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The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points.
The article presents an analysis of the development of labour market risks in Germany in light of changing working poverty risks. Low hourly wages and part-time employment are identified as the main demand-side-related mechanisms for household poverty. Their measurement and development are discussed as well as their contribution to trends in working poverty risks. A rise in low wages, especially among part-time employed households, was decisive for the increase in working poverty risks in Germany by 45% between the end of the 1990s and the end of the 2000s. We therefore study these trends more closely in the multivariate analysis. The results show that while low wages are unequally distributed across occupations and industries, shifts in employment between sectors explain only a minor part of the change in low wages. However, they reveal a polarization of low-wage risks by skill-level and sector of employment, on the one hand, and full-time and part-time employees, on the other hand.
Several peptides in clinical use are derived from non-ribosomal peptide synthetases (NRPS). In these systems multiple NRPS subunits interact with each other in a specific linear order mediated by specific docking domains (DDs), whose structures are not known yet, to synthesize well-defined peptide products. In contrast to classical NRPSs, single-module NRPS subunits responsible for the generation of rhabdopeptide/xenortide-like peptides (RXPs) can act in different order depending on subunit stoichiometry thereby producing peptide libraries. To define the basis for their unusual interaction patterns, we determine the structures of all N-terminal DDs (NDDs) as well as of an NDD-CDD complex and characterize all putative DD interactions thermodynamically for such a system. Key amino acid residues for DD interactions are identified that upon their exchange change the DD affinity and result in predictable changes in peptide production. Recognition rules for DD interactions are identified that also operate in other megasynthase complexes.
The interaction of trimethyl(methylcyclopentadienyl)platinum(IV) ((C5H4CH3)Pt(CH3)3) molecules on fully and partially hydroxylated SiO2 surfaces, as well as the dynamics of this interaction were investigated using density functional theory (DFT) and finite temperature DFT-based molecular dynamics simulations. Fully and partially hydroxylated surfaces represent substrates before and after electron beam treatment and this study examines the role of electron beam pretreatment on the substrates in the initial stages of precursor dissociation and formation of Pt deposits. Our simulations show that on fully hydroxylated surfaces or untreated surfaces, the precursor molecules remain inactivated while we observe fragmentation of (C5H4CH3)Pt(CH3)3 on partially hydroxylated surfaces. The behavior of precursor molecules on the partially hydroxylated surfaces has been found to depend on the initial orientation of the molecule and the distribution of surface active sites. Based on the observations from the simulations and available experiments, we discuss possible dissociation channels of the precursor.
The tumor vasculature differs from normal blood vessels in morphology, composition and stability. Here, we describe a novel tumor vessel-disrupting mechanism. In an HT1080/mouse xenograft tumor model rhodocetin-αβ was highly effective in disrupting the tumor endothelial barrier. Mechanistically, rhodocetin-αβ triggered MET signaling via neuropilin-1. As both neuropilin-1 and MET were only lumen-exposed in a subset of abnormal tumor vessels, but not in normal vessels, the prime target of rhodocetin-αβ were these abnormal tumor vessels. Consequently, cells lining such tumor vessels became increasingly motile which compromised the vessel wall tightness. After this initial leakage, rhodocetin-αβ could leave the bloodstream and reach the as yet inaccessible neuropilin-1 on the basolateral side of endothelial cells and thus disrupt nearby vessels. Due to the specific neuropilin-1/MET co-distribution on cells lining such abnormal tumor vessels in contrast to normal endothelial cells, rhodocetin-αβ formed the necessary trimeric signaling complex of rhodocetin-αβ-MET-neuropilin-1 only in these abnormal tumor vessels. This selective attack of tumor vessels, sparing endothelial cell-lined vessels of normal tissues, suggests that the neuropilin-1-MET signaling axis may be a promising drugable target for anti-tumor therapy, and that rhodocetin-αβ may serve as a lead structure to develop novel anti-tumor drugs that target such vessels.
Despite a large body of research, the linguistic nature of exhaustivity in single wh-questions is unresolved. Moreover, little empirical evidence exists as to which related structures pattern with bare wh-questions regarding exhaustivity. This paper explores the felicity of various exhaustivity violations in unembedded single bare wh-questions in German and compares them to related structures. In two novel felicity judgment experiments, a total of 441 participants rated exhaustive as well as non-exhaustive plural and non-exhaustive singleton answers to wh-questions or statements in a questionnaire. Answers were based on picture stimuli depicting individuals performing various actions. The felicity of non-exhaustive answers was compared across four main test conditions: bare wh-questions (wer ‘who’), wh-questions with a lexical exhaustivity marker (wer alles ‘who all’), plural definite descriptions contained in a restrictive relative clause (e.g., “the people who are fishing in the garden”), and the scalar quantifier “some” (e.g., “some people who are fishing in the garden”).
We employ a novel methodological approach to improve the interpretability of statistical differences between experimental conditions by using the statistical measure of Minimal Important Difference (MID). Our results from estimated MIDs reveal that adults’ felicity judgments of non-exhaustive plural answers to bare wh-questions pattern with those to wer alles-questions and to plural definite descriptions: exhaustivity violations in the bare wh, the wer alles and the plural definite conditions were rated as less felicitous than exhaustivity violations in the some-condition.
Heat stress transcription factors (Hsfs) are required for transcriptional changes during heat stress (HS) thereby playing a crucial role in the heat stress response (HSR). The target genes of Hsfs include heat shock proteins (Hsps), other Hsfs and genes involved in protection of the cell from irreversible damages due to exposure to elevated temperatures. Among 27 Hsfs in Solanum lycopersicum, HsfA1a, HsfA2 and HsfB1 constitute a functional triad which regulates important aspects of the HSR. HsfA1a is constitutively expressed and described as the master regulator of stress response and thermotolerance. Activation of HsfA1a under elevated temperatures leads to the induction of HsfA2 and HsfB1 which further stimulate the transcription of HS-responsive genes by forming highly active complexes with HsfA1a. Despite the well-established role of these three Hsfs in tomato HSR, information about functional relevance of other Hsfs is currently missing.
The heat stress inducible HsfA7 belongs alongside with HsfA2 to a phylogenetically distinct clade. Thereby the two proteins share high homology and a functional redundancy has been assumed. However, HsfA7 function and contribution to stress responses have not been investigated into detail in any plant species.
Tomato HsfA7 protein accumulates already at moderately elevated temperatures (~35°C) while HsfA2 becomes dominant at higher temperatures (>40°C). HsfA7 pre-mRNA undergoes complex and temperature-dependent alternative splicing resulting in several transcripts that encode for three protein isoforms. HsfA7-I contains a functional nuclear export signal (NES) and shows nucleocytoplasmic shuttling while HsfA7-II and HsfA7-III have a truncated NES which leads to the strong nuclear retention of the protein. Differences in the nucleocytoplasmic equilibrium have a major impact on the stability of protein isoforms, as nuclear retention is associated with increased protein turnover. Consequently, HsfA7-I shows a higher stability and can be detected even after 24 hours of stress attenuation, while HsfA7-II is rapidly degraded. The degradation of these factors is mediated by the ubiquitin-proteasome pathway.
HsfA7 can physically interact with HsfA1a and HsfA3 and form co-activator (“superactivator”) complexes with a very high transcriptional activity as shown on different HS-inducible promoters. In order for the complex to be successfully transferred to the nucleus and confer its activity it needs a functional nuclear localization signal (NLS) of HsfA7. In contrast, the activator (AHA) motif of HsfA7 is not essential for its co-activator function. Interestingly, while interaction of HsfA7 with either HsfA3 or HsfA1a stabilizes HsfA7 isoforms, concomitantly this leads to an increased turnover of HsfA1a and HsfA3. In contrast, HsfA2 has a stabilizing effect on the master regulator HsfA1a.
Thus, HsfA7 knockout mutants generated by CRISPR/Cas9 gene editing, show increased HsfA1a levels and a stronger induction of HS-related genes at 35°C compared to wild-type plants and HsfA2 knockout mutants. Consequently, HsfA7 knockout seedlings exhibit increased thermotolerance as shown by the enhanced hypocotyl elongation under a prolonged mild stress treatment at 35°C. In summary, these results highlight the importance of HsfA7 in regulation of cellular responses at elevated temperatures. Under moderately elevated temperatures, the accumulation of HsfA7 and its subsequent interaction with HsfA1a, leads to increased turnover of the latter, thereby ensuring a milder transcriptional activation of temperature-responsive genes like Hsps. In turn, in response to further elevated temperatures, HsfA2 becomes the dominant stress-induced Hsf. HsfA2 forms co-activator complexes with HsfA1a which in contrast to HsfA7, allows the stabilization of the master regulator, leading to the stronger expression of HS-responsive genes required for survival. Thereby, this study uncovers a new regulatory mechanism, where the temperature-dependent competitive interaction of HsfA2 and HsfA7 with HsfA1a control the fate of the master regulator and consequently the activity of temperature-responsive networks.
In recent years, experimental research has demontrated great variability in the rates of scalar inferences across different triggering expressions (Doran et al. 2009, 2012, van Tiel et al. 2016). These studies have been taken as evidence against the so-called uniformity assumption, which posits that scalar implicature is triggered by a single mechanism and that the behaviour of one scale should generalize to the whole family of scales. In the following, we present an experimental study that tests negative strengthening for a variety of strong scalar terms, following up on van Tiel et al. (2016). For example, we tested whether the statement John is not brilliant is strengthened to mean that John is not intelligent (see especially Horn 1989). We show that endorsement rates of the scalar implicature (e.g., John is intelligent but not brilliant) are anti-correlated with endorsements of negative strengthening. Further, we demonstrate that a modified version of the uniformity hypothesis taking into account negative strengthening is consistent with van Tiel et al.’s data. Therefore, variation across scales may be more systematic than suggested by the van Tiel et al. study.
Miners and modals
(2018)
I generalise Kolodny and MacFarlane’s miners puzzle by showing epistemic analogues of their case exist. After motivating various conservative approaches to the original problem, I show how they fail to solve the problem in its epistemic guise. I argue that a probabilistic approach to information-sensitivity gives a general solution to the problem.
Wie Hashtags bei Twitter als Teile von Komposita verwendet werden, zeigt Markus Majewski in seinem Beitrag #Erdogan-Diktatur - Hashtags als Elemente von Substantivkomposita in politischen Tweets. Als Grundlage dient ihm das Korpus aus Tweets von SpitzenpolitikerInnen der großen Parteien während des Wahlkampfs, in dem er alle Substantivkomposita mit einem Hashtag als Bestandteil wie #Energiewende auf funktionale, graphematische und strukturelle Aspekte untersucht. Insbesondere bei der Schreibung der Komposita zeigt sich eine große Kreativität. Zudem lassen sich Twitter-spezifische Kommunikationsfunktionen der Hashtag-Erstglieder beobachten.
In these volumes, we are very pleased to present a collection of papers based on talks and posters at Sinn und Bedeutung 22, which took place in Berlin and Potsdam on September 7-10, 2017, jointly organized by the Leibniz-Centre for General Linguistics (ZAS) and the University of Potsdam.
SuB22 received 183 submitted abstracts. Out of these, the organizing committee selected 39 oral presentations in the main session, 4 oral presentations in the special session ‘Semantics and Natural Logic’, and 24 poster presentations. There were an additional 6 invited talks. In total, 58 of these contributions appear in paper form in the present volumes.
With a notional amount outstanding of more than USD 500 trillion, the market for OTC derivatives is of vital importance for global financial stability. A growing proportion of these contracts are cleared via central counterparties (CCPs), which means that CCPs are gaining in importance as critical financial market infrastructures. At the same time, there is growing concern that a new „too big to fail" problem could arise, as the CCP industry is highly concentrated due to economies of scale. From a European perspective, it should be noted that the clearing of euro-denominated OTC derivatives mainly takes place in London, hence outside the EU in the foreseeable future. For some time there has been a controversial discussion as to whether this can remain the case post Brexit. CCPs, which clear a significant proportion of euro OTC derivatives and are systemically relevant from an EU perspective, should be subject to direct supervision by EU authorities and should be established in the EU. This would represent an important building block for a future Capital Markets Union in Europe, as regulatory or supervisory arbitrage in favour of systemically important third-country CCPs could be prevented. In addition, if a systemically relevant CCP handling a considerable portion of the euro OTC derivatives business were to run into serious difficulties, this may impact ECB monetary policy. This applies both to demand for central bank money and to the transmission of monetary policy measures, which can be significantly impaired, particularly in the event that the repo market or payment systems are disrupted. It is therefore essential for the ECB to be closely involved in the supervision of CCPs. Against this background, the draft amendment of EMIR (European Market Infrastructure Regulation) presented on 13 June 2017 is a step in the right direction. In addition, there is an urgent need to introduce a recovery and resolution mechanism for CCPs in the EU to complement the existing single resolution mechanism (SRM) for banks in the eurozone. Only then can the diverse interdependencies between banks and CCPs be adequately taken into account in the recovery and resolution programmes required in a financial crisis.
Background: Alternative splicing is a key mechanism in eukaryotic cells to increase the effective number of functionally distinct gene products. Using bulk RNA sequencing, splicing variation has been studied both across human tissues and in genetically diverse individuals. This has identified disease-relevant splicing events, as well as associations between splicing and genomic variations, including sequence composition and conservation. However, variability in splicing between single cells from the same tissue and its determinants remain poorly understood.
Results: We applied parallel DNA methylation and transcriptome sequencing to differentiating human induced pluripotent stem cells to characterize splicing variation (exon skipping) and its determinants. Our results shows that splicing rates in single cells can be accurately predicted based on sequence composition and other genomic features. We also identified a moderate but significant contribution from DNA methylation to splicing variation across cells. By combining sequence information and DNA methylation, we derived an accurate model (AUC=0.85) for predicting different splicing modes of individual cassette exons. These explain conventional inclusion and exclusion patterns, but also more subtle modes of cell-to-cell variation in splicing. Finally, we identified and characterized associations between DNA methylation and splicing changes during cell differentiation.
Conclusions: Our study yields new insights into alternative splicing at the single-cell level and reveals a previously underappreciated component of DNA methylation variation on splicing.
We use 4stout improved staggered lattice data at imaginary chemical potentials to calculate fugacity expansion coefficients in finite temperature QCD. We discuss the phenomenological interpretation of our results within the hadron resonance gas (HRG) model, and the hints they give us about the hadron spectrum. We also discuss features of the higher order coefficients that are not captured by the HRG. This conference contribution is based on our recent papers [1, 2].
The production of Σ0 baryons in the nuclear reaction p (3.5 GeV) + Nb (corresponding to sNN=3.18 GeV) is studied with the detector set-up HADES at GSI, Darmstadt. Σ0s were identified via the decay Σ0→Λγ with subsequent decays Λ→pπ− in coincidence with a e+e− pair from either external (γ→e+e−) or internal (Dalitz decay γ⁎→e+e−) gamma conversions. The differential Σ0 cross section integrated over the detector acceptance, i.e. the rapidity interval 0.5<y<1.1, has been extracted as ΔσΣ0=2.3±(0.2)stat±(−0.6+0.6)sys±(0.2)norm mb, yielding the inclusive production cross section in full phase space σΣ0total=5.8±(0.5)stat±(−1.4+1.4)sys±(0.6)norm±(1.7)extrapol mb by averaging over different extrapolation methods. The Λall/Σ0 ratio within the HADES acceptance is equal to 2.3±(0.2)stat±(−0.6+0.6)sys. The obtained rapidity and momentum distributions are compared to transport model calculations. The Σ0 yield agrees with the statistical model of particle production in nuclear reactions. Keywords: Hyperons, Strangeness, Proton, Nucleus.
We present data on charged kaons (K±) and ϕ mesons in Au(1.23A GeV)+Au collisions. It is the first simultaneous measurement of K− and ϕ mesons in central heavy-ion collisions below a kinetic beam energy of 10A GeV. The ϕ/K− multiplicity ratio is found to be surprisingly high with a value of 0.52±0.16 and shows no dependence on the centrality of the collision. Consequently, the different slopes of the K+ and K− transverse-mass spectra can be explained solely by feed-down, which substantially softens the spectra of K− mesons. Hence, in contrast to the commonly adapted argumentation in literature, the different slopes do not necessarily imply diverging freeze-out temperatures of K+ and K− mesons caused by different couplings to baryons.
We present a measurement of inclusive J /ψ production at mid-rapidity (|y| < 1) in p+p collisions at a center-of-mass energy of √s = 200 GeV with the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The differential production cross section for J /ψ as a function of transverse momentum (p T ) for 0 < p T < 14 GeV/c and the total cross section are reported and compared to calculations from the color evaporation model and the non-relativistic Quantum Chromodynamics model. The dependence of J /ψ relative yields in three p T intervals on charged-particle multiplicity at mid-rapidity is measured for the first time in p+p collisions at √s = 200 GeV and compared with that measured at √s = 7 TeV, PYTHIA8 and EPOS3 Monte Carlo generators, and the Percolation model prediction.
n this article we will focus on the appearance of the hadron-quark phase transition and the formation of strange matter in the interior region of the hypermassive neutron star and its conjunction with the spectral properties of the emitted gravitational waves (GWs). A strong hadron-quark phase transition might give rise to a mass-radius relation with a twin star shape and we will show in this article that a twin star collapse followed by a twin star oscillation is feasible. If such a twin star collapse would happen during the postmerger phase it will be imprinted in the GW-signal.
The transversity distribution, which describes transversely polarized quarks in transversely polarized nucleons, is a fundamental component of the spin structure of the nucleon, and is only loosely constrained by global fits to existing semi-inclusive deep inelastic scattering (SIDIS) data. In transversely polarized p↑+p collisions it can be accessed using transverse polarization dependent fragmentation functions which give rise to azimuthal correlations between the polarization of the struck parton and the final state scalar mesons.This letter reports on spin dependent di-hadron correlations measured by the STAR experiment. The new dataset corresponds to 25 pb−1 integrated luminosity of p↑+p collisions at s=500 GeV, an increase of more than a factor of ten compared to our previous measurement at s=200 GeV. Non-zero asymmetries sensitive to transversity are observed at a Q2 of several hundred GeV and are found to be consistent with the former measurement and a model calculation. We expect that these data will enable an extraction of transversity with comparable precision to current SIDIS datasets but at much higher momentum transfers where subleading effects are suppressed.