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

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

Characterisation of bacterioplankton communities in the meltwater ponds of Bratina Island, Victoria Land, Antarctica

A unique collection of Antarctic aquatic environments (meltwater ponds) lies in close proximity on the rock and sediment-covered undulating surface of the McMurdo Ice Shelf, near Bratina Island (Victoria Land, Antarctica). During the 2009–10 mid-austral summer, sets of discrete water samples were collected across the vertical geochemical gradients of five meltwater ponds (Egg, P70E, Legin, Salt and Orange) for geochemical and microbial community structure analysis. Bacterial DNA fingerprints (using Automated Ribosomal Intergenic Spacer Analysis) statistically clustered communities within ponds based on ANOSIM (R = 0.766, P = 0.001); however, one highly stratified pond (Egg) had two distinct depth-related bacterial communities (R = 0.975, P = 0.008). 454 pyrosequencing at three depths within Egg also identified phylum level shifts and increased diversity with depth, Bacteroidetes being the dominant phyla in the surface sample and Proteobacteria being dominant in the bottom two depths. BEST analysis, which attempts to link community structure and the geochemistry of a pond, identified conductivity and pH individually, and to a lesser extent Ag109, NO2 and V51 as dominant influences to the microbial community structure in these ponds. Increasing abundances of major halo-tolerant OTUs across the strong conductivity gradient reinforce it as the primary driver of community structure in this stud

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

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

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

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

Visual Fixation Durations and Saccade Amplitudes: Shifting Relationship in a Variety of Conditions

Is there any relationship between visual fixation durations and saccade amplitudes in free exploration of pictures and scenes? In four experiments with naturalistic stimuli, we compared eye movements during early and late phases of scene perception. Influences of repeated presentation of similar stimuli (Experiment 1), object density (Experiment 2), emotional stimuli (Experiment 3) and mood induction (Experiment 4) were examined. The results demonstrate a systematic increase in the durations of fixations and a decrease for saccadic amplitudes over the time course of scene perception. This relationship was very stable across the variety of studied conditions. It can be interpreted in terms of a shifting balance of the two modes of visual information processing

Exploring School Staff Perceptions Relating to animals and their involvement in interventions to Support Mental Health

Given the growing awareness of the health benefits of human-animal interactions, the use of animal-assisted interventions (AAIs) in educational settings has increased over the years. While many school districts are now considering or utilizing AAIs, the literature investigating AAI-related perceptions among school stakeholders is limited with previous studies focusing on evaluating specific programs. to address this gap, a qualitative exploratory study was conducted using semi-structured interviews with school staff in the San Antonio, TX community. A total of 11 interviews were completed with staff serving preschool and elementary school age children. Data collected from interviews were analyzed using thematic analysis. Findings demonstrated that participating staff had some knowledge of the potential benefits of human-animal interactions and perceived the involvement of animals in interventions to be beneficial to children\u27s emotions and social-emotional skills. While perceptions of AAIs were generally positive, concerns around children\u27s safety and well-being were expressed as potential barriers in the adoption of AAIs in schools. These findings are preliminary and provide a segue to future research that can help expand our understanding of how school staff perceive AAIs, their impact on children\u27s mental health, their compatibility with school values, and their advantage relative to other interventions

School Parent attitudes and Perceptions Relating to animals, animal-Assisted interventions, and the Support of Children\u27s Mental Health

Growing awareness of the negative effects of trauma has led San Antonio, TX, school districts to expand efforts that can help mitigate these effects and support mental health. Given the literature around the psychological benefits of human-animal interactions, the concept of incorporating animals in treatments or interventions is not a new one. While schools have begun considering or utilizing animal-assisted interventions (AAIs), there have been limited efforts to understand existing perceptions relating to animals and AAIs among school parents in this Hispanic community. to address this gap, a cross-sectional study consisting of a 34-item survey was conducted to explore attitudes, knowledge, and perceptions relating to animals (i.e., pets), AAIs, and the need for supporting young children\u27s mental health among parents. A total of 187 surveys from two school districts were completed and utilized for analysis. The study\u27s findings demonstrate that parents acknowledged the importance of addressing mental health issues early on and were aware of the health benefits human-animal interactions can provide. Furthermore, parents had positive attitudes toward pets and positive perceptions toward AAIs in schools. Some implementation concerns were expressed relating to safety and well-being. Overall, these findings suggest there is existing parent support in using AAIs as a trauma-informed strategy and school innovation

Musculoskeletal injuries in Us air Force Security Forces, January 2009 to December 2018

OBJECTIVE: to determine the incidence, types, and risk factors of musculoskeletal injuries in a military security forces population. METHODS: Demographic and diagnostic data were retrieved on enlisted US Air Force security forces personnel who served on active duty between January 2009 and December 2018. Incidence rates and ratios were calculated using Poisson regression. RESULTS: During 251,787 person-years of exposure, 62,489 personnel served on active duty. Of these, 40,771 (65.2%) were diagnosed with at least one musculoskeletal injury. The majority (60.1%) of the 164,078 unique musculoskeletal injuries were inflammation and pain secondary to overuse. After adjusting for other factors, women had a 31% higher injury rate than men, and those who were overweight and obese had 15% and 30% higher rates, respectively, than normal-weight peers. CONCLUSIONS: Modifiable and non-modifiable factors contribute to musculoskeletal injuries in the security forces career field