bluuebunny/crossref_metadata_2025 huggingface dataset:
Is inclusion of the occiput necessary in fusion for C1–2 instability in rheumatoid arthritis?
Authors: Werle Stephan , Ezzati Ali , ElSaghir Hesham , Boehm Heinrich
Published: November 2012

Object

The atlantoaxial joint is the location most and earliest affected in patients with rheumatoid arthritis (RA). In longstanding disease, ligamentous and osseous destruction can progress and involve all cervical segments. If surgical intervention is necessary, some prefer, to be safe, undertaking fusion to the occiput, whereas others advocate 1-level fusion of C1–2. Sparing the occiput (Oc)–C1 segment would allow retention of a considerable amount of physiological range of motion and seems beneficial against subaxial overload. Previous clinical studies on this topic have provided only nonspecific data after short-term follow-up, rendering a segment-sparing approach questionable.

The purpose of the present investigation was to assess long-term progression of inflammatory or degenerative destruction in the Oc–C1 segment after isolated C1–2 fusion for RA.

Methods

In a series of 113 consecutive patients with RA-related destruction restricted to the craniocervical junction, 14 individuals underwent Oc–C2 fusion and 99 underwent surgery exclusively at the C1–2 level. After a mean follow-up period of 9.4 years (range 4.9–14.7 years), 46 patients were available for clinical and radiographic examination, including CT imaging.

Results

None of the 46 patients needed additional surgery to extend the fusion to the occiput. Despite marked deterioration in the subaxial cervical spine, in general there were little or no changes in the atlantooccipital region. All but one patient presented with bony fusion of the fixed C1–2 level at follow-up.

Conclusions

The results of this investigation suggest that if the Oc–C1 joint is free of osseous destructions on conventional radiographs and free of abnormalities on MRI scans at the time of surgery (for transarticular fixation and fusion of C1–2), there is a very low risk for relevant destruction in the following 5–14 years. Thus, no prophylactic oligosegmental approach, but rather a segment-sparing monosegmental approach, is preferred, even in patients with high inflammatory levels.
Palaeolithic Big Game Hunting at HP766 in Wadi Umm Rahau, Northern Sudan
Authors: Gautier Achilles , Makowiecki Daniel , Paner Henryk , Van Neer Wim
Published: November 2012

HP766, discovered by the Gdansk Archaeological Museum Expedition (GAME) in the region immediately upstream the Merowe Dam in North Sudan and now under water, is one of the few palaeolithic sites with animal bone remains in the country. The archaeological deposits, the large size of the site, the lithics and the radiocarbon dates indicate occupation of a silt terrace of the Nile in late MSA and perhaps LSA times. Large and very large mammals predominate markedly among the recovered bone remains and it would seem that the palaeolithic hunters focused on such game. They could corner these animals on the site which is partially surrounded by high bedrock outcrops. Moreover swampy conditions of the site after the retreat of the annual Nile flood may have rendered less mobile the prey animals. According to this scenario, HP766 would testify to the ecological skills and generational memory of late prehistoric man in Sudan.
Typological and Interpretive Analysis of a 19th-Century Bead Cache in Coastal Kenya
Authors: Marshall Lydia Wilson
Published: November 2012

This article provides a typological and interpretive analysis of 3968 beads unearthed at Amwathoya, a late 19th-century Giriama homestead site in Kenya’s central coastal hinterland. These beads are predominantly imported glass specimens, and most were recovered from a single cache. The typological analysis of Amwathoya’s assemblage draws on both historical bead terms from 19th-century Eastern Africa and broader classificatory schemes developed by archaeologists in other world areas. Smaller glass bead assemblages from two nearby contemporaneous settlements are also examined for comparative purposes. The interpretive analysis of Amwathoya’s beads focuses on such ornaments’ potential role in the expression of cultural and gendered identities; the use of locally produced shell beads in divination and healing practices is also explored.
Punctum Saliens: Barthes, Mourning, Film, Photography
Authors: Badmington Neil
Published: November 2012

In the light of the publication of Roland Barthes's Mourning Diary (2009), this essay examines how the influential theory of the photographic punctum has cinematic roots which are repressed in Barthes's Camera Lucida (1980). My aim is not to repeat familiar arguments about how Barthes's ‘The Third Meaning’ (1970) anticipates the photographic punctum in a cinematic context; it is, rather, to attend specifically to Mourning Diary as a much closer, more precise precursor which has been visible only since 2009, and which casts new light upon the work of Roland Barthes.
Bachelard, Lacan and the Impurity of Scientific Formalization
Authors: Eyers Tom
Published: November 2012

This essay examines the conjunction of French historical epistemology and Lacanian theory in postwar France. In particular, Lacan's account of scientific formalization is scrutinized insofar as it develops aspects of the prior epistemological research of Gaston Bachelard, whose innovative approach to the problem of the nature and limits of scientific knowledge proved so influential on the subsequent field of French structuralism. Lacan's reflections on formalization will be shown, in contrast to Bachelard, to place an emphasis on the constitutive and limiting role of language in its interaction with logical and scientific projects. In asking how Lacan's structural psychoanalysis extends and subverts the rationalist emphasis of French philosophy of science, I hope to provide a new optic through which to assess the role of formalization in critical theory today.
Unwinding the Anthropological Machine: Animality, Film and Arnaud des Pallières
Authors: McMahon Laura
Published: November 2012

This article explores what cinema can contribute to recent philosophical engagements with animality and what the work of contemporary French filmmaker Arnaud des Pallières in particular can bring to debates around the zoomorphic or ‘creaturely’ dimensions of film. Examining two works by des Pallières — the documentary Is Dead (Incomplete Portrait of Gertrude Stein) (1999) and the feature-length film Adieu (2003) — and drawing principally on the work of Jacques Derrida, the article attends to cinematic, historically-framed configurations of a shared vulnerability between the human and the animal. Such instances of commonality are shown here to unravel hierarchical taxonomies of being, in a rethinking of the ethics and politics of responsibility. These nonanthropocentric modes of cinematic inquiry also engage with issues of minerality and technicity, animating correspondences between forms of life and nonlife, philosophically broadening a consideration of relations between the human and the nonhuman.
Surfaces: Painterly Illusion, Metaphysical Depth
Authors: Smith David Nowell
Published: November 2012

This essay analyses the way in which the relation between surface and depth in modern painting is endowed with philosophical significance in the work of Michel Foucault, Maurice Merleau-Ponty and Michel Henry. Whereas Foucault considered the work of Magritte and Manet to undermine the notion of depth as such, by showing the movement of ‘similitude’, Merleau-Ponty and Henry saw post-impressionist painting as engendering an experience of depth that exceeds the Cartesian model of space as res extensa. The motif of painterly surface thus brings into debate two significant movements in French twentieth-century thought: structuralism and phenomenology; in each case, the engagement with painterly technique becomes a way of grasping broader questions regarding the relation between perceptual experience and linguistic meaning.
Aging, Aerobic Activity and Interhemispheric Communication
Authors: McGregor Keith , Heilman Kenneth , Nocera Joe , Patten Carolynn , Manini Todd , Crosson Bruce , Butler Andrew
Published: November 2012

Recent studies have shown that during unimanual motor tasks, aging adults show bilateral recruitment of primary motor cortex (M1), while younger adults show a suppression of the ipsilateral motor cortex. Additional work has indicated that increased bilateral M1 recruitment in older adults may be deleterious when performing some motor tasks. However, higher levels of physical fitness are associated with improved dexterity and fitness may mitigate the loss of both inhibitory and excitatory communication in aging adults. The goal of this study was to assess dexterity and interhemispheric motor communication in physically fit and sedentary middle-age (40–60 years) right handed participants using tests of hand deftness and transcranial magnetic stimulation (TMS). To behaviorally assess the influence of interhemispheric communication on motor performance, participants also perform the coin rotation deftness task while maintaining pinch force with the opposite hand (bimanual condition). We correlated these behavioral measures with the ipsilateral silent period using TMS to assess interhemispheric inhibition. Our results show that the middle-aged adults who were physically fit had better dexterity of their right hand (finger tapping and peg-board). When performing the coin rotation task the fit group had no between hand differences, but the sedentary group’s left hand performance was inferior to the their right hand. We found that better dexterity correlated with ipsilateral silent period duration (greater inhibition) thereby supporting the postulate that fitness improves interhemispheric motor communication.
Structural Optimization Design of Horizontal-Axis Wind Turbine Blades Using a Particle Swarm Optimization Algorithm and Finite Element Method
Authors: Cai Xin , Zhu Jie , Pan Pan , Gu Rongrong
Published: November 2012

This paper presents an optimization method for the structural design of horizontal-axis wind turbine (HAWT) blades based on the particle swarm optimization algorithm (PSO) combined with the finite element method (FEM). The main goal is to create an optimization tool and to demonstrate the potential improvements that could be brought to the structural design of HAWT blades. A multi-criteria constrained optimization design model pursued with respect to minimum mass of the blade is developed. The number and the location of layers in the spar cap and the positions of the shear webs are employed as the design variables, while the strain limit, blade/tower clearance limit and vibration limit are taken into account as the constraint conditions. The optimization of the design of a commercial 1.5 MW HAWT blade is carried out by combining the above method and design model under ultimate (extreme) flap-wise load conditions. The optimization results are described and compared with the original design. It shows that the method used in this study is efficient and produces improved designs.
Mast Cells in the Pathogenesis of Multiple Sclerosis and Experimental Autoimmune Encephalomyelitis
Authors: Costanza Massimo , Colombo Mario , Pedotti Rosetta
Published: November 2012

Mast cells (MCs) are best known as key immune players in immunoglobulin E (IgE)-dependent allergic reactions. In recent years, several lines of evidence have suggested that MCs might play an important role in several pathological conditions, including autoimmune disorders such as multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), an animal model for MS. Since their first description in MS plaques in the late 1800s, much effort has been put into elucidating the contribution of MCs to the development of central nervous system (CNS) autoimmunity. Mouse models of MC-deficiency have provided a valuable experimental tool for dissecting MC involvement in MS and EAE. However, to date there is still major controversy concerning the function of MCs in these diseases. Indeed, although MCs have been classically proposed as having a detrimental and pro-inflammatory role, recent literature has questioned and resized the contribution of MCs to the pathology of MS and EAE. In this review, we will present the main evidence obtained in MS and EAE on this topic, and discuss the critical and controversial aspects of such evidence.
Nitric Oxide-Dependent Posttranslational Modification in Plants: An Update
Authors: Astier Jeremy , Lindermayr Christian
Published: November 2012

Nitric oxide (NO) has been demonstrated as an essential regulator of several physiological processes in plants. The understanding of the molecular mechanism underlying its critical role constitutes a major field of research. NO can exert its biological function through different ways, such as the modulation of gene expression, the mobilization of second messengers, or interplays with protein kinases. Besides this signaling events, NO can be responsible of the posttranslational modifications (PTM) of target proteins. Several modifications have been identified so far, whereas metal nitrosylation, the tyrosine nitration and the S-nitrosylation can be considered as the main ones. Recent data demonstrate that these PTM are involved in the control of a wide range of physiological processes in plants, such as the plant immune system. However, a great deal of effort is still necessary to pinpoint the role of each PTM in plant physiology. Taken together, these new advances in proteomic research provide a better comprehension of the role of NO in plant signaling.
Isolation and Structural Characterization of Lignin from Cotton Stalk Treated in an Ammonia Hydrothermal System
Authors: Kang Sumin , Xiao Lingping , Meng Lingyan , Zhang Xueming , Sun Runcang
Published: November 2012

To investigate the potential for the utilization of cotton stalk, ammonia hydrothermal treatment was applied to fractionate the samples into aqueous ammonia-soluble and ammonia-insoluble portions. The ammonia-soluble portion was purified to yield lignin fractions. The lignin fractions obtained were characterized by wet chemistry (carbohydrate analysis) and spectroscopy methods (FT-IR, 13C and 1H-13C HSQC NMR spectroscopy) as well as gel permeation chromatography (GPC). The results showed that the cotton stalk lignin fractions were almost absent of neutral sugars (0.43%–1.29%) and had relatively low average molecular weights (1255–1746 g/mol). The lignin fractions belonged to typical G-S lignin, which was composed predominately of G-type units (59%) and noticeable amounts of S-type units (40%) together with a small amount of H-type units (~1%). Furthermore, the ammonia-extractable lignin fractions were mainly composed of β-O-4' inter-unit linkages (75.6%), and small quantities of β-β' (12.2%), together with lower amounts of β-5' carbon-carbon linkages (7.4%) and p-hydroxycinnamyl alcohol end groups.
Wear Behavior of Fiber Laser Textured TiN Coatings in a Heavy Loaded Sliding Regime
Authors: Vandoni Laura , Demir Ali Gökhan , Previtali Barbara , Lecis Nora , Ugues Daniele
Published: November 2012

In heavy loaded mating components, such as sliders and sliding bearings, guaranteeing the efficiency of lubricant films for long times during severe service conditions is very complicated. In this work, the benefits deriving from the use of fiber laser sources for surface texturing of very thin TiN coatings in severe wear working conditions were demonstrated. Evaluations of the laser textured dimples shape, geometry and density are given. Wear performance of the fiber laser textured surfaces was evaluated in discontinuous oil lubricated conditions with a flat contact. High normal load and low sliding speed were applied. Comparison tests were also performed on commercial TiN and WC/C coatings. In terms of average wear volume and maximum wear depth, Laser Surface Texturing of TiN provided respectively a 70% and a 45% reduction if compared to plain TiN. If compared to WC/C the wear resistance gains were lower but LST TiN maintained such benefits for longer wear runs. SEM analysis also revealed that the laser interaction provided a localized thermal cracking to the TiN coating. However, the sliding action caused very limited and localized coating fragmentation or delamination.
Metabolic Adaptation and Protein Complexes in Prokaryotes
Authors: Krüger Beate , Liang Chunguang , Prell Florian , Fieselmann Astrid , Moya Andres , Schuster Stefan , Völker Uwe , Dandekar Thomas
Published: November 2012

Protein complexes are classified and have been charted in several large-scale screening studies in prokaryotes. These complexes are organized in a factory-like fashion to optimize protein production and metabolism. Central components are conserved between different prokaryotes; major complexes involve carbohydrate, amino acid, fatty acid and nucleotide metabolism. Metabolic adaptation changes protein complexes according to environmental conditions. Protein modification depends on specific modifying enzymes. Proteins such as trigger enzymes display condition-dependent adaptation to different functions by participating in several complexes. Several bacterial pathogens adapt rapidly to intracellular survival with concomitant changes in protein complexes in central metabolism and optimize utilization of their favorite available nutrient source. Regulation optimizes protein costs. Master regulators lead to up- and downregulation in specific subnetworks and all involved complexes. Long protein half-life and low level expression detaches protein levels from gene expression levels. However, under optimal growth conditions, metabolite fluxes through central carbohydrate pathways correlate well with gene expression. In a system-wide view, major metabolic changes lead to rapid adaptation of complexes and feedback or feedforward regulation. Finally, prokaryotic enzyme complexes are involved in crowding and substrate channeling. This depends on detailed structural interactions and is verified for specific effects by experiments and simulations.
Short Toxin-like Proteins Abound in Cnidaria Genomes
Authors: Tirosh Yitshak , Linial Itai , Askenazi Manor , Linial Michal
Published: November 2012

Cnidaria is a rich phylum that includes thousands of marine species. In this study, we focused on Anthozoa and Hydrozoa that are represented by the Nematostella vectensis (Sea anemone) and Hydra magnipapillata genomes. We present a method for ranking the toxin-like candidates from complete proteomes of Cnidaria. Toxin-like functions were revealed using ClanTox, a statistical machine-learning predictor trained on ion channel inhibitors from venomous animals. Fundamental features that were emphasized in training ClanTox include cysteines and their spacing along the sequences. Among the 83,000 proteins derived from Cnidaria representatives, we found 170 candidates that fulfill the properties of toxin-like-proteins, the vast majority of which were previously unrecognized as toxins. An additional 394 short proteins exhibit characteristics of toxin-like proteins at a moderate degree of confidence. Remarkably, only 11% of the predicted toxin-like proteins were previously classified as toxins. Based on our prediction methodology and manual annotation, we inferred functions for over 400 of these proteins. Such functions include protease inhibitors, membrane pore formation, ion channel blockers and metal binding proteins. Many of the proteins belong to small families of paralogs. We conclude that the evolutionary expansion of toxin-like proteins in Cnidaria contributes to their fitness in the complex environment of the aquatic ecosystem.
Modeling Problem-oriented Clinical Notes
Authors: de Vries Robbé P. F. , Cillessen F. H. J. M.
Published: November 2012

Objectives: To develop a model as a starting-point for developing a problem-oriented clinical notes application as a generic component of an Electronic Health Record (EHR).

Methods: We used the generic conceptualization of Weed’s problem-oriented medical record (POMR) to link progress notes to problems, and the Subjective, Objective, Assessment, Plan (SOAP) headings to classify elements of these notes. Health Level 7 (HL7) Version 3 and Unified Modeling Language (UML) were used for modeling. We looked especially at the role of Conditions and Concerns, and how to model these to document clinical reasoning.

Results: We developed a generic HL7-based model for progress notes. In this model the specific clinical note has a condition as its reason. An assertion can be made about a condition. Any condition, observation or procedure can be a concern that has to be tracked. Utmost important is the relationship between constituting parts of a progress note and specially between progress notes by linking a progress note to conditions that are part of an earlier progress note. From this model a comprehensive hierarchical condition tree can be built. Several views, such as chronological, SOAP and condition-oriented, are possible. The clinical notes application is used in daily clinical practice. The model meets explicit design criteria and clinical needs.

Conclusions: With the comprehensive HL7 standard it is possible to model and map progress notes using SOAP headings and POMR methodology. We have developed a generic, flexible and applicable paradigm by using acts for each assessment that refer to a condition (1), by separating conditions from concerns (2), and by an extensive use of the working list act (3).
Semantic Localization-driven Partial Image Retrieval in CT Series
Authors: Cavallaro A. , Kriegel H.-P. , Schubert M. , Petri M.
Published: November 2012

Background: Picture archiving and communication systems (PACS) contain very large amounts of computed tomography (CT) data. When querying a PACS for a particular series, the user is often not interested in the complete series but in a certain region of interest (ROI), described e.g. by an example view in another series or an anatomical concept.

Objectives: Restricting a retrieval query to such an ROI saves both loading time and navigational effort. In this paper, we propose an efficient method for defining and retrieving ROIs.

Methods: We employ interpolation and regression techniques for mapping the slices of a series to a newly generated standardized height atlas of the human body.

Results: Examinations of the accuracy and the saved input/output (I/O) costs of our new method on a repository of 1,360 CT series demonstrate the advantages of our system. Depending on the scope of the retrieval query, we can economize up to 99% of the total loading time.

Conclusion: Our proposed method for flexible, context-based, partial image retrieval enables the user to directly focus on the relevant portion of the image material and it targets the high potential of I/O cost reduction of a common PACS.
Towards a Personalized and Dynamic CRT-D
Authors: Santini L. , Forleo G. B. , Minni V. , Mafhouz K. , Della Rocca D. G. , Fresiello L. , Romeo F. , Ferrari G. , Di Molfetta A.
Published: November 2012

Background: In spite of cardiac resynchronization therapy (CRT) benefits, 25 – 30% of patients are still non responders. One of the possible reasons could be the non optimal atrioventricular (AV) and interventricular (VV) intervals settings. Our aim was to exploit a numerical model of cardiovascular system for AV and VV intervals optimization in CRT.

Methods: A numerical model of the cardiovascular system CRT-dedicated was previously developed. Echocardiographic parameters, Systemic aortic pressure and ECG were collected in 20 consecutive patients before and after CRT. Patient data were simulated by the model that was used to optimize and set into the device the intervals at the baseline and at the follow up. The optimal AV and VV intervals were chosen to optimize the simulated selected variable/s on the base of both echocardiographic and electrocardiographic parameters.

Results: Intervals were different for each patient and in most cases, they changed at follow up. The model can well reproduce clinical data as verified with Bland Altman analysis and T-test (p > 0.05). Left ventricular remodeling was 38.7% and left ventricular ejection fraction increasing was 11% against the 15% and 6% reported in literature, respectively.

Conclusions: The developed numerical model could reproduce patients conditions at the baseline and at the follow up including the CRT effects. The model could be used to optimize AV and VV intervals at the baseline and at the follow up realizing a personalized and dynamic CRT. A patient tailored CRT could improve patients outcome in comparison to literature data.
Variation of tibial plateau geometry and cruciate ligament coordinates in six breeds of dogs
Authors: Sabanci S. S. , Onar V. , Ocal M. K.
Published: November 2012

Objectives: The first aim of this study was to examine whether or not variations concerning the conformational characteristics of the proximal surface of the tibial plateau exist among six different dog breeds as well as within the same breed. The second aim of this study was to determine the coordinates of the cruciate ligaments.

Methods: One hundred and four tibias of 52 mature dogs from six different breeds were used. Photographs of the proximal surface of tibial plateau were taken, and measurements for the length, width and area of the tibial plateau, and the lateral and medial condyles were taken. In addition, the intercondylar width, height of Gerdy's tubercle, popliteal notch depth, and extensor groove depth were measured and recorded. The quotients from these measurements were calculated and compared amongst the dog breeds. The coordinates of the cruciate ligaments, according to the centre of tibial plateau, were also determined.

Results: Based on the calculated quotients, variations in the geometry of the tibial plateau geometry were common among the breeds. Within the same breed, on the other hand, length and width measurements of the tibial plateau were the least variable parameters among the other parameters examined. The cranial cruciate ligament was located in front of the surface centre of tibial plateau in all breeds. The position of cranial cruciate ligament was more variable in the craniocaudal direction than that observed in the mediolateral direction; this was the exact opposite of caudal cruciate ligament.

Clinical significance: The inter-breed variations of the quotients determined in the present study may facilitate attempts aimed to assess the risk factors of stifle joint injury and to design total knee prostheses.
Spinal fracture in a dog with diffuse idiopathic skeletal hyperostosis
Authors: Burger M. , Amort K. , Brunnberg L. , Kornmayer M.
Published: November 2012

A six-year-old, spayed female Weimaraner dog was first presented with the complaint of hindlimb paresis and then hindlimb paralysis two years later after colliding with a tree. Radiographs and computed tomography revealed spinal fractures at lumbar vertebrae (L)2-3 and at L4-5. In addition, the spinal column was affected by new bone formation along the vertebral bodies, bridging the disc spaces, as seen in diffuse idiopathic skeletal hyperostosis (DISH). Open reduction and internal fixation was achieved with standard vertebral body plating. This is the first report of DISH-associated spinal fractures after minor trauma in a dog. Surgery resulted in return of the full function after the first, and in improvement of neurologic function after the second incident.
From Psycho-Economics to Neuro-Economics
Authors: Walliser Bernard
Published: November 2012

Résumé En économie, trois niveaux d’organisation emboîtés - en l’occurrence comportemental, mental et neuronal - sont traditionnellement distingués. Ils introduisent des concepts théoriques ou observationnels spécifiques et proposent leurs propres modèles pour la prise de décision d’un individu. Si la psycho-économie relie les actions qu’il met en œuvre aux états mentaux qu’il affiche, la neuro-économie relie ses états mentaux aux zones actives de son cerveau. Sont ainsi définis des principes de pontage qui mettent en relation des concepts ayant une interprétation semblable et définis à deux niveaux successifs. Grâce à ces principes, des relations ou même des modèles suggérés indépendamment à deux niveaux adjacents peuvent être associés. Si quelques applications prescriptives de ces principes ont été plus récemment proposées, elles reposent encore sur une base conceptuelle très fragile. Classification JEL : A12, B41, D87.
Seeking Ambiguity: a Review on Neuroimaging Studies on Decision Making under Ambiguity
Authors: Taya Fumihiko
Published: November 2012

Résumé Les développements récents de l’imagerie cérébrale permettent d’envisager le réseau spécifique du cerveau qui est impliqué dans la prise de décision (Glimcher et al. 2004 ; Camerer 2008). L’un des domaines les plus intéressants est celui de « l’aversion à l’ambiguïté », situation dans laquelle les agents essaient d’éviter les configurations inconnues comme cela apparaît clairement dans le paradoxe d’Ellsberg. Même si l’aversion à l’ambiguïté est un phénomène qui a été abondamment observé, on sait que l’incertitude procédant plutôt d’une incomplétude de l’information se résout après obtention de l’information manquante, et les agents peuvent alors considérer les configurations ambiguës. Ici, nous nous proposons de recenser un grand nombre des études d’imagerie cérébrale consacrées à l’aversion à l’ambiguïté. Il a été démontré que la fonction affective du COF ainsi que la fonction cognitive du cortex préfrontal jouent un rôle déterminant dans la prise de décision sous incertitude. Nous commentons la mise en évidence des fonctions cognitives qui sont impliquées dans la prise de décision en présentant les contributions en imagerie cérébrale consacrées aux processus cognitifs de haut niveau. Classification JEL : D87.
Aversions to Trust
Authors: Corcos Anne , Pannequin François , Bourgeois-Gironde Sacha
Published: November 2012

Résumé Cet article met l’accent sur deux types d’aversion qui nous paraissent fondamentales dans la compréhension de la notion de confiance : l’aversion à la trahison (sociale) et l’aversion à l’ambiguïté (une catégorie particulière d’aversion à l’incertitude). À partir des études d’économie expérimentales et de neuroéconomie fondées sur le jeu de confiance, notre objectif vise principalement à évaluer les liens - d’ordres conceptuel, comportemental et neurobiologique - entre l’aversion à la trahison et l’aversion à l’ambiguïté. D’un point de vue psychologique individuel ou social, il semble bien que l’aversion générale vis-à-vis des signaux ambigus pourrait constituer le principal déterminant du comportement de confiance. Il s’agit de voir en quoi la confiance sociale apparaît comme un phénomène fondé sur l’aversion à l’incertitude. Plus précisément, selon notre approche, une réduction de l’incertitude ressentie pour l’interaction sociale favoriserait un climat de confiance propice à l’échange, en réduisant l’aversion à la trahison. Ainsi, tant l’aversion à la trahison que l’aversion à l’ambiguïté s’avèrent négativement corrélées avec la confiance. En se focalisant sur cette corrélation négative potentielle, notre approche se démarque nettement des approches de la confiance axées sur la notion d’altruisme Classification JEL : C72, C91, D03, D87.
Nuevos datos acerca de la fauna de áfidos de Costa Rica (Hemiptera, Aphididae)
Authors: Zamora Mejías D. , Pérez Hidalgo N. , Villalobos W. , Hanson P.
Published: November 2012

Los áfidos fueron colectados en 39 diferentes localidades en Costa Rica, sobre plantas nativas y cultivos, abarcando un amplio ámbito de altitud. En total, 48 especies de áfidos fueron identificadas, asociadas a 62 familias y 111 especies de plantas, varias representan nuevas asociaciones áfido-planta. Aphis nasturtii Kaltenbach, 1843 se cita por primera vez para América Central y Trichosiphonaphis (Xenomyzus) polygoni (van der Goot, 1917) por primera vez para Costa Rica. El total de especies de áfidos conocidas dentro del país se aumenta a 91, representando el 77,8% de todas las especies citadas en América Central
Estudio de la corrosión por bacterias sulfato-reductoras en la unión soldada de un acero API X-70
Authors: Flores J. E. , Patiño-Carachure C. , Alfonso I. , Rodríguez J. A. , Rosas G.
Published: November 2012

El comportamiento ante la corrosión, originada por bacterias sulfato-reductoras (SRB), fue estudiado en dos regiones de un tubo de acero soldado API X-70. Los estudios se enfocaron en el material base (BM) y la zona afectada térmicamente (HAZ), en la parte interna del tubo. Las SRB fueron extraídas del petróleo y cultivadas en un medio Postgate. El comportamiento a la corrosión fue evaluado a una temperatura de 60 °C, por periodos comprendidos entre 5 y 64 días. El análisis de las curvas de polarización potenciodinámicas, obtenidas por técnicas electroquímicas, indicó la activación de la superficie para tiempos cortos. La superficie fue caracterizada estructural y morfológicamente mediante microscopia electrónica de barrido (SEM), así como mediante microscopía óptica (OM). La concentración de H2S y el pH también fueron medidos. Los resultados mostraron un aumento importante de la corrosión para tiempos mayores a 20 días, lo cual fue influenciado por la actividad de las SRB, que guía a una concentración de H2S máxima (pH mínimo). Se encontró corrosión localizada en la HAZ en mayor cantidad que en el BM, así como la formación de una película delgada sobre la superficie del acero, originada por los productos de corrosión y la actividad bacteriana.
Deformación dinámica de aleaciones de magnesio coladas por inyección a alta presión
Authors: Dudamell N. V. , Gálvez F. , Pérez-Prado M. T.
Published: November 2012

El comportamiento dinámico de las aleaciones de magnesio Mg-6 % Al-0,5 % Mn y Mg-9 % Al-1 % Zn ha sido investigado en un amplio intervalo de temperaturas y se ha comparado con el comportamiento cuasi-estático. Se ha encontrado que, a altas velocidades de deformación estas aleaciones poseen alta capacidad de absorción de energía y que se mejora el maclado significativamente. Las pequeñas variaciones en la ductilidad a tracción a velocidades dinámicas se atribuyen a la independencia de de los mecanismos de cizalla adiabática de la distribución de la porosidad.
El comportamiento de la corrosión de los metales y aleaciones nanogranulados
Authors: Herrasti P. , Ponce de León C. , Walsh F. C.
Published: November 2012

En la última década ha habido un gran interes en las propiedades de materiales nanocristalinos. Estos materiales incluyen metales y aleaciones con un tamaño de cristal del orden de 1 a 100 nm. El interes por estos materiales es debido a las grandes diferencias en cuanto a sus propiedades electricas, opticas y magneticas, asi como a su alta capacidad de adsorción y reactividad química en relación a los mismos materiales con tamaños de grano mayores. En este trabajo se ha investigado y comparado la corrosión de materiales nano y microcristalinos de similar composición química. Principalmente se ha centrado en la corrosión de metales tales como niquel, cobre, cobalto y aleaciones de hierro. Se ha comprobado que los diferentes comportamientos frente al proceso de corrosión están intimamente ligados con los bordes de grano y el tamaño de dichos granos.
Survey of Bat Mortalities at a Wind-Energy Facility in North Dakota
Authors: Bicknell Lucas J. , Gillam Erin H.
Published: November 2012

In recent years, the wind-energy industry has rapidly expanded around the world, and studies assessing potential wildlife impacts have documented that bats are especially susceptible to injury and mortality near wind turbines. The rapid construction of many wind facilities in North Dakota, one of the states with the highest wind-energy potential, is of concern because little is known about the distribution and ecology of bats in North Dakota, and no research has assessed turbine-related impacts in the state. The objective of this research was to make preliminary assessments of bat fatalities at a wind facility in North Dakota. Six surveys were conducted at 12 turbines within an operational wind facility in South-central North Dakota from 25 July to 12 September 2010. In total, we discovered nine bat carcasses from two species. Although our data do not assess fatality rates, these findings do point to a need for future research on the impacts of the growing wind-energy industry in North Dakota.
Mathematics teachers’ reflective practice and the quality of their instruction.
Authors: Posthuma A. Barbara
Published: November 2012

Researchers and theorists differ whether teachers’ reflection on their classroom practices and teaching mathematics effectively are linked or not. This study aims to align the benefits of reflective practice with the quality of education and the learning of mathematics. A qualitative case study was conducted with five mathematics teachers at a high school in a rural area of the Free State. Data were collected by conducting interviews and observing lesson presentations. The reflective aspect was evaluated by employing Lee’s (2005) three levels of reflection – ‘recall level’, ‘rationalisation level’ and ‘reflective level’. The quality of the teachers’ mathematics instruction was compared to the principles for effective teaching set by Anthony and Walshaw (2009). The study found that there was indeed a link between the teachers’ reflective classroom practice and their effectiveness in facilitating the learning of mathematics. The teachers who were more reflective in the preparation and presentation of their lessons, were also evaluated to be more effective teachers than those who were less reflective. The results of the study have implications for the professional development of practising teachers – not only due to the fact that teachers should be trained and encouraged to reflect on their teaching and the learning of mathematics, but also because they have to discuss the effective teaching of mathematics cooperatively with their fellow teachers.
Gravity wave reflection and its influence on the consistency of temperature- and wind-based momentum fluxes simulated above Typhoon Ewiniar
Authors: Kim Y.-H. , Chun H.-Y. , Preusse P. , Ern M. , Kim S.-Y.
Published: November 2012

Abstract. For a case study of Typhoon Ewiniar performed with a mesoscale model, we compare stratospheric gravity wave (GW) momentum flux determined from temperature variances by applying GW polarization relations and by assuming upward propagating waves, with GW momentum flux calculated from model winds which is considered as a reference. The temperature-based momentum-flux profile exhibits positive biases relative to the reference, which fluctuate significantly with altitude. The vertically-averaged magnitude of the positive biases is about 14% of the reference momentum flux. We found that this deviation from the reference stems from the interference between upward and downward propagating waves. The downward propagating GWs are due mainly to partial reflections of upward propagating waves at altitudes where the background wind and stability change with height. When the upward and downward propagating waves are decomposed and their momentum fluxes are calculated separately from temperature perturbations, the fraction of the momentum flux arising from the downward propagating waves is about 4.5–8.2% of that from the upward propagating waves. The net momentum flux of upward and downward propagating GWs agrees well with the reference from the model wind perturbations. The implications of this study for the GW momentum-flux observations from satellites are discussed.
Mid-tropospheric δD observations from IASI/MetOp at high spatial and temporal resolution
Authors: Lacour J.-L. , Risi C. , Clarisse L. , Bony S. , Hurtmans D. , Clerbaux C. , Coheur P.-F.
Published: November 2012

Abstract. In this paper we retrieve atmospheric HDO, H2O concentrations and their ratio δD from IASI radiances spectra. Our method relies on an existing radiative transfer model (Atmosphit) and an optimal estimation inversion scheme, but goes further than our previous work by explicitly considering correlations between the two species. A global HDO and H2O a priori profile together with a covariance matrix were built from daily LMDz-iso model simulations of HDO and H2O profiles over the whole globe and a whole year. The retrieval parameters are described and characterized in terms of errors. We show that IASI is mostly sensitive to δD in the middle troposphere and allows retrieving δD for an integrated 3–6 km column with an error of 38‰ on an individual measurement basis. We examine the performance of the retrieval to capture the temporal (seasonal and short-term) and spatial variations of δD for one year of measurement at two dedicated sites (Darwin and Izaña) and a latitudinal band from −60° to 60° for a 15 day period in January. We report a generally good agreement between IASI and the model and indicate the capabilities of IASI to reproduce the large scale variations of δD (seasonal cycle and latitudinal gradient) with good accuracy. In particular, we show that there is no systematic significant bias in the retrieved δD values in comparison with the model, and that the retrieved variability is similar to the one in the model even though there are certain local differences. Moreover, the noticeable differences between IASI and the model are briefly examined and suggest modeling issues instead of retrieval effects. Finally, the results further reveal the unprecedented capabilities of IASI to capture short-term variations in δD, highlighting the added value of the sounder for monitoring hydrological processes.
Assessing the mineral dust indirect effects and radiation impacts on a simulated idealized nocturnal squall line
Authors: Seigel R. B. , van den Heever S. C. , Saleeby S. M.
Published: November 2012

Abstract. Mineral dust is arguably the most abundant aerosol species in the world and it plays a large role in aerosol indirect effects (AIEs). This study assesses and isolates the individual responses in a squall line that arise (1) from radiation, (2) from dust altering the microphysics, as well as (3) from the synergistic effects between (1) and (2). To accomplish these tasks, we use the Regional Atmospheric Modeling System (RAMS) set up as a cloud-resolving model (CRM). The CRM contains aerosol and microphysical schemes that allow mineral dust particles to nucleate as cloud drops and ice crystals, replenish upon evaporation and sublimation, be tracked throughout hydrometeor transition, and scavenge by precipitation and dry sedimentation. Factor separation is used on four simulations of the squall line in order to isolate the individual roles of radiation (RADIATION), microphysically active dust (DUST MICRO), and the nonlinear interactions of those factors (SYNERGY). Results indicate that RADIATION acts to increase precipitation, intensify the cold pool, and enhance the mesoscale organization of the squall line due to changes in microphysics beginning from cloud top cooling. Conversely, DUST MICRO decreases precipitation, weakens the cold pool, and weakens the mesoscale organization of the squall line due to an enhancement of the warm rain process. SYNERGY shows little impact on the squall line, except near the freezing level, where an increase in mesoscale organization takes place. The combined effect of the mineral dust AIE due to both DUST MICRO and SYNERGY is to weaken the squall line.
Estimating nitrogen fluxes at the European scale by upscaling INTEGRATOR model outputs from selected sites
Authors: Reinds G. J. , Heuvelink G. B. M. , Hoogland T. , Kros J. , de Vries W.
Published: November 2012

Abstract. A comparison was made between upscaled model results of nitrogen (N) fluxes to air and water from 450 sites within the EU-27 and results derived for the entire EU-27 area using the model INTEGRATOR. The 450 sites were selected using stratified random sampling, dividing the EU-27 into 150 strata and selecting three sites at random within each stratum. The strata were based on important environmental factors influencing N fluxes. Hierarchical divisive cluster analysis was used to reduce the numerous combinations of environmental factors to the required total of 150, such that the heterogeneity of environmental factors within strata was as small as possible. Modelled NH3, N2O and NOx emissions and N leaching/runoff obtained were scaled up from the 450 sites to the entire EU-27 and were within 10% of results obtained by running the model for the whole of the EU-27 using about 36 500 sites. This implies that a reliable estimate of N fluxes for EU-27 can be made by upscaling results of the 450 selected sites suggesting that dramatic reduction in computation time can be achieved without substantial deterioration of results
Abnormal quality detection and isolation in water distribution networks using simulation models
Authors: Nejjari F. , Pérez R. , Puig V. , Quevedo J. , Sarrate R. , Cugueró M. A. , Sanz G. , Mirats J. M.
Published: November 2012

Abstract. This paper proposes a model based detection and localisation method to deal with abnormal quality levels based on the chlorine measurements and chlorine sensitivity analysis in a water distribution network. A fault isolation algorithm which correlates on line the residuals (generated by comparing the available chlorine measurements with their estimations using a model) with the fault sensitivity matrix is used. The proposed methodology has been applied to a District Metered Area (DMA) in the Barcelona network.
A simple approach to providing a more consistent Arctic sea ice extent time series from the 1950s to present
Authors: Meier W. N. , Stroeve J. , Barrett A. , Fetterer F.
Published: November 2012

Abstract. Observations from passive microwave satellite sensors have provided a continuous and consistent record of sea ice extent since late 1978. Earlier records, compiled from ice charts and other sources exist, but are not consistent with the satellite record. Here, a method is presented to adjust a compilation of pre-satellite sources to remove discontinuities between the two periods and create a more consistent combined 59-yr time series spanning 1953–2011. This adjusted combined time series shows more realistic behavior across the transition between the two individual time series and thus provides higher confidence in trend estimates from 1953 through 2011. The long-term time series is used to calculate linear trend estimates and compare them with trend estimates from the satellite period. The results indicate that trends through the 1960s were largely positive (though not statistically significant) and then turned negative by the mid-1970s and have been consistently negative since, reaching statistical significance (at the 95% confidence level) by the late 1980s. The trend for September (when Arctic extent reaches its seasonal minimum) for the satellite period, 1979–2011 is −12.9% decade−1, nearly double the 1953–2011 trend of −6.8% decade−1 (percent relative to the 1981–2010 mean). The recent decade (2002–2011) stands out as a period of persistent decline in ice extent. The combined 59-yr time series puts the strong observed decline in the Arctic sea ice cover during 1979–2011 in a longer-term context and provides a useful resource for comparisons with historical model estimates.
Impedance Control and its Effects on a Humanoid Robot Playing Table Tennis
Authors: Xiong Rong , Sun Yichao , Zhu Qiuguo , Wu Jun , Chu Jian
Published: November 2012

This paper proposes an impedance control scheme used on humanoid robots for stability maintenance when the robot is expected to carry out fast manipulatory tasks. We take table tennis playing as an example to study this issue. The fast acceleration required by table tennis rallying will result in an unknown large reaction force on the robot, causing the body to swing back and forth in an oscillating motion and the foot to lose complete contact with the ground. To improve the stability during fast manipulation and in order to resist disturbances due to the reaction force, we introduce impedance control to absorb the impact and decrease the amplitude of body swinging. The system's adjusting time is also reduced and the oscillations are eliminated according to the experimental results, which show the effectiveness of our scheme.