3,258 research outputs found

    Joint scheduling and coding for low in-order delivery delay over lossy paths with delayed feedback

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    We consider the transmission of packets across a lossy end-to-end network path so as to achieve low in-order delivery delay. This can be formulated as a decision problem, namely deciding whether the next packet to send should be an information packet or a coded packet. Importantly, this decision is made based on delayed feedback from the receiver. While an exact solution to this decision problem is challenging, we exploit ideas from queueing theory to derive scheduling policies based on prediction of a receiver queue length that, while suboptimal, can be efficiently implemented and offer substantially better performance than state of the art approaches. We obtain a number of useful analytic bounds that help characterise design trade-offs and our analysis highlights that the use of prediction plays a key role in achieving good performance in the presence of significant feedback delay. Our approach readily generalises to networks of paths and we illustrate this by application to multipath trans port scheduler design.This work has been supported by the Spanish Government (Ministerio de EconomĂ­a y Competitividad, Fondo Europeo de Desarrollo Regional, FEDER) by means of the project ADVICE (TEC2015-71329-C2-1-R)

    Region-based layout analysis of music score images

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    The Layout Analysis (LA) stage is of vital importance to the correct performance of an Optical Music Recognition (OMR) system. It identifies the regions of interest, such as staves or lyrics, which must then be processed in order to transcribe their content. Despite the existence of modern approaches based on deep learning, an exhaustive study of LA in OMR has not yet been carried out with regard to the performance of different models, their generalization to different domains or, more importantly, their impact on subsequent stages of the pipeline. This work focuses on filling this gap in the literature by means of an experimental study of different neural architectures, music document types, and evaluation scenarios. The need for training data has also led to a proposal for a new semi-synthetic data-generation technique that enables the efficient applicability of LA approaches in real scenarios. Our results show that: (i) the choice of the model and its performance are crucial for the entire transcription process; (ii) the metrics commonly used to evaluate the LA stage do not always correlate with the final performance of the OMR system, and (iii) the proposed data-generation technique enables state-of-the-art results to be achieved with a limited set of labeled data.This paper is part of the I+D+i PID2020-118447RA-I00 (MultiScore) project funded by MCIN/AEI/10.13039/501100011033, Spain and the GV/2020/030, Spain project funded by the Generalitat Valenciana, Spain. The first and third authors acknowledge support from the “Programa I+D+i de la Generalitat Valenciana, Spain ” through grants ACIF/2019/042 and ACIF/2021/356, respectively

    Increased circulating adiponectin levels and decreased leptin/soluble leptin receptor ratio throughout puberty in female ballet dancers:association with body composition and delay in puberty

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    Introduction: Ballet dancers (BDs) have a negative energy balance related to physical training that results in alterations in body composition, sexual development, and adipokine secretion. Our aims were to study anthropometric parameters, body composition, and their relationship with adipokines throughout pubertal development. Subjects and methods: We carried out a prospective follow-up study of 22 female Caucasian BDs (Tanner II stage) followed throughout puberty. Nutritional status was determined by measurement of height, weight, and body mass index (BMI). We calculated growth velocity, bone maturity, and body composition at Tanner stages II, III, and V by dual energy X-ray absorptiometry. Circulating leptin, adiponectin, and soluble leptin receptor (sObR) levels were determined. Results: BDs presented a delay in skeletal maturation during puberty, without affectation of final height. Energy intake was deficient according to their physical exercise, and they had a delay of 1 year in the mean age of menarche. Leptin levels were decreased, whereas sObR and adiponectin levels were increased throughout puberty. The percentage of trunk fat, total fat mass, and fat of the extremities was decreased throughout the study period (P<0.01). Lean mass was increased in the lower extremities, and bone mineral density was normal. Conclusion: A negative energy balance together with maintained physical exercise induced modifications in body composition in BDs. Changes in leptin and adiponectin levels appear to be more related to total fat content than to BMI. Furthermore, the onset and delayed progress of puberty may be related with an inadequate energy balance due to increased exercise

    Pharmacokinetic-pharmacodynamic modeling of the antinociceptive effects of main active metabolites of tramadol, (+)-O-desmethyltramadol and (-)-O-desmethyltramadol, in rats.

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    The pharmacokinetics and pharmacodynamics of the two main metabolites of tramadol, (+)-O-desmethyltramadol and (-)-O-desmethyltramadol, were studied in rats. Pharmacodynamic endpoints evaluated were respiratory depression, measured as the change in arterial blood pCO(2), pO(2), and pH levels; and antinociception, measured by the tail-flick technique. The administration of 10 mg/kg (+)-O-desmethyltramadol in a 10-min i.v. infusion significantly altered pCO(2), pO(2), and pH values in comparison with baseline and lower-dose groups (P <.05). However, 2 mg/kg administered in a 10-min i.v. infusion was enough to achieve 100% antinociception without respiratory depression. Moreover, the beta-funaltrexamine pretreatment completely eliminated the antinociception of the 2-mg/kg dose, suggesting that such an effect is due to mu-opioid receptor activation. To describe and adequately characterize the in vivo antinociceptive effect of the drug, (+)-O-desmethyltramadol was given at different infusion rates of varying lengths (10-300 min). Pharmacokinetics was best described by a two-compartmental model. The time course of response was described using an effect compartment associated with a linear pharmacodynamic model. The estimates of the slope of the effect versus concentration relationship were significantly decreased (P <. 05) as the length of infusion was increased, suggesting the development of tolerance. Doses of up to 8 mg/kg (-)-O-desmethyltramadol given in 10-min i.v. infusion did not elicit either antinociception in the tail-flick test or respiratory effects. These in vivo results are in accordance with the opiate and nonopiate properties reported for these compounds in several in vitro studies

    Effect of different coating-forming agents on the efficacy of the biocontrol agent Candida sake CPA-1 for control of Botrytis cinerea on grapes

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    [EN] Multiple formulations of known biocontrol agent (BCA) Candida sake, containing different coatingforming polymers and surfactants were tested at different polymer:BCA ratios, in order to improve control of Botrytis cinerea on grapes. The BCA cell viability on the grape surface was analyzed and reduction in disease incidence and severity was determined. Coating-forming solids improved the survival and effi- cacy of C. sake as a BCA against B. cinerea, depending on the polymer type and ratio. The incorporation of surfactants did not improve survival or disease control, although they promoted a better cell dispersion on the grape surface. Cell growth of the antagonist during incubation led to the formation of aggregates, even when surfactants were present. Sodium caseinate and starch were the most suitable polymers to formulate C. sake preparations to obtain coating-forming systems with this BCA and to increase its survival and efficacy at the minimum economic cost of the ingredients. 2016 Elsevier Inc. All rights reservedThe authors are grateful to the Spanish Government for the financial support from the national project RTA2012-00067-C02 (Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria, Spain and FEDER founds) and to the Conselleria d'Educacio of the Generalitat Valenciana, (Spain) for A. Marin's PhD grant.Marín-Gozalbo, A.; Chåfer Nåcher, MT.; Atarés Huerta, LM.; Chiralt, A.; Torres, R.; Usall, J.; Teixidó, N. (2016). Effect of different coating-forming agents on the efficacy of the biocontrol agent Candida sake CPA-1 for control of Botrytis cinerea on grapes. Biological Control. 96:108-119. https://doi.org/10.1016/j.biocontrol.2016.02.012S1081199

    Angular momentum-Large-scale structure alignments in LCDM models and the SDSS

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    We study the alignments between the angular momentum of individual objects and the large-scale structure in cosmological numerical simulations and real data from the Sloan Digital Sky Survey, Data Release 6. To this end we measure anisotropies in the two point cross-correlation function around simulated halos and observed galaxies, studying separately the 1- and 2-halo regimes. The alignment of the angular momentum of dark-matter haloes in LCDM simulations is found to be dependent on scale and halo mass. At large distances (2-halo regime), the spins of high mass haloes are preferentially oriented in the direction perpendicular to the distribution of matter; lower mass systems show a weaker trend that may even reverse to show an angular momentum in the plane of the matter distribution. In the 1-halo term regime, the angular momentum is aligned in the direction perpendicular to the matter distribution; the effect is stronger than for the 1-halo term and increases for higher mass systems. On the observational side, we focus our study on galaxies in the Sloan Digital Sky Survey, Data Release 6 (SDSS-DR6) with elongated apparent shapes, and study alignments with respect to the major semi-axis. We find an excess of structure in the direction of the major semi-axis for all samples; the red sample shows the highest alignment (2.7+-0.08%) and indicates that the angular momentum of flattened spheroidals tends to be perpendicular to the large-scale structure. (Abridged)Comment: 10 pages, 6 figures, accepted for publication in MNRAS; the definitive version is available at www.blackwell-synergy.co

    Measurement off f(s)/f(u) Variation with Proton-Proton Collision Energy and B-Meson Kinematics

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    The ratio of the B0s and B+ fragmentation fractions fs and fu is studied with B0s→J/ψϕ and B+→J/ψK+ decays using data collected by the LHCb experiment in proton-proton collisions at 7, 8, and 13 TeV center-of-mass energies. The analysis is performed in bins of B-meson momentum, longitudinal momentum, transverse momentum, pseudorapidity, and rapidity. The fragmentation-fraction ratio fs/fu is observed to depend on the B-meson transverse momentum with a significance of 6.0σ. This dependency is driven by the 13 TeV sample (8.7σ), while the results for the other collision energies are not significant when considered separately. Furthermore, the results show a 4.8σ evidence for an increase of fs/fu as a function of collision energy

    Search for the doubly heavy Ξbc0 baryon via decays to D 0 pK −

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    A search for the doubly heavy Ξ0bc baryon using its decay to the D0pK- final state is performed using proton-proton collision data at a centre-of-mass energy of 13 TeV collected by the LHCb experiment between 2016 and 2018, corresponding to an integrated luminosity of 5.4 fb−1. No significant signal is found in the invariant mass range from 6.7 to 7.2 GeV/c2. Upper limits are set at 95% credibility level on the ratio of the Ξ0bc production cross-section times its branching fraction to D0pK− relative to that of the Λ0b→D0pK− decay. The limits are set as a function of the Ξ0bc mass and lifetime hypotheses, in the rapidity range from 2.0 to 4.5 and in the transverse momentum region from 5 to 25 GeV/c. Upper limits range from 1.7 × 10−2 to 3.0 × 10−1 for the considered Ξ0bc mass and lifetime hypotheses
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