bluuebunny/crossref_metadata_2025 huggingface dataset:
Une « illusion thérapeutique » ? Reconfigurations locales de la recherche clinique sur le VIH au Sénégal
Authors: Couderc Mathilde
Published: May 2013

Depuis 30 ans, les chercheurs en bioéthique s’intéressent aux frontières qui séparent la recherche thérapeutique d’une prise en charge clinique standard. Une notion majeure dans la littérature internationale à ce propos est celle de « therapeutic misconception » (« illusion thérapeutique » ou « malentendu thérapeutique » en français) qui recouvre la possibilité d’une confusion de la part des participants d’essais cliniques entre le domaine de la recherche et celui de la pratique de soins courante. L’ethnographie de trois essais thérapeutiques sur le VIH réalisés au Sénégal, associée à l’analyse de l’expérience des participants permettent d’interroger la pertinence de cette notion dans notre contexte d’étude. Si les études de cas montrent que la confusion existe, l’approche anthropologique montre qu’elle dépend surtout de facteurs structurels qui se distinguent des éléments sur lesquels s’appuient les théoriciens de ce concept ; et par là, que les propositions normatives élaborées par eux doivent considérer les contextes spécifiques où les recherches cliniques sont conduites.
Les effets microsociaux des antirétroviraux : prophylaxie de la transmission mère-enfant du VIH et individualisation au Burkina Faso
Authors: Desclaux Alice
Published: May 2013

L’extension de l’usage des antirétroviraux en Afrique visant l’éradication de la transmission du VIH pose la question des effets microsociaux du médicament : est-il vecteur d’individualisation et d’ empowerment , ou d’effets sociaux délétères pour les personnes ? Une étude menée au Burkina Faso auprès d’une population féminine a permis de comparer les effets de l’utilisation d’un médicament et ceux d’une stratégie comportementale de prévention de la transmission du VIH par l’allaitement. Les contraintes sociales qu’éprouvent les femmes qui appliquent la stratégie comportementale peuvent être évitées par la prise de médicament qui leur permet notamment de maintenir les pratiques usuelles en matière d’alimentation du nourrisson et de négocier à leur avantage l’annonce du statut VIH à des tiers (conjoint, entourage...). Médicament, individualisation et empowerment sont inscrits dans un rapport complexe ; le modèle d’individualisation sous-jacent au système de soins n’est pas toujours favorable aux femmes, alors que le médicament leur apporte une certaine autonomie.
La fidélité dans le couple et ses avatars
Authors: Bonnet Gérard
Published: May 2013

La fidélité est d’abord un idéal, dans lequel certaines personnes trouvent un plaisir privilégié et qui, comme tel, constitue un vecteur du désir. Cet idéal prend des proportions très différentes selon qu’il se présente comme un besoin narcissique, un avantage utilitaire ou une obligation sociale, mais il est vraiment efficace lorsqu’il constitue un idéal fondamental hérité des relations premières. Cela n’est possible qu’à certaines conditions telles que la référence au père, l’attachement à certains objets symboliques, la valorisation du lien pour lui-même. Les personnes souhaitant établir un lien de couple durable ont tout intérêt à rencontrer des personnes partageant le même idéal, en évitant de le projeter a priori en l’autre, ce qui risque d’en faire une source d’esclavage ou d’aliénation.
Désirable et exigeante. La régulation négociée des relations dans le couple et la famille
Authors: Bastard Benoit
Published: May 2013

Alors que la régulation négociée des interactions sociales est devenue un enjeu dans la société entière, la véritable extension de la contractualisation des relations interroge. Ne fait-elle pas l’impasse sur la permanence de déterminations sociales fortes ? Cet article s’intéresse à la contractualisation des fonctionnements conjugal et familial. Il montre que les relations entre conjoints (et ex-conjoints) sont marquées par une attente forte relative à la négociation du fonctionnement conjugal, mais qu’on ne peut en faire un modèle exclusif du couple et de la famille. De même, les instances de régulation sociale, si elles ne cessent d’exprimer leur préférence pour la contractualisation des relations de couple/famille, restent confrontées aux situations dans lesquelles ce sont d’autres formes de régulation des unions, moins démocratiques, qui prédominent et où il paraît vain de prétendre imposer aux conjoints de s’entendre.
Avons-nous besoin d'une union budgétaire en Europe ?
Authors: Kempf Hubert
Published: May 2013

Les difficultés actuelles de la zone euro ont relancé les discussions autour de la gouvernance de la zone euro et de l’opportunité d’une union budgétaire, c’est-à-dire un ensemble de règles collectives en matière budgétaire, en Europe. Dans cet article, nous rappelons que l’Union européenne connaît déjà une union budgétaire. Nous établissons une typologie simple des unions budgétaires et nous insistons sur l’un des dilemmes fondamentaux du choix, à savoir la gestion simultanée des chocs idiosyncrasiques naturels et des comportements opportunistes. Nous analysons les défauts majeurs de la construction monétaire européenne et nous énonçons cinq principes fondamentaux sur lesquels bâtir un fédéralisme budgétaire en Europe et assurer la pérennité de la monnaie européenne.
Le prêt à la création d'entreprises est-il efficace ?
Authors: Bastié Françoise , Cieply Sylvie
Published: May 2013

Le prêt à la création d’entreprises ( pce ) a été introduit en France en 2000 pour améliorer les conditions du financement des entreprises nouvellement créées. Cet article étudie l’influence de l’accès de ces entreprises à ce programme sur leur survie, leurs problèmes financiers et leur croissance perçue par leur dirigeant. D’après nos résultats, obtenus grâce à l’application d’un modèle de score de propension sur les données Sine, le pce n’exerce aucune influence sur la survie des entreprises. Il n’améliore pas non plus leur situation financière. En revanche, la croissance perçue par les dirigeants est supérieure lorsque l’entreprise bénéficie d’un pce relativement à la situation des entreprises sans crédit bancaire ni pce .
Croyances et goût pour la compétition
Authors: Berlin Noémi , Dargnies Marie-Pierre
Published: May 2013

Les travaux récents montrent que les hommes ont un goût pour la compétition plus prononcé que les femmes. Cet article présente un protocole expérimental mettant en évidence les différents déterminants du choix d’entrer en compétition : les croyances et le niveau de la compétition. Nous trouvons que les sujets peu performants s’adaptent au niveau de la compétition, ce qui n’est pas le cas des sujets performants. Notre expérience permet aussi de montrer que l’information n’est pas traitée de la même façon par les hommes et par les femmes : les femmes donnent plus de poids à l’information reçue, tandis que les hommes tiennent plus compte du niveau de la compétition auquel ils vont faire face. De manière générale, les hommes et les femmes dévient des croyances bayésiennes, et l’information sur leur performance les rend trop pessimistes si cette information est négative (trop optimiste dans le cas contraire).
Mesurer l'impact de l'effet partisan sur les réformes de corporate governance
Authors: Darcillon Thibault
Published: May 2013

Nous analysons, à l’aide d’un modèle logit en données de panel à effets fixes et d’un modèle de durée à événements répétés, la relation entre l’adoption de réformes de corporate governance visant à accroître les droits des actionnaires minoritaires au sein de la firme et l’affiliation partisane du gouvernement pour seize pays de l’ ocde sur une période de 1970 à 2009. Nous montrons notamment qu’un gouvernement de droite adoptera plus fréquemment des mesures favorables aux actionnaires minoritaires. Par ailleurs, l’hypothèse de compensation selon laquelle une augmentation du niveau de protection de l’emploi faciliterait l’adoption de telles mesures par des gouvernements de gauche ne semble pas se vérifier.
Rémunération des dirigeants et risque de fraude d'entreprise
Authors: Fleckinger Pierre , Lafay Thierry , Monnier Constance
Published: May 2013

Nous étudions la relation d’agence entre actionnaires et dirigeant d’une entreprise lorsqu’une action illégale est possible. Nous caractérisons en particulier la rémunération optimale proposée par la firme et son implication sur les décisions prises par le dirigeant. Ceci nous amène à évaluer si l’emploi de stock-options demeure ou non optimal dans ce contexte. Nous analysons en outre l’impact de ces schémas de rémunérations en termes de politique publique de lutte contre la fraude d’entreprise et nous montrons que le levier de la détection n’est pas interchangeable avec celui des amendes. Enfin, nous mettons en évidence que les acteurs ont des préférences divergentes quant à la politique publique de détection de ces pratiques illicites.
Accès aux services financiers et réduction de la pauvreté dans les PED
Authors: Kiendrebeogo Youssouf , Minea Alexandru
Published: May 2013

Nous utilisons des données issues d’enquêtes sur les ménages et auprès des organismes de réglementation bancaire, afin d’explorer l’impact de l’accès aux services financiers ( asf ) sur la pauvreté, sur un large échantillon de pays en développement. En contrôlant pour la présence d’un éventuel biais d’endogénéité à l’aide de la méthode des variables instrumentales, nous montrons que l’ asf réduit significativement la pauvreté. Ce résultat, qui est robuste à l’utilisation de mesures alternatives d’ asf ou de pauvreté, ainsi qu’à l’introduction de plusieurs variables de contrôle, milite en faveur d’une place primordiale pour l’ asf dans la conception des Stratégies de réduction de la pauvreté.
Complexité économique et croissance
Authors: Poncet Sandra , de Waldemar Felipe Starosta
Published: May 2013

Dans cet article, nous étudions l’effet de la complexité économique sur la croissance du revenu par tête des villes chinoises. Nous construisons une mesure de la complexité économique pour chaque ville en suivant la méthode des réflexions d’Hidalgo et Hausmann [2009]. Notre indicateur reflète la diversité et l’ubiquité de connaissances présentes dans la localité. Nos estimateurs portent sur un panel de 221 villes entre 1997 et 2009 et indiquent que plus une ville dispose d’une structure productive complexe, plus la croissance à venir de son pib par habitant est élevée.
Migration permanente, vente de terre et gestion informelle des risques de subsistance
Authors: Promsopha Gwendoline
Published: May 2013

Cet article traite de la vente des terres agricoles au sein d’une population de migrants permanents de l’exode rural en Thaïlande. L’impact de la transition structurelle sur les marchés fonciers d’achat/vente en milieu rural a en effet été peu étudié dans la littérature. À partir de données collectées dans la région de Bangkok, l’article teste alors l’impact potentiel de la fonction « filet de sécurité sociale » de la terre sur la décision des migrants de vendre ou, au contraire, de garder leurs terres. Les résultats indiquent que les ménages migrants les plus vulnérables vendent moins fréquemment leurs terres, afin de conserver une opportunité de retour et de bénéficier de la fonction « filet de sécurité sociale » offerte par la propriété foncière. Les résultats suggèrent ainsi des liens étroits entre la protection sociale des migrants et les réformes foncières dans des contextes de transition avec une forte émigration.
Trappes résultant d'externalités négatives dues à la répartition territoriale inégale des activités innovatrices
Authors: Ricci Francesco
Published: May 2013

The leader-follower model of Barro and Sala-i-Martin [1997] is modified by assuming that as the technological distance increases the productivity of R&D (i) in the follower region first increases then falls, and (ii) it falls in the leader region for extreme distance. The model predicts the possible emergence of two stable steady state equilibria. The economy can potentially get stuck in an equilibrium characterized by higher inter-regional inequality and a permanent common long-run growth rate below its potential. Free factors movement exacerbates this problem. Classification JEL  : R11, O30, O41, F43
Intensité de l’investissement privé en R&D dans les pays de l’OCDE
Authors: Montmartin Benjamin
Published: May 2013

Les aides financières à la R&D privée se sont multipliées depuis les années 1980 dans les pays de l’ ocde . Peu d’études mesurent l’impact macroéconomique de ces aides sur l’investissement privé en R&D. L’objectif de cet article est d’analyser l’effet individuel ainsi que la complémentarité interne et externe des aides directes et indirectes à la R&D privée. En utilisant une base de données couvrant vingt-cinq pays de l’ ocde sur la période 1990-2007, nos estimations en panel dynamique montrent que seules les aides indirectes influencent significativement l’intensité de la R&D privée. Si un effet de substitution apparaît entre les aides directes et les aides indirectes au sein d’un pays, une certaine complémentarité apparaît entre ces mesures internes et les mesures mises en place par d’autres pays.
Une estimation des coûts d'efficience des tarifs actuels des services publics de l'eau en France
Authors: Porcher Simon
Published: May 2013

Un résultat communément accepté dans la littérature sur la régulation des services publics (Coase [1946]) est que l’efficience du marché exige un recours à des tarifs binômes avec, d’une part, un prix marginal égal au coût marginal et, d’autre part, un prix fixe correspondant à la part de coûts fixes prise en charge par chaque abonné. En France, les usagers des services d’eau payent un prix marginal qui est en moyenne 8 % plus élevé que le coût marginal. Selon nos estimations de l’élasticité-prix, qui sont similaires à celles obtenues dans les précédentes études, les coûts d’efficience représentent une perte de près de 8 millions d’euros en 2008. Même si la distorsion demeure relativement faible, les consommateurs pourraient bénéficier de ces gains d’efficience.
Krachs financiers ou trappe à liquidité
Authors: Pottier Antonin , Giraud Gaël
Published: May 2013

Cet article examine les politiques monétaires non conventionnelles dans un modèle d’équilibre général à deux périodes. Les agents échangent, par l’intermédiaire de monnaie, des biens et également des actifs financiers collatéralisés. Une politique non conventionnelle d’augmentation de la quantité de monnaie entraîne l’existence de seulement trois scénarios compatibles avec les conditions d’équilibre : 1) l’économie rencontre une trappe à liquidité ; 2) la création monétaire rend possibles les échanges, au prix de l’inflation ; 3) la création monétaire alimente une bulle qui provoque un krach financier. Ce trilemme met en valeur les canaux de transmission des politiques monétaires aux échanges réels. Il donne une fondation rigoureuse à la distinction entre déflation fishérienne par la dette et trappe à liquidité keynésienne.
Estimación y modelización de arrastres de orgánico en acuoso (O/A) en pruebas de laboratorio de planta de extracción por solventes (SX) de cobre
Authors: Benavente O. , Hernández M. C. , Sagredo F.
Published: May 2013

Las pérdidas de orgánico a través de los arrastres (O/A) en la extracción por solventes implica una merma económica; por tal razón surge el interés de estimar el efecto que tienen tres oximas diferentes bajo distintas condiciones operacionales, además, modelizarlas en función de variables físico-químicas, de manera que se puedan predecir estas pérdidas. Las pruebas se realizan en un reactor Anetich en continuidad acuosa usando diluyente Orfom SX 12, con concentraciones de extractante de 10 %, 15 % y 20 %. Para la confección del modelo de medias se aplica un diseño factorial 2k a las pruebas. Los resultados indican que la cetoxima presenta en promedio un 40 % y 20 % menos arrastre que la aldoxima y la mezcla respectivamente. Además el modelo está dado por la ecuación Arrastre O/A = C - B * Temperatura - E * pH + F * Agitación; donde C, B, E y F son constantes específicas de cada reactivo.
Metodología para el cálculo de espesores límite libres de fase sigma durante el hipertemple en piezas de aceros dúplex de gran sección
Authors: Jimbert P. , Guraya T. , Torregaray A. , Bravo P.
Published: May 2013

Para conseguir las propiedades mecánicas y de corrosión deseadas en los aceros dúplex utilizados por la industria petro-química y nuclear se les somete a un tratamiento de hipertemple desde unos 1.050 °C. Con ello se evita el riesgo de aparición de precipitados intermetálicos que reducen drásticamente las propiedades de estos materiales. Sin embargo, al aumentar la profundidad a la que se encuentran los yacimientos actuales, los espesores para este tipo de canalizaciones se han visto incrementados, lo que se traduce en mayores niveles de exigencia sobre todo su proceso de fabricación, incluyendo el tratamiento térmico. Para evitar la precipitación de estas fases intermetálicas, como la fase sigma, es necesario conocer el perfil de enfriamiento en el centro de la pieza y para ello, conocer el valor del Coeficiente de Transferencia de Calor Superficial (h) es fundamental. Dicho coeficiente varía durante el hipertemple y su valor se determina experimentalmente ya que depende de varios parámetros del proceso. Diversos estudios demuestran que su valor se estabiliza a los pocos segundos, por lo que para conocer el perfil de enfriamiento en el centro de grandes secciones bastaría con conocer el valor estabilizado de h. Sin embargo, los estudios existentes en la literatura se refieren a diámetros menores de 100 mm. En el presente trabajo se ha desarrollado una metodología para predecir la precipitación de fases intermetálicas en piezas de acero dúplex con grandes espesores en instalaciones industriales a partir del cálculo de h. Esta metodología nos permite calcular los perfiles de enfriamiento sin sacrificar ninguna pieza, utilizando una o varias piezas patrón sensorizadas con termopares y una simulación posterior mediante ANSYS.
Decapado de un acero inoxidable austenítico mediante mezclas ecológicas basadas en H2O2 - H2SO4 - iones F-
Authors: Narváez L. , Miranda J. M. , Ronquillo A.
Published: May 2013

En este estudio se presenta el decapado del acero inoxidable austenítico 316L utilizando mezclas de peróxido de hidrógeno (H2O2)/ácido sulfúrico (H2SO4)/iones fluoruro; los iones fluoruro provienen del ácido fluorhídrico (HF), fluoruro de sodio (NaF) y fluoruro de potasio (KF). La estabilidad del H2O2 fue valorada modificando las concentraciones del ión férrico de 0 a 40 g/l y las temperaturas de 25 °C a 60 °C en las mezclas decapantes. Se establecieron las condiciones óptimas de decapado utilizando 20 g/l de iones férrico a 25 °C empleando el ácido p-toluensulfónico como estabilizante del H2O2. La mezcla que contenía HF fue la única capaz de eliminar completamente los óxidos superficiales del acero a tiempos de 300 s. Las mezclas a base de sales fluoradas eliminaron parcialmente los óxidos (20 y 40 % aprox.) en 300 s. Al incrementar el tiempo de decapado hasta 1200 s se obtuvieron porcentajes de eliminación alrededor de un 80 %.
Four new species of Pycnophyes (Kinorhyncha: Homalorhagida) from Korea and the East China Sea
Authors: Sánchez Nuria , Soo Rho Hyun , Min Won Gi , Kim Dongsung , Vinther Sørensen Martin
Published: May 2013

Four new species of Pycnophyes are described from Korean waters and the East China Sea. Pycnophyes pardosi n. sp. is distinguished from other congeners by the presence of a single paradorsal seta on segments 2-8 and a pair on segment 9, combined with the presence of longitudinal cuticular thickenings on the dorsal and ventral sides of segment 10. Pycnophyes chalgap n. sp. is easily distinguished by the shape of its midsternal plate with the rounded posterior margin, extending beyond and overlapping half of the following segment. Pycnophyes cristatus n. sp. is recognized by its lack of ventromedial setae on segments 3-6 combined with the presence of pointed middorsal processes that turn progressively longer towards the posterior segments from segment 6. The process on segment 10 is conspicuously long, extending beyond the posterior margin of segment 11. Pycnophyes smaug n. sp. is distinguished by its general scarcity of setae which, with the exception of those in lateroventral positions, only appear in laterodorsal positions on segments 2 and 9 and in ventromedial position on segment 9. The description of four additional species brings the total number of valid kinorhynch species around the Korean Peninsula up to 26.
Geometric Aspects of Spectral Theory
Authors: van den Berg Michiel , Grieser Daniel , Hoffmann-Ostenhof Thomas , Polterovich Iosif
Published: May 2013

The workshop “Geometric Aspects of Spectral Theory” brought together leading researchers working in various areas of this vast field of mathematics. The meeting featured presentations on some of the most fascinating recent developments in the subject, including five survey talks given by top experts, as well as reports on the progress made by graduate students and postdocs. A number of new stimulating questions were formulated during the open problem session.
Discrete Differential Geometry
Authors: Bobenko Alexander I. , Kenyon Richard , Schröder Peter , Ziegler Günter M.
Published: May 2013

This is the collection of extended abstracts for the 24 lectures and the open problems session at the third Oberwolfach workshop on Discrete Differential Geometry.
Geometric Group Theory, Hyperbolic Dynamics and Symplectic Geometry
Authors: Knieper Gerhard , Polterovich Leonid , Potyagailo Leonid
Published: May 2013

The workshop brought together experts in the young and rapidly developing mathematical fields of Geometric group theory, hyperbolic dynamics and symplectic geometry. The activities included talks on recent achievements and breakthroughs by world renowned mathematicians as well as graduate students and postdocs. The workshop witnessed many informal discussions between the participants, exchange of questions and conjectures and as one of the highlights an open problem session. A list of open problems is, besides of the extended abstracts of talks, contained in the present report.
Arithmetic Geometry
Authors: Faltings Gerd , de Jong Johan
Published: May 2013

The focus of the workshop was the connection between algebraic geometry and arithmetic. Most lectures were on p-adic topics, underlining the importance of Fontaine’s theory in the field, namely it gives a relation between “coherent” and “´etale” invariants. Lectures on other topics ranged from anabelian geometry to general algebraic geometry (although with number theoretic applications) and to results on global Shimura varieties.
Mathematical Aspects of Hydrodynamics
Authors: Constantin Peter , Friedlander Susan , Seregin Gregory A. , Titi Edriss S.
Published: May 2013

The workshop dealt with the partial differential equations that describe fluid motion, namely the Euler equations and the Navier-Stokes equations. Many of the lectures concerned questions of existence and regularity of solutions, possibly weak solutions, of these equations and somewhat simpler variants.
Low-Dimensional Topology and Number Theory
Authors: Gunnells Paul E. , Neumann Walter D. , Sikora Adam S. , Zagier Don B.
Published: May 2013

The workshop brought together topologists and number theorists with the intent of exploring the many tantalizing connections between these areas.
Scaling Limits in Models of Statistical Mechanics
Authors: Alexander Kenneth , Biskup Marek , van der Hofstad Remco , Sidoravicius Vladas
Published: May 2013

This has been the third workshop around Statistical Mechanics organized in the last 6 years. The main topic consisted of spatial random processes and their connections to statistical mechanics. The common underlying theme of the subjects discussed at the meeting is the existence of a
scaling limit
, i.e., a continuum object that approximates the discrete one under study at sufficiently large spatial scales. The specific topics that have been discussed included two-dimensional and high-dimensional critical models, random graphs and various random geometric problems, such as random interlacements, polymers, etc. The workshop bolstered interactions between groups of researchers in these areas and led to interesting and fruitful exchanges of ideas.
Singularities
Authors: Némethi András , van Straten Duco , Vassiliev Victor A.
Published: May 2013

Singularity theory is concerned with the local and global structure of maps and spaces that occur in algebraic, analytic or differential geometric context. It uses methods from algebra, topology, algebraic geometry and complex analysis.
Molecular Detection of Malaria at Delivery Reveals a High Frequency of Submicroscopic Infections and Associated Placental Damage in Pregnant Women from Northwest Colombia
Authors: Arango Eliana M. , Samuel Roshini , Agudelo Olga M. , Carmona-Fonseca Jaime , Maestre Amanda , Yanow Stephanie K.
Published: May 2013

Plasmodium infection in pregnancy causes substantial maternal and infant morbidity and mortality. In Colombia, both P. falciparum and P. vivax are endemic, but the impact of either species on pregnancy is largely unknown in this country. A cross-sectional study was carried out with 96 pregnant women who delivered at their local hospital. Maternal, placental, and cord blood were tested for malaria infection by microscopy and real-time quantitative polymerase chain reaction (qPCR). A high frequency of infection was detected by qPCR (45%). These infections had low concentrations of parasite DNA, and 79% were submicroscopic. Submicroscopic infections were associated with placental villitis and intervillitis. In conclusion, the overall frequency of Plasmodium infection at delivery in Colombia is much higher than previously reported. These data prompt a re-examination of the local epidemiology of malaria using molecular diagnostics to establish the clinical relevance of submicroscopic infections during pregnancy as well as their consequences for mothers and newborns.
Diagnosis of Schistosoma mansoni without the Stool: Comparison of Three Diagnostic Tests to Detect Schiostosoma mansoni Infection from Filtered Urine in Zambia
Authors: Lodh Nilanjan , Mwansa James C. L. , Mutengo Mable M. , Shiff Clive J.
Published: May 2013

Diagnosis for intestinal Schistosoma mansoni lacks sensitivity and is arduous to conduct. The standard diagnostic tests, Kato-Katz (KK) and circulating cathodic antigen (CCA) both lack sensitivity and with KK, require obtaining, transporting, and examining fresh stool. We compared diagnostic efficacy of KK, CCA, and polymerase chain reaction (PCR) to detect S. mansoni infection (species-specific DNA) from 89 filtered urine samples collected in Zambia. The PCR was the strongest indicator of positive cases with sensitivity and specificity of 100% in comparison to CCA (67% and 60%) and KK (50% and 100%). High positive and negative predictive values (100%) were also indicative of robustness of PCR. The same pattern was observed when stratified for sex and age group-specific analysis. Diagnosis of S. mansoni from filtered urine samples by PCR is an effective means to detect low intensity infection and would enhance the effectiveness of surveillance and control programs of schistosomiasis.
Land Aggregation Using Contingent and Guaranteed Payments
Authors: Zillante Arthur , Schwarz Peter M. , Read Dustin C.
Published: May 2013

This article explores the use of alternative payment mechanisms to overcome the holdout problem when multiple parcels of land must be acquired to complete a real‐estate development project. Purchase offers contingent upon successful land aggregation are compared to combination offers containing both guaranteed and contingent payments to determine which approach better mitigates holdout. The distribution of gains between developers and landowners is also examined. The results of a series of economic experiments suggest that contingent offers expedite land aggregation but developer payoffs are higher when combination offers are used. The results offer insight to real‐estate developers participating in land aggregation and inform government entities considering the necessity of public‐sector intervention in real‐estate markets to encourage desired development projects.
Debunking Health IT Usability Myths
Authors: Xiao Y. , Chapman L. , Staggers N.
Published: May 2013

Poor usability is a threat to patient safety and linked to productivity loss, workflow disruption, user frustration, sub-optimal product use and system de-installations. Although usability is receiving more attention nationally and internationally, myths about usability persist. This editorial debunks five common myths about usability (1) usability only concerns the look and feel of a product and is, therefore, only a minor concern, (2) usability is not measurable, (3) usability stifles innovation, (4) vendors are solely responsible for product usability, and (5) usability methods are not practical for use in healthcare.
Explantation and Rotation of Intracorneal Ring Segments with the Support of Femtosecond Laser: An Asymmetrical Version
Authors: Levinger E , Levinger S , Hirsh A
Published: May 2013

Purpose

To report a 25-year-old man who presented with advance keratoconus in the right eye with uncorrected visual acuity (UCVA) of 0.2 and best spectacle-corrected visual acuity (BSCVA) of 0.33 with +0.50 −9.25 × 45°.

Materials and methods

Clinical examination and corneal topography revealed grade III keratoconus in the right eye. Intracorneal ring segments (INTACS SK; Addition Technology, Des Plaines, IL) were implanted without surgical complications at 400 µm, with the 450 µm segments implanted superiorly and inferiorly using the femtosecond laser (Intralase®, Advanced Medical Optics, Inc, Abbott Park, IL).

Results

For 3 months postoperatively, BSCVA remained at 0.5 with plano −4.50 × 25°. The patient was complaining of foreign body sensation in the upper part of the eye and glare asking the surgeon to remove the two segments. The superior segment was removed and the lower segment was rotated 30° counter clockwise. Three months later, UCVA was 0.67 and remained stable for 24 months of follow-up.

Conclusion

This report shows that implanting the thicker segment inferiorly provides better visual results.

How to cite this article

Levinger E, Levinger S, Hirsh A. Explantation and Rotation of Intracorneal Ring Segments with the Support of Femtosecond Laser: An Asymmetrical Version. Int J Kerat Ect Cor Dis 2013;2(1):40-42.
Airborne observations of trace gases over boreal Canada during BORTAS: campaign climatology, airmass analysis and enhancement ratios
Authors: O'Shea S. J. , Allen G. , Gallagher M. W. , Bauguitte S. J.-B. , Illingworth S. M. , Le Breton M. , Muller J. B. A. , Percival C. J. , Archibald A. T. , Oram D. E. , Parrington M. , Palmer P. I. , Lewis A. C.
Published: May 2013

Abstract. In situ airborne measurements were made over Eastern Canada in summer 2011 as part of the BORTAS experiment (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and~Satellites). In this paper we present observations of greenhouse gases (CO2 and CH4) and other biomass burning tracers and related trace gases, both climatologically and through case studies, as recorded on board the FAAM BAe-146 research aircraft. Vertical profiles of CO2 were generally characterised by depleted boundary layer concentrations relative to the free troposphere, consistent with terrestrial biospheric uptake. In contrast, CH4 concentrations were found to rise with decreasing altitude due to strong local and regional surface sources. We use coincident tracer-tracer correlations and a Lagrangian trajectory model to characterise and differentiate air mass history of intercepted plumes. In particular, CO, HCN and CH3CN were used to identify air masses that have been recently influenced by biomass burning. Concentrations of CO2 were found to have a mean tropospheric, campaign-average concentration of 384.8 ppm (ranging between 371.5 and 397.1 ppm), whilst CH4 concentrations had a mean value of 1859 ppb (ranging between 1797 and 1968 ppb), representing the episodic sampling of local fire plumes. CH4 and CO2 concentrations during BORTAS were found to be broadly comparable to previous measurements in the region during the regional burning season and with reanalysed composition fields from the EU Monitoring Atmospheric Composition and Change (MACC) project. By examining individual case studies we were able to quantify emissions from biomass burning. Using both near-field (<1 day) and far-field (>1 day) sampling, boreal forest fire plumes were identified throughout the troposphere. Fresh plumes from fires in Northwest Ontario yield emission factors for CH4 and CO2 of 8.5 ± 0.9 g (kg dry matter)−1 and 1512 g ± 185 g (kg dry matter)−1, respectively. We have also investigated the efficacy of calculating emission factors from far-field sampling, in which there might be expected to be limited mixing with background and other characteristic air masses and we provide guidance on best practice and limitations in such analysis. We have found that for measurements within plumes that originated from fires in Northwest Ontario 2–4 days upwind, emission factors can be calculated that range between 1618 ± 216 and 1702 ± 173 g (kg dry matter)−1 for CO2 and 1.8 ± 0.2 and 6.1± 1 g (kg dry matter)−1 for CH4.
A novel inversion algorithm for mobility particle size spectrometers considering non-sphericity and additional aerodynamic/optical number size distributions
Authors: Pfeifer S. , Birmili W. , Schladitz A. , Müller T. , Nowak A. , Wiedensohler A.
Published: May 2013

Abstract. Multiple charge inversion is an essential procedure to convert the raw mobility distributions recorded by mobility particle size spectrometers, such as the DMPS or SMPS (Differential or Scanning Mobility Particle Sizers) into true particle number size distributions. In this work, we present a new multiple charge inversion algorithm with extended functionality. The algorithm can incorporate size distribution information from sensors that measure beyond the upper sizing limit of the mobility spectrometer, such as an aerodynamic particle sizer (APS), or an optical particle counter (OPC). This feature can considerably improve the multiple charge inversion result in the upper size range of the mobility spectrometer, for example, when substantial numbers of coarse particles are present. The program also yields a continuous size distribution from both sensors as an output. The algorithm is able to calculate the propagation of measurement errors, such as those based on counting statistics, into on the final particle number size distribution. As an additional aspect, the algorithm can perform all inversion steps under the assumption of non-spherical particle shape, including constant or size-dependent shape factor profiles.
A neural network-based estimate of the seasonal to inter-annual variability of the Atlantic Ocean carbon sink
Authors: Landschützer P. , Gruber N. , Bakker D. C. E. , Schuster U. , Nakaoka S. , Payne M. R. , Sasse T. , Zeng J.
Published: May 2013

Abstract. The Atlantic Ocean is one of the most important sinks for atmospheric carbon dioxide (CO2), but this sink is known to vary substantially in time. Here we use surface ocean CO2 observations to estimate this sink and the temporal variability from 1998 to 2007 in the Atlantic Ocean. We benefit from (i) a continuous improvement of the observations, i.e., the Surface Ocean CO2 Atlas (SOCAT) v1.5 database and (ii) a newly developed technique to interpolate the observations in space and time. In particular, we use a 2 step neural network approach to reconstruct basin-wide monthly maps of the sea surface partial pressure of CO2 (pCO2) at a resolution of 1° × 1°. From those, we compute the air–sea CO2 flux maps using a standard gas exchange parameterization and high-resolution wind speeds. The neural networks fit the observed pCO2 data with a root mean square error (RMSE) of about 10 μatm and with almost no bias. A check against independent time series data reveals a larger RMSE of about 17 μatm. We estimate a decadal mean uptake flux of –0.45 ± 0.15 Pg C yr–1 for the Atlantic between 44° S and 79° N, representing the sum of a strong uptake north of 18° N (–0.39 ± 0.10 Pg C yr–1), outgassing in the tropics (18° S–18° N, 0.11 ± 0.07 Pg C yr–1), and uptake in the subtropical/temperate South Atlantic south of 18° S (–0.16 ± 0.06 Pg C yr–1), consistent with recent studies. We find the strongest seasonal variability of the CO2 flux in the temperature driven subtropical North Atlantic, with uptake in winter and outgassing in summer. The seasonal cycle is antiphased in the subpolar latitudes relative to the subtropics largely as a result of the biologically driven winter-to-summer drawdown of CO2. Over the analysis period (1998 to 2007) sea surface pCO2 increased faster than that of the atmosphere in large areas poleward of 40° N, but many other parts of the North Atlantic increased more slowly, resulting in a barely changing Atlantic carbon sink north of the equator (–0.007 Pg C yr–1 decade–1). Surface ocean pCO2 was also increasing less than that of the atmosphere over most of the Atlantic south of the equator, leading to a substantial trend toward a stronger CO2 sink for the entire South Atlantic (–0.14 Pg C yr–1 decade–1). The Atlantic carbon sink varies relatively little on inter-annual time-scales (±0.04 Pg C yr–1; 1σ).
Improved light and temperature responses for light use efficiency based GPP models
Authors: McCallum I. , Franklin O. , Moltchanova E. , Merbold L. , Schmullius C. , Shvidenko A. , Schepaschenko D. , Fritz S.
Published: May 2013

Abstract. Gross primary production (GPP) is the process by which carbon enters ecosystems. Diagnostic models, based on the theory of light use efficiency (LUE) have emerged as one method to estimate ecosystem GPP. However, problems have been noted particularly when applying global results at regional levels. We hypothesize that accounting for non-linear light response and temperature acclimation of daily GPP in boreal regions will improve model performance. To test this hypothesis, we have chosen four diagnostic models for comparison, namely: an LUE model (linear in its light response) both with and without temperature acclimation and an LUE model and a big leaf model both with temperature acclimation and non-linear in their light response. All models include environmental modifiers for temperature and vapour pressure deficit (VPD). Initially, all models were calibrated against four eddy covariance sites within Russia for the years 2002–2004, for a total of 10 site years. Model evaluation was performed via 10-out cross-validation. This study presents a methodology for comparing diagnostic modeling approaches. Cross validation clearly demonstrates the improvement in model performance that temperature acclimation makes in modeling GPP at strongly temperature controlled sites in Russia. Additionally, the inclusion of a non-linear light response function is shown to further improve performance. Furthermore we demonstrate the parameterization of the big leaf model, incorporating environmental modifiers for temperature and VPD.
Depth-dependent molecular composition and photoreactivity of dissolved organic matter in a Boreal Lake under winter and summer conditions
Authors: Gonsior M. , Schmitt-Kopplin P. , Bastviken D.
Published: May 2013

Abstract. Transformations of dissolved organic matter (DOM) in boreal lakes lead to large greenhouse gas emissions as well as substantial carbon storage in sediments. Using novel molecular characterization approaches and photochemical degradation experiments we studied how seasonal patterns in water column stratification affected the DOM in a Swedish lake under late winter and early summer conditions. Dissolved organic carbon (DOC) concentrations were consistently higher above the sediment when compared to surface waters. Solely photobleaching could not explain this difference in DOC because the lake was covered by 40 cm thick ice during late winter sampling and still showed the same DOC trend. The differences in the molecular diversity between surface water DOM in winter and summer were consistent with summertime photobleaching/decarboxylation reactions and a possible bacterial consumption of photo-products. Additional photodegradation experiments using simulated sunlight showed a production of highly oxidized organic molecules and low molecular weight compounds in all late winter samples and also in the deep water sample in summer. In the surface summer DOM sample, few such molecules were produced during the photodegradation experiments confirming that DOM was already photobleached prior to the experiments. This study suggests that photobleaching, and therefore also the ice cover during winter plays a central role in surface DOM structural dynamics with important differences in the molecular composition of DOM between surface and deep boreal lake waters. The release of DOC from boreal lake sediments likely also contribute to this pattern. Photochemical degradation of DOM may be more extensive following ice-out and water column turnover when non-light exposed and thereby photosensitive DOM is photo-mineralized. Hence, the yearly DOM photo-mineralization may be greater than inferred from studies of recently light exposed DOM.
Long term soil moisture mapping over the Tibetan Plateau using Special Sensor Microwave/Imager
Authors: van der Velde R. , Salama M. S. , Pellarin T. , Ofwono M. , Ma Y. , Su Z.
Published: May 2013

Abstract. This paper discusses soil moisture retrievals over the Tibetan Plateau from brightness temperature (TB's) observed by the Special Sensor Microwave Imagers (SSM/I's) during warm seasons of the period from July 1987 to December 2008. The Fundamental Climate Data Record (FCDR) of F08, F11 and F13 SSM/I satellites by the Precipitation Research Group of Colorado State University is used for this study. A soil moisture retrieval algorithm is developed based on a radiative transfer model that simulates top-of-atmosphere TB's whereby effects of atmosphere are calculated from near-surface forcings obtained from a bias-corrected data set. Validation of SSM/I retrievals against in situ measurements for a two-and-half year period (225 matchups) gives a Root Mean Squared Error of 0.046 m3 m−3. The agreement between retrievals and Noah simulations from the Global Land Data Assimilation System (GLDAS) is investigated to further provide confidence in the reliability of SSM/I retrievals at the plateau-scale. Normalized soil moisture anomalies (N) are computed on an annual and monthly basis to analyze the trends present within the products available for July 1987 to December 2008. The slope of linear regression functions between N and time is used to quantify the trends. Both the annual and monthly N indicate severe wettings of 0.8 to almost 1.6 decade−1 in the center of the plateau. Correlations are found of the trend with elevation on an annual basis and for the months May, September and October. The observed wetting of the Tibetan Plateau agrees with recent findings of permafrost retreat, precipitation increase and potential evapotranspiration decline.
Temporary seismic monitoring of the Sulmona area (Abruzzo, Italy): quality study of microearthquake locations
Authors: Romano M. A. , de Nardis R. , Garbin M. , Peruzza L. , Priolo E. , Lavecchia G. , Romanelli M.
Published: May 2013

Abstract. Thanks to the installation of a temporary seismic network, a microseismicity study has been conducted in the Sulmona area (Abruzzo, Italy) with the aim of increasing the knowledge of seismogenic potential of existing active faults. In this work the first seven months (from 27 May to 31 December 2009) of recorded data have been analysed, over a total period of acquisition of about 30 months. Using a semi-automatic procedure, more than 800 local earthquakes has been detected, which highlight the background seismicity previously unknown. About 70% of these events have been relocated using a 1-D velocity model estimated specifically for the Sulmona area. Phase readings quality is checked and discussed, with respect to weighting schemes used by location algorithms, too. The integration of temporary network data with all the other data available in the region enable us to obtain a statistically more robust dataset of earthquake locations. Both the final hypocentral solutions and phase pickings are released as online Supplement. Local magnitude values of the newly detected events ranges between −1.5 and 3.7 and the completeness magnitude for the Sulmona area during the study period is about 1.1. Duration magnitude coefficients have been estimated as well, for comparison/integration purposes. Local Gutenberg–Richter relationship, estimated from the microseismic data, features low b value, possibly suggesting that the Sulmona area is currently undergoing high stress, in agreement with other recent studies. The time-space distribution of the seismic activity with respect to the known active faults, as well the seismogenic layer thickness, are preliminarily investigated.
Sediment transport on the inner shelf off Khao Lak (Andaman Sea, Thailand) during the 2004 Indian Ocean tsunami and former storm events: evidence from foraminiferal transfer functions
Authors: Milker Y. , Wilken M. , Schumann J. , Sakuna D. , Feldens P. , Schwarzer K. , Schmiedl G.
Published: May 2013

Abstract. We have investigated the benthic foraminiferal fauna from sediment event layers associated with the 2004 Indian Ocean tsunami and former storms, that have been retrieved in short sediment cores from offshore environments of the Andaman Sea, off Khao Lak, western Thailand. Species composition and test preservation of the benthic foraminiferal faunas exhibit pronounced changes across the studied sections and provide information on the depositional history of the tsunami layer, particularly on the source water depth of the displaced foraminiferal tests. In order to obtain accurate bathymetric information on sediment provenance, we have mapped the distribution of modern faunas in non-tsunamigenic surface sediments and created a calibration data set for the development of a transfer function. Our quantitative reconstructions revealed that the re-suspension of sediment particles by the tsunami wave was restricted to a maximum water depth of approximately 20 m. Similar values were obtained for former storm events, thus impeding an easy distinction of different high-energy events.
How to Measure Wear following Total Hip Arthroplasty
Authors: Grillini Laura , Affatato Saverio
Published: May 2013

Total hip arthroplasty has yielded excellent results in decreasing pain and enhancing function in patients with hip degenerative disease. However, the problems associated with prosthetic failure and the consequent need for revision surgery still represent a major clinical issue. The most common reasons for revision surgery include implant loosening, periprosthetic osteolysis, infection, malalignment, stiffness, implant failure or fracture, and wear. The need for eliminating or reducing wear plays a crucial role in refining prosthesis composition and design. In this regard, it is important to develop new techniques for more accurate and reproducible measurement of wear. This should allow earlier detection of increased wear and thus permit earlier identification of patients who are at risk, and also help to identify faulty implant designs.

This work is aimed at discussing the most common in vivo and in vitro methods used for evaluating the wear of hip prosthesis components.