305 research outputs found
Diffusion bonding makes strong seal at flanged connector
Copper strip seals a high pressure fluid system connector so that it is insensitive to relaxation of the bolt loads. The copper strip is diffusion bonded to the surfaces of the connector flange by application of high pressure and temperature
Statistical Interface-leakage Analysis and Feasibility of Superfinished Surfaces for Sealing Final Report, Jan. 1964 - Mar. 1965. Design Criteria for Zero Leakage Connectors for Launch Vehicles
Extremely fine finished surfaces as mating parts for sealing in fluid connectors and statistical analysis of interface leakag
MassMine: Collecting and Archiving Big Data for Social Media Humanities Researchers
The MassMine project team representing participants from the Department of English, George A. Smathers Libraries (Libraries), and Research Computing at the University of Florida (UF) requests $60,000 to finish the version 1.0 release, develop a robust training program, and promote the MassMine open source software. MassMine enables researchers to collect their own social media data archives and supports data mining, thus providing free access to big data for academic inquiry. MassMine further supports researchers in creating and defining methods and measures for analyzing cultural and localized trends, and developing humanities research questions and data mining practices. The primary aims of this project are to: 1) refine the MassMine tools to support collection, acquisition, and use of available social media and web data; and, 2) develop a training program and corresponding online resources for supporting the broad use of MassMine by humanities researchers, regardless of experience
Design Criteria for Zero Leakage Connectors for Launch Vehicles. Mathematical Model of Interface Sealing Phenomenon, Volume 2 Final Report
Mathematical model of interface sealing phenomenon in determining design criteria for zero leakage connectors for launch vehicle
From Algae to Angiosperms – Inferring the Phylogeny of Green Plants ( Viridiplantae ) from 360 Plastid Genomes
Background
Next-generation sequencing has provided a wealth of plastid genome sequence data from an increasingly diverse set of green plants (Viridiplantae). Although these data have helped resolve the phylogeny of numerous clades (e.g., green algae, angiosperms, and gymnosperms), their utility for inferring relationships across all green plants is uncertain. Viridiplantae originated 700-1500 million years ago and may comprise as many as 500,000 species. This clade represents a major source of photosynthetic carbon and contains an immense diversity of life forms, including some of the smallest and largest eukaryotes. Here we explore the limits and challenges of inferring a comprehensive green plant phylogeny from available complete or nearly complete plastid genome sequence data.
Results
We assembled protein-coding sequence data for 78 genes from 360 diverse green plant taxa with complete or nearly complete plastid genome sequences available from GenBank. Phylogenetic analyses of the plastid data recovered well-supported backbone relationships and strong support for relationships that were not observed in previous analyses of major subclades within Viridiplantae. However, there also is evidence of systematic error in some analyses. In several instances we obtained strongly supported but conflicting topologies from analyses of nucleotides versus amino acid characters, and the considerable variation in GC content among lineages and within single genomes affected the phylogenetic placement of several taxa.
Conclusions
Analyses of the plastid sequence data recovered a strongly supported framework of relationships for green plants. This framework includes: i) the placement of Zygnematophyceace as sister to land plants (Embryophyta), ii) a clade of extant gymnosperms (Acrogymnospermae) with cycads + Ginkgo sister to remaining extant gymnosperms and with gnetophytes (Gnetophyta) sister to non-Pinaceae conifers (Gnecup trees), and iii) within the monilophyte clade (Monilophyta), Equisetales + Psilotales are sister to Marattiales + leptosporangiate ferns. Our analyses also highlight the challenges of using plastid genome sequences in deep-level phylogenomic analyses, and we provide suggestions for future analyses that will likely incorporate plastid genome sequence data for thousands of species. We particularly emphasize the importance of exploring the effects of different partitioning and character coding strategies.
http://www.biomedcentral.com/1471-2148/14/2
ISOLATION AND CHARACTERIZATION OF NOVEL MICROSATELLITE MARKERS FOR ARCTIUM MINUS (COMPOSITAE)
[EN] Premise of the study: Microsatellite primers were developed for the invasive plant Arctium minus to investigate the effects of
facultative self-pollination and the biannual habit on population genetic structure, as well as the colonization of the Americas by this Eurasian species. Methods and Results: Sixteen di- and trinucleotide microsatellite loci were identifi ed in six populations. The number of alleles
per locus ranged from one to 10, observed heterozygosities ranged from 0.000 to 0.897, and the mean value of F IS was 0.316.
Conclusions: These results indicate the utility of these loci in future studies of population genetics in A. minus .Peer reviewe
Performance and Comparison of Lithium-Ion Batteries Under Low-Earth-Orbit Mission Profiles
The performance of two 28 V, 25 Ah lithium-ion batteries is being evaluated under low-Earth-orbit mission profiles for satellite and orbiter applications. The batteries are undergoing life testing and have achieved over 12,000 cycles to 40 percent depth-of-discharge
Using and navigating the plant tree of life
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143797/1/ajb21071.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143797/2/ajb21071_am.pd
From algae to angiosperms–inferring the phylogeny of green plants (Viridiplantae) from 360 plastid genomes
Background Next-generation sequencing has provided a wealth of plastid genome sequence data from an increasingly diverse set of green plants (Viridiplantae). Although these data have helped resolve the phylogeny of numerous clades (e.g., green algae, angiosperms, and gymnosperms), their utility for inferring relationships across all green plants is uncertain. Viridiplantae originated 700-1500 million years ago and may comprise as many as 500,000 species. This clade represents a major source of photosynthetic carbon and contains an immense diversity of life forms, including some of the smallest and largest eukaryotes. Here we explore the limits and challenges of inferring a comprehensive green plant phylogeny from available complete or nearly complete plastid genome sequence data. Results We assembled protein-coding sequence data for 78 genes from 360 diverse green plant taxa with complete or nearly complete plastid genome sequences available from GenBank. Phylogenetic analyses of the plastid data recovered well-supported backbone relationships and strong support for relationships that were not observed in previous analyses of major subclades within Viridiplantae. However, there also is evidence of systematic error in some analyses. In several instances we obtained strongly supported but conflicting topologies from analyses of nucleotides versus amino acid characters, and the considerable variation in GC content among lineages and within single genomes affected the phylogenetic placement of several taxa. Conclusions Analyses of the plastid sequence data recovered a strongly supported framework of relationships for green plants. This framework includes: i) the placement of Zygnematophyceace as sister to land plants (Embryophyta), ii) a clade of extant gymnosperms (Acrogymnospermae) with cycads + Ginkgo sister to remaining extant gymnosperms and with gnetophytes (Gnetophyta) sister to non-Pinaceae conifers (Gnecup trees), and iii) within the monilophyte clade (Monilophyta), Equisetales + Psilotales are sister to Marattiales + leptosporangiate ferns. Our analyses also highlight the challenges of using plastid genome sequences in deep-level phylogenomic analyses, and we provide suggestions for future analyses that will likely incorporate plastid genome sequence data for thousands of species. We particularly emphasize the importance of exploring the effects of different partitioning and character coding strategies. http://www.biomedcentral.com/1471-2148/14/2
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Access to RNA-sequencing data from 1,173 plant species: The 1000 Plant transcriptomes initiative (1KP)
The 1000 Plant transcriptomes initiative (1KP) explored genetic diversity by sequencing RNA from 1,342 samples representing 1,173 species of green plants (Viridiplantae).This data release accompanies the initiative's final/capstone publication on a set of 3 analyses inferring species trees, whole genome duplications, and gene family expansions. These and previous analyses are based on de novo transcriptome assemblies and related gene predictions. Here, we assess their data and assembly qualities and explain how we detected potential contaminations.These data will be useful to plant and/or evolutionary scientists with interests in particular gene families, either across the green plant tree of life or in more focused lineages
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