512 research outputs found
Nonlinear field theories during homogeneous spatial dilation
The effect of a uniform dilation of space on stochastically driven nonlinear
field theories is examined. This theoretical question serves as a model problem
for examining the properties of nonlinear field theories embedded in expanding
Euclidean Friedmann-Lema\^{\i}tre-Robertson-Walker metrics in the context of
cosmology, as well as different systems in the disciplines of statistical
mechanics and condensed matter physics. Field theories are characterized by the
speed at which they propagate correlations within themselves. We show that for
linear field theories correlations stop propagating if and only if the speed at
which the space dilates is higher than the speed at which correlations
propagate. The situation is in general different for nonlinear field theories.
In this case correlations might stop propagating even if the velocity at which
space dilates is lower than the velocity at which correlations propagate. In
particular, these results imply that it is not possible to characterize the
dynamics of a nonlinear field theory during homogeneous spatial dilation {\it a
priori}. We illustrate our findings with the nonlinear Kardar-Parisi-Zhang
equation
Service-based network dimensioning for 5G networks assisted by real data
The fifth-generation (5G) of cellular communications is expected to be deployed in the next years to support a wide range of services with different demands of peak data rates, latency and quality of experience (QoE). In this work, we propose a novel approach for radio network dimensioning (RND), named as Heuristic RND (HRND), which uses real open data in the network dimensioning process. This procedure, named as NetDataDrilling, provides the dimensioning target area by means of network data selection and visualization from the existing infrastructure. Moreover, the proposed NetDimensioning heuristic considers the necessary parameters of numerology and bandwidth parts (BWP) supported by New Radio (NR) to provide a balanced network design mediating among the requirements of coverage, capacity, QoE and cost. The proposed HRND is based on the novel quality of experience (QoE) parameter ζ by probabilistically characterizing the 5G radio resource control (rrc) states to ensure the availability of peak data rates for the MNO's required percentage of the time. The simulation results show the fulfilment of QoE and load balancing parameters with significant cost savings compared to the conventional RND methodology.This work was supported by the Spanish National Project TERESA-ADA (MINECO/AEI/R, UE), under Grant TEC2017-90093-C3-2-R
Unsupervised clustering for 5G network planning assisted by real data
The fifth-generation (5G) of networks is being deployed to provide a wide range of new services and to manage the accelerated traffic load of the existing networks. In the present-day networks, data has become more noteworthy than ever to infer about the traffic load and existing network infrastructure to minimize the cost of new 5G deployments. Identifying the region of highest traffic density in megabyte (MB) per km2 has an important implication in minimizing the cost per bit for the mobile network operators (MNOs). In this study, we propose a base station (BS) clustering framework based on unsupervised learning to identify the target area known as the highest traffic cluster (HTC) for 5G deployments. We propose a novel approach assisted by real data to determine the appropriate number of clusters k and to identify the HTC.
The algorithm, named as NetClustering, determines the HTC and appropriate value of k by fulfilling MNO's requirements on the highest traffic density MB/km2 and the target deployment area in km2. To compare the appropriate value of k and other performance parameters, we use the Elbow heuristic as a benchmark. The simulation results show that the proposed algorithm fulfills the MNO's requirements on the target
deployment area in km2 and highest traffic density MB/km2 with significant cost savings and achieves higher network utilization compared to the Elbow heuristic. In brief, the proposed algorithm provides a more meaningful interpretation of the underlying data in the context of clustering performed for network planningThis work was supported by the Spanish National Project IRENE-EARTH (PID2020-115323RB-C33/AEI/10.13039/501100011033
Amino acids content in 'Tempranillo' must from three soil types over four vintages
Amino acids are the main grape nitrogen compounds and the principal source of N for yeasts, being precursors of several volatile compounds. Therefore, N compound concentrations in musts can affect sensorial characteristics of wines. The aim of this study was to analyse the influence of N-NO3- and N-NH4+ contents from different soils on profile and content of amino acids in 'Tempranillo' grapes. In order to determine this soil influence on must quality, three plots were selected in AOC Rioja, classified as Fluventic Haploxerepts, Typic Calcixerepts, and Petrocalcic Palexerolls. The results showed that amino acids and yeast assimilable nitrogen (YAN) content allowed us to differentiate samples from the three soils, and in each soil type, samples of each season. In general, must contents of total amino acids and some of them, as alanine, threonine, and tyrosine, were more influenced by soil type; YAN, proline, histidine, serine, and glycine concentrations mainly depended on the interaction soil-vintage. In conclusion, free amino acids concentration could be a tool to differentiate musts coming from different soils
Mesothelial versus endothelial cell seeding: evaluation of cell adherence to a fibroblastic matrix using 111In oxine
The aim of this study was to compare the behaviour of mesothelial cells (MC) to that of endothelial cells (EC) when seeded onto a PTFE, prosthesis coated with a fibroblastic matrix.
Three study groups were examined: a control group (Control) of PTFE prostheses with a fibroblast matrix (n = 8); Group EC, PTFE prostheses seeded with EC on a fibroblastic matrix (n = 8); and Group MC, PTFE, prostheses seeded with MC on a fibroblastic matrix (n = 8). All cell types were labelled with 111In (100 microCi/ml) 24 h after seeding, when the cells had formed a monolayer on the prosthetic surface. Radioactive levels were measured at 2, 4, 6, and 24 h.
Both EC and MC showed optimal adherence. The MC had a better radioactive uptake and retention than the EC. The number of EC and MC cells that remained adherent to the matrix was large enough to ensure complete covering of the prosthetic surface.
The use of MC is therefore feasible as an optimal alternative for achieving a natural covering on vascular prostheses prepared with a fibroblastic matrix
Coating PTFE vascular prostheses with a fibroblastic matrix improves cell retention when subjected to blood flow.
An investigation was made into the effect of blood flow on endothelial cells (EC) and mesothelial cells (MC) seeded on a vascular expanded polytetrafluoroethylene (ePTFE) prosthesis coated with a fibroblastic matrix. Endothelial cells were obtained from the external jugular vein and MC from the omentum. To test the performance of prostheses, a custom designed, femoral "ex vivo" circuit was developed in mongrel dogs. Four study groups were established: a control group, A1, where prostheses were uncoated and seeded with EC; a second control group, A2, where prostheses were uncoated and seeded with MC; group B1 where prostheses were coated with a fibroblastic matrix and seeded with EC; and group B2 where coated prostheses were seeded with MC. All cells were labeled with 111Indium oxine (10 microCi/mL) before seeding. After the seeded cells had formed a monolayer on the ePTFE prostheses (which took approximately 24 h) the prostheses were placed in the "ex vivo" circuit. The rates of blood flow to which prostheses were exposed were measured at the point of inflow (117.5 +/- 12.50 mL/min, mean +/- SD) and outflow (72.6 +/- 14.3 mL/min). MC showed a greater baseline radionuclide uptake than did EC. The cells of groups B1 and B2 adhered sufficiently to the fibroblastic matrix and covered enough of the prosthetic surface to be positioned in the "ex vivo" circuit (76.90 +/- 8.24% surface covered in EC-seeded prostheses and 71.65 +/- 6.23% in MC-seeded prostheses). After exposure to blood flow the quantity of radionuclide-labeled cells and the prosthetic surface covered by them were greatly reduced though the fibroblast-coated prostheses showed greater cell retention
Contrastación de hipótesis en diseños multivariados split-plot con matrices de dispersión arbitrarias
El presente trabajo examina diversos procedimientos para contrastar hipótesis nulas globales, correspondientes a datos obtenidos mediante diseños multivariados split-plot cuando se incumple el supuesto de homogeneidad de las matrices de dispersión. Un examen de estos procedimientos para un amplio número de variables confirma, por un lado, la robustez del procedimiento multivariado de Welch-James dado por Johansen (1980) para probar el efecto principal de los ensayos y, por otro, la robustez de la generalización multivariada del procedimiento de Brown-Forsythe (1974) para probar la interacción de los grupos x los ensayos. Nuestros resultados también ponen de relieve que las diferencias de potencia eran pequeñas en aquellas condiciones en que tanto el procedimiento de Welch-James como de Brown-Forsythe controlaban las tasas de error de Tipo I
Estudio de la marcha en pacientes tratados ortopédicamente de fractura unilateral del calcáneo
Veinticinco pacientes afectos de fractura unilateral desplazada articular de calcá-
neo fueron tratados mediante inmovilización con yeso, siendo los resultados a los 6 años (rango:
3-10), excelentes en 5 pacientes, buenos en 4, regulares en 7 y malos en 9. De este grupo se excluyeron
los afectos de patología local o general asociada, siendo útiles para el estudio de la marcha
12 pacientes a los que se les hizo deambular sobre plataformas dinamométricas para registrar
la fuerza de reacción al suelo, demostrando una disminución de la fuerza vertical de apoyo y
despegue (F1 y F3) y un aumento estadísticamente significativo del tiempo de apoyo total durante
la marcha. Abogamos por la restitución anatómica del calcáneo como medio para mejorar la
capacidad funcional del paciente.Twenty-five patients with unilateral displaced joint calcaneus fracture were treated
by cast being the results after 6 years (range: 3-10), excellent in 5 patients, good in 4 patients,
poor in 7 and bad in 9. We excluded for the study the patients with associated local or general
pathology being useful for our study 12 patients. These patients walked on a dynamometric platform
in order to analyse floor reaction forces, proving a diminuí ion of vertical support and takeoff
forces (Fl and F2), and statistically significant a increase of total support phase during gait
Estudio comparativo de la fijación con o sin cemento en Prótesis Total de Rodilla
Revisamos retrospectivamente una serie de 86 pacientes portadores de 110
prótesis totales modulares de rodilla colocadas como tratamiento de la gonartrosis. Se analizan
los resultados obtenidos en los pacientes a los que se le realizó una fijación híbrida cementada
(componente femoral no cementado y componente tibial y patelar cementado) respecto a los
que se le realizó una prótesis de anclaje biológico sin ningún tipo de cementación. El análisis
de la función clínica, movilidad de la rodilla, estudio radiológico y complicaciones de ambas series
no demuestran diferencias significativas entre ambos grupos con un periodo de seguimiento
de 45 meses (r=12-60).We have retrospectively review 86 patients with 110 total knee arthroplasty for
the treatment of osteoarthrosis. We have analyzed the results obtained in a group of patients
with partial fixation with cement and another group fixated without any cement. Clinical and
radiological results and complications in both groups were similar without significant differences
with an average follow-up of 45 months (12-60)
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