The 20 most recently published documents
Purpose: The present research aims on the one hand to provide a basic understanding of the challenges that young companies in growth face by discussing previous findings on this topic. On the other hand, this research project wants to generate new insights on specific challenges and possible learning processes by means of a theory-based examination of a case study.
Design/Methodology/Approach: The author of this study conducts a theory-based case study investigation. The study is based on two theoretical concepts which depict the phenomenon of challenges faced by young companies in growth in an abstract form: On the one hand, the "Tension-Balancing Management" according to Harald von Korflesch, which expresses the fundamental tension within entrepreneurial organizations, which in turn can be seen as a starting point for actual challenges. On the other hand, the "Tipping Points / Absorbative Capacities" framework by Phelps and colleagues, which links challenges (Tipping Points) that young companies will experience during their lifetime with required capabilities (Absorbative Capacities). Guided by these theories, rich data from interviews, observations and documents from the case are collected and analyzed in order to generate insights.
Findings: On the one hand, challenges of young growing companies can be described on a superordinate level with the help of the two theoretical concepts. On the other hand, the analysis also shows that, above all, a fine-grained, individual approach is needed to adequately depict challenges and learning processes.
Research Limitations: The main limitation of the present study is the single-case design. The fact that only one specific case was examined means that the insights gained from this cannot be automatically replicated to comparable cases. The simultaneous examination of multiple cases could thus make the results more stable.
Originality/Value: The qualitative investigation of growth-related challenges by means of a specific case study creates an in-depth and profound understanding of complex interactions in the growth of young companies. In addition, the assumptions of both theoretical concepts are tested on a real case, thus enabling theoretical and practical implications to be identified.
In this thesis we examined the question whether personality traits of early child care workers influence process quality in preschool.
Research has shown that in educational settings such as preschool, pedagogical quality affects children’s developmental outcome (e.g. NICHD, 2002; Peisner-Feinberg et al., 1999). A substantial part of pedagogical quality known to be vital in this respect is the interaction between teacher and children (e.g., Tietze, 2008). Results of prior classroom research indicate that the teachers’ personality might be an important factor for good teacher-child-interaction (Mayr, 2011). Thus, personality traits might play a vital role for the interaction in preschool. Therefore, the aims of this thesis were to a) identify pivotal personality traits of child care workers, b) assess ideal levels of the identified personality traits and c) examine the relationship between pivotal personality traits and process quality. On that account, we conducted two requirement analyses and a video study. The results of these studies showed that subject matter experts (parents, child care workers, lecturers) partly agreed as to which personality traits are pivotal for child care workers. Furthermore, the experts showed high consensus with regard to the minimum, ideal and maximum personality trait profiles. Furthermore, child care workers whose profiles lay closer to the experts’ ideal also showed higher process quality. In addition, regression analyses showed that the child care workers’ levels of the Big Two (Communion and Agency) related significantly to their process quality.
Spektroskopie zweiatomiger Moleküle bei Einstrahlung ultrakurzer Laserpulse und ihre Anwendung
(2020)
Even with moderate pulse energies and average powers, ultrashort pulse lasers achieve very high peak powers, whose effect on matter is fundamentally different from that of other light sources. The high electric field strength does not only cause an increase of optically nonlinear effects such as second harmonic generation, but it is also responsible for the “cold“ ablation, which leads to colder plasmas. An investigation of these two circumstances in terms of a simplification of the pulse duration measurement and an improvement of the molecular formation in cooling plasmas is the topic of this work. In this context, it is shown that when selecting suitable process parameters, especially when purposefully defocusing the medium, the use of ultrashort pulse lasers improves the spectroscopy of several emitting molecules such as aluminum oxide. Therefore, their detection is possible even without the time-resolving spectrometers required in literature. In addition, ultrashort pulses enable spatially resolved crystallization of zinc oxide on zinc surfaces prepared by basic means. The resulting wurtzites usually align their c-axis approximately perpendicular to the underlying surface and can be used to generate scattered second harmonics. Fiber-based femtosecond lasers with pulse energies in the microjoule range, pulse durations of a few 100fs and very low maintenance requirements have proven to be a powerful instrument for these purposes. For measuring the pulse duration, the high pulse energy also enables the usage of frequency doublers with much lower conversion eciencies. Despite nonuniform crystal axes, the scattering second harmonic generating aluminum nitride has proven to be particularly suitable for optical autocorrelation. Compared to the commonly used monocrystalline beta-barium borate, the sintered aluminum nitride ceramic plates facilitate the adjustment, simplify the material handling and reduce the expenses by two to three orders of magnitude. The method developed in this work is therefore also suitable for confirmatory measurements of the pulse duration during the production process of such systems – especially when the occurring pulse energies are high or rather too high for beta-barium borate.
In Western personnel psychology, competence- and control beliefs (CCB) are of widespread use to predict typical work-related outcomes such as well-being, achievement motivation and job performance. The predictive value and comprehension of CCB in East Africa is examined, comparing a Kenyan target with a German source sample (N=143). Responses to personality tests included qualitative interviews on items capturing control orientations (self concept of ability, internality, powerful others, and chance). Linear regression analyses,
explorative factor analyses, and a procrustean target rotation showed comparable, but not fully congruent predictability for the connection of CCB with outcome variables. Factor structures of control responses did not resemble each other sufficiently. Content analyses including scale intercorrelations, quantitative and qualitative item information served for an explanation of this predictability gap, specifying differences between the German and Kenyan samples that are associated with the social-relational domain of personality. Results
fit in the picture depicted by the African Ubuntu philosophy and the South African Personality Inventory project (SAPI), both emphasizing social-relational aspects. In particular, the powerful others control orientation diverges the most between the cultures. Being perceived as a negative and external factor in the German sample with its individualistic culture, powerful others is of mixed emotional quality and just as well internal, when asked for in the Kenyan sample with its Ubuntu-worldview. An uncritical transfer of CCB measures from one culture to another is assumed to be inappropriate. More emic-etic based research is demanded concerning intra- and intercultural variability of CCB to depict a
transcultural applicable model.
The history of human kind is characterized by social conflict. Every conflict can be the starting point of social change or the escalation into more destructive forms. The social conflict in regard to rising numbers of refugees and their acceptance that arose in most host countries in 2015 already took on destructive forms – in Germany, right-wing extremists attacked refugee shelters and even killed multiple people, including political leaders who openly supported refugees. Thus, incompatible expectancies and values of different parts of the society led to violent action tendencies, which tremendously threaten intergroup relations. Psychological research has developed several interventions in past decades to improve intergroup relations, but they fall short, for example, when it comes to the inclusion of people with extreme attitudes and to precisely differentiate potential prosocial outcomes of the interventions. Thus, this dissertation aimed to a) develop psychological interventions, that could also be applied to people with more extreme attitudes, thereby putting a special emphasis on collecting a diverse sample; b) gain knowledge about target- and outcome specific effects: Who benefits from which intervention and how can specific prosocial actions be predicted in order to develop interventions that guide needs-based actions; and c) shed light on potential underlying mechanisms of the interventions.
The dissertation will be introduced by the socio-political background that motivated the line of research pursued, before providing an overview of the conceptualization of social conflicts and potential psychological inhibitors and catalyzers for conflict transformation. Based on past research on socio-psychological interventions and their limitations, the aims of the dissertation will be presented in more detail, followed by a short summary of each manuscript. Overall, the present thesis comprises four manuscripts that were summarized in the general discussion into a road map for social-psychological interventions to put them into a broader perspective. The road map aspires to provide recommendations for increasing – either approach-oriented or support-oriented actions – by the socio-psychological interventions for a variety of host society groups depending on their pre-existing attitude towards refugees.
A Paradoxical Intervention targeting central beliefs of people with negative attitudes towards refugees influenced inhibitory and catalyzing factors for conflict transformation over the course of three experiments – thereby providing an effective tool to establish approach-oriented action tendencies, such as the willingness to get in contact with refugees. Further, the dissertation presents a novel mechanism – namely Cognitive Flexibility – which could explain the Paradoxical Interventions’ effect of past research. By positively affecting a context-free mindset, the Paradoxical Intervention could impact more flexible thought processes in general, irrespective of the topic tackled in the Paradoxical Intervention itself. For people with rather positive attitudes addressing emotions may increase specific support-oriented action tendencies. The dissertation provides evidence of a positive relation between moral outrage and hierarchy-challenging actions, such as solidarity-based collective action, and sympathy with prosocial hierarchy-maintaining support-oriented actions, such as dependency-oriented helping. These exclusive relations between specific emotions and action intentions provide important implications for the theorizing of emotion-behavior relations, as well as for practical considerations. In addition, a diversity workshop conducted with future diplomats showed indirect effects on solidarity-based collective action via diversity perception and superordinate group identification, thereby extending past research by including action intentions and going beyond the focus on grassroot-initiatives by presenting an implementable intervention for future leaders in a real world context.
Taken together, this dissertation provides important insights for the development of socio-psychological interventions. By integrating a diverse sample, including members of institutions on meso- and macro-levels (non-governmental organizations and future politicians) of our society, this dissertation presents a unique multi-perspective of host society members on the social conflict of refugee acceptance and support. Thereby, this work contributes to theoretical and practical advancement of how social psychology can contribute not only to negative peace – by for example (indirectly) reducing support of violence against refugees – but also to positive peace – by for example investigating precursors of hierarchy-challenging actions that enable equal rights.
The scientific interest in nonsuicidal self-injury (NSSI) has increased in the last two decades. High prevalence and comorbidity rates, low quality of life and increased risk of suicidality highlight the importance of this research field. The present thesis focuses on intra- and interpersonal factors associated with the development and maintenance of NSSI.
The aim of study 1 was the examination of personality traits of adolescents with NSSI without Borderline Personality Disorder (NSSI-BPD), adolescents with NSSI and BPD (NSSI+BPD), clinical controls (CC) and nonclinical controls (NC). Results showed that adolescents with NSSI disorder scored significantly higher on novelty seeking and harm avoidance and lower on persistence, self-directedness, and cooperativeness than CC. In adolescents with NSSI+BPD this personality pattern was even more pronounced than in adolescents with NSSI-BPD.
Adolescents´ NSSI leads to distress that affects the whole family system, often resulting in conflicts and disrupted family communication and functioning. Parents report feelings of distress, insecurity and helplessness. Adolescents with NSSI report more parental criticism and control and less support than adolescents without NSSI. Study 2 investigated the parenting behavior in families of adolescents with NSSI. Adolescents with NSSI reported less maternal warmth and support than NC adolescents. Mothers of adolescents with NSSI showed higher psychopathology scores than NC mothers and less parental satisfaction than CC and NC mothers.
Siblings are also reported to suffer from changes in family dynamics. The aim of study 3 was to examine the sibling relationship quality of adolescents with NSSI, CC and NC. Siblings reported a wide range of negative emotional and familial consequences as a result of their sister´s NSSI. Siblings of adolescents with NSSI experienced significantly more coercion in the relationship with their sister compared to CC and NC siblings. Adolescents with NSSI reported significantly less warmth and empathy in the sibling relationship and higher rivalry scores between their siblings and themselves than NC adolescents. For both, adolescents with NSSI and their siblings, associations were found between sibling relationship quality and internalizing problems.
Study 4 aimed to further explore the family emotional climate. Therefore, the level of expressed emotion (EE) was assessed in adolescents with NSSI, CC, NC and their mothers. Parental high EE (HEE) is linked to adolescent NSSI, especially parental criticism seems to be strongly associated with NSSI. Previous research into NSSI and EE has focused on parental EE, however, the conceptualization of EE as a unidirectional construct from parent to child may present an incomplete picture. Therefore, the current study included both, adolescent and maternal EE. Adolescents in the NSSI and CC group more often met criteria for HEE than NC. Adolescents with NSSI exhibited significantly more covert criticism and critical tone toward their mothers than CC and NC. HEE of adolescents with NSSI was associated with a range of difficulties in emotion regulation. For the total sample, moderate concordance was found between adolescents and mothers EE-status.
The research presented in this thesis has important clinical implications. The differences in personality traits of adolescents with NSSI with and without BPD underline the need for a dimensional personality assessment as well as specific treatment programs for adolescents with NSSI-BPD. Problems within the family are frequent triggers for NSSI. Therefore, interventions for adolescents with NSSI should include both, the improvement of emotion regulation and family interaction and communication. Along with the reduction of negative relationship aspects, psychotherapy should also focus on the enhancement of positive relationship quality. The emotional burden of family members stresses the need for emotional and practical support for parents and siblings.
Interest in crowdfunding has been increasing in recent years, both from the economy and the scientific community. Besides artists and entrepreneurs, researchers are now also funding their projects through many small contributions from the crowd. However, the perceived use in Germany does not reflect the benefits of a crowdfunding campaign, especially in international comparison. This study investigates this issue by identifying the motives and barriers for crowdfunding in order to formulate recommendations for research institutions to encourage the use of crowdfunding.
By means of a literature review, first insights are gained which are then used to conduct qualitative interviews with eleven researchers who successfully completed a crowdfunding campaign. The results indicate that researchers in Germany use crowdfunding primarily to raise awareness for the subject and the scientific community in general. The initial assumption of the speed of crowdfunding as a motive was contradicted by the experts. The major barriers are the immense effort involved in a campaign and the lack of reputation for the concept of crowdfunding by German scientists. In addition, only subjects and projects with a high public relevance and funding volume of up to five digits are recommended for crowdfunding. Furthermore, the public exposure of the experts during the campaign was identified as an additional barrier.
These findings lead to three recommendations for research institutions to increase the use of crowdfunding: Firstly, universities should raise awareness for the subject of crowdfunding as an additional form of research funding and highlight the benefits of a crowdfunding campaign. Secondly, universities should cooperate with crowdfunding partners and utilize the networking capacities of a university. Lastly, universities should provide support to distribute the workload among interdisciplinary teams in order to enhance the effortreturn ratio of a crowdfunding campaign.
The chosen methodology and the scope of the thesis enable further research that might examine the perspective of the universities and the conditions in other countries. In addition, a largescale quantitative survey is required to validate the identified concepts statistically.
In the context of augmented reality we define tracking as a collection of methods to obtain the position and orientation (pose) of a user. By means of various displaying techniques, this ensures a correct visual overlay of graphical information onto the reality perceived. Precise results for calculation of the camera pose are gained by methods of image processing, usually analyzing the pixels of an image and extracing features, which can be recognized over the image sequence. However, these methods do not regard the process of image synthesis or at least in a very simplyfied way. In contrast, the class of model-based methods assumes a given 3D model of the observed scene. Based on the model data features can be identified to establish correspondences in the camera image. From these feature correspondences the camera pose is calculated. An interesting approach is the strategy of analysis-by-synthesis, regarding the computer graphics rendering process for extending the knowledge about the model by information from image synthesis and other environment variables.
In this thesis the components of a tracking system are identified and further it is analyzed, to what extend information about the model, the rendering process and the environment can contribute to the components for improvement of the tracking process using analysis-by-synthesis. In particular, by using knowledge as topological information, lighting or perspective, the feature synthesis and correspondence finding should lead to visually unambiguous features that can be predicted and evaluated to be suitable for stable tracking of the camera pose.
Social media platforms such as Twitter or Reddit allow users almost unrestricted access to publish their opinions on recent events or discuss trending topics. While the majority of users approach these platforms innocently, some groups have set their mind on spreading misinformation and influencing or manipulating public opinion. These groups disguise as native users from various countries to spread frequently manufactured articles, strong polarizing opinions in the political spectrum and possibly become providers of hate-speech or extremely political positions. This thesis aims to implement an AutoML pipeline for identifying second language speakers from English social media texts. We investigate style differences of text in different topics and across the platforms Reddit and Twitter, and analyse linguistic features. We employ feature-based models with datasets from Reddit, which include mostly English conversation from European users, and Twitter, which was newly created by collecting English tweets from selected trending topics in different countries. The pipeline classifies language family, native language and origin (Native or non-Native English speakers) of a given textual input. We evaluate the resulting classifications by comparing prediction accuracy, precision and F1 scores of our classification pipeline to traditional machine learning processes. Lastly, we compare the results from each dataset and find differences in language use for topics and platforms. We obtained high prediction accuracy for all categories on the Twitter dataset and observed high variance in features such as average text length especially for Balto-Slavic countries.
Die Studien der vorliegenden Arbeit untersuchen geschlechtsspezifisch-emotionale Reaktionsmuster auf stärkere und weniger stark emotionalisierte Texte verschiedener Textarten zu negativen Themen. Zusätzlich finden verschiedene Ausprägungen von Geschlechterstereotypen und dahingehend mögliche Zusammenhänge mit emotionalen Reaktionen Berücksichtigung. Versuchspersonen wurden mit Textmaterial konfrontiert und sollten daraufhin mit Hilfe des Emotionsfragebogens M-DAS ihre emotionalen Reaktionen bewerten. Frauen zeigten eine stärkere Ergriffenheit in Bezug auf das Textmaterial im Allgemeinen und besonders auf emotionalisiertes Textmaterial. Gemischte Ergebnisse zeigten sich in Bezug auf geschlechtertypische Textarten. Eine Sachtextpräferenz der Männer ließ sich ebensowenig signifikant belegen wie die erwartete stärkere Vorliebe der Frauen für literarische Texte. Geschlechtsspezifische Emotionen wurden weitestgehend erwartungskonform berichtet: Frauen reagierten mit stärkerer Angst und Trauer auf das Textmaterial, Männer mit stärkerer Verachtung. Die Ergebnisse in Bezug auf Wut sind gemischt, in einigen Fällen wurde Wut jedoch stärker von den Frauen berichtet. Die Untersuchung der Zusammenhänge zwischen internalisierten Stereotypen ergab Einflüsse hauptsächlich von weiblichen Stereotypen auf emotionale Reaktionen, männliche Stereotype konnten nur in einer Teilfragestellung als Einflussfaktor ausgemacht werden. Emotionsbezogene Stereotype wiesen keine Zusammenhänge mit emotionalen Reaktionen auf. Insgesamt belegen die Ergebnisse der Arbeit, dass sich geschlechterspezifische Unterschiede in emotionalen Reaktionen finden lassen.
"We've allways been in a culture where more is more, and suddenly we're in a culture whrere less is a better quality of life. It's pretty revolutionary." - Bill Stewart
The transformation of society in recent years has brought significant changes, including the trend towards more conscious consumption and more sustainable use of resources. Traditional patterns have increasingly receded into the background, stereotypes have been broken and the standards of assessment have been redefined. And so we have arrived at a time when owning less is considered as more valuable and minimalism has become a new trend. The transformation of the social norms has also led to changes in the economy. Due to recent changes, sharing economy has emerged as a new, rapidly growing sector of the economy. In simple terms, the business model can be put as the sharing of unused resources in exchange for (non-) monetary incentives.
The present bachelor thesis deals with the implementation of the sharing economy in the B2B sector. The advantages and disadvantages of the business model have been shown and opportunities and risks of the implementation in companies have been described. Furthermore, it is examined, which conditions of the consumer sector are suitable for implementation in the B2B model and which new factors should be taken into consideration. Based on the literature analysis, a B2C model has been developed. In addition, qualitative interviews were carried out. Among the experts were the managers and CEO of a medium-sized IT company. The results of the evaluation, based on Mayring (2002), helped to develop a decision model for implementation of sharing economy in B2B and to answer the research questions.
Based on the results of the interviews, key framework conditions were transferred from the private sharing sector to the B2B model. In addition, further factors were identified. Depending on the decision model, it was possible to show the requirements for the implementation of sharing economy in the B2B environment and identify the challenges to be faced.
Die Forschungsarbeit beschäftigt sich mit der zentralen Frage, welche Erfolgsfaktoren einen Effekt auf eine erfolgreiche Crowdfunding Kampagne haben. Als Untersuchungsfeld stehen deutsche Startup-Unternehmen im Fokus, die bereits erfolgreiche CrowdfundingKampagnen durchgeführt haben.
Zur Beantwortung dieser Frage wird zunächst eine systematische Literaturanalyse durchgeführt, durch die relevante Erfolgsfaktoren für eine Crowdfunding-Kampagne ermittelt werden. Diese Faktoren werden anschließend einem Mixed-Method-Ansatz unterzogen, bei dem qualitative Ergebnisse, basierend auf einer Fallstudienforschung, mit den statistisch ausgewerteten quantitativen Ergebnissen aus der Fragebogenforschung verglichen und überprüft werden. Dabei liegt der Fokus insbesondere auf der Identifikation von signifikanten Wirkungszusammenhängen zwischen den Erfolgsfaktoren und einer erfolgreichen Crowdfunding-Kampagne.
Im Ergebnis konnten diesbezüglich Wirkungszusammenhänge innerhalb dieser Thesis nachgewiesen werden. Sechs der festgestellten Zusammenhänge aus der qualitativen Analyse werden durch die quantitative Analyse bestätigt. Es konnte jedoch keine Signifikanz der Korrelationen festgestellt werden. Auch die Hypothese, dass sich die Erfolgsaussichten einer Kampagne durch eine höhere Anzahl jeweils kombinierter Erfolgsfaktoren erhöhen, wurde sowohl in der qualitativen als auch in der quantitativen Betrachtung widerlegt. Demnach galt es für den Autor der vorliegenden Thesis künftige Forschungsfelder zu definieren, die die ermittelten Ergebnisse erweitern und konkretisieren. Es bleibt beispielsweise einer weiterführenden Forschung überlassen, zu klären, ob bestimmte Kombinationen der Erfolgsfaktoren zu signifikanten Wirkungszusammenhängen führen. Darüber hinaus bietet sich eine weiterführende statistische Regressionsanalyse an, um die kausalen Effekte zu untersuchen und Prognosen für erfolgreiche Crowdfunding-Kampagnen zu formulieren.
Initial goal of the current dissertation was the determination of image-based biomarkers sensitive for neurodegenerative processes in the human brain. One such process is the demyelination of neural cells characteristic for Multiple sclerosis (MS) - the most common neurological disease in young adults for which there is no cure yet. Conventional MRI techniques are very effective in localizing areas of brain tissue damage and are thus a reliable tool for the initial MS diagnosis. However, a mismatch between the clinical fndings and the visualized areas of damage is observed, which renders the use of the standard MRI diffcult for the objective disease monitoring and therapy evaluation. To address this problem, a novel algorithm for the fast mapping of myelin water content using standard multiecho gradient echo acquisitions of the human brain is developed in the current work. The method extents a previously published approach for the simultaneous measurement of brain T1, T∗ 2 and total water content. Employing the multiexponential T∗ 2 decay signal of myelinated tissue, myelin water content is measured based on the quantifcation of two water pools (myelin water and rest) with different relaxation times. Whole brain in vivo myelin water content maps are acquired in 10 healthy controls and one subject with MS. The in vivo results obtained are consistent with previous reports. The acquired quantitative data have a high potential in the context of MS. However, the parameters estimated in a multiparametric acquisition are correlated and constitute therefore an ill-posed, nontrivial data analysis problem. Motivated by this specific problem, a new data clustering approach is developed called Nuclear Potential Clustering, NPC. It is suitable for the explorative analysis of arbitrary dimensional and possibly correlated data without a priori assumptions about its structure. The developed algorithm is based on a concept adapted from nuclear physics. To partition the data, the dynamic behavior of electrically even charged nucleons interacting in a d-dimensional feature space is modeled. An adaptive nuclear potential, comprised of a short-range attractive (Strong interaction) and a long-range repulsive term (Coulomb potential), is assigned to each data point. Thus, nucleons that are densely distributed in space fuse to build nuclei (clusters), whereas single point clusters are repelled (noise). The algorithm is optimized and tested in an extensive study with a series of synthetic datasets as well as the Iris data. The results show that it can robustly identify clusters even when complex configurations and noise are present. Finally, to address the initial goal, quantitative MRI data of 42 patients are analyzed employing NPC. A series of experiments with different sets of image-based features show a consistent grouping tendency: younger patients with low disease grade are recognized as cohesive clusters, while those of higher age and impairment are recognized as outliers. This allows for the definition of a reference region in a feature space associated with phenotypic data. Tracking of the individual's positions therein can disclose patients at risk and be employed for therapy evaluation.
In dieser Arbeit wird der Frage nachgegangen, wie beispielsweise die homosexuelle AfD-Frontfrau Alice Weidel ihre Mitgliedschaft in einer Partei, die als konservativ und homophob gilt, begründet. Neben der Rede ihres Coming-Outs wird außerdem das Parteiprogramm der AfD hinsichtlich der Themen Homosexualität und Migration analysiert.
Abdriftbedingte Pflanzenschutzmittelrückstände in unbehandelten Kulturen auf angrenzenden Flächen
(2020)
Die vorliegende Arbeit beschäftigt sich mit der Abdrift von Pflanzenschutzmitteln (PSM), die auf Lebensmittelkulturen in angrenzenden Flächen, insbesondere in benachbarte Haus- und Kleingärten, gelangt. In einer Reihe von Windtunnelversuchen wurde die Abdrift von PSM aus Flächen- und Raumkulturen während der Applikation mit zwei verschiedenen Testsystemen nachgestellt. Das Testsystem Flächenkultur simuliert die Applikation auf Flächenkulturen, das Testsystem Raumkultur die auf Raumkulturen. Auf der Nicht-Zielfläche wurden die auf Grund von Abdrift entstandenen Rückstände des verwendeten Tracers Pyranin nach der Applikation entfernungsabhängig auf den Lebensmittelkulturen Kopfsalat, Erdbeeren und Tomaten gemessen. Durch die gleichzeitige Messung der Bodendeposition konnten die Messwerte mit Hilfe von Regressionsgleichungen (R² = 0,88 bis 0,97) in Bezug zu den Abdrifteckwerten (AEW) gebracht werden. Dadurch war es möglich, erste Abschätzungen der Höhe von Rückständen vorzunehmen, die über Abdrift von landwirtschaftlichen Flächen auf benachbarte Lebensmittelkulturen im Freiland gelangen können. Diese Abschätzung ist zunächst limitiert auf die drei Versuchspflanzen. Die Versuche zeigen, dass sich die meisten durch Abdrift entstehenden Rückstände auf Salatköpfen wieder finden, gefolgt von Erdbeeren und Tomaten.
Neben dem experimentellen Teil wurden Analysen mit Geoinformationssystemen (GIS) durchgeführt, um die Nachbarschaftsverhältnisse zwischen landwirtschaftlich genutzten Flächen und Gartenflächen für ganz Deutschland und speziell für Rheinland-Pfalz (RLP) zu analysieren. Dazu wurden für die deutschlandweiten Berechnungen die Daten des amtlichen topographisch-kartographischen Informationssystems (ATKIS) und für die RLP-weiten Berechnungen die Daten des amtlichen Liegenschaftskatasterinformationssystem (ALKIS) verwendet. Beachtet werden muss, dass auf Grund der Datenbeschaffenheit eine Abgrenzung der Gartenflächen zu Wohnflächen nicht möglich ist. Deutschlandweit liegen etwa 1,1 % aller potentiellen Gartenflächen innerhalb eines 5 m Pufferbereichs um Raumkulturen bzw. innerhalb eines 2 m Pufferbereichs um Flächenkulturen. Für RLP sind es 0,75 %. Mit Hilfe eines Landbedeckungsdatensatzes der Fa. RLP AgroScience GmbH und den ALKIS-Daten konnte jedoch die exakte Gartenfläche für RLP auf 47.437 ha bestimmt werden. Basierend auf dieser Datengrundlage liegen 1,2 % der Gartenfläche von RLP innerhalb der genannten Pufferbereiche. Des Weiteren ergaben Berechnungen, dass 3 % der Gärten in RLP direkt angrenzend zu landwirtschaftlich genutzten Flächen liegen.
Im Rahmen dieser Arbeit wurden nicht nur Gärten betrachtet, die an landwirtschaftliche Flächen grenzen, sondern auch Nachbarschaftsverhältnisse zwischen ökologisch und konventionell bewirtschafteten Flächen untersucht. Diese Berechnungen erfolgten mit den Daten des Integrierten Verwaltungs- und Kontrollsystems (InVeKoS). Insgesamt grenzen in RLP 47,1 % aller ökologisch bewirtschafteten Flächen unmittelbar an konventionell bewirtschaftete Flächen an.
Stream ecosystems are one of the most threatened ecosystems worldwide due to their exposure to diverse anthropogenic stressors. Pesticides appear to be the most relevant stressor for agricultural streams. Due to the current mismatch of modelled and measured pesticide concentrations, monitoring is necessary to inform risk assessment or improve future pesticide approvals. Knowing if biotic stress responses are similar across large scales and long time frames could ultimately help in estimating protective stressor thresholds.
This thesis starts with an overview of entry pathways of pesticides to streams as well as the framework of current pesticide monitoring and gives an outline of the objectives of the thesis. In chapter 2, routine monitoring data based on grab sampling from several countries is analysed to identify the most frequently occurring pesticide mixtures. These mixtures are comprised of relatively low numbers of pesticides, of which herbicides are dominating. The detected pesticide mixtures differ between regions and countries, due to differences in the spectrum of analysed compounds and limits of quantification. Current routine monitoring does not include sampling during pesticide peaks associated with heavy rainfall events which likely influences the detected pesticide mixtures. In chapter 3, sampling rates of 42 organic pesticides for passive sampling are provided together with recommendations for the monitoring of field-relevant peaks. Using this information, in chapter 4 a pesticide gradient is established in an Eastern European region where agricultural intensity adjacent to sampled streams ranges from low to high. In contrast to current routine monitoring, rainfall events were sampled and a magnitude of pesticides were analysed. This led to the simultaneous detection of numerous pesticides of which one to three drive the pesticide toxicity. The toxicity, however, showed no relationship to the agricultural intensity. Using microcosms, the stress responses of fungal communities, the hyphomycetes, and the related ecosystem function of leaf decomposition, is investigated in chapter 5. Effects of a field-relevant fungicide mixture are examined across three biogeographical regions for three consecutive cycles of microbial leaf colonisation and decomposition. Despite different initial communities, stress responses as well as recoveries were similar across biogeographical regions, indicating a general pattern.
Overall, this thesis contributes to an improved understanding of occurrence and concentrations of pesticides mixtures in streams, their monitoring and impact on an ecosystem function. We showed that estimated pesticide toxicities reach levels that affect non-target organisms and thereby potentially whole ecosystems. Routine monitoring, however, likely underestimates the threat by pesticides. Effects leading to a loss in biodiversity or functions in streams ecosystems can be reduced by reassessing approved pesticides with ongoing targeted monitoring and increased knowledge of effects caused by these pesticides.
In dieser Arbeit werden die schottischen Liedbearbeitungen Ludwig van Beethovens auf ihre möglichen gälischen Vorläufer untersucht und in ihrem historischen Kontext aus einer gälischen Perspektive betrachtet. Ihre Liedbiographien werden um Vorläufer ergänzt und vervollständigt, die vom dem schottischen Auftraggeber Beethovens, George Thomson teilweise vorsätzlich unterschlagen wurden. Gründe hierfür sind in der politischen und kulturellen Unterdrückung der gälischen Sprachgemeinschaft Schottlands zu finden. Handelt es sich wirklich um anonyme Volkslieder, oder auch um Kompositionen bekannter Musiker aus der gälischen Kultur? Welche Veränderungen erfuhren sie im Zuge der Anonymisierung und der Degradierung zur Volksmusik, sowie der anschließenden Neuausrichtung in der schottischen Nationalmusik? Zu 12 der schottischen Lieder Beethovens sind ausführliche Liedbiographien mit allen gälischen Liedtexten, deutscher Übersetzung und den historischen Hintergründen der gälischen Vorläufer und ihrer Notierungen entstanden.
The three biodegradable polymers polylactic acid (PLA), polyhydroxybutyrate (PHB) and polybutylene adipate terephthalate (PBAT) were coated with hydrogenated amorphous carbon layers (a-C:H) in the context of this thesis. A direct alignment of the sample surface to the source was chosen, resulting in the deposition of a robust, r-type a-C:H. At the same time, a partly covered silicon wafer was placed together with the polymers in the coating chamber and was coated. Silicon is a hard material and serves as a reference for the applied layers. Due to the hardness of the material, no mixed phase occurs between the substrate and the applied layer (no interlayer formation). In addition, the thickness of the applied layer can be estimated with the help of the silicon sample.
The deposition of the layer was realized by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD). For the coating the samples were pre-treated with an oxygen plasma. Acetylene was used as precursor gas for the plasma coating. Coatings with increasing thickness in 50 nm steps from 0-500 nm were realised.
The surface analysis was performed using several techniques: The morphology and layer stability were analyzed with scanning electron microscopy (SEM) measurements. The wettability was determined by contact angle technique. In addition, the contact angles provide macroscopic information about the bond types of the carbon atoms present on the surface. For microscopic analysis of the chemical composition of the sample and layer surfaces, diffuse reflectance Fourier transform infrared spectroscopy (DRIFT) as well as synchrotron based X-ray photon spectroscopy (XPS) and near edge X-ray absorption fine structure spectroscopy (NEXAFS) were used.
All coated polymers showed several cases of layer failure due to internal stress in the layers. However, these were at different layer thicknesses, so there was a substrate effect. In addition, it is visible in the SEM images that the coatings of PLA and PHB can cause the applied layer to wave, the so-called cord buckling. This does not occur with polymer PBAT, which indicates a possible better bonding of the layer to the polymer. The chemical analyses of the layer surfaces show for each material a layer thickness dependent ratio of sp² to sp³ bonds of carbon, which alternately dominate the layer. In all polymers, the sp³ bond initially dominates, but the sp² to sp³ ratio changes at different intervals. Although the polymers were coated in the same plasma, i.e. the respective layer thicknesses (50 nm, 100 nm, ...) were applied in the same plasma process, the respective systems differed considerably from each other. A substrate effect is therefore demonstrably present. In addition, it was found that a change in the dominant bond from sp³ to sp² is an indication ofan upcoming layer failure of the a-C:H layer deposited on the polymer. In the case of PLA, this occurs immediately with change to sp² as the dominant bond; in the case of PHB and PBAT, this occurs with different delay to increased layer thicknesses (at PHB 100 nm, at PBAT approx. 200 nm.
Overall, this thesis shows that there is a substrate effect in the coating of the biodegradable polymers PLA, PHB and PBAT, since despite the same coating there is a different chemical composition of the surface at the respective layer thicknesses. In addition, a layer failure can be predicted by analyzing the existing bond.
Studies in recent years have demonstrate adolescents and young adults to have a deficient data protection competence, however children and adolescents between the ages of ten and 13 were mostly not focus of these studies. Therefore, the guiding question of the work is how data protection competence is developed in children and adolescents at a young age in order to be able to infer suitable, educational concepts for this age group. At the beginning of the work, a data protection competence model is derived from a media competence model, which serves as the basis for the further field investigation. A survey was carried out at general secondary schools in Rhineland-Palatinate, which shows that the respondents still have sufficiently developed Risk Assessment Competence, but were insufficiently developed in terms of knowledge, Selection and Usage Competence and the Implementation Competence. Recommendations for actions are given in the last part of the work – containing learning goal descriptions to be possibly implemented in an educational framework – in order to address this issue.
