12,037 research outputs found
Characterization of spatio-temporal epidural event-related potentials for mouse models of psychiatric disorders.
Distinctive features in sensory event-related potentials (ERPs) are endophenotypic biomarkers of psychiatric disorders, widely studied using electroencephalographic (EEG) methods in humans and model animals. Despite the popularity and unique significance of the mouse as a model species in basic research, existing EEG methods applicable to mice are far less powerful than those available for humans and large animals. We developed a new method for multi-channel epidural ERP characterization in behaving mice with high precision, reliability and convenience and report an application to time-domain ERP feature characterization of the Sp4 hypomorphic mouse model for schizophrenia. Compared to previous methods, our spatio-temporal ERP measurement robustly improved the resolving power of key signatures characteristic of the disease model. The high performance and low cost of this technique makes it suitable for high-throughput behavioral and pharmacological studies
Higher real K-theories and topological automorphic forms
Given a maximal finite subgroup G of the nth Morava stabilizer group at a prime p, we address the question: is the associated higher real K-theory EOn a summand of the K(n)-localization of a TAF -spectrum associated to a unitary similitude group of type U(1, n â 1)? We answer this question in the affirmative for p â {2, 3, 5, 7} and n = (p â 1)p(superscript râ1) for a maximal finite subgroup containing an element of order p(superscript r). We answer the question in the negative for all other odd primary cases. In all odd primary cases, we give an explicit presentation of a global division algebra with involution in which the group G embeds unitarily.National Science Foundation (U.S.)Alfred P. Sloan FoundationUnited States. Defense Advanced Research Projects Agency (DARPA
Two-Body B Meson Decays to Ρ and Ρ': Observation of B â Ρ'K
In a sample of 6.6Ă10^6 produced B mesons we have observed decays BâΡâ˛K, with branching fractions B(B^+âΡâ˛K^+) = (6.5_(-1.4)^(+1.5)Âą0.9)Ă10^(-5) and B(B^0âΡâ˛K^0) = (4.7_(-2.0)^(+2.7)Âą0.9)Ă10^(-5). We have searched with comparable sensitivity for 17 related decays to final states containing an Ρ or ΡⲠmeson accompanied by a single particle or low-lying resonance. Our upper limits for these constrain theoretical interpretations of the BâΡâ˛K signal
Particle size effect in methane activation over supported palladium nanoparticles
A synthesis method for producing MgAl oxide supported uniform palladium nanoparticles with varying diameters has been developed. The method consists of reductive-thermal decomposition of a PdMgAl hydrotalcite-like compound, formed via co-precipitation of metal nitrate salts and sodium carbonate. The hydrotalciteâlike precursors were characterized by XRD, TG-MS and SEM, and were found to contain a well-defined crystalline structure and a uniform distribution of all constituent elements. The resulting catalysts were characterized by XRD, TEM, Chemisorption of CO and in situ IR measurements of CO, and were found to consist of partially oxide-embedded Pd nanoparticles with diameters ranging from d = 1.7 to 3.3 nm and correspond dispersions of 67â14%. Furthermore, the particle size was found to be inversely related to Pd loading. The palladium catalysts were studied for methane activation via chemisorption at 200 and 400 °C followed by a temperature programmed surface hydrogenation. The most disperse catalyst (d = 1.7 nm) possessed an intrinsic methane adsorption capacity, which was an order of magnitude larger than that of other catalysts in the series, indicating a strong structure sensitivity in this reaction. Additionally, the methane adsorption capacity of the hydrotalcite-derived Pd catalysts was nearly two orders of magnitude higher than that of catalysts derived through other synthesis pathways such as colloidal deposition or sonochemical reduction
Influence of Precipitation Method on Acid-Base Catalyzed Reactions over Mg-Zr Mixed Oxides
To examine the promotional effect that zirconia has on magnesia in catalysis, mixed oxides were prepared by coprecipitation under controlled-pH conditions or rising-pH conditions. The resulting mixed oxides were characterized by using NH3 and CO2 adsorption microcalorimetry, X-ray diffraction, and scanning electron microscopy. The samples were also tested as catalysts for transesterification of tributyrin with methanol, coupling of acetone, and conversion of ethanol to ethene, ethanal, and butanol. Zirconia promoted the activity of MgO for both transesterification and acetone coupling reactions, presumably by exposing new acidâbase pairs at the surface. During ethanol conversion, however, zirconia promoted the dehydration reactions. Characterization and reactivity results suggest that a Mg-Zr sample prepared by controlled-pH precipitation exposes more ZrO2 than a sample prepared by the rising-pH method
-Decay Spectrum, Response Function and Statistical Model for Neutrino Mass Measurements with the KATRIN Experiment
The objective of the Karlsruhe Tritium Neutrino (KATRIN) experiment is to
determine the effective electron neutrino mass with an
unprecedented sensitivity of (90\% C.L.) by precision electron
spectroscopy close to the endpoint of the decay of tritium. We present
a consistent theoretical description of the electron energy spectrum in
the endpoint region, an accurate model of the apparatus response function, and
the statistical approaches suited to interpret and analyze tritium
decay data observed with KATRIN with the envisaged precision. In addition to
providing detailed analytical expressions for all formulae used in the
presented model framework with the necessary detail of derivation, we discuss
and quantify the impact of theoretical and experimental corrections on the
measured . Finally, we outline the statistical methods for
parameter inference and the construction of confidence intervals that are
appropriate for a neutrino mass measurement with KATRIN. In this context, we
briefly discuss the choice of the energy analysis interval and the
distribution of measuring time within that range.Comment: 27 pages, 22 figures, 2 table
Inclusive Quasi-Elastic Charged-Current Neutrino-Nucleus Reactions
The Quasi-Elastic (QE) contribution of the nuclear inclusive electron
scattering model developed in Nucl. Phys. A627 (1997) 543 is extended to the
study of electroweak Charged Current (CC) induced nuclear reactions, at
intermediate energies of interest for future neutrino oscillation experiments.
The model accounts for, among other nuclear effects, long range nuclear (RPA)
correlations, Final State Interaction (FSI) and Coulomb corrections.
Predictions for the inclusive muon capture in C and the reaction
C near threshold are also given. RPA correlations are
shown to play a crucial role and their inclusion leads to one of the best
existing simultaneous description of both processes, with accuracies of the
order of 10-15% per cent for the muon capture rate and even better for the LSND
measurement.Comment: 31 pages and 14 figures, accepted for publication as a regular
article in Physical Review
Characterization of red wines aged with oak chip in the SĂŁo Francisco Valley, Brazil.
This research aimed to characterize the physicochemical composition of Syrah tropical wines aged with oak chip addition
A pulsed, mono-energetic and angular-selective UV photo-electron source for the commissioning of the KATRIN experiment
The KATRIN experiment aims to determine the neutrino mass scale with a
sensitivity of 200 meV/c^2 (90% C.L.) by a precision measurement of the shape
of the tritium -spectrum in the endpoint region. The energy analysis of
the decay electrons is achieved by a MAC-E filter spectrometer. To determine
the transmission properties of the KATRIN main spectrometer, a mono-energetic
and angular-selective electron source has been developed. In preparation for
the second commissioning phase of the main spectrometer, a measurement phase
was carried out at the KATRIN monitor spectrometer where the device was
operated in a MAC-E filter setup for testing. The results of these measurements
are compared with simulations using the particle-tracking software
"Kassiopeia", which was developed in the KATRIN collaboration over recent
years.Comment: 19 pages, 16 figures, submitted to European Physical Journal
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