Entwicklung von Bekämpfungsstrategien für Meloidogyne halpa und Pratylenchus spp. im ökologischen Anbau von Möhren und Zwiebeln

Nematoden der Gattungen Meloidogyne und Pratylenchus zählen zu den Hauptschaderregern im ökologischen Anbau von Möhren und Zwiebeln. Typische Symptome sind geringes Wachstum, Deformationen der Ernteorgane, verstärkte Seitenwurzelbildung sowie Wurzelgallen (Meloidogyne) bzw. Wurzelläsionen (Pratylenchus). Beide Nematodengattungen haben ein sehr weites Wirtspflanzenspektrum und treten häufig gemeinsam auf. In dem vorliegenden Forschungsvorhaben werden Bekämpfungsstrategien für Meloidogyne und Pratylenchus unter praxisüblichen Bedingungen entwickelt

Design and throughput simulations of a hard x-ray split and delay line for the MID station at the European XFEL

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in AIP Conference Proceedings 1741, 030010 (2016) and may be found at https://doi.org/10.1063/1.4952833.A hard X-ray Split and Delay Line (SDL) under development for the Materials Imaging and Dynamics (MID) station at the European X-Ray Free-Electron Laser (XFEL.EU) is presented. This device will provide pairs of X-ray pulses with a variable time delay ranging from −10 ps to 800 ps in a photon energy range from 5 to 10 keV. Throughput simulations in the SASE case indicate a total transmission of 1.1% or 3.5% depending on the operation mode. In the self-seeded case of XFEL.EU operation simulations indicate that the transmission can be improved to more than 11%.BMBF, 05K13KT4, Verbundprojekt FSP 302 - Freie-Elektronen-Laser: Nanoskopische Systeme. Teilprojekt 1: Split-and-Delay Instrument für die European XFEL Beamline Materials Imaging and Dynamic

Development of a hard X-ray split-and-delay line and performance simulations for two-color pump-probe experiments at the European XFEL

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Review of Scientific Instruments 89, 063121 (2018) and may be found at https://doi.org/10.1063/1.5027071.A hard X-ray Split-and-Delay Line (SDL) under construction for the Materials Imaging and Dynamics station at the European X-Ray Free-Electron Laser (XFEL) is presented. This device aims at providing pairs of X-ray pulses with a variable time delay ranging from −10 ps to 800 ps in a photon energy range from 5 to 10 keV for photon correlation and X-ray pump-probe experiments. A custom designed mechanical motion system including active feedback control ensures that the high demands for stability and accuracy can be met and the design goals achieved. Using special radiation configurations of the European XFEL’s SASE-2 undulator (SASE: Self-Amplified Spontaneous Emission), two-color hard x-ray pump-probe schemes with varying photon energy separations have been proposed. Simulations indicate that more than 109 photons on the sample per pulse-pair and up to about 10% photon energy separation can be achieved in the hard X-ray region using the SDL.BMBF, 05K13KT4, Verbundprojekt FSP 302 - Freie-Elektronen-Laser: Nanoskopische Systeme. Teilprojekt 1: Split-and-Delay Instrument für die European XFEL Beamline Materials Imaging and DynamicsBMBF, 05K16BC1, Split-and-Delay Instrument für die European XFEL Beamline Materials Imaging and Dynamic

Mimicking of glutathione peroxidase deficiency by exposition of JAR cells to increased level of synthetic hydroperoxide

A short chain synthetic analogue of lipid hydroperoxides was used to overload glutathione peroxidase (GPx) in human choriocarcinoma cell line JAR cells. Cells exposed to 100 µM tBuOOH displayed a 40% reduction in ATP level and significantly increased in membrane permeability, visualised by the lactate dehydrogenase (LDH) release into the extracellular medium. The intracellular level of oxygen free radicals measured as an oxidation of the dichlorodihydro-fluorescein diacetate (H2DCF-DA) significantly increased after 2 hours of cell exposition to 100 µM tBuOOH. Concomitantly MDA, 4-HNE level increased to 2 nmol/mg of cell protein after 2 hours. Mitochondria stained with MitoTracker Red CMXRos displayed a filamentous appearance in control cells but changed into granular less energised organelles after exposition to tBuOOH. Collectively, the above results indicate the importance of the contribution of oxidative stress in the development of pre-eclampsia

The 125th anniversary of the first postulation of the soil origin of endophytic bacteria – a tribute to M.L.V. Galippe

In both managed and natural ecosystems, a wide range of various non-nodulating bacteria can thrive as endophytes in the plant interior, and some can be beneficial to their hosts (Hallmann and Berg 2007; Reinhold-Hurek and Hurek 2011). Colonizationmechanisms, the ecology and functioning of these endophytic bacteria as well as their interactions with plants have been investigated (Hardoim et al. 2008; Compant et al. 2010). Although the source of colonization can also be the spermosphere, anthosphere, caulosphere, and the phyllosphere,most endophytic bacteria are derived from the soil environment (Hallmann and Berg 2007; Compant et al. 2010)

Host specificity and species colouration mediate the regional decline of nocturnal moths in central European forests

The high diversity of insects has limited the volume of long-term community data with a high taxonomic resolution and considerable geographic replications, especially in forests. Therefore, trends and causes of changes are poorly understood. Here we analyse trends in species richness, abundance and biomass of nocturnal macro moths in three quantitative data sets collected over four decades in forests in southern Germany. Two local data sets, one from coppiced oak forests and one from high oak forests included 125K and 48K specimens from 559 and 532 species, respectively. A third regional data set, representing all forest types in the temperate zone of central Europe comprised 735K specimens from 848 species. Generalized additive mixed models revealed temporal declines in species richness (−38%), abundance (−53%) and biomass (−57%) at the regional scale. These were more pronounced in plant host specialists and in dark coloured species. In contrast, the local coppiced oak forests showed an increase, in species richness (+62%), while the high oak forests showed no clear trends. Left and right censoring as well as cross validation confirmed the robustness of the analyses, which led to four conclusions. First, the decline in insects appears in hyper diverse insect groups in forests and affects species richness, abundance and biomass. Second, the pronounced decline in host specialists suggests habitat loss as an important driver of the observed decline. Third, the more severe decline in dark species might be an indication of global warming as a potential driver. Fourth, the trends in coppiced oak forests indicate that maintaining complex and diverse forest ecosystems through active management may be a promising conservation strategy in order to counteract negative trends in biodiversity, alongside rewilding approaches

Ring closing reaction in diarylethene captured by femtosecond electron crystallography

The photoinduced ring-closing reaction in diarylethene, which serves as a model system for understanding reactive crossings through conical intersections, was directly observed with atomic resolution using femtosecond electron diffraction. Complementary ab initio calculations were also performed. Immediately following photoexcitation, subpicosecond structural changes associated with the formation of an open-ring excited-state intermediate were resolved. The key motion is the rotation of the thiophene rings, which significantly decreases the distance between the reactive carbon atoms prior to ring closing. Subsequently, on the few picosecond time scale, localized torsional motions of the carbon atoms lead to the formation of the closed-ring photoproduct. These direct observations of the molecular motions driving an organic chemical reaction were only made possible through the development of an ultrabright electron source to capture the atomic motions within the limited number of sampling frames and the low data acquisition rate dictated by the intrinsically poor thermal conductivity and limited photoreversibility of organic materials

Evolution of reproductive development in the volvocine algae

The evolution of multicellularity, the separation of germline cells from sterile somatic cells, and the generation of a male–female dichotomy are certainly among the greatest innovations of eukaryotes. Remarkably, phylogenetic analysis suggests that the shift from simple to complex, differentiated multicellularity was not a unique progression in the evolution of life, but in fact a quite frequent event. The spheroidal green alga Volvox and its close relatives, the volvocine algae, span the full range of organizational complexity, from unicellular and colonial genera to multicellular genera with a full germ–soma division of labor and male–female dichotomy; thus, these algae are ideal model organisms for addressing fundamental issues related to the transition to multicellularity and for discovering universal rules that characterize this transition. Of all living species, Volvox carteri represents the simplest version of an immortal germline producing specialized somatic cells. This cellular specialization involved the emergence of mortality and the production of the first dead ancestors in the evolution of this lineage. Volvocine algae therefore exemplify the evolution of cellular cooperation from cellular autonomy. They also serve as a prime example of the evolution of complex traits by a few successive, small steps. Thus, we learn from volvocine algae that the evolutionary transition to complex, multicellular life is probably much easier to achieve than is commonly believed