405 research outputs found
Marine litter and psammophytes: a case study in the Migliarino-San Rossore-Massaciuccoli Regional Park coastal sand dunes
Coastal sand dunes are one of the most impacted ecosystems in the world (1). They host various habitats of Community interest under the Habitats Directive 92/43/EEC but are profoundly affected by pollution and waste management, even within protected areas. The factors that define the amount, type and distribution of
beach litter are complex and relate more to human intervention and natural variables.
This work aims to analyse the composition, abundance and distribution of marine litter within a protected area in two different chronological windows, i.e. before and after the bathing season. We also attempted to verify whether the presence of waste could alter the coverage of the psammophilous vegetation.
The protected area examined in this project is the Migliarino-San Rossore-Massaciuccoli Regional Park (Tuscany, Italy), where we selected three dune sites stretching along the coastline with a North/South gradient: Lecciona (2 Km2), Bufalina (1 Km2) and Calambrone (1 Km2), respectively. We adopted a stratified random sampling design, using permanent multiscale squared-plots of 16 m2, with two nested plots placed at a fixed corner of 4 m2 and 1 m2, respectively. Each site was divided into same-area strata with a spatially optimised algorithm. Inside each layer two points were randomly selected, corresponding to the field plots; overall, a total of 22 plots were sampled. Sampling took place in two sessions, one in May and the other one in November.
The data collected were the total percentage coverage of litter and the individual coverage of each type of litter for each plot. Classification of marine litter followed the directives of the "Master List of Categories of Litter Items", a list drawn up by the Joint Research Centre (JRC) of the European Commission based on
several classification protocols (2). At the same time, we censused the plant species in each plot and measured their total percentage coverage at each investigated spatial scale.
We compiled a litter × plot matrix with the percentage of coverage of each type of waste found in the plots at the three spatial scales and in the two periods. The PERMANOVA analysis of the matrix with 4 factors (month, site, layer and plot area) highlighted that the interaction term month × site explained significantly (P< 0.001) the variance in the composition of waste at the plot level. NMDS analysis (non-metric multidimensional scaling) showed that the categories most significantly related to the variability between plots were the following: "plastic fragments less than 2.5 cm (G78)" and "plastic fragments between 2.5 and 50 cm (G79)". These two types of litter showed contrasting patterns over time: G78 increased from June to November, G79 decreased in the same period. Multivariate analyses were carried out using the software PRIMER v.7 (3) and PERMANOVA+ (4).
The diachronic study of the relationship between area and the number of litter categories, carried out using the Arrhenius power law equation (5), showed that in Lecciona and Bufalina there was in November a greater growth in types of litter as the area increased in respect to the first sampling period, while in Calambrone there were no differences. According to Pearson correlation test, temporal turnover of litter categories, quantified partitioning β-diversity following (6), and the total percentage coverage of vegetation resulted inversely correlated (cor = - 0.44, P = 0.038).
In conclusion, artificial polymer materials were found to be the dominant waste type (85%) at the three study sites examined, two of which were characterised by an increase in waste after the bathing season. In the third site, however, probably due to regular manual cleaning actions, no differences were found. Where vegetation
is more abundant, the total number of litter categories tends to be more stable across the seasons, suggesting that psammophytes are a relevant biotic component to be considered in the analysis of spatio-temporal dynamics of coastal litter.
1) Ciccarelli D., 2014. Environ. Manag. 54, 194–204
2) Galgani F., Hanke G., Werner S., et al. (2013) JRC Scientific and Policy reports
3) Clarke K., Warwick R. (2001). Change in marine communities: an approach to statistical analysis and interpretation
Ed. 2. PRIMER-E, Plymouth
4) Anderson M.J., Gorley R.N., Clarke R.K. (2008). PERMANOVA+ for PRIMER: Guide to software and statistical
methods. PRIMER-E, Plymouth
5) Arrhenius O. (1921) J Ecol, 9, 95-99
6) Baselga A. (2010). Glob Ecol Biogeogr, 19, 134-14
Mapping of Yucca gloriosa invasion along Mediterranean coastal dunes using unmanned aerial vehicles (UAVs)
Invasive Alien Plants (IAPs) are defined as those species whose introduction and/or spread outside their natural distribution can threaten the biological diversity of an ecosystem. They represent a severe threat to biodiversity and can severely alter the performance of crucial ecosystems such as coastal dunes. Coastal dunes are composed of specialized fauna and flora, converting them into strategic ecosystems due to their unique ecological functions.
Coastal dunes are one of the most invaded European environments, with a total flora composed of up to 7% of IAPs. One of these IAPs is Yucca gloriosa L. (Asparagaceae), a homoploid hybrid native plant from the United States of America introduced to Europe for ornamental purposes. For Italy, Y. gloriosa is a typical invasive species related to fixed dunes dominated by Juniperus sp. pl. (with which it competes).
Concerning biological invasions, maybe the most effective management strategy is early detection and mapping. In that sense, this work explores and tests the potential of unmanned aerial vehicles (UAVs) for detecting, mapping, and managing the Y. gloriosa invasion along the Mediterranean coastal dunes of a protected area located in Tuscany (Italy).
In detail, this work focuses on four aspects: i) determine the suitability of RGB images to map Y. gloriosa, ii) identify the best time of data acquisition, iii) detect changes affecting the occurrence and cover of Y. gloriosa, and iv) propose a set of management actions to preserve a coastal dune ecosystem subjected to plant invasion.
The UAV images allowed the generation of ultra-high spatial resolution maps to assess the Y. gloriosa invasion and distribution along the surveyed sandy dunes. The morphological characteristics of this plant – especially at the foliar level – make the invasion of Y. gloriosa particularly suitable for being evaluated and managed using UAV mapping, especially in coastal dunes vegetation that can be a mosaic of different plant communities hard to identify when airborne or satellite images are used.
According to the obtained results, the spring season is the perfect time to collect data because light conditions are ideal, with minimal shading effects. Also, due to the peculiar morphology of Y. gloriosa leaves, the timing of data collection seems not crucial for mapping this IAP on coastal dune habitats.
Despite the massive eradication action funded by a LIFE project during the period 2005-2009, Y. gloriosa is still present in the protected area and affects the priority habitat of juniper. This might be linked to the fact that Y. gloriosa is a perennial rhizomatous shrub capable of switching its photosynthesis from the C3 to CAM pathway and, therefore, withstand the harsh environmental conditions of dune ecosystems.
The early detection using UAVs is the first line of defense against IAPs colonization over any ecosystem. From a conservation and management point of view, this work suggests the development of annual biomonitoring of Y. gloriosa to check its distribution over time and control its spread where it becomes particularly invasive. In this case, one possible strategy will be to keep the IAP in isolated nuclei of plants that are easier to remove with mechanical methods. In a broader view, the study area and the Mediterranean coast must include the ban on introducing non-native species as a strategy, adopting a short-term non-native Management Plan as urgent action
Reoperação de tromboendarterectomia pulmonar em recidiva de tromboembolismo pulmonar crônico hipertensivo
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Search for lepton-flavour-violating decays of Higgs-like bosons.
A search is presented for a Higgs-like boson with mass in the range 45 to 195 GeV/c2 decaying into a muon and a tau lepton. The dataset consists of proton-proton interactions at a centre-of-mass energy of 8 TeV , collected by the LHCb experiment, corresponding to an integrated luminosity of 2 fb-1 . The tau leptons are reconstructed in both leptonic and hadronic decay channels. An upper limit on the production cross-section multiplied by the branching fraction at 95% confidence level is set and ranges from 22 pb for a boson mass of 45 GeV/c2 to 4 pb for a mass of 195 GeV/c2
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Search for the rare decay D0→μ+μ-
A search for the rare decay D →μ μ is performed using a data sample, corresponding to an integrated luminosity of 0.9fb , of pp collisions collected at a centre-of-mass energy of 7 TeV by the LHCb experiment. The observed number of events is consistent with the background expectations and corresponds to an upper limit of B(D0→μ+μ-)<6.2(7.6)×10-9 at 90% (95%) confidence level. This result represents an improvement of more than a factor twenty with respect to previous measurements. © 2013 CERN. 0 + - -
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Search for Bc+ decays to two charm mesons
A search for decays of B c + mesons to two charm mesons is performed for the first time using data corresponding to an integrated luminosity of 3.0fb −1 , collected by the LHCb experiment in pp collisions at centre-of-mass energies of 7 and 8 TeV. The decays considered are B c + →D (s) (⁎)+ D‾ (⁎)0 and B c + →D (s) (⁎)+ D (⁎)0 , which are normalised to high-yield B + →D (s) + D‾ 0 decays. No evidence for a signal is found and limits are set on twelve B c + decay modes
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Measurements of CP asymmetries in charmless four-body Λb0 and Ξb0 decays
Abstract: A search for CP violation in charmless four-body decays of Λb0 and Ξb0 baryons with a proton and three charged mesons in the final state is performed. To cancel out production and detection charge-asymmetry effects, the search is carried out by measuring the difference between the CP asymmetries in a charmless decay and in a decay with an intermediate charmed baryon with the same particles in the final state. The data sample used was recorded in 2011 and 2012 with the LHCb detector and corresponds to an integrated luminosity of 3fb-1. A total of 18 CP asymmetries are considered, either accounting for the full phase space of the decays or exploring specific regions of the decay kinematics. No significant CP-violation effect is observed in any of the measurements
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Measurement of CP observables in the process B <sup>0</sup> → DK <sup>*0</sup> with two- and four-body D decays
Measurements of observables in decays are presented,
where represents a superposition of and states. The
meson is reconstructed in the two-body final states , ,
and , and, for the first time, in the four-body final
states , and .
The analysis uses a sample of neutral mesons produced in proton-proton
collisions, corresponding to an integrated luminosity of 1.0, 2.0 and 1.8 collected with the LHCb detector at centre-of-mass energies of
7, 8 and 13 TeV, respectively. First observations of the decays
and are
obtained. The measured observables are interpreted in terms of the
-violating weak phase
Transcriptional responses of winter barley to cold indicate nucleosome remodelling as a specific feature of crown tissues
We report a series of microarray-based comparisons of gene expression in the leaf and crown of the winter barley cultivar Luxor, following the exposure of young plants to various periods of low (above and below zero) temperatures. A transcriptomic analysis identified genes which were either expressed in both the leaf and crown, or specifically in one or the other. Among the former were genes responsible for calcium and abscisic acid signalling, polyamine synthesis, late embryogenesis abundant proteins and dehydrins. In the crown, the key organ for cereal overwintering, cold treatment induced transient changes in the transcription of nucleosome assembly genes, and especially H2A and HTA11, which have been implicated in cold sensing in Arabidopsis thaliana. In the leaf, various heat-shock proteins were induced. Differences in expression pattern between the crown and leaf were frequent for genes involved in certain pathways responsible for osmolyte production (sucrose and starch, raffinose, γ-aminobutyric acid metabolism), sugar signalling (trehalose metabolism) and secondary metabolism (lignin synthesis). The action of proteins with antifreeze activity, which were markedly induced during hardening, was demonstrated by a depression in the ice nucleation temperature
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