Wahlbeteiligung im Lebensverlauf. A-P-K-Analysen für die Bundesrepublik Deutschland in der Zeit von 1953 bis 1987

Im vorliegenden Beitrag soll geklärt werden, ob der Wandel in der Beteiligung an Bundestagswahlen mit dem kohortenspezifischen Wahlverhalten politischer Generationen zusammenhängt, und welche Rolle dabei Alters- und Periodeneffekte spielen. Dabei steht auch die Frage zur Diskussion, ob es nach der Bundestagswahl im Jahre 1972 tatsächlich zu einem Rückgang der Wahlbeteiligung gekommen ist oder ob dieses Phänomen auf einem Artefakt der amtlichen Wahlstatistik beruht. Diese beiden Fragestellungen werden für unterschiedliche Kohorten mit retrospektiven Lebensverlaufsdaten untersucht. Zum einen wird festgestellt, dass die Wahlbeteiligung in den 1970er und 1980er Jahren tatsächlich wegen einer gewachsenen Zahl bekennender Nichtwähler gesunken war. Zum anderen bestätigt es sich, dass der soziale Wandel in der Höhe der Wahlbeteiligung vornehmlich auf das geänderte Wahlverhalten in der Abfolge politischer Generationen zurückzuführen ist. Während das Alter der Wahlberechtigten dabei kaum eine Rolle spielte, waren Periodeneffekte, die Veränderungen von gesellschaftlichen Verhältnissen und des Politikangebots widerspiegelten, von sekundärer Bedeutung.

Novel Features of the Prenatal Horn Bud Development in Cattle (Bos taurus).

Whereas the genetic background of horn growth in cattle has been studied extensively, little is known about the morphological changes in the developing fetal horn bud. In this study we histologically analyzed the development of horn buds of bovine fetuses between ~70 and ~268 days of pregnancy and compared them with biopsies taken from the frontal skin of the same fetuses. In addition we compared the samples from the wild type (horned) fetuses with samples taken from the horn bud region of age-matched genetically hornless (polled) fetuses. In summary, the horn bud with multiple layers of vacuolated keratinocytes is histologically visible early in fetal life already at around day 70 of gestation and can be easily differentiated from the much thinner epidermis of the frontal skin. However, at the gestation day (gd) 212 the epidermis above the horn bud shows a similar morphology to the epidermis of the frontal skin and the outstanding layers of vacuolated keratinocytes have disappeared. Immature hair follicles are seen in the frontal skin at gd 115 whereas hair follicles below the horn bud are not present until gd 155. Interestingly, thick nerve bundles appear in the dermis below the horn bud at gd 115. These nerve fibers grow in size over time and are prominent shortly before birth. Prominent nerve bundles are not present in the frontal skin of wild type or in polled fetuses at any time, indicating that the horn bud is a very sensitive area. The samples from the horn bud region from polled fetuses are histologically equivalent to samples taken from the frontal skin in horned species. This is the first study that presents unique histological data on bovine prenatal horn bud differentiation at different developmental stages which creates knowledge for a better understanding of recent molecular findings.

The 1987 debris flows in Switzerland: documentation and analysis

A great number of debris flows occurred during the flood catastrophes of the summer of 1987 in the Swiss Alps. Aerial photography, field investigations and eyewitness accounts documented and analysed the events. As an example of the reconstructed major events, the large debris flow in the Varuna valley involved an estimated peak discharge between 400 and 800 m3/s and an event magnitude of 200,000 m3. Several single pulses were observed; the duration of each of them appeared to be not more than a few minutes. Apart from incision into weak bedrock, the maximum erosion depth seemed to depend on the channel gradient. Based on approximately 600 events, typical starting zones and rainfall conditions are discussed with regard to the triggering conditions. Existing and new empirical formulae are proposed to estimate the most important flow parameters. These values are compared to debris flow data from Canada and Japan.