7,729 research outputs found

    An Efficient Algorithm for Optimizing Adaptive Quantum Metrology Processes

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    Quantum-enhanced metrology infers an unknown quantity with accuracy beyond the standard quantum limit (SQL). Feedback-based metrological techniques are promising for beating the SQL but devising the feedback procedures is difficult and inefficient. Here we introduce an efficient self-learning swarm-intelligence algorithm for devising feedback-based quantum metrological procedures. Our algorithm can be trained with simulated or real-world trials and accommodates experimental imperfections, losses, and decoherence

    Guest charges in an electrolyte: renormalized charge, long- and short-distance behavior of the electric potential and density profile

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    We complement a recent exact study by L. Samaj on the properties of a guest charge QQ immersed in a two-dimensional electrolyte with charges +1/1+1/-1. In particular, we are interested in the behavior of the density profiles and electric potential created by the charge and the electrolyte, and in the determination of the renormalized charge which is obtained from the long-distance asymptotics of the electric potential. In Samaj's previous work, exact results for arbitrary coulombic coupling β\beta were obtained for a system where all the charges are points, provided βQ<2\beta Q<2 and β<2\beta < 2. Here, we first focus on the mean field situation which we believe describes correctly the limit β0\beta\to 0 but βQ\beta Q large. In this limit we can study the case when the guest charge is a hard disk and its charge is above the collapse value βQ>2\beta Q>2. We compare our results for the renormalized charge with the exact predictions and we test on a solid ground some conjectures of the previous study. Our study shows that the exact formulas obtained by Samaj for the renormalized charge are not valid for βQ>2\beta Q>2, contrary to a hypothesis put forward by Samaj. We also determine the short-distance asymptotics of the density profiles of the coions and counterions near the guest charge, for arbitrary coulombic coupling. We show that the coion density profile exhibit a change of behavior if the guest charge becomes large enough (βQ2β\beta Q\geq 2-\beta). This is interpreted as a first step of the counterion condensation (for large coulombic coupling), the second step taking place at the usual Manning--Oosawa threshold βQ=2\beta Q=2

    Fungal Rhinosinusitis: A Retrospective Microbiologic and Pathologic Review of 400 Patients at a Single University Medical Center

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    Fungal Rhinosinusitis (FRS) is a well known entity, but only in more recent times have the types of FRS been more fully defined. In this study, we evaluate the diagnosis of FRS in a single medical center. Cases were divided into 2 main categories, non-invasive and invasive. Non-invasive FRS included fungus ball (FB) and allergic fungal rhinosinusitis (AFRS). Invasive FRS included acute invasive fungal rhinosinusitis (AIFRS), chronic invasive fungal rhinosinusitis (CIFRS), and chronic invasive granulomatous fungal rhinosinusitis (CGFRS). Fungal culture data, if available was reviewed. 400 patients with FRS were identified. 87.25% were non-invasive (45% AFRS, 40% FB, and 2% combined AFRS and FB and 12.5% were invasive 11% AIFRS 1.2% CIFRS 0.5% CGFRS. One patient (0.25%) had combined FB/CGFRS. Aspergillus sp. or dematiaceous species were the most common fungi isolated in AFS while Aspergillus sp. was most common in FB and AIFRS. In our experience, most FRS is non-invasive. In our patient population, invasive FRS is rare with AIFRS representing >90% of cases. Culture data supports that a variety of fungal agents are responsible for FRS, but Aspergillus sp. appears to be one of the most common organisms in patients with FRS

    Transferrable protection by gut microbes against STING-associated lung disease

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    STING modulates immunity by responding to bacterial and endogenous cyclic dinucleotides (CDNs). Humans and mice with STING gain-of-function mutations develop a syndrome known as STING-associated vasculopathy with onset in infancy (SAVI), which is characterized by inflammatory or fibrosing lung disease. We hypothesized that hyperresponsiveness of gain-of-function STING to bacterial CDNs might explain autoinflammatory lung disease in SAVI mice. We report that depletion of gut microbes with oral antibiotics (vancomycin, neomycin, and ampicillin [VNA]) nearly eliminates lung disease in SAVI mice, implying that gut microbes might promote STING-associated autoinflammation. However, we show that germ-free SAVI mice still develop severe autoinflammatory disease and that transferring gut microbiota from antibiotics-treated mice to germ-free animals eliminates lung inflammation. Depletion of anaerobes with metronidazole abolishes the protective effect of the VNA antibiotics cocktail, and recolonization with the metronidazole-sensitive anaerobe Bacteroides thetaiotaomicron prevents disease, confirming a protective role of a metronidazole-sensitive microbe in a model of SAVI

    Quantum spin systems at positive temperature

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    We develop a novel approach to phase transitions in quantum spin models based on a relation to their classical counterparts. Explicitly, we show that whenever chessboard estimates can be used to prove a phase transition in the classical model, the corresponding quantum model will have a similar phase transition, provided the inverse temperature β\beta and the magnitude of the quantum spins \CalS satisfy \beta\ll\sqrt\CalS. From the quantum system we require that it is reflection positive and that it has a meaningful classical limit; the core technical estimate may be described as an extension of the Berezin-Lieb inequalities down to the level of matrix elements. The general theory is applied to prove phase transitions in various quantum spin systems with \CalS\gg1. The most notable examples are the quantum orbital-compass model on Z2\Z^2 and the quantum 120-degree model on Z3\Z^3 which are shown to exhibit symmetry breaking at low-temperatures despite the infinite degeneracy of their (classical) ground state.Comment: 47 pages, version to appear in CMP (style files included

    Associations between schizophrenia genetic risk, anxiety disorders and manic/hypomanic episode in a longitudinal population cohort study.

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    BACKGROUND: Studies involving clinically recruited samples show that genetic liability to schizophrenia overlaps with that for several psychiatric disorders including bipolar disorder, major depression and, in a population study, anxiety disorder and negative symptoms in adolescence.AimsWe examined whether, at a population level, association between schizophrenia liability and anxiety disorders continues into adulthood, for specific anxiety disorders and as a group. We explored in an epidemiologically based cohort the nature of adult psychopathology sharing liability to schizophrenia. METHOD: Schizophrenia polygenic risk scores (PRSs) were calculated for 590 European-descent individuals from the Christchurch Health and Development Study. Logistic regression was used to examine associations between schizophrenia PRS and four anxiety disorders (social phobia, specific phobia, panic disorder and generalised anxiety disorder), schizophrenia/schizophreniform disorder, manic/hypomanic episode, alcohol dependence, major depression, and - using linear regression - total number of anxiety disorders. A novel population-level association with hypomania was tested in a UK birth cohort (Avon Longitudinal Study of Parents and Children). RESULTS: Schizophrenia PRS was associated with total number of anxiety disorders and with generalised anxiety disorder and panic disorder. We show a novel population-level association between schizophrenia PRS and manic/hypomanic episode. CONCLUSIONS: The relationship between schizophrenia liability and anxiety disorders is not restricted to psychopathology in adolescence but is present in adulthood and specifically linked to generalised anxiety disorder and panic disorder. We suggest that the association between schizophrenia liability and hypomanic/manic episodes found in clinical samples may not be due to bias.Declarations of interestNone

    Space-based research in fundamental physics and quantum technologies

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    Space-based experiments today can uniquely address important questions related to the fundamental laws of Nature. In particular, high-accuracy physics experiments in space can test relativistic gravity and probe the physics beyond the Standard Model; they can perform direct detection of gravitational waves and are naturally suited for precision investigations in cosmology and astroparticle physics. In addition, atomic physics has recently shown substantial progress in the development of optical clocks and atom interferometers. If placed in space, these instruments could turn into powerful high-resolution quantum sensors greatly benefiting fundamental physics. We discuss the current status of space-based research in fundamental physics, its discovery potential, and its importance for modern science. We offer a set of recommendations to be considered by the upcoming National Academy of Sciences' Decadal Survey in Astronomy and Astrophysics. In our opinion, the Decadal Survey should include space-based research in fundamental physics as one of its focus areas. We recommend establishing an Astronomy and Astrophysics Advisory Committee's interagency ``Fundamental Physics Task Force'' to assess the status of both ground- and space-based efforts in the field, to identify the most important objectives, and to suggest the best ways to organize the work of several federal agencies involved. We also recommend establishing a new NASA-led interagency program in fundamental physics that will consolidate new technologies, prepare key instruments for future space missions, and build a strong scientific and engineering community. Our goal is to expand NASA's science objectives in space by including ``laboratory research in fundamental physics'' as an element in agency's ongoing space research efforts.Comment: a white paper, revtex, 27 pages, updated bibliograph
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