The comparative characteristics of the Salmonella serotypes rarely encountered in the Maritime Territory

The results of the comparative study of the phenotypical properties and the plasmid profile of 63 strains of salmonellae, belonging to 44 serotypes of groups B, C1, C2, C3, D, E1, E4, F. The study revealed that strains of different serotypes had their individual plasmid profile. Strains of the same serotype of salmonellae isolated from similar sources had an identical plasmid profile, while strains isolated from different sources differed in their plasmid profiles, though they might have a similar phenotype. Plasmid analysis was shown to be an effective method for the intraspecific typing of rarely isolated Salmonella serotypes and suitable for use as the basis of the microbiological monitoring of salmonellae.     

Ecological problems of the Amu Darya delta

Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 3, pp. 6–8, March, 1992.     

The stability of vitamin C in powdered mixes for beverages]

Factors influencing vitamin C stability in powder mixtures for beverages were studied and the main ways of its decomposition in products preserved in glass containers or paper packages covered with polymeric film were established. The phenomenon of vitamin C self-stabilization has been observed.     

Intervention practices in musculoskeletal disorder prevention: a critical literature review

Musculoskeletal disorders (MSDs) affect much of the workforce and remain a major form of occupational ill health. With a view to improving the efficacy of interventions, this review examined preventative actions relating to these disorders. A detailed analysis grid was used to classify the information contained in the 47 reviewed articles whose common aspect was to report actions carried out in the workplace that led to the implementation of changes to prevent MSDs. The analysis identified and characterized three major categories of intervention processes in MSD prevention: the complete type (n=17), the shortened type (n=16), and the turnkey type (n=14). These three groups of intervention processes were differentiated by their approaches and their contexts of application. The result was important differences in the changes implemented. Because of the variability in intervention processes and possible impacts on MSD prevention, a proposal to "delimit" these processes so as to improve their effectiveness is presented.     

Intervals in Space-Time: A. D. Alexandrov is 85

Reliable Computing -     

Error Estimation for Indirect Measurements: Interval Computation Problem Is (Slightly) Harder Than a Similar Probabilistic Computational Problem

One of main applications of interval computations is estimating errors of indirect measurements. A quantity y is measured indirectly if we measure some quantities xi related to y and then estimate y from the results of these measurements as by using a known relation f. Interval computations are used "to find the range of f(x1,...,xn) when xi are known to belong to intervals ," where i are guaranteed accuracies of direct measurements. It is known that the corresponding problem is intractable (NP-hard) even for polynomial functions f.In some real-life situations, we know the probabilities of different value of xi; usually, the errors xi - are independent Gaussian random variables with 0 average and known standard deviations i. For such situations, we can formulate a similar probabilistic problem: "given i, compute the standard deviation of f(x1,...,xn) ." It is reasonably easy to show that this problem is feasible for polynomial functions f. So, for polynomial f, this probabilistic computation problem is easier than the interval computation problem.It is not too much easier: Indeed, polynomials can be described as functions obtained from xi by applying addition, subtraction, and multiplication. A natural expansion is to add division, thus getting rational functions. We prove that for rational functions, the probabilistic computational problem (described above) is NP-hard.     

The interdiffusion in melts of tin-lead system of eutectic and near-eutectic composition

The method of gamma-raying of samples by a narrow beam of gamma radiation is used to measure the interdiffusion coefficients in melts of a tin-lead system, which contain 17.6, 26.1, 29.3, and 33.9 at.% Pb, at temperatures from 500 to 1000 K. The results are compared with literature data. It is found that the concentration dependence of diffusion coefficient exhibits no special features in the vicinity of eutectic composition.     

Interval + Image = Wavelet: For Image Processing under Interval Uncertainty,Wavelets Are Optimal

In computer and electronic manufacturing, it is very important to be able to automatically check whether the surface mounted devices (SMD) are correctly placed on the printed circuit boards. The inspection of these boards has to be done on a shop floor, where statistical characteristics of the noise vary so much that, in essence, we only have interval estimates for this noise.We show that under this interval uncertainty, the optimal image processing technique consists of using Haar wavelets. Wavelets indeed lead to much better results than previously used Fourier transform techniques.On a more fundamental level, our result is a step towards solving an important problem related to wavelets: that wavelet transforms often empirically work much better than other methods, but there are very few theoretical explanations of this efficiency. Our results shows that, probably, such a theoretical explanation can be obtained if we take interval uncertainty into consideration.