A Spitzer Study of Interacting Luminous and Ultra-Luminous Infrared Galaxies

We conducted a Spitzer Space Telescope survey of 28 Luminous (11 < log(LIR/L_odot) < 12, LIRGs) and Ultra-Luminous Infrared Galaxies (log(LIR/L_odot) > 12, ULIRGs). Many of these galaxies are found in pairs or associations and are powered by either nuclear activity or starformation (Sanders & Mirabel 1996). Our main goal is to understand the relative importance of starbursts and AGNs in interacting systems. Is the frequency of AGN and starbursts in these interacting galaxies related to their luminosities? What is the importance of the merger stage and the frequency of AGNs? We present our conclusions and diagnostic diagrams based in the observed near infrared lines and compare to studies based solely in optical data.Comment: 3 pages, 2 figures, to appear in the Spectral Energy Distribution of Galaxies (SED2011) conference proceedings, Preston, UK, 201

Industries, citizens, and non-governmental organizations’ positioning and arguments used in European Union initiatives for alcohol taxation and cross-border regulation

Background: The European region has the highest daily alcohol consumption per capita and a high alcohol-related burden of disease. Policymaking at the European Union level is open to participation by interest groups, from public health organizations to alcohol industry representatives. This study aimed to map the interest groups present in the alcohol taxation and cross-border regulation initiatives and identify which arguments were used to support positions in favor or against them. Methods: We used qualitative content analysis on the comments submitted on the official European Commission website during the 2017, 2018, 2020, and 2022 participation periods. Interest groups were characterized considering their positioning, and arguments were identified and compared by position and type of initiative. Results: Opponents of changes to the structures of alcohol excise duties and cross-border regulations were mostly representatives of the alcohol and agricultural industries, and the proponents were mostly health-related nongovernmental organizations. Opponents of these initiatives used a wide variety of arguments, from economic and trade to health arguments, while proponents focused mainly on health arguments, such as the effectiveness of alcohol taxation in preventing alcohol-related morbidity and mortality. Conclusion: This study highlights the wide range of arguments used by opponents around alcohol control policies, contrasting with the health-centered arguments of proponents. It further shows that there is a lobbying network at the European Union level, combining national and international representatives of industry and non-governmental organizations. These findings provide an opportunity for better preparation for upcoming discussions on alcohol control at national and regional levels. © 2024 The Author(s)The authors thank the contributions of the Scientific Committee of the Institute of Public Health of Porto University on the review of this manuscript. This work was supported by FCT - Fundação para a Ciência e Tecnologia, I.P. through the projects with references UIDB/04750/2020 and LA/P/0064/2020 and DOI identifiers https://doi.org/10.54499/UIDB/04750/2020 and https://doi.org/10.54499/LA/P/0064/2020. The funders of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the manuscript

On the Price of German Treasury Bills

In this paper, we examine the primary and secondary markets for German treasury bills. We look in great detail at the rationale behind banks’ decisions concerning the yield they require to be willing to buy treasury bills in the primary market; and we also mention the reasoning behind household and nonbank firm decisions concerning the price they are willing to pay to buy these bills in the secondary market. We use data from real world tenders to show that the bids set by banks conform to what our theoretical framework would predict. In particular, we show that current monetary policy and the markets’ expectations regarding its future path can be used to define a range where the banks bids lie.FC

Wavelets: a powerful tool for studying rotation, activity, and pulsation in Kepler and CoRoT stellar light curves

Aims. The wavelet transform has been used as a powerful tool for treating several problems in astrophysics. In this work, we show that the time-frequency analysis of stellar light curves using the wavelet transform is a practical tool for identifying rotation, magnetic activity, and pulsation signatures. We present the wavelet spectral composition and multiscale variations of the time series for four classes of stars: targets dominated by magnetic activity, stars with transiting planets, those with binary transits, and pulsating stars. Methods. We applied the Morlet wavelet (6th order), which offers high time and frequency resolution. By applying the wavelet transform to the signal, we obtain the wavelet local and global power spectra. The first is interpreted as energy distribution of the signal in time-frequency space, and the second is obtained by time integration of the local map. Results. Since the wavelet transform is a useful mathematical tool for nonstationary signals, this technique applied to Kepler and CoRoT light curves allows us to clearly identify particular signatures for different phenomena. In particular, patterns were identified for the temporal evolution of the rotation period and other periodicity due to active regions affecting these light curves. In addition, a beat-pattern signature in the local wavelet map of pulsating stars over the entire time span was also detected.Comment: Accepted for publication on A&

A contribution to the study of the German treasury bills market

We study the yields in the German treasury bills market. We take a detailed look at the yield banks require to buy treasury bills in the primary market, and we also examine the yield households and nonbank firms demand to buy these bills in the secondary market. We use data from real world tenders to show that the bids set by banks are in accordance with the predictions of our theoretical framework. In particular, we show that current monetary policy and the market's expectations regarding the future path of monetary policy can be used to define an interval in which the bids from banks lie. Our theoretical predictions for the secondary market also match the data.info:eu-repo/semantics/publishedVersio

Dynamics of the public-debt-to-gdp ratio: Can it explain the risk premium of treasury bonds?

We examine the relationship between the risk premium markets demand to hold the Treasury Bonds of a given country and the sustainability of the public finances of the country. We inquire to what extent do markets use the dynamic evolution of the public-debt-to-gdp ratio as an indication of the likelihood of a public debt default. Specifically, our empirical research design involves the following steps: (i) we use the dynamic equation of the public-debt-to-gdp ratio to build forecasts of future values of this ratio in the eurozone countries; (ii) we then use these forecasts in a regression to see how important they are to explain the risk premium implicit in the treasury bond yields. We find that projections of future values of the public-debt-to-gdp ratio do impact current 10 year bond spreads. According to our regressions, markets seem to give more weight to forecasts with a horizon smaller than 10 years. Our results suggest that agents use a relatively simple mechanism to forecast the public debt-to-gdp ratio, a mechanism which can be used while updated forecasts from international organizations are not yet available. On the other hand, according to our estimations, euro area sovereign debt markets ceased to significantly discriminate countries based on their public debt prospects after the 2012 ‘Whatever It Takes” speech and the announcement of the Outright Monetary Transactions (OMT) program—suggesting that these events had a significant calming effect on the markets