A Novel Learning Rule for Long-Term Plasticity of Short-Term Synaptic Plasticity Enhances Temporal Processing

It is well established that short-term synaptic plasticity (STP) of neocortical synapses is itself plastic – e.g., the induction of LTP and LTD tend to shift STP towards short-term depression and facilitation, respectively. What has not been addressed theoretically or experimentally is whether STP is “learned”; that is, is STP regulated by specific learning rules that are in place to optimize the computations performed at synapses, or, are changes in STP essentially an epiphenomenon of long-term plasticity? Here we propose that STP is governed by specific learning rules that operate independently and in parallel of the associative learning rules governing baseline synaptic strength. We describe a learning rule for STP and, using simulations, demonstrate that it significantly enhances the discrimination of spatiotemporal stimuli. Additionally we generate a set of experimental predictions aimed at testing our hypothesis

Grand canonical ensemble of a dd-dimensional Reissner-Nordstr\"om black hole in a cavity

The grand canonical ensemble of a $d$-dimensional Reissner-Nordstr\"om black hole space in a cavity is analyzed. The realization of this ensemble is made through the Euclidean path integral approach by giving the Euclidean action for the black hole with the correct topology, and boundary conditions corresponding to a cavity, where the fixed quantities are the temperature and the electric potential. One performs a zero loop approximation to find and analyze the stationary points of the reduced action. This yields two solutions for the electrically charged black hole, $r_{+1}$, which is the smaller and unstable, and $r_{+2}$, which is the larger and stable. One also analyzes the most probable configurations, which are either a stable charged black hole or hot flat space, mimicked by a nongravitating charged shell. Making the correspondence between the action and the grand potential, one can get the black hole thermodynamic quantities, such as the entropy, the mean charge, the mean energy, and the thermodynamic pressure, as well as the Smarr formula, shown to be valid only for the unstable black hole. We find that thermodynamic stability is related to the positivity of the heat capacity at constant electric potential and area of the cavity. We also comment on the most favorable thermodynamic phases and phase transitions. We then choose $d = 5$, which is singled out naturally from the other higher dimensions as it provides an exact solution for the problem, and apply all the results previously found. The case $d = 4$ is mentioned. We compare thermodynamic radii with the photonic orbit radius and the Buchdahl-Andr\'easson-Wright bound radius in $d$-dimensional Reissner-Nordstr\"om spacetimes and find they are unconnected, showing that the connections displayed in the Schwarzschild case are not generic, rather they are very restricted holding only in the pure gravitational situation.Comment: 28 pages, 5 figure

Quantum state of a free spin-1/2 particle and the inextricable dependence of spin and momentum under Lorentz transformations

We revise the Dirac equation for a free particle and investigate Lorentz transformations on spinors. We study how the spin quantization axis changes under Lorentz transformations, and evince the interplay between spin and momentum in this context.Comment: 14 pages, 3 figures, published as a Review in the IJQ

Normal modes of Proca fields in AdS spacetime

A normal mode analysis for Proca fields in the anti-de Sitter (AdS) spacetime is given. It is found that the equations for the Proca field can be decoupled analytically. This is performed by changing the basis of the vector spherical harmonics (VSH) decomposition. The normal modes and the normal mode frequencies of the Proca equation in the AdS spacetime are then analytically determined. It is also shown that the Maxwell field can be recovered by taking the massless limit of the Proca field with care so that the nonphysical gauge modes are eliminated.Comment: 6 page

Redundancy and error resilience in Boolean Networks

We consider the effect of noise in sparse Boolean Networks with redundant functions. We show that they always exhibit a non-zero error level, and the dynamics undergoes a phase transition from non-ergodicity to ergodicity, as a function of noise, after which the system is no longer capable of preserving a memory if its initial state. We obtain upper-bounds on the critical value of noise for networks of different sparsity.Comment: 4 pages, 5 figure

Asymptotic integral kernel for ensembles of random normal matrices with radial potentials

We use the steepest descents method to study the integral kernel of a family of normal random matrix ensembles with eigenvalue distribution P_{N}(z_{1},...,z_{N}) = Z_{N}^{-1} e^{-NSigma_{i=1}^{N}V_{alpha}(z_{i})} Pi_{1leqi<jleqN}|z_{i}-z_{j}|^{2} where V_{alpha}(z)=|z|^{alpha}, z in C and alpha in ]0,infty[. Asymptotic analysis with error estimates are obtained. A corollary of this expansion is a scaling limit for the n-point function in terms of the integral kernel for the classical Segal--Bargmann space

Evaluation of Internal Markers for Estimating Duodenal Digesta Flow in Ruminants: Acid Detergent Fibre and Lignin Disappearance at the Lower Gastrointestinal Tract

Most of published studies carried out for estimating organic matter (OM) rumen digestibility (OMRD) use research an-imals fitted with simple t-type cannulas and an external or internal marker for estimating the duodenal digesta flow. Compared to external, the internal markers have the advan-tage of occurring naturally in diet and, consequently, they flow intimately associated with digesta (Titgemeyer 1997). Porter and Singleton (1971a) reported from a study with sheep fitted with re-entrant duodenal cannula that lignin degradation takes place entirely in the stomach. Thus, in digestibility studies where total faeces output is measured, duodenal digesta flow may be estimated based on both faeces output and the ratio of lignin concentration in faeces and in duodenal digesta. However, sulphuric acid lignin (ADL) is present in low concentrations in duodenal digesta and the precision of duodenal flow estimates is usually compromised. This study evaluated the disappearance at the lower gastrointestinal tract and, consequently, the po-tential use of acid detergent fibre (ADF), in comparison with ADL, as an internal marker for estimating duodenal digesta flow in cattle

Ventilation and deodorization system optimization of a wastewater treatment plant

Quality of life is entirely linked to air quality around us, whether inside or outside a building. Therefore, it is not surprising that the owners and occupants of certain spaces pay attention to the air quality, especially when they work or are close to a wastewater treatment plant. The aims of this work are to diagnose the existing situation in ventilation and deodorization system of covered wastewater treatment plant and to suggest changes to improve indoor air quality and make the operation of this system more reliable and economical. The ventilation system, consisting of 10 air handling units, supply 230.000 m3/h, where some ventilation lines have 250 m. The system’s optimization solution, as well as the two new centrifugal fans implementation, with speed variation, allow a reduction in the total fans power to 60 kW and increase the energy efficiency in 60 %

Evaluation of Acid Detergent Fibre, Sulphuric Acid Lignin and N-Alkanes as Markers for Estimating Ruminal Digestibility in Cattle

Most of the published studies on estimating organic matter (OM) rumen digestibility (OMRD) use research animals fitted with simple t-type cannulas and an external or inter-nal marker for estimating the duodenal digesta flow. Although there is not an ideal or standard marker, com-pared to external markers, internal markers have the advantage of occurring naturally in the diet and, conse-quently, they flow intimately associated with digesta (Titgemeyer 1997). In digestibility studies where total faec-es output is measured, duodenal digesta flow may be estimated based on both faeces output and the ratio of a marker concentration in faeces and in duodenal digesta. Sulphuric acid lignin (ADL) has been commonly used as an internal marker in this approach. However, its low concen-trations in duodenal digesta usually compromises estimate precision. The objective of this study was to evaluate acid detergent fibre (ADF) in comparison with ADL, as well as with n-alkanes, as a marker for estimating OMRD in cattle

Time Limit at vV02max and V02max Slow Component in Swimming: a pilot study of University Students

The aim oftms study was to measure in swimming-pool conditions, the time to exhaustion at the minimum velocity that elicits maximal oxygen consumption (TLim-vV02max) and to verify the existence of an oxygen uptake slow component (02SC) in freestyle swimming. Ten university students performed a continuous incremental protocol for vV02max assessment. Forty-eight hours later, they swam to exhaustion at vV02max to assess TLim-vV02max and 02SC. V02 was directly measured and swimming velocity was controlled by a visual pacer. Blood lactate concentrations ([La-]) and heart rate (HR) values were also measured. Mean V02max for the incremental test was 54.2±8.2 m1.kg'l.min'l, and the correspondent vV02max was 1.19±O.08 m.S,l The mean duration ofthe TLim-vV02max test was 325±76.5 s. 02SC appeared in the allout swim at VV02max (279.0±195.2 ml.min'l) and it was found to significant1y correlate with the TLim-vV02max (r = .74, p< .05). These results demonstrated that 02SC is observed also in swimming-pool conditions and that TLim-vV02max values are in accordance with typical formulations of aerobic power training sets for swimmers.We wish to thank Prof Dr. José Soares, from the Laboratory of Exercise Physiology of our faculty, for his significant contribution.info:eu-repo/semantics/publishedVersio