A Modal-Based Partition of Unity Finite Element Method for Elastic Wave Propagation Problems in Layered Media

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract] The time-harmonic propagation of elastic waves in layered media is simulated numerically by means of a modal-based Partition of Unity Finite Element Method (PUFEM). Instead of using the standard plane waves or the Bessel solutions of the Helmholtz equation to design the discretization basis, the proposed modal-based PUFEM explicitly uses the tensor-product expressions of the eigenmodes (the so-called Love and interior modes) of a spectral elastic transverse problem, which fulfil the coupling conditions among layers. This modal-based PUFEM approach does not introduce quadrature errors since the coefficients of the discrete matrices are computed in closed-form. A preliminary analysis of the high condition number suffered by the proposed method is also analyzed in terms of the mesh size and the number of eigenmodes involved in the discretization. The numerical methodology is validated through a number of test scenarios, where the reliability of the proposed PUFEM method is discussed by considering different modal basis and source terms. Finally, some indicators are introduced to select a convenient discrete PUFEM basis taking into account the observability of cracks located on a coupling boundary between two adjacent layers.This work has been supported by Xunta de Galicia project “Numerical simulation of high-frequency hydro-acoustic problems in coastal environments - SIMNUMAR” (EM2013/052), co-funded with European Regional Development Funds (ERDF). Moreover, the second and fifth authors have been supported by MICINN projects MTM2014-52876-R, MTM2017-82724-R, PID2019-108584RB-I00, and also by ED431C 2018/33 - M2NICA (Xunta de Galicia & ERDF) and ED431G 2019/01 - CITIC (Xunta de Galicia & ERDF). Additionally, the third author has been supported by Junta de Castilla y León under projects VA024P17 and VA105G18, co-financed by ERDF funds. This work has been funded for open access charge by Universidade da Coruña/CISUGXunta de Galicia; EM2013/052Xunta de Galicia; ED431C 2018/33Xunta de Galicia; ED431G 2019/01Junta de Castilla y León; VA024P17Junta de Castilla y León; VA105G1

Investigating the impact of quasar-driven outflows on galaxies at redshift 0.3-0.4

We present a detailed study of the kinematics of 19 QSO2s in the range 0.3 10^{8.5}$L$_{\odot}$. We aim at advancing our understanding of the AGN feedback phenomenon by correlating outflow properties with the presence of young stellar populations (YSPs) with ages <100 Myr, the optical morphology and the environment of the galaxies, and the radio luminosity. We characterize the ionized gas kinematics using the [OIII]$\lambda$5007$\r{A}$profiles, through three different outflow detection methods: multi-component parametric and flux-weighted and peak-weighted non-parametric. We detect ionized outflows in 18 QSO2s using the parametric analysis, and in all of them using the non-parametric methods. We find higher outflow masses using the parametric analysis (log M$_{OF}$(M$_{\odot}$)=6.47$\pm$0.50), and larger mass rates and kinetic powers with the flux-weighted non-parametric method (\.M$_{OF}$=4.0$\pm$4.4 M$_{\odot}$yr$^{-1}$and log(\.E$_{kin}$)=41.9$\pm$0.6 erg~s$^{-1}$). However, it is when we use the parametric method and the maximum outflow velocities that we measure the highest outflow mass rates and kinetic energies (23$\pm$35 M$_{\odot}$yr$^{-1}$and 42.9$\pm$0.6 erg s$^{-1}$). We do not find any significant correlation between the outflow properties and the previously mentioned galaxy properties. 4 out of 5 QSO2s without a YS<100 Myr show highly disturbed kinematics, whereas only 5 out of the 14 QSO2s with YSPs show similarly asymmetric [OIII] profiles. This might be indicative of negative feedback. The lack of correlation between the outflow properties and the presence of mergers in different interaction stages might be due to their different dynamical timescales. Lastly, the small radio luminosity range covered by our sample may be impeding the detection of any correlation between radio emission and outflow properties.Comment: 26 pages, 9 figures. Accepted for publication in A&

Sustained blood glutamate scavenging enhances protection in ischemic stroke

Stroke is a major cause of morbidity, mortality, and disability. During ischemic stroke, a marked and prolonged rise of glutamate concentration in the brain causes neuronal cell death. This study explores the protective effect of a bioconjugate form of glutamate oxaloacetate transaminase (hrGOT), which catalyzes the depletion of blood glutamate in the bloodstream for ~6 days following a single administration. When treated with this bioconjugate, a significant reduction of the infarct volume and a better retention of sensorimotor function was observed for ischemic rats compared to those treated with saline. Moreover, the equivalent dose of native hrGOT yielded similar results to the saline treated group for some tests. Targeting the bioconjugate to the blood-brain-barrier did not improve its performance. The data suggest that the bioconjugates draw glutamate out of the brain by displacing homeostasis between the different glutamate pools of the body

Influence of Sex on Stroke Prognosis: A Demographic, Clinical, and Molecular Analysis

Identifying the complexities of the effect of sex on stroke risk, etiology, and lesion progression may lead to advances in the treatment and care of ischemic stroke (IS) and non-traumatic intracerebral hemorrhage patients (ICH). We studied the sex-related discrepancies on the clinical course of patients with IS and ICH, and we also evaluated possible molecular mechanisms involved. The study's main variable was the patient's functional outcome at 3-months. Logistic regression models were used in order to study the influence of sex on different inflammatory, endothelial and atrial dysfunction markers. We recruited 5,021 patients; 4,060 IS (54.8% male, 45.2% female) and 961 ICH (57.1% male, 42.9% female). Women were on average 5.7 years older than men (6.4 years in IS, 5.1 years in ICH), and more likely to have previous poor functional status, to suffer atrial fibrillation and to be on anticoagulants. IS patients showed sex-related differences at 3-months regarding poorer outcome (55.6% women, 43.6% men, p < 0.0001), but this relationship was not found in ICH (56.8% vs. 61.9%, p = 0.127). In IS, women had higher levels of NT-proBNP and 3-months worse outcome in both cardioembolic and non-cardioembolic stroke patients. Stroke patients showed sex-related differences in pre-hospital data, clinical variables and molecular markers, but only IS patients presented independent sex-related differences in 3-months poor outcome and mortality. There was a relationship between the molecular marker of atrial dysfunction NT-proBNP and worse functional outcome in women, resulting in a possible indicator of increased dysfunction

Regulatory T cells participate in the recovery of ischemic stroke patients

BACKGROUND: Recent preclinical studies have shown that regulatory T cells (Treg) play a key role in the immune response after ischemic stroke (IS). However, the role of Treg in human acute IS has been poorly investigated. Our aim was to study the relationship between circulating Treg and outcome in human IS patients. METHODS: A total of 204 IS patients and 22 control subjects were recruited. The main study variable was good functional outcome at 3 months (modified Rankin scale </=2) considering infarct volume, Early Neurological Deterioration (END) and risk of infections as secondary variables. The percentage of circulating Treg was measured at admission, 48, 72 h and at day 7 after stroke onset. RESULTS: Circulating Treg levels were higher in IS patients compared to control subjects. Treg at 48 h were independently associated with good functional outcome (OR, 3.5; CI: 1.9-7.8) after adjusting by confounding factors. Patients with lower Treg at 48 h showed higher frequency of END and risk of infections. In addition, a negative correlation was found between circulating Treg at 48 h (r = - 0.414) and 72 h (r = - 0.418) and infarct volume. CONCLUSIONS: These findings suggest that Treg may participate in the recovery of IS patients. Therefore, Treg may be considered a potential therapeutic target in acute ischemic stroke

Antihyperthermic treatment decreases perihematomal hypodensity

OBJECTIVE: To investigate the effect on perihematomal hypodensity and outcome of a decrease in body temperature in the first 24 hours in patients with intracerebral hemorrhage (ICH). METHODS: In this retrospective study on a prospectively registered database, among the 1,100 patients, 795 met all the inclusion criteria. Temperature variations in the first 24 hours and perihematomal hypodensity (PHHD) were recorded. Patients >/=37.5 degrees C were treated with antihyperthermic drugs for at least 48 hours. The main objective was to determine the association among temperature variation, PHHD, and outcome at 3 months. RESULTS: The decrease in temperature in the first 24 hours increased the possibility of good outcome 11-fold. Temperature decrease, lower PHHD volume, and a good outcome were observed in 31.8% of the patients who received antihyperthermic treatment. CONCLUSION: The administration of early antihyperthermic treatment in patients with spontaneous ICH with a basal axillary temperature >/=37.5 degrees C resulted in good outcome in a third of the treated patients

Intra- and extra-hospital improvement in ischemic stroke patients: influence of reperfusion therapy and molecular mechanisms

Neuroprotective treatments in ischemic stroke are focused to reduce the pernicious effect of excitotoxicity, oxidative stress and inflammation. However, those cellular and molecular mechanisms may also have beneficial effects, especially during the late stages of the ischemic stroke. The objective of this study was to investigate the relationship between the clinical improvement of ischemic stroke patients and the time-dependent excitotoxicity and inflammation. We included 4295 ischemic stroke patients in a retrospective study. The main outcomes were intra and extra-hospital improvement. High glutamate and IL-6 levels at 24 hours were associated with a worse intra-hospital improvement (OR:0.993, 95%CI: 0.990-0.996 and OR:0.990, 95%CI: 0.985-0.995). High glutamate and IL-6 levels at 24 hours were associated with better extra-hospital improvement (OR:1.13 95%CI, 1.07-1.12 and OR:1.14, 95%CI, 1.09-1.18). Effective reperfusion after recanalization showed the best clinical outcome. However, the long term recovery is less marked in patients with an effective reperfusion. The variations of glutamate and IL6 levels in the first 24 hours clearly showed a relationship between the molecular components of the ischemic cascade and the clinical outcome of patients. Our findings suggest that the rapid reperfusion after recanalization treatment blocks the molecular response to ischemia that is associated with restorative processes

The Unreasonable Effectiveness of Encoder-Decoder Networks for Retinal Vessel Segmentation

We propose an encoder-decoder framework for the segmentation of blood vessels in retinal images that relies on the extraction of large-scale patches at multiple image-scales during training. Experiments on three fundus image datasets demonstrate that this approach achieves state-of-the-art results and can be implemented using a simple and efficient fully-convolutional network with a parameter count of less than 0.8M. Furthermore, we show that this framework - called VLight - avoids overfitting to specific training images and generalizes well across different datasets, which makes it highly suitable for real-world applications where robustness, accuracy as well as low inference time on high-resolution fundus images is required

Ancient DNA from Hunter-Gatherer and Farmer Groups from Northern Spain Supports a Random Dispersion Model for the Neolithic Expansion into Europe

Background/Principal Findings: The phenomenon of Neolithisation refers to the transition of prehistoric populations from a hunter-gatherer to an agro-pastoralist lifestyle. Traditionally, the spread of an agro-pastoralist economy into Europe has been framed within a dichotomy based either on an acculturation phenomenon or on a demic diffusion. However, the nature and speed of this transition is a matter of continuing scientific debate in archaeology, anthropology, and human population genetics. In the present study, we have analyzed the mitochondrial DNA diversity in hunter-gatherers and first farmers from Northern Spain, in relation to the debate surrounding the phenomenon of Neolithisation in Europe. Methodology/Significance: Analysis of mitochondrial DNA was carried out on 54 individuals from Upper Paleolithic and Early Neolithic, which were recovered from nine archaeological sites from Northern Spain (Basque Country, Navarre and Cantabria). In addition, to take all necessary precautions to avoid contamination, different authentication criteria were applied in this study, including: DNA quantification, cloning, duplication (51 % of the samples) and replication of the results (43 % of the samples) by two independent laboratories. Statistical and multivariate analyses of the mitochondrial variability suggest that the genetic influence of Neolithisation did not spread uniformly throughout Europe, producing heterogeneous genetic consequences in different geographical regions, rejecting the traditional models that explain the Neolithisation in Europe