675 research outputs found
Multimedia fiction: theory and practice of Décio Pignatari s literary narrative
No full textA tese tem por temas a teoria e a prática da prosa ficcional em Décio Pignatari.
Décadas de trabalho em diferentes pólos da comunicação publicou ensaios e deu aulas de teoria da informação, atuou como articulista na imprensa, foi o primeiro intelectual a escrever seriamente sobre a TV no Brasil, traduziu Marshall McLuhan, fez publicidade e cinema transformaram Pignatari num criador multimídia. É essa característica que marca sua obra voltada para a ficção.
Pautada pelo uso de múltiplos recursos, verbais e não-verbais, literários e de mídias diversas, as narrativas de Décio Pignatari representam extensões de sua prosética como ele chama o seu pensamento sobre a prosa ficcional e vice-versa
Enquanto a plataforma teórica pignatariana para a ficção estabeleceu-se especialmente por meio de cursos, ensaios e artigos, sua produção em termos de narrativa literária deu origem aos seguintes títulos, que serão aqui analisados: 1)O rosto da memória, contos; 2)Panteros, romance; 3) Cléris und Lotta , que integra a antologia 21 Histórias de amor, mas que já aparecera, sem título, no corpo do prefácio de Cultura pós-nacionalista, coletânea de textos de não-ficção; e 4)Céu de lona, peça teatral.
Para estudar prosa ficcional de Décio Pignatari, a tese vale-se sobretudo da própria prosética que tem por base a semiótica de Charles Sanders Peirce. De acordo com Pignatari, a ficção, notadamente a que surge a partir de Ulisses (1922), de James Joyce, se apóia na secundidade peirceana, que se projeta sobre a terceiridade como um presente suspenso , ponto de encontro dos demais tempos, do máximo de gêneros e de discursos de distintos meios de comunicação.
Esta é a proposta do autor para sua prosa ficcional, espelho da prosética , que dela também se alimenta, conforme pretendemos demonstrar.
Ressalte-se que Décio Pignatari alcança pela primeira vez essa condição acadêmicaThe dissertation subject is the theory and practice of Décio Pignatari s fictional prose.
Decades of work in various fields of communication he has published essays, has taught information theory, has written to the press and was the first intellectual to write in-depth pieces on TV in Brazil, he has translated Marshall McLuhan, has produced advertising pieces, and cinema have made of Pignatari a multimedia creator. This approach also defines his fictional production.
Characterized by the usage of multiple resources, both verbal and non-verbal, literary and of various media, Décio Pignatari s narratives represent extensions of his prosética as he calls his thinking on the fictional prose and vice versa.
While the pignatarian theoretical platform catering his fiction has been established especially through courses, articles, and essays, his narrative literary production has originated the following works: 1) O rosto da memória [The face of memory], stories; 2) Panteros [Pantheros], novel; 3) Cléris und Lotta [Cléris and Lotta], narrative that integrates the anthology 21 Histórias de Amor [21 Love Stories], which had already appeared, untitled, in the foreword to Cultura pós-nacionalista [Post-Nationalist Culture], collected non-fictional texts; and 4) Céu de lona [Tent sky], a play.
To survey Décio Pignatari s fictional prose, the dissertation counts mostly on the very prosética which is based on Charles Sanders Peirce s semiotic. According to Pignatari, fiction, notably the one produced since the release of Ulysses (1922), by James Joyce, is dominated by Peirce s Secondness, which projects itself on Thirdness as a suspended gift, a meeting point of the other tenses, the maximum of genders and of distinct discourses of the media.
This is the author s purpose for his fictional prose, a prosética mirror, that also feeds itself, as we intend to demonstrate.
This is the first "critical study" of Décio Pignatari s fictional prose and his prosétic
The Cold and Hot CNO Cycles
No full textNew experimental methods and techniques, combined with the development of new theoretical tools, have opened new avenues to explore nuclear reactions of significance for nucleosynthesis at or near the actual temperatures of stellar burning. In particular, many reactions of the cold and hot CNO cycles have been investigated in recent years to provide a complete understanding of this critical hydrogen-burning mechanism in stars and stellar explosions. This has led to new interpretations of or new signatures for a number of critical hydrogen-burning environments and events. This article provides a summary of the most recent discoveries and results associated with CNO reactions, and it identifies existing shortcomings in the data as well as needs and opportunities for additional future experiments
The Complex Behaviour of s-Process Element Abundances at Young Ages
Get PDFOpen clusters appear as simple objects in many respects, with a high degree of homogeneity in their (initial) chemical composition, and the typical solar-scaled abundance pattern that they exhibit for the majority of the chemical species. The striking singularity is represented by heavy elements produced from the slow process of the neutron-capture reactions. In particular, young open clusters (ages less than a few hundred Myr) give rise to the so-called barium puzzle: that is an extreme enhancement in their [Be/Fe] ratios, up to a factor of four of the solar value, which is not followed by other nearby s-process elements (e.g., lanthanum and cerium). The definite explanation for such a peculiar trend is still wanting, as many different solutions have been envisaged. We review the status of this field and present our new results on young open clusters and the pre-main sequence star RZ Piscium
Convective–reactive nucleosynthesis of K, Sc, Cl and p-process isotopes in O–C shell mergers
Get PDF© 2017 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. We address the deficiency of odd-Z elements P, Cl, K and Sc in Galactic chemical evolution models through an investigation of the nucleosynthesis of interacting convective O and C shells in massive stars. 3D hydrodynamic simulations of O-shell convection with moderate C-ingestion rates show no dramatic deviation from spherical symmetry. We derive a spherically averaged diffusion coefficient for 1D nucleosynthesis simulations, which show that such convective-reactive ingestion events can be a production site for P, Cl, K and Sc. An entrainment rate of 10-3M⊙s-1features overproduction factors OPs≈ 7. Full O-C shell mergers in our 1D stellar evolution massive star models have overproduction factors OPm> 1 dex but for such cases 3D hydrodynamic simulations suggest deviations from spherical symmetry. γ - process species can be produced with overproduction factors of OPm> 1 dex, for example, for130, 132Ba. Using the uncertain prediction of the 15M⊙, Z = 0.02 massive star model (OPm≈ 15) as representative for merger or entrainment convective-reactive events involving O- and C-burning shells, and assume that such events occur in more than 50 per cent of all stars, our chemical evolution models reproduce the observed Galactic trends of the odd-Z elements
Corrigendum to FGF23-regulated production of fetuin-A (AHSG) in osteocytes [Bone 83 (2016) 35-47]
No full textRefers to: D. Mattinzoli, M.P. Rastaldi, M. Ikehata, S. Armelloni, C. Pignatari, L.A. Giardino, M. Li, C.M. Alfieri, A. Regalia, D. Riccardi, P. Messa
FGF23-regulated production of Fetuin-A (AHSG) in osteocytes
Bone, Volume 83, February 2016, Pages 35-4
On the internal pollution mechanisms in the globular cluster NGC 6121 (M4) : heavy-element abundances and AGB models
Get PDFGlobular clusters display significant variations in their light-element content, pointing to the existence of a second stellar generation formed from the ejecta of an earlier generation. The nature of these internal polluters is still a matter of debate: the two most popular scenarios indicate intermediate-mass asymptotic giant branch (IM-AGB) stars and fast rotating massive stars. Abundances determination for some key elements can help distinguish between these competitor candidates. We present in this paper Y abundances for a sample of 103 red giant branch stars in NGC 6121. Within measurement errors, we find that the [Y/Fe] is constant in this cluster contrary to a recent suggestion. For a subsample of six stars we also find [Rb/Fe] to be constant, consistent with previous studies showing no variation in other s-process elements. We also present a new set of stellar yields for IM-AGB stellar models of 5 and 6M⊙, including heavy element s-process abundances. The uncertainties on the mass-loss rate, the mixing length parameter and the nuclear reaction rates have a major impact on the stellar abundances. Within the IM-AGB pollution scenario, the constant abundance of heavy elements inside the cluster requires a marginal s-process efficiency in IM-AGB stars. Such a constrain could still be satisfied by the present models assuming a stronger mass-loss rate. The uncertainties mentioned above are limiting the predictive power of IM-AGB models. For these reasons, at the moment we are not able to clearly rule out their role as main polluters of the second population stars in globular clusters. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society
Impact of the uncertainty in alpha-captures on Ne-22 on the weak s-process in massive stars
No full textMassive stars at solar metallicity contribute to the production of heavy elements with atomic masses between A = 60 and A = 90 via the so-called weak s-process (which takes place during core He and shell C burning phases). Furthermore, recent studies have shown that rotation boosts the s-process production in massive stars at low metallicities, with a production that may reach the barium neutron-magic peak. These results are very sensitive to neutron source and neutron poison reaction rates. For the weak s-process, the main neutron source is the reaction 22Ne(α,n)25Mg, which is in competition with 22Ne(α,γ)26Mg. The uncertainty of both rates strongly affects the nucleosynthesis predictions from stellar model calculations. In this study, we investigate the impact of the uncertainty in α-captures on 22Ne on the s-process nucleosynthesis in massive stars both at solar and at very low metallicity. For this purpose, we post-process, with the Nugrid mppnp code, non-rotating and rotating evolutionary models 25M⊙ stars at two different metallicities: Z = Z⊙ and Z = 10-5Z ⊙, respectively. Our results show that uncertainty of 22Ne(α,n)25Mg and 22Ne(α,γ)26Mg rates have a significant impact on the final elemental production especially for metal poor rotating models. Beside uncertainties in the neutron source reactions, for fast rotating massive stars at low metallicity we revisit the impact of the neutron poisoning effect by the reaction chain 16O(n,γ)17O(α, γ)21Ne, in competition with the 17O(α,n)20Ne, recycling the neutrons captured by 16O
Higher mitochondrial dna content in human IUGR placenta
No full textIUGR has been associated to a specific placental phenotype with reduced uptake of specific nutrients. Recently, it has been hypothesized that IUGR may be determined during early gestation. This period is characterized by decidual trophoblast invasion and by intense cellular growth, replication and differentiation. Since a huge energetic availability is required during gestation, we hypothesize that mitochondria may play a crucial role in this process being the main energetic producer in the cell. The aim of this study was to investigate the role of mitochondria in IUGR pathogenesis, evaluating the number of mitochondrial DNA copies (mtDNA) in IUGR placentae compared to controls. Placental samples were collected from 50 singleton pregnancies at the time of elective caesarean section. Twenty-six pregnancies were controls with normal intrauterine growth (AGA) and 24 were studied after the in utero diagnosis of IUGR. All samples were analyzed by real-time quantitative PCR and statistical analysis was performed by non-parametric tests. The median value of mitochondrial DNA content (IQR) in AGA and IUGR placentae was significantly different (455 and 698, respectively, p = 0.004). The cell types responsible for the difference observed is unknown and it is possible that changes observed in the proportion of cell types may influence this measurement. Moreover, a significant negative relationship was observed between mtDNA and umbilical venous pO2, with the highest levels detected in the most severe IUGR cases according to Doppler findings and to the presence of preeclampsia. These data suggest a relationship between the pathogenesis of IUGR and increased placental mtDNA copies. From our results we can speculate that increased mtDNA represents an adaptation of the metabolic placental mechanism to the calorie restriction of the fetus. Furthermore, we found that this rise was inversely related to oxygen tension in the umbilical vein. Although no specific pathogenetic role can be implied, mtDNA increases with hypoxia in placentas of IUGR
Inlists for paper: ALUMINIUM-26 FROM MASSIVE BINARY STARS II. ROTATING SINGLE STARS UP TO CORE-COLLAPSE AND THEIR IMPACT ON THE EARLY SOLAR SYSTEM
No full text================================================================================
Title: Aluminium-26 From Massive Binary Stars II: ROTATING SINGLE STARS UP TO CORE-COLLAPSE AND THEIR IMPACT ON THE EARLY SOLAR SYSTEM
Authors: Brinkman H.E., den Hartogh J. W., Doherty C.L., Pignatari M., Lugaro M.
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Description of contents: A .tar.gz package containing the input files for the
MESA simulations of massive (10 {<=} M*(solmass) {<=} 80) non-rotating and rotating,
single solar metallicity (Z=0.014). The files are in
the subdirectories /BlancoNR and /BlancoRotating. The nuclear network
used is also given, RadioSupernova.net
There are 4 basic files. The "inlist" file is the master inlist that MESA
reads when it starts. It reads the "_starjob", "_controls", and
"_pgstar" inlist files. For the single stars, subdirectory /Single, only one
set is needed. For both the rotating and the non-rotating set the run_star_extras.f is given as well.
System requirements: The MESA stellar evolution code. Version 10398 was used
for these input files.
Additional comments: See section 2 for full details of the simulations.
================================================================================This work is supported by the ERC via CoG-2016 RADIOSTAR (Grant Agreement 724560). We also acknowledge support from "ChETEC" COST Action(CA16117), supported by COST (European Cooperation in Science andTechnology). MP acknowledges significant support to NuGrid from STFC (through the University of Hull's Consolidated Grant ST/R000840/1), from the National Science Foundation (NSF, USA) under grant No. PHY-1430152 (JINA Center for the Evolution of the Elements) and from the "Lendulet-2014" Program of the Hungarian Academy of Sciences (Hungary). MP thanks for the support from the US IReNA Accelnet networ
Temperature-tuned Maxwell-Boltzmann neutron spectra for kT ranging from 30 up to 50keV for nuclear astrophysics studies
No full textThe need of neutron capture cross section measurements for astrophysics motivates present work, where calculations to generate stellar neutron spectra at different temperatures are performed. The accelerator-based 7Li(p,n)7Be reaction is used. Shaping the proton beam energy and the sample covering a specific solid angle, neutron activation for measuring stellar-averaged capture cross section can be done. High-quality Maxwell–Boltzmann neutron spectra are predicted. Assuming a general behavior of the neutron capture cross section a weighted fit of the spectrum to Maxwell–Boltzmann distributions is successfully introduced.G. Martín-Hernández acknowledges support from Laboratori Nazionali di Legnaro, Instituto Nazionale di Fisica Nucleare and M. Pignatari from Ambizione grant of the SNSF, NSF grants PHY 02-16783 and PHY 09-22648 (Joint Institute for Nuclear Astro physics, JINA), EU MIRG-CT-2006-046520, and Eurogenesis (MASCHE).Peer reviewe
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