90 research outputs found

    Rapid identification of Salmonella by infrared spectroscopy (FTIR) and immunomagnetic separation (IMS)

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    Despite regulatory efforts and emergence of new processing technologies, food-related illnesses remain a major concern for consumers and producers. Since traditional identification methods for foodborne pathogens are time-consuming, rapid, cost-effective detection techniques are needed. The objective was to evaluate the combined use of immunomagnetic separation (IMS) and Fourier-Transform Infrared (FTIR) spectroscopy for detection and identification of Salmonella serovars. Selected Salmonella enterica serovars (Enteritidis, Typhimurium, Heidelberg, Muenchen, Anatum, and Kentucky), were grown to 109 cfu/ml, bound by anti-Salmonella magnetic beads (IMB) and collected using a magnetic particle concentrator, to specifically isolate and concentrate Salmonella. The bacteria-IMB complex was applied onto ZnSe, vacuum-dried and analyzed by attenuated total reflectance (ATR) FTIR. Spectra were compared by soft independent modeling of class analogy (SIMCA) for Salmonella differentiation. Salmonella bound to IMB had distinctive and reproducible infrared spectra, opposed to unbound IMB. However, the signal of the IMB distorted bacterial bands in the fingerprint region. Sonication and centrifugation lysed the cells, and isolated the cell wall components. Infrared spectra analysis (1300-900 cm-1) of the cell lysate, using SIMCA, permitted the separation of Salmonella into well-defined clusters with differentiation among serovars due to differences in cell envelope lipopolysaccharides (LPS). Application of IMS and IR microspectrometry, in combination with hydrophobic grid membranes allowed identification of Salmonella (103 cfu/ml) within 12 hours of incubation. This technology would allow isolation and identification of pathogenic bacteria in contaminated food matrices, minimizing false-positive results due to cross-reactions, and improving food safety and quality assurance.OARDC Seed Progra

    The DWD climate predictions website: Towards a seamless outlook based on subseasonal, seasonal and decadal predictions

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    The climate predictions website of the Deutscher Wetterdienst (DWD, https://www.dwd.de/climatepredictions) presents a consistent operational outlook for the coming weeks, months and years, focusing on the needs of German users. At global scale, subseasonal predictions from the European Centre of Medium-Range Weather Forecasts as well as seasonal and decadal predictions from the DWD are used. Statistical downscaling is applied to achieve high resolution over Germany. Lead-time dependent bias correction is performed on all time scales. Additionally, decadal predictions are recalibrated. The website offers ensemble mean and probabilistic predictions for temperature and precipitation combined with their skill (mean squared error skill score, ranked probability skill score). Two levels of complexity are offered: basic climate predictions display simple, regionally averaged information for Germany, German regions and cities as maps, time series and tables. The skill is presented as traffic light. Expert climate predictions show complex, gridded predictions for Germany (at high resolution), Europe and the world as maps and time series. The skill is displayed as the size of dots. Their color is related to the signal in the prediction. The website was developed in cooperation with users from different sectors via surveys, workshops and meetings to guarantee its understandability and usability. The users realize the potential of climate predictions, but some need advice in using probabilistic predictions and skill. Future activities will include the further development of predictions to improve skill (multi-model ensembles, teleconnections), the introduction of additional products (data provision, extremes) and the further clarification of the information (interactivity, video clips)

    Oxide nanotemplates for self-assembling "solid" building blocks

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    It is widely accepted that self-assembling building blocks is one of the promising ways for engineering new materials. Recent years reveal substantial progress in fabricating colloidal particles, polymer blocks and supramolecular aggregates of organic molecules. Despite of substantial progress in molecular self-assembly there is still a lack of simple blocks made of "solid matter" (e.g. metals, oxides etc.) with well-defined crystal structure and spatial order. Here we demonstrate that ordered arrays of metal nanoclusters can be fabricated by self-assembly on a wide range of oxide templates. These nano-templates are produced either by depositing an alien oxide film or by oxidizing a metal/metal oxide substrate.Comment: 11 pages, 2 figures added DFT calculations and Fig.

    Effect of disorder on a pressure-induced z = 1 magnetic quantum phase transition

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    Pressure-induced ordering close to a z=1 quantum-critical point is studied in the presence of bond disorder in the quantum spin system (C4H12N2)Cu2(Cl1−xBrx)6 (PHCX) by means of muon-spin rotation and relaxation. As for the pure system (C4H12N2)Cu2Cl6, pressure allows PHCX with small levels of disorder (x≤7.5%) to be driven through a quantum-critical point separating a low-pressure quantum paramagnetic phase from magnetic order at high pressures. However, the pressure-induced ordered state is highly inhomogeneous for disorder concentrations x>1%. This behavior might be related to the formation of a quantum Griffiths phase above a critical disorder concentration 7.5

    Lower serum levels of IL-1β and IL-6 cytokines in adolescents with anorexia nervosa and their association with gut microbiota in a longitudinal study

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    Introduction Anorexia nervosa (AN) is an often chronic and debilitating psychiatric disease whose etiology is not completely understood. Recently, a potential role of inflammation has emerged in other psychiatric diseases, such as depression, PTSD and schizophrenia. The first results in adults with AN seemed to confirm a low-grade proinflammatory state until recent studies presented more differential findings. Studying adolescents with a shorter illness duration and fewer confounding factors might help elucidate the role of inflammation in the underlying pathophysiology of AN; however, the few available studies in adolescents remain ambiguous, and no longitudinal data are available in this age range. Results TNF-α serum levels were significantly elevated in patients with AN at admission, while IL-1β and IL-6 levels were lower at admission and discharge than in HC. After treatment, we also found significantly elevated levels of IL-6 Rα compared to HC, while IL-15 did not show significant changes. Exploratory analyses revealed positive associations of cytokine and genus-level changes between admission and discharge for IL-1β (Bacteroides) and IL-15 (Romboutsia), and negative associations for IL-15 (Anaerostipes) and TNF-α (uncultured Lachnospiraceae). Conclusion We confirmed a previous finding of elevated levels of TNF-α also in adolescents with AN; however, the reduced IL-1β and IL-6 levels differed from the mostly increased levels found in adults. A mixed pro- and anti-inflammatory state appears to be present in adolescents, potentially due to their shorter illness duration. The gut microbiota, with its regulatory function on cytokine production, might play a role in mediating these inflammatory processes in AN and could offer targets for new therapeutic approaches

    High-Resolution Decadal Drought Predictions for German Water Boards: A Case Study for the Wupper Catchment

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    Water boards in Germany require decadal predictions to develop optimized management and adaptation strategies, especially within the claims of flood protection and water distribution management. Specifically, the Wupper catchment water board in western Germany is interested in decadal predictions of drought indices, which are correlated to dam water levels. For the management of small catchments, they need multi-year means and multi-year seasonal means of the hydrological seasons for forecast years 1–3 at high spatial resolution. Thus, the MPI-ESM-LR global decadal prediction system with 16 ensemble members at 200 km resolution was statistically downscaled with EPISODES to ~11 km in Germany. Simulated precipitation was recalibrated, correcting model errors and adjusting the ensemble spread. We tested different recalibration settings to optimize the skill. The 3-year mean and 3-year seasonal mean SPI (Standardized Precipitation Index), indicating excess or deficit of precipitation, was calculated. We evaluated the prediction skill with HYRAS observations, applying skill scores and correlation coefficients, and tested the significance of the skill at a 95% level via 1,000 bootstraps. We found that the high-resolution statistical downscaling is able to preserve the skill of the global decadal predictions and that the recalibration can clearly improve the precipitation skill in Germany. Multi-year annual and August–October mean SPI predictions are promising for several regions in Germany. Additionally, there is potential for skill improvement with increasing ensemble size for all temporal aggregations, except for November–January. A user-oriented product sheet was developed and published on the Copernicus Climate Change Service website (https://climate.copernicus.eu/decadal-predictions-infrastructure). It provides 3-year mean probabilistic SPI predictions for the Wupper catchment and north-western Germany. For 2021–2023, a high probability of negative SPI (dry conditions) is predicted in most of the area. The decadal prediction skill is higher than using the observed climatology as reference prediction in several parts of the area. This case study was developed in cooperation with the Wupper catchment water board and discussed with further German water managers: The skill of high-resolution decadal drought predictions is considered to be promising to fulfill their needs. The product sheet is understandable, well-structured and can be applied to their working routines
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