23 research outputs found

    LBT AO system: tests and calibration

    Get PDF
    An Adaptive Optic (AO) system is a fundamental requirement of 8m-class telescopes. We know that in order to obtain the maximum possible resolution allowed by these telescopes we need to correct the atmospheric turbulence. Thanks to adaptive optic systems we are able to use all the effective potential of these instruments, drawing all the information from the universe sources as best as possible. In an AO system there are two main components: the wavefront sensor (WFS) that is able to measure the aberrations on the incoming wavefront in the telescope, and the deformable mirror (DM) that is able to assume a shape opposite to the one measured by the sensor. The two subsystem are connected by the reconstructor (REC). In order to do this, the REC requires a “common language" between these two main AO components. It means that it needs a mapping between the sensor-space and the mirror-space, called an interaction matrix (IM). Therefore, in order to operate correctly, an AO system has a main requirement: the measure of an IM in order to obtain a calibration of the whole AO system. The IM measurement is a 'mile stone' for an AO system and must be done regardless of the telescope size or class. Usually, this calibration step is done adding to the telescope system an auxiliary artificial source of light (i.e a fiber) that illuminates both the deformable mirror and the sensor, permitting the calibration of the AO system. For large telescope (more than 8m, like Extremely Large Telescopes, ELTs) the fiber based IM measurement requires challenging optical setups that in some cases are also impractical to build. In these cases, new techniques to measure the IM are needed. In this PhD work we want to check the possibility of a different method of calibration that can be applied directly on sky, at the telescope, without any auxiliary source. Such a technique can be used to calibrate AO system on a telescope of any size. We want to test the new calibration technique, called “sinusoidal modulation technique”, on the Large Binocular Telescope (LBT) AO system, which is already a complete AO system with the two main components: a secondary deformable mirror with by 672 actuators, and a pyramid wavefront sensor. My first phase of PhD work was helping to implement the WFS board (containing the pyramid sensor and all the auxiliary optical components) working both optical alignments and tests of some optical components. Thanks to the “solar tower” facility of the Astrophysical Observatory of Arcetri (Firenze), we have been able to reproduce an environment very similar to the telescope one, testing the main LBT AO components: the pyramid sensor and the secondary deformable mirror. Thanks to this the second phase of my PhD thesis: the measure of IM applying the sinusoidal modulation technique. At first we have measured the IM using a fiber auxiliary source to calibrate the system, without any kind of disturbance injected. After that, we have tried to use this calibration technique in order to measure the IM directly “on sky”, so adding an atmospheric disturbance to the AO system. The results obtained in this PhD work measuring the IM directly in the Arcetri solar tower system are crucial for the future development: the possibility of the acquisition of IM directly on sky means that we are able to calibrate an AO system also for extremely large telescope class where classic IM measurements technique are problematic and, sometimes, impossible. Finally we have not to forget the reason why we need this: the main aim is to observe the universe. Thanks to these new big class of telescopes and only using their full capabilities, we will be able to increase our knowledge of the universe objects observed, because we will be able to resolve more detailed characteristics, discovering, analyzing and understanding the behavior of the universe components

    Dentoalveolar Effects Following Maxillary Expansion: Comparison Between Dental and Skeletal Anchorage

    Get PDF
    Objective: To compare the dento-alveolar effects between dental and skeletal anchored expansion devices to achieve maxillary expansion in different groups of patients: pure dental anchorage was used in growing patients and skeletal anchorage in adult patients. Linear, angular and volumetric parameters have been analysed. Material and Methods: 22 patients has been selected from the total archive of patients treated in the Orthodontics Department of the University of Ferrara, Italy, divided into 3 groups according to the appliance used to obtain the transversal maxillary correction. Digital files of the upper arch were obtained from scans performed using an intro-oral scanner before treatment (T0) and at the end of expansion (T1). Therefore, linear, angular and volumetric measurements have been performed. Results: There is a highly significant statistic variation of the 3-3, 4-4 and 6-6 diameter as a function of time. There was a statistically significant variation of the palatal vault angle and of the 6-6 distance at the cusp level as a function of time. Moreover, it appears that these parameters are reduced in the group with skeletal anchored expander. No tooth considered have encountered a statistically significant change in tip and torque values, no matter the type of RPE and the treatment time. For all patients, we have recorded the superimposition of the maxillary dental cast before and after treatment. Conclusion: In all patients, we obtained a resolution of the maxillary transverse deficit. Patients treated by pure skeletal anchored devices have recorded a less variations of palatal vault angle and the distance between first molar cusps, as if the expansion was gained more parallel. The expansion obtained showed reduced dental side effects, as tip and torque values haven’t changed in a statistically significant way

    IMPACT ASSESSMENT OF AN EDUCATION COURSE ON VACCINATIONS IN A POPULATION OF PREGNANT WOMEN

    Get PDF
    BackgroundAlthough benefits of vaccinations have been extensively demonstrated, poor knowledge of the population has resulted in non-optimal vaccine coverage as a result of the hesitancy and negative perception of many parents toward vaccination. Materials and MethodsTo assess the impact of a course on the knowledge and attitudes of future mothers on vaccination, 214 pregnant women participated in a research project undertaken at the Obstetrics and Gynaecology Department of the Careggi University Hospital in Florence (Italy). This involved completion of anonymous questionnaires administered before and after the intervention. A descriptive and statistical analysis was carried out on the results of the collected data by performing comparative evaluations of the responses obtained before and after the intervention. ResultsThere was good adherence to the initiative (98%): the sample population was initially not hostile to vaccines, albeit poorly or insufficiently informed (43%). The educational intervention had a positive impact, especially as a vaccine information tool and for correctly addressing the vaccine hesitancy. After the intervention, women who considered their level of knowledge about vaccines as poor or insufficient were reduced by 30% and the "hesitant" ones were reduced with respect to all aspects of the study, especially about the decision to be vaccinated during pregnancy. ConclusionsHesitancy finds its roots in the absence of accurate information. Healthcare professionals need to improve their communication skills. Competent education delivered during pregnancy, when women are more receptive, may have a highly positive impact. These observations will have to be considered in the planning of delivery preparation courses

    The right to food, food donation and microbiological problems of food safety: an experience in the territory of Florence

    Get PDF
    Aim. The aim of this study is to understand whether the freezing without a rapid blast chiller represents a storage method for food at the end of shelf life that guarantees microbiological food safety, so to be considered an effective tool for the appropriate management of food in charitable organizations. Methods. The study has been performed on 90 food samples, among those that a charitable foodservice trust receives by the large-scale distribution. The products have been frozen using a domestic refrigerator. The indicators used were: total aerobic microbial count, Escherichia coli, Salmonella spp, Staphylococcus aureus, Campylobacter spp, sulphite reducing clostridia. Results. The results show that the preservation of the chosen fresh products at the end of shelf life in refrigerators, frozen without the use of chillers, is a potential management strategy to avoid the loss of edible food, while maintaining the safety standards.

    Application of socio-economic-health deprivation index, analysis of mortality and influenza vaccination coverage in the elderly population of Tuscany.

    Get PDF
    ObjectiveThe aim of this paper is to describe the results obtained from the application of a specific local deprivation index, calculated on the basis of 2011 Census sections, to general and cause-specific mortality and influenza vaccination coverage among elderly people of the municipality of Florence.MethodsGeneral and cause-specific mortality data (2009-2013) and influenza vaccination coverage data (2015/16 and 2016/17) have been collected for subjects aged ≥65 years residing in the municipality of Florence (Tuscany), at the 2011 Census section level. Socio-Economic and Health Deprivation Index (SEHDI) has been constructed and validated by using socio-economic indicators and mortality ratios.ResultsHalf the Florence population belongs to the medium deprivation group; about 25% belongs to the two most deprived groups, and the remaining 25% is wealthy. Elderly people mostly belong to the high deprivation group. All-cause mortality and cause-specific mortality (cancer and respiratory diseases) reach the highest values in the high deprivation group.Influenza vaccination coverage (VC) is 54.7% for the seasons 2015/16 and 2016/17, combined. VC shows a growing linear trend as deprivation increases. VC appears to be correlated with different factors in the different deprivation groups.ConclusionsSocio-economic deprivation plays an important role in health choices, so the application of SEHDI allows to identify the characteristics of the main sub-groups of the population with a low adherence to influenza vaccination. Results of the present study should be spread to General Practitioners in order to help them to promote influenza vaccination to their patients

    Do Tuscan people adhere to meningococcal C vaccination during an emergency campaign?

    Get PDF
    Introduction: Tuscany region (Italy) recorded a rise in the number of meningococcal disease cases between January 2015 and February 2016,(52 cases) compared to 2014(16 cases). The aim of this study was to describe the emergency meningococcal C (MenC) vaccination programme in Tuscany and the population’s adherence to the activities performed in the Local Health Unit (LHU) of Florence.Methods:The MenC vaccination programme and the planning of the prevention and communication activities were analysed in the LHU of Florence. As an indicator of population’s adherence, the vaccination coverage (VC)during the emergency campaignwas investigated and adverse drug reactions (ADR) surveillance was reported.Results:The communication campaign included a dedicated toll-free telephone number, press releases (newspapers, radio, television, websites), and informative letters addressed to mayors, secondary schools, and sports associations. Citizens aged 11–20 years were the primary target of the campaign. Due to the high incidence of cases among older people, the vaccination was extended to subjectsover 45 years. The population’s adherence to the vaccination campaignwas satisfactory: VC reached 47.1%for the primary target. The ADR reporting rate (3.1/10,000) on meningococcal disease in our study confirmed the safety of the vaccination.Conclusions:In 2017, only 10 IMD cases were reported, suggesting the effectiveness of the immunization campaign. Similar VC during emergency MenC vaccination programmes have been reached in other Italian regions and other EU countries, too.The achievement of greater vaccination coverage is restricted by a sentiment of hesitancy towards vaccines among the general population
    corecore