Using mouse dynamics to assess stress during online exams

"Lecture notes in computer science series", ISSN 0302-9743, vol. 9121

Stress induced risk-aversion is reverted by D2/D3 agonist in the rat

Stress exposure triggers cognitive and behavioral impairments that influence decision-making processes. Decisions under a context of uncertainty require complex reward-prediction processes that are known to be mediated by the mesocorticolimbic dopamine (DA) system in brain areas sensitive to the deleterious effects of chronic stress, in particular the orbitofrontal cortex (OFC). Using a decision-making task, we show that chronic stress biases risk-based decision-making to safer behaviors. This decision-making pattern is associated with an increased activation of the lateral part of the OFC and with morphological changes in pyramidal neurons specifically recruited by this task. Additionally, stress exposure induces a hypodopaminergic status accompanied by increased mRNA levels of the dopamine receptor type 2 (Drd2) in the OFC; importantly, treatment with a D2/D3 agonist quinpirole reverts the shift to safer behaviors induced by stress on risky decision-making. These results suggest that the brain mechanisms related to risk-based decision-making are altered after chronic stress, but can be modulated by manipulation of dopaminergic transmission.

The role of IFNγ in higher brain function: in health and under chronic stress

Tese de Doutoramento em Ciências da Saúde

Toxicity induced by a metal mixture (Cd, Pb and Zn) in the yeast Pichia kudriavzevii: The role of oxidative stress

The present work aims to contribute for the elucidation of the role of oxidative stress in the toxicity associated with the exposure of Pichia kudriavzevii to multi-metals (Cd, Pb and Zn). Cells of the non-conventional yeast P. kudriavzevii exposed for 6 h to the action of multi-metals accumulated intracellular reactive oxygen species (ROS), evaluated through the oxidation of the probe 2,7-dichlorodihydrofluorescein diacetate. A progressive loss of membrane integrity (monitored using propidium iodide) was observed in multi-metal-treated cells. The triggering of intracellular ROS accumulation preceded the loss of membrane integrity. These results suggest that the disruption of membrane integrity can be attributed to the oxidative stress. The exposure of yeast cells to single metal showed that, under the concentrations tested, Pb was the metal responsible for the induction of the oxidative stress. Yeast cells coexposed to an antioxidant (ascorbic acid) and multi-metals did not accumulate intracellular ROS, but loss proliferation capacity. Together, the data obtained indicated that intracellular ROS accumulation contributed to metal toxicity, namely for the disruption of membrane integrity of the yeast P. kudriavzevii. It was proposed that Pb toxicity (the metal responsible for the toxic symptoms under the conditions tested) result from the combination of an ionic mechanism and the intracellular ROS accumulation.

Infants’ behavioral and physiological profile and mother–infant interaction

This study aims to (a) identify and profile groups of infants according to their behavioral and physiological characteristics, considering their neurobehavioral organization, social withdrawal behavior, and endocrine reactivity to stress, and to (b) analyze group differences in the quality of mother–infant interaction. Ninety seven 8-week-old infants were examined using the Neonatal Behavioral Assessment Scale and the Alarm Distress Baby Scale. Cortisol levels were measured both before and after routine inoculation between 8 and 12 weeks. At 12 to 16 weeks mother–infant interaction was assessed using the Global Rating Scales of Mother–Infant Interaction. Three groups of infants were identified: (a) ‘‘withdrawn’’; (b) ‘‘extroverted’’; (c) ‘‘underaroused.’’ Differences between them were found regarding both infant and mother behaviors in the interaction and the overall quality of mother–infant interaction. The identification of behavioral and physiological profiles in infants is an important step in the study of developmental pathways.

Mother's stress, mood and emotional involvement with the infant: 3 months before and 3 months after childbirth

Adverse effects of maternal anxiety and depression are well documented, namely on the foetus/child behaviour and development, but not as much attention has been given to the mother's emotional involvement with the offspring. To study mother's prenatal and postpartum stress, mood and emotional involvement with the infant, the State-Trait Anxiety Inventory, the Edinburgh Postnatal Depression Scale and the Mother-to-Infant Bonding Scale were filled in and cortisol levels were measured, 3 months before and 3 months after childbirth, in a sample of 91 Portuguese women. From pregnancy to the postpartum period, mother's cortisol levels, anxiety and emotional involvement toward the child decrease. No significant change was observed regarding mother's depression. Mother's depression predicted a worse emotional involvement before childbirth, while mother's anxiety predicted a worse emotional involvement with the infant after childbirth. Additionally, pregnant women with a worse emotional involvement with the offspring are at risk of poorer emotional involvement with the infant and higher anxiety and depression at 3 months postpartum. It should be given more attention to mother's poor emotional involvement with the offspring during pregnancy, as it interferes with her emotional involvement with the infant and her psychological adjustment 3 months after childbirth.

Stress, cognitive appraisal, and psychological health: testing instruments for health professionals

The job of health professionals, including nurses, is considered inherently stressful (Lee & Wang, 2002; Rutledge et al., 2009), and thus it is important to improve and develop specific measures that are sensitive to the demands that health professionals face. This study analysed the psychometric properties of three instruments that focus on the professional experiences of nurses in aspects related to occupational stress, cognitive appraisal, and mental health issues. The evaluation protocol included the Stress Questionnaire for Health Professionals (SQHP; Gomes, 2014), the Cognitive Appraisal Scale (CAS; Gomes, Faria, & Gonçalves, 2013), and the General Health Questionnaire-12 (GHQ-12; Goldberg, 1972). Validity and reliability issues were considered with statistical analysis (i.e. confirmatory factor analysis, convergent validity, and composite reliability) that revealed adequate values for all of the instruments, namely, a six-factor structure for the SQHP, a five-factor structure for the CAS, and a two-factor structure for the GHQ-12. In conclusion, this study proposes three consistent instruments that may be useful for analysing nurses’ adaptation to work contexts.