2,659 research outputs found

    Diffusion technique stabilizes resistor values

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    Reduction of the contact resistance stabilizes the values, over a broad temperature range, of resistors used in linear integrated circuits. This reduction is accomplished by p-plus diffusion under the alloyed aluminum contacts

    Investigation of HNCO isomers formation in ice mantles by UV and thermal processing: an experimental approach

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    Current gas phase models do not account for the abundances of HNCO isomers detected in various environments, suggesting a formation in icy grain mantles. We attempted to study a formation channel of HNCO and its possible isomers by vacuum-UV photoprocessing of interstellar ice analogues containing H2_2O, NH3_3, CO, HCN, CH3_3OH, CH4_4, and N2_2 followed by warm-up, under astrophysically relevant conditions. Only the H2_2O:NH3_3:CO and H2_2O:HCN ice mixtures led to the production of HNCO species. The possible isomerization of HNCO to its higher energy tautomers following irradiation or due to ice warm-up has been scrutinized. The photochemistry and thermal chemistry of H2_2O:NH3_3:CO and H2_2O:HCN ices was simulated using the Interstellar Astrochemistry Chamber (ISAC), a state-of-the-art ultra-high-vacuum setup. The ice was monitored in situ by Fourier transform mid-infrared spectroscopy in transmittance. A quadrupole mass spectrometer (QMS) detected the desorption of the molecules in the gas phase. UV-photoprocessing of H2_2O:NH3_3:CO/H2_2O:HCN ices lead to the formation of OCN^- as main product in the solid state and a minor amount of HNCO. The second isomer HOCN has been tentatively identified. Despite its low efficiency, the formation of HNCO and the HOCN isomers by UV-photoprocessing of realistic simulated ice mantles, might explain the observed abundances of these species in PDRs, hot cores, and dark clouds

    Simulating noisy quantum protocols with quantum trajectories

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    The theory of quantum trajectories is applied to simulate the effects of quantum noise sources induced by the environment on quantum information protocols. We study two models that generalize single qubit noise channels like amplitude damping and phase flip to the many-qubit situation. We calculate the fidelity of quantum information transmission through a chaotic channel using the teleportation scheme with different environments. In this example, we analyze the role played by the kind of collective noise suffered by the quantum processor during its operation. We also investigate the stability of a quantum algorithm simulating the quantum dynamics of a paradigmatic model of chaos, the baker's map. Our results demonstrate that, using the quantum trajectories approach, we are able to simulate quantum protocols in the presence of noise and with large system sizes of more than 20 qubits.Comment: 11 pages, 7 fig

    CRISPR/Cas9 mutagenesis invalidates a putative cancer dependency targeted in on-going clinical trials

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    The Maternal Embryonic Leucine Zipper Kinase (MELK) has been reported to be a genetic dependency in several cancer types. MELK RNAi and small-molecule inhibitors of MELK block the proliferation of various cancer cell lines, and MELK knockdown has been described as particularly effective against the highly-aggressive basal/triple-negative subtype of breast cancer. Based on these preclinical results, the MELK inhibitor OTS167 is currently being tested as a novel chemotherapy agent in several clinical trials. Here, we report that mutagenizing MELK with CRISPR/Cas9 has no effect on the fitness of basal breast cancer cell lines or cell lines from six other cancer types. Cells that harbor null mutations in MELK exhibit wild-type doubling times, cytokinesis, and anchorage-independent growth. Furthermore, MELK-knockout lines remain sensitive to OTS167, suggesting that this drug blocks cell division through an off-target mechanism. In total, our results undermine the rationale for a series of current clinical trials and provide an experimental approach for the use of CRISPR/Cas9 in preclinical target validation that can be broadly applied

    The spectacular evolution of Supernova 1996al over 15 years: a low energy explosion of a stripped massive star in a highly structured environment

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    Spectrophotometry of SN 1996al carried out throughout 15 years is presented. The early photometry suggests that SN 1996al is a Linear type-II supernova, with an absolute peak of Mv ~ -18.2 mag. Early spectra present broad, asymmetric Balmer emissions, with super-imposed narrow lines with P-Cygni profile, and He I features with asymmetric, broad emission components. The analysis of the line profiles shows that the H and He broad components form in the same region of the ejecta. By day +142, the Halpha profile dramatically changes: the narrow P-Cygni profile disappears, and the Halpha is fitted by three emission components, that will be detected over the remaining 15 yrs of the SN monitoring campaign. Instead, the He I emissions become progressively narrower and symmetric. A sudden increase in flux of all He I lines is observed between 300 and 600 days. Models show that the supernova luminosity is sustained by the interaction of low mass (~1.15 Msun) ejecta, expelled in a low kinetic energy (~ 1.6 x 10^50 erg) explosion, with highly asymmetric circumstellar medium. The detection of Halpha emission in pre-explosion archive images suggests that the progenitor was most likely a massive star (~25 Msun ZAMS) that had lost a large fraction of its hydrogen envelope before explosion, and was hence embedded in a H-rich cocoon. The low-mass ejecta and modest kinetic energy of the explosion are explained with massive fallback of material into the compact remnant, a 7-8 Msun black hole.Comment: 27 pages, 23 figures, Accepted for publication in MNRA

    Oneiric stress and safety and security at work: the discovery of a new universal symbol

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    Cox and Griffiths define as psychosocial risks at work “those aspects of the planning, organization and management of work, which, along with their environmental and social contexts, may affect mental and physical health of the employees, directly or indirectly producing stress”. Therefore, a more effective approach to occupational safety and security should include integrated risk management through the identification of any work stress related problem. The purpose of this paper is to analyze the possible correlation of risk at work with the modification of sleep, and inside it, the specific function of dream activity

    A New Precision Process at FCC-hh: the diphoton leptonic Wh channel

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    The increase in luminosity and center of mass energy at the FCC-hh will open up new clean channels where BSM contributions are enhanced at high energy. In this paper we study one such channel, WhνγγWh \to \ell\nu\gamma\gamma. We estimate the sensitivity to the Oφq(3)\mathcal{O}_{\varphi q}^{(3)}, OφW\mathcal{O}_{\varphi {W}}, and OφW~\mathcal{O}_{\varphi \widetilde {W}} SMEFT operators. We find that this channel will be competitive with fully leptonic WZWZ production in setting bounds on Oφq(3)\mathcal{O}_{\varphi q}^{(3)}. We also find that the double differential distribution in the pThp_T^h and the leptonic azimuthal angle can be exploited to enhance the sensitivity to OφW~\mathcal{O}_{\varphi \widetilde {W}}. However, the bounds on OφW\mathcal{O}_{\varphi {W}} and OφW~\mathcal{O}_{\varphi \widetilde {W}} we obtain in our analysis, though complementary and more direct, are not competitive with those coming from other measurements such as EDMs and inclusive Higgs measurements.Comment: 19 + 9 pages, 7 figures, and 9 table

    Point-like topological defects in bilayer quantum Hall systems

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    Following a suggestion given in Phys. Lett. B 571 (2003) 250, we show how a bilayer Quantum Hall system at fillings nu =m/pm+2 can exhibit a point-like topological defect in its edge state structure. Indeed our CFT theory for such a system, the Twisted Model (TM), gives rise in a natural way to such a feature in the twisted sector. Our results are in agreement with recent experimental findings (cond-mat/0503478) which evidence the presence of a topological defect in the bilayer system.Comment: 9 pages, 3 figure

    Il dolore tra natura e cultura

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    Summary Pain and suffering represent unavoidable experiences that have left a deep mark on the history of mankind. In this review, pain is examined from an anthropological point of view, because there is no pain without suffering, and every biophysical event is brought to the consciousness of an individual by an emotional signal. The body is an entity that changes from culture to culture and operates within particular historical and social contexts. Each society incorporates the concept of pain into its particular worldview, assigning it a specific meaning and value. Few human experiences can be read in as many different keys: from neuroscience to linguistic research, perspective selection, and emotional and cognitive functions. Although pain is currently regarded as a destructive force that is per se pathological, it is actually a form of protection. In today's society, pain is experienced as a problem in itself, a disease within a disease, and its physiopathological aspects have been extensively characterized. But pain must also be analyzed within its anthropological, sociological, political, and economic contexts. The phenomenon of pain lies at the crossroads between nature and culture, and analysis from this perspective is essential for explaining the multiplicity of related data. The "anthropology of pain" explains, among other things, the assortment of reactions to identical pain stimuli among individuals and groups: for example, the higher opposition to pain observed among individuals living in poverty, the phenomenon of "combat analgesia", and the wide variety of analgesics used by traditional populations

    The Arabic Diatessaron Project: Digitalizing, Encoding, Lemmatization

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    The Arabic Diatessaron Project (henceforth ADP) is an international research project in Digital Humanities that aims to collect, digitalise and encode all known manuscripts of the Arabic Diatessaron (henceforth AD), a text that has been relatively neglected in scholarly research. ADP's final goal is to provide a number of tools that can enable scholars to effectively query, compare and investigate all known variants of the text that will be encoded as far as possible in compliance with the Text Encoding Initiative (TEI) guidelines. The paper addresses a number of issues involved in the process of digitalising manuscripts included in the two existing editions (Ciasca 1888 and Marmardji 1935), adding variants in unedited manuscripts, encoding and lemmatising the text. Issues involved in the design of the ADP include presentation of variants, choice of the standard text, applicability of TEI guidelines, automatic translation between different encodings, cross-edition concordances and principles of lemmatisation
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