445 research outputs found

    Photon condensation in circuit quantum electrodynamics by engineered dissipation

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    We study photon condensation phenomena in a driven and dissipative array of superconducting microwave resonators. Specifically, we show that by using an appropriately designed coupling of microwave photons to superconducting qubits, an effective dissipative mechanism can be engineered, which scatters photons towards low-momentum states while conserving their number. This mimics a tunable coupling of bosons to a low-temperature bath, and leads to the formation of a stationary photon condensate in the presence of losses and under continuous-driving conditions. In this paper, we propose a realistic experimental setup to observe this effect in two or multiple coupled cavities, and study the characteristics of such an out-of-equilibrium condensate, which arise from the competition between pumping and dissipation processes

    Atom-field dressed states in slow-light waveguide QED

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    We discuss the properties of atom-photon bound states in waveguide QED systems consisting of single or multiple atoms coupled strongly to a finite-bandwidth photonic channel. Such bound states are formed by an atom and a localized photonic excitation and represent the continuum analog of the familiar dressed states in single-mode cavity QED. Here we present a detailed analysis of the linear and nonlinear spectral features associated with single- and multiphoton dressed states and show how the formation of bound states affects the waveguide-mediated dipole-dipole interactions between separated atoms. Our results provide both a qualitative and quantitative description of the essential strong-coupling processes in waveguide QED systems, which are currently being developed in the optical and microwave regimes

    Erratum: Atom-field dressed states in slow-light waveguide QED [Phys. Rev. A 93, 033833 (2016)]

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    We discuss the properties of atom-photon bound states in waveguide QED systems consisting of single or multiple atoms coupled strongly to a finite-bandwidth photonic channel. Such bound states are formed by an atom and a localized photonic excitation and represent the continuum analog of the familiar dressed states in single-mode cavity QED. Here we present a detailed analysis of the linear and nonlinear spectral features associated with single- and multiphoton dressed states and show how the formation of bound states affects the waveguide-mediated dipole-dipole interactions between separated atoms. Our results provide both a qualitative and quantitative description of the essential strong-coupling processes in waveguide QED systems, which are currently being developed in the optical and microwave regimes

    Modeling meiotic chromosomes indicates a size dependent contribution of telomere clustering and chromosome rigidity to homologue juxtaposition

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    Meiosis is the cell division that halves the genetic component of diploid cells to form gametes or spores. To achieve this, meiotic cells undergo a radical spatial reorganisation of chromosomes. This reorganisation is a prerequisite for the pairing of parental homologous chromosomes and the reductional division, which halves the number of chromosomes in daughter cells. Of particular note is the change from a centromere clustered layout (Rabl configuration) to a telomere clustered conformation (bouquet stage). The contribution of the bouquet structure to homologous chromosome pairing is uncertain. We have developed a new in silico model to represent the chromosomes of Saccharomyces cerevisiae in space, based on a worm-like chain model constrained by attachment to the nuclear envelope and clustering forces. We have asked how these constraints could influence chromosome layout, with particular regard to the juxtaposition of homologous chromosomes and potential nonallelic, ectopic, interactions. The data support the view that the bouquet may be sufficient to bring short chromosomes together, but the contribution to long chromosomes is less. We also find that persistence length is critical to how much influence the bouquet structure could have, both on pairing of homologues and avoiding contacts with heterologues. This work represents an important development in computer modeling of chromosomes, and suggests new explanations for why elucidating the functional significance of the bouquet by genetics has been so difficult

    Reservoir engineering and dynamical phase transitions in optomechanical arrays

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    We study the driven-dissipative dynamics of photons interacting with an array of micromechanical membranes in an optical cavity. Periodic membrane driving and phonon creation result in an effective photon-number conserving non-unitary dynamics, which features a steady state with long-range photonic coherence. If the leakage of photons out of the cavity is counteracted by incoherent driving of the photonic modes, we show that the system undergoes a dynamical phase transition to the state with long-range coherence. A minimal system, composed of two micromechanical membranes in a cavity, is studied in detail, and it is shown to be a realistic setup where the key processes of the driven-dissipative dynamics can be seen.PhysicsVersion of Recor

    CCL5/RANTES, sVCAM-1, and sICAM-1 in chronic spontaneous urticaria

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    Background: Chronic urticaria (CU) is a common disease characterized by recurrent itchy wheals and/or angioedema for more than 6 weeks. We aimed to investigate the potential involvement of chemotactic mediators and soluble adhesion molecules as markers of endothelial dysfunction in the pathogenesis of chronic spontaneous urticaria (CSU). The potential relevance of these soluble mediators in the evaluation of disease activity was also investigated. Methods: We measured the levels of CCL5/RANTES, CXCL8/IL-8, sVCAM-1, and sICAM-1 in the sera of 87 patients with CSU and 61 normal healthy subjects (NHS) using ELISA assays. According to the results of autologous serum skin tests (ASST), CSU patients were classified into ASST-positive and ASST-negative subgroups. Furthermore, we investigated in 4 patients whether H1-antihistamine therapy decreases sVCAM-1 and sICAM-1 levels. Results: We detected a significantly higher concentration of CCL5/RANTES (p < 0.0001) but not of CXCL8/IL-8 in CSU patients compared to NHS. The serum levels of sICAM-1 and sVCAM-1 were significantly increased in CSU patients compared to NHS (p = 0.0121 and p = 0.0043, respectively). No difference in chemokine or soluble adhesion molecule levels was detected between the ASST-positive and ASST-negative subgroups. A positive correlation was found between sICAM-1 and sVCAM-1 (p = 0.0022) but not between these and CCL5/RANTES. After H1-antihistamine therapy, sVCAM-1 and sICAM-1 levels did not decrease in the 4 CSU patients tested. Conclusions: Our study suggests that CCL5/RANTES, sICAM-1, and sVCAM-1 play a potential role in the pathogenesis of CSU but they do not parallel disease activity and are not predictive of the response to H1- antihistamine therapy

    sj-docx-1-pss-10.1177_09567976231194590 – Supplemental material for Online Interaction Turns the Congeniality Bias Into an Uncongeniality Bias

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    Supplemental material, sj-docx-1-pss-10.1177_09567976231194590 for Online Interaction Turns the Congeniality Bias Into an Uncongeniality Bias by Jürgen Buder, Anja Zimmermann, Brett Buttliere, Lisa Rabl, Moritz Vogel and Markus Huff in Psychological Science</p

    "Recreational" drug abuse associated with failure to mount a proper antibody response after a generalised orthopoxvirus infection

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    Infections with orthopoxviruses usually Lead to cross-protection among all species of the family. This has been a prerequisite for successful eradication of smallpox. Here we report the rare case of a 17-year-old male, who survived a generalised cowpox virus infection of unusual severity but surprisingly did not show a proper seroconversion. Only a very weak antibody production was observed in early and late serum samples, which initially appeared to be cowpox virus specific in immunofluorescence. No neutralising antibodies were detected and in Western blotting antibody specificity was restricted to the orthopoxvirus H3L protein only. The patient had been hospitalised for alcohol and cannabis intoxication 2 months prior to the orthopoxvirus infection and high levels of cannabinoids have been found repeatedly in the urine and upon one occasion also benzodiazepines. As these substances are known to interfere with antibody production and no immunodeficiencies were detected, drug-induced immunosuppression can be suspected as the most Likely cause. Therefore a possible link between "soft" drug use and sufficient immunosuppression to warrant alterations in vaccine policies using Live virus vaccines Like smallpox vaccine should be further studied

    Integrating Massive Data Streams

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    Data Integration has been a long-standing and challenging problem for enterprises and researchers. Data residing in multiple heterogeneous sources must be integrated and prepared such that the valuable information that it carries, can be extracted and analysed. However, the volume and the velocity of the produced data in addition to the modern business needs for real-time results have pushed data analytics, and therefore data integration, towards data streams. While data integration is a hard problem in and of itself, integrating data streams becomes even more challenging. Streams are characterized by their high velocity, infinite nature and predisposition to concept drift.The goal of this doctoral work is to design and provide scalable methods to support data integration tasks on massive data streams, i.e., support streaming data integration. The aim of this work is threefold. First, we aim at developing and proposing streaming methods to compute temporal stream data-profiles and summaries that can describe the dynamic state of a stream in the course of time. Second, we aim at developing methods and metrics of stream similarity. Those methods and metrics can serve as means to detect similar or complementary streams in a streaming data lake. Finally, we aim at optimizing distributed streaming similarity joins - a very important operation that precedes entity linking and resolution. This paper discusses exciting challenges and open problems in the field, and a research plan on tackling them.Web Information SystemsSoftware Technolog
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