The Contribution of the Pineal Gland on Daily Rhythms and Masking in Diurnal Grass Rats, Arvicanthis niloticus

Melatonin is a hormone rhythmically secreted at night by the pineal gland in vertebrates. In diurnal mammals, melatonin is present during the inactive phase of the rest/activity cycle, and in primates it directly facilitates sleep and decreases body temperature. However, the role of the pineal gland for the promotion of sleep at night has not yet been studied in non-primate diurnal mammalian species. Here, the authors directly examined the hypothesis that the pineal gland contributes to diurnality in Nile grass rats by decreasing activity and increasing sleep at night, and that this could occur via effects on circadian mechanisms or masking, or both. Removing the pineal gland had no effect on the hourly distribution of activity across a 12:12 light-dark (LD) cycle or on the patterns of sleep-like behavior at night. Masking effects of light at night on activity were also not significantly different in pinealectomized and control grass rats, as 1h pulses of light stimulated increases in activity of sham and pinealectomized animals to a similar extent. In addition, the circadian regulation of activity was unaffected by the surgical condition of the animals. Our results suggest that the pineal gland does not contribute to diurnality in the grass rat, thus highlighting the complexity of temporal niche transitions. The current data raise interesting questions about how and why genetic and neural mechanisms linking melatonin to sleep regulatory systems might vary among mammals that reached a diurnal niche via parallel and independent pathways

Entwicklung einer durch Primaerenergie angetriebenen Absorptionswaermepumpenanlage fuer die Beheizung von Wohnhaeusern Schlussbericht

With 16 refs., 27 figs.SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Micro-structured electrode arrays: glow discharges in Ar at atmospheric pressure using a variable radio frequency generator

Micro-structured electrode (MSE) arrays consist of an interlocked, comb like, capacitive electrode system with gap widths in the µm-range. The usage of the Paschen similarity law (pd = const.) enabled us to generate large area uniform glow discharges up to atmospheric pressure with our arrays. In order to ignite glow discharges at atmospheric pressure this approach is established next to using dielectric barrier arrays and plasma jets. Because of the industrial, scientific and medical (ISM) limitation of available radio frequencies the usual frequency for experiments is 13.56 MHz. With a variable radio frequency generator, it is possible to extend the applicability of the MSE arrays in order to gain more information about the frequency dependent breakdown mechanisms and to confirm the underlying theory. The electric parameters of the non-thermal plasma system are characterized by a special probe with an upper frequency detection limit of 60 MHz

Entwicklung eines durch Primaerenergie angetriebenen Absorptionswaermepumpen-Prototypen fuer die Beheizung von Wohnhaeusern (Zweistoffgemisch R 22-E 181)

SIGLEDEGerman

Auswertung der technisch-betrieblichen Ergebnisse des Referenzbetriebes Zugsicherungseinrichtungen. Schlussbericht

TIB: AC 9767+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman