bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical Properties and Biocompatibility of Oligochitosan Membrane Film as Wound Dressing
Authors: Ujang Zanariah , Rashid Ahmad Hazri Abdul , Suboh Siti Kasmarizawaty , Halim Ahmad Sukari , Lim Chin Keong
Published: July 2015

Background

The physical and biological characteristics of oligochitosan (O-C) film, including its barrier and mechanical properties, in vitro cytotoxicity and in vivo biocompatibility, were studied to assess its potential use as a wound dressing.

Methods

Membrane films were prepared from water-soluble O-C solution blended with various concentrations of glycerol to modify the physical properties of the films. In vitro and in vivo biocompatibility evaluations were performed using primary human skin fibroblast cultures and subcutaneous implantation in a rat model, respectively.

Results

Addition of glycerol significantly influenced the barrier and mechanical properties of the films. Water absorption capacity was in the range of 80%-160%, whereas water vapor transmission rate varied from 1,180 to 1,618 g/m2 per day. Both properties increased with increasing glycerol concentration. Tensile strength decreased while elongation at break increased with the addition of glycerol. O-C films were found to be noncytotoxic to human fibroblast cultures and histological examination proved that films are biocompatible.

Conclusion

These results indicate that the membrane film from O-C has potential application as a wound-dressing material.
Association of Various Point Mutations as Risk Factors for Synthetic Graft Thrombosis in African American Hemodialysis Patients
Authors: Latif S. , Zaman F. , Nordberg M. , Abreo K.
Published: July 2015

Single-nucleotide polymorphisms in the genes that code for coagulation factor V (factor V (Leiden)) and II (prothrombin G20210A), as well as the methyltetrahydrofolate reductase (MTHFR) have been implicated in the majority of cases of hereditary thrombophilia. In our hemodialysis patient population, comprised mainly of African Americans, we have seen a high incidence of early vascular access thrombosis without any identifiable predisposing factors. In some instances, there is recurrent access thrombosis that may be related to an inherited condition. In this study we evaluated the presence of these gene mutations and their association with increased risk of recurrent vascular access thrombosis in our hemodialysis patient population. Our results show that factor V Leiden and factor II prothrombin point mutations did not appear to increase the risk of vascular access thrombosis in African Americans with end-stage renal disease on hemodialysis. Patients heterozygous for the MTHFR gene, also did not show a significant increased risk for synthetic graft thrombosis.
Arteriovenous access for Hemodialysis: Preoperative Assessment and Planning
Authors: Okada Soichi , Shenoy Surendra
Published: July 2015

Longevity in end-stage renal disease (ESRD) is dependent on adequacy of renal replacement therapy. Over 85% of the global ESRD population is hemodialysis dependent. Preoperative evaluation is the cornerstone of vascular access planning. The goal of preoperative evaluation is to design a sequence of options that can be used to provide vascular access throughout the life span of an ESRD patient. The intention should be to provide a durable vascular access in a timely fashion that needs few interventions, while refraining from jeopardizing future needs.
Changes in the physiological activity of soybean (Glycine max L. Merr.) under the influence of exogenous growth regulators
Authors: Nowak Anna , Wróbel Jacek
Published: July 2015

In a two-year pot experiment (2008–2009) conducted at the Vegetation Hall, West Pomeranian University of Technology in Szczecin, we investigated the influence of exogenous growth regulators, i.e. indole-3-butyric acid (IBA) and 6-benzylaminopurine (BAP) and their mixture, on the activity of gas exchange and selected physiological features of soybeans (Glycine max L. Merr.). The experimental factors included the following Polish soybean cultivars: ‘Aldana’, ‘Progres’ and ‘Jutro’. During plant growth, CO2 assimilation (A), transpiration rate (E), stomatal conductance (gs), and substomatal CO2 concentration (ci) were determined. Two soybean cultivars, i.e. ‘Jutro’ and ‘Progres’, showed a significant increase in the intensity of assimilation and transpiration after using all kinds of growth regulators as compared with the control plants. It was found that the ‘Jutro’ cultivar, after using a mixture of growth regulators (IBA + BAP), was characterized by the significantly highest CO2 assimilation (A) and transpiration (E) as well as the highest stomatal conductance (gs). The ‘Aldana’ cultivar, on the other hand, responded by a significant reduction in the transpiration rate, stomatal conductance and subsomatal CO2 concentration. The spraying of the plants with exogenous growth regulators had a significant influence on the increase in the number of stomata and stomatal pore length, mostly on the lower epidermis of the lamina. It was also found that plants from the ‘Jutro’ and ‘Aldana’ cultivars sprayed with IBA and IBA + BAP were characterized by the highest yield, as compared with the control plants. In the case of the ‘Jutro’ cultivar, after using the growth regulators, a positive correlation was observed between the assimilation and transpiration rates and the length of stomata, which in consequence produced increased yields.
Effect of different sucrose and nitrogen salt levels in the medium and temperature on in vitro propagation of Helleborus niger L.
Authors: Gabryszewska Eleonora Anna
Published: July 2015

Helleborus niger L. is a rhizomatous, herbaceous perennial with overwintering, divided, basal leaves. The objective of the study was to investigate the influence of different levels of sucrose (10, 20, 30, 40, 50, 60, 70, and 80 g l−1) and nitrogen salts (25%, 50%, and 100% according to MS medium) as well as temperature (15°C, 20°C) on in vitro multiplication and rooting and ex vitro acclimatization of H. niger. The growth and multiplication of axillary shoots were performed on modified MS medium supplemented with various growth regulators (2iP, BAP and kinetin – each at a concentration of 1.0 mg l−1, GA3 2.5 mg l−1). For the induction of roots, the medium was supplemented with IBA 1 mg l−1 and NAA 0.1 mg l−1. Rooted plants were transplanted in a peat–perlite substrate (4:1) in a heated greenhouse for ex vitro acclimatization. The multiplication rate of H. niger shoots, in vitro rooting, and ex vitro acclimatization were strongly dependent on the sucrose/nitrogen salt relationship in the medium. The highest multiplication rate of axillary shoots (3.7) was found at a temperature of 15°C or 20°C, on the medium with cytokinins and GA3 supplemented with sucrose 20–30 g l−1 and nitrogen salts at 50%. Sucrose at a concentration of 50 g l−1 strongly stimulated the number of roots per microplant (5.8–6.0) on the media with a reduced level of nitrogen salts (25% and 50%) when the temperatures were 20°C and 15°C, respectively. The plants rooted on the media with a high sucrose/nitrogen salt ratio showed acclimatization rates which ranged from 82% to 100%. Morphological observation of plantlets revealed obvious differences in leaf shape and size and the architecture of the root system as well as differences in the developmental stages of shoots grown on media with different sucrose and nitrogen salt concentrations.
Floristic diversity and agricultural value of Phalaridetum arundinaceae (Koch 1926 n.n.) Lib. 1931 in the selected river valleys of the Zamość region
Authors: Wyłupek Teresa Grażyna , Ziemińska-Smyk Marta , Czarnecki Zbigniew
Published: July 2015

The study presents the results of a floristic survey conducted using the Braun-Blanquet method (50 phytosociological relevés) in permanent grasslands in three river valleys of the Zamość region (Por, Huczwa, Wieprz). The goal of the survey was to determine the floristic diversity and fodder value of the Phalaridetum arundinaceae association (Koch 1926 n.n.) Lib. 1931. 

A total of 93 plant species from 25 botanical families were identified in the areas under study. The species richness of the Phalaridetum arundinaceae differed among river valleys. It was observed that these are often transitional forms similar to the association of the Molinio-Arrhenatheretea class, Molinietalia order. Predominance of hemicryptophytes and a relatively large share of geophytes was recorded. Based on the fodder value score calculated for the dry matter of the association, the community under study can be classified as having a medium or poor nutritional value.
Occurrence and differentiation of Arnoserido-Scleranthetum (Chouard 1925) in the Południowopodlaska Lowland
Authors: Rzymowska Zofia , Skrajna Teresa , Skrzyczyńska Janina
Published: July 2015

The paper presents Arnoserido-Scleranthetum phytocoenoses at the eastern and north-eastern peripheries of their occurrence range and the results of a field study conducted in the Południowopolska Lowland in 1990–2010. The investigations were based on phytosociological relevés made by the Braun-Blanquet method.

The greatest numbers of localities of the analyzed association were found in the mesoregions located in the south-western part of the Południowopolska Lowland, i.e. the Kałuszyn Upland, Węgrów Lowering, Żelechów Upland, the south-western part of the Łuków Plain, and the southern part of the Siedlce Upland. Fewer patches of this association were reported from the eastern and north-eastern part of the Południowopolska Lowland, in particular from the Podlasie Gorge of Bug. With the exception of the latter one, in all the mesoregions the patches of the analyzed association exhibited internal variability reflecting the diversity of habitat moisture conditions, which was manifested by the occurrence of hygrophilous species in the analyzed phytocoenoses. They comprised patches of Arnoserido-Scleranthetum with Illecebrum verticillatum, which are regarded as threatened with extinction in Poland and Europe. The phytocoenoses of Arnoserido-Scleranthetum with the dominance of Anthoxanthum aristatum are particularly noteworthy as a reflection of degenerative changes caused by the mass occurrence of this expansive species.
Recorregut de recerca geològica i mineralògica per les comarques de Gúdar – Javalambre i de l´Alcalatén: des de Mosqueruela a Puertomingalvo, Sant Joan de Penyagolososa i a Vistabella del Maestrat
Authors: Mata Perelló Josep Maria , Sanz Balagué Joaquim
Published: July 2015

Itinerari realitzat el dia 6 de desembre del 2014. Aquest itinerari es desenvoluparà íntegrament per una de les unitats geològiques que constitueixen el País Valencià: concretament per la que ocupa la major part de la seva superfície, per la Serralada Ibèrica (i dintre d´aquesta pels sectors denominats Muntanyam de Castelló. També, es podria incloure bona part del recorregut, dintre de la denominada Conca del Maestrat. Així, l´itinerari discorrerà íntegrament per la zona també denominada del Maestrat, pels seus sectors corresponents a la Zona d´Enllaç entre les dues serralades anteriorment esmentades, de direccions: NE-SW (o NNE-SSW) i WNW-ESE (de vegades NW-SE), corresponents a les alineacions catalana i ibèrica, respectivament. En funció d´aquestes circumstàncies ens trobarem molts indrets amb clares interferències entre les dues direccions acabades d´esmentar; tot i que en aquestes interferències predominarà quasi sempre en aquesta zona, la direcció ibèrica. Aquest conjunt, es troba constituït majoritàriament per relleus mesozoics (fonamentalment pertanyents al Cretàcic i al Juràssic), de naturalesa calcària, com succeeix al propi cim del Penyagolosa l´indret considerat com al més alt del País Valencià. El recorregut de l´itinerari passarà per dues comarques: la del Gúdar – Javalambre (Teruel) i la de l´Alcalatén (Castelló). Així, el recorregut començarà a la primera comarca, prop de la població de Mosqueruela, per tal d´anar per la comarca fins arribar prop de la Puertomingalvo. Després es penetrarà a la segona comarca, per la qual es circularà fins a Vistabella del Maestrat, per on finalitzarà el recorregut, després d´haver-nos apropat al Penyagolosa.
Édition et répertoire national au Québec
Authors: Robert Lucie
Published: July 2015

L’édition théâtrale ne conserve à la mémoire qu’une partie de la représentation. Elle suppose un travail d’écriture, c’est-à-dire de mise en forme de la parole, et elle engage l’auteur dramatique à se concevoir comme un écrivain. Enfin, elle fixe le texte de manière à peu près définitive. Quels seraient les principes qui, au Québec, ont engagé l’édition de certains textes dramatiques et pas des autres? L’édition est-elle parvenue à constituer un véritable répertoire dramatique à la disposition des troupes, ou répond-elle d’abord à d’autres impératifs (littéraires, politiques ou pédagogiques)? A-t-elle contribué à la consécration de l’auteur dramatique comme écrivain et à la formation d’un «  Parnasse des auteurs dramatiques  » (Bourqui, Caldicott et Forestier,Le Parnasse du théâtre, 2007)? Enfin, y a-t-il vraiment au Québec un répertoire national? Telles sont les questions qui seront ici soulevées.
De la place des spectateurs dans les mouvements de répertoire
Authors: Mervant-Roux Marie-Madeleine
Published: July 2015

L’étude du répertoire privilégié par les théâtres d’amateurs et des processus selon lesquels celui-ci se constitue conduit à dissocier d’une façon générale la pratique du repertorium (de la liste), dont la fonction est d’abord la structuration du temps collectif sur des critères partagés, et celle de la sélection esthétique, censée déterminer l’inventaire des grandes oeuvres. Elle invite à examiner le rôle des spectateurs ordinaires dans la définition des choix officiellement effectués par les spécialistes de l’art théâtral.
Le(s) répertoire(s) du théâtre populaire : des rapports protéiformes à l’idée de nation
Authors: Denizot Marion
Published: July 2015

Le mouvement du théâtre populaire naît, en France, au tournant des XIXeet XXesiècles, en réaction à un état du théâtre jugé décadent car soumis aux contraintes mercantiles et destiné en priorité au divertissement de la bourgeoisie. Après la période des « pionniers », marquée par les figures de Romain Rolland, Maurice Pottecher, Jacques Copeau ou Firmin Gémier, s’épanouit après la Seconde Guerre mondiale une seconde génération, représentée par Jean Vilar et les hommes de la décentralisation (Jean Dasté, André Clavé, Guy Parigot, Hubert Gignoux, Maurice Sarrazin…). Si ces artistes partagent une conception du peuple sensiblement similaire (le peuple entendu dans le sens depopulus, et non commeplebs), leur rapport au répertoire diffère, entre la volonté des pionniers de fonder un nouveau répertoire et celle des héritiers de promouvoir la diffusion des chefs-d’oeuvre de l’humanité, c’est-à-dire d’un répertoire que l’on a pu qualifier de « classique », qu’il soit français ou étranger. Pourtant, au-delà de ces différences, l’article se propose de montrer comment le répertoire du théâtre populaire engage deux fonctions de la culture : une fonction intégratrice au sein d’une nation constituée par une langue commune et une fonction éducatrice au sein d’une société industrielle.
Les Belles-Soeurs au présent : prolégomènes à l’étude d’un lieu de mémoire
québécois
Authors: Jubinville Yves
Published: July 2015

Texte du répertoire, oeuvre classique, chef-d’oeuvre ou repère culturel. La
terminologie utilisée pour parler de l’oeuvre-phare de Michel Tremblay, Les
Belles-Soeurs, n’a cessé de s’élargir. Elle témoignerait de la pluralité de ses
significations et des usages multiples dont l’oeuvre a été l’objet dans les champs
esthétique (théâtral), social et culturel. Cette réalité plaide en faveur d’un modèle
d’interprétation qui ne soit pas limité à celui que pratique habituellement l’historien du
théâtre. Car au-delà de l’oeuvre littéraire et dramatique, Les Belles-Soeurs
représente un objet dense et complexe qui commande en effet une enquête capable de prendre
en compte le phénomène dans sa globalité. À la fois texte de théâtre, événement scénique,
culturel et politique, fait social et fait de langage, la pièce de Tremblay, considérée sous
l’angle des échos qu’elle produit dans la trame des événements et des discours qui façonnent
la société québécoise, correspond parfaitement à la définition du « lieu de mémoire »
développée par Pierre Nora. Cet article jette les bases d’une enquête envisagée dans la
suite des travaux devant conduire à une édition critique des Belles-Soeurs. La
théorie des « lieux de mémoire » y est discutée à la lumière des enjeux spécifiques au
contexte québécois dans le but de saisir la pièce de Tremblay au croisement de plusieurs
domaines discursifs et de régimes de temporalité.
Le naturalisme détourné : le Wooster Group face au répertoire classique
Authors: Arfara Katia
Published: July 2015

Cet article est focalisé sur deux performances devenues emblématiques du travail du Wooster Group sur le répertoire, Brace up! (1991), d’après Les trois soeurs d’Anton Tchekhov, et Hamlet (2006). Il examine plus particulièrement la déstructuration de la tradition naturaliste qui a dominé la longue histoire scénique de ces « classiques » par une approche intermédiale du répertoire qui restaure un regard critique sur les esthétiques dominantes tout en maintenant la composition scénique ouverte à d’innombrables possibilités.
Faut-il oublier la création pour accéder au répertoire?
Authors: Beauchamp Hélène
Published: July 2015

L’idée d’un répertoire théâtral au Québec est intimement liée à l’existence d’une dramaturgie nationale réclamée par l’auteur et metteur en scène Gratien Gélinas dès 1940. Il ouvre son théâtre de la Comédie canadienne en 1958 avec Un simple soldat de Marcel Dubé, autre auteur fondateur. À compter des années 1960, leurs pièces sont reprises et qualifiées désormais de « classiques ». Ma proposition est à l’effet qu’un répertoire est institué quand les pièces, ayant été reprises, quittent leurs premiers interprètes et gagnent en autonomie grâce à l’irrévérence et à la résistance de nouveaux metteurs en scène. Ces « classiques » sont alors traversés par d’autres imaginaires et produits selon des modes différents.
Ekphrasis
Authors: Nancy Jean-Luc
Published: July 2015

Cette suite de fragments constitue autant d’approches de l’image (tableau, dessin, photographie) et du rapport entre voir et dire qu’elle suscite. Tout en proposant une définition précise de l’ekphrasis qui ne se réduit ni au commentaire, ni à l’analyse, ni à l’évaluation, mais se présente comme « parole issue de l’oeuvre », l’auteur la met ici à l’oeuvre en se tenant au plus près de chaque image et tente de « répondre » à ce qui se donne à voir au premier regard dans l’image, chaque fois de facture et de teneur diverses. Dans la coda, la notion d’exphansis est mise en regard de celle d’ekphrasis, retournant ainsi encore le rapport du texte et de l’image en opérant le passage de l’écriture de l’image à l’image de la pensée.
Lettre à Adel Abdessemed
Authors: Cixous Hélène
Published: July 2015

Dans cette lettre adressée à l’artiste Adel Abdessemed qui accompagne une suite de dessins à la pierre noire intitulée Mon Enfant et une sculpture (« Untiltled ») offrant une version saisissante du motif du double sacrifice d’Abraham/Isaac, Hélène Cixous médite sur la puissance de l’art et de l’écriture, saluant en eux ce qui coupe le souffle quand ils captent dans l’acte, dans « l’instant arrêté », « le Sans Parole », le « Moment incompréhensible » qu’aucune phrase, aucun discours, ne peuvent « commenter, expliquer, affirmer ».
Aperçues (fragments d’un journal)1
Authors: Didi-Huberman Georges
Published: July 2015

Dans ces notes prélevées de ses carnets qui s’échelonnent sur dix ans, Georges Didi-Huberman interroge la fragilité et la résistance entêtante de l’image, ce qui s’ouvre en elle et appelle le regard, à la limite de la perception et du sensible : détails insolites, approches et distances équivoques, signes continus et discontinus, déposition à l’oeuvre dans la composition même, cadrage et regard tranché, carnation et couleurs qui sont le réel sujet du tableau, chien rejeté dans l’ombre, juste devant nous, et que personne ne voit, ou encore ce fil rouge que, grâce à Vermeer, nous n’oublierons jamais. L’ekphrasis répond alors à ces choses aperçues, à peine visibles ou au contraire rendues visibles par l’image, juste « assez étranges pour êtres vues et interrogées ». Le langage qui entre en résonance avec elles n’est plus discours ni expression, mais « sortie du discours hors de lui-même en vue de décrire quelque chose qui semblait d’abord impossible à exprimer » – extases de phrases.
Riopelle, l’ekphrasis et l’invisibilité
Authors: Gagnon François-Marc
Published: July 2015

Cet article interroge ce qu’il advient de l’ekphrasis quand les peintres, comme c’est le cas de ceux qui furent influencés par l’automatisme, nient toute intention au départ de l’oeuvre, laquelle se trouve ainsi non préconçue. En introduisant le hasard et un facteur d’invisibilité (grâce à l’usage exclusif de la spatule pour peindre), Riopelle met pour ainsi dire l’ekphrasis en échec. N’obéissant à aucun programme iconographique préalable, l’oeuvre s’affirme par ses seules qualités plastiques.
« Images pour que notre main s’émeuve »
Authors: Décarie Isabelle
Published: July 2015

Depuis plus de trente ans, l’historien de l’art et philosophe Georges Didi-Huberman s’attache à exposer les conditions d’apparition de l’image et son rapport de plus en plus problématique, « en crise », dirait-il, à la représentation classique. Il s’agit dans cet article d’analyser la façon originale avec laquelle Didi-Huberman regarde une oeuvre d’art, depuis un angle toujours décalé qu’il emprunte à la psychanalyse et tout particulièrement à l’interprétation des rêves. Entre association d’idées et vision « voyante », concentration et attention flottante, l’approche de Didi-Huberman saisit au vol (comme la phalène auquel il fait souvent référence) ce que les historiens positivistes de l’art n’aperçoivent pas toujours dans une oeuvre. Se rapprochant en ce sens de Jacques Derrida qui, se tenant toujours aux abords de l’art, fait voir tout autre chose dans les « dessous » des oeuvres, Didi-Huberman convertit dès lors, par une attention sensible portée à l’écriture, le trouble qui lui vient quand il regarde par exemple un pan de matière brute de peinture dans une toile de Vermeer ou une souche carbonisée. En empruntant la langue des poètes, il cisèle son écriture d’allitérations, donnant ainsi une cadence sonore à son style qui se démarque de celui sans « papillonnage » de ses contemporains. Entre écriture et histoire, poésie et discours, les essais toujours inventifs de Didi-Huberman possèdent une qualité singulière où certaines questions entourant l’enfance, comme dans plusieurs textes de Derrida, semblent insister pour émouvoir le regard et l’écriture.
Passages d’innocence : la différence photographique dans l’oeuvre de Jacques Derrida
Authors: Carotenuto Silvana , Rodriguez Tristan
Published: July 2015

Cet article présente une lecture d’ensemble des différents textes que le philosophe a consacrés à l’art et à la technique de la photographie, de l’oraison funèbre dédiée à Roland Barthes (1981) à ses derniers textes brefs accompagnant Diaspora. Terres natales de l’exil de Frédéric Brenner (2003). Le texte aborde quelques-uns des motifs liés aux questions de la métonymie, du dé/montage comme dé/limitation de la représentation, de la vérité, des temporalités et espaces du développement, de la célébration et du rituel de l’art photographique. Derrida fait rarement usage de l’ekphrasis aux dépens des photographies qu’il lit ; il écrit plutôt la « graphie de la lumière », avec sa référentialité complexe, ses retours spectraux, à travers des effets et des affects déconstruits, à l’intérieur des demeures fragiles et vulnérables qu’elle illumine : telle est la différence de l’interprétation derridienne des images et de la vision.
De l’iconographie : Jean-Luc Nancy et la question de l’image
Authors: Ferrari Federico , Rodriguez Tristan
Published: July 2015

Cet article s’intéresse au rapport entre l’écriture et l’image, mieux : à la possibilité même d’une iconographie. Jean-Luc Nancy a, à notre époque, montré cette possibilité à l’oeuvre. C’est donc à sa pensée sur l’image qu’est consacré ce texte. Chaque penseur est une occasion de penser : il n’y a rien à « reconstruire », aucune théorie à clarifier, à expliquer ou à illustrer, mais plutôt la nécessité de réactiver une pensée, de lui rendre toutes ses potentialités inexprimées, ou seulement exprimées selon une tonalité déterminée, selon les cordes d’une voix particulière. L’oeuvre de Jean-Luc Nancy, et encore davantage la partie de son corpus dédiée à l’image, n’échappe pas à cette règle. On relira donc ses oeuvres consacrées à l’image à la lumière de la pensée iconologique de Panofsky et de l’histoire de l’art afin d’esquisser la possibilité d’une iconographie considérée comme pensée figurative et ontologie de l’image : une pratique iconographique capable de s’exposer à la question même de la pensée, de demander compte de ce que signifie penser, penser par images et à travers les images.
« Par-dessus le marché » : Derrida et la performativité de l’ekphrasis
Authors: Rabaté Jean-Michel
Published: July 2015

Partant de l’expression « par-dessus le marché », telle que Derrida l’utilise dans une conversation avec l’artiste coréenne Soun-Gui Kim au sujet des apories et paradoxes créés par notre marché mondial de l’art, j’examine la logique de cette expression idiomatique qui fonctionne comme un performatif ekphrastique, posant à la fois l’excès et son excès. Ceci se relie au silence qui accompagne le dévoilement de la vérité dans et par l’art. Soun-Gui Kim interprète ce silence en termes bouddhistes proches de son travail avec John Cage. J’évoque alors la dialectique du silence et de la musique chez Cage avant de rouvrir le débat entre Derrida et Paul de Man au sujet de la musique et de la voix chez Jean-Jacques Rousseau.
L’ekphrasis à contretemps
Authors: Michaud Ginette , Rodriguez Tristan
Published: July 2015

À travers l’ekphrasis d’un tableau de Rembrandt, Autoportrait en Zeuxis, une rencontre énigmatique a lieu, à contretemps, ou à retardement, entre ce tableau et une photographie de Jacques Derrida prise par Raymond Depardon en juin 2004. La ressemblance troublante levée par l’autoportrait de Rembrandt, particulièrement dans la version révélée par les rayons X, interroge autant la portée du regard de Derrida (aura-t-il « survu » cette image au moment de la prise photographique ?) que l’effet de la survie inscrite dans le sourire indécidable dont le philosophe aura fait ses « derniers mots ». Énigme du palimpseste qui se joue ici entre le peintre et le philosophe, sans négliger l’intercession d’un tiers, passeur déterminant dans cette scène, Jean Genet.
Chromerid genomes reveal the evolutionary path from photosynthetic algae to obligate intracellular parasites
Authors: Woo Yong H , Ansari Hifzur , Otto Thomas D , Klinger Christen M , Kolisko Martin , Michálek Jan , Saxena Alka , Shanmugam Dhanasekaran , Tayyrov Annageldi , Veluchamy Alaguraj , Ali Shahjahan , Bernal Axel , del Campo Javier , Cihlář Jaromír , Flegontov Pavel , Gornik Sebastian G , Hajdušková Eva , Horák Aleš , Janouškovec Jan , Katris Nicholas J , Mast Fred D , Miranda-Saavedra Diego , Mourier Tobias , Naeem Raeece , Nair Mridul , Panigrahi Aswini K , Rawlings Neil D , Padron-Regalado Eriko , Ramaprasad Abhinay , Samad Nadira , Tomčala Aleš , Wilkes Jon , Neafsey Daniel E , Doerig Christian , Bowler Chris , Keeling Patrick J , Roos David S , Dacks Joel B , Templeton Thomas J , Waller Ross F , Lukeš Julius , Oborník Miroslav , Pain Arnab
Published: July 2015

The eukaryotic phylum Apicomplexa encompasses thousands of obligate intracellular parasites of humans and animals with immense socio-economic and health impacts. We sequenced nuclear genomes of Chromera velia and Vitrella brassicaformis, free-living non-parasitic photosynthetic algae closely related to apicomplexans. Proteins from key metabolic pathways and from the endomembrane trafficking systems associated with a free-living lifestyle have been progressively and non-randomly lost during adaptation to parasitism. The free-living ancestor contained a broad repertoire of genes many of which were repurposed for parasitic processes, such as extracellular proteins, components of a motility apparatus, and DNA- and RNA-binding protein families. Based on transcriptome analyses across 36 environmental conditions, Chromera orthologs of apicomplexan invasion-related motility genes were co-regulated with genes encoding the flagellar apparatus, supporting the functional contribution of flagella to the evolution of invasion machinery. This study provides insights into how obligate parasites with diverse life strategies arose from a once free-living phototrophic marine alga.
Phytotoxin production in Aspergillus terreus is regulated by independent environmental signals
Authors: Gressler Markus , Meyer Florian , Heine Daniel , Hortschansky Peter , Hertweck Christian , Brock Matthias
Published: July 2015

Secondary metabolites have a great potential as pharmaceuticals, but there are only a few examples where regulation of gene cluster expression has been correlated with ecological and physiological relevance for the producer. Here, signals, mediators, and biological effects of terrein production were studied in the fungus Aspergillus terreus to elucidate the contribution of terrein to ecological competition. Terrein causes fruit surface lesions and inhibits plant seed germination. Additionally, terrein is moderately antifungal and reduces ferric iron, thereby supporting growth of A. terreus under iron starvation. In accordance, the lack of nitrogen or iron or elevated methionine levels induced terrein production and was dependent on either the nitrogen response regulators AreA and AtfA or the iron response regulator HapX. Independent signal transduction allows complex sensing of the environment and, combined with its broad spectrum of biological activities, terrein provides a prominent example of adapted secondary metabolite production in response to environmental competition.
Deconvoluting heme biosynthesis to target blood-stage malaria parasites
Authors: Sigala Paul A , Crowley Jan R , Henderson Jeffrey P , Goldberg Daniel E
Published: July 2015

Heme metabolism is central to blood-stage infection by the malaria parasite Plasmodium falciparum. Parasites retain a heme biosynthesis pathway but do not require its activity during infection of heme-rich erythrocytes, where they can scavenge host heme to meet metabolic needs. Nevertheless, heme biosynthesis in parasite-infected erythrocytes can be potently stimulated by exogenous 5-aminolevulinic acid (ALA), resulting in accumulation of the phototoxic intermediate protoporphyrin IX (PPIX). Here we use photodynamic imaging, mass spectrometry, parasite gene disruption, and chemical probes to reveal that vestigial host enzymes in the cytoplasm of Plasmodium-infected erythrocytes contribute to ALA-stimulated heme biosynthesis and that ALA uptake depends on parasite-established permeability pathways. We show that PPIX accumulation in infected erythrocytes can be harnessed for antimalarial chemotherapy using luminol-based chemiluminescence and combinatorial stimulation by low-dose artemisinin to photoactivate PPIX to produce cytotoxic reactive oxygen. This photodynamic strategy has the advantage of exploiting host enzymes refractory to resistance-conferring mutations.
The Impact of a Cooperative Learning Program on the Academ-ic Achievement in Mathematics and Language in Fourth Grade Students and its Relation to Cognitive Style
Authors: Vega Mery Luz , Hederich Christian M.
Published: July 2015

This study is expected to determine the impact of a program based on the cooperative learning methodology. This, in comparison to a traditional learning situation in both mathematics and language achievement. The study was carried out on a group of fourth grade students of primary school. In addition, it tried to find the differential impact according to the cognitive style in the field dependence-independence dimension. This work was carried out with 76 students of the Colegio José Martí I.E.D. (Bogotá-Colombia) ranging from 8–12 years of age. The control group received a traditional teaching methodology and the experimental group received the cooperative learning program, composed of 35 sessions (from July to November 2009). All the participants were tested in mathematics and language performance, before and after the intervention. All of them were tested in cognitive style as well. The results suggested that the cooperative learning methodology benefited importantly the academic achievement of the students in mathematics in contrast to the competitive and individualist situations. The results also suggested that the three cognitive style groups were positively affected from the cooperative learning situation. These results were not found in the language area.
Deep structure of the Santos Basin‐São Paulo Plateau System, SE Brazil
Authors: Evain M. , Afilhado A. , Rigoti C. , Loureiro A. , Alves D. , Klingelhoefer F. , Schnurle P. , Feld A. , Fuck R. , Soares J. , de Lima M. Vinicius , Corela C. , Matias L. , Benabdellouahed M. , Baltzer A. , Rabineau M. , Viana A. , Moulin M. , Aslanian D.
Published: July 2015

The structure and nature of the crust underlying the Santos Basin‐São Paulo Plateau System (SSPS), in the SE Brazilian margin, are discussed based on five wide‐angle seismic profiles acquired during the Santos Basin (SanBa) experiment in 2011. Velocity models allow us to precisely divide the SSPS in six domains from unthinned continental crust (Domain CC) to normal oceanic crust (Domain OC). A seventh domain (Domain D), a triangular shape region in the SE of the SSPS, is discussed by Klingelhoefer et al. (2014). Beneath the continental shelf, a ~100 km wide necking zone (Domain N) is imaged where the continental crust thins abruptly from ~40 km to less than 15 km. Toward the ocean, most of the SSPS (Domains A and C) shows velocity ranges, velocity gradients, and a Moho interface characteristic of the thinned continental crust. The central domain (Domain B) has, however, a very heterogeneous structure. While its southwestern part still exhibits extremely thinned (7 km) continental crust, its northeastern part depicts a 2–4 km thick upper layer (6.0–6.5 km/s) overlying an anomalous velocity layer (7.0–7.8 km/s) and no evidence of a Moho interface. This structure is interpreted as atypical oceanic crust, exhumed lower crust, or upper continental crust intruded by mafic material, overlying either altered mantle in the first two cases or intruded lower continental crust in the last case. The deep structure and v‐shaped segmentation of the SSPS confirm that an initial episode of rifting occurred there obliquely to the general opening direction of the South Atlantic Central Segment.
Nucleation process of an M2 earthquake in a deep gold mine in South Africa inferred from on‐fault foreshock activity
Authors: Yabe Yasuo , Nakatani Masao , Naoi Makoto , Philipp Joachim , Janssen Christoph , Watanabe Takayoshi , Katsura Taishi , Kawakata Hironori , Georg Dresen , Ogasawara Hiroshi
Published: July 2015

Using a network of sensitive high‐frequency acoustic emission sensors, we observed foreshock activity of an Mw 2.2 earthquake (main shock) in a deep gold mine in South Africa. Foreshock activity, which selectively occurred on a part of the rupture plane of the forthcoming main shock, lasted for at least 6 months until the main shock. Rock samples recovered from the main shock source region showed evidence of ancient hydrothermal alteration on the main shock rupture plane, suggesting that the foreshock activity occurred on a preexisting weakness. The foreshocks during 3 months before the main shock were concentrated in three clusters (F1–F3), which we interpret as representing localized preslip at multiple sites. While the location of mining area, the source of stress perturbations, changed with time, the locations of foreshock clusters did not change, suggesting that the preslip patches were controlled by strength heterogeneity rather than stress distribution. Activity over the entire foreshock area was generally constant, but the largest cluster (F2) showed accelerated activity starting at least 7 days before the main shock, while mining stress did not increase in this period. The main shock initiated at a point close to F1, away from F2. All the six foreshocks during the final 41 h occurred in F1 and F2 and in‐between. These suggest that in the last stage of the preparation process of the main shock, preslip patches interacted with each other through the stress concentration ahead of the expanding preslip patch (F2), which should be the only driving force of the preparation process under the constant external load.
A new seismically constrained subduction interface model for Central America
Authors: Kyriakopoulos C. , Newman A.V. , Thomas A. M. , Moore‐Driskell M. , Farmer G. T.
Published: July 2015

We provide a detailed, seismically defined three‐dimensional model for the subducting plate interface along the Middle America Trench between northern Nicaragua and southern Costa Rica. The model uses data from a weighted catalog of about 30,000 earthquake hypocenters compiled from nine catalogs to constrain the interface through a process we term the “maximum seismicity method.” The method determines the average position of the largest cluster of microseismicity beneath an a priori functional surface above the interface. This technique is applied to all seismicity above 40 km depth, the approximate intersection of the hanging wall Mohorovičić discontinuity, where seismicity likely lies along the plate interface. Below this depth, an envelope above 90% of seismicity approximates the slab surface. Because of station proximity to the interface, this model provides highest precision along the interface beneath the Nicoya Peninsula of Costa Rica, an area where marked geometric changes coincide with crustal transitions and topography observed seaward of the trench. The new interface is useful for a number of geophysical studies that aim to understand subduction zone earthquake behavior and geodynamic and tectonic development of convergent plate boundaries.
Impact of mesoscale meteorological processes on anomalous radar propagation conditions over the northern Adriatic area
Authors: Telišman Prtenjak Maja , Horvat Igor , Tomažić Igor , Kvakić Marko , Viher Mladen , Grisogono Branko
Published: July 2015

The impact of mesoscale structures on the occurrence of anomalous propagation (AP) conditions for radio waves, including ducts, superrefractive, and subrefractive conditions, was studied. The chosen meteorological situations are the bora wind and the sporadic sea/land breeze (SB/LB) during three selected cases over a large portion of the northern Adriatic. For this purpose, we used available radio soundings and numerical mesoscale model simulations (of real cases and their sensitivity tests) at a horizontal resolution of 1.5 km and 81 vertical levels. The model simulated the occurrences of AP conditions satisfactorily, although their intensities and frequency were underestimated at times. Certain difficulties appeared in reproducing the vertical profile of the modified refractive index, which is mainly dependent on the accuracy of the modeled humidity. The spatial distributions of summer AP conditions reveal that the surface layer above the sea (roughly between 30 and 100 m asl) is often covered by superrefractive conditions and ducts. The SB is highly associated with the formations of AP conditions: (i) in the first 100 m asl, where trapping and superrefractive conditions form because of the advection of cold and moist air, and (ii) inside the transition layer between the SB body and the elevated return flow in the form of subrefractive conditions. When deep convection occurs, all three types of AP conditions are caused by the downdraft beneath the cumulonimbus cloud base in its mature phase that creates smaller but marked pools of cold and dry air. The bora wind usually creates a pattern of AP conditions associated with the hydraulic jump and influences distribution of AP conditions over the sea surface.
Trends in the local Hadley and local Walker circulations
Authors: Schwendike Juliane , Berry Gareth J. , Reeder Michael J. , Jakob Christian , Govekar Pallavi , Wardle Richard
Published: July 2015

The linear trend in the local Hadley and Walker circulations from 1979 to 2009 is calculated. These local circulations are defined through a decomposition of the vertical mass flux into its zonal and meridional components. Defining the local circulation this way ensures that the two orthogonal circulations (the local Hadley and Walker circulations) sum to the original circulation even after averaging the circulations regionally. Large regional differences in changes in the local Hadley and Walker circulations over a 31 year period are found. For example, the local Hadley circulation has shifted southward over Africa, the Maritime Continent, and the western and central Pacific by about 1°. Over the Americas and the Atlantic the local Hadley circulation has strengthened by about 1–5%. The zonal component of the vertical mass flux has increased by about 10–20% in the tropics over all continents and decreased over the adjacent oceans by about 10–20%. Although the local Walker circulations in the Indian Ocean and the Atlantic have weakened, the circulation in the Pacific has changed little (about 1–2%). The local Walker circulations in all ocean basins have shifted westward by about 1–2°on average.
A novel equation for determining the suction stress of unsaturated soils from the water retention curve based on wetted surface area in pores
Authors: Greco Roberto , Gargano Rudy
Published: July 2015

A novel equation is proposed for the evaluation of the suction stress of an unsaturated soil. The equation, based on the assumption that suction is transmitted to soil solid particles only through their wet external surface, allows to easily derive the soil suction characteristic curve from the water retention curve. The proposed equation has been verified against published experimental data of suction stress smaller than 1 MPa for soils of various characteristics. In all cases, an excellent agreement between predicted and observed values of suction stress is achieved, showing that the proposed equation performs better than other currently adopted expressions for the evaluation of soil suction stress.
Surface water types and sediment distribution patterns at the confluence of mega rivers: The Solimões‐Amazon and Negro Rivers junction
Authors: Park Edward , Latrubesse Edgardo M.
Published: July 2015

Large river channel confluences are recognized as critical fluvial features because both intensive and extensive hydrophysical and geoecological processes take place at this interface. However, identifications of suspended sediment routing patterns through channel junctions and the roles of tributaries on downstream sediment transport in large rivers are still poorly explored. In this paper, we propose a remote sensing‐based approach to characterize the spatiotemporal patterns of the postconfluence suspended sediment transport by mapping the surface water distribution in the ultimate example of large river confluence on Earth where distinct water types meet: The Solimões‐Amazon (white water) and Negro (black water) rivers. The surface water types distribution was modeled for three different years: average hydrological condition (2007) and 2 years when extreme events occurred (drought‐2005 and flood‐2009). Amazonian surface water domination along the main channel is highest during the water discharge rising season. Surface water mixing along the main channel depends on the hydrological seasons with the highest mixed‐homogenized area observed during water discharge peak season and the lowest during discharge rising season. Water mixture also depends on the yearly hydrological regime with the highest rates of water mixing in 2009, followed by 2005 and 2007. We conclude that the dominant mixing patterns observed in this study have been persistent over a decadal scale and the anabranching patterns contribute to avoid a faster mixing in a shorter distance. Our proposed approach can be applied to a variety of morphodynamic and environmental analyses in confluences of large rivers around the world.
Short‐term variability in euphotic zone biogeochemistry and primary productivity at Station ALOHA: A case study of summer 2012
Authors: Wilson Samuel T. , Barone Benedetto , Ascani Francois , Bidigare Robert R. , Church Matthew J. , del Valle Daniela A. , Dyhrman Sonya T. , Ferrón Sara , Fitzsimmons Jessica N. , Juranek Laurie W. , Kolber Zbigniew S. , Letelier Ricardo M. , Martínez‐García Sandra , Nicholson David P. , Richards Kelvin J. , Rii Yoshimi M. , Rouco Mónica , Viviani Donn A. , White Angelicque E. , Zehr Jonathan P. , Karl David M.
Published: July 2015

Time‐series observations are critical to understand the structure, function, and dynamics of marine ecosystems. The Hawaii Ocean Time‐series program has maintained near‐monthly sampling at Station ALOHA (22°45′N, 158°00′W) in the oligotrophic North Pacific Subtropical Gyre (NPSG) since 1988 and has identified ecosystem variability over seasonal to interannual timescales. To further extend the temporal resolution of these near‐monthly time‐series observations, an extensive field campaign was conducted during July–September 2012 at Station ALOHA with near‐daily sampling of upper water‐column biogeochemistry, phytoplankton abundance, and activity. The resulting data set provided biogeochemical measurements at high temporal resolution and documents two important events at Station ALOHA: (1) a prolonged period of low productivity when net community production in the mixed layer shifted to a net heterotrophic state and (2) detection of a distinct sea‐surface salinity minimum feature which was prominent in the upper water column (0–50 m) for a period of approximately 30 days. The shipboard observations during July–September 2012 were supplemented with in situ measurements provided by Seagliders, profiling floats, and remote satellite observations that together revealed the extent of the low productivity and the sea‐surface salinity minimum feature in the NPSG.
Crystallographic preferred orientations may develop in nanocrystalline materials on fault planes due to surface energy interactions
Authors: Toy Virginia G. , Mitchell Thomas M. , Druiventak Anthony , Wirth Richard
Published: July 2015

A layer of substantially noncrystalline material, composed of partially annealed nanopowder with local melt, was experimentally generated by comminution during ∼1.5 mm total slip at ∼2.5 × 10−6 m s−1, Pconf ∼ 0.5 GPa, and 450°C or 600°C, on saw cut surfaces in novaculite. The partially annealed nanopowder comprises angular grains mostly 5–200 nm diameter in a variably dense packing arrangement. A sharp transition from wall rock to partially annealed nanopowder illustrates that the nanopowder effectively localizes shear, consistent with generation of nanoparticles during initial fragmentation, not by progressive grain size reduction. Dislocation densities in nanopowder grains or immediate wall rock are not significantly high, but there are planar plastic defects spaced at 5–200 nm parallel to the host quartz grain's basal plane. We propose these plastic defects developed into through‐going fractures to generate nanocrystals. The partially annealed nanopowder has a crystallographic preferred orientation (CPO) that we hypothesize developed due to surface energy interactions to maximize coincident site lattices (CSL) during annealing. This mechanism may also have generated CPOs recently described in micro/nanocrystalline calcite fault gouges.