@article{TrainiKleinertBittmann2021, author = {Traini, Claudia and Kleinert, Corinna and Bittmann, Felix}, title = {How does exposure to a different school track influence learning progress?}, series = {Research in social stratification and mobility}, volume = {76}, journal = {Research in social stratification and mobility}, publisher = {Elsevier}, address = {Amsterdam [u.a.]}, issn = {0276-5624}, doi = {10.1016/j.rssm.2021.100625}, pages = {285 -- 298}, year = {2021}, abstract = {German secondary education is known for its early, strict selection of students into different schooling tracks based on prior academic performance, based on the assumption that students learn more efficiently when the learning environment is tailored to their individual abilities and needs. While much previous research has shown that entry into tracks is socially selective, less is known whether there are effects of being exposed to a particular school track on educational success and which mechanisms are contributing to these effects. We investigate this question by comparing the learning progress in reading and mathematics of students in the upper and intermediate schooling track over five years of secondary schooling, based on large-scale German-wide longitudinal data (NEPS-SC3). Even when restricting our sample to a group of students with similar preconditions and controlling for skills at the beginning of secondary schooling, we find that the learning progress in the upper track is higher for both domains, suggesting scissor effects of track exposure. It is mainly the average performance level of the class, and to a lesser degree its social background composition, which mediates these effects. In contrast, migration background composition of the class and instructional quality perceived by students hardly contribute to explaining increasing learning gains in the upper track.}, language = {en} } @phdthesis{Sterzel2019, author = {Sterzel, Till}, title = {Analyzing global typologies of socio-ecological vulnerability}, doi = {10.25932/publishup-42883}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-428837}, school = {Universit{\"a}t Potsdam}, pages = {137}, year = {2019}, abstract = {On a planetary scale human populations need to adapt to both socio-economic and environmental problems amidst rapid global change. This holds true for coupled human-environment (socio-ecological) systems in rural and urban settings alike. Two examples are drylands and urban coasts. Such socio-ecological systems have a global distribution. Therefore, advancing the knowledge base for identifying socio-ecological adaptation needs with local vulnerability assessments alone is infeasible: The systems cover vast areas, while funding, time, and human resources for local assessments are limited. They are lacking in low an middle-income countries (LICs and MICs) in particular. But places in a specific socio-ecological system are not only unique and complex - they also exhibit similarities. A global patchwork of local rural drylands vulnerability assessments of human populations to socio-ecological and environmental problems has already been reduced to a limited number of problem structures, which typically cause vulnerability. However, the question arises whether this is also possible in urban socio-ecological systems. The question also arises whether these typologies provide added value in research beyond global change. Finally, the methodology employed for drylands needs refining and standardizing to increase its uptake in the scientific community. In this dissertation, I set out to fill these three gaps in research. The geographical focus in my dissertation is on LICs and MICs, which generally have lower capacities to adapt, and greater adaptation needs, regarding rapid global change. Using a spatially explicit indicator-based methodology, I combine geospatial and clustering methods to identify typical configurations of key factors in case studies causing vulnerability to human populations in two specific socio-ecological systems. Then I use statistical and analytical methods to interpret and appraise both the typical configurations and the global typologies they constitute. First, I improve the indicator-based methodology and then reanalyze typical global problem structures of socio-ecological drylands vulnerability with seven indicator datasets. The reanalysis confirms the key tenets and produces a more realistic and nuanced typology of eight spatially explicit problem structures, or vulnerability profiles: Two new profiles with typically high natural resource endowment emerge, in which overpopulation has led to medium or high soil erosion. Second, I determine whether the new drylands typology and its socio-ecological vulnerability concept advance a thematically linked scientific debate in human security studies: what drives violent conflict in drylands? The typology is a much better predictor for conflict distribution and incidence in drylands than regression models typically used in peace research. Third, I analyze global problem structures typically causing vulnerability in an urban socio-ecological system - the rapidly urbanizing coastal fringe (RUCF) - with eleven indicator datasets. The RUCF also shows a robust typology, and its seven profiles show huge asymmetries in vulnerability and adaptive capacity. The fastest population increase, lowest income, most ineffective governments, most prevalent poverty, and lowest adaptive capacity are all typically stacked in two profiles in LICs. This shows that beyond local case studies tropical cyclones and/or coastal flooding are neither stalling rapid population growth, nor urban expansion, in the RUCF. I propose entry points for scaling up successful vulnerability reduction strategies in coastal cities within the same vulnerability profile. This dissertation shows that patchworks of local vulnerability assessments can be generalized to structure global socio-ecological vulnerabilities in both rural and urban socio-ecological systems according to typical problems. In terms of climate-related extreme events in the RUCF, conflicting problem structures and means to deal with them are threatening to widen the development gap between LICs and high-income countries unless successful vulnerability reduction measures are comprehensively scaled up. The explanatory power for human security in drylands warrants further applications of the methodology beyond global environmental change research in the future. Thus, analyzing spatially explicit global typologies of socio-ecological vulnerability is a useful complement to local assessments: The typologies provide entry points for where to consider which generic measures to reduce typical problem structures - including the countless places without local assessments. This can save limited time and financial resources for adaptation under rapid global change.}, language = {en} } @phdthesis{Schrauth2022, author = {Schrauth, Philipp}, title = {Agglomerations, air quality and urban transformation}, doi = {10.25932/publishup-58608}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-586087}, school = {Universit{\"a}t Potsdam}, pages = {253}, year = {2022}, abstract = {Die vorliegende Dissertation stellt empirische Untersuchungen {\"u}ber den Zusammenhang von st{\"a}dtischem Leben und dessen {\"o}konomische Kosten, insbesondere f{\"u}r die Umwelt, an. Dabei werden zum einen bestehende Forschungsl{\"u}cken des Einflusses von Bev{\"o}lkerungsdichte auf die Luftqualit{\"a}t geschlossen und zum anderen innovative Politikmaßnahmen im Verkehrsbereich untersucht, die Ballungsr{\"a}ume nachhaltiger gestalten sollen. Im Zentrum der Betrachtungen stehen Luftverschmutzung, Staus und Verkehrsunf{\"a}lle, die f{\"u}r Fragen der allgemeinen Wohlfahrt bedeutend sind und erhebliche Kostenfaktoren f{\"u}r urbanes Leben darstellen. Von ihnen ist ein betr{\"a}chtlicher Anteil der Weltbev{\"o}lkerung betroffen. W{\"a}hrend im Jahr 2018 bereits 55\% der Menschen weltweit in St{\"a}dten lebten, soll dieser Anteil bis zum Jahr 2050 ungef{\"a}hr 68\% betragen. Die vier in sich geschlossenen Kapitel dieser Arbeit lassen sich in zwei Abschnitte aufteilen: In den Kapiteln 2 und 3 werden neue kausale Erkenntnisse {\"u}ber das komplexe Zusammenspiel von st{\"a}dtischen Strukturen und Luftverschmutzung erbracht. Kapitel 4 und 5 untersuchen anschließend politische Maßnahmen zur F{\"o}rderung nicht-motorisierter Verkehrsmittel und deren Einfluss auf Luftqualit{\"a}t sowie Staugeschehen und Verkehrsunf{\"a}lle.}, language = {en} } @techreport{Schrauth2022, type = {Working Paper}, author = {Schrauth, Philipp}, title = {The Causal Effect of Cycling Infrastructure on Traffic and Accidents}, series = {CEPA Discussion Papers}, journal = {CEPA Discussion Papers}, number = {48}, issn = {2628-653X}, doi = {10.25932/publishup-55335}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-553359}, pages = {56}, year = {2022}, abstract = {This paper analyzes the effect of new bicycle lanes on traffic volume, congestion, and accidents. Crucially, the new bike lanes replace existing car lanes thereby reducing available space for motorized traffic. In order to obtain causal estimates, I exploit the quasi-random timing and location of the newly built cycle lanes. Using an event study design, a two-way fixed effects model and the synthetic control group method on geo-coded data, I show that the construction of pop-up bike lanes significantly reduced average car speed by 8 to 12 percentage points (p.p.) and up to 16 p.p. in peak traffic hours. In contrast, the results for car volume are modest, while the data does not allow for a conclusive judgment of accidents.}, language = {en} } @misc{FritzRosaSicard2018, author = {Fritz, Michael Andre and Rosa, Stefanie and Sicard, Adrien}, title = {Mechanisms Underlying the Environmentally Induced Plasticity of Leaf Morphology}, series = {Frontiers in genetics}, volume = {9}, journal = {Frontiers in genetics}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-8021}, doi = {10.3389/fgene.2018.00478}, pages = {25}, year = {2018}, abstract = {The primary function of leaves is to provide an interface between plants and their environment for gas exchange, light exposure and thermoregulation. Leaves have, therefore a central contribution to plant fitness by allowing an efficient absorption of sunlight energy through photosynthesis to ensure an optimal growth. Their final geometry will result from a balance between the need to maximize energy uptake while minimizing the damage caused by environmental stresses. This intimate relationship between leaf and its surroundings has led to an enormous diversification in leaf forms. Leaf shape varies between species, populations, individuals or even within identical genotypes when those are subjected to different environmental conditions. For instance, the extent of leaf margin dissection has, for long, been found to inversely correlate with the mean annual temperature, such that Paleobotanists have used models based on leaf shape to predict the paleoclimate from fossil flora. Leaf growth is not only dependent on temperature but is also regulated by many other environmental factors such as light quality and intensity or ambient humidity. This raises the question of how the different signals can be integrated at the molecular level and converted into clear developmental decisions. Several recent studies have started to shed the light on the molecular mechanisms that connect the environmental sensing with organ-growth and patterning. In this review, we discuss the current knowledge on the influence of different environmental signals on leaf size and shape, their integration as well as their importance for plant adaptation.}, language = {en} }