Decision of mathematical logical tasks in sensory enriched environment (classical music)

The time of a decision of mathematical logical tasks (MLT) was decreased during classical musical accompaniment (power 35 and 65 dB). Music 85 dB did not influence on the process of decision of MLT. Decision without the musical accompaniment led to increasing of coherent function values in beta1, beta2, gamma frequency ranges in EEG of occipital areas with prevalence in a left hemisphere. A coherence of potentials was decreased in EEG of frontal cortex. Music decreasing of making-decision time enhanced left-sided EEG asymmetry The intrahemispheric and the interhemispheric coherences of frontal cortex were increased during the decision of MLT accompanied by music. Using of musical accompaniment 85 dB produced a right-side asymmetry in EEG and formed a focus of coherent connections in EEG of temporal area of a right hemisphere.     

EEG in mathematical logical problem solving

The model of mathematical logic tasks was developed at which decision there was a value coherence in delta-range raised. In low-frequency ranges (delta, theta, and alpha) a coherence of potentials of frontal cortex were increased. In high-frequency ranges (beta1, beta2, gamma) in frontal cortex coherence was decreased, and its increasing in central, parietal, temporal, and occipital areas with prevalence in the left hemisphere. Most changes of quantity of positive connections observed in value diagonal coherence. Analysis of spectral power EEG has shown, that at the decision of tasks there is a generalised raising on a cortex in delta-range. Theta-activity increased in a frontal cortex, and gamma band was raised in occipital areas. A spectral power in an alpha range mainly decreased.     

Corvidae are able to understand the logical structure in string-pulling tasks

The ability of the Corvidae to understand the logical structure in string-pulling tasks was studied in a set of experiments with varied position of strings. It was demonstrated that some hooded crows (Corvus cornix L.) and common ravens (Corvus corax L.) successfully completed the tasks where the strings were not intersected but placed so that the bait was positioned opposite the forepart of the empty string. Hooded crows also solved the task where the baits were attached to both strings, but one of the strings was disrupted. The task with two intersected strings where the bait was positioned opposite the forepart of the empty string was not solved by the crows. The results suggest the ability of both examined species to grasp the logical structure of such kind of tasks.     

Informational properties of neural nets performing algorithmic and logical tasks

It is argued that the genetic information necessary to encode an algorithmic neural processor tutoring an otherwise randomly connected biological neural net is represented by the entropy of the analogous minimal Turing machine. Such a near-minimal machine is constructed performing the whole range of bivalent propositional logic in variables. Neural nets computing the same task are presented; their informational entropy can be gauged with reference to the analogous Turing machine. It is also shown that nets with one hidden layer can be trained to perform algorithms solving propositional logic by error back-propagation. Received: 30 June 1995 / Accepted in revised form: 9 January 1996     

Influence of music on heart rate variability and comfort--a consideration through comparison of music and noise

By considering three kinds of music and noise, this research investigates the influence of music on the living body by comparing the difference of influence on heart rate variability and comfort when subjects listen to music and are exposed to noise. We used two pieces of classical music, rock music, and noise recorded by a tape recorder. The following conclusions were made from the findings of the research: 1) Hearing classical music results in a small variance of Mayer Wave related Sinus Arrhythmia (MWSA) component and Respiratory Sinus Arrhythmia (RSA) component compared with a body being at rest. This is because the sympathetic nerve is suppressed by the sound of classical music. With rock music and noise, however, the MWSA component increases and the RSA component decreases. 2) From a psychological evaluation, we found that classical music tends to cause comfort and rock music and noise tend to cause discomfort. 3) A correlation was found between the balance of the MWSA component and the RSA component and the psychological evaluation. As the comfort increases, the variance of MWSA decreases; as discomfort increases, the variance of MWSA increases.     

On the solution of mathematical models of herd immunity in human helminth infections

The general solution of the mathematical model of herd immunity to human helminth infections recently proposed by Anderson and May [3] is obtained. The numerical solution of a more accurate biological model is indistinguishable from the corresponding exact solution of a more tractable mathematical model. Computer simulations of some particular cases of this model support the notion that both ecological and immunological factors determine the observed convex patterns of age-prevalence and age-intensity curves of human helminth infections.This work was made thanks to the advise and support of Dr. Robert M. May while the author was Postdoctoral Fellow at Princeton University     

Influence of viscosity on myocardium mechanical activity: a mathematical model

We have previously proposed and validated a mathematical model of myocardium contraction-relaxation cycle based on current knowledge of regulatory role of Ca2+ and cross-bridge kinetics in cardiac cell. That model did not include viscous elements. Here we propose a modification of the model, in which two viscous elements are added, one in parallel to the contractile element, and one more in parallel to the series elastic element. The modified model allowed us to simulate and explain some subtle experimental data on relaxation velocity in isotonic twitches and on a mismatch between the time course of sarcomere shortening/lengthening and the time course of active force generation in isometric twitches. Model results were compared with experimental data obtained from 28 rat LV papillary muscles contracting and relaxing against various loads. Additional model analysis suggested contribution of viscosity to main inotropic and lusitropic characteristics of myocardium performance.     

Influence of anions on the properties of microbial polysaccharides in solution

The order-disorder transition temperatures of the polysaccharides succinoglycan and xanthan are strongly influenced by the salts present in solution. High concentrations of anions such as bromide or thiocyanate lower the transition temperature, thus decreasing the stability of the polymer and increasing its susceptibility to acid catalysed degradation. Salts such as sulphate and phosphate raise the transition temperature but can cause precipitation, and result in the incompatibility of the polymers with certain brines. The effects are in line with the Hofmeister or lyotropic series. The two polysaccharides seem to fit into a spectrum including other biopolymers such as some proteins, although not DNA even though its behaviour is qualitatively similar. The effects arise from the interaction of the salts, primarily the anions, with the solvent water. The hydropholic nature of carbohydrates enables them to structure the solvent to a higher temperature than proteins. The importance of the effect of the polymer on the solvent in considering structure-property relationships cannot the overstressed.     

Influence of the pyruvate content of xanthan on macromolecular association in solution

The unusual increase in viscosity and pseudoplasticity often observed when salts are added to moderately concentrated aqueous solutions of xanthan gum is shown to arise from an increase in the extent of macromolecular association. The fractional change in viscosity on addition of KCl to salt-free 1% (w/v) solutions of purified polysaccharide in the K⁺ salt form is found to be positive only when the degree of pyruvate substitution (fraction of side chains which carry pyruvate ketal substituents) exceeds ≈0.31. Above this value, the fractional change in viscosity increases with further increase in the degree of pyruvate substitution. These differences cannot arise from different degrees of conformational ordering, since the magnitude of the thermally induced order disorder transition (monitored by optical rotation at low ionic strength) is independent of pyruvate content. The temperature at the transition midpoint, however, falls with increasing degree of pyruvate substitution. This is attributed to destabilization of the ordered structure by intramolecular electrostatic repulsion between pyruvate groups, and stabilization through apolar interactions of acetate methyl groups. Viscosity-concentration relationships show changes of slope which mark the onset of macromolecular association. Association commences at lower concentrations when ionic strength and degree of pyruvate substitution are high. It is suggested that once electrostatic repulsions have been diminished at high ionic strength, association is promoted by intermolecular apolar interactions of pyruvate methyl groups, which are suitably near the periphery of the helical conformation.     

Influence of the base sequence on the conformational behaviour of DNA polynucleotides in solution

NMR studies were carried out on samples of the non-self-complementary tetramers d(C-A-C-A), d(T-G-T-G), d(G-A-G-A) and d(T-C-T-C) and of 1:1 mixtures of the complementary tetramers d(C-A-C-A) X d(T-G-T-G) and d(G-A-G-A) X d(T-C-T-C) at two DNA concentrations and of the self-complementary octamers d(C-A-C-A-T-G-T-G) and d(G-A-G-A-T-C-T-C). Assignments, based upon one-dimensional NOE and homonuclear-decoupling and two-dimensional correlated and NOE spectroscopies are given of the resonances of most of the base and sugar protons. Chemical shift vs temperature profiles, constructed for all samples, yielded insight into the temperature- and concentration-dependent conformational behaviour of the compounds and were used to obtain thermodynamic parameters pertaining to the stacked-single-strand----random-coil and duplex----random-coil equilibria. Vicinal proton-proton couplings were analyzed in terms of the conformation of the deoxyribose rings in the single-stranded tetramers and duplexed octamers. The NOE patterns, chemical shift profiles, imino-proton resonances and coupling data revealed that the compounds adopt B-DNA-like structures. The ratio duplexed/stacked-single-strand/random coil depends upon external conditions as well as upon base sequence. The thermodynamic data indicate that: in terms of single-helical stacking, the R-R steps (Tm 321-328 K) appear more stable than the Y-R or R-Y steps (Tm 308-316 K) and the Y-Y steps score least (Tm 290-300 K), and the duplexes consisting of alternating, d(Y-R)n, strands are more stable, in terms of delta H degrees, compared to the d(R-R)n X d(Y-Y)n duplexes. The analyses of the couplings demonstrated that the sugars of the single-stranded tetramers and duplexed octamers occur as a blend of N- and S-type conformers, with a preference for the S-type (C2'-endo) sugar conformation: upon duplex formation, no significant shift in the N-type/S-type ratio was observed. The fraction S-type sugar conformation of a given residue, %S, in the stacked-single strands was found to depend upon the nature of its own base and that of the adjacent residues: sugars in an R-R stretch display high values of %S (90-100), whereas those in Y-Y stretches show relatively low values (approximately equal to 65).(ABSTRACT TRUNCATED AT 400 WORDS)     

Influence of acetyl and pyruvate substituents on the solution properties of xanthan polysaccharide

Xanthan, an exocellular polysaccharide produced by the plant pathogenic bacterium Xanthomonas campestris has been the subject of considerable interest in recent years because of its unusual rheological properties in solution ('weak gel') and consequent range of applications. The polymer consists of a cellulosic backbone with trisaccharide side chains linked to alternate backbone residues; acetyl and pyruvate substituents are carried in variable amounts on these side chains. In this study a series of xanthans differing in the percentage of substituent groups and in molecular weight range have been prepared by culturing a variety of different strains of X. campestris. All of the xanthans have been characterized by a range of physicochemical techniques. In particular, the intrinsic viscosities at low shear rates, and at a range of ionic strengths, have been determined and the geometric persistence lengths evaluated by the Smidsr?d-Haug method. Intensity light scattering measurements have been made using the procedure of Coviello and co-workers to promote molecular dispersion. Despite significant differences in the acetyl and pyruvate contents, the molecular weight vs mean square radius behaviour of our samples did not differ substantially from each other or from those reported for other xanthan samples in the literature. The persistence length, determined by the method of Schmidt et al. (120 +/- 8 nm) was also, within experimental error, the same for all the samples measured. These values differed considerably from those calculated from the ionic strength dependence of intrinsic viscosity (the Smidsr?d-Haug method) was reported by Tinland and Rinaudo and calculated for our samples.(ABSTRACT TRUNCATED AT 250 WORDS)     

The problem of determining the affinity of bivalent antibodies using ELISA and its mathematical solution]

A new approach for the determination of the affinity of monovalent receptors in direct coordinates could be obtained without using Klotz or Scatchard equations. The mathematical solution of the problem of the determination of the affinity of bivalent antibodies by ELISA gives the following relation between absorbance, measured in ELISA. and antigen concentration: omega + square root of omega 2 + omega = liK, where omega = (Ao-Ai)/Ai, Ai is the absorbance, if Ag concentration is equal li; Ao is the absorbance, if Ag concentration is equal zero, K is an equilibrium constant.     

Influence of soil solution aluminum on root elongation of wheat seedlings

Wheat (Triticum aestivum L.) seedlings were grown for 4 days in an acid soil horizon treated with 10 levels each of Ca(OH)₂, CaSO₄ and CaCl₂. The treatments resulted in a wide range of Al levels and Al speciation in soil solution. Seedling root length in the Ca(OH)₂ treatments was significantly related (p<0.01) to calculated Al³⁺ activity in soil solution. The Al–SO₄ complex in soil solution had a negligible effect on the root growth of Hart wheat, thus confirming the previously reached conclusion concerning the nonphytotoxicity of Al–SO₄. The short-term seedling root growth technique used in this investigation allowed for separation of Al effects on root elongation from those on plant nutrition and should be useful for studying Al toxicity relationships in soil.     

Influence of the charge density on the solution behaviour of polycarboxylates derived from the polysaccharide scleroglucan

Solution properties of polycarboxylates obtained by periodate oxidation of scleroglucan, with different degrees of oxidation, have been studied as a function of pH. Viscosity, calorimetric, optical and chiro-optical measurements show that the two carboxylated samples with higher degrees of oxidation (S-1·0 and S-0·7) can assume an ordered conformation at low pH. On the contrary the sample characterized by a lower extent of oxidation (S-0·2) shows no conformational changes. Optical measurements suggest that this polymer would be in an ordered helical form in dilute aqueous solution.     

Extending the scope of the controlled logical clock

Event traces are helpful in understanding the performance behavior of parallel applications since they allow the in-depth analysis of communication and synchronization patterns. However, the absence of synchronized clocks on most cluster systems may render the analysis ineffective because inaccurate relative event timings may misrepresent the logical event order and lead to errors when quantifying the impact of certain behaviors or confuse the users of time-line visualization tools by showing messages flowing backward in time. In our earlier work, we have developed a scalable algorithm called the controlled logical clock that eliminates inconsistent inter-process timings postmortem in traces of pure MPI applications, potentially running on large processor configurations. In this paper, we first demonstrate that our algorithm also proves beneficial in computational grids, where a single application is executed using the combined computational power of several geographically dispersed clusters. Second, we present an extended version of the algorithm that—in addition to message-passing event semantics—also preserves and restores shared-memory event semantics, enabling the correction of traces from hybrid applications.