Portfolio management of mixed-species forests

We propose to test the portfolio selection theory on the historical data of tree species’ productivities obtained from the French National Forest Inventory (IFN). We determine the optimal timber productivity-vulnerability arrangements out of the combinations of tree species and map the optimal compositions per administrative department in France. We also estimate the survivals of optimal portfolios using the species’ probabilities of presence. Our results show that greater weights in the optimal portfolios correspond to higher probabilities of presence

Affinity Purification Strategies for Proteomic Analysis of Transcription Factor Complexes

Affinity purification (AP) coupled to mass spectrometry (MS) has been successful in elucidating protein molecular networks of mammalian cells. These approaches have dramatically increased the knowledge of the interconnectivity present among proteins and highlighted biological functions within different protein complexes. Despite significant technical improvements reached in the past years, it is still challenging to identify the interaction networks and the subsequent associated functions of nuclear proteins such as transcription factors (TFs). A straightforward and robust methodology is therefore required to obtain unbiased and reproducible interaction data. Here we present a new approach for TF AP-MS, exemplified with the CCAAT/enhancer binding protein alpha (C/EBPalpha). Utilizing the advantages of a double tag and three different MS strategies, we conducted a total of six independent AP-MS strategies to analyze the protein–protein interactions of C/EBPalpha. The resultant data were combined to produce a cohesive C/EBPalpha interactome. Our study describes a new methodology that robustly identifies specific molecular complexes associated with transcription factors. Moreover, it emphasizes the existence of TFs as protein complexes essential for cellular biological functions and not as single, static entities