Prevalence of Panton-valentine gene in Staphylococcus aureus isolated from clinical samples and healthy carriers in Gorgan city, north of Iran

Aim. Staphylococcus aureus (S. aureus) is a nosocomial and community acquired pathogen. S. aureus is a pathogen that causes several types of disease from skin infections to systemic diseases that is because of having several virulence factors such as enzymes, toxins, superantigens and Panton-Valentine leukocidin (pvl). pvl is a bi-component leukotoxin that destroy PMNs and monocytes and causes furunculosis, abscesses and necrotizing soft tissue infections in patients without any risk factors for such infections. The goal of this study was determine the prevalence of pvl gene in S. aureus isolated from patients and healthy carriers in Gorgan city, north of Iran. Methods. One hundred seventy isolates of S. aureus, 95 from patients and 75 healthy carriers, were collected during one year. After identification and purification, DNA extraction was done by phenol-chloroform method. Amplification of pvl gene was done by specific primer and polymerase chain reaction method. Results. Among the 170 isolates of S. aureus, 20 contained pvl gene. The frequency of isolates contained pvl gene in MRSA and MSSA isolates were 21.6, 19.3, which was not statistically significant. The frequency of these genes was not related to age, sex and source of isolation from patients. Conclusion. The frequency of pvl gene in this region were much higher than expected. © Copyright 2016 Edizioni Minerva Medica

Analysis of Non-stationary Data for Heart-Rate Fluctuations in Terms of Drift and Diffusion Coefficients

We describe a method for analyzing the stochasticity in the non-stationary data for the beat-to-beat fluctuations in the heart rates of healthy subjects, as well as those with congestive heart failure. The method analyzes the returns time series of the data as a Markov process, and computes the Markov time scale, i.e., the time scale over which the data are a Markov process. We also construct an effective stochastic continuum equation for the return series. We show that the drift and diffusion coefficients, as well as the amplitude of the returns time series for healthy subjects are distinct from those with CHF. Thus, the method may potentially provide a diagnostic tool for distinguishing healthy subjects from those with congestive heart failure, as it can distinguish small differences between the data for the two classes of subjects in terms of well-defined and physically-motivated quantities.Comment: 6 pages, two columns, 6 figure

Rare diseases of the anterior segment of the eye: update on diagnosis and management

This special issue is focused on the current approaches used to identify and manage rare diseases of the anterior segment of the eye, which range from congenital to acquired disorders that are caused by ocular or systemic conditions and often have consequences that extend beyond the anterior segment of the eye

A Multi-Agent Architecture for Distributed Domain-Specific Information Integration

On both the public Internet and private Intranets, there is a vast amount of data available that is owned and maintained by different organizations, distributed all around the world. These data resources are rich and recent; however, information gathering and knowledge discovery from them, in a particular knowledge domain, confronts major difficulties. The objective of this article is to introduce an autonomous methodology to provide for domain-specific information gathering and integration from multiple distributed sources

Determination of the constants of damage models

AbstractDamage models are basic elements in numerical simulation materials failure in particular at high strain rates. Many damage models can be found in the literature. However, a few of them such as GNT (Gurson, Tvergaard and Needleman) and Johnson-Cook models have gained wide application in the simulations. The models involve a number of constants to be determined normally by experiment in which void development in the specimen must be considered. This is usually a hard task and the results are always questionable. In this investigation a combined experimental, numerical and optimization technique is employed for identification of the constants of Johnson-Cook material and damage model. The experiments are conducted at low to high strain rate regimes using standard testing devices such Instron and high rate apparatuses such as “Flying Wedge”. The experiments are simulated using the same specimen geometries and the apparatus. The simulations are carried out using the commercial codes, Ls-dyna. The differences between the deformed shapes of the specimens from the experiments and those predicted from the numerical simulations are taken as the objective function for optimization purposes. The optimum constants are obtained using generic algorithm