31325 research outputs found
Sort by
Multilingualism and Juǀ’hoan language variation enGENDERed in a Namibian boarding school
No full textPrevious studies on grammatical gender in Ju|'hoan (Ju, Kx'a) attest to considerable cross-dialectal variation. But how stable are the reported innovations and are they being acquired by younger generations of Ju|'hoan? This paper presents the results of a pilot study undertaken with Juǀ’hoan teenagers attending the Hippo Primary School, an English-medium boarding school in the Omaheke district, Namibia. The paper describes the complexification of the gender system resulting from multilingual practices, standard language ideologies, and the absence of continuous access to 'traditional' language models. Crucially, the teenagers exhibit innovations undocumented elsewhere. Furthermore, the study offers no evidence that innovations attested in previous studies are being acquired younger generations. This might suggest that diversity is linked to variation in the socio-pragmatically dominant language, which changes over a speakers lifetime
Die Dioxygenierung von Thiolaten und Selenolaten - Biomimetische Modellkomplexe und Reaktivitätsstudien
No full textDie Dioxygenierung von Thiolaten ist ein essenzieller Bestandteil physiologischer Prozesse. Auch die synthetische Darstellung von Sulfinaten ist für die Chemie von Bedeutung. Auf Basis der Cysteindioxygenase (CDO), die Cystein (Cys) zu Cysteinsulfinsäure dioxygeniert, wurden Modellsysteme mit Trispyrazolylborat-Liganden entwickelt, um das aktive Zentrum der CDO nachzubilden und unfunktionalisierte Thiolate mit molekularem Sauerstoff zu Sulfinaten umzusetzen. Eine Reaktivität dieser bioinspirierten Komplexe mit O₂ konnte beobachtet werden, jedoch war die Selektivität aufgrund sterischer und elektronischer Faktoren eingeschränkt. Neben partieller Ligandenzersetzung traten verschiedene Oxidationsprodukte auf. Ergänzend wurde die Autooxidation von Thiolaten untersucht. Elektronenreiche Thiolate reagierten ohne Metallaktivierung mit O2, während elektronenärmere erst in Anwesenheit von Fe(II)-Ionen oxidiert wurden. Neben einer neuen Darstellungsmethode für Sulfinate wurden auch zentrale Eigenschaften der CDO mit Modellkomplexen untersucht. Dazu zählt die bemerkenswerte Spezifität des Enzyms: Der Austausch des Cofaktors von Fe zu Co oder des Substrats von Cys zu Selenocystein (Sec) hemmt im Enzym die Reaktivität gegenüber O₂. Im Modell zeigte sich hingegen eine erhöhte Reaktivität bei Substrattausch. Sowohl mit Fe als auch mit Co als Metallzentrum konnte eine Dioxygenierung von Sec beobachtet werden, ein Verhalten, das im Kontrast zur Spezifität der CDO steht. Diese Ergebnisse zeigen, dass biomimetische Modelle nicht nur funktionelle Einblicke in enzymatische Mechanismen erlauben, sondern auch neue Reaktivitätsmuster offenbaren können, die über das biologische Vorbild hinausgehen.The dioxygenation of thiolates is an essential part of physiological processes. The synthetic preparation of sulfinates is also of significant importance in chemistry. Based on cysteine dioxygenase (CDO), which converts cysteine (Cys) to cysteine sulfinic acid, model systems using trispyrazolylborate ligands were developed to mimic the active site of CDO and to convert unfunctionalized thiolates into sulfinates using molecular oxygen. Reactivity of these bioinspired complexes with O₂ was observed; however, selectivity was limited due to steric and electronic factors. In addition to partial ligand degradation, various oxidation products of the thiolate were detected. Additionally, the autooxidation of thiolates was investigated. Electron-rich thiolates reacted with O₂ without metal activation, while electron-poor thiolates required the presence of Fe(II) ions to undergo oxidation. Besides developing a new method for synthesizing sulfinates, key properties of CDO were studied using model complexes. These include the enzyme’s remarkable specificity: substituting the cofactor from Fe to Co or the substrate from Cys to selenocysteine (Sec) inhibits reactivity toward O₂ in the enzyme. In contrast, the model system showed increased reactivity upon substrate exchange. Dioxygenation of Sec was observed with both Fe and Co centers, demonstrating that the biomimetic model exhibits enhanced reactivity compared to the natural enzyme. These findings show that biomimetic models not only provide functional insight into enzymatic mechanisms but can also reveal new reactivity patterns that go beyond the biological system
Plasmon‐Mediated Hybridization of Wannier–Mott and Frenkel Excitons in a Monolayer WS2–J‐Aggregate Hybrid System
No full textA tunable plasmonic platform that allows room‐temperature hybridization of dissimilar excitons, namely of Wannier–Mott excitons in monolayer (1L) WS2 and Frenkel excitons in molecular J‐aggregates via simultaneous strong coupling (SC) to surface plasmon polaritons, is presented. It is based on a simple layered design consisting of a thin planar silver film and a dielectric spacer on which monolayer and the aggregates are assembled. SC is revealed by angle‐dependent spectroscopic ellipsometry measurements in total internal reflection geometry by the observation of double Rabi splitting at the two excitonic resonances. The exciton‐exciton‐plasmon system is analyzed with the coupled oscillator model, and modulation of polariton character and dynamics by the number of molecules participating in the coupling is demonstrated. Furthermore, a route is proposed to remotely control the mode splitting at the Frenkel excitonic resonance via electrostatic gating of the 1L‐WS2 and to switch the molecule–plasmon interaction between the weak and SC regime.Deutsche Forschungsgemeinschaft 10.13039/501100001659Peer Reviewe
Agreement classes, nominal form classes and gender in Setswana
No full textThis paper gives an overview of gender and noun classes in written Setswana distinguishing between nominal form classes and agreement classes. It argues against the synchronic recognition of the locative noun classes 16 and 18, and discusses cases of varying/variable agreement
Studien- und Prüfungsordnung für die Studienanteile Bildungswissenschaften und Sprachbildung im lehramtsbezogenen Masterstudiengang (für das Lehramt an Integrierten Sekundarschulen und Gymnasien)
No full textDetlef Siegfried: Alternative Dänemark. Kosmopolitismus im westdeutschen Alternativmilieu 1965–1985. Hamburger Beiträge zur Sozial- und Zeitgeschichte, Band 61. Göttingen: Wallstein 2023, 640 S.
No full textRNA-binding protein YebC enhances translation of proline-rich amino acid stretches in bacteria
No full textThe ribosome employs a set of highly conserved translation factors to efficiently synthesise proteins. Some translation factors interact with the ribosome in a transient manner and are thus challenging to identify. However, proteins involved in translation can be specifically identified by their interaction with ribosomal RNAs. Using a combination of proteomics approaches, we identified 30 previously uncharacterized RNA-binding proteins in the pathogenic bacterium Streptococcus pyogenes . One of these, a widely conserved protein YebC, was shown to transiently interact with 23S rRNA near the peptidyl-transferase centre. Deletion of yebC moderately affected the physiology and virulence of S. pyogenes . We performed ribosome profiling and detected increased pausing at proline-rich amino acid motifs in the absence of functional YebC. Further experiments in S. pyogenes and Salmonella Typhimurium and using an in vitro translation system suggested that YebC is a translation factor required for efficient translation of proteins with proline-rich motifs.Max-Planck-Gesellschaft (Max Planck Society)https://doi.org/10.13039/501100004189Deutsche Forschungsgemeinschaft (German Research Foundation)https://doi.org/10.13039/501100001659Peer Reviewe