Goodness-of-Fit Tests to study the Gaussianity of the MAXIMA data

Goodness-of-Fit tests, including Smooth ones, are introduced and applied to detect non-Gaussianity in Cosmic Microwave Background simulations. We study the power of three different tests: the Shapiro-Francia test (1972), the uncategorised smooth test developed by Rayner and Best(1990) and the Neyman's Smooth Goodness-of-fit test for composite hypotheses (Thomas and Pierce 1979). The Smooth Goodness-of-Fit tests are designed to be sensitive to the presence of ``smooth'' deviations from a given distribution. We study the power of these tests based on the discrimination between Gaussian and non-Gaussian simulations. Non-Gaussian cases are simulated using the Edgeworth expansion and assuming pixel-to-pixel independence. Results show these tests behave similarly and are more powerful than tests directly based on cumulants of order 3, 4, 5 and 6. We have applied these tests to the released MAXIMA data. The applied tests are built to be powerful against detecting deviations from univariate Gaussianity. The Cholesky matrix corresponding to signal (based on an assumed cosmological model) plus noise is used to decorrelate the observations previous to the analysis. Results indicate that the MAXIMA data are compatible with Gaussianity.Comment: MNRAS, in pres

Magnetic long-range order induced by quantum relaxation in single-molecule magnets

Can magnetic interactions between single-molecule magnets (SMMs) in a crystal establish long-range magnetic order at low temperatures deep in the quantum regime, where the only electron spin-fluctuations are due to incoherent magnetic quantum tunneling (MQT)? Put inversely: can MQT provide the temperature dependent fluctuations needed to destroy the ordered state above some finite Tc, although it should basically itself be a T-independent process? Our experiments on two novel Mn4 SMMs provide a positive answer to the above, showing at the same time that MQT in the SMMs has to involve spin-lattice coupling at a relaxation rate equaling that predicted and observed recently for nuclear spin-mediated quantum relaxation.Comment: 4 pages, 3 figure

Polaron Transport in the Paramagnetic Phase of Electron-Doped Manganites

The electrical resistivity, Hall coefficient, and thermopower as functions of temperature are reported for lightly electron-doped Ca(1-x)La(x)MnO(3)(0 <= x <= 0.10). Unlike the case of hole-doped ferromagnetic manganites, the magnitude and temperature dependence of the Hall mobility for these compounds is found to be inconsistent with small-polaron theory. The transport data are better described by the Feynman polaron theory and imply intermediate coupling (alpha \~ 5.4) with a band effective mass, m*~4.3 m_0, and a polaron mass, m_p ~ 10 m_0.Comment: 7 pp., 7 Fig.s, to be published, PR

Load and temperature influence on the post-fire mechanical properties of steel reinforcements

[EN] An experimental study was carried out to evaluate the residual mechanical properties of steel reinforcements after their exposure to elevated temperatures. In order to reproduce real loading conditions, specimens were simultaneously subjected to a load level and a thermal cycle consisting of heating up to a target temperature and cooling back to room temperature. The target temperature was a percentage of the critical temperature, i.e., the temperature at which a specimen breaks when it is subjected to a constant tensile load and an increasing temperature at a constant rate. After that, the residual mechanical properties were obtained submitting the specimens to tensile testing until failure. Critical temperatures for each load level were obtained by means of transient-state tests. In parallel, unloaded specimens were subjected to the same thermal cycle for comparison purposes, and for the same reason steady-state tests were also performed. Results indicated that the residual mechanical behaviour of reinforcing bars depended not only on the maximum temperature reached, but also on the load level that was bearing during the thermal cycle. Depending on this combination of variables, the code requirements for a given ductility class of a reinforcement may not be satisfied in a post-fire situation. Considering the lack of information in this issue, the obtained data can be helpful in the assessment of reinforced concrete structures after a fire.The authors would like to express their sincere gratitude to the Spanish Agencia Estatal de Investigacion (AEI) for the help provided through the Project PID2019-105908RB-I00 and also to the European Union through the FEDER funds.Lapuebla-Ferri, A.; Pons Aliaga, D.; Romero, ML. (2021). Load and temperature influence on the post-fire mechanical properties of steel reinforcements. Journal of Constructional Steel Research. 185:1-13. https://doi.org/10.1016/j.jcsr.2021.106866S11318

Memory-efficient segmentation of high-resolution volumetric MicroCT images

In recent years, 3D convolutional neural networks have become the dominant approach for volumetric medical image segmentation. However, compared to their 2D counterparts, 3D networks introduce substantially more training parameters and higher requirement for the GPU memory. This has become a major limiting factor for designing and training 3D networks for high-resolution volumetric images. In this work, we propose a novel memory-efficient network architecture for 3D high-resolution image segmentation. The network incorporates both global and local features via a two-stage U-net-based cascaded framework and at the first stage, a memory-efficient U-net (meU-net) is developed. The features learnt at the two stages are connected via post-concatenation, which further improves the information flow. The proposed segmentation method is evaluated on an ultra high-resolution microCT dataset with typically 250 million voxels per volume. Experiments show that it outperforms state-of-the-art 3D segmentation methods in terms of both segmentation accuracy and memory efficiency

Post-fire residual strength and ductility of structural steels from hollow sections

[EN] Steel structures are severely affected by the extreme temperatures reached during a fire. After this, if the structure has not collapsed, the remaining elements can be reused if they are not excessively distorted or the material is still fit for service. In the last case, residual properties of steel must be adequate and fulfil the requirements of the current standards. On this matter, it is hypothesized that residual behaviour of steel not only depends on the highest temperature reached during the fire episode, but also on the load it was simultaneously bearing. This work is focused on an experimental study on the post-fire behaviour of structural steels. Specimens were cut from structural steel (S355) cold-formed circular hollow sections (CHS) and subjected to a combination of tensile stress and high temperature. Afterwards, the specimens were cooled in air back to room temperature and, finally, load was increased until specimen failure. The obtained results allowed discussing on the residual yield strength, ultimate strength and stiffness of the steel, and a special focus was put on the residual ductility. The results of this work can provide a basis to the appraisal of steel structures after fire, supporting the further decision on its reinstatement or subsequent demolition.The authors would like to express their sincere gratitude for the help provided through the Grant PID2019-105908RB-I00 funded by MCIN/AEI/ 10.13039/501100011033.Pons Aliaga, D.; Lapuebla-Ferri, A.; Romero, ML. (2022). Post-fire residual strength and ductility of structural steels from hollow sections. Ernst und Sohn. 458-466. https://doi.org/10.1002/cepa.177745846

Food, microbes, sex and old age: on the plasticity of gastrointestinal innervation

The gastrointestinal tract is innervated by its own enteric nervous system and by extrinsic neurons that connect it with the central nervous system. Innervation allows the gastrointestinal tract to sense and respond to diverse stimuli, adjusting motility and secretion, but also affecting our physiology, behaviour and immunity. The mechanisms underlying the formation of gastrointestinal neurons are beginning to be elucidated; those that keep them plastic over an organism's lifetime remain to be explored. Here, we review the effects of microbiota, nutrients, sex and ageing on the morphology and function of gastrointestinal innervation in mammals, and discuss how this plasticity shapes gut-brain crosstalk and whole-body physiology. We also highlight insights gained by nascent studies of the enteric innervation of Drosophila melanogaster

Goodness-of-fit tests of Gaussianity: constraints on the cumulants of the MAXIMA data

In this work, goodness-of-fit tests are adapted and applied to CMB maps to detect possible non-Gaussianity. We use Shapiro-Francia test and two Smooth goodness-of-fit tests: one developed by Rayner and Best and another one developed by Thomas and Pierce. The Smooth tests test small and smooth deviations of a prefixed probability function (in our case this is the univariate Gaussian). Also, the Rayner and Best test informs us of the kind of non-Gaussianity we have: excess of skewness, of kurtosis, and so on. These tests are optimal when the data are independent. We simulate and analyse non-Gaussian signals in order to study the power of these tests. These non-Gaussian simulations are constructed using the Edgeworth expansion, and assuming pixel-to-pixel independence. As an application, we test the Gaussianity of the MAXIMA data. Results indicate that the MAXIMA data are compatible with Gaussianity. Finally, the values of the skewness and kurtosis of MAXIMA data are constrained by |S| \le 0.035 and |K| \le 0.036 at the 99% confidence level.Comment: New Astronomy Reviews, in pres

Mentoring teachers: An interview with Angi Malderez

In this interview, Dr Angi Malderez shares her journey as a teacher, and becoming a teacher educator and a mentor trainer. She defines mentoring as the one-to-one support by a relatively more experienced teacher for the growth and learning of another, and for their integration into the school culture and the wider professional culture. She highlights the importance of mentoring in education, and discusses the conditions that mentoring requires for its sustainability and success for all the actors in the educational community

Interactive Visual Histories for Vector Graphics

Presentation and graphics software enables users to experiment with variations of illustrations. They can revisit recent editing operations using the ubiquitous undo command, but they are limited to sequential exploration. We propose a new interaction metaphor and visualization for operation history. While editing, a user can access a history mode in which actions are denoted by graphical depictions appearing on top of the document. Our work is inspired by the visual language of film storyboards and assembly instructions. Our storyboard provides an interactive visual history, summarizing the editing of a document or a selected object. Each view is composed of action depictions representing the userâ s editing actions and enables the user to consider the operation history in context rather than in a disconnected list view. This metaphor provides instant access to any past action and we demonstrate that this is an intuitive interface to a selective undo mechanism