Synchrotron Emissions in GRB Prompt Phase Using a Semi Leptonic and Hadronic Model

In this communication devoted to the prompt emission of GRBs, we claim that some important parameters associated to the magnetic field, such as its index profile, the index of its turbulence spectrum and its level of irregularities, will be measurable with GLAST. In particular the law relating the peak energy Epeak with the total energy E (like Amati's law) constrains the turbulence spectrum index and, among all existing theories of MHD turbulence, is compatible with the Kolmogorov scaling only. Thus, these data will allow a much better determination of the performances of GRBs as particle accelerators. This opens the possibility to characterize both electron and proton acceleration more seriously. We discuss the possible generation of UHECRs and of its signature through GeV-TeV synchrotron emission.Comment: 30th International Cosmic Ray Conference (ICRC2007) - Proceeding #107

Observational Constraints on the Angular and Spectral Distributions of Photons in Gamma-Ray Burst Sources

The typical spectra of gamma-ray bursts (GRBs) are discussed in the context of the compactness problem for GRB sources and how it is resolved in the popular fireball model. In particular, observational (model-independent) constraints on the collimation of the gamma-rays and the dependence of the collimation angle on the photon energy are considered. The fact that the threshold for the creation of $e^{-}e^{+}$ pairs depends on the angle between the momenta of the annihilating photons in the GRB source provides an alternative solution to the compactness problem. A new approach to explaining GRBs, taking into account the angular dependence for pair creation, is proposed, and the main features of a scenario describing a GRB source with a total (photon) energy smaller or of the order of $10^{49}$ erg are laid out. Thus, we are dealing with an alternative to an ultra-relativistic fireball, if it turns out (as follows from observations) that all "long" GRBs are associated with normal (not peculiar) core-collapse supernovae. The effects of radiation pressure and the formation of jets as a consequence of even a small amount of anisotropy in the total radiation field in a (compact) GRB source are examined in this alternative model. Possible energy release mechanisms acting in regions smaller or of the order of $10^{8}$ cm in size (a compact model for a GRB) are discussed. New observational evidence for such compact energy release in the burst source is considered.Comment: 15 pages, no figures, no table

The effects of market economy and foreign MNE subsidiaries on the convergence and divergence of HRM

This study explores patterns of human resource management (HRM) practices across market economies, and between indigenous firms and foreign MNE subsidiary operations, offering a novel perspective on convergence and divergence. Applying institutional theorizing to improve our understanding of convergence/ divergence as a process and an outcome, data collected from nine countries at three points in time over a decade confirm that convergence and divergence occur to different extents in a non-linear fashion, and vary depending on the area of HRM practice observed. Patterns of adoption and convergence/ divergence are explained through the effect of institutional constraints, which vary between liberal and coordinated market economies, and between indigenous firms and foreign MNE subsidiaries. The study contributes a more graded conceptualization of convergence/ divergence, which reflects the complex dynamic reality of international business

Integration a few kilometres away from the motherland: Albanians' internal migration, settlement and voluntary return in Epirus and the Ionian Islands in Greece

This paper focuses on the interconnection between internal migration in Greece, integration and voluntary return prospects of Albanians currently living in Epirus and the Ionian Islands. It is based on field research conducted during 2008 among immigrants who live in Ioannina, Preveza, Arta and Kerkyra. The study highlights the different types of internal trajectories that migrants had follow before settling in the neighbouring areas of Greece, just a few kilometres away from their homeland. Migrant's current economic integration and some of the socio-economic barriers they face are discussed and linked to their will to return permanently to Albania. Internal mobility is found to be a preceding step in search for integration; integration, in turn, acts as a counterbalance to both further internal movement and voluntary return prospects, at least for the next foreseeable years. © migration letters

Trans-border mobility and integration in border regions: Albanian migrants in Epirus and the Ionian Islands in Greece

The emergence of a new economic and political system in post-socialist Albania strongly affected the neighbouring regions of Greece, particularly by successive waves of migration. This paper explores three key aspects of Albanian migration to Greece. First, it investigates the basic factors that determine Albanian migrants' decision to settle in middle-sized Greek cities close to the border with Albania. Second, it examines the main patterns of trans-border mobility between Albania and Greece. And third, it looks at the possible interconnections between integration into Greek society and trans-border mobility. The role of geographical proximity and other factors that define migrants' integration are also discussed. The paper concludes that frequent mobility produces important trans-national activity and discusses whether this mobility corresponds to an emerging type of 'trans-migrant'

Theoretical Perspectives and Empirical Facts on Water Sector Privatization: The Greek Case Against European and Global Trends

The scope of this paper is to investigate the Greek 'path' to water privatization and its possible interconnections with the ongoing restructuring of the water sector on an EU and a global level. The paper starts with a contemporary, spatially-sensitive analysis of the expanding role of water multinationals, by focusing on water supply operators of the southern EU. Afterwards, it highlights the peculiarities of the 'Greek path' to private sector participation by studying the two most important Greek water companies, in the cities of Athens and Thessaloniki respectively. As found, these companies have partially, though successfully, been transformed according to the rules of the 'market-environmentalist' paradigm. The state drives the privatization effort, while at the same time, insufficiently regulates the activity of both companies. Based on the Greek case, the paper discusses whether the analytical tools offered by a critical approach, the 'accumulation-by-dispossession' thesis, can better interpret changes in water companies of the 'advanced-South'

Analysis and evaluation of the operational status of municipal wastewater treatment plants in the Dodecanese prefecture in Greece

Data from municipal and private wastewater treatment plants (WWTP) in the Dodecanese prefecture in Greece was collected via a questionnaire and personal interviews, and was analyzed with respect to the operational status of the plants. The data was compared with the latest reports by the Greek Ministry of the Environment, which is what is officially reported at a national level and to the European Union (EU), and what judges Greece's compliance with EU Directives. Our assessment is that the picture presented by the Ministry is limited and optimistic when compared to reality, with many plants going unreported. This confirms what other researchers have reported previously, and presents an update on operational status, specifically for the highly touristic and ecologically sensitive island area of the Dodecanese. A short survey of the private WWTPs belonging to hotel establishments reveals that, although they are expected to treat a large percentage of the wastewaters produced in the islands during summer months, most of them operate poorly, while no regular checks are performed by public health officials