Spectral analysis of stochastic and analytic simulation results for a nonlinear model for the Italian economy

When dealing with nonlinear econometric models, resort is often made to simulation techniques for the investigation of their dynamic properties. A spectral analysis using stochastic and analytic simulation is carried out on a nonlinear model of the Italian economy. The two approaces are empirically compared

Simple model for quantum general relativity from loop quantum gravity

New progress in loop gravity has lead to a simple model of `general-covariant quantum field theory'. I sum up the definition of the model in self-contained form, in terms accessible to those outside the subfield. I emphasize its formulation as a generalized topological quantum field theory with an infinite number of degrees of freedom, and its relation to lattice theory. I list the indications supporting the conjecture that the model is related to general relativity and UV finite.Comment: 8 pages, 3 figure

Generalized instantons in N = 4 super Yang-Mills theory and spinorial geometry

Using spinorial geometry techniques, we classify the supersymmetric solutions of euclidean ${\cal N}=4$ super Yang-Mills theory. These backgrounds represent generalizations of instantons with nontrivial scalar fields turned on, and satisfy some constraints that bear a similarity with the Hitchin equations, and contain the Donaldson equations as a special subcase. It turns out that these constraints can be obtained by dimensional reduction of the octonionic instanton equations, and may be rephrased in terms of a selfduality-like condition for a complex connection. We also show that the supersymmetry conditions imply the equations of motion only partially.Comment: 29 pages, 3 tables. v2: references added. v3: conclusion extended, version published in JHE

Spectral analysis of stochastic and analytic simulation results for a nonlinear model for the Italian economy

When dealing with nonlinear econometric models, resort is often made to simulation techniques for the investigation of their dynamic properties. A spectral analysis using stochastic and analytic simulation is carried out on a nonlinear model of the Italian economy. The two approaces are empirically compared.Stochastic simulation; nonlinear econometric models; analytic simulation; spectral analysis; Monte Carlo methods

An Atlas of Monte Carlo Models of Dust Extinction in Galaxies for Cosmological Applications

We present an extensive study of the radiative transfer in dusty galaxies based on Monte Carlo simulations. The main output of these simulations are the attenuation curves ${\cal A}_\lambda$ (i.e. the ratio between the observed, dust extinguished, total intensity to the intrinsic unextinguished one of the galaxy as a function of wavelength). We have explored the dependence of ${\cal A}_\lambda$ on a conspicuous set of quantities (Hubble type, inclination, dust optical thickness, dust distribution and extinction properties) for a large wavelength interval, ranging from 1250\AA to the K band, thus finally providing a comprehensive atlas of dust extinction in galaxies, which is electronically available. This study is particularly suitable for inclusion into galaxy formation evolution models and to directly interpret observational data on high redshift galaxies.Comment: 29 pages, aasms4.sty, LaTeX, 5 figures. ApJSS, accepte

A reappraisal of the bladder cumulative method as a reliable technique for the measurement of glomerular filtration rate.

In order to quantify the decline in renal function, repeated measurements of GFR are necessary. The conventional procedure is cumbersome and time expending so that alternative clearance techniques are needed. We propose a simple isotopic technique for measuring GFR by 99mTc-DTPA and external counting of the bladder by gamma camera (bladder cumulative method). This consists in the measurement by external counting of the amount of labelled filtration marker accumulated in the bladder after intravenous bolus injection. In 36 adult patients with all degrees of renal impairment (serum creatinine 0.9-9.3 mg/dL) GFR was measured twice, once by the conventional method (continuous i.v. infusion of the filtration marker and urine collection by spontaneous voiding) and once by the bladder cumulative method. 99mTc DTPA was used in performing both methods. A satisfactory agreement was found between GFR measured by bladder cumulative method (BCM) and by conventional method (CM). The BCM averaged 60.0 +/- 36.7 mL/min and the CM +/- SD averaged 62.8 +/- 36.6 mL/mm. The ratio BCM/CM +/- SD was 0.95 +/- 0.14 (y = 0.94x + 1.14; r = 0.94). Considering the 17 patients with renal insufficiency (GFR60 mL/min) an even better agreement between the two methods was found. In these patients the BCM averaged 28.4 +/- 17.2 mL/min; the CM averaged 29.1 +/- 16.6 mL/min; and the ratio BCM/CM was 0.96 +/- 0.08 (y = 1.03x - 1.47; r = 0.99). The day-to-day variability of BCM, studied in another 11 patients, was lower than that of creatinine clearance (variation coefficient for duplicate measurements: 7.18 +/- 6.65 SD for BCM, 15.68 +/- 8.80 SD for CM, p0.01). The bladder cumulative method is a simple procedure for the accurate measurement of GFR, in particular in patients with renal insufficiency. It represents a reliable tool for estimating the decline in renal function

Euclidean three-point function in loop and perturbative gravity

We compute the leading order of the three-point function in loop quantum gravity, using the vertex expansion of the Euclidean version of the new spin foam dynamics, in the region of gamma<1. We find results consistent with Regge calculus in the limit gamma->0 and j->infinity. We also compute the tree-level three-point function of perturbative quantum general relativity in position space, and discuss the possibility of directly comparing the two results.Comment: 16 page

Navigating challenges:STI policies for sustainable and inclusive development in Latin America

This paper explores the challenges and opportunities for Latin America in adopting sustainable development strategies, with a particular focus on Science, Technology and Innovattion (STI) policies. It gathers the insights of a group of distinguished scholars on STI policies, social inclusion and sustainability from the region who participated in the panel organized by the UNESCO Chair during the LALICS* conference held in Asuncion, Paraguay, on 19-21 June 2023.It addresses the challenges that hinder Latin America’s inclusive, sustainable and innovative development process from different perspectives. Highlighted challenges include strong inequality, high informality levels, and low R&amp;D expenditure, heterogeneous productive structure posing obstacles to innovation and their governance. Scholars highlight the role of STI policies and the engagement of academia, government, and business in reducing inequality and promoting social protection, and discuss the technological capabilities needed to address climate change and digitalisation in the region

Navigating challenges:STI policies for sustainable and inclusive development in Latin America

This paper explores the challenges and opportunities for Latin America in adopting sustainable development strategies, with a particular focus on Science, Technology and Innovattion (STI) policies. It gathers the insights of a group of distinguished scholars on STI policies, social inclusion and sustainability from the region who participated in the panel organized by the UNESCO Chair during the LALICS* conference held in Asuncion, Paraguay, on 19-21 June 2023.It addresses the challenges that hinder Latin America’s inclusive, sustainable and innovative development process from different perspectives. Highlighted challenges include strong inequality, high informality levels, and low R&amp;D expenditure, heterogeneous productive structure posing obstacles to innovation and their governance. Scholars highlight the role of STI policies and the engagement of academia, government, and business in reducing inequality and promoting social protection, and discuss the technological capabilities needed to address climate change and digitalisation in the region