El discurso matemático del profesor: ejemplos, explicaciones y coherencia local

Se examina el discurso matemático de un profesor a lo largo de una discusión de clase, con inspiración en el marco MDI –Mathematical Discourse in Instruction. Se interpretan momentos de selección y secuenciación de ejemplos y explicaciones durante la resolución del problema del reparto de una apuesta en un juego interrumpido. Para ello, aplicamos una noción de coherencia local que alude al cumplimiento de condiciones sobre la selección, secuenciación y conexión de ejemplos y explicaciones. Se concluye que la coherencia local del discurso es mayor en los momentos en los cuales se aportan ejemplos con una función refutadora y desestabilizadora del razonamiento proporcional inicialmente utilizado por los alumnos, y a la vez explicaciones con una función modeladora hacia el concepto de probabilidad que se pretende introducir

Analysis of FPGA filter in computed tomography images for radioactive dose reduction

[EN] X-Ray or CT (computed tomography) images may have noise due to image acquisition process. As contaminated images complicate diagnosis many filters have been developed to overcome this problem. In this work we study the behavior of a Fuzzy method called FPGA, which detect and correct impulsive and Gaussian noise, used over a medical image obtained from the mini-MIAS database that has been altered with impulsive and/or Gaussian noise. The aim of the study is verify if FPGA is a candidate to be used as a method to reduce the radiation dose in CT. Results show that FPGA outperforms the rest of the methods studied and it reveals itself as a good candidate to be employed in CT images to reduce the radiation dose.[ES] Las imágenes de Rayos-X o de tomografía computarizada (CT) pueden contener ruido debido al proceso de adquisición. Este ruido complica sustancialmente el proceso diagnóstico, por lo que será necesario el desarrollo de filtros efectivos. En este trabajo se estudia el comportamiento del filtro Fuzzy Peer Group Averaging (Fuzzy PGA) sobre una colección de imágenes mamográficas que ha sido previamente contaminada con ruido impulsivo y gaussiano. El objetivo del trabajo es averiguar si Fuzzy PGA es adecuado para la mejora de imágenes CT obtenidas con una dosis de radiación reducida. Los resultados indican que Fuzzy PGA se comporta, efectivamente, mejor que el resto de métodos estudiados en este trabajo y por tanto resulta un candidato adecuado.Parcero Iglesias, E.; Vidal Gimeno, VE.; Verdú Martín, GJ.; Arnal García, J. (2014). Analysis of FPGA filter in computed tomography images for radioactive dose reduction. Grupo Senda. http://hdl.handle.net/10251/49701

Análisis del Filtro FPGA en Imágenes de Tomografía Computarizada para la Reducción de Dosis Radiactiva

[EN] X-Ray or CT (computed tomography) images may have noise due to image acquisition process. As contaminated images complicate diagnosis many filters have been developed to overcome this problem. In this work we study the behavior of a Fuzzy method called FPGA, which detect and correct impulsive and Gaussian noise, used over a medical image obtained from the mini-MIAS database that has been altered with impulsive and/or Gaussian noise. The aim of the study is verify if FPGA is a candidate to be used as a method to reduce the radiation dose in CT. Results show that FPGA outperforms the rest of the methods studied and it reveals itself as a good candidate to be employed in CT images to reduce the radiation dose.[ES] Las imágenes de Rayos-X o de tomografía computarizada (CT) pueden contener ruido debido al proceso de adquisición. Este ruido complica sustancialmente el proceso diagnóstico, por lo que será necesario el desarrollo de filtros efectivos. En este trabajo se estudia el comportamiento del filtro Fuzzy Peer Group Averaging (FPGA) sobre una colección de imágenes mamográficas que ha sido previamente contaminada con ruido impulsivo y gaussiano. El objetivo del trabajo es averiguar si FPGA es adecuado para la mejora de imágenes CT obtenidas con una dosis de radiación reducida. Los resultados indican que FPGA se comporta, efectivamente, mejor que el resto de métodos estudiados en este trabajo y por tanto resulta un candidato adecuado.This work was partially funded by ANITRAN PROMETEO/2010/039, the Spanish Ministry of Science and Innovation (Project TIN2008-06570-C04-04), and the spin-off Titania (Grupo Dominguis).Parcero Iglesias, E.; Vidal Gimeno, VE.; Verdú Martín, GJ.; Josep Arnal García; Mayo Nogueira, P. (2014). Análisis del Filtro FPGA en Imágenes de Tomografía Computarizada para la Reducción de Dosis Radiactiva. Sociedad Nuclear Española. http://hdl.handle.net/10251/70824

Viability, method and device for horticultural crops with brackish and marine water

The method that humanity has adopted to hydrate and thus give life to the plants, imitating the model that was most visible, is the rain. However, the great secret to the contribution of nutrients to the vegetables, the irrigation itself, is on earth, in the groundwater layers and aquifers that hoard and administer the water, keeping every drop of rain and distributing the water through the basins, underground rivers, watering indirectly from the mountain to the sea. The key is in the different circulation velocities of the groundwater because of the nature of the substrates. However, agriculture has taken irrigation from above as we know it and has focused especially on drainage capacity. From this point of view, saline water is not beneficial for irrigated agriculture, but may be the only source of irrigation water in large arid regions, especially in developing countries, where the extreme scarcity of freshwater and the rapidly growing population require more water. When considering the possibility of watering with seawater without desalinating, always by means of capillarity systems, it is essential to take into consideration the different strata of soils, the distance to the groundwater, the composition of seawater, the capacity of drainage, chemical reactions of the soil with salts, etc. The modification of any of these parameters can produce effects of salinization, loss of humidity or desertification among others. This study presents the accumulated experience through the joint collaboration between the Centre for Research in Security and food Control of the Polytechnic University of Catalonia (CRESCA) and the Aqua Maris Foundation in capillary irrigation and it proposes a system and device that allows the controlled development of different vegetal species using brackish and seawaterPostprint (published version

Decapod crustaceans from the Lower Cretaceous of Spain, with an account of new occurrences in Barremian-Aptian strata of the Maestrazgo Basin

Decapod crustaceans are rare in Early Cretaceous invertebrate assemblages from the Iberian Peninsula; however, current knowledge does allow differences in taxonomic composition between different basins and subbasins to be recognised. In order to understand the distribution of Barremian–Aptian decapod crustaceans of Iberia better, seven new localities in the Galve subbasin (Maestrazgo Basin, north-east Spain) have been sampled. Seven taxa are here described, including the anomurans Cretacocalcinus fortis sp. nov. and Viapagurus gen. nov. (type species: Pagurus avellanedai Vía, 1951), one indeterminate axiidean, the astacidean Hoploparia sp., plus the brachyurans Ariecornibus sp., Pithonoton lluismariaorum Ossó, van Bakel, Ferratges-Kwekel and Moreno-Bedmar, 2018 and Palaeodromites pimientai sp. nov. Assemblages are characterised by low abundance, being found in formations that represent depositional settings ranging from shallow-marine platforms to deeper marine bottoms. Some taxa, such as V. avellanedai and P. lluismariaorum, are also known from other subbasins of the Maestrazgo Basin but, in general, most appear endemic, suggesting that regional changes in facies distribution may potentially have affected differences in taxonomic composition

Precisiones sobre la edad de la base de la Fm. Escucha, mediante ammonoideos, en la subcuenca de la Salzedella, Cuenca del Maestrat (E Cordillera Ibérica).

La edad de la parte basal de la Formación Escucha, Cuenca del Maestrat, ha sido objeto de distintas interpretaciones, resultando edades comprendidas desde el Aptiense superior al Albiense superior. En la subcuenca de la Salzedella, depocentro de la cuenca, esta formación presenta en su parte basal un registro de ammonites. Para precisar su edad se han estudiado los ammonites citados anteriormente por otros autores, los de colecciones particulares, hasta el presente inéditas y a las que hemos tenido acceso por vez primera, además de los recolectados en una nueva sección levantada en esta parte basal de la formación. Su estudio ha permitido reconocer una asociación con profusión de engonocerátidos, Parengoneceras caneroti Collignon, junto a douvilleicerátidos e hypacanthoplítidos. El análisis bioestratigráfico y comparativo con otras asociaciones similares, francesas, inglesas y tunecinas, permite datar la asociación como del Albiense inferior, Biozona Leymeriella tarfurcata y probablemente la parte inferior de la Biozona Douvilleiceras mammillatum

Diagnosis delay and follow-up strategies in colorectal cancer. Prognosis implications: a study protocol

<p>Abstract</p> <p>Background</p> <p>Controversy exists with regard to the impact that the different components of diagnosis delay may have on the degree of invasion and prognosis in patients with colorectal cancer. The follow-up strategies after treatment also vary considerably. The aims of this study are: a) to determine if the symptoms-to-diagnosis interval and the treatment delay modify the survival of patients with colorectal cancer, and b) to determine if different follow-up strategies are associated with a higher survival rate.</p> <p>Methods/Design</p> <p>Multi-centre study with prospective follow-up in five regions in Spain (Galicia, Balearic Islands, Catalonia, Aragón and Valencia) during the period 2010-2012. Incident cases are included with anatomopathological confirmation of colorectal cancer (International Classification of Diseases 9th revision codes 153-154) that formed a part of a previous study (n = 953).</p> <p>At the time of diagnosis, each patient was given a structured interview. Their clinical records will be reviewed during the follow-up period in order to obtain information on the explorations and tests carried out after treatment, and the progress of these patients.</p> <p>Symptoms-to-diagnosis interval is defined as the time calculated from the diagnosis of cancer and the first symptoms attributed to cancer. Treatment delay is defined as the time elapsed between diagnosis and treatment. In non-metastatic patients treated with curative intention, information will be obtained during the follow-up period on consultations performed in the digestive, surgery and oncology departments, as well as the endoscopies, tumour markers and imaging procedures carried out.</p> <p>Local recurrence, development of metastases in the follow-up, appearance of a new tumour and mortality will be included as outcome variables.</p> <p>Actuarial survival analysis with Kaplan-Meier curves, Cox regression and competitive risk survival analysis will be performed.</p> <p>Discussion</p> <p>This study will make it possible to verify if the different components of delay have an impact on survival rate in colon cancer and rectal cancer. In consequence, this multi-centre study will be able to detect the variability present in the follow-up of patients with colorectal cancer, and if this variability modifies the prognosis. Ideally, this study could determine which follow-up strategies are associated with a better prognosis in colorectal cancer.</p

Long daytime napping is associated with increased adiposity and type 2 diabetes in an elderly population with metabolic syndrome

Research examining associations between objectively-measured napping time and type 2 diabetes (T2D) is lacking. This study aimed to evaluate daytime napping in relation to T2D and adiposity measures in elderly individuals from the Mediterranean region. A cross-sectional analysis of baseline data from 2190 elderly participants with overweight/obesity and metabolic syndrome, in the PREDIMED-Plus trial, was carried out. Accelerometer-derived napping was measured. Prevalence ratios (PR) and 95% confidence intervals (CI) for T2D were obtained using multivariable-adjusted Cox regression with constant time. Linear regression models were fitted to examine associations of napping with body mass index (BMI) and waist circumference (WC). Participants napping ≥90 min had a higher prevalence of T2D (PR 1.37 (1.06, 1.78)) compared with those napping 5 to <30 min per day. Significant positive associations with BMI and WC were found in those participants napping ≥30 min as compared to those napping 5 to <30 min per day. The findings of this study suggest that longer daytime napping is associated with higher T2D prevalence and greater adiposity measures in an elderly Spanish population at high cardiovascular risk

The Helicobacter pylori Genome Project : insights into H. pylori population structure from analysis of a worldwide collection of complete genomes

Helicobacter pylori, a dominant member of the gastric microbiota, shares co-evolutionary history with humans. This has led to the development of genetically distinct H. pylori subpopulations associated with the geographic origin of the host and with differential gastric disease risk. Here, we provide insights into H. pylori population structure as a part of the Helicobacter pylori Genome Project (HpGP), a multi-disciplinary initiative aimed at elucidating H. pylori pathogenesis and identifying new therapeutic targets. We collected 1011 well-characterized clinical strains from 50 countries and generated high-quality genome sequences. We analysed core genome diversity and population structure of the HpGP dataset and 255 worldwide reference genomes to outline the ancestral contribution to Eurasian, African, and American populations. We found evidence of substantial contribution of population hpNorthAsia and subpopulation hspUral in Northern European H. pylori. The genomes of H. pylori isolated from northern and southern Indigenous Americans differed in that bacteria isolated in northern Indigenous communities were more similar to North Asian H. pylori while the southern had higher relatedness to hpEastAsia. Notably, we also found a highly clonal yet geographically dispersed North American subpopulation, which is negative for the cag pathogenicity island, and present in 7% of sequenced US genomes. We expect the HpGP dataset and the corresponding strains to become a major asset for H. pylori genomics