113 research outputs found
Partnering to Enhance Education and Public Engagement Programs
Collaborating with partners is a fundamental aspect of the Lunar and Planetary Institute's (LPI) educational and public engagement efforts. Such partnerships enable scientists and educators to include members of the audience in program planning and execution. Ultimately, partnerships strengthen programs by providing diverse resources, expertise, and expanding the potential audience
Testing the inverse-square law of gravity on a 465-m tower
We have performed a test of Newton’s universal theory of gravitation by comparing gravity measured on a tower to an upward continuation of the surface gravity field. We measured gravity at 12 heights on a 465-m tower at the Nevada Test Site and, in addition, made measurements at 281 locations on the ground. The surface points fell within 91 optimally chosen sectors that extended out to 2.6 km from the tower. These data were combined with 60000 additional surface gravity measurements within 300 km of the tower. We used a surface integral derived from Laplace’s equation to upward continue the surface gravity field and our observations are consistent with the Newtonian predictions to within (-60±95)×10^-8 m sec^-2 at the top of the tower
Biological Characterisation of Haliclona (?gellius) sp.: Sponge and Associated Microorganisms
We have characterised the northern Pacific undescribed sponge Haliclona (?gellius) sp. based on rDNA of the sponge and its associated microorganisms. The sponge is closely related to Amphimedon queenslandica from the Great Barrier Reef as the near-complete 18S rDNA sequences of both sponges were identical. The microbial fingerprint of three specimens harvested at different times and of a transplanted specimen was compared to identify stably associated microorganisms. Most bacterial phyla were detected in each sample, but only a few bacterial species were determined to be stably associated with the sponge. A sponge-specific β- and γ-Proteobacterium were abundant clones and both of them were present in three of the four specimens analysed. In addition, a Planctomycete and a Crenarchaea were detected in all sponge individuals. Both were closely related to operational taxonomic units that have been found in other sponges, but not exclusively in sponges. Interestingly, also a number of clones that are closely related to intracellular symbionts from insects and amoeba were detected
Bacterial Communities Involved in Soil Formation and PlantEstablishment Triggered by Pyrite Bioweathering on ArcticMoraines
Abstract In arctic glacier moraines, bioweathering primed
by microbial iron oxidizers creates fertility gradients that
accelerate soil development and plant establishment. With
the aim of investigating the change of bacterial diversity in
a pyrite-weathered gradient, we analyzed the composition
of the bacterial communities involved in the process by
sequencing 16S rRNA gene libraries from different biological
soil crusts (BSC). Bacterial communities in three BSC
of different morphology, located within 1 m distance
downstream a pyritic conglomerate rock, were significantly
diverse. The glacier moraine surrounding the weathered site
showed wide phylogenetic diversity and high evenness with
15 represented bacterial classes, dominated by Alphaproteobacteria
and pioneer Cyanobacteria colonizers. The bioweathered
area showed the lowest diversity indexes and only nine
bacterial families, largely dominated by Acidobacteriaceae
and Acetobacteraceae typical of acidic environments, in
accordance with the low pH of the BSC. In the weathered
BSC, iron-oxidizing bacteria were cultivated, with counts
decreasing along with the increase of distance from the rock,
and nutrient release from the rock was revealed by
environmental scanning electron microscopy-energy dispersive
X-ray analyses. The vegetated area showed the presence
of Actinomycetales, Verrucomicrobiales, Gemmatimonadales,
Burkholderiales, and Rhizobiales, denoting a bacterial
community typical of developed soils and indicating that the
lithoid substrate of the bare moraine was here subjected to an
accelerated colonization, driven by iron-oxidizing activity
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