Cenozoic exhumation history of the Alborz Mountains, Iran: New constraints from low-temperature chronometry

[1] The Alborz Mountains in the north of the Turkish-Iranian Plateau mainly developed in the Cenozoic as a consequence of the closure of Neo-Tethys and continental collision between Arabia and Eurasia. Cenozoic growth of the fold-and-thrust belt exploited an older Palaezoic-Mesozoic crustal fabric but the extent to which this governed the overall form of the mountain belt is unclear. To determine when and how the Alborz mountain belt has grown, apatite fission track (AFT) and (U-Th)/He (AHe) thermochronometry were performed on 46 bedrock samples collected along 8 transects across the range. AFT central ages range from 157 ± 24 Ma to 10 ± 1 Ma with most ages falling between 40 Ma and 10 Ma. AHe ages range from 17 ± 2 Ma to 6 ± 1 Ma. The data revealed enhanced exhumation ca. 35 ± 5 Ma, minor exhumation between ca. 30–20 Ma and an increase in exhumation thereafter. This pattern matches the tripartite Mid-Cenozoic stratigraphy of Central Iran, where Upper Oligocene-Lower Miocene carbonates are sandwiched between terrestrial clastic formations. The most intriguing thermochronometric signal found is a major acceleration of exhumation that initiated in the late Miocene to early Pliocene, recorded by the AHe data. There does not appear to be a direct tectonic cause for Pliocene intensified erosion, as convergence rates between Arabia and Eurasia have remained relatively constant. Enhanced exhumation at this time may reflect a climatically induced intensification of erosion during Caspian isolation and base level fall, or a regional tectonic re-organization of the Arabia-Eurasia collision, or both

Changes in synergy of transtibial amputee during gait: A pilot study

The number of lower limb amputations is increasing significantly in developed countries. The knowledge of muscle synergy in subjects with loss of muscles could help to understand the general neural strategy underlying muscle coordination in walking. The aim of this study was to investigate the differences in healthy subject's dominant leg, amputee's intact leg (IL) and the amputee's prosthetic leg (PL) muscles using synergy analysis. Concatenated non-negative matrix factorization (CNMF) was performed to divide the surface electromyography (sEMG) data obtained from 6 upper knee and 4 shank muscles into muscle synergy (S) and activation coefficient profile (C) during walking. The difference in S showed low to high correlations inter-subjectively. The high correlation suggests that the central nervous system (CNS) activates the same groups of muscles synergistically. Amputee's muscle alterations due to inadequate proprioceptive feedback, weight bearing deficiency in PL and prosthesis type could lead to a low correlation in S between groups. The C showed to be statistically significantly different in some regions of the gait cycle (GC). These findings could provide valuable information for rehabilitation purposes and development of a synergy-based controller from sEMG for future generations of prostheses

Left ventricular apical hypoplasia: Case report on cardiomyopathy and a history of sudden cardiac death

BACKGROUND: Isolated left ventricular apical hypoplasia with several different unrecognized dimensions is a newly discovered congenital anomaly of the heart. CASE REPORT: In this report, we describe a case of cardiomyopathy of this type occurring in a 13-year-old male with a history of mental retardation and sudden cardiac death (SCD) of second-degree relatives. The patient was referred for an evaluation of cardiac status. An echocardiography analysis demonstrated a spherical left ventricle (LV) appearance with mild mitral regurgitation. Cardiac magnetic resonance imaging (MRI) confirmed a spherical and truncated LV appearance. The right ventricle was found to have elongated and wrapped around the LV, and diverticulum was also seen in the cardiac MRI.CONCLUSION: To the best of our knowledge, this is to present the first case of LV apical hypoplasia combined with LV diverticulum and a family history of SCD. As more cases featuring this cardiomyopathy type are recognized, it will be easier to elucidate the natural history and management of such cardiac anomalies. © 2016, Isfahan University of Medical Sciences(IUMS). All rights reserved

Follow-up CMR in a case of Loeffler endocarditis

The typical finding of hypereosinophilic syndrome (Eosinophilic myocarditis) in the delayed enhancement (DE) cardiac magnetic resonance (CMR) is the �double V� sign, which includes (a) normal myocardium, (b) thickened enhanced endomyocardial layer, and (c) overlying apical thrombus. Corticosteroids may result in significant improvement of myocardial involvement. © 2020 The Authors. Clinical Case Reports published by John Wiley & Sons Lt

Cardiac magnetic resonance findings in coronavirus disease 2019

A subgroup of COVID-19 patients with cardiac magnetic resonance imaging evidence of myocardial inflammation may exhibit subendocardial fibrosis, compatible with myocardial infarction, while epicardial coronary arteries are normal. © 2021 The Authors. Clinical Case Reports published by John Wiley & Sons Ltd

An adult case with absence of left pulmonary artery and partial anomalous pulmonary venous connection: Case report and literature review

Unilateral absence of pulmonary artery is a rare congenital disorder that can remain asymptomatic until adulthood. Absence of left pulmonary artery (ALPA) has been reported in one-third of these patients. We are the first to introduce an adult case of ALPA associated with partial anomalous pulmonary venous connection. © 2021 The Authors. Clinical Case Reports published by John Wiley & Sons Ltd

Two Challenging Cases with COVID heart

COVID-19 affects the heart through various pathways. It can increase thrombotic complications that ultimately lead to myocardial infarction even in patients without a history of underlying heart disease. © 2020 The Authors. Clinical Case Reports published by John Wiley & Sons Lt

Nonlocal SU(3) chiral quark models at finite temperature: the role of the Polyakov loop

We analyze the role played by the Polyakov loop in the description of the chiral phase transition within the framework of nonlocal SU(3) chiral models with flavor mixing. We show that its presence provides a substantial enhancement of the predicted critical temperature, bringing it to a better agreement with the most recent results of lattice calculations.Comment: 9 pages, 1 figur

Difficult weaning from cardiopulmonary bypass after surgical VSD closure: An unusual rare case

The connection of the left coronary artery to the pulmonary artery may be asymptomatic due to high pulmonary vascular resistance in the context of left-to-right shunts. Before the repair of the mentioned anomalies, coronary anatomy must be defined. © 2020 The Authors. Clinical Case Reports published by John Wiley & Sons Ltd

Whightman function and scalar Casimir densities for a wedge with a cylindrical boundary

Whightman function, vacuum expectation values of the field square, and the energy-momentum tensor are investigated for a scalar field inside a wedge with and without a coaxial cylindrical boundary. Dirichlet boundary conditions are assumed on the bounding surfaces. The vacuum energy-momentum tensor is evaluated in the general case of the curvature coupling parameter. Making use of a variant of the generalized Abel-Plana formula, expectation values are presented as the sum of two terms. The first one corresponds to the geometry without a cylindrical boundary and the second one is induced by the presence of this boundary. The asymptotic behaviour of the field square, vacuum energy density and stresses near the boundaries are investigated. The additional vacuum forces acting on the wedge sides due the presence of the cylindrical boundary are evaluated and it is shown that these forces are attractive. As a limiting case, the geometry of two parallel plates perpendicularly intersected by a third one is analyzed.Comment: 19 pages, 6 figures, new section is added on the VEVs for the region outside the cylidrical shell, discussion and references added, accepted for publication in J. Phys.