Submitted by Jaqueline Duarte (1157279@mackenzie.br) on 2018-09-22T15:50:11Z No. of bitstreams: 2 Aline Helen Correa Garcia.pdf: 6202410 bytes, checksum: 2782873913193ac074f57fbdd3e41d91 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Paola Damato (repositorio@mackenzie.br) on 2018-10-17T18:11:59Z (GMT) No. of bitstreams: 2 Aline Helen Correa Garcia.pdf: 6202410 bytes, checksum: 2782873913193ac074f57fbdd3e41d91 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-10-17T18:11:59Z (GMT). No. of bitstreams: 2 Aline Helen Correa Garcia.pdf: 6202410 bytes, checksum: 2782873913193ac074f57fbdd3e41d91 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-08-16 / The present case-control study was based on the assumption that mothers of autistic children could show, in relation to the mothers of the general population, more indicators of anxiety and stress with a consistent profile of cortisol production. To test it we used several classic instruments indicative of anxiety and stress (PANAS: Positive And Negative Affect Schedule; BAI: Beck Anxiety Inventory; IDATE: Trait-State Anxiety Inventory; ISSL: Lipp Adult Stress Inventory; ASR: Adult Self-Report) and salivary cortisol dosages before and after acute stress induction tasks (TSST). The results showed that: 1) the stress and anxiety profile was similar in the 2 groups of mothers (cases and controls) under baseline conditions and after stress induction tasks; 2) immediately after the task of induction of stress the 2 groups of mothers showed increase of negative feelings and decrease of positive feelings being that after 20 minutes they recovered the positive feelings with greater effect among the mothers case; 3) the baseline cortisol dosage of the control mothers was higher and the subsequent dosages followed the same pattern as the group cases; 4) cortisol levels differed from those expected in relation to the stress task since the highest levels were reached in the recovery phase; 5) Emotional activation was higher in the control mothers than in the mothers cases, corroborating the higher cortisol dosages in this group; 6) Mothers presented baseline and post-stress cortisol levels lower than controls. 7) Mothers cases and controls have similar socioeconomic conditions, however the aggravating of caring for a child with developmental disorder, produces an extra burden on mothers cases, leading to resilience with less reactivity to situations of acute stress, contributing to a dysfunction of the HHA axis, with decreased levels of salivary cortisol, before and after the task of stress. 8) other variables need to be controlled, and a larger sample number is also required for data validation. / O presente estudo caso-controle foi baseado no pressuposto de que mães de filhos autistas poderiam mostrar, em relação à mães da população geral, mais indicadores de ansiedade e estresse com condizente perfil de produção de cortisol. Para testá-lo foram utilizados diversos instrumentos clássicos indicativos de ansiedade e estresse (PANAS: Positive And Negative Affect Schedule; BAI: Beck Anxiety Inventory; IDATE: Inventário de Ansiedade Traço-Estado; ISSL: Inventário de sintomas de estresse para adultos de Lipp; ASR: Adult Self-Report) e dosagens do cortisol salivar antes e após tarefas de indução do estresse agudo (TSST). Os resultados obtidos permitiram concluir que: Ansiedade Traço-Estado; ISSL: Inventário de sintomas de estresse para adultos de Lipp; ASR: Adult Self-Report) e dosagens do cortisol salivar antes e após tarefas de indução do estresse agudo (TSST). Os resultados obtidos permitiram concluir que: 1) o perfil de estresse e ansiedade foi similar nos 2 grupos de mães (casos e controles) em condições basais e após tarefas de indução de estresse; 2) imediatamente após a tarefa de indução de estresse os 2 grupos de mães mostraram aumento de sentimentos negativos e diminuição de sentimentos positivos sendo que após 20 minutos recuperaram os sentimentos positivos com efeito maior entre as mães caso; 3) a dosagem do cortisol basal das mães controle foi maior e as dosagens subsequentes seguiram o mesmo padrão do grupo casos; 4) os níveis do cortisol diferiram do esperado em relação à tarefa de estresse já que os maiores níveis foram atingidos na fase que deveria ser de recuperação; 5) A ativação emocional foi maior nas mães controles do que nas mães casos, corroborando com as maiores dosagens de cortisol nesse grupo; 6) As mães casos apresentaram níveis de cortisol basal e após a tarefa de estresse menores do que a das mães controles. 7) Mães casos e controles possuem condições socioeconômicas semelhantes, contudo o agravante de cuidar de uma criança com distúrbio do desenvolvimento, produz uma carga extra sobre as mães casos, levando a resiliência com menor reatividade a situações de estresse agudo, contribuindo para uma disfunção do eixo HHA, com diminuição dos níveis de cortisol salivar, antes e depois da tarefa de estresse. 8) outras variáveis precisam ser controladas, e um número amostral maior também é necessário para validação dos dados.

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Whilst individual differences in circulating hormone levels can influence life history traits throughout an animal’s lifetime, this remains a poorly understood area of research, particularly for wild systems where sufficient sets of individual-based data are rare. This thesis aimed to address this dearth of information by identifying key drivers of hormone variation, as well as exploring potential fitness consequences within a single system of wild red deer (Cervus elaphus) on the Isle of Rum National Nature Reserve in Scotland. It focussed on both androgen (e.g. testosterone) and glucocorticoid (e.g. cortisol) levels, and examined among-individual variation in these two hormone groups from samples collected using both traditional (blood: chapters 3 & 4) and non-invasive (faecal: chapters 5 & 6) methods. Results showed both intrinsic and extrinsic factors to influence an individual’s hormone levels. In general, current or recent environment explained the greatest variation, with both hormone groups exhibiting strong temporal trends at multiple scales. Concentrations changed substantially across an individual’s lifetime as they aged (chapters 5 & 6), and calves born in different years differed in their neonatal testosterone levels (chapter 3). Hormone levels also varied across the year, showing clear seasonal cycles which peaked during key reproductive events: the calving season in females (chapter 6) and the rut in males (chapter 5). An individual’s current life history state was also important, particularly a female’s reproductive state (chapter 6). Whilst there was some evidence of maternal effects on neonatal hormone levels (chapter 3) these were not extensive, and maternal hormone concentrations did not appear to influence those in their new-born calves (chapter 6). There was, however, evidence of neonatal circulating testosterone levels being heritable, and despite overall differences between the sexes the underlying genetic architecture of this trait did not differ between male and female calves (chapter 4). Associations were also found between an individual’s hormone levels and their fitness, although these consequences were only apparent in short-term fitness measures or proxies such as reproductive behaviour (e.g. male reproductive effort in chapter 5). Effects were also not ubiquitous within the population. Whilst a calf’s circulating testosterone levels indicated their probability of surviving their first year of life, these effects were only apparent in firstborn males, a group which is particularly vulnerable to mortality (chapter 3). In general, this thesis suggests that the fitness consequences identified by broad-scale hormone manipulation studies can still be found when looking at subtle individual-level differences. The limited evidence of persistent hormone phenotypes (indicated by the lack of among individual variance for most measures, chapter 5 & 6) does, however, emphasise the importance of repeatedly sampling individuals before drawing extensive conclusions about fitness consequences.

This doctoral dissertation addresses the biological and psychological components of financial decision-making for individuals. As such, it directly examines intrinsic human traits that are related to financial performance, rather than following the standard approach of inferring said traits from aggregate market data. Specifically, this dissertation examines the relation of personality traits, testosterone levels, and cortisol levels to financial choices and outcome under short-term (trading) and long-term (investing) investment horizons. Subjects are recruited from advanced courses in finance at Florida International University. During the course of a semester (fourteen weeks) they complete a portfolio formation and rebalancing task, and answer a personality questionnaire. Additionally, subjects complete a series of trading simulations during the early morning of a preset date, and provide saliva samples. The saliva samples are analyzed for levels of testosterone and cortisol at a University lab facility. The relation of personality scores, testosterone levels, and cortisol levels to financial choices and outcomes is analyzed via linear regressions and Student’s t-tests. The results show that personality factors associated with detrimental life quality, such as paranoia, are related to long-term investment decisions associated with increased portfolio risk and return. Additionally, the levels of testosterone and cortisol play a significant role in initial portfolio formation decisions, but not in subsequent portfolio allocation decisions. As such, the results show that hormone levels contribute to initial long-term investment choices, but personality traits play a much greater role in portfolio maintenance. Alternatively, the results show that testosterone and cortisol levels play a significant role in many aspects of short-term investment, including the decision to buy or to sell, and timing preferences. Overall, the results show that hormone levels and personality traits play significant and distinctive roles in many aspects of financial decision-making. Therefore, this dissertation provides important implications for the practice and the study of finance, including information that could be used to make more rational financial choices, and to develop financial models with more realistic assumptions about investor behavior.

Dysregulation of the hypothalamo-pituitary-adrenal (HPA) axis activity has been commonly observed among breast cancer patients and has been linked to adverse health consequences. However, whether these alterations persist long after the cancer diagnosis has not been well-documented. In the first study, the diurnal cortisol rhythms and the cortisol stress response of breast cancer survivors who had completed all local and/or systemic adjuvant therapy with the exception of hormonal therapy were compared to those of women without a history of cancer. The Trier Social Stress Test was used to elicit a moderate stress response and the subjective levels of stress of participants were recorded using visual analog scales. The results indicate similar diurnal patterns in both groups; however, significant differences in stress reactivity were noted, with breast cancer survivors displaying a relatively flat profile following the acute stress induction. Subjective levels of psychological stress were similar in both groups, indicating that the subjective appraisal did not account for the blunted cortisol stress response. In the second study, the impact of the stressful life events that happened during the previous year on the cortisol stress response was analyzed in the same groups of participants. The frequency of stressful life events as well as their subjective impact was documented using the Life Experience Survey. Results suggest no group differences between the total number of stressful life events and their perceived effect. However, the number of stressful life events and their perceived impact correlated negatively with the peak cortisol concentration in breast cancer survivors. The results suggest that the cumulative effect of stressful life events contribute significantly to the low levels of cortisol reported in breast cancer survivors following a stressful situation. Together, these studies emphasize that breast cancer survivors are at risk of presenting a subtle alteration of their HPA axis activity when their system is challenged and that an accumulation of stressors plays a role in this dysregulation. These results reinforce the need for interventions intended to reduce the levels of psychological stress experienced by breast cancer survivors.

Maternal iron deficiency is a world wide and major public health issue. Despite recent researchers’ interest related to this topic, its impact in the offspring still remains unclear. The aim of this study is to understand the impact of maternal iron deficiency on the auditory functions and serum cortisol levels in the young and adult guinea pig at post-natal day (PNd) 24 and PNd84, respectively. Pregnant guinea pigs were given an iron deficient (ID) or iron sufficient (IS) diet during gestation and lactation. An iron sufficient diet was provided to all pups after weaning day. No significant difference was observed in the hearing threshold and latencies in siblings from both groups at PNd24 and PNd84. However, ID offspring showed a significant higher interpeak latency I-IV at 100 dB than IS pups at PNd24. ID offspring also had significant elevated cortisol levels at PNd24 compared to IS control group. Maternal iron deficiency affects negatively the auditory functions and raises the serum cortisol levels, a biomarker of stress in the offspring.

Maternal iron deficiency is a world wide and major public health issue. Despite recent researchers’ interest related to this topic, its impact in the offspring still remains unclear. The aim of this study is to understand the impact of maternal iron deficiency on the auditory functions and serum cortisol levels in the young and adult guinea pig at post-natal day (PNd) 24 and PNd84, respectively. Pregnant guinea pigs were given an iron deficient (ID) or iron sufficient (IS) diet during gestation and lactation. An iron sufficient diet was provided to all pups after weaning day. No significant difference was observed in the hearing threshold and latencies in siblings from both groups at PNd24 and PNd84. However, ID offspring showed a significant higher interpeak latency I-IV at 100 dB than IS pups at PNd24. ID offspring also had significant elevated cortisol levels at PNd24 compared to IS control group. Maternal iron deficiency affects negatively the auditory functions and raises the serum cortisol levels, a biomarker of stress in the offspring.

Many animals, including zebrafish (Danio rerio), form social hierarchies as a result of competition for limited resources. Socially subordinate fish experience chronic activation of the hypothalamic-pituitary-interrenal (HPI) axis, leading to prolonged elevation of plasma cortisol, the glucocorticoid end-product of HPI axis activation. Elevated cortisol levels can reduce cellular proliferation and neurogenesis in the brain. Thus, the present study tested the hypothesis that social stress suppresses cellular proliferation in the brain of subordinate zebrafish via a cortisol-mediated mechanism. Cellular proliferation was assessed using the incorporation of 5-bromo-2'-deoxyuridine (BrdU), a thymidine analogue, as a marker. After 48 and 96 h of social interaction, significantly lower numbers of BrdU-positive cells were present in the forebrain of subordinate male zebrafish compared to dominant or control fish, suggesting a suppression of cellular proliferation in fish experiencing chronic social stress. Treatment of interacting male zebrafish with metyrapone, a cortisol synthesis inhibitor, attenuated the suppression of cellular proliferation in subordinate fish. Subordinate female zebrafish did not experience elevation of plasma cortisol or suppression of cellular proliferation in the forebrain. Collectively, these data provide evidence that cortisol plays a role in regulating cellular proliferation in the forebrain of male zebrafish during social interactions.

Zebrafish, Danio rerio, are able to survive exposure to extreme acidity (pH 4). Because previous studies demonstrated that disruption of ionic balance during exposure to acidic water is the major cause of mortality in acid-sensitive freshwater species, the focus of this thesis was to characterize the molecular mechanisms enabling zebrafish to maintain their Na+ homeostasis following exposure to acidic water. Initial findings (Chapter 2) demonstrated that branchial mRNA expression of selected isoforms of claudins, major components of tight junctions, are altered in an isoform-dependent manner, suggesting the potential regulation of epithelial permeability to minimize ion loss. Concurrently, a marked stimulation of Na+ uptake was observed in adults and larvae following acid-exposure. Because of the uniqueness of this response (increasing Na+ uptake in acidic water) among freshwater teleosts, the mechanisms related to Na+ uptake and its stimulation were investigated further (Chapters 3 - 7). Pharmacological treatments and gene knockdown approaches revealed that a functional metabolon consisting of an apically expressed Na+-H+-exchanger (NHE3b) in association with an apically expressed ammonia-conducting channel (Rhcg1), enables Na+ uptake in acidic water. During chronic (>1 day) exposure to acidic water, cortisol (via glucocorticoid receptors) and catecholamines (via β-adrenergic receptors) are involved in stimulating Na+ uptake. Although catecholamines may act on both NHE3b and Na+-Cl- co-transporter (NCC), the effects of cortisol on Na+ uptake are mediated primarily by activation of NHE3b. On the other hand, during acute (<3 h) exposure to acidic water, cortisol does not appear to affect Na+ uptake; rather, the stimulation of Na+ uptake appears to be mediated by angiotensin II and catecholamines. Cyclic AMP (cAMP), a signalling molecule synthesized following the activation of β-adrenergic receptors, is critically involved in stimulating Na+ uptake, likely via activation of NHE3b and NCC. In agreement with this idea, ionocytes that express NHE3b also express high levels of β-adrenergic receptor (propranolol binding sites) as well as trans-membrane adenylyl cyclase (forskolin binding sites). Taken together, the results of this thesis provide fresh insight into the mechanisms of osmoregulation in freshwater (FW) fish. In particular, the data reveal the presence of complex pathways regulating Na+ uptake in zebrafish exposed to acidic water. The relative importance of the various pathways depends in part on the duration of exposure; acute versus chronic.

Polypterus senegalus is a basal ray-finned fish that breathes both air and water, and can tolerate life on land for extended periods. Previous research reported that P. senegalus held on land for several months exhibited lower growth rates than counterparts fed equal amounts of food but held under aquatic conditions. Because chronic stress can impair growth, the present research aimed to determine whether P. senegalus experience stress when held under terrestrial conditions. P. senegalus were held for 1, 2, 4, or 8 weeks in aquatic or terrestrial conditions, following which tissues were sampled for analysis. Growth rates were significantly lower in fish held under terrestrial conditions, but neither plasma cortisol levels nor transcript abundances of genes of the stress axis differed between aquatic and terrestrial fish. Terrestrial fish exhibited lower transcript abundance in liver of the growth regulator insulin-like growth factor 1, and higher transcript abundances in muscle of myostatin, an inhibitor of muscle growth, and muscle RING-finger protein-1, an indicator of muscle breakdown. With knowledge from anecdotal observations that P. senegalus tend to be aggressive when housed with a conspecific, P. senegalus were held in a second experiment in pairs for 6 d to investigate stress axis function. Clear differences in territorial and aggressive behaviours between the individuals in a pair were consistent with one fish being dominant over the other, subordinate fish. Dominant fish tended to have higher cortisol levels than subordinate fish, although the difference was not significant, and cortisol levels were correlated with the frequency of aggressive and territorial behaviours, regardless of social status. However, transcript abundances of stress axis genes generally did not differ between dominant and subordinate fish. Collectively, these results suggest that P. senegalus is unusually tolerant of conditions that serve as stressors in other fish species, including emersion and social interactions.