We investigate the impact of hydrodynamic fluctuations on correlation functions in a scale invariant fluid with a conserved U(1) charge. The kinetic equations for the two-point functions of pressure, ...momentum, and heat energy densities are derived within the framework of stochastic hydrodynamics. The leading nonanalytic contributions to the energy-momentum tensor as well as the U(1) current are determined from the solutions to these kinetic equations. In the case of a static homogeneous background we show that the long time tails obtained from hydrokinetic equations reproduce the one-loop results derived from statistical field theory. We use these results to establish bounds on transport coefficients. We generalize the stochastic equation to a background flow undergoing Bjorken expansion. We compute the leading fractional power O((τT)–3/2) correction to the U(1) current and compare with the first-order gradient term.
We study the behavior of the bulk viscosity ζ in QCD near a possible critical end point. We verify the expectation that (ζ/s) ~ a(ξ/ξ0)xζ, where s is the entropy density, ξ is the correlation length, ...ξ0 is the noncritical correlation length, a is a constant, and xζ ≃ 3. Using a recently developed equation of state that includes a critical point in the universality class of the Ising model we estimate the constant of proportionality a. We find that a is typically quite small, a ~ O(10−4). We observe, however, that this result is sensitive to the commonly made assumption that the Ising temperature axis is approximately aligned with the QCD chemical potential axis. If this is not the case, then the critical ζ/s can approach the noncritical value of η/s, where η is the shear viscosity, even if the enhancement of the correlation length is modest, ξ/ξ0 ~ 2.
We investigate the nonlinear transport processes and hydrodynamization of a system of gluons undergoing longitudinal boost-invariant expansion. The dynamics is described within the framework of the ...Boltzmann equation in the small-angle approximation. The kinetic equations for a suitable set of moments of the one-particle distribution function are derived. By investigating the stability and asymptotic resurgent properties of this dynamical system, we demonstrate, that its solutions exhibit a rather different behavior for large (UV) and small (IR) effective Knudsen numbers. Close to the forward attractor in the IR regime the constitutive relations of each moment can be written as a multiparameter transseries. This resummation scheme allows us to extend the definition of a transport coefficient to the nonequilibrium regime naturally. Each transport coefficient is renormalized by the nonperturbative contributions of the nonhydrodynamic modes. The Knudsen number dependence of the transport coefficient is governed by the corresponding renormalization group flow equation. An interesting feature of the Yang-Mills plasma in this regime is that it exhibits transient non-Newtonian behavior while hydrodynamizing. In the UV regime the solution for the moments can be written as a power-law asymptotic series with a finite radius of convergence. We show that radius of convergence of the UV perturbative expansion grows linearly as a function of the shear viscosity to entropy density ratio. Finally, we compare the universal properties in the pullback and forward attracting regions to other kinetic models including the relaxation time approximation and the effective kinetic Arnold-Moore-Yaffe theory.
We demonstrate how to identify which physical processes dominate the low-energy spectral functions of correlated electron systems. We obtain an unambiguous classification through an analysis of the ...equation of motion for the electron self-energy in its charge, spin, and particle-particle representations. Our procedure is then employed to clarify the controversial physics responsible for the appearance of the pseudogap in correlated systems. We illustrate our method by examining the attractive and repulsive Hubbard model in two dimensions. In the latter, spin fluctuations are identified as the origin of the pseudogap, and we also explain why d-wave pairing fluctuations play a marginal role in suppressing the low-energy spectral weight, independent of their actual strength.
Starting from the (Hubbard) model of an atom, we demonstrate that the uniqueness of the mapping from the interacting to the noninteracting Green function, G→G_{0}, is strongly violated, by providing ...numerous explicit examples of different G_{0} leading to the same physical G. We argue that there are indeed infinitely many such G_{0}, with numerous crossings with the physical solution. We show that this rich functional structure is directly related to the divergence of certain classes of (irreducible vertex) diagrams, with important consequences for traditional many-body physics based on diagrammatic expansions. Physically, we ascribe the onset of these highly nonperturbative manifestations to the progressive suppression of the charge susceptibility induced by the formation of local magnetic moments and/or resonating valence bond (RVB) states in strongly correlated electron systems.
We identify the precise hallmarks of the local magnetic moment formation and its Kondo screening in the frequency structure of the generalized charge susceptibility. The sharpness of our ...identification even pinpoints an alternative criterion to determine the Kondo temperature of strongly correlated systems on the two-particle level, which only requires calculations at the lowest Matsubara frequency. We showcase its strength by applying it to the single impurity and the periodic Anderson model as well as to the Hubbard model. Our results represent a significant progress for the general understanding of quantum field theory at the two-particle level and allow for tracing the limits of the physics captured by perturbative approaches for correlated systems.
This guideline was developed as a joint interdisciplinary European project, including physicians from all relevant disciplines as well as patients. It is a consensus‐based guideline, taking available ...evidence from other guidelines, systematic reviews and published studies into account. This first part of the guideline covers methods, patient perspective, general measures and avoidance strategies, basic emollient treatment and bathing, dietary intervention, topical anti‐inflammatory therapy, phototherapy and antipruritic therapy, whereas the second part covers antimicrobial therapy, systemic treatment, allergen‐specific immunotherapy, complementary medicine, psychosomatic counselling and educational interventions. Management of AE must consider the individual clinical variability of the disease; highly standardized treatment rules are not recommended. Basic therapy is focused on treatment of disturbed barrier function by hydrating and lubricating topical treatment, besides further avoidance of specific and unspecific provocation factors. Topical anti‐inflammatory treatment based on glucocorticosteroids and calcineurin inhibitors is used for flare management and for proactive therapy for long‐term control. Topical corticosteroids remain the mainstay of therapy, whereas tacrolimus and pimecrolimus are preferred in sensitive skin areas and for long‐term use. Topical phosphodiesterase inhibitors may be a treatment alternative when available. Adjuvant therapy includes UV irradiation, preferably with UVB 311 nm or UVA1. Pruritus is targeted with the majority of the recommended therapies, but some patients may need additional antipruritic therapy. Antimicrobial therapy, systemic anti‐inflammatory treatment, immunotherapy, complementary medicine and educational intervention will be addressed in part II of the guideline.
Determinations of the shear viscosity of trapped ultracold gases suffer from systematic, uncontrolled uncertainties related to the treatment of the dilute part of the gas cloud. In this work we ...present an analysis of expansion experiments based on a new method, anisotropic fluid dynamics, that interpolates between Navier-Stokes fluid dynamics at the center of the cloud and ballistic behavior in the dilute corona. We validate the method using a comparison between anisotropic fluid dynamics and numerical solutions of the Boltzmann equation. We then apply anisotropic fluid dynamics to the expansion data reported by Cao et al. In the high-temperature limit we find η=0.282(mT)^{3/2}, which agrees within about 5% with the theoretical prediction η=0.269(mT)^{3/2}.
This guideline was developed as a joint interdisciplinary European project, including physicians from all relevant disciplines as well as patients. It is a consensus‐based guideline, taking available ...evidence from other guidelines, systematic reviews and published studies into account. This second part of the guideline covers antimicrobial therapy, systemic treatment, allergen‐specific immunotherapy, complementary medicine, psychosomatic counselling and educational interventions, whereas the first part covers methods, patient perspective, general measures and avoidance strategies, basic emollient treatment and bathing, dietary intervention, topical anti‐inflammatory therapy, phototherapy and antipruritic therapy. Management of AE must consider the individual clinical variability of the disease. Systemic immunosuppressive treatment with cyclosporine, methotrexate, azathioprine and mycophenolic acid is established option for severe refractory cases, and widely available. Biologicals targeting the T helper 2 pathway such as dupilumab may be a safe and effective, disease‐modifying alternative when available. Oral drugs such as JAK inhibitors and histamine 4 receptor antagonists are in development. Microbial colonization and superinfection may cause disease exacerbation and can require additional antimicrobial treatment. Allergen‐specific immunotherapy with aeroallergens may be considered in selected cases. Psychosomatic counselling is recommended especially in stress‐induced exacerbations. Therapeutic patient education (‘Eczema school’) is recommended for children and adult patients. General measures, basic emollient treatment, bathing, dietary intervention, topical anti‐inflammatory therapy, phototherapy and antipruritic therapy have been addressed in the first part of the guideline.
Sepsis is now operationally defined as life-threatening organ dysfunction caused by an infection, identified by an acute change in SOFA-Score of at least two points, including clinical chemistry such ...as creatinine or bilirubin concentrations. However, little knowledge exists about organ-specific microRNAs as potentially new biomarkers. Accordingly, we tested the hypotheses that micro-RNA-122, the foremost liver-related micro-RNA (miR), 1) discriminates between sepsis and infection, 2) is an early predictor for mortality, and 3) improves the prognostic value of the SOFA-score.
We analyzed 108 patients with sepsis (infection + increase SOFA-Score ≥2) within the first 24h of ICU admission and as controls 20 patients with infections without sepsis (infection + SOFA-Score ≤1). Total circulating miR was isolated from serum and relative miR-122 expression was measured (using spiked-in cel-miR-54) and associated with 30-day survival.
30-day survival of the sepsis patients was 63%. miR-122 expression was 40-fold higher in non-survivors (p = 0.001) and increased almost 6-fold in survivors (p = 0.013) compared to controls. miR-122 serum-expression discriminated both between sepsis vs. infection (AUC 0.760, sensitivity 58.3%, specificity 95%) and survivors vs. non-survivors (AUC 0.728, sensitivity 42.5%, specificity 94%). Multivariate Cox-regression analysis revealed miR-122 (HR 4.3; 95%-CI 2.0-8.9, p<0.001) as independent prognostic factor for 30-day mortality. Furthermore, the predictive value for 30-day mortality of the SOFA-Score (AUC 0.668) was improved by adding miR-122 (AUC 0.743; net reclassification improvement 0.37, p<0.001; integrated discrimination improvement 0.07, p = 0.007).
Increased miR-122 serum concentration supports the discrimination between infection and sepsis, is an early and independent risk factor for 30-day mortality, and improves the prognostic value of the SOFA-Score, suggesting a potential role for miR-122 in sepsis-related prediction models.
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