217 research outputs found
Untersuchung zum Vorkommen von Eisenaufnahmesystemen als unspezifische Pathogenitätsfaktoren in Shiga Toxin-produzierenden Escherichia coli
Über die Verbreitung von Eisenaufnahmesystemen wie der ”High-Pathogenicity Island” (HPI) und des iroA-Genclusters in Shiga Toxin-produzierenden Escherichia coli ist wenig bekannt. 147 klinische STEC-Isolate wurden auf ihre Ausstattung mit Shiga Toxin-Genen (stx), Intimin-kodierenden Genen (eae), Markergene der HPI (irp2, fyuA) und iroN als Teil des iroA-Genclusters untersucht. In einem weiteren Schritt wurde der strukturelle Aufbau der detektierten HPI anhand eines repräsentativen E. coli O26 Stamms analysiert. Irp2/fyuA wurden konstant in O26: H-/H11 Stämmen nachgewiesen, was auf ein defektes Integrase-Gen zurückgeführt werden könnte. iroN fand sich in drei Stämmen des Serotyps O111:H-. Das häufig in extra-intestinalen E. coli (ExPEC) vorkommende iroA-Gencluster ist in STEC sehr selten; allerdings hat in wenigen Stämmen ein Genaustausch zwischen ExPEC und STEC stattgefunden
Suppression of ferromagnetism in CeSi_1.81 under temperature and pressure
We have studied the pressure dependence of the magnetization of single
crystalline CeSi_1.81. At ambient pressure ferromagnetism develops below T_C =
9.5 Below ~ 5 K an additional shoulder in low-field hysteresis loops and a
metamagnetic crossover around 4 T suggest the appearance of an additional
magnetic modulation to the ferromagnetic state. The suppression of the magnetic
order in CeSi_1.81 as function of temperature at ambient pressure and as
function of pressure at low temperature are in remarkable qualitative
agreement. The continuous suppression of the ordered moment at p ~ 13.1 kbar
suggests the existence of a ferromagnetic quantum critical point in this
material.Comment: 9 pages, 9 figures, to be published in Physical Review
Entwicklung, Erprobung, Umsetzung und Evaluation von Strategien in den Bereichen Tiergesundheit, Haltung, Fütterung, Management in der ökologischen Ferkelerzeugung
Die ökologische Ferkelerzeugung weist hinsichtlich Tiergesundheit, Leistungsfähigkeit und Wirtschaftlichkeit große Defizite auf. Die Ursachen sind komplex und betreffen u.a. Fütterung, Haltung und Hygiene. Für diese Bereiche sollten durch Exakt- und Praxisversuche Lösungsansätze entwickelt werden. Teilprojekte umfassten folgende Themen: Der Einfluss unterschiedlicher Raufutter in der Fütterung tragender Sauen, die Wirkung einer Inulinzugabe sowie vom Extrudieren von Ackerbohnen in Sauen- und Ferkelfutter, die Bewertung alternativer Desinfektionsverfahren, ein Vergleich von Einzelhaltung versus kombinierte Einzel- und Gruppenhaltung säugender Sauen sowie die Optimierung des Ferkelliegebereichs in der Ferkelaufzucht.
Zentrale Ergebnisse:
- Die verschiedenen Raufuttervarianten (Kleegrassilage, Heu, Maissilage, Topinamburknollen) hatten keine negativen Effekte auf Körperkonstitution und Reproduktionsleistungen der Sauen.
- Die Saugferkel der mit Inulin versorgten Sauen entwickelten sich gegenüber der Kontrollgruppe während der Säugezeit leistungsmäßig besser, während der Ferkelaufzucht gab es keine Leistungssteigerungen. Der Einsatz von getoasteten Ackerbohnen führte zu signifikant besseren Ferkelzunahmen gegenüber dem Einsatz von extrudierten Ackerbohnen.
- Keines der getesteten alternativen Desinfektionsverfahren (HeiĂźwasserdampf, elektroaktiviertes Wasser, Abflammen) ist eine Alternative zur chemischen Desinfektion bezĂĽglich Keimreduktion, Arbeitsaufwand und Kosten.
- Gruppensäugen führt bei Sauen zu erhöhter Aktivität sowie zu spezifischen Verhaltensanpassungen. Leistungseinbußen konnten weder für Sauen noch für Ferkel dokumentiert werden. „Gruppensäugen“ führt zu einem höheren Arbeitszeitbedarf und steigenden Baukosten.
- Der Liegebereich für Aufzuchtferkel ist in vielen Betrieben nicht optimal und durch z. T. einfache Maßnahmen (Abdichten des Liegenestes, Wärmedämmung des Bodens, Bodenheizung, Anbringen einer weiteren Wärmequelle) für die Tiere zu verbessern
Pulmonary ORMDL3 is critical for induction of Alternaria -induced allergic airways disease
Genome-wide association studies have identified the ORM (yeast)-like protein isoform 3 (ORMDL3) gene locus on human chromosome 17q to be a highly significant risk factor for childhood-onset asthma.
Objective
We sought to investigate in vivo the functional role of ORMDL3 in disease inception.
Methods
An Ormdl3-deficient mouse was generated and the role of ORMDL3 in the generation of allergic airways disease to the fungal aeroallergen Alternaria alternata was determined. An adeno-associated viral vector was also used to reconstitute ORMDL3 expression in airway epithelial cells of Ormdl3 knockout mice.
Results
Ormdl3 knockout mice were found to be protected from developing allergic airways disease and showed a marked decrease in pathophysiology, including lung function and airway eosinophilia induced by Alternaria. Alternaria is a potent inducer of cellular stress and the unfolded protein response, and ORMDL3 was found to play a critical role in driving the activating transcription factor 6–mediated arm of this response through Xbp1 and downstream activation of the endoplasmic reticulum–associated degradation pathway. In addition, ORMDL3 mediated uric acid release, another marker of cellular stress. In the knockout mice, reconstitution of Ormdl3 transcript levels specifically in the bronchial epithelium resulted in reinstatement of susceptibility to fungal allergen–induced allergic airways disease.
Conclusions
This study demonstrates that ORMDL3, an asthma susceptibility gene identified by genome-wide association studies, contributes to key pathways that promote changes in airway physiology during allergic immune responses
FashionBrain Project: A Vision for Understanding Europe's Fashion Data Universe
A core business in the fashion industry is the understanding and
prediction of customer needs and trends. Search engines and social
networks are at the same time a fundamental bridge and a costly
middleman between the customer’s purchase intention and the
retailer. To better exploit Europe’s distinctive characteristics e.g.,
multiple languages, fashion and cultural differences, it is pivotal to
reduce retailers’ dependence to search engines. This goal can be
achieved by harnessing various data channels (manufacturers and
distribution networks, online shops, large retailers, social media,
market observers, call centers, press/magazines etc.) that retailers
can leverage in order to gain more insight about potential buyers,
and on the industry trends as a whole. This can enable the creation
of novel on-line shopping experiences, the detection of influencers,
and the prediction of upcoming fashion trends.
In this paper, we provide an overview of the main research
challenges and an analysis of the most promising technological
solutions that we are investigating in the FashionBrain project
Platinum Group Metal-Doped Tungsten Phosphates for Selective C-H Activation of Lower Alkanes
Platinum group metal (PGM)-based catalysts are known to be highly active in the total combustion of lower hydrocarbons. However, through an alternative catalyst design reported in this paper by isolating PGM-based active sites in a tungsten phosphate matrix, we present a class of catalysts for selective oxidation of n-butane, propane, and propylene that do not contain Mo or V as redox-active elements. Two different catalyst concepts have been pursued. Concept A: isolating Ru-based active sites in a tungsten phosphate matrix coming upon as ReO3-type structure. Concept B: dilution of PGM-based active sites through the synthesis of X-ray amorphous Ru tungsten phosphates supported on SiO2. Using a high-throughput screening approach, model catalysts over a wide compositional range were evaluated for C3 and C4 partial oxidation. Bulk crystalline and supported XRD amorphous phases with similar Ru/W/P compositions showed comparable performance. Hence, for these materials, composition is more crucial than the degree of crystallinity. Further studies for optimization on second-generation supported systems revealed even better results. High selectivity for n-butane oxidation to maleic anhydride and propane oxidation to an acrolein/acrylic acid has been achieved
Electronic structure and nesting-driven enhancement of the RKKY interaction at the magnetic ordering propagation vector in Gd2PdSi3 and Tb2PdSi3
We present first-time measurements of the Fermi surface and low-energy
electronic structure of intermetallic compounds Gd2PdSi3 and Tb2PdSi3 by means
of angle-resolved photoelectron spectroscopy (ARPES). Both materials possess a
flower-like Fermi surface consisting of an electron barrel at the G point
surrounded by spindle-shaped electron pockets originating from the same band.
The band bottom of both features lies at 0.5 eV below the Fermi level. From the
experimentally measured band structure, we estimate the momentum-dependent RKKY
coupling strength and demonstrate that it is peaked at the 1/2 GK wave vector.
Comparison with neutron diffraction data from the same crystals shows perfect
agreement of this vector with the propagation vector of the low-temperature
in-plane magnetic order, thereby demonstrating the decisive role of the Fermi
surface geometry in explaining the complex magnetically ordered ground state of
ternary rare earth silicides.Comment: 4 pages, 4 figure
Field-induced delocalization and Zener breakdown in semiconductor superlattices
We investigate the energy spectrum and the electron dynamics of a band in a semiconductor superlattice as a function of the electric field. Linear optical spectroscopy shows that, for high fields, the well-known localization of the Bloch states is followed by a field-induced delocalization, associated with Zener breakdown. Using time-resolved measurements, we observe Bloch oscillations in a regime where they are damped by Zener breakdown
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