Quorum Sensing Signal Production and Microbial Interactions in a Polymicrobial Disease of Corals and the Coral Surface Mucopolysaccharide Layer

Black band disease (BBD) of corals is a complex polymicrobial disease considered to be a threat to coral reef health, as it can lead to mortality of massive reef-building corals. The BBD community is dominated by gliding, filamentous cyanobacteria with a highly diverse population of heterotrophic bacteria. Microbial interactions such as quorum sensing (QS) and antimicrobial production may be involved in BBD disease pathogenesis. In this study, BBD (whole community) samples, as well as 199 bacterial isolates from BBD, the surface mucopolysaccharide layer (SML) of apparently healthy corals, and SML of apparently healthy areas of BBD-infected corals were screened for the production of acyl homoserine lactones (AHLs) and for autoinducer-2 (AI-2) activity using three bacterial reporter strains. AHLs were detected in all BBD (intact community) samples tested and in cultures of 5.5% of BBD bacterial isolates. Over half of a subset (153) of the isolates were positive for AI-2 activity. AHL-producing isolates were further analyzed using LC-MS/MS to determine AHL chemical structure and the concentration of (S)-4,5-dihydroxy-2,3-pentanedione (DPD), the biosynthetic precursor of AI-2. C6-HSL was the most common AHL variant detected, followed by 3OC4-HSL. In addition to QS assays, 342 growth challenges were conducted among a subset of the isolates, with 27% of isolates eliciting growth inhibition and 2% growth stimulation. 24% of BBD isolates elicited growth inhibition as compared to 26% and 32% of the bacteria from the two SML sources. With one exception, only isolates that exhibited AI-2 activity or produced DPD inhibited growth of test strains. These findings demonstrate for the first time that AHLs are present in an active coral disease. It is possible that AI-2 production among BBD and coral SML bacteria may structure the microbial communities of both a polymicrobial infection and the healthy coral microbiome

Partnerships and Public Service: Normative Issues for Journalists in Converged Newsrooms

As media companies test and implement newsroom “convergence,” growing numbers of journalists are producing content not only for their own employer but also for other media outlets with which that employer has a business relationship. This article, based on case studies in four converged news markets, explores journalists’ perceptions of normative pressures in this new media environment, particularly in relation to the overarching concept of public service. The findings suggest that although journalists do not see convergence itself as posing significant ethical problems, they do raise concerns related to specific components of public service, including a devotion to accuracy, an avoidance of sensationalism, and independence from economic pressures

eLine10k: A high dynamic range front-end ASIC for LCLS detectors

Abstract Not Provide

Mixing in Circular and Non-circular Jets in Crossflow

Coherent structures and mixing in the flow field of a jet in crossflow have been studied using computational (large eddy simulation) and experimental (particle image velocimetry and laser-induced fluorescence) techniques. The mean scalar fields and turbulence statistics as determined by both are compared for circular, elliptic, and square nozzles. For the latter configurations, effects of orientation are considered. The computations reveal that the distribution of a passive scalar in a cross-sectional plane can be single- or double-peaked, depending on the nozzle shape and orientation. A proper orthogonal decomposition of the transverse velocity indicates that coherent structures may be responsible for this phenomenon. Nozzles which have a single-peaked distribution have stronger modes in transverse direction. The global mixing performance is superior for these nozzle types. This is the case for the blunt square nozzle and for the elliptic nozzle with high aspect ratio. It is further demonstrated that the flow field contains large regions in which a passive scalar is transported up the mean gradient (counter-gradient transport) which implies failure of the gradient diffusion hypothesis

Recruitment, use, and satisfaction with a web platform supporting families of children with suspected or diagnosed developmental coordination disorder: A randomized feasibility trial

Objectives. To determine the feasibility of recruiting families of children with suspected or diagnosed developmental coordination disorder (sdDCD) and explore their satisfaction with a web-based intervention Design. A feasibility randomized trial was conducted. Participants were the parents of 5-12-year-old children with sdDCD. The intervention group had access to online resources, group and private forums, and videoconferencing with a therapist. Main outcomes were recruitement and retention rates. Satisfaction was documented through a post-intervention survey and interview. Results. The recruitment rate was seven participants per month (n = 28 participants) and retention rate was 68%. Satisfaction was moderate. No differences in use and satisfaction were observed between groups. Participants formulated recommendations for improving the intervention, including targeting families earlier in the diagnosis process, and pre-scheduling meetings with therapists. Conclusions. This study demonstrated the feasibility of future trials, and highlighted avenues for improvement. Parent involvement during the development of the intervention is discussed at length. Abbreviations: DCD: Developmental Coordination Disorder; sdDCD: suspected or diagnosed Developmental Coordination Disorder; RCT: randomized-controled trial