Multiscale permutation entropy analysis of laser beam wandering in isotropic turbulence

We have experimentally quantified the temporal structural diversity from the coordinate fluctuations of a laser beam propagating through isotropic optical turbulence. The main focus here is on the characterization of the long-range correlations in the wandering of a thin Gaussian laser beam over a screen after propagating through a turbulent medium. To fulfill this goal, a laboratory-controlled experiment was conducted in which coordinate fluctuations of the laser beam were recorded at a sufficiently high sampling rate for a wide range of turbulent conditions. Horizontal and vertical displacements of the laser beam centroid were subsequently analyzed by implementing the symbolic technique based on ordinal patterns to estimate the well-known permutation entropy. We show that the permutation entropy estimations at multiple time scales evidence an interplay between different dynamical behaviors. More specifically, a crossover between two different scaling regimes is observed. We confirm a transition from an integrated stochastic process contaminated with electronic noise to a fractional Brownian motion with a Hurst exponent H = 5/6 as the sampling time increases. Besides, we are able to quantify, from the estimated entropy, the amount of electronic noise as a function of the turbulence strength. We have also demonstrated that these experimental observations are in very good agreement with numerical simulations of noisy fractional Brownian motions with a well-defined crossover between two different scaling regimes.Comment: 8 pages, 6 figure

Biomimicking Extracellular Vesicles with Fully Artificial Ones: A Rational Design of EV-BIOMIMETICS toward Effective Theranostic Tools in Nanomedicine

Extracellular Vesicles (EVs) are the protagonists in cell communication and membrane trafficking, being responsible for the delivery of innumerable biomolecules and signaling moieties. At the moment, they are of paramount interest to researchers, as they naturally show incredibly high efficiency and specificity in delivering their cargo. For these reasons, EVs are employed or inspire the development of nanosized therapeutic delivery systems. In this Perspective, we propose an innovative strategy for the rational design of EV-mimicking vesicles (EV-biomimetics) for theranostic scopes. We first report on the current state-of-the-art use of EVs and their byproducts, such as surface-engineered EVs and EV-hybrids, having an artificial cargo (drug molecule, genetic content, nanoparticles, or dye incorporated in their lumen). Thereafter, we report on the new emerging field of EV-mimicking vesicles for theranostic scopes. We introduce an approach to prepare new, fully artificial EV-biomimetics, with particular attention to maintaining the natural reference lipidic composition. We overview those studies investigating natural EV membranes and the possible strategies to identify key proteins involved in site-selective natural homing, typical of EVs, and their cargo transfer to recipient cells. We propose the use also of molecular simulations, in particular of machine learning models, to approach the problem of lipid organization and self-assembly in natural EVs. We also discuss the beneficial feedback that could emerge combining the experimental tests with atomistic and molecular simulations when designing an EV-biomimetics lipid bilayer. The expectations from both research and industrial fields on fully artificial EV-biomimetics, having the same key functions of natural ones plus new diagnostic or therapeutic functions, could be enormous, as they can greatly expand the nanomedicine applications and guarantee on-demand and scalable production, off-the-shelf storage, high reproducibility of morphological and functional properties, and compliance with regulatory standards

Quantum Lie algebras associated to Uq(gln)U_q(gl_n) and Uq(sln)U_q(sl_n)

Quantum Lie algebras \qlie{g} are non-associative algebras which are embedded into the quantized enveloping algebras $U_q(g)$ of Drinfeld and Jimbo in the same way as ordinary Lie algebras are embedded into their enveloping algebras. The quantum Lie product on \qlie{g} is induced by the quantum adjoint action of $U_q(g)$. We construct the quantum Lie algebras associated to $U_q(gl_n)$ and $U_q(sl_n)$. We determine the structure constants and the quantum root systems, which are now functions of the quantum parameter $q$. They exhibit an interesting duality symmetry under $q\leftrightarrow 1/q$.Comment: Latex 9 page

Imunidade de pinhão-manso a Heterodera glycines.

Made available in DSpace on 2011-04-09T19:06:13Z (GMT). No. of bitstreams: 1 NematologiaBrasileiraAsmus.pdf: 102890 bytes, checksum: e855b3ede080f25b6ea8cb47a2efa1bb (MD5) Previous issue date: 2011-01-20201

Universal interface width distributions at the depinning threshold

We compute the probability distribution of the interface width at the depinning threshold, using recent powerful algorithms. It confirms the universality classes found previously. In all cases, the distribution is surprisingly well approximated by a generalized Gaussian theory of independant modes which decay with a characteristic propagator G(q)=1/q^(d+2 zeta); zeta, the roughness exponent, is computed independently. A functional renormalization analysis explains this result and allows to compute the small deviations, i.e. a universal kurtosis ratio, in agreement with numerics. We stress the importance of the Gaussian theory to interpret numerical data and experiments.Comment: 4 pages revtex4. See also the following article cond-mat/030146

Roughness at the depinning threshold for a long-range elastic string

In this paper, we compute the roughness exponent zeta of a long-range elastic string, at the depinning threshold, in a random medium with high precision, using a numerical method which exploits the analytic structure of the problem (`no-passing' theorem), but avoids direct simulation of the evolution equations. This roughness exponent has recently been studied by simulations, functional renormalization group calculations, and by experiments (fracture of solids, liquid meniscus in 4He). Our result zeta = 0.390 +/- 0.002 is significantly larger than what was stated in previous simulations, which were consistent with a one-loop renormalization group calculation. The data are furthermore incompatible with the experimental results for crack propagation in solids and for a 4He contact line on a rough substrate. This implies that the experiments cannot be described by pure harmonic long-range elasticity in the quasi-static limit.Comment: 4 pages, 3 figure

Langerhans´cell histiocytosis

La histiocitosis de células de Langerhans (HCL), anteriormente conocida como histiocitosis X, es una enfermedad poco frecuente caracterizada por la acumulación y proliferación de histiocitos, eosinófilos y células de Langerhans, con inclusión de gránulos de Birbeck detectables por microscopia electrónica, afectando órganos y sistemas de forma aislada o múltiple. El diagnóstico se realiza mediante biopsia de la lesión y la confirmación de la presencia de CD1a y/o CD207 en la misma. Las distintas formas de presentación producen distinto enfoque terapéutico y pronóstico, desde formas benignas, autolimitadas, con resolución espontánea hasta otras de curso tórpido o maligno.Langerhans’ cell histiocytosis (LCH), previously known as histiocytosis X, is a rare disease. It is characterized by the accumulation and proliferation of histiocytes, eosinophils and Langerhans’ cells with Birbeck granules detected by electron microscopy. It involves single organs or systems or can present as a multisystem disease. The diagnosis is made by biopsy of the lesion and confirming the presence of CD1a and / or CD207 on it. The clinical presentation may vary widely, ranging from benign self-limiting types with spontaneous regression to slowly progressive malignant disease.Fil: Casanovas, A.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Elena, G.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Rosso, Diego. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Use of Perylene Diimides in Synthetic Photochemistry

Perylene diimides (PDIs) are valuable organic chromophores that stand out for their outstanding optical and redox properties. Owing to these features, PDIs have emerged as prominent dyes capable of acting as photocatalysts for numerous relevant organic transformations. This Minireview highlights the recent advances in the application of PDIs in organic photocatalysis. The various mechanistic pathways of the photo-reduction reaction of aryl halides, recently proposed in independent studies, are discussed with an eye to unsolved challenges and forward-looking opportunities regarding the use of PDIs within this field