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Chinese Capital Flows to African Economies and Real Bilateral Exchange Rates
No full textSince the turn of the millennium, China opened up internationally both in terms of its current account (trade) and its capital account, even though the opening of the latter happened de facto, not de jure. With respect to China being Africa's largest trading partner and developing investor in combination with its desire for African natural resources, we embark on an analysis of the impact of several categories of Chinese capital flows to African economies on the bilateral real exchange rate. We conduct a panel data analysis by means of a Hausman-Taylor-estimation over the period 2003-2016. Our results suggest that capital flows from China to Africa in the form of mainly economic cooperation projects, but also FDI contribute to an appreciation of the local currencies vis _a vis the RMB, while no such effect appears for aid flows from China. The former two categories may pose a risk of Dutch Disease effects. Since many African countries have pegged their currencies to the Euro, and the Renminbi abandoned its peg to the US Dollar over the sample period, valuation effects of capital flows must be interpreted in this context
Valleys are a potential refuge for the Amazon lowland forest in the face of increased risk of drought
No full textThe Amazon rainforest is home to an incredible variety of plant and animal species and plays a crucial role in regulating the Earth’s climate. Climate change and human activities are putting this important ecosystem at risk. In particular, increasing droughts are making it harder for certain organisms to survive. Here we analyse a satellite-based data set of fog/low-stratus (FLS) frequency and a spatio-temporal drought index. We show that vulnerable organisms may find refuge in river valleys where FLS provides a source of moisture. We find that these favourable microclimates exist throughout the Amazon basin, with the highest occurrence and stability in steep river valleys. We suggest that protecting these hygric climate change refugia could help preserve the biodiversity and functioning of the Amazon ecosystem in the face of future droughts. This would also help stabilise atmospheric moisture recycling, making the region more resilient to climate change.Gefördert durch den Open-Access-Publikationsfonds der UB Marburg
Examination Rules and Student Effort
No full textThis paper contributes to the economics of examination rules. We show how
rational students reallocate their learning e¤ort as a response to a charge for the second exam attempt, a cap on the maximum resit mark, an adjustment of the passing standard, a variation of the time span between two attempts, a minimum requirement to qualify for the second attempt, and a malus points account. The effort maximizing rule is the malus account, a charge for the second attempt delivers the highest overall passing probability
The Influence of Politicians’ Sex on Political Budget Cycles: An Empirical Analysis of Spanish Municipalities
No full textDoes a politician’s sex influence political budget cycles (PBCs)? We answer this question using a sample of Spanish municipalities from the Madrid region for the period 2010−2019. The Madrid region has a homogenous set of budget rules that allows consistently categorising budget expenditure items as either ‘mandatory’ or ‘non-mandatory’ public services. After differentiating between smaller and larger municipalities, gender influence is studied along two dimensions: mayor’s sex and share of women in government. Our findings include, in regard to mandatory spending in smaller municipalities, that gender-balanced governments induce PBCs. In larger municipalities, when the share of women in government is above 60%, electoral spending is increased by up to 10% of an average municipal budget for mandatory spending, and up to 2.2% for non-mandatory. These findings are generally supported in a mixed-gender close election analysis
What’s that Noise? Analysing Sentiment-based Variation in Central Bank Communication
No full textTo which degree can variation in sentiment-based indicators of central bank communication be attributed to changes in macroeconomic, financial, and monetary variables; idiosyncratic speaker effects; sentiment persistence; and random ‘noise’? Using the Loughran and McDonald (2011) dictionary on a text corpus containing more than 10,000 speeches and press statements, we construct sentiment-based indicators for the ECB and the Fed. An analysis of variance (ANOVA) shows that sentiment is strongly persistent and influenced by speaker-specific effects. With about 80% of the variation in sentiment being due to noise, our findings cast doubt on the reliability of conclusions based on variation in dictionary-based indicators
Sensory enhancement of peripheral vision
No full textMore than 99% of the visual information is sampled by peripheral vision. Despite covering the majority of the visual field, the peripheral vision offers lower visual resolution than the fovea, that is responsible from gathering high resolution information from the central visual field. Although visual sensitivity changes drastically across the retina as a function of eccentricity, our visual experiences appear to be homogeneous. This apparent visual homogeneity is achieved by our visual system striving to optimize information gathering and minimize biological costs. To this end, the visual system uses various heuristics stemming from priors and expectations while dividing the labor of gathering information between available sensory systems. The aim of this dissertation is to provide an account of how various sensory mechanisms support peripheral vision. Particularly, in three studies, it investigated how peripheral vision and the execution of peripheral tasks are supported by transsaccadic learning and prediction, neural feedbacks providing additional processing resources, and supplementary information from other senses.
Study I investigated how transsaccadic learning and object predictions of familiar objects supports peripheral vision. Through transsaccadic learning the visual system associates how the appearance of an object or a feature change from periphery to fovea. Using these object specific associations visual system generates predictions about these objects and how they would look like at different eccentricities. In addition, through lifelong experience on how object appearance changes as a function of eccentricity, the visual system could generate predictions even for novel objects. However, it was unclear whether object specific predictions reserved for familiar objects provide an advantage over general predictions that are also available for novel objects in visual tasks. Study I addressed this question in two experiments where observers unknowingly familiarized with a subset of the objects by performing a sham task that required them to make saccades to these objects. On the following day, they either performed a peripheral-foveal matching or transsaccadic change detection task with familiarized and novel objects. We found that the presence of familiar objects improved the performance in both tasks by providing more precise object specific predictions from previous peripheral-foveal associations that generalize across the visual hemifields. Thus, Study I shows that object specific predictions unique to familiar objects provide additional support to the peripheral vision and execution of peripheral tasks.
Study II investigated a neural feedback mechanism that allows peripheral information to be processed in the fovea retinotopic cortex and supports peripheral discrimination. The support of the foveal-feedback mechanism in peripheral discrimination can be impaired when a foveal input is presented asynchronously with peripheral targets. However, it was not clear whether the peripheral object information has to compete with the foveal input for the same neural resources, or if it is masked by it. Study II tested both explanations with a peripheral letter discrimination using both novel and familiar characters. Crucially, we manipulated the spatial frequency compositions of the foveal noise. Thus, if the foveal noise is masking the foveal-feedback, we would expect the efficiency of the foveal noises to vary depending on the amount of shared spatial frequency with the peripheral characters. Alternatively, if foveal noise is competing with the foveal-feedback, we would expect a more general effect of foveal noise independent from how they are similar to the peripheral characters. We found that low spatial frequency foveal noise was more effective at impairing the peripheral discrimination of both familiar and novel characters, indicating a frequency specific masking of foveal-feedback. We follow-up this result with a control experiment where the low and medium spatial frequency noises were presented overlappingly with the peripheral and foveal characters. As anticipated, we found that low frequencies were more effective at masking peripheral characters than medium frequencies while the opposite pattern was true for the foveal characters. Additionally, behavioral oscillation analyses suggested that the masking of foveal-feedback is periodic at around 5 Hz. Thus, Study II shows that the peripheral discrimination of both novel and familiar objects is supported by a foveal-feedback mechanism that periodically processes peripheral information and subjects to masking.
Study III investigated how imprecise peripheral information can be combined with sensory information from other modalities. More specifically, virtual and augmented reality applications are promising for augmenting user performance and experience by providing supplementary information across senses. However, one major bottleneck for these applications is to supplement information within a tight spatiotemporal window across different sensory modalities. Therefore, if and how spatiotemporally incongruent information from different sources is an important theoretical question with direct implications. Study III addressed this question by testing how imprecise peripheral information can be combined with supplementary tactile information when they are spatially and temporally incongruent. Using a custom-built setup, observers performed visual displacement judgments with or without spatially or temporally incongruent or congruent tactile displacement cues. Using their performance in the visual only condition, we modeled how observers combine visual and tactile information in the visuotactile conditions. We found that the combination weights systematically shifted towards tactile cues under temporal incongruency compared to congruency condition. In contrast, spatial incongruency altered how visual and tactile information are combined and hinted possible individual differences in cue combination strategies. Thus, the weighting of visual and tactile information is modulated and altered by spatial and temporal incongruency which might have important consequences for multisensory applications. Nevertheless, Study III suggests that despite large temporal and spatial incongruencies tactile cues can supplement peripheral visual information.
In three studies, this dissertation seeks to understand how peripheral vision is supported by diverse neural and sensory mechanisms. In particular, peripheral vision is supported by precise object associations for familiar objects that are acquired through transsaccadic learning. These familiar object associations benefit peripheral matching and transsaccadic change detection by providing more precise peripheral to foveal and foveal to peripheral predictions than the general predictions available also for novel objects. Regardless of their familiarity, the peripheral discrimination of objects is also supported by a foveal-feedback mechanism that periodically processes peripheral object information in the foveal retinotopic areas. However, the processing of peripheral information is prone to masking by delayed foveal inputs with matching spatial frequency composition as the peripheral object. On the other hand, supplementary tactile information can be combined with imprecise peripheral information despite spatiotemporal incongruencies. However, while temporal incongruencies shift the weighting of visual and tactile information, spatial incongruencies can alter combination strategies differently across different individuals. In conclusion, these sensory interactions between peripheral vision and other sensory mechanisms support peripheral vision and offer better peripheral estimates for performing various tasks
Expectations do not need to be accurate to be maintained: Valence and need for cognitive closure predict expectation update vs. persistence
No full textExpectations about us and our environment serve to successfully anticipate the
future, make accurate predictions, and guide behavior and decisions. However,
when expectations are not accurate, individuals need to resolve or minimize
incongruence. Coping is especially important when expectations affect important
domains such as students’ academic self-concept. Whether expectations are
adjusted after expectation violation (accommodation), maintained by denying the
discrepancy (immunization), or whether individuals modify behavior to minimize the
likelihood of future expectation violations (assimilation) depends on situational and
dispositional predictors. In our experiment, we examined valence of expectation
violation (positive vs. negative) as a situational predictor together with need for
cognitive closure (NCC) as a dispositional predictor with N = 297 participants in a
word riddle study. MANCOVA revealed that students tended to assimilate and
accommodate more strongly after worse-than-expected achievement, and also
NCC promoted both stronger accommodation and assimilation. NCC interacted
with the valence of expectation violation: individuals with high NCC reported more
assimilation and accommodation only after worse-than-expected achievement.
The results replicate and extend previous findings: individuals do not always strive
to have the most accurate expectations possible. Instead, both affective (valence)
and cognitive (NCC) predictors appear to affect which coping strategy is preferred
by the individual.Gefördert durch den Open-Access-Publikationsfonds der UB Marburg
Mutationsstudien und Strukturanalysen der proteinbasierten RNase P aus dem hyperthermophilen Bakterium Aquifex aeolicus und Homologen
No full textDer Reifungsprozess von Transfer-RNAs (tRNAs) ist essenziell für die Proteinbiosynthese und
kommt in allen Lebensformen vor. Ein wichtiger Schritt dieser Maturierung ist die
endonukleolytische Abspaltung der 5’-Flanke einer Vorläufer-tRNA (Prä-tRNA) durch das
Enzym Ribonuklease P (RNase P). Eine Form der RNase P, die in allen drei Domänen des
Lebens vorkommt, besteht aus einer katalytischen RNA und einem Proteinanteil. Hierbei
variiert der Proteinanteil von einer Untereinheit in Bakterien, über vier bis fünf in Archaeen
und bis zu zehn in Eukaryoten. Es existieren jedoch auch ausschließlich proteinbasierte
Formen der RNase P in Eukaryoten. Dazu gehören die RNase P tierischer Mitochondrien
(mtRNase P), die einen Komplex aus drei Protein-Untereinheiten bildet. Zur Nuklease-
Untereinheit der mtRNase P homologe Enzyme, die als Einzelprotein aktiv sind und als
protein-only RNase P (PRORP) bezeichnet werden, wurden auch in vielen anderen
Eukaryonten gefunden, wie z.B. in der Landpflanze Arabidopsis!thaliana. Kürzlich wurde
zudem eine proteinbasierte RNase P-Form in dem hyperthermophilen Bakterium Aquifex!
aeolicus identifiziert, welche eine PilT N-terminus (PIN)-ähnliche Nukleasedomäne besitzt
und ausschließlich aus einer nur etwa 23 kDa großen Proteinkomponente besteht, die
allerdings oligomerisieren kann. Homologe der Aquifex RNase P (HARPs) werden ebenfalls in
einigen anderen Bakterien und zahlreichen Archaeen exprimiert, wobei sie in diesen
Archaeen immer gemeinsam mit der RNA-basierten RNase P vorliegen und nicht die Haupt-
RNase P-Aktivität darstellen. Die Funktion der HARPs in Archaeen ist bisher unbekannt und
wenig untersucht.
Um herauszufinden, wie die zuvor erwähnten kleinen HARP-Proteine das Prä-tRNA-Substrat
erkennen und binden, wurden Mutationsstudien der A.!aeolicus RNase P (AaRP)
durchgeführt. Zudem wurde ein Fokus auf die Strukturanalyse der AaRP und anderer HARPs
gelegt, um mithilfe verschiedener Methoden Informationen über den Aufbau des Enzyms
und dessen Funktion zu gewinnen. Aufgrund der konformativen Heterogenität des Cterminalen
Endes des His-tag-markierten AaRP-Proteins (ORF Aq880) konnte von unserer
Seite jedoch keine Struktur der AaRP auf atomarer Ebene generiert werden.
Massenphotometrie-Daten zeigten allerdings, dass das homologe Protein aus
Halorhodospira! halophila (ORF Hhal2243) im Gegensatz zu Aq880 in einem homogenen
Strukturzustand vorlag, sodass mittels Kryoelektronenmikroskopie (Kryo-EM) die Apo-
Struktur des bakteriellen HARPs aus H.!halophila mit 3,37 Å gelöst werden konnte. Es stellte
sich heraus, dass das monomere Protein (!24 kDa) schraubenartig zu einem Dodecamer
oligomerisiert. Höhere Oligomere sind aus sterischen Gründen ausgeschlossen. Zwei
Hhal2243-Monomere bilden ein stabiles Dimer, indem sich ihre "Spike-Helix"(SH)-Domänen,
bestehend aus den beiden Helices"#5"und #6,"zu"einem"4-Helix-Bündel zusammenlagern. So
ragen insgesamt sechs dieser Helix-Bündel aus der dodecameren Anordnung heraus. Die
hervorstehenden Spike-Helices von HARP-Dimeren, die die konservierte Ellbogen-Region der
tRNA binden, tragen maßgeblich zur Substratbindung bei. Ein Docking-Modell sagt vorher,
dass"die" zu"prozessierende" 5'-Flanke wiederum in das aktive Zentrum eines benachbarten Dimers ragen würde und somit ein Tetramer die kleinste funktionelle Einheit für die
enzymatische Spaltung von Prä-tRNA-Substraten darstellt. Die gelöste Kryo-EM Struktur
stellt eine wichtige Grundlage für weitere Forschungen zum biologischen und
mechanistischen Verständnis der tRNA-Prozessierung durch prokaryotische HARPs dar.The maturation process of transfer RNAs (tRNAs) is essential for protein biosynthesis and
occurs in all domains of life. An important step in the maturation is the endonucleolytic
removal of the 5’-leader sequence from the precursor tRNA (pre-tRNA) by the ribonuclease P
(RNase P). RNase P occurs as a ribonucleoprotein enzyme in all three domains of life and is
composed of a catalytic RNA and a protein moiety. The protein content varies from one
subunit in bacteria, four to five in archaea and up to ten in eukaryotes. However, there are
also exclusively protein-based forms of RNase P in eukaryotes, such as the mitochondrial
RNase P complex (mtRNase P) of animal mitochondria consisting of three different protein
subunits. Homologs of the nuclease subunit of mtRNase P were also identified in many other
eukarya where they act as a single protein enzyme termed PRORP, a prominent model
system being the PRORP of the land plant Arabidopsis thaliana. Recently, a protein-based
RNase P form was identified in the hyperthermophilic bacterium Aquifex! aeolicus, which
possesses a PIN-like nuclease domain and is soley composed of protein as small as about
23 kDa. Aquifex RNase P homologues (HARPs) are also expressed in some bacteria and
numerous archaea. In all of these archaea, the HARPs coexist with the RNA-based RNase P
and do not represent the main RNase P activity. The main function of HARPs in Archaea is
unknown.
To elucidate how HARPs are able to recognize and bind the pre-tRNA substrate, mutational
studies of the Aquifex! aeolicus! RNase P (AaRP) were performed. In addition, a focus was
placed on the structural analysis of AaRP and other HARPs using different methods.
However, due to the heterogeneity of the C-terminally labeled AaRP (ORF Aq880), we were
unable to solve the structure of AaRP by X-ray crystallography or cryo-electron microscopy
(cryo-EM). However, mass photometric data revealed that the homologous recombinant
protein of the bacterium Halorhodospira! halophila (ORF Hhal2243) assemble into a
homogeneous structure, in contrast to Aq880. Hence, the apo structure of the bacterial
HARP from H.! halophila! could be solved with 3.37 Å by cryo-EM. It turned out that the
monomeric protein (~24 kDa) forms a homo dodecamer via a screw-like assembly. Due to
steric reasons, higher oligomers are excluded. Two Hhal2243 monomers form a stable dimer
via association of their spike-helix (SH) domains"consisting of helices alpha5 and alpha6, resulting
in a 4-helix bundle. Thus, a total of six such helix bundles protrude from the dodecameric
structure. The protruding spike helices of HARP dimers make a major contribution to
substrate binding through interaction with the conserved elbow region of tRNAs. A proposed
docking model predicts that the 5’-leader to be processed would then reach into the active
centre of the neighbouring dimer, suggesting that a tetramer represents the smallest
functional unit for cleavage of pre-tRNA substrates. The solved cryo-EM structure provides
an important basis for future studies aiming at the biological and mechanistic understanding
of pre-tRNA processing by prokaryotic HARPs
Extended Reality-Based Head-Mounted Displays for Surgical Education: A Ten-Year Systematic Review
No full textSurgical education demands extensive knowledge and skill acquisition within limited time frames, often limited by reduced training opportunities and high-pressure environments. This review evaluates the effectiveness of extended reality-based head-mounted display (ExR-HMD) technology in surgical education, examining its impact on educational outcomes and exploring its strengths and limitations. Data from PubMed, Cochrane Library, Web of Science, ScienceDirect, Scopus, ACM Digital Library, IEEE Xplore, WorldCat, and Google Scholar (Year: 2014–2024) were synthesized. After screening, 32 studies comparing ExR-HMD and traditional surgical training methods for medical students or residents were identified. Quality and bias were assessed using the Medical Education Research Study Quality Instrument, Newcastle–Ottawa Scale-Education, and Cochrane Risk of Bias Tools. Results indicate that ExR-HMD offers benefits such as increased immersion, spatial awareness, and interaction and supports motor skill acquisition theory and constructivist educational theories. However, challenges such as system fidelity, operational inconvenience, and physical discomfort were noted. Nearly half the studies reported outcomes comparable or superior to traditional methods, emphasizing the importance of social interaction. Limitations include study heterogeneity and English-only publications. ExR-HMD shows promise but needs educational theory integration and social interaction. Future research should address technical and economic barriers to global accessibility.Gefördert durch den Open-Access-Publikationsfonds der UB Marburg
Überleben von Patienten mit duktalem Adenokarzinom des Pankreas: Korrelation mit Veränderungen auf molekularer Ebene
No full textPancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer-related deaths in western industrialized nations. The low 5-year survival rate of 18.8% 21 can be explained by the lack of diagnostic options and therapeutic strategies. Therefore, research into prognostic and therapeutic approaches is becoming increasingly important. Changes at the molecular level have been observed in tumor cells and the tumor microenvironment. However, only few data are available showing the impact of these changes on patient survival. The focus of this work was to generate survival data from 91 PDAC patients treated in our department.
For this purpose, exosomes were purified from patient samples. Their size and concentration were measured using nano-flow cytometry (FCM). However, the determined distribution could not be linked to an overall survival pattern.
From our data, the median survival is 21 months after diagnosis of Pancreatic cancer (PC). Patients assigned to the short-term survival group (≤21 months) were predominantly of high tumor stage according to the 2017 UICC-TNM (Union for International 64 Cancer Control; tumor, node, metastasis) classification.
PCR and Western Blotting were used to display the expression patterns of tetraspanins CD9 and CD81 in EVs derived from pancreatic tumor cells.
For both CD9 and CD81, an inverse correlation was shown between strong expression levels and poor prognosis of PDAC patients after complete surgical resection (R0). However, only the CD9 data could show a significant difference, while for future projects a larger cohort of patients would be interesting for CD81 to obtain significant results.
PCR followed by immunohistochemical staining was used to describe the distribution pattern and expression levels of ADAM8, PRMT1 and TLR-7 in tumor cells its surrounding stromal cells from over 70 PDAC patients.
In addition, the amount of ADAM8+ neutrophils in the postcapillary venules in PDAC sections was quantified. Remarkably, the amount of ADAM8+ neutrophils could be correlated with post-operative patient survival time. In contrast, no linkage could be shown between survival time and overall ADAM8 expression levels.
While high PRMT1 protein expression levels were shown to be favorable for the prognostic outcome of patients, TLR-7 was over-expressed in samples from patients with short survival time.
From our observations, we conclude that changes in tumor cells and their micromilieu-specific stromal cells at the molecular level have a remarkable impact on the overall survival of PDAC patients.
Therefor they show prognostic potential and could be an interesting target for therapeutic approaches.Das duktale Adenokarzinom des Pankreas (PDAC) gehört zu den führenden krebsbedingten Todesursachen in westlichen Industrienationen. Die niedrige 5-Jahres-Überlebensrate von 18,8% 21 ist durch fehlende Möglichkeiten zur diagnostischen Früherkennung und schlechten Therapie-Optionen zu erklären. Daher gewinnt die Forschung an prognostischen und therapeutischen Ansätzen zunehmend an Bedeutung. Veränderungen auf molekularer Ebene konnten in Tumorzellen und der Tumor-Mikroumgebung beobachtet werden. Es liegen jedoch nur wenige Daten vor, welche die Auswirkung dieser Veränderungen auf das Überleben der Patienten zeigen. Der Schwerpunkt dieser Arbeit lag auf der Erstellung von Überlebensdaten von 91 PDAC-Patienten, die in unserer Abteilung behandelt wurden.
Dafür wurden Exosomen aus Patientenserumproben extrahiert. Mittels Nano-Durchflusszytometrie (FCM) wurden Größe und Konzentration gemessen. Die ermittelte Verteilung konnte allerdings nicht mit einem Gesamtüberlebensmuster verknüpft werden.
Aus unseren Daten geht hervor, dass die mittlere Überlebensdauer bei 21 Monaten, nach Stellung der Diagnose, liegt. Patienten, die der Gruppe mit kurzem Überleben (≤ 21 Monate) zugeordnet wurden, weisen laut UICC-TNM (Union for International 64 Cancer Control; Tumor, Knoten, Metastasen) Klassifikation 2017 überwiegend ein hohes Tumorstadium auf.
Expressionsmuster der Tetraspanine CD9 und CD81 in EVs, die von Pankreastumorzellen stammen, wurden mit Hilfe von PCR und Western Blot dargestellt.
Sowohl für CD9 als auch CD81 zeigte sich ein umgekehrter Zusammenhang zwischen starken Expressionsniveaus und schlechter Prognose von PDAC-Patienten nach vollständiger chirurgischer Resektion (R0). Jedoch konnten nur die Daten von CD9 einen signifikanten Unterschied zeigen, während für zukünftige Projekte eine größere Kohorte von Patienten für CD81 interessant wäre, um signifikante Ergebnisse hervorzubringen.
Mit Hilfe von PCR und anschließender immunhistochemischer Färbung wurde das Verteilungsmuster und die Expressionsstärke von ADAM8, PRMT1 und TLR-7 in Tumorzellen und der umgebenen Stroma Zellen von über 70 PDAC-Patienten beschrieben.
Außerdem wurde die Menge an ADAM8+ Neutrophilen in den postkapillären Venolen in PDAC-Schnitten quantifiziert. Bemerkenswert ist die Korrelation von ADAM8+ Neutrophilen zu der postoperativen Überlebenszeit der Patienten. Im Gegensatz dazu konnte kein Zusammenhang zwischen der Überlebenszeit und der Gesamtmenge an ADAM8-Expression nachgewiesen werden.
Während sich hohe PRMT1-Proteinexpressionwerte als günstig für das prognostische Ergebnis der Patienten zeigte, war TLR-7 in Proben von Patienten mit kurzer Überlebenszeit überexprimiert.
Aus unseren Beobachtungen schließen wir auf einen bemerkenswerten Einfluss auf das Gesamtüberleben von PDAC-Patienten, die Veränderungen in Tumorzellen und ihrem mikromilieuspezifischen Stroma-Zellen auf molekularer Ebene haben. Dadurch stellen sie für weitere Forschung ein interessantes Ziel für prognostische Marker und therapeutische Angriffspunkte dar