39 research outputs found

    Comparazione dei metodi di valutazione della vulnerabilitĂ  costiera nella piana del Sele (Salerno).

    Get PDF
    La ricerca interdisciplinare degli ultimi 20 anni evidenzia il rischio da erosione che colpisce molte coste sottoposte ad arretramento e inondazione da parte delle azioni naturali. Le condizioni critiche di vulnerabilità costiera possono diventare più gravi in particolare nelle pianure costiere, che ospitano importanti centri urbani e industriali, infrastrutture e attività turistiche, spesso accoppiate con paesaggi tutelati e / o siti archeologici. Pertanto è necessaria una corretta valutazione della vulnerabilità costiera, tenendo conto sia della vulnerabilità da inondazioni costiere sia da erosione. In questo lavoro viene valutata la vulnerabilità da eventi meteomarini estremi della piana costiera del Sele (Salerno). La stima della vulnerabilità viene effettuata combinando sia l’erosione a breve termine che quella a lungo termine valutata attraverso una simulazione numerica delle onde e le caratteristiche morfo-sedimentarie della spiaggia. L'analisi dell’evoluzione costiera per effetto della tempesta è stata esaminata per mezzo di due indicatori, calcolati lungo un certo numero di profili di spiaggia realizzati tra il 2008 e il 2009: il wave run-up (come misura di inondazione costiera) e l’arretramento della spiaggia (come misura dell’erosione potenziale). Inoltre, l’evoluzione costiera a lungo termine è stata valutata attraverso i tassi di erosione derivati dal confronto di ortofoto in sequenze multi-temporali e multi-scala. I risultati sono stati espressi utilizzando diversi indici di vulnerabilità costiera, ottenuti sommando i punteggi relativi alla erosione a breve termine ea lungo termine. L'esame dei risultati finali ha evidenziato diverse risposte dei profili costieri in funzione dell’indice utilizzato

    Doenças inflamatórias intestinais: princípios da terapia nutricional

    Get PDF
    Inflammatory Bowel Diseases - ulcerative colitis and Crohn's disease- are chronic gastrointestinal inflammatory diseases of unknown etiology. Decreased oral intake, malabsorption, accelerated nutrient losses, increased requirements, and drug-nutrient interactions cause nutritional and functional deficiencies that require proper correction by nutritional therapy. The goals of the different forms of nutritional therapy are to correct nutritional disturbances and to modulate inflammatory response, thus influencing disease activity. Total parenteral nutrition has been used to correct and to prevent nutritional disturbances and to promote bowel rest during active disease, mainly in cases of digestive fistulae with high output. Its use should be reserved for patients who cannot tolerate enteral nutrition. Enteral nutrition is effective in inducing clinical remission in adults and promoting growth in children. Due to its low complication rate and lower costs, enteral nutrition should be preferred over total parenteral nutrition whenever possible. Both present equal effectiveness in primary therapy for remission of active Crohn's disease. Nutritional intervention may improve outcome in certain individuals; however, because of the costs and complications of such therapy, careful selection is warranted, especially in patients presumed to need total parenteral nutrition. Recent research has focused on the use of nutrients as primary treatment agents. Immunonutrition is an important therapeutic alternative in the management of inflammatory bowel diseases, modulating the inflammation and changing the eicosanoid synthesis profile. However, beneficial reported effects have yet to be translated into the clinical practice. The real efficacy of these and other nutrients (glutamine, short-chain fatty acids, antioxidants) still need further evaluation through prospective and randomized trials.As doenças inflamatórias intestinais - retocolite ulcerativa inespecífica e doença de Crohn - são afecções inflamatórias gastrointestinais crônicas de causa ainda desconhecida. Caracterizam-se por diarréia crônica, malabsorção, síndrome do intestino curto, disfunção da barreira mucosa e processo inflamatório intestinal, fatores que determinam deficiências nutricionais e funcionais que ressaltam a importância da terapia nutricional em seu tratamento. As diversas formas de terapia nutricional visam corrigir os distúrbios nutricionais e modular à resposta inflamatória, podendo, desta forma, influir na atividade da doença. A nutrição parenteral total tem sido usada para corrigir os distúrbios nutricionais e proporcionar repouso intestinal na doença ativa. Seu uso deve ser reservado a pacientes que não podem tolerar a nutrição enteral. A nutrição enteral é efetiva em induzir remissão clínica da doença em adultos e promover crescimento em crianças. Devido à baixa incidência de complicações e menor custo, a nutrição enteral deve ser opção preferencial à nutrição parenteral total quando possível. Ambas apresentam igual efetividade na terapia primária na remissão da Doença de Crohn ativa. Embora a terapia nutricional possa melhorar a evolução de muitos pacientes, é necessária uma seleção criteriosa devido a seus custos e complicações, especialmente naqueles que requerem nutrição parenteral total. Recentes pesquisas têm se dedicado ao uso de nutrientes como agentes terapêuticos primários. A imunonutrição com ácidos graxos ômega-3 se constitui numa importante alternativa terapêutica no manuseio das doenças inflamatórias intestinais, modulando o processo inflamatório e modificando o perfil de produção de eicosanóides. Entretanto, a real eficácia deste e outros nutrientes (glutamina, ácidos graxos de cadeia curta) ainda necessitam de novas avaliações por estudos prospectivos, controlados e randomizados

    Long-Term Fluoride Release from Dental Resins Affects STRO-1+ Cell Behavior.

    Get PDF
    Fluoride-releasing restorative dental materials can be beneficial to remineralize dentin and help prevent secondary caries. However, the effects of fluoride release from dental materials on the activity of dental pulp stem cells are not known. Here we investigate whether different fluoride release kinetics from dental resins supplemented with modified hydrotalcite (RK-F10) or fluoride-glass filler (RK-FG10) could influence the behavior of a human dental pulp stem cell subpopulation (STRO-1(+) cells) known for its ability to differentiate toward an odontoblast-like phenotype. The 2 resins, characterized by similar physicochemical properties and fluoride content, exhibited different long-term fluoride release kinetics. Our data demonstrate that long-term exposure of STRO-1(+) cells to a continuous release of a low amount of fluoride by RK-F10 increases their migratory response to transforming growth factor β1 (TGF-β1) and stromal cell-derived factor 1 (SDF-1), both important promoters of pulp stem cell recruitment. Moreover, the expression patterns of dentin sialoprotein (dspp), dentin matrix protein 1 (dmp1), osteocalcin (ocn), and matrix extracellular phosphoglycoprotein (mepe) indicate a complete odontoblast-like cell differentiation only when STRO-1(+) cells were cultured on RK-F10. On the contrary, RK-FG10, characterized by an initial fluoride release burst and reduced lifetime of the delivery, did not elicit any significant effect on both STRO-1(+) cell migration and differentiation. Taken together, our results highlight the importance of taking into account fluoride release kinetics in addition to fluoride concentration when designing new fluoride-restorative materials

    Identification and Characterisation of a Novel Acylpeptide Hydrolase from Sulfolobus Solfataricus: Structural and Functional Insights

    Get PDF
    A novel acylpeptide hydrolase, named APEH-3Ss, was isolated from the hypertermophilic archaeon Sulfolobus solfataricus. APEH is a member of the prolyl oligopeptidase family which catalyzes the removal of acetylated amino acid residues from the N terminus of oligopeptides. The purified enzyme shows a homotrimeric structure, unique among the associate partners of the APEH cluster and, in contrast to the archaeal APEHs which show both exo/endo peptidase activities, it appears to be a “true” aminopeptidase as exemplified by its mammalian counterparts, with which it shares a similar substrate specificity. Furthermore, a comparative study on the regulation of apeh gene expression, revealed a significant but divergent alteration in the expression pattern of apeh-3Ss and apehSs (the gene encoding the previously identified APEHSs from S. solfataricus), which is induced in response to various stressful growth conditions. Hence, both APEH enzymes can be defined as stress-regulated proteins which play a complementary role in enabling the survival of S. solfataricus cells under different conditions. These results provide new structural and functional insights into S. solfataricus APEH, offering a possible explanation for the multiplicity of this enzyme in Archaea

    Detached breakwaters, yes or not? A modelling approach to evaluate and plan their removal

    No full text
    Detached breakwaters have been widely employed as a measure against beach erosion and for coastal protection. However, this type of structures may cause different critical issues, and the advantages are not always evident. Water stagnation, rip currents development in the gaps between multiple structures, and obstruction of the natural panorama are well-recognised issues. However, their removal is always problematic because it is generally associated with rapid erosion of the beach and high costs. This work proposes a modelling approach to obtain a preliminary evaluation of a theoretical removal intervention and discusses its possible consequences. The study case is the Moneglia beach, a tourist beach located on the eastern Ligurian coast, NW Italy. The beach is characterised by the presence of three detached breakwaters, arranged over the entire length of the beach. A dataset consisting of LiDAR data, multibeam data, single-beam data and DGPS data was used to obtain an accurate digital elevation model (DEM) of the study area. Subsequently, the XBeach model was used to simulate three scenarios: i) state-of-the-art scenario (S0), ii) detached breakwaters removal scenario (S1), iii) detached breakwaters removal scenario + nourishment (S1N). The S1 scenario was implemented to evaluate the beach morphodynamic response in the case of a removal intervention. S1N was implemented to simulate a beach recovery plan through a beach nourishment intervention. Once the S1N final scenario was obtained, XBeach was implemented to get a comparison with the sea flooding hazard in the S0 and S1 scenarios. The sea flooding hazard assessment was performed considering storm events with a return time of 50 and 100 years, respectively. The results showed both the potential of the XBeach model as a tool and the sustainability of a theoretical detached breakwater removal intervention

    The role of Crassostrea gigas (Thunberg, 1793) in the vertical microplastic transfer: A plankton-benthos linkage laboratory protocol

    No full text
    Microplastics are nowadays recognized as one of the most important pollution sources in the aquatic environment. Their presence has been investigated and certified in various parts of the globe and, most importantly, in a wide variety of species belonging to different trophic levels. However, the process of microplastics vertical distribution among the trophic chains is yet to be disclosed, especially when approaching the plankton-benthos linkage and its consequences in terms of plastic particles transfer from the water column to the benthic biota and environment. We propose a laboratory protocol that simulates microplastics inclusion in organic matter and their subsequent ingestion by the Pacific Oyster Crassostrea gigas (Thunberg, 1793) by the mean of Na-alginate microspheres containing synthetic microplastics. The bivalve sorting mechanisms were also tested by providing phytoplanktonic microalgae and evaluating their proficiency in feeding selectivity. Overall, the Pacific oyster specimens exposed to organic coated microplastics ingested a third (0.1 MP/h vs. 0.3 MP/h) of plastic particles whenever microalgae were available in solution under the same conditions

    Cavity detection using a pseudo-3D electric resistivity tomography at the Palaeolithic/Neolithic site of Scaloria Cave, Apulia, Italy: integrated assessment of synthetic and field data sets

    No full text
    A pseudo-3D electrical resistivity tomography (ERT) survey has been carried out to detect cavities at the Neolithic/Palaeolithic site of Grotta Scaloria, close to Manfredonia, Apulia, Italy. Scaloria Cave has a rich history of archaeological research of more than 80 years and is one of the most important Neolithic complexes in the Mediterranean. Synthetic data modelling allowed to check the adequacy of the geophysical method and to develop a proper experimental setup at the survey design stage. Indeed, the results of the field data inversion revealed high resistivity anomalies which can be related to cavities and provided a good definition of the main geological structures and boundaries. Moreover, the results suggest that unknown and speleological unexplored cavities are still present at the Scaloria Cave study site. These findings may provide further insights on pseudo-3D ERT applicability, particularly for cavity detection. Furthermore, the approach used in this study yields fruitful information for further archaeological survey design and for the interpretation of ERT investigations targeting similar geological features and structures

    Rip currents investigation on a Ligurian pocket beach, NW Mediterranean

    No full text
    Wave-induced currents play a key role in coastal sedimentary and hydrodynamics processes, and in particular, rip currents are probably the most widely studied aspect. Rip currents are characterized by a strong seaward-directed flow, which can transport sediments, planktonic organisms, nutrients, pollutants, and suspended material. However, rip currents are also a hazard for beachgoers and constitute a well known risk to bathers. Several studies have been conducted to describe rip current dynamics and their implications along oceanic beaches, although only a few studies have considered rip dynamics along Mediterranean coasts. This study is an accurate investigation of rip current development in the Levanto pocket beach (Ligurian sea, NW Italy). Coastal video-monitoring, coastal modelling, field surveys, and laboratory analysis are well known methodologies used to study the behaviour of rip currents, but each has its limitations. To overcome this problem, we propose an integrated approach where different tools are integrated among these to obtain mutual validation among several different approaches. The results show how the rip currents investigated in this study can reach and exceed velocities of 1 ms 121, comparable with those of oceanic rip currents, and how these are a key component in the coastal processes that occur along a Mediterranean pocket beach
    corecore