Social and Solidarity Economy. The Case of an Urban Consumption Co-operative in Greece

The apparent ubiquity of alternative – to the dominant economic model – economies, after the 2008 multidimensional crisis across the world, fuelled claims about a new style of mobilisation emerg-ing in Greece. It is the outcome of the evolution of the Greek anti-austerity movement and community-based experiences, consolidated to form new affiliations of collective initiatives and practices. Analysing original qualitative data derived from a case study of a Greek Urban Consumer Co-operative, this article engages with the debate of Social and Solidarity Economy. The research highlights the capacity of a Greek Urban Consumer Co-operative through sustainable consumption patterns to utilise local-traditional re-sources in order to empower local communities in times of crisis. Theoretically, this urban consumer co-operative generates new insights into the nature and meanings of a more sustainable and just economy, by changing the way it buys and sells food and other goods. From a policy and practice perspective, the paper raises the need for regional development strategies that capture the 'alternativeness' of these iso-lated initiatives, whose practices promote ethical, as well as environmental criteria and considerations in times of global economic crisis

On proton synchrotron blazar models: the case of quasar 3C 279

In the present work we propose an innovative estimation method for the minimum Doppler factor and energy content of the gamma-ray emitting region of quasar 3C 279, using a standard proton synchrotron blazar model and the principles of automatic photon quenching. The latter becomes relevant for high enough magnetic fields and results in spontaneous annihilation of gamma-rays. The absorbed energy is then redistributed into electron-positron pairs and soft radiation. We show that as quenching sets an upper value for the source rest-frame gamma-ray luminosity, one has, by neccessity, to resort to Doppler factors that lie above a certain value in order to explain the TeV observations. The existence of this lower limit for the Doppler factor has also implications on the energetics of the emitting region. In this aspect, the proposed method can be regarded as an extension of the widely used one for estimating the equipartition magnetic field using radio observations. In our case, the leptonic synchrotron component is replaced by the proton synchrotron emission and the radio by the VHE gamma-ray observations. We show specifically that one can model the TeV observations by using parameter values that minimize both the energy density and the jet power at the cost of high-values of the Doppler factor. On the other hand, the modelling can also be done by using the minimum possible Doppler factor; this, however, leads to a particle dominated region and high jet power for a wide range of magnetic field values. Despite the fact that we have focused on the case of 3C 279, our analysis can be of relevance to all TeV blazars favoring hadronic modelling that have, moreover, simultaneous X-ray observations.Comment: 12 pages, 11 figures, 1 Table, accepted for publication in MNRA

Afterglow emission in the context of an ‘one-zone’ radiation-acceleration model

In the present work we focus on the interplay between stochastic acceleration of charged particles and radiation processes in a region of turbulent magnetized plasma, setting the framework for an ‘one-zone’ radiation-acceleration model for Gamma-Ray Burst (GRB) afterglows. Specifically, we assume that the particle distribution is isotropic in space and treat in detail the particle propagation in the momentum-space. The electron distibution is modified by the acceleration, synchrotron and Synchrotron Self-Compton (SSC) radiation and escape processes. The magnetic field as well as the particle injection rate are functions of time as measured in the comoving frame of the blast wave. In order to study the dynamical evolution of this system, we numerically solve the time-dependent Fokker-Planck equation for the electron distribution and present the obtained particle and photon spectra of an indicative example

Implications of automatic photon quenching on compact gamma-ray sources

Aims: We investigate photon quenching in compact non-thermal sources. This involves photon-photon annihilation and lepton synchrotron radiation in a network that can become non-linear. As a result the gamma-ray luminosity of a source cannot exceed a critical limit that depends only on the radius of the source and on the magnetic field. Methods: We perform analytic and numerical calculations that verify previous results and extend them so that the basic properties of photon quenching are investigated. Results: We apply the above to the 2006 TeV observations of quasar 3C279 and obtain the parameter space of allowed values for the radius of the emitting source, its magnetic field strength and the Doppler factor of the flow. We argue that the TeV observations favour either a modest Doppler factor and a low magnetic field or a high Doppler factor and a high magnetic field.Comment: 10 pages, 12 figures, accepted for publication in Astronomy and Astrophysic

Ökologische Marginalisierung und Reaktion der einheimishen im ländlichen Griechenland

The conditions under which people live in rural areas, the ways in which resources are utilized and the prospects for conservation in the future are all in part influenced by the fundamental characteristics of national governments, European Union policies for economic and sectoral development, as well as processes such as globalization. Using an ecological marginalization perspective, this paper illustrates the consequences of proliferating intensive agriculture ‘alliances’ among European Union policies, the Greek state, and Greek domestic producers. Since many natural resources – soil, water, biodiversity – are already entrenched in industrial agricultural production systems, the author extrapolates from the patterns of production that make use of these natural resources to bolster the argument that Greek state policies, the timing of the country’s accession to the European Community in 1981, and local land use practices will particularly affect the potential consequences of future agricultural development. Even though the impacts of intensive agriculture vary by region and some rural areas have benefited from this development, the analysis suggests that rural people, communities and citizens of peri-urban territories all bear the costs of the industrial agriculture production system both in terms of social, health and environmental impacts. A core reason, this paper argues, is that the ‘alliances’ of intensive industrial agriculture are reinforcing processes and structures that increase pressure on the ecological integrity of rural areas leading to environmental degradation and the marginalization-abandonment of agriculture. Finally, the paper traces the cases of Alternative Agro-Food Networks (AAFNs) in Greece that promote socio-economic sustainability and health to local producers and consumers as an alternative to the current intensive agro-industrial food system which supports ecological marginalization.Uvjeti pod kojima žive stanovnici ruralnih područja, načini na koje iskorištavaju prirodne resurse i izgledi koje imaju za održanje u budućnosti uvijek su barem dijelom odraz politika nacionalnih vlada, politika ekonomskog i sektorskog razvoja Europske unije, te različitih procesa poput globalizacijskih. U radu se kroz ideju ekološke marginalizacije žele prikazati posljedice jačanja sprege između politike Europske unije, grčke vlade i domaćih grčkih proizvođača kroz razvoj intenzivne poljoprivrede. S obzirom da su mnogi prirodni resursi – tlo, voda i bioraznolikost – već postali dio proizvodnih sustava industrijske poljoprivrede, u radu se ta proizvodnja analizira kako bi se pokazalo da politike grčke vlade, pristup Europskoj zajednici 1981. godine, te načini lokalnog iskorištavanja tla najviše doprinose mogućim posljedicama za budući poljoprivredni razvoj. Iako postoje varijacije u učincima intenzivne poljoprivrede s obzirom na regije, pa neke ruralne regije imaju koristi od njenog razvoja, analiza upućuje na zaključak da ruralno stanovništvo i ruralne zajednice te građani periurbanih područja nose najveći teret proizvodnog sustava industrijske poljoprivrede. Jedan od glavnih razloga pronalazimo u postojećim „spregama“ unutar intenzivne industrijske poljoprivrede koje doprinose jačanju pritiska na ekološki integritet ruralnih područja, što pak dovodi do uništavanja okoliša i marginalizacije ili napuštanja poljoprivrede. Na kraju, u radu se analiziraju slučajevi Alternativnih agro-prehrambenih mreža (engl. Alternative Agro-Food Networks - AAFN) u Grčkoj kako bi se ukazalo na načine na koje je moguće razvijati socio-ekonomsku održivost i zdravlje lokalnih proizvođača i potrošača kao alternativu postojećem sustavu intenzivne agro-industrijske poljoprivrede koja dovodi do ekološke marginalizacije.Die Lebensverhältnisse der Einwohner in ländlichen Gebieten, die Art und Weise, wie sie die Naturressourcen nutzen und die Chancen für eine zukünftige Erhaltung, die sie haben, sind immer, wenigstens teilweise, ein Spiegelbild der Politiken der nationalen Regierungen, der Politik der Wirtschafts‑ und Sektorentwicklung der Europäischen Union, sowie jenes verschiedener Prozesse, wie z.B. derjenigen der Globalisierung. Aus der Perspektive der ökologischen Marginalisierung werden in der vorliegenden Arbeit die Auswirkungen der Stärkung des Bündnisses der EU-Politik, der griechischen Regierung und der einheimischen griechischen Produzenten auf die Entwicklung der intensiven Landwirtschaft dargestellt. Da viele Naturressourcen – der Boden, das Wasser und die Biodiversität – schon zu einem Bestandteil der Produktionssysteme der industriellen Landwirtschaft geworden sind, wird in der Arbeit diese Produktion analysiert, damit gezeigt wird, dass die Politik der griechischen Regierung, der EU-Beitritt im Jahr 1981, sowie die Methoden der lokalen Bodennutzung die Entwicklung der Landwirtschaft am meisten beeinträchtigen. Obwohl die Auswirkungen der intensiven Landwirtschaft in verschiedenen Regionen variieren und einige ländliche Regionen von ihrer Entwicklung Nutzen haben, weist die Analyse auf den Schluss hin, dass ländliche Bevölkerung, Gemeinden und Bürger aus periurbanen Gebieten die größte Last des Produktionssystems der industriellen Landwirtschaft tragen. Einer der Hauptgründe dafür liegt in den bestehenden „Bündnissen“ innerhalb der intensiven industriellen Landwirtschaft, die dazu beitragen, dass der Druck auf die ökologische Integrität der ländlichen Gebiete stärker wird, was zur Umweltzerstörung und Marginalisierung und Aufgabe der Landwirtschaft führt. Zum Schluss werden in der Arbeit Fälle von Alternativen Agro-Nahrungsnetzen (Alternative Agro-Food Networks - AAFN) in Griechenland analysiert, damit darauf hingewiesen werden kann, wie man die sozio-ökonomische Nachhaltigkeit und die Gesundheit lokaler Produzenten und Verbraucher entwickeln kann als Alternative für das bestehende System der intensiven agro- industriellen Landwirtschaft , die zu einer ökologischen Marginalisierung führt

Temporal signatures of leptohadronic feedback mechanisms in compact sources

The hadronic model of Active Galactic Nuclei and other compact high energy astrophysical sources assumes that ultra-relativistic protons, electron-positron pairs and photons interact via various hadronic and electromagnetic processes inside a magnetized volume, producing the multiwavelength spectra observed from these sources. A less studied property of such systems is that they can exhibit a variety of temporal behaviours due to the operation of different feedback mechanisms. We investigate the effects of one possible feedback loop, where \gamma-rays produced by photopion processes are being quenched whenever their compactness increases above a critical level. This causes a spontaneous creation of soft photons in the system that result in further proton cooling and more production of \gamma-rays, thus making the loop operate. We perform an analytical study of a simplified set of equations describing the system, in order to investigate the connection of its temporal behaviour with key physical parameters. We also perform numerical integration of the full set of kinetic equations verifying not only our analytical results but also those of previous numerical studies. We find that once the system becomes `supercritical', it can exhibit either a periodic behaviour or a damped oscillatory one leading to a steady state. We briefly point out possible implications of such a supercriticality on the parameter values used in Active Galactic Nuclei spectral modelling, through an indicative fitting of the VHE emission of blazar 3C 279.Comment: 19 pages, 20 figures, accepted for publication in MNRA

Application of neural networks to synchro-Compton blazar emission models

Jets from supermassive black holes in the centers of active galaxies are the most powerful persistent sources of electromagnetic radiation in the Universe. To infer the physical conditions in the otherwise out-of-reach regions of extragalactic jets we usually rely on fitting of their spectral energy distribution (SED). The calculation of radiative models for the jet non-thermal emission usually relies on numerical solvers of coupled partial differential equations. In this work machine learning is used to tackle the problem of high computational complexity in order to significantly reduce the SED model evaluation time, which is needed for SED fitting with Bayesian inference methods. We compute SEDs based on the synchrotron self-Compton model for blazar emission using the radiation code ATHE${\nu}$A, and use them to train Neural Networks exploring whether these can replace the original computational expensive code. We find that a Neural Network with Gated Recurrent Unit neurons can effectively replace the ATHE${\nu}$A leptonic code for this application, while it can be efficiently coupled with MCMC and nested sampling algorithms for fitting purposes. We demonstrate this through an application to simulated data sets and with an application to observational data. We offer this tool in the community through a public repository. We present a proof-of-concept application of neural networks to blazar science. This is the first step in a list of future applications involving hadronic processes and even larger parameter spaces.Comment: 12 pages, submitted, comments are welcome, code will be soon available at https://github.com/tzavellas/blazar_m

The Perceived Problems of People With Subclinical Personality Disorders: A Mental Health Literacy Study

This study looked at lay theories of how people with personality disorders (PDs) are perceived to cope with their interpersonal relationships. In all, 213 participants read 14 vignettes derived from Oldham's and Morris's (2000) book describing DSM III personality disorders for a popular audience. Participants were invited to do six ratings, including how happy each person in each vignette appeared to be and how successful at establishing long-term relationships. Effect sizes for each question across the 14 vignettes were small to medium. The six ratings factored into a single social adjustment scale, and there were many differences across the PDs on this measure. Those with dependent PD were judged as most successful in their social relationships while those who were schizoid PD were judged as least successful. A similar analysis using the three higher order clusters showed significant differences: Cluster C disordered people were judged as better adjusted than Cluster A people. Limitations of the methodology and implications are discussed