Temporal Control of Conditioned Responding in Goldfish.

The peak procedure was used to characterize response timing during acquisition and maintenance of conditioned responding in goldfish. Subjects received light-shock pairings with a 5- or 15-s interstimulus interval. On interspersed peak trials, the conditioned stimulus light was presented for 45 s and no shock was delivered. Peaks in the conditioned response, general activity, occurred at about the time of the expected unconditioned stimulus, and variability in the activity distribution was scalar. Modeling of the changes in the activity distributions over sessions revealed that the temporal features of the conditioned response changed very little during acquisition. The data suggest that times are learned early in training, and, contrary to I. P. Pavlov's (1927/1960) concept of "inhibition of delay," that timing is learning when to respond rather than learning when not to respond. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Survey and Evaluation of State‐of‐the‐Art Intelligent Question Routing Systems

In spite of great developments in artificial intelligence, human brain is still more powerful, concerning the comprehension and manipulation with partially known facts. One domain where this is prominent is related to a problem of question answering. When it comes to giving the answers, especially those that do not explicitly exist in the text corpus, the advantages of a human expert are abilities such as explaining, combining complex answers, and abstract reasoning. This paper represents a survey of the existing research in the domain of intelligent question routing. The survey starts from an original presentation paradigm that generalizes the essence of approaches found in the open literature. The presentation paradigm includes three basic processing stages related to the three major problems of system implementation: question analysis, question forwarding, and users’ knowledge profiling. Various research efforts use different approaches for implementation of each one of the basic processing stages. Each particular approach is described here using the same template. All these approaches are enlisted, discussed, and presented within a table, for easier comparison. The outcome of this analysis is a proposal for a new approach that tackles identified problems.     

Chemical Vapor Synthesis of FeOx–BaTiO3 Nanocomposites

Nanocomposite powders of FeO_x–BaTiO₃ (FO‐BTO) have been prepared by chemical vapor synthesis (CVS) in a single‐step process. The optimal parameters (reactor temperature, reactor length, precursor ratio) for the synthesis were investigated in an initial step for the individual systems, iron oxide (FO), and barium titanate (BTO); and in a second step optimized for the synthesis of the nanocomposites. The solid iron precursor was thermally evaporated, whereas the solid Ba‐ and Ti precursors were vaporized using laser flash evaporation to obtain ultrafine crystalline FO, BTO, and FO‐BTO nanoparticles. The possibility to influence the mass ratios of the two phases in FO‐BTO mixture by adjusting the ratio of the precursor in the two precursor delivery units has been investigated. The potential of CVS for the synthesis of nanocomposites containing iron oxide and barium titanate ultrafine crystalline nanopowders with particle size bellow 10 nm is demonstrated.     

EXAMINATION OF RHEOLOGICAL PROPERTIES OF FINE PARTICLES AS CARRIERS FOR CONTROLLED DRUG RELEASE

Development of lipid-based fine particles as potential drug carriers requires detailed investigation of possible effects of these carriers on rheological properties of blood. In this study, we have investigated the influence of dynamic conditions on aggregate formation and stability in dispersions of lipid-based fine particles in whole blood under in vitro conditions. Rheological parameters of two concentrations of liposome dispersion and two concentrations of lipid emulsion in blood were studied by assessing shear stress/shear rate relationships. The magnitude of attractive interactions between aggregates and/or particles, A, and the effective-to-real volume fraction of particles, ϕ f /ϕ p , were estimated for rheological quantification of lipid-based fine particles-blood interactions and aggregate stability. Addition of lipid-based particles induced aggregate formation in blood, which was more pronounced at higher concentrations of lipid-based fine particles. Furthermore, larger and more stable aggregates were formed in liposome dispersions as compared to lipid emulsions in blood.     

The effect of cryo-grinding and size separation on bioactive profile of buckwheat hulls

Buckwheat hulls (BWH) are a lignocellulosic material with valuable nutrient contents, especially rutin and dietary fibre, which are worth exploring from a food industry perspective. BWH are also a voluminous material that is difficult to grind to very fine particle sizes, which can be achieved under cryogenic conditions. Therefore, we investigated the effect of fractionation by cryo-grinding and size separation (<56, 56–180 and >180 µm) on the dietary fibre content and bioactive profile of BWH. While we hypothesised that micronisation would increase fibre solubility and release of bioactive compounds, we found that BWH must be fractionated to a size <56 µm to show a significant increase in soluble fibre content (106%), rutin (66%), total free phenolic compounds (94%) and antioxidant capacity (45–63%). Moreover, we have shown that near-infrared spectroscopy combined with partial least squares regression can be easily used for rapid scanning of BWH to select the most suitable pre-processing conditions for maximum nutritional value of this food industry by-product.     

Quality attributes and firming kinetics of partially baked frozen wholewheat bread with sourdough

Partially baked frozen (PBF) process prolongs bread shelf life, but diminishes its volume and crumb texture. Therefore, we investigated the possibility of using sourdough for the quality improvement in PBF wholewheat bread. Sourdough was fermented with either Lactobacillus plantarum, Lb. brevis or Leuconostoc mesenteroides mixed with yeast Candida humilis and added at 7.5, 15, 22.5 or 30% on bread dough basis. The choice of sourdough starter significantly affected bread acidity characteristics, flavour, specific volume, shape and crumb firmness. The sourdough amount and acetic acid content of bread inversely correlated to flavour score, specific volume, shape and crumb softness. The overall quality of PBF wholewheat bread was most efficiently improved after adding Lb. plantarum sourdough at 15–22.5%, resulting in retarded firming rate (74–94%) and improved specific volume (25–28%) in comparison with PBF bread without sourdough. Such sourdough has lactic to acetic acid higher than previously recommended for traditional sourbreads.     

The survival and persistence of Lactobacillus acidophilus LF221 in different ecosystems

Being a human isolate and bacterocin producer with wide antimicrobial spectrum, Lactobacillus acidophilus LF221 fulfills preliminary conditions as a potential probiotic strain. To investigate the LF221 strain with respect to its persistence in complex ecosystems, viable LF221 cells were orally administered to laboratory animals (mice and piglets) and added to cheese milk. During the 10-day feeding of mice with LF221 viable cells, 0.9% of lactobacilli isolated from faeces were identical with LF221 strain. Within the piglets' feeding trial, 920 lactobacilli colonies randomly selected from faecal samples were screened for the presence of LF221-like colonies. During the six times of sampling of piglets' faeces, LF221 colonies were always detected. Even the final sampling 10 days after the last LF221 cell suspension was dosed into piglets revealed the presence of LF221 strain at a concentration of about 3 x 10(8) cells/g of faeces. LF221 intake did not significantly influence the total count of lactobacilli in faecal samples and it had no negative health effects on animals. Analyses of cheese demonstrated that the LF221 strain maintained a high viability during ripening and that it could be detected for at least 6 weeks at a level of about 6.8 x 10(6) cells/g of cheese. According to these results, semihard cheese represents a suitable medium for introducing a potential probiotic LF221 into a diet.     

MoxWx–1S2 Nanotubes for Advanced Field Emission Application

Transition metal dichalcogenide (TMDC) nanotubes complement the field of low-dimensional materials with their quasi-1D morphology and a wide set of intriguing properties. By introducing different transition metals into the crystal structure, their properties can be tailored for specific purpose and applications. Herein, the characterization and a subsequent preparation of single-nanotube field emission devices of Mo_xW_x-1S₂ nanotubes prepared via the chemical vapor transport reaction is presented. Energy-dispersive X-ray spectroscopy, Raman spectroscopy, and X-ray diffraction  indicate that the molybdenum and tungsten atoms are randomly distributed within the crystal structure and that the material is highly crystalline. High resolution transmission electron microscopy  and electron diffraction (ED) patterns further corroborate these findings. A detailed analysis of the ED patterns from an eight-layer nanotube reveal that the nanotubes grow in the 2H structure, with each shell consists of one bilayer. The work function of the nanotubes is comparable to that of pure MoS₂ and lower of pure WS₂ NTs, making them ideal candidates for field emission applications. Two devices with different geometrical setup are prepared and tested as field emitters, showing promising results for single nanotube field emission applications.