Refine
Year of publication
Document Type
- Article (307)
- Preprint (139)
- Book (2)
- Doctoral Thesis (1)
Has Fulltext
- yes (449)
Is part of the Bibliography
- no (449)
Keywords
- BESIII (15)
- Branching fraction (9)
- e +-e − Experiments (9)
- LHC (7)
- Quarkonium (6)
- Hadronic decays (5)
- Particle and Resonance Production (5)
- Branching fractions (4)
- Lepton colliders (4)
- ALICE (3)
Institute
- Physik (359)
- Frankfurt Institute for Advanced Studies (FIAS) (107)
- Informatik (61)
- Medizin (29)
- Geowissenschaften (6)
- Buchmann Institut für Molekulare Lebenswissenschaften (BMLS) (4)
- Biochemie, Chemie und Pharmazie (3)
- ELEMENTS (3)
- Biowissenschaften (2)
- Extern (2)
Staphylococcus aureus proteins Sbi and Efb recruit human plasmin to degrade complement C3 and C3b
(2012)
Upon host infection, the human pathogenic microbe Staphylococcus aureus (S. aureus) immediately faces innate immune reactions such as the activated complement system. Here, a novel innate immune evasion strategy of S. aureus is described. The staphylococcal proteins surface immunoglobulin-binding protein (Sbi) and extracellular fibrinogen-binding protein (Efb) bind C3/C3b simultaneously with plasminogen. Bound plasminogen is converted by bacterial activator staphylokinase or by host-specific urokinase-type plasminogen activator to plasmin, which in turn leads to degradation of complement C3 and C3b. Efb and to a lesser extend Sbi enhance plasmin cleavage of C3/C3b, an effect which is explained by a conformational change in C3/C3b induced by Sbi and Efb. Furthermore, bound plasmin also degrades C3a, which exerts anaphylatoxic and antimicrobial activities. Thus, S. aureus Sbi and Efb comprise platforms to recruit plasmin(ogen) together with C3 and its activation product C3b for efficient degradation of these complement components in the local microbial environment and to protect S. aureus from host innate immune reactions.
Weltweit stellen die tropischen Tieflandregenwälder die Zentren der Artenvielfalt und Biodiversität dar. Sie sind das komplexeste aller terrestrischen Ökosysteme. Zu der Frage nach den Ursachen ihrer Artenvielfalt und deren Aufrechterhaltung gibt es neben theoretischen Erklärungsansätzen bisher kaum Studien, die versuchen, die Artenvielfalt eines Taxons bedingende ökologischen Faktoren kausal zu untersuchen. Die vorliegende Arbeit hatte zum Ziel, diese Thematik mit Hilfe eines neuen Forschungsansatzes aufzugreifen. Die Artenabnahme eines Taxons und die sie potentiell verursachenden Faktoren sollten entlang eines Höhengradienten aufgenommen werden, um im Umkehrschluß Hinweise zu finden, welche Bedingungen für die Aufrechterhaltung der Artenvielfalt entscheidend sind. Ameisen boten sich aufgrund ihrer starken Artenabnahme mit zunehmender Höhe besonders als Untersuchungsobjekt an. Sie nehmen zudem eine Schlüsselrolle im Ökosystem Tieflandregenwald ein, stellen unter den Invertebraten eine der taxonomisch mit am besten bearbeiteten Gruppen dar, und selbst einzelne Individuen können aufgrund ihrer eusozialen und seßhaften Lebensweise definitiv dem Fundort bzw. der Fundhöhe zugeordnet werden. Der grundlegende Versuchsansatz bestand darin, alle Untersuchungen vergleichend in Boden- und Vegetationsstratum durchzuführen. Dementsprechend wurden entlang des Höhengradienten in beiden Straten die Artenabnahme der Ameisen sowie abiotische und biotische Parameter aufgenommen. Weiterhin wurde eine Art (Diacamma sp.) exemplarisch herausgegriffen, um eventuelle Veränderungen ihrer Ökologie zu erfassen. Die Abnahme der Artenvielfalt von Ameisen am Boden und in der niederen Vegetation verläuft unterschiedlich. Dieser Unterschied ist jedoch nicht auf grundlegend unterschiedliche Faktoren zurückzuführen, sondern auf deren unterschiedliche Ausprägung entlang des Höhengradienten. Es handelt sich hier in beiden Straten zusammenfassend vor allem um vier Faktoren: Temperatur, Feuchtigkeit (umfaßt relative Luftfeuchtigkeit, Nebel, Regen und Staunässe), Nistraumverknappung und Nahrungsverknappung. Die in dieser Studie festgestellte signifikant positive Korrelation von Arten- und Temperaturabnahme betont die besondere Bedeutung des Parameters Temperatur. Diese wirkt einerseits durch eine Beeinträchtigung des Stoffwechsels direkt auf adulte Tiere und Brut und andererseits indirekt über die Veränderung abiotischer (Feuchtigkeit und Nistraum) und biotischer (Nahrung) Parameter. Die jeweiligen relativen Anteile von direktem und indirektem Temperatureinfluß, die mit zunehmender Höhe zur Artenabnahme führen, sind mit den vorliegenden Daten nicht quantifizierbar. Zudem verändern sich die Relationen entlang des Höhengradienten. Anhand ökologischer Überlegungen kann dennoch eine Einschätzung der jeweiligen Bedeutung der Einzelfaktoren vorgenommen werden. Der direkte Einfluß von Temperatur wird in der vorliegenden Studie mehrfach verdeutlicht. Diacamma sp. zeigt beispielsweise eine verminderte Leistungsfähigkeit durch eine signifikant geringere Bauaktivität mit steigender Höhe. Zudem scheint Diacamma sp. in der Lage zu sein, die Architektur ihrer Nester so zu verändern, daß sie thermoregulatorisch der Temperaturabnahme entgegenwirkt. Diese ethologische Flexibilität ermöglicht Diacamma sp., ihr Vorkommen über ihre physiologische Toleranz hinaus auszudehnen. Ein weiterer Hinweis auf einen direkten Temperatureinfluß ergibt sich aus der generellen Reduktion der Koloniegrößen mit zunehmender Höhe. Sie könnte unter anderem durch eine verringerte Fouragieraktivität begründet sein. Weiterhin nimmt die Nestdichte in beiden Straten in dem Höhenbereich signifikant ab, in dem die Durchschnittstemperaturen unter den ökologisch für Ameisen kritischen Schwellenwert von 20°C sinken. Der überwiegende Teil der Ameisen beider Straten nistet in thermoregulatorisch ungünstigem Nistraum (z.B. kleines Totholz, Laub, Humusschicht, Karton). Daher kann die Temperaturabnahme direkt zu einer Nistraumverknappung führen. Am Boden hat die temperaturinduzierte Zunahme von Staunässe mit steigender Höhe einen zusätzlichen negativen Effekt auf die Ressource Nistraum. Insbesondere die Schicht, in der die meisten Nester gefunden wurden (Humus-Wurzel-Schicht), ist davon betroffen. Zudem führt die signifikant an Höhe zunehmende Humus-Wurzel-Schicht dazu, daß der Oberboden im Übergang zwischen Tiefland- und unterem Bergregenwald immer weniger als Nistraum zur Verfügung steht. Im Bergregenwald hingegen treten durch vermehrten Epiphytenbewuchs für Bodenameisen neue Nistmöglichkeiten in der niederen Vegetation auf. In der Vegetation werden durch zunehmende Feuchtigkeit die Kartonnester instabil und damit in größeren Höhen unbrauchbar. Zudem trägt die temperaturabhängige Veränderung der Wuchsform des unteren Bergregenwaldes durch eine räumliche Verkleinerung des Gesamtlebensraumes zu einer Reduzierung der Nist- und Nahrungsressourcen bei. Die Nahrungsverfügbarkeit für Ameisen wird am Boden und in der niederen Vegetation ebenfalls negativ von Temperatur und Feuchtigkeit beeinflußt. Am Boden wird die Nahrungsverknappung z.B. durch den signifikant zunehmenden Nistabstand und den signifikant abnehmenden Beuteeintrag / Zeit von Diacamma sp. Kolonien deutlich. Es ist anzunehmen, daß Nahrungsmangel bei ihrer Verbreitungsgrenze von 1050 m eine wichtige Rolle spielt. Die Nahrungsverknappung für die räuberisch lebenden Bodenameisen wird vermutlich vor allem durch die Abnahme wichtiger Beutegruppen (z.B. Termiten) verursacht. Weiterhin hindert (Stau)Nässe kleine Ameisenarten (die große Mehrheit der hier gesammelten Arten) an der Nahrungssuche. In der niederen Vegetation verursacht der Wechsel des Florentyps auf Familienniveau zwischen Tieflandregenwald und Bergregenwald mit großer Wahrscheinlichkeit eine entscheidende Verknappung der Nahrungsressourcen über die Abnahme von Pflanzen mit extrafloralen Nektarien und der mit Ameisen assoziierten Trophobionten. Die Arten- und Abundanzabnahme der Ameisen verstärkt diese Tendenz wiederum durch negative Rückkopplung, da eine geringere Nachfrage das Angebot bzw. die Produktion der Nahrungssubstrate reduziert. Die vorliegenden Ergebnisse geben weiterhin Hinweise, welche Faktoren bei der Faunenverarmung in anthropogen veränderten Habitaten eine wichtige Rolle spielen können. Der größte Teil der Artenvielfalt des untersuchten primären Regenwaldes wird von kleinen Arten gestellt. Diese wiederum weisen in besonderem Maße eine Sensibilität gegenüber mikroklimatischen Veränderungen auf. Insbesondere abiotische Extreme wie Nässe und niedrige Temperaturen oder Trockenheit in Kombination mit hohen Temperaturen sind Faktoren, die sie am Fouragieren und Nisten hindern können. Daher trägt eine gut ausgebildete Laubstreu- bzw. Humusschicht grundsätzlich zur Artenvielfalt der Bodenameisen bei. Die Laubstreuschicht dient als Fouragierstratum, die Humusschicht als Hauptniststratum, und beide zusammen wiederum sind ein Schutz gegen die Austrocknung des Oberbodens. Ihre Bewahrung sowie die eines möglichst ausgewogenen Mikroklimas sind Grundvoraussetzung für die Vermeidung einer Artenverarmung. Für die niedrige Ausbreitungsgrenze von Ameisen an feucht-tropischen Höhengradienten (ca. 2300 m) scheinen spezielle Charakteristika ihrer eusozialen Lebensweise entscheidend zu sein. Hier sind insbesondere die ökologische Notwendigkeit geschützten Nistraums, energieaufwendiger Fouragierleistung und hoher Brut-Entwicklungstemperatur sowie die Unfähigkeit zur aktiven Nest- Temperaturerhöhung zu nennen. Historisch tiergeografische Gründe scheinen für die starke Abnahme der Ameisenvielfalt mit zunehmender Höhe bzw. für ihre Ausbreitungsgrenzen eine eher untergeordnete Rolle zu spielen. Temperaturabnahme allein bedingt jedoch nicht zwingend eine Artenabnahme, wie im unteren Bergregenwald an der gleichbleibenden Artenzahl des Bodenstratums deutlich wird. Die Bodenameisen müssen hier Lösungswege gefunden haben, dauerhaft mit weit unter 20°C liegenden Temperaturen, starker Nässe und geringer Sonneneinstrahlung zurecht zu kommen. Insofern können in den submontanen und montanen Bereichen der Regenwälder Höhenspezialisten vermutet werden, die jedoch nicht die subalpinen Regionen erreichen. Zusammenfassend ist festzuhalten, daß für eine hohe Artenvielfalt von Ameisen eine relativ hohe Temperatur, ausgewogen hohe Feuchtigkeit, Nistraumvielfalt und Nahrungsmenge sowie -qualität von entscheidender Bedeutung sind. Eine nähere experimentelle Analyse ihres jeweiligen relativen Gewichtes und ihrer konkreten Wirkweise auf einzelne Arten bzw. Artengruppen wäre für die Zukunft wünschenswert.
Holocene climate was characterised by variability on multi-centennial to multi-decadal time scales. In central Europe, these fluctuations were most pronounced during winter. Here we present a record of past winter climate variability for the last 10.8 ka based on four speleothems from Bunker Cave, western Germany. Due to its central European location, the cave site is particularly well suited to record changes in precipitation and temperature in response to changes in the North Atlantic realm. We present high-resolution records of δ18O, δ13C values and Mg/Ca ratios. Changes in the Mg/Ca ratio are attributed to past meteoric precipitation variability. The stable C isotope composition of the speleothems most likely reflects changes in vegetation and precipitation, and variations in the δ18O signal are interpreted as variations in meteoric precipitation and temperature. We found cold and dry periods between 8 and 7 ka, 6.5 and 5.5 ka, 4 and 3 ka as well as between 0.7 and 0.2 ka. The proxy signals in the Bunker Cave stalagmites compare well with other isotope records and, thus, seem representative for central European Holocene climate variability. The prominent 8.2 ka event and the Little Ice Age cold events are both recorded in the Bunker Cave record. However, these events show a contrasting relationship between climate and δ18O, which is explained by different causes underlying the two climate anomalies. Whereas the Little Ice Age is attributed to a pronounced negative phase of the North Atlantic Oscillation, the 8.2 ka event was triggered by cooler conditions in the North Atlantic due to a slowdown of the thermohaline circulation.
Holocene climate was characterised by variability on multi-centennial to multi-decadal time scales. In central Europe, these fluctuations were most pronounced during winter. Here we present a new record of past winter climate variability for the last 10.8 ka based on four speleothems from Bunker Cave, Western Germany. Due to its central European location, the cave site is particularly well suited to record changes in precipitation and temperature in response to changes in the North Atlantic realm. We present high resolution records of δ18O, δ13C values and Mg/Ca ratios. We attribute changes in the Mg/Ca ratio to variations in the meteoric precipitation. The stable C isotope composition of the speleothems most likely reflects changes in vegetation and precipitation and variations in the δ18O signal are interpreted as variations in meteoric precipitation and temperature. We found cold and dry periods between 9 and 7 ka, 6.5 and 5.5 ka, 4 and 3 ka as well as between 0.7 to 0.2 ka. The proxy signals in our stalagmites compare well with other isotope records and, thus, seem representative for central European Holocene climate variability. The prominent 8.2 ka event and the Little Ice Age cold events are both recorded in the Bunker cave record. However, these events show a contrasting relationship between climate and δ18O, which is explained by different causes underlying the two climate anomalies. Whereas the Little Ice Age is attributed to a pronounced negative phase of the North Atlantic Oscillation, the 8.2 ka event was triggered by cooler conditions in the North Atlantic due to a slowdown of the Thermohaline Circulation.
Rare copy-number variation (CNV) is an important source of risk for autism spectrum disorders (ASDs). We analyzed 2,446 ASD-affected families and confirmed an excess of genic deletions and duplications in affected versus control groups (1.41-fold, p = 1.0 × 10(-5)) and an increase in affected subjects carrying exonic pathogenic CNVs overlapping known loci associated with dominant or X-linked ASD and intellectual disability (odds ratio = 12.62, p = 2.7 × 10(-15), ∼3% of ASD subjects). Pathogenic CNVs, often showing variable expressivity, included rare de novo and inherited events at 36 loci, implicating ASD-associated genes (CHD2, HDAC4, and GDI1) previously linked to other neurodevelopmental disorders, as well as other genes such as SETD5, MIR137, and HDAC9. Consistent with hypothesized gender-specific modulators, females with ASD were more likely to have highly penetrant CNVs (p = 0.017) and were also overrepresented among subjects with fragile X syndrome protein targets (p = 0.02). Genes affected by de novo CNVs and/or loss-of-function single-nucleotide variants converged on networks related to neuronal signaling and development, synapse function, and chromatin regulation.
At particle collider experiments, elementary particle interactions with large momentum transfer produce quarks and gluons (known as partons) whose evolution is governed by the strong force, as described by the theory of quantum chromodynamics (QCD). The vacuum is not transparent to the partons and induces gluon radiation and quark pair production in a process that can be described as a parton shower. Studying the pattern of the parton shower is one of the key experimental tools in understanding the properties of QCD. This pattern is expected to depend on the mass of the initiating parton, through a phenomenon known as the dead-cone effect, which predicts a suppression of the gluon spectrum emitted by a heavy quark of mass m and energy E, within a cone of angular size m/E around the emitter. A direct observation of the dead-cone effect in QCD has not been possible until now, due to the challenge of reconstructing the cascading quarks and gluons from the experimentally accessible bound hadronic states. We report the first direct observation of the QCD dead-cone by using new iterative declustering techniques to reconstruct the parton shower of charm quarks. This result confirms a fundamental feature of QCD, which is derived more generally from its origin as a gauge quantum field theory. Furthermore, the measurement of a dead-cone angle constitutes a direct experimental observation of the non-zero mass of the charm quark, which is a fundamental constant in the standard model of particle physics.
In particle collider experiments, elementary particle interactions with large momentum transfer produce quarks and gluons (known as partons) whose evolution is governed by the strong force, as described by the theory of quantum chromodynamics (QCD). These partons subsequently emit further partons in a process that can be described as a parton shower which culminates in the formation of detectable hadrons. Studying the pattern of the parton shower is one of the key experimental tools for testing QCD. This pattern is expected to depend on the mass of the initiating parton, through a phenomenon known as the dead-cone effect, which predicts a suppression of the gluon spectrum emitted by a heavy quark of mass mQ and energy E, within a cone of angular size mQ/E around the emitter. Previously, a direct observation of the dead-cone effect in QCD had not been possible, owing to the challenge of reconstructing the cascading quarks and gluons from the experimentally accessible hadrons. We report the direct observation of the QCD dead cone by using new iterative declustering techniques to reconstruct the parton shower of charm quarks. This result confirms a fundamental feature of QCD. Furthermore, the measurement of a dead-cone angle constitutes a direct experimental observation of the non-zero mass of the charm quark, which is a fundamental constant in the standard model of particle physics.
The activation of the transcription factor NF-E2-related factor 2 (Nrf2) maintains cellular homeostasis in response to oxidative stress by the regulation of multiple cytoprotective genes. Without stressors, the activity of Nrf2 is inhibited by its interaction with the Keap1 (kelch-like ECH-associated protein 1). Here, we describe (3S)-1-[4-[(2,3,5,6-tetramethylphenyl) sulfonylamino]-1-naphthyl]pyrrolidine-3-carboxylic acid (RA839), a small molecule that binds noncovalently to the Nrf2-interacting kelch domain of Keap1 with a Kd of ∼6 μm, as demonstrated by x-ray co-crystallization and isothermal titration calorimetry. Whole genome DNA arrays showed that at 10 μm RA839 significantly regulated 105 probe sets in bone marrow-derived macrophages. Canonical pathway mapping of these probe sets revealed an activation of pathways linked with Nrf2 signaling. These pathways were also activated after the activation of Nrf2 by the silencing of Keap1 expression. RA839 regulated only two genes in Nrf2 knock-out macrophages. Similar to the activation of Nrf2 by either silencing of Keap1 expression or by the reactive compound 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid methyl ester (CDDO-Me), RA839 prevented the induction of both inducible nitric-oxide synthase expression and nitric oxide release in response to lipopolysaccharides in macrophages. In mice, RA839 acutely induced Nrf2 target gene expression in liver. RA839 is a selective inhibitor of the Keap1/Nrf2 interaction and a useful tool compound to study the biology of Nrf2.
The ALICE Collaboration reports the first fully-corrected measurements of the N-subjettiness observable for track-based jets in heavy-ion collisions. This study is performed using data recorded in pp and Pb−Pb collisions at centre-of-mass energies of √s=7 TeV and √sNN=2.76\,TeV, respectively. In particular the ratio of 2-subjettiness to 1-subjettiness, τ2/τ1, which is sensitive to the rate of two-pronged jet substructure, is presented. Energy loss of jets traversing the strongly interacting medium in heavy-ion collisions is expected to change the rate of two-pronged substructure relative to vacuum. The results are presented for jets with a resolution parameter of R=0.4 and charged jet transverse momentum of 40≤pT,jet≤60 GeV/c, which constitute a larger jet resolution and lower jet transverse momentum interval than previous measurements in heavy-ion collisions. This has been achieved by utilising a semi-inclusive hadron-jet coincidence technique to suppress the larger jet combinatorial background in this kinematic region. No significant modification of the τ2/τ1 observable for track-based jets in Pb--Pb collisions is observed relative to vacuum PYTHIA6 and PYTHIA8 references at the same collision energy. The measurements of τ2/τ1, together with the splitting aperture angle ΔR, are also performed in pp collisions at √s=7 TeV for inclusive jets. These results are compared with PYTHIA calculations at √s=7 TeV, in order to validate the model as a vacuum reference for the Pb−Pb centre-of-mass energy. The PYTHIA references for τ2/τ1 are shifted to larger values compared to the measurement in pp collisions. This hints at a reduction in the rate of two-pronged jets in Pb--Pb collisions compared to pp collisions.
The pT-differential production cross sections of prompt and non-prompt (produced in beauty-hadron decays) D mesons were measured by the ALICE experiment at midrapidity (|y|<0.5) in proton--proton collisions at s√=5.02 TeV. The data sample used in the analysis corresponds to an integrated luminosity of (19.3±0.4) nb−1. D mesons were reconstructed from their decays D0→K−π+, D+→K−π+π+, and D+s→ϕπ+→K−K+π+ and their charge conjugates. Compared to previous measurements in the same rapidity region, the cross sections of prompt D+ and D+s mesons have an extended pT coverage and total uncertainties reduced by a factor ranging from 1.05 to 1.6, depending on pT, allowing for a more precise determination of their pT-integrated cross sections. The results are well described by perturbative QCD calculations. The fragmentation fraction of heavy quarks to strange mesons divided by the one to non-strange mesons, fs/(fu+fd), is compatible for charm and beauty quarks and with previous measurements at different centre-of-mass energies and collision systems. The bb¯¯¯ production cross section per rapidity unit at midrapidity, estimated from non-prompt D-meson measurements, is dσbb¯¯¯/dy||y|<0.5=34.5±2.4(stat.)+4.7−2.9(tot.syst.) μb. It is compatible with previous measurements at the same centre-of-mass energy and with the cross section predicted by perturbative QCD calculations.
The pT-differential production cross sections of prompt and non-prompt (produced in beauty-hadron decays) D mesons were measured by the ALICE experiment at midrapidity (|y|<0.5) in proton--proton collisions at s√=5.02 TeV. The data sample used in the analysis corresponds to an integrated luminosity of (19.3±0.4) nb−1. D mesons were reconstructed from their decays D0→K−π+, D+→K−π+π+, and D+s→ϕπ+→K−K+π+ and their charge conjugates. Compared to previous measurements in the same rapidity region, the cross sections of prompt D+ and D+s mesons have an extended pT coverage and total uncertainties reduced by a factor ranging from 1.05 to 1.6, depending on pT, allowing for a more precise determination of their pT-integrated cross sections. The results are well described by perturbative QCD calculations. The fragmentation fraction of heavy quarks to strange mesons divided by the one to non-strange mesons, fs/(fu+fd), is compatible for charm and beauty quarks and with previous measurements at different centre-of-mass energies and collision systems. The bb¯¯¯ production cross section per rapidity unit at midrapidity, estimated from non-prompt D-meson measurements, is dσbb¯¯¯/dy||y|<0.5=34.5±2.4(stat.)+4.7−2.9(tot.syst.) μb. It is compatible with previous measurements at the same centre-of-mass energy and with the cross section predicted by perturbative QCD calculations.
Inclusive ψ(2S) production is measured in p-Pb collisions at the centre-of-mass energy per nucleon-nucleon pair sNN−−−√=8.16 TeV, using the ALICE detector at the CERN LHC. The production of ψ(2S) is studied at forward (2.03<ycms<3.53) and backward (−4.46<ycms<−2.96) centre-of-mass rapidity and for transverse momentum pT < 12 GeV/c via the decay to muon pairs. In this paper, we report the integrated as well as the ycms- and pT-differential inclusive production cross sections. Nuclear effects on ψ(2S) production are studied via the determination of the nuclear modification factor that shows a strong suppression at both forward and backward centre-of-mass rapidities. Comparisons with corresponding results for inclusive J/ψ show a similar suppression for the two states at forward rapidity (p-going direction), but a stronger suppression for ψ(2S) at backward rapidity (Pb-going direction). As a function of pT, no clear dependence of the nuclear modification factor is found. The relative size of nuclear effects on ψ(2S) production compared to J/ψ is also studied via the double ratio of production cross sections [σψ(2S)/σJ/ψ]pPb/[σψ(2S)/σJ/ψ]pp between p-Pb and pp collisions. The results are compared with theoretical models that include various effects related to the initial and final state of the collision system and also with previous measurements at sNN−−−√ = 5.02 TeV.
J/ψ production as a function of charged-particle multiplicity in p–Pb collisions at √sNN = 8.16 TeV
(2020)
Inclusive J/ψ yields and average transverse momenta in p-Pb collisions at a center-of-mass energy per nucleon pair sNN−−−√ = 8.16 TeV are measured as a function of the charged-particle pseudorapidity density with ALICE. The J/ψ mesons are reconstructed at forward (2.03<ycms<3.53) and backward (−4.46<ycms<−2.96) center-of-mass rapidity in their dimuon decay channel while the charged-particle pseudorapidity density is measured around midrapidity. The J/ψ yields at forward and backward rapidity normalized to their respective average values increase with the normalized charged-particle pseudorapidity density, the former showing a weaker increase than the latter. The normalized average transverse momenta at forward and backward rapidity manifest a steady increase from low to high charged-particle pseudorapidity density with a saturation beyond the average value.
J/ψ production as a function of charged-particle multiplicity in p–Pb
collisions at √sNN = 8.16 TeV
(2021)
Inclusive J/ψ yields and average transverse momenta in p-Pb collisions at a center-of-mass energy per nucleon pair sNN−−−√ = 8.16 TeV are measured as a function of the charged-particle pseudorapidity density with ALICE. The J/ψ mesons are reconstructed at forward (2.03<ycms<3.53) and backward (−4.46<ycms<−2.96) center-of-mass rapidity in their dimuon decay channel while the charged-particle pseudorapidity density is measured around midrapidity. The J/ψ yields at forward and backward rapidity normalized to their respective average values increase with the normalized charged-particle pseudorapidity density, the former showing a weaker increase than the latter. The normalized average transverse momenta at forward and backward rapidity manifest a steady increase from low to high charged-particle pseudorapidity density with a saturation beyond the average value.
The elliptic-flow ratio of neutrons with respect to protons or light complex particles in reactions of heavy ions at pre-relativistic energies has been proposed as an observable sensitive to the strength of the symmetry term of the nuclear equation of state at supra-saturation densities. In the ASY-EOS experiment at the GSI laboratory, flows of neutrons and light charged particles were measured for 197Au+197Au collisions at 400 MeV/nucleon. Flow results obtained for the Au+Au system, in comparison with predictions of the UrQMD transport model, confirm the moderately soft to linear density dependence of the symmetry energy deduced from the earlier FOPI-LAND data.
The pathophysiological role of neural autoantibodies in acute psychotic disorders is receiving increased attention. However, there is still an ongoing debate, whether predominantly psychotic manifestations of autoimmune encephalitides exist that may remain undetected and, thus, untreated. Furthermore, it is discussed if such conditions can be diagnosed based on serum antibody results or if a reliable diagnosis requires additional cerebrospinal fluids (CSF) results. In this study, we screened pairs of serum and CSF samples from antipsychotic-naïve individuals with first-episode schizophrenic psychosis (FEP, n = 103), clinical high risk for psychosis (CHR, n = 47), and healthy volunteers (HV, n = 40) for eight different antibodies against various antigens that have been shown to be associated with autoimmune encephalitides: N-methyl-D-aspartate receptor (NMDAR, NR1 subunits only), glutamic acid decarboxylase (GAD65), leucine-rich glioma inactivated protein 1 (LGI1), contactin-associated protein-like 2 protein (CASPR2), α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) subunit 1, AMPAR subunit 2, γ-aminobutyric acid-B receptors (GABABR), and glycine receptors. All patients were within the norm with regards to a careful neurological examination, a magnetic resonance imaging (MRI) of the brain, an electroencephalogram (EEG), and routine blood pathology. All CSF samples were autoantibody-negative. In three serum samples of individuals with FEP, we detected low-titer CASPR2 immunoglobulin (Ig) G antibodies (≤1:160, n = 2) and non-IgG antibodies against NMDAR (n = 1) (overall serum-autoantibody prevalence in FEP: 2.91%). However, the IgG titers were below the laboratory cut-off defined for positivity, and non-IgG antibodies are of no clinical relevance. This suggests that there were no cases of autoimmune encephalitis in our cohort. Our results highlight the importance and the high specificity of CSF analysis to reliably detect autoantibodies. They confirm the hypothesis that pure psychotic manifestations of antibody-associated autoimmune encephalitides without any additional neuropsychiatric findings are very rare. However, special attention must be paid to those presenting with atypical mental illnesses with additional neurological symptoms, evidence of clinically-significant cognitive involvement, profound sleep-wake perturbations, seizures, electroencephalographic, or magnetic resonance imaging pathologies to be able to identify cases with autoimmune-mediated psychiatric syndromes.
Burkitt lymphoma (BL) is the most common B-cell lymphoma in children. Within the International Cancer Genome Consortium (ICGC), we performed whole genome and transcriptome sequencing of 39 sporadic BL. Here, we unravel interaction of structural, mutational, and transcriptional changes, which contribute to MYC oncogene dysregulation together with the pathognomonic IG-MYC translocation. Moreover, by mapping IGH translocation breakpoints, we provide evidence that the precursor of at least a subset of BL is a B-cell poised to express IGHA. We describe the landscape of mutations, structural variants, and mutational processes, and identified a series of driver genes in the pathogenesis of BL, which can be targeted by various mechanisms, including IG-non MYC translocations, germline and somatic mutations, fusion transcripts, and alternative splicing.
The study of the azimuthal anisotropy of inclusive muons produced in p–Pb collisions at √sNN=8.16 TeV, using the ALICE detector at the LHC is reported. The measurement of the second-order Fourier coefficient of the particle azimuthal distribution, v2, is performed as a function of transverse momentum pT in the 0–20% high-multiplicity interval at both forward (2.03<yCMS<3.53) and backward (−4.46<yCMS<−2.96) rapidities over a wide pT range, 0.5<pT<10 GeV/c, in which a dominant contribution of muons from heavy-flavour hadron decays is expected at pT>2 GeV/c. The v2 coefficient of inclusive muons is extracted using two different techniques, namely two-particle cumulants, used for the first time for heavy-flavour measurements, and forward–central two-particle correlations. Both techniques give compatible results. A positive v2 is measured at both forward and backward rapidities with a significance larger than 4.7σ and 7.6σ, respectively, in the interval 2<pT<6 GeV/c. Comparisons with previous measurements in p–Pb collisions at √sNN=5.02 TeV, and with AMPT and CGC-based theoretical calculations are discussed. The findings impose new constraints on the theoretical interpretations of the origin of the collective behaviour in small collision systems.
Measurements of the elliptic flow coefficient relative to the collision plane defined by the spectator neutrons v2{ΨSP} in collisions of Pb ions at center-of-mass energy per nucleon–nucleon pair sNN=2.76 TeV and Xe ions at sNN=5.44 TeV are reported. The results are presented for charged particles produced at midrapidity as a function of centrality and transverse momentum for the 5–70% and 0.2–6 GeV/c ranges, respectively. The ratio between v2{ΨSP} and the elliptic flow coefficient relative to the participant plane v2{4}, estimated using four-particle correlations, deviates by up to 20% from unity depending on centrality. This observation differs strongly from the magnitude of the corresponding eccentricity ratios predicted by the TRENTo and the elliptic power models of initial state fluctuations that are tuned to describe the participant plane anisotropies. The differences can be interpreted as a decorrelation of the neutron spectator plane and the reaction plane because of fragmentation of the remnants from the colliding nuclei, which points to an incompleteness of current models describing the initial state fluctuations. A significant transverse momentum dependence of the ratio v2{ΨSP}/v2{4} is observed in all but the most central collisions, which may help to understand whether momentum anisotropies at low and intermediate transverse momentum have a common origin in initial state fluctuations. The ratios of v2{ΨSP} and v2{4} to the corresponding initial state eccentricities for Xe–Xe and Pb–Pb collisions at similar initial entropy density show a difference of (7.0±0.9)% with an additional variation of +1.8% when including RHIC data in the TRENTo parameter extraction. These observations provide new experimental constraints for viscous effects in the hydrodynamic modeling of the expanding quark–gluon plasma produced in heavy-ion collisions at the LHC.