City-Life No More? Young Adults' Disrupted Urban Experiences and Their Digital Mediation under Covid-19

The Covid-19 pandemic temporarily, yet significantly, reshuffled the position, functions and (mediated) constructions of cities and urban places. The national lockdown, implemented by Austria on 16 March 2020, turned cities overnight from centres of hybrid cultural, economic, social, political life and power to places where urban life(styles) were put on hold. This article begins by presenting first key results of a longitudinal study with young adults studying in educational institutions in the state of Tyrol through the harshest country-wide lockdown measures and their gradual withdrawal. We analyse how participants coped with the disruption of their urban lives and lifestyles and the strategies they employed to compensate. We highlight three main insights. First, participants who had originally migrated to the city from their (often rural) hometowns largely returned to join their families. From there, no longer being an object of physical experience, the city became a digitally imagined, constructed and communicated place, reiterating public discourses that condemned the city as a place where lockdown measures were breached, and the virus spread unchecked. Second, where possible and adapted to the affordances of digital media, students shifted their previous lifestyles to digital space as well as created innovative ways of socialising digitally—thus producing alternative digital forms of urban lifestyles and digitally-mediated urban experiences. Third, during the lockdown period, the importance, use intensity as well as a variety of digital media peaked tremendously. This trend, however, was short-lived as yearned-for offline sociability largely returned to the city once measures were relaxed, leaving those in rural homes detached from their urban peers

Stringency of the 2-His–1-Asp Active-Site Motif in Prolyl 4-Hydroxylase

The non-heme iron(II) dioxygenase family of enzymes contain a common 2-His–1-carboxylate iron-binding motif. These enzymes catalyze a wide variety of oxidative reactions, such as the hydroxylation of aliphatic C–H bonds. Prolyl 4-hydroxylase (P4H) is an α-ketoglutarate-dependent iron(II) dioxygenase that catalyzes the post-translational hydroxylation of proline residues in protocollagen strands, stabilizing the ensuing triple helix. Human P4H residues His412, Asp414, and His483 have been identified as an iron-coordinating 2-His–1-carboxylate motif. Enzymes that catalyze oxidative halogenation do so by a mechanism similar to that of P4H. These halogenases retain the active-site histidine residues, but the carboxylate ligand is replaced with a halide ion. We replaced Asp414 of P4H with alanine (to mimic the active site of a halogenase) and with glycine. These substitutions do not, however, convert P4H into a halogenase. Moreover, the hydroxylase activity of D414A P4H cannot be rescued with small molecules. In addition, rearranging the two His and one Asp residues in the active site eliminates hydroxylase activity. Our results demonstrate a high stringency for the iron-binding residues in the P4H active site. We conclude that P4H, which catalyzes an especially demanding chemical transformation, is recalcitrant to change

The Role of Nonheme Transition Metal-Oxo, -Peroxo, and -Superoxo Intermediates in Enzyme Catalysis and Reactions of Bioinspired Complexes

Transition metals are common cofactors in enzymes and enable catalysis to take place via reaction barriers that are accessible at room temperature. Oxygen-activating metalloenzymes are versatile species in Nature involved in vital processes ranging from biodegradation to biosynthesis. Since oxygen-activating intermediates are not readily amenable to experimental study, research has started to focus on biomimetic model systems that have the active site coordination sphere and structural features, but react in solution. In our research group, we have been involved in computational modeling of heme and nonheme iron dioxygenases as well as biomimetic models of these complexes. In this contribution, an overview is given on recent results of the characterization and reactivity patterns of metal-oxo, metal-peroxo, and metal-superoxo complexes. In particular, in recent studies attempts were made to trap and characterize the short-lived oxygen-bound intermediate in the catalytic cycle of cysteine dioxygenase. Many suggested structures could be ruled out by theoretical considerations, yet these also provided suggestions of possible candidates for the experimentally observed spectra. In addition, we review recent studies on the nonheme iron(III)-hydroperoxo species and how its reactivity patterns with arenes are dramatically different from those found for heme iron(III)-hydroperoxo species. In the final two sections there is a description, with illustrations, of a series of computational studies on manganese(V)-oxo and side-on manganese(III)-peroxo moieties that identify a unique spin-state reactivity pattern with a surprising product distribution.</p

Evaluation of the stocking program for European grayling (Thymallus thymallus) in the upper Inn River, using ddRAD-supported parentage analysis

Die \uc4sche (Thymallus thymallus) ist eine von 4 Salmonidenarten im Inn. Ihr Bestand ist in den letzten Jahrzehnten zur\ufcckgegangen. Seit 2016 l\ue4uft ein Bestandsbewirtschaftungsprogramm, das darauf abzielt, die \uc4schenpopulation des Inns zu erhalten. Vor einigen Jahren wurde ein genetisch basiertes (ddRAD-Sequenzierung) cberwachungsprojekt gestartet, um die Wirksamkeit dieses Bestandsbewirtschaftungsprogramms zu bewerten. Die vorliegende Masterarbeit befasst sich mit der computergest\ufctzten Analyse von ddRAD-Daten, die im Rahmen dieses cberwachungsprojekts gewonnen wurden. Im Wesentlichen wurde eine programmierte Pipeline erstellt, die die ddRAD-Rohdaten aufnimmt und verarbeitet, einschlie flich der Durchf\ufchrung einer Abstammungsanalyse von Genotypen, die von elterlichen Brutfischen und ihren Nachkommen, die f\ufcr den Besatz im Inn verwendet wurden, erzeugt wurden. Ziel dieser Analyse ist es, zu bewerten, inwieweit das Bestandsmanagementprogramm zur Population der frei im Inn lebenden \uc4sche beitr\ue4gt.The European grayling (Thymallus thymallus) is one of 4 salmonid species in the River Inn. Its population has been reduced over recent decades. A stock management program has been running since 2016, aimed at supporting the Inn River grayling population. Several years ago, a genetic-based (ddRAD sequencing) monitoring project was launched to try and evaluate the efficacy of this stock management program. This master thesis deals with the computer-based analysis of ddRAD data thus far generated for this monitoring project. Essentially, a programmed pipeline was generated, which takes in the raw ddRAD data and processes it including carrying out a parentage analysis of genotypes generated from parental brood fish and their offspring, which were used for stocking in the Inn River. The aim of this analysis is to try and evaluate how much the stock management program contributes to the population of grayling living freely in the Inn River.vorgelegt von Florian StraganzMasterarbeit Universit\ue4t Graz 2023Zusammenfassung auf Englisch und Deutsc