Recording from two neurons: second order stimulus reconstruction from spike trains and population coding

We study the reconstruction of visual stimuli from spike trains, recording simultaneously from the two H1 neurons located in the lobula plate of the fly Chrysomya megacephala. The fly views two types of stimuli, corresponding to rotational and translational displacements. If the reconstructed stimulus is to be represented by a Volterra series and correlations between spikes are to be taken into account, first order expansions are insufficient and we have to go to second order, at least. In this case higher order correlation functions have to be manipulated, whose size may become prohibitively large. We therefore develop a Gaussian-like representation for fourth order correlation functions, which works exceedingly well in the case of the fly. The reconstructions using this Gaussian-like representation are very similar to the reconstructions using the experimental correlation functions. The overall contribution to rotational stimulus reconstruction of the second order kernels - measured by a chi-squared averaged over the whole experiment - is only about 8% of the first order contribution. Yet if we introduce an instant-dependent chi-square to measure the contribution of second order kernels at special events, we observe an up to 100% improvement. As may be expected, for translational stimuli the reconstructions are rather poor. The Gaussian-like representation could be a valuable aid in population coding with large number of neurons

Photoassociative creation of ultracold heteronuclear 6Li40K* molecules

We investigate the formation of weakly bound, electronically excited, heteronuclear 6Li40K* molecules by single-photon photoassociation in a magneto-optical trap. We performed trap loss spectroscopy within a range of 325 GHz below the Li(2S_(1/2))+K(4P_(3/2)) and Li(2S_(1/2))+K(4P_(1/2)) asymptotic states and observed more than 60 resonances, which we identify as rovibrational levels of 7 of 8 attractive long-range molecular potentials. The long-range dispersion coefficients and rotational constants are derived. We find large molecule formation rates of up to ~3.5x10^7s^(-1), which are shown to be comparable to those for homonuclear 40K_2*. Using a theoretical model we infer decay rates to the deeply bound electronic ground-state vibrational level X^1\Sigma^+(v'=3) of ~5x10^4s^(-1). Our results pave the way for the production of ultracold bosonic ground-state 6Li40K molecules which exhibit a large intrinsic permanent electric dipole moment.Comment: 6 pages, 4 figures, submitted to EP

Efeito da terra de diatomácea sobre o desenvolvimento biológico de zabrotes subfasciatus em feijoeiro (Phaseolus vulgaris).

Este trabalho teve como objetivo verificar o efeito da terra de diatomácea no desenvolvimento biológico do caruncho Z. subfasciatus.CONAFE

Efeito da terra de diatomácea sobre a mortalidade de adultos de zabrotes subfasciatus em feijoeiro (Phaseolus vulgaris).

O objetivo deste trabalho foi avaliar o efeito da Terra de Diatomácea na mortalidade do caruncho do feijão Z. subfasciatus em diferentes períodos de armazenamento.CONAFE

Efeito da terra de diatomácea sobre Zabrotes subfasciatus em feijoeiro (Phaseolus vulgaris).

O objetivo deste trabalho foi avaliar o efeito da Terra Diatomácea na mortalidade do caruncho do feijão Zabrotes subfasciatus em diferentes períodos de armazenamento.Conpeex 2010

UAV GNSS position corrections based on IoT™ communication protocol

With the increase of devices connected to the Internet, currently known as Internet of Things (IoT), it is important to use algorithms in data transmissions to achieve optimal results for a given application.The paper main goal is to gather Global Navigation Satellite System (GNSS) positions at maximum rate possible, process them in a Post-processed Kinematics (PPK) environment, in order to perform GNSS corrections when compared to real earth GNSS coordinates. This method translates as micro-adjustments of the Unmanned Aerial Vehicle (UAV) traveled path, achieving centimeter-level accuracy associated with GNSS actual position. These GNSS positions are collected by the UAV GNSS receiver, and then sent to a gateway by using LoRaWAN™ communications protocol.Experimental results were included in the paper.info:eu-repo/semantics/acceptedVersio

Efeito da terra de diatomácea na mortalidade do caruncho do feijão Zabrotes subfasciatus.

Terra de diatomácea é um pó inerte extraído de depósitos fósseis de esqueletos de algas diatomáceas, cujo principal constituinte é a sílica. Esta causa a mortalidade do inseto por ação na abração e adsorção de lipídios da epicutícula, causando a morte por desidratação. Com o objetivo de verificar o efeito deste pó inerte na mortalidade do caruncho, 800 g de grãos de feijão da cultivar Pérola foram colocados em sacos plásticos e tratados com a terra de diatomácea (Keepdry®) na dosagem de um kg/tonelada de grãos

Poisson homology of r-matrix type orbits I: example of computation

In this paper we consider the Poisson algebraic structure associated with a classical $r$-matrix, i.e. with a solution of the modified classical Yang--Baxter equation. In Section 1 we recall the concept and basic facts of the $r$-matrix type Poisson orbits. Then we describe the $r$-matrix Poisson pencil (i.e the pair of compatible Poisson structures) of rank 1 or $CP^n$-type orbits of $SL(n,C)$. Here we calculate symplectic leaves and the integrable foliation associated with the pencil. We also describe the algebra of functions on $CP^n$-type orbits. In Section 2 we calculate the Poisson homology of Drinfeld--Sklyanin Poisson brackets which belong to the $r$-matrix Poisson family