Multiple Spatial Frequencies Pyramid WaveFront Sensing

A modification of the pyramid wavefront sensor is described. In this conceptually new class of devices, the perturbations are split at the level of the focal plane depending upon their spatial frequencies, and then measured separately. The aim of this approach is to increase the accuracy in the determination of some range of spatial frequency perturbations, or a certain classes of modes, disentangling them from the noise associated to the Poissonian fluctuations of the light coming from the perturbations outside of the range of interest or from the background in the pupil planes; the latter case specifically when the pyramid wavefront sensor is used with a large modulation. While the limits and the effectiveness of this approach should be further investigated, a number of variations on the concept are shown, including a generalization of the spatial filtering in the point-diffraction wavefront sensor. The simplest application, a generalization to the pyramid of the well-known spatially filtering in wavefront sensing, is showing promise as a significant limiting magnitude advance. Applications are further speculated in the area of extreme adaptive optics and when serving spectroscopic instrumentation where “light in the bucket” rather than Strehl performance is required

Ingot Laser Guide Stars Wavefront Sensing

We revisit one class of z-invariant WaveFront sensor where the LGS is fired aside of the telescope aperture. In this way there is a spatial dependence on the focal plane with respect to the height where the resonant scattering occurs. We revise the basic parameters involving the geometry and we propose various merit functions to define how much improvement can be attained by a z-invariant approach. We show that refractive approaches are not viable and we discuss several solutions involving reflective ones in what has been nicknamed "ingot wavefront sensor" discussing the degrees of freedom required to keep tracking and the basic recipe for the optical design.Comment: 6 pages, 4 figures, AO4ELT5 Conference Proceeding, 201

A Holographic Diffuser Generalised Optical Differentiation Wavefront Sensor

The wavefront sensors used today at the biggest World's telescopes have either a high dynamic range or a high sensitivity, and they are subject to a linear trade off between these two parameters. A new class of wavefront sensors, the Generalised Optical Differentiation Wavefront Sensors, has been devised, in a way not to undergo this linear trade off and to decouple the dynamic range from the sensitivity. This new class of WFSs is based on the light filtering in the focal plane from a dedicated amplitude filter, which is a hybrid between a linear filter, whose physical dimension is related to the dynamic range, and a step in the amplitude, whose size is related to the sensitivity. We propose here a possible technical implementation of this kind of WFS, making use of a simple holographic diffuser to diffract part of the light in a ring shape around the pin of a pyramid wavefront sensor. In this way, the undiffracted light reaches the pin of the pyramid, contributing to the high sensitivity regime of the WFS, while the diffused light is giving a sort of static modulation of the pyramid, allowing to have some signal even in high turbulence conditions. The holographic diffuser zeroth order efficiency is strictly related to the sensitivity of the WFS, while the diffusing angle of the diffracted light gives the amount of modulation and thus the dynamic range. By properly choosing these two parameters it is possible to build a WFS with high sensitivity and high dynamic range in a static fashion. Introducing dynamic parts in the setup allows to have a set of different diffuser that can be alternated in front of the pyramid, if the change in the seeing conditions requires it.Comment: 11 pages, 5 figure

Multiple spatial frequencies wavefront sensing

We describe the concept of splitting spatial frequency perturbations into some kind of pupil planes wavefront sensors. Further to the existing approach of dropping higher spatial frequency to suppress aliasing effects (the so-called spatial filtered Shack-Hartmann), we point out that spatial frequencies splitting and mixing of these in a proper manner, could be handled in order to exhibit some practical or fundamental advantages. In this framework we describe the idea behind such class of concepts and we derive the relationship useful to determine if, by which extent, and under what kind of merit function, these devices can overperform existing conventional sensors.Comment: 6 pages, 3 figures, in AO4ELT5 Proceeding

Prospects of Deep Field Surveys with Global-MCAO on an ELT

Several astronomical surveys aimed at the investigation of the extragalactic components were carried out in order to map systematically the universe and its constituents. An excellent level of detail is needed, and it is possible only using space telescopes or with the application of adaptive optics (AO) techniques for ground-based observatories. By simulating K-band observations of 6000 high-redshift galaxies in the Chandra Deep Field South region, we have already shown how an extremely large telescope can carry out photometric surveys successfully using the Global-MCAO, a natural guide stars based technique that allows the development of extragalactic research, otherwise impracticable without using laser guide stars. As the outcome of the analysis represents an impact science case for the new instruments on upcoming ground-based telescopes, here we show how the investigation of other observed deep fields could profit from such a technique. Further to an overview of the surveys suitable for the proposed approach, we show preliminary estimations both on geometrical (FoV and height) and purely AO perspectives (richness and homogeneity of guide stars in the area) for planned giant telescope.Comment: 8 pages, 6 figures, AO4ELT5 conferenc

Transcriptomic and genomic studies classify NKL54 as a histone deacetylase inhibitor with indirect influence on MEF2-dependent transcription

In leiomyosarcoma class IIa HDACs (histone deacetylases) bind MEF2 and convert these transcription factors into repressors to sustain proliferation. Disruption of this complex with small molecules should antagonize cancer growth. NKL54, a PAOA (pimeloylanilide o-aminoanilide) derivative, binds a hydrophobic groove of MEF2, which is used as a docking site by class IIa HDACs. However, NKL54 could also act as HDAC inhibitor (HDACI). Therefore, it is unclear which activity is predominant. Here, we show that NKL54 and similar derivatives are unable to release MEF2 from binding to class IIa HDACs. Comparative transcriptomic analysis classifies these molecules as HDACIs strongly related to SAHA/vorinostat. Low expressed genes are upregulated by HDACIs, while abundant genes are repressed. This transcriptional resetting correlates with a reorganization of H3K27 acetylation around the transcription start site (TSS). Among the upregulated genes there are several BH3-only family members, thus explaining the induction of apoptosis. Moreover, NKL54 triggers the upregulation of MEF2 and the downregulation of class IIa HDACs. NKL54 also increases the binding of MEF2D to promoters of genes that are upregulated after treatment. In summary, although NKL54 cannot outcompete MEF2 from binding to class IIa HDACs, it supports MEF2-dependent transcription through several actions, including potentiation of chromatin binding

Il link asma-obesità: aspetti patogenetici, clinico-funzionali e diagnostico-terapeutici

L’asma e l’obesità sono considerate un problema primario di salute pubblica dell’età infantile, che sta assumendo proporzioni globalmente “epidemiche”. Diversi studi epidemiologici hanno chiaramente evidenziato la presenza di un’associazione tra le due patologie. Tale complessa interazione patogenetica vede coinvolti fattori genetici, di sviluppo, di funzione polmonare, immunologici e comportamentali; alcuni di essi sono ad oggi ancora poco studiati e conosciuti. Per tale motivo, non è possibile identificare un meccanismo prevalente sugli altri che sia alla base della relazione causale tra le due patologie. Il crescente interesse scientifico nei confronti dell’associazione tra asma e obesità ha contribuito a delineare diversi fenotipi di patologia presenti nelle varie epoche della vita. La caratterizzazione clinica dei soggetti asmatici obesi è presupposto fondamentale per identificare terapie mirate a raggiungere il controllo dell’asma e contemporaneamente a ridurre il peso del soggetto prevenendo le complicanze legate all’obesità

Preliminar study of the effects of gamma radiations on human red blood cells

En este estudio se analizaron los parámetros viscoelásticos y de agregación en glóbulos rojos humanos sometidos a los procedimientos habituales de irradiación gamma con fines transfusionales. Las muestras fueron irradiadas a diferentes dosis a fin de determinar los posibles cambios hemorreológicos que pudieran afectar a la salud de los pacientes y su relación con las modificaciones bioquímicas observadas. Los resultados obtenidos muestran alteraciones en el tiempo de agregación, en la viscosidad superficial de membrana y en el tamaño de los agregados eritrocitarios en las muestras irradiadas, sugiriendo que el daño producido por la radiación ionizante afecta a las propiedades físicas de la membrana del glóbulo rojo en diferentes nivelesIn this study, the alterations in viscoelastic and aggregation parameters of red blood cells were analyzed for usual gamma irradiation procedures for transfusion purposes. In order to determine possible hemorheological changes that may affect the health of patients and their relationship with the biochemical changes observed, the blood samples were irradiated at different doses. The results show alterations in the erythrocyte aggregation time, in the membrane surface viscosity and in the size of the aggregates in the irradiated samples, suggesting that the damage produced by the ionizing radiation affects the physical properties of red blood cell membrane at different levels.Fil: Estrada, E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Castellini, H.. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; ArgentinaFil: Acosta, A.. Centro Regional de Hemoterapia; ArgentinaFil: Di Tullio, L.. Centro Regional de Hemoterapia de Rosario; ArgentinaFil: Borraz, J.. Centro Regional de Hemoterapia de Rosario; ArgentinaFil: Chinellato, A.. Centro Regional de Hemoterapia de Rosario; ArgentinaFil: Tack, I.. Centro Regional de Hemoterapia de Rosario; ArgentinaFil: D'Arrigo, M.. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; ArgentinaFil: Riquelme, Bibiana Doris. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Galassi, Mariel Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; Argentin