2007 Microbial Population Biology (July 22-26, 2007) (open access)

2007 Microbial Population Biology (July 22-26, 2007)

Microbial Population Biology covers a diverse range of cutting edge issues in the microbial sciences and beyond. Firmly founded in evolutionary biology and with a strongly integrative approach, past meetings have covered topics ranging from the dynamics and genetics of adaptation to the evolution of mutation rate, community ecology, evolutionary genomics, altruism, and epidemiology. This meeting is never dull: some of the most significant and contentious issues in biology have been thrashed out here. We anticipate the 2007 meeting being no exception. The final form of the 2007 meeting is yet to be decided, but the following topics are likely to be included: evolutionary emergence of infectious disease and antibiotic resistance, genetic architecture and implications for the evolution of microbial populations, ageing in bacteria, biogeography, evolution of symbioses, the role of microbes in ecosystem function, and ecological genomics.
Date: April 1, 2008
Creator: Dean, Anthony M. & Gray, Nancy Ryan
System: The UNT Digital Library
7th Annual Systems Biology Symposium: Systems Biology and Engineering (open access)

7th Annual Systems Biology Symposium: Systems Biology and Engineering

Systems biology recognizes the complex multi-scale organization of biological systems, from molecules to ecosystems. The International Symposium on Systems Biology has been hosted by the Institute for Systems Biology in Seattle, Washington, since 2002. The annual two-day event gathers the most influential researchers transforming biology into an integrative discipline investingating complex systems. Engineering and application of new technology is a central element of systems biology. Genome-scale, or very small-scale, biological questions drive the enigneering of new technologies, which enable new modes of experimentation and computational analysis, leading to new biological insights and questions. Concepts and analytical methods in engineering are now finding direct applications in biology. Therefore, the 2008 Symposium, funded in partnership with the Department of Energy, featured global leaders in "Systems Biology and Engineering."
Date: April 1, 2008
Creator: Galitski, Timothy P.
System: The UNT Digital Library
Above- and below-ground biomass accumulation, production, and distribution of sweetgum and loblolly pine grown with irrigation and fertilization. (open access)

Above- and below-ground biomass accumulation, production, and distribution of sweetgum and loblolly pine grown with irrigation and fertilization.

Abstract: Increased forest productivity has been obtained by improving resource availability through water and nutrient amendments. However, more stress-tolerant species that have robust site requirements do not respond consistently to irrigation. An important factor contributing to robust site requirements may be the distribution of biomass belowground, yet available information is limited. We examined the accumulation and distribution of above- and below-ground biomass in sweetgum (Liqrridambar sfyrac$lua L.) and loblolly pine (Pinus taeda L.) stands receiving irrigation and fertilization. Mean annual aboveground production after 4 years ranged from 2.4 to 5.1 ~g.ha-'.year' for sweetgum and from 5.0 to 6.9 ~g.ha-l.year-l for pine. Sweetgum responded positively to irrigation and fertilization with an additive response to irrigation + fertilization. Pine only responded to fertilization. Sweetgum root mass fraction (RME)in creased with fertilization at 2 years and decreased with fertilization at 4 years. There were no detectable treatment differences in loblolly pine RMF. Development explained from 67% to 98% of variation in shoot versus root allometry for ephemeral and perennial tissues, fertilization explained no more than 5% of the variation in for either species, and irrigation did not explain any. We conclude that shifts in allocation from roots to shoots do not explain nutrient-induced …
Date: April 1, 2008
Creator: Coyle, David, R.; Coleman, Mark, D. & Aubrey, Doug, P.
System: The UNT Digital Library
Ambient-Pressure X-ray Photoelectron Spectroscopy (open access)

Ambient-Pressure X-ray Photoelectron Spectroscopy

This workshop focused on the application of ambient pressure X-ray photoelectron spectroscopy (APXPS) to environmental science and catalysis. Pioneering work on APXPS was done in the early 1970's by Hans and Kai Siegbahn et al., who demonstrated that XPS can operate at pressures of up to 1 Torr. A new type of APXPS instrument that utilizes a differentially-pumped electrostatic lens system at the ALS in 2001 increased the pressure limit to above 5 Torr, which opened the door to XPS experiments on water and aqueous solutions at temperatures above the melting point, in equilibrium with the vapor pressure of water. The impact of APXPS on fields such as environmental and atmospheric science as well as heterogeneous catalysis is already visible in numerous high impact publications. Today several other synchrotron facilities around the world have already implemented beam lines for APXPS or planning to do so in the near future. The goal of this workshop (organized by Miquel Salmeron (Molecular Foundry, LBNL), B. Simon Mun (Advanced Light Source, LBNL) and Hendrik Bluhm (Chemical Sciences Division, LBNL)) was to bring together researchers interested in the technique, review its current progress, discuss scientific opportunities and desirable technical improvements as well as consider the …
Date: April 1, 2008
Creator: Bluhm, Hendrik; Bluhm, Hendrik; Mun, Bongjin Simon & Salmeron, Miquel
System: The UNT Digital Library
The amphioxus genome and the evolution of the chordate karyotype (open access)

The amphioxus genome and the evolution of the chordate karyotype

Lancelets ('amphioxus') are the modern survivors of an ancient chordate lineage with a fossil record dating back to the Cambrian. We describe the structure and gene content of the highly polymorphic {approx}520 million base pair genome of the Florida lancelet Branchiostoma floridae, and analyze it in the context of chordate evolution. Whole genome comparisons illuminate the murky relationships among the three chordate groups (tunicates, lancelets, and vertebrates), and allow reconstruction of not only the gene complement of the last common chordate ancestor, but also a partial reconstruction of its genomic organization, as well as a description of two genome-wide duplications and subsequent reorganizations in the vertebrate lineage. These genome-scale events shaped the vertebrate genome and provided additional genetic variation for exploitation during vertebrate evolution.
Date: April 1, 2008
Creator: Putnam, Nicholas H.; Butts, Thomas; Ferrier, David E. K.; Furlong, Rebecca F.; Hellsten, Uffe; Kawashima, Takeshi et al.
System: The UNT Digital Library
Approaches to Modeling Coupled Flow and Reaction in a 2-D Cementation Experiment (open access)

Approaches to Modeling Coupled Flow and Reaction in a 2-D Cementation Experiment

Porosity evolution at reactive interfaces is a key process that governs the evolution and performances of many engineered systems that have important applications in earth and environmental sciences. This is the case, for example, at the interface between cement structures and clays in deep geological nuclear waste disposals. Although in a different transport regime, similar questions arise for permeable reactive barriers used for biogeochemical remediation in surface environments. The COMEDIE project aims at investigating the coupling between transport, hydrodynamics and chemistry when significant variations of porosity occur. The present work focuses on a numerical benchmark used as a design exercise for the future COMEDIE-2D experiment. The use of reactive transport simulation tools like Hytec and Crunch provides predictions of the physico-chemical evolutions that are expected during the future experiments in laboratory. Focus is given in this paper on the evolution during the simulated experiment of precipitate, permeability and porosity fields. A first case is considered in which the porosity is constant. Results obtained with Crunch and Hytec are in relatively good agreement. Differences are attributable to the models of reactive surface area taken into account for dissolution/precipitation processes. Crunch and Hytec simulations taking into account porosity variations are then presented …
Date: April 1, 2008
Creator: Steefel, Carl; Cochepin, B.; Trotignon, L.; Bildstein, O.; Steefel, C.; Lagneau, V. et al.
System: The UNT Digital Library
Approval of Waste Treatment and Immobilization Plant Contractor- Initiated Authorization Basis Amendment Requests (ABAR) (open access)

Approval of Waste Treatment and Immobilization Plant Contractor- Initiated Authorization Basis Amendment Requests (ABAR)

This report talks about Approval of Waste Treatment and Immobilization Plant Contractor- Initiated Authorization Basis Amendment Requests (ABAR)
Date: April 1, 2008
Creator: Gl, Jones
System: The UNT Digital Library
Beauty production at CDF (open access)

Beauty production at CDF

A review of recent measurements of beauty production, based on proton antiproton collision data at {radical}s = 1.96 TeV and using the CDF detector, is given. Previous measurements of beauty (b) quark production at the Tevatron, carried out at centre-of-mass energies {radical}s = 1.8 TeV, have shown discrepancies when compared to Next to Leading Order (NLO) predictions [1]. Improved predictions and experimental procedures have reduced this discrepancy [2]. Improved parton density functions, better fragmentation functions and more complete theoretical calculations have improved theoretical accuracy. Experimentally, measurements of beauty production at {radical}s = 1.96 TeV are now presented in terms of b hadrons or B mesons, to avoid problems unfolding back to the quark level. In this review [3] measurements of inclusive beauty (where one beauty jet or hadron is reconstructed in the event), and beauty + X (where X can be a boson or another beauty jet or hadron), production will be presented: inclusive beauty jet cross-section; semi and fully reconstructed B meson cross-section; beauty dijet cross-section; semi-reconstructed B B meson cross-section; Z boson + beauty jet cross-section. More information concerning other measurements of heavy quark production can be found elsewhere [4].
Date: April 1, 2008
Creator: Shears, Tara
System: The UNT Digital Library
Calculation of Reactive-evaporation Rates of Chromia (open access)

Calculation of Reactive-evaporation Rates of Chromia

A methodology is developed to calculate Cr-evaporation rates from Cr2O3 with a flat planar geometry. Variables include temperature, total pressure, gas velocity, and gas composition. The methodology was applied to solid-oxide, fuel cell conditions for metallic interconnects and to advanced-steam turbines conditions. The high velocities and pressures of the advanced steam turbine led to evaporation predictions as high as 5.18 9 10-8 kg/m2/s of CrO2(OH)2(g) at 760 °C and 34.5 MPa. This is equivalent to 0.080 mm per year of solid Cr loss. Chromium evaporation is expected to be an important oxidation mechanism with the types of nickel-base alloys proposed for use above 650 °C in advanced-steam boilers and turbines. It is shown that laboratory experiments, with much lower steam velocities and usually much lower total pressure than found in advanced steam turbines, would best reproduce chromium-evaporation behavior with atmospheres that approach either O2 + H2O or air + H2O with 57% H2O.
Date: April 1, 2008
Creator: Holcomb, G. R.
System: The UNT Digital Library
Carbon Dioxide Selective Supported Ionic Liquid Membranes: The Effect of Contaminants (open access)

Carbon Dioxide Selective Supported Ionic Liquid Membranes: The Effect of Contaminants

The integrated gasification combined cycle (IGCC) is widely viewed as a promising technology for the large scale production of energy in a carbon constrained world. These cycles, which include gasification, contaminant removal, water-gas shift, CO2 capture and compression, and combustion of the reduced-carbon fuel gas in a turbine, often have significant efficiency advantages over conventional combustion technologies. A CO2 selective membrane capable of maintaining performance at conditions approaching those of low temperature water-gas shift (260oC) could facilitate the production of carbon-neutral energy by simultaneously driving the shift reaction to completion and concentrating CO2 for sequestration. Supported ionic liquid membranes (SILMs) have been previously evaluated for this application and determined to be physically and chemically stable to temperatures in excess of 300oC. These membranes were based on ionic liquids which interacted physically with CO2 and diminished considerably in selectivity at higher temperatures. To alleviate this problem, the original ionic liquids were replaced with ionic liquids able to form chemical complexes with CO2. These complexing ionic liquid membranes have a local maximum in selectivity which is observed at increasing temperatures for more stable complexes. Efforts are currently underway to develop ionic liquids with selectivity maxima at temperatures greater than 75oC, the best …
Date: April 1, 2008
Creator: Luebke, D. R.; Ilconich, J. B.; Myers, C. R. & Pennline, H. W.
System: The UNT Digital Library
Changing lenses to assess biodiversity: patterns of species richness in sub-Antarctic plants and implications for global conservation (open access)

Changing lenses to assess biodiversity: patterns of species richness in sub-Antarctic plants and implications for global conservation

Article discussing patterns of species richness in sub-Antarctic plants and implications for global conservation.
Date: April 1, 2008
Creator: Rozzi, Ricardo, 1960-; Armesto, Juan J., 1953-; Goffinet, Bernard; Buck, William R., 1950-; Massardo, Francisca; Silander, John August, 1945- et al.
System: The UNT Digital Library
Climate, extreme heat, and electricity demand in California (open access)

Climate, extreme heat, and electricity demand in California

Climate projections from three atmosphere-ocean climate models with a range of low to mid-high temperature sensitivity forced by the Intergovernmental Panel for Climate Change SRES higher, middle, and lower emission scenarios indicate that, over the 21st century, extreme heat events for major cities in heavily air-conditioned California will increase rapidly. These increases in temperature extremes are projected to exceed the rate of increase in mean temperature, along with increased variance. Extreme heat is defined here as the 90 percent exceedance probability (T90) of the local warmest summer days under the current climate. The number of extreme heat days in Los Angeles, where T90 is currently 95 F (32 C), may increase from 12 days to as many as 96 days per year by 2100, implying current-day heat wave conditions may last for the entire summer, with earlier onset. Overall, projected increases in extreme heat under the higher A1fi emission scenario by 2070-2099 tend to be 20-30 percent higher than those projected under the lower B1 emission scenario, ranging from approximately double the historical number of days for inland California cities (e.g. Sacramento and Fresno), up to four times for previously temperate coastal cities (e.g. Los Angeles, San Diego). These findings, …
Date: April 1, 2008
Creator: Miller, N. L.; Hayhoe, K.; Jin, J. & Auffhammer, M.
System: The UNT Digital Library
Closure Strategy for a Waste Disposal Facility with Multiple Waste Types and Regulatory Drivers at the Nevada Test Site (open access)

Closure Strategy for a Waste Disposal Facility with Multiple Waste Types and Regulatory Drivers at the Nevada Test Site

The U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) plans to close the waste and classified material storage cells in the southeast quadrant of the Area 5 Radioactive Waste Management Site (RWMS), informally known as the '92-Acre Area', by 2011. The 25 shallow trenches and pits and the 13 Greater Confinement Disposal (GCD) borings contain various waste streams including low-level waste (LLW), low-level mixed waste (LLMW), transuranic (TRU), mixed transuranic (MTRU), and high specific activity LLW. The cells are managed under several regulatory and permit programs by the U.S. Department of Energy (DOE) and the Nevada Division of Environmental Protection (NDEP). Although the specific closure requirements for each cell vary, 37 closely spaced cells will be closed under a single integrated monolayer evapotranspirative (ET) final cover. One cell will be closed under a separate cover concurrently. The site setting and climate constrain transport pathways and are factors in the technical approach to closure and performance assessment. Successful implementation of the integrated closure plan requires excellent communication and coordination between NNSA/NSO and the regulators.
Date: April 1, 2008
Creator: D. Wieland, V. Yucel, L. Desotell, G. Shott, J. Wrapp
System: The UNT Digital Library
Considerations on ODR beam-size monitoring for gamma = 1000 beams (open access)

Considerations on ODR beam-size monitoring for gamma = 1000 beams

We discuss the feasibility of monitoring the beam size of {gamma} = 1000 beams with 3000 times more charge in a video frame time and with a more sensitive 12- to 16-bit camera than were used in the previous electron beam studies at 7 GeV at the Advanced Photon Source. Such a beam would be generated at Fermilab in a new facility in the coming years. Numerical integrations of our base model show beam size sensitivity for {+-} 20% level changes at 200- and 400-{micro}m base beam sizes. We also evaluated impact parameters of 5 {sigma}{sub y} and 12 {sigma}{sub y} for both 800-nm and 10-{micro}m observation wavelengths. The latter examples are related to a proposal to apply the technique to an {approx}0.98 TeV proton beam, and this study shows there are trades on photon intensity and beam size sensitivity to be considered at such gammas. In addition, we report on first results at {gamma} = 1800 on a superconducting rf linac.
Date: April 1, 2008
Creator: Lumpkin, A. H.; /Fermilab; Yao, C.-Y.; /Argonne; Chiadroni, E.; Castellano, M. et al.
System: The UNT Digital Library
Constraints on parton density functions from D0 (open access)

Constraints on parton density functions from D0

Five recent results from D0 which either impact or have the potential to impact on uncertainties in parton density functions are presented. Many analyses at D0 are sensitive to the modeling of the partonic structure of the proton. When theoretical and experimental uncertainties are well controlled there exists the possibility for additional constraints on parton density functions (PDF). Five measurements are presented which either have already been included in global parton fits or have the potential to contribute in the future.
Date: April 1, 2008
Creator: Hays, Jonathan M.
System: The UNT Digital Library
Design Configurations and Coupling High Temperature Gas-Cooled Reactor and Hydrogen Plant (open access)

Design Configurations and Coupling High Temperature Gas-Cooled Reactor and Hydrogen Plant

The US Department of Energy is investigating the use of high-temperature nuclear reactors to produce hydrogen using either thermochemical cycles or high-temperature electrolysis. Although the hydrogen production processes are in an early stage of development, coupling either of these processes to the high-temperature reactor requires both efficient heat transfer and adequate separation of the facilities to assure that off-normal events in the production facility do not impact the nuclear power plant. An intermediate heat transport loop will be required to separate the operations and safety functions of the nuclear and hydrogen plants. A next generation high-temperature reactor could be envisioned as a single-purpose facility that produces hydrogen or a dual-purpose facility that produces hydrogen and electricity. Early plants, such as the proposed Next Generation Nuclear Plant (NGNP), may be dual-purpose facilities that demonstrate both hydrogen and efficient electrical generation. Later plants could be single-purpose facilities. At this stage of development, both single- and dual-purpose facilities need to be understood.
Date: April 1, 2008
Creator: Oh, Chang H.; Kim, Eung Soo & Sherman, Steven
System: The UNT Digital Library
The Development of Interconnection Standards in Six States In 2007-2008 (open access)

The Development of Interconnection Standards in Six States In 2007-2008

This paper discusses the process of developing standards for the interconnection of photovoltaic systems and other generators under ten megawatts to the electric grid. State utility commission rulemakings in 2007-2008 in Florida, New Mexico, North Carolina, Maryland, Illinois and Utah provide the basis for analysis of what is and should be considered in the development of standards, and how the process can be improved. State interconnection standards vary substantially, and many utilities have discretion to establish additional or different requirements, creating literally hundreds of sets of rules. This lack of uniformity imposes a significant cost on project developers and installers to track and comply with applicable rules. As well, burdensome provisions and uncertain costs and timelines present formidable barriers to entry, which advocates have limited resources to challenge. For a better process, the author proposes: establishing federal standards as a baseline, involving solar advocates, and developing a utility cost-recovery mechanism.
Date: April 1, 2008
Creator: Keyes, Jason B.
System: The UNT Digital Library
Diffractive W/Z and exclusive dijet production at CDF II (open access)

Diffractive W/Z and exclusive dijet production at CDF II

We report preliminary single-diffractive W/Z and final exclusive dijet production results for {bar p}p collisions at {radical}s = 1.96 TeV extracted from data collected by the CDF II detector at the Fermilab Tevatron. The results are compared with previous measurements, and the obtained exclusive dijet cross sections are used to constrain/calibrate theoretical models for exclusive Higgs boson production rates at the Large Hadron Collider.
Date: April 1, 2008
Creator: Goulianos, Konstantin
System: The UNT Digital Library
Effects of Temperature Gradients and Heat Fluxes on High-Temperature Oxidation (open access)

Effects of Temperature Gradients and Heat Fluxes on High-Temperature Oxidation

The effects of a temperature gradient and heat flux on point defect diffusion in protective oxide scales were examined. Irreversible thermodynamics were used to expand Fick’s first law of diffusion to include a heat-flux term—a Soret effect. Oxidation kinetics were developed for the oxidation of cobalt and of nickel doped with chromium. Research is described to verify the effects of a heat flux by oxidizing pure cobalt in a temperature gradient at 900 °C, and comparing the kinetics to isothermal oxidation. No evidence of a heat flux effect was found.
Date: April 1, 2008
Creator: Holcomb, G. R.
System: The UNT Digital Library
Electrical Contacts to Individual Colloidal Semiconductor Nanorods (open access)

Electrical Contacts to Individual Colloidal Semiconductor Nanorods

We report the results of charge transport studies on single CdTe nanocrystals contacted via evaporated Pd electrodes. Device charging energy, E{sub c}, monitored as a function of electrode separation drops suddenly at separations below {approx}55 nm. This drop can be explained by chemical changes induced by the metal electrodes. This explanation is corroborated by ensemble X-Ray photoelectron spectroscopy (XPS) studies of CdTe films as well as single particle measurements by transmission electron microscopy (TEM) and energy dispersive X-Rays (EDX). Similar to robust optical behavior obtained when Nanocrystals are coated with a protective shell, we find that a protective SiO2 layer deposited between the nanocrystal and the electrode prevents interface reactions and an associated drop in E{sub c,max}. This observation of interface reactivity and its effect on electrical properties has important implications for the integration of nanocrystals into conventional fabrication techniques and may enable novel nano-materials.
Date: April 1, 2008
Creator: Trudeau, Paul-Emile; Sheldon, Matt; Altoe, Virginia & Alivisatos, A. Paul
System: The UNT Digital Library
First Observation of the Cabibbo-suppressed Decays Xi+(c) ---> Sigma+ pi- pi+ and Xi+(c) ---> Sigma- pi+ pi+ and Measurement of their Branching Ratios (open access)

First Observation of the Cabibbo-suppressed Decays Xi+(c) ---> Sigma+ pi- pi+ and Xi+(c) ---> Sigma- pi+ pi+ and Measurement of their Branching Ratios

The authors report the first observation of two Cabibbo-suppressed decay modes, {Xi}{sub c}{sup +} {yields} {Sigma}{sup +}{pi}{sup -}{pi}{sup +} and {Xi}{sub c}{sup +} {yields} {Sigma}{sup -} {pi}{sup +}{pi}{sup +}. They observe 56 {+-} 13 over a background of 21, and 23 {+-} 7 over a background of 12 events, respectively, for the signals. The data were accumulated using the SELEX spectrometer during the 1996-1997 fixed target run at Fermilab, chiefly from a 600 GeV/c {Sigma}{sup -} beam. The branching ratios of the decays relative to the Cabibbo-favored {Xi}{sub c}{sup +} {yields} {Xi}{sup -}{pi}{sup +}{pi}{sup +} are measured to be B({Xi}{sub c}{sup +} {yields} {Sigma}{sup +}{pi}{sup -}{pi}{sup +})/B({xi}{sub c}{sup +} {yields} {Xi}{sup -} {pi}{sup +}{pi}{sup +}) = 0.50 {+-} 0.20, and B({Xi}{sub c}{sup +} {yields} {Sigma}{sup -}{pi}{sup +}{pi}{sup +})/B({Xi}{sub c}{sup +} {yields} {Xi}{sup -}{pi}{sup +}{pi}{sup +}) = 0.23 {+-} 0.11, respectively. They also report branching ratios for the same decay modes of the {Lambda}{sub c}{sup +} relative to {Lambda}{sub c}{sup +} {yields} pK{sup -}{pi}{sup +}.
Date: April 1, 2008
Creator: Vazquez-Jauregui, E.; U., /San Luis Potosi; Engelfried, J.; U., /San Luis Potosi; Akgun, U.; U., /Iowa et al.
System: The UNT Digital Library
Fuel Cell Vehicle Learning Demonstration: Spring 2008 Results; Preprint (open access)

Fuel Cell Vehicle Learning Demonstration: Spring 2008 Results; Preprint

Conference paper presented at the 2008 National Hydrogen Association Meeting that describes the spring, 2008 results of the Controlled Hydrogen Fleet and Infrastructure Demonstration and Validation Project.
Date: April 1, 2008
Creator: Wipke, K.; Sprik, S.; Kurtz, J. & Garbak, J.
System: The UNT Digital Library
Gas-Crossover and Membrane-Pinhole Effects in Polymer-Electrolyte Fuel Cells (open access)

Gas-Crossover and Membrane-Pinhole Effects in Polymer-Electrolyte Fuel Cells

This paper investigates the effects of gas crossover. Specifically, mathematical simulations are conducted to elucidate the fundamental changes in fuel-cell operation as permeation of the various gases through the membrane increases. Two cases are explored, with the first one examining uniform increases in the set of gas-permeation coefficients, and the second one the existence of regions of high gas crossover (i.e., membrane pinholes). For the first case, operation at 120 C is studied and a maximum limit for the hydrogen permeation coefficient of 1 x 10{sup -10} mol/bar-cm-s for a 25 {micro}m membrane is determined. For the second case, it is shown that negative current densities and temperature spikes can arise due to mixed-potential and direct-combustion effects where there are large enough pinholes, thereby impacting performance and water and thermal management.
Date: April 1, 2008
Creator: Weber, Adam & Weber, Adam Z.
System: The UNT Digital Library
Habitat-Lite: A GSC case study based on free text terms for environmental metadata (open access)

Habitat-Lite: A GSC case study based on free text terms for environmental metadata

There is an urgent need to capture metadata on the rapidly growing number of genomic, metagenomic and related sequences, such as 16S ribosomal genes. This need is a major focus within the Genomic Standards Consortium (GSC), and Habitat is a key metadata descriptor in the proposed 'Minimum Information about a Genome Sequence' (MIGS) specification. The goal of the work described here is to provide a light-weight, easy-to-use (small) set of terms ('Habitat-Lite') that captures high-level information about habitat while preserving a mapping to the recently launched Environment Ontology (EnvO). Our motivation for building Habitat-Lite is to meet the needs of multiple users, such as annotators curating these data, database providers hosting the data, and biologists and bioinformaticians alike who need to search and employ such data in comparative analyses. Here, we report a case study based on semi-automated identification of terms from GenBank and GOLD. We estimate that the terms in the initial version of Habitat-Lite would provide useful labels for over 60% of the kinds of information found in the GenBank isolation-source field, and around 85% of the terms in the GOLD habitat field. We present a revised version of Habitat-Lite and invite the community's feedback on its further …
Date: April 1, 2008
Creator: Kyrpides, Nikos; Hirschman, Lynette; Clark, Cheryl; Cohen, K. Bretonnel; Mardis, Scott; Luciano, Joanne et al.
System: The UNT Digital Library