|
Arctic tundra dendrochronology
Lehejček, Jiří ; Svoboda, Miroslav (advisor) ; Monika, Monika (referee)
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.
|
|
Information content in vocalization of guinea pigs (Cavia porcellus): individual distinction and recognition of predators
Baklová, Aneta ; Baranyiová, Eva (advisor) ; František, František (referee)
Guinea pigs represent domesticated precocious rodents which became common pets. From the first day after birth they are fully vocal. This thesis was devoted
to the vocalization of pups. The aim of the thesis was to 1) determine the age when the vocal individuality in whistle sound is demonstrable; 2) test possible ultrasonic signals emitted by young guinea pigs; 3) study the antipredator reactions and alarm calls to aerial (bird of prey) and terrestrial (dog) predators and human (control test).
A total of 16 guinea pig pups were tested for vocal individuality, 28 pups
for ultrasonic vocalization and 27 adolescents for predator recognition. When testing vocal ontogeny during the first 9 days after birth, I observed changes in temporal, frequency and parameter of intensity . When I test vocal individuality by cross-validated discriminant function analysis (DFA) based on ten acoustic parameters, calls were classified to correct animals with following success: day 1 = 71.9%, day 3 = 58.8%, day 5 = 53.10%, day 7 = 50.60% and day 9 = 63.10%. The highest frequency in whistle was 30.03 kHz. In predator discrimination reactions as freezing, fleeing and vigilance were observed. In the presence of dog, guinea pigs reacted for the longest time and most frequently by freezing. When confronted with a bird of prey, I observed for a longest time and most often fleeing and then freezing. When exposed to a human, guinea pigs showed mostly vigilance. Almost no vocalization was observed except for two events
of alarm calls - drrr as in the presence of dog and chirrup as reaction to bird of prey.
The following conclusions can be drawn from the presented results: 1) vocal individuality of guinea pigs is demonstrable immediately after birth and the rate
of individually different vocal parameters changes with age; 2) guinea pigs are able
to produce sound up to 30 kHz, i.e. within the ultrasound range, but signals of high frequencies are not crucial for their communication; 3) guinea pigs discriminate between terrestrial and aerial predators, but they emit alarm calls rather rarely.
|
|
Influence of meadow management on the migration behavior of selected species of butterflies
Bubová, Terezie ; Langrová, Iva (advisor) ; Farkač, Jan (referee)
Migrations are the key process and one of the basic biological features, which allow survival of endangered species in fragmented landscape. In the last decades, agriculture intensification, industry and urbanization caused that number of natural butterfly habitats has significantly decreased. The localities originally suitable for butterflies are currnetly converted to farmland or building plots. This PhD thesis aimed to find a compromise solution of meadow management, which should allow a commercial use and concurrently do not jeopardize the continued existence of endangered or threatened species. The main idea of this study was in the intentional emigration causing in the middle of flight period, which should lead into resettlement of the population to another (potentially more suitable) locality. Possibility of aimed manipulation with butterfly emigrations would be considered as a major breakthrough in their protection.
The investigated species Phengaris nausithous (Bergsträsser, 1779) and Phengaris teleius (Bergsträsser, 1779) are both considered to be flagship species for protection of European butterflies at open meadows. This study is based on research, which was carried out in 2013-2015 at 17 patch in localities Dolní Labe, Czech Republic. In above mentioned years, one selected meadow was mowed in the middle of flight season and the emigrations were then monitored using mark-release-recapture method. Results of population and migration characteristics were calculated in MARK 8.1 software. Subsequently, the effect of mowing on emigration (comparison of emigrations from the meadow before and after mowing) was evaluated using Statistica 13.
The hypotheses of this study were based on the assumption, that the loss of resources after well-timed mowing should increase the activity of adult butterflies. During the monitoring, number of emigrations was increased only in flight season 2015. Unfortunately, the statistical evaluation did not show significant effect of mowing on migrations. On the other hand, the hypothesis dealing with colonization of nearest meadows was confirmed.
Effect of intentional emigration caused by management interventions was unfortunately not proved. However, we found out, that even though the population at one mowed meadow decreased clearly, the metapopulation size at the locality remained more or less stable.
At investigated (mowed) meadow, there was observed a sharp decline of P. nausithous abundance. On the other hand, P. teleius population was only slightly reduced. It is therefore conceivable, that P. teleius are not as susceptible to innapropriate term of mowing. The results obtained in our research conclusively displayed no possible positive effect of mowing in the middle of flight season and a necessity of suitable management maintenance at localities inhabited by Phengaris butterflies.
|
|
Playing as a means of increasing motivation in teaching vocational subjects
Kolmanová, Linda ; Hanušová, Marie (advisor) ; Drahomíra, Drahomíra (referee)
Bachelor thesis called A play as a means of improving motivation in teaching vocational subjects, is used for the needs of their insight into the problems of motivation in school and its improvement through the activation methods specifically games. The theoretical part brings basic concepts that relate to the themes of the motivation in school and activation methods in education, which are the basis for the development of the practical part. In the practical part is through the observation and the final test in the learning block validated the proposed board game of economic, as the activation method for increasing the motivation of the economic sector. Last but not least, the results are presented and carried out.
|
|
I/O Aerosol in Kindergarten - Case Study.
Ondráček, Jakub ; Talbot, Nicholas ; Cusack, Michael ; Vodička, Petr ; Ždímal, Vladimír ; Schwarz, Jaroslav
In last decades, people spend more and more time indoors. When various indoor sources are present, the indoor air quality is driven mainly by these sources. Without the presence of significant indoor sources, the situation is very different and the concentration of aerosol particles in indoor environment follows behavior of outdoor particles (taking into account losses of aerosol particles due to deposition on indoor surfaces and during penetration indoors. Many epidemiological studies show direct link between dose/exposition to fine (< 1µm) and ultrafine (< 100 nm) particles and adverse health effects. With regards to the fact that indoor environment is besides the adults occupied usually also by kids in longer time periods, it is very important to study the indoor environment in a great detail and to understand the behavior of aerosol particles indoors. In the case of the kids being exposed to the indoor aerosol particles, the adverse health effect can be more pronounced and the consequences more dangerous. Nevertheles, at the same time it is necessary to monitor the outdoor environment as well by observing its changing daily pattern and trying to identify the possible sources of outdoor air pollution.\n
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22016102412233 - PDF
|
|
Possibilities in monitoring of laser welding process
Horník, Petr ; Mrňa, Libor
With increasing demands on the quality of the welds, it is usual to apply automated machine welding with monitoring of the welding process. The resulting quality of the weld is largely affected by the behavior of keyhole. However, its direct observation during the welding process is practically impossible and it is necessary to use indirect methods. At ISI we develop optical methods of monitoring the process based on analysis of radiation of laser-induced plasma using Fourier and autocorrelation analysis. Observation of keyhole inlet opening is partially possible through a coaxial camera mounted on the welding head and the subsequent image processing. A high-speed rear camera to understand the dynamics of the plasma plume. Through optical spectroscopy of the plume, we can study the excitation of elements in a material. Shielding gas flow can be visualized using schlieren method.
|
|
Navigation of mobile robots
Rozman, Jaroslav ; Matoušek,, Václav (referee) ; Šolc, František (referee) ; Zbořil, František (advisor)
Mobile robotics has been very discussed and wide spread topic recently. This due to the development in the computer technology that allows us to create better and more sophisticated robots. The goal of this effort is to create robots that will be able to autonomously move in the chosen environment. To achieve this goal, it is necessary for the robot to create the map of its environment, where the motion planning will occur. Nowadays, the probabilistic algorithms based on the SLAM algorithm are considered standard in the mapping in these times. This Phd. thesis deals with the proposal of the motion planning of the robot with stereocamera placed on the pan-and-tilt unit. The motion planning is designed with regard to the use of algorithms, which will look for the significant features in the pair of the images. With the use of the triangulation the map, or a model will be created. The benefits of this work can be divided into three parts. In the first one the way of marking the free area, where the robot will plan its motion, is described. The second part describes the motion planning of the robot in this free area. It takes into account the properties of the SLAM algorithm and it tries to plan the exploration in order to create the most precise map. The motion of the pan-and-tilt unit is described in the third part. It takes advantage of the fact that the robot can observe places that are in the different directions than the robot moves. This allows us to observe much bigger space without losing the information about the precision of the movements.
|
|
Multimedia Data Processing in Heterogeneous Distributed Environment
Kajan, Rudolf ; Ferko,, Andrej (referee) ; Míkovec, Zdeněk (referee) ; Herout, Adam (advisor)
Pervasive computing sa zameriava odstránenie zložitostí pri interakcii s výpočtovou technikou a zvýšenie efektivity pri jej každodennom používaní. Ale i po viac ako 15 rokoch od sformulovania hlavných cieľov Pervasive computingu existujú aspekty interakcie ktoré stále nie sú súčasťou užívateľskej skúsenosti s dnešnou technológiou. Bezproblémová integrácia s prostredím vedúca k technologickej neviditeľnosti, alebo interakcia naprieč rôznymi zariadeniami predstavujú stále veľkú výzvu. Hlavným cieľom tejto práce je prispieť k tomu, aby sa ciele Pervasive computingu priblížili k realizovaniu tým, že predstavíme spôsob intuitívneho zdieľania informácií medzi osobným a verejne umiestneným zariadením. Predstavili sme tri interakčné techniky, ktoré podporujú intuitívnu výmenu obsahu medzi osobným zariadením a zdieľaným displejom. Tieto techniky sú založené na prenose videa, rozšírenej realite a analýze pohľadových dát. Okrem interakčných techník sme tiež predstavili mechanizmus pre získavanie, prenos a rekonštrukciu aplikačného stavu na cieľovom zariadení.
|
|
(Arbo)viruses in high European Arctic
ELSTEROVÁ, Jana
Since an ongoing climate change covers strongly the polar areas. Higher temperatures and related climate parameters bring the emergence of new parasites and their pathogens to higher latitudes. This may influence zoonotic diseases including arthropod-transmitted diseases. The tick species Ixodes uriae, parasitizing seabirds in the Arctic, may transmit many pathogens including various arboviruses, Borrelia spirochetes and Babesia apicomplexans. In the study we diagnosed 89 individuals of seabird tick Ixodes uriae and searched for arthropod-borne viruses from the genera Flavivirus, Alphavirus, Orthobunyavirus, Phlebovirus and Orbivirus using genus-specific primers. Moreover we searched for presence of Borrelia spp. and Babesia spp. DNA in the ticks. All samples were negative after PCR amplification for all tested pathogens. The result signalizes that tested pathogens might not be present in such high latitudes of European Arctic. Though, the possibility of introduction of these pathogens may be observable in near future due to quick changing of the Arctic ecosystem with the rising of migration of vertebrate hosts including humans to the polar areas. It is though important to continue to study potential presence of pathogens in polar areas. We are working on increase of the number of tick samples to confirm the presence or absence of the tick-borne pathogens in the European Arctic.
|
|
Characteristics of the working behavior of Czechs and Ukrainians
BYKOVA, Sofia
The aim of this work is to create a transparent and comparable characteristics of the work behavior phenomenon within the cultures of those states - what is common and what is different between them, or maybe incompatible .It is supposed to have some analysis of possible conflicts and their connection with the mentality. The primary reason of this aim choosing is the specialty I study. My work contains information that could be interesting and useful not only for me and my future job, but also for managers and other employees. Overview of examined issues contains specific points, such as the fundamentals of economic psychology and behavioral economics (symbiosis of psychological and economic opinion on motivation and rationality of individuals), theories of motivation and reaction to different occurrence, characteristic of the term "mentality", general points about the human impact of the world economy. For realizing the goals of my work the following hypotheses have been proposed - Czech and Ukrainian mentality have significant differences, though these cultures are close. - Ukrainian and Czech employees are able to work effectively in a team and find a "common language" in the workplace. The difference in mentality does not obstruct on it. - Employers could be interested in the Ukrainian employees taking into account their high concernment and motivation. All three of the hypotheses were confirmed by observed data and comparison of mentality characteristics. Czechs are often tolerant to other cultures, moreover Ukrainian culture is not much different and does not create difficulties in the working relationship. Based on the fact that the chosen company has no conflicts associated with work behavior and differences in mentality, it's hard to define my contribution to this organization work.
|
guest ::
