Population dynamics and pathogenicity of Bursaphelenchus xylophilus in seven- to eight-year-old Pinus sylvestris trees

Der Kiefernholznematode, Bursaphelenchus xylophilus, ist der schädlichste pflanzenparasitäre Nematode an Bäumen in Asien und Europa und führt bei anfälligen Koniferenarten, hauptsächlich Pinus spp., zur sogenannten Kiefernwelkekrankheit. Die Krankheit ist lediglich außer­halb seines natürlichen Verbreitungsgebietes (Nordamerika) oder an nicht einheimischen Kiefernarten aufgetreten. In Gewächshausversuchen mit Sämlingen war Pinus sylvestris eine der anfälligsten europäischen Kiefern­arten. Um die Aussagefähigkeit dieser auf Sämlingen basieren­den Analysen bezüglich der Populationsdynamik und der Pathogenität für erwachsene P. sylvestris Bäume zu überprüfen, wurden Untersuchungen an sieben- bis achtjährigen Bäumen durchgeführt. Die Bäume wurden mit einer Suspension bestehend aus 10.000 B. xylophilus in 600 μl Leitungswasser pro Baum künstlich inokuliert. Für die Populationsdynamikuntersuchung wurden die Kiefern zur Nematodenextraktion in 48 Segmente geteilt. Die Entwicklung der Welkesymptome und physiologischen Änderungen wurden bis zum Tod der Bäume beobachtet.Während der Populationsdynamikuntersuchung war B. xylophilus in den ersten 11 Tagen nach Inokulation in der Inokulationsstelle und den benachbarten Segmenten lokalisiert. Am Tag 16 war B. xylophilus im gesamten Stamm, den benachbarten Astsegmenten, Wurzelhals und Wurzeln verteilt, noch bevor äußere Welkesymptome erschienen. Mit zunehmender Kiefernwelkeerkrankung war B. xylophilus schließlich in allen Holz- und Wurzelsegmenten zu finden. Hohe Nematodendichten traten auf. Kurz vor dem vollständigen Absterben der Bäume zeigte die Baumspitze mehrere nematodenfreie Segmente. Die restlichen Stamm- und benachbarten Astsegmente und der Wurzelhals waren in hohem Maße mit Nematoden befallen. Während der Pathogenitätsuntersuchung starben alle B. xylophilus-inokulierten Kiefern innerhalb von 84 Tagen. Der signifikante Abfall des Wasserpotentials in den Nadeln war steiler und stärker mit den zunehmenden Welkesymptomen korreliert als bei einer trocken­gestressten Vergleichsvariante. Der Abfall des Wasser­potentials in den Nadeln trat jedoch bei der trocken­gestressten Kiefernvariante früher ein. Schlussfolgend betrachtet waren die Populationsdynamik von B. xylophilus in sieben- bis achtjährigen P. sylvestris Bäumen und die pathologischen Reaktionen der Kiefern vergleichbar zu denen in Sämlingsuntersuchungen, auch wenn das Erreichen eines Populationsmaximums und die Entwicklung von Welkesymptomen zeitlich verzögert waren. Aus diesem Grund sind P. sylvestris Sämlinge gute Indikatorbäume für B. xylophilus Populationsdynamik- und Pathogenitätsuntersuchungen.The pinewood nematode, Bursaphelenchus xylophilus, is the most harmful plant parasitic nematode on trees in Asia and Europe and is the causal agent of the so-called pine wilt disease of susceptible conifer species, mainly Pinus spp. The disease has occurred only outside its natural range of distribution (North America) or on non-native pine species. In greenhouse trials using saplings, Pinus sylvestris was one of the most susceptible European pine species. To examine the significance of these sapling-based analyses concerning the population dynamics and pathogenicity for mature P. sylvestris trees, investigations using seven- to eight-year-old trees were carried out. The trees were artificially inoculated using a suspension of 10,000 B. xylophilus in 600 μl of tap water per tree. For the population dynamics investigation, the pines were divided into 48 segments for nematode extraction. The development of wilt symptoms as well as physiological changes were observed until tree death.During the population dynamics investigation, B. xylophilus was located at the inoculation site and in adjacent segments during the first 11 days after inoculation. On day 16, B. xylophilus was distributed throughout the entire stem, adjacent branch segments, root collar and roots before any external wilt symptoms appeared. With increasing pine wilt disease, B. xylophilus was finally found in all wood and root segments. High nematode densities appeared. Shortly before tree death, the treetop showed several nematode-free segments. The rest of the stem and adjacent branch segments and root collar were highly nematode-infested. During the pathogenicity investigation, all B. xylophilus-inoculated pines died within 84 days. The significant decline in the water potential in the needles was steeper and more strongly correlated with increasing wilt symptoms compared to a drought-stressed variant. However, the decline in the water potential in the needles started earlier in the drought-stressed pine variant. In conclusion, the population dynamics of B. xylophilus in seven- to eight-year-old P. sylvestris trees and the pathological reactions of the pines were comparable to those observed in assays with saplings, although delayed in reaching a population peak and developing wilt symptoms. Therefore, P. sylvestris saplings are good indicator trees for B. xylophilus population dynamics and pathogenicity investigations

Chapter The EU Research Project PLANET

Renewable energy sources offer unprecedented opportunities to reduce greenhouse gas emissions. But some challenges remain to be solved before their full benefits can be reaped. The main one relates to the intermittency of their electricity supply which can lead to grid problems such as congestion and imbalance between generation and demand. Energy conversion and storage has been touted as a very promising solution to all aforementioned issues. PLANET will develop a holistic decision support system for the optimal orchestration of the different energy networks for aggregators and balance responsible parties, policy makers and network operators. It will aid them to leverage innovative energy conversion in alternative carriers and storage technologies in order to explore, identify, evaluate and quantitatively assess optimal grid planning and management strategies for future energy scenarios targetting full energy system decarbonization. Moreover, an analysis of the possible synergies between electricity, gas and heat networks will be carried out by creating simulation models for the integration between energy networks and conversion/storage technologies, for example power-to-gas, power-to-heat and virtual thermal energy storage. Application of the developed tools in two different test cases in Italy and France will showcase their benefits and reveal potential grid stability issues and effective countermeasures

GTP-dependent Ca2+ release from rat liver microsomes Vesicle fusion is not required

AbstractThe GTP-dependent calcium release from rat liver microsomes is known to be promoted in the presence of colloids like polyethyleneglycol (PEG), polyvinylpyrrolidine, or albumin. Dawson et al. [(1987) Biochem. J. 244, 87–92] using the ‘fusogen’ PEG have concluded that both GTP-induced calcium efflux and the enhancement of InsP3-promoted calcium release in the presence of GTP could be attributed to a GTP-dependent vesicle fusion. Here, using the more physiological colloid albumin we report that GTP-induced calcium release from rat liver microsomes may not be linked to vesicle fusion

Risikomessung mit Shortfall-Maßen : das Programm MAMBA - Metzler Asset Management Benchmark Analyzer

Im Jahre 1952 begann die Entwicklung der Portfolio-Theorie durch einen wegweisenden Artikel von Harry Markowitz. Die Portfolio-Theorie und darauf aufbauende Theorien wie das Capital Asset Pricing Model haben seit dieser Zeit die Welt des Investment-Banking erobert und zählen zu den klassischen Fundamenten solider Kapitalanlageentscheidungen. Im Jahre 1952 erschien ebenfalls der Artikel von A. D. Roy, der die Grundlagen zu einem allgemeineren Konzept der Theorie der Kapitalanlage legte Roy ging davon aus, daß ein Investor dasjenige Portfolio bevorzugt, bei dem die geringste Wahrscheinlichkeit rur die Unterschreitung einer gewünschten Mindestrendite besteht. Das Konzept von Roy kann damit als Vorläufer des Shortfall-Ansatzes betrachtet werden. Der Shortfall-Ansatz hat als Ausgangspunkt, daß ein Investor unter Risiko die Möglichkeit der Unterschreitung einer Mindestrendite versteht. Im Gegensatz zur Varianz bzw. Standardabweichung wird Risiko damit nicht symmetrisch um den mittleren Ertrag einer Kapitalanlage gemessen, sondern immer nur unterhalb der gewählten Mindestrendite. Diese plausible und intuitiv leicht verständliche Auffassung von Risiko erfuhr vor·allem durch die Arbeiten von Bawa eine entscheidungstheoretische Fundierung und es zeigte sich, daß der Shortfall-Ansatz als Verallgemeinerung des Markowitz-Ansatzes betrachtet werden kann. Von besonderem Interesse rur den praktischen Nutzen des Shortfall-Ansatzes ist dessen Anwendbarkeit auf Optionsportfolios. Portfolios, die einen größeren Anteil an Optionen enthalten, können mit dem Markowitz-Ansatz nicht mehr zufriedenstellend analysiert werden, da die Portfoliorenditen erheblich von der Normalverteilung abweichen. Für diesen allgemeinen Fall ist jedoch der Shortfall-Ansatz gut geeignet, da seine Anwendbarkeit nicht von der Verteilung der Portfoliorenditen abhängt. Die zunehmende Verwendung von Optionen im Investment-Banking sollte daher in Zukunft zu einer stärkeren Verwendung des Shortfall-Ansatzes führen. Dies war auch der Ausgangspunkt für die Zusammenarbeit zwischen der Metzler Investment GmbH und dem Zentrum rur Europäische Wirtschaftsforschung. Das in dieser Dokumentation beschriebene Projekt wurde im Auftrag der Metzler Investment GmbH erstellt und von ihr finanziert. Das Projektteam am ZEW besteht aus Dipl. Stat. Olaf Korn, Dr. Michael Schröder (Projektleiter), Dipl. Wi.-Inf. Andrea Szczesny und cand. rer. pol. Viktor Winschel

Sterbehilfe? : der Wert menschlichen Lebens in Björn Kerns Roman "Die Erlöser AG" und in der Ethik Dietrich Bonhoeffers

Master's thesis in Theology. School of Mission and Theology, May 200

The EU Research Project PLANET

Renewable energy sources offer unprecedented opportunities to reduce greenhouse gas emissions. But some challenges remain to be solved before their full benefits can be reaped. The main one relates to the intermittency of their electricity supply which can lead to grid problems such as congestion and imbalance between generation and demand. Energy conversion and storage has been touted as a very promising solution to all aforementioned issues. PLANET will develop a holistic decision support system for the optimal orchestration of the different energy networks for aggregators and balance responsible parties, policy makers and network operators. It will aid them to leverage innovative energy conversion in alternative carriers and storage technologies in order to explore, identify, evaluate and quantitatively assess optimal grid planning and management strategies for future energy scenarios targetting full energy system decarbonization. Moreover, an analysis of the possible synergies between electricity, gas and heat networks will be carried out by creating simulation models for the integration between energy networks and conversion/storage technologies, for example power-to-gas, power-to-heat and virtual thermal energy storage. Application of the developed tools in two different test cases in Italy and France will showcase their benefits and reveal potential grid stability issues and effective countermeasures

Risikomessung mit Shortfall-Maßen: Das Programm MAMBA - Metzler Asset Management Benchmark Analyser

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Spatial and temporal dynamics of coccolithophore communities during low production phases in the Norwegian-Greenland Sea

The present investigation was initiated to report on species compositions and dynamics in the Norwegian-Greenland Sea during low production phases in spring and early summer. Thus, the distribution patterns of living coccolithophores during June to July, 1990, February and May, 1991, and March to April, 1995 were investigated. In general, the seasonal development of the phytoplankton started after the yearly dark period and coccolithophores increased in abundance when the water column was more stratified and both temperatures and insolation increased. Cell densities reached a maximum of 207x10~c occospheres/l in the southeastern part of the studied area. However, these high cell densities probably resulted from ,,old" populations, drifted to the Norwegian-Greenland Sea from the North Atlantic. Some of the collected samples did not contain any coccolithophores. In total, 15 coccolithophore species were identified. The diversity was generally higher in the eastern part of the Norwegian-Greenland Sea and to the west the coccolithophore communities often were monospecific. Emiliania huxleyi is the dominant species, but Calciopappus caudatus and Algirosphaera robusta also considerably contribute to the communities. High cell densities of C. caudatus were interpreted as the result of a bloom or more probably close to bloom conditions during the general low productive period. In addition, many of the E. huxleyi coccolith from the surface waters of the southeastern Norwegian-Greenland Sea were heavily corroded. These specimens may have drifted within the Atlantic water for a longer time

Sensitivity of Bunker Cave to climatic forcings highlighted through multi-annual monitoring of rain-, soil-, and dripwaters

The last two decades have seen a considerable increase in studies using speleothems as archives of past climate variability. Caves under study are now monitored for a wide range of environmental parameters and results placed in context with speleothem data. The present study investigates trends from a seven year long monitoring of Bunker Cave, northwestern Germany, in order to assess the hydraulic response and transfer time of meteoric water from the surface to the cave. Rain-, soil-, and dripwater were collected from August 2006 to August 2013 at a monthly to bimonthly resolution and their oxygen and hydrogen isotope composition was measured. Furthermore, drip rates were quantified. Due to different drip characteristics, annual mean values were calculated for the drip rates of each drip site. Correlations of the annual mean drip rate of each site with precipitation and infiltration demonstrate that the annual infiltration, and thus the annual precipitation control the inter-annual drip-rate variability for all except one site. The hydraulic response is not delayed on an annual basis. All drip sites display identical long-term trends, which suggests a draining of a common karst reservoir over these seven years of monitoring. Correlations of soil- and dripwater monthly δ18O and δD values with atmospheric temperature data reveal water transfer times of 3 months to reach a depth of 40 cm (soilwater at site BW 2) and 4 months for 70 cm depth (soilwater at site BW 1). Finally, the water reaches the cave chambers (15 to 30 m below land surface) after ca. 2.5 years. Consequently, a temporal offset of 29 to 31 months (ca. 2.5 years) between the hydraulic response time (no time lag on annual basis) and the water transfer time (time lag of 29 to 31 months) was found, which is negligible with regard to Bunker Cave speleothems because of their slow growth rates. Here, proxies recording precipitation/infiltration and temperature are registered on a decadal scale. Variations in drip rate and thus precipitation and infiltration are recorded by δ13C and Mg/Ca ratios in speleothem calcite. Speleothem δ18O values reflect both temperature and precipitation signals due to drip rate-related fractionation processes. We document that long-term patterns in temperature and precipitation are recorded in dripwater patterns of Bunker Cave and that these are linked to the North Atlantic Oscillation (NAO)