1,720,996 research outputs found
Valutazione dello stato di conservazione dei popolamenti a Cystoseira nell’AMP Capo Gallo-Isola delle Femmine (PA): osservazioni preliminari
No full textNon-Indigenous Species (NIS) within Marine Protected Areas (MPAs). The case study of the Aegadian Islands MPA (Sicily, Tyrrhenian Sea) and the Dwejra MPA (Maltese Islands, Ionian Sea)
No full textThe introduction of non-indigenous species (NIS) has been pointed out as a major threat to biodiversity. NIS may become invasive alien species (IAS) and may cause biodiversity loss and ecosystem service changes. In the Mediterranean Sea, Sicily and surrounding islands, also including a high number of Marine Protected Area (MPAs), as a consequence of their geographic position and the intense maritime traffic, is a region particularly vulnerable and prone to NIS invasions. Since frontiers do not exist in the sea, biological invasions may severely affect MPAs, whose major aim is biodiversity conservation.
Among the Sicilian MPAs, the Aegadian Islands MPA report the highest number of NIS (19). Maritime traffic has certainly spearheaded the introduction and spread of these NIS. The presence of Caulerpa cylindracea in all the Sicilian MPAs, confirms the invasiveness of this species. Within the Aegadian Islands MPA anchoring is the main vector for the spread of this NIS, which has affected algal diversity but also favoured the establishment of other NIS namely the sabellid Branchiomma bairdi. Within the Dwejra MPA (Maltese Islands), anchoring has favoured the colonization by a number of vegetal NIS, namely the phanerogam Halophila stipulacea and the alga Caulerpa taxifolia var. distichophylla, mainly by creating clearances within the previously continuous Posidonia oceanica meadow. The high presence of NIS in MPAs confirms that they are not immune to NIS invasions. The expansion of NIS by recreational vessels represents a risk for MPAs, which are popular touristic destinations. The dissemination of good practices may stop new introductions, therefore enhancing biodiversity conservation. The creation of permanent observatories and alarm systems involving Sicilian and Maltese MPAs, able to early detect new introductions and to follow the spread of species already present might be an effective tool in the management of present and future introductions of NIS in MPAs
Vulnerability of algae and seagrasses to climate change
No full textBiodiversity is undergoing rapid and worrying changes, partially driven by anthropogenic activities. Human impacts and climate change (e.g. increasing temperature and ocean acidification) represent the most serious threats to biodiversity and ecosystem functioning.
Aim of this study was to assess, analysing the scientific literature and published data, how climate change can affect algae and seagrasses, evaluating their vulnerability and the possibility to use these organisms as indicators. Algae and seagrasses have a central role for several important ecological processes in aquatic ecosystems, and their loss can lead repercussions for the ecological function. Climate stressors affected acquatic vegetation, acting both in isolation and in combination with local perturbations (e.g. nutrient enrichment), reducing the resilience of marine communities. Ocean acidification has negative effects on calcification rates of calcareous algae; sea warming affects both the stability of Posidonia oceanica meadows and their potential recolonization. Considering future climate scenario researchers and policy makers have to plan measures to preserve biodiversity and the status of health of the marine ecosystems
LA MICROSCOPIA ELETTRONICA (SEM, CLSM) PER L’ANALISI DI MICROSISTEMI BIOLOGICI CHE COLONIZZANO I BENI CULTURALI
No full textRIASSUNTO - Il degrado dei materiali con cui sono realizzate le opere d’arte, è spesso causato dall’attività di macro e micro organismi (piante, insetti, licheni, alghe, batteri, attinomiceti etc.), denominati biodeteriogeni. Presenti in tutti gli habitat terrestri, costituiscono un serio problema per la conservazione sia in siti outdoor sia confinati, come biblioteche, archivi, istituti mussali, depositi e, comunque, in tutti quei luoghi dove si attua la conservazione/fruizione dei manufatti. In genere, non vi è luogo di conservazione che non mostri tracce di parziali o estese infestazioni/colonizzazioni che comportano alterazioni più o meno consistenti dei manufatti presenti. Le alterazioni di origine biologica si manifestano con fenomenologie abbastanza diverse in relazione agli organismi, ai parametri ambientali, alle caratteristiche dei materiali costitutivi del manufatto. I biodeteriogeni possono causare danni di tipo chimico (correlato all’effetto dei prodotti metabolici), fisico (legato alla penetrazione di cellule microbiche o di parti strutturali) ed estetico (patine, biofilm).
Pertanto, è di fondamentale importanza stabilire la presenza di macro-microrganismi e conseguentemente caratterizzarli, al fine di intervenire in modo tempestivo ed efficace limitando i danni, prima che diventino irreversibili. In tale ambito, la microscopia elettronica, sia a scansione (SEM) che a scansione laser confocale (CLSM), rappresenta uno strumento di indagine scientifica di estremo interesse.
ABSTRACT - Works of art are made of such materials that are often subjected to deterioration by macro and micro organisms (plants, insects, lichens, algae, bacteria, actinomycetes, etc..) called biodeteriogens. They are present in all terrestrial habitats, they therefore represent a serious threat for conservation of cultural assets, in both outdoor and indoor sites, such as libraries, archives, museum institutions, deposits) and all the places where the conservation/use of artifacts is implemented. Generally, all conservation/fruition sites show signs of either partial or extensive infestation/colonization, involving the hosted artifacts. Biological systems, strongly related to environmental parameters and characteristics of the constitutive materials, are able to induce a range of sufficiently wide alterations. The biodeteriogens can cause chemical (related to the effect of metabolic products), physical (related to penetration of microbial cells or structural elements) and aesthetic (coatings, biofilms) damages.
Therefore, it is essential to establish the presence of macro and microorganisms and to identify them, in order to promptly and effectively intervene to restrain the damage, before it becomes irreversible. In this context, electron microscopy, both scanning (SEM) and confocal laser scanning (CLSM) represent scientific tools of great interest in the diagnostic field
Valutazione dello stato di conservazione dei popolamenti a Cystoseira lungo le coste della Sicilia nord-occidentale: osservazioni preliminari
No full textEffetti dell’impatto antropico e della geometria del substrato su struttura e distribuzione delle comunità bentoniche di fouling
No full textEffetto dell’impatto antropico e geometria del substrato sulla distribuzione e struttura delle comunità bentoniche vegetali di fouling
No full textPercorsi di student-centered learning negli insegnamenti di area naturalistico-biologica dell’Università di Palermo
No full textLa didattica innovativa mira a creare un ambiente di apprendimento stimolante, centrato sullo studente e sullo sviluppo di competenze trasversali. Questo approccio formativo è il fondamento del Progetto “Mentori per la didattica” (PM) dell’Università di Palermo, nato nel 2013 e ora una best practice dell’Ateneo. Il progetto ha l’obiettivo di migliorare la qualità della didattica, attraverso il peer mentoring e un programma di formazione del corpo docente dove trova spazio la contaminazione tra materie STEM e temi pedagogici.
Un gruppo di docenti del PM ha messo in pratica le strategie apprese e ha adottato percorsi di student-centered learning in insegnamenti di lauree scientifiche triennali e magistrali, ottenendo buoni risultati
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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