A continuous population of variable stars up to about 1.5 mag above the horizontal branch?

Increasing samples of pulsating variable stars populating the classical instability strip from the horizontal branch to a few magnitudes brighter are being found in several Local Group galaxies, irrespective of the galaxy morphological type. We will review the observational scenario focusing in particular on the Anomalous Cepheids and related objects.Comment: 5 pages, 2 figures, invited review in JENAM 2003, "Minisymposium: Asteroseismology and Stellar Evolution", Communications in Asteroseismology, in pres

Interferometric control of absorption in thin plasmonic metamaterials: General two port theory and broadband operation

In order to extend the Coherent Perfect Absorption (CPA) phenomenology to broadband operation, the interferometric control of absorption is investigated in two-port systems without port permutation symmetry. Starting from the two-port theory of CPA treated within the Scattering Matrix formalism, we demonstrate that for all linear two-port systems with reciprocity the absorption is represented by an ellipse as function of the relative phase and intensity of the two input beams, and it is uniquely determined by the device single-beam reflectance and transmittance, and by the dephasing of the output beams. The basic properties of the phenomenon in systems without port permutation symmetry show that CPA conditions can still be found in such asymmetric devices, while the asymmetry can be beneficial for broadband operation. As experimental proof, we performed transmission measurements on a metal-semiconductor metamaterial, employing a Mach-Zehnder interferometer. The experimental results clearly evidence the elliptical feature of absorption and trace a route towards broadband operation

The global burden of chronic respiratory diseases

Key points Currently, the serious consequences of chronic diseases and their risk factors are not fully recognised by the international health community. In the period of 1990–2020, COPD deaths are expected to increase from 2.2 to 4.7 million worldwide. Reducing chronic disease death rates by an additional 2% annually would avert 36 million deaths by 2015. The abatement of the main risk factors for respiratory diseases, in particular tobacco smoking, environmental tobacco smoke, indoor biomass fuels, outdoor air pollution and unhealthy diet, can achieve huge health benefits. Educational aims To define the burden of chronic respiratory diseases all over the world. To underline the importance of chronic diseases recognition by the international health community. To provide details about the burden of chronic obstructive pulmonary disease (COPD): the predicted third cause of death by 2020. Summary Currently, the serious consequences of chronic diseases and their risk factors are not fully recognised by the international health community. Moreover, chronic diseases are not only a problem of the ageing population in developed countries. In fact, it has been estimated that 80% of mortality for chronic diseases occurred in low-income and middleincome countries in 2005. Thus, the World Health Organization (WHO) Dept of Chronic Diseases and Health Promotion has suggested a new Millennium Development Goal for the next few years: to reduce chronic disease death rates by an additional 2% annually, in order to avert 36 million deaths by 2015