237 research outputs found

    Wie wirken "effektive Mikroorganismen" auf EM-Bokashi in der Bananenproduktion (Musa ssp.)?

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    In Costa Rica, ‘effective microorganisms’ (EM) are used to produce organic fertiliser in the form of Bokashi. This study aimed at investigating the effects of EM addition on the decomposition of banana residues during Bokashi production in comparison to different non-EM control variants (Bokashi produced with: W= water, M= molasses as an EM additive, EMst= sterilized EM). Furthermore, the effects of the above mentioned Bokashi variants on the growth of young banana plants and their effects on the secondary root growth of adult banana plants were evaluated. In comparison to non-EM controls, no increasing effects of EM on the N-mineralization of banana material were observed. All nutrient concentrations were similar for all treatments as well as the weight loss of approximately 77.9 %. The ergosterol concentration was significantly highest in EM Bokashi (77 µg g-1 dry soil), whereas it was lowest in EMst (29 µg g-1 dry soil). Application of all Bokashi variants significantly increased shoot growth of young banana plants under greenhouse conditions compared to a control grown in unamended soil. EM Bokashi and Bokashi produced with molasses significantly decreased the number of root nematodes under greenhouse conditions if compared to the control (nematodes per 100 g: C = 254; W = 143; EMst = 143; M = 67; EM = 38). Furthermore, EM Bokashi increased secondary root growth of adult banana plants in the field (186.7 g) compared to non-composted fresh banana leaves (134.6 g) and a control without mulch application (147 g)

    Mechanism of Carrier Generation in Poly(phenylene vinylene): Transient Photoconductivity and Photoluminescence at High Electric Fields

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    The carrier generation mechanism in poly(phenylene vinylene), is addressed by studying the transient photoconductivity and the photoluminescence as a function of the external electric field E in samples oriented by tensile drawing. The transient photocurrent is proportional to E at low fields, but increases nonlinearly for E>105 V/cm. The field at which the photoconductivity becomes nonlinear (the onset field, E0pc) depends on the degree of alignment: the higher the draw ratio, the lower E0pc. The dependence of the photocurrent on E is similar to the dependence of the dark current on E; both imply a field-dependent mobility (rather than field-dependent carrier generation). The onset field for the nonlinear photoconductivity is, however, different from the onset field for quenching the luminescence (E0pl). Thus, contrary to expectations for strongly bound neutral excitons as the elementary excitations, the high-field increase in photocurrent and the corresponding decrease in photoluminescence are not proportional, indicating that field-induced carrier generation is not significant

    Engineering Genetically Encoded Nanosensors for Real-Time In Vivo Measurements of Citrate Concentrations

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    Citrate is an intermediate in catabolic as well as biosynthetic pathways and is an important regulatory molecule in the control of glycolysis and lipid metabolism. Mass spectrometric and NMR based metabolomics allow measuring citrate concentrations, but only with limited spatial and temporal resolution. Methods are so far lacking to monitor citrate levels in real-time in-vivo. Here, we present a series of genetically encoded citrate sensors based on Förster resonance energy transfer (FRET). We screened databases for citrate-binding proteins and tested three candidates in vitro. The citrate binding domain of the Klebsiella pneumoniae histidine sensor kinase CitA, inserted between the FRET pair Venus/CFP, yielded a sensor highly specific for citrate. We optimized the peptide linkers to achieve maximal FRET change upon citrate binding. By modifying residues in the citrate binding pocket, we were able to construct seven sensors with different affinities spanning a concentration range of three orders of magnitude without losing specificity. In a first in vivo application we show that E. coli maintains the capacity to take up glucose or acetate within seconds even after long-term starvation

    Determining the neurotransmitter concentration profile at active synapses

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    Establishing the temporal and concentration profiles of neurotransmitters during synaptic release is an essential step towards understanding the basic properties of inter-neuronal communication in the central nervous system. A variety of ingenious attempts has been made to gain insights into this process, but the general inaccessibility of central synapses, intrinsic limitations of the techniques used, and natural variety of different synaptic environments have hindered a comprehensive description of this fundamental phenomenon. Here, we describe a number of experimental and theoretical findings that has been instrumental for advancing our knowledge of various features of neurotransmitter release, as well as newly developed tools that could overcome some limits of traditional pharmacological approaches and bring new impetus to the description of the complex mechanisms of synaptic transmission

    Myosin heavy chain and physiological adaptation of the rat diaphragm in elastase-induced emphysema

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    BACKGROUND: Several physiological adaptations occur in the respiratory muscles in rodent models of elastase-induced emphysema. Although the contractile properties of the diaphragm are altered in a way that suggests expression of slower isoforms of myosin heavy chain (MHC), it has been difficult to demonstrate a shift in MHCs in an animal model that corresponds to the shift toward slower MHCs seen in human emphysema. METHODS: We sought to identify MHC and corresponding physiological changes in the diaphragms of rats with elastase-induced emphysema. Nine rats with emphysema and 11 control rats were studied 10 months after instillation with elastase. MHC isoform composition was determined by both reverse transcriptase polymerase chain reaction (RT-PCR) and immunocytochemistry by using specific probes able to identify all known adult isoforms. Physiological adaptation was studied on diaphragm strips stimulated in vitro. RESULTS: In addition to confirming that emphysematous diaphragm has a decreased fatigability, we identified a significantly longer time-to-peak-tension (63.9 ± 2.7 ms versus 53.9 ± 2.4 ms). At both the RNA (RT-PCR) and protein (immunocytochemistry) levels, we found a significant decrease in the fastest, MHC isoform (IIb) in emphysema. CONCLUSION: This is the first demonstration of MHC shifts and corresponding physiological changes in the diaphragm in an animal model of emphysema. It is established that rodent emphysema, like human emphysema, does result in a physiologically significant shift toward slower diaphragmatic MHC isoforms. In the rat, this occurs at the faster end of the MHC spectrum than in humans

    Co-regulation map of the human proteome enables identification of protein functions

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    This is the author accepted manuscript. The final version is available from Nature Research via the DOI in this recordData availability: All mass spectrometry raw files generated in-house have been deposited in the ProteomeXchange Consortium (http://proteomecentral.proteomexchange.org) via the PRIDE partner repository36 with the dataset identifier PXD008888. The co-regulation map is hosted on our website at www.proteomeHD.net, and pair-wise co-regulation scores are available through STRING (https://string-db.org). A network of the top 0.5% co-regulated protein pairs can be explored interactively on NDEx (https://doi.org/10.18119/N9N30Q).Code availability: Data analysis was performed in R 3.5.1. R scripts and input files required to reproduce the results of this manuscript are available in the following GitHub repository: https://github.com/Rappsilber-Laboratory/ProteomeHD. R scripts related specifically to the benchmarking of the treeClust algorithm using synthetic data are available in the following GitHub repository: https://github.com/Rappsilber-Laboratory/treeClust-benchmarking. The R package data.table was used for fast data processing. Figures were prepared using ggplot2, gridExtra, cowplot and viridis.Note that the title of the AAM is different from the published versionThe annotation of protein function is a longstanding challenge of cell biology that suffers from the sheer magnitude of the task. Here we present ProteomeHD, which documents the response of 10,323 human proteins to 294 biological perturbations, measured by isotope-labelling mass spectrometry. We reveal functional associations between human proteins using the treeClust machine learning algorithm, which we show to improve protein co-regulation analysis due to robust selectivity for close linear relationships. Our co-regulation map identifies a functional context for many uncharacterized proteins, including microproteins that are difficult to study with traditional methods. Co-regulation also captures relationships between proteins which do not physically interact or co-localize. For example, co-regulation of the peroxisomal membrane protein PEX11β with mitochondrial respiration factors led us to discover a novel organelle interface between peroxisomes and mitochondria in mammalian cells. The co-regulation map can be explored at www.proteomeHD.net .Biotechnology & Biological Sciences Research Council (BBSRC)European Commissio
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