121 research outputs found
Sea-bed photographs (benthos) from the Patagonian shelf (South America, South-West Atlantic) along profile PS40/110-6
No full textPhotos represent approx. 1m**2 each, taken vertically by Hasselblad 500EL/M with two strobes Metz mecablitz 45; Kodak Ektachrome 64; Minolta Dimage Scan Multi II; JPEG compression: 300 dpi, 21.4 x 20.0 cm; J. Gutt: mailto:[email protected]
Sea-bed photographs (benthos) from the Patagonian shelf (South America, South-West Atlantic) along profile PS40/106-6
No full textPhotos represent approx. 1m**2 each, taken vertically by Hasselblad 500EL/M with two strobes Metz mecablitz 45; Kodak Ektachrome 64; Minolta Dimage Scan Multi II; JPEG compression: 300 dpi, 21.4 x 20.0 cm; J. Gutt: mailto:[email protected]
Functional Characterization of a LOV-Histidine Kinase Photoreceptor from Xanthomonas citri subsp. citri
No full textThe blue-light (BL) absorbing protein Xcc-LOV from Xanthomonas citri subsp. citri is composed of a LOV-domain, a histidine kinase (HK) and a response regulator. Spectroscopic characterization of Xcc-LOV identified intermediates and kinetics of the protein's photocycle. Measurements of steady state and time-resolved fluorescence allowed determination of quantum yields for triplet (ΦT = 0.68 ± 0.03) and photoproduct formation (Φ390 = 0.46 ± 0.05). The lifetime for triplet decay was determined as τT = 2.4-2.8 μs. Fluorescence of tryptophan and tyrosine residues was unchanged upon light-to-dark conversion, emphasizing the absence of significant conformational changes. Photochemistry was blocked upon cysteine C76 (C76S) mutation, causing a seven-fold longer lifetime of the triplet state (τT = 16-18.5 μs). Optoacoustic spectroscopy yielded the energy content of the triplet state. Interestingly, Xcc-LOV did not undergo the volume contraction reported for other LOV domains within the observation time window, although the back-conversion into the dark state was accompanied by a volume expansion. A radioactivity-based enzyme function assay revealed a larger HK activity in the lit than in the dark state. The C76S mutant showed a still lower enzyme function, indicating the dark state activity being corrupted by a remaining portion of the long-lived lit state.Fil: Kraiselburd, Ivana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Gutt, Alexander. Max‐Planck‐Institute for Chemical Energy Conversion; AlemaniaFil: Losi, Aba. Università di Parma; ItaliaFil: Gärtner, Wolfgang. Max‐Planck‐Institute for Chemical Energy Conversion; AlemaniaFil: Orellano, Elena Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; Argentin
Sea-bed photographs (benthos) from the North Sea along ROV profile HE169_799
No full textROV (sprint 103) equiped with 36mm still camera; Kodak Ektachrome 100; Nikon super coolscan 4000ED; JPEG compression. Along the same transect sea-bed was videotaped in betacam format using same lense system; J. Gutt: mailto:[email protected]
Challenges of metarepresentation to translation competence.
No full textOne of the outcomes of the inferential framework of communication developed by Sperber and Wilson (1995) is the pursuit of competence-oriented research on translation (CORT), as proposed in Gutt 2000. CORT focuses on the discovery of the mental capabilities involved in the translation task.\ud
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One of the key concepts recently being explored in the inferential framework is that of metarepresentation. It involves the capability of people to represent in their minds not only the external world but the thoughts (mental representations) other people entertain about that world. Metarepresentations can involve several levels of embedding: thus persons can metarepresent to themselves the thoughts of others about their own thoughts about a certain subject matter etc.\ud
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While metarepresentation is an important mental faculty for successful communication in general, it is of eminent importance in the translation task where the translator may have to metarepresent several different worlds of thoughts (cognitive environments) and their interaction with one another as mutual cognitive environments in cross-cultural communication events.\ud
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This paper first briefly outlines the inferential model of translation, including the notions of cognitive environment, context and metarepresentation. The main part of the paper surveys five distinct constellations of mutual cognitive environments found in translation situations. The first – and ideal – constellation is where original author, translator and receptor audience all share essentially the same mutual cognitive environment. More commonly, however, this condition is not fulfilled and the other four constellations can present considerable challenges to the metarepresentational capabilities of the translator. Furthermore, the translator needs to develop strategies that will overcome differences in cognitive environment that would negatively affect the communication process. (This is in addition to the task of overcoming problems caused by language differences.) Suggestions are made about directions in which these problems, which can seriously undermine the success of the translated text, can be sought.\ud
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References\ud
Gutt, Ernst-August 2000 Translation and relevance: Cognition and context. Manchester: St. Jerome.\ud
Sperber, Dan and Deirdre Wilson 1995 Relevance: Communication and cognition. Oxford: Blackwell.\u
Sea-bed photographs (benthos) from the Scotia Arc (Antarctica) along profile PS61/155-1 (©AWI, Arntz and Gutt 2002)
No full textPhotos represent approx. 1qm each, taken vertically by Photosea PS70D with two strobes Photosea PS 3000SX; Kodak Ektachrome 64; Minolta Dimage Scan Multi II; JPEG compression: 300dpi, 21.4 x 20.0cm; J. Gutt: mailto:[email protected]
Sea-bed photographs (benthos) from the Magellan region (South America) along profile VH1094_1177
No full textPhotos represent approx. 1m**2 each, taken vertically by Hasselblad 500EL/M with two strobes Metz mecablitz 45; Kodak Ektachrome 64; Minolta Dimage Scan Multi II; JPEG compression: 300 dpi, 21.4 x 20.0 cm; J. Gutt: mailto:[email protected]
Sea-bed photographs (benthos) from the Magellan region (South America) along profile VH1094_1125
No full textPhotos represent approx. 1m**2 each, taken vertically by Hasselblad 500EL/M with two strobes Metz mecablitz 45; Kodak Ektachrome 64; Minolta Dimage Scan Multi II; JPEG compression: 300 dpi, 21.4 x 20.0 cm; J. Gutt: mailto:[email protected]
Biophysical studies on bacterial biliverdin-binding photoreceptors
No full textBacterial photoreceptors binding open-chain tetrapyrroles (bilins) as chromophores are related to plant phytochromes (phy) as they are photochromic and their primary photochemistry consists of a Z/E isomerisation around the bilin 15=16 double bond. The chromophore is embedded in all cases within a so-called GAF domain with a typical α/β fold. Different to the canonical plant phys which invariably bind phytochromobilin and switch between a red (R) and a far red (FR) absorbing form, the bacterial bilin-binding photoreceptors exhibit a much wider variety of spectroscopic and functional properties, and bind diverse bilin chromophores, e.g., phycocyanobilin (PCB) and biliverdin (BV). In particular, BV-binding photoreceptors present the most red-shifted spectrum, reaching the near infra-red (NIR) range in the photoactive form. This makes these phytochromes very well suited for biomedical applications (1). Here we report steady-state and time-resolved spectroscopic measurements on selected bacterial BV-binding photoreceptors, representatives for four variations of this photoreceptor family: a. a phy and a bathy-phy from Pseudomonas strains with R/FR photochromism; b. a “bacterio” phytochrome from the fungus Aspergillus nidulans, a eukaryotic organism with photochemistry akin to the Pseudomonas syringae protein; c. a novel phy from Methylobacterium radiotolerans with FR/NIR photochromism. In particular, nanosecond time-resolved absorption spectroscopy has revealed kinetics and spectral features of transient species after photoactivation for both the directions of conversion: the conversions of all these BV-phytochromes in the time range 1 μs – 400 ms seem to be more simple than those from plant phytochromes (oat phyA) or from cyanobacteria (Cph1, CphA) (2)(3), in some cases travelling through only one observable intermediate in the R to FR conversion. References (1) Chernov, K.G. et al. (2017) Chem. Rev. 117 6423-6446. (2) Gärtner, W. and Braslavsky, S.E. (2003) In: Photoreceptors and light signalling, Batschauer, A. (ed.). Compr. Series Photochem. Photobiol. Sci., Vol. 3, Batschauer, A. (ed.), Häder, D.-P. and Jori, G. (series eds.), Royal Soc. Chemistry, Cambridge, UK, pp. 136- 180. (3) Remberg, A. et al. (1997) Biochemistry 36 13389-13395
Kinetics of conversion between Pr and Pfr states in three prototypical bacteriophytochromes
No full textBacteriophytochromes (PphPs) show strong structural similarity to canonical phytochromes, however, they employ as chromophore biliverdin IX instead of phytochromobilin (plant phytochromes) or phycocyanobilin (cyanobacterial phytochromes). This change of chromophore shifts the absorption maxima – compared to those of the plant phytochromes – for both Pr and Pfr state further into the red- / far red range of the spectrum (to 700 and 750 nm, respectively), and thereby makes these phytochromes very well suited for biomedical applications (1). Both photochromic states are reported, however, the dynamics of laser flash-induced conversion between both states has not been studied in detail. Here, we present the kinectics of Pr-to-Pfr conversion (and vice versa) for three prototypal bacteriophytochromes, as such phy1 from Pseudomonas (P.) syringae pv. tomato (PstBphP1), phytochrome from P. aeruginosa (PaBphP), and phytochrome from the fungus Aspergillus nidulans (FphA). Whereas the phytochrome from P. syringae and ist fungal ortholog are formed biosynthetically in the Pr state with absorption maxima at 700 nm, the phytochrome from P. aeruginosa is generated in its Pfr state (750 nm), thus being called a bathy-phytochrome. The conversions between both states of all three bacteriophytochromes in the time range of ca. 1 us up to 20 ms are much more simple than comparable kinetics found for canonical phytochromes from plants (oat phyA) or from cyanobacteria (Cph1, CphA, 2,3). Whereas in the latter proteins a sequence of intermediates can be clearly identified, the bacteriophytochromes run through one intermediate, or in some cases a direct formation of the final photoproduct is immediately observed. 1) Chernov, K.G. et al. (2017) Chem. Rev. 117 6423-6446. 2) Gärtner, W. and Braslavsky, S.E. (2003) In: Photoreceptors and light signalling, Batschauer, A. (ed.). Compr. Series Photochem. Photobiol. Sci., Vol. 3, Batschauer, A. (ed.), Häder, D.-P. and Jori, G. (series eds.), Royal Soc. Chemistry, Cambridge, UK, pp. 136-180. 3) Remberg, A. et al. (1997) Biochemistry 36 13389-13395
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