A Match Not Made in Heaven : Artist Anecdotes and the ‘Dialogues of the Dead’

Peer reviewedPublisher PD

Influence of interface conditioning and dopants on Cd-free buffers for Cu(In,Ga)(S,Se)2 solar cells

In the search for a non-toxic replacement of the commonly employed CdS buffer layer for Cu(In,Ga)(S,Se)2 (CIGSSe) based solar cells, indium sulfide thin films, deposited via thermal evaporation, and chemical bath deposited (CBD) Zn(O,S) thin films are promising materials. However, while both materials have already been successfully utilized in highly efficient cells, solar cells with both materials usually need an ill-defined post-treatment step in order to reach maximum efficiencies, putting them at a disadvantage for mass production. In this thesis the influence of interface conditioning and dopants on the need for post-treatments is investigated for both materials, giving new insights into the underlying mechanisms and paving the way for solar cells with higher initial efficiencies. First, CIGSSe solar cells with In2S3 thin film buffer layers, deposited by thermal evaporation, are presented in chapter 3. The distinctive improvement of these buffer layers upon annealing of the completed solar cell and the change of this annealing behavior when the CIGSSe surface is treated with wet-chemical means prior to buffer layer deposition is investigated. Additional model simulations lead to a two-part explanation for the observed effects, involving a reduction of interface recombination, and the removal of a highly p-doped CIGSSe surface layer. chapter 4 introduces a novel, fast process for the deposition of Zn(O,S) buffer layers on submodule sized substrates. The resulting solar cell characteristics and the effects of annealing and prolonged illumination are discussed within the framework of theoretical considerations involving an electronic barrier for generated charge carriers. The most important influences on such an electronic barrier are investigated by model simulations and an experimental approach to each parameter. This leads to an improved window layer deposition process, absorber optimization, and intentional buffer layer doping, all reducing the electronic barrier and therefore the necessity for post-treatments to some extent. The energetic barrier discussed above may be avoided altogether by effective interface engineering. Therefore, the controlled incorporation of indium as an additional cation into CBD-Zn(O,S) buffer layers by means of a newly developed alkaline chemical bath deposition process is presented in chapter 5. With increasing amount of incorporated indium, the energetic barrier in the conduction band can be reduced. This is quantitatively assessed by a combination of photoelectron spectroscopy measurements and the determination of the buffer layer's optical band gap. This barrier lowering leads to less distorted current--voltage characteristics and efficiencies above 14 %, comparable to CdS reference cells, without extensive light-soaking

The role of different GFI1-expressionlevel in the progression of MDS and AML

The presented data of this doctoral thesis suggest that the transcription factor GFI1/Gfi1 plays an important role in the progression and manifestation of AML. AML patients with low GFI1 expression in their blasts showed an inferior prognosis and a shortend EFS and OS. Furthermore, the KD of GFI1 resulted in a block of differentiation in the bone marrow of mice. The KO and the KD of GFI1/Gfi1 lead to an enhanced AML progression in the MLL-AF9 mouse model. In addition, upregulation of Gfi1 resulted in an increase of differentiation of bone marrow cells and a decrease of monocytosis in a persisting AML. It could be shown that the KO of Gfi1 impeded AML progression whereas the KD of GFI1 accelerated AML progression in the NUP98/HOXD13 mouse model. In cooperation with the the IRCM in Canada it could also be shown that H3K9 acetylation at GFI1 target genes is increased in the bone marrow of GFI1-KD-NUP98/HOXD13 mice. Further analysis of gene expression (Gene Set Enrichement Analysis) showed an upregulation of those genes that belong to "cluster 5" which were defined by Valk et al. as a subgroup of AML patients with poor prognosis. These data suggest, that the GFI1-KD-NUP98/HOXD13 mice recapitulate the situation of AML patients with an inferior prognosis very well. Moreover, the essential role of GFI1/Gfi1 for AML progression and manifestation in AML1-ETO9a- and CBFB-MYH1- mouse models could be demonstrated. Furthermore the here depicted results open up new vistas in treating AML patients with epigenetic drugs. As well as in murine as in human leucemic bone marrow cells it could be shown that cells with low GFI1 expression responded better to the treatment with the HATi CTK7a. This could be also confirmed in first in vivo experiments. Taken together, the presented data suggest that GFI1/Gfi1 plays a level- and dose-dependent role in progression of AML in the here used mouse models and that different GFI1/Gfi1 expression levels could be exploited as new prognostic factor in order to establish a new epigenetic therapy for MDS/AML patients

‘Painting Art History’. Review of: Léa Kuhn, Gemalte Kunstgeschichte. Bildgenealogien in der Malerei um 1800, Paderborn: Fink 2020, ISBN-13: 978-3-7705-6453-8, 333pp., EUR 69,00.

In her new book “Gemalte Kunstgeschichte” [Painted Art History] Léa Kuhn argues that the late 18th-century saw not only the rise of modern art historiography as a scholarly discipline, but that artists increasingly painted pictures that reflected on their own historicity. Kuhn develops her argument through close-readings of three self-portraits by Johann Heinrich Wilhelm Tischbein, William Dunlap, Marie-Gabrielle Capet. This review discusses her approach and its the insights it offers for the study of art historiography

‘Authority and Authenticity in Art Writing’. Review of: Matthias Krüger, Léa Kuhn, Ulrich Pfisterer (Eds): Pro Domo. Kunstgeschichte in eigener Sache, Paderborn: Brill Fink 2021. ISBN: 978-3-8467-6506-7, 405 p., €73.83.

The review discusses the edited volume Pro Domo. Kunstgeschichte in eigener Sache. The volume aims to analyse systematically an understudied sub-genre of art writing: texts that were written by confidantes of the artists, thus suggesting a specific authority and authenticity as they claim to have ‘in-house’ knowledge of the master’s mind. The review situates the volume’s concept and approach within recent discussions on subjectivity in art writing

Anfang und Metapher. George Kubler und das Problem künstlerischer Innovation

George Kublers Essay The Shape of Time (1962) ist in den letzten Jahren zu einer zentralen Orientierungsgröße in der kunsthistorischen Methodendiskussion aufgestiegen. Betont wurde dabei insbesondere sein Anspruch, eine »Geschichte der Dinge« zu entwerfen, in der die Kunstwerke selbst als Akteure betrachtet werden, sowie die damit einhergehende Abkehr vom traditionellen Geniegedanken. Im Folgenden soll dagegen gezeigt werden, dass Kublers Denken sehr wohl der Vorstellung eines genialen und autonom produzierenden Subjekts verhaftet blieb. Im Zentrum des Interesses steht dabei Kublers Konzept der sogenannten »prime objects«, die als Inbegriff künstlerischer Innovation beschrieben werden

Effective ventilation and chest compressions during neonatal resuscitation – the role of the respiratory device

Background: The success of cardiopulmonary resuscitation (CPR) in newborns largely depends on effective lung ventilation; however, a direct randomized comparison using different available devices has not yet been performed. Methods: Thirty-six professionals were exposed to a realistic newborn CPR scenario. Ventilation with either a bag-valve mask (BVM), T-piece, or ventilator was applied in a randomized manner during CPR using a Laerdal manikin. The primary outcome was the number of unimpaired inflations, defined as the peak of the inflation occurring after chest compression and lasting at least 0.35 s before the following chest compression takes place. The secondary outcomes were tidal volume delivered and heart compression rate. To simulate potential distractions, the entire scenario was performed with or without a quiz. Statistically, a mixed model assessing fixed effects for experience, profession, device, and distraction was used to analyze the data. For direct comparison, one-way ANOVA with Bonferroni's correction was applied. Results: The number of unimpaired inflations was highest in health care professionals using the BVM with a mean ± standard deviation of 12.8 ± 2.8 (target: 15 within 30 s). However, the tidal volumes were too large in this group with a tidal volume of 42.5 ± 10.9 ml (target: 25-30 ml). The number of unimpaired breaths with the mechanical ventilator and the T-piece system were 11.6 (±3.6) and 10.1 (±3.7), respectively. Distraction did not change these outcomes, except for the significantly lower tidal volumes with the T-piece during the quiz. Conclusions: In summary, for our health care professionals, ventilation using the mechanical ventilator seemed to provide the best approach during CPR, especially in a population of preterm infants prone to volutrauma

Document analysis at DFKI. - Part 1: Image analysis and text recognition

Document analysis is responsible for an essential progress in office automation. This paper is part of an overview about the combined research efforts in document analysis at the DFKI. Common to all document analysis projects is the global goal of providing a high level electronic representation of documents in terms of iconic, structural, textual, and semantic information. These symbolic document descriptions enable an "intelligent\u27; access to a document database. Currently there are three ongoing document analysis projects at DFKI: INCA, OMEGA, and PASCAL2000/PASCAL+. Though the projects pursue different goals in different application domains, they all share the same problems which have to be resolved with similar techniques. For that reason the activities in these projects are bundled to avoid redundant work. At DFKI we have divided the problem of document analysis into two main tasks, text recognition and text analysis, which themselves are divided into a set of subtasks. In a series of three research reports the work of the document analysis and office automation department at DFKI is presented. The first report discusses the problem of text recognition, the second that of text analysis. In a third report we describe our concept for a specialized document analysis knowledge representation language. The report in hand describes the activities dealing with the text recognition task. Text recognition covers the phase starting with capturing a document image up to identifying the written words. This comprises the following subtasks: preprocessing the pictorial information, segmenting into blocks, lines, words, and characters, classifying characters, and identifying the input words. For each subtask several competing solution algorithms, called specialists or knowledge sources, may exist. To efficiently control and organize these specialists an intelligent situation-based planning component is necessary, which is also described in this report. It should be mentioned that the planning component is also responsible to control the overall document analysis system instead of the text recognition phase onl

Metadata: how we relate to images

METADATA. HOW WE RELATE TO IMAGES Lethaby Gallery 10 Jan—3 Feb 2018 An exhibition organised by the International Research Group “Bilderfahrzeuge. Aby Warburg’s Legacy and the Future of Iconology” in collaboration with Central Saint Martins, University of the Arts London

Sex-specific phenotypes of hyperthyroidism and hypothyroidism in mice

Background Thyroid dysfunction is more common in the female population, however, the impact of sex on disease characteristics has rarely been addressed. Using a murine model, we asked whether sex has an influence on phenotypes, thyroid hormone status, and thyroid hormone tissue response in hyper- and hypothyroidism. Methods Hypo- and hyperthyroidism were induced in 5 -month-old female and male wildtype C57BL/6N mice, by LoI/MMI/ClO4 − or T4 i.p. treatment over 7 weeks, and control animals underwent sham treatment (N = 8 animals/sex/treatment). Animals were investigated for impact of sex on body weight, food and water intake, body temperature, heart rate, behaviour (locomotor activity, motor coordination, and strength), liver function, serum thyroid hormone status, and cellular TH effects on gene expression in brown adipose tissue, heart, and liver. Results Male and female mice showed significant differences in behavioural, functional, metabolic, biochemical, and molecular traits of hyper- and hypothyroidism. Hyperthyroidism resulted in increased locomotor activity in female mice but decreased muscle strength and motor coordination preferably in male animals. Hypothyroidism led to increased water intake in male but not female mice and significantly higher serum cholesterol in male mice. Natural sex differences in body temperature, body weight gain, food and water intake were preserved under hyperthyroid conditions. In contrast, natural sex differences in heart rate disappeared with TH excess and deprivation. The variations of hyper- or hypothyroid traits of male and female mice were not explained by classical T3/T4 serum state. TH serum concentrations were significantly increased in female mice under hyperthyroidism, but no sex differences were found under eu- or hypothyroid conditions. Interestingly, analysis of expression of TH target genes and TH transporters revealed little sex dependency in heart, while sex differences in target genes were present in liver and brown adipose tissue in line with altered functional and metabolic traits of hyper- and hypothyroidism. Conclusions These data demonstrate that the phenotypes of hypo- and hyperthyroidism differ between male and female mice and indicate that sex is an important modifier of phenotypic manifestations