18,434 research outputs found
Fluorescent nanodiamonds for FRET-based monitoring of a single biological nanomotor FoF1-ATP synthase
Color centers in diamond nanocrystals are a new class of fluorescence markers
that attract significant interest due to matchless brightness, photostability
and biochemical inertness. Fluorescing diamond nanocrystals containing defects
can be used as markers replacing conventional organic dye molecules, quantum
dots or autofluorescent proteins. They can be applied for tracking and
ultrahigh-resolution localization of the single markers. In addition the spin
properties of diamond defects can be utilized for novel magneto-optical imaging
(MOI) with nanometer resolution. We develop this technique to unravel the
details of the rotary motions and the elastic energy storage mechanism of a
single biological nanomotor FoF1-ATP synthase. FoF1-ATP synthase is the enzyme
that provides the 'chemical energy currency' adenosine triphosphate, ATP, for
living cells. The formation of ATP is accomplished by a stepwise internal
rotation of subunits within the enzyme. Previously subunit rotation has been
monitored by single-molecule fluorescence resonance energy transfer (FRET) and
was limited by the photostability of the fluorophores. Fluorescent nanodiamonds
advance these FRET measurements to long time scales.Comment: 10 pages, 4 figure
Classification and Recovery of Radio Signals from Cosmic Ray Induced Air Showers with Deep Learning
Radio emission from air showers enables measurements of cosmic particle
kinematics and identity. The radio signals are detected in broadband Megahertz
antennas among continuous background noise. We present two deep learning
concepts and their performance when applied to simulated data. The first
network classifies time traces as signal or background. We achieve a true
positive rate of about 90% for signal-to-noise ratios larger than three with a
false positive rate below 0.2%. The other network is used to clean the time
trace from background and to recover the radio time trace originating from an
air shower. Here we achieve a resolution in the energy contained in the trace
of about 20% without a bias for of the traces with a signal. The
obtained frequency spectrum is cleaned from signals of radio frequency
interference and shows the expected shape.Comment: 20 pages, 13 figures, resubmitted to JINS
Performance of the CMS Pixel Detector at an upgraded LHC
The CMS experiment will include a pixel detector for pattern recognition and
vertexing. It will consist of three barrel layers and two endcaps on each side,
providing three space-points up to a pseudoraditity of 2.1. Taking into account
the expected limitations of its performance in the LHC environment an 8-9 layer
pixel detector for an upgraded LHC is discussed.Comment: Contribution to the 10th European Symposium on Semiconductor
Detectors, June 12 - 16, 2005 in Wildbad Kreuth, Germany. 6 pages, 4 figures,
1 table. Referee's comments implemente
Universal deformation rings of modules for algebras of dihedral type of polynomial growth
Let k be an algebraically closed field, and let \Lambda\ be an algebra of
dihedral type of polynomial growth as classified by Erdmann and Skowro\'{n}ski.
We describe all finitely generated \Lambda-modules V whose stable endomorphism
rings are isomorphic to k and determine their universal deformation rings
R(\Lambda,V). We prove that only three isomorphism types occur for
R(\Lambda,V): k, k[[t]]/(t^2) and k[[t]].Comment: 11 pages, 2 figure
Fiber optic wavelength division multiplexing: Principles and applications in telecommunications and spectroscopy
Design and fabrication tradeoffs of wavelength division multiplexers are discussed and performance parameters are given. The same multiplexer construction based on prism gratings has been used in spectroscopic applications, in the wavelength region from 450 to 1600 nm. For shorter wavelengths down to 200 nm, a similar instrument based on longer fibers (500 to 1000 micrometer) has been constructed and tested with both a fiber array and a photodiode detector array at the output
Building CMS Pixel Barrel Detectur Modules
For the barrel part of the CMS pixel tracker about 800 silicon pixel detector
modules are required. The modules are bump bonded, assembled and tested at the
Paul Scherrer Institute. This article describes the experience acquired during
the assembly of the first ~200 modules.Comment: 5 pages, 7 figures, Vertex200
Ethnicity, voter alignment and political party affiliation - an African case: Zambia
Conventional wisdom holds that ethnicity provides the social cleavage for voting behav-iour and party affiliation in Africa. Because this is usually inferred from aggregate data of national election results, it might prove to be an ecological fallacy. The evidence based on individual data from an opinion survey in Zambia suggests that ethnicity matters for voter alignment and even more so for party affiliation, but it is certainly not the only factor. The analysis also points to a number of qualifications which are partly methodology-related. One is that the degree of ethnic voting can differ from one ethno-political group to the other depending on various degrees of ethnic mobilisation. Another is that if smaller eth-nic groups or subgroups do not identify with one particular party, it is difficult to find a significant statistical correlation between party affiliation and ethnicity - but that does not prove that they do not affiliate along ethnic lines.Wahlverhalten und Mitgliedschaft in politischen Parteien Afrikas ist nur wenig untersucht worden. Gewöhnlich wird argumentiert, dass Ethnizität als soziale Konfliktlinie das Wahlverhalten und die Parteienmitgliedschaft strukturiert. Da dieses Argument auf hoch aggregierten Wahldaten beruht, kann hier ein ökologischer Fehlschuss vorliegen. Die vorliegende Analyse beruht deshalb auf individuellen Umfragedaten aus Sambia. Das Ergebnis ist, dass Ethnizität tatsächlich eine Rolle für das Wahlverhalten und die Parteienmitgliedschaft spielt, aber keineswegs den einzigen Erklärungsfaktor darstellt. Die Analyse offenbart zudem eine Reihe von Einschränkungen und Qualifizierungen, die teilweise methodischer Natur sind. Eine ist, dass ethnisches Wahlverhalten und Parteienmitgliedschaft von einer ethnischen Gruppe zur anderen unterschiedlich ist, dass, wenn sich kleinere ethnische Gruppen oder Untergruppen mit keiner Partei identifizieren, es schwierig wird, statistisch signifikante Korrelationen zu finden - was indessen noch nicht beweist, dass Ethnizität keine Rolle spielt
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