On the origin of intrinsic alignment in cosmic shear measurements: an analytic argument

Galaxy intrinsic alignment can be a severe source of error in weak-lensing studies. The problem has been widely studied by numerical simulations and with heuristic models, but without a clear theoretical justification of its origin and amplitude. In particular, it is still unclear whether intrinsic alignment of galaxies is dominated by formation and accretion processes or by the effects of the instantaneous tidal field acting upon them. We investigate this question by developing a simple model of intrinsic alignment for elliptical galaxies, based on the instantaneous tidal field. Making use of the galaxy stellar distribution function, we estimate the intrinsic alignment signal and find that although it has the expected dependence on the tidal field, it is too weak to account for the observed signal. This is an indirect validation of the standard view that intrinsic alignment is caused by formation and/or accretion processes.Comment: 11 pages, 4 figures, accepted for publication on Astronomy & Astrophysic

People, their Experiences and Merchant Practices in a Port-city: Naples as a Mediterranean Crossroads in the Modern Age

No abstrac

People, their Experiences and Merchant Practices in a Port-city: Naples as a Mediterranean Crossroads in the Modern Age

No abstrac

Dark soliton collisions in superfluid Fermi gases

In this work dark soliton collisions in a one-dimensional superfluid Fermi gas are studied across the BEC-BCS crossover by means of a recently developed finite-temperature effective field theory [S. N. Klimin, J. Tempere, G. Lombardi, J. T. Devreese, Eur. Phys. J. B 88, 122 (2015)] . The evolution of two counter-propagating solitons is simulated numerically based on the theory's nonlinear equation of motion for the pair field. The resulting collisions are observed to introduce a spatial shift into the trajectories of the solitons. The magnitude of this shift is calculated and studied in different conditions of temperature and spin-imbalance. When moving away from the BEC-regime, the collisions are found to become inelastic, emitting the lost energy in the form of small-amplitude density oscillations. This inelasticity is quantified and its behavior analyzed and compared to the results of other works. The dispersion relation of the density oscillations is calculated and is demonstrated to show a good agreement with the spectrum of collective excitations of the superfluid

Polarization of a quasi two-dimensional repulsive Fermi gas with Rashba spin-orbit coupling: a variational study

Motivated by the remarkable experimental control of synthetic gauge fields in ultracold atomic systems, we investigate the effect of an artificial Rashba spin-orbit coupling on the spin polarization of a two-dimensional repulsive Fermi gas. By using a variational many-body wavefunction, based on a suitable spinorial structure, we find that the polarization properties of the system are indeed controlled by the interplay between spin-orbit coupling and repulsive interaction. In particular, two main effects are found: 1) The Rashba coupling determines a gradual increase of the degree of polarization beyond the critical repulsive interaction strength, at variance with conventional 2D Stoner instability. 2) The critical interaction strength, above which finite polarization is developed, shows a dependence on the Rashba coupling, i.e. it is enhanced in case the Rashba coupling exceeds a critical value. A simple analytic expression for the critical interaction strength is further derived in the context of our variational formulation, which allows for a straightforward and insightful analysis of the present problem.Comment: 7 pages, 3 figure

Complete NLO corrections to off-shell tt‾Z\text{t}\overline{\text{t}}\text{Z} production at the LHC

Measuring precisely top-pair-associated processes at hadron colliders will become possible with the upcoming LHC running stages. The increased data statistics will especially enable differential measurements leading to an improved characterisation of such processes. Aiming at a consistent data-theory comparison, precise Standard-Model predictions are needed, including higher-order corrections and full off-shell effects. In this work we present NLO-accurate predictions for the production and decay of a top-antitop pair in association with a Z boson at the LHC, in the multi-lepton decay channel. The complete set of LO contributions and NLO corrections of EW and QCD origin is included. The calculation is based on full matrix elements, computed with all resonant and non-resonant contributions, complete spin correlations and interference effects. Integrated and differential cross-sections are presented for a realistic fiducial setup.Comment: 38 pages, 10 pdf figure files, 24 png figure file

Effects of winter swimming on haematological parameters

Introduction: Winter swimming represents an intensive short-term exposure to cold, and thus it is considered a strong physical stress. Cold-based treatments, i.e. immersions in cold water, are spreading in sport medicine for improving recovery following muscle traumas, although a universal acceptance of that method is not still achieved. Materials and methods: Fifteen healthy subjects (13 males and 2 females) were recruited among the participants to a 150 meters long swimming race in cold water (6 °C). Blood samples were collec-ted the day before and immediately after the race and a panel of haematological parameters was eva-luated. Results: Swimming in cold water induced a significant variation in the blood cell fraction composition compared to the rest condition, as measured the day before the competition. Red blood cells, white blood cells and platelets count increased significantly (4.7%, P = 0.005; 40.6%, P < 0.001 and 25.0%, P < 0.001, respectively). While the relative number of leukocytes did not change significantly, apart from a strong decrease of the eosinophils population (-48.6%; P < 0.001), a strong increase in the total number of neutrophil granulocytes, lymphocytes and monocytes was recorded (42.6%, P = 0.002, 58.2%, P = 0.001 and 27.5%, P = 0.021, respectively). Following normalization on plasma vo-lume change (-2.54%) the results were unchanged, demonstrating that the variations were not due to a mere haemoconcentration. Conclusions: When represented by brief exposure to cold water, winter swimming induces strong non-pathological modifications of haematological homeostasis

Letter by Aquaro et al Regarding Article, "Intermediate-Signal-Intensity Late Gadolinium Enhancement Predicts Ventricular Tachyarrhythmias in Patients With Hypertrophic Cardiomyopathy"

n/

The WEB-based Asthma Control: An intriguing connection or a dangerous hazard?

Globally, an estimated 300 million people have asthma, presenting a considerable and increasing burden of disease for healthcare systems, families, and patients themselves. Despite two decades of guidelines, asthma seems to remain not optimally controlled in a substantial proportion of people. The achievement of asthma control is the result of the interaction among different variables concerning the disease pattern and patients' and physicians' knowledge and behavior. It is well known that adherence to treatment increases in parallel to patient education. There is now a growing interest in the use of digital information technologies to promote asthma control and improve outcomes. Mobile health, or mHealth, refers to mobile devices, medical sensors, and communication technologies that can enhance chronic disease care and monitoring. Aim of this review was to evaluate the web resources nowadays available and to analyze the published studies about the web-based instruments used to improve asthma knowledge, control asthma outcomes. In general, studies revealed that the technology is well accepted. Interactive asthma technology may be, in addition, of help in reaching populations difficult to reach, such as inner city populations. The number of tools and apps available continues to increase, and agencies such as the FDA, become involved in their regulation, thus the mHealth landscape will continue to evolve. Although asthma tools and apps have great potential to improve care for asthma, the proof of data reproducibility, the demonstration of effectiveness, and the privacy issues still represent the major technical problems

Serum Potassium Disorders Predict Subsequent Kidney Injury: A Retrospective Observational Cohort Study of Hospitalized Patients

Introduction: Electrolyte disorders are common findings in kidney diseases and might represent a useful biomarker preceding kidney injury. Serum potassium [K+] imbalance is still poorly investigated for association with acute kidney injury (AKI), and most evidence came from intensive care units. The aim of our study was to comprehensively investigate this association in a large, unselected cohort of hospitalized patients. Methods: We performed a retrospective observational cohort study on the inpatient population admitted to Fondazione Policlinico Universitario A. Gemelli IRCCS between January 1, 2010 and December 31, 2014, with inclusion of adult patients with at least 2 [K+] and 3 serum creatinine measurements who did not develop AKI during an initial 10-day window. The outcome of interest was in-hospital AKI. The exposures of interest were [K+] fluctuations and hypo (HoK) and hyperkalemia (HerK). [K+] variability was evaluated using the coefficient of variation. Cox proportional hazards regression models were used to obtain hazard ratios and 95% confidence intervals of the association between the exposures of interest and development of AKI. Results: About 21,830 hospital admissions from 18,836 patients were included in our study. During a median follow-up of 5 (interquartile range [IQR] 7) days, AKI was observed in 555 hospital admissions (2.9%); median time for AKI development was 5 (IQR 7) days. Higher [K+] variability was independently associated with increased risk of AKI with a statistically significant linear trend across groups (p value = 0.012). A significantly higher incidence of AKI was documented in patients with HerK compared with normokalemia. No statistically significant difference was observed between HoK and HerK (p value = 0.92). Conclusion: [K+] abnormalities including fluctuations even within the normal range are associated with development of AKI