36 research outputs found
Die EinflĂŒsse der Geopolitik auf Forschung und Theorie der Politischen Geographie von ihren AnfĂ€ngen bis 1945 : Ein Beitrag zur Wissenschaftsgeschichte der Politischen Geographie und ihrer Terminologie unter besonderer BerĂŒcksichtigung von MilitĂ€r- und Kolonialgeographie
Die vorliegende Arbeit ist als Dissertation am Institut fĂŒr Wirtschaftsgeographie der UniversitĂ€t [Bonn] entstanden. Sie basiert auf einer intensiven BeschĂ€ftigung mit der deutschen Geschichte der Neuzeit sowie mit Themen der Politischen Geographie im Rahmen des Studiums der FĂ€cher Geschichte, Politologie und Geographie in Heidelberg und Bonn
First report of aster-yellows disease in carrots and in the leafhopper Macrosteles sexnotatus (FallĂ©n 1806) in Germany â monitoring and diagnosis
Im Jahr 2011 gelang es dem LTZ Augustenberg (Baden-WĂŒrttemberg) erstmals in Deutschland ein Phytoplasma aus der âAster Yellowsâ-Gruppe an Möhren nachzuweisen. Durch die Sequenzierung des PCR-Amplifikats konnte der Erreger als Candidatus Phytoplasma asteris identifiziert werden. Etwa zwei Prozent der Möhren eines Anbauers zeigten im Jahr 2011 die typischen Symptome wie RotfĂ€rbung des Laubes, am RĂŒbenkörper eine verstĂ€rkte Feinwurzelbildung und verlĂ€ngerte Wurzelenden. Als ĂbertrĂ€ger von Phytoplasmen gelten unter anderem Kleinzikaden. Daraufhin wurde in den Jahren 2012 bis 2014 ein Monitoring-Programm durchgefĂŒhrt. Die potentiellen Vektoren, Kleinzikaden der Gattung Macrosteles, wurden zum einen mit Keschern gefangen und morphologisch auf die Arten bestimmt, zum anderen wurde mittels gelber Leimtafeln der Flugverlauf der Zikaden dokumentiert. AnschlieĂend wurden die so gefangenen Macrosteles-Zikaden anhand PCR auf Phytoplasmen untersucht. Im Durchschnitt der untersuchten drei Jahre waren die mittels Leimtafeln gefangenen Zikaden der Gattung Macrosteles zu 3,3% mit Phytoplasmen infiziert. Dabei blieb der Anteil an befallenen Möhren in allen drei Untersuchungsjahren unter einem Prozent.Der Anteil der mittels gelben Leimtafeln gefangenen Macrosteles-Arten am Gesamtfang betrug im Durchschnitt der Jahre ca. 18 Prozent. Morphologisch konnten die mit Kescher gefangenen Macrosteles-Zikaden den Arten MacroÂsteles sexnotatus, M. laevis, M. cristatus und M. ossiannilssoni zugeordnet werden. Mit ca. 70% war M. sexnotatus dabei die hĂ€ufigste Art. Die Arten M. laevis und M. cristatus machten ca. je 15% aus. Der Anteil der Art M. ossiannilssoni betrug nur ca. zwei Prozent.Auch bei den von den gelben Leimtafeln isolierten Macrosteles-Zikaden mit Nachweis von Phytoplasmen konnte M. sexnotatus mit molekularbiologischen Methoden mit 85,7% als die hĂ€ufigste Art identifiziert werden. Ferner konnten die in M. sexnotatus nachgewiesenen Phytoplasmen der âAster-yellowsâ-Gruppe zugeordnet werden. Die Kleinzikadenart M. sexnotatus spielt nach den vorliegenden Ergebnissen eine groĂe Rolle bei der Ăbertragung von âAster-Yellowsâ (phytoplasmenbedingte Möhrenröte) im Untersuchungsgebiet und damit vermutlich in Baden-WĂŒrttemberg und Deutschland. Mit den im Feld aufgestellten gelben Leimtafeln lieĂ sich der Flugverlauf der Zikaden dokumentieren. Demnach erstreckt sich die Flugzeit der Macrosteles-Arten von Mitte Mai (Kalenderwoche 21) bis Mitte November (Kalenderwoche 46). Der frĂŒhe Nachweis von Phytoplasmen in den Zikaden bedeutet, dass die Tiere bereits infiziert sind, wenn sie in den Möhrenfeldern auftreten. Noch nicht geklĂ€rt ist die Herkunft der Macrosteles-Arten. Ein Zuflug ist sowohl von den die Möhrenfelder umgebenden Habitaten (RiedflĂ€chen und Wiesen), als auch von weiter entfernten Gebieten denkbar. Des Weiteren ist noch nicht geklĂ€rt, wo und an welchen Wirtspflanzen die Zikaden bei ihrer Migration von ihren Ăberwinterungspflanzen zu den Möhrenfeldern die Phytoplasmen aufnehmen. DOI: 10.5073/JfK.2016.10.01, https://doi.org/10.5073/JfK.2016.10.01A phytoplasma of the âaster-yellowsâ-group was detected in carrots by the Center for Agricultural Technology Augustenberg (LTZ Augustenberg in the federal state of Baden-WĂŒrttemberg) in the year 2011. It could be identified as Candidatus Phytoplasma asteris by sequence anaÂlysis of the PCR-amplification product. This is the first report about this disease in Germany. Nearly two per cent of the carrots were infected and showed the typical red coloring of the foliage. The roots also showed characteÂristic symptoms of increased root hairs and abnormal root growth. Therefore, a monitoring-program was started, which lasts from 2012 until 2014 (3 years). The potential vectors, leafhoppers from the genus Macrosteles, were captured by sweep nets and were dedicated afterwards. Furthermore the migration of the leafhoppers was monitored by the use of yellow sticky traps. After that, the captured leafhoppers were investigated by PCR-based DNA test. Within these tests, âaster-yellowsâ was confirmed in leafhoppers of the genus Macrosteles. On average, 3.3 per cent of specimens collected in the 3 years were infected with âaster yellowsâ phytoplasma. Within all leafhoppers captured, Macrosteles species extended to about 18 per cent. These species were M. sexnotatus, M. laevis, M. cristatus und M. ossiannilssoni. Thereby nearly 70 per cent of the captured Macrosteles species were M. sexnotatus, followed by M. laevis und M. cristatus, each represented about 15 per cent. Only 2 per cent of the Macrosteles species belonged to M. ossiannilssoni. Within the Macrosteles-leafhoppers which were infected with aster-yellows, 85.7 per cent belonged to the species M. sexnotatus. Therefore it is evident, that the common and wide spread leafhopper M. sexnotatus is able to transmit aster-yellows in Germany. It is very easily to detect leafhoppers in the field by using yellow sticky traps. It is also possible to document the migration of the leafhoppers by using these traps. The period of migration of the leafhoppers lasts from the middle of May to the middle of September. The captured Macrosteles were infected by aster-yellows very early in the season. This means, that the Macrosteles population must have infected itself on different herbs by their migration from their overwintering areas to the carrot fields. Up to now, it is not known, where the Macrosteles species originate from. A migration from the surrounding area is also possible, than the migration from areas far from the carrot fields. It is also unknown, where and on which herbs the leafhoppers infect themselves with âaster-yellowsâ phytoplasma. DOI: 10.5073/JfK.2016.10.01, https://doi.org/10.5073/JfK.2016.10.0
Risk factors for bacterial catheter colonization in regional anaesthesia
BACKGROUND: Although several potential risk factors have been discussed, risk factors associated with bacterial colonization or even infection of catheters used for regional anaesthesia are not very well investigated. METHODS: In this prospective observational trial, 198 catheters at several anatomical sites where placed using a standardized technique. The site of insertion was then monitored daily for signs of infection (secretion at the insertion site, redness, swelling, or local pain). The catheters were removed when clinically indicated (no or moderate postoperative pain) or when signs of potential infection occurred. After sterile removal they were prospectively analyzed for colonization, defined as > 15 colony forming units. RESULTS: 33 (16.7%) of all catheters were colonized, and 18 (9.1%) of these with additional signs of local inflammation. Two of these patients required antibiotic treatment due to superficial infections. Stepwise logistic regression analysis was used to identify factors associated with catheter colonization. Out of 26 potential factors, three came out as statistically significant. Catheter placement in the groin (odds-ratio and 95%-confidence interval: 3.4; 1.5â7.8), and repeated changing of the catheter dressing (odds-ratio: 2.1; 1.4â3.3 per removal) increased the risk for colonization, whereas systemic antibiotics administered postoperatively decreased it (odds ratio: 0.41; 0.12â1.0). CONCLUSION: Colonization of peripheral and epidural nerve catheter can only in part be predicted at the time of catheter insertion since two out of three relevant variables that significantly influence the risk can only be recorded postoperatively. Catheter localisation in the groin, removal of the dressing and omission of postoperative antibiotics were associated with, but were not necessarily causal for bacterial colonization. These factors might help to identify patients who are at increased risk for catheter colonization
Varicella Viruses Inhibit Interferon-Stimulated JAK-STAT Signaling through Multiple Mechanisms
Varicella zoster virus (VZV) causes chickenpox in humans and, subsequently, establishes latency in the sensory ganglia from where it reactivates to cause herpes zoster. Infection of rhesus macaques with simian varicella virus (SVV) recapitulates VZV pathogenesis in humans thus representing a suitable animal model for VZV infection. While the type I interferon (IFN) response has been shown to affect VZV replication, the virus employs counter mechanisms to prevent the induction of anti-viral IFN stimulated genes (ISG). Here, we demonstrate that SVV inhibits type I IFN-activated signal transduction via the JAK-STAT pathway. SVV-infected rhesus fibroblasts were refractory to IFN stimulation displaying reduced protein levels of IRF9 and lacking STAT2 phosphorylation. Since previous work implicated involvement of the VZV immediate early gene product ORF63 in preventing ISG-induction we studied the role of SVV ORF63 in generating resistance to IFN treatment. Interestingly, SVV ORF63 did not affect STAT2 phosphorylation but caused IRF9 degradation in a proteasome-dependent manner, suggesting that SVV employs multiple mechanisms to counteract the effect of IFN. Control of SVV ORF63 protein levels via fusion to a dihydrofolate reductase (DHFR)-degradation domain additionally confirmed its requirement for viral replication. Our results also show a prominent reduction of IRF9 and inhibition of STAT2 phosphorylation in VZV-infected cells. In addition, cells expressing VZV ORF63 blocked IFN-stimulation and displayed reduced levels of the IRF9 protein. Taken together, our data suggest that varicella ORF63 prevents ISG-induction both directly via IRF9 degradation and indirectly via transcriptional control of viral proteins that interfere with STAT2 phosphorylation. SVV and VZV thus encode multiple viral gene products that tightly control IFN-induced anti-viral responses
Regionalanalysen in der Studienfoerderung
Available from Bibliothek des Instituts fuer Weltwirtschaft, ZBW, Duesternbrook Weg 120, D-24105 Kiel A 166124 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman