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In this thesis, two different aspects of porous conjugated polymers as visible-light-active and heterogenous photocatalysts have been discussed: 1.) Synthesis strategies for control of hydrophilicity 2.) Metal-free photoredox mediated reaction design as replacement for traditional transition metal-catalyzed carbon-carbon bond formation reactions. The pristine hydrophobic polymers were modified by a specific functionalization in order to conduct photocatalysis in water. Two different molecular design strategies for modification of cross-linked conjugated polymers are presented. Moreover, the photocatalysts were applied to aqueous and non-aqueous reactions. The photocatalytic reaction mechanisms were elucidated by various methods. The first design strategy of the hydrophilicity control was demonstrated via a simple protonation step of a series of azulene-based conjugated microporous polymers (CMPs). Here, the protonation of the azulene units led to the formation and permanently stabilization of tropylium cations. This concept of the controlled change from hydrophobic to hydrophilic networks showed that highly functional CMPs can be used in both organic and aqueous solvent systems. After post-modification, the change on porosity, morphology, and opticalelectronical properties were analyzed. The photocatalytic efficiency of the modified polymers in water were demonstrated by the reduction of chromium(VI) to chromium(III), whereas the efficiency was comparable to established inorganic heterogeneous photocatalysts. The second example of hydrophilicity control was demonstrated by the combination of photoactive conjugated donor-acceptor polymers with cross-linkable ionic side groups, which led to the formation of a series of highly porous conjugated polyelectrolytes (CPEs). This concept merged multiple material properties: 1.) The irradiation with visible light led to a selfinitiation and cross-linkage process of the polymers; 2.) The amphiphilic properties allowed one to use the polymer as stabilization agent for colloids and emulsions; 3.) The irradiation with visible light of those aggregates leads to permanent cross-linkage, and therefore the formation of stable heterogeneous photocatalysts with defined macrostructure inside the materials. The material properties, the morphology, and the optical-electronical properties of the materials were analyzed. Finally, the photocatalytic performance by means of known reactions such as photodegradation of organic dyes or the photoreduction of metal-ions were demonstrated. The third example deals with the photocatalytic Stille-type C-C coupling reaction, which was demonstrated by the employment of azulene based conjugated polymers. In order to determine the range of C-C coupling reactions, a series of aromatic halides and aromatic stannanes were tested. The photoredox mediated reaction mechanism was investigated and the key steps have been identified. In addition, the elucidation of the photocatalytic reaction mechanism was conducted via electrochemical methods as well as indirect chemical methods or trapping and detection of reactive species.Diese Arbeit befasst sich mit neuen Konzepten für die Entwicklung von konjugierten polymerbasierten heterogenen Photokatalysatoren sowohl für die Anwendung im wässrigen als auch in nicht-wässrigen Lösungsmitteln. Es werden unterschiedliche Designstrategien für die Herstellung wasserkompatibler poröser Polymere vorgestellt. Darüber hinaus werden die unterschiedlichen mechanistischen Aspekte von photokatalytischen Reaktionen an Hand einer C-C Knüpfungsreaktion beschrieben. Die hier vorgestellten Designstrategien lassen sich als allgemeine Konzepte ansehen und sind auf andere vernetztbare Polymersysteme übertragbar. Zunächst wurden hydrophobe Polymere durch eine gezielte Funktionalisierung für die Photokatalyse in Wasser modifiziert. Zwei unterschiedliche molekulare Designstrategien für die Realisierung von hydrophilen heterogenen Photokatalysatoren auf Basis von vernetzten konjugierten Polymeren wurden umgesetzt. Das photoaktive Element dieser Photokatalysatoren besteht aus konjugierten Donor-Akzeptor Polymerketten, welche durch kovalente Vernetzung und Porenbildung neben einer signifikanten Stabilitätszunahme auch einen mehrfach synergetischen Effekt mit sich bringen. Anschließend wurde an Hand von vernetzten konjugierten Polymeren die effiziente metallfreie Photokatalyse von organischen Reaktionen demonstriert, und der photokatalytische Reaktionsmechanismus wurde aufgeklärt. Das erste Beispiel handelt von Azulen basierten konjugierten mikroporöse Polymere (CMPs). Die Azulen-CMPs zeichnen sich dadurch aus, dass durch einen einfachen Protonierungsschritt die Tropylium-Kationen der Azulen-Einheiten entstehen und dauerhaft stabilisiert werden. Durch dieses Konzept des kontrollierten Wechsels von hydrophoben zu hydrophilen Netzwerken konnte gezeigt werden, dass hochfunktionelle CMPs für eine Vielfalt von Lösungsmitteln einsetzbar sind. Die Auswirkungen der Postmodifikation auf die Porosität, die Morphologie und die optoelektronischen Eigenschaften wurden analysiert. Die photokatalytische Effizienz in Wasser wurde durch die Reduktion von Chrom (VI) zu Chrom(III)-Ionen demonstriert, wobei die Effizienz mit der der bisherigen anorganischen heterogenen Photokatalysatoren vergleichbar war. Im zweiten Beispiel werden photoaktive konjugierte Donor-Akzeptor-Polymere mit vernetzbaren ionischen Seitengruppen zu einem konjugierten Polyelektrolyten (CPE) kombiniert. Dieses Konzept vereint mehrere Materialeigenschaften. 1.) Die Bestrahlung mit sichtbarem Licht führt zu einer Selbstinitiierung und Vernetzung. 2.) Die amphiphile Eigenschaft ermöglicht es, dass das Polymer als Stabilisator für Kolloide und Emulsionen auftritt. 3.) Die stabilen Polymeraggregate lassen sich durch die Bestrahlung mit sichtbarem Licht dauerhaft vernetzen. Damit lassen sich stabile heterogene Photokatalysatoren mit definierter Makrostruktur herstellen. Die Materialeigenschaften vor der Vernetzung, die Morphologie und die optoelektronischen Eigenschaften wurden analysiert. Schließlich wurde die photokatalytische Leistungsfähigkeit an Hand bekannter Reaktionen wie Photoabbau von organischen Farbstoffen oder die Photoreduktion von Metallionen demonstriert.2 Im dritten Beispiel werden hydrophobe Azulen-basierte konjugierte Polymere als wiederverwendbare Photokatalysatoren in einer übergangsmetallfreien Stille Kupplungsreaktion eingesetzt. Das Anwendungsspektrum der Photokatalysatoren auf die C-C-Kupplungsreaktion wurde mit verschieden substituierten aromatischen Halogeniden und aromatischen Stannanen demonstriert. Die zugrundeliegenden Reaktionsmechanismen der photokatalytischen Stille-Reaktion wurden durch spezifische Modellreaktionen untersucht. Die Aufklärung der Mechanismen erfolgte sowohl mit elektrochemischen Methoden, als auch indirekt mit chemischen Methoden sowie durch Abfangen und Detektieren reaktiver Spezies

A three-years field study on visible diurnal spring migration at Lake Constance (southern Germany)

Wir erstellen derzeit die erste Datenbank zum sichtbaren Frühjahrszug des mitteleuropäischen Binnenlandes. Um den Frühjahrszug zu erfassen, wählten wir eine exponierte Beobachtungsstelle am Bodenseeufer aus. Die Daten wurden in den Jahren 1984 – 1986 erhoben (an insgesamt 194 Tagen mit 831 Beobachtungsstunden von Anfang März bis Anfang Mai, jeden Morgen von Sonnenaufgang bis späten Morgen bzw. Mittag). Das Projekt lieferte 35583 Einzelbeobachtungen mit insgesamt 138543 Individuen in 96 Arten. Einige Ergebnisse lassen sich mit der langjährigen niederländischen LWVT/SOVON Studie vergleichen, besonders im Hinblick auf das Zugverhalten von Waldvögeln. Weitere Themen der Studie sind: Median-Werte und Phänologie von vierzehn “Kalendervögeln” und des Schwarzmilans Milvus migrans, das Zugverhalten von typischen Standvögeln (Türkentaube Streptopelia decaocto, Rabenkrähe Corvus corone corone, Haussperling Passer domesticus), die Hauptzugrichtung (Beutelmeise Remiz pendulinus, Wiesenpieper Anthus pratensis, Heidelerche Lullula arborea), sowie Nachweise ziehender Gartenbaumläufer Certhia brachydactyla. Mit einer Wiederholungsstudie könnten möglicherweise Veränderungen im Zugverhalten der Heimzieher über die letzten Jahrzehnte festgestellt werden. Im nächsten Schritt vervollständigen wir die Endversion der Datenbank und publizieren sie online mit freiem Zugang durch das Internet, was eine Ausweitung der Analysen erlauben wird, z.B. im Hinblick auf Zugverhalten und vorherrschende Wetterbedingungen.We presently develop a data bank on visible diurnal spring migration. Data were collected in three spring periods (1984 – 1986) at an exposed observation point at the bank of Lake Constance (Bodensee, southern Germany). 831 observation hours were done in 194 days from beginning of March to beginning of May, each day from sunrise to late morning/midday. The project yielded 35,583 records of migrants, with a total number of 138,543 individuals in 96 species. The results from Lake Constance are briefly compared to a Dutch study (LWVT/SOVON 2002), particularly focusing on spring migration of forest birds. Moreover, the following points are addressed: median signals and phenology (with special emphasis on fourteen ‘calendar’ bird species and black kite Milvus migrans), migration behaviour of typical resident birds (for eurasian collared dove Streptopelia decaocto, carrion crow Corvus corone corone and house sparrow Passer domesticus), main migration heading (for penduline tit Remiz pendulinus, meadow pipit Anthus pratensis and wood lark Lullula arborea), and treecreepers Certhia brachydactyla as rare migrants. With a second, long-term investigation at Lake Constance putative changes in migration behaviour during the last decades could be detected. In the next step, we provide the final version of the database as open source, for free download from the Internet. This will allow other researchers an extension of comparative analyses, e.g. for a detailed evaluation of migration pattern and predominate weather conditions

The physical damage of climbing activity on sandstone lichen cover

Climbing activities affect cliff site species. With cliff sites harbouring unique species communities, the rise in popularity of outdoor climbing activities is a major threat. In this study, we assessed a previously unclimbed boulder before, during and after 500 climbing ascents. We observed an overall reduction in lichen cover by 4.2–9.5%, located around the footholds and combined foot- and handhold but not the handhold. We found the reduction in lichen cover to be strongest at the very start of the climbing treatment and to lessen over time. Therefore, management should focus on directing climbing activities to selected sites, while protecting sites with high conservation value where climbing is prohibited entirely.publishedVersio

Parallel adaptations to nectarivory in parrots, key innovations and the diversification of the Loriinae

Specialization to nectarivory is associated with radiations within different bird groups, including parrots. One of them, the Australasian lories, were shown to be unexpectedly species rich. Their shift to nectarivory may have created an ecological opportunity promoting species proliferation. Several morphological specializations of the feeding tract to nectarivory have been described for parrots. However, they have never been assessed in a quantitative framework considering phylogenetic nonindependence. Using a phylogenetic comparative approach with broad taxon sampling and 15 continuous characters of the digestive tract, we demonstrate that nectarivorous parrots differ in several traits from the remaining parrots. These trait-changes indicate phenotype–environment correlations and parallel evolution, and may reflect adaptations to feed effectively on nectar. Moreover, the diet shift was associated with significant trait shifts at the base of the radiation of the lories, as shown by an alternative statistical approach. Their diet shift might be considered as an evolutionary key innovation which promoted significant non-adaptive lineage diversification through allopatric partitioning of the same new niche. The lack of increased rates of cladogenesis in other nectarivorous parrots indicates that evolutionary innovations need not be associated one-to-one with diversification events

Sino-Himalayan mountains act as cradles of diversity and immigration centres in the diversification of parrotbills (Paradoxornithidae)

Aim: Montane regions like the Sino-Himalayas constitute global diversity hotspots. Various mechanisms such as in situ adaptive divergence, speciation following immigration or allopatric diversification in complex landscapes have been proposed to account for the exceptional diversity found in a particular clade in a montane setting. We investigated macroevolutionary patterns to test these different hypotheses in the continental radiation of a Sino-Himalayan bird group, the parrotbills (Paradoxornithidae).Location: Sino-Himalayan region, Indo-Burma.Methods: We used phylogenetic comparative methods based on a multilocus, time-calibrated phylogeny to reconstruct patterns of lineage diversification, biogeographical history, morphological evolution as well as of climate niche history using ecological niche modelling.Results: The radiation of parrotbills started c. 12 Ma, diversifying at an apparent constant rate over time. The biogeographical history appears to be complex, within-region speciation in mountains was restricted to China. Size evolution was concentrated in the early phase of parrotbill radiation, whereas morphological shape evolution did not differ from Brownian motion. We found no indication for niche conservatism, with climate niche evolution occurring throughout the radiation of parrotbills.Conclusions: Parrotbills diversified within a time span of increased regional orogenesis and associated strong climate change. While the south-west and central Chinese mountains were revealed to be a species pump, with in situ allopatric diversification triggered by complex topography and high habitat turnover, the diversity in the Himalayas was chiefly the result of immigration. Evidence for continuous ecological specialization and for the absence of climate niche conservatism could be interpreted as the consequence of ongoing climate- and habitat-induced ecological opportunities. The radiation of parrotbills demonstrates the influence of multiple drivers of diversification in a single group due to the dynamic geological and palaeoclimatic history of the Sino-Himalayan region and illustrates the complex nature of continental radiations

Inference of evolutionary jumps in large phylogenies using Lévy processes

Although it is now widely accepted that the rate of phenotypic evolution may not necessarily be constant across large phylogenies, the frequency and phylogenetic position of periods of rapid evolution remain unclear. In his highly influential view of evolution, G. G. Simpson supposed that such evolutionary jumps occur when organisms transition into so-called new adaptive zones, for instance after dispersal into a new geographic area, after rapid climatic changes, or following the appearance of an evolutionary novelty. Only recently, large, accurate and well calibrated phylogenies have become available that allow testing this hypothesis directly, yet inferring evolutionary jumps remains computationally very challenging. Here, we develop a computationally highly efficient algorithm to accurately infer the rate and strength of evolutionary jumps as well as their phylogenetic location. Following previous work we model evolutionary jumps as a compound process, but introduce a novel approach to sample jump configurations that does not require matrix inversions and thus naturally scales to large trees. We then make use of this development to infer evolutionary jumps in Anolis lizards and Loriinii parrots where we find strong signal for such jumps at the basis of clades that transitioned into new adaptive zones, just as postulated by Simpson’s hypothesis

Outdoor cycling activity affected by COVID-19 related epidemic-control-decisions

AimThe lockdown of sports infrastructure due to the COVID-19 pandemic has substantially shifted people's physical activity towards public green spaces. With Germany's lockdown as one of the more severe governmentally imposed epidemic-control-decisions, we tested to what extent the frequency of outdoor cycling activities changed from March to June 2020.MethodsUser behaviour and frequency in 15 urban and 7 rural German public green spaces was quantified using cycling data from the fitness application Strava. Changes in cycling activities were analysed with four different generalised linear models, correcting for factors like weather conditions and temporal changes in the user base of the fitness application.ResultsWe found a clear increase in outdoor cycling sport activities in urban public green spaces in response to epidemic-control decisions (e.g. increase by 81% in April relative to the expected value (95% CI [48%, 110%])). In contrast, biking in rural areas showed no significant change with epidemic-control-decisions in place.ConclusionFitness App data, e.g. from Strava, can be used to monitor visitor behaviour and frequency. The increase in outdoor cycling activities during epidemic control decisions likely reflects a shift of sport activities from indoor and team sports to outdoor and individual sports. This highlights the importance of accessible green space for maintaining physical fitness and health. Beyond this shift, it is likely that outdoor activities may be of particularly importance for stress relief in times of crisis such as the current COVID-19 pandemic

Blast from the Past?: A Comparative Analysis of Broadcast Licensing in the Digital Era

The advent of new broadcasting technologies has eliminated spectrum scarcity as a constraint on broadcasting, and with it one of the justifications for broadcast licensing. Have nations moved away from licensing as a form of regulation of their broadcasting sectors? And concomitantly, is there less opportunity to use licensing as a means of promoting the public interest in broadcasting? The authors address these questions through a comparative study of licensing requirements for terrestrial broadcasting and other forms of television and radio distribution in 18 Western nations

Trophic niche shifts and phenotypic trait evolution are largely decoupled in Australasian parrots

Background: Trophic shifts from one dietary niche to another have played major roles in reshaping the evolutionary trajectories of a wide range of vertebrate groups, yet their consequences for morphological disparity and species diversity differ among groups. Methods: Here, we use phylogenetic comparative methods to examine whether the evolution of nectarivory and other trophic shifts have driven predictable evolutionary pathways in Australasian psittaculid parrots in terms of ecological traits such as body size, beak shape, and dispersal capacity. Results: We found no evidence for an ‘early-burst’ scenario of lineage or morphological diversification. The bestfitting models indicate that trait evolution in this group is characterized by abrupt phenotypic shifts (evolutionary jumps), with no sign of multiple phenotypic optima correlating with different trophic strategies. Thus, our results point to the existence of weak directional selection and suggest that lineages may be evolving randomly or slowly toward adaptive peaks they have not yet reached. Conclusions: This study adds to a growing body of evidence indicating that the relationship between avian morphology and feeding ecology may be more complex than usually assumed and highlights the importance of adding more flexible models to the macroevolutionary toolbox.info:eu-repo/semantics/publishedVersio

An annotated chromosome-scale reference genome for Eastern black-eared wheatear (Oenanthe melanoleuca).

Pervasive convergent evolution and in part high incidences of hybridization distinguish wheatears (songbirds of the genus Oenanthe) as a versatile system to address questions at the forefront of research on the molecular bases of phenotypic and species diversification. To prepare the genomic resources for this venture, we here generated and annotated a chromosome-scale assembly of the Eastern black-eared wheatear (O. melanoleuca). This species is part of the O. hispanica-complex that is characterized by convergent evolution of plumage coloration and high rates of hybridization. The long-read-based male nuclear genome assembly comprises 1.04 Gb in 32 autosomes, the Z chromosome, and the mitogenome. The assembly is highly contiguous (contig N50: 12.6 Mb; scaffold N50: 70 Mb), with 96% of the genome assembled at chromosome level and 95.5% BUSCO completeness. The nuclear genome was annotated with 18,143 protein-coding genes and 31,333 mRNAs (annotation BUSCO completeness: 98.0%), and about 10% of the genome consists of repetitive DNA. The annotated chromosome-scale reference genome of Eastern black-eared wheatear provides a crucial resource for research into the genomics of adaptation and speciation in an intriguing group of passerines