1,721,008 research outputs found
Metagabbros, meta-monzogabbros and metabasites from Serre Massif (Calabria-Italy): evidence of a Neoproterozoic magmatism at crust-mantle transition
No full textDifferent types of Variscan mafic granulites characterize the lower crust of the Serre Massif (Calabria,
Southern Italy). They consist of: layered metagabbros (Pl+Opx+Amph±Cpx±Bt±Qtz±Grt), metric
bodies of meta-monzogabbros (Pl+K-feld+Opx+Cpx+Bt±Qtz±Grt) and lenses or layers of metabasites
(Pl+Opx+Cpx±Bt±Amph±Qtz±Grt) interleaved the overlying migmatitic metapelites and felsic granulites.
The Variscan metamorphic events developed in high grade metamorphic conditions in which partial melting
and fluid interaction were effective (Fornelli et al., 2011, 2014). However, the whole chemical composition
of mafic granulites seems unmodified because migrations of melts at large scale have not been documented.
Therefore, the whole rock compositions of granulite mega-samples can give suggestions about the magmatic
history of their protoliths.
Geochemical data indicate a mantle origin for the Neoproterozoic magmatic protoliths (~570 Ma, Fornelli
et al, 2011). Metagabbros and metabasites show sub-alkaline features (Na2O+K2O=1-5%) with K2O<1%,
whereas meta-monzogabbros display alkaline character (Na2O+K2O=5-7%) with K2O around 3% testified by
Bt and K-feld. In metagabbros, the 87Sr/86Sr(570 Ma) ratio ranges from 0.703 to 0.708 with low values of 87Rb/86Sr
(from 0.001 to 0.024). Metabasites have higher 87Sr/86Sr(570 Ma) values (0.707-0.710) with 87Rb/86Sr ratio from
0.025 to 0.237 Meta-monzogabbros show 87Sr/86Sr(570 Ma) ratio around 0.705 with high 87Rb/86Sr (0.489-0.544).
The εNd(570 Ma) varies from 4.902 to -0.843 in metagabbros, from 0.741 to -2.388 in metabasites, whereas in
meta-monzogabbros assume the values varying from -1.078 to -1.253.
The meta-monzogabbros show a strong mantle affinity but are enriched in incompatible elements, their
origin seems linked to small degree of enriched mantle melting. The metagabbros and metabasites show
crust-mantle interaction for their initial 87Sr/86Sr and εNd(570 Ma) values. We hypothesize that subsequent and
incremental partial melting events (after the production of gabbroic magma) produced mantle melts with
tholeiitic and calc-alkaline affinities migrating in the overlying metasedimentary crust; the stay in hot lower
metasedimentary crust induces a certain grade of crust contamination charged by crustal fluids or melts,
evidenced by the increase of initial 87Sr/86Sr ratio and by decrease of εNd(570 Ma) values at least in protoliths of
metabasites. On the other hand, the placement of metabasites within metasedimentary crust constrains this
suggestion
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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Preliminary U-Pb Detrital Zircon Ages from Tufiti di Tusa Formation (Lucanian Apennines, Southern Italy): Evidence of Rupelian Volcaniclastic Supply
Full text linkU-Pb spot ages have been determined on detrital zircons from two samples of volcaniclastic arenites belonging to the Tufiti di Tusa Formation (TTF) outcropping in the Lucanian Apennines (Southern Italy). Many petrographic and geochemical studies have been performed on these sandstones with the aim of defining their detritus source. A new and precise evaluation of the mineralogical composition of metamorphic lithic fragments, together with U-Pb detrital zircon ages, helps to clarify the deposition age of these syn-sedimentary volcaniclastic sandstones and constrains their source areas. Volcaniclastic arenites consist of andesitic fragments and single minerals of plagioclases, clinopyroxenes, and hornblendes, while the metamorphic lithics are mainly fragments of blue amphibole-bearing micaschists, serpentinites, ophicalcites, phyllites, and medium-grade micaschists. Phaneritic plutonic fragments consist of quartz, feldspar, and micas. Carbonate components include biomicritic and biosparitic fragments. Eighty age data collected from 56 zircons reveal a wide age spectrum, ranging from Neoarchean to Rupelian (from 2712 ± 25 to 30 ± 1 Millions of years (Ma)). The age data show that in volcaniclastic sandstones there is evidence of ancient crystalline basements involved in Cadomian and Variscan orogenesis (ages from 2712 ± 25 Ma to ≈260 Ma), whereas the measured ages of 157 Ma testify the events of Pangea fragmentation and the ages between 78 and 67 Ma are related to subduction metamorphism connected to the Alpine orogenesis. Fifty percent of the estimated detrital zircon ages show a mean concordant age of 33 ± 1 Ma, they have been measured on idiomorphic crystals with undisturbed magmatic oscillatory zoning. These data reveal the true sedimentation age of Tufiti di Tusa sandstones at least at the sampled levels, coeval with that recorded in other Rupelian volcaniclastic successions outcropping in the Northern Apennines and in the Western Alps (e.g., Val d’Aveto-Petrignacola Formation, Ranzano Formation and Taveyannaz Sandstone). These data represent preliminary suggestions of the sedimentation age of the Tufiti di Tusa Formation and Rupelian paleogeography in the Western Mediterranean area. During Priabonian-Rupelian times, the volcanic calc-alkaline detritus linked to a widespread syn-sedimentary igneous activity on the hinterland terranes of the foredeep basins in the Apennine-Maghrebian orogen extended from north to south in the Western-Central Mediterranean area
Building an orogen: Review of U-Pb zircon ages from the calabria-peloritani terrane to constrain the timing of the southern variscan belt
Full text linkThe application of zircon dating to the reconstruction of orogenic systems is invaluable since time constraints of the geological evolution of orogens are crucial for the proposal of geodynamic and paleogeographic models. Zircon is one of the most promising accessory minerals in geochronology of crystalline basements because of its high-closure temperature. Moreover, U-Pb data of relict and recrystallized grains indicate the maximum sedimentation age as well as the timing of metamorphism in metasediments. In addition, the U-Pb ages of magmatic zircons constrain the timescale of magmatism. The Calabria-Peloritani terrane (CPT) represents a key area in the Southern Variscan Belt, whose reconstruction is still unresolved. Therefore, a review of literature zircon age data accompanied with new data from six samples of orthogneisses, paragneisses, amphibolites, and actinolite schists, helps to constrain the evolution of this Cadomian fragment, affected by metamorphic and magmatic Variscan events. A revisiting of the timing of the geological events from Paleo-proterozoic to Permian is revealed by comparing the internal textures of zircons and their U-Pb age clusters. The detected age peaks at 2500 Ma, 1600 Ma, and 1000 Ma in the CPT were related to a provenance from West and East Gondwana realms. A sedimentation age around 630 Ma emerges for the middle-deep crust terranes of the CPT, affected by Ediacaran (579- 540 Ma) intrusions, accompanied by metamorphism dated at 556-509 Ma in the host metasediments. In the following, during Ordovician-Silurian extensional tectonics, the former Cadomian terranes were at least locally affected by fluid-assisted metamorphism (around 450 Ma) whereas the upper extensional basins that formed, were infilled by sediments along with interspersed volcanic to subvolcanic products. All these pre-Silurian terranes were involved in the subduction process of the Palaeotethys-Gondwana margin beneath Laurussia. The compressive phase began around 347 Ma, with under-thrusting of the formerly Gondwana substrate that was subjected to middle-high grade metamorphism, while the Ordovician-Silurian sediments were scraped off along the front of the Southern Variscan Belt and affected by low-grade metamorphism. Decompression of the whole Variscan orogenic system started around 320 Ma, together with uplifting of the chain and emplacement of widespread granitic intrusions which ended around 280 Ma and completed the Variscan orogenic cycle in the CPT
Peptide analogues of a subdominant epitope expressed in EBV-associated tumors: synthesis and immunological activity
No full textH-Cys-Leu-Gly-Gly-Leu-Leu-Thr-Met-Val-OH (CLG) peptide is an EBV subdominant epitope that represents the target of HLA-A2 restricted CTL responses. The CLG peptide has low affinity for HLA-A2 and does not produce stable complexes, both factors that determine weak CTL responses. In contrast, the [Tyr(1), Ala(3)]CLG (YLA) analogue showed high affinity for HLA-A2 molecules and efficiently stimulated CLG-specific CTL precursors. Nevertheless, this modified epitope showed low enzymatic stability. To further improve the immunotherapeutical potential of this "improved epitope", we have synthesized and tested YLA analogues containing different modifications next to the scissile peptide bond. Among the analogues we found three peptides, with higher enzymatic resistance, that efficiently stimulate CTL responses. These peptides may be used for EBV-specific immunotherapies
Consultancy and surveillance of post-immunization adverse events in the Veneto region of Italy for 1992-2008
No full textPrevention and control of adverse events following immunization (AEFI) are fundamental activities of successful immunisation programs. AEFI reporting, investigation and analysis, integrated by consultancy for subjects needing a specialized evaluation, represent an ideal model for vaccine safety surveillance. In the Veneto Region of Italy the Green Channel Centre has been created by the local Public Health authority, to offer a consultancy activity for vaccinations at risk of adverse events and to ensure an efficient AEFI surveillance system with regular feedback data for vaccine personnel. This report updates the overall activity provided by the Green Channel between 1992 and 2008, concerning consultations for previous AEFI and contraindications to vaccinations and analysis of AEFI reports. After 1280 consultancy cases, 998 (78%) subjects were found eligible for vaccination, with personalized precautions suggested in 42% of cases. Of a total of 724 patients actually vaccinated as per the Green Channel instructions, only 55 subjects (7.6%) reported mild symptoms and one (0.3%) a moderate allergic reaction. Since 1993, a total of 5,006 AEFI reports have been collected and evaluated by the Green Channel against more than 20 millions of vaccine doses administered with an estimate mean AEFI rate of 2.3 x 10.000 doses per year. The majority of them (94%) were found in causal relationship with vaccines; of these, 267 reports (5,6% - 0.1/10,000 doses) were serious and 9 of these subjects, affected by a neurological event, were not recovered or were still on therapy at follow up. This regional activity has proven efficacious in evaluating and managing individual cases at potential risk of AEFI and integrating the national passive surveillance system
Cytotoxic T lymphocyte epitope analogues containing cis- or trans-4-aminocyclohexanecarboxylic acid residues
No full textIn order to improve the immunotherapeutical potential of H-Cys-Leu-Gly-Gly-Leu-Leu-Thr-Met-Val-OH (CLG) peptide, an Epstein-Barr virus (EBV) subdominant epitope derived from the membrane protein LMP2, we have synthesized and tested CLG analogues containing cis- and/or trans-4-aminocyclohexanecarboxylic acid (ACCA) replacing Gly-Gly and/or Thr-Met dipeptide units. All pseudopeptides were tested for metabolic stability and for their capacity to bind HLA-A2 molecules and to sensitize target cells to lysis. All new compounds exhibited higher enzymatic resistance compared to the original CLG and some trans-ACCA-derivatives were able to associate HLA-A2 and to efficiently stimulate CTL responses directed against the CLG natural epitope
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