Pion and kaon physics with improved staggered quarks

We compute pseudoscalar meson masses and decay constants using staggered quarks on lattices with three flavors of sea quarks and lattice spacings $\approx 0.12$ fm and $\approx 0.09$ fm. We fit partially quenched results to ``staggered chiral perturbation theory'' formulae, thereby taking into account the effects of taste-symmetry violations. Chiral logarithms are observed. From the fits we calculate $f_\pi$ and $f_K$, extract Gasser-Leutwyler parameters of the chiral Lagrangian, and (modulo rather large perturbative errors) find the light and strange quark masses.Comment: Lattice2003(spectrum); 3 pages, 1 eps figur

First determination of the strange and light quark masses from full lattice QCD

We compute the strange quark mass $m_s$ and the average of the $u$ and $d$ quark masses $\hat m$ using full lattice QCD with three dynamical quarks combined with experimental values for the pion and kaon masses. The simulations have degenerate $u$ and $d$ quarks with masses $m_u=m_d\equiv \hat m$ as low as $m_s/8$, and two different values of the lattice spacing. The bare lattice quark masses obtained are converted to the \msbar scheme using perturbation theory at $O(alpha_s)$. Our results are: m_s^\msbar(2 GeV) = 76(0)(3)(7)(0) MeV, \hat m^\msbar(2 GeV) = 2.8(0)(1)(3)(0) MeV and $m_s/\hat m$ = 27.4(1)(4)(0)(1), where the errors are from statistics, simulation, perturbation theory, and electromagnetic effects, respectively.Comment: 5 pages, revtex, 2 figures. v2: New ms/hat(m) discussion and reference, v3: slight change in discussion of referenc

MSMS: a coalescent simulation program including recombination, demographic structure and selection at a single locus

Motivation: We have implemented a coalescent simulation program for a structured population with selection at a single diploid locus. The program includes the functionality of the simulator ms to model population structure and demography, but adds a model for deme- and time-dependent selection using forward simulations. The program can be used, e.g. to study hard and soft selective sweeps in structured populations or the genetic footprint of local adaptation. The implementation is designed to be easily extendable and widely deployable. The interface and output format are compatible with ms. Performance is comparable even with selection included

Chemical and structural characterization of char development during lignocellulosic biomass pyrolysis

The chemical and structural changes of three lignocellulosic biomass samples during pyrolysis were investigated using both conventional and advanced characterization techniques. The use of ATR-FTIR as a characterization tool is extended by the proposal of a method to determine aromaticity, the calculation of both CH2/CH3 ratio and the degree of aromatic ring condensation ((R/C)u). With increasing temperature, the H/C and O/C ratios, XA and CH2/CH3 ratio decreased, while (R/C)u and aromaticity increased. The micropore network developed with increasing temperature, until the coalescence of pores at 1100 °C, which can be linked to increasing carbon densification, extent of aromatization and/or graphitization of the biomass chars. WAXRD-CFA measurements indicated the gradual formation of nearly parallel basic structural units with increasing carbonization temperature. The char development can be considered to occur in two steps: elimination of aliphatic compounds at low temperatures, and hydrogen abstraction and aromatic ring condensation at high temperatures

The Trojan Chicken Study, Minnesota

County fairs are a possible venue for animal-to-human pathogen transmission

Basin Approach to Address Bacterial Impairments in Basins 15, 16, and 17

In the 2012 Texas Integrated Report and 303(d) List, approximately 48% of the 568 impaired water bodies were caused by high bacteria levels. Once a water body has been listed, the Clean Water Act requires action to be undertaken to restore water quality in that water body. Several options exist to achieve this, which include additional monitoring, a standards assessment, development of a total maximum daily load (TMDL) or development of another watershed based plan such as a watershed protection plan. Traditionally, impairments have been addressed one at a time. In order to more efficiently address similar impairments within the same basin, more efficiently distribute resources, and with the hopes of preventing future listings within the same watershed, a new basin wide approach is being implemented in the Texas River Basins 15 (Colorado – Lavaca), 16 (Lavaca), and 17 (Lavaca Guadalupe). These watersheds, collectively referred to as the Matagorda Bay watershed have five water body assessment units impaired for elevated levels of fecal indicator bacteria: Carancahua Bay, Arenosa Creek, Tres Palacios Creek and two segments of the Lavaca River. This report discusses the current and historical state of the study area and focuses on describing the physical, hydrological, climatic, and demographic conditions as well as potential sources of pollution. Information presented will be used in future water quality analysis and will assist in determining how to address bacteria impairments in the watershed. Information is compiled on a watershed level, summarizing all three basins, as well as within each basin where appropriate

Integration and Test of the Microwave Radiometer Technology Acceleration (MiRaTA) CubeSat

The Microwave Radiometer Technology Acceleration (MiRaTA) Mission is a 3U CubeSat mission developed for NASA ESTO by MIT and MIT Lincoln Laboratory. MiRaTA aims to increase the quality and temporal coverage of Earth atmospheric microwave sounding measurements while leveraging the low costs associated with the CubeSat form factor. Microwave radiometry is a significant contributor to weather and climate monitoring programs, but the typical sun-synchronous orbits of radiometers\u27 host satellites limit revisit times. Another complication for microwave radiometers on meteorological satellites is the difficulty in achieving reliable ground calibration of brightness temperature measurements because internal calibration targets are subject to on-orbit variability that is difficult to model on the ground. MiRaTA will perform multi-channel radiometry over three frequency bands at 52-58 GHz, 175-191 GHz, and 206-208 GHz to measure temperature, water vapor, and cloud ice. MiRaTA also hosts the Compact Total Electron Count (TEC) / Atmospheric GPS sensor (CTAGS), a GPS Radio Occultation (GPSRO) system based on a modified off-the-shelf GPS receiver and a purpose-built patch antenna array. MiRaTA will use CTAGS to demonstrate radiometer calibration using an internal noise diode and co-located GPSRO measurements. By doing so, it will avoid using an expensive and bulky internal calibration targets commonly used for microwave radiometry. The MiRaTA CubeSat has completed integration and environmental testing, and is awaiting launch as part of the ELaNa XIV in 2017 with the Joint Polar Satellite System 1 (JPSS-1). All tests have been completed, including both self-imposed tests as well as tests required by the launch service provider. A payload thermal vacuum test was conducted involving a spinning payload with a cold blackbody target and a hot blackbody target to confirm proper functioning of the MiRaTA radiometer. Results indicate that the calibration accuracy for seven V-band channels and four G-band channels is within task readiness level advancement requirements; however, one channel for the G-band experiences higher noise than expected. Additionally, the CTAGS unit was verified to work with the integrated spacecraft. Results are also presented on the accuracy of thermal model predictions found by comparing the model to measured temperatures during the thermal vacuum. In addition to a detailed update on the integration and test process with lessons learned, we also discuss development of the ground station, over-the-air communications testing, data processing and distribution plans, and operational plans for the projected late-summer launch of MiRaTA. The Microwave Radiometer Technology Acceleration (MiRaTA) Mission is a 3U CubeSat mission developed for NASA ESTO by MIT and MIT Lincoln Laboratory. MiRaTA aims to increase the quality and temporal coverage of Earth atmospheric microwave sounding measurements while leveraging the low costs associated with the CubeSat form factor. Microwave radiometry is a significant contributor to weather and climate monitoring programs, but the typical sun-synchronous orbits of radiometers\u27 host satellites limit revisit times. Another complication for microwave radiometers on meteorological satellites is the difficulty in achieving reliable ground calibration of brightness temperature measurements because internal calibration targets are subject to on-orbit variability that is difficult to model on the ground. MiRaTA will perform multi-channel radiometry over three frequency bands at 52-58 GHz, 175-191 GHz, and 206-208 GHz to measure temperature, water vapor, and cloud ice. MiRaTA also hosts the Compact Total Electron Count (TEC) / Atmospheric GPS sensor (CTAGS), a GPS Radio Occultation (GPSRO) system based on a modified off-the-shelf GPS receiver and a purpose-built patch antenna array. MiRaTA will use CTAGS to demonstrate radiometer calibration using an internal noise diode and co-located GPSRO measurements. By doing so, it will avoid using an expensive and bulky internal calibration targets commonly used for microwave radiometry. The MiRaTA CubeSat has completed integration and environmental testing, and is awaiting launch as part of the ELaNa XIV in 2017 with the Joint Polar Satellite System 1 (JPSS-1). All tests have been completed, including both self-imposed tests as well as tests required by the launch service provider. A payload thermal vacuum test was conducted involving a spinning payload with a cold blackbody target and a hot blackbody target to confirm proper functioning of the MiRaTA radiometer. Results indicate that the calibration accuracy for seven V-band channels and four G-band channels is within task readiness level advancement requirements; however, one channel for the G-band experiences higher noise than expected. Additionally, the CTAGS unit was verified to work with the integrated spacecraft. Results are also presented on the accuracy of thermal model predictions found by comparing the model to measured temperatures during the thermal vacuum. In addition to a detailed update on the integration and test process with lessons learned, we also discuss development of the ground station, over-the-air communications testing, data processing and distribution plans, and operational plans for the projected late-summer launch of MiRaTA

Bipartite Entanglement in Continuous-Variable Cluster States

We present a study of the entanglement properties of Gaussian cluster states, proposed as a universal resource for continuous-variable quantum computing. A central aim is to compare mathematically-idealized cluster states defined using quadrature eigenstates, which have infinite squeezing and cannot exist in nature, with Gaussian approximations which are experimentally accessible. Adopting widely-used definitions, we first review the key concepts, by analysing a process of teleportation along a continuous-variable quantum wire in the language of matrix product states. Next we consider the bipartite entanglement properties of the wire, providing analytic results. We proceed to grid cluster states, which are universal for the qubit case. To extend our analysis of the bipartite entanglement, we adopt the entropic-entanglement width, a specialized entanglement measure introduced recently by Van den Nest M et al., Phys. Rev. Lett. 97 150504 (2006), adapting their definition to the continuous-variable context. Finally we add the effects of photonic loss, extending our arguments to mixed states. Cumulatively our results point to key differences in the properties of idealized and Gaussian cluster states. Even modest loss rates are found to strongly limit the amount of entanglement. We discuss the implications for the potential of continuous-variable analogues of measurement-based quantum computation.Comment: 22 page