838 research outputs found

    Evidence of global-scale aeolian dispersal and endemism in isolated geothermal microbial communities of Antarctica

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    New evidence in aerobiology challenges the assumption that geographical isolation is an effective barrier to microbial transport. However, given the uncertainty with which aerobiological organisms are recruited into existing communities, the ultimate impact of microbial dispersal is difficult to assess. To evaluate the ecological significance of global-scale microbial dispersal, molecular genetic approaches were used to examine microbial communities inhabiting fumarolic soils on Mt. Erebus, the southernmost geothermal site on Earth. There, hot, fumarolic soils provide an effective environmental filter to test the viability of organisms that have been distributed via aeolian transport over geological time. We find that cosmopolitan thermophiles dominate the surface, whereas endemic Archaea and members of poorly understood Bacterial candidate divisions dominate the immediate subsurface. These results imply that aeolian processes readily disperse viable organisms globally, where they are incorporated into pre-existing complex communities of endemic and cosmopolitan taxa

    Benthic microbial communities of coastal terrestrial and ice shelf Antarctic meltwater ponds.

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    The numerous perennial meltwater ponds distributed throughout Antarctica represent diverse and productive ecosystems central to the ecological functioning of the surrounding ultra oligotrophic environment. The dominant taxa in the pond benthic communities have been well described however, little is known regarding their regional dispersal and local drivers to community structure. The benthic microbial communities of 12 meltwater ponds in the McMurdo Sound of Antarctica were investigated to examine variation between pond microbial communities and their biogeography. Geochemically comparable but geomorphologically distinct ponds were selected from Bratina Island (ice shelf) and Miers Valley (terrestrial) (<40 km between study sites), and community structure within ponds was compared using DNA fingerprinting and pyrosequencing of 16S rRNA gene amplicons. More than 85% of total sequence reads were shared between pooled benthic communities at different locations (OTU0.05), which in combination with favorable prevailing winds suggests aeolian regional distribution. Consistent with previous findings Proteobacteria and Bacteroidetes were the dominant phyla representing over 50% of total sequences; however, a large number of other phyla (21) were also detected in this ecosystem. Although dominant Bacteria were ubiquitous between ponds, site and local selection resulted in heterogeneous community structures and with more than 45% of diversity being pond specific. Potassium was identified as the most significant contributing factor to the cosmopolitan community structure and aluminum to the location unique community based on a BEST analysis (Spearman's correlation coefficient of 0.632 and 0.806, respectively). These results indicate that the microbial communities in meltwater ponds are easily dispersed regionally and that the local geochemical environment drives the ponds community structure

    Influence of soil properties on archaeal diversity and distribution in the McMurdo Dry Valleys, Antarctica

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    Archaea are the least understood members of the microbial community in Antarctic mineral soils. Although their occurrence in Antarctic coastal soils has been previously documented, little is known about their distribution in soils across the McMurdo Dry Valleys, Victoria Land. In this study, terminal-restriction fragment length polymorphism (t-RFLP) analysis and 454 pyrosequencing were coupled with a detailed analysis of soil physicochemical properties to characterize archaeal diversity and identify environmental factors that might shape and maintain archaeal communities in soils of the three southern most McMurdo Dry Valleys (Garwood, Marshall, and Miers Valley). Archaea were successfully detected in all inland and coastal mineral soils tested, revealing a low overall richness (mean of six operational taxonomic units [OTUs] per sample site). However, OTU richness was higher in some soils and this higher richness was positively correlated with soil water content, indicating water as a main driver of archaeal community richness. In total, 18 archaeal OTUs were detected, predominately Thaumarchaeota affiliated with Marine Group 1.1b (> 80% of all archaeal sequences recovered). Less abundant OTUs (2% of all archaeal sequences) were loosely related to members of the phylum Euryarchaeota. This is the first comprehensive study showing a widespread presence and distribution of Archaea in inland Antarctic soils

    Groundtruthing next-gen sequencing for microbial ecology-biases and errors in community structure estimates from PCR amplicon pyrosequencing

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    Analysis of microbial communities by high-throughput pyrosequencing of SSU rRNA gene PCR amplicons has transformed microbial ecology research and led to the observation that many communities contain a diverse assortment of rare taxa-a phenomenon termed the Rare Biosphere. Multiple studies have investigated the effect of pyrosequencing read quality on operational taxonomic unit (OTU) richness for contrived communities, yet there is limited information on the fidelity of community structure estimates obtained through this approach. Given that PCR biases are widely recognized, and further unknown biases may arise from the sequencing process itself, a priori assumptions about the neutrality of the data generation process are at best unvalidated. Furthermore, post-sequencing quality control algorithms have not been explicitly evaluated for the accuracy of recovered representative sequences and its impact on downstream analyses, reducing useful discussion on pyrosequencing reads to their diversity and abundances. Here we report on community structures and sequences recovered for in vitro-simulated communities consisting of twenty 16S rRNA gene clones tiered at known proportions. PCR amplicon libraries of the V3-V4 and V6 hypervariable regions from the in vitro-simulated communities were sequenced using the Roche 454 GS FLX Titanium platform. Commonly used quality control protocols resulted in the formation of OTUs with >1% abundance composed entirely of erroneous sequences, while over-aggressive clustering approaches obfuscated real, expected OTUs. The pyrosequencing process itself did not appear to impose significant biases on overall community structure estimates, although the detection limit for rare taxa may be affected by PCR amplicon size and quality control approach employed. Meanwhile, PCR biases associated with the initial amplicon generation may impose greater distortions in the observed community structure

    Design Concepts for Automating Maintenance Instructions

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    This research task was performed under the Technology for Readiness and Sustainment (TRS) contract (F33615-99-D-6001) for the Air Force Research Laboratory (AFRL), Sustainment Logistics Branch (HESS) at Wright-Patterson AFB, OH. The period of performance spanned one year starting 29 January 1999. The objective of this task was to develop and demonstrate a framework that can support the automated validation and verification of aircraft maintenance Technical Orders (TOs). The research team examined all stages ofTO generation to determine which tasks most warranted further research. From that investigation, validation and verification of appropriate, safe, and correct procedure steps emerged as the primary research target. This process would be based on available computer-aided design (CAD) data, procedure step ordering from existing sources, and human models. This determination was based on which tasks could yield the greatest impact on the authoring process and offer the greatest potential economic benefits. The team then developed a research roadmap and outlined specific technologies to be addressed in possible subsequent Air Force research tasks. To focus on the potential technology integration of the validation and verification component into existing or future TO generation procedures, we defined a demonstration scenario. Using the Front Uplock Hook assembly from an F/A-18 as the subject, we examined task procedure steps and failures that could be exposed by automated validation tools. These included hazards to personnel, damage to equipment, and incorrect disassembly order. Using the Parameterized Action Representation (PAR) developed on previous projects for actions and equipment behaviors, we characterized procedure steps and their positive and negative consequences. Finally, we illustrated a hypothetical user interface extension to a typical Interactive Electronic Technical Manual (IETM) authoring system to demonstrate how this process might appear to the TO author

    Critical Issues for Psychiatric Medication Shared Decision Making With Youth and Families

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    This is the publisher's version, also found here: http://doi.org/10.1606/1044-3894.4135The primary aims of this article are to describe the current context for youth shared decision making (SDM) within the U.S. children’s mental health system and to identify important considerations for the development of this approach as a research and service domain. The notion is substantiated in the literature that participation in treatment decisions can prepare youth for making their own decisions as adults, can be therapeutic, and can have positive effects on their self-confidence and self-esteem. Still, the complex youth–family–provider dynamic raises important issues that need to be addressed before SDM can be successfully implemented

    The global impact of Aspergillus infection on COPD

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    From Springer Nature via Jisc Publications RouterHistory: received 2020-07-15, registration 2020-08-05, accepted 2020-08-05, pub-electronic 2020-09-11, online 2020-09-11, collection 2020-12Publication status: PublishedFunder: Manchester Biomedical Research Centre; doi: http://dx.doi.org/10.13039/100014653Abstract: Background: Advanced chronic obstructive pulmonary disease (COPD) often leads to hospitalisation and invasive aspergillosis (IA) is a serious complication. Aspergillus sensitisation may worsen symptoms in COPD. Methods: We identified published papers between January 2000 and May 2019 with > 50 subjects and GOLD criteria for grade II, III or IV (FEV1/FVC 0.05). Conclusions: The prevalence of COPD is much higher than previously estimated. Overall COPD mortality may be higher than estimated and IA probably contributes to many deaths. Improved rapid diagnosis of IA using culture and non-culture based techniques is required in COPD hospital admissions to reduce mortality

    Methods for Linking Community Views to Measureable Outcomes in a Youth Violence Prevention Program

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    Background: All parties in community–academic partnerships have a vested interest prevention program success. Markers of success that reflect community’s experiences of programmatic prevention success are not always measurable, but critically speak to community-defined needs. Objective: The purpose of this manuscript was to (1) describe our systematic process for linking locally relevant community views (community-defined indicators) to measurable outcomes in the context of a youth violence prevention program and (2) discuss lessons learned, next steps, and recommendations for others trying to replicate a similar process. Methods: A research team composed of both academic and community researchers conducted a systematic process of matching community-defined indicators of youth violence prevention programmatic success to standardized youth survey items being administered in the course of a program evaluation. The research team of three community partners and five academic partners considered 43 community-defined indicators and 208 items from the youth surveys being utilized within the context of a community-based aggression prevention program. At the end of the matching process, 92 youth survey items were identified and agreed upon as potential matches to 11 of the community-defined indicators. Conclusions: We applied rigorous action steps to match community-defined indicators to survey data collected in the youth violence prevention intervention. We learned important lessons that inform recommendations for others interested in such endeavors. The process used to derive and assess community-defined indicators of success emphasized the principles of community-based participatory research (CBPR) and use of existing and available data to reduce participant burden
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