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Magnetic fields and their dynamical interplay with matter in galaxy clusters contribute to the physical properties and evolution of the intracluster medium. However, the current understanding of the origin and properties of cluster magnetic fields is still limited by observational challenges. In this article, we map the magnetic fields at hundreds-kpc scales of five clusters RXC J1314.4-2515, Abell 2345, Abell 3376, MCXC J0352.4-7401, and El Gordo using the synchrotron intensity gradient technique in conjunction with high-resolution radio observations from the Jansky Very Large Array (JVLA) and the Karoo Array Telescope (MeerKAT). We demonstrate that the magnetic field orientation of radio relics derived from synchrotron intensity gradient is in agreement with that obtained with synchrotron polarization. Most importantly, the synchrotron intensity gradient is not limited by Faraday depolarization in the cluster central regions and allows us to map magnetic fields in the radio halos of RXC J1314.4-2515 and El Gordo. We find that magnetic fields in radio halos exhibit a preferential direction along the major merger axis and show turbulent structures at higher angular resolution. The results are consistent with expectations from numerical simulations, which predict turbulent magnetic fields in cluster mergers that are stirred and amplified by matter motions. The current understanding of the origin and properties of cluster magnetic fields is limited by observational challenges. Here, the authors show that magnetic field orientations of galaxy clusters, including radio relic and radio halos, can be derived via combination of synchrotron intensity gradient technique with radio observations.

The central regions of galaxy clusters are permeated by magnetic fields and filled with relativistic electrons 1 . When clusters merge, the magnetic fields are amplified and relativistic electrons are re-accelerated by turbulence in the intracluster medium 2 , 3 . These electrons reach energies of 1–10 GeV and, in the presence of magnetic fields, produce diffuse radio halos 4 that typically cover an area of  around 1 Mpc 2 . Here we report observations of four clusters whose radio halos are embedded in much more extended, diffuse radio emission, filling a volume 30 times larger than that of radio halos. The emissivity in these larger features is about 20 times lower than the emissivity in radio halos. We conclude that relativistic electrons and magnetic fields extend far beyond radio halos, and that the physical conditions in the outer regions of the clusters are quite different from those in the radio halos. For four galaxy clusters it is shown that the radio halo emission is embedded in a much larger emission that extends over 2–3 Mpc, filling the volume of the clusters.

Galaxy clusters are the most massive gravitationally bound structures in the Universe.They grow by accreting smaller structures in a merging process that produces shocks and turbulence in the intracluster gas. We observed a ridge of radio emission connecting the merging galaxy clusters Abell 0399 and Abell 0401 with the Low-Frequency Array (LOFAR) telescope network at 140 megahertz. This emission requires a population of relativistic electrons and a magnetic field located in a filament between the two galaxy clusters. We performed simulations to show that a volume-filling distribution of weak shocks may reaccelerate a preexisting population of relativistic particles, producing emission at radio wavelengths that illuminates the magnetic ridge.

We present an experimental study aiming at the identification of the hydraulic conductivity in an aquifer which was packed according to four different configurations. The conductivity was estimated by means of slug tests, whereas the other parameters were determined by the grain size analysis. Prior to the fractal we considered the dependence of the conductivity upon the porosity through a power (scaling) law which was found in a very good agreement within the range from the laboratory to the meso-scale. The dependence of the conductivity through the porosity was investigated by identifying the proper fractal model. Results obtained provide valuable indications about the behavior, among the others, of the tortuosity, a parameter playing a crucial role in the dispersion phenomena taking place in the aquifers.

In Mongolia and Inner Mongolia, many residents live in traditional yurts, which have low energy efficiency due to the high thermal transmittance of their enclosures, made of woolen felt. Given the portable nature of the yurt, the identification of suitable insulation solutions is a major challenge. Multiple bubble wrap layering has been proposed as a potential insulation solution due to its low thermal conductivity, and low cost, but many practical challenges need to be overcome to make it usable. Bubble wrap has also the property of being transparent, so the merit is that it can be also employed both in opaque envelopes and translucent parts of the building envelope if protected, exists. The design hypothesis stems from the combination of these facts: (1) the thermal transmittance of the opaque envelope of traditional yurts can be substantially reduced; (2) the traditional yurt does not exploit the greenhouse effect because it has no transparent enclosures; so passive solar gain can be implemented by introducing suitable transparent enclosures in the envelope, oriented towards the equator; (3) traditional yurts enclose no thermal mass, so thermal mass in form of water enclosed in the containers can be introduced to the benefit of the passive solar gain management and passive cooling. These decisions operate many technical – structural, constructional, environmental – challenges, that will be confronted in future stages of the research. Simulations were conducted using Energy Plus, integrated within the Honeybee plugin of the Grasshopper platform. The preliminary results indicate that the design directions in question are promising.

We report the development of an indirect ELISA procedure for specific identification of chicken-egg yolk and animal glues in painting micro-samples. The results presented integrate previously published work on ELISA recognition of bovine β-casein and chicken ovalbumin in painting materials. The integrated final ELISA procedure—optimised for protein extraction, immuno-reagent concentrations, blocking solution, incubation time, and temperature—enables multiplex identification, in single samples, of proteinaceous materials, i.e. chicken-egg yolk and albumen, animal glues, and bovine milk and/or casein, mainly used by painters in the past. The procedure has been systematically tested on laboratory models of mural and easel paintings, both naturally and artificially aged, to assess possible inhibitory effects on the immuno-reaction caused by inorganic painting materials (pigments and substrates) and by protein degradation resulting from aging processes. Real samples from case studies, which had previously been investigated and characterised by spectroscopy and chromatography, were successfully studied by use of the developed ELISA procedure. The commercial availability of all the immuno-reagents used, the affordable analytical equipment, and the specificity, sensitivity, and rapidity of ELISA make this method very attractive to diagnostic laboratories in the field of cultural heritage science. Possible further developments to the analytical potential of this technique include improvement of antibody performance and inclusion of other classes of bio-molecules as analytical targets. Figure An ELISA indirect procedure is reported for the specific identification of chicken egg-yolk and animal glues in micro-samples from historical paintings; the method was experimented on laboratory models of mural and easel paintings, both naturally and artificially aged

We tested the hypothesis that the levels of bone remodeling mediators may be altered in Prader–Willi syndrome (PWS). We assessed RANKL, OPG, sclerostin, DKK-1 serum levels, and bone metabolism markers in 12 PWS children (7.8 ± 4.3 years), 14 PWS adults (29.5 ± 7.2 years), and 31 healthy controls matched for sex and age. Instrumental parameters of bone mineral density (BMD) were also evaluated. Lumbar spine BMD Z-scores were reduced in PWS children (P < 0.01), reaching osteopenic levels in PWS adults. PWS patients showed lower 25(OH)-vitamin D serum levels than controls (P < 0.001). Osteocalcin was increased in PWS children but reduced in adults respect to controls (P < 0.005 and P < 0.01, respectively). RANKL levels were higher in both pediatric and PWS adults than controls (P < 0.004), while OPG levels were significantly reduced (P < 0.004 and P < 0.006, respectively). Sclerostin levels were increased in children (P < 0.04) but reduced in adults compared to controls (P < 0.01). DKK-1 levels did not show significant difference between patients and controls. In PWS patients, RANKL, OPG, and sclerostin significantly correlated with metabolic and bone instrumental parameters. Consistently, with adjustment for age, multiple linear regression analysis showed that BMD and osteocalcin were the most important predictors for RANKL, OPG, and sclerostin in children, and GH and sex steroid replacement treatment in PWS adults. We demonstrated the involvement of RANKL, OPG, and sclerostin in the altered bone turnover of PWS subjects suggesting these molecules as markers of bone disease and new potential pharmacological targets to improve bone health in PWS.

The ENUBET project is aimed at designing and experimentally demonstrating the concept of monitored neutrino beams. These novel beams are enhanced by an instrumented decay tunnel, whose detectors reconstruct large-angle charged leptons produced in the tunnel and give a direct estimate of the neutrino flux at the source. These facilities are thus the ideal tool for high-precision neutrino cross-section measurements at the GeV scale because they offer superior control of beam systematics with respect to existing facilities. In this paper, we present the first end-to-end design of a monitored neutrino beam capable of monitoring lepton production at the single particle level. This goal is achieved by a new focusing system without magnetic horns, a 20 m normal-conducting transfer line for charge and momentum selection, and a 40 m tunnel instrumented with cost-effective particle detectors. Employing such a design, we show that percent precision in cross-section measurements can be achieved at the CERN SPS complex with existing neutrino detectors.

The ENUBET project aims at experimentally demonstrating the concept of monitored neutrino beams: the ideal tool for measurements of neutrino cross-sections with high precision by suppressing related systematics. Long baseline oscillation projects like DUNE and Hyper-Kamiokande will require this complementary facility to be able to fully exploit the data collected. In the last years the NP06/ENUBET project has demonstrated that the systematic uncertainties on the neutrino flux can be suppressed to 1% in an accelerator based facility where charged leptons produced in kaon and pion decays are monitored in an instrumented decay tunnel. Here we present an overview of the final beamline design, the tunnel instrumentation for high purity identification of charged leptons, the successful R&D programme and the framework for the assessment of the final systematics budget on the neutrino fluxes.The full implementation of such a facility in the CERN North Area is now under study in the framework of Physics Beyond Colliders with the goal of performing high precision cross section measurements at the GeV scale exploiting the ProtoDUNEs as neutrino detectors to collect ∼ 104νe and ∼ 6 · 106νμ CC interactions in less than 3 years of data taking.

Distant haloes in prospect The next generation of radio telescopes will enter what is virtually uncharted territory, observing the Universe at low radio frequencies with unprecedented resolution and sensitivity. A glimpse of what they might find is provided by the discovery of a new class of low frequency galaxy clusters. Deep observations with the Giant Metrewave Radio Telescope, located just north of Pune in India, reveal a radio halo at low frequencies associated with the merging cluster Abell 521. The halo has an extremely steep radio spectrum that makes it difficult to detect with observations at 1.4 GHz (the frequency at which all other known radio haloes have been studied). The spectrum supports a turbulent acceleration mechanism, which predicts that many radio haloes in the Universe should emit mainly at low frequencies. Clusters of galaxies are the largest gravitationally bound objects in the Universe. Magnetic fields and relativistic particles are mixed with the gas as revealed by giant 'radio haloes'. A radio halo at low frequencies associated with the merging cluster Abell 521 is reported. This halo has an extremely steep radio spectrum that makes it difficult to detect with observations at 1.4 GHz. The spectrum supports a turbulent acceleration mechanism, which predicts that many radio haloes in the Universe should emit mainly at low frequencies. Clusters of galaxies are the largest gravitationally bound objects in the Universe, containing about 10 15 solar masses of hot (10 8  K) gas, galaxies and dark matter in a typical volume of 10 Mpc 3 . Magnetic fields and relativistic particles are mixed with the gas as revealed by giant ‘radio haloes’, which arise from diffuse, megaparsec-scale synchrotron radiation at cluster centre 1 , 2 . Radio haloes require that the emitting electrons are accelerated in situ (by turbulence) 3 , 4 , 5 , 6 , or are injected (as secondary particles) by proton collisions into the intergalactic medium 7 , 8 , 9 , 10 . They are found only in a fraction of massive clusters that have complex dynamics 11 , 12 , 13 , 14 , which suggests a connection between these mechanisms and cluster mergers. Here we report a radio halo at low frequencies associated with the merging cluster Abell 521. This halo has an extremely steep radio spectrum, which implies a high frequency cut-off; this makes the halo difficult to detect with observations at 1.4 GHz (the frequency at which all other known radio haloes have been best studied). The spectrum of the halo is inconsistent with a secondary origin of the relativistic electrons, but instead supports turbulent acceleration, which suggests that many radio haloes in the Universe should emit mainly at low frequencies.