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Comparing techniques for measuring corticosterone in tadpoles

Current Zoology 2015年第5期61卷 835-845页

作者： Pablo BURRACO Rosa ARRIBAS Saurabh S. KULKARNI Daniel R. BUCHHOLZ ivan gomez-mestre Department of Wetland Ecology Estacion Biologica de Dofiana (EBD-CSIC) C/Americo Vespucio s/n 41092 Sevilla Spain Department of Pediatrics Yale School of Medicine Yale University New Haven CT 0651 USA Department of Biological Sciences University of Cincinnati Cincinnati OH 45221 USA

Glucocorticoids play a key role in mediating stress responses in vertebrates. Corticosterone (CORT) is the main glucocorticoid produced in amphibians, birds, and reptiles, and regulates several metabolic functions. The most common methods for quantifying CORT are competitive binding immunoassays: radioimmunoassay (RIA) and enzyme immunoassay (EIA). RIA has been broadly used since the 1980’s but it requires radioactivity. Commercial EIA kits permit quantifying hormone levels without radioactivity although the requirement for a larger sample volume may be a strong limitation for measurements involving larval amphibians. Here we usedXenopus laevistadpoles to compare the performance of three commonly used procedures for determination of CORT: RIA on a chloroform extract of whole-body homogenate, EIA on plasma, and EIA on supernatant of whole-body homogenate. We treated tadpoles with exogenous CORT at 0, 25, 50, and 100 nM. RIA could distinguish between 0 and 25 nM, and EIA on plasma between 0 and 50 nM, whereas whole-body homogenate EIA only detected significant differences between 0 and 100 nM. Each procedure presents advantages and disadvantages regarding sensitivity, the use of radioactivity, sample size, handling time, and economic cost. RIA is preferred when studying small-bodied animals from which blood samples cannot be obtained. When CORT level differences are intermediate and blood sampling is possible, EIA on plasma is a good non-radioactive alternative. EIA on whole-body homogenates may be useful to assess qualitative changes in CORT levels when considerable differences are expected. Finally, we discuss our findings in the context of previous studies on CORT in amphibians.

关键词：测定方法皮质酮蝌蚪环境影响评估糖皮质激素非放射性酶免疫法两栖动物

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Oscillatory Dynamics of a Spherical Solid in a Liquid in an Axisymmetric Variable Cross Section Channel

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Fluid Dynamics & Materials Processing 2024年第6期20卷 1219-1232页

作者： ivan Karpunin Laboratory of Vibrational Hydromechanics Perm State Humanitarian Pedagogical UniversityPerm614990Russia

The dynamics of a solid spherical body in an oscillating liquid flow in a vertical axisymmetric channel of variable cross section is experimentally *** is shown that the oscillating liquid leads to the generation of intense averaged flows in each of the channel *** intensity and direction of these flows depend on the dimensionless oscillating *** the region of studied frequencies,the dynamics of the considered body is examined when the primary vortices emerging in the flow occupy the whole region in each *** a fixed frequency,an increase in the oscillation amplitude leads to a phase-inclusion holding effect,i.e.,the body occupies a quasi-stationary position in one of the cells of the vertical channel,while oscillating around its average *** is also shown that the oscillating motion of a liquid column generates an averaged force acting on the body,the magnitude of which depends on the properties of the body and its position in the *** quasi-stationary position is determined by the relative density and size of the body,as well as the dimensionless *** behavior of the body as a function of the amplitude and frequency of fluid oscillation and relative size is discussed in *** findings may be used in the future to control the position of a phase inclusion and/or to strengthen mass transfer effects in a channel of variable cross section by means of fluid oscillations.

关键词： Phase inclusion axisymmetric channel variable cross section oscillations dimensionless frequency averaged force viscous boundary layer

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Liquid superlubricity of lubricants containing hydroxyl groups and their aqueous solution under rolling/sliding conditions

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Friction 2024年第1期12卷 164-173页

作者： Tomáš POLÁČEK Petr ŠPERKA ivan KŘUPKA Faculty of Mechanical Engineering Brno University of TechnologyBrno 61669Czech Republic

Macroscale rolling/sliding conditions are in the superlubricity,a little-studied topic so *** purpose of this paper is to examine the formation of elastohydrodynamic lubrication(EHL)films by water-based lubricants(glycerol and polyethylene glycol(PEG)),providing superlubricous *** were carried out on an optical ball-on-disc tribometer under rolling/sliding *** film thickness was measured by the thin film colorimetric interferometry,and the viscosity of liquids was measured by rotational and high-pressure falling body *** results show that tribochemical reactions are not the mandatory reason for friction to reach the superlubricity level when using the water-based *** studied liquids themselves are almost *** the addition of water,the signs of shear thinning behavior disappear even *** conditions for this type of lubricant can be predicted using the known Hamrock–Dowson *** anomaly in the thickness of the lubricants was observed as an abrupt change at certain *** more PEG there is in the lubricant,the higher the thickness at the beginning of the jump.

关键词： macroscale superlubricity super low traction water-based lubricants elastohydrodynamic lubrication(EHL) film thickness

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Applying the Shearlet-Based Complexity Measure for Analyzing Mass Transfer in Continuous-Flow Microchannels

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Fluid Dynamics & Materials Processing 2024年第8期20卷 1743-1758页

作者： Elena Mosheva ivan Krasnyakov Institute of Continuous Media Mechanics UB RAS Perm614013Russia Department of Applied Physics Perm National Research Polytechnic UniversityPerm614990Russia

Continuous-flow microchannels are widely employed for synthesizing various materials,including nanoparticles,polymers,and metal-organic frameworks(MOFs),to name a *** technology allows precise control over reaction parameters,resulting in purer,more uniform,and structurally stable products due to more effective mass transfer ***,continuous-flow synthesis processes may be accompanied by the emergence of spatial convective structures initiating convective *** the one hand,convection can accelerate reactions by intensifying mass *** the other hand,it may lead to non-uniformity in the final product or defects,especially in MOF microcrystal *** ability to distinguish regions of convective and diffusive mass transfer may be the key to performing higher-quality reactions and obtaining purer *** this study,we investigate,for the first time,the possibility of using the information complexity measure as a criterion for assessing the intensity of mass transfer in microchannels,considering both spatial and temporal non-uniformities of liquid’s distributions resulting from convection *** calculate the complexity using shearlet transform based on a local *** contrast to existing methods for calculating complexity,the shearlet transform based approach provides a more detailed representation of local *** analysis involves experimental images illustrating the mixing process of two non-reactive liquids in a Y-type continuous-flow microchannel under conditions of double-diffusive convection *** obtained complexity fields characterize the mixing process and structure formation,revealing variations in mass transfer intensity along the *** compare the results with cases of liquid mixing via a pure diffusive *** analysis,it was revealed that the complexity measure exhibits sensitivity to variations in the type of mass transfer,establishing its feasibility as an ind

关键词： Shearlet analysis complexity measure entropy measure convection microchannels double-diffusive instability

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Three-Dimensional Convection in an Inclined Porous Layer Subjected to a Vertical Temperature Gradient

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Fluid Dynamics & Materials Processing 2024年第9期20卷 1957-1970页

作者： ivan Shubenkov Tatyana Lyubimova Evgeny Sadilov Computational Fluid Dynamics Laboratory Institute of Continuous Media Mechanics UB RASPerm614068Russia Theoretical Physics Department Perm State UniversityPerm614990Russia

In this paper,we study the onset and development of three-dimensional convection in a tilted porous layer saturated with a *** layer is subjected to a gravitational field and a strictly vertical temperature ***,problems of thermal convection in tilted porous media saturated with a liquid are studied by assuming constant different temperatures at the boundaries of the layer,which prevent these systems from supporting conductive(non-convective)*** boundary conditions considered in the present work allow a conductive state and are representative of typical geological *** an earlier work,we carried out a linear stability analysis of the conductive *** was shown that at any layer tilt angles,the most dangerous type of disturbances are longitudinal ***,a non-zero velocity component exists in *** the present work,threedimensional non-linear convection regimes are *** original three-dimensional problem is reduced to two-dimensional one with an analytical expression for the velocity z-component v_(z)=v_(z)(x,y).It is shown that the critical Rayleigh number values obtained through numerical solutions of the obtained 2D problem by a finite difference method for different layer inclination angles,are in a good agreement with those predicted by the linear *** number of convective rolls realized in nonlinear calculations also fits the linear theory predictions for a given cavity *** carried out at low supercriticalities show that a direct bifurcation takes *** increasing supercriticality,no transitions to other convective regimes are *** situation studied in this problem can be observed in oil-bearing rock formations under the influence of a geothermal temperature gradient,where the ensuing fluid convection can affect the distribution of oil throughout the layer.

关键词： Thermal convection inclined layer porous media vertical temperature gradient

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Is Veillonella a unique marker of physical exercise?Commentary on:

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Journal of Sport and Health Science 2024年第5期13卷 682-684页

作者： Viktor Bielik ivan Hric Riadh Hammami Department of Biological and Medical Science Faculty of Physical Education and SportComenius University in BratislavaBratislava 81469Slovakia Department of Molecular Biology Faculty of Natural SciencesComenius University in BratislavaBratislava 84215Slovakia Biomedical Research Center Institute of Clinical and Translational ResearchSlovak Academy of SciencesBratislava 84505Slovakia School of Nutrition Sciences Faculty of Health SciencesUniversity of OttawaOttawaON K1N 6N5Canada Department of Biochemistry Microbiology and ImmunologyFaculty of MedicineUniversity of OttawaOttawaON K1N 6N5Canada

In 2020,Kostic1 published commentary on the bacterial genus Veillonella associated with the interaction between the intestinal microbiota and skeletal *** then,novel perspectives on the bidirectional gut-muscle communication axis have gained a lot of *** purpose of this commentary is to explore some of the challenging issues presented in Scheiman et al.

关键词： skeletal gained

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Interatomic Interaction Models for Magnetic Materials:Recent Advances

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Chinese Physics Letters 2024年第6期41卷 54-66页

作者： Tatiana S.Kostiuchenko Alexander V.Shapeev ivan S.Novikov Emanuel Institute of Biochemical Physics RAS 4 Kosygin StreetMoscow119334Russian Federation Independent investigator

Atomistic modeling is a widely employed theoretical method of computational materials *** has found particular utility in the study of magnetic ***,magnetic empirical interatomic potentials or spinpolarized density functional theory(DFT)served as the primary models for describing interatomic interactions in atomistic simulations of magnetic ***,in recent years,a new class of interatomic potentials known as magnetic machine-learning interatomic potentials(magnetic MLIPs)has *** MLIPs combine the computational efficiency,in terms of CPU time,of empirical potentials with the accuracy of DFT *** this review,our focus lies on providing a comprehensive summary of the interatomic interaction models developed specifically for investigating magnetic *** also delve into the various problem classes to which these models can be ***,we offer insights into the future prospects of interatomic interaction model development for the exploration of magnetic materials.

关键词： materials interaction empirical

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Influence of Methane-Hydrogen Mixture Characteristics on Compressor Vibrations

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Fluid Dynamics & Materials Processing 2024年第5期20卷 1031-1043页

作者： Vladimir Ya.Modorskii ivan E.Cherepanov High Performance Computing Center Perm National Research Polytechnic UniversityPerm614990Russia

A transition to clean hydrogen energy will not be possible until the issues related to its production, transportation,storage, etc., are adequately resolved. Currently, however, it is possible to use methane-hydrogen *** gas can be transported using a pipeline system with the required pressure being maintained by gascompression stations. This method, however, is affected by some problems too. Compressors emergency stopscan be induced by vibrations because in some cases, mechanical methods are not able to reduce the vibrationamplitude. As an example, it is known that a gas-dynamic flow effect in labyrinth seals can lead to increasedvibrations. This paper presents the numerical simulation of rotor oscillations taking into account a gas-dynamicload. The influence of a transported mixture on the oscillatory process is investigated. Mixtures consisting ofmethane and hydrogen in various proportions and an air mixture are considered. The results are discussed forvarious operating pressures and include the rotor motion trajectories and oscillation frequency spectra obtainednumerically. It is shown that the gas mixture composition has a significant effect on the oscillations and theiroccurrence. Hydrogen as a working fluid reduces the vibration amplitude. Operating a compressor with hydrogenleads to a decrease in the resonant frequency, bringing it closer to the operating one. However, the operatingpressure at which maximum oscillations are observed depends slightly on the gas mixture composition.

关键词： Seal stabilities vibration FSI CFD multiphase flows hydrogen

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Witness for resolution: post-conflict quadratic affiliation in semi-free ranging pigs

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Current Zoology 2024年第2期70卷 233-243页

作者： ivan Norscia Edoardo Collarini Carlo Robino Elena Chierto Giada Cordoni Department of Life Sciences and Systems Biology University of TorinoVia Accademia Albertina 1310123 TorinoItaly Department of Public Health Sciences and Pediatric s University of TorinoC.So Galileo Galilei 2210126 TorinoItaly

In social mammals,post-conflict resolution can involve the reunion of former opponents(reconciliation),spontaneous/solicited post-conflict affliation of a third party with either opponent(triadic contacts),and affiliation between other individuals(hereafter bystanders;quadratic contacts).Quadratic contacts-possibly informing complex cognitive abilities-have been neglected in post-conflict *** investi-gated quadratic affliation in semi-free ranging pigs Sus scrofa,at the ethical farm Parva-Domus(Cavagnolo,Italy).Kinship was *** collected behavioral data on adult pigs(n=104)via video recordings(43 h)followed by video *** and anxiety behaviors between bystanders were collected under post-conflict(PC;following a conflict between non-bystanders)and matched-control(MC;no conflict)*** affiliation was present in pigs,as bystanders affliated more in PC than MC,and such affiliation was followed by a decrease in the anxiety behaviors of both the interacting ***,quadratic contacts may be partly aimed at reducing one's own anxiety(intrinsic regulation).Quadratic affiliation was highest between closely related bystanders,which suggests that such affiliation may be most effective when close kin is *** affiliation was lowest after reconciliation and spontaneous triadic *** suggests that direct peacemaking between opponents and spontaneous triadic contacts with close kin may most likely replace quadratic ***,pigs can be influenced by the negative events that affect other pigs-but not themselves-and their response may be modulated by social *** non-random quadratic affiliation may point toward the presence of elements of social appraisal abilities inpigs.

关键词： anxiety reduction emotional regulation reconciliation social appraisal triadic contacts.

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Rock Mass Quality Rating Based on the Multi-Criteria Grey Metric Space

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 2635-2664页

作者： MilošGligoric Zoran Gligoric Saša Jovanovic Suzana Lutovac Dragan Pamucar ivan Jankovic Faculty of Mining and Geology University of BelgradeBelgrade11000Serbia Faculty of Technical Sciences University of PrištinaKosovska Mitrovica38220Serbia Department of Operations Research and Statistics Faculty of Organizational SciencesUniversity of BelgradeBelgrade11000Serbia College of Engineering Yuan Ze UniversityTaoyuan City320315Taiwan

Assessment of rock mass quality significantly impacts the design and construction of underground and open-pit mines from the point of stability and *** study develops the novel Gromov-Hausdorff distance for rock quality(GHDQR)methodology for rock mass quality rating based on multi-criteria grey metric *** usually presents the quality of surrounding rock by classes(metric spaces)with specified properties and adequate interval-grey *** the distance between surrounding rock sample characteristics and existing classes represents the core of this *** Gromov-Hausdorff distance is an especially useful discriminant function,i.e.,a classifier to calculate these distances,and assess the quality of the surrounding *** efficiency of the developed methodology is analyzed using the Mean Absolute Percentage Error(MAPE)*** existing methods,such as the Gaussian cloud method,Discriminant method,Mutation series method,Artificial neural network(ANN),Support vector machine(SVM),Grey wolf optimizer and Support vector classification method(GWO-SVC)and Rock mass rating method(RMR)are used for comparison with the proposed GHDQR *** share of the highly accurate category of 85.71%clearly indicates compliance with actual values obtained by the compared *** results of comparisons showed that the model enables objective,efficient,and reliable assessment of rock mass quality.

关键词： Rock mass rating multi-criteria class metric space interval-grey numbers

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