1,876 research outputs found

    The UV window on counter rotating ETGs: insight from SPH simulations with chemo-photometric implementation

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    The Galaxy Evolution Explorer (GALEX) detected ultraviolet emission in about 50% of multi-spin early-type galaxies (ETGs), suggesting the occurrence of a recent rejuvenation episode connected to the formation of these kinematical features. With the aim at investigating the complex evolutionary scenario leading to the formation of counter rotating ETGs (CR-ETGs) we use our Smooth Particle Hydrodynamic (SPH) code with chemo-photometric implementation. We discuss here the UV evolutionary path of two CR-ETGs, NGC 3593 and NGC 5173, concurrently best fitting their global observed properties, i.e., morphology, dynamics, as well as their total B-band absolute magnitude and spectral energy distribution (SED) extended over three orders of magnitude in wavelength. These simulations correspond to our predictions about the target evolution which we follow in the color-magnitude diagram (CMD), near-UV (NUV) versus r-band absolute magnitude, as a powerful diagnostic tool to emphasize rejuvenation episodes.Comment: 7 pages, 3 figures, accepted for publication in ApS

    On Semiclassical Limits of String States

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    We explore the relation between classical and quantum states in both open and closed (super)strings discussing the relevance of coherent states as a semiclassical approximation. For the closed string sector a gauge-fixing of the residual world-sheet rigid translation symmetry of the light-cone gauge is needed for the construction to be possible. The circular target-space loop example is worked out explicitly.Comment: 12 page

    Patrón génico de fibrosis y apoptosis en nefropatía obstructiva experimental : : modulación por rosuvastatina

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    La nefropatía obstructiva puede ser un desorden renal complejo de tratar debido al severo cuadro inflamatorio, desbalance oxidativo, apoptosis y fibrosis. Estudios previos sostienen que rosuvastatina (Ros) podría tener utilidad como una opción terapéutica en enfermedades renales que cursarían con apoptosis y fibrosis. Objetivo: Evaluar los posibles efectos antiapoptóticos y antifibróticos de Ros durante la obstrucción ureteral unilateral en ratas neonatas. Materiales y Métodos: Ratas Wistar neonatas de 48 hs. de vida fueron intervenidas quirúrgicamente (grupo experimental) o no (grupo control). Ambos grupos fueron subdivididos en tratadas o no tratadas con Ros (10mg / kg por día) vía oral durante 14 días. Posteriormente se procedió a nefrectomizar y procesar las cortezas renales para determinar por RT-PCR las expresiones de genes: óxido nítrico sintasa inducible (iNOS), factor promotor génico de chaperonas (hsf1), proteína de shock térmico (hsp70), bax, bcL2, wt1, p53, snail, proteína morfogénica del hueso (bmp7), caderina E, factor transformador de crecimiento (tgf-β) y factor de necrosis tumoral (tnf-α). Resultados: La obstrucción ureteral unilateral neonatal indujo una marcada fibrosis y apoptosis, mientras que el tratamiento con Ros moduló el patrón de genes fibróticos y apoptóticos mediante disminución de la expresión de bmp7, caderina E, wt1, p53 y bcl2; además indujo una caída en la expresión de los genes profibróticos y proapoptóticos (bax, tnf-α y tgf-β). El análisis de los resultados presentados, permiten sugerir que la protección renal de rosuvastatina durante nefropatía obstructiva de ratas neonatas estaría asociado a la interacción entre hsp70 y la biodisponibilidad del óxido nítrico con el concomitante descenso en genes pro-apoptóticos.Fibrosis and apoptosis gene pattern in experimental obstructive nephropathy: Rosuvastatin modulation Obstructive nephropathy renal disorder can be complex to treat due to the severe apoptosis and fibrosis. Previous studies shown that rosuvastatin (Ros), may have potential utility as a therapeutic option in kidney diseases which lead to apoptosis and fibrosis. Objective: to evaluate the possible antifibrotic and antiapoptotic effects of Ros during experimental neonatal rats unilateral ureteral obstruction (UUO). Materials and Methods: Neonatal rats were surgically obstructed (experimental group) or not (control group), which were Ros treated or not (10 mg/kg per day) during 14 days. Subsequent nephrectomy and processing of the renal cortex to determinate by RT-PCR technique, genes expression of inducible nitric oxide synthase (iNOS), heat shock factor 1 (hsf1), heat shock protein 70 (hsp70), bax, bcl2, wt1, p53, snail, bone morphogenetic protein (bmp7), E-cadherin, transforming growth factor (tgf-β) and tumor necrosis factor (tnf-α). Results: neonatal UUO induced fibrosis and apoptosis, while Ros treatment modulated the fibrotic and apoptotic genes pattern and increased the bmp7, Ecadherin, wt1, p53 and bcl2 expression as well as decreased the profibrotic and proapoptotic genes expression (bax, tnf-α y tgf-β). Our results allow us to suggest that Ros renal protection during UUO is linked to hsp70 and nitric oxide bioavailability interaction, with concomitant decrease in pro apoptotic gene pattern.Fil: Mazzei, L.. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Área de FisiopatologíaFil: García, M.. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Área de FisiopatologíaFil: Manucha, W.. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Área de Fisiopatologí

    CFD-PBE coupled model for size-driven segregation in polydisperse granular flows

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    Mixtures of granular materials made of different-sized particles may segregate when subjected to vibration or shear rate and in the presence of a gravitational field. This leads to highly inhomogeneous mixtures, which are undesirable in many industrial processes. This work focuses on size-driven segregation in polydisperse mixtures. We described the evolution of the particle size distribution through a Population Balance Equation (PBE), which we solved numerically with the Direct Quadrature Method of Moments. To allow segregation and micromixing to occur, we closed the size-conditioned velocity of the particles with a segregation- mixing model. The PBE was then included in an Eulerian-Eulerian model and solved in a commercial Computational Fluid Dynamics (CFD) code. We used the model to study granular flows down inclined planes. The numerical results were then compared with those obtained from Discrete Element Method simulations. The CFD-PBE model predicts well segregation and micromixing in packed beds of polydisperse powders

    A multi-wavelength study of the evolution of Early-Type Galaxies in Groups: the ultraviolet view

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    ABRIDGED- The UV-optical color magnitude diagram (CMD) of rich galaxy groups is characterised by a well developed Red Sequence (RS), a Blue Cloud (BC) and the so-called Green Valley (GV). Loose, less evolved groups of galaxies likely not virialized yet may lack a well defined RS. This is actually explained in the framework of galaxy evolution. We are focussing on understanding galaxy migration towards the RS, checking for signatures of such a transition in their photometric and morphological properties. We report on the UV properties of a sample of ETGs galaxies inhabiting the RS. The analysis of their structures, as derived by fitting a Sersic law to their UV luminosity profiles, suggests the presence of an underlying disk. This is the hallmark of dissipation processes that still must have a role in the evolution of this class of galaxies. SPH simulations with chemo-photometric implementations able to match the global properties of our targets are used to derive their evolutionary paths through UV-optical CDM, providing some fundamental information such as the crossing time through the GV, which depends on their luminosity. The transition from the BC to the RS takes several Gyrs, being about 3-5 Gyr for the the brightest galaxies and more long for fainter ones, if it occurs. The photometric study of nearby galaxy structures in UV is seriously hampered by either the limited FoV of the cameras (e.g in HST) or by the low spatial resolution of the images (e.g in the GALEX). Current missions equipped with telescopes and cameras sensitive to UV wavelengths, such as Swift-UVOT and Astrosat-UVIT, provide a relatively large FoV and better resolution than the GALEX. More powerful UV instruments (size, resolution and FoV) are obviously bound to yield fundamental advances in the accuracy and depth of the surface photometry and in the characterisation of the galaxy environment.Comment: 12 pages, 6 figures: accepted for publication in Astrophysics & Space Science as contributions to the workshop: "UV astronomy, the needs and the means

    Exploiting quantum parallelism of entanglement for a complete experimental quantum characterization of a single qubit device

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    We present the first full experimental quantum tomographic characterization of a single-qubit device achieved with a single entangled input state. The entangled input state plays the role of all possible input states in quantum parallel on the tested device. The method can be trivially extended to any n-qubits device by just replicating the whole experimental setup n times.Comment: 4 pages in revtex4 with 4 eps figure

    Experimental and computational fluid dynamic studies of mixing for complex oral health products

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    Mixing high viscous non-Newtonian fluids is common in the consumer health industry. Sometimes this process is empirical and involves many pilot plants trials which are product specific. The first step to study the mixing process is to build on knowledge on the rheology of the fluids involved. In this research a systematic approach is used to validate the rheology of two liquids: glycerol and a gel formed by polyethylene glycol and carbopol. Initially, the constitutive equation is determined which relates the viscosity of the fluids with temperature, shear rate, and concentration. The key variable for the validation is the power required for mixing, which can be obtained both from CFD and experimentally using a stirred tank and impeller of well-defined geometries at different impeller speeds. A good agreement between the two values indicates a successful validation of the rheology and allows the CFD model to be used for the study of mixing in the complex vessel geometries and increased sizes encountered during scale up
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