713 research outputs found

    Should Forest Transition Theory include effects on forest fires? The case of Spain in the second half of the twentieth century

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    This paper analyses the increase in forest surface covered by trees in Spain in the second half of the twentieth century in the light of Forest Transition Theory and explores the existence of a statistical relationship between this process and forest fires. The study describes the afforestation policy based on new forest plantations developed by Franco''s Dictatorship in the period 1940–1988, linking it to the forest fires that occurred in the period 1968–2002, in order to determine, at a provincial level, the extent to which the afforestation activity affected the number of hectares burnt. The evidence shows a significant positive relationship between forest fires and the afforested hectares, especially 30–35 years after plantations. The effect increases when the model is implemented exclusively for the Cantabrian and Atlantic north-west provinces, especially affected by afforestation programmes. Our findings reinforce the need to complement certain models of Forest Transition based on tree plantations, taking into account the possible relationship that they have with fires, particularly in environmental contexts prone to fires

    Continuity, change, and geographical differences in Spain's firewood consumption: A new estimation (1860-2010)

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    Although firewood was the main energy source until recently in most parts of the world, our understanding of its consumption levels is still quite limited, even in regard to recent periods. The powerful impact of fossil energy carriers and their major effects on global ecology, economy and society have led us to underestimate the role firewood has continued to play during the energy transition. This article offers a new reconstruction of long-ter m firewood consumption in Spain, taking into consideration variables related to supply and demand, which are then used to reconstruct the production, appropriation and energy uses of firewood biomass. This new series distinguishes also between the origins (forest or crop firewood), and between different regional behaviors. The main findings indicate that total and per-inhabitant consumption has been greater than traditionally assumed; that there was major regional divergence, with consumption varying significantly from one area to another; that the decline in firewood consumption was gradual and later than previously thought; and that it increased or declined over time in a non-linear fashion. Moreover, the traditionally neglected estimation of the role of woody crops was found to be very significant in this process, as it represented between 20% and 70% of total consumption for the whole data series

    Thermal conductivity of ice polymorphs: a computational study.

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    Thermal transport in ice features an unusual response. In addition to its intrinsic scientific interest, an understanding of the mechanisms determining the thermal conductivity of ice might be relevant in climate modelling and planetary science. Accurate microscopic models can provide important molecular insight into these mechanisms. In this work, we quantify using molecular simulations and state of the art forcefields, the thermal conductivity of ice Ih, VI, VII and a plastic phase that has been proposed very recently at pressures in the GPa range. The TIP4P models used in this study underestimate significantly the thermal conductivity of ice Ih and ice VII, while they show good agreement with experimental measurements of ice VI. The discrepancies observed are examined by investigating the temperature dependence of the thermal conductivity. The simulations indicate that the models are too anharmonic and they potentially feature a higher structural disorder than the experimental systems. We suggest that at high pressures the simulated thermal conductivities can be rationalized in terms of the performance of the models in predicting the equation of state of ice. The thermal conductivity of the plastic phase is very similar to that of the coexisting ice VII. Since the water molecules in the plastic phase feature orientational disorder, these results indicate that the hydrogen bond network does not play a significant role in defining the thermal transport mechanisms of ice at high pressures

    Preliminary proposal of a metric for assessing and improving the impact of open-access heritage collections on Wikipedia

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    Institutions are increasingly moving toward providing access to collections digitally through open-access initiatives. Measuring this impact and providing metrics to benchmark progress remains an open challenge. This project aims to tackle part of this challenge, focusing on digitized image collections made available via Wikimedia. This work in progress is attempting to create a generalizable and consistent metric which can be used to maximize the potential impact of featuring an image from a collection within a certain Wikipedia entry. The metric considers several quantitative elements that represent specific aspects of impact and is demonstrated for a collection of landscape painting. We focus on impact through a public engagement lens, optimizing our metric to drive an increase in the number of people interacting with items in a collection. Future work will explore more advanced NLP methods and different collection types

    Enhancement of photoacoustic detection of inhomogeneities in polymers

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    We report a series of experiments on laser pulsed photoacoustic excitationin turbid polymer samples addressed to evaluate the sound speed in the samples and the presence of inhomogeneities in the bulk. We describe a system which allows the direct measurement of the speed of the detected waves by engraving the surface of the piece under study with a fiduciary pattern of black lines. We also describe how this pattern helps to enhance the sensitivity for the detection of an inhomogeneity in the bulk. These two facts are useful for studies in soft matter systems including, perhaps, biological samples. We have performed an experimental analysis on Grilon(R) samples in different situations and we show the limitations of the method.Comment: 8 pages, 7 figure

    Rift-margin extensional forced folds and salt tectonics in the eastern Basque-Cantabrian rift basin (western Pyrenees)

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    In this paper we present and discuss Cretaceous extensional folds of the eastern Basque-Cantabrian Basin (Northern Spain). Geometry and kinematics of folds is constrained by means of structural and sedimentological fieldwork integrated with geological mapping, revealing an intimate link between coeval folding, extensional faulting, and salt mobilization. In detail, the Mesozoic succession of the northwestern and southern borders of the Palaeozoic Bortziriak-Cinco Villas massif (eastern margin of the BCB) host late Albian–early Cenomanian syn-rift forced folds. The studied forced fold axes trend parallel and are located above main and inferred Cretaceous syn-sedimentary basement faults. Structural data indicate that these folds formed during the late Albian − early Cenomanian interval. The presence of Upper Triassic clay and evaporite outcrops along and/or close to the axes of folds and their stratigraphic relationship with Upper Cretaceous strata indicate their halokinetic origin and extrusion during folding. The trigger of salt tectonics is attributed to a basement extensional pulse during the Bay of Biscay – Pyrenean rifting. Related high subsidence-rates allowed salt to flow towards faults, forming salt walls and causing the inflation and folding of the overburden.grant BFI05.398 from the Basque Government to A. Bodego and grant AP98-44159606 from the Spanish Science Ministry to E. Iriarte. Funds were also supplied by Ministerio de Educación y Ciencia (MEC) – Ministerio de Ciencia e Innovación (MICINN) (projects CGL2006-05491/BTE and CGL2009-08545) and Euskal Herriko Unibertsitatea (UPV/EHU) (projects EHU06/62, UNESCO06/03 and EHUA15/18

    A newly discovered membrane at the origin of the proximal tendinous complex of the rectus femoris

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    Acord transformatiu CRUE-CSICPurpose: The rectus femoris (RF) forms the anterior portion of the quadriceps muscle group. It has a proximal tendinous complex (PTC) which is constituted by a direct tendon (DT), an indirect tendon (IT), and a variable third head. Direct and indirect tendons finally converge into a common tendon (CT). All the PTC shows a medially sloping in its proximal insertion.We investigated several anatomical specimens and discovered a new component: a membrane connecting the CT with the anterior superior iliac spine. Such membrane constitutes a new origin of the PTC. The aim of this study was to clarify whether this membrane was an anatomical variation of the PTC or a constant structure and to describe its morphology and trajectory. Material and methods: We dissected 42 cadaveric lower limbs and examined the architecture of the PTC. We paid special attention to the morphology and interaction patterns between the tendons and the membrane. Results: We demonstrated that the membrane is a constant component of the PTC. It has a lateral to medial trajectory and is in relation to the common tendon, the DT, and IT, which present a medial slope. This suggests that the membrane has an stabilizer role for the PTC, acting as a corrector of the inclined vector of the complex. Conclusion: The RF injuries are frequent in football. The newly discovered membrane is a constant component of the PTC and its integrity should be included in the algorithm to diagnose injuries

    Translational medicine in hereditary hemorrhagic telangiectasia

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    Scientific community have gained lots of new insights in the genetic and biochemical background of different conditions, rare diseases included, settling the basis for preclinical models that are helping to identify new biomarkers and therapeutic targets. Translational Medicine (TM) is an interdisciplinary area of biomedicine with an essential role in bench-to-bedside transition enhancement, generating a circular flow of knowledge transference between research environment and clinical setting, always centered in patient needs. Here, we present different tools used in TM and an overview of what is being done related to hereditary hemorrhagic telangiectasia (HHT), as a disease's model. This work is focused on how this combination of basic and clinical research impacts in HHT patient's daily clinical management and also looking into the future. Further randomized clinical trials with HHT patients should assess the findings of this bench-to-bedside transition. The benefits of this basic and clinical research combination, may not only be important for HHT patients but for patients with other vascular diseases sharing angiogenic disturbances

    Os vetores e a saúde pública no atual cenário de alterações climáticas: uma abordagem ao controlo de vectores

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