1,218 research outputs found
Entwicklung von BekĂ€mpfungsstrategien fĂŒr Meloidogyne halpa und Pratylenchus spp. im ökologischen Anbau von Möhren und Zwiebeln
Nematoden der Gattungen Meloidogyne und Pratylenchus zĂ€hlen zu den Hauptschaderregern im ökologischen Anbau von Möhren und Zwiebeln. Typische Symptome sind geringes Wachstum, Deformationen der Ernteorgane, verstĂ€rkte Seitenwurzelbildung sowie Wurzelgallen (Meloidogyne) bzw. WurzellĂ€sionen (Pratylenchus). Beide Nematodengattungen haben ein sehr weites Wirtspflanzenspektrum und treten hĂ€ufig gemeinsam auf. In dem vorliegenden Forschungsvorhaben werden BekĂ€mpfungsstrategien fĂŒr Meloidogyne und Pratylenchus unter praxisĂŒblichen 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 â10 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 fĂŒr 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 extracellular matrix of the spleen as a potential organizer of immune cell compartments
Until recently little information was available on the molecular details of the extracellular matrix (ECM) of secondary lymphoid tissues. There is now growing evidence that these ECMs are unique structures, combining characteristics of basement membranes and interstitial or fibrillar matrices, resulting in scaffolds that are strong and highly flexible and, in certain secondary lymphoid compartments, also forming conduit networks for rapid fluid transport. This review will address the structural characteristics of the ECM of the murine spleen and its potential role as an organizer of immune cell compartments, with reference to the lymph node where relevant
The 125th anniversary of the first postulation of the soil origin of endophytic bacteria â 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 (â38%), abundance (â53%) and biomass (â57%) 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
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 maleâfemale 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 germâsoma division of labor and maleâfemale 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
The bending of cell sheets - from folding to rolling
The bending of cell sheets plays a major role in multicellular embryonic morphogenesis. Recent advances are leading to a deeper understanding of how the biophysical properties and the force-producing behaviors of cells are regulated, and how these forces are integrated across cell sheets during bending. We review work that shows that the dynamic balance of apical versus basolateral cortical tension controls specific aspects of invagination of epithelial sheets, and recent evidence that tissue expansion by growth contributes to neural retinal invagination in a stem cell-derived, self-organizing system. Of special interest is the detailed analysis of the type B inversion in Volvox reported in BMC Biology by Höhn and Hallmann, as this is a system that promises to be particularly instructive in understanding morphogenesis of any monolayered spheroid system
- âŠ