308 research outputs found
Intertext and postmodern space in the work of Pier Vittorio Tondelli
This thesis deals with the work of Pier Vittorio Tondelli (1955-91) and concerns the way in which the greater permeability of cultural borders and speed of information exchanges affects the production of contemporary fiction and makes national literatures open to permeation by other cultures. Tondelli provides in this respect an interesting case study since his works display a particular bent for hybridization, both of language and content. This thesis examines his literary and non-literary production, paying particular attention to intertextual and intercultural relations and to questions of cultural and virtual space. In contrast to the existing critical tradition on Tondelli it devotes equal attention to style and content. Fifteen years after Tondelli's death it is time for a different approach to his work in particular it is important to read it through an intertextual perspective. Through a close textual analysis of his works, regarded as a complex patchwork of references (including film and music as well as literature), I intend to determine a typology of the different relations he established with his models in different texts and at different stages of his career. The contextualization of these relations and the analysis of certain recurrent narrative themes, such as separation and the journey, offers a new perspective on Tondelli's works. The thesis is divided into four chapters. The first introduces two theories postmodernism and intertextuality that are central in the analysis of Tondelli's fiction. It also presents the literary production of Alberto Arbasino as a major influence on his works. The other three chapters focus on Tondelli's principal works of fiction
Energy minimizing maps with prescribed singularities and Gilbert-Steiner optimal networks
We investigate the relation between energy minimizing maps valued into spheres having topological singularities at given points and optimal networks connecting them (e.g., Steiner trees, Gilbert-Steiner irrigation networks). We show the equivalence of the corresponding variational problems, interpreting in particular the branched optimal transport problem as a homological Plateau problem for rectifiable currents with values in a suitable normed group. This generalizes the pioneering work by Brezis, Coron and Lieb [10]
Configuration interaction wave functions: A seniority number approach
This work deals with the configuration interaction method when an N-electron Hamiltonian is projected on Slater determinants which are classified according to their seniority number values. We study the spin features of the wave functions and the size of the matrices required to formulate states of any spin symmetry within this treatment. Correlation energies associated with the wave functions arising from the seniority-based configuration interaction procedure are determined for three types of molecular orbital basis: canonical molecular orbitals, natural orbitals, and the orbitals resulting from minimizing the expectation value of the N-electron seniority number operator. The performance of these bases is analyzed by means of numerical results obtained from selected N-electron systems of several spin symmetries. The comparison of the results highlights the efficiency of the molecular orbital basis which minimizes the mean value of the seniority number for a state, yielding energy values closer to those provided by the full configuration interaction procedure.Fil: Alcoba, Diego Ricardo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FĂsica de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de FĂsica; ArgentinaFil: Torre, Alicia. Universidad del Pais Vasco; EspañaFil: Lain, Luis . Universidad del Pais Vasco; EspañaFil: Massaccesi, Gustavo Ernesto. Universidad de Buenos Aires. Ciclo BĂĄsico ComĂșn; ArgentinaFil: Oña, Ofelia Beatriz. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico la Plata. Instituto de Investigaciones FisicoquĂmicas TeĂłricas y Aplicadas; Argentin
Combined DC-Link Fed Parallel-VSI-Based DSTATCOM for Power Quality Improvement of a Solar DG Integrated System
In present day power systems, Power Quality (PQ) issues are causing great concern owing to the increased use of power electronic controlled drives and fluctuating and other non-linear loads. This problem is further aggravated by a steady increase in the integration of renewable energy-based Distribution Generation (DG), employing power electronic converters to distribution systems. Custom power devices with suitable control strategies provide an effective solution to these power quality issues. In this work, a typical three-phase distribution system supplying non-linear load and with DG integration is considered. A shunt connected DSTATCOM at PCC of the system is employed to mitigate power quality concerns. Initially, a parallel-VSI based DSTATCOM configuration, employing individual DC-Link and working basically on the principle of current sharing, has been proposed. The analysis is carried out for variable load conditions for PQ enhancement making use of a more effective control theory viz. Instantaneous Real-Reactive Power (IRP) theory for the generation of suitable switching patterns to the individual VSIs of the parallel DSTATCOM. Further, an improvement over the above configuration viz. combined/common DC-Link-fed parallel DSTATCOM is proposed. This configuration has the advantages of minimized sensing elements, reliable operation and low-cost compensation. A similar analysis is carried out for PQ improvement, making use of the same IRP theory with some modifications (known as MIRP theory). The effectiveness of this configuration is established from the simulation results. In all the above cases, the analyses are carried out using MATLAB/Simulink platform and the simulation results are presented in detail. Thus, the proposed parallel VSIs-based DSTATCOM configurations employing suitable control strategies provide effective solutions for power quality issues under varying load conditions in conventional distribution systems
All functions are (locally) -harmonic (up to a small error) - and applications
The classical and the fractional Laplacians exhibit a number of similarities,
but also some rather striking, and sometimes surprising, structural
differences.
A quite important example of these differences is that any function
(regardless of its shape) can be locally approximated by functions with locally
vanishing fractional Laplacian, as it was recently proved by Serena Dipierro,
Ovidiu Savin and myself.
This informal note is an exposition of this result and of some of its
consequences
Seniority number in spin-adapted spaces and compactness of configuration interaction wave functions
This work extends the concept of seniority number, which has been widely used for classifying N-electron Slater determinants, to wave functions of N electrons and spin S, as well as to N-electron spin-adapted Hilbert spaces. We propose a spin-free formulation of the seniority number operator and perform a study on the behavior of the expectation values of this operator under transformations of the molecular basis sets. This study leads to propose a quantitative evaluation for the convergence of the expansions of the wave functions in terms of Slater determinants. The non-invariant character of the seniority number operator expectation value of a wave function with respect to a unitary transformation of the molecular orbital basis set, allows us to search for a change of basis which minimizes that expectation value. The results found in the description of wave functions of selected atoms and molecules show that the expansions expressed in these bases exhibit a more rapid convergence than those formulated in the canonical molecular orbital bases and even in the natural orbital ones.Fil: Alcoba, Diego Ricardo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FĂsica de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de FĂsica; ArgentinaFil: Torre, Alicia. Universidad del PaĂs Vasco. Facultad de Ciencia y TecnologĂa. Departamento de QuĂmica FĂsica; España;Fil: Lain, Luis. Universidad del PaĂs Vasco. Facultad de Ciencia y TecnologĂa. Departamento de QuĂmica FĂsica; España;Fil: Massaccesi, Gustavo Ernesto. Universidad de Buenos Aires. Ciclo BĂĄsico ComĂșn; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de MatemĂĄtica; ArgentinaFil: Oña, Ofelia Beatriz. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico la Plata. Instituto de Investigaciones FisicoquĂmicas TeĂłricas y Aplicadas; Argentin
Drawing information from the ground state G-particle-hole matrix to study electronic excited states
Very recently, we have shown the suitability to combine the G-particle-hole Hypervirial (GHV) equation method (Alcoba et al. in Int J Quantum Chem 109:3178, 2009) with the Hermitian Operator (HO) method (Bouten et al. in Nucl Phys A 202:127, 1973) for computing various energy differences of an electronic system spectrum (Valdemoro et al. in J Math Chem 50:492, 2012). The purpose of this paper is to extend our preliminary studies by applying the combined GHV-HO method to obtain the set of ground and low-lying excited states potential energy curves of several selected electronic systems. The calculations confirm the reliability of the method.Instituto de Investigaciones FisicoquĂmicas TeĂłricas y Aplicada
Increased Expression of ÎČ-N-Acetylglucosaminidase in Erythrocytes From Individuals With Pre-diabetes and Diabetes
Plasma deconvolution identifies broadly neutralizing antibodies associated with hepatitis C virus clearance
A vaccine for hepatitis C virus (HCV) is urgently needed. Development of broadly neutralizing plasma antibodies during acute infection is associated with HCV clearance, but the viral epitopes of these plasma antibodies are unknown. Identifying these epitopes could define the specificity and function of neutralizing antibodies (NAbs) that should be induced by a vaccine. Here, we present the development and application of a high-throughput method that deconvolutes polyclonal anti-HCV NAbs in plasma, delineating the epitope specificities of anti-HCV NAbs in acute-infection plasma of 44 humans with subsequent clearance or persistence of HCV. Remarkably, we identified multiple broadly neutralizing antibody combinations that were associated with greater plasma neutralizing breadth and with HCV clearance. These studies have the potential to inform new strategies for vaccine development by identifying broadly neutralizing antibody combinations in plasma associated with the natural clearance of HCV, while also providing a high-throughput assay that could identify these responses after vaccination trials
Presepsin: A potential biomarker of PJI? A comparative analysis with known and new infection biomarkers
There is still no "gold standard" for the diagnosis and prognosis of post-operative periprosthetic joint infection (PJI). Among serum biomarkers, an emerging molecule is presepsin, the soluble fraction of CD14, recently described in other settings as a powerful diagnostic tool to detect sepsis at different degrees of severity.
The aim of this study was to investigate the diagnostic and prognostic value of presepsin in PJI. A total of 30 patients with PJI and 30 patients without PJI were enrolled. Presepsin, C-reactive protein (CRP), serum interleukin (IL)-6, triggering receptor expressed on myeloid cells 1 (TREM-1), CCL2, matrix metalloproteinase 9 (MMP-9), CD163, osteopontin (OPN), and toll-like receptor 2 (TLR2) were measured at different times after surgery. Receiver operating characteristic (ROC) curves and area under the curve (AUC) were analyzed for each biomarker. Presepsin showed greater diagnostic value than CRP and IL-6; CD163, TREM-1, and MMP-9 had very low diagnostic potential. Presepsin, OPN, CCL2, suPAR, and TLR2 all decreased significantly with increasing time of recovery after surgery in PJI patients.
Presepsin can be considered a useful tool for the diagnosis and clinical monitoring of PJI and can be backed by a panel of new inflammatory markers involved in monocyte-/macrophage-mediated inflammatory responses, such as OPN, CCL2, TLR2, and suPAR
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