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result(s) for
"J -F Macías-Pérez"
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Tracing Soil Contamination from Pre-Roman Slags at the Monte Romero Archaeological Site, Southwest Spain
by
Pérez-Macías, Juan Aurelio
,
Fernández-Caliani, Juan Carlos
in
Analytical chemistry
,
Antimonates
,
Archaeological sites
2024
Soil serves as a repository of human history, preserving artifacts within its horizons. However, the presence of chemically reactive remnants, such as ancient slags, can significantly impact the surrounding soil environment. This paper addresses this scarcely explored issue by focusing on soil contamination arising from pre-Roman slag deposits at the Monte Romero archaeological site in southwest Spain, dating back to the Tartessian period (c. 7th century BC). Through the high-resolution microscopy examination of slag wastes and the trace element analysis of soil samples by ICP-OES, this study evaluated current contamination status using a multi-index approach. The results revealed markedly high levels of Pb (>5000 mg kg−1), Cu (up to 2730 mg kg−1), and As (up to 445 mg kg−1) in the soil compared to a control sample. The identification of secondary complex compounds like Cu arsenates and Pb arsenates/antimonates within slag cavities suggests post-depositional weathering processes, leading to the dispersion of potentially toxic elements into the surrounding soil. Assessments through indices of contamination and potential ecological risk highlighted severe contamination, particularly concerning Ag, Pb, Sb, Cu, and As. This study underscores the importance of addressing potential environmental hazards associated with archaeological sites hosting remnants of metal production.
Journal Article
Amantadine and/or transcranial magnetic stimulation for fatigue associated with multiple sclerosis (FETEM): study protocol for a phase 3 randomised, double-blind, cross-over, controlled clinical trial
by
Hernández, Miguel Ángel
,
Pérez-Macías, Natalia
,
Padrón, Iván
in
Adult
,
Amantadine - therapeutic use
,
Chemotherapy
2024
IntroductionFatigue is one of the most disabling symptoms of multiple sclerosis (MS), and effective treatments are lacking. Amantadine is one of the most used treatments, although its efficacy is under debate. Transcranial magnetic stimulation (TMS) is a promising intervention that has shown positive effects in some preliminary investigations. We aim to investigate the effect of 6 weeks of amantadine and/or TMS in fatigue due to MS.Methods and analysisThe study is a national, multicentre, phase 3, randomised, double-blind, cross-over, placebo-controlled and sham-controlled clinical trial. Adult patients with relapsing-remitting MS, Expanded Disability Status Scale score of 1.5–4.5 and Fatigue Severity Score>4 are eligible for the trial. Participants will be randomised to one of the sequences of the study. Each sequence consists of four periods of 6 weeks of treatment and three washout periods of 12–18 weeks. All patients will receive all the combinations of therapies. The primary outcome is the Modified Fatigue Impact Scale. The secondary outcomes are the Symbol Digit Modalities Test (cognition), Beck Depression Inventory-II (depressive symptoms) and Short-Survey 12 (quality of life). Safety and cost-effectiveness will also be evaluated. An exploratory substudy including MRI and blood biomarkers will be conducted.Ethics and disseminationThe study is approved by the Ethics Committee of the Hospital Clinico San Carlos and the Spanish Agency of Medications and Medical Devices. All study findings will be published in scientific peer-reviewed journals and presented at relevant scientific conferences.Trial registration numberEudraCT 2021-004868-95; NCT05809414.
Journal Article
Microfabrication Technology for Large Lekid Arrays: From Nika2 to Future Applications
by
Le Sueur, H.
,
Coiffard, G.
,
Peck, I.
in
Astrophysics
,
Characterization and Evaluation of Materials
,
Condensed Matter Physics
2016
The lumped element kinetic inductance detectors (LEKID) demonstrated full maturity in the New IRAM KID Arrays (NIKA) instrument. These results allow directly comparing LEKID performance with other competing technologies (TES, doped silicon) in the mm and sub-mm range. A continuing effort is ongoing to improve the microfabrication technologies and concepts in order to satisfy the requirements of new instruments. More precisely, future satellites dedicated to cosmic microwave background (CMB) studies will require the same focal plane technology to cover, at least, the frequency range of 60–600 GHz. Aluminium LEKID developed for NIKA have so far demonstrated, under real telescope conditions, a performance approaching photon noise limitation in the band 120–300 GHz. By implementing superconducting bi-layers, we recently demonstrated LEKID arrays working in the range 80–120 GHz and with sensitivities approaching the goals for CMB missions. NIKA itself (350 pixels) is followed by a more ambitious project requiring several thousand (3000–5000) pixels. NIKA2 has been installed in October 2015 at the IRAM 30-m telescope. We will describe in detail the technological improvements that allowed a relatively harmless tenfold up-scaling in pixels count without degrading the initial sensitivity. In particular, we will briefly describe a solution to simplify the difficult fabrication step linked to the slot-line propagation mode in coplanar waveguide.
Journal Article
Configuration of Probe Tones for MKID Readout with Frequency Sweeping Scheme
2022
We are developing detector arrays using microwave kinetic inductance detectors (MKIDs) for astronomical observations in the 100-GHz band and a readout system for MKID arrays with frequency sweeping scheme. Probe tones in this scheme are generated and acquired by a frequency sweep probe (FSP) which is a digital fast Fourier transform spectrometer (FFTS), while the probe tones are converted and modulated by an intermediate frequency (IF) section. Since the values of the resonance frequencies change under different photon backgrounds, an appropriate method to configure the probe tones is essential to preserve the dynamic of the detected signals. We considered a general IF section which is a cascade of up/down converter pairs and found that its characteristics can be described with the base band, the target band, the sign of probe tone order, and the sign of frequency sweep direction. We implemented an algorithm to make a list of tone frequencies from a list of resonance frequencies given. Using this configuring method, we assembled IF sections for an antenna-coupled MKID array and for a LEKID array and set up a prototype FSP. The resonance frequencies of the antenna-coupled MKIDs and the LEKIDs are at 4.6–5.1 GHz and 0.6–1.0 GHz, respectively, and their spectra were obtained successfully. The method enables us to configure the readout system for both types of arrays.
Journal Article
SOFIA/HAWC+ observations of the Crab Nebula: dust properties from polarised emission
2022
Supernova remnants (SNRs) are well-recognised dust producers, but their net dust production rate remains elusive due to uncertainties in grain properties that propagate into observed dust mass uncertainties, and determine how efficiently these grains are processed by reverse shocks. In this paper, we present a detection of polarised dust emission in the Crab pulsar wind nebula, the second SNR with confirmed polarised dust emission after Cassiopeia A. We constrain the bulk composition of the dust with new SOFIA/HAWC+ polarimetric data in band C 89 um and band D 154 um. After correcting for synchrotron polarisation, we report dust polarisation fractions ranging between 3.7-9.6 per cent and 2.7-7.6 per cent in three individual dusty filaments at 89 and 154 um, respectively. The detected polarised signal suggests the presence of large (> 0.05-0.1 um) grains in the Crab Nebula. With the observed polarisation, and polarised and total fluxes, we constrain the temperatures and masses of carbonaceous and silicate grains. We find that the carbon-rich grain mass fraction varies between 12 and 70 per cent, demonstrating that carbonaceous and silicate grains co-exist in this SNR. Temperatures range from 40 K to 70 K and from 30 K to 50 K for carbonaceous and silicate grains, respectively. Dust masses range from 10^{-4} Msol to 10^{-2} Msol for carbonaceous grains and to 10^{-1} Msol for silicate grains, in three individual regions.
Detection of the magnetar XTE J1810-197 at 150 and 260 GHz with the NIKA2 Kinetic Inductance Detector camera
2020
The investigation of pulsars between millimetre and optical wavelengths is challenging due to the faintness of the pulsar signals and the relative low sensitivity of the available facilities compared to 100-m class telescopes operating in the centimetre band. The Kinetic Inductance Detector (KID) technology offers large instantaneous bandwidths and a high sensitivity that can help to substantially increase the ability of existing observatories at short wavelengths to detect pulsars and transient emission. To investigate the feasibility of detecting pulsars with KIDs, we observed the anomalous X-ray pulsar XTE J1810-197 with the New IRAM KIDs Array-2 (NIKA2) camera installed at the IRAM 30-m Telescope in Spain. We detected the pulsations from the pulsar with NIKA2 at its two operating frequency bands, 150 and 260 GHz (\\(\\lambda\\)=2.0 and 1.15 mm, respectively). This is the first time that a pulsar is detected with a receiver based on KID technology in the millimetre band. In addition, this is the first report of short millimetre emission from XTE J1810-197 after its reactivation in December 2018, and it is the first time that the source is detected at 260 GHz, which gives us new insights into the radio emission process of the star.
C27 LET'S PRETEND WE'RE MARRIED: THE RIGHT VENTRICLE AND THE PULMONARY VASCULATURE: Tp Receptor Antagonism Improves Right Ventricular Adaptation To Pressure Overload Via Changes In Calcium Signaling
2017
Authors: Erica J. Carrier, Ines Macias-Perez, Leo Pavliv, Anna R. Hemnes, Kyungsoo Kim, Bjorn Knollmann, and James D. West Rationale: Right ventricular (RV) failure is the primary cause of death in pulmonary arterial hypertension (PAH), and is a significant cause of morbidity and mortality in other forms of pulmonary hypertension. Results: Treatment with the TPr antagonist CPI211 led to improvement in RV contractile function and decrease in ventricular dilation, even when begun 2 weeks post-PAB, at which point fibrosis is already well-established.
Journal Article
Lumped element kinetic inductance detectors maturity for space-borne instruments in the range between 80 and 180 GHz
2016
This work intends to give the state-of-the-art of our knowledge of the performance of LEKIDs at millimetre wavelengths (from 80 to 180~GHz). We evaluate their optical sensitivity under typical background conditions and their interaction with ionising particles. Two LEKID arrays, originally designed for ground-based applications and composed of a few hundred pixels each, operate at a central frequency of 100, and 150~GHz (\\(\\Delta \\nu / \\nu\\) about 0.3). Their sensitivities have been characterised in the laboratory using a dedicated closed-circle 100~mK dilution cryostat and a sky simulator, allowing for the reproduction of realistic, space-like observation conditions. The impact of cosmic rays has been evaluated by exposing the LEKID arrays to alpha particles (\\(^{241}\\)Am) and X sources (\\(^{109}\\)Cd) with a readout sampling frequency similar to the ones used for Planck HFI (about 200~Hz), and also with a high resolution sampling level (up to 2~MHz) in order to better characterise and interpret the observed glitches. In parallel, we have developed an analytical model to rescale the results to what would be observed by such a LEKID array at the second Lagrangian point.
PACT. II. Pressure profiles of galaxy clusters using Planck and ACT
2021
The pressure of hot gas in groups and clusters of galaxies is a key physical quantity, which is directly linked to the total mass of the halo and several other thermodynamical properties. In the wake of previous observational works on the hot gas pressure distribution in massive halos, we have investigated a sample of 31 clusters detected in both the Planck and Atacama Cosmology Telescope (ACT), MBAC surveys. We made use of an optimised Sunyaev-Zeldovich (SZ) map reconstructed from the two data sets and tailored for the detection of the SZ effect, taking advantage of both Planck coverage of large scales and the ACT higher spatial resolution. Our average pressure profile covers a radial range going from 0.04xR_500 in the central parts to 2.5xR_500 in the outskirts. In this way, it improves upon previous pressure-profile reconstruction based on SZ measurements. It is compatible, as well as competitive, with constraints derived from joint X-ray and SZ analysis. This work demonstrates the possibilities offered by large sky surveys of the SZ effect with multiple experiments with different spatial resolutions and spectral coverages, such as ACT and Planck.
Development and application of metamaterial-based Half-Wave Plates for the NIKA and NIKA2 polarimeters
by
Monfardini, A
,
Macias-Perez, J
,
Catalano, A
in
Astronomical polarimetry
,
Celestial bodies
,
Channeling
2020
CONTEXT.Large field-of-view imaging/polarimetry instruments operating at millimeter and submm wavelengths are fundamental tools to understand the role of magnetic fields (MF) in channeling filament material into prestellar cores providing a unique insight in the physics of galactic star-forming regions. Among other topics, at extra-galactic scales, polarization observations of AGNs will allow us to constrain the possible physical conditions of the emitting plasma from the jets and/or exploring the physics of dust inside supernova remnants. The kilo-pixel NIKA2 camera, installed at the IRAM 30-m telescope, represents today one of the best tools available to the astronomers to produce simultaneous intensity/polarimetry maps over large fields at 260 GHz (1.15 mm). AIMS.The polarization measurement, in NIKA and NIKA2, is achieved by rapidly modulating the total incoming polarization. This allows in the end to safely isolate the small science signal from the large, un-polarized and strongly variable, atmospheric background. METHODS.The polarization modulation is achieved by inserting a fast rotating Half-Wave Plate (HWP) in the optical beam. In order to allow wide field-of-view observations, the plate has to be large, with a diameter exceeding 250 mm. The modulation of the polarized signal, at 12 Hz, requires also the waveplate to be sufficiently light. In addition, this key optical element has to exhibit optimal electromagnetic characteristics in terms of transmission and differential phase-shift. For this purpose, three metamaterial HWPs have been developed using the mesh-filter technology. The knowledge acquired in developing the first two single-band HWPs was used to achieve the more challenging performance requirements of the last dual-band HWP. The first and the third waveplates met the requirements for both the NIKA and NIKA2 instruments. RESULTS.(abridged)