Cy Twombly. Bild, Text, Paratext

Die Bildwerke des US-amerikanischen Künstlers Cy Twombly (1928–2011) gelten als hermetisch und schwer zugänglich. Bleistiftgekritzel, Farbballungen, taumelnde Linien, einander überlagernde Farbschichten und Einschreibungen, geometrische Figuren, Zahlen, Zahlenreihen, Wörter, Zitatfragmente und rätselhafte Bildtitel stellen Forscher wie Betrachter vor ganz besondere Herausforderungen. Gemäß der interdisziplinär-transkulturellen Forschungsmethode des Internationalen Kollegs Morphomata an der Universität zu Köln versammelte im Juni 2012 ein Kongress neben Kunsthistorikern auch namhafte Fachleute aus den Bereichen Ägyptologie, Archäologie, Germanistik, Gräzistik, Anglistik, Japanologie und Romanistik, d.h. all jenen Fachgebieten und Kulturkreisen, die eine Inspirationsquelle für das OEuvre Cy Twomblys darstellten. Befragen diese den Bezug zwischen Werktitel, Werk und eingeschriebenen Zitaten, so legen führende Vertreter der Twomblyforschung den Fokus auf Bildsprache und Schriftbildlichkeit bei Cy Twombly. Durch umfassende Deutungen berühmter Einzelwerke und Werkgruppen in sämtlichen von Twombly angewandten künstlerischen Medien erschließt der Band in einem fächerübergreifenden Blick einen Zugang zur assoziativ-referentiellen Bildsprache Cy Twomblys

Cy Twombly. Image, Text, Paratext

The artworks of the US artist Cy Twombly (1928–2011) are considered to be hermetic and inaccessible. Pencil scribblings, explosions of paint, tumbling lines, overlapping layers of color, and inscriptions, geometrical figures, numerals, rows of numbers, words, fragments of quotations, and enigmatic work-titles present very special challenges to both researchers and viewers. In the interdisciplinary and transcultural research method of the Morphomata International Center for Advanced Studies at the University of Cologne, a conference was held in June 2012 that brought art historians together with renowned scholars of Egyptology, Archaeology, German, Greek, English, Japanese, and the Romance languages, i.e. all the fields and cultural spheres that were a source of inspiration for the œuvre of Cy Twombly. While these scholars inquire into the relation between title, work, and inscribed quotations, leading representatives of research on Twombly focus on the visual language and scriptural-imagistic quality of Cy Twombly’s work. Through comprehensive interpretations of famous single works and groups in all the artistic media employed by Twombly, the volume’s cross-disciplinary view opens up a route into the associative-referential visual language of Cy Twombly

HIF1α is a regulator of hematopoietic progenitor and stem cell development in hypoxic sites of the mouse embryo

Hypoxia affects many physiologic processes during early stages of mammalian ontogeny, particularly placental and vascular development. In the adult, the hypoxic bone marrow microenvironment plays a role in regulating hematopoietic stem cell (HSC) function. HSCs are generated from the major vasculature of the embryo, but whether the hypoxic response affects the generation of these HSCs is as yet unknown. Here we examined whether Hypoxia Inducible Factor1-alpha (HIF1α), a key modulator of the response to hypoxia, is essential for HSC development. We found hypoxic cells in embryonic tissues that generate and expand hematopoietic cells (aorta, placenta and fetal liver), and specifically aortic endothelial and hematopoietic cluster cells. A Cre/loxP conditional knockout (cKO) approach was taken to delete HIF1α in Vascular Endothelial-Cadherin expressing endothelial cells, the precursors to definitive hematopoietic cells. Functional assays show that HSC and hematopoietic progenitor cells (HPCs) are significantly reduced in cKO aorta and placenta. Moreover, decreases in phenotypic aortic hematopoietic cluster cells in cKO embryos indicate that HIF1α is necessary for generation and/or expansion of HPCs and HSCs. cKO adult BM HSCs are also affected under transplantation conditions. Thus, HIF1α is a regulator of HSC generation and function beginning at the earliest embryonic stages

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

Canine borreliosis: a laboratory diagnostic trial

The aim of this study was to investigate samples from dogs suggestive of active canine borreliosis (group A) by culture and PCR and the detection of antibodies against Borrelia burgdorferi sensu lato in order to confirm a presumptive clinical diagnosis of canine borreliosis by laboratory results. Criteria for such a diagnosis were: history of tick exposure, lameness, neurological signs, nephropathy, lethargy, anorexia, and fever. A total of 302 samples comprising EDTA blood, urine, synovial fluid, cerebrospinal fluid, and tissue (skin, synovial membrane, kidney) from 98 dogs (26 with arthritis, 46 with neurological signs, 21 with nephropathy, 5 with non-specific symptoms) were collected and examined. Moreover, 55 healthy dogs (group B) and 236 dogs with symptoms or injuries unlikely to be associated with borreliosis (group C) were included in this study. Blood serum samples collected from all individuals (n=389) were analysed by ELISA. Twenty-one (21%) out of 98 dogs from group A, 4 (7%) out of 55 from group B and 15 (6%) out of 236 dogs from group C were positive for antibodies against B. burgdorferi sensu lato. The seroprevalences between groups A, B and C differed significantly. None of the corresponding samples investigated by PCR and culture were positive for spirochetal DNA or viable spirochetes. Borrelia afzelii was grown from one EDTA-blood sample but the corresponding blood serum sample remained antibody-negative. Consequently, the etiologic role of B. afzelii in this case is unclear. In approximately 40% of the presumptive canine borreliosis cases, other lesions have been found to be responsible for clinical signs. This study affirms that a definitive diagnosis of canine borreliosis cannot be made by clinical symptoms and serology based on a single consultation. Moreover, this study clearly revealed that the diagnostic sensitivity is enhanced by a thorough consideration and exclusion of other diseases