Search results for "conservation"
showing 10 items of 2328 documents
Flora italiana di interesse comunitario: risultati del IV Report e Piano nazionale di monitoraggio
2020
An overestimated relationship? Violent political unrest and tourism foreign direct investment in the Middle East
2010
Although the tourism industry is increasingly globalising, empirical research on the accompanying foreign direct investment (FDI) is surprisingly lacking. Furthermore, the nexus of political risk, violent political unrest and tourism FDI has been relatively neglected. Using Egypt as a heuristic case study and adopting a qualitative methodology, this paper explores the question of how political risk and violent political unrest influence tourism FDI. Surprisingly, the results are not able to corroborate a clear relationship between the two. In contrast, these results indicate that the role of stability and security for tourism FDI in developing countries has largely been overestimated in the…
Emission standards versus immission standards for assessing the impact of urban drainage on ephemeral receiving water bodies
2010
In the past, emission standard indicators have been adopted by environmental regulation authorities in order to preserve the quality of a receiving water body. Such indicators are based on the frequency or magnitude of a polluted discharge that may be continuous or intermittent. In order to properly maintain the quality of receiving waters, the Water Framework Directive, following the basic ideas of British Urban Pollution Manual, has been established. The Directive has overtaken the emission-standard concept, substituting it with the stream-standard concept that fixes discharge limits for each polluting substance depending on the self-depurative characteristics of receiving waters. Stream-…
Ecological and human health risks appraisal of metal(loid)s in agricultural soils: a review
2019
Agriculture is one of the major human activities that changed the landforms, water resources and the biogeochemical cycles. Pollution of agricultural soilsby metal(loid)s is a serious and global hazard but worldwide studies related to metal(loid)s pollution in agricultural soils are very limited. To fulfil this gap, metal(loid)s content in agricultural soils from 2001 to 2019 all over the world was reviewed. Multivariate statistical techniques, contamination indices and human health risk assessment were determined for the metal(loid)s. Among the analysed metal(loid)s, the average contents of Zn, Cu, Pb, Cr, Cd, As and Ni exceeded the Canadian, and China soil guidelines limits. The results o…
Impact of Plastic Debris on the Gut Microbiota of Caretta caretta From Northwestern Adriatic Sea
2021
Plastic pollution is nowadays a relevant threat for the ecological balance in marine ecosystems. Small plastic debris (PD) can enter food webs through various marine organisms, with possible consequences on their physiology and health. The loggerhead sea turtle (Caretta caretta), widespread across the whole Mediterranean Sea, is a “flagship species,” useful as indicator of the general pollution level of marine ecosystems. Ingested PD accumulate in the final section of turtles’ digestive tract before excretion. During their transit and accumulation, PD also interact with the residing microbial community, with possible feedback consequences on the host’s health. To explore the possible relati…
Maiolica bricks spires and domes in Sicily.Tipology, constructive and decorative elements
2018
The use of maiolica bricks as artefact for surface decoration is widespread both in monumental and ordinary architectures in the Mediterranean regions, harmonizing the local construction traditions with the Islamic influences. This study presents an in-depth analysis of examples of spires and domes in Sicily featuring earthenware maiolica cladding serving both as decoration and structural element. Due to the limited knowledge of these artefacts, incautious construction operations led to an alteration of their material and technical features, putting at risk a centuries-old heritage. The systematic investigation on more than a hundred samples categorises these architectural polychrome elemen…
Wedge-shaped bricks spires and domes. Construction and decorative aspects
2018
The use of maiolica bricks as artefact for surface decoration is widespread both in monumental and ordinary architectures in the Mediterranean regions, harmonizing the local construction traditions with the Islamic influences. This study presents an in-depth analysis of examples of spires and domes in Sicily featuring earthenware maiolica cladding serving both as decoration and structural element. Due to the limited knowledge of these artefacts, incautious construction operations led to an alteration of their material and technical features, putting at risk a centuries-old heritage. The systematic investigation on more than a hundred samples categorises these architectural polychrome elemen…
AN HYPERBOLIC-PARABOLIC PREDATOR-PREY MODEL INVOLVING A VOLE POPULATION STRUCTURED IN AGE
2020
Abstract We prove existence and stability of entropy solutions for a predator-prey system consisting of an hyperbolic equation for predators and a parabolic-hyperbolic equation for preys. The preys' equation, which represents the evolution of a population of voles as in [2] , depends on time, t, age, a, and on a 2-dimensional space variable x, and it is supplemented by a nonlocal boundary condition at a = 0 . The drift term in the predators' equation depends nonlocally on the density of preys and the two equations are also coupled via classical source terms of Lotka-Volterra type, as in [4] . We establish existence of solutions by applying the vanishing viscosity method, and we prove stabil…
The genetic legacy of extreme exploitation in a polar vertebrate
2020
Understanding the effects of human exploitation on the genetic composition of wild populations is important for predicting species persistence and adaptive potential. We therefore investigated the genetic legacy of large-scale commercial harvesting by reconstructing, on a global scale, the recent demographic history of the Antarctic fur seal (Arctocephalus gazella), a species that was hunted to the brink of extinction by 18th and 19th century sealers. Molecular genetic data from over 2,000 individuals sampled from all eight major breeding locations across the species’ circumpolar geographic distribution, show that at least four relict populations around Antarctica survived commercial huntin…
Dynamic Animal Populations in Managed Forests: Species Ecological Requirements and Sustainable Harvesting
2015
Forest management has altered forested environments and provoked stress to many natural habitats and biodiversity. The goal of biodiversity management is the long-term persistence of populations in human-modified environments. We demonstrate a spatio-temporal modeling approach to address the relationship between various management objectives and population persistence in the long-term in a commercial forest landscape. We used the flying squirrel (Pteromys volans), the three-toed woodpecker (Picoides tridactylus) and the long-tailed tit (Aegithalos caudatus) as example species. They are all forest species but they have distinctly different habitat requirements. In the model, forest growth, f…