298 research outputs found
Micro-Raman characterizations of Pompei'smortars
The ancient town of Pompei offers a unique opportunity to study in detail many aspects of the every day life during the Roman early imperial age. The application of micro-Raman spectroscopy can be of great help in performing a reasonably rapid comparative analysis of the mortars, quite useful to ascertain the degree of uniformity of the technical recipes among the various building firms and the eventual technical evolution in the time; moreover, the individuation of minerals of specific geographical origins can give useful information about the extension of commercial intercourses. An example of a micro-Raman investigation on building materials is reported in this work, concerning the analysis of the mortars coming from different points of the wall in the 'The House of the Wedding of Hercules'. Remarkable differences between ancient and modern mortars are found, allowing a discrimination that can be useful in the case of historical building which underwent several restoration works. Copyright © 2008 John Wiley & Sons, Ltd
Chromosome analysis using different staining techniques and fluorescent in situ hybridization in Cerithium vulgatum Bruguière
A semi-automatic methodology for tire’s wear evaluation
In this work, the authors aim at developing a reliable and fast methodology to evaluate the wear evolution in tire starting from a complete optical 3D scanning. Starting from a data cloud, a semi-automatic methodology was implemented in MATLAB to extract mean tread radial profiles in correspondence of the desired angular position of the tire. These profiles could be numerically evaluated to establish the presence of irregular wear and the characteristic parameter of the groove depth. The reliability and the robustness of this methodology was firstly tested by applying it to several synthetic case studies modeled in CATIA V5®, where ovalization and presence of defects were also simulated. The groove depth was determined with an error lower than 1% for the ideal model, while the introduction of ovalization and defects leaded to an error of 2.6% in the worst condition. In a second time, the methodology has been successfully applied to experimental measurements carried out in two different wear life of the tire, allowing the tracking of the wear phenomena through the evaluation of the progressive lowering of tread radial profiles
Chromosome analysis using different staining techniques and fluorescent in situ hybridization in Cerithium vulgatum (Gastropoda: Cerithiidae)
In the present paper one population of the "large" subtidal mollusc Cerithium vulgatum Bruguiere, 1792 (Gastropoda: Cerithiidae) from the Northwestern coast of Sicily was investigated from a karyological point of view. The chromosome complement was Giemsa stained, conventionally karyotyped in 18 homomorphic chromosome pairs (10 bi-armed and 8 mono-armed), and subsequently analysed using silver, CMA3 and DAPI staining, and fluorescent in situ hybridization (FISH) with three repetitive DNA probes [ribosomal DNA (rDNA), (TTAGGG)n and (GATA)n]. FISH with the rDNA probe consistently mapped major ribosomal sites (18S-28S rDNA) in the terminal region of the short arms of one small sized mono-armed chromosome pair. Ribosomal DNA was transciptionally active as indicated by its preferential impregnation with silver nitrate (Ag-NOR) and did not contain a high amount of GC base pairs as suggested by the lack of a bright CMA3 fluorescence. The (TTAGGG)n telomeric probe was hybridized to the termini of nearly all chromosomes, thus demonstrating that, in C. vulgatum, this sequence has been conserved during the genomic evolution. The finding of the telomeric hexanucleotide in six species belonging to the three high taxa of Gastropoda supports the notion that this sequence is widespread within this class. The (GATA)n probe did not label any chromosome regions except for a minute terminal area of a single bivalent at pachytene stage
Ileal metastasis from thoracic melanoma disclosed by video capsule endoscopy: an unusual but not extraordinary source of obscure bleeding
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Sneaking into a Hotspot of Biodiversity: Coverage and Integrity of a Rhodolith Bed in the Strait of Sicily (Central Mediterranean Sea)
Habitat mapping, physical characteristics and benthic community of a rhodolith bed in the Pelagie Islands (Strait of Sicily, Mediterranean Sea) were studied through Multi–Beam Echo–Sounder (MBES), Remotely Operated Vehicle (ROV) and grab samples. The geomorphological analysis revealed an articulated and wide rhodolith bed; video inspections highlighted a bed with high coverage, few sandy patches and with a prevalence of the boxwork morphotype. A total of 207 taxa with 876 specimens were identified, and Polychaeta was the dominant taxon. Linguimaera caesaris, a Lessepsian benthic amphipod, was recorded in all sampling sites, and its presence represents an input to deepen the benthic assemblage research on the rhodolith bed. In terms of morphotype composition, dead/live ratio and species variability, the bed variability indicated a good status of health, although trawling signs were detected through ROV videos. The present study broadens the knowledge on Mediterranean rhodolith beds and supports the importance of survey and monitoring activities for the conservation and management of this important habitat
Preliminary observations of caulerpin accumulation from the invasive Caulerpa cylindracea in native Mediterranean fish species
Recent studies have shown that the Mediterranean white sea bream Diplodus sargus includes the invasive green alga Caulerpa cylindracea in its diet, with consequent metabolic and enzymatic alterations. As a result of this novel alimentary habit, the bioactive algal red pigment caulerpin has been detected in its tissues. However, this may not be an isolated case: other fish species have also been reported to feed on C. cylindracea, although the possible accumulation of caulerpin in their tissues has not yet been investigated. In this report, we analysed stomach contents and caulerpin levels in the native sparid species Spondyliosoma cantharus, Sarpa salpa, and Diplodus vulgaris, and in the scarid Sparisoma cretense, along with the Lessepsian siganid Siganus luridus. C. cylindracea was found in the stomachs of all but one fish species, the exception being S. cretense, in which prey items could not be determined due to the high degree of digestion. Chemical analysis of fish tissues revealed that only S. cantharus and S. salpa accumulated caulerpin, while no traces of the compound were detected in the other species. Despite intense research efforts on natural products obtained from C. cylindracea, a complete picture of the impacts caused by fish including this alga in their diet has not been elucidated. The identification of caulerpin in other Mediterranean native fish suggests a need for further research in order to assess the possible transfer of such molecules to humans through seafood consumption
Reproductive cycle and gonadal output of the Lessepsian jellyfish Cassiopea andromeda in NW Sicily (Central Mediterranean Sea)
Knowledge of the reproductive strategy is a key prerequisite to predict population dynamics and potential invasiveness of both native and non-indigenous outbreak-forming species. In 2014 the Lessepsian upside-down jellyfish Cassiopea andromeda reached the harbor of Palermo (NW Sicily, Thyrrenian Sea), to date its established westernmost outpost in the Mediterranean Sea. To predict C. andromeda reproductive success in its novel habitat, gonad histology was carried out to record the number and size of mature and immature oocytes. Both male and female simultaneously presented gametes at all stages of development suggesting an asynchronous, yet apparently continuous, reproduction strategy. Indeed, oogenesis was observed throughout the year from pre-vitellogenic, vitellogenetic, and late-vitellogenetic to mature oocytes suggesting multiple reproductive events, as known in other Mediterranean Rhizostomeae. Oocytes were found from May to December, with two seasonal peaks of abundance (late spring = 392 and autumn = 272), suggesting imminent spawning events. Further, jellyfish size varied significantly throughout the year, with maximum diameter (up to 24 cm) in summer, and minimum diameter (6 cm) in winter. Small-sized jellyfish in winter belong to the new cohort, most probably arising from intense summer strobilation of polyps. Late spring fertilization, planula development, and metamorphosis, followed by polyp strobilation in the summer months, may explain the late appearance of a new jellyfish cohort, likely coincident with that recorded throughout winter
Marine alien species in Italy: A contribution to the implementation of descriptor D2 of the Marine Strategy Framework Directive
A re-examination of marine alien species or Non Indigenous Species (NIS) reported in Italian Seas, until December 2018, is provided, focusing on establishment success, year of first record, origin, potential invasiveness, and likely pathways, in particular. Furthermore, their distribution is assessed according to the marine subregions outlined by the European Union (EU) Marine Strategy Framework Directive: Adriatic Sea (ADRIA), Ionian Sea and Central Mediterranean Sea (CMED), and Western Mediterranean Sea (WMED). In Italy, 265 NIS have been detected with the highest number of species being recorded in the CMED (154 species) and the WMED (151 species) subregions, followed by the ADRIA (143) subregion. Most of these species were recorded in more than one subregion. One hundred and eighty (180 or 68%) NIS have established stable populations in Italian Seas among which 26 have exhibited invasive traits. As regards the taxa involved, Macrophyta rank first with 65 taxa. Fifty-five of them are established in at least one subregion, mostly in the ADRIA and the CMED. Crustacea rank second with 48 taxa, followed by Polychaeta with 43 taxa, Mollusca with 29 taxa, and Fishes with 28 taxa, which were mainly reported from the CMED. In the period 2012-2017, 44 new alien species were recorded, resulting in approximately one new entry every two months. Approximately half of the NIS (~52%) recorded in Italy have most likely arrived through the transport-stowaway pathway related to shipping traffic (~28% as biofoulers, ~22% in ballast waters, and ~2% as hitchhikers). The second most common pathway is the unaided movement with currents (~19%), followed by the transport-contaminant on farmed shellfishes pathway (~18%). "Unaided" is the most common pathway for alien Fishes, especially in the CMED; escapes from confinement account for ~3% and release in nature for ~2%. The present NIS distribution hotspots for new introductions were defined at the first recipient area/location in Italy. In the ADRIA, the hotspot, Venice, accounts for the highest number of alien taxa introduced in Italy, with 50 newly recorded taxa. In the CMED subregion, the hotspots of introduction are the Taranto and Catania Gulfs, hosting 21 first records each. The Strait of Sicily represents a crossroad between alien taxa from the Atlantic Ocean and the Indo-Pacific area. In the WMED, bioinvasion hotspots include the Gulfs of Naples, Genoa and Livorno. This review can serve as an updated baseline for future coordination and harmonization of monitoring initiatives under international, EU and regional policies, for the compilation of new data from established monitoring programs, and for rapid assessment surveys
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