Stability and Evolution of Synonyms and Homonyms in Signaling Game

Synonyms and homonyms appear in all natural languages. We analyze their evolution within the framework of the signaling game. Agents in our model use reinforcement learning, where probabilities of selection of a communicated word or of its interpretation depend on weights equal to the number of accumulated successful communications. When the probabilities increase linearly with weights, synonyms appear to be very stable and homonyms decline relatively fast. Such behavior seems to be at odds with linguistic observations. A better agreement is obtained when probabilities increase faster than linearly with weights. Our results may suggest that a certain positive feedback, the so-called Metcalfe’s Law, possibly drives some linguistic processes. Evolution of synonyms and homonyms in our model can be approximately described using a certain nonlinear urn model.     

Effect of Ozone-Treated or Untreated Saskatoon Fruits (Amelanchier alnifolia Nutt.) Applied as an Additive on the Quality and Antioxidant Activity of Fruit Beers

Fruit of Saskatoon (Amelanchier alnifolia Nutt.) are a good source of bioactive compounds, such as polyphenols, including anthocyanins, as well as vitamins, macro- and microelements and fibre. By treating Saskatoon fruits with gaseous ozone, and adding the material as an enhancer to barley beers, it is possible to impact the contents of bioactive compounds in the produced fruit beers. Sensory tests showed that beers made from barley with addition of Saskatoon fruit of the ‘Smoky’ cultivar were characterised by the most balanced taste and aroma. Physicochemical analyses of fruit beers, produced with Saskatoon fruit pulp added on the seventh day of fermentation, showed that the beers enhanced with ozone-treated and untreated ‘Smoky’ Saskatoon fruits had the highest contents of alcohol, 5.51% v/v and 5.66% v/v, respectively, as well as total polyphenol contents of 395 mg GAE/L and 401 mg GAE/L, respectively, and higher antioxidant activity (assessed using DPPH^•, FRAP and ABTS^+• assays). It was demonstrated that the ozonation process led to a decrease in the contents of neochlorogenic acid, on average by 91.00%, and of caffeic acid by 20.62%, relative to the beers enhanced with ‘Smoky’ Saskatoon fruits not subjected to ozone treatment. The present study shows that Saskatoon fruits can be used in the production of beer, and the Canadian cultivar ‘Smoky’ is recommended for this purpose.     

Comparison of the impact of the addition of three alkaline earth metal oxides BaO,SrO and ZnO on sintering of glass–ceramic glazes from the SiO2–Al2O2–CaO–MgO–Na2O–K2O system

Journal of Thermal Analysis and Calorimetry - Glazes are the most important elements in the technology of producing the ceramic wares. They not only give aesthetic effects, like color and gloss,...     

Magnetic brillouin zone effect on the resistivity of semimetallic-like fermi surface in USb

To probe the effect of the protein environment on the retinal chromophore of rhodopsin, we performed molecular dynamics simulations using combined quantum mechanics/molecular mechanics (QM/MM). The starting geometry of the protein is based on the 2.6Å X-ray structure of bovine rhodopsin of Okada et al. [T. Okada, et al. Proc. Natl. Acad. Sci. USA 99 5982 (2002)]. The wild-type chromophore of rhodopsin according to our calculations shows a highly twisted conformation around the central region, from C10 to C13, due to non-bonded interaction with the protein pocket. The absolute sense of twist of the C11–C12 and C12–C13 bonds is negative (?19 ± 9°) and positive (170 ± 8°), respectively. The 13-demethyl retinal chromophore, in which the methyl group at the C13 position is removed, is less distorted in this region. The C11–C12 bond is less twisted (?15 ± 10°) and the C12–C13 bond is planar (179 ± 9°) . The flattened geometry of this artificial chromophore is supported by spectroscopic evidence.     

Model-Independent Normalization Condition for Gamow Vectors

Two comments on the theory of Gamow states are presented. First, it is shown that Gamow states may be viewed as two resonating states which correspond to two different eigenproblems for the same real value of energy. Second, a universal normalization condition for all Gamow states is derived.     

α‐Amino Acid‐Isosteric α‐Amino Tetrazoles

The synthesis of all 20 common natural proteinogenic and 4 otherα‐amino acid‐isosteric α‐amino tetrazoles has been accomplished, whereby the carboxyl group is replaced by the isosteric 5‐tetrazolyl group. The short process involves the use of the key Ugi tetrazole reaction followed by deprotection chemistries. The tetrazole group is bioisosteric to the carboxylic acid and is widely used in medicinal chemistry and drug design. Surprisingly, several of the common α‐amino acid‐isosteric α‐amino tetrazoles are unknown up to now. Therefore a rapid synthetic access to this compound class and non‐natural derivatives is of high interest to advance the field.     

Rime samples characterization and comparison using classical and fuzzy principal components analysis

The main objective of this paper is to introduce principal component analysis and two robust fuzzy principal component algorithms as useful tools in characterizing and comparing rime samples collected in different locations in Poland (2004–2007). The efficiency of the applied procedures was illustrated on a data set containing 108 rime samples and concentration of anions, cations, HCHO, as well as pH and conductivity. The fuzzy principal component algorithms achieved better results mainly because they are more compressible than classical PCA and very robust to outliers. For example, a three component model, fuzzy principal component analysis-first component (FPCA-1) accounts for 62.37% of the total variance and fuzzy principal component analysis-orthogonal (FPCA-o) 90.11%; PCA accounts only for 58.30%. The first two principal components explain 51.41% of the total variance in the case of FPCA-1 and 79.59% in the case of FPCA-o as compared to only 47.55% for PCA. As a direct consequence, PCA showed only a partial differentiation of rime samples onto the plane or in the space described by different combination of two or three principal components, whereas a much sharper differentiation of the samples, regarding their origin and location, is observed when FPCAs are applied.      

Molecular dynamics modeling in quantum chemical calculations. Optical absorption spectra of 1,3-Dimethyl-1H-Pyrazolo[3,4-b]quinoline derivatives

Paper presents the quantum chemical modeling of the optical absorption spectra of 6-fluoro, 6-bromo, 7-trifluoromethyl, 6-cyano and 6-carboethoxy derivatives of 1,3-Dimethyl-1H-Pyrazolo[3,4-b]quinoline. The calculations are performed by means of the semiempirical quantum chemical methods (AM1 or PM3) in combination with molecular dynamics (MD) simulations at T=300 K. It is shown that a particular rotational dynamics of the methyl, trifluoromethyl or ethyl groups practically does not influence the optical absorption in the spectral range 200-500 nm whereas broadening of absorption bands may be well reproduced within MD simulations including all types of nuclei vibrations. The results of calculations are compared with the measured spectra of optical absorption. The quantum chemical method AM1 in combination with MD simulations gives for all dyes the best agreement between the calculated and measured spectral positions of the first absorption band (absorption threshold).     

Assessment of 4-nitrogenated benzyloxymethyl groups for 2'-hydroxyl protection in solid-phase RNA synthesis

The search for a 2'-OH protecting group that would impart ribonucleoside phosphoramidites with coupling kinetics and coupling efficiencies comparable to those of deoxyribonucleoside phosphoramidites led to an assessment of 2'-O-(4-nitrogenated benzyloxy)methyl groups through solid-phase RNA synthesis using phosphoramidites 2a-d, 12a, and 14a. These phosphoramidites exhibited rapid and efficient coupling properties. Particularly noteworthy is the cleavage of the 2'-O-[4-(N-methylamino)benzyloxy]methyl groups in 0.1 M AcOH, which led to U19dT within 15 min at 90 degrees C. [reaction: see text]     

Nucleoside-metallacarborane conjugates for base-specific metal labeling of DNA

A general approach to the synthesis of nucleoside conjugates between derivatives of thymidine (T), 2'-O-deoxycytidine (dC), 2'-O-deoxyadenosine (dA), and 2'-O-deoxyguanosine (dG), and metallacarborane complexes is described. Metallacarborane-nucleoside derivatives are prepared by reaction of the dioxane-metallacarborane adduct with a base-activated 3',5'-protected nucleoside. In the case of T and dG a mixture of regioisomers, which is easily separable by chromatographic methods, is obtained, thus yielding a series of modifications containing metallacarborane groups at the 2-O, 3-N, 4-O and 1-N, 2-N, 6-O locations, respectively; dC and dA are alkylated at the exo-amino function. The proposed methodology provides a route for the synthesis and study of nucleic acids modified with metallacarboranes at designated locations and a versatile approach to the incorporation of metals into DNA.