2,962 research outputs found

    Retroviral Danger from Within: TLR7 Is in Control

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    In this issue of Immunity, Yu et al. (2012) outline a fascinating model in which TLR7-mediated antibody production acts as a dominant immunosurveillance mechanism against endogenous retroviruses (ERVs), with additional support of TLR3 and TLR9 that function to prevent ERV-mediated malignancy

    Hazai szárazföldi ászkarákfajok (Isopoda, Oniscidea) tipizálása két nagyváros, Budapest és Baltimore (ÉK Amerika) összehasonlításának példájával

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    Munkánkban kísérletet tettünk az ászkarákfajok természetvédelmi szempontú felosztására jellemző élőhelyük és elterjedési adataik alapján. Kategóriáink: természetközeli élőhelyeken élő NR („natural-rare”), kis abundanciával jellemezhető fajok; NF („natural-frequent”) természetközeli élőhelyeken, gyakori fajok; DR („disturbed-rare”) – zavart élőhelyeken, kis egyedszámban előfordulók; DF („disturbed- frequent”) – antropogén habitatok nagy abundanciájú, rendszerint szünantróp fajai; G („generalist”) – minden típusú élőhelyen előfordulható fajok; U („uncertain”) – kevés adat miatt nem tipizálhatóak. Ezen beosztás alapján az utóbbi években faunánkra újként kimutatott fajok kétharmada a DR kategóriába tartozik, ami az idegen faunaelemek felgyorsult betelepülését, a biodiverzitás homogenizálódó tendenciáját igazolja. Baltimore (ÉK Amerika) és Budapest Isopoda faunáját összevető esettanulmányunkban kimutattuk, hogy míg a vizsgált tengeren túli fauna 11 behurcolt fajból áll, addig Budapesten összesen 27 fajból, aminek 33%-a betelepült

    Extensible Component Based Architecture for FLASH, A Massively Parallel, Multiphysics Simulation Code

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    FLASH is a publicly available high performance application code which has evolved into a modular, extensible software system from a collection of unconnected legacy codes. FLASH has been successful because its capabilities have been driven by the needs of scientific applications, without compromising maintainability, performance, and usability. In its newest incarnation, FLASH3 consists of inter-operable modules that can be combined to generate different applications. The FLASH architecture allows arbitrarily many alternative implementations of its components to co-exist and interchange with each other, resulting in greater flexibility. Further, a simple and elegant mechanism exists for customization of code functionality without the need to modify the core implementation of the source. A built-in unit test framework providing verifiability, combined with a rigorous software maintenance process, allow the code to operate simultaneously in the dual mode of production and development. In this paper we describe the FLASH3 architecture, with emphasis on solutions to the more challenging conflicts arising from solver complexity, portable performance requirements, and legacy codes. We also include results from user surveys conducted in 2005 and 2007, which highlight the success of the code.Comment: 33 pages, 7 figures; revised paper submitted to Parallel Computin

    Sparse 3D Point-cloud Map Upsampling and Noise Removal as a vSLAM Post-processing Step: Experimental Evaluation

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    The monocular vision-based simultaneous localization and mapping (vSLAM) is one of the most challenging problem in mobile robotics and computer vision. In this work we study the post-processing techniques applied to sparse 3D point-cloud maps, obtained by feature-based vSLAM algorithms. Map post-processing is split into 2 major steps: 1) noise and outlier removal and 2) upsampling. We evaluate different combinations of known algorithms for outlier removing and upsampling on datasets of real indoor and outdoor environments and identify the most promising combination. We further use it to convert a point-cloud map, obtained by the real UAV performing indoor flight to 3D voxel grid (octo-map) potentially suitable for path planning.Comment: 10 pages, 4 figures, camera-ready version of paper for "The 3rd International Conference on Interactive Collaborative Robotics (ICR 2018)

    Code of Good Practices on Fiscal Transparency

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    Der von IWF entwickelte Code of Good Practices on Fiscal Transparency soll für eine umfassende Information der Öffentlichkeit über den Aufbau und die Aufgaben der Regierungen, die fiskalischen Ziele und die öffentlichen Haushalte sorgen. Die durch den Verhaltenskodex geforderte Transparenz in der Geld- und Finanzpolitik ist für Caio K. Koch-Weser, Bundesministerium der Finanzen, nicht nur eine elementare Voraussetzung für eine demokratische Kontrolle, sondern ist vor allem vor dem Hintergrund der zunehmenden Globalisierung und der wirtschaftspolitischen Überwachungsfunktion des IWF von Bedeutung. Für Deutschland stehe die Notwendigkeit fiskalischer Transparenz im Rahmen der Europäischen Wirtschafts- und Währungsunion, insbesondere des Stabilitäts- und Wachstumspaktes, und der damit erforderlichen finanzpolitischen Koordinierung im Blickpunkt. Für Dr. Dietmar Hornung, DEKABank, Frankfurt, kann die Implementierung von Standards und Codes dazu beitragen, die Belastbarkeit der Informationen zu steigern und so die Stabilität sowohl des politischen Prozesses zu fördern als auch die Volatilität der Kapitalmärkte zu dämpfen: "Empirische Untersuchungen bestätigen in der Tat den Zusammenhang zwischen fiskalischer Transparenz und fiskalischer Performance. … eine höhere fiskalische Transparenz (geht) im Regelfall mit einem niedrigeren Haushaltsdefizit sowie einem niedrigeren Stand an öffentlichen Schulden einher. Fazit: Der Code of Good Practices on Fiscal Transparency ist ein wirksames Instrument." Für Prof. Dr. Horst Tomann, Freie Universität Berlin, erfordert fiskalische Transparenz, "dass die Prinzipien der Klarheit, der Wahrheit und der Vollständigkeit bei der Aufstellung und Verabschiedung des Budgets befolgt werden. Der Code of Good Practices on Fiscal Transparency, den der IWF im Rahmen seiner Beratungspraxis entwickelt hat, enthält im Grunde nichts anderes."Finanzpolitik, Europäische Wirtschafts- und Währungsunion, Konvergenzkriterien, Haushaltsdefizit, Öffentlicher Haushalt, EU-Staaten, Deutschland

    Optical properties of cometary particles collected by the COSIMA mass spectrometer on-board <i>Rosetta</i> during the rendezvous phase around comet 67P/Churyumov–Gerasimenko

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    40 000 collected cometary particles have been identified on the 21 targets exposed by the COSIMA experiment on-board Rosetta to the environment of comet 67P/Churyumov–Gerasimenko from 2014 August to 2016 September. The images of the targets where obtained by the COSIMA microscope (Cosiscope, 13.95 μm pixel−1) with near grazing incidence, which is optimal for the primary objective (detection of collected particles) but very challenging for photometry. However, more than 300 of the collected particles are larger than 100 μm which makes it possible to derive constraints on the optical properties from the distribution of light levels within the particles. Two types of particles collected by COSIMA (compact particles and cluster particles) have been identified in Langevin et al. The best estimate reflectance factors of compact particles range from 10 per cent to 23 per cent. For cluster particles (>90 per cent of large collected particles), the comparison of the signal profiles with illumination from two opposite directions shows that there is scattering within the particles, with a mean free path in the 20–25 μm range, which requires high porosity. The best estimate reflectance factors of cluster particles range from 3 per cent to 22 per cent. This range of reflectance factors overlaps with that obtained from observations of the cometary nucleus at macroscopic scales by OSIRIS and it is consistent with that measured for interplanetary dust particles collected in the stratosphere of the Earth

    On the unconstrained expansion of a spherical plasma cloud turning collisionless : case of a cloud generated by a nanometer dust grain impact on an uncharged target in space

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    Nano and micro meter sized dust particles travelling through the heliosphere at several hundreds of km/s have been repeatedly detected by interplanetary spacecraft. When such fast moving dust particles hit a solid target in space, an expanding plasma cloud is formed through the vaporisation and ionisation of the dust particles itself and part of the target material at and near the impact point. Immediately after the impact the small and dense cloud is dominated by collisions and the expansion can be described by fluid equations. However, once the cloud has reached micro-m dimensions, the plasma may turn collisionless and a kinetic description is required to describe the subsequent expansion. In this paper we explore the late and possibly collisionless spherically symmetric unconstrained expansion of a single ionized ion-electron plasma using N-body simulations. Given the strong uncertainties concerning the early hydrodynamic expansion, we assume that at the time of the transition to the collisionless regime the cloud density and temperature are spatially uniform. We do also neglect the role of the ambient plasma. This is a reasonable assumption as long as the cloud density is substantially higher than the ambient plasma density. In the case of clouds generated by fast interplanetary dust grains hitting a solid target some 10^7 electrons and ions are liberated and the in vacuum approximation is acceptable up to meter order cloud dimensions. ..

    Predicting the Next Best View for 3D Mesh Refinement

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    3D reconstruction is a core task in many applications such as robot navigation or sites inspections. Finding the best poses to capture part of the scene is one of the most challenging topic that goes under the name of Next Best View. Recently, many volumetric methods have been proposed; they choose the Next Best View by reasoning over a 3D voxelized space and by finding which pose minimizes the uncertainty decoded into the voxels. Such methods are effective, but they do not scale well since the underlaying representation requires a huge amount of memory. In this paper we propose a novel mesh-based approach which focuses on the worst reconstructed region of the environment mesh. We define a photo-consistent index to evaluate the 3D mesh accuracy, and an energy function over the worst regions of the mesh which takes into account the mutual parallax with respect to the previous cameras, the angle of incidence of the viewing ray to the surface and the visibility of the region. We test our approach over a well known dataset and achieve state-of-the-art results.Comment: 13 pages, 5 figures, to be published in IAS-1

    Improved fertilization and implantation rates after non-touch zona pellucida microdrilling of mouse oocytes with a 1.48 μm diode laser beam

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    The safety of microdrilling the zona pellucida of moose oocytes with a 1.48 μm diode laser has been investigated by determining the ability of mouse oocytes to fertilize in vitro and develop in vivo. Mice born after transfer of control and zona pelludda-microdrilled embryos into foster mothers were submitted to anatomical and immunohisto-chemical investigations, and their aptitude to breed was assessed in two subsequent generations. Decolonization of the oocytes with hyaluronidase induced a reduction of the fertilization and implantation rates, which was attributed to a zona hardening phenomenon. After laser zona pellucida microdrilling, these rates were restored to those obtained with embryos derived from untreated oocyte-cumulus complexes. Pups derived from zona pellucida microdrilled embryos were comparable with those obtained from control embryos, confirming the lack of deleterious effects of the laser treatment In conclusion, the 1.48 μm diode laser allows safe microdrilling of the zona pellucida of mouse oocytes after decoronization with hyaluronidase. Based on the health of the F2 generation and the lack of neuroanatom-ical and neurochemical differences, we concluded that this technology may be investigated in the human, particularly when the zona pellucida represents the main impediment for fertilization or embryo hatchin
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