Showing papers by "University of Alcalá published in 2010"
TL;DR: The results showed that paraxanthine, caffeine and acetaminophen were the main individual pollutants usually found in concentrations over 20 ppb, and the hydroxyl radical reaction was the major pathway for the oxidative transformation of these compounds.
849 citations
National Technological University1, Technical University of Lisbon2, University of Turin3, University of Paris4, National Scientific and Technical Research Council5, New York University6, University of Naples Federico II7, University of Wisconsin–Milwaukee8, INAF9, Complutense University of Madrid10, University of California, Los Angeles11, Pierre-and-Marie-Curie University12, Karlsruhe Institute of Technology13, University of Chicago14, National University of La Plata15, Ohio State University16, Colorado State University17, Joseph Fourier University18, University of Alcalá19, University of Salento20, Istituto Nazionale di Fisica Nucleare21, University of Rome Tor Vergata22, Polish Academy of Sciences23, University of Leeds24, University of Siegen25, University of Granada26, Max Planck Society27, University of Catania28, Fermilab29, Academy of Sciences of the Czech Republic30, Radboud University Nijmegen31, University of Paris-Sud32, Pennsylvania State University33
TL;DR: The measurement of the depth of maximum, X{max}, of the longitudinal development of air showers induced by cosmic rays is described and the interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.
Abstract: We describe the measurement of the depth of maximum, Xmax, of the longitudinal development of air showers induced by cosmic rays. Almost four thousand events above 10^18 eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106 +35/-21) g/cm^2/decade below 10^(18.24 +/- 0.05) eV and (24 +/- 3) g/cm^2/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm^2. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.
558 citations
TL;DR: In this article, the authors reported a measurement of the flux of cosmic rays with unprecedented precision and statistics using the Pierre Auger Observatory based on fluorescence observations in coincidence with at least one surface detector.
461 citations
TL;DR: In this article, the authors present the methods to generate the input variables and the risk integration developed within the Firemap project (funded under the Spanish Ministry of Science and Technology) to map wildland fire risk for several regions of Spain.
436 citations
TL;DR: In this paper, anisotropy was measured by the fraction of arrival directions that are less than 3.1 degrees from the position of an active galactic nucleus within 75 Mpc (using the Veron-Cetty and Veron 12th catalog).
404 citations
11 Aug 2010-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: The Pierre Auger Observatory is a hybrid detector for ultra-high energy cosmic rays as discussed by the authors, which combines a surface array to measure secondary particles at ground level together with a fluorescence detector to measure the development of air showers in the atmosphere above the array.
Abstract: The Pierre Auger Observatory is a hybrid detector for ultra-high energy cosmic rays. It combines a surface array to measure secondary particles at ground level together with a fluorescence detector to measure the development of air showers in the atmosphere above the array. The fluorescence detector comprises 24 large telescopes specialized for measuring the nitrogen fluorescence caused by charged particles of cosmic ray air showers. In this paper we describe the components of the fluorescence detector including its optical system, the design of the camera, the electronics, and the systems for relative and absolute calibration. We also discuss the operation and the monitoring of the detector. Finally, we evaluate the detector performance and precision of shower reconstructions.
363 citations
Leiden University1, European Space Research and Technology Centre2, Cardiff University3, Kapteyn Astronomical Institute4, Max Planck Society5, California Institute of Technology6, United States Naval Research Laboratory7, University of Maryland, College Park8, University College London9, Harvard University10, University of Alcalá11, University of Lethbridge12, Chalmers University of Technology13, University of Crete14, National Radio Astronomy Observatory15, University of Virginia16, Chinese Academy of Sciences17, University of Copenhagen18, Spanish National Research Council19, University of Hawaii20, Cornell University21
TL;DR: In this article, a full high-resolution SPIRE FTS spectrum of the nearby ultraluminous infrared galaxy Mrk 231 is presented, including 25 lines, including CO J = 5-4 through J = 13-12, 7 rotational lines of H2O, 3 of OH+ and one line each of H 2O+, CH+, and HF.
Abstract: We present a full high resolution SPIRE FTS spectrum of the nearby ultraluminous infrared galaxy Mrk 231. In total 25 lines are detected, including CO J = 5-4 through J = 13-12, 7 rotational lines of H2O, 3 of OH+ and one line each of H2O+, CH+, and HF. We find that the excitation of the CO rotational levels up to J = 8 can be accounted for by UV radiation from star formation. However, the approximately flat luminosity distribution of the CO lines over the rotational ladder above J = 8 requires the presence of a separate source of excitation for the highest CO lines. We explore X-ray heating by the accreting supermassive black hole in Mrk 231 as a source of excitation for these lines, and find that it can reproduce the observed luminosities. We also consider a model with dense gas in a strong UV radiation field to produce the highest CO lines, but find that this model strongly overpredicts the hot dust mass in Mrk 231. Our favoured model consists of a star forming disk of radius 560 pc, containing clumps of dense gas exposed to strong UV radiation, dominating the emission of CO lines up to J = 8. X-rays from the accreting supermassive black hole in Mrk 231 dominate the excitation and chemistry of the inner disk out to a radius of 160 pc, consistent with the X-ray power of the AGN in Mrk 231. The extraordinary luminosity of the OH+ and H2O+ lines reveals the signature of X-ray driven excitation and chemistry in this region.
343 citations
TL;DR: In this paper, the results of the Herschel PACS survey of local ultra luminous infrared galaxies (ULIRGs) were presented, and all observed far-infrared fine-structure lines in the PACS range were detected and all were found to be deficient relative to the far infrared luminosity by 1-2 orders of magnitude compared with lower luminosity galaxies.
Abstract: In this first paper on the results of our Herschel PACS survey of local ultra luminous infrared galaxies (ULIRGs), as part of our SHINING survey of local galaxies, we present far-infrared spectroscopy of Mrk 231, the most luminous of the local ULIRGs, and a type 1 broad absorption line AGN. For the first time in a ULIRG, all observed far-infrared fine-structure lines in the PACS range were detected and all were found to be deficient relative to the far infrared luminosity by 1–2 orders of magnitude compared with lower luminosity galaxies. The deficits are similar to those for the mid-infrared lines, with the most deficient lines showing high ionization potentials. Aged starbursts may account for part of the deficits, but partial covering of the highest excitation AGN powered regions may explain the remaining line deficits. A massive molecular outflow, discovered in OH and 18 OH, showing outflow velocities out to at least 1400 km s −1 , is a unique signature of the clearing out of the molecular disk that formed by dissipative collapse during the merger. The outflow is characterized by extremely high ratios of 18 O/ 16 O suggestive of interstellar medium processing by advanced
329 citations
TL;DR: In this paper, several biomass estimation models based on LiDAR height, intensity, or height combined with intensity data were explored, and the results showed that intensity-based models provided more accurate predictions of the biomass fractions.
310 citations
TL;DR: In this paper, the authors investigated land cover changes in Central Chile using multi-temporal satellite imagery taken in 1975, 1985, 1999 and 2008 and found that the major trends in this highly dynamic landscape were reduction of dryland forest and conversion of shrubland to intensive land uses such as farmland.
297 citations
TL;DR: The use of capillary electromigration methods to analyze foods and food components is reviewed following the previous review by García‐Cañas and Cifuentes (Electrophoresis, 2008).
Abstract: In this work, the analysis of foods and food components using capillary electromigration methods is reviewed. The present work presents and discusses the main CE applications performed in Food Science and Technology including the new field of Foodomics, reviewing recent results on food quality and safety, nutritional value, storage, bioactivity, as well as applications of CE for monitoring food interactions and food processing. The CE analysis of a large variety of food-related molecules with different chemical properties, including amino acids, peptides, proteins, phenolic compounds, carbohydrates, DNA fragments, vitamins, toxins, pesticides, additives, and other minor compounds is described. The use of microchips, CE-MS, and chiral-CE in food analysis is also discussed as well as other current and foreseen trends in this area of research. Following the previous review by Castro-Puyana et al. (Electrophoresis, 2012, 33, 147–167), the current review covers the papers that were published from February 2011 to February 2013.
TL;DR: A palaeobotanical analysis of the Pleistocene floras and vegetation in the Iberian Peninsula shows the existence of patched landscapes with Pinus woodlands, deciduous and mixed forests, parklands (savannah-like), shrublands, steppes and grasslands as discussed by the authors.
TL;DR: In the remaining low-risk patients, this therapy is not effective as primary prophylaxis of thrombosis, and observation may be an adequate option, while antiplatelet therapy reduces the incidence of venous thromBosis in patients with JAK2-positive ET.
TL;DR: In this paper, the authors propose a methodology to measure spatial spillovers of transport infrastructure investment and to monetize them by distributing the costs of the infrastructures envisaged according to the regional distribution of the potential accessibility benefits.
University of Lisbon1, University of Wisconsin-Madison2, University of Waikato3, Uppsala University4, University of Ferrara5, Alfred Wegener Institute for Polar and Marine Research6, Russian Academy of Sciences7, Autonomous University of Madrid8, Rhodes University9, Sapienza University of Rome10, University of Alcalá11, Universidade Federal de Viçosa12, University of Valladolid13, University of Washington14
TL;DR: In this paper, the thermal state of permafrost and active layer in the Antarctic was investigated during the International Polar Year (IPY) and results obtained during the ANTPAS (Antarctic Permafrost, Active Layer and Active Layer) were presented.
Abstract: Results obtained during the International Polar Year (IPY) on the thermal state of permafrost and the active layer in the Antarctic are presented, forming part of ANTPAS (‘Antarctic Permafrost and ...
TL;DR: In this article, the fundamental-frequency positive-sequence grid voltage vector based on a generalization of the delayed signal cancellation method is proposed, which is implemented by sampling and storing the instantaneous αβ voltage vector.
Abstract: A novel scheme for obtaining the fundamental-frequency positive-sequence grid voltage vector based on a generalization of the delayed signal cancellation method is proposed in this paper. The technique is implemented by sampling and storing the instantaneous αβ voltage vector. A mathematical transformation is then proposed through which the current and delayed voltage vectors are combined. It is shown that the proposed transformation has unity gain for the fundamental-frequency positive-sequence voltage vector, while its gain is equal to zero for some chosen components. Cascaded transformations can then be used for eliminating the fundamental-frequency negative-sequence vector, as well as chosen positive- and negative-sequence harmonic vector components and, thus, for accurately obtaining the fundamental-frequency positive-sequence voltage vector. The output of the last transformation block is input to a synchronous reference frame phase-locked loop for detecting frequency and position of the positive-sequence vector. A proposal for making the scheme frequency adaptive is also presented. The good performance of the proposed method is verified with simulations and experiments by using distorted and unbalanced signals, containing fundamental-frequency as well as positive- and negative-sequence harmonic components. The proposed method frequency adaptation capability is also verified.
TL;DR: A systematization of various types of penalty based aggregation functions is provided, and it is shown how new aggregation functions can be constructed either analytically or numerically and many examples are provided.
TL;DR: In this article, an integrated policy framework, including policy features and specific measures that can be implemented to mitigate the barriers to eco-innovations, is presented, which highlights the multilayered conception of the obstacles to ecoinnovation, calls for a combination of environmental and technology policies adapted to the different barriers and characteristics of the technologies.
Abstract: This article elaborates an integrated policy framework, including policy features and specific measures that can be implemented to mitigate the barriers to eco-innovations. We claim that factors inhibiting the development and uptake of eco-innovations are multifaceted and stem from different sources. This systems view, which highlights the multilayered conception of the obstacles to eco-innovation, calls for a combination of environmental and technology policies adapted to the different barriers and characteristics of the technologies. Drawing on evolutionary economics, the article sheds light on the appropriate combinations of framework conditions and instruments that are most effective to promote eco-innovation, considering different barriers and eco-innovation types (process/product, mature/immature, and radical/incremental).
TL;DR: In this paper, the effects of scale on runoff and erosion change with the extent of degradation, resulting in a substantial loss of soil and water from disturbed systems, which could reinforce the degradation process through feedback mechanisms with vegetation.
Abstract: Received 17 February 2009; revised 31 October 2009; accepted 16 November 2009; published 6 April 2010 [1] In Earth and ecological sciences, an important, crosscutting issue is the relationship between scale and the processes of runoff and erosion In drylands, understanding this relationship is critical for understanding ecosystem functionality and degradation processes Recent work has suggested that the effects of scale may differ depending on the extent of degradation To test this hypothesis, runoff and sediment yield were monitored during a hydrological year on 20 plots of various lengths (1–15 m) These plots were located on a series of five reclaimed mining slopes in a Mediterranean‐dry environment The five slopes exhibited various degrees of vegetative cover and surface erosion A general decrease of unit area runoff was observed with increasing plot scale for all slopes Nevertheless, the amount of reinfiltrated runoff along each slope varied with the extent of degradation, being highest at the least degraded slope and vice versa In other words, unit area runoff decreased the least on the most disturbed site as plot length increased Unit area sediment yield declined with increasing plot length for the undisturbed and moderately disturbed sites, but it actually increased for the highly disturbed sites The different scaling behavior of the most degraded slopes was especially clear under high‐intensity rainfall conditions, when flow concentration favored rill erosion Our results confirm that in drylands, the effects of scale on runoff and erosion change with the extent of degradation, resulting in a substantial loss of soil and water from disturbed systems, which could reinforce the degradation process through feedback mechanisms with vegetation
TL;DR: An environmental application of the combination index-isobologram equation method is reported to determine the nature of toxicological interactions of three fibrates toward two aquatic bioluminescent organisms and proposes that the method can serve as a useful tool in ecotoxicological assessment.
TL;DR: The comparison of homologous editing sites in the mRNAs of angiosperm ndh genes provides a tool to investigate selective and permissive environmental conditions of past evolutionary events.
TL;DR: The study demonstrated prospectively the inverse and direct relationship between vascular calcification and bone mass and new information on the molecular mechanisms that may link this relationship is provided.
TL;DR: In this article, the authors compared the temporal trends of recently burned and unburned sites of boreal forest in central Canada calculated from two datasets: the Global Inventory, Monitoring, and Modeling Studies (GIMMS), which is the most commonly used 8 km dataset, and a new 1 km dataset developed by the Canadian Centre for Remote Sensing (CCRS).
Abstract: A number of remote sensing studies have evaluated the temporal trends of the normalized difference vegetation index (NDVI or vegetation greenness) in the North American boreal forest during the last two decades, often getting quite different results. To examine the effect that the use of different datasets might be having on the estimated trends, we compared the temporal trends of recently burned and unburned sites of boreal forest in central Canada calculated from two datasets: the Global Inventory, Monitoring, and Modeling Studies (GIMMS), which is the most commonly used 8 km dataset, and a new 1 km dataset developed by the Canadian Centre for Remote Sensing (CCRS). We compared the NDVI trends of both datasets along a fire severity gradient in order to evaluate the variance in regeneration rates. Temporal trends were calculated using the seasonal Mann-Kendall trend test, a rank-based, nonparametric test, which is robust against seasonality, nonnormality, heteroscedasticity, missing values, and serial dependence. The results showed contrasting NDVI trends between the CCRS and the GIMMS datasets. The CCRS dataset showed NDVI increases in all recently burned sites and in 50% of the unburned sites. Surprisingly, the GIMMS dataset did not capture the NDVI recovery in most burned sites and even showed NDVI declines in some burned sites one decade after fire. Between 50% and 75% of GIMMS pixels showed NDVI decreases in the unburned forest compared with <1% of CCRS pixels. Being the most broadly used dataset for monitoring ecosystem and carbon balance changes, the bias towards negative trends in the GIMMS dataset in the North American boreal forest has broad implications for the evaluation of vegetation and carbon dynamics in this region and globally.
TL;DR: In this article, the authors explore diverse factors that have induced the loss of forest areas in the State of Mexico from 1993 to 2000, using a technique for local analysis known as Geographically Weighted Regression (GWR).
TL;DR: The objectives of this work are to propose pre-processing methods and improvements in support vector machines to increase the accuracy achieved while the number of support vectors, and thus theNumber of operations needed in the test phase, is reduced.
TL;DR: The markers most frequently used to analyze cell death in protozoan parasites are discussed, paying special attention to changes in cell morphology, mitochondrial activity, chromatin structure and plasma membrane structure/permeability.
Abstract: The execution of the apoptotic death program in metazoans is characterized by a sequence of morphological and biochemical changes that include cell shrinkage, presentation of phosphatidylserine at the cell surface, mitochondrial alterations, chromatin condensation, nuclear fragmentation, membrane blebbing and the formation of apoptotic bodies. Methodologies for measuring apoptosis are based on these markers. Except for membrane blebbing and formation of apoptotic bodies, all other events have been observed in most protozoan parasites undergoing cell death. However, while techniques exist to detect these markers, they are often optimised for metazoan cells and therefore may not pick up subtle differences between the events occurring in unicellular organisms and multi-cellular organisms. In this review we discuss the markers most frequently used to analyze cell death in protozoan parasites, paying special attention to changes in cell morphology, mitochondrial activity, chromatin structure and plasma membrane structure/permeability. Regarding classical regulators/executors of apoptosis, we have reviewed the present knowledge of caspase-like and nuclease activities.
TL;DR: Investigation of the relative importance of direct and indirect facilitation by the nurse plant Retama sphaerocarpa on late-successional Quercus ilex seedlings mediated by herb suppression in a Mediterranean shrubland in 2006 and 2007 found both indirect and direct facilitation are important mechanisms for Q. ileX regeneration in Retamashrubland and their importance seems to vary with climatic conditions.
Abstract: 1. Competitive and facilitative interactions shape plant communities. Whereas a number of studies have addressed competition and direct facilitation among plants in dry ecosystems, indirect facilitation has received little attention. 2. We investigated the relative importance of direct and indirect facilitation by the nurse plant Retama sphaerocarpa on late-successional Quercus ilex seedlings mediated by herb suppression in a Mediterranean shrubland in 2006 and 2007. We also studied whether facilitation outcome depended on the size of the facilitated seedlings. 3. A field experiment was carried out to test the effect of (i) position of Q. ilex seedling with respect to shrub canopy (under shrubs or in gaps), (ii) herb competition (presence or absence), and (iii) seedling size. 2006 was an average rainfall year while 2007 had a much more humid spring and a dryer summer than 2006. 4. In both years, nurse shrubs reduced seedling mortality whereas herbs increased it. In the average rainfall year, seedling mortality under shrubs was unaffected by herbs whereas in gaps it was significantly higher in presence of herbs. This showed that the nurse shrub indirectly facilitated the seedlings by reducing the competitive capacity of herbs. Conversely, facilitation was predominately direct during the humid spring and dry summer year since herbs hindered seedling survival similarly under the nurse shrub and in gaps. The nurse shrub directly facilitated the seedlings by reducing seedling photoinhibition and water stress. 5. Improvement of environmental conditions by Retama benefited smaller seedlings but not larger seedlings since the nurse shrub reduced mortality of smaller seedlings relative to that in gaps, but this effect was not observed for larger seedlings. This indicates that individuals within a seedling population may not have the same response to facilitation. 6. Synthesis. Both indirect and direct facilitation are important mechanisms for Q. ilex regeneration in Retama shrubland and their importance seems to vary with climatic conditions. Indirect facilitation by release of herb competition under nurse shrubs is important in years of dry springs when competition between nurse shrubs and herbs is high, whereas direct facilitation mediated by microclimate amelioration increases with summer aridity.
TL;DR: Except for the green alga, the binary mixtures of docusate sodium with TCP or triclosan showed synergism at medium to high effect levels; the synergistic behaviour predominating in the ternary mixture and in the three tested species highlights the potential toxicological risk associated with the co-occurrence of this surfactant with other pollutants.
TL;DR: A new method to extend the range of Brillouin optical time domain analysis (BOTDA) systems is proposed that exploits the virtual transparency created by second-order Raman pumping in optical fibers and can be increased up to 100 km with 2 meter resolution.
Abstract: We propose and experimentally demonstrate a new method to extend the range of Brillouin optical time domain analysis (BOTDA) systems. It exploits the virtual transparency created by second-order Raman pumping in optical fibers. The idea is theoretically analyzed and experimentally demonstrated in a 50 km fiber. By working close to transparency, we also show that the measurement length of the BOTDA can be increased up to 100 km with 2 meter resolution. We envisage extensions of this technique to measurement lengths well beyond this value, as long as the issue of relative intensity noise (RIN) of the primary Raman pump can be avoided.
TL;DR: Several parameters with discriminant power have been used for olive oil traceability according to the olive variety used in the production of the oil, and they have been considered as traceability markers to the botanical origin and classified as compositional and genetical markers.
Abstract: This review provides an overview of traceability studies performed to date (April 2009) for olive oils. Special emphasis has been made on the botanical origin because high-quality monovarietal olive oils have been recently introduced on the markets and their quality control requires the development of new and powerful analytical tools as well as new regulations to avoid fraud to consumers. Several parameters with discriminant power have been used for olive oil traceability according to the olive variety used in the production of the oil. They have been considered as traceability markers to the botanical origin and classified, in this work, as compositional and genetical markers.