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Magnetic orientation in mammals
Tejmlová, Kristýna ; Němec, Pavel (advisor) ; Vácha, Martin (referee)
Earth's magnetic field can provide animal with both directional and positional information. The ability to perceive and utilize information extracted from the geomagnetic field is called magnetoreception. Magnetoreception mechanisms remain largely unknown. Three main hypotheses are currently supported by experimental evidence. The light-independent mechanisms are based either on electromagnetic induction or on biogenic magnetite. The light-dependent mechanism is based on specific chemical reaction between radical pairs. Perception of the geomagnetic field facilitates both long- and short-distance orientation of animals. Some animals exhibit the magnetic alignment, i.e., spontaneuos preference for a certain geomagnetic direction. Another manifestation of magnetoreception is magnetic compass (polarity- or inclination-based, depending on species), which enable an animal to determine the azimuth, i.e., the angle between the direction of motion and geomagnetic field vector. Magnetic map sense enable an animal to determine its position and direction to the goal destination, most likely utilizing the inclination and the intensity of the geomagnetic field as navigational cues. Magnetic orientation of mammals seems to be a widespread phenomenon. Light- independend, polarity compass has been reported in...
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Sensitivity to magnetic field in Mexican Cavefish
JANDA, Patrik
This thesis deals with the detection of magnetic field perception of cavefishes the Mexican tetra (Astyanax mexicanus). The experiments were carried out in a plus-shaped maze where the direction preference in the individual arms of this maze was studied both in the natural Earth´s magnetic field and in the modified one by using magnets and turning the north-south axis by 90°. The reactions of the specimen on placing a strong magnet close behind the end of the western and later also the eastern arm of the plus-shaped maze were also monitored. It was conclusively found that the Mexican tetra prefer north-south axis. However, after turning the magnetic field by 90° there was no preference of the specimen for the new north-south axis as we expected. Although some of the tests performed here show the perceptiveness of magnetic field of the Mexican tetra and their preference for the noth-south axis, other tests disprove the formulated hypothesis. That is why other new hypotheses about the perceptiveness of the magnetic field should be created so that they could not be disproved in either case. This thesis has served as a stepping stone for further research in the field of magnetoreception of cavefishes.
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Neural Basis of magnetic compass orientation in C57BL/6J mice
Bláhová, Veronika ; Němec, Pavel (advisor) ; Druga, Rastislav (referee)
The ability to perceive the Earth's magnetic field has been demonstrated in a variety of animals, including representatives of all five classes of vertebrates. The physiological mechanisms underlying magnetic field sensation, however, remain largely unknown. Behavioral, physiological, neuroethological studies and studies using early response genes as neuronal activation markers indicated that a major role in the perception and processing of magnetic information play trigeminal, vestibular and visual systems. Subsequently, magnetic information seem to be integrated with multimodal sensory and motor information within the hippocampal-entorhinal system. In the majority of studies, however, birds have been used as model organisms. In this work I analyzed the neural substrate of magnetic compass orientation in the mouse strain C57BL/6J using markers c-Fos and Egr1. I found that all the aforementioned systems contain neurons responsive to the experimental magnetic fields. This finding demonstrates a complex processing of the magnetic information at level of the central nervous system.
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Ověření magnetické orientace u savců
KOČANDRLOVÁ, Barbora
Thesis is monitoring body orientation during the day cycle, with a special focus on the body orientation during resting and grazing cattle. Environmental conditions including the Earth's magnetic field which affect the animal orientation have been evaluated. Body orientation of the selected individuals was determined by compass, directly every half hour at the site. In total 24 cows in 2 herds were monitored. In every herd were chosen 12 easily recognizable individuals. Monitoring took place 7 days in September 2016. About weather conditions (wind, rain, sun, temperature) and resting of the individuals was kept an account, which would affect the cattle orientation. This study could not confirm the theory of the N-S cattle orientation by magnetic field and therefore can not confirm or disprove the influence of the power line to the cattle orientation. Even at rest or grazing cattle the theory of the N-S orientation could not be confirmed.
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Stanovení pozičního chování savců se zaměřením na magnetické pole Země
FOLEJTAROVÁ, Lucie
Currently, much attention is paid to magnetoreception, a sense which allows an organism to detect a magnetic field of the earth. Now, this discovery is related to positional behaviour of animals (magnetic alignment) in the magnetic field and the world phenomenon of "magnetic cows". The magnetic alignment is a spontaneous (congenital) behaviour, when the animal puts its body axis into the positions of north - south or east - west. Most studies have demonstrated the north - south direction preference. This work contributes to clarify positional behaviour of cattle during the daily cycle. This study is based on a different data collection and is targeted at individuals in the herd. Individuals were photographed in a given direction, at hourly intervals. The magnetic alignment was determined in 26 individuals from three different cattle herds, mainly east or west. Statistically significant results during daily cycles in individual intervals also confirmed the north - south direction preference. There were also discussed the environmental conditions that may affect the final result. For inconclusive results, the individuals were probably motivated by temporarily more important local incentives.
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Magnetic orientation in mammals
Tejmlová, Kristýna ; Němec, Pavel (advisor) ; Vácha, Martin (referee)
Earth's magnetic field can provide animal with both directional and positional information. The ability to perceive and utilize information extracted from the geomagnetic field is called magnetoreception. Magnetoreception mechanisms remain largely unknown. Three main hypotheses are currently supported by experimental evidence. The light-independent mechanisms are based either on electromagnetic induction or on biogenic magnetite. The light-dependent mechanism is based on specific chemical reaction between radical pairs. Perception of the geomagnetic field facilitates both long- and short-distance orientation of animals. Some animals exhibit the magnetic alignment, i.e., spontaneuos preference for a certain geomagnetic direction. Another manifestation of magnetoreception is magnetic compass (polarity- or inclination-based, depending on species), which enable an animal to determine the azimuth, i.e., the angle between the direction of motion and geomagnetic field vector. Magnetic map sense enable an animal to determine its position and direction to the goal destination, most likely utilizing the inclination and the intensity of the geomagnetic field as navigational cues. Magnetic orientation of mammals seems to be a widespread phenomenon. Light- independend, polarity compass has been reported in...
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Escape behavior of roe deer
Waignerová, Pavla ; Obleser, Petr (advisor) ; Adámková, Jana (referee)
The work deals with the way of life of our most common game, especially roe deer and escape behaviour and strategies of escape. The observation was focused on the perception of the Earth's magnetic field roe deer. Which in this work due to lack of data did not. Other observations dealt with the response to an incoming man in connection with the perception of colour and intensity of light. Breakout and the reaction distance proved to be dependent on the colour of clothing and on the intensity of the illumination, the reaction and the escape came earlier, when an observer was dressed in a red dress, than when he was in the green. And at a higher intensity of daylight responded beasts before when light intensity was lower. The results of the experimental part of the work did not confirm the hypothesis of similar scientific works dealing with the magnetoreception and the visual perception of the roe deer.
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Evaluation of impact of magnetoreception at farmed fallow deers.
Wedlichová, Romana ; Hart, Vlastimil (advisor) ; Pleskač, Lukáš (referee)
Bachelor thesis deals mapping of the Earth's magnetic field with fallow deer on the farm. The theoretical part of the thesis describes the magnetic field principles magnetoreception and magnetic orientation of animals. Magnetoreception is the ability to perceive the Earth's magnetic field animals to take directional and positional information and use it to navigate in space. The practical part is the evaluation of field monitoring game. During direct observations were grazing or resting game photographed and was written the direction which the photo was taken. This was followed by the evaluation of the direction of orientation of game on the farm. There was also a comparison of the data according to the current state of the weather and according to the distribution of males, females and cubs. When evaluating the results was confirmed by hypothesis, that vertebrates, in this case, fallow deer are in everyday processes alignment the north-south axis.
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The influence of the Earth magnetic field on communication strategy of roebucks and fishes
Brus, Radek ; Hart, Vlastimil (advisor) ; Mrkvičková Kořanová, Diana (referee)
This thesis focuses on the communication strategies of roe deer and fish. Roe deers live from April to September territorial way, they live the remaining part of the year in common groups. To territory marking roe deers using chemical and optical biocommunication- breaking antlers and raking. This work is also focused on our most common fish carp. From Czech fish only carps intensive jumps out of the water, which could be one of the modes of communication. The carp is shoal fish, it lives social way of life. Carp is the most active in summer, in the summer is also the most jumps. After the data showed that carps and roe deers are oriented in the north-south axis, with a preference of north. The resulting vector in the direct observation of raking roe deers 7,5 ° and jumping carps out of the water 341.5 ° confirm magnetoreception in both species.
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Effect of changes in the magnetic field on the behavior of common carp
Švrčula, Daniel ; Hart, Vlastimil (advisor) ; Svoboda, Jan (referee)
The main topic is the effect of changes in Earth's magnetic field on the behavior of common carp, with a focus on fish farming, as part of associated forest production. The ability of animals to perceive the magnetic field has been demonstrated countless times, but it is still not clear how animals perceive and process information that it provides the geomagnetic field. The theoretical part focuses on magnetorecepcia describes the various mechanisms and discovered knowledge. It also focuses on examples of the use of magnetoreception for the direct benefit of vertebrates. Characteristics of common carp and pond management, and examples of the management of common carp. The practical part is focused on the evaluation of the influence of Earth's magnetic field on common carp. Main attention is given to the positional behavior, as one of the manifestations of magnetoreception. For the evaluation of the data was used statistical software Oriana 4.0., which works on the principle of pie charts. The results support the theory of positional animal behavior and the influence of magnetic field on their behavior. The result is, that carps align their bodies in a north-south axis, but if a situation arises where there is unrest in the Earth's magnetic field, known as a magnetic storm, when is magnetic storm there are changes in the positional behavior. Carp did not show any directional preference. This result proves that carps respond to the changes of Earth's magnetic field.
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