Bacteria are highly complex and diverse organisms that have adapted to survive in ecological niches ranging from the most extreme to the most heterogeneous environments. Actinobacteria, with their... Show moreBacteria are highly complex and diverse organisms that have adapted to survive in ecological niches ranging from the most extreme to the most heterogeneous environments. Actinobacteria, with their beautiful morphologies and complex multicellular life cycle, are a striking example. These filamentous bacteria produce many enzymes and natural products, including two-thirds of all known antibiotics, which makes them highly relevant for medical, biotechnological and industrial applications. In Streptomyces, complex and intertwining regulatory networks, consisting of pathway-specific and global regulators, control development and antibiotic production in response to environmental stimuli and stresses. This thesis explores how the model organism Streptomyces coelicolor senses environmental signals, related to oxygen stress and the availability of aminosugars, and how the bacterium translates these into appropriate responses. Show less
The human body is inherently designed to be able to adapt to challenging situations. However, some experiences are so severe that they can lead to substantial and longerlasting disturbances in an... Show moreThe human body is inherently designed to be able to adapt to challenging situations. However, some experiences are so severe that they can lead to substantial and longerlasting disturbances in an individuals’ behavioral, psychological and physiological functioning. Importantly, there is a degree of inter-individual variation, as not all individuals show similar reactions to severe stress. Neuroimaging techniques can help to unravel the brain characteristics related to vulnerability and resilience to severe stress. In the research for this dissertation several neuroimaging modalities were used to further explore the brain characteristics related to (dys)function after exposure to severe stress and after exposure to hypercortisolism, such as voxel-based morphometry and diffusion tensor imaging to study the structure of gray and white matter in the brain, and resting-state fMRI to study functional connectivity patterns. We studied brain characteristics in several groups consisting of: patients in long-term remission of Cushing’s disease, and individuals with a history of childhood emotional maltreatment to examine the effects of hypercortisolism and severe stress on the brain. In addition, we studied a group of police officers and a group of individuals with a history of childhood maltreatment to investigate the brain characteristics related to resilience to stress. Show less
Previous research has provided evidence for the link between psychological processes and psychophysiological health outcomes. Psychological interventions, such as face-to-face or online cognitive... Show morePrevious research has provided evidence for the link between psychological processes and psychophysiological health outcomes. Psychological interventions, such as face-to-face or online cognitive behavioral therapy (CBT) and serious games aimed at improving health, have shown promising results in promoting health outcomes. Few studies so far, however, have examined whether Internet-based CBT combined with serious gaming elements is effective in modulating health outcomes. Moreover, studies often did not incorporate psychophysiological or immunological challenges in order to gain insight into physiological responses to real-life challenges after psychological interventions. The overall aim of this study is to investigate the effects of a psychological intervention on self-reported and physiological health outcomes in response to immune and psychophysiological challenges. Show less
