725 research outputs found

    New constraints on the Middle Palaeozoic to Cenozoic burial and thermal history of the Holy Cross Mts. (Central Poland): results from numerical modelling

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    A 1-D burial-thermal modelling was performed using data from two borehole sections representative of the central part of the Holy Cross Mts. area. This area is located in the axial part of the Permian-Mesozoic Mid-Polish Trough that was inverted during the latest Cretaceous-Paleocene. The modelling involved different variants of restored stratigraphy of eroded Carboniferous to Cretaceous strata, whereas calibration was based on samples from cored Middle-Upper Devonian sediments. The modelling results are consistent with the assumption of a Variscan (Carboniferous-Early Permian) heat flow elevated up to 80 mWm-2, which is further confirmed by independent regional evidence. The zone of increased thermal maturity in the Devonian may be partly accounted for by a thicker Carboniferous section (by ca. 500 m) compared to previous estimates. Two variants of the post-Carboniferous geohistory were analysed. The variant of a thinner Permian-Mesozoic section, implying lower magnitude of the Late Cretaceous-Paleogene inversion, allows more realistic assumptions regarding heat flow distribution through time, including the possibility to incorporate an elevated Variscan heat flow. The alternative scenario, assuming deeper burial, generally lower heat flow and smaller Carboniferous thickness, is regarded as less probable. The accepted variant of the Permian-Mesozoic burial history implies that the total post-Carboniferous burial in the study area was on the order of 2000-2500 metres rather than 3000-3500 metres. The respective Upper Cretaceous thickness could have been 400 to 500 m instead of ca. 1000 m, whereas the Late Cretaceous-Paleogene inversion more likely started in the Santonian than in the late Maastrichtian. Consequently, the preferred magnitude of total inversion was on the order of 2500 m

    Ground states for a class of deterministic spin models with glassy behaviour

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    We consider the deterministic model with glassy behaviour, recently introduced by Marinari, Parisi and Ritort, with \ha\ H=i,j=1NJi,jσiσjH=\sum_{i,j=1}^N J_{i,j}\sigma_i\sigma_j, where JJ is the discrete sine Fourier transform. The ground state found by these authors for NN odd and 2N+12N+1 prime is shown to become asymptotically dege\-ne\-ra\-te when 2N+12N+1 is a product of odd primes, and to disappear for NN even. This last result is based on the explicit construction of a set of eigenvectors for JJ, obtained through its formal identity with the imaginary part of the propagator of the quantized unit symplectic matrix over the 22-torus.Comment: 15 pages, plain LaTe

    The impact of war on the development and progression of arterial hypertension and cardiovascular disease: protocol of a prospective study among Ukrainian female refugees.

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    Growing evidence supports the impact of psychological factors such as traumatic experiences and Post Traumatic Stress Disorder (PTSD) on the incidence of arterial hypertension (HTN) and cardiovascular diseases (CVD). The war in Ukraine is exposing million inhabitants to traumatic experiences and severe stress. Part of Ukrainians (mostly women and children) left the country to escape war. We report the protocol of a prospective study aiming at the assessment of the impact of war-induced stress on HTN and CVD in women Ukrainian refugees who moved to Poland. The study will be conducted in 3 stages. Stage 1 will assess the prevalence of HTN and PTSD among Ukrainian refugees and will estimate the impact of war-related trauma exposure on these parameters. Data on office blood pressure (BP) will be compared to data already collected in STEPS data 2019 and May Measurement Month 2021 in Ukraine, matched for age and sex. Stage 2 will involve subjects diagnosed with HTN and/or PTSD referred for management and follow-up of these conditions. Psychologic targeted therapies will be offered to subjects with confirmed PTSD, with a periodical reassessment of the severity of PTSD-associated symptoms and of its impact on HTN and cardiovascular health. Clinical history and characteristics will be compared among three groups: subjects with HTN and PTSD, with HTN without PTSD, with PTSD but without HTN. Stage 3 will involve a subgroup among those screened in Stage 1, with the objective of investigating the biological mechanisms underlying the relation between HTN and trauma exposure, identifying early signs of subclinical target organ damage in subjects with HTN with/without PTSD. This study will test the hypothesis that trauma exposure and psychological stress contribute to BP elevation and progression of CVD in this population. It will provide new evidence on the effect of an integrated management, including psychological therapy, on BP and cardiovascular risk. Such approach may be further tested and extrapolated to other populations exposed to war and chronic violence, migrants and refugees around the world. number 2022/45/P/NZ5/02812

    Differentiating patients with obstructive sleep apnea from healthy controls based on heart rate - blood pressure coupling quantified by entropy-based indices

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    We introduce an entropy-based classification method for pairs of sequences (ECPS) for quantifying mutual dependencies in heart rate and beat-to-beat blood pressure recordings. The purpose of the method is to build a classifier for data in which each item consists of the two intertwined data series taken for each subject. The method is based on ordinal patterns, and uses entropy-like indices. Machine learning is used to select a subset of indices most suitable for our classification problem in order to build an optimal yet simple model for distinguishing between patients suffering from obstructive sleep apnea and a control group.Comment: 7 figure

    Do the asymmetry and the size of the structures of the temporal lobe persist in early stages of schizophrenia?

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    A total of 14 patients of various ages diagnosed with schizophrenia and, as an age-matched control group, 12 healthy subjects were examined using the MRI method of neuro-imaging. The volume of the following structures was evaluated in the right and left hemispheres: the superior temporal gyrus, the basolateral temporal area (the region including the middle temporal gyrus, inferior temporal gyrus and fusiform gyrus), the parahippocampal gyrus, the hippocampal head, the amygdaloid body and the inferior horn of the lateral ventricle. In schizophrenia a significant increase in the volume of the amygdaloid body on both the left and right sides was observed. In the patients, as in the control group, we noticed significant asymmetry between the left and right sides in the volume of the structures studied. The left amygdaloid body was significantly larger than the right, whereas the left hippocampal head and the temporal horn of the lateral ventricle were smaller than the right. Our findings suggest that in the early stages of schizophrenia, despite the increased volume of the amygdaloid body, the asymmetry between the structures of the temporal lobe is still present. However, the changes observed in the temporal lobe could be related to the functional disturbances observed in this disease

    Two-way FSI modelling of blood flow through CCA accounting on-line medical diagnostics in hypertension

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    Flow parameters can induce pathological changes in the arteries. We propose a method to asses those parameters using a 3D computer model of the flow in the Common Carotid Artery. Input data was acquired using an automatic 2D ultrasound wall tracking system. This data has been used to generate a 3D geometry of the artery. The diameter and wall thickness have been assessed individually for every patient, but the artery has been taken as a 75mm straight tube. The Young’s modulus for the arterial walls was calculated using the pulse pressure, diastolic (minimal) diameter and wall thickness (IMT). Blood flow was derived from the pressure waveform using a 2-parameter Windkessel model. The blood is assumed to be non-Newtonian. The computational models were generated and calculated using commercial code. The coupling method required the use of Arbitrary Lagrangian-Euler formulation to solve Navier-Stokes and Navier-Lamè equations in a moving domain. The calculations showed that the distention of the walls in the model is not significantly different from the measurements. Results from the model have been used to locate additional risk factors, such as wall shear stress or circumferential stress, that may predict adverse hypertension complications
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