Yes, nosebleeds do tend to occur more often during pregnancy. Pregnancy can cause the blood vessels in your nose to expand, and your increased blood supply puts more pressure on those delicate vessels, causing them to rupture more easily. Although it's unpleasant and inconvenient, an occasional minor nosebleed is generally harmless.
The higher the energy of the gamma rays, the thicker the shielding made from the same shielding material is required. Materials for shielding gamma rays are typically measured by the thickness required to reduce the intensity of the gamma rays by one half (the half value layer or HVL).
Gamma wave. Not to be confused with gamma rays. A gamma wave is a pattern of neural oscillation in humans with a frequency between 25 and 100 Hz, though 40 Hz is typical. According to a popular theory, gamma waves may be implicated in creating the unity of conscious perception (the binding problem).