The middle atmosphere transport is mostly controlled by a large-scale meridional circulation, namely the Brewer-Dobson circulation. In this thesis, climatology and variability of the Brewer-Dobson circulation and the middle atmosphere has been analysed using the Canadian Middle Atmosphere Model (CMAM30-Ext). A number of key variables are used including the age of air, residual velocities, residual stream function, temperature and zonal wind. The analysis of the climatology of the age of air shows, in particular, that young air gets generated near the tropical tropopause, which then travels poleward. The residual stream function shows that the Brewer-Dobson circulation dominates the winter hemispheres around the solstices and becomes nearly symmetrical, with respect to the equator, around the equinoxes. The empirical orthogonal function analysis is applied to explore the modes of variability in the middle atmosphere. The analysis identifies, in particular, the semi-annual oscillation, the quasi-biennial oscillation with moderate explained variance compared to the variance explained by the annual cycle. In addition, the analysis also reveals the emergence of the solar cycle. Powered by TCPDF (www.tcpdf.org)

The master thesis studies the impact of the entropy gradient on the vorticity of ve- locity field, particularly by applying the linear momentum balances. These balances are formulated for Thermo-viscous fluids (later fluids) and Thermo-viscous-elastic ma- terial (later solids) with the other balances (energy, mass, etc.). In order to derive these balances, the Classical continuum mechanics approach is used along with the respec- tive Variational principles. The thesis emphasizes the Variational principles applica- tion representing the modification of the Bateman principle [Bat29] and its comparison with the Classical approach, linked to the L. Crocco work [Cro37], particularly in the case of vorticity generation. It is pointed that by the definition of the dissipative en- tropy sdis a harmony of both approaches can be achieved and that, in the case of an appropriate limit, the direct effect of the entropy gradient on the vorticity of velocity field can be demonstrated. By applying this conclusion the relationship between the change of circulation among a closed curve and released heat on the given geometry is indicated.

Hypoxic pulmonary vasoconstriction (HPV) is a local physiological mechanism in lungs that optimalises blood oxygenation during alveolar hypoxia. Arterioles in the affected region increase flow resistance which redirects blood to better ventilated parts of the lung. During global hypoxia - e.g. in high altitude or in chronic pulmonary illnessess - this mechanism doesn't work, as the blood cannot be redirected elsewhere. The pressure in pulmonary artery rises which leads to right heart hypertrophy and ultimately to cor pulmonale. This mechanism has been studied for decades, but specific signalling pathways still lack full description and therapeutical solutions are not available. This thesis offers description of selected properties of pulmonary circulation and patophysiological context of pulmonary hypertension, introduces the reader to HPV localization and signalization, and discusses its most important steps from decreased oxygen availability to vessel constriction. The practical part of this work explores Succinate dehydrogenase (SDH) - complex coupling Kreb's cycle to electron transport chain - as a primary detection site of hypoxia in pulmonary artery smooth muscle cells. We decided to test this hypothesis in isolated rat lungs by measuring if malonate (SDH inhibitor) causes vasoconstriction as...

Circulating cell-free DNA (cfDNA) and its tumour-derived circulating tumour DNA (ctDNA) fraction are considered an innovative prognostic and predictive biomarker in oncological diagnostics. Many studies have demonstrated higher levels of cfDNA concentration and integrity, as an indicator of the amount of ctDNA in cfDNA, in body fluids from patients with cancer diseases in comparison with healthy individuals, which suggest its potential as an effective biomarker for monitoring of the tumour dynamics. This study focused on optimisation and validation of measurement methods later used for analysis of cfDNA concentration and integrity in blood samples from patients with four different solid cancers. Two different commercial isolation kits have been tested in plasma and serum samples. Quantitative real-time polymerase reaction (qPCR) and PicoGreen dsDNA assay were optimized to effectively quantify low concentrations of cfDNA, subsequently compared to each other and to droplet digital PCR assay tested on selected samples. The concentration and integrity of cfDNA from plasma samples of breast, ovarian, colorectal and pancreatic cancer patients were evaluated. Higher amounts of cfDNA were obtained by the QIAamp Circulating Nucleic Acid isolation kit (Qiagen) in comparison to Plasma/Serum Cell-Free...

Historically unprecedented environmental change in the Arctic ecosystems is often given into the context of its past and possible future development. In the region where instrumental meteorological observations are scarce archives need to be investigated in order to address this issues. The comprehensive synthesis one of the archives: long-live circumpolar evergreen Juniperus communis L. shrub is presented here. 20 individuals from southwest Greenland were investigated at the cell anatomy level to understand the ecology of the species and unhide its potential for environmental and climate reconstructions. The findings are as follows: i) Stop of exponential cross-sectional conduit-lumen widening with increasing age is in contrast with conduit-lumen nature of trees. This indicates that shrubs do not need to saturate their water and nutrient demands via traits of classical hydraulic conductivity law but rather developed different mechanisms. Extreme weather conditions result in prostrate growth form. However, different weather factors probably influence shrub growth differently: While snow and wind act mechanically (a), temperature influences the form of growth physiologically (b). a) So long as the young shrub stem has high resilience to bend back to an upright position after snow melt and so long as it can withstand the wind during the vegetation season it most likely grows upright and the conduit-lumens widen. b) Temperature, resp. freeze-thaw events are responsible for the shrubs preference of safety (finite size of conduit-lumens) over hydraulic efficiency, thus not allowing for more primary growth. All of these (and other) factors are apparently working together and the transition of vertical to more horizontal growth is gradual. As a consequence, the conduit-lumen sizes may not have to be further increased (due to ecophysiological restrictions possibly also must not) because water is no longer transported against gravity. ii) Observed age/growth trend has to be taken into consideration for further employment of the wood anatomical parameter in paleoenvironmental studies. That is, shrub cell parameters can only be used for this purposes if correctly detrended. This allows for more accurate as well as longer reconstructions because youth trend was often neglected in reconstructions based on shrub annual-rings. iii) The south-western Greenland Ice-Sheet (GrIS) melt rates reconstruction is presented for the whole 20th century. This part of GrIS is considered as the most active. According to the presented reconstruction current GrIS melt rates are not uncommon for the last century being comparable to first decades of 20th century. This finding is particularly important contribution to the debate on Atlantic meridional overturning circulation (AMOC). Too high fresh water inputs into the Northern Atlantic from GrIS melting may slow down or even stop the AMOC which would result in more continental climate in Europe. Presented results indicate that this threshold lies higher than observed current melt rates of GrIS. Fascinating Juniperus comunnis species has shown to be able to address many ecological as well as environmental open questions and due to its longevity and abundant distribution has a great potential to become an important player in the Arctic research.

This master’s thesis deals with boundary vorticity element method for 2D fluid flow. The aim of this work is to program this method with continuous vorticity lay-out and to validate method with various boundary conditions. The computed results are presented in this work. Advantages and disadvantages of each one boundary condition are pointed out. New one boundary condition for boundary vorticity element method is applied in this thesis.

The diploma thesis is concerned with switching of vortex circulation in magnetic nanodisks. The results of micromagnetic simulations of hysteresis loops of individual disks with different degrees of asymmetry are presented. The influence of geometric asymmetry of the disk on the shape of the hysteresis loop is discussed as well as switching of vortex circulation in asymmetric nanodisks by external in-plane magnetic field. Simulations of pairs of magnetostatically coupled nanodisks were carried out for different interdisk distances and degrees of asymmetry. By analysing the results of the simulations, the effects of magnetostatic coupling and the asymmetry on resultant circulation of individual vortices were compared and the range of magnetostatic interaction between nanodisks of given dimensions and asymmetry was estimated. Experimental techniques used for fabrication and measurement of the samples are briefly summarized.

Magnetic vortices in ferromagnetic disks are curling magnetization structures characterized by the sense of the spin circulation in the plane of the disk and by the direction of the magnetization in the vortex core. Concepts of memory devices using the magnetic vortices as multibit memory cells have been presented, which brought the high demand for their research in many physical aspects. This work investigates the magnetostatic coupling in pairs of ferromagnetic disks to clarify the influence of nearby disks or other magnetic structures to the vortex nucleation mechanism. To ensure that the vortex nucleation is influenced only by the neighbouring magnetic structures, the randomness of the nucleation process was studied in single disks prior to the work on pairs of disks. We had to ensure that the vortex nucleation is influenced only by the neighbouring magnetic structures and not by an unwanted geometrical asymmetry in the studied disk. Lithographic capabilities were inspected in order to achieve the best possible geometry. Further we present a concept of electrical readout of the spin circulation using the anisotropic magnetoresistance, which allows automated measurements to provide sufficient statistics. To explain the magnetoresistance behaviour, numerical calculations together with magnetic force microscopy measurements are presented.

The diploma project Circulation tries to solve the problem of repeating cycles. It is an object with organic shape, created from a tube with light circulation on it. This object is based on idea of human constantly repeating actions and processes, whether they refer to the human body and mind, nature or society. The object is created site-specifically in to the gallery (Brno Gallery OFF/FORMAT) and tries to fill the space. The line passing through the gallery space can be seen as a route or path, but it can also remind a movement without a clear goal, or go around in circles. The omnipresent cycle, is then an individual contribution to the whole and it can be presented as a irregular curve full of dramatic twists and turns, ups and downs. The light (made by digital LED strip), which constantly copies the organic shape of the tube, represents an endless flow of information. The object tries to point out the never ending circulations in our lives; the object does not solve the problem, it is rather a statement.

Title: Modelling of global ocean circulation and ocean-induced magnetic field Author: Libor Šachl Department: Department of geophysics Supervisor: prof. RNDr. Zdeněk Martinec, DrSc., Department of geophysics Abstract: The ocean modelling community commonly use several renown ocean general circulation models (OGCMs) such as NEMO, MOM and FESOM. These models have been developed by research groups for many years, which resulted in complex mathematical and numerical algorithms. There are geophysically rele- vant problems, such as the glacial isostatic adjustment, in which the global ocean plays an important role. Ocean circulation does not need to be modeled extremely complex, but other phenomena such as time changing geometry of ocean domain needs to be considered. Geophysical applications motivated us to develop a new OGCM called LSOMG. The LSOMG model is not meant to substitute the ex- isting OGCMs but to provide a modelling framework for geophysical rather than purely oceanographic applications. LSOMG is a 3-D baroclinic ocean model fully parallelized using the MPI standard. It is forced by atmospheric fluxes (wind stresses, heat fluxes, etc.) but also by tides. The model can be run in a simplified 2-D barotropic version if 3-D effects can be neglected. LSOMG was tested in a series of simplified...