Mobilitetskulturer i Europa: En undersøgelse baseret på clusteranalyse af 28 europæiske lande

Europæiske tilgange til fremme af grøn mobilitet og grønne rejsemønstre kræver bedre viden om de forskellige mobilitetskulturer på tværs af lande og regioner i EU. For at analysere forskellene inden for Europa grupperede vi en Eurobarometer stikprøve af EU’s befolkning i otte segmenter baseret på deres mobilitetsmønstre, holdninger til transportmidler og miljøbevidsthed. Disse grupper – herunder for eksempel "grønne cyklister" og "komfortbilister" – adskiller sig ikke kun ved deres transportmiddelvalg, men også ved deres socioøkonomiske baggrund, IT-orientering og tilfredshed med livet. EU’s 28 medlemslande blev efterfølgende inddelt i seks landegrupper baseret på mobilitetsgruppernes andel af befolkningen. Landegrupperne peger mod at der er væsentligt forskellige mobilitetskulturer inden for EU, der kræver tilsvarende forskellige politiske strategier og tilgange til bl.a. bæredygtig transport og adfærdsændringer

Epithelzellinvasion durch Shigella flexneri

Shigellen sind Erreger der bakteriellen Dysenterie beim Menschen. Ein notwendiger Schritt bei der Pathogenese der Shigellose ist die Invasion von Darmepithelzellen durch das Bakterium. Der Mikroorganismus löst dabei in der Wirtszelle Veränderungen des Aktinzytoskeletts aus, die zur Bildung einer blütenähnlichen Membranstruktur und schließlich zur Internalisierung des Pathogens führen. Diese Umbauvorgänge am Zytoskelett sind abhängig von einem Wirtszellprotein, der kleinen GTPase Rho. Drei Isoformen von Rho (A, B und C) sind beschrieben, deren Aminosäuresequenzen zu etwa 90% identisch sind. Während der Zellinvasion durch Shigella akkumulieren verschiedene Rho-Isoformen an unterschiedlichen Lokalisationen des Invasionskomplexes. Dabei werden RhoA vorwiegend um die eindringenden Bakterienherum, RhoB und RhoC hingegen hauptsächlich in die bakterieninduzierten zellulären Protrusionen rekrutiert. Durch Untersuchung von Rho-Hybridkonstrukten konnte gezeigt werden, daß ein prä-C-terminales, acht Aminosäuren umfassendes Modul die Rekrutierungsmuster von RhoA bzw. RhoC bestimmt. Der Austausch zweier Aminosäuren innerhalb des Moduls führte zu einer Konversion des Rekrutierungsmusters von RhoA. Wir konnten zeigen, daß die Rekrutierung von RhoA vom Funktionszustand der GTPase (Bindung von GTP/GDP) sowie von der Phosphorylierung durch die Proteinkinase A unabhängig ist. Schließlich wurde hier nachgewiesen, daß auch RhoD, das zu RhoA, B und C auf der Primärstrukturebene nur zu etwa 50% homolog ist, an die Bakterieneintrittsstelle rekrutiert werden kann. RhoD folgt dabei dem Rekrutierungsmuster von RhoB und RhoC.Shigella causes bacillary dysentery in humans. Bacterial invasion of enterocytes is an essential step in the pathogenesis of shigellosis. Pathogen-triggered rearrangements of the host cell actin cytoskeleton induce a blossom-like membrane structure for internalisation of the microorganism. Actin remodeling requires activity of the host cell small GTPase rho. Three highly homologous rho isoforms (A, B and C) have been described with amino acid identities of about 90%. During Shigella invasion these rho isoforms accumulate at different sites of the invasion complex. While rhoA is chiefly recruited around entering bacteria, rhoB and rhoC are essentially translocated to the bacteria-induced cellular protrusions. Using a variety of rho hybrid constructs in a HeLa cell transfection-infection assay we were able to show that a pre-C-terminal stretch of eight amino acids determines the recruitment patterns of rhoA and rhoC. Exchange of two amino acids was sufficient for conversion of the rhoA recruitment pattern into a rhoC-like pattern. We could demonstrate that rhoA recruitment is independent of its functional state (GDP- or GTP-bound) or phosphorylation by the proteinkinase A (PKA). Finally, we have shown that rhoD, another member of the rho family which shares only 50% of its primary structure with rhoA, B or C, is also recruited to the bacterial entry site exhibiting a rhoB/C-like pattern of distribution

Growing population segments and their impact on future transport

The European population is facing enormous demographic changes. Based on data from the Danish National Travel Survey (NTS), this paper focuses on three major societal trends – changing family structures, ageing, and urbanisation – and the impact of these trends on future car use in Denmark. We compared the mode choice of single parents and people in single person households (both in “family age” and after retirement) with the choice of people in more traditional household forms. Additionally, we looked into differences within these groups related to gender and urban from. The relevance of these variables for car use as driver, as passenger, and in total was estimated in linear regression analyses. Persons living alone showed the lowest car use; living with a partner and having kids increased driving. While gender differences in older people’s car use could partly be explained with women’s lower car availability and driving licence rates, this was not the case for younger people. Thus, gender roles and different travel preferences are expected to play a role here. Living in a large urban area significantly decreased car use of younger people, whereas it increased older people’s car use as passenger. The lower driving rates of singles and single parents compared to couples with children could be explained with differences in car availability. When this was controlled for, single parents used the car as often as couples with children. To what extent the mobility needs of single parents are met satisfactorily without a car and whether they could serve as a model for car-free living are among the questions that cannot be answered based on the NTS data but should be addressed in future research

Free-floating carsharing in Copenhagen: A study on user experience in a cycling city

Free-floating carsharing is emerging in cities around the world. Based on a survey of car2go (n=95) and DriveNow users (n=737) in Copenhagen, followed by in-depth interviews with selected car2go users (n=12), this paper focuses on the practices and motives related to the use of a freefloating carsharing service in a city with a distinct cycling culture. Data were collected within the first year of the car2go and DriveNow launch. Like in other studies, users were mainly young, highly educated males, living in the city centre. However, different from other studies, they were predominantly daily cyclists. A key finding was that car2go did not substitute or compete with primary transport modes, especially sincecar2go (as well as DriveNow) was only used to a small degree for commuting. Based on in-depth interviews, different motives and user patterns could be identified depending on car ownership status. Non-car owners primarily used car2go for leisure or business trips and for transporting goods, whereas car owners mostly used car2go to avoid driving their private car in the city. For both groups, car2go could not fully cover their car needs. The withdrawal of car2go from Copenhagen after 17 months of operation is reflected based on the identified mobility patterns and user experiences.Free-floating carsharing is emerging in cities around the world. Based on a survey of car2go (n=95) and DriveNow users (n=737) in Copenhagen, followed by in-depth interviews with selected car2go users (n=12), this paper focuses on the practices and motives related to the use of a free-floating car sharing service in a city with a distinct cycling culture. Data were collected within the first year of the car2go and DriveNow launch. Like in other studies, users were mainly young, highly educated males, living in the city centre. However, different from other studies, they were predominantly daily cyclists. A key finding was that car2go did not substitute or compete with primary transport modes, especially since car2go (as well as DriveNow) was only used to a small degree for commuting. Based on in-depth interviews, different motives and user patterns could be identified depending on car ownership status. Non-car owners primarily used car2go for leisure or business trips and for transporting goods, whereas car owners mostly used car2go to avoid driving their private car in the city. For both groups, car2go could not fully cover their car needs. The withdrawal of car2go from Copenhagen after 17 months of operation is reflected based on the identified mobility patterns and user experiences