35 research outputs found
Super-Resolution Imaging of C-Type Lectin and Influenza Hemagglutinin Nanodomains on Plasma Membranes Using Blink Microscopy
AbstractDendritic cells express DC-SIGN, a C-type lectin (CTL) that binds a variety of pathogens and facilitates their uptake for subsequent antigen presentation. DC-SIGN forms remarkably stable microdomains on the plasma membrane. However, inner leaflet lipid markers are able to diffuse through these microdomains suggesting that, rather than being densely packed with DC-SIGN proteins, an elemental substructure exists. Therefore, a super-resolution imaging technique, Blink Microscopy (Blink), was applied to further investigate the lateral distribution of DC-SIGN. Blink indicates that DC-SIGN, another CTL (CD206), and influenza hemagglutinin (HA) are all localized in small (∼80 nm in diameter) nanodomains. DC-SIGN and CD206 nanodomains are randomly distributed on the plasma membrane, whereas HA nanodomains cluster on length scales up to several microns. We estimate, as a lower limit, that DC-SIGN and HA nanodomains contain on average two tetramers or two trimers, respectively, whereas CD206 is often nonoligomerized. Two-color Blink determined that different CTLs rarely occupy the same nanodomain, although they appear colocalized using wide-field microscopy. What to our knowledge is a novel domain structure emerges in which elemental nanodomains, potentially capable of binding viruses, are organized in a random fashion; evidently, these nanodomains can be clustered into larger microdomains that act as receptor platforms for larger pathogens like yeasts
Polarised Quark Distributions in the Nucleon from Semi-Inclusive Spin Asymmetries
We present a measurement of semi-inclusive spin asymmetries for positively
and negatively charged hadrons from deep inelastic scattering of polarised
muons on polarised protons and deuterons in the range 1
GeV. Compared to our previous publication on this subject, with the new
data the statistical errors have been reduced by nearly a factor of two.
From these asymmetries and our inclusive spin asymmetries we determine the
polarised quark distributions of valence quarks and non-strange sea quarks at
=10 GeV. The polarised valence quark distribution, , is positive and the polarisation increases with . The polarised
valence quark distribution, , is negative and the non-strange
sea distribution, , is consistent with zero over the measured
range of . We find for the first moments , and
, where we assumed
. We also determine for the first time the
second moments of the valence distributions .Comment: 17 page
Polarised quark distributions in the nucleon from semi-inclusive spin asymmetries
We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range 1~GeV. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at =10~GeV. The polarised valence quark distribution, , is positive and the polarisation increases with . The polarised valence quark distribution, , is negative and the non-strange sea distribution, , is consistent with zero over the measured range of . We find for the first moments , and , where we assumed . We also determine for the first time the second moments of the valence distributions .We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range 1 GeV. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at =10 GeV. The polarised valence quark distribution, , is positive and the polarisation increases with . The polarised valence quark distribution, , is negative and the non-strange sea distribution, , is consistent with zero over the measured range of . We find for the first moments , and , where we assumed . We also determine for the first time the second moments of the valence distributions .We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range 1 GeV. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at =10 GeV. The polarised valence quark distribution, , is positive and the polarisation increases with . The polarised valence quark distribution, , is negative and the non-strange sea distribution, , is consistent with zero over the measured range of . We find for the first moments , and , where we assumed . We also determine for the first time the second moments of the valence distributions .We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range 1 GeV. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at =10 GeV. The polarised valence quark distribution, , is positive and the polarisation increases with . The polarised valence quark distribution, , is negative and the non-strange sea distribution, , is consistent with zero over the measured range of . We find for the first moments , and , where we assumed . We also determine for the first time the second moments of the valence distributions .We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range 1 GeV. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at =10 GeV. The polarised valence quark distribution, , is positive and the polarisation increases with . The polarised valence quark distribution, , is negative and the non-strange sea distribution, , is consistent with zero over the measured range of . We find for the first moments , and , where we assumed . We also determine for the first time the second moments of the valence distributions .We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range 0.0031 GeV 2 . Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at Q 2 =10 GeV 2 . The polarised u valence quark distribution, Δu v ( x ), is positive and the polarisation increases with x . The polarised d valence quark distribution, Δd v ( x ), is negative and the non-strange sea distribution, Δ q ̄ (x) , is consistent with zero over the measured range of x . We find for the first moments ∫ 0 1 Δu v (x) d x=0.77±0.10±0.08 , ∫ 0 1 Δd v (x) d x=−0.52±0.14±0.09 and ∫ 0 1 Δ q ̄ (x) d x=0.01±0.04±0.03 , where we assumed Δ u ̄ (x)=Δ d ̄ (x) . We also determine for the first time the second moments of the valence distributions ∫ 0 1 xΔq v (x) d x
Spin asymmetries A1 and structure functions g1 of the proton and the deuteron from polarized high energy muon scattering.
Adeva B, Akdogan T, Arik E, et al. Spin asymmetries A(1) and structure functions g(1) of the proton and the deuteron from polarized high energy muon scattering. Phys.Rev. D. 1998;58(11): 112001.We present the final results of the spin asymmetries A(1) and the spin structure functions g(1) of the proton and the deuteron in the kinematic range 0.0008 < x < 0.7 and 0.2 < Q(2) < 100 GeV2. For the determination of A(1), in addition to the usual method which employs inclusive scattering events and includes a large radiative background at low x, we use a new method which minimizes the radiative background by selecting events with at least one hadron as well as a muon in the final state. We find that this hadron method gives smaller errors for x < 0.02, so it is combined with the usual method to provide the optimal set of results. [S0556-2821(98)07017-9]
Numerical solution of three-dimensional rectangular submerged jets with the evidence of the undisturbed region of flow
Experimental reports SANS-1 1998. Jahresbericht der SANS-1-Anlage 1998
The instrument SANS-1 at the Geesthacht Neutron Facility GeNF was used for scattering experiments in 1998 at 237 of 287 days of reactor operation. The utilisation was shared between the in-house R and D program (V 3.3.01.G.01) and user groups from different universities. These measurements were performed and analysed either by guest scientists or GKSS staff. The focus of the work in 1998 at the experiment SANS-1 was the structural investigation of hydrogen containing substances such as biological macromolecules (ribosomes), molecules which are important in the fields of environmental research (refractoric organic substances) and technical chemistry (surfactants, micelles). (orig.)SIGLEAvailable from TIB Hannover: RA 3251(99/E/12) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
xD-Reflect - >Multidimensional Reflectometry for Industry> a research project of the European Metrology Research Program (EMRP)
Andreas Hope et al.; 12th International Conference, Otaniemi, Espoo, Helsinki (Finland), 24-27 June, 2014; http://newrad2014.aalto.fi/The general objective of the xD-Reflect research project is to meet the demands from European industry to measure the overall macroscopic appearance of modern surfaces by developing and improving methods for optical measurements which correlate with the visual sensation being evoked. In particular, the project deals with different attributes of dedicated artefacts, like >Goniochromatism>, >Gloss> and >Fluorescence> properties, which will be investigated in three main work packages. Two additional transversal work packages reinforce the structure: >Modelling and Data Analysis> with the objective to give an irreducible set of calibration schemes and handling methods and >Visual Perception>, which will produce perception scales for the different visual attributes.This work has been carried out within EMRP project IND52 >Multidimensional Reflectometry for Industry>. The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union.Peer Reviewe
Lokalisation der ribosomalen Proteine L2, L14 und L24 des E. coli-Ribosoms mit Hilfe der Kernspinkontrastvariation
Ribosomen sind Ribonukleinsaeure-Protein-Komplexe, die in allen lebenden Organismen die Proteinsynthese durchfuehren, einen der zentralen Schritte bei der Umsetzung der genetischen Information von der DNA zu den Proteinen. Im Rahmen dieser Arbeit wurden die Proteine L2, L14 und L24 in der 50S-Untereinheit und des Proteins L2 im 70S-Ribosom des E. coli-Bakteriums mit Hilfe der Kernspinkontrastvariation lokalisiert. Grundlage dieser Methode ist ein durch Isotopensubstitution erzeugter Kontrast, der durch die Streuung von polarisierten Neutronen an polarisierten Wasserstoffspins der Probe bis zu einem Faktor von drei noch verstaerkt wird. Um zusaetzliche Informationen ueber die In situ-Form der Proteine zu erhalten, wurde bei der Positionsbestimmung neben dem bislang verwendeten Einkugelmodell die Form des Labels durch Zwei- bzw. Dreikugelmodelle angenaehert. Im Rahmen der Kartografierung der 50S-Untereinheit des E. coli-Ribosoms ist es erstmalig gelungen, das Protein L24 zu lokalisieren. Die Kenntnis seiner Position ist fuer das Verstaendnis des Aufbauvorgangs der 50S-Untereinheit von grossem Interesse, da es sich um eines der Initiatorproteine dieses Prozesses handelt. Mit der Lokalisation des Proteins L14, eines der am besten konservierten Proteine im Ribosom ueberhaupt, ergeben sich neue Ansatzpunkte zur Erklaerung seiner bislang unbekannten Funktion. Die Lokalisation des Proteins L2, einem Kandidaten fuer den zentralen Schritt der Proteinsynthese sowohl in der 50S-Untereinheit als auch erstmalig im gesamten 70S-Ribosom, gibt zusaetzlich die Moeglichkeit, um Konformationsaenderungen bei der Assoziation der Untereinheiten festzustellen. (orig.)Ribosomes are ribonucleo-protein complexes, which are the site of the protein synthesis, one of the most important steps during the translation of the genetic code from the DNA to the proteins. The proteins L2, L14 and L24 in the 50S subunit and the protein L2 in the 70S ribosome of the E. coli bacterium were localised by means of nuclear spin contrast variation. The contrast created by isotopic substitution is increased by almost a factor of three provided that polarised neutrons are scattered by polarised hydrogen spins of the sample. To get additional information about the in situ structure of the proteins the shapes were described by a two or three sphere model. Within the project of mapping the 50S subunit of the E. coli ribosome the protein L24 is localised for the first time. L24 is one of the initiator protein for the assembly of the 50S subunit therefore the knowledge of the position is of great interest for the understanding of this process. With the localisation of the protein L14, which is one of the most conserved protein in the ribosome, new hints are given in respect of the protein function which was until now unknown. The localisation of the protein L2, which is one of the candidates of the area of the central step in protein synthesis was done both in the 50S subunit and in the whole 70S ribosome. This allows to investigate conformational changes during the association of the subunits. (orig.)Available from TIB Hannover: RA 3251(99/E/37) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman