63 research outputs found

    Haliotis mykonosensis Owen, Hanavan & Hall, 2001 in the Procida Island (Gulf of Naples) and in the Central Mediterranean Sea, with notes on the Mediterranean HALIOTIDAE

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    Seventeen living specimens of Haliotis mykonosensis Owen, Hanavan & Hall, 2001 are reported from the area between the wharf of Sancio Cattolico and Punta di Pioppeto (northern side of Procida Island, Naples) and twenty-six from further Central Mediterranean localities. The species was known up to now from the original description only and this note contributes to a better understanding of its real distribution in the Mediterranean Sea

    Imbalance of peptidoglycan biosynthesis alters the cell surface charge of Listeria monocytogenes

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    The bacterial cell wall is composed of a thick layer of peptidoglycan and cell wall polymers, which are either embedded in the membrane or linked to the peptidoglycan backbone and referred to as lipoteichoic acid (LTA) and wall teichoic acid (WTA), respectively. Modifications of the peptidoglycan or WTA backbone can alter the susceptibility of the bacterial cell towards cationic antimicrobials and lysozyme. The human pathogen Listeria monocytogenes is intrinsically resistant towards lysozyme, mainly due to deacetylation and O-acetylation of the peptidoglycan backbone via PgdA and OatA. Recent studies identified additional factors, which contribute to the lysozyme resistance of this pathogen. One of these is the predicted ABC transporter, EslABC. An eslB mutant is hyper-sensitive towards lysozyme, likely due to the production of thinner and less O-acetylated peptidoglycan. Using a suppressor screen, we show here that suppression of eslB phenotypes could be achieved by enhancing peptidoglycan biosynthesis, reducing peptidoglycan hydrolysis or alterations in WTA biosynthesis and modification. The lack of EslB also leads to a higher negative surface charge, which likely stimulates the activity of peptidoglycan hydrolases and lysozyme. Based on our results, we hypothesize that the portion of cell surface exposed WTA is increased in the eslB mutant due to the thinner peptidoglycan layer and that latter one could be caused by an impairment in UDP-N-acetylglucosamine (UDP-GlcNAc) production or distribution

    Establishing Human Lacrimal Gland Cultures with Secretory Function

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    PURPOSE: Dry eye syndrome is a multifactorial chronic disabling disease mainly caused by the functional disruptions in the lacrimal gland. The treatment involves palliation like ocular surface lubrication and rehydration. Cell therapy involving replacement of the gland is a promising alternative for providing long-term relief to patients. This study aimed to establish functionally competent lacrimal gland cultures in-vitro and explore the presence of stem cells in the native gland and the established in-vitro cultures. METHODS: Fresh human lacrimal gland from patients undergoing exenteration was harvested for cultures after IRB approval. The freshly isolated cells were evaluated by flow cytometry for expression of stem cell markers ABCG2, high ALDH1 levels and c-kit. Cultures were established on Matrigel, collagen and HAM and the cultured cells evaluated for the presence of stem cell markers and differentiating markers of epithelial (E-cadherin, EpCAM), mesenchymal (Vimentin, CD90) and myofibroblastic (α-SMA, S-100) origin by flow cytometry and immunocytochemistry. The conditioned media was tested for secretory proteins (scIgA, lactoferrin, lysozyme) post carbachol (100 ”M) stimulation by ELISA. RESULTS: Native human lacrimal gland expressed ABCG2 (mean±SEM: 3.1±0.61%), high ALDH1 (3.8±1.26%) and c-kit (6.7±2.0%). Lacrimal gland cultures formed a monolayer, in order of preference on Matrigel, collagen and HAM within 15-20 days, containing a heterogeneous population of stem-like and differentiated cells. The epithelial cells formed 'spherules' with duct like connections, suggestive of ductal origin. The levels of scIgA (47.43 to 61.56 ng/ml), lysozyme (24.36 to 144.74 ng/ml) and lactoferrin (32.45 to 40.31 ng/ml) in the conditioned media were significantly higher than the negative controls (p<0.05 for all comparisons). CONCLUSION: The study reports the novel finding of establishing functionally competent human lacrimal gland cultures in-vitro. It also provides preliminary data on the presence of stem cells and duct-like cells in the fresh and in-vitro cultured human lacrimal gland. These significant findings could pave way for cell therapy in future

    Current status and trends of biological invasions in the Lagoon of Venice, a hotspot of marine NIS introductions in the Mediterranean Sea

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    This paper provides an updated account of the occurrence and abundance of non-indigenous species (NIS) in an area of high risk of introduction: the Lagoon of Venice (Italy). This site is a known hotspot of NIS introductions within the Mediterranean Sea, hosting all the most important vectors of introduction of marine NIS—shipping, recreational boating, shellfish culture and live seafood trade. The recent literature demonstrates that the number of NIS in Venice is continuously changing, because new species are being introduced or identified, and new evidence shows either an exotic origin of species previously believed to be native, or a native origin of formerly believed ‘‘aliens’’, or demonstrates the cryptogenic nature of others. The number of NIS introduced in the Venetian lagoon currently totals 71, out of which 55 are established. This number exceeds those displayed by some nations like Finland, Portugal or Libya. Macroalgae are the taxonomic group with the highest number of introduced species (41 % of NIS): the most likely vector for their introduction is shellfish culture. The source region of NIS introduced to Venice is mainly represented by other Mediterranean or European sites (76 %). The Lagoon of Venice represents a sink but also a source of NIS in the Mediterranean Sea, as it is the site of first record of several NIS, which have since further spread elsewhere.This paper provides an updated account of the occurrence and abundance of non-indigenous species (NIS) in an area of high risk of introduction: the Lagoon of Venice (Italy). This site is a known hotspot of NIS introductions within the Mediterranean Sea, hosting all the most important vectors of introduction of marine NIS-shipping, recreational boating, shellfish culture and live seafood trade. The recent literature demonstrates that the number of NIS in Venice is continuously changing, because new species are being introduced or identified, and new evidence shows either an exotic origin of species previously believed to be native, or a native origin of formerly believed "aliens", or demonstrates the cryptogenic nature of others. The number of NIS introduced in the Venetian lagoon currently totals 71, out of which 55 are established. This number exceeds those displayed by some nations like Finland, Portugal or Libya. Macroalgae are the taxonomic group with the highest number of introduced species (41 % of NIS): the most likely vector for their introduction is shellfish culture. The source region of NIS introduced to Venice is mainly represented by other Mediterranean or European sites (76 %). The Lagoon of Venice represents a sink but also a source of NIS in the Mediterranean Sea, as it is the site of first record of several NIS, which have since further spread elsewhere

    Il tempo richiesto per l\u2019esodo e il pre-movimento nell\u2019evacuazione.

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    Con il trascorrere degli anni si \ue8 capito che per gestire correttamente un\u2019emergenza e per progettare adeguatamente un edificio \ue8 necessario prevedere le dinamiche mentali di coloro che si trovano coinvolti nell\u2019evento critico e che si apprestano ad evacuare l\u2019immobile. \uc8 necessario infatti considerare le variabili psicosociali che intervengono in ognuno di noi al fine di prevedere il pi\uf9 possibile le tempistiche richieste per raggiungere un luogo sicuro. Queste valutazioni sono trattate anche nel D.M. del 3 agosto 2015 dove sono tenuti in considerazione e sono brevemente descritti, i comportamenti psicosociali che determinano il ritardo nell\u2019esodo. Andiamo perci\uf2 ad analizzare nel dettaglio cosa succede alla nostra mente durante l\u2019emergenza

    Cell shape and antibiotic resistance is maintained by the activity of multiple FtsW and RodA enzymes in Listeria monocytogenes

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    Rod-shaped bacteria have two modes of peptidoglycan synthesis: lateral synthesis and synthesis at the cell division site. These two processes are controlled by two macromolecular protein complexes, the elongasome and divisome. Recently, it has been shown that the Bacillus subtilis RodA protein, which forms part of the elongasome, has peptidoglycan glycosyltransferase activity. The cell division specific RodA homolog FtsW fulfils a similar role at the divisome. The human pathogen Listeria monocytogenes encodes up to six FtsW/RodA homologs, however their functions have not yet been investigated. Analysis of deletion and depletion strains led to the identification of the essential cell division-specific FtsW protein, FtsW1. Interestingly, L. monocytogenes encodes a second FtsW protein, FtsW2, which can compensate for the lack of FtsW1, when expressed from an inducible promoter. L. monocytogenes also possesses three RodA homologs, RodA1, RodA2 and RodA3 and their combined absence is lethal. Cells of a rodA1/rodA3 double mutant are shorter and have increased antibiotic and lysozyme sensitivity, probably due to a weakened cell wall. Results from promoter activity assays revealed that expression of rodA3 and ftsW2 is induced in the presence of antibiotics targeting penicillin binding proteins. Consistent with this, a rodA3 mutant was more susceptible to the ÎČ-lactam antibiotic cefuroxime. Interestingly, overexpression of RodA3 also led to increased cefuroxime sensitivity. Our study highlights that L. monocytogenes encodes a multitude of functional FtsW and RodA enzymes to produce its rigid cell wall and that their expression needs to be tightly regulated to maintain growth, cell division and antibiotic resistance

    An Auction Based Approach in Decentralized Project Scheduling

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    We consider project scheduling problems on a decentralized decisional framework, where a project is partitioned into different sub-projects each one managed by a local decision maker. A coordination mechanism has to be considered to resolve shared resource allocation conflicts between different sub-projects. We propose a multi agent system model to represent the decentralized decisional problem, where each agent interacts with the others using an auction mechanism to perform his/her activities and to resolve the conflicts derived from the limited shared resources capacity

    Vegetation of the Onferno Nature Reserve (Rimini-Central Italy) and management problems of secondary grasslands.

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    This study presents a floristic and vegetational analysis of the territory of the Onferno Nature Reserve. The site extends over about 120 hectares, and is located in central Italy, in a hilly area near the Adriatic coast. It is characterised by the presence of large gypsum blocks that have karst caves, where important colonies of bats lives. This study of the vegetation allowed the description of six main vegetation series, divided into three different geosigmeta: a geomorphological unit of gypsum substrata (Gessi di Onferno); a geomorphological unit of clay substrata (Formazione del Santerno); and a geomorphological unit of compact sandstone substrata (Formazione Montecalvo in Foglia). This floristic and vegetation studies carried out on the secondary grasslands (EC Habitat 6210) have allowed the evaluation of the grazing effects on the conservation of their biodiversity, and highlight the critical nature of this management method. Furthermore, on the basis of the vegetation studies, the list of habitats according to EC Directive 92/43/CEE has been better defined and updated
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