Terascale simulations for heavy ion inertial fusion energy (open access)

Terascale simulations for heavy ion inertial fusion energy

The intense ion beams in a heavy ion Inertial Fusion Energy (IFE) driver and fusion chamber are non-neutral plasmas whose dynamics are largely dominated by space charge. We propose to develop a ''source-to-target'' Heavy Ion Fusion (HIF) beam simulation capability: a description of the kinetic behavior of this complex, nonlinear system which is both integrated and detailed. We will apply this new capability to further our understanding of key scientific issues in the physics of ion beams for IFE. The simulations will entail self-consistent field descriptions that require interprocessor communication, but are scalable and will run efficiently on terascale architectures. This new capability will be based on the integration of three types of simulations, each requiring terascale computing: (1) simulations of acceleration and confinement of the space-charge-dominated ion beams through the driver (accelerator, pulse compression line, and final focusing system) which accurately describe their dynamics, including emittance growth (phase-space dilution) effects; these are particle-in-cell (PIC) models; (2) electromagnetic (EM) and magnetoinductive (Darwin) simulations which describe the beam and the fusion chamber environment, including multibeam, neutralization, stripping, beam and plasma ionization processes, and return current effects; and (3) highly detailed simulations (6f, multispecies PIC, continuum Vlasov), which can examine electron effects …
Date: June 8, 2000
Creator: Friedman, A.; Cohen, R. H.; Grote, D. P.; Sharp, W. M.; Celata, C. M.; Lee, E. P. et al.
Object Type: Report
System: The UNT Digital Library
Laboratory Measurements of Velocity and Attenuation in Sediments (open access)

Laboratory Measurements of Velocity and Attenuation in Sediments

Laboratory measurements are required to establish relationships between the physical properties of unconsolidated sediments and P- and S-wave propagation through them. Previous work has either focused on measurements of compressional wave properties at depths greater than 500 m for oil industry applications or on measurements of dynamic shear properties at pressures corresponding to depths of less than 50 m for geotechnical applications. Therefore, the effects of lithology, fluid saturation, and compaction on impedance and P- and S-wave velocities of shallow soils are largely unknown. We describe two state-of-the-art laboratory experiments. One setup allows us to measure ultrasonic P-wave velocities at very low pressures in unconsolidated sediments (up to 0.1 MPa). The other experiment allows P- and S-wave velocity measurements at low to medium pressures (up to 20 MPa). We summarize the main velocity and attenuation results on sands and sand - clay mixtures under partially saturated and fully saturated conditions in two ranges of pressures (0 - 0.1 MPa and 0.1 - 20 MPa) representative of the top few meters and the top 1 km, respectively. Under hydrostatic pressures of 0.1 to 20 MPa, our measurements demonstrate a P- and S-wave velocity-dependence in dry sands around a fourth root (0.23 …
Date: June 8, 2004
Creator: Zimmer, M A; Berge, P A; Bonner, B P & Prasad, M
Object Type: Article
System: The UNT Digital Library
SCIENTIFIC PRESENTATIONS: 11TH MEETING OF THE MANAGEMENT STEERING COMMITTEE OF THE RIKEN BNL COLLABORATION (RBRC SCIENTIFIC ARTICLE, VOLUME 11) (open access)

SCIENTIFIC PRESENTATIONS: 11TH MEETING OF THE MANAGEMENT STEERING COMMITTEE OF THE RIKEN BNL COLLABORATION (RBRC SCIENTIFIC ARTICLE, VOLUME 11)

None
Date: June 8, 2005
Creator: SAMIOS, N. P. (ORGANIZER)
Object Type: Report
System: The UNT Digital Library
Fluorescent CdSe/ZnS Nanocrystal-Peptide Conjugates for Long-term, Nontoxic Imaging and Nuclear Targeting in Living Cells (open access)

Fluorescent CdSe/ZnS Nanocrystal-Peptide Conjugates for Long-term, Nontoxic Imaging and Nuclear Targeting in Living Cells

One of the biggest challenges in cell biology is the imaging of living cells. For this purpose, the most commonly used visualization tool is fluorescent markers. However, conventional labels, such as organic fluorescent dyes or green fluorescent proteins (GFP), lack the photostability to allow the tracking of cellular events that happen over minutes to days. In addition, they are either toxic to cells (dyes), or difficult to construct and manipulate (GFP). We report here the use of a new class of fluorescent labels, silanized CdSe/ZnS nanocrystal-peptide conjugates, for imaging the nuclei of living cells. CdSe/ZnS nanocrystals, or so called quantum dots (qdots), are extremely photostable, and have been used extensively in cellular imaging of fixed cells. Most of the studies about living cells so far have been concerned only with particle entry into the cytoplasm or the localization of receptors on the cell membrane. Specific targeting of qdots to the nucleus of living cells has not been reported in previous studies, due to the lack of a targeting mechanism and proper particle size. Here we demonstrate for the first time the construction of a CdSe/ZnS nanocrystal-peptide conjugate that carries the SV40 large T antigen nuclear localization signal (NLS), and the …
Date: June 8, 2004
Creator: Chen, F & Gerion, D
Object Type: Article
System: The UNT Digital Library
Phase Retrieval from Modulus Using Homeomorphic Signal Processing and the Complex Cepstrum: An Algorithm for Lightning Protection Systems (open access)

Phase Retrieval from Modulus Using Homeomorphic Signal Processing and the Complex Cepstrum: An Algorithm for Lightning Protection Systems

In general, the Phase Retrieval from Modulus problem is very difficult. In this report, we solve the difficult, but somewhat more tractable case in which we constrain the solution to a minimum phase reconstruction. We exploit the real-and imaginary part sufficiency properties of the Fourier and Hilbert Transforms of causal sequences to develop an algorithm for reconstructing spectral phase given only spectral modulus. The algorithm uses homeomorphic signal processing methods with the complex cepstrum. The formal problem of interest is: Given measurements of only the modulus {vert_bar}H(k){vert_bar} (no phase) of the Discrete Fourier Transform (DFT) of a real, finite-length, stable, causal time domain signal h(n), compute a minimum phase reconstruction {cflx h}(n) of the signal. Then compute the phase of {cflx h}(n) using a DFT, and exploit the result as an estimate of the phase of h(n). The development of the algorithm is quite involved, but the final algorithm and its implementation are very simple. This work was motivated by a Phase Retrieval from Modulus Problem that arose in LLNL Defense Sciences Engineering Division (DSED) projects in lightning protection for buildings. The measurements are limited to modulus-only spectra from a spectrum analyzer. However, it is desired to perform system identification …
Date: June 8, 2004
Creator: Clark, G A
Object Type: Report
System: The UNT Digital Library
Development of a Quantitative Approach to Incorporating Stakeholder Values into Total Maximum Daily Loads: Dominguez Channel Case Study (open access)

Development of a Quantitative Approach to Incorporating Stakeholder Values into Total Maximum Daily Loads: Dominguez Channel Case Study

The federal Clean Water Act (CWA) Section 303(d)(1)(A) requires each state to conduct a biennial assessment of its waters, and identify those waters that are not achieving water quality standards. The result of this assessment is called the 303(d) list. The CWA also requires states to establish a priority ranking for waters on the 303(d) list of impaired waters and to develop and implement Total Maximum Daily Loads (TMDLs) for these waters. Over 30,000 segments of waterways have been listed as impaired by the Environmental Protection Agency (EPA). The EPA has requested local communities to submit plans to reduce discharges by specified dates or have them developed by the EPA. An investigation of this process found that plans to reduce discharges were being developed based on a wide range of site investigation methods. The Department of Energy requested Lawrence Livermore National Laboratory to develop appropriate tools to assist in improving the TMDL process. The EPA has shown support and encouragement of this effort. Our investigation found that improving the stakeholder input process would facilitate many of the TMDL processes, given the resources available to the interested and responsible parties. The first model that we have developed is a stakeholder allocation …
Date: June 8, 2004
Creator: Stewart, J.
Object Type: Article
System: The UNT Digital Library
Groundwater Monitoring Plan for the 1301-N, 1324-N/NA, and 1325-N RCRA Facilities (open access)

Groundwater Monitoring Plan for the 1301-N, 1324-N/NA, and 1325-N RCRA Facilities

The 1301-N and 1325-N Liquid Waste Disposal Facilities, the 1324-N Surface Impoundment, and the 1324-NA Percolation Pond, located in the 100 N Area of the Hanford Site, are regulated under the Resource Conservation and Recovery Act of 1976 (RCRA). The closure plans for these facilities stipulate that groundwater is monitored according to the 100-N Pilot Project: Proposed Consolidated Groundwater Monitoring Program (BHI-00725). This document supplements the consolidated plan by providing information on sampling and analysis protocols, quality assurance, data management, and a conceptual model for the RCRA sites. Monitoring well networks, constituents, and sampling frequency remain the same as in the consolidated plan or the previous groundwater monitoring plan (Hartman 1996).
Date: June 8, 2002
Creator: Hartman, Mary J.
Object Type: Report
System: The UNT Digital Library
Radiation Driven Capsules for Fast Ignition (open access)

Radiation Driven Capsules for Fast Ignition

The energy required to ignite compressed deuterium-tritium fuel is a strong function of the fuel density. Through a series of detailed numerical simulations, peak fuel densities have been calculated as a function of the peak radiation drive temperature. Note that the time dependence of the radiation temperature (pulse shaping) has been optimized to obtain maximum density for each scaling point. A simple analytic scaling is developed, which agrees well with the numerical results. These scaling results are then used to obtain the required ignition energy as a function of peak drive temperature.
Date: June 8, 2001
Creator: Herrmann, M & Slutz, S A
Object Type: Article
System: The UNT Digital Library
Fatigue Testing of Abrasive Water Jet Cut Titanium (open access)

Fatigue Testing of Abrasive Water Jet Cut Titanium

Battelle Memorial Institute as part of its U.S. Department of Energy (USDOE) Contract No. DE-AC05-76RL01830 to operate the Pacific Northwest National Laboratory (PNNL) provides technology assistance to qualifying small businesses in association with a Technology Assistance Program (TAP). Qualifying companies are eligible to receive a set quantity of labor associated with specific technical assistance. Having applied for a TAP agreement to assist with fatigue characterization of Abrasive Water Jet (AWJ) cut titanium specimens, the OMAX Corporation was awarded TAP agreement 09-02. This program was specified to cover dynamic testing and analysis of fatigue specimens cut from titanium alloy Ti-6%Al-4%V via AWJ technologies. In association with the TAP agreement, a best effort agreement was made to characterize fatigue specimens based on test conditions supplied by OMAX.
Date: June 8, 2009
Creator: Hovanski, Yuri; Dahl, Michael E. & Williford, Ralph E.
Object Type: Report
System: The UNT Digital Library
Articles, Materials, and Supplies Manufactured Outside of U.S., Fiscal Year 2008 (open access)

Articles, Materials, and Supplies Manufactured Outside of U.S., Fiscal Year 2008

A letter sent to multiple people reporting on the status of the purchases of articles, materials, and supplies manufactured outside of the United States for Fiscal Year 2008.
Date: June 8, 2009
Creator: Milligan, Chris
Object Type: Letter
System: The UNT Digital Library
Crystallization Process of Protein Rv0731c from Mycobacterium Tuberculosis for a Successful Atomic Resolution Crystal Structure at 1.2 Angstrom (open access)

Crystallization Process of Protein Rv0731c from Mycobacterium Tuberculosis for a Successful Atomic Resolution Crystal Structure at 1.2 Angstrom

Proteins are bio-macromolecules consisting of basic 20 amino acids and have distinct three-dimensional folds. They are essential parts of organisms and participate in every process within cells. Proteins are crucial for human life, and each protein within the body has a specific function, such as antibodies, contractile proteins, enzymes, hormonal proteins, structural proteins, storage proteins and transport proteins. Determining three-dimensional structure of a protein can help researchers discover the remarkable protein folding, binding site, conformation and etc, in order to understand well of protein interaction and aid for possible drug design. The research on protein structure by X-ray protein crystallography carried by Li-Wei Hung's research group in the Physical Bioscience Division at Lawrence Berkeley National Laboratory (LBNL) is focusing on protein crystallography. The research in this lab is in the process of from crystallizing the proteins to determining the three dimensional crystal structures of proteins. Most protein targets are selected from Mycobacterium Tuberculosis. TB (Tuberculosis) is a possible fatal infectious disease. By studying TB target protein can help discover antituberculer drugs, and find treatment for TB. The high-throughput mode of crystallization, crystal harvesting, crystal screening and data collection are applied to the research pipeline (Figure 1). The X-ray diffraction data …
Date: June 8, 2009
Creator: Zhu, Liang Cong
Object Type: Article
System: The UNT Digital Library
Errata Sheet for the Closure Report for Corrective Action Unit 528 (open access)

Errata Sheet for the Closure Report for Corrective Action Unit 528

Errata sheet for DOE/NV--1165, "Closure Report for Corrective Action Unit 528: Polychlorinated Biphenyls Contamination, Nevada Test Site, Nevada," Revision 0
Date: June 8, 2009
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
R&D for a Soft X-Ray Free Electron Laser Facility (open access)

R&D for a Soft X-Ray Free Electron Laser Facility

Several recent reports have identified the scientific requirements for a future soft x-ray light source, and a high-repetition-rate free-electron laser (FEL) facility that is responsive to these requirements is now on the horizon. R&D in some critical areas is needed, however, to demonstrate technical performance, thus reducing technical risks and construction costs. Such a facility most likely will be based on a CW superconducting linear accelerator with beam supplied by a high-brightness, high-repetition-rate photocathode electron gun operating in CW mode, and on an array of FELs to which the accelerated beam is distributed, each operating at high repetition rate and with even pulse spacing. Dependent on experimental requirements, the individual FELs can be configured for either self-amplified spontaneous emission (SASE), seeded, or oscillator mode of operation, including the use of high-gain harmonic generation (HGHG), echo-enhanced harmonic generation (EEHG), harmonic cascade, or other configurations. In this White Paper we identify the overall accelerator R&D needs, and highlight the most important pre-construction R&D tasks required to value-engineer the design configuration and deliverables for such a facility. In Section 1.4 we identify the comprehensive R&D ultimately needed. We identify below the highest-priority requirements for understanding machine performance and reduce risk and costs at …
Date: June 8, 2009
Creator: Corlett, John; Attwood, David; Byrd, John; Denes, Peter; Falcone, Roger; Heimann, Phil et al.
Object Type: Report
System: The UNT Digital Library
Science & Technology Workshop Tank Waste Retrieval Technology Activities (open access)

Science & Technology Workshop Tank Waste Retrieval Technology Activities

None
Date: June 8, 2009
Creator: Saunders, S. A.
Object Type: Article
System: The UNT Digital Library
High Resolution/High Fidelity Seismic Imaging and Parameter Estimation for Geological Structure and Material Characterization (open access)

High Resolution/High Fidelity Seismic Imaging and Parameter Estimation for Geological Structure and Material Characterization

Our proposed work on high resolution/high fidelity seismic imaging focused on three general areas: (1) development of new, more efficient, wave-equation-based propagators and imaging conditions, (2) developments towards amplitude-preserving imaging in the local angle domain, in particular, imaging methods that allow us to estimate the reflection as a function of angle at a layer boundary, and (3) studies of wave inversion for local parameter estimation. In this report we summarize the results and progress we made during the project period. The report is divided into three parts, totaling 10 chapters. The first part is on resolution analysis and its relation to directional illumination analysis. The second part, which is composed of 6 chapters, is on the main theme of our work, the true-reflection imaging. True-reflection imaging is an advanced imaging technology which aims at keeping the image amplitude proportional to the reflection strength of the local reflectors or to obtain the reflection coefficient as function of reflection-angle. There are many factors which may influence the image amplitude, such as geometrical spreading, transmission loss, path absorption, acquisition aperture effect, etc. However, we can group these into two categories: one is the propagator effect (geometric spreading, path losses); the other is the …
Date: June 8, 2008
Creator: Wu, Ru-Shan & Xie, Xiao-Bi
Object Type: Report
System: The UNT Digital Library
ONGOING INVESTIGATION OF THE EFFECT THAT DRUGSTORE BEETLES HAVE ON CELOTEX ASSEMBLIES FOUND WITHIN RADIOACTIVE MATERIAL PACKAGINGS (open access)

ONGOING INVESTIGATION OF THE EFFECT THAT DRUGSTORE BEETLES HAVE ON CELOTEX ASSEMBLIES FOUND WITHIN RADIOACTIVE MATERIAL PACKAGINGS

During normal operations at the Department of Energy's Hanford Site in Hanford, WA, drugstore beetles were found within the fiberboard subassemblies of two 9975 Shipping Packages. The Department of Energy's Packaging Certification Program (EM-60) directed a thorough investigation to determine if the drugstore beetles were causing damage that would be detrimental to the safety performance of the Celotex. The Savannah River National Laboratory is continuing to conduct the investigation with entomological expertise being provided by Clemson University. The outcome from the investigation conducted over the previous year was that no discernible damage had been caused by the drugstore beetles. One of the two packages has been essentially untouched over the past year and has only been opened to visually inspect for additional damage. This paper will provide details and results of the ongoing investigation of that package.
Date: June 8, 2009
Creator: Loftin, B.
Object Type: Article
System: The UNT Digital Library
Phase Transition Signature Results from PHENIX (open access)

Phase Transition Signature Results from PHENIX

The PHENIX experiment has conducted searches for the QCD critical point with measurements of multiplicity fluctuations, transverse momentum fluctuations, event-by-event kaon-to-pion ratios, elliptic flow, and correlations. Measurements have been made in several collision systems as a function of centrality and transverse momentum. The results do not show significant evidence of critical behavior in the collision systems and energies studied, although several interesting features are discussed.
Date: June 8, 2009
Creator: Mitchell, J.e. & Collaboration, PHENIX
Object Type: Article
System: The UNT Digital Library
Potential luminosity improvement for low-energy RHIC operation with electron cooling (open access)

Potential luminosity improvement for low-energy RHIC operation with electron cooling

There is a strong interest in heavy-ion RHIC collisions in the energy range below the present RHIC injection energy, which is termed 'low-energy' operation. These collisions will help to answer one of the key questions in the field of QCD about the existence and location of a critical point on the QCD phase diagram. However, luminosity projections are relatively low for the lowest energy points of interest. Luminosity improvement can be provided with RHIC electron cooling at low beam energies. This report summarizes the expected luminosity improvements with electron cooling and various limitations.
Date: June 8, 2009
Creator: Fedotov,A.
Object Type: Article
System: The UNT Digital Library
Pipelining RDP Data to the "Taxomatic" - Final Report (open access)

Pipelining RDP Data to the "Taxomatic" - Final Report

Describes the development of a web-based tool for establishing and exploring prokaryotic taxonomies. The tool links to RDP-II data and is a a part of the RDP's web services.
Date: June 8, 2009
Creator: Lilburn, Timothy G.; Garrity, George M. & Cole, James R.
Object Type: Report
System: The UNT Digital Library
Establishing an IEZ at the K-25 Site With Realism - ANS 2008 Annual Meeting - June 8-12, 2008 Anaheim, CA (open access)

Establishing an IEZ at the K-25 Site With Realism - ANS 2008 Annual Meeting - June 8-12, 2008 Anaheim, CA

The requirement from ANSI/ANS-8.3 states: (1) a criticality alarm system meeting the requirements of this standard shall be installed in areas where personnel would be subject to an excessive radiation dose; and (2) excessive dose = any dose to personnel corresponding to an absorbed dose from neutrons and gamma rays equal to or greater than 0.12 Gy (12 rad) in free air. The requirement was misconstrued to imply that the Immediate Evaluation Zone (IEZ) had to cover out to 12 Rad of dose. This mis-interpretation prompted the following official clarification: The standard does not attempt to define the area that is to be evacuated, which is considered a management responsibility and outside the scope of this Standard. What we wanted was an IEZ that: (1) depended on the facility characteristics and hazards; (2) departed from the one 'Size' fits all mentality; (3) balanced the risk of a criticality with the risk of evacuating; and (4) was consistent with the emergency planning process. What they have is a facility that is a mile long; a facility that was falling down around them; a facility where workers are routinely in fall protection; and a facility where high noise is the normal condition. …
Date: June 8, 2008
Creator: Kimball, K.D.
Object Type: Article
System: The UNT Digital Library
Research Needs for Magnetic Fusion Energy Sciences. Report of the Research Needs Workshop (ReNeW) Bethesda, Maryland, June 8-12, 2009 (open access)

Research Needs for Magnetic Fusion Energy Sciences. Report of the Research Needs Workshop (ReNeW) Bethesda, Maryland, June 8-12, 2009

Nuclear fusion - the process that powers the sun - offers an environmentally benign, intrinsically safe energy source with an abundant supply of low-cost fuel. It is the focus of an international research program, including the ITE R fusion collaboration, which involves seven parties representing half the world's population. The realization of fusion power would change the economics and ecology of energy production as profoundly as petroleum exploitation did two centuries ago. The 21st century finds fusion research in a transformed landscape. The worldwide fusion community broadly agrees that the science has advanced to the point where an aggressive action plan, aimed at the remaining barriers to practical fusion energy, is warranted. At the same time, and largely because of its scientific advance, the program faces new challenges; above all it is challenged to demonstrate the timeliness of its promised benefits. In response to this changed landscape, the Office of Fusion Energy Sciences (OFES ) in the US Department of Energy commissioned a number of community-based studies of the key scientific and technical foci of magnetic fusion research. The Research Needs Workshop (ReNeW) for Magnetic Fusion Energy Sciences is a capstone to these studies. In the context of magnetic fusion …
Date: June 8, 2009
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Probing the Conformational Distributions of Sub-Persistence Length DNA (open access)

Probing the Conformational Distributions of Sub-Persistence Length DNA

We have measured the bending elasticity of short double-stranded DNA (dsDNA) chains through small-angle X-ray scattering from solutions of dsDNA-linked dimers of gold nanoparticles. This method, which does not require exertion of external forces or binding to a substrate, reports on the equilibrium distribution of bending fluctuations, not just an average value (as in ensemble FRET) or an extreme value (as in cyclization), and in principle provides a more robust data set for assessing the suitability of theoretical models. Our experimental results for dsDNA comprising 42-94 basepairs (bp) are consistent with a simple worm-like chain model of dsDNA elasticity, whose behavior we have determined from Monte Carlo simulations that explicitly represent nanoparticles and their alkane tethers. A persistence length of 50 nm (150 bp) gave a favorable comparison, consistent with the results of single-molecule force-extension experiments on much longer dsDNA chains, but in contrast to recent suggestions of enhanced flexibility at these length scales.
Date: June 8, 2009
Creator: Mastroianni, Alexander; Sivak, David; Geissler, Phillip & Alivisatos, Paul
Object Type: Article
System: The UNT Digital Library
Characterization and device performance of (AgCu)(InGa)Se2 absorber layers (open access)

Characterization and device performance of (AgCu)(InGa)Se2 absorber layers

The study of (AgCu)(InGa)Se2 absorber layers is of interest in that Ag-chalcopyrites exhibit both wider bandgaps and lower melting points than their Cu counterparts. (AgCu)(InGa)Se2 absorber layers were deposited over the composition range 0 < Ag/(Ag+Cu) < 1 and 0.3 < Ga/(In+Ga) < 1.0 using a variety of elemental co-evaporation processes. Films were found to be singlephase over the entire composition range, in contrast to prior studies. Devices with Ga content 0.3 < Ga/(In+Ga) <0.5 tolerated Ag incorporation up to Ag/(Ag+Cu) = 0.5 without appreciable performance loss. Ag-containing films with Ga/(In+Ga) = 0.8 showed improved device characteristics over Cu-only control samples, in particular a 30-40% increase in short-circuit current. An absorber layer with composition Ag/(Ag+Cu) = 0.75 and Ga/(In+Ga) = 0.8 yielded a device with VOC = 890 mV, JSC = 20.5mA/cm2, fill factor = 71.3%, and η = 13.0%.
Date: June 8, 2009
Creator: Hanket, Gregory; Boyle, Jonathan H. & Shafarman, William N.
Object Type: Article
System: The UNT Digital Library
Characterization of Sugar Insensitive (sis) Mutants of Arabidopsis (open access)

Characterization of Sugar Insensitive (sis) Mutants of Arabidopsis

Despite the fact that soluble sugar levels have been postulated to play an important role in the control of a wide variety of plant metabolic and developmental pathways, the mechanisms by which plants respond to soluble sugar levels remain poorly understood. Plant responses to soluble sugar levels are also important in bioenergy production, as plant sugar responses are believed to help regulate both carbon fixation and carbon partitioning. For example, accumulation of soluble sugars, such as sucrose and glucose, in source tissues leads to feedback inhibition of photosynthesis, thereby decreasing rates of carbon fixation. Soluble sugar levels can also affect sink strengths, affecting the rates of accumulation of carbon-based compounds into both particular molecular forms (e.g. carbohydrates versus lipids versus proteins) and particular plant organs and tissues. Mutants of Arabidopsis that are defective in the ability to respond to soluble sugar levels were isolated and used as tools to identify some of the factors involved in plant sugar response. These sugar insensitive (sis) mutants were isolated by screening mutagenized seeds for those that were able to germinate and develop relatively normal shoot systems on media containing 0.3 M glucose or 0.3 M sucrose. At these sugar concentrations, wild-type Arabidopsis germinate …
Date: June 8, 2009
Creator: Gibson, Susan I.
Object Type: Report
System: The UNT Digital Library