1,913 research outputs found
The UV window on counter rotating ETGs: insight from SPH simulations with chemo-photometric implementation
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
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
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
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
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
Experimental and computational fluid dynamic studies of mixing for complex oral health products
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
Exploiting quantum parallelism of entanglement for a complete experimental quantum characterization of a single qubit device
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
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