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Translating the cancer genome: Going beyond p values

Description: Cancer cells are endowed with diverse biological capabilities driven by myriad inherited and somatic genetic and epigenetic aberrations that commandeer key cancer-relevant pathways. Efforts to elucidate these aberrations began with Boveri's hypothesis of aberrant mitoses causing cancer and continue today with a suite of powerful high-resolution technologies that enable detailed catalogues of genomic aberrations and epigenomic modifications. Tomorrow will likely bring the complete atlas of reversible and irreversible alteration in individual cancers. The challenge now is to discern causal molecular abnormalities from genomic and epigenomic 'noise', to understand how the ensemble of these aberrations collaborate to drive cancer pathophysiology. Here, we highlight lessons learned from now classical examples of successful translation of genomic discoveries into clinical practice, lessons that may be used to guide and accelerate translation of emerging genomic insights into practical clinical endpoints that can impact on practice of cancer medicine.
Date: April 3, 2008
Creator: Chin, Lynda; Chin, Lynda & Gray, Joe W.
Partner: UNT Libraries Government Documents Department

Diversity of Decline-Rate-Corrected Type 1a Supernova Rise times:One Mode or Two?

Description: B-band light-curve rise times for eight unusually well-observed nearby Type Ia supernova (SNe) are fitted by a newly developed template-building algorithm, using light-curve functions that are smooth, flexible, and free of potential bias from externally derived templates and other prior assumptions. From the available literature, photometric BVRI data collected over many months, including the earliest points, are reconciled, combined, and fitted to a unique time of explosion for each SN. On average, after they are corrected for light-curve decline rate, three SNe rise in 18.81 {+-} 0.36 days, while five SNe rise in 16.64 {+-} 0.21 days. If all eight SNe are sampled from a single parent population (a hypothesis not favored by statistical tests), the rms intrinsic scatter of the decline-rate-corrected SN rise time is 0.96{sub -0.25}{sup +0.52} days--a first measurement of this dispersion. The corresponding global mean rise time is 17.44 {+-} 0.39 days, where the uncertainty is dominated by intrinsic variance. This value is {approx}2 days shorter than two published averages that nominally are twice as precise, though also based on small samples. When comparing high-z to low-z SN luminosities for determining cosmological parameters, bias can be introduced by use of a light-curve template with an unrealistic rise time. If the period over which light curves are sampled depends on z in a manner typical of current search and measurement strategies, a two-day discrepancy in template rise time can bias the luminosity comparison by {approx}0.03 magnitudes.
Date: May 1, 2007
Creator: Strovink, Mark
Partner: UNT Libraries Government Documents Department

The complete mitochondrial sequence of the"living fossil" Tricholepidion gertschi: structure, phylogenetic implications, and the description of a novel A/T asymmetrical bias

Description: Traditionally, the 'Apterygota' has been thought to consist of five orders of wingless hexapods (Protura, Collembola, Diplura, Microcoryphia and Zygentoma) believed to be collectively basal to insects (i.e., the Pterygota). However, some studies have questioned this affinity with insects (Dallai, Abele, Spears, Nardi). Further, within these groups are hotly debated issues, including the monophyly of Entognata (Koch, 1997; Kukalova Peck, 1987), the monophyly of Diplura (Bilinski, 1993; Stys and Bilinski, 1990), the affinity between Collembola and Protura (Dallai, 1994; Kristensen, 1981) and the position of Lepidotrichidae (below). In fact, these relationships constitute one of the most debated issues in hexapod phylogeny. The family Lepidotrichidae was first described by (Silvestri, 1912) (1912: 'Lepidothricinae') from a Baltic Amber fossil (Lepidothrix pilifera Menge). The only living representative of this family is Tricholepidion gertschi Wygodzinski. Since this species was first described (Wygodzinsky, 1961) its phylogenetic position has been difficult to establish, due to an 'array of unique characters' that are difficult to interpret in a phylogenetic framework. Tricholepidion (and therefore the whole family Lepidotrichidae) has been considered either as belonging to the order Zygentoma (Kristensen, 1997; Wygodzinsky, 1961), or basal to the rest of the Zygentoma plus the Pterygota (Beutel, 2001; Bitsch and Bitsch, 2000; Staniczek, 2000), although the significance of some of the morphological characters on which these analyses are based have been questioned (Dallai et al., 2001; Kristensen, 1997). If the latter hypothesis proved to be true, the family Lepidotrichidae, would better deserve the ordinal rank. Since studies based on morphological characters have failed to give a satisfactory answer, a broad scale molecular study is under way ((Nardi et al., 2001), Frati et al, submitted, il Gomphiocephalus) in order to use mitochondrial genome sequences to study the evolution and differentiation of the most basal hexapod groups, including Tricholepidion. Mitochondrial genomics, that is ...
Date: June 23, 2002
Creator: Nardi, F.; Frati, F.; Carapelli, A.; Dallai, R. & Boore, J.
Partner: UNT Libraries Government Documents Department

Seismicity Precursors of the M6.0 2004 Parkfield and M7.0 1989Loma Prieta Earthquakes

Description: The M6.0 2004 Parkfield and M7.0 1989 Loma Prietastrike-slip earthquakes on the San Andreas Fault (SAF) were preceded byseismicity peaks occurring several months prior to the main events.Earthquakes directly within the SAF zone were intentionally excluded fromthe analysis because they manifest stress-release processes rather thanstress accumulation. The observed increase in seismicity is interpretedas a signature of the increasing stress level in the surrounding crust,whereas the peaks and the subsequent decrease in seismicity areattributed to damage-induced softening processes. Furthermore, in bothcases there is a distinctive zone of low seismic activity that surroundsthe epicentral region in the pre-event period. The increase of seismicityin the crust surrounding a potential future event and the development ofa low-seismicity epicentral zone can be regarded as promising precursoryinformation that could help signal the arrival of large earthquakes. TheGutenberg-Richter relationship (GRR) should allow extrapolation ofseismicity changes down to seismic noise level magnitudes. Thishypothesis is verified by comparison of seismic noise at 80 Hz with theParkfield M4 1993-1994 series, where noise peaks 5 months before theseries to about twice the background level.
Date: March 9, 2006
Creator: Korneev, Valeri A.
Partner: UNT Libraries Government Documents Department

A Monte Carlo Study of the Robustness and Power Associated with Selected Tests of Variance Equality when Distributions are Non-Normal and Dissimilar in Form

Description: When selecting a method for testing variance equality, a researcher should select a method which is robust to distribution non-normality and dissimilarity. The method should also possess sufficient power to ascertain departures from the equal variance hypothesis. This Monte Carlo study examined the robustness and power of five tests of variance equality under specific conditions. The tests examined included one procedure proposed by O'Brien (1978), two by O'Brien (1979), and two by Conover, Johnson, and Johnson (1981). Specific conditions included assorted combinations of the following factors: k=2 and k=3 groups, normal and non-normal distributional forms, similar and dissimilar distributional forms, and equal and unequal sample sizes. Under the k=2 group condition, a total of 180 combinations were examined. A total of 54 combinations were examined under the k=3 group condition. The Type I error rates and statistical power estimates were based upon 1000 replications in each combination examined. Results of this study suggest that when sample sizes are relatively large, all five procedures are robust to distribution non-normality and dissimilarity, as well as being sufficiently powerful.
Date: August 1990
Creator: Hardy, James C. (James Clifford)
Partner: UNT Libraries

A Proposed Experimental Test of the Neutrino Theory

Description: The experiment outlined in this proposal has the possibility of giving an answer to the important question, 'Does the neutrino exist'? It is unfortunate that at the present time, there is no convincing experimental that neutrinos exist. Two recent articles review the status of various experiments which could give information about neutrinos. In general, these experiments give results in agreement with the predictions of beta decay theory. But actually, if even the most complete of the 'recoil type' experiments could be performed satisfactorily, all that could be concluded would be the following: the energy and momentum relationships in beta decay are consistent with the theory that the known energy deficit is carried away by a single particle. But to emphasize the fact that this would not constitute a proof of the real existence of that particle, the following quotations from the review articles should be noted. Crane says, 'All of the evidence about the neutrino is, as already pointed out, indirect in character since neutrinos have not yet been caught after leaving the nucleus. It can, of course, be argued on very general grounds that, if energy is not conserved between nucleus and electron, momentum should not be expected to be conserved either, and in consequence of this, it has often been remarked that the recoiled experiments add nothing that is really new to their knowledge'. Allen concludes his article by saying, 'Practically all the experimental evidence indicates that there is an apparent non-conservation of momentum in the beta decay process, and that the neutrino hypothesis is at least one explanation of the missing momentum'.
Date: April 18, 1949
Creator: Alvarez, Luis W.
Partner: UNT Libraries Government Documents Department

PECULIAR OPTICAL AND IR BEHAVIOUR IN TYPE I SUPERNOVAE, AND THE ORIGIN OF THE 1.2 ABSORPTION

Description: A small number of type I supernovae exhibit well defined peculiarities. In particular some type I supernovae do not have the characteristic 6150 {angstrom} feature and some do not have the 1.2 {micro}m absorption. It is noted that all SN which lack the infrared absorption also lack the 6150 {angstrom} feature which is attributed to Si II. It is proposed that these supernovae constitute a single sub-class and that Si could be responsible for the strong unidentified infrared absorption which is characteristic of classical SNI. Si I has a dense array of strong lines in the near infrared so this ion could be responsible for the dominant features of SNIa IR behaviour. If this hypothesis is vindicated by subsequent observations or by calculation of synthetic spectra then it is most likely that the difference between ordinary supernovae and these peculiar ones is the abundance of Si.
Date: November 1, 1985
Creator: Graham, J.R.
Partner: UNT Libraries Government Documents Department

Discovery of Non-random Spatial Distribution of Impacts in the Stardust Cometary Collector

Description: We report the discovery that impacts in the Stardust cometary collector are not distributed randomly in the collecting media, but appear to be clustered on scales smaller than {approx} 10 cm. We also report the discovery of at least two populations of oblique tracks. We evaluated several hypotheses that could explain the observations. No hypothesis was consistent with all the observations, but the preponderance of evidence points toward at least one impact on the central Whipple shield of the spacecraft as the origin of both clustering and low-angle oblique tracks. High-angle oblique tracks unambiguously originate from a non-cometary impact on the spacecraft bus just forward of the collector.
Date: April 6, 2007
Creator: Westphal, A J; Bastien, R K; Borg, J; Bridges, J; Brownlee, D E; Burchell, M J et al.
Partner: UNT Libraries Government Documents Department

Simple classifiers from data dependent hypothesis classes

Description: In this paper we introduce simple classifiers as an example of how to use the data dependent hypothesis class framework described by Cannon et al. (2002) to explore the performance/computation trade-off in the classifier design problem. We provide a specific example of a simple classifier and demonstrate that it has many remarkable properties: For example it possesses computationally efficient learning algorithms with favorable bounds on estimation error, admits kernel mappings, and is particularly well suited to boosting. We present experimental results on synthetic and real data that suggest that this classifier is competitive with powerful alternative methods.
Date: January 1, 2003
Creator: Cannon, A. (Adam); Howse, J. W. (James W.); Hush, D. R. (Donald R.) & Scovel, James C.
Partner: UNT Libraries Government Documents Department

Weighted order statistic classifiers with large rank-order margin.

Description: We describe how Stack Filters and Weighted Order Statistic function classes can be used for classification problems. This leads to a new design criteria for linear classifiers when inputs are binary-valued and weights are positive . We present a rank-based measure of margin that can be directly optimized as a standard linear program and investigate its effect on generalization error with experiment. Our approach can robustly combine large numbers of base hypothesis and easily implement known priors through regularization.
Date: January 1, 2003
Creator: Porter, R. B. (Reid B.); Hush, D. R. (Donald R.); Theiler, J. P. (James P.) & Gokhale, M. (Maya)
Partner: UNT Libraries Government Documents Department

Fearful Faces do Not Lead to Faster Attentional Deployment in Individuals with Elevated Psychopathic Traits

Description: This article discusses a gaze-cueing experiment in which the predictivity of a gaze-cue was manipulated to assess the degree to which individuals with elevated psychopathic traits can use contextual information.
Date: June 30, 2017
Creator: Hoppenbrouwers, Sylvo S.; Munneke, Jaap; Kooiman, Karen A.; Little, Bethany; Neumann, Craig S. & Theeuwes, Jan
Partner: UNT College of Arts and Sciences

The chi square approximation to the hypergeometric probability distribution

Description: This study compared the results of his chi square text of independence and the corrected chi square statistic against Fisher's exact probability test (the hypergeometric distribution) in contection with sampling from a finite population. Data were collected by advancing the minimum call size from zero to a maximum which resulted in a tail area probability of 20 percent for sample sizes from 10 to 100 by varying increments.
Date: August 1982
Creator: Anderson, Randy J. (Randy Jay)
Partner: UNT Libraries

DECAY PROPERTIES OF THE E HYPERON AND E RESONANCES

Description: A sample of 2500 {Xi}{sup -} and 500 {Xi}{sup 0} hyperons, produced in {Xi}K, {Xi}K{pi}, and {Xi}K{pi}{pi} final states by K{sup -} (in H{sub 2}) at incident momenta of 1.7 to 2.7 BeV/c, has been analyzed. The data are from an exposure (K-63) of 26 events/{mu}b in the 72-inch bubble chamber; approximately 85% of the {Xi}{sup -} events and 60% of the {Xi}{sup 0} events have been analyzed. For the {Xi}, they determine the spin and decay parameters a{sub {Xi}} and {Phi}{sub {Xi}} = tan{sup -1} ({beta}{sub {Xi}}/{Gamma}{sub {Xi}}). Combining their data with 900 {Xi}{sup -} and 150 {Xi}{sup 0} events from an earlier experiment (K-72), they obtain the following results: (1) {Xi} spin - J = 1/2 favored over J = 3/2 by {approx} 2.5 standard deviations; (2) {Xi} decay parameters (assuming a{sub {Lambda}} = 0.647 {+-} 0.048) - a{sub {Xi}{sup -}} = -0.398 {+-} 0.041, {Phi}{sub {Xi}{sup -}} = 9.8{sup o} {+-} 9.0{sup o}; a{sub {Xi}{sup 0}} = -0.413 {+-} 0.104. They observe {Xi}*(1530) and {Xi}*(1817); their data are insufficient for analysis of suggested {Xi}* resonances at 1705 and 1933 MeV. They measure the {Xi}*(1530) electromagnetic mass difference {Delta}m = m({Xi}*{sup -}) = m({Xi}*{sup 0}) = 2.0 {+-} 3.2 MeV. Using data, part of which has already been described, they find for {Xi}*(1530): J {ge} 3/2 favored over J = 1/2 (the J = 1/2 hypothesis is {approx} 3.5% as probable as the J = 3/2 hypothesis); J{sup P} = 3/2{sup +} favored over 3/2{sup -} by {approx} 2.8 standard deviations. For {Xi}*(1817) decaying into {Xi}*(1530) + {pi}, the hypotheses J{sup P} = 1/2{sup +}, 1/2{sup -}, 3/2{sup -}, 5/2{sup +}, 7/2{sup -}, etc. (corresponding to {ell} = 1, 2, 0 and 2, 1 and 3, and 2 and 4, respectively) are favored over other hypotheses, but results ...
Date: September 10, 1966
Creator: Merrill, Jr., Deane W.
Partner: UNT Libraries Government Documents Department

Comparison of the oxidation state of Fe in comet 81P/Wild 2 and chondritic-porous interplanetary dust particles

Description: The fragile structure of chondritic-porous interplanetary dust particles (CP-IDPs) and their minimal parent-body alteration have led researchers to believe these particles originate in comets rather than asteroids where aqueous and thermal alterations have occurred. The solar elemental abundances and atmospheric entry speed of CP-IDPs also suggest a cometary origin. With the return of the Stardust samples from Jupiter-family comet 81P/Wild 2, this hypothesis can be tested. We have measured the Fe oxidation state of 15 CP-IDPs and 194 Stardust fragments using a synchrotron-based x-ray microprobe. We analyzed {approx}300 ng of Wild 2 material - three orders of magnitude more material than other analyses comparing Wild 2 and CP-IDPs. The Fe oxidation state of these two samples of material are > 2{sigma} different: the CP-IDPs are more oxidized than the Wild 2 grains. We conclude that comet Wild 2 contains material that formed at a lower oxygen fugacity than the parent-body, or parent bodies, of CP-IDPs. If all Jupiter-family comets are similar, they do not appear to be consistent with the origin of CP-IDPs. However, comets that formed from a different mix of nebular material and are more oxidized than Wild 2 could be the source of CP-IDPs.
Date: July 16, 2010
Creator: Ogliore, Ryan C.; Butterworth, Anna L.; Fakra, Sirine C.; Gainsforth, Zack; Marcus, Matthew A. & Westphal, Andrew J.
Partner: UNT Libraries Government Documents Department

Assessing the Impacts of Reduced Noise Operations of Wind Turbines on Neighbor Annoyance: A Preliminary Analysis in Vinalhaven, Maine

Description: Neighbors living near the 3 turbine, 4.5 MW Vinalhaven, Maine wind power facility, which began operations in late 2009, have complained that the noise from the turbines is unwelcome and annoying. Fox Islands Wind, the owner of the facility, hypothesized that implementing a Noise Reduced Operation (NRO) for the turbines, which effectively limits the turbines maximum rpm and power output, would reduce the sound levels produced by the turbines, and therefore might also reduce the degree to which the neighbors report being annoyed by those sounds. To test this hypothesis in a preliminary fashion, a pilot study was conducted in early 2010, the results of which are the subject of this brief report. The study included asking near-by residents - those within roughly 3000 feet - to rate the sounds and the degree to which they were annoyed by them using logs which they filled out at multiple times during the day on as many days as were possible in the 35 day study period in February and March, 2010. Meanwhile, FIW adjusted the NRO settings of the turbines in a random fashion in the evenings during the same period, but in a pattern that the respondents were not made aware of. Ultimately, nine individuals turned in roughly 200 log entries (i.e., responses), each of which was time coded to allow testing if the response was correlated with the wind facility operating conditions at that time. The analysis of these data found small, non-statistically-significant differences in self-reported turbine loudness and annoyance ratings between the periods when the NRO was enacted and when it was not, after controlling for many of the relationships that could independently influence perceived loudness and annoyance (e.g., wind direction, time of day). Possible explanations for these small differences in self-reported turbine loudness and annoyance ratings include: ...
Date: June 23, 2010
Creator: Hoen, Ben; Wiser, Ryan & Eckholdt, Haftan
Partner: UNT Libraries Government Documents Department

Widespread Discordance of Gene Trees with Species Tree inDrosophila: Evidence for Incomplete Lineage Sorting

Description: The phylogenetic relationship of the now fully sequencedspecies Drosophila erecta and D. yakuba with respect to the D.melanogaster species complex has been a subject of controversy. All threepossible groupings of the species have been reported in the past, thoughrecent multi-gene studies suggest that D. erecta and D. yakuba are sisterspecies. Using the whole genomes of each of these species as well as thefour other fully sequenced species in the subgenus Sophophora, we set outto investigate the placement of D. erecta and D. yakuba in the D.melanogaster species group and to understand the cause of the pastincongruence. Though we find that the phylogeny grouping D. erecta and D.yakuba together is the best supported, we also find widespreadincongruence in nucleotide and amino acid substitutions, insertions anddeletions, and gene trees. The time inferred to span the two keyspeciation events is short enough that under the coalescent model, theincongruence could be the result of incomplete lineage sorting.Consistent with the lineage-sorting hypothesis, substitutions supportingthe same tree were spatially clustered. Support for the different treeswas found to be linked to recombination such that adjacent genes supportthe same tree most often in regions of low recombination andsubstitutions supporting the same tree are most enriched roughly on thesame scale as linkage disequilibrium, also consistent with lineagesorting. The incongruence was found to be statistically significant androbust to model and species choice. No systematic biases were found. Weconclude that phylogenetic incongruence in the D. melanogaster speciescomplex is the result, at least in part, of incomplete lineage sorting.Incomplete lineage sorting will likely cause phylogenetic incongruence inmany comparative genomics datasets. Methods to infer the correct speciestree, the history of every base in the genome, and comparative methodsthat control for and/or utilize this information will be valuableadvancements for the field of comparative genomics.
Date: August 28, 2006
Creator: Pollard, Daniel A.; Iyer, Venky N.; Moses, Alan M. & Eisen,Michael B.
Partner: UNT Libraries Government Documents Department

Extracellular Matrix, Nuclear and Chromatin Structure and Gene Expression in Normal Tissues and Malignant Tumors: A Work in Progress

Description: Almost three decades ago, we presented a model where theextracellular matrix (ECM) was postulated to influence gene expressionand tissue-specificity through the action of ECM receptors and thecytoskeleton. This hypothesis implied that ECM molecules could signal tothe nucleus and that the unit of function in higher organisms was not thecell alone, but the cell plus its microenvironment. We now know that ECMinvokes changes in tissue and organ architecture and that tissue, cell,nuclear, and chromatin structure are changed profoundly as a result ofand during malignant progression. Whereas some evidence has beengenerated for a link between ECM-induced alterations in tissuearchitecture and changes in both nuclear and chromatin organization, themanner by which these changes actively induce or repress gene expressionin normal and malignant cells is a topic in need of further attention.Here, we will discuss some key findings that may provide insights intomechanisms through which ECM could influence gene transcription and howtumor cells acquire the ability to overcome these levels ofcontrol.
Date: August 1, 2006
Creator: Spencer, Virginia A.; Xu, Ren & Bissell, Mina J.
Partner: UNT Libraries Government Documents Department

Detecting Distributed Scans Using High-Performance Query-DrivenVisualization

Description: Modern forensic analytics applications, like network trafficanalysis, perform high-performance hypothesis testing, knowledgediscovery and data mining on very large datasets. One essential strategyto reduce the time required for these operations is to select only themost relevant data records for a given computation. In this paper, wepresent a set of parallel algorithms that demonstrate how an efficientselection mechanism -- bitmap indexing -- significantly speeds up acommon analysist ask, namely, computing conditional histogram on verylarge datasets. We present a thorough study of the performancecharacteristics of the parallel conditional histogram algorithms. Asacase study, we compute conditional histograms for detecting distributedscans hidden in a dataset consisting of approximately 2.5 billion networkconnection records. We show that these conditional histograms can becomputed on interactive timescale (i.e., in seconds). We also show how toprogressively modify the selection criteria to narrow the analysis andfind the sources of the distributed scans.
Date: September 1, 2006
Creator: Stockinger, Kurt; Bethel, E. Wes; Campbell, Scott; Dart, Eli & Wu,Kesheng
Partner: UNT Libraries Government Documents Department

Scale dependency of the effective matrix diffusion coefficient

Description: It has been recognized that matrix diffusion is an important process for retarding solute transport in fractured rock. Based on analyses of tracer transport data from a number of field tests, we demonstrate for the first time that the effective matrix-diffusion coefficient may be scale dependent and generally increases with test scale. A preliminary theoretical explanation of this scale dependency is also presented, based on the hypothesis that solute travel paths within a fracture network are fractals.
Date: May 30, 2003
Creator: Liu, H. H.; Bodvarsson, G. S. & Zhang, G.
Partner: UNT Libraries Government Documents Department

Annual Report for Environmental Management Science Program Project Number 86598 Coupled Flow and Reactivity in Variably Saturated Porous Media

Description: Improved models of contaminant migration in heterogeneous, variably saturated porous media are required to better define the long-term stewardship requirements for U.S. Department of Energy (DOE) lands and to assist in the design of effective vadose zone barriers to contaminant migrations. The objective of our three-year project is to meet the DOE need by developing new experimental approaches to describe adsorption and transport of contaminants in heterogeneous, variably saturated media (i.e., the vadose zone). The research specifically addresses the behavior of strontium, a high priority DOE contaminant. However, the key benefit of this research is improved conceptual models of how all contaminants migrate through heterogeneous, variably-saturated, porous media. Research activities are driven by the hypothesis that the reactivity of variably saturated porous media is dependent on the moisture content of the medium and can be represented by a relatively simple function applicable over a range of scales, contaminants, and media. A key and novel aspect of our research is the use of the 2-meter radius geocentrifuge capabilities at the Idaho National Engineering and Environmental Laboratory (INEEL) to conduct unsaturated reactive transport experiments (Figure 1). The experimental approach using the geocentrifuge provides data in a much shorter time period than conventional methods allowing us to complete more experiments and explore a wider range of moisture contents. The vadose zone research being done in this project will demonstrate the utility of environmental geocentrifuge experimental approaches and their applicability to DOE's vadose research needs.
Date: June 13, 2003
Creator: Palmer, Carl D.; Mattson, Earl D. & Smith, Robert W.
Partner: UNT Libraries Government Documents Department

Annual Report for Environmental Management Science Program Project Number 86598 Coupled Flow and Reactivity in Variably Saturated Porous Media

Description: Improved models of contaminant migration in heterogeneous, variably saturated porous media are required to better define the long-term stewardship requirements for U.S. Department of Energy (DOE) lands and to assist in the design of effective vadose zone barriers to contaminant migrations. The objective of our three-year project is to meet the DOE need by developing new experimental approaches to describe adsorption and transport of contaminants in heterogeneous, variably saturated media (i.e., the vadose zone). The research specifically addresses the behavior of strontium, a high priority DOE contaminant. However, the key benefit of this research is improved conceptual models of how all contaminants migrate through heterogeneous, variably-saturated, porous media. Research activities are driven by the hypothesis that the reactivity of variably saturated porous media is dependent on the moisture content of the medium and can be represented by a relatively simple function applicable over a range of scales, contaminants, and media. A key and novel aspect of our research is the use of the 2-meter radius geocentrifuge capabilities at the Idaho National Engineering and Environmental Laboratory (INEEL) to conduct unsaturated reactive transport experiments (Figure 1). The experimental approach using the geocentrifuge provides data in a much shorter time period than conventional methods allowing us to complete more experiments and explore a wider range of moisture contents. The vadose zone research being done in this project will demonstrate the utility of environmental geocentrifuge experimental approaches and their applicability to DOE's vadose research needs. This report summarizes our progress as of June 2003 in the first year of a three-year project.
Date: June 1, 2003
Creator: Palmer, Carl D.; Mattson, Earl D. & Smith, Robert W.
Partner: UNT Libraries Government Documents Department

An Analysis of Thirty Border Standard Metropolitan Statistical Areas in Relation to E. W. Burgess' Concentric Zone Hypothesis

Description: This study is made to evaluate some of these forces for the thirty titled Standard Metropolitan Statistical Areas of the United States which are located on and overlap borders of two or more states. The attempt is made to determine if border SMSAs conform to the Burgess model despite state lines and other barriers imposed between SMSA parts, or whether such barriers restrict functional growth to the state side containing the central city.
Date: June 1970
Creator: Bonner, Austin
Partner: UNT Libraries