Las redes inalámbricas de área local ("Wi-Fi") en la FCC y el CNAF

En los últimos años, las Redes Inalámbricas de Área Local (WLAN, Wireless Local Área Networks) basadas en el estándar IEEE (802.11 [1] y sus derivados ñan conseguido unos altos niveles de implantación y desbordar el ámbito de aplicaciones y servicios para los que fueron inicialmente concebidas. De hecho, que se ñan convertido en un fenómeno tecnológico

Despliegue de redes inalámbricas (WI-FI): planificación radio

Desde hace apenas tres años, una tecnología, o quizás sería más exacto, un protocolo de comunicaciones empezó a despuntar con éxito y vistas de un tremendo futuro. Esta tecnología basada en el estándar IEEE 802.11b y conocida como Wi-Fi (“Wireless Fidelity”) ha conseguido unos altos niveles de implantación, desbordar el ámbito de aplicaciones y servicios para los que fue inicialmente concebida y ser un poderoso complemento a otras tecnologías que requieren importantes infraestructuras y altos niveles de inversión

Hipotiroidismo subclínico y factores de riesgo cardiovascular

Objetivo: Conocer la prevalencia del hipotiroidismo subclínico en la población general de un centro de salud urbano y describir las características clínicas y factores de riesgo cardiovascular de los pacientes con hipotiroidismo subclínico. Métodos: Se realizó un estudio observacional descriptivo, transversal, retrospectivo, revisando las historias clínicas de los pacientes incluidos en la muestra desde junio de 2005 hasta julio de 2007. Se analizaron las siguientes variables; Datos generales: edad y sexo. Antecedentes familiares: patología tiroidea y otras enfermedades. Antecedentes personales: cardiovasculares, pulmonares, enfermedades autoinmunes, alteraciones gineco-obstétricas, diabetes, hipertensión (HT), dislipemia, obesidad, alteraciones psiquiátricas y hematológicas. Datos de laboratorio: niveles de TSH, niveles de T4 libre,presencia de anticuerpos antiperoxidasa, niveles de colesterol total y sus fracciones. Resultados: La prevalencia de la muestra de 100 pacientes recogida durante 8 meses fue de 3,8% de la población general mayor de 14 años, de la cual 79 eran mujeres y 21 eran hombres. El 13% eran diabéticos tipo 2, 23% tenían HT y un 40% tenían dislipemia. Sobrepeso y obesidad estaban presentes en un 26%. El nivel medio de TSH fue 6.92 ± 2,29 U/ml y el nivel medio de T4 libre fue 1,16 ± 0,16 ng/ml. Conclusiones: La prevalencia del hipotiroidismo subclínico fue 3,8%. sobre todo en mujeres con una edad media de 46 años. La incidencia de factores de riesgo cardiovascular en los sujetos estudiados es mayor en DM (13%), similar a la población general en cuanto a la dislipemia (40%) y obesidad (20%) y menor en HTA (23%). En nuestro estudio no se observa una pauta común en el manejo del hipotiroidismo subclínico, siendo necesaria la implementación y promoción de guías de actuación en Atención PrimariaObjective: To determine the prevalence of subclinical hypothyroidism in the general population of an urban health center and describe the clinical characteristics and cardiovascular risk factors in patients with subclinical hypothyroidism. Methods: An observational study, retrospective, reviewing the medical histories of patients sampled from June 2005 until July 2007. We analyzed the following variables; facts: age and sex. Family history thyroid disease and other diseases. Personal history: cardiovascular pulmonary autoimmune, alterations gynecology obstetric diabetes, hypertension (HT) dislipemia, obesity, psychiatric alterations and haematological. Laboratory data: novel TSH, free T4, antiperoxidase antibodies, total cholesterol and its fractions. Results: The prevalence of the sample of 100 patients collected over 8 months was 3.8% in the general population over 14 years, of which 79 were women and 21 were men. 13% were type 2 diabetics, 23% had HT and 40% had dyslipidemia. Overweight and obesity were present in 26%. The average level of TSH was 6.92 ± 2.29 U/ml and the average level of free T4 was 1.16 ± 0.16 ng/ml. Conclusions: Prevalence subclinical hypothyroidism was 3.8%. especially in women with a mean age of 46. The incidence of cardiovascular risk factors in the subjects studied is higher in DM (13%), similar to general population in terms of dyslipidemia (40%) and obesity (23%) and lowest in hypertension (23%). In our study we observed a common pattern in the management of subclinical hypothyroidism, requiring the implementation and promotion of practice guidelines in primary car

Estudio de algunos elementos minerales presentes en diversos Cestodes

Se han estudiado en Dipylidium canium (hospedador Canis familiaris), Avitellina caninum centripunctata (hospedador Ovis aries), Moniezia expansa (hospedador Ovis aries), Moniezia benedeni (hospedador Bos taurus), Taenia saginata (hospedador Homo sapiens) y Neotaenotenia ctenoides (hospedador Oryctolagus cuniculus), los siguientes elementos minerales: Ca, Mg, Na y K.In this paper the authors hav·e studied in Dipylidium caninum (host Canís familiaris), Avitellina centripunctata (host Ovis aries), Moniezia expansa (host Ovies aries), Moniezia benedeni (host Bos taurus), Taenia saginata (host Hamo sapines) and Neotaenotenia ctenoides (host Oryctolagus cuniculus), the fOllowing elements minerals; Ca, M g, Na and K

The role of conductive additives on the performance of hybrid carbon xerogels as electrodes in aqueous supercapacitors

Three different hybrid carbon xerogels containing Graphene Oxide (AXGO), Micronized Graphite (AXMG) and Carbon Black (AXCB) were synthesized using an easy, fast and affordable method. These three additives were initially selected to improve the electrical conductivity of the pristine activated carbon xerogel (AX) thus expecting to improve its performance in aqueous supercapacitors. Capacitances of the corresponding devices were measured as a function of current density and results of the high and low charge transfer regime of the supercapacitors were discussed separately. In both regimes, the differences observed between the hybrid electrodes were analyzed on the basis of the concurrent influence of the micro and mesoporosity, surface chemistry and electrical conductivity of the materials. Accordingly, even though all the hybrid carbon xerogels showed higher electrical conductivities, only AXGO rendered a better performance than AX, showing the highest capacitances in the whole interval of intensities studied. Consequently, at 16 A g−1, the energy and power densities of the AXGO supercapacitors increased up to 16% and 97%, respectively, with respect to AX, and of 143% and 409%, respectively, with respect to a commercial activated carbon used as reference. The performance of AXCB and, especially AXMG was worse than AX supercapacitors due to a combination of inadequate pore size distributions and/or a poor surface chemistry. Finally, TEM analysis helped to understand the different way the three additives were affecting the nanostructure (and final properties) of the hybrid carbon xerogels.Authors gratefully acknowledge the financial support from the Ministerio de Economía, Industria y Competitividad from Spain (Project CTQ2017-87820-R). MCR also acknowledges CSIC (Project I.E. 201880E010)

Norm-attaining weighted composition operators on weighted Banach spaces of analytic functions

The final publication is available at Springer via http://dx.doi.org/10.1007/s00013-012-0458-zWe investigate weighted composition operators that attain their norm on weighted Banach spaces of holomorphic functions on the unit disc of type H∞. Applications for composition operators on weighted Bloch spaces are given. © 2012 Springer Basel.1. The authors are thankful to the referee for pointing to us the references [15] and [16] and their relevance in the present research. 2. The research of Bonet was partially supported by MICINN and FEDER Project MTM2010-15200 and by GV project Prometeo/2008/101 and project ACOMP/2012/090.Bonet Solves, JA.; Lindström, M.; Wolf, E. (2012). Norm-attaining weighted composition operators on weighted Banach spaces of analytic functions. Archiv der Mathematik. 99(6):537-546. https://doi.org/10.1007/s00013-012-0458-zS537546996Bierstedt K.D., Bonet J., Galbis A.: Weighted spaces of holomorphic functions on bounded domains. Michigan Math. J. 40, 271–297 (1993)Bierstedt K.D., Bonet J., Taskinen J.: Associated weights and spaces of holomorphic functions. Studia Math. 127, 137–168 (1998)J. Bonet, P. Domański, and M. Lindström, Essential norm and weak compactness of composition operators on weighted Banach spaces of analytic functions. Canad, Math. Bull. 42, no. 2, (1999), 139–148Bonet J. et al.: Composition operators between weighted Banach spaces of analytic functions. J. Austral. Math. Soc. Ser. A 64, 101–118 (1998)Bonet J., Lindström M, Wolf E.: Isometric weighted composition operators on weighted Banach spaces of type H ∞. Proc. Amer. Math. Soc. 136, 4267–4273 (2008)Bonet J, Wolf E.: A note on weighted spaces of holomorphic functions. Archiv Math. 81, 650–654 (2003)Contreras M.D, Hernández-Díaz A.G.: Weighted composition operators in weighted banach spaces of analytic functions. J. Austral. Math. Soc. Ser. A 69, 41–60 (2000)Cowen C., MacCluer B.: Composition Operators on Spaces of Analytic Functions. CRC Press, Boca Raton (1995)J. Diestel, Geometry of Banach Spaces. Selected Topics, Lecture Notes in Math. vol. 485, Springer, Berlin, 1975.Hammond C.: On the norm of a composition operator with linear fractional symbol. Acta Sci. Math. (Szeged) 69, 813–829 (2003)Hosokawa T., Izuchi K., Zheng D.: Isolated points and essential components of composition operators on H ∞. Proc. Amer. Math. Soc. 130, 1765–1773 (2001)Hosokava T., Ohno S.: Topological strusctures of the sets of composition operatorson the Bloch spaces. J. Math. anal. Appl. 303, 499–508 (2005)Lusky W.: On the isomorphy classes of weighted spaces of harmonic and holomorphic functions. Studia Math. 175, 19–45 (2006)Martín M.: Norm-attaining composition operators on the Bloch spaces. J. Math. Anal. Appl. 369, 15–21 (2010)A. Montes-Rodríguez, The Pick-Schwarz lemma and composition operators on Bloch spaces, International Workshop on Operator Theory (Cefalu, 1997), Rend. Circ. Mat. Palermo (2) Suppl. 56 (1998), 167–170.Montes-Rodríguez A.: The essential norm of a composition operator on Bloch spaces. Pacific J. Math. 188, 339–351 (1999)Montes-Rodríguez A.: Weighted composition operators on weighted Banach spaces of analytic functions. J. London Math. Soc. 61, 872–884 (2000)J.H. Shapiro, Composition Operators and Classical Function Theory, Springer, 1993.K. Zhu, Operator Theory in Function Spaces, Second Edition. Amer. Math. Soc., 2007

Risk factors against bovine respiratory diseade in suckling calves from Argentina

An observacional cross-sectional study was performed to determine the risk factors associated to the main viral agents of the bovine respiratory disease: bovine herpesvirus type 1 (HVB1), bovine viral diarrhoea virus (VDVB), bovine respiratory syncytial virus (VRSB) and parainfluenza 3 virus (VPI3). Blood samples from dairy calves in the provinces of Cordova and Santa Fe (Argentina) were obtained, and an epidemiological ques-tionnaire was filled. Antibodies against studied viruses were detected by commercial ELISA kits. A total of 852 blood samples from 55 dairy operations were obtained between years 2000 and 2002. Four epidemiologic logistic regression models were performed. We found significant associations between infection and variables related to the age of the calf, the season, the size population, the vaccinations, the feeding or the breeding system, among many others.Se ha realizado un estudio epidemiológico observacional de tipo transversal para conocer los factores que actúan sobre la seropositividad de los principales agentes víricos del síndrome respiratorio bovino: el herpesvirus bovino tipo 1 (HVB1), el virus de la diarrea vírica bovina (VDVB), el virus respiratorio sincitial bovino (VRSB) y el virus de la parainfluenza 3 (VPI3). Se tomaron muestras de sangre de terneros procedentes de explotaciones lecheras situadas en las provincias argentinas de Córdoba y Santa Fé, y se cumplimentaron cuestionarios epide-miológicos. Los análisis serológicos se realizaron mediante la técnica ELISA. En total se tomaron muestras de sangre de 852 terneros procedentes de 55 explotaciones entre los años 2000 y 2002. Se realizaron cuatro modelos epidemiológicos mediante regresión logística, uno por cada virus donde, entre otras, aparecen variables asociadas a la infección relacionadas con la edad del ternero, la estación del año, el número de animales, la alimentación, las vacunaciones o el sistema de crianza

Notas para la interpretación de la utilidad de los análisis para hongos fitopatógenos en suelos y sustratos para usos agrícolas

Interpretación de la utilidad de los análisis para hongos fitopatógenos en suelos y sustratos para usos agrícola