308 research outputs found
Design of a multiuser virtual trade fair using a game engine
The current world economic situation makes it necessary to develop new ways of establishing commercial relationships. One possible solution is to explore the advantages of virtual worlds, and for this reason online virtual trade fairs are becoming more popular in the business world. They enable companies to establish a trade relationship with their customers without the need to visit them in person. This is very attractive for exhibitors because it can save them money, which is a priority for many companies today. In this line, this article presents a multiuser virtual trade fair developed using 3D game engine technologys. Users represented by avatars can interact with each other while they are visiting the virtual fair, which has some interactive objects included in the stands to provide information about the exhibitors. This virtual world is accessible online, and visitors only require a plug-in on their computers to be able to enter the virtual world. The game technology makes it possible to obtain a high degree of realism: very real lighting, cast shadows, collision detection, etc. Moreover, the virtual world presented builds the 3D objects automatically. Participants in the trade fair can customize their virtual stand and the application will generate the code necessary for its inclusion in the rendered virtual world.This work was supported by the Spanish Ministry of Science and Technology project TIN2010-21089-C03-03. And also by Bancaja, project P1 1B2007-5
Functional asymmetry and chemical reactivity of CsoR family persulfide sensors
CstR is a persulfide-sensing member of the functionally diverse copper-sensitive operon repressor (CsoR) superfamily. While CstR regulates the bacterial response to hydrogen sulfide (H2S) and more oxidized reactive sulfur species (RSS) in Gram-positive pathogens, other dithiol-containing CsoR proteins respond to host derived Cu(I) toxicity, sometimes in the same bacterial cytoplasm, but without regulatory crosstalk in cells. It is not clear what prevents this crosstalk, nor the extent to which RSS sensors exhibit specificity over other oxidants. Here, we report a sequence similarity network (SSN) analysis of the entire CsoR superfamily, which together with the first crystallographic structure of a CstR and comprehensive mass spectrometry-based kinetic profiling experiments, reveal new insights into the molecular basis of RSS specificity in CstRs. We find that the more N-terminal cysteine is the attacking Cys in CstR and is far more nucleophilic than in a CsoR. Moreover, our CstR crystal structure is markedly asymmetric and chemical reactivity experiments reveal the functional impact of this asymmetry. Substitution of the Asn wedge between the resolving and the attacking thiol with Ala significantly decreases asymmetry in the crystal structure and markedly impacts the distribution of species, despite adopting the same global structure as the parent repressor. Companion NMR, SAXS and molecular dynamics simulations reveal that the structural and functional asymmetry can be traced to fast internal dynamics of the tetramer. Furthermore, this asymmetry is preserved in all CstRs and with all oxidants tested, giving rise to markedly distinct distributions of crosslinked products. Our exploration of the sequence, structural, and kinetic features that determine oxidant-specificity suggest that the product distribution upon RSS exposure is determined by internal flexibility.Fil: Fakhoury, Joseph N. Indiana University; Estados UnidosFil: Zhang, Yifan. Indiana University; Estados UnidosFil: Edmonds, Katherine A. Indiana University; Estados UnidosFil: Bringas, Mauro. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de Investigaciones BioquĂmicas de Buenos Aires. FundaciĂłn Instituto Leloir. Instituto de Investigaciones BioquĂmicas de Buenos Aires; ArgentinaFil: Luebke, Justin L. Indiana University; Estados UnidosFil: Gonzalez Gutierrez, Giovanni. Indiana University; Estados UnidosFil: Capdevila, Daiana Andrea. Indiana University; Estados Unidos. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de Investigaciones BioquĂmicas de Buenos Aires. FundaciĂłn Instituto Leloir. Instituto de Investigaciones BioquĂmicas de Buenos Aires; ArgentinaFil: Giedroc, David Peter. Indiana University; Estados Unido
Search for the Lepton-Number-Violating Decay
A sensitive search for the lepton-number-violating decay has been performed using a sample of hyperons
produced in 800 GeV/ -Cu collisions. We obtain at 90% confidence, improving on the best
previous limit by four orders of magnitude.Comment: 9 pages, 5 figures, to be published in Phys. Rev. Let
Evidence for the Decay Sigma+ -> p mu+ mu-
We report the first evidence for the decay Sigma+ -> p mu+ mu- from data
taken by the HyperCP experiment(E871) at Fermilab. Based on three observed
events, the branching ratio is B(Sigma+ -> p,mu+,mu-) = [8.6 +6.6,-5.4(stat)
+/-5.5(syst)] x 10**-8. The narrow range of dimuon masses may indicate that the
decay proceeds via a neutral intermediate state, Sigma+ -> p P0, P0 -> mu+ mu-,
with a P0 mass of 214.3 +/- 0.5 MeV/c**2 and branching ratio B(Sigma+ -> p P0;
P0 -> mu+ mu-) = [3.1 +2.4,-1.(stat) +/-1.5(syst)] x 10**-8.Comment: As published in PR
Measurement of the Alpha Asymmetry Parameter for the Omega- to Lambda K- Decay
We have measured the alpha parameter of the Omega- to Lambda K- decay using
data collected with the HyperCP spectrometer during the 1997 fixed-target run
at Fermilab. Analyzing a sample of 0.96 million Omega- to Lambda K^-, Lambda to
p pi- decays, we obtain alpha_Omega*alpha_Lambda =
[1.33+/-0.33(stat)+/-0.52(syst)] x 10^{-2}. With the accepted value of
alpha_Lambda, alpha_Omega is found to be [2.07+/-0.51(stat)+/-0.81(syst)] x
10^{-2}.Comment: 5 pages, 4 figures, to be appeared as a Rapid Communication in Phys.
Rev.
Airborne observations of Arctic air mass transformations during the HALO-(AC)3 campaign
The HALO-(AC)3 campaign was conducted in March and April 2022
to investigate warm air intrusions into the Arctic and marine cold air outbreaks. In
coordinated flights over the Arctic, the High Altitude and Long Range Research Aircraft
(HALO), equipped with a remote sensing payload and dropsondes, investigated these
air mass transformations together with the research aircraft Polar 5 and Polar 6. In
this report, we give an overview about the research flights and preliminary results from
projects, which are carried out by employees of the Leipzig Institute for Meteorology
(LIM).Die HALO-(AC)3 Kampagne wurde im MĂ€rz und April 2022
durchgefĂŒhrt, umWarmlufteinbrĂŒche in die Arktis und marine KaltluftausbrĂŒche zu untersuchen.
Das 'High Altitude and Long Range Research Aircraft' (HALO), ausgestattet
mit Instrumenten zur Fernerkundung und Standardmeteorologiesonden, untersuchte
zusammen mit den Forschungsflugzeugen Polar 5 und Polar 6, in koordinierten FlĂŒgen
ĂŒber der Arktis, diese VerĂ€nderungen der Luftmassen. In diesem Bericht wird eine
Ăbersicht ĂŒber die durchgefĂŒhrten ForschungsflĂŒge gegeben und Forschungsprojekte
werden vorgestellt, welche von Mitarbeitern des Leipziger Instituts fĂŒr Meteorologie
(LIM) durchgefĂŒhrt werden
HyperCP: A high-rate spectrometer for the study of charged hyperon and kaon decays
The HyperCP experiment (Fermilab E871) was designed to search for rare
phenomena in the decays of charged strange particles, in particular CP
violation in and hyperon decays with a sensitivity of
. Intense charged secondary beams were produced by 800 GeV/c protons
and momentum-selected by a magnetic channel. Decay products were detected in a
large-acceptance, high-rate magnetic spectrometer using multiwire proportional
chambers, trigger hodoscopes, a hadronic calorimeter, and a muon-detection
system. Nearly identical acceptances and efficiencies for hyperons and
antihyperons decaying within an evacuated volume were achieved by reversing the
polarities of the channel and spectrometer magnets. A high-rate
data-acquisition system enabled 231 billion events to be recorded in twelve
months of data-taking.Comment: 107 pages, 45 Postscript figures, 14 tables, Elsevier LaTeX,
submitted to Nucl. Instrum. Meth.
Search for flavor-changing neutral currents and lepton-family-number violation in two-body D0 decays
Results of a search for the three neutral charm decays, D0 -> mu e, D0 -> mu
mu, and D0 -> e e, are presented. This study was based on data collected in
Experiment 789 at the Fermi National Accelerator Laboratory using 800 GeV/c
proton-Au and proton-Be interactions. No evidence is found for any of the
decays. Upper limits on the branching ratios, at the 90% confidence level, are
obtained.Comment: 28 pages, 18 figures. Submitted to Physical Review
Image informatics strategies for deciphering neuronal network connectivity
Brain function relies on an intricate network of highly dynamic neuronal connections that rewires dramatically under the impulse of various external cues and pathological conditions. Among the neuronal structures that show morphologi- cal plasticity are neurites, synapses, dendritic spines and even nuclei. This structural remodelling is directly connected with functional changes such as intercellular com- munication and the associated calcium-bursting behaviour. In vitro cultured neu- ronal networks are valuable models for studying these morpho-functional changes. Owing to the automation and standardisation of both image acquisition and image analysis, it has become possible to extract statistically relevant readout from such networks. Here, we focus on the current state-of-the-art in image informatics that enables quantitative microscopic interrogation of neuronal networks. We describe the major correlates of neuronal connectivity and present workflows for analysing them. Finally, we provide an outlook on the challenges that remain to be addressed, and discuss how imaging algorithms can be extended beyond in vitro imaging studies
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