Science

INTERNSHIP Ref. : LSS_03

The Laue Langevin Institute, located in Grenoble, is Europe's neutron source. It provides its user community, consisting of European scientists from all disciplines, with neutron beams and appropriate instruments to solve questions about the structure and dynamics of materials at scales ranging from tenths of nanometers to several hundred nanometers. Among the techniques it offers, BioSANS allows for the analysis of the structure of biological molecules.

To facilitate the planning and analysis of BioSANS data, a scientific software called Pepsi is currently available via command-line and through an older web interface, accessible at pepsi.app.ill.fr.

Activities of the trainee

We are looking for a motivated student to:

1. Develop a modern web interface to control the command-line application.
2. Provide an interactive 3D and 2D interface.
3. Ensure security aspects.
4. Provide continuous integration using GitHub/GitLab.
5. Design a desktop client offering a comparable interface, compatible with Linux.

The goal is to make the application more accessible and user-friendly, both via a browser and within our analysis infrastructure.

The candidate should have the necessary skills in:

• Programming and
• Web interface development.

Additionally, they should demonstrate:

• Scientific openness to understand the purpose of their work.
• Strong autonomy.
• Good organizational and communication skills to interact with the multiple stakeholders involved in this project.

During the 6-month internship, the candidate will gain enriching experience in a culturally and scientifically diverse environment, along with a stipend ranging from 750 to 900 euros per month (depending on education level).

The internship will take place at ILL, with possible visits to the LJK UGA laboratory. The project will be supervised by:

• Anne Martel, ILL Instrument Scientist.
• Erwan Le Gall, ILL, IT Team Leader.
• Sergei Grudinin, LJK UGA, Developer of the Pepsi model, https://grulab.imag.fr

Level required

5 year university studies in Computing

Language skill

As an international research centre, we are particularly keen to ensure that we also attract applicants from outside France. You must be able to communicate in English or in French.

Notes

This post is an internship with a maximum duration of 5months

Please send your application directly to the supervisor:

Anne Martel,

email : martel@ill.fr

INTERNSHIP Ref. : THEORY_01

Fluid lipid bilayers are the building blocks of biological membranes. The local dynamics of lipid molecules in membrane bilayers have recently been described using the dynamical Matryoshka model (dMm), which employs a nested hierarchical convolution of motional processes derived from quasi-elastic neutron scattering (QENS) experiments. However, the current dMm framework is no longer applicable to more complex lipid arrangements forming non-bilayer phases. Such lipid phases are observed in functional thylakoid membranes and the inner mitochondrial membranes that display highly dynamic lipid polymorphisms: the lamellar (bilayer) phase, the non-bilayer lipid phases such as inverted hexagonal (HII) or isotropic phases (I) [1, 2].

The main objectives of the internship are to extend the current Matryoshka model to describe local dynamics of lipid molecules in non-bilayer lipid phases, namely, in inverted hexagonal (HII) or isotropic phases (I).

Activities of the trainee

1. Inventory review of local motions of lipid molecules in non-bilayer lipid phases;
2. Theoretical calculations of the incoherent neutron structure function (ISF) for non-bilayer lipid phases;
3. Use the derived ISF to experimental QENS data on DOPC:DOPE mixtures, mimicking membrane polymorphism.

Level required

4 year university studies in Physics & Biophysics

Language skill

As an international research centre, we are particularly keen to ensure that we also attract applicants from outside France. You must be able to communicate in English or in French.

Notes

This post is an internship with a maximum duration of 3 à 5months

Please send your application directly to the supervisor:

Dominique Bicout,

email : bicout@ill.fr

Model lipid bilayers, reconstituted by using bacterial polar lipid extracts, are reliable systems to investigate the physical properties of bacterial membranes, and can be used, for example, to aid the design of new antibiotics. Such natural polar mixtures in their labeled form are essential tools for neutron scattering studies of biological membranes; however, deuteration is known to perturb fatty acid metabolism and alter lipid biosynthetic pathways. Previous fatty acid analyses in Escherichia coli and Pichia pastoris have revealed significant changes within various lipid series under deuterated growth conditions, suggesting that deuterium incorporation directly impacts genes involved in lipid metabolism. Building on these observations, this project aims to investigate how deuteration, applied under different growth temperatures and across the growth curve of the gram positive bacteria 'Bacillus subtilis' and the gram negative bacteria 'Escherichia coli' affects changes in the global acyl chain compositions. The project would aim to optimize matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometric methods for rapid and direct analysis of a wide range of molecular compositions within all the purified phospholipid mixtures. The study of such complex lipid mixtures is important to recreate highly biologically relevant bacterial membrane models for studies aimed at understanding the biological function of bacterial membranes.

Activities of the trainee

Growing bacterial cell cultures

Lipid extraction and purification ny Solid phase extraction and HPLC

Optimizing MALDI-TOF methods for determining lipid compositions

Level required

+4, +5 year university studies in Lipid Biochemistry

Language skill

As an international research centre, we are particularly keen to ensure that we also attract applicants from outside France. You must be able to communicate in English or in French.

Notes

This post is an internship with a maximum duration of 5months

Please send your application directly to the supervisor:

Krishna BATCHU,

email : batchu@ill.fr

Neutron dark-field imaging (DFI) provides sensitivity to microstructural features below the spatial resolution of conventional transmission-contras radiography, through contrast arising from small-angle scattering from of incoming radiation from these features. Most established neutron DFI approaches rely on grating interferometry, which impose time constraints and limit potential in-situ studies of material processes.

Recent developments in neutron imaging have shown that dark-field contrast can also be obtained using structured absorption masks, by analysing local visibility loss in modulated beamlets, similarly to Hartmann mask approach used in X-ray imaging. This approach is promising for cold neutron imaging instruments operating with widespectrum beam, such as the PorTo instrument at ILL.

Activities of the trainee

The aim of this MSc thesis project is to design, fabricate, and experimentally validate Gd-based random absorption mask for dark-field neutron imaging, and to demonstrate their sensitivity to Objectives:

- Design and optimisation of random absorption masks

- Implementation of random-mask dark-field neutron imaging protocol and data processing

- Evaluate the mask in a neutron imaging setup

-Validation on additively manufactured micro-porous high Z metallic materials

The ideal candidate will have a background in experimental physics, materials science, or engineering, with strong curiosity for imaging and image analysis. Familiarity with image processing and data analysis (e.g. Python) is a benefit. An interest in experimental work, instrumentation, and materials characterisation is highly encouraged. Prior exposure to additive manufacturing or porous materials is an advantage but not mandatory.

Level required

+4, +5 year university studies in Physics, Applied Physics, Engineering, Material Science

Language skill

As an international research centre, we are particularly keen to ensure that we also attract applicants from outside France. You must be able to communicate in English or in French.

Notes

This post is an internship with a maximum duration of 6months

Please send your application directly to the supervisor:

Bratislav LUKIC,

email : lukicb@ill.fr