7,734 research outputs found

    The role of GP’s compensation schemes in diabetes care: evidence from panel data

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    The design of incentive schemes that improve quality of care is a central issue for the healthcare sector. Nowadays we observe many pay-for-performance programs, where payment is contingent on meeting indicators of provider effort, but also other alternative strategies have been introduced, for example programs rewarding physicians for participation in diseases management plans. Although it has been recognised that incentive-based remuneration schemes can have an impact on GP behaviour, there is still weak empirical evidence on the extent to which such programs influence health outcomes. We investigate the impact of financial incentives in Regional and Local Health Authority contracts for primary care in the Italian Region Emilia Romagna for the years 2003-05. We focus on avoidable hospitalisations (Ambulatory Care Sensitive Conditions) for patients affected by type 2 diabetes mellitus, for which the assumption of responsibility and the adoption of clinical guidelines are specifically rewarded. We estimate a panel count data model using a Negative Binomial distribution to test the hypothesis that, other things equal, patients under the responsibility of GPs receiving a higher share of their income through these programs are less likely to experience avoidable hospitalisations. Our findings support the hypothesis that financial transfers may contribute to improve quality of care, even when they are not based on the ex-post verification of performances.

    Chaotic dynamics in a storage-ring Free Electron Laser

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    The temporal dynamics of a storage-ring Free Electron Laser is here investigated with particular attention to the case in which an external modulation is applied to the laser-electron beam detuning. The system is shown to produce bifurcations, multi-furcations as well as chaotic regimes. The peculiarities of this phenomenon with respect to the analogous behavior displayed by conventional laser sources are pointed out. Theoretical results, obtained by means of a phenomenological model reproducing the evolution of the main statistical parameters of the system, are shown to be in a good agreement with experiments carried out on the Super-ACO Free Electron Laser.Comment: submitted to Europ Phys. Journ.

    Affine parameterization of the dark sector: costraints from WMAP5 and SDSS

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    We study a set of universe models where the dark sector is described by a perfect fluid with an affine equation of state P=P0+αρP=P_0+\alpha \rho, focusing specifically on cosmological perturbations in a flat universe. We perform a Monte Carlo Markov Chain analysis spanning the full parameter space of the model using the WMAP 5 years data and the SDSS LRG4 survey. The affine fluid can either play the role of a unified dark matter (UDM), accounting for both dark matter and a cosmological constant, or work alongside cold dark matter (CDM), as a form of dark energy. A key ingredient is the sound speed, that depends on the nature of the fluid and that, for any given background model, adds a degree of freedom to the perturbations: in the barotropic case the square of the sound speed is simply equal to the affine parameter α\alpha; if entropic perturbations are present the effective sound speed has to be specified as an additional parameter. In addition to the barotropic case, we consider the two limiting cases of effective sound speed equal to 0 or 1. For α=cs2=0\alpha=c_s^2=0 our UDM model is equivalent to the standard Λ\LambdaCDM with adiabatic perturbations. Apart of a trivial subcase, all models considered satisfy the data constraints, with quite standard values for the usual cosmological parameters. In general our analysis confirms that cosmological datasets require both a collisionless massive and cold component to form the potential wells that lead to structure formation, and an effective cosmological constant that drives the late accelerated expansion.Comment: 10 pages, 9 figure

    Análise das estratégias de efeito no filme Koyaanisqatsi

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    In this essay, we try to figure out, based on Wilson Gomes’s filmanalysis methodology and on the musical minimalistic theory, which are the cognitive, sensorial, and emotional elements that are composed in the effect production strategies in the experimental film Koyaanisqatsi (Godfrey Reggio, USA, 1982)

    Hard - X-rays selected Active Galactic Nuclei. I. A radio view at high-frequencies

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    A thorough study of radio emission in Active Galactic Nuclei (AGN) is of fundamental importance to understand the physical mechanisms responsible for the emission and the interplay between accretion and ejection processes. High frequency radio observations can target the nuclear contribution of smaller emitting regions and are less affected by absorption. We present JVLA 22 and 45 GHz observations of 16 nearby (0.003\lez\le0.3) hard - X-rays selected AGN at the (sub)-kpc scale with tens uJy beam1^{-1} sensitivity. We detected 15/16 sources, with flux densities ranging from hundreds uJy beam1^{-1} to tens Jy (specific luminosities from \sim1020^{20} to \sim1025WHz1^{25}\,W\,Hz^{-1} at 22 GHz). All detected sources host a compact core, with 8 being core-dominated at either frequencies, the others exhibiting also extended structures. Spectral indices range from steep to flat/inverted. We interpret this evidence as either due to a core+jet system (6/15), a core accompanied by surrounding star formation (1/15), to a jet oriented close to the line of sight (3/15), to emission from a corona or the base of a jet (1/15), although there might be degeneracies between different processes. Four sources require more data to shed light on their nature. We conclude that, at these frequencies, extended, optically-thin components are present together with the flat-spectrum core. The LR/LX105{L_R}/{L_X}\sim10^{-5} relation is roughly followed, indicating a possible contribution to radio emission from a hot corona. A weakly significant correlation between radio core (22 and 45 GHz) and X-rays luminosities is discussed in the light of an accretion-ejection framework.Comment: Accepted for publication on MNRA

    Implementing Session Centered Calculi

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    Recently, specific attention has been devoted to the development of service oriented process calculi. Besides the foundational aspects, it is also interesting to have prototype implementations for them in order to assess usability and to minimize the gap between theory and practice. Typically, these implementations are done in Java taking advantage of its mechanisms supporting network applications. However, most of the recurrent features of service oriented applications are re-implemented from scratch. In this paper we show how to implement a service oriented calculus, CaSPiS (Calculus of Services with Pipelines and Sessions) using the Java framework IMC, where recurrent mechanisms for network applications are already provided. By using the session oriented and pattern matching communication mechanisms provided by IMC, it is relatively simple to implement in Java all CaSPiS abstractions and thus to easily write the implementation in Java of a CaSPiS process

    Application of the Ergun's Equation in Porous Ceramic Based on CaO-Stabilized ZrO2

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    AbstractThe study of the permeability in porous ceramics with potential application as filters is essential because this parameter includes a number of processing variables such as porosity and pore size of great importance in the development of porous media. The knowledge of the relationship between permeability and these variables, provide a better criterion to determine the process variables that result in an optimization of the permeability. The optimization of this parameter is a basic requirement for an adequate operation of the ceramic as a filter material. In this study, the permeability of porous ceramic prepared from different compositions of the mixture of ZrO2 and a high alumina cement with 30 wt% CaO and sintered at 1400 ¡ C was experimental and theoretically evaluated. Theoretical evaluation of permeablity was performed using the Ergun«s equation, which describes the permeability constant as a funtion of the porosity and mean pore size of the porous materia

    The role of leadership in a digitalized world: A review

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    Digital technology has changed organizations in an irreversible way. Like the movable type printing accelerated the evolution of our history, digitalization is shaping organizations, work environment and processes, creating new challenges leaders have to face. Social science scholars have been trying to understand this multifaceted phenomenon, however, findings have accumulated in a fragmented and dispersed fashion across different disciplines, and do not seem to converge within a clear picture. To overcome this shortcoming in the literature and foster clarity and alignment in the academic debate, this paper provides a comprehensive analysis of the contribution of studies on leadership and digitalization, identifying patterns of thought and findings across various social science disciplines, such as management and psychology. It clarifies key definitions and ideas, highlighting the main theories and findings drawn by scholars. Further, it identifies categories that group papers according to the macro level of analysis (e-leadership and organization, digital tools, ethical issues, and social movements), and micro level of analysis (the role of C-level managers, leader's skills in the digital age, practices for leading virtual teams). Main findings show leaders are key actors in the development of a digital culture: they need to create relationships with multiple and scattered stakeholders, and focus on enabling collaborative processes in complex settings, while attending to pressing ethical concerns. With this research, we contribute to advance theoretically the debate about digital transformation and leadership, offering an extensive and systematic review, and identifying key future research opportunities to advance knowledge in this field

    From radio-quiet to radio-silent: low luminosity Seyfert radio cores

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    A strong effort has been devoted to understand the physical origin of radio emission from low-luminosity AGN (LLAGN), but a comprehensive picture is still missing. We used high-resolution (\le1 arcsec), multi-frequency (1.5, 5.5, 9 and 14 GHz) NSF's Karl G. Jansky Very Large Array (VLA) observations to characterise the state of the nuclear region of ten Seyfert nuclei, which are the faintest members of a complete, distance-limited sample of 28 sources. With the sensitivity and resolution guaranteed by the VLA-A configuration, we measured radio emission for six sources (NGC3185, NGC3941, NGC4477, NGC4639, NGC4698 and NGC4725), while for the remaining four (NGC0676, NGC1058, NGC2685 and NGC3486) we put upper limits at tens uJy/beam level, below the previous 0.12 mJy/beam level of Ho&Ulvestad (2001), corresponding to luminosities down to L1019\le10^{19} W/Hz at 1.5 GHz for the highest RMS observation. Two sources, NGC4639 and NGC4698, exhibit spectral slopes compatible with inverted spectra (α\alpha\le0, SνναS_{\nu}\,\propto\,{\nu}^{-\alpha}), hint for radio emission from an optically-thick core, while NGC4477 exhibits a steep (+0.52±\pm0.09) slope. The detected sources are mainly compact on scales \le arcseconds, predominantly unresolved, except NGC3185 and NGC3941, in which the resolved radio emission could be associated to star-formation processes. A significant X-ray - radio luminosities correlation is extended down to very low luminosities, with slope consistent with inefficient accretion, expected at such low Eddington ratios. Such sources will be one of the dominant Square Kilometre Array (SKA) population, allowing a deeper understanding of the physics underlying such faint AGN.Comment: accepted for publication on MNRAS (19 pages, 26 figures
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