On the use of asymmetric PSF on NIR images of crowded stellar fields

We present data collected using the camera PISCES coupled with the Firt Light Adaptive Optics (FLAO) mounted at the Large Binocular Telescope (LBT). The images were collected using two natural guide stars with an apparent magnitude of R<13 mag. During these observations the seeing was on average ~0.9". The AO performed very well: the images display a mean FWHM of 0.05 arcsec and of 0.06 arcsec in the J- and in the Ks-band, respectively. The Strehl ratio on the quoted images reaches 13-30% (J) and 50-65% (Ks), in the off and in the central pointings respectively. On the basis of this sample we have reached a J-band limiting magnitude of ~22.5 mag and the deepest Ks-band limiting magnitude ever obtained in a crowded stellar field: Ks~23 mag. J-band images display a complex change in the shape of the PSF when moving at larger radial distances from the natural guide star. In particular, the stellar images become more elongated in approaching the corners of the J-band images whereas the Ks-band images are more uniform. We discuss in detail the strategy used to perform accurate and deep photometry in these very challenging images. In particular we will focus our attention on the use of an updated version of ROMAFOT based on asymmetric and analytical Point Spread Functions. The quality of the photometry allowed us to properly identify a feature that clearly shows up in NIR bands: the main sequence knee (MSK). The MSK is independent of the evolutionary age, therefore the difference in magnitude with the canonical clock to constrain the cluster age, the main sequence turn off (MSTO), provides an estimate of the absolute age of the cluster. The key advantage of this new approach is that the error decreases by a factor of two when compared with the classical one. Combining ground-based Ks with space F606W photometry, we estimate the absolute age of M15 to be 13.70+-0.80 Gyr.Comment: 15 pages, 7 figures, presented at the SPIE conference 201

Dietary Neurotransmitters: A Narrative Review on Current Knowledge

Foods are natural sources of substances that may exert crucial effects on the nervous system in humans. Some of these substances are the neurotransmitters (NTs) acetylcholine (ACh), the modified amino acids glutamate and γ-aminobutyric acid (GABA), and the biogenic amines dopamine, serotonin (5-HT), and histamine. In neuropsychiatry, progressive integration of dietary approaches in clinical routine made it necessary to discern the more about some of these dietary NTs. Relevant books and literature from PubMed and Scopus databases were searched for data on food sources of Ach, glutamate, GABA, dopamine, 5-HT, and histamine. Different animal foods, fruits, edible plants, roots, and botanicals were reported to contain NTs. These substances can either be naturally present, as part of essential metabolic processes and ecological interactions, or derive from controlled/uncontrolled food technology processes. Ripening time, methods of preservation and cooking, and microbial activity further contributes to NTs. Moreover, gut microbiota are considerable sources of NTs. However, the significance of dietary NTs intake needs to be further investigated as there are no significant data on their bioavailability, neuronal/non neuronal effects, or clinical implications. Evidence-based interventions studies should be encouraged

A possible concept for the day-time calibration and co-phasing of the adaptive M4 mirror at the E-ELT telescope

The M4 unit is the deformable mirror providing the E-ELT with adaptive correction of the atmospheric turbulence. The mirror is segmented into 6 petals which are actively shaped by more than 5000 voice-coil actuators. They are controlled in close loop with internal metrology through co-located capacitive position sensors. INAF is involved in the optical calibration and verification of the M4 unit and designed the laboratory optical testbed In this paper, we present a possible auxiliary setup for the mirror calibration once installed at the telescope. The concept implements an on-demand, day-time, optical re-calibration of the mirror, to ensure the years-long term, high accuracy, high precision stability of the internal metrology, beyond the already remarkable intrinsic electronic stability of the M4 unit. The setup exploits the two focii of the quasi-elliptical M3 to create an optical cavity, with the interferometer placed at a Nasmyth focal station of the ELT and a retroreflector (or fiber source) at the M3 short focus to measure the M4 in double (or single) pass. The full monitoring of the M4 optical area allows to: calibrate the actuator influence functions to compute the segments piston tip/tilt commands with high precision; retrieve the flattening command to correct from the low and high order features generated by thermo-mechanical and electrical drifts; compute the phasing command to correct for the segments differential alignment and piston within the requested WF accuracy. The system offers a fast and effective optical maintenance facility for the M4U, without requiring an additional test tower and the mount/dismount down-time of the unit. In this work, we summarize the optical layout and the flattening and segments co-phasing strategy

8s, a numerical simulator of the challenging optical calibration of the E-ELT adaptive mirror M4

8s stands for Optical Test TOwer Simulator (with 8 read as in italian 'otto'): it is a simulation tool for the optical calibration of the E-ELT deformable mirror M4 on its test facility. It has been developed to identify possible criticalities in the procedure, evaluate the solutions and estimate the sensitivity to environmental noise. The simulation system is composed by the finite elements model of the tower, the analytic influence functions of the actuators, the ray tracing propagation of the laser beam through the optical surfaces. The tool delivers simulated phasemaps of M4, associated with the current system status: actuator commands, optics alignment and position, beam vignetting, bench temperature and vibrations. It is possible to simulate a single step of the optical test of M4 by changing the system parameters according to a calibration procedure and collect the associated phasemap for performance evaluation. In this paper we will describe the simulation package and outline the proposed calibration procedure of M4

Oral Hydration Before and After Hip Replacement: The Notion Behind Every Action.

Introduction: Even though nearly 20 patients undergo hip replacement every hour just in Italy and the United Kingdom, it is unclear what are the most appropriate oral hydration practices that patients should follow before and after surgery. Improper administration can cause postoperative fluid disturbances or exacerbate pre-existing conditions, which are not an uncommon find in older subjects. Significance: Considering that the number of hip operations is expected to increase in the next years as well as the age of patients, it is important to recall the notions behind water balance, especially in light of modern surgical and anesthetic practices. This technical perspective discusses the perioperative changes in the hydration status that occur during hip replacement and provides the concepts that help clinicians to better manage how much water the patient can drink. Results: The points of view of the surgeon, the anesthetist, and the nurse are offered together with the description of mineral waters intended for human consumption. Before surgery, water should be always preferred over caffeinated, sugar-sweetened, and alcoholic beverages. The drinking requirements on the day of surgery should consider the water output from urine, feces, respiration, exudation, and bleeding along with the water input from metabolic production and intravenous administration of fluids and medications. Healthy eating habits provide water and should be promoted before and after surgery. Conclusions: The judgment on which is the most appropriate approach to oral hydration practices must be the responsibility of the multidisciplinary perioperative team. Nevertheless, it is reasonable to argue that, in the presence of a patient with no relevant illness and who follows a healthy diet, it is more appropriate to stay closer to dehydration than liberalizing water intake both prior to surgery and in the early postoperative hours until the resumption of normal physiological functions

Astro MBSE: model based system engineering synthesized for the Italian astronomical community

Systems Engineering requires the involvement of different engineering disciplines: Software, Electronics, Mechanics (often nowadays together as Mechatronics), Optics etc. Systems Engineering of Astronomical Instrumentation is no exception to this. A critical point is the handling of the different point of view introduced by these disciplines often related to different tools and cultures. Model Based Systems Engineering (MBSE) approach can help the Systems Engineer to always have a complete view of the full system. Moreover, in an ideal situation, all of the information resides in the model thus allowing different views of the System without having to resort to different sources of information, often outdated. In the real world, however, this does not happen because the different actors (Optical Designers, Mechanical Engineers, Astronomers etc.) should adopt the same language and this is clearly, at least nowadays and for the immediate future, close to impossible. In the Italian Astronomical Community, we are developing methodologies and tools to share the expertise in this field among the different projects. In this paper we present the status of this activity that aims to deliver to the community proper tools and template to enable a uniformed use of MBSE (friendly name Astro MBSE) among different projects (ground and space based, …). We will analyze here different software and different approaches. The target and synthesis of this work will be a support framework for the MBSE based system Engineering activity to the Italian Astronomical Community (INAF)

Astro MBSE: overview on requirement management approaches for astronomical instrumentation

Systems Engineering requires the involvement of different engineering disciplines: Software, Electronics, Mechanics (often nowadays together as Mechatronics), Optics etc. Astronomical Instrumentation is no exception to this. A critical point is the handling of the requirements, their tracing, flow down and the interaction with stakeholders (flow up) and subsystems (flow down) in order to have traceable and methodical evolution and management. In the Italian Astronomical Community, we are developing methodologies and tools to share the expertise in this field among the different projects. In this paper we will focus on the requirement management approach among different projects (ground and space based, …). The target and synthesis of tis work will be a support framework for the Requirement management of the Italian Astronomical Community (INAF) projects

The LATT way towards large active primaries for space telescopes

The Large Aperture Telescope Technology (LATT) goes beyond the current paradigm of future space telescopes, based on a deformable mirror in the pupil relay. Through the LATT project we demonstrated the concept of a low-weight active primary mirror, whose working principle and control strategy benefit from two decades of advances in adaptive optics for ground-based telescopes. We developed a forty centimeter spherical mirror prototype, with an areal density lower than 17 kg/m2, controlled through contactless voice coil actuators with co-located capacitive position sensors. The prototype was subjected to thermo-vacuum, vibration and optical tests, to push its technical readiness toward level 5. In this paper we present the background and the outcomes of the LATT activities under ESA contract (TRP programme), exploring the concept of a lightweight active primary mirror for space telescopes. Active primaries will open the way to very large segmented apertures, actively shaped, which can be lightweight, deployable and accurately phased once in flight

Laboratory demonstration of a primary active mirror for space with the LATT: large aperture telescope technology

The LATT project is an ESA contract under TRP programme to demonstrate the scalability of the technology from ground-based adaptive mirrors to space active primary mirrors. A prototype spherical mirror based on a 40 cm diameter 1 mm thin glass shell with 19 contactless, voice-coil actuators and co-located position sensors have been manufactured and integrated into a final unit with an areal density lower than 20 kg/m2. Laboratory tests demonstrated the controllability with very low power budget and the survival of the fragile glass shell exposed to launch accelerations, thanks to an electrostatic locking mechanism; such achievements pushes the technology readiness level toward 5. With this prototype, the LATT project explored the feasibility of using an active and lightweight primary for space telescopes. The concept is attractive for large segmented telescopes, with surface active control to shape and co-phase them once in flight. In this paper we will describe the findings of the technological advances and the results of the environmental and optical tests

E-ELT M4 adaptive unit final design and construction: a progress report

The E-ELT M4 adaptive unit is a fundamental part of the E-ELT: it provides the facility level adaptive optics correction that compensates the wavefront distortion induced by atmospheric turbulence and partially corrects the structural deformations caused by wind. The unit is based on the contactless, voice-coil technology already successfully deployed on several large adaptive mirrors, like the LBT, Magellan and VLT adaptive secondary mirrors. It features a 2.4m diameter flat mirror, controlled by 5316 actuators and divided in six segments. The reference structure is monolithic and the cophasing between the segments is guaranteed by the contactless embedded metrology. The mirror correction commands are usually transferred as modal amplitudes, that are checked by the M4 controller through a smart real-time algorithm that is capable to handle saturation effects. A large hexapod provides the fine positioning of the unit, while a rotational mechanism allows switching between the two Nasmyth foci. The unit has entered the final design and construction phase in July 2015, after an advanced preliminary design. The final design review is planned for fall 2017; thereafter, the unit will enter the construction and test phase. Acceptance in Europe after full optical calibration is planned for 2022, while the delivery to Cerro Armazones will occur in 2023. Even if the fundamental concept has remained unchanged with respect to the other contactless large deformable mirrors, the specific requirements of the E-ELT unit posed new design challenges that required very peculiar solutions. Therefore, a significant part of the design phase has been focused on the validation of the new aspects, based on analysis, numerical simulations and experimental tests. Several experimental tests have been executed on the Demonstration Prototype, which is the 222 actuators prototype developed in the frame of the advanced preliminary design. We present the main project phases, the current design status and the most relevant results achieved by the validation tests