1,243 research outputs found
Propagation of chaos for rank-based interacting diffusions and long time behaviour of a scalar quasilinear parabolic equation
We study a quasilinear parabolic Cauchy problem with a cumulative
distribution function on the real line as an initial condition. We call
'probabilistic solution' a weak solution which remains a cumulative
distribution function at all times. We prove the uniqueness of such a solution
and we deduce the existence from a propagation of chaos result on a system of
scalar diffusion processes, the interactions of which only depend on their
ranking. We then investigate the long time behaviour of the solution. Using a
probabilistic argument and under weak assumptions, we show that the flow of the
Wasserstein distance between two solutions is contractive. Under more stringent
conditions ensuring the regularity of the probabilistic solutions, we finally
derive an explicit formula for the time derivative of the flow and we deduce
the convergence of solutions to equilibrium.Comment: Stochastic partial differential equations: analysis and computations
(2013) http://dx.doi.org/10.1007/s40072-013-0014-
Oxide Heterostructures from a Realistic Many-Body Perspective
Oxide heterostructures are a new class of materials by design, that open the
possibility for engineering challenging electronic properties, in particular
correlation effects beyond an effective single-particle description. This short
review tries to highlight some of the demanding aspects and questions,
motivated by the goal to describe the encountered physics from first
principles. The state-of-the-art methodology to approach realistic many-body
effects in strongly correlated oxides, the combination of density functional
theory with dynamical mean-field theory, will be briefly introduced. Discussed
examples deal with prominent Mott-band- and band-band-insulating type of oxide
heterostructures, where different electronic characteristics may be stabilized
within a single architectured oxide material.Comment: 19 pages, 9 figure
Amygdaloid Kindling and the GABA System
The effect of increased brain GABA levels on fully kindled amygdala seizures was investigated in Long-Evans rats. The newly synthesized GABA-transaminase inhibitor, -Î-acetylenic GABA (GAG) administered on four consecutive days (100 mg/kg, followed by 50 mg/kg, i.p.) was found to either significantly reduce, or eliminate entirely, the behavioral seizures normally produced by amygdala stimulation. The effect is seen after the first injection of GAG although its magnitude was greater on subsequent days. Behavioral seizures reappeared 2 to 3 days after termination of GAG treatment. The duration of electrographic seizures (self-sustained amygdala after-discharge) was either unchanged or greater on the first day of GAG treatment, but was briefer on subsequent days. The duration of afterdischarges returned to normal levels 1 to 2 days earlier than the behavioral seizures after the termination of GAG. Picrotoxin (1.5-2 mg/kg, i.p.) did not antagonize either electrographic or behavioral effects of inhibition produced with GAG. Electrical stimulation of amygdala delivered during the initial sedation stage induced by picrotoxin resulted in further regression of kindled seizures in the majority of animals. Although in doses employed, GAG alleviates amygdaloid-kindled seizures its use requires caution in view of its ability to reduce arousal level. RĂSUMĂ L'effet de l'ĂlĂvation des taux cĂrĂbraux de GABA sur les crises amygdaliennes par effet d'embrasement complet a ĂtĂĂtudiĂ chez des rats Long-Evans. l'injection pendant 4 jours consĂcutifs de 100 mg/kg suivis de 50 mg/kg i.p. d'un inhibiteur de la GABA. Transaminase nouvellement synthĂtisĂ (Î-acetylenic GABA ou GAG) a significativement rĂduit ou mĂme supprimĂ les crises normalement provoquĂes par la stimulation amygdalienne. l'effet est observĂ aprĂs la premiere injection de GAG, mais son importance s'accroit les jours suivants. Les crises rĂapparaissent 2 ou 3 jours aprĂs la fin du traitement au GAG. Du point de vue Ălectrographique, la durĂe de la postdĂcharge amygdalienne autoentretenue est inchingĂe ou accrue le premier jour du traitement, mais elle diminue les jours suivants pour retourner Ă la normale un ou deux jours avant que les crises ne rĂapparaissent aprĂs la fin de ('administration du GAG. l'injection de picrotoxine (1.5-2 mg/kg i.p.) ne s'oppose pas aux effets inhibiteurs du GAG sur les crises ou leur accompagnement EEG. La stimulation Ălectrique de l'amygdala pendant l'Ătape sĂdative initiate induite par la picrotoxine provoque une rĂgression supplĂmentaire des crises d'embrasement chez la majoritĂ des animaux. Bien que, aux doses utilisĂes, le GAG attĂnue les crises amyg-daliennes d'embrasement, son utilisation nĂcessite des prĂcautions compte tenu de sa tendance Ă rĂduire le niveau d'Ăveil. RESUMEN En ratas Long-Evans se ha investigado el efecto del aumento de los niveles cerebrales de GABA, sobre los ataques originados en la amĂgdala totalmente condicionada, (Kindling). El recientemente sintetizado in-hibidor de la GABA transaminasa, Î-acetilĂnico GABA (GAG), redujo significativamente o eliminĂ totalmente las crisis de comportamiento que habitualmente se producen con la estimulaciĂn de la amĂgdala. El efecto se observa despuĂs de la primera in-yecciĂn de GAG pero su magnitud aumentĂ en dias subsiguientes. Las crisis de comportamiento reaparecieron a los 2â3 dĂas de la interrupciĂn del tratamiento con GAG. La duraciĂn de los ataques electrogrĂficos (perservaciĂn de la post-descarga de la amigdala) no se modificĂ, o incluso aumentĂ, en el primer dia de la administraciĂn de GAG pero se redujo en los dias siguientes. La duraciĂn de las post-descargas volviĂ a sus niveles normales 1 o 2 dias antes que la reapariciĂn de las crisis de comportamiento una vez terminado el tratamiento con GAG. La picrotoxina (1.5-2 mg/kg, i.p.) no antagonizĂ los efectos inhibitorios producidos por el GAG sobre el electroencefalograma o las crisis de comportamiento. La estimulaciĂn elĂctrica sobre la amĂgdala, aplicada durante la fase de sedaciĂn inicial inducida por la picrotoxina, condujo a una regresiĂn aĂn mĂs intensa de las crisis condicionadas, en la mayorĂa de los animales. A pesar de que, con las dosis utilizadas, el GAG alivia las crisis de la amĂgdala previamente condicionada, se requiere gran precauciĂn en su utilizaciĂn en vista de su propiedad de reducir el nivel del despertar. ZUSAMMENFASSUNG Die Wirkung erhĂhter GABA-Spiegel des Gehirns auf AmygdalonkrĂmpfe nach Kindling wurden bei Long-Evans-Ratten untersucht. Der neuerdings synthetisierte GABA-TYansaminasen-Inhibitor, Gamma-Acetylen-GABA (GAG) wurde an 4 aufeinander-folgenden Tagen in einer Dosis von 100 mg/kg und anschlieliend 50 mg/kg i.p. verabfolgt. Er reduzierte entweder signifikant oder eliminierte vĂllig die anfalls-weisen VerhaltensĂnderungen, die normalerweise durch Stimulation des Amygdalon produziert wurden. Die Wirkung ist nach der Erstinjektion des GAG zu beobachten, obgleich ihr AusmaĂ an folgenden Tagen grĂĂer war. Die VerhaltensanfĂlle kamen 2 bis 3 Tagen nach Beendigung der GAG-Behandlung wieder. Die Dauer der elektrographischen AnfĂlle (sich selbst un-terhaltende Amydalonnachentladungen) blieben entweder gleich oder sie wurden grĂĂer am 1. Tag der GAG-Behandlung, wurden aber kĂrzer an folgenden Tagen. Die Dauer der Nachentladungen nor-malisierte sich 1 bis 2 Tage frĂher als die VerhaltensanfĂlle nach Beendigung des GAG verschwanden. Picrotoxin (1.5 bis 2 mg/kg i.p.) wirken nicht als Antagonist gegenĂber der durch GAG produzierten Hemmung der elektrographischen-oder Verhalten-seffekte. Die elektrische Stimulierung des Amygdalon wĂhrend der initialen Sedierung nach Picrotoxin ver-ursachte bei der Mehrzahl der Tiere einen weiteren RĂckgang der durch Kindling entstandenen AnfĂlle. Obgleich das GAG in den verwandten Dosen, die durch Kindling des Amygdalon erzeugten KrĂmpfe leichter ablaufen lUĂt, erfordert seine Anwendung Vorsicht hinsichtlich seiner FĂhigkeit, das Erreg-barkeitsniveau zu senken.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66112/1/j.1528-1157.1980.tb04058.x.pd
Effects of the Template Composition and Coating on the Photoluminescence Properties of ZnS:Mn Nanoparticles
Mn-doped ZnS nanocrystals based on low dopant concentrations (0â2%) and coated with a shell of Zn(OH)2 have been prepared via soft template and precipitation reaction. The results indicate that the ZnS:Mn nanocrystal is cubic zinc blende structure and its diameter is 3.02 nm as demonstrated by XRD. Measured by TEM, the morphology of nanocrystals is a spherical shape, and their particle size (3â5 nm) is similar to that of XRD results. Photoluminescence spectra under ultraviolet region shows that the volume ratio of alcohol to water in the template has a great effect on the luminescence properties of ZnS:Mn particles. Compared with unpassivated ZnS:Mn nanocrystals, ZnS:Mn/Zn(OH)2 core/shell nanocrystal exhibits much improved luminescence and higher absolute quantum efficiency. Meanwhile, we simply explore the formation mechanism of ZnS:Mn nanocrystals in alcohol and water system and analyze the reason why alcohol and water cluster structures can affect the luminescent properties of nanoparticle
Herlyn-werner-wunderlich syndrome: MRI findings, radiological guide (two cases and literature review), and differential diagnosis
<p>Abstract</p> <p>Background</p> <p>Herlyn-Werner-Wunderlich (HWW) syndrome is a very rare congenital anomaly of the urogenital tract involving MĂŒllerian ducts and Wolffian structures, and it is characterized by the triad of didelphys uterus, obstructed hemivagina and ipsilateral renal agenesis. It generally occurs at puberty and exhibits non-specific and variable symptoms with acute or pelvic pain shortly following menarche, causing a delay in the diagnosis. Moreover, the diagnosis is complicated by the infrequency of this syndrome, because MĂŒllerian duct anomalies (MDA) are infrequently encountered in a routine clinical setting.</p> <p>Cases presentation</p> <p>two cases of HWW syndrome in adolescents and a differential diagnosis for one case of a different MDA, and the impact of magnetic resonance (MR) imaging technology to achieve the correct diagnosis.</p> <p>Conclusions</p> <p>MR imaging is a very suitable diagnostic tool in order to perform the correct diagnosis of HWW syndrome.</p
Production of phi mesons at mid-rapidity in sqrt(s_NN) = 200 GeV Au+Au collisions at RHIC
We present the first results of meson production in the K^+K^- decay channel
from Au+Au collisions at sqrt(s_NN) = 200 GeV as measured at mid-rapidity by
the PHENIX detector at RHIC. Precision resonance centroid and width values are
extracted as a function of collision centrality. No significant variation from
the PDG accepted values is observed. The transverse mass spectra are fitted
with a linear exponential function for which the derived inverse slope
parameter is seen to be constant as a function of centrality. These data are
also fitted by a hydrodynamic model with the result that the freeze-out
temperature and the expansion velocity values are consistent with the values
previously derived from fitting single hadron inclusive data. As a function of
transverse momentum the collisions scaled peripheral.to.central yield ratio RCP
for the is comparable to that of pions rather than that of protons. This result
lends support to theoretical models which distinguish between baryons and
mesons instead of particle mass for explaining the anomalous proton yield.Comment: 326 authors, 24 pages text, 23 figures, 6 tables, RevTeX 4. To be
submitted to Physical Review C as a regular article. Plain text data tables
for the points plotted in figures for this and previous PHENIX publications
are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm
Evidence for the h_b(1P) meson in the decay Upsilon(3S) --> pi0 h_b(1P)
Using a sample of 122 million Upsilon(3S) events recorded with the BaBar
detector at the PEP-II asymmetric-energy e+e- collider at SLAC, we search for
the spin-singlet partner of the P-wave chi_{bJ}(1P) states in the
sequential decay Upsilon(3S) --> pi0 h_b(1P), h_b(1P) --> gamma eta_b(1S). We
observe an excess of events above background in the distribution of the recoil
mass against the pi0 at mass 9902 +/- 4(stat.) +/- 2(syst.) MeV/c^2. The width
of the observed signal is consistent with experimental resolution, and its
significance is 3.1sigma, including systematic uncertainties. We obtain the
value (4.3 +/- 1.1(stat.) +/- 0.9(syst.)) x 10^{-4} for the product branching
fraction BF(Upsilon(3S)-->pi0 h_b) x BF(h_b-->gamma eta_b).Comment: 8 pages, 4 postscript figures, submitted to Phys. Rev. D (Rapid
Communications
Measurement of the branching fraction and CP content for the decay B(0) -> D(*+)D(*-)
This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APS.We report a measurement of the branching fraction of the decay B0âD*+D*- and of the CP-odd component of its final state using the BABAR detector. With data corresponding to an integrated luminosity of 20.4ââfb-1 collected at the ΄(4S) resonance during 1999â2000, we have reconstructed 38 candidate signal events in the mode B0âD*+D*- with an estimated background of 6.2±0.5 events. From these events, we determine the branching fraction to be B(B0âD*+D*-)=[8.3±1.6(stat)±1.2(syst)]Ă10-4. The measured CP-odd fraction of the final state is 0.22±0.18(stat)±0.03(syst).This work is supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the A.P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation
Planck 2013 results. XXII. Constraints on inflation
We analyse the implications of the Planck data for cosmic inflation. The Planck nominal mission temperature anisotropy measurements, combined with the WMAP large-angle polarization, constrain the scalar spectral index to be ns = 0:9603 _ 0:0073, ruling out exact scale invariance at over 5_: Planck establishes an upper bound on the tensor-to-scalar ratio of r < 0:11 (95% CL). The Planck data thus shrink the space of allowed standard inflationary models, preferring potentials with V00 < 0. Exponential potential models, the simplest hybrid inflationary models, and monomial potential models of degree n _ 2 do not provide a good fit to the data. Planck does not find statistically significant running of the scalar spectral index, obtaining dns=dln k = 0:0134 _ 0:0090. We verify these conclusions through a numerical analysis, which makes no slowroll approximation, and carry out a Bayesian parameter estimation and model-selection analysis for a number of inflationary models including monomial, natural, and hilltop potentials. For each model, we present the Planck constraints on the parameters of the potential and explore several possibilities for the post-inflationary entropy generation epoch, thus obtaining nontrivial data-driven constraints. We also present a direct reconstruction of the observable range of the inflaton potential. Unless a quartic term is allowed in the potential, we find results consistent with second-order slow-roll predictions. We also investigate whether the primordial power spectrum contains any features. We find that models with a parameterized oscillatory feature improve the fit by __2 e_ _ 10; however, Bayesian evidence does not prefer these models. We constrain several single-field inflation models with generalized Lagrangians by combining power spectrum data with Planck bounds on fNL. Planck constrains with unprecedented accuracy the amplitude and possible correlation (with the adiabatic mode) of non-decaying isocurvature fluctuations. The fractional primordial contributions of cold dark matter (CDM) isocurvature modes of the types expected in the curvaton and axion scenarios have upper bounds of 0.25% and 3.9% (95% CL), respectively. In models with arbitrarily correlated CDM or neutrino isocurvature modes, an anticorrelated isocurvature component can improve the _2 e_ by approximately 4 as a result of slightly lowering the theoretical prediction for the ` <_ 40 multipoles relative to the higher multipoles. Nonetheless, the data are consistent with adiabatic initial conditions
Measurement of D-s(+) and D-s(*+) production in B meson decays and from continuum e(+)e(-) annihilation at âs=10.6 GeV
This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APSNew measurements of Ds+ and Ds*+ meson production rates from B decays and from qqÌ
continuum events near the ΄(4S) resonance are presented. Using 20.8 fb-1 of data on the ΄(4S) resonance and 2.6 fb-1 off-resonance, we find the inclusive branching fractions B(BâDs+X)=(10.93±0.19±0.58±2.73)% and B(BâDs*+X)=(7.9±0.8±0.7±2.0)%, where the first error is statistical, the second is systematic, and the third is due to the Ds+âÏÏ+ branching fraction uncertainty. The production cross sections Ï(e+e-âDs+X)ĂB(Ds+âÏÏ+)=7.55±0.20±0.34pb and Ï(e+e-âDs*±X)ĂB(Ds+âÏÏ+)=5.8±0.7±0.5pb are measured at center-of-mass energies about 40 MeV below the ΄(4S) mass. The branching fractions ÎŁB(BâDs(*)+D(*))=(5.07±0.14±0.30±1.27)% and ÎŁB(BâDs*+D(*))=(4.1±0.2±0.4±1.0)% are determined from the Ds(*)+ momentum spectra. The mass difference m(Ds+)-m(D+)=98.4±0.1±0.3MeV/c2 is also measured.This work was supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the Swiss NSF, A. P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation
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