Studying large-scale structures and polarization of the Northern sky facilitating single-station data of the Low Frequency Array (LOFAR)

All-sky surveys help to gather a deep knowledge about the nature of large-scale structures in the Universe, the Milky Way and extragalactic galaxies. In the context of that, observations in the radio domain are important, as they provide information which cannot be archived from any other observing frequency. This thesis will present a new northern sky survey at radio frequencies below 200 MHz, made with one of the new generation of radio telescopes the Low Frequency Array (LOFAR; van Haarlem et al., 2013). Using data of a single station of this array a novel approach has developed to produce a northern sky survey. The necessary steps are described on how to generate a scientific usable sky map from the raw voltages. The scientific analysis of these maps will be discussed and used for further studies. An overview of the general properties of the LOFAR array will be given in Chapter 2. In this array a single station will have a physical diameter of around 60 m and therefore it allows to study large-scale emission in the northern sky at 30 to 240 MHz. Even more, with its wide frequency range and the ability to observe in polarization, LOFAR allows polarization studies at frequencies below 240 MHz. In this way it is an important instrument to study the Milky Way at low frequencies. In case of Galactic and extra-galactic emission this was never possible before. Unfortunately with existing LOFAR software it was not possible to perform all-sky imaging with a frequency resolution better than 200 kHz. Due to physical limitation, in particular the strong Faraday Rotation at low frequencies, this spectral resolution is not sufficient enough. To solve this problem, this thesis will present a way how to use raw voltages from the Transient Buffer Boards (TBBs) for all-sky imaging at sufficiently high frequency resolution. In particular for all necessary steps new software tools and algorithm had to be developed. The correlation of the data will be described in Chapter 3, as well as all the technical challenges of the further data reduction. This includes the data inspection, the calibration and dealing with the antenna pattern and ionospheric effects. Especially the self-calibration will become an important method, to calibrate strong unknown structures and individual sources, to improve the image quality. Some of the strong unknown source can be an active Sun, a bursting Jupiter or even just strong men made radio frequency interference (RFI). As all observations presented in this thesis were done with the LOFAR station in Effelsberg dealing with the strong RFI is one of the main challenge in the calibration process. The developed software is afterwards used to produce single all-sky images of a LOFAR station. In Chapter 4 the procedure is explained how a high number of single all-sky observations were combined to map out the entire northern sky down to a declination of 0 degrees. The detected large-scale structures in this new map will be studied and compared to earliersurveys. In Chapter 5 a spectral analysis using the LOFAR survey at various frequencies is discussed. As part of this analysis the spectral index maps between frequencies below 50 MHz and the high frequency surveys at 408 MHz (Haslam et al., 1982), 820 MHz (Berkhuijsen, 1972) and 1400 MHz (Reich et al., 1981) will be investigated. This allows to study physical nature of the continuum emission and a possible flattening of the spectrum toward lower frequency due to thermal absorption. Furthermore the spectral index data will be used to estimate turn-overs at low frequencies and high frequency breaks and indicate a possible transition from thermal to non-thermal emission. In Chapter 6 a short analysis of the spectral properties of the strong radio source Cas A is investigated. In general measurements of this source during the last years show that the flux density is decreasing. The LOFAR measurements do confirm the predicted intensities of the Cas A model and also indicates similar flux densities for the strong radio source Cyg A. In order to determine the influence of the ionosphere on the polarization measurements pulsar observation are used. Chapter 7 will discuss the variations of the Rotation Measure (RM) values of the pulsars with time due to ionospheric fluctuations. Taking all corrections into account the polarization properties of Jupiter bursts can now be studied. The measurements show that the burst are highly linear- and circular-polarized and that the RM values per burst are frequency depended (Chapter 8). In Chapter 9 the polarization properties of the large-scale emission from the Milky Way will be discussed. For this linear polarization intensity maps are created and RM Synthesis will be used to determine the generally weak polarization emission

Approaches to the reuse of plan schemata in planning formalisms

Planning in complex domains is normally a resource and time consuming process when it is purely based on first principles. Once a plan is generated it represents problem solving knowledge. It implicitly describes knowledge used by the planning system to achieve a given goal state from a particular initial state. In classical planning systems, this knowledge is often lost after the plan has been successfully executed. If such a planner has to solve the same problem again, it will spend the same planning effort to solve it and is not capable of "learning\u27; from its "experience\u27;. Therefore it seems to be useful to save generated plans for a later reuse and thus, extending the problem solving knowledge possessed by the planner. The planning knowledge can now be applied to find out whether a problem can be solved by adapting an already existing plan. The aim of this paper is to analyze the problem of plan reuse and to describe the state of the art based on a variety of approaches which might contribute to a solution of the problem. It describes the main problems and results that could be of some relevance for the integration of plan reuse into a deductive planning formalism. As a result, this description of the state of the art leads to a deeper insight into the complex problem of plan reuse, but also shows that the problem itself is still far from being solved

Forecasting EduTech for the next decade. Scenario development teaching patterns in general versus academic education

Learning while studying is an individual process of actively acquiring knowledge through the co-construction of knowledge resources under supervision by teaching mentors. Mentoring activity typically consists of the interaction of two areas, namely the personal relationship between mentor and mentee, as well as individualized guidance on performance at the factual level, i.e. the partial result-based evaluation of the previous and advice on the future learning process. This in-process feedback is considered to be a key impact factor in learning success in international educational research, provided that it is as direct and as accurate as possible (Hattie & Yates, 2014). [... from the Indroduction

Nondestructive Testing for Graduate Students at Dresden International University and Iowa State University

Education in Nondestructive Evaluation is managed in different countries and different industrial sectors in various ways. The options vary from special courses for technicians with theoretical and practical knowledge, special courses focused on requirements in dedicated fields as aerospace and learning theoretical and practical issues from Level-3-Experts in the company during work. These systems, the knowledge of the practical aspects of the different methods for technicians who handle day by day with these techniques is splendidly constructed with top-quality. But for engineers, scientists and academics, who work on optimizing and enlarging methods, developing new methods and who use theoretical simulation models, it is important to get a broader scientific background. In this contribution we present a Master Course for Nondestructive Testing developed by the “Dresden International University” in close cooperation with the Technical University Dresden and the Fraunhofer IZFP. The students get an extensive background knowledge of a plurality of Nondestructive methods. The teachers comes from University as well as the Fraunhofer Institute, so it is secured that both the theoretical basics and novel research and developments are included. This is assisted by practical trainig at the Fraunhofer Institute. The requirement for participation is a successful finished study in engineering or science. The special feature on this Master course is its character as correspondence course. The main content is taught at distance learning courses using digital scripts and video conferences, questions are answered using E-mail and phone, too. For four weeks in the year the students have to show presence on campus in Dresden for practical courses and exams. The course of studies finishes with the international accredited certificate as Master of Science for Nondestructive Testing. This master degree can be compared the NDE Minor program that is offered at the Iowa State University. This is an additional certificate that graduate students in engineering can earn by taking a certain number of NDE related courses. In the paper we will briefly compare both Programs for NDE education for graduate students at both Universities

Design eines Virtuellen Supportteams.: Konzeptionelle Überlegungen und empirische Befunde zur Entwicklung Fakultät übergreifender virtueller Teams in der IT-Administration einer Hochschule

Körperschaften öffentlichen Rechts im Bildungsbereich zeichnen sich durch eine zunehmende Digitalisierung der Geschäftsprozesse aus. Dies trifft auch für Hochschulen zu, wobei die Produktion der Bildung (hier unter dem Begriff eLearning) ein intensiv untersuchtes Themenfeld ist, sowohl betreffen die Lehre selbst (Fischer et al., 2006)) als auch die dafür erforderlichen Services (Neumann, 2006). Weniger intensiv debattiert wird die Betreuung der IT-Administration als Thema der Organisationsentwicklung. ... Beispielhaft anhand des Bereiches Geistes- und Sozialwissenschaften der Technischen Universität Dresden thematisiert der Beitrag die aktuell anstehenden Gestaltungserfordernisse vor dem Hintergrund der Zielestellung, ein virtuelles Serviceteam für die Aufgaben der IT-Administration in Lehre, Forschung und Verwaltung über mehrere Fakultäten hinweg zu konzipieren. ... [Aus: Einleitung

The role of relatedness in the motivation and vitality of university students in online classes during social distancing

As part of the social distancing measures for preventing the spread of COVID-19, many university courses were moved online. There is an assumption that online teaching limits opportunities for fostering interpersonal relationships and students’ satisfaction of the basic need for relatedness – reflected by experiencing meaningful interpersonal connections and belonging – which are considered important prerequisites for student motivation and vitality. In educational settings, an important factor affecting students’ relatedness satisfaction is the teachers’ behavior. Although research suggests that relatedness satisfaction may be impaired in online education settings, to date no study has assessed how university lecturers’ relatedness support might be associated with student relatedness satisfaction and therefore, student motivation and vitality. This study tested this mediating relationship using data collected during the early days of the COVID-19 pandemic. The study also investigated whether the relations were moderated by a high affiliation motive which reflects a dispositional wish for positive and warm relationships. The possible importance of the communication channel selected by the lecturers (video chat yes/no) and the format of a class (lecture/seminar) were also investigated. In a sample of N = 337 students, we tested our hypotheses using structural equation model (SEM). Results confirmed mediation, but not moderation. The use of video chat (video call) seems to facilitate the provision of relatedness support but our data did not show that the format of a class was associated with relatedness. Our findings indicate that both teaching behavior and the technical format used to deliver lectures play important roles in student experiences with online classes. The results are discussed in light of other research conducted during the pandemic. (DIPF/Orig.

Use of aviation by climate change researchers: Structural influences, personal attitudes, and information provision

Aviation is a fast-growing sector, releasing more carbon dioxide per passenger kilometre than other transport modes. For climate change researchers, work-related travel – including for conferences and fieldwork – is a major carbon-emitting activity. At the same time, many argue that climate scientists have an important role in curbing their own aviation emissions to align their practices with their assertions in relation to emissions reduction. We examine the tensions between competing professional demands in relation to flying; measure levels of flying by climate and non-climate researchers; assess influences on choices and attitudes; and consider how information provision and structural changes might enable changes in practice. Study 1 entails a large, international survey of flying undertaken by climate change (including sustainability and environmental science) researchers and those from other disciplines (N = 1408). Study 2 tests effects of varying information provision on researchers’ behavioural intentions and policy support to reduce flying (N = 362). Unexpectedly, we find climate change researchers – particularly professors – fly more than other researchers, but are also more likely to have taken steps to reduce or offset their flying. Providing information about the impacts of aviation increases behavioural intentions and support for institutional policies to reduce flying, particularly amongst more pro-environmental respondents. However, while attitudinal factors (e.g., personal norm) predict willingness to reduce flying, structural/social factors (e.g., family commitments, location) are more important in predicting actual flying behaviour. Recent initiatives to develop a low-carbon and more inclusive research culture within climate science and the broader research community thus need to be supported by broader policies and technologies to encourage and enable low-carbon and avoided travel

Single azopyridine-substituted porphyrin molecules for configurational and electronic switching

A new azopyridine functionalized Ni–porphyrin was synthesized as a model compound for deposition and switch on surfaces. Two geometrically and electronically different states of single molecules on Au(111) were found by scanning tunneling microscopy/ spectroscopy and analyzed with density functional calculations

Novel Intraoperative Imaging of Gastric Tube Perfusion during Oncologic Esophagectomy—A Pilot Study Comparing Hyperspectral Imaging (HSI) and Fluorescence Imaging (FI) with Indocyanine Green (ICG)

Background: Novel intraoperative imaging techniques, namely, hyperspectral (HSI) and fluorescence imaging (FI), are promising with respect to reducing severe postoperative complications, thus increasing patient safety. Both tools have already been used to evaluate perfusion of the gastric conduit after esophagectomy and before anastomosis. To our knowledge, this is the first study evaluating both modalities simultaneously during esophagectomy. Methods: In our pilot study, 13 patients, who underwent Ivor Lewis esophagectomy and gastric conduit reconstruction, were analyzed prospectively. HSI and FI were recorded before establishing the anastomosis in order to determine its optimum position. Results: No anastomotic leak occurred during this pilot study. In five patients, the imaging methods resulted in a more peripheral adaptation of the anastomosis. There were no significant differences between the two imaging tools, and no adverse events due to the imaging methods or indocyanine green (ICG) injection occurred. Conclusions: Simultaneous intraoperative application of both modalities was feasible and not time consuming. They are complementary with regard to the ideal anastomotic position and may contribute to better surgical outcomes. The impact of their simultaneous application will be proven in consecutive prospective trials with a large patient cohort

RegulationSpotter: annotation and interpretation of extratranscriptic DNA variants

RegulationSpotter is a web-based tool for the user-friendly annotation and interpretation of DNA variants located outside of protein-coding transcripts (extratranscriptic variants). It is designed for clinicians and researchers who wish to assess the potential impact of the considerable number of non-coding variants found in Whole Genome Sequencing runs. It annotates individual variants with underlying regulatory features in an intuitive way by assessing over 100 genome-wide annotations. Additionally, it calculates a score, which reflects the regulatory potential of the variant region. Its dichotomous classifications, ‘functional’ or ‘non-functional’, and a human-readable presentation of the underlying evidence allow a biologically meaningful interpretation of the score. The output shows key aspects of every variant and allows rapid access to more detailed information about its possible role in gene regulation. RegulationSpotter can either analyse single variants or complete VCF files. Variants located within protein-coding transcripts are automatically assessed by MutationTaster as well as by RegulationSpotter to account for possible intragenic regulatory effects. RegulationSpotter offers the possibility of using phenotypic data to focus on known disease genes or genomic elements interacting with them. RegulationSpotter is freely available at https://www.regulationspotter.org