Construction of point process adaptive filter algorithms for neural systems using sequential Monte Carlo methods

The stochastic state point process filter (SSPPF) and steepest descent point process filter (SDPPF) are adaptive filter algorithms for state estimation from point process observations that have been used to track neural receptive field plasticity and to decode the representations of biological signals in ensemble neural spiking activity. The SSPPF and SDPPF are constructed using, respectively, Gaussian and steepest descent approximations to the standard Bayes and Chapman-Kolmogorov (BCK) system of filter equations. To extend these approaches for constructing point process adaptive filters, we develop sequential Monte Carlo (SMC) approximations to the BCK equations in which the SSPPF and SDPPF serve as the proposal densities. We term the two new SMC point process filters SMC-PPFs and SMC-PPFD, respectively. We illustrate the new filter algorithms by decoding the wind stimulus magnitude from simulated neural spiking activity in the cricket cercal system. The SMC-PPFs and SMC-PPFD provide more accurate state estimates at low number of particles than a conventional bootstrap SMC filter algorithm in which the state transition probability density is the proposal density. We also use the SMC-PPFs algorithm to track the temporal evolution of a spatial receptive field of a rat hippocampal neuron recorded while the animal foraged in an open environment. Our results suggest an approach for constructing point process adaptive filters using SMC methods.     

TRACKING PERFORMANCE OF CONTROL METHODS

In this work, the optimal temperature control of a styrene solution polymerization reactor with two different control algorithms is considered. DMC and PFD control mefhods are used to accomplish the optimal temperature control of the polystyrene reactor. Reactor optimal temperature profiles at different initiator initiation concentrations were obtained by applying maximum principle to the mathematical model of the free radical batch polymerization reactor lo produce polystyrene with desired conversion and molecular weight in a minimum lime. The results obtained from the experimental implementation of DMC and PID controller for the control of optimal temperature path of the polymerization reactor were compared.     

Investigation of zinc(II) adsorption on Cladophora crispata in a two‐staged reactor

In this study, the adsorption of zinc(II) ions on Cladophora crispata, a green alga, was studied with respect to initial pH, temperature, initial metal ion and biomass concentration in order to determine the optimum adsorption conditions. Optimum initial pH values for zinc(II) ions were found to be 5.0 at optimum temperature, 25 °C. The initial adsorption rates increased with increasing initial zinc(II) ion concentration up to 100 mgdm⁻³. The Freundlich and Langmuir adsorption isotherms were developed at various initial pH and temperature values. Then, the adsorption of zinc(II) ions to C crispata was investigated in a two‐staged mixed batch reactor. The residual metal ion concentrations (C_eq) at equilibrium at each stage for a given quantity of dried algae (X_o)/volume of solution containing heavy metal ion (V_o) ratio were calculated by using Freundlich and Langmuir isotherm constants. It was observed that the experimental biosorption equilibrium data for zinc(II) ions are in good agreement with those calculated using both Freundlich and Langmuir models. The adsorbed zinc(II) ion concentration increased with increasing X_o/V_o ratios while the adsorbed metal quantities per unit mass of dried algae decreased. © 2000 Society of Chemical Industry     

Untersuchung der Rinde von Pinus canariensis Smith

Successive solvent extractive yield and the chemical composition of P. canariensis bark were evaluated. In comparison to other pine barks yield and amount of phenolic material in bark hot water extracts are extremely high. Catechin and taxifolin were identified in the ether percolate of the hot water extract. The average molecular weight of the polyphenolic compounds and the viscosity of concentrated extract solutions are relatively low, which makes the hot water extract an interesting raw material for the formulation of thermosetting wood adhesives. Preliminary gluing tests gave promising results.     

Die Verwendung von natürlichen Polyphenolen zur Herstellung von Holzleimen

Increasing prices for petroleum derived chemicals lead to a growing interest in renewable raw materials. As the primary materials for the production of wood adhesives are also mainly based on petroleum, natural polyphenols are considered a possible substitute. The chemical constitution of natural polyphenols and recent developments in the field of tannin adhesives are reviewed.     

Untersuchung der Rindenextrakte von Pinus brutia Ten

P. brutia bark yields a high percentage of extractives. By sequential extraction with solvents of increasing polarity and diluted alkali up to 70% of bark substance can be dissolved, the residue being holocellulose and lignin-like material. Extraction of bark with hot water gives about 25% extractives, 80% of which are phenolic compounds.     

Identification and characterization of lactic acid bacteria isolated from traditional cone yoghurt

Cone yoghurt is a yoghurt variety produced by adding only pine cones to milk without culture in a limited area of Turkey. The present study was conducted to identify and characterize lactic flora in traditional cone yoghurt. Morphological, cultural, physiological, biochemical, and genotypic characteristics were employed to identify lactic acid bacteria isolates from cones and cone yoghurts. Streptococcus salivarius subsp. thermophilus (S. thermophilus) and Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus) were obtained from both cones and yoghurts. Among the isolates, L. plantarum was frequently isolated except for these two bacteria (S. thermophilus and L. bulgaricus). The results indicate that the cone yoghurt has a mixed microflora contrary to the yoghurt produced by the addition of a starter culture and S. thermophilus, and L. bulgaricus in cone yoghurt originates from the pine cones.     

Lipase catalyzed synthesis of oleyl oleate: Optimization by response surface methodology

Lipase catalyzed production of oleyl oleate, which is an analogue of jojoba oil, was carried out using oleic acid and oleyl alcohol in the solvent-free system. Novozym 435, immobilized Candida antarctica lipase, was used as a biocatalyst. Response surface methodology (RSM) based on five-level, four-variable central composite rotatable design was used to evaluate the effects of important parameters on the production of oleyl oleate. Acid/alcohol molar ratio (0.5-1.5), enzyme quantity (2-10% w/w of substrates), reaction temperature (40-60°C), and reaction time (30-90 min) were chosen as process variables for the optimization. Among these parameters, enzyme quantity and acid/alcohol molar ratio have significant effects compared with temperature and time on the production of oleyl oleate. Optimum conditions were found to be a acid/alcohol molar ratio of 1, enzyme quantity of 7% (w/w), reaction temperature of 51°C, and reaction time of 75 min. The coefficient of determination (R 2 ) for the model is 0.97. Probability value is 2.9 ‐ 10 m 9 (P-value<0.01). This P-value demonstrates a very high significance for the regression model. The maximum oleyl oleate concentration predicted by the equation (737 g/L) agrees well with the experimentalvalue (734 g/L) obtained from the experimental verification at the optimum values.     

The contribution of sport fan social identity to the production of prosocial behavior.

Experimenters observed the number of sport-team-identified fans who contributed money to charity workers before and after 6 football games. Charity workers were identified as supporters of 1 of the 2 teams competing, or of neither team. Consistent with predictions, more fans contributed to in-group than to out-group-supporting charity workers. In addition, charity workers identified with either team received a higher frequency of contributions from fans of both teams together after the game relative to before; this pattern was reversed among charity workers not identified with a team. This unexpected finding suggests an increased salience of a general sport-fan identification after the game relative to before. Finally, fans of winning teams in particular contributed more to any charity worker (i.e., collapsed across in-group, out-group, and neutral supporters) after the game than before, but this pattern was reversed among fans of losing teams. This final finding is discussed with reference to both self-categorization theory and the literature on mood and prosocial behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)