Suchergebnisse

Research investigating the effects of trauma exposure on brain structure and function in adults has mainly focused on post-traumatic stress disorder (PTSD), whereas trauma-exposed individuals without a clinical diagnoses often serve as controls. However, this assumes a dichotomy between clinical and subclinical populations that may not be supported at the neural level. In the current study we investigate whether the effects of repeated or long-term stress exposure on brain structure in a subclinical sample are similar to previous PTSD neuroimaging findings. We assessed 27 combat trauma-exposed individuals by means of whole-brain voxel-based morphometry on 3 T magnetic resonance imaging scans and identified a negative association between duration of military deployment and gray matter volumes in ventromedial prefrontal cortex (vmPFC) and dorsal anterior cingulate cortex (ACC). We also found a negative relationship between deployment-related gray matter volumes and psychological symptoms, but not between military deployment and psychological symptoms. To our knowledge, this is the first whole-brain analysis showing that longer military deployment is associated with smaller regional brain volumes in combat-exposed individuals without PTSD. Notably, the observed gray matter associations resemble those previously identified in PTSD populations, and concern regions involved in emotional regulation and fear extinction. These findings question the current dichotomy between clinical and subclinical populations in PTSD neuroimaging research. Instead, neural correlates of both stress exposure and PTSD symptomatology may be more meaningfully investigated at a continuous level.

The planned High Luminosity Large Hadron Collider is being designed to maximise the physics potential of the LHC with 10 years of operation at instantaneous luminosities of 7.5×10 34 cm ¿2 s ¿1 . A consequence of this increased luminosity is the expected radiation damage requiring the tracking detectors to withstand hadron fluence to over 1×10 15 1 MeV neutron equivalent per cm 2 in the ATLAS Strips system. Fast readout electronics, deploying 130 nm CMOS front-end electronics are glued on top of a silicon sensor to make a module. The radiation hard n-in-p micro-strip sensors used have been developed by the ATLAS ITk Strip Sensor collaboration and produced by Hamamatsu Photonics. A series of tests were performed at the DESY-II test beam facility to investigate the detailed performance of a strip module with both 2.5 cm and 5 cm length strips before irradiation. The DURANTA telescope was used to obtain a pointing resolution of 2 ¿m, with an additional pixel layer installed to improve timing resolution to ~25 ns. Results show that prior to irradiation a wide range of thresholds (0.5¿2.0 fC) meet the requirements of a noise occupancy less than 1×10 ¿3 and a hit efficiency greater than 99%. © 2018 ; The research was supported and financed in part by Canada Foundation for Innovation, the National Science and Engineering Research Council (NSERC) of Canada under the Research and Technology Instrumentation (RTI) grant SAPEQ-2016-00015; the National Key Program for S&T Research and Development (Grant No. 2016YFA0400101) of China and CAS-Helmholtz Joint Research Group; theMinistry of Education, Youth and Sports of the Czech Repub87lic coming from the projectLM2015058 - Research infrastructure for experiments at CERN; the DST/NRF in South 88 Africa; the Spanish Ministry of Economy and Competitiveness through the Particle Physics National Program, ref. 89 FPA2015-65652-C4-4-R (MINECO/FEDER, UE), and co-financed with FEDER funds; the UK's Science and Tech90nology Facilities Council; USA Department of Energy, Grant DE-SC0010107; and the European Union's Horizon 2020 Research and Innovation programme under Grant Agreement no. 654168. The measurements leading to these results have been performed at the Test Beam Facility at DESY Hamburg (Germany), a member of the Helmholtz Association (HGF).