Search results for " climat"
showing 10 items of 4174 documents
El impacto del cambio climático en la movilidad humana : las migraciones climáticas en el contexto internacional y europeo
2021
For decades, the migration phenomenon has been one of the thorniest regulatory issues in the European Union (EU) policy. In addition, today, the fight against climate change in all regions of the world makes the situation worse for the new ?climate refugees? or ?environmental displaced people?, whose legal status is not yet covered by the ancient 1951 Refugee Convention.
Tide affects food availability in rock pools: evidence from Mediterranean intertidal habitats
2013
Service Climate and Display of Employees’ Positive Emotions: The Mediating Role of Burnout and Engagement in Services
2011
This article aims to test a model linking service climate to the frequency of expression of positive emotions by frontline employees. We propose that burnout and engagement at work mediate the relationship between service climate and the expression of positive emotions. Service climate impacts negatively on burnout and positively on engagement; in turn, burnout and engagement are significantly related to the frequency of expression of positive emotions. This model was tested both at the individual and work-unit levels. In addition, it was compared with a direct model that proposes an additional direct link from service climate to frontline employees’ positive emotions. Models were tested th…
Phase equilibria of Pantelleria trachytes (Italy): constraints on pre-eruptive conditions and on the metaluminous to peralkaline transition in silici…
2018
Pantelleria Island is the type locality of pantellerite, an iron and alkali-rich rhyolite (P.I=molar Na2O+K2O/Al2O3 >1.05). Peralkaline rhyolites (i.e pantellerite and comendite) and trachytes usually represent the felsic end-members in continental rift systems (e.g., Pantelleria, Tibesti, Ethiopia, Afar, Kenya, Bain and Range, South Greenland) and in oceanic sland settings (Socorro Is., Easter Is., Iceland and Azores). The origin of peralkaline rhyolites in the different tectonic settings is still a matter of debate and three hypotheses have been suggested: (a) crystal fractionation of alkali-basalt in a shallow reservoir to produce a trachyte which subsequently gives rise to a pantelle…
A Band Model of Cambium Development: Opportunities and Prospects
2021
More than 60% of tree phytomass is concentrated in stem wood, which is the result of periodic activity of the cambium. Nevertheless, there are few attempts to quantitatively describe cambium dynamics. In this study, we develop a state-of-the-art band model of cambium development, based on the kinetic heterogeneity of the cambial zone and the connectivity of the cell structure. The model describes seasonal cambium development based on an exponential function under climate forcing which can be effectively used to estimate the seasonal cell production for individual trees. It was shown that the model is able to simulate different cell production for fast-, middle- and slow-growing trees under …
Upper thermal threshold of Lepidurus arcticus (Branchiopoda, Notostraca) in lakes on the southern outreach of its distribution range
2021
Qvenild T, Fjeld E, Fjellheim A, Hammar J, Hesthagen T and Lakka H-K. 2021. Upper thermal threshold of Lepidurus arcticus (Branchiopoda, Notostraca) in lakes on the southern outreach of its distribution range. Fauna norvegica 41: 50–88. The Arctic tadpole shrimp Lepidurus arcticus has a circumpolar distribution and the Scandes (Fennoscandian Mountains) marks its southernmost limit in Europe. Within this area, 391 natural and 88 regulated lakes with L. arcticus have been identified, of which 87% are above the treeline. The lakes hosting L. arcticus decrease in altitude from south to north, which results from its temperature preferences. The majority of the locations are at a lower lake air t…
ANALISI DEI TREND DI INDICI CLIMATICI IN SICILIA
2008
Spatial and temporal variability of rainfall over the Republic of Djibouti from 1946 to 2017.
2021
20 pages; International audience; For the first time, the spatial and temporal variability of rainfall in the Republic of Djibouti is investigated using data from 14 weather stations over the period 1946–2017. Due to limited data availability, high-resolution long-term satellite rainfall products (CHIRPS, PERSIANN-CDR, TAMSATv3, ARC2) and ERA5 reanalysis also contribute to document time–space rainfall variability at monthly, seasonal and annual scales. Principal component analysis identifies two spatially coherent regions of rainfall variability in the east (coastal zone) and the west (inland zone) of the country. Annual rainfall amounts are everywhere very low (60–300 mm), but with contras…
In-depth characterization of denitrifier communities across different soil ecosystems in the tundra
2022
Abstract Background In contrast to earlier assumptions, there is now mounting evidence for the role of tundra soils as important sources of the greenhouse gas nitrous oxide (N2O). However, the microorganisms involved in the cycling of N2O in this system remain largely uncharacterized. Since tundra soils are variable sources and sinks of N2O, we aimed at investigating differences in community structure across different soil ecosystems in the tundra. Results We analysed 1.4 Tb of metagenomic data from soils in northern Finland covering a range of ecosystems from dry upland soils to water-logged fens and obtained 796 manually binned and curated metagenome-assembled genomes (MAGs). We then sear…
Ultra-High Energy Neutrinos at the Pierre Auger Observatory
2013
The observation of ultrahigh energy neutrinos (UHE nu s) has become a priority in experimental astroparticle physics. UHE nu s can be detected with a variety of techniques. In particular, neutrinos can interact in the atmosphere (downward-going nu) or in the Earth crust (Earth-skimming nu), producing air showers that can be observed with arrays of detectors at the ground. With the surface detector array of the Pierre Auger Observatory we can detect these types of cascades. The distinguishing signature for neutrino events is the presence of very inclined showers produced close to the ground (i.e., after having traversed a large amount of atmosphere). In this work we review the procedure and …