General results on the convergence of multipoint Hermite-Padé approximants of Nikishin systems

19 pages, no figures.-- MSC1991 codes: Primary 30E10, 42C05.MR#: MR2263738 (2007g:42041)Zbl#: Zbl 1105.30024We consider simultaneous approximation of Nikishin systems of functions by means of rational vector functions which are constructed interpolating along a prescribed table of points. We give general conditions for the uniform convergence of such approximants with a geometric rate under very weak assumptions.The work of both authors was supported by Ministerio de Ciencia y Tecnología under grant BFM 2003-06335-C03-02. The second author was also partially supported by NATO PST.CLG.979738 and INTAS 03-51-6637.Publicad

Generalized Hermite-Padé approximation for Nikishin systems of three functions

9 pages, no figures.-- MSC1991 code: Primary 42C05.-- Issue title: "Special Functions, Information Theory, and Mathematical Physics". Special issue dedicated to Professor Jesús Sánchez Dehesa on the occasion of his 60th birthday.Zbl#: Zbl pre05650072Nikishin systems of three functions are considered. For such systems, the rate of convergence of simultaneous interpolating rational approximations with partially prescribed poles is studied. The solution is described in terms of the solution of a vector equilibrium problem in the presence of a vector external field.First author’s research supported by grants MTM 2006-13000-C03-02 from Ministerio de Ciencia y Tecnología and CCG 06–UC3M/ESP–0690 of Universidad Carlos III de Madrid-Comunidad de Madrid and by grant SFRH/BPD/31724/2006 from Fundação para a Ciência e a Tecnologia. Second author’s research supported by grants MTM 2006-13000-C03-02 from Ministerio de Ciencia y Tecnología and CCG 06–UC3M/ESP–0690 of Universidad Carlos III de Madrid-Comunidad de Madrid.Publicad

Rate of convergence of generalized Hermite-Padé approximants of Nikishin systems

32 pages, no figures.-- MSC1991 code: Primary, 42CD5.MR#: MR2186304 (2006h:41017)Zbl#: Zbl 1136.42306We study the rate of convergence of interpolating simultaneous rational approximations with partially prescribed poles to so-called Nikishin systems of functions. To this end, a vector equilibrium problem in the presence of a vector external field is solved which is used to describe the asymptotic behavior of the corresponding second-type functions which appear.The work of both authors was supported by the Ministerio de Ciencia y Tecnología under grant BFM 2003-06335-C03-02. The second author was also partially supported by NATO PST.CLG.979738 and INTAS 03-51-6637.Publicad

On perfect Nikishin systems

12 pages, no figures.-- MSC1991 code: Primary 42C05.-- Publisher's full-text version available Open Access at: http://www.heldermann-verlag.de/cmf/cmf02/cmf0224.pdfMR#: MR2038130 (2005c:42026)Zbl#: Zbl 1065.42020We prove perfectness for Nikishin systems made up of three functions and apply this to the convergence of the associated Hermite-Padé approximant.The work of both authors was partially supported by Dirección General de Enseñanza Superior under grant BFM2000-0206-C04-01 and the second author by grants PRAXIS XXI BCC-22201/99 and INTAS 00-272.Publicad

Convergence and computation of simultaneous rational quadrature formulas

22 pages, no figures.-- MSC2000 codes: Primary 41A55. Secondary 41A28, 65D32.MR#: MR2286008 (2008a:65049)Zbl#: Zbl 1168.65326We discuss the convergence and numerical evaluation of simultaneous quadrature formulas which are exact for rational functions. The problem consists in integrating a single function with respect to different measures using a common set of quadrature nodes. Given a multi-index n, the nodes of the integration rule are the zeros of the multi-orthogonal Hermite–Padé polynomial with respect to (S, α, n), where S is a collection of measures, and α is a polynomial which modifies the measures in S. The theory is based on the connection between Gauss-type simultaneous quadrature formulas of rational type and multipoint Hermite–Padé approximation. The numerical treatment relies on the technique of modifying the integrand by means of a change of variable when it has real poles close to the integration interval. The output of some tests show the power of this approach in comparison with other ones in use.The work of U.F.P. and G.L.L. was partially supported by Dirección General de Enseñanza Superior under grant BFM2003-06335-C03-02 and of G.L.L. by INTAS under Grant INTAS 03-51-6637. The work of J.R.I. was supported by a research grant from the Ministerio de Educación y Ciencia, project code MTM 2005-01320.Publicad

Optimal designs for compartmental models with correlated observations

El objetivo del estudio es proveer óptimos tiempos para realizar bioensayos cuando ha habido una entrada accidental de radioactividad.The flow of internally deposited radioisotope particles inside the body of people exposed to inhalation, ingestion, injection or other ways is usually evaluated using compartmental models (see Sánchez and López-Fidalgo, (2003, and López-Fidalgo and Sánchez, 2005). The International Commission on Radiological Protection (ICRP, 1994) describes the model of the human respiratory tract, represented by two main regions. One of these, the thoracic region (lungs) is divided into different compartments. The retention in the lungs is given by a large combination of ratios of exponential sums depending on time. The aim of this work is to provide optimal times for making bioassays when there has been an accidental radioactivity intake and there is interest in estimating it. In this paper, a large two parameter model is studied and a simplified model is proposed in order to obtain optimal designs in a more suitable way. Local c-optimal designs for the main parameters are obtained using the results of López-Fidalgo and Rodríguez-Díaz, 2004). Efficiencies for all the computed designs are provided and compared

Programa de formación para profesionales de enfermería de atención primaria en la incentivación del programa de cribado de Hepatitis C

Introducción: el virus de la Hepatitis C (VHC) es el causante de un grave problema de Salud Pública. Su alta prevalencia y mortalidad ha requerido la intervención de instituciones para controlar su trasmisión. Durante la puesta en marcha de los programas de cribado se han encontrado problemas para los que se han planteado soluciones como la disminución del tiempo de acceso al tratamiento o el cribado por prácticas de riesgo. Incentivar la detección de casos es una necesidad actual a la que se debe de hacer frente para la erradicación del VHC.Objetivo: realizar un programa de formación a enfermeros de atención primaria en el que se impartirán estrategias de acción para el cribado de Hepatitis C en población con consumo de sustancias por vía parenteral.Metodología: tras realizar una búsqueda bibliográfica y a través del contacto con diferentes profesionales, se ha realizado una propuesta de programa de formación a enfermeros de atención primaria de Aragón para la adquisición de estrategias de acción en la detección de personas que consumen sustancias, cuya práctica está vinculada a una gran transmisión del VHC. Conclusiones: la puesta en marcha del programa de formación supondrá un aumento en la detección de prácticas de riesgo así como de casos no diagnosticados. La inclusión de enfermería en el programa de cribado demostrará la importancia de la educación sanitaria para el control de la infección. No obstante, la temprana edad de inicio en el consumo y la visibilización de nuevas prácticas de riesgo crean necesidades que deben ser abordadas. Palabras clave: “hepatitis C”, “prevención”, “prevalencia”, ”diagnóstico”, “cribado”, “eliminación”, “drogas”.<br /

Linear Polyethyleneimine-Based and Metal Organic Frameworks (DUT-67) Composite Hydrogels as Efficient Sorbents for the Removal of Methyl Orange, Copper Ions, and Penicillin V

This research explores the integration of DUT-67 metal organic frameworks into polyethyleneimine-based hydrogels to assemble a composite system with enough mechanical strength, pore structure and chemical affinity to work as a sorbent for water remediation. By varying the solvent-to-modulator ratio in a water-based synthesis path, the particle size of DUT-67 was successfully modulated from 1 μm to 200 nm. Once DUT-67 particles were integrated into the polymeric hydrogel, the composite hydrogel exhibited enhanced mechanical properties after the incorporation of the MOF filler. XPS, NMR, TGA, FTIR, and FT Raman studies confirmed the presence and interaction of the DUT-67 particles with the polymeric chains within the hydrogel network. Adsorption studies of methyl orange, copper(II) ions, and penicillin V on the composite hydrogel revealed a rapid adsorption kinetics and monolayer adsorption according to the Langmuir’s model. The composite hydrogel demonstrated higher adsorption capacities, as compared to the pristine hydrogel, showcasing a synergistic effect, with maximum adsorption capacities of 473 ± 21 mg L−1, 86 ± 6 mg L−1, and 127 ± 4 mg L−1, for methyl orange, copper(II) ions, and penicillin V, respectively. This study highlights the potential of MOF-based composite hydrogels as efficient adsorbents for environmental pollutants and pharmaceuticals.This research was funded by the Agencia Nacional de Promoción de la Investigación, el Desarrollo Tecnológico y la Innovación (ANPCYT, Argentina), project PICT 2019-00845; Universidad de Buenos Aires, project UBACyT 2020-2024/11BA and Ministry of Science and Innovation (Spain), project PID2021-126235OB-C32 funded by MCIN/AEI/10.13039/501100011033 and FEDER and project TED2021-130756B-C31 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe” by the European Union NextGenerationEU/PRTR. The MSCA-RISE-2017 (No 778412) INDESMOF, which received funding from the European Union’s Horizon 2020 research and innovation program, is also acknowledged

Alnus airborne pollen trends during the last 26 years for improving machine learning-based forecasting methods

Black alder (Alnus glutinosa (L.) Gaertn.) is a species of tree widespread along Europe and belongs to mixed hardwood forests. In urban environments, the tree is usually located along watercourses, as is the case in the city of Ourense. This taxon belongs to the betulaceae family, so it has a high allergenic potential in sensitive people. Due to the high allergenic capacity of this pollen type and the increase in global temperature produced by climate change, which induces a greater allergenicity, the present study proposes the implementation of a Machine Learning (ML) model capable of accurately predicting high-risk periods for allergies among sensitive people. The study was carried out in the city of Ourense for 28 years and pollen data were collected by means of the Hirst trap model Lanzoni VPPS-2000. During the same period, meteorological data were obtained from the meteorological station of METEOGALICIA in Ourense. We observed that Alnus airborne pollen was present in the study area during winter months, mainly in January and February. We found statistically significant trends for the end of the main pollen season with a lag trend of 0.68 days per year, and an increase in the annual pollen integral of 112 pollen grains per year and approximately 12 pollen grains/m3 per year during the pollen peak. A Spearman correlation test was carried out in order to select the variables for the ML model. The best ML model was Random Forest, which was able to detect those days with medium and high labels.Xunta de Galicia | Ref. ED431C 2022/03-GRCXunta de Galicia | Ref. CO-0034-2021 00V

Chitin/Metal‐Organic Framework Composites as Wide‐Range Adsorbent

Composites based on chitin (CH) biopolymer and metal-organic framework (MOF) microporous nanoparticles have been developed as broad-scope pollutant absorbent. Detailed characterization of the CH/MOF composites revealed that the MOF nanoparticles interacted through electrostatic forces with the CH matrix, inducing compartmentalization of the CH macropores that led to an overall surface area increase in the composites. This created a micro-, meso-, and macroporous structure that efficiently retained pollutants with a broad spectrum of different chemical natures, charges, and sizes. The unique prospect of this approach is the combination of the chemical diversity of MOFs with the simple processability and biocompatibility of CH that opens application fields beyond water remediation.Fil: Tovar Jimenez, Gabriel Ibrahin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; ArgentinaFil: Valverde, Ainara. Universidad del País Vasco; EspañaFil: Mendes Felipe, Cristian. Universidad del País Vasco; EspañaFil: Wuttke, Stefan. Universidad del País Vasco; EspañaFil: Fidalgo Marijuan, Arkaitz. University of the Basque Country ; EspañaFil: Larrea, Edurne S.. Loire Valley Institute for Advanced Studies, ; FranciaFil: Lezama, Luis. Universidad del País Vasco; EspañaFil: Zheng, Fangyuan. Universidad del País Vasco; EspañaFil: Reguera, Javier. Universidad del País Vasco; EspañaFil: Lanceros Méndez, Senentxu. Universidad del País Vasco; EspañaFil: Arriortua, María. Universidad del País Vasco; EspañaFil: Copello, Guillermo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; ArgentinaFil: Luis, Roberto Fernández. Universidad del País Vasco; Españ