51 research outputs found

    Large difference in carbon emission - burial balances between boreal and arctic lakes

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    Lakes play an important role in the global carbon (C) cycle by burying C in sediments and emitting CO2 and CH4 to the atmosphere. The strengths and control of these fundamentally different pathways are therefore of interest when assessing the continental C balance and its response to environmental change. In this study, based on new high-resolution estimates in combination with literature data, we show that annual emission:burial ratios are generally ten times higher in boreal compared to subarctic – arctic lakes. These results suggest major differences in lake C cycling between biomes, as lakes in warmer boreal regions emit more and store relatively less C than lakes in colder arctic regions. Such effects are of major importance for understanding climatic feedbacks on the continental C sink – source function at high latitudes. If predictions of global warming and northward expansion of the boreal biome are correct, it is likely that increasing C emissions from high latitude lakes will partly counteract the presumed increasing terrestrial C sink capacity at high latitudes

    At the coalface and the cutting edge: general practitioners’ accounts of the rewards of engaging with HIV medicine

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    The interviews we conducted with GPs suggest that an engagement with HIV medicine enables clinicians to develop strong and long-term relationships with and expertise about the care needs of people living with HIV ‘at the coalface’, while also feeling connected with a broader network of medical practitioners and other professionals concerned with and contributing to the ever-changing world of science: ‘the cutting edge’. The general practice HIV prescriber is being modelled here as the interface between these two worlds, offering a rewarding opportunity for general practitioners to feel intimately connected to both community needs and scientific change

    Peatland carbon stocks and burn history : blanket bog peat core evidence highlights charcoal impacts on peat physical properties and long-term carbon storage

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    Peatlands are globally important carbon stores, yet both natural and human impacts can influence peatland carbon accumulation. Whilst changes in climate can alter peatland water tables leading to changes in peat decomposition, managed burning of vegetation has also been claimed to reduce peat accumulation. Particularly in the UK, blanket bog peatlands are rotationally burned to encourage heather re-growth on grouse shooting estates. However, the evidence of burning impacts on peat carbon stocks is very limited and contradictory. We assessed peat carbon accumulation over the last few hundred years in peat cores from three UK blanket bog sites under rotational grouse moor burn management. High resolution (0.5 cm) peat core analysis included dating based on spheroidal carbonaceous particles, determining fire frequency based on macro-charcoal counts and assessing peat properties such as carbon content and bulk density. All sites showed considerable net carbon accumulation during active grouse moor management periods. Averaged over the three sites, burns were more frequent, and carbon accumulation rates were also higher, over the period since 1950 than in the period 1700-1950. Carbon accumulation rates during the periods 1950-2015 and 1700-1850 were greater on the most frequently burnt site which was linked to bulk density and carbon accumulation rates showing a positive relationship with charcoal abundance. Charcoal input from burning was identified as a potentially crucial component in explaining reported differences in burning impacts on peat carbon accumulation, as assessed by carbon fluxes or stocks. Both, direct and indirect charcoal impacts on decomposition processes are discussed to be important factors, namely charcoal production converting otherwise decomposable carbon into an inert carbon pool, increasing peat bulk density, altering peat moisture and possibly negative impacts on soil microbial activity. This study highlights the value of peat core records in understanding management impacts on peat accumulation and carbon storage in peatlands

    Virtualización del Título Propio en Olivicultura y Elaiotecnia. Elaboración de Materiales

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    Es conocido que España es primer país productor de aceite de oliva del mundo, con un 40 % de la producción mundial y el 50 % de la producción de la Unión Europea, siendo la provincia de Jaén, con el 38,4 % de la producción española, la mayor zona productora del mundo en aceite de oliva. Sin embargo, se trata de un sector en el que la escasa profesionalización es, tal vez, su mayor debilidad.La Universidad de Jaén, consciente del importante papel que ha de jugar como Institución dinamizadora del desarrollo de su entorno, en el que el sector del olivar y del aceite de oliva tiene una enorme importancia, considera que es urgente formar titulados universitarios de grado superior que posean conocimientos integrales y solventes en olivicultura y elaiotecnia de modo que incorporados a las empresas del sector del olivar y el aceite de oliva o creando las suyas propias, lo modernicen y desarrollen, contribuyendo a dotarlo de cultura empresarial y al desarrollo socioeconómico y, por ende, al bienestar de los ciudadanos de la provincia

    Seguimiento en tumores carcinoides apendiculares

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    Large difference in carbon emission : burial balances between boreal and arctic lakes

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    Lakes play an important role in the global carbon (C) cycle by burying C in sediments and emitting CO2 and CH4 to the atmosphere. The strengths and control of these fundamentally different pathways are therefore of interest when assessing the continental C balance and its response to environmental change. In this study, based on new high-resolution estimates in combination with literature data, we show that annual emission: burial ratios are generally ten times higher in boreal compared to subarctic - arctic lakes. These results suggest major differences in lake C cycling between biomes, as lakes in warmer boreal regions emit more and store relatively less C than lakes in colder arctic regions. Such effects are of major importance for understanding climatic feedbacks on the continental C sink - source function at high latitudes. If predictions of global warming and northward expansion of the boreal biome are correct, it is likely that increasing C emissions from high latitude lakes will partly counteract the presumed increasing terrestrial C sink capacity at high latitudes

    Widely applicable metallacarborane reagents for ?-conjugated systems

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    The compounds [N(CH3)4][3,3?-Co(8-(p-C6H4C2H3)-1,2-C2B9H10)(1?,2?-C2B9H11)], [N(CH3)4][3,3?-Co(8-(p-C6H4CHO)-1,2-C2B9H10)(1?,2?-C2B9H11)], and [N(CH3)4][3,3?-Co(8-(m-C6H4CHO)-1,2-C2B9H10)(1?,2?-C2B9H11)] were synthesized using an easy methodology, in very good yields and large quantities, which are important requisites to be employed as starting reagents. They have been fully characterized by elemental analysis, IR, NMR, and MALDI-TOF-MS, and the crystal structures of [N(CH3)4][3,3?-Co(8-(p-C6H4C2H3)-1,2-C2B9H10)(1?,2?-C2B9H11)] and [N(CH3)4][3,3?-Co(8-(p-C6H4CHO)-1,2-C2B9H10)(1?,2?-C2B9H11)] were elucidated by single-crystal X-ray diffraction. These compounds, having terminal formyl and vinyl functional groups, are suitable platforms to involve the aromatic cobaltabisdicarbollide unit into extended ?-conjugated systems. It is expected that these synthons will facilitate the applicability of metallacarboranes in a wide variety of different fields, where ?-conjugated systems are needed to keep electronic communication

    Understanding the local and remote source contributions to ambient O3 during a pollution episode using a combination of experimental approaches in the Guadalquivir valley, southern Spain

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    The Guadalquivir Valley is one of three major O3 hotspots in Spain. An airborne and surface measurement campaign was carried out from July 9th to 11th, 2019 to quantify the local/regional O3 contributions using experimental approaches. Air quality and meteorology data from surface measurements, a microlight aircraft, a helium balloon, and remote sensing data (TROPOMI-NO2-ESA) were used to obtain the 3D distribution of O3 and various tracer pollutants. O3 accumulation over 2.5 days started with inputs from oceanic air masses transported inland by sea breezes, which drew O3 and its precursors from a local/regional origin to the northeastern end of the basin. The orographic–meteorological setting of the valley caused vertical recirculation of the air masses inside the valley that caused the accumulation by increasing regional background O3 concentration by 25–30 ppb. Furthermore, possible Mediterranean O3 contributions and additional vertical recirculation through the entrainment zone of the convective boundary layer also contributed. Using particulate matter finer than 2.5 μm (PM2.5), ultrafine particles (UFP), and black carbon (BC) as tracers of local sources, we calculated that local contributions increased regional O3 levels by 20 ppb inside specific pollution plumes transported by the breeze into the valley, and by 10 ppb during midday when flying over an area with abundant agricultural burning during the morning. Air masses that crossed the southern boundaries of the Betic system at mid-altitude (400–1850 m a.s.l.) on July 10th and 11th may have provided additional O3. Meanwhile, a decreasing trend at high altitudes (3000–5000 m a.s.l.) was observed, signifying that the impact of stratospheric O3 intrusion decreased during the campaign.The present work was supported by the Spanish Ministry for Ecological Transition (17CAES010); the “Agencia Estatal de Investigación” from the Spanish Ministry of Science, Innovation and Universities and FEDER funds under the project HOUSE (CGL2016-78594-R); the Agencia Estatal de Investigación (RTI2018-095937-B-I00); and the Generalitat de Catalunya (AGAUR 2017 SGR41). We would like to thank the Junta de Andalucía for providing us with air quality data, and the Spanish Met Office (AEMET) for providing meteorological data and facilitating staff and instrumentation for the soundings, as well as ESA for providing TROPOMI-NO2 data and NOAA for the HYSPLIT modeling tool. Cristina Carnerero thanks “Agencia Estatal de Investigación” for the grant received to carry out her PhD (FPI grant: BES-2017-080027). Carlos Pérez García-Pando acknowledges support by the AXA Research Fund, and the Spanish Ministry of Science, Innovation and Universities (RYC-2015-18690).Peer reviewe
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