University of Zagreb

About: University of Zagreb is a education organization based out in Zagreb, Grad Zagreb, Croatia. It is known for research contribution in the topics: Population & European union. The organization has 21769 authors who have published 50267 publications receiving 783239 citations. The organization is also known as: Zagreb University & Sveučilište u Zagrebu.

Effect of Combined Systolic and Diastolic Functional Parameter Assessment for Differentiation of Cardiac Amyloidosis From Other Causes of Concentric Left Ventricular Hypertrophy

Abstract: Background— Differentiation of cardiac amyloidosis (CA) from other causes of concentric left ventricular hypertrophy remains a clinical challenge, especially in patients with preserved ejection fraction at the early disease stages. Methods and Results— Consecutive hypertrophic patients with CA, isolated arterial hypertension, Fabry disease, and Friedreich ataxia (n=25 per group) were investigated; 25 healthy volunteers served as a control group. Standard echocardiography was performed, and segmental longitudinal peak systolic strain (LSsys) in the septum was assessed by 2-dimensional speckle tracking imaging. Indices of left ventricular hypertrophy and ejection fraction were similar among all patient groups. Deceleration time of early filling was significantly lower in patients with CA (147±46 milliseconds) compared with those with isolated arterial hypertension, Fabry disease, or control subjects (all P 0.05). A data-driven cutoff value for the ratio of septal apical to basal LSsys ratio >2.1 differentiated CA from other causes of left ventricular hypertrophy (sensitivity, 88%; specificity, 85%; positive predictive value, 67%; negative predictive value, 96%). The prevalence of septal apical to basal LSsys ratio >2.1 plus deceleration time of early filling <200 milliseconds was 88% in CA but 0% in all other groups. Conclusions— A systolic septal longitudinal base-to-apex strain gradient (septal apical to basal LSsys ratio >2.1), combined with a shortened diastolic deceleration time of early filling (deceleration time of early filling <200 milliseconds), aids in differentiating CA from other causes of concentric left ventricular hypertrophy.

Global patterns and drivers of ecosystem functioning in rivers and riparian zones

Abstract: River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth’s biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented “next-generation biomonitoring” by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale.

Azimuthal anisotropy of D-meson production in Pb-Pb collisions at √sNN=2.76 TeV

Abstract: The production of the prompt charmed mesons D0, D+, and D*+ relative to the reaction plane was measured in Pb-Pb collisions at a center-of-mass energy per nucleon-nucleon collision of √sNN=2.76TeV with the ALICE detector at the CERN Large Hadron Collider. D mesons were reconstructed via their hadronic decays at central rapidity in the transverse-momentum (p_T) interval 2–16 GeV/c. The azimuthal anisotropy is quantified in terms of the second coefficient v2 in a Fourier expansion of the D-meson azimuthal distribution and in terms of the nuclear modification factor R_AA, measured in the direction of the reaction plane and orthogonal to it. The v2 coefficient was measured with three different methods and in three centrality classes in the interval 0%–50%. A positive v2 is observed in midcentral collisions (30%–50% centrality class), with a mean value of 0.204+0.099−0.036 (tot. unc.) in the interval 2

Quantifying and modeling long-range cross correlations in multiple time series with applications to world stock indices

Abstract: We propose a modified time lag random matrix theory in order to study time-lag cross correlations in multiple time series. We apply the method to 48 world indices, one for each of 48 different countries. We find long-range power-law cross correlations in the absolute values of returns that quantify risk, and find that they decay much more slowly than cross correlations between the returns. The magnitude of the cross correlations constitutes “bad news” for international investment managers who may believe that risk is reduced by diversifying across countries. We find that when a market shock is transmitted around the world, the risk decays very slowly. We explain these time-lag cross correlations by introducing a global factor model (GFM) in which all index returns fluctuate in response to a single global factor. For each pair of individual time series of returns, the cross correlations between returns (or magnitudes) can be modeled with the autocorrelations of the global factor returns (or magnitudes). We estimate the global factor using principal component analysis, which minimizes the variance of the residuals after removing the global trend. Using random matrix theory, a significant fraction of the world index cross correlations can be explained by the global factor, which supports the utility of the GFM. We demonstrate applications of the GFM in forecasting risks at the world level, and infinding uncorrelated individual indices. We find ten indices that are practically uncorrelated with the global factor and with the remainder of the world indices, which is relevant information for world managers in reducing their portfolio risk. Finally, we argue that this general method can be applied to a wide range of phenomena in which time series are measured, ranging from seismology and physiology to atmospheric geophysics.

Inclusive charged hadron elliptic flow in Au + Au collisions at √sNN=7.7–39 GeV

Abstract: A systematic study is presented for centrality, transverse momentum (p(T)), and pseudorapidity (eta) dependence of the inclusive charged hadron elliptic flow (v(2)) at midrapidity (vertical bar eta vertical bar < 1.0) in Au + Au collisions at root s(NN) = 7.7, 11.5, 19.6, 27, and 39 GeV. The results obtained with different methods, including correlations with the event plane reconstructed in a region separated by a large pseudorapidity gap and four-particle cumulants (v(2){4}), are presented to investigate nonflow correlations and v(2) fluctuations. We observe that the difference between v(2){2} and v(2){4} is smaller at the lower collision energies. Values of v(2), scaled by the initial coordinate space eccentricity, v(2)/epsilon, as a function of p(T) are larger in more central collisions, suggesting stronger collective flow develops in more central collisions, similar to the results at higher collision energies. These results are compared to measurements at higher energies at the Relativistic Heavy Ion Collider (root s(NN) = 62.4 and 200 GeV) and at the Large Hadron Collider (Pb + Pb collisions at root s(NN) = 2.76 TeV). The v(2)(pT) values for fixed pT rise with increasing collision energy within the pT range studied (<2 GeV/c). A comparison to viscous hydrodynamic simulations is made to potentially help understand the energy dependence of v(2)(pT). We also compare the v(2) results to UrQMD and AMPT transport model calculations, and physics implications on the dominance of partonic versus hadronic phases in the system created at beam energy scan energies are discussed.