bluuebunny/crossref_metadata_2025 huggingface dataset:
La modernité gandhienne de l'Intifada arabe
Authors: Ravenel Bernard
Published: June 2011

La révolution dans le monde arabe a pris la forme d’une lutte populaire non-violente qui a triomphé d’abord en Tunisie, puis en Egypte. Mais pour mieux comprendre ce phénomène historique, on ne peut ignorer le précédent que représente la résistance non-violente en Palestine comme ce fut le cas avec la première Intifada de 1987 à 1993 avant que cette forme de résistance soit relancée à partir de 2005. Cette innovation politique oblige à repenser le rapport entre révolution et violence et à considérer le choix de la non-violence comme une nécessité politique et historique.
Insécurités alimentaires : les risques géopolitiques se précisent en Méditerranée
Authors: Abis Sébastien
Published: June 2011

Les pays arabes de la Méditerranée subissent plusieurs chocs simultanément : politique, économique, climatique et alimentaire. Tout est lié dans cette région du Monde qui semble connaitre les débuts d’une transition majeure de son histoire. Parmi les nombreux enjeux à relever, celui consistant à gérer les insécurités alimentaires s’amplifie. Bien qu’il ne soit pas nouveau, le problème prend une tonalité de plus en plus géostratégique dans une zone où notamment les ressources en eau et en sols se font rares. Le développement agricole est contrarié, tout comme l’accès à l’alimentation se complexifie. Il faut regarder attentivement cette fragilité alimentaire qui s’accroît parmi les risques majeurs auxquels la région devra faire face. Au même moment, c’est également la dérive des territoires, entre des villes littorales globalisées et des zones rurales enclavées, qui s’affiche comme l’une des failles majeures traversant ces pays et ces sociétés
Entre littérature, science et politique : les œuvres alchimiques de Thomas Norton et George Ripley
Authors: Mairey Aude
Published: June 2011

Résumé Les œuvres alchimiques de Thomas Norton (The Ordinal of Alchemy) et George Ripley (The Compound of Alchemy) constituent deux des plus importants témoignages de la popularité de l’alchimie dans l’Angleterre de la seconde moitié du xv e  siècle, mais elles n’ont généralement été étudiées que sous l’angle de leur pseudo- scientificité. Or, leurs auteurs abordent, particulièrement dans leurs prologues, des questions cruciales sur les notions de littérature, de langue et de connaissance, mais aussi sur leur rapport au pouvoir et au prince. Cela est d’autant plus notable qu’ils souhaitent transmettre une discipline à la croisée des sciences et des arts, marquée par la culture du secret. De fait, ces textes invitent à repenser tout autant les frontières établies entre cultures savantes et non savantes que celles entre les genres littéraires médiévaux. Ils participent pleinement à la constitution d’une culture laïque possédant une forte identité anglaise et marquée par des enjeux politiques essentiels – la transformation du prince aux fins de bon gouvernement – dans le contexte d’une société politique troublée par la guerre civile.
Le livre français en Italie à la fin du xixe siècle : problématiques et méthodes
Authors: Muller Raphaël
Published: June 2011

Résumé Entre 1880 et 1920, le livre français est présent en Italie sous différentes formes : en version originale, comme en traduction. Dans un pays dont les élites sont très majoritairement francophones, où la culture française est une référence constante, dans un pays aussi qui a récemment achevé son unité territoriale et s’est engagé dans un processus d’unification culturelle qui passe par un élargissement du lectorat, le livre est un vecteur majeur de la présence culturelle française. Cette présence peut être mesurée précisément grâce aux séries bibliographiques nationales mises en place à partir de 1885 pour recenser les ouvrages publiés en Italie et les ouvrages étrangers acquis par les bibliothèques italiennes. Dans un marché éditorial en pleine expansion, caractérisé par l’émergence de maisons de dimension nationale, la traduction de livres français, et tout particulièrement de romans populaires issus des feuilletons de la presse parisienne, est particulièrement active et constitue le vecteur majeur de la conquête de nouveaux publics, nés des progrès de l’alphabétisation. Largement présent dans les fonds, dans les bibliothèques publiques de la Péninsule, le livre en français est un support majeur de la diffusion des savoirs académiques, en particulier en matière de médecine, d’histoire ou de critique littéraire, alors que les ouvrages de philosophie ou de philologie étaient plus fréquemment importés d’Allemagne.
Surgical Outcomes of 23- and 20-Gauge Vitrectomies for Rhegmatogenous Retinal Detachment Associated With Posterior Vitreous Detachment
Authors: Hikichi Taiichi , Kosaka Shoko , Takami Kimitaka , Ariga Hiroko , Ohtsuka Hideo , Higuchi Makoto , Matsushita Takuro , Matsushita Reiko
Published: June 2011

BACKGROUND AND OBJECTIVE:

To compare the outcomes of 23- and 20-gauge vitrectomies 1 year after primary repair of rhegmatogenous retinal detachments (RRDs) associated with a posterior vitreous detachment (PVD).

PATIENTS AND METHODS:

One hundred seventy-five consecutive eyes were reviewed that had undergone 23- or 20-gauge vitrectomy for RRDs associated with PVD.

RESULTS:

Retinal reattachment during the year after the first vitrectomy occurred in 88 (91%) of 97 eyes in the 23-gauge group and 70 (90%) of 78 eyes in the 20-gauge group. All eyes in both groups achieved anatomic success after another procedure. The surgical time in the 23-gauge group was significantly (
P
= .03) shorter than in the 20-gauge group. No significant difference was found between the preoperative and postoperative visual acuities in both groups.

CONCLUSION:

Twenty-three–gauge vitrectomy can obtain anatomic and visual acuity results similar to those obtained with 20-gauge vitrectomy after primary repair of RRDs and may be a surgical option for treating the disorder.
Lightweight self-compacting concrete reinforced with fibres for slab rehabilitation
Authors: Klein N. S. , De la Fuente A. , Aguado A. , Masó D.
Published: June 2011

The slabs of some buildings in Barcelona are formed by unidirectional beams, with a ceramic arch in between, which are filled with broken pottery or construction waste. These structures often present problems such as displacement of the tiles arranged over it due to the lack of stiffness of the filling material. This supposes a risk to the user and could also cause durability problems. In order to rehabilitate it, a lightweight self-compacting concrete reinforced with fibres (HLACF) has been designed to be used as a filling material, improving the stiffness of the structure.
This paper presents a structural analysis of a standard case and the results of an experimental campaign. The concrete showed a density of 1665 kg/m3, a slump flow of 605 mm and a compressive strength of 22.3 MPa, at 28 days. These results are in agreement with the requirements, overcoming common lightweight concrete segregation problems.
El arca en el mobiliario de la Asturias preindustrial: piezas del concejo de Grado
Authors: Díaz Quirós Gerardo
Published: June 2011

Con la idea de contribuir al conocimiento del mobiliario en la Asturias preindustrial se estudia un conjunto de arcas del concejo asturiano de Grado. Previo repaso al papel jugado por esta tipología en el mobiliario asturiano y a sus características básicas, tanto estructurales como decorativas, se ofrece análisis más pormenorizado de una selección de piezas representativas.
Muebles virreinales oaxaqueños realizados en zumaque. La marquetería de Villa Alta
Authors: Corrales Juan Manuel
Published: June 2011

La región mexicana de Oaxaca, durante el periodo virreinal, fue un gran centro productor de muebles. De entre los diversos trabajos oaxaqueños destacan los realizados con una técnica particular de la zona serrana denominada, comúnmente, zumaque. Estas producciones realizadas en la Villa Alta de San Ildefonso, entre los siglos XVII al XIX, se limitan exclusivamente a ciertas tipologías de muebles civiles; escritorios, papeleras, escritorillos o arquillas de estrado, arcas, arquetas y cajas. Este artículo presenta la investigación más reciente y completa sobre el tema adentrándose en la problemática terminológica, los orígenes del centro productor, las diversas técnicas constructivas y decorativas empleadas así como el estudio analítico de sus maderas y la pasta de relleno.
“Dios nos mejore las horas si nos conviene”: La salud y la enfermedad de una familia montañesa del siglo XIX a través del estudio de las escrituras del yo
Authors: Rubalcaba Pérez Carmen
Published: June 2011

A partir del nacimiento, en los años setenta del siglo XX, de la denominada antropología de la salud y la enfermedad, se inició el reconocimiento de ambos estados como fenómenos culturales y los antropólogos comenzaron a sumergirse en la comprensión de la manera en que se elaboran los conceptos de sano y enfermo. La historia social de la cultura escrita, a través del estudio de los testimonios escritos del pasado, se constituye en un recurso insustituible para analizar las dimensiones sociales y culturales del proceso de enfermar en su dimensión histórica. A través del análisis de la documentación autógrafa de carácter privado —correspondencia y anotaciones personales en libros de cuentas— de un pequeño propietario rural acomodado, Pedro Jado Agüero (1815- 1891), se muestra cómo la enfermedad no consiste sólo en una disfunción biológica, sino también en una matriz de significados culturalmente establecidos que hay que intentar desentrañar. Descubrir el sentido simbólico de la enfermedad a través del análisis del conjunto de experiencias, de palabras y de sentimientos utilizados o descritos por los integrantes de una cultura significa acercarse en mayor medida al conocimiento de su estructura de significados.
La fortuna del mueble español en el mercado de arte como reflejo de su valoración social
Authors: Caruana Moyano Sonsoles
Published: June 2011

El mueble no comenzó a ser tratado en España como objeto de estudio científico —salvo honrosas excepciones— hasta la década de 1970. En ese momento irrumpe además en el panorama nacional una nueva forma de venta de arte, al margen de anticuarios y marchantes: las subastas, nacidas dos siglos atrás en Inglaterra. Así, lo académico y lo comercial se aúnan: publicaciones rigurosas, estudios concienzudos y catálogos de mobiliario, favorecen la aparición de nuevas piezas en muchas ocasiones a través del canal del mercado del arte, que, a su vez, nutren dichos estudios. Se aprende a valorar, en el sentido más amplio del término, el mobiliario. Lo que lleva a su conservación, su divulgación y también, por qué no, a establecer su valor pecuniario.
Simulations of the NK Cell Immune Synapse Reveal that Activation Thresholds Can Be Established by Inhibitory Receptors Acting Locally
Authors: Kaplan Asya , Kotzer Shulamit , Almeida Catarina R. , Kohen Refael , Halpert Gilad , Salmon-Divon Mali , Köhler Karsten , Höglund Petter , Davis Daniel M. , Mehr Ramit
Published: June 2011

NK cell activation is regulated by a balance between activating and inhibitory signals. To address the question of how these signals are spatially integrated, we created a computer simulation of activating and inhibitory NK cell immunological synapse (NKIS) assembly, implementing either a “quantity-based” inhibition model or a “distance-based” inhibition model. The simulations mimicked the observed molecule distributions in inhibitory and activating NKIS and yielded several new insights. First, the total signal is highly influenced by activating complex dissociation rates but not by adhesion and inhibitory complex dissociation rates. Second, concerted motion of receptors in clusters significantly accelerates NKIS maturation. Third, when the potential of a cis interaction between Ly49 receptors and MHC class I on murine NK cells was added to the model, the integrated signal as a function of receptor and ligand numbers was only slightly increased, at least up to the level of 50% cis-bound Ly49 receptors reached in the model. Fourth, and perhaps most importantly, the integrated signal behavior obtained when using the distance-based inhibition signal model was closer to the experimentally observed behavior, with an inhibition radius of the order 3–10 molecules. Microscopy to visualize Vav activation in NK cells on micropatterned surfaces of activating and inhibitory strips revealed that Vav is only locally activated where activating receptors are ligated within a single NK cell contact. Taken together, these data are consistent with a model in which inhibitory receptors act locally; that is, that every bound inhibitory receptor acts on activating receptors within a certain radius around it.
A Self-Reactive TCR Drives the Development of Foxp3+ Regulatory T Cells That Prevent Autoimmune Disease
Authors: Killebrew Justin R. , Perdue Nikole , Kwan Alan , Thornton Angela M. , Shevach Ethan M. , Campbell Daniel J.
Published: June 2011

Although Foxp3+ regulatory T cells (Tregs) are thought to express autoreactive TCRs, it is not clear how individual TCRs influence Treg development, phenotype, and function in vivo. We have generated TCR transgenic mice (termed SFZ70 mice) using Tcra and Tcrb genes cloned from an autoreactive CD4+ T cell isolated from a Treg-deficient scurfy mouse. The SFZ70 TCR recognizes a cutaneous autoantigen and drives development of both conventional CD4+ Foxp3− T cells (Tconv) and Foxp3+ Tregs. SFZ70 Tregs display an activated phenotype evidenced by robust proliferation and expression of skin-homing molecules such as CD103 and P-selectin ligand. Analysis of Foxp3-deficient SFZ70 mice demonstrates that Tregs inhibit Tconv cell expression of tissue-homing receptors and their production of proinflammatory cytokines. In addition, Treg suppression of SFZ70 Tconv cells can be overcome by nonspecific activation of APCs. These results provide new insights into the differentiation and function of tissue-specific Tregs in vivo and provide a tractable system for analyzing the molecular requirements of Treg-mediated tolerance toward a cutaneous autoantigen.
Thyroid Hormone Action in Cerebellum and Cerebral Cortex Development
Authors: Chatonnet Fabrice , Picou Frédéric , Fauquier Teddy , Flamant Frédéric
Published: June 2011

Thyroid hormones (TH, including the prohormone thyroxine (T4) and its active deiodinated derivative 3,,5-triiodo-L-thyronine (T3)) are important regulators of vertebrates neurodevelopment. Specific transporters and deiodinases are required to ensure T3 access to the developing brain. T3 activates a number of differentiation processes in neuronal and glial cell types by binding to nuclear receptors, acting directly on transcription. Only few T3 target genes are currently known. Deeper investigations are urgently needed, considering that some chemicals present in food are believed to interfere with T3 signaling with putative neurotoxic consequences.
Simple Electrochemical Determination of Surface-Active Substances in Natural Waters
Authors: Cvrković-Karloci Željka , Krznarić Damir , Šeruga Marijan , Ćosović Božena
Published: June 2011

A simple electrochemical determination of surface-active substances by using time-dependent variation of the capacitive current in a.c. voltammetry at the HMDE is described. Surface-active substances were accumulated by stirring solution at the deposition potential of −0.6 V versus Ag/AgCl (sat. NaCl). The capacitive current was recorded for different deposition times in the range 0–120 s, wherefrom the linear calibration plot is constructed. The proposed method was verified for model surfactant TritonX-100 in the concentration range 0.02–0.25 mg/L and for humic acid in the concentration range 1.65–20 mg/L. The application of the method was demonstrated for freshwater samples of the Drava river, Danube river, and the wetland Kopački Rit, Croatia. The shape of theiac-Ecurves as well as the obtained concentrations of surface-active substances by using humic acid as the calibration substance are quite well describing the type and the nature of organic matter in the freshwater samples.
Anodic Determination of Acetylsalicylic Acid at a Mildly Oxidized Boron-Doped Diamond Electrode in Sodium Sulphate Medium
Authors: Cofan Codruţa , Radovan Ciprian
Published: June 2011

Differential pulse voltammetry (DPV) and chronoamperometry (CA) were used to detect and determine acetylsalicylic acid (ASA) at a mildly oxidized boron-doped diamond (BDD) electrode in a neutral sodium sulphate solution as supporting electrolyte. ASA determination in unbuffered medium was achieved using neutralized standard and real samples. Over the concentration range of 0.01 mM–0.1 mM, linear calibration plots of anodic current peaks in DPV and anodic currents in CA experiments versus concentration were obtained with very high correlation coefficients and good sensitivity values. The limits of detection were situated around 1 μM. The association of DPV and CA techniques with standard addition method represented a suitable option for the determination of ASA in real samples such as pharmaceutical formulations.
Stabilization of a G-Quadruplex from Unfolding by Replication Protein A Using Potassium and the Porphyrin TMPyP4
Authors: Prakash Aishwarya , Kieken Fabien , Marky Luis A. , Borgstahl Gloria E. O.
Published: June 2011

Replication protein A (RPA) plays an essential role in DNA replication by binding and unfolding non-canonical single-stranded DNA (ssDNA) structures. Of the six RPA ssDNA binding domains (labeled A-F), RPA-CDE selectively binds a G-quadruplex forming sequence (5′-TAGGGGAAGGGTTGGAGTGGGTT-3′called Gq23). In K+, Gq23 forms a mixed parallel/antiparallel conformation, and in Na+Gq23 has a less stable (TMlowered by ∼20∘C), antiparallel conformation. Gq23 is intramolecular and 1D NMR confirms a stable G-quadruplex structure in K+. Full-length RPA and RPA-CDE-core can bind and unfold the Na+form of Gq23 very efficiently, but complete unfolding is not observed with the K+form. Studies with G-quadruplex ligands, indicate that TMPyP4 has a thermal stabilization effect on Gq23 in K+, and inhibits complete unfolding by RPA and RPA-CDE-core. Overall these data indicate that G-quadruplexes present a unique problem for RPA to unfold and ligands, such as TMPyP4, could possibly hinder DNA replication by blocking unfolding by RPA.
Breast Tumor Angiogenesis and Tumor-Associated Macrophages: Histopathologist's Perspective
Authors: Ch'ng Ewe Seng , Jaafar Hasnan , Tuan Sharif Sharifah Emilia
Published: June 2011

Much progress has been made since the conceptualization of tumor angiogenesis—the induction of growth of new blood vessels by tumor—as a salient feature of clinically significant primary or metastatic cancers. From a practicing histopathologist's point of view, we appraise the application of this concept in breast cancer with particular reference to the evaluation of proangiogenic factors and the assessment of new microvessels in histopathological examination. Recently, much focus has also been centered on the active roles played by tumor-associated macrophages in relation to tumor angiogenesis. We review the literature; many data supporting this facet of tumor angiogenesis were derived from the breast cancer models. We scrutinize the large body of clinical evidence exploring the link between the tumor-associated macrophages and breast tumor angiogenesis and discuss particularly the methodology and limitations of incorporating such an assessment in histopathological examination.
Characterization of Anthraquinone-DerivedRedox Switchable Ionophores and Their Complexes with Li+, Na+, K+, Ca+, and Mg+Metal Ions
Authors: Vyas Vaishali , Raizada Pankaj , Sharma Uma
Published: June 2011

Anthraquinone derived redox switchable ionophores 1,5 bis (2-(2-(2-ethoxy) ethoxy) ethoxy)anthracene-9,10-dione (V1) and 1,8-bis(2-(2-(2-ethoxy)ethoxy)ethoxy) anthracene—9,10-dione (V2) have been used for isolation, extraction and liquid membrane transport studies of Li+, Na+, K+, Ca2+and Mg2+metal ions. These isolated complexes were characterized by melting point determination, CV and IR,1H NMR spectral analysis. Ionophore V2shows maximum shift in reduction potential(ΔE)with Ca(Pic)2. The observed sequence for the shifting in reduction potential(ΔE)between V2and their complexes is V2calcium picrate (42 mV) > V2potassium picrate (33 mV) > V2lithium picrate (25 mV) > V2sodium picrate (18 mV) > V2magnesium picrate (15 mV). These findings are also supported by results of extraction, back extraction and transport studies. Ionophore V2complexed with KPic and showed much higher extractability and selectivity towards K+than V1. These synthetic ionophores show positive and negative cooperativity towards alkali and alkaline earth metal ions in reduced and oxidized state. Hence, this property can be used in selective separation and enrichment of metal ions using electrochemically driven ion transport.
Electrochemical Sensor for Determination of Parathion Based on Electropolymerization Poly(Safranine) Film Electrode
Authors: Liu Xingyuan
Published: June 2011

Parathion has been determined with voltammetric technique based on a novel sensor fabricated by electropolymerization of safranine on a glassy carbon electrode (GCE). The electrochemical behavior of poly(safranine) film electrode and its electrocatalytic activity toward parathion were studied in detail by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). All experimental parameters were optimized, and LSV was proposed for its determination. In optimal working conditions, the reduction current of parathion at this poly(safranine)-modified electrode exhibited a good linear relationship with parathion concentration in the range of3.43×10−8to3.43×10−5 molL−1. The detection limit was1.0×10−8 molL−1. The high sensitivity and selectivity of the sensor were demonstrated by its practical application for the determination of trace amounts of parathion in fruit samples.
Sediment provenance and diagenesis, Lower Cretaceous of the Alma K-85 well, Scotian Shelf
Authors: Pe-Piper G , Piper D J W , Lefort D , Ledger-Piercey S
Published: June 2011

Eight conventional cores from the Alma K-85 well have been logged and sampled. They represent the Albian Cree Member of the Logan Canyon Formation and the predominantly Barremian Upper Member of the Missisauga Formation. Compared with other wells in the
southwestern Sable sub-basin, prodeltaic turbidites are rare and sediments comprise principally shoreface sandstones and open shelf mudstones. The Upper Missisauga interval accumulated on a prodelta slope and almost all sandstones are part of slide blocks 10-15 m thick.
Detrital petrology is strikingly different from that of the Abenaki sub-basin, as represented by the Peskowesk A-99 well. The sandstones at Alma are principally quartz arenites, in contrast to sublitharenites at Peskowesk. At Alma, the predominant feldspar is plagioclase and lithic clasts from
metamorphic and sedimentary sources are more abundant than at Peskowesk, which appears to have a predominantly felsic igneous source with abundant Kfeldspar. A substantial component of the sediment at Alma has a polycyclic source, probably from Carboniferous or Lower Paleozoic sandstones, resulting
in the concentration of resistant heavy minerals such as chromite/spinel and zircon, and perhaps tourmaline and garnet. Nevertheless, the dominant chemical types of garnet, tourmaline, detrital chlorite and igneous muscovite are all consistent with sources in the Meguma terrane.
Spinel/chromite, tourmaline and plagioclase all show little change in abundance with depth, suggesting that the source of sediment remained approximately the same throughout the sampled interval. In contrast, garnet appears to become diagenetically unstable at depth and less K-feldspar appears to
have been supplied.
The paragenetic sequence of diagenetic minerals is similar to that found elsewhere in the southwestern Sable sub-basin, with some early kaolinite and important early and late Fe-calcite cements. However, Fe-silicate minerals resulting from suboxic reduction of Fe, characteristic of brackish water
and low organic carbon, are very rare, and even siderite is uncommon. These observations reflect the dominance of fully marine (shoreface and open shelf) lithofacies, and accounts for the absence of chlorite rims on quartz grains. The lack of late ankerite cement may also be related to the relative
paucity of siderite.
Geothermal energy resource potential of Canada
Authors: Grasby S E , Allen D M , Bell S , Chen Z , Ferguson G , Jessop A , Kelman M , Ko M , Majorowicz J , Moore M , Raymond J , Therrien R
Published: June 2011

Canada has enormous geothermal energy resources that could supply a renewable and clean source of power. There are many constraints, however, in utilizing this energy resource, including geological, technical, and regulatory issues. The intent of this report is
to examine the geothermal potential in Canada, and the geological controls on the distribution of high grade resources as well as controls on the economic development and production of geothermal energy. This assessment is based on a new compilation and digitization of data produced through over 48
years of geothermal research in Canada. Recommendations on current and future research needs to reduce barriers to resource production are made at the end of the report.
Currently Canada has no geothermal electrical production; however, direct use and heat exchange systems are used widely. Several projects are currently being examined by industry and government to develop electrical potential in Canada. A key economic constraint for these projects is the high risk
of exploration due to costs of deep drilling. The cost of delivered geothermal power is projected to decline and be competitive with coal fired production within the next 15 years, given current levels of technology.
Canada's in-place geothermal power exceeds one million times Canada's current electrical consumption (Fig. 1). However, only a fraction of this total potential could be developed. Much of the resource lies beyond current drilling technology, outside of areas served by high-capacity transmission
lines, and at some distance from load centres. Nonetheless, the available high grade geothermal resource is considerable. High temperature hydrothermal systems can be brought on line with proven technology. Many of the tools required to bring geothermal energy to full realization, however, are not
commercially proven to date and require further research and technology development. We can expect a strong learning curve and price response as geothermal energy is developed while other energy sources such as coal and nuclear will begin to see fleet and capacity
retirements.
Communicating Tubular Duplication of Upper Esophagus–A Rare Occurrence
Authors: Rathod Jawahar , Disawal Amit , Taori Kishor , Agrawal Meenakshi , Gaur Prajwaleet P , Jadhav Vijay , Prasad Krishna , Wankhede Kanchan
Published: June 2011

Duplications of esophagus are commonly classified into two types, tubular and cystic. Tubular duplication of esophagus is a rare occurrence and is much less common than cystic duplication of foregut. Most esophageal duplications are located in the lower third of the esophagus. A cervical esophageal duplication is extremely rare. Esophageal duplications have been reported twice as commonly on the right as on the left. We report a case of incidental finding identified on computed tomography of communicating tubular esophageal duplication involving the left side of the upper esophagus in a tuberculosis patient that was subsequently confirmed on barium swallow test.
S3-covers of Schemes
Authors: Easton Robert W.
Published: June 2011

We analyze flat S3-covers of schemes, attempting to create structures parallel to those found in the abelian and triple cover theories. We use an initial local analysis as a guide in finding a global description.
Phase transitions of wax esters adjust buoyancy in diapausing Calanoides acutus
Authors: Pond David W. , Tarling Geraint A.
Published: June 2011

We study the composition and biophysical properties of wax esters extracted from the Antarctic copepod, Calanoides acutus, to explore if these factors adjust buoyancy in diapausing copepods. Levels of wax ester in the copepods were correlated with depth, with deeper animals containing higher amounts. An unsaturation index was used to determine the proportions of polyunsaturated wax esters in the oil sac of the copepods. The proportion of polyunsaturated wax ester in copepods that had descended to depth was always close to 50% and attributable to high amounts of the diatom biomarker fatty acid 20:5(n‐3) contained in these storage lipids. High‐pressure differential scanning calorimetry indicated that wax esters with such high levels of unsaturation exhibited unusual properties, changing from a liquid to a solid phase at pressures and temperatures below 500 m in the ocean. The dense, solid wax esters reduce the overall buoyancy of the lipid‐rich copepods at depth and help facilitate neutral buoyancy. The composition of wax esters is a key factor in buoyancy control in these organisms during diapause.
Phosphorus loading of mountain lakes: Terrestrial export and atmospheric deposition
Authors: Kopàček Jiří , Hejzlar Josef , Vrba Jaroslav , Stuchlík Evžen
Published: June 2011

We studied the atmospheric deposition of phosphorus (P) forms along an elevation gradient, and its contribution to the total external P loading of lakes in the Tatra Mountains and the Bohemian Forest, from 1998 to 2009. The aim was to evaluate how topographical (soil and vegetation pools in the catchment) and morphological (catchment‐to‐lake area ratio) characteristics of catchment–lake systems affect in‐lake nutrient structures in remote mountain areas. Concentrations of dissolved organic carbon (DOC), total phosphorus (TP), and total organic nitrogen (TON) were closely related (p < 0.001) to each other in lakes and their inlets. Terrestrial TP export (57–1183 μmol m−2 yr−1 on a catchment area basis) and lake‐water TP concentrations (0.05–1.0 μmol L−1) were closely associated with DOC leaching, exhibiting significant (p < 0.001) exponential relationships with increasing soil cover in the catchments. Precipitation fluxes of TP (460–918 μmol m−2 yr−1, average 692 μmol m−2 yr−1, with 50% being soluble reactive P) increased with precipitation along the elevation gradient and were highest in windy mountain areas. The C : N and C : P ratios of external nutrient inputs to the lakes were higher for terrestrial than atmospheric sources by a factor of ∼ 4 and 32, respectively, and the relative atmospheric contribution to the total external P loading of lakes was inversely related to the soil cover of catchments and the ratio between catchment and lake areas. The different composition and proportion of terrestrial and atmospheric nutrient inputs to mountain lakes along the vegetation zones determine the stoichiometric balance between the DOC and P available as nutrients for the food webs of natural mountain lakes.
Correcting orbital drift signal in the time series of AVHRR derived convective cloud fraction using rotated empirical orthogonal function
Authors: Devasthale A. , Karlsson K. , Quaas J. , Grassl H.
Published: June 2011

Abstract. The AVHRRs instruments onboard the series of NOAA satellites offer the longest available meteorological data records from space. These satellites have drifted in orbit resulting in shifts in the local time sampling during the life span of sensors onboard. Depending on the amplitude of a diurnal cycle of the geophysical parameters derived, orbital drift may cause spurious trends in their time series. We investigate tropical deep convective clouds, which show pronounced diurnal cycle amplitude, to bracket an upper bound of the impact of orbital drift on their time series. We carry out a rotated empirical orthogonal function analysis and show that the REOFs are useful in delineating orbital drift signal and, more importantly, in correcting this signal in the time series of convective cloud amount. These results will help facilitate the derivation of homogenized data series of cloud amount from NOAA satellite sensors and ultimately analyzing trends from them. However, we suggest detailed comparison of various methods and their rigorous testing before applying final orbital drift corrections.
A systematic approach for comparing modeled biospheric carbon fluxes across regional scales
Authors: Huntzinger D. N. , Gourdji S. M. , Mueller K. L. , Michalak A. M.
Published: June 2011

Abstract. Given the large differences between biospheric model estimates of regional carbon exchange, there is a need to understand and reconcile the predicted spatial variability of fluxes across models. This paper presents a set of quantitative tools that can be applied to systematically compare flux estimates despite the inherent differences in model formulation. The presented methods include variogram analysis, variable selection, and geostatistical regression. These methods are evaluated in terms of their ability to assess and identify differences in spatial variability in flux estimates across North America among a small subset of models, as well as differences in the environmental drivers that best explain the spatial variability of predicted fluxes. The examined models are the Simple Biosphere (SiB 3.0), Carnegie Ames Stanford Approach (CASA), and CASA coupled with the Global Fire Emissions Database (CASA GFEDv2), and the analyses are performed on model-predicted net ecosystem exchange, gross primary production, and ecosystem respiration. Variogram analysis reveals consistent seasonal differences in spatial variability among modeled fluxes at a 1° × 1° spatial resolution. However, significant differences are observed in the overall magnitude of the carbon flux spatial variability across models, in both net ecosystem exchange and component fluxes. Results of the variable selection and geostatistical regression analyses suggest fundamental differences between the models in terms of the factors that explain the spatial variability of predicted flux. For example, carbon flux is more strongly correlated with percent land cover in CASA GFEDv2 than in SiB or CASA. Some of the differences in spatial patterns of estimated flux can be linked back to differences in model formulation, and would have been difficult to identify simply by comparing net fluxes between models. Overall, the systematic approach presented here provides a set of tools for comparing predicted grid-scale fluxes across models, a task that has historically been difficult unless standardized forcing data were prescribed, or a detailed sensitivity analysis performed.
Carbon dioxide fluxes over an ancient broadleaved deciduous woodland in southern England
Authors: Thomas M. V. , Malhi Y. , Fenn K. M. , Fisher J. B. , Morecroft M. D. , Lloyd C. R. , Taylor M. E. , McNeil D. D.
Published: June 2011

Abstract. We present results from a study of canopy-atmosphere fluxes of carbon dioxide from 2007 to 2009 above a site in Wytham Woods, an ancient temperate broadleaved deciduous forest in southern England. Gap-filled net ecosystem exchange (NEE) data were partitioned into gross primary productivity (GPP) and ecosystem respiration (Re) and analysed on daily, monthly and annual timescales. Over the continuous 24 month study period annual GPP was estimated to be 21.1 Mg C ha−1 yr−1 and Re to be 19.8 Mg C ha−1 yr−1; net ecosystem productivity (NEP) was 1.2 Mg C ha−1 yr−1. These estimates were compared with independent bottom-up estimates derived from net primary productivity (NPP) and flux chamber measurements recorded at a plot within the flux footprint in 2008 (GPP = 26.5 ± 6.8 Mg C ha−1 yr−1, Re = 24.8 ± 6.8 Mg C ha−1 yr−1, biomass increment = ~1.7 Mg C ha−1 yr−1). Over the two years the difference in seasonal NEP was predominantly caused by changes in ecosystem respiration, whereas GPP remained similar for equivalent months in different years. Although solar radiation was the largest influence on daily values of CO2 fluxes (R2 = 0.53 for the summer months for a linear regression), variation in Re appeared to be driven by temperature. Our findings suggest that this ancient woodland site is currently a substantial sink for carbon, resulting from continued growth that is probably a legacy of past management practices abandoned over 40 years ago. Our GPP and Re values are generally higher than other broadleaved temperate deciduous woodlands and may represent the influence of the UK's maritime climate, or the particular species composition of this site. The carbon sink value of Wytham Woods supports the protection and management of temperate deciduous woodlands (including those managed for conservation rather than silvicultural objectives) as a strategy to mitigate atmospheric carbon dioxide increases.
Impacts of UV radiation on plankton community metabolism along the Humboldt Current System
Authors: Godoy N. , Canepa A. , Lasternas S. , Mayol E. , Ruíz-Halpern S. , Agustí S. , Castilla J. C. , Duarte C. M.
Published: June 2011

Abstract. The Humbolt Current System along the Chilean coast is one of the most productive regions in the world, where UV levels are particularly high due to stratospheric ozone depletion. Research has shown that phytoplankton photosynthesis can be severely inhibited by surface radiation and there are concerns that this will reduce not only algal carbon fixation, but also the carbon supply for higher trophic level. Experimental estimates of community metabolism (NCP, GPP and R) and the impacts of UV on community metabolism were assessed at 8 stations along the meridional track by the Humbold-2009 cruise (54.80° S–23.85° S) on board RV Hespérides from 5 to 15 March 2009. The results showed an increase UVB penetration towards the Equator, along the Humboldt Current System, suggesting a more important impact of UVB radiation towards the north. The metabolic rates observed were within average values reported for the Ocean Pacific and did not show the water mass investigated to be exceptionally productive at the time of the study. Experimental evaluation of the effect of UVB radiation on surface waters, those most strongly affected by UVB, showed that UVB radiation suppressed net community production, resulting in a dominance of heterotrophic communities in surface waters, compared to the prevalence of autotrophic communities inferred when materials, excluding UVB radiation, are used for incubation. These results show that UVB radiation, which has increased greatly in the study area, may have suppressed net community production of the plankton communities, possibly driving plankton communities in the Southwest Pacific towards CO2 sources.
The 1-way on-line coupled atmospheric chemistry model system MECO(n) – Part 1: The limited-area atmospheric chemistry model COSMO/MESSy
Authors: Kerkweg A. , Jöckel P.
Published: June 2011

Abstract. The numerical weather prediction model of the Consortium for Small Scale Modelling (COSMO), maintained by the German weather service (DWD), is connected with the Modular Earth Submodel System (MESSy). This effort is undertaken in preparation of a~new, limited-area atmospheric chemistry model. This model is as consistent as possible, with respect to atmospheric chemistry and related processes, with a previously developed global atmospheric chemistry general circulation model: the ECHAM/MESSy Atmospheric Chemistry (EMAC) model. The combined system constitutes a new research tool, bridging the global to the meso-γ scale for atmospheric chemistry research. MESSy provides the infrastructure and includes, among others, the process and diagnostic submodels for atmospheric chemistry simulations. Furthermore, MESSy is highly flexible allowing model setups with tailor made complexity, depending on the scientific question. Here, the connection of the MESSy infrastructure to the COSMO model is documented. Previously published prototype submodels for simplified tracer studies are generalised to be plugged-in and used in the global and the limited-area model. They are used to evaluate the tracer transport characteristics of the new COSMO/MESSy model system, an important prerequisite for future atmospheric chemistry applications. A supplementary document with further details on the technical implementation of the MESSy interface into COSMO with a complete list of modifications to the COSMO code is provided.
The influence of constrained fossil fuel emissions scenarios on climate and water resource projections
Authors: Ward J. D. , Werner A. D. , Nel W. P. , Beecham S.
Published: June 2011

Abstract. Water resources planning requires long-term projections of the impact of climate change on freshwater resources. In addition to intrinsic uncertainty associated with the natural climate, projections of climate change are subject to the combined uncertainties associated with selection of emissions scenarios, GCM ensembles and downscaling techniques. In particular, unknown future greenhouse gas emissions contribute substantially to the overall uncertainty. We contend that a reduction in uncertainty is possible by refining emissions scenarios. We present a comprehensive review of the growing body of literature that challenges the assumptions underlying the high-growth emissions scenarios (widely used in climate change impact studies), and instead points to a peak and decline in fossil fuel production occurring in the 21st century. We find that the IPCC's new RCP 4.5 scenario (low-medium emissions), as well as the B1 and A1T (low emissions) marker scenarios from the IPCC's Special Report on Emissions Scenarios are broadly consistent with the majority of recent fossil fuel production forecasts, whereas the medium to high emissions scenarios generally depend upon unrealistic assumptions of future fossil fuel production. We use a simple case study of projected climate change in 2070 for the Scott Creek catchment in South Australia to demonstrate that even with the current suite of climate models, by limiting projections to the B1 scenario, both the median change and the spread of model results are reduced relative to equivalent projections under an unrealistic high emissions scenario (A1FI).
Downscaling of surface moisture flux and precipitation in the Ebro Valley (Spain) using analogues and analogues followed by random forests and multiple linear regression
Authors: Ibarra-Berastegi G. , Saénz J. , Ezcurra A. , Elías A. , Diaz Argandoña J. , Errasti I.
Published: June 2011

Abstract. In this paper, reanalysis fields from the ECMWF have been statistically downscaled to predict from large-scale atmospheric fields, surface moisture flux and daily precipitation at two observatories (Zaragoza and Tortosa, Ebro Valley, Spain) during the 1961–2001 period. Three types of downscaling models have been built: (i) analogues, (ii) analogues followed by random forests and (iii) analogues followed by multiple linear regression. The inputs consist of data (predictor fields) taken from the ERA-40 reanalysis. The predicted fields are precipitation and surface moisture flux as measured at the two observatories. With the aim to reduce the dimensionality of the problem, the ERA-40 fields have been decomposed using empirical orthogonal functions. Available daily data has been divided into two parts: a training period used to find a group of about 300 analogues to build the downscaling model (1961–1996) and a test period (1997–2001), where models' performance has been assessed using independent data. In the case of surface moisture flux, the models based on analogues followed by random forests do not clearly outperform those built on analogues plus multiple linear regression, while simple averages calculated from the nearest analogues found in the training period, yielded only slightly worse results. In the case of precipitation, the three types of model performed equally. These results suggest that most of the models' downscaling capabilities can be attributed to the analogues-calculation stage.
Spatial moments of catchment rainfall: rainfall spatial organisation, basin morphology, and flood response
Authors: Zoccatelli D. , Borga M. , Viglione A. , Chirico G. B. , Blöschl G.
Published: June 2011

Abstract. This paper provides a general analytical framework for assessing the dependence existing between spatial rainfall organisation, basin morphology and runoff response. The analytical framework builds upon a set of spatial rainfall statistics (termed "spatial moments of catchment rainfall") which describe the spatial rainfall organisation in terms of concentration and dispersion statistics as a function of the distance measured along the flow routing coordinate. The introduction of these statistics permits derivation of a simple relationship for the quantification of storm velocity at the catchment scale. The paper illustrates the development of the analytical framework and explains the conceptual meaning of the statistics by means of application to five extreme flash floods occurred in various European regions in the period 2002–2007. High resolution radar rainfall fields and a distributed hydrologic model are employed to examine how effective are these statistics in describing the degree of spatial rainfall organisation which is important for runoff modelling. This is obtained by quantifying the effects of neglecting the spatial rainfall variability on flood modelling, with a focus on runoff timing. The size of the study catchments ranges between 36 to 982 km2. The analysis reported here shows that the spatial moments of catchment rainfall can be effectively employed to isolate and describe the features of rainfall spatial organization which have significant impact on runoff simulation. These statistics provide essential information on what space-time scales rainfall has to be monitored, given certain catchment and flood characteristics, and what are the effects of space-time aggregation on flood response modeling.
The importance of parameter resampling for soil moisture data assimilation into hydrologic models using the particle filter
Authors: Plaza D. A. , De Keyser R. , De Lannoy G. J. M. , Giustarini L. , Matgen P. , Pauwels V. R. N.
Published: June 2011

Abstract. The Ensemble Kalman filter (EnKF) and the Sequential Importance Resampling (SIR) particle filter are evaluated for their performance in soil moisture assimilation and the consequent effect on discharge. With respect to the resulting soil moisture time series, both filters perform similarly. However, both filters have a negative effect on the discharge due to inconsistency between the parameter values and the states after the assimilation. In order to overcome this inconsistency, parameter resampling is applied along with the SIR filter, to obtain consistent parameter values with the analyzed soil moisture state. Extreme parameter replication, which could lead to a particle collapse, is avoided by the perturbation of the parameters with white noise. Both the modelled soil moisture and discharge are improved if the complementary parameter resampling is applied. The SIR filter with parameter resampling offers an efficient way to deal with biased observations. The robustness of the methodology is evaluated for 3 model parameter sets and 3 assimilation frequencies. Overall, the results in this paper indicate that the particle filter is a promising tool for hydrologic modelling purposes, but that an additional parameter resampling may be necessary to consistently update all state variables and fluxes within the model.