Evaluación del cambio conceptual mediante una entrevista "en profundidad"

En este artículo se analizan algunas concepciones espontáneas que los estudiantes puedan mostrar sobre al aplicar el Principio de Acción y Reacción a diversas situaciones físicas, tratando de complementar métodos cuantitativos y cualitativos. En relación a estos últimos, se presenta el estudio de un caso mediante una "entrevista en profundidad", que fue aplicada a 18 estudiantes con edades comprendidas entra 12 y 18 años, con objeto de analizar su pensamiento implícito a lo largo del proceso de cambio conceptual

Antiferromagnetic 4-d O(4) Model

We study the phase diagram of the four dimensional O(4) model with first (beta1) and second (beta2) neighbor couplings, specially in the beta2 < 0 region, where we find a line of transitions which seems to be second order. We also compute the critical exponents on this line at the point beta1 =0 (F4 lattice) by Finite Size Scaling techniques up to a lattice size of 24, being these exponents different from the Mean Field ones.Comment: 26 pages LaTeX2e, 7 figures. The possibility of logarithmic corrections has been considered, new figures and tables added. Accepted for publication in Physical Review

Experimental study of subwavelength grating bimodal waveguides as ultrasensitive interferometric sensors

[EN] Over the recent years, subwavelength grating (SWG) structures have increasingly attracted attention in the area of evanescent-field photonic sensors. In this Letter, for the first time to the best of our knowledge, we demonstrate experimentally the real-time refractive index (RI) sensing using the SWG bimodal interferometric structures. Two different configurations are considered to compare the effect of the nonlinear phase shift, obtained between the two first transverse electromagnetic propagating modes, in the measured bulk sensitivity. Very high experimental values up to 2270 nm/RIU are reached, which perfectly match the numerical simulations and significantly enhance other existing SWG and spectralbased sensors. By measuring the spectral shift, the obtained experimental sensitivity does not depend on the sensor length. As a result, a highly sensitive and compact singlechannel interferometer is experimentally validated for refractive index sensing, thus opening new paths in the field of optical integrated sensors.European Commission (PHC-634013 PHOCNOSIS project); Spanish Government (TEC2015-63838-C3-1-R-OPTONANOSENS project); Universitat Politecnica de Valencia (grant PAID 01-18).Torrijos-Morán, L.; Griol Barres, A.; García-Rupérez, J. (2019). Experimental study of subwavelength grating bimodal waveguides as ultrasensitive interferometric sensors. Optics Letters. 44(19):4702-4705. https://doi.org/10.1364/OL.44.004702S470247054419Cheben, P., Xu, D.-X., Janz, S., & Densmore, A. (2006). Subwavelength waveguide grating for mode conversion and light coupling in integrated optics. Optics Express, 14(11), 4695. doi:10.1364/oe.14.004695Schmid, J. H., Cheben, P., Janz, S., Lapointe, J., Post, E., & Xu, D.-X. (2007). Gradient-index antireflective subwavelength structures for planar waveguide facets. Optics Letters, 32(13), 1794. doi:10.1364/ol.32.001794Bock, P. J., Cheben, P., Schmid, J. H., Lapointe, J., Delâge, A., Janz, S., … Hall, T. J. (2010). Subwavelength grating periodic structures in silicon-on-insulator: a new type of microphotonic waveguide. Optics Express, 18(19), 20251. doi:10.1364/oe.18.020251Halir, R., Bock, P. J., Cheben, P., Ortega‐Moñux, A., Alonso‐Ramos, C., Schmid, J. H., … Janz, S. (2014). Waveguide sub‐wavelength structures: a review of principles and applications. Laser & Photonics Reviews, 9(1), 25-49. doi:10.1002/lpor.201400083Cheben, P., Halir, R., Schmid, J. H., Atwater, H. A., & Smith, D. R. (2018). Subwavelength integrated photonics. Nature, 560(7720), 565-572. doi:10.1038/s41586-018-0421-7Gonzalo Wangüemert-Pérez, J., Cheben, P., Ortega-Moñux, A., Alonso-Ramos, C., Pérez-Galacho, D., Halir, R., … Schmid, J. H. (2014). Evanescent field waveguide sensing with subwavelength grating structures in silicon-on-insulator. Optics Letters, 39(15), 4442. doi:10.1364/ol.39.004442Donzella, V., Sherwali, A., Flueckiger, J., Grist, S. M., Fard, S. T., & Chrostowski, L. (2015). Design and fabrication of SOI micro-ring resonators based on sub-wavelength grating waveguides. Optics Express, 23(4), 4791. doi:10.1364/oe.23.004791Flueckiger, J., Schmidt, S., Donzella, V., Sherwali, A., Ratner, D. M., Chrostowski, L., & Cheung, K. C. (2016). Sub-wavelength grating for enhanced ring resonator biosensor. Optics Express, 24(14), 15672. doi:10.1364/oe.24.015672Yan, H., Huang, L., Xu, X., Chakravarty, S., Tang, N., Tian, H., & Chen, R. T. (2016). Unique surface sensing property and enhanced sensitivity in microring resonator biosensors based on subwavelength grating waveguides. Optics Express, 24(26), 29724. doi:10.1364/oe.24.029724Huang, L., Yan, H., Xu, X., Chakravarty, S., Tang, N., Tian, H., & Chen, R. T. (2017). Improving the detection limit for on-chip photonic sensors based on subwavelength grating racetrack resonators. Optics Express, 25(9), 10527. doi:10.1364/oe.25.010527Benedikovic, D., Berciano, M., Alonso-Ramos, C., Le Roux, X., Cassan, E., Marris-Morini, D., & Vivien, L. (2017). Dispersion control of silicon nanophotonic waveguides using sub-wavelength grating metamaterials in near- and mid-IR wavelengths. Optics Express, 25(16), 19468. doi:10.1364/oe.25.019468Halir, R., Cheben, P., Luque‐González, J. M., Sarmiento‐Merenguel, J. D., Schmid, J. H., Wangüemert‐Pérez, G., … Molina‐Fernández, Í. (2016). Ultra‐broadband nanophotonic beamsplitter using an anisotropic sub‐wavelength metamaterial. Laser & Photonics Reviews, 10(6), 1039-1046. doi:10.1002/lpor.201600213Luque-González, J. M., Herrero-Bermello, A., Ortega-Moñux, A., Molina-Fernández, Í., Velasco, A. V., Cheben, P., … Halir, R. (2018). Tilted subwavelength gratings: controlling anisotropy in metamaterial nanophotonic waveguides. Optics Letters, 43(19), 4691. doi:10.1364/ol.43.004691Jahani, S., Kim, S., Atkinson, J., Wirth, J. C., Kalhor, F., Noman, A. A., … Jacob, Z. (2018). Controlling evanescent waves using silicon photonic all-dielectric metamaterials for dense integration. Nature Communications, 9(1). doi:10.1038/s41467-018-04276-8Torrijos-Morán, L., & García-Rupérez, J. (2019). Single-channel bimodal interferometric sensor using subwavelength structures. Optics Express, 27(6), 8168. doi:10.1364/oe.27.008168Levy, R., & Ruschin, S. (2009). Design of a Single-Channel Modal Interferometer Waveguide Sensor. IEEE Sensors Journal, 9(2), 146-1. doi:10.1109/jsen.2008.2011075Zinoviev, K. E., Gonzalez-Guerrero, A. B., Dominguez, C., & Lechuga, L. M. (2011). Integrated Bimodal Waveguide Interferometric Biosensor for Label-Free Analysis. Journal of Lightwave Technology, 29(13), 1926-1930. doi:10.1109/jlt.2011.2150734Kozma, P., Kehl, F., Ehrentreich-Förster, E., Stamm, C., & Bier, F. F. (2014). Integrated planar optical waveguide interferometer biosensors: A comparative review. Biosensors and Bioelectronics, 58, 287-307. doi:10.1016/j.bios.2014.02.049Levy, R., & Ruschin, S. (2008). Critical sensitivity in hetero-modal interferometric sensor using spectral interrogation. Optics Express, 16(25), 20516. doi:10.1364/oe.16.020516García-Rupérez, J., Toccafondo, V., Bañuls, M. J., Castelló, J. G., Griol, A., Peransi-Llopis, S., & Maquieira, Á. (2010). Label-free antibody detection using band edge fringes in SOI planar photonic crystal waveguides in the slow-light regime. Optics Express, 18(23), 24276. doi:10.1364/oe.18.024276Zhang, W., Serna, S., Le Roux, X., Vivien, L., & Cassan, E. (2016). Highly sensitive refractive index sensing by fast detuning the critical coupling condition of slot waveguide ring resonators. Optics Letters, 41(3), 532. doi:10.1364/ol.41.000532Di Falco, A., O’Faolain, L., & Krauss, T. F. (2009). Chemical sensing in slotted photonic crystal heterostructure cavities. Applied Physics Letters, 94(6), 063503. doi:10.1063/1.3079671Molina-Fernández, Í., Leuermann, J., Ortega-Moñux, A., Wangüemert-Pérez, J. G., & Halir, R. (2019). Fundamental limit of detection of photonic biosensors with coherent phase read-out. Optics Express, 27(9), 12616. doi:10.1364/oe.27.01261

Phlebotominae (Diptera: psycodidae) fauna in the Chaco region and Cutaneous Leishmaniasis transmission patterns in Argentina

In Argentina, the incidence of American Cutaneous Leishmaniasis (ACL) has shown a steady increase over the last few decades. In the Chaco biogeographical region, specifically, several outbreaks of ACL were recently reported in addition to the usual time-space scattering of ACL cases. However, little is known about the sandfly composition in the eastern, humid Chaco (HC) region or the western, dry Chaco (DC) region. Therefore, phlebotomine captures were performed throughout this region and an analysis of the distribution of reported ACL cases was conducted in order to assess the vector diversity in ACL endemic and epidemic scenarios in the Chaco region. The results support the hypothesis of two distinct patterns: (1) the DC, where Lutzomyia migonei was the most prevalent species, had isolated ACL cases and a zoonotic cycle; (2) the HC, where Lutzomyia neivai was the most prevalent species, had an increase in ACL incidence and outbreaks and an anthropozoonotic cycle. The epidemic risk in the Chaco region may be associated with the current climate trends, landscape modification, connection with other ACL foci, and Lu. neivai predominance and abundance. Therefore, changes in sandfly population diversity and density in the Chaco region are an indicator of emergent epidemic risk in sentinel capture sites.Facultad de Ciencias Naturales y Muse

High-resolution genome screen for bone mineral density in heterogeneous stock rat

We previously demonstrated that skeletal mass, structure, and biomechanical properties vary considerably in heterogeneous stock (HS) rat strains. In addition, we observed strong heritability for several of these skeletal phenotypes in the HS rat model, suggesting that it represents a unique genetic resource for dissecting the complex genetics underlying bone fragility. The purpose of this study was to identify and localize genes associated with bone mineral density in HS rats. We measured bone phenotypes from 1524 adult male and female HS rats between 17 and 20 weeks of age. Phenotypes included dual-energy X-ray absorptiometry (DXA) measurements for bone mineral content and areal bone mineral density (aBMD) for femur and lumbar spine (L3-L5), and volumetric BMD measurements by CT for the midshaft and distal femur, femur neck, and fifth lumbar vertebra (L5). A total of 70,000 polymorphic single-nucleotide polymorphisms (SNPs) distributed throughout the genome were selected from genotypes obtained from the Affymetrix rat custom SNPs array for the HS rat population. These SNPs spanned the HS rat genome with a mean linkage disequilibrium coefficient between neighboring SNPs of 0.95. Haplotypes were estimated across the entire genome for each rat using a multipoint haplotype reconstruction method, which calculates the probability of descent for each genotyped locus from each of the eight founder HS strains. The haplotypes were tested for association with each bone density phenotype via a mixed model with covariate adjustment. We identified quantitative trait loci (QTLs) for BMD phenotypes on chromosomes 2, 9, 10, and 13 meeting a conservative genomewide empiric significance threshold (false discovery rate [FDR] = 5%; p < 3 × 10(-6)). Importantly, most QTLs were localized to very small genomic regions (1-3 megabases [Mb]), allowing us to identify a narrow set of potential candidate genes including both novel genes and genes previously shown to have roles in skeletal development and homeostasis

Fine mapping of bone structure and strength QTLs in heterogeneous stock rat

We previously demonstrated that skeletal structure and strength phenotypes vary considerably in heterogeneous stock (HS) rats. These phenotypes were found to be strongly heritable, suggesting that the HS rat model represents a unique genetic resource for dissecting the complex genetic etiology underlying bone fragility. The purpose of this study was to identify and localize genes associated with bone structure and strength phenotypes using 1524 adult male and female HS rats between 17 to 20 weeks of age. Structure measures included femur length, neck width, head width; femur and lumbar spine (L3-5) areas obtained by DXA; and cross-sectional areas (CSA) at the midshaft, distal femur and femoral neck, and the 5th lumbar vertebra measured by CT. In addition, measures of strength of the whole femur and femoral neck were obtained. Approximately 70,000 polymorphic SNPs distributed throughout the rat genome were selected for genotyping, with a mean linkage disequilibrium coefficient between neighboring SNPs of 0.95. Haplotypes were estimated across the entire genome for each rat using a multipoint haplotype reconstruction method, which calculates the probability of descent at each locus from each of the 8 HS founder strains. The haplotypes were then tested for association with each structure and strength phenotype via a mixed model with covariate adjustment. We identified quantitative trait loci (QTLs) for structure phenotypes on chromosomes 3, 8, 10, 12, 17 and 20, and QTLs for strength phenotypes on chromosomes 5, 10 and 11 that met a conservative genome-wide empiric significance threshold (FDR=5%; P<3×10(-6)). Importantly, most QTLs were localized to very narrow genomic regions (as small as 0.3 Mb and up to 3 Mb), each harboring a small set of candidate genes, both novel and previously shown to have roles in skeletal development and homeostasis

The burden of 14 hr-HPV genotypes in women attending routine cervical cancer screening in 20 states of Mexico: a cross-sectional study

In Mexico, HPV vaccines available immunize against genotypes 16/18 and 16/18/6/11; however, there is limited surveillance about carcinogenic subtypes in different states of the country that allow evaluating the effectiveness of vaccination and cervical cancer screening programs. Here, we report the regional and age-specific prevalence of 14 hr-HPV genotypes as well as their prevalence in abnormal cytology (from ASCUS to cervical cancer) among Mexican women which were undergoing from cervical cancer screening in the Salud Digna clinics in 20 states of the country. This study includes women with social security from the majority of public health institutions (IMSS, ISSSTE, SEMAR, and PEMEX), and women without social security. For cervical cancer screening, we used the SurePath liquid-based cytology and the BD Onclarity HPV Assay. From December 1, 2016, to August 2, 2018, the hr-HPV prevalence among 60,135 women was 24.78%, the most prevalent types were HPV 16 (4.13%), HPV 31 (4.12%) and HPV 51 (3.39%), while HPV 18 (1.70%) was less prevalent among infected women. Interestingly, the genotypes not covered by current vaccines in Mexico were commonly found in precancerous lesions, evidencing their carcinogenic potential, so it is necessary to increase their surveillance and inclusion in cervical cancer screening triage.We gratefully acknowledge to Iromy Meza, Jessica Avitia, and Oswaldo Carrillo for their technical support in obtaining databases during this project. Also, we want to thanks the staff of the Salud Digna clinics and the National Reference Center of Salud Digna for their support during this work. This work was funding by Salud Digna

Coordinación entre las asignaturas del área de ingeniería térmica y energía de los grados y el Máster Universitario en Ingeniería Naval y Oceánica de la Universidad Politécnica de Madrid

El trabajo que se presenta tiene por objetivo establecer la coordinación existente entre los objetivos y actividades de las asignaturas del área de ingeniería térmica, energía y propulsión del Máster en Ingeniería Naval y Oceánica, y los objetivos y actividades del mismo tipo de asignaturas en los Grados en Ingeniería Marítima y en Arquitectura Naval de la ETSI Navales de la Universidad Politécnica de Madrid. Igualmente, se plantea estudiar la coordinación de estas materias entre sí dentro de los Grados. Pueden mencionarse asignaturas obligatorias tales como Termodinámica, Ingeniería Térmica, Energía y Propulsión, Motores Diésel Marinos, Turbomáquinas Térmicas y Diseño integral de plantas de Energía y Propulsión. Entre las asignaturas optativas se encuentran Refrigeración y Climatización en Buques y Tecnología de las Pilas de Combustible y Energía del Hidrógeno. Para poder coordinar dos especialidades de Grado universitario con campos tan dispares, pero a la vez tan relacionados, con el Máster Universitario que se cursará en ambos casos, se deben exigir unas pautas muy marcadas para no solapar las actividades y/o habilidades necesarias para alcanzar dichas capacidades. De la necesidad de comprender mejor y con mayor exactitud las necesidades de cada uno de los planes de estudios en el área de ingeniería térmica, energía y propulsión, y más concretamente, las relaciones que existen entre ellos, nace este trabajo. Para mejorar la eficacia de la enseñanza de los actuales y futuros alumnos, será fundamental desarrollar, entre otras, una serie de acciones que incluyen un estudio a fondo de los objetivos del Máster y de los Grados en relación con estas materias; el diseño y aplicación de una plantilla de descripción de las asignaturas en Máster y en Grado, que permita la elaboración de árboles de relación entre Máster-Grados; partiendo del Máster que vinculen los objetivos, las competencias generales, específicas y transversales (y el nivel de desarrollo propuesto) y los conocimientos previos; la confección y análisis de encuestas dirigidas a alumnos egresados, profesores y empresas, que emplean a estos alumnos con el fin de evaluar el nivel de consecución de los objetivos planteados. Esto permitirá determinar, en cuanto al área de ingeniería térmica, energía y propulsión, la viabilidad de la consecución de los objetivos del Máster en función de los objetivos planteados en los Grados al identificar vacíos y redundancias en cuanto a los objetivos, las competencias y los conocimientos previos del Máster en relación con los Grados. Con todo ello será posible proponer las modificaciones oportunas, en los casos en los que se consideren necesarias.Los autores desean agradecer a la Universidad Politécnica de Madrid su soporte y ayuda en este trabajo, en el marco del Proyecto de Innovación Educativa IE1415-08002

Major role of nutrient supply in the control of picophytoplankton community structure.

abstractThe Margalef´s mandala (1978) is a simplified bottom-up control model that explains how mixing and nutrient concentration determine the composition of marine phytoplankton communities. Due to the difficulties of measuring turbulence in the field, previous attempts to verify this model have applied different proxies for nutrient supply, and very often used interchangeably the terms mixing and stratification. Moreover, because the mandala was conceived before the discovery of smaller phytoplankton groups (picoplankton <2 μm), it describes only the succession of vegetative phases of microplankton. In order to test the applicability of the classical mandala to picoplankton groups, we used a multidisciplinary approach including specifically designed field observations supported by remote sensing, database analyses, and modeling and laboratory chemostat experiments. Simultaneous estimates of nitrate diffusive fluxes, derived from microturbulence observations, and picoplankton abundance collected in more than 200 stations, spanning widely different hydrographic regimes, showed that the contribution of eukaryotes to picoautotrophic biomass increases with nutrient supply, whereas that of picocyanobacteria shows the opposite trend. These findings were supported by laboratory and modeling chemostat experiments that reproduced the competitive dynamics between picoeukaryote sand picocyanobacteria as a function of changing nutrient supply. Our results indicate that nutrient supply controls the distribution of picoplankton functional groups in the ocean, further supporting the model proposed by Margalef.RADIALES (IEO

Phlebotominae (Diptera: psycodidae) fauna in the Chaco region and Cutaneous Leishmaniasis transmission patterns in Argentina

In Argentina, the incidence of American Cutaneous Leishmaniasis (ACL) has shown a steady increase over the last few decades. In the Chaco biogeographical region, specifically, several outbreaks of ACL were recently reported in addition to the usual time-space scattering of ACL cases. However, little is known about the sandfly composition in the eastern, humid Chaco (HC) region or the western, dry Chaco (DC) region. Therefore, phlebotomine captures were performed throughout this region and an analysis of the distribution of reported ACL cases was conducted in order to assess the vector diversity in ACL endemic and epidemic scenarios in the Chaco region. The results support the hypothesis of two distinct patterns: (1) the DC, where Lutzomyia migonei was the most prevalent species, had isolated ACL cases and a zoonotic cycle; (2) the HC, where Lutzomyia neivai was the most prevalent species, had an increase in ACL incidence and outbreaks and an anthropozoonotic cycle. The epidemic risk in the Chaco region may be associated with the current climate trends, landscape modification, connection with other ACL foci, and Lu. neivai predominance and abundance. Therefore, changes in sandfly population diversity and density in the Chaco region are an indicator of emergent epidemic risk in sentinel capture sites.Facultad de Ciencias Naturales y Muse