bluuebunny/crossref_metadata_2025 huggingface dataset:
La politique étrangère et l'élection présidentielle de 1981
Authors: Jansen Sabine
Published: June 2012

Résumé Les Français ont la réputation de n’être guère préoccupés par la politique étrangère. S’il est vrai que les questions internationales sont peu présentes lors des campagnes des élections présidentielles de 1965, 1969 et 1974, celle de 1981 fait figure d’exception. Les affaires extérieures y tiennent une place toute particulière. Dès lors, il s’agit d’en comprendre les raisons, en soulignant, à partir de l’automne 1979, le caractère dramatique de la conjoncture internationale qui marque un regain de la guerre froide. Hommes politiques, observateurs, journalistes et citoyens se font l’écho, au travers de discours, d’articles ou de sondages, d’une inquiétude croissante qui pèse sur l’évolution du rapport de forces entre les candidats à l’élection présidentielle d’avril-mai 1981. Le président de la République sortant, Valéry Giscard d’Estaing, héritier et garant de la traditionnelle politique gaulliste de détente avec l’Est, apparaît progressivement en porte-à-faux avec une opinion de plus en plus méfiante à l’égard de l’ urss , d’autant que cette politique contredit les efforts parallèles du président en vue de renforcer la cohésion franco-allemande et la solidarité atlantique face au déploiement des fusées nucléaires en Europe de l’Est. D’atout, la politique étrangère, domaine réservé du chef de l’État, devient, pour le président, un handicap exploité par son principal adversaire François Mitterrand dont, pourtant, la crédibilité aurait pu être affectée par un statut d’éternel opposant et d’allié d’un parti inféodé à l’Union soviétique. Le candidat du Parti socialiste tire habilement profit de la campagne antigiscardienne et antisoviétique d’une partie de la droite, comme de la virulence des attaques communistes dirigées contre lui et qui ont pour effet de rassurer l’électorat modéré. Même si, au cœur de la campagne électorale, les sondages nous éclairent davantage sur les intentions que sur les motivations, discours, questionnaires et commentaires de presse nous permettent de saisir les mouvements de l’opinion au fur et à mesure que se précisent les positions des candidats. L’activisme agressif de l’ urss réveille les vieux démons de la guerre froide. L’hostilité croissante de l’opinion à l’égard de la superpuissance communiste, mais aussi de la politique africaine du président sortant, joue un rôle indiscutable dans la montée du désamour à l’égard de Valéry Giscard d’Estaing, dont la politique étrangère soucieuse d’apaisement et de compromis n’apparaît plus en phase avec les attentes des Français.
Usability of cement paste containing carbon nanofibres as an anode in electrochemical chloride extraction from concrete
Authors: Moral B. del , Galao Ó. , Antón C. , Climent M. A. , Garcés P.
Published: June 2012

In the application of the electrochemical chloride extraction (ECE) technique, traditionally, the Ti-RuO2 wire netting has been used as the external anode. This article provides the results of the research based on the use of conductive cement paste with addition of carbon nanofibers (CNF) as anodes and its application in ECE. The tests were developed in concrete specimens previously contaminated with chloride. The efficiencies achieved were compared with those obtained using a traditional anode (Ti-RuO2) and cement pastes with the addition of other carbonaceous materials. The results show the feasibility of using conductive cement paste with CNF as the anode in the electrochemical extraction of chlorides in concrete, finding similar efficiencies to those obtained with traditional Ti-RuO2 wire netting but with the added advantage that it can be adapted to complex structural geometries as it can be applied as a paste.
Materials used to build the wooden vault over the Plenary Hall in the Spanish Senate Buiding
Authors: Bustamante R. , Monjo J. , Sánchez de Rojas M. I.
Published: June 2012

The constituent materials used to build the wooden vault over the Plenary Hall in the Spain’s Senate Building (ca 1814-1820) are analyzed in this paper. Characteristics of gypsum mortar applied on pine beams, boards and blockboard, have been determined. The esparto (=needlegrass) fibre provides a framework for the gypsum mortar to ensure adhesion and forming the surface of the dome. Physical-mechanical properties of the burnt clay-lightened gypsum mortars were determined with laboratory tests, while the composition of these materials was found with XRD,SEM and IR.
Primeras evidencias de arte mueble paleolítico en el sur de Portugal
Authors: Simón Vallejo María D. , Cortés Sánchez Miguel , Bicho Nuno
Published: June 2012

En este trabajo presentamos la primera evidencia de arte mueble paleolítico en el sur de Portugal: dos plaquetas de pizarra procedentes de niveles solutrenses del yacimiento de Vale Boi, zona occidental del Algarve (Portugal). La primera de las piezas es una pequeña placa (14,6 × 8,1 mm) que presenta sobre una de sus caras un ideomorfo grabado. La segunda (8 × 5 cm) cuenta con una superficie ocupada por óxido de hierro natural de color amarillento, tiene claros indicios de extracción de mineral para producir colorantes. En la superficie opuesta han sido grabados tres uros y una posible cierva. El estilo y secuencia de los grabados apuntan a un solo artista. Las características estilísticas de los zoomorfos concuerdan bien con los rasgos comunes del arte del ciclo Gravetiense final y Solutrense antiguo del País Valenciano, Andalucía y Valle de Côa (Portugal). Esta afinidad sintoniza asimismo con las fechas AMS de los niveles solutrenses de Vale Boi, datados entre ca. 20.500 y 19.500 BP.
El grafismo rupestre paleolítico de la cueva de El Mirón (Ramales de la Victoria, Cantabria, España): una propuesta para su datación estratigráfica
Authors: García Díez Marcos , González Morales Manuel R. , Straus Lawrence G.
Published: June 2012

Este artículo describe el arte parietal descubierto en la Cueva de El Mirón (Cantabria, España) en el curso de las excavaciones dirigidas en el yacimiento por MGM y LGS desde 1996. El arte consiste en grabados, la mayoría de ellos aparentemente no figurativos en su estado actual, pero hay una imagen de un caballo y otra de un posible bisonte. Todos los grabados se localizan en el fondo del gran vestíbulo, a plena luz, en íntima relación con los depósitos de origen humano. El caballo y los grabados lineales asociados a él en las paredes de la cueva pueden atribuirse al Magdaleniense inferior o medio sobre la base de su estilo y de la altura practicable sobre las superficies de ocupación de estos períodos. Datables con mayor precisión son dos grupos de grabados lineales sobre un gran bloque que pueden asignarse al Magdaleniense inferior cantábrico, un período bien caracterizado por sus obras de arte mueble, como los omóplatos grabados, en El Mirón y en otros varios yacimientos regionales. El bloque cayó de la pared de la cueva, con su cara exterior yaciendo sobre el nivel 110, datado por radiocarbono en 16.130 ± 250 y 16.520 ± 40 BP. A partir de entonces se grabó su cara originalmente interior. A continuación, el bloque y sus grabados fueron progresivamente recubiertos por sedimentos del Magdaleniense medio, superior y final datados entre ca. 14.500- 12.000 BP. En suma, el arte descubierto y estudiado hasta la fecha en El Mirón puede atribuirse al Magdaleniense inferior y medio, aunque el yacimiento estuvo habitado por los humanos al menos desde el Paleolítico medio hasta época medieval. El artículo concluye situando el arte parietal de El Mirón en el contexto de las otras numerosas (pero peor datadas) manifestaciones de arte rupestre de la cuenca del río Asón, en la Cantabria Oriental, que incluyen sitios tan notables como Venta de la Perra, Covalanas, La Haza y Cullalvera.
Nuevas evidencias sobre la organización espacial del asentamiento de la Edad del Cobre de Valencina de la Concepción: prospección geofísica entre La Pastora y Montelirio
Authors: Wheatley David , Strutt Kristian , García Sanjuán Leonardo , Mora Molina Coronada , Peinado Cucarella José
Published: June 2012

El gran asentamiento de la Edad del Cobre de Valencina de la Concepción ha sido objeto de numerosas investigaciones a lo largo de más de un siglo. Estas investigaciones han dado lugar a un registro arqueológico heterogéneo particularmente difícil de interpretar, y que presenta importantes vacíos y problemas. En este artículo se exponen los resultados de una prospección geofísica realizada en diciembre de 2004 entre los sectores de La Pastora y Montelirio en conexión con el proyecto de construcción de una carretera que finalmente nunca se llevó a cabo. Estas prospecciones revelaron numerosas estructuras previamente desconocidas. Los datos de esta prospección geofísica son valorados a la luz de los resultados obtenidos en la excavación llevada a cabo entre 2007 y 2008 en el sector inmediatamente adyacente de PP4-Montelirio, actualmente en proceso de estudio por nuestra parte, donde se identificaron varias decenas de estructuras prehistóricas (negativas no-megalíticas y megalíticas, funerarias y no-funerarias). Estos resultados arrojan nueva luz de cara a la interpretación espacial del asentamiento de Valencina de la Concepción posibilitando, por primera vez, cartografiar un sector amplio del mismo. A partir de estas nuevas evidencias se debaten cuestiones relativas a la densidad y diversidad de las estructuras presentes entre La Pastora y Montelirio así como en el propio sector PP4-Montelirio, sus posibles patrones espaciales y funcionales así como su diacronía. Esto plantea preguntas con respecto a la clasificación tradicional del sitio en zonas diferenciadas de “hábitat” y “necrópolis” y contribuye en general a una mejor comprensión de la organización espacial de este gran asentamiento prehistórico.
A media luz. Grabados de la Prehistoria Reciente en abrigos galaicos
Authors: Fábregas Valcarce Ramón , Rodríguez Rellán Carlos
Published: June 2012

La prospección sistemática de arte rupestre en el Ayuntamiento de Porto do Son (A Coruña) ha permitido la localización de casi dos centenares de grabados, dos de ellos en abrigos graníticos. A estos últimos se suman otros dos casos en las comarcas occidentales de Galicia. La temática presente es idéntica a la del arte galaico al aire libre, datado grosso modo en el III milenio a.C. Estos hallazgos plantean, por otra parte, la intencionada restricción física sobre la visualización de este fenómeno. La convivencia de motivos en el interior de cavidades con otros situados al aire libre e incluso en frisos verticales fácilmente perceptibles demuestra la variabilidad de estas manifestaciones y nos permite reflexionar sobre la audiencia a la que habrían estado destinadas las diferentes estaciones rupestres.
Entendiendo la movilidad humana mediante tecnologías espaciales: el papel de las áreas naturales de tránsito en el Suroeste de la Península Ibérica durante la Prehistoria Reciente
Authors: Murrieta-Flores Patricia
Published: June 2012

Investigaciones arqueológicas, históricas y etnográficas han demostrado como los ambientes de montaña tienen una profunda influencia en las dinámicas socioculturales de las comunidades que viven en ellos y en sus áreas vecinas. El desarrollo de estas sociedades tiende a producirse en los márgenes, usualmente lejos de los centros de poder político. Esta marginación se extiende también a la circulación en estas regiones, donde las cordilleras suelen constituir poderosos obstáculos debido a su configuración natural que juega un papel central en sus estrategias, comercio y movimiento humano. Durante la Prehistoria Reciente, la constitución de Sierra Morena Occidental (España) moldeó tanto las vías de tránsito a través de las montañas, como las rutas históricas de comunicación que atraviesan Andalucía. Utilizando una metodología de Sistemas de Información Geográfica diseñada específicamente para identificar características en el paisaje de particular relevancia para el movimiento humano (como corredores naturales, puntos de cruce y áreas naturales de tránsito), se examinó el papel que la accesibilidad del terreno tuvo para las comunidades de esa región durante la Prehistoria Reciente. Mediante este análisis concluimos que la ubicación de sus hábitats y lugares simbólicos se encuentran estrechamente relacionados con corredores naturales, posiblemente debido a una creciente importancia de las actividades de pastoreo.
¿La primera orfebrería del nordeste de la Península Ibérica? Nuevas aportaciones a partir de la cuenta áurea de Cau del Tossal Gros (Torroella del Montgrí, Baix Empordà, Girona)
Authors: Soriano Llopis Ignacio , Soler Subils Joaquim , Soler Masferrer Narcís
Published: June 2012

La cuenta bitroncocónica de oro localizada en la cueva sepulcral de Cau del Tossal Gros (Torroella de Montgrí, Baix Empordà, Girona) constituye la primera de este tipo conocida en la Península Ibérica. Estas cuentas son comunes en yacimientos del sur de Francia y se fechan de forma relativa en el Neolítico Final. Con el objetivo de establecer su proceso de producción se han realizado análisis de composición, radiológicos y traceológicos. Los resultados muestran la gran complejidad tecnológica de la pieza, sin paralelos conocidos en la Prehistoria peninsular. La datación radiocarbónica del yacimiento mediante tres fechas AMS y los materiales recuperados confirman una cronología de finales del IV-inicios del III milenio cal ANE. Finalmente, la comparación con los datos disponibles sobre la primera metalurgia del nordeste de la Península Ibérica permite proponer el posible origen, uso y valor social de esta peculiar cuenta áurea.
Nota sobre una estela ibérica duplicada (Calaceite, Teruel)
Authors: Simón Cornago Ignacio
Published: June 2012

Este trabajo llama la atención sobre la duplicación de la conocida estela de Santa Ana (Calaceite), perteneciente al grupo de las llamadas estelas del Bajo Aragón de la 2.ª Edad del Hierro. El error parte del catálogo de estos monumentos que Fernández Fuster editó en 1951. En él interpretó una fotografía parcial de la mencionada estela, publicada en Ars Hispaniae, como otro ejemplar, al que hizo proceder del poblado de San Antonio (Calaceite). Este error ha pervivido en la bibliografía hasta ahora.
Evaluation of Patients with Chronic Thromboembolic Pulmonary Hypertension for Pulmonary Endarterectomy
Authors: Auger William R. , Kerr Kim M. , Kim Nick H. , Fedullo Peter F.
Published: June 2012

Pulmonary hypertension as a result of chronic thromboembolic disease (CTEPH) is potentially curable with pulmonary endarterectomy surgery. Consequently, correctly diagnosing patients with this type of pulmonary hypertension and evaluating these patients with the goal of establishing their candidacy for surgical intervention is of utmost importance. And as advancements in surgical techniques have allowed successful resection of segmental‐level chronic thromboembolic disease, the number of CTEPH patients that are deemed suitable surgical candidates has expanded, making it even more important that the evaluation be conducted with greater precision. This article will review a diagnostic approach to patients with suspected chronic thromboembolic disease with an emphasis on the criteria considered in selecting patients for pulmonary endarterectomy surgery.
Diagnosis and Management of Pulmonary Hypertension Associated with Left Ventricular Diastolic Dysfunction
Authors: de Jesus Perez Vinicio A. , Haddad Francois , Zamanian Roham T.
Published: June 2012

Pulmonary hypertension (PH) is commonly seen in patients who present with left ventricular diastolic dysfunction (LVDD) and is considered a marker of poor prognosis. While PH in this setting is thought to result from pulmonary venous congestion, there is a subset of patients in which pulmonary pressures fail to improve with appropriate management of diastolic heart failure and go on to develop a clinical picture similar to that of patients with pulmonary arterial hypertension (PAH). Despite the utility of Doppler echocardiography and exercise testing in the initial evaluation of patients with suspected PH‐LVDD, the diagnosis can only be confirmed using right heart catheterization. Management of PH‐LVDD centers on both optimizing fluid management and afterload reduction to reducing left ventricular diastolic pressures and also increase pulmonary venous return. To date, there is no clear evidence that addition of PH‐specific drugs can improve clinical outcomes, and their use should only be considered in the setting of clinical trials. In conclusion, PH‐LVDD remains a challenging clinical entity that complicates the management of left ventricular dysfunction and significantly contributes to its morbidity and mortality. Determination of the optimal diagnostic and treatment strategies for this form of PH should be the goal of future studies.
Group V Phospholipase A2 Increases Pulmonary Endothelial Permeability Through Direct Hydrolysis of the Cell Membrane
Authors: Muñoz Nilda M. , Desai Anjali , Meliton Lucille N. , Meliton Angelo Y. , Zhou Tingting , Leff Alan R. , Dudek Steven M.
Published: June 2012

Acute lung injury (ALI) is characterized by inflammatory disruption of the alveolar—vascular barrier, resulting in severe respiratory compromise. Inhibition of the intercellular messenger protein, Group V phospholipase A2 (gVPLA2), blocks vascular permeability caused by LPS both in vivo and in vitro. In this investigation we studied the mechanism by which recombinant gVPLA2 increases permeability of cultured human pulmonary endothelial cells (EC). Exogenous gVPLA2 (500 nM), a highly hydrolytic enzyme, caused a significant increase in EC permeability that began within minutes and persisted for >10 hours. However, the major hydrolysis products of gVPLA2 (Lyso‐PC, Lyso‐PG, LPA, arachidonic acid) did not cause EC structural rearrangement or loss of barrier function at concentrations >10 μM. Higher concentrations (≥ 30 μM) of these membrane hydrolysis products caused some increased permeability but were associated with EC toxicity (measured by propidium iodide incorporation) that did not occur with barrier disruption by gVPLA2 (500 nM). Pharmacologic inhibition of multiple intracellular signaling pathways induced by gVPLA2 activity (ERK, p38, PI3K, cytosolic gIVPLA2) also did not prevent EC barrier disruption by gVPLA2. Finally, pretreatment with heparinase to prevent internalization of gVPLA2 did not inhibit EC barrier disruption by gVPLA2. Our data thus indicate that gVPLA2 increases pulmonary EC permeability directly through action as a membrane hydrolytic agent. Disruption of EC barrier function does not depend upon membrane hydrolysis products, gVPLA2 internalization, or upregulation of downstream intracellular signaling.
Leptin Levels Predict Survival in Pulmonary Arterial Hypertension
Authors: Tonelli Adriano R. , Aytekin Metin , Feldstein Ariel E. , Dweik Raed A.
Published: June 2012

Evidence suggests that leptin is involved in relevant processes in the cardiovascular system. Low serum leptin levels have been associated with increased cardiovascular events and mortality in patients with coronary artery, diabetes, or chronic kidney disease. We hypothesized that leptin is increased in pulmonary arterial hypertension (PAH) and provides prognostic information. We correlated leptin levels with clinical data and assessed its association with survival. Sixty‐seven patients with PAH and 29 healthy controls were studied. Plasma leptin levels were nonlinearly associated with BMI. Leptin level <15 μg/l was associated with higher mortality in PAH patients, with an adjusted (age, gender, BMI, and smoking status) hazard ratio of 3.8 (95% CI: 1.3–11.2), P=0.016. Similarly, PAH patients with leptin/BMI ratio <0.5 μg * m2/kg * I had worse survival than those with a level >0.5 μg * m2/kg * I (P=0.046 by log‐rank test). Two‐year mortality in PAH patients was 24%. A receiver operating characteristic curve using leptin/BMI ratio as the test variable and 2‐year mortality as the state variable showed an area under the curve of 0.74 (95% CI: 0.62–0.86). A leptin/BMI ratio cut‐off of 0.6 had a high sensitivity (94%) and negative predictive value (96%) for predicting death of any cause at 2 years. In PAH, plasma leptin levels are directly associated with BMI. Lower leptin levels, when adjusted by BMI, are associated with an increased overall mortality and leptin/BMI ratio has high negative predictive value for mortality at 2 years.
Mast Cell Number, Phenotype, and Function in Human Pulmonary Arterial Hypertension
Authors: Farha Samar , Sharp Jacqueline , Asosingh Kewal , Park Margaret , Comhair Suzy A. A. , Tang W. H. Wilson , Thomas Jim , Farver Carol , Hsieh Fred , Loyd James E. , Erzurum Serpil C.
Published: June 2012

A proliferation of mast cells around the small pulmonary blood vessels and the alveolar septae has been noted in models of pulmonary hypertension, and in plexiform lesions of pulmonary arterial hypertension (PAH) in patients. Here, we hypothesize that total mast cell numbers and activation are increased in PAH and that they contribute to vascular remodeling through cellular and soluble proangiogenic effectors. To test this, blood and urine were collected from patients with PAH (N=44), asthma (N=18) and healthy controls (N=29) to quantitate biomarkers of total body mast cell numbers and activation (total and mature tryptase, N‐methyl histamine, leukotriene LTE4 and prostaglandin PGD‐M). Serum total tryptase was higher in PAH than that in controls suggesting greater numbers of mast cells, but indicators of mast cell activation (mature tryptase, LTE4 and PGD‐M) were similar among PAH, asthma, and controls. Immunohistochemistry of lung tissues identified mast cells as primarily perivascular and connective tissue chymase+ type in PAH, rather than mucosal phenotype. Intervention with mast cell inhibitors cromolyn and fexofenadine was performed in 9 patients for 12 weeks to identify the influence of mast cell products on the pathologic proangiogenic environment. Treatment decreased total tryptase and LTE‐4 levels over time of treatment. This occurred in parallel to a drop in vascular endothelial growth factor (VEGF) and circulating proangiogenic CD34+CD133+ progenitor cells, which suggests that mast cells may promote vascular remodeling and dysfunction. In support of this, levels of exhaled nitric oxide, a vasodilator that is generally low in PAH, increased at the end of the 12‐week mast cell blockade and antihistamine. These results suggest that mast cells might contribute to the pulmonary vascular pathologic processes underlying PAH. More studies are needed to confirm their potential contribution to the disease.
Distinct Responses to Hypoxia in Subpopulations of Distal Pulmonary Artery Cells Contribute to Pulmonary Vascular Remodeling in Emphysema
Authors: Howard L. S. , Crosby A. , Vaughan P. , Sobolewski A. , Southwood M. , Foster M. L. , Chilvers E. R. , Morrell N. W.
Published: June 2012

We have shown previously that hypoxia inhibits the growth of distal human pulmonary artery smooth muscle cells (PASMC) isolated under standard normoxic conditions (PASMCnorm). By contrast, a subpopulation of PASMC, isolated through survival selection under hypoxia was found to proliferate in response to hypoxia (PASMChyp). We sought to investigate the role of hypoxia‐inducible factor (HIF) in these differential responses and to assess the relationship between HIF, proliferation, apoptosis, and pulmonary vascular remodeling in emphysema. PASMC were derived from lobar resections for lung cancer. Hypoxia induced apoptosis in PASMCnorm (as assessed by TUNEL) and mRNA expression of Bax and Bcl‐2, and induced proliferation in PASMChyp (as assessed by 3H‐thymidine incorporation). Both observations were mimicked by dimethyloxallyl glycine, a prolyl‐hydroxylase inhibitor used to stabilize HIF under normoxia. Pulmonary vascular remodeling was graded in lung samples taken from patients undergoing lung volume reduction surgery for severe heterogenous emphysema. Carbonic anhydrase IX expression in the medial compartment was used as a surrogate of medial hypoxia and HIF stabilization and increased with increasing vascular remodeling. In addition, a mixture of proliferation, assessed by proliferating‐cell nuclear antigen, and apoptosis, assessed by active caspase 3 staining, were both higher in more severely remodeled vessels. Hypoxia drives apoptosis and proliferation via HIF in distinct subpopulations of distal PASMC. These differential responses may be important in the pulmonary vascular remodeling seen in emphysema and further support the key role of HIF in hypoxic pulmonary hypertension.
Massive Dilatation of the Pulmonary Artery in Association with Pulmonic Stenosis and Pulmonary Hypertension
Authors: Morjaria Sejal , Grinnan Dan , Voelkel Norbert
Published: June 2012

Congenital pulmonary valve stenosis has been associated with the development of massive pulmonary arterial (PA) dilatation. Over time, this dilatation may distort surrounding structures and lead to compression of the left main coronary artery (LMCA) or the left mainstem bronchus. In this report, we describe a patient with a history of chronic thromboembolic pulmonary hypertension (CTEPH) and congenital pulmonic stenosis with massive PA dilatation. He develops exertional chest pain, presenting an unusual differential diagnosis. Novel diagnostic testing was performed to help narrow the differential diagnosis, and the patient responded well to pulmonary vasodilator treatment for progressive pulmonary hypertension.
Projections of mid-century summer air-quality for North America: effects of changes in climate and precursor emissions
Authors: Kelly J. , Makar P. A. , Plummer D. A.
Published: June 2012

Abstract. Ten year simulations of North American current and future air-quality were carried out using a regional air-quality model driven by a regional climate model, in turn driven by a general circulation model. Three separate summer scenarios were performed: a scenario representing the years 1997 to 2006, and two SRES A2 climate scenarios for the years 2041 to 2050. The first future climate scenario makes use of 2002 anthropogenic precursor emissions, and the second applied emissions scaling factors derived from the IPCC Representative Concentration Pathway 6 (RCP 6) scenario to estimate emissions for 2050 from existing 2020 projections. Ten-year averages of ozone and PM2.5 at North American monitoring network stations were used to evaluate the model's current chemical climatology. The model was found to have a similar performance for ozone as when driven by an operational weather forecast model. The PM2.5 predictions had larger negative biases, likely resulting from the absence of rainwater evaporation, and from sub-regional negative biases in the surface temperature fields, in the version of the climate model used here. The differences between the two future climate simulations and the current climate simulation were used to predict the changes to air-quality that might be expected in a future warmer climate, if anthropogenic precursor emissions remain constant at their current levels, versus if the RCP 6 emissions controls were adopted. Metrics of concentration, human health, and ecosystem damage were compared for the simulations. The scenario with future climate and current anthropogenic emissions resulted in worse air-quality than for current conditions – that is, the effect of climate-change alone, all other factors being similar, would be a worsening of air-quality. These effects are spatially inhomogeneous, with the magnitude and sign of the changes varying with region. The scenario with future climate and RCP 6 emissions for 2050 resulted in an improved air-quality, with decreases in key pollutant concentrations, in acute human mortality associated with air-pollution, and in sulphur and ozone deposition to the ecosystem. The positive outcomes of the RCP 6 emissions reductions were found to be of greater magnitude than the negative outcomes of climate change alone. The RCP 6 scenario however resulted in an increase in the deposition of nitrogen, as a result of increased ammonia emissions expected in that scenario, compared to current ammonia emissions levels. The results of the study raise the possibility that simultaneous reductions of greenhouse gases and air pollution precursors may further reduce air pollution levels, with the added benefits of an immediate reduction in the impacts of air pollution on human and ecosystem health. Further scenarios to investigate this possibility are therefore recommended.
Enhanced cold-season warming in semi-arid regions
Authors: Huang J. , Guan X. , Ji F.
Published: June 2012

Abstract. This study examined surface air temperature trends over global land from 1901–2009. It is found that the warming trend was particularly enhanced, in the boreal cold season (November to March) over semi-arid regions (with precipitation of 200–600 mm yr−1) showing a temperature increase of 1.53 °C as compared to the global annual mean temperature increase of 1.13 °C over land. In mid-latitude semi-arid areas of Europe, Asia, and North America, temperatures in the cold season increased by 1.41, 2.42, and 1.5 °C, respectively. The semi-arid regions contribute 44.46% to global annual-mean land-surface temperature trend. The mid-latitude semi-arid regions in the Northern Hemisphere contribute by 27.0% of the total, with the mid-latitude semi-arid areas in Europe, Asia, and North America accounting for 6.29%, 13.81%, and 6.85%, respectively. Such enhanced semi-arid warming (ESAW) imply drier and warmer trend of these regions.
A closure study of cloud condensation nuclei in the North China Plain using droplet kinetic condensational growth model
Authors: Yang F. , Xue H. , Deng Z. , Zhao C. , Zhang Q.
Published: June 2012

Abstract. Aerosol size distribution and cloud condensation nucleus (CCN) number concentration were measured in the North China Plain from 31 December 2009 to 20 January 2010. The CCN closure study was performed using these data and droplet kinetic condensational growth model. The calculated CCN concentration with the assumption of pure ammonium sulfate aerosol is 40–140% higher than that observed for the supersaturations in this study. A sensitivity test on aerosol solubility and mixing state indicates that 0.2–0.5 mass fraction of ammonium sulfate for internal mixture can lead to a ratio of 0.82–1.30 for the calculated to observed CCN concentrations, and that 0.4–0.7 mass fraction of ammonium sulfate for external mixture results in a ratio of 0.74–1.25 in the North China Plain during the time period of the field observations, suggesting that a relatively simple scheme may be used for CCN prediction in climate models for this region. Finally, we compare the calculated CCN concentrations from the kinetic condensational growth model and the equilibrium model. The kinetic condensational growth model can simulate droplet growth in a time period under a certain supersaturation, while the equilibrium model only predicts whether a certain aerosol can be activated as CCN under that supersaturation. The CCN concentration calculated with the kinetic model is higher than that with the equilibrium model at supersaturations of 0.056% and 0.083%, because some particles that are not activated from the equilibrium point-of-view can grow large enough to be considered as CCN in the kinetic model. While at a supersaturation of 0.17%, CCN concentration calculated with the kinetic model is lower than that with the equilibrium model, due to the limitation of droplet kinetic growth. The calculated CCN concentrations using the kinetic model and the equilibrium model are the same at supersaturations of 0.35% and 0.70%.
Transport of mesospheric H2O during and after the stratospheric sudden warming of January 2010: observation and simulation
Authors: Straub C. , Tschanz B. , Hocke K. , Kämpfer N. , Smith A. K.
Published: June 2012

Abstract. The transportable ground based microwave radiometer MIAWARA-C monitored the upper stratospheric and lower mesospheric (USLM) water vapor distribution over Sodankylä, Finland (67.4° N, 26.6° E) from January to June 2010. At the end of January, approximately 2 weeks after MIAWARA-C's start of operation in Finland, a stratospheric sudden warming (SSW) disturbed the circulation of the middle atmosphere. Shortly after the onset of the SSW water vapor rapidly increased at pressures between 1 and 0.01 hPa. Backward trajectory calculations show that this strong increase is due to the breakdown of the polar vortex and meridional advection of subtropical air to the Arctic USLM region. In addition, mesospheric upwelling in the course of the SSW led to an increase in observed water vapor between 0.1 and 0.03 hPa. After the SSW MIAWARA-C observed a decrease in mesospheric water vapor volume mixing ratio (VMR) due to the subsidence of H2O poor air masses in the polar region. Backward trajectory analysis and the zonal mean water vapor distribution from the Microwave Limb Sounder on the Aura satellite (Aura/MLS) indicate the occurrence of two regimes of circulation from 50° N to the North Pole: (1) regime of enhanced meridional mixing throughout February and (2) regime of an eastward circulation in the USLM region reestablished between early March and the equinox. The polar descent rate determined from MIAWARA-C's 5.2 parts per million volume (ppmv) isopleth is 350 ± 40 m d−1 in the pressure range 0.6 to 0.06 hPa between early February and early March. For the same time interval the descent rate in the same pressure range was determined using Transformed Eulerian Mean (TEM) wind fields simulated by means of the Whole Atmosphere Community Climate Model with Specified Dynamics (SD-WACCM). The average value of the SD-WACCM TEM vertical wind is 325 m d−1 while the along trajectory vertical displacement is 335 m d−1. The similar descent rates found indicate good agreement between the model and MIAWARA-C's measurements.
On the use of the correction factor with Japanese ozonesonde data
Authors: Morris G. A. , Labow G. , Akimoto H. , Takigawa M. , Fujiwara M. , Hasebe F. , Hirokawa J. , Koide T.
Published: June 2012

Abstract. In submitting data to the World Meteorological Organization (WMO) World Ozone and Ultraviolet Data Center (WOUDC), numerous ozonesonde stations include a correction factor (CF) that multiplies ozone concentration profile data so that the columns computed agree with column measurements from co-located ground-based and/or overpassing satellite instruments. We evaluate this practice through an examination of data from 4 Japanese ozonesonde stations: Kagoshima, Naha, Sapporo, and Tsukuba. While agreement between the sonde columns and Total Ozone Mapping Spectrometer (TOMS) or Ozone Mapping Instrument (OMI) is improved by use of the CF, agreement between the sonde ozone concentrations reported near the surface and data from surface monitors near the launch sites is negatively impacted. In addition, the agreement between the mean sonde columns without the CF and the ground-based Dobson instrument columns is improved by ~1.5% by using the McPeters et al. (1997) balloon burst climatology rather than the constant mixing ratio assumption for the above burst height column estimate. Limited comparisons of coincident ozonesonde profiles from Hokkaido University with those in the WOUDC database suggest that while the application of the CFs in the stratosphere improves agreement, it negatively impacts the agreement in the troposphere. Finally, unexplained trends and changing trends in the CFs appear over the last 20 yr. The overall trend in the CFs for the four Japanese ozonesonde stations from 1990–2010 is (−0.157 ± 0.032) × 10−2 yr−1; but from 1993–1999 the trend is (−2.21 ± 0.14) × 10−2 yr−1 and from 1999–2009 is (1.180 ± 0.059) × 10−2 yr−1, resulting in a statistically significant difference in CF trends between these two periods of (3.39 ± 0.15) × 10−2 yr−1. Given our analysis, we recommend the following: (1) use of the balloon burst climatology is preferred to a constant mixing ratio assumption for determining total column ozone with sonde data; (2) if CFs are applied, their application should probably be restricted to altitudes above the tropopause; (3) only sondes that reach at least 32 km (10.5 hPa) before bursting should be used in data validation and/or ozone trend studies; and (4) all ozone trend studies employing Japanese sonde data should be revisited after a careful examination of the impact of the CF on the calculated ozone trends.
Basin-wide variations in Amazon forest structure and function are mediated by both soils and climate
Authors: Quesada C. A. , Phillips O. L. , Schwarz M. , Czimczik C. I. , Baker T. R. , Patiño S. , Fyllas N. M. , Hodnett M. G. , Herrera R. , Almeida S. , Alvarez Dávila E. , Arneth A. , Arroyo L. , Chao K. J. , Dezzeo N. , Erwin T. , di Fiore A. , Higuchi N. , Honorio Coronado E. , Jimenez E. M. , Killeen T. , Lezama A. T. , Lloyd G. , López-González G. , Luizão F. J. , Malhi Y. , Monteagudo A. , Neill D. A. , Núñez Vargas P. , Paiva R. , Peacock J. , Peñuela M. C. , Peña Cruz A. , Pitman N. , Priante Filho N. , Prieto A. , Ramírez H. , Rudas A. , Salomão R. , Santos A. J. B. , Schmerler J. , Silva N. , Silveira M. , Vásquez R. , Vieira I. , Terborgh J. , Lloyd J.
Published: June 2012

Abstract. Forest structure and dynamics vary across the Amazon Basin in an east-west gradient coincident with variations in soil fertility and geology. This has resulted in the hypothesis that soil fertility may play an important role in explaining Basin-wide variations in forest biomass, growth and stem turnover rates. Soil samples were collected in a total of 59 different forest plots across the Amazon Basin and analysed for exchangeable cations, carbon, nitrogen and pH, with several phosphorus fractions of likely different plant availability also quantified. Physical properties were additionally examined and an index of soil physical quality developed. Bivariate relationships of soil and climatic properties with above-ground wood productivity, stand-level tree turnover rates, above-ground wood biomass and wood density were first examined with multivariate regression models then applied. Both forms of analysis were undertaken with and without considerations regarding the underlying spatial structure of the dataset. Despite the presence of autocorrelated spatial structures complicating many analyses, forest structure and dynamics were found to be strongly and quantitatively related to edaphic as well as climatic conditions. Basin-wide differences in stand-level turnover rates are mostly influenced by soil physical properties with variations in rates of coarse wood production mostly related to soil phosphorus status. Total soil P was a better predictor of wood production rates than any of the fractionated organic- or inorganic-P pools. This suggests that it is not only the immediately available P forms, but probably the entire soil phosphorus pool that is interacting with forest growth on longer timescales. A role for soil potassium in modulating Amazon forest dynamics through its effects on stand-level wood density was also detected. Taking this into account, otherwise enigmatic variations in stand-level biomass across the Basin were then accounted for through the interacting effects of soil physical and chemical properties with climate. A hypothesis of self-maintaining forest dynamic feedback mechanisms initiated by edaphic conditions is proposed. It is further suggested that this is a major factor determining endogenous disturbance levels, species composition, and forest productivity across the Amazon Basin.
Effects of elevated CO2 and N fertilization on plant and soil carbon pools of managed grasslands: a meta-analysis
Authors: Sillen W. M. A. , Dieleman W. I. J.
Published: June 2012

Abstract. Elevated atmospheric CO2 levels and increasing nitrogen deposition both stimulate plant production in terrestrial ecosystems. Moreover, nitrogen deposition could alleviate an increasing nitrogen limitation experienced by plants exposed to elevated CO2 concentrations. However, an increased rate of C flux through the soil compartment as a consequence of elevated CO2 concentrations has been suggested to limit C sequestration in terrestrial ecosystems, questioning the potential for terrestrial C uptake to mitigate increasing atmospheric CO2 concentrations. Our study used data from 77 published studies applying elevated CO2 and/or N fertilization treatment to monitor carbon storage potential in grasslands, and considered the influence of management practices involving biomass removal or irrigation on the elevated CO2 effects. Our results confirmed a positive effect of elevated CO2 levels and nitrogen fertilization on plant growth, but revealed that N availability is essential for the increased C influx under elevated CO2 to propagate into belowground C pools. However, moderate nutrient additions also promoted decomposition processes in elevated CO2, reducing the potential for increased soil C storage. An important role was attributed to the CO2 response of root biomass in soil carbon responses to elevated CO2, since there was a lower potential for increases in soil C content when root biomass increased. Future elevated CO2 concentrations and increasing N deposition might thus increase C storage in plant biomass, but the potential for increased soil C storage is limited.
Environmental variations in a semi-enclosed embayment (Amvrakikos Gulf, Greece) – reconstructions based on benthic foraminifera abundance and lipid biomarker pattern
Authors: Naeher S. , Geraga M. , Papatheodorou G. , Ferentinos G. , Kaberi E. , Schubert C. J.
Published: June 2012

Abstract. The evolution of environmental changes during the last decades and the impact on the living biomass in the western part of Amvrakikos Gulf was investigated using abundances of benthic foraminifera and lipid biomarker concentrations. These proxies indicated that the gulf has dramatically changed due to eutrophication. Eutrophication has led to a higher productivity, a higher bacterial biomass, shifts towards opportunistic and tolerant benthic foraminifera species (e.g. B. elongata, N. turgida, T. agglutinans, A. tepida) and a lower benthic species density. Close to the Preveza Straits (connection between the gulf and the Ionian Sea), the benthic assemblages appeared to be less productive and more diversified under more oxygenated conditions. Sea grass meadows largely contributed to the organic matter at this sampling site. Isorenieratane, chlorobactane and lycopane together with oxygen monitoring data indicated that anoxic (and partly euxinic) conditions prevailed seasonally throughout the western part of the gulf with more severe hypoxia towards the east. Increased surface water temperatures have led to a higher stratification, which reduced oxygen resupply to bottom waters. These developments are reasons for mass mortality events and ecosystem decline observed in Amvrakikos Gulf.
The influence of vegetation on the ITCZ and South Asian monsoon in HadCM3
Authors: McCarthy M. P. , Sanjay J. , Booth B. B. B. , Krishna Kumar K. , Betts R. A.
Published: June 2012

Abstract. The role of global vegetation on the large-scale tropical circulation is examined in the version 3 Hadley Centre climate model (HadCM3). Alternative representations of global vegetation cover from observations and a dynamic global vegetation model (DGVM) were used as the land-cover component for a number of HadCM3 experiments under a nominal present day climate state, and compared to the simulations using the standard land cover map of HadCM3. The alternative vegetation covers result in a large scale cooling of the Northern Hemisphere extra-tropics relative to the HadCM3 standard, resulting in a southward shift in the location of the inter-tropical convergence zone (ITCZ). A significant reduction in Indian monsoon precipitation is also found, which is related to a weakening of the South Asian monsoon circulation, broadly consistent with documented mechanisms relating to temperature and snow perturbations in the Northern Hemisphere extra-tropics in winter and spring, delaying the onset of the monsoon. The role of the Northern Hemisphere extra-tropics on tropical climate is demonstrated, with an additional representation of vegetation cover based on DGVM simulated changes in Northern Hemisphere vegetation from the end of the 21st Century. This experiment shows that through similar processes the simulated extra-tropical vegetation changes in the future contribute to a strengthening of the South Asian monsoon in this model. These findings provide renewed motivation to give careful consideration to the role of global scale vegetation feedbacks when looking at climate change, and its impact on the tropical circulation and South Asian monsoon in the latest generation of Earth System models.
Describing Earth System Simulations with the Metafor CIM
Authors: Lawrence B. N. , Balaji V. , Bentley P. , Callaghan S. , DeLuca C. , Denvil S. , Devine G. , Elkington M. , Ford R. W. , Guilyardi E. , Lautenschlager M. , Morgan M. , Moine M.-P. , Murphy S. , Pascoe C. , Ramthun H. , Slavin P. , Steenman-Clark L. , Toussaint F. , Treshansky A. , Valcke S.
Published: June 2012

Abstract. The Metafor project has developed a Common Information Model (CIM) using the ISO1900 series formalism to describe the sorts of numerical experiments carried out by the earth system modelling community, the models they use, and the simulations that result. Here we describe the mechanism by which the CIM was developed, and its key properties. We introduce the conceptual and application versions and the controlled vocabularies developed in the context of supporting the fifth Coupled Model Intercomparison Project (CMIP5). We describe how the CIM has been used in experiments to describe model coupling properties and describe the near term expected evolution of the CIM.
Training hydrologists to be ecohydrologists and play a leading role in environmental problem solving
Authors: McClain M. E. , Chícharo L. , Fohrer N. , Gaviño Novillo M. , Windhorst W. , Zalewski M.
Published: June 2012

Abstract. Ecohydrology is a relatively new and rapidly growing subject area in the hydrology curriculum. It is a trans-disciplinary science derived from the larger earth systems science movement and examining mutual interactions of the hydrological cycle and ecosystems. It is also an applied science focused on problem solving and providing sound guidance to catchment-scale integrated land and water resources management. The principle spheres of ecohydrology include (i) climate-soil-vegetation-groundwater interactions at the land surface with special implications for land use, food production and climate change; (ii) riparian runoff, flooding, and flow regime dynamics in river corridors with special implications for water supply, water quality, and inland fisheries; and (iii) fluvial and groundwater inputs to lakes/reservoirs, estuaries, and coastal zones with special implications for water quality and fisheries. We propose an educational vision focused on the development of professional and personal competencies to impart a depth of scientific knowledge in the theory and practice of ecohydrology and a breadth of cross-cutting knowledge and skills to enable ecohydrologists to effectively collaborate with associated scientists and communicate results to resource managers, policy-makers, and other stakeholders. In-depth knowledge in hydrology, ecology, and biogeochemistry is emphasized, as well as technical skills in data collection, modeling, and statistical analysis. Cross-cutting knowledge is framed in the context of integrated water resources management. Personal competencies to be fostered in educational programs include creative thinking, cooperation, communication, and leadership. We consider a life-long learning context but highlight the importance of master's level training in the professional formation of ecohydrologists.