An apparatus and method for increasing Vitamin D content in mushrooms irradiates the mushroom for a duration of up to six seconds with one or more pulses of light with wavelengths in the range of about 200 to about 1000 nanometers. The valve system is configured to prevent or impede respiratory gases from flowing into the lungs for at least some time such that the intrathoracic pressure is less than atmospheric pressure. A first pillow is positioned underneath the person’s head, and a force is applied to the person’s arm in a direction generally toward the person’s feet. 2\xd710\u221211 cm2s\u22121cmHg\u22121 at room temperature for helium, hydrogen, oxygen, nitrogen, or air. The systems and methods combine two techniques: the use of multiple flexible processing elements, and a design in which each of the elements can carry out any part of the processing performed by the device, including without limitation the physical, MAC, link, network, transport, and presentation layer processing. Thus, the detector detects active transmission sources on the backup channel to determine whether the backup channel is occupied.