1,227 research outputs found

    Large Deviations Behavior of the Logarithmic Error Probability of Random Codes

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    This work studies the deviations of the error exponent of the constant composition code ensemble around its expectation, known as the error exponent of the typical random code (TRC). In particular, it is shown that the probability of randomly drawing a codebook whose error exponent is smaller than the TRC exponent is exponentially small; upper and lower bounds for this exponent are given, which coincide in some cases. In addition, the probability of randomly drawing a codebook whose error exponent is larger than the TRC exponent is shown to be double–exponentially small; upper and lower bounds to the double–exponential exponent are given. The results suggest that codebooks whose error exponent is larger than the error exponent of the TRC are extremely rare. The key ingredient in the proofs is a new large deviations result of type class enumerators with dependent variables

    Agronomic and environmental implications of substituting pig slurry for synthetic nitrogen in mediterranean wheat systems

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    Using slurries as fertilizers is a promising strategy for the reuse of nutrients and striving towards a circular economy. This study aims to assess the agronomic productivity and the environmental effects on Mediterranean sprinkler-irrigated wheat during three consecutive years of (1) the use of pig slurry (PS) as a substitute for a synthetic fertilizer (urea, U) and (2) the addition of a urease inhibitor (monocarbamide dihydrogen sulfate, MCDHS) to pig slurry (PSI). A nitrogen (N) target rate of 120 kg NH4+-N ha-1 as U, PS, or PSI (main factor) was applied at tillering, and it was supplemented with N application at stem elongation (secondary factor). Grain yield, nitrogen use efficiency indexes, and nitrous oxide emissions were not significantly affected by the N source, U, or PS; in contrast to grain protein that was affected by the N source (lower protein content in PS). The higher unaccounted N from soil balance in PS compared to U fertilization could be associated with higher ammonia volatilization, although additional studies should confirm this hypothesis. Our study suggests that, under the considered cropping conditions, PS does not affect productivity or N2O losses compared to U. The addition of MCDHS to pig slurry did not display agronomic or environmental benefits under the evaluated agro-environmental conditions

    Submillimeter polarisation and magnetic field properties in the envelopes of proto-planetary nebulae CRL 618 and OH 231.8+4.2

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    We have carried out continuum and line polarisation observations of two Proto-planetary nebulae (PPNe), CRL 618 and OH 231.8+4.2, using the Submillimeter Array (SMA) in its compact configuration. The frequency range of observations, 330-345 GHz, includes the CO(J=3-2) line emission. CRL 618 and OH 231.8+4.2 show quadrupolar and bipolar optical lobes, respectively, surrounded by a dusty envelope reminiscent of their AGB phase. We report a detection of dust continuum polarised emission in both PPNe above 4 sigma but no molecular line polarisation detection above a 3 sigma limit. OH 231.8+4.2 is slightly more polarised on average than CRL 618 with a mean fractional polarisation of 4.3 and 0.3 per cent, respectively. This agrees with the previous finding that silicate dust shows higher polarisation than carbonaceous dust. In both objects, an anti-correlation between the fractional polarisation and the intensity is observed. Neither PPNe show a well defined toroidal equatorial field, rather the field is generally well aligned and organised along the polar direction. This is clearly seen in CRL 618 while in the case of OH 231.8+4.2, the geometry indicates an X-shaped structure coinciding overall with a dipole/polar configuration. However in the later case, the presence of a fragmented and weak toroidal field should not be discarded. Finally, in both PPNe, we observed that the well organised magnetic field is parallel with the major axis of the 12CO outflow. This alignment could indicate the presence of a magnetic outflow launching mechanism. Based on our new high resolution data we propose two scenarios to explain the evolution of the magnetic field in evolved stars.Comment: 11 pages, 8 figures and 1 table. Accepted for publication in the Monthly Notices of the Royal Astronomical Societ

    Genotypic and phenotypic characterization of a Salmonella Typhimurium strain resistant to pulsed electric fields

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    Pulsed Electric Fields (PEF) technology is regarded as one of the most interesting alternatives to current food preservation methods, due to its capability to inactivate vegetative microorganisms while leaving the product's organoleptic and nutritional properties mostly unchanged. However, many aspects regarding the mechanisms of bacterial inactivation by PEF are still not fully understood. The aim of this study was to obtain further insight into the mechanisms responsible for the increased resistance to PEF of a Salmonella Typhimurium SL1344 variant (SL1344-RS, Sagarzazu et al., 2013), and to quantify the impact that the acquisition of PEF resistance has on other aspects of S. enterica physiology, such as growth fitness, biofilm formation ability, virulence and antibiotic resistance. WGS, RNAseq and qRT-PCR assays indicated that the increased PEF resistance of the SL1344-RS variant is due to a higher RpoS activity caused by a mutation in the hnr gene. This increased RpoS activity also results in higher resistance to multiple stresses (acidic, osmotic, oxidative, ethanol and UV-C, but not to heat and HHP), decreased growth rate in M9-Gluconate (but not in TSB-YE or LB-DPY), increased ability to adhere to Caco-2 cells (but no significant change in invasiveness) and enhanced antibiotic resistance (to six out of eight agents). This study significantly contributes to the understanding of the mechanisms of the development of stress resistance in Salmonellae and underscores the crucial role played by RpoS in this process. Further studies are needed to determine whether this PEF-resistant variant would represent a higher, equal or lower associated hazard than the parental strain

    New Integrable Sectors in Skyrme and 4-dimensional CP^n Model

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    The application of a weak integrability concept to the Skyrme and CPnCP^n models in 4 dimensions is investigated. A new integrable subsystem of the Skyrme model, allowing also for non-holomorphic solutions, is derived. This procedure can be applied to the massive Skyrme model, as well. Moreover, an example of a family of chiral Lagrangians providing exact, finite energy Skyrme-like solitons with arbitrary value of the topological charge, is given. In the case of CPnCP^n models a tower of integrable subsystems is obtained. In particular, in (2+1) dimensions a one-to-one correspondence between the standard integrable submodel and the BPS sector is proved. Additionally, it is shown that weak integrable submodels allow also for non-BPS solutions. Geometric as well as algebraic interpretations of the integrability conditions are also given.Comment: 23 page

    ActualizaciĂłn en radiologĂ­a dental: RadiologĂ­a convencional Vs digital

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    Desde su incorporación a la práctica odontológica la radiología digital ha experimentado un importante desarrollo. El continuo avance de las tecnologías en las que se sustenta ha dotado a estos sistemas de interesantes prestaciones que pueden facilitar el diagnóstico y manejo de imágenes radiográficas. Con estos avances la radiología digital ha despertado un interés creciente entre los profesionales de la odontología, especialmente durante los últimos años, en los que ha aumentado notoriamente tanto la cantidad de sistemas comercializados como el número de odontólogos que han decidido sustituir la radiología convencional por un sistema digital en sus clínicas. En esta revisión de la literatura se tratará de ofrecer una visión actualizada de los distintos sistemas disponibles en la actualidad, así como una comparativa entre ellos basada en estudios publicados recientemente. Since its appearance in dentistry, digital radiology has experienced a notorious development. A constant advance in the corresponding technologies has enhanced these digital systems with interesting features which may facilitate radiological diagnosis and image management. Due to these advances digital radiology has elicited a growing interest in dentistry. Specially during the last years there has been an increase both in the amount of available systems and in the number of dentists who have incorporated a digital system in their offices. This literature review aims to offer an updated view of the available systems and a comparison of them based in recent studies

    EvoluciĂłn de la relaciĂłn entre atenciĂłn primaria y especializada 1992-2001: estudio Delphi

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    ObjetivoValorar la tendencia en la relación de atención primaria (AP) y especializada (hospital) en 2 momentos diferentes de la reforma sanitaria, al inicio (1992) y tras una fase de consolidación (2001).DiseñoEstudio cualitativo basado en la técnica Delphi modificada.EmplazamientoComunidad Valenciana.ParticipantesSe seleccionó a un total de 196 profesionales de la Comunidad Valenciana (103 coordinadores de AP, 43 directores médicos hospitalarios y de AP, y 50 jefes de servicio de medicina interna/urgencias).ResultadosSe enviaron 196 cuestionarios, con una tasa de respuesta del 38%. Desde AP los problemas se mantienen, con un empeoramiento en la desmotivación del personal sanitario (+1,34), la falta de visión integral del paciente (+1,10) y la masificación asistencial (+1,06), y un mejoría en la presencia de especialistas de ambulatorio no integrados (–1,32). Desde el ámbito hospitalario empeora la falta de visión integral del paciente (+0,51), pero destaca la mejoría generalizada de los problemas, sobre todo la falta de comunicación y diálogo (–1,14). Las soluciones que aumentan su demanda desde AP son una historia clínica única informatizada (+1,50), la elaboración de protocolos comunes (+0,86) y las rotaciones periódicas de los médicos de AP (MAP) por servicios hospitalarios (+0,85), con una disminución de las derivaciones burocráticas a AP (–0,60) y la necesidad de especialistas en AP como consultores (–0,36). Desde el ámbito hospitalario, todas las soluciones disminuyen su valoración y entre ellas destaca facilitar el acceso de MAP para el seguimiento de los pacientes ingresados (–2,44) y la realización de guardias hospitalarias por MAP (–2,30).ConclusionesLos problemas y las soluciones siguen siendo los mismos que en 1992, pero en AP se observa una tendencia a empeorar y en el ámbito hospitalario se detecta una visión más positiva.AimTo evaluate the trends in the inter-professional relationship between primary health care (PHC) and secondary care (hospital) at 2 different moments of the health reform, at its start in 1992 and after a phase of consolidation (2001).DesignObservational study based on modified Delphi technique.SettingValencia Community, Spain.ParticipantsOne hundred and ninety six professionals from Valencia Community were selected (103 PH centre administrators, 43 hospital and PC medical directors, and 50 heads of internal medicine or emergency services).ResultsOne hundred and ninety six questionnaires were sent out, with a response rate of 38%. In PHC problems remained the same, but the following got worse: “lack of motivation” (+1.34), “lack of overall vision of patients” (+1.10), and “overuse of medical services” (+1.06). The existence of non-integrated out-patient specialists got better (–1.32). In hospitals, “lack of overall vision of patients” got worse (+0.51), but in general problems got better, especially in “lack of communication and dialogue” (–1.14). PC increased its demand for “a single computerized clinical record” (+1.50), drawing up of common protocols (+0.86), and periodic rotations of PC doctors through hospitals (+0.85), but bureaucratic referrals to PC (–0.60) and the need for specialists in PC as consultants (-0.36) diminished. In hospitals all solutions showed lower scores, particularly access of PC doctors to monitoring of admitted patients (–2.44) and PC doctors doing hospital cover (–2.30).ConclusionsProblems and solutions from PHC and hospitals remain the same, but there is a trend to the worse in PHC, whereas in hospitals the trend is more positive

    Time for global action: an optimised cooperative approach towards effective climate change mitigation

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    The difficulties in climate change negotiations together with the recent withdrawal of the U.S. from the Paris Agreement call for new cooperative mechanisms to enable a resilient international response. In this study we propose an approach to aid such negotiations based on quantifying the benefits of interregional cooperation and distributing them among the participants in a fair manner. Our approach is underpinned by advanced optimisation techniques that automate the screening of millions of alternatives for differing levels of cooperation, ultimately identifying the most cost-effective solutions for meeting emission targets. We apply this approach to the Clean Power Plan, a related act in the U.S. aiming at curbing carbon emissions from electricity generation, but also being withdrawn. We find that, with only half of the states cooperating, the cost of electricity generation could be reduced by US$41 billion per year, while simultaneously cutting carbon emissions by 68% below 2012 levels. These win–win scenarios are attained by sharing the emission targets and trading electricity among the states, which allows exploiting regional advantages. Fair sharing of dividends may be used as a key driver to spur cooperation since the global action to mitigate climate change becomes beneficial for all participants. Even if global cooperation remains elusive, it is worth trying since the mere cooperation of a few states leads to significant benefits for both the U.S. economy and the climate. These findings call on the U.S. to reconsider its withdrawal but also boost individual states to take initiative even in the absence of federal action
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