43 research outputs found
Size-fractionated microbiome structure in subarctic rivers and a coastal plume across DOC and salinity gradients
Little is known about the microbial diversity of rivers that flow across the changing subarctic
landscape. Using amplicon sequencing (rRNA and rRNA genes) combined with HPLC
pigment analysis and physicochemical measurements, we investigated the diversity of
two size fractions of planktonic Bacteria, Archaea and microbial eukaryotes along
environmental gradients in the Great Whale River (GWR), Canada. This large subarctic
river drains an extensive watershed that includes areas of thawing permafrost, and
discharges into southeastern Hudson Bay as an extensive plume that gradually mixes
with the coastal marine waters. The microbial communities differed by size-fraction
(separated with a 3-μm filter), and clustered into three distinct environmental groups: (1)
the GWR sites throughout a 150-km sampling transect; (2) the GWR plume in Hudson
Bay; and (3) small rivers that flow through degraded permafrost landscapes. There was
a downstream increase in taxonomic richness along the GWR, suggesting that
sub-catchment inputs influence microbial community structure in the absence of sharp
environmental gradients. Microbial community structure shifted across the salinity gradient
within the plume, with changes in taxonomic composition and diversity. Rivers flowing
through degraded permafrost had distinct physicochemical and microbiome characteristics,
with allochthonous dissolved organic carbon explaining part of the variation in community
structure. Finally, our analyses of the core microbiome indicated that while a substantial
part of all communities consisted of generalists, most taxa had a more limited environmental
range and may therefore be sensitive to ongoing change
Development of Stitched Composite Structure for Advanced Aircraft
NASA has created the Environmentally Responsible Aviation Project to develop technologies which will reduce the impact of aviation on the environment. A critical aspect of this pursuit is the development of a lighter, more robust airframe that will enable the introduction of unconventional aircraft configurations. NASA and The Boeing Company are working together to develop a structural concept that is lightweight and an advancement beyond state-of-the-art composites. The Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) is an integrally stiffened panel design where elements are stitched together and designed to maintain residual load-carrying capabilities under a variety of damage scenarios. With the PRSEUS concept, through-the-thickness stitches are applied through dry fabric prior to resin infusion, and replace fasteners throughout each integral panel. Through-the-thickness reinforcement at discontinuities, such as along flange edges, has been shown to suppress delamination and turn cracks, which expands the design space and leads to lighter designs. The pultruded rod provides stiffening away from the more vulnerable skin surface and improves bending stiffness. A series of building blocks were evaluated to explore the fundamental assumptions related to the capability and advantages of PRSEUS panels. These building blocks addressed tension, compression, and pressure loading conditions. The emphasis of the development work has been to assess the loading capability, damage arrestment features, repairability, post-buckling behavior, and response of PRSEUS flat panels to out-of plane pressure loading. The results of this building-block program from coupons through an 80%-scale pressure box have demonstrated the viability of a PRSEUS center body for the Hybrid Wing Body (HWB) transport aircraft. This development program shows that the PRSEUS benefits are also applicable to traditional tube-andwing aircraft, those of advanced configurations, and other structures where weight and through-the-thickness strength are design considerations. An overview of the development of PRSEUS technology for commercial transport aircraft is the subject of this paper
Proceedings of the 3rd Biennial Conference of the Society for Implementation Research Collaboration (SIRC) 2015: advancing efficient methodologies through community partnerships and team science
It is well documented that the majority of adults, children and families in need of evidence-based behavioral health interventionsi do not receive them [1, 2] and that few robust empirically supported methods for implementing evidence-based practices (EBPs) exist. The Society for Implementation Research Collaboration (SIRC) represents a burgeoning effort to advance the innovation and rigor of implementation research and is uniquely focused on bringing together researchers and stakeholders committed to evaluating the implementation of complex evidence-based behavioral health interventions. Through its diverse activities and membership, SIRC aims to foster the promise of implementation research to better serve the behavioral health needs of the population by identifying rigorous, relevant, and efficient strategies that successfully transfer scientific evidence to clinical knowledge for use in real world settings [3]. SIRC began as a National Institute of Mental Health (NIMH)-funded conference series in 2010 (previously titled the “Seattle Implementation Research Conference”; $150,000 USD for 3 conferences in 2011, 2013, and 2015) with the recognition that there were multiple researchers and stakeholdersi working in parallel on innovative implementation science projects in behavioral health, but that formal channels for communicating and collaborating with one another were relatively unavailable. There was a significant need for a forum within which implementation researchers and stakeholders could learn from one another, refine approaches to science and practice, and develop an implementation research agenda using common measures, methods, and research principles to improve both the frequency and quality with which behavioral health treatment implementation is evaluated. SIRC’s membership growth is a testament to this identified need with more than 1000 members from 2011 to the present.ii SIRC’s primary objectives are to: (1) foster communication and collaboration across diverse groups, including implementation researchers, intermediariesi, as well as community stakeholders (SIRC uses the term “EBP champions” for these groups) – and to do so across multiple career levels (e.g., students, early career faculty, established investigators); and (2) enhance and disseminate rigorous measures and methodologies for implementing EBPs and evaluating EBP implementation efforts. These objectives are well aligned with Glasgow and colleagues’ [4] five core tenets deemed critical for advancing implementation science: collaboration, efficiency and speed, rigor and relevance, improved capacity, and cumulative knowledge. SIRC advances these objectives and tenets through in-person conferences, which bring together multidisciplinary implementation researchers and those implementing evidence-based behavioral health interventions in the community to share their work and create professional connections and collaborations
ERK5 is targeted to myocyte enhancer factor 2A (MEF2A) through a MAPK docking motif
One critical component in determining the specificity, and efficiency of MAPK (mitogen-activated protein kinase) substrate phophorylation is the presence of distinct docking domains in the substrate proteins. Docking domains have been shown to be important for the activities of members of the ERK (extracellular-signal-regulated kinase), JNK (c-Jun N-terminal kinase) and p38 subfamilies of MAPKs towards their substrates. Here, we demonstrate that docking domains also play an important role in ERK5-mediated substrate phosphorylation. The presence of a docking domain promotes both phosphorylation of myocyte enhancer factor, MEF2A, in vitro and its activation in vivo by ERK5. Mutational analysis of the MEF2A docking domain demonstrates that the specificity determinants for ERK5 are similar to those observed with members of the p38 subfamily. A docking domain recognized by ERK5 can direct ERK5 to activate heterologous substrates. Deletion analysis demonstrates that as with other MAPKs, it is the catalytic domain of ERK5 that recognizes the docking domain. Our data therefore extend previous observations on other MAPKs and demonstrate that the requirement for specific docking domains in promoting MAPK action towards substrates is a general property of MAPKs
Diversity and potential activity of methanotrophs in high methane-emitting permafrost thaw ponds
<div><p>Lakes and ponds derived from thawing permafrost are strong emitters of carbon dioxide and methane to the atmosphere, but little is known about the methane oxidation processes in these waters. Here we investigated the distribution and potential activity of aerobic methanotrophic bacteria in thaw ponds in two types of eroding permafrost landscapes in subarctic Québec: peatlands and mineral soils. We hypothesized that methanotrophic community composition and potential activity differ regionally as a function of the landscape type and permafrost degradation stage, and locally as a function of depth-dependent oxygen conditions. Our analysis of <i>pmoA</i> transcripts by Illumina amplicon sequencing and quantitative PCR showed that the communities were composed of diverse and potentially active lineages. Type I methanotrophs, particularly <i>Methylobacter</i>, dominated all communities, however there was a clear taxonomic separation between the two landscape types, consistent with environmental control of community structure. In contrast, methanotrophic potential activity, measured by <i>pmoA</i> transcript concentrations, did not vary with landscape type, but correlated with conductivity, phosphorus and total suspended solids. Methanotrophic potential activity was also detected in low-oxygen bottom waters, where it was inversely correlated with methane concentrations, suggesting methane depletion by methanotrophs. Methanotrophs were present and potentially active throughout the water column regardless of oxygen concentration, and may therefore be resilient to future mixing and oxygenation regimes in the warming subarctic.</p></div
Bray-Curtis dissimilarity cluster analysis of the methanotroph communities.
<p>Surface samples are represented by triangles and bottom samples by circles, either filled (small fraction) or open (large fraction). The heatmap shows the methanotroph community composition.</p
Concentrations of <i>pmoA</i> transcripts, methane and oxygen and methane in the sampled thaw ponds.
<p>Concentrations of <i>pmoA</i> transcripts, methane and oxygen and methane in the sampled thaw ponds.</p
Principal component analysis of the environmental variables.
<p>Temperature (T), dissolved oxygen (O2), pH, total phosphorus (TP), total suspended solid (TSS), conductivity (Cond), Chlorophyll <i>a</i> (Chla), total nitrogen (TN), methane (CH<sub>4</sub>), carbon dioxide (CO<sub>2</sub>) and dissolved organic carbon (DOC) are represented for the 9 sampled ponds. Colors distinguish the different valleys and the shapes distinguish surface (triangles) and bottom samples (circles).</p
The eastern Hudson Bay region around the villages of Kuujjuarapik and Umiujaq in subarctic Quebec, Canada.
<p>The locations of the four sampled valleys are shown with red (palsa) and blue (lithalsa) dots across the permafrost degradation gradient. Map created in R with the open-access databases "worldHires" <a href="https://www.evl.uic.edu/pape/data/WDB/" target="_blank">https://www.evl.uic.edu/pape/data/WDB/</a> and data from the Digital Chart of the World downloaded from DIVA-GIS (<a href="http://www.diva-gis.org" target="_blank">http://www.diva-gis.org</a>).</p