303 research outputs found
Towards Quantifying the Impact of Triaxiality on Optical Signatures of Galaxy Clusters: Weak Lensing and Galaxy Distributions
We present observational evidence of the impact of triaxiality on radial
profiles that extend to 40~Mpc from galaxy cluster centres in optical
measurements. We perform a stacked profile analysis from a sample of thousands
of nearly relaxed galaxy clusters from public data releases of the Dark Energy
Survey (DES) and the Dark Energy Camera Legacy Survey (DECaLS). Using the
central galaxy elliptical orientation angle as a proxy for galaxy cluster
orientation, we measure cluster weak lensing and excess galaxy density
axis-aligned profiles, extracted along the central galaxy's major or minor axes
on the plane-of-the-sky. Our measurements show a difference
per radial bin between the normalized axis-aligned profiles. The profile
difference between each axis-aligned profile and the azimuthally averaged
profile ( along major/minor axis) appears inside the clusters
( Mpc) and extends to the large-scale structure regime (
Mpc). The magnitude of the difference appears to be relatively insensitive to
cluster richness and redshift, and extends further out in the weak lensing
surface mass density than in the galaxy overdensity. Looking forward, this
measurement can easily be applied to other observational or simulation datasets
and can inform the systematics in cluster mass modeling related to triaxiality.
We expect imminent upcoming wide-area deep surveys, such as the Vera C. Rubin
Observatory's Legacy Survey of Space and Time (LSST), to improve our
quantification of optical signatures of cluster triaxiality.Comment: Submitted to MNRAS, minor differences because of recent comments,
comments are welcome and appreciate
In silico validation of electrocardiographic imaging to reconstruct the endocardial and epicardial repolarization pattern using the equivalent dipole layer source model
The solution of the inverse problem of electrocardiology allows the reconstruction of the spatial distribution of the electrical activity of the heart from the body surface electrocardiogram (electrocardiographic imaging, ECGI). ECGI using the equivalent dipole layer (EDL) model has shown to be accurate for cardiac activation times. However, validation of this method to determine repolarization times is lacking. In the present study, we determined the accuracy of the EDL model in reconstructing cardiac repolarization times, and assessed the robustness of the method under less ideal conditions (addition of noise and errors in tissue conductivity). A monodomain model was used to determine the transmembrane potentials in three different excitationrepolarization patterns (sinus beat and ventricular ectopic beats) as the gold standard. These were used to calculate the body surface ECGs using a finite element model. The resulting body surface electrograms (ECGs) were used as input for the EDLbased inverse reconstruction of repolarization times. The reconstructed repolarization times correlated well (COR > 0.85) with the gold standard, with almost no decrease in correlation after adding errors in tissue conductivity of the model or noise to the body surface ECG. Therefore, ECGI using the EDL model allows adequate reconstruction of cardiac repolarization times
Arrhythmia mechanism dependent pulmonary vein ablation in paroxysmal atrial fibrillation
Atrial fibrillation (AF) often requires invasive treatment by ablation to decrease symptom burden. The pulmonary veins (PV) are thought to trigger paroxysms of AF, and ablative PV isolation (PVI) is a cornerstone in AF treatment. However, incomplete PVI, where electrical conduction between the PV and left atrium (LA) is maintained, is curative of AF in a subset of patients. This implies that an antiarrhythmic effect other than electrical isolation between the PV and LA plays a role in AF prevention in these patients. We reason that the PV myocardium constitutes an arrhythmogenic substrate conducive to reentry in the patients with curative incomplete PVI. This PV substrate is amenable to ablation, even when conduction between the LA and PV persists. We propose that PV ablation strategies are differentiated to fit the arrhythmogenic mechanisms in the individual patient. PV substrate modification in patients with PV reentry may constitute a new therapeutic approach that is potentially simpler and more effective, in this subgroup of patients
Risk of out-of-hospital cardiac arrest in patients with rheumatoid arthritis:a nationwide study
AIM: Inflammatory cytokines in patients with rheumatoid arthritis (RA) directly affect cardiac electrophysiology by inhibiting cardiac potassium currents, leading to delay of cardiac repolarisation and QT-prolongation. This may result in lethal arrhythmias. We studied whether RA increases the rate of out-of-hospital cardiac arrest (OHCA) in the general population. METHODS: We conducted a nested case–control in a cohort of individuals between 1 June 2001 and 31 December 2015. Cases were OHCA patients from presumed cardiac causes, and were matched with non-OHCA-controls based on age, sex and OHCA date. Cox-regression with time-dependent covariates was conducted to assess the association between RA and OHCA by calculating the HR and 95% CI. Stratified analyses were performed according to sex and presence of cardiovascular diseases. Also, the association between OHCA and use of non-steroidal anti-inflammatory drugs (NSAIDs) in patients with RA was studied. RESULTS: We included 35 195 OHCA cases of whom 512 (1.45%) had RA, and 351 950 non-OHCA controls of whom 3867 (1.10%) had RA. We found that RA was associated with increased rate of OHCA after adjustment for cardiovascular comorbidities and use of QT-prolonging drugs (HR: 1.22, 95% CI: 1.11 to 1.34). Stratification by sex revealed that increased OHCA rate occurred in women (HR: 1.32, 95% CI: 1.16 to 1.50) but not in men (HR: 1.12, 95% CI: 0.97 to 1.28; P value interaction=0.046). OHCA rate of RA was not further increased in patients with cardiovascular disease. Finally, in patients with RA, use of NSAIDs was not associated with OHCA. CONCLUSION: In the general population, RA is associated with increased rate of OHCA in women but not in men
Diseño de pavimento rígido reforzado con fibra de vidrio en la avenida Quinta Avenida, Lurigancho, Lima, 2019
La falta de resistencia y la durabilidad de la losa de concreto del pavimento es un problema
hoy en día pues a pesar que existen muchas aplicaciones de nuevas tecnologías en el diseño
del pavimento, solo optan diseñar con los mismos materiales.
En el ámbito de los tipos de materiales que agregan en los pavimentos, este trabajo de
investigación ha optado por la fibra de vidrio AR por su alta resistencia, costo y movilización
en lo más importante las dos primeras mencionadas.
El presente trabajo de investigación se va a analizar cómo la fibra de vidrio AR cambia las
propiedades mecánicas del concreto mejorando compresión con mayor resistencia,
resistencia a la tracción como también a la flexión. Puesto que adicionando los porcentajes
de 0.45 y 0.90 de fibra vidrio AR a la mezcla brindará una excelente resistencia para un buen
diseño.
No obstante, se utilizó un programa nuevo, no tan conocido en el mercado, para el diseño de
pavimento con agregados de fibras, según los principios de AASHTO 93, se diseña el
pavimento con fibra de vidrio AR con la proporción de 0.9 % de fibra mejorando así la
resistencia del pavimento
Un ejercicio de prospectiva y construcción de escenarios para la transformación rural en Entre Ríos 2030
El objetivo de este trabajo fue documentar el progreso alcanzado en una iniciativa de transformación rural para la Provincia de Entre Ríos a través de la participación de actores en la construcción de posibles escenarios futuros. Los avances logrados en cuanto a un diagnóstico síntesis con revisiones individuales y colectivas por actores diversos, sumado a la identificación de objetivos específicos en línea con objetivos globales y aspiraciones locales para el desarrollo sustentable, constituyen un punto inicial necesario para la construcción de escenarios que alienten el pensamiento estratégico estimulando la implementación de un plan de acción para una trasformación rural sustentable.EEA ParanáFil: Valentinuz, Oscar Rodolfo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Paraná; ArgentinaFil: Calamari, Noelia Cecilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Paraná; ArgentinaFil: Coronel, Claudio Fabián. Universidad Nacional de Entre Ríos; ArgentinaFil: Seiler, Cristhian Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Instituto de Humanidades y Ciencias Sociales del Litoral (IHuCSo); ArgentinaFil: Seiler, Cristhian. Universidad Nacional del Litoral. Instituto de Humanidades y Ciencias Sociales del Litoral (IHuCSo); Argentin
The Response to Fish Oil in Patients with Heart Disease Depends on the Predominant Arrhythmia Mechanism
Long-term stress conditions and out-of-hospital cardiac arrest risk:a nested case-control study
Regional conduction slowing can explain inferolateral J waves and their attenuation by sodium channel blockers
International audienceJ waves in inferolateral leads are associated with an increased risk for idiopathic ventricular fibrillation. The mechanism behind such J waves is unknown. A similarity with Brugada syndrome (BS) exists but while administration of sodium (Na) channel blockers increases J waves in BS it attenuates inferolateral J waves. We hypothesized that regionally reduced conduction velocity in the lateral wall can explain both inferolateral J waves and their attenuation by Na-channel blockers.METHODS The effects of Na-channel block, reduced coupling, and increased transient outward current were evaluated with computer simulations using a detailed model of the human heart and torso. As far as possible findings were backed up with experiments in explanted pig hearts.RESULTS Reduced Na current in lateral but not in other regions induced inferolateral J waves. Increased transient outward current and cellular uncoupling caused only subthreshold J-point elevations. Administration of Na-channel blockers deformed and prolonged the QRS complex, masking the inferolateral J waves.CONCLUSION Regionally reduced Na current can explain inferolateral J waves. The fact that the lateral region is normally late-activated is crucial for the development of J waves and may explain the special importance of the inferolateral leads. The proposed mechanism also explains attenuation of J waves by Na-channel blockers
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