Guest lectures and seminars - Page 58

Abstract: Upon burst, air bubbles release droplets that transfer biological and chemical materials from water bodies to the atmosphere. This mechanism is one of the main sources of cloud condensation nuclei and participates to airborne contamination when the bulk water contains pathogens. Predicting the size and composition of droplets emitted by bubbles requires a fundamental understanding of their dynamic at the surface, yet a consistent physical picture is lacking. Relying on experimental data from bubbles generated in various environments and using scaling analysis, I will show that surface tension gradients control the drainage of bubbles. I will also explain how local perturbations of surface tension can explain their seemingly stochastic burst mechanism. Consequences for application purposes will be mentioned throughout the presentation: I will notably take the examples of bubbles in saltwater and in water contaminated with bacteria.

This talk is part of the Mechanics Lunch Seminar series. That means 20min talks plus discussion in an informal setting.

Zoom: To obtain the Zoom meeting details please contact Timo Koch (timokoch at math.uio.no).

Now it's time for the traditional PhD/postdoc-gathering for Stochastics and Risk which will take place in Abels Utsikt and online on October 28th, 09.30 - 16.30. All PhD students and postdocs have the opportunity to give a 15-minute talk on their research. In addition, Jocelyne Bion-Nadal (École Polytechnique) will give an introductory talk and Kristina Rognlien Dahl (UiO) will introduce the SCROLLER project. As a member of the section, you can attend either in person or online. Welcome!

Benjamin Kedem (Department of Mathematics, University of Maryland, USA) will give a talk on October 27th at 14:15 in Zoom - the link will be sent by mail one day in advance).

Registration Link: https://nettskjema.no/a/167852 

Abstract: Frailty is a multi-system dysregulation leading to a loss of physiological reserve known to predict dementia. However, its link with neurodegenerative alterations of the central nervous system (CNS) is not well understood at present. We investigated the association between the biomechanical response of the CNS and frailty in older adults suspected of normal pressure hydrocephalus (NPH) presenting markers of multiple comorbid neurodegenerative pathologies, including pathologies of Alzheimer’s Disease. The biomechanical response of the CNS was characterized from phase contrast magnetic resonance imaging and intracranial pressure monitoring during a lumbar infusion test. Frailty was assessed with an index of health deficit accumulation. We found a significant association between the CNS biomechanical response and frailty, with an effect size comparable to that between frailty and age, the latter being the strongest known risk factor of frailty. The CNS biomechanical characterization may help to understand how frailty is related to neurodegeneration and detect the shift from normal to pathological brain ageing.

This talk is part of the Mechanics Lunch Seminar series. That means 20min talks plus discussion in an informal setting.