Neuropilin 2 expression and function in melanocytes and melanoma

Neuropilin 2 (NRP2) is a transmembrane protein receptor originally discovered in neurons, and their precursors, neural crest cells (NCC), which are a transient, migratory precursor population derived from neural ectoderm. NRP2 serves as both a vascular endothelial growth factor (VEGF) co-receptor to initiate a pro-angiogenic signaling cascade and as a receptor for the class 3 semaphorin family molecules (primarily SEMA3F). Binding of SEMA3F induces a strong repulsive and antiangiogenic signal. NRP2 was discovered on melanocytes, which was a novel finding. NRP2-positive melanocytes were first identified in the hair follicles of Nrp2+/gfp transgenic mouse model. It is known that melanocytes reside in the bulb of the hair, where they provide pigment. Melanocyte stem cell populations are found in the bulge, a superficial structure also containing keratinocyte precursors. NRP2 has also been suggested as a potential biomarker in cases of malignant melanoma. The aim of this study was to elucidate the role of NRP2 three areas: in the growth and development of hair, in melanocytes, and in malignant melanoma. A greater understanding of the role of NRP2 in these locales may have significant clinical significance in disease states such as alopecia, vitiligo, and melanoma. It was discovered that Nrp2 expression was strongest within the bulge region of the hair follicle where melanocyte stem cells reside. Additionally, human and mouse primary melanocytes express NRP2, whereas keratinocytes do not. Neither melanocytes nor melanoma express VEGFR2, indicating NRP2 may be serving as a SEMA3F receptor. The NRP2 receptor was functional in melanocytes as treatment with SEMA3F inhibited migration of both melanocytes and melanoma cultured lines. Melanoma cells downregulate expression of SEMA3F and upregulate the expression of NRP2. In the patient samples analyzed, the expression of NRP2 correlated with disease progression

The First Occurrence of Asbestiform Magnesio-Riebeckite in Schists in the Frido Unit (Pollino Unesco Global Geopark, Southern Italy)

In this paper, new mineralogical and petrographical data of asbestiform Magnesio-riebeckite from ophiolite cropping out in the Pollino Unesco Global Geopark (southern Italy) are presented. Magnesio-riebeckite schists with HP-LT index mineral assemblage recorded metamorphic events in blueschist facies in the Frido Unit. Previous toxicological studies showed that asbestiform Magnesio-riebeckite species exhibited high carcinogenicity in previous intraperitoneal injection experiments with rats. The results have been obtained using different analytical techniques such as X-ray fluorescence (XRF), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), and electron probe micro analysis (EPMA). Results show that all the samples contain fibrous Magnesio-riebeckite and/or prismatic, acicular crystals in aggregates. The concentration of elements in Magnesio-riebeckite crystals is: Na2O (4.12–6.26 wt%), MgO (8.22–10.87 wt%), FeO (19.07–23.81 wt%), SiO2 (52.05–56.06 wt%), CaO (1.12–4.53 wt%), Al2O3 (1.34–1.93 wt%), and MnO (0.10–0.34 wt%). Magnesio-riebeckite crystals are documented in the Pollino Unesco Global Geopark for the first time. For this reason, the aim of this paper is the characterization of Magnesio-riebeckite to improve the knowledge of this mineral in the studied area, because the release of fibers into the environment is dangerous for human health

Fast training of self organizing maps for the visual exploration of molecular compounds

Visual exploration of scientific data in life science area is a growing research field due to the large amount of available data. The Kohonen’s Self Organizing Map (SOM) is a widely used tool for visualization of multidimensional data. In this paper we present a fast learning algorithm for SOMs that uses a simulated annealing method to adapt the learning parameters. The algorithm has been adopted in a data analysis framework for the generation of similarity maps. Such maps provide an effective tool for the visual exploration of large and multi-dimensional input spaces. The approach has been applied to data generated during the High Throughput Screening of molecular compounds; the generated maps allow a visual exploration of molecules with similar topological properties. The experimental analysis on real world data from the National Cancer Institute shows the speed up of the proposed SOM training process in comparison to a traditional approach. The resulting visual landscape groups molecules with similar chemical properties in densely connected regions

Dating of marine sediments by using unsupported 210Pb method

In the framework of a more general study on marine species in sediments, it was necessary to obtain a time calibration of the different sections of the sampled sediment columns, both to estimate the pollution of the sediments and, particularly, to study the migration of foraminifers within the column. The method of the unsupported 210Pb, i.e. whose activity is not derived from the radioactive decay of its 226Ra parent, has been used. Since the activity of the supported 210Pb can be determined from the activity of 226Ra, the unsupported 210Pb activity can be calculated as the difference between 210Pb total and 226Ra activities. The unsupported 210Pb decays with its own half-life time, equal to 22.3 years, so being very suitable to the aim of dating the sediment column we are interested in. The 226Ra activity has been determined through high performance gamma spectrometry with a low-energy detector of 214Pb gamma emission (351.9 keV), after secular equilibrium has been reached. The activity of 210Pb was determined by its 46.5 keV gamma emission. As experimental test, the age of a column taken in the Palermo bay (Sicily) has been estimated being about 50 years and the average sedimentation rate as equal to about 0.6 cm y-1. Goodness of dating has been checked measuring the 137Cs activity in the same sediment column. Using the above sedimentation rate, the maximum in cesium activity vs. year can be estimated to occur around the year 1986, obviously due the Chernobyl event

Context-aware visual exploration of molecular databases

Facilitating the visual exploration of scientific data has received increasing attention in the past decade or so. Especially in life science related application areas the amount of available data has grown at a breath taking pace. In this paper we describe an approach that allows for visual inspection of large collections of molecular compounds. In contrast to classical visualizations of such spaces we incorporate a specific focus of analysis, for example the outcome of a biological experiment such as high throughout screening results. The presented method uses this experimental data to select molecular fragments of the underlying molecules that have interesting properties and uses the resulting space to generate a two dimensional map based on a singular value decomposition algorithm and a self organizing map. Experiments on real datasets show that the resulting visual landscape groups molecules of similar chemical properties in densely connected regions

Impiego di un sistema spettrometrico gamma portatile basato su uno scintillatore LaBr3(Ce)

La risoluzione energetica di uno scintillatore LaBr3(Ce) è decisamente superiore (<3% a 662 keV) rispetto a quella di un più tradizionale scintillatore NaI(Tl) anche se ancora decisamente non comparabile con quella dei rivelatori a Ge. Questa caratteristica del rivelatore, oltre il ridotto tempo di risposta, lo rende adatto per misure “in situ” specialmente quando è importante l’individuazione rapida in uno spettro gamma di manifestazioni fotoelettriche con energia molto prossime tra loro (individuazione di sorgenti o rifiuti radioattivi, misure nel campo delle salvaguardie nucleari, …). Una significativa limitazione nel suo impiego è tuttavia rappresentata dalla elevata radioattività intrinseca che, per determinati range energetici e per alcune tipologie di misura di materiali di origine naturale (es. NORM, materiali da costruzione, suoli, ..), influisce direttamente sui limiti di rivelazione del sistema di misura. Un caso tipico è quello della determinazione, in alcune matrici ambientali, della concentrazione di 40K la cui emissione gamma interferisce con quella del 138La, naturalmente presente all’interno del rivelatore. Fortunatamente questa limitazione non è rilevante nel range energetico 60-1200 keV, in cui ricadono le energie delle principali emissioni gamma di molti radioisotopi naturali e artificiali. In questo lavoro, dopo aver predisposto un sistema spettrometrico gamma portatile basato su uno scintillatore 2”×2” LaBr3(Ce) della Saint-Gobain (BrilLianCe™380) associato a una interfaccia USB- Multicanale (1024 canali) Digibase della ORTEC, con alimentazione indipendente (tramite batterie ricaricabili), sono state valutate le possibilità di impiego e la sua versatilità tramite misure spettrometriche gamma di varia tipologia: dalla identificazione e quantificazione di radioisotopi in diversi materiali, all’esame dei filtri di verifica della contaminazione in sorgenti di alta attività (smear tests), dalle misure per caratterizzare rifiuti radioattivi o prodotti attivati in pezzi provenienti dalla manutenzione di un ciclotrone per uso medicale alla identificazione di composti di torio o uranio e del relativo arricchimento, etc. Il sistema spettrometrico è risultato, in conclusione, particolarmente versatile potendosi ritenere molto promettente il suo impiego in tutte quelle applicazioni in campo ove non è possibile o risulta molto complicato impiegare un rivelatore a semiconduttore. La sensibilità dello strumento, per le dimensioni degli scintillatori che oggi si riescono a costruire, risulta molto prossima se non superiore ai sistemi di misura portatili più comuni mentre la compattezza, leggerezza e i contenuti consumi energetici ne favoriscono l’utilizzo in campo

La scenografia degli stucchi del Serpotta rivisitata. La materia e la forma

The material that lies beneath the smooth shining surface of the stuccoes of the Serpotta family who used to work in Sicily from 1670 to 1730, has been thoroughly studied in previous papers, disclosing the deep, albeit empirical, knowledge of materials science that guided the artists in creating their masterpieces. In this work, attention is focused on the solid perspective and on the scenographic sculpture by Giacomo Serpotta, who is acknowledged as the leading exponent of the School. The study deals with some particular works of the artist, the “small-scaled plastic theatres”, so-called “teatrini”, which he made for the San Lorenzo Oratory in Palermo. On the basis of archival documents and previous analogical photogrammetric plotting, integrated with digital solutions and computer-based technologies, the study investigates and interprets the geometric-formal genesis of the examined works of art. Knowledge of the material composition of the stuccoes, along with the ability to accurately reproduce their shapes, give interesting possibilities to provide a complete reading of the works of art damaged by deterioration or theft.La materia che si nasconde sotto le levigate e lucenti superfici degli stucchi della famiglia dei Serpotta, che operò in Sicilia tra il 1670 e il 1730, è stata ampiamente studiata in precedenti lavori, rivelando la profonda, se pur empirica, conoscenza della Scienza dei Materiali che guidava gli artisti nella realizzazione dei loro capolavori. In questo studio l’attenzione viene posta sulla prospettiva solida e sulla scultura scenografica dello scultore palermitano Giacomo Serpotta, riconosciuto come il principale esponente della Scuola. L’indagine si concentra su particolari opere dell’artista, i cosiddetti “teatrini plastici”, da lui eseguiti per l’Oratorio di San Lorenzo nel centro antico di Palermo. Sulla base di documenti di archivio e rilevamenti stereo fotogrammetrici analogici pregressi, integrati con tecniche di acquisizione dati di ultima generazione, lo studio presenta elaborazioni digitali che hanno permesso ricostruzioni virtuali a video di elementi scultorei non più esistenti. La conoscenza dei materiali che compongono le opere in stucco, insieme alla capacità di riprodurre con precisione le forme, offre interessanti possibilità di fornire una lettura completa delle opere d’arte danneggiate dal deterioramento o dal furto

Temporal trends of heavy metals in sediment core from the gulf of Palermo (Sicily, Italy)

The evaluation of long–term heavy metal concentrations in the Gulf of Palermo was carried out in this study. Measurements of Cr, Cu, Hg, Pb and Zn concentrations were performed by atomic absorption spectrophotometry (AAS) on dated fractions of a sediment core, dated by the 210Pbex method. They are found to cover a time period from 1951 to 2004. The constant sedimentation rate model was used for dating. Specific activities of 137Cs have also been measured in the sediment core sections as a check of the time scale derived by the 210Pbex method. A time-series analysis based on temporal decomposition was used in order to investigate the presence of heavy metal pollution trend. The additive component model, widely used to estimate seasonal and long–term behavior, was chosen for the temporal analysis. Results showed the presence of a specific heavy metal concentration trend. Residual time–autocorrelation has also been taken into account in order to investigate their stochastic properties. Concentrations of some metals (Cu, Hg, and Zn) have been found increasing until the beginning of the 1970s. A peak around the beginning of the 1980s has been found for Cr and Pb. Heavy metal concentration in the sediment core show a significant decreasing after these years. Our results for the concentration time trends are in good agreement with other surveys performed in different areas of the world, and they can be explained in terms of the reduction of anthropogenic contribution to atmospheric emissions. Further investigations on time properties and spatial distributions, are also planned