12,405 research outputs found
Fractal Fluctuations and Quantum-Like Chaos in the Brain by Analysis of Variability of Brain Waves: A New Method Based on a Fractal Variance Function and Random Matrix Theory
We developed a new method for analysis of fundamental brain waves as recorded
by EEG. To this purpose we introduce a Fractal Variance Function that is based
on the calculation of the variogram. The method is completed by using Random
Matrix Theory. Some examples are given
Mockumentality: From Hyperfaces to Deepfakes
Hyperrealistic replicas of the human face owe their documentary value to the belief that they result from mechanical reproduction. The idea that a picture is automatically produced through a process of imprint taking is often enough to convince the viewer of its truthfulness and reliability, thus contributing to giving images an aura of authenticity and to creating the myth of pure objectivity. But what happens when the link between hyperrealism, mechanicalness, and truthfulness is disentangled? In 2017, French artist Raphael Fabre successfully applied for an ID card using a computer-generated picture where the real face was, in fact, an artificial, synthetic mask. Starting from this case study, the essay tackles the issue of the increasing overlapping of actual reality and digital (un)reality, particularly focusing on the concerns raised by the confusion between faces and masks caused by the rapid spread of so-called deepfakes in a world that speeds from documentality towards what I propose to call mockumentality
GreenPhylDB: A Gene Family Database for plant functional Genomics
With the increasing number of genomes being sequenced, a major objective is to transfer accurate annotation from characterised proteins to uncharacterised sequences. Consequently, comparative genomics has become a usual and efficient strategy in functional genomics. The release of various annotated genomes of plants, such as _O. sativa_ and _A. thaliana_, has allowed setting up comprehensive lists of gene families defined by automated methods. However, like for gene sequence, manual curation of gene families is an important requirement that has to be undertaken. GreenPhylDB comprises protein sequences of 12 plant species fully sequenced that were grouped into homeomorphic families using similarity-based methods. Clusters are finally processed by phylogenetic analysis to infer orthologs and paralogs that will be particularly helpful to study genome evolution. Previously, each cluster has to be curated (i.e. properly named and classified) using different sources of information. A web interface for plant gene families’ curation was developed for that purpose. This interface, accessible on GreenPhylDB ("http://greenphyl.cirad.fr":http://greenphyl.cirad.fr), centralizes external references (e.g. InterPro, KEGG, Swiss-Prot, PIRSF, Pubmed) related to all gene members of the clusters and shows statistics and automatic analysis. We believe that this synthetic view of data available for a gene cluster, combined with basic guidelines, is an efficient way to provide reliable method for gene family annotations
Water dynamics in different biochar fractions
Biochar is a carbonaceous porous material deliberately applied to soil to improve its fertility. The mechanisms through which biochar acts on fertility are still poorly understood. The effect of biochar texture size on water dynamics was investigated here in order to provide information to address future research on nutrient mobility towards plant roots as biochar is applied as soil amendment. A poplar biochar has been stainless steel fractionated in three different textured fractions (1.0-2.0mm, 0.3-1.0mm and <0.3mm, respectively). Water-saturated fractions were analyzed by fast field cycling (FFC) NMR relaxometry. Results proved that 3D exchange between bound and bulk water predominantly occurred in the coarsest fraction. However, as porosity decreased, water motion was mainly associated to a restricted 2D diffusion among the surface-site pores and the bulk-site ones. The X-ray \u3bc-CT imaging analyses on the dry fractions revealed the lowest surface/volume ratio for the coarsest fraction, thereby corroborating the 3D water exchange mechanism hypothesized by FFC NMR relaxometry. However, multi-micrometer porosity was evidenced in all the samples. The latter finding suggested that the 3D exchange mechanism cannot even be neglected in the finest fraction as previously excluded only on the basis of NMR relaxometry results. X-ray \u3bc-CT imaging showed heterogeneous distribution of inorganic materials inside all the fractions. The mineral components may contribute to the water relaxation mechanisms by FFC NMR relaxometry. Further studies are needed to understand the role of the inorganic particles on water dynamics
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