Bronfenbrenner's final level is the macrosystem, which is the largest and most remote set of people and things to a child but which still has a great influence over the child.
Term EMF is acronym for Electro-Motive-Force , that is a Force that Moves Electric Charge. It is not implied by the name of that term whether the origin of the Force is elecrostatic, magnetic , thermoelectric , or electrochemical.
UPF is a rating generally used for clothing and other fabrics that protect you from the sun. It measures the amount of UVA and UVB radiation that penetrates the fabric and reaches the skin. SPF stands for Sun Protection Factor. It is a rating for sunscreens or other cosmetic products containing sunscreen.