A Digital Dud? New Media, Participation, and Voting in the 2004 and 2008 United States Presidential Elections

This dissertation analyzes the linkages between new media and the possible emergence of the youngest members of the voting population (the “digital native” generation, who have grown up concurrently with the rise of the internet as a means of communication). The main question is whether this digital native generation will have more civic and political participation due to their use of online news sources and social media communication on news media websites and elsewhere on the internet. Regression analyses are used to explain civic and political participation, using American National Election Studies (ANES) from the 2004 and 2008 presidential elections. The analysis is done in three components. In the first paper, looking at the 2008 election, the impact of the “new media” was important for all generations, but the oldest generations—rather than the digital natives—had the highest levels of civic and political participation. In other words, the digital native generation did not, in fact, have more civic or political participation. In the second paper on the 2008 ANES data set, the impact of urban and rural differences were also tested to determine whether a presumed lack of access to new media would impact civic and political participation. This also proved not to be the case. Connected to this, an examination of various regions of the country did not have a significant impact upon levels of participation. In the third paper on both the 2004 and 2008 ANES, the explanation of civic and political participation diverges. Although online news consumption may be important for civic participation, members of older generations still participate more. For political participation, the youngest generation in 2004 had a positive effect on participation, which was the opposite result of the study on the 2008 ANES. Education was more important in 2008 than in 2004. Generally, the overall investigation finds that while new technology does have a sizeable impact upon political and civic participation, the digital natives’ more frequent use of these new media is not large enough to counteract the more traditional explanations of civic and political participation. Older generations of voters have higher incomes, more education, and more free time. These factors lead to higher levels of political and civic participation, compared to members of the youngest generation. As such, the “digital revolution” has been something of a “digital dud”, with significantly less impact than has been previously suggested by journalists in the media and indeed by some academics. Nonetheless, the impact of the new media affects all of the generations studied, and is thus still noteworthy and significant

Pseudomonas aeruginosa PAO1 Preferentially Grows as Aggregates in Liquid Batch Cultures and Disperses upon Starvation

In both natural and artificial environments, bacteria predominantly grow in biofilms, and bacteria often disperse from biofilms as freely suspended single-cells. In the present study, the formation and dispersal of planktonic cellular aggregates, or ‘suspended biofilms’, by Pseudomonas aeruginosa in liquid batch cultures were closely examined, and compared to biofilm formation on a matrix of polyester (PE) fibers as solid surface in batch cultures. Plankton samples were analyzed by laser-diffraction particle-size scanning (LDA) and microscopy of aggregates. Interestingly, LDA indicated that up to 90% of the total planktonic biomass consisted of cellular aggregates in the size range of 10–400 µm in diameter during the growth phase, as opposed to individual cells. In cultures with PE surfaces, P. aeruginosa preferred to grow in biofilms, as opposed to planktonicly. However, upon carbon, nitrogen or oxygen limitation, the planktonic aggregates and PE-attached biofilms dispersed into single cells, resulting in an increase in optical density (OD) independent of cellular growth. During growth, planktonic aggregates and PE-attached biofilms contained densely packed viable cells and extracellular DNA (eDNA), and starvation resulted in a loss of viable cells, and an increase in dead cells and eDNA. Furthermore, a release of metabolites and infective bacteriophage into the culture supernatant, and a marked decrease in intracellular concentration of the second messenger cyclic di-GMP, was observed in dispersing cultures. Thus, what traditionally has been described as planktonic, individual cell cultures of P. aeruginosa, are in fact suspended biofilms, and such aggregates have behaviors and responses (e.g. dispersal) similar to surface associated biofilms. In addition, we suggest that this planktonic biofilm model system can provide the basis for a detailed analysis of the synchronized biofilm life cycle of P. aeruginosa

Structural Basis for Functional Tetramerization of Lentiviral Integrase

Experimental evidence suggests that a tetramer of integrase (IN) is the protagonist of the concerted strand transfer reaction, whereby both ends of retroviral DNA are inserted into a host cell chromosome. Herein we present two crystal structures containing the N-terminal and the catalytic core domains of maedi-visna virus IN in complex with the IN binding domain of the common lentiviral integration co-factor LEDGF. The structures reveal that the dimer-of-dimers architecture of the IN tetramer is stabilized by swapping N-terminal domains between the inner pair of monomers poised to execute catalytic function. Comparison of four independent IN tetramers in our crystal structures elucidate the basis for the closure of the highly flexible dimer-dimer interface, allowing us to model how a pair of active sites become situated for concerted integration. Using a range of complementary approaches, we demonstrate that the dimer-dimer interface is essential for HIV-1 IN tetramerization, concerted integration in vitro, and virus infectivity. Our structures moreover highlight adaptable changes at the interfaces of individual IN dimers that allow divergent lentiviruses to utilize a highly-conserved, common integration co-factor

The climate response to emissions reductions due to COVID‐19: initial results from CovidMIP

Many nations responded to the corona virus disease‐2019 (COVID‐19) pandemic by restricting travel and other activities during 2020, resulting in temporarily reduced emissions of CO2, other greenhouse gases and ozone and aerosol precursors. We present the initial results from a coordinated Intercomparison, CovidMIP, of Earth system model simulations which assess the impact on climate of these emissions reductions. 12 models performed multiple initial‐condition ensembles to produce over 300 simulations spanning both initial condition and model structural uncertainty. We find model consensus on reduced aerosol amounts (particularly over southern and eastern Asia) and associated increases in surface shortwave radiation levels. However, any impact on near‐surface temperature or rainfall during 2020–2024 is extremely small and is not detectable in this initial analysis. Regional analyses on a finer scale, and closer attention to extremes (especially linked to changes in atmospheric composition and air quality) are required to test the impact of COVID‐19‐related emission reductions on near‐term climate.C. D. Jones, P. Nabat, R. Séférian acknowledge support from the European Union's Horizon 2020 research and innovation program under grant agreement No 641816 (CRESCENDO). R. D. Lamboll, P. M. Forster, J. Rogelj, R. B. Skeie, P. Nolan, R. Séférian acknowledge support from the European Union's Horizon 2020 research and innovation program under grant agreement No 820829 (CONSTRAIN). E. Tourigny, T. Ilyina and H. Li acknowledge support from the European Union's Horizon 2020 research and innovation program under grant agreement No 821003 (4C). C. Timmreck is supported from the Deutsche Forschungsgemeinschaft DFG (FOR2820, TI 344/2–1). MPI‐ESM simulations were performed at the German Climate Computing Center (DKRZ). We acknowledge DKRZ colleague Martin Schupfner for cmorizing and publishing the MPI‐ESM model simulations. S. T. Rumbold was funded by the National Environmental Research Council (NERC) national capability grant for the UK Earth System Modeling project, grant NE/N017951/1. M. Wu, H. Wang and K. Calvin acknowledge support by the U.S. Department of Energy (DOE), Office of Science, Office of Biological and Environmental Research, Earth and Environmental System Modeling program as part of the Energy Exascale Earth System Model (E3SM) project. The Pacific Northwest National Laboratory (PNNL) is operated for DOE by Battelle Memorial Institute under contract DE‐AC05‐76RLO1830. N. Oshima, T. Koshiro, and M. Deushi were supported by the Japan Society for the Promotion of Science (grant numbers: JP18H03363, JP18H05292, JP19K12312, and JP20K04070), the Environment Research and Technology Development Fund (JPMEERF20202003 and JPMEERF20205001) of the Environmental Restoration and Conservation Agency of Japan, the Integrated Research Program for Advancing Climate Models (TOUGOU) grant number JPMXD0717935561 from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan, and the Arctic Challenge for Sustainability II (ArCS II), Program Grant Number JPMXD1420318865. S.F. acknowledges funding for the Hans‐Ertel‐Center for Weather Research “Climate Monitoring and Diagnostic” (ID: BMVI/DWD 4818DWDP5A, https://www.herz.uni-bonn.de) and the Collaborative Research Center “Earth, evolution at the dry limit” (ID: DFG 68236062, https://sfb1211.uni-koeln.de). D. Olivié and J. Tjiputra acknowledge the Research Council of Norway funded projects INES (270061) and KeyClim (295046). Simulations of MIROC‐ES2L are supported by the TOUGOU project "Integrated Research Program for Advancing Climate Models" (grant number: JPMXD0717935715) of the Ministry of Education, Culture, Sports, Science, and Technology of Japan (MEXT). MIROC‐team acknowledges JAMSTEC for use of the Earth Simulator supercomputer. Simulations of UKESM1 and analysis of data were supported by the Joint UK BEIS/Defra Met Office Hadley Center Climate Program (GA01101). We gratefully acknowledge help from Martine Michou for setting up the model configuration used in this work and for processing of data from CNRM‐ESM2‐1. P. Nabat, C. Cassout and R. Séférian, thank the support of the team in charge of the CNRM‐CM climate model. Supercomputing time was provided by the Meteo‐France/DSI supercomputing center. Simulations of GISS‐E2‐1‐G were supported by NASA's Rapid Response and Novel Research in Earth Science program. Resources supporting this work were provided by the NASA High‐End Computing (HEC) Program through the NASA Center for Climate Simulation (NCCS) at Goddard Space Flight Center. We gratefully acknowledge Susanne Bauer, Gregory Faluvegi, Kenneth Lo, and Reto Ruedy for their assistance in preparing simulations and processing output. Y. Yang acknowledges the National Key Research and Development Program of China (Grant 2019YFA0606800 and 2020YFA0607803). S. Yang acknowledges support from the Danish National Center for Climate Research (Nationalt Center for Klimaforskning, NCKF).Peer Reviewed"Article signat per 49 autors/es: Chris D. Jones, Jonathan E. Hickman, Steven T. Rumbold, Jeremy Walton, Robin D. Lamboll , Ragnhild B. Skeie, Stephanie Fiedler, Piers M. Forster, Joeri Rogelj, Manabu Abe, Michael Botzet, Katherine Calvin, Christophe Cassou, Jason N.S. Cole, Paolo Davini, Makoto Deushi, Martin Dix, John C. Fyfe, Nathan P. Gillett, Tatiana Ilyina, Michio Kawamiya, Maxwell Kelley, Slava Kharin, Tsuyoshi Koshiro, Hongmei Li, Chloe Mackallah, Wolfgang A. Müller, Pierre Nabat, Twan van Noije, Paul Nolan, Rumi Ohgaito, Dirk Olivié, Naga Oshima, Jose Parodi, Thomas J. Reerink, Lili Ren, Anastasia Romanou, Roland Séférian, Yongming Tang, Claudia Timmreck , Jerry Tjiputra, Etienne Tourigny , Kostas Tsigaridis, Hailong Wang, Mingxuan Wu, Klaus Wyse,r Shuting Yang, Yang Yang, Tilo Ziehn"Postprint (published version

Urban mobility and transportation

Urban areas are developing quickly, innovative technologies grant enlarged scope for mobility management. According to literature, 50% of world population and as much as 75% of EU population live in cities, where the majority of GDP is generated. CO2 is responsible of 75% GHG worldwide and transportation is worth around 20% of this share and the contribution is rising, in particular in urban areas. Besides pollution and noise, also collisions (70% of which in urban areas) and congestion - which is worth around 1% of EU GDP in terms of time lost due to delay suffered - are negative externalities. Finally, due to urban sprawl induced by car-centric cultural regimen under the justification of cheaper land costs, the need to travel has been growing notwithstanding economic downturns, resulting in an increased threat of social exclusion for those who cannot afford a car. The attitude towards urban transportation has shifted from laissez-faire to deep concern: as far as EU is concerned, the Action plan on Urban Mobility (2009) recommended the adoption of Sustainable Urban Mobility Plans (SUMPs), the 2011 White Paper envisaged SUMPs to become mandatory for cities over 100,000 inhabitants and a base requisite to access to EU Funds. The 2013 Guidelines and the 2015 EC Urban Mobility Package have further established the SUMP policy. In 2015, UN adopted the “Agenda for sustainable development 2030” (7 out of 17 objectives deal with transportation) and a new worldwide agreement on climate has been signed in Paris. Finally, the funding foreseen by EU research project H2020 (8,2% of the total budget allocated on transportation) will further encourage the investigation of new strategies and technologies. SUMPs emphasize long term vision, the active involvement of citizen and stakeholders (Priester et al., 2014), the setting of targets, measures and a radical reform of regulatory and funding framework to avoid start-and-stop approach (Hickman et al., 2013; Stephenson et al., 2018). Nevertheless, the commitment level is different: developing countries would rather urge to build more and modern infrastructures, leaving the environment as a secondary priority. SUMPs are expected to find solution to road congestion and policy fragmentation between documents (Baidan, 2016). According to EU CIVITAS project’s outcomes, the implementation of SUMPs can be hindered by pro-car & infrastructure building lobbyism, inefficient planning - monitoring – dissemination, lack of stakeholder involvement and support, excessive outsourcing, fluctuation of political commitment over time (Ibeas et al., 2011; Persia et al., 2016), inadequate coordination among policy tiers and plans (Stephenson et al., 2018), unsupportive or inappropriate regulation and financial structures, poor or missing data and reliance to business-as-usual scenarios. The topics facing less acceptance have been accessibility, logistic, traffic control, cycling and walking measures (Bruhova Foltynova & Jordova, 2014)