TY - JOUR A1 - Smieliauskas, Wally A1 - Bewley, Kathryn A1 - Gronewold, Ulfert A1 - Menzefricke, Ulrich T1 - Misleading Forecasts in Accounting Estimates BT - a Form of Ethical Blindness in Accounting Standards? JF - Journal of business ethics N2 - The current financial reporting environment, with its increasing use of accounting estimates, including fair value estimates, suggests that unethical accounting estimates may be a growing concern. This paper provides explanations and empirical evidence for why some types of accounting estimates in financial reporting may promote a form of ethical blindness. These types of ethical blindness can have an escalating effect that corrupts not only an individual or organization but also the accounting profession and the public interest it serves. Ethical blindness in the standards of professional accountants may be a factor in the extent of misreporting, and may have taken on new urgency as a result of the proposals to change the conceptual framework for financial reporting using international standards. The social consequences for users of financial statements can be huge. The acquittal of former Nortel executives on fraud charges related to accounting manipulations is viewed by many as legitimizing accounting gamesmanship. This decision illustrates that the courts may not be the best place to deal with ethical reporting issues. The courts may be relied on for only the most egregious unethical conduct and, even then, the accounting profession is ill equipped to assist the legal system in prosecuting accounting fraud unless the standards have been clarified. We argue that the problem of unethical reporting should be addressed by the accounting profession itself, preferably as a key part of the conceptual framework that supports accounting and auditing standards, and the codes of ethical conduct that underpin the professionalism of accountants. KW - Ethical accounting estimates KW - Estimation uncertainty KW - IASB accounting conceptual framework KW - Accounting standards KW - Auditing standards Y1 - 2016 U6 - https://doi.org/10.1007/s10551-016-3289-1 SN - 0167-4544 SN - 1573-0697 VL - 152 IS - 2 SP - 437 EP - 457 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Möring, Sebastian A1 - Leino, Olli Tapio T1 - Beyond games as political education BT - Neo-liberalism in the contemporary computer game form JF - Journal of Gaming & Virtual Worlds N2 - This article introduces the juxtaposed notions of liberal and neo-liberal gameplay in order to show that, while forms of contemporary game culture are heavily influenced by neo-liberalism, they often appear under a liberal disguise. The argument is grounded in Claus Pias’ idea of games as always a product of their time in terms of economic, political and cultural history. The article shows that romantic play theories (e.g. Schiller, Huizinga and Caillois) are circling around the notion of play as ‘free’, which emerged in parallel with the philosophy of liberalism and respective socio-economic developments such as the industrialization and the rise of the nation state. It shows further that contemporary discourse in computer game studies addresses computer game/play as if it still was the romantic form of play rooted in the paradigm of liberalism. The article holds that an account that acknowledges the neo-liberalist underpinnings of computer games is more suited to addressing contemporary computer games, among which are phenomena such as free to play games, which repeat the structures of a neo-liberal society. In those games the players invest time and effort in developing their skills, although their future value is mainly speculative – just like this is the case for citizens of neo-liberal societies. Y1 - 2016 U6 - https://doi.org/10.1386/jgvw.8.2.145_1 SN - 1757-191X VL - 8 IS - 2 SP - 145 EP - 161 PB - Intellect CY - Bristol ER - TY - JOUR A1 - Trautwein, Matthias A1 - Fredriksson, Kai A1 - Möller, Heiko Michael A1 - Exner, Thomas E. T1 - Automated assignment of NMR chemical shifts based on a known structure and 4D spectra JF - Journal of biomolecular NMR N2 - Apart from their central role during 3D structure determination of proteins the backbone chemical shift assignment is the basis for a number of applications, like chemical shift perturbation mapping and studies on the dynamics of proteins. This assignment is not a trivial task even if a 3D protein structure is known and needs almost as much effort as the assignment for structure prediction if performed manually. We present here a new algorithm based solely on 4D [H-1, N-15]-HSQC-NOESY-[H-1, N-15]-HSQC spectra which is able to assign a large percentage of chemical shifts (73-82 %) unambiguously, demonstrated with proteins up to a size of 250 residues. For the remaining residues, a small number of possible assignments is filtered out. This is done by comparing distances in the 3D structure to restraints obtained from the peak volumes in the 4D spectrum. Using dead-end elimination, assignments are removed in which at least one of the restraints is violated. Including additional information from chemical shift predictions, a complete unambiguous assignment was obtained for Ubiquitin and 95 % of the residues were correctly assigned in the 251 residue-long N-terminal domain of enzyme I. The program including source code is available at https://github.com/thomasexner/4Dassign. KW - Chemical shift assignment KW - Protein KW - 3D structure KW - 4D NOESY Y1 - 2016 U6 - https://doi.org/10.1007/s10858-016-0050-0 SN - 0925-2738 SN - 1573-5001 VL - 65 SP - 217 EP - 236 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Maier, Stefan K. A1 - Poluektov, Georgiy A1 - Jester, Stefan-S. A1 - Möller, Heiko Michael A1 - Hoeger, Sigurd T1 - Fast Oxidative Cyclooligomerization towards Low- and High-Symmetry Thiophene Macrocycles JF - Chemistry - a European journal N2 - Macrocycles with quaterthiophene subunits were obtained by cyclooligomerization by direct oxidative coupling of unsubstituted dithiophene moieties. The rings were closed with high selectivity by an α,β′-connection of the thiophenes as proven by NMR spectroscopy. The reaction of the precursor with terthiophene moieties yielded the symmetric α,α′-linked macrocycle in low yield together with various differently connected isomers. Blocking of the β-position of the half-rings yielded selectively the α,α′-linked macrocycle. Selected cyclothiophenes were investigated by scanning tunneling microscopy, which displayed the formation of highly ordered 2D crystalline monolayers. KW - cyclooligomers KW - scanning tunneling microscopy KW - self-assembled monolayers KW - shape-persistent macrocycles KW - thiophenes Y1 - 2016 U6 - https://doi.org/10.1002/chem.201503211 SN - 0947-6539 SN - 1521-3765 VL - 22 SP - 1379 EP - 1384 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Prestel, Andreas A1 - Möller, Heiko Michael T1 - Spatio-temporal control of cellular uptake achieved by photoswitchable cell-penetrating peptides JF - Chemical communications N2 - The selective uptake of compounds into specific cells of interest is a major objective in cell biology and drug delivery. By incorporation of a novel, thermostable azobenzene moiety we generated peptides that can be switched optically between an inactive state and an active, cell-penetrating state with excellent spatio-temporal control. Y1 - 2016 U6 - https://doi.org/10.1039/c5cc06848g SN - 1359-7345 SN - 1364-548X VL - 52 SP - 701 EP - 704 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Holert, Johannes A1 - Yücel, Onur A1 - Jagmann, Nina A1 - Prestel, Andreas A1 - Möller, Heiko Michael A1 - Philipp, Bodo T1 - Identification of bypass reactions leading to the formation of one central steroid degradation intermediate in metabolism of different bile salts in Pseudomonas sp strain Chol1 JF - Environmental microbiology Y1 - 2016 U6 - https://doi.org/10.1111/1462-2920.13192 SN - 1462-2912 SN - 1462-2920 VL - 18 SP - 3373 EP - 3389 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Boyd, A. J. A1 - Spence, Harlan E. A1 - Huang, Chia-Lin A1 - Reeves, Geoffrey D. A1 - Baker, Daniel N. A1 - Turner, D. L. A1 - Claudepierre, Seth G. A1 - Fennell, Joseph F. A1 - Blake, J. Bernard A1 - Shprits, Yuri Y. T1 - Statistical properties of the radiation belt seed population JF - Journal of geophysical research : Space physics N2 - We present a statistical analysis of phase space density data from the first 26 months of the Van Allen Probes mission. In particular, we investigate the relationship between the tens and hundreds of keV seed electrons and >1 MeV core radiation belt electron population. Using a cross-correlation analysis, we find that the seed and core populations are well correlated with a coefficient of approximate to 0.73 with a time lag of 10-15 h. We present evidence of a seed population threshold that is necessary for subsequent acceleration. The depth of penetration of the seed population determines the inner boundary of the acceleration process. However, we show that an enhanced seed population alone is not enough to produce acceleration in the higher energies, implying that the seed population of hundreds of keV electrons is only one of several conditions required for MeV electron radiation belt acceleration. Y1 - 2016 U6 - https://doi.org/10.1002/2016JA022652 SN - 2169-9380 SN - 2169-9402 VL - 121 SP - 7636 EP - 7646 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Ripoll, Jean-François A1 - Loridan, Vivien A1 - Cunningham, G. S. A1 - Reeves, Geoffrey D. A1 - Shprits, Yuri Y. T1 - On the time needed to reach an equilibrium structure of the radiation belts JF - Journal of geophysical research : Space physics N2 - In this study, we complement the notion of equilibrium states of the radiation belts with a discussion on the dynamics and time needed to reach equilibrium. We solve for the equilibrium states obtained using 1-D radial diffusion with recently developed hiss and chorus lifetimes at constant values of Kp = 1, 3, and 6. We find that the equilibrium states at moderately low Kp, when plotted versus L shell (L) and energy (E), display the same interesting S shape for the inner edge of the outer belt as recently observed by the Van Allen Probes. The S shape is also produced as the radiation belts dynamically evolve toward the equilibrium state when initialized to simulate the buildup after a massive dropout or to simulate loss due to outward diffusion from a saturated state. Physically, this shape, intimately linked with the slot structure, is due to the dependence of electron loss rate (originating from wave-particle interactions) on both energy and L shell. Equilibrium electron flux profiles are governed by the Biot number (tau(Diffusion)/tau(loss)), with large Biot number corresponding to low fluxes and low Biot number to large fluxes. The time it takes for the flux at a specific (L, E) to reach the value associated with the equilibrium state, starting from these different initial states, is governed by the initial state of the belts, the property of the dynamics (diffusion coefficients), and the size of the domain of computation. Its structure shows a rather complex scissor form in the (L, E) plane. The equilibrium value (phase space density or flux) is practically reachable only for selected regions in (L, E) and geomagnetic activity. Convergence to equilibrium requires hundreds of days in the inner belt for E>300 keV and moderate Kp (<= 3). It takes less time to reach equilibrium during disturbed geomagnetic conditions (Kp = 3), when the system evolves faster. Restricting our interest to the slot region, below L = 4, we find that only small regions in (L, E) space can reach the equilibrium value: E similar to [200, 300] keV for L= [3.7, 4] at Kp= 1, E similar to[0.6, 1] MeV for L = [3, 4] at Kp = 3, and E similar to 300 keV for L = [3.5, 4] at Kp = 6 assuming no new incoming electrons. Y1 - 2016 U6 - https://doi.org/10.1002/2015JA022207 SN - 2169-9380 SN - 2169-9402 VL - 121 SP - 7684 EP - 7698 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Kronberg, Elena A. A1 - Rashev, M. V. A1 - Daly, P. W. A1 - Shprits, Yuri Y. A1 - Turner, D. L. A1 - Drozdov, Alexander Y. A1 - Dobynde, M. A1 - Kellerman, Adam C. A1 - Fritz, T. A. A1 - Pierrard, V. A1 - Borremans, K. A1 - Klecker, B. A1 - Friedel, R. T1 - Contamination in electron observations of the silicon detector on board JF - Space Weather: The International Journal of Research and Applications N2 - Since more than 15 years, the Cluster mission passes through Earth's radiation belts at least once every 2 days for several hours, measuring the electron intensity at energies from 30 to 400 keV. These data have previously been considered not usable due to contamination caused by penetrating energetic particles (protons at >100 keV and electrons at >400 keV). In this study, we assess the level of distortion of energetic electron spectra from the Research with Adaptive Particle Imaging Detector (RAPID)/Imaging Electron Spectrometer (IES) detector, determining the efficiency of its shielding. We base our assessment on the analysis of experimental data and a radiation transport code (Geant4). In simulations, we use the incident particle energy distribution of the AE9/AP9 radiation belt models. We identify the Roederer L values, L⋆, and energy channels that should be used with caution: at 3≤L⋆≤4, all energy channels (40–400 keV) are contaminated by protons (≃230 to 630 keV and >600 MeV); at L⋆≃1 and 4–6, the energy channels at 95–400 keV are contaminated by high-energy electrons (>400 keV). Comparison of the data with electron and proton observations from RBSP/MagEIS indicates that the subtraction of proton fluxes at energies ≃ 230–630 keV from the IES electron data adequately removes the proton contamination. We demonstrate the usefulness of the corrected data for scientific applications. Y1 - 2016 U6 - https://doi.org/10.1002/2016SW001369 SN - 1542-7390 VL - 14 SP - 449 EP - 462 PB - American Geophysical Union CY - Washington ER - TY - THES A1 - Böhm, Verónica Julia T1 - La imperfectividad en la prensa española y su relación con las categorías semánticas de modalidad y evidencialidad T2 - Potsdam Linguistic Investigations / Potsdamer Linguistische Untersuchungen / Recherches Linguistiques à Potsdam ; 19 N2 - Este libro adopta un enfoque semántico-funcional en el estudio de la imperfectividad en el español. La imperfectividad, como categoría semántico-funcional, encuentra afinidades con otras funciones semánticas, donde el valor de verdad de una situación se presenta como indeterminado o impreciso como, por ejemplo, en la reproducción de citas y distanciamiento del hablante frente a lo dicho; de manera que la imperfectividad se solapa con la modalidad y evidencialidad. Asimismo, se analizan las funciones secundarias de la imperfectividad relacionadas con la modalidad epistémica y evidencialidad indirecta en la prensa española. En todos los casos, los textos analizados proceden de corpus reales del español (CREA, Corpus del Español y GlossaNet). Y1 - 2016 SN - 978-3-631-66776-7 PB - Lang CY - Frankfurt am Main ER - TY - JOUR A1 - Stolle, Claudia A1 - Michaelis, Ingo A1 - Rauberg, Jan T1 - The role of high-resolution geomagnetic field models for investigating ionospheric currents at low Earth orbit satellites JF - Earth, planets and space N2 - Low Earth orbiting geomagnetic satellite missions, such as the Swarm satellite mission, are the only means to monitor and investigate ionospheric currents on a global scale and to make in situ measurements of F region currents. High-precision geomagnetic satellite missions are also able to detect ionospheric currents during quiet-time geomagnetic conditions that only have few nanotesla amplitudes in the magnetic field. An efficient method to isolate the ionospheric signals from satellite magnetic field measurements has been the use of residuals between the observations and predictions from empirical geomagnetic models for other geomagnetic sources, such as the core and lithospheric field or signals from the quiet-time magnetospheric currents. This study aims at highlighting the importance of high-resolution magnetic field models that are able to predict the lithospheric field and that consider the quiet-time magnetosphere for reliably isolating signatures from ionospheric currents during geomagnetically quiet times. The effects on the detection of ionospheric currents arising from neglecting the lithospheric and magnetospheric sources are discussed on the example of four Swarm orbits during very quiet times. The respective orbits show a broad range of typical scenarios, such as strong and weak ionospheric signal (during day- and nighttime, respectively) superimposed over strong and weak lithospheric signals. If predictions from the lithosphere or magnetosphere are not properly considered, the amplitude of the ionospheric currents, such as the midlatitude Sq currents or the equatorial electrojet (EEJ), is modulated by 10-15 % in the examples shown. An analysis from several orbits above the African sector, where the lithospheric field is significant, showed that the peak value of the signatures of the EEJ is in error by 5 % in average when lithospheric contributions are not considered, which is in the range of uncertainties of present empirical models of the EEJ. KW - Geomagnetic field KW - Ionospheric current KW - Geomagnetic models Y1 - 2016 U6 - https://doi.org/10.1186/s40623-016-0494-1 SN - 1880-5981 VL - 68 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Denecke, Klaus-Dieter T1 - The partial clone of linear terms JF - Siberian Mathematical Journal N2 - Generalizing a linear expression over a vector space, we call a term of an arbitrary type tau linear if its every variable occurs only once. Instead of the usual superposition of terms and of the total many-sorted clone of all terms in the case of linear terms, we define the partial many-sorted superposition operation and the partial many-sorted clone that satisfies the superassociative law as weak identity. The extensions of linear hypersubstitutions are weak endomorphisms of this partial clone. For a variety V of one-sorted total algebras of type tau, we define the partial many-sorted linear clone of V as the partial quotient algebra of the partial many-sorted clone of all linear terms by the set of all linear identities of V. We prove then that weak identities of this clone correspond to linear hyperidentities of V. KW - linear term KW - clone KW - partial clone KW - linear hypersubstitution KW - linear identity KW - linear hyperidentity Y1 - 2016 U6 - https://doi.org/10.1134/S0037446616040030 SN - 0037-4466 SN - 1573-9260 VL - 57 SP - 589 EP - 598 PB - Pleiades Publ. CY - New York ER - TY - THES A1 - Halecker, Bastian T1 - New perspective and insights on business model innovation using systems thinking and action case studies T1 - Neue Perspektive und Einblicke in die Geschäftsmodellinnovation durch die Anwendung von System Denken und Aktionsfallstudien N2 - In recent years, entire industries and their participants have been affected by disruptive technologies, resulting in dramatic market changes and challenges to firm’s business logic and thus their business models (BMs). Firms from mature industries are increasingly realizing that BMs that worked successfully for years have become insufficient to stay on track in today’s “move fast and break things” economy. Firms must scrutinize the core logic that informs how they do business, which means exploring novel ways to engage customers and get them to pay. This can lead to a complete renewal of existing BMs or innovating completely new BMs. BMs have emerged as a popular object of research within the last decade. Despite the popularity of the BM, the theoretical and empirical foundation underlying the concept is still weak. In particular, the innovation process for BMs has been developed and implemented in firms, but understanding of the mechanisms behind it is still lacking. Business model innovation (BMI) is a complex and challenging management task that requires more than just novel ideas. Systematic studies to generate a better understanding of BMI and support incumbents with appropriate concepts to improve BMI development are in short supply. Further, there is a lack of knowledge about appropriate research practices for studying BMI and generating valid data sets in order to meet expectations in both practice and academia. This paper-based dissertation aims to contribute to research practice in the field of BM and BMI and foster better understanding of the BM concept and BMI processes in incumbent firms from mature industries. The overall dissertation presents three main results. The first result is a new perspective, or the systems thinking view, on the BM and BMI. With the systems thinking view, the fuzzy BM concept is clearly structured and a BMI framework is proposed. The second result is a new research strategy for studying BMI. After analyzing current research practice in the areas of BMs and BMI, it is obvious that there is a need for better research on BMs and BMI in terms of accuracy, transparency, and practical orientation. Thus, the action case study approach combined with abductive methodology is proposed and proven in the research setting of this thesis. The third result stems from three action case studies in incumbent firms from mature industries employed to study how BMI occurs in practice. The new insights and knowledge gained from the action case studies help to explain BMI in such industries and increase understanding of the core of these processes. By studying these issues, the articles complied in this thesis contribute conceptually and empirically to the recently consolidated but still increasing literature on the BM and BMI. The conclusions and implications made are intended to foster further research and improve managerial practices for achieving BMI in a dramatically changing business environment. N2 - In den letzten Jahren sind ganze Branchen und ihre Teilnehmer durch neue disruptive Technologien stark beeinflusst worden, was zu dramatischen Marktveränderungen und Herausforderungen für die Art und Weise wie das Geschäft des Unternehmens funktioniert, geführt hat. Firmen aus reifen Industrien erkennen zunehmend, dass die bestehenden Geschäftsmodelle, die jahrelang erfolgreich funktionierten, dem neuen Veränderungsdruck der dynamischen Wirtschaft nicht mehr genügen. Die Unternehmen müssen ihre Geschäftslogik radikal hinterfragen. Diese beschreibt, wie sie Geschäfte machen, wie sie mit dem Kunden interagieren und wie sie letztlich Geld verdienen. Dies kann zu einer kompletten Erneuerung der bestehenden Geschäftsmodelle führen oder völlig neue innovative Geschäftsmodelle hervorbringen. Geschäftsmodelle haben sich als ein beliebtes Forschungsobjekt in den letzten zehn Jahren etabliert. Trotz der Popularität des Geschäftsmodell Konzeptes sind die theoretischen und empirischen Grundlagen dahinter nach wie vor eher schwach ausgeprägt. Insbesondere besteht für den Geschäftsmodellinnovationsprozess, wie er in Unternehmen implementiert und angewendet wird, nur ein unzureichendes Verständnis. Geschäftsmodellinnovation ist eine komplexe und anspruchsvolle Managementaufgabe, die mehr als nur neue Ideen erfordert. Systematische Untersuchungen, die zu einem besseren Verständnis von Geschäftsmodellinnovation führen und damit etablierten Unternehmen mit entsprechenden Konzepte unterstützt, gibt es zu wenige. Des Weiteren gibt es ein Defizit bei geeigneten Forschungspraktiken, um Geschäftsmodellinnovationen zu untersuchen, welche sowohl den praktischen als auch wissenschaftlichen Anforderungen gerecht werden. Die vorliegende kumulative Dissertation zielt darauf ab, die Forschungspraxis im Bereich der Geschäftsmodelle und der Geschäftsmodellinnovation zu fördern und ein besseres Verständnis zum Geschäftsmodell Konzept als auch zur Geschäftsmodellinnovation in etablierten Unternehmen in reifen Industrien zu schaffen. Die Dissertation liefert dabei drei wesentliche Ergebnisse. Das erste Ergebnis ist eine neue Perspektive auf das Geschäftsmodell Konzept und die Geschäftsmodellinnovation mit Hilfe des System Denkens (Systemtheorie). Mit einer systemischen Sicht wird das bis dahin unscharfe Konzept klar strukturiert und es wird ein Rahmenwerk für Geschäftsmodellinnovation vorgeschlagen. Das zweite Ergebnis ist eine neue Forschungsstrategie für die Untersuchung von Geschäftsmodellinnovation. Nach der Analyse der gängigen Praxis der aktuellen Forschung in den Bereichen Geschäftsmodell und Geschäftsmodellinnovation, wird klar, dass die aktuelle Forschung Schwächen in Bezug auf Genauigkeit, Transparenz und Praxisorientierung aufweist. Somit wird die Aktionsfallstudie in Kombination mit der Abduktion als modernes Forschungsdesign vorgeschlagen und in dieser Arbeit angewendet. Das dritte Ergebnis ergibt sich aus drei durchgeführten Aktionsfallstudien in etablierten Unternehmen aus reifen Industrien, um das Phänomen Geschäftsmodellinnovation in der Praxis zu untersuchen. Die neuen Einsichten und Erkenntnisse, die aus den Aktionsfallstudien gewonnen wurden, helfen dabei Geschäftsmodellinnovation zu erklären und das Verständnis für den Gesamtprozess zu erhöhen. Die Arbeit liefert damit sowohl einen konkreten konzeptionellen als auch empirischen Beitrag zu der sich weiter konsolidierenden aber nach wie vor unscharfen Literatur der Geschäftsmodelle und Geschäftsmodellinnovation. Die Schlussfolgerungen und Handlungsempfehlungen zeigen einen klaren Weg für zukünftige Forschungen auf und liefern konkrete praktische Implikationen für das Management im Umgang mit den anstehenden radikalen Geschäftsmodellveränderungen. KW - business model KW - business model innovation KW - action case study KW - systems thinking KW - mature industry KW - Geschäftsmodell KW - Geschäftsmodellinnovation KW - System Denken KW - Systemtheorie KW - Aktionsfallstudie KW - Abduktion Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-90404 ER - TY - CHAP A1 - Kiy, Alexander A1 - Hafer, Jörg A1 - Schumann, Marlen A1 - Enke, Uta ED - Lucke, Ulrike ED - Schwill, Andreas ED - Zender, Raphael T1 - Digitale Teilnehmerzertifikate und Open Badges verbinden BT - Der E-Teaching-Badge T2 - DeLFI 2016 - Die 14. E-Learning Fachtagung Informatik 11.-14. September 2016 Potsdam N2 - Während Qualifikationen und Kompetenzen, die auf informellem Wege erworben werden, immer mehr Beachtung finden, stellt sowohl deren Darstellung als auch die Anerkennung ein meist unüberwindbares Hindernis für Ausstellende und Erwerbende dar. Vermehrt wird unterdessen von klassisch papiergebundenen auf digitale Teilnahmezertifikate umgestellt, um den Nachweis von Kompetenz- und Qualifikationserwerb zu vereinfachen. In diesem Zusammenhang kann die Verbindung von digitalen Teilnahmezertifikaten und Open Badges einen Mehrwert für die öffentliche Darstellung und Verifikation bieten. KW - Teilnehmerzertifikate KW - Peer-Review KW - Open Badges KW - Open Badge Infrastructure KW - OBI Y1 - 2016 UR - http://subs.emis.de/LNI/Proceedings/Proceedings262/article21.html SN - 978-3-88579-656-5 IS - P-262 SP - 285 EP - 287 PB - Gesellschaft für Informatik CY - Bonn ER - TY - JOUR A1 - Leib, Julia T1 - Shaping peace: an investigation of the mechanisms underlying post-conflict peacebuilding JF - Peace, conflict & development : an interdisciplinary journal N2 - What shapes peace, and how can peace be successfully built in those countries affected by armed conflict? This paper examines mpeacebuilding in the aftermath of civil wars in order to identify the conditions for post-conflict peace. The field of civil war research is characterised by case studies, comparative analyses and quantitative research, which relate relatively little to each other. Furthermore, the complex dynamics of peacebuilding have hardly been investigated so far. Thus, the question remains of how best to enhance the prospects of a stable peace in post-conflict societies. Therefore, it is necessary to capture the dynamics of post-conflict peace. This paper aims at helping to narrow these research gaps by 1) presenting the benefits of set theoretic methods for peace and conflict studies; 2) identifying remote conflict environment factors and proximate peacebuilding factors which have an influence on the peacebuilding process and 3) proposing a set-theoretic multi-method research approach in order to identify the causal structures and mechanisms underlying the complex realm of post-conflict peacebuilding. By implementing this transparent and systematic comparative approach, it will become possible to discover the dynamics of post-conflict peace. KW - civil war KW - peacebuilding KW - post-conflict peace KW - set theory KW - QCA Y1 - 2016 SN - 1742-0601 IS - 22 SP - 25 EP - 76 PB - Univ. CY - Bradford ER - TY - JOUR A1 - Abseher, Michael A1 - Musliu, Nysret A1 - Woltran, Stefan A1 - Gebser, Martin A1 - Schaub, Torsten H. T1 - Shift Design with Answer Set Programming JF - Fundamenta informaticae N2 - Answer Set Programming (ASP) is a powerful declarative programming paradigm that has been successfully applied to many different domains. Recently, ASP has also proved successful for hard optimization problems like course timetabling and travel allotment. In this paper, we approach another important task, namely, the shift design problem, aiming at an alignment of a minimum number of shifts in order to meet required numbers of employees (which typically vary for different time periods) in such a way that over- and understaffing is minimized. We provide an ASP encoding of the shift design problem, which, to the best of our knowledge, has not been addressed by ASP yet. Our experimental results demonstrate that ASP is capable of improving the best known solutions to some benchmark problems. Other instances remain challenging and make the shift design problem an interesting benchmark for ASP-based optimization methods. Y1 - 2016 U6 - https://doi.org/10.3233/FI-2016-1396 SN - 0169-2968 SN - 1875-8681 VL - 147 SP - 1 EP - 25 PB - IOS Press CY - Amsterdam ER - TY - THES A1 - Herenz, Edmund Christian T1 - Detecting and understanding extragalactic Lyman α emission using 3D spectroscopy T1 - Detektion und Interpretation extragalaktischer Lyman Alpha Emission mittels 3D Spektroskopie N2 - In this thesis we use integral-field spectroscopy to detect and understand of Lyman α (Lyα) emission from high-redshift galaxies. Intrinsically the Lyα emission at λ = 1216 Å is the strongest recombination line from galaxies. It arises from the 2p → 1s transition in hydrogen. In star-forming galaxies the line is powered by ionisation of the interstellar gas by hot O- and B- stars. Galaxies with star-formation rates of 1 - 10 Msol/year are expected to have Lyα luminosities of 42 dex - 43 dex (erg/s), corresponding to fluxes ~ -17 dex - -18 dex (erg/s/cm²) at redshifts z~3, where Lyα is easily accessible with ground-based telescopes. However, star-forming galaxies do not show these expected Lyα fluxes. Primarily this is a consequence of the high-absorption cross-section of neutral hydrogen for Lyα photons σ ~ -14 dex (cm²). Therefore, in typical interstellar environments Lyα photons have to undergo a complex radiative transfer. The exact conditions under which Lyα photons can escape a galaxy are poorly understood. Here we present results from three observational projects. In Chapter 2, we show integral field spectroscopic observations of 14 nearby star-forming galaxies in Balmer α radiation (Hα, λ = 6562.8 Å). These observations were obtained with the Potsdam Multi Aperture Spectrophotometer at the Calar-Alto 3.5m Telescope}. Hα directly traces the intrinsic Lyα radiation field. We present Hα velocity fields and velocity dispersion maps spatially registered onto Hubble Space Telescope Lyα and Hα images. From our observations, we conjecture a causal connection between spatially resolved Hα kinematics and Lyα photometry for individual galaxies. Statistically, we find that dispersion-dominated galaxies are more likely to emit Lyα photons than galaxies where ordered gas-motions dominate. This result indicates that turbulence in actively star-forming systems favours an escape of Lyα radiation. Not only massive stars can power Lyα radiation, but also non-thermal emission from an accreting super-massive black hole in the galaxy centre. If a galaxy harbours such an active galactic nucleus, the rate of hydrogen-ionising photons can be more than 1000 times higher than that of a typical star-forming galaxy. This radiation can potentially ionise large regions well outside the main stellar body of galaxies. Therefore, it is expected that the neutral hydrogen from these circum-galactic regions shines fluorescently in Lyα. Circum-galactic gas plays a crucial role in galaxy formation. It may act as a reservoir for fuelling star formation, and it is also subject to feedback processes that expel galactic material. If Lyα emission from this circum-galactic medium (CGM) was detected, these important processes could be studied in-situ around high-z galaxies. In Chapter 3, we show observations of five radio-quiet quasars with PMAS to search for possible extended CGM emission in the Lyα line. However, in four of the five objects, we find no significant traces of this emission. In the fifth object, there is evidence for a weak and spatially quite compact Lyα excess at several kpc outside the nucleus. The faintness of these structures is consistent with the idea that radio-quiet quasars typically reside in dark matter haloes of modest masses. While we were not able to detect Lyα CGM emission, our upper limits provide constraints for the new generation of IFS instruments at 8--10m class telescopes. The Multi Unit Spectroscopic Explorer (MUSE) at ESOs Very Large Telescopeis such an unique instrument. One of the main motivating drivers in its construction was the use as a survey instrument for Lyα emitting galaxies at high-z. Currently, we are conducting such a survey that will cover a total area of ~100 square arcminutes with 1 hour exposures for each 1 square arcminute MUSE pointing. As a first result from this survey we present in Chapter 5 a catalogue of 831 emission-line selected galaxies from a 22.2 square arcminute region in the Chandra Deep Field South. In order to construct the catalogue, we developed and implemented a novel source detection algorithm -- LSDCat -- based on matched filtering for line emission in 3D spectroscopic datasets (Chapter 4). Our catalogue contains 237 Lyα emitting galaxies in the redshift range 3 ≲ z ≲ 6. Only four of those previously had spectroscopic redshifts in the literature. We conclude this thesis with an outlook on the construction of a Lyα luminosity function based on this unique sample (Chapter 6). N2 - In der vorliegenden Doktorarbeit präsentieren wir Resultate aus drei integralfeldspektroskopischen Beobachtungskampagnen die mit der Intention Lyman α (Lyα) Strahlung von hoch-rotverschobenen Galaxien zu detektieren und zu verstehen durchgeführt wurden. Die Lyα Emissionslinie im ultravioletten Teil des elektromagnetischen Spektrums (λ = 1216 Å) ist intrinsisch die stärkste Rekombinationslinie im Linienspektrum sternbildender Galaxien. Die Linie ist eine Folge der Ionisation des interstellaren Gases durch heiße O- und B- Sterne. Man erwartet von Galaxien mit Sternentstehungsraten 1 - 10 Msol/Jahr intrinsische Lyα Leuchtkräfte von 42 dex - 43 dex (erg/s), was bei Rotverschiebungen von z~3, bei denen Lyα mit bodengebundenen Teleskopen zu beobachten ist, einem Strahlungsstrom von ~ -17 dex - -18 dex (erg/s/cm²) entspricht. Allerdings werden nicht von allen sternbildenen Galaxien derartige Lyα Strahlungsströme gemessen. Dies ist in erster Linie eine direkte Konsequenz des hohen Absorptionsquerschnitts von neutralem Wasserstoff für Lyα Photonen. Deshalb erfahren Lyα Photonen einen komplexen Strahlungstransportprozess in typischen interstellaren Umgebungen. Die exakten Bedingungen bei denen Lyα Strahlung eine Galaxie verlassen sind noch nicht hinreichend gut verstanden. Diesbezüglich werden in Kapitel 2 dieser Arbeit integralfeldspektroskopische Beobachtungsergebnisse der Balmer α Strahlung (Hα, λ = 6562.8 Å) von 14 nahen sternbildenden Galaxien gezeigt. Die Beobachtungsdaten wurden mit dem Potsdam Multi Aperture Spectrophotometer (PMAS) am Calar Alto 3.5m Teleskop gewonnen. Hα Strahlung ist eine direkte Kopie des intrinischen Lyα Strahlungsfeldes der Galaxien. Wir zeigen unsere Hα Geschwindigkeitsfelder und Geschwindigkeitsdispersionsfelder räumlich überlagert zu Hubble-Weltraumteleskop-Bildaufnahmen der Lyα und Hα Strahlungsströme. Aus diesen Beobachtungen können wir schlussfolgern, dass in einigen Galaxien kausale Zusammenhänge zwischen der Hα-Kinematik und der Lyα-Photometrie bestehen. Statistisch signifikant finden wir, dass Galaxien, bei denen chaotische Dispersionsbewegungen dominieren, wahrscheinlicher Lyα Strahlung abgeben als Galaxien bei denen die Gasbewegungen durch geordnete Bewegungen dominiert sind. Dieses Resultat ist ein Indiz dafür, dass Turbulenz im interstellaren Medium aktiv sternbildender Galaxien schafft, welche ein Austreten der Lyα-Strahlung begünstigen. Neben massereichen Sternen kann nicht-thermische Strahlung eines akretierenden supermassereichen schwarzen Loches eine weitere Energiequelle zur Erzeugung von Lyα Strahlung sein. Wenn eine Galaxie einen solchen aktiven Galaxienkern enthält, kann die Rate der ionisierenden Photonen 1000-mal höher sein als bei einer normalen sternbildenden Galaxie. Diese Strahlung hat das Potential große Bereiche weit ausserhalb der Sternansammlungen der Galaxien zu ionisieren. Deshalb ist zu erwarten, dass der neutrale Wasserstoff in diesen zirkum-galaktischen Gebieten in Lyα-Strahlung fluoresziert. Dieses zirkum-galaktische Gas spielt eine wesentliche Rolle bei der Entwicklung von Galaxien. Zum Einen ist es das Reservoir aus denen Sternentstehungsprozesse ihr Gas beziehen, zum Anderen ist es Wechselwirkungsprozessen ausgesetzt, bei denen Gas aus der Galaxie hinausgeschleudert wird. Wenn Lyα-Strahlung dieses zirkum-galaktischen Mediums detektiert werden könnte, ließen sich diese fundamentalen Prozesse der Galaxienentwicklung detaillierter studieren. In Kapitel 3 dieser Arbeit zeigen wir PMAS Beobachtungsdaten von 5 radio-leisen Quasaren in denen wir nach dieser ausgedehnten Lyα-Strahlung gesucht haben. Jedoch haben wir für 4 unserer Quasare keine signifikanten Spuren dieser ausgedehnten Strahlung entdecken können. Im fünften Objekt finden wir in Entfernung von einigen Kiloparsec zum Kern Anzeichen für eine schwache und räumlich eher kompakte Quelle. Deartig schwache Flüsse von solchen Strukturen erscheinen konsistent mit der Annahme, dass radio-leise Quasare sich in Halos aus dunkler Materie mit eher moderaten Massen befinden. Obwohl wir nicht direkt Lyα-Strahlung vom zirkum-galaktischen Medium detektieren konnten, sind unsere Detektionsgrenzen von Nutzem bei der Planung von diesbezüglichen Beobachtungen mit der neuen Generation von Integralfeldspektrographen an 8--10m Teleskopen. Ein derartiges Instrument ist der Multi Unit Spectroscopic Explorer (MUSE) am ESO Very Large Telescope. Einer der Hauptbeweggründe für dessen Konstruktion war die Verwendung als Durchmusterungsinstrument für Lyα emittierende Galaxien bei hohen Rotverschiebungen. Aktuell führen wir eine derartige Durchmusterungskampagne durch. Nach deren Abschluss, werden wir eine Fläche von 100 Quadratbogenminuten durchmustert haben. In Kapitel 5 dieser Arbeit präsentieren wir als erstes Resultat einen Katalog von 831 Emissionslinienselektierten Galaxien in einer 22.2 Quadratbogenminuten großen Region im Chandra Deep Field South. Um diesen Katalog zu erzeugen, haben wir eine neuartige Quellendetektionsmethode für integralfeldspektroskopische Datensätze entwickelt und implementiert (Kapitel 4). Unser Katalog enthält 237 Lyα emittierende Galaxien bei Rotverschiebungen 3 ≲ z ≲ 6. Aufgrund ihrer geringen Kontinuumsflussdichten existierten zuvor nur von 4 dieser Galaxien spektroskopische Rotverschiebungen. Als Abschluss dieser Arbeit präsentieren wir einen Ausbick bezüglich der Konstruktion einer Leuchtkraftfunktion dieser einzigartigen Lyα Galaxienstichprobe (Kapitel 6). KW - astrophysics KW - galaxies KW - high redshift galaxies KW - integral field spectroscopy KW - quasars KW - Astrophysik KW - Galaxien KW - Galaxien bei hoher Rotverschiebung KW - Integralfeldspektroskopie KW - Quasare Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-102341 ER - TY - JOUR A1 - Vorburger, Thomas A1 - Nedielkov, Ruslan A1 - Brosig, Alexander A1 - Bok, Eva A1 - Schunke, Emina A1 - Steffen, Wojtek A1 - Mayer, Sonja A1 - Goetz, Friedrich A1 - Möller, Heiko Michael A1 - Steuber, Julia T1 - Role of the Na+-translocating NADH:quinone oxidoreductase in voltage generation and Na+ extrusion in Vibrio cholerae JF - Biochimica et biophysica acta : Bioenergetics N2 - For Vibrio cholerae, the coordinated import and export of Na+ is crucial for adaptation to habitats with different osmolarities. We investigated the Na+-extruding branch of the sodium cycle in this human pathogen by in vivo Na-23-NMR spectroscopy. The Na+ extrusion activity of cells was monitored after adding glucose which stimulated respiration via the Na+-translocating NADH:quinone oxidoreductase (Na+-NQR). In a V. cholerae deletion mutant devoid of the Na+-NQR encoding genes (nqrA-F), rates of respiratory Na+ extrusion were decreased by a factor of four, but the cytoplasmic Na+ concentration was essentially unchanged. Furthermore, the mutant was impaired in formation of transmembrane voltage (Delta psi, inside negative) and did not grow under hypoosmotic conditions at pH 8.2 or above. This growth defect could be complemented by transformation with the plasmid encoded nqr operon. In an alkaline environment, Na+/H+ antiporters acidify the cytoplasm at the expense of the transmembrane voltage. It is proposed that, at alkaline pH and limiting Na+ concentrations, the Na+-NQR is crucial for generation of a transmembrane voltage to drive the import of H+ by electrogenic Na+/H+ antiporters. Our study provides the basis to understand the role of the Na+-NQR in pathogenicity of V. cholerae and other pathogens relying on this primary Na+ pump for respiration. (C) 2015 Elsevier B.V. All rights reserved. KW - Nuclear magnetic resonance (NMR) KW - Sodium transport KW - Vibrio cholerae KW - Respiration KW - Na+ homeostasis KW - Hypoosmotic stress Y1 - 2016 U6 - https://doi.org/10.1016/j.bbabio.2015.12.010 SN - 0005-2728 SN - 0006-3002 VL - 1857 SP - 473 EP - 482 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Kistner, Saskia A1 - Vollmeyer, Regina A1 - Burns, Bruce D. A1 - Kortenkamp, Ulrich T1 - Model development in scientific discovery learning with a computer-based physics task JF - Computers in human behavior N2 - Based on theories of scientific discovery learning (SDL) and conceptual change, this study explores students' preconceptions in the domain of torques in physics and the development of these conceptions while learning with a computer-based SDL task. As a framework we used a three-space theory of SDL and focused on model space, which is supposed to contain the current conceptualization/model of the learning domain, and on its change through hypothesis testing and experimenting. Three questions were addressed: (1) What are students' preconceptions of torques before learning about this domain? To do this a multiple-choice test for assessing students' models of torques was developed and given to secondary school students (N = 47) who learned about torques using computer simulations. (2) How do students' models of torques develop during SDL? Working with simulations led to replacement of some misconceptions with physically correct conceptions. (3) Are there differential patterns of model development and if so, how do they relate to students’ use of the simulations? By analyzing individual differences in model development, we found that an intensive use of the simulations was associated with the acquisition of correct conceptions. Thus, the three-space theory provided a useful framework for understanding conceptual change in SDL. KW - Scientific discovery learning KW - Multiple problem spaces KW - Computer simulations KW - Physics concepts KW - Misconceptions KW - Conceptual change Y1 - 2016 U6 - https://doi.org/10.1016/j.chb.2016.02.041 SN - 0747-5632 SN - 1873-7692 VL - 59 SP - 446 EP - 455 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Sinclair, Nathalie A1 - Bussi, Maria G. Bartolini A1 - de Villiers, Michael A1 - Jones, Keith A1 - Kortenkamp, Ulrich A1 - Leung, Allen A1 - Owens, Kay T1 - Recent research on geometry education: an ICME-13 survey team report JF - ZDM : The International Journal on Mathematics Education N2 - This survey on the theme of Geometry Education (including new technologies) focuses chiefly on the time span since 2008. Based on our review of the research literature published during this time span (in refereed journal articles, conference proceedings and edited books), we have jointly identified seven major threads of contributions that span from the early years of learning (pre-school and primary school) through to post-compulsory education and to the issue of mathematics teacher education for geometry. These threads are as follows: developments and trends in the use of theories; advances in the understanding of visuo spatial reasoning; the use and role of diagrams and gestures; advances in the understanding of the role of digital technologies; advances in the understanding of the teaching and learning of definitions; advances in the understanding of the teaching and learning of the proving process; and, moving beyond traditional Euclidean approaches. Within each theme, we identify relevant research and also offer commentary on future directions. KW - Geometry KW - Technology KW - Diagrams KW - Definitions KW - Gestures KW - Proving KW - Digital technology KW - Visuospatial reasoning Y1 - 2016 U6 - https://doi.org/10.1007/s11858-016-0796-6 SN - 1863-9690 SN - 1863-9704 VL - 48 SP - 691 EP - 719 PB - Springer CY - Heidelberg ER -