Universitätspublikationen
Refine
Year of publication
- 2021 (3024) (remove)
Document Type
- Article (1852)
- Doctoral Thesis (245)
- Preprint (244)
- Part of Periodical (183)
- Contribution to a Periodical (152)
- Working Paper (133)
- Book (119)
- Review (45)
- Conference Proceeding (25)
- Bachelor Thesis (11)
- Master's Thesis (7)
- Report (5)
- Part of a Book (2)
- Other (1)
Language
Has Fulltext
- yes (3024) (remove)
Keywords
- COVID-19 (43)
- SARS-CoV-2 (39)
- inflammation (21)
- prostate cancer (14)
- aging (12)
- children (11)
- climate change (10)
- Cancer (9)
- Epilepsy (9)
- autophagy (9)
Institute
- Medizin (999)
- Physik (405)
- Präsidium (284)
- Wirtschaftswissenschaften (233)
- Biowissenschaften (204)
- Frankfurt Institute for Advanced Studies (FIAS) (172)
- Sustainable Architecture for Finance in Europe (SAFE) (158)
- Biochemie, Chemie und Pharmazie (154)
- Informatik (130)
- Psychologie und Sportwissenschaften (107)
Die diesjährige Inhaberin der Alfred-Grosser-Gastprofessur des Fachbereichs Gesellschaftswissenschaften, eine Kooperation mit der Stiftung Polytechnische Gesellschaft Frankfurt am Main, ist Prof. Dr. Astrid von Busekist, seit 2001 Professorin für Politische Theorie an der Sciences Po in Paris. Ihr stadtöffentlicher Vortrag mit dem Titel »Träume von Räumen. Exkurs über die Grenze« findet digital am Dienstag, 23. Februar 2021, um 19.00 Uhr c.t. statt.
Neuer Band der Reihe Frankfurter Beiträge zur Erziehungswissenschaft nimmt Adornos berühmten Radioessay als Ausgangs- und Bezugspunkt für vielfältige Interpretationen und Gegenwartsanalysen.
Rezension zu: Sabine Andresen, Dieter Nittel, Christiane Thompson (Hg.) Erziehung nach Auschwitz bis heute. Aufklärungsanspruch und Gesellschaftsanalyse. Frankfurter Beiträge zur Erziehungswissenschaft, Band 22, Goethe-Universität, FB 04, 2019
Neugründung: Buber-Rosenzweig-Institut als zentrale Forschungsstätte zum Judentum der Moderne
(2021)
Beobachten, untersuchen, experimentieren: Wie soll das gehen unter Pandemiebedingungen? Wenn auch die Chancen der digitalen Medien nun gezwungenermaßen zusehends sichtbar wurden, so sind gerade für angehende Biologielehrkräfte Primärerfahrungen mit originalen Organismen und das Einüben naturwissenschaftlicher Arbeitsmethoden sehr wichtig...
Einst war eine Filmvorführung ein flüchtiges Ereignis, das außer schönen Erinnerungen im Gedächtnis des Publikums keine Spuren hinterließ. Heute, im Zeitalter des Streaming, setzt jeder Film einen digitalen Fußabdruck im Reich der Daten. Und nicht nur das: Der Film selbst hat sich mit der digitalen Transformation grundlegend verändert und neue Formen und Formate entwickelt. Diese Umbrüche stellen das kleine Fach Filmwissenschaft vor große Herausforderungen – und bieten zugleich neue Chancen für Forschung und Lehre. In den kommenden fünf Jahren wird ein Team aus Filmwissenschaftlerinnen und Filmwissenschaftlern der Universitäten Marburg, Mainz und Frankfurt im »Digital Cinema-Hub« (DiCi-Hub) erforschen, wie diesen Herausforderungen und Chancen begegnet werden kann. Das Projekt wird von der VolkswagenStiftung im Rahmen der Förderlinie »Weltwissen – Strukturelle Stärkung Kleiner Fächer« mit 1 Million Euro gefördert.
DiCi-Hub stellt drei Schlüsselbereiche der Filmkultur ins Zentrum – nämlich Netzwerke (Philipps-Universität Marburg), Formate (Johannes Gutenberg-Universität Mainz) und Märkte (Goethe-Universität Frankfurt).
Der UniReport hatte die Gelegenheit, dem Filmwissenschaftler Prof. Vinzenz Hediger, der an der Goethe-Universität den Schlüsselbereich »Märkte« verantworten wird, einige Fragen zu stellen.
[Nachruf] Klaus Weltner
(2021)
[Nachruf] Julia Zernack
(2021)
Hocherfreut zeigten sich die US-amerikanischen Wissenschaftler Prof. Michael R. Silverman Ph.D. (77) und Prof. Bonnie L. Bassler Ph.D. (58), als der Vorsitzende des Stiftungsrats Prof. Thomas Boehm sie informierte: Sie erhalten den Paul Ehrlich- und Ludwig Darmstaedter-Preis 2021 für ihre Entdeckungen zur bakteriellen Kommunikation. Die feierliche Würdigung der Preisträger in der Paulskirche – auch der mit dem Nachwuchspreis ausgezeichneten Prof. Dr. Elvira Mass (34) – wird allerdings wegen der Corona-Pandemie erst im nächsten Jahr stattfinden können.
The function of the cerebral cortex essentially depends on the ability to form functional assemblies across different cortical areas serving different functions. Here we investigated how developmental hearing experience affects functional and effective interareal connectivity in the auditory cortex in an animal model with years-long and complete auditory deprivation (deafness) from birth, the congenitally deaf cat (CDC). Using intracortical multielectrode arrays, neuronal activity of adult hearing controls and CDCs was registered in the primary auditory cortex and the secondary posterior auditory field (PAF). Ongoing activity as well as responses to acoustic stimulation (in adult hearing controls) and electric stimulation applied via cochlear implants (in adult hearing controls and CDCs) were analyzed. As functional connectivity measures pairwise phase consistency and Granger causality were used. While the number of coupled sites was nearly identical between controls and CDCs, a reduced coupling strength between the primary and the higher order field was found in CDCs under auditory stimulation. Such stimulus-related decoupling was particularly pronounced in the alpha band and in top–down direction. Ongoing connectivity did not show such a decoupling. These findings suggest that developmental experience is essential for functional interareal interactions during sensory processing. The outcomes demonstrate that corticocortical couplings, particularly top-down connectivity, are compromised following congenital sensory deprivation.
leporello #7
(2021)
This paper studies the behavior of competing firms in a duopoly with rational inattentive consumers. Firms play a sequential game in which they decide to obfuscate their individual prices before competing on price. Probabilistic demand functions are endogenously determined by the consumers’ optimal information strategy, which depends on the firms’ obfuscation choice and the consumers’ unrestricted prior beliefs. We show that the game may result in an obfuscation equilibrium with high prices where both firms obfuscate and a transparency equilibrium with low prices and no obfuscation, providing an argument for market regulation. Lower information costs and asymmetric prior beliefs about prices reduce the probability of an obfuscation equilibrium. Using data on Sweden, we document a decrease in price complexity and corresponding prices in the market for mobile phone subscriptions in the last two decades. Our model rationalizes these changes and explains why complexity and high prices persist in some but not all digitalized markets.
The disposition effect is implicitly assumed to be constant over time. However, drivers of the disposition effect (preferences and beliefs) are rather countercyclical. We use individual investor trading data covering several boom and bust periods (2001-2015). We show that the disposition effect is countercyclical, i.e. is higher in bust than in boom periods. Our findings are driven by individuals being 25% more likely to realize gains in bust than in boom periods. These changes in investors’ selling behavior can be linked to changes in investors’ risk aversion and in their beliefs across financial market cycles.
The centrality of the United States in the global financial system is taken for granted, but its response to recent political and epidemiological events has suggested that China now holds a comparable position. Using minute-by-minute data from 2012 to 2020 on the financial performance of twelve country-specific exchange-traded funds, we construct daily snapshots of the global financial network and analyze them for the centrality and connectedness of each country in our sample. We find evidence that the U.S. was central to the global financial system into 2018, but that the U.S.-China trade war of 2018–2019 diminished its centrality, and the Covid-19 outbreak of 2019–2020 increased the centrality of China. These indicators may be the first signals that the global financial system is moving from a unipolar to a bipolar world.
Smart(phone) investing? A within investor-time analysis of new technologies and trading behavior
(2021)
Using transaction-level data from two German banks, we study the effects of smartphones on investor behavior. Comparing trades by the same investor in the same month across different platforms, we find that smartphones increase purchasing of riskier and lottery-type assets and chasing past returns. After the adoption of smartphones, investors do not substitute trades across platforms and buy also riskier, lottery-type, and hot investments on other platforms. Using smartphones to trade specific assets or during specific hours contributes to explain our results. Digital nudges and the device screen size do not mechanically drive our results. Smartphone effects are not transitory.
The FOMC risk shift
(2021)
We identify a component of monetary policy news that is extracted from high-frequency changes in risky asset prices. These surprises, which we call “risk shifts”, are uncorrelated, and therefore complementary, to risk-free rate surprises. We show that (i) risk shifts capture the lion’s share of stock price movements around FOMC announcements; (ii) that they are accompanied by significant investor fund flows, suggesting that investors react heterogeneously to monetary policy news; and (iii) that price pressure amplifies the stock market response to monetary policy news. Our results imply that central bank information effects are overshadowed by short-term dynamics stemming from investor rebalancing activities and are likely to be more difficult to identify than previously thought.
Broad, long-term financial and economic datasets are a scarce resource, in particular in the European context. In this paper, we present an approach for an extensible, i.e. adaptable to future changes in technologies and sources, data model that may constitute a basis for digitized and structured long- term, historical datasets. The data model covers specific peculiarities of historical financial and economic data and is flexible enough to reach out for data of different types (quantitative as well as qualitative) from different historical sources, hence achieving extensibility. Furthermore, based on historical German company and stock market data, we discuss a relational implementation of this approach.
The so-called Troika, consisting of the EU-Commission, the European Central Bank (ECB) and the International Monetary Fund (IMF), was supposed to support the member states of the euro area which had been hit hard by a sovereign debt crisis. For that purpose, economic adjustment programs were drafted and monitored in order to prevent the break-up of the euro area and sovereign defaults. The cooperation of these institutions, which was born out of necessity, has been partly successful, but has also created persistent problems. With the further increase of public debt, especially in France and Italy, the danger of a renewed crisis in the euro area was growing. The European Stability Mechanism (ESM) together with the European Commission will replace the Troika in the future, following decisions of the EU Summit of December 2018. It shall play the role of a European Monetary Fund in the event of a crisis. The IMF, on the other side, will no longer play an active role in solving sovereign debt crises in the euro area. The current course is, however, inadequate to tackle the core problems of the euro zone and to avoid future crises, which are mainly structural in nature and due to escalating public debt and lack of international competitiveness of some member countries. The current Corona crisis will aggravate the institutional problems. It has led to a common European fiscal response ("Next Generation EU"). This rescue and recovery program will not be financed by ESM resources and will not be monitored by the ESM. One important novelty of this package is that it involves the issuance of substantial common European debt.
Der Einsatz von Künstliche Intelligenz (KI) – Technologien eröffnet viele Chancen, birgt aber auch viele Risiken – insbesondere in der Finanzbranche. Dieses Whitepaper gibt einen Überblick über den aktuellen Stand der Anwendung und Regulierung von KI-Technologien in der Finanzbranche, und diskutiert Chancen und Risiken von KI. KI findet in der Finanzbranche zahlreiche Anwendungsgebiete. Dazu gehören Chatbots, intelligente Assistenten für Kunden, automatischer Hochfrequenzhandel, automatisierte Betrugserkennung, Überwachung der Compliance, Gesichtserkennungssoftware zur Kundenidentifikation u. v. m. Auch Finanzaufsichtsbehörden setzen zunehmend KI-Anwendungen ein, um große und komplexe Datenmengen (Big Data) automatisiert und skalierbar auf Muster zu untersuchen und ihren Aufsichtspflichten nachzukommen.
Die Regulierung von KI in der Finanzbranche ist ein Balanceakt. Auf der einen Seite gibt es eine Notwendigkeit Flexibilität zu gewährleisten, um Innovationen nicht einzudämmen und im internationalen Wettbewerb nicht abgehängt zu werden. Strenge Auflagen können in diesem Zusammenhang als Barriere für die erfolgreiche Weiter-)Entwicklung von KI-Applikationen in der Finanzbranche wirken. Auf der anderen Seite müssen Persönlichkeitsrechte geschützt und Entscheidungsprozesse nachvollziehbar bleiben. Die fehlende Erklärbarkeit und Interpretierbarkeit von KI-Modellen entsteht in erster Linie durch Intransparenz bei einem Großteil heutiger KI-Anwendungen, bei welchen zwar die Natur der Ein- und Ausgaben beobachtbar und verständlich ist, nicht jedoch die genauen Verarbeitungsschritte dazwischen (Blackbox Prinzip).
Dieses Spannungsfeld zeigt sich auch im aktuellen regulatorischen Ansatz verschiedener Behörden. So werden einerseits die positiven Seiten von KI betont, wie Effizienz- und Effektivitätsgewinne sowie Rentabilitäts- und Qualitätssteigerungen (Bundesregierung, 2019) oder neue Methoden der Gefahrenanalyse in der Finanzmarktregulierung (BaFin, 2018a). Andererseits, wird darauf verwiesen, dass durch KI getroffene Entscheidungen immer von Menschen verantwortet werden müssen (EU Art. 22 DSGVO) und demokratische Rahmenbedingungen des Rechtsstaats zu wahren seien (FinTechRat, 2017).
Für die Zukunft sehen wir die Notwendigkeit internationale Regularien prinzipienbasiert, vereinheitlicht und technologieneutral weiterzuentwickeln, ohne dabei die Entwicklung neuer KIbasierter Geschäftsmodelle zu bremsen. Im globalen Wettstreit sollte Europa bei der Regulierung des KI-Einsatzes eine Vorreiterrolle einnehmen und damit seine demokratischen Werte der digitalen Freiheit, Selbstbestimmung und das Recht auf Information weltweit exportieren. Förderprogramme sollten einen stärkeren Fokus auf die Entwicklung nachhaltiger und verantwortungsvoller KI in Banken legen. Dazu zählt insbesondere die (Weiter-)Entwicklung breit einsetzbarer Methoden, die es erlauben, menschen-interpretierbare Erklärungen für erzeugte Ausgaben bereitzustellen und Problemen wie dem Blackbox Prinzip entgegenzuwirken.
Aus Sicht der Unternehmen in der Finanzbranche könnte eine Kooperation mit BigTech-Unternehmen sinnvoll sein, um gemeinsam das Potential der Technologie bestmöglich ausschöpfen zu können. Nützlich wäre auch ein gemeinsames semantisches Metadatenmodell zur Beschreibung der in der Finanzbranche anfallenden Daten. In Zukunft könnten künstliche Intelligenzen Daten aus sozialen Netzwerken berücksichtigen oder Smart Contracts aushandeln. Eine der größten Herausforderungen der Zukunft wird das Anwerben geeigneten Personals darstellen.
In the past decades, the use and production of chemicals has been on the rise globally due to increasing industrialization and intensive agriculture; resulting in the occurrence and ecotoxicological risks of chemicals of emerging concern (CECs) in the aquatic compartments. Risks include changes in community structure resulting in the dominance of one species and ecosystem imbalance. When dominant disease-causing organisms are in the environment, the disease transmission is increased. For example, host snails for the schistosomiasis, a human trematode disease, are known to be tolerant to pesticide
exposure compared to the predators. This would therefore result in an increased abundance of snails which consequently increase the disease transmission in the human population.
Kenya, being a low income country faces a lot of challenges with provision of clean water, diseases and sanitation facilities, and increasing population which results in intensive agriculture coupled with pesticide use. Although a lot of research has been carried out on the environmental occurrence and risk of CECs (Chapter 1), most of these studies have been done in developed countries with limited information from Africa. Additionally, research in Africa focused on urban areas with limited number of compounds analyzed and mostly in the water phase, and inadequate information on the effects of CECs on the aquatic organisms. In order to reduce this knowledge gap, this dissertation focused on identification and quantification of CECs present in water, sediment and snails from western Kenya, and the contribution of pesticides to the transmission of schistosomiasis.
Chapter 2 gives a summary of the results and discussion of the dissertation. In Chapter 3, a comprehensive chemical analysis was carried out on 48 water samples to identify compounds, spatial patterns and associated risks for fish, crustacean and algae using toxic unit (TU) approach. A total of 78 compounds were detected with pesticides and biocides being the compounds most frequently detected. Spatial pattern analysis revealed limited compound grouping based on land use. Acute risk for crustaceans and algae were driven by one to three individual compounds. These compounds responsible for toxicity were prioritized as candidate compounds for monitoring and regulation in Kenya.
In Chapter 4, an extension of Chapter 3 was done to cover the CECs present in snails and sediment from the 48 sites. A total of 30 compounds were found in snails and 78 in sediments with 68 additional compounds being found which were not previously detected in water. Higher contaminant concentrations were found in agricultural sites than in areas without anthropogenic activities. The highest acute toxicity (TU 0.99) was determined for crustaceans based on compounds in sediment samples. The risk was driven by diazinon and pirimiphos-methyl. Acute and chronic risks to algae were driven by diuron whereas fish were found to be at low to no acute risk.
In Chapter 5, the effect of pesticide contamination on schistosomiasis transmission was evaluated by applying complimentary laboratory and field studies. In the field studies, the ecological mechanisms through which pesticides and physical chemical parameters affect host snails, predators and competitors were investigated. Pesticide data was obtained from the results in chapter 3. The overall distribution of grazers and predators was not affected by pesticide pollution. However, within the grazers, pesticide pollution increased dominance of host snails. On the contrary, the host-snail competitors were highly sensitive to pesticide exposure. For the laboratory studies, macroinvertebrates including Schistosoma-host snails, competitors and predators were exposed to 6 concentrations levels of imidacloprid and diazinon. Snails showed higher insecticide tolerance compared to competitors and predators. Finally, Chapter 6 summarizes the conclusions of this dissertation, placing it in a broader
context. In this dissertation, a comprehensive chemical characterization and risk assessment of CECs has been carried out in freshwater systems; together with the effects of pesticides on schistosomiasis transmission in rural western Kenya. Results of this dissertation showed that rural areas are contaminated posing a risk to aquatic organisms which contribute to schistosomiasis transmission. This shows the need for regular monitoring and policy formulation to reduce pollutant emissions which contributes negatively to both ecological and human health effects.
Background: Extracorporeal life support (ECLS) has become an integral part of modern intensive therapy. The choice of support mode depends largely on the indication. Patients with respiratory failure are predominantly treated with a venovenous (VV) approach. We hypothesized that mortality in Germany in ECLS therapy did not differ from previously reported literature
Methods: Inpatient data from Germany from 2007 to 2018 provided by the Federal Statistical Office of Germany were analysed. The international statistical classification of diseases and related health problems codes (ICD) and process keys (OPS) for extracorporeal membrane oxygenation (ECMO) types, acute respiratory distress syndrome (ARDS) and hospital mortality were used.
Results: In total, 45,647 hospitalized patients treated with ECLS were analysed. In Germany, 231 hospitals provided ECLS therapy, with a median of 4 VV-ECMO and 9 VA-ECMO in 2018. Overall hospital mortality remained higher than predicted in comparison to the values reported in the literature. The number of VV-ECMO cases increased by 236% from 825 in 2007 to 2768 in 2018. ARDS was the main indication for VV-ECMO in only 33% of the patients in the past, but that proportion increased to 60% in 2018. VA-ECMO support is of minor importance in the treatment of ARDS in Germany. The age distribution of patients undergoing ECLS has shifted towards an older population. In 2018, the hospital mortality decreased in VV-ECMO patients and VV-ECMO patients with ARDS to 53.9% (n = 1493) and 54.4% (n = 926), respectively.
Conclusions: ARDS is a severe disease with a high mortality rate despite ECLS therapy. Although endpoints and timing of the evaluations differed from those of the CESAR and EOLIA studies and the Extracorporeal Life Support Organization (ELSO) Registry, the reported mortality in these studies was lower than in the present analysis. Further prospective analyses are necessary to evaluate outcomes in ECMO therapy at the centre volume level.
Objective: The COVID-19 pandemic made it necessary to convert a course on history taking, in theory and practice, to an online format over a very short time. A key question was whether, and if so to what extent, basic theory and, in particular, the practical skills required to conduct medical interviews can be learned online.
Methodology/project description: The teaching program in basic theory was didactically redesigned and asynchronously placed on a learning platform, while the practical program, which consisted of training in conducting history-taking interviews, took place with the help of video conferencing software during synchronous sessions. For the practical sessions, the lecturers received organizational and technical support.
Results: Based on initial evaluation results, a positive picture of the conversion has emerged since the course was completed. The need to restructure the course and use new teaching methods because of the COVID-19 pandemic was well accepted by lecturers and students, and the course content was successfully adapted to an online format.
Conclusion: Overall, the online format enabled the learning objectives of the course to be successfully achieved. For topics such as non-verbal communication, the evaluation results indicated that a classroom format is preferable. Asynchronous theory teaching was generally very well received. Blended learning formats thus represent an appropriate means of teaching how to conduct medical interviews. Overall, online courses on conducting medical interviews provide students with the opportunity to become acquainted with the use of digital formats to conduct doctor-patient interviews, and to develop the relevant skills.
In this talk we presented a novel technique, based on Deep Learning, to determine the impact parameter of nuclear collisions at the CBM experiment. PointNet based Deep Learning models are trained on UrQMD followed by CBMRoot simulations of Au+Au collisions at 10 AGeV to reconstruct the impact parameter of collisions from raw experimental data such as hits of the particles in the detector planes, tracks reconstructed from the hits or their combinations. The PointNet models can perform fast, accurate, event-by-event impact parameter determination in heavy ion collision experiments. They are shown to outperform a simple model which maps the track multiplicity to the impact parameter. While conventional methods for centrality classification merely provide an expected impact parameter distribution for a given centrality class, the PointNet models predict the impact parameter from 2–14 fm on an event-by-event basis with a mean error of −0.33 to 0.22 fm.
Objective: Due to the prohibition of face-to-face courses during the Corona pandemic, the seminar "Written Examinations" of the Frankfurter Arbeitsstelle für Medizindidaktik (FAM) was converted into an asynchronous online seminar. This pilot project investigated how such a format is accepted and evaluated by the participants. Methodology: A forum-based online format with group and individual tasks was chosen, which was didactically designed according to the problem-oriented design by Reinmann and Mandl. Results: The seminar was attended by 14 people, 13 of whom took part in the evaluation. The overall evaluation was, with one exception, a grade of 2 (and better). The three items "practical relevance", "subjective learning success" and the question of recommendation also received very high approval ratings. The weekly workload reported by the participants was very heterogeneous (mean=2.4 hours; SD=1.1). For some participants, the use of the learning platform was not intuitive and group collaboration was somewhat faltering.Conclusion: The experiences made show that courses on medical didactics can be implemented online and are gladly accepted by the participants. Based on the experience gained, online seminars or blended learning formats will certainly continue to be part of the FAM course program in the future.
Scanning Hall probe microscopy is attractive for minimally invasive characterization of magnetic thin films and nanostructures by measurement of the emanating magnetic stray field. Established sensor probes operating at room temperature employ highly miniaturized spin-valve elements or semimetals, such as Bi. As the sensor layer structures are fabricated by patterning of planar thin films, their adaption to custom-made sensor probe geometries is highly challenging or impossible. Here we show how nanogranular ferromagnetic Hall devices fabricated by the direct-write method of focused electron beam induced deposition (FEBID) can be tailor-made for any given probe geometry. Furthermore, we demonstrate how the magnetic stray field sensitivity can be optimized in situ directly after direct-write nanofabrication of the sensor element. First proof-of-principle results on the use of this novel scanning Hall sensor are shown.
Endothelial cells play a critical role in the adaptation of tissues to injury. Tissue ischemia induced by infarction leads to profound changes in endothelial cell functions and can induce transition to a mesenchymal state. Here we explore the kinetics and individual cellular responses of endothelial cells after myocardial infarction by using single cell RNA sequencing. This study demonstrates a time dependent switch in endothelial cell proliferation and inflammation associated with transient changes in metabolic gene signatures. Trajectory analysis reveals that the majority of endothelial cells 3 to 7 days after myocardial infarction acquire a transient state, characterized by mesenchymal gene expression, which returns to baseline 14 days after injury. Lineage tracing, using the Cdh5-CreERT2;mT/mG mice followed by single cell RNA sequencing, confirms the transient mesenchymal transition and reveals additional hypoxic and inflammatory signatures of endothelial cells during early and late states after injury. These data suggest that endothelial cells undergo a transient mes-enchymal activation concomitant with a metabolic adaptation within the first days after myocardial infarction but do not acquire a long-term mesenchymal fate. This mesenchymal activation may facilitate endothelial cell migration and clonal expansion to regenerate the vascular network.
During dynamic ultrasound assessments, unintended transducer movement over the skin needs to be prevented as it may bias the results. The present study investigated the validity of two methods quantifying transducer motion. An ultrasound transducer was moved on a pre-specified 3 cm distance over the semitendinosus muscle of eleven adults (35.8 ± 9.8 years), stopping briefly at intervals of 0.5 cm. Transducer motion was quantified (1) measuring the 2-D displacement of the shadow produced by reflective tape (RT) attached to the skin and (2) using a marker-based, three-dimensional movement analysis system (MAS). Differences between methods were detected with Wilcoxon tests; associations were checked by means of intraclass correlation coefficients (ICC 3.1) and Bland–Altman plots. Values for RT (r = 0.57, p < 0.001) and MAS (r = 0.19, p = 0.002) were significantly higher than true distances (TD). Strong correlations were found between RT and TD (ICC: 0.98, p < 0.001), MAS and TD (ICC: 0.95, p < 0.001), and MAS and RT (ICC: 0.97, p < 0.001). Bland–Altman plots showed narrow limits of agreement for both RT (−0.49 to 0.13 cm) and MAS (−0.49 to 0.34 cm) versus TD. RT and MAS are valid methods to quantify US transducer movement. In view of its low costs and complexity, RT can particularly be recommended for application in research and clinical practice. View Full-Text
Keywords: ultrasound; reflective tape; transducer movement
The ability to learn sequential contingencies of actions for predicting future outcomes is indispensable for flexible behavior in many daily decision-making contexts. It remains open whether such ability may be enhanced by transcranial direct current stimulation (tDCS). The present study combined tDCS with functional near-infrared spectroscopy (fNIRS) to investigate potential tDCS-induced effects on sequential decision-making and the neural mechanisms underlying such modulations. Offline tDCS and sham stimulation were applied over the left and right dorsolateral prefrontal cortex (dlPFC) in young male adults (N = 29, mean age = 23.4 years, SD = 3.2) in a double-blind between-subject design using a three-state Markov decision task. The results showed (i) an enhanced dlPFC hemodynamic response during the acquisition of sequential state transitions that is consistent with the findings from a previous functional magnetic resonance imaging (fMRI) study; (ii) a tDCS-induced increase of the hemodynamic response in the dlPFC, but without accompanying performance-enhancing effects at the behavioral level; and (iii) a greater tDCS-induced upregulation of hemodynamic responses in the delayed reward condition that seems to be associated with faster decision speed. Taken together, these findings provide empirical evidence for fNIRS as a suitable method for investigating hemodynamic correlates of sequential decision-making as well as functional brain correlates underlying tDCS-induced modulation. Future research with larger sample sizes for carrying out subgroup analysis is necessary in order to decipher interindividual differences in tDCS-induced effects on sequential decision-making process at the behavioral and brain levels.
Aufbau: Acoustic Radiation Force Impulse (ARFI)- Bildgebung ist eine auf der konventionellen Ultraschall- Bildgebung basierende Elastographie- Methode, die die quantitative Messung der Festigkeit und Elastizität von Gewebe ermöglicht. Das Ziel der vorliegenden Studie war es, ARFI- Bildgebung für die Differenzierung von Schilddrüsenknoten zu evaluieren und mit der bereits gut erprobten qualitativen Messmethode der Real-Time Elastographie (RTE) zu vergleichen.
Material und Methoden: ARFI- Bildgebung basiert auf der Aussendung von akustischen Impulsen in Gewebe, wodurch lokale Gewebeverschiebungen hervorgerufen werden. Die dabei entstehenden Transversalwellen wiederum werden über auf Korrelation basierende Methoden mittels Ultraschallwellen detektiert und in m/s angegeben. Einschlusskriterien der Studie waren: Knoten ≥ 5 mm sowie eine zytologische/histologische Aufarbeitung. Alle Patienten erhielten eine konventionelle Ultraschall- Untersuchung, eine Real-Time Elastographie sowie eine ARFI- Bildgebung.
Ergebnisse: Es standen 158 Knoten aus 138 Patienten zur Analyse zur Verfügung. 137 Knoten erbrachten bei der zytologischen/histologischen Aufarbeitung ein benignes Ergebnis, 21 Knoten hingegen wurden als maligne eingestuft. Die mittlere Geschwindigkeit der Messungen der ARFI- Bildgebung in gesundem Schilddrüsengewebe betrug 1,76 m/s, in benignen Knoten 1,90 m/s und in malignen Knoten 2,69 m/s. Es konnte kein signifikanter Unterschied der mittleren Geschwindigkeit zwischen gesundem Schilddrüsengewebe und benignen Knoten ermitteltet werden, wohingegen ein signifikanter Unterschied zwischen malignen Knoten und gesundem Schilddrüsengewebe (p= 0,0019) einerseits und benignen Schilddrüsenknoten (p=0,0039) andererseits bestand. Für die diagnostische Genauigkeit bei der Diagnose von malignen Schilddrüsenknoten konnte kein signifikanter Unterschied zwischen RTE und ARFI- Bildgebung festgestellt werden (0,74 vs. 0,69, p=0,54). Die Kombination von RTE und ARFI- Bildgebung erhöhte die Spezifität bei der Diagnose von malignen Schilddrüsenknoten von 72% (nur RTE) auf 92% (kombiniert).
Schlussfolgerungen: ARFI- Bildgebung kann als zusätzliche Methode bei der diagnostischen Aufarbeitung von Schilddrüsenknoten genutzt werden und liefert dabei einen hohen negativen prädiktiven Wert sowie vergleichbare Ergebnisse wie die RTE.
Despite the increasing use of cashless payment instruments, the notion that cash loses importance over time can be unambiguously refuted. In contrast, the authors show that cash demand increased steeply over the past 30 years. This is not only true on a global scale, but also for the most important currencies in advanced countries (USD, EUR, CHF, GBP and JPY). In this paper, they focus especially on the role of different crises (technological crises, financial market crises, natural disasters) and analyse the demand for small and large banknote denominations since the 1990s in an international perspective. It is evident that cash demand always increases in times of crises, independent of the nature of the crisis itself. However, largely unaffected from crises we observe a trend increase in global cash aligned with a shift from transaction balances towards more hoarding, especially in the form of large denomination banknotes.
Uni-Highlights Februar 2021 : Einladungen zu ausgewählten Veranstaltungen der Goethe-Universität
(2021)
Tuberöse Sklerose („tuberous sclerosis complex“ [TSC]) ist eine seltene genetische Erkrankung, die neben kutanen und viszeralen Organmanifestationen typischerweise bereits in einem sehr frühen Erkrankungsstadium mit einer schweren, meist therapierefraktären Epilepsie einhergeht. Aufgrund seiner direkten Wirkung am durch TSC dysregulierten mTOR-Signalweg sowie der synergistischen Effekte auf andere Organmanifestationen kommt das Rapamycin-Derivat Everolimus (EVE) zunehmend zur Anwendung. Ziel dieses systematischen Reviews ist, die Wirksamkeit, Sicherheit und Verträglichkeit von EVE bei Patienten mit TSC-assoziierter, therapierefraktärer Epilepsie aufzuarbeiten.