655 research outputs found

    Convertisseur d'équations LATEX2Ink

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    International audienceDans cet article nous présentons un outil de génération de formules mathématiques manuscrites en ligne à partir d'une chaîne LATEX. Ce générateur permettra facilement de fabriquer à partir d'un corpus de référence d'expressions mathématiques une base de données qui sera annotée automatiquement au niveau symbole. Ainsi, à partir d'une base de symboles isolés, nous pouvons produire de façon pseudo-synthétique une formule mathématique quelconque par un placement et un dimensionnement stochastiques 2D de ces éléments. Nous montrons l'intérêt de cet outil dans le cadre d'un projet visant à la conception d'une méthode adaptée à la reconnaissance et à l'interprétation d'expressions mathématiques en-ligne

    Enumerating Isolated Cliques in Temporal Networks

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    Isolation is a concept from the world of clique enumeration that is mostly used to model communities that do not have much contact to the outside world. Herein, a clique is considered isolated if it has few edges connecting it to the rest of the graph. Motivated by recent work on enumerating cliques in temporal networks, we lift the isolation concept to this setting. We discover that the addition of the time dimension leads to six distinct natural isolation concepts. Our main contribution is the development of fixed-parameter enumeration algorithms for five of these six clique types employing the parameter "degree of isolation". On the empirical side, we implement and test these algorithms on (temporal) social network data, obtaining encouraging preliminary results

    Resolving Stellar Populations outside the Local Group: MAD observations of UKS2323-326

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    We present a study aimed at deriving constraints on star formation at intermediate ages from the evolved stellar populations in the dwarf irregular galaxy UKS2323-326. These observations were also intended to demonstrate the scientific capabilities of the multi-conjugated adaptive optics demonstrator (MAD) implemented at the ESO Very Large Telescope as a test-bench of adaptive optics (AO) techniques. We perform accurate, deep photometry of the field using J and Ks band AO images of the central region of the galaxy. The near-infrared (IR) colour-magnitude diagrams clearly show the sequences of asymptotic giant branch (AGB) stars, red supergiants, and red giant branch (RGB) stars down to ~1 mag below the RGB tip. Optical-near-IR diagrams, obtained by combining our data with Hubble Space Telescope observations, provide the best separation of stars in the various evolutionary stages. The counts of AGB stars brighter than the RGB tip allow us to estimate the star formation at intermediate ages. Assuming a Salpeter initial mass function, we find that the star formation episode at intermediate ages produced ~6x10^5 M_sun of stars in the observed region.Comment: 4 pages, 4 figures, Accepted for publication in A&A Letter

    Elaboration of a Novel Design Pirani Pressure Sensor for High Dynamic Range Operation and Fast Response Time

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    AbstractWe report a novel design for realizing Pirani sensor with a working range from a 1kPa up to pressure over than atmospheric one. The sensor is specifically designed to achieve high sensitivity, fast response time and high robustness. The proof of concept is composed of four metallic resistors interconnected to form a Wheatstone bridge. Two of them act simultaneously as the heating and sensing elements and the two others are used as a temperature reference. The heating element consists of a metallic wire of platinum Pt (3μm width, 1mm length) maintained on each lateral side by periodic silicon oxide SiO2 micro-bridges. The sensor design, fabrication technologies, electrical characterizations and voltage-pressure responses are described and shown. A future perspective is given, which describe the extension of this concept to elastic wave transduction of pressure using a combination of heater element and thin plate elastic waveguide

    Grey and white matter correlates of recent and remote autobiographical memory retrieval:Insights from the dementias

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    The capacity to remember self-referential past events relies on the integrity of a distributed neural network. Controversy exists, however, regarding the involvement of specific brain structures for the retrieval of recently experienced versus more distant events. Here, we explored how characteristic patterns of atrophy in neurodegenerative disorders differentially disrupt remote versus recent autobiographical memory. Eleven behavioural-variant frontotemporal dementia, 10 semantic dementia, 15 Alzheimer's disease patients and 14 healthy older Controls completed the Autobiographical Interview. All patient groups displayed significant remote memory impairments relative to Controls. Similarly, recent period retrieval was significantly compromised in behavioural-variant frontotemporal dementia and Alzheimer's disease, yet semantic dementia patients scored in line with Controls. Voxel-based morphometry and diffusion tensor imaging analyses, for all participants combined, were conducted to investigate grey and white matter correlates of remote and recent autobiographical memory retrieval. Neural correlates common to both recent and remote time periods were identified, including the hippocampus, medial prefrontal, and frontopolar cortices, and the forceps minor and left hippocampal portion of the cingulum bundle. Regions exclusively implicated in each time period were also identified. The integrity of the anterior temporal cortices was related to the retrieval of remote memories, whereas the posterior cingulate cortex emerged as a structure significantly associated with recent autobiographical memory retrieval. This study represents the first investigation of the grey and white matter correlates of remote and recent autobiographical memory retrieval in neurodegenerative disorders. Our findings demonstrate the importance of core brain structures, including the medial prefrontal cortex and hippocampus, irrespective of time period, and point towards the contribution of discrete regions in mediating successful retrieval of distant versus recently experienced events

    Evaluating signatures of glacial refugia for North Atlantic benthic marine taxa

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    A goal of phylogeography is to relate patterns of genetic differentiation to potential historical geographic isolating events. Quaternary glaciations, particularly the one culminating in the Last Glacial Maximum ;21 ka (thousands of years ago), greatly affected the distributions and population sizes of temperate marine species as their ranges retreated southward to escape ice sheets. Traditional genetic models of glacial refugia and routes of recolonization include these predictions: low genetic diversity in formerly glaciated areas, with a small number of alleles/ haplotypes dominating disproportionately large areas, and high diversity including ‘‘private’’ alleles in glacial refugia. In the Northern Hemisphere, low diversity in the north and high diversity in the south are expected. This simple model does not account for the possibility of populations surviving in relatively small northern periglacial refugia. If these periglacial populations experienced extreme bottlenecks, they could have the low genetic diversity expected in recolonized areas with no refugia, but should have more endemic diversity (private alleles) than recently recolonized areas. This review examines evidence of putative glacial refugia for eight benthic marine taxa in the temperate North Atlantic. All data sets were reanalyzed to allow direct comparisons between geographic patterns of genetic diversity and distribution of particular clades and haplotypes including private alleles. We contend that for marine organisms the genetic signatures of northern periglacial and southern refugia can be distinguished from one another. There is evidence for several periglacial refugia in northern latitudes, giving credence to recent climatic reconstructions with less extensive glaciation

    Estimation of genetic diversity and relationship in sugar beet pollinators based on SSR markers

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    Background: Genetic diversity studies are important for the selection of parents with a greater combination capacity that, when crossed, increase the chances of obtaining superior genotypes. Thus, 26 polymorphic simple sequence repeat (SSR) primers were used to assess the genetic diversity of 140 individual samples from 12 diploid sugar beet pollinators (pollen parents) and two cytoplasmic male sterile (cms) lines (seed parents). Eight pollinators originated from three research centers in the United States Department of Agriculture, while four pollinators and cms lines were from the Institute of Field and Vegetable Crops, Novi Sad, Serbia. Results: In total, 129 alleleswere obtained, with a mean of 3.2 alleles per SSR marker. The observed heterozygosity ranged from 0.00 to 0.87 (mean = 0.30). Expected heterozygosity and Shannon's information index were the lowest for marker BQ590934 and the highest for markers SB15s and FDSB502s; the same markers were the most informative, with PIC values of 0.70 and 0.69, respectively. Three private alleles were found in pollinator EL0204; two in pollinator C51; and one in pollinators NS1, FC221, and C93035. Molecular variance showed that 77.34% of the total genetic variation was attributed to intrapopulation variability. Cluster and correspondence analysis grouped sugar beet pollinators according to the breeding centers, with few exceptions, which indicate that certain amount of germplasm was shared, although centers had their own breeding programs. Conclusions: The results indicate that this approach can improve the selection of pollinators as suitable parental components and could further be applied in sugar beet breeding programs
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