122 research outputs found
How can we model subsurface stormflow at the catchment scale if we cannot measure it?
Subsurface stormflow (SSF) can be a dominant runâoff generation process in humid mountainous catchments (e.g., Bachmair & Weiler, 2011; Blume & van Meerveld, 2015; Chifflard, Didszun, & Zepp, 2008). Generally, SSF develops in structured soils where bedrock or a less permeable soil layer is overlaid by a more permeable soil layer and vertically percolating water is deflected, at least partially, in a lateral downslope direction due to the slope inclination. SSF can also occur when groundwater levels rise into more permeable soil layers and water flows laterally through the more permeable layers to the stream (âtransmissivity feedback mechanismâ; Bishop, Grip, & O'Neill, 1990). The different existing terms for SSF in the hydrological literature such as shallow subsurface runâoff, interflow, lateral flow, or soil water flow reflects the different underlying process concepts developed in various experimental studies in different environments by using different experimental approaches at different spatial and temporal scales (Weiler, McDonnell, Trompâvan Meerveld, & Uchida, 2005). Intersite comparisons and the extraction of general rules for SSF generation and its controlling factors are still lacking, which hampers the development of appropriate approaches for modelling SSF. But appropriate prediction of SSF is essential due to its clear influence on runâoff generation at the catchment scale (e.g., Chifflard et al., 2010; Zillgens, Merz, Kirnbauer, & Tilch, 2005), on the formation of floods (e.g., Markart et al., 2013, 2015) and on the transport of nutrients or pollutants from the hillslopes into surface water bodies (Zhao, Tang, Zhao, Wang, & Tang, 2013). However, a precise simulation of SSF in models requires an accurate process understanding including, knowledge about water pathways, residence times, magnitude of water fluxes, or the spatial origin of SSF within a given catchment because such factors determine the transport of subsurface water and solutes to the stream. But due to its occurrence in the subsurface and its spatial and temporal variability, determining and quantifying the processes generating SSF is a challenging task as they cannot be observed directly. Therefore, it is logical to ask whether we can really model SSF correctly if we cannot measure it well enough on the scale of interest (Figure 1). This commentary reflects critically on whether current experimental concepts and modelling approaches are sufficient to predict the contribution of SSF to the runâoff at the catchment scale. This applies in particular to the underlying processes, controlling factors, modelling approaches, research gaps, and innovative strategies to trace SSF across different scales
Die Akzeptanz des Fortbildungsabschlusses "GeprĂŒfte BerufspĂ€dagogin/GeprĂŒfter BerufspĂ€dagoge": Studie im Rahmen der Berufsbildungsforschungsinitiative des BMBF
Um den hohen Anforderungen an das betriebliche Bildungspersonal in der beruflichen Aus-, Fort- und Weiterbildung gerecht zu werden und dessen StĂ€rkung sowie Professionalisierung zu ermöglichen, wurden mit der Wiedereinsetzung der Ausbildereignungsverordnung (AEVO) im Jahr 2009 auch zwei bundeseinheitliche Fortbildungsregelungen ("GeprĂŒfte*r Aus- und WeiterbildungspĂ€dagoge*in" auf Fachwirt-/Meister-Ebene und "GeprĂŒfter BerufspĂ€dagoge/GeprĂŒfte BerufspĂ€dagogin") erlassen. Daran geknĂŒpfte Erwartungen eines Professionalisierungsschubs beim auĂerschulischen Bildungspersonal haben sich nicht erfĂŒllt â die (prĂŒfungsstatistische) Nachfrage nach dem Fortbildungsprofil "GeprĂŒfte*r BerufspĂ€dagoge/in" bzw. die Angebote fĂŒr entsprechende VorbereitungslehrgĂ€nge bleiben seit lĂ€ngerem hinter den prognostizierten Erwartungen zurĂŒck. Es fehlen empirische Erkenntnisse ĂŒber die Beurteilung der Fortbildung durch Absolventinnen und Absolventen, ĂŒber die GrĂŒnde, die fĂŒr die Aufnahme dieser Fortbildung ausschlaggebend sind sowie darĂŒber, wie die AttraktivitĂ€t des Fortbildungsprofils gesteigert werden kann. Die im Zeitraum 15. Februar bis 14. Dezember 2018 durchgefĂŒhrte Studie zielte darauf ab, ein Gesamtbild zum Stand des Fortbildungsabschlusses GeprĂŒfte*r BerufspĂ€dagoge*in zu zeichnen, um dessen AttraktivitĂ€t und Akzeptanz einschĂ€tzen zu können. Dazu gehören Erfahrungen der Absolventinnen und Absolventen mit der Fortbildung und mit der beruflichen Verwertbarkeit des Abschlusses. Dazu gehört auch die Sichtweise der Bildungsdienstleister, die die VorbereitungslehrgĂ€nge anbieten sowie der Kammern, die die PrĂŒfungen organisieren und durchfĂŒhren
Improving tuberculosis surveillance by detecting international transmission using publicly available whole genome sequencing data
Improving the surveillance of tuberculosis (TB) is one of the eight core activities identified by the World Health Organization (WHO) and the European Respiratory Society to achieve TB elimination, defined as less than one incident case per million [1]. Monitoring transmission is especially important for multidrug-resistant (MDR) Mycobacterium tuberculosis isolates â defined as being resistant to rifampicin and isoniazid â and for extensively drug-resistant (XDR) M. tuberculosis isolates â defined as MDR isolates with additional resistance to at least one of the fluoroquinolones and at least one of the second-line injectable drugs. In 2017, the WHO estimated that worldwide more than 450,000 people fell ill with MDR-TB and among these, more than 38,000 fell ill with XDR-TB [2].
The rapid advance in molecular typing technology â especially the availability of whole genome sequencing (WGS) to identify and characterise pathogens â gives us the chance to integrate this information into disease surveillance. For TB surveillance, it is possible to combine the results of molecular typing of isolates from the M. tuberculosis complex with traditional epidemiological information to infer or to exclude TB transmission [3,4]. This is of particular relevance if transmission occurs among multiple countries, where epidemiological data such as social contacts are more difficult to get and where data exchange is more difficult to organise. The European Centre for Disease Prevention and Control (ECDC) reported 44 events of international transmission (international clusters) of MDR-TB in different European countries between 2012 and 2015 [5]. In that report, the authors inferred TB transmission using the mycobacterial interspersed repetitive units variable number of tandem repeats (MIRU-VNTR) typing method. However, this method has limitations such as low correlation with epidemiological information in outbreak settings and low discriminatory power [3,6]. In comparison, WGS analysis offers a much higher discriminatory power and allows inferring (or excluding) TB transmission at a higher resolution [4]. In a recent systematic review, van der Werf et al. identified three studies that used WGS to investigate the international transmission of TB [7].
In recent years, the amount of available WGS data is increasing, especially because sequencing has become cheaper [8]. In addition, more and more authors deposit the raw data of their projects in open access public repositories such as the Sequence Read Archive (SRA) of the National Center for Biotechnology Information (NCBI) [9]. These publicly available raw WGS data for thousands of isolates enable the re-use and the additional analyses at a large and global scale [10]. For example, it is possible to compare genomic data among different studies or countries since the data are available in a single place. Moreover, new software tools can be tested using the same raw WGS data [11]. However, standards in bioinformatics analysis and interpretation of these WGS data for surveillance purposes are not yet fully established [12].
We aimed to assess the usefulness of raw WGS data of global MDR/XDR M. tuberculosis isolates available in public repositories to improve TB surveillance. Specifically, we wanted to identify potential international events of TB transmission and to compare the international isolates with a collection of M. tuberculosis isolates collected in Germany in 2012 and 2013.Peer Reviewe
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Optimizing the detection, ablation, and ion extraction efficiency of a single-particle laser ablation mass spectrometer for application in environments with low aerosol particle concentrations
The aim of this study is to show how a newly developed aerodynamic lens system (ALS), a delayed ion extraction (DIE), and better electric shielding improve the efficiency of the Aircraft-based Laser ABlation Aerosol MAss spectrometer (ALABAMA). These improvements are applicable to single-particle laser ablation mass spectrometers in general. To characterize the modifications, extensive sizeresolved measurements with spherical polystyrene latex particles (PSL; 150-6000 nm) and cubic sodium chloride particles (NaCl; 400-1700 nm) were performed. Measurements at a fixed ALS position show an improved detectable particle size range of the new ALS compared to the previously used Liu-type ALS, especially for supermicron particles. At a lens pressure of 2.4 hPa, the new ALS achieves a PSL particle size range from 230 to 3240 nm with 50% detection efficiency and between 350 and 2000 nm with 95% detection efficiency. The particle beam divergence was determined by measuring the detection efficiency at variable ALS positions along the laser cross sections and found to be minimal for PSL at about 800 nm. Compared to measurements by singleparticle mass spectrometry (SPMS) instruments using Liutype ALSs, the minimum particle beam divergence is shifted towards larger particle sizes. However, there are no disadvantages compared to the Liu-type lenses for particle sizes down to 200 nm. Improvements achieved by using the DIE and an additional electric shielding could be evaluated by size-resolved measurements of the hit rate, which is the ratio of laser pulses yielding a detectable amount of ions to the total number of emitted laser pulses. In particular, the hit rate for multiply charged particles smaller than 500 nm is significantly improved by preventing an undesired deflection of these particles in the ion extraction field. Moreover, it was found that by using the DIE the ion yield of the ablation, ionization, and ion extraction process could be increased, resulting in up to 7 times higher signal intensities of the cation spectra. The enhanced ion yield results in a larger effective width of the ablation laser beam, which in turn leads to a hit rate of almost 100% for PSL particles in the size range from 350 to 2000 nm. Regarding cubic NaCl particles the modifications of the ALABAMA result in an up to 2 times increased detection efficiency and an up to 5 times increased hit rate. The need for such instrument modifications arises in particular for measurements of particles that are present in low number concentrations such as ice-nucleating particles (INPs) in general, but also aerosol particles at high altitudes or in pristine environments. Especially for these low particle number concentrations, improved efficiencies help to overcome the statistical limitations of single-particle mass spectrometer measurements. As an example, laboratory INP measurements carried out in this study show that the appli- cation of the DIE alone increases the number of INP mass spectra per time unit by a factor of 2 to 3 for the sampled substances. Overall, the combination of instrument modifications presented here resulted in an increased measurement efficiency of the ALABAMA for different particle types and particles shape as well as for highly charged particles. © 2020 Copernicus GmbH. All rights reserved
Detoxifying Escherichia coli for endotoxin-free production of recombinant proteins
Es va publicar un treball amb esmenes a aquest article que es pot consultar a https://ddd.uab.cat/record/185349 (DOI 10.1186/s12934-015-0265-x)Background: lipopolysaccharide (LPS), also referred to as endotoxin, is the major constituent of the outer leaflet of the outer membrane of virtually all Gram-negative bacteria. The lipid A moiety, which anchors the LPS molecule to the outer membrane, acts as a potent agonist for Toll-like receptor 4/myeloid differentiation factor 2-mediated pro-inflammatory activity in mammals and, thus, represents the endotoxic principle of LPS. Recombinant proteins, commonly manufactured in Escherichia coli, are generally contaminated with endotoxin. Removal of bacterial endotoxin from recombinant therapeutic proteins is a challenging and expensive process that has been necessary to ensure the safety of the final product. -Results: as an alternative strategy for common endotoxin removal methods, we have developed a series of E. coli strains that are able to grow and express recombinant proteins with the endotoxin precursor lipid IVA as the only LPS-related molecule in their outer membranes. Lipid IVA does not trigger an endotoxic response in humans typical of bacterial LPS chemotypes. Hence the engineered cells themselves, and the purified proteins expressed within these cells display extremely low endotoxin levels. - Conclusions: this paper describes the preparation and characterization of endotoxin-free E. coli strains, and demonstrates the direct production of recombinant proteins with negligible endotoxin contamination
MTBseq: a comprehensive pipeline for whole genome sequence analysis of Mycobacterium tuberculosis complex isolates
Analyzing whole-genome sequencing data of Mycobacterium tuberculosis complex (MTBC) isolates in a standardized workflow enables both comprehensive antibiotic resistance profiling and outbreak surveillance with highest resolution up to the identification of recent transmission chains. Here, we present MTBseq, a bioinformatics pipeline for next-generation genome sequence data analysis of MTBC isolates. Employing a reference mapping based workflow, MTBseq reports detected variant positions annotated with known association to antibiotic resistance and performs a lineage classification based on phylogenetic single nucleotide polymorphisms (SNPs). When comparing multiple datasets, MTBseq provides a joint list of variants and a FASTA alignment of SNP positions for use in phylogenomic analysis, and identifies groups of related isolates. The pipeline is customizable, expandable and can be used on a desktop computer or laptop without any internet connection, ensuring mobile usage and data security. MTBseq and accompanying documentation is available from https://github.com/ngs-fzb/MTBseq_source
Gelungene Versöhnung - unsichere Zukunft? Zur Raison d'ĂȘtre der deutsch-französischen Beziehungen in der neuen EuropĂ€ischen Union
"Die Frage nach der Notwendigkeit und LegitimitĂ€t der deutsch-französischen Sonderbeziehung im Europa der 25 stellt sich nach der Ablehnung der EuropĂ€ischen Verfassung in Frankreich und den Niederlanden sowie dem vorlĂ€ufigen Scheitern der EU-Finanzverhandlungen umso dringlicher. Mit der Rolle und Perzeption der deutsch-französischen Zusammenarbeit in der erweiterten EuropĂ€ischen Union setzte sich im Juni ein internationales Kolloquium mit dem Titel 'Gelungene Versöhnung â unsichere Zukunft?' in Erinnerung an Joseph Rovan auseinander, dessen Tagungsergebnisse das Dossier dokumentiert. Neben BeitrĂ€gen zur Bewertung der aktuellen Krise und den Herausforderungen an Deutschland und Frankreich, analysieren (weitere BeitrĂ€ge) den Blick der anderen Mitgliedstaaten auf das 'couple'." (Autorenreferat
Phylogenomic Perspective on a Unique Mycobacterium bovis Clade Dominating Bovine Tuberculosis Infections among Cattle and Buffalos in Northern Brazil.
Lack of routine surveillance in countries endemic for bovine tuberculosis (TB) and limited laboratory support contributes to the inability to differentiate the Mycobacterium tuberculosis Complex species, leading to an underestimated burden of the disease. Here, Whole-Genome Sequencing of Mycobacterium bovis isolated from tissues with TB-like lesions obtained from cattle and buffalos at MarajĂł Island, Brazil, demonstrates that recent transmission of M. bovis is ongoing at distinct sites. Moreover, the M. bovis epidemiology in this setting is herein found to be dominated by an endemic and unique clade composed of strains evolved from a common ancestor that are now genetically differentiated from other M. bovis clades. Additionally, envisioning a rapid strain differentiation and tracing across multiple settings, 28 globally validated strain-specific SNPs were identified, three of which considered as robust markers for the M. bovis MarajĂł strain. In conclusion, this study contributes with data regarding the identification of a novel M. bovis phylogenetic clade responsible for ongoing transmission events in both cattle and buffalo species in Brazil, provides a framework to investigate the dissemination of this highly prevalent strain and, holds the potential to inform TB control strategies that may help to prevent the spread of bovine and zoonotic TB
Compensatory evolution drives multidrug-resistant tuberculosis in Central Asia
Bacterial factors favoring the unprecedented multidrug-resistant tuberculosis (MDR-TB) epidemic in the former Soviet Union remain unclear. We utilized whole genome sequencing and Bayesian statistics to analyze the evolutionary history, temporal emergence of resistance and transmission networks of MDR; Mycobacterium tuberculosis; complex isolates from Karakalpakstan, Uzbekistan (2001-2006). One clade (termed Central Asian outbreak, CAO) dating back to 1974 (95% HPD 1969-1982) subsequently acquired resistance mediating mutations to eight anti-TB drugs. Introduction of standardized WHO-endorsed directly observed treatment, short-course in Karakalpakstan in 1998 likely selected for CAO-strains, comprising 75% of sampled MDR-TB isolates in 2005/2006. CAO-isolates were also identified in a published cohort from Russia (2008-2010). Similarly, the presence of mutations supposed to compensate bacterial fitness deficits was associated with transmission success and higher drug resistance rates. The genetic make-up of these MDR-strains threatens the success of both empirical and standardized MDR-TB therapies, including the newly WHO-endorsed short MDR-TB regimen in Uzbekistan
Untersuchung und EindÀmmung eines SARS-CoV-2-Alpha-Ausbruchs in einer Pflegeeinrichtung im Landkreis Dithmarschen, Juni 2021
Bewohnende und Personal in Pflegeeinrichtungen gehören zu den Personengruppen, die ab dem 27.12.2020 in Deutschland priorisiert die COVID-19-Impfung erhielten. Diese zeigte eine gute Wirksamkeit hinsichtlich des Schutzes vor Infektionen mit der Alpha-Variante und eine sehr hohe Wirksamkeit vor schweren KrankheitsverlĂ€ufen. In einer Pflegeeinrichtung im Landkreis Dithmarschen kam es zwischen dem 01.04. und 23.06.2021 dennoch zu einem SARS-CoV-2-Ausbruch, bei dem eine hohe Anzahl vollstĂ€ndig geimpfter Personen infiziert wurde und teilweise schwer erkrankte oder verstarb. Beschrieben werden zum einen die Methoden, die bei der Ausbruchsuntersuchung im Pflegeheim angewandt wurden, und zum anderen die MaĂnahmen, die schlussendlich zur AusbruchseindĂ€mmung beitrugen.Peer Reviewe
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