4,981 research outputs found

    Quantifying Genuine Multipartite Correlations and their Pattern Complexity

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    We propose an information-theoretic framework to quantify multipartite correlations in classical and quantum systems, answering questions such as what is the amount of seven-partite correlations in a given state of ten particles? We identify measures of genuine multipartite correlations, i.e., statistical dependencies that cannot be ascribed to bipartite correlations, satisfying a set of desirable properties. Inspired by ideas developed in complexity science, we then introduce the concept of weaving to classify states that display different correlation patterns, but cannot be distinguished by correlation measures. The weaving of a state is defined as the weighted sum of correlations of every order. Weaving measures are good descriptors of the complexity of correlation structures in multipartite systems

    Coherence and quantum correlations measure sensitivity to dephasing channels

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    We introduce measures of quantum coherence as the speed of evolution of a system under decoherence. That is, coherence is the ability to estimate a dephasing channel, quantified by the quantum Fisher information. We extend the analysis to interferometric noise estimation, proving that quantum discord is the minimum sensitivity to local dephasing. A physically motivated set of free operations for discord is proposed. The amount of discord created by strictly incoherent operations is upper bounded by the initial coherence

    Factores multiplicadores del río Tunjuelo

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    (Eng) The most important sources of pollution in urban rivers are the sewage system discharges, disturbing the quality and behavior patterns of water resources. The Tunjuelo River is one of the most polluted and important stream from Bogota city, receiving numerous wastewater discharges. Therefore, its sanitation has become one of the main objectives of the environmental authority. However, in order to take action is necessary to understand the water quality behavior specifically loads patterns. This article shows the results of the load multiplier factors for total suspended solids (TSS) and biochemical oxygen demand (BOD), these factors were calculated to understand the behavior of wastewater discharges and at different points on the river. Finally, each discharge has its own characteristics that affect differently the behavior of the river downstream, resulting in a distortion in the flow pattern in most of the sampled points.(Spa) Las fuentes puntuales de contaminación más importantes en los ríos urbanos son las descargas directas del sistema de alcantarillado, además estas afectan la calidad y el patrón de comportamiento de las fuentes hídricas. El río Tunjuelo es una de las corrientes de agua más importante y contaminada de la ciudad de Bogotá, pues recibe una gran cantidad de vertimientos. Por lo anterior su saneamiento se ha convertido en uno de los principales objetivos de la autoridad ambiental, sin embargo, para poder tomar acciones es necesario entender su comportamiento. En el presente artículo se muestran los resultados de los factores multiplicadores de carga para sólidos suspendidos totales (SST) y demanda bioquímica de oxígeno (DBO), puesto que estos son el instrumento económico para el cálculo de la tasa retributiva en Colombia, los cuales fueron calculados para entender el comportamiento de las descargas de aguas residuales y el de diferentes puntos sobre el río. Finalmente, se puede observar que cada descarga tiene características propias que afectan de diferente manera el comportamiento del río aguas abajo, generando como resultado una distorsión en el patrón de flujo de los factores multiplicadores en la mayoría de puntos muestreados

    A study of random laser modes in disordered photonic crystals

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    We studied lasing modes in a disordered photonic crystal. The scaling of the lasing threshold with the system size depends on the strength of disorder. For sufficiently large size, the minimum of the lasing threshold occurs at some finite value of disorder strength. The highest random cavity quality factor was comparable to that of an intentionally introduced single defect. At the minimum, the lasing threshold showed a super-exponential decrease with the size of the system. We explain it through a migration of the lasing mode frequencies toward the photonic bandgap center, where the localization length takes the minimum value. Random lasers with exponentially low thresholds are predicted.Comment: 4 pages, 4 figure

    The Portuguese observatory on occupational psychosocial factors: contribution for public health

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    To achieve the goal of sustainable employment, considering the profile of the Portuguese working population (PWP), is needed a range of strategies to ensure long, productive, and sustainable careers allied with a better quality of working life, health, and wellbeing, but also with public health policies grounded on scientifically validated and reliable data. This is possible through a comprehensive working system approach that ensures workers will be mentally and physically able to remain at work by the balance between work demands and individual resources allied with public health policies transfer into the workplaces by organizations’ leadership and policy makers. The Portuguese Observatory on Occupational Factors (Popsy@Work) aims at addressing this global challenge by: i) digitally collecting psychosocial data on the PWP; ii) implementing and strengthening of a psychosocial occupational health surveillance digital system; iii) providing reference values for the PWP concerning Psychosocial Health; iv) Transferring to society knowledge and best practices; v) Raising awareness on the importance of psychosocial management in occupational settings based on science. Popsy@work is a digital platform that collects and aggregates psychosocial data analytically and creates a visualization hub adding value to data on the PWP and giving science back to society in a usable way, empowering workers, strengthening organizations and grounding public policies. Pospy@Work considers the development of strategic intelligence on levels and inequalities of psychosocial health and well-being in occupational settings by robust metrics and reference data. Creating opportunities for national policy dialogue on inequalities, including the psychosocial health of the PWP through collaboration with diverse sectors identifying and mapping subgroups of populations whose unmet needs require specific outreach measures

    A Spatiotemporal Map of Co-Receptor Signaling Networks Underlying B Cell Activation

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    The B cell receptor (BCR) signals together with a multi-component co-receptor complex to initiate B cell activation in response to antigen binding. Here, we take advantage of peroxidase-catalyzed proximity labeling combined with quantitative mass spectrometry to track co-receptor signaling dynamics in Raji cells from 10 s to 2 h after BCR stimulation. This approach enables tracking of 2,814 proximity-labeled proteins and 1,394 phosphosites and provides an unbiased and quantitative molecular map of proteins recruited to the vicinity of CD19, the signaling subunit of the co-receptor complex. We detail the recruitment kinetics of signaling effectors to CD19 and identify previously uncharacterized mediators of B cell activation. We show that the glutamate transporter SLC1A1 is responsible for mediating rapid metabolic reprogramming and for maintaining redox homeostasis during B cell activation. This study provides a comprehensive map of BCR signaling and a rich resource for uncovering the complex signaling networks that regulate activation

    An Application of Kerr Blackhole Fly-Wheel Model to Statistical Properties of QSOs/AGNs

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    The aim of this work is to demonstrate the properties of the magnetospheric model around Kerr blackholes (BHs), so-called the fly-wheel (rotation driven) model. The fly-wheel engine of the BH-accretion disk system is applied to the statistics of QSOs/AGNs. In the model, the central BH is assumed to be formed at z∼102z \sim 10^2 and obtains nearly maximum but finite rotation energy (∼\sim extreme Kerr BH) at the formation stage. The inherently obtained rotation energy of the Kerr BH is released through an magnetohydrodynamic process. This model naturally leads finite lifetime of AGN activity. Nitta et al. (1991) clarified individual evolution of Kerr BH fly-wheel engine which is parametrized by BH mass, initial Kerr parameter, magnetic field near the horizon and a dimension-less small parameter. We impose a statistical model for the initial mass function (IMF) of ensemble of BHs by the Press-Schechter formalism. By the help of additional assumptions, we can discuss the evolution of the luminosity function and the spatial number density of QSOs/AGNs.Comment: 12 pages, 7 figures Fig.7 has been replace

    Cosmological Baryon Sound Waves Coupled with the Primeval Radiation

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    The fluid equations for the baryon-electron system in an expanding universe are derived from the Boltzmann equation. The effect of the Compton interaction is taken into account properly in order to evaluate the photon-electron collisional term. As an application, the acoustic motions of the baryon-electron system after recombination are investigated. The effective adiabatic index γ\gamma is computed for sound waves of various wavelengths, assuming the perturbation amplitude is small. The oscillations are found to be dumped when γ\gamma changes from between 1 (for an isothermal process) to 5/3 (for an adiabatic process).Comment: 20 pages, Revtex, Accepted for publication in Phys. Rev.
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