The Photon Day May 6th 2021


To promote photon sciences at UU, the Centre of Photon Science invites you to the Photon Day, May 6! There will be three interesting talks, including one by the winner of the 2020 "Uppsala Photon Science Award”.

The Photon Day will only be given over zoom


13.15 Welcome and introduction

13.20 Oxana Klementeva (LU): Combining microspectroscopy and neurobiology  for understanding Alzheimer\s disease

Alzheimer's disease affects the lives of millions of people worldwide, already costing about 1 % of the global economy. Alzheimer's disease is characterized by the formation of protein amyloid aggregates, so-called amyloid oligomers. These oligomers are characterized by specific β-sheet structures and are thought to be neurotoxic. However, the secondary structure of amyloid oligomers is polymorphic and the structure that contributes most to the neurotoxicity is unknown. This lack of knowledge exists mainly because it is incredibly challenging to characterize the secondary structure of amyloid proteins directly in cells. To investigate molecular changes in proteins directly in cells, we used synchrotron-based infrered microspectroscopy, a label-free and non-destructive technique available for in situ molecular imaging. Specifically, we evaluated the formation of β-sheet structures in cells that simultaneously express human amyloid proteins, models of p amyloid aggregation related to Alzheimer's disease.·

13.55 Martin Qvarnström (UU) winner of the 2020 "Uppsala Photon Science Award”: Who ate whom? Paleoecology revealed through synchrotron microtomography of fossil droppings.

How can we know that one of the first dinosaurs was pecking insects on the ground, like a bird? That a big dinosaur crushed bones like a hyena 210 million years ago? And that some pterosaurs (flying reptiles) were feeding like modern day flamingos in the Jurassic? By analysing their droppings! Fossil droppings (coprolites) are surprisingly common and are being increasingly recognized as a valuable source of paleobiological information. However, most information is found in their contents, which are difficult to study because of the surrounding mineralised matrix. I have used propagation phase-contrast synchrotron microtomography to reconstruct the contents of coprolites and, in my talk, I will not only show you the inferred feeding behaviours mentioned above, but also what happened with trophic food webs when dinosaurs were gradually rising to ecological dominance in the Late Triassic and Early Jurassic.

14.25 Oleg Shpyrko (UCSD): Search for Speckle-Encoded "Hidden" Fluctuations: A Bright Future of X-ray Photon Correlation Spectroscopy.

Speckle image

Coherent X-ray Scattering allows scientists to peer beyond "ensemble average" and study local structure and dynamics of complex materials, often characterized by domains, heterogeneities and other forms of nanoscale disorder. In recent years, X-ray photon correlation spectroscopy (XPCS) has emerged as one of the key probes of nanoscale fluctuations, applicable to a wide range of complex materials systems. I will review basic principles of XPCS as well as some of its recent applications in condensed matter physics.


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Last modified: 2021-09-23