Diffusive transport in networks built of containers and tubes

We developed analytical and numerical methods to study a transport of non-interacting particles in large networks consisting of M d-dimensional containers C_1,...,C_M with radii R_i linked together by tubes of length l_{ij} and radii a_{ij} where i,j=1,2,...,M. Tubes may join directly with each other forming junctions. It is possible that some links are absent. Instead of solving the diffusion equation for the full problem we formulated an approach that is computationally more efficient. We derived a set of rate equations that govern the time dependence of the number of particles in each container N_1(t),N_2(t),...,N_M(t). In such a way the complicated transport problem is reduced to a set of M first order integro-differential equations in time, which can be solved efficiently by the algorithm presented here. The workings of the method have been demonstrated on a couple of examples: networks involving three, four and seven containers, and one network with a three-point junction. Already simple networks with relatively few containers exhibit interesting transport behavior. For example, we showed that it is possible to adjust the geometry of the networks so that the particle concentration varies in time in a wave-like manner. Such behavior deviates from simple exponential growth and decay occurring in the two container system.Comment: 21 pages, 18 figures, REVTEX4; new figure added, reduced emphasis on graph theory, additional discussion added (computational cost, one dimensional tubes

Time walkers and spatial dynamics of ageing information

The distribution of information is essential for living system's ability to coordinate and adapt. Random walkers are often used to model this distribution process and, in doing so, one effectively assumes that information maintains its relevance over time. But the value of information in social and biological systems often decay and must continuously be updated. To capture the spatial dynamics of ageing information, we introduce time walkers. A time walker moves like a random walker, but interacts with traces left by other walkers, some representing older information, some newer. The traces forms a navigable information landscape. We quantify the dynamical properties of time walkers moving on a two-dimensional lattice and the quality of the information landscape generated by their movements. We visualise the self-similar landscape as a river network, and show that searching in this landscape is superior to random searching and scales as the length of loop-erased random walks

Dogs as a source of Salmonella spp. in apparently healthy dogs in the Valencia Region. Could it be related with intestinal lactic acid bacteria?

Altres ajuts: Banco Santander (ES), FUSPBS-PPC 15/2016Although salmonellosis is considered one of the most important food-borne zoonotic diseases in Europe, close contact between dogs and their owners can also be a potential source of Salmonella spp. for humans. This study assessed the prevalence and antimicrobial resistance of Salmonella spp. in apparently healthy dogs in the Valencian Region, eastern Spain. Moreover, a macroscopic comparison of lactic acid bacteria in both Salmonella -positive and Salmonella -negative dogs was carried out. Of a total of 325 dogs sampled, 6 (1.85%) were positive for Salmonella spp. with 3 different serotypes, Havana (3), Mikawasima (2) and monophasic Typhimurium (1). All isolates were susceptible to all antimicrobials tested except monophasic S. Typhimurium, which was resistant to ampicillin. Finally, macroscopic results revealed that lactic acid bacteria had higher heterogeneity in the Salmonella -negative dogs than in the Salmonella -positive dogs. Although the results in our study showed a low prevalence of Salmonella spp., raw food has been suggested as a risk factor for bacteria in dog faeces. Public awareness campaigns on good hygiene practices, especially after handling canine faeces or raw food, are necessary. Furthermore, to reduce the potential transmission of bacteria, dogs should be fed food that has been properly cooked, as raw or undercooked food can be a source of zoonotic pathogens. Moreover, further studies must be performed to determine the relationship between lactic acid bacteria and Salmonella spp. in dog faeces

Impact of the covid-19 pandemic on teacher quality of life: A longitudinal study from before and during the health crisis

Background: Prior to the COVID-19 pandemic, teachers were already reporting a low quality of life (QoL) perception, with a significant impact on mental and physical health due to various stress factors associated with work overload. The objective of this study was to evaluate the QoL impact on Chilean teachers before and during the COVID-19 pandemic. The analysis was performed following a longitudinal design on a sample of 63 Chilean teachers in pre-pandemic and COVID-19 pandemic timeframes. QoL perception, along with teachers’ sociodemographic data, was evaluated via the Short-Form 36 Health Survey (SF-36) questionnaire. Sociodemographic variables presented no significant variations in pre-pandemic and pandemic comparisons. QoL, however, showed a significant decrease during the pandemic compared to the pre-pandemic measurement (p < 0.01). In each gender, there were significant differences between pre-pandemic and pandemic timeframes, with a greater impact among women in the mental and physical component summary variables and seven of the eight QoL scales (p < 0.01). Between age categories, people under 45 presented significant differences (p < 0.05) between pre-pandemic and pandemic timeframes in all summary dimensions and measurements. In conclusion, Chilean teachers’ QoL perception has been affected by the COVID-19 pandemic. These findings could be related to work overload due to teleworking or feelings of uncertainty, loneliness, and fear that the pandemic and its associated confinements will worsen

Preinvex functions and weak efficient solutions for some vectorial optimization problem in Banach spaces

AbstractIn this work, we introduce the notion of preinvex function for functions between Banach spaces. By using these functions, we obtain necessary and sufficient conditions of optimality for vectorial problems with restrictions of inequalities. Moreover, we will show that this class of problems has the property that each local optimal solution is in fact global

Un consejero valenciano del siglo XV: Pero Maça de Liçana i d’Alagó

Biographic studies of a knight of noble lineage in the 15th century, don Pero Maça de Liçana i d’Alagó, who took up residence in Valencia and serve to three kings in the «Crown of Aragon », Martín I El Humano, Fernando I El de Antequera and Alfonso V El Magnánimo, been as Councilor and Majordomo of the two last ones. He was a man-at-arms, a career soldier from the 15th century, expert in guerrilla war, who was practice at an early stage in the noble armed struggle, a real plague at Valencia in the 15th century.Estudio biográfico de un personaje noble del siglo XV, don Pero Maça de Liçana i d’Alagó, establecido en el reino de Valencia, que sirvió a tres reyes de la Corona de Aragón, Martín I El Humano, Fernando I El de Antequera y Alfonso V El Magnánimo, siendo Consejero y Mayordomo de estos dos últimos. Fue un hombre de armas, un militar del siglo XV experto en la «guerra de guerrillas» que practicó desde muy joven en las numerosas luchas señoriales, auténtica plaga en la Valencia del siglo XV.Biographic studies of a knight of noble lineage in the 15th century, don Pero Maça de Liçana i d’Alagó, who took up residence in Valencia and serve to three kings in the «Crown of Aragon », Martín I El Humano, Fernando I El de Antequera and Alfonso V El Magnánimo, been as Councilor and Majordomo of the two last ones. He was a man-at-arms, a career soldier from the 15th century, expert in guerrilla war, who was practice at an early stage in the noble armed struggle, a real plague at Valencia in the 15th century

Anthropometric Characteristics, Body Composition and Somatotype of Elite Pan-American Race Walking 20K

The anthropometric and somatotype evaluation is an essential tool in the selection and control of high-performance athletes. The aim of this study was to describe the somatotype and body composition of male elite race walkers (20 k modality), and its relationship with athletic performance. Twenty-four race walkers participated in this study. The sample was divided into two groups: the race walkers with the best performance (upper 25 percentile; n=7) and the second group (n=17) that corresponds to the rest of the participants. Weight (kg), height (cm), seven skinfolds, two diameters and five perimeters were measured. Body fat percentage (BF%) were estimated with the Yuhasz formula, and the somatotype was used applying the Heath-Carter method. The best performing athletes were taller (178.3 +/- 4.4 cm vs. 173.7 +/- 5.6 cm, p<0.05) and showed a greater ectomorphic component (p<0.05) than the rest of the participants. The somatotype of the best performance athletes was 2.2-2.8-4.1 against the 2.5-3.8-2.9 of the lowest performing athletes. The average time (hours, minute, seconds) of execution of the race in athletes of better performances was 1: 22:40, in comparison with the athletes of lower performances with 1: 32: 41 (p<0.02). The ectomorphic component and height are morphological characteristics that can determine athletic performance of race walkers. It is suggested to consider these factors in the selection of the race walkers. La evaluación antropométrica y del somatotipo es una importante herramienta en la selección y control de los atletas de alto rendimiento. El objetivo de este estudio fue describir el somatotipo y composición corporal de hombres marchistas olímpicos, modalidad 20 k, y su relación con el rendimiento atlético. Veinticuatro atletas de marcha participaron en este estudio. La muestra fue dividida en dos grupos: los marchistas de mejores rendimientos p25 superior (n=7) y el segundo grupo (n=17) que corresponde al resto de los participantes. Se registró el peso (kg), talla (cm), siete pliegues cutáneos, dos diámetros y cinco perímetros. Se estimó el porcentaje de grasa corporal (%GC) con la fórmula de Yuhasz y se describió el somatotipo utilizando el método de Heath-Carter. Se reporta una mayor altura en los atletas de mejor rendimiento (178,3±4,4 cm vs. 173,7±5,6 cm; p<0,05) y mayor componente ectomorfico (p<0,05) que el resto de los participantes. El somatotipo de los atletas de mejor rendimiento fue de 2.2-2.8-4.1 frente al 2.5-3.8-2.9 de los atletas de menor rendimiento. El tiempo promedio (hora, minuto, segundo) de ejecución de la carrera en atletas de mejores rendimientos fue de 1:22:40, en comparación con los atletas de menores rendimientos con 1:32:41 (p <0,02). El componente ectomórfico y altura serian características morfológicas que pueden determinar el rendimiento deportivo de atletas de marcha. Se sugiere considerar estos factores en la selección de los marchistas olímpicos

Assessment of Spray Deposit and Loss in Traditional and Intensive Olive Orchards with Conventional and Crop-Adapted Sprayers

Plant protection product (PPP) applications to isolated olive trees are commonly performed with regular air-assisted sprayers, which are not adapted to their particular characteristics. Whilst strong efforts have been undertaken over the last years to improve technical aspects like canopy detection and automated proportional dosing, nearly no efforts have been made regarding the sprayer adaption to the crop. For this reason, three prototype sprayers were developed for traditional and intensive olive cultivations systems (P1: centrifugal fan; P2: six small side axial fans; P3: two axial fans in tower structure) with the purpose to improve the application efficiency. The main goal of the present study was to check spray quality and efficiency in comparison with the conventional sprayer in both cultivation systems. The sprayers were tested in two different olive groves and properly calibrated according to the tree dimensions. The spray deposition, coverage, drift, and losses to the ground were measured in five trees per cultivation system by placing the appropriate collectors. The sprayers performed very differently in both cultivation systems. In the intensive system, the spray deposition did not present significant differences (p = 0.105). However, it did in the traditional system (p = 0.003), with P3 obtaining the best results. The spray coverage followed the same trend, with significant differences only in the traditional orchard (p = 0.011), with the prototypes leading. The conventional equipment generated the highest spray losses in both cultivation systems. Crop adapted spraying can significantly improve the spray quality and efficiency in difficult crops like olive. This topic may have a key importance to match the environmentally sustainable use of PPP

RESISTENCIA ANTIBIÓTICA DE SALMONELLA SPP, ESCHERICHIA COLI AISLADAS DE ALPACAS (Vicugna pacus) CON Y SIN DIARREA

A nivel mundial, el problema de resistencia a antibióticos es considerado de prioridad sanitaria pública y veterinaria, por ello el objetivo de esta investigación fue evaluar la presencia de resistencia antibiótica frente a Salmonella sp., y Escherichia coli provenientes de crías de alpacas con y sin diarrea. La investigación fue de tipo descriptivo transversal múltiple. Se recolectaron 300 muestras de heces por hisopado rectal de crías de alpacas entre 10 a 60 días nacidas con y sin cuadros diarreicos provenientes de Comunidades Campesinas de Huancavelica-Perú. La presencia de Escherichia coli y Salmonella spp. Se identificó mediante pruebas bioquímicas la susceptibilidad antibacteriana por método Kirby Bauer y se evaluaron 8 antibióticos usuales del mercado veterinaria. El 100%de muestras con diarreas fueron positivas a Escherichia coli, 40,0%Salmonella spp., 20%Escherichia coli-Salmonella spp. y muestras sin diarrea 57,0%positivas a Escherichia coli, 24,0% Salmonella spp., 19.0% E. coli-Salmonella spp. Las cepas de Escherichia coli y Salmonella spp. fueron resistentes a Ampicilina (10,4 0,3), (9,3 0,2); Novomicina (11,1 0,2), (11,2 0,1); Tetraciclina (8,2 0,1), (9,2 0,3); Penicilina (9,1 0,4), (11,1 0,3); Gentamicina (10,1 0,4), (10,2 0,3) provenientes de muestras con diarrea y en muestras sin diarrea resistentes a Gentamicina (10,3 0,1), (8,2 0,1); Tetraciclina (9,2 0,4), (8,2 0,4); Ampicilina (11,2 0,1), (9,3 0,2); Penicilina (10,2 0,4), (10,1 0,3). Las cepas de Salmonella spp., y Escherichia coli aisladas de crías de alpacas con y sin diarreas evidencian resistencia antibacteriana a múltiples antibióticos usados en la veterinaria//The problem of antibiotic resistance is considered a public and veterinary sanitary priority worldwide, for that reason the aim of the study was to evaluate the presence of antibiotic resistance against Salmonella spp., Escherichia coli coming from alpaca calves with and without diarrhea. The research was cross-sectional descriptive. 300 stool samples per rectal swab were collected from alpaca calves aging from 10 and 60 days with and without diarrhea from Peasant Communities in Huancavelica – Peru. The presence of Escherichia coli and Salmonella spp. was identified by conventional biochemical test, antibacterial susceptibility by Kirby Bauer method and 8 usual antibiotics from the veterinary market were evaluated. 100% of samples with diarrhea were positive to Escherichia coli; 40.0% Salmonella spp.; 40% Escherichia coli -Salmonella spp., and samples without diarrhea 48.3% positive to Escherichia Coli; 14.0% Salmonella spp.; 9.3% Escherichia coli -Salmonella spp. The CMI in Escherichia coli and Salmonella spp. strains were resistant to Ampicillin (10.4 0.3), (9.3 0.2); Novomycin (11.1 0.2), (11.2 0. 1); Tetracycline (8.2 0.1), (9.2 0.3); Penicillin (9.1 0. 4), (11.1 0. 3); Gentamicin (10.1 0. 4), (10.2 0. 3) from samples with diarrhea and in samples without diarrhea resistant to Gentamicin (10.3 0.1), (8.2 0.1); Tetracycline (9.2 0.4), (8.2 0.4); Ampicillin (11.2 0.1), (9.3 0.2); Penicillin (10.2 0.4), (10.1 0.3). Salmonella spp., Escherichia coli strains isolated from alpaca calves with and without diarrhea show antibacterial resistance to multiple antibiotics used in veterinary

Compact LCOS–SLM Based Polarization Pattern Beam Generator

In this paper, a compact optical system for generating arbitrary spatial light polarization patterns is demonstrated. The system uses a single high-resolution liquid crystal (LC) on silicon (LCOS) spatial light modulator. A specialized optical mount is designed and fabricated using a 3D printer, in order to build a compact dual optical architecture, where two different phase patterns are encoded on two adjacent halves of the LCOS screen, with a polarization transformation in between. The final polarization state is controlled via two rotations of the Poincaré sphere. In addition, a relative phase term is added, which is calculated based on spherical trigonometry on the Poincaré sphere. Experimental results are presented that show the effectiveness of the system to produce polarization patterns