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Institution

University of Konstanz

EducationKonstanz, Baden-Württemberg, Germany
About: University of Konstanz is a education organization based out in Konstanz, Baden-Württemberg, Germany. It is known for research contribution in the topics: Population & Visualization. The organization has 12115 authors who have published 27401 publications receiving 951162 citations. The organization is also known as: University of Constance & Universität Konstanz.


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Journal ArticleDOI
TL;DR: The application of an inhibitor of photosynthesis indicated that the light-induced expression of these carotenoid biosynthesis genes may be under photosynthetic control.
Abstract: Astaxanthin is a high-value carotenoid used as a pigmentation source in fish aquaculture. In addition, a beneficial role of astaxanthin as a food supplement for humans is becoming evident. The unicellular green alga Haematococcus pluvialis seems to be a suitable source for natural astaxanthin. Astaxanthin accumulation in H. pluvialis occurs in response to environmental stress such as high light and salt stress. Here, the isolation of the H. pluvialis carotenoid biosynthesis gene phytoene synthase is reported. Furthermore, the expression of phytoene synthase and carotenoid hydroxylase, two key enzymes in astaxanthin biosynthesis, was investigated at the transcriptional level. The application of environmental stress resulted in increased steady-state mRNA levels of both genes. High-light intensity led to a transient increase in carotenoid hydroxylase mRNA followed by moderate astaxanthin accumulation. In contrast, salt stress in combination with high light resulted in a sustained increase in both transcripts. The addition of compounds inducing reactive oxygen species did not influence transcript levels of phytoene synthase and carotenoid hydroxylase. The application of an inhibitor of photosynthesis, 3-(3, 4-dichlorophenyl)-1,1-dimethylurea, indicated that the light-induced expression of these carotenoid biosynthesis genes may be under photosynthetic control.

218 citations

Journal ArticleDOI
TL;DR: A thorough understanding of the regulation of its population dynamics provides the key for predictions of the response of freshwater planktonic food webs to global climate change.
Abstract: The timing of various plankton successional events in Lake Constance was tightly coupled to a large- scale meteorological phenomenon, the North Atlantic Oscillation (NAO). A causal chain of meteorological, hydrological, and ecological processes connected the NAO as well as winter and early spring meteorological conditions to planktonic events in summer leading to a remarkable memory of climatic effects lasting over al- most half a year. The response of Daphnia to meteoro- logical forcing was most probably a direct effect of al- tered water temperatures on daphnid growth and was not mediated by changes in phytoplankton concentrations. High spring water temperatures during "high-NAO years" enabled high population growth rates, resulting in a high daphnid biomass as early as May. Hence, a critical Daphnia biomass to suppress phytoplankton was reached earlier in high-NAO years yielding an early and longer- lasting clear-water phase. Finally, an earlier summer de- cline of Daphnia produced in a negative relationship be- tween Daphnia biomass in July and the NAO. Meteoro- logical forcing of the seasonal plankton dynamics in Lake Constance included simple temporal shifts of pro- cesses and successional events, but also complex chang- es in the relative importance of different mechanisms. Since Daphnia plays an important role in plankton suc- cession, a thorough understanding of the regulation of its population dynamics provides the key for predictions of the response of freshwater planktonic food webs to glob- al climate change.

218 citations

Journal ArticleDOI
01 Oct 2004-Farmaco
TL;DR: A series of 1,5-dialkyl-1,2,4-triazole derivatives of acetic acid alkylidene hydrazides, evaluated in a series of human cancer cell in cultures and none have shown activity except 25 which exhibited remarkable activity against nine cancer types.
Abstract: A series of 1,5-dialkyl-1,2,4-triazole derivatives of acetic acid alkylidene hydrazides 8-12, the acid 13, 1,5-dialkyl-3-(5-mercapto-4-N-aryl-1H-[1,2,4]-triazol-3-ylmethylene)-1H-[1,2,4] triazoles 14-16, their 1,3,4-oxadiazole analogues 17-21, as well as the 1,2,4-triazolo-indoles 25 and 27 were prepared. The Z/E conformations of some acetic acid alkylidene derivatives were studied by NMR spectroscopy. Most of the target compounds were evaluated in a series of human cancer cell in cultures and none have shown activity except 25 which exhibited remarkable activity against nine cancer types. No in vitro antiviral activity against HIV-1, HIV-2, HSV-1, HSV-2, SV, CV-B4, RSV, P3V, RV, SinV, PTV has been found for all the synthesized compounds.

217 citations

Journal ArticleDOI
TL;DR: It is believed that LBP-chylomicron complexes may be part of a local defense mechanism of the intestine against translocated bacterial toxin.
Abstract: Chylomicrons have been shown to protect against endotoxin-induced lethality. LPS-binding protein (LBP) is involved in the inactivation of bacterial toxin by lipoproteins. The current study examined the interaction among LBP, chylomicrons, and bacterial toxin. LBP was demonstrated to associate with chylomicrons and enhance the amount of LPS binding to chylomicrons in a dose-dependent fashion. In addition, LBP accelerated LPS binding to chylomicrons. This LBP-induced interaction of LPS with chylomicrons prevented endotoxin toxicity, as demonstrated by reduced cytokine secretion by PBMC. When postprandial circulating concentrations of chylomicrons were compared with circulating levels of low density lipoprotein, very low density lipoprotein, and high density lipoprotein, chylomicrons exceeded the other lipoproteins in LPS-inactivating capacity. Furthermore, highly purified lipoteichoic acid, an immunostimulatory component of Gram-positive bacteria, was detoxified by incubation with LBP and chylomicrons. In conclusion, our results indicate that LBP associates with chylomicrons and enables chylomicrons to rapidly bind bacterial toxin, thereby preventing cell activation. Besides a role in the detoxification of bacterial toxin present in the circulation, we believe that LBP-chylomicron complexes may be part of a local defense mechanism of the intestine against translocated bacterial toxin.

217 citations

Proceedings ArticleDOI
30 Jun 2017
TL;DR: KoNViD-1k is reported on, a subjectively annotated VQA database consisting of 1,200 public-domain video sequences, fairly sampled from a large public video dataset, YFCC100m, aimed at ‘in the wild’ authentic distortions.
Abstract: Subjective video quality assessment (VQA) strongly depends on semantics, context, and the types of visual distortions. Currently, all existing VQA databases include only a small number of video sequences with artificial distortions. The development and evaluation of objective quality assessment methods would benefit from having larger datasets of real-world video sequences with corresponding subjective mean opinion scores (MOS), in particular for deep learning purposes. In addition, the training and validation of any VQA method intended to be ‘general purpose’ requires a large dataset of video sequences that are representative of the whole spectrum of available video content and all types of distortions. We report our work on KoNViD-1k, a subjectively annotated VQA database consisting of 1,200 public-domain video sequences, fairly sampled from a large public video dataset, YFCC100m. We present the challenges and choices we have made in creating such a database aimed at ‘in the wild’ authentic distortions, depicting a wide variety of content.

217 citations


Authors

Showing all 12272 results

NameH-indexPapersCitations
Robert E. W. Hancock15277588481
Lloyd J. Old152775101377
Andrew White1491494113874
Stefanie Dimmeler14757481658
Rudolf Amann14345985525
Niels Birbaumer14283577853
Thomas P. Russell141101280055
Emmanuelle Perez138155099016
Shlomo Havlin131101383347
Bruno S. Frey11990065368
Roald Hoffmann11687059470
Michael G. Fehlings116118957003
Yves Van de Peer11549461479
Axel Meyer11251151195
Manuela Campanelli11167548563
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202360
2022202
20211,361
20201,299
20191,166
20181,082