1,124 research outputs found
Universal quasiparticle decoherence in hole- and electron-doped high-Tc cuprates
We use angle-resolved photoemission to unravel the quasiparticle decoherence
process in the high- cuprates. The coherent band is highly renormalized,
and the incoherent part manifests itself as a nearly vertical ``dive'' in the
- intensity plot that approaches the bare band bottom. We find that the
coherence-incoherence crossover energies in the hole- and electron-doped
cuprates are quite different, but scale to their corresponding bare bandwidth.
This rules out antiferromagnetic fluctuations as the main source for
decoherence. We also observe the coherent band bottom at the zone center, whose
intensity is strongly suppressed by the decoherence process. Consequently, the
coherent band dispersion for both hole- and electron-doped cuprates is
obtained, and is qualitatively consistent with the framework of Gutzwiller
projection.Comment: 4 pages, 4 figure
Bcl-2 Rescues T Lymphopoiesis in Interleukin-7 Receptor–Deficient Mice
AbstractMice lacking functional IL-7 or IL-7Rα genes are severely deficient in developing thymocytes, T cells, and B cells. IL-7 and IL-7 receptor functions are believed to result in lymphoid cell proliferation and cell maturation, implying signal transduction pathways directly involved in mitogenesis and elaboration of developmentally specific new gene programs. Here, we show that enforced expression of the bcl-2 gene in T-lymphoid cells (by crossing in the Eμ-bcl-2 transgene) in IL-7Rα-deficient mice results in a significant restoration of thymic positive selection and T cell numbers and function. We propose cell survival signals to be the principal function of IL-7R engagement in thymic and T cell development
GEANT4 Simulation of a Cosmic Ray Muon Tomography System with Micro-Pattern Gas Detectors for the Detection of High-Z Materials
Muon Tomography (MT) based on the measurement of multiple scattering of
atmospheric cosmic ray muons traversing shipping containers is a promising
candidate for identifying threatening high-Z materials. Since
position-sensitive detectors with high spatial resolution should be
particularly suited for tracking muons in an MT application, we propose to use
compact micro-pattern gas detectors, such as Gas Electron Multipliers (GEMs),
for muon tomography. We present a detailed GEANT4 simulation of a GEM-based MT
station for various scenarios of threat material detection. Cosmic ray muon
tracks crossing the material are reconstructed with a Point-Of-Closest-Approach
algorithm to form 3D tomographic images of the target material. We investigate
acceptance, Z-discrimination capability, effects of placement of high-Z
material and shielding materials inside the cargo, and detector resolution
effects for such a MT station.Comment: 9 pages, 10 figures, submitted to conference proceedings of SORMA
West 08, Berkele
catena-Poly[[[diaquairon(II)]-μ-pyrazine-2,3-dicarboxylato] dihydrate]
The crystal structure of the title compound, {[Fe(C6H2N2O4)(H2O)2]·2H2O}n, was synthesized by a diffusion method. It has a one-dimensional polymeric chain structure and the chains are further connected into a three-dimensional structure by hydrogen bonds. The FeII ion has a distorted octahedral coordination environment, with two N and two O atoms from the pyrazine-2,3-dicarboxylate ligands in the equatorial plane and with two water molecules in axial positions. The Fe atom lies on a crystallographic centre of symmetry and a twofold rotation axis passes through the pyrazine ring
DSL-Lab: a Low-power Lightweight Platform to Experiment on Domestic Broadband Internet
International audienceThis article presents the design and building of DSL-Lab, a platform to experiment on distributed computing over broadband domestic Internet. Experimental platforms such as PlanetLab and Grid'5000 are promising methodological approaches to study distributed systems. However, both platforms focus on high-end service and network deployments only available on a restricted part of the Internet, leaving aside the possibility for researchers to experiment in conditions close to what is usually available with domestic connection to the Internet. DSL-Lab is a complementary approach to PlanetLab and Grid'5000 to experiment with distributed computing in an environment closer to how Internet appears, when applications are run on end-user PCs. DSL-Lab is a set of 40 low-power and low-noise nodes, which are hosted by participants, using the participants' xDSL or cable access to the Internet. The objective is to provide a validation and experimentation platform for new protocols, services, simulators and emulators for these systems. In this paper, we report on the software design (security, resources allocation, power management) as well as on the first experiments achieved
DSL-Lab: a Platform to Experiment on Domestic Broadband Internet
This report presents the design and building of DSL-Lab, a platform for distributed computing and peer-to-peer experiments over the domestic broadband Internet. Experimental platforms such as PlanetLab and Grid'5000 are promising methodological approaches for studying distributed systems. However, both platforms focus on high-end services and network deployments on only a restricted part of the Internet, and as such, they do not provide experimental conditions of residential broadband networks. DSL-Lab is composed of 40 low-power and noiseless nodes, which are hosted by participants, using users' xDSL or cable access to the Internet. The objective is twofold: 1) to provide accurate and customized measures of availability, activity and performance in order to characterize and tune the models of such resources~; 2) to provide an experimental platform for new protocols, services and applications, as well as a validation tool for simulators and emulators targeting these systems. In this article, we report on the software infrastructure (security, resources allocation, power management) as well as on the first results and experiments achieved
Importance of socioeconomic factors in predicting tooth loss among older adults in Japan: Evidence from a machine learning analysis
Prevalence of tooth loss has increased due to population aging. Tooth loss negatively affects the overall physical and social well-being of older adults. Understanding the role of socio-demographic and other predictors associated with tooth loss that are measured in non-clinical settings can be useful in community-level prevention. We used high-dimensional epidemiological data to investigate important factors in predicting tooth loss among older adults over a 6-year period of follow-up. Data was from participants of 2010 and 2016 waves of the Japan Gerontological Evaluation Study (JAGES). A total of 19,407 community-dwelling functionally independent older adults aged 65 and older were included in the analysis. Tooth loss was measured as moving from a higher number of teeth category at the baseline to a lower number of teeth category at the follow-up. Out of 119 potential predictors, age, sex, number of teeth, denture use, chewing difficulty, household income, employment, education, smoking, fruit and vegetable consumption, community participation, time since last health check-up, having a hobby, and feeling worthless were selected using Boruta algorithm. Within the 6-year follow-up, 3013 individuals (15.5%) reported incidence of tooth loss. People who experienced tooth loss were older (72.9 ± 5.2 vs 71.8 ± 4.7), and predominantly men (18.3% vs 13.1%). Extreme gradient boosting (XGBoost) machine learning prediction model had a mean accuracy of 90.5% (±0.9%). A visual analysis of machine learning predictions revealed that the prediction of tooth loss was mainly driven by demographic (older age), baseline oral health (having 10–19 teeth, wearing dentures), and socioeconomic (lower household income, manual occupations) variables. Predictors related to wide a range of determinants contribute towards tooth loss among older adults. In addition to oral health related and demographic factors, socioeconomic factors were important in predicting future tooth loss. Understanding the behaviour of these predictors can thus be useful in developing prevention strategies for tooth loss among older adults
(3-Chlorophenyl){2-ethoxy-5-[(Z)-hydroxy(phenyl)methylidene]cyclopenta-1,3-dien-1-yl}methanone
The title compound, C21H17ClO3, which crystallizes as one of two possible oxo/hydroxy-fulvene prototropic tautomers, possesses a strong intramolecular O—H⋯O hydrogen bond that closes a seven-membered ring. The dihedral angles between the central five-membered ring and two pendant rings are 55.05 (9) and 44.51 (10)°. The crystal packing is characterized by weak intermolecular C—H⋯O interactions between an H atom of the oxymethylene unit and the carbonyl group of an adjacent molecule, resulting in formation of chains of molecules along the a axis
VCIP135, a novel essential factor for p97/p47-mediated membrane fusion, is required for Golgi and ER assembly in vivo
NSF and p97 are ATPases required for the heterotypic fusion of transport vesicles with their target membranes and the homotypic fusion of organelles. NSF uses ATP hydrolysis to dissociate NSF/SNAPs/SNAREs complexes, separating the v- and t-SNAREs, which are then primed for subsequent rounds of fusion. In contrast, p97 does not dissociate the p97/p47/SNARE complex even in the presence of ATP. Now we have identified a novel essential factor for p97/p47-mediated membrane fusion, named VCIP135 (valosin-containing protein [VCP][p97]/p47 complex-interacting protein, p135), and show that it binds to the p97/p47/syntaxin5 complex and dissociates it via p97 catalyzed ATP hydrolysis. In living cells, VCIP135 and p47 are shown to function in Golgi and ER assembly
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