Contour line future weather patterns. Isobars are commonly used in television weather reporting. Isallobars are lines joining points of equal pressure change during a specific time interval. These can be divided into "anallobars", lines joining points of equal pressure increase during a specific time interval, and "katallobars", lines joining points of equal pressure decrease. In general, weather systems move along an axis joining high and low isallobaric centers. Isallobaric gradients are important components of the wind as they increase or decrease the geostrophic wind. An isopycnal is a line of constant density. An "isoheight" or "isohypse" is a line of constant geopotential
Equal pay for equal work effects, with trade unions sometimes promoting conservatism. However, following the Second World War, trade unions and the legislatures of industrialized countries gradually embraced the principle of equal pay for equal work; one example of this process is the UK's introduction of the Equal Pay Act 1970 in response both to the Treaty of Rome and the Ford sewing machinists strike of 1968. In recent years European trade unions have generally exerted pressure on states and employers for progress in this direction. In international human rights law, the statement on equal pay is the 1951 Equal Remuneration Convention, Convention 100 of