Theoretical perspective on rebound effects from a social science point of view: Working paper to prepare empirical psychological and sociological studies in the REBOUND project

The replacement of appliances and other energy using products by more efficient ones is generally regarded as an effective strategy to reduce energy demand. However, the savings realized by this strategy may be lower than those theoretically expected or calculated from a technological point of view due to changes of behaviour following the acquisition. This phenomenon is known as the rebound effect. While scientists generally agree on the existence of rebound effects, size, relevance and explanations of such effects are controversially discussed. This paper discusses concepts to explain rebound effects from a psychological as well as sociological point of view. In particular, an approach which combines variables from psychological action theories with the sociological life-style concept is suggested as a framework for studying determinants of rebound effects. --

Experimental and theoretical investigation of direct frequency comb spectroscopy

This thesis reports on theoretical and experimental examination of two-photon direct frequency comb spectroscopy (DFCS) using atomic two-level systems. This method is a very promising tool to extend optical spectroscopy into the short wavelength region where only few cw laser sources exist. The high peak intensities of pulsed lasers facilitate efficient nonlinear conversion into frequency regions which are so far unexplored, for example by high harmonic generation (HHG). DFCS is based on theoretical work in the 1970s which showed that a pulse train of a mode-locked laser drives a two-photon transition as efficient as a cw laser of same average power. Thereby the effective line width is determined by the narrow width of a single comb mode rather than by the spectral width of a single pulse. In this way a frequency comb combines the spectral purity of a cw laser with the high peak intensity of a pulsed laser. To demonstrate the capability of a nonlinearly converted frequency comb for DFCS, the absolute frequency of a two-photon transition in $^{24}$Mg at 431~nm was measured in a first experiment. The accuracies of the values could be improved by more than two orders of magnitude with respect to previously reported values. Furthermore two crucial effects which affect the transition rates were analyzed quantitatively for the first time: the impact of a linear chirp and non-centered spectral envelope on the spectroscopy. In general the pulses of a nonlinear converted frequency comb are not bandwidth limited leading to a partially destructive pairwise addition of modes. To describe the impact of a linear chirp a theoretical model was developed and verified experimentally using two-photon spectroscopy on cesium. Moreover, theory and experiment have shown a Gaussian decrease in the transition rate with increasing detuning of the laser spectrum. %Another important aspect is the centering of the laser spectrum with respect to the atomic transition. Theory and experiment show here a Gaussian decrease in the transition rate with increasing detuning. Finally the progress of $1S - 3S$ spectroscopy in hydrogen is presented. This transition is a promising candidate for a test of bound state quantum electrodynamics. Using cw lasers the required wavelength of 205~nm is hard to generate, making this transition to an eligible system for DFCS. Beside the experimental achievements also the lessons learned from Cs and Mg spectroscopy and their consequences for the H spectroscopy are discussed. In the scope of this work a frequency quadrupled laser system was extended and improved, providing ps frequency combs of high average power and good beam profile at 820~nm, 410~nm and 205~nm. An overall output power of max. 100~mW is now available at 205~nm, the up to date highest power generated by SHG. Moreover for H spectroscopy a new spectrometer was designed and built

Characterization of Vertebrate Cohesin Complexes and Their Regulation in Prophase

In eukaryotes, sister chromatids remain connected from the time of their synthesis until they are separated in anaphase. This cohesion depends on a complex of proteins called cohesins. In budding yeast, the anaphase-promoting complex (APC) pathway initiates anaphase by removing cohesins from chromosomes. In vertebrates, cohesins dissociate from chromosomes already in prophase. To study their mitotic regulation we have purified two 14S cohesin complexes from human cells. Both complexes contain SMC1, SMC3, SCC1, and either one of the yeast Scc3p orthologs SA1 and SA2. SA1 is also a subunit of 14S cohesin in Xenopus. These complexes interact with PDS5, a protein whose fungal orthologs have been implicated in chromosome cohesion, condensation, and recombination. The bulk of SA1- and SA2-containing complexes and PDS5 are chromatin-associated until they become soluble from prophase to telophase. Reconstitution of this process in mitotic Xenopus extracts shows that cohesin dissociation does neither depend on cyclin B proteolysis nor on the presence of the APC. Cohesins can also dissociate from chromatin in the absence of cyclin-dependent kinase 1 activity. These results suggest that vertebrate cohesins are regulated by a novel prophase pathway which is distinct from the APC pathway that controls cohesins in yeast

Bringing together bibliometrics research from different disciplines – what can we learn from each other?

Currently, there is little exchange between the different communities interested in the domain of bibliometrics. A recent conference aimed to bridge this gap. Peter Kraker, Katrin Weller, Isabella Peters and Elisabeth Lex report on the multitude of topics and viewpoints covered on the quantitative analysis of scientific research. A key theme was the strong need for more openness and transparency: transparency in research evaluation processes to avoid biases, transparency of algorithms that compute new scores and openness of useful technology

George Gershwins und Jerome Kerns Musicalsongs - Ihre Ähnlichkeit, Wahrnehmung und musikalische Struktur

Wie wird eine Ähnlichkeit in der Musik wahrgenommen, welche Elemente beeinflussen den erlebten Eindruck, und wie kann sie anhand von Beispielen vorgestellt und nachvollzogen werden? Diese Fragen bilden den zentralen Ansatz der Arbeit. Ziel ist die Präsentation einer neuen Methode, welche es ermöglichen eine kleine Auswahl an Musikliteratur synkritisch zu untersuchen. Den thematischen Auftakt der Arbeit bildeten die Kurzbiographien von George Gershwin und Jerome Kern mit einem Einblick über ihre musikalische Zusammenarbeit. Die Betrachtung ihrer Kompositionen fokussiert sich auf die Musicals, speziell die Musicalsongs. Mittels der Musicalsongs soll die musikalische Ähnlichkeit der Werke nachgewiesen werden. Bevor diese Frage in den Einzelanalysen besprochen wird, muss der Terminus Ähnlichkeit genauer betrachtet werden. Der gesamte Bereich der Arbeit, welcher sich mit dem Begriff Ähnlichkeit beschäftigt, ist aufgeteilt in drei große thematische Bereiche. Neben der Begriffserläuterung wird der Terminus sowie seine Semantik für die Naturwissenschaft, die Psychologie und die Musik besprochen. Die Ähnlichkeitsfrage zwischen mehrere Songs wird nicht mittels eines Computers, sondern unter Hinzunahme einer Befragung von 46 Probanden untersucht. Diese Methode bezieht die menschliche Wahrnehmung mit ein. Erfahrungen, welche die Urteilsbildung jedes Probanden beeinflussen, können von einem Computerprogramm nicht simuliert werden. Für die Befragung wurden gleichermaßen musikalisch gebildete und nicht gebildete Personen ausgewählt. Die Vorstellung einer neuen Untersuchungsmethode impliziert die Definition des Begriffs Ähnlichkeit mit der Reflexion sowie die Integrierung von bereits bestehenden Ansätzen. Die Analysen der Song-Paare, welche in der Befragung vorgestellt werden, soll die Ähnlichkeit in der Musik der Komponisten belegen oder gegebenenfalls widerlegen. Kernpunkte sind nicht nur harmonische Analysen, sondern der motivische Aufbau der Melodielinie, der Parameter Rhythmus und die harmonischen Funktionen werden einbezogen