Consistent performance measurement of a system to detect masses in mammograms based on blind feature extraction

BACKGROUND: Breast cancer continues to be a leading cause of cancer deaths among women, especially in Western countries. In the last two decades, many methods have been proposed to achieve a robust mammography‐based computer aided detection (CAD) system. A CAD system should provide high performance over time and in different clinical situations. I.e., the system should be adaptable to different clinical situations and should provide consistent performance. METHODS: We tested our system seeking a measure of the guarantee of its consistent performance. The method is based on blind feature extraction by independent component analysis (ICA) and classification by neural networks (NN) or SVM classifiers. The test mammograms were from the Digital Database for Screening Mammography (DDSM). This database was constructed collaboratively by four institutions over more than 10 years. We took advantage of this to train our system using the mammograms from each institution separately, and then testing it on the remaining mammograms. We performed another experiment to compare the results and thus obtain the measure sought. This experiment consists in to form the learning sets with all available prototypes regardless of the institution in which them were generated, obtaining in that way the overall results. RESULTS: The smallest variation from comparing the results of the testing set in each experiment (performed by training the system using the mammograms from one institution and testing with the remaining) with those of the overall result, considering the success rate for an intermediate decision maker threshold, was roughly 5%, and the largest variation was roughly 17%. But, if we considere the area under ROC curve, the smallest variation was close to 4%, and the largest variation was about a 6%. CONCLUSIONS: Considering the heterogeneity in the datasets used to train and test our system in each case, we think that the variation of performance obtained when the results are compared with the overall results is acceptable in both cases, for NN and SVM classifiers. The present method is therefore very general in that it is able to adapt to different clinical situations and provide consistent performance

Independent Component Analysis to Detect Clustered Microcalcification Breast Cancers

The presence of clustered microcalcifications is one of the earliest signs in breast cancer detection. Although there exist many studies broaching this problem, most of them are nonreproducible due to the use of proprietary image datasets. We use a known subset of the currently largest publicly available mammography database, the Digital Database for Screening Mammography (DDSM), to develop a computer-aided detection system that outperforms the current reproducible studies on the same mammogram set. This proposal is mainly based on the use of extracted image features obtained by independent component analysis, but we also study the inclusion of the patient's age as a nonimage feature which requires no human expertise. Our system achieves an average of 2.55 false positives per image at a sensitivity of 81.8% and 4.45 at a sensitivity of 91.8% in diagnosing the BCRP_CALC_1 subset of DDSM

Climatic vulnerabilities and ecological preferences of soil invertebrates across biomes.

Unlike plants and vertebrates, the ecological preferences, and potential vulnerabilities of soil invertebrates to environmental change, remain poorly understood in terrestrial ecosystems globally. We conducted a cross-biome survey including 83 locations across six continents to advance our understanding of the ecological preferences and vulnerabilities of the diversity of dominant and functionally important soil invertebrate taxa, including nematodes, arachnids and rotifers. The diversity of invertebrates was analyzed through amplicon sequencing. Vegetation and climate drove the diversity and dominant taxa of soil invertebrates. Our results suggest that declines in forest cover and plant diversity, and reductions in plant production associated with increases in aridity, can result in reductions of the diversity of soil invertebrates in a drier and more managed world. We further developed global atlases of the diversity of these important soil invertebrates, which were cross-validated using an independent database. Our study advances the current knowledge of the ecological preferences and vulnerabilities of the diversity and presence of functionally important soil invertebrates in soils from across the globe. This information is fundamental for improving and prioritizing conservation efforts of soil genetic resources and management policies

A first experimental evidence by transmission electron microscopy of dislocation disociation in the TeO2 system

En este trabajo se pretende analizar la microestructura de monocristales de TeO2 (paratelurita) deformados plásticamente en compresión uniaxial a alta temperatura (∼870 K) en distintas condiciones. Para ello, se han ensayado muestras con orientación cristalográfica [110], y se han cortado láminas correspondientes a los planos de deslizamiento para ser observadas con microscopía electrónica de transmisión. El estudio de la subestructura de dislocaciones en este material es complejo debido a su alta anisotropía. La observación de dicha microestructura ha puesto de manifiesto la presencia de disociación de dislocaciones. Es la primera vez que se encuentra este fenómeno en la paratelurita. De la distancia de equilibrio entre dislocaciones parciales, se ha podido obtener una estimación de la energía de falta de apilamiento en este sistema.This work intends to analyse the microstructure of paratellurite (TeO2 single crystals) plastically deformed at high temperature ∼870 K) in uniaxial compression along [110]. Samples have been mechanically tested, and thin foils have been cut from them, corresponding to the slip systems to be observed in transmission electron microscopy. The study of the dislocation substructure in this material is rather complex due to its high anisotropy. Microstructural observation by TEM has put into evidence the presence of dislocation dissociation. This is the first work reporting this fact. From the equilibrium distance between partials, an estimation of the stacking fault energy has been carried out

Long range effects on the optical model of 6He around the Coulomb barrier

El pdf del artículo es la versión pre-print: arXiv:1004.1911v1We present an optical model (OM) analysis of the elastic scattering data of the reactions 6He+27Al and 6He+208Pb at incident energies around the Coulomb barrier. The bare part of the optical potential is constructed microscopically by means of a double folding procedure, using the São Paulo prescription without any renormalization. This bare interaction is supplemented with a Coulomb dipole polarization (CDP) potential, which takes into account the effect of the dipole Coulomb interaction. For this CDP potential, we use an analytical formula derived from the semiclassical theory of Coulomb excitation. The rest of the optical potential is parametrized in terms of Woods-Saxon shapes. In the 6He+208Pb case, the analysis confirms the presence of long range components, in agreement with previous works. Four-body Continuum-Discretized Coupled-Channels calculations have been performed in order to better understand the features of the optical potentials found in the OM analysis. This study searches to elucidate some aspects of the optical potential of weakly bound systems, such as the dispersion relation and the long range (attractive and absorptive) mechanisms. © 2010 Elsevier B.V.This work has been supported by the Spanish Ministerio de Ciencia e Innovación under project FPA2006-13807-C02-01, the local government of Junta de Andalucía under the excellence project P07-FQM-02894 and the Spanish Consolider-Ingenio 2010 Programme CPAN (CSD2007-00042).Peer Reviewe

Meconio y exposición prenatal a neurotóxicos

6 pages, 1 figures, 2 tables.[ESP] Introducción. La ubicuidad con la que se encuentran la mayoría de las substancias neurotóxicas en el medio ambiente implica a los pediatras en la necesidad de desarrollar métodos para medir la magnitud de la exposición durante los periodos vulnerables del desarrollo. Una forma útil de abordar este problema consiste en analizar muestras biológicas que acumulen las substancias neurotóxicas o sus metabolitos durante el periodo fetal.Método. Revisión bibliográfica sistemática de los últimos 20 años obtenida principalmente de Medline; Science Citation Index y Embase sobre los estudios con meconio como matriz de exposición prenatal a substancias neurotóxicas. El perfil de búsqueda utilizado fue: meconium, prenatal exposure, biological markers, matrices, environmental pollutants, nervous system poisonings, neurotoxicity sindromes. Hemos seleccionado los trabajos más importantes y de sus referencias se han obtenido los más relevantes de los años previos a la búsqueda.Resultados. Tradicionalmente, los esfuerzos para determinar la exposición fetal se han centrado en el análisis de sangre de cordón u orina de la madre o el neonato. El meconio es fácilmente disponible, es inerte, acumula los neurotóxicos y/o sus metabolitos desde la semana 12 de gestación donde quedan “fosilizados” hasta el nacimiento. Puede constituir un instrumento muy importante para investigar la exposición fetal a los distintos contaminantes ambientales y en particular a neurotóxicos.Conclusiones. Las exposiciones fetales a los distintos neurotóxicos estudiados a través de sangre materna, de cordón, pelo, uña, placenta y orina parecen ser menos predictivas sobre los efectos neurológicos que las mediciones de los mismos realizadas en meconio. Son necesarios más estudios en este campo.Implementar y desarrollar la medida en meconio de una amplia gama de sustancias neurotóxicas ayudará en la práctica pediátrica a una intervención e identificación temprana mostrando las exposiciones que puedan provocar daño y facilitando el desarrollo de medidas preventivas y rehabilitadoras.[ENG] Brackground. The environmental ubiquity of most neurotoxicants implies the pediatricians in the development of methods for exposure measurement during the vulnerable periods of development. The analysis of biological samples able to accumulate the neurotoxicant substances or its metabolites during the fetal period is a useful approach to fulfil this objective.Material and methods. A systematic literature review of the last 20 years in Medline, Science Citation Index and Embase on the studies with meconium like womb of prenatal exposure to neurotoxicants has been undertaken. The search profile was: “meconium”, “prenatal exposure”, “biological markers”, “matrices”, “environmental pollutants”, “nervous system poisonings”, “neurotoxicity sindromes”. We selected the most relevant articles and retrieved more from their references.Results. Traditionally, the efforts to determine the fetal exposure have been centered in the analysis of cord blood, urinates of the mother or of the neonato. Meconium is easily available, inert, accumulates the neurotoxicants and/or its metabolitos from week 12 of gestation where they are "fossilized" until the birth. It can constitute a very important instrument for the investigation of the fetal exposure to the different environmental pollutants and in particular to neurotoxicants.Conclusions. Foetal exposure to different neurotoxicants monitored from maternal blood, cord blood, hair, fingernail, placenta and urinates seem to be less predictive for neurological effects than meconium. However, more studies are needed to confirm this hypothesis.Implementation and measurement in meconium of a wide range of neurotoxic substances will be of help in the pediatric practice for intervention and early identification as it will reveal harmful exposures and facilitate the implementation of preventive measures.Los autores quieren expresar su agradecimiento a los miembros de la red de Investigación Colaborativa INMA, y en especial a Amparo Quiles Latorre, Elena Romero Aliaga y Sandra Pérez Aliaga, por su apoyo y colaboración en la realización del trabajo de campo; al equipo de enfermería de la 7ª, 8ª y 9ª de la maternidad del Hospital Materno-Infantil Universitario La Fe y a los recién nacidos y sus felices padres que con su colaboración y entusiasmo hacen posible llevar a término estos estudios.Peer reviewe

Efectos de la existencia de capa elástica en los sistemas de césped artificial de tercera generación y la velocidad de carrera sobre la respuesta biomecánica de atenuación de impactos en jugadores de fútbol

Accésit Congreso SIBB 2015El objetivo del estudio fue comparar la influencia de la capa elástica con otros componentes estructurales sobre la magnitud y atenuación de impactos en diferentes sistemas de césped artificial (SCA) de tercera generación. Para ello, 12 participantes fueron evaluados sobre cuatro SCA, con características estructurales diferentes, mediante un test lineal de carrera a tres velocidades distintas (V1: 3,33 m/s, V2: 4 m/s y V3: velocidad máxima) con dos acelerómetros triaxiales situados en tibia y cabeza. El pico de aceleración en tibia fue significativamente menor en SCA4 (sub-base de terreno natural, mayor longitud de fibra y cantidad de relleno) a V3 y menor que SCA1 (fibra de menor longitud y menor cantidad de relleno) y SCA3 (mayor longitud de la fibra, mayor cantidad de relleno y sub-base asfáltica) a V1 y V2. Mientras SCA3, presentó una mayor atenuación con respecto a SCA1 y SCA2 (características estructurales similares a SCA1 y con capa elástica) a V1 y con SCA2 a V2. La capa elástica puede tener una influencia menor que la longitud de la fibra, la cantidad de relleno y la sub-base en la magnitud de los picos de impacto a velocidades máximas y en su capacidad de atenuación a velocidades lentas y moderadas.Peer ReviewedAward-winnin

Luxación carpometacarpiana del primer dedo asociada a fractura de trapecio

Presentamos un caso de luxación carpometacarpiana del primer dedo asociada a fractura de trapecio. Fue tratada mediante reducción abierta y fijación interna. El resultado obtenido después de un año de seguimiento fue excelente. Sólo hemos encontrado once casos en la literatura y ninguno tratado como el nuestro.A case of carpometacarpal dislocation of the thumb associated with fracture of the trapezium in presented. It was treated by open reduction and internal fixation. The result after a one year follow-up was excellent. We have found only eleven cases in literature and none was treated like ours

Reading virtual slide using web viewers: results of subjective experience with three different solutions

<p>Abstract</p> <p>Background</p> <p>Virtual slides are viewed using interactive software that enables the user to simulate the behaviour of a conventional optical microscope, like adjusting magnifications and navigating to any portion of the image. Nowadays, information about the performance and features of web-based solutions for reading slides in real environments is still scarce. The objective of this study is analyzing the subjective experience of pathologists with virtual slides, comparing the time needed to read slides using different web viewers and different network connections.</p> <p>Methods</p> <p>Eight slides were randomly selected (4 biopsies and 2 cytologies) from Hospital General de Ciudad Real (HGCR) archives. Three different virtual slide web-viewing solutions were analyzed: Aperio web server, Olympus NetImage Server, and Aurora mScope. Five pathologists studied to time needed to access images of each virtual slide, selecting a panoramic view, 10 low magnification fields, and 20 high magnification fields.</p> <p>Results</p> <p>Aperio viewer is very efficient in overview images. Aurora viewer is especially efficient in lower magnifications (10×). For larger magnifications (20× and 40×) no significant differences were found between different vendors. Olympus was found to be the most user-friendly interface. When comparing Internet with intranet connections, despite being slower, users also felt comfortable using virtual slides through Internet connection.</p> <p>Conclusion</p> <p>Available web solutions for virtual slides have different advantages, mainly in functionalities and optimization for different magnifications. Pathologist should select the solutions adapted to their needs.</p