Mental toughness has received extensive research attention in recent years because of its intuitive and theoretical association with successful performance. However, several significant omissions in understanding remained. This thesis aimed to address these gaps through various research approaches and methodologies, collectively resulting in a biopsychological perspective. The primary objectives were to provide a more holistic perspective of mental toughness and generate quantitative support for the various biological (2D:4D) cognitive-affective (self-structure), physiological (cortisol response) and behavioural (performance) differences that have been associated with the construct. The findings suggested that mental toughness is a multifaceted construct and manifests in several areas of human functioning; specifically, a particular cognitive-affective profile may underlie mental toughness (they possess a positive self-concept and a particular self-structuring style, namely integration). Furthermore, levels of cortisol during a competitive event (a physiological indicator of perceived stress levels) were significantly negatively related to mental toughness, suggesting that mentally tough individuals have a reduced perception of threat in competitive situations (giving support for the notion that they perceive competition or stress as a potential challenge for personal growth and improvement). An objective marker of mental toughness was also supported; specifically, 2D:4D ratio (indicative of prenatal testosterone levels) related significantly with scores on a mental toughness scale, giving support for the biological underpinning of the construct and an objective marker of mental toughness. Finally, two case examples are provided to demonstrate the usability of these important markers (cognitive, biological and physiological) in an applied context.

Thesis (PhD (Psychiatry))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Pregnancy is often accompanied by distressing psychological symptoms such as anxiety. These symptoms may result from changes in cognitive-affective processing, which in turn reflect hormonal changes during this time. However, findings on associations between psychological distress, cognitive-affective changes and hormones have been inconsistent. Furthermore, few studies have investigated the neural circuitry underlying distress and cognitive-affective processing in pregnancy. The prefrontal cortex (PFC) plays a specific role in regulating emotion. Determining the relationship between these changes in cognitive-affective processing and in prefrontal circuitry is important, given the high prevalence of depressive and anxiety disorders in pregnancy. The overall objective of this study was to investigate distressing psychological symptoms and their association with cognitive-affective processes and neurobiological changes over the course of pregnancy. Pregnant women with low risk singleton pregnancies were recruited from Midwife Obstetric Units in the Western Cape. Non-pregnant healthy controls were also recruited from the same demographic area. Distress levels were assessed using the K-10, Spielberger State -Trait Inventory, and Perceived Stress Scale. Subjectively experienced cognitive ability was asked about. Objective cognitive ability was assessed using standardized neuropsychological tests. Selective attention to threat such as fear and anger was assessed using a Facial Stroop Task. Neural circuitry was assessed using Near-Infrared Spectroscopy while viewing dynamic emotional facial expressions of threat (Emotion Recognition Task). Glucocorticoid (cortisol) and gonadal hormonal levels (estrogen, progesterone, and testosterone) were also determined at each trimester of pregnancy. Associations between distressing psychological symptoms, cognitive-affective processes and neurobiology were assessed using standard statistical methods. The main findings to emerge from this research were that, 1. pregnant women had significantly higher trait anxiety at trimester 2, compared to trimester 1 of pregnancy; 2. compared to non-pregnant women, pregnant women paid significantly more attention to fearful faces across trimesters, suggesting altered cognitive-affective processing in pregnancy compared to non-pregnancy; 3. pregnant women demonstrated significantly increased PFC activation in response to fearful and angry faces (all trimesters) that was particularly evident at trimester 2; 4. the PFC activation was, across trimesters, significantly correlated with distress and selective attention to threat; and 5. the PFC activation was, across trimesters, also significantly associated with increased glucocorticoid and gonadal hormone levels. The main findings of this study are consistent with previous literature insofar as distress has previously been associated with altered cognitive-affective processing and prefrontal cortex activation, but extend it by showing that emotional regulation is altered in pregnancy compared to the non-pregnant state. These data provide an important insight into distressing psychological symptoms and their associations with cognitive-affective processes, and changes in neural circuitry and in hormone levels in pregnancy. These findings are also the first to show that structures involved in emotional processing (e.g. the PFC) also play a role in the regulation of affect in pregnancy. Future research should explore the causal mechanisms underlying altered emotional regulation in pregnancy, and include pregnant women that are clinically depressed or anxious as comparison subjects. / AFRIKAANSE OPSOMMING: Swangerskap word dikwels geassosieër met stres-veroorsakende sielkundige simptome soos angstigheid. Hierdie simptome mag die gevolg wees van veranderinge in kognitief-affektiewe prosessering, wat op sy beurt mag dui op hormonale veranderinge. Bevindinge oor assosiasies tussen sielkundige stres, kognitief-affektiewe prosessering en hormone is tot dusver onbeslis. Voorts was min studies gerig op die neurologiese meganika onderliggend aan stres en kognitief-affektiewe prosessering tydens swangerskap. Die prefrontale korteks (PFK) het 'n spesifieke rol in die regulering van emosie. Die bepaling van spesifieke assosiasies tussen veranderinge in kognitief-affektiewe prosessering en in prefrontale regulering is belangrik, gegewe die hoë voorkoms van toestande soos depressie en angssteurings tydens swangerskap. Die doel met hierdie studie was 'n ondersoek na assosiasies tussen stres-veroorsakende sielkundige simptome, kognitief-affektiewe prosesse en neurobiologie tydens swangerskap. Swanger vroue met lae risiko enkel-swangerskappe is gewerf by klinieke in Wes-Kaapland. Gesonde nie-swanger vroue is uit dieselfde omgewing gewerf as kontroles. Angs-vlakke is geevalueer met behulp van die K-10; die Spielberger State-Trait Inventory en die Perceived Stress Scale. Vrae is tydens ondersoeke gevra oor subjektief-ervaarde kognitiewe vermoë. Voorts is kognitiewe vermoë geëvalueer met behulp van gestandardiseerde neurosielkundige toetse. Hierbenewens is selektiewe aandag aan bedreigende gesigte wat vrees en woede toon, geëvalueer met behulp van 'n Facial Stroop Task. Neurologiese funksie is geëvalueer met gebruik van Na-Infrarooi Spektroskopie terwyl dinamiese bedreigende emosionele gesigsuitdrukkings vertoon is (Emotion Recognition Task). Gluko-kortikoïed (kortisol) en geslagshormoonvlakke (estrogeen, progesteroon, en testosteroon) is gemeet tydens elke trimester. Verwantskappe tussen stresvolle simptome, kognitief-affektiewe prosessering en neurobiologie is geëvalueer met standaard statistiese metodes. Die hoofbevindinge het op die volgende gedui: 1. swanger vroue het betekenisvolle hoër trait angs-vlakke getoon in trimester 2, vergeleke met trimester 1; 2. vergeleke met nie-swanger vroue, het swanger vroue beduidend meer aandag geskenk aan angstige gesigsuitdrukkings tydens elke trimester wat mag dui op veranderde kognitief-affektiewe prosessering tydens swangerskap vergeleke met nie-swangerskap; 3. swanger vroue het beduidend hoër PFK aktivering getoon teenoor angstige en kwaai gesigte in alle trimesters, maar veral in trimester 2; 4. swanger vroue se PFK aktivering het, in alle trimesters, beduidend gekorreleer het met stres-vlakke en selektiewe aandag teenoor bedreigende stimuli; en 5. swanger vroue se PFK aktivering het, in alle trimesters, ook 'n beduidende verwantskap getoon met verhoogde gluko-kortikoïed en geslagshormoonvlakke. Die hoofbevindinge in hierdie studie stem ooreen met vorige literatuur wat aangedui het dat daar 'n verband is tussen stres en veranderinge in kognitief-affektiewe prosessering en in prefrontale korteks aktivering, maar dui verder op veranderinge in emosionele regulering tydens swangerskap vergeleke met nie-swangerskap. Die data bied 'n belangrike insig in stres-veroorsakende sielkundige simptome; hul verwantskap met kognitief-affektiewe prosesse; veranderinge in neurologiese netwerke; en veranderinge in hormoonvlakke tydens swangerskap. Sover bekend is dit ook die eerste keer bevind dat strukture wat betrokke is by emosionele prosessering (bv. die PFK), ook betrokke is in die regulering van emosie tydens swangerskap. Dit is belangrik dat toekomstige navorsing die onderliggende meganismes wat veranderinge in emosionele regulering teweeg bring, ondersoek. Verdere ondersoek om hierdie veranderinge in swanger depressie-lyers of diegene met angssteurings te vergelyk is ook van belang.

Doctor of Philosophy / Department of Diagnostic Medicine/Pathobiology / Manuel Borca / Stephen Higgs / African swine fever (ASF) is a lethal hemorrhagic disease of swine caused by a double-stranded DNA virus. ASFV is endemic in Sardinia and Saharan Africa and has been recently expanded from the Caucasus to Eastern Europe. There is no vaccine to prevent the disease and current control measures are limited to culling and restricted animal movement. Swine infected with attenuated strains are protected against challenge with a homologous virulent virus, but there is limited knowledge of the host immune mechanisms generating that protection. Swine infected with Pret4 virus develop a fatal severe disease, while a derivative strain lacking virulence-associated gene 9GL (Pret4Δ9GL virus) is completely attenuated. Swine infected with Pret4 Δ9GL virus and challenged with the virulent parental virus at 7, 10, 14, 21, and 28 dpi showed a progressive acquisition of protection (from 40% at 7 dpi to 80% at 21 and 28 dpi). This animal model was used to associate the presence of host immune response and protection against the challenge. Anti-ASFV antibodies and cytokines in serum, as well as ASFV-specific IFN-γ production in PBMCs, were assessed in each group. Interestingly, with the exception of ASFV-specific antibodies in the surviving swine challenged at 21 and 28 dpi, no solid association between any of the parameters assessed and the extent of protection could be established. These results were corroborated using a similar model based on the use of a rationally attenuated derivative of the highly virulent strain Georgia 2007. These results, encompassing data from 114 immunized swine, underscore the complexity of the system under study where it is very plausible that protection against disease or infection relies heavily on the concurrence and or interaction of different host immune mechanisms.

In daily life there are numerous experiences and events that divert people's attention and cause stress, which may be linked with aspects of ill-being and lowered well-being. Mindfulness meditation may alleviate such issues. Mindfulness can be summarized as a form of awareness and attention in the present that is characterized by an open-minded and non-judgemental perspective, and meditation as a group of practices that engage many of the same processes and may involve mindfulness. There is evidence that both mindfulness and mindfulness meditation are associated with activity in brain regions relating to, for example, attention, emotion-regulation, and bodily awareness. Consequently, mindfulness meditation was hypothesized in the present study to improve attention as measured by the Attention Network Test, and decrease negative affect as measured by the Positive and Negative Affect Schedule when compared to a control condition. The mindfulness meditation instructions employed were largely based on the work of Kabat-Zinn (1982). 14 participants were recruited to the study, and 7 of them completed the experiment. 3 participants were randomized to the experimental group, and 4 to the control group. Results were largely contrary to the hypotheses, with only executive attention having statistical significance (p < .05) and supporting one hypothesis. Although effect sizes were on average large for the variables of the study, the small sample size may have limited the power and increased the risk for type-II errors.

The purpose of the present investigation was to compare the psychological factors related to drug use by college athletes on seven drug categories. A questionnaire was given to male and female Division I college athletes asking them about their use of drugs. The frequency, intensity and duration of use/non-use was used to divide subjects into high and low/nonuser categories. Dependent measures included the Profile of Mood States, Coopersmith Self-Esteem Inventory and questions assessing athlete stress. A multivariate analysis of variance(MANOVA) was conducted in a 2 x 2 (alcohol high/low, non-user x male/female) design to distinguish significant differences on the POMS and stress questions followed by univariate ANOVA's. A separate ANOVA was run on Coopersmith's Self-Esteem Inventory. Results indicated that high alcohol users scored significantly higher on anger, fatigue and vigor than low/non-users. Significant differences were found between males and females on the pressure felt from coaches to perform well.

More than a decade has passed since Agnew (2005) introduced his General Theory of Crime and Delinquency (GTCD). Despite this interval, GTCD remains a relatively untested theory. Drawing on previous testing efforts, the current research provides a systematic assessment of Agnew's theoretical propositions. It also provides only the second empirical examination of Cochran's (2015) extension of GTCD, which incorporates religion as a sixth distinct life domain. Nested negative binomial regression modeling and Poisson regression modeling are used to assess the effects of life domains on several diverse forms of self-reported criminal behavior at two distinct stages of development: adolescence and adulthood. Data are drawn from two waves of the second generation of the Kaplan Longitudinal and Multigenerational Study. Consistent with prior empirical tests, results provide mixed support for theoretical propositions, highlighting the complexity of Agnew’s initial theory. Specifically, general support is provided for the direct effects of both theories’ variables, indicating they are important to the explanation of crime. Also, in line with Cochran's findings, initial observed effects of religious variables on criminal behavior are reduced to non-significance when all other predictors are introduced in most regression models, hinting that the incorporation of such variables may be incongruous with Agnew's chosen method of theoretical integration. However, religious variables emerge as significant predictors of general crime during adulthood, suggesting that the relationship between these variables and crime is more complex than anticipated. Additionally, strong support is found for the proposition that the effects of life domains are primarily contemporaneous. Results offer weaker support, however, for the assertion that life domain effects are largely mediated by constraints against crime and motivations towards it. Policy implications for the creation of theoretically-informed crime prevention and intervention strategies tailored to specific developmental stage are discussed.

The philosophical and scientific studies of consciousness are two disciplines having much to learn from one another. On the one hand, a science of consciousness involves taking an objective approach to what is essentially a subjective phenomenon, giving rise to tricky conceptual and methodological issues, ones an analytic philosopher is perhaps best equipped to handle. On the other hand, a wealth of data now exists concerning the neural basis of consciousness. Such data, interpreted properly, can confirm or disconfirm philosophical views on consciousness, helping adjudicate debates thus far intractable. This dissertation explores some ways in which the philosophy and science of consciousness can be of mutual benefit to one another.

This study had three main purposes. First, the relationship between Processing Speed (Gs) and poor word recognition skills was examined. Second, various formats of processing speed tests that measure different types of processing speed (i.e. naming facility, perceptual speed, semantic speed, attention and concentration) were administered to determine what aspects of Gs were more strongly correlated with word reading performance. Pearson correlations and coefficients of determination were used to evaluate the strength of the relationships and the shared variance. Third, the study sample was evaluated to determine what percentage of the poor readers participating in the study had slow processing speed.Forty-four students in grades 1-3, ages six- to ten-years old were administered the Woodcock-Johnson III Achievement reading tests of Letter-Word Identification, Reading Fluency, and Word Attack. The subjects were additionally administered the Woodcock-Johnson III Cognitive Abilities tests of Verbal Comprehension, Visual-Auditory Learning, Sound Blending, Visual Matching, Numbers Reversed, Decision Speed, Rapid Picture Naming, Pair Cancellation, and Cross Out.The results of the study indicated processing speed, as measured by the Gs Cluster score, was strongly correlated with word reading, r = .749, r2=.56. The Gs tests of Visual Matching, (r = .663, r2 = .44) and Decision Speed (r = .811, r2 = .66) were most strongly correlated with poor word reading skill. The Basic Reading Skills Cluster and the Test of Letter-Word Identification were both moderately correlated at various strengths with different formats of Gs tests. Tests of Visual Matching, Rapid Picture Naming, Pair Cancellation and Cross Out all had a moderate, significant correlation.Lastly, 47% of the poor readers (SS<85 on any of the measures of>reading) also had low Gs scores (SS<85).The results from the study demonstrate the need for further exploration of the impact of poor Gs on the development of reading skills, as well as determination of the most effective interventions for poor readers with slow processing speed.

Ebola virus (EBOV) is a zoonotic pathogen which causes a fulminant hemorrhagic fever and results in up to 90% fatality. Despite efforts over the past 38 years, a licensed prophylactic or post-exposure option remains unavailable. Several experimental vaccines have already demonstrated protection from lethal EBOV disease in nonhuman primates (NHPs). However, attempts to translate this research from bench to bedside have been hampered, since the immune responses that correlate with protection against EBOV are not well-defined. Without this information, it is not possible to reliably predict the efficacy of vaccines or treatments in humans without lethal challenge. The goal of this thesis is to determine the immune parameters that are predictive of protection against EBOV. Due to the rapid speed of EBOV pathogenesis, it was originally hypothesized that a rapid and robust CD8+ T-cell response must be crucial for survival. Using a previously-characterized adenovirus-vectored Ebola vaccine (Ad5-optGP), transgenic/knockout C57BL/6J mice with ablation for selected immune responses were vaccinated and challenged 28 days later. Surprisingly, while CD8+ T-cell knockout mice survived infection, B-cell knockout mice did not, indicating that the antibody response played a critical role in protection. Humoral and cell-mediated responses were compared between survivor and moribund guinea pigs and NHPs from previous vaccination and post-exposure therapy experiments, either with Ad5-optGP or a vesicular stomatitis virus (VSV)-vectored vaccine (VSVΔG/EBOVGP). Circulating EBOV glycoprotein (GP)-specific IgG antibody levels were the best correlation for protection independent of vaccine platform or timing of exposure (p<0.0001), strongly supporting the role of antibody responses in the control of EBOV infection. To demonstrate that antibodies are also responsible for protection, three previously-characterized monoclonal antibodies recognizing different GP epitopes were combined into a cocktail (ZMAb). Initiation of ZMAb treatment 1 and 2 days post infection (dpi) with EBOV protected 100% and 50% of NHPs, respectively. These results provide a reliable measure for predicting protection from EBOV in three commonly used animal models, and present a strong case for the use of antibodies as an effective post-exposure treatment. This knowledge will ultimately help in the development and validation of a clinical product against EBOV infection.

Made available in DSpace on 2016-08-03T16:34:28Z (GMT). No. of bitstreams: 1 Henrique Adam Pasquini.pdf: 888682 bytes, checksum: 3ba99f5587a48f9130c806e394f12f25 (MD5) Previous issue date: 2013-08-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Attention is probably one of the oldest theoretical constructs in Psychology. In the Eastern countries, meditation has been seen as a group of technics that goals to train people to focus attention. This research aims to check its electrophysiological correlates, taking into consideration the long term changes accompanying regular practice of meditation. We have used modern technics of high resolution electroencephalography analyze slow potentials, power in various bands, and event-related band-power. We recorded the EEG using a 128-channel montage, in 31 subjects (17 meditators). We analyzed the type of meditation related to a Zen Buddhist practice of the Soto school, which belongs to the group of mindfulness meditation. The goal of the research was to verify if the power on the beta band would rise. However, not quite what we expected, no significant changes were detected on the beta band. On the other hand, the main finding of this research was that the weekly practice of meditation is associated with a rise in the induced relative theta band power, an increase in the ratio of induced power (theta/beta), and an increase in the ratio of the induced relative band power (theta/beta), which occurred during an adapted meditation task. We also noticed that the practice of meditation was related to a decrease of the alpha peak frequency during the task of focused attention. We discuss the decrease of the alpha peak frequency with respect to the hypothesis of brain efficiency. On the other hand, the increase of the induced relative theta band power and of the ratio of theta/beta induced power bands, during the adapted meditation task, suggests that the plain attention type of meditation is rather related to a deliberate loss of attention, by the permissive distractions of the meditators. / A atenção talvez seja um dos constructos teóricos mais antigos da psicologia. A meditação, por sua vez, tem sido vista no ocidente como um conjunto de técnicas que objetivam o treino da focalização da atenção. Esta pesquisa teve como principal objetivo verificar os correlatos eletrofisiológicos das modificações da atenção em longo prazo em meditadores regulares. Utilizamos as modernas técnicas de eletroencefalografia de alta resolução aplicadas aos potenciais lentos, espectros de potência, potências relacionadas aos eventos. Para obtenção dos registros encefalográficos nós utilizamos uma montagem de 128 canais, em 31 sujeitos (17 meditadores). A meditação estudada compreendeu uma prática zen budista da escola Soto que pertence ao grupo das meditações da atenção plena . A motivação deste estudo foi verificar se a potência na faixa beta se apresentaria aumentada nos meditadores. No entanto, ao contrário do que esperávamos, nenhuma alteração significativa foi encontrada na frequência beta. Em contrapartida, o principal achado do estudo foram correlações entre a frequência da prática semanal da meditação e: o aumento da potência teta induzida relativa, aumento da razão entre potências induzidas (razão teta/beta), e o aumento da razão entre potências induzidas relativas (razão teta/beta) durante nossa tarefa que caracterizou uma meditação adaptada . Verificamos ainda que a prática meditativa apresentou correlação com a diminuição da frequência de pico da faixa alfa durante a tarefa de atenção focada. Discutimos essa diminuição da frequência de pico alfa com respeito a hipóteses de eficiência cerebral. Já o aumento da potência teta induzida relativa, da razão teta/beta das potências induzidas, tomando seus valores absolutos e relativos, bem como o aumento da entre potências induzidas, tomando seus valores relativos, durante a tarefa de observação passiva, sugere que o estado meditativo da atenção plena está muito mais relacionado à permissividade de distrações por parte dos meditadores, com uma diminuição deliberada da atenção.