Vector fuzzy dark matter, fifth forces, and binary pulsars

We study the secular effects that an oscillating background ultralight (fuzzy) cosmological vector field has on the dynamics of binary systems; such effects appear when the field and the binary are in resonance. We first consider the gravitational interaction between the field and the systems, and quantify the main differences with an oscillating background scalar field. If the energy density of such a field is sufficiently large, as required if it is supposed to be all of the dark matter, we show that the secular effects could yield potentially observable signatures in high precision time of arrival measurements of binary pulsars. We then analyse the secular effects that arise when the field is directly coupled to the bodies in the binary. We show that this study is particularly relevant for models where fuzzy dark matter mediates a baryonic force B (or B-L, with L the lepton number), due to the stellar amount of nucleons present in the stars. The constraints we obtain from current data are already competitive with (or even more constraining than) laboratory tests of the equivalence principle.Fil: Lopez Nacir, Diana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Urban, Federico R.. Czech Academy of Sciences; República Chec

An unexpected journey?

Professionelle Lehrkompetenz wird nicht einmalig erworben, son-­ dern kontinuierlich (weiter-­)entwickelt. Diese Entwicklung ist ein Lernprozess, der selbstgesteuert oder weiterbildungsgestützt sowie bewusst oder unbewusst erfolgen kann. Der Reflexion des persönlichen Lernprozesses, der Einfluss dessen auf das eigene Lehrverständnis und -handeln kommt somit eine besondere Rolle bei der eigenen Kompetenzentwicklung zu. Die Portfolioarbeit kann dabei als ein Verfahren genutzt werden, um diese Reflexion methodisch zu gestalten

Bayesian sensitivity of binary pulsars to ultra-light dark matter

Ultra-light dark matter perturbs the orbital motion of binary pulsars, in particular by causing peculiar time variations of a binary's orbital parameters, which then induce variations in the pulses' times-of-arrival. Binary pulsars have therefore been shown to be promising detectors of ultra-light dark matter. To date, the sensitivity of binary pulsars to ultra-light dark matter has only been studied for dark matter masses in a narrow resonance band around a multiple of the binary pulsar orbital frequency. In this study we devise a two-step, bayesian method that enables us to compute semi-analytically the sensitivity for all masses, also away from the resonance, and to combine several observed binaries into one global sensitivity curve. We then apply our method to the case of a universal, linearly-coupled, scalar ultra-light dark matter. We find that with next-generation radio observatories the sensitivity to the ultra-light dark matter coupling will surpass that of solar-system constraints for a decade in mass around $m\sim10^{-21}$ $\text{eV}$, even beyond resonance.Comment: 40 pages,15 figure

Strategien der Professionalisierung in der Hochschuldidaktik

Der Beitrag nimmt die im Third-Space tätigen Personen im Arbeitsfeld der Hochschuldidaktik, ihre Entwicklungswege und Professionalisierungsstrategien in den Blick. Im Fokus stehen die bisherigen Tätigkeiten und Rollen der Third-Space Mitarbeiter sowie neue Tendenzen und damit einhergehende Herausforderungen. Vorhandene deutschsprachige und internationale theoretische Beiträge sowie empirische Studien werden gesichtet, zusammengeführt und diskutiert. Ziel ist es, den Ist-Zustand der hochschuldidaktischen Professionalisierungsforschung darzustellen, um Hinweise auf mögliche Spezifika professioneller hochschuldidaktischer Tätigkeiten zu gewinnen und offene Fragen herauszuarbeiten. 15.12.2010 | Diana Urban & Dorothee M. Meister (Paderborn

Jetzt aber PaSDa! Herausforderungen und Konzepte der Hochschuldidaktik Paderborn zur Frage: Wie kommt das Neue in die Hochschule?

Der Beitrag nimmt ausgehend von aktuellen Diskursen und Praxiserfahrungen neue Gestaltungskonzepte der hochschuldidaktischen Einrichtung an der Universität Paderborn in den Blick. Im Fokus stehen die steigende Nachfrage an Methodensammlungen und Rezeptwissen seitens der Teilnehmer/innen hochschuldidaktischer Angebote sowie die Entwicklung der professionellen Lehrkompetenz als Kernelement des Curriculums hochschuldidaktischer Aus- und Weiterbildung. In Form einer kurzen Analyse der Ausgangslage werden vorhandene Probleme dargestellt und es wird dazu Stellung bezogen. Dabei werden Faktoren identifiziert, die eine nachhaltige Implementierung des Neuen in der Hochschullehre beeinflussen. Diese dienen weiterführend als Anhaltspunkt für die Entwicklung der Modellvorhaben – das PaSDa-Buffet und das Lernportfolio. 02.11.2011 | Diana Urban & Daniel Al-Kabbani (Paderborn

Učinak odabranih makrolida na neka obilježja goveđih leukocita

The aim of the study was to evaluate the effect of tylosin, tilmicosin and roxithromycin on viability, nitro blue tetrazolium reduction (NBT) assay, chemotaxis, apoptosis and oxidative stress in bovine leukocytes in vitro conditions. The material for the study consisted of blood collected into EDTA tubes from the external jugular vein of Holstein-Friesian cattle aged 1 week to 2.5 years, during routine veterinary examinations. In leukocytes the percent of viability, nitrate ion concentration (NO), metabolic activity (NBT, nitrotetrazolium blue reduction assay), chemotactic activity and apoptosis were determined. The results indicated a slight negative effect of these macrolides on the viability of the leukocytes, and confirmed the ability of macrolides to induce apoptosis in leukocytes in vitro. These results indicate that all of the macrolides investigated exhibit a modulatory effect on the functions of leukocytes isolated from cattle of different ages. The strongest inhibitory effect on the NBT reduction assay and chemotaxis of the leukocytes was exhibited by roxithromycin, which at the same time had the least negative effect on the leukocytes.Cilj je ovog istraživanja bio procijeniti učinak tilozina, tilmikozina i roksitromicina na preživljavanje, test redukcije “nitro-tetrazol-modrog” (NBT), kemotaksiju, apoptozu i oksidacijski stres goveđih leukocita u uvjetima in vitro. Prilikom rutinskog veterinarskog pregleda, u epruvete s EDTA bila je uzeta krv iz jugularne vene goveda holštajnsko-frizijske pasmine u dobi od tjedan dana do 2,5 godine. Određen je postotak preživljavanja leukocita, koncentracija iona nitrata (NO), metabolička aktivnost (test redukcije “nitro-tetrazol-modrog”, NBT), kemotaksijska aktivnost i apoptoza. Rezultati su pokazali blagi negativni učinak spomenutih makrolida na preživljavanje leukocita i potvrdili sposobnost makrolida da potaknu njihovu apoptozu in vitro te naznačuju da svi pretraženi makrolidi imaju modulacijski učinak na funkciju leukocita goveda različite dobi. Najjači inhibicijski učinak na test redukcije NBT i kemotaksiju leukocita pokazao je roksitromicin, koji je istodobno imao najmanje negativan učinak na leukocite

Rural-Urban Policies : Changing Conceptions of the Human-Environment Relationship

Peer reviewedPostprin

The Role of the FMN-Domain of Human Cytochrome P450 Oxidoreductase in Its Promiscuous Interactions With Structurally Diverse Redox Partners

[This corrects the article DOI: 10.3389/fphar.2020.00299.].publishersversionpublishe

Editorial: Was denken Lehrende über Lehre?

Editorial 2013 | Robert Kordts-Freudinger, Daniel Al-Kabbani, Diana Urban, Tobias Zenker & Niclas Schaper (Paderborn

No effect of aspirin on mammographic density in a randomized controlled clinical trial.

BACKGROUND: Epidemiologic studies suggest a reduced risk of breast cancer among women who regularly use aspirin; a plausible mechanism is through aspirin effect on mammographic breast density, a breast cancer risk factor, possibly mediated through aspirin interference with estrogen synthesis. METHODS: In a 2-arm randomized placebo-controlled clinical trial, we evaluated the effects of 6-month administration of 325 mg/day aspirin on total mammographic breast dense area and percent of the mammographic breast image occupied by dense areas (% density) in 143 postmenopausal women. Eligible women, recruited from 2005 to 2007, were healthy, not taking hormone therapy, with elevated mammographic breast density (American College of Radiology Breast Imaging Reporting and Data System density category 2, 3, or 4) within 6 months before enrollment. RESULTS: Women were a mean (SD) 59.5 (5.5) years. Geometric mean baseline percent density was 17.6% (95% confidence interval, 14.8-20.9) in women randomized to aspirin and 19.2% (95% confidence interval, 16.3-22.7) in women randomized to placebo. Percent density decreased in women randomized to aspirin by an absolute 0.8% versus an absolute decrease of 1.2% in controls (P = 0.84). Total breast area and dense area decreased to a similar degree in women assigned to aspirin and in those assigned to placebo, with no statistically significant differences between trial arms. CONCLUSIONS: A single daily administration of adult-dose aspirin for 6 months had no effect on mammographic density in postmenopausal women. If aspirin affects breast cancer risk in postmenopausal women, it may do so through alternative pathways than mammographic breast density. (Cancer Epidemiol Biomarkers Prev 2009;18(5):1524-30)