ETEKOS experimental ecological system

The problem of changes in the ecology resulting, for example, in increases in water temperature because of discharges from large thermal power plants is considered. An experiment creating a model of such an ecological system is described

Use of Levosimendan in Cardiac Anesthesiology

The authors consider the main aspects of the rational use of the novel inotropic drug levosimendan in cardiosurgical patients on the basis of the results of the trials described in the literature and on their own findings in this review. The purpose of the analysis made was to provide a rationale for the effective use of this drug. The review shows the role of the ultrasound indicator left ventricular ejection fraction, the prognostic scale EuroSCORE, and the natriuretic peptides NT-proBNP and BNP in defining indications for levosimendan administration for preoperative preparation. There are original data on the lower level of the natriuretic peptides due to levosimendan therapy. The target hemodynamic monitoring values indicating that it is essential to use levosimendan in postperfusion heart failure are discussed. It is shown that it is expedient to use levosimendan simultaneously with traditional medical measures, by taking into account the pharmacokinetic features of a calcium sensitizer. The problem of levosimendan readministration in patients operated on the heart as well is stated. That there are no clear algorithms for repeated use of the drug is shown. At the same time, possible options of this therapy in different clinical situations are given. Key words: levosimendan, cardiosurgery, heart failure

Применение левосимендана в кардиоанестезиологии

The authors consider the main aspects of the rational use of the novel inotropic drug levosimendan in cardiosurgical patients on the basis of the results of the trials described in the literature and on their own findings in this review. The purpose of the analysis made was to provide a rationale for the effective use of this drug. The review shows the role of the ultrasound indicator left ventricular ejection fraction, the prognostic scale EuroSCORE, and the natriuretic peptides NT-proBNP and BNP in defining indications for levosimendan administration for preoperative preparation. There are original data on the lower level of the natriuretic peptides due to levosimendan therapy. The target hemodynamic monitoring values indicating that it is essential to use levosimendan in postperfusion heart failure are discussed. It is shown that it is expedient to use levosimendan simultaneously with traditional medical measures, by taking into account the pharmacokinetic features of a calcium sensitizer. The problem of levosimendan readministration in patients operated on the heart as well is stated. That there are no clear algorithms for repeated use of the drug is shown. At the same time, possible options of this therapy in different clinical situations are given. Key words: levosimendan, cardiosurgery, heart failure.В настоящем обзоре на основе литературных и собственных исследований рассмотрены основные аспекты рационального использования нового инотропного препарата — левосимендана у кардиохирургических больных. Цель проведенного анализа — обоснование принципов эффективного назначения этого лекарственного средства. Обозначена роль ультразвукового параметра — фракции изгнания левого желудочка, прогностической шкалы EuroSCORE, натрийуретических пептидов (NT-proBNP и BNP) для определения показаний к введению левоси-мендана с целью предоперационной подготовки. Продемонстрированы оригинальные данные о снижении уровня натрийуретических пептидов (НУП) в связи с терапией левосименданом. Обсуждены «целевые» показатели ге-модинамического мониторинга, указывающие на необходимость назначения препарата при постперфузионной сердечной недостаточности. Показана целесообразность назначения левосимендана одновременно с проведением традиционных лечебных мер, учитывая фармакокинетические особенности «кальциевого сенситайзера». Сформулирована проблема повторного введения левосимендана, в том числе у больных, оперированных на сердце. Констатировано отсутствие четких алгоритмов неоднократного назначения препарата. Вместе с тем, приведены возможные варианты такой терапии в различных клинических ситуациях. Ключевые слова: левосимендан, кардиохирургия, сердечная недостаточность

Visual Laterality of Calf–Mother Interactions in Wild Whales

Behavioral laterality is known for a variety of vertebrate and invertebrate animals. Laterality in social interactions has been described for a wide range of species including humans. Although evidence and theoretical predictions indicate that in social species the degree of population level laterality is greater than in solitary ones, the origin of these unilateral biases is not fully understood. It is especially poorly studied in the wild animals. Little is known about the role, which laterality in social interactions plays in natural populations. A number of brain characteristics make cetaceans most suitable for investigation of lateralization in social contacts.) in the greatest breeding aggregation in the White Sea. Here we show that young calves (in 29 individually identified and in over a hundred of individually not recognized mother-calf pairs) swim and rest significantly longer on a mother's right side. Further observations along with the data from other cetaceans indicate that found laterality is a result of the calves' preference to observe their mothers with the left eye, i.e., to analyze the information on a socially significant object in the right brain hemisphere.Data from our and previous work on cetacean laterality suggest that basic brain lateralizations are expressed in the same way in cetaceans and other vertebrates. While the information on social partners and novel objects is analyzed in the right brain hemisphere, the control of feeding behavior is performed by the left brain hemisphere. Continuous unilateral visual contacts of calves to mothers with the left eye may influence social development of the young by activation of the contralateral (right) brain hemisphere, indicating a possible mechanism on how behavioral lateralization may influence species life and welfare. This hypothesis is supported by evidence from other vertebrates

Fastloc-GPS reveals daytime departure and arrival during long-distance migration and the use of different resting strategies in sea turtles

Determining the time of day that animals initiate and end migration, as well as variation in diel movement patterns during migration, provides insights into the types of strategy used to maximise energy efficiency and ensure successful completion of migration. However, obtaining this level of detail has been difficult for long-distance migratory marine species. Thus, we investigated whether the large volume of highly accurate locations obtained by Argos-linked Fastloc-GPS transmitters could be used to identify the time of day that adult green (n = 8 turtles, 9487 locations) and loggerhead (n = 46 turtles, 47,588 locations) sea turtles initiate and end migration, along with potential resting strategies during migration. We found that departure from and arrival at breeding, stopover and foraging sites consistently occurred during the daytime, which is consistent with previous findings suggesting that turtles might use solar visual cues for orientation. Only seven turtles made stopovers (of up to 6 days and all located close to the start or end of migration) during migration, possibly to rest and/or refuel; however, observations of day versus night speed of travel indicated that turtles might use other mechanisms to rest. For instance, turtles travelled 31% slower at night compared to day during their oceanic crossings. Furthermore, within the first 24 h of entering waters shallower than 100 m towards the end of migration, some individuals travelled 72% slower at night, repeating this behaviour intermittently (each time for a one-night duration at 3–6 day intervals) until reaching the foraging grounds. Thus, access to data-rich, highly accurate Argos-linked Fastloc-GPS provided information about differences in day versus night activity at different stages in migration, allowing us, for the first time, to compare the strategies used by a marine vertebrate with terrestrial land-based and flying species

ANN-based model for predicting the bearing capacity of strip footing on multi-layered cohesive soil

Copyright © 2008 Elsevier Ltd All rights reserved.In reality, footings are most likely to be founded on multi-layered soils. The existing methods for predicting the bearing capacity of 4-layer up to 10-layer cohesive soil are inaccurate. This paper aims to develop a more accurate bearing capacity prediction method based on multiple regression methods and multi-layer perceptrons (MLPs), one type of artificial neural networks (ANNs). Predictions of bearing capacity from the developed multiple regression models and MLP in tractable equations form are obtained and compared with the value predicted using traditional methods. The results indicate ANNs are able to predict accurately the bearing capacity of strip footing and outperform the existing methods. © 2008 Elsevier Ltd. All rights reserved.Y.L. Kuo, M.B. Jaksa, A.V. Lyamin and W.S. Kaggwahttp://www.elsevier.com/wps/find/journaldescription.cws_home/405893/description#descriptio

Explosion propagation in inert porous media

Porous media are often used in flame arresters because of the high surface area to volume ratio that is required for flame quenching. However, if the flame is not quenched, the flow obstruction within the porous media can promote explosion escalation, which is a well-known phenomenon in obstacle-laden channels. There are many parallels between explosion propagation through porous media and obstacle-laden channels. In both cases, the obstructions play a duel role. On the one hand, the obstruction enhances explosion propagation through an early shear-driven turbulence production mechanism and then later by shock–flame interactions that occur from lead shock reflections. On the other hand, the presence of an obstruction can suppress explosion propagation through momentum and heat losses, which both impede the unburned gas flow and extract energy from the expanding combustion products. In obstacle-laden channels, there are well-defined propagation regimes that are easily distinguished by abrupt changes in velocity. In porous media, the propagation regimes are not as distinguishable. In porous media the entire flamefront is affected, and the effects of heat loss, turbulence and compressibility are smoothly blended over most of the propagation velocity range. At low subsonic propagation speeds, heat loss to the porous media dominates, whereas at higher supersonic speeds turbulence and compressibility are important. This blending of the important phenomena results in no clear transition in propagation mechanism that is characterized by an abrupt change in propagation velocity. This is especially true for propagation velocities above the speed of sound where many experiments performed with fuel–air mixtures show a smooth increase in the propagation velocity with mixture reactivity up to the theoretical detonation wave velocity

Slope stability charts for two-layered purely cohesive soils based on finite-element limit analysis methods

Stability charts for soil slopes, first produced in the first half of the twentieth century, continue to be used extensively as design tools, and draw the attention of many investigators. This paper uses finite-element upper and lower bound limit analysis to assess the short-term stability of slopes in which the slopematerial and subgrade foundation material have two distinctly different undrained strengths. The stability charts are proposed, and the exact theoretical solutions are bracketed to within 4.2% or better. In addition, results from the limit-equilibrium method (LEM) have been used for comparison. Differences of up to 20% were found between the numerical limit analysis and LEM solutions. It also shown that the LEM sometimes leads to errors, although it is widely used in practice for slope stability assessments