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1. A coupled-mechanisms modelling framework for neurodegeneration

Author

He, Tiantian, Thompson, Elinor, Schroder, Anna, Oxtoby, Neil P., Abdulaal, Ahmed, Barkhof, Frederik, and Alexander, Daniel C.

Subjects
Quantitative Biology - Quantitative Methods, Computer Science - Computational Engineering, Finance, and Science, Quantitative Biology - Neurons and Cognition
Abstract

Computational models of neurodegeneration aim to emulate the evolving pattern of pathology in the brain during neurodegenerative disease, such as Alzheimer's disease. Previous studies have made specific choices on the mechanisms of pathology production and diffusion, or assume that all the subjects lie on the same disease progression trajectory. However, the complexity and heterogeneity of neurodegenerative pathology suggests that multiple mechanisms may contribute synergistically with complex interactions, meanwhile the degree of contribution of each mechanism may vary among individuals. We thus put forward a coupled-mechanisms modelling framework which non-linearly combines the network-topology-informed pathology appearance with the process of pathology spreading within a dynamic modelling system. We account for the heterogeneity of disease by fitting the model at the individual level, allowing the epicenters and rate of progression to vary among subjects. We construct a Bayesian model selection framework to account for feature importance and parameter uncertainty. This provides a combination of mechanisms that best explains the observations for each individual from the ADNI dataset. With the obtained distribution of mechanism importance for each subject, we are able to identify subgroups of patients sharing similar combinations of apparent mechanisms., Comment: MICCAI 2023

Published
2023

2. Rician likelihood loss for quantitative MRI using self-supervised deep learning

Author

Parker, Christopher S., Schroder, Anna, Epstein, Sean C., Cole, James, Alexander, Daniel C., and Zhang, Hui

Subjects
Computer Science - Machine Learning, Computer Science - Computational Engineering, Finance, and Science, Electrical Engineering and Systems Science - Image and Video Processing, Quantitative Biology - Quantitative Methods, Statistics - Machine Learning
Abstract

Purpose: Previous quantitative MR imaging studies using self-supervised deep learning have reported biased parameter estimates at low SNR. Such systematic errors arise from the choice of Mean Squared Error (MSE) loss function for network training, which is incompatible with Rician-distributed MR magnitude signals. To address this issue, we introduce the negative log Rician likelihood (NLR) loss. Methods: A numerically stable and accurate implementation of the NLR loss was developed to estimate quantitative parameters of the apparent diffusion coefficient (ADC) model and intra-voxel incoherent motion (IVIM) model. Parameter estimation accuracy, precision and overall error were evaluated in terms of bias, variance and root mean squared error and compared against the MSE loss over a range of SNRs (5 - 30). Results: Networks trained with NLR loss show higher estimation accuracy than MSE for the ADC and IVIM diffusion coefficients as SNR decreases, with minimal loss of precision or total error. At high effective SNR (high SNR and small diffusion coefficients), both losses show comparable accuracy and precision for all parameters of both models. Conclusion: The proposed NLR loss is numerically stable and accurate across the full range of tested SNRs and improves parameter estimation accuracy of diffusion coefficients using self-supervised deep learning. We expect the development to benefit quantitative MR imaging techniques broadly, enabling more accurate parameter estimation from noisy data., Comment: 16 pages, 6 figures

Published
2023

3. How to Promote Student Teachers' Research Knowledge and Skills Online

Author

Schröder, Anna Isabel, Cammann, Franca, Darge, Kerstin, Krepf, Matthias, Weyers, Jonas, and König, Johannes

Abstract

Promoting research knowledge and skills (RKS) is an important task of teacher training programmes. One way of fostering RKS is through research-based learning (RBL). However, student teachers often struggle with the acquisition of RKS and do not benefit from RBL like students of other study programmes. This paper suggests e-learning as one part of the solution to support the design of courses that prepare students for conducting research projects. We present an interactive e-learning module designed to develop student teachers' RKS and analyse the effectiveness of (1) the e-learning module, (2) its combination with online instruction and (3) online instruction only. Unlike previous research, we assessed the development of student teachers' RKS (n = 402) using a standardised test. Findings revealed that both e-learning formats were effective in developing students' RKS. Moreover, the study provided evidence of the sustainability of learning gains obtained through the e-learning module. Both e-learning formats proved superior to online instruction only, which in turn did not promote students' RKS significantly, regardless of whether the course taught research methods explicitly or dealt with the contents of research. Thus, the development of further e-learning opportunities in the context of RBL should receive more attention in the future.

Published
2023
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4. Methods for change-point detection with additional interpretability

Author

Schröder, Anna Louise

Subjects
519.5, HA Statistics
Abstract

The main purpose of this dissertation is to introduce and critically assess some novel statistical methods for change-point detection that help better understand the nature of processes underlying observable time series. First, we advocate the use of change-point detection for local trend estimation in financial return data and propose a new approach developed to capture the oscillatory behaviour of financial returns around piecewise-constant trend functions. Core of the method is a data-adaptive hierarchically-ordered basis of Unbalanced Haar vectors which decomposes the piecewise-constant trend underlying observed daily returns into a binary-tree structure of one-step constant functions. We illustrate how this framework can provide a new perspective for the interpretation of change points in financial returns. Moreover, the approach yields a family of forecasting operators for financial return series which can be adjusted flexibly depending on the forecast horizon or the loss function. Second, we discuss change-point detection under model misspecification, focusing in particular on normally distributed data with changing mean and variance. We argue that ignoring the presence of changes in mean or variance when testing for changes in, respectively, variance or mean, can affect the application of statistical methods negatively. After illustrating the difficulties arising from this kind of model misspecification we propose a new method to address these using sequential testing on intervals with varying length and show in a simulation study how this approach compares to competitors in mixed-change situations. The third contribution of this thesis is a data-adaptive procedure to evaluate EEG data, which can improve the understanding of an epileptic seizure recording. This change-point detection method characterizes the evolution of frequencyspecific energy as measured on the human scalp. It provides new insights to this high dimensional high frequency data and has attractive computational and scalability features. In addition to contrasting our method with existing approaches, we analyse and interpret the method’s output in the application to a seizure data set.

Published
2016

5. The maximal subgroups of the classical groups in dimension 13, 14 and 15

Author

Schröder, Anna Katharina and Roney-Dougal, Colva Mary

Subjects
512, Group theory, Classical groups, Classification of finite simple groups, Maximal subgroups
Abstract

One might easily argue that the Classification of Finite Simple Groups is one of the most important theorems of group theory. Given that any finite group can be deconstructed into its simple composition factors, it is of great importance to have a detailed knowledge of the structure of finite simple groups. One of the classes of finite groups that appear in the classification theorem are the simple classical groups, which are matrix groups preserving some form. This thesis will shed some new light on almost simple classical groups in dimension 13, 14 and 15. In particular we will determine their maximal subgroups. We will build on the results by Bray, Holt, and Roney-Dougal who calculated the maximal subgroups of all almost simple finite classical groups in dimension less than 12. Furthermore, Aschbacher proved that the maximal subgroups of almost simple classical groups lie in nine classes. The maximal subgroups in the first eight classes, i.e. the subgroups of geometric type, were determined by Kleidman and Liebeck for dimension greater than 13. Therefore this thesis concentrates on the ninth class of Aschbacher's Theorem. This class roughly consists of subgroups which are almost simple modulo scalars and do not preserve a geometric structure. As our final result we will give tables containing all maximal subgroups of almost simple classical groups in dimension 13, 14 and 15.

Published
2015

9. Decision regret in breast cancer patients after adjuvant radiotherapy

Author

Köksal, Mümtaz, primary, Hoppe, Clara, additional, Schröder, Anna-Katharina, additional, Scafa, Davide, additional, Koch, David, additional, Sarria, Gustavo R., additional, Leitzen, Christina, additional, Abramian, Alina, additional, Kaiser, Christina, additional, Faridi, Andree, additional, Henkenberens, Christoph, additional, Schmeel, Leonard C., additional, and Giordano, Frank A., additional

Published
2023
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10. Beschriftete Bronzewaffen der Früh-und Mittelbronzezeit

Author

Schröder, Anna Maria

Subjects
Alte Geschichte, Vor- und Frühgeschichte, Archäologie, Classical Archaeology [FKA], Greece (Antiquity) [R938], Copper- and Bronze Age [T930.15]
Abstract

Die vorliegende Magisterarbeit befasst sich mit den beschrifteten Bronzewaffen der Früh- und Mittelbronzezeit (3. bis Mitte 2. Jahrtausend v. Chr.) aus dem Gebiet des Vorderen Orients. Dabei werden hauptsächlich die mit Keilschriftzeichen beschrifteten Waffen näher untersucht und zusammengefasst. Die Waffen wurden nach folgenden Gesichtspunkten untersucht; gab es bei der Beschriftung der Stücke bspw. besondere Moden oder „Trends“ für die verschiedenen Zeiten oder Regionen, wurde eine Waffen- und/ oder Inschriftengattung bei der Beschriftung anderen vorgezogen, wandelte sich die Sitte Waffen zu beschriften mit der Zeit und in den einzelnen Epochen, von wem und warum wurden Waffen beschriftet, welche Vorgänger gab es, taucht die Sitte überall gleichzeitig auf oder verbreitete sie sich von einer Region in die anderen, zu welcher Zeit waren welche Waffen beliebt und korreliert dies mit deren Benutzungsphasen, wurden einfache oder eher sog. Prunkwaffen für die Beschriftung genutzt, finden sich in den Nachbarregionen ähnliche Beispiele und hört die Sitte mit dem Aufkommen von Eisen als Werkstoff auf oder wird sie weiter tradiert bzw. für die Eisenwaffen übernommen? Dazu wurden sämtliche bis 2012 in Textsammlungen, Publikationen, Ausstellungskatalogen und Zeitschriften publizierte Waffen der Früh- und Mittelbronzezeit in einem Katalog aufgenommen und anschließend ausgewertet. In der Arbeit wird sich zeigen, dass der Anteil an beschrifteten Waffen im Vergleich zu anderen Objektgruppen gering war, da unter anderem die verschiedenen Metalle erst aus z.B. der Türkei oder dem Iran importiert werden mussten, was sie wiederum zu kostspieligen Materialien machte. So sind auch beschriftete Waffen eher als eine Art Luxusgut anzusehen, welche vor allem von den Eliten der jeweiligen Zeit in Gebrauch waren.

Published
2023
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13. Getting in Touch With Seaweed : Exploring a Non-Exploitative Relationship With a More-Than-Human Actor Through Design Research

Author

Schröder, Anna Marie and Schröder, Anna Marie

Abstract

Through human over-exploitation of nature, more and more ocean species approach ecological tipping points. On the other hand, more and more people suffer from climate anxiety. This thesis study explored an alternative relationship between humans and marine seaweed species through design research. Situated in posthumanist design, affirmative ethics, and kinship relations, the study experimented with non-exploitative human-seaweed encounters to stimulate reflection on the predominant perception of ocean species as resources for human use. By drifting through five design experiments, the study first investigated the current human- seaweed relationship at Ribersborg beach in Malmö and then invited participants to encounter seaweed from different perspectives in several interactive workshops. As the research study swayed through several threads of theory and practice, it found a prevalent distant stance towards seaweed. While participants who engaged in attentive interaction with seaweed showed an increased curiosity for the often- overlooked species group, the study found that an interdependency between humans and seaweed was either not perceived or negatively associated. Designerly speculation led to a performance of kinship rituals to encounter this vulnerability, which allowed room for reflection on current and future ways of being with seaweed in non-exploitative ways. The trialed practices of affirmative ethics involved human participants in coming up with these practices, which is of meaning in the further search for restoring the human relationship to nature through design.

Published
2022

15. Unboxing the Algorithm : Designing an Understandable Algorithmic Experience in Music Recommender Systems

Author

Schröder, Anna Marie and Ghajargar, Maliheh

Subjects
transparency, Datorsystem, machine learning, Design, Interaction design, music recommendation systems, Computer Systems, Human-centered computing, Empirical studies in interaction design, algorithmic experience, Human Computer Interaction, Människa-datorinteraktion (interaktionsdesign), explainable AI
Abstract

After decades of the existence of algorithms in everyday use technologies, users have developed an algorithmic awareness, but they still lack the confidence to grasp them. This study explores how understandability as a principle drawn from sociology, design, and computing can enhance the algorithmic experience in music recommendation systems. The preliminary results of this Research-Through-Design showed that users had limited mental models so far but had a curiosity to learn. Further, it confirmed that explanations as a dialogue could improve the algorithmic experience in music recommendation systems. Users could comprehend recommendations the best when they were easy to access and understand, directly related to user behavior, and when they allowed the user to correct the algorithm. To conclude, our study reconfirms that designing experiences that help users to understand the algorithmic workings will make authentic recommendations from intelligent systems more applicable in the long run.

Published
2021

16. Unboxing The Algorithm : Understandability And Algorithmic Experience In Intelligent Music Recommendation Systems

Author

Schröder, Anna Marie

Subjects
transparency, Systemvetenskap, informationssystem och informatik med samhällsvetenskaplig inriktning, machine learning, music recommendation systems, Interaction Technologies, interaction design, Information Systems, Social aspects, Interaktionsteknik, Tvärvetenskapliga studier inom samhällsvetenskap, algorithmic experience, Social Sciences Interdisciplinary, music streaming
Abstract

After decades of black-boxing the existence of algorithms in technologies of daily need, users lack confidence in handling them. This thesis study investigates the use situation of intelligent music recommendation systems and explores how understandability as a principle drawn from sociology, design, and computing can enhance the algorithmic experience. In a Research-Through-Design approach, the project conducted focus user sessions and an expert interview to explore first-hand insights. The analysis showed that users had limited mental models so far but brought curiosity to learn. Explorative prototyping revealed that explanations could improve the algorithmic experience in music recommendation systems. Users could comprehend information the best when it was easy to access and digest, directly related to user behavior, and gave control to correct the algorithm. Concluding, trusting users with more transparent handling of algorithmic workings might make authentic recommendations from intelligent systems applicable in the long run.

Published
2021

20. Left ventricular longitudinal contractility predicts acute‐on‐chronic liver failure development and mortality after transjugular intrahepatic portosystemic shunt

Author

Jansen, Christian, Schröder, Anna, Schueler, Robert, Lehmann, Jennifer, Praktiknjo, Michael, Uschner, Frank Erhard, Schierwagen, Robert, Thomas, Daniel, Monteiro, Sofia, Nickenig, Georg, Straßburg, Christian P., Meyer, Carsten, Arroyo, Vicente, Hammerstingl, Christoph, Trebicka, Jonel, Jansen, Christian, Schröder, Anna, Schueler, Robert, Lehmann, Jennifer, Praktiknjo, Michael, Uschner, Frank Erhard, Schierwagen, Robert, Thomas, Daniel, Monteiro, Sofia, Nickenig, Georg, Straßburg, Christian P., Meyer, Carsten, Arroyo, Vicente, Hammerstingl, Christoph, and Trebicka, Jonel

Abstract

Acute deterioration of liver cirrhosis (e.g., infections, acute‐on‐chronic liver failure [ACLF]) requires an increase in cardiac contractility. The insufficiency to respond to these situations could be deleterious. Left ventricular global longitudinal strain (LV‐GLS) has been shown to reflect left cardiac contractility in cirrhosis better than other parameters and might bear prognostic value. Therefore, this retrospective study investigated the role of LV‐GLS in the outcome after transjugular intrahepatic portosystemic shunt (TIPS) and the development of ACLF. We included 114 patients (48 female patients) from the Noninvasive Evaluation Program for TIPS and Their Follow‐Up Network (NEPTUN) cohort. This number provided sufficient quality and structured follow‐up with the possibility of calculating major scores (Child, Model for End‐Stage Liver Disease [MELD], Chronic Liver Failure Consortium acute decompensation [CLIF‐C AD] scores) and recording of the events (development of decompensation episode and ACLF). We analyzed the association of LV‐GLS with overall mortality and development of ACLF in patients with TIPS. LV‐GLS was independently associated with overall mortality (hazard ratio [HR], 1.123; 95% confidence interval [CI],1.010‐1.250) together with aspartate aminotransferase (HR, 1.009; 95% CI, 1.004‐1.014) and CLIF‐C AD score (HR, 1.080; 95% CI, 1.018‐1.137). Area under the receiver operating characteristic curve (AUROC) analysis for LV‐GLS for overall survival showed higher area under the curve (AUC) than MELD and CLIF‐C AD scores (AUC, 0.688 versus 0.646 and 0.573, respectively). The best AUROC‐determined LV‐GLS cutoff was −16.6% to identify patients with a significantly worse outcome after TIPS at 3 months, 6 months, and overall. LV‐GLS was independently associated with development of ACLF (HR, 1.613; 95% CI, 1.025‐2.540) together with a MELD score above 15 (HR, 2.222; 95% CI, 1.400‐3.528). Conclusion: LV‐GLS is useful for identifying patients at risk of dev

Published
2019

21. Investigation of factors influencing weight and survival after gastrectomy due to a gastric carcinoma

Author

Schröder, Anna, Martignoni, Marc (Prof. Dr.), and Friess, Helmut (Prof. Dr.)

Subjects
Medizin und Gesundheit, gastrectomy, gastric carcinoma, weight loss, survival, ddc:610, Gastrektomie, Magenkarzinom, Gewichtsabnahme, Überleben
Abstract

Das Magenkarzinom stellt eine der häufigsten Todesursache weltweit dar, dessen Diagnose meist spät erfolgt, was zur Folge hat, dass häufig schon fortgeschrittene Stadien vorliegen und somit eine schlechtere Prognose. Ziel dieser Dissertation war es, wichtige Faktoren zu ermitteln, die einen Einfluss auf die postoperative Gewichtabnahme und Überleben der Patienten mit Magenkarzinom haben. Prognostische Faktoren, die einen Einfluss auf das Überleben haben, sind Alter, Tumorstadium, Operationsradikalität, Fernmetastasen und Lymphknotenbefall. Das Gewicht wurde von keinem der Faktoren negativ beeinflusst. Gastric cancer is one of the leading causes of cancer death worldwide. Usually diagnosis of gastric cancer happens very late. Therefore an advanced stage is presented to the patients. Overall prognosis is poor for these patients. Aim of the dissertation was to evaluate the causes of weight loss and survival of patients with gastric cancer after surgery. Criteria with influence on the survival are age, tumor stage, radical surgery, metastasis, lymph node invasion. None of the given criteria had influenced the weight loss.

Published
2018

23. Left Ventricular Longitudinal Contractility Predicts Acute‐on‐Chronic Liver Failure Development and Mortality After Transjugular Intrahepatic Portosystemic Shunt

Author

Jansen, Christian, primary, Schröder, Anna, additional, Schueler, Robert, additional, Lehmann, Jennifer, additional, Praktiknjo, Michael, additional, Uschner, Frank E., additional, Schierwagen, Robert, additional, Thomas, Daniel, additional, Monteiro, Sofia, additional, Nickenig, Georg, additional, Strassburg, Christian P., additional, Meyer, Carsten, additional, Arroyo, Vicente, additional, Hammerstingl, Christoph, additional, and Trebicka, Jonel, additional

Published
2019
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24. Untersuchung von Einflussfaktoren auf Gewicht und Überleben nach Magenresektion aufgrund eines Magenkarzinoms

Author

Friess, Helmut (Prof. Dr.), Martignoni, Marc (Prof. Dr.), Schröder, Anna, Friess, Helmut (Prof. Dr.), Martignoni, Marc (Prof. Dr.), and Schröder, Anna

Abstract

Das Magenkarzinom stellt eine der häufigsten Todesursache weltweit dar, dessen Diagnose meist spät erfolgt, was zur Folge hat, dass häufig schon fortgeschrittene Stadien vorliegen und somit eine schlechtere Prognose. Ziel dieser Dissertation war es, wichtige Faktoren zu ermitteln, die einen Einfluss auf die postoperative Gewichtabnahme und Überleben der Patienten mit Magenkarzinom haben. Prognostische Faktoren, die einen Einfluss auf das Überleben haben, sind Alter, Tumorstadium, Operationsradikalität, Fernmetastasen und Lymphknotenbefall. Das Gewicht wurde von keinem der Faktoren negativ beeinflusst., Gastric cancer is one of the leading causes of cancer death worldwide. Usually diagnosis of gastric cancer happens very late. Therefore an advanced stage is presented to the patients. Overall prognosis is poor for these patients. Aim of the dissertation was to evaluate the causes of weight loss and survival of patients with gastric cancer after surgery. Criteria with influence on the survival are age, tumor stage, radical surgery, metastasis, lymph node invasion. None of the given criteria had influenced the weight loss.

Published
2018

25. Untersuchung von Einflussfaktoren auf Gewicht und Überleben nach Magenresektion aufgrund eines Magenkarzinoms

Author

Martignoni, Marc (Prof. Dr.), Martignoni, Marc (Prof. Dr.);Friess, Helmut (Prof. Dr.), Schröder, Anna, Martignoni, Marc (Prof. Dr.), Martignoni, Marc (Prof. Dr.);Friess, Helmut (Prof. Dr.), and Schröder, Anna

Abstract

Das Magenkarzinom stellt eine der häufigsten Todesursache weltweit dar, dessen Diagnose meist spät erfolgt, was zur Folge hat, dass häufig schon fortgeschrittene Stadien vorliegen und somit eine schlechtere Prognose. Ziel dieser Dissertation war es, wichtige Faktoren zu ermitteln, die einen Einfluss auf die postoperative Gewichtabnahme und Überleben der Patienten mit Magenkarzinom haben. Prognostische Faktoren, die einen Einfluss auf das Überleben haben, sind Alter, Tumorstadium, Operationsradikalität, Fernmetastasen und Lymphknotenbefall. Das Gewicht wurde von keinem der Faktoren negativ beeinflusst., Gastric cancer is one of the leading causes of cancer death worldwide. Usually diagnosis of gastric cancer happens very late. Therefore an advanced stage is presented to the patients. Overall prognosis is poor for these patients. Aim of the dissertation was to evaluate the causes of weight loss and survival of patients with gastric cancer after surgery. Criteria with influence on the survival are age, tumor stage, radical surgery, metastasis, lymph node invasion. None of the given criteria had influenced the weight loss.

Published
2018

26. Wie Feindbilder entstehen. Eine Theorie religiöser und ethnischer Konflikte

Author

Schröder, Anna-Konstanze

Abstract

Der Ethnologe Günther Schlee erklärt in seinem gleichnamigen Buch in vier Teilen, »wie Feindbilder entstehen«. Es ist eine Aufsatzsammlung aus Vortragstexten, die in mehreren Jahren entstanden sind. Darin verknüpft Schlee Theorien des Rational-Choice-Paradigmas geschickt mit denen der Sozialstrukturanalyse und diskutiert sie im Rahmen seiner Fragestellung zu Konflikten zwischen verschiedenen Ethnien oder Religionen. Schlees Thema ist eine wissenschaftliche Entgegnung auf die landläufige Mein...

Published
2017

29. Auditor independence : A quantitative study of the auditors perceived pressure and audit committees' impact on perceived pressure

Author

Jangenfeldt, Andreas and Schröder, Anna

Subjects
Press, Audit Committee, Auditor, Revisionsutskott, Pressure, Independence, Borg CR100 (centiMax) Scale®, Revisor, Oberoende, Business Administration, Företagsekonomi
Abstract

Syfte: Vårt första delsyfte med den här studien är att undersöka om press är ett hot mot revisorns oberoende genom att undersöka om det är skillnad på den press revisorer upplever och den press de bedömer att de klarar av. Vårt andra delsyfte är att redogöra för hur och i vilken omfattning ett revisionsutskotts existens kan sänka revisorns upplevda press och därmed stärka revisorns oberoende. Metod: Denna studie är utförd med kvantitativ metod. Data har samlats in med hjälp av dataenkäter som har skickats via e-post till 316 revisorer i Sverige som arbetar med noterade bolag. Revisorerna har skattat sin upplevda press från klienterna med hjälp av Borg CR100 (centiMax) Scale®. Analys av data har utförts med korrelationsanalys, regressionsanalys och t-test med hjälp av statistikprogrammet SPSS. Resultat & slutsats: Vi fann signifikant skillnad mellan den press revisorerna upplever och den press revisorerna bedömer att de skulle klara av innan de godkänner en felaktig finansiell rapport. Studien indikerar en liten skillnad i upplevd press vid revision av företag med revisionsutskott jämfört med revision av företag utan revisionsutskott. Dock var denna skillnad inte signifikant. Förslag till fortsatt forskning: I kapitel 5.5 tar vi upp förslag till fortsatt forskning varvid huvudfrågorna vi diskuterar är följande: hur sammansättningen av revisionsutskotten påverkar revisionsutskottens effektivitet, vad som orsakar de stora skillnaderna i huruvida revisorerna upplever press eller inte från VD och styrelse och hur hälsan påverkas av den press revisorerna bedömer att de upplever. Uppsatsens bidrag: Uppsatsen bidrar med empiriskt underlag för fortsatt forskning då denna studie är den första i sitt slag som har utförts i Sverige. Vidare bidrar studien praktiskt till en ökad kunskap om hur mycket press en revisor upplever i förhållande till vad en revisor bedömer att de klarar av samt hur revisionsutskott påverkar revisorns upplevda press. Aim: Our first subsidiary aim of this study is to investigate whether the pressure is a threat to auditor's independence by investigating whether there is a difference between the pressure experienced by auditors and the pressures they estimate that they can handle. Our second subsidiary aim is to explain how and to what extent an audit committees' existence can lower the auditor's perceived pressure and thereby strengthen the auditor's independence. Method: This study is conducted by a quantitative method. Data were collected using data questionnaires sent by e - mail to 316 auditors in Sweden working with listed companies. The auditor has estimated his or hers perceived pressure from clients using the Borg CR100 (centiMax) Scale®. Data analysis has been performed by correlation analysis, regression analysis, and t-test with the statistical program SPSS. Result & Conclusions: We found a significant difference between the experienced pressure by auditors and the pressure auditors estimated that they could handle before approving a false financial report. The study indicates a small difference in the perceived pressure for audits in co-operation with companies with audit committees, compared with companies without audit committees. However, the difference was not significant. Suggestions for further research: In Chapter 5.5 we bring up suggestions for further research and the main issues we discuss are: how the composition of audit committees influences audit committees' effectiveness, what the large differences in whether the auditors are experiencing pressure or not from the President and Board of the company are caused by and how the health is affected by the estimated pressure auditors experiencing. Contribution of the thesis: The study contributes with the empirical foundation for continued research because this study is the first of its kind in Sweden. Furthermore, the study contributes practically to a greater knowledge of how much pressure an accountant experience in relation to what the auditor believes that they are capable of and how audit committees affect the auditor's perceived pressure.

Published
2016

31. t-BuOOH induces ferroptosis in human and murine cell lines

Author

Wenz, Christine, primary, Faust, Dagmar, additional, Linz, Berenike, additional, Turmann, Christian, additional, Nikolova, Teodora, additional, Bertin, John, additional, Gough, Peter, additional, Wipf, Peter, additional, Schröder, Anna Sophia, additional, Krautwald, Stefan, additional, and Dietrich, Cornelia, additional

Published
2017
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34. Prognostischer Nutzen des kardialen Biomarkers MR-pro-ADM zur Abschätzung der Rezidivwahrscheinlichkeit nach RF-Katheterablation bei Vorhofflimmern

Author

Schröder, Anna Izabela

Subjects
Adrenomedullin, catheter ablation, atrial fibrillation, 600 Technik, Medizin, angewandte Wissenschaften::610 Medizin und Gesundheit, MR-pro-ADM
Abstract

Einleitung Vorhofflimmern ist die häufigste, anhaltende Rhythmusstörung des Menschen. Es ist mit vielen, zum Teil schwerwiegenden Komplikationen verbunden. Die Katheterablation stellt ein kuratives Verfahren dar, welches jedoch mit einer hohen Rezidivrate vergesellschaftet ist. Für den kardiale Biomarker Adrenomedullin beziehungsweise seinem inaktiven Spaltprodukt MR-pro- ADM konnte bereits ein prognostischer Nutzen für zahlreiche Erkrankungen gezeigt werden. Erhöhte Plasmawerte Adrenomedullins finden sich bei kardiovaskulären Erkrankungen, die mit ischämischen oder hypoxischen Zuständen einhergehen. Das Ziel der vorliegenden Arbeit war es zu evaluieren, ob Adrenomedullin einen prädiktiven Nutzen hinsichtlich des Auftretens eines Vorhofflimmerrezidivs in einem Zeitraum von 12 Monaten nach RF-Ablation hat. Methodik Wir bestimmten die Plasma-MR-pro-ADM-Konzentration von 87 Patienten am Tag vor geplanter RF-Ablation sowie 12 Monate hiernach. Die Messung erfolgte mittels einer direkten Chemilumineszenz-Messung. Die Analyse zwischen der Höhe des gemessenen MR-pro-ADM-Spiegels sowie dem Vorliegen eines Vorhofflimmerrezidivs nach 12 Monaten erfolgte mithilfe einer univariaten sowie multivariaten Regressionsanalyse. Ergebnisse Alle 87 eingeschlossenen Patienten erhielten eine erfolgreiche RF-Ablation. Im Gesamtkollektiv befanden sich 54% Patienten mit paroxysmalem Vorhofflimmern. Die mittlere linksventrikuläre Ejektionsfraktion betrug 54% (±25%), der mittlere linksatriale Durchmesser 44 mm (±7). 12 Monate nach erfolgter RF-Ablation wiesen 29 % der Patienten ein Vorhofflimmerrezidiv auf. Die MR-pro-ADM- Plasmakonzentration gemessen im Gesamtkollektivs betrug vor Ablation 0,72 nmol/l (±0,22) sowie nach Ablauf des Beobachtungszeitraums 0,63 nmol/l (±0,24). Innerhalb der Patientenuntergruppe mit einem Vorhofflimmerrezidiv nach 12 Monaten zeigte sich ein mittlerer basaler MR-pro-ADM-Plasmaspiegel von 0,89 nmol/l (±0,29), bei denjenigen ohne Vorhofflimmerrezidiv von 0,65 nmol/l (±0,14), p < 0,001. Nach 12 Monaten lag der mittlere MR-pro-ADM-Plasmaspiegel bei den Patienten mit Vorhofflimmerrezidiv bei 0,81 nmol/l (±0,22) sowie bei denjenigen ohne Vorhofllimmerrezidiv bei 0,54 nmol/l (±0,20); p < 0,001. Eine auf Grundlage dieser Ergebnisse berechnete ROC-Kurve zeigte für einen Cut-off- Wert von 0,82 nmol/l eine Spezifität von 98 % sowie eine Sensitivität von 64 %, um ein Vorhofflimmerrezidiv nach erfolgter Katheterablation voraussagen zu können. Darüber hinaus zeigten sich statistisch signifikante Unterschiede zwischen den beiden Untergruppen hinsichtlich der linksventrikulären Ejektionsfraktion, dem linksatrialen Durchmesser sowie der Höhe des NT-pro- BNPs. In einer multivariaten Regressionsanalyse zeigte sich lediglich für die Höhe des MR-pro-ADMs ein unabhängiger prädiktiver Nutzen. Schlussfolgerung In unserer Beobachtungsstudie wird zum ersten Mal gezeigt, dass die Höhe des MR- pro-AMDs ein unabhängiger Prädiktor für die Rezidivwahrscheinlichkeit von Vorhofflimmern in einem Zeitraum von 12 Monaten nach Katheterablation ist. Der kardiale Biomarker MR-pro-ADM könnte helfen, die Patientenselektion zu optimieren. Es sind weitere Studien mit größeren Patientenkollektiven notwendig, um diese Ergebnisse zu bestätigen., Background Atrial fibrillation is the most common sustained arrhythmia. It is associated with a high morbidity and mortality. Catheter ablation is a curative therapy which has nevertheless a high recurrence rate. The cardiac biomarker Adrenomedullin and its inactive precursor MR-pro-ADM have been investigated in previous studies. It has been shown that they are elevated in multiple diseases affecting the cardiovascular system related to tissue hypoxia and ischemia with plasma levels reflecting the level of disease severity. In this study we evaluated the prognostic value of MR-pro-ADM in patients undergoing ablation of atrial fibrillation. Methods Plasma concentrations of MR-pro-ADM were measured in 87 patients undergoing radiofrequency ablation at baseline and 12 months thereafter. The measurement was done using direct chemiluminescence. The association between plasma levels of MR-pro-ADM and recurrence of atrial fibrillation was performed using cox regression analysis. Results Radiofrequency ablation was performed successfully in all 87 patients. In total 54 % of the patients had paroxysmal atrial fibrillation. The mean left ventricular ejection fraction was 54 % (±25%), the mean left atrial diameter was 44 mm (±7). 12 months after the ablation 29 % of the patients presented with a recurrence. At baseline the mean plasma concentration of MR-pro-ADM in the total population was 0,72 nmol/l (±0,22) and 0,63 nmol/l (±0,24) 12 months thereafter. Patients with a recurrence after 12 months had baseline MR-pro-ADM levels of 0,89 nmol/l (±0,29) compared to the patients free of atrial fibrillation with a baseline MR-pro-ADM of 0,65 nmol/l (±0,14) , p < 0.001. After 12 months MR-pro-ADM- plasma-levels were 0,81 nmol/l (±0,22) within the group with a recurrence compared to 0,54 nmol/l (±0,20); p < 0,001 within the subgroup free of recurrence. Based on these values a ROC curve analysis was performed which showed an optimal cut-off value for MR-pro-ADM of 0,82 nmol/l to predict recurrence after ablation with a sensititvity of 64 % and a specificity of 98 %. There were significant differences between the two groups concerning left ventricular ejection fraction, left atrial diameter and NT-pro-BNP-plasma levels. After using multivariate logistic regression analysis MR-pro-ADM was the sole independent predictor of recurrence of atrial fibrillation in our population. Conclusion Our study is the first to demonstrate the predictive power of elevated plasma levels of MR-pro-ADM and recurrence of atrial fibrillation within 12 months after ablation. MR-pro-ADM may help to optimize patient selection for ablation. There are further studies needed to validate our findings.

Published
2015
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35. FreSpeD: Frequency-Specific Change-Point Detection in Epileptic Seizure Multi-Channel EEG Data.

Author

Schröder, Anna Louise and Ombao, Hernando

Subjects
*DIAGNOSIS of epilepsy, *ELECTROENCEPHALOGRAPHY, *CHANGE-point problems, *BRAIN, *ROBUST statistics
Abstract

The goal in this article is to develop a practical tool that identifies changes in the brain activity as recorded in electroencephalograms (EEG). Our method is devised to detect possibly subtle disruptions in normal brain functioning that precede the onset of an epileptic seizure. Moreover, it is able to capture the evolution of seizure spread from one region (or channel) to another. The proposed frequency-specific change-point detection method (FreSpeD) deploys a cumulative sum-type test statistic within a binary segmentation algorithm. We demonstrate the theoretical properties of FreSpeD and show its robustness to parameter choice and advantages against two competing methods. Furthermore, the FreSpeD method produces directly interpretable output. When applied to epileptic seizure EEG data, FreSpeD identifies the correct brain region as the focal point of seizure and the timing of the seizure onset. Moreover, FreSpeD detects changes in cross-coherence immediately before seizure onset which indicate an evolution leading up to the seizure. These changes are subtle and were not captured by the methods that previously analyzed the same EEG data. Supplementary materials for this article are available online. [ABSTRACT FROM AUTHOR]

Published
2019
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36. Revisorns oberoende : En kvantitativ studie av revisorers upplevda press och revisionsutskotts inverkan på upplevd press

Author

Jangenfeldt, Andreas, Schröder, Anna, Jangenfeldt, Andreas, and Schröder, Anna

Abstract

Syfte: Vårt första delsyfte med den här studien är att undersöka om press är ett hot mot revisorns oberoende genom att undersöka om det är skillnad på den press revisorer upplever och den press de bedömer att de klarar av. Vårt andra delsyfte är att redogöra för hur och i vilken omfattning ett revisionsutskotts existens kan sänka revisorns upplevda press och därmed stärka revisorns oberoende. Metod: Denna studie är utförd med kvantitativ metod. Data har samlats in med hjälp av dataenkäter som har skickats via e-post till 316 revisorer i Sverige som arbetar med noterade bolag. Revisorerna har skattat sin upplevda press från klienterna med hjälp av Borg CR100 (centiMax) Scale®. Analys av data har utförts med korrelationsanalys, regressionsanalys och t-test med hjälp av statistikprogrammet SPSS. Resultat & slutsats: Vi fann signifikant skillnad mellan den press revisorerna upplever och den press revisorerna bedömer att de skulle klara av innan de godkänner en felaktig finansiell rapport. Studien indikerar en liten skillnad i upplevd press vid revision av företag med revisionsutskott jämfört med revision av företag utan revisionsutskott. Dock var denna skillnad inte signifikant. Förslag till fortsatt forskning: I kapitel 5.5 tar vi upp förslag till fortsatt forskning varvid huvudfrågorna vi diskuterar är följande: hur sammansättningen av revisionsutskotten påverkar revisionsutskottens effektivitet, vad som orsakar de stora skillnaderna i huruvida revisorerna upplever press eller inte från VD och styrelse och hur hälsan påverkas av den press revisorerna bedömer att de upplever. Uppsatsens bidrag: Uppsatsen bidrar med empiriskt underlag för fortsatt forskning då denna studie är den första i sitt slag som har utförts i Sverige. Vidare bidrar studien praktiskt till en ökad kunskap om hur mycket press en revisor upplever i förhållande till vad en revisor bedömer att de klarar av samt hur revisionsutskott påverkar revisorns upplevda press., Aim: Our first subsidiary aim of this study is to investigate whether the pressure is a threat to auditor's independence by investigating whether there is a difference between the pressure experienced by auditors and the pressures they estimate that they can handle. Our second subsidiary aim is to explain how and to what extent an audit committees' existence can lower the auditor's perceived pressure and thereby strengthen the auditor's independence. Method: This study is conducted by a quantitative method. Data were collected using data questionnaires sent by e - mail to 316 auditors in Sweden working with listed companies. The auditor has estimated his or hers perceived pressure from clients using the Borg CR100 (centiMax) Scale®. Data analysis has been performed by correlation analysis, regression analysis, and t-test with the statistical program SPSS. Result & Conclusions: We found a significant difference between the experienced pressure by auditors and the pressure auditors estimated that they could handle before approving a false financial report. The study indicates a small difference in the perceived pressure for audits in co-operation with companies with audit committees, compared with companies without audit committees. However, the difference was not significant. Suggestions for further research: In Chapter 5.5 we bring up suggestions for further research and the main issues we discuss are: how the composition of audit committees influences audit committees' effectiveness, what the large differences in whether the auditors are experiencing pressure or not from the President and Board of the company are caused by and how the health is affected by the estimated pressure auditors experiencing. Contribution of the thesis: The study contributes with the empirical foundation for continued research because this study is the first of its kind in Sweden. Furthermore, the study contributes practically to a greater knowledge of how much pressure an accountant e

Published
2016

38. <italic>t</italic>-BuOOH induces ferroptosis in human and murine cell lines.

Author

Wenz, Christine, Faust, Dagmar, Linz, Berenike, Turmann, Christian, Nikolova, Teodora, Bertin, John, Gough, Peter, Wipf, Peter, Schröder, Anna Sophia, Krautwald, Stefan, and Dietrich, Cornelia

Subjects
REACTIVE oxygen species, APOPTOSIS, HYDROGEN peroxide, CELL death, KERATINOCYTES, POLYMERASES
Abstract

Reactive oxygen species (ROS)-induced apoptosis has been extensively studied. Increasing evidence suggests that ROS, for instance, induced by hydrogen peroxide (H2O2), might also trigger regulated necrotic cell death pathways. Almost nothing is known about the cell death pathways triggered by tertiary-butyl hydroperoxide (t-BuOOH), a widely used inducer of oxidative stress. The lipid peroxidation products induced by t-BuOOH are involved in the pathophysiology of many diseases, such as cancer, cardiovascular diseases, or diabetes. In this study, we exposed murine fibroblasts (NIH3T3) or human keratinocytes (HaCaT) to t-BuOOH (50 or 200 μM, respectively) which induced a rapid necrotic cell death. Well-established regulators of cell death, i.e., p53, poly(ADP)ribose polymerase-1 (PARP-1), the stress kinases p38 and c-Jun N-terminal-kinases 1/2 (JNK1/2), or receptor-interacting serine/threonine protein kinase 1 (RIPK1) and 3 (RIPK3), were not required for t-BuOOH-mediated cell death. Using the selective inhibitors ferrostatin-1 (1 μM) and liproxstatin-1 (1 μM), we identified ferroptosis, a recently discovered cell death mechanism dependent on iron and lipid peroxidation, as the main cell death pathway. Accordingly, t-BuOOH exposure resulted in a ferrostatin-1- and liproxstatin-1-sensitive increase in lipid peroxidation and cytosolic ROS. Ferroptosis was executed independently from other t-BuOOH-mediated cellular damages, i.e., loss of mitochondrial membrane potential, DNA double-strand breaks, or replication block. H2O2 did not cause ferroptosis at equitoxic concentrations (300 μM) and induced a (1) lower and (2) ferrostatin-1- or liproxstatin-1-insensitive increase in lipid peroxidation. We identify that t-BuOOH and H2O2 produce a different pattern of lipid peroxidation, thereby leading to different cell death pathways and present t-BuOOH as a novel inducer of ferroptosis. [ABSTRACT FROM AUTHOR]

Published
2018
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39. Förpackningsdesign Inom Ett Exklusivt Segment

Author

Leksell, Jacob and Schröder, Anna

Subjects
Price positioning, Product differentiation, Kvalitet, Exclusivity, Quality, Prispositionering, Exklusivitet, Segmenting, Package design, Förpackningsdesign, Segmentering, Produktdifferentiering, Marknadsföring, Marketing
Abstract

The competition amongst companies is getting tougher and the economic markets are getting even bigger with new products and businesses. One way for companies to differentiate themselves from the competitors is through packaging design. If the merchandise is to send a reliable and solid message to consumers, the attributes of the packaging must be consistent and uniform. If the different attributes are not coherent, the message loses credibility towards the consumer. Through the sent messages, the pack signals the products’ expected quality and price. This paper includes two studies, in which the main objective is to discover and build understanding about Swedish consumers’ perception of a product’s price depending on the pack’s design. The focus of this paper is based upon household products. The first study is solely focused on consumers’ opinions on package design, while the second study is based on existing product packs on the market. The results obtained in the consumer study will discover eventual general opinions concerning cheap and expensive packages. These results will then be compared to a selection of products from the markets’ existing offers. The purpose of this study is to clarify how well companies shape their packs based on consumers’ general perception. It is finally discussed how the different attributes can be used to legitimize a higher or lower price. Konkurrensen mellan företag ökar och blir allt hårdare med ett ständigt växande antal aktörer på marknaden. Ett sätt att differentiera sig från konkurrenter är genom förpackningsdesign. För att varan i sin helhet ska ge ett pålitligt intryck måste förpackningens attribut vara enhetliga och genomgående. Spretar attributen inger detta förvirring och skapar brist i trovärdighet hos konsumenten. Förpackningen signalerar varans förväntade kvalitet och pris. Denna uppsats omfattar två studier med syfte att kartlägga svenska konsumenters uppfattning av en produkts pris utifrån förpackningens utformning. Fokus i denna uppsats ligger på hushållsprodukter. Den första studien vänder sig direkt till konsumenten medan den andra undersöker befintliga förpackningar på marknaden. Resultatet av konsumenternas generella uppfattning, gällande billiga respektive dyrare förpackningar, jämförs med ett urval från marknadens befintliga utbud. Detta görs med syfte att klargöra för hur väl företagen arbetar efter konsumenternas generella uppfattning. Slutligen diskuteras hur de olika attributen kan användas i förpackningsdesign för att legitimera ett dyrare respektive billigare pris.

Published
2012

40. Sjuksköterskans förhållningssätt i vården till patienter som genomgår inducerad abort : En litteraturstudie

Author

Lindblad, Sanna and Schröder, Anna

Subjects
Induced abortion, Omvårdnad, Obstetrics, Gynecology and Reproductive Medicine, Reproduktionsmedicin och gynekologi, Nurse attitude, Nursing, The Theory of Human Caring
Abstract

Theoretical framework: The Theory of Human Caring by Jean Watson was used as a theoretical framework. Aim: The aim of this literature review was to describe the attitude of nursing patients who go through an induced abortion, from a nurse perspective. Method: This literature review is based on a sample of nine qualitative and quantitative studies, collected in the databases Cinahl, PubMed and PsycInfo. The qualities of the studies were assessed through modified templates. Analysis of the results from the studies was inspired of a content analysis. Findings: The nurses experienced their work as meaningful since they give support to the patient. The nurses felt that their work was justified when the decision to have an abortion was well thought through and they felt respect towards the patient when they were aware of the patient’s circumstances. The nurses experienced stress and emotional impact when they faced ethical dilemmas and contradictions to abortion. Conclusion: Nurses experience can affect how patients experience care. Many nurses feel that they do not get enough support to handle difficult situations that they encounter in their work. Nurses who experience a high level of support in the workplace perceive tasks as less demanding what leads to better treatment.

Published
2011

41. Konversionserleben als Schnittpunkt der psychologischen und soziologischen Forschungsperspektive auf den Konversionsprozess: Ein religionspsychologischer Zugang für die Religionswissenschaft und eine neue Konversionstheorie

Author

Hase, Thomas, Seiwert, Hubert, Murken, Sebastian, Universität Leipzig, Schröder, Anna-Konstanze, Hase, Thomas, Seiwert, Hubert, Murken, Sebastian, Universität Leipzig, and Schröder, Anna-Konstanze

Abstract

Der Gegenstand dieser Dissertation sind Konversionsprozesse von Angehörigen der Evangelischen Landeskirchen in Deutschland (EKD); insbesondere geht es um die Art und Weise, wie Menschen die Veränderung ihrer Persönlichen Religion erleben. Die Theorie ist aus der religionssoziologischen, religionswissenschaftlichen und religionspsychologischen Konversionsforschung der letzten 100 Jahre abgeleitet und mittels quantitativer Verfahren geprüft worden. Drei Ergebnisse sind für die Arbeit zentral: 1. Anstatt Mitglieder devianter religiöser Gruppen zu befragen und die Motivlagen zur Mitgliedschaft zu erforschen, bilden Aussagen von Angehörigen der Evangelischen Kirchen in Deutschland die Datengrundlage. Auch bei ihnen ist nachweisbar, dass Konversionen zu biographischen Rekonstruktionen führen, die sich an der Norm der Religionsgemeinschaft orientieren. In der EKD ist das normative Spektrum breit, sodass hier Konversion sowohl als plötzliche (radikale) Veränderung als auch als gradueller Wandel sowie als unbewusster Prozess im Laufe der Biographie erlebt wird. 2. Über die biographische Rekonstruktion des Vorher-Nachher-Unterschieds der veränderten Persönlichen Religion hinaus sollten die Befragten angeben, als wie intensiv oder umfassend sie diese Veränderung erlebt haben. Anhand der Daten lässt sich zeigen, dass bei einem intensiveren Veränderungserleben auch die persönliche Religion zentraler für die Lebensvollzüge ist. 3. Die quantitativen Methoden haben es ermöglicht, sowohl die soziale Normzuordnung als auch das psychische Intensivierungserleben in ihrer Bedeutsamkeit für die Erklärung von Konversionsprozessen zu vergleichen. Beide Zugänge ergänzen einander in Abhängigkeit der Fragestellung: Die Zuordnung zur sozial normierten Erlebensweise der Konversion ist der stärkere Prädiktor für die biographsiche Rekonstruktion, die erlebte Intensität der Verändung ist der stärkere Prädiktor für den Zentralität der Persönlichen Religion (außer für den seltenen plötzlichen Konver

Published
2014

42. Konversionserleben als Schnittpunkt der psychologischen und soziologischen Forschungsperspektive auf den Konversionsprozess: Ein religionspsychologischer Zugang für die Religionswissenschaft und eine neue Konversionstheorie

Author

Seiwert, Hubert, Murken, Sebastian, Universität Leipzig, Schröder, Anna-Konstanze, Seiwert, Hubert, Murken, Sebastian, Universität Leipzig, and Schröder, Anna-Konstanze

Abstract

Der Gegenstand dieser Dissertation sind Konversionsprozesse von Angehörigen der Evangelischen Landeskirchen in Deutschland (EKD); insbesondere geht es um die Art und Weise, wie Menschen die Veränderung ihrer Persönlichen Religion erleben. Die Theorie ist aus der religionssoziologischen, religionswissenschaftlichen und religionspsychologischen Konversionsforschung der letzten 100 Jahre abgeleitet und mittels quantitativer Verfahren geprüft worden. Drei Ergebnisse sind für die Arbeit zentral: 1. Anstatt Mitglieder devianter religiöser Gruppen zu befragen und die Motivlagen zur Mitgliedschaft zu erforschen, bilden Aussagen von Angehörigen der Evangelischen Kirchen in Deutschland die Datengrundlage. Auch bei ihnen ist nachweisbar, dass Konversionen zu biographischen Rekonstruktionen führen, die sich an der Norm der Religionsgemeinschaft orientieren. In der EKD ist das normative Spektrum breit, sodass hier Konversion sowohl als plötzliche (radikale) Veränderung als auch als gradueller Wandel sowie als unbewusster Prozess im Laufe der Biographie erlebt wird. 2. Über die biographische Rekonstruktion des Vorher-Nachher-Unterschieds der veränderten Persönlichen Religion hinaus sollten die Befragten angeben, als wie intensiv oder umfassend sie diese Veränderung erlebt haben. Anhand der Daten lässt sich zeigen, dass bei einem intensiveren Veränderungserleben auch die persönliche Religion zentraler für die Lebensvollzüge ist. 3. Die quantitativen Methoden haben es ermöglicht, sowohl die soziale Normzuordnung als auch das psychische Intensivierungserleben in ihrer Bedeutsamkeit für die Erklärung von Konversionsprozessen zu vergleichen. Beide Zugänge ergänzen einander in Abhängigkeit der Fragestellung: Die Zuordnung zur sozial normierten Erlebensweise der Konversion ist der stärkere Prädiktor für die biographsiche Rekonstruktion, die erlebte Intensität der Verändung ist der stärkere Prädiktor für den Zentralität der Persönlichen Religion (außer für den seltenen plötzlichen Konver

Published
2014

44. Scientific versus intuitive entrepreneurial action: Antecedents and performance outcomes.

Author

Wesemann, Henrik, Schröder, Anna Paulina, Zellweger, Thomas Markus, and Souitaris, Vangelis

Abstract

Our study investigates the antecedents and performance consequences of scientific versus intuitive entrepreneurial action. Applying a mixed-method approach, we first use qualitative data from 50 interviews to develop a conceptual model that links the entrepreneurs' imprints--formative experiences in life with either positive or negative connotation--to the adopted entrepreneurial action (intuitive versus scientific), and finally to the venture's success. We then conduct a quantitative analysis with 233 ventures that tests and lends empirical support to the propositions derived in the qualitative study. We find that positive imprints are linked to intuitive action, which is related to limited venture success. In contrast, negative imprints are linked to scientific action, which is related to pronounced venture success. Our study contributes to the literatures on the micro-foundations of entrepreneurial action, new venture strategy, and imprinting theory. [ABSTRACT FROM AUTHOR]

Published
2023
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45. Influence of DPH1 and DPH5 Protein Variants on the Synthesis of Diphthamide, the Target of ADP-Ribosylating Toxins.

Author

Mayer, Klaus, Schröder, Anna, Schnitger, Jerome, Stahl, Sebastian, and Brinkmann, Ulrich

Subjects
*AMINO acid analysis, *ADP-ribosylation, *EUKARYOTIC cells, *ANTIBODY-toxin conjugates, *TOXIN analysis
Abstract

The diphthamide on eukaryotic translation elongation factor 2 (eEF2) is the target of ADP-ribosylating toxins and -derivatives that serve as payloads in targeted tumor therapy. Diphthamide is generated by seven DPH proteins; cells deficient in these (DPHko) lack diphthamide and are toxin-resistant. We have established assays to address the functionality of DPH1 (OVCA1) and DPH5 variants listed in dbSNP and cosmic databases: plasmids encoding wildtype and mutant DPHs were transfected into DPHko cells. Supplementation of DPH1 and DPH5 restores diphthamide synthesis and toxin sensitivity in DPH1ko and DPH5ko cells, respectively. Consequently, the determination of the diphthamide status of cells expressing DPH variants differentiates active and compromised proteins. The DPH1 frameshift variant L96fs* (with N-terminal 96 amino acids, truncated thereafter) and two splice isoforms lacking 80 or 140 amino acids at their N-termini failed to restore DPH1ko deficiency. The DPH1 frameshift variant R312fs* retained some residual activity even though it lacks a large C-terminal portion. DPH1 missense variants R27W and S56F retained activity while S221P had reduced activity, indicated by a decreased capability to restore diphthamide synthesis. The DPH5 nonsense or frameshift variants E60*, W136fs* and R207* (containing intact N-termini with truncations after 60, 136 or 207 amino acids, respectively) were inactive: none compensated the deficiency of DPH5ko cells. In contrast, missense variants D57G, G87R, S123C and Q170H as well as the frequently occurring DPH5 isoform delA212 retained activity. Sensitivity to ADP-ribosylating toxins and tumor-targeted immunotoxins depends on diphthamide which, in turn, requires DPH functionality. Because of that, DPH variants (in particular those that are functionally compromised) may serve as a biomarker and correlate with the efficacy of immunotoxin-based therapies. [ABSTRACT FROM AUTHOR]

Published
2017
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