Photonic heterostructures with Levy-type disorder: statistics of coherent transmission

We study the electromagnetic transmission $T$ through one-dimensional (1D) photonic heterostructures whose random layer thicknesses follow a long-tailed distribution --L\'evy-type distribution. Based on recent predictions made for 1D coherent transport with L\'evy-type disorder, we show numerically that for a system of length $L$ (i) the average $\propto L^\alpha$ for $0 \propto L$ for $1\le\alpha<2$, $\alpha$ being the exponent of the power-law decay of the layer-thickness probability distribution; and (ii) the transmission distribution $P(T)$ is independent of the angle of incidence and frequency of the electromagnetic wave, but it is fully determined by the values of $\alpha$ and $$.Comment: 4 pages, 4 figure

Prevalencia de insuficiencia renal «oculta» en población diabética tipo 2

ObjetivoDeterminar la prevalencia de insuficiencia renal en diabéticos tipo 2 y comparar dos criterios de definición: el basado en la estimación del filtrado glomerular por la fórmula de Cockcroft-Gault corregida para la superficie corporal y el basado en la creatinina sérica.DiseñoEstudio descriptivo y transversal.EmplazamientoZona básica del Centro de Salud de El Cristo, Oviedo.ParticipantesLa totalidad de pacientes diabéticos tipo 2 diagnosticados de la zona básica.Mediciones principalesSe recogieron datos demográficos, clínicos, factores de riesgo y enfermedad cardiovascular. Se diagnosticó insuficiencia renal (IR) según unas cifras de creatinina plasmática ≥ 1,3 mg/dl en mujeres y ≥ 1,4 mg/dl en varones y según el filtrado glomerular (FG) estimado mediante la fórmula de Cockcroft-Gault: moderada para FG, 60-30 ml/min/1,73 m2; grave para FG, 29-15 ml/min/1,73 m2, y terminal para FG, < 15 ml/min/1,73 m2.ResultadosSe incluyó a 499 pacientes. El 52,3% era mujer con una edad de 69,7 ± 0,4 años. La prevalencia de IR según la creatinina sérica fue del 12%, y según la fórmula de Cockcroft-Gault del 40,5%. Los pacientes con FG reducido y creatinina normal tenían mayor edad (75,5 ± 7,9 frente a 65,4 ± 9,8 años; p < 0,001), predominaban las mujeres (76,3 frente a 41,7%; p < 0,001), tenían un menor índice de masa corporal (27,3 ± 3,7 frente a 30,9 ± 4,4), presentaban un peor control glucémico (HbA1c 7,1 ± 1,8 frente a 6,9 ± 1,9%; p = 0,007) y la prevalencia de insuficiencia cardíaca era superior (6,4 frente a 2,1%; IC del 95%, 1,1-8,8; p = 0,02) en comparación con los pacientes con FG y creatinina normales.ConclusiónLa estimación del FG por la fórmula de Cockcroft-Gault corregida para la superficie corporal muestra una insuficiencia renal no conocida en uno de cada 3 pacientes diabéticos tipo 2.ObjectiveTo determine the prevalence of renal failure (RF) in type-2 diabetics and to compare two criteria of definition: that based on the calculation of glomerular filtration by the Cockcroft-Gault formula corrected for body surface area and that based on serous creatinine.DesignCross-sectional, descriptive study.SettingEl Cristo Health Centre,Oviedo, north of Spain.ParticipantsAll patients in the catchment area diagnosed with type-2 diabetes.MethodDemographic, clinical, risk factor, and cardiovascular pathology details were gathered. Renal failure was diagnosed on figures of plasma creatinine ≥1.3 mg/dL in women and ≥1.4 mg/dL in men, and glomerular filtration (GF) calculated by means of the Cockcroft-Gault formula: moderate GF, 60-30 mL/min/1.73 m2; severe GF, 29-15 mL/min/1.73 m2, and terminal GF: <15 mL/min/1.73 m2.Results499 patients were included. 52.3% were women, aged 69.7±10.4 years old. Prevalence of RF by serous creatinine was 12%; and by the Cockcroft-Gault formula, 40.5%. Patients with lower glomerular filtration and normal creatinine were older (75.5±7.9 vs 65.4±9.8; P<.001), mainly female (76.3% vs 41.7%; P<.001), had lower BMI (27.3±3.7 vs 30.9±4.4) and had worse glucaemia control (HbA1c 7.1±1.8% vs 6.9±1.9%; P=.007) and higher indices of cardiac failure (6.4% vs 2.1%; 95% CI, 1.1- 8.8; P=.02) than patients with normal glomerular filtration and creatinine.ConclusionCalculation of glomerular filtration by the Cockcroft-Gault formula corrected for body surface area revealed unknown renal failure in 1 in 3 type-2 diabetes patients

Delay time of waves performing Levy walks in 1D random media

[EN] The time that waves spend inside 1D random media with the possibility of performing Lévy walks is experimentally and theoretically studied. The dynamics of quantum and classical wave diffusion has been investigated in canonical disordered systems via the delay time. We show that a wide class of disorder¿Lévy disorder¿leads to strong random fluctuations of the delay time; nevertheless, some statistical properties such as the tail of the distribution and the average of the delay time are insensitive to Lévy walks. Our results reveal a universal character of wave propagation that goes beyond standard Brownian wave-diffusion.A. A. F.-M. thanks the hospitality of the Laboratoire d'Acoustique de l'Universite du Mans, France, where part of this work was done. J. A. M.-B, gratefully acknowledges to Departamento de Matematica Aplicada e Estatistica, Instituto de Ciencias Matematicas e de Computacao, Universidade de Sao Paulo during which this work was completed. J.A.M.-B. was supported by FAPESP (Grant No. 2019/06931-2), Brazil. A. A. F.-M. thanks partial support by RFI Le Mans Acoustique and by the project HYPERMETA funded under the program Etoiles Montantes of the Region Pays de la Loire. V. A. G. acknowledges support by MCIU (Spain) under the Project number PGC2018-094684-B-C22.Razo-López, LA.; Fernández-Marín, AA.; Mendez-Bermudez, JA.; Sánchez-Dehesa Moreno-Cid, J.; Gopar, VA. (2020). Delay time of waves performing Levy walks in 1D random media. Scientific Reports. 10(1):1-8. https://doi.org/10.1038/s41598-020-77861-xS18101Wigner, E. P. Lower limit for the energy derivative of the scattering phase shift. Phys. Rev. 147, 145–147 (1955).Smith, F. T. Lifetime matrix in collision theory. Phys. Rev. 119, 2098–2098 (1960).Fercher, A. F., Drexler, W., Hitzenberger, C. K. & Lasser, T. Optical coherence tomography -principles and applications. Rep. Prog. Phys. 66, 239–303 (2003).Lubatsch, A. & Frank, R. 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Caractérisation des systèmes de production ovine dans la zone de "Sierra del Segura y la Sagra", Espagne

[FR] Le présent article se propose d¿analyser les caractéristiques les plus saillantes du secteur ovin dans une partie de la zone géographique sous Indication Géographique Protégée (IGP) "Cordero de Segura y la Sagra". Une enquête a été menée sur 93 propriétaires d¿élevages, dans l'objectif de connaître la situation du secteur dans cette zone. Les questions concernaient les sujets suivants: caractéristiques du troupeau, âge, niveau d'études, ouvriers à la ferme, continuité des activités de la ferme. La taille moyenne du troupeau est de 378 animaux et la race "Segureña" est prédominante (99%). Dans 93,4% des cas l¿éleveur travaille à temps plein dans l¿exploitation et le revenu principal est la vente d¿agneaux pour la viande, mais seulement 9,7% des éleveurs font partie d¿une coopérative pour la commercialisation. L'âge moyen du fermier est de 50 ans et 87,1% des éleveurs n¿ont pas d¿études ou de faible niveau. La moyenne du travail employé est de 1,31 UTA, essentiellement de type familial. Seulement dans 12% des cas il existe une sécurité de la continuité de l'activité. Les résultats obtenus montrent qu'il est nécessaire de parvenir à de meilleures conditions socioéconomiques pour les exploitations dans la zone étudiée. L'IGP "Cordero de Segura y la Sagra" pourrait être utile pour améliorer ces aspects.[EN] The aim of this study is to present the basic characteristics which define the sheep systems in some zones of the PGI Cordero de Segura y la Sagra protected area, in order to bring about actions to improve the competitiveness of such systems. A survey has been conducted among 93 farm owners. The questionnaire included questions regarding herd characteristics, age, educational level, workers, and continuity of the farm activity. The average herd size is 378 animals and the Segureña breed sheep is predominant (99 percent). In 93.5 percent of cases the owner works full time on the farm and the main economic benefit is the sale of lambs for meat, but only 9.7 percent of farmers belong to some kind of marketing cooperative. The average farmer's age is 50 years old and a high percentage (87.1 percent) has no education or a very basic one. The year work unit (YWU) is 1.31 and the work is mainly of family type. In only 12 percent of the cases the continuity of the activity is assured. The above analysed aspects show that it is necessary to achieve better socioeconomic conditions of farms. The PGI Cordero de Segura y la Sagra could be useful to improve these aspects. Therefore we suggest that the PGI must be promoted among farmers, especially among young people.Navarro-Ríos, M.; Marín-Bernal, A.; Martí, A.; Fernández Martínez, CJ. (2011). Characterizacion of Segureña sheep production system in the area of Sierra del Segura y la Sagra, Spain. Options Mediterraneennes. Serie A: Seminaires Mediterraneens. (100):211-216. http://hdl.handle.net/10251/107315S21121610

Field analysis of the deterioration after some years of use of four insect-proof screens utilized in Mediterranean greenhouses

The installation of insect-proof screens on greenhouse vents is one of the principal methods of protection against harmful insects for crops. Their main disadvantage lies on their negative effects on natural ventilation and greenhouse microclimate, which have been the focus of studies by several authors. However, few works have analysed the effect of accumulated dust and dirt on these screens. The present study has analysed four anti-insect screens, comparing their geometric characteristics before installation and after three to four years of use. Two negative effects have been observed and quantified: deterioration of the threads that make up the screen and reduction of porosity due to accumulated dirt in the pores. This deterioration over time gives leads to a mean increase in thread diameter of 3.1%, as well to a mean decrease in the pore size of 6.2% and 2.3% in the weft (Lpx) and the warp (Lpy), respectively. In fact, the insect-proof screen porosity (φ) decreased due to the deterioration of the threads by an average of 6.5%, in addition to an average 20.3% reduction due to the accumulation of dirt in the pores, making a total reduction in porosity of 26.8%. This decrease in porosity leads to lower greenhouse ventilation rates, and is therefore detrimental for the greenhouse microclimate. Consequently, it is recommended that insect-proof screens in arid areas such as Almería (Spain), with abundant dust suspended in the atmosphere, be washed monthly using water sprayed at high pressure

Manufacture of Carbon Materials with High Nitrogen Content

Nowadays one of the biggest challenges for carbon materials is their use in CO2 capture and their use as electrocatalysts in the oxygen reduction reaction (ORR). In both cases, it is necessary to dope the carbon with nitrogen species. Conventional methods to prepare nitrogen doped carbons such as melamine carbonization or NH3 treatment generate nitrogen doped carbons with insufficient nitrogen content. In the present research, a series of activated carbons derived from MOFs (ZIF-8, ZIF-67) are presented. Activated carbons have been prepared in a single step, by pyrolysis of the MOF in an inert atmosphere, between 600 and 1000 °C. The carbons have a nitrogen content up to 20 at.% and a surface area up to 1000 m2/g. The presence of this nitrogen as pyridine or pyrrolic groups, and as quaternary nitrogen are responsible for the great adsorption capacity of CO2, especially the first two. The presence of Zn and Co generates very different carbonaceous structures. Zn generates a greater porosity development, which makes the doped carbons ideal for CO2 capture. Co generates more graphitized doped carbons, which make them suitable for their use in electrochemistry.Authors acknowledge financial support by MINECO (Spain) through the project MAT2017-86992-R and “Ministerio de Ciencia e Innovación” (PID2020-116998RB-I00)

Fístula arteriovenosa postraumática: tratamiento endovascular. Revisión de la literatura y presentación de un caso clínico

ResumenLas fístulas arteriovenosas en la cabeza y el cuello son entidades poco frecuentes. La mayoría es secundaria a heridas penetrantes por arma blanca. Se describe el tratamiento exitoso mediante cirugía endovascular de una fístula postraumática tras una herida penetrante entre la arteria maxilar interna izquierda y la vena yugular externa. A través de este caso clínico y la revisión de la literatura se ilustran las causas, manifestaciones, estudio radiológico y tratamiento de una fístula postraumática entre la arteria maxilar interna y la vena yugular externa. A través de este caso clínico se demuestra la utilidad de los procedimientos endovasculares en el tratamiento de estas complicaciones.AbstractTraumatic arteriovenous fistulas of the head and neck region are uncommon. The majority are due to penetration of blunt injury. We describe a successful endovascular treatment of a posttraumatic fistula between the left maxillary artery and the external jugular vein due to a penetration injury. This case and a review of the literature illustrate the causes, manifestations, image studies and treatment for a posttraumatic fistula between the maxillary artery and the external jugular vein. This case demonstrate the utility of endovascular treatment of head and neck injuries complications