Modelling human choices: MADeM and decision‑making

Research supported by FAPESP 2015/50122-0 and DFG-GRTK 1740/2. RP and AR are also part of the Research, Innovation and Dissemination Center for Neuromathematics FAPESP grant (2013/07699-0). RP is supported by a FAPESP scholarship (2013/25667-8). ACR is partially supported by a CNPq fellowship (grant 306251/2014-0)

Effect of carboxylic acids on the morphology, physical characteristics and hydration of <img src='/image/spc_char/alpha.gif' border=0>-hemihydrate plaster

337-344Hydration of -hemihydrate in the presence of different concentrations of tartaric, succinic, malic and citric acids was studied. All the acids, except tartaric acid, retard the hydrations. pH measurements have shown that during hydration acids are adsorbed at solid surfaces, leading to the retardation of hydration. E-modulus of elasticity, tensile strengths, total porosity, compressive strength, morphological and temperature changes during hydration were studied. It is found that morphological changes control the strength properties

Self-Consistent Scheme for Spike-Train Power Spectra in Heterogeneous Sparse Networks

Recurrent networks of spiking neurons can be in an asynchronous state characterized by low or absent cross-correlations and spike statistics which resemble those of cortical neurons. Although spatial correlations are negligible in this state, neurons can show pronounced temporal correlations in their spike trains that can be quantified by the autocorrelation function or the spike-train power spectrum. Depending on cellular and network parameters, correlations display diverse patterns (ranging from simple refractory-period effects and stochastic oscillations to slow fluctuations) and it is generally not well-understood how these dependencies come about. Previous work has explored how the single-cell correlations in a homogeneous network (excitatory and inhibitory integrate-and-fire neurons with nearly balanced mean recurrent input) can be determined numerically from an iterative single-neuron simulation. Such a scheme is based on the fact that every neuron is driven by the network noise (i.e., the input currents from all its presynaptic partners) but also contributes to the network noise, leading to a self-consistency condition for the input and output spectra. Here we first extend this scheme to homogeneous networks with strong recurrent inhibition and a synaptic filter, in which instabilities of the previous scheme are avoided by an averaging procedure. We then extend the scheme to heterogeneous networks in which (i) different neural subpopulations (e.g., excitatory and inhibitory neurons) have different cellular or connectivity parameters; (ii) the number and strength of the input connections are random (Erdős-Rényi topology) and thus different among neurons. In all heterogeneous cases, neurons are lumped in different classes each of which is represented by a single neuron in the iterative scheme; in addition, we make a Gaussian approximation of the input current to the neuron. These approximations seem to be justified over a broad range of parameters as indicated by comparison with simulation results of large recurrent networks. Our method can help to elucidate how network heterogeneity shapes the asynchronous state in recurrent neural networks

Multiple crustal sources for post-tectonic I-type granites in the Hercynian Iberian Belt

A post-tectonic plutonic array of felsic I-type granites crops out in the western Hercynian Iberian Belt. Isotope (Sr, N d, Pb) data favour the absence of an important input of juvenile magmas in late- to post- tectonic Hercynian felsic magmatism in western Iberia, but suggest a reworking of different crustal protoliths, including oceanic metabasic rocks accreted to mid-to-Iower crustal levels during the early stages of the collision. I-type granites were derived from different meta-igneous protoliths ranging from metabasic to felsic compositions depending on their geographical position from the external (e.g. Galicia-N Portugal, GNP) to the innermost continental areas (Spanish Central System and Los Pedroches Batholiths). The GNP 1- type pIu tons related to eo-Hercynian accretional terranes have lower initial 87Sr/86Sr ratios, lower negative εNd values, and higher 206PbP04Pb ratios than other I-type granites of the Central Iberian zone. These more isotopically primitive Hercynian I-type granites are important in tracking pre-Hercynian accreted oceanic lithosphere terranes