Evolución conceptual de los protocolos de puentes transparentes

Los puentes Ethernet transparentes son un elemento cada vez más importante en las redes\ud de telecomunicaciones. Este artículo ofrece una visión panorámica de la evolución conceptual de los\ud paradigmas de puentes durante las últimas décadas, desde los puentes transparentes con árbol de\ud expansión hasta las propuestas actualmente en estandarización: por una parte Shortest Path Bridges,\ud Provider Bridges y Provider Backbone Bridges en el IEEE 802.1; por otra parte Routing Bridges en el\ud IETF. Estas propuestas buscan aumentar la escalabilidad y obtener una alta utilización de la infraestructura\ud de red, así como la provisión de servicios basados en Ethernet a gran número de usuarios. Mediante\ud un mapa genealógico y una tabla se resumen e ilustran los aspectos funcionales, la evolución de los\ud puentes propuestos en cuanto a los mecanismos básicos empleados para el encaminamiento, reenvío\ud y la prevención de bucles tales como protocolos de vector distancia y de estado de enlaces, árboles\ud múltiples de expansión, jerarquización mediante encapsulado de tramas y prohibición de algunos giros\ud en los nodos. La evolución reciente de las propuestas muestra claramente varias tendencias: el predominio\ud de los protocolos de estado de enlaces como IS-IS para el encaminamiento y/o construcción de\ud árboles múltiples, de los mecanismos de encapsulado, y la multiplicación de tipos de identificadores\ud para etiquetar y procesar separada y homogéneamente miles de servicios y clientes

Individual efficiency for the use of feed resources in rabbits

[EN] A Bayesian procedure, which allows consideration of the individual variation in the feed resource allocation pattern, is described and implemented in 2 sire lines of rabbit (Caldes and R). The procedure is based on a hierarchical Bayesian scheme, where the first stage of the model consists of a multiple regression model of feed intake on metabolic BW and BW gain. In a second stage, an animal model was assumed including batch, parity order, litter size, and common environmental litter effects. Animals were reared during the fattening period (from weaning at 32 d of age to 60 d of age) in individual cages on an experimental farm, and were fed ad libitum with a commercial diet. Body weight (g) and cumulative feed intake (g) were recorded weekly. Individual BW gain (g) and average BW (ABW, g) were calculated from these data for each 7-d period. Metabolic BW (g(0.75)) was estimated as ABW(0.75). The number of animals actually measured was 444 and 445 in the Caldes and R lines, respectively. Marginal posterior distributions of the genetic parameters were obtained by Gibbs sampling. Posterior means (posterior SD) for heritabilities for partial coefficients of regression of feed intake on metabolic BW and feed intake on BW gain were estimated to be 0.35 (0.17) and 0.40 (0.17), respectively, in the Caldes line and 0.26 (0.19) and 0.27 (0.14), respectively, in line R. The estimated posterior means (posterior SD) for the proportion of the phenotypic variance due to common litter environmental effects of the same coefficients of regression were respectively, 0.39 (0.14) and 0.28 (0.13) in the Caldes line and 0.44 (0.22) and 0.49 (0.14) in line R. These results suggest that efficiency of use of feed resources could be improved by including these coefficients in an index of selection.Research was supported by INIA SC00-011. The authors acknowledge comments and suggestions made by M. Baselga and A. Blasco from the Universidad Politécnica de Valencia (Spain) and R. Rekaya for his assistance in solving numerical problems.Piles, M.; García-Tomas, M.; Rafel, O.; Ibañez Escriche, N.; Ramon, J.; Varona, L. (2007). Individual efficiency for the use of feed resources in rabbits. Journal of Animal Science. 85(11):2846-2853. https://doi.org/10.2527/jas.2006-218S284628538511Blasco, A. (2001). The Bayesian controversy in animal breeding. Journal of Animal Science, 79(8), 2023. doi:10.2527/2001.7982023xBlasco, A., Piles, M., & Varona, L. (2003). A Bayesian analysis of the effect of selection for growth rate on growth curves in rabbits. Genetics Selection Evolution, 35(1). doi:10.1186/1297-9686-35-1-21Cameron, N. D., & Thompson, R. (1986). Design of multivariate selection experiments to estimate genetic parameters. Theoretical and Applied Genetics, 72(4), 466-476. doi:10.1007/bf00289528Estany, J., Camacho, J., Baselga, M., & Blasco, A. (1992). Selection response of growth rate in rabbits for meat production. Genetics Selection Evolution, 24(6), 527. doi:10.1186/1297-9686-24-6-527Gelman, A., & Rubin, D. B. (1992). Inference from Iterative Simulation Using Multiple Sequences. Statistical Science, 7(4), 457-472. doi:10.1214/ss/1177011136Geyer, C. J. (1992). Practical Markov Chain Monte Carlo. Statistical Science, 7(4), 473-483. doi:10.1214/ss/1177011137Gianola, D., & Sorensen, D. (2004). Quantitative Genetic Models for Describing Simultaneous and Recursive Relationships Between Phenotypes. Genetics, 167(3), 1407-1424. doi:10.1534/genetics.103.025734MIGNON-GRASTEAU, S. (1999). Genetic parameters of growth curve parameters in male and female chickens. British Poultry Science, 40(1), 44-51. doi:10.1080/00071669987827Paracchini, V., Pedotti, P., & Taioli, E. (2005). Genetics of Leptin and Obesity: A HuGE Review. American Journal of Epidemiology, 162(2), 101-114. doi:10.1093/aje/kwi174Piles, M., Gianola, D., Varona, L., & Blasco, A. (2003). Bayesian inference about parameters of a longitudinal trajectory when selection operates on a correlated trait1. Journal of Animal Science, 81(11), 2714-2724. doi:10.2527/2003.81112714xPiles, M., Gomez, E. A., Rafel, O., Ramon, J., & Blasco, A. (2004). Elliptical selection experiment for the estimation of genetic parameters of the growth rate and feed conversion ratio in rabbits1. Journal of Animal Science, 82(3), 654-660. doi:10.2527/2004.823654xRauw, W. M., Luiting, P., Verstegen, M. W. A., Vangen, O., & Knap, P. W. (2000). Differences in food resource allocation in a long-term selection experiment for litter size in mice 2. Developmental trends in body weight against food intake. Animal Science, 71(1), 39-47. doi:10.1017/s1357729800054874Rauw, W. M., Knap, P. W., Verstegen, M. W. A., & Luiting, P. (2002). Food resource allocation patterns in lactating females in a long-term selection experiment for litter size in mice. Genetics Selection Evolution, 34(1). doi:10.1186/1297-9686-34-1-83Rekaya, R., Carabaño, M. J., & Toro, M. A. (2000). Bayesian Analysis of Lactation Curves of Holstein-Friesian Cattle Using a Nonlinear Model. Journal of Dairy Science, 83(11), 2691-2701. doi:10.3168/jds.s0022-0302(00)75163-0Rekaya, R., Weigel, K. A., & Gianola, D. (2001). Hierarchical nonlinear model for persistency of milk yield in the first three lactations of Holsteins. Livestock Production Science, 68(2-3), 181-187. doi:10.1016/s0301-6226(00)00239-6Varona, L., Moreno, C., Garcia Cortes, L. A., & Altarriba, J. (1998). Bayesian Analysis of Wood’s Lactation Curve for Spanish Dairy Cows. Journal of Dairy Science, 81(5), 1469-1478. doi:10.3168/jds.s0022-0302(98)75711-xWakefield, J. C., Smith, A. F. M., Racine-Poon, A., & Gelfand, A. E. (1994). Bayesian Analysis of Linear and Non-Linear Population Models by Using the Gibbs Sampler. Applied Statistics, 43(1), 201. doi:10.2307/298612

Experimental validation of COMETA model of mental workload in air traffic control

The sustained increase in air traffic during the last decades represents a challenge to the air traffic management system in general. Thus, it is of utmost importance to develop strategies that can safely increase air traffic controller's handling capacity without increasing task related strain. This research proposes and validates a predictive model of air traffic controller's mental workload. Our model is based on COMETA, a model that considers the effect of the most relevant air traffic events in the cognitive complexity of the task. In the version of COMETA used in this study we include the online effects of the controllers' actions on the state of the airspace. To validate the model, a laboratory experiment was conducted using a simulator to precisely control the task workload factors. We used traffic density and airspace complexity as experimental factors because they are the most commonly acknowledged sources of mental workload in air traffic control literature. The measured dependent variables were selected because they have been found to correlate with mental workload in ATC tasks, namely, ISA and NASA indexes, electrodermal activity, heart rate, and different performance measures. The results demonstrate that our model can successfully predict air traffic controllers' mental workload across a wide range of task workload conditions. In addition, our results provide a clear portrait of the complex interactions between the different sources of task workload and their effects on mental workload. In the conclusion we consider the limitations and opportunities for the application of this model to improve policie

A simple deterministic Lorenz chaotic-based methodology to cipher and decipher information

We present in this paper a secure deterministic cipher and decipher mechanism based on the well known Lorenz's dynamic system. The cipher process is performed by the combination of the message to be cipher and the states of the Lorenz's dynamic system, which act as the cipher key. The decipher process is carried out by the reconstruction of the key, which is generated using a Lorenz's system state observer. The observed key is then used in the decipher process in order to recover the ciphered message.Sociedad Argentina de Informática e Investigación Operativ

A simple deterministic Lorenz chaotic-based methodology to cipher and decipher information

We present in this paper a secure deterministic cipher and decipher mechanism based on the well known Lorenz's dynamic system. The cipher process is performed by the combination of the message to be cipher and the states of the Lorenz's dynamic system, which act as the cipher key. The decipher process is carried out by the reconstruction of the key, which is generated using a Lorenz's system state observer. The observed key is then used in the decipher process in order to recover the ciphered message.Sociedad Argentina de Informática e Investigación Operativ

Highly functionalized 2-oxopiperazine-based peptidomimetics: An approach to PAR1 antagonists

A series of pseudodipeptide-based chiral 1,3,4,5-tetrasubstituted-2- oxopiperazines has been designed and synthesized as potential PAR1 antagonists. These highly functionalized piperazines were synthesized from aromatic and basic amino acid derived Ψ[CH(CN)NH]pseudodipeptides through a four step pathway that involves reduction of the cyano group to build the 2-oxopiperazine ring, followed by selective functionalization at the N4-, N 1-positions, and at the exocyclic moiety at position C5. This regioselective functionalization required the fine tuning of reaction conditions. All new compounds were screened as inhibitors of human platelet aggregation induced by the PAR1 agonist SFLLRN and as cytotoxic agents in human cancer cell lines. Some of the compounds displayed moderate PAR1 antagonist activity, while, others were cytotoxic at μM concentration. No correlation was observed between both types of activities.Peer Reviewe

A 3D joint interpretation of magnetotelluric and seismic tomographic models: the case of the volcanic island of Tenerife

In this work we have done a 3D joint interpretation of magnetotelluric and seismic tomography models. Previously we have described different techniques to infer the inner structure of the Earth. We have focused on volcanic regions, specifically on Tenerife Island volcano (Canary Islands, Spain). In this area, magnetotelluric and seismic tomography studies have been done separately. The novelty of the present work is the combination of both techniques in Tenerife Island. For this aim we have applied Fuzzy Clusters Method at different depths obtaining several clusters or classes. From the results, a geothermal system has been inferred below Teide volcano, in the center of Tenerife Island. An edifice hydrothermally altered and full of fluids is situated below Teide, ending at 600 m below sea level. From this depth the resistivity and VP values increase downwards. We also observe a clay cap structure, a typical feature in geothermal systems related with low resistivity and low VP values.Comment: Preprint of the published paper without figure

Detailed spectroscopy of doubly magic Sn-132

The structure of the doubly magic Sn-132(50)82 has been investigated at the ISOLDE facility at CERN, populated both by the beta(-) decay of In-132 and beta(-)-delayed neutron emission of In-133. The level scheme of Sn-13(2) is greatly expanded with the addition of 68 gamma transitions and 17 levels observed for the first time in the beta decay. The information on the excited structure is completed by new gamma transitions and states populated in the beta-n decay of In-133. Improved delayed neutron emission probabilities are obtained both for In-132 and In-133. Level lifetimes are measured via the advanced time-delayed beta gamma gamma(t) fast-timing method. An interpretation of the level structure is given based on the experimental findings and the particle-hole configurations arising from core excitations both from the N = 82 and Z = 50 shells, leading to positive- and negative-parity particle-hole multiplets. The experimental information provides new data to challenge the theoretical description of Sn-132

Diagnóstico sobre las bacterias rizosféricas asociadas al cultivo de caña de azúcar (Saccharum spp.)

Objective: Characterize the presence of rhizobacteria associated with three varieties of sugar cane: 9640 ATMEX, MEX 69-290 and the MEX SFC 9546, cultivated in the area of supplying the Pdte. Benito Juarez sugar mills (PBJ). Desing/methodology/approach: Three sites were selected for sampling by variety where soil samples were collected from 0 to 30 cm depth. For the isolation of the bacteria are followed by the serial dilution technique by viable. Results:The rhizosphere of the variety ATMEX-9640 presented the greatest number of CFU g-1. Ten of the 26 strains demonstrated capabilities of biological nitrogen fixation (BNF) or solubizacion of phosphorus (SP). Eight of them carried FBN already that degrade the malic acid in the NFb. Five are considered within the group of phosphorus solubilizing bacteria (BSP), because they solubilize the calcium phosphate of Pikovskaya medium. Limitations on study/implications: It was not possible to determine the production of AIA in the strains that grew in the Soya Tripticasa Broth medium. Findings/conclusions: The molecular identification revealed that these bacteria belong to the group of plant growth promoting rhizobacteria (PGPR) belonging Microbacterium, Bacillus y Paenibacillus genera present in the soil Cambisol Fluvic Éutric of the PBJ sugar mills.Objetivo: Evaluar la presencia de rizobacterias asociadas a tres cultivares de caña de azúcar: ATMEX 9640, MEX 69-290 y MEX SFC 9546, cultivados en la zona de abastecimiento del Ingenio Pdte. Benito Juárez (IPBJ). Diseño/Metodología/Aproximación: Se seleccionaron tres sitios de muestreo por cultivar donde se colectaron muestras de suelo de 0 a 30 cm de profundidad. Para el aislamiento de las bacterias se siguió la técnica de dilución seriada por cuenta viable. Resultados: La rizósfera del cultivar ATMEX 9640 presento el mayor número de UFC g-1. 10 de las 26 cepas manifestaron capacidades de fijación biológica de nitrógeno (FBN) o solubización de fósforo (SP). Ocho de ellas llevaron a cabo FBN ya que degradan el ácido málico en el medio NFb. Cinco se consideran dentro del grupo de bacterias solubilizadoras de fósforo (BSF), ya que solubiliza el fosfato de calcio del medio Pikovskaya. Limitaciones del estudio/implicaciones: No fue posible determinar la producción del AIA en las cepas que crecieron en el medio Caldo Tripticasa de Soya. Hallazgos/conclusiones: La identificación molecular reveló que estas bacterias corresponden al grupo de rizobacterias promotoras del crecimiento vegetal del genero Microbacterium, Bacillus y Paenibacillus sp presentes en el suelo Cambisol Fluvico Éutrico del IPBJ

Association of Sleep Duration and Quality With Subclinical Atherosclerosis.

BACKGROUND Sleep duration and quality have been associated with increased cardiovascular risk. However, large studies linking objectively measured sleep and subclinical atherosclerosis assessed in multiple vascular sites are lacking. OBJECTIVES The purpose of this study was to evaluate the association of actigraphy-measured sleep parameters with subclinical atherosclerosis in an asymptomatic middle-aged population, and investigate interactions among sleep, conventional risk factors, psychosocial factors, dietary habits, and inflammation. METHODS Seven-day actigraphic recording was performed in 3,974 participants (age 45.8 4.3 years; 62.6% men) from the PESA (Progression of Early Subclinical Atherosclerosis) study. Four groups were defined: very short sleep duration 8 h. Sleep fragmentation index was defined as the sum of the movement index and fragmentation index. Carotid and femoral 3-dimensional vascular ultrasound and cardiac computed tomography were performed to quantify noncoronary atherosclerosis and coronary calcification. RESULTS When adjusted for conventional risk factors, very short sleep duration was independently associated with a higher atherosclerotic burden with 3-dimensional vascular ultrasound compared to the reference group (odds ratio: 1.27; 95% confidence interval: 1.06 to 1.52; p ¼ 0.008). Participants within the highest quintile of sleep fragmentation presented a higher prevalence of multiple affected noncoronary territories (odds ratio: 1.34; 95% confidence interval: 1.09 to 1.64; p ¼ 0.006). No differences were observed regarding coronary artery calcification score in the different sleep groups. CONCLUSIONS Lower sleeping times and fragmented sleep are independently associated with an increased risk of subclinical multiterritory atherosclerosis. These results highlight the importance of healthy sleep habits for the prevention of cardiovascular disease. (J Am Coll Cardiol 2019;73:134–44) © 2019 Published by Elsevier on behalf of the American College of Cardiology Foundation.post-print454 K