Identification of redundant and synergetic circuits in triplets of electrophysiological data

Neural systems are comprised of interacting units, and relevant information regarding their function or malfunction can be inferred by analyzing the statistical dependencies between the activity of each unit. Whilst correlations and mutual information are commonly used to characterize these dependencies, our objective here is to extend interactions to triplets of variables to better detect and characterize dynamic information transfer. Our approach relies on the measure of interaction information (II). The sign of II provides information as to the extent to which the interaction of variables in triplets is redundant (R) or synergetic (S). Here, based on this approach, we calculated the R and S status for triplets of electrophysiological data recorded from drug-resistant patients with mesial temporal lobe epilepsy in order to study the spatial organization and dynamics of R and S close to the epileptogenic zone (the area responsible for seizure propagation). In terms of spatial organization, our results show that R matched the epileptogenic zone while S was distributed more in the surrounding area. In relation to dynamics, R made the largest contribution to high frequency bands (14-100Hz), whilst S was expressed more strongly at lower frequencies (1-7Hz). Thus, applying interaction information to such clinical data reveals new aspects of epileptogenic structure in terms of the nature (redundancy vs. synergy) and dynamics (fast vs. slow rhythms) of the interactions. We expect this methodology, robust and simple, can reveal new aspects beyond pair-interactions in networks of interacting units in other setups with multi-recording data sets (and thus, not necessarily in epilepsy, the pathology we have approached here).Comment: 31 pages, 6 figures, 3 supplementary figures. To appear in the Journal of Neural Engineering in its current for

Time-Reversal-Violating Schiff Moment of 199Hg

We calculate the Schiff moment of the nucleus 199Hg, created by pi-N-N vertices that are odd under parity (P) and time-reversal (T). Our approach, formulated in diagrammatic perturbation theory with important core-polarization diagrams summed to all orders, gives a close approximation to the expectation value of the Schiff operator in the odd-A Hartree-Fock-Bogoliubov ground state generated by a Skyrme interaction and a weak P- and T-odd pion-exchange potential. To assess the uncertainty in the results, we carry out the calculation with several Skyrme interactions (the quality of which we test by checking predictions for the isoscalar-E1 strength distribution in 208Pb) and estimate most of the important diagrams we omit.Comment: 13 pages, 7 figure

320g Ionization-Heat Cryogenic Detector for Dark Matter Search in the EDELWEISS Experiment

The EDELWEISS experiment used in 2001 a 320g heat-and-ionization cryogenic Ge detector operated in a low-background environment in the Laboratoire Souterrain de Modane for direct WIMP detection. This detector presents an increase of more than 4 times the mass of previous detectors. Calibrations of this detector are used to determine its energy resolution and fiducial volume, and to optimize the detector design for the 1kg phase of the EDELWEISS-I experiment. Analysis of the calibrations and characteristics of a first series of 320g-detectors are presented.Comment: 4 pages, 3 figure

Correlação entre heterose e divergência genética em genótipos de maracujá amarelo.

Este trabalho avaliou a heterose de híbridos de maracujá amarelo, obtidos por cruzamentos dialélicos entre genótipos divergentes e a sua correlação com a distância genética obtida por meio de marcadores ISSR (Inter Simple Sequence Repeats). Os trinta híbridos resultantes do dialelo parcial apresentaram diferenças significativas para as variáveis: número de frutos (NF), peso do fruto (PF), produtividade (PROD), rendimento (REND) e sólidos solúveis totais (SST). Apenas a variável número de frutos apresentou efeitos aditivos no controle genético. Não foi observada correlação significativa pela estatística de Mantel entre distância genética vs heterose, capacidade específica de combinação e a média para as características analisadas, o que não permite predizer o comportamento dos híbridos de maracujazeiro

Ionospheric response to the 2009 sudden stratospheric warming over the equatorial, low, and middle latitudes in the South American sector

The present study investigates the ionospheric total electron content (TEC) and F-layer response in the Southern Hemisphere equatorial, low, and middle latitudes due to major sudden stratospheric warming (SSW) event, which took place during January-February 2009 in the Northern Hemisphere. In this study, using 17 ground-based dual frequency GPS stations and two ionosonde stations spanning latitudes from 2.8°N to 53.8°S, longitudes from 36.7°W to 67.8°W over the South American sector, it is observed that the ionosphere was significantly disturbed by the SSW event from the equator to the midlatitudes. During day of year 26 and 27 at 14:00 UT, the TEC was two times larger than that observed during average quiet days. The vertical TEC at all 17 GPS and two ionosonde stations shows significant deviations lasting for several days after the SSW temperature peak. Using one GPS station located at Rio Grande (53.8°S, 67.8°W, midlatitude South America sector), it is reported for the first time that the midlatitude in the Southern Hemisphere was disturbed by the SSW event in the Northern Hemisphere.Fil: Fagundes, P. R.. Universidade do Vale do Paraíba; BrasilFil: Goncharenko, L. P.. Massachusetts Institute of Technology; Estados UnidosFil: De Abreu, A. J.. Universidade do Vale do Paraíba; BrasilFil: Venkatesh, K.. Universidade do Vale do Paraíba; BrasilFil: Pezzopane, M.. Istituto Nazionale Di Geofisica E Vulcanologia; ItaliaFil: De Jesus, R.. Universidade do Vale do Paraíba; BrasilFil: Gende, Mauricio Alfredo. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Coster, A. J.. Massachusetts Institute of Technology; Estados UnidosFil: Pillat, V. G.. Universidade do Vale do Paraíba; Brasi

Variabilidade molecular em genótipos de passiflora edulis sims.

O objetivo deste estudo foi caracterizar acessos não melhorados (GNM) e melhorados (GM) do Banco Ativo de Germoplasma de Maracujazeiro (BAG-Maracujá), além de um híbrido comercial (BRS GA) e 12 em fase de avaliação (HIB) e 19 progênies de meios irmãos (SEDPMI), oriundos do programa de melhoramento genético da Embrapa Mandioca e Fruticultura (PMGM-CNPMF) com o uso de marcadores ISSR (Inter Simple Sequence Repeats). A variação dos genótipos foi avaliada pelo método de agrupamento neighbor joining e por análise de componentes principais. A análise de variância molecular (AMOVA) foi utilizada para verificar a diferenciação entre os grupos de acordo com o grau de melhoramento. Os resultados dos agrupamentos mostraram a formação de dois grupos bem distintos: um proveniente de germoplasma e outro do PMGM-CNPMF. A AMOVA evidenciou que 57% da variação estão entre e 43% dentro dos grupos. Este estudo pode auxiliar na definição de estratégias mais eficientes a serem utilizadas no programa de melhoramento de maracujá amarelo assim como no direcionamento dos cruzamentos entre os genótipos mais contrastantes

Resistance sources to root-knot nematode Meloidogyne enterolobii in Solanum species.

The objective of this work was to prospect sources of resistance to root-knot nematode Meloidogyne enterolobii in Solanum species with potential to be used as rootstocks for cultivated Solanaceae. Nine accessions of Solanum sessiliflorum, 27 accessions of S. lycocarpum, 21 accessions of S. acanthodes, 22 accessions of S. scinericum and 26 accessions of S. scuticum for resistance to M. enterolobii. Rutgers and Nemadoro tomatoes were used as susceptible and resistant controls, respectively

Caracterização de acessos silvestres de maracujazeiro com base em descritores morfoagronômicos.

Existem espécies silvestres de maracujazeiros que possuem potencial agronômico para a utilização no melhoramento genético e no desenvolvimento de variedades e híbridos, porém a escassez de informações morfoagronômicas dessas espécies silvestres indica a necessidade de estudos básicos relacionados à caracterização e à avaliação do germoplasma. Este trabalho teve como objetivo caracterizar acessos silvestres de maracujazeiro, com base em descritores qualitativos e quantitativos

CYCLOIDAL GAIT WITH DOUBLE SUPPORT PHASE FOR THE NAO HUMANOID ROBOT

The commercial Nao humanoid robot has 11 DOF in legs. Even if these legs include 12 revolute joints, only 11 actuators are employed to control the walking of the robot. Under such conditions, the mobility of the pelvis and that of the oscillating foot are mutually constrained at each step. Besides, the original gait provided by the manufacturer company of the Nao employs only single support phases during the walking. Because of both issues, the reduced mobility in legs and the use of only single support phases, the stability of the walking is affected. To contribute to improving such stability, in this paper an approach is proposed that incorporates a double support phase and a gait based on cycloidal time functions for motions of the pelvis and those of the oscillating foot. To assess the stability of the walking an index is applied, which is based on the notion of zero-moment point (ZMP) of the static foot at each step. Results of experimental tests show that the proposed gait enhances the stability of the robot during the walking

CYCLOIDAL GAIT WITH DOUBLE SUPPORT PHASE FOR THE NAO HUMANOID ROBOT

The commercial Nao humanoid robot has 11 DOF in legs. Even if these legs include 12 revolute joints, only 11 actuators are employed to control the walking of the robot. Under such conditions, the mobility of the pelvis and that of the oscillating foot are mutually constrained at each step. Besides, the original gait provided by the manufacturer company of the Nao employs only single support phases during the walking. Because of both issues, the reduced mobility in legs and the use of only single support phases, the stability of the walking is affected. To contribute to improving such stability, in this paper an approach is proposed that incorporates a double support phase and a gait based on cycloidal time functions for motions of the pelvis and those of the oscillating foot. To assess the stability of the walking an index is applied, which is based on the notion of zero-moment point (ZMP) of the static foot at each step. Results of experimental tests show that the proposed gait enhances the stability of the robot during the walking