Blunted autonomic reactivity to mental stress in depression quantified by nonlinear cardiorespiratory coupling indices

In this study, differences in autonomic reactivity to mental stress between Major Depressive Disorder (MDD) patients and healthy control (HC) subjects are assessed by nonlinear cardiorespiratory coupling indices derived from the Real Wavelet Biphase. The degree and strength of Quadratic Phase Coupling (QPC) between interacting oscillations of Heart Rate Variability (HRV) and respiration are quantified before, during and after the execution of acognitive task. Results show that the QPC strength and QPC degree between the respiration and the respiratory sinus arrhythmia component of HRV were lower in HC compared to MDD during stress, suggesting that the parasympathetic branch was less inhibited in MDD patients. During recovery, only in HC group, this degree of QPC increased, while the respiratory rate was reduced, compared to the basal stage. The degree of QPC between the respiration and components of HRV in the low frequency band ([0.04, 0.15] Hz) increased in HC during stress, compared to the basal stage, while remained unchanged in MDD patients. These results imply that depression is associated with blunted autonomic reactivity to mental stres

Combining MRI and clinical data to detect high relapse risk after the first episode of psychosis

Detecting patients at high relapse risk after the first episode of psychosis (HRR-FEP) could help the clinician adjust the preventive treatment. To develop a tool to detect patients at HRR using their baseline clinical and structural MRI, we followed 227 patients with FEP for 18–24 months and applied MRIPredict. We previously optimized the MRI-based machine-learning parameters (combining unmodulated and modulated gray and white matter and using voxel-based ensemble) in two independent datasets. Patients estimated to be at HRR-FEP showed a substantially increased risk of relapse (hazard ratio = 4.58, P < 0.05). Accuracy was poorer when we only used clinical or MRI data. We thus show the potential of combining clinical and MRI data to detect which individuals are more likely to relapse, who may benefit from increased frequency of visits, and which are unlikely, who may be currently receiving unnecessary prophylactic treatments. We also provide an updated version of the MRIPredict software

Regulation of carotenoid biosynthesis in photosynthetic organs

A substantial proportion of the dazzling diversity of colors displayed by living organisms throughout the tree of life is determined by the presence of carotenoids, which most often provide distinctive yellow, orange and red hues. These metabolites play fundamental roles in nature that extend far beyond their importance as pigments. In photosynthetic lineages, carotenoids are essential to sustain life, since they have been exploited to maximize light harvesting and protect the photosynthetic machinery from photooxidative stress. Consequently, photosynthetic organisms have evolved several mechanisms that adjust the carotenoid metabolism to efficiently cope with constantly fluctuating light environments. This chapter will focus on the current knowledge concerning the regulation of the carotenoid biosynthetic pathway in leaves, which are the primary photosynthetic organs of most land plants.My research is mainly funded by the EC Marie Curie research project CarotenActors (FP7-PEOPLE-2011-IIF 300862) and the MINECO Postdoctoral Grant (FPDI-2013-018882). I also acknowledge the support from grants from MINECO (BIO2011-23680) and CYTED (Ibercarot-112RT0445).Peer reviewe