17 research outputs found

    SiaA/D interconnects c-di-GMP and RsmA signaling to coordinate cellular aggregation of Pseudomonas aeruginosa in response to environmental conditions

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    © 2016 Colley, Dederer, Carnell, Kjelleberg, Rice and Klebensberger. Pseudomonas aeruginosa has emerged as an important opportunistic human pathogen that is often highly resistant to eradication strategies, mediated in part by the formation of multicellular aggregates. Cellular aggregates may occur attached to a surface (biofilm), at the air-liquid interface (pellicle), or as suspended aggregates. Compared to surface attached communities, knowledge about the regulatory processes involved in the formation of suspended cell aggregates is still limited. We have recently described the SiaA/D signal transduction module that regulates macroscopic cell aggregation during growth with, or in the presence of the surfactant SDS. Targets for SiaA/D mediated regulation include the Psl polysaccharide, the CdrAB two-partner secretion system and the CupA fimbriae. While the global regulators c-di-GMP and RsmA are known to inversely coordinate cell aggregation and regulate the expression of several adhesins, their potential impact on the expression of the cupA operon remains unknown. Here, we investigated the function of SiaA (a putative ser/thr phosphatase) and SiaD (a di-guanylate cyclase) in cupA1 expression using transcriptional reporter fusions and qRT-PCR. These studies revealed a novel interaction between the RsmA posttranscriptional regulatory system and SiaA/D mediated macroscopic aggregation. The RsmA/rsmY/Z system was found to affect macroscopic aggregate formation in the presence of surfactant by impacting the stability of the cupA1 mRNA transcript and we reveal that RsmA directly binds to the cupA1 leader sequence in vitro. We further identified that transcription of the RsmA antagonist rsmZ is controlled in a SiaA/D dependent manner during growth with SDS. Finally, we found that the siaD transcript is also under regulatory control of RsmA and that overproduction of RsmA or the deletion of siaD results in decreased cellular cyclic di-guanosine monophosphate (c-di-GMP) levels quantified by a transcriptional reporter, demonstrating that SiaA/D connects c-di-GMP and RsmA/rsmY/Z signaling to reciprocally regulate cell aggregation in response to environmental conditions

    The impact of in-service professional development on the quality of teacher-child interactions in early education and care: A meta-analysis

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    High-quality interactions between young children and teachers in early childhood education and care (ECEC) are the cornerstone of educational quality. International findings suggest that the quality of interactions that support emotions and classroom organization is at a medium to high level, but the quality of instructional support is at a lower level. Within the “Teaching Through Interactions” framework developed by Hamre and colleagues (2013), several efforts were made to evaluate and improve key teacher-child interactions through in-service training. Our review includes experimental studies that evaluate professional development using the Classroom Assessment Scoring System measures. The systematic literature search and coding of studies was carried out by two independent reviewers. Our review includes 15 recent studies with 18 treatments. The meta-analysis (random effect model) showed an overall statistically significant professional development effect of g = 0.39 (SE = .08), i.e. close to a medium-size effect. In addition, effect sizes were almost equal for interactions related to emotional support, classroom organization, and instructional support (g= 0.35, 0.30, and 0.43, respectively). The quality of experimental studies and professional development was at a high level (e.g., individual component, feedback, or modeling) and experimental findings were generally positive. Our meta-analysis indicates that high-quality in-service programs have the strength to improve teacher-child interactions and pedagogical quality across all three domains

    Über die Inhaltsstoffe des grĂŒnen KnollenblĂ€tterpilzes, LIX. Die Raumstruktur der Phallotoxine

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    Die ThioetherbrĂŒcke [CH2 ‐ S ‐ C(α‐indol)] in den Phallotoxinen ist ein inhĂ€rent dissymmetrischer Chromophor, der die positiven Cottoneffekte um 290 nm im CD‐Spektrum verursacht. Bei einer frĂŒheren Strukturanalyse durch 1H‐NMR konnte die M‐ oder P‐HelizitĂ€t dieses Strukturelements nicht eindeutig bestimmt werden. Das einfacher gebaute cyclische Thioethertripeptid 2‐Mercapto‐L‐tryptophylglycylcystein‐cyclosulfid (1 → 3) (2a) weist im CD‐Spektrum um 290 nm zu denen der Phallotoxine genau spiegelbildliche negative Cottoneffekte (Abb. 1) auf. Die Strukturanalyse von 2a durch 1H‐NMR (360 MHz) fĂŒhrte zu einem Strukturvorschlag mit M‐HelizitĂ€t. Das N‐p‐Brombenzolsulfonylderivat 2c mit analogem CD‐Spektrum bildete mit Aceton Kristalle, die zur Röntgenstrukturanalyse geeignet waren. Die dadurch erhaltene Raumformel zeigt fĂŒr das fragliche Strukturelement negative M‐HelizitĂ€t. Demnach enthalten die Phallotoxine den spiegelbildlich analogen Chromophor mit positiver P‐HelizitĂ€t. Die EinfĂŒhrung eines weiteren chiralen Zentrums in den Peptidring (2b: L‐Alanin statt Glycin in 2a) hat auf die Gestalt des CD‐Spektrums keinen Einfluß
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