1,109 research outputs found
Seed germination report for Limonium merxmuelleri subsp. merxmuelleri (Plumbaginaceae)
The present report illustrates the first germination data of Limonium merxmuelleri subsp. merxmuelleri, a pioneer species of mine waste materials of Iglesiente region (South-West Sardinia). After harvesting, seeds were subjected to germination tests at the Sardinian Germplasm Bank (BG-SAR). The results show a high germination capability and germination rate at each tested temperature, with a slight germination reduction at the highest temperature (25°C) that simulates the aridity of the summer period
The vascular flora of the Marine Protected Area of "Capo Carbonara" (SE-Sardinia)
This study aims at presenting an updated inventory of the vascular flora of the Capo Carbonara Marine Protected Area, including the Sites of Community Importance “Isola dei Cavoli, Serpentara, Punta Molentis e Campulongu” and partially of “Costa di Cagliari”, in Sardinia (Italy). A total of 653 taxa are reported, 84% of which are native (5% endemics) and 16% non-native (10%
neophytes, 6% archaeophytes). The native component includes 406 species, 135 subspecies, two variety and one hybrid, belonging to 75 families and 313 genera. The non-native taxa are 94 species, 13 subspecies, one variety and one hybrid, belonging to 40 families and 81 genera. Life-form analysis of native species revealed a prevalence of therophytes (49%) followed by hemicryptophytes (21%), geophytes (14%) and chamaephytes (7%). Therophytes (33%) fol lowed by phanerophytes (32%) are prevalent among the non-native taxa. Biogeographically,
among native species, the Mediterranean element is largely prevailing (81%), mainly consisting of Circum-Mediterranean (39%) and Euro-Mediterranean (27%) taxa, while the American ele ment (35%) prevails over the Mediterranean species (29%) among the non-native taxa. Among endemics, the Sardo-Corsican taxa are dominant (55%), followed by Sardo-Corsican-Tuscan Archipelago (14%) and Sardinian (10%) taxa
Using Mediterranean Native Plants for the Phytoremediation of Mining Sites: An Overview of the Past and Present, and Perspectives for the Future
Mining exploitation in the Mediterranean Basin has left evident scars on the environment, and poses serious risks for human health and biodiversity, especially when mine wastes are left abandoned. This review analysed the main issues of metal(loid)s pollution related to mine exploitation in the Mediterranean Basin. Here, a list of Mediterranean native plant species studied for phytoremediation is given and, considering their biological forms, vegetational types, and ecology, we categorised them into halotolerant and hydro/hygrophilous vegetation, annual and perennial meadows, garrigues and maquis, and high maquis and woods. The main conclusions of the review are as follows: (1) plant communities established on mine environments are often rich in endemic taxa which ensure a high biodiversity and landscape value, and can help in the psychophysical health of local inhabitants; (2) political and land management should take greater account of the use of native plants for the remediation of contaminated soils; (3) a multidisciplinary approach that includes, among others, studies on biochemical response to metal(loid)s as well as the application of innovative soil amendments gives better results; (4) phytoextraction applications require a detailed recovery plan that takes into consideration several issues, including the negative influence on biodiversity due to extensive use of monotypic plantations, disposal of harvested hazardous plants, and the risk of phytoextracts entering the food chain; and (5) more studies are necessary to increase knowledge and to detect suitable species—especially halophytic ones—for phytoremediation purposes
Neutropenia as an adverse event following vaccination : results from randomized clinical trials in healthy adults and systematic review
Background : In the context of early vaccine trials aimed at evaluating the safety profile of novel vaccines, abnormal haematological values, such as neutropenia, are often reported. It is therefore important to evaluate how these trials should be planned not to miss potentially important safety signals, but also to understand the implications and the clinical relevance.
Methodology : We report and discuss the results from five clinical trials (two with a new Shigella vaccine in the early stage of clinical development and three with licensed vaccines) where the absolute neutrophil counts (ANC) were evaluated before and after vaccination. Additionally, we have performed a systematic review of the literature on cases of neutropenia reported during vaccine trials to discuss our results in a more general context.
Principal Findings : Both in our clinical trials and in the literature review, several cases of neutropenia have been reported, in the first two weeks after vaccination. However, neutropenia was generally transient and had a benign clinical outcome, after vaccination with either multiple novel candidates or well-known licensed vaccines. Additionally, the vaccine recipients with neutropenia frequently had lower baseline ANC than non-neutropenic vaccinees. In many instances neutropenia occurred in subjects of African descent, known to have lower ANC compared to western populations.
Conclusions : It is important to include ANC and other haematological tests in early vaccine trials to identify potential safety signals. Post-vaccination neutropenia is not uncommon, generally transient and clinically benign, but many vaccine trials do not have a sampling schedule that allows its detection. Given ethnic variability in the level of circulating neutrophils, normal ranges taking into account ethnicity should be used for determination of trial inclusion/exclusion criteria and classification of neutropenia related adverse events
A blockchain-based distributed paradigm to secure localization services
In recent decades, modern societies are experiencing an increasing adoption of interconnected smart devices. This revolution involves not only canonical devices such as smartphones and tablets, but also simple objects like light bulbs. Named the Internet of Things (IoT), this ever-growing scenario offers enormous opportunities in many areas of modern society, especially if joined by other emerging technologies such as, for example, the blockchain. Indeed, the latter allows users to certify transactions publicly, without relying on central authorities or intermediaries. This work aims to exploit the scenario above by proposing a novel blockchain-based distributed paradigm to secure localization services, here named the Internet of Entities (IoE). It represents a mechanism for the reliable localization of people and things, and it exploits the increasing number of existing wireless devices and blockchain-based distributed ledger technologies. Moreover, unlike most of the canonical localization approaches, it is strongly oriented towards the protection of the users’ privacy. Finally, its implementation requires minimal efforts since it employs the existing infrastructures and devices, thus giving life to a new and wide data environment, exploitable in many domains, such as e-health, smart cities, and smart mobility
Explainable Machine Learning Exploiting News and Domain-Specific Lexicon for Stock Market Forecasting
In this manuscript, we propose a Machine Learning approach to tackle a binary classification problem whose goal is to predict the magnitude (high or low) of future stock price variations for individual companies of the SP 500 index. Sets of lexicons are generated from globally published articles with the goal of identifying the most impactful words on the market in a specific time interval and within a certain business sector. A feature engineering process is then performed out of the generated lexicons, and the obtained features are fed to a Decision Tree classifier. The predicted label (high or low) represents the underlying company's stock price variation on the next day, being either higher or lower than a certain threshold. The performance evaluation we have carried out through a walk-forward strategy, and against a set of solid baselines, shows that our approach clearly outperforms the competitors. Moreover, the devised Artificial Intelligence (AI) approach is explainable, in the sense that we analyze the white-box behind the classifier and provide a set of explanations on the obtained results
From mining wastes to mineral sources - investigating the REE-bearing occurrences in the Arburèse District (SW Sardinia)
In recent years, the search for possible sources of REE minerals in Europe involved numerous old mine
areas with high volumes of mining wastes that may offer significant amounts of Critical Raw Materials
(CRMs). In some cases, strong evidence of CRMs anomalous concentrations arises from environmental
characterization of wastes, so that an interesting problem is that of finding their sources, i.e., the original
CRMs - rich mineral phases in the residual ore. An excellent example is provided by the Arburèse district of
SW Sardinia, for about 150 years a major Pb-Zn source in Italy, now an area under study for remediation of
its severe environmental problems, including >10 Mt of waste deposits. The district exploited a large system
(>10 km) of low-temperature polymetallic veins hosted in Lower Paleozoic siliciclastic rocks belonging to
the Variscan Nappe zone, arranged in two main geometrical trends relative to the late Variscan Arbus pluton:
“peripheral” and “intersecting”. Recent investigations in the Montevecchio mine area discovered high Zn (up
to 2.65 wt.%) and Pb (1.23 wt.%) grades in stratified tailing materials belonging to the Sanna old processing
plant. Remarkably, ICP-MS analyses on the same materials revealed total REE+ Y contents attaining about
600 ppm. XRD studies confirmed a tailing composition essentially made of gangue minerals (quartz, siderite
and micas) with goethite, baryte and traces of Zn carbonates and Pb sulfates. Chondrite-normalized REE
patterns are coherent with the hydrothermal character of the source: however, both the REE mineralogical
host(s) in tailings and in the Montevecchio ore are still undetermined. In the search of REE-bearing phases
in the ores, some relevant insights are provided by studies on the southern branch of the Arburèse system,
where the veins of “peripheral” system are hosted in late Ordovician-Silurian sedimentary sequences. In this
part of the district the polymetallic veins assume the character of five-elements (Ni-Co-As-Bi-Ag) veins,
with a rich Ni-Co-Fe arsenide – quartz association (1) overprinted by a Zn-Pb-Cu sulfide – siderite – quartz
association (2), very similar to that dominating in Montevecchio. Investigations in the Pira Inferida mine
sector highlighted the presence of LREE fluorocarbonates (synchysite-Ce and bastnaesite-Ce) and phosphates
(monazite) associated with rutile and apatite. LREE minerals have been detected by SEM-EDS as tiny crystals
in the quartz-sericitic gangue of the Montevecchio-type (2) mineral association. The same minerals are found
in millimetric aggregates in the oxide zone of the veins, sporadically reported by mineral collectors in other
mine sites of the same system. Overall, these occurrences, similar to those found in other low-temperature vein
systems of Sardinia (e.g., Silius vein system), appear reliable mineral REE sources for Montevecchio mine
wastes; they may be therefore used as proxies for REE exploration and assessment in the district
Effect of storage conditions on seed germination of eigTyrrhenian endemic vascular plant species of conservation interest
The conservation of endemic and endangered plant species is of great interest to the scientific and research community. In this frame, seed banks play a crucial role when biodiversity preservation and climate change are considered. The study of seed viability and germination during storage conditions provides basic and useful information to ensure successful ex situ conservation. The aim of this study was to evaluate whether storage time and conditions (i.e., base collection at -25°C and active collection at +5°C) affect seed germination in the long term. For these purposes, eight Tyrrhenian endemic vascular plant species (mostly endangered) with orthodox seeds were studied: Brassica insularis, Centranthus amazonum, Dianthus morisianus, Digitalis purpurea var. gyspergerae, Ferula arrigonii, Helicodiceros muscivorus, Iberis integerrima and Verbascum plantagineum. These species were stored in the Sardinian Germplasm Bank (BG-SAR) at -25°C and at +5°C for a time ranging from 2 to 12 years. Germination tests were carried out following the optimal conditions reported in the literature for each species. The results showed, in general terms, the high seed germination capacity of all species stored at both conditions; regarding the time of seed storage, germination in some tested species (such as B. insularis and C. amazonum) slightly decreased over time. We argued that seed dehydration, low seed moisture content during storage and the use of hermetic glass containers can be considered key factors for long-term conservation of these orthodox seeds. In conclusion, this study showed that the conservation of these endemic species is ensured by seed bank storage, according to the general assumption that seed longevity depends on seed lot quality, on well-sealed storage containers and conditions before and during storage
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