Search results for "Potential"

Paradoxical effect of increased diastolic Ca(2+) release and decreased sinoatrial node activity in a mouse model of catecholaminergic polymorphic ven…

2012

Background— Catecholaminergic polymorphic ventricular tachycardia is characterized by stress-triggered syncope and sudden death. Patients with catecholaminergic polymorphic ventricular tachycardia manifest sinoatrial node (SAN) dysfunction, the mechanisms of which remain unexplored. Methods and Results— We investigated SAN [Ca 2+ ] i handling in mice carrying the catecholaminergic polymorphic ventricular tachycardia–linked mutation of ryanodine receptor (RyR2 R4496C ) and their wild-type (WT) littermates. In vivo telemetric recordings showed impaired SAN automaticity in RyR2 R4496C mice after isoproterenol injection, analogous to what was observed in catecholaminergic polymorphic ventricul…

Cerebral Dynamics during the Observation of Point-Light Displays Depicting Postural Adjustments

2017

Objective: As highly social creatures, human beings rely part of their skills of identifying, interpreting, and predicting the actions of others on the ability of perceiving biological motion. In the present study, we aim to investigate the electroencephalographic (EEG) cerebral dynamics involved in the coding of postural control and examine whether upright stance would be codified through the activation of the temporal-parietal cortical network classically enrolled in the coding of biological motion. Design: We registered the EEG activity of 12 volunteers while they passively watched point light displays (PLD) depicting quiet stable (QB) and an unstable (UB) postural situations and their r…

Bilaterally recorded multiple-unit activity of the cingulate cortex during head turning conditioning with unilateral medial forebrain bundle stimulat…

1993

Cats were conditioned to turn their heads using a tone conditioned stimulus (CS) and medial forebrain bundle stimulation (MFB) unconditioned stimulus (US). The CS+ was delivered to one ear at a time, in random order, followed by the US. A tone of a different frequency was used as a CS-. The cats learned to respond differentially to the CSs showing head movements of greater acceleration to the CS+ than CS- over sessions. Bilateral recordings of cingulate cortex multiple-unit activity showed increased response amplitudes over sessions and larger responses in the hemisphere ipsilateral to the US. Since ipsilateral multiple-unit responses did not differ for the CSs, the asymmetry was probably d…

Asymmetries in classically conditioned head movements and cingulate cortex slow potentials in cats.

1991

Presuming that conditioned head movements in the cat indicate a preference for a specific direction, asymmetries were also expected to be found in bilaterally recorded cingulate cortex slow potentials to a symmetrical tone stimulus during discriminative conditioning. Conditioned stimuli (CS, 1000 and 2500 Hz tones) were delivered through two miniature loudspeakers fitted to the head in front of both ears. The unconditioned stimulus (US) was an electrical stimulation of either the left or right lateral hypothalamus yielding, in addition to its rewarding effects, an unconditioned head turning response (UR) either to the left, right, forwards or upwards. Discrimination learning appeared as mor…

Unilateral medial forebrain bundle activation selectively enhances conditioned orienting head turns and ipsilateral cingulate cortex evoked field res…

1994

Effects of a unilateral medial forebrain bundle (MFB) stimulation unconditioned stimulus (US) on conditioned head turn and bilateral cingulate cortex field potentials were studied in cats. Conditioned stimuli (CSs) of different frequences were given randomly to either ear. The CS+ was followed by the US, and the CS— was presented alone. Before conditioning most cats predominantly turned toward the ear to which the CSs were presented, whereas after conditioning the head turns were in one direction, most prominently contralateral to the US. Negative field potentials were greater in the cingulate cortex ipsilateral to the US than in the cingulate cortex contralateral to the US. Cross correlati…

Sparse Distributed Representation of Odors in a Large-scale Olfactory Bulb Circuit

2013

In the olfactory bulb, lateral inhibition mediated by granule cells has been suggested to modulate the timing of mitral cell firing, thereby shaping the representation of input odorants. Current experimental techniques, however, do not enable a clear study of how the mitral-granule cell network sculpts odor inputs to represent odor information spatially and temporally. To address this critical step in the neural basis of odor recognition, we built a biophysical network model of mitral and granule cells, corresponding to 1/100th of the real system in the rat, and used direct experimental imaging data of glomeruli activated by various odors. The model allows the systematic investigation and g…

Amyloid fibrils formation and amorphous aggregation in Concanavalin A

2007

We here report an experimental study on the thermal aggregation process of concanavalin A, a protein belonging to the legume lectins family. The aggregation process and the involved conformational changes of the protein molecules were followed by means of fluorescence techniques, light scattering, circular dichroism, zeta potential measurements and atomic force microscopy. Our results show that the aggregation process of concanavalin A may evolve through two distinct pathways leading, respectively, to the formation of amyloids or amorphous aggregates. The relative extent of the two pathways is determined by pH, as amyloid aggregation is favored at high pH values ( approximately 9), while th…

Circulating miRNA expression analysis reveals new potential biomarkers for human cutaneous melanoma staging.

2019

Recurrent deficit irrigation and fruit harvest affect tree water relations and fruitlet growth in ‘valencia’ orange

2019

Background – Partial rootzone drying is an irrigation strategy known for increasing water use efficiency without significantly affecting tree water status. ‘Valencia’ oranges have a very long development period and nearly mature fruit and new fruitlets may be present at the same time on the tree, competing for water and assimilates. Objectives – The present study investigates the effect of recurrent deficit irrigation and fruit harvest on tree water status and fruitlet growth of ‘Valencia’ orange. Methods – Forty-eight adult trees were exposed to three irrigation treatments for seven years (2007–2013): irrigation with 100% of ETc (CI), continuous deficit irrigation (DI, 50% of CI) and parti…

Turma Alfa: a dilemática fronteira entre práticas educativas inclusivas e práticas educativas exclusivas

2018

Abstract: This paper stems from an ongoing investigation on the theme "Educating places: practices, voices and pathways of inclusive education”. This project seeks to answer, among others, the following questions: i) which processes and factors, subjects, action rationales and (institutional, local, community) partnerships contribute to building local inclusive education practices, in the views of actors involved?; ii) which (social, institutional, biographical) processes and factors stop the negative spiral of school underachievement, school dropout and early school leaving and favour the youngsters’ remobilization to learn and build successful academic pathways?The study design consists o…