More than 90 years ago Robinson [1], after summarizing more than two centuries of research, defined the diverse natural functions of the peritoneum as follows: (a) to regulate fluid for nutrient and mechanical purposes; (b) to facilitate motion; (c) to minimize friction, and (d) to conduct vessels and nerves to the viscera.

Numerical schemes for the calculation of photolysis rates are usually employed in simulations of stratospheric chemistry. Here, we present an improvement of the treatment of the diffuse actinic flux in a widely used stratospheric photolysis scheme (Lary and Pyle, 1991). We discuss both the consequences of this improvement and the correction of an error present in earlier applications of this scheme on the calculation of stratospheric photolysis frequencies. The strongest impact of both changes to the scheme is for small solar zenith angles. The effect of the improved treatment of the diffuse flux is most pronounced in the lower stratosphere and in the troposphere. Overall, the change in the calculated photolysis frequencies in the region of interest in the stratosphere is below about 20%, although larger deviations are found for H₂O, O₂, NO, N₂O, and HCl.

The concentration of methane (CH₄), the most abundant organic trace gas in the atmosphere, has increased dramatically over the last few centuries, more than doubling its concentration. Increasing concentrations of methane are of special concern because of their effects on climate and atmospheric chemistry. On a per molecule basis, additional methane is much more effective as a greenhouse gas than additional CO₂. Methane is also important to both tropospheric and stratospheric chemistry. Here, we examine past trends in the concentration of methane, the sources and sinks affecting its growth rate, and the factors that could affect its growth rate in the future. This study also examines the current understanding of the effects of methane on atmospheric chemistry and climate.

This review is devoted to the theory of plasma equilibrium in conventional stellarators with a plane circular axis and helical magnetic fields. Its primary objectives are the analysis of the conditions of finite-pressure plasma equilibrium in stellarators and the search for ways of increasing the achievable β (ratio of kinetic to magnetic pressures).

Belgium is one of the oldest parliamentary democracies, but it is also one of the European societies which is most deeply divided along ethno-linguistic, religious-secular and socio-economic lines, and these conflicts have brought about many tensions in the political structure. In the wake of the world economic crisis strong fascist or quasi-fascist movements emerged which brought the political system close to collapse. How Belgium weathered the storm of the 1930s within a democratic framework is, therefore, of particular interest for other similar conflict-prone societies.