Physical Processes in Star Formation

© 2020 Springer-Verlag. The final publication is available at Springer via https://doi.org/10.1007/s11214-020-00693-8.Star formation is a complex multi-scale phenomenon that is of significant importance for astrophysics in general. Stars and star formation are key pillars in observational astronomy from local star forming regions in the Milky Way up to high-redshift galaxies. From a theoretical perspective, star formation and feedback processes (radiation, winds, and supernovae) play a pivotal role in advancing our understanding of the physical processes at work, both individually and of their interactions. In this review we will give an overview of the main processes that are important for the understanding of star formation. We start with an observationally motivated view on star formation from a global perspective and outline the general paradigm of the life-cycle of molecular clouds, in which star formation is the key process to close the cycle. After that we focus on the thermal and chemical aspects in star forming regions, discuss turbulence and magnetic fields as well as gravitational forces. Finally, we review the most important stellar feedback mechanisms.Peer reviewedFinal Accepted Versio

Scintillator ageing of the T2K near detectors from 2010 to 2021

The T2K experiment widely uses plastic scintillator as a target for neutrino interactions and an active medium for the measurement of charged particles produced in neutrino interactions at its near detector complex. Over 10 years of operation the measured light yield recorded by the scintillator based subsystems has been observed to degrade by 0.9–2.2% per year. Extrapolation of the degradation rate through to 2040 indicates the recorded light yield should remain above the lower threshold used by the current reconstruction algorithms for all subsystems. This will allow the near detectors to continue contributing to important physics measurements during the T2K-II and Hyper-Kamiokande eras. Additionally, work to disentangle the degradation of the plastic scintillator and wavelength shifting fibres shows that the reduction in light yield can be attributed to the ageing of the plastic scintillator. The long component of the attenuation length of the wavelength shifting fibres was observed to degrade by 1.3–5.4% per year, while the short component of the attenuation length did not show any conclusive degradation

Veiligheid in het luchtruim

ARTIKELEN: 1. P.A.M. Verrest en J.A.C. Bevers - Rechtshandhaving in het luchtruim 2. R.P. Bron en D. de Hoog - Civiele luchtvaart en terroristische incidenten, historische ontwikkelingen en toekomstige trends 3. W.C.J.M. van Dijk - Toegang tot een veilig luchtruim; 'security' op luchthavens 4. P.M.J. Mendes de Leon, m.m.v. M. Gurvits - De ontwikkeling van een trans-Atlantische luchtvaartrelatie in de periode 1992-2007 5. R.M. Schnitker - Het melden van voorvallen in de luchtvaart binnen een 'just culture' 6. B. Baksteen - Dilemma's van een gezagvoerder 7. F.G. von der Dunk - Ruimtepuin en ruimterecht 8. Internetsites. SAMENVATTING: Gezien de internationale context roept het streven naar veiligheid in het luchtruim tal van interessante vragen op op het terrein van wet- en regelgeving, internationale verdragen, rechtsmacht, rechtshandhaving en -vervolging. Er bestaat een grote variëteit aan overtredingen en misdrijven die kunnen worden begaan, zowel delicten aan boord van vliegtuigen als tegen en met het gebruik van vliegtuigen. Vanuit het perspectief van de reguliere rechtshandhaving zijn de omstandigheden waaronder luchttransport plaatsvindt uniek: in een vrijwel geïsoleerd en kwetsbaar voertuig worden internationale grenzen met grote snelheden gepasseerd

Sex and Cardiovascular Function in Relation to Vascular Brain Injury in Patients with Cognitive Complaints

Background: Emerging evidence shows sex differences in manifestations of vascular brain injury in memory clinic patients. We hypothesize that this is explained by sex differences in cardiovascular function.Objective: To assess the relation between sex and manifestations of vascular brain injury in patients with cognitive complaints, in interaction with cardiovascular function.Methods: 160 outpatient clinic patients (68.8 +/- 8.5 years, 38% female) with cognitive complaints and vascular brain injury from the Heart-Brain Connection study underwent a standardized work-up, including heart-brain MRI. We calculated sex differences in vascular brain injury (lacunar infarcts, non-lacunar infarcts, white matter hyperintensities [WMHs], and microbleeds) and cardiovascular function (arterial stiffness, cardiac index, left ventricular [LV] mass index, LV mass-to-volume ratio and cerebral blood flow). In separate regression models, we analyzed the interaction effect between sex and cardiovascular function markers on manifestations of vascular brain injury with interaction terms (sex*cardiovascular function marker).Results: Males had more infarcts, whereas females tended to have larger WMH-volumes. Males had higher LV mass indexes and LV mass-to-volume ratios and lower CBF values compared to females. Yet, we found no interaction effect between sex and individual cardiovascular function markers in relation to the different manifestations of vascular brain injury (p-values interaction terms > 0.05).Conclusion: Manifestations of vascular brain injury in patients with cognitive complaints differed by sex. There was no interaction between sex and cardiovascular function, warranting further studies to explain the observed sex differences in injury patterns.Neuro Imaging Researc