University of Würzburg

About: University of Würzburg is a education organization based out in Wurzburg, Bayern, Germany. It is known for research contribution in the topics: Population & CAS Registry Number. The organization has 31437 authors who have published 62203 publications receiving 2337033 citations. The organization is also known as: Julius-Maximilians-Universität Würzburg & Würzburg University.

Complementary observables and uncertainty relations.

Abstract: Two observables A and B of an n-level system (ie, a quantum system with n-dimensional state space) are called complementary, if knowledge of the measured value of A implies maximal uncertainty of the measured value of B, and vice versa Such observables exist for all n, but no classification (up to equivalence) of all possible pairs of complementary observables is known except for n\ensuremath{\le}4 Complementary observables are conjectured to satisfy an ``entropic'' uncertainty relation of the strongest possible form This relation has been verified for n\ensuremath{\le}4 by explicit calculations A recent attempt of substantiating the widespread interpretation of uncertainty relations in terms of mutual disturbances between measurements is criticized

A FlAsH-based FRET approach to determine G protein-coupled receptor activation in living cells.

Abstract: Fluorescence resonance energy transfer (FRET) from cyan to yellow fluorescent proteins (CFP/YFP) is a well-established method to monitor protein-protein interactions or conformational changes of individual proteins. But protein functions can be perturbed by fusion of large tags such as CFP and YFP. Here we use G protein-coupled receptor (GPCR) activation in living cells as a model system to compare YFP with the small, membrane-permeant fluorescein derivative with two arsen-(III) substituents (fluorescein arsenical hairpin binder; FlAsH) targeted to a short tetracysteine sequence. Insertion of CFP and YFP into human adenosine A(2A) receptors allowed us to use FRET to monitor receptor activation but eliminated coupling to adenylyl cyclase. The CFP/FlAsH-tetracysteine system gave fivefold greater agonist-induced FRET signals, similar kinetics (time constant of 66-88 ms) and perfectly normal downstream signaling. Similar results were obtained for the mouse alpha(2A)-adrenergic receptor. Thus, FRET from CFP to FlAsH reports GPCR activation in living cells without disturbing receptor function and shows that the small size of the tetracysteine-biarsenical tag can be decisively advantageous.

An environmental bacterial taxon with a large and distinct metabolic repertoire

Abstract: Cultivated bacteria such as actinomycetes are a highly useful source of biomedically important natural products. However, such ‘talented’ producers represent only a minute fraction of the entire, mostly uncultivated, prokaryotic diversity. The uncultured majority is generally perceived as a large, untapped resource of new drug candidates, but so far it is unknown whether taxa containing talented bacteria indeed exist. Here we report the single-cell- and metagenomics-based discovery of such producers. Two phylotypes of the candidate genus ‘Entotheonella’ with genomes of greater than 9 megabases and multiple, distinct biosynthetic gene clusters co-inhabit the chemically and microbially rich marine sponge Theonella swinhoei. Almost all bioactive polyketides and peptides known from this animal were attributed to a single phylotype. ‘Entotheonella’ spp. are widely distributed in sponges and belong to an environmental taxon proposed here as candidate phylum ‘Tectomicrobia’. The pronounced bioactivities and chemical uniqueness of ‘Entotheonella’ compounds provide significant opportunities for ecological studies and drug discovery.

Two functionally distinct alpha2-adrenergic receptors regulate sympathetic neurotransmission.

Abstract: The sympathetic nervous system regulates cardiovascular function by activating adrenergic receptors in the heart, blood vessels and kidney1. α2-Adrenergic receptors are known to have a critical role in regulating neurotransmitter release from sympathetic nerves and from adrenergic neurons in the central nervous system2,3,4,5; however, the individual roles of the three highly homologous α2-adrenergic-receptor subtypes (α2A, α2B, α2C) in this process are not known. We have now studied neurotransmitter release in mice in which the genes encoding the three α2-adrenergic-receptor subtypes were disrupted. Here we show that both the α2A- and α2C-subtypes are required for normal presynaptic control of transmitter release from sympathetic nerves in the heart and from central noradrenergic neurons. α2A-Adrenergic receptors inhibit transmitter release at high stimulation frequencies, whereas the α2C-subtype modulates neurotransmission at lower levels of nerve activity. Both low- and high-frequency regulation seem to be physiologically important, as mice lacking both α2A- and α2C-receptor subtypes have elevated plasma noradrenaline concentrations and develop cardiac hypertrophy with decreased left ventricular contractility by four months of age.

Performance of the ATLAS trigger system in 2015

Abstract: During 2015 the ATLAS experiment recorded 3.8 fb(-1) of proton-proton collision data at a centre-of-mass energy of 13 TeV. The ATLAS trigger system is a crucial component of the experiment, respons ...