Chemical evolution models with a new stellar nucleosynthesis

Numerical models for the chemical evolution of the Galaxy have been computed with the new stellar yields published by Maeder (1992). These metallicity dependent yields represent an important improvement in the chemical evolution of galaxies but there are still uncertainties in the stellar evolution which prevent completely satisfactory results. {}From the comparison of the model predictions with the corresponding observational constraints we find that Maeder's nucleosynthesis reproduces the oxygen and carbon abundances and provides consistent $\Delta$Y/$\Delta$(O/H) ratios if a significant amount of gas is accreted by the galactic disc during its whole lifetime. The lower mass limit for the black hole formation (M$_{bh}$) must be larger than 22.5 M$_{\odot}$ to avoid oxygen underproduction.Comment: 6 pages, MNRAS LaTex style, figures available on request from [email protected]

Control Driven Scaling Effects of Motor and Rotors for Urban Air Mobility Design

Through this thesis research the problem of controllability and propulsion associated with scaling-up consumer drones to vehicles that may carry significantly larger payloads, including passenger will be analyzed and tested. Controllability is mainly compromised due to the increasing response time of a larger rpm controlled rotor. This requires a more powerful motor, which translates into heavier and larger devices compromising the thrust-to-weight ratio. Collective pitch control at constant rpm is proposed as a first approach to mitigate the controllability problem, and it is tested in a MATLAB Simulink environment. This solution, linked to a Non-linear Dynamic Inversion controller, is simulated as part of the Personal Aerial Vehicle Embry-Riddle aircraft, which serves as test bed. The simulation includes the electric motor, rotor and aircraft mathematical models, which are developed in this research. Included in this thesis are motor sizing and weigh analysis as well as a thrust-to-weight ratio study, which allows to identify the scaling-up effects in consumer drones\u27 propulsion plant. This portion of the thesis is closely linked to the behavior displayed in the simulation, which leads to conclude that collective pitch control at constant rpm can mitigate controllability drawbacks. However, due to the size and weight of electric motors increasing very rapidly, it is demonstrated that, while it is possible to obtain an optimal solution where controllability and thrust-to-weight ratio are in balance, scaling-up consumer drones is a highly complex and limited task

La rappresentazione del rapporto tra utenti e sistema sanitario: I modelli culturali dei medici di medicina generale - The representation of the relationship between users and healthcare system: Cultural models of general practitioners

The present research study explores the emotional and symbolic representation of the Italian healthcare system and specifically of general medical services reported by a group of Italian general practitioners. General medicine is recently affected by a structural change which could be sustained also by a cultural revolution, however this revolution seems to be oriented to expected values without a clear methodology which promotes and accompanies this cultural change. The present study deals with the lack of practices due to these unrealized expected values and assumes that for intervening it is necessary knowing the existing culture before thinking to change it. Interviews to 36 general practitioners were analyzed by Emotional Text Analysis (AET). Results highlight a factorial space characterized by five clusters. According to respondents’ perspective, healthcare problems refer to two large issues characterized by powerlessness of general practitioners to intervene. On the one hand, there is health emergency, dealt with by first aid and emergency medicine. On the other hand, there is chronicity, especially affecting the elderly, which is dealt with by other workers (nurses, private family assistants, social workers) who care patients at home and replace physicians. The general practitioners’ work is difficult because of many different reasons; but the central theme is the lack of absolute power – based on morality and consciousness – which leads to the perception of catastrophic consequences for medical profession and the physician-patient relationship. Often, general practitioners are in their offices and are not able to go to patients’ home, therefore they cannot create care relationships based on trust and dependence which allow useful and trustworthy interventions. In sum, the core theme emerging from data refers to the general practitioners’ perceived lack of personal and trust-based relationships with patients

La relazione che organizza il contesto sanitario: domanda dell’utenza e risposta dei servizi sanitari, nel territorio e nell’ospedale - The relationship which organizes the healthcare context: users’ demand and response of healthcare services, in the territory and the hospital

Our intent is to present citizens’ demand of health care services in Italy through a research structured in three studies. We used the Emotional Text Analysis (ETA) to lead the three s tudies: the first study regarded the citizens’expectations of the healthcare services, the second study regarded the point of view of the hospital personnel (medical doctors and nurses), the third regarded the point of view of the General Practitioners onthe health care services. These three studies are briefly presented. Data and outcome of an Assumed Similarity Test applied to all experimental subjects of the three studies in order to make a comparison among them, are also presented. The findings of the Emotional Text Analysis show that citizens, potential users of health services, center their requests on their individual subjectivity, and seek answers both to their suffering and to the feeling of alienation that characterizes the being sick feeling that makes them go to a medical doctor. For their part, general practitioners and hospital doctors immediately transform this subjective feeling in an objective medical diagnosis. Here a first gap emerges between patient’s demand and medical response, leavingthe possibility of an alliance on the diagnosis in order to jointly fight the disease. It has long been in place though a change that has expelled the patient also from sharing the diagnostic process, increasingly taken from self-centered dynamics within the healthcare system. This widens the gap between the request of the citizens and the response of the health services, that contributes to that conflictual growth to which defensive medicine gives a dysfunctional answer. The Assumed Similarity Test contributes to the interpretation of the health care dynamic identified in the Emotional Text Analysis; particularly in regard to the unfolding conflict, given by the hypothesis emerging from the data analysis, that a feeling of closeness for the hospital personnel goes along with an emotional stance of overpowering the othe

Robustness Evaluation of Computer-aided Clinical Trials for Medical Devices

Medical cyber-physical systems, such as the implantable cardioverter defibrillator (ICD), require evaluation of safety and efficacy in the context of a patient population in a clinical trial. Advances in computer modeling and simulation allow for generation of a simulated cohort or virtual cohort which mimics a patient population and can be used as a source of prior information. A major obstacle to acceptance of simulation results as a source of prior information is the lack of a framework for explicitly modeling sources of uncertainty in simulation results and quantifying the effect on trial outcomes. In this work, we formulate the Computer-Aided Clinical Trial (CACT) within a Bayesian statistical framework allowing explicit modeling of assumptions and utilization of simulation results at all stages of a clinical trial. To quantify the robustness of the CACT outcome with respect to a simulation assumption, we define δ-robustness as the minimum perturbation of the base prior distribution resulting in a change of the CACT outcome and provide a method to estimate the δ-robustness. We demonstrate the utility of the framework and how the results of δ-robustness evaluation can be utilized at various stages of a clinical trial through an application to the Rhythm ID Goes Head-to-head Trial (RIGHT), which was a comparative evaluation of the safety and efficacy of specific software algorithms across different implantable cardiac devices. Finally, we introduce a hardware interface that allows for direct interaction with the physical device in order to validate and confirm the results of a CACT for implantable cardiac devices

Virtual Flight Demonstration of the Stratospheric Dual-Aircraft Platform

A baseline configuration for the dual-aircraft platform (DAP) concept is described and evaluated in a physics-based flight dynamics simulations for two month-long missions as a communications relay in the lower stratosphere above central Florida, within 150-miles of downtown Orlando.The DAP configuration features two large glider-like (130 ft wing span) unmanned aerial vehicles connected via a long adjustable cable (total extendible length of 3000 ft) which effectively sail without propulsion using available wind shear. Use of onboard LiDAR wind profilers to forecast wind distributions are found to be necessary to enable the platform to efficiently adjust flight conditions to remain sailing by finding sufficient wind shear across the platform. The aircraft derive power from solar cells, like a conventional solar aircraft, but also extract wind power using the propeller as a turbine when there is an excess of wind shear available.Month-long atmospheric profiles (at 3-5 min intervals) in the vicinity of 60,000-ft are derived from archived data measured by the 50-Mhz Doppler Radar Wind Profiler at Cape Canaveral and used in the DAP flight simulations. A cursory evaluation of these datasets show that sufficient wind shear for DAP sailing is persistent, suggesting that DAP could potentially sail over 90% of the month-long durations even when limited by modest ascent/descent rates.DAP's novel guidance software uses a non-linear constrained optimization technique to define waypoints such that sailing mode of flight is maintained where possible, and minimal thrust is required where sailing is not practical. A set of constraints are identified which result in waypoints that enable efficient flight (i.e., minimal use of propulsion) over the two month-long flight simulations. Waypoint solutions may need to be tabulated for a wide range of potential atmospheric conditions and stored onboard for quick retrieval on a real DAP.DAP's flight control software uses an unconventional mixture of spacecraft and aircraft control techniques. Flight simulations confirms that this controls approach enables the platform to consistently reach successive waypoints over the month-long flight simulations.The ability of DAP to transition between the sailing mode (i.e., cable tension is high) and standard formation flight (i.e., cable tension is low) is a vital capability (e.g., to enable intermittent turns while stationkeeping). A new method to perform these transitions has been identified and characterized with flight simulation which requires special aircraft modifications.The energy-usage of the DAP configuration during two month-long stationkeeping missions over central Florida (i.e., stationkeeping over Orlando) is evaluated and compared to that of a pure solar aircraft of the same weight and aerodynamic performance. DAP is shown to consistently reduce net propulsion usage while simultaneously increasing solar energy capture.A baseline 700 GHz communications system is described and its performance evaluated for the proposed mission over central Florida. It is found that the variable roll orientation of the aircraft would increase the power required to maintain coverage over the stationkeeping radius of 150 miles (e.g., by as much as 100% when DAP is 150 miles from Orlando), compared to level flight. This effect can be mitigated via additional antenna design complexity or a more restricted stationkeeping radius

Breast implant associated anaplastic large cell lymphoma. proposal for a monitoring protocol

BACKGROUND: The authors report four cases of breast implant-associated anaplastic large cell lymphoma (ALCL) from a single institution and propose a multidisciplinary protocol. METHODS: From 2012 to 2014, four breast implant-associated ALCL cases were diagnosed. The authors performed the original operation, and no patients were referred to their practice. Cases 1, 2, and 4 were CD4/CD30/ALK ALCL with previous textured-implant reconstruction, whereas case 3 was CD8/CD30/ALK ALCL with previous polyurethane-implant augmentation. A retrospective study of all patients who underwent breast implant positioning was performed to identify any misdiagnosed cases. RESULTS: Of 483 patients, 226 underwent reconstruction with latissimus dorsi flap and prosthesis, 115 had skin-sparing/nipple-sparing mastectomy and prosthesis, 117 underwent an expander/implant procedure, and 25 underwent breast augmentation. Fifty-eight cases (12 percent) underwent implant replacement for capsular contracture, 15 (3.1 percent) experienced late-onset seroma, and four (0.83 percent) had both capsular contracture and seroma. Seventy-seven symptomatic patients (16 percent) underwent surgical revision (capsulectomy/capsulotomy) and/or seroma evacuation. The second look on histologic specimens did not identify misdiagnosed cases. A multidisciplinary protocol for suspected implant-associated ALCL was established. Ultrasound and cytologic examinations are performed in case of periprosthetic effusion. If implant-associated ALCL is diagnosed, implant removal with capsulectomy is performed. If disseminated disease is detected through positron emission tomography/computed tomography of the total body, the patient is referred to the oncology department. CONCLUSIONS: A multidisciplinary protocol is mandatory for both early diagnosis and patient management. Until definitive data emerge regarding the exact etiopathogenesis of breast implant-associated ALCL, the authors suggest offering only autologous reconstruction if patients desire it

Portuguese hospital anxiety and depression scale (HADS): Usefulness in focal epilepsy

Objective: To explore the usefulness of the Portuguese HADS for outpatients with focal epilepsy. Methods: Ninety-nine outpatients were assessed using a socio-demographic and clinical questionnaire, the MHI-5, and the HADS (individual interview). Results: HADS proved to be understandable and well accepted by patients, with alpha ranges from 0.72 to 0.82. It also correlated with MHI-5 and some demographic and clinical variables. Conclusions: The results support the use of the Portuguese HADS as a screening tool for these patients (facial validity; internal consistency; construct validity), though the associations between HADS scores and some demographic and clinical variables question its validity. The results underscore the importance of assessing patient affective status, as anxiety and depression are common and provide additional insight into the association of anxiety/depression with certain demographic and clinical variables. The reasons for the inconsistencies between these results and published literature should be explored in future studies. © Internet Scientific Publications, LLC., 1996 to 2010