1,449 research outputs found
Mapping post-fire monthly erosion rates at the catchment scale using emphirical models implemented in GIS. A case study in Northern Italy
Mapping burn severity in the western Italian Alps through phenologically coherent reflectance composites derived from Sentinel-2 imagery
Hopelessness in Police Officers and Its Association with Depression and Burnout: A Pilot Study
Post-eruption morphological evolution and vegetation dynamics of the Blanco River, southern Chile
In this study, we analysed the morphological evolution of a channel segment in the Blanco River in southern Chile that was affected by the Chaitén Volcano eruption occurred in 2008–2009. Through a series of high-resolution satellite images from 2005 to 2019 that represents the entire pre- and post-eruptive dynamics and land covers, we tracked the geomorphological evolution of a 5.65-km-long river segment using channel form indices and also monitored the vegetation dynamics using object-based image analysis (OBIA). Discharge record for the Blanco River was also reconstructed to support the analysis of channel morphologic process. The study aims at examining whether a) the river channel is still adjusting 10 years after the eruption and if so, at what magnitude and, b) the recovered riparian vegetation plays a significant role in stabilising the river streambanks and terraces. We found that even 10 years after the eruption, the Blanco River channel planform is still adjusting, showing a simpler and stable channel configuration in the upstream reaches of the valley, where a certain degree of equilibrium appears to have been attained. More dynamic morphologies were observed in the reaches downstream that have to accommodate the arrival of large amounts of freshly eroded sediments. Our analysis showed that the occurrence of competent floods capable of reworking the river channel matches with the geomorphic indices and mark the post-eruption adjustments of the channel. Finally, the in-channel and riparian vegetation does not play a significant role in stabilising the active channel, streambanks, and terraces, reinforcing the recolonization of sedimentary active areas occurring elsewhere in the valley.This research was developed within the frame of the project FONDECYT 1170413 funded by the Chilean Government. Authors acknowledge the support of the Economy and Knowledge Department of the Catalan Government through the Fluvial Dynamics Research Group (RIUS) SGR017-459
Role of C in MgC_xNi_3 investigated from first principles
The influence of vacancies in the sub-lattice of , on its
structural, electronic and magnetic properties are studied by means of the
density-functional based Korringa-Kohn-Rostoker Green's function method
formulated in the atomic sphere approximation. Disorder is taken into account
by means of coherent-potential approximation. Characterizations representing
the change in the lattice properties include the variation in the equilibrium
lattice constants, bulk modulus and pressure derivative of the bulk modulus,
and that of electronic structure include the changes in the, total, partial and
-resolved density of states. The incipient magnetic properties are
studied by means of fixed-spin moment method of alloy theory, together in
conjunction with the phenomenological Ginzburg-Landau equation for magnetic
phase transition. The first-principles calculations reveal that due to the
breaking of the - bonds, some of the 3d states, which were lowered
in energy due to strong hybridization, are transfered back to higher energies
thereby increasing the itinerant character in the material. The Bloch spectral
densities evaluated at the high symmetry points however reveal that the charge
redistribution is not uniform over the cubic Brillouin zone, as new states are
seen to be created at the point, while a shift in the states on the
energy scale are seen at other high symmetry points
Legacy of wood charcoal production on subalpine forest structure and species composition
Land-use legacy on forest dynamics at both stand and landscape scale can last for centuries, affecting forest structure and species composition. We aimed to disentangle the history of the charcoal production legacies that historically shaped Mont Avic Natural Park (Aosta Valley, Italy) forests by integrating LiDAR, GIS, anthracological, and field data at the landscape scale. We adopted different geostatistical tools to relate geographic layers from various data sources. The overexploitation due to intensive charcoal production to fuel mining activities shaped the current forests by homogenising their structure and species composition into dense and young stands with a reduction in late seral species such as Norway spruce (Picea abies) and an increase in pioneer species such as Mountain pine (Pinus uncinata). The multidisciplinary and multi-scale framework adopted in this study stresses the role of historical landscape ecology in evaluating ecosystem resilience to past anthropogenic disturbances. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13280-022-01750-y
Identifying Organizational Stressors That Could Be a Source of Discomfort in Police Officers: A Thematic Review
The aim of this paper is to highlight the organizational factors that might influence perceived discomfort in police officers. The studies included in the thematic review referred to specific factors, not the general terms “organizational stressors” or “workplace stressors”. It is important to emphasize this distinction because most studies use the general term “organizational stressor” (referring to context) to distinguish from “operational stressor” (referring to content, such as exposure to danger, threat, and trauma). For our purposes, we selected the studies that examined specific organizational factors. The results indicate that organizational social support, organizational culture, leadership, and bureaucracy are the organizational factors associated with police officers’ perceived discomfort. These organizational factors could have negative impacts on individuals, perceptions of stigma when contacting support services, anxiety and depressive symptoms, burnout, PTSD, and suicidal thoughts, among others
Effects of twenty years of ungulate browsing on forest regeneration at Paneveggio Reserve, Italy
Forest ecosystems are threatened by different natural disturbances. Among them, the irruption of large herbivores represents one of the most alarming issues. Several local-scale studies have been carried out to clarify the mechanisms governing ungulate\u2013forest interactions, to understand the effect of wild ungulates overabundance, and to apply conservation plans. However, information at large scales, over long periods of observation and from unmanipulated conditions is still scarce. This study aims to improve our knowledge in this field by using repeated inventories to investigate: the types of damage produced by ungulate populations on young trees, the drivers that stimulate browsing activity and its consequences on the specific composition of seedlings and saplings. To reach these goals, we used data collected during a twenty-year monitoring program (1994\u20132014) in the forests of Paneveggio-Pale di San Martino Nature Park (Italy). We applied descriptive statistics to summarize the data, GLMs to identify the drivers of browsing activity and Non-Metric Multidimensional Scaling (nMDS) ordinations to investigate the changes in specific composition of young trees across 20 years. We detected increasing browsing activity from 1994 to 2008 and a decline in 2014. Ungulates browsed preferentially in mature stands, and fed mostly on seedlings and saplings under 150 cm of height. The analysis of the environmental drivers of browsing pressure on the smallest size classes of plants suggests that foraging behavior is influenced by snowpack conditions, ungulate density and seasonality. Moreover, results underline the fact that ungulates feed mostly on palatable species, especially European rowan, but can also use unpalatable plants as emergency food under high competition levels. nMDS results suggest that rowan seed dispersion might be promoted by deer movements, however, saplings of this species were not able to exceed 30 cm of height because of heavy browsing. This bottleneck effect led to the dominance of unpalatable species, mostly Norway spruce, reducing diversity during forest regeneration. If prolonged, this effect could lead to a reduction of tree species richness, with cascading effects on many parts of the ecosystem, and threatening the resilience of the forest to future disturbances
- …