Local Field Potentials in the Gustatory Cortex Carry Taste Information

It has been recently shownthat localfield potentials (LFPs)fromthe auditory and visual cortices carry information about sensory stimuli, but whether this is a universal property of sensory cortices remains to be determined. Moreover, little is known about the temporal dynamics of sensory information contained in LFPs following stimulus onset. Here we investigated the time course of the amount of stimulus information in LFPs and spikes from the gustatory cortex of awake rats subjected to tastants and water delivery on the tongue. We found that the phase and amplitude of multiple LFP frequencies carry information about stimuli, which have specific time courses after stimulus delivery. The information carried by LFP phase and amplitude was independent within frequency bands, since the joint information exhibited neither synergy nor redundancy. Tastant information in LFPs was also independent and had a different time course from the information carried by spikes. These findings support the hypothesis that the brain uses different frequency channels to dynamically code for multiple features of a stimulus.

Estudo do crescimento, eficiência de biofiltração e cinética de absorção de nutrientes (N-NH, N-NO e P-PO4³) da macroalga Gracilaria cervicornis (Turner) J. Agardh

The objective of this study was to examine the growth of Gracilaria cervicornis cultured in a shrimp (Litopenaeus vannamei) pond and to determine the absorption efficiency and the kinetics parameters (Vmax, Ks e Vmax:Ks) of this macroalgae for the nutrients N-NO3-, N-NH4+ and P-PO4-3, aiming at its use as bioremediatory of eutrophicated environments. For this study, two experiments (field and laboratory) were developed. In the field study, the seaweed was examined in relation to the growth and the biomass. In the laboratory experiment, the absorption efficiency of G. cervicornis was measured through the monitoring of the concentration of the three nutrients (N-NO3-, N-NH4+ e P-PO4-3) during 5 hours and the kinetic parameters were determined through the formula of Michaelis-Menten. The results obtained in this study demonstrated that G. cervicornis benefited from the available nutrients in the pond, increasing 52.4% of its biomass value after 30 days of culture. It was evidenced that the variability of the biomass could be explained through the salinity, availability of light (transparency and solid particle in suspension) and concentration of N-NO3- in the environment. In the laboratory experiment, the highest absorption efficiency was found in the treatments with low concentration (5 µmol.L-1), being evidenced a reduction of up to 85,3%, 97,5% and 81,2% of N-NH4+, N-NO3- and P-PO43-, respectively. Regarding the kinetic parameters, G. cervicornis presented better ability in absorbing N-NH4+ in high concentrations (Vmax = 158,5 µmol g-1 dry wt h-1) and P-PO43- in low concentrations (Ks = 5 µmol.L-1 e Vmax:Ks = 10,3). The results of this study show that G. cervicornis could be cultivated in shrimp ponds, presents a good capacity of absorption for the tested nutrients and is a promising candidate for biorremediation in shrimp pond effluent

Efeito da moagem de alta energia na microestrutura e nas propriedades magnéticas do compósito wc-10%p.Co

This work a studied the high energy milling effect in microstructure and magnetic properties of the WC-10wt.%Co composite. The composite powders were prepared by mechanical mixed and milled at 2 hours, 100 hours, 200 hours and 300 hours in planetary milling. After this process the composite were compacted in stainless steel die with cylindrical county of 10 mm of diameter, at pressure 200 Mpa and sintered in a resistive furnace in argon atmosphere at 1400 oC for 5 min. The sintered composite were cutted, inlaid, sandpapered, and polished. The microestrutural parameters of the composite was analyzed by X-ray diffraction, scanning electronic microscopy, optical microscopy, hardness, magnetic propriety and Rietveld method analyze. The results shows, with milling time increase the particle size decrease, it possibility minor temperature of sintering. The increase of milling time caused allotropic transformation in cobalt phase and cold welding between particles. The cold welding caused the formation of the particle composite. The X-ray diffraction pattern of composite powders shows the WC peaks intensity decrease with the milling time increase. The X-ray diffraction pattern of the composite sintered samples shows the other phases. The magnetic measurements detected a significant increase in the coercitive field and a decrease in the saturation magnetization with milling time increase. The increase coercitive field it was also verified with decrease grain size with milling time increase. For the composite powders the increase coercitive field it was verified with particle size reduction and saturation magnetization variation is relate with the variation of free cobalt. The Rietveld method analyze shows at milling time increase the mean crystalline size of WC, and Co-cfc phases in composite sintered sample are higher than in composite powders. The mean crystallite size of Co-hc phase in composite powders is higher than in composite sintered sample. The mean lattice strains of WC, Co-hc and Co-cfc phases in composite powders are higher than in composite sintered samples. The cells parameters of the composite powder decrease at milling time increase this effect came from the particle size reduction at milling time increase. In sintered composite the cells parameters is constant with milling time increase

O conceito de consciência em o ser e o nada de J.-P. Sartre

This current discourse intends to prove how consciousness or Being-for-itself presents the idea that in its operation one can emphasize that it s Nothingness, transience and liberty in Jean-Paul Sartre s work O Ser e o Nada. To testify the proposed idea, the conception that Sartre gives to consciousness, representing nothingness, without any content that is connected to the possessor objects of a transphenomenal existence will be the starting point. This way, consciousness will be analyzed transcendently to the object that it s not, demonstrating its revealer-revealed condition, because it unveils a concrete world that exists against its idea, functioning as the revealer intentionality that there are beings instead of nothingness, obeying the ontological proof defended by Sartre. From this idea, every kind of consciousness will always be consciousness of something, a glance of the world, avoiding the fact that the consciousness could be considered nothing in the world. In order to live its original negation state of the world, apprehending this same world, with the purpose of a knowledge, it needs to be divided in two: the first degree consciousness or previous-reflexive cogito, that turns the proper reflexion possible, because, it s the consciousness proper transphenomenality of being different of all that connected to its existence being only its consequence; and the cogito, responsible to the positioning of the first degree consciousness, while aware of its own consciousness, that is, while being certain that knows. From this point, the way to untangle the consciousness or Being-for-itself will be developed as being Chasm, Liberty and transience. From this idea, it s intended to know how consciousness, that in Sartre s thoughts is originally nothing, could turn into Liberty that is presented in the field of transience? In other words, how these three internal structures imbricate one another to form consciousness in Sartre? First of all, it has to be considered the review of a conduct of human reality, the inquiry, that will be possible to understand how Nothingness exists as the mold of all kind of negation. After this, it will be shown, considering its way of existence, the human reality that is connected to Para-si, determined like nothingness, still is proposed like Liberty. Form this point, it will be possible to gleam how Liberty is lived deeply by Para-si in the shape of chasm, trying to how Para-si turns into nothingness, creating a chasm based on its proper liberty. Then, Liberty will be the proper mechanism used by Para-si to modificate its original chasm. The way Being-for-itself has to build to gain its goal will be projecting in transience, the building of something possible that brings one being back. However, will be demonstrated like Chasm can occupy the moment of a choice turning the decision instant an anguish stage, based on the failing of stability of the Being-for-itself, once nothingness persists in the field of the possibilities that human beings preserves in its essence while being essentially Liberty. From this idea, anguish will be studied as the proper consciousness of Liberty, being bad-faith the attempt of avoid Liberty trying to gain a shelter contradicting the fact that life is done of continual choices