Mechanism of universal conductance fluctuations.

Universal conductance fluctuations are usually observed in the form of aperiodic oscillations in the magnetoresistance of thin wires as a function of the magnetic field B. If such oscillations are completely random at scales exceeding ξ B , their Fourier analysis should reveal a white noise spectrum at frequencies below [Formula: see text]. Comparison with the results for 1D systems suggests another scenario: according to it, such oscillations are due to the superposition of incommensurate harmonics and their spectrum should contain discrete frequencies. An accurate Fourier analysis of the classical experiment by Washburn and Webb reveals a purely discrete spectrum in agreement with the latter scenario. However, this spectrum is close in shape to the discrete white noise spectrum whose properties are similar to a continuous one.

[The modelling of dynamic ascariasis infectivity and prevalence in foci of invasion]. / Modelirovanie dinamiki zarazhaemosti i porazhennosti askaridozom v ochagakh invazii.

Suggests a simple model for calculation of ascariasis invasion rate in the population living in temperate climate foci, based on a single copro-ovoscopic examination over the entire epidemic season or a certain period. Describes a method for model construction for various epidemic conditions and a computer program realizing this method. The model is applicable for operative assessment of current ascariasis infection rate and for planning preventive measures.

[The determination of the upper limits of year-round morbidity]. / Opredelenie verkhnikh predelov kruglogodichnoi zabolevaemosti.

The use of K. Pearson's criterion has made it possible to establish that the empirical rows presenting the annual data on dysentery morbidity for each month during the period of many years correspond to binomial distribution. For this reason, the calculation of the highest limit of annual morbidity for many years should be made with the use of the formulae of great radices of quadratic inequation [formula: see text] used in mathematical statistics for the determination of the highest limits in binomial distribution. For the number of observations (n) not the number of inhabitants (which contradicts to the notion of observation in the theory of probability), but the number of minimal values of monthly morbidity, used for the calculation of the minimal average morbidity value omega or theta*, should be taken. To obtain objective results, the minimal average value omega or theta* and the ratio t2/2n must be of the same order, where t is the critical value of Student's criterion equal to 1.96.

[A computer model of "sense of humor". II. Realization in neuronal nets]. / Komp'iuternaia model' "chuvstva iumora". II. Realizatsiia v neironnykh setiakh.

The Hopfield model of neural networks can be adapted for solving the "linguistic problems", i.e. the processing of a continuous succession of polysemantic images. The realization of "a sense of humor" in such a model is possible.

[A computer model of "sense of humor". I. General algorithm]. / Komp'iuternaia model' "chubstva iumora".I. Obshchii algoritm.

A computer model of "a sense of humor" is formulated. The humorous effect is treated as a specific malfunction in the processing of information conditioned by the necessity of a quick deletion from consciousness of a false version. The biological function of a sense of humor consists in quickening the transmission of processed information into consciousness and in a more effective use of brain resources.

[The definition of the forms of the epidemic process in intestinal infections]. / Opredelenie form épidemicheskogo protsessa pri kishechnykh infektsiiakh.

A method for the identification of the forms of the epidemic process in dysentery (annual, seasonal and outbreak forms) has been worked out. The method is based on the calculation of the upper limits of annual and seasonal morbidity from the data on the period of several years with the use of the formulae of binomial distribution, serving as the mathematical model of alternative random values, such as morbidity. The comparison of actual morbidity for each year of the analyzed period with the upper limits of annual and seasonal morbidity helps identify the form of the epidemic process.

[Methodological approaches to the analysis of morbidity with temporary loss of work capacity]. / Metodicheskie podkhody k analizu zabolevaemosti s vremennoi utratoi trudosposobnosti.

The morbidity with temporary disablement (MTD) was studied with the help of Pearson's [correction of Pirson's] criterion in 689 empiric rows. The effect of work conditions on such morbidity was scored by dispersion analysis, demanding to take into account not only intergroup parameters connected with work conditions, but also intragroup ones, depending on casual circumstances, that is why the results should be regarded as preliminary data. The estimated effect of work conditions on the MTD shows unjustified high results for the year, because intragroup parameters were levelled.

[Evaluation of the methods of quantitative assessment of the effect of working conditions on morbidity with temporary disability]. / Otsenka metodov kolichestvennogo opredeleniia vliianiia uslovii truda na zabolevaemost' s vremennoi utratoi trudosposobnosti.

For the first time it is proposed to use the method of assessing the etiological risk for the quantitative determination of working conditions impact on morbidity associated with temporary disability. A comparison was made of indicators of working conditions impact on morbidity associated with temporary disability with the help of a single-factor dispersion analysis and by calculating etiological risk on the basis of the same background information--monthly morbidity associated with temporary disability among workshop workers and a control group: the results were the same. But the calculation of etiological risk is more simple.

[Epidemiological analysis of hepatitis A morbidity]. / Epidemiologicheskii analiz zabolevaemosti gepatitom A.

A retrospective epidemiological analysis of hepatitis A morbidity for many years among the population of two neighboring towns in the temperate climatic zone of the USSR has revealed the cyclic character of the epidemic process without a perceptible decrease in its extensiveness and has determined the high-risk groups, as well as the beginning of the seasonal rise of morbidity in these groups. The results of the study indicate that different levels of hepatitis A morbidity and risk groups can be observed in these two neighboring towns. At periods of a lower morbidity level the high-risk group embraces schoolchildren, and when morbidity is at a higher level the risk group includes schoolchildren and preschool children in organized groups. Among the latter the morbidity level is influenced by factors acting all the year round and among school children, by seasonal factors. The beginning of the seasonal rise of morbidity falls on August, while in organized groups of children of preschool age the seasonal rise of hepatitis A morbidity begins 1-1.5 months later. All prophylactic measures for controlling hepatitis A should be carried out with due regard to these features of the epidemic process.

High incidence of migration inhibition reactivity to lung tumor-associated antigen by normal donors in close contact with lung cancer patients or materials.

A high incidence of indirect leukocyte migration inhibition reactivity of normal donors to a 3-M KCl extract from a fresh pleural effusion of a patient with a lung adenocarcinoma (designated 7661) was observed. When these normal donors were classified according to contact with lung cancer patients or materials, 22 of 32 (72%) normal donors in contact with lung cancer patients or materials were reactive with the 7661 extract as compared to only 3 of 76 (4%) who had no contact. Of normal donors involved in the direct care of lung cancer patients, 14 of 20 (70%) were positive, whereas only 2 of 10 (20%) hospital personnel who worked with noncancer patients were reactive. Among laboratory personnel who handled blood and tissue specimens from lung cancer patients, 8 of 11 (73%) were positive with the 7661 extract, whereas none of 5 laboratory workers who worked with cancer materials unrelated to lung cancer were positive. Also, none of 13 personnel working in laboratories adjacent to those where lung cancer tests were performed were reactive with 7661. None of the 16 blood bank donors and none of 11 secretarial and clerical staff who worked in biochemical laboratories were positive. Reactivity was no correlated with a smoking history. Thus development of reactivity appeared to require direct contact with lung cancer patients or materials. The results suggested a horizontal transmission of reactivity against an antigen associated with lung cancer.