bluuebunny/crossref_metadata_2025 huggingface dataset:
Land Cover Change in the Andes of Southern Ecuador—Patterns and Drivers
Authors: Curatola Fernández Giulia , Obermeier Wolfgang , Gerique Andrés , López Sandoval María , Lehnert Lukas , Thies Boris , Bendix Jörg
Published: March 2015

In the megadiverse tropical mountain forest in the Andes of southern Ecuador, a global biodiversity hotspot, the use of fire to clear land for cattle ranching is leading to the invasion of an aggressive weed, the bracken fern, which is threatening diversity and the provisioning of ecosystem services. To find sustainable land use options adapted to the local situation, a profound knowledge of the long-term spatiotemporal patterns of land cover change and its drivers is necessary, but hitherto lacking. The complex topography and the high cloud frequency make the use of remote sensing in this area a challenge. To deal with these conditions, we pursued specific pre-processing steps before classifying five Landsat scenes from 1975 to 2001. Then, we quantified land cover changes and habitat fragmentation, and we investigated landscape changes in relation to key spatial elements (altitude, slope, and distance from roads). Good classification results were obtained with overall accuracies ranging from 94.5% to 98.5% and Kappa statistics between 0.75 and 0.98. Forest was strongly fragmented due to the rapid expansion of the arable frontier and the even more rapid invasion by bracken. Unexpectedly, more bracken-infested areas were converted to pastures than vice versa, a practice that could alleviate pressure on forests if promoted. Road proximity was the most important spatial element determining forest loss, while for bracken the altitudinal range conditioned the degree of invasion in deforested areas. The annual deforestation rate changed notably between periods: ~1.5% from 1975 to 1987, ~0.8% from 1987 to 2000, and finally a very high rate of ~7.5% between 2000 and 2001. We explained these inconstant rates through some specific interrelated local and national political and socioeconomic drivers, namely land use policies, credit and tenure incentives, demography, and in particular, a severe national economic and bank crisis.
Un roman familial ré-écrit, ou Louis Aragon au Cambodge
Authors: Duterte Pierre
Published: March 2015

Le roman familial de Freud est certainement une protection mise en place par le système familial pour supporter une situation difficile ; il rend psychiquement acceptable ce qui serait, sans cette réécriture, insupportable. Cette ré-écriture de l’histoire ou de l’Histoire peut aussi très vite devenir un carcan, un piège, un obstacle à l’ouverture d’esprit et à la création. Pour le patient dont nous présentons le cas clinique, le roman et l’histoire familiale se mêlaient à l’Histoire avec un grand H.
Le rêve comme passerelle entre différents niveaux de fonctionnement au sein de la famille et du couple
Authors: Nicolò Anna Maria , Craba Ambra
Published: March 2015

Cet article réexamine quelques aspects de notre réflexion quant à l’apport, l’utilité et la spécificité des rêves en thérapie familiale d’orientation psychanalytique. Lorsqu’au cours d’un processus thérapeutique, un membre de la famille ou du couple raconte un rêve en séance, ce rêve représente selon nous un inducteur de changement dans la famille. D’une part, il peut être un point d’aboutissement dans l’élaboration de cet individu mais aussi du groupe familial et d’autre part, il stimule la poursuite du développement et du changement à un niveau intrapsychique et familial. Pour mieux comprendre cet aspect nous devons préciser l’utilisation du rêve par les membres du groupe familial ou du couple.
Histoire de famille et transgression des thérapeutes
Authors: Cassanas Jean , Girolet Marie-Hélène
Published: March 2015

Dans une séance en co-thérapie, l’un des deux thérapeutes propose de faire à la fin sa sculpture de la famille en y incluant l’autre thérapeute. Cette « transgression » s’avère être a posteriori un acte thérapeutique posant la question des relations complexes entre histoire de la famille, résonance et créativité.
L'obsession du local : une exception française ?
Authors: Giblin Béatrice
Published: March 2015

Tous les grands pays européens ont mis en place des réformes territoriales dans les quarante dernières années, réduisant drastiquement le nombre des communes. Quelles sont ces réformes ? Pourquoi la France rejoint-elle si tardivement le mouvement général ?
La Russie dans le cyberespace : représentations et enjeux
Authors: Limonier Kévin
Published: March 2015

Depuis une décennie, la Russie est devenue un acteur majeur du « cyberespace ». Disposant tout à la fois d’une économie numérique développée et d’une importante zone d’influence linguistique, la Fédération s’appuie sur cette nouvelle forme de puissance pour prolonger, sur les réseaux, les grandes postures géopolitiques qui caractérisent la Russie contemporaine. Cet article se propose donc d’étudier le segment russe du cyberespace sous l’angle des représentations territoriales et des rivalités de pouvoir qu’il suscite ou alimente. Il s’agira notamment de montrer qu’il constitue une importante « caisse de résonance » pour des problématiques qui concernent l’espace postsoviétique dans son ensemble.
La guerre des étoiles
Authors: Cardon Vincent
Published: March 2015

Cet article analyse des réactions de l’industrie hôtelière à l’introduction d’un site de commentaires en ligne. Qu’advient-il lorsque, sur un marché déjà très équipé, un nouvel acteur fait irruption dans la chaîne de définition de la qualité et de valorisation des produits ; qu’il propose au consommateur des principes d’évaluation se revendiquant comme neufs et une nouvelle économie informationnelle ? Comment réagissent les acteurs en présence ? Cohabitation pacifique ou, au contraire, lutte des principes de définition de la qualité et de l’information pertinente, autrement dit, « guerre des étoiles » ? La question revient à s’interroger sur la plasticité des régimes de coordination marchands lorsqu’ils sont confrontés à un choc exogène, en l’espèce, une innovation socio-technique autorisant de nouveaux modes de circulation de l’information et de cristallisation d’une connaissance sur le marché. Le cas de l’industrie du tourisme est propre à fournir quelques éléments d’élucidation des effets de l’introduction d’outils algorithmiques d’évaluation des biens sur la chaîne d’acteurs impliqués dans la coordination de l’offre et de la demande et dans la structuration du marché par la qualification des biens qui s’y échangent.
Quand une mode managériale s’institutionnalise
Authors: Pardi Tommaso
Published: March 2015

Dans cet article, nous analysons les conditions qui ont permis à une mode managériale, la lean production, de s’institutionnaliser. Par rapport au cycle de vie fréquent d’une mode managériale qui aboutit à son rejet, nous constatons que deux facteurs étaient absents : la réaction critique des travaux universitaires et la résistance collective des groupes d’acteurs négativement affectés par son introduction. Pour expliquer cette double anomalie, nous étudions les conditions d’élaboration et de réception de la thèse de la lean production sur la période qui précède et accompagne son institutionnalisation aux États-Unis. Cette analyse permet de mettre en exergue le rôle structurant joué par la privatisation et la marchandisation de la recherche universitaire américaine dans l’élaboration et la réception acritique de cette mode managériale.
Los conocimientos en el mercado
Authors: Le Velly Ronan , Goulet Frédéric , Mallard Alexandre
Published: March 2015

La sociología económica no ignora la cuestión del conocimiento al considerar la forma en que se han contemplado los motores de la acción económica. Así, varias publicaciones se refieren a una cuestión sociocognitiva fundamental: la interpretación de las situaciones y la anticipación de las consecuencias de las acciones. Las redes, la cultura, los dispositivos, las instituciones, los emprendedores, la competencia y la calidad pueden ser reexaminados en lo que respecta a las cuestiones de movilización de los conocimientos en la acción que les concierne. Aquí se examinan en profundidad tres temas: la incertidumbre, los problemas vinculados a la ausencia o inestabilidad del conocimiento en la definición de la calidad de los bienes; la heterogeneidad de los regímenes y tipos de conocimiento movilizados en la valoración de los bienes; la performatividad del conocimiento económico en el caso de la mercantilización de la producción de este conocimiento.
L'impact du micro-credit sur la croissance organique des tres petites entreprises camerounaises
Authors: Takoudjou Nimpa Alain , Djoutsa Wamba Léopold
Published: March 2015

Le présent travail est une contribution à la mesure de l’impact des micro-financements sur la croissance organique des TPE camerounaises. Dans ce cadre, il a été question non seulement de mobiliser un corpus théorique sur les facteurs explicatifs de la croissance des entreprises ; mais aussi d’identifier à travers une étude statistique, les facteurs qui s’apparentent à la réalité des TPE camerounaises. Sur le plan empirique, en mobilisant la méthode des groupes appariés, les tests d’association et de comparaison, sur un échantillon de 258 TPE camerounaises ; nous avons obtenus les résultats suivants : dans un premier temps on a pu établir, sur une période de douze mois, que l’impact du micro-crédit sur la croissance des TPE bénéficiaires est non significatif. Dans un second temps l’étude comparative montre qu’il existe une différence de niveau de croissance (chiffre d’affaires, marge bénéficiaire, niveau de production ou des achats, nombre d’actifs, nombre d’employés) entre les micro-entreprises bénéficiaires de crédit et les non bénéficiaires ; les bénéficiaires de crédit ayant une propension plus forte à la croissance que les non bénéficiaires. Toutefois, cette différence est non significative ; et par conséquent, ne pourrait s’expliquer par l’accès au crédit. Ces résultats nous permettent de constater que ce n’est pas nécessairement l’accès au crédit qui impulse la croissance de la TPE camerounaises. Ces résultats nous mettent également sur la piste des variables réelles (aptitudes managériales et entrepreneuriales du dirigeant, etc.) qui seraient des facteurs explicatifs de la croissance de cette catégorie d’entreprise.
Impact du changement de dirigeant sur la valeur des entreprises camerounaises : effet modérateur de la nature de départ et du contexte économique de l'entreprise
Authors: Djoutsa Wamba Léopold , Takoudjou Nimpa Alain , Wamba Henri
Published: March 2015

L’objectif de cet article est d’analyser l’effet modérateur du contexte économique de l’entreprise et de la nature de départ du dirigeant sur l’impact du changement d’un dirigeant sur la valeur de l’entreprise. A travers une méthodologie d’études d’événement, d’association et de comparaison sur un échantillon de 50 cas de changement de dirigeant sur la période 1990 à 2004 dans les sociétés anonymes au Cameroun, les résultats ont montré que l’impact du changement de dirigeant sur la valeur de l’entreprise est négatif et significatif. Toutefois, cet impact varie significativement avec la nature de départ du prédécesseur et le contexte économique de l’entreprise. En général, les résultats montrent que la nature de départ du prédécesseur et les variables liées au contexte économique de l’entreprise (performance de l’entreprise avant la succession, la taille de l’entreprise et l’environnement concurrentiel de l’entreprise) influencent à des degrés divers la relation entre le changement de dirigeant et la valeur de l’entreprise. Ces résultats suggèrent d’une part que l’impact négatif du changement de dirigeant est atténué si le départ du dirigeant est normal (retraite) ou forcé, si l’entreprise est de grande taille, ou si elle appartient à un environnement stable ou peu complexe. D’autre part, cet impact négatif est amplifié dans les entreprises de petite taille, dans les entreprises appartenant à un environnement très complexe ou très instable, ou encore si le départ du dirigeant est subi par le conseil d’administration.
Le financement du haut de bilan dans les PME camerounaises et tchadiennes
Authors: Ngongang Dagobert
Published: March 2015

Cette étude tente de mettre en évidence la relation qui pourrait exister, d’une part entre les caractéristiques des entreprises et les moyens et types de financement, et, d’autre part entre les types de financement et la performance des entreprises. L’étude empirique est faite sur un échantillon de 86 entreprises camerounaises et 85 entreprises tchadiennes. Les résultats montrent que les entreprises camerounaises et tchadiennes ont globalement le même comportement financier pour le financement du haut de bilan et que les points de divergences s’expliquent par le niveau de développement du système financier. Des nouveaux instruments financiers devraient être vulgarisés pour permettre aux PME de se développer.
Les dysfonctionnements révélateurs de coûts cachés dans les entreprises sénégalaises : quelles perspectives pour la maximisation de la valeur ?
Authors: Bampoky Boniface
Published: March 2015

L’Afrique de façon générale est un terrain encore peu exploré en termes de coûts-performances cachés. Une étude exploratoire qualitative suivie d’une phase statistique confirmatoire a permis de déceler les principaux dysfonctionnements porteurs de coûts cachés dans les entreprises sénégalaises. Les causes de ces dysfonctionnements dénotent les spécificités du contexte de la recherche (une économie en développement). Les voies d’implantation d’un modèle de contrôle de gestion socioéconomique sont proposées.
Pour une critique de l'économie de la croissance comme vecteur du développement
Authors: Clévenot Mickaël , Douyère David
Published: March 2015

L’économie de la connaissance est aujourd’hui envisagée comme voie de sortie du sous-développement pour les pays qui ne sont pas encore entrés dans un processus d’émergence. Il apparaît toutefois que de nombreuses conditions doivent être réunies pour atteindre cet objectif. Elles sont relatives notamment au degré de développement institutionnel, à la qualité de l’environnement technique et éducatif, alors même qu’elles dépendent largement du niveau de développement économique. Par conséquent, souhaiter voir émerger une économie fondée sur la connaissance dans les PVD revient à faire abstraction des conditions matérielles de la production de celle-ci. Le concept d’économie de la connaissance apparaît en effet très incertain qui semble procéder d’une réduction du travail et de la production à la seule dimension cognitive, oubliant, là encore, sa dimension matérielle. Apparue comme relais et prolongement de la notion de société de l’information, cette approche s’inscrit historiquement dans le souci d’un « dépassement » des idéologies marqué par l’extension du capitalisme des pays développés et se réduit à un déterminisme technologique oubliant l’importance de l’Histoire.
L'effet de la mise en place d'une stratégie de Responsabilité Sociale de l'entreprise sur la culture organisationnelle : Analyse, implications et enjeux pour le Sénégal
Authors: Simen Serge Francis , Ndao Assane
Published: March 2015

La responsabilité sociale des entreprises est au cœur des débats et des enjeux du développement durable et de l’avenir de notre monde. La prise en compte du risque environnemental impose un changement de mentalité au sein des entreprises. Pour ces dernières, il s’agit aujourd’hui d’identifier, d’évaluer et de maîtriser les risques pouvant survenir à n’importe quel moment. Cependant, ce changement de mentalité ne se fait pas toujours, ou se fait d’une mauvaise manière, omettant les aspects internes et/ou externes d’une organisation. Comment réussir alors à construire, au Sénégal, une politique de responsabilité sociale de manière intégrée s’il n’y a pas d’adaptation culturelle de l’organisation ? Car l’approche intégrée nous semble, pour nous-mêmes et pour beaucoup d’experts de ce domaine, la solution la plus durable. La résultante de cette première question est ensuite comment prévoir, organiser, effectuer ce processus de changement ou cette adaptation culturelle afin de développer au mieux une RSE  ? Quel(s) modèle(s) organisationnel(s) permettrai(en)t d’allier culture et structure pour la bonne marche d’une entreprise responsable et durable au Sénégal ? À partir d’une approche qualitative inductive basée sur l’étude de plusieurs cas d’entreprises, nous sommes convaincus que la RSE est plus un processus qu’un but en soi. Elle peut conduire l’entreprise à apporter des solutions à la fois globales et locales et être un agent transformateur de la société et de ses déséquilibres. De plus, la RSE a le potentiel de devenir un outil favorisant le développement durable et consolidant le rôle de l’entreprise par rapport à son environnement de manière plus harmonieuse. Toutefois, certaines conditions, dont dépend le futur de la RSE, sont à remplir. Il serait nécessaire de maintenir la pression publique, d’encourager l’innovation et la créativité, de promouvoir un rôle plus actif de la part des gouvernements et de réguler les activités des entreprises.
Swept-source Optical Coherence Tomography of Retinal Cavernous Hemangioma: A New Imaging Modality
Authors: Pastor-Idoate Salvador , Gil-Martinez Maria , Crim Nicolas , Quijano Claudia , Biswas Susmito , Charles Stephen , McLeod David , Stanga Paulo E.
Published: March 2015

The authors report a new, non-invasive diagnostic method in the diagnosis of retinal cavernous hemangioma (RCH). A 6-year-old girl was referred for a non-clearing retinal hemorrhage of 6 months’ duration. Fourier-domain optical coherence tomography (FD-OCT) showed an intraretinal lesion with cystic-like internal appearance. Optical shadowing was present, preventing establishment of any subretinal component to the lesion. Swept-source OCT (SS-OCT) showed an intraretinal lesion consisting of a group of clearly defined grape-like caverns with overlying preretinal tissue. Wide-field fundus fluorescein angiography (WF-FFA) confirmed the diagnosis of RCH. SS-OCT was superior to FD-OCT in showing the internal anatomy of the RCH and allowing for the measurement of its structures, confirming the intraretinal location of the lesion and the presence of an associated preretinal tissue. SS-OCT may assist in cases in which hemorrhage prevents an accurate diagnosis by ophthalmoscopy or angiography, thus becoming an alternative imaging method to confirm the diagnosis of RCH while avoiding the risks of fluorescein angiography in children.

[
J Pediatric Ophthalmol Strabismus
. 2015;52:e4–e7.]
Corneal Asymmetry Analysis by Pentacam Scheimpflug Tomography for Keratoconus Diagnosis
Authors: Galletti Jonatán D. , Ruiseñor Vázquez Pablo R. , Minguez Natalia , Delrivo Marianella , Bonthoux Fernando Fuentes , Pförtner Tomás , Galletti Jeremías G.
Published: March 2015

PURPOSE:

To evaluate intereye corneal asymmetry in Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany) indices as a diagnostic method between normal patients and patients with keratoconus.

METHODS:

A retrospective, observational case series of 177 healthy, 44 indeterminate, and 121 patients with keratoconus classified by Pentacam ectasia detection indices, randomized to analysis and validation datasets. Intereye asymmetry in 20 Scheimpflug tomography corneal descriptors was calculated and compared to develop diagnostic models.

RESULTS:

Intereye asymmetry was not correlated with anisometropia in healthy controls but was correlated with the ectasia grade of the worse eye in patients with keratoconus. Patients with keratoconus had significantly greater intereye asymmetry in all descriptors except for relational thickness indices. Intereye asymmetry in front elevation at the thinnest corneal location afforded the single highest diagnostic performance (71% sensitivity and 85% specificity), whereas the best multivariate model combining intereye asymmetry in anterior and posterior keratometry, corneal thickness, and front and back elevation at the thinnest point provided 65% sensitivity and 97% specificity. Multivariate models upheld their performance in the validation dataset. Most (more than 90%) indeterminate patients, according to conventional Pentacam analysis, showed within-normal-range corneal asymmetry.

CONCLUSIONS:

Healthy corneas are markedly symmetric irrespective of anisometropia, but corneal asymmetry analysis does not provide sufficient sensitivity to be used alone for detecting keratoconus. However, its remarkable specificity suggests that it could be used combined with conventional single cornea Pentacam analysis to reduce the false-positive rate or in dubious cases.

[
J Refract Surg
. 2015;31(2):116–123.]
Comparison of Higher-Order Aberration Induction Between Manual Microkeratome and Femtosecond Laser Flap Creation
Authors: Yvon Camille , Archer Timothy J. , Gobbe Marine , Reinstein Dan Z.
Published: March 2015

PURPOSE:

To compare the mean change in aberrations produced by a mechanical microkeratome and femtosecond laser.

METHODS:

This was a retrospective study of 62 consecutive near emmetropic eyes that underwent LASIK and satisfied the following criteria: negligible laser ablation (for spherical equivalent of 0.00 to +0.50 diopters and maximum meridian of +0.50 diopters), and preoperative and at least 3 months postoperative Placido-based corneal aberrometry (ATLAS; Carl Zeiss Meditec, Jena, Germany). Eyes were divided into two groups according to the method used for flap creation: mechanical microkeratome (Hansatome zero-compression microkeratome; Bausch & Lomb, Rochester, NY [mechanical microkeratome group]) or femtosecond laser (VisuMax; Carl Zeiss Meditec, Jena, Germany [femtosecond laser group]). The root mean square total and individual higher-order aberrations were compared between the two groups.

RESULTS:

Corneas with mechanical flaps, on average, possessed statistically significantly higher trefoil and horizontal coma (
P
< .001). There was no change in higher-order aberrations, except for spherical aberration in the femtosecond laser group. Average change in coma did not correlate with hinge position. Both groups showed statistically significant changes in spherical aberration (
P
< .001), although this was most likely due to the small hyperopic ablation performed.

CONCLUSIONS:

There was greater induction of specific aberrations with the microkeratome than the femtosecond laser. Hinge position did not appear to influence the induction of coma directly, contrary to previously published reports. The difference in aberrations induction between the two groups might be due to the differences in flap thickness profiles.

[
J Refract Surg
. 2015;31(2):130–135.]
Effects of light quality on reproduction, growth and pigment content of Gracilaria birdiae (Rhodophyta: Gracilariales)
Authors: Bonomi Barufi José , Figueroa Félix L. , Plastino Estela M.
Published: March 2015

Gracilaria species are the main source of agar worldwide. Since laboratory cultivation is an important means of sustaining such production, this study aimed to assess the influence of two fundamental strategies of physiological algae adjustment, photoacclimation and photomorphogenesis, on G. birdiae physiology. Specifically, the effects of different spectral light qualities on reproduction, growth, and pigment content in two distinct photoperiods (8 and 14 hours) were examined. Tetrasporophytes and gametophytes were submitted to different light qualities: white, green, red, and blue over the course of nine weeks. At the end of this period, chlorophyll a, allophycocyanin, phycocyanin, and phycoerythrin contents were analysed. Gametophytes showed reproductive structures only under monochromatic radiation. A stimulatory effect on tetrasporangium differentiation was mainly observed under red light, but this high fertility was negatively correlated with growth rate, i.e. algae cultivated under red light showed the lowest growth rate. However, while growth rates were higher in algae exposed to white light, they were similar to those observed in algae subjected to green light and 14 hours of daylight. PE was the predominant pigment, irrespective of light quality. Phycocyanin and phycoerythrin concentration increased when algae were cultivated under green and blue light. Therefore, considering future management prospects for G. birdiae mariculture, we suggest that red light could be utilized as a reproductive inductor to produce tetraspores. Furthermore, if the aim is to achieve high phycoerythrin content, continuous blue light could be applied during a short photoperiod. Indeed, the combination of different wavelengths could allow better economic resource exploitation.
Predicting the age of sardine juveniles (Sardina pilchardus) from otolith and fish morphometric characteristics
Authors: Silva Andreia V. , Meneses Isabel , Silva Alexandra
Published: March 2015

An age prediction model based on individual morphometric characteristics (total length; weight) and otolith morphometric characteristics (diameter; weight) was investigated for juvenile sardine, Sardina pilchardus (Walbaum, 1792). Juveniles were collected from northern Portugal between May 2004 and January 2005. Daily growth rings were counted on the otoliths of 114 juveniles of 7-16 cm total length. The sample was divided into a training sample used to develop the age prediction model and a test sample used to evaluate the predictive ability of the model. The best model for predicting the logarithm of age was a linear regression with otolith diameter. The prediction of daily age was more accurate for younger ( < 200 days) juveniles. Overall, ages predicted from the model were unbiased in relation to ages determined from otolith microincrement counts. Moreover, predicted daily ages reproduced the overall shape of the observed age distribution and provided comparable growth estimates (0.041 cm day–1). The back-calculated birthdate period ranged from 29 September 2003 to 22 July 2004, with a peak in January 2004, which is consistent with the spawning season. The model presented here could be used as a method for increasing the volume of juvenile daily age data. Since growth and survival varies spatially and temporally, relationships between age and otolith/fish morphometry should not be extrapolated outside sampled periods, areas and fish size/age.
Type I IFNs and IL-18 Regulate the Antiviral Response of Primary Human γδ T Cells against Dendritic Cells Infected with Dengue Virus
Authors: Tsai Chen-Yu , Liong Ka Hang , Gunalan Matilda Gertrude , Li Na , Lim Daniel Say Liang , Fisher Dale A. , MacAry Paul A. , Leo Yee Sin , Wong Siew-Cheng , Puan Kia Joo , Wong Soon Boon Justin
Published: March 2015

Little is known about the cellular mechanisms of innate immunity against dengue virus (DV) infection. Specifically, the γδ T cell response to DV has not been characterized in detail. In this article, we demonstrate that markers of activation, proliferation, and degranulation are upregulated on γδ T cells in PBMC isolated from individuals with acute dengue fever. Primary γδ T cells responded rapidly in vitro to autologous DV-infected dendritic cells by secreting IFN-γ and upregulating CD107a. The anti-DV IFN-γ response is regulated by type I IFN and IL-18 in a TCR-independent manner, and IFN-γ secreting γδ T cells predominantly expressed IL-18Rα. Antagonizing the ATP-dependent P2X7 receptor pathway of inflammasome activation significantly inhibited the anti-DV IFN-γ response of γδ T cells. Overnight priming with IL-18 produced effector γδ T cells with significantly increased ability to lyse autologous DV-infected dendritic cells. Monocytes were identified as accessory cells that augmented the anti-DV IFN-γ response of γδ T cells. Lack of monocytes in culture is associated with lower IL-18 levels in culture supernatant and diminished production of IFN-γ by γδ T cells, whereas addition of exogenous IL-18 restored the IFN-γ response of γδ T cells in monocyte-depleted cocultures with DV-infected DC. Our results indicate that primary γδ T cells contribute to the immune response during DV infection by providing an early source of IFN-γ, as well as by killing DV-infected cells, and suggest that monocytes participate as accessory cells that sense DV infection and amplify the cellular immune response against this virus in an IL-18–dependent manner.
Mechanical Thrombectomy with Rotarex System in Buerger's Disease
Authors: Kilickesmez Ozgur , Oguzkurt Levent
Published: March 2015

We report the case of a patient with 2-month history of chronic thromboembolism of the distal superficial femoral and popliteal arteries with diagnostic features of thromboangiitis obliterans disease. The occlusion could not be crossed by antegrade approach and was achieved retrogradely via dorsalis pedis artery puncture followed by mechanical removal of the thrombus with Rotarex system (Straub Medical AG, Wangs, Switzerland). Subsequent ballooon angioplasties achieved exclusion of the thrombus, and straight-line flow established to the foot through the anterior tibial Artery. The present case report demonstrates the success of mechanical thrombectomy in a patient with Buerger's vasculitis.
Almost Sure Global Well-posedness for the Fractional Cubic Schrödinger Equation on the Torus
Authors: Demirbas Seckin
Published: March 2015

In a previous paper, we proved that the 1-d periodic fractional Schrödinger equation with cubic nonlinearity is locally well-posed inHsfors> 1 −α/2 and globally well-posed fors> 10α− 1/12. In this paper we define an invariant probability measureμonHsfors<α− 1/2, so that for any ∊ > 0 there is a set Ω ⊂Hssuch thatμ(Ωc) <∊and the equation is globally well-posed for initial data in Ω. We see that this fills the gap between the local well-posedness and the global well-posedness range in an almost sure sense forin an almost sure sense.
Use of Shifted Laplacian Operators for Solving Indefinite Helmholtz Equations
Authors: Livshits Ira
Published: March 2015

A shifted Laplacian operator is obtained from the Helmholtz operator by adding a complex damping. It serves as a basic tool in the most successful multigrid approach for solving highly indefinite Helmholtz equations — a Shifted Laplacian preconditioner for Krylov-type methods. Such preconditioning significantly accelerates Krylov iterations, much more so than the multigrid based on original Helmholtz equations. In this paper, we compare approximation and relaxation properties of the Helmholtz operator with and without the complex shift, and, based on our observations, propose a new hybrid approach that combines the two. Our analytical conclusions are supported by two-dimensional numerical results.
Bootstrap Algebraic Multigrid: Status Report, Open Problems, and Outlook
Authors: Brandt Achi , Brannick James , Kahl Karsten , Livshits Ira
Published: March 2015

This paper provides an overview of the main ideas driving the bootstrap algebraic multigrid methodology, including compatible relaxation and algebraic distances for defining effective coarsening strategies, the least squares method for computing accurate prolongation operators and the bootstrap cycles for computing the test vectors that are used in the least squares process. We review some recent research in the development, analysis and application of bootstrap algebraic multigrid and point to open problems in these areas. Results from our previous research as well as some new results for some model diffusion problems with highly oscillatory diffusion coefficient are presented to illustrate the basic components of the BAMG algorithm.
Persistent after-effects of heavy rain on concentrations of ice nuclei and rainfall suggest a biological cause
Authors: Bigg E. K. , Soubeyrand S. , Morris C. E.
Published: March 2015

Abstract. Rainfall is one of the most important aspects of climate, but the extent to which atmospheric ice nuclei (IN) influence its formation, quantity, frequency, and location is not clear. Microorganisms and other biological particles are released following rainfall and have been shown to serve as efficient IN, in turn impacting cloud and precipitation formation. Here we investigated potential long-term effects of IN on rainfall frequency and quantity. Differences in IN concentrations and rainfall after and before days of large rainfall accumulation (i.e., key days) were calculated for measurements made over the past century in southeastern and southwestern Australia. Cumulative differences in IN concentrations and daily rainfall quantity and frequency as a function of days from a key day demonstrated statistically significant increasing logarithmic trends (R2 > 0.97). Based on observations that cumulative effects of rainfall persisted for about 20 days, we calculated cumulative differences for the entire sequence of key days at each site to create a historical record of how the differences changed with time. Comparison of pre-1960 and post-1960 sequences most commonly showed smaller rainfall totals in the post-1960 sequences, particularly in regions downwind from coal-fired power stations. This led us to explore the hypothesis that the increased leaf surface populations of IN-active bacteria due to rain led to a sustained but slowly diminishing increase in atmospheric concentrations of IN that could potentially initiate or augment rainfall. This hypothesis is supported by previous research showing that leaf surface populations of the ice-nucleating bacterium Pseudomonas syringae increased by orders of magnitude after heavy rain and that microorganisms become airborne during and after rain in a forest ecosystem. At the sites studied in this work, aerosols that could have initiated rain from sources unrelated to previous rainfall events (such as power stations) would automatically have reduced the influences on rainfall of those whose concentrations were related to previous rain, thereby leading to inhibition of feedback. The analytical methods described here provide means to map and delimit regions where rainfall feedback mediated by microorganisms is suspected to occur or has occurred historically, thereby providing rational means to establish experimental set-ups for verification.
Production of peroxy nitrates in boreal biomass burning plumes over Canada during the BORTAS campaign
Authors: Busilacchio M. , Di Carlo P. , Aruffo E. , Biancofiore F. , Salisburgo C. D. , Giammaria F. , Bauguitte S. , Lee J. , Moller S. , Hopkins J. , Punjabi S. , Andrews S. , Lewis A. C. , Parrington M. , Palmer P. I. , Hyer E.
Published: March 2015

Abstract. The observations collected during the BORTAS campaign in summer 2011 over Canada are analysed to study the impact of forest fire emissions on the formation of ozone (O3) and total peroxy nitrates (ΣPNs, ΣROONO2). The suite of measurements on board the BAe-146 aircraft, deployed in this campaign, allows us to calculate the production of O3 and of ΣPNs, a long lived O3 reservoir whose concentration is supposed to be impacted by biomass burning emissions. In fire plumes, profiles of carbon monoxide (CO), which is a well-established tracer of pyrogenic emission, show concentration enhancements that are in strong correspondence with a significant increase of ΣPNs concentrations, whereas minimal increase of the concentrations of O3 and NO2 are observed. In those fire plumes the average ΣPNs production is 12 times greater than in the background plumes, by contrast the average O3 production is only 5 times greater. These results suggest that, at least for boreal forest fires and for the measurements recorded during the BORTAS campaign, fire emissions impact both the oxidized NOy and O3, but: (1) ΣPNs production is affected significantly respect to the O3 production and (2) in the forest fire plumes the ratio between the ΣPNs production and the O3 production is lower than the ratio evaluated in the background air masses, thus confirming that the role played by the ΣPNs produced during biomass burning is significant in the O3 budget. These observations are consistent with elevated production of PAN and concurrent low production (or sometimes loss) of O3 observed in some another campaigns (i.e. ARCTAS-B) focused on forest fire emissions. Moreover our observations extend ARCTAS-B results since PAN is one of the compounds included in the ΣPNs family detected during BORTAS. The implication of these observations is that fire emissions in some cases, for example Boreal forest fires and in the conditions reported here, may influence more long lived precursors of O3 than short lived pollutants, which in turn can be transported and eventually diluted in a wide area. These observations provide additional indirect evidence that O3 production may be enhanced as plumes from forest fires age.
Constraining ecosystem carbon dynamics in a data-limited world: integrating ecological "common sense" in a model–data fusion framework
Authors: Bloom A. A. , Williams M.
Published: March 2015

Abstract. Many of the key processes represented in global terrestrial carbon models remain largely unconstrained. For instance, plant allocation patterns and residence times of carbon pools are poorly known globally, except perhaps at a few intensively studied sites. As a consequence of data scarcity, carbon models tend to be underdetermined, and so can produce similar net fluxes with very different parameters and internal dynamics. To address these problems, we propose a series of ecological and dynamic constraints (EDCs) on model parameters and initial conditions, as a means to constrain ecosystem variable inter-dependencies in the absence of local data. The EDCs consist of a range of conditions on (a) carbon pool turnover and allocation ratios, (b) steady-state proximity, and (c) growth and decay of model carbon pools. We use a simple ecosystem carbon model in a model–data fusion framework to determine the added value of these constraints in a data-poor context. Based only on leaf area index (LAI) time series and soil carbon data, we estimate net ecosystem exchange (NEE) for (a) 40 synthetic experiments and (b) three AmeriFlux tower sites. For the synthetic experiments, we show that EDCs lead to an overall 34% relative error reduction in model parameters, and a 65% reduction in the 3 yr NEE 90% confidence range. In the application at AmeriFlux sites all NEE estimates were made independently of NEE measurements. Compared to these observations, EDCs resulted in a 69–93% reduction in 3 yr cumulative NEE median biases (–0.26 to +0.08 kg C m−2), in comparison to standard 3 yr median NEE biases (–1.17 to −0.84 kg C m−2). In light of these findings, we advocate the use of EDCs in future model–data fusion analyses of the terrestrial carbon cycle.
Climate and land use change impacts on global terrestrial ecosystems and river flows in the HadGEM2-ES Earth system model using the representative concentration pathways
Authors: Betts R. A. , Golding N. , Gonzalez P. , Gornall J. , Kahana R. , Kay G. , Mitchell L. , Wiltshire A.
Published: March 2015

Abstract. A new generation of an Earth system model now includes a number of land-surface processes directly relevant to analyzing potential impacts of climate change. This model, HadGEM2-ES, allows us to assess the impacts of climate change, multiple interactions, and feedbacks as the model is run. This paper discusses the results of century-scale HadGEM2-ES simulations from an impacts perspective – specifically, terrestrial ecosystems and water resources – for four different scenarios following the representative concentration pathways (RCPs), used in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC, 2013, 2014). Over the 21st century, simulated changes in global and continental-scale terrestrial ecosystems due to climate change appear to be very similar in all 4 RCPs, even though the level of global warming by the end of the 21st century ranges from 2 °C in the lowest scenario to 5.5° in the highest. A warming climate generally favours broadleaf trees over needleleaf, needleleaf trees over shrubs, and shrubs over herbaceous vegetation, resulting in a poleward shift of temperate and boreal forests and woody tundra in all scenarios. Although climate related changes are slightly larger in scenarios of greater warming, the largest differences between scenarios arise at regional scales as a consequence of different patterns of anthropogenic land cover change. In the model, the scenario with the lowest global warming results in the most extensive decline in tropical forest cover due to a large expansion of agriculture. Under all four RCPs, fire potential could increase across extensive land areas, particularly tropical and sub-tropical latitudes. River outflows are simulated to increase with higher levels of CO2 and global warming in all projections, with outflow increasing with mean temperature at the end of the 21st century at the global scale and in North America, Asia, and Africa. In South America, Europe, and Australia, the relationship with climate warming and CO2 rise is less clear, probably as a result of land cover change exerting a dominant effect in those regions.
Does temperature affect the accuracy of vented pressure transducer in fine-scale water level measurement?
Authors: Liu Z. , Higgins C. W.
Published: March 2015

Abstract. Submersible pressure transducers have been utilized for collecting water level data since the early 1960s. Together with a digital data logger, it is a convenient way to record water level fluctuations for long-term monitoring. Despite the wide use of pressure transducers for water level monitoring, little has been reported regarding their accuracy and performance under field conditions. The effects of temperature fluctuations on the output of vented pressure transducers were considered in this study. The pressure transducers were tested under both laboratory and field conditions. The results of this study indicate that temperature fluctuation has a strong effect on the transducer output. Rapid changes in temperature introduce noise and fluctuations in the water level readings under a constant hydraulic head while the absolute temperature is also related to sensor errors. The former is attributed to venting and the latter is attributed to temperature compensation effects in the strain gauges. Individual pressure transducers responded differently to the thermal fluctuations in the same testing environment. In the field of surface hydrology, especially when monitoring fine-scale water level fluctuations, ignoring or failing to compensate for the temperature effect can introduce considerable error into pressure transducer readings. It is recommended that a performance test for the pressure transducer is conducted before field deployment.
Distribution patterns of salinity and 222Rn in Yatsushiro Inland Sea, Kyushu, Japan
Authors: Nikpeyman Y. , Ono N. , Hosono T. , Yang H. , Ichiyanagi K. , Shimada J. , Takikawa K.
Published: March 2015

Abstract. Submarine Groundwater Discharge (SGD), as a way through which solutes and nutrients travel from terrestrial areas towards coastal areas, is part of the hydrological cycle. Various methods are used to locate SGD at different scales. Among them, 222Rn has been developed with the viewpoint of accurate local estimations of SGD points indirectly. This research aims to identify SGD areas in the Yatsushiro Sea, southwest Japan, using the 222Rn method, while considering rivers with high 222Rn concentration in the study area. The area is an inland sea with high tidal fluctuations and there is a large contribution between the sea and groundwater, which are greatly affected by rivers. A multi-detector 222Rn survey has been carried out simultaneously with sea water electrical conductivity (EC) and temperature. In addition, several river grab samples were analysed for 222Rn concentration. Considering the sea water radon distribution and river characteristics, several points were selected for future SGD volume estimations.
Prediction of streamflow from the set of basins flowing into a coastal bay
Authors: De Lavenne A. , Cudennec C.
Published: March 2015

Abstract. Many coastal basins of the Brittany peninsula (France) display a high level of nitrate pollution, nine of them highlighted by the European Commission since 2007, as causing algal blooms in several coastal bays. To precisely diagnose and solve this issue the fluxes of every contributing basin have to be considered. However, this faces a strong data-scarce situation as most of the basins are ungauged. In this context, we propose to transpose hydrological information from one gauged basin to neighbouring points of interest. The methodology uses a simple geomorphology-based transfer function on the gauged basin, which allows assessment of the net rainfall time series through the de-convolution of the gauged discharge series. This net rainfall is then transposed and convoluted on the ungauged basin using its own transfer function in order to estimate discharge. This approach enables the quantification of the whole volume of freshwater entering the controversial Saint-Brieuc Bay.
Assessing the hydrological impacts of agricultural changes upstream of the Tunisian World Heritage sea-connected Ichkeul Lake
Authors: Aouissi J. , Chabaane Z. L. , Benabdallah S. , Cudennec C.
Published: March 2015

Abstract. The impact of changes in agricultural land use and practices as a controlling driver of hydrologic response and as a source of diffuse pollution, are studied in the Joumine River basin, discharging into the Ichkeul Lake, northern Tunisia, a UNESCO World Heritage site since 1979. The lake is characterized by a very specific hydrological functioning based on a seasonal alternation of water levels and salinity through its link to the Mediterranean Sea. Three Landsat images, in situ surveys and SWAT modelling were used to simulate and assess streamflows and nitrate loads under retrospective land uses.
Empirical quantification of lacustrine groundwater discharge – different methods and their limitations
Authors: Meinikmann K. , Nützmann G. , Lewandowski J.
Published: March 2015

Abstract. Groundwater discharge into lakes (lacustrine groundwater discharge, LGD) can be an important driver of lake eutrophication. Its quantification is difficult for several reasons, and thus often neglected in water and nutrient budgets of lakes. In the present case several methods were applied to determine the expansion of the subsurface catchment, to reveal areas of main LGD and to identify the variability of LGD intensity. Size and shape of the subsurface catchment served as a prerequisite in order to calculate long-term groundwater recharge and thus the overall amount of LGD. Isotopic composition of near-shore groundwater was investigated to validate the quality of catchment delineation in near-shore areas. Heat as a natural tracer for groundwater–surface water interactions was used to find spatial variations of LGD intensity. Via an analytical solution of the heat transport equation, LGD rates were calculated from temperature profiles of the lake bed. The method has some uncertainties, as can be found from the results of two measurement campaigns in different years. The present study reveals that a combination of several different methods is required for a reliable identification and quantification of LGD and groundwater-borne nutrient loads.
Annual layers in river-bed sediment of a stagnant river-mouth area of the Kitagawa Brook, Central Japan
Authors: Kurashige Y. , Nakano T. , Kasubuchi E. , Maruo M. , Domitsu H.
Published: March 2015

Abstract. The river mouth of Kitagawa Brook is normally stagnant because it is easily closed by sand and gravel transported by littoral currents of Biwa Lake, Japan. A new urban area exists in the basin and sewerage works were constructed in the early 1990s, so contaminated water with a bad odour had flowed into the brook before the sewerage works. To reduce the smell, the river mouth was excavated to narrow the channel in the early 1980s. Thus, river-bed sediment after this excavation only occurs at the river mouth. From the upper 24 cm of a sediment core, we found 19 strata of leaves which were supplied from deciduous trees in autumn. We also found several gravel layers which were supplied from the lake during severe storms. The combination of veins and gravel layers were reconstructed for about 20 years of sediment records with an error of two to three years.