IRAS06562-0337, the Iron-clad Nebula: a young star embedded in a molecular cloud

Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe

Un equipo para medir el tamaño de frutas y hortalizas

En la presente nota resumimos el funcionamiento y algunos resultados obtenidos con un equipo para la medición del tamaño -y bajo ciertas circunstancias de la forma- de productos de forma irregular como frutas y hortalizas, con el que hemos trabajado en los últimos años en el Laboratorio de Propiedades Físicas y Técnicas Avanzadas en Agroalirnentación (grupo de investigación de la Universidad Politécnica de Madrid)

A study on multi-scale kernel optimisation via centered kernel-target alignment

Kernel mapping is one of the most widespread approaches to intrinsically deriving nonlinear classifiers. With the aim of better suiting a given dataset, different kernels have been proposed and different bounds and methodologies have been studied to optimise them. We focus on the optimisation of a multi-scale kernel, where a different width is chosen for each feature. This idea has been barely studied in the literature, although it has been shown to achieve better performance in the presence of heterogeneous attributes. The large number of parameters in multi-scale kernels makes it computationally unaffordable to optimise them by applying traditional cross-validation. Instead, an analytical measure known as centered kernel-target alignment (CKTA) can be used to align the kernel to the so-called ideal kernel matrix. This paper analyses and compares this and other alternatives, providing a review of the literature in kernel optimisation and some insights into the usefulness of multi-scale kernel optimisation via CKTA. When applied to the binary support vector machine paradigm (SVM), the results using 24 datasets show that CKTA with a multi-scale kernel leads to the construction of a well-defined feature space and simpler SVM models, provides an implicit filtering of non-informative features and achieves robust and comparable performance to other methods even when using random initialisations. Finally, we derive some considerations about when a multi-scale approach could be, in general, useful and propose a distance-based initialisation technique for the gradient-ascent method, which shows promising results

An Iterated Greedy Algorithm for Improving the Generation of Synthetic Patterns in Imbalanced Learning

Real-world classification datasets often present a skewed distribution of patterns, where one or more classes are under-represented with respect to the rest. One of the most successful approaches for alleviating this problem is the generation of synthetic minority samples by convex combination of available ones. Within this framework, adaptive synthetic (ADASYN) sampling is a relatively new method which imposes weights on minority examples according to their learning complexity, in such a way that difficult examples are more prone to be oversampled. This paper proposes an improvement of the ADASYN method, where the learning complexity of these patterns is also used to decide which sample of the neighbourhood is selected. Moreover, to avoid suboptimal results when performing the random convex combination, this paper explores the application of an iterative greedy algorithm which refines the synthetic patterns by repeatedly replacing a part of them. For the experiments, six binary datasets and four over-sampling methods are considered. The results show that the new version of ADASYN leads to more robust results and that the application of the iterative greedy metaheuristic significantly improves the quality of the generated patterns, presenting a positive effect on the final classification model

Partial order label decomposition approaches for melanoma diagnosis

Melanoma is a type of cancer that develops from the pigment-containing cells known as melanocytes. Usually occurring on the skin, early detection and diagnosis is strongly related to survival rates. Melanoma recognition is a challenging task that nowadays is performed by well trained dermatologists who may produce varying diagnosis due to the task complexity. This motivates the development of automated diagnosis tools, in spite of the inherent difficulties (intra-class variation, visual similarity between melanoma and non-melanoma lesions, among others). In the present work, we propose a system combining image analysis and machine learning to detect melanoma presence and severity. The severity is assessed in terms of melanoma thickness, which is measured by the Breslow index. Previous works mainly focus on the binary problem of detecting the presence of the melanoma. However, the system proposed in this paper goes a step further by also considering the stage of the lesion in the classification task. To do so, we extract 100 features that consider the shape, colour, pigment network and texture of the benign and malignant lesions. The problem is tackled as a five-class classification problem, where the first class represents benign lesions, and the remaining four classes represent the different stages of the melanoma (via the Breslow index). Based on the problem definition, we identify the learning setting as a partial order problem, in which the patterns belonging to the different melanoma stages present an order relationship, but where there is no order arrangement with respect to the benign lesions. Under this assumption about the class topology, we design several proposals to exploit this structure and improve data preprocessing. In this sense, we experimentally demonstrate that those proposals exploiting the partial order assumption achieve better performance than 12 baseline nominal and ordinal classifiers (including a deep learning model) which do not consider this partial order. To deal with class imbalance, we additionally propose specific over-sampling techniques that consider the structure of the problem for the creation of synthetic patterns. The experimental study is carried out with clinician-curated images from the Interactive Atlas of Dermoscopy, which eases reproducibility of experiments. Concerning the results obtained, in spite of having augmented the complexity of the classification problem with more classes, the performance of our proposals in the binary problem is similar to the one reported in the literature

Perinatal asphyxia: CNS development and deficits with delayed onset

Perinatal asphyxia constitutes a prototype of obstetric complications occurring when pulmonary oxygenation is delayed or interrupted. The primary insult relates to the duration of the period lacking oxygenation, leading to death if not re-established. Re-oxygenation leads to a secondary insult, related to a cascade of biochemical events required for restoring proper function. Perinatal asphyxia interferes with neonatal development, resulting in long-term deficits associated to mental and neurological diseases with delayed clinical onset, by mechanisms not yet clarified. In the experimental scenario, the effects observed long after perinatal asphyxia have been explained by over expression of sentinel proteins, such as poly(ADP-ribose) polymerase-1 (PARP-1), competing for NAD+ during re-oxygenation, leading to the idea that sentinel protein inhibition constitutes a suitable therapeutic strategy. Asphyxia induces transcriptional activation of proinflammatory factors, in tandem with PARP-1 overactivation, and pharmacologically induced PARP-1 inhibition also down-regulates the expression of proinflammatory cytokines. Nicotinamide has been proposed as a suitable PARP-1 inhibitor. Its effect has been studied in an experimental model of global hypoxia in rats. In that model, the insult is induced by immersing rat foetuses into a water bath for various periods of time. Following asphyxia, the pups are delivered, treated, and nursed by surrogate dams, pending further experiments. Nicotinamide rapidly distributes into the brain following systemic administration, reaching steady state concentrations sufficient to inhibit PARP-1 activity for several hours, preventing several of the long-term consequences of perinatal asphyxia, supporting the idea that it constitutes a lead for exploring compounds with similar or better pharmacological profiles

Hospital Virtual: Sistema de información clínica y telecuidado de pacientes VIH/SIDA basado en tecnologías Web 2.0

Este artículo describe el desarrollo de un nuevo sistema de información clínica y telecuidado de pacientes VIH/SIDA que se encuentra implantado en rutina clínica dentro del Servicio de Enfermedades Infecciosas del Hospital Clínic de Barcelona. El proyecto surge ante la necesidad de unificar el sistema de información departamental del servicio y un sistema de telemedicina instalado en el hospital en 2004. Para ello se han diseñado e implementado nuevas bases de datos y dos sistemas específicos para uso de profesionales y pacientes. Además, se ha realizado una integración con el Sistema de Información del Hospital (HIS) permitiendo el acceso a todos los datos requeridos de los pacientes desde una única aplicación. Este nuevo sistema está al servicio de más de 70 profesionales sanitarios que realizan una media de 150 consultas al día disponiendo de información clínica de más de 8000 pacientes

Observations of the Cosmic Microwave Background and Galactic Foregrounds at 12-17 GHz with the COSMOSOMAS Experiment

(Abridged) We present the analysis of the first 18 months of data obtained with the COSMOSOMAS experiment at the Teide Observatory (Tenerife). Three maps have been obtained at 12.7, 14.7 and 16.3 GHz covering 9000 square degrees each with a resolution of ~1 degree and with sensitivities 49, 59 and 115 muK per beam respectively. These data in conjuction with the WMAP first year maps have revealed that the Cosmic Microwave Background (CMB) is the dominant astronomical signal at high galatic latitude in the three COSMOSOMAS channels with an average amplitude of 29.7+/- 1.0 \muK (68% c.l. not including calibration errors). This value is in agreement with the predicted CMB signal in the COSMOSOMAS maps using the best fit Lambda-CDM model to the WMAP power spectrum. Cross-correlation of COSMOSOMAS data with the DIRBE map at 100 \mu m shows the existence of a common signal with amplitude 7.4+/- 1.1, 7.5+/- 1.1, and 6.5+/-2.3 muK in the 12.7, 14.7 and 16.3 GHz COSMOSOMAS maps at |b|>30^\deg. Using the WMAP data we find this DIRBE correlated signal rises from high to low frequencies flattening below ~20 GHz. At higher galactic latitudes the average amplitude of the correlated signal with the DIRBE maps decreases slightly. The frequency behaviour of the COSMOSOMAS/WMAP correlated signal with DIRBE is not compatible with the expected tendency for thermal dust. A study of the H-alpha emission maps do not support free-free as a major contributor to that signal. Our results provide evidence of a new galactic foreground with properties compatible with those predicted by the spinning dust models.Comment: 11 pages, 21 figures. Submitted to MNRAS. For paper with figures at full resolution, see http://www.iac.es/project/cmb/cosmosomas

Assessment of the toll-like receptor 4 Asp299Gly, Thr399Ile and interleukin-8 -251 polymorphisms in the risk for the development of distal gastric cancer

<p>Abstract</p> <p>Background</p> <p>The intensity of the inflammation induced by <it>Helicobacter pylori </it>colonization is associated with the development of distal gastric cancer (GC). The host response to <it>H</it>. <it>pylori </it>has been related to genetic polymorphisms that influence both innate and adaptive immune responses.</p> <p>Our aim was to investigate whether the presence of the <it>TLR4 Asp299Gly</it>, <it>TLR4 Thr399Ile </it>and <it>IL-8-251 </it>A/T polymorphisms had any influence in the development of distal GC in a Mexican population.</p> <p>Methods</p> <p>We studied 337 patients that were divided in two groups: 78 patients with histologically confirmed distal GC and 259 non-cancer controls. The presence of <it>H. pylori </it>in the control population was defined by positive results of at least two of four diagnostic tests: serology, histology, rapid urease test and culture. Human DNA was purified and genotyped for <it>TLR4 Asp299Gly </it>polymorphism by pyrosequencing, for <it>TLR4 Thr399Ile </it>by PCR-RFLP and for <it>IL8-251 </it>by the amplification refractory mutation system (ARMS)-PCR.</p> <p>Results</p> <p>The non-cancer control group was found to be in Hardy-Weinberg equilibrium at the polymorphic loci studied (chi-square _H-W= 0.58 for <it>IL8-251</it>, 0.42 for <it>TLR4 Asp299Gly </it>and 0.17 for <it>TLR4 Thr399Ile</it>). The frequencies of mutated alleles (homozygous plus heterozygous) were compared between cases and controls. We found no significant difference for <it>TLR4- Asp299Gly </it>[the 7.7% of distal GC patients and 7.7 % non-cancer controls (p = 0.82)] and for <it>TLR4 Thr399Ile </it>[the 1.3% of GC patients and the 5% of the control population (p = 0.2)]. In contrast, for <it>IL-8-251 </it>A/T, 80.77% of the GC patients and 66.4% in the control group age and gender matched had at least one copy of mutated allele (OR = 2.12, 95% CI = 1.1–4.2) (p = 0.023).</p> <p>Conclusion</p> <p>This study showed that the <it>IL8-251*A </it>allele could be related to the development of distal gastric cancer in this Mexican population.</p

Sex and race-ethnic disparities in door-to-CT time in acute ischemic stroke: The Florida Stroke Registry

Background Less than 40% of acute stroke patients have computed tomography (CT) imaging performed within 25 minutes of hospital arrival. We aimed to examine the race-ethnic and sex differences in door-to-CT (DTCT) ≤25 minutes in the FSR (Florida Stroke Registry). Methods and Results Data were collected from 2010 to 2018 for 63 265 patients with acute ischemic stroke from the FSR and secondary analysis was performed on 15 877 patients with intravenous tissue plasminogen activator-treated ischemic stroke. Generalized estimating equation models were used to determine predictors of DTCT ≤25. DTCT ≤25 was achieved in 56% of cases of suspected acute stroke, improving from 36% in 2010 to 72% in 2018. Women (odds ratio [OR], 0.90; 95% CI, 0.87-0.93) and Black (OR, 0.88; CI, 0.84-0.94) patients who had strokes were less likely, and Hispanic patients more likely (OR, 1.07; CI, 1.01-1.14), to achieve DTCT ≤25. In a secondary analysis among intravenous tissue plasminogen activator-treated patients, 81% of patients achieved DTCT ≤25. In this subgroup, women were less likely to receive DTCT ≤25 (0.85, 0.77-0.94) whereas no significant differences were observed by race or ethnicity. Conclusions In the FSR, there was considerable improvement in acute stroke care metric DTCT ≤25 in 2018 in comparison to 2010. However, sex and race-ethnic disparities persist and require further efforts to improve performance and reduce these disparities