A physical examination was used to screen for breast cancer in 2,500 women with biopsyproven adenocarcinoma of the breast and in 5,000 ages-and race matched control women.
The results of the physical examination were positive (i. e., a mass was palpated) in 1,800
cases and in control woman, all of whom showed no evidence of cancer at biopsy.
Calculate:
a. The positive predictive value
b. The negative predictive value

An 81-year-old man and avid reader had a mild stroke from which he eventually recovered. he did have some residual signs and symptoms, however, such as: - right-sided homonymous hemianopia (i.e. loss of vision on the right half of the visual field in each eye) - alexia ("dyslexia"), the inability to read, which greatly frustrated this man - loss of sensation on the skin on the right side of the body why was this man unable to see the right half of his field of vision?

Which of these is likely to be the best source of valid health information?

Viral infections in plants ) can be controlled with antibioticsb) can spread within a plant via plasmodesmata c) have little effect on plant growthd) are not spread by animals