Chains of Viscoelastic Spheres

Given a chain of viscoelastic spheres with fixed masses of the first and last particles. We raise the question: How to chose the masses of the other particles of the chain to assure maximal energy transfer? The results are compared with a chain of particles for which a constant coefficient of restitution is assumed. Our simple example shows that the assumption of viscoelastic particle properties has not only important consequences for very large systems (see [1]) but leads also to qualitative changes in small systems as compared with particles interacting via a constant restitution coefficient.Comment: 11 pages, 6 figure

Isotopic insights into the early Medieval (600-1100 CE) diet in the Luistari cemetery at Eura, Finland

In this article, we present the results of an isotopic study of diet for the early medieval (Merovingian, Viking, Early Christian) humans buried in the unique Luistari cemetery at Eura (ca. 600-1400 CE), southwestern Finland, the largest cemetery of the region. Isotope analysis was conducted on 37 humans for dentine and bone collagen (delta C-13, delta N-15, and delta S-34), and five of them were also studied using compound-specific nitrogen isotope analysis. Dental enamel and/or bone carbonate delta C-13 values were studied from altogether 65 humans, five cattle, and five sheep/goats. The bone and dentine collagen and carbonate data show that throughout the centuries, freshwater fish was a stable part of the diet for the population. Our results do not show systematic dietary differences between estimated males and females, but differences can be large on the individual level. We also discovered a possible temporal change in the enamel carbonate delta C-13 values that could be related to the increasing role of carbohydrates (e.g., crops) in the diet. Luistari burials are well comparable to contemporary Swedish Viking trading communities like Birka in their higher protein intake. But contrary to the wider Viking network, they do not show the same marine signal.Peer reviewe

Thermoacoustic tomography arising in brain imaging

We study the mathematical model of thermoacoustic and photoacoustic tomography when the sound speed has a jump across a smooth surface. This models the change of the sound speed in the skull when trying to image the human brain. We derive an explicit inversion formula in the form of a convergent Neumann series under the assumptions that all singularities from the support of the source reach the boundary

Криохирургия печени в эксперименте и клинике

The aim of the investigation – to study changes in hepatic tissue resulting from the influence of low temperatures (– 195,8 °C) in experiments and clinic. Hepatic tissue investigations in experiment have been carried out using electron and light microscopy. During the surgery instruments of original design have been used – cryoscalpels and cryodestructors. Experiments have been carried out on 45 sexually mature dogs of both sexes. Animals have been separated into 3 groups. On the first group (consisting of 12 animals), in the acute experiment, there have been studied features of cryoscalpel design characteristics. In the second series of experiment (on 22 dogs) there have been made a comparative study of hepatic resection using cryoultrasonic scalpel and simple surgical scalpel by means of the study of hemorrhage quantity. In 11 cases there have been studied hepatic morphological changes affected by cryoeffect. By the effect of low temperature ice crystals are appeared in hepatic tissue intracellularly and outside the cell, they cause mechanical injury and rupture of hepatic tissue. In 45 days connective tissue elements are formed at the place of cryodestruction. The use of cryoultrasonic scalpel in hepatic resection in the experiment decreases the hemorrhage quantity by 1,26 times as compared to the traditional methods. Positive experimental investigations allowed to use the low temperature with success in clinical practice at 253 patients with different localized hepatic diseases with 13 lethal outcomes (5,1%). Thus, the used cryosurgical technique during surgical operations allows to decrease significantly the hemorrhage, to eliminate parenchymatous bleeding and to prevent relapses of disease both at growths and at parasitic hepatic affection.Цель исследования — изучить изменения, происходящие в ткани печени под действием низкой температуры (–195,8 °С) в эксперименте и клинике. Исследование ткани печени в эксперименте проведены с использованием электронной и световой микроскопии. При выполнении операций применялись инструменты оригинальной конструкции — криоскальпели и криодеструкторы. Эксперименты выполнены на 45 половозрелых собаках обоего пола. Животные были разделены на 3 группы. На первой группе, состоящей из 12 животных, в остром опыте изучались особенности конструктивных особенностей криоскальпелей, во второй серии опытов (на 22 собаках) проводилось сравнительное изучение резекций печени с помощью криоультразвукового скальпеля и простого хирургического путем изучения величины кровопотери и в 11 случаях изучались морфологические изменения со стороны ткани печени на криовоздействие. Под действием низкой температуры в ткани печени внутрицеллюлярно и за пределами клетки образуются кристаллы льда, которые вызывают механическое повреждение и разрыв ткани печени, через 45 сут в месте криодеструкции образуются элементы соединительной ткани. Применение криоультразвукового скальпеля во время резекции печени в эксперименте снижает величину кровопотери в 1,26 раза по сравнению с традиционными методами.* Положительные экспериментальные исследования позволили с успехом применить низкую температуру в клинической практике у 253 больных с различными очаговыми заболеваниями печени с 13 летальными исходами (5,1%). Таким образом, применяемая криохирургическая техника позволяет во время оперативных вмешательств значительно снизить кровопотерю, устранить паренхиматозное кровотечение и предотвратить рецидивы заболевания как при опухолях, так и при паразитарном поражении печени

Money as a Polycontextual Value and Means of SelfIdentification of a Modern Person: Traditional vs Virtual

The article examines the axiological psycho-philosophical understanding of the phenomenon of money and its value role in modern society. The traditional and virtual context of the representation of the money phenomenon is considered. Following the ideas of G. Simmel, the authors consider money not only as a purely economic, but also a psycho-philosophical, cultural and social phenomenon. Money appears as a result of cultural development of the world and gradually forms a monetary culture as a space of economic and social interaction of people. Under the influence of the monetary culture of one or another historical period, the character of a person’s economic activity, values and life orientations are formed. Modern money culture is often called financial civilization. Peculiarities of modern monetary culture are studied, its main features and problems are determined in the article. The problem of the peculiarities of the constructive and destructive attitude of the individual towards money is identified; a psycho-philosophical and cultural-identification typology of people is described, which is based on clinical observations and interpreted through the prism of psychoanalytic theory. The concept of money is highlighted from the standpoint of a socialpsychological approach. The theoretical foundations of money’s influence on the decision-making process and human behavior are also revealed

Nonlinear vortex light beams supported and stabilized by dissipation

We describe nonlinear Bessel vortex beams as localized and stationary solutions with embedded vorticity to the nonlinear Schr\"odinger equation with a dissipative term that accounts for the multi-photon absorption processes taking place at high enough powers in common optical media. In these beams, power and orbital angular momentum are permanently transferred to matter in the inner, nonlinear rings, at the same time that they are refueled by spiral inward currents of energy and angular momentum coming from the outer linear rings, acting as an intrinsic reservoir. Unlike vortex solitons and dissipative vortex solitons, the existence of these vortex beams does not critically depend on the precise form of the dispersive nonlinearities, as Kerr self-focusing or self-defocusing, and do not require a balancing gain. They have been shown to play a prominent role in "tubular" filamentation experiments with powerful, vortex-carrying Bessel beams, where they act as attractors in the beam propagation dynamics. Nonlinear Bessel vortex beams provide indeed a new solution to the problem of the stable propagation of ring-shaped vortex light beams in homogeneous self-focusing Kerr media. A stability analysis demonstrates that there exist nonlinear Bessel vortex beams with single or multiple vorticity that are stable against azimuthal breakup and collapse, and that the mechanism that renders these vortexes stable is dissipation. The stability properties of nonlinear Bessel vortex beams explain the experimental observations in the tubular filamentation experiments.Comment: Chapter of boo

Neurobehavioral consequences of chronic intrauterine opioid exposure in infants and preschool children: a systematic review and meta-analysis

<b>Background</b><p></p> It is assumed within the accumulated literature that children born of pregnant opioid dependent mothers have impaired neurobehavioral function as a consequence of chronic intrauterine opioid use.<p></p> <b>Methods</b><p></p> Quantitative and systematic review of the literature on the consequences of chronic maternal opioid use during pregnancy on neurobehavioral function of children was conducted using the Meta-analysis of Observational Studies in Epidemiology (MOOSE) and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. We searched Cinahl, EMBASE, PsychINFO and MEDLINE between the periods of January 1995 to January 2012.<p></p> <b>Results</b><p></p> There were only 5 studies out of the 200 identified that quantitatively reported on neurobehavioral function of children after maternal opioid use during pregnancy. All 5 were case control studies with the number of exposed subjects within the studies ranging from 33–143 and 45–85 for the controls. This meta-analysis showed no significant impairments, at a non-conservative significance level of p < 0.05, for cognitive, psychomotor or observed behavioural outcomes for chronic intra-uterine exposed infants and pre-school children compared to non-exposed infants and children. However, all domains suggested a trend to poor outcomes in infants/children of opioid using mothers. The magnitude of all possible effects was small according to Cohen’s benchmark criteria.<p></p> <b>Conclusions</b><p></p> Chronic intra-uterine opioid exposed infants and pre-school children experienced no significant impairment in neurobehavioral outcomes when compared to non-exposed peers, although in all domains there was a trend to poorer outcomes. The findings of this review are limited by the small number of studies analysed, the heterogenous populations and small numbers within the individual studies. Longitudinal studies are needed to determine if any neuropsychological impairments appear after the age of 5 years and to help investigate further the role of environmental risk factors on the effect of ‘core’ phenotypes

The structure and evolution of M51-type galaxies

We discuss the integrated kinematic parameters of 20 M51-type binary galaxies. A comparison of the orbital masses of the galaxies with the sum of the individual masses suggests that moderately massive dark halos surround bright spiral galaxies. The relative velocities of the galaxies in binary systems were found to decrease with increasing relative luminosity of the satellite. We obtained evidence that the Tully-Fisher relation for binary members could be flatter than that for local field galaxies. An enhanced star formation rate in the binary members may be responsible for this effect. In most binary systems, the direction of orbital motion of the satellite coincides with the direction of rotation of the main galaxy. Seven candidates for distant M51-type objects were found in the Northern and Southern Hubble Deep Fields. A comparison of this number with the statistics of nearby galaxies provides evidence for the rapid evolution of the space density of M51-type galaxies with redshift Z. We assume that M51-type binary systems could be formed through the capture of a satellite by a massive spiral galaxy. It is also possible that the main galaxy and its satellite in some of the systems have a common cosmological origin.Comment: 8 pages, 4 figures, to be published in Astronomy Letter