3,424 research outputs found
Complementary action of chemical and electrical synapses to perception
Acknowledgements This study was possible by partial financial support from the following agencies: Fundação AraucĂĄria, EPSRC-EP/I032606/1, CNPq No. 441553/2014-1, CAPES No. 17656-12-5 and Science Without Borders Programâ Process Nos. 17656125, 99999.010583/2013-00 and 245377/2012-3.Peer reviewedPostprin
Alterations in brain connectivity due to plasticity and synaptic delay
Brain plasticity refers to brain's ability to change neuronal connections, as
a result of environmental stimuli, new experiences, or damage. In this work, we
study the effects of the synaptic delay on both the coupling strengths and
synchronisation in a neuronal network with synaptic plasticity. We build a
network of Hodgkin-Huxley neurons, where the plasticity is given by the Hebbian
rules. We verify that without time delay the excitatory synapses became
stronger from the high frequency to low frequency neurons and the inhibitory
synapses increases in the opposite way, when the delay is increased the network
presents a non-trivial topology. Regarding the synchronisation, only for small
values of the synaptic delay this phenomenon is observed
Generalized partition functions and interpolating statistics
We show that the assumption of quasiperiodic boundary conditions (those that
interpolate continuously periodic and antiperiodic conditions) in order to
compute partition functions of relativistic particles in 2+1 space-time can be
related with anyonic physics. In particular, in the low temperature limit, our
result leads to the well known second virial coefficient for anyons. Besides,
we also obtain the high temperature limit as well as the full temperature
dependence of this coefficient.Comment: 12 pages, Latex, updated and enlarged versio
Mathematical Models and Exact Algorithms for the Colored Bin Packing Problem
This paper focuses on exact approaches for the Colored Bin Packing Problem
(CBPP), a generalization of the classical one-dimensional Bin Packing Problem
in which each item has, in addition to its length, a color, and no two items of
the same color can appear consecutively in the same bin. To simplify modeling,
we present a characterization of any feasible packing of this problem in a way
that does not depend on its ordering. Furthermore, we present four exact
algorithms for the CBPP. First, we propose a generalization of Val\'erio de
Carvalho's arc flow formulation for the CBPP using a graph with multiple
layers, each representing a color. Second, we present an improved arc flow
formulation that uses a more compact graph and has the same linear relaxation
bound as the first formulation. And finally, we design two exponential
set-partition models based on reductions to a generalized vehicle routing
problem, which are solved by a branch-cut-and-price algorithm through
VRPSolver. To compare the proposed algorithms, a varied benchmark set with 574
instances of the CBPP is presented. Results show that the best model, our
improved arc flow formulation, was able to solve over 62% of the proposed
instances to optimality, the largest of which with 500 items and 37 colors.
While being able to solve fewer instances in total, the set-partition models
exceeded their arc flow counterparts in instances with a very small number of
colors
InfluĂȘncia da Ă©poca do ano e das diferentes concentraçÔes de ĂĄcido naftaleno acĂ©tico (NAA) no enraizamento de Mikania micrantha Kunth.
Organizado por Patricia PĂłvoa de Mattos, Celso Garcia Auer, Rejane Stumpf Sberze, Katia Regina Pichelli e Paulo CĂ©sar Botosso
Coupling Mars Ground and Orbital Views: Generate Viewsheds of Mastcam Images From the Curiosity Rover, Using ArcGISÂź and Public Datasets
The Mastcam (Mast Camera) instrument onboard the NASA Curiosity rover provides an exclusive view of Mars: Highâresolution color images from Mastcam allow users to study Gale crater's geologic terrains along Curiosity's path. These ground observations complement the spatially broader views of Gale crater provided by spacecrafts from orbit. However, for a given Mastcam image, it can be challenging to locate the corresponding terrains on the orbital view. No method for locating Mastcam images onto orbital images had been made publicly available. The procedure presented here allows users to generate Mastcam image viewsheds, using ArcGISÂź software, its builtâin Viewshed toolÂź, and public Mars datasets. This procedure locates onto Mars orbital view the terrains that are observed in a given Mastcam image. Because this procedure uses public datasets, it is applicable to available Mastcam images and to the future ones that will be acquired along the Curiosity rover's path. This procedure can be used by the public to assess scientific questions regarding Martian surface processes and geologic history. In addition, this procedure can be utilized as pedagogic GIS material by the Geosciences or Planetary Sciences communities, for enhancing students' skillsets in GIS and provide students with experience working with datasets from both orbiter and rover Mars missions
Coupling Mars Ground and Orbital Views: Generate Viewsheds of Mastcam Images From the Curiosity Rover, Using ArcGISÂź and Public Datasets
The Mastcam (Mast Camera) instrument onboard the NASA Curiosity rover provides an exclusive view of Mars: Highâresolution color images from Mastcam allow users to study Gale crater's geologic terrains along Curiosity's path. These ground observations complement the spatially broader views of Gale crater provided by spacecrafts from orbit. However, for a given Mastcam image, it can be challenging to locate the corresponding terrains on the orbital view. No method for locating Mastcam images onto orbital images had been made publicly available. The procedure presented here allows users to generate Mastcam image viewsheds, using ArcGISÂź software, its builtâin Viewshed toolÂź, and public Mars datasets. This procedure locates onto Mars orbital view the terrains that are observed in a given Mastcam image. Because this procedure uses public datasets, it is applicable to available Mastcam images and to the future ones that will be acquired along the Curiosity rover's path. This procedure can be used by the public to assess scientific questions regarding Martian surface processes and geologic history. In addition, this procedure can be utilized as pedagogic GIS material by the Geosciences or Planetary Sciences communities, for enhancing students' skillsets in GIS and provide students with experience working with datasets from both orbiter and rover Mars missions
Avaliação in vitro do potencial bioativo da andiroba (carapa guianensis) sobre ovos de nematódeos gastrintestinais de bovinos e larvas l3 de cooperia sp.
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