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Detailed Investigation of Human Galectins -1 and -3 by employing selectively deoxyfluorinated N-acetyllactosamines
Kurfiřt, Martin
2023 - anglický
This work is focused on a detailed investigation of supramolecular recognition events between human galectins -1 and -3 and monodeoxyfluorinated N-acetyllactosamine probes, which were previously prepared in our laboratory. The recognition was studied using a combination of X-ray crystallography, isothermal titration calorimetry and several advanced NMR techniques, such as 19F T2-filter, 1H–1H STD, 1H–15N CSP or 19F EXSY. These techniques provided insight into the thermodynamics and kinetics of recognition and enabled us to uncover of subtle differences between both investigated galectins. Such differences could be potentially exploited in the selective targeting of individual galectins with important implications for the galectins-focused\npharmaceutic industry.
Klíčová slova:
galectins; NMR techniques; pharmaceutic industry
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Detailed Investigation of Human Galectins -1 and -3 by employing selectively deoxyfluorinated N-acetyllactosamines
This work is focused on a detailed investigation of supramolecular recognition events between human galectins -1 and -3 and monodeoxyfluorinated N-acetyllactosamine probes, which were previously ...
The electrodiffusional theory for wall shear stress measurement by a two-strip probe: a journey to near-wall region hydrodynamics
Harrandt, Václav
2023 - anglický
This contribution deals with a new theory describing mass transport in the vicinity of the measuring two-segment strip probe. Analytical formulas for the mass transfer coefficients of the front and the rear electrodes were derived. At the same time, the correctness of these formulas was confirmed by the numerical solution of the convectiondiffusion transport equation.
Klíčová slova:
transport phenomena; electrodes; wall shear stress
Plné texty jsou dostupné v digitálním repozitáři NUŠL
The electrodiffusional theory for wall shear stress measurement by a two-strip probe: a journey to near-wall region hydrodynamics
This contribution deals with a new theory describing mass transport in the vicinity of the measuring two-segment strip probe. Analytical formulas for the mass transfer coefficients of the front and ...
(NE)ZÁVISLOST AKTIVACE AEROSOLU NA POZICI V OBLAKU
Zíková, Naděžda; Pokorná, Petra; Sedlák, Pavel; Sokol, Zbyněk; Ždímal, Vladimír
2023 - český
Na hoře Milešovka v České republice bylo provedeno pět in situ kampaní zaměřených na interakci aerosolu s oblakem, jejichž cílem bylo získat více informací o aktivaci aerosolu a její závislosti na meteorologických parametrech, především vertikální rychlosti proudění vzduchu a poloze v oblaku. Aktivovaná frakce byla vypočtena z rozdílu koncentrací naměřených za vtokem celého vzduchu a za vtokem PM2,5 . Obsah kapalné vody (LWC) byl vypočten z dohlednosti, poloha základny mraku byla odhadnuta z údajů ceilometru. Vertikální rychlost proudění vzduchu byla odhadnuta z radarového měření oblačnosti. Nebyla zjištěna žádná silná závislost mezi dohledností a vertikální rychlostí, což naznačuje, že oblačnost na stanici je většinou advekčního nebo inverzního původu. Viditelnost i LWC závisí na poloze v oblaku, přičemž nejvyšší hodnoty LWC byly zjištěny, když se stanice nacházela ve výšce 100 až 400 m nad základnou oblaku, nezávisle na skutečné hodnotě. Five in situ campaigns focused on aerosol-cloud interactions were conducted at Mount Milešovka in the Czech Republic to gain more insight into aerosol activation and its dependence on meteorological parameters, mainly vertical air velocity and position within the cloud. The activated fraction was calculated from the difference of concentrations measured behind the whole air inlet and the PM2.5 inlet. The liquid water content (LWC) was calculated from visibility, cloud base position was estimated from ceilometer data. Vertical air velocity was estimated from cloud radar. No strong dependence was found between visibility and vertical velocity, suggesting that the clouds at the station are mostly of advection or inversion origin. Both visibility and LWC depend on the position within the cloud, with the highest LWC values found when the station was between 100 and 400 m above the cloud base, independently of the actual value.
Klíčová slova:
atmospheric aerosols; activation; cloud base
Plné texty jsou dostupné v digitálním repozitáři NUŠL
(NE)ZÁVISLOST AKTIVACE AEROSOLU NA POZICI V OBLAKU
Na hoře Milešovka v České republice bylo provedeno pět in situ kampaní zaměřených na interakci aerosolu s oblakem, jejichž cílem bylo získat více informací o aktivaci aerosolu a její závislosti na ...
Direct construction of reciprocal mass matrix and higher order fininite element method
Cimrman, Robert; Kolman, Radek; González, J. A.; Park, K. C.
2023 - anglický
When solving dynamical problems of computational mechanics, such as contact-impact problems or cases involving complex structures under fast loading conditions, explicit time-stepping algorithms are usually preferred over implicit ones. The explicit schemes are normally combined with the lumped (diagonal) mass matrix so that the calculations are efficient and moreover dispersion errors in wave propagation are partially eliminated. As an alternative to lumping with advantageous properties, the reciprocal mass matrix is an inverse mass matrix that has the same sparsity structure as the original consistent mass matrix, preserves the total mass, captures well the desired frequency spectrum and leads thus to efficient and accurate calculations. In the contribution we comment on the usability of the reciprocal mass matrix in connection with higher order FEM.
Klíčová slova:
higher-order finite element method; reciprocal mass matrix; transient problems; explicit time integration; lumping process
Dokument je dostupný na externích webových stránkách.
Direct construction of reciprocal mass matrix and higher order fininite element method
When solving dynamical problems of computational mechanics, such as contact-impact problems or cases involving complex structures under fast loading conditions, explicit time-stepping algorithms are ...
Reduced basis solver for stochastic Galerkin formulation of Darcy flow with uncertain material parameters
Béreš, Michal
2023 - anglický
In this contribution, we present a solution to the stochastic Galerkin (SG) matrix equations coming from the Darcy flow problem with uncertain material coefficients in the separable form. The SG system of equations is kept in the compressed tensor form and its solution is a very challenging task. Here, we present the reduced basis (RB) method as a solver which looks for a low-rank representation of the solution. The construction of the RB consists of iterative expanding of the basis using Monte Carlo sampling. We discuss the setting of the sampling procedure and an efficient solution of multiple similar systems emerging during the sampling procedure using deflation. We conclude with a demonstration of the use of SG solution for forward uncertainty quantification.
Klíčová slova:
stochastic Galerkin method; reduced basis method; Monte Carlo method; deflated conjugate gradient method
Dokument je dostupný na externích webových stránkách.
Reduced basis solver for stochastic Galerkin formulation of Darcy flow with uncertain material parameters
In this contribution, we present a solution to the stochastic Galerkin (SG) matrix equations coming from the Darcy flow problem with uncertain material coefficients in the separable form. The SG ...
Numerical realization of the Bayesian inversion accelerated using surrogate models
Bérešová, Simona
2023 - anglický
The Bayesian inversion is a natural approach to the solution of inverse problems based on uncertain observed data. The result of such an inverse problem is the posterior distribution of unknown parameters. This paper deals with the numerical realization of the Bayesian inversion focusing on problems governed by computationally expensive forward models such as numerical solutions of partial differential equations. Samples from the posterior distribution are generated using the Markov chain Monte Carlo (MCMC) methods accelerated with surrogate models. A surrogate model is understood as an approximation of the forward model which should be computationally much cheaper. The target distribution is not fully replaced by its approximation. Therefore, samples from the exact posterior distribution are provided. In addition, non-intrusive surrogate models can be updated during the sampling process resulting in an adaptive MCMC method. The use of the surrogate models significantly reduces the number of evaluations of the forward model needed for a reliable description of the posterior distribution. Described sampling procedures are implemented in the form of a Python package.
Klíčová slova:
Bayesian inversion; delayed-acceptance Metropolis-Hastings; Markov chain Monte Carlo; surrogate model
Dokument je dostupný na externích webových stránkách.
Numerical realization of the Bayesian inversion accelerated using surrogate models
The Bayesian inversion is a natural approach to the solution of inverse problems based on uncertain observed data. The result of such an inverse problem is the posterior distribution of unknown ...
Influence of recreational activities on the distribution of forest wild boar rooting
Drimaj, J.; Balková, M.; Špoula, J.; Kamler, J.; Mikulka, O.; Plhal, R.; Homolka, Miloslav
2023 - anglický
The wild boar is a widely distributed and locally very numerous animal. The same is true in the conditions of Central Europe. Outside the growing season, it concentrates in forests, where it also actively searches for food sources. During this activity, it disturbs the soil surface, thereby significantly affecting the dynamics of the ecosystem. From an economic point of view, it limits the natural renewal of tree species, but from an ecological point of view, it changes habitat conditions and thus helps to increase biodiversity. Factors influencing the distribution of rooting across forest stands may be different. In this paper, we focused on the human factor and its influence on the rooting activity of wild boar in the Hodonínská Dúbrava, National natural monuments.
Klíčová slova:
animal activity; disturbance; diversity; soil surface; wildlife
Dokument je dostupný na externích webových stránkách.
Influence of recreational activities on the distribution of forest wild boar rooting
The wild boar is a widely distributed and locally very numerous animal. The same is true in the conditions of Central Europe. Outside the growing season, it concentrates in forests, where it also ...
Dynamics of a cantilever beam with piezoelectric sensor: Experimental study
Kolman, Radek; Kylar, Jaromír; Kotek, Vojtěch; Cimrman, Robert; Musil, Ladislav
2023 - anglický
Online and real-time sensing and monitoring of the health state of complex structures, such as air-craft and critical parts of power stations, is an essential part of the research in dynamics. Several types of sensors are used for sensing dynamic responses and monitoring response changes during the operation of critical parts of complex systems. The piezoelectric (PZ) materials belong to one group of electroactive materials, which transform mechanical deformation into an electrical response. For example, PZ ceramics or PVDF foils are employed for online sensing of the time history of mechanical deformation. Experimentally obtained response of a cantilever beam structure with a glued PZ sensor is the case of interest in this contribution. During the transient problem of the beam loaded by suddenly interrupted load due to the weight of a mass at the end of the beam, the time history of normal velocity at a point on the beam surface has been measured by a laser vibrometer and parallely, the output voltage on the PZ sensor has been measured by an electric device. The experimental data in the case of the first eigen-frequency is in good agreement with the value given by the formulae from the theoretical modeling of free vibration of a linear beam.
Klíčová slova:
dynamics of beam-like structure; piezo-electric material; sensing of dynamic response; structural Health Monitoring; laser vibrometer measurement
Dokument je dostupný na externích webových stránkách.
Dynamics of a cantilever beam with piezoelectric sensor: Experimental study
Online and real-time sensing and monitoring of the health state of complex structures, such as air-craft and critical parts of power stations, is an essential part of the research in dynamics. Several ...
On a stepladder model walking (with and without a decorator)
Polach, P.; Prokýšek, R.; Papáček, Štěpán
2023 - anglický
This work is related to our previous studies on underactuated biped robot models and has been motivated by the need to implement the previously developed sensor and control algorithms for the real-time movement of the laboratory walking robot, designed and built at the Department of Control Theory of the Institute of Information Theory and Automation of the Czech Academy of Sciences [1, 6, 7]. Underactuated biped robots with an upper body form a subclass of legged robots, see, e.g., [4] for a review on the control of underactuated mechanical systems and [2] for a study of an asymptotically stable walking for biped robots. It is obvious that in general, the walking control of underactuated walking robots is a more challenging problem than walking control of fully actuated walking robots. As follows, we examine the well-known mechanical system of the stepladder model with and without a decorator, whose role is substituted by an external inertial force according to the D’Alembert principle. It is well known, that stepladder walking is possible due to the periodic movement (pendulating) of an operator – decorator1 The rigorous dynamical analysis of stable cyclic walking of a class of stepladder models is presented in the next section.
Klíčová slova:
Underactuated biped robot models; Control algorithms; Legged robots
Dokument je dostupný na externích webových stránkách.
On a stepladder model walking (with and without a decorator)
This work is related to our previous studies on underactuated biped robot models and has been motivated by the need to implement the previously developed sensor and control algorithms for the ...
Forest springs, a safe source of drinking water?
Mikuška, Pavel; Alexa, Lukáš; Kouřilová, S.; Cigánková, Hana; Křůmal, Kamil; Itterheimová, Petra; Kubáň, Petr; Matoušek, Tomáš; Barešová, Magdalena; Pivokonský, Martin
2023 - anglický
Water from 25 forest springs was characterized for basic physical parameters and chemical and bacteriological composition. Chemical composition was mostly within limits for drinking water, but bacteriological results indicate faecal pollution of water in majority studied springs.
Klíčová slova:
spring; forest; chemical pollution; bacteriological contamination
Plné texty jsou dostupné v digitálním repozitáři Akademie Věd.
Forest springs, a safe source of drinking water?
Water from 25 forest springs was characterized for basic physical parameters and chemical and bacteriological composition. Chemical composition was mostly within limits for drinking water, but ...
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