Creating a semantic segmentation machine learning model for sea ice detection on radar images to study the Thwaites region

This thesis presents a deep learning tool able to identify ice in radar images from the sea-ice environment of the Thwaites glacier outlet. The project is motivated by the threatening situation of the Thwaites glacier that has been increasing its mass loss rate during the last decade. This is of concern considering the large mass of ice held by the glacier, that in case of melting, could increase the mean sea level by more than +65 cm [1]. The algorithm generated along this work is intended to help in the generation of navigation charts and identification of icebergs in future stages of the project, outside of the scope of this thesis. The data used for this task are ICEYE’s X-band radar images from the Thwaites sea-ice environment, the target area to be studied. The corresponding ground truth for each of the samples has been manually generated identifying the ice and icebergs present in each image. Additional data processing includes tiling, to increment the number of samples, and augmentation, done by horizontal and vertical flips of a random number of tiles. The proposed tool performs semantic segmentation on radar images classifying the class "Ice". It is developed by a deep learning Convolutional Neural Network (CNN) model, trained with prepared ICEYE’s radar images. The model reaches values of F1 metric higher than 89% in the images of the target area (Thwaites sea-ice environment) and is able to generalize to different regions of Antarctica, reaching values of F 1 = 80 %. A potential alternative version of the algorithm is proposed and discussed. This alternative score F 1 values higher than F 1 > 95 % for images of the target environment and F 1 = 87 % for the image of the different region. However, it must not be confirmed as the final algorithm due to the need for further verification

Asma bronquial: IgE factor de riesgo en niños sanos

Tipo de estudio: prospectivo, transversal, analítico.Objetivo: Conocer los factores de riesgo para desarrollar enfermedades alérgicas y/o asma bronquial que elevan la Inmunoglobulina E total (IgE).Materiales y métodos: Se estudió la incidencia y los valores de riesgo de IgE en 203 niños sanos, de 2-26 meses, y se compararon entre los niños que tenían o no factores de riesgo. Para encontrar significancia estadística se usó la prueba chi2.Resultados: La IgE como factor de riesgo se encontró: en varones, hijos de madres asmáticas (p=0.005) y con <3Kg de peso al nacer (p<0.01); en niños alimentados con seno materno y fórmula (p<0.01); en presencia de alergenos intradomiciliarios (p=0.001) y en hijos de madres fumadoras (p<0.001). La incidencia de niveles elevados IgE fue del 80%.Conclusión: La alta incidencia de los valores de riesgo de IgE justifica la realización de nuevos estudios

El problema de l’escola rural durant la Segona República

[email protected] [email protected] manca d’identitat pròpia és el tret que millor ha caracteritzat la nostra escola rural. Nascuda a imitació de la urbana, ni polítics ni pedagogs s’han preocupat de la seva peculiaritat, teixint, al seu voltant, una història d’oblits, marginació i penúria. L’arribada de la Segona República, però, va encetar una nova etapa en què se li dedicava una certa atenció, en considerar el seu desenvolupament com a exigència irrenunciable per a la construcció de la República democràtica. En aquest article ens proposem, després d’una ràpida mirada històrica al voltant dels seus aspectes materials, organitzatius i pedagògics, analitzar els problemes que afecten aquests mateixos aspectes durant el període republicà, per tal de mostrar fins a quin punt fou o no objecte d’actuació preferent en la teoria i la pràctica de la seva política educativa. A més, analitzem el paper del magisteri rural, una part del qual es va convertir, mitjançant la formació de ciutadans republicans, en factor dinamitzador de l’escola i de la mateixa societat.Lack of identity is the most characteristic trait of our rural schools. The rural school emerged as an imitation of the town or city school, and neither politicians nor pedagogues ever addressed its singularity, and have woven a history of oblivion, marginalisation and poverty around it. However, the advent of the Second Republic heralded a new stage, when it was afforded a certain degree of attention, as its development was regarded as a keystone in the construction of the democratic Republic. In this article, and following an overview of its material, organisational and pedagogical aspects, we go on to analyse the problems that affects these selfsame aspects throughout the Republic in order to demonstrate to what extent it was or was not a preferential target in the theory and practice of the Republic’s educational policy. Moreover, we analyse the role of the rural teaching profession, a part of which became, through the formation of republican citizens, a dynamising factor of the school and [email protected] [email protected]

“Efectos de la disyunción rápida maxilar sobre el ancho nasal en teleradiografías frontales”

El objetivo de este trabajo ha sido evaluar los efectos de la expansión rápida maxilar sobre el ancho nasal, en telerradiografías frontales de individuos entre 10 y 15 años con hipoplasia maxilar de la ciudad de Córdoba. Se valoraron 40 teleradiografías frontales de pacientes con hipoplasia maxilar, 20 pre y 20 post tratamiento. El grupo de estudio estuvo formado por 20 casos clínicos con compresión maxilar y cuyo único tratamiento consistió en una expansión rápida maxilar. Todas las teleradiografías fueron sometidas a un proceso de calibración, donde se midió el ancho intermolar superior, el ancho intermaxilar y el ancho nasal según el cefalograma frontal de Ricketts. Los datos obtenidos fueron comparados (prueba t de Student) y correlacionados (coeficiente de correlación de Pearson). Los resultados confirmaron que existe una correlación positiva en la respuesta que tuvieron las variables analizadas (ancho nasal, ancho maxilar y ancho intermolar), es decir que cuando una aumenta la otra lo hace en proporción constante. Nuestros resultados sugieren que, “La disyunción maxilar produce un aumento estructural del ancho nasal en el plano transversal”.Fil: Soria, Marina del Carmen. Universidad Nacional de Córdoba. Facultad de Odontología; Argentina

Genetic variation in the IFITM locus and its phenotypic consequences

In the past few years, interferon-induced transmembrane (IFITM) proteins have been identified as important antiviral factors. The current understanding of IFITMs suggests that they localise within distinct cellular compartments from where they exert their broad antiviral role. For example, IFITM1 localises to the plasma membrane and restricts viruses that do not require endocytosis to infect host cells. In contrast, IFITM2 and IFITM3 are found in the early and late endosomes, respectively, and are potent inhibitors of viruses that depend on endosomal pathways for infection. I begin this dissertation by providing some background on the biology and function of IFITM proteins, including details of in vitro assays that have helped elucidate IFITMs role as antiviral factors. I also describe some early candidate-gene association studies that have attempted to correlate genetic variation within these genes with variation in viral restriction. I also describe how genetic association studies have been used more broadly to understand the biology underlying both infectious and non-communicable diseases. Evidence from in vitro, and in vivo work has demonstrated the IFITMs role as potent antiviral factors, however, no genome-wide association study has reported any significant associations to genetic variant in or around these genes. In Chapter 2, I explore reasons why this may be the case and calculate the coverage of IFITM genes by commercially available genotyping arrays. I show that IFITM2 and IFITM3 are amongst the 7% of all protein coding genes with less than 25% common variant (minor allele frequency > 5%) coverage across all arrays. Poor coverage of genetic variation is therefore one explanation for the lack of IFITM associations in GWAS. The lack of coverage in the genotyping arrays led me to explore other tools to capture variation in the IFITM region. I employ a targeted sequencing method using two different sequencing technologies: short-read sequencing (Illumina MiSeq) and single molecule, real-time sequencing (PacBio RS). Conventional pulldown protocols for targeted sequencing have not been designed for single molecule, real-time sequencing at the time, thus in Chapter 3, I provide some details of the optimisation work required to adapt the targeted method for PacBio sequencing. I then assess the performance of the method for both Illumina and PacBio sequencing. In Chapter 4, I apply the targeted sequencing method described in Chapter 3 to test genetic variants in and around IFITM1, IFITM2 and IFITM3 for association with rapid disease progression in HIV. I also explore the contribution of rare genetic variants (MAF < 1%) to this phenotype by testing for a differential enrichment between cases and controls across each of the three genes. Studies in vitro have also reported that IFITM proteins are potent restrictors of dengue virus infection. In Chapter 5, I use genotype data across a cohort of 2,008 Vietnamese children diagnosed with dengue haemorrhagic fever (DHF) and 2,018 cord blood controls to test if common variants are associated with the disease.Wellcome Trus

Impact of transient down-regulation of DREAM in human embryonic stem cell pluripotency: The role of DREAM in the maintenance of hESCs

Little is knownabout the functions of downstreamregulatory element antagonist modulator (DREAM) inembryonic stem cells (ESCs). However, DREAM interacts with cAMP response element-binding protein (CREB) in a Ca2+-dependent manner, preventing CREB binding protein (CBP) recruitment. Furthermore, CREB and CBP are involved in maintaining ESC self-renewal and pluripotency. However, a previous knockout study revealed the protective function of DREAMdepletion in brain aging degeneration and that aging is accompanied by a progressive decline in stem cells (SCs) function. Interestingly, we found that DREAM is expressed in different cell types, including human ESCs (hESCs), human adipose-derived stromal cells (hASCs), human bone marrow-derived stromal cells (hBMSCs), and human newborn foreskin fibroblasts (hFFs), and that transitory inhibition of DREAMin hESCs reduces their pluripotency, increasing differentiation.We stipulate that these changes are partly mediated by increased CREB transcriptional activity. Overall, our data indicates that DREAMacts in the regulation of hESC pluripotency and could be a target to promote or prevent differentiation in embryonic cells.Junta de Andalucía, Consejería de Innovación Ciencia y Empresa, FEDER CTS-6505; INP-2011- 1615-900000; P10-CVI-6095Instituto de Salud Carlos III, FEDER RD12/0019/0028; PI10/00964; PI14/0101

Anti-obesity sodium tungstate treatment triggers axonal and glial plasticity in hypothalamic feeding centers

This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.[Objective]: This study aims at exploring the effects of sodium tungstate treatment on hypothalamic plasticity, which is known to have an important role in the control of energy metabolism. [Methods]: Adult lean and high-fat diet-induced obese mice were orally treated with sodium tungstate. Arcuate and paraventricular nuclei and lateral hypothalamus were separated and subjected to proteomic analysis by DIGE and mass spectrometry. Immunohistochemistry and in vivo magnetic resonance imaging were also performed. [Results]: Sodium tungstate treatment reduced body weight gain, food intake, and blood glucose and triglyceride levels. These effects were associated with transcriptional and functional changes in the hypothalamus. Proteomic analysis revealed that sodium tungstate modified the expression levels of proteins involved in cell morphology, axonal growth, and tissue remodeling, such as actin, CRMP2 and neurofilaments, and of proteins related to energy metabolism. Moreover, immunohistochemistry studies confirmed results for some targets and further revealed tungstate-dependent regulation of SNAP25 and HPC-1 proteins, suggesting an effect on synaptogenesis as well. Functional test for cell activity based on c-fos-positive cell counting also suggested that sodium tungstate modified hypothalamic basal activity. Finally, in vivo magnetic resonance imaging showed that tungstate treatment can affect neuronal organization in the hypothalamus. [Conclusions]: Altogether, these results suggest that sodium tungstate regulates proteins involved in axonal and glial plasticity. The fact that sodium tungstate could modulate hypothalamic plasticity and networks in adulthood makes it a possible and interesting therapeutic strategy not only for obesity management, but also for other neurodegenerative illnesses like Alzheimer's disease. © 2012 Amigó-Correig et al.This work was supported by project no SAF 2006-07382 and grant no BES-2007-17284, both awarded by the Spanish Ministry of Education of Science, and by project noCP07/00152, financed by the Carlos III Health Institute (ISCIII). Centro de Investigacion Biomedica en Red de Diabetes y Enfermedades Metabolicas is an initiative of ISCIII (Ministerio de Ciencia e Innovacion).Peer Reviewe