Adaptation an ultraviolette Strahlung in marinen grünen Makroalgen: Abschirmung und Toleranz

For plants and algae UVB radiation represents an important stress factor associated with sunlight. This radiation has the potential to inhibit physiological processes like photosynthesis as well as to damage molecules like the DNA. In plants adaptation to UVB radiation is based on two main resistance mechanisms: physical screening or cellular tolerance. The main goal of this thesis was to investigate to which extent and how precisely these strategies are present in different representatives of green macroalgae. For the first time UV screening was discovered in the order Cladophorales and the connected photoprotective function could be demonstrated in UVB challenge experiments. In contrast the majority of the remaining orders did not exhibit UV screening and was analyzed for the alternative resistance mechanisms like photosystem II (PS II) repair and DNA repair capacities. Especially species from the very abundant and often highlight exposed genus Ulva had an outstandingly high UVB tolerance of PS II. Field experiments corroborated the high potential of cellular UVB tolerance mechanisms in Ulva intestinalis

Relative sensitivity of DNA and photosystem II in Ulva intestinalis (Chlorophyta) under natural solar irradiation

High intensities of sunlight can result in DNA and photosystem II (PSII) damage. However, the relative sensitivity of both these targets under natural sunlight and especially over a long period has not been studied in algae so far. Although DNA damage is highly specifically induced by ultraviolet-B radiation (UVB, 280-315 nm), PSII is inactivated by a broad spectrum. The green macroalga Ulva intestinalis is an appropriate and interesting study organism with which to investigate the relative importance of the 2 different targets of sunlight because this alga contains no UV-screening protective pigments, although it is exposed to strong solar irradiation in its natural habitat. This entails a high risk of DNA damage. Therefore, diel time courses and long-term development of DNA damage and the optimal quantum yield of PSII (F-v/F-m) were studied in situ. F-v/F-m was extremely reduced at noon, but a fast recovery was observed in the afternoon. As dark-adapted basal fluorescence (F-o) of PSII was substantially decreased during the day, non-photochemical quenching is suggested to be a key photoprotective strategy in U. intestinalis. In contrast, even in samples with strongly reduced F-v/F-m, only very low DNA damage was found, irrespective of the accumulated UVB dose. We propose that efficient photoreactivation driven by natural sunlight balances the induction of dimers. This leads to a higher UVB tolerance of DNA than that observed in algae under experimental UVB irradition. In this field study, U. intestinalis suffered more from photoinhibition than from DNA damage

Verfahren der Organisation gesprochener Sprache:eine interaktional-linguistische Analyse von Pronominaladverbien und verwandten Formen

Gegenstand der Studie ist ein aktuelles Phänomen der Syntax des gesprochenen Deutsch: die Verwendung verschiedener Realisierungsweisen von Pronominaladverbien. Neben der standardsprachlich kodifizierten Norm sind im alltäglichen Sprachgebrauch vielfältige Realisierungen anzutreffen, z. B. Distanzkonstruktionen wie „da … für“. In der empirischen Arbeit wird die kommunikative Verwendung der unterschiedlichen Formen im Rahmen ihrer Funktion als retraktiv und projektiv verweisende Formen untersucht. Dazu werden freie gesprochene Interaktionen nach GAT2 transkribiert und auf Grundlage gesprächsanalytischer Methodik und der Gesprochene-Sprache-Forschung ausgewertet. Herausgearbeitet werden Sprecherrollen, die sequenzielle Positionierung, ihre Syntax und Topologie, die Semantik und Prosodie sowie funktional-pragmatische Aspekte (Informationsstrukturierung). Die gesprächsanalytischen Ergebnisse werden anschließend im Hinblick auf restringierte oder präferierte Verwendungskontexte gedeutet

Regio- and stereoselective fungal oxyfunctionalisation of limonenes

Selective transformations of limonene by asco- and basidiomycetes were investigated. On the shake flask scale, Penicillium citrinum hydrated R-(+)-limonene to α-terpineol [83% regioselectivity (rs), more than 80 mg l-1 product yield], and Gongronella butleri catalysed the terminal oxidation to yield perillyl alcohol (60% rs, 16 mg l-1). On the laboratory bioreactor scale, Penicillium digitatum produced a peak concentration of 506 mg α-terpineol l-1 in the fed-batch mode, equivalent to a theoretical yield of 67%, and no volatile by-products were found. Fusarium proliferatum transformed R-(+)-limonene enantiospecifically to cis-(+)-carveol (98.6% ee, more than 35 mg l-1 product yield) and S-(-)-limonene predominantly to trans-(-)-carveol (96.3% ee). Pleurotus sapidus selectively dehydrogenised the accumulating trans-(-)-carveol to the corresponding enantiopure R-(-)-carvone. The results show that a careful selection of strain and bioprocess parameters may improve both the yield and the optical purity of a desired product

Perfectionism and achievement goals in athletes: Relations with approach and avoidance orientations in mastery and performance goals

Objectives: Challenging views that perfectionism is a maladaptive factor in sport and that it is related to a preoccupation with performance goals and a neglect of mastery goals, the present article argues that perfectionism in athletes is not generally maladaptive, but shows differential relationships with mastery and performance goals depending on which facets of perfectionism are regarded. Method: Going beyond the dichotomous achievement goal framework, two studies with N = 204 high school athletes and N = 147 university student are presented investigating how two facets of perfectionism-striving for perfection and negative reactions to imperfection [Stoeber, J., Otto, K., Pescheck, E., Becker, C., & Stoll, O. (2007). Perfectionism and competitive anxiety in athletes: Differentiating striving for perfection and negative reactions to imperfection. Personality and Individual Differences, 42, 959-969.]-relate to athletes' achievement goals. Design: Study 1 employed a cross-sectional correlational design, Study 2 a longitudinal correlational design. Results: Following the trichotomous achievement goal framework, Study 1 found striving for perfection to be positively related to mastery and performance-approach goals, whereas negative reactions to imperfection were positively related to performance-approach and performance-avoidance goals and inversely to mastery goals. Following the 2 x 2 framework, Study 2 found striving for perfection to be positively related to mastery-approach and performance-approach goals whereas negative reactions to imperfection were positively related to mastery-avoidance, performance-approach, and performance avoidance goals. Moreover, negative reactions to imperfection predicted residual increases in mastery avoidance goals over 3 months. Conclusions: It is concluded that striving for perfection in athletes is associated with an adaptive pattern of achievement goals whereas negative reactions to imperfection are associated with a maladaptive pattern. Thus, striving for perfection in sport may be adaptive in athletes who do not experience strong negative reactions when performance is less than perfect

M. Christian Peschecks ... Deutliche Erklärungen derer Kauffmann- und oeconomischen Rechnungen, als da sind, Tara- und Fusti-Rechnung, Regula Detri inversa, Regula quinq., vel dupla, Regula conversa, Zinss- oder Interesse-, Zeit-, Gewinn- und Verlust-, Stich- oder Baratt-, Gesellschaft-, Erbtheil-, Gemeine- und Haupt- Wechsel-Rechnung, ingleichen Alligation-, Coeci- und Falsi-Rechnung, welche bisshero unter diesen beyden Titeln: Fortsetzung und Beschluss der Rechen-Kunst

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M. Christian Pescheck's Gymn. Zitt. Coll. Sen. & Pr. Matheseos Jtaliänische Rechen-Stunden : Darinnen Die Fünf Species der Rechen-Kunst mit unbenahmten und benahmten gantzen als auch gebrochenen Zahlen, Nebst der Regula De-Tri ohne und mit Brüchen, nach der so genannten Italiänischen Practica ... abgehandelt und erkläret sind ; Am Ende ist auch Eine kurtze Alphabetische Nachricht von denen ausländischen Müntz-Sorten ... beygefüget

Vorlageform des Erscheinungsvermerks: Leipzig und Zittau, Verlegts Johann Jacob Schöps, 1745