CHARACTERIZATION OF ACTINIDES IN SIMULATED ALKALINE TANK WASTE SLUDGES AND LEACHATES (open access)

CHARACTERIZATION OF ACTINIDES IN SIMULATED ALKALINE TANK WASTE SLUDGES AND LEACHATES

In this project, both the fundamental chemistry of actinides in alkaline solutions (relevant to those present in Hanford-style waste storage tanks), and their dissolution from sludge simulants (and interactions with supernatants) have been investigated under representative sludge leaching procedures. The leaching protocols were designed to go beyond conventional alkaline sludge leaching limits, including the application of acidic leachants, oxidants and complexing agents. The simulant leaching studies confirm in most cases the basic premise that actinides will remain in the sludge during leaching with 2-3 M NaOH caustic leach solutions. However, they also confirm significant chances for increased mobility of actinides under oxidative leaching conditions. Thermodynamic data generated improves the general level of experiemental information available to predict actinide speciation in leach solutions. Additional information indicates that improved Al removal can be achieved with even dilute acid leaching and that acidic Al(NO3)3 solutions can be decontaminated of co-mobilized actinides using conventional separations methods. Both complexing agents and acidic leaching solutions have significant potential to improve the effectiveness of conventional alkaline leaching protocols. The prime objective of this program was to provide adequate insight into actinide behavior under these conditions to enable prudent decision making as tank waste treatment protocols develop.
Date: November 20, 2008
Creator: Nash, Kenneth L.
Object Type: Report
System: The UNT Digital Library
Effects of Heavy Ions on ULF Wave Resonances Near the Equatorial Region (open access)

Effects of Heavy Ions on ULF Wave Resonances Near the Equatorial Region

Pc1-2 ULF waves are strongly associated with the presence of various ions in the magnetosphere. We investigate the role of heavy ion resonances in nonuniform plasmas near the equatorial region. By adopting the invariant imbedding method, the coupled plasma wave equations are solved in an exact manner to calculate the resonant absorption at the ion-ion hybrid resonance. Our results show that irreversible mode conversion occurs at the resonance, which absorbs the fast wave energy. It is found that waves near the resonances appear with linear polarization, and their amplitude and frequency are sensitive to the properties of the heavy ion plasma composition. We examine how these resonances occur for various H+ - He+ populations in detail by performing an accurate calculation of the mode conversion effciency. Because the multi-ion hybrid resonance locations in cold plasmas are determined by simple parameters such as the fraction of the ion number density of each species and the magnetic field, we suggest that it is possible to monitor heavy ion composition by examining the peak frequencies of linearly polarized wave events in either electric field or magnetic field spectral data.
Date: November 20, 2008
Creator: D.-H.Lee, J.R. Johnson, K. Kim and K.-S.Kim
Object Type: Report
System: The UNT Digital Library
ELECTROCHEMICAL CORROSION TESTING OF TANKS 241-AN-102 & 241-AP-107 & 241-AP-108 IN SUPPORT OF ULTRASONIC TESTING (open access)

ELECTROCHEMICAL CORROSION TESTING OF TANKS 241-AN-102 & 241-AP-107 & 241-AP-108 IN SUPPORT OF ULTRASONIC TESTING

This report presents the results of the corrosion rates that were measured using electrochemical methods for tanks 241-AN-102 (AN-102), 241-AP-107 (AP 107), and 241-AP-108 (AP-108) performed under test plant RPP-PLAN-38215. The steel used as materials of construction for AN and AP tank farms was A537 Class 1. Test coupons of A537 Class 1 carbon steel were used for corrosion testing in the AN-107, AP-107, and AP-108 tank waste. Supernate will be tested from AN-102, AP-107, and Ap-108. Saltcake testing was performed on AP-108 only.
Date: November 20, 2008
Creator: RB, WYRWAS & JB, DUNCAN
Object Type: Report
System: The UNT Digital Library
Evaluation of Bull Trout Movements in the Tucannon and Lower Snake Rivers, 2002-2006 Project Completion Summary. (open access)

Evaluation of Bull Trout Movements in the Tucannon and Lower Snake Rivers, 2002-2006 Project Completion Summary.

The Columbia River Distinct Population Segment of bull trout (Salvelinus confluentus) was listed as threatened under the Endangered Species Act in 1998. One of the identified major threats to the species is fragmentation resulting from dams on over-wintering habitats of migratory subpopulations. A migratory subgroup in the Tucannon River appeared to utilize the Snake River reservoirs for adult rearing on a seasonal basis. As a result, a radio telemetry study was conducted on this subgroup from 2002-2006, to help meet Reasonable and Prudent Measures, and Conservation Recommendations associated with the lower Snake River dams in the FCRPS Biological Opinion, and to increase understanding of bull trout movements within the Tucannon River drainage. We sampled 1,109 bull trout in the Tucannon River; 124 of these were surgically implanted with radio tags and PIT tagged, and 681 were only PIT tagged. The remaining 304 fish were either recaptures, or released unmarked. Bull trout seasonal movements within the Tucannon River were similar to those described for other migratory bull trout populations. Bull trout migrated upstream in spring and early summer to the spawning areas in upper portions of the Tucannon River watershed. They quickly moved off the spawning areas in the fall, and …
Date: November 20, 2008
Creator: Faler, Michael P.; Mendel, Glen & Fulton, Carl
Object Type: Report
System: The UNT Digital Library
Evaluation of tropical cloud and precipitation statistics of CAM3 using CloudSat and CALIPSO data (open access)

Evaluation of tropical cloud and precipitation statistics of CAM3 using CloudSat and CALIPSO data

The combined CloudSat and CALIPSO satellite observations provide the first simultaneous measurements of cloud and precipitation vertical structure, and are used to examine the representation of tropical clouds and precipitation in the Community Atmosphere Model Version 3 (CAM3). A simulator package utilizing a model-to-satellite approach facilitates comparison of model simulations to observations, and a revised clustering method is used to sort the subgrid-scale patterns of clouds and precipitation into principal cloud regimes. Results from weather forecasts performed with CAM3 suggest that the model underestimates the horizontal extent of low and mid-level clouds in subsidence regions, but overestimates that of high clouds in ascending regions. CAM3 strongly overestimates the frequency of occurrence of the deep convection with heavy precipitation regime, but underestimates the horizontal extent of clouds and precipitation at low and middle levels when this regime occurs. This suggests that the model overestimates convective precipitation and underestimates stratiform precipitation consistent with a previous study that used only precipitation observations. Tropical cloud regimes are also evaluated in a different version of the model, CAM3.5, which uses a highly entraining plume in the parameterization of deep convection. While the frequency of occurrence of the deep convection with heavy precipitation regime from CAM3.5 …
Date: November 20, 2008
Creator: Zhang, Y.; Klein, S.; Boyle, J. & Mace, G. G.
Object Type: Article
System: The UNT Digital Library
Final Report for DE-FG02-96ER54370 (open access)

Final Report for DE-FG02-96ER54370

The work has consisted of three projects. The first one is a continuation of the previous work that was done on the generation of zonal flows due to the four wave modulational instability. In this work, we examined the growth of streamers. This work was done with undergraduate student, and was presented at an APS DPP meeting. A summary of the work is given below. Another project was a study of the stability of curvature driven modes with tied field line geometry. The purpose of this study was to see if this instability was relevant to the observed 'blob' phenomenon in the edge. A summary of this work is given starting in Section II. This work was done with undergraduate student. The final project was an extension of electrostatic work that had been done on the parallel velocity shear instability. In this work, we included electromagnetic effects. We performed the linear stability analysis and discovered a new regime of instability. This work was done in collaboration with undergraduate student, who presented the work at an APS DPP meeting. Details of this are shown in Section III.
Date: November 20, 2008
Creator: McCarthy, Daniel
Object Type: Report
System: The UNT Digital Library
July 2008 Monitoring Results for Barnes, Kansas. (open access)

July 2008 Monitoring Results for Barnes, Kansas.

The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility at Barnes, Kansas, during most of the interval 1949-1974. Carbon tetrachloride contamination was initially detected in 1986 in the town's public water supply wells. In 2006-2007, the CCC/USDA conducted a comprehensive targeted investigation at and near its former property in Barnes to characterize this contamination. Those results were reported previously (Argonne 2008a). In November 2007, the CCC/USDA began quarterly groundwater monitoring at Barnes. The monitoring is being conducted on behalf of the CCC/USDA by Argonne National Laboratory, in accord with the recommendations made in the report for the 2006-2007 targeted investigation (Argonne 2008a). The objective is to monitor the carbon tetrachloride contamination identified in the groundwater at Barnes. The sampling is presently conducted in a network of 28 individual monitoring wells (at 19 distinct locations), 2 public water supply wells, and 1 private well (Figure 1.1). The results of the 2006-2007 targeted investigation and the subsequent monitoring events in November 2007 (Argonne 2008b) and March 2008 (Argonne 2008c) demonstrated the presence of carbon tetrachloride contamination in groundwater at levels slightly exceeding the Kansas Department of Health and Environment (KDHE) Tier 2 risk-based screening level …
Date: November 20, 2008
Creator: LaFreniere, L. M.
Object Type: Report
System: The UNT Digital Library
Monitor and Evaluate the Genetic Characteristics of Supplemented Salmon and Steelhead, 2006-2007 Progress Report. (open access)

Monitor and Evaluate the Genetic Characteristics of Supplemented Salmon and Steelhead, 2006-2007 Progress Report.

This progress report offers a summary of genetic monitoring and evaluation research related to artificial propagation of Chinook salmon and steelhead in the Snake River basin. Our principal goal has been to characterize the relative (and net) reproductive success of hatchery fish spawning in the wild in multiple sub-basins. We address a critical uncertainty identified in essentially all tribal, state, and federal recovery planning efforts. Beyond simple description of those patterns of differential reproductive success, we seek to understand the biotic and abiotic factors that contribute to our observations, including genetic and environmental elements, and the real time effects of hatchery reform. We adopt two fundamentally different approaches that capture processes operating at different geographic scales. Our tier 2 design monitors changes in gene frequency through time in hatchery and wild populations. These studies monitor spatial and temporal genetic change over broad river basins and sub-basins. Tier 3 studies, by contrast, are able to construct pedigrees in naturally spawning populations that include hatchery and wild fish. We can then use actual matings to infer the fitness of hatchery versus wild individuals, based on the numbers of offspring we observe in our progeny samples. We get extraordinary detail from the tier …
Date: November 20, 2008
Creator: Berntson, Ewann; Waples, Robin S. & Moran, Paul
Object Type: Report
System: The UNT Digital Library
REPORT ON THE EFFECT OF TEMPERATURE AND AMMONIA CONCENTRATION ON A515 CARBON STEEL IN TANK 241 AY 101 SIMULANT (open access)

REPORT ON THE EFFECT OF TEMPERATURE AND AMMONIA CONCENTRATION ON A515 CARBON STEEL IN TANK 241 AY 101 SIMULANT

This report documents the results from RPP-PLAN-38676, Effect of Temperature and Ammonia Concentration on A515 Carbon Steel in Tank 241-AY-101 Simulant. The purpose of this test plan was to investigate the simulant formulated for the double-shell tank (DST) 241 AY 101 (AY 101) with the addition of ammonia. The simulant was formulated from the AY-101 condensate surface layer recipe used by CC Technologies{reg_sign} in the investigation of Hanford DST chemistry, under the Expert Panel on Corrosion. AY-101 is constructed from A515 grade 60 steel. The laboratory investigation used a cylindrical corrosion coupon from this steel formulation with a surface area of 5.64 square centimeters.
Date: November 20, 2008
Creator: JB, DUNCAN; DP, FRYE & RB, WYRWAS
Object Type: Report
System: The UNT Digital Library
A REPRINT of a July 1991 Report to Congress, Executive Summary of Verification of Nuclear Warhead Dismantlement and Special Nuclear Material Controls (open access)

A REPRINT of a July 1991 Report to Congress, Executive Summary of Verification of Nuclear Warhead Dismantlement and Special Nuclear Material Controls

With the renewed thinking and debate about deep reductions in nuclear weapons, including recent proposals about eliminating nuclear warheads altogether, republishing the general conclusions of the Robinson Committee Report of 1992 appears useful. The report is sometimes referred to as the 3151 Report, from Section 3151 of the National Defnse Authorization Act for FY1991, from where its requirement originated. This report contains the Executive Summary only and the forwarding letters from the Committee, the President of the United States, the Secretary of Energy, and C Paul Robinson, the head of the Advisory Committee.
Date: November 20, 2008
Creator: Fuller, James L.
Object Type: Report
System: The UNT Digital Library
Searle's"Dualism Revisited" (open access)

Searle's"Dualism Revisited"

A recent article in which John Searle claims to refute dualism is examined from a scientific perspective. John Searle begins his recent article 'Dualism Revisited' by stating his belief that the philosophical problem of consciousness has a scientific solution. He then claims to refute dualism. It is therefore appropriate to examine his arguments against dualism from a scientific perspective. Scientific physical theories contain two kinds of descriptions: (1) Descriptions of our empirical findings, expressed in an every-day language that allows us communicate to each other our sensory experiences pertaining to what we have done and what we have learned; and (2) Descriptions of a theoretical model, expressed in a mathematical language that allows us to communicate to each other certain ideas that exist in our mathematical imaginations, and that are believed to represent, within our streams of consciousness, certain aspects of reality that we deem to exist independently of their being perceived by any human observer. These two parts of our scientific description correspond to the two aspects of our general contemporary dualistic understanding of the total reality in which we are imbedded, namely the empirical-mental aspect and the theoretical-physical aspect. The duality question is whether this general dualistic understanding …
Date: November 20, 2008
Creator: P., Henry
Object Type: Article
System: The UNT Digital Library
Use of Helical Fields to Allow a Long Pulse Reversed Field Pinch (open access)

Use of Helical Fields to Allow a Long Pulse Reversed Field Pinch

The maintenance of the magnetic configuration of a Reversed Field Pinch (RFP) is an unsolved problem. Even a toroidal loop voltage does not suffice to maintain the magnetic configuration in axisymmetry but could if the plasma had helical shaping. The theoretical tools for plasma optimization using helical shaping have advanced, so an RFP could be relatively easily designed for optimal performance with a spatially constant toroidal loop voltage. A demonstration that interesting solutions exist is given.
Date: November 20, 2008
Creator: Boozer, A. & Pomphrey, N.
Object Type: Report
System: The UNT Digital Library
3-D Micro-Scale Machining Implementation (open access)

3-D Micro-Scale Machining Implementation

The KCP investigated milling, turning, and wire EDMing features at a micro-scale using existing equipment to find the limitations and hindrances to producing future designs.
Date: October 20, 2008
Creator: Boucher, Christopher L.
Object Type: Report
System: The UNT Digital Library
CMM Technology (open access)

CMM Technology

This project addressed coordinate measuring machine (CMM) technology and model-based engineering. CMM data analysis and delivery were enhanced through the addition of several machine types to the inspection summary program. CMM hardware and software improvements were made with the purchases of calibration and setup equipment and new model-based software for the creation of inspection programs. Kansas City Plant (KCP) personnel contributed to and influenced the development of dimensional metrology standards. Model-based engineering capabilities were expanded through the development of software for the tolerance analysis of piece parts and for the creation of model-based CMM inspection programs and inspection plans and through the purchase of off-the-shelf software for the tolerance analysis of mechanical assemblies. An obsolete database application used to track jobs in Precision Measurement was replaced by a web-based application with improved query and reporting capabilities. A potential project to address the transformation of the dimensional metrology enterprise at the Kansas City Plant was identified.
Date: October 20, 2008
Creator: Ward, Robert C.
Object Type: Report
System: The UNT Digital Library
Collective phenomena in non-central nuclear collisions (open access)

Collective phenomena in non-central nuclear collisions

Recent developments in the field of anisotropic flow in nuclear collision are reviewed. The results from the top AGS energy to the top RHIC energy are discussed with emphasis on techniques, interpretation, and uncertainties in the measurements.
Date: October 20, 2008
Creator: Voloshin, Sergei A.; Poskanzer, Arthur M. & Snellings, Raimond
Object Type: Book
System: The UNT Digital Library
Field Test Results of Automated Demand Response in a Large Office Building (open access)

Field Test Results of Automated Demand Response in a Large Office Building

Demand response (DR) is an emerging research field and an effective tool that improves grid reliability and prevents the price of electricity from rising, especially in deregulated markets. This paper introduces the definition of DR and Automated Demand Response (Auto-DR). It describes the Auto-DR technology utilized at a commercial building in the summer of 2006 and the methodologies to evaluate associated demand savings. On the basis of field tests in a large office building, Auto-DR is proven to be a reliable and credible resource that ensures a stable and economical operation of the power grid.
Date: October 20, 2008
Creator: Han, Junqiao; Piette, Mary Ann & Kiliccote, Sila
Object Type: Article
System: The UNT Digital Library
Grays River Watershed Restoration Status Report 2007, May 1, 2007 - October 30, 2008. (open access)

Grays River Watershed Restoration Status Report 2007, May 1, 2007 - October 30, 2008.

The Bonneville Power Administration (BPA) Project 2003-013-00, 'Grays River Watershed Restoration', began in FY04 and continues into FY09. This status report is intended to summarize accomplishments during the period 1 May 2007 through 30 October 2008. Accomplishments are summarized by Work Elements, as detailed in the Statement of Work (see BPA's project management database PISCES). The Pacific Northwest National Laboratory (PNNL) is collaborating with the Columbia River Estuary Task Force (CREST) on implementation of the Grays River Restoration Project. The Grays River is vitally important to the recovery of Lower Columbia River (LCR) chum salmon because it currently has the most viable population remaining in the LCR region. The Grays River watershed is also important to the recovery of salmon and steelhead in the LCR ecosystem. Today, numbers of naturally spawning salmon and steelhead have declined to levels far below historical numbers because of habitat limiting factors that include but are not limited to the lack of habitat connectivity, diversity, channel stability, riparian function and altered stream flow conditions. The objective of this project is to restore habitat-forming processes to enhance salmon and steelhead populations in the Grays River, following recommendations developed during the FY04-06 BPA-sponsored Grays River Watershed Assessment …
Date: October 20, 2008
Creator: Hanrahan, Tim
Object Type: Report
System: The UNT Digital Library
Interfacial Structures of Acidic and Basic Aqueous Solutions (open access)

Interfacial Structures of Acidic and Basic Aqueous Solutions

Phase-sensitive sum-frequency vibrational spectroscopy was used to study water/vapor interfaces of HCl, HI, and NaOH solutions. The measured imaginary part of the surface spectral responses provided direct characterization of OH stretch vibrations and information about net polar orientations of water species contributing to different regions of the spectrum. We found clear evidence that hydronium ions prefer to emerge at interfaces. Their OH stretches contribute to the 'ice-like' band in the spectrum. Their charges create a positive surface field that tends to reorient water molecules more loosely bonded to the topmost water layer with oxygen toward the interface, and thus enhances significantly the 'liquid-like' band in the spectrum. Iodine ions in solution also like to appear at the interface and alter the positive surface field by forming a narrow double-charge layer with hydronium ions. In NaOH solution, the observed weak change of the 'liquid-like' band and disappearance of the 'ice-like' band in the spectrum indicates that OH{sup -} ions must also have excess at the interface. How they are incorporated in the interfacial water structure is however not clear.
Date: October 20, 2008
Creator: Tian, C.; Ji, N.; Waychunas, G. & Shen, Y.R.
Object Type: Article
System: The UNT Digital Library
Laminin and biomimetic extracellular elasticity enhance functional differentiation in mammary epithelia (open access)

Laminin and biomimetic extracellular elasticity enhance functional differentiation in mammary epithelia

In the mammary gland, epithelial cells are embedded in a 'soft' environment and become functionally differentiated in culture when exposed to a laminin-rich extracellular matrix gel. Here, we define the processes by which mammary epithelial cells integrate biochemical and mechanical extracellular cues to maintain their differentiated phenotype. We used single cells cultured on top of gels in conditions permissive for {beta}-casein expression using atomic force microscopy to measure the elasticity of the cells and their underlying substrata. We found that maintenance of {beta}-casein expression required both laminin signalling and a 'soft' extracellular matrix, as is the case in normal tissues in vivo, and biomimetic intracellular elasticity, as is the case in primary mammary epithelial organoids. Conversely, two hallmarks of breast cancer development, stiffening of the extracellular matrix and loss of laminin signalling, led to the loss of {beta}-casein expression and non-biomimetic intracellular elasticity. Our data indicate that tissue-specific gene expression is controlled by both the tissues unique biochemical milieu and mechanical properties, processes involved in maintenance of tissue integrity and protection against tumorigenesis.
Date: October 20, 2008
Creator: Alcaraz, Jordi; Xu, Ren; Mori, Hidetoshi; Nelson, Celeste M.; Mroue, Rana; Spencer, Virginia A. et al.
Object Type: Article
System: The UNT Digital Library
Lattice Boltzmann simulation of solute transport in heterogeneous porous media with conduits to estimate macroscopic continuous time random walk model parameters (open access)

Lattice Boltzmann simulation of solute transport in heterogeneous porous media with conduits to estimate macroscopic continuous time random walk model parameters

Lattice Boltzmann models simulate solute transport in porous media traversed by conduits. Resulting solute breakthrough curves are fitted with Continuous Time Random Walk models. Porous media are simulated by damping flow inertia and, when the damping is large enough, a Darcy's Law solution instead of the Navier-Stokes solution normally provided by the lattice Boltzmann model is obtained. Anisotropic dispersion is incorporated using a direction-dependent relaxation time. Our particular interest is to simulate transport processes outside the applicability of the standard Advection-Dispersion Equation (ADE) including eddy mixing in conduits. The ADE fails to adequately fit any of these breakthrough curves.
Date: October 20, 2008
Creator: Anwar, S.; Cortis, A. & Sukop, M.
Object Type: Article
System: The UNT Digital Library
Light Hadron Physics at the B Factories (open access)

Light Hadron Physics at the B Factories

We report measurements of hadronic final states produced in e{sup +}e{sup -} annihilations from the BABAR and Belle experiments. In particular, we present cross sections measured in several different processes, including two-photon physics, Initial-State Radiation, and exclusive hadron productions at center-of-mass energies near 10.58 GeV. Results are compared with theoretical predictions.
Date: October 20, 2008
Creator: Li, Selina Z.
Object Type: Article
System: The UNT Digital Library
Lightning Arrestor Connectors Production Readiness (open access)

Lightning Arrestor Connectors Production Readiness

The Lightning Arrestor Connector (LAC), part “M”, presented opportunities to improve the processes used to fabricate LACs. The A## LACs were the first production LACs produced at the KCP, after the product was transferred from Pinnellas. The new LAC relied on the lessons learned from the A## LACs; however, additional improvements were needed to meet the required budget, yield, and schedule requirements. Improvement projects completed since 2001 include Hermetic Connector Sealing Improvement, Contact Assembly molding Improvement, development of a second vendor for LAC shells, general process improvement, tooling improvement, reduction of the LAC production cycle time, and documention of the LAC granule fabrication process. This report summarizes the accomplishments achieved in improving the LAC Production Readiness.
Date: October 20, 2008
Creator: Marten, Steve; Linder, Kim; Emmons, Jim; Gomez, Antonio; Hasam, Dawud & Maurer, Michelle
Object Type: Report
System: The UNT Digital Library
Measurement of Time-Dependent CP Asymmetry in B0 --> KS pi0 gamma Decays (open access)

Measurement of Time-Dependent CP Asymmetry in B0 --> KS pi0 gamma Decays

The authors measure the time-dependent CP asymmetry in B{sup 0} {yields} K{sub S}{sup 0}{pi}{sup 0}{gamma} decays for two regions of K{sub S}{sup 0}-{pi}{sup 0} invariant mass, m(K{sub S}{sup 0}{pi}{sup 0}), using the final BABAR data set of 467 x 10{sup 6} B{bar B} pairs collected at the PEP-II e{sup +}e{sup -} collider at SLAC. They find 339 {+-} 24 B{sup 0} {yields} K*{sup 0}{gamma} candidates and measure S{sub K*{gamma}} = -0.03 {+-} 0.29 {+-} 0.03 and C{sub K*{gamma}} = -0.14 {+-} 0.16 {+-} 0.03. In the range 1.1 < m(K{sub S}{sup 0}{pi}{sup 0}) < 1.8 GeV/c{sup 2} they find 133 {+-} 20 B{sup 0} {yields} K{sub S}{sup 0}{pi}{sup 0}{gamma} candidates and measure S{sub K{sub S}{sup 0}{pi}{sup 0}{gamma}} = -0.78 {+-} 0.59 {+-} 0.09 and C{sub K{sub S}{sup 0}{pi}{sup 0}{gamma}} = -0.36 {+-} 0.33 {+-} 0.04. The uncertainties are statistical and systematic, respectively.
Date: October 20, 2008
Creator: Aubert, Bernard; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E. et al.
Object Type: Article
System: The UNT Digital Library
Prognostic breast cancer signature identified from 3D culture model accurately predicts clinical outcome across independent datasets (open access)

Prognostic breast cancer signature identified from 3D culture model accurately predicts clinical outcome across independent datasets

One of the major tenets in breast cancer research is that early detection is vital for patient survival by increasing treatment options. To that end, we have previously used a novel unsupervised approach to identify a set of genes whose expression predicts prognosis of breast cancer patients. The predictive genes were selected in a well-defined three dimensional (3D) cell culture model of non-malignant human mammary epithelial cell morphogenesis as down-regulated during breast epithelial cell acinar formation and cell cycle arrest. Here we examine the ability of this gene signature (3D-signature) to predict prognosis in three independent breast cancer microarray datasets having 295, 286, and 118 samples, respectively. Our results show that the 3D-signature accurately predicts prognosis in three unrelated patient datasets. At 10 years, the probability of positive outcome was 52, 51, and 47 percent in the group with a poor-prognosis signature and 91, 75, and 71 percent in the group with a good-prognosis signature for the three datasets, respectively (Kaplan-Meier survival analysis, p<0.05). Hazard ratios for poor outcome were 5.5 (95% CI 3.0 to 12.2, p<0.0001), 2.4 (95% CI 1.6 to 3.6, p<0.0001) and 1.9 (95% CI 1.1 to 3.2, p = 0.016) and remained significant for the two …
Date: October 20, 2008
Creator: Martin, Katherine J.; Patrick, Denis R.; Bissell, Mina J. & Fournier, Marcia V.
Object Type: Article
System: The UNT Digital Library