The local Callan-Symanzik equation: structure and applications

The local Callan-Symanzik equation describes the response of a quantum field theory to local scale transformations in the presence of background sources. The consistency conditions associated with this anomalous equation imply non-trivial relations among the $\beta$-function, the anomalous dimensions of composite operators and the short distance singularities of correlators. In this paper we discuss various aspects of the local Callan-Symanzik equation and present new results regarding the structure of its anomaly. We then use the equation to systematically write the n-point correlators involving the trace of the energy-momentum tensor. We use the latter result to give a fully detailed proof that the UV and IR asymptotics in a neighbourhood of a 4D CFT must also correspond to CFTs. We also clarify the relation between the matrix entering the gradient flow formula for the $\beta$-function and a manifestly positive metric in coupling space associated with matrix elements of the trace of the energy momentum tensor.Comment: v2: Modified discussion of the amplitude; v3: typos fixe

A naturally light dilaton

Goldstone's theorem does not apply straightforwardly to the case of spontaneously broken scale invariance. We elucidate under what conditions a light scalar degree of freedom, identifiable with the dilaton, can naturally arise. Our construction can be considered an explicit dynamical solution to the cosmological constant problem in the scalar version of gravity.Comment: v2: published versio

Measuring the spin of black holes in binary systems using gravitational waves

Compact binary coalescences are the most promising sources of gravitational waves (GWs) for ground based detectors. Binary systems containing one or two spinning black holes are particularly interesting due to spin-orbit (and eventual spin-spin) interactions, and the opportunity of measuring spins directly through GW observations. In this letter we analyze simulated signals emitted by spinning binaries with several values of masses, spins, orientation, and signal-to-noise ratio. We find that spin magnitudes and tilt angles can be estimated to accuracy of a few percent for neutron star--black hole systems and $\sim$ 5-30% for black hole binaries. In contrast, the difference in the azimuth angles of the spins, which may be used to check if spins are locked into resonant configurations, cannot be constrained. We observe that the best performances are obtained when the line of sight is perpendicular to the system's total angular momentum, and that a sudden change of behavior occurs when a system is observed from angles such that the plane of the orbit can be seen both from above and below during the time the signal is in band. This study suggests that the measurement of black hole spin by means of GWs can be as precise as what can be obtained from X-ray binaries.Comment: 4 figures, Version accepted for publication on PR

Parameter estimation for heavy binary-black holes with networks of second-generation gravitational-wave detectors

The era of gravitational-wave astronomy has started with the discovery of the binary black hole coalescences (BBH) GW150914 and GW151226 by the LIGO instruments. These systems allowed for the first direct measurement of masses and spins of black holes. The component masses in each of the systems have been estimated with uncertainties of over 10\%, with only weak constraints on the spin magnitude and orientation. In this paper we show how these uncertainties will be typical for this type of source when using advanced detectors. Focusing in particular on heavy BBH of masses similar to GW150914, we find that typical uncertainties in the estimation of the source-frame component masses will be around 40\%. We also find that for most events the magnitude of the component spins will be estimated poorly: for only 10\% of the systems the uncertainties in the spin magnitude of the primary (secondary) BH will be below 0.7 (0.8). Conversely, the effective spin along the angular momentum can be estimated more precisely than either spins, with uncertainties below 0.16 for 10\% of the systems. We also quantify how often large or negligible primary spins can be excluded, and how often the sign of the effective spin can be measured. We show how the angle between the spin and the orbital angular momentum can only seldom be measured with uncertainties below 60$^\circ$. We then investigate how the measurement of spin parameters depends on the inclination angle and the total mass of the source. We find that when precession is present, uncertainties are smaller for systems observed close to edge-on. Contrarily to what happens for low-mass, inspiral dominated, sources, for heavy BBH we find that large spins aligned with the orbital angular momentum can be measured with small uncertainty. We also show how spin uncertainties increase with the total mass. Finally...Comment: 18 pages, 28 figures. The abstract is cut in the Arxiv metadata. Refer to PDF. Version accepted by PR

Resistance traits and AFLP characterization of diploid primitive tuber-bearing potatoes.

ISSN: 0925-986

SP728INFLUENCE OF TNF-ALPHA GENE POLYMORPHISM ON THE COURSE OFNEPHROTIC SYNDROME

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Structure of Starch-Sepiolite Bio-Nanocomposites: Effect of Processing and Matrix-Filler Interactions

Sepiolite clay is a natural filler particularly suitable to be used with polysaccharide matrices (e.g., in starch-based bio-nanocomposites), increasing their attractiveness for a wide range of applications, such as packaging. Herein, the effect of the processing (i.e., starch gelatinization, addition of glycerol as plasticizer, casting to obtain films) and of the sepiolite filler amount on the microstructure of starch-based nanocomposites was investigated by SS-NMR (solid-state nuclear magnetic resonance), XRD (X-ray diffraction) and FTIR (Fourier-transform infrared) spectroscopy. Morphology, transparency and thermal stability were then assessed by SEM (scanning electron microscope), TGA (thermogravimetric analysis) and UV-visible spectroscopy. It was demonstrated that the processing method allowed to disrupt the rigid lattice structure of semicrystalline starch and thus obtain amorphous flexible films, with high transparency and good thermal resistance. Moreover, the microstructure of the bio-nanocomposites was found to intrinsically depend on complex interactions among sepiolite, glycerol and starch chains, which are also supposed to affect the final properties of the starch-sepiolite composite materials

Clinical characteristics and outcome of ceftazidime/avibactam-resistant Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae infections. A retrospective, observational, 2-center clinical study

Background Recently, Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae (KPC-Kp) with resistance to ceftazidime/avibactam (CZA-R) has been described, including KPC variants that restore carbapenem susceptibility. The aim of the study was to analyze the clinical characteristics and outcomes of infections caused by CZA-R KPC-Kp. Methods From 2019 to 2021, a retrospective 2-center study including patients with infections due to CZA-R KPC-Kp hospitalized at 2 academic hospitals in Rome was conducted. Demographic and clinical characteristics were collected. Principal outcome was 30-day all-cause mortality. Statistical analyses were performed with Stata-IC17 software. Results Overall, 59 patients were included (mean age, 64.4 & PLUSMN; 14.6 years; mean Charlson comorbidity index score, 4.5 & PLUSMN; 2.7). Thirty-four patients (57.6%) had infections caused by CZA-R and meropenem (MEM)-susceptible strains. A previous CZA therapy was observed in 40 patients (67.8%), mostly in patients with MEM-susceptible KPC variant (79.4% vs 52%, P = .026). Primary bacteremia was observed in 28.8%, followed by urinary tract infections and pneumonia. At infection onset, septic shock was present in 15 subjects (25.4%). After adjustment for confounders, only the presence of septic shock was independently associated with mortality (P = .006). Conclusions Infections due to CZA-R KPC-Kp often occur in patients who had previously received CZA, especially in the presence of strains susceptible to MEM. Nevertheless, one-third of patients had never received CZA before KPC-Kp CZA-R. Since the major driver for mortality was infection severity, understanding the optimal therapy in patients with KPC-Kp CZA-R infections is of crucial importance.Clinical characteristics and outcomes of infections caused by ceftazidime/avibactam-resistant (CZA-R) Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae were analyzed. Ceftazidime/avibactam-resistant and meropenem-susceptible KPC variants accounted for more than half of patients. Infections due to CZA-R KPC-Kp often occur in patients who had previously received CZA, especially in the presence of strains susceptible to meropenem. Nevertheless, one-third of patients had never received CZA before isolation of CZA strains. Infection severity was the only independent predictor of 30-day mortality