Background and Aim: Measuring the outcome of chronic diseases such as Multiple sclerosis is an important factor in assessment of disease impact on different dimensions of quality of life and in evaluation of therapeutic interventions. The aim of this study was to perform the cross-cultural adaptation of the MSIS-29 which is a MS-specific outcome measure for Iranian patients.Materials and methods: The Iranian adaptation process of the MSIS-29 included 5 steps. To evaluate psychometric properties of the translated version, the questionnaire was administered to a consecutive sample of 96 patients with clinically definite MS referred to our out-patient clinic. Test-retest reliability was assessed in a sub-sample consisted of 30 patients. These patients completed the questionnaire on two occasions separated by a 7-day interval. The Iranian version of the SF-36 was also administered to this sub-sample in order to evaluate the validity of translated MSIS-29.Results: Statistical analysis indicated that the Persian version of the MSIS-29 had high internal consistency (cronbach's alpha coefficients> 0.70) and test-retest reliability (intra-class correlation coefficients >0.70) and a good validity.Conclusion: The Persian version of the MSIS-29 is a reliable and valid instrument for measuring MS outcome in Iranian patients. It can be used in clinical trials and cross-sectional studies.

In this paper, first, the equations of motion for a rectangular isotropic plate have been derived. This derivation is based on the Von Karmarn theory and the effects of shear deformation have been considered. Introducing an Airy stress function, the equations of motion have been transformed to a nonlinear coupled equation. Using the Galerkin method, this equation has been separated into position and time functions. By means of the dimensional analysis, it is shown that the orders of magnitude for nonlinear terms are very small, with respect to linear terms. Then, for the first time, the invariant manifold theory has been applied to the plate problem and it is proved that the nonlinearities are stiffness and inertia types. Finally, the Multiple scale method is applied to the equations of motion and closed-form relations for the nonlinear natural frequencies and mode shapes of the plate are derived. The obtained results are in good agreement in comparison with numerical methods. Using the obtained relation, the effects of initial displacement, thickness and dimensions of the plate on nonlinear natural frequencies and displacements have been investigated. These results are valid for a special range of the ratio of thickness to dimensions of the plate, which is a characteristic of the Multiple scale method.

The current research aims to carry out a multi-timescale variability analysis for the time series of sunspots (SN), precipitation (Pr), and maximum temperature (Tmax) in four main stations in the western area of Iran. In addition, the emphasis is on the impact of the decadal solar cycle on the variability of climatic quantities. Appropriate statistical methods were employed to investigate the relationships between reconstructed time series. The results demonstrated that the more intense intra-annual to inter-annual fluctuations of the SN signal are synchronized with the peak of the decadal component of sunspots. For the monthly precipitation, the deviation from the regular yearly pattern is markedly related to intense intra-annual variations in comparison to the inter-annual plus decadal variations. While the dominant mode of variability of the SN, which contains 89% of the variance, occurs at low frequencies according to cumulative spectral power (CSP), the contribution of this band in the variability is less than 10% for the Pr and is trivial for the Tmax. The result of wavelet coherence (WTC) analysis indicates a close connection between the variability of Tmax and Pr at different timescales over the region, except for the 32-128-month scale, which is free of significant common oscillations. Furthermore, a signature of a significant decadal fluctuation was also observed between Tmax and Pr which shows a completely different phase relationship for this timescale when compared to all smaller scales.

One important issue in drought studies is realizing the spatial pattern of drought events in a region through point estimation of the drought characteristics. In the first section of this research, in order to investigate the effect of probability distribution function transformation embedded in SPI, on the spatial distribution of drought, regional analysis was carried out using precipitation and SPI data, separately. The case study is the Anzali wetland watershed in the north of Iran. The results in terms of the employed regional analysis method and time scale were different. The results showed that by decreasing the time scales to less than 1 year, while by the SPI index the region was completely homogeneous, the region was divided into different sub-regions using precipitation. The important conclusion drawn from this part of the research was the necessity of zoning the region via precipitation and then analyzing drought in the obtained regions. In the second part of the research, a comparison was made among three zoning methods including; L-moment, hierarchical and non-hierarchical clustering methods using precipitation and SPI, separately. Overall, L-moment was more successful than the other two clustering methods in detecting homogeneous regions in the study area. Finally, it was concluded that reducing events time scales sharpened the difference between the zoning methods; therefore, choosing an appropriate zoning method would be more important in monthly and seasonal time resolutions.

Nonlinear vibration analysis of the reaction wheel based on rotating shaft/disk model with elastic bearings which subjected to temperature changes is investigated. The rotating shaft has been modeled by the Timoshenko beam theory and elastic bearing model consists of a nonlinear spring and linear damping characteristics. Gyroscopic effects and disk imbalance forces, as well as the couplings associated with the shear deformation have been considered in the equation of motion. Temperature changes (increase or decrease) is appeared in system as an axially load when the supports of the rotor do not allow the shaft to move in axial direction. The method of Multiple scales has been applied directly to solve nonlinear mathematical model and hence obtain the nonlinear dynamic response of the rotor system. Numerical simulations are based on a real reaction wheel parameters. The resonant curves have been plotted in time and frequency domain and discussed w/wo temperature changes. It has been shown that temperature changes significantly affects the dynamic behavior of the rotor system leading to resonant hard spring type curves.

Introduction: For evidence based decision-making and designing more accurate health system planes for effective prevention on drug dependency, incidence rate and time trend of number of new cases are necessary. This survey was conducted based on data of Kerman drug detoxification agencies in order to determine the time trend of incidence rate of opioid dependency and the effects of various factors on lag time (the time between onset of substance use and first treatment request). method: In this retrospective cohort study, 4309 opioid users visiting Kerman Welfare Organization between 1997 and 2004 were analyzed. Subgroups were shaped according to the first year of consumption. Estimated incidence of addiction was determined by using backward calculation method. The Effect of various factors on lag time was calculated by multivariable regression method. Results: Relative incidence of addiction between 1997 and 1999 was increased by 70% annually, followed by a slightly decrease to 540 persons in 2000. The minimum estimated number was seen in 2003 (400 cases) and it peaked to the maximum in the next year (1145 cases). The average of lag time was 7.98±6.47 years with median 6 years. The lag time of opium users was 7.81±6.48 and for opium syrup – a liquid prepared from the ashes of smoked opium – users was 8.32±6.17 years (p=0.001). Individuals who have consumed both opium and opium syrup simultaneously, had a more lag (p=0.0001). Men with lag time of 8.1±6.41 years, had a significant longer lag time than women (7.05± 6.78 years).In compare with cases with 20-30 ages (7.86±6.38 years) and cases older than 30 years (7.7±6.44 years), the lag time for persons less than 20 years old (8.62± 6.68 years) was significantly more (p=0.0001). The lag time for illiterates (10.73±7.59 years) was more than cases with academic education (7.87±7.27 years). The lag time for married persons (8.87±6.8 years) was significantly more than singles (4.9±3.76 years). Conclusion: time trend of addiction can be divided into two parts in recent years. First part is from 1997 to 1999; in this period the number of new cases of addiction increased but from 2000 to 2002 it is fairly constant. Some factors such as being women, younger, more literate, single and simply opium users have a negative correlation with lag time.