A presente pesquisa tem como objetivo “seguir” a da substância testosterona e as maneiras pelas quais ela é performada como/em diversas realidades. A partir da perspectiva da Teoria Ator-Rede de Bruno Latour, toma-se o hormônio testosterona como um ator não-humano, o qual integra uma rede que articula diferentes campos como médico/jurídico/mercadológico. Para tanto, foram realizadas entrevistas etnográficas com um médico endocrinologista, dois personal trainer e participantes de academia, dois homens trans que fazem acompanhamento com um profissional da medicina, bem como foram analisados sites, fóruns, vídeos, bulas de medicamentos e artigos científicos. No decorrer da investigação, identificamos duas principais redes nas quais a testosterona é materializada, que estão em constante disputa/coordenação, as quais nomeei de “ciclos”, em referência aos ciclos de testosterona demonstrados por alguns interlocutores deste trabalho. Tais redes são: 1) Ciclo Fármaco-Biomédico, no qual destaca-se o acesso à substância mediado pelo discurso médico e; 2) Ciclo Fármaco-Bombado, no qual a testosterona circula através de outras formas de acesso, que burlam a mediação médico-paciente e/ou prescrição médica, como aquelas que ocorrem em academias de ginástica e nas vendas/trocas de hormônios realizadas por grupos de atletas e/ou grupos de homens trans. O principal objetivo do trabalho foi demonstrar as diversas maneiras pelas quais a testosterona é performada nessas múltiplas realidades, à luz da teoria praxiográfica neo-materialista de Anemarrie Mol, a partir das descrições da rede, e seus respectivos atores e articulações. Dessa forma, demonstra-se a dissolução do binarismo natureza-cultura pensando na utilização da testosterona para a materialização de corpos de sujeitos inscritos nas masculinidades. E mais que isso, expõe que a testosterona, ao multiplicar-se em práticas que envolvem tanto homens cis quanto trans, a partir do acesso dificultado por todos esses sujeitos à substância, dissolve as fronteiras imaginadas entre tais corpos, na medida em que todo o controle acerca da testosterona pelo domínio biomédico, impulsionado pela necessidade de imitar a fisiologia, demonstra um caráter moral que está diretamente ligado à utilização dessa substância. / The present research aims to "follow" the testosterone substance and the ways in which it is performed as / in various realities. From the perspective of Bruno Latour's Theory-Actor Network, the testosterone hormone is taken as a non-human actor, which integrates a network that articulates different fields such as medical / legal / marketing. To that end, ethnographic interviews were conducted with an endocrinologist, two personal trainer and participants of the academy, two trans men who follow up with a medical professional, as well as the analysis of websites, forums, videos, medication packages and scientific articles. During the investigation, we identified two main networks in which testosterone is materialized, which are in constant dispute / coordination, which I named "cycles", in reference to the testosterone cycles demonstrated by some interlocutors of this work. These networks are: 1) Drug-Biomedical Cycle, in which the access to the substance mediated by the medical discourse is highlighted; 2) Drug-Bombed Cycle, in which testosterone circulates through other forms of access, which circumvent medical-patient mediation and / or medical prescription, such as those occurring in gyms and hormone sales / exchanges performed by groups of athletes and / or groups of trans men. The main objective of the work was to demonstrate the different ways in which testosterone is performed in these multiple realities, in the light of Anemarrie Mol's neo-materialistic praxiographic theory, from the descriptions of the network and their respective actors and articulations. Thus, it is demonstrated the dissolution of the nature-culture binarism thinking about the use of testosterone for the materialization of bodies of subjects enrolled in masculinities. And more than that, it exposes that testosterone, by multiplying itself in practices involving both cis and trans men, from the access made difficult by all these subjects to the substance, dissolves the imagined boundaries between such bodies, to the extent that all control over testosterone by the biomedical domain, driven by the need to imitate physiology, demonstrates a moral character that is directly linked to the use of this substance.

La sclérose en plaques (SEP) est une maladie démyélinisante dont les causes ne sont pas encore bien élucidées. Cependant, l’implication des réponses auto-immunes dans la mort des oligodendrocytes engendrant la destruction des gaines de myéline et le disfonctionnement axonal est bien documentée. Les thérapies actuelles utilisant des agents anti-inflammatoires et immunomodulateurs ciblent la réduction de l’inflammation et la progression de la maladie, mais leur efficacité reste limitée et décroit après un long traitement. Toutefois, une nouvelle stratégie de traitement, basée sur la capacité endogène du cerveau à réparer la myéline, commence à voir le jour.L’utilisation des hormones stéroïdes offre une grande opportunité, compte tenu de leurs actions pléiotropiques à la fois au cours du développement et chez les sujets adultes. Notre étude montre que les androgènes et les progéstagènes jouent un rôle très important dans la prolifération des oligodendrocytes et dans la réparation de la myéline. Ces stéroïdes permettent une remyélinisation au niveau des cultures organotypiques du cervelet de souris ou de rats après une démyélinisation par la lysolécithine. En outre, l’utilisation des souris knock-out pour le récepteur de la progestérone (PR-KO) montre l’importance de ce récepteur dans l’effet promyélinisant de la progestérone. De même, l’effet pro-remyélinisant des androgènes passe par l’intermédiaire de leur récepteur nucléaire (AR) puisque la Flutamide, agent antagonisant ces récepteurs, aboli complétement cette action. De même, l’utilisation des souris knock-out pour le récepteur de la progestérone montre l’importance de ce récepteur dans l’effet promyélinisant de la progestérone.L’influence de la testostérone et des ces métabolites sur la réparation de la myéline au niveau du corps calleux est aussi montrée in vivo, en traitant les souris C57Bl/6 par la cuprizone pendant 12 à 14 semaines. Le traitement de ces souris par la testostérone ou ces métabolites 5α- dihydrotestosterone (5α-DHT), 17β-estradiol ou par un agoniste synthétique fort, le 7α-methyl-19-nortestosterone (MENT) pendant 6 semaines, induit un remarquable recrutement des progéniteurs d’oligodendrocytes, suivie par une importante remyélinisation des zones démyélinisées. Le mécanisme d’action de ces androgènes implique le récepteur AR puisque aucun effet promyélinisant n’a été observé chez les souris dont l’AR est muté (tfm : testicular feminization mutation) et les souris ARNes/cre (mutation conditionnelle de l’AR dans les neurones et les cellules macrogliales). Les souris ArKO (Aromatse Knoctout) ne pouvant pas convertir la testostérone en estradiol sont aussi insensibles au traitement par la testérone.Ces travaux montrent que les stéroïdes jouent un rôle très important dans la remyélinisation in vitro et in vivo, fournissant une preuve expérimentale pour une utilisation des stéroïdes dans des essais cliniques futurs visant à réparer la myéline. / Multiple sclerosis (MS) is a very prominent demyelinating disease. The cause of demyelination in MS is not clear, however, it involves autoimmune responses and the death of oligodendrocytes accompanied by myelin destruction and axonal dysfunction. Currently available therapies including anti-inflammatory agents and immunomodulators are targeted to reduce inflammation and disease progression but their limited efficacy further decrease after prolonged treatment.However, another therapeutic strategy has gained recently much interest, is to boost the endogenous capacity of the brain to repair myelin.Steroid hormones offer an opportunity for therapeutic interventions in a wide range of tissue abnormalities because of their multiple actions during development and in adulthood. Our studies show that androgens and progestagens play pivotal role in oligodendrocyte proliferation and subsequent myelination. Androgens or progestagens promote remyelination after lysolecithin mediated myelin insult of organotypic cerebellar slices in culture. Moreover, remyelinating effects of testosterone can be blocked by flutamide, an androgen receptor (AR) inhibitor. Also, the remyelination induced by progestagens is abolished when cerebellar slices are used from progesterone receptors (PR) knockout mice.The influence of testosterone and its metabolites on myelin repair was also evident in toxininduced demyelination in vivo. Long-term cuprizone intoxication (12-14 weeks) of adult C57Bl/6 mice caused chronic and severe demyelination in the corpus callosum. Treatment of these mice with testosterone or its metabolites, particularly 5α-dihydrotestosterone (5α-DHT), estradiol-17β and potent testosterone analog 7α-methyl-19-nortestosterone (MENT) for 6 weeks results in a marked replenishment of the corpus callosum with oligodendrocytes and remyelination. Testosterone fails to stimulate remyelination in mice carrying testicular feminization mutation (Tfm) of AR in the cuprizone model. Furthermore, we demonstrate that testosterone directly targets neuronal and macroglial AR, because the specific ablation of neural AR in (ARNes/Cre) mice prevents the myelin repair in response to testosterone. Interestingly, blocking the conversion of testosterone into estrogens by knocking out the aromatase gene (ArKO mice), also impair the remyelinating effect of testosterone.In conclusion, we provide a strong evidence for a new role of progestagens and androgens in remyelination and thus present a sound experimental support for future clinical trials based on steroid hormone therapy for demyelinating disorders.

The research presented in this thesis examined the issue of the compatibility of strength and endurance training within one training regime, termed concurrent training, in recreational cyclists. Various research designs used in the previous literature resulted in inconclusive findings. The overall aim of this thesis was therefore to examine, in three systematically designed studies, the effects of various components of concurrent training regimes on cycling efficiency and recovery, and to identify some of the mechanisms that may be responsible for the interference or impedance of strength and/or endurance adaptations.

[Truncated abstract]Judgements of physical attractiveness are thought to reflect evolved preferences for a high quality mate. The central aim of this thesis was to investigate the hypothesis that female preferences are adaptations for finding good quality mates and that faces and bodies signal honest information about mate quality. To date, most human mate preference studies have examined face or body attractiveness alone, and many have created stimuli using computer graphic techniques. Throughout these studies, I endeavoured to maximise the biological relevance of my studies by incorporating both face and body attractiveness, and using photographs of individual participants. Most research on attractiveness has focused on faces or bodies separately, while our preferences have evolved based on both seen together. A fundamental requirement of studying face and body attractiveness independently is that there is no interaction between the two. My first study confirmed that the face and body did not interact when an overall attractiveness judgment was made. I also investigated the independent contributions of rated attractiveness of the face and the body to ratings of overall attractiveness. Face and body attractiveness each made significant independent contributions to overall attractiveness in males and females. For both sexes, facial attractiveness predicted overall attractiveness more strongly than did body attractiveness, and this difference was significant in males. ... This study indicates that although current levels of T covary with male mating success, this effect may not be mediated by women's preferences for visual cues to T levels conveyed in static face or body features. The fourth study in this thesis investigated the phenotype-linked fertility hypothesis, which proposes that females obtain reliable information on male fertility from male expression of sexual traits. A previous study of Spanish men reported that facial attractiveness was positively associated with semen quality. I aimed to determine whether this effect was widespread by examining a large sample of Australian men. I also extended my study to determine whether cues to semen quality are provided by components of attractiveness: masculinity, averageness, and symmetry. I found no significant correlations between semen quality parameters and attractiveness or attractive traits. While male physical attractiveness may signal aspects of mate quality, my results suggest that phenotype-linked cues to male fertility may not be generalised across human populations. Together, these studies challenge current methodologies and theories of preferences for secondary sexual traits as honest signals of mate quality. The findings show that it is important to study human mate preferences in biologically relevant contexts, for example by using photographs of both faces and bodies, to maximise the real life application of results. In addition, the findings suggest that male attractiveness does not signal cues to testosterone or semen quality, although testosterone is associated with mating success. The implications of these findings and possible avenues for future research are discussed.

This study examined the differences in the chemical composition, particularly fatty acids, of the lipid extracted from the fibre of bucks, does and castrated goats. The study provides a more detailed understanding of the chemical composition of buck fibre lipid and how it varies throughout the year, and also details the effect of body region and nutrition on the production and chemical composition of lipid from buck fibre. Lipid was extracted with either petroleum ether (non-polar) or chloroform/methanol azeotrope (polar) and analysed by gas chromatography and gas chromatography-mass spectrometry. The more polar solvent system extracted larger amounts of lipid and more of each individual fatty acid. The following buck specific ethyl branched fatty acids were identified: 2-ethylhexanoic, 4-ethylhexanoic, 2-ethyloctanoic, 4-ethyloctanoic, 6-ethyloctanoic, 2-ethyldecanoic, 4-ethyldecanoic, 2-ethyldodecanoic, 6-ethyldodecanoic, 4-ethyldodecanoic, 2-ethyltetradecanoic, 6-ethyltetradecanoic, 4-ethyltetradecanoic, 2-ethylhexadecanoic and 4-ethyloctadecanoic acids. Of these buck specific fatty acids only 4-ethylhexanoic (T), 4-ethyloctanoic, 4-ethyldecanoic, 4-ethyldodecanoic, 6-ethyldodecanoic (T), 4-ethyltetradecanoic, 2-ethylhexadecanoic (T) and 4-ethylhexadecanoic acids have been previously identified or tentatively identified (T) in buck fibre extracts. This shows that the chemical composition of buck fibre lipid is more complex than previously reported, and that it may be more difficult than previously thought to artificially duplicate the odour of the buck. Buck fibre samples had lower average concentrations of 2-methylpropanoic, 2-methylbutanoic, iso-pentadecanoic, anteiso-pentadecanoic, iso-hexadecanoic, anteiso-heptadecanoic, iso-octadecanoic and anteiso-nonadecanoic acids as compared with fibre samples from does, spayed does, or wethers that were castrated at one month of age. The reduced concentrations of these fatty acids in buck fibre extracts were likely to be due to the synthesis of ethyl branched derivatives of iso and anteiso fatty acids. Buck fibre samples had higher concentrations of benzoic acid as compared with fibre samples from does, spayed does, or wethers that were castrated at one month of age. The significance of these results is that non buck specific fatty acids may also make a contribution to the odour of bucks. When fibre samples were collected at various times throughout the year, it was found that the bucks had increased amounts of lipid and ethyl branched fatty acids in fibre samples shorn from March to September, as compared with fibre samples shorn in November and January. The increase in the amount of lipid and ethyl branched fatty acids corresponded with both the rutting period of the buck and the period when the buck odour was increased. This suggests that ethyl branched fatty acids could be pheromones. The variation in lipid content and fatty acid composition was also examined between fibre samples collected from different body regions of the buck during April, as alterations in sebaceous gland activity around the neck during rutting have been reported. It was found that the average amount of lipid in the neck region of the bucks was not statistically higher than the average amounts in the midside and hind regions. However, the ethyl branched fatty acid concentrations were statistically higher in the fibre from around the neck as compared with the fibre from the other body regions, which is consistent with the odour of the buck being most pronounced around the head and neck region. The lipid content and composition of fibre samples from bucks fed high and low quality diets (lucerne and pangola grass, respectively) was examined to determine the effect of nutrition on buck specific components. The high quality diet increased the amount of lipid and ethyl branched fatty acids in fibre samples collected in April from the neck, midside and hind regions, as compared with fibre samples from the corresponding body regions from bucks fed the low quality diet. Thus it may be possible for the pheromone levels of bucks to be increased by simply providing them with good nutrition. The lipid content and ethyl branched fatty acid concentrations of fibre samples increased earlier in the year for the lucerne fed bucks as compared with the pangola grass fed bucks. The lucerne fed bucks had increased concentrations of ethyl branched fatty acids in fibre samples shorn during December to June (6 months) whereas the pangola grass fed bucks had increased concentrations of ethyl branched fatty acids in fibre samples shorn during April to August (4 months). These observations show that good nutrition can result in both the earlier production of ethyl branched fatty acids and an extended period when ethyl branched fatty acids are produced. This suggests that nutrition can be used to manipulate pheromone levels in the buck. The period when the ethyl branched fatty acids were increased corresponded with the period when the plasma luteinizing hormone (LH) and testosterone concentrations, odour and sebaceous gland volume of the bucks were increased, which supports the assumption that ethyl branched fatty acids are involved in odour production and act as pheromones.

<p>This thesis focuses on the evolutionary interactions between birds and a parasite, the mosquito-borne Sindbis virus (Togaviridae, <i>Alphavirus</i>). In conclusion, the results show that the Sindbis virus is widespread among birds, and that the fitness of infected hosts may be reduced by the virus. Furthermore, viruclearance ability was revealed by male plumage traits, and viraemia was related to hormonal- and social status.</p><p>The distribution of Sindbis virus infections among passerine birds was examined in five areas in Sweden. Almost all species tested were infected, and three species of thrushes weridentified as the main hosts. In a series of experimental infections, greenfinches (<i>Carduelis chloris</i>) kept in aviaries were used ahosts. First, the behavioural consequences of an infection were investigated. During the infection, birds tended to reduce thespontaneous locomotion activity, and when escaping from a simulated predator attack, infected birds had reduced take-off spee Furthermore, when comparing virus clearance rate between male greenfinches, I found that males with large yellow tail ornaments hafaster virus clearance rates as compared to those with smaller ornaments. Thus, male virus clearance ability was honestly revealed by the size of an ornament. Moreover, males with experimentally elevated testosterone levels experienced a delayed, but not increased viraemia as compared to controls. When the relationship between male social ranand viraemia was examined, I found no evidence that high-ranked males suffered reduced rank during the infection. Nevertheless, viraemipatterns of males were related to their social rank, so that low-ranked birds had a delayed viraemia as compared to high-ranked birds. </p>

This thesis focuses on the evolutionary interactions between birds and a parasite, the mosquito-borne Sindbis virus (Togaviridae, Alphavirus). In conclusion, the results show that the Sindbis virus is widespread among birds, and that the fitness of infected hosts may be reduced by the virus. Furthermore, viruclearance ability was revealed by male plumage traits, and viraemia was related to hormonal- and social status. The distribution of Sindbis virus infections among passerine birds was examined in five areas in Sweden. Almost all species tested were infected, and three species of thrushes weridentified as the main hosts. In a series of experimental infections, greenfinches (Carduelis chloris) kept in aviaries were used ahosts. First, the behavioural consequences of an infection were investigated. During the infection, birds tended to reduce thespontaneous locomotion activity, and when escaping from a simulated predator attack, infected birds had reduced take-off spee Furthermore, when comparing virus clearance rate between male greenfinches, I found that males with large yellow tail ornaments hafaster virus clearance rates as compared to those with smaller ornaments. Thus, male virus clearance ability was honestly revealed by the size of an ornament. Moreover, males with experimentally elevated testosterone levels experienced a delayed, but not increased viraemia as compared to controls. When the relationship between male social ranand viraemia was examined, I found no evidence that high-ranked males suffered reduced rank during the infection. Nevertheless, viraemipatterns of males were related to their social rank, so that low-ranked birds had a delayed viraemia as compared to high-ranked birds.

Results of the three studies on the speech production of female-to-male transgender individuals (transmen) present phonetic evidence that speech produces the transmen by what I termed triple decoupling. Transmen successfully decouple gender from biological sex. The results of the longitudinal studies exemplified that speakers born and raised female do not necessarily need to have a female voicing source or filter function. Both qualitative changes can he achieved (to different degree) by bringing exogenous testosterone into the system that virilizes both source and filter over time. Moreover, the cross-sectional study showed that articulatory gestures can be modified to move the acoustic targets towards a gendered target one is striving to present. The acoustic manifestations of transmen with different partner attraction offers the next type of decoupling, that between sexual orientation and gender identity. The results of the cross-sectional study imply that female-born individuals attracted to men do not necessarily have to identify as women. They can opt out of this self-identification by selectively adopting features associated with the gay cismale speaking style. This is suggested by the fact that sexual orientation was found to have a significant effect on the durational and spectral quality of fricatives /s/ and /s/, formant values and sentential pitch range. Finally, the longitudinal studies provide evidence for the third type of decoupling, which comes in the form of gender breaking free from physiology. The recurring "reverse J-pattern" of both the transitioning source and filter, as well as the mean fundamental frequency raising above the pitch floor illustrate the fact that transmen do not feel obliged to sound as masculine (as low-pitched and "low-formanted") as testosterone enables them to. This final type of decoupling also serves to demonstrate that many transmen decidedly do not opt in to the binary system of sex / gender even though they are physiologically able to do so. Although LGB speaking styles have been investigated before, this dissertation is the first to discuss a number of acoustic descriptors specifically in transmen's speech and place them into the context of hormone treatment, sexual orientation and disclosure status.

Objective: Lower levels of anabolic hormones in older age are well documented. Several studies suggested that low insulin-like growth factor I (IGF-I) or testosterone levels were related to increased mortality. The aim of the present study was to investigate the combined influence of low IGF-I and low testosterone on all-cause mortality in men. Methods and results: From two German prospective cohort studies, the DETECT study and SHIP, 3942 men were available for analyses. During 21,838 person-years of follow-up, 8.4% (n = 330) of men died. Cox model analyses with age as timescale and adjusted for potential confounders revealed that men with levels below the 10th percentile of at least one hormone [hazard ratio (HR) 1.38 (95% confidence-interval (CI) 1.06–1.78), p = 0.02] and two hormones [HR 2.88 (95% CI 1.32–6.29), p < 0.01] showed a higher risk of all-cause mortality compared to men with non-low hormones. The associations became non-significant by using the 20th percentile as cut-off showing that the specificity increased with lower cut-offs for decreased hormone levels. The inclusion of both IGF-I and total testosterone in a mortality prediction model with common risk factors resulted in a significant integrated discrimination improvement of 0.5% (95% CI 0.3–0.7%, p = 0.03). Conclusions: Our results prove that multiple anabolic deficiencies have a higher impact on mortality than a single anabolic deficiency and suggest that assessment of more than one anabolic hormone as a biomarker improve the prediction of all-cause mortality.

Do endocrine systems influence personality and social behavior? Although animal research has identified several hormone-behavior relationships and the mechanisms that give rise to them, much less is known about hormones and social functioning in humans. This dissertation used three large data sets to investigate whether testosterone and cortisol were related to variation in personality constructs (Study 1), leadership behaviors (Study 2), and economic decision making (Studies 3 and 4). Study 1 revealed that basal testosterone was negatively associated with conscientiousness, basal cortisol was negatively associated with extraversion but positively associated with social dominance orientation, and the interaction between testosterone and cortisol was associated with the implicit power motive. Study 2 found that the testosterone-cortisol interaction predicted leadership behaviors, and Study 3 showed that basal testosterone as well as change in cortisol predicted economic decisions in the Hawk-Dove Game. Finally, Study 4 demonstrated that aggression predicted decisions to punish unfair monetary offers in the Ultimatum and Third Party Punishment Games. Aggression was also related to women's changes in testosterone from before to after the games. Taken together, these studies provide important evidence that testosterone and cortisol are related to personality, leadership, and social decision making. More broadly, this dissertation lays the empirical foundation for further inquiry on the complex biological systems that regulate personality and social behavior.