No single, stable 3D representation can explain pointing biases in a spatial updating task

People are able to keep track of objects as they navigate through space, even when objects are out of sight. This requires some kind of representation of the scene and of the observer's location but the form this might take is debated. We tested the accuracy and reliability of observers' estimates of the visual direction of previously-viewed targets. Participants viewed 4 objects from one location, with binocular vision and small head movements then, without any further sight of the targets, they walked to another location and pointed towards them. All conditions were tested in an immersive virtual environment and some were also carried out in a real scene. Participants made large, consistent pointing errors that are poorly explained by any stable 3D representation. Any explanation based on a 3D representation would have to posit a different layout of the remembered scene depending on the orientation of the obscuring wall at the moment the participant points. Our data show that the mechanisms for updating visual direction of unseen targets are not based on a stable 3D model of the scene, even a distorted one

Assessing 2D visual encoding of 3D spatial connectivity

Introduction: When visualizing complex data, the layout method chosen can greatly affect the ability to identify outliers, spot incorrect modeling assumptions, or recognize unexpected patterns. Additionally, visual layout can play a crucial role in communicating results to peers.Methods: In this paper, we compared the effectiveness of three visual layouts—the adjacency matrix, a half-matrix layout, and a circular layout—for visualizing spatial connectivity data, e.g., contacts derived from chromatin conformation capture experiments. To assess these visual layouts, we conducted a study comprising 150 participants from Amazon’s Mechanical Turk, as well as a second expert study comprising 30 biomedical research scientists.Results: The Mechanical Turk study found that the circular layout was the most accurate and intuitive, while the expert study found that the circular and half-matrix layouts were more accurate than the matrix layout.Discussion: We concluded that the circular layout may be a good default choice for visualizing smaller datasets with relatively few spatial contacts, while, for larger datasets, the half- matrix layout may be a better choice. Our results also demonstrated how crowdsourcing methods could be used to determine which visual layouts are best for addressing specific data challenges in bioinformatics

IRIM at TRECVID 2013: Semantic Indexing and Instance Search

International audienceThe IRIM group is a consortium of French teams working on Multimedia Indexing and Retrieval. This paper describes its participation to the TRECVID 2013 semantic indexing and instance search tasks. For the semantic indexing task, our approach uses a six-stages processing pipelines for computing scores for the likelihood of a video shot to contain a target concept. These scores are then used for producing a ranked list of images or shots that are the most likely to contain the target concept. The pipeline is composed of the following steps: descriptor extraction, descriptor optimization, classiffication, fusion of descriptor variants, higher-level fusion, and re-ranking. We evaluated a number of different descriptors and tried different fusion strategies. The best IRIM run has a Mean Inferred Average Precision of 0.2796, which ranked us 4th out of 26 participants

Symmetry Energy II: Isobaric Analog States

Using excitation energies to isobaric analog states (IAS) and charge invariance, we extract nuclear symmetry coefficients, from a mass formula, on a nucleus-by-nucleus basis. Consistently with charge invariance, the coefficients vary weakly across an isobaric chain. However, they change strongly with nuclear mass and range from a_a~10 MeV at mass A~10 to a_a~22 MeV at A~240. Following the considerations of a Hohenberg-Kohn functional for nuclear systems, we determine how to find in practice the symmetry coefficient using neutron and proton densities, even when those densities are simultaneously affected by significant symmetry-energy and Coulomb effects. These results facilitate extracting the symmetry coefficients from Skyrme-Hartree-Fock (SHF) calculations, that we carry out using a variety of Skyrme parametrizations in the literature. For the parametrizations, we catalog novel short-wavelength instabilities. In comparing the SHF and IAS results for the symmetry coefficients, we arrive at narrow (+-2.4 MeV) constraints on the symmetry energy values S(rho) at 0.04<rho<0.13 fm^-3. Towards normal density the constraints significantly widen, but the normal value of energy a_a^V and the slope parameter L are found to be strongly correlated. To narrow the constraints, we reach for the measurements of asymmetry skins and arrive at a_a^V=(30.2-33.7) MeV and L=(35-70) MeV, with those values being again strongly positively correlated along the diagonal of their combined region. Inclusion of the skin constraints allows to narrow the constraints on S(rho), at 0.04<rho<0.13 fm^-3, down to +-1.1 MeV. Several microscopic calculations, including variational, Bruckner-Hartree-Fock and Dirac-Bruckner-Hartree-Fock, are consistent with our constraint region on S(rho).Comment: 101 pages, 27 figures, 2 tables; submitted to Nuclear Physics

Fibrillogenese und Mineralisierung in Knochen : quantitative Analyse und Auswirkungen auf die Gewebselastizität

Zsfassung in dt. SpracheExperimentelle Daten von Dehydrierungs-, Demineralisierung- und Deorganifizierungstests wurden über eine Zeitspanne von mehr als 80 Jahren gesammelt. Diese Ergebnisse weisen eine Unzahl an unterschiedlichen chemischen Kompositionen verschiedenster Knochenmaterialien auf. Nach Analyse dieser Daten, bei dem die chemischen Konzentrationen von Hydroxyapatit, Wasser und organischem Material (hauptsächlich Kollagen) in der extrazellulären Knochenmatrix extrahiert wurden, zeigen diese eine erstaunliche Tatsache: Es stellt sich heraus, dass eine eindeutige bilineare Beziehung zwischen der organischen und der mineralischen Konzentration existiert die gültig ist für unterschiedliche Spezien, Organe und Altersgruppen (von früher Kindheit bis Senilität): während dem Organwachstum steigt die Mineralkonzentration linear mit der organischen Konzentration (welche während der Fibrillogenese steigt), wohingegen die mineralische Konzentration während des Erwachsenenalters weiterhin ansteigt und mit einer Verminderung der organischen Konzentration begleitet wird. Diese Beziehungen implizieren ein eindeutiges Massendichte-Konzentrationen-Gesetz für Fibrillogenese und Mineralisierung, welche in Kombination mit einem Mikromechanik Modell eine "universelle" Massendichte-Elastizität-Beziehung in der extrazellulären Knochenmatrix aufweisen. Dies zeigt eine quantitative Reflektion des fein abgestimmten Zusammenspiels zwischen Osteoblasten, Osteoklasten, Osteozyten und deren Vorläuferzellen, welche die chemische Entstehung und durchgehende Transformation der extrazellulären Knochenmatrix kontrollieren. Betrachtungen der zuvor genannten Regeln können einen starken Einfluss auf den potentiellen Erfolg von Gewebszüchtungsstrategien haben, vor allem bei der Umsetzung der Wachstums- und Mineralisierungscharakteristiken in gewebsspezifische Elastizitätseigenschaften.Data from bone drying, demineralization, and deorganification tests, collected over a time span of more than eighty years, evidence a myriad of different chemical compositions of different bone materials.However, careful analysis of the data, as to extract the chemical concentrations of hydroxyapatite, of water, and of organic material (mainly collagen) in the extracellular bone matrix, reveals an astonishing fact: it appears that there exists a unique bilinear relationship between organic concentration and mineral concentration, across different species, organs, and age groups, from early childhood to senility: During organ growth, the mineral concentration increases linearly with the organic concentration (which increases during fibrillogenesis), while from adulthood on, further increase of the mineral concentration is accompanied by a decrease in organic concentration. These relationships imply unique mass density-concentration laws for fibrillogenesis and mineralization, which - in combination with micromechanical models - deliver 'universal' mass density-elasticity relationships in extracellular bone matrix - valid across different species, organs, and ages. They turn out as quantitative reflections of the well-instrumented interplay of osteoblasts, osteoclasts, osteocytes, and their precursors, controlling, in a fine-tuned fashion, the chemical genesis and continuous transformation of the extracellular bone matrix. Considerations of the aformentioned rules may strongly affect the potential success of tissue engineering strategies, in particular when translating, via micromechanics, the aformentioned growth and mineralization characteristics into tissue-specific elastic properties.11

Bone fibrillogenesis and mineralization: Quantitative analysis and implications for tissue elasticity

International audienceData from bone drying, demineralization, and deorganification tests, collected over a time span of more than eighty years, evidence a myriad of different chemical compositions of different bone materials. However, careful analysis of the data, as to extract the chemical concentrations of hydroxyapatite, of water, and of organic material (mainly collagen) in the extracellular bone matrix, reveals an astonishing fact: it appears that there exists a unique bilinear relationship between organic concentration and mineral concentration, across different species, organs, and age groups, from early childhood to OLD AGE : During organ growth, the mineral concentration increases linearly with the organic concentration (which increases during fibrillogenesis), while from adulthood on, further increase of the mineral concentration is accompanied by a decrease in organic concentration. These relationships imply unique mass density-concentration laws for fibrillogenesis and mineralization, which - in combination with micromechanical models - deliver 'universal' mass density-elasticity relationships in extracellular bone matrix - valid across different species, organs, and ages. They turn out as quantitative reflections of the well-instrumented interplay of osteoblasts, osteoclasts, osteocytes, and their precursors, controlling, in a fine-tuned fashion, the chemical genesis and continuous transformation of the extracellular bone matrix. Considerations of the aformentioned rules may strongly affect the potential success of tissue engineering strategies, in particular when translating, via micromechanics, the aformentioned growth and mineralization characteristics into tissue-specific elastic properties

Aktiekapitalet = Borgenärsskydd? - Med fokus på utdelningsreglerna

Det finns cirka 300 000 aktiebolag i Sverige. En ny aktiebolagslag trädde i kraft den 1 januari 2006. Anledningen till en ny aktiebolagslag är bland annat den internationella utvecklingen på det aktiebolagsrättsliga området. Det är vikigt att den svenska aktiebolagslagen framstår som konkurrenskraftigt i förhållande till övriga medlemsstater inom EU, samt att den är förenlig med EG-rätten. Utvecklingen på redovisningsområdet innebär en förskjutning i synsättet av hur tillgångar och skulder definieras samt när värdeöverföringar skall rapporteras i redovisningen. Syftet med dessa nya regler är att redovisningsinformationen ska fungera som ett bättre beslutsunderlag för investerare och andra intressenter. Det har dock befarats att de nya redovisningsreglerna som tillåter att värdering av tillgångar oftare sker till verkligt värde ger ökade möjligheter att dela ut orealiserade vinster. Synen på aktiekapitalet såsom ett sätt att skydda borgenärerna är en gammal kvarleva med rötter i den kontinentala rätten, vilken Sverige och stora delar av EU har valt att följa. Den anglosaxiska rättstraditionen lämnar dock istället det egna kapitalet öppet såsom en förhandlingsfråga mellan aktieägare och borgenärer. Ett skydd för borgenärerna kan alltså utformas på olika sätt. I Sverige tillämpas en rad olika metoder som samverkar med varandra, medan man utomlands tillämpas delvis andra metoder. Det uppstår dock problem när olika synsätt krockar med varandra, vilket är fallet vid olika former av regleringskonkurrens i kölvattnet av en ökad internationalisering. Detta är något EU har råkat ut för de senaste åren. Det är svårt att säga vilket system som bäst tillgodoser borgenärernas rätt, men det är också svårt att avgöra vem som bäst kan tillgodose borgenärernas skyddsbehov. Det är därmed svårt att avgöra ifall staten, branschorganisationer eller borgenärerna själva bör bli ansvariga för utformningen av skyddet. Syftet med uppsatsen är att skapa en översiktlig översyn av borgenärsskyddet i stort samt att undersöka de effekter som de nya ändringarna i ÅRL och ABL får för borgenärsskyddet. Fokus ligger på hur utdelningsfrågan hanteras, varför fördjupning sker kring dessa förändringar. Det kommer även att ske en utredning kring utvecklingen internationellt sett. Vi finner att uppsatsen har ett inslag av det hermeneutiska ställningstagandet då all information tolkats på nytt i takt med att vi samla in ny information och kunskap under uppsatsens gång. Vi har använt den kvalitativa intervjumetoden och genomfört intervjuer med välkända teoretiker och erfarna praktiker för att få en större insikt i ämnet. Utifrån vår litteraturgenomgång och intervjuer kan vi konstatera att aktiekapitalet inte utgör ett reellt borgenärsskydd eftersom det är så pass lågt ställt. Flera av våra respondenter hävdar att skyddet numera är så urholkat att lagstiftaren lika gärna kan gå över till det anglosaxiska systemet och ta bort kapitalkravet. I Europa tenderar kapitalkravet att försvinna mer och mer. Nyckelord: aktiebolagslagen, aktiekapital, borgenärsskydd, försiktighet, IASB, utdelning och reglering Vi har följande ämnestips till vidare forskning: Det skulle vara intressant att läsa en studie som undersöker hur företagen påverkas av den nya lagen. Mest intressant skulle vara att höra hur företagen tolkar lagens utdelningsutrymme och hur deras faktiska utdelningar påverkas. Det skulle också vara intressant att se hur debatten utvecklar sig de närmaste åren. En studie skulle som liknar den vi redan har utfört skulle vara en intressant uppföljning om några år för att se huruvida debatten har förts framåt och ändrat ramarna för utdelningsbart belopp

Comparative eye-tracking evaluation of scatterplots and parallel coordinates

We investigate task performance and reading characteristics for scatterplots (Cartesian coordinates) and parallel coordinates. In a controlled eye-tracking study, we asked 24 participants to assess the relative distance of points in multidimensional space, depending on the diagram type (parallel coordinates or a horizontal collection of scatterplots), the number of data dimensions (2, 4, 6, or 8), and the relative distance between points (15%, 20%, or 25%). For a given reference point and two target points, we instructed participants to choose the target point that was closer to the reference point in multidimensional space. We present a visual scanning model that describes different strategies to solve this retrieval task for both diagram types, and propose corresponding hypotheses that we test using task completion time, accuracy, and gaze positions as dependent variables. Our results show that scatterplots outperform parallel coordinates significantly in 2 dimensions, however, the task was solved more quickly and more accurately with parallel coordinates in 8 dimensions. The eye-tracking data further shows significant differences between Cartesian and parallel coordinates, as well as between different numbers of dimensions. For parallel coordinates, there is a clear trend toward shorter fixations and longer saccades with increasing number of dimensions. Using an area-of-interest (AOI) based approach, we identify different reading strategies for each diagram type: For parallel coordinates, the participants’ gaze frequently jumped back and forth between pairs of axes, while axes were rarely focused on when viewing Cartesian coordinates. We further found that participants’ attention is biased: toward the center of the whole plotfor parallel coordinates and skewed to the center/left side for Cartesian coordinates. We anticipate that these results may support the design of more effective visualizations for multidimensional data

The coordinated action of glucuronoyl esterase and α-glucuronidase promotes the disassembly of lignin–carbohydrate complexes

| openaire: EC/H2020/648925/EU//BHIVEGlucuronoxylans represent a significant fraction of woody biomass, and its decomposition is complicated by the presence of lignin–carbohydrate complexes (LCCs). Herein, LCCs from birchwood were used to investigate the potential coordinated action of a glucuronoyl esterase (TtCE15A) and two α-glucuronidases (SdeAgu115A and AxyAgu115A). When supplementing α-glucuronidase with equimolar quantities of TtCE15A, total MeGlcpA released after 72 h by SdeAgu115A and AxyAgu115A increased from 52% to 67%, and 61% to 95%, respectively. Based on the combined TtCE15A and AxyAgu115A activities, ~ 34% of MeGlcpA in the extracted birchwood glucuronoxylan was occupied as LCCs. Notably, insoluble LCC fractions reduced soluble α-glucuronidase concentrations by up to 70%, whereas reduction in soluble TtCE15A was less than 30%, indicating different tendencies to adsorb onto the LCC substrate.Peer reviewe

Evaluating viewpoint entropy for ribbon representation of protein structure

While many measures of viewpoint goodness have been proposed in computer graphics, none have been evaluated for ribbon representations of protein secondary structure. To fill this gap, we conducted a user study on Amazon’s Mechanical Turk platform, collecting human viewpoint preferences from 65 participants for 4 representative su- perfamilies of protein domains. In particular, we evaluated viewpoint entropy, which was previously shown to be a good predictor for human viewpoint preference of other, mostly non-abstract objects. In a second study, we asked 7 molecular biology experts to find the best viewpoint of the same protein domains and compared their choices with viewpoint entropy.\ud \ud Our results show that viewpoint entropy overall is a significant predictor of human viewpoint preference for ribbon representations of protein secondary structure. However, the accuracy is highly dependent on the complexity of the structure: while most participants agree on good viewpoints for small, non-globular structures with few secondary structure elements, viewpoint preference varies considerably for complex structures. Finally, experts tend to choose viewpoints of both low and high viewpoint entropy to emphasize different aspects of the respective structure