Constellation-X (Con-X) will carry out two powerful and independent sets of tests of dark energy based on X-ray observations of galaxy clusters, providing comparable accuracy to other leading dark energy probes. The first group of tests will measure the absolute distances to clusters, primarily using measurements of the X-ray gas mass fraction in the largest, dynamically relaxed clusters, but with additional constraining power provided by follow-up observations of the Sunyaev-Zel'dovich (SZ) effect. As with supernovae studies, such data determine the transformation between redshift and true distance, d(z), allowing cosmic acceleration to be measured directly. The second, independent group of tests will use the exquisite spectroscopic capabilities of Con-X to determine scaling relations between X-ray observables and mass. Together with forthcoming X-ray and SZ cluster surveys, these data will help to constrain the growth of structure, which is also a strong function of cosmological parameters.

To create high energy density matter and fusion conditions, high-power drivers, such as lasers, ion beams, and x-ray drivers, are employed to heat targets with pulses short compared to hydro-motion. Both high energy density physics and ion-driven inertial fusion require the simultaneous transverse and longitudinal compression of an ion beam to achieve high intensities. We have previously studied the effects of plasma neutralization for transverse beam compression. The scaled experiment, the Neutralized Transport Experiment (NTX), demonstrated that an initially un-neutralized beam can be compressed transversely to {approx}1 mm radius when charge neutralization by background plasma electrons is provided. Here we report longitudinal compression of a velocity-tailored, intense, neutralized 25 mA K+ beam at 300 keV. The compression takes place in a 1-2 m drift section filled with plasma to provide space-charge neutralization. An induction cell produces a head-to-tail velocity tilt that longitudinally compresses the neutralized beam, enhances the beam peak current by a factor of 50 and produces a pulse duration of about 3 ns. The Physics of longitudinal compression, experimental procedure, and the results of the compression experiments are presented.

To understand how non-malignant human mammary epithelial cells (HMEC) transit from a disorganized proliferating to an organized growth arrested state, and to relate this process to the changes that occur in breast cancer, we studied gene expression changes in non-malignant HMEC grown in three-dimensional cultures, and in a previously published panel of microarray data for 295 breast cancer samples. We hypothesized that the gene expression pattern of organized and growth arrested mammary acini would share similarities with breast tumors with good prognoses. Using Affymetrix HG-U133A microarrays, we analyzed the expression of 22,283 gene transcripts in two HMEC cell lines, 184 (finite life span) and HMT3522 S1 (immortal non-malignant), on successive days post-seeding in a laminin-rich extracellular matrix assay. Both HMECs underwent growth arrest in G0/G1 and differentiated into polarized acini between days 5 and 7. We identified gene expression changes with the same temporal pattern in both lines. We show that genes that are significantly lower in the organized, growth arrested HMEC than in their proliferating counterparts can be used to classify breast cancer patients into poor and good prognosis groups with high accuracy. This study represents a novel unsupervised approach to identifying breast cancer markers that may be of …

The relative permeability to fluids in hydrate-bearing sediments is an important parameter for predicting natural gas production from gas hydrate reservoirs. We estimated the relative permeability parameters (van Genuchten alpha and m) in a hydrate-bearing sand by means of inverse modeling, which involved matching water saturation predictions with observations from a controlled waterflood experiment. We used x-ray computed tomography (CT) scanning to determine both the porosity and the hydrate and aqueous phase saturation distributions in the samples. X-ray CT images showed that hydrate and aqueous phase saturations are non-uniform, and that water flow focuses in regions of lower hydrate saturation. The relative permeability parameters were estimated at two locations in each sample. Differences between the estimated parameter sets at the two locations were attributed to heterogeneity in the hydrate saturation. Better estimates of the relative permeability parameters require further refinement of the experimental design, and better description of heterogeneity in the numerical inversions.

We extend the resummation of dimensionally-regulated amplitudes to next-to-next-to-leading poles. This requires the calculation of two-loop anomalous dimension matrices for color mixing through soft gluon exchange. Remarkably, we find that they are proportional to the corresponding one-loop matrices. Using the color generator notation, we reproduce the two-loop single-pole quantities H{sup (2)} introduced by Catani for quark and gluon elastic scattering. Our results also make possible threshold and a variety of other resummations at next-to-next-to leading logarithm. All of these considerations apply to 2 {yields} n processes with massless external lines.

The oxidation state distribution of Pu in each sample for each reaction time was measured using a combined ultrafiltration and solvent extraction technique (1-4). First the oxidation state distribution of aqueous Pu is measured. Then the total system (solid and aqueous phase combined) Pu oxidation state distribution is measured by lowering the pH to leach Pu from the solid phase. For each reaction time, a 2.5-mL aliquot of the aqueous phase was removed and passed through a 12-nm filter (Microsep 30K MWCO Centrifugal Device; Pall Corporation, East Hills, NY). An aliquot of the filtrate was removed to determine the aqueous phase Pu concentration, and oxidation state distribution in the remaining filtrate was measured using the parallel solvent extraction technique discussed.

A fine grained silicon-tungsten calorimeter is ideal for use as the electromagnetic calorimeter in a linear collider detector optimized for particle-flow reconstruction. We are designing a calorimeter that is based on readout chips which are bump bonded to the silicon wafers that serve as the active medium in the calorimeter. By using integrated electronics we plan to demonstrate that fine granularity can be achieved at a reasonable price. Our design minimizes the gap between tungsten layers leading to a small Moliere radius, an important figure of merit for particle-flow detectors. Tests of the silicon detectors to be used in a test beam prototype as well as timing measurements based on similar silicon detectors are discussed.

We review the recently developed bootstrap method for the computation of high-multiplicity QCD amplitudes at one loop. We illustrate the general algorithm step by step with a six-point example. The method combines (generalized) unitarity with on-shell recursion relations to determine the not cut-constructible, rational terms of these amplitudes. Our bootstrap approach works for arbitrary configurations of gluon helicities and arbitrary numbers of external legs.

We searched for redshifted O emission lines from the possible warm-hot intergalactic medium (WHIM) surrounding the cluster of galaxies A2218 at z = 0.1756 using the XIS instrument on Suzaku. This cluster is thought to have an elongated structure along the line of sight based on previous studies. We studied systematic uncertainties in the spectrum of the Galactic emission and in the soft X-ray response of the detectors due to the contamination building up on the XIS filters. We detected no significant redshifted O lines, and set a tight constraint on the intensity with upper limits for the surface brightness of O{sub VII} and O{sub VIII} lines of 1.1 x 10{sup -7} and 3.0 x 10{sup -7} photons cm{sup -2} s{sup -1} arcmin{sup -2}, respectively. These upper limits are significantly lower than the previously reported fluxes from the WHIM around other clusters of galaxies. We also discuss the prospect for the detection of the WHIM lines with Suzaku XIS in the future.

The Dubinin-Astashov (DA) isotherm parameters for U, Pu, Sr and Np have been updated to include additional data obtained since the original derivation. The DA isotherms were modified to include a kinetic function derived by Rahn to describe sorbate loading from the beginning of sorption up to steady state. The final functions describe both kinetic and thermodynamic sorption.

Resonance enhancement of the quantum efficiency of new polarized electron photocathodes based on a short-period strain-compensated AlInGaAs/GaAsP superlattice structure is reported. The superlattice is a part of an integrated Fabry-Perot optical cavity. We demonstrate that the Fabry-Perot resonator enhances the quantum efficiency by up to a factor 10 in the wavelength region of the main polarization maximum. The high structural quality implied by these results points to the very promising application of these photocathodes for spin-polarized electron sources.

Alloy 22 is a nickel base alloy highly resistant to all forms of corrosion. In very aggressive conditions (e.g. hot concentrated chloride containing brines) Alloy 22 could suffer localized attack, namely pitting and crevice corrosion. Chloride ion is known to be the most detrimental aggressive agent for Alloy 22 and is able to promote crevice corrosion when tight crevices exist in hot chloride containing solutions of different concentrations. Nitrate ion is an effective inhibitor of chloride induced crevice corrosion when present in a high enough [NO{sub 3}{sup -}]/[Cl{sup -}] ratio. The occurrence of localized corrosion in a given environment is governed by the values of the critical potential (E{sub crit}) for crevice corrosion and the corrosion potential (E{sub corr}) that the alloy may establish in the studied environment. If E{sub corr} is equal or higher than E{sub crit}, localized corrosion may be expected. This paper discusses the evolution of E{sub corr} and corrosion rate (CR) of Alloy 22 specimens in 18 m CaCl{sub 2} + 9 m Ca(NO{sub 3}){sub 2} and 18 m CaCl{sub 2} + 0.9 m Ca(NO{sub 3}){sub 2} brines at 155 C. Two types of specimens were used, polished as-welded (ASW) creviced and non-creviced specimens and as-welded …

The resistance of Alloy 22 (N06022) to localized corrosion, mainly crevice corrosion, has been extensively investigated in the last few years. However, the behavior of Alloy 22 in concentrated aqueous solutions that may simulate concentrated ground waters was not fully understood. Systematic electrochemical tests using cyclic potentiodynamic polarization as well as the Tsujikawa-Hisamatsu electrochemical method were performed to determine the crevice corrosion susceptibility of Alloy 22 in simulated concentrated water (SCW), simulated acidified water (SAW) and basic saturated water (BSW). Results show that Alloy 22 is immune to crevice corrosion in SCW and SAW but may suffer crevice corrosion initiation in BSW. Results also show that in a naturally aerated environment, the corrosion potential would never reach the critical potential for crevice corrosion initiation.

A Monte Carlo model has been developed for interrogation of fissionable material embedded in thick cargos when high-energy {beta}-delayed {gamma} rays are detected following neutron-induced fission. The model includes the principal structural components of the laboratory, the neutron source and collimator assembly in which it resides, the assembly that represents cargo of given characteristics, a target of highly-enriched uranium (HEU) and large external plastic scintillators for photon detection. The ability of this model to reproduce experimental measurements was tested by comparing simulations with measurements of the number of induced fissions and the number of detected photons when the HUE target was irradiated with 14.25-MeV neutrons in the absence of any cargo and while embedded in assemblies of plywood and iron pipes. The simulations agreed with experimental measurements within a factor of about 2 for irradiation of the bare target and when the areal density of intervening cargo was 33 g cm{sup -2} (wood) and 61 g cm{sup -2} (steel pipes). This suggests that the model can permit exploration of a large range in parameter space with reasonable fidelity.

We present a measurement of the velocity flow of the local universe relative to the CMB rest frame, based on the Jha, Riess & Kirshner (2007) sample of 133 low redshift type Ia supernovae. At a depth of 4500 km s{sup -1} we find a dipole amplitude of 279 {+-} 68 km s{sup -1} in the direction l = 285{sup o} {+-} 18{sup o}, b = -10{sup o} {+-} 15{sup o}, consistent with earlier measurements and with the assumption that the local velocity field is dominated by the Great Attractor region. At a larger depth of 5900 km s{sup -1} we find a shift in the dipole direction towards the Shapley concentration. We also present the first measurement of the quadrupole term in the local velocity flow at these depths. Finally, we have performed detailed studies based on N-body simulations of the expected precision with which the lowest multipoles in the velocity field can be measured out to redshifts of order 0.1. Our mock catalogues are in good agreement with current observations, and demonstrate that our results are robust with respect to assumptions about the influence of local environment on the type Ia supernova rate.

Photoemission of polarized electrons from heterostructures based on InAlGaAs/GaAs superlattices with minimum conduction-band offsets is investigated. The comparison of the excitation energy dependence of the photoemission polarization degree with the calculated spectra makes it possible to determine the polarization losses at different stages of the photoemission. A maximum polarization of P = 91% and a quantum efficiency of QE = 0.5% are close to the best results obtained for photocathodes that are based on strained semiconductor superlattices.

With the rising influence of the Gene On-tology, new approaches have emerged where the similarity between genes or gene products is obtained by comparing Gene Ontology code annotations associ-ated with them. So far, these approaches have solely relied on the knowledge en-coded in the Gene Ontology and the gene annotations associated with the Gene On-tology database. The goal of this paper is to demonstrate that improvements to these approaches can be obtained by integrating textual evidence extracted from relevant biomedical literature.

A key step in applying land surface parameterization schemes is to estimate model parameters that vary spatially and are unique to each computational element. Improved methods for parameter estimation (especially for parameters important to runoff response) are needed and require data from a wide range of climate regimes throughout the world. Accordingly, the GEWEX Hydrometeorology Panel (GHP) endorsed the concept of an international Model Parameter Estimation Project (MOPEX) at its Toronto meeting, August 1996. Phase I of MOPEX was funded by NOAA in FY 1997, Phase II in FY 2000 and Phase III in FY 2003. MOPEX was adopted as projects of the IAHS/WMO Committee on GEWEX and of the WMO Commission on Hydrology (CHy) and now is a contributor to the Combine Enhanced Observing Period (CEOP) of the World Climate Research Program (WCRP). In 2004 MOPEX became a Working Group of the IAHS Prediction for Ungaged Basins (PUB) Initiative. MOPEX also is expected to contribute to the work of the Hydrologic Ensemble Prediction Experiment (HEPEX) (Franz et al, 2005). The primary goal of MOPEX is to develop techniques for the a priori estimation of the parameters used in land surface parameterization schemes of atmospheric models and in hydrologic models. …

In a first beam dynamics validation experiment for a new Pulse Line Ion Acceleration (PLIA) concept, the predicted energy amplification and beam bunching were experimentally observed. Beam energy modulation of -80 keV to +150 keV was measured using a PLIA input voltage waveform of -21 kV to +12 kV. Ion pulses accelerated by 150 keV, and bunching by a factor of four were simultaneously achieved. The measured longitudinal phase space and current waveform of the accelerated beam are in good agreement with 3-D particle-in-cell simulations.

We applied a 0.3 mJ, 1.7 ns, 46.9 nm soft X-ray Argon laser to ablate the surface of large band gap dielectrics: CaF{sub 2} and LiF crystals. The ablation versus the fluence of the soft X-ray beam has been studied varying the fluence in the range of 0.05-3 J/cm{sup 2}. An ablation threshold of 0.06 and 0.1 J/cm{sup 2} and an ablation depth of 14 and 20 nm have been found for CaF{sub 2} and LiF, respectively. These results define new ablation conditions for these large band gap dielectrics, which can be of interest for the fine processing of these materials.

Fano Effect measurements are the key to direct observation of the Kondo or spin shielding intrinsic to models of electron correlation. The Fano Effect is the observation of spin polarized photoelectron emission from NONMAGNETIC materials, under chirally selective excitation, such as circularly polarized photons. Below are described three spectrometers, with which Fano Effects measurements have been made.

Synchrotron radiation was used to directly observe the transformation of ferrite, austenite and sigma phases during heating and cooling of 2205 duplex stainless steel. Sigma formed during the initial stages of heating, dissolved as the temperature was increased, and reformed on cooling. The dissolution temperature of sigma was measured to be 985 C {+-} 2.8 C at a heating rate of 0.25 C/s, and the kinetics of sigma formation at 850 C was determined to be slower after dissolving at 1000 C than before.

The Model Parameter Estimation Experiment (MOPEX) is an international project aimed at developing enhanced techniques for the a priori estimation of parameters in hydrologic models and in land surface parameterization schemes connected to atmospheric models. The MOPEX science strategy involves: database creation, a priori parameter estimation methodology development, parameter refinement or calibration, and the demonstration of parameter transferability. A comprehensive MOPEX database has been developed that contains historical hydrometeorological data and land surface characteristics data for many hydrologic basins in the United States (US) and in other countries. This database is being continuously expanded to include basins from various hydroclimatic regimes throughout the world. MOPEX research has largely been driven by a series of international workshops that have brought interested hydrologists and land surface modelers together to exchange knowledge and experience in developing and applying parameter estimation techniques. With its focus on parameter estimation, MOPEX plays an important role in the international context of other initiatives such as GEWEX, PUB and PILPS. This paper outlines the MOPEX initiative, discusses its role in the scientific community and briefly states future directions.

The authors report the measurement of electron impact excitation cross sections for the strong iron L-shell 3 {yields} 2 lines of Fe XVIII through Fe XXIV at the EBIT-I electron beam ion trap using a crystal spectrometer and a 6 x 6 pixel array microcalorimeter. The cross sections were determined by direct normalization to the well established cross section of radiative electron capture through a sophisticated model analysis which results in the excitation cross section for 48 lines at multiple electron energies. They also studied the electron density dependent nature of the emission lines, which is demonstrated by the effective excitation cross section of the 3d {yields} 2p transition in Fe XXI.