NEAT-FT: the European fiber link collaboration

The development of clocks based on optical transitions during the past three decades culminates in the availability of optical clocks with unprecedented stability and uncertainty . Simultaneously, increasing requirements for accurate time and frequency signals, e.g. for tests of fundamental physics or novel applications in relativistic geodesy, put forward new challenges. Typically, such applications rely on the comparison of two remote clocks. Thus, major challenges are how to synchronize these clocks over long distances or how to get the time or frequency signal of a clock to the location where it is required. It is generally agreed that optical fiber links are an excellent alternative to established satellite based distant clock comparison and synchronization techniques. A European joint research project called Network for European Accurate Time and Frequency Transfer (NEAT-FT) has been initiated in 2011 to lay the foundations for a novel approach to disseminate high-precision timing and ultrastable frequency signals by using existing fiber infrastructure. Since Europe has a large number of modern ultra-precise clocks, special emphasis is put on the development of new techniques for time transfer and phase-coherent comparison of remotely located optical clocks and the feasibility of a European fibre network connecting optical clocks in Europe. This talk highlights recent achievements and discusses some applications and prospects

Ciencia de datos como herramienta de soporte en la gestión pública de calidad del agua

El agua es un recurso vital y como tal requiere una adecuada gestión de su calidad para la subsistencia de la población en todas sus dimensiones. En la provincia de Misiones, existen varias organizaciones que intervienen de alguna manera en la gestión de la calidad del agua, aunque se encuentran limitados respecto de la generación de información adecuada para la gestión, pese a esfuerzos individuales de algunas de estas organizaciones. La gestión de calidad del agua es un proceso que requiere datos. Estos datos son generados a un alto costo, ya que cada estudio implica un traslado al lugar donde se realizan las muestras, gastos en recursos humanos, y gastos en el análisis de las propiedades del agua para determinar su calidad, entre otros. En esta línea de investigación se aborda la aplicación de procesos de ciencia de datos que podrían contribuir en la generación de información dirigida a la gestión de calidad del agua. A través de un análisis descriptivo se determinaron parámetros asociados a la calidad del agua, destacándose la temperatura, turbidez, conductividad, pH, P-ortoFosfatos, solidos disueltos totales, oxígeno disuelto, sólidos suspendidos totales y coliformes fecales. Asimismo, se evidencia la necesidad de ampliar el desarrollo de conjuntos de datos que integren variables relevantes para la gestión de la calidad del agua.Red de Universidades con Carreras en Informátic

Complete positivity of nonlinear evolution: A case study

Simple Hartree-type equations lead to dynamics of a subsystem that is not completely positive in the sense accepted in mathematical literature. In the linear case this would imply that negative probabilities have to appear for some system that contains the subsystem in question. In the nonlinear case this does not happen because the mathematical definition is physically unfitting as shown on a concrete example.Comment: extended version, 3 appendices added (on mixed states, projection postulate, nonlocality), to be published in Phys. Rev.

Quantum feedback with weak measurements

The problem of feedback control of quantum systems by means of weak measurements is investigated in detail. When weak measurements are made on a set of identical quantum systems, the single-system density matrix can be determined to a high degree of accuracy while affecting each system only slightly. If this information is fed back into the systems by coherent operations, the single-system density matrix can be made to undergo an arbitrary nonlinear dynamics, including for example a dynamics governed by a nonlinear Schr\"odinger equation. We investigate the implications of such nonlinear quantum dynamics for various problems in quantum control and quantum information theory, including quantum computation. The nonlinear dynamics induced by weak quantum feedback could be used to create a novel form of quantum chaos in which the time evolution of the single-system wave function depends sensitively on initial conditions.Comment: 11 pages, TeX, replaced to incorporate suggestions of Asher Pere

Actualidad de la capacitación en Inteligencia de Negocios brindada por organizaciones latinoamericanas

En la actualidad no se ha identificado un programa de capacitación que defina con claridad las estrategias didácticas y pedagógicas adecuadas para la formación de usuarios finales de soluciones de Inteligencia de Negocios (BI) en al ámbito de organizaciones en BI en Latinoamérica, e identifica un conjunto de características de las alternativas de capacitación ofrecidas, con el objetivo de permitir la generación de planes de capacitación adecuados para la realización de las organizaciones regionales.Currently, there is no training program that cleary defines the appropiate teaching strategies for teaching end users of BI solutions in the province of Misiones (Argentina). This paper presents a survey about BI training offer at Latinoamérica, and identifies a set of characteristics of the alternatives that offered training, which allow to generate adequate training plans for the reality of regional organizations.Facultad de Informátic

Adherence to Sleep Apnea Therapy and Use of Lipid-Lowering Drugs: A Study of the Healthy-User Effect

Evidence that continuous positive airway pressure (CPAP) reduces cardiovascular morbidity comes largely from observational studies. This association may be confounded if CPAP adherents are healthier in ways not measured by investigators. We assessed whether patients adhering to lipid-lowering medications were more adherent to CPAP

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13