Search results for "CLIMATE"
showing 10 items of 4934 documents
Stochastic gravito-inertial modes discovered by CoRoT in the hot Be star HD 51452
2012
International audience; Context. Be stars are rapidly rotating stars with a circumstellar decretion disk. They usually undergo pressure and/or gravity pulsation modes excited by the κ-mechanism, i.e. an effect of the opacity of iron-peak elements in the envelope of the star. In the Milky Way, p-modes are observed in stars that are hotter than or equal to the B3 spectral type, while g-modes are observed at the B2 spectral type and cooler. Aims. We observed a B0IVe star, HD 51452, with the high-precision, high-cadence photometric CoRoT satellite and high-resolution, ground-based HARPS and SOPHIE spectrographs to study its pulsations in great detail. We also used the lower resolution spectra a…
Chemical Cartography with APOGEE: Multi-element Abundance Ratios
2019
We map the trends of elemental abundance ratios across the Galactic disk, spanning R = 3-15 kpc and midplane distance |Z|= 0-2 kpc, for 15 elements in a sample of 20,485 stars measured by the SDSS/APOGEE survey (O, Na, Mg, Al, Si, P, S, K, Ca, V, Cr, Mn, Fe, Co, Ni). Adopting Mg rather than Fe as our reference element, and separating stars into two populations based on [Fe/Mg], we find that the median trends of [X/Mg] vs. [Mg/H] in each population are nearly independent of location in the Galaxy. The full multi-element cartography can be summarized by combining these nearly universal median sequences with our measured metallicity distribution functions and the relative proportions of the lo…
The Gaia-ESO Survey: impact of extra mixing on C and N abundances of giant stars
2018
The GES survey using FLAMES at the VLT has obtained high-resolution UVES spectra for a large number of giant stars, allowing a determination of the abundances of the key chemical elements C and N at their surface. The surface abundances of these chemical species are well-known to change in stars during their evolution on the red giant branch after the first dredge-up episod, as a result of extra-mixing phenomena. We investigate the effects of thermohaline mixing on C and N abundances using the first comparison between the GES [C/N] determinations with simulations of the observed fields using a model of stellar population synthesis. We explore the effects of thermohaline mixing on the chemic…
Stress appraisal at work: its measurement and implications for well-being
2013
En los cinco artículos que forman parte de la presente tesis, se han comentado los conceptos subyacentes así como los resultados obtenidos. En este apartado, se resaltan los objetivos de la presente tesis, la metodología utilizada, así como las conclusiones generales que se pueden extraer en base a los estudios realizados. Objetivos En esta tesis analizamos el fenómeno del estrés laboral desde la perspectiva cognitiva (Lazarus y Folkman, 1984) y desde el enfoque que nos ofrece la psicología positiva (Seligman y Csikszentmihayi, 2000). El objetivo de la presente tesis ha sido desarrollar y validar una nueva medida de la percepción de eustrés y distrés tanto desde la Teoría Clásica del Test (…
SOSTENIBILITÀ E RESILIENZA DELL’AGRICOLTURA DOPO LA PANDEMIA COVID-19
2020
1. Introduzione. – 2. Agenda 2030 ONU sviluppo sostenibile. – 3. Misure restrittive del COVID-19 e impatto sul mercato dei lavoratori agricoli. – 4. Etica della utilizzazione del suolo: agricoltura biologica, agricoltura urbana, permacoltura. – 5. Le funzioni ecosistemiche del suolo dopo il COVID-19. – 6. La salvaguardia del suolo per mitigare i cambiamenti climatici. – 7. La degradazione del suolo e la sicurezza alimentare. – 8. Prospettive dell’agricoltura italiana dopo il COVID-19.
Global analysis of the pMSSM in light of the Fermi GeV excess: prospects for the LHC Run-II and astroparticle experiments
2016
We present a new global fit of the 19-dimensional phenomenological Minimal Supersymmetric Standard Model (pMSSM-19) that comply with all the latest experimental results from dark matter indirect, direct and accelerator dark matter searches. We show that the model provides a satisfactory explanation of the excess of gamma-rays from the Galactic centre observed by the Fermi~Large Area Telescope, assuming that it is produced by the annihilation of neutralinos in the Milky Way halo. We identify two regions that pass all the constraints: the first corresponds to neutralinos with a mass ~80-100 GeV annihilating into WW with a branching ratio of 95% ; the second to heavier neutralinos, with mass ~…
Economical evaluation of ecological benefits of the demand side management
2014
Environmental pollution and over-exploitation of non-renewable sources to find energy are current topics for the modern world that is now at having to deal with several issues such as the greenhouse effect, acid rain and climate change. In this study, the economical estimate of the savings in carbon dioxide obtained with a careful management of electrical loads is presented. Four particular scenarios are designed as case studies: Italy, France, United Kingdom and Germany. A comparison is presented with a similar study, made in 2007, when green energies were not yet very developed.
Grazing intensity in subarctic tundra affects the temperature adaptation of soil microbial communities
2015
Abstract Grazing by large ungulates, such as reindeer (Rangifer tarandus L.), in subarctic tundra exerts a considerable effect on the soil microclimate. Because of higher insulation by the aboveground vegetation in light versus heavily grazed areas, soil temperatures during the growing season are considerably higher under heavy grazing. Here, we hypothesized that these grazer-induced changes in soil microclimate affect the temperature sensitivity of soil microbial activity. To test this hypothesis, we conducted soil incubations at different temperatures (4 °C, 9 °C and 14 °C) for six weeks using soils from sites with contrasting long-term grazing intensities. Microbial respiration at low te…
Global, National, or Market? Emerging REDD+ Governance Practices in Mozambique and Tanzania
2016
This article examines emerging governance practices in the REDD (Reducing Emissions from Deforestation and Forest Degradation) initiative. We examine three different general governance practices (neoliberal, post-national, and government-led practices) that have been applied in the interaction between international organizations and two REDD target countries: Mozambique and Tanzania. In these countries, we find that emerging REDD+ governance practices are a mixture of international organizations’ procedural practices and the target country’s established governance practices, whereas neoliberal practices are weakly expressed. These findings call into question the simplified assumption of re…
Assessing travel time-based accessibility to outdoor ice skating fields for children in Helsinki during the COVID-19 pandemic
2022
This paper was written within the research project called “Equality in suburban physical activity environments, YLLI” (in Finnish: Yhdenvertainen liikunnallinen lähiö, YLLI) funded by the Suburban Programme 2020–2022 (in Finnish: Lähiöohjelma 2020–2022, decision number VN/10837/2020). Informal sport is central to Finnish children’s leisure and physical activity time. This paper aims to build a better understanding of the travel time-based accessibility to informal sports facilities, specifically to ice skating fields, for children and adolescents (aged 7–19) in the city of Helsinki. We focused on the winter of 2020–2021 because COVID-19 restrictions on indoor activities resulted in ice skat…