PhD position at the beam line BL11-NCD

This PhD studentship is funded by the Consejo Seguridad Nuclear (CSN), Spain.  
          
RESEARCH PROGRAM:

Skeletal muscle activation and regulation – a study of radiation damage

The relatively recent access to third generation synchrotron radiation (SR) sources, such as the
Alba light facility in Cerdanyola del  Vallés (Barcelona), allows to follow with high temporal
and angular resolutions the molecular events associated with the generation of force and motion
in live muscle tissues. Particularly, the specifications of Alba and its associated
instrumentations open the way to provide unique insights into the structure and function of
skeletal muscle.

Small angle diffraction of x-rays (SAXD) is the most powerful experimental tool in
investigations aiming to probe the internal molecular architecture of skeletal muscles.
Specifically, the structural organisation in muscle can be determined because of the highly
ordered macromolecular arrangement of the contractile proteins, myosin and actin, in the
sarcomere, as well as the regulator proteins found in the muscle cell. The possibility to
collect diffraction diagrams with high angular resolution with a sub-millisecond time resolution
at Alba comes from the fact that the BL11-NCD is connected to a photon source, an in-vacuum
undulator, that delivers to the sample a monochromatic beam of high brightness and a very low
emittance. To be noted is that time-resolved muscle fibre diffraction research where the
structural and functional properties are probed is the only experimental method available that
allows for information at the molecular level in otherwise totally undisturbed live tissues to
be collected.

The generation of force and motion in muscle tissues involves the interaction between the actin
and myosin molecules in the thin and thick filaments, respectively. However, the activation and
regulation of this process involves subtle motions of the troponin and tropomyosin molecules
(that are complexed with the thin filaments). The time constants associated with
activation/regulation are even faster than those associated with force production, whilst the
strength of the diffraction features due to troponin and tropomyosin is weak. This is the reason
why these events have not been the object of systematic studies in the past. Given the
characteristics of the beam line this limitations will be significantly reduced, if not overcome
and, therefore, it is proposed to initiate a research program focusing on activation and
regulation of skeletal muscle using live, intact and fully functional muscle tissues.  Knowing
the properties in the intact undisturbed muscle tissue will allow identification of mechanisms
that are responsible for radiation damage of the biological cell, the skeletal muscle.
    
Qualifications:   
To be accepted as a PhD student, credits corresponding to completion of full-time studies at the
undergraduate level including at least three years of full time studies in physics and to lesser
degree in mathematics. Knowledge in the use of computers and operating systems will be considered
favourably.

Applicants are to provide a curriculum vitae (CV), a letter of motivation and the contact details
for two referees.