National Repository of Grey Literature 52 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Tool for subjective quality evaluation of audiosignals restoration
Černý, Viktor ; Dorazil, Jan (referee) ; Záviška, Pavel (advisor)
Bacherol thesis deals with the theory of audio signal depreciation and reconstruction, with objective tests and subjective methods of reconstructed signal evaluation. At first, there are described several types of depreciation of audio signals and then reconstruction types for their reconstruction. After the reconstruction, types six objective and six subjective tests are mentioned for the evaluation of audio signal quality. The next part of the Bachelor thesis is the description of the program that was implemented in the programming language Java. The program is designed to design MOS, MUSHRA and ABX listening tests as well as to use for the actual testing. At the end of the thesis are the results of the listening tests that were used to test the program and the user ratings of the application.
Software for audio adjustment in multiple loudspeaker system
Černý, Viktor ; Schimmel, Jiří (referee) ; Sysel, Petr (advisor)
The first part of this Master’s Thesis deals with the theory of digital signal processing and describes the JUCE library. In this part some basic operations are explained with digital audio signals, such as polarity inversion, delay and linear interpolation of signal samples. The creation of new audio applications using the JUCE library in the C++ programming language is explained too. The next parts of this thesis describe the implemented audio application that allows the user to provide the described basic operations with digital audio signals in real time. For multiple channel audio signals the channels can be processed independently.
Influence of experimental intestinal dysbiosis on behavioral, neuroendocrine and immune properties of mice and the possibility of modifying it by administration of probiotic strain Escherichia coli O83:K24:H31
Avramová, Pavla ; Černý, Viktor (advisor) ; Roubalová, Radka (referee)
The gut microbiota is a key factor influencing the function of many organs in the human body, including the nervous, immune, and endocrine systems. This dynamic ecosystem can be modulated by diet, age, environment, even medication. The balanced composition of the microbiota is crucial for individual health, and its disruption leads to dysbiosis. The connection between the gut and the central nervous system is mediated by the microbiota-gut- brain axis. This axis consists of several pathways interconnected to mutually regulate their functions. Among the major components of the axis are the neural pathway, led by the vagus nerve, the immune pathway, and the endocrine pathway, including the HPA axis. Recent studies suggest that probiotic bacteria have the ability to partially rectify dysbiosis and alleviate its consequences for the organism. This thesis focuses on researching the impact of gastrointestinal tract microbiota on the behaviour, immunity, and neuroendocrine aspects of mice. It delves into experimentally inducing dysbiosis using antibiotics and subsequently addressing it with the probiotic bacterium Escherichia coli O83:K24:H31. The aim is to determine whether these probiotics can mitigate the adverse effects of dysbiosis on the immune and neuroendocrine systems, as well as behavioural...
Population Structure and History of the Sahel From the Point of View of Alcohol Metabolism
Jurišová, Lívia ; Černý, Viktor (advisor) ; Macholán, Miloš (referee)
The Sahel is the northernmost part of sub-Saharan Africa. The Sahel is inhabited by a complex mixture of people, who differ in their ethnic background, language affiliation and lifestyle. The most important and most studied gene of ethanol metabolism, ADH1B, has been understudied in the Sahel region, mainly due to the low frequency of the variant rs1229984-T, which accelerates the first step of alcohol metabolism. Due to its non- African origin, the variant rs1229984-T represents a suitable marker for population history study. The eastern Sahel is where immigrants from Arabia have been settling and mating with African populations since the 7th century CE. To study population structure and history from the point of view of alcohol meta- bolism, we have used already known genotype data from fourteen Sahelian populations, which inhabit mainly the eastern part of the region. Due to the absence of the critical locus rs1229984 in the genotyping array, the samples have been subjected to sequen- cing. Combined data from the microarray and the sequencing constituted 26 loci of the ADH1B gene and its close periphery, which came from 318 samples. Genotypic data needed to be converted into their haplotypic form by a phasing prog- ram. To choose the more appropriate phasing program, the data have been arranged...
Migrations in the African Sahel through the view of the genetic diversity of control segment of mitochondrial DNA
Adámková, Kristýna ; Černý, Viktor (advisor) ; Frynta, Daniel (referee)
Sub-Saharan Africa is the region with the highest diversity of anatomically modern humans (AMH). With the use of genetic analysis of mostly uniparental loci, gradually we can uncover the migratory activity of humans long time ago. This work focuses on the African Sahel. It is a long, horizontal strip bordered by the Sahara Desert and tropical rainforests across the entire continent. Favorable environmental conditions and the absence of a geographical barrier are suitable not only for mobile herders, but also for sedentary farmers. These provisos create high migration aktivity in the area. In this work, I newly sequenced 474 mitochondrial DNA samples of 11 populations. Populations of pastoralists and farmers are spread all over Sahel/Savannah belt. Intrapopulation analysis assessed diversity within the population and generally showed low values in pastoral populations, especially Fulani pastoralists in the western Sahel. Interpopulation analysis revealed bigger differences between individual populations than between populations clustered in the subsistence group of pastoralists or farmers, within regions or within language. The work included populations with Afro-Asiatic, Niger-Congo and Nilo-Saharan language families. Thanks to the Migrate-n program, in this work I was able to confirm the...
Evolution of PTC bitter taste receptors in West Africa
Holoubková, Tereza ; Černý, Viktor (advisor) ; Macholán, Miloš (referee)
The aim of this thesis is to determine whether the TASR38 gene is under selection pressure in West Africa and if its diversity varies within populations practicing different modes of subsistence. It further focuses on polymorphisms occurring in the gene and their association with sensitivity to the bitter tasting compound PTC. The thesis analyses 147 samples of saliva from three Mauritanian populations in order to sequence the DNA of the TAS2R38 gene exon. Ten polymorphic sites conditioning 16 haplotypes were observed in TAS2R38 gene. Mutations in amino acid positions 49, 262 and 296 occurred in all three populations; all eight possible haplotypes were observed. 94 % of them constitutes major PAV and AVI haplotypes and AAI haplotype, all of which were detected in each of the three populations. Additionally, 14 genotypes were identified in our sample; the most common being those created by a combination of the three haplotypes. Kruskal-Wallis test showed that TAS2R38 genotypes are strong predictors of PTC response in the examined African populations. PAV haplotype is associated with sensitivity to PTC (taster haplotype); conversely, AVI is a nontaster haplotype. At the same time, it was confirmed that PAV is an ancestral haplotype evolutionary closest to the chimpanzee TAS2R38 gene and it probably...
Y-chromosomal polymorphisms in the Czech population with focus on Moravian Valachs: evolutionary anthropology study.
Ehler, Edvard ; Vančata, Václav (advisor) ; Černý, Viktor (referee) ; Brdička, Radim (referee)
1 Abstract Aim: This study presents an evolutionary anthropology approach to the history of Moravian Valachs. The origins of Valach population are approached by evaluating the admixture event that marked the appearance of Moravian Valachs. Methods & data: Focus of my Ph.D. project lies on Y-chromosomal variation, using 12 Y-STR loci haplotype to compute population genetic statistics, to infer Y-chromosomal haplogroup information and to compare Moravian Valachs to other European populations. Admixture analysis was performed. Our data set contains haplotypic information from 44 populations with the total of 4757 individuals. Moravian Valachs are presented by 94 DNA samples. Results: Our data reveal a decreased genetic variability in Moravian Valachs compared to other Central European populations. This feature is most probably caused by isolation of Valach population. Multidimensional scaling and comparison of FST distances shows Valach population as related to populations from Poland, Romania and Macedonia. Shared haplotypes and AMOVA tests place the Valachs to the Central European region. Also admixture analysis, as well as demographic and historical data, stresses the influence of autochthonous population of Moravia in the forming of Moravian Valachs. Conclusion: Moravian Valachs represent a hybrid...
Co-evolutionary aspects of genetic diversity: milk production and lactase persistence
Priehodová, Edita ; Černý, Viktor (advisor) ; Brůžek, Jaroslav (referee) ; Macholán, Miloš (referee)
Lactase persistence (LP) is genetically determined ability to digest lactose (milk sugar) in adulthood. Lactose is digested by the intestinal enzyme - lactase. In mammals, production of lactase declines after the weaning period. In case of the LP, the lactase is produced during whole life and thus it is possible to drink larger amounts of fresh milk without digestive problems. However, LP is documented only in some human populations. Its worldwide distribution is unequal, the highest rates are found in northern Europe and in pastoralists living in arid regions of Africa and Arabia. The origin of this trait is related to the emergence of agriculture 10,000 years ago, and the beginnings of milk production. In some populations, there is a strong signal of positive selection for the LP caused by various factors depending on various living conditions. The LP is associated with single nucleotide polymorphisms (SNPs) located approximately 14 kb upstream from lactase gene. Nowadays we know five different SNPs which cause the LP and they have probably different origin and have expanded independently. One of the possible centres of the LP origin is the Arabian Peninsula, where the LP variant -13,915*G probably first appeared and spread. In this thesis, occurrences of different LP mutations were investigated...
Biological characteristics of individuals from the baroque level of St. Benedict cemetery in Prague - an analysis of the demographical crisis
Pinkr, Tomáš ; Brůžek, Jaroslav (advisor) ; Černý, Viktor (referee)
The target of this thesis was to identify mass graves of the burial phase V. in the cemetery around the former St. Benedict Church in Prague and to determine, by means of dental epigenetic traits, if there is a biological relation among selected groups of mass graves and if they belong to one demographic crisis. The analysis of the archaeology-anthropologic documentation was the essential part of this thesis. By this analysis the identification of mass graves and their combination to higher groups according to the following criteria: a locating the mass grave at the cemetery, a position of individual burials in the mass graves, the burial way and artefacts found was possible. The previous research made by the French- Czech team, namely radiocarbon dating of several graves, was also supportive. The actual investigation of the biological relation (similarity) of individuals from mass graves was carried out by means of dental epigenetic traits. These traits were evaluated according to verbal description and plaster casts of teeth (Turner at al. 1991). The following statistical methods were used for the evaluation: a measure of divergence and the mean measure of divergence stating the unlikeness of probability occurrence of corresponding features. The result of this work was the identification of 19 mass graves...

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