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• Migration trajectories of irregular migrants evolve non-linearly. • Social network dynamics and critical events explain how migrant trajectories evolve. • A typology is proposed to understand the varying role of networks for migration. • Networks mediate how migrants deal with critical events. While social networks have been widely argued to shape migrants' trajectories, their presence and their roles are not self-evident, nor constant. Common conceptualisations of migrants' social networks refer to the linkages between people in origin and destination countries. This underlies a rather linear notion of migration trajectories as a straightforward move from one country to another, and does not pay attention to the networks migrants have elsewhere in the world and those formed en route. This paper investigates how various network members and changes in migrants' social networks are associated with the evolution of their migration trajectories. It is based on ethnographic fieldwork and longitudinal social network analysis among 40 sub-Saharan migrants, part of whose trajectories in Turkey and Greece were followed over time. The migration policy environment in both countries is rather volatile, which is manifested in migrants' daily lives through the experience of critical events. Findings show that social network dynamics explain how migrants act upon these events and shape their migration trajectory accordingly. The findings question common representations of non-linear migration trajectories as the mere consequence of onward moves interrupted by policy constraints. By demonstrating the importance of changes that take place in networks and the timing thereof, it ultimately contributes to a better understanding of how non-linear migration trajectories evolve over time. [ABSTRACT FROM AUTHOR]

Abstract The emergence of agriculture in Greece denotes the start of the Neolithic in Europe, however, little is known about dietary practices in the region. Archaeobotanical and zooarchaeological remains indicate reliance on cereals and pulses, together with meat-based subsistence practices, including sheep/goat and pig husbandry. Preliminary investigations of dietary practices obtained through lipid residue analysis of pottery of a small number of sites in the region have confirmed primarily carcass products were processed. The weak evidence for dairy products contrasts with finding of dairy-based subsistence strategies in NW Anatolia, which is surprising given its close proximity. This paper aims to build on this earlier work to provide a more detailed model for the dietary changes throughout the region, both chronologically and spatially. To achieve this >900 potsherds from 11 sites spanning the Early (EN) to Late Neolithic (LN) periods from the north of Greece have been investigated using the lipid biomarker approach involving high temperature-gas chromatography (HT-GC), GC-mass spectrometry (GC-MS) and GC-combustion-isotope ratio MS (GC-C-IRMS) to determine the nature and origins of organic residues preserved in the fabric of pottery vessels. Lipid residue analysis of pottery vessels revealed ruminant and non-ruminant carcass fats comprise the majority of animal fat types identified, reflecting the high abundance of sheep/goat and pig in faunal assemblages. The emergence of dairying in northern Greece can now be dated to the site of EN/Middle Neolithic (MN) Ritini (5900/5700 - 5500 cal. B.C.E.), however, the frequency of dairy fat residues was low, overall, indicating that dairying was not intensively practised. The δ13C values of the fatty acids extracted from potsherds reflect a predominately C 3 diet, however, in the EN and MN there is greater variation with some lipids exhibiting enriched δ13C values indicating a significant abundance of C 4 plants in the ecosystem(s) covered by the study. Significantly, plant-derived n- alkanes (C 22 to C 34) detected in pottery vessels provide the first evidence for plant processing identified in lipid residues from ceramic vessels in Neolithic northern Greece, supporting the abundant archaeobotanical evidence for the processing of cereals and pulses. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes an integrated GIS-based methodology for conservation value assessment using the traditional species-based and a habitat-based multi-criteria evaluation. The methodology was applied to 49 small islands and islets in the East Aegean area, belonging to a SCI Natura 2000 site. The species-based (botanical approach) conservation status assessment attributes a specific weight to the parameter of endemism, while the multi-criteria evaluation (MCE) approach emphasises the criteria of diversity, rarity, naturalness, replaceability and threat on each habitat type in combination with the number of significant taxa. The conservation values attained from the two approaches are significantly correlated, but the multi-criteria approach is more effective as it includes all the habitat types within the study area in the 25% of the polygons with the highest conservation values. Furthermore, results from the multi-criteria analysis were more in line with subjective assessments of the conservation value of the habitat types than the ones obtained by the botanical approach. [Copyright &y& Elsevier]

Abstract: Using satellite data for flood forecasting in catchments located in mid-latitudes is challenging to engineers and model developers, in no small part due to the plethora of data sets that need to be retrieved, combined, calibrated and used for simulation in real time. The differences between the various satellite rainfall data products and the continuous improvement in their quantity and quality render the development of a single software tool, able to read and process all the different data sets, particularly difficult. Even if such an endeavour was undertaken, the degree of flexibility and extensibility that such a tool would require to accommodate future versions of data sets, available in different file formats as well as different temporal and spatial resolution should not be underestimated. This paper describes the development of a flood forecasting system that addresses this issue through a modular architecture based on the use of the Open Modeling Interface (OpenMI) standard, which facilitates the interaction between a number of separate software components. It is suggested that this approach greatly simplifies programming and debugging and eliminates the need to create spatial and temporal transformation functions without significantly compromising the overall execution speed. The approach and system were tested for forecasting flood events within a particularly challenging transboundary catchment, the Evros catchment, extending between Greece, Bulgaria and Turkey. The system uses two sets of data sources, as an example (NASA’s TRMM 3B42 and 3B42RT satellite data sets) to forecast flooding in the Evros catchment. Results indicate that OpenMI greatly facilitates the complex interaction of various software components and considerably increases the flexibility and extensibility of the overall system and hence its operational value and sustainability. [Copyright &y& Elsevier]

Abstract: This paper describes a dynamic demand model, referred to as dynamic abstract mode model, for estimating both the short- and long-term responses of air passengers to changes in relative air-sea travel cost components in competitive markets. The implementation of the model in the competitive market of Aegean islands in Greece demonstrates the importance of considering the past volumes of air passengers and relative travel cost components to explain current air travel demand. [Copyright &y& Elsevier]

Abstract: Most medium and small islands of the Aegean Archipelagos face serious infrastructure problems, strongly related with the limited electrical energy available at extremely high cost. On the other hand, the area is characterized by very high wind speeds and abundant solar energy, thus the exploitation of the available renewable energy sources (RES) may significantly contribute to the fulfillment of the local societies energy demand at minimum environmental and macroeconomic cost. However, the stochastic availability of wind energy and the variable availability of solar energy, the daily and seasonal electricity demand fluctuations, as well as the limited local electrical network capacity result in serious restrictions concerning the maximum renewable power penetration. In this context, the present paper investigates the possibility of creating a combined electricity generation facility based on the exploitation of wind or/and solar potential of an area as well as on the utilization of an appropriate energy storage configuration in order to replace the existing thermal power stations with rational investment requirements. For this purpose, the major parameters of the proposed integrated configuration are firstly calculated and its financial viability is accordingly analyzed. One of the main targets of the proposed solution is to maximize the RES exploitation of the area at a minimum electricity generation cost, while special emphasis is given in order to select the most cost-efficient energy storage device available. According to the results obtained the proposed solution is not only financially attractive but also improves the quality of the electricity offered to the local communities, substituting the expensive and heavily polluting existing thermal power stations. [Copyright &y& Elsevier]

The move towards deregulated transport markets is generally expected to increase competition thus producing benefits for the passengers. This paper examines the effect of competition between of air and sea transport following deregulation within the Greek Aegean region. Comparison of market surveys conducted over three periods identifies how passengers respond to this process. Findings suggest that competition between modes is increasing, although the final form of the market remains to be seen. [Copyright &y& Elsevier]

Abstract: Aegean Islands in Greece, mainly the Dodecanese and Cyclades, face a serious problem of water scarcity. The situation has deteriorated over the last years due to the continuous and fast growing tourist development. Moreover, salty water intrusion into the aquifers is seriously threatening the quality of the existing water reserves. In many arid islands water is transported by sea, at a considerably high cost (reaches about 5–8 €/m3 in some cases) with a tendency to further increase due to rises in the cost of fuels, inflation, etc. Desalination is foreseen as a solution to this problem as it is a process which can provide fresh and potable water in the required quantities, at a much lower cost. This paper presents the current status in Cyclades and Dodecanese, existing water demand and transported quantities of water, and the desalination units that exist in the Aegean Islands. Furthermore, we estimate costs and the associated efforts that are required for the installation of small desalination plants producing useful amounts of fresh water for local needs. [Copyright &y& Elsevier]