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Metabolic syndrome (MetS) is a cluster of cardiovascular risk factors that include obesity, impaired glucose tolerance or diabetes, hyperinsulinemia, hypertension, and dyslipidemia. Recently, more attention has been reserved to the correlation between periodontitis and systemic health. MetS is characterized by oxidative stress, a condition in which the equilibrium between the production and the inactivation of reactive oxygen species (ROS) becomes disrupted. ROS have an essential role in a variety of physiological systems, but under a condition of oxidative stress, they contribute to cellular dysfunction and damage. Oxidative stress may act as a common link to explain the relationship between each component of MetS and periodontitis. All those conditions show increased serum levels of products derived from oxidative damage, promoting a proinflammatory state. Moreover, adipocytokines, produced by the fat cells of fat tissue, might modulate the balance between oxidant and antioxidant activities. An increased caloric intake involves a higher metabolic activity, which results in an increased production of ROS, inducing insulin resistance. At the same time, obese patients require more insulin to maintain blood glucose homeostasis – a state known as hyperinsulinemia, a condition that can evolve into type 2 diabetes. Oxidation products can increase neutrophil adhesion and chemotaxis, thus favoring oxidative damage. Hyperglycemia and an oxidizing state promote the genesis of advanced glycation end-products, which could also be implicated in the degeneration and damage of periodontal tissue. Thus, MetS, the whole of interconnected factors, presents systemic and local manifestations, such as cardiovascular disease and periodontitis, related by a common factor known as oxidative stress.

We analyze the effects of imperfectly known central banker’s preferences on optimal linear contracts offered by the government and an interest group. These effects depend on the type of uncertainty faced by the principals. When the central bank’s output target is uncertain the results by Campoy and Negrete (Public Choice 137:197–206, 2008) under perfectly known preferences obtain. Uncertainty about the central banker’s degree of conservatism or about its degree of “selfishness” has a multiplicative impact on the principals’ instruments in the agent’s best response function; this may generate an inflation bias independently of the type of contract offered by the interest group.

Introduction The objective of this study was to compare skeletal maturation in obese patients and in subjects of normal weight to evaluate the best timing for orthopedic and orthodontic treatment. The null hypothesis was that obese and normal-weight patients show similar degrees of skeletal maturation. Methods The sample for this retrospective study consisted of 50 white patients (28 boys, 22 girls) whose x-rays (hand-wrist and lateral cephalometric radiographs) were already available. The test group included 25 obese patients (11 girls, 14 boys; average age, 9.8 ± 2.11 years), and the control group included 25 subjects of normal weight (11 girls, 14 boys; average age, 9.9 ± 2.5 years). Skeletal maturation was determined by using the carpal analysis method and the cervical vertebral maturation method. Results According to the carpal analysis, there was a significant difference between skeletal and chronologic ages between the test group (11.8 ± 11.4 months) and the control group (–2.9 ± 3.1 months). Furthermore, the obese subjects exhibited a significantly higher mean cervical vertebral maturation score (2.8 ± 0.7) than did the control subjects (2 ± 0.6) ( P Conclusions Compared with the normal-weight subjects, the obese subjects showed a higher mean discrepancy between skeletal and chronologic ages according to the carpal analysis and had a significantly higher cervical vertebral maturation score. Thus, to account for the growth in obese patients with skeletal discrepancies, it might be necessary to perform examinations and dentofacial and orthopedic treatments earlier than in normal-weight subjects.

Background Studies on the relationship between occlusal problems and the spine are of increasing interest. In this study, we monitored the sEMG activity of masticatory, neck, and trunk muscles during the treatment of scoliosis in young patients, and compared the data with a control of untreated group. Subjects and methods Twelve white Caucasian patients (nine males and three females; mean age of 8.0±1.5years) with scoliosis and Class I occlusion (without crowding) were included in this study (study group). Fifteen healthy subjects (nine males and six females; mean age of 9.5±0.8years) were recruited as control group. The subjects were visited before they underwent the treatment of scoliosis, as well as after 3 (T1) and 6months (T2) of their treatment for scoliosis. The patients were instructed to wear the device during sleep and during the day, according to the protocol given by their orthopedic. Results The treated group showed statistically significant changes in the sEMG activity of masticatory, neck, and trunk muscles, both at rest and during MVC of the mandible with respect to T0. The masseter and the anterior temporalis showed a significant improvement in the asymmetry index from T0 to T2. On the other hand, subjects in the control group did not register much change. Conclusion Our findings suggest that the use of a functional device for the treatment of scoliosis induces a significant reduction in the asymmetry index of the trunk muscles, as well as a significant increase in the contractility of masticatory muscles.

Halitosis disease results in a distinctive volatile fingerprint of the individual exhaled breath. Here a QMB based electronic nose has been used to study such fingerprints. This study aimed at following the time evolution of halitosis conditions in patients undergoing two different treatments. Professional operators assessed oral odor, and their evaluation was used for classifier training. Results show that the electronic nose can identify the presence of oral malodor and the attenuation of the condition achieved by the application of the treatment.

The current baseline for the Multi-Conjugate adaptive optics module (MAORY) for the European Extremely Large Telescope is based on the Sodium Laser Guide Stars (LGS) approach, in order to ensure correction uniformity and sky coverage. However, since the Sodium layer is approximately 10 km thick, the artificial reference source looks elongated, especially when observed from the edge of a large aperture, with elongation depending on the actual telescope diameter, on the Sodium layer properties and on the laser launcher position. We studied numerically, by means of simulations, the performance of three different algorithms for the instantaneous LGS image position measurement in presence of elongated spots: the Weighted Center of Gravity, the Correlation and the Quad-cell. Since all the three considered algorithms require some sort of 'reference', the problem of the temporal variation of the Sodium Layer properties has to be addressed. Another important aspect that has be addressed in the analysis is the impact of the low-order aberrations introduced by the MAORY re-imaging optics, by the Sodium Density profile shape and by its projection in the LGS image plane. An LGS wavefront sensor laboratory prototype was designed to reproduce the relevant aspects of a Shack-Hartmann wavefront Sensor for the European Extremely Large Telescope and, through laboratory tests, to evaluate the performance of different centroid algorithms in presence of elongated spots, with realistic Sodium profiles, as previously investigated numerically and analytically, analyzing the impact of the low-order aberrations and of relevant WFS parameters, like signal-to-noise ratio, sampling and subaperture size. This paper shows the results of the tests performed with this prototype.

The Multi-conjugate Adaptive Optics RelaY (MAORY) for the European Extremely Large Telescope (E-ELT) provides a corrected field of view of up to 2 arcmin diameter over the wavelength range 0.8-2.4 μm. It is expected to achieve a correction of high quality and uniformity with high sky coverage: with a seeing of 0.8 arcsec in the visible, the expected Strehl Ratio averaged over a 1 arcmin field is approximately 50% at 2.16 μm wavelength over 50% of the sky at the Galactic Pole. Wavefront correction is obtained by means of the E-ELT adaptive mirrors M4/M5 and of two post-focal deformable mirrors conjugated at 4km and 12.7km from the telescope pupil. Wavefront sensing is performed by 6 Sodium laser guide stars and by 3 natural guide stars, used to measure atmospheric and windshake tilt and to provide a reference for the focus and for the low-order aberrations induced by the Sodium layer. MAORY is located on the E-ELT Nasmyth platform and has a gravity invariant port, feeding the high angular resolution camera MICADO, and a lateral port for a detached instrument as the infrared spectrograph SIMPLE.

As of 2013, the ESO's VLT will be equipped with the Adaptive Optics Facility for Ground Layer and Laser Tomography adaptive optics assisted imaging and spectroscopy, using a Deformable Secondary Mirror and four Laser Guide Stars. Following the successful experience of the MAD demonstrator, we initiated a speculative study to evaluate the performance gain obtained by implementing a type of Multi-Conjugate Adaptive Optics correction that benefits from the unique features provided by the AOF. In this paper we present the basic concept and provide a first estimation of the correction performance obtained in the near infrared.

In this paper we present a brief status report on the conceptual designs of the instruments and adaptive optics modules that have been studied for the European Extremely Large Telescope (E-ELT). In parallel with the design study for the 42-m telescope, ESO launched 8 studies devoted to the proposed instruments and 2 for post-focal adaptive optics systems. The studies were carried out in consortia of ESO member state institutes or, in two cases, by ESO in collaboration with external institutes. All studies have now been successfully completed. The result is a powerful set of facility instruments which promise to deliver the scientific goals of the telescope. The aims of the individual studies were broad: to explore the scientific capabilities required to meet the E-ELT science goals, to examine the technical feasibility of the instrument, to understand the requirements placed on the telescope design and to develop a delivery plan. From the perspective of the observatory, these are key inputs to the development of the proposal for the first generation E-ELT instrument suite along with the highest priority science goals and budgetary and technical constraints. We discuss the lessons learned and some of the key results of the process.

MAORY, the Multi-conjugated Adaptive Optics RelaY for the European Extremely Large Telescope, will be located on one of the Nasmyth platforms of the telescope to provide multi conjugated adaptive optics correction of the wavefront. The scientific instruments fed by the module will benefit from a corrected field of view of 2 arcmin diameter with high performance uniformity across the field. The two post-focal deformable mirrors are projected at high altitude by the optical system based on 5 mirrors and one dichroic which splits the laser light of the artificial reference stars from the science channel. The third deformable mirror, conjugated to the ground, is integrated into the telescope. Six laser guide stars are foreseen in order to measure the wavefront distortions and three natural guide stars are used to solve the tip-tilt indetermination problem. The natural guide stars wavefront sensors are located close to the output focal plane in order to minimize the non common path aberrations. Two output ports are foreseen: one gravity invariant located below the optical bench and one on one side of the bench to feed large instruments placed on the Nasmyth platform.

This paper explores the ability of a class of one-sector models to generate endogenous skills cycles. Skills cycles are here defined as endogenous fluctuations of the composition of equilibrium allocation of labor services. We consider a one sector economy in which there exist one type of capital stock and a finite number of different labor services, which are assumed to be heterogeneous along the skill/productivity dimension. We apply the Hopf bifurcation theorem and provide necessary conditions on the model’s parameters for having a closed orbit as the economy’s stable set. We also develop a numerical example (based on the United States economy) showing how this closed orbit can appear under reasonable parameter values.

International audience; The future 42m diameter European Extremely Large Telescope (E-ELT) is foreseen to use Sodium Laser Guide Stars (LGS) in order to increase sky coverage and correction uniformity. The E-ELT MCAO module, MAORY, will use 6 LGSs to measure the Wavefront (WF) aberrations by means of Shack-Hartmann (SH) sensors. However the LGSs are affected by peculiar problems related to the atmospheric Sodium layer. The non-negligible thickness of the layer, for instance, causes the artificial reference source to look elongated, especially in WF sensor sub-apertures at the edge of the pupil. The WF sensor performance are limited by the elongation itself as well as by the fluctuations of the Sodium layer altitude, thickness and density. In particular these fluctuations have dramatic effects on the robustness of the algorithms used for the WF measurement. Moreover the defocus measurement is compromised by a strong non-atmospheric component. Another important aspect is the impact of the low-order aberrations introduced on the LGS images by the MCAO module optics that are optimized for infinite conjugate imaging, while the LGS is at a finite distance. We present in this paper a laboratory prototype that simulates an elongated source that can trace out some LGS features such as the arbitrary profile and altitude variation. In the optical path of the prototype three pupil images are foreseen. High order and low order aberrations can be introduced in the first two pupil planes by means of static screens and a Deformable Mirror (DM) respectively. The WF is then measured by a 40x40 sub-apertures SH Sensor. The main aim of the prototype is to check performance and robustness of WF Sensor algorithms for different illumination conditions, varying aberrations and pixel scale.

International audience; MAORY is the Multi-conjugate Adaptive Optics RelaY module for the European Extremely Large Telescope. It will be located on the Nasmyth platform of the telescope to feed scientific instruments. The module is supposed to re-image one to one the telescope focal plane with diffraction limited optical quality and to provide multi-conjugate adaptive optics correction of the wavefront distortion induced by the atmosphere. The system is based on six laser guide stars for sensing the wavefront distortion and three deformable mirrors for correcting it. A dichroic is used to split the laser light from the light of the scientific and natural guide stars channel. Two output ports, selected by the dichroic orientation, are foreseen: one in a gravity invariant configuration and one in a vertical position to feed large instruments. In this article the current optical and mechanical design are presented together with the thermal analysis.

International audience; MAORY is the multi-conjugate adaptive optics module for the European Extremely Large Telescope. A conceptual design study is in progress and is approaching the final review. A description of the current design and of the expected performance is presented.

Relativistic jets are a common feature of radio loud active galactic nuclei. Multifrequency observations are a unique tool to constrain their physics. We report on a detailed study of the properties of the jet of the nearby BL Lac object PKS 2201+044, one of the rare cases where the jet is detected from radio to X-rays. We use new adaptive optics near-IR observations of the source, obtained with the ESO multi-conjugated adaptive optics demonstrator (MAD) at the Very Large Telescope. These observations acquired in Ground-Layer Adaptive Optics mode are combined with images previously achieved by HST, VLA and Chandra to perform a morphological and photometric study of the jet. We find a noticeable similarity in the morphology of the jet at radio, near-IR and optical wavelengths. We construct the spectral shape of the main knot of jet that appears dominated by synchrotron radiation. On the basis of the jet morphology and the weak lines spectrum we suggest that PKS 2201+044 belongs to the class of radio sources intermediate between FRIs and FRIIs., Comment: 11 pages, 8 figures, accepted for pubblication in A&A

This paper introduces underground activities and tax evasion into a one-sector dynamic general equilibrium model with aggregate external effects. The model presents a novel mechanism driving the self-fulfilling prophecies, which is characterized by well behaved (downward sloping) labor demand schedules. This mechanism differs from the customary one, and it is complementary to it. Compared to traditional labor market income, the income derived from underground labor activity is subject to a lower expected tax rate when considering both the probability of detection and the evasion penalty. During a belief-driven expansion, the household allocates more time to both traditional and underground labor supply. In equilibrium, this action serves to lower the effective labor tax rate faced by the household, thus providing stimulus to aggregate labor supply so as to make the initial expansion self-fulfilling. The mechanism here is akin to a “regressive tax”; the household's effective tax rate depends negatively on the level of total labor income. We argue that an underground sector, and the associated tax evasion, offer a good economic rationale for a regressive tax rate.

Adaptive-optics systems can in principle allow a telescope to achieve performance at its theoretical maximum (limited only by diffraction), by correcting in real time for the distortion of starlight by atmospheric turbulence. For such a system installed on an 8-m-class telescope, the spatial resolution and sensitivity could be up to 100 times better than conventional imaging. Adaptive-optics corrections have hitherto been achieved only for regions of the sky within a few arcseconds of a bright reference source. But it has been proposed theoretically that by using multiple guide stars, the tomography of atmospheric turbulence could be probed and used to extend adaptive-optics corrections to the whole sky. Here we report the experimental verification of such tomographic corrections, using three off-axis reference stars approximately 15 arcsec from the central star. We used the observations of the off-axis stars to calculate the deformations of the wavefront of the central star, and then compare them with the real measured values. This tomographic approach is found to reduce variations in the wavefront by approximately 92%. Our result demonstrates that a serious barrier to achieving diffraction-limited seeing over the whole sky has been removed.

Kobayashi (2003) aims to show that, in a model without inflationary bias, an increase in the degree of multiplicative uncertainty on the transmission mechanism of monetary policy improves social welfare when central bank’s preferences are highly uncertain. We demonstrate that this result applies only to the case in which society is strictly conservative, i.e., when the weight attached to output in the social welfare function is lower than one.

Over the past years, the lambda-Orionis cluster has been a prime location for the study of young very low mass stars, substellar and isolated planetary mass objects and the determination of the initial mass function and other properties of low mass cluster members. In the continuity of our previous studies of young associations cores, we search for ultracool members and new multiple systems within the central 5.3' (~0.6pc) of the cluster. We obtained deep seeing limited J, Ks-band images of the 5.3' central part of the cluster with NTT/SofI and H-band images with CAHA/Omega2000. These images were complemented by multi-conjugate adaptive optics (MCAO) H and Ks images of the 1.5' central region of the lambda-Orionis cluster obtained with the prototype MCAO facility MAD at the VLT. The direct vicinity of the massive lambda-Ori O8III-star was probed using NACO/SDI at the VLT. Finally, we also retrieved Spitzer IRAC images of the same area and used archival Subaru Suprime-Cam and CFHT CFHT12K i-band images. We report the detection of 9 new member candidates selected from optical and near-IR color-color and color-magnitude diagrams and 7 previously known members. The high spatial resolution images resolve 3 new visual multiple systems. Two of them are most likely not members of the association. The third one is made of a brown dwarf candidate companion to the F8V star HD36861C. The simultaneous differential images allow us to rule out the presence of visual companions more massive than M>0.07Msun in the range 1-2.5", and M>0.25Msun in the range 0.5-2.5", accepted for publication in A&A

BL Lac objects are low--power active nuclei exhibiting a variety of peculiar properties that are caused by the presence of a relativistic jet and orientation effects. We present here adaptive optics near-IR images at high spatial resolution of the nearby BL Lac object PKS 0521-365, which is known to display a prominent jet both at radio and optical frequencies. The observations were obtained in Ks--band using the ESO multi-conjugated adaptive optics demonstrator at the Very Large Telescope. This allowed us to obtain images with 0.1 arcsec effective resolution. We performed a detailed analysis of the jet and its related features from the near-IR images, and combined them with images previously obtained with HST in the R band and by a re-analysis of VLA radio maps. We find a remarkable similarity in the structure of the jet at radio, near-IR, and optical wavelengths. The broad--band emission of the jet knots is dominated by synchrotron radiation, while the nucleus also exhibits a significant inverse Compton component. We discovered the near-IR counterpart of the radio hotspot and found that the near-IR flux is consistent with being a synchrotron emission from radio to X-ray. The bright red object (red-tip), detached but well aligned with the jet, is well resolved in the near-IR and has a linear light profile. Since it has no radio counterpart, we propose that it is a background galaxy not associated with the jet. The new adaptive optics near-IR images and previous observations at other frequencies allow us to study the complex environment around the remarkable BL Lac object PKS 0521-365. These data exemplify the capabilities of multi conjugate adaptive optics observations of extragalactic extended sources., Comment: accepted for publication in Astronomy and Astrophysics 9 pages. A & A 2009, in press

Deep photometry of crowded fields, such as Galactic Globular Clusters, is severely limited by the actual resolution of ground-based telescopes. On the other hand, the Hubble Space Telescope does not provide the near-infrared (NIR) filters needed to allow large color baselines. In this work we aim at demonstrating how ground based observations can reach the required resolution when using Multi-Conjugated Adaptive Optic (MCAO) devices in the NIR, such as the experimental infrared camera (MAD) available on the VLT. This is particularly important since these corrections are planned to be available on all ground--based telescopes in the near future. We do this by combining the infrared photometry obtained by MAD/VLT with ACS/HST optical photometry of our scientific target, the bulge globular cluster NGC 6388, in which we imaged two fields. In particular, we constructed color-magnitude diagrams with an extremely wide color baseline in order to investigate the presence of multiple stellar populations in this cluster. From the analysis of the external field, observed with better seeing conditions, we derived the deepest optical-NIR CMD of NGC 6388 to date. The high-precision photometry reveals that two distinct sub-giant branches are clearly present in this cluster. We also use the CMD from the central region to estimate the distance ((m-M)=15.33) and the reddening (E(B-V)=0.38) for this cluster. We estimate the age to be ~11.5+/- 1.5 Gyr. The large relative-age error reflects the bimodal distribution of the SGB stars. This study clearly demonstrates how MCAO correction in the NIR bands implemented on ground based telescopes can complement the high-resolution optical data from HST., 9 pages, 10 figures. Accepted for publication on A. & A

Simulations of adaptive optics (AO) for the European extremely large telescope (EELT) are presented. For Shack-Hartmann wavefront sensors for the laser guide star (LGS) based systems, the simulations show that without the Rayleigh fratricide effect, central projection of the laser is preferable to side projection, the correlation or matched filter centroiding algorithms offer superior performance to a traditional center-of-gravity approach, the optimum sampling of the detector is approximately 1.5 pixels per FWHM of the non-elongated spot, and that at least 10×10 pixels are required. The required number of photo-detection events from the LGS per frame per subaperture is of the order of 1000. Correction of segmentation errors with a Shack-Hartmann wavefront sensor (WFS) has also been investigated; atmospheric turbulence dominates these segmentation errors. The pyramid WFS is also simulated for the EELT, showing that modulation of the pyramid will be necessary.

MAORY, the multi-conjugate adaptive optics module for the E-ELT, is supposed to be placed in one of the two Nasmyth platforms of the telescope, re-imaging the focal plane with a diffraction limited image quality. The requested operating wavelength is from 0.6 to 2.4μm with a high throughput. The module will include a natural guide stars wave front sensor (NGS WFS) and a laser guide stars WFS (LGS WFS) and will feed at least two scientific instruments with a corrected field of view up to 2 arcmin, providing a mechanical de-rotation for the light instruments attached (< 4tons). We present below a preliminary optical design of the post focal relay taking count of the required performance. A particular attention is paid to the critical aspects such as the pupil de-rotation, the light splitting between the WFSs and the scientific channel and the deformable mirrors (DMs) optical parameters and dimensioning.

In the last years an increasing consideration has been given to the study of Laser Guide Stars (LGS) for the measurement of the disturbance introduced by the atmosphere. Due to the finite distance of the artificial reference source and its vertical extension (the Sodium layer occurs at approximately 90 km, with a vertical thickness of about 10 km), the source itself looks elongated, when observed from the edge of a large aperture. On a 40 m class telescope, for instance, the maximum elongation varies between 4 and 6 arcseconds, depending on the Sodium layer properties and on the launching position. This spot elongation strongly limits the performance of the most common wavefront sensors. A straightforward solution for a Shack-Hartmann wavefront sensor is to increase the laser power, in order to balance the loss of centroiding accuracy due to the elongation. This solution, although appealing in principle, presents drawbacks related, for instance, to the availability of very powerful lasers. We propose in this paper a wavefront sensor concept that provides an optical solution to the perspective elongation problem. It is based on an array of bi-prisms placed in the focal plane of a lenslet array; each bi-prism is aligned to the elongated spot produced by the corresponding lenslet; the spot is split into two beams, that are re-imaged into two micro-images of the sub-aperture itself; the difference in the integrated intensity of these two micro-images is proportional to the local wavefront slope. This method is sensitive only to the slope information in the direction locally orthogonal to the bi-prisms (and to the elongation) and the full information has to be recovered by combining the signals coming from different LGSs launched from different positions at the telescope edge. The pros and cons of this technique, in terms of hardware requirements and photon budget, are discussed in this paper.

The multi-conjugate adaptive optics module for the European Extremely Large Telescope has to provide a corrected field of medium to large size (up to 2 arcmin), over the baseline wavelength range 0.8-2.4 µm. The current design is characterized by two post-focal deformable mirrors, that complement the correction provided by the adaptive telescope; the wavefront sensing is performed by means of a high-order multiple laser guide star wavefront sensor and by a loworder natural guide star wavefront sensor. The present status of a two years study for the advanced conceptual design of this module is reported.

The Multi-Conjugate Adaptive Optics Demonstrator (MAD) built by ESO with the contribution of two external consortia is a powerful test bench for proving the feasibility of Multi-Conjugate (MCAO) and Ground Layer Adaptive Optics (GLAO) techniques both in the laboratory and on the sky. MAD is based on a two deformable mirrors correction system and on two multi-reference wavefront sensors (Star Oriented and Layer Oriented) capable to observe simultaneously some pre-selected configurations of Natural Guide Stars. MAD corrects up to 2 arcmin field of view in K band. After a long laboratory test phase, it has been installed at the VLT and it successfully performed on-sky demonstration runs on several astronomical targets for evaluating the correction performance under different atmospheric turbulence conditions. In this paper we present the results obtained on the sky in Star Oriented mode for MCAO and GLAO configurations and we correlate them with different atmospheric turbulence parameters. Finally we compare some of the on-sky results with numerical simulations including real turbulence profile measured at the moment of the observations.

The Layer Oriented Wavefront Sensor for MAD has been used in the sky to achieve science. The preliminary results from a six night run and the perspectives in terms of achieved performances and projections of sky coverage for slightly more sophisticated system like the Multiple Field of View one are shown indicating that the sensor is keeping its promises.

The aim of this paper is to bring together two recent developments in the †contracting†approach to the time-inconsistency problem of monetary policy: linear contracts under common agency and central bank preference uncertainty under single agency. We show that under common agency and imperfect †political†transparencey, the full transparency finding that the interest group contract dominates the government’s one is confirmed, but equilibrium expected inflation is lower, as the new source of uncertainty makes the two principals more cautious in their instrument setting. This reduces the average inflation bias. We then extend the analysis to the case of uncertainty on the central bank output target and show that the expected values of inflation and output are the same as those obtained under perfect †economic†transparency, whereas the actual values are different only for the presence of an additive term depending on opacity. Finally, we demonstrate that when the principals are uncertain about the weight attached by the central banker to the incentive scheme the equilibrium inflation surprise may be negative and output may be lower than the natural rate.

Adaptive optics is used in astronomy to obtain high resolution images, close to diffraction limited, of stars and galaxies with ground telescopes, otherwise blurred by atmospheric turbulence. The measurements of one or more wavefront sensor are used to flatten distorted wavefronts with one or more deformable mirror in a feedback loop. In this brief, we shall report our experience on the problem of building an accurate (dynamical) model of the actuation (deformable mirror) and sensing (wavefront sensor) of adaptive optics system. This will be done adapting state-of-the-art system identification and model reduction techniques to the problem at hand. Our results are based on real data collected under various operating conditions from a demonstrator developed at the European Southern Observatory (ESO), which is now operating in the Paranal Observatory (Chile).

We present deep and precise photometry (F435, F625W, F658N) of Omega Cen collected with the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST). We have identified ~ 6,500 white dwarf (WD) candidates, and the ratio of WD and Main Sequence (MS) star counts is found to be at least a factor of two larger than the ratio of CO-core WD cooling and MS lifetimes. This discrepancy is not explained by the possible occurrence of a He-enhanced stellar population, since the MS lifetime changes by only 15% when changing from a canonical (Y=0.25) to a He-enhanced composition (Y=0.42). The presence of some He-core WDs seems able to explain the observed star counts. The fraction of He WDs required ranges from 10% to 80% depending on their mean mass and it is at least five times larger than for field WDs. The comparison in the Color Magnitude Diagram between theory and observations also supports the presence of He WDs. Empirical evidence indicates that He WDs have been detected in stellar systems hosting a large sample of extreme horizontal branch stars, thus suggesting that a fraction of red giants might avoid the He-core flash., 14 pages, 3 figures, accepted for publication to ApJ

International audience; A European Laser Guide Star (LGS) test facility is proposed for the 4.2m William Herschel Telescope (WHT) on La Palma. It will test the next-generation Adaptive Optics (AO) LGS technologies to aid risk mitigation of Extremely Large Telescope (ELT) LGS AO systems. In particular, critical scaling of current LGS AO technologies to ELT dimensions will be tested. For example, experiments addressing increased spot elongation, cone effect and the order of correction required. A pan-European consortium proposes to construct test facility infrastructure on the WHT for a number of risk mitigating experiments. The infrastructure includes the construction of a Nasmyth platform based controlled environment 'Ground-based Adaptive optics Innovative Laboratory' (GRAIL), an experimental test environment 'Testbed integration facility' (TIF) and some common-experiment equipment such as the Common Re-Imaging AO System. Experiments that are proposed for this facility cover the areas of laser technologies, spot elongation, LGS wavefront sensing, parallel launch concepts, Multi-Object AO, atmospheric characterisation, co-phasing and real-time control system risk mitigation.

MAD (Multi conjugate Adaptive optics Demonstrator) is an MCAO pathfinder experiment for both OverWhelmingly Large (OWL) 100-m class telescopes and ESO VLT 2nd generation instrumentation. MAD’s Wave Front Sensor (WFS) employs five thermo-electrically cooled e2v CCD39-01 devices operating in two modes: The Multi Shack-Hartmann (SH) WFS consists of three CCDs with 80x80 pixels each which are read in parallel at up to 400 frames per second delivering a pixel rate of 4.8 Mpix/sec at lowest noise. The Layer Oriented (LO) WFS is made up with two CCDs of the same type but both detectors are read simultaneously with different frame rates and binning factors using a single FIERA controller. The paper shows the concept of both the SH and LO wave front sensors and gives first performance results from laboratory tests. We report on tricks used to implement and speed up the clock patterns and the lessons learned during the development phase.

ONIRICA, standing for OWL Near InfraRed Imaging Camera, is a pre-Phase A, conceptual design study to assess the feasibility of an imaging camera for a 100m class telescope. In this paper the main scientific driven and the adopted preliminary choices for its optomechanical implementation are reviewed.

The Multi-Conjugate Adaptive Optics Demonstrator (MAD) built by ESO with the contribution of two external consortia is a powerful test bench for proving the feasibility of Ground Layer (GLAO) and Multi-Conjugate Adaptive Optics (MCAO) techniques both in the laboratory and on the sky. The MAD module will be installed at one of the VLT unit telescope in Paranal observatory to perform on-sky observations. MAD is based on a two deformable mirrors correction system and on two multi-reference wavefront sensors (Star Oriented and Layer Oriented) capable to observe simultaneously some pre-selected configurations of Natural Guide Stars. MAD is expected to correct up to 2 arcmin field of view in K band. MAD is completing the test phase in the Star Oriented mode based on Shack-Hartmann wavefront sensing. The GLAO and MCAO loops have been successfully closed on simulated atmosphere after a long phase of careful system characterization and calibration. In this paper we present the results obtained in laboratory for GLAO and MCAO corrections testing with bright guide star flux in Star Oriented mode paying also attention to the aspects involving the calibration of such a system. A short overview of the MAD system is also given.

Adaptive Optics (AO) will be essential for accomplishing many, if not most, of the science objectives currently planned for Extremely Large Telescopes including GMT, OWL, and TMT. AO will be needed to support a range of instrumentation, including near infrared (IR) imagers and spectrometers, mid IR imagers and spectrometers, “planet finding” instrumentation and wide-field optical spectrographs. Multiple advanced AO systems, utilizing the full range of concepts currently under development, will need to be combined into an integrated architecture to meet a broad range of requirements for field-of-view, spatial resolution and spectral bandpass. In this paper, we describe several of the possible options for these systems and outline the range of issues, trade studies and component development activities which must be addressed. Some of these challenges include very high-order, large-stroke wavefront correction, tip-tilt sensing with faint natural guide stars to maximize sky coverage, laser guide star wavefront sensing on a very large aperture and achieving extremely high contrast ratios for the detection of extra-solar planet and other faint companions of nearby bright stars., The Scientific Requirements for Extremely Large Telescopes, 232nd Symposium of the International Astronomical Union, November 14-18, 2005, Cape Town, South Africa, Series: Proceedings of the International Astronomical Union

This paper explores the ability of a class of one-sector, multi-input models to generate indeterminate equilibrium paths, and endogenous cycles, without relying on factors' hoarding. The model presents a novel theoretical economic mechanism that supports sunspot-driven expansions without requiring upward sloping labor demand schedules. Its distinctive characteristic is that the skill composition of aggregate labor demand drives expansionary i.i.d. demand shocks. Next, the model explains the labor market dynamics from the supply side, while endogenizing the capital productivity response to changes in the aggregate labor demand composition. Last but not least, it is worth to mention that the model presents an effective shock propagation mechanism that operates into the labor market and across labor market segments through the cross elasticities of equilibrium labor demand and supplies. In this respect the model can be seen as quite general formulation (with or without aggregate increasing returns to scale) for analyzing labor market dynamics within a general equilibrium model with labor market segmentation.

Several designs of future Adaptive Optics (AO) systems propose to use a large Deformable Mirror (DM), regarding the size as well as the number of actuators. Most of the time, there is no focal plane upstream the DM. Therefore, the classical way of calibrating the interaction matrix on an artificial source cannot be applied. Furthermore, the requirements in terms of calibration error budget are tight and the high order modes of such DMs are stiff and hence they achieve only a small stroke. This is why novel ways to determine the system Interaction Matrix (IM) have to be investigated. Several paths have been studied. One solution would be to simulate a synthetic IM. However, calibration on sky is also an option. Different techniques were simulated, tested and optimized on real AO systems. The results are presented in this paper.

In a unionised economy with supply-side fiscal policy transparency has two contrasting effects on economic performance. Uncertainty on central bank's preferences induces unions to reduce wages but also produces a fully-anticipated expansionary fiscal policy which favours the setting of higher wages. Even if the net effect depends on the preference parameters of public entities and on the effectiveness of fiscal policy on aggregate supply: (i) the positive effects of opacity in unionised economies without fiscal policy are confirmed when the central bank is populist; (ii) if it is instead sufficiently conservative, transparency reduces inflation and the output gap, but at the cost of higher macroeconomic volatility.

In this paper we present the final design and the status report of the MAD module that will be installed at one of the VLT unit telescope in Paranal to perform on-sky observations. MAD is a prototype MCAO system performing wide field of view (FoV) AO correction over 2 arcmin on the sky by using bright (m/sub v/ < 14) natural guide stars (NGS). Multiconjugate adaptive optics aims at performing wide field of view atmospheric turbulence correction using many guide stars (GSs) surrounding the observed target. The light coming from the GSs is analyzed through wavefront sensors whose signals are used to reconstruct the atmospheric turbulence at the different heights which some deformable mirrors are conjugated to. The European Southern Observatory in collaboration with external research institutes is building an instrument prototype, the MCAO demonstrator (MAD), to prove on the sky the feasibility of the MCAO technique using both reconstruction approaches in the view of the future 2nd generation of the VLT instrumentation and the 100-meters telescope OWL.

This paper focuses on the “contingent†view of transparency. By introducing endogenous fiscal policy and labour market distortions, it studies the effects the uncertainty in central bank’s (CB) preferences on the behaviour of wage and fiscal authorities and thus on output and inflation. We consider the problem on both positive and normative perspectives. First, we investigate the effects of a given degree of uncertainty in CB’s preferences on inflation and real output. Second, in line with recent literature, by assuming the possibility that information on CB’s preferences may be an endogenous variable, we study the optimal degree of transparency from the CB’s viewpoint. Although a general analysis is presented, we focus on the case of a small-bounded variance of CB’s preference, i.e. we assume that the CB’s power of affecting information disclosure and influencing private beliefs is limited.

This paper shows under indeterminacy and tax evasion, an increase in corporate, labor or income tax rates pushes the economy into an expansionary pattern. These effects are reversed when the steady state is saddle-path stable.

MAD5 is a Multi-Conjugate Adaptive Optics (MCAO) system conceived to demonstrate the feasibility of MCAO on the sky. The wave front sensor part is divided in two channels: a Shack-Hartmann sensor and a Layer Oriented sensor. We will describe the construction of the latter one. Assembly, integration and test of the instrument are the first steps for ESO acceptance, before integrating the Layer Oriented sensor with the other components of MAD. We will show qualitative and quantitative results of optical and mechanical tests: in particular we will describe the alignment of the references selection unit, constituted by sixteen motorized linear positioners and eight star enlargers, of the beam compressor and of the two re-imaging objectives, each one conjugated to a different altitude. Being the pyramid the core of this kind of wave front sensor, we will focus our attention on its construction difficulties and we will discuss all the optical tests made to choose the best ones to be installed on the wave front sensor. Finally we will present the sensor performance showing the first open loop results.

The ESO Multi-conjugate Adaptive optics Demonstrator (MAD) is a prototype intended to be tested at the VLT Nasmyth focus. With its development raises the problem of calibration of an AO system composed of several correcting devices and wave front sensors. One part of this process is the calibration of the static aberrations of the system, always present in spite of the best efforts made during the design, the manufacturing of the optics and their alignment. In this paper we present a study to find an optimized way to correct for the static aberrations in the scientific FoV of an MCAO system. Thanks to images from the camera, the WF error in the FoV is computed, the contribution of several altitudes reconstructed, and finally projected on the deformable mirrors in order to compensate for the measured aberrations. This technique, inspired from the calibration of the static aberration of the system NAOS-CONICA, allows bringing the best quality to the scientific instrument fed by an MCAO system, by taking the most of the presence of correcting devices in the optical path.

The Multi-Atmospheric Phase screens and Stars (MAPS) instrument is a powerful tool that has been developed in the framework of the ESO Multi-conjugate Adaptive optics Demonstrator project (MAD). It allows emulating a 3D evolving Paranal-like atmosphere as well as up to 12 sources in a 2 arc minutes field of view, as seen at a Nasmyth focus of one of the VLT. It will be used to perform advanced laboratory tests on MAD before its shipment to Chile. In this paper we present the opto-mechanical design of MAPS. This one simulates the characteristics of the VLT focus and achieves a high Strehl Ratio over the whole Field of View in the visible as well as in the infrared. A curved entrance plate crowded with fibers emulates various stars configurations including real sky asterisms. In order to simulate the atmosphere, three rotating Phase Screens are placed in the beam and conjugated with different altitudes. Those are glass plates dig in their surface in a way that the beam passing through is distorted as it would be by an atmospheric turbulent layer. In this poster we also present the process of research that lead to the choice of a reliable technique to imprint the aberrations into the screens, their properties and expected performance.

The controller is one of the essential components of a multi-conjugate adaptive optics (MCAO) system. We present in this paper a preliminary comparison in performance based on numerical simulations of two simple control laws for a star-oriented MCAO configuration. The first control law is based on a TSVD reconstruction matrix and a constant-gain integrator, and the second one is based on an optimized modal gain integrator. These control laws will be validated experimentally with the Multi-conjugate Adaptive Optics Demonstrator (MAD).

The European Southern Observatory together with external research Institutes is building a Multi-Conjugate Adaptive Optics Demonstrator (MAD) to perform wide field of view adaptive optics correction. The aim of MAD is to demonstrate on the sky the feasibility of the MCAO technique and to evaluate all the critical aspects in building such kind of instrument in the framework of both the 2nd generation VLT instrumentation and the 100-m Overwhelmingly Large Telescope (OWL). The MAD module will be installed at one of the VLT unit telescope in Paranal to perform on-sky observations. MAD is based on a two deformable mirrors correction system and on two multi-reference wavefront sensors capable to observe simultaneously some pre-selected configurations of Natural Guide Stars. MAD is expected to correct up to 2 arcmin field of view in K band. MAD has just started the integration phase which will be followed up by a long period of testing. In this paper we present the final design of MAD with a brief report about the status of the integration.

The CAMCAO instrument is a high resolution near infrared (NIR) camera conceived to operate together with the new ESO Multi-conjugate Adaptive optics Demonstrator (MAD) with the goal of evaluating the feasibility of Multi-Conjugate Adaptive Optics techniques (MCAO) on the sky. It is a high-resolution wide field of view (FoV) camera that is optimized to use the extended correction of the atmospheric turbulence provided by MCAO. While the first purpose of this camera is the sky observation, in the MAD setup, to validate the MCAO technology, in a second phase, the CAMCAO camera is planned to attach directly to the VLT for scientific astrophysical studies. The camera is based on the 2kx2k HAWAII2 infrared detector controlled by an ESO external IRACE system and includes standard IR band filters mounted on a positional filter wheel. The CAMCAO design requires that the optical components and the IR detector should be kept at low temperatures in order to avoid emitting radiation and lower detector noise in the region analysis. The cryogenic system inclues a LN2 tank and a sptially developed pulse tube cryocooler. Field and pupil cold stops are implemented to reduce the infrared background and the stray-light. The CAMCAO optics provide diffraction limited performance down to J Band, but the detector sampling fulfills the Nyquist criterion for the K band (2.2mm).