A novel brain partition highlights the modular skeleton shared by structure and function

Elucidating the intricate relationship between brain structure and function, both in healthy and pathological conditions, is a key challenge for modern neuroscience. Recent progress in neuroimaging has helped advance our understanding of this important issue, with diffusion images providing information about structural connectivity (SC) and functional magnetic resonance imaging shedding light on resting state functional connectivity (rsFC). Here, we adopt a systems approach, relying on modular hierarchical clustering, to study together SC and rsFC datasets gathered independently from healthy human subjects. Our novel approach allows us to find a common skeleton shared by structure and function from which a new, optimal, brain partition can be extracted. We describe the emerging common structure-function modules (SFMs) in detail and compare them with commonly employed anatomical or functional parcellations. Our results underline the strong correspondence between brain structure and resting-state dynamics as well as the emerging coherent organization of the human brain.

On the temperature dependence of the rate coefficient of formation of C2+ from C + CH+

[EN] We carry out quasi-classical trajectory caculations for theC + CH+ → C2+ + H reaction on an ad hoc computed high-level ab initio potential energy surface. Thermal rate coefficients at the temperatures of relevance in cold interstellar clouds are derived and compared with the assumed, temperature-independent estimates publicly available in kinetic databases KIDA and UDfA. For a temperature of 10 K the database value overestimates by a factor of two the one obtained by us (thus improperly enhancing the destruction route of CH+ in astrochemical kinetic models) which is seen to double in the temperature range 5–300 K with a sharp increase in the first 50 K. The computed values are fitted via the popular Arrhenius–Kooij formula and best-fitting parameters α = 1:32 X 10-9 cm3s-1, β = 0:10 and γ = 2:19 K to be included in the online mentioned databases are provided. Further investigation shows that the temperature dependence of the thermal rate coefficient better conforms to the recently proposed so-called ‘deformed Arrhenius’ law by Aquilanti and Mundim.