513 research outputs found

    Simulation of gemini-agena docking

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    Attitude and translation control using visual docking simulator for Gemini/Agena projec

    Analytical Investigation of the Reentry Behavior of the ''flying Wind Tunnel'' Test Vehicle, with Some Effects of Threshold and Torque Level of a Roll-rate Control System

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    Analytical investigation of reentry behavior of flying wind tunnel test vehicle with some effects of threshold and torque level of roll-rate control syste

    Bridging the Accountability Gap: Rights for New Entities in the Information Society?

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    Technological developments in the information society bring new challenges, both to the applicability and to the enforceability of the law. One major challenge is posed by new entities such as pseudonyms, avatars, and software agents that operate at an increasing distance from the physical persons "behind" them (the "principal"). In case of accidents or misbehavior, current laws require that the physical or legal principal behind the entity be found so that she can be held to account. This may be problematic if the linkability of the principal and the operating entity is questionable. In light of the ongoing developments in electronic agents, there is sufficient reason to conduct a review of the literature in order to more closely examine arguments for and against legal personhood for some nonhuman acting entities. This article also includes a discussion of alternative approaches to solving the "accountability gap.

    Fractal-like structures in colloid science

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    The present work aims at reviewing our current understanding of fractal structures in the frame of colloid aggregation as well as the possibility they offer to produce novel structured materials. In particular, the existing techniques to measure and compute the fractal dimension df are critically discussed based on the cases of organic/inorganic particles and proteins. Then the aggregation conditions affecting df are thoroughly analyzed, pointing out the most recent literature findings and the limitations of our current understanding. Finally, the importance of the fractal dimension in applications is discussed along with possible directions for the production of new structured materials

    Carpal tunnel syndrome caused by a giant lipoma of the hand: A case report

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    Introduction and importance: Lipomas are common benign tumours which occur in up to 2% of the population. They are classified as giant when larger than 5 cm. Although they are usually asymptomatic, giant lipomas of the hand may cause compression of the underlying tissues. Case presentation: A 62-year-old Caucasian male presented to the Plastic and Reconstructive Surgery outpatient clinic with numbness and pain in his left hand. The numbness in his fingers pointed to compression of the median nerve, as well as the ulnar nerve. He presented with a rapidly progressive swelling in his left palm. An MRI scan of the hand was made, which showed a lipoma of approximately 8,5 cm in diameter. The swelling was surgically removed and sent for histopathological analysis, which confirmed the diagnosis of benign giant lipoma of the hand. Two weeks postoperatively, pain and numbness significantly decreased. Clinical discussion: Neural injury in carpal tunnel syndrome is related to the duration and degree of compression. A giant lipoma is considered malignant until proven otherwise since variants with high potential for metastasizing exist. Distinguishing between a benign tumour and a malignant lipoma is essential, since a more radical treatment plan might be required. Conclusion: Giant lipomas of the hand are a rare cause of carpal tunnel syndrome and a malignant variant should always be suspected. A preoperative MRI scan should be performed. Rapid en bloc excision is necessary in case of compression of the underlying tissues

    The deep-sea hub of the ANTARES neutrino telescope

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    The ANTARES neutrino telescope, currently under construction at 2500 m depth off the French Mediterranean coast, will contain 12 detection lines, powered and read out through a deep-sea junction box (JB) hub. Electrical energy from the shore station is distributed through a transformer with multiple secondary windings and a plugboard with 16 deep sea-mateable electro-optic connectors. Connections are made to the JB outputs using manned or remotely operated submersible vehicles. The triply redundant power management and slow control system is based on two identical AC-powered systems, communicating with the shore through 160 Mb/s fibre G-links and a third battery-powered system using a slower link. We describe the power and slow control systems of the underwater hub

    Pkd1 Regulates Lymphatic Vascular Morphogenesis during Development.

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    Lymphatic vessels arise during development through sprouting of precursor cells from veins, which is regulated by known signaling and transcriptional mechanisms. The ongoing elaboration of vessels to form a network is less well understood. This involves cell polarization, coordinated migration, adhesion, mixing, regression, and shape rearrangements. We identified a zebrafish mutant, lymphatic and cardiac defects 1 (lyc1), with reduced lymphatic vessel development. A mutation in polycystic kidney disease 1a was responsible for the phenotype. PKD1 is the most frequently mutated gene in autosomal dominant polycystic kidney disease (ADPKD). Initial lymphatic precursor sprouting is normal in lyc1 mutants, but ongoing migration fails. Loss of Pkd1 in mice has no effect on precursor sprouting but leads to failed morphogenesis of the subcutaneous lymphatic network. Individual lymphatic endothelial cells display defective polarity, elongation, and adherens junctions. This work identifies a highly selective and unexpected role for Pkd1 in lymphatic vessel morphogenesis during development

    First light of the VLT planet finder SPHERE. I. Detection and characterization of the sub-stellar companion GJ 758 B

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    GJ758 B is a brown dwarf companion to a nearby (15.76 pc) solar-type, metal-rich (M/H = +0.2 dex) main-sequence star (G9V) that was discovered with Subaru/HiCIAO in 2009. From previous studies, it has drawn attention as being the coldest (~600K) companion ever directly imaged around a neighboring star. We present new high-contrast data obtained during the commissioning of the SPHERE instrument at the VLT. The data was obtained in Y-, J-, H-, and Ks-bands with the dual-band imaging (DBI) mode of IRDIS, providing a broad coverage of the full near-infrared (near-IR) range at higher contrast and better spectral sampling than previously reported. In this new set of high-quality data, we report the re-detection of the companion, as well as the first detection of a new candidate closer-in to the star. We use the new 8 photometric points for an extended comparison of GJ758 B with empirical objects and 4 families of atmospheric models. From comparison to empirical object, we estimate a T8 spectral type, but none of the comparison object can accurately represent the observed near-IR fluxes of GJ758 B. From comparison to atmospheric models, we attribute a Teff = 600K ±\pm 100K, but we find that no atmospheric model can adequately fit all the fluxes of GJ758 B. The photometry of the new candidate companion is broadly consistent with L-type objects, but a second epoch with improved photometry is necessary to clarify its status. The new astrometry of GJ758 B shows a significant proper motion since the last epoch. We use this result to improve the determination of the orbital characteristics using two fitting approaches, Least-Square Monte Carlo and Markov Chain Monte Carlo. Finally, we analyze the sensitivity of our data to additional closer-in companions and reject the possibility of other massive brown dwarf companions down to 4-5 AU. [abridged]Comment: 20 pages, 15 figures. Accepted for publication in A&
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