sleep deprivation is a condition of not having enough sleep it can be either chronic or acute. a chronic sleep-restricted state can cause fatigue. fatigue is a subjective state related to sleep deprivation, the more someone is deprived of sleep the more likely that person is to be fatigued. several studies indicated that drowsiness/fatigue can affect steering performance and speed control. rese...

conclusions orem’s self-care model is significantly effective in reducing the fatigue of multiple sclerosis patients. objectives to determining the effect of orem’s self-care model on fatigue in multiple sclerosis patients. patients and methods this research involved a clinical trial. sixty-three multiple sclerosis patients at the vice-chancellor in treatment affairs of yasuj university of medi...

aims: the performance of the vision system as the most important sense of the body depends largely on the optimum lighting of an environment. it is one of the factors that lead to vision problems such as visual fatigue of employees. this study aimed to assess the local lighting and visual fatigue among the official staff of an automotive industry development and research center which was conduc...

The oldest rocks which have been found so far (on the Earth) date to about 3.8 to 3.9 billion years ago (by several radiometric dating methods). Some of these rocks are sedimentary, and include minerals which are themselves as old as 4.1 to 4.2 billion years. Rocks of this age are relatively rare, however rocks that are at least 3.5 billion years in age have been found on North America, Greenla...

O'Neil et al. (Reports, 26 September 2008, p. 1828) presented neodymium-142 data for rocks from northern Quebec, Canada, and suggested that these rocks may represent the oldest preserved crustal section on Earth. We argue that the age of the rocks is based on a spurious correlation between rocks that are probably not co-genetic and negative (142)Nd anomalies that may be the result of an analyti...