Spontaneous Symmetry Breaking and the Renormalization of the Chern-Simons Term

We calculate the one-loop perturbative correction to the coefficient of the \cs term in non-abelian gauge theory in the presence of Higgs fields, with a variety of symmetry-breaking structures. In the case of a residual $U(1)$ symmetry, radiative corrections do not change the coefficient of the \cs term. In the case of an unbroken non-abelian subgroup, the coefficient of the relevant \cs term (suitably normalized) attains an integral correction, as required for consistency of the quantum theory. Interestingly, this coefficient arises purely from the unbroken non-abelian sector in question; the orthogonal sector makes no contribution. This implies that the coefficient of the \cs term is a discontinuous function over the phase diagram of the theory.Comment: Version to be published in Phys Lett B., minor additional change

Fish communities in gravel pit lakes: The impact of fisheries management and littoral structures

Im ersten Teil meiner Arbeit habe ich den Einfluss von Seeentstehung und fischereilicher Bewirtschaftung auf Artenreichtum und Zusammensetzung der Fischgemeinschaften in kleinen Seen untersucht. Dafür habe ich fischereilich ungenutzte Naturseen als Referenz herangezogen und deren Fischgemeinschaft mit der von unbewirtschafteten Baggerseen, sowie fischereilich genutzten Baggerseen und Naturseen verglichen. Im zweiten Teil meiner Arbeit habe ich die Mechanismen der Totholzrekrutierung in Baggerseen untersucht und die Wichtigkeit von Totholz und anderen Litoralstrukturen im Vergleich zu den klassischen Seenvariablen Nährstoffgehalt und Seemorphologie auf die Fischabundanz im Litoral analysiert. Des Weiteren habe ich die Habitat-spezifischen Effekte auf die artspezifische, litorale Fischabundanz und die Effekte von zusätzlich eingebrachten Totholzbündeln auf die Abundanz typischer Fischarten in Baggerseen analysiert. Ich habe herausgefunden, dass fischereiliche Bewirtschaftung die Anzahl der Fischarten in Bagger- und Naturseen erhöht ohne die Zusammensetzung der Fischgemeinschaft im Vergleich zu fischereilich ungenutzten Naturseen signifikant zu verändern. Im Gegensatz dazu unterscheidet sich die Fischgemeinschaft in fischereilich ungenutzten Baggerseen durch das Fehlen von typischen Seefischarten und eine hohe Variabilität in der Zusammensetzung zwischen den Gewässern. Ich konnte zeigen, dass die litorale Totholzmenge in Baggerseen durch die Baumdichte am Ufer in Kombination mit der Windrichtung, durch fischereiliche Bewirtschaftung in Interaktion mit der Uferneigung und das Alter der Gewässer getrieben wird und entsprechend in jungen Baggerseen niedriger ist als in alten Naturseen. Ich fand heraus, dass Litoralstrukturen, wie Totholz, wertvolle Lebensräume darstellen, wichtige Deskriptoren der art-spezifischen, litoralen Fischabundanz sind und die Fischabundanz grundsätzlich mit der Strukturmenge ansteigt.In the first part of my thesis, I studied the effects of lake genesis and fisheries management on fish species richness and community composition in small lakes. I used fish communities in unmanaged natural lakes as reference and compared them to unmanaged gravel pit lakes as well as managed gravel pit and natural lakes. In the second part, I investigated the recruitment of littoral deadwood in gravel pit lakes and analysed the importance of deadwood and other littoral structures on littoral fish abundance in gravel pit lakes compared to the lake environmental variables such as nutrient level and lake morphology. I further analysed habitat-specific effects on species-specific littoral fish abundance and focussed explicitly on the effects of deadwood bundles implemented in the littoral zone. I found fisheries management to increase the number of fish species in gravel pit and natural lakes, but not leading to different fish community compositions compared to unmanaged natural lakes. By contrast, unmanaged gravel pit lakes were characterized by a lack of typical lake fish species and a high variation in fish community composition among lakes (β-diversity). I detected littoral deadwood densities in gravel pit lakes to be mainly driven by lake age, riparian tree density in interaction with wind direction and littoral slope in angler-managed lakes, with lowest deadwood densities in shallow areas of angler-managed lakes. Furthermore, deadwood densities were lower in young gravel pit lakes compared to old natural lakes. I detected littoral structures, such as littoral deadwood, as appropriate habitats and important descriptors of the species-specific, littoral fish abundance in gravel pit lakes with generally positive effects of structure extension on fish abundance. Littoral habitat characteristics were mostly of similar, or even higher, importance for fish abundance compared to lake environmental factors

The impact of IFRS 16 on Adidas AG’s financial statements and company valuation

IFRS 16 provides new guidance on accounting for leases which will have a significant impact on Adidas’ financial statements and company valuation as the company has strongly relied on off-balance sheet financing. Under IFRS 16, leases will be classified either as ‘Right-of-use asset’ which is representing the right to use the underlying asset or as ‘Lease liability’ which corresponds to the obligation to pay for the leased assets. IFRS 16 increases Adidas’ EBITDA and EBIT by the value of newly recognised lease interest expenses but the total cash flow remains unaffected. In terms of valuation, the main impacts of IFRS 16 are the adjusted Enterprise-Equity-Bridge and especially the increasing debt portion of the WACC which lowers Adidas’ cost of capital. Adidas’ share price is very sensitive to the implementation of IFRS 16 as the value of lease liabilities has a significant impact on the company’s WACC and, therefore, on the related valuation

Recombinant expression and functional characterisation of regiospecific flavonoid glucosyltransferases from Hieracium pilosella L.

Five glucosyltransferases were cloned by RT-PCR amplification using total RNA from Hieracium pilosella L. (Asteraceae) inflorescences as template. Expression was accomplished in Escherichia coli, and three of the HIS-tagged enzymes, UGT90A7, UGT95A1, and UGT72B11 were partially purified and functionally characterised as UDP-glucose:flavonoid O-glucosyltransferases. Both UGT90A7 and UGT95A1 preferred luteolin as substrate, but possessed different regiospecificity profiles. UGT95A1 established a new subgroup within the UGT family showing high regiospecificity towards the C-3' hydroxyl group of luteolin, while UGT90A7 primarily yielded the 4'-O-glucoside, but concomitantly catalysed also the formation of the 7-O-glucoside, which could account for this flavones glucoside in H. pilosella flower heads. Semi quantitative expression profiles revealed that UGT95A1 was expressed at all stages of inflorescence development as well as in leaf and stem tissue, whereas UGT90A7 transcript abundance was nearly limited to flower tissue and started to develop with the pigmentation of closed buds. Other than these enzymes, UGT72B11 showed rather broad substrate acceptance, with highest activity towards flavones and flavonols which have not been reported from H. pilosella. As umbelliferone was also readily accepted, this enzyme could be involved in the glucosylation of coumarins and other metabolite

Spin-orbit coupled j=1/2 iridium moments on the geometrically frustrated fcc lattice

Motivated by experiments on the double perovskites La2ZnIrO6 and La2MgIrO6, we study the magnetism of spin-orbit coupled j=1/2 iridium moments on the three-dimensional, geometrically frustrated, face-centered cubic lattice. The symmetry-allowed nearest-neighbor interaction includes Heisenberg, Kitaev, and symmetric off-diagonal exchange. A Luttinger-Tisza analysis shows a rich variety of orders, including collinear A-type antiferromagnetism, stripe order with moments along the [111]-direction, and incommensurate non-coplanar spirals, and we use Monte Carlo simulations to determine their magnetic ordering temperatures. We argue that existing thermodynamic data on these iridates underscores the presence of a dominant Kitaev exchange, and also suggest a resolution to the puzzle of why La2ZnIrO6 exhibits `weak' ferromagnetism, but La2MgIrO6 does not.Comment: 5 pages, 5 figs, significantly revised to address referee comments, to appear in PRB Rapid Com

Effect of speaker age on speech recognition and perceived listening effort in older adults with hearing loss

Published online January 2012Purpose: Older adults exhibit difficulty understanding speech that has been experimentally degraded. Age-related changes to the speech mechanism lead to natural degradations in signal quality. We tested the hypothesis that older adults with hearing loss would exhibit declines in speech recognition when listening to the speech of older adults, compared with the speech of younger adults, and would report greater amounts of listening effort in this task. Methods: Nineteen individuals with age-related hearing loss completed speech recognition and listening effort scaling tasks. Both were conducted in quiet, when listening to high and low predictability phrases produced by younger and older speakers respectively. Results: No significant difference in speech recognition existed when stimuli were derived from younger or older speakers. However, perceived effort was significantly higher when listening to speech from older adults, as compared to younger adults. Conclusions: For older individuals with hearing loss, natural degradations in signal quality may require greater listening effort. However, they do not interfere with speech recognition – at least in quiet. Follow-up investigation of the effect of speaker age on speech recognition and listening effort under more challenging noise conditions appears warranted