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

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

Humans don’t time sub-second intervals like a stopwatch

Many activities require the ability to estimate intervals of time in an accurate and flexible manner. A traditional and popular account suggests that humans possess a kind of internal stopwatch that can be started, paused and stopped at will. Here we test this idea by measuring variable performance errors in three experiments. Participants had to compare the total time accumulated during one to three short target intervals with a single standard interval. With two or more target intervals, participants had to pause, but not reset, their putative internal stopwatches. By establishing baseline performance at two different standard durations and extrapolating based on Weber’s law, we were able to estimate how much performance should have deteriorated when target segments contained breaks. The decrement in performance we observed far exceeded the stopwatch prediction, and also exceeded the simulated predictions of a modified stopwatch with a slowing pacemaker. The data thus favour either a counter that cannot be paused during sub-second durations or alternative models of sub-second interval duration discrimination which do not posit a count-based metric for time. We discuss several possible strategies which participants might have implemented in order to apply such clocks in the split-interval task

The Functional Architecture of Interval Timing

ABSTRACT The following set of experiments investigates the fundamental mechanism proposed to underlie interval timing and addresses a key question in timing research pertaining to the underlying functional architecture. Numerous models have been proposed in an attempt to illustrate and explain timing performance, some based on dedicated features employing a specialised mechanism, whilst others suggest that time perception is inherent in neural dynamics. An influential set of models posit that the brain contains a mechanism akin to a mental stopwatch which can be started, stopped and paused at will. This premise was tested in the first experimental chapter, the expected decline in performance was calculated in line with model predictions. The observed deterioration significantly exceeded the calculated predictions indicating that human timing is not akin to that of a ‘stopwatch’ when timing short durations and is incongruent with the predictions of a pacemaker accumulator type mode that can be paused at will. Psychophysical methods have revealed that interval timing conforms to a fundamental property in sensory processing known as Weber’s Law. Lawful relationships such as these are important because they inform and constrain models of human interval timing. The adherence to this property was investigated across a range of durations using two comparable tasks in the following experiment. Although violations across certain durations were observed, these were not mirrored in both the utilised tasks to a statistically significant degree. The results could tentatively be argued to suggest certain constraints on the scalar model albeit a firm conclusion cannot be asserted. The second question pertaining to multimodal processing across a range of tasks and durations, indicative of the underlying architecture of interval timing, (i.e. ‘one clock or many’) was addressed via transfer of learning and correlation in the two final experiments. Perceptual learning and the generalisation to untrained durations and temporal tasks was assessed in the first of these two chapters. Training was observed to improve performance at a few of the practised durations with a more global improvement for one participant across untrained durations. Generalisation to the motor tasks from the perceptual task was observed consistently in two of the longer trained durations for all three participants pointing to a partially shared or overlapping interval timing structure. The next study further addressed some of the dichotomies reported in timing literature, with a key focus on explicit and implicit timing. Particular attention was also bestowed on timing in language: the language task based on phoneme closure duration and not overly reliant on contextual cues was observed to have a significant association with both motor and perceptual timing tasks. The results of the conducted experiments when taken together point to independent mechanisms which nonetheless possess a significant overlap

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

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

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

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?

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

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

A magnetic resonance volumetric study of the temporal lobe structures in depression

Depression is one of the most common psychiatric disorders and is associated with considerable morbidity. In recent years structural-imaging technology has provided an opportunity to examine the brain anatomy in patients with the psychiatric illness. 10 patients of various ages and, as the control group, 16 healthy subjects were examined using the MRI method of neuroimaging. The volumes of the following structures were evaluated in the right and left hemispheres: the superior temporal gyrus, the basolateral temporal area (the region including middle temporal gyrus, inferior temporal gyrus and fusiform gyrus), the parahippocampal gyrus, the hippocampal head, the amygdaloid body and the lateral ventricle. The significant difference between the control group and the group with depression concerned the volume of the temporal horn of the lateral ventricle of both hemispheres. In depressed patients the left temporal horn was 49.8% and the right 38.4% larger in comparison with the control group. In the control group there were significant differences between the left and right hemispheres in the volume of all the structures studied, whereas in the group with depression these difference in volume between the hemispheres concerned only the amygdaloid body and the lateral ventricle

Prolonged head down bed rest-induced inactivity impairs tonic autonomic regulation while sparing oscillatory cardiovascular rhythms in healthy humans.

Background. Physical inactivity represents a major risk for cardiovascular disorders, such as hypertension, myocardial infarction or sudden death; however, underlying mechanisms are not clearly elucidated. Clinical and epidemiological investigations suggest, beyond molecular changes, the possibility of an induced impairment in autonomic cardiovascular regulation. However, this hypothesis has not been tested directly. Methods. Accordingly, we planned a study with noninvasive, minimally intrusive, techniques on healthy volunteers. Participants were maintained for 90 days strictly in bed, 24 h a day, in head-down (S6-) position (HDBR). Physical activity was thus virtually abolished for the entire period of HDBR. We examined efferent muscle sympathetic nerve activity, as a measure of vascular sympathetic control, baroreceptor reflex sensitivity, heart rate variability (assessing cardiovagal regulation), RR and systolic arterial pressure and low-frequency and high-frequency normalized components (as a window on central oscillatory regulation). Measures. were obtained at rest and during simple maneuvers (moderate handgrip, lower body negative pressure and active standing) to assess potential changes in autonomic cardiovascular responsiveness to standard stimuli and the related oscillatory profiles. Results HDBR transiently reduced muscle sympathetic nerve activity,RR,heart ratevariabilityandbaroreceptor reflex sensitivity late during HDBR or early during the recovery phase. Conversely, oscillatory profiles of RR and systolic arterial pressure variability were maintained throughout. Responsiveness to test stimuli was also largely maintained