A Maximum of Temperature in the Middle Ionosphere
J. FUCHS1 has already pointed out the fact that from the change of electron-density (N) with height (h) conclusions as to the temperature in the ionosphere can be drawn. It was, however, not possible then to carry out exact calculations for two reasons: first, the electron-density was only known to be dependent on the apparent height (h′), and secondly, the process of electron loss was not known in more detail, so that Fuchs had to calculate with a recombination-coefficient constant as to space and time.
The role of bone marrow in the immune response.
Publisher Summary This chapter summarizes the various experimental findings related to the source and function of various immunocompetent cells to define the functions of these cell types with respect to the induction of the humoral and cell mediated immune responses. The chapter evaluates the role of the bone marrow as a source of and as an influence upon stem cells and immunocompetent cell precursors and presents a scheme of cellular interactions culminating in antibody formation that incorporate the findings of all investigations to date in a variety of animal species. The scheme presents the specific multicellular pathways composed of a number of specialized cells rather than the single cell pathway characterized by a single, pluripotential immunocompetent cell. Furthermore, it also appears to supply the microphages as well as the cells that constitute the cellular infiltrations in cell-mediated immune reactions. A better understanding of the immune processes and the cellular events and interactions that lead to the humoral and cell-mediated immune responses will greatly facilitate the comprehension of the etiology, pathogenesis, and management of the immune deficiency syndromes, autoimmune states, and related diseases and will hasten the evolution of more rational and scientifically based approaches to prevent the graft-versus-host reaction and the graft rejection by the host.
Eine einheitliche Formel für die morgendlicheF2-Ionisation an Europäischen Stationen
ZusammenfassungDie Frequenzquadrate (f0F2)2, die an europäischen Ionosphärenstationen in den Morgenstunden eines Sommermonats beobachtet wurden, können durch eine einheitliche Formel von der Gestalt
$$(f_0 F_2 )^2 = K.\left( {\frac{{\cos \chi }}{{cos^2 \varphi }}} \right)^x .cos^2 \varphi $$
 dargestellt werden. In dieser Formel bedeutet χ den Zenitwinkel der Sonne, ϕ die geographische Breite der betreffenden Station.x ist eine ortsabhängige Konstante, währendK ortsunabhängig ist und aller Wahrscheinlichkeit nach die Intensität der ionisierenden Sonnenstrahlung charakterisiert.SummaryThe squares of critical frequencies (f0F2)2 measured at European stations in the morning of a summer-month may be represented by a formula
$$(f_0 F_2 )^2 = K.\left( {\frac{{\cos \chi }}{{cos^2 \varphi }}} \right)^x .cos^2 \varphi .$$

Herein χ is the zenithangle of the sun, ϕ the geographical latitude of the ionospheric station.α depends on locality, butK is independent on it and probably characteristic of intensity of the sun's ionizing radiation.