79 research outputs found

    Implementing quantum gates through scattering between a static and a flying qubit

    Get PDF
    We investigate whether a two-qubit quantum gate can be implemented in a scattering process involving a flying and a static qubit. To this end, we focus on a paradigmatic setup made out of a mobile particle and a quantum impurity, whose respective spin degrees of freedom couple to each other during a one-dimensional scattering process. Once a condition for the occurrence of quantum gates is derived in terms of spin-dependent transmission coefficients, we show that this can be actually fulfilled through the insertion of an additional narrow potential barrier. An interesting observation is that under resonance conditions the above enables a gate only for isotropic Heisenberg (exchange) interactions and fails for an XY interaction. We show the existence of parameter regimes for which gates able to establish a maximum amount of entanglement can be implemented. The gates are found to be robust to variations of the optimal parameters.Comment: 7 pages, 3 figure

    Analysing Scattering-Based Music Content Analysis Systems: Where's the Music?

    Get PDF
    Music content analysis (MCA) systems built using scattering transform features are reported quite successful in the GTZAN benchmark music dataset. In this paper, we seek to answer why. We first analyse the feature extraction and classification components of scattering-based MCA systems. This guides us to perform intervention experiments on three factors: train/test partition, classifier and recording spectrum. The partition intervention shows a decrease in the amount of reproduced ground truth by the resulting systems. We then replace the learning algorithm with a binary decision tree, and identify the impact of specific feature dimensions. We finally alter the spectral content related to such dimensions, which reveals that these scattering-based systems exploit acoustic information below 20 Hz to reproduce GTZAN ground truth. The source code to reproduce our experiments is available online

    Failure to decrease HbA1c levels following TB treatment is associated with elevated Th1/Th17 CD4+ responses

    Get PDF
    Introduction: The rising global burden of metabolic disease impacts the control of endemic tuberculosis (TB) in many regions, as persons with diabetes mellitus (DM) are up to three times more likely to develop active TB than those without DM. Active TB can also promote glucose intolerance during both acute infection and over a longer term, potentially driven by aspects of the immune response. Identifying patients likely to have persistent hyperglycemia following TB treatment would enable closer monitoring and care, and an improved understanding of underlying immunometabolic dysregulation. // Methods: We measured the relationship of plasma cytokine levels, T cell phenotypes and functional responses with the change in hemoglobin A1c (HbA1c) before and after treatment of pulmonary TB in a prospective observational cohort in Durban, South Africa. Participants were stratified based on stable/increased HbA1c (n = 16) versus decreased HbA1c (n = 46) levels from treatment initiation to 12 month follow-up. // Results: CD62 P-selectin was up- (1.5-fold) and IL-10 downregulated (0.85-fold) in plasma among individuals whose HbA1c remained stable/increased during TB treatment. This was accompanied by increased pro-inflammatory TB-specific IL-17 production (Th17). In addition, Th1 responses were upregulated in this group, including TNF-α production and CX3CR1 expression, with decreased IL-4 and IL-13 production. Finally, the TNF-α+ IFNγ+ CD8+ T cells were associated with stable/increased HbA1c. These changes were all significantly different in the stable/increased HbA1c relative to the decreased HbA1c group. // Discussion: Overall, these data suggest that patients with stable/increased HbA1c had an increased pro-inflammatory state. Persistent inflammation and elevated T cell activity in individuals with unresolved dysglycemia following TB treatment may indicate failure to fully resolve infection or may promote persistent dysglycemia in these individuals, and further studies are needed to explore potential mechanisms

    Efeitos da quantidade de lã no escroto sobre características reprodutivas de carneiros Corriedale no decorrer do ano.

    Get PDF
    O presente trabalho foi delineado para se avaliar possíveis modificações nas características reprodutivas de carneiros em função da quantidade de lã no escroto e época do ano

    Design and implementation of a global site assessment survey among HIV clinics participating in the International epidemiology Databases to Evaluate AIDS (IeDEA) research consortium

    Get PDF
    Introduction Timely descriptions of HIV service characteristics and their evolution over time across diverse settings are important for monitoring the scale-up of evidence-based program strategies, understanding the implementation landscape, and examining service delivery factors that influence HIV care outcomes. Methods The International epidemiology Databases to Evaluate AIDS (IeDEA) consortium undertakes periodic cross-sectional surveys on service availability and care at participating HIV treatment sites to characterize trends and inform the scientific agenda for HIV care and implementation science communities. IeDEA’s 2020 general site assessment survey was developed through a consultative, 18-month process that engaged diverse researchers in identifying content from previous surveys that should be retained for longitudinal analyses and in developing expanded and new content to address gaps in the literature. An iterative review process was undertaken to standardize the format of new survey questions and align them with best practices in survey design and measurement and lessons learned through prior IeDEA site assessment surveys. Results The survey questionnaire developed through this process included eight content domains covered in prior surveys (patient population, staffing and community linkages, HIV testing and diagnosis, new patient care, treatment monitoring and retention, routine HIV care and screening, pharmacy, record-keeping and patient tracing), along with expanded content related to antiretroviral therapy (differentiated service delivery and roll-out of dolutegravir-based regimens); mental health and substance use disorders; care for pregnant/postpartum women and HIV-exposed infants; tuberculosis preventive therapy; and pediatric/adolescent tuberculosis care; and new content related to Kaposi’s sarcoma diagnostics, the impact of COVID-19 on service delivery, and structural barriers to HIV care. The survey was distributed to 238 HIV treatment sites in late 2020, with a 95% response rate. Conclusion IeDEA’s approach for site survey development has broad relevance for HIV research networks and other priority health conditions

    New Insights into Fluoroquinolone Resistance in Mycobacterium tuberculosis: Functional Genetic Analysis of gyrA and gyrB Mutations

    Get PDF
    Fluoroquinolone antibiotics are among the most potent second-line drugs used for treatment of multidrug-resistant tuberculosis (MDR TB), and resistance to this class of antibiotics is one criterion for defining extensively drug resistant tuberculosis (XDR TB). Fluoroquinolone resistance in Mycobacterium tuberculosis has been associated with modification of the quinolone resistance determining region (QRDR) of gyrA. Recent studies suggest that amino acid substitutions in gyrB may also play a crucial role in resistance, but functional genetic studies of these mutations in M. tuberculosis are lacking. In this study, we examined twenty six mutations in gyrase genes gyrA (seven) and gyrB (nineteen) to determine the clinical relevance and role of these mutations in fluoroquinolone resistance. Transductants or clinical isolates harboring T80A, T80A+A90G, A90G, G247S and A384V gyrA mutations were susceptible to all fluoroquinolones tested. The A74S mutation conferred low-level resistance to moxifloxacin but susceptibility to ciprofloxacin, levofloxacin and ofloxacin, and the A74S+D94G double mutation conferred cross resistance to all the fluoroquinolones tested. Functional genetic analysis and structural modeling of gyrB suggest that M330I, V340L, R485C, D500A, D533A, A543T, A543V and T546M mutations are not sufficient to confer resistance as determined by agar proportion. Only three mutations, N538D, E540V and R485C+T539N, conferred resistance to all four fluoroquinolones in at least one genetic background. The D500H and D500N mutations conferred resistance only to levofloxacin and ofloxacin while N538K and E540D consistently conferred resistance to moxifloxacin only. Transductants and clinical isolates harboring T539N, T539P or N538T+T546M mutations exhibited low-level resistance to moxifloxacin only but not consistently. These findings indicate that certain mutations in gyrB confer fluoroquinolone resistance, but the level and pattern of resistance varies among the different mutations. The results from this study provide support for the inclusion of the QRDR of gyrB in molecular assays used to detect fluoroquinolone resistance in M. tuberculosis

    Rapid determination of anti-tuberculosis drug resistance from whole-genome sequences

    Get PDF
    Mycobacterium tuberculosis drug resistance (DR) challenges effective tuberculosis disease control. Current molecular tests examine limited numbers of mutations, and although whole genome sequencing approaches could fully characterise DR, data complexity has restricted their clinical application. A library (1,325 mutations) predictive of DR for 15 anti-tuberculosis drugs was compiled and validated for 11 of them using genomic-phenotypic data from 792 strains. A rapid online ‘TB-Profiler’ tool was developed to report DR and strain-type profiles directly from raw sequences. Using our DR mutation library, in silico diagnostic accuracy was superior to some commercial diagnostics and alternative databases. The library will facilitate sequence-based drug-susceptibility testing

    Optimal design of measurements on queueing systems

    Get PDF
    We examine the optimal design of measurements on queues with particular reference to the M/M/1 queue. Using the statistical theory of design of experiments, we calculate numerically the Fisher information matrix for an estimator of the arrival rate and the service rate to find optimal times to measure the queue when the number of measurements are limited for both interfering and non-interfering measurements. We prove that in the non-interfering case, the optimal design is equally spaced. For the interfering case, optimal designs are not necessarily equally spaced. We compute optimal designs for a variety of queuing situations and give results obtained under the DD-- and DsD_s-optimality criteria

    Pasados y presente. Estudios para el profesor Ricardo García Cárcel

    Get PDF
    Ricardo García Cárcel (Requena, 1948) estudió Historia en Valencia bajo el magisterio de Joan Reglà, con quien formó parte del primer profesorado de historia moderna en la Universidad Autónoma de Barcelona. En esta universidad, desde hace prácticamente cincuenta años, ha desarrollado una extraordinaria labor docente y de investigación marcada por un sagaz instinto histórico, que le ha convertido en pionero de casi todo lo que ha estudiado: las Germanías, la historia de la Cataluña moderna, la Inquisición, las culturas del Siglo de Oro, la Leyenda Negra, Felipe II, Felipe V, Austrias y Borbones, la guerra de la Independencia, la historia cultural, los mitos de la historia de España... Muy pocos tienen su capacidad para reflexionar, ordenar, analizar, conceptualizar y proponer una visión amplia y llena de matices sobre el pasado y las interpretaciones historiográficas. A su laboriosidad inimitable se añade una dedicación sin límites en el asesoramiento de alumnos e investigadores e impulsando revistas, dosieres, seminarios o publicaciones colectivas. Una mínima correspondencia a su generosidad lo constituye este volumen a manera de ineludible agradecimiento
    corecore