s. h. hasanzadeh

Electromyographic (EMG) signals obtained from a contracted muscle contain valuable information on its activity and health status. Much of this information lies in motor unit potentials (MUPs) of its motor units (MUs), collected during the muscle contraction. Hence, accurate estimation of a MUP template for each MU is crucial.

To investigate the possibility of improving MUP template estimation using the wavelet denoising technique.

In this analytical study, several MUP template estimators were developed by combining conventional estimation methods and wavelet denoising techniques. A MUP template was initially estimated using conventional methods such as mean, median, median-trimmed mean, or mode. Thereafter, it was post-processed using the wavelet denoising technique.

Evaluation results of the studied estimators using 40 simulated EMG signals with a true template for each constituent MUP train showed that augmented wavelet- based template estimation methods are more reliable than conventional methods. However, on average, wavelet denoising was not much effective. Around 40 MUPs of a MU is sufficient to estimate its MUP template.

Although wavelet techniques are effective in EMG signal analysis, here wavelet denoising did not practically improve MUP template estimation. Considering computational simplicity and estimation error, the two methods median and median-trimmed mean are practical estimators that can provide a good estimation of a MUP template for a MU when approximately 40 MUPs are available. Nevertheless, the baseline noise level in the MUP templates estimated using the median-trimmed mean method is slightly lower than that in the templates estimated using the median method.

The aim of this study was to determine the predictability of the PLS-SEM model for injuries resulting in hospitalization in motorcyclists using a mediator variable in a case-control study.
 

In this case-control study, 300 cases and 156 controls were randomly selected from 150 clusters using random cluster sampling. The data were collected using the motorcycle riding behavior (MRB) questionnaire, adult attention deficit hyperactivity disorder (ADHD) questionnaire (subscales) and a checklist containing motorcycle related variables.
 

The motorcycle riding behavior, adult ADHD, motorcycling related variables and some demographic variables were found to be the predictors of injury. There were significant positive relationships between injury and motorcycling related variables (B=0.20, P=0.001) and ADHD (B=0.33, P=0.001), between MRB and motorcycling related variables (B=0.51, P=0.001) and ADHD (B=0.52, P=0.001), and between ADHD and motorcycling related variables (B=0.39, P=0.001).
 

Considering the more accurate results of PLS-SEM, the intervention programs should especially address those who have hyperactive children, those who use the cellphone while riding, and those who ride in dark hours of the night.

Parasitic infections have got on importance in Iran and is considered as one of the health problems in our society. Upgrading hygienic level in different rural and urban centers, decreased its prevalence. This study tries to in investigate the frequency and number of infectious and noninfectious intestinal parasites. The patients characteristics were filed in the laboratory in special notebooks. Then all of the stool samples were investigated by direct observations Formalin ‑ ether concentration method and by staining. The results were referred to the physician. To all of the 1788 patients referring to Ghods clinic, 182 patients were infected by parasites. Form all the positive cases, 92.85 % were infected by protozoan parasites whereas 7.14% were infected by helminthic parasites. Giardia by 59% was the most prevalent. The percent of the parasitic infections were as following. Entamoeba histolytica (1.65%), Entamoba coli (21.97%), (Chilmastix mesili (7.69%) Lodamoeba butschlii (1.09%), Blastoeystis hominis (0.55%), Trichomonas hominis (0.55%), Taenia saginata (0.55%), Hymenolepis nana (1.65%), Ascaris lumbricoides (0.55%), Oxyuris (4.39%). Parasitic infection is one of the important hygienic factors in every society. As its frequency differs in different times and places, so its periodical investigation is quite necessary, This study showed that parasitic infections reduced during recent years but it also showed that Giardia has got the highest rank among all other parasites.