59 research outputs found

    The Three Hundred project: a large catalogue of theoretically modelled galaxy clusters for cosmological and astrophysical applications

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    We introduce the The Three Hundred project, an endeavour to model 324 large galaxy clusters with full-physics hydrodynamical re-simulations. Here we present the dataset and study the differences to observations for fundamental galaxy cluster properties and scaling relations. We find that the modelled galaxy clusters are generally in reasonable agreement with observations with respect to baryonic fractions and gas scaling relations at redshift z = 0. However, there are still some (model-dependent) differences, such as central galaxies being too massive, and galaxy colours (g − r) being bluer (about 0.2 dex lower at the peak position) than in observations. The agreement in gas scaling relations down to 1013 h−1M⊙ between the simulations indicates that particulars of the sub-grid modelling of the baryonic physics only has a weak influence on these relations. We also include – where appropriate – a comparison to three semi-analytical galaxy formation models as applied to the same underlying dark matter only simulation. All simulations and derived data products are publicly available

    Large-Scale Phenotyping of an Accurate Genetic Mouse Model of JNCL Identifies Novel Early Pathology Outside the Central Nervous System

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    Cln3Δex7/8 mice harbor the most common genetic defect causing juvenile neuronal ceroid lipofuscinosis (JNCL), an autosomal recessive disease involving seizures, visual, motor and cognitive decline, and premature death. Here, to more thoroughly investigate the manifestations of the common JNCL mutation, we performed a broad phenotyping study of Cln3Δex7/8 mice. Homozygous Cln3Δex7/8 mice, congenic on a C57BL/6N background, displayed subtle deficits in sensory and motor tasks at 10–14 weeks of age. Homozygous Cln3Δex7/8 mice also displayed electroretinographic changes reflecting cone function deficits past 5 months of age and a progressive decline of retinal post-receptoral function. Metabolic analysis revealed increases in rectal body temperature and minimum oxygen consumption in 12–13 week old homozygous Cln3Δex7/8mice, which were also seen to a lesser extent in heterozygous Cln3Δex7/8 mice. Heart weight was slightly increased at 20 weeks of age, but no significant differences were observed in cardiac function in young adults. In a comprehensive blood analysis at 15–16 weeks of age, serum ferritin concentrations, mean corpuscular volume of red blood cells (MCV), and reticulocyte counts were reproducibly increased in homozygous Cln3Δex7/8 mice, and male homozygotes had a relative T-cell deficiency, suggesting alterations in hematopoiesis. Finally, consistent with findings in JNCL patients, vacuolated peripheral blood lymphocytes were observed in homozygous Cln3Δex7/8 neonates, and to a greater extent in older animals. Early onset, severe vacuolation in clear cells of the epididymis of male homozygous Cln3Δex7/8 mice was also observed. These data highlight additional organ systems in which to study CLN3 function, and early phenotypes have been established in homozygous Cln3Δex7/8 mice that merit further study for JNCL biomarker development

    The Three Hundred project : A large catalogue of theoretically modelled galaxy clusters for cosmological and astrophysical applications

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    We introduce the THE THREE HUNDRED project, an endeavour to model 324 large galaxy clusters with full-physics hydrodynamical re-simulations. Here we present the data set and study the differences to observations for fundamental galaxy cluster properties and scaling relations. We find that the modelled galaxy clusters are generally in reasonable agreement with observations with respect to baryonic fractions and gas scaling relations at redshift z = 0. However, there are still some (model-dependent) differences, such as central galaxies being too massive, and galaxy colours (g − r) being bluer (about 0.2 dex lower at the peak position) than in observations. The agreement in gas scaling relations down to 1013h−1M⊙ between the simulations indicates that particulars of the sub-grid modelling of the baryonic physics only has a weak influence on these relations. We also include – where appropriate – a comparison to three semi-analytical galaxy formation models as applied to the same underlying dark-matter-only simulation. All simulations and derived data products are publicly available.Instituto de Astrofísica de La PlataFacultad de Ciencias Astronómicas y Geofísica

    Voltage-Induced ON Switching of Magnetism in Ordered Arrays of Non-Ferrimagnetic Nanoporous Iron Oxide Microdisks

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    Tailoring the magnetic properties of ordered arrays of patterned structures usually requires stringent control of their size, pitch, microstructure, and composition. Here, a fundamentally different approach to manipulate the magnetic behavior of lithographed microdisks, based on the application of electrical voltage, is demonstrated. First, highly porous iron oxide films with virtually no magnetic response (OFF state) are grown by sol\u2013gel chemistry. Subsequently, arrays of microdisks (8 \ub5m in diameter) are obtained combining lithography with wet chemical etching processes. Electrolyte-gating (with an anhydrous electrolyte) is then employed to induce a tunable (i.e., \u201con-demand\u201d) ferromagnetic response in these disks (OFF\u2013ON switching of magnetism) at room temperature. The changes in magnetic properties are attributed to magnetoelectrically-driven oxygen ion migration, which is enhanced due to nanoporosity. This causes partial reduction of the oxide phases to metallic Fe. The effect can be considerably reversed by applying voltage of opposite polarity. These results are appealing for diverse technological applications that require the use of patterned structures with easily tunable magnetic properties, such as magnetic micro-electro-mechanical systems, microfluidic, and lab-on-a-chip platforms for biomedical therapies and, ultimately, energy-efficient magnetic memories or neuromorphic computing

    Quantifying impacts of forecast uncertainties on predicted storm surges

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    In this paper, we propose a framework for quantifying risks, including (1) the effects of forecast errors, (2) the ability to resolve critical grid features that are important to accurate site-specific forecasts, and (3) a framework that can move us toward performance-based/cost-based decisions, within an extremely fast execution time. A key element presently lacking in previous studies is the interrelationship between the effects of combined random errors and bias in numerical weather prediction (NWP) models and bias and random errors in surge models. This approach examines the number of degrees of freedom in present forecasts and develops an equation for the quantification of these types of errors within a unified system, given the number of degrees of freedom in the NWP forecasts. It is shown that the methodology can be used to provide information on the forecasts and along with the combined uncertainty due to all of the individual contributions. A potential important benefit from studies using this approach would be the ability to estimate financial and other trade-offs between higher-cost “rapid” evacuation methods and lower-cost “slower” evacuation methods. Analyses here show that uncertainty inherent in these decisions depends strongly on forecast time and geographic location. Methods based on sets of surge maxima do not capture this uncertainty and would be difficult to use for this purpose. In particular, it is shown that surge model bias can play a dominant role in distorting the forecast probabilities

    Dynamic electric-field-induced magnetic effects in cobalt oxide thin films: Towards magneto-ionic synapses

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    Voltage control of magnetism via electric-field-driven ion migration (magneto-ionics) has generated intense interest due to its potential to greatly reduce heat dissipation in a wide range of information technology devices, such as magnetic memories, spintronic systems or artificial neural networks. Among other effects, oxygen ion migration in transition-metal-oxide thin films can lead to the generation or full suppression of controlled amounts of ferromagnetism ('ON-OFF' magnetic transitions) in a non-volatile and fully reversible manner. However, oxygen magneto-ionic rates at room temperature are generally considered too slow for industrial applications. Here, we demonstrate that sub-second ON-OFF transitions in electrolyte-gated paramagnetic cobalt oxide films can be achieved by drastically reducing the film thickness from >200 nm down to 5 nm. Remarkably, cumulative magneto-ionic effects can be generated by applying voltage pulses at frequencies as high as 100 Hz. Neuromorphic-like dynamic effects occur at these frequencies, including potentiation (cumulative magnetization increase), depression (i.e., partial recovery of magnetization with time), threshold activation, and spike time-dependent magnetic plasticity (learning and forgetting capabilities), mimicking many of the biological synapse functions. The systems under investigation show features that could be useful for the design of artificial neural networks whose magnetic properties would be governed with voltage

    Impact of ICM disturbances on the mean pressure profile of galaxy clusters: A prospective study of the NIKA2 SZ large program with MUSIC synthetic clusters

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    Context. The mean pressure profile of the galaxy cluster population plays an essential role in cosmological analyses. An accurate characterization of the shape, intrinsic scatter, and redshift evolution of this profile is necessary to estimate some of the biases and systematic effects that currently prevent cosmological analyses based on thermal Sunyaev-Zel'dovich (tSZ) surveys from obtaining precise and unbiased cosmological constraints. This is one of the main goals of the ongoing NIKA2 SZ large program, which aims at mapping the tSZ signal of a representative cluster sample selected from the Planck and ACT catalogs and spans a redshift range 0.5 < z < 0.9. Aims. To estimate the impact of intracluster medium (ICM) disturbances that can be detected by NIKA2 on the mean pressure profile of galaxy clusters, we realized a study based on a synthetic cluster sample that is similar to that of the NIKA2 SZ large program. Methods. To reach this goal we employed the hydrodynamical N-body simulation Marenostrum MUltidark SImulations of galaxy Clusters (MUSIC). We simulated realistic NIKA2 and Planck tSZ observations, which were jointly analyzed to estimate the ICM pressure profile of each cluster. A comparison of the deprojected profiles with the true radial profiles directly extracted from the MUSIC simulation allowed us to validate the NIKA2 tSZ pipeline and to study the impact of ICM disturbances on the characterization of the ICM pressure distribution even at high redshift. After normalizing each profile by the integrated quantities estimated under the hydrostatic equilibrium hypothesis, we evaluated the mean pressure profile of the twin sample and show that it is compatible with that extracted directly from the MUSIC simulation in the scale range that can be recovered by NIKA2. We studied the impact of cluster dynamical state on both its shape and associated scatter. Results. We observe that at R500 the scatter of the distribution of normalized pressure profiles associated with the selected morphologically disturbed clusters is 65% larger than that associated with relaxed clusters. Furthermore, we show that using a basic modeling of the thermal pressure distribution in the deprojection procedure induces a significant increase of the scatter associated with the mean normalized pressure profile compared to the true distribution extracted directly from the simulation. Conclusions. We conclude that the NIKA2 SZ large program will facilitate characterization of the potential redshift evolution of the mean pressure profile properties due to the performance of the NIKA2 camera, thereby allowing for a precise measurement of cluster morphology and ICM thermodynamic properties up to R500 at high redshift
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