TY - GEN A1 - Rodriguez-Sillke, Yasmina A1 - Steinhoff, U. A1 - Bojarski, Christian A1 - Lissner, Donata A1 - Schumann, Michael A1 - Branchi, F. A1 - Siegmund, Britta A1 - Glauben, Rainer T1 - Deep immune profiling of human Peyer´s Patches in patients of inflammatory bowel diseases T2 - European journal of immunology Y1 - 2019 U6 - https://doi.org/10.1002/eji.201970300 SN - 0014-2980 SN - 1521-4141 VL - 49 SP - 203 EP - 204 PB - Wiley CY - Weinheim ER - TY - THES A1 - Siegmund, Michael T1 - General Douglas MacArthur und der Koreakrieg T1 - General Douglas MacArthur and the Korean War N2 - Zu Beginn des Koreakrieges hatte im benachbarten Japan ein Mann de facto alle Macht in seinen Händen, der seit 1942 Oberbefehlshaber der alliierten Truppen im Pazifik gewesen war und am 2. September 1945 mit der Entgegennahme der japanischen Kapitulation den Zweiten Weltkrieg beendete – Douglas MacArthur. Der General, der den Pazifik einst als angelsächsischen See bezeichnet hatte, war unter seiner administrativen Leitung maßgeblich verantwortlich für die japanische Nachkriegsentwicklung und stand nun vor der neuen Herausforderung des Oberbefehls über die Truppen der Vereinten Nationen in Korea. Der über alle Maßen erfolgsverwöhnte MacArthur hatte die an Profilierungsmöglichkeiten nicht zu überbietenden Weltkriege genutzt, um zu einem der höchstdekorierten Offiziere der US-Militärgeschichte aufzusteigen. Innerhalb seines pazifischen Machtbereiches hatte er sich über die Jahre den Status eines quasi souveränen Staatsoberhauptes aufgebaut – mit einem eigenen Verwaltungsapparat, einer eigenen Armee und einem eigenen Geheimdienst, und er betrieb, einem souveränen Herrscher entsprechend, auch seine ganz eigene Politik. In dieser Arbeit wird, ausgehend von der These – MacArthur habe, einen Plan verfolgend, seine Position genutzt, um den Versuch zu unternehmen, den für ihn sehr gelegen und keineswegs überraschend kommenden Krieg in Korea zu einem Entscheidungsschlag gegen den asiatischen Kommunismus auszuweiten, nationalistischen Kräften zur Macht zu verhelfen und den dann endlich nicht mehr zu übertreffenden militärischen Ruhm politisch zu instrumentalisieren, um zur republikanischen Präsidentschaftskandidatur zu gelangen – zunächst das Hauptaugenmerk auf MacArthurs Beziehung zu Mao Tse-tungs Gegenspieler Chiang Kai-shek, dem Machthaber im Süden Koreas, Syngman Rhee, und deren mögliche strategische Einbeziehung sowie zur demokratischen Truman-Administration gelegt. Im zweiten Schwerpunkt werden, beginnend mit dem kurzen Entwurf eines Persönlichkeitsprofils MacArthurs, seine militärischen und politischen Ziele plausibilisiert. Dabei dient die weiter oben formulierte These als Blaupause für die Betrachtung des Kriegsverlaufes mit einem agierenden, aktiv seinen Plan verfolgenden General MacArthur, dessen (politisches) Handeln auch nach seiner Absetzung durch Präsident Truman noch unter dem Licht dieses Plans betrachtet werden kann. KW - Koreakrieg KW - MacArthur KW - Korea KW - Truman KW - Kalter Krieg KW - Korean War KW - MacArthur KW - Korea KW - Truman KW - Cold War Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-67378 ER - TY - JOUR A1 - Perscheid, Michael A1 - Siegmund, Benjamin A1 - Taeumel, Marcel A1 - Hirschfeld, Robert T1 - Studying the advancement in debugging practice of professional software developers JF - Software Quality Journal N2 - In 1997, Henry Lieberman stated that debugging is the dirty little secret of computer science. Since then, several promising debugging technologies have been developed such as back-in-time debuggers and automatic fault localization methods. However, the last study about the state-of-the-art in debugging is still more than 15 years old and so it is not clear whether these new approaches have been applied in practice or not. For that reason, we investigate the current state of debugging in a comprehensive study. First, we review the available literature and learn about current approaches and study results. Second, we observe several professional developers while debugging and interview them about their experiences. Third, we create a questionnaire that serves as the basis for a larger online debugging survey. Based on these results, we present new insights into debugging practice that help to suggest new directions for future research. KW - Debugging KW - Literature review KW - Field study KW - Online survey Y1 - 2016 U6 - https://doi.org/10.1007/s11219-015-9294-2 SN - 0963-9314 SN - 1573-1367 VL - 25 SP - 83 EP - 110 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Briest, Franziska A1 - Grass, Irina A1 - Sedding, Dagmar A1 - Moebs, Markus A1 - Christen, Friederike A1 - Benecke, Joana A1 - Fuchs, Karolin A1 - Mende, Stefanie A1 - Kaemmerer, Daniel A1 - Sänger, Jörg A1 - Kunze, Almut A1 - Geisler, Christina A1 - Freitag, Helma A1 - Lewens, Florentine A1 - Worpenberg, Lina A1 - Iwaszkiewicz, Sara A1 - Siegmund, Britta A1 - Walther, Wolfgang A1 - Hummel, Michael A1 - Grabowski, Patricia T1 - Mechanisms of Targeting the MDM2-p53-FOXM1 Axis in Well-Differentiated Intestinal Neuroendocrine Tumors JF - Neuroendocrinology : international journal for basic and clinical studies on neuroendocrine relationships N2 - Background/Aims: The tumor suppressor p53 is rarely mutated in gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN) but they frequently show a strong expression of negative regulators of p53, rendering these tumors excellent targets for a p53 recovery therapy. Therefore, we analyzed the mechanisms of a p53 recovery therapy on intestinal neuroendocrine tumors in vitro and in vivo. Methods: By Western blot and immunohistochemistry, we found that in GEP-NEN biopsy material overexpression of MDM2 was present in intestinal NEN. Therefore, we analyzed the effect of a small-molecule inhibitor, nutlin-3a, in p53 wild-type and mutant GEP-NEN cell lines by proliferation assay, flow cytometry, immunofluorescence, Western blot, and by multiplex gene expression analysis. Finally, we analyzed the antitumor effect of nutlin-3a in a xenograft mouse model in vivo. During the study, the tumor volume was determined. Results: The midgut wild-type cell line KRJ-I responded to the treatment with cell cycle arrest and apoptosis. By gene expression analysis, we could demonstrate that nutlins reactivated an antiproliferative p53 response. KRJ-I-derived xenograft tumors showed a significantly decreased tumor growth upon treatment with nutlin-3a in vivo. Furthermore, our data suggest that MDM2 also influences the expression of the oncogene FOXM1 in a p53-independent manner. Subsequently, a combined treatment of nutlin-3a and cisplatin (as chemoresistance model) resulted in synergistically enhanced antiproliferative effects. Conclusion: In summary, MDM2 overexpression is a frequent event in p53 wild-type intestinal neuroendocrine neoplasms and therefore recovery of a p53 response might be a novel personalized treatment approach in these tumors. (c) 2017 S. Karger AG, Basel KW - Neuroendocrine tumors KW - Signaling KW - MDM2 KW - p53 KW - FOXM1 KW - Targeted therapy Y1 - 2017 U6 - https://doi.org/10.1159/000481506 SN - 0028-3835 SN - 1423-0194 VL - 107 IS - 1 SP - 1 EP - 23 PB - Karger CY - Basel ER - TY - GEN A1 - Rodríguez Sillke, Yasmina A1 - Schumann, Michael A1 - Lissner, Donata A1 - Branchi, Frederica A1 - Glauben, Rainer A1 - Siegmund, Britta T1 - Small intestinal inflammation but not colitis drives pro-inflammatory nutritional antigen-specific T-cell response T2 - Journal of Crohn's and Colitis N2 - Background: Inflammatory bowel disease (IBD) represents a dysregulation of the mucosal immune system. The pathogenesis of Crohn’s disease (CD) and ulcerative colitis (UC) is linked to the loss of intestinal tolerance and barrier function. The healthy mucosal immune system has previously been shown to be inert against food antigens. Since the small intestine is the main contact surface for antigens and therefore the immunological response, the present study served to analyse food-antigen-specific T cells in the peripheral blood of IBD patients. Methods: Peripheral blood mononuclear cells of CD, with an affected small intestine, and UC (colitis) patients, either active or in remission, were stimulated with the following food antigens: gluten, soybean, peanut and ovalbumin. Healthy controls and celiac disease patients were included as controls. Antigen-activated CD4+ T cells in the peripheral blood were analysed by a magnetic enrichment of CD154+ effector T cells and a cytometric antigen-reactive T-cell analysis (‘ARTE’ technology) followed by characterisation of the ef- fector response. Results: The effector T-cell response of antigen-specific T cells were compared between CD with small intestinal inflammation and UC where inflammation was restricted to the colon. Among all tested food antigens, the highest frequency of antigen-specific T cells (CD4+CD154+) was found for gluten. Celiac disease patients were included as control, since gluten has been identified as the disease- causing antigen. The highest frequency of gluten antigen-specific T cells was revealed in active CD when compared with UC, celiac disease on a gluten-free diet (GFD) and healthy controls. Ovalbuminspecific T cells were almost undetectable, whereas the reaction to soybean and peanut was slightly higher. But again, the strong- est reaction was observed in CD with small intestinal involvement compared with UC. Remarkably, in celiac disease on a GFD only antigen-specific cells for gluten were detected. These gluten-specific T cells were characterised by up-regulation of the pro-inflammatory cytokines IFN-γ, IL-17A and TNF-α. IFN-g was exclusively elevated in CD patients with active disease. Gluten-specific T-cells expressing IL-17A were increased in all IBD patients. Furthermore, T cells of CD patients, independent of disease activity, revealed a high expression of the pro-inflammatory cytokine TNF-α. Conclusion: The ‘ARTE’-technique allows to analyse and quantify food antigen specific T cells in the peripheral blood of IBD patients indicating a potential therapeutic insight. These data provide evidence that small intestinal inflammation in CD is key for the development of a systemic pro-inflammatory effector T-cell response driven by food antigens. Y1 - 2020 U6 - https://doi.org/10.1093/ecco-jcc/jjz203.172 SN - 1873-9946 SN - 1876-4479 VL - 14 SP - S154 EP - S155 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Siegmund, Nicole A1 - Panebianco, Juan E. A1 - Avecilla, Fernando A1 - Iturri, Laura Antonela A1 - Sommer, Michael A1 - Buschiazzo, Daniel A1 - Funk, Roger T1 - From gustiness to dustiness BT - the impact of wind gusts on particulate matter emissions in field experiments in La Pampa, Argentina JF - Atmosphere N2 - This study delivers the first empirical data-driven analysis of the impact of turbulence induced gustiness on the fine dust emissions from a measuring field. For quantification of the gust impact, a new measure, the Gust uptake Efficiency (GuE) is introduced. GuE provides a percentage of over- or under-proportional dust uptake due to gust activity during a wind event. For the three analyzed wind events, GuE values of up to 150% could be found, yet they significantly differed per particle size class with a tendency for lower values for smaller particles. In addition, a high-resolution correlation analysis among 31 particle size classes and wind speed was conducted; it revealed strong negative correlation coefficients for very small particles and positive correlations for bigger particles, where 5 mu m appears to be an empirical threshold dividing both directions. We conclude with a number of suggestions for further investigations: an optimized field experiment setup, a new particle size ratio (PM1/PM0.5 in addition to PM10/PM2.5), as well as a comprehensive data-driven search for an optimal wind gust definition in terms of soil erosivity. KW - wind gusts KW - wind erosion KW - particle uptake KW - dust plumes Y1 - 2022 U6 - https://doi.org/10.3390/atmos13081173 SN - 2073-4433 VL - 13 IS - 8 PB - MDPI CY - Basel ER - TY - JOUR A1 - Siegmund, Nicole A1 - Funk, Roger A1 - Koszinsky, Sylvia A1 - Buschiazzo, Daniel A1 - Sommer, Michael T1 - Effects of low-scale landscape structures on aeolian transport processes on arable land JF - Aeolian Research N2 - The landscape of the semiarid Pampa in central Argentina is characterized by late Pleistocene aeolian deposits, covering large plains with sporadic dune structures. Since the current land use changed from extensive livestock production within the Caldenal forest ecosystem to arable land, the wind erosion risk increased distinctly. We measured wind erosion and deposition patterns at the plot scale and investigated the spatial variability of the erosion processes. The wind-induced mass-transport was measured with 18 Modified Wilson and Cooke samplers (MWAC), installed on a 1.44 ha large field in a 20 x 40 m grid. Physical and chemical soil properties from the upper soil as well as a digital elevation model were recorded in a 20 x 20 m grid. In a 5-month measuring campaign data from seven storms with three different wind directions was obtained. Results show very heterogeneous patterns of erosion and deposition for each storm and indicate favoured erosion on windward and deposits on leeward terrain positions. Furthermore, a multiple regression model was build, explaining up to 70% of the spatial variance of erosion by just using four predictors: topsoil thickness, relative elevation, soil organic carbon content and slope direction. Our findings suggest a structure-process-structure complex where the landscape structure determines the effects of recent wind erosion processes which again slowly influence the structure, leading to a gradual increase of soil heterogeneity. KW - Argentina KW - La Pampa KW - Wind erosion KW - Deposition KW - Topography KW - Mass transport KW - MWAC KW - Multiple regression Y1 - 2018 U6 - https://doi.org/10.1016/j.aeolia.2018.03.003 SN - 1875-9637 SN - 2212-1684 VL - 32 SP - 181 EP - 191 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Funk, Roger A1 - Busse, Jaqueline A1 - Siegmund, Nicole A1 - Sommer, Michael A1 - Iturri, Laura Antonela A1 - Panebianco, Juan E. A1 - Avecilla, Fernando A1 - Buschiazzo, Daniel T1 - Phytoliths in particulate matter released by wind erosion on arable land in La Pampa, Argentina JF - Frontiers in environmental science N2 - Silicon (Si) is considered a beneficial element in plant nutrition, but its importance on ecosystems goes far beyond that. Various forms of silicon are found in soils, of which the phytogenic pool plays a decisive role due to its good availability. This Si returns to the soil through the decomposition of plant residues, where they then participate in the further cycle as biogenic amorphous silica (bASi) or so-called phytoliths. These have a high affinity for water, so that the water holding capacity and water availability of soils can be increased even by small amounts of ASi. Agricultural land is a considerable global dust source, and dust samples from arable land have shown in cloud formation experiments a several times higher ice nucleation activity than pure mineral dust. Here, particle sizes in the particulate matter fractions (PM) are important, which can travel long distances and reach high altitudes in the atmosphere. Based on this, the research question was whether phytoliths could be detected in PM samples from wind erosion events, what are the main particle sizes of phytoliths and whether an initial quantification was possible.Measurements of PM concentrations were carried out at a wind erosion measuring field in the province La Pampa, Argentina. PM were sampled during five erosion events with Environmental Dust Monitors (EDM). After counting and classifying all particles with diameters between 0.3 and 32 mu m in the EDMs, they are collected on filters. The filters were analyzed by Scanning Electron Microscopy and Energy Dispersive X-Ray analysis (SEM-EDX) to investigate single or ensembles of particles regarding composition and possible origins.The analyses showed up to 8.3 per cent being phytoliths in the emitted dust and up to 25 per cent of organic origin. Particles of organic origin are mostly in the coarse dust fraction, whereas phytoliths are predominately transported in the finer dust fractions. Since phytoliths are both an important source of Si as a plant nutrient and are also involved in soil C fixation, their losses from arable land via dust emissions should be considered and its specific influence on atmospheric processes should be studied in detail in the future. KW - dust KW - dust composition KW - particulate matter KW - scanning electron microscope KW - (SEM) analysis KW - phytolith Y1 - 2022 U6 - https://doi.org/10.3389/fenvs.2022.969898 SN - 2296-665X VL - 10 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Siegmund, Nicole A1 - Funk, Roger A1 - Sommer, Michael A1 - Avecilla, Fernando A1 - Esteban Panebianco, Juan A1 - Iturri, Laura Antonela A1 - Buschiazzo, Daniel T1 - Horizontal and vertical fluxes of particulate matter during wind erosion on arable land in the province La Pampa, Argentina JF - International journal of sediment research N2 - A detailed analysis of horizontal and vertical particulate matter (PM) fluxes during wind erosion has been done, based on measurements of PM smaller than 10, 2.5, and 1.0 mu mm, at windward and leeward positions on a measuring field. The three fractions of PM measurement are differently influenced by the increasing wind and shear velocities of the wind. The measured concentrations of the coarser fractions of the fine dust, PM10, and PM2.5, increase with wind and shear velocity, whereas the PM1.0 concentrations show no clear correlation to the shear velocity. The share of PM2.5 on PM10 depends on the measurement height and wind speed and varies between 4 and 12 m/s at the 1 m height ranging from 25% to 7% (average 10%), and at the 4 m height from 39% to 23% (average 30%). Although general relationships between wind speed, PM concentration, and horizontal and vertical fluxes could be found, the contribution of the measuring field was very low, as balances of incoming and outgoing fluxes show. Consequently, the measured PM concentrations are determined from a variety of sources, such as traffic on unpaved roads, cattle drives, tillage operations, and wind erosion, and thus, represent all components of land use and landscape structure in the near and far surroundings of the measuring field. The current results may reflect factors from the landscape scale rather than the influence of field-related variables. The measuring devices used to monitor PM concentrations showed differences of up to 20%, which led to considerable deviations when determining total balances. Differences up to 67% between the calculated fluxes prove the necessity of a previous calibration of the devices used. (c) 2022 International Research and Training Centre on Erosion and Sedimentation/the World Association for Sedimentation and Erosion Research. KW - PM10, PM2.5 and PM1.0 concentrations KW - Field measurements KW - Horizontal KW - flux KW - Vertical flux KW - PM balances Y1 - 2022 U6 - https://doi.org/10.1016/j.ijsrc.2022.01.004 SN - 1001-6279 SN - 2589-7284 VL - 37 IS - 5 SP - 539 EP - 552 PB - IRTCES CY - Beijing ER -