Non-Gaussianity analysis on local morphological measures of WMAP data

The decomposition of a signal on the sphere with the steerable wavelet constructed from the second Gaussian derivative gives access to the orientation, signed-intensity, and elongation of the signal's local features. In the present work, the non-Gaussianity of the WMAP temperature data of the cosmic microwave background (CMB) is analyzed in terms of the first four moments of the statistically isotropic random fields associated with these local morphological measures, at wavelet scales corresponding to angular sizes between 27.5 arcminutes and 30 degrees on the celestial sphere. While no detection is made neither in the orientation analysis nor in the elongation analysis, a strong detection is made in the excess kurtosis of the signed-intensity of the WMAP data. The non-Gaussianity is observed with a significance level below 0.5% at a wavelet scale corresponding to an angular size around 10 degrees, and confirmed at neighbour scales. This supports a previous detection of an excess of kurtosis in the wavelet coefficient of the WMAP data with the axisymmetric Mexican hat wavelet (Vielva et al. 2004). Instrumental noise and foreground emissions are not likely to be at the origin of the excess of kurtosis. Large-scale modulations of the CMB related to some unknown systematics are rejected as possible origins of the detection. The observed non-Gaussianity may therefore probably be imputed to the CMB itself, thereby questioning the basic inflationary scenario upon which the present concordance cosmological model relies. Taking the CMB temperature angular power spectrum of the concordance cosmological model at face value, further analysis also suggests that this non-Gaussianity is not confined to the directions on the celestial sphere with an anomalous signed-intensity.Comment: 10 pages, 3 figures. Version 2 includes minor changes to match version accepted for publication in MNRA

N,N′-Bis(4-amino­benz­yl)oxalamide

In the title compound, C16H18N4O2, the two carbonyl groups are in an anti­periplanar conformation with an O=C—C=O torsion angle of 173.86 (17)°. In the crystal, a pair of inter­molecular N—H⋯O hydrogen bonds, forming an R 2 2(10) ring motif, connect the mol­ecules into an inversion dimer. The dimers are further linked by N—H⋯N and C—H⋯π inter­actions, forming a zigzag chain along the b axis

Integrated methodology for assessing the effects of geomorphological river restoration on fish habitat and riparian vegetation

Changes in the geomorphology of rivers have serious repercussions, causing losses in the dynamics and naturalness of their forms, going in many cases, from a type of meandering channel, with constant erosion and sedimentation processes, to a channelized narrow river with rigid and stable margins, where the only possibility of movement occurs in the vertical, causing the only changes in channel geometry occur in the river bed. On the other hand, these changes seriously affect the naturalness of the banks, preventing the development of riparian vegetation and reducing the cross connectivity of the riparian corridor. Common canalizations and disconnections of meanders increase the slope, and therefore speed, resulting in processes of regressive erosion, effect increased as a result of the narrowing of the channel and the concentration of flows. This process of incision may turn the flood plain to be "hung", being completely disconnected from the water table, with important consequences for vegetation. As an example of the effects of these changes, it has been chosen the case of the Arga River The Arga river has been channelized and rectified, as it passes along the meander RamalHondo and Soto Gil (Funes, Navarra). The effects on fish habitat and riparian vegetation by remeandering the Arga River are presented. and Ttwo very contrasting situationsrestoration hypothesis, in terms of geomorphology concerns, have been established to assess the effects these changes have on the habitat of one of the major fish species in the area (Luciobabus graellsii) and on the riparian vegetation. To accomplish this goal, it has been necessary to used the a digital elevation model provided by LIDAR flight, bathymetric data, flow data, as inputs, and a hydraulic simulation model 2D (Infoworks RS). The results obtained not only helped to evaluate the effects of the past alterations of geomorphologic characteristics, but also to predict fish and vegetation habitat responses to this type of changes

Performance comparison of large-area SiPM arrays suitable for gamma ray detectors

[EN] The use of photosensors of the type Silicon Photomultpliers (SiPM) has widely been extended in recent years for multiple applications in both research and industry. However, there is a lack of comparative studies of different SiPMs under the same conditions, making it difficult to choose the most appropriate one for a specific application. SiPM arrays are suitable for gamma rays detectors, especially when covering large active areas. They are used either in clinical or pre-clinical scenarios, constituting Single-Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) scanners, or just gamma cameras. The current work presents, for the first time, a comparative study between SensL, Hamamatsu Photonics and KETEK arrays of 12 x 12 SiPMs, with individual active areas of 3 mm x 3 mm, thus covering a total active area of about 5 cm x 5 cm. In this study, we have first evaluated their bias and temperature dependencies, resulting in a very similar behaviour with just a slightly larger dependency of the tested Hamamatsu parts. We also report the performance of detector blocks based on these three SiPM arrays, when coupled to pixelated crystal arrays and monolithic scintillators, in terms of photon impact estimation accuracy, as well as energy resolution. In the case of the monolithic crystals, also the depth of interaction resolution was determined. Both monolithic and pixelated blocks are nowadays widely used in academia or are commercially available for molecular imaging systems. The results obtained for the three SiPM arrays when using those crystals, are comparable, without observing any significant different among them.This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No 695536). It has also been supported by the Spanish Ministerio de Economia, Industria y Competitividad under Grant TEC2016-79884-C2-1-R.Gonzalez-Montoro, A.; González Martínez, AJ. (2019). Performance comparison of large-area SiPM arrays suitable for gamma ray detectors. Biomedical Physics & Engineering Express. 5(4):1-10. https://doi.org/10.1088/2057-1976/ab0f6eS11054Henseler, D., Grazioso, R., Nan Zhang, & Schmand, M. (2009). SiPM performance in PET applications: An experimental and theoretical analysis. 2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC). doi:10.1109/nssmic.2009.5402157Buzhan, P., Dolgoshein, B., Filatov, L., Ilyin, A., Kantzerov, V., Kaplin, V., … Smirnov, S. (2003). Silicon photomultiplier and its possible applications. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 504(1-3), 48-52. doi:10.1016/s0168-9002(03)00749-6Dolgoshein, B., Balagura, V., Buzhan, P., Danilov, M., Filatov, L., Garutti, E., … Tikhomirov, I. (2006). Status report on silicon photomultiplier development and its applications. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 563(2), 368-376. doi:10.1016/j.nima.2006.02.193Berard, P., Couture, M., Deschamps, P., Laforce, F., & Dautet, H. (2011). Performance measurement for a new low dark count UV-SiPM. 2011 IEEE Nuclear Science Symposium Conference Record. doi:10.1109/nssmic.2011.6154109Moliner, L., González, A. J., Soriano, A., Sánchez, F., Correcher, C., Orero, A., … Benlloch, J. M. (2012). Design and evaluation of the MAMMI dedicated breast PET. Medical Physics, 39(9), 5393-5404. doi:10.1118/1.4742850Gonzalez, A. J., Aguilar, A., Conde, P., Hernandez, L., Moliner, L., Vidal, L. F., … Benlloch, J. M. (2016). A PET Design Based on SiPM and Monolithic LYSO Crystals: Performance Evaluation. IEEE Transactions on Nuclear Science, 63(5), 2471-2477. doi:10.1109/tns.2016.2522179Gonzalez-Montoro, A., Benlloch, J. M., Gonzalez, A. J., Aguilar, A., Canizares, G., Conde, P., … Sanchez, F. (2017). Performance Study of a Large Monolithic LYSO PET Detector With Accurate Photon DOI Using Retroreflector Layers. IEEE Transactions on Radiation and Plasma Medical Sciences, 1(3), 229-237. doi:10.1109/trpms.2017.2692819González-Montoro, A., Sánchez, F., Martí, R., Hernández, L., Aguilar, A., Barberá, J., … González, A. J. (2018). Detector block performance based on a monolithic LYSO crystal using a novel signal multiplexing method. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 912, 372-377. doi:10.1016/j.nima.2017.10.098Ronzhin, A., Albrow, M., Los, S., Martens, M., Murat, P., Ramberg, E., … Ritt, S. (2013). A SiPM-based TOF-PET detector with high speed digital DRS4 readout. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 703, 109-113. doi:10.1016/j.nima.2012.11.043Kim, C., McDaniel, D., Malaney, J., McBroom, G., Peterson, W., Tran, V. H., … Ganin, A. (2012). Time-of-flight PET-MR detector development with silicon photomultiplier. 2012 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC). doi:10.1109/nssmic.2012.6551808Schaart, D. R., van Dam, H. T., Seifert, S., Vinke, R., Dendooven, P., Löhner, H., & Beekman, F. J. (2009). A novel, SiPM-array-based, monolithic scintillator detector for PET. Physics in Medicine and Biology, 54(11), 3501-3512. doi:10.1088/0031-9155/54/11/01

Electrochemical treatment of aluminium alloy 7075 in aqueous solutions of imidazolium phosphonate and phosphate ionic liquids and scratch resistance of the resultant materials

The abilitiy of 1-ethyl-3-methylimidazolium ethylphosphonate ([ImPhosphonate]) and 1-ethyl-3-methylimidazolium diethylphosphate ([ImPhosphate]) ionic liquids (ILs) to interact with anodized Al7075 T6 aluminium alloy has been studied via electrochemical techniques under different applied potentials, inside and outside the passivation regions. SEM, EDX and XPS analysis have been used to study the composition of the surface coatings. The abrasion resistance after treatment with the ILs has been studied by scratch tests under progressive load, and compared with the performance of the unprotected material and the anodized alloy. While conventional anodization only improves the abrasion resistance of Al7075 in a 30%, the maximum reduction of the penetration depth, 86% with respect to Al7075 and 79% with respect to the anodized alloy, is obtained for the material treated with [ImPhosphonate] at 1 V, in the passivation region. Under these conditions, a phosphorus-containing alumina layer is formed. Applied voltages outside the passivation region for each IL activate the dissolution of the alumina layer and reduce abrasion resistance, not only with respect to the anodized material, but also with respect to the unprotected alloy.This work received the financial support of the Ministerio de Economía y Competitividad (MINECO, Spain) and the EU FEDER Program (Grant MAT2014-55384-P), and the Fundación Séneca, Agencia de Ciencia y Tecnología de la Región de Murcia for a “Ayuda a las Unidades y Grupos de Excelencia Científica de la Región de Murcia (Programa Séneca 2014)” (Grant 19877/GERM/14)

Comparacion de la memoria de trabajo en ninos con dificultades en el lenguaje en edad escolar

72 p.Este estudio compara el desempeño que tienen niños con y sin dificultades de lenguaje en tareas de memoria de trabajo. Existe gran controversia si los sujetos escolares que presentan dificultades de lenguaje tienen menor rendimiento en aspectos cognitivos como la memoria de trabajo. Los sujetos del estudio corresponderán a escolares pertenecientes a la ciudad de Talca. Se dividirán en dos grupos, de los cuales uno corresponde al grupo experimental y el otro al grupo control. El grupo experimental lo conformarán 20 sujetos que presenten dificultades de lenguaje, cuyas edades fluctúen entre los 7 y 7,11 años. Y el grupo control lo conformarán 20 sujetos sin dificultades de lenguaje cuyas edades fluctúen entre los 7 y 7,11 años