42 research outputs found
'Diverse mobilities': second-generation Greek-Germans engage with the homeland as children and as adults
This paper is about the children of Greek labour migrants in Germany. We focus on two life-stages of âreturnâ for this second generation: as young children brought to Greece on holidays or sent back for longer periods, and as young adults exercising an independent âreturnâ migration. We draw both on literature and on our own field interviews with 50 first- and second-generation Greek-Germans. We find the practise of sending young children back to Greece to have been surprisingly widespread yet little documented. Adult relocation to the parental homeland takes place for five reasons: (i) a âsearch for selfâ; (ii) attraction of the Greek way of life; (iii) the actualisation of the âfamily narrative of returnâ by the second, rather than the first, generation; (iv) life-stage events such as going to university or marrying a Greek; (v) escape from a traumatic event or oppressive family situation. Yet the return often brings difficulties, disillusionment, identity reappraisal, and a re-evaluation of the German context
Simultaneous assessment of acidogenesis-mitigation and specific bacterial growth-inhibition by dentifrices
Dentifrices can augment oral hygiene by inactivating bacteria and at sub-lethal concentrations may affect bacterial metabolism, potentially inhibiting acidogenesis, the main cause of caries. Reported herein is the development of a rapid method to simultaneously measure group-specific bactericidal and acidogenesis-mitigation effects of dentifrices on oral bacteria. Saliva was incubated aerobically and anaerobically in Tryptone Soya Broth, Wilkins-Chalgren Broth with mucin, or artificial saliva and was exposed to dentifrices containing triclosan/copolymer (TD); sodium fluoride (FD); stannous fluoride and zinc lactate (SFD1); or stannous fluoride, zinc lactate and stannous chloride (SFD2). Minimum inhibitory concentrations (MIC) were determined turbidometrically whilst group-specific minimum bactericidal concentrations (MBC) were assessed using growth media and conditions selective for total aerobes, total anaerobes, streptococci and Gram-negative anaerobes. Minimum acid neutralization concentration (MNC) was defined as the lowest concentration of dentifrice at which acidification was inhibited. Differences between MIC and MNC were calculated and normalized with respect to MIC to derive the combined inhibitory and neutralizing capacity (CINC), a cumulative measure of acidogenesis-mitigation and growth inhibition. The overall rank order for growth inhibition potency (MIC) under aerobic and anaerobic conditions was: TD> SFD2> SFD1> FD. Acidogenesis-mitigation (MNC) was ordered; TD> FD> SFD2> SFD1. CINC was ordered TD> FD> SFD2> SFD1 aerobically and TD> FD> SFD1> SFD2 anaerobically. With respect to group-specific bactericidal activity, TD generally exhibited the greatest potency, particularly against total aerobes, total anaerobes and streptococci. This approach enables the rapid simultaneous evaluation of acidity mitigation, growth inhibition and specific antimicrobial activity by dentifrices
Polymer-stable magnesium nanocomposites prepared by laser ablation for efficient hydrogen storage
Hydrogen is a promising alternative energy carrier that can potentially
facilitate the transition from fossil fuels to sources of clean energy because
of its prominent advantages such as high energy density (142 MJ per kg), great
variety of potential sources (for example water, biomass, organic matter), and
low environmental impact (water is the sole combustion product). However, due
to its light weight, the efficient storage of hydrogen is still an issue
investigated intensely. Various solid media have been considered in that
respect among which magnesium hydride stands out as a candidate offering
distinct advantages. Recent theoretical work indicates that MgH2 becomes less
thermodynamically stable as particle diameter decreases below 2 nm. Our DFT
(density functional theory) modeling studies have shown that the smallest
enthalpy change, corresponding to 2 unit-cell thickness (1.6 {\AA} Mg/3.0{\AA}
MgH2) of the film, is 57.7 kJ/molMg. This enthalpy change is over 10 kJ per
molMg smaller than that of the bulk. It is important to note that the range of
enthalpy change for systems that are suitable for mobile storage applications
is 15 to 24 kJ permolH at 298 K. The important key for the development of
air/stable Mg/nanocrystals is the use of PMMA (polymethylmethacrylate) as an
encapsulation agent. In our work we use laser ablation, a non-electrochemical
method, for producing well dispersed nanoparticles without the presence of any
long range aggregation. The observed improved hydrogenation characteristics of
the polymer/stable Mg-nanoparticles are associated to the preparation procedure
and in any case the polymer laser ablation is a new approach for the production
of air/protected and inexpensive Mg/nanoparticles.Comment: Hydrogen Storage, Mg - Nanoparticles, Polymer Matrix Composites,
Laser Ablation, to appear in International Journal of Hydrogen Energy, 201
Social Control in Transnational Families: Somali Women and Dignity in Johannesburg
Transnational mobility often separates families and distances individuals from the kinship and social structures by which they organized their lives prior to migration. Myriad forms of insecurity have been the impetus for Somali movement into the diaspora, with people fleeing the realities of conflict that have marked Somalia for decades while physically dividing families as individuals settle in different countries around the world. Mobility has altered the dynamics of households, families, and communities post-migration, reshaping social constructions as individuals move on without the familial support that sustained them in Somalia. While outcomes of these hardships are variable and often uneven in different settlement spaces, migration can offer new opportunities for people to pursue avenues from which they were previously excluded, such as by assuming roles and responsibilities their relatives once filled. These changes precipitate shifting identities and are challenging for women who find themselves self-reliant in the diaspora, particularly in the absence of (supportive) husbands and close kin.Drawing on ethnographic research in Johannesburgâs Somali community, this chapter explores the assumption that migration provides an opening for women to challenge subordinating gender norms. Settlement often grants women greater freedom to make choices in their lives, such as in employment and personal relationships, and yet they remain constrained by networks that limit their autonomy. Even with transnational migration and protracted separation, women are family representatives who must uphold cultural notions of respectability despite realities that position them as guardians and family providers. Women remain under the watchful eye of their extended families through expansive networks and the ease of modern communication, which facilitate a new form of social control as womenâs behavior is carefully monitored and reported to relatives afar. These actualities raise questions about the degree to which transnational movement is a liberating force for women or rather a reconfiguration of social control. I argue that despite womenâs changing position in their households and families, they remain limited by social control within their extended families and communities
Monitoring the carbon footprint of dry bulk shipping in the EU: An early assessment of the MRV regulation
Aiming at reducing CO2 emissions from shipping at the EU level, a system for monitoring, reporting, and verification (MRV) of CO2 emissions of ships was introduced in 2015 with the so-called 'MRV Regulation'. Its stated objective was to produce accurate information on the CO2 emissions of large ships using EU ports and to incentivize energy efficiency improvements by making this information publicly available. On 1 July 2019, the European Commission published the relevant data for 10,880 ships that called at EU ports within 2018. This milestone marked the completion of the first annual cycle of the regulation's implementation, enabling an early assessment of its effectiveness. To investigate the value of the published data, information was collected on all voyages performed within 2018 by a fleet of 1041 dry bulk carriers operated by a leading Danish shipping company. The MRV indicators were then recalculated on a global basis. The results indicate that the geographic coverage restrictions of the MRV Regulation introduce a significant bias, thus prohibiting their intended use. Nevertheless, the MRV Regulation has played a role in prompting the IMO to adopt its Data Collection System that monitors ship carbon emissions albeit on a global basis. © 2019 by the authors
Methodological aspects of a GIS-based environmental health inspection program used in the Athens 2004 Olympic and Para Olympic Games
Background: The use of geographical information system (GIS)
technologies in public health surveillance is gradually gaining momentum
around the world and many applications have already been reported in the
literature. In this study, GIS technology was used to help county
departments of Public Health to implement environmental health
surveillance for the Athens 2004 Olympic and Para Olympic Games.
Methods: In order to assess the workload in each Olympic county, 19
registry forms and 17 standardized inspection forms were developed to
register and inspect environmental health items requiring inspection
(Hotels, restaurants, swimming pools, water supply system etc),
respectively. Furthermore, related databases were created using Epi Info
2002 and a geographical information system (GIS) were used to implement
an integrated Environmental Health inspection program. The project was
conducted in Athens by the Olympic Planning Unit (OPU) of the National
School of Public Health, in close cooperation with the Ministry of
Health and Social Solidarity and the corresponding departments of Public
Health in all municipalities that were scheduled to host events during
the Athens 2004 Olympic and Para Olympic games.
Results: A total of 44,741 premises of environmental health interest
were geocoded into GIS databases and several electronic maps were
developed. Using such maps in association with specific criteria, we
first identified the maximum workload required to execute environmental
health inspections in all premises within the eleven Olympic County
Departments of Public Health. Six different scenarios were created for
each county, based on devised algorithms in order to design the most
effective and realistic inspection program using the available
inspectors from each municipality. Furthermore, GIS applications were
used to organize the daily inspection program for the Olympic games,
provide coloured displays of the inspection results and link those
results with the public health surveillance of specific cases or
outbreak investigation.
Conclusion: Our computerised program exhibited significant efficiency in
facilitating the prudent use of public health resources in implementing
environmental health inspections in densely populated urban areas as
well as in rural counties. Furthermore, the application of simple
algorithms in integrating human and other resources provided tailored
and cost-effective applications to different public health agencies