71 research outputs found
The Equal Access Study. Research Concept and Study Design
The volume at hand consists of the study’s research framework and design. It also contains the summaries of the three country reports written by different national experts. To make the information accessible for national and international readers, the conceptual paper as well as the three summaries are published in German and English. (DIPF/Orig.
Rezension: Anna Maria Ifland (2017): Kindheitspolitik in Deutschland und Norwegen - Konstruktionen von Kindheit und Betreuung im Vergleich
InjektionsdĂĽngung
Auf drei sächsischen Versuchsstandorten (D, Lö, V) wurde über zwei Jahre die Wirkung der Injektionsdüngung auf Ertrag und Qualität von Winterweizen, Wintergerste und Winterraps untersucht. Nach der Injektion ammoniumhaltiger Düngerlösung in den Boden ist der Stickstoff für die Pflanzen bei Trockenheit besser verfügbar. Das Risiko von Nitratauswaschungen wird vermindert und die Nährstoffe sind weniger erosionsgefährdet.
Die Ergebnisse zeigen, dass eine alleinige N-Injektion sowohl zu Winterweizen und Wintergerste als auch zu Winterraps ohne Ertragseinbußen im Vergleich zur praxisüblichen, geteilten Düngung mit Kalkammonsalpeter möglich ist. Zu Ertragsvorteilen führte die Injektionsdüngung besonders nach der ausgeprägten Frühsommertrockenheit 2009 auf dem leichten D-Standort.
Landwirte, die auf ihren Flächen die N-Injektion anwenden, bestätigen lt. einer Umfrage gleich hohe bzw. höhere Erträge, gesündere Bestände und einen geringeren Pflanzenschutzmitteleinsatz.
Für die Landwirtschaftsbetriebe in Sachsen stellt die Injektionsdüngung eine Möglichkeit dar, die Auswirkungen von Frühsommertrockenheit zu minimieren und die Ertragsstabilität zu verbessern
Die Equal Access Study. Konzeptioneller Rahmen und Forschungsdesign
Das vorliegende Papier erläutert den konzeptionellen Rahmen und das Design der Equal Access Study. Weiterhin enthält es Zusammenfassungen der drei Länderberichte, die von WissenschaftlerInnen aus dem jeweiligen Land verfasst wurden. Um einer internationalen Leserschaft den Zugang zu den vorliegenden Informationen zu ermöglichen, werden das Rahmenpapier sowie die Zusammenfassungen auch auf Englisch veröffentlicht. (DIPF/Orig.
Sexual selection and the evolution of male pheromone glands in philanthine wasps (Hymenoptera, Crabronidae)
Background: Sexual selection is thought to promote evolutionary changes and diversification. However, the impact of sexual selection in relation to other selective forces is difficult to evaluate. Male digger wasps of the tribe Philanthini (Hymenoptera, Philanthinae) scent mark territories to attract receptive females. Consequently, the organs for production and storage of the marking secretion, the mandibular gland (MG) and the postpharyngeal gland (PPG), are subject to sexual selection. In female Philanthini, these glands are most likely solely subject to natural selection and show very little morphological diversity. According to the hypothesis that sexual selection drives interspecific diversity, we predicted that the MG and PPG show higher interspecific variation in males than in females. Using histological methods, 3D-reconstructions, and multivariate statistical analysis of morphological characters, we conducted a comparative analysis of the MG and the PPG in males of 30 species of Philanthini and three species of the Cercerini and Aphilanthopsini, two related tribes within the Philanthinae. Results: We found substantial interspecific diversity in gland morphology with regard to gland incidence, size, shape and the type of associated secretory cells. Overall there was a phylogenetic trend: Ensuing from the large MGs and small PPGs of male Cercerini and Aphilanthopsini, the size and complexity of the MG was reduced in male Philanthini, while their PPG became considerably enlarged, substantially more complex, and associated with an apparently novel type of secretory cells. In some clades of the Philanthini the MG was even lost and entirely replaced by the PPG. However, several species showed reversals of and exceptions from this trend. Head gland morphology was significantly more diverse among male than among female Philanthinae. Conclusion: Our results show considerable variation in male head glands including the loss of an entire gland system and the evolution of a novel kind of secretory cells, confirming the prediction that interspecific diversity in head gland morphology is higher in male than in female Philanthini. We discuss possible causes for the remarkable evolutionary changes in males and we conclude that this high diversity has been caused by sexual selection
Verbesserung der P-Effizienz im Pflanzenbau
In Gefäß- und Feldversuchen wurde die Wirkung der Unterfußdüngung und der Injektionsdüngung von Phosphor auf den Ertrag und die P-Aufnahme verschiedener Kulturarten untersucht. Ebenfalls untersucht wurde die P-Düngewirkung von Schlacke aus der Hochtemperatur-Schmelzbehandlung von Klärschlamm nach dem Mephrec®-Verfahren.
Die Ergebnisse zeigen, dass bei niedrigen pflanzenverfügbaren P-Gehalten (Versorgungsstufe A, B) eine entzugsorientierte Düngung nicht ausreicht, um optimale Erträge zu erreichen. Unterfußdüngung und P-Injektion steigern die P-Effizienz und dienen dem Gewässerschutz. Die Schlacke sollte gemahlen eingesetzt werden, weil sich granulierte Varianten als wenig wirksam erwiesen
Climacteric Lowers Plasma Levels of Platelet-Derived Microparticles: A Pilot Study in Pre-versus Postmenopausal Women
Background: Climacteric increases the risk of thrombotic events by alteration of plasmatic coagulation. Up to now, less is known about changes in platelet-(PMP) and endothelial cell-derived microparticles (EMP). Methods: In this prospective study, plasma levels of microparticles (MP) were compared in 21 premenopausal and 19 postmenopausal women. Results: No altered numbers of total MP or EMP were measured within the study groups. However, the plasma values of CD61-exposing MP from platelets/megakaryocytes were higher in premenopausal women (5,364 x 10(6)/l, range 4,384-17,167) as compared to postmenopausal women (3,808 x 10(6)/l, range 2,009-8,850; p = 0.020). This differentiation was also significant for the subgroup of premenopausal women without hormonal contraceptives (5,364 x 10(6)/l, range 4,223-15,916; p = 0.047; n = 15). Furthermore, in premenopausal women, higher plasma levels of PMP exposing CD62P were also present as compared to postmenopausal women (288 x 10(6)/l, range 139-462, vs. 121 x 10(6)/l, range 74-284; p = 0.024). This difference was also true for CD63+ PMP levels (281 x 10(6)/l, range 182-551, vs. 137 x 10(6)/l, range 64-432; p = 0.015). Conclusion: Climacteric lowers the level of PMP but has no impact on the number of EMP in women. These data suggest that PMP and EMP do not play a significant role in enhancing the risk of thrombotic events in healthy, postmenopausal women. Copyright (C) 2012 S. Karger AG, Base
Pathophysiological role of prostanoids in coagulation of the portal venous system in liver cirrhosis
BACKGROUND: Prostanoids are important regulators of platelet aggregation and thrombotic arterial diseases. Their involvement in the development of portal vein thrombosis, frequent in decompensated liver cirrhosis, is still not investigated. METHODS: Therefore, we used pro-thrombotic venous milieu generation by bare metal stent transjugular intrahepatic portosystemic shunt insertion, to study the role of prostanoids in decompensated liver cirrhosis. Here, 89 patients receiving transjugular intrahepatic portosystemic shunt insertion were included in the study, and baseline levels of thromboxane B2, prostaglandin D2 and prostaglandin E2 were measured in the portal and the hepatic vein. RESULTS: While the hepatic vein contained higher levels of thromboxane B2 than the portal vein, levels of prostaglandin E2 and D2 were higher in the portal vein (all P<0.0001). Baseline concentrations of thromboxane B2 in the portal vein were independently associated with an increase of portal hepatic venous pressure gradient during short term follow-up, as an indirect sign of thrombogenic potential (multivariable P = 0.004). Moreover, severity of liver disease was inversely correlated with portal as well as hepatic vein levels of prostaglandin D2 and E2 (all P<0.0001). CONCLUSIONS: Elevated portal venous thromboxane B2 concentrations are possibly associated with the extent of thrombogenic potential in patients with decompensated liver cirrhosis. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03584204
Novel sol-gel prepared zinc fluoride: synthesis, characterisation and acid-base sites analysis
The fluorolytic sol-gel route sets a milestone in the development of synthesis methods for nanoscopic fluoride materials. They exhibit fundamentally distinct properties in comparison to classically prepared metal fluorides. To broaden this area, we report in this paper the first fluorolytic sol-gel synthesis of ZnFâ‚‚. The obtained sol was studied with dynamic light scattering (DLS). The dried ZnFâ‚‚ xerogel was investigated with elemental analysis, thermal analysis, powder X-ray diffraction (XRD), solid-state MAS NMR, and Nâ‚‚ adsorption-desorption measurements. The characterisations revealed a remarkably high surface area of the sol-gel prepared ZnFâ‚‚. To determine key parameters deciding its prospects in future catalytic applications, we studied the surface acidity-basicity by using in situ FTIR with different probe molecules. Compared to the previously established MgFâ‚‚, weaker Lewis acid sites are predominant on the surface of ZnF2 with some base sites, indicating its potential as a heterogeneous catalyst component. In short, we believe that the successful synthesis and detailed characterisation of nanoscopic ZnFâ‚‚ allow follow-up work exploring its applications, and will lead to studies of more metal fluorides with similar methods
Durchflusskennwerte und Querbauwerke: Leitfaden zur Web-Anwendung „Ausgewählte Durchflusskennwerte und Querbauwerke sächsischer Fließgewässer, Stand 2015“
Der Leitfaden informiert über Methodik und Ergebnisse der Regionalisierung von ausgewählten Durchflusskennwerten. Über die Internet-Anwendung »Durchflusskennwerte und Querbauwerke« können für beliebige Querschnitte der sächsischen Fließgewässer die Durchflusskennwerte abgefragt werden (Stand 2015). Die Kennwerte werden u. a. benötigt bei der Ermittlung von Mindestwasserführungen und mittleren Durchflussdargeboten sowie bei der Planung wasserbaulicher Anlagen und der Ausweisung von Überschwemmungsgebieten. Die Publikation richtet sich an Wasserbehörden und Planungsbüros, aber auch an Gewässernutzer in Sachsen.
Redaktionsschluss: 21.06.201
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