Simple motor reaction time (RT) to 100 percent negative contrast stimuli was measured for various background luminances as well as after bleaching a fraction of retinal photopigments. RT decreased to asymptotical value with the increase of background intensity. The intensity-dependent portion of RT behaved identically for 100 percent positive and negative contrast. Moreover, RT to 100 percent n...

acute infectious gastroenteritis is one of the most common infectious diseases of humans in the world. diarrheal disease still ranks very high as a major cause of illness and death especially in developing nations. this study has been carried out to investigate enteropathogenic bacteria isolated from 2517 specimens of patients with diarrhea. the results obtained are as follow: salmonella typhim...