Electrical resistivity and conductivity results in the important concept of "quasineutrality", which says the density of negative charges is approximately equal to the density of positive charges over large volumes of the plasma ("n" = <Z>"n"), but on the scale of the Debye length there can be charge imbalance. In the special case that "double layers" are formed, the charge separation can extend some tens of Debye lengths. The magnitude of the potentials and electric fields must be determined by means other than simply finding the net charge density. A common example is to assume that the electrons satisfy the Boltzmann relation: Differentiating this
Negative and positive rights by the Czech jurist Karel Vasak, may include other civil and political rights such as police protection of person and property and the right to counsel, as well as economic, social and cultural rights such as food, housing, public education, employment, national security, military, health care, social security, internet access, and a minimum standard of living. In the "three generations" account of human rights, negative rights are often associated with the first generation of rights, while positive rights are associated with the second and third generations. Some philosophers (see criticisms) disagree that the negative-positive rights distinction is useful or valid.