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Olfaction-mediated behavioural defence mechanisms in humans
Schwambergová, Dagmar ; Havlíček, Jan (advisor) ; Croy, Ilona (referee) ; Polák, Jakub (referee)
This thesis consists of two parts. The first part introduces the importance of behavioural defence mechanisms, specifically the behavioural immune system and mainly in humans. I review current knowledge regarding behavioural defence mediated by odour cues. Although behavioural defence mechanisms are important for all individuals who live in social groups, I focus on mate choice, because that is the context in which olfaction-mediated behavioural defence is studied the most. Subsequently, the importance of olfaction is demonstrated using the example of self-inspection and I discuss how the behavioural immune system may be intertwined with this relatively understudied behaviour. Finally, last chapter deals with associations between olfaction and other modalities that play a role in the detection of cues which help select a healthy and immunocompetent partner. In the second part of the thesis, I present nine papers: three reviews and six empirical studies. The review papers summarise the functioning of the behavioural immune system, olfaction- mediated pathogen avoidance in mammals, and the merely weak association between attractiveness ratings based on different modalities. The first empirical paper investigates whether the threat caused by the Covid-19 pandemic led to increased perceived disgust,...
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Association between human body odour and health status
Schwambergová, Dagmar ; Havlíček, Jan (advisor) ; Vinkler, Michal (referee)
The subject of this thesis is to evaluate a link between changes in body odor and health status in humans. The main aim was to create a theoretical overview of the available studies concerning humans, which are compared with studies conducted on mammals. Alteration of body odor due to the ongoing disease may negatively influence not only the odor attractiveness of a potential partner, but also may cause changes in behavioral response to a chemical stimulus for other members of the species. One may assume formation of perceptual adaptations exhibiting sensitivity to markers of health status in both sexes. Recognition of ill individuals may be crucial during social interactions, to prevent transmission of pathogens, but in mate choice the health status may also serve as an important indicator of resistance to infection, which can affect the viability of the offsprings. The main contribution of this thesis is to summarize the knowledge and insights into the area related to changes in body odor, depending on the health status. Keywords body odor, health, sexual selection, attractiveness, olfactory perception
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Analysis of a human body odour using comprehensive two-dimensional gas chromatography
Bušovská, Radka ; Sobotníková, Jana (advisor) ; Žáček, Petr (referee)
Body odour perception plays an important role in human mate choice, especially in women. It was previously proposed that women select partners whose body odour resembles that of woman's fathers. Yet, this phenomenon has only been confirmed using ethological studies based on subjective perception of body odour similarities. Therefore, the aim of my diploma thesis was to test this hypothesis instrumentally using comprehensive GC×GC-TOFMS and subsequent multidimensional analyses of body odour chemical profiles of male partners and fathers of adult women. Body odour sampling from left and right axilla of fathers and partners of 41 women (altogether 164 samples) was performed using cotton swabs, which were then frozen and extracted into hexane. Typical human volatile substances, such as hydrocarbons, carboxylic acids, esters, alcohols, aldehydes, ketones, sterols and terpenes were detected in all examined samples. Using a newly available "tile-based" chromatographic alignment algorithm, we obtained a set of 341 compounds systematically occurring in male axillary odour. The principal component analysis was used to calculate Euclidean distances for all pairs of the studied male subjects. These estimates of "chemical distances" revealed to be significantly smaller for father-partner pairs of individual...
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Mechanisms of human body odour production
Hrubová, Noemi ; Havlíček, Jan (advisor) ; Stopková, Romana (referee)
The sterile secret of skin glands is not immediately odoriferous. The characteristic body odour is released after microorganism transformation of the secreted compounds. The aim of the work is to elucidate the mechanisms of the body odour production. The major contributor to the body odour are volatile fatty acids hydrolysed from glutamine precursors, structurally unusual long- chain fatty acids or lipids. Another component are sulphur compounds, mainly secreted as the Cys-Gly-(S) conjugates, and steroid substances. The genus Corynebacterium is associated with these transformations and intense body odour. The composition of the resident microflora varies depending on age and gender. Axillary odour with large apocrine secretion has probably biggest importance for human chemical communication. Apocrine glands secretion starts during puberty and decreases in postmenopausal women. There are quantitative differences between gender composition of sweat. In the Asian population is more common the recessive homozygosity of the ABCC11 gene which is associated with lower body odour intensity. Also MHC proteins effect body odour and they seem to play a role in mate choice. To some extent, the environmental factors such as diet or emotions influence body odour. Knowledge of mechanisms behind body odour...
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Relationship between reactivity of immune system and quality of human body odour
Schwambergová, Dagmar ; Havlíček, Jan (advisor) ; Vinkler, Michal (referee)
It was previously proposed that expression of secondary sexual characteristics may provide cues to individual's immunocompetence. Body odour could partly serve as one of such characteristics, which provides crucial information about potentional partner even in humans. The main aim of the diploma thesis was to test a relationship between body odour quality and reactivity of immune system. In empirical part of the study we collected body odour samples from 21 men aged between 18-40 years before and two weeks after the vaccination against hepatitis A and B (Twinrix) and meningococcus (Menveo). The participant's blood samples were obtained three times to determine levels of IgG and IgM antibodies (markers of reactivity of immune system), testosterone, cortisol and CRP levels. In the second part of the study, a panel of 88 female raters aged 18-40 assessed body odour samples for their attractiveness, intensity and healthiness. In contrast to our expectations, we found no significant association between levels of antibodies induced by vaccination and perceived body odour attractiveness and health. Simultaneously, there were no significant changes in body odour ratings, neither in levels of testosterone and cortisol ratings, before and after the vaccination. However, we found a negative association...
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Association between human body odour and health status
Schwambergová, Dagmar ; Havlíček, Jan (advisor) ; Vinkler, Michal (referee)
The subject of this thesis is to evaluate a link between changes in body odor and health status in humans. The main aim was to create a theoretical overview of the available studies concerning humans, which are compared with studies conducted on mammals. Alteration of body odor due to the ongoing disease may negatively influence not only the odor attractiveness of a potential partner, but also may cause changes in behavioral response to a chemical stimulus for other members of the species. One may assume formation of perceptual adaptations exhibiting sensitivity to markers of health status in both sexes. Recognition of ill individuals may be crucial during social interactions, to prevent transmission of pathogens, but in mate choice the health status may also serve as an important indicator of resistance to infection, which can affect the viability of the offsprings. The main contribution of this thesis is to summarize the knowledge and insights into the area related to changes in body odor, depending on the health status. Keywords body odor, health, sexual selection, attractiveness, olfactory perception
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