Refine
Year of publication
Document Type
- Preprint (707)
- Article (418)
- Part of a Book (2)
Has Fulltext
- yes (1127)
Is part of the Bibliography
- no (1127)
Keywords
- Heavy Ion Experiments (21)
- Hadron-Hadron Scattering (14)
- Hadron-Hadron scattering (experiments) (11)
- LHC (10)
- Heavy-ion collision (6)
- Jets (6)
- ALICE experiment (4)
- Collective Flow (4)
- Heavy Ions (4)
- Heavy Quark Production (4)
Institute
- Physik (1114)
- Frankfurt Institute for Advanced Studies (FIAS) (1044)
- Informatik (1010)
- Medizin (7)
- Gesellschaftswissenschaften (4)
- Informatik und Mathematik (3)
- Hochschulrechenzentrum (2)
- Institut für Ökologie, Evolution und Diversität (1)
- Kulturwissenschaften (1)
- Pharmazie (1)
In this paper we propose a sociological concept of innovation capable of transcending the limitations faced by the approaches of common theories of action. The concept was formulated by Ulrich Oevermann and is based upon Max Weber’s theory of charismatic authority. We apply this concept to archaeological data, using the example of Neolithic copper metallurgy in central Europe, and discuss the importance of analyzing innovations that failed to materialize even though they might have been "in the air" at the time. The concept sketched here enables the scientific study of such a phenomenon.
Accumulating evidence suggests that iron homeostasis is disturbed in tumors. We aimed at clarifying the distribution of iron in renal cell carcinoma (RCC). Considering the pivotal role of macrophages for iron homeostasis and their association with poor clinical outcome, we investigated the role of macrophage-secreted iron for tumor progression by applying a novel chelation approach. We applied flow cytometry and multiplex-immunohistochemistry to detect iron-dependent markers and analyzed iron distribution with atomic absorption spectrometry in patients diagnosed with RCC. We further analyzed the functional significance of iron by applying a novel extracellular chelator using RCC cell lines as well as patient-derived primary cells. The expression of iron-regulated genes was significantly elevated in tumors compared to adjacent healthy tissue. Iron retention was detected in tumor cells, whereas tumor-associated macrophages showed an iron-release phenotype accompanied by enhanced expression of ferroportin. We found increased iron amounts in extracellular fluids, which in turn stimulated tumor cell proliferation and migration. In vitro, macrophage-derived iron showed pro-tumor functions, whereas application of an extracellular chelator blocked these effects. Our study provides new insights in iron distribution and iron-handling in RCC. Chelators that specifically scavenge iron in the extracellular space confirmed the importance of macrophage-secreted iron in promoting tumor growth
Background: Although anterior cruciate ligament (ACL) tear-prevention programs may be effective in the (secondary) prevention of a subsequent ACL injury, little is known, yet, on their effectiveness and feasibility. This study assesses the effects and implementation capacity of a secondary preventive motor-control training (the Stop-X program) after ACL reconstruction.
Methods and design: A multicenter, single-blind, randomized controlled, prospective, superiority, two-arm design is adopted. Subsequent patients (18–35 years) with primary arthroscopic unilateral ACL reconstruction with autologous hamstring graft are enrolled. Postoperative guideline rehabilitation plus Classic follow-up treatment and guideline rehabilitation plus the Stop-X intervention will be compared. The onset of the Stop-X program as part of the postoperative follow-up treatment is individualized and function based. The participants must be released for the training components. The endpoint is the unrestricted return to sport (RTS) decision. Before (where applicable) reconstruction and after the clearance for the intervention (aimed at 4–8 months post surgery) until the unrestricted RTS decision (but at least until 12 months post surgery), all outcomes will be assessed once a month. Each participant is consequently measured at least five times to a maximum of 12 times. Twelve, 18 and 24 months after the surgery, follow-up-measurements and recurrence monitoring will follow. The primary outcome assessement (normalized knee-separation distance at the Drop Jump Screening Test (DJST)) is followed by the functional secondary outcomes assessements. The latter consist of quality assessments during simple (combined) balance side, balance front and single-leg hops for distance. All hop/jump tests are self-administered and filmed from the frontal view (3-m distance). All videos are transferred using safe big content transfer and subsequently (and blinded) expertly video-rated. Secondary outcomes are questionnaires on patient-reported knee function, kinesiophobia, RTS after ACL injury and training/therapy volume (frequency – intensity – type and time). All questionnaires are completed online using the participants’ pseudonym only.
Group allocation is executed randomly. The training intervention (Stop-X arm) consists of self-administered home-based exercises. The exercises are step-wise graduated and follow wound healing and functional restoration criteria. The training frequency for both arms is scheduled to be three times per week, each time for a 30 min duration. The program follows current (secondary) prevention guidelines.
Repeated measurements gain-score analyses using analyses of (co-)variance are performed for all outcomes.
Trial registration: German Clinical Trials Register, identification number DRKS00015313. Registered on 1 October 2018.
Macrophages supply iron to the breast tumor microenvironment by enforced secretion of lipocalin-2 (Lcn-2)-bound iron as well as the increased expression of the iron exporter ferroportin (FPN). We aimed at identifying the contribution of each pathway in supplying iron for the growing tumor, thereby fostering tumor progression. Analyzing the expression profiles of Lcn-2 and FPN using the spontaneous polyoma-middle-T oncogene (PyMT) breast cancer model as well as mining publicly available TCGA (The Cancer Genome Atlas) and GEO Series(GSE) datasets from the Gene Expression Omnibus database (GEO), we found no association between tumor parameters and Lcn-2 or FPN. However, stromal/macrophage-expression of Lcn-2 correlated with tumor onset, lung metastases, and recurrence, whereas FPN did not. While the total iron amount in wildtype and Lcn-2−/− PyMT tumors showed no difference, we observed that tumor-associated macrophages from Lcn-2−/− compared to wildtype tumors stored more iron. In contrast, Lcn-2−/− tumor cells accumulated less iron than their wildtype counterparts, translating into a low migratory and proliferative capacity of Lcn-2−/− tumor cells in a 3D tumor spheroid model in vitro. Our data suggest a pivotal role of Lcn-2 in tumor iron-management, affecting tumor growth. This study underscores the role of iron for tumor progression and the need for a better understanding of iron-targeted therapy approaches.
While the importance of the iron-load of lipocalin-2 (Lcn-2) in promoting tumor progression is widely appreciated, underlying molecular mechanisms largely remain elusive. Considering its role as an iron-transporter, we aimed at clarifying iron-loaded, holo-Lcn-2 (hLcn-2)-dependent signaling pathways in affecting renal cancer cell viability. Applying RNA sequencing analysis in renal CAKI1 tumor cells to explore highly upregulated molecular signatures in response to hLcn-2, we identified a cluster of genes (SLC7A11, GCLM, GLS), which are implicated in regulating ferroptosis. Indeed, hLcn-2-stimulated cells are protected from erastin-induced ferroptosis. We also noticed a rapid increase in reactive oxygen species (ROS) with subsequent activation of the antioxidant Nrf2 pathway. However, knocking down Nrf2 by siRNA was not sufficient to induce erastin-dependent ferroptotic cell death in hLcn-2-stimulated tumor cells. In contrast, preventing oxidative stress through N-acetyl-l-cysteine (NAC) supplementation was still able to induce erastin-dependent ferroptotic cell death in hLcn-2-stimulated tumor cells. Besides an oxidative stress response, we noticed activation of the integrated stress response (ISR), shown by enhanced phosphorylation of eIF-2α and induction of ATF4 after hLcn-2 addition. ATF4 knockdown as well as inhibition of the ISR sensitized hLcn-2-treated renal tumor cells to ferroptosis, thus linking the ISR to pro-tumor characteristics of hLcn-2. Our study provides mechanistic details to better understand tumor pro-survival pathways initiated by iron-loaded Lcn-2.
In seinem unlängst erschienenen Buch „Citizen Science“ untersucht der Wissenschaftstheoretiker Peter Finke die Rolle von Laiinnen und Laien für die Wissenschaft. Sein Anliegen ist es, ihre Bedeutung für den Erkenntnisfortschritt wie auch für ein praxisbezogenes bürgerschaftliches Engagement darzulegen. Aus zahlreichen Blickwinkeln variiert Finke den Grundgedanken einer Kontinuität des Handelns von Laiinnen und Laien zu dem von Fachwissenschaftlerinnen und Fachwissenschaftlern, die durch die institutionalisierten Erscheinungsformen der Wissenschaft verschleiert wird. Demgegenüber sollen im vorliegenden Beitrag Aspekte der Diskontinuität hervorgehoben werden, die es zu berücksichtigen gilt, gerade wenn man von der Wichtigkeit einer Etablierung und Förderung von „Citizen Science“ überzeugt ist.
Die Frage, ob und in welcher Hinsicht ADORNO als Vorbereiter eines Paradigmas qualitativer Sozialforschung verstanden werden kann, wird diskutiert anhand zweier Briefe ADORNOs an Paul LAZARSFELD aus dem Jahre 1938, als er in dessen "Radio Research Project" an der Universität Princeton mitzuarbeiten begann. ADORNO musste sich hier erstmals mit empirischer Sozialforschung amerikanischer Prägung ins Verhältnis setzen, wobei er in Ermangelung praktischer Erfahrung auf diesem Gebiet zunächst ganz auf seine Bordmittel als Philosoph und Künstler angewiesen war. In der Korrespondenz mit LAZARSFELD artikulierten sich erstmals Überlegungen, die in ADORNOs Schriften zur Sozialforschung aus der Nachkriegszeit ihre kanonische Gestalt fanden. Die quantifizierenden Verfahren kritisierend, entwickelte er gleichsam naturwüchsig ein Modell qualitativer Forschung, das aber zugleich bestimmten, auch später nicht überwundenen Restriktionen unterlag, die ihren Grund vor allem in Vorbehalten gegenüber methodisch geregelten Vorgehen überhaupt hatten.
My contribution focuses on the relationship between theory and praxis, since the task of a “critical archaeology” is to mediate between these two spheres. Its target audience is the public, not other scholars. Critical archaeology is not part of scientific practice, but rather is part of intellectual reasoning that is both value-laden and that exercises practical critique. Respect for the specific logics of theory and praxis is crucial for its success. A “critical archaeology” that merits its name must steer its way between the Scylla of a technocratic paternalism that limits praxis and the Charybdis of submission to theory under the presumption of the “relevance of praxis.”
Das Anliegen des Beitrages ist es, auf wissenschaftliche Metanarrative als vernachlässigten Faktor bei der Interpretation archäologischer Funde und Befunde im Allgemeinen und bronzezeitlicher im Besonderen hinzuweisen. Diese Narrative zeichnen kohärente Bilder von Epochen, in welche neue Evidenzen eingepasst werden, denen so kaum die Möglichkeit eingeräumt wird, die voreingerichteten, in sich plausiblen und suggestiven Deutungsmuster und Deutungsroutinen in Frage zu stellen. Kontrastierend diskutiert werden die dominanten Metanarrative bezüglich des Neolithikums und der Bronzezeit: Während Ersteres das einer friedlicher Zyklizität beschreibt, ist Letzteres eines der Agonalität und des Fortschritts, dessen Wirkmächtigkeit und Hermetik anhand zweier populärwissenschaftlicher Darstellungen beispielhaft aufgezeigt wird.
The ALICE Zero Degree Calorimeter system (ZDC) is composed of two identical sets of calorimeters, placed at opposite sides with respect to the interaction point, 114 meters away from it, complemented by two small forward electromagnetic calorimeters (ZEM). Each set of detectors consists of a neutron (ZN) and a proton (ZP) ZDC. They are placed at zero degrees with respect to the LHC axis and allow to detect particles emitted close to beam direction, in particular neutrons and protons emerging from hadronic heavy-ion collisions (spectator nucleons) and those emitted from electromagnetic processes. For neutrons emitted by these two processes, the ZN calorimeters have nearly 100% acceptance.
During the √sNN = 2.76 TeV Pb-Pb data-taking, the ALICE Collaboration studied forward neutron emission with a dedicated trigger, requiring a minimum energy deposition in at least one of the two ZN. By exploiting also the information of the two ZEM calorimeters it has been possible to separate the contributions of electromagnetic and hadronic processes and to study single neutron vs. multiple neutron emission.
The measured cross sections of single and mutual electromagnetic dissociation of Pb nuclei at √sNN = 2.76 TeV, with neutron emission, are σsingle EMD = 187:4 ± 0.2 (stat.)−11.2+13.2 (syst.) b and σmutual EMD = 5.7 ± 0.1 (stat.) ±0.4 (syst.) b, respectively [1]. This is the first measurement of electromagnetic dissociation of 208Pb nuclei at the LHC energies, allowing a test of electromagnetic dissociation theory in a new energy regime. The experimental results are compared to the predictions from a relativistic electromagnetic dissociation model.