Cepheid theoretical models and observations in HST/WFC3 filters: the effect on the Hubble constant Ho

We present a complete theoretical scenario for classical Cepheids in the most commonly used HST/WFC3 filters, going from optical (F555W, F606W and F814W) to near-infrared (F160W) bands. The importance of such a study is related to the recent release of new classical Cepheids observed with HST/WFC3 in 8 distant galaxies where SNIa are hosted. These observations have posed sound constraints to the current distance scale with uncertainties on the Hubble constant Ho smaller than 3%. Our models explore a large range of metallicity and Helium content, thus providing a robust and unique theoretical tool for describing these new and future HST/WFC3 observations. As expected, the Period-Luminosity (PL) relation in F160W filter is linear and slightly dependent on the metallicity when compared with optical bands, thus it seems the most accurate tool to constrain extragalactic distances with Cepheids. We compare the pulsation properties of Cepheids observed with HST/WFC3-IR with our theoretical scenario and we discuss the agreement with the predicted Instability Strip for all the investigated galaxy samples including the case of NGC4258. Finally, adopting our theoretical F160W PL relation for Z=0.02 and log P>1.0, we derive new distance moduli. In particular, for NGC 4258, we derive a distance modulus mu0 = 29.345 +- 0.004 mag with a sigma = 0.34 mag, which is in very good agreement with the geometrical maser value. Moreover, using the obtained distance moduli, we estimate the Hubble constant value, Ho=76.0 +- 1.9 km s-1 Mpc-1 in excellent agreement with the most recent literature values.Comment: 13 pages, 9 figures, 4 tables, MNRAS, accepte

Economic losses in tourism during the COVID-19 pandemic. The case of Sorrento

The tourism sector is facing its most severe crisis under the COVID-19 pandemic. Social distancing measures, global travel restrictions, stay-athome orders, and other lockdown measures brought tourism to a halt in 2020. We estimate the potential economic losses thereof in terms of added value and number of tourists by nationality. By using the city of Sorrento as prominent and representative case study, we implement time-series analysis with autoregressive-integrated moving average models on monthly data from January 2013 to December 2019. We thus forecast the loss of tourists and added value in 2020. The results reveal that the pandemic has significantly affected the tourism sector, the added value of tourism in Sorrento might decrease by over 70%, and tourist arrivals might similarly fall or even reach zero foreign arrivals. The local government should reassess the sustainability of tourism proposals by factoring in the lack of tourist arrivals and focusing on loyal tourists and proximity tourists, two fundamental target audiences

Campania and cancer mortality: An inseparable pair? The role of environmental quality and socio-economic deprivation

The region of Campania in Southern Italy features high levels of socio-economic deprivation and low levels of environmental quality. A vast strand of the scientific literature has tried to verify whether poor environmental quality and widespread socio-economic deprivation might explain the high cancer mortality rates (CMRs) observed, especially in the municipalities – infamously labelled as the ‘Land of Fires’ – that were hit most severely by the crisis. While some studies managed to identify links between these two confounding factors and cancer mortality, the evidence is overall mixed. Interesting information may be drawn from the observation of municipal data: in spite of previous claims, some municipalities featuring high environmental quality and low socio-economic deprivation also display high CMRs, while other Campanian municipalities facing disastrous environmental and socio-economic conditions are characterised by low CMRs. These figures, in contrast to common sentiment and previous studies, need to be investigated thoroughly in order to assess the exact role of the confounding factors. In this work, we aim to identify the municipalities where confounding factors act as driving forces in the determination of high CMRs through an original multi-step analysis based on frequentist and Bayesian analysis. Pinpointing these municipalities could allow policymakers to design targeted and effective policy measures aimed at reducing cancer mortality

Inequality and regressivity in Italian waste taxation. Is there an alternative route?

The Italian financing system for waste collection and disposal services, still far from a price-based system at the national level, is similar to a real property tax system. Among other concerns, this raises equity issues. The aim of this paper is threefold. First, the structure of the waste tax in its components (i.e., fixed and variable) is analysed at the provincial level. This allows to investigate the magnitude of the two tax components in Italian provinces, while showing the differences among macro-areas in the financing system for waste collection and disposal services. Second, the regressivity (progressivity) of the tax system adopted is investigated, so as to highlight the differences among geographical areas. Third, an alternative base for the waste tax is proposed, in order to avoid regressivity and achieve higher equality. For these purposes, official data referring to 2017 are used and a Geographically Weighted Regression is implemented. The results highlight the importance of an alternative base of the waste tax to design an equal and non-regressive tax, more similar to a Pay-As-You-Throw scheme

Does national environmental regulation promote convergence in separate waste collection? Evidence from Italy

In the European Union, which is increasingly oriented towards environmentally sustainable development, separate waste collection plays a crucial role. Over the years, the EU has produced several guidelines, programmes and directives aimed to build a green society and tone down the differences between, as well as within, Member States. In Italy, the waste management system is currently regulated by Legislative Decree 152/2006, through which European directives have been incorporated into the Italian law. The existing literature has focused on the effects of L.D. 152/2006 on Separate Waste Collection (SWC) rates; however, there are not previous studies on the effects of this decree on growth rates and on convergence process among regions in terms of SWC and its items (i.e., organic, plastic, paper, and glass). This paper aims to fill these gaps. For this purpose, we implement b- and s-convergence analysis based on Generalised Method of Moments (GMM) on official Italian regional data over the period 2001e2018. Results show that Legislative Decree 152/2006 has two contrasting effects: on the one hand, it helped increase separate waste collection; on the other hand, it slowed down the convergence process in terms of separate waste collection among the Italian regions. However, the convergence process is characterised by different speeds across Italian macro-areas (Northern, Central, and Southern Italy), highlighting a three-speed country. To foster convergence, the national legislation should consider regional differences in terms of economic, infrastructural, institutional, social, and demographic characteristics

On a new theoretical framework for RR Lyrae stars I: the metallicity dependence

We present new nonlinear, time-dependent convective hydrodynamical models of RR Lyrae stars computed assuming a constant helium-to-metal enrichment ratio and a broad range in metal abundances (Z=0.0001--0.02). The stellar masses and luminosities adopted to construct the pulsation models were fixed according to detailed central He burning Horizontal Branch evolutionary models. The pulsation models cover a broad range in stellar luminosity and effective temperatures and the modal stability is investigated for both fundamental and first overtones. We predict the topology of the instability strip as a function of the metal content and new analytical relations for the edges of the instability strip in the observational plane. Moreover, a new analytical relation to constrain the pulsation mass of double pulsators as a function of the period ratio and the metal content is provided. We derive new Period-Radius-Metallicity relations for fundamental and first-overtone pulsators. They agree quite well with similar empirical and theoretical relations in the literature. From the predicted bolometric light curves, transformed into optical (UBVRI) and near-infrared (JHK) bands, we compute the intensity-averaged mean magnitudes along the entire pulsation cycle and, in turn, new and homogenous metal-dependent (RIJHK) Period-Luminosity relations. Moreover, we compute new dual and triple band optical, optical--NIR and NIR Period-Wesenheit-Metallicity relations. Interestingly, we find that the optical Period-W(V,B-V) is independent of the metal content and that the accuracy of individual distances is a balance between the adopted diagnostics and the precision of photometric and spectroscopic datasets.Comment: 51 pages, 20 figures, 9 tables, accepted for publication on Ap