@article{PohlMoering2021,
  author    = {Pohl, Manuela and M{\"o}ring, Sebastian},
  title     = {L{\"u}ckenf{\"u}ller - Vom Nutzen der Leerstellen in Adventure-Games beim Sprachenlernen},
  series = {DIGAREC Series},
  journal   = {DIGAREC Series},
  number    = {9},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  isbn      = {978-3-86956-511-8},
  issn      = {1867-6219},
  doi       = {10.25932/publishup-52675},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-526754},
  pages     = {208 -- 244},
  year      = {2021},
  abstract  = {In diesem Beitrag schlagen wir am Beispiel des Computerspiels Brothers vor, wie narrative und Gameplay-Leerstellen in Sprachlern-Settings genutzt werden k{\"o}nnen. Wir stellen die Funktion von Leerstellen beim Lesen (Iser), bei Computerspielen (Aarseth und Pias) und in der Sprachdidaktik vor und machen im Anschluss konkrete Vorschl{\"a}ge, wie das Spiel in Sprachlern-Settings eingesetzt werden kann.},
  language  = {de}
}
@article{Pohl2020,
  author    = {Pohl, Manuela},
  title     = {„The game's afoot!"},
  series = {DIGAREC Series},
  journal   = {DIGAREC Series},
  number    = {08},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  isbn      = {978-3-86956-467-8},
  issn      = {1867-6219},
  doi       = {10.25932/publishup-43067},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-430672},
  pages     = {104 -- 133},
  year      = {2020},
  abstract  = {Computerspiele bieten - verstanden als Text, als popkulturelles Artefakt, als Lerngelegenheit und vieles mehr - auch f{\"u}r den Einsatz im Fremdsprachenunterricht zahlreiche M{\"o}glichkeiten, curricular vorgegebene Kompetenzen auszubilden. Nicht nur kann die Auseinandersetzung mit Computerspielen einen Beitrag zur fachintegrativen Vermittlung von Medienkompetenz leisten, sondern ebenso dazu genutzt werden, Handlungen zu simulieren, in denen Sch{\"u}lerinnen und Sch{\"u}ler fremdsprachig (inter-)agieren. Der folgende Beitrag versucht daher, exemplarisch zwei Computerspiele auf ihr Potential f{\"u}r den Einsatz im Fremdsprachenunterricht Englisch zu untersuchen. Er versteht sich als praktischer Beitrag, der Einblick in didaktisch-methodische {\"U}berlegungen bietet, welche die Auseinandersetzung mit den zwei exemplarisch ausgew{\"a}hlten Spielen, HER STORY (2015) und 1979 REVOLUTION: BLACK FRIDAY (2016), in den Blick nehmen.},
  language  = {de}
}
@inproceedings{Pohl2008,
  author    = {Pohl, Kirsten},
  title     = {Ethical reflection and emotional involvement in computer games},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-24652},
  year      = {2008},
  abstract  = {This paper focuses on the way computer games refer to the context of their formation and ask how they might stimulate the user's understanding of the world around him. The central question is: Do computer games have the potential to inspire our reflection about moral and ethical issues? And if so, by which means do they achieve this? Drawing on concepts of the ethical criticism in literary studies as proposed by Wayne C. Booth and Martha Nussbaum, I will argue in favor of an ethical criticism for computer games. Two aspects will be brought into focus: the ethical reflection in the artifact as a whole, and the recipient's emotional involvement. The paper aims at evaluating the interaction of game content and game structure in order to give an adequate insight into the way computer games function and affect us.},
  language  = {en}
}
@misc{Wollina2010,
  type      = {Master Thesis},
  author    = {Wollina, Markus},
  title     = {Das Leben in einem ostdeutschen Plattenbaugebiet aus der Perspektive seiner Einwohner : eine qualitative Studie in Strausberg-Hegerm{\"u}hle},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57913},
  school      = {Universit{\"a}t Potsdam},
  year      = {2010},
  abstract  = {Architektur und St{\"a}dtebau des Sozialismus haben nach der politischen Wende der Jahre 1989-1991 einen erheblichen Wertungswandel erfahren. Insbesondere die in industrieller Bauweise errichteten Quartiere des komplexen Wohnungsbaus, die einstmals privilegierte Wohngegenden waren, haben heute oftmals den Ruf von „Ghettos". Die vorliegende Arbeit m{\"o}chte einen Beitrag dazu leisten, dieses Bild zu korrigieren und das {\"o}ffentliche Image von Plattenbausiedlungen zu verbessern. Dazu wurde anhand des ostdeutschen Plattenbaugebietes Strausberg-Hegerm{\"u}hle untersucht, welche Faktoren die positive Identifikation der Bewohner mit ihrem Viertel beg{\"u}nstigen. Ziel der Arbeit ist, damit Anregungen f{\"u}r die Praxis lokal engagierter B{\"u}rger, Kommunalpolitiker, Wohnungsgesellschaften und Verwaltungen zu geben. Das Wohngebiet „Hegerm{\"u}hle" in der brandenburgischen Mittelstadt Strausberg wurde in den 1980er Jahren gebaut. Die Bev{\"o}lkerung Hegerm{\"u}hles war bis 1990 stark durch Mitarbeiter des Ministeriums f{\"u}r Nationale Verteidigung der Deutschen Demokratischen Republik gepr{\"a}gt. Die Wohnungen im Viertel waren wegen ihres hohen technischen Standards begehrt. Nach dem Ende der DDR erfuhr das Viertel einen starken Wandel seiner Sozialstruktur und bekam ein Image, das zwischen den Polen „graue Schlafstadt" und „sozialer Brennpunkt" angesiedelt ist. In diesem Wohngebiet wurde im zweiten Halbjahr 2009 eine qualitative Untersuchung durchgef{\"u}hrt. Neben mehreren in Bild- und Textform dokumentierten Feldexplorationen wurde eine Reihe von Interviews mit Personen gef{\"u}hrt, die aktuell in Hegerm{\"u}hle wohnen oder fr{\"u}her dort wohnten. Die Auswahl der Interviewpartner erfolgte nach der Methode des Theoretical Sampling (Glaser/Strauss), wobei eine m{\"o}glichst große Differenzierung des Samples nach Alter, Herkunft, Geschlecht und Beruf angestrebt wurde. Die Interviews wurden nach der Methode des Problemzentrierten Interviews (Witzel) gef{\"u}hrt und auf Grundlage des Konzepts der Grounded Theory (Glaser/Strauss) ausgewertet. F{\"u}r die Arbeit wurden acht Interviews ausgew{\"a}hlt, in denen die Interviewten Auskunft geben {\"u}ber die folgenden Themen: die Umst{\"a}nde ihres Zuzugs nach Hegerm{\"u}hle, die Entwicklung des Wohngebiets seitdem, das Image Hegerm{\"u}hles, ihr eigenes Verh{\"a}ltnis zum Viertel und die Perspektiven des Wohngebiets. Als Ergebnis der Arbeit l{\"a}sst sich festhalten, dass die positive Identifikation mit dem Wohngebiet am st{\"a}rksten durch die problematische Sozialstruktur behindert wird, die in hohem Maße von Arbeitslosigkeit und sozialen Desintegrationserscheinungen gepr{\"a}gt ist. Davon abgesehen {\"u}berwiegen pragmatische Kriterien bei der Bewertung des Wohngebiets. Die gute infrastrukturelle Ausstattung Hegerm{\"u}hles mit Einkaufs-, Betreuungs- und Erholungsm{\"o}glichkeiten wurde von allen Befragten positiv hervorgehoben. Diese Faktoren sind jedoch genau so auch in anderen Orten zu finden und damit nicht geeignet, eine Identifikation mit einem spezifischen Ort zu bef{\"o}rdern. Von den Befragten wurde daher auch mehrfach auf das Fehlen von Merkmalen hingewiesen, die Hegerm{\"u}hle auszeichnen und es von anderen Vierteln abheben. Dagegen war die Lokalidentit{\"a}t bei den Interviewpartnern am st{\"a}rksten, die den Aufbau Hegerm{\"u}hles in den 1980er Jahren pers{\"o}nlich miterlebt haben. Die Arbeit schließt darum mit {\"U}berlegungen, wie diese Erfahrung einer Ortsgeschichte, die Bedeutung f{\"u}r die eigene Biografie hat, anderen Einwohnern vermittelt werden kann. Zwei m{\"o}gliche Konzepte werden vorgeschlagen: a) die Erforschung und Vermittlung der Wohngebietsgeschichte, sowie b) die Schaffung und Pflege r{\"a}umlicher Identifikationspunkte, die die lokale Geschichte, Landschaft und andere Besonderheiten des Viertels im Alltag erfahrbar machen. Beispielsweise k{\"o}nnen Kunstwerke im {\"o}ffentlichen Raum oder Gedenktafeln als Ankn{\"u}pfungspunkte einer ortsbezogenen Identit{\"a}t dienen und ein Gef{\"u}hl pers{\"o}nlicher Verbundenheit mit dem Wohnort best{\"a}rken. Damit k{\"o}nnte unabh{\"a}ngig von pragmatischen Faktoren eine Bindung an den Ort beg{\"u}nstigt und die Bereitschaft der Einwohner erh{\"o}ht werden, sich f{\"u}r die Verbesserung der Verh{\"a}ltnisse im Wohngebiet einzusetzen.},
  language  = {de}
}
@article{Pohl2021,
  author    = {Pohl, Martin},
  title     = {Time-dependent treatment of cosmic-ray spectral steepening due to turbulence driving},
  series = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  volume    = {921},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  number    = {2},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  issn      = {1538-4357},
  doi       = {10.3847/1538-4357/ac21cf},
  pages     = {6},
  year      = {2021},
  abstract  = {Cosmic-ray acceleration at non-relativistic shocks relies on scattering by turbulence that the cosmic rays drive upstream of the shock. We explore the rate of energy transfer from cosmic rays to non-resonant Bell modes and the spectral softening it implies. Accounting for the finite time available for turbulence driving at supernova-remnant shocks yields a smaller spectral impact than found earlier with steady-state considerations. Generally, for diffusion scaling with the Bohm rate by a factor eta, the change in spectral index is at most eta divided by the Alfvenic Mach number of the thermal sub-shock. For M (A) less than or similar to 50 it is well below this limit. Only for very fast shocks and very efficient cosmic-ray acceleration can the change in spectral index reach 0.1. For standard SNR parameters, it is negligible. Independent confirmation is derived by considering the synchrotron energy losses of electrons: if intense nonthermal multi-keV emission is produced, the energy loss, and hence the spectral steepening, is very small for hadronic cosmic rays that produce TeV-band gamma-ray emission.},
  language  = {en}
}
@article{HoffmannPohlJurischetal.2017,
  author    = {Hoffmann, Matthias and Pohl, Madlen and Jurisch, N. and Prescher, Anne-Katrin and Campa, E. Mendez and Hagemann, Ulrike and Remus, R. and Verch, G. and Sommer, Michael and Augustin, J.},
  title     = {Maize carbon dynamics are driven by soil erosion state and plant phenology rather than nitrogen fertilization form},
  series = {Soil \& tillage research : an international journal on research and development in soil tillage and field traffic, and their relationships with soil environment, land use and crop production},
  volume    = {175},
  journal   = {Soil \& tillage research : an international journal on research and development in soil tillage and field traffic, and their relationships with soil environment, land use and crop production},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0167-1987},
  doi       = {10.1016/j.still.2017.09.004},
  pages     = {255 -- 266},
  year      = {2017},
  abstract  = {Carbon (C) stored in soils represents the largest C pool of terrestrial ecosystems and consequently plays a crucial role in the global C cycle. So far, it is widely unclear to what extent different land uses and land use change influence soil C storage. The hummocky ground moraine landscape of northeastern Germany is characterized by distinct small-scale soil heterogeneity on the one hand, and intensive energy crop cultivation on the other. Both factors are assumed to significantly influence gaseous C exchange; as such, they likely drive soil organic carbon (SOC) stock dynamics in terrestrial agricultural ecosystems. To date, it is not clear to what extent N fertilization forms, which are associated with energy crop cultivation (e.g., application of biogas fermentation residues) and soil type relative to soil erosion state, influence soil C dynamics, nor is it clear whether one of these factors is more important than the other. To investigate the influence of soil erosion state and N fertilization form on soil C dynamics, we present dynamic and seasonal net ecosystem carbon balances (NECB) as a proxy for changes in soil organic carbon stocks. Measurements were conducted for maize (Zea mays L.) at five sites in the "CarboZALF-D" experimental field during the 2011 growing season. Measurement sites represent different soil erosion states (non-eroded Albic Luvisols, extremely eroded Calcaric Regosols and depositional Endogleyic Colluvic Regosols) and N fertilization forms (100\% mineral fertilizer, 50\% mineral and 50\% organic fertilizer, and 100\% organic fertilizer). Fertilization treatments were established on the Albic Luvisol. Net ecosystem CO2 exchange (NEE) and ecosystem respiration (R-eco) were measured every four weeks using a dynamic flow-through non-steady-state closed manual chamber system. Gap filling was performed based on empirical temperature and PAR dependency functions and was used to derive daily NEE values. In parallel, daily above-ground biomass production (NPFshoot) was estimated using a logistic growth equation, fitted on periodic biomass samples. Finally, C dynamics were calculated as the balance of daily NEE and NPPshoot based on the initial C input due to organic fertilization. Resulting NECB varied from pronounced soil C losses at the Endogleyic Colluvic Regosol (592 g C m(-2)) to soil C gains at the Calcaric Regosol (-124 g C m(-2)). Minor to modest C losses were observed for the Albic Luvisol. Compared to N fertilization forms, soil erosion states generally had a stronger impact on derived NECB. However, interannual variations in plant phonology and interactions between soil erosion states and fertilization forms might result in different NECB values over multiple years. Hence, long-term measurements of different fertilization treatments on characteristic soil landscape elements are needed.},
  language  = {en}
}
@misc{PohlHoffmannHagemannetal.2015,
  author    = {Pohl, Madlen and Hoffmann, M. and Hagemann, Ulrike and Giebels, M. and Albiac Borraz, E. and Sommer, Michael and Augustin, J{\"u}rgen},
  title     = {Dynamic C and N stocks},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {496},
  issn      = {1866-8372},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-408184},
  pages     = {16},
  year      = {2015},
  abstract  = {The drainage and cultivation of fen peatlands create complex small-scale mosaics of soils with extremely variable soil organic carbon (SOC) stocks and groundwater levels (GWLs). To date, the significance of such sites as sources or sinks for greenhouse gases such as CO2 and CH4 is still unclear, especially if the sites are used for cropland. As individual control factors such as GWL fail to account for this complexity, holistic approaches combining gas fluxes with the underlying processes are required to understand the carbon (C) gas exchange of drained fens. It can be assumed that the stocks of SOC and N located above the variable GWL - defined as dynamic C and N stocks - play a key role in the regulation of the plant- and microbially mediated CO2 fluxes in these soils and, inversely, for CH4. To test this assumption, the present study analysed the C gas exchange (gross primary production - GPP; ecosystem respiration - R-eco; net ecosystem exchange - NEE; CH4) of maize using manual chambers for 4 years. The study sites were located near Paulinenaue, Germany, where we selected three soil types representing the full gradient of GWL and SOC stocks (0-1 m) of the landscape: (a) Haplic Arenosol (AR; 8 kg C m(-2)); (b) Mollic Gleysol (GL; 38 kg C m(-2)); and (c) Hemic Histosol (HS; 87 kg C m(-2)). Daily GWL data were used to calculate dynamic SOC (SOCdyn) and N (N-dyn) stocks. Average annual NEE differed considerably among sites, ranging from 47 +/- 30 g C m(-2) yr(-1) in AR to -305 +/- 123 g C m(-2) yr(-1) in GL and -127 +/- 212 g C m(-2) yr(-1) in HS. While static SOC and N stocks showed no significant effect on C fluxes, SOCdyn and N-dyn and their interaction with GWL strongly influenced the C gas exchange, particularly NEE and the GPP : R-eco ratio. Moreover, based on nonlinear regression analysis, 86\% of NEE variability was explained by GWL and SOCdyn. The observed high relevance of dynamic SOC and N stocks in the aerobic zone for plant and soil gas exchange likely originates from the effects of GWL-dependent N availability on C formation and transformation processes in the plant-soil system, which promote CO2 input via GPP more than CO2 emission via R-eco. The process-oriented approach of dynamic C and N stocks is a promising, potentially generalisable method for system-oriented investigations of the C gas exchange of groundwater-influenced soils and could be expanded to other nutrients and soil characteristics. However, in order to assess the climate impact of arable sites on drained peatlands, it is always necessary to consider the entire range of groundwater-influenced mineral and organic soils and their respective areal extent within the soil landscape.},
  language  = {en}
}
@article{FraschettiPohl2017,
  author    = {Fraschetti, F. and Pohl, Martin},
  title     = {Particle acceleration model for the broad-band baseline spectrum of the Crab nebula},
  series = {Monthly notices of the Royal Astronomical Society},
  volume    = {471},
  journal   = {Monthly notices of the Royal Astronomical Society},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  issn      = {0035-8711},
  doi       = {10.1093/mnras/stx1833},
  pages     = {4866 -- 4874},
  year      = {2017},
  abstract  = {We develop a simple one-zone model of the steady-state Crab nebula spectrum encompassing both the radio/soft X-ray and the GeV/multi-TeV observations. By solving the transport equation for GeV-TeV electrons injected at the wind termination shock as a log-parabola momentum distribution and evolved via energy losses, we determine analytically the resulting differential energy spectrum of photons. We find an impressive agreement with the observed spectrum of synchrotron emission, and the synchrotron self-Compton component reproduces the previously unexplained broad 200-GeV peak that matches the Fermi/Large Area Telescope (LAT) data beyond 1 GeV with the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) data. We determine the parameters of the single log-parabola electron injection distribution, in contrast with multiple broken power-law electron spectra proposed in the literature. The resulting photon differential spectrum provides a natural interpretation of the deviation from power law customarily fitted with empirical multiple broken power laws. Our model can be applied to the radio-to-multi-TeV spectrum of a variety of astrophysical outflows, including pulsar wind nebulae and supernova remnants, as well as to interplanetary shocks.},
  language  = {en}
}
@article{ChenPohlBottcheretal.2016,
  author    = {Chen, Xuhui and Pohl, Martin and Bottcher, Markus and Gao, Shan},
  title     = {Particle diffusion and localized acceleration in inhomogeneous AGN jets - II. Stochastic variation},
  series = {Monthly notices of the Royal Astronomical Society},
  volume    = {458},
  journal   = {Monthly notices of the Royal Astronomical Society},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  issn      = {0035-8711},
  doi       = {10.1093/mnras/stw528},
  pages     = {3260 -- 3271},
  year      = {2016},
  abstract  = {We study the stochastic variation of blazar emission under a 2D spatially resolved leptonic jet model we previously developed. Random events of particle acceleration and injection in small zones within the emission region are assumed to be responsible for flux variations. In addition to producing spectral energy distributions that describe the observed flux of Mrk 421, we further analyse the timing properties of the simulated light curves, such as the power spectral density (PSD) at different bands, flux-flux correlations, aswell as the cross-correlation function between X-rays and TeV gamma-rays. We find spectral breaks in the PSD at a time-scale comparable to the dominant characteristic time-scale in the system, which is usually the predefined decay time-scale of an acceleration event. Cooling imposes a delay, and so PSDs taken at lower energy bands in each emission component (synchrotron or inverse Compton) generally break at longer time-scales. The flux-flux correlation between X-rays and TeV gamma-rays can be either quadratic or linear, depending on whether or not there are large variation of the injection into the particle acceleration process. When the relationship is quadratic, the TeV flares lag the X-ray flares, and the optical and GeV flares are large enough to be comparable to the ones in X-ray. When the relationship is linear, the lags are insignificant, and the optical and GeV flares are small.},
  language  = {en}
}
@article{KobzarNiemiecPohletal.2017,
  author    = {Kobzar, Oleh and Niemiec, Jacek and Pohl, Martin and Bohdan, Artem},
  title     = {Spatio-temporal evolution of the non-resonant instability in shock precursors of young supernova remnants},
  series = {Monthly notices of the Royal Astronomical Society},
  volume    = {469},
  journal   = {Monthly notices of the Royal Astronomical Society},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  organization    = {ANTARES Collaboration;H E S S Collaboration},
  issn      = {0035-8711},
  doi       = {10.1093/mnras/stx1201},
  pages     = {4985 -- 4998},
  year      = {2017},
  abstract  = {A non-resonant cosmic ray (CR) current-driven instability may operate in the shock precursors of young supernova remnants and be responsible for magnetic-field amplification, plasma heating and turbulence. Earlier simulations demonstrated magnetic-field amplification, and in kinetic studies a reduction of the relative drift between CRs and thermal plasma was observed as backreaction. However, all published simulations used periodic boundary conditions, which do not account for mass conservation in decelerating flows and only allow the temporal development to be studied. Here we report results of fully kinetic particle-in-cell simulations with open boundaries that permit inflow of plasma on one side of the simulation box and outflow at the other end, hence allowing an investigation of both the temporal and the spatial development of the instability. Magnetic-field amplification proceeds as in studies with periodic boundaries and, observed here for the first time, the reduction of relative drifts causes the formation of a shock-like compression structure at which a fraction of the plasma ions are reflected. Turbulent electric field generated by the non-resonant instability inelastically scatters CRs, modifying and anisotropizing their energy distribution. Spatial CR scattering is compatible with Bohm diffusion. Electromagnetic turbulence leads to significant non-adiabatic heating of the background plasma maintaining bulk equipartition between ions and electrons. The highest temperatures are reached at sites of large-amplitude electrostatic fields. Ion spectra show supra-thermal tails resulting from stochastic scattering in the turbulent electric field. Together, these modifications in the plasma flow will affect the properties of the shock and particle acceleration there.},
  language  = {en}
}