Use of chlorine-36 and other geochemical data to test a groundwater flow model for Yucca Mountain, Nevada

Defining the spatial distribution and timing of subsurface fluid percolation is one of the most important factors determining long term performance of the potential high-level radioactive waste repository at Yucca Mountain, Nevada. The nonwelded interval of the Paintbrush Group (PTn), which overlies most of the potential repository, has high matrix porosities and permeabilities and is mostly unfractured. The Exploratory Studies Facility (ESF) is a 8-km long, 7.6-m diameter, tunnel excavated beneath Yucca Mountain to the level of the potential repository horizon in order to provide access for characterization of these rocks. Several samples collected within the ESF have measured {sup 36}Cl/Cl ratios that record anthropogenic {sup 36}Cl (bomb-pulse {sup 36}Cl), indicating that at least some fraction of the water has traversed the overlying PTn in 40 years or less and that flow is not confined to the matrix of that unit. The presence of a fast path transmitting bomb-pulse {sup 36}Cl to depth appears to require the simultaneous presence of a structure (such as a fault) cutting the PTn and sufficiently high magnitude to surface infiltration to initiate and sustain at least a small component of fracture flow along the connected fracture path associated with the structure. The {sup 36}Cl data have been simulated using the flow and transport model FEHM in order to establish bounds on infiltration rates at the site and to provide greater confidence in the understanding of unsaturated flow processes at the site by showing consistency between the observed and simulated data sets. An analogous effort simulating the distribution of porewater chloride concentrations is providing an independent means for confirming the conceptual model

Effect of Systemic Matrix Metalloproteinase Inhibition on Periodontal Wound Repair: A Proof of Concept Trial

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141196/1/jper0441.pd

Pareto Law in a Kinetic Model of Market with Random Saving Propensity

We have numerically simulated the ideal-gas models of trading markets, where each agent is identified with a gas molecule and each trading as an elastic or money-conserving two-body collision. Unlike in the ideal gas, we introduce (quenched) saving propensity of the agents, distributed widely between the agents ($0 \le \lambda < 1$). The system remarkably self-organizes to a critical Pareto distribution of money $P(m) \sim m^{-(\nu + 1)}$ with $\nu \simeq 1$. We analyse the robustness (universality) of the distribution in the model. We also argue that although the fractional saving ingredient is a bit unnatural one in the context of gas models, our model is the simplest so far, showing self-organized criticality, and combines two century-old distributions: Gibbs (1901) and Pareto (1897) distributions.Comment: 5 pages RevTeX4, 6 eps figures, to be published in Physica A (2004

Distribution of fast hydrologic paths in the unsaturated zone at Yucca Mountain

Development and testing of conceptual flow and transport models for hydrologic systems are strengthened when natural environmental tracers are incorporated into the process. One such tracer is chlorine-36 ({sup 36}Cl, half-life, 301,000 years), a radioactive isotope produced in the atmosphere and carried underground with percolating groundwater. High concentrations of this isotope were also added to meteoric water during a period of global fallout from atmospheric testing of nuclear devices, primarily in the 1950s. This bomb-pulse signal has been used to test for the presence of fast transport paths in the unsaturated zone at Yucca Mountain and to provide the basis for a conceptual model for their distribution. Yucca Mountain is under investigation by the US Department of Energy as a potential site at which to host an underground high-level radioactive waste repository. Under wetter climatic conditions, fast-flow pathways will respond quickly to increases in infiltration and have the potential to become seeps in the tunnel drifts. The {sup 36}Cl data are also being used in numerical flow and transport models to establish lower bounds on infiltration rates, estimate ground water ages, and establish bounding values for hydrologic flow parameters governing fracture transport

Time Evolution of Unstable Particle Decay Seen with Finite Resolution

Time evolution of the decay process of unstable particles is investigated in field theory models. We first formulate how to renormalize the non-decay amplitude beyond perturbation theory and then discuss short-time behavior of very long-lived particles. Two different formalisms, one that does and one that does not, assume existence of the asymptotic field of unstable particles are considered. The non-decay amplitude is then calculated by introducing a finite time resolution of measurement, which makes it possible to discuss both renormalizable and non-renormalizable decay interaction including the nucleon decay. In ordinary circumstances the onset of the exponential decay law starts at times as early as at roughly the resolution time, but with an enhanced amplitude which may be measurable. It is confirmed that the short-time formula $1 - \Gamma t$ of the exponential decay law may be used to set limits on the nucleon decay rate in underground experiments. On the other hand, an exceptional example of S-wave decay of very small Q-value is found, which does not have the exponential period at all.Comment: 26 pages, LATEX file with 8 PS figure

Observation of hard scattering in photoproduction events with a large rapidity gap at HERA

Events with a large rapidity gap and total transverse energy greater than 5 GeV have been observed in quasi-real photoproduction at HERA with the ZEUS detector. The distribution of these events as a function of the $\gamma p$ centre of mass energy is consistent with diffractive scattering. For total transverse energies above 12 GeV, the hadronic final states show predominantly a two-jet structure with each jet having a transverse energy greater than 4 GeV. For the two-jet events, little energy flow is found outside the jets. This observation is consistent with the hard scattering of a quasi-real photon with a colourless object in the proton.Comment: 19 pages, latex, 4 figures appended as uuencoded fil

Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events

The $B^0$-$\bar B^0$ oscillation frequency has been measured with a sample of 23 million \B\bar B pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives $\Delta m_d = 0.493 \pm 0.012{(stat)}\pm 0.009{(syst)}$ ps$^{-1}$.Comment: 7 pages, 1 figure, submitted to Physical Review Letter

Observation of Orbitally Excited B_s Mesons

We report the first observation of two narrow resonances consistent with states of orbitally excited (L=1) B_s mesons using 1 fb^{-1} of ppbar collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. We use two-body decays into K^- and B^+ mesons reconstructed as B^+ \to J/\psi K^+, J/\psi \to \mu^+ \mu^- or B^+ \to \bar{D}^0 \pi^+, \bar{D}^0 \to K^+ \pi^-. We deduce the masses of the two states to be m(B_{s1}) = 5829.4 +- 0.7 MeV/c^2 and m(B_{s2}^*) = 5839.7 +- 0.7 MeV/c^2.Comment: Version accepted and published by Phys. Rev. Let

Best Practices and Joint Calling of the HumanExome BeadChip: The CHARGE Consortium

Genotyping arrays are a cost effective approach when typing previously-identified genetic polymorphisms in large numbers of samples. One limitation of genotyping arrays with rare variants (e.g., minor allele frequency [MAF] <0.01) is the difficulty that automated clustering algorithms have to accurately detect and assign genotype calls. Combining intensity data from large numbers of samples may increase the ability to accurately call the genotypes of rare variants. Approximately 62,000 ethnically diverse samples from eleve

Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012