La présente étude visait à documenter l’implantation de l’Accompagnement-citoyen personnalisé d’intégration communautaire (APIC), lors duquel des bénévoles soutiennent la participation sociale d’aînés, dans des organismes communautaires en identifiant les facteurs favorables et défavorables ainsi que ses conditions essentielles. Soutenu par un devis qualitatif descriptif de type recherche clinique, une rencontre et six entretiens semi-dirigés ont été réalisés afin de documenter cette implantation dans six organismes communautaires œuvrant en milieu urbain au Québec (Canada). Selon les six coordonnatrices de l’APIC, les cinq directeurs généraux et l’agente de recherche, le principal facteur favorable est la conviction des responsables de l’implantation en la valeur ajoutée de l’intervention, incluant sa concordance avec la mission et les valeurs des organismes et les besoins de la population qu’ils desservent. Les facteurs défavorables sont principalement la répartition aléatoire et le temps accordé pour l’implantation. Ces résultats permettront de mieux guider l’implantation de l’APIC à plus grande échelle.

Limbic white matter pathways link emotion, cognition, and behavior and are potentially malleable to the influences of traumatic events throughout development. However, the impact of interactions between childhood and later life trauma on limbic white matter pathways has yet to be examined. Here, we examined whether childhood maltreatment moderated the effect of combat exposure on diffusion tensor imaging measures within a sample of military veterans (N = 28). We examined five limbic tracts of interest: two components of the cingulum (cingulum, cingulate gyrus, and cingulum hippocampus [CGH]), the uncinate fasciculus, the fornix/stria terminalis, and the anterior limb of the internal capsule. Using effect sizes, clinically meaningful moderator effects were found only within the CGH. Greater combat exposure was associated with decreased CGH fractional anisotropy (overall structural integrity) and increased CGH radial diffusivity (perpendicular water diffusivity) among individuals with more severe childhood maltreatment. Our findings provide preliminary evidence of the moderating effect of childhood maltreatment on the relationship between combat exposure and CGH structural integrity. These differences in CGH structural integrity could have maladaptive implications for emotion and memory, as well as provide a potential mechanism by which childhood maltreatment induces vulnerability to later life trauma exposure.

Childhood maltreatment can disturb brain development and subsequently lead to adverse socioemotional and mental health problems across the life span. The long-term association between childhood maltreatment and resting–wake brain activity during adulthood is unknown and was examined in the current study. Forty-one medically stable and medication-free military veterans (M = 29.31 ± 6.01 years, 78% male) completed a battery of clinical assessments and had [18F]-fluorodeoxyglucose positron emission tomography neuroimaging scans during quiet wakefulness. After statistically adjusting for later-life trauma and mental health problems, childhood maltreatment was negatively associated with brain activity within a priori defined regions that included the left orbital frontal cortex and left hippocampus. Childhood maltreatment was significantly associated with increased and decreased brain activity within six additional whole-brain clusters that included the frontal, parietal–temporal, cerebellar, limbic, and midbrain regions. Childhood maltreatment is associated with altered neural activity in adulthood within regions that are involved in executive functioning and cognitive control, socioemotional processes, autonomic functions, and sleep/wake regulation. This study provides support for taking a life span developmental approach to understanding the effects of early-life maltreatment on later-life neurobiology, socioemotional functioning, and mental health.

AlGaN/GaN HEMT's were grown on 6″ Si <111> substrates and passivated using IMEC's in-situ SiN technique. The epitaxial growth was optimized to minimize RF losses due to the substrate-nitride interface while at the same time maintaining high buffer resistivity and low trap density.

To assess RF losses of the epitaxial layer structure, coplanar waveguides were defined on places of the wafer where the top in-situ SiN and AlGaN has been etched away. The attenuation of the RF signals on the coplanar waveguides remained below 0.3dB/mm for frequencies up to 6GHz.

The processing of HEMT's included mesa etching, the formation of TiAlMoAu ohmic contacts, 500nm long gates with source-connected field plates and an airbridge process. The gate fingers are 250µm wide, yielding a total gate periphery of 1.5mm for 6-finger devices and 5mm for the 20-finger version.

The devices' RF power performance was characterised on-wafer. To avoid damage to the RF-probes, active load-pull measurements were performed in pulsed mode with a 100µs period under 10% and 30% duty cycle respectively. As there was no difference between the performance using different duty cycles, we conclude that the channel temperature reaches steady-state in less than 10µs.

The 6-finger devices were operated in deep class AB operation mode but showed clear self-biasing effects. The bias voltage was changed from 30V to 60V in 10V increments. Under 60V bias, the devices provide an output power density of 7.9W/mm at 2GHZ with a PAE of 46% and 6.3W/mm at 4GHz with a PAE of 41%. The output power scales linearly with the bias voltage ranging from 30V to 60V, showing that there is no drain lag in the devices. We attribute this to the efficient surface passivation with the in-situ Si3N4 as well as to high crystal quality and hence the low trap density of the buffer layers. At 2GHz, the linear and saturated power gain are 22dB and 16.4dB respectively. An interesting observation is that the maximum gate current, even at power density levels of 7.9W/mm, remains below 50µA/mm which should prove beneficial for reliability.

The larger 20-finger devices of 5mm total gate periphery reach a maximum absolute output power of 20W at a bias of 40V which represents the limit of our on-wafer measurement system.

These results prove that the use of large area Si substrates is the only viable route forward for AlGaN/GaN HEMT's.

A duster of four patients with hepatitis C virus (HCV) infection was identified in a surgery clinic. Molecular characterization revealed close homology between viruses. This cluster was related to unsafe injection practices through multidose vials and reused materials. Among 796 patients potentially exposed to and screened for HCV, no other cluster was identified.

That PTSD nightmares are highly realistic threat simulations triggered by trauma is difficult to reconcile with the disturbed, sometimes debilitating sleep and waking functioning of PTSD sufferers. A theory that accounts for fundamental forms of imagery other than threat scenarios could explain the selection of many more adaptive human functions – some still pertinent to survival today. For example, interactive characters, a virtually ubiquitous form of dream imagery, could be simulations of attachment relationships that aid species survival in many different ways.

[Revonsuo]

The evolutionary theory of threat simulation during dreaming indicates that themes appropriate to ancestral survival concerns (threats) should be disproportionately represented in dreams. Our studies of typical dream themes in students and sleep-disordered patients indicate that threatening dreams involving chase and pursuit are indeed among the three most prevalent themes, thus supporting Revonsuo's theory. However, many of the most prevalent themes are of positive, not negative, events (e.g., sex, flying) and of current, not ancestral, threat scenarios (e.g., schoolwork). Moreover, many clearly ancestral themes (e.g., snakes, earthquakes) are not prevalent at all in dreams. Thus, these findings challenge the specificity of the threat simulation theory.

[Revonsuo]