The dynamics of the tropics fascinate me and I find animal behavior particularly interesting. The teeming biodiversity of tropical forests and related ecosystems contribute to a complex, multi-tiered system that prompt numerous research questions.  I am interested in species interactions, in how and why species can co-exist, compete, communicate, develop mutualisms and evolve with time to form viable communities.  At the species level I am drawn to the intricacies of mating systems and how sexual selection plays a major role in natural selection.  How and why mates are selected is at the heart of mating systems but remains largely mysterious and the use of effective communication is finally being recognized as key to successful courtship and ultimate partnership.  My Neotropical research illustrates the rich natural resources available to us but there is a paucity of knowledge thus far and it is this paucity that intrigues me and I am thus dedicated to conservation efforts aimed toward its protection.

In bacteria,small noncoding RNAs (sRNAs) are found to coordinate complex network of gene regulation in response to environmental changes. The sRNAs also play a role in determining virulent gene expression. Pseudomonas aeruginosa is a bacterium which commonly resides in soil and water, but it can cause severe infection in patients with compromised immune systems. Pseudomonas aeruginosa is capable of forming biofilm in which during this phase, it is highly resistant to various antibiotics. In  my study, the sRNAs (and the specific binding targets) that are expressed exclusively during biofilm formation phase will be identified. The functions of the sRNAs will then be revealed. The sRNAs that are associated with virulent gene expression will help to understand the mechanisms of pathogenesis and act as possible targets for generation of new antimicrobial drugs. As Pseudomonas is considered a model organism for the study of antibiotic-resistant bacteria, my study hopes to be applicable to other pathogenic bacteria as well.

During a long period of time, humans have adapt themselves to a picking-hunting way of life, characterized by a high physical activity and a restricted amount of calories. However, these last decades, changes in human lifestyle, including sedentarity and hyper caloric diet are leading to obesity, metabolic syndrome and type 2 diabetes (T2D). Type 2 diabetes (formerly called non-insulin-dependent or adult-onset) results from the muscular ineffective action of insulin.

G-protein coupled receptors (GPCRs) form the largest class of proteins found in human cell membranes. They are involved in important biological functions (neurotransmission, hormonal regulation, inflammatory response, sensory reception...) and therefore are of great pharmaceutical interest. When a signalling molecule coming from the extracellular environment binds to a GPCR, it induces changes in the structure of the receptor. These modifications provoke the activation of an intracellular protein associated (or coupled) to the receptor, called G-protein. The activated G-protein triggers a cascade of intracellular biochemical reactions, leading to a biological response from the cell to the signal received. One of our goals is to characterize the receptor structural changes that allow the G-protein coupling and activation. As the receptors are embedded in the cell membrane, we want in particular to understand how this membrane environment modulates GPCRs activation mechanism

The human body is made up of several billions of cells. Without communication between cells, the organism would not be able to function. Intercellular communication takes place at the membrane which surrounds each cell. This protective envelope is mainly composed of a lipid bilayer in which are embedded several types of proteins that ensure interactions with the extracellular environment. Among these proteins, the so called receptors are crucial for the communication process: their role is to detect the extracellular signals (specific molecule, electrical impulse…) and transmit the "message" inside the cell. The G-protein coupled receptors (GPCRs) are involved in essential biological processes (neurotransmission, hormonal regulation, inflammatory response, sensory reception...) and are targeted by 50% of drugs. Upon detection of a stimulus, a receptor is activated: it undergoes changes in its form, which trigger the signal transmission. Studying these structural modifications allows us to better understand the functioning of a receptor at the molecular level, useful notably for drug design. The aim of my research work is to get insight into the structural changes responsible for GPCRs activation and to study how the different lipids of the membrane can influence them.

I am studying the role of legume trees in the nitrogen cycle of tropical dry forests of Costa Rica. Legumes belong to the Fabaceae plant family and differ from other plant species in that because they can form a symbiotic relationship with soil bacteria which fix nitrogen from the atmosphere and convert it to a form that the plants can use. I want to understand to what extent legumes with their nutrient rich lifestyle influence the soil environment around them on a tree basis and at the level of a plant community. It is crucial to understand how the dry forest ecosystems work: they are the most endangered tropical biome because their long dry season has made them favourable has exposed them to for human settlement and for to agricultural uses. Furthermore it is still difficult to establish how humans are altering the global nitrogen cycle through fossil fuel combustion, fertilizer production and the cultivation of N-fixing crops or what the consequences are for ecosystem functions in the future. In order to understand how much to what extend this process has been artificially perturbed, I consider necessary to have robust knowledge of the nitrogen cycle in natural ecosystems to serve as a benchmark for comparison.