341 recovered marine sediments at Site U1417 in the Gulf of Alaska (GOA). Here we present alkenone-derived sea surface temperature (SST) analyses alongside ice-rafted debris (IRD), terrigenous, and marine organic matter inputs to the GOA through the late Pliocene and early Pleistocene. The first IRD contribution from tidewater glaciers in southwest Alaska is recorded at 2.9 Ma, indicating that the Cordilleran Ice Sheet extent increased in the late Pliocene. A higher occurrence of IRD and higher sedimentation rates in the GOA during the early Pleistocene, at 2.5 Ma, occur in synchrony with SSTs warming on the order of 1 degrees C relative to the Pliocene. All records show a high degree of variability in the early Pleistocene, indicating highly efficient ocean-climate-ice interactions through warm SST-ocean evaporation-orographic precipitation-ice growth mechanisms. A climatic shift towards ocean circulation in the subarctic Pacific similar to the pattern observed during negative Pacific Decadal Oscillation (PDO) conditions today occurs with the development of more extensive Cordilleran glaciation and may have played a role through increased moisture supply to the subarctic Pacific. The drop in atmospheric CO2 concentrations since 2.8 Ma is suggested as one of the main forcing mechanisms driving the Cordilleran glaciation

    Chromospheric magnetic field and density structure measurements using hard X-rays in a flaring coronal loop

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    <p><b>Aims:</b> A novel method of using hard X-rays as a diagnostic for chromospheric density and magnetic structures is developed to infer sub-arcsecond vertical variation of magnetic flux tube size and neutral gas density.</p> <p><b>Methods:</b> Using Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) X-ray data and the newly developed X-ray visibilities forward fitting technique we find the FWHM and centroid positions of hard X-ray sources with sub-arcsecond resolution (~0.2'') for a solar limb flare. We show that the height variations of the chromospheric density and the magnetic flux densities can be found with an unprecedented vertical resolution of ~150 km by mapping 18-250 keV X-ray emission of energetic electrons propagating in the loop at chromospheric heights of 400-1500 km.</p> <p><b>Results:</b> Our observations suggest that the density of the neutral gas is in good agreement with hydrostatic models with a scale height of around 140 30 km. FWHM sizes of the X-ray sources decrease with energy suggesting the expansion (fanning out) of magnetic flux tubes in the chromosphere with height. The magnetic scale height B(z)(dB/dz)-1 is found to be of the order of 300 km and a strong horizontal magnetic field is associated with noticeable flux tube expansion at a height of ~900 km.</p&gt

    Antarctic Intermediate Water properties since 400 ka recorded in infaunal (Uvigerina peregrina) and epifaunal (Planulina wuellerstorfi) benthic foraminifera

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    Reconstruction of intermediate water properties is important for understanding feedbacks within the ocean-climate system, particularly since these water masses are capable of driving high–low latitude teleconnections. Nevertheless, information about intermediate water mass evolution through the late Pleistocene remains limited. This paper examines changes in Antarctic Intermediate Water (AAIW), the most extensive intermediate water mass in the modern ocean through the last 400 kyr using the stable isotopic composition (δ18O and δ13C) and trace element concentration (Mg/Ca and B/Ca) of two benthic foraminiferal species from the same samples: epifaunal Planulina wuellerstorfi and infaunal Uvigerina peregrina. Our results confirm that the most reasonable estimates of AAIW temperature and Δ[CO2−3] are generated by Mg/CaU. peregrina and B/CaP. wuellerstorfi, respectively. We present a 400 kyr record of intermediate water temperature and Δ[CO2−3] from a sediment core from the Southwest Pacific (DSDP site 593; 40°30′S, 167°41′E, 1068 m water depth), which lies within the core of modern AAIW. Our results suggest that a combination of geochemical analyses on both infaunal and epifaunal benthic foraminiferal species yields important information about this critical water mass through the late Pleistocene. When combined with two nearby records of water properties from deeper depths, our data demonstrate that during interglacial stages of the late Pleistocene, AAIW and Circumpolar Deep Water (CPDW) have more similar water mass properties (temperature and δ13C), while glacial stages are typified by dissimilar properties between AAIW and CPDW in the Southwest Pacific. Our new Δ[CO2−3] record shows short time-scale variations, but a lack of coherent glacial–interglacial variability indicating that large quantities of carbon were not stored in intermediate waters during recent glacial periods

    Biomarker proxies for reconstructing Quaternary climate and environmental change

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    To reconstruct past environmental changes, a range of indirect or proxy approaches can be applied to Quaternary archives. Here, we review the complementary and novel insights which have been provided by the analysis of chemical fossils (biomarkers). Biomarkers have a biological source that can be highly specific (e.g., produced by a small group of organisms) or more general. We show that biomarkers are able to quantify key climate variables (particularly water and air temperature) and can provide qualitative evidence for changes in hydrology, vegetation, human-environment interactions and biogeochemical cycling. In many settings, biomarker proxies provide the opportunity to simultaneously reconstruct multiple climate or environmental variables, alongside complementary and long-established approaches to palaeo-environmental reconstruction. Multi-proxy studies have provided rich sets of data to explore both the drivers and impacts of palaeo-environmental change. As new biomarker proxies continue to be developed and refined, there is further potential to answer emerging questions for Quaternary science and environmental change
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