Interdependence between training and magnetization reversal in granular Co-CoO exchange bias systems

Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).-- et al.The interdependence between training and magnetization reversal in granular Co-CoO exchange bias (EB) systems prepared by O ion implantation in Co thin films is demonstrated by polarized neutron reflectometry. While high-fluence O-implanted thin films show reduced relative training values and no asymmetry in magnetization reversal (all reversals take place by domain wall nucleation and motion), low-fluence O ion implantation results in an increased relative training and a magnetization reversal asymmetry between the first descending and the first ascending branches. Whereas the untrained decreasing field reversal occurs mainly by domain wall nucleation and motion, traces of a domain rotation contribution are evidenced in the increasing field reversal. This is explained by the evolution of the CoO structure and the contribution of the out-of-plane magnetization with ion implantation. The amount of incorporated O, which determines the threshold between both behaviors, is around 20 at.%. This reveals that the interdependence between training and magnetization reversal is insensitive to the morphology of the constituents (i.e., granular or layered), indicating that this is an intrinsic EB effect, which can be conveniently tailored by the interplay between the intrinsic properties of the investigated materials and ion implantation.This work was financed by the Research Foundation - Flanders (FWO), the KU Leuven Concerted Action (GOA/09/006 and GOA/14/007) programs, the 2009-SGR-1292 project of the Generalitat de Catalunya, the MAT2010-20616-C02 project of the Spanish Ministerio de Economía y Competitividad, and the European Commission under the 7th Framework Programme through the “Research Infrastructure” action of the “Capacities” Programme, NMI3-II Grant No. 283883. We thank HZB (Proposal No. PHY-04-2130) and ESRF (Proposal No. HC-1012, BM20 beamline) for the allocation of neutron and synchrotron radiation beamtime, respectively, and C. Bähtz for the assistance during the synchrotron measurements. E.M. and L.M.C.P. also thank the FWO for financial support. T.D. thanks the CNPq agency (Project No. 245897/2012-7) for financial support.Peer Reviewe

Multiple particle tracking analysis in isolated nuclei reveals the mechanical phenotype of leukemia cells.

The nucleus is fundamentally composed by lamina and nuclear membranes that enclose the chromatin, nucleoskeletal components and suspending nucleoplasm. The functional connections of this network integrate external stimuli into cell signals, including physical forces to mechanical responses of the nucleus. Canonically, the morphological characteristics of the nucleus, as shape and size, have served for pathologists to stratify and diagnose cancer patients; however, novel biophysical techniques must exploit physical parameters to improve cancer diagnosis. By using multiple particle tracking (MPT) technique on chromatin granules, we designed a SURF (Speeded Up Robust Features)-based algorithm to study the mechanical properties of isolated nuclei and in living cells. We have determined the apparent shear stiffness, viscosity and optical density of the nucleus, and how the chromatin structure influences on these biophysical values. Moreover, we used our MPT-SURF analysis to study the apparent mechanical properties of isolated nuclei from patients of acute lymphoblastic leukemia. We found that leukemia cells exhibited mechanical differences compared to normal lymphocytes. Interestingly, isolated nuclei from high-risk leukemia cells showed increased viscosity than their counterparts from normal lymphocytes, whilst nuclei from relapsed-patient's cells presented higher density than those from normal lymphocytes or standard- and high-risk leukemia cells. Taken together, here we presented how MPT-SURF analysis of nuclear chromatin granules defines nuclear mechanical phenotypic features, which might be clinically relevant.post-print1994 K

Nurse species could facilitate the recruitment of mangrove seedlings after hydrological rehabilitation

Changes in hydrology are one of the main causes of mangrove degradation; however, the reforestation of mangrove has been the main restoration activity and very little information on how pioneer species can facilitate the colonization and development of the mangrove species is available. After carrying out a water reconnection as the sole restoration action, secondary succession has occurred in the mangrove rehabilitation area of Celestun (Yucatan, SE Mexico). Two pioneer species, Batis maritima and Salicornia virginica were observed in plots with different coverage (0%, 20%, 100%) where the three natural mangrove species were established, with Laguncularia racemosa as the dominant species in density. The greatest interstitial mean salinity (79.9 g/kg) was recorded in the plots with 20% cover, while the lowest salinity (40.7 g/kg) was recorded in the plots with 100% of coverage. At the end of sampling period nutrient content (carbon, nitrogen and phosphorus) and organic matter in the sediment were greatest in the plots with 100% cover, whereas the lowest concentrations were observed in the site devoid of vegetation. The percentage cover of S. virginica and B. maritima changed over time; in the plot that started with 100% cover it decreased until it disappeared at the end of the study period, whereas it increased in the plots with 20% and 0% cover. This study shows that B. maritima and S. virginica has a function as "facilitator species" initially colonizing the bare soil and modifying its conditions (decreasing interstitial salinity and increasing nutrient), which favored colonization and growing of mangrove seedlings

Accelerated iterative image reconstruction for cone-beam computed tomography through Big Data frameworks

One of the latest trends in Computed Tomography (CT) is the reduction of the radiation dose delivered to patients through the decrease of the amount of acquired data. This reduction results in artifacts in the final images if conventional reconstruction methods are used, making it advisable to employ iterative algorithms to enhance image quality. Most approaches are built around two main operators, backprojection and projection, which are computationally expensive. In this work, we present an implementation of those operators for iterative reconstruction methods exploiting the Big Data paradigm. We define an architecture based on Apache Spark that supports both Graphical Processing Units (GPU) and CPU-based architectures. The aforementioned are parallelized using a partitioning scheme based on the division of the volume and irregular data structures in order to reduce the cost of communication and computation of the final images. Our solution accelerates the execution of the two most computational expensive components with Apache Spark, improving the programming experience of new iterative reconstruction algorithms and the maintainability of the source code increasing the level of abstraction for non-experienced high performance programmers. Through an experimental evaluation, we show that we can obtain results up to 10 faster for projection and 21 faster for backprojection when using a GPU-based cluster compared to a traditional multi-core version. Although a linear speed up was not reached, the proposed approach can be a good alternative for porting previous medical image reconstruction applications already implemented in C/C++ or even with CUDA or OpenCL programming models. Our solution enables the automatic detection of the GPU devices and execution on CPU and GPU tasks at the same time under the same system, using all the available resources.This work was supported by the NIH, United States under Grant R01-HL-098686 and Grant U01 EB018753, the Spanish Ministerio de Economia y Competitividad (projects TEC2013-47270-R, RTC-2014-3028 and TIN2016-79637-P), the Spanish Ministerio de Educacion (grant FPU14/03875), the Spanish Ministerio de Ciencia, Innovacion y Universidades (Instituto de Salud Carlos III, project DTS17/00122; Agencia Estatal de Investigacion, project DPI2016-79075-R-AEI/FEDER, UE), co-funded by European Regional Development Fund (ERDF), ‘‘A way of making Europe’’. The CNIC is supported by the Ministerio de Ciencia, Spain, Innovacion y Universidades, Spain and the Pro CNIC Foundation, Spain, and is a Severo Ochoa Center of Excellence, Spain (SEV-2015-0505). Finally, this research was partially supported by Madrid regional Government, Spain under the grant ’’Convergencia Big data-Hpc: de los sensores a las Aplicaciones. (CABAHLA-CM)’’. Ref: S2018/TCS-4423

Sedimen Larut Dalam Asam Dan Tidak Larut Dalam Asam Di Perairan Teluk Buyat Dan Sekitarnya

Information on water conditions, such as sedimentation, physical factors, and coral reef ecosystem, needs to be understood that the stakeholders could optimally utilize the the area. This study was aimed at determining the sediment content of Buyat Bay and its surroundings dissolved and undissolved in the acid solution. Results found that the terrestrial sediments (Lithogenous) were not soluble in the acid solution and the marine ones (Biogenous) were soluble

Moulding hydrodynamic 2D-crystals upon parametric Faraday waves in shear-functionalized water surfaces.

Faraday waves, or surface waves oscillating at half of the natural frequency when a liquid is vertically vibrated, are archetypes of ordering transitions on liquid surfaces. Although unbounded Faraday waves patterns sustained upon bulk frictional stresses have been reported in highly viscous fluids, the role of surface rigidity has not been investigated so far. Here, we demonstrate that dynamically frozen Faraday waves—that we call 2D-hydrodynamic crystals—do appear as ordered patterns of nonlinear gravity-capillary modes in water surfaces functionalized with soluble (bio)surfactants endowing in-plane shear stiffness. The phase coherence in conjunction with the increased surface rigidity bears the Faraday waves ordering transition, upon which the hydrodynamic crystals were reversibly molded under parametric control of their degree of order, unit cell size and symmetry. The hydrodynamic crystals here discovered could be exploited in touchless strategies of soft matter and biological scaffolding ameliorated under external control of Faraday waves coherence.post-print3461 K

Effect of Standing Waves in Signal to Noise Ratio Measurement

Procedings of the International Symposium on Computer and Communication Systems for Image Guided Diagnosis and Therapy, Paris, France, June 26-29, 1996Publicad

Predicción económica regional: experiencias en la red Hispalink

La elaboración de predicciones de crecimiento sectorial regional es el principal objetivo de la red Hispalink desde hace más de dos décadas. En este trabajo, realizado en colaboración, se combinan las aportaciones de varios equipos regionales y el equipo central para describir el método de trabajo y algunas de nuestras experiencias en el ámbito de Hispalink

Optimization of Fast Spin Echo Studies b y Software Simulation

Procedings of the International Symposium on Computer and Communication Systems for Image Guided Diagnosis and Therapy, Paris, France, June 26-29, 1996Publicad