91 research outputs found
The invasion history of Elodea canadensis and E. nuttallii (Hydrocharitaceae) in Italy from herbarium accessions, field records and historical literature
We analysed the invasion history of two North American macrophytes (Elodea canadensis and E. nuttallii) in Italy, through an accurate census of all available herbarium and field records, dating between 1850 and 2019, and a rich literature collection describing the initial introduction and naturalisation phase that supports the results obtained by the occurrence records. Elodea canadensis arrived in Italy before 1866 and had two invasion phases, between the 1890s and 1920s and between the 1990s and 2000s; E. nuttallii, probably arrived in the 1970s, started invading in 2000 and the invasion is still ongoing. Botanical gardens and fish farming played a crucial role in dispersal and naturalisation of both species. The current invasion range of both species is centred in northern Italy, with scattered occurrences of E. canadensis in central and southern regions. River Po represents a dispersal barrier to the Mediterranean region and a strategic monitoring site to prevent the invasion in the peninsula. The study detects differences in the niches of the two species during the introduction and naturalisation phase and a habitat switch occurred after 1980 in E. canadensis and after 2000 in E. nuttallii, during their expansion phases. For E. canadensis the switch corresponds to the second invasion round. Further research can clarify whether the second invasion round is due to confusion of the recently introduced E. nuttallii with E. canadensis, to a cryptic introduction of a new genotype, to post-introduction evolution, or just to an increased scientific interest in biological invasions
Invasion trends of aquatic Ludwigia hexapetala and L. peploides subsp. montevidensis (Onagraceae) in Italy based on herbarium records and global datasets
Identifying areas susceptible to invasion by an alien species is a strategy of prevention. We used national herbaria and global databases to assess the invasion trends of the two aquatic invasive species Ludwigia hexapetala and Ludwigia peploides subsp. montevidensis in Italy. We defined the invasion status with invasion curves and predicted potentially suitable areas with Species Distribution Models based on WorldClim variables and the human footprint index. Low seasonal variation in temperature and precipitation, temperature ≥ 20 °C in the driest period of the year and low precipitation in the coldest period are the bioclimatic factors that most account for the potential distribution of the two species. The human footprint has a lower relative importance than bioclimatic variables. All Italian peninsula appears as a suitable bioclimatic environment for the invasion of the two Ludwigia species, with over 90% of areas with high suitability lying below 600 m altitude. Only mountain regions and the islands appear less suitable. The agricultural land at the foothill of the Appennine in the Mediterranean region is the most vulnerable to the invasion. Considering the trend of the invasion curves, which have been sharply rising for the latest decades, there are reasons to expect that the alien Ludwigia species will continue their expansion, if no timely and effective actions are taken. Informative campaigns, accurate monitoring and prompt management are fundamental preventive tools in areas predicted as vulnerable to invasion by this study
Invasion trends of aquatic Ludwigia hexapetala and L. peploides subsp. montevidensis (Onagraceae) in Italy based on herbarium records and global datasets
Identifying areas susceptible to invasion by an alien species is a strategy of prevention. We used national herbaria and global databases to assess the invasion trends of the two aquatic invasive species Ludwigia hexapetala and Ludwigia peploides subsp. montevidensis in Italy. We defined the invasion status with invasion curves and predicted potentially suitable areas with Species Distribution Models based on WorldClim variables and the human footprint index. Low seasonal variation in temperature and precipitation, temperature ≥ 20 °C in the driest period of the year and low precipitation in the coldest period are the bioclimatic factors that most account for the potential distribution of the two species. The human footprint has a lower relative importance than bioclimatic variables. All Italian peninsula appears as a suitable
bioclimatic environment for the invasion of the two Ludwigia species, with over 90% of areas with high suitability lying below 600 m altitude. Only mountain regions and the islands appear less suitable. The agricultural land at the foothill of the Appennine in the Mediterranean region is the most vulnerable to the invasion. Considering the trend of the invasion curves, which have been sharply rising for the latest decades, there are reasons to expect that the alien Ludwigia species will continue their expansion, if no timely and effective actions are taken. Informative campaigns, accurate monitoring and prompt management are fundamental preventive tools in areas predicted as vulnerable to invasion by this study
Osteoclast Activated FoxP3+ CD8+ T-Cells Suppress Bone Resorption in vitro
BACKGROUND: Osteoclasts are the body's sole bone resorbing cells. Cytokines produced by pro-inflammatory effector T-cells (T(EFF)) increase bone resorption by osteoclasts. Prolonged exposure to the T(EFF) produced cytokines leads to bone erosion diseases such as osteoporosis and rheumatoid arthritis. The crosstalk between T-cells and osteoclasts has been termed osteoimmunology. We have previously shown that under non-inflammatory conditions, murine osteoclasts can recruit naĂŻve CD8 T-cells and activate these T-cells to induce CD25 and FoxP3 (Tc(REG)). The activation of CD8 T-cells by osteoclasts also induced the cytokines IL-2, IL-6, IL-10 and IFN-Îł. Individually, these cytokines can activate or suppress osteoclast resorption. PRINCIPAL FINDINGS: To determine the net effect of Tc(REG) on osteoclast activity we used a number of in vitro assays. We found that Tc(REG) can potently and directly suppress bone resorption by osteoclasts. Tc(REG) could suppress osteoclast differentiation and resorption by mature osteoclasts, but did not affect their survival. Additionally, we showed that Tc(REG) suppress cytoskeletal reorganization in mature osteoclasts. Whereas induction of Tc(REG) by osteoclasts is antigen-dependent, suppression of osteoclasts by Tc(REG) does not require antigen or re-stimulation. We demonstrated that antibody blockade of IL-6, IL-10 or IFN-Îł relieved suppression. The suppression did not require direct contact between the Tc(REG) and osteoclasts. SIGNIFICANCE: We have determined that osteoclast-induced Tc(REG) can suppress osteoclast activity, forming a negative feedback system. As the CD8 T-cells are activated in the absence of inflammatory signals, these observations suggest that this regulatory loop may play a role in regulating skeletal homeostasis. Our results provide the first documentation of suppression of osteoclast activity by CD8 regulatory T-cells and thus, extend the purview of osteoimmunology
Natural stones used in a Royal House of Piedmont (Italy)
Villa della Regina", built at the beginning of the 17th century, on the hill of Turin (Italy), is the last example of a "Vigna" residence with Italian gardens, palace, woods and vineyard. Gardens, park, and palace were enlarged and modified many times in the following centuries and suffered reparations, damages and substitution. From 1994 the "Villa" is in charge of the "Soprintendenza per il Patrimonio Storico e Artistico di Torino" who is carrying on the restoration. The works gave a chance to analyze the stone materials, to assess the present state of the manufacts, to locate the extraction sites, and to reconstruct the historical stages of the building and repair works. The authors provide a description of the stones employed in the different parts through a petrographic characterization, of the observed decay, of the identified quarry sites, and an evaluation of the results of the conservative intervention. Stones employed in the "Villa della Regina" represent a catalog of the ancient fine marbles and decorative limestones of Piedmont, most of them no longer exploited. In the conclusions a sinthetic account is given of the inter-relation between architectural development and local marble industry in the 17th-18th centur
Natural stones used in a Royal House of Piedmont (Italy).
Villa della Regina”, built at the beginning of the 17th century, on the hill of Turin (Italy), is the last example of a “Vigna” residence with Italian gardens, palace, woods and vineyard. Gardens, park, and palace were enlarged and modified many times in the following centuries and suffered reparations, damages and substitution. From 1994 the “Villa” is in charge of the “Soprintendenza per il Patrimonio Storico e Artistico di Torino” who is carrying on the restoration. The works gave a chance to analyze the stone materials, to assess the present state of the manufacts, to locate the extraction sites, and to reconstruct the historical stages of the building and repair works. The authors provide a description of the stones employed in the different parts through a petrographic characterization, of the observed decay, of the identified quarry sites, and an evaluation of the results of the conservative intervention. Stones employed in the “Villa della Regina” represent a catalog of the ancient fine marbles and decorative limestones of Piedmont, most of them no longer exploited. In the conclusions a sinthetic account is given of the inter-relation between architectural development and local marble industry in the 17th-18th centur
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