La Corporate Governance in Ungheria: il Modello Dualistico e la Budapest Stock Exchange

Il presente lavoro consiste nell’analisi della corporate governance ed in particolare del modello di amministrazione e controllo di tipo dualistico in un Paese che ha risentito in modo esemplare delle vicende storiche legate al disfacimento dell’ex impero sovietico alla fine degli anni ‘80, l’Ungheria. Il passaggio da un sistema ad economia pianificata al capitalismo ha comportato una serie di riforme sostanziali e incisive che necessitavano dell’afflusso di capitali esteri. Ciò ha reso indispensabile per le aziende l’adozione di pratiche di buon governo societario per incentivare la partecipazione degli investitori internazionali al capitale di rischio e di prestito. Sono stati emanati una serie di codici di condotta e il contributo di maggior rilevanza è stato quello fornito dalla Budapest Stock Exchange, le cui Raccomandazioni devono essere rispettate o, in caso di mancata adesione, adeguatamente giustificate dalle società quotate. Il capitolo 1 illustra i motivi del crollo del blocco sovietico e lo scenario economico e politico ungherese prima e dopo le consistenti opere di riforma avvenute nel periodo della “transizione”. Il capitolo 2 riguarda le caratteristiche tipiche del modello di amministrazione e controllo prevalente in Ungheria, il dualistico di stampo tedesco. Vengono evidenziati gli organi societari del modello in base sia alla normativa che secondo le best practice. Infine, vengono esaminate le differenze esistenti fra la Germania e l’Ungheria, riguardanti ad esempio il tema della rappresentanza dei lavoratori nei consigli di sorveglianza, che rappresenta il fulcro del modello tedesco e che invece riveste un ruolo soltanto marginale in Ungheria. Il capitolo 3 descrive l’andamento del mercato dei capitali ungherese, l’evoluzione della Budapest Stock Exchange e il Gruppo di cui fa parte, il Central Eastern Europe Exchange Group (CEESEG). Il capitolo 4 è dedicato all’analisi della governance nelle tre maggiori società quotate ungheresi (per capitalizzazione) evidenziandone similitudini, differenze e criticità

Suprathermal electrons at Saturn's bow shock

The leading explanation for the origin of galactic cosmic rays is particle acceleration at the shocks surrounding young supernova remnants (SNRs), although crucial aspects of the acceleration process are unclear. The similar collisionless plasma shocks frequently encountered by spacecraft in the solar wind are generally far weaker (lower Mach number) than these SNR shocks. However, the Cassini spacecraft has shown that the shock standing in the solar wind sunward of Saturn (Saturn's bow shock) can occasionally reach this high-Mach number astrophysical regime. In this regime Cassini has provided the first in situ evidence for electron acceleration under quasi-parallel upstream magnetic conditions. Here we present the full picture of suprathermal electrons at Saturn's bow shock revealed by Cassini. The downstream thermal electron distribution is resolved in all data taken by the low-energy electron detector (CAPS-ELS, <28 keV) during shock crossings, but the higher energy channels were at (or close to) background. The high-energy electron detector (MIMI-LEMMS, >18 keV) measured a suprathermal electron signature at 31 of 508 crossings, where typically only the lowest energy channels (<100 keV) were above background. We show that these results are consistent with theory in which the "injection" of thermal electrons into an acceleration process involves interaction with whistler waves at the shock front, and becomes possible for all upstream magnetic field orientations at high Mach numbers like those of the strong shocks around young SNRs. A future dedicated study will analyze the rare crossings with evidence for relativistic electrons (up to ~1 MeV).Comment: 22 pages, 5 figures. Accepted for publication in Ap

Parameterization of the Angular Distribution of Gamma Rays Produced by p-p Interaction in Astronomical Environment

We present the angular distribution of gamma rays produced by proton-proton interactions in parameterized formulae to facilitate calculations in astrophysical environments. The parameterization is derived from Monte Carlo simulations of the up-to-date proton-proton interaction model by Kamae et al. (2005) and its extension by Kamae et al. (2006). This model includes the logarithmically rising inelastic cross section, the diffraction dissociation process and Feynman scaling violation. The extension adds two baryon resonance contributions: one representing the Delta(1232) and the other representing multiple resonances around 1600 MeV/c^2. We demonstrate the use of the formulae by calculating the predicted gamma-ray spectrum for two different cases: the first is a pencil beam of protons following a power law and the second is a fanned proton jet with a Gaussian intensity profile impinging on the surrounding material. In both cases we find that the predicted gamma-ray spectrum to be dependent on the viewing angle.Comment: 8 pages, 7 figures, figure 7 updated, accepted for publication in ApJ, text updated to match changes by the editor, two refs updated from preprints to full journal

Serendipitous discovery of an extended X-ray jet without a radio counterpart in a high-redshift quasar

A recent Chandra observation of the nearby galaxy cluster Abell 585 has led to the discovery of an extended X-ray jet associated with the high-redshift background quasar B3 0727+409, a luminous radio source at redshift z=2.5. This is one of only few examples of high-redshift X-ray jets known to date. It has a clear extension of about 12", corresponding to a projected length of ~100 kpc, with a possible hot spot located 35" from the quasar. The archival high resolution VLA maps surprisingly reveal no extended jet emission, except for one knot about 1.4" from the quasar. The high X-ray to radio luminosity ratio for this source appears consistent with the $\propto (1+z)^{4}$ amplification expected from the inverse Compton radiative model. This serendipitous discovery may signal the existence of an entire population of similar systems with bright X-ray and faint radio jets at high redshift, a selection bias which must be accounted for when drawing any conclusions about the redshift evolution of jet properties and indeed about the cosmological evolution of supermassive black holes and active galactic nuclei in general

Suzaku X-ray Imaging of the Extended Lobe in the Giant Radio Galaxy NGC6251 Associated with the Fermi-LAT Source 2FGLJ1629.4+8236

We report the results of a Suzaku X-ray imaging study of NGC6251, a nearby giant radio galaxy with intermediate FR I/II radio properties. Our pointing direction was centered on the gamma -ray emission peak recently discovered with Fermi-LAT around the position of the north-west radio lobe 15 arcmin offset from the nucleus. After subtracting two "off-source" pointings adjacent to the radio lobe, and removing possible contaminants in the XIS field of view, we found significant residual X-ray emission most likely diffuse in nature. The spectrum of the excess X-ray emission is well fit by a power law with photon index \Gamma = 1.90 +- 0.15 and a 0.5 - 8 keV flux of 4 x 10^{-13} erg cm^{-2} s^{-1}. We interpret this diffuse X-ray emission component as being due to inverse-Compton up-scattering of the cosmic microwave background photons by ultrarelativistic electrons within the lobe, with only a minor contribution from the beamed emission of the large-scale jet. Utilizing archival radio data for the source, we demonstrate by means of broad-band spectral modeling that the -ray flux of the Fermi-LAT source 2FGL J1629.4+8236 may well be accounted for by the high-energy tail of the inverse-Compton continuum of the lobe. Thus, this claimed association of gamma-rays from the north-west lobe of NGC6251, together with the recent Fermi-LAT imaging of the extended lobes of Centaurus A, indicates that particles may be efficiently (re-)accelerated up to ultrarelativistic energies within extended radio lobes of nearby radio galaxies in general.Comment: 19 pages, 4 figures, accepted for publication in the Ap

BL Lac Contribution to the Extragalactic Gamma-Ray Background

Very high energy gamma-rays from blazars traversing cosmological distances through the metagalactic radiation field can convert into electron-positron pairs in photon-photon collisions. The converted gamma-rays initiate electromagnetic cascades driven by inverse-Compton scattering off the microwave background photons. Using a model for the time-dependent metagalactic radiation field consistent with all currently available far-infrared-to-optical data, we calculate the cascade contribution from faint, unresolved high- and low-peaked blazars to the extragalactic gamma-ray background as measured by EGRET. For low-peaked blazars, we adopt a spectral index consistent with the mean spectral index of EGRET detected blazars, and the luminosity function determined by Chiang and Mukherjee (1998). For high-peaked blazars, we adopt template spectra matching prototype sources observed with air-Cherenkov telescopes up to 30 TeV, and a luminosity function based on X-ray measurements. The low number of about 20 for nearby high-peaked blazars with a flux exceeding 10^-11 cm^-2 s^-1 above 300 GeV inferred from the luminosity function is consistent with the results from air-Cherenkov telescope observations. Including the cascade emission from higher redshifts, the total high-peaked blazar contribution to the observed gamma-ray background at GeV energies can account up to about 30.Comment: 8 pages, 7 figures, accepted by A&A, final versio

Don’t Kick the Habit: The Role of Dependency in Habit Formation Apps

Habit formation apps are intended to help instigate and maintain new behaviors. Prior research has established that these apps mostly do not support the theoretical ‘habit’ construct defined in psychology, yet are generally popular and well reviewed in app stores. This apparent mismatch between theory and ‘in-the-wild’ usage has not been investigated to date. Through an in-depth qualitative study of a popular application Lift, this research establishes that common techniques such as reminders and streaks are effective at supporting repetition of new behaviors, but at the same time create a dependency: on-going app use is often required to achieve lasting change. This dependency introduces fragility in users’ attempts to change their behavior, as they often abandon the app and subsequently disengage with their new behaviors

On the Merging Cluster Abell 578 and Its Central Radio Galaxy 4C +67.13

Here we analyze radio, optical, and X-ray data for a peculiar cluster Abell 578. This cluster is not fully relaxed and consists of two merging sub-systems. The brightest cluster galaxy, CGPG 0719.8+6704, is a pair of interacting ellipticals with projected separation $\sim$10 kpc, the brighter of which hosts the radio source 4C +67.13. The Fanaroff-Riley type-II radio morphology of 4C +67.13 is unusual for central radio galaxies in local Abell clusters. Our new optical spectroscopy revealed that both nuclei of the CGPG 0719.8+6704 pair are active, albeit at low accretion rates corresponding to the Eddington ratio $\sim10^{-4}$ (for the estimated black hole masses of $\sim 3 \times 10^8\,M_\odot$ and $\sim 10^9 \, M_\odot$). The gathered X-ray ({\it Chandra}) data allowed us to confirm and to quantify robustly the previously noted elongation of the gaseous atmosphere in the dominant sub-cluster, as well as a large spatial offset ($\sim 60$\,kpc projected) between the position of the brightest cluster galaxy and the cluster center inferred from the modeling of the X-ray surface brightness distribution. Detailed analysis of the brightness profiles and temperature revealed also that the cluster gas in the vicinity of 4C\,+67.13 is compressed (by a factor of about $\sim 1.4$) and heated (from $\simeq 2.0$\,keV up to 2.7\,keV), consistent with the presence of a weak shock (Mach number $\sim 1.3$) driven by the expanding jet cocoon. This would then require the jet kinetic power of the order of $\sim 10^{45}$\,erg\,s$^{-1}$, implying either a very high efficiency of the jet production for the current accretion rate, or a highly modulated jet/accretion activity in the system.Comment: 12 pages, 11 figures, accepted for publication in Ap

Complex Structure of the Eastern Lobe of the Pictor A Radio Galaxy: Spectral Analysis and X-ray/Radio Correlations

Here we present detailed analysis of the distinct X-ray emission features present within the Eastern radio lobe of the Pictor A galaxy, around the jet termination region, utilising the data obtained from the Chandra X-ray Observatory. Various emission features have been selected for the study based on their enhanced X-ray surface brightness, including five sources that appear point-like, as well as three extended regions, one characterised by a filamentary morphology. For those, we perform a basic spectral analysis within the 0.5-7keV range. We also investigate various correlations between the X-ray emission features and the non-thermal radio emission, utilising the high-resolution radio maps from the Very Large Array at GHz frequencies. The main novel findings following from our analysis, regard the newly recognized bright X-ray filament located upstream of the jet termination region, extending for at least thirty kiloparsec (projected), and inclined with respect to the jet axis. For this feature, we observe a clear anti-correlation between the X-ray surface brightness and the polarized radio intensity, as well as a decrease in the radio rotation measure with respect to the surroundings. We speculate on the nature of the filament, in particular addressing a possibility that it is related to the presence of a hot X-ray emitting thermal gas, only partly mixed with the non-thermal radio/X-ray emitting electrons within the lobe, combined with the reversals in the lobe's net magnetic field.Comment: Final version, accepted for publication in The Astrophysical Journa

Design Considerations for the Integrated Delivery of Cognitive Behavioral Therapy for Depression: A User-Centered Design Study

Background: Adherence to computerized cognitive behavioral therapy (cCBT) programs in real-world settings can be poor, and in the absence of therapist support, effects are modest and short term. Moreover, because cCBT systems tend toward limited support and thus low-intensity treatment, they are typically most appropriate for people experiencing mild to moderate mental health difficulties. Blended therapy, that is, combining direct therapist contact with cCBT or psychoeducational materials, has been identified as one possible approach to address these limitations and widen access to individual CBT for depression. Building on the initial success of blended therapy, we explore an integrated approach that seeks to seamlessly combine face-to-face contact, electronic contact, and between-session activities. Integration also considers how the technology can support therapists’ workflow and integrate with broader health care systems. The ultimate aim is to provide a structure within which therapists can deliver high-intensity treatments, while also greatly reducing face-to-face contact. Objective: The research aimed to explore patients’ and therapists’ views on using a system for the delivery of individual treatment for depression that integrates face-to-face therapist contact with access to online resources and with synchronous online therapy sessions that allow collaborative exercises, and to establish design requirements and thus key design considerations for integrated systems that more seamlessly combine different modes of communication. Methods: We conducted a series of four user-centered design studies. This included four design workshops and seven prototype testing sessions with 18 people who had received CBT for depression in the past, and 11 qualitative interviews and three role-play sessions with 12 CBT therapists experienced in the treatment of depression. Studies took place between July and December 2017 in Bristol, United Kingdom. Results: Workshops and prototyping sessions with people who had received CBT identified three important requirements for integrated platforms delivering CBT therapy for depression as follows: (1) features that help to overcome depression-related barriers, (2) features that support engagement, and (3) features that reinforce learning and support the development of new skills. Research with therapists highlighted the importance of the therapist and client working together, the impact of technology on therapists’ workflow and workload, challenges and opportunities related to the use of online resources, and the potential of technology to support patient engagement. We use these findings to inform 12 design considerations for developing integrated therapy systems. Conclusions: To meet clients’ and therapists’ needs, integrated systems need to help retain the personal connection, support both therapist- and patient-led activities, and provide access to materials and the ability to monitor progress. However, developers of such systems should be mindful of their capacity to disrupt current work practices and increase therapists’ workload. Future research should evaluate the impact of integrated systems on patients and therapists in a real-world context