Multiple stellar populations in Globular Clusters: collection of information from the Horizontal Branch

The majority of the inhomogeneities in the chemical composition of Globular Cluster (GC) stars appear due to primordial enrichment by hot-CNO cycled material processed in stars belonging to a first stellar generation. Either massive AGB envelopes subject to hot bottom burning, or the envelopes of massive fastly rotating stars could be the progenitors. In both cases, the stars showing chemical anomalies must have also enhanced helium abundance, and we have proposed that this higher helium could be at the basis of the many different morphologies of GC horizontal branches (HB) for similar ages and metallicities. The helium variations have been beautifully confirmed by the splitting of the main sequence in the clusters omega Cen and NGC 2808, but this effect can show up only for somewhat extreme helium abundances. Therefore it is important to go on using the HB morphology to infer the number ratio of the first to the second generation in as many clusters as possible. We exemplify how it is possible to infer the presence of a He-rich stellar component in different clusters thanks to different HB features (gaps, RR Lyr periods and period distribution, ratio of blue to red stars, blue tails). In many clusters at least 50% of the stars belong to the second stellar generation, and in some cases we suspect that the stars might all belong to the second generation. We shortly examine the problem of the initial mass function required to achieve the observed number ratios and conclude that: 1) the initial cluster must have been much more massive than today's cluster, and 2) formation of the second stellar generation mainly in the central regions of the cluster may help in obtaining the desired values.Comment: to appear in the Proceedings of IAU Symposium 246 ``Dynamical Evolution of Dense Stellar Systems", E. Vesperini, M. Gierzs & A. Sills, eds., Cambridge University Pres

Is mass loss along the red giant branch of globular clusters sharply peaked? The case of M3

There is a growing evidence that several globular clusters must contain multiple stellar generations, differing in helium content. This hypothesis has helped to interpret peculiar unexplained features in their horizontal branches. In this framework we model the peaked distribution of the RR Lyr periods in M3, that has defied explanation until now. At the same time, we try to reproduce the colour distribution of M3 horizontal branch stars. We find that only a very small dispersion in mass loss along the red giant branch reproduces with good accuracy the observational data. The enhanced and variable helium content among cluster stars is at the origin of the extension in colour of the horizontal branch, while the sharply peaked mass loss is necessary to reproduce the sharply peaked period distribution of RR Lyr variables. The dispersion in mass loss has to be <~ 0.003 Msun, to be compared with the usually assumed values of ~0.02 Msun. This requirement represents a substantial change in the interpretation of the physical mechanisms regulating the evolution of globular cluster stars.Comment: Accepted for publication in The Astrophysical Journa

Consumer Footprint. Basket of Products indicator on Housing

The EU Consumer Footprint aims at assessing the potential environmental impacts due to consumption. The calculation of the Consumer footprint is based on the life cycle assessment (LCA) of representative products (or services) purchased and used in one year by an EU citizen. This report is about the consumer footprint indicators of the basket of product (BoP) on housing. In order to assess the environmental impact of EU housing consumption, a LCA-based methodology has been applied to twenty-four representative dwellings (basket of products), modelled on the basis of the type of building (single or multifamily houses), the year of construction (four timeframes), and the climate zone (three zones) in which they are located. One of the main novelty of this work is the definition of twenty-four archetypes of buildings, changing the construction materials and the building specific features affecting the inventory for each archetype. The resulting baseline inventory model, referring to the year 2010, was assessed for 15 different impact categories, using the ILCD LCIA method. A sensitivity analysis has been run for some impact categories, with a selection of recent impact assessment models and factors. Results allows a wide array of considerations, as this study reports overall impact in Europe, average impact per citizen, share of impact due to dwelling typology and climate areas, as well as impact of each dwelling type per climate zone per year of construction. Single-family houses are responsible for the highest share of impacts. The same type of building has different impacts in different climatic zones, especially because cold climate requires higher input of resources for space heating. The overall results reveal that the use phase (energy and water consumption) dominates the impacts, followed by the production of construction materials. In general, electricity use and space heating are the activities that contribute the most to the overall impacts. Depending on the normalisation reference used (European or global) the most important impact category present a different relative share. However, human toxicity, respiratory inorganics, resource depletion (metals, fossils, and water), climate change and ionising radiations show the highest impacts for all the normalization references. Since many LCA study on housing are limited to the assessment of climate change related emissions, the BoP housing baseline aims at helping understanding the wider array of impacts associated to the housing system and the potential areas of ecoinnovation improvement for reducing the burden. To assess potential benefits stemming from selected ecoinnovation, the Consumer Footprint BoP housing baseline has been assessed against nine scenarios, referring to improvement options related to the main drivers of impact. The nine scenarios covers both technological improvements and changes in consumers behaviour, entailing: 1. night attenuation of setting temperature for space heating; 2. external wall insulation with an increased thickness; 3. external wall insulation comparing conventional or bio-based materials; 4. use of a solar collector to heat sanitary water; 5. floor finishing with timber instead of ceramic tiles; 6. a building structure in timber compared with concrete frame; 7. implementation of smart windows for improved energy efficiency; 8. a combination of selected above mentioned energy-related scenarios; 9. production of electricity through a photovoltaic system installed on the roof. The assessment of the selected scenarios, acting on energy efficiency, resource efficiency, renewable energy and bio-based material (scenarios 1 to 7) revealed that the potential reduction in impact for each of the eco-innovation assessed is relatively limited and that a combination of actions is needed to achieve significant improvements. Moreover, in the case of scenarios acting on the substitution of specific components of the building, the potential improvement is proportional to the relative importance of the substituted component in the baseline scenario. However, a preliminary modelling of combination of energy-related measures (scenario 8) proved to be a good way to enlarge the potential benefits coming from the selected improvements of the building stock. The results highlight as well that LCA is fundamental for unveiling trade-off between benefits associated to eco-innovation and burden arising from their implementation.JRC.D.1-Bio-econom

The prion protein regulates glutamate-mediated Ca2+ entry and mitochondrial Ca2+ accumulation in neurons

The cellular prion protein (PrPC) whose conformational misfolding leads to the production of deadly prions, has a still-unclarified cellular function despite decades of intensive research. Following our recent finding that PrPC limits Ca2+ entry via store-operated Ca2+ channels in neurons, we investigated whether the protein could also control the activity of ionotropic glutamate receptors (iGluRs). To this end, we compared local Ca2+ movements in primary cerebellar granule neurons and cortical neurons transduced with genetically encoded Ca2+ probes and expressing, or not expressing, PrPC. Our investigation demonstrated that PrPC downregulates Ca2+ entry through each specific agonist-stimulated iGluR and after stimulation by glutamate. We found that, although PrP-knockout (KO) mitochondria were displaced from the plasma membrane, glutamate addition resulted in a higher mitochondrial Ca2+ uptake in PrP-KO neurons than in their PrPC-expressing counterpart. This was because the increased Ca2+ entry through iGluRs in PrP-KO neurons led to a parallel increase in Ca2+-induced Ca2+ release via ryanodine receptor channels. These data thus suggest that PrPC takes part in the cell apparatus controlling Ca2+ homeostasis, and that PrPC is involved in protecting neurons from toxic Ca2+ overloads

Festival Tocat\uec: una buona pratica nella tutela e valorizzazione dei beni culturali immateriali

Obiettivi. Il lavoro mira a comprendere in che termini il Tocat\uec, Festival Internazionale dei Giochi in Strada, promosso nel 2003 dall\u2019Associazione Giochi Antichi e considerato un evento di successo unico in Italia, possa rappresentare una buona pratica nella tutela e valorizzazione dei beni culturali immateriali e su quali determinanti poggia il suo successo. Metodologia. Il paper intende proporsi come un Case study. Dopo un inquadramento teorico sul tema oggetto di studio, si \ue8 provveduto alla raccolta di dati e informazioni di tipo qualitativo e quantitativo mediante la consultazione di fonti secondarie e lo svolgimento di interviste in profondit\ue0 con i responsabili del Tocat\uec. Risultati. L\u2019analisi svolta consente di evidenziare che il Festival pu\uf2 essere considerato una buona pratica per la salvaguardia del gioco tradizionale come patrimonio culturale immateriale. Lo studio ne traccia i lineamenti e pone in luce le determinanti alle quali pu\uf2 ricondursi il successo della manifestazione. Limiti della ricerca. Il caso \ue8 stato analizzato considerando solo la prospettiva del promotore dell\u2019evento. Per un approfondimento della ricerca si dovrebbe estendere l\u2019analisi considerando la prospettiva di un pi\uf9 ampio gruppo di stakeholder. Implicazioni pratiche. Pur presentando caratteri di non standardizzabilit\ue0 e di non facile riproducibilit\ue0, l\u2019evento analizzato come buona pratica offre l\u2019opportunit\ue0 di riflettere sugli elementi che possono favorire il successo di un festival culturale. Originalit\ue0 del lavoro. Non si rilevano in letteratura modelli per la valutazione degli eventi culturali come buona pratica. Si ritiene pertanto che questo lavoro offra un contributo al dibattito tuttora aperto sul tema a livello nazionale e internazionale

Toxic organic contaminants in airborne particles: levels, potential sources and risk assessment

In the last years, many studies have focused on risk assessment of exposure of workers to airborne particulate matter (PM). Several studies indicate a strong correlation between PM and adverse health outcomes, as a function of particle size. In the last years, the study of atmospheric particulate matter has focused more on particles less than 10 m or 2.5 m in diameter; however, recent studies identify in particles less than 0.1 m the main responsibility for negative cardiovascular effects. The present paper deals with the determination of 66 organic compounds belonging to six different classes of persistent organic pollutants (POPs) in the ultrafine, fine and coarse fractions of PM (PM &lt; 0.1 m; 0.1 &lt; PM &lt; 2.5 mand 2.5 &lt; PM &lt; 10 m) collected in three outdoor workplaces and in an urban outdoor area. Data obtained were analyzed with principal component analysis (PCA), in order to underline possible correlation between sites and classes of pollutants and characteristic emission sources. Emission source studies are, in fact, a valuable tool for both identifying the type of emission source and estimating the strength of each contamination source, as useful indicator of environment healthiness. Moreover, both carcinogenic and non-carcinogenic risks were determined in order to estimate human health risk associated to study sites. Risk analysis was carried out evaluating the contribution of pollutant distribution in PM size fractions for all the sites. The results highlighted significant differences between the sites and specific sources of pollutants related to work activities were identified. In all the sites and for all the size fractions of PM both carcinogenic and non-carcinogenic risk values were below acceptable and safe levels of risks recommended by the regulatory agencies

Algunos aspectos sobresalientes del empleo en el sector manufacturero colombiano

Este artículo tiene como propósito describir algunas de las características principales del sector manufacturero entre 2000 y 2013, con énfasis en la generación de empleo, y muestra la heterogeneidad geográfica, por subsectores y tamaños de los establecimientos.El artículo se desarrolla de la siguiente forma. La sección 1 examina el desempeño reciente del sector manufacturero y lo compara con el PIB. La sección 2 describe aspectos centrales de la heterogeneidad geográfica y sectorial. La siguiente sección analiza el empleo por tamaño de los establecimientos, mientras que la sección 4 lo hace por tipo de contrato. Posteriormente, la sección 5 hace un análisis de género. La última sección presenta algunas conclusiones