271 research outputs found
Surface criticality and multifractality at localization transitions
We develop the concept of surface multifractality for
localization-delocalization (LD) transitions in disordered electronic systems.
We point out that the critical behavior of various observables related to wave
functions near a boundary at a LD transition is different from that in the
bulk. We illustrate this point with a calculation of boundary critical and
multifractal behavior at the 2D spin quantum Hall transition and in a 2D metal
at scales below the localization length.Comment: Published versio
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Advancing assessment methods for data-limited fish stocks
The assessment of data-limited fish stocks is crucial for the sustainable management of marine living resources. Dependent on the scope and type of available data, a range of assessment methods are available, such as catch-only, length-based, or catch and survey-based methods. However, these methods suffer from several shortcomings, such as assuming equilibrium, over-simplifying biological processes and ecological interactions, and lacking quantification of assessment uncertainty. Here, we present several advancements of data-limited stock assessment methods tackling some of these limitations. The s6model and rejuvenated traditional length-based assessment methods allow deriving biological reference levels from one year of length-frequency data while quantifying the assessment uncertainty. The stochastic production model in continuous time (SPiCT) requiring only catch and CPUE time series quantifies differences between seasonal patterns in the fishing mortality and oscillating productivity. The stage-based biomass dynamic model building upon SPiCT resolves biomass dynamics between the juvenile and adult stages, which improves the predictability of future biomass levels. The incorporation of stochastic data-limited methods into management strategy evaluation frameworks reveal appropriate harvest control rules for different stocks and how to account for the assessment uncertainty. The implementation and further development of such methods will contribute to a biological sustainable management of marine living resources, and provide robust platforms for additional quantitative economic analyses of the fisheries exploiting the resources
N-3 PUFAs induce inflammatory tolerance by formation of KEAP1-containing SQSTM1/p62-bodies and activation of NFE2L2
Inflammation is crucial in the defense against infections but must be tightly controlled to limit detrimental hyperactivation. Our diet influences inflammatory processes and omega-3 polyunsaturated fatty acids (n-3 PUFAs) have known anti-inflammatory effects. The balance of pro- and anti-inflammatory processes is coordinated by macrophages and macroautophagy/autophagy has recently emerged as a cellular process that dampens inflammation. Here we report that the n-3 PUFA docosahexaenoic acid (DHA) transiently induces cytosolic speckles of the autophagic receptor SQSTM1/p62 (sequestosome 1) (described as SQSTM1/p62-bodies) in macrophages. We suggest that the formation of SQSTM1/p62-bodies represents a fast mechanism of NFE2L2/Nrf2 (nuclear factor, erythroid 2 like 2) activation by recruitment of KEAP1 (kelch like ECH associated protein 1). Further, the autophagy receptor TAX1BP1 (Tax1 binding protein 1) and ubiquitin-editing enzyme TNFAIP3/A20 (TNF α induced protein 3) could be identified in DHA-induced SQSTM1/p62-bodies. Simultaneously, DHA strongly dampened the induction of pro-inflammatory genes including CXCL10 (C-X-C motif chemokine ligand 10) and we suggest that formation of SQSTM1/p62-bodies and activation of NFE2L2 leads to tolerance towards selective inflammatory stimuli. Finally, reduced CXCL10 levels were related to the improved clinical outcome in n-3 PUFA-supplemented heart-transplant patients and we propose CXCL10 as a robust marker for the clinical benefits mobilized by n-3 PUFA supplementation
Wave function statistics and multifractality at the spin quantum Hall transition
The statistical properties of wave functions at the critical point of the
spin quantum Hall transition are studied. The main emphasis is put onto
determination of the spectrum of multifractal exponents governing
the scaling of moments with the system
size and the spatial decay of wave function correlations. Two- and
three-point correlation functions are calculated analytically by means of
mapping onto the classical percolation, yielding the values and
. The multifractality spectrum obtained from numerical
simulations is given with a good accuracy by the parabolic approximation
but shows detectable deviations. We also study
statistics of the two-point conductance , in particular, the spectrum of
exponents characterizing the scaling of the moments . Relations
between the spectra of critical exponents of wave functions (),
conductances (), and Green functions at the localization transition with a
critical density of states are discussed.Comment: 16 pages, submitted to J. Phys. A, Special Issue on Random Matrix
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Further Evidence for the Decay K+ to pi+ neutrino-antineutrino
Additional evidence for the rare kaon decay K+ to pi+ neutrino-antineutrino
has been found in a new data set with comparable sensitivity to the previously
reported result. One new event was observed in the pion momentum region
examined, 211<P<229 MeV/c, bringing the total for the combined data set to two.
Including all data taken, the backgrounds were estimated to contribute 0.15 pm
0.05 events. The branching ratio is B=1.57^{+1.75}_{-0.82} 10^{-10}.Comment: 10 pages, 2 figure
Aerosol optical properties in the North China Plain during HaChi campaign: an in-situ optical closure study
The largest uncertainty in the estimation of climate forcing stems from atmospheric aerosols. In early spring and summer of 2009, two periods of in-situ measurements on aerosol physical and chemical properties were conducted within the HaChi (Haze in China) project at Wuqing, a town between Beijing and Tianjin in the North China Plain (NCP). Aerosol optical properties, including the scattering coefficient (&sigma;<sub>sp</sub>), the hemispheric back scattering coefficient (&sigma;<sub>bsp</sub>), the absorption coefficient (&sigma;<sub>ap</sub>), as well as the single scattering albedo (ω), are presented. The diurnal and seasonal variations are analyzed together with meteorology and satellite data. The mean values of &sigma;<sub>sp, 550 nm</sub> of the dry aerosol in spring and summer are 280&plusmn;253 and 379&plusmn;251 Mm<sup>−1</sup>, respectively. The average &sigma;<sub>ap</sub> for the two periods is respectively 47&plusmn;38 and 43&plusmn;27 Mm<sup>−1</sup>. The mean values of &omega; at the wavelength of 637 nm are 0.82&plusmn;0.05 and 0.86&plusmn;0.05 for spring and summer, respectively. The relative high levels of &sigma;<sub>sp</sub> and &sigma;<sub>bsp</sub> are representative of the regional aerosol pollution in the NCP. Pronounced diurnal cycle of $&sigma;<sub>sp</sub>, &sigma;<sub>ap</sub> and ω are found, mainly influenced by the evolution of boundary layer and the accumulation of local emissions during nighttime. The pollutants transported from the southwest of the NCP are more significant than that from the two megacities, Beijing and Tianjin, in both spring and summer. An optical closure experiment is conducted to better understand the uncertainties of the measurements. Good correlations (<i>R</i>>0.98) are found between the values measured by the nephelometer and the values calculated with a modified Mie model. The Monte Carlo simulation shows an uncertainty of about 30 % for the calculations. Considering all possible uncertainties of measurements, calculated &sigma;<sub>sp</sub> and &sigma;<sub>bsp</sub> agree well with the measured values, indicating a stable performance of instruments and thus reliable aerosol optical data
Measurement of Direct Photon Emission in K^+ -> pi^+ pi^0 gamma Decay
We have performed a measurement of the K^+ -> pi^+ pi^0 gamma decay and have
observed 2 X 10^4 events. The best fit to the decay spectrum gives a branching
ratio for direct photon emission of (4.7\pm0.8\pm0.3) X 10^{-6} in the pi^+
kinetic energy region of 55 to 90 MeV and requires no component due to
interference with inner bremsstrahlung.Comment: 9 pages, 3 figures. To be submitted to PR
Improved Measurement of the K+ to pi+ nu nubar Branching Ratio
An additional event near the upper kinematic limit for K+ to pi+ nu nubar has
been observed by Experiment E949 at Brookhaven National Laboratory. Combining
previously reported and new data, the branching ratio is B(K+ to pi+ nu nubar)=
1.47 (+1.30, - 0.89) x 10-10 based on three events observed in the pion
momentum region 211<P<229 MeV/c. At the measured central value of the branching
ratio, the additional event had a signal-to-background ratio of 0.9
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