Multi-modal ultrasound imaging for breast cancer detection

This work describes preliminary results of a two-modality imaging system aimed at the early detection of breast cancer. The first technique is based on compounding conventional echographic images taken at regular angular intervals around the imaged breast. The other modality obtains tomographic images of propagation velocity using the same circular geometry. For this study, a low-cost prototype has been built. It is based on a pair of opposed 128-element, 3.2 MHz array transducers that are mechanically moved around tissue mimicking phantoms. Compounded images around 360 degrees provide improved resolution, clutter reduction, artifact suppression and reinforce the visualization of internal structures. However, refraction at the skin interface must be corrected for an accurate image compounding process. This is achieved by estimation of the interface geometry followed by computing the internal ray paths. On the other hand, sound velocity tomographic images from time of flight projections have been also obtained. Two reconstruction methods, Filtered Back Projection (FBP) and 2D Ordered Subset Expectation Maximization (2D OSEM), were used as a first attempt towards tomographic reconstruction. These methods yield useable images in short computational times that can be considered as initial estimates in subsequent more complex methods of ultrasound image reconstruction. These images may be effective to differentiate malignant and benign masses and are very promising for breast cancer screening. (C) 2015 The Authors. Published by Elsevier B.V

Detección de hembras en estro en una empresa pecuaria

Data registered from January 1994 up to December 2008 were collected to evaluate estrual females detection performance at Triángulo 4 Livestock Center in Camagüey province. Seasonal and trend components from the reproduction control system were determined as well as their crossed correlations with detection of females at first estrus and total of estrus. The trend component showed a steady performance from 1994 to 2000, but it decreased from 2001 to 2008. Estrual female number increased from July to November, but dramatically diminished from December to May depending on pasture availability. Seasonal series revealed temporary dependence relations for several lags among reproductive categories, births, and estrual females detection. This evidenced the existence of aseasonal factors. Differences between temporary dependence relations and the expected ones for births and puerperal heifers related to detection of females at first estrus ranged from eight to five months. Non-pregnant and inseminated heifers were out of the expected range. This confirms organizational and control deficiencies concerning reproduction.Para evaluar el comportamiento de la recogida de hembras en estro, en la Empresa Pecuaria Triángulo 4 en la provincia de Camagüey, Cuba, se utilizaron los registros archivados por la brigada de reproducción (enero de 1994diciembre de 2008). Se determinó la tendencia y la estacionalidad de los componentes del sistema de control de la reproducción, y las correlaciones cruzadas entre estos y la recogida de hembras en primer y total de estros, apreciándose comportamiento estable en el período 1994-2000 y decreciente entre el 2001 y 2008 de la tendencia para la recogida de hembras en estro. La recogidas de hembras en estro mostró incremento en el período julio-noviembre y descenso marcado entre diciembre y mayo, asociados con la disponibilidad de los pastos. Para categorías reproductivas afines, reveló que fueron determinantes en el comportamiento reproductivo estacional evaluado. El empleo de series estacionarias permitió revelar la existencia de relaciones de dependencia temporal entre las categorías reproductivas, los nacimientos y la recogida de hembras en estro en varios retardos, lo que evidenció la presencia de otros factores independientes de la estación. Existieron diferencias de ocho y cinco meses entre las relaciones observadas y las esperadas para los nacimientos y las recentinas con relación a las hembras recogidas en el primer estro, las hembras vacías y las inseminadas estuvieron fuera del rango esperado, esto demuestra deficiencias en la organización y control de la reproducción

Perpendicular magnetic anisotropy in Nd-Co alloy films nanostructured by di-block copolymer templates

et al.Nd-Co amorphous magnetic films with perpendicular magnetic anisotropy have been grown on nanostructured templates prepared with self-organized di-block poly(styrene)-block-poly(4-vinylpyridine) copolymer layers with a periodic structure of 60 nm spaced pores. These templates modify both the magnetic film topography and mechanical strain on a local scale. The effect of these structural changes is particularly noticeable in the low thickness range of the magnetic films where the transition from in-plane to out-of plane magnetization takes place. The Nd-Co films grown on the copolymer template present lower perpendicular magnetic anisotropy and, also, stronger stripe domain pinning effects in comparison with reference films grown on flat Si substrates. © 2012 American Institute of Physics.Work supported by Spanish MEC under Grants FIS2008-06249 and Consolider CSD2007-00010 and by CAM under Grant S2009/MAT-1726.Peer Reviewe

Autocalibration with the Minimum Number of Cameras with Known Pixel Shape

In 3D reconstruction, the recovery of the calibration parameters of the cameras is paramount since it provides metric information about the observed scene, e.g., measures of angles and ratios of distances. Autocalibration enables the estimation of the camera parameters without using a calibration device, but by enforcing simple constraints on the camera parameters. In the absence of information about the internal camera parameters such as the focal length and the principal point, the knowledge of the camera pixel shape is usually the only available constraint. Given a projective reconstruction of a rigid scene, we address the problem of the autocalibration of a minimal set of cameras with known pixel shape and otherwise arbitrarily varying intrinsic and extrinsic parameters. We propose an algorithm that only requires 5 cameras (the theoretical minimum), thus halving the number of cameras required by previous algorithms based on the same constraint. To this purpose, we introduce as our basic geometric tool the six-line conic variety (SLCV), consisting in the set of planes intersecting six given lines of 3D space in points of a conic. We show that the set of solutions of the Euclidean upgrading problem for three cameras with known pixel shape can be parameterized in a computationally efficient way. This parameterization is then used to solve autocalibration from five or more cameras, reducing the three-dimensional search space to a two-dimensional one. We provide experiments with real images showing the good performance of the technique.Comment: 19 pages, 14 figures, 7 tables, J. Math. Imaging Vi

Microstructure and magnetocaloric effect of melt-spun Ni52Mn26Ga22 ribbon

"Microstructural features and magnetocaloric properties of Ni52Mn26Ga22 melt-spun ribbons were studied. Results show that there are four types of differently oriented variants of seven-layered modulated (7M) martensite at room temperature, being twin-related one another and clustered in colonies. Due to the coupled magnetic and structural transformations between parent austenite and 7M martensite, the melt-spun ribbons exhibit a significant magnetocaloric effect. At an applied magnetic field of 5 T, an absolute maximum value of the isothermal magnetic entropy change of 11.4 J kg(-1) K-1 is achieved with negligible hysteresis losses.

Directory of Atmospheric, Hydrographic and Biological datasets for the Canary Current Large Marine Ecosystem

Environmental and biological data-sets were recovered from oceanographic surveys and other observation sources (e.g. tide gauges) since the 40s. This rescue and mining exercise was carried out in cooperation with the countries bordering the CCLME and other nations undertaking research in the region (i.e. Morocco, Mauritania, Senegal, Gambia, Guinea, Guinea Bissau, Cape Verde, Spain, Norway, Germany and France). A total of 425 data-sets, 27 databases and 21 time-series sites have been identified in the area. A substantial part of them were rescued from archives supported in paper copy. Finally, a directory of meta-data referring 99 data-sets and data-bases has been published. This catalogue and the recovered data offer an exceptional opportunity for the researchers in the CCLME to study the dynamics and trends of a multiplicity of variables, and will enable them to create their own time-series, baselines and climatologies under a spatial and temporal perspective. It will produce new and valuable information on changes produced during the last 35 years in this region, going from climatic changes to shifts in species diversity and populations due to natural and human induced factors. This directory is the first result of the project “Enhancing oceanography capacities on Western Africa Countries” funded by the Spanish Agency for International Development Cooperation (AECID) and coordinated by the IOC-UNESCO and the IEO. The project aims to reinforce transboundary cooperation in the CCLME and to facilitate access and data flow to existing scientific information and its utilization by the scientists, politicians, industry and civil society.http://unesdoc.unesco.org/images/0023/002314/231430E.pd

DNA-based population density estimation of black bear at northern Mexico: A preliminary study

The analysis of deoxyribonucleic acid (DNA) microsatellites from hair samples obtained by the non-invasive method of traps was used to estimate the population density of black bears (Ursus americanus eremicus) in a mountain located at the county of Lampazos, Nuevo Leon, Mexico. The genotyping of bears was performed by multiplex polymerase chain reaction (PCR) using an average of two hairs for each animal. Samples were obtained with barbed wire placed at the traps, which contained food as bait. Multiplex PCR was performed with the GenomiPhiTM, G.E. kit and genotyping with an automated DNA sequencing machine (ABI 310 System). Allelic frequency, heterozygosis and exclusion probability of seven DNA microsatellites were calculated and analyzed with computer programs to determine the population density. Three of the microsatellites had a heterozygosis higher than 0.7 and the population density was calculated in at least 1 bear/km2.Keywords: Black bear, Ursus americanus, population size, DNA microsatellite, MexicoAfrican Journal of Biotechnology Vol. 12(2), pp. 103-10

Double percolation effects and fractal behavior in magnetic/superconducting hybrids

Perpendicular magnetic anisotropy ferromagnetic/superconducting (FM/SC) bilayers with a labyrinth domain structure are used to study nucleation of superconductivity on a fractal network, tunable through magnetic history. As clusters of reversed domains appear in the FM layer, the SC film shows a percolative behavior that depends on two independent processes: the arrangement of initial reversed domains and the fractal geometry of expanding clusters. For a full labyrinth structure, the behavior of the upper critical field is typical of confined superconductivity on a fractal network