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Tissue architecture and function: dynamic reciprocity via extra- and intra-cellular matrices (open access)

Tissue architecture and function: dynamic reciprocity via extra- and intra-cellular matrices

Mammary gland development, functional differentiation, and homeostasis are orchestrated and sustained by a balance of biochemical and biophysical cues from the organ's microenvironment. The three-dimensional microenvironment of the mammary gland, predominantly 'encoded' by a collaboration between the extracellular matrix (ECM), hormones, and growth factors, sends signals from ECM receptors through the cytoskeletal intracellular matrix to nuclear and chromatin structures resulting in gene expression; the ECM in turn is regulated and remodeled by signals from the nucleus. In this chapter, we discuss how coordinated ECM deposition and remodeling is necessary for mammary gland development, how the ECM provides structural and biochemical cues necessary for tissue-specific function, and the role of the cytoskeleton in mediating the extra - to intracellular dialogue occurring between the nucleus and the microenvironment. When operating normally, the cytoskeletal-mediated dynamic and reciprocal integration of tissue architecture and function directs mammary gland development, tissue polarity, and ultimately, tissue-specific gene expression. Cancer occurs when these dynamic interactions go awry for an extended time.
Date: December 23, 2008
Creator: Xu, Ren; Boudreau, Aaron & Bissell, Mina J
System: The UNT Digital Library
Extracellular matrix control of mammary gland morphogenesis and tumorigenesis: insights from imaging (open access)

Extracellular matrix control of mammary gland morphogenesis and tumorigenesis: insights from imaging

The extracellular matrix (ECM), once thought to solely provide physical support to a tissue, is a key component of a cell's microenvironment responsible for directing cell fate and maintaining tissue specificity. It stands to reason, then, that changes in the ECM itself or in how signals from the ECM are presented to or interpreted by cells can disrupt tissue organization; the latter is a necessary step for malignant progression. In this review, we elaborate on this concept using the mammary gland as an example. We describe how the ECM directs mammary gland formation and function, and discuss how a cell's inability to interpret these signals - whether as a result of genetic insults or physicochemical alterations in the ECM - disorganizes the gland and promotes malignancy. By restoring context and forcing cells to properly interpret these native signals, aberrant behavior can be quelled and organization re-established. Traditional imaging approaches have been a key complement to the standard biochemical, molecular, and cell biology approaches used in these studies. Utilizing imaging modalities with enhanced spatial resolution in live tissues may uncover additional means by which the ECM regulates tissue structure, on different length scales, through its pericellular organization (short-scale) and by biasing …
Date: October 23, 2008
Creator: Ghajar, Cyrus M & Bissell, Mina J
System: The UNT Digital Library
[Dallas Voice Soundout Article] (open access)

[Dallas Voice Soundout Article]

Article in the Dallas Voice newsletter featuring a Q&A with Amy Deaton.
Date: May 23, 2008
Creator: Briscoe, Ben
System: The UNT Digital Library
Proceedings of the 30th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring (open access)

Proceedings of the 30th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring

These proceedings contain papers prepared for the 30th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 23-25 September, 2008 in Portsmouth, Virginia. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States’ capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 23, 2008
Creator: Wetovsky, Marv A; Aguilar-chang, Julio; Arrowsmith, Marie; Arrowsmith, Stephen; Baker, Diane; Begnaud, Michael et al.
System: The UNT Digital Library
A Heterobimetallic Complex With an Unsupported Uranium(III)-Aluminum(I) Bond: (CpSiMe3)3U-AlCp* (Cp* = C5Me5) (open access)

A Heterobimetallic Complex With an Unsupported Uranium(III)-Aluminum(I) Bond: (CpSiMe3)3U-AlCp* (Cp* = C5Me5)

The discovery of molecular metal-metal bonds has been of fundamental importance to the understanding of chemical bonding. For the actinides, examples of unsupported metal-metal bonds are relatively uncommon, consisting of Cp{sub 3}U-SnPh{sub 3}, and several actinide-transition metal complexes. Traditionally, bonding in the f-elements has been described as electrostatic; however, elucidating the degree of covalency is a subject of recent research. In carbon monoxide complexes of the trivalent uranium metallocenes, decreased {nu}{sub CO} values relative to free CO suggest that the U(III) atom acts as a {pi}-donor. Ephritikhine and coworkers have demonstrated that {pi}-accepting ligands can differentiate trivalent lanthanide and actinide ions, an effect that renders this chemistry of interest in the context of nuclear waste separation technology.
Date: July 23, 2008
Creator: Minasian, Stefan; Krinsky Ph.D., Jamin; Williams, Valerie & Arnold Ph.D., John
System: The UNT Digital Library
Atmospheric Plasma Deposition of Diamond-like Carbon Coatings (open access)

Atmospheric Plasma Deposition of Diamond-like Carbon Coatings

There is great demand for thin functional coatings in the semiconductor, optics, electronics, medical, automotive and aerospace industries [1-13]. As fabricated components become smaller and more complex, the properties of the materials’ surface take on greater importance. Thin coatings play a key role in tailoring surfaces to give them the desired hardness, wear resistance, chemical inertness, and electrical characteristics. Diamond-like carbon (DLC) coatings possess an array of desirable properties, including outstanding abrasion and wear resistance, chemical inertness, hardness, a low coefficient of friction and exceptionally high dielectric strength [14-22]. Diamond-like carbon is considered to be an amorphous material, containing a mixture of sp2 and sp3 bonded carbon. Based on the percentage of sp3 carbon and the hydrogen content, four different types of DLC coatings have been identified: tetrahedral carbon (ta-C), hydrogenated amorphous carbon (a-C:H) hard, a-C:H soft, and hydrogenated tetrahedral carbon (ta-C:H) [20,24,25]. Possessing the highest hardness of 80 GPa, ta-C possesses an sp3 carbon content of 80 to 88u%, and no appreciable hydrogen content whereas a-C:H soft possesses a hardness of less than 10 GPa, contains an sp3 carbon content of 60% and a hydrogen content between 30 to 50%. Methods used to deposit DLC coatings include ion beam …
Date: January 23, 2008
Creator: Ladwig, Angela
System: The UNT Digital Library
Coarse Grained Modeling of The Interface BetweenWater and Heterogeneous Surfaces (open access)

Coarse Grained Modeling of The Interface BetweenWater and Heterogeneous Surfaces

Using coarse grained models we investigate the behavior of water adjacent to an extended hydrophobic surface peppered with various fractions of hydrophilic patches of different sizes. We study the spatial dependence of the mean interface height, the solvent density fluctuations related to drying the patchy substrate, and the spatial dependence of interfacial fluctuations. We find that adding small uniform attractive interactions between the substrate and solvent cause the mean position of the interface to be very close to the substrate. Nevertheless, the interfacial fluctuations are large and spatially heterogeneous in response to the underlying patchy substrate. We discuss the implications of these findings to the assembly of heterogeneous surfaces.
Date: June 23, 2008
Creator: Willard, Adam & Chandler, David
System: The UNT Digital Library
Seasonally Resolved Surface Water (delta)14C Variability in the Lombok Strait: A Coralline Perspective (open access)

Seasonally Resolved Surface Water (delta)14C Variability in the Lombok Strait: A Coralline Perspective

We have explored surface water mixing in the Lombok Strait through a {approx}bimonthly resolved surface water {Delta}{sup 14}C time-series reconstructed from a coral in the Lombok Strait that spans 1937 through 1990. The prebomb surface water {Delta}{sup 14}C average is -60.5{per_thousand} and individual samples range from -72{per_thousand} to 134{per_thousand}. The annual average post-bomb maximum occurs in 1973 and is 122{per_thousand}. The timing of the post-bomb maximum is consistent with a primary subtropical source for the surface waters in the Indonesian Seas. During the post-bomb period the coral records regular seasonal cycles of 5-20{per_thousand}. Seasonal high {Delta}{sup 14}C occur during March-May (warm, low salinity), and low {Delta}{sup 14}C occur in September (cool, higher salinity). The {Delta}{sup 14}C seasonality is coherent and in phase with the seasonal {Delta}{sup 14}C cycle observed in Makassar Strait. We estimate the influence of high {Delta}{sup 14}C Makassar Strait (North Pacific) water flowing through the Lombok Strait using a two endmember mixing model and the seasonal extremes observed at the two sites. The percentage of Makassar Strait water varies between 16 and 70%, and between 1955 and 1990 it averages 40%. During La Nina events there is a higher percentage of Makassar Strait (high {Delta}{sup 14}C) water …
Date: April 23, 2008
Creator: Guilderson, T. P.; Fallon, S. J.; Moore, M. D.; Schrag, D. P. & Charles, C. D.
System: The UNT Digital Library
Target life time of laser ion source for low charge state ion production (open access)

Target life time of laser ion source for low charge state ion production

Laser ion source (LIS) produces ions by irradiating pulsed high power laser shots onto the solid state target. For the low charge state ion production, laser spot diameter on the target can be over several millimeters using a high power laser such as Nd:YAG laser. In this case, a damage to the target surface is small while there is a visible crater in case of the best focused laser shot for high charge state ion production (laser spot diameter can be several tens of micrometers). So the need of target displacement after each laser shot to use fresh surface to stabilize plasma is not required for low charge state ion production. We tested target lifetime using Nd:YAG laser with 5 Hz repetition rate. Also target temperature and vacuum condition were recorded during experiment. The feasibility of a long time operation was verified.
Date: June 23, 2008
Creator: Kanesue,T.; Tamura, J. & Okamura, M.
System: The UNT Digital Library
The effect of head-on beam-beam compensation on the stochastic boundaries and particle diffusion in RHIC. (open access)

The effect of head-on beam-beam compensation on the stochastic boundaries and particle diffusion in RHIC.

To compensate the effects from the head-on beam-beam interactions in the polarized proton operation in the Relativistic Heavy Ion Collider (RHIC), an electron lens (elens) is proposed to collide head-on with the proton beam. We used an extended version of SixTrack for multiparticle beam-beam simulation in order to study the effect of the e-lens on the stochastic boundary and also on diffusion. The stochastic boundary was analyzed using Lyapunov exponents and the diffusion was characterized as the increase in the rms spread of the action. For both studies the simulations were performed with and without the e-lens and with full and partial compensation. Using the simulated values of the diffusion an attempt to calculate the emittance growth rate is presented.
Date: June 23, 2008
Creator: Abreu,N.; Beebe-Wang, J.; FischW; Luo, Y. & Robert-Demolaize, G.
System: The UNT Digital Library
An Experimental Study of Radiation-Induced Demagnetization of Insertion Device Permanent Magnets (open access)

An Experimental Study of Radiation-Induced Demagnetization of Insertion Device Permanent Magnets

High brilliance in the 3GeV new light source NSLS II is obtained from the high magnetic fields in insertion devices (ID). The beam lifetime is limited to 3h by single Coulomb scattering in the Bunch (Touschek effect). This effect occurs everywhere around the circumference and there is unavoidable beam loss in the adjacent low aperture insertion devices. This raises the issue of degradation and damage of the permanent magnetic material by irradiation with high energy electrons and corresponding shower particles. It is expected that IDs, especially those in-vacuum, would experience changes resulting from exposure to gamma rays, x-rays, electrons and neutrons. By expanding an on-going material radiation damage study at BNL the demagnetization effect of irradiation consisting primarily of neutrons, gamma rays and electrons on a set of NdFeB magnets is studied. Integrated doses ranging from several Mrad to a few Grad were achieved at the BNL Isotope Facility with a 112 MeV, 90 {micro}A proton beam. Detailed information on dose distributions as well as on particle energy spectra on the NdFeB magnets was obtained in realistic simulations with the MARS15 Monte-Carlo code. This paper summarizes the results of this study.
Date: June 23, 2008
Creator: Simos,N.; Job, P.K. & Mokhov, N.
System: The UNT Digital Library
Status of the NSLS-II Injection System Design (open access)

Status of the NSLS-II Injection System Design

The NSLS-II is a new ultra-bright 3rd generation 3 GeV light source that will be built at Brookhaven National Laboratory. Its design is well under way. The requirements for the compact injector complex, which will continuously provide 3 GeV electrons for top-off injection into the storage ring, are demanding: high reliability, relatively high charge and low losses. The injector consists of a linear accelerator, a full-energy booster, as well as transport lines, and an injection straight section. In this paper we give an overview of the NSLS-II injector, discuss its status, specifications, and the design challenges.
Date: June 23, 2008
Creator: Shaftan,T.
System: The UNT Digital Library
High-intensity polarized H-(proton), deuteron and 3He++ion source development at BNL. (open access)

High-intensity polarized H-(proton), deuteron and 3He++ion source development at BNL.

New techniques for the production of polarized electron, H{sup -} (proton), D (D+) and {sup 3}H{sup ++} ion beams are discussed. Feasibility studies of these techniques are in progress at BNL. An Optically Pumped Polarized H{sup -} Ion Source (OPPIS) delivers beam for polarization studies in RHIC. The polarized deuteron beam will be required for the deuteron Electron Dipole Moment (EDM) experiment, and the {sup 3}H{sup ++} ion beam is a part of the experimental program for the future eRHIC (Electron Ion) collider.
Date: June 23, 2008
Creator: Zelenski,A.
System: The UNT Digital Library
Setup and performance of RHIC for the 2008 run with deuteron-gold collisions. (open access)

Setup and performance of RHIC for the 2008 run with deuteron-gold collisions.

This year (2008) deuterons and gold ions were collided in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) for the first time since 2003. The setup and performance of the collider for the 2008 run is reviewed with a focus on improvements that have led to an order of magnitude increase in luminosity over that achieved in the 2003 run.
Date: June 23, 2008
Creator: Gardner,C.; Abreu, N.P.; Ahren, L.; Alessi, J.; Bai, M. & al., et
System: The UNT Digital Library
Benchmarking of collimation tracking using RHIC beam loss data. (open access)

Benchmarking of collimation tracking using RHIC beam loss data.

State-of-the-art tracking tools were recently developed at CERN to study the cleaning efficiency of the Large Hadron Collider (LHC) collimation system. In order to estimate the prediction accuracy of these tools, benchmarking studies can be performed using actual beam loss measurements from a machine that already uses a similar multistage collimation system. This paper reviews the main results from benchmarking studies performed with specific data collected from operations at the Relativistic Heavy Ion Collider (RHIC).
Date: June 23, 2008
Creator: Robert-Demolaize,G. & Drees, A.
System: The UNT Digital Library
Uncoupled achromatic tilted S-bend (open access)

Uncoupled achromatic tilted S-bend

A particular section of the electron beam transport line, to be used in the e-cooling project [l] of the Relativistic Heavy Ion Collider (RHIC), is constrained to displace the trajectory with both horizontal and vertical offsets so that the outgoing beamline is parallel to the incoming beamline. We also require that section be achromatic in both planes. This mixed horizontal and vertical achromatic Sbend is accomplished by rotating the two dipoles and the quadrupoles of the line, about the longitudinal axis of the incoming beam. However such a rotation of the magnetic elements may couple the transported beam through the first order beam transfer matrix (linear coupling). In this paper we study a sufficient condition, that the first order transport matrix (R-matrix) can satisfy, so that this section of beam transfer line is both achromatic and linearly uncoupled. We provide a complete solution for the beam optics which satisfies both conditions.
Date: June 23, 2008
Creator: Tsoupas, N.; Kayran, D.; Litvinenko, V. & MacKay, W. W.
System: The UNT Digital Library
Multiple-code simulation study of the long-term EDZ evolution of geological nuclear waste repositories (open access)

Multiple-code simulation study of the long-term EDZ evolution of geological nuclear waste repositories

This simulation study shows how widely different model approaches can be adapted to model the evolution of the excavation disturbed zone (EDZ) around a heated nuclear waste emplacement drift in fractured rock. The study includes modeling of coupled thermal-hydrological-mechanical (THM) processes, with simplified consideration of chemical coupling in terms of time-dependent strength degradation or subcritical crack growth. The different model approaches applied in this study include boundary element, finite element, finite difference, particle mechanics, and elastoplastic cellular automata methods. The simulation results indicate that thermally induced differential stresses near the top of the emplacement drift may cause progressive failure and permeability changes during the first 100 years (i.e., after emplacement and drift closure). Moreover, the results indicate that time-dependent mechanical changes may play only a small role during the first 100 years of increasing temperature and thermal stress, whereas such time-dependency is insignificant after peak temperature, because decreasing thermal stress.
Date: October 23, 2008
Creator: Rutqvist, J.; Backstrom, A.; Chijimatsu, M.; Feng, X. T.; Pan, P. Z.; Hudson, J. et al.
System: The UNT Digital Library
Dipole magnet for use of RHIC EBIS HEBT line. (open access)

Dipole magnet for use of RHIC EBIS HEBT line.

Construction and magnetic field measurement of dipole magnets for RHIC-EBIS HEBT line have completed. These magnets will be used to guide highly charged ion beams ranging from proton to Uranium provided by a new injector toward the Booster ring in BNL. In this paper, overview of the magnetic design of the dipoles and results of magnetic field measurement are summarized.
Date: June 23, 2008
Creator: Kanesue,T.; Okamura, M.; Ritter, J. & Raparia, D.
System: The UNT Digital Library
Nb3Sn Quadrupoles in the LHC IR Phase I Upgrade (open access)

Nb3Sn Quadrupoles in the LHC IR Phase I Upgrade

After a number of years of operation at nominal parameters, the LHC will be upgraded for higher luminosity. This paper discusses the possibility of using a limited number of Nb{sub 3}Sn quadrupoles for hybrid optics layouts for the LHC Phase I luminosity upgrades with both NbTi and Nb{sub 3}Sn quadrupoles. Magnet parameters and issues related to using Nb{sub 3}Sn quadrupoles including aperture, gradient, magnetic length, field quality, operation margin, et cetera are discussed.
Date: June 23, 2008
Creator: Zlobin,A.; Johnstone, J.; Kashikhin, V.; Mokhov, N.; Rakhno, I.; deMaria, R. et al.
System: The UNT Digital Library
Reduced Basis Method for Nanodevices Simulation (open access)

Reduced Basis Method for Nanodevices Simulation

Ballistic transport simulation in nanodevices, which involves self-consistently solving a coupled Schrodinger-Poisson system of equations, is usually computationally intensive. Here, we propose coupling the reduced basis method with the subband decomposition method to improve the overall efficiency of the simulation. By exploiting a posteriori error estimation procedure and greedy sampling algorithm, we are able to design an algorithm where the computational cost is reduced significantly. In addition, the computational cost only grows marginally with the number of grid points in the confined direction.
Date: May 23, 2008
Creator: Pau, George Shu Heng
System: The UNT Digital Library
Energy loss of coasting gold ions and deuterons in RHIC. (open access)

Energy loss of coasting gold ions and deuterons in RHIC.

The total energy loss of coasting gold ion beams was measured at RHIC at two energies, corresponding to a gamma of 75.2 and 107.4. We describe the experiment and observations and compare the measured total energy loss with expectations from ionization losses at the residual gas, the energy loss due to impedance and synchrotron radiation. We find that the measured energy losses are below what is expected from free space synchrotron radiation. We believe that this shows evidence for suppression of synchrotron radiation which is cut off at long wavelength by the presence of the conducting beam pipe.
Date: June 23, 2008
Creator: Abreu,N.; Blaskiewicz, M.; Brown, K.A.; Butler, J.J.; FischW; Harvey, M. et al.
System: The UNT Digital Library
RHIC polarized proton performance in run-8. (open access)

RHIC polarized proton performance in run-8.

During Run-8, the Relativistic Heavy Ion Collider (RHIC) provided collisions of spin-polarized proton beams at two interaction regions. Helical spin rotators at these two interaction regions were used to control the spin orientation of both beams at the collision points. Physics data were taken with different orientations of the beam polarization. We present recent developments and improvements as well as the luminosity and polarization performance achieved during Run-8.
Date: June 23, 2008
Creator: Montag, C.; Abreu, N.; Ahrens, L.; Bai, M.; Barton, D. & al., et
System: The UNT Digital Library
FEL-based coherent electron cooling for high-energy hadron colliders (open access)

FEL-based coherent electron cooling for high-energy hadron colliders

Cooling intense high-energy hadron beams is a major challenge in modern accelerator physics. Synchrotron radiation is too feeble and two common methods--stochastic and electron cooling--are not efficient in providing significant cooling for high energy, high intensity proton colliders. In this paper they discuss a practical scheme of Coherent Electron Cooling (CeC), which promises short cooling times (below one hour) for intense proton beams in RHIC at 250 GeV or in LHC at 7 TeV. A possibility of CeC using various microwave instabilities was discussed since 1980s. In this paper, they present first evaluation of specific CeC scheme based on capabilities of present-day accelerator technology, ERLs, and high-gain Free-Electron lasers (FELs). They discuss the principles, the main limitations of this scheme and present some predictions for Coherent Electron Cooling in RHIC and the LHC operating with ions or protons, summarized in Table 1.
Date: June 23, 2008
Creator: Litvinenko,V. N. & Derbenev, Y. S.
System: The UNT Digital Library
RHIC and its upgrade programmes. (open access)

RHIC and its upgrade programmes.

As the first hadron accelerator and collider consisting of two independent superconducting rings RHIC has operated with a wide range of beam energies and particle species. After a brief review of the achieved performance the presentation will give an overview of the plans, challenges and status of machine upgrades, that range from a new heavy ion pre-injector and beam cooling at 100 GeV to a high luminosity electron-ion collider.
Date: June 23, 2008
Creator: Roser, T.
System: The UNT Digital Library