|
|
Influence of latent toxoplasmosis on intelligence of infected subjects
Chvátalová, Veronika ; Flegr, Jaroslav (advisor) ; Lindová, Jitka (referee)
There remain inconsistencies in the literature concerning the intelligence of subjects infected with latent toxoplasmosis. The main goals of this work are to find out whether, a) latent toxoplasmosis influences the intelligence of infected subjects and b) whether Rh negative and Rh positive subjects respond to the infection in different ways. In this work we used a complex test of intelligence, The Structure Intelligence Test I-S-T 2000 R. We were able to statistically control for the confounding variable the size of the place of residence in childhood. This had benefits when compared to previous studies. The differences in intelligence were measured in students of The Faculty of Science. The sample used included 46 toxoplasma-infected and 188 toxoplasma-free individuals. Using nonparametric tests we found lower numerical, fluid and general intelligence in toxoplasma-infected subjects compared to noninfected subjects. In addition, these tendencies were also observed in the results of parametric tests. Further to these components of intelligence there was also found to be a lower component of numerical knowledge in toxoplasma-infected males. By contrast, no differences between infected and noninfected individuals was found to occur in the female test subjects. No statistically significant...
|
|
| |
|
| |
|
|
The architecture of regulatory network of metabolism
Geryk, Jan ; Flegr, Jaroslav (advisor) ; Cvrčková, Fatima (referee) ; Šafránek, David (referee)
The thesis focus on the modularity of metabolic network and foremost on the architecture of regulatory network representing direct regulatory interactions between metabolites and enzymes. I focus on the "modularity measure" in my first work. Modularity measure is quantitative measure of network modularity commonly used for module identification. It was showed that algorithms using this measure can produce modules that are composed of two clearly pronounced sub-modules. Maximum size of module for which there is a risk that is is composed of two sub-modules is called resolution limit of modularity measure. In my first work I generalize resolution limit of modularity measure. The generalized version provide insight to the origin of resolution limit in the null-model used by modularity measure. Moreover it is showed that the risk of omitting of sub-modular structures applies for bigger modules than mentioned in the original publication. The second work is focused on the question how does the modular structure of E. coli metabolic network change if we add regulatory interactions. I find that the modularity of modular core of network slightly increase after regulatory edges addition. The modularity increase is significant with respect to randomized ensemble of regulatory networks. Identified modules...
|
|
|
Macroevolutionary and ecological implications of the theory of frozen plasticity
Toman, Jan ; Flegr, Jaroslav (advisor) ; Fatka, Oldřich (referee) ; Mikuláš, Radek (referee)
The frozen plasticity theory is a punctuationalist theory of adaptive evolution. It states that long periods of stasis, during which populations respond to selection pressures only by elastic change in the frequency of already present alleles, alternate in the evolution of sexual species with short periods of plastic evolution, during which alleles can get fixed or eliminated by directed selection. Asexual species are not expected to maintain such high genetic polymorphism in the long term. They should, however, be able to plastically respond to selection pressures throughout their whole existence. This difference between the evolutionary dynamics of sexual and asexual clades has a number of ecological and macroevolutionary implications. Concerning ecology, we could expect different environmental preferences of sexual and asexual species. Accordingly, in our first work that was based on a comparative study, we statistically significantly supported the hypothesis that (ancient) asexual groups of (eukaryotes) inhabit more stable and homogeneous habitats than their related sexual controls. Focusing on actually experienced, i.e. subjective, heterogeneity of the environment turned out to be the crucial factor of this type of research. From the viewpoint of macroevolutionary implications of the frozen...
|
|
|
Gender differences in behavioral changes induced by latent toxoplasmosis
Lindová, Jitka ; Flegr, Jaroslav (advisor) ; Špinka, Marek (referee) ; Ditrich, Oleg (referee)
Summaryof resultsofpresentedresearch Toxoplasmagondiiis a protozoanparasiteinfectingabout30%ofour population.After a shortphaseof acuteinfection,the parasitosistums into the lifelong latents.tagewhich is usuallyconsideredasymptomatic.However,in thestudiesperformedby our researchteam, latenttoxoplasmosiswasťoundto havespecificeffectson personality,behavior,morphology andphysiotogy.Interestingly'in manyaspects,theseeffectswereclearlygender-dífferent. My thesis was motivatedby results of previous questionnairestudies which found toxoplasmosisto haveoppositeinfluenceon men's and women'spersonalitytraitswarmth, conscíentiousnessandvigilancemeasuredby Cattell's16PersonalityFactorQuestionnaire (Flegretď. L996,1999,2000'FlegrandHavlíček1999'FlegrandHrdý 1994).Bothinfected womenand men werealso foundto score lower in novelryseeking(Skallová et al. 2005' Flegretal.2003). The resultof lowernoveltyseekingwas confirmedby thefirst studyperformedwith my contribution(lt{ovotnáet al. 2005).Moreover,this studyshowedthat regardingnovelty seeking,similar changeswere observedin subjectsinťectedby cytomega|ovirus.This was interprétedasevidenceforthehypothesisthatbehavioral/personalityshifu inducedby latent toxoplasmosiscouldbenonspecificchanges,causedby mildchronicbraininfections.Lower novelty seeking is thought to be associated...
|
|
|
The relation between morphological and personality traits in humans
Sýkorová, Kateřina ; Flegr, Jaroslav (advisor) ; Třebický, Vít (referee)
In humans, as in animals, associations or correlations between morphological and personality traits can be observed. Some of the most conspicuous and well describable morphological traits in humans are eye color, hair color, body height and body mass index (BMI). These traits can correlate not only with temperament or character, but also, for example, with intelligence. Relations between morphology and personality can have an origin on a genetic or an environmental level. The human psyche, which can be influenced by social factors, can also have a role in the chain of causes and consequences. In this study, known relations between morphological traits and personality are discussed and mechanisms which could be responsible for these relations are mentioned. This study also focuses on the possible role of the environment which could explain some associations between the traits. Further, there is an attempt to identify environmental factors contributing to the morphological and personality traits which could therefore be a cause of some correlation between these traits.
|
|
|
Associations between red colour of hair and other morphological, physiological, and behavioral traits
Musil, Martin ; Flegr, Jaroslav (advisor) ; Fiala, Vojtěch (referee)
Hair and skin colour are one of the most visible external features that can be encountered in humans. Red hair colour is the least common colour. It is associated with fair skin, which is prone to ultraviolet radiation. This is captured by eumelanin, which is less common in redheads because they have more pheomelanin pigment. Because of this, red-haired people are in a higher risk of developing malignant melanoma. This risk is further increased by more freckles and nevi on the skin. The major gene behind red hair is MC1R. This gene forms a receptor that binds hormones that regulate pigment production. Red-haired people have a gene allele that is demonstrated by partial or complete loss of MC1R receptor function. According to some studies, red hair also affects how red-haired people feel pain and whether they need more anaesthetics to induce general anaesthesia. The practical part of this work consists of a survey which topics are covered in published studies that mention red hairs in their title or abstract. The survey was conducted on three search engine Web of science, Google scholar and PubMed. All databases contained the most articles that linked red hairs as a risk for malignant melanoma. Key words: redhair, phenotype, human, eumelanin, pheomelanin, pigmentation, melanoma
|
|
|
Phenomenon of watching cat videos and photos on the Internet from the point of view meme theory
Bessisso, Omar ; Flegr, Jaroslav (advisor) ; Kopecký, Robin (referee)
Main theme of this bachelor's thesis is phenomenon of watching videos and photos with cats on the internet in the light of memetics, psychology and evolutionary psychology. Further discussion is focused on impacts of living with a cat and possibility of cats as social parasites. This thesis was created on the basis of current reasearch papers and data provided by various search engines. Pictures and videos of cats are one of the most viewed contents on the internet. Funny cat video can be captured by almost everyone. Procrastination is one of the concerns caused by aforementioned phenomenon. It shows that quick view of funny video may result in increased working morale and elevation of good mood. Cat videos are successful by the virtue of combining qualities of cuteness and humor. Intnernet memes featuring cats are successful as well, cats may be considered as the favorite animal of the internet, which is related to the fact, that cats are popular among introverted people. Introverted people spend more time on the internet. Cuteness of cats is possible (pre)adaptation for life in human society. Cats and kittens trigger cute response in same way toddlers do which may hinder parental instincts. The way cats look and act makes us crave to take care of them. Cats are likely social parasites. Cat...
|
|
|
Neural Correlates of Consciousness: Theoretical problems and Candidates
Blaštík, Filip ; Flegr, Jaroslav (advisor) ; Boschetti, Silvia (referee)
Consciousness is part of the world, which yet resisted a scientific inquiries for an ages. This work is mainly concerned around Neural Correlates of Consciousness program which should uncover a nature of the consciousness. It covers wide variety of a theoretical problems, the first part is concerned around the ambivalence of Neural Correlates of Consciousness definition and its alternatives. The second part asks a questions, whether the neural correlates of consciousness is only discourse creating entity and sheds a light on the dilemma, if the right correlations to form neural correlates of consciousness are possible. It is done on a basis of the experimental evidence and their attempts to form Neural Correlate of Consciousness. In third chapter the philosophical dilemma is exposed. The dilemma arises from conceptual decisions "What is to be conscious", how researchers philosophically pre-conceptualize the scientific question. This is tried to be reconciled by unification of the philosophical theories. Alas it is shown the unification of the theories of mind is impossible. From this is drawn a conclusion that the philosophical pre-conception is a necessary ingredient to form the neural correlate of consciousness. To breach from mere a correlation to a causality is a matter of choosing testable and...
|
guest ::
RSS feed.