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Sample records for elekriki haste shekafande

  1. Disrupting the Education Monopoly: A Conversation with Reed Hastings

    ERIC Educational Resources Information Center

    Jacobs, Joanne

    2015-01-01

    This article features an interview with Netflix CEO, Reed Hastings. In this interview, Hastings relates that he told the "Wall Street Journal" in 2008 that he started looking at education--trying to figure out why our education is lagging when our technology is increasing at great rates and there's great innovation in so many other…

  2. E SERIES MAGAZINES FROM HASTINGS ST. SHOWING ACCESS DRIVE AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    E SERIES MAGAZINES FROM HASTINGS ST. SHOWING ACCESS DRIVE AND LOADING PLATFORMS. E 103 MAGAZINES IN FORGROUND. - Naval Magazine Lualualei, Headquarters Branch, Magazine Type, Eleventh, Thirteenth, Fifteenth, Sixteenth, & Seventeenth Streets, Pearl City, Honolulu County, HI

  3. The Lady Hastings' Charity Schools: Accounting for Eighteenth-Century Rural Philanthropy.

    ERIC Educational Resources Information Center

    Baker, Mae

    1997-01-01

    Describes the philanthropic activities of Lady Elizabeth Hastings and the local provision of rural charity schools in 18th-century England. Covers Hastings' background, her establishment of girls' charity schools, charity-school curricula, the Society for the Promotion of Christian Knowledge, and charity-school teachers. Evaluates Hastings'…

  4. Comparison between EPI and HASTE for ultra-fast MR imaging of the human brain.

    PubMed

    Ge, Y; Korogi, Y; Sugahara, T; Shigematsu, Y; Hirai, T; Kitajima, M; Liang, L; Dai, J; Takahashi, M

    2001-12-01

    Our purpose was to evaluate and compare the performance of ultra-fast single-shot T2-weighted sequences: echo-planar imaging (EPI) versus half-Fourier single-shot turbo spin-echo (HASTE) and to assess the usefulness of their combined reading. Comparative experiments on a phantom as well as a prospective clinical study in 47 patients were done. Axial images acquired with the following methods were compared: (a) HASTE; (b) segmented HASTE (s-HASTE); (c) single-shot spin-echo EPI (SE-EPI); and (d) gradient-echo EPI (GREEPI). Quantitative and qualitative criteria as well as lesion detectability were analyzed against the "gold standard" fast spin-echo (FSE) sequence. For contrast and contrast-to-noise ratio (CNR) between gray and white matter, GRE-EPI was best. The visibility of small markedly hyperintense lesion was best with HASTE and s-HASTE in the clinical study. Small hyperintense lesions were detected equally well with all four sequences, although all performed significantly worse than FSE. The two HASTE variants were better than the EPIs for the extraaxial lesions. The combination of the GRE-EPI and s-HASTE was judged best, and sometimes superior to the FSE image. HASTE or EPI alone cannot substitute for FSE in the screening evaluation of the brain. However, together, EPI and HASTE could provide comparable diagnostic information to that of FSE because their combination compensates for their individual limitations.

  5. Superfund record of decision amendment (EPA Region 7): Hastings Ground Water Contamination Site (east industrial park), Surface Soils Operable Unit, Hastings, NE, February 28, 1995

    SciTech Connect

    1995-10-01

    This decision document presents an amendment to the selected interim remedial action for the Surface Soils Operable Unit at the Hasting East Industrial Park, Hastings, Nebraska. This operable unit addresses the surface soils (0-10 ft. deep) of the Hastings East Industrial Park, which may serve as a source of ground water contamination and the risks associated with exposure to the contaminated soils by excavating, treating, and disposing of the contaminated soil. The amended remedy includes permanent destruction through incineration of the highly concentrated organic-contaminated soils, stabilization of metals-contaminated soils, and containment of low level TNT-contaminated soils and the stabilized metal-contaminated soil. Organic-contaminated soils include those soils containing the explosives compound 2,4,6-trinitrotoluene (TNT) and carcinogenic polycyclic aromatic hydrocarbon compounds (cPAHs). Soils contaminated with high concentration of cPAHs will be excavated and incinerated.

  6. HASTE sequence with parallel acquisition and T2 decay compensation: application to carotid artery imaging.

    PubMed

    Zhang, Ling; Kholmovski, Eugene G; Guo, Junyu; Choi, Seong-Eun Kim; Morrell, Glen R; Parker, Dennis L

    2009-01-01

    T2-weighted carotid artery images acquired using the turbo spin-echo (TSE) sequence frequently suffer from motion artifacts due to respiration and blood pulsation. The possibility of using HASTE sequence to achieve motion-free carotid images was investigated. The HASTE sequence suffers from severe blurring artifacts due to signal loss in later echoes due to T2 decay. Combining HASTE with parallel acquisition (PHASTE) decreases the number of echoes acquired and thus effectively reduces the blurring artifact caused by T2 relaxation. Further improvement in image sharpness can be achieved by performing T2 decay compensation before reconstructing the PHASTE data. Preliminary results have shown successful suppression of motion artifacts with PHASTE imaging. The image quality was enhanced relative to the original HASTE image, but was still less sharp than a non-motion-corrupted TSE image.

  7. Superfund Record of Decision (EPA Region 7): Hastings Ground Water Contamination FAR-MAR-CO subsite, Hastings Irrigation Pipe Company TCA Soils Operable Unit, Hastings, NE. (Second remedial action), September 1990

    SciTech Connect

    Not Available

    1990-09-28

    The Hastings Ground Water Contamination site (FAR-MAR-CO) is a contaminated aquifer in and near the city of Hastings, Adams County, Nebraska. The site consists of seven source areas, or subsites, contaminated with volatile industrial chemicals. The Record of Decision (ROD) addresses the Zone 2 portion of the FAR-MAR-CO subsite, which has been divided into two general areas of contamination referred to as Zone 1 and Zone 2. Zone 1, which includes grain elevators and areas to the north of the elevators, contains soil, soil-gas, and ground water contaminated with ethylene dibromide and carbon tetrachloride. Zone 1 contamination was addressed in a 1988 ROD. Zone 2, which is owned and operated by the Hastings Irrigation Pipe Company contains soil contamination primarily due to 1,1,1-trichloroethane (TCA) resulting from the disposal of cleaning solvents in Zone 2. Subsequent testing revealed that the concentration of TCA in Zone 2 had been reduced to a protective level. Response actions for ground water contamination near the FAR MAR CO subsite, however, will be addressed in subsequent remedial activities.

  8. Design, Fabrication, and Administration of the Hand Active Sensation Test (HASTe).

    PubMed

    Borstad, Alexandra; Altenburger, Alex; Hannigan, Aaron; LaPorte, Joshua; Mott, Rachael; Nichols-Larsen, Deborah S

    2015-01-01

    The concept of personalizing neurologic rehabilitation, based on individual impairments, has experienced a recent surge. In parallel, the number of outcome measures of upper extremity motor performance has grown. However, clinicians and researchers lack practical, quantitative measures of the hand's natural role as a receptor of the environment. The Hand Active Sensation Test (HASTe), developed by Williams and colleagues in 2006, is a valid and reliable measure of haptic performance. Though not available commercially, the HASTe can be fabricated from inexpensive materials, and it has been used successfully to identify impairments in haptic touch in individuals with stroke. (Williams, 2006). This paper presents the methods of design and fabrication of the HASTe testing kit, as well as a visual screen to be used during administration, and instructions for the tests administration and scoring.

  9. Multiple-try Metropolis Hastings for modeling extreme PM10 data

    NASA Astrophysics Data System (ADS)

    Amin, Nor Azrita Mohd; Adam, Mohd Bakri; Ibrahim, Noor Akma

    2014-07-01

    Awareness of catastrophic events brings the attention to work out the relationship of these events by using statistical analysis of Extreme Value Theory (EVT). This study focused on extreme PM10 data using a Gumbel distribution which is one of the Extreme Value distributions. The parameters were estimated using the new Bayesian approach in extreme called Multiple Try Metropolis-Hastings algorithms. We compared this approach with another Markov Chain Monte Carlo approach which is the classical Metropolis-Hastings algorithm and the frequentist approach, Maximum Likelihood Estimation. It appears that these three approaches provide comparable results. Data are taken for Pasir Gudang station for year 1996 to 2010.

  10. Selected water-quality characteristics in the upper Mississippi River basin, Royalton to Hastings, Minnesota

    USGS Publications Warehouse

    Have, M.R.

    1991-01-01

    Results of this study show that the quality of water in the Mississippi River as it leaves the accounting unit at Hastings is not representative of water quality in most of the accounting unit. Three water-quality regions have been identified, and sampling sites are needed in each region to assess the quality of streams throughout the study area adequately.

  11. Metropolis-Hastings Robbins-Monro Algorithm for Confirmatory Item Factor Analysis

    ERIC Educational Resources Information Center

    Cai, Li

    2010-01-01

    Item factor analysis (IFA), already well established in educational measurement, is increasingly applied to psychological measurement in research settings. However, high-dimensional confirmatory IFA remains a numerical challenge. The current research extends the Metropolis-Hastings Robbins-Monro (MH-RM) algorithm, initially proposed for…

  12. High-Dimensional Exploratory Item Factor Analysis by a Metropolis-Hastings Robbins-Monro Algorithm

    ERIC Educational Resources Information Center

    Cai, Li

    2010-01-01

    A Metropolis-Hastings Robbins-Monro (MH-RM) algorithm for high-dimensional maximum marginal likelihood exploratory item factor analysis is proposed. The sequence of estimates from the MH-RM algorithm converges with probability one to the maximum likelihood solution. Details on the computer implementation of this algorithm are provided. The…

  13. Hastings Center

    MedlinePlus

    ... the AMA Journal of Ethics is devoted to transgender health and medicine. Contributors include Elizabeth Dietz, a ... Physicians Refer When Referral Options Are Limited for Transgender Patients,” which considers the case of a transgender ...

  14. General Metropolis-Hastings jump diffusions for automatic target recognition in infrared scenes

    NASA Astrophysics Data System (ADS)

    Lanterman, Aaron D.; Miller, Michael I.; Snyder, Donald L.

    1997-04-01

    To locate and recognize ground-based targets in forward- looking IR (FLIR) images, 3D faceted models with associated pose parameters are formulated to accommodate the variability found in FLIR imagery. Taking a Bayesian approach, scenes are simulated from the emissive characteristics of the CAD models and compared with the collected data by a likelihood function based on sensor statistics. This likelihood is combined with a prior distribution defined over the set of possible scenes to form a posterior distribution. To accommodate scenes with variable numbers of targets, the posterior distribution is defined over parameter vectors of varying dimension. An inference algorithm based on Metropolis-Hastings jump- diffusion processes empirically samples from the posterior distribution, generating configurations of templates and transformations that match the collected sensor data with high probability. The jumps accommodate the addition and deletion of targets and the estimation of target identities; diffusions refine the hypotheses by drifting along the gradient of the posterior distribution with respect to the orientation and position parameters. Previous results on jumps strategies analogous to the Metropolis acceptance/rejection algorithm, with proposals drawn from the prior and accepted based on the likelihood, are extended to encompass general Metropolis-Hastings proposal densities. In particular, the algorithm proposes moves by drawing from the posterior distribution over computationally tractible subsets of the parameter space. The algorithm is illustrated by an implementation on a Silicon Graphics Onyx/Reality Engine.

  15. Efficient implementation of the Metropolis-Hastings algorithm, with application to the Cormack-Jolly-Seber model

    USGS Publications Warehouse

    Link, W.A.; Barker, R.J.

    2008-01-01

    Judicious choice of candidate generating distributions improves efficiency of the Metropolis-Hastings algorithm. In Bayesian applications, it is sometimes possible to identify an approximation to the target posterior distribution; this approximate posterior distribution is a good choice for candidate generation. These observations are applied to analysis of the Cormack-Jolly-Seber model and its extensions. ?? Springer Science+Business Media, LLC 2007.

  16. Efficient implementation of the Metropolis-Hastings algorithm, with application to the Cormack?Jolly?Seber model

    USGS Publications Warehouse

    Link, W.A.; Barker, R.J.

    2008-01-01

    Judicious choice of candidate generating distributions improves efficiency of the Metropolis-Hastings algorithm. In Bayesian applications, it is sometimes possible to identify an approximation to the target posterior distribution; this approximate posterior distribution is a good choice for candidate generation. These observations are applied to analysis of the Cormack?Jolly?Seber model and its extensions.

  17. 76 FR 58241 - Designation for the Aberdeen, SD; Decatur, IL; Hastings, NE; Fulton, IL; the State of Missouri...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-20

    ..., Federal Register (76 FR 15937), GIPSA requested applications for designation to provide official services... Grain Inspection, Packers and Stockyards Administration Designation for the Aberdeen, SD; Decatur, IL; Hastings, NE; Fulton, IL; the State of Missouri, and the State of South Carolina Areas AGENCY:...

  18. Estimation of Contextual Effects through Nonlinear Multilevel Latent Variable Modeling with a Metropolis-Hastings Robbins-Monro Algorithm

    ERIC Educational Resources Information Center

    Yang, Ji Seung; Cai, Li

    2014-01-01

    The main purpose of this study is to improve estimation efficiency in obtaining maximum marginal likelihood estimates of contextual effects in the framework of nonlinear multilevel latent variable model by adopting the Metropolis-Hastings Robbins-Monro algorithm (MH-RM). Results indicate that the MH-RM algorithm can produce estimates and standard…

  19. Dynamical behavior of fractional-order Hastings-Powell food chain model and its discretization

    NASA Astrophysics Data System (ADS)

    Matouk, A. E.; Elsadany, A. A.; Ahmed, E.; Agiza, H. N.

    2015-10-01

    In this work, the dynamical behavior of fractional-order Hastings-Powell food chain model is investigated and a new discretization method of the fractional-order system is introduced. A sufficient condition for existence and uniqueness of the solution of the proposed system is obtained. Local stability of the equilibrium points of the fractional-order system is studied. Furthermore, the necessary and sufficient conditions of stability of the discretized system are also studied. It is shown that the system's fractional parameter has effect on the stability of the discretized system which shows rich variety of dynamical behaviors such as Hopf bifurcation, an attractor crisis and chaotic attractors. Numerical simulations show the tea-cup chaotic attractor of the fractional-order system and the richer dynamical behavior of the corresponding discretized system.

  20. Evaluating plastic assembly processes for high reliability applications using HAST and Assembly Test Chips

    SciTech Connect

    Emerson, J.A.; Sweet, J.N.; Peterson, D.W.

    1994-05-01

    We demonstrate the use of HAST and Assembly Test Chips to evaluate the susceptability of epoxy molding compounds to moisture induced corrosion of Al conductors. We show that the procedure is sufficiently sensitive to discriminate between assembly processes used by different molding facilities. Our data show that the location in time of the ``knee`` in the failure distribution is dependent on material properties of the epoxy. Reducing the failure rate in the early or ``extrinsic`` region of the time-failure distribution is key to achieving high reliability. Wt examine the failure modes in the extrinsic region for test chips encapsulated with a number of high quality molding compounds in an attempt to better understand this region.

  1. Time Lapse Gravity and Seismic Monitoring of CO2 Injection at the West Hastings Field, Texas

    NASA Astrophysics Data System (ADS)

    Ferguson, J. F.; Richards, T.; Klopping, F.; MacQueen, J.; Hosseini, S. A.

    2015-12-01

    Time lapse or 4D gravity and seismic reflection surveys are being conducted at the West Hastings Field near Houston, Texas to monitor the progress of CO2 injection. This Department of Energy supported CO2 sequestration experiment is conducted in conjunction with a Denbury Onshore, LLC tertiary recovery project. The reservoir is at a depth of 1.8 km in the Oligocene Frio sands and has been produced since the 1930s. Goals are an accounting and mapping of the injected CO2 and to determine if migration occurs along intra-reservoir faults. An integrated interpretation of the geophysical surveys will be made together with well logs and engineering data. Gravity monitoring of water versus gas replacement has been very successful, but liquid phase CO2 monitoring is problematic due to the smaller density contrast with respect to oil and water. This reservoir has a small volume to depth ratio and hence only a small gravity difference signal is expected on the surface. New borehole gravity technology introduced by Micro-g-Lacoste can make gravity measurements at near reservoir depths with a much higher signal to noise ratio. This method has been successfully evaluated on a simulation of the Hastings project. Field operations have been conducted for repeated surface and borehole gravity surveys beginning in 2013. The surface survey of 95 stations covers an area of 3 by 5 km and 22 borehole gravity logs are run in the interval above the Frio formation. 4D seismic reflection surveys are being made at 6 month intervals on the surface and in 3 VSP wells. CO2 injection into the targeted portion of the reservoir only began in early 2015 and monitoring will continue into 2017. To date only the baseline reservoir conditions have been assessed. The overall success of the gravity monitoring will not be determined until 2017.

  2. Assessment of calcium homeostasis in the critically ill surgical patient. The diagnostic pitfalls of the McLean-Hastings nomogram.

    PubMed Central

    Zaloga, G P; Chernow, B; Cook, D; Snyder, R; Clapper, M; O'Brian, J T

    1985-01-01

    Hypocalcemia is a common problem in critically ill surgical patients. We prospectively evaluated whether measurement of the total serum calcium (Ca) concentration or calculation of the serum ionized Ca level (by the McLean-Hastings nomogram) accurately reflects the measured serum ionized Ca level. Although 71% and 58% of 156 predominantly surgical intensive care unit (ICU) patients were hypocalcemic by the total serum Ca or calculated ionized Ca level, respectively, only 12% were hypocalcemic by directly measured serum ionized Ca measurement. The total serum Ca and calculated ionized Ca concentrations were sensitive (95% and 89%, respectively) but lacked specificity (32% and 46%, respectively) in predicting ionized hypocalcemia. Analyses of Ca binding to albumin in the serum of surgical ICU patients and normal subjects suggested that there is a circulating factor in critically ill patients that increases the binding of Ca to albumin. These observations may explain why the McLean-Hastings nomogram underestimates the protein-induced changes in serum Ca in critically ill surgical subjects. We conclude that: total serum Ca and calculated ionized Ca concentrations are poor indicators of the true serum ionized Ca status in critically ill surgical patients, and we recommend direct measurement of serum ionized Ca levels in these patients; and variability in the affinity of Ca for binding proteins in critical illness may explain the poor correlation between serum total and ionized Ca measurements. PMID:4051606

  3. Estimation of Contextual Effects through Nonlinear Multilevel Latent Variable Modeling with a Metropolis-Hastings Robbins-Monro Algorithm. CRESST Report 833

    ERIC Educational Resources Information Center

    Yang, Ji Seung; Cai, Li

    2013-01-01

    The main purpose of this study is to improve estimation efficiency in obtaining full-information maximum likelihood (FIML) estimates of contextual effects in the framework of a nonlinear multilevel latent variable model by adopting the Metropolis-Hastings Robbins-Monro algorithm (MH-RM; Cai, 2008, 2010a, 2010b). Results indicate that the MH-RM…

  4. A commentary ``on the periodic solutions of a forced second-order equation'' by S. P. Hastings and J. B. McLeod

    NASA Astrophysics Data System (ADS)

    Kaper, T. J.; Wiggins, S.

    1991-06-01

    We discuss the relationship of the shooting and perturbation methods used by Hastings and McLeod in the paper “On the Periodic Solutions of a Forced Second-Order Equation” to the geometrical techniques of nonlinear dynamical systems theory.

  5. Scaling and multiscaling behavior of the perimeter of a diffusion-limited aggregation generated by the Hastings-Levitov method

    NASA Astrophysics Data System (ADS)

    Mohammadi, F.; Saberi, A. A.; Rouhani, S.

    2009-09-01

    In this paper, we analyze the scaling behavior of a diffusion-limited aggregation (DLA) simulated by the Hastings-Levitov method. We obtain the fractal dimension of the clusters by direct analysis of the geometrical patterns, in good agreement with one obtained from an analytical approach. We compute the two-point density correlation function and we show that, in the large-size limit, it agrees with the obtained fractal dimension. These support the statistical agreement between the patterns and DLA clusters. We also investigate the scaling properties of various length scales and their fluctuations, related to the boundary of the cluster. We find that all of the length scales do not have a simple scaling with the same correction to scaling exponent. The fractal dimension of the perimeter is obtained equal to that of the cluster. The growth exponent is computed from the evolution of the interface width equal to β = 0.557(2). We also show that the perimeter of the DLA cluster has an asymptotic multiscaling behavior.

  6. Scaling and multiscaling behavior of the perimeter of a diffusion-limited aggregation generated by the Hastings-Levitov method.

    PubMed

    Mohammadi, F; Saberi, A A; Rouhani, S

    2009-09-16

    In this paper, we analyze the scaling behavior of a diffusion-limited aggregation (DLA) simulated by the Hastings-Levitov method. We obtain the fractal dimension of the clusters by direct analysis of the geometrical patterns, in good agreement with one obtained from an analytical approach. We compute the two-point density correlation function and we show that, in the large-size limit, it agrees with the obtained fractal dimension. These support the statistical agreement between the patterns and DLA clusters. We also investigate the scaling properties of various length scales and their fluctuations, related to the boundary of the cluster. We find that all of the length scales do not have a simple scaling with the same correction to scaling exponent. The fractal dimension of the perimeter is obtained equal to that of the cluster. The growth exponent is computed from the evolution of the interface width equal to β = 0.557(2). We also show that the perimeter of the DLA cluster has an asymptotic multiscaling behavior. PMID:21832341

  7. Constitutive expression of high-affinity sulfate transporter (HAST) gene in Indian mustard showed enhanced sulfur uptake and assimilation.

    PubMed

    Abdin, M Z; Akmal, M; Ram, M; Nafis, T; Alam, P; Nadeem, M; Khan, M A; Ahmad, A

    2011-07-01

    Lycopersicon esculantum sulfate transporter gene (LeST 1.1) encodes a high-affinity sulfate transporter (HAST) located in root epidermis. In this study, the LeST 1.1 gene was constitutively expressed in Indian mustard (Brassica juncea cv. Pusa Jai Kisan). Transgenic as well as untransformed plants were grown in sulfur-insufficient (25 and 50 μM) and sulfur-sufficient (1,000 μM) conditions for 30 days. Two-fold increase was noticed in the sulfate uptake rate of transgenic plants grown in both sulfur-insufficient and -sufficient conditions as compared to untransformed plants. The transgenic B. juncea plants were able to accumulate higher biomass and showed improved sulfur status even in sulfur-insufficient conditions when compared with untransformed plants. Chlorophyll content, ATP sulfurylase activity and protein content were also higher in transgenic plants than untranformed plants under sulfur-insufficient conditions. Our results, thus, clearly indicate that constitutive expression of LeST 1.1 gene in B. juncea had led to enhanced capacity of sulfur uptake and assimilation even in sulfur-insufficient conditions. This approach can also be used in other crops to enhance their sulfate uptake and assimilation potential under S-insufficient conditions. PMID:20938698

  8. Recovery of the seabed following marine aggregate dredging on the Hastings Shingle Bank off the southeast coast of England

    NASA Astrophysics Data System (ADS)

    Cooper, Keith; Boyd, Sian; Eggleton, Jacqueline; Limpenny, David; Rees, Hubert; Vanstaen, Koen

    2007-12-01

    The aim of this study was to investigate the effect of dredging intensity on the physical and biological recovery times of the seabed following marine aggregate dredging. Two areas of seabed, previously subject to, respectively, relatively high and lower levels of dredging intensity, were identified on the Hastings Shingle Bank. Two reference areas were also selected for comparative purposes. All four sites were monitored annually over the period 2001-2004, using a combination of acoustic, video and grab sampling techniques. Since the site was last dredged in 1996, this was intended to provide a sequence of data 5-8 years after cessation of dredging. However, an unexpected resumption of dredging within the high intensity site, during 2002 and 2003, allowed an additional assessment of the immediate effects and aftermath of renewed dredging at the seabed. The early stages of recovery could then be assessed after dredging ceased in 2003. Results from both dredged sites provide a useful insight into the early and latter stages of physical and biological recovery. A comparison of recent and historic dredge track features provided evidence of track erosion. However, tracks were still visible 8 years after the cessation of dredging. Within the high dredging intensity site, recolonisation was relatively rapid after the cessation of dredging in 2003. Rather than indicating a full recovery, we suggest that this initial 'colonization community' may enter a transition phase before eventually reaching equilibrium. This hypothesis is supported by results from the low intensity site, where biological recovery was judged to have taken 7 years. Further monitoring is needed in order to test this. An alternative explanation is that the rapid recovery may be explained by the settlement of large numbers of Sabellaria spinulosa. As the resumption of dredging within the high intensity site limited our assessment of longer-term recovery it is not yet possible to assume that a 7-year

  9. Two-dimensional direct-current resistivity survey to supplement borehole data in ground-water models of the former Blaine Naval Ammunition Depot, Hastings, Nebraska, September 2003

    USGS Publications Warehouse

    Kress, Wade H.; Ball, Lyndsay B.; Teeple, Andrew P.; Turco, Michael J.

    2006-01-01

    The former Blaine Naval Ammunition Depot located immediately southeast of Hastings, Nebraska, was an ammunition facility during World War II and the Korean Conflict. Waste-management practices during operation and decommissioning of the former Depot resulted in soil and ground-water contamination. Ground-water models have been used by the U.S. Army Corps of Engineers to provide information on the fate and transport of contaminants on the former Depot site. During September 2003, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, Kansas City District, conducted a pilot study to collect two-dimensional direct-current resistivity data on the site along six profiles near existing monitoring wells. The inversion results of field data from five of the six two-dimensional direct-current resistivity profiles display distinct electrical stratigraphy consistent with three resistivity units (low resistivity, high resistivity, and low resistivity). These three resistivity units correlate with rock-stratigraphic or hydrogeologic units described prior to this study. To interpret the resistivity profiles, additional data extending through the lower confining unit into the underlying Niobrara Formation could be used with the existing data to construct forward models for data analysis and interpretation.

  10. Benefits of a new Metropolis-Hasting based algorithm, in non-linear regression for estimation of ex vivo antimalarial sensitivity in patients infected with two strains.

    PubMed

    Bauer, Rebecca; Mentré, France; Kaddouri, Halima; Le Bras, Jacques; Le Nagard, Hervé

    2014-12-01

    Malaria is one of the world׳s most widespread parasitic diseases. The parasitic protozoans of the genus Plasmodium have developed resistance to several antimalarial drugs. Some patients are therefore infected by two or more strains with different levels of antimalarial drug sensitivity. We previously developed a model to estimate the drug concentration (IC50) that inhibits 50% of the growth of the parasite isolated from a patient infected with one strain. We propose here a new Two-Slopes model for patients infected by two strains. This model involves four parameters: the proportion of each strain and their IC50, and the sigmoidicity parameter. To estimate the parameters of this model, we have developed a new algorithm called PGBO (Population Genetics-Based Optimizer). It is based on the Metropolis-Hasting algorithm and is implemented in the statistical software R. We performed a simulation study and defined three evaluation criteria to evaluate its properties and compare it with three other algorithms (Gauss-Newton, Levenberg-Marquardt, and a simulated annealing). We also evaluated it using in vitro data and three ex vivo datasets from the French Malaria Reference Center. Our evaluation criteria in the simulation show that PGBO gives good estimates of the parameters even if the concentration design is poor. Moreover, our algorithm is less sensitive than Gauss-Newton algorithms to initial values. Although parameter estimation is good, interpretation of the results can be difficult if the proportion of the second strain is close to 0 or 1. For these reasons, this approach cannot yet be implemented routinely. PMID:25450214

  11. Using satellite observations to improve model estimates of CO2 and CH4 flux: a Metropolis Hastings Markov Chain Monte Carlo approach

    NASA Astrophysics Data System (ADS)

    MacBean, Natasha; Disney, Mathias; Lewis, Philip; Ineson, Phil

    2010-05-01

    profile as a whole. We present results from an Observing System Simulation Experiment (OSSE) designed to investigate the impact of management and climate change on peatland carbon fluxes, as well as how observations from satellites may be able to constrain modeled carbon fluxes. We use an adapted version of the Carnegie-Ames-Stanford Approach (CASA) model (Potter et al., 1993) that includes a representation of methane dynamics (Potter, 1997). The model formulation is further modified to allow for assimilation of satellite observations of surface soil moisture and land surface temperature. The observations are used to update model estimates using a Metropolis Hastings Markov Chain Monte Carlo (MCMC) approach. We examine the effect of temporal frequency and precision of satellite observations with a view to establishing how, and at what level, such observations would make a significant improvement in model uncertainty. We compare this with the system characteristics of existing and future satellites. We believe this is the first attempt to assimilate surface soil moisture and land surface temperature into an ecosystem model that includes a full representation of CH4 flux. Bubier, J., and T. Moore (1994), An ecological perspective on methane emissions from northern wetlands, TREE, 9, 460-464. Charman, D. (2002), Peatlands and Environmental Change, JohnWiley and Sons, Ltd, England. Gorham, E. (1991), Northern peatlands: Role in the carbon cycle and probable responses to climatic warming, Ecological Applications, 1, 182-195. Lai, D. (2009), Methane dynamics in northern peatlands: A review, Pedosphere, 19, 409-421. Le Mer, J., and P. Roger (2001), Production, oxidation, emission and consumption of methane by soils: A review, European Journal of Soil Biology, 37, 25-50. Limpens, J., F. Berendse, J. Canadell, C. Freeman, J. Holden, N. Roulet, H. Rydin, and Potter, C. (1997), An ecosystem simulation model for methane production and emission from wetlands, Global Biogeochemical

  12. Avoid haste in defining human muscular Sarcocystosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We appreciate Dr. Italiano’s [1] interest in our article [2] and agree that our case definition, described in our methods as ‘intentionally specific,’ may have resulted in the exclusion of some travelers infected with Sarcocystis nesbitti. Nevertheless, we believe published data from outbreak invest...

  13. Cases in Bioethics from the Hastings Center Report.

    ERIC Educational Resources Information Center

    Levine, Carol, Ed.; Veatch, Robert M.

    Case studies of ethical issues based on real events are followed by comments illustrating how people from various ethical traditions and frameworks and from different academic and professional disciplines analyze the issues and work toward a resolution of the conflict posed. The cases are intended to help the public and professional persons pursue…

  14. Child malnutrition and the Millennium Development Goals: much haste but less speed?

    PubMed

    Oruamabo, Raphael S

    2015-02-01

    The Millennium Development Goals (MDGs) provide a framework for measuring the progress of nations. Several of these goals relate to child malnutrition, which remains an important contributor to child morbidity and mortality, accounting for approximately 45% of child deaths globally. A high proportion of undernourished children still live in Africa and parts of Asia, and the uneven rate of reduction in the prevalence of various types of child malnutrition among different income groups worldwide is worrying. Attempts to reduce child malnutrition should therefore begin from the grassroots by improving primary healthcare services in developing countries with particular focus on basic requirements. Adequate nutrition should be provided from birth, through infancy, preschool and early childhood to adolescence. The overall strategy should be one of careful and meticulous planning involving all development sectors with an emphasis on a bottom-up approach within a stable and disciplined polity; the MDGs will be only be useful if they are seen not as narrow objectives with unidirectional interventions but as multifaceted and co-ordinated. The setting of deadlines, whether 2015 or 2035, should not be emphasised so as to avoid hasty decision making. The top priority should be the implementation of the essential social services of basic education, primary healthcare, nutrition, reproductive health care, water and sanitation in partnership with the developed economies.

  15. The Ethics of Legislative Life. A Report by the Hastings Center.

    ERIC Educational Resources Information Center

    Hastings Center, Hastings-on-Hudson, NY.

    Results of a two-year research project (1982-84) on Legislative and Representative Ethics are presented in this report, which analyzes the basic principles of legislative ethics, discusses the special dilemmas and obligations of legislators, and offers conclusions about future steps that could be taken to enhance public discussion and to reinforce…

  16. Ecological impacts of tributyltin on estuarine communities in the Hastings River, NSW Australia.

    PubMed

    Roach, A C; Wilson, S P

    2009-12-01

    Oyster (Saccostrea commercialis) biomonitoring, assessment of oyster and gastropod (Bembicium auratum) abundance, and gastropod imposex were used to measure the significance of tributyltin (TBT) contamination in an intertidal mangrove forest. We studied the bioavailable levels of TBT in oysters approximately 1 km downstream and 2 km upstream from a TBT waste disposal site. We found observable declines in the abundance of oysters and gastropods correlated with the bioavailable TBT and these findings were confirmed by mapping oyster beds. Oyster cover near the disposal site ranged from 0% to 5% while downstream and upstream populations ranged in cover from 25-50% to 5-25%, respectively. Similarly, gastropod abundances at the disposal site were only 7% of the downstream population and 17% of the upstream population. Imposex was present in 90% of female B. auratum from populations near the disposal site but this effect declined more sharply than the population level effects.

  17. Haste Makes Waste: The Interplay Between Dissolution and Precipitation of Supersaturating Formulations.

    PubMed

    Sun, Dajun D; Lee, Ping I

    2015-11-01

    Contrary to the early philosophy of supersaturating formulation design for oral solid dosage forms, current evidence shows that an exceedingly high rate of supersaturation generation could result in a suboptimal in vitro dissolution profile and subsequently could reduce the in vivo oral bioavailability of amorphous solid dispersions. In this commentary, we outline recent research efforts on the specific effects of the rate and extent of supersaturation generation on the overall kinetic solubility profiles of supersaturating formulations. Additional insights into an appropriate definition of sink versus nonsink dissolution conditions and the solubility advantage of amorphous pharmaceuticals are also highlighted. The interplay between dissolution and precipitation kinetics should be carefully considered in designing a suitable supersaturating formulation to best improve the dissolution behavior and oral bioavailability of poorly water-soluble drugs. PMID:26338234

  18. 76 FR 72867 - Proposed Amendment of Class E Airspace; Hastings, NE

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-28

    ... FURTHER INFORMATION CONTACT: Scott Enander, Central Service Center, Operations Support Group, Federal... also be examined during normal business hours at the office of the Central Service Center, 2601 Meacham...; (2) is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034;...

  19. 77 FR 35960 - City of Hastings, MN; Notice of Application for Amendment of License and Soliciting Comments...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

    ... delete the two hydrokinetic turbines from the Mississippi Lock and Dam No. 2 conventional hydropower... hydrokinetic units was deployed, and the unit has been removed and out of service since mid-2010 due to... conventional hydropower project has been returned to its pre- hydrokinetic unit condition. Therefore,...

  20. Estimation of Contextual Effects through Nonlinear Multilevel Latent Variable Modeling with a Metropolis-Hastings Robbins-Monro Algorithm

    ERIC Educational Resources Information Center

    Yang, Ji Seung

    2012-01-01

    Nonlinear multilevel latent variable modeling has been suggested as an alternative to traditional hierarchical linear modeling to more properly handle measurement error and sampling error issues in contextual effects modeling. However, a nonlinear multilevel latent variable model requires significant computational effort because the estimation…

  1. When Does Haste Make Waste? Speed-Accuracy Tradeoff, Skill Level, and the Tools of the Trade

    ERIC Educational Resources Information Center

    Beilock, Sian L.; Bertenthal, Bennett I.; Hoerger, Michael; Carr, Thomas H.

    2008-01-01

    Novice and skilled golfers took a series of golf putts with a standard putter (Exp. 1) or a distorted "funny putter" (consisting of an s-shaped and arbitrarily weighted putter shaft; Exp. 2) under instructions to either (a) take as much time as needed to be accurate or to (b) putt as fast as possible while still being accurate. Planning and…

  2. Estimation of a Ramsay-Curve Item Response Theory Model by the Metropolis-Hastings Robbins-Monro Algorithm

    ERIC Educational Resources Information Center

    Monroe, Scott; Cai, Li

    2014-01-01

    In Ramsay curve item response theory (RC-IRT) modeling, the shape of the latent trait distribution is estimated simultaneously with the item parameters. In its original implementation, RC-IRT is estimated via Bock and Aitkin's EM algorithm, which yields maximum marginal likelihood estimates. This method, however, does not produce the…

  3. When does haste make waste? Speed-accuracy tradeoff, skill level, and the tools of the trade.

    PubMed

    Beilock, Sian L; Bertenthal, Bennett I; Hoerger, Michael; Carr, Thomas H

    2008-12-01

    Novice and skilled golfers took a series of golf putts with a standard putter (Exp. 1) or a distorted funny putter (consisting of an s-shaped and arbitrarily weighted putter shaft; Exp. 2) under instructions to either (a) take as much time as needed to be accurate or to (b) putt as fast as possible while still being accurate. Planning and movement time were measured for each putt. In both experiments, novices produced the typical speed-accuracy trade-off. Going slower, in terms of both the planning and movement components of execution, improved performance. In contrast, skilled golfers benefited from reduced performance time when using the standard putter in Exp. 1 and, specifically, taking less time to plan improved performance. In Exp. 2, skilled golfers improved by going slower when using the funny putter, but only when it was unfamiliar. Thus, skilled performance benefits from speed instructions when wielding highly familiar tools (i.e., the standard putter) is harmed when using new tools (i.e., the funny putter), and benefits again by speed instructions as the new tool becomes familiar. Planning time absorbs these changes. PMID:19102617

  4. 76 FR 15936 - Opportunity for Designation in the Aberdeen, SD; Decatur, IL; Hastings, NE; Fulton, IL; the State...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-22

    ... Dakota-South Dakota State line east; Bounded on the East by the eastern South Dakota State line (the Big... contiguous ] geographic area, are part of this geographic area assignment: Farmers Coop, and Big Springs Elevator, both in Big Springs, Deuel County (located inside Kansas Grain Inspection Service, Inc.'s...

  5. Haste Makes Waste: Accelerated Molt Adversely Affects the Expression of Melanin-Based and Depigmented Plumage Ornaments in House Sparrows

    PubMed Central

    Vágási, Csongor I.; Pap, Péter L.; Barta, Zoltán

    2010-01-01

    Background Many animals display colorful signals in their integument which convey information about the quality of their bearer. Theoretically, these ornaments incur differential production and/or maintenance costs that enforce their honesty. However, the proximate mechanisms of production costs are poorly understood and contentious in cases of non-carotenoid-based plumage ornaments like the melanin-based badge and depigmented white wing-bar in house sparrows Passer domesticus. Costly life-history events are adaptively separated in time, thus, when reproduction is extended, the time available for molt is curtailed and, in turn, molt rate is accelerated. Methodology/Principal Findings We experimentally accelerated the molt rate by shortening the photoperiod in order to test whether this environmental constraint is mirrored in the expression of plumage ornaments. Sparrows which had undergone an accelerated molt developed smaller badges and less bright wing-bars compared to conspecifics that molted at a natural rate being held at natural-like photoperiod. There was no difference in the brightness of the badge or the size of the wing-bar. Conclusions/Significance These results indicate that the time available for molt and thus the rate at which molt occurs may constrain the expression of melanin-based and depigmented plumage advertisements. This mechanism may lead to the evolution of honest signaling if the onset of molt is condition-dependent through the timing of and/or trade-off between breeding and molt. PMID:21151981

  6. 76 FR 61038 - Standard Instrument Approach Procedures, and Takeoff Minimums and Obstacle Departure Procedures...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ... Policies and Procedures (44 FR 11034; February 26,1979); and (3) does not warrant preparation of a...: On September 15, 2011 (76 FR 56970), the FAA published an Amendment in Docket No. 30801, Amdt No... Hastings, MI, Hastings, RNAV (GPS) RWY 12, Orig Hastings, MI, Hastings, RNAV (GPS) RWY 30, Orig...

  7. Structural, Mechanistic, and Antigenic Characterization of the Human Astrovirus Capsid

    PubMed Central

    York, Royce L.; Yousefi, Payam A.; Bogdanoff, Walter; Haile, Sara; Tripathi, Sarvind

    2015-01-01

    ABSTRACT Human astroviruses (HAstVs) are nonenveloped, positive-sense, single-stranded RNA viruses that are a leading cause of viral gastroenteritis. HAstV particles display T=3 icosahedral symmetry formed by 180 copies of the capsid protein (CP), which undergoes proteolytic maturation to generate infectious HAstV particles. Little is known about the molecular features that govern HAstV particle assembly, maturation, infectivity, and immunogenicity. Here we report the crystal structures of the two main structural domains of the HAstV CP: the core domain at 2.60-Å resolution and the spike domain at 0.95-Å resolution. Fitting of these structures into the previously determined 25-Å-resolution electron cryomicroscopy density maps of HAstV allowed us to characterize the molecular features on the surfaces of immature and mature T=3 HAstV particles. The highly electropositive inner surface of HAstV supports a model in which interaction of the HAstV CP core with viral RNA is a driving force in T=3 HAstV particle formation. Additionally, mapping of conserved residues onto the HAstV CP core and spike domains in the context of the immature and mature HAstV particles revealed dramatic changes to the exposure of conserved residues during virus maturation. Indeed, we show that antibodies raised against mature HAstV have reactivity to both the HAstV CP core and spike domains, revealing for the first time that the CP core domain is antigenic. Together, these data provide new molecular insights into HAstV that have practical applications for the development of vaccines and antiviral therapies. IMPORTANCE Astroviruses are a leading cause of viral diarrhea in young children, immunocompromised individuals, and the elderly. Despite the prevalence of astroviruses, little is known at the molecular level about how the astrovirus particle assembles and is converted into an infectious, mature virus. In this paper, we describe the high-resolution structures of the two main astrovirus

  8. 75 FR 25917 - Qualification of Drivers; Exemption Applications; Vision

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-10

    ..., 2000 (65 FR 19476). This information is also available at http://www.regulations.gov . FOR FURTHER... prosthetic left eye since 1998. The best corrected visual acuity in his right eye is 20/25. Following an... convictions for moving violations in a CMV. Ricky P. Hastings Mr. Hastings, 55, has had a prosthetic left...

  9. 1. Photocopied October 1976, from F.B. Tower, Illistrations of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Photocopied October 1976, from F.B. Tower, Illistrations of the Croton Aqueduct, New York: Wiley and Putnam, 1843. CROTON AQUEDUCT AT HASTINGS: ARCH PROVIDED ACCESS TO STONE QUARRY. PLATE XVII, PAGE 106. - Old Croton Aqueduct, Quarry Railroad Bridge, Aqueduct Lane at Williams Street, Hastings-on-Hudson, Westchester County, NY

  10. Wisdom from the Factory Floor: For Best Results, Limit Initiatives, Build Capacity, and Monitor Progress

    ERIC Educational Resources Information Center

    Dumas, Chad; Kautz, Craig

    2014-01-01

    In the Hastings Nebraska Public schools, two of the eight schools have been identified as national models of educational effectiveness. In seven of eight buildings, in just four years, student test scores have increased from around 60% proficiency to around 80% proficiency or better. At Hastings, central office leaders emphasize three key…

  11. Wastewater Analysis Indicates that Genetically Diverse Astroviruses, Including Strains Belonging to Novel Clades MLB and VA, Are Circulating within Japanese Populations

    PubMed Central

    Katayama, Hiroyuki; Kitajima, Masaaki; Furumai, Hiroaki

    2015-01-01

    Human astroviruses (HAstVs) are a common etiological agent of infantile gastroenteritis. Recent studies revealed that novel astrovirus (AstV) strains of the MLB clade (MLB-AstVs) and VA clade (VA-AstVs), which are genetically distinct from the classic HAstVs, are circulating in the human population. In the present study, we quantified classic HAstVs as well as carried out a genetic analysis of classic and novel HAstVs in wastewater in Japan. The concentration of classic HAstVs in the influent water samples ranged from 104 to 105 copies per liter, and the amount removed by wastewater treatment was determined to be 2.4 ± 0.3 log10. Four types of classic HAstV strains (HAstV types 1, 2, 5, and 4/8) as well as novel AstV strains belonging to the MLB-2, VA-1, and VA-2 clades were identified using reverse transcription-PCR (RT-PCR) assays, including assays newly developed for the detection of strains of the MLB and VA clades, followed by cloning and nucleotide sequencing. Our results suggest that genetically diverse AstV strains are circulating among the human population in Japan. The newly developed (semi)nested RT-PCR assays for these novel AstV clades are useful to identify and characterize the novel AstVs in environmental waters. PMID:25979884

  12. COPD and air travel: does hypoxia-altitude simulation testing predict in-flight respiratory symptoms?

    PubMed

    Edvardsen, Anne; Ryg, Morten; Akerø, Aina; Christensen, Carl Christian; Skjønsberg, Ole H

    2013-11-01

    The reduced pressure in an aircraft cabin may cause significant hypoxaemia and respiratory symptoms in patients with chronic obstructive pulmonary disease (COPD). The current study evaluated whether there is a relationship between hypoxaemia obtained during hypoxia-altitude simulation testing (HAST), simulating an altitude of 2438 m, and the reporting of respiratory symptoms during air travel. 82 patients with moderate to very severe COPD answered an air travel questionnaire. Arterial oxygen tensions during HAST (PaO2HAST) in subjects with and without in-flight respiratory symptoms were compared. The same questionnaire was answered within 1 year after the HAST. Mean ± sd PaO2HAST was 6.3 ± 0.6 kPa and 62 (76%) of the patients had PaO2HAST <6.6 kPa. 38 (46%) patients had experienced respiratory symptoms during air travel. There was no difference in PaO2HAST in those with and those without in-flight respiratory symptoms (6.3 ± 0.7 kPa versus 6.3 ± 0.6 kPa, respectively; p=0.926). 54 (66%) patients travelled by air after the HAST, and patients equipped with supplemental oxygen (n = 23, 43%) reported less respiratory symptoms when flying with than those without such treatment (four (17%) versus 11 (48%) patients; p=0.039). In conclusion, no difference in PaO2HAST was found between COPD patients with and without respiratory symptoms during air travel. PMID:23258777

  13. COPD and air travel: does hypoxia-altitude simulation testing predict in-flight respiratory symptoms?

    PubMed

    Edvardsen, Anne; Ryg, Morten; Akerø, Aina; Christensen, Carl Christian; Skjønsberg, Ole H

    2013-11-01

    The reduced pressure in an aircraft cabin may cause significant hypoxaemia and respiratory symptoms in patients with chronic obstructive pulmonary disease (COPD). The current study evaluated whether there is a relationship between hypoxaemia obtained during hypoxia-altitude simulation testing (HAST), simulating an altitude of 2438 m, and the reporting of respiratory symptoms during air travel. 82 patients with moderate to very severe COPD answered an air travel questionnaire. Arterial oxygen tensions during HAST (PaO2HAST) in subjects with and without in-flight respiratory symptoms were compared. The same questionnaire was answered within 1 year after the HAST. Mean ± sd PaO2HAST was 6.3 ± 0.6 kPa and 62 (76%) of the patients had PaO2HAST <6.6 kPa. 38 (46%) patients had experienced respiratory symptoms during air travel. There was no difference in PaO2HAST in those with and those without in-flight respiratory symptoms (6.3 ± 0.7 kPa versus 6.3 ± 0.6 kPa, respectively; p=0.926). 54 (66%) patients travelled by air after the HAST, and patients equipped with supplemental oxygen (n = 23, 43%) reported less respiratory symptoms when flying with than those without such treatment (four (17%) versus 11 (48%) patients; p=0.039). In conclusion, no difference in PaO2HAST was found between COPD patients with and without respiratory symptoms during air travel.

  14. 3. Historic American Buildings Survey California State Library Collection Sacramento ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Historic American Buildings Survey California State Library Collection Sacramento Co. History Thompson & West Sketch of 1880 Rephoto 1960 NORTHEAST CORNER - B. F. Hastings Bank Building, 128-132 J Street, Sacramento, Sacramento County, CA

  15. 3. VIEW OF WEST SIDE, SHOWING SECOND VERTICAL SUPPORT (SPAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW OF WEST SIDE, SHOWING SECOND VERTICAL SUPPORT (SPAN 1), CHANNELS, CROSS BRACING, AND CONNECTION DETAIL, LOOKING SOUTHWEST - McCann Road Bridge, Spanning Thornapple River at McCann Road, Hastings, Barry County, MI

  16. Plastic encapsulated parts

    SciTech Connect

    Castillo, T.

    1994-10-01

    Plastic semiconductor packages were characterized as possible alternatives for canned devices, which are susceptible to internal shorts caused by conductive particles. Highly accelerated stress testing (HAST) as well as electrical and mechanical testing were conducted on plastic technology devices.

  17. Geoscientists for international development

    USGS Publications Warehouse

    Hastings, David A.

    1980-01-01

    Professional societies are usually concerned with the advancement of scientific knowledge, but a relative newcomer to the international scene has a different focus - geoscience development in the Third World. David Hastings, a member of AGID, explains.

  18. 16. Photocopy of postcard (from Ardella Fish Shanks) Frank Stumm, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Photocopy of postcard (from Ardella Fish Shanks) Frank Stumm, photographer ca. 1908-16 SOUTH FRONT, HASTINGS HOUSE IN BACKGROUND - Riddell Fish House, 245 West K Street, Benicia, Solano County, CA

  19. Organ Transplantation

    MedlinePlus

    ... polls available at the moment. The Hastings Center Bioethics Briefing Book From Birth to Death and Bench ... Journalists, Policymakers, and Educators Close Table of Contents Bioethics and Policy—A History Daniel Callahan Why Bioethics ...

  20. 76 FR 80391 - Notice of Intent to Repatriate Cultural Items: U.S. Department of the Interior, National Park...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-23

    ... reservation. In 1922, Mr. Limpy and his wife traded or gifted the two items to Dr. Thomas B. Marquis, a.... Marquis' daughters, Mrs. Millie Ellen Marquis Hastings and Mrs. Anna Rose Octavia Marquis Heil....

  1. PTB Binds to the 3’ Untranslated Region of the Human Astrovirus Type 8: A Possible Role in Viral Replication

    PubMed Central

    Espinosa-Hernández, Wendy; Velez-Uriza, Dora; Valdés, Jesús; Vélez-Del Valle, Cristina; Salas-Benito, Juan; Martínez-Contreras, Rebeca; García-Espítia, Matilde; Salas-Benito, Mariana; Vega-Almeida, Tania; De Nova-Ocampo, Mónica

    2014-01-01

    The 3′ untranslated region (3′UTR) of human astroviruses (HAstV) consists of two hairpin structures (helix I and II) joined by a linker harboring a conserved PTB/hnRNP1 binding site. The identification and characterization of cellular proteins that interact with the 3′UTR of HAstV-8 virus will help to uncover cellular requirements for viral functions. To this end, mobility shift assays and UV cross-linking were performed with uninfected and HAstV-8-infected cell extracts and HAstV-8 3′UTR probes. Two RNA-protein complexes (CI and CII) were recruited into the 3′UTR. Complex CII formation was compromised with cold homologous RNA, and seven proteins of 35, 40, 45, 50, 52, 57/60 and 75 kDa were cross-linked to the 3′UTR. Supermobility shift assays indicated that PTB/hnRNP1 is part of this complex, and 3′UTR-crosslinked PTB/hnRNP1 was immunoprecipitated from HAstV-8 infected cell-membrane extracts. Also, immunofluorescence analyses revealed that PTB/hnRNP1 is distributed in the nucleus and cytoplasm of uninfected cells, but it is mainly localized perinuclearly in the cytoplasm of HAstV-8 infected cells. Furthermore, the minimal 3′UTR sequences recognized by recombinant PTB are those conforming helix I, and an intact PTB/hnRNP1-binding site. Finally, small interfering RNA-mediated PTB/hnRNP1 silencing reduced synthesis viral genome and virus yield in CaCo2 cells, suggesting that PTB/hnRNP1 is required for HAstV replication. In conclusion, PTB/hnRNP1 binds to the 3′UTR HAstV-8 and is required or participates in viral replication. PMID:25406089

  2. PTB binds to the 3' untranslated region of the human astrovirus type 8: a possible role in viral replication.

    PubMed

    Espinosa-Hernández, Wendy; Velez-Uriza, Dora; Valdés, Jesús; Vélez-Del Valle, Cristina; Salas-Benito, Juan; Martínez-Contreras, Rebeca; García-Espítia, Matilde; Salas-Benito, Mariana; Vega-Almeida, Tania; De Nova-Ocampo, Mónica

    2014-01-01

    The 3' untranslated region (3'UTR) of human astroviruses (HAstV) consists of two hairpin structures (helix I and II) joined by a linker harboring a conserved PTB/hnRNP1 binding site. The identification and characterization of cellular proteins that interact with the 3'UTR of HAstV-8 virus will help to uncover cellular requirements for viral functions. To this end, mobility shift assays and UV cross-linking were performed with uninfected and HAstV-8-infected cell extracts and HAstV-8 3'UTR probes. Two RNA-protein complexes (CI and CII) were recruited into the 3'UTR. Complex CII formation was compromised with cold homologous RNA, and seven proteins of 35, 40, 45, 50, 52, 57/60 and 75 kDa were cross-linked to the 3'UTR. Supermobility shift assays indicated that PTB/hnRNP1 is part of this complex, and 3'UTR-crosslinked PTB/hnRNP1 was immunoprecipitated from HAstV-8 infected cell-membrane extracts. Also, immunofluorescence analyses revealed that PTB/hnRNP1 is distributed in the nucleus and cytoplasm of uninfected cells, but it is mainly localized perinuclearly in the cytoplasm of HAstV-8 infected cells. Furthermore, the minimal 3'UTR sequences recognized by recombinant PTB are those conforming helix I, and an intact PTB/hnRNP1-binding site. Finally, small interfering RNA-mediated PTB/hnRNP1 silencing reduced synthesis viral genome and virus yield in CaCo2 cells, suggesting that PTB/hnRNP1 is required for HAstV replication. In conclusion, PTB/hnRNP1 binds to the 3'UTR HAstV-8 and is required or participates in viral replication.

  3. Human Astroviruses

    PubMed Central

    Pintó, Rosa M.; Guix, Susana

    2014-01-01

    SUMMARY Human astroviruses (HAtVs) are positive-sense single-stranded RNA viruses that were discovered in 1975. Astroviruses infecting other species, particularly mammalian and avian, were identified and classified into the genera Mamastrovirus and Avastrovirus. Through next-generation sequencing, many new astroviruses infecting different species, including humans, have been described, and the Astroviridae family shows a high diversity and zoonotic potential. Three divergent groups of HAstVs are recognized: the classic (MAstV 1), HAstV-MLB (MAstV 6), and HAstV-VA/HMO (MAstV 8 and MAstV 9) groups. Classic HAstVs contain 8 serotypes and account for 2 to 9% of all acute nonbacterial gastroenteritis in children worldwide. Infections are usually self-limiting but can also spread systemically and cause severe infections in immunocompromised patients. The other groups have also been identified in children with gastroenteritis, but extraintestinal pathologies have been suggested for them as well. Classic HAstVs may be grown in cells, allowing the study of their cell cycle, which is similar to that of caliciviruses. The continuous emergence of new astroviruses with a potential zoonotic transmission highlights the need to gain insights on their biology in order to prevent future health threats. This review focuses on the basic virology, pathogenesis, host response, epidemiology, diagnostic assays, and prevention strategies for HAstVs. PMID:25278582

  4. Prevalence and Genetic Diversity of Human Astroviruses in Mexican Children with Symptomatic and Asymptomatic Infections

    PubMed Central

    Méndez-Toss, Martha; Griffin, Dixie D.; Calva, Juan; Contreras, Juan F.; Puerto, Fernando I.; Mota, Felipe; Guiscafré, Héctor; Cedillo, Roberto; Muñoz, Onofre; Herrera, Ismael; López, Susana; Arias, Carlos F.

    2004-01-01

    The prevalence and type diversity of human astroviruses (HAstV) in children with symptomatic and asymptomatic infections were determined in five localities of Mexico. HAstV were detected in 4.6 (24 of 522) and 2.6% (11 of 428) of children with and without diarrhea, respectively. Genotyping of the detected strains showed that at least seven (types 1 to 4 and 6 to 8) of the eight known HAstV types circulated in Mexico between October 1994 and March 1995. HAstV types 1 and 3 were the most prevalent in children with diarrhea, although they were not found in all localities studied. HAstV type 8 was found in Mexico City, Monterrey, and Mérida; in the last it was as prevalent (40%) as type 1 viruses, indicating that this astrovirus type is more common than previously recognized. A correlation between the HAstV infecting type and the presence or absence of diarrheic symptoms was not observed. Enteric adenoviruses were also studied, and they were found to be present in 2.3 (12 of 522) and 1.4% (6 of 428) of symptomatic and asymptomatic children, respectively. PMID:14715746

  5. Full sequence analysis and characterization of a human astrovirus type 1 isolate from South Korea.

    PubMed

    Lee, Sung-Geun; Kang, Lae-Hyung; Jheong, Weon-Hwa; Oh, Mi-Hwa; Lee, Gyu-Cheol; Park, Sujeong; Paik, Soon-Young

    2013-02-01

    Human astroviruses are recognized as an important cause of infantile gastroenteritis around the world. In South Korea, sporadic cases of HAstV infection have been reported since 2002. However, hitherto, there have been no studies reporting the whole genome sequence of an HAstV isolate from South Korea. Hence, we sequenced and analyzed the entire genome of an HAstV-1 strain (lhar) that was isolated in Seoul, South Korea. The whole-genome sequence analysis revealed 3 open reading frames comprising the whole genome: ORF1a (2,763 bp), ORF1b (1,548 bp), and ORF2 (2,364 bp). The lhar strain showed amino acid identities with 8 other reference strains of 87.6-98.7%, 94.2-98.8%, and 62.6-99.0% in the ORF1a, ORF1b, and ORF2 regions, respectively. The amino acid sequence of the capsid region encoded by ORF2 was compared with a total of 19 HAstV-1 strains and 8 HAstVs reference strains isolated in various countries. This revealed 1 amino acid substitution, at aa412 (Pro → Arg) in ORF2. This study, the first to report the full-length sequence of an HAstV isolated in South Korea, is meaningful in that it can be used as a full-length HAstV sequence standard for future comparison studies. It may also prove useful to the field of public health field by facilitating the diagnosis and the prediction of new emerging variants.

  6. Business ethics in ethics committees?

    PubMed

    Boyle, P

    1990-01-01

    The "Ethics committees" column in this issue of the Hastings Center Report features an introduction by Cynthia B. Cohen and four brief commentaries on the roles hospital ethics committees may play in the making of institutional and public health care policy in the 1990s. The pros and cons of a broader, more public role for ethics committees in reconciling the business and patient care aspects of health care delivery are debated by Cohen in "Ethics committees as corporate and public policy advocates," and by Philip Boyle in this article. Boyle is an associate for ethical studies at The Hastings Center.

  7. Crystal Structure of the Human Astrovirus Capsid Protein

    PubMed Central

    Toh, Yukimatsu; Harper, Justin; Dryden, Kelly A.; Yeager, Mark; Méndez, Ernesto

    2016-01-01

    ABSTRACT Human astrovirus (HAstV) is a leading cause of viral diarrhea in infants and young children worldwide. HAstV is a nonenveloped virus with a T=3 capsid and a positive-sense RNA genome. The capsid protein (CP) of HAstV is synthesized as a 90-kDa precursor (VP90) that can be divided into three linear domains: a conserved N-terminal domain, a hypervariable domain, and an acidic C-terminal domain. Maturation of HAstV requires proteolytic processing of the astrovirus CP both inside and outside the host cell, resulting in the removal of the C-terminal domain and the breakdown of the rest of the CP into three predominant protein species with molecular masses of ∼34, 27/29, and 25/26 kDa, respectively. We have now solved the crystal structure of VP9071–415 (amino acids [aa] 71 to 415 of VP90) of human astrovirus serotype 8 at a 2.15-Å resolution. VP9071–415 encompasses the conserved N-terminal domain of VP90 but lacks the hypervariable domain, which forms the capsid surface spikes. The structure of VP9071–415 is comprised of two domains: an S domain, which adopts the typical jelly-roll β-barrel fold, and a P1 domain, which forms a squashed β-barrel consisting of six antiparallel β-strands similar to what was observed in the hepatitis E virus (HEV) capsid structure. Fitting of the VP9071–415 structure into the cryo-electron microscopy (EM) maps of HAstV produced an atomic model for a continuous, T=3 icosahedral capsid shell. Our pseudoatomic model of the human HAstV capsid shell provides valuable insights into intermolecular interactions required for capsid assembly and trypsin-mediated proteolytic maturation needed for virus infectivity. Such information has potential applications in the development of a virus-like particle (VLP) vaccine as well as small-molecule drugs targeting astrovirus assembly/maturation. IMPORTANCE Human astrovirus (HAstV) is a leading cause of viral diarrhea in infants and young children worldwide. As a nonenveloped virus

  8. MathBench Biology Modules: Web-Based Math for All Biology Undergraduates

    ERIC Educational Resources Information Center

    Nelson, Karen C.; Marbach-Ad, Gili; Schneider, Katie; Thompson, Katerina V.; Shields, Patricia A.; Fagan, William F.

    2009-01-01

    Historically, biology has not been a heavily quantitative science, but this is changing rapidly (Ewing 2002; Gross 2000; Hastings and palmer 2003; Jungck 2005; Steen 2005). Quantitative approaches now constitute a key tool for modern biologists, yet undergraduate biology courses remain largely qualitative and descriptive. Although biology majors…

  9. Action Items

    ERIC Educational Resources Information Center

    Baker, Mark; Keane, Brian

    2009-01-01

    Maximizing school resources and managing a shrinking budget--these are two important items affected when a building's roofing system does not perform properly. Rather than acting in haste, school and university administrators should do what every teacher tells a student prior to answering any question: think through the research and studies to…

  10. Their Spirits Live within Us: Aboriginal Women in Downtown Eastside Vancouver Emerging into Visibility

    ERIC Educational Resources Information Center

    Culhane, Dara

    2003-01-01

    The intersection of Main and Hastings streets--known locally as "Pain and Wastings"--marks the heart of Vancouver's inner-city neighborhood: the Downtown Eastside. Since 1997, when the City of Vancouver Health Department declared a public health emergency in response to reports that HIV infection rates among residents exceeded those anywhere else…

  11. The Brave New World of the Interim Superintendency

    ERIC Educational Resources Information Center

    Bigham, Gary D.

    2011-01-01

    Considering the vital role the superintendent plays in the overall functioning and well-being of any school district, the filling of the top leadership post with a permanent appointment never should be done in haste. The process of advertising, reviewing applications, conducting background checks, interviewing candidates, negotiating contracts,…

  12. Analyzing the Participatory Repertoire of a U.S. Educated EFL Teacher in Saudi Arabia

    ERIC Educational Resources Information Center

    Lee-Johnson, Yin Lam

    2016-01-01

    The KSA has become a popular country for Americans to work as an EFL teacher in the recent years because of the payment and cultural experience (Hastings, 2012). Due to the wide social distance between the KSA and USA, the teachers had to adapt to the expectation and become legitimate participants (Lave and Wenger, 1991) in the local communities.…

  13. Ethical issues surrounding quality improvement activities: a review.

    PubMed

    Wise, Lowell C

    2007-06-01

    During the past 15 years, issues regarding the ethical conduct of quality improvement activities have emerged. Recently, many have called for regulation of quality improvement studies using institutional review boards. The author reviews the history of the human rights argument within the context of a relevant, newly released study by the Hastings Center and concludes with practical application of the study's findings.

  14. Comparing Three Estimation Methods for the Three-Parameter Logistic IRT Model

    ERIC Educational Resources Information Center

    Lamsal, Sunil

    2015-01-01

    Different estimation procedures have been developed for the unidimensional three-parameter item response theory (IRT) model. These techniques include the marginal maximum likelihood estimation, the fully Bayesian estimation using Markov chain Monte Carlo simulation techniques, and the Metropolis-Hastings Robbin-Monro estimation. With each…

  15. First North American record of the Palearctic Microplax albofasciata (Costa) (Hemiptera: Lygaeoidea: Oxycarenidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microplax albofasciata (Costa), a Palearctic (mainly Mediterranean) species of the small family Oxycarenidae, is reported from California as the first record for the New World. Adults of this little-known lygaeoid bug were found in 2012 and 2013 at the Hastings Natural History Reservation in norther...

  16. The Emotional Reactions to Challenging Behavior Scale-Korean (ERCBS-K): Modification and Validation

    ERIC Educational Resources Information Center

    Oh, Hyun-Kyoung; Seo, Dong-Chul; Kozub, Francis M.

    2010-01-01

    The purpose of this study was to explore the original version of Mitchell and Hastings's (1998) Emotional Reaction to Challenging Behavior Scale (ERCBS) and estimate validity and reliability of a revised version containing 29 items. The Emotional Reaction to Challenging Behavior Scale-Korean (ERCBS-K) was studied using 445 in-service physical…

  17. Andreas Vesalius--the work.

    PubMed

    Cobolet, Guy; Garrison, Dan; Vons, Jacqueline; Velut, Stéphane; Nutton, Vivian; Williams, David J

    2014-01-01

    This session focuses on the Fabrica (1543). Karger Publishers of Basel are producing a new English translation, by Daniel Garrison and Malcom Hast, to coincide with the quincentenary while Vivian Nutton's scholarly analysis of a newly discovered second edition indicates that the annotations are of Vesalius himself. PMID:25181777

  18. Summary of Higher Education Accountability Statutes in Other States. OP/04-04

    ERIC Educational Resources Information Center

    California Postsecondary Education Commission, 2004

    2004-01-01

    The Public Law Research Institute at the University of California Hastings College of the Law, with whom the California Postsecondary Education Commission (CPEC) forged a partnership to research, analyze, and make sound recommendations regarding an accountability structure, provides an excellent opportunity for CPEC regarding federal and state…

  19. Stochastic Approximation Methods for Latent Regression Item Response Models

    ERIC Educational Resources Information Center

    von Davier, Matthias; Sinharay, Sandip

    2010-01-01

    This article presents an application of a stochastic approximation expectation maximization (EM) algorithm using a Metropolis-Hastings (MH) sampler to estimate the parameters of an item response latent regression model. Latent regression item response models are extensions of item response theory (IRT) to a latent variable model with covariates…

  20. LEACHING BOUNDARY IN CEMENT-BASED WASTE FORMS

    EPA Science Inventory

    Cement-based fixation systems are among the most commonly employed stabilization/solidification techniques. These cement haste mixtures, however, are vulnerable to ardic leaching solutions. Leaching of cement-based waste forms in acetic acid solutions with different acidic streng...

  1. Bayesian Analysis of Nonlinear Structural Equation Models with Nonignorable Missing Data

    ERIC Educational Resources Information Center

    Lee, Sik-Yum

    2006-01-01

    A Bayesian approach is developed for analyzing nonlinear structural equation models with nonignorable missing data. The nonignorable missingness mechanism is specified by a logistic regression model. A hybrid algorithm that combines the Gibbs sampler and the Metropolis-Hastings algorithm is used to produce the joint Bayesian estimates of…

  2. 78 FR 41923 - National Advisory Committee on Institutional Quality and Integrity; Notice of Committee Membership

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-12

    .... Wu, J.D., Chancellor and Dean, UC Hastings College of Law Dr. Federico Zaragoza, Vice Chancellor of... (Terms Expire 9/ 30/14) Dr. George T. French, President, Miles College Dr. Arthur E. Keiser, Chancellor, Keiser University Dr. William (Brit) E. Kirwan, Chancellor, University System of Maryland Dr....

  3. 78 FR 295 - National Advisory Committee on Institutional Quality and Integrity: Notice of Membership

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-03

    ..., NY. Frank H. Wu, J.D., Chancellor and Dean, University of California, Hastings College of the Law, San Francisco, California. Federico Zaragoza, Ph.D., Vice Chancellor of Economic and Workforce... Keiser, Ph.D., Chancellor, Keiser University, Fort Lauderdale, Florida. William E. Kirwan,...

  4. The Effect of an Integrative Parent Education Program on Quality of Life for Families of Children with an Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    White, Caroline Jane

    2010-01-01

    Families of children with an Autism Spectrum Disorder (ASD) exhibit decreases in cohesion and adaptability, increased social isolation (Higgins et al., 2005), higher levels of marital dissatisfaction (Hastings et al., 2005), and overall disruption to daily life (Bristol et al., 1988). Research has provided evidence of higher levels of stress,…

  5. [Construction and expression of six deletion mutants of human astrovirus C-terminal nsP1a/4 protein].

    PubMed

    Zhao, Wei; Niu, Ke; Zhao, Jian; Jin, Yi-ming; Sui, Ting-ting; Wang, Wen

    2013-09-01

    Human astrovirus (HAstV) is one of the leading causes of actue virual diarrhea in infants. HAstV-induced epithdlial cell apoptosis plays an important role in the pathogenesis of HAstV infection. Our previous study indicated that HAstV non-structural protein nsPla C-terminal protein nsPla/4 was the major apoptosis functional protein and probably contained the main apoptosis domains. In order to screen for astrovirus encoded apoptotic protien, nsPla/4 and six turncated proteins, which possessed nsPla/4 protein different function domain ,were cloned into green fluorescent protein (GFP) vector pEG-FP-N3. After 24-72 h transfection, the fusion protein expression in BHK21 cells, was analysis by fluorescence microscope and Western blot. The results indicated seven fusion proteins were observed successfully in BHK21 cell after transfected for 24 h. Western blot analysis showed that the level of fusion protein expressed in BHK21 cells was increased significantly at 72h compared to 48h in transfected cells. The successful expression of deletion mutants of nsPla/4 protein was an important foundation to gain further insights into the function of apoptosis domains of nsPla/4 protein and it would also provide research platform to further confirm the molecule pathogenic mechanism of human astrovirus.

  6. Effective Collaboration Among Health Care and Education Professionals: A Necessary Condition for Successful Early Intervention in Rural Areas. Making It Work in Rural Communities. A Rural Network Monograph.

    ERIC Educational Resources Information Center

    Smith-Dickson, Bonnie, Ed.; Hutinger, Patricia, Ed.

    Addressing the lack of cooperation between early intervention programs and the rural health community, this monograph presents eight papers by educators and health professionals who identify specific problems and offer solutions in the form of effective collaboration techniques and model programs. Papers by Susan Hastings and Stewart Gabel…

  7. 4. VIEW OF WEST SIDE, SHOWING CENTER 'V' CONNECTIONS, CHANNELS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW OF WEST SIDE, SHOWING CENTER 'V' CONNECTIONS, CHANNELS AND CROSSING BRACING DETAIL ON SPAN 1 AND BACK OF DIAGONAL SUPPORT ON SPAN 2, LOOKING NORTHWEST - McCann Road Bridge, Spanning Thornapple River at McCann Road, Hastings, Barry County, MI

  8. The Teaching of Ethics. Vol. 1-9.

    ERIC Educational Resources Information Center

    1980

    The state of ethics teaching at the undergraduate and professional school levels is examined in these comprehensive monographs sponsored by the Institute of Society, Ethics and the Life Sciences/The Hastings Center. "The Teaching of Ethics in Higher Education (I)" encompasses: (1) the number and extent of courses in ethics, (2) the status and…

  9. Acceleration of degradation by highly accelerated stress test and air-included highly accelerated stress test in crystalline silicon photovoltaic modules

    NASA Astrophysics Data System (ADS)

    Suzuki, Soh; Tanahashi, Tadanori; Doi, Takuya; Masuda, Atsushi

    2016-02-01

    We examined the effects of hyper-hygrothermal stresses with or without air on the degradation of crystalline silicon (c-Si) photovoltaic (PV) modules, to shorten the required duration of a conventional hygrothermal-stress test [i.e., the “damp heat (DH) stress test”, which is conducted at 85 °C/85% relative humidity for 1,000 h]. Interestingly, the encapsulant within a PV module becomes discolored under the air-included hygrothermal conditions achieved using DH stress test equipment and an air-included highly accelerated stress test (air-HAST) apparatus, but not under the air-excluded hygrothermal conditions realized using a highly accelerated stress test (HAST) machine. In contrast, the reduction in the output power of the PV module is accelerated irrespective of air inclusion in hyper-hygrothermal test atmosphere. From these findings, we conclude that the required duration of the DH stress test will at least be significantly shortened using air-HAST, but not HAST.

  10. VIEW OF PIEDMONT AVENUE NORTH OF DWIGHT WAY. INTERSECTION OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF PIEDMONT AVENUE NORTH OF DWIGHT WAY. INTERSECTION OF HASTE STREET SEEN AT CENTER DISTANCE. SEEN FROM WEST SIDE OF PIEDMONT AVE. LOOKING NORTH. Photograph by Fredrica Drotos and Michael Kelly, July 8, 2006 - Piedmont Way & the Berkeley Property Tract, East of College Avenue between Dwight Way & U.C. Memorial Stadium, Berkeley, Alameda County, CA

  11. The Psychometric Properties of the Difficult Behavior Self-Efficacy Scale

    ERIC Educational Resources Information Center

    Oh, Hyun-Kyoung; Kozub, Francis M.

    2010-01-01

    The study was designed to estimate the psychometric properties of Hastings and Brown's (2002a) Difficult Behavior Self-efficacy Scale. Participants were two samples of physical educators teaching in Korea (n = 229) and the United States (U.S.; n = 139). An initial translation of the questionnaire to Korean and pilot study were conducted along with…

  12. 2. AERIAL VIEW SHOWING AQUEDUCT RIGHTOFWAY PASSING OVER RAILROAD LINE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. AERIAL VIEW SHOWING AQUEDUCT RIGHT-OF-WAY PASSING OVER RAILROAD LINE FROM STONE QUARRY. TRACKS ARE GONE BUT RIGHT-OF-WAY IS STILL VISIBLE. - Old Croton Aqueduct, Quarry Railroad Bridge, Aqueduct Lane at Williams Street, Hastings-on-Hudson, Westchester County, NY

  13. 76 FR 3092 - Endangered Species Permit No. 1578-01 and Permit No. 1595-04

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-19

    ... 24, 2010, notice was published in the Federal Register (75 FR 58350) that a request for an amendment... (Permit No. 1578); and Michael M. Hastings, University of Maine, 5717 Corbett Hall, Orono, ME 04469.... Dated: January 12, 2011. P. Michael Payne, Chief, Permits, Conservation and Education Division,...

  14. Evolutionary outcomes should inform plant breeding and transgenic approaches to drought tolerance in crop species: the importance of xylem traits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genomic-assisted breeding and transgenic approaches to crop improvement are presently targeting phenotypic traits that allegedly confer drought tolerance. A news feature published in Nature Biotechnology last year suggests that these efforts may not be proceeding with sufficient haste, considering t...

  15. "Reading" Mixed Methods Research: Contexts for Criticism

    ERIC Educational Resources Information Center

    Freshwater, Dawn

    2007-01-01

    Health and social care researchers, in their haste to "belong" to academia, have adopted the system of mixed methodology research, overestimating its ability to reveal the truth and occasionally imprisoning their thought in one system. In this article, some of the assumptions underpinning mixed methodology research and its discourse are subjected…

  16. Extended Mixed-Efects Item Response Models with the MH-RM Algorithm

    ERIC Educational Resources Information Center

    Chalmers, R. Philip

    2015-01-01

    A mixed-effects item response theory (IRT) model is presented as a logical extension of the generalized linear mixed-effects modeling approach to formulating explanatory IRT models. Fixed and random coefficients in the extended model are estimated using a Metropolis-Hastings Robbins-Monro (MH-RM) stochastic imputation algorithm to accommodate for…

  17. Andreas Vesalius--the work.

    PubMed

    Cobolet, Guy; Garrison, Dan; Vons, Jacqueline; Velut, Stéphane; Nutton, Vivian; Williams, David J

    2014-01-01

    This session focuses on the Fabrica (1543). Karger Publishers of Basel are producing a new English translation, by Daniel Garrison and Malcom Hast, to coincide with the quincentenary while Vivian Nutton's scholarly analysis of a newly discovered second edition indicates that the annotations are of Vesalius himself.

  18. The Experience of a Man with Severe Challenging Behaviour Following Resettlement from Hospital: A Single Case Design

    ERIC Educational Resources Information Center

    Bissell, Lianne; Phillips, Neil; Kroese, Biza Stenfert

    2005-01-01

    Carers' behaviour is thought to contribute to the development and maintenance of challenging behaviour in people with learning disabilities (Emerson et al. 1995; Hastings & Remington 1994). The present study sought to investigate the effectiveness of a behavioural intervention in the management of such problem behaviours by means of a long-term…

  19. Making Art Invisible: Visual Education and the Cultural Stagnation of Neo-Liberal Rationality

    ERIC Educational Resources Information Center

    Peers, Chris

    2011-01-01

    The popularity of visual literacy may have resulted, in part, from some school authorities rushing the process of determining school curriculum. This article argues that the haste is reflective of pressure placed on educational discourse to conform to neo-liberal reforms of the sector, and is not the result of a careful and complex debate within…

  20. 76 FR 80388 - Notice of Intent to Repatriate Cultural Items: U.S. Department of the Interior, National Park...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-23

    ..., who resided on the Northern Cheyenne Reservation. In 1922, Dr. Thomas B. Marquis, a physician on the..., now known as Little Bighorn Battlefield National Monument, by Dr. Marquis' daughters, Mrs. Millie Ellen Marquis Hastings and Mrs. Anna Rose Octavia Marquis Heil. The two cultural items described...

  1. The reliability of a heat acclimation state test prescribed from metabolic heat production intensities.

    PubMed

    Willmott, A G B; Hayes, M; Dekerle, J; Maxwell, N S

    2015-10-01

    Acclimation state indicates an individual's phenotypic response to a thermally stressful environment, where changes in heat dissipation capacity are determined during a heat acclimation state test (HAST). Variations in thermoregulatory and sudomotor function are reported while exercising at intensities relative to maximal oxygen uptake. This inter-individual variation is not true when intensity is prescribed to elicit a fixed rate of metabolic heat production (Ḣprod). This study investigated the reliability of peak Tre and two composite measures (sweat gain and sweat setpoint) derived from indices of thermosensitivity during a HAST prescribed from Ḣprod intensities. Fourteen participants (mean±SD; age 23±3 years, stature 174±7cm, body mass 75.0±9.4kg, body surface area 1.9±0.1m(2), peak oxygen consumption [V̇O2peak] 3.49±0.53Lmin(-1)) completed a lactate threshold-V̇O2peak test and two duplicate Ḣprod HASTs on a cycle ergometer. The HAST consisted of three, 30-min periods of exercise at fixed Ḣprod intensities relative to body mass (3, 4.5 and 6Wkg(-1)), within hot dry conditions (44.7±1.8°C and 18.1±4.7% relative humidity). Peak Tre (38.20±0.36 vs. 38.16±0.42°C, p=0.54), sweat setpoint (36.76±0.34 and 36.79±0.38°C, p=0.68) and sweat gain (0.37±0.14 and 0.40±0.18gs(-1)°C(-1), p=0.40) did not differ between HASTs. Typical error of measurement (TEM), coefficient variation (CV) and intra-class coefficient of correlation (ICC) were 0.19°C, 0.5% and 0.80 for peak Tre, 0.21°C, 0.6% and 0.65 for sweat setpoint and 0.09gs(-1)°C(-1), 28% and 0.68 for sweat gain, respectively. The use of fixed Ḣprod intensities relative to body mass is a reliable method for measuring Tre and ascertaining sweat setpoint during a HAST, whereas, sweat gain displays greater variability. A Ḣprod HAST appears sufficiently reliable for quantifying heat acclimation state, where TEM in peak Tre and sweat setpoint are small enough to identify physiologically

  2. Initiation of human astrovirus type 1 infection was blocked by inhibitors of phosphoinositide 3-kinase

    PubMed Central

    2013-01-01

    Background Upon initial contact with a virus, host cells activate a series of cellular signaling cascades that facilitate viral entry and viral propagation within the cell. Little is known about how the human astrovirus (HAstV) exploits signaling cascades to establish an infection in host cells. Recent studies showed that activation of extracellular signal-regulated kinase 1/2 (ERK1/2) is important for HAstV infection, though the involvement of other signaling cascades remains unclear. Methods A panel of kinase blockers was used to search for cellular signaling pathways important for HAstV1 infection. To determine their impact on the infectious process, we examined viral gene expression, RNA replication, and viral RNA and capsid protein release from host cells. Results Inhibitors of phosphoinositide 3-kinase (PI3K) activation interfered with the infection, independent of their effect on ERK 1/2 activation. Activation of the PI3K signaling cascade occurred at an early phase of the infection, judging from the timeframe of Akt phosphorylation. PI3K inhibition at early times, but not at later times, blocked viral gene expression. However, inhibiting the downstream targets of PI3K activation, Akt and Rac1, did not block infection. Inhibition of protein kinase A (PKA) activation was found to block a later phase of HAstV1 production. Conclusions Our results reveal a previously unknown, essential role of PI3K in the life cycle of HAstV1. PI3K participates in the early stage of infection, possibly during the viral entry process. Our results also reveal the role of PKA in viral production. PMID:23680019

  3. Revisiting Additivity Violation of Quantum Channels

    NASA Astrophysics Data System (ADS)

    Fukuda, Motohisa

    2014-12-01

    We prove additivity violation of minimum output entropy of quantum channels by straightforward application of -net argument and Lévy's lemma. The additivity conjecture was disproved initially by Hastings. Later, a proof via asymptotic geometric analysis was presented by Aubrun, Szarek and Werner, which uses Dudley's bound on Gaussian process (or Dvoretzky's theorem with Schechtman's improvement). In this paper, we develop another proof along Dvoretzky's theorem in Milman's view, showing additivity violation in broader regimes than the existing proofs. Importantly,Dvoretzky's theorem works well with norms to give strong statements, but these techniques can be extended to functions which have norm-like structures-positive homogeneity and triangle inequality. Then, a connection between Hastings' method and ours is also discussed. In addition, we make some comments on relations between regularized minimum output entropy and classical capacity of quantum channels.

  4. Learning about Teaching.

    PubMed

    Kaebnick, Gregory E

    2014-09-01

    There are three broad themes in this issue of the Hastings Center Report. First, a special report published as a supplement to the issue addresses the medical and health policy issues faced by lesbian, gay, bisexual, and transgender patients. Inside the issue, the two articles take up questions about how caregivers may justify a refusal to provide a medical service that a patient has requested. The issue also contains a set of essays that have emerged from a collaborative effort by The Hastings Center and the Presidential Commission for the Study of Bioethical Issues to promote scholarly engagement with the practical problem of teaching caregivers, researchers, scientists, and others to address bioethical problems. What appears here is the first installment of a series that will appear in the pages of the Report well into the 2015 volume. PMID:25231650

  5. Type I Interferon Response Limits Astrovirus Replication and Protects against Increased Barrier Permeability In Vitro and In Vivo

    PubMed Central

    Marvin, Shauna A.; Huerta, C. Theodore; Sharp, Bridgett; Freiden, Pamela

    2015-01-01

    ABSTRACT Little is known about intrinsic epithelial cell responses against astrovirus infection. Here we show that human astrovirus type 1 (HAstV-1) infection induces type I interferon (beta interferon [IFN-β]) production in differentiated Caco2 cells, which not only inhibits viral replication by blocking positive-strand viral RNA and capsid protein synthesis but also protects against HAstV-1-increased barrier permeability. Excitingly, we found similar results in vivo using a murine astrovirus (MuAstV) model, providing new evidence that virus-induced type I IFNs may protect against astrovirus replication and pathogenesis in vivo. IMPORTANCE Human astroviruses are a major cause of pediatric diarrhea, yet little is known about the immune response. Here we show that type I interferon limits astrovirus infection and preserves barrier permeability both in vitro and in vivo. Importantly, we characterized a new mouse model for studying astrovirus replication and pathogenesis. PMID:26656701

  6. The psychology of autonomy.

    PubMed

    2016-05-01

    In May 2016, right around the time that this issue of the Hastings Center Report should be published, The Hastings Center is holding a conference in New York City titled "Bioethics Meets Moral Psychology." The goal of the conference is to consider the lessons that bioethicists should learn from the raft of literature now accumulating on how the mental processes of perception, emotion, and thinking affect things that bioethicists care about, from the education of health care professionals to the conflicts that arise in clinical care, the "culture wars" over bioethical policy issues, the status of different cultures' value systems, and the very understanding of the values that are foundational in moral thinking. The articles in this issue simply provide more evidence that bioethics is meeting moral psychology. PMID:27150409

  7. Assessment of gastroenteric viruses from wastewater directly discharged into Uruguay River, Uruguay.

    PubMed

    Victoria, M; Tort, L F L; García, M; Lizasoain, A; Maya, L; Leite, J P G; Miagostovich, M P; Cristina, J; Colina, R

    2014-06-01

    The aim of this study was to assess the viral contamination of group A rotavirus (RVA), norovirus (NoV), and human astrovirus (HAstV) in sewage directly discharged into Uruguay River and to characterize RVA genotypes circulating in Uruguay. For this purpose, sewage samples (n = 96) were collected biweekly from March 2011 to February 2012 in four Uruguayan cities: Bella Unión, Salto, Paysandú, and Fray Bentos. Each sample was concentrated by ultracentrifugation method. Qualitative and quantitative RT-PCR for RVA, NoV, and HAstV were performed. A wide dissemination of gastroenteric viruses was observed in the sewage samples analyzed with 80% of positivity, being NoV (51%) the most frequently detected followed by RVA with a frequency of 49% and HAstV with 45%. Genotypes of RVA were typed using multiplex semi-nested RT-PCR as follows: P[8] (n = 15), P[4] (n = 8), P[10] (n = 1), P[11] (n = 1), G2 (n = 29), and G3 (n = 2). The viral load ranged from 10(3) to 10(7) genomic copies/liter, and they were detected roughly with the same frequency in all participant cities. A peak of RVA and HAstV detection was observed in colder months (June to September), whereas no seasonality was observed for NoV. This study demonstrates for the first time, the high degree of gastroenteric viral contamination in the country; highlighting the importance of developing these analyses as a tool to determine the viral contamination in this hydrographic boundary region used by the local populations for recreation and consumption, establishing an elevated risk of gastroenteric diseases for human health. PMID:24777819

  8. Deciphering the Diversities of Astroviruses and Noroviruses in Wastewater Treatment Plant Effluents by a High-Throughput Sequencing Method.

    PubMed

    Prevost, B; Lucas, F S; Ambert-Balay, K; Pothier, P; Moulin, L; Wurtzer, S

    2015-10-01

    Although clinical epidemiology lists human enteric viruses to be among the primary causes of acute gastroenteritis in the human population, their circulation in the environment remains poorly investigated. These viruses are excreted by the human population into sewers and may be released into rivers through the effluents of wastewater treatment plants (WWTPs). In order to evaluate the viral diversity and loads in WWTP effluents of the Paris, France, urban area, which includes about 9 million inhabitants (approximately 15% of the French population), the seasonal occurrence of astroviruses and noroviruses in 100 WWTP effluent samples was investigated over 1 year. The coupling of these measurements with a high-throughput sequencing approach allowed the specific estimation of the diversity of human astroviruses (human astrovirus genotype 1 [HAstV-1], HAstV-2, HAstV-5, and HAstV-6), 7 genotypes of noroviruses (NoVs) of genogroup I (NoV GI.1 to NoV GI.6 and NoV GI.8), and 16 genotypes of NoVs of genogroup II (NoV GII.1 to NoV GII.7, NoV GII.9, NoV GII.12 to NoV GII.17, NoV GII.20, and NoV GII.21) in effluent samples. Comparison of the viral diversity in WWTP effluents to the viral diversity found by analysis of clinical data obtained throughout France underlined the consistency between the identified genotypes. However, some genotypes were locally present in effluents and were not found in the analysis of the clinical data. These findings could highlight an underestimation of the diversity of enteric viruses circulating in the human population. Consequently, analysis of WWTP effluents could allow the exploration of viral diversity not only in environmental waters but also in a human population linked to a sewerage network in order to better comprehend viral epidemiology and to forecast seasonal outbreaks.

  9. Deciphering the Diversities of Astroviruses and Noroviruses in Wastewater Treatment Plant Effluents by a High-Throughput Sequencing Method

    PubMed Central

    Prevost, B.; Lucas, F. S.; Ambert-Balay, K.; Pothier, P.; Wurtzer, S.

    2015-01-01

    Although clinical epidemiology lists human enteric viruses to be among the primary causes of acute gastroenteritis in the human population, their circulation in the environment remains poorly investigated. These viruses are excreted by the human population into sewers and may be released into rivers through the effluents of wastewater treatment plants (WWTPs). In order to evaluate the viral diversity and loads in WWTP effluents of the Paris, France, urban area, which includes about 9 million inhabitants (approximately 15% of the French population), the seasonal occurrence of astroviruses and noroviruses in 100 WWTP effluent samples was investigated over 1 year. The coupling of these measurements with a high-throughput sequencing approach allowed the specific estimation of the diversity of human astroviruses (human astrovirus genotype 1 [HAstV-1], HAstV-2, HAstV-5, and HAstV-6), 7 genotypes of noroviruses (NoVs) of genogroup I (NoV GI.1 to NoV GI.6 and NoV GI.8), and 16 genotypes of NoVs of genogroup II (NoV GII.1 to NoV GII.7, NoV GII.9, NoV GII.12 to NoV GII.17, NoV GII.20, and NoV GII.21) in effluent samples. Comparison of the viral diversity in WWTP effluents to the viral diversity found by analysis of clinical data obtained throughout France underlined the consistency between the identified genotypes. However, some genotypes were locally present in effluents and were not found in the analysis of the clinical data. These findings could highlight an underestimation of the diversity of enteric viruses circulating in the human population. Consequently, analysis of WWTP effluents could allow the exploration of viral diversity not only in environmental waters but also in a human population linked to a sewerage network in order to better comprehend viral epidemiology and to forecast seasonal outbreaks. PMID:26253673

  10. Assessment of gastroenteric viruses from wastewater directly discharged into Uruguay River, Uruguay.

    PubMed

    Victoria, M; Tort, L F L; García, M; Lizasoain, A; Maya, L; Leite, J P G; Miagostovich, M P; Cristina, J; Colina, R

    2014-06-01

    The aim of this study was to assess the viral contamination of group A rotavirus (RVA), norovirus (NoV), and human astrovirus (HAstV) in sewage directly discharged into Uruguay River and to characterize RVA genotypes circulating in Uruguay. For this purpose, sewage samples (n = 96) were collected biweekly from March 2011 to February 2012 in four Uruguayan cities: Bella Unión, Salto, Paysandú, and Fray Bentos. Each sample was concentrated by ultracentrifugation method. Qualitative and quantitative RT-PCR for RVA, NoV, and HAstV were performed. A wide dissemination of gastroenteric viruses was observed in the sewage samples analyzed with 80% of positivity, being NoV (51%) the most frequently detected followed by RVA with a frequency of 49% and HAstV with 45%. Genotypes of RVA were typed using multiplex semi-nested RT-PCR as follows: P[8] (n = 15), P[4] (n = 8), P[10] (n = 1), P[11] (n = 1), G2 (n = 29), and G3 (n = 2). The viral load ranged from 10(3) to 10(7) genomic copies/liter, and they were detected roughly with the same frequency in all participant cities. A peak of RVA and HAstV detection was observed in colder months (June to September), whereas no seasonality was observed for NoV. This study demonstrates for the first time, the high degree of gastroenteric viral contamination in the country; highlighting the importance of developing these analyses as a tool to determine the viral contamination in this hydrographic boundary region used by the local populations for recreation and consumption, establishing an elevated risk of gastroenteric diseases for human health.

  11. Deciphering the Diversities of Astroviruses and Noroviruses in Wastewater Treatment Plant Effluents by a High-Throughput Sequencing Method.

    PubMed

    Prevost, B; Lucas, F S; Ambert-Balay, K; Pothier, P; Moulin, L; Wurtzer, S

    2015-10-01

    Although clinical epidemiology lists human enteric viruses to be among the primary causes of acute gastroenteritis in the human population, their circulation in the environment remains poorly investigated. These viruses are excreted by the human population into sewers and may be released into rivers through the effluents of wastewater treatment plants (WWTPs). In order to evaluate the viral diversity and loads in WWTP effluents of the Paris, France, urban area, which includes about 9 million inhabitants (approximately 15% of the French population), the seasonal occurrence of astroviruses and noroviruses in 100 WWTP effluent samples was investigated over 1 year. The coupling of these measurements with a high-throughput sequencing approach allowed the specific estimation of the diversity of human astroviruses (human astrovirus genotype 1 [HAstV-1], HAstV-2, HAstV-5, and HAstV-6), 7 genotypes of noroviruses (NoVs) of genogroup I (NoV GI.1 to NoV GI.6 and NoV GI.8), and 16 genotypes of NoVs of genogroup II (NoV GII.1 to NoV GII.7, NoV GII.9, NoV GII.12 to NoV GII.17, NoV GII.20, and NoV GII.21) in effluent samples. Comparison of the viral diversity in WWTP effluents to the viral diversity found by analysis of clinical data obtained throughout France underlined the consistency between the identified genotypes. However, some genotypes were locally present in effluents and were not found in the analysis of the clinical data. These findings could highlight an underestimation of the diversity of enteric viruses circulating in the human population. Consequently, analysis of WWTP effluents could allow the exploration of viral diversity not only in environmental waters but also in a human population linked to a sewerage network in order to better comprehend viral epidemiology and to forecast seasonal outbreaks. PMID:26253673

  12. Enhanced Research to Create More Jobs

    SciTech Connect

    Agnihotri, Newal, K.

    2004-03-01

    Mr. Doc Hastings, U.S. Congressman from the state of Washington is interviewed regarding various topics related to the nuclear energy picture in the US. Topics include the level of public support for nuclear energy, differences between the roles for state and federal governments, job creation, clean-up briefings, a Yucca Mountain status, a hydrogen-nuclear status, the role of nuclear energy in Kyoto protocol compliance, and the market for power plants.

  13. Prevalence of Astrovirus Infection among Chilean Children with Acute Gastroenteritis

    PubMed Central

    Gaggero, Aldo; O’Ryan, Miguel; Noel, Jacqueline S.; Glass, Roger I.; Monroe, Stephan S.; Mamani, Nora; Prado, Valeria; Avendaño, Luis F.

    1998-01-01

    The frequency of astrovirus infection in 456 Chilean children with diarrhea was determined by enzyme-linked immunosorbent assay, reverse transcriptase PCR, and cell culture. Astrovirus was detected in 16.5% of rotavirus-negative and 7% of rotavirus-positive samples obtained from emergency rooms or hospitals and in 11% of samples from day care centers. HAst-1 was the predominant serotype identified. PMID:9817899

  14. de Finetti Priors using Markov chain Monte Carlo computations

    PubMed Central

    Bacallado, Sergio; Diaconis, Persi; Holmes, Susan

    2015-01-01

    Recent advances in Monte Carlo methods allow us to revisit work by de Finetti who suggested the use of approximate exchangeability in the analyses of contingency tables. This paper gives examples of computational implementations using Metropolis Hastings, Langevin and Hamiltonian Monte Carlo to compute posterior distributions for test statistics relevant for testing independence, reversible or three way models for discrete exponential families using polynomial priors and Gröbner bases. PMID:26412947

  15. Comparison of the kinetics of different Markov models for ligand binding under varying conditions

    SciTech Connect

    Martini, Johannes W. R.; Habeck, Michael

    2015-03-07

    We recently derived a Markov model for macromolecular ligand binding dynamics from few physical assumptions and showed that its stationary distribution is the grand canonical ensemble [J. W. R. Martini, M. Habeck, and M. Schlather, J. Math. Chem. 52, 665 (2014)]. The transition probabilities of the proposed Markov process define a particular Glauber dynamics and have some similarity to the Metropolis-Hastings algorithm. Here, we illustrate that this model is the stochastic analog of (pseudo) rate equations and the corresponding system of differential equations. Moreover, it can be viewed as a limiting case of general stochastic simulations of chemical kinetics. Thus, the model links stochastic and deterministic approaches as well as kinetics and equilibrium described by the grand canonical ensemble. We demonstrate that the family of transition matrices of our model, parameterized by temperature and ligand activity, generates ligand binding kinetics that respond to changes in these parameters in a qualitatively similar way as experimentally observed kinetics. In contrast, neither the Metropolis-Hastings algorithm nor the Glauber heat bath reflects changes in the external conditions correctly. Both converge rapidly to the stationary distribution, which is advantageous when the major interest is in the equilibrium state, but fail to describe the kinetics of ligand binding realistically. To simulate cellular processes that involve the reversible stochastic binding of multiple factors, our pseudo rate equation model should therefore be preferred to the Metropolis-Hastings algorithm and the Glauber heat bath, if the stationary distribution is not of only interest.

  16. Stability of large systems

    NASA Astrophysics Data System (ADS)

    Hastings, Harold

    2007-03-01

    We address a long-standing dilemma concerning stability of large systems. MacArthur (1955) and Hutchinson (1959) argued that more ``complex'' natural systems tended to be more stable than less complex systems based upon energy flow. May (1972) argued the opposite, using random matrix models; see Cohen and Newman (1984, 1985), Bai and Yin (1986). We show that in some sense both are right: under reasonable scaling assumptions on interaction strength, Lyapunov stability increases but structural stability decreases as complexity is increased (c.f. Harrison, 1979; Hastings, 1984). We apply this result to a variety of network systems. References: Bai, Z.D. & Yin, Y.Q. 1986. Probab. Th. Rel. Fields 73, 555. Cohen, J.E., & Newman, C.M. 1984. Annals Probab. 12, 283; 1985. Theoret. Biol. 113, 153. Harrison, G.W. 1979. Amer. Natur. 113, 659. Hastings, H.M. 1984. BioSystems 17, 171. Hastings, H.M., Juhasz, F., & Schreiber, M. 1992. .Proc. Royal Soc., Ser. B. 249, 223. Hutchinson, G.E. 1959. Amer. Natur. 93, 145, MacArthur, R. H. 1955. Ecology 35, 533, May, R.M. 1972. Nature 238, 413.

  17. Resistant starch reduces colonic and urinary p-cresol in rats fed a tyrosine-supplemented diet, whereas konjac mannan does not.

    PubMed

    Chen, Bixiao; Morioka, Sahya; Nakagawa, Tomoyuki; Hayakawa, Takashi

    2016-10-01

    The effect of resistant starch (RS) and konjac mannan (KM) to maintain and improve the large intestinal environment was compared. Wistar SPF rats were fed the following diets for 4 weeks: negative control diet (C diet), tyrosine-supplemented positive control diet (T diet), and luminacoid supplemented diets containing either high-molecular konjac mannan A (KMAT diet), low-molecular konjac mannan B (KMBT diet), high-amylose cornstarch (HAST diet), or heat-moisture-treated starch (HMTST diet). The luminacoid-fed group had an increased content of short-chain fatty acids in the cecum. HAS caused a significant decrease in p-cresol content in the cecum, whereas KM did not. Urinary p-cresol was reduced in the HAST group compared with the T group, but not the KM fed groups. Deterioration in the large intestinal environment was only improved completely in the HAST and HMTST groups, suggesting that RS is considerably more effective than KM in maintaining the large intestinal environment.

  18. The detectability lemma and its applications to quantum Hamiltonian complexity

    NASA Astrophysics Data System (ADS)

    Aharonov, Dorit; Arad, Itai; Vazirani, Umesh; Landau, Zeph

    2011-11-01

    Quantum Hamiltonian complexity, an emerging area at the intersection of condensed matter physics and quantum complexity theory, studies the properties of local Hamiltonians and their ground states. In this paper we focus on a seemingly specialized technical tool, the detectability lemma (DL), introduced in the context of the quantum PCP challenge (Aharonov et al 2009 arXiv:0811.3412), which is a major open question in quantum Hamiltonian complexity. We show that a reformulated version of the lemma is a versatile tool that can be used in place of the celebrated Lieb-Robinson (LR) bound to prove several important results in quantum Hamiltonian complexity. The resulting proofs are much simpler, more combinatorial and provide a plausible path toward tackling some fundamental open questions in Hamiltonian complexity. We provide an alternative simpler proof of the DL that removes a key restriction in the original statement (Aharonov et al 2009 arXiv:0811.3412), making it more suitable for the broader context of quantum Hamiltonian complexity. Specifically, we first use the DL to provide a one-page proof of Hastings' result that the correlations in the ground states of gapped Hamiltonians decay exponentially with distance (Hastings 2004 Phys. Rev. B 69 104431). We then apply the DL to derive a simpler and more intuitive proof of Hastings' seminal one-dimensional (1D) area law (Hastings 2007 J. Stat. Mech. (2007) P8024) (both these proofs are restricted to frustration-free systems). Proving the area law for two and higher dimensions is one of the most important open questions in the field of Hamiltonian complexity, and the combinatorial nature of the DL-based proof holds out hope for a possible generalization. Indeed, soon after the first publication of the methods presented here, they were applied to derive exponential improvements to Hastings' result (Arad et al 2011, Aharonov et al 2011) in the case of frustration-free 1D systems. Finally, we also provide a more general

  19. The Anatomy and Phylogenetic Relationships of "Pelorosaurus" becklesii (Neosauropoda, Macronaria) from the Early Cretaceous of England.

    PubMed

    Upchurch, Paul; Mannion, Philip D; Taylor, Michael P

    2015-01-01

    The sauropod dinosaur "Pelorosaurus" becklesii was named in 1852 on the basis of an associated left humerus, ulna, radius and skin impression from the Early Cretaceous (Berriasian-Valanginian) Hastings Beds Group, near Hastings, East Sussex, southeast England, United Kingdom. The taxonomy and nomenclature of this specimen have a complex history, but most recent workers have agreed that "P." becklesii represents a distinct somphospondylan (or at least a titanosauriform) and is potentially the earliest titanosaur body fossil from Europe or even globally. The Hastings specimen is distinct from the approximately contemporaneous Pelorosaurus conybeari from Tilgate Forest, West Sussex. "P." becklesii can be diagnosed on the basis of five autapomorphies, such as: a prominent anteriorly directed process projecting from the anteromedial corner of the distal humerus; the proximal end of the radius is widest anteroposteriorly along its lateral margin; and the unique combination of a robust ulna and slender radius. The new generic name Haestasaurus is therefore erected for "P." becklesii. Three revised and six new fore limb characters (e.g. the presence/absence of condyle-like projections on the posterodistal margin of the radius) are discussed and added to three cladistic data sets for Sauropoda. Phylogenetic analysis confirms that Haestasaurus becklesii is a macronarian, but different data sets place this species either as a non-titanosauriform macronarian, or within a derived clade of titanosaurs that includes Malawisaurus and Saltasauridae. This uncertainty is probably caused by several factors, including the incompleteness of the Haestasaurus holotype and rampant homoplasy in fore limb characters. Haestasaurus most probably represents a basal macronarian that independently acquired the robust ulna, enlarged olecranon, and other states that have previously been regarded as synapomorphies of clades within Titanosauria. There is growing evidence that basal macronarian taxa

  20. The Anatomy and Phylogenetic Relationships of “Pelorosaurus“ becklesii (Neosauropoda, Macronaria) from the Early Cretaceous of England

    PubMed Central

    Upchurch, Paul; Mannion, Philip D.; Taylor, Michael P.

    2015-01-01

    The sauropod dinosaur “Pelorosaurus” becklesii was named in 1852 on the basis of an associated left humerus, ulna, radius and skin impression from the Early Cretaceous (Berriasian-Valanginian) Hastings Beds Group, near Hastings, East Sussex, southeast England, United Kingdom. The taxonomy and nomenclature of this specimen have a complex history, but most recent workers have agreed that “P.” becklesii represents a distinct somphospondylan (or at least a titanosauriform) and is potentially the earliest titanosaur body fossil from Europe or even globally. The Hastings specimen is distinct from the approximately contemporaneous Pelorosaurus conybeari from Tilgate Forest, West Sussex. “P.” becklesii can be diagnosed on the basis of five autapomorphies, such as: a prominent anteriorly directed process projecting from the anteromedial corner of the distal humerus; the proximal end of the radius is widest anteroposteriorly along its lateral margin; and the unique combination of a robust ulna and slender radius. The new generic name Haestasaurus is therefore erected for “P.” becklesii. Three revised and six new fore limb characters (e.g. the presence/absence of condyle-like projections on the posterodistal margin of the radius) are discussed and added to three cladistic data sets for Sauropoda. Phylogenetic analysis confirms that Haestasaurus becklesii is a macronarian, but different data sets place this species either as a non-titanosauriform macronarian, or within a derived clade of titanosaurs that includes Malawisaurus and Saltasauridae. This uncertainty is probably caused by several factors, including the incompleteness of the Haestasaurus holotype and rampant homoplasy in fore limb characters. Haestasaurus most probably represents a basal macronarian that independently acquired the robust ulna, enlarged olecranon, and other states that have previously been regarded as synapomorphies of clades within Titanosauria. There is growing evidence that basal

  1. Implementation and evaluation of a new workflow for registration and segmentation of pulmonary MRI data for regional lung perfusion assessment

    NASA Astrophysics Data System (ADS)

    Böttger, T.; Grunewald, K.; Schöbinger, M.; Fink, C.; Risse, F.; Kauczor, H. U.; Meinzer, H. P.; Wolf, Ivo

    2007-03-01

    Recently it has been shown that regional lung perfusion can be assessed using time-resolved contrast-enhanced magnetic resonance (MR) imaging. Quantification of the perfusion images has been attempted, based on definition of small regions of interest (ROIs). Use of complete lung segmentations instead of ROIs could possibly increase quantification accuracy. Due to the low signal-to-noise ratio, automatic segmentation algorithms cannot be applied. On the other hand, manual segmentation of the lung tissue is very time consuming and can become inaccurate, as the borders of the lung to adjacent tissues are not always clearly visible. We propose a new workflow for semi-automatic segmentation of the lung from additionally acquired morphological HASTE MR images. First the lung is delineated semi-automatically in the HASTE image. Next the HASTE image is automatically registered with the perfusion images. Finally, the transformation resulting from the registration is used to align the lung segmentation from the morphological dataset with the perfusion images. We evaluated rigid, affine and locally elastic transformations, suitable optimizers and different implementations of mutual information (MI) metrics to determine the best possible registration algorithm. We located the shortcomings of the registration procedure and under which conditions automatic registration will succeed or fail. Segmentation results were evaluated using overlap and distance measures. Integration of the new workflow reduces the time needed for post-processing of the data, simplifies the perfusion quantification and reduces interobserver variability in the segmentation process. In addition, the matched morphological data set can be used to identify morphologic changes as the source for the perfusion abnormalities.

  2. Norovirus Diversity in Diarrheic Children from an African-Descendant Settlement in Belém, Northern Brazil

    PubMed Central

    Aragão, Glicélia Cruz; Mascarenhas, Joana D'Arc Pereira; Kaiano, Jane Haruko Lima; de Lucena, Maria Silvia Sousa; Siqueira, Jones Anderson Monteiro; Fumian, Túlio Machado; Hernandez, Juliana das Mercês; de Oliveira, Consuelo Silva; Oliveira, Darleise de Souza; Araújo, Eliete da Cunha; Soares, Luana da Silva; Linhares, Alexandre Costa; Gabbay, Yvone Benchimol

    2013-01-01

    Norovirus (NoV), sapovirus (SaV) and human astrovirus (HAstV) are viral pathogens that are associated with outbreaks and sporadic cases of gastroenteritis. However, little is known about the occurrence of these pathogens in relatively isolated communities, such as the remnants of African-descendant villages (“Quilombola”). The objective of this study was the frequency determination of these viruses in children under 10 years, with and without gastroenteritis, from a “Quilombola” Community, Northern Brazil. A total of 159 stool samples were obtained from April/2008 to July/2010 and tested by an enzyme immunoassay (EIA) and reverse transcription-polymerase chain reaction (RT-PCR) to detect NoV, SaV and HAstV, and further molecular characterization was performed. These viruses were detected only in the diarrheic group. NoV was the most frequent viral agent detected (19.7%-16/81), followed by SaV (2.5%-2/81) and HAstV (1.2%-1/81). Of the 16 NoV-positive samples, 14 were sequenced with primers targeting the B region of the polymerase (ORF1) and the D region of the capsid (ORF2). The results showed a broad genetic diversity of NoV, with 12 strains being classified as GII-4 (5–41.7%), GII-6 (3–25%), GII-7 (2–16.7%), GII-17 (1–8.3%) and GI-2 (1–8.3%), as based on the polymerase region; 12 samples were classified, based on the capsid region, as GII-4 (6–50%, being 3–2006b variant and 3–2010 variant), GII-6 (3–25%), GII-17 (2–16.7%) and GII-20 (1–8.3%). One NoV-strain showed dual genotype specificity, based on the polymerase and capsid region (GII-7/GII-20). This study provides, for the first time, epidemiological and molecular information on the circulation of NoV, SaV and HAstV in African-descendant communities in Northern Brazil and identifies NoV genotypes that were different from those detected previously in studies conducted in the urban area of Belém. It remains to be determined why a broader NoV diversity was observed in such a semi

  3. Rapid recipe formulation for plasma etching of new materials

    NASA Astrophysics Data System (ADS)

    Chopra, Meghali; Zhang, Zizhuo; Ekerdt, John; Bonnecaze, Roger T.

    2016-03-01

    A fast and inexpensive scheme for etch rate prediction using flexible continuum models and Bayesian statistics is demonstrated. Bulk etch rates of MgO are predicted using a steady-state model with volume-averaged plasma parameters and classical Langmuir surface kinetics. Plasma particle and surface kinetics are modeled within a global plasma framework using single component Metropolis Hastings methods and limited data. The accuracy of these predictions is evaluated with synthetic and experimental etch rate data for magnesium oxide in an ICP-RIE system. This approach is compared and superior to factorial models generated from JMP, a software package frequently employed for recipe creation and optimization.

  4. Eigenvalue analysis of an irreversible random walk with skew detailed balance conditions.

    PubMed

    Sakai, Yuji; Hukushima, Koji

    2016-04-01

    An irreversible Markov-chain Monte Carlo (MCMC) algorithm with skew detailed balance conditions originally proposed by Turitsyn et al. is extended to general discrete systems on the basis of the Metropolis-Hastings scheme. To evaluate the efficiency of our proposed method, the relaxation dynamics of the slowest mode and the asymptotic variance are studied analytically in a random walk on one dimension. It is found that the performance in irreversible MCMC methods violating the detailed balance condition is improved by appropriately choosing parameters in the algorithm. PMID:27176439

  5. Genetics and bioethics: how our thinking has changed since 1969.

    PubMed

    Walters, LeRoy

    2012-02-01

    In 1969, the field of human genetics was in its infancy. Amniocentesis was a new technique for prenatal diagnosis, and a newborn genetic screening program had been established in one state. There were also concerns about the potential hazards of genetic engineering. A research group at the Hastings Center and Paul Ramsey pioneered in the discussion of genetics and bioethics. Two principal techniques have emerged as being of enduring importance: human gene transfer research and genetic testing and screening. This essay tracks the development and use of these techniques and considers the ethical issues that they raise.

  6. Outage managment and health physics issue, 2008

    SciTech Connect

    Agnihotri, Newal

    2008-05-15

    The focus of the May-June issue is on outage management and health physics. Major articles include: Outage optimization initiatives, by George B. Beam, AREVA NP, Inc.; New plant based on excellent track records, by Jim Scarola, Progress Energy; Meeting customer needs and providing environmental benefits, by Peter S. Hastings, Duke Energy; Plants with 3-D design, by Jack A. Bailey, Tennessee Valley Authority; and Highest quality with exceptional planning, by Jason A. Walls, Duke Energy. Industry innovation articles include: Integrated exposure reduction plan, by Ed Wolfe, Exelon; Performance-based radiation worker training, by Joe Giuffre and Timothy Vriezerma, American Electric Power.

  7. Asymptotics of a Fredholm Determinant Corresponding to the First Bulk Critical Universality Class in Random Matrix Models

    NASA Astrophysics Data System (ADS)

    Bothner, Thomas; Its, Alexander

    2014-05-01

    We study the determinant det( I- K PII) of an integrable Fredholm operator K PII acting on the interval (- s, s) whose kernel is constructed out of the Ψ-function associated with the Hastings-McLeod solution of the second Painlevé equation. This Fredholm determinant describes the critical behavior of the eigenvalue gap probabilities of a random Hermitian matrix chosen from the unitary ensemble in the bulk double scaling limit near a quadratic zero of the limiting mean eigenvalue density. Using the Riemann-Hilbert method, we evaluate the large s-asymptotics of det( I- K PII).

  8. Double scaling limit for matrix models with nonanalytic potentials

    NASA Astrophysics Data System (ADS)

    Shcherbina, Mariya

    2008-03-01

    We study the double scaling limit for unitary invariant ensembles of random matrices with nonanalytic potentials and find the asymptotic expansion for the entries of the corresponding Jacobi matrix. Our approach is based on the perturbation expansion for the string equations. The first order perturbation terms of the Jacobi matrix coefficients are expressed through the Hastings-McLeod solution of the Painleve II equation. The limiting reproducing kernel is expressed in terms of solutions of the Dirac system of differential equations with a potential defined by the first order terms of the expansion.

  9. Padé approximations for Painlevé I and II transcendents

    NASA Astrophysics Data System (ADS)

    Novokshenov, V. Yu.

    2009-06-01

    We use a version of the Fair-Luke algorithm to find the Padé approximate solutions of the Painlevé I and II equations. We find the distributions of poles for the well-known Ablowitz-Segur and Hastings-McLeod solutions of the Painlevé II equation. We show that the Boutroux tritronquée solution of the Painleé I equation has poles only in the critical sector of the complex plane. The algorithm allows checking other analytic properties of the Painlevé transcendents, such as the asymptotic behavior at infinity in the complex plane.

  10. Eutrophication control and the fallacy of nitrogen removal

    SciTech Connect

    Sincero, A.P.

    1984-11-01

    There has been a great deal of controversy over the issue of nitrogen control from sewage treatment plants discharges to alleviate excessive algae growths in receiving bodies of water. Some of the controversy seems to have risen from a thorough misunderstanding of the microbiology involved in the utilization of nitrogen by microbes. In a haste to control eutrophication, some regulators have required the removal of nitrogen from the effluent of sewage treatment plants; e.g., the Patuxent Nitrogen Removal Policy of the State of Maryland.

  11. [Discharge of very preterm infants from neonatology: check list].

    PubMed

    Arnaud, F

    2004-02-01

    Key elements of the check list for neonatal discharge include: discharge discussion with parents, relation with maternal and child welfare assistants and family practitioner, scheduling of follow-up visits, request for insurance coverage, parental presence allowance, special education allowance, debriefing with nurses and nurses providers, clinical and biological appraisal, discharge prescription. For a former extremely premature baby, going home - often after a long hospitalization and a variety of pathologic problems - must be prepared and should not be decided in haste, not only for the baby and his/her parents, but also. for the neonatal staff! PMID:14968030

  12. Ethics committees as corporate and public policy advocates.

    PubMed

    Cohen, C B

    1990-01-01

    The "Ethics committees" column in this issue of the Hastings Center Report features an introduction by Cynthia B. Cohen and four brief commentaries on the roles hospital ethics committees may play in the making of institutional and public health care policy in the 1990s. The pros and cons of a broader, more public role for ethics committees in reconciling the business and patient care aspects of health care delivery are debated by Cohen in this commentary, and by Philip Boyle in "Business ethics in ethics committees?"

  13. Fitting complex population models by combining particle filters with Markov chain Monte Carlo.

    PubMed

    Knape, Jonas; de Valpine, Perry

    2012-02-01

    We show how a recent framework combining Markov chain Monte Carlo (MCMC) with particle filters (PFMCMC) may be used to estimate population state-space models. With the purpose of utilizing the strengths of each method, PFMCMC explores hidden states by particle filters, while process and observation parameters are estimated using an MCMC algorithm. PFMCMC is exemplified by analyzing time series data on a red kangaroo (Macropus rufus) population in New South Wales, Australia, using MCMC over model parameters based on an adaptive Metropolis-Hastings algorithm. We fit three population models to these data; a density-dependent logistic diffusion model with environmental variance, an unregulated stochastic exponential growth model, and a random-walk model. Bayes factors and posterior model probabilities show that there is little support for density dependence and that the random-walk model is the most parsimonious model. The particle filter Metropolis-Hastings algorithm is a brute-force method that may be used to fit a range of complex population models. Implementation is straightforward and less involved than standard MCMC for many models, and marginal densities for model selection can be obtained with little additional effort. The cost is mainly computational, resulting in long running times that may be improved by parallelizing the algorithm.

  14. AN AFFINE-INVARIANT SAMPLER FOR EXOPLANET FITTING AND DISCOVERY IN RADIAL VELOCITY DATA

    SciTech Connect

    Hou Fengji; Hogg, David W.; Goodman, Jonathan; Weare, Jonathan; Schwab, Christian

    2012-02-01

    Markov chain Monte Carlo (MCMC) proves to be powerful for Bayesian inference and in particular for exoplanet radial velocity fitting because MCMC provides more statistical information and makes better use of data than common approaches like chi-square fitting. However, the nonlinear density functions encountered in these problems can make MCMC time-consuming. In this paper, we apply an ensemble sampler respecting affine invariance to orbital parameter extraction from radial velocity data. This new sampler has only one free parameter, and does not require much tuning for good performance, which is important for automatization. The autocorrelation time of this sampler is approximately the same for all parameters and far smaller than Metropolis-Hastings, which means it requires many fewer function calls to produce the same number of independent samples. The affine-invariant sampler speeds up MCMC by hundreds of times compared with Metropolis-Hastings in the same computing situation. This novel sampler would be ideal for projects involving large data sets such as statistical investigations of planet distribution. The biggest obstacle to ensemble samplers is the existence of multiple local optima; we present a clustering technique to deal with local optima by clustering based on the likelihood of the walkers in the ensemble. We demonstrate the effectiveness of the sampler on real radial velocity data.

  15. Effect of High Temperature Storage in Vacuum, Air, and Humid Conditions on Degradation of Gold/Aluminum Wire Bonds in PEMs

    NASA Technical Reports Server (NTRS)

    Teverovsky, Alexander

    2006-01-01

    Microcircuits encapsulated in three plastic package styles were stored in different environments at temperatures varying from 130 C to 225 C for up to 4,000 hours in some cases. To assess the effect of oxygen, the parts were aged at high temperatures in air and in vacuum chambers. The effect of humidity was evaluated during long-term highly accelerated temperature and humidity stress testing (HAST) at temperatures of 130 C and 150 C. High temperature storage testing of decapsulated microcircuits in air, vacuum, and HAST chambers was carried out to evaluate the role of molding compounds in the environmentally-induced degradation and failure of wire bonds (WB). This paper reports on accelerating factors of environment and molding compound on WB failures. It has been shown that all environments, including oxygen, moisture, and the presence of molding compounds reduce time-to-failures compared to unencapsulated devices in vacuum conditions. The mechanism of the environmental effect on KB degradation is discussed.

  16. Fitting complex population models by combining particle filters with Markov chain Monte Carlo.

    PubMed

    Knape, Jonas; de Valpine, Perry

    2012-02-01

    We show how a recent framework combining Markov chain Monte Carlo (MCMC) with particle filters (PFMCMC) may be used to estimate population state-space models. With the purpose of utilizing the strengths of each method, PFMCMC explores hidden states by particle filters, while process and observation parameters are estimated using an MCMC algorithm. PFMCMC is exemplified by analyzing time series data on a red kangaroo (Macropus rufus) population in New South Wales, Australia, using MCMC over model parameters based on an adaptive Metropolis-Hastings algorithm. We fit three population models to these data; a density-dependent logistic diffusion model with environmental variance, an unregulated stochastic exponential growth model, and a random-walk model. Bayes factors and posterior model probabilities show that there is little support for density dependence and that the random-walk model is the most parsimonious model. The particle filter Metropolis-Hastings algorithm is a brute-force method that may be used to fit a range of complex population models. Implementation is straightforward and less involved than standard MCMC for many models, and marginal densities for model selection can be obtained with little additional effort. The cost is mainly computational, resulting in long running times that may be improved by parallelizing the algorithm. PMID:22624307

  17. An Affine-invariant Sampler for Exoplanet Fitting and Discovery in Radial Velocity Data

    NASA Astrophysics Data System (ADS)

    Hou, Fengji; Goodman, Jonathan; Hogg, David W.; Weare, Jonathan; Schwab, Christian

    2012-02-01

    Markov chain Monte Carlo (MCMC) proves to be powerful for Bayesian inference and in particular for exoplanet radial velocity fitting because MCMC provides more statistical information and makes better use of data than common approaches like chi-square fitting. However, the nonlinear density functions encountered in these problems can make MCMC time-consuming. In this paper, we apply an ensemble sampler respecting affine invariance to orbital parameter extraction from radial velocity data. This new sampler has only one free parameter, and does not require much tuning for good performance, which is important for automatization. The autocorrelation time of this sampler is approximately the same for all parameters and far smaller than Metropolis-Hastings, which means it requires many fewer function calls to produce the same number of independent samples. The affine-invariant sampler speeds up MCMC by hundreds of times compared with Metropolis-Hastings in the same computing situation. This novel sampler would be ideal for projects involving large data sets such as statistical investigations of planet distribution. The biggest obstacle to ensemble samplers is the existence of multiple local optima; we present a clustering technique to deal with local optima by clustering based on the likelihood of the walkers in the ensemble. We demonstrate the effectiveness of the sampler on real radial velocity data.

  18. Molecular cloning, expression and first antigenic characterization of human astrovirus VP26 structural protein and a C-terminal deleted form.

    PubMed

    Royuela, Enrique; Sánchez-Fauquier, Alicia

    2010-01-01

    The open reading frame 2 (ORF2) of human astrovirus (HAstV) encodes the structural VP26 protein that seems to be the main antigenic viral protein. However, its functional role remains unclear. Bioinformatic predictions revealed that VP29 and VP26 proteins could be involved in virus-cell interaction. In this study, we describe for the first time the cloning and expression in Escherichia coli (E. coli) of a recombinant VP26 (rVP26) protein and a VP26 C-terminal truncated form (VP26 Delta C), followed by purification by NTA-Ni(2+) agarose affinity chromatography. Protein expression and purification were evaluated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot (WB). Then, the purified proteins were evaluated for antigenic properties in enzyme linked immunosorbent assay (ELISA) using a polyclonal antibody (PAb) and a neutralizing monoclonal antibody (nMAb) named PL2, both of them directed to HAstV. The results presented herein indicate that the C-terminal end of the VP26 protein is essential to maintain the neutralizing epitope recognized by nMAb PL2 and that the N-terminus of VP26 protein may contain antigenic lineal-epitopes recognized by PAb. Thus, these recombinant proteins can be ideal tools for further antigenic, biochemical, structural and functional VP26 protein characterization, in order to evaluate its potential role in immunodiagnosis and vaccine studies.

  19. Local-TQO and Stability of Frustration-Free Hamiltonians

    NASA Astrophysics Data System (ADS)

    Pytel, Justyna; Michalakis, Spyridon

    2012-02-01

    The attention of the condensed matter and mathematical physics communities has recently focused on Hamiltonians with low-energy sectors exhibiting some form of topological order. In our work [1], we present a generalization of the result of Bravyi et al. [2,3] on the stability of topological quantum order for Hamiltonians composed of commuting projections with a common zero-energy subspace. In particular, the commutativity condition can be removed: We prove stability of the spectral gap for gapped, frustration-free Hamiltonians under general, quasi-local perturbations. Also, we will discuss the ``Local Topological Quantum Order'' and ``Local-Gap'' conditions sufficient for proving stability. [4pt] [1] S. Michalakis and J. Pytel, Stability of Frustration-Free Hamiltonians. arXiv:1109.1588 (2011).[0pt] [2] S. Bravyi and M.B. Hastings, A short proof of stability of topological order under local perturbations. arXiv:1001.4363. [0pt] [3] S. Bravyi, M.B. Hastings, and S. Michalakis, Topological quantum order: stability under local perturbations. J. Math. Phys. 51, 093512 (2010).

  20. Inscribed matter as an energy-efficient means of communication with an extraterrestrial civilization.

    PubMed

    Rose, Christopher; Wright, Gregory

    2004-09-01

    It is well known that electromagnetic radiation-radio waves-can in principle be used to communicate over interstellar distances. By contrast, sending physical artefacts has seemed extravagantly wasteful of energy, and imagining human travel between the stars even more so. The key consideration in earlier work, however, was the perceived need for haste. If extraterrestrial civilizations existed within a few tens of light years, radio could be used for two-way communication on timescales comparable to human lifetimes (or at least the longevities of human institutions). Here we show that if haste is unimportant, sending messages inscribed on some material can be strikingly more energy efficient than communicating by electromagnetic waves. Because messages require protection from cosmic radiation and small messages could be difficult to find among the material clutter near a recipient, 'inscribed matter' is most effective for long archival messages (as opposed to potentially short "we exist" announcements). The results suggest that our initial contact with extraterrestrial civilizations may be more likely to occur through physical artefacts-essentially messages in a bottle-than via electromagnetic communication.

  1. Roughness Scaling for the Edwards-Wilkinson Model on Small-World Substrates

    NASA Astrophysics Data System (ADS)

    Kozma, B.; Hastings, M. B.; Korniss, G.

    2004-03-01

    We studied the generalization of the Edwards-Wilkinson model to substrates with small-world topology(B. Kozma, M.B. Hastings, and G. Korniss, cond-mat/0309196 (2003).). We considered two implementations of this topology, the ``hard'' version of the network, where each site has exactly one random link of strength p, and the ``soft'' one, where each site on average has p random links of unit strength. Both versions are embedded in one dimension. The research is motivated in part by a recent general criterion for mean-field behavior(M.B. Hastings, Physical Review Letters 91), 098701 (2003). predicting the model to exhibit anomalous scaling on the soft network, and also by synchronization problems in scalable parallel computing(G. Korniss et al., Science 299), 677 (2003). We used impurity averaged perturbation technique to calculate the width in both the weak- and sparse-coupling limits, for the hard and soft network, respectively. The width remains finite in both cases in the infinite system-size limit, but scales differently as p tends to zero. We verified our analytic results by comparing them to those of exact numerical diagonalization.

  2. Markov chain Monte Carlo methods: an introductory example

    NASA Astrophysics Data System (ADS)

    Klauenberg, Katy; Elster, Clemens

    2016-02-01

    When the Guide to the Expression of Uncertainty in Measurement (GUM) and methods from its supplements are not applicable, the Bayesian approach may be a valid and welcome alternative. Evaluating the posterior distribution, estimates or uncertainties involved in Bayesian inferences often requires numerical methods to avoid high-dimensional integrations. Markov chain Monte Carlo (MCMC) sampling is such a method—powerful, flexible and widely applied. Here, a concise introduction is given, illustrated by a simple, typical example from metrology. The Metropolis-Hastings algorithm is the most basic and yet flexible MCMC method. Its underlying concepts are explained and the algorithm is given step by step. The few lines of software code required for its implementation invite interested readers to get started. Diagnostics to evaluate the performance and common algorithmic choices are illustrated to calibrate the Metropolis-Hastings algorithm for efficiency. Routine application of MCMC algorithms may be hindered currently by the difficulty to assess the convergence of MCMC output and thus to assure the validity of results. An example points to the importance of convergence and initiates discussion about advantages as well as areas of research. Available software tools are mentioned throughout.

  3. Improved resolution and a novel phylogeny for the Neotropical triplefin blennies (Teleostei: Tripterygiidae).

    PubMed

    Miller, Elizabeth Christina; Lin, Hsiu-Chin; Hastings, Philip A

    2016-03-01

    The triplefin blennies (Teleostei: Tripterygiidae) are a diverse group of small-bodied benthic fishes associated with rocky or coral reefs. The Neotropics contain four genera and 26 species, many of which have only been recently described. A recent molecular phylogeny (Lin and Hastings, 2013) contrasts with previous phylogenies based on morphology in recovering the four Neotropical genera as a single clade with respect to the Indo-Pacific genera; however, relationships within and among genera were poorly resolved. This study reports a novel topology based on an expanded seven-loci molecular dataset. Individual gene trees have poor resolution, but concatenated analyses show strong support for most nodes, likely due to emergent support from concatenation. Consistent with Lin and Hastings (2013), three of the Neotropical genera, Axoclinus, Enneanectes, and Crocodilichthys, form a well-supported clade, but relationships of the fourth (Lepidonectes) are not confidently resolved. The monophyly of Axoclinus is well supported, but Enneanectes is paraphyletic with the inclusion of Axoclinus and Crocodilichthys. Improved resolution allows for reinterpretation of the biogeography of the Neotropical Tripterygiidae. Broader taxon sampling is still necessary for resolving the relationships within Tripterygiidae globally. PMID:26718057

  4. Resolution enhanced T1-insensitive steady-state imaging.

    PubMed

    Derakhshan, Jamal J; Nour, Sherif G; Sunshine, Jeffrey L; Griswold, Mark A; Duerk, Jeffrey L

    2012-08-01

    Resolution enhanced T(1)-insensitive steady-state imaging (RE-TOSSI) is a new MRI pulse sequence for the generation of rapid T(2) contrast with high spatial resolution. TOSSI provides T(2) contrast by using nonequally spaced inversion pulses throughout a balanced steady-state free precession (SSFP) acquisition. In RE-TOSSI, these energy and time intensive adiabatic inversion pulses and associated magnetization preparation are removed from TOSSI after acquisition of the data around the center of k-space. Magnetization evolution simulations demonstrate T(2) contrast in TOSSI as well as reduction in the widening of the point spread function width (by up to a factor of 4) to a near ideal case for RE-TOSSI. Phantom experimentation is used to characterize and compare the contrast and spatial resolution properties of TOSSI, RE-TOSSI, balanced SSFP, Half-Fourier Acquisition Single-Shot Turbo Spin Echo (HASTE), and turbo spin echo and to optimize the fraction of k-space acquired using TOSSI. Comparison images in the abdomen and brain demonstrate similar contrast and improved spatial resolution in RE-TOSSI compared with TOSSI; comparison balanced SSFP, HASTE, and turbo spin echo images are provided. RE-TOSSI is capable of providing high spatial resolution T(2)-weighted images in 1 s or less per image.

  5. Frontoparietal white matter integrity predicts haptic performance in chronic stroke.

    PubMed

    Borstad, Alexandra L; Choi, Seongjin; Schmalbrock, Petra; Nichols-Larsen, Deborah S

    2016-01-01

    Frontoparietal white matter supports information transfer between brain areas involved in complex haptic tasks such as somatosensory discrimination. The purpose of this study was to gain an understanding of the relationship between microstructural integrity of frontoparietal network white matter and haptic performance in persons with chronic stroke and to compare frontoparietal network integrity in participants with stroke and age matched control participants. Nineteen individuals with stroke and 16 controls participated. Haptic performance was quantified using the Hand Active Sensation Test (HASTe), an 18-item match-to-sample test of weight and texture discrimination. Three tesla MRI was used to obtain diffusion-weighted and high-resolution anatomical images of the whole brain. Probabilistic tractography was used to define 10 frontoparietal tracts total; Four intrahemispheric tracts measured bilaterally 1) thalamus to primary somatosensory cortex (T-S1), 2) thalamus to primary motor cortex (T-M1), 3) primary to secondary somatosensory cortex (S1 to SII) and 4) primary somatosensory cortex to middle frontal gyrus (S1 to MFG) and, 2 interhemispheric tracts; S1-S1 and precuneus interhemispheric. A control tract outside the network, the cuneus interhemispheric tract, was also examined. The diffusion metrics fractional anisotropy (FA), mean diffusivity (MD), axial (AD) and radial diffusivity (RD) were quantified for each tract. Diminished FA and elevated MD values are associated with poorer white matter integrity in chronic stroke. Nine of 10 tracts quantified in the frontoparietal network had diminished structural integrity poststroke compared to the controls. The precuneus interhemispheric tract was not significantly different between groups. Principle component analysis across all frontoparietal white matter tract MD values indicated a single factor explained 47% and 57% of the variance in tract mean diffusivity in stroke and control groups respectively. Age

  6. Quantitative analysis of the breath-holding half-Fourier acquisition single-shot turbo spin-echo technique in abdominal MRI

    NASA Astrophysics Data System (ADS)

    Dong, Kyung-Rae; Goo, Eun-Hoe; Lee, Jae-Seung; Chung, Woon-Kwan

    2013-01-01

    A consecutive series of 50 patients (28 males and 22 females) who underwent hepatic magnetic resonance imaging (MRI) from August to December 2011 were enrolled in this study. The appropriate parameters for abdominal MRI scans were determined by comparing the images (TE = 90 and 128 msec) produced using the half-Fourier acquisition single-shot turbo spin-echo (HASTE) technique at different signal acquisition times. The patients consisted of 15 normal patients, 25 patients with a hepatoma and 10 patients with a hemangioma. The TE in a single patient was set to either 90 msec or 128 msec. This was followed by measurements using the four normal rendering methods of the biliary tract system and the background signal intensity using the maximal signal intensity techniques in the liver, spleen, pancreas, gallbladder, fat, muscles and hemangioma. The signal-to-noise and the contrast-to-noise ratios were obtained. The image quality was assessed subjectively, and the results were compared. The signal-to-noise and the contrast-to-noise ratios were significantly higher at TE = 128 msec than at TE = 90 when diseases of the liver, spleen, pancreas, gallbladder, and fat and muscles, hepatocellular carcinomas and hemangiomas, and rendering the hepatobiliary tract system based on the maximum signal intensity technique were involved (p < 0.05). In addition, the presence of artifacts, the image clarity and the overall image quality were excellent at TE = 128 msec (p < 0.05). In abdominal MRI, the breath-hold half-Fourier acquisition single-shot turbo spin-echo (HASTE) was found to be effective in illustrating the abdominal organs for TE = 128 msec. Overall, the image quality at TE = 128 msec was better than that at TE = 90 msec due to the improved signal-to-noise (SNR) and contrast-to-noise (CNR) ratios. Overall, the HASTE technique for abdominal MRI based on a high-magnetic field (3.0 T) at a TE of 128 msec can provide useful data.

  7. Mid-Eocene alluvial-lacustrine succession at Gebel El-Goza El-Hamra (Shabrawet area, NE Eastern Desert, Egypt): Facies analysis, sequence stratigraphy and paleoclimatic implications

    NASA Astrophysics Data System (ADS)

    Wanas, H. A.; Sallam, E.; Zobaa, M. K.; Li, X.

    2015-11-01

    This study aims to provide the depositional facies, sequence stratigraphic and paleoclimatic characteristics of the Mid-Eocene (Bartonian) continental succession exposed at Gebel El-Goza El-Hamra (Shabrawet Area, NE Eastern Desert, Egypt). The studied succession consists of siliciclastic rocks followed upward by carbonate rocks. Detailed field observation and petrographic investigation indicate accumulation in floodplain-dominated alluvial and shallow lacustrine systems. The floodplain-dominated alluvial facies (45 m thick) is composed mainly of carbonate nodules-bearing, mottled mudrock with subordinate sandstone and conglomerate beds. The conglomerate and pebbly sandstone bodies interpreted as ephemeral braided channel deposits. The massive, laminated, planner cross-bedded, fine- to medium-grained sandstone bodies interlayered within mudstone reflect sheet flood deposits. The mudrocks associated with paleosols represent distal floodplain deposits. The shallow lacustrine facies (15 m thick) is made up of an alternation of marlstone, micritic limestone, dolostone and mudrock beds with charophytes and small gastropods. Both the alluvial and lacustrine facies show evidence of macro-and micro-pedogenic features. Pollen assemblages, stable δ18O and δ13C isotopes, and paleopedogenic features reflect prevalence of arid to semi-arid climatic conditions during the Bartonian. The sequence stratigraphic framework shows an overall fining-upward depositional sequence, consisting of Low- and High-accommodation Systems Tracts (LAST, HAST), and is bounded by two sequence boundaries (SB-1, SB-2). Conglomerate and pebbly sandstone deposits (braided channel and sheet flood deposits) of the lower part of the alluvial facies reflect a LAST. Mudrock and silty claystone facies (distal floodplain deposits) of the upper part of alluvial facies and its overlying lacustrine facies correspond to a HAST. The LAST, HAST and SB were formed during different accommodation-to-sediment supply (A

  8. DNA Microarray for Detection of Gastrointestinal Viruses

    PubMed Central

    Martínez, Miguel A.; Soto-del Río, María de los Dolores; Gutiérrez, Rosa María; Chiu, Charles Y.; Greninger, Alexander L.; Contreras, Juan Francisco; López, Susana; Arias, Carlos F.

    2014-01-01

    Gastroenteritis is a clinical illness of humans and other animals that is characterized by vomiting and diarrhea and caused by a variety of pathogens, including viruses. An increasing number of viral species have been associated with gastroenteritis or have been found in stool samples as new molecular tools have been developed. In this work, a DNA microarray capable in theory of parallel detection of more than 100 viral species was developed and tested. Initial validation was done with 10 different virus species, and an additional 5 species were validated using clinical samples. Detection limits of 1 × 103 virus particles of Human adenovirus C (HAdV), Human astrovirus (HAstV), and group A Rotavirus (RV-A) were established. Furthermore, when exogenous RNA was added, the limit for RV-A detection decreased by one log. In a small group of clinical samples from children with gastroenteritis (n = 76), the microarray detected at least one viral species in 92% of the samples. Single infection was identified in 63 samples (83%), and coinfection with more than one virus was identified in 7 samples (9%). The most abundant virus species were RV-A (58%), followed by Anellovirus (15.8%), HAstV (6.6%), HAdV (5.3%), Norwalk virus (6.6%), Human enterovirus (HEV) (9.2%), Human parechovirus (1.3%), Sapporo virus (1.3%), and Human bocavirus (1.3%). To further test the specificity and sensitivity of the microarray, the results were verified by reverse transcription-PCR (RT-PCR) detection of 5 gastrointestinal viruses. The RT-PCR assay detected a virus in 59 samples (78%). The microarray showed good performance for detection of RV-A, HAstV, and calicivirus, while the sensitivity for HAdV and HEV was low. Furthermore, some discrepancies in detection of mixed infections were observed and were addressed by reverse transcription-quantitative PCR (RT-qPCR) of the viruses involved. It was observed that differences in the amount of genetic material favored the detection of the most abundant

  9. DNA microarray for detection of gastrointestinal viruses.

    PubMed

    Martínez, Miguel A; Soto-Del Río, María de Los Dolores; Gutiérrez, Rosa María; Chiu, Charles Y; Greninger, Alexander L; Contreras, Juan Francisco; López, Susana; Arias, Carlos F; Isa, Pavel

    2015-01-01

    Gastroenteritis is a clinical illness of humans and other animals that is characterized by vomiting and diarrhea and caused by a variety of pathogens, including viruses. An increasing number of viral species have been associated with gastroenteritis or have been found in stool samples as new molecular tools have been developed. In this work, a DNA microarray capable in theory of parallel detection of more than 100 viral species was developed and tested. Initial validation was done with 10 different virus species, and an additional 5 species were validated using clinical samples. Detection limits of 1 × 10(3) virus particles of Human adenovirus C (HAdV), Human astrovirus (HAstV), and group A Rotavirus (RV-A) were established. Furthermore, when exogenous RNA was added, the limit for RV-A detection decreased by one log. In a small group of clinical samples from children with gastroenteritis (n = 76), the microarray detected at least one viral species in 92% of the samples. Single infection was identified in 63 samples (83%), and coinfection with more than one virus was identified in 7 samples (9%). The most abundant virus species were RV-A (58%), followed by Anellovirus (15.8%), HAstV (6.6%), HAdV (5.3%), Norwalk virus (6.6%), Human enterovirus (HEV) (9.2%), Human parechovirus (1.3%), Sapporo virus (1.3%), and Human bocavirus (1.3%). To further test the specificity and sensitivity of the microarray, the results were verified by reverse transcription-PCR (RT-PCR) detection of 5 gastrointestinal viruses. The RT-PCR assay detected a virus in 59 samples (78%). The microarray showed good performance for detection of RV-A, HAstV, and calicivirus, while the sensitivity for HAdV and HEV was low. Furthermore, some discrepancies in detection of mixed infections were observed and were addressed by reverse transcription-quantitative PCR (RT-qPCR) of the viruses involved. It was observed that differences in the amount of genetic material favored the detection of the most abundant

  10. Estimating the granularity coefficient of a Potts-Markov random field within a Markov chain Monte Carlo algorithm.

    PubMed

    Pereyra, Marcelo; Dobigeon, Nicolas; Batatia, Hadj; Tourneret, Jean-Yves

    2013-06-01

    This paper addresses the problem of estimating the Potts parameter β jointly with the unknown parameters of a Bayesian model within a Markov chain Monte Carlo (MCMC) algorithm. Standard MCMC methods cannot be applied to this problem because performing inference on β requires computing the intractable normalizing constant of the Potts model. In the proposed MCMC method, the estimation of β is conducted using a likelihood-free Metropolis-Hastings algorithm. Experimental results obtained for synthetic data show that estimating β jointly with the other unknown parameters leads to estimation results that are as good as those obtained with the actual value of β. On the other hand, choosing an incorrect value of β can degrade estimation performance significantly. To illustrate the interest of this method, the proposed algorithm is successfully applied to real bidimensional SAR and tridimensional ultrasound images.

  11. The first documented controlled trial in history.

    PubMed

    Koren, Gideon

    2015-01-01

     The first reported controlled human trial was conducted 2500 years ago by the Biblical judge Gideon Ben Yoash, who challenged God's Angel: "I will put a fleece of wool on the threshing floor. If there is dew on the fleece only, and it is dry on all the ground, then I will know that Thou wilt deliver Israel through me, as Thou hast spoken". In the control part of the trial he asked the Angel to keep the wool dry while the ground around it will be soaked with morning dew. It is unfortunate that these principles were not practiced for thousands of years thereafter, as many medical challenges could have been solved earlier.  

  12. Water-quality assessment of part of the Upper Mississippi River Basin Study Unit, Minnesota and Wisconsin- Nutrients, chlorophyll a, phytoplankton, and suspended sediment in streams, 1996-98

    USGS Publications Warehouse

    Kroening, Sharon E.; Lee, Kathy E.; Goldstein, R.M.

    2003-01-01

    The greatest chlorophyll-a concentrations and algal abundances generally were measured in the Little Cobb River near Beauford, Minnesota; Minnesota River near Jordan, Minnesota; Mississippi River at Hastings, Minnesota; and the Mississippi River at Red Wing, Minnesota. Greater concentrations and algal abundances at these sites may have been the result of increased nitrogen and phosphorus concentrations. Total phosphorus concentrations at these sites most frequently exceeded the goal of 0.1 mg/L set by the USEPA to prevent eutrophication. Phytoplankton communities at these sites primarily were dominated by blue-green algae during the summer of 1996. In contrast, at most of the other sites, the phytoplankton community was dominated by diatoms.

  13. Constraints on topological order in mott insulators.

    PubMed

    Zaletel, Michael P; Vishwanath, Ashvin

    2015-02-20

    We point out certain symmetry induced constraints on topological order in Mott insulators (quantum magnets with an odd number of spin 1/2 moments per unit cell). We show, for example, that the double-semion topological order is incompatible with time reversal and translation symmetry in Mott insulators. This sharpens the Hastings-Oshikawa-Lieb-Schultz-Mattis theorem for 2D quantum magnets, which guarantees that a fully symmetric gapped Mott insulator must be topologically ordered, but is silent about which topological order is permitted. Our result applies to the kagome lattice quantum antiferromagnet, where recent numerical calculations of the entanglement entropy indicate a ground state compatible with either toric code or double-semion topological order. Our result rules out the latter possibility.

  14. Markov Chain Monte Carlo estimation for Bayesian approach based on right censored data

    NASA Astrophysics Data System (ADS)

    Ahmed, Alomari Mohammed

    2014-06-01

    This study consider the estimation of Maximum Likelihood Estimator and the Bayesian Estimator using Jeffreys prior and extension of Jeffreys prior information of the Weibull distribution with right censored data. The shape parametric estimation by maximum likelihood method is not available in closed forms, although it can be solved by numerical methods. Moreover, the Bayesian estimates of the parameters, the survival and hazard functions can not be solved analytically. Hence Markov Chain Monte Carlo method is used, where the full conditional distribution for the scale and shape parameters are obtained via Gibbs sampling and Metropolis-Hastings algorithm followed by the survival and hazard functions estimates. The methods are compared to maximum likelihood counterparts and the comparisons are made with respect to the Mean Square Error (MSE) and absolute bias to determine the best method in parameters, the survival and the hazard functions.

  15. Application of Thermo-Mechanical Measurements of Plastic Packages for Reliability Evaluation of PEMS

    NASA Technical Reports Server (NTRS)

    Sharma, Ashok K.; Teverovsky, Alexander

    2004-01-01

    Thermo-mechanical analysis (TMA) is typically employed for measurements of the glass transition temperature (Tg) and coefficients of thermal expansion (CTE) in molding compounds used in plastic encapsulated microcircuits (PEMs). Application of TMA measurements directly to PEMs allows anomalies to be revealed in deformation of packages with temperature, and thus indicates possible reliability concerns related to thermo-mechanical integrity and stability of the devices. In this work, temperature dependencies of package deformation were measured in several types of PEMs that failed environmental stress testing including temperature cycling, highly accelerated stress testing (HAST) in humid environments, and bum-in (BI) testing. Comparison of thermo-mechanical characteristics of packages and molding compounds in the failed parts allowed for explanation of the observed failures. The results indicate that TMA of plastic packages might be used for quality evaluation of PEMs intended for high-reliability applications.

  16. The first rite of passage: baptism in medieval memory.

    PubMed

    Deller, William S

    2011-01-01

    This article is part of a wider study that examines over 10,000 jurors' testimonies in proof-of-age hearings from 1246 to 1432, which were conducted to determine the legal majority of heirs-in-chief of the crown. It looks specifically at more than 1,500 references to the ceremony of baptism and tries to build up a picture of what the service was like in the memories of the participants. It reveals the haste and sometimes confusion of the preparations beforehand, the naming of infants, the role of godparents, the use of writing and the giving of gifts to record the birth, the celebrations that accompanied it, and details of the ceremonial itself, including the processions with lit torches and the crowds that often gathered. Despite the stereotypical nature of much testimony, it attempts to capture the atmosphere of what went on and what stuck in the minds of jurors.

  17. A world without Roe: how different would it be?

    PubMed

    Glendon, M A

    1989-01-01

    In anticipation of the U.S. Supreme Court's decision in Webster v. Reproductive Health Services (3 Jul 1989), this issue of the Hastings Center Report includes articles by Glendon, M. Mahowald, and N. Rhoden under the unifying title "Abortion: searching for common ground." Each author acknowledges the polarization of public and political opinion after the Court's 1973 Roe v. Wade decision, and seeks to establish a common ground in the abortion debate upon which a regulatory structure could be built. Glendon, author of the monograph Abortion and Divorce in Western Law: American Failures, European Challenges (Harvard; 1987), describes Roe as the most permissive abortion law in the industrializled West. She suggests that the United States might look to European laws as models where experience has shown that political compromise is possible when regulating abortion in countries where public opinion on the issue is deeply divided.

  18. Can others exercise an incapacitated patient's right to die?

    PubMed

    Ellman, I M

    1990-01-01

    Ellman's article is one of four in this issue of the Hastings Center Report on the first right to die case to come before the U.S. Supreme Court. The author, a law professor, agrees with critics that the Missouri Supreme Court erred in Cruzan when it declined to grant the parents of a woman in a persistent vegetative state authority to halt her tube feedings. However, he believes that in order to overturn Cruzan, the U.S. Supreme Court would have to wrongly and dangerously hold that Missouri is obliged to follow the family's instructions, even if Cruzan's wishes are unknown. Ellman warns against recognizing a third party's claim to exercise an individual's constitutional right to decide about medical care on her behalf. He argues that this right, emerging from a principle of self determination, can apply only to decisions concerning oneself, and cannot be exercised by another.

  19. Semiparametric Bayesian inference on skew-normal joint modeling of multivariate longitudinal and survival data.

    PubMed

    Tang, An-Min; Tang, Nian-Sheng

    2015-02-28

    We propose a semiparametric multivariate skew-normal joint model for multivariate longitudinal and multivariate survival data. One main feature of the posited model is that we relax the commonly used normality assumption for random effects and within-subject error by using a centered Dirichlet process prior to specify the random effects distribution and using a multivariate skew-normal distribution to specify the within-subject error distribution and model trajectory functions of longitudinal responses semiparametrically. A Bayesian approach is proposed to simultaneously obtain Bayesian estimates of unknown parameters, random effects and nonparametric functions by combining the Gibbs sampler and the Metropolis-Hastings algorithm. Particularly, a Bayesian local influence approach is developed to assess the effect of minor perturbations to within-subject measurement error and random effects. Several simulation studies and an example are presented to illustrate the proposed methodologies. PMID:25404574

  20. A Markov-Chain Monte-Carlo Based Method for Flaw Detection in Beams

    SciTech Connect

    Glaser, R E; Lee, C L; Nitao, J J; Hickling, T L; Hanley, W G

    2006-09-28

    A Bayesian inference methodology using a Markov Chain Monte Carlo (MCMC) sampling procedure is presented for estimating the parameters of computational structural models. This methodology combines prior information, measured data, and forward models to produce a posterior distribution for the system parameters of structural models that is most consistent with all available data. The MCMC procedure is based upon a Metropolis-Hastings algorithm that is shown to function effectively with noisy data, incomplete data sets, and mismatched computational nodes/measurement points. A series of numerical test cases based upon a cantilever beam is presented. The results demonstrate that the algorithm is able to estimate model parameters utilizing experimental data for the nodal displacements resulting from specified forces.

  1. A Bayesian Approach to Learning Scoring Systems.

    PubMed

    Ertekin, Şeyda; Rudin, Cynthia

    2015-12-01

    We present a Bayesian method for building scoring systems, which are linear models with coefficients that have very few significant digits. Usually the construction of scoring systems involve manual effort-humans invent the full scoring system without using data, or they choose how logistic regression coefficients should be scaled and rounded to produce a scoring system. These kinds of heuristics lead to suboptimal solutions. Our approach is different in that humans need only specify the prior over what the coefficients should look like, and the scoring system is learned from data. For this approach, we provide a Metropolis-Hastings sampler that tends to pull the coefficient values toward their "natural scale." Empirically, the proposed method achieves a high degree of interpretability of the models while maintaining competitive generalization performances. PMID:27441407

  2. Committees

    NASA Astrophysics Data System (ADS)

    Williams, Gwyn P.; Revesz, Peter; Arp, Uwe

    2014-03-01

    Conference Chairs NameOrganization Gwyn Williams Jefferson Lab Peter ReveszCornell High Energy Synchrotron Source Uwe ArpSynchrotron Ultraviolet Radiation Facility Programme Committee NameOrganization Alastair MacDowellAdvanced Light Source Tom ToellnerAdvanced Photon Source Amitava D RoyCenter for Advanced Microstructures and Devices Tom EllisCanadian Light Source Roberta SantarosaLaboratório Nacional de Luz Síncrotron Jerry (Jerome) HastingsLinac Coherent Light Source Steven HulbertNational Synchrotron Light Source Thomas A RabedeauStanford Synchrotron Radiation Lightsource Mark BissenSynchrotron Radiation Center Gwyn WilliamsJefferson Lab Peter ReveszCornell High Energy Synchrotron Source Uwe ArpSynchrotron Ultraviolet Radiation Facility

  3. Constraints on topological order in mott insulators.

    PubMed

    Zaletel, Michael P; Vishwanath, Ashvin

    2015-02-20

    We point out certain symmetry induced constraints on topological order in Mott insulators (quantum magnets with an odd number of spin 1/2 moments per unit cell). We show, for example, that the double-semion topological order is incompatible with time reversal and translation symmetry in Mott insulators. This sharpens the Hastings-Oshikawa-Lieb-Schultz-Mattis theorem for 2D quantum magnets, which guarantees that a fully symmetric gapped Mott insulator must be topologically ordered, but is silent about which topological order is permitted. Our result applies to the kagome lattice quantum antiferromagnet, where recent numerical calculations of the entanglement entropy indicate a ground state compatible with either toric code or double-semion topological order. Our result rules out the latter possibility. PMID:25763971

  4. Optimal timing for managed relocation of species faced with climate change

    NASA Astrophysics Data System (ADS)

    McDonald-Madden, Eve; Runge, Michael C.; Possingham, Hugh P.; Martin, Tara G.

    2011-08-01

    Managed relocation is a controversial climate-adaptation strategy to combat negative climate change impacts on biodiversity. While the scientific community debates the merits of managed relocation, species are already being moved to new areas predicted to be more suitable under climate change. To inform these moves, we construct a quantitative decision framework to evaluate the timing of relocation in the face of climate change. We find that the optimal timing depends on many factors, including the size of the population, the demographic costs of translocation and the expected carrying capacities over time in the source and destination habitats. In some settings, such as when a small population would benefit from time to grow before risking translocation losses, haste is ill advised. We also find that active adaptive management is valuable when the effect of climate change on source habitat is uncertain, and leads to delayed movement.

  5. Modeling association among demographic parameters in analysis of open population capture?recapture data

    USGS Publications Warehouse

    Link, W.A.; Barker, R.J.

    2005-01-01

    We present a hierarchical extension of the Cormack?Jolly?Seber (CJS) model for open population capture?recapture data. In addition to recaptures of marked animals, we model first captures of animals and losses on capture. The parameter set includes capture probabilities, survival rates, and birth rates. The survival rates and birth rates are treated as a random sample from a bivariate distribution, thus the model explicitly incorporates correlation in these demographic rates. A key feature of the model is that the likelihood function, which includes a CJS model factor, is expressed entirely in terms of identifiable parameters; losses on capture can be factored out of the model. Since the computational complexity of classical likelihood methods is prohibitive, we use Markov chain Monte Carlo in a Bayesian analysis. We describe an efficient candidate-generation scheme for Metropolis?Hastings sampling of CJS models and extensions. The procedure is illustrated using mark-recapture data for the moth Gonodontis bidentata.

  6. An application of Bayesian inference for solar-like pulsators

    NASA Astrophysics Data System (ADS)

    Benomar, O.

    2008-12-01

    As the amount of data collected by space-borne asteroseismic instruments (such as CoRoT and Kepler) increases drastically, it will be useful to have automated processes to extract a maximum of information from these data. The use of a Bayesian approach could be very help- ful for this goal. Only a few attempts have been made in this way (e.g. Brewer et al. 2007). We propose to use Markov Chain Monte Carlo simulations (MCMC) with Metropolis-Hasting (MH) based algorithms to infer the main stellar oscillation parameters from the power spec- trum, in the case of solar-like pulsators. Given a number of modes to be fitted, the algorithm is able to give the best set of parameters (frequency, linewidth, amplitude, rotational split- ting) corresponding to a chosen input model. We illustrate this algorithm with one of the first CoRoT targets: HD 49933.

  7. 31. WEST TO PARTS AND TOOLS LOCATED DIRECTLY OPPOSITE FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. WEST TO PARTS AND TOOLS LOCATED DIRECTLY OPPOSITE FROM THE BLACKSMITH SHOP AREA IN THE NORTHEAST QUADRANT OF THE FACTORY. ON THE FLOOR AT THE LEFT SIDE IS A MANUAL PIPE THREADER FOR LARGE-DIAMETER PIPE (AS DROP PIPE IN WELLS FOR WATER SYSTEMS). BENEATH THE BENCH ARE UNMACHINED NEW OLD STOCK MAIN CASTINGS FOR ELI WINDMILLS, TOGETHER WITH A USED MAIN SHAFT/WHEEL HUB/CRANK PLATE ASSEMBLY WITH 1920S-1930S OIL RESERVOIR FROM ELI WINDMILL. THE CIRCULAR CASTING WITH CRESCENT-SHAPED PATTERNS IS A PORTION OF THE CAM MECHANISM FROM A 'WESTERN GEARED GEARLESS' WINDMILL MADE BY THE WESTERN LAND ROLLER CO., HASTINGS, NEB. TO THE RIGHT ON THE BENCH IS A GEARED TIRE BENDER USED TO GIVE CURVATURE TO WHEEL RIMS OF ELI WINDMILLS. IN THE BACKGROUND ARE ... - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  8. Optimal timing for managed relocation of species faced with climate change

    USGS Publications Warehouse

    McDonald Madden, Eve; Runge, Michael C.; Possingham, Hugh P.; Martin, Tara G.

    2011-01-01

    Managed relocation is a controversial climate-adaptation strategy to combat negative climate change impacts on biodiversity. While the scientific community debates the merits of managed relocation, species are already being moved to new areas predicted to be more suitable under climate change. To inform these moves, we construct a quantitative decision framework to evaluate the timing of relocation in the face of climate change. We find that the optimal timing depends on many factors, including the size of the population, the demographic costs of translocation and the expected carrying capacities over time in the source and destination habitats. In some settings, such as when a small population would benefit from time to grow before risking translocation losses, haste is ill advised. We also find that active adaptive management is valuable when the effect of climate change on source habitat is uncertain, and leads to delayed movement.

  9. A Bayesian Approach to Learning Scoring Systems.

    PubMed

    Ertekin, Şeyda; Rudin, Cynthia

    2015-12-01

    We present a Bayesian method for building scoring systems, which are linear models with coefficients that have very few significant digits. Usually the construction of scoring systems involve manual effort-humans invent the full scoring system without using data, or they choose how logistic regression coefficients should be scaled and rounded to produce a scoring system. These kinds of heuristics lead to suboptimal solutions. Our approach is different in that humans need only specify the prior over what the coefficients should look like, and the scoring system is learned from data. For this approach, we provide a Metropolis-Hastings sampler that tends to pull the coefficient values toward their "natural scale." Empirically, the proposed method achieves a high degree of interpretability of the models while maintaining competitive generalization performances.

  10. Lessons not yet learned from the Fukushima disaster

    NASA Astrophysics Data System (ADS)

    Klügel, Jens-Uwe

    2014-05-01

    The Fukushima nuclear catastrophe has led to a wide-spread international discussion on how seismic and tsunami hazards can be better predicted and adverse consequences be prevented.In some countries the event led to the complete phase-out of nuclear energy. The lessons drawn by different organisations including earth scientists, earthquake engineers,non-governmental and governmental organisations will be reviewed from an independent position. This review captures the following areas: 1) Hazard assessment 2) Engineering design and defense in depth concepts 3) Emergency preparedness It is shown that not all important lessons from the catastrophe have been drawn. Especially the need of an holistic approach towards hazard assessment and the implementation of defense in depth and diversity of design principles for critical infrastructures like nuclear power plants hast to be stronger emphasized to prevent similar disasters.

  11. Italy: pluralism takes root.

    PubMed

    Mori, Maurizio

    1987-06-01

    Mori gives an overview of biomedical ethics in Italy in one of four Hastings Center Report country reports. Public policy on issues like in vitro fertilization, sterilization and abortion, passive euthanasia, and organ transplantation reflects the declining influence of the Catholic Church and the increasing cultural pluralism of Italian society. The government has appointed advisory bodies on reproductive technologies and AIDS to study the issues and make recommendations. Bills regulating technologies such as in vitro fertilization or liberalizing restrictive laws such as those on contraception are introduced regularly in Parliament, if not always enacted. Mori concludes that general interest in and formal study and discussion of biomedical ethics is increasing in Italy. He sees a danger that the field of bioethics will develop a dual identity, with little progress made in resolving the issues, unless serious dialogue between Catholics and non-Catholics increases. PMID:11644031

  12. Issues facing nurse teachers on the pre-registration diploma of higher education course (Project 2000): a case study approach.

    PubMed

    Camiah, S

    1997-06-01

    This paper draws on the experience and expertise of nurse practitioners and teachers of nurses to report on significant issues facing the latter in their work. The findings form part of a larger study describing major changes in the role and work of nurse teachers resulting from Project 2000 initiatives. The rationale for adapting a case study approach is outlined. The results indicate that changes in the work of nurse teachers and diversity of activities expected has placed some major obstacles in their work. Nurse teachers were perhaps inadequately prepared for their new roles, given the haste required by the demonstration nursing schools in their curricular submission documents in order to compete for approved course recognition (Project 2000) and demonstration status. The study recommends extensive staff support, development and academic growth, and continuing commitment to steady progress and change.

  13. A compromise on abortion?

    PubMed

    Rhoden, N K

    1989-01-01

    Rhoden's article is one of three on "Abortion: searching for common ground" in this issue of the Hastings Center Report. Her article, together with those by M. Mahowald and M. Glendon, was prompted by the expectation that the impending U.S. Supreme Court decision in Webster v. Reproductive Health Services (3 July 1989) would overturn or restrict Roe v. Wade (1973). Rhoden, an advocate for the pro-choice position, asks whether a compromise leading to an acceptable regulatory policy is possible or desirable among those on opposite sides of the abortion issue. She identifies several reasons why the Roe decision is vulnerable to review, but argues that effective education about sexuality and comprehensive social support of women are better approaches to abortion than restrictive legislation. PMID:2663778

  14. A world without Roe: how different would it be?

    PubMed

    Glendon, M A

    1989-01-01

    In anticipation of the U.S. Supreme Court's decision in Webster v. Reproductive Health Services (3 Jul 1989), this issue of the Hastings Center Report includes articles by Glendon, M. Mahowald, and N. Rhoden under the unifying title "Abortion: searching for common ground." Each author acknowledges the polarization of public and political opinion after the Court's 1973 Roe v. Wade decision, and seeks to establish a common ground in the abortion debate upon which a regulatory structure could be built. Glendon, author of the monograph Abortion and Divorce in Western Law: American Failures, European Challenges (Harvard; 1987), describes Roe as the most permissive abortion law in the industrializled West. She suggests that the United States might look to European laws as models where experience has shown that political compromise is possible when regulating abortion in countries where public opinion on the issue is deeply divided. PMID:2745061

  15. Diffusion Processes on Power-Law Small-World Networks

    NASA Astrophysics Data System (ADS)

    Kozma, Balazs; Hastings, Matthew B.; Korniss, G.

    2005-03-01

    We consider diffusion driven processes on power-law small-world networks: a random walk process related to folded polymers and surface growth related to synchronization problems. The random links introduced in small-world networks often lead to mean-field coupling (as if the random links were annealed) but in some systems mean-field predictions break down, like diffusion in one dimension. This break-down can be understood treating the random links perturbatively where the mean field prediction appears as the lowest order term of a naive perturbation expansion. Our results were obtained using self-consistent perturbation theory ootnotetextB. Kozma, M. B. Hastings, and G. Korniss, Phys. Rev. Lett. 92, 108701 (2004). and can also be understood in terms of a scaling theory. We find a rich phase diagram, with different transient and recurrent phases, including a critical line with continuously varying exponents.

  16. Is there life after Roe v. Wade?

    PubMed

    Mahowald, M B

    1989-01-01

    Mahowald's article is one of three in this issue of the Hastings Center Report under the overall title of "Abortion: searching for common ground." The articles were occasioned by the impending U.S. Supreme Court decision in Webster v. Reproductive Health Services (decided 3 Jul 1989), which was widely regarded as the Court's reconsideration of Roe v. Wade (1973). The debate in the United States over abortion has become intransigent and polarized since Roe, and the HCR articles by Mahowald, M. Glendon, and N. Rhoden represent an effort to find areas of agreement between advocates on both sides of the abortion question. Mahowald identifies several points of convergence and proposes modifications to Roe that might better accommodate competing interests of woman, fetus, and society.

  17. Generalized Dynamic Factor Models for Mixed-Measurement Time Series

    PubMed Central

    Cui, Kai; Dunson, David B.

    2013-01-01

    In this article, we propose generalized Bayesian dynamic factor models for jointly modeling mixed-measurement time series. The framework allows mixed-scale measurements associated with each time series, with different measurements having different distributions in the exponential family conditionally on time-varying latent factor(s). Efficient Bayesian computational algorithms are developed for posterior inference on both the latent factors and model parameters, based on a Metropolis Hastings algorithm with adaptive proposals. The algorithm relies on a Greedy Density Kernel Approximation (GDKA) and parameter expansion with latent factor normalization. We tested the framework and algorithms in simulated studies and applied them to the analysis of intertwined credit and recovery risk for Moody’s rated firms from 1982–2008, illustrating the importance of jointly modeling mixed-measurement time series. The article has supplemental materials available online. PMID:24791133

  18. Qatar: Energy and development

    SciTech Connect

    El Mallakh, R.

    1985-01-01

    Despite the traumas that have been experienced in the Arabian Gulf over the past five years, Qatar has been remarkably successful in smoothing the transition of its economy from recession and oil glut to recovery and stabilization. This book examines the characteristics of Qatar's economic and social development that have assisted this process. These characteristics include; moderation in the development policy and the avoidance of excessive haste; a cohesive sense of political identity; and a relatively well educated labor force derived from an educational program that was in place prior to the oil boom. Qatar has also maintained a moderate policy within OPEC. During the price hikes of 1979-80, caused by cutbacks in Iranian exports, Qatar maintained its policy of restraint; this was an important factor in permitting Qatar to confront the substantial drop in oil-generated revenues faced by all the oil exporters in 1982-84.

  19. Where Shall We Go?

    PubMed

    Kaebnick, Gregory E

    2016-09-01

    This issue of the Hastings Center Report coincides with the annual conference of the American Society for Bioethics and Humanities, whose theme this year is "Where do we stand?" The issue addresses that theme with the article by Debra Mathews and colleagues and the set of brief response essays that follow it. Mathews et al., drawing on work carried out by the Association of Bioethics Program Directors, pose questions about how to understand and evaluate the worth of bioethics research. Those questions require them to think very broadly about what bioethics is, in the first place, and how it is related to medicine, health policy, science, and society generally. In short, they are thinking at the highest level about the question, where do we stand? PMID:27649818

  20. Modeling interdependent animal movement in continuous time.

    PubMed

    Niu, Mu; Blackwell, Paul G; Skarin, Anna

    2016-06-01

    This article presents a new approach to modeling group animal movement in continuous time. The movement of a group of animals is modeled as a multivariate Ornstein Uhlenbeck diffusion process in a high-dimensional space. Each individual of the group is attracted to a leading point which is generally unobserved, and the movement of the leading point is also an Ornstein Uhlenbeck process attracted to an unknown attractor. The Ornstein Uhlenbeck bridge is applied to reconstruct the location of the leading point. All movement parameters are estimated using Markov chain Monte Carlo sampling, specifically a Metropolis Hastings algorithm. We apply the method to a small group of simultaneously tracked reindeer, Rangifer tarandus tarandus, showing that the method detects dependency in movement between individuals. PMID:26812666

  1. [Mourning and depression, from the attachment theory perspective].

    PubMed

    Wolfberg, Elsa; Ekboir, Alberto; Faiman, Graciela; Finzi, Josefina; Freedman, Margarita; Heath, Adela; Martínez de Cipolatti, María C

    2011-01-01

    Since depression, according to OMS, is such a worldwide condition, it is necessary to be able to distinguish a normal mourning from a pathological mourning and a depression, so as to qualify patients and health professionals to be able to support a normal mourning without medicating it nor hurrying (hasting) it, as well as being able to treat a depression adequately when it appears as a complication. Attachment theory focuses on mourning after loss with notions such as 1- acceptance of search for the lost person as a normal fact; 2- that mourning in children may have non-pathological outcomes; 3- that a non-processed mourning may be transmitted in an intergenerational way, and 4- also defines which elements may determine a pathological mourning or a depression. A clinical case is presented with an analysis of these notions.

  2. Reproductive technology: in the Netherlands, tolerance and debate.

    PubMed

    De Wachter, Maurice A M; De Wert, Guido MWR

    1987-06-01

    Two ethicists from the Netherlands' Institute for Bioethics file a report on their country in one of six Hastings Center Report articles on the status of reproductive technologies around the world. The situation in the Netherlands reflects the tolerant attitudes of the Dutch toward what are regarded as private matters. Artificial insemination, in vitro fertilization, and surrogate motherhood are available, and research on embryos is in the planning stages. Facilities offering reproductive services are regulated by the Minister of Health, with advice from the independent Health Council on Artificial Reproduction, the National Council for Public Health, and various insurance companies and professional medical organizations. Public policy debates center around such issues as the value of parenthood; involvement of third parties; secrecy about a child's genetic origins; privacy for semen, ovum, and embryo donors; access to services; and insurance coverage of treatment.

  3. Reproductive technology: in Japan, consensus has limits.

    PubMed

    Bai, Koichi; Shirai, Yasuko; Ishii, Michiko

    1987-06-01

    As part of a Hastings Center Report series of six articles on reproductive technologies around the world, three Japanese scholars report on the situation in their country. At present, artificial insemination and in vitro fertilization are offered to infertile married couples, and research is performed on early embryos up to 14 days after fertilization. Neither surrogate mothers nor donated gametes are used in Japan. Bai, Shirai, and Ishii identify several issues that they believe merit further public debate, among them the legal status of AID children, the experimental nature of in vitro fertilization, genetic manipulation of embryos, and gender selection. They summarize the findings of four opinion surveys that show a lack of consensus among the Japanese on the acceptability of reproductive technologies, which in the words of the authors "create a tension and a link between traditional belief and contemporary practice."

  4. Nurses at the Table.

    PubMed

    Ulrich, Connie M

    2016-09-01

    Few bioethicists are educated with a view into nursing. Thus, much of the conceptual and empirical research on ethical issues in nursing practice has been conducted by nurse ethicists themselves and, to a lesser degree, by individuals with a strong interest in nursing ethics. Although this work has internally shaped nursing practice, education, and policy, the broader field of bioethics has seldom examined and acknowledged the everyday ethical concerns of practicing nurses and their important contributions to bioethics discourse. In this special report of the Hastings Center Report -the first to focus on nursing-Christine Grady, Ann Hamric, and I, along with consulting editor Nancy Berlinger, strive to give voice to the contributions of nurses in addressing some of our obstinate everyday ethics and health policy challenges. PMID:27649914

  5. Wellpower: the foundation of innovation.

    PubMed

    Richards, Kim

    2013-01-01

    The financial and human costs of compassion fatigue and burnout can be devastating. In the haste to "get more done," are we hardwiring our caregivers for disaster? The lifestyle choices we make and the degree of self-care we practice are paramount to not only our individual quality and quantity of life and our immediate circle of influence but holds the profound potential to create quantum change within our health care system. For nurses, who are the most influential force for health care reform in America, the time to emulate wellness has never been more critical. By creating healthy habits for ourselves, we flourish as ambassadors of self-care for our patients, families, colleagues, and communities. As we move forward with health care reform, the most powerful influence that we, as nurse leaders can wield is to practice regular self-care, healthy lifestyles, and preventative medicine.

  6. Water-quality assessment of part of the Upper Mississippi River Basin Study Unit, Minnesota and Wisconsin- Nutrients, chlorophyll a, phytoplankton, and suspended sediment in streams, 1996-98

    USGS Publications Warehouse

    Kroening, Sharon E.; Lee, Kathy E.; Goldstein, R.M.

    2003-01-01

    Most sites had pronounced seasonal variations in dissolved nitrite plus nitrate nitrogen and dissolved ammonia nitrogen concentrations. At most sites, dissolved nitrite plus nitrate nitrogen concentrations were greatest in the winter and spring and least during the summer and fall. In contrast, the greatest dissolved nitrite plus nitrate nitrogen concentrations in the Little Cobb River near Beauford, Minnesota; Minnesota River near Jordan, Minnesota; and Mississippi River at Hastings and Red Wing, Minnesota occurred during the spring and summer. These seasonal variations in dissolved nitrite plus nitrate nitrogen concentrations may be the result of nitrogen cycling in the soils, as well as crop uptake and hydrologic conditions. The greatest concentrations of dissolved ammonia nitrogen at all sites occurred in the winter and spring. The maximum contaminant level for nitrate of 10 milligrams per liter (mg/L) as nitrogen set by the U.S. Environmental Protection Agency (USEPA) for drinking water was exceeded in 20 percent of the

  7. Tronquée solutions of the painlevé II equation

    NASA Astrophysics Data System (ADS)

    Novokshenov, V. Yu.

    2012-08-01

    We study special solutions of the Painlevé II (PII) equation called tronquée solutions, i.e., those having no poles along one or more critical rays in the complex plane. They are parameterized by special monodromy data of the Lax pair equations. The manifold of the monodromy data for a general solution is a twodimensional complex manifold with one- and zero-dimensional singularities, which arise because there is no global parameterization of the manifold. We show that these and only these singularities (together with zeros of the parameterization) are related to the tronquée solutions of the PII equation. As an illustration, we consider the known Hastings-McLeod and Ablowitz-Segur solutions and some other solutions to show that they belong to the class of tronquée solutions and correspond to one or another type of singularity of the monodromy data.

  8. Tail decay for the distribution of the endpoint of a directed polymer

    NASA Astrophysics Data System (ADS)

    Bothner, Thomas; Liechty, Karl

    2013-05-01

    We obtain an asymptotic expansion for the tails of the random variable { T}=\\arg\\max_{u\\in{R}}(A_2(u)-u^2) where A_2 is the Airy2 process. Using the formula of Schehr (2012 J. Stat. Phys. 149 385) that connects the density function of { T} to the Hastings-McLeod solution to the second Painlevé equation, we prove that as t → ∞, {P}(|{ T}|>t)=C\\rme^{-\\frac{4}{3}\\varphi(t)}t^{-145/32}(1+O(t^{-3/4})) , where φ(t) = t3 - 2t3/2 + 3t3/4, and the constant C is given explicitly.

  9. Asymptotics of Tracy-Widom Distributions and the Total Integral of a Painlevé II Function

    NASA Astrophysics Data System (ADS)

    Baik, Jinho; Buckingham, Robert; Difranco, Jeffery

    2008-06-01

    The Tracy-Widom distribution functions involve integrals of a Painlevé II function starting from positive infinity. In this paper, we express the Tracy-Widom distribution functions in terms of integrals starting from minus infinity. There are two consequences of these new representations. The first is the evaluation of the total integral of the Hastings-McLeod solution of the Painlevé II equation. The second is the evaluation of the constant term of the asymptotic expansions of the Tracy-Widom distribution functions as the distribution parameter approaches minus infinity. For the GUE Tracy-Widom distribution function, this gives an alternative proof of the recent work of Deift, Its, and Krasovsky. The constant terms for the GOE and GSE Tracy-Widom distribution functions are new.

  10. Early childhood vaccination in two rural counties--Nebraska, 1991-1992.

    PubMed

    1992-09-18

    The national vaccination objectives for the year 2000 include increasing coverage for the recommended primary vaccination series* among children aged less than 2 years to at least 90% and to vaccinate at least 95% of school-aged children (1). Although baseline data for these two goals have been obtained in numerous urban settings (2), similar baseline data from rural populations are limited. To determine the vaccination status of children in rural Nebraska, where 51% (812,000) of Nebraska's residents live, the Nebraska Department of Health, in collaboration with Hastings College, conducted a retrospective study of school-aged children in grades kindergarten through six in two rural counties during the 1991-92 school year. This report summarizes the study findings.

  11. Bayesian inference with an adaptive proposal density for GARCH models

    NASA Astrophysics Data System (ADS)

    Takaishi, Tetsuya

    2010-04-01

    We perform the Bayesian inference of a GARCH model by the Metropolis-Hastings algorithm with an adaptive proposal density. The adaptive proposal density is assumed to be the Student's t-distribution and the distribution parameters are evaluated by using the data sampled during the simulation. We apply the method for the QGARCH model which is one of asymmetric GARCH models and make empirical studies for Nikkei 225, DAX and Hang indexes. We find that autocorrelation times from our method are very small, thus the method is very efficient for generating uncorrelated Monte Carlo data. The results from the QGARCH model show that all the three indexes show the leverage effect, i.e. the volatility is high after negative observations.

  12. Light cone matrix product

    SciTech Connect

    Hastings, Matthew B

    2009-01-01

    We show how to combine the light-cone and matrix product algorithms to simulate quantum systems far from equilibrium for long times. For the case of the XXZ spin chain at {Delta} = 0.5, we simulate to a time of {approx} 22.5. While part of the long simulation time is due to the use of the light-cone method, we also describe a modification of the infinite time-evolving bond decimation algorithm with improved numerical stability, and we describe how to incorporate symmetry into this algorithm. While statistical sampling error means that we are not yet able to make a definite statement, the behavior of the simulation at long times indicates the appearance of either 'revivals' in the order parameter as predicted by Hastings and Levitov (e-print arXiv:0806.4283) or of a distinct shoulder in the decay of the order parameter.

  13. Reproductive technology: in the Netherlands, tolerance and debate.

    PubMed

    De Wachter, Maurice A M; De Wert, Guido MWR

    1987-06-01

    Two ethicists from the Netherlands' Institute for Bioethics file a report on their country in one of six Hastings Center Report articles on the status of reproductive technologies around the world. The situation in the Netherlands reflects the tolerant attitudes of the Dutch toward what are regarded as private matters. Artificial insemination, in vitro fertilization, and surrogate motherhood are available, and research on embryos is in the planning stages. Facilities offering reproductive services are regulated by the Minister of Health, with advice from the independent Health Council on Artificial Reproduction, the National Council for Public Health, and various insurance companies and professional medical organizations. Public policy debates center around such issues as the value of parenthood; involvement of third parties; secrecy about a child's genetic origins; privacy for semen, ovum, and embryo donors; access to services; and insurance coverage of treatment. PMID:11644022

  14. Ethics committees -- 1990 and beyond: the genie out of the bottle?

    PubMed

    Cohen, Cynthia B

    1990-01-01

    The "Ethics committees" column in this issue of the Hasting Center Report features an introduction by Cynthia B. Cohen and four brief commentaries on the roles hospital ethics committees may play in the making of institutional and public health care policy in the 1990s. The implications for ethics committees of the pending federal Patient Self-Determination Act are discussed by John C. Fletcher in "The Patient Self-Determination Act: yes," and by Alexander Morgan Capron in "The Patient Self-Determination Act: not now." The pros and cons of a broader, more public role for ethics committees in reconciling the business and patient care aspects of health care delivery are debated by Cohen in "Ethics committees as corporate and public policy advocates," and by Philip Boyle in "Business ethics in ethics committees?" News items by Thomasine Kushner ("Networks across America") and Todd Sagin ("The Philadelphia story") conclude the column.

  15. Large-eddy simulation of flow around an airfoil on a structured mesh

    NASA Technical Reports Server (NTRS)

    Kaltenbach, Hans-Jakob; Choi, Haecheon

    1995-01-01

    The diversity of flow characteristics encountered in a flow over an airfoil near maximum lift taxes the presently available statistical turbulence models. This work describes our first attempt to apply the technique of large-eddy simulation to a flow of aeronautical interest. The challenge for this simulation comes from the high Reynolds number of the flow as well as the variety of flow regimes encountered, including a thin laminar boundary layer at the nose, transition, boundary layer growth under adverse pressure gradient, incipient separation near the trailing edge, and merging of two shear layers at the trailing edge. The flow configuration chosen is a NACA 4412 airfoil near maximum lift. The corresponding angle of attack was determined independently by Wadcock (1987) and Hastings & Williams (1984, 1987) to be close to 12 deg. The simulation matches the chord Reynolds number U(sub infinity)c/v = 1.64 x 10(exp 6) of Wadcock's experiment.

  16. A joint model for boundaries of multiple anatomical parts

    NASA Astrophysics Data System (ADS)

    Kerr, Grégoire; Kurtek, Sebastian; Srivastava, Anuj

    2011-03-01

    The use of joint shape analysis of multiple anatomical parts is a promising area of research with applications in medical diagnostics, growth evaluations, and disease characterizations. In this paper, we consider several features (shapes, orientations, scales, and locations) associated with anatomical parts and develop probability models that capture interactions between these features and across objects. The shape component is based on elastic shape analysis of continuous boundary curves. The proposed model is a second order model that considers principal coefficients in tangent spaces of joint manifolds as multivariate normal random variables. Additionally, it models interactions across objects using area-interaction processes. Using given observations of four anatomical parts: caudate, hippocampus, putamen and thalamus, on one side of the brain, we first estimate the model parameters and then generate random samples from them using the Metropolis-Hastings algorithm. The plausibility of these random samples validates the proposed models.

  17. Maximum-likelihood estimation of migration rates and effective population numbers in two populations using a coalescent approach.

    PubMed

    Beerli, P; Felsenstein, J

    1999-06-01

    A new method for the estimation of migration rates and effective population sizes is described. It uses a maximum-likelihood framework based on coalescence theory. The parameters are estimated by Metropolis-Hastings importance sampling. In a two-population model this method estimates four parameters: the effective population size and the immigration rate for each population relative to the mutation rate. Summarizing over loci can be done by assuming either that the mutation rate is the same for all loci or that the mutation rates are gamma distributed among loci but the same for all sites of a locus. The estimates are as good as or better than those from an optimized FST-based measure. The program is available on the World Wide Web at http://evolution.genetics. washington.edu/lamarc.html/.

  18. Adaptive Metropolis Sampling with Product Distributions

    NASA Technical Reports Server (NTRS)

    Wolpert, David H.; Lee, Chiu Fan

    2005-01-01

    The Metropolis-Hastings (MH) algorithm is a way to sample a provided target distribution pi(z). It works by repeatedly sampling a separate proposal distribution T(x,x') to generate a random walk {x(t)}. We consider a modification of the MH algorithm in which T is dynamically updated during the walk. The update at time t uses the {x(t' less than t)} to estimate the product distribution that has the least Kullback-Leibler distance to pi. That estimate is the information-theoretically optimal mean-field approximation to pi. We demonstrate through computer experiments that our algorithm produces samples that are superior to those of the conventional MH algorithm.

  19. Spain: from the decree to the proposal.

    PubMed

    Gracia, Diego

    1987-06-01

    This is one in a series of four country reports published together in the Hastings Center Report. Gracia, a bioethicist, compares health care policy before and after Franco's dictatorship. Under Franco, compulsory health insurance was enacted, and modern hospitals were built at the expense of primary services. Patient care was governed by the principle of beneficence "in its extreme and paternalistic sense." Medicine in the democratic post-Franco period has reflected changes in Spanish society as political freedom has led to an increased moral pluralism and the formation of public policy through debate and compromise. Gracia identifies three bioethical issues where changes in attitudes and policies have been the greatest: resource allocation, abortion, and organ transplantation. He concludes his report by briefly describing the role bioethics plays in public policy formation in Spain today. PMID:11644028

  20. Molecular dynamics simulations of field emission from a planar nanodiode

    SciTech Connect

    Torfason, Kristinn; Valfells, Agust; Manolescu, Andrei

    2015-03-15

    High resolution molecular dynamics simulations with full Coulomb interactions of electrons are used to investigate field emission in planar nanodiodes. The effects of space-charge and emitter radius are examined and compared to previous results concerning transition from Fowler-Nordheim to Child-Langmuir current [Y. Y. Lau, Y. Liu, and R. K. Parker, Phys. Plasmas 1, 2082 (1994) and Y. Feng and J. P. Verboncoeur, Phys. Plasmas 13, 073105 (2006)]. The Fowler-Nordheim law is used to determine the current density injected into the system and the Metropolis-Hastings algorithm to find a favourable point of emission on the emitter surface. A simple fluid like model is also developed and its results are in qualitative agreement with the simulations.

  1. Detection and molecular characterization of diarrhea causing viruses in single and mixed infections in children: a comparative study between Bangladesh and Turkey.

    PubMed

    Mitui, Marcelo Takahiro; Bozdayi, Gulendam; Ahmed, Selim; Matsumoto, Takashi; Nishizono, Akira; Ahmed, Kamruddin

    2014-07-01

    The incidence and mortality caused by diarrhea differ among countries. The prevalence of different enteric viruses, their molecular characteristics, and infections with multiple viruses might affect the disease incidence and mortality caused by diarrhea. The objective of this study was to determine the distribution and molecular characteristics of enteric viruses in children with diarrhea in Turkey and Bangladesh. A total of 288 stool samples that were negative for group A rotavirus were collected from children aged <5 years with acute diarrhea who presented to hospitals in Turkey and Bangladesh. The samples were screened for human bocavirus (HBoV), astrovirus (HAstV), norovirus (NoV), and adenovirus (AdV). Phylogenetic analyses of the targeted virus genes were performed. In Turkey, viruses were detected in 87/150 samples (58%), which included 69 (79.3%) with single viruses and 18 (20.7%) with multiple viruses. AdV was the most common virus, followed by HBoV. In Bangladesh, viruses were detected in 123/138 samples (89.1%), which included 29 (23.6%) with single viruses and 94 (76.4%) with multiple viruses. NoV GII was the most common, followed by AdV. The dominant genotypes among the virus species were HBoV 2A, HAstV 1, NoV GI type 1, and AdV 40. For NoV GII, the Hunter variant of genotype 4 in Turkey and genotype 17 in Bangladesh were the most common among the sequenced strains. It was concluded that the distribution of the viruses associated with diarrhea in Turkish and Bangladeshi children was different. Enteric viruses and mixed infections were more prevalent in Bangladesh than in Turkey. PMID:24105741

  2. CosmoHammer: Cosmological parameter estimation with the MCMC Hammer

    NASA Astrophysics Data System (ADS)

    Akeret, Joël; Seehars, Sebastian; Amara, Adam; Refregier, Alexandre; Csillaghy, André

    2013-08-01

    We study the benefits and limits of parallelised Markov chain Monte Carlo (MCMC) sampling in cosmology. MCMC methods are widely used for the estimation of cosmological parameters from a given set of observations and are typically based on the Metropolis-Hastings algorithm. Some of the required calculations can however be computationally intensive, meaning that a single long chain can take several hours or days to calculate. In practice, this can be limiting, since the MCMC process needs to be performed many times to test the impact of possible systematics and to understand the robustness of the measurements being made. To achieve greater speed through parallelisation, MCMC algorithms need to have short autocorrelation times and minimal overheads caused by tuning and burn-in. The resulting scalability is hence influenced by two factors, the MCMC overheads and the parallelisation costs. In order to efficiently distribute the MCMC sampling over thousands of cores on modern cloud computing infrastructure, we developed a Python framework called CosmoHammer which embeds emcee, an implementation by Foreman-Mackey et al. (2012) of the affine invariant ensemble sampler by Goodman and Weare (2010). We test the performance of CosmoHammer for cosmological parameter estimation from cosmic microwave background data. While Metropolis-Hastings is dominated by overheads, CosmoHammer is able to accelerate the sampling process from a wall time of 30 h on a dual core notebook to 16 min by scaling out to 2048 cores. Such short wall times for complex datasets open possibilities for extensive model testing and control of systematics.

  3. Structural inversion of the Tamworth Belt: Insights into the development of orogenic curvature in the southern New England Orogen, Australia

    NASA Astrophysics Data System (ADS)

    Phillips, G.; Robinson, J.; Glen, R.; Roberts, J.

    2016-05-01

    The middle to late Permian Hunter Bowen Event is credited with the development of orogenic curvature in the southern New England Orogen, yet contention surrounds the structural dynamics responsible for the development of this curvature. Debate is largely centred on the roles of orogen parallel strike-slip and orogen normal extension and contraction to explain the development of curvature. To evaluate the dynamic history of the Hunter Bowen Event, we present new kinematic reconstructions of the Tamworth Belt. The Tamworth Belt formed as a Carboniferous forearc basin and was subsequently inverted during the Hunter Bowen Event. Kinematic reconstructions of the Tamworth Belt are based on new maps and cross-sections built from a synthesis of best-available mapping, chronostratigraphic data and new interpretations of depth-converted seismic data. The following conclusions are made from our study: (i) the Hunter Bowen Event was dominantly driven by margin normal contraction (east-west shortening; present-day coordinates), and; (ii) variations in structural style along the strike of the Tamworth Belt can be explained by orthogonal vs. oblique inversion, which reflects the angular relationship between the principal shortening vector and continental-arc margin. Given these conclusions, we suggest that curvature around the controversial Manning Bend was influenced by the presence of primary curvature in the continental margin, and that the Hastings Block was translated along a sinistral strike-slip fault system that formed along this oblique (with respect to the regional east-west extension and convergence direction) part of the margin. Given the available temporal data, the translation of the Hastings Block took place in the Early Permian (Asselian) and therefore preceded the Hunter Bowen Event. Accordingly, we suggest that the Hunter Bowen Event was dominantly associated with enhancing curvature that was either primary in origin, or associated with fault block translation

  4. Evaluation of Data Retention and Imprint Characteristics of FRAMs Under Environmental Stresses for NASA Applications

    NASA Technical Reports Server (NTRS)

    Sharma, Asbok K.; Teverovsky, Alexander; Dowdy, Terry W.; Hamilton, Brett

    2002-01-01

    A major reliability issue for all advanced nonvolatile memory (NVM) technology devices including FRAMs is the data retention characteristics over extended period of time, under environmental stresses and exposure to total ionizing dose (TID) radiation effects. For this testing, 256 Kb FRAMs in 28-pin plastic DIPS, rated for industrial grade temperature range of -40 C to +85 C, were procured. These are two-transistor, two-capacitor (2T-2C) design FRAMs. In addition to data retention characteristics, the parts were also evaluated for imprint failures, which are defined as the failure of cells to change from a "preferred" state, where it has been for a significant period of time to an opposite state (e.g., from 1 to 0, or 0 to 1). These 256 K FRAMs were subjected to scanning acoustic microscopy (C-SAM); 1,000 temperature cycles from -65 C to +150 C; high temperature aging at 150 C, 175 C, and 200 C for 1,000 hours; highly accelerated stress test (HAST) for 500 hours; 1,000 hours of operational life test at 125 C; and total ionizing dose radiation testing. As a preconditioning, 10 K read/write cycles were performed on all devices. Interim electrical measurements were performed throughout this characterization, including special imprint testing and final electrical testing. Some failures were observed during high temperature aging test at 200 C, during HAST testing, and during 1,000 hours of operational life at 125 C. The parts passed 10 Krad exposure, but began showing power supply current increases during the dose increment from 10 Krad to 30 Krad, and at 40 Krad severe data retention and parametric failures were observed. Failures from various environmental group testing are currently being analyzed.

  5. Evaluation of Data Retention and Imprint Characteristics of FRAMs Under Environmental Stresses for NASA Applications

    NASA Technical Reports Server (NTRS)

    Sharma, Ashok K.; Teverovsky, Alexander; Dowdy, Terry W.; Hamilton, Brett

    2000-01-01

    A major reliability issue for all advanced nonvolatile memory (NVM) technology devices including FRAMs (Ferroelectric random access memories) is the data retention characteristics over extended period of time, under environmental stresses and exposure to total ionizing dose (TID) radiation effects. For this testing, 256 Kb FRAMs in 28-pin plastic DIPS, rated for industrial grade temperature range of -40 C to +85 C, were procured. These are two-transistor, two-capacitor (2T-2C) design FRAMs. In addition to data retention characteristics, the parts were also evaluated for imprint failures, which are defined as the failure of cells to change from a "preferred" state, where it has been for a significant period of time to an opposite state (e.g., from 1 to 0, or 0 to 1). These 256 K FRAMs were subjected to scanning acoustic microscopy (C-SAM); 1,000 temperature cycles from -65 C to +150 C; high temperature aging at 150 C, 175 C, and 200 C for 1,000 hours; highly accelerated stress test (HAST) for 500 hours; 1,000 hours of operational life test at 125 C; and total ionizing dose radiation testing. As a preconditioning, 10 K read/write cycles were performed on all devices. Interim electrical measurements were performed throughout this characterization, including special imprint testing and final electrical testing. Some failures were observed during high temperature aging test at 200 C, during HAST testing, and during 1,000 hours of operational life at 125 C. The parts passed 10 Krad exposure, but began showing power supply current increases during the dose increment from 10 Krad to 30 Krad, and at 40 Krad severe data retention and parametric failures were observed. Failures from various environmental group testing are currently being analyzed.

  6. Exponential Decay of Correlations Implies Area Law

    NASA Astrophysics Data System (ADS)

    Brandão, Fernando G. S. L.; Horodecki, Michał

    2015-01-01

    We prove that a finite correlation length, i.e., exponential decay of correlations, implies an area law for the entanglement entropy of quantum states defined on a line. The entropy bound is exponential in the correlation length of the state, thus reproducing as a particular case Hastings's proof of an area law for groundstates of 1D gapped Hamiltonians. As a consequence, we show that 1D quantum states with exponential decay of correlations have an efficient classical approximate description as a matrix product state of polynomial bond dimension, thus giving an equivalence between injective matrix product states and states with a finite correlation length. The result can be seen as a rigorous justification, in one dimension, of the intuition that states with exponential decay of correlations, usually associated with non-critical phases of matter, are simple to describe. It also has implications for quantum computing: it shows that unless a pure state quantum computation involves states with long-range correlations, decaying at most algebraically with the distance, it can be efficiently simulated classically. The proof relies on several previous tools from quantum information theory—including entanglement distillation protocols achieving the hashing bound, properties of single-shot smooth entropies, and the quantum substate theorem—and also on some newly developed ones. In particular we derive a new bound on correlations established by local random measurements, and we give a generalization to the max-entropy of a result of Hastings concerning the saturation of mutual information in multiparticle systems. The proof can also be interpreted as providing a limitation on the phenomenon of data hiding in quantum states.

  7. The Lake Charles CCS Project

    SciTech Connect

    Doug Cathro

    2010-06-30

    The Lake Charles CCS Project is a large-scale industrial carbon capture and sequestration (CCS) project which will demonstrate advanced technologies that capture and sequester carbon dioxide (CO{sub 2}) emissions from industrial sources into underground formations. Specifically the Lake Charles CCS Project will accelerate commercialization of large-scale CO{sub 2} storage from industrial sources by leveraging synergy between a proposed petroleum coke to chemicals plant (the LCC Gasification Project) and the largest integrated anthropogenic CO{sub 2} capture, transport, and monitored sequestration program in the U.S. Gulf Coast Region. The Lake Charles CCS Project will promote the expansion of EOR in Texas and Louisiana and supply greater energy security by expanding domestic energy supplies. The capture, compression, pipeline, injection, and monitoring infrastructure will continue to sequester CO{sub 2} for many years after the completion of the term of the DOE agreement. The objectives of this project are expected to be fulfilled by working through two distinct phases. The overall objective of Phase 1 was to develop a fully definitive project basis for a competitive Renewal Application process to proceed into Phase 2 - Design, Construction and Operations. Phase 1 includes the studies attached hereto that will establish: the engineering design basis for the capture, compression and transportation of CO{sub 2} from the LCC Gasification Project, and the criteria and specifications for a monitoring, verification and accounting (MVA) plan at the Hastings oil field in Texas. The overall objective of Phase 2, provided a successful competitive down-selection, is to execute design, construction and operations of three capital projects: (1) the CO{sub 2} capture and compression equipment, (2) a Connector Pipeline from the LLC Gasification Project to the Green Pipeline owned by Denbury and an affiliate of Denbury, and (3) a comprehensive MVA system at the Hastings oil field.

  8. TU-F-BRF-06: 3D Pancreas MRI Segmentation Using Dictionary Learning and Manifold Clustering

    SciTech Connect

    Gou, S; Rapacchi, S; Hu, P; Sheng, K

    2014-06-15

    Purpose: The recent advent of MRI guided radiotherapy machines has lent an exciting platform for soft tissue target localization during treatment. However, tools to efficiently utilize MRI images for such purpose have not been developed. Specifically, to efficiently quantify the organ motion, we develop an automated segmentation method using dictionary learning and manifold clustering (DLMC). Methods: Fast 3D HASTE and VIBE MR images of 2 healthy volunteers and 3 patients were acquired. A bounding box was defined to include pancreas and surrounding normal organs including the liver, duodenum and stomach. The first slice of the MRI was used for dictionary learning based on mean-shift clustering and K-SVD sparse representation. Subsequent images were iteratively reconstructed until the error is less than a preset threshold. The preliminarily segmentation was subject to the constraints of manifold clustering. The segmentation results were compared with the mean shift merging (MSM), level set (LS) and manual segmentation methods. Results: DLMC resulted in consistently higher accuracy and robustness than comparing methods. Using manual contours as the ground truth, the mean Dices indices for all subjects are 0.54, 0.56 and 0.67 for MSM, LS and DLMC, respectively based on the HASTE image. The mean Dices indices are 0.70, 0.77 and 0.79 for the three methods based on VIBE images. DLMC is clearly more robust on the patients with the diseased pancreas while LS and MSM tend to over-segment the pancreas. DLMC also achieved higher sensitivity (0.80) and specificity (0.99) combining both imaging techniques. LS achieved equivalent sensitivity on VIBE images but was more computationally inefficient. Conclusion: We showed that pancreas and surrounding normal organs can be reliably segmented based on fast MRI using DLMC. This method will facilitate both planning volume definition and imaging guidance during treatment.

  9. Detection and molecular characterization of diarrhea causing viruses in single and mixed infections in children: a comparative study between Bangladesh and Turkey.

    PubMed

    Mitui, Marcelo Takahiro; Bozdayi, Gulendam; Ahmed, Selim; Matsumoto, Takashi; Nishizono, Akira; Ahmed, Kamruddin

    2014-07-01

    The incidence and mortality caused by diarrhea differ among countries. The prevalence of different enteric viruses, their molecular characteristics, and infections with multiple viruses might affect the disease incidence and mortality caused by diarrhea. The objective of this study was to determine the distribution and molecular characteristics of enteric viruses in children with diarrhea in Turkey and Bangladesh. A total of 288 stool samples that were negative for group A rotavirus were collected from children aged <5 years with acute diarrhea who presented to hospitals in Turkey and Bangladesh. The samples were screened for human bocavirus (HBoV), astrovirus (HAstV), norovirus (NoV), and adenovirus (AdV). Phylogenetic analyses of the targeted virus genes were performed. In Turkey, viruses were detected in 87/150 samples (58%), which included 69 (79.3%) with single viruses and 18 (20.7%) with multiple viruses. AdV was the most common virus, followed by HBoV. In Bangladesh, viruses were detected in 123/138 samples (89.1%), which included 29 (23.6%) with single viruses and 94 (76.4%) with multiple viruses. NoV GII was the most common, followed by AdV. The dominant genotypes among the virus species were HBoV 2A, HAstV 1, NoV GI type 1, and AdV 40. For NoV GII, the Hunter variant of genotype 4 in Turkey and genotype 17 in Bangladesh were the most common among the sequenced strains. It was concluded that the distribution of the viruses associated with diarrhea in Turkish and Bangladeshi children was different. Enteric viruses and mixed infections were more prevalent in Bangladesh than in Turkey.

  10. Base excess or buffer base (strong ion difference) as measure of a non-respiratory acid-base disturbance.

    PubMed

    Siggaard-Andersen, O; Fogh-Andersen, N

    1995-01-01

    Stewart in 1983 (Can J Physiol Pharmacol 1983: 61: 1444) reintroduced plasma buffer base under the name "strong ion difference" (SID). Buffer base was originally introduced by Singer and Hastings in 1948 (Medicine (Baltimore) 1948: 27: 223). Plasma buffer base, which is practically equal to the sum of bicarbonate and albuminate anions, may be increased due to an excess of base or due to an increased albumin concentration. Singer and Hastings did not consider changes in albumin as acid-base disorders and therefore used the base excess, i.e., the actual buffer base minus the buffer base at normal pH and pCO2, as measure of a non-respiratory acid-base disturbance. Stewart and followers, however, consider changes in albumin concentration to be acid-base disturbances: a patient with normal pH, pCO2, and base excess but with increased plasma buffer base due to increased plasma albumin concentration get the diagnoses metabolic (strong ion) alkalosis (because plasma buffer base is increased) combined with metabolic hyperalbuminaemic acidosis. Extrapolating to whole blood, anaemia and polycytaemia should represent types of metabolic alkalosis and acidosis, respectively. This reveals that the Stewart approach is absurd and anachronistic in the sense that an increase or decrease in any anion is interpreted as indicating an excess or deficit of a specific acid. In other words, a return to the archaic definitions of acids and bases as being the same as anions and cations. We conclude that the acid-base status (the hydrogen ion status) of blood and extracellular fluid is described in terms of the arterial pH, the arterial pCO2, and the extracellular base excess. It is measured with a modern pH-blood gas analyser. The electrolyte status of the plasma is a description of the most important electrolytes, usually measured in venous blood with a dedicated electrolyte analyser, i.e., Na+, Cl-, HCO3-, and K+. Albumin anions contribute significantly to the anions, but calculation

  11. Fetal Central Nervous System Anomalies Detected by Magnetic Resonance Imaging: A Two-Year Experience

    PubMed Central

    Sefidbakht, Sepideh; Dehghani, Sakineh; Safari, Maryam; Vafaei, Homeira; Kasraeian, Maryam

    2016-01-01

    Background Magnetic resonance imaging (MRI) is gradually becoming more common for thorough visualization of the fetus than ultrasound (US), especially for neurological anomalies, which are the most common indications for fetal MRI and are a matter of concern for both families and society. Objectives We investigated fetal MRIs carried out in our center for frequency of central nervous system anomalies. This is the first such report in southern Iran. Materials and Methods One hundred and seven (107) pregnant women with suspicious fetal anomalies in prenatal ultrasound entered a cross-sectional retrospective study from 2011 to 2013. A 1.5 T Siemens Avanto scanner was employed for sequences, including T2 HASTE and Trufisp images in axial, coronal, and sagittal planes to mother’s body, T2 HASTE and Trufisp relative to the specific fetal body part being evaluated, and T1 flash images in at least one plane based on clinical indication. We investigated any abnormality in the central nervous system and performed descriptive analysis to achieve index of frequency. Results Mean gestational age ± standard deviation (SD) for fetuses was 25.54 ± 5.22 weeks, and mean maternal age ± SD was 28.38 ± 5.80 years Eighty out of 107 (74.7%) patients who were referred with initial impression of borderline ventriculomegaly. A total of 18 out of 107 (16.82%) patients were found to have fetuses with CNS anomalies and the remainder were neurologically normal. Detected anomalies were as follow: 3 (16.6%) fetuses each had the Dandy-Walker variant and Arnold-Chiari II (with myelomeningocele). Complete agenesis of corpus callosum, partial agenesis of corpus callosum, and aqueductal stenosis were each seen in 2 (11.1%) fetuses. Arnold-Chiari II without myelomeningocele, anterior spina bifida associated with neurenteric cyst, arachnoid cyst, lissencephaly, and isolated enlarged cisterna magna each presented in one (5.5%) fetus. One fetus had concomitant schizencephaly and complete agenesis of

  12. Exotic ingredients in the mélange at Port Macquarie, southern New England Orogen, reveal a spicy history of crustal kneading along eastern Gondwana

    NASA Astrophysics Data System (ADS)

    Buckman, S.; Nutman, A.

    2013-12-01

    (sinistral) displacement of the Port Macquarie and Hastings Blocks and the dextral displacement of the Coffs Harbour Block associated with the Texas orocline, is apparent only, and due more in part to vertical displacements of an extensive, thin-skinned oceanic terranes that underlie the Tablelands Complex, rather than extensive lateral movements. Thus, there is no need to invoke large-scale ';oroclinal' folding or significant sinistral faulting to explain the repetition of Hastings and Port Macquarie blocks in the southern New England.

  13. A simulation approach for change-points on phylogenetic trees.

    PubMed

    Persing, Adam; Jasra, Ajay; Beskos, Alexandros; Balding, David; De Iorio, Maria

    2015-01-01

    We observe n sequences at each of m sites and assume that they have evolved from an ancestral sequence that forms the root of a binary tree of known topology and branch lengths, but the sequence states at internal nodes are unknown. The topology of the tree and branch lengths are the same for all sites, but the parameters of the evolutionary model can vary over sites. We assume a piecewise constant model for these parameters, with an unknown number of change-points and hence a transdimensional parameter space over which we seek to perform Bayesian inference. We propose two novel ideas to deal with the computational challenges of such inference. Firstly, we approximate the model based on the time machine principle: the top nodes of the binary tree (near the root) are replaced by an approximation of the true distribution; as more nodes are removed from the top of the tree, the cost of computing the likelihood is reduced linearly in n. The approach introduces a bias, which we investigate empirically. Secondly, we develop a particle marginal Metropolis-Hastings (PMMH) algorithm, that employs a sequential Monte Carlo (SMC) sampler and can use the first idea. Our time-machine PMMH algorithm copes well with one of the bottle-necks of standard computational algorithms: the transdimensional nature of the posterior distribution. The algorithm is implemented on simulated and real data examples, and we empirically demonstrate its potential to outperform competing methods based on approximate Bayesian computation (ABC) techniques. PMID:25506749

  14. Exploring equivalence domain in nonlinear inverse problems using Covariance Matrix Adaption Evolution Strategy (CMAES) and random sampling

    NASA Astrophysics Data System (ADS)

    Grayver, Alexander V.; Kuvshinov, Alexey V.

    2016-05-01

    This paper presents a methodology to sample equivalence domain (ED) in nonlinear partial differential equation (PDE)-constrained inverse problems. For this purpose, we first applied state-of-the-art stochastic optimization algorithm called Covariance Matrix Adaptation Evolution Strategy (CMAES) to identify low-misfit regions of the model space. These regions were then randomly sampled to create an ensemble of equivalent models and quantify uncertainty. CMAES is aimed at exploring model space globally and is robust on very ill-conditioned problems. We show that the number of iterations required to converge grows at a moderate rate with respect to number of unknowns and the algorithm is embarrassingly parallel. We formulated the problem by using the generalized Gaussian distribution. This enabled us to seamlessly use arbitrary norms for residual and regularization terms. We show that various regularization norms facilitate studying different classes of equivalent solutions. We further show how performance of the standard Metropolis-Hastings Markov chain Monte Carlo algorithm can be substantially improved by using information CMAES provides. This methodology was tested by using individual and joint inversions of magneotelluric, controlled-source electromagnetic (EM) and global EM induction data.

  15. Investigation of - and Post-Seismic Signals in GRACE Satellite Gravity Data Using Mcmc Approach

    NASA Astrophysics Data System (ADS)

    Mikhailov, V. O.; Hayn, M.; Pollitz, F. F.; Panet, I.; Holschneider, M.; Diament, M.

    2013-12-01

    Earthquakes cause mass shifts and stress-dependent density changes. The corresponding gravity field variations can be measured by the GRACE satellites what was demonstrated for recent Andaman-Sumatra (2004), Maule, Chili (2010) and Tohoku-Oki (2011) earthquakes. In contrast to other data, satellite gravity regularly covers continental and oceanic areas, providing important information about the seismic cycle, especially in subduction zones. We make use of the characteristic temporal behavior and spatial scale of the earthquake signals, in order to separate them from other contributions to the gravity field. This is realized by wavelet transform and application of a time evolution model. The later consists of a step function followed by an exponential decay, representing co- and post-seismic variations. As the problem is nonlinear, parameters were fitted by determining their posterior distribution by means of a Markov-Chain Metropolis-Hasting sampling. As a result, we clearly separate the co- and post-seismic gravity variations for all three abovementioned earthquakes. We also apply the method to separate post-seismic signals from the Andaman-Sumatra and Nias-Sumatra events. The later occurred 3 months later to the south of the main megathrust event. These results are compared with other geophysical data and models. This allows to discriminate between candidate models for the co-seismic gravity variations using GPS data and seismology, and to better understand the physical processes involved in the post-seismic deformation.

  16. HZAR: hybrid zone analysis using an R software package.

    PubMed

    Derryberry, Elizabeth P; Derryberry, Graham E; Maley, James M; Brumfield, Robb T

    2014-05-01

    We present a new software package (HZAR) that provides functions for fitting molecular genetic and morphological data from hybrid zones to classic equilibrium cline models using the Metropolis-Hastings Markov chain Monte Carlo (MCMC) algorithm. The software applies likelihood functions appropriate for different types of data, including diploid and haploid genetic markers and quantitative morphological traits. The modular design allows flexibility in fitting cline models of varying complexity. To facilitate hypothesis testing, an autofit function is included that allows automated model selection from a set of nested cline models. Cline parameter values, such as cline centre and cline width, are estimated and may be compared statistically across clines. The package is written in the R language and is available through the Comprehensive R Archive Network (CRAN; http://cran.r-project.org/). Here, we describe HZAR and demonstrate its use with a sample data set from a well-studied hybrid zone in western Panama between white-collared (Manacus candei) and golden-collared manakins (M. vitellinus). Comparisons of our results with previously published results for this hybrid zone validate the hzar software. We extend analysis of this hybrid zone by fitting additional models to molecular data where appropriate.

  17. A MARKOV CHAIN MONTE CARLO ALGORITHM FOR ANALYSIS OF LOW SIGNAL-TO-NOISE COSMIC MICROWAVE BACKGROUND DATA

    SciTech Connect

    Jewell, J. B.; O'Dwyer, I. J.; Huey, Greg; Gorski, K. M.; Eriksen, H. K.; Wandelt, B. D. E-mail: h.k.k.eriksen@astro.uio.no

    2009-05-20

    We present a new Markov Chain Monte Carlo (MCMC) algorithm for cosmic microwave background (CMB) analysis in the low signal-to-noise regime. This method builds on and complements the previously described CMB Gibbs sampler, and effectively solves the low signal-to-noise inefficiency problem of the direct Gibbs sampler. The new algorithm is a simple Metropolis-Hastings sampler with a general proposal rule for the power spectrum, C {sub l}, followed by a particular deterministic rescaling operation of the sky signal, s. The acceptance probability for this joint move depends on the sky map only through the difference of {chi}{sup 2} between the original and proposed sky sample, which is close to unity in the low signal-to-noise regime. The algorithm is completed by alternating this move with a standard Gibbs move. Together, these two proposals constitute a computationally efficient algorithm for mapping out the full joint CMB posterior, both in the high and low signal-to-noise regimes.

  18. Telos versus Praxis in Bioethics.

    PubMed

    Chambers, Tod S

    2016-09-01

    The authors of "A Conceptual Model for the Translation of Bioethics Research and Scholarship" argue that bioethics must respond to institutional pressures by demonstrating that it is having an impact in the world. Any impact, the authors observe, must be "informed" by the goals of the discipline of bioethics. The concept of bioethics as a discipline is central to their argument. They begin by citing an essay that Daniel Callahan wrote in the first issue of Hastings Center Studies. Callahan argued in this 1973 piece that bioethics had yet to attain the status of a discipline, and he lauded the freedom of being able to define a new discipline. Callahan's essay shares with Mathews and colleague's a peculiarity: neither ever defines what it means to refer to something as a "discipline." To define a discipline does mean attending to the intended end product of scholarly activity, so I concur with Mathews et al.'s focus on outcomes. But I am concerned that in their argument they confusingly entangle their understanding of an academic discipline's internal goals, its telos, with its potential to have an impact on the external world, its praxis. The confusion that this can bring exposes what I believe is a profound problem within bioethics, the discipline's peculiar and at times intellectually hazardous relationship with its institutional hosts.

  19. Chemical analyses of surface waters in Oklahoma, September - December, 1944

    USGS Publications Warehouse

    U.S. Geological Survey

    1945-01-01

    Red River at Denison Dam, Texas Sport samples were collected at the remainder of the stations. The analyses of the spot samples were made largely in a laboratory provided by the Oklahoma A. & M. College, under the supervision of Dr. O.M. Smith, Head, Department of Chemistry; Dr. S.R. Wood, Associate Professor of Chemistry; and W.W. Hastings, U.S. Geological Survey. The daily samples were analyzed in the water resources laboratory of the Geological Survey at Austin, Texas. These data have been summarized in a report to the Oklahoma Planning and Resources Board prepared by the U.S. Geological Survey, March 1, 1945. The streams of Oklahoma are classified into two major drainage basins: the Arkansas River and the Red River and their tributaries. The attached analyses are arranged in geographical order for their respective drainage basins, with records listed in downstream order for stations on the main stem first, followed by the analyses for the tributaries. When available, the mean daily discharge is given for the analyses.

  20. Bayesian Statistical Approach To Binary Asteroid Orbit Determination

    NASA Astrophysics Data System (ADS)

    Dmitrievna Kovalenko, Irina; Stoica, Radu S.

    2015-08-01

    Orbit determination from observations is one of the classical problems in celestial mechanics. Deriving the trajectory of binary asteroid with high precision is much more complicate than the trajectory of simple asteroid. Here we present a method of orbit determination based on the algorithm of Monte Carlo Markov Chain (MCMC). This method can be used for the preliminary orbit determination with relatively small number of observations, or for adjustment of orbit previously determined.The problem consists on determination of a conditional a posteriori probability density with given observations. Applying the Bayesian statistics, the a posteriori probability density of the binary asteroid orbital parameters is proportional to the a priori and likelihood probability densities. The likelihood function is related to the noise probability density and can be calculated from O-C deviations (Observed minus Calculated positions). The optionally used a priori probability density takes into account information about the population of discovered asteroids. The a priori probability density is used to constrain the phase space of possible orbits.As a MCMC method the Metropolis-Hastings algorithm has been applied, adding a globally convergent coefficient. The sequence of possible orbits derives through the sampling of each orbital parameter and acceptance criteria.The method allows to determine the phase space of every possible orbit considering each parameter. It also can be used to derive one orbit with the biggest probability density of orbital elements.

  1. HZAR: hybrid zone analysis using an R software package.

    PubMed

    Derryberry, Elizabeth P; Derryberry, Graham E; Maley, James M; Brumfield, Robb T

    2014-05-01

    We present a new software package (HZAR) that provides functions for fitting molecular genetic and morphological data from hybrid zones to classic equilibrium cline models using the Metropolis-Hastings Markov chain Monte Carlo (MCMC) algorithm. The software applies likelihood functions appropriate for different types of data, including diploid and haploid genetic markers and quantitative morphological traits. The modular design allows flexibility in fitting cline models of varying complexity. To facilitate hypothesis testing, an autofit function is included that allows automated model selection from a set of nested cline models. Cline parameter values, such as cline centre and cline width, are estimated and may be compared statistically across clines. The package is written in the R language and is available through the Comprehensive R Archive Network (CRAN; http://cran.r-project.org/). Here, we describe HZAR and demonstrate its use with a sample data set from a well-studied hybrid zone in western Panama between white-collared (Manacus candei) and golden-collared manakins (M. vitellinus). Comparisons of our results with previously published results for this hybrid zone validate the hzar software. We extend analysis of this hybrid zone by fitting additional models to molecular data where appropriate. PMID:24373504

  2. Deep soil carbon dynamics are driven more by soil type than by climate: a worldwide meta-analysis of radiocarbon profiles.

    PubMed

    Mathieu, Jordane A; Hatté, Christine; Balesdent, Jérôme; Parent, Éric

    2015-11-01

    The response of soil carbon dynamics to climate and land-use change will affect both the future climate and the quality of ecosystems. Deep soil carbon (>20 cm) is the primary component of the soil carbon pool, but the dynamics of deep soil carbon remain poorly understood. Therefore, radiocarbon activity (Δ14C), which is a function of the age of carbon, may help to understand the rates of soil carbon biodegradation and stabilization. We analyzed the published 14C contents in 122 profiles of mineral soil that were well distributed in most of the large world biomes, except for the boreal zone. With a multivariate extension of a linear mixed-effects model whose inference was based on the parallel combination of two algorithms, the expectation-maximization (EM) and the Metropolis-Hasting algorithms, we expressed soil Δ14C profiles as a four-parameter function of depth. The four-parameter model produced insightful predictions of soil Δ14C as dependent on depth, soil type, climate, vegetation, land-use and date of sampling (R2=0.68). Further analysis with the model showed that the age of topsoil carbon was primarily affected by climate and cultivation. By contrast, the age of deep soil carbon was affected more by soil taxa than by climate and thus illustrated the strong dependence of soil carbon dynamics on other pedologic traits such as clay content and mineralogy.

  3. The Origin of Spontaneous Mutation in SACCHAROMYCES CEREVISIAE

    PubMed Central

    Quah, Siew-Keen; von Borstel, R. C.; Hastings, P. J.

    1980-01-01

    Characterization of two antimutator loci in yeast shows that both are members of the same mutagenic repair system known to be responsible for almost all induced mutation (Lawrence and Christensen 1976, 1979a,b; Prakash 1976). One of the these newly isolated antimutator mutations is an allele of rev3 (Lemontt 1971b). Two other alleles of rev3 were tested and were also found to be antimutators. Double mutants carrying rev3 and mutator mutations of rad3, rad51 or rad18 are like rev3 single mutants with respect to spontaneous mutation rate, supporting the hypothesis (Hastings, Quah and von Borstel 1976) that many mutators in yeast act by channelling spontaneous lesions from accurate to mutagenic repair. However, the enhanced mutation rate seen in a radiation-resistant mutator mutant mut1 is not dependent on REV3, but is dependent on another gene designated ANT1. An additive effect on the reduction in spontaneous mutation, seen in the ant1 rev3 double-mutant strain, leads to the conclusion that at least 90% of spontaneous mutations seen in the wild type are caused by mutagenic repair of spontaneous lesions. PMID:7021317

  4. Using intraoperative MRI to assess bleeding

    NASA Astrophysics Data System (ADS)

    Liu, Haiying; Hall, Walter A.; Martin, Alastair J.; Truwit, Charles L.

    2001-05-01

    Immediate detector of any surgically induced hemorrhage prior to the closure is important for minimizing the unnecessary post surgical complications. In the case of hemorrhage, the surgical site of interests often involves hemorrhagic blood in the presence of CSF as well as air pockets. It is known that the hemorrhagic blood or air has a different magnetic susceptibility from its surrounding tissue, and CSF has long T1 and T2. Based on these differences, a set of complimentary imaging techniques (T2, FLAIR, and GE) were optimized to reveal the existence of surgically induced acute hemorrhage. Among 330 neurosurgical cases, one relatively severe hemorrhage has been successfully found intra-operatively using the concept. During the case, a new hyperintense area close to the primary motor cortex was initially noticed on T2 weighted HASTE images. As soon as it was found to increase in size rapidly, the patient was treated immediately via craniotomy for aspiration of the intra-parenchymal blood. Owing to early detection and treatment, the patient was completely free of motor deficits. Besides, there were ten much less severe hemorrhages have been noticed using the method. The proper post-surgical care was planned to closely follow-up the patient for any sign of hemorrhage.

  5. Virtual goods recommendations in virtual worlds.

    PubMed

    Chen, Kuan-Yu; Liao, Hsiu-Yu; Chen, Jyun-Hung; Liu, Duen-Ren

    2015-01-01

    Virtual worlds (VWs) are computer-simulated environments which allow users to create their own virtual character as an avatar. With the rapidly growing user volume in VWs, platform providers launch virtual goods in haste and stampede users to increase sales revenue. However, the rapidity of development incurs virtual unrelated items which will be difficult to remarket. It not only wastes virtual global companies' intelligence resources, but also makes it difficult for users to find suitable virtual goods fit for their virtual home in daily virtual life. In the VWs, users decorate their houses, visit others' homes, create families, host parties, and so forth. Users establish their social life circles through these activities. This research proposes a novel virtual goods recommendation method based on these social interactions. The contact strength and contact influence result from interactions with social neighbors and influence users' buying intention. Our research highlights the importance of social interactions in virtual goods recommendation. The experiment's data were retrieved from an online VW platform, and the results show that the proposed method, considering social interactions and social life circle, has better performance than existing recommendation methods. PMID:25834837

  6. On the construction and analysis of stochastic models: Characterization and propagation of the errors associated with limited data

    SciTech Connect

    Ghanem, Roger G. . E-mail: ghanem@usc.edu; Doostan, Alireza . E-mail: doostan@jhu.edu

    2006-09-01

    This paper investigates the predictive accuracy of stochastic models. In particular, a formulation is presented for the impact of data limitations associated with the calibration of parameters for these models, on their overall predictive accuracy. In the course of this development, a new method for the characterization of stochastic processes from corresponding experimental observations is obtained. Specifically, polynomial chaos representations of these processes are estimated that are consistent, in some useful sense, with the data. The estimated polynomial chaos coefficients are themselves characterized as random variables with known probability density function, thus permitting the analysis of the dependence of their values on further experimental evidence. Moreover, the error in these coefficients, associated with limited data, is propagated through a physical system characterized by a stochastic partial differential equation (SPDE). This formalism permits the rational allocation of resources in view of studying the possibility of validating a particular predictive model. A Bayesian inference scheme is relied upon as the logic for parameter estimation, with its computational engine provided by a Metropolis-Hastings Markov chain Monte Carlo procedure.

  7. A coupled hidden Markov model for disease interactions.

    PubMed

    Sherlock, Chris; Xifara, Tatiana; Telfer, Sandra; Begon, Mike

    2013-08-01

    To investigate interactions between parasite species in a host, a population of field voles was studied longitudinally, with presence or absence of six different parasites measured repeatedly. Although trapping sessions were regular, a different set of voles was caught at each session, leading to incomplete profiles for all subjects. We use a discrete time hidden Markov model for each disease with transition probabilities dependent on covariates via a set of logistic regressions. For each disease the hidden states for each of the other diseases at a given time point form part of the covariate set for the Markov transition probabilities from that time point. This allows us to gauge the influence of each parasite species on the transition probabilities for each of the other parasite species. Inference is performed via a Gibbs sampler, which cycles through each of the diseases, first using an adaptive Metropolis-Hastings step to sample from the conditional posterior of the covariate parameters for that particular disease given the hidden states for all other diseases and then sampling from the hidden states for that disease given the parameters. We find evidence for interactions between several pairs of parasites and of an acquired immune response for two of the parasites. PMID:24223436

  8. A multi-thermogram-based Bayesian model for the determination of the thermal diffusivity of a material

    NASA Astrophysics Data System (ADS)

    Allard, Alexandre; Fischer, Nicolas; Ebrard, Géraldine; Hay, Bruno; Harris, Peter; Wright, Louise; Rochais, Denis; Mattout, Jeremie

    2016-02-01

    The determination of thermal diffusivity is at the heart of modern materials characterisation. The evaluation of the associated uncertainty is difficult because the determination is performed in an indirect way, in the sense that the thermal diffusivity cannot be measured directly. The well-known GUM uncertainty framework does not provide a reliable evaluation of measurement uncertainty for such inverse problems, because in that framework the underlying measurement model is supposed to be a direct relationship between the measurand (the quantity intended to be measured) and the input quantities on which the measurand depends. This paper is concerned with the development of a Bayesian approach to evaluate the measurement uncertainty associated with thermal diffusivity. A Bayesian model is first developed for a single thermogram and is then extended to the case of several thermograms obtained under repeatability and reproducibility conditions. This multi-thermogram based model is able to take into consideration a large set of influencing quantities that occur during the measurements and yields a more reliable uncertainty evaluation than the one obtained from a single thermogram. Different aspects of the Bayesian model are discussed, including the sensitivity to the choice of the prior distribution, the Metropolis-Hastings algorithm used for the inference and the convergence of the Markov chains.

  9. Estimation of seabed shear-wave velocity profiles using shear-wave source data.

    PubMed

    Dong, Hefeng; Nguyen, Thanh-Duong; Duffaut, Kenneth

    2013-07-01

    This paper estimates seabed shear-wave velocity profiles and their uncertainties using interface-wave dispersion curves extracted from data generated by a shear-wave source. The shear-wave source generated a seismic signature over a frequency range between 2 and 60 Hz and was polarized in both in-line and cross-line orientations. Low-frequency Scholte- and Love-waves were recorded. Dispersion curves of the Scholte- and Love-waves for the fundamental mode and higher-order modes are extracted by three time-frequency analysis methods. Both the vertically and horizontally polarized shear-wave velocity profiles in the sediment are estimated by the Scholte- and Love-wave dispersion curves, respectively. A Bayesian approach is utilized for the inversion. Differential evolution, a global search algorithm is applied to estimate the most-probable shear-velocity models. Marginal posterior probability profiles are computed by Metropolis-Hastings sampling. The estimated vertically and horizontally polarized shear-wave velocity profiles fit well with the core and in situ measurements. PMID:23862796

  10. Emergency medical services public health implications and interim guidance for the Ebola virus in the United States.

    PubMed

    McCoy, Christopher E; Lotfipour, Shahram; Chakravarthy, Bharath; Schultz, Carl; Barton, Erik

    2014-11-01

    The 25th known outbreak of the Ebola Virus Disease (EVD) is now a global public health emergency and the World Health Organization (WHO) has declared the epidemic to be a Public Health Emergency of International Concern (PHEIC). Since the first cases of the West African epidemic were reported in March 2014, there has been an increase in infection rates of over 13,000% over a 6-month period. The Ebola virus has now arrived in the United States and public health professionals, doctors, hospitals, Emergency Medial Services Administrators, Medical Directors, and policy makers have been working with haste to develop strategies to prevent the disease from reaching epidemic proportions. Prehospital care providers (emergency medical technicians and paramedics) and medical first responders (including but not limited to firefighters and law enforcement) are the healthcare systems front lines when it comes to first medical contact with patients outside of the hospital setting. Risk of contracting Ebola can be particularly high in this population of first responders if the appropriate precautions are not implemented. This article provides a brief clinical overview of the Ebola Virus Disease and provides a comprehensive summary of the Center for Disease Control and Prevention's Interim Guidance for Emergency Medical Services (EMS) Systems and 9-1-1 Public Safety Answering Points (PSAPS) for Management of Patients with Known of Suspected Ebola Virus Disease in the United States.

  11. Modeling and simulation of cascading contingencies

    NASA Astrophysics Data System (ADS)

    Zhang, Jianfeng

    This dissertation proposes a new approach to model and study cascading contingencies in large power systems. The most important contribution of the work involves the development and validation of a heuristic analytic model to assess the likelihood of cascading contingencies, and the development and validation of a uniform search strategy. We model the probability of cascading contingencies as a function of power flow and power flow changes. Utilizing logistic regression, the proposed model is calibrated using real industry data. This dissertation analyzes random search strategies for Monte Carlo simulations and proposes a new uniform search strategy based on the Metropolis-Hastings Algorithm. The proposed search strategy is capable of selecting the most significant cascading contingencies, and it is capable of constructing an unbiased estimator to provide a measure of system security. This dissertation makes it possible to reasonably quantify system security and justify security operations when economic concerns conflict with reliability concerns in the new competitive power market environment. It can also provide guidance to system operators about actions that may be taken to reduce the risk of major system blackouts. Various applications can be developed to take advantage of the quantitative security measures provided in this dissertation.

  12. An attraction-repulsion point process model for respiratory syncytial virus infections.

    PubMed

    Goldstein, Joshua; Haran, Murali; Simeonov, Ivan; Fricks, John; Chiaromonte, Francesca

    2015-06-01

    How is the progression of a virus influenced by properties intrinsic to individual cells? We address this question by studying the susceptibility of cells infected with two strains of the human respiratory syncytial virus (RSV-A and RSV-B) in an in vitro experiment. Spatial patterns of infected cells give us insight into how local conditions influence susceptibility to the virus. We observe a complicated attraction and repulsion behavior, a tendency for infected cells to lump together or remain apart. We develop a new spatial point process model to describe this behavior. Inference on spatial point processes is difficult because the likelihood functions of these models contain intractable normalizing constants; we adapt an MCMC algorithm called double Metropolis-Hastings to overcome this computational challenge. Our methods are computationally efficient even for large point patterns consisting of over 10,000 points. We illustrate the application of our model and inferential approach to simulated data examples and fit our model to various RSV experiments. Because our model parameters are easy to interpret, we are able to draw meaningful scientific conclusions from the fitted models. PMID:25660222

  13. T2-weighted balanced SSFP imaging (T2-TIDE) using variable flip angles.

    PubMed

    Paul, Dominik; Markl, Michael; Fautz, Hans-Peter; Hennig, Jürgen

    2006-07-01

    A new technique for acquiring T2-weighted, balanced steady-state free precession (b-SSFP) images is presented. Based on the recently proposed transition into driven equilibrium (TIDE) method, T2-TIDE uses a special flip angle scheme to achieve T2-weighted signal decay during the transient phase. In combination with half-Fourier image acquisition, T2-weighted images can be obtained using T2-TIDE. Numerical simulations were performed to analyze the signal behavior of T2-TIDE in comparison with TSE and b-SSFP. The results indicate identical signal evolution of T2-TIDE and TSE during the transient phase. T2-TIDE was used in phantom experiments, and quantitative ROI analysis shows a linear relationship between TSE and T2-TIDE SNR values. T2-TIDE was also applied to abdominal and head imaging on healthy volunteers. The resulting images were analyzed quantitatively and compared with standard T2-weighted and standard b-SSFP methods. T2-TIDE images clearly revealed T2 contrast and less blurring compared to T2-HASTE images. In combination with a magnetization preparation technique, STIR-weighted images were obtained. T2-TIDE is a robust technique for acquiring T2-weighted images while exploiting the advantages of b-SSFP imaging, such as high signal-to-noise ratio (SNR) and short TRs.

  14. Virtual goods recommendations in virtual worlds.

    PubMed

    Chen, Kuan-Yu; Liao, Hsiu-Yu; Chen, Jyun-Hung; Liu, Duen-Ren

    2015-01-01

    Virtual worlds (VWs) are computer-simulated environments which allow users to create their own virtual character as an avatar. With the rapidly growing user volume in VWs, platform providers launch virtual goods in haste and stampede users to increase sales revenue. However, the rapidity of development incurs virtual unrelated items which will be difficult to remarket. It not only wastes virtual global companies' intelligence resources, but also makes it difficult for users to find suitable virtual goods fit for their virtual home in daily virtual life. In the VWs, users decorate their houses, visit others' homes, create families, host parties, and so forth. Users establish their social life circles through these activities. This research proposes a novel virtual goods recommendation method based on these social interactions. The contact strength and contact influence result from interactions with social neighbors and influence users' buying intention. Our research highlights the importance of social interactions in virtual goods recommendation. The experiment's data were retrieved from an online VW platform, and the results show that the proposed method, considering social interactions and social life circle, has better performance than existing recommendation methods.

  15. Analysis of human mini-exome sequencing data from Genetic Analysis Workshop 17 using a Bayesian hierarchical mixture model

    PubMed Central

    2011-01-01

    Next-generation sequencing technologies are rapidly changing the field of genetic epidemiology and enabling exploration of the full allele frequency spectrum underlying complex diseases. Although sequencing technologies have shifted our focus toward rare genetic variants, statistical methods traditionally used in genetic association studies are inadequate for estimating effects of low minor allele frequency variants. Four our study we use the Genetic Analysis Workshop 17 data from 697 unrelated individuals (genotypes for 24,487 autosomal variants from 3,205 genes). We apply a Bayesian hierarchical mixture model to identify genes associated with a simulated binary phenotype using a transformed genotype design matrix weighted by allele frequencies. A Metropolis Hasting algorithm is used to jointly sample each indicator variable and additive genetic effect pair from its conditional posterior distribution, and remaining parameters are sampled by Gibbs sampling. This method identified 58 genes with a posterior probability greater than 0.8 for being associated with the phenotype. One of these 58 genes, PIK3C2B was correctly identified as being associated with affected status based on the simulation process. This project demonstrates the utility of Bayesian hierarchical mixture models using a transformed genotype matrix to detect genes containing rare and common variants associated with a binary phenotype. PMID:22373180

  16. An Empirical Prior Improves Accuracy for Bayesian Estimation of Transcription Factor Binding Site Frequencies within Gene Promoters

    PubMed Central

    Ramsey, Stephen A.

    2015-01-01

    A Bayesian method for sampling from the distribution of matches to a precompiled transcription factor binding site (TFBS) sequence pattern (conditioned on an observed nucleotide sequence and the sequence pattern) is described. The method takes a position frequency matrix as input for a set of representative binding sites for a transcription factor and two sets of noncoding, 5′ regulatory sequences for gene sets that are to be compared. An empirical prior on the frequency A (per base pair of gene-vicinal, noncoding DNA) of TFBSs is developed using data from the ENCODE project and incorporated into the method. In addition, a probabilistic model for binding site occurrences conditioned on λ is developed analytically, taking into account the finite-width effects of binding sites. The count of TFBS β (conditioned on the observed sequence) is sampled using Metropolis–Hastings with an information entropy-based move generator. The derivation of the method is presented in a step-by-step fashion, starting from specific conditional independence assumptions. Empirical results show that the newly proposed prior on β improves accuracy for estimating the number of TFBS within a set of promoter sequences. PMID:27812284

  17. Empirical study of the GARCH model with rational errors

    NASA Astrophysics Data System (ADS)

    Chen, Ting Ting; Takaishi, Tetsuya

    2013-08-01

    We use the GARCH model with a fat-tailed error distribution described by a rational function and apply it to stock price data on the Tokyo Stock Exchange. To determine the model parameters we perform Bayesian inference to the model. Bayesian inference is implemented by the Metropolis-Hastings algorithm with an adaptive multi-dimensional Student's t-proposal density. In order to compare our model with the GARCH model with the standard normal errors, we calculate the information criteria AIC and DIC, and find that both criteria favor the GARCH model with a rational error distribution. We also calculate the accuracy of the volatility by using the realized volatility and find that a good accuracy is obtained for the GARCH model with a rational error distribution. Thus we conclude that the GARCH model with a rational error distribution is superior to the GARCH model with the normal errors and it can be used as an alternative GARCH model to those with other fat-tailed distributions.

  18. A high reliability module with thermoelectric device by molding technology for M2M wireless sensor network

    NASA Astrophysics Data System (ADS)

    Nakagawa, K.; Tanaka, T.; Suzuki, T.

    2015-10-01

    This paper presents the fabrication of a new energy harvesting module that uses a thermoelectric device (TED) by using molding technology. Through molding technology, the TED and circuit board can be properly protected and a heat-radiating fin structure can be simultaneously constructed. The output voltage per heater temperature of the TED module at 20 °C ambient temperature is 8 mV K-1, similar to the result with the aluminum heat sink which is almost the same fin size as the TED module. The accelerated environmental tests are performed on a damp heat test, which is an aging test under high temperature and high humidity, highly accelerated temperature, and humidity stress test (HAST) for the purpose of evaluating the electrical reliability in harsh environments, cold test and thermal cycle test to evaluate degrading characteristics by cycling through two temperatures. All test results indicate that the TED and circuit board can be properly protected from harsh temperature and humidity by using molding technology because the output voltage of after-tested modules is reduced by less than 5%. This study presents a novel fabrication method for a high reliability TED-installed module appropriate for Machine to Machine wireless sensor networks.

  19. A high Reliability Module with Thermoelectric Device by Molding Technology for M2M Wireless Sensor Network

    NASA Astrophysics Data System (ADS)

    Nakagawa, K.; Tanaka, T.; Suzuki, T.

    2014-11-01

    This paper presents the fabrication of a new energy harvesting module that used the thermoelectric device (TED) by using molding technology. The output voltage per heater temperature of the TED module at 20 °C ambient temperature is 8mV/K and similar to the result with the aluminium heat sink which is almost the same fin size as the TED module. The accelerated environmental tests are performed on damp heat test that is an aging test under high temperature and high humidity, cold test and highly accelerated temperature and humidity stress test (HAST) for the purpose of evaluating the electrical reliability in harsh environments. Every result of tests indicates that the TED and circuit board can be properly protected from harsh temperature and humidity by using molding technology, because the output voltage of after tested modules is reduced by less than 5%.This study presents a novel fabrication method for a high reliability TED-installed module appropriate for Machine to Machine wireless sensor networks

  20. Molecular basis for the blue bioluminescence of the Australian glow-worm Arachnocampa richardsae (Diptera: Keroplatidae).

    PubMed

    Trowell, Stephen C; Dacres, Helen; Dumancic, Mira M; Leitch, Virginia; Rickards, Rodney W

    2016-09-16

    Bioluminescence is the emission of visible light by living organisms. Here we describe the isolation and characterisation of a cDNA encoding a MW ≈ 59,000 Da luciferase from the Australian glow-worm, Arachnocampa richardsae. The enzyme is a member of the acyl-CoA ligase superfamily and produces blue light on addition of D-luciferin. These results are contrary to earlier reports (Lee, J., Photochem Photobiol 24, 279-285 (1976), Viviani, V. R., Hastings, J. W. & Wilson, T., Photochem Photobiol 75, 22-27 (2002)), which suggested glow-worm luciferase has MW ≈ 36,000 Da and is unreactive with beetle luciferin. There are more than 2000 species of firefly, which all produce emissions from D-luciferin in the green to red regions of the electromagnetic spectrum. Although blue-emitting luciferases are known from marine organisms, they belong to different structural families and use a different substrate. The observation of blue emission from a D-luciferin-using enzyme is therefore unprecedented. PMID:27457804

  1. The urge to prove and its ills.

    PubMed

    Yazici, Hasan

    2013-01-01

    The urge to prove rather than the healthy self-critique is much in vogue. This trend ranges from our haste in making our research findings public before they go through the traditional peer review to almost every domain of our activity as physicians and scientists. We seem to be in general content with what we know about disease mechanisms, our ability to diagnose, treat, and prevent. I propose that this lack of self-critique is also an important component of the less than desired status of the physician-drug industry relationship. What is more worrying is that the physicians seem to take as the norm that if there is drug industry sponsoring in a study the results are always tainted. I propose that "our urge to prove" is very much behind this unfortunate state of affairs. I like to think the more we stay away from the urge to prove and bring in cerebral activity in the direction of self-critique much less likely will the drug industry be able to meddle in our affairs. PMID:24032611

  2. Bayesian analysis of exoplanet and binary orbits. Demonstrated using astrometric and radial-velocity data of Mizar A

    NASA Astrophysics Data System (ADS)

    Schulze-Hartung, T.; Launhardt, R.; Henning, T.

    2012-09-01

    Aims: We introduce BASE (Bayesian astrometric and spectroscopic exoplanet detection and characterisation tool), a novel program for the combined or separate Bayesian analysis of astrometric and radial-velocity measurements of potential exoplanet hosts and binary stars. The capabilities of BASE are demonstrated using all publicly available data of the binary Mizar A. Methods: With the Bayesian approach to data analysis we can incorporate prior knowledge and draw extensive posterior inferences about model parameters and derived quantities. This was implemented in BASE by Markov chain Monte Carlo (MCMC) sampling, using a combination of the Metropolis-Hastings, hit-and-run, and parallel-tempering algorithms to explore the whole parameter space. Nonconvergence to the posterior was tested by means of the Gelman-Rubin statistic (potential scale reduction). The samples were used directly and transformed into marginal densities by means of kernel density estimation, a "smooth" alternative to histograms. We derived the relevant observable models from Newton's law of gravitation, showing that the motion of Earth and the target can be neglected. Results: With our methods we can provide more detailed information about the parameters than a frequentist analysis does. Still, a comparison with the Mizar A literature shows that both approaches are compatible within the uncertainties. Conclusions: We show that the Bayesian approach to inference has been implemented successfully in BASE, a flexible tool for analysing astrometric and radial-velocity data. BASE, the computer program introduced in this article, can be downloaded at http://www.mpia.de/homes/schulze/base.html.

  3. A non-enteric adenovirus A12 gastroenteritis outbreak in Rio de Janeiro, Brazil

    PubMed Central

    Portes, Silvana Augusta Rodrigues; Volotão, Eduardo de Mello; Rocha, Monica Simões; Rebelo, Maria Cristina; Xavier, Maria da Penha Trindade Pinheiro; de Assis, Rosane Maria; Rose, Tatiana Lundgren; Miagostovich, Marize Pereira; Leite, José Paulo Gagliardi; Carvalho-Costa, Filipe Anibal

    2016-01-01

    A gastroenteritis outbreak that occurred in 2013 in a low-income community in Rio de Janeiro was investigated for the presence of enteric viruses, including species A rotavirus (RVA), norovirus (NoV), astrovirus (HAstV), bocavirus (HBoV), aichivirus (AiV), and adenovirus (HAdV). Five of nine stool samples (83%) from patients were positive for HAdV, and no other enteric viruses were detected. Polymerase chain reaction products were sequenced and subjected to phylogenetic analysis, which revealed four strains and one strain of non-enteric HAdV-A12 and HAdV-F41, respectively. The HAdV-A12 nucleotide sequences shared 100% nucleotide similarity. Viral load was assessed using a TaqMan real-time PCR assay. Stool samples that were positive for HAdV-A12 had high viral loads (mean 1.9 X 107 DNA copies/g stool). All four patients with HAdV-A12 were < 25 months of age and had symptoms of fever and diarrhoea. Evaluation of enteric virus outbreaks allows the characterisation of novel or unique diarrhoea-associated viruses in regions where RVA vaccination is routinely performed. PMID:27223654

  4. Measurement Scale of the SOLIS Vector Spectromagnetograph

    NASA Technical Reports Server (NTRS)

    Jones, Harrison P.; Harvey, John W.; Henney, Carl J.; Keller, Christoph U.; Malanushenko, Olena M.

    2004-01-01

    Longitudinal magnetograms obtained with thc SOLIS Vector Spectromagnetograph (VSM) during a cross-calibration period are compared with similar data from the NASA/NSO Spectromagnetograph (SPM) at the NSO/Kitt Peak Vacuum Telescope as well as with SOHO/MDI and GONG magnetogram. The VSM began observation at the University of Arizona agricultural test site and collaborative observations were obtained with both the VSM and SPM from 2003 Aug 05 through 2003 Sep 21 where the SPM was officially retired. The VSM replaces the SPM and continues the 3O-year NSO/Kitt Peak synoptic magnetogram record. Magnetograms are compared by equating histograms and, for selected examples, by pixel-by-pixel comparison of co-registered images. The VSM was not corrected for polarization crosstalk and was operated without hast guiding. Solar activity was at best moderate during this period. Over the range of observed fields, the VSM magnetograms show greatly improved sensitivity but are otherwise virtually identical with "raw" SPM magnetogram. GONG magnetograms are also closely comparable with the SPM while MDI flux values tend to be stronger by a factor of 1.2 - 1.4. Dependence of the results on seeing will be discussed. Partial funding for this work was provided through Solar and Heliospheric Research Supporting Research and Technology grants from NASA's Office of Space Sciences.

  5. Potential effect of resonant scattering from multiple swimbladders on audition in juvenile fish

    NASA Astrophysics Data System (ADS)

    Hastings, Mardi C.

    2003-04-01

    The swimbladder, a gas-filled chamber in the abdominal cavity of most bony fishes, is a hydrostatic organ that enables fish to maintain neutral buoyancy; however, it also responds to acoustic pressure and radiates a secondary acoustic field that enhances detection capability of the inner ear. Recent experiments have indicated that resonant response of the swimbladder may control the auditory bandwidth in at least four species of fish [Hastings et al., J. Acoust. Soc. Am. 110, 2640 (2001)]. The auditory bandwidths of these fishes, however, do not change appreciably while they grow even though the resonance frequency of the swimbladder decreases with increasing body length. Results of an analysis inspired by Feiullade et al. [J. Acoust. Soc. Am. 112, 2206 (2002)] show that the downward shift and broadening associated with resonance of the aggregate scattered field from multiple fish is perhaps sufficient enough to account for this discrepancy. Effects of resonant characteristics of a single swimbladder, fish length, and number of fish on the changes in the collective scattered field are presented. Thus the resonant scattered field created by relatively large schools of juvenile fish may enhance their auditory capability.

  6. Flow and chloride transport in the tidal Hudson River, NY

    USGS Publications Warehouse

    Weiss, Lawrence A.; Schaffranek, Raymond W.; de Vries, M. Peter

    1994-01-01

    A one-dimensional dynamic-flow model and a one-dimensional solute-transport model were used to evaluate the effects of hypothetical public-supply water withdrawals on saltwater intrusion in a 133-mile reach of the tidal Hudson River between Green Island dam, near Troy, N.Y., and Hastings-on-Hudson, N.Y. Regression techniques were used in analyses of current and extreme historical conditions, and numerical models were used to investigate the effect of various water withdrawals. Of four withdrawal scenarios investigated, simulations of a 27-day period during which discharges at Green Island dam averaged 7,090 ft3/s indicate that increasing the present Chelsea pumping-station withdrawal rate of 100 Mgal/d (million gallons per day) to 300 Mgal/d would have the least effect on upstream saltwater movement. A 90-day simulation, during which discharges at Green Island dam averaged 25,200 ft3/s, indicates that withdrawals of 1,940 Mgal/d at Chelsea would not measurably increase chloride concentrations at Chelsea under normal tidal and meteorological conditions, but withdrawals of twice that rate (3,880 Mgal/d) could increase the chloride concentration at Chelsea to 250 mg/L.

  7. Time-resolved visible and infrared absorption spectroscopy data obtained using photosystem I particles with non-native quinones incorporated into the A1 binding site.

    PubMed

    Makita, Hiroki; Hastings, Gary

    2016-06-01

    Time-resolved visible and infrared absorption difference spectroscopy data at both 298 and 77 K were obtained using cyanobacterial menB (-) mutant photosystem I particles with several non-native quinones incorporated into the A1 binding site. Data was obtained for photosystem I particles with phylloquinone (2-methyl-3-phytyl-1,4-naphthoquinone), 2-bromo-1,4-naphthoquinone, 2-chloro-1,4-naphthoquinone, 2-methyl-1,4-naphthoquinone, 2,3-dibromo-1,4-naphthoquinone, 2,3-dichloro-1,4-naphthoquinone, and 9,10-anthraquinone incorporated. Transient absorption data were obtained at 487 and 703 nm in the visible spectral range, and 1950-1100 cm(-1) in the infrared region. Time constants obtained from fitting the time-resolved infrared and visible data are in good agreement. The measured time constants are crucial for the development of appropriate kinetic models that can describe electron transfer processes in photosystem I, "Modeling Electron Transfer in Photosystem I" Makita and Hastings (2016) [1].

  8. Transport map-accelerated Markov chain Monte Carlo for Bayesian parameter inference

    NASA Astrophysics Data System (ADS)

    Marzouk, Y.; Parno, M.

    2014-12-01

    We introduce a new framework for efficient posterior sampling in Bayesian inference, using a combination of optimal transport maps and the Metropolis-Hastings rule. The core idea is to use transport maps to transform typical Metropolis proposal mechanisms (e.g., random walks, Langevin methods, Hessian-preconditioned Langevin methods) into non-Gaussian proposal distributions that can more effectively explore the target density. Our approach adaptively constructs a lower triangular transport map—i.e., a Knothe-Rosenblatt re-arrangement—using information from previous MCMC states, via the solution of an optimization problem. Crucially, this optimization problem is convex regardless of the form of the target distribution. It is solved efficiently using Newton or quasi-Newton methods, but the formulation is such that these methods require no derivative information from the target probability distribution; the target distribution is instead represented via samples. Sequential updates using the alternating direction method of multipliers enable efficient and parallelizable adaptation of the map even for large numbers of samples. We show that this approach uses inexact or truncated maps to produce an adaptive MCMC algorithm that is ergodic for the exact target distribution. Numerical demonstrations on a range of parameter inference problems involving both ordinary and partial differential equations show multiple order-of-magnitude speedups over standard MCMC techniques, measured by the number of effectively independent samples produced per model evaluation and per unit of wallclock time.

  9. Virtual Goods Recommendations in Virtual Worlds

    PubMed Central

    Chen, Kuan-Yu; Liao, Hsiu-Yu; Chen, Jyun-Hung; Liu, Duen-Ren

    2015-01-01

    Virtual worlds (VWs) are computer-simulated environments which allow users to create their own virtual character as an avatar. With the rapidly growing user volume in VWs, platform providers launch virtual goods in haste and stampede users to increase sales revenue. However, the rapidity of development incurs virtual unrelated items which will be difficult to remarket. It not only wastes virtual global companies' intelligence resources, but also makes it difficult for users to find suitable virtual goods fit for their virtual home in daily virtual life. In the VWs, users decorate their houses, visit others' homes, create families, host parties, and so forth. Users establish their social life circles through these activities. This research proposes a novel virtual goods recommendation method based on these social interactions. The contact strength and contact influence result from interactions with social neighbors and influence users' buying intention. Our research highlights the importance of social interactions in virtual goods recommendation. The experiment's data were retrieved from an online VW platform, and the results show that the proposed method, considering social interactions and social life circle, has better performance than existing recommendation methods. PMID:25834837

  10. A coupled hidden Markov model for disease interactions.

    PubMed

    Sherlock, Chris; Xifara, Tatiana; Telfer, Sandra; Begon, Mike

    2013-08-01

    To investigate interactions between parasite species in a host, a population of field voles was studied longitudinally, with presence or absence of six different parasites measured repeatedly. Although trapping sessions were regular, a different set of voles was caught at each session, leading to incomplete profiles for all subjects. We use a discrete time hidden Markov model for each disease with transition probabilities dependent on covariates via a set of logistic regressions. For each disease the hidden states for each of the other diseases at a given time point form part of the covariate set for the Markov transition probabilities from that time point. This allows us to gauge the influence of each parasite species on the transition probabilities for each of the other parasite species. Inference is performed via a Gibbs sampler, which cycles through each of the diseases, first using an adaptive Metropolis-Hastings step to sample from the conditional posterior of the covariate parameters for that particular disease given the hidden states for all other diseases and then sampling from the hidden states for that disease given the parameters. We find evidence for interactions between several pairs of parasites and of an acquired immune response for two of the parasites.

  11. Developing a cosmic ray muon sampling capability for muon tomography and monitoring applications

    NASA Astrophysics Data System (ADS)

    Chatzidakis, S.; Chrysikopoulou, S.; Tsoukalas, L. H.

    2015-12-01

    In this study, a cosmic ray muon sampling capability using a phenomenological model that captures the main characteristics of the experimentally measured spectrum coupled with a set of statistical algorithms is developed. The "muon generator" produces muons with zenith angles in the range 0-90° and energies in the range 1-100 GeV and is suitable for Monte Carlo simulations with emphasis on muon tomographic and monitoring applications. The muon energy distribution is described by the Smith and Duller (1959) [35] phenomenological model. Statistical algorithms are then employed for generating random samples. The inverse transform provides a means to generate samples from the muon angular distribution, whereas the Acceptance-Rejection and Metropolis-Hastings algorithms are employed to provide the energy component. The predictions for muon energies 1-60 GeV and zenith angles 0-90° are validated with a series of actual spectrum measurements and with estimates from the software library CRY. The results confirm the validity of the phenomenological model and the applicability of the statistical algorithms to generate polyenergetic-polydirectional muons. The response of the algorithms and the impact of critical parameters on computation time and computed results were investigated. Final output from the proposed "muon generator" is a look-up table that contains the sampled muon angles and energies and can be easily integrated into Monte Carlo particle simulation codes such as Geant4 and MCNP.

  12. Performance of Thermal Mass Flow Meters in a Variable Gravitational Environment

    NASA Technical Reports Server (NTRS)

    Brooker, John E.; Ruff, Gary A.

    2004-01-01

    The performance of five thermal mass flow meters, MKS Instruments 179A and 258C, Unit Instruments UFM-8100, Sierra Instruments 830L, and Hastings Instruments HFM-200, were tested on the KC-135 Reduced Gravity Aircraft in orthogonal, coparallel, and counterparallel orientations relative to gravity. Data was taken throughout the parabolic trajectory where the g-level varied from 0.01 to 1.8 times normal gravity. Each meter was calibrated in normal gravity in the orthogonal position prior to flight followed by ground testing at seven different flow conditions to establish a baseline operation. During the tests, the actual flow rate was measured independently using choked-flow orifices. Gravitational acceleration and attitude had a unique effect on the performance of each meter. All meters operated within acceptable limits at all gravity levels in the calibrated orthogonal position. However, when operated in other orientations, the deviations from the reference flow became substantial for several of the flow meters. Data analysis indicated that the greatest source of error was the effect of orientation, followed by the gravity level. This work emphasized that when operating thermal flow meters in a variable gravity environment, it is critical to orient the meter in the same direction relative to gravity in which it was calibrated. Unfortunately, there was no test in normal gravity that could predict the performance of a meter in reduced gravity. When operating in reduced gravity, all meters indicated within 5 percent of the full scale reading at all flow conditions and orientations.

  13. Moisture in multilayer ceramic capacitors

    NASA Astrophysics Data System (ADS)

    Donahoe, Daniel Noel

    When both precious metal electrode and base metal electrode (BME) capacitors were subjected to autoclave (120°C/100% RH) testing, it was found that the precious metal capacitors aged according to a well known aging mechanism (less than 3% from their starting values), but the BME capacitors degraded to below the -30% criterion at 500 hours of exposure. The reasons for this new failure mechanism are complex, and there were two theories that were hypothesized. The first was that there could be oxidation or corrosion of the nickel plates. The other hypothesis was that the loss of capacitance was due to molecular changes in the barium titanate. This thesis presents the evaluation of these hypotheses and the physics of the degradation mechanism. It is concluded by proof by elimination that there are molecular changes in the barium titanate. Furthermore, the continuous reduction in capacitor size makes the newer base metal electrode capacitors more vulnerable to moisture degradation than the older generation precious metal capacitors. In addition, standard humidity life testing, such as JESD-22 THB and HAST, will likely not uncover this problem. Therefore, poor reliability due to degradation of base metal electrode multilayer ceramic capacitors may catch manufacturers and consumers by surprise.

  14. Local perturbations perturb—exponentially-locally

    NASA Astrophysics Data System (ADS)

    De Roeck, W.; Schütz, M.

    2015-06-01

    We elaborate on the principle that for gapped quantum spin systems with local interaction, "local perturbations [in the Hamiltonian] perturb locally [the groundstate]." This principle was established by Bachmann et al. [Commun. Math. Phys. 309, 835-871 (2012)], relying on the "spectral flow technique" or "quasi-adiabatic continuation" [M. B. Hastings, Phys. Rev. B 69, 104431 (2004)] to obtain locality estimates with sub-exponential decay in the distance to the spatial support of the perturbation. We use ideas of Hamza et al. [J. Math. Phys. 50, 095213 (2009)] to obtain similarly a transformation between gapped eigenvectors and their perturbations that is local with exponential decay. This allows to improve locality bounds on the effect of perturbations on the low lying states in certain gapped models with a unique "bulk ground state" or "topological quantum order." We also give some estimate on the exponential decay of correlations in models with impurities where some relevant correlations decay faster than one would naively infer from the global gap of the system, as one also expects in disordered systems with a localized groundstate.

  15. A Comparison of Homeless Male Veterans in Metropolitan and Micropolitan Areas in Nebraska: A Methodological Caveat.

    PubMed

    Tsai, Jack; Ramaswamy, Sriram; Bhatia, Subhash C; Rosenheck, Robert A

    2015-12-01

    This study explored differences between homeless male veterans in metropolitan and micropolitan cities in Nebraska on sociodemographic, housing, clinical, and psychosocial characteristics as well as health service use. A convenience sample of 151 homeless male veterans (112 metropolitan, 39 micropolitan) were recruited from Veterans Affairs facilities and area shelters in Omaha, Lincoln, Grand Island, and Hastings in Nebraska. Research staff conducted structured interviews with homeless veterans. Results showed that compared to homeless veterans in metropolitans, those in micropolitans were more likely to be White, unmarried, living in transitional settings, and were far more transient but reported greater social support and housing satisfaction. Veterans in micropolitans also reported more medical problems, diagnoses of anxiety and personality disorders, and unexpectedly, were more likely to report using various health services and less travel time for services. Together, these findings suggest access to homeless and health services for veterans in micropolitan areas may be facilitated through Veterans Affairs facilities and community providers that work in close proximity to one another. Many homeless veterans in these areas are transient, making them a difficult population to study and serve. Innovative ways to provide outreach to homeless veterans in micropolitan and more rural areas are needed.

  16. A simulation approach for change-points on phylogenetic trees.

    PubMed

    Persing, Adam; Jasra, Ajay; Beskos, Alexandros; Balding, David; De Iorio, Maria

    2015-01-01

    We observe n sequences at each of m sites and assume that they have evolved from an ancestral sequence that forms the root of a binary tree of known topology and branch lengths, but the sequence states at internal nodes are unknown. The topology of the tree and branch lengths are the same for all sites, but the parameters of the evolutionary model can vary over sites. We assume a piecewise constant model for these parameters, with an unknown number of change-points and hence a transdimensional parameter space over which we seek to perform Bayesian inference. We propose two novel ideas to deal with the computational challenges of such inference. Firstly, we approximate the model based on the time machine principle: the top nodes of the binary tree (near the root) are replaced by an approximation of the true distribution; as more nodes are removed from the top of the tree, the cost of computing the likelihood is reduced linearly in n. The approach introduces a bias, which we investigate empirically. Secondly, we develop a particle marginal Metropolis-Hastings (PMMH) algorithm, that employs a sequential Monte Carlo (SMC) sampler and can use the first idea. Our time-machine PMMH algorithm copes well with one of the bottle-necks of standard computational algorithms: the transdimensional nature of the posterior distribution. The algorithm is implemented on simulated and real data examples, and we empirically demonstrate its potential to outperform competing methods based on approximate Bayesian computation (ABC) techniques.

  17. Characterization of Interstellar Organic Molecules

    SciTech Connect

    Gencaga, Deniz; Knuth, Kevin H.; Carbon, Duane F.

    2008-11-06

    Understanding the origins of life has been one of the greatest dreams throughout history. It is now known that star-forming regions contain complex organic molecules, known as Polycyclic Aromatic Hydrocarbons (PAHs), each of which has particular infrared spectral characteristics. By understanding which PAH species are found in specific star-forming regions, we can better understand the biochemistry that takes place in interstellar clouds. Identifying and classifying PAHs is not an easy task: we can only observe a single superposition of PAH spectra at any given astrophysical site, with the PAH species perhaps numbering in the hundreds or even thousands. This is a challenging source separation problem since we have only one observation composed of numerous mixed sources. However, it is made easier with the help of a library of hundreds of PAH spectra. In order to separate PAH molecules from their mixture, we need to identify the specific species and their unique concentrations that would provide the given mixture. We develop a Bayesian approach for this problem where sources are separated from their mixture by Metropolis Hastings algorithm. Separated PAH concentrations are provided with their error bars, illustrating the uncertainties involved in the estimation process. The approach is demonstrated on synthetic spectral mixtures using spectral resolutions from the Infrared Space Observatory (ISO). Performance of the method is tested for different noise levels.

  18. Alternative Test Methods for Electronic Parts

    NASA Technical Reports Server (NTRS)

    Plante, Jeannette

    2004-01-01

    It is common practice within NASA to test electronic parts at the manufacturing lot level to demonstrate, statistically, that parts from the lot tested will not fail in service using generic application conditions. The test methods and the generic application conditions used have been developed over the years through cooperation between NASA, DoD, and industry in order to establish a common set of standard practices. These common practices, found in MIL-STD-883, MIL-STD-750, military part specifications, EEE-INST-002, and other guidelines are preferred because they are considered to be effective and repeatable and their results are usually straightforward to interpret. These practices can sometimes be unavailable to some NASA projects due to special application conditions that must be addressed, such as schedule constraints, cost constraints, logistical constraints, or advances in the technology that make the historical standards an inappropriate choice for establishing part performance and reliability. Alternate methods have begun to emerge and to be used by NASA programs to test parts individually or as part of a system, especially when standard lot tests cannot be applied. Four alternate screening methods will be discussed in this paper: Highly accelerated life test (HALT), forward voltage drop tests for evaluating wire-bond integrity, burn-in options during or after highly accelerated stress test (HAST), and board-level qualification.

  19. Molecular basis for the blue bioluminescence of the Australian glow-worm Arachnocampa richardsae (Diptera: Keroplatidae).

    PubMed

    Trowell, Stephen C; Dacres, Helen; Dumancic, Mira M; Leitch, Virginia; Rickards, Rodney W

    2016-09-16

    Bioluminescence is the emission of visible light by living organisms. Here we describe the isolation and characterisation of a cDNA encoding a MW ≈ 59,000 Da luciferase from the Australian glow-worm, Arachnocampa richardsae. The enzyme is a member of the acyl-CoA ligase superfamily and produces blue light on addition of D-luciferin. These results are contrary to earlier reports (Lee, J., Photochem Photobiol 24, 279-285 (1976), Viviani, V. R., Hastings, J. W. & Wilson, T., Photochem Photobiol 75, 22-27 (2002)), which suggested glow-worm luciferase has MW ≈ 36,000 Da and is unreactive with beetle luciferin. There are more than 2000 species of firefly, which all produce emissions from D-luciferin in the green to red regions of the electromagnetic spectrum. Although blue-emitting luciferases are known from marine organisms, they belong to different structural families and use a different substrate. The observation of blue emission from a D-luciferin-using enzyme is therefore unprecedented.

  20. Casemix based funding for private hospitals or there are still a number of options so can we please slow down.

    PubMed

    Herring, M M

    1991-01-01

    Australian private hospitals should ask themselves and answer four questions in relation to case mix based payment before they reach a firm decision of the merits of such funding. Firstly, does Australia in general and the private sector in particular need case mix based funding? Secondly, if we are to have case mix based funding, does it have to be based on DRGs and, in particular, the system in use in the United States--the Medicare prospective payment system? Thirdly, will the U.S. system be forced upon us? Fourthly, will sufficient time be allowed for development and phasing in of a new system? This paper addresses all these questions and argues that the case mix based system currently in use and being further developed within the private hospital sector may be a better proposition for long term private sector funding because of its relative simplicity and low administrative costs. The paper also urges less haste in the development and implementation of any radical change. PMID:10117334

  1. Are medical ethicists out of touch? Practitioner attitudes in the US and UK towards decisions at the end of life

    PubMed Central

    Dickenson, D.

    2000-01-01

    Objectives—To assess whether UK and US health care professionals share the views of medical ethicists about medical futility, withdrawing/withholding treatment, ordinary/extraordinary interventions, and the doctrine of double effect Design, subjects and setting–A 138-item attitudinal questionnaire completed by 469 UK nurses studying the Open University course on "Death and Dying" was compared with a similar questionnaire administered to 759 US nurses and 687 US doctors taking the Hastings Center course on "Decisions near the End of Life". Results–Practitioners accept the relevance of concepts widely disparaged by bioethicists: double effect, medical futility, and the distinctions between heroic/ordinary interventions and withholding/ withdrawing treatment. Within the UK nurses' group a "rationalist" axis of respondents who describe themselves as having "no religion" are closer to the bioethics consensus on withholding and withdrawing treatment. Conclusions—Professionals' beliefs differ substantially from the recommendations of their professional bodies and from majority opinion in bioethics. Bioethicists should be cautious about assuming that their opinions will be readily accepted by practitioners. Key Words: Death and dying • withdrawal of care • refusal of treatment PMID:10951920

  2. Saline as the Sole Contrast Agent for Successful MRI-guided Epidural Injections

    SciTech Connect

    Deli, Martin; Mateiescu, Serban Busch, Martin; Becker, Jan Garmer, Marietta Groenemeyer, Dietrich

    2013-06-15

    Purpose. To assess the performance of sterile saline solution as the sole contrast agent for percutaneous magnetic resonance imaging (MRI)-guided epidural injections at 1.5 T. Methods. A retrospective analysis of two different techniques of MRI-guided epidural injections was performed with either gadolinium-enhanced saline solution or sterile saline solution for documentation of the epidural location of the needle tip. T1-weighted spoiled gradient echo (FLASH) images or T2-weighted single-shot turbo spin echo (HASTE) images visualized the test injectants. Methods were compared by technical success rate, image quality, table time, and rate of complications. Results. 105 MRI-guided epidural injections (12 of 105 with gadolinium-enhanced saline solution and 93 of 105 with sterile saline solution) were performed successfully and without complications. Visualization of sterile saline solution and gadolinium-enhanced saline solution was sufficient, good, or excellent in all 105 interventions. For either test injectant, quantitative image analysis demonstrated comparable high contrast-to-noise ratios of test injectants to adjacent body substances with reliable statistical significance levels (p < 0.001). The mean table time was 22 {+-} 9 min in the gadolinium-enhanced saline solution group and 22 {+-} 8 min in the saline solution group (p = 0.75). Conclusion. Sterile saline is suitable as the sole contrast agent for successful and safe percutaneous MRI-guided epidural drug delivery at 1.5 T.

  3. Nodal predictive error model and Bayesian approach for thermal diffusivity and heat source mapping

    NASA Astrophysics Data System (ADS)

    Massard, H.; Fudym, Olivier; Orlande, H. R. B.; Batsale, J. C.

    2010-07-01

    This article aims at solving a two-dimensional inverse heat conduction problem in order to retrieve both the thermal diffusivity and heat source field in a thin plate. A spatial random heat pulse is applied to the plate and the thermal response is analysed. The inverse approach is based on the minimisation of a nodal predictive error model, which yields a linear estimation problem. As a result of this approach, the sensitivity matrix is directly filled with experimental data, and thus is partially noisy. Bayesian estimators, such as the Maximum A Posteriori and a Markov Chain Monte Carlo approach (Metropolis-Hastings), are implemented and compared with the Ordinary Least Squares solution. Simulated temperature measurements are used in the inverse analysis. The nodal strategy relies on the availability of temperature measurements with fine spatial resolution and high frequency, typical of nowadays infrared cameras. The effects of both the measurement errors and of the model errors on the inverse problem solution are also analysed.

  4. Primary charge separation in isolated photosystem II reaction centers

    SciTech Connect

    Seibert, M.; Toon, S.; Govindjee; O`Neil, M.P.; Wasielewski, M.R.

    1992-08-24

    Primary charge-separation in isolated bacterial reaction center (RC) complex occurs in 2.8 ps at room temperature and 0.7--1.2 ps at 10 K. Because of similarities between the bacterial and photosystem II (PSII) RCs, it has been of considerable interest to obtain analogous charge-separation rates in the higher plant system. Our previous femtosecond transient absorption studies used PSII RC material stabilized with PEG or by exchanging dodecyl maltoside (DM) for Triton in the isolation procedure. These materials gave charge-separation 1/e times of 3.0 {plus_minus} 0.6 ps at 4{degree}C and 1.4{plus_minus} 0.2 ps at 15 K based on the risetime of transient absorption kinetics at 820 nm. These values were thought to represent the time required for formation of the P680{sup +}-Pheo{sup {minus}} state. Recent results of Hastings et al. obtained at high data acquisition rates and low flash intensities, suggest that the Pheo{sup {minus}} state may form more slowly. In light of this work, we have carried out additional time domain studies of both electron transport and energy transfer phenomena in stabilized DM PSII RCs at room temperature. We used a 1-kHz repetition rate femtosecond transient absorption spectrometer with a 200 fs instrumental time resolution and compared the results with those obtained by others using frequency domain hole-burning techniques.

  5. GRID-BASED EXPLORATION OF COSMOLOGICAL PARAMETER SPACE WITH SNAKE

    SciTech Connect

    Mikkelsen, K.; Næss, S. K.; Eriksen, H. K.

    2013-11-10

    We present a fully parallelized grid-based parameter estimation algorithm for investigating multidimensional likelihoods called Snake, and apply it to cosmological parameter estimation. The basic idea is to map out the likelihood grid-cell by grid-cell according to decreasing likelihood, and stop when a certain threshold has been reached. This approach improves vastly on the 'curse of dimensionality' problem plaguing standard grid-based parameter estimation simply by disregarding grid cells with negligible likelihood. The main advantages of this method compared to standard Metropolis-Hastings Markov Chain Monte Carlo methods include (1) trivial extraction of arbitrary conditional distributions; (2) direct access to Bayesian evidences; (3) better sampling of the tails of the distribution; and (4) nearly perfect parallelization scaling. The main disadvantage is, as in the case of brute-force grid-based evaluation, a dependency on the number of parameters, N{sub par}. One of the main goals of the present paper is to determine how large N{sub par} can be, while still maintaining reasonable computational efficiency; we find that N{sub par} = 12 is well within the capabilities of the method. The performance of the code is tested by comparing cosmological parameters estimated using Snake and the WMAP-7 data with those obtained using CosmoMC, the current standard code in the field. We find fully consistent results, with similar computational expenses, but shorter wall time due to the perfect parallelization scheme.

  6. Stochastic Tracking of Infection in a CF Lung

    PubMed Central

    Zarei, Sara; Mirtar, Ali; Rohwer, Forest; Salamon, Peter

    2014-01-01

    Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) scan are the two ubiquitous imaging sources that physicians use to diagnose patients with Cystic Fibrosis (CF) or any other Chronic Obstructive Pulmonary Disease (COPD). Unfortunately the cost constraints limit the frequent usage of these medical imaging procedures. In addition, even though both CT scan and MRI provide mesoscopic details of a lung, in order to obtain microscopic information a very high resolution is required. Neither MRI nor CT scans provide micro level information about the location of infection in a binary tree structure the binary tree structure of the human lung. In this paper we present an algorithm that enhances the current imaging results by providing estimated micro level information concerning the location of the infection. The estimate is based on a calculation of the distribution of possible mucus blockages consistent with available information using an offline Metropolis-Hastings algorithm in combination with a real-time interpolation scheme. When supplemented with growth rates for the pockets of mucus, the algorithm can also be used to estimate how lung functionality as manifested in spirometric tests will change in patients with CF or COPD. PMID:25360611

  7. Electric utility privatization: What we can learn from the British experience

    SciTech Connect

    Hyman, L.S.

    1997-10-01

    The most famous privatization effort, that of the Thatcher government, put the concept on the front pages. It embraced privatization with zeal. The government raked in billions of pounds. Millions of new investors bought shares in dozens of companies. But the privatizations left a legacy of problems. One can learn from them. Privatizations shook up complacent enterprises, increasing their efficiency and decreasing the prices that customers paid (with the exception of water consumers). The efforts helped to revitalize London as a financial center, and launched enterprises that have now ventured forth from England`s green and pleasant land into the rest of the world. The UK also made sure that the British remained in control of all the new companies upon privatization. On the other side of the balance, the British government, on occasion, acted in haste, with meeting a politically imposed deadline more important than getting the structure right. It left a great deal of money on the table after each sale. It confused the appearance of competition with effective competition. It created a string of regulatory agencies that lacked the tools to effectively control the utilities absent the effective competition that was supposed to supplement light regulation. And the privatizations put a lot of people out of work in the regulated industries and the businesses that supplied them.

  8. Telos versus Praxis in Bioethics.

    PubMed

    Chambers, Tod S

    2016-09-01

    The authors of "A Conceptual Model for the Translation of Bioethics Research and Scholarship" argue that bioethics must respond to institutional pressures by demonstrating that it is having an impact in the world. Any impact, the authors observe, must be "informed" by the goals of the discipline of bioethics. The concept of bioethics as a discipline is central to their argument. They begin by citing an essay that Daniel Callahan wrote in the first issue of Hastings Center Studies. Callahan argued in this 1973 piece that bioethics had yet to attain the status of a discipline, and he lauded the freedom of being able to define a new discipline. Callahan's essay shares with Mathews and colleague's a peculiarity: neither ever defines what it means to refer to something as a "discipline." To define a discipline does mean attending to the intended end product of scholarly activity, so I concur with Mathews et al.'s focus on outcomes. But I am concerned that in their argument they confusingly entangle their understanding of an academic discipline's internal goals, its telos, with its potential to have an impact on the external world, its praxis. The confusion that this can bring exposes what I believe is a profound problem within bioethics, the discipline's peculiar and at times intellectually hazardous relationship with its institutional hosts. PMID:27649829

  9. Fatal road accidents among Finnish military conscripts: fatigue-impaired driving.

    PubMed

    Radun, Igor; Radun, Jenni E; Summala, Heikki; Sallinen, Mikael

    2007-11-01

    The aims of the present study were to determine the current prevalence of personal car usage for holiday trips among Finnish conscripts and to analyze conscripts' fatal road accidents. The data included questionnaire data collected from 259 young conscripts at a garrison in southeastern Finland and data on 46 fatal road accidents caused by conscripts during the years 1991-2004, extracted from the national database of fatal road accidents studied in depth. The questionnaire data showed that one-third (35.9%) of young Finnish conscripts had used personal cars to travel to or from the garrison in the preceding 2 months. More than one-half of them reported driving while fatigued (a majority reported several occasions of such driving). In addition to those driving themselves, 41.6% of the conscripts rode at least occasionally as a passenger in a car driven by a fellow conscript. Analysis of the fatality data showed that one-half of the conscripts' fatal accidents occurred on the way to or from the garrison or while on duty. Falling asleep was the main cause of all conscripts' accidents (34.8%), with the largest proportion occurring when departing for leave (42.9%). Haste (including speeding) was the second greatest factor contributing to accidents occurring on the way to or from the garrison (26.1%), whereas drunk driving (22.7%) and suspected suicides (18.2%) were typical of accidents occurring on leave.

  10. Autocracy and AIDS: the post-Banda challenge. Country focus: Malawi.

    PubMed

    Mhone, C S

    1996-10-01

    Hastings Banda ruled Malawi for three decades until 1993. During that period, it was considered taboo to publicly discuss sexual matters. Efforts to prevent and control the spread of HIV/AIDS therefore got fully underway only after the end of Banda's autocratic regime. There are now an estimated 225,000 cases of AIDS in Malawi. The Ministry of Health estimates that 33% of urban adults and 17% of rural adults are HIV positive, approximately 10% of the total population. In some urban areas, 33% of women attending antenatal clinics and 70-98% of prostitutes are HIV positive. The high prevalence of sexually transmitted diseases and the practice of dry sex are thought to be major cofactors in bringing about such high rates of HIV infection. Several surveys do, however, indicate that the rate of growth of the HIV epidemic may be slowing. Even if the projected decrease in the incidence of new infections actually occurs, the cumulative HIV prevalence will continue to increase. Malawi, one of the world's poorest nations, with a per capita income of $140 and a literacy rate of 47%, cannot afford the overwhelming burden of providing comprehensive care to the segment of its population which suffers with AIDS. The author stresses the need for AIDS education in primary schools, especially since many students drop out prior to secondary school.

  11. Painlevé Representation of Tracy-Widom{_β} Distribution for {β} = 6

    NASA Astrophysics Data System (ADS)

    Rumanov, Igor

    2016-03-01

    In Rumanov (J Math Phys 56:013508, 2015), we found explicit Lax pairs for the soft edge of beta ensembles with even integer values of {β}. Using this general result, the case {β = 6} is further considered here. This is the smallest even {β}, when the corresponding Lax pair and its relation to Painlevé II (PII) have not been known before, unlike cases {β = 2} and 4. It turns out that again everything can be expressed in terms of the Hastings-McLeod solution of PII. In particular, a second order nonlinear ordinary differential equation (ODE) for the logarithmic derivative of Tracy-Widom distribution for {β = 6} involving the PII function in the coefficients is found, which allows one to compute asymptotics for the distribution function. The ODE is a consequence of a linear system of three ODEs for which the local singularity analysis yields series solutions with exponents in the set 4/3, 1/3 and -2/3.

  12. Innovative Composite Wall System for Sheathing Masonry Walls

    SciTech Connect

    Wendt, Robert L.; Cavallo, James

    1997-09-25

    Existing Housing - Much of the older multifamily housing stock in the United States includes units in structures with uninsulated masonry walls. Included in this stock are two- and three-story walk-up apartments, larger apartment complexes, and public housing (both high- rise and townhouse). This older multifamily housing has seen years of heavy use that may have left the plaster wall marred or damaged. Long- term building settlement or movement may have cracked the plaster, sometimes severely. Moisture from invented kitchens and baths may have caused condensation on uninsulated exterior walls. At best this condensation has left stains on the paint or wallpaper. At worst it has supported mold and mildew growth, fouling the air and creating unhealthy living conditions. Deteriorating plaster and flaking paint also result from wet walls. The presence of flaking, lead-based paint in older (pre-1978) housing is a major public health concern. Children can suffer permanent mental handicaps and psychological disorders if they are subjected to elevated levels of lead, while adults can suffer hypertension and other maladies. Studies have found that, in some urban communities with older housing stocks, over 35% of children tested have elevated blood lead levels (Hastings, et al.: 1997). Nationally, nearly 22% of black, non-hispanic children living in pre-1946 housing were found to have elevated levels of lead in their blood (MWWR Article: February 21,1997). The deterioration of many of these walls is to the point that lead can freely enter the living space.

  13. Bayesian model comparison of nonlinear structural equation models with missing continuous and ordinal categorical data.

    PubMed

    Lee, Sik-Yum; Song, Xin-Yuan

    2004-05-01

    Missing data are very common in behavioural and psychological research. In this paper, we develop a Bayesian approach in the context of a general nonlinear structural equation model with missing continuous and ordinal categorical data. In the development, the missing data are treated as latent quantities, and provision for the incompleteness of the data is made by a hybrid algorithm that combines the Gibbs sampler and the Metropolis-Hastings algorithm. We show by means of a simulation study that the Bayesian estimates are accurate. A Bayesian model comparison procedure based on the Bayes factor and path sampling is proposed. The required observations from the posterior distribution for computing the Bayes factor are simulated by the hybrid algorithm in Bayesian estimation. Our simulation results indicate that the correct model is selected more frequently when the incomplete records are used in the analysis than when they are ignored. The methodology is further illustrated with a real data set from a study concerned with an AIDS preventative intervention for Filipina sex workers.

  14. Land subsidence associated with hydrocarbon production, Texas Gulf Coast

    SciTech Connect

    Kreitler, C.W.; White, W.A.; Akhter, M.S.

    1988-01-01

    Although ground-water withdrawal has been the predominant cause of land subsidence in the Texas Gulf Coast, localized subsidence and faulting have also resulted from hydrocarbon production. Subsidence was documented as early as the 1920s over the Goose Creek field. Since then, subsidence and/or faulting have been identified over the Saxet, South Houston, Chocolate Bayou, Hastings, Alco-Mag, Clinton, Mykawa, Blue Ridge, Webster, and Caplen oil fields. Oil-production-related subsidence over these fields generally creates few environmental or engineering problems. One exception is the subsidence and faulting over the Caplen oil field on Bolivar Peninsula, where more than 1,000 ac of saltwater marsh has been replaced by subaqueous flats. Subsidence may be occurring over other fields but has not been identified because of limited releveled benchmark data. An evaluation of drill-stem and bottom-hole pressure data for the Frio Formation in Texas indicates extensive depressurization presumably from hydrocarbon production. Nearly 12,000 measurements from a pressure data base of 17,000 measurements indicate some depressurization. Some of the Frio zones have pressure declines of more than 1,500 psi from original hydrostatic conditions. Subsidence and faulting may be associated with these fields in the Frio as well as other Tertiary formations where extensive hydrocarbon production and subsequent depressurization have occurred.

  15. The High Flux Beam Reactor at Brookhaven National Laboratory

    SciTech Connect

    Shapiro, S.M.

    1994-12-31

    Brookhaven National Laboratory`s High Flux Beam Reactor (HFBR) was built because of the need of the scientist to always want `more`. In the mid-50`s the Brookhaven Graphite reactor was churning away producing a number of new results when the current generation of scientists, led by Donald Hughes, realized the need for a high flux reactor and started down the political, scientific and engineering path that led to the BFBR. The effort was joined by a number of engineers and scientists among them, Chemick, Hastings, Kouts, and Hendrie, who came up with the novel design of the HFBR. The two innovative features that have been incorporated in nearly all other research reactors built since are: (i) an under moderated core arrangement which enables the thermal flux to peak outside the core region where beam tubes can be placed, and (ii) beam tubes that are tangential to the core which decrease the fast neutron background without affecting the thermal beam intensity. Construction began in the fall of 1961 and four years later, at a cost of $12 Million, criticality was achieved on Halloween Night, 1965. Thus began 30 years of scientific accomplishments.

  16. Emergency Medical Services Public Health Implications and Interim Guidance for the Ebola Virus in the United States

    PubMed Central

    McCoy, Christopher E.; Lotfipour, Shahram; Chakravarthy, Bharath; Schultz, Carl; Barton, Erik

    2014-01-01

    The 25th known outbreak of the Ebola Virus Disease (EVD) is now a global public health emergency and the World Health Organization (WHO) has declared the epidemic to be a Public Health Emergency of International Concern (PHEIC). Since the first cases of the West African epidemic were reported in March 2014, there has been an increase in infection rates of over 13,000% over a 6-month period. The Ebola virus has now arrived in the United States and public health professionals, doctors, hospitals, Emergency Medial Services Administrators, Medical Directors, and policy makers have been working with haste to develop strategies to prevent the disease from reaching epidemic proportions. Prehospital care providers (emergency medical technicians and paramedics) and medical first responders (including but not limited to firefighters and law enforcement) are the healthcare systems front lines when it comes to first medical contact with patients outside of the hospital setting. Risk of contracting Ebola can be particularly high in this population of first responders if the appropriate precautions are not implemented. This article provides a brief clinical overview of the Ebola Virus Disease and provides a comprehensive summary of the Center for Disease Control and Prevention’s Interim Guidance for Emergency Medical Services (EMS) Systems and 9-1-1 Public Safety Answering Points (PSAPS) for Management of Patients with Known of Suspected Ebola Virus Disease in the United States. PMID:25493108

  17. Sensitivity analysis of an urban stormwater microorganism model.

    PubMed

    McCarthy, D T; Deletic, A; Mitchell, V G; Diaper, C

    2010-01-01

    This paper presents the sensitivity analysis of a newly developed model which predicts microorganism concentrations in urban stormwater (MOPUS--MicroOrganism Prediction in Urban Stormwater). The analysis used Escherichia coli data collected from four urban catchments in Melbourne, Australia. The MICA program (Model Independent Markov Chain Monte Carlo Analysis), used to conduct this analysis, applies a carefully constructed Markov Chain Monte Carlo procedure, based on the Metropolis-Hastings algorithm, to explore the model's posterior parameter distribution. It was determined that the majority of parameters in the MOPUS model were well defined, with the data from the MCMC procedure indicating that the parameters were largely independent. However, a sporadic correlation found between two parameters indicates that some improvements may be possible in the MOPUS model. This paper identifies the parameters which are the most important during model calibration; it was shown, for example, that parameters associated with the deposition of microorganisms in the catchment were more influential than those related to microorganism survival processes. These findings will help users calibrate the MOPUS model, and will help the model developer to improve the model, with efforts currently being made to reduce the number of model parameters, whilst also reducing the slight interaction identified.

  18. Time-efficient fast spin echo imaging at 4.7 T with low refocusing angles.

    PubMed

    Lebel, R Marc; Wilman, Alan H

    2009-07-01

    An implementation of fast spin echo at 4.7 T designed for versatile and time-efficient T(2)-weighted imaging of the human brain is presented. Reduced refocusing angles (alpha < 180 degrees) were employed to overcome specific absorption rate (SAR) constraints and their effects on image quality assessed. Image intensity and tissue contrast variations from heterogeneous RF transmit fields and incidental magnetization transfer effects were investigated at reduced refocusing angles. We found that intraslice signal variations are minimized with refocusing angles near 180 degrees, but apparent gray/white matter contrast is independent of refocusing angle. Incidental magnetization transfer effects from multislice acquisitions were shown to attenuate white matter intensity by 25% and gray matter intensity by 15% at 180 degrees; less than 5% attenuation was seen in all tissues at flip angles below 60 degrees. We present multislice images acquired without excess delay time for SAR mitigation using a variety of protocols. Subsecond half Fourier acquisition single-shot turbo spin echo (HASTE) images were obtained with a novel variable refocusing angle echo train (20 degrees < alpha < 58 degrees) and high-resolution scans with a voxel volume of 0.18 mm(3) were acquired in 6.5 min with refocusing angles of 100 degrees.

  19. Coercivity enhancement of sintered Nd-Fe-B magnets by chemical bath deposition of TbCl{sub 3}

    SciTech Connect

    Guo, Shuai Zhang, Xiaofeng; Ding, Guangfei; Chen, Renjie; Yan, Aru; Lee, Don

    2014-05-07

    The chemical bath deposition (CBD) and the grain boundary diffusion method were combined to diffuse the heavy rare earth for obtain the thick magnets with high coercivity and low heavy rare earth. The jet mill powders were soaked into the alcohol solution of 0.2 wt. % TbCl{sub 3}. A thin layer of TbCl{sub 3} was wrapped to the surface of (PrNd){sub 2}Fe{sub 14}B powder particles. The coercivity of magnet is increased from 11.89 kOe to 14.72 kOe without significant reduction of remanence after grain boundary diffusion in the sintering and the annealing processes. The temperature coefficients of the remanence and the coercivity are improved by the substitution of PrNd by Tb in the surface of grains. The highly accelerated temperature/humidity stress test (HAST) results indicate that the CBD magnet has poor corrosion resistance, attributing to the present of Cl atoms in the grain boundaries.

  20. [Sevoflurane optimal dosage estimation for myocardium pharmacological postconditioning: an experimental study].

    PubMed

    Grishin, A V; Iavorovskiĭ, A G; Zhidkov, I L; Charchian, É R; Ivanova, A G; Paliulina, M V; Sitnichenko, N V

    2013-01-01

    We estimated the optimal dosage of inhalation anesthetic sevoflurane, for the maximum cardioprotective effect with minimal angioparalytic action. 25 pigs were included in this study, they were divided into 5 groups, depending on the sevoflurane dosage used for pharmacological postconditioning (PPC): control group - PPC has't been conducted, a group of PPC 0.5 - sevoflurane PPC in a dose of 0.5 V%, a group of PPC 1.0 - sevoflurane PPC in a dose of 1.0 V%, a group of PPC 1.5 - sevoflurane PPC in a dose of 1.5 V%, a group of PPC 2.0 - sevoflurane PPC in a dose of 2.0 V%, a group of PPC 2.5 - sevoflurane PPC in a dose of 2.5 V%. Ischemia was simulated by left coronary artery crossclamping. Further PPC was held according to the following Protocol: 20 min before left coronary artery clamp off and first 20 min of reperfusion sevoflurane was given into CPB circuit. Myocardial ischemia period was 60 min in all groups. It was found and experimentally proved that the optimal sevoflurane dosage for PPC is 2 V%

  1. MR0175 -- A history and development study

    SciTech Connect

    Patrick, D.H.

    1999-07-01

    MR0175 is a NACE Materials Requirement that became an industry standard for Christmas Tree Valves in 1975. NACE altered MR0175 in 1978 to include other types of oil and gas production and completion equipment. Failures drove the early work and a disaster drove the 1978 version's development and the haste that NACE used to finish and publish the 1978 document. The paper traces events and documents that predate MR0175 and that the oil and gas industry used to develop and write MR0175. The paper will discuss some of the circumstances that led to MR0175's format, wording and ambiguities. The paper attempts to convey what ideas the writers were trying to express. The paper discusses the portion of the industry and the types of equipment that MR0175 addressed--the philosophy scope. The paper takes up the original intent behind MR0175 and follows its application into other areas that MR0175 did not envision. The paper covers some of the current changes that are being made to MR0175. NACE Unit Committee T-1F is also working on a major possible revision in how MR0175 speaks to CRAS (Corrosion Resistant Alloys); the paper summarizes those possibilities. The paper attempts to differentiate between what MR0175 addresses and what the International Standards Organization (ISO) sour gas document is addressing through ISO/TC67/WG7.

  2. Broken Symmetries and Gapless Excitations of SU(N) Antiferromagnets Investigated With Variational Wavefunctions

    NASA Astrophysics Data System (ADS)

    Paramekanti, Arun; Marston, Brad

    2005-03-01

    We use Gutzwiller-projected wavefunctions to investigate variationally the phase diagrams of SU(N) quantum antiferromagnets in the self-conjugate representation. The method is first tested against the known phase diagram of a one-dimensional SU(4) bilinear-biquadratic spin chain which has a quantum-critical point separating a dimerized phase from a phase with spontaneously broken charge-conjugation symmetryootnotetextI. Affleck et al., Nucl. Phys. B 366, 467 (1991).. In the case of two-dimensional SU(N) antiferromagnets, recent analyticalootnotetextM. Hermele et al., cond-mat/0404751http://arxiv.org/abs/cond-mat/0404751. and numericalootnotetextF. F. Assaad, cond-mat/0406074http://arxiv.org/abs/cond-mat/0406074. work suggests the existence of a gapless spin-liquid phase with no broken symmetries. Such a phase would be consistent with a recent generalization of the Lieb-Schultz-Mattis theoremootnotetextM. B. Hastings, Phys. Rev. B69, 104431 (2004); cond-mat/0411094http://arxiv.org/abs/cond-mat/0411094. to more than one spatial dimension. We examine the stability of the π-flux phase against tendencies to spin-order, crystallize into various valence-bond solids, or break charge-conjugation symmetry.

  3. Stokes phenomena and non-perturbative completion in the multi-cut two-matrix models

    NASA Astrophysics Data System (ADS)

    Chan, Chuan-Tsung; Irie, Hirotaka; Yeh, Chi-Hsien

    2012-01-01

    The Stokes multipliers in the matrix models are invariants in the string-theory moduli space and related to the D-instanton chemical potentials. They not only represent non-perturbative information but also play an important role in connecting various perturbative string theories in the moduli space. They are a key concept to the non-perturbative completion of string theory and also expected to imply some remnant of strong coupling dynamics in M theory. In this paper, we investigate the non-perturbative completion problem consisting of two constraints on the Stokes multipliers. As the first constraint, Stokes phenomena which realize the multi-cut geometry are studied in the Z symmetric critical points of the multi-cut two-matrix models. Sequence of solutions to the constraints are obtained in general k-cut critical points. A discrete set of solutions and a continuum set of solutions are explicitly shown, and they can be classified by several constrained configurations of the Young diagram. As the second constraint, we discuss non-perturbative stability of backgrounds in terms of the Riemann-Hilbert problem. In particular, our procedure in the 2-cut (1,2) case (pure-supergravity case) completely fixes the D-instanton chemical potentials and results in the Hastings-McLeod solution to the Painlevé II equation. It is also stressed that the Riemann-Hilbert approach realizes an off-shell background independent formulation of non-critical string theory.

  4. Fredholm Determinants and Pole-free Solutions to the Noncommutative Painlevé II Equation

    NASA Astrophysics Data System (ADS)

    Bertola, M.; Cafasso, M.

    2012-02-01

    We extend the formalism of integrable operators à la Its-Izergin-Korepin-Slavnov to matrix-valued convolution operators on a semi-infinite interval and to matrix integral operators with a kernel of the form {E_1^T(λ) E_2(μ)/λ+μ}, thus proving that their resolvent operators can be expressed in terms of solutions of some specific Riemann-Hilbert problems. We also describe some applications, mainly to a noncommutative version of Painlevé II (recently introduced by Retakh and Rubtsov) and a related noncommutative equation of Painlevé type. We construct a particular family of solutions of the noncommutative Painlevé II that are pole-free (for real values of the variables) and hence analogous to the Hastings-McLeod solution of (commutative) Painlevé II. Such a solution plays the same role as its commutative counterpart relative to the Tracy-Widom theorem, but for the computation of the Fredholm determinant of a matrix version of the Airy kernel.

  5. Non-Intersecting Squared Bessel Paths at a Hard-Edge Tacnode

    NASA Astrophysics Data System (ADS)

    Delvaux, Steven

    2013-12-01

    The squared Bessel process is a 1-dimensional diffusion process related to the squared norm of a higher dimensional Brownian motion. We study a model of n non-intersecting squared Bessel paths, with all paths starting at the same point a > 0 at time t = 0 and ending at the same point b > 0 at time t = 1. Our interest lies in the critical regime ab = 1/4, for which the paths are tangent to the hard edge at the origin at a critical time . The critical behavior of the paths for n → ∞ is studied in a scaling limit with time t = t * + O( n -1/3) and temperature T = 1 + O( n -2/3). This leads to a critical correlation kernel that is defined via a new Riemann-Hilbert problem of size 4 × 4. The Riemann-Hilbert problem gives rise to a new Lax pair representation for the Hastings-McLeod solution to the inhomogeneous Painlevé II equation q''( x) = xq( x) + 2 q 3( x) - ν, where ν = α + 1/2 with α > -1 the parameter of the squared Bessel process. These results extend our recent work with Kuijlaars and Zhang (Comm Pure Appl Math 64:1305-1383, 2011) for the homogeneous case ν = 0.

  6. Joint distribution of the first and second eigenvalues at the soft edge of unitary ensembles

    NASA Astrophysics Data System (ADS)

    Witte, N. S.; Bornemann, F.; Forrester, P. J.

    2013-06-01

    The density function for the joint distribution of the first and second eigenvalues at the soft edge of unitary ensembles is found in terms of a Painlevé II transcendent and its associated isomonodromic system. As a corollary, the density function for the spacing between these two eigenvalues is similarly characterized.The particular solution of Painlevé II that arises is a double shifted Bäcklund transformation of the Hastings-McLeod solution, which applies in the case of the distribution of the largest eigenvalue at the soft edge. Our deductions are made by employing the hard-to-soft edge transition, involving the limit as the repulsion strength at the hard edge a → ∞, to existing results for the joint distribution of the first and second eigenvalue at the hard edge (Forrester and Witte 2007 Kyushu J. Math. 61 457-526). In addition recursions under a ↦ a + 1 of quantities specifying the latter are obtained. A Fredholm determinant type characterization is used to provide accurate numerics for the distribution of the spacing between the two largest eigenvalues.

  7. Automatic Iceball Segmentation With Adapted Shape Priors for MRI-Guided Cryoablation

    PubMed Central

    Liu, Xinyang; Tuncali, Kemal; Wells, William M.; Zientara, Gary P.

    2014-01-01

    Purpose To develop and evaluate an automatic segmentation method that extracts the 3D configuration of the ablation zone, the iceball, from images acquired during the freezing phase of MRI-guided cryoablation. Materials and Methods Intraprocedural images at 63 timepoints from 13 kidney tumor cryoablation procedures were examined retrospectively. The images were obtained using a 3 Tesla wide-bore MRI scanner and axial HASTE sequence. Initialized with semiautomatically localized cryoprobes, the iceball was segmented automatically at each timepoint using the graph cut (GC) technique with adapted shape priors. Results The average Dice Similarity Coefficients (DSC), compared with manual segmentations, were 0.88, 0.92, 0.92, 0.93, and 0.93 at 3, 6, 9, 12, and 15 min time-points, respectively, and the average DSC of the total 63 segmentations was 0.92 ± 0.03. The proposed method improved the accuracy significantly compared with the approach without shape prior adaptation (P = 0.026). The number of probes involved in the procedure had no apparent influence on the segmentation results using our technique. The average computation time was 20 s, which was compatible with an intraprocedural setting. Conclusion Our automatic iceball segmentation method demonstrated high accuracy and robustness for practical use in monitoring the progress of MRI-guided cryoablation. PMID:24338961

  8. Learn-as-you-go acceleration of cosmological parameter estimates

    NASA Astrophysics Data System (ADS)

    Aslanyan, Grigor; Easther, Richard; Price, Layne C.

    2015-09-01

    Cosmological analyses can be accelerated by approximating slow calculations using a training set, which is either precomputed or generated dynamically. However, this approach is only safe if the approximations are well understood and controlled. This paper surveys issues associated with the use of machine-learning based emulation strategies for accelerating cosmological parameter estimation. We describe a learn-as-you-go algorithm that is implemented in the Cosmo++ code and (1) trains the emulator while simultaneously estimating posterior probabilities; (2) identifies unreliable estimates, computing the exact numerical likelihoods if necessary; and (3) progressively learns and updates the error model as the calculation progresses. We explicitly describe and model the emulation error and show how this can be propagated into the posterior probabilities. We apply these techniques to the Planck likelihood and the calculation of ΛCDM posterior probabilities. The computation is significantly accelerated without a pre-defined training set and uncertainties in the posterior probabilities are subdominant to statistical fluctuations. We have obtained a speedup factor of 6.5 for Metropolis-Hastings and 3.5 for nested sampling. Finally, we discuss the general requirements for a credible error model and show how to update them on-the-fly.

  9. Geothermal Energy Production from Oil/Gas Wells and Application for Building Cooling

    SciTech Connect

    Wang, Honggang; Liu, Xiaobing

    2016-01-01

    One significant source of low-temperature geothermal energy is the coproduced hot water from oil/gas field production. In the United States, daily oil production has reached above 8 million barrels in recent years. Considering various conditions of wells, 5-10 times or more water can be coproduced in the range of temperature 120 F to 300 F. Like other geothermal resources, such energy source from oil/gas wells is under-utilized for its typical long distance from consumption sites. Many oil/gas fields, however, are relatively close (less than 10 miles) to consumers around cities. For instance, some petroleum fields in Pennsylvania are only a few miles away from the towns in Pittsburg area and some fields in Texas are quite close to Houston. In this paper, we evaluate geothermal potential from oil/gas wells by conducting numerical simulation and analysis of a fractured oil well in Hastings West field, Texas. The results suggest that hot water can be continuously coproduced from oil wells at a sufficient rate (about 4000 gallons/day from one well) for more than 100 years. Viable use of such geothermal source requires economical transportation of energy to consumers. The recently proposed two-step geothermal absorption (TSGA) system provides a promising energy transport technology that allows large-scale use of geothermal energy from thousands of oil/gas wells.

  10. Earth's core and inner core resonances from analysis of VLBI nutation and superconducting gravimeter data

    NASA Astrophysics Data System (ADS)

    Rosat, S.; Lambert, S. B.; Gattano, C.; Calvo, M.

    2016-10-01

    Geophysical parameters of the deep Earth's interior can be evaluated through the resonance effects associated with the core and inner-core wobbles on the forced nutations of the Earth's figure axis, as observed by very long baseline interferometry (VLBI), or on the diurnal tidal waves, retrieved from the time-varying surface gravity recorded by superconducting gravimeters (SGs). In this paper, we inverse for the rotational mode parameters from both techniques to retrieve geophysical parameters of the deep Earth. We analyze surface gravity data from 15 SG stations and VLBI delays accumulated over the last 35 years. We show existing correlations between several basic Earth parameters and then decide to inverse for the rotational modes parameters. We employ a Bayesian inversion based on the Metropolis-Hastings algorithm with a Markov Chain Monte Carlo method. We obtain estimates of the free core nutation (FCN) resonant period and quality factor that are consistent for both techniques. We also attempt an inversion for the free inner core nutation (FICN) resonant period from gravity data. The most probable solution gives a period close to the annual prograde term (or S1 tide). However the 95% confidence interval extend the possible values between roughly 28 days and 725 days for gravity, and from 362 to 414 days from nutation data, depending on the prior bounds. The precisions of the estimated long-period nutation and respective small diurnal tidal constituents are hence not accurate enough for a correct determination of the FICN complex frequency.

  11. Bayesian analysis of the flutter margin method in aeroelasticity

    DOE PAGES

    Khalil, Mohammad; Poirel, Dominique; Sarkar, Abhijit

    2016-08-27

    A Bayesian statistical framework is presented for Zimmerman and Weissenburger flutter margin method which considers the uncertainties in aeroelastic modal parameters. The proposed methodology overcomes the limitations of the previously developed least-square based estimation technique which relies on the Gaussian approximation of the flutter margin probability density function (pdf). Using the measured free-decay responses at subcritical (preflutter) airspeeds, the joint non-Gaussain posterior pdf of the modal parameters is sampled using the Metropolis–Hastings (MH) Markov chain Monte Carlo (MCMC) algorithm. The posterior MCMC samples of the modal parameters are then used to obtain the flutter margin pdfs and finally the fluttermore » speed pdf. The usefulness of the Bayesian flutter margin method is demonstrated using synthetic data generated from a two-degree-of-freedom pitch-plunge aeroelastic model. The robustness of the statistical framework is demonstrated using different sets of measurement data. In conclusion, it will be shown that the probabilistic (Bayesian) approach reduces the number of test points required in providing a flutter speed estimate for a given accuracy and precision.« less

  12. Land subsidence caused by withdrawal of oil and gas in the Gulf coastal plain - The Houston, Texas, case history

    SciTech Connect

    Holzer, T.L. )

    1990-09-01

    The extensive network of geodetic leveling lines in the Houston-Galveston, Texas, area, where at least 110 oil and gas fields have been developed, provides the most comprehensive opportunity in the Gulf Coast to search for the occurrence of land subsidence caused by withdrawal of oil and gas. Although the evaluation is complicated by regional subsidence caused by a decline of ground-water level in aquifers beneath the area, subsidence caused by oil and gas withdrawal can be examined by searching for local increases of subsidence at oil and gas fields crossed by leveling lines. Twenty-nine fields are crossed by lines with repeated leveling surveys. Subsidence profiles across these fields indicate local increases of subsidence at six fields-Alco-Mag, Chocolate Bayou, Goose Creek, Hastings, Mykawa, and South Houston. Although ground-water withdrawal is undoubtedly the most important factor contributing to the total subsidence at each field, oil and gas withdrawal may be partly responsible for the local increases. Except for Chocolate Bayou, the volume of petroleum production at each field was sufficient to account for the increase. The volume of petroleum production, however, in general is not a reliable index for predicting the local increase because land within many fields with significant production did not show local increases of subsidence. With the exception of the 1 m subsidence caused by petroleum withdrawal at Goose Creek (1917-1925), local increases of subsidence were less than 0.3 m.

  13. Altering risky decision-making: Influence of impulsivity on the neuromodulation of prefrontal cortex.

    PubMed

    Cheng, Gordon L F; Lee, Tatia M C

    2016-01-01

    The prefrontal cortex (PFC) subserves complex cognitive abilities, including risky decision-making; the modulation of this brain area is shown to alter the way people take risks. Yet, neuromodulation of the PFC in relation to risk-taking behavior remains relatively less well-studied. Moreover, the psychological variables that influence such neuromodulation remain poorly understood. To address these issues, 16 participants took part in 3 experimental sessions on separate days. They received: (i) left anodal-right cathodal transcranial direct current stimulation (tDCS); (ii) left cathodal-right anodal stimulation; or (iii) sham stimulation while they completed two risk-taking tasks. They also measured on several cognitive-affective abilities and personality traits. It was revealed that left cathodal-right anodal stimulation led to significantly reduced risk-taking under a context of haste. The reduction of risk-taking (relative to sham) correlated with state and trait impulsivity, such that the effect was larger in more impulsive individuals. For these individuals, the tDCS effect size was considered to be large (generalized partial η(2) > .17). The effect of prefrontal-neuromodulation in reducing risk-taking was influenced by baseline impulsivity, reflecting a state-dependent effect of neuromodulation on the PFC. The results of this study carry important insights into the use of neuromodulation to alter higher cognition.

  14. A multivariate Poisson-lognormal regression model for prediction of crash counts by severity, using Bayesian methods.

    PubMed

    Ma, Jianming; Kockelman, Kara M; Damien, Paul

    2008-05-01

    Numerous efforts have been devoted to investigating crash occurrence as related to roadway design features, environmental factors and traffic conditions. However, most of the research has relied on univariate count models; that is, traffic crash counts at different levels of severity are estimated separately, which may neglect shared information in unobserved error terms, reduce efficiency in parameter estimates, and lead to potential biases in sample databases. This paper offers a multivariate Poisson-lognormal (MVPLN) specification that simultaneously models crash counts by injury severity. The MVPLN specification allows for a more general correlation structure as well as overdispersion. This approach addresses several questions that are difficult to answer when estimating crash counts separately. Thanks to recent advances in crash modeling and Bayesian statistics, parameter estimation is done within the Bayesian paradigm, using a Gibbs Sampler and the Metropolis-Hastings (M-H) algorithms for crashes on Washington State rural two-lane highways. Estimation results from the MVPLN approach show statistically significant correlations between crash counts at different levels of injury severity. The non-zero diagonal elements suggest overdispersion in crash counts at all levels of severity. The results lend themselves to several recommendations for highway safety treatments and design policies. For example, wide lanes and shoulders are key for reducing crash frequencies, as are longer vertical curves. PMID:18460364

  15. A consideration of the operation of automatic production machines

    PubMed Central

    HOSHI, Toshiro; SUGIMOTO, Noboru

    2015-01-01

    At worksites, various automatic production machines are in use to release workers from muscular labor or labor in the detrimental environment. On the other hand, a large number of industrial accidents have been caused by automatic production machines. In view of this, this paper considers the operation of automatic production machines from the viewpoint of accident prevention, and points out two types of machine operation − operation for which quick performance is required (operation that is not permitted to be delayed) − and operation for which composed performance is required (operation that is not permitted to be performed in haste). These operations are distinguished by operation buttons of suitable colors and shapes. This paper shows that these characteristics are evaluated as “asymmetric on the time-axis”. Here, in order for workers to accept the risk of automatic production machines, it is preconditioned in general that harm should be sufficiently small or avoidance of harm is easy. In this connection, this paper shows the possibility of facilitating the acceptance of the risk of automatic production machines by enhancing the asymmetric on the time-axis. PMID:25739898

  16. Rape and the prevalence of hybrids in broadly sympatric species: a case study using albatrosses

    PubMed Central

    Harris, Rebecca B.; Walsh, Hollie E.

    2014-01-01

    Conspecific rape often increases male reproductive success. However, the haste and aggression of forced copulations suggests that males may sometimes rape heterospecific females, thus making rape a likely, but undocumented, source of hybrids between broadly sympatric species. We present evidence that heterospecific rape may be the source of hybrids between Black-footed and Laysan Albatrosses (Phoebastria nigripes, and P. immutabilis, respectively). Extensive field studies have shown that paired (but not unpaired) males of both of these albatross species use rape as a supplemental reproductive strategy. Between species differences in size, timing of laying, and aggressiveness suggest that Black-footed Albatrosses should be more successful than Laysan Albatrosses in heteropspecific rape attempts, and male Black-footed Albatrosses have been observed attempting to force copulations on female Laysan Albatrosses. Nuclear markers showed that the six hybrids we studied were F1s and mitochondrial markers showed that male Black-footed Albatrosses sired all six hybrids. Long-term gene exchange between these species has been from Black-footed Albatrosses into Laysan Albatrosses, suggesting that the siring asymmetry found in our hybrids has long persisted. If hybrids are sired in heterospecific rapes, they presumably would be raised and sexually imprinted on Laysan Albatrosses, and two unmated hybrids in a previous study courted only Laysan Albatrosses. PMID:24949232

  17. The value of an evaluation framework for telehealth initiatives.

    PubMed

    Scott, R E; Coates, K; McCarthy, G F

    1999-01-01

    Healthcare managers and policy makers will, in the immediate and near future, make major decisions about the allocation of scarce healthcare resources for telehealth 'solutions'. In our haste to capitalize on what technology can do we may be obscuring discussion and research about what technology should do. For example, currently much attention is being paid to standardization for technological aspects of telehealth. In contrast few efforts have been made to seek standardization in regards to a broad evaluation framework for telehealth. A body of opinion believes that missing in our rush into the on-line world is a systematic approach to research into the human, social, cultural, economic, and political factors associated with healthcare. As a result we lack the tools and experience necessary to assess the true value and implications of telehealth 'solutions'. Developing general guidelines for an evaluation framework, from needs assessment through integrated research to post-study assessment, would greatly enhance the quality of decision making by healthcare managers and policy makers. We propose a model--the Telehealth Integrated Research Model (TIRM)--as the first step in encouraging discussion and development of an internationally accepted standardized telehealth evaluation framework.

  18. A study on operation efficiency evaluation based on firm's financial index and benchmark selection: take China Unicom as an example

    NASA Astrophysics Data System (ADS)

    Wu, Zu-guang; Tian, Zhan-jun; Liu, Hui; Huang, Rui; Zhu, Guo-hua

    2009-07-01

    Being the only listed telecom operators of A share market, China Unicom has always been attracted many institutional investors under the concept of 3G recent years,which itself is a great technical progress expectation.Do the institutional investors or the concept of technical progress have signficant effect on the improving of firm's operating efficiency?Though reviewing the documentary about operating efficiency we find that schoolars study this problem useing the regress analyzing based on traditional production function and data envelopment analysis(DEA) and financial index anayzing and marginal function and capital labor ratio coefficient etc. All the methods mainly based on macrodata. This paper we use the micro-data of company to evaluate the operating efficiency.Using factor analyzing based on financial index and comparing the factor score of three years from 2005 to 2007, we find that China Unicom's operating efficiency is under the averge level of benchmark corporates and has't improved under the concept of 3G from 2005 to 2007.In other words,institutional investor or the conception of technical progress expectation have faint effect on the changes of China Unicom's operating efficiency. Selecting benchmark corporates as post to evaluate the operating efficiency is a characteristic of this method ,which is basicallly sipmly and direct.This method is suit for the operation efficiency evaluation of agriculture listed companies because agriculture listed also face technical progress and marketing concept such as tax-free etc.

  19. Geochemistry of phlogopite, diopside, calcite, anhydrite and apatite pegmatites and syenites of southern Madagascar: evidence for crustal silicocarbonatitic (CSC) melt formation in a Panafrican collisional tectonic setting

    NASA Astrophysics Data System (ADS)

    Morteani, G.; Kostitsyn, Y. A.; Gilg, H. A.; Preinfalk, C.; Razakamanana, T.

    2013-04-01

    The phlogopite, diopside, calcite, anhydrite and apatite pegmatites of Ampandrandava and Beraketa are examples for the many other pegmatites of similar silicocarbonatitic composition found in the Bekily and Betroka-Beraketa Precambrian belts of southern Madagascar. The two studied pegmatites and associated syenites crystallised from immiscible silicocarbonatitic and peralkaline syenitic melts in a time span between 515 and 504 Ma in the final extensional phase of the Panafrican continental collision and connected metamorphic/metasomatic event. Model T Nd ages suggest that the melts were produced by partial melting of 3.5 Ga partially evaporitic continental crust. The studied pegmatites and genetically associated syenitic rocks are very rare examples for crustal silicocarbonatitic melts generated in a Panafrican collisional setting. The overwhelming majority of carbonatites and associated peralkaline rocks are mantle derived, much poorer in phosphate and sulfate and found in a cratonic environment. In light of the present results, genetic models for other sulfate- and phosphate-rich magmatic rocks (e.g., phlogopite-apatite-calcite mineralisations in the Grenville-Hasting formation in Canada and in the Sludyanka group in Eastern Siberia) should be reevaluated.

  20. Exposants geometriques des modeles de boucles dilues et idempotents des TLn-modules de la chaine de spins XXZ

    NASA Astrophysics Data System (ADS)

    Provencher, Guillaume

    This thesis is concerned with the study of critical phenomena for two-dimensional models on the lattice. Its results are contained in two articles: A first one, devoted to measuring geometric exponents, and a second one to the construction of idempotents for the XXZ spin chain projecting on indecomposable modules of the Temperley-Lieb algebra. Monte Carlo experiments, for a family of loop models in their dilute phase, are presented in the first article. Coined dilute loop models ( DLM ), this family is based upon an O (n) model introduced by Nienhuis (1990). It is defined by two coprime integers p, p' and an anisotropy parameter. In the continuum limit, DLM (p, p') is expected to yield a logarithmic conformal field theory of central charge c(kappa) = 13 - 6(kappa + kappa -1), where the ratio kappa = pp' is related to the loop gas fugacity beta = -2 cos pk . Critical exponents pertaining to valuable geometrical objects, namely the hull, external perimeter and red bonds, were measured. The Metropolis-Hastings algorithm, as well as several methods improving its efficiency, are presented. Despite the extrapolation of curves presenting large slopes, values as close as three to four digits from the theoretical predictions were attained through rigorous statistical analysis. The second article describes the decomposition of the XXZ spin chain Hilbert space ⊗n C2 using idempotents. The model of interest (Pasquier & Saleur (1990)) is described by a parameter-dependent Hamiltonian HXXZ (q), q ∈ Cx , expressible as a sum of elements of the Temperley-Lieb algebra TL n(q). The spectrum of HXXZ (q) in the continuum limit is also believed to be related to conformal field theories whose central charge is set by q. Using the quantum Schur-Weyl duality, an expression for the primitive idempotents of EndTLn ⊗n C2 , involving Uq sl2 elements, is obtained. These idempotents allow for the explicit construction of the indecomposable TLn-modules of ⊗ n C2 , all of which are

  1. δ 18Osw estimate for Globigerinoides ruber from core-top sediments in the East China Sea

    NASA Astrophysics Data System (ADS)

    Horikawa, Keiji; Kodaira, Tomohiro; Zhang, Jing; Murayama, Masafumi

    2015-12-01

    The paired analyses of the Mg/Ca ratio and oxygen isotopic composition ( δ 18Oc) of surface-dwelling planktonic foraminifera have become a widely used method for reconstructing the oxygen isotopic composition of ambient seawater ( δ 18Osw) as a robust proxy for surface salinity. Globigerinoides ruber ( G. ruber) is a mixed-layer dweller, and its fossil shell is an ideal archive for recording past sea surface water conditions, such as those caused by variability in the East Asian summer monsoon (EASM). Here, we investigate the validity of shell-derived δ 18Osw estimates for G. ruber using core-top sediments from the East China Sea (ECS). First, we determined a local δ 18Osw-salinity equation for the eastern part of the ECS in July [ δ 18Osw = -7.74 + 0.23 × salinity]. Then, we calculated δ 18Osw from core-top δ 18Oc and Mg/Ca values in G. ruber using the δ 18Oc-temperature equation of Bemis et al. (Paleoceanography 13(2):150-160, 1998) and the Mg/Ca-temperature equation of Hastings et al. (EOS 82:PP12B-10, 2001). The core-top δ 18Osw and salinity were estimated to be in the ranges of -0.2 to +0.39 ‰ and 33.7 to 34.5, respectively, which fall close to the local δ 18Osw-salinity regression line. The core-top data showed that the Mg/Ca-temperature calibration by Hastings et al. (EOS 82:PP12B-10, 2001) and the δ 18Oc-temperature equation by Bemis et al. (Paleoceanography 13(2):150-160, 1998) are appropriate for calculating δ 18Osw in the ECS. Furthermore, we measured core-top Ba/Ca ratios of G. ruber (Ba/Ca G. ruber ), which ranged from 0.66 to 2.82 μmol mol-1. There was not a significant relationship between the salinity and Ba/Ca G. ruber ratios due to the highly variable Ba/Ca G. ruber data. Given the seawater Ba/Ca data and the published partition coefficient for Ba ( D Ba = 0.15-0.22), pristine Ba/Ca G. ruber ratios at northern Okinawa Trough sites should be less than 0.84 μmol mol-1. Anomalously high Ba/Ca G. ruber ratios (>0.84 μmol mol-1) might

  2. Quantum dot transport in soil, plants, and insects.

    PubMed

    Al-Salim, Najeh; Barraclough, Emma; Burgess, Elisabeth; Clothier, Brent; Deurer, Markus; Green, Steve; Malone, Louise; Weir, Graham

    2011-08-01

    Environmental risk assessment of nanomaterials requires information not only on their toxicity to non-target organisms, but also on their potential exposure pathways. Here we report on the transport and fate of quantum dots (QDs) in the total environment: from soils, through their uptake into plants, to their passage through insects following ingestion. Our QDs are nanoparticles with an average particle size of 6.5 nm. Breakthrough curves obtained with CdTe/mercaptopropionic acid QDs applied to columns of top soil from a New Zealand organic apple orchard, a Hastings silt loam, showed there to be preferential flow through the soil's macropores. Yet the effluent recovery of QDs was just 60%, even after several pore volumes, indicating that about 40% of the influent QDs were filtered and retained by the soil column via some unknown exchange/adsorption/sequestration mechanism. Glycine-, mercaptosuccinic acid-, cysteine-, and amine-conjugated CdSe/ZnS QDs were visibly transported to a limited extent in the vasculature of ryegrass (Lolium perenne), onion (Allium cepa) and chrysanthemum (Chrysanthemum sp.) plants when cut stems were placed in aqueous QD solutions. However, they were not seen to be taken up at all by rooted whole plants of ryegrass, onion, or Arabidopsis thaliana placed in these solutions. Leafroller (Lepidoptera: Tortricidae) larvae fed with these QDs for two or four days, showed fluorescence along the entire gut, in their frass (larval feces), and, at a lower intensity, in their haemolymph. Fluorescent QDs were also observed and elevated cadmium levels detected inside the bodies of adult moths that had been fed QDs as larvae. These results suggest that exposure scenarios for QDs in the total environment could be quite complex and variable in each environmental domain. PMID:21632093

  3. Planning and implementing an honors degree in environmental science curricula: a case study from the University of Delaware, USA

    NASA Astrophysics Data System (ADS)

    Levia, Delphis

    2015-04-01

    advisory Environmental Council include Drs. Delphis Levia (Program Director & Chair), Nancy Targett (Dean), Frank Newton, Tracy Deliberty, Steve Hastings, John Madsen, Paul Imhoff, Jan Johnson, Jerry Kauffman, Murray Johnston.

  4. Characterization of leucocin B-Ta11a: a bacteriocin from Leuconostoc carnosum Ta11a isolated from meat.

    PubMed

    Felix, J V; Papathanasopoulos, M A; Smith, A A; von Holy, A; Hastings, J W

    1994-10-01

    Leuconostoc (Lc.) carnosum Ta11a, isolated from vacuum-packaged processed meats, produced a bacteriocin designated leucocin B-Ta11a. The crude bacteriocin was heat stable and sensitive to proteolytic enzymes, but not to catalase, lysozyme, or chloroform. It was active against Listeria monocytogenes and several lactic acid bacteria. Leucocin B-Ta11a was optimally produced at 25 degrees C in MRS broth at an initial pH of 6.0 or 6.5. An 8.9-MDa plasmid in Leuconostoc carnosum Ta11a hybridized to a 36-mer oligonucleotide probe (JF-1) that was homologous to leucocin A-UAL187. A 4.9-kb Sau3A fragment from a partial digest of the 8.9-MDa plasmid was cloned into pUC118. The 8.1-kb recombinant plasmid (pJF8.1) was used for sequencing and revealed the presence of two open reading frames (ORFs). ORF1 codes for a protein of 61 amino acids comprising a 37-amino-acid bacteriocin that was determined to be the leucocin B-Ta11a structural gene by virtue of its homology to leucocin A-UAL 187 (Hastings et al. 1991. J. Bacteriol 173:7491-7500). The 24-amino-acid N-terminal extension, however, differs from that of leucocin A-UAL187 by seven residues. The predicted protein of the ORF2 has 113 amino acids and is identical with the amino acid sequence of the cognate ORF of the leucocin A-UAL 187 operon.

  5. [Improvement of gynecologic radium therapy through the afterloading method using cesium 137].

    PubMed

    Fournier, D V; Senf, W; Kuttig, H; Kubli, F

    1976-03-01

    For all centers performing gynecological contact irradiation the use of afterloading techniques is urgently required, since they eliminate any radiation exposure to the personnel. The radio-therapist may position and control the empty applicators still free from radiation withoug haste. This procedure diminishes the occurrence of overdosages and underdosages. The care for the patients is possible without radiation exposure, and the morbidity of contact therapy can be reduced by occasional mobilization of the patient, the applicator without sources remaining at its place. The fully automatic apparatus "Curietron" using cesium-137 sources (0.662 MeV gamma emission, half-life period 26.6 years) with an equivalent source activity (factor 2.6) yields the dose distribution demanded in the gynecologic field which in practice is identical to that of Ra-226 (medium gamma emission 1 MeV, half-life period 1620 years). With similar dose distribution, a biological and therapeutical effect alike to Ra-226 may be expected from Cs-137. In comparison with Ra-226, the following advantages of Cs-137 may be mentioned: Lower half-value thickness of 5.5 mm lead (low expenses for radioprotection), less danger with handling (no emanation of radioactive gases), and lower contamination risks in case of breaking. The measured dose distributions at equivalent source activity and similar geometry of the applicators revealed the possibility with regard of all techniques of gynecologic irradiation utilized in our field of arriving at similar relative and absolute dose distributions by means of the Cs-137 afterloading technique. Whilst short-term afterloading irradiation with highly active sources, their radiobiological effectiveness being not yet ascertained, has to be tested at appropriate scientific centers, it is necessary to demand afterloading techniques with dosages and duration of irradiations approved over decades for all centers of gynecological contact therapy because of radiation

  6. Predicting the global warming potential of agro-ecosystems in Europe

    NASA Astrophysics Data System (ADS)

    Lehuger, S.; Gabrielle, B.; Chaumartin, F.

    2009-04-01

    Nitrous oxide, carbon dioxide and methane are the main biogenic greenhouse gases contributing to the global warming potential (GWP) of agro-ecosystems. Evaluating the impact of agriculture on climate requires a capacity to predict the net exchanges of these gases in an integrated manner, as related to pedo-climatic conditions and crop management. The biophysical crop model CERES-EGC is designed to predict the productivity and GWP of agro-ecosystems at the plot-scale. Here we applied a Bayesian calibration to its both sub-models of N2O emissions and CO2 fluxes to deal with parameterization and uncertainty analysis. The N2O emission module of CERES-EGC was calibrated against chamber measurements from 7 arable sites in France and the CO2 flux module was calibrated against eddy-covariance measurements from 3 sites in Europe. Measurements from the various sites were assimilated in the posterior probability density functions for the different parameters, using a Bayesian calibration method based on the Metropolis-Hastings algorithm. The model was subsequently extrapolated to predict CO2 and N2O fluxes over entire crop rotations of 3 European experimental sites of the NitroEurope-IP network. Indirect GHG emissions arising from the production of agricultural inputs and from cropping operations were also added to the final GWP. Such modelling approach makes it possible to test various agronomic management scenarios, in order to design productive agro-ecosystems with low global warming potential. The model would be extrapolated from plot- to regional-scale, with the ultimate goal of generating spatialized GHG inventories. Differentiating the emissions in space would thus make it possible to target critical zones in mitigation scenarios at regional scale.

  7. Markov Chain Monte-Carlo Orbit Computation for Binary Asteroids

    NASA Astrophysics Data System (ADS)

    Oszkiewicz, D.; Hestroffer, D.; Pedro, David C.

    2013-11-01

    We present a novel method of orbit computation for resolved binary asteroids. The method combines the Thiele, Innes, van den Bos method with a Markov chain Monte Carlo technique (MCMC). The classical Thiele-van den Bos method has been commonly used in multiple applications before, including orbits of binary stars and asteroids; conversely this novel method can be used for the analysis of binary stars, and of other gravitationally bound binaries. The method requires a minimum of three observations (observing times and relative positions - Cartesian or polar) made at the same tangent plane - or close enough for enabling a first approximation. Further, the use of the MCMC technique for statistical inversion yields the whole bundle of possible orbits, including the one that is most probable. In this new method, we make use of the Metropolis-Hastings algorithm to sample the parameters of the Thiele-van den Bos method, that is the orbital period (or equivalently the double areal constant) together with three randomly selected observations from the same tangent plane. The observations are sampled within their observational errors (with an assumed distribution) and the orbital period is the only parameter that has to be tuned during the sampling procedure. We run multiple chains to ensure that the parameter phase space is well sampled and that the solutions have converged. After the sampling is completed we perform convergence diagnostics. The main advantage of the novel approach is that the orbital period does not need to be known in advance and the entire region of possible orbital solutions is sampled resulting in a maximum likelihood solution and the confidence regions. We have tested the new method on several known binary asteroids and conclude a good agreement with the results obtained with other methods. The new method has been implemented into the Gaia DPAC data reduction pipeline and can be used to confirm the binary nature of a suspected system, and for deriving

  8. Quantifying Uncertainty in Velocity Models using Bayesian Methods

    NASA Astrophysics Data System (ADS)

    Hobbs, R.; Caiado, C.; Majdański, M.

    2008-12-01

    Quanitifying uncertainty in models derived from observed data is a major issue. Public and political understanding of uncertainty is poor and for industry inadequate assessment of risk costs money. In this talk we will examine the geological structure of the subsurface, however our principal exploration tool, controlled source seismology, gives its data in time. Inversion tools exist to map these data into a depth model but a full exploration of the uncertainty of the model is rarely done because robust strategies do not exist for large non-linear complex systems. There are two principal sources of uncertainty: the first comes from the input data which is noisy and bandlimited; the second, and more sinister, is from the model parameterisation and forward algorithms themselves, which approximate to the physics to make the problem tractable. To address these issues we propose a Bayesian approach. One philosophy is to estimate the uncertainty in a possible model derived using standard inversion tools. During the inversion stage we can use our geological prejudice to derive an acceptable model. Then we use a local random walk using the Metropolis- Hastings algorithm to explore the model space immediately around a possible solution. For models with a limited number of parameters we can use the forward modeling step from the inversion code. However as the number of parameters increase and/or the cost of the forward modeling step becomes significant, we need to use fast emulators to act as proxies so a sufficient number of iterations can be performed on which to base our statistical measures of uncertainty. In this presentation we show examples of uncertainty estimation using both pre- and post-critical seismic data. In particular, we will demonstrate uncertainty introduced by the approximation of the physics by using a tomographic inversion of bandlimited data and show that uncertainty increases as the central frequency of the data decreases. This is consistent with the

  9. Bayesian Atmospheric Radiative Transfer (BART): Model, Statistics Driver, and Application to HD 209458b

    NASA Astrophysics Data System (ADS)

    Cubillos, Patricio; Harrington, Joseph; Blecic, Jasmina; Stemm, Madison M.; Lust, Nate B.; Foster, Andrew S.; Rojo, Patricio M.; Loredo, Thomas J.

    2014-11-01

    Multi-wavelength secondary-eclipse and transit depths probe the thermo-chemical properties of exoplanets. In recent years, several research groups have developed retrieval codes to analyze the existing data and study the prospects of future facilities. However, the scientific community has limited access to these packages. Here we premiere the open-source Bayesian Atmospheric Radiative Transfer (BART) code. We discuss the key aspects of the radiative-transfer algorithm and the statistical package. The radiation code includes line databases for all HITRAN molecules, high-temperature H2O, TiO, and VO, and includes a preprocessor for adding additional line databases without recompiling the radiation code. Collision-induced absorption lines are available for H2-H2 and H2-He. The parameterized thermal and molecular abundance profiles can be modified arbitrarily without recompilation. The generated spectra are integrated over arbitrary bandpasses for comparison to data. BART's statistical package, Multi-core Markov-chain Monte Carlo (MC3), is a general-purpose MCMC module. MC3 implements the Differental-evolution Markov-chain Monte Carlo algorithm (ter Braak 2006, 2009). MC3 converges 20-400 times faster than the usual Metropolis-Hastings MCMC algorithm, and in addition uses the Message Passing Interface (MPI) to parallelize the MCMC chains. We apply the BART retrieval code to the HD 209458b data set to estimate the planet's temperature profile and molecular abundances. This work was supported by NASA Planetary Atmospheres grant NNX12AI69G and NASA Astrophysics Data Analysis Program grant NNX13AF38G. JB holds a NASA Earth and Space Science Fellowship.

  10. Assessment of Flood Disaster Impacts in Cambodia: Implications for Rapid Disaster Response

    NASA Astrophysics Data System (ADS)

    Ahamed, Aakash; Bolten, John; Doyle, Colin

    2016-04-01

    Disaster monitoring systems can provide near real time estimates of population and infrastructure affected by sudden onset natural hazards. This information is useful to decision makers allocating lifesaving resources following disaster events. Floods are the world's most common and devastating disasters (UN, 2004; Doocy et al., 2013), and are particularly frequent and severe in the developing countries of Southeast Asia (Long and Trong, 2001; Jonkman, 2005; Kahn, 2005; Stromberg, 2007; Kirsch et al., 2012). Climate change, a strong regional monsoon, and widespread hydropower construction contribute to a complex and unpredictable regional hydrodynamic regime. As such, there is a critical need for novel techniques to assess flood impacts to population and infrastructure with haste during and following flood events in order to enable governments and agencies to optimize response efforts following disasters. Here, we build on methods to determine regional flood extent in near real time and develop systems that automatically quantify the socioeconomic impacts of flooding in Cambodia. Software developed on cloud based, distributed processing Geographic Information Systems (GIS) is used to demonstrate spatial and numerical estimates of population, households, roadways, schools, hospitals, airports, agriculture and fish catch affected by severe monsoon flooding occurring in the Cambodian portion of Lower Mekong River Basin in 2011. Results show modest agreement with government and agency estimates. Maps and statistics generated from the system are intended to complement on the ground efforts and bridge information gaps to decision makers. The system is open source, flexible, and can be applied to other disasters (e.g. earthquakes, droughts, landslides) in various geographic regions.

  11. Bayesian Estimation of 3D Non-planar Fault Geometry and Slip: An application to the 2011 Megathrust (Mw 9.1) Tohoku-Oki Earthquake

    NASA Astrophysics Data System (ADS)

    Dutta, Rishabh; Jónsson, Sigurjón

    2016-04-01

    Earthquake faults are generally considered planar (or of other simple geometry) in earthquake source parameter estimations. However, simplistic fault geometries likely result in biases in estimated slip distributions and increased fault slip uncertainties. In case of large subduction zone earthquakes, these biases and uncertainties propagate into tsunami waveform modeling and other calculations related to postseismic studies, Coulomb failure stresses, etc. In this research, we parameterize 3D non-planar fault geometry for the 2011 Tohoku-Oki earthquake (Mw 9.1) and estimate these geometrical parameters along with fault slip parameters from onland and offshore GPS using Bayesian inference. This non-planar fault is formed using several 3rd degree polynomials in along-strike (X-Y plane) and along-dip (X-Z plane) directions that are tied together using a triangular mesh. The coefficients of these polynomials constitute the fault geometrical parameters. We use the trench and locations of past seismicity as a priori information to constrain these fault geometrical parameters and the Laplacian to characterize the fault slip smoothness. Hyper-parameters associated to these a priori constraints are estimated empirically and the posterior probability distribution of the model (fault geometry and slip) parameters is sampled using an adaptive Metropolis Hastings algorithm. The across-strike uncertainties in the fault geometry (effectively the local fault location) around high-slip patches increases from 6 km at 10km depth to about 35 km at 50km depth, whereas around low-slip patches the uncertainties are larger (from 7 km to 70 km). Uncertainties in reverse slip are found to be higher at high slip patches than at low slip patches. In addition, there appears to be high correlation between adjacent patches of high slip. Our results demonstrate that we can constrain complex non-planar fault geometry together with fault slip from GPS data using past seismicity as a priori

  12. Anthropogenic sulphur dioxide load over China as observed from different satellite sensors

    NASA Astrophysics Data System (ADS)

    Koukouli, M. E.; Balis, D. S.; van der A, Ronald Johannes; Theys, N.; Hedelt, P.; Richter, A.; Krotkov, N.; Li, C.; Taylor, M.

    2016-11-01

    China, with its rapid economic growth and immense exporting power, has been the focus of many studies during this previous decade quantifying its increasing emissions contribution to the Earth's atmosphere. With a population slowly shifting towards enlarged power and purchasing needs, the ceaseless inauguration of new power plants, smelters, refineries and industrial parks leads infallibly to increases in sulphur dioxide, SO2, emissions. The recent capability of next generation algorithms as well as new space-borne instruments to detect anthropogenic SO2 loads has enabled a fast advancement in this field. In the following work, algorithms providing total SO2 columns over China based on SCIAMACHY/Envisat, OMI/Aura and GOME2/MetopA observations are presented. The need for post-processing and gridding of the SO2 fields is further revealed in this work, following the path of previous publications. Further, it is demonstrated that the usage of appropriate statistical tools permits studying parts of the datasets typically excluded, such as the winter months loads. Focusing on actual point sources, such as megacities and known power plant locations, instead of entire provinces, monthly mean time series have been examined in detail. The sharp decline in SO2 emissions in more than 90%-95% of the locations studied confirms the recent implementation of government desulphurisation legislation; however, locations with increases, even for the previous five years, are also identified. These belong to provinces with emerging economies which are in haste to install power plants and are possibly viewed leniently by the authorities, in favour of growth. The SO2 load seasonality has also been examined in detail with a novel mathematical tool, with 70% of the point sources having a statistically significant annual cycle with highs in winter and lows in summer, following the heating requirements of the Chinese population.

  13. Analysis of Energy Spectrum with Low Photon Counts via Bayesian Posterior Simulation

    NASA Astrophysics Data System (ADS)

    van Dyk, David A.; Protassov, Rostislav; Kashyap, Vinay L.; Siemiginowska, Aneta; Connors, Alanna

    1999-04-01

    Recently Bayesian methods have grown rapidly in popularity in many scientific disciplines as several computationally intensive statistical algorithms have become feasible with modern computer power. In this paper, we demonstrate how we have employed these state-of-the-art techniques (e.g., Gibbs sampler and Metropolis-Hastings) to fit today's high-quality, high resolution astrophysical spectral data. These algorithms are very flexible and can be used to fit models that account for the highly hierarchical structure in the collection of high-quality spectra and thus can keep pace with the accelerating progress of new telescope designs. We explicitly model photon arrivals as a Poisson process and, thus, have no difficulty with high resolution low count X-ray and gamma-ray data. These methods will be useful not only for the soon-to-be-launched Chandra X-ray observatory but also such new generation telescopes as XMM, Constellation X, and GLAST. We also explicitly incorporate the instrument response (e.g. via a response matrix and effective area vector), plus background contamination of the data. In particular, we appropriately model the background as the realization of a second Poisson process, thereby eliminating the need to directly subtract off the background counts and the rather embarrassing problem of negative photon counts. The source energy spectrum is modeled as a mixture of a Generalized Linear Model which accounts for the continuum plus absorption and several (Gaussian) line profiles. Generalized Linear Models are the standard method for incorporating covariate information (as in regression) into non-Gaussian models and are thus an obvious but innovative choice in this setting. Using several examples, we illustrate how Bayesian posterior sampling can be used to compute point (i.e., ``best'') estimates of the various model parameters as well as compute error bars on these estimates and construct statistical tests.

  14. Non-parametric deprojection of surface brightness profiles of galaxies in generalised geometries

    NASA Astrophysics Data System (ADS)

    Chakrabarty, D.

    2010-02-01

    Aims: We present a new Bayesian non-parametric deprojection algorithm DOPING (Deprojection of Observed Photometry using an INverse Gambit), that is designed to extract 3-D luminosity density distributions ρ from observed surface brightness maps I, in generalised geometries, while taking into account changes in intrinsic shape with radius, using a penalised likelihood approach and an Markov Chain Monte Carlo optimiser. Methods: We provide the most likely solution to the integral equation that represents deprojection of the measured I to ρ. In order to keep the solution modular, we choose to express ρ as a function of the line-of-sight (LOS) coordinate z. We calculate the extent of the system along the z-axis, for a given point on the image that lies within an identified isophotal annulus. The extent along the LOS is binned and density is held a constant over each such z-bin. The code begins with a seed density and at the beginning of an iterative step, the trial ρ is updated. Comparison of the projection of the current choice of ρ and the observed I defines the likelihood function (which is supplemented by Laplacian regularisation), the maximal region of which is sought by the optimiser (Metropolis Hastings). Results: The algorithm is successfully tested on a set of test galaxies, the morphology of which ranges from an elliptical galaxy with varying eccentricity to an infinitesimally thin disk galaxy marked by an abruptly varying eccentricity profile. Applications are made to faint dwarf elliptical galaxy Ic 3019 and another dwarf elliptical that is characterised by a central spheroidal nuclear component superimposed upon a more extended flattened component. The result of deprojection of the X-ray image of cluster A1413 - assumed triaxial - the axial ratios and inclination of which are taken from the literature, is also presented.

  15. Extracting and Applying SV-SV Shear Modes from Vertical Vibrator Data Across Geothermal Prospects Final Report

    SciTech Connect

    Hardage, Bob

    2013-07-01

    This 3-year project was terminated at the end of Year 1 because the DOE Geothermal project-evaluation committee decided one Milestone was not met and also concluded that our technology would not be successful. The Review Panel recommended a ?no-go? decision be implemented by DOE. The Principal Investigator and his research team disagreed with the conclusions reached by the DOE evaluation committee and wrote a scientifically based rebuttal to the erroneous claims made by the evaluators. We were not told if our arguments were presented to the people who evaluated our work and made the ?no-go? decision. Whatever the case regarding the information we supplied in rebuttal, we received an official letter from Laura Merrick, Contracting Officer at the Golden Field Office, dated June 11, 2013 in which we were informed that project funding would cease and instructed us to prepare a final report before September 5, 2013. In spite of the rebuttal arguments we presented to DOE, this official letter repeated the conclusions of the Review Panel that we had already proven to be incorrect. This is the final report that we are expected to deliver. The theme of this report will be another rebuttal of the technical deficiencies claimed by the DOE Geothermal Review Panel about the value and accomplishments of the work we did in Phase 1 of the project. The material in this report will present images made from direct-S modes produced by vertical-force sources using the software and research findings we developed in Phase 1 that the DOE Review Panel said would not be successful. We made these images in great haste when we were informed that DOE Geothermal rejected our rebuttal arguments and still regarded our technical work to be substandard. We thought it was more important to respond quickly rather than to take additional time to create better quality images than what we present in this Final Report.

  16. An Introduction to Thinking about Trustworthy Research into the Genetics of Intelligence.

    PubMed

    Parens, Erik; Appelbaum, Paul S

    2015-01-01

    The advent of new technologies has rekindled some hopes that it will be possible to identify genetic variants that will help to explain why individuals are different with respect to complex traits. At least one leader in the development of "whole genome sequencing"-the Chinese company BGI-has been quite public about its commitment to using the technique to investigate the genetics of intelligence in general and high intelligence in particular. Because one needs large samples to detect the small effects associated with small genetic differences in the sequence of those base pairs, to make headway with the new sequencing technologies, one also needs to enlist much larger numbers of study participants than geneticists have enrolled before. In an effort to increase the size of a sample, one team of researchers approached the Center for Talented Youth at Johns Hopkins University. They wanted to gain access to records concerning participants in CTY's ongoing Study of Exceptional Talent, and they wanted to approach those individuals to see if they would be willing to share samples of their DNA. We agreed that CTY's dilemma about whether to give the researchers access to those records raised larger questions about the ethics of research into the genetics of intelligence, and we decided to hold a workshop at The Hastings Center that could examine those questions. Our purpose was to create what, borrowing from Sarah Richardson, we came to call a "transformative conversation" about research into the genetics of general cognitive ability-a conversation that would take a wide and long view and would involve a diverse group of stakeholders, including both people who have been highly critical of the research and people who engage in it. This collection of essays, which grew out of that workshop, is intended to provide an introduction to and exploration of this complex and important area.

  17. Firefighter safety: rampant unsafe practices as documented in mainstream media.

    PubMed

    Kahn, Steven A; Woods, Jason; Sipes, Jan C; Toscano, Nicole; Bell, Derek E

    2014-01-01

    More than 30,000 firefighters are injured on the fireground each year. Literature suggests that injury often occurs when protective gear is not used properly. According to firefighters, failure to correctly wear protective equipment occurs for several reasons: (1) gear not used because of haste, (2) cumbersome gear can sometimes interfere with performance, and (3) cultural factors. The purpose of this study is to quantify improper gear and tactic use in a publicly available, online video repository in order to better understand unsafe firefighting. This was an Institutional Review Board-exempt study of public video records. A search for "fire fighting videos" was conducted at YouTube (www.youtube.com). The first 50 videos that contained volunteer or career firefighters at work fighting fires were selected evaluated for appropriate use of personal protective equipment and for safe behavior. The videos were evaluated by two highly experienced professional firefighters. Of the 50 videos reviewed, 25 (50%) demonstrated violations of firefighting safety principles. Of the unsafe videos, 21 (42%) displayed firefighters improperly using gear, while the other 4 (8%) were related to unsound tactics. The most common problem was failure to wear or properly secure a self-contained breathing apparatus when appropriate (14 videos or 28%). The second most common failure was lack of helmet, hood, or approved gloves (11 videos or 22%). In conclusion, firefighting as documented on YouTube is often unsafe because of failure to properly use personal protective equipment. Half of the videos reviewed contained unsafe practices. With such a shockingly high rate of unsafe firefighting, the profession is in need of additional education and reform. In response to this epidemic, a multidisciplinary educational program has been developed to improve firefighter awareness of gear limitations and burn injury risk. Effectiveness of educational programs should be documented in additional

  18. A spatio-temporal nonparametric Bayesian variable selection model of fMRI data for clustering correlated time courses.

    PubMed

    Zhang, Linlin; Guindani, Michele; Versace, Francesco; Vannucci, Marina

    2014-07-15

    In this paper we present a novel wavelet-based Bayesian nonparametric regression model for the analysis of functional magnetic resonance imaging (fMRI) data. Our goal is to provide a joint analytical framework that allows to detect regions of the brain which exhibit neuronal activity in response to a stimulus and, simultaneously, infer the association, or clustering, of spatially remote voxels that exhibit fMRI time series with similar characteristics. We start by modeling the data with a hemodynamic response function (HRF) with a voxel-dependent shape parameter. We detect regions of the brain activated in response to a given stimulus by using mixture priors with a spike at zero on the coefficients of the regression model. We account for the complex spatial correlation structure of the brain by using a Markov random field (MRF) prior on the parameters guiding the selection of the activated voxels, therefore capturing correlation among nearby voxels. In order to infer association of the voxel time courses, we assume correlated errors, in particular long memory, and exploit the whitening properties of discrete wavelet transforms. Furthermore, we achieve clustering of the voxels by imposing a Dirichlet process (DP) prior on the parameters of the long memory process. For inference, we use Markov Chain Monte Carlo (MCMC) sampling techniques that combine Metropolis-Hastings schemes employed in Bayesian variable selection with sampling algorithms for nonparametric DP models. We explore the performance of the proposed model on simulated data, with both block- and event-related design, and on real fMRI data. PMID:24650600

  19. An Introduction to Thinking about Trustworthy Research into the Genetics of Intelligence.

    PubMed

    Parens, Erik; Appelbaum, Paul S

    2015-01-01

    The advent of new technologies has rekindled some hopes that it will be possible to identify genetic variants that will help to explain why individuals are different with respect to complex traits. At least one leader in the development of "whole genome sequencing"-the Chinese company BGI-has been quite public about its commitment to using the technique to investigate the genetics of intelligence in general and high intelligence in particular. Because one needs large samples to detect the small effects associated with small genetic differences in the sequence of those base pairs, to make headway with the new sequencing technologies, one also needs to enlist much larger numbers of study participants than geneticists have enrolled before. In an effort to increase the size of a sample, one team of researchers approached the Center for Talented Youth at Johns Hopkins University. They wanted to gain access to records concerning participants in CTY's ongoing Study of Exceptional Talent, and they wanted to approach those individuals to see if they would be willing to share samples of their DNA. We agreed that CTY's dilemma about whether to give the researchers access to those records raised larger questions about the ethics of research into the genetics of intelligence, and we decided to hold a workshop at The Hastings Center that could examine those questions. Our purpose was to create what, borrowing from Sarah Richardson, we came to call a "transformative conversation" about research into the genetics of general cognitive ability-a conversation that would take a wide and long view and would involve a diverse group of stakeholders, including both people who have been highly critical of the research and people who engage in it. This collection of essays, which grew out of that workshop, is intended to provide an introduction to and exploration of this complex and important area. PMID:26413943

  20. Probabilistic Graphical Model Representation in Phylogenetics

    PubMed Central

    Höhna, Sebastian; Heath, Tracy A.; Boussau, Bastien; Landis, Michael J.; Ronquist, Fredrik; Huelsenbeck, John P.

    2014-01-01

    Recent years have seen a rapid expansion of the model space explored in statistical phylogenetics, emphasizing the need for new approaches to statistical model representation and software development. Clear communication and representation of the chosen model is crucial for: (i) reproducibility of an analysis, (ii) model development, and (iii) software design. Moreover, a unified, clear and understandable framework for model representation lowers the barrier for beginners and nonspecialists to grasp complex phylogenetic models, including their assumptions and parameter/variable dependencies. Graphical modeling is a unifying framework that has gained in popularity in the statistical literature in recent years. The core idea is to break complex models into conditionally independent distributions. The strength lies in the comprehensibility, flexibility, and adaptability of this formalism, and the large body of computational work based on it. Graphical models are well-suited to teach statistical models, to facilitate communication among phylogeneticists and in the development of generic software for simulation and statistical inference. Here, we provide an introduction to graphical models for phylogeneticists and extend the standard graphical model representation to the realm of phylogenetics. We introduce a new graphical model component, tree plates, to capture the changing structure of the subgraph corresponding to a phylogenetic tree. We describe a range of phylogenetic models using the graphical model framework and introduce modules to simplify the representation of standard components in large and complex models. Phylogenetic model graphs can be readily used in simulation, maximum likelihood inference, and Bayesian inference using, for example, Metropolis–Hastings or Gibbs sampling of the posterior distribution. [Computation; graphical models; inference; modularization; statistical phylogenetics; tree plate.] PMID:24951559

  1. An implementation of differential evolution algorithm for inversion of geoelectrical data

    NASA Astrophysics Data System (ADS)

    Balkaya, Çağlayan

    2013-11-01

    Differential evolution (DE), a population-based evolutionary algorithm (EA) has been implemented to invert self-potential (SP) and vertical electrical sounding (VES) data sets. The algorithm uses three operators including mutation, crossover and selection similar to genetic algorithm (GA). Mutation is the most important operator for the success of DE. Three commonly used mutation strategies including DE/best/1 (strategy 1), DE/rand/1 (strategy 2) and DE/rand-to-best/1 (strategy 3) were applied together with a binomial type crossover. Evolution cycle of DE was realized without boundary constraints. For the test studies performed with SP data, in addition to both noise-free and noisy synthetic data sets two field data sets observed over the sulfide ore body in the Malachite mine (Colorado) and over the ore bodies in the Neem-Ka Thana cooper belt (India) were considered. VES test studies were carried out using synthetically produced resistivity data representing a three-layered earth model and a field data set example from Gökçeada (Turkey), which displays a seawater infiltration problem. Mutation strategies mentioned above were also extensively tested on both synthetic and field data sets in consideration. Of these, strategy 1 was found to be the most effective strategy for the parameter estimation by providing less computational cost together with a good accuracy. The solutions obtained by DE for the synthetic cases of SP were quite consistent with particle swarm optimization (PSO) which is a more widely used population-based optimization algorithm than DE in geophysics. Estimated parameters of SP and VES data were also compared with those obtained from Metropolis-Hastings (M-H) sampling algorithm based on simulated annealing (SA) without cooling to clarify uncertainties in the solutions. Comparison to the M-H algorithm shows that DE performs a fast approximate posterior sampling for the case of low-dimensional inverse geophysical problems.

  2. Fit for high altitude: are hypoxic challenge tests useful?

    PubMed

    Matthys, Heinrich

    2011-01-01

    Altitude travel results in acute variations of barometric pressure, which induce different degrees of hypoxia, changing the gas contents in body tissues and cavities. Non ventilated air containing cavities may induce barotraumas of the lung (pneumothorax), sinuses and middle ear, with pain, vertigo and hearing loss. Commercial air planes keep their cabin pressure at an equivalent altitude of about 2,500 m. This leads to an increased respiratory drive which may also result in symptoms of emotional hyperventilation. In patients with preexisting respiratory pathology due to lung, cardiovascular, pleural, thoracic neuromuscular or obesity-related diseases (i.e. obstructive sleep apnea) an additional hypoxic stress may induce respiratory pump and/or heart failure. Clinical pre-altitude assessment must be disease-specific and it includes spirometry, pulsoximetry, ECG, pulmonary and systemic hypertension assessment. In patients with abnormal values we need, in addition, measurements of hemoglobin, pH, base excess, PaO2, and PaCO2 to evaluate whether O2- and CO2-transport is sufficient.Instead of the hypoxia altitude simulation test (HAST), which is not without danger for patients with respiratory insufficiency, we prefer primarily a hyperoxic challenge. The supplementation of normobaric O2 gives us information on the acute reversibility of the arterial hypoxemia and the reduction of ventilation and pulmonary hypertension, as well as about the efficiency of the additional O2-flow needed during altitude exposure. For difficult judgements the performance of the test in a hypobaric chamber with and without supplemental O2-breathing remains the gold standard. The increasing numbers of drugs to treat acute pulmonary hypertension due to altitude exposure (acetazolamide, dexamethasone, nifedipine, sildenafil) or to other etiologies (anticoagulants, prostanoids, phosphodiesterase-5-inhibitors, endothelin receptor antagonists) including mechanical aids to reduce periodical or

  3. MAP estimators for piecewise continuous inversion

    NASA Astrophysics Data System (ADS)

    Dunlop, M. M.; Stuart, A. M.

    2016-10-01

    We study the inverse problem of estimating a field u a from data comprising a finite set of nonlinear functionals of u a , subject to additive noise; we denote this observed data by y. Our interest is in the reconstruction of piecewise continuous fields u a in which the discontinuity set is described by a finite number of geometric parameters a. Natural applications include groundwater flow and electrical impedance tomography. We take a Bayesian approach, placing a prior distribution on u a and determining the conditional distribution on u a given the data y. It is then natural to study maximum a posterior (MAP) estimators. Recently (Dashti et al 2013 Inverse Problems 29 095017) it has been shown that MAP estimators can be characterised as minimisers of a generalised Onsager-Machlup functional, in the case where the prior measure is a Gaussian random field. We extend this theory to a more general class of prior distributions which allows for piecewise continuous fields. Specifically, the prior field is assumed to be piecewise Gaussian with random interfaces between the different Gaussians defined by a finite number of parameters. We also make connections with recent work on MAP estimators for linear problems and possibly non-Gaussian priors (Helin and Burger 2015 Inverse Problems 31 085009) which employs the notion of Fomin derivative. In showing applicability of our theory we focus on the groundwater flow and EIT models, though the theory holds more generally. Numerical experiments are implemented for the groundwater flow model, demonstrating the feasibility of determining MAP estimators for these piecewise continuous models, but also that the geometric formulation can lead to multiple nearby (local) MAP estimators. We relate these MAP estimators to the behaviour of output from MCMC samples of the posterior, obtained using a state-of-the-art function space Metropolis-Hastings method.

  4. Characterization of leucocin B-Ta11a: a bacteriocin from Leuconostoc carnosum Ta11a isolated from meat.

    PubMed

    Felix, J V; Papathanasopoulos, M A; Smith, A A; von Holy, A; Hastings, J W

    1994-10-01

    Leuconostoc (Lc.) carnosum Ta11a, isolated from vacuum-packaged processed meats, produced a bacteriocin designated leucocin B-Ta11a. The crude bacteriocin was heat stable and sensitive to proteolytic enzymes, but not to catalase, lysozyme, or chloroform. It was active against Listeria monocytogenes and several lactic acid bacteria. Leucocin B-Ta11a was optimally produced at 25 degrees C in MRS broth at an initial pH of 6.0 or 6.5. An 8.9-MDa plasmid in Leuconostoc carnosum Ta11a hybridized to a 36-mer oligonucleotide probe (JF-1) that was homologous to leucocin A-UAL187. A 4.9-kb Sau3A fragment from a partial digest of the 8.9-MDa plasmid was cloned into pUC118. The 8.1-kb recombinant plasmid (pJF8.1) was used for sequencing and revealed the presence of two open reading frames (ORFs). ORF1 codes for a protein of 61 amino acids comprising a 37-amino-acid bacteriocin that was determined to be the leucocin B-Ta11a structural gene by virtue of its homology to leucocin A-UAL 187 (Hastings et al. 1991. J. Bacteriol 173:7491-7500). The 24-amino-acid N-terminal extension, however, differs from that of leucocin A-UAL187 by seven residues. The predicted protein of the ORF2 has 113 amino acids and is identical with the amino acid sequence of the cognate ORF of the leucocin A-UAL 187 operon. PMID:7765496

  5. Redefining the maximum sustainable yield for the Schaefer population model including multiplicative environmental noise.

    PubMed

    Bousquet, Nicolas; Duchesne, Thierry; Rivest, Louis-Paul

    2008-09-01

    The focus of this article is to investigate the biological reference points, such as the maximum sustainable yield (MSY), in a common Schaefer (logistic) surplus production model in the presence of a multiplicative environmental noise. This type of model is used in fisheries stock assessment as a first-hand tool for biomass modelling. Under the assumption that catches are proportional to the biomass, we derive new conditions on the environmental noise distribution such that stationarity exists and extinction is avoided. We then get new explicit results about the stationary behavior of the biomass distribution for a particular specification of the noise, namely the biomass distribution itself and a redefinition of the MSY and related quantities that now depend on the value of the variance of the noise. Consequently, we obtain a more precise vision of how less optimistic the stochastic version of the MSY can be than the traditionally used (deterministic) MSY. In addition, we give empirical conditions on the error variance to approximate our specific noise by a lognormal noise, the latter being more natural and leading to easier inference in this context. These conditions are mild enough to make the explicit results of this paper valid in a number of practical applications. The outcomes of two case-studies about northwest Atlantic haddock [Spencer, P.D., Collie, J.S., 1997. Effect of nonlinear predation rates on rebuilding the Georges Bank haddock (Melanogrammus aeglefinus) stock. Can. J. Fish. Aquat. Sci. 54, 2920-2929] and South Atlantic albacore tuna [Millar, R.B., Meyer, R., 2000. Non-linear state space modelling of fisheries biomass dynamics by using Metropolis-Hastings within-Gibbs sampling. Appl. Stat. 49, 327-342] are used to illustrate the impact of our results in bioeconomic terms.

  6. Towards interpreting nitrate-δ15N records in ice cores in terms of nitrogen oxide sources

    NASA Astrophysics Data System (ADS)

    Hastings, M. G.; Buffen, A. M.

    2011-12-01

    The isotopic composition of nitrate preserved in ice cores offers unique potential for reconstructing past contributions of nitrogen oxides (NOx = NO and NO2) to the atmosphere. Sources of NOx imprint a nitrogen stable isotopic (δ15N) signature, which can be conserved during subsequent oxidation to form nitrate. Major sources of NOx include fossil fuels combustion, biomass burning, microbial processes in soils, and lightning, and thus a quantitative tracer of emissions would help detail connections between the atmosphere, the biosphere, and climate. Unfortunately, the δ15N signatures of most NOx sources are not yet well enough constrained to allow for quantitative partitioning, though new methodology for directly collecting NOx for isotopic analysis is promising (Fibiger and Hastings, A43D-0265, AGU 2010). Still, a growing network of ice core δ15N records may offer insight into source signatures, as different sources are important to different regions of the world. For example, a 300-year ice core record of nitrate-δ15N from Summit, Greenland shows a clear and significant 12% (vs. N2) decrease since the Preindustrial that reflects emissions from fossil fuel combustion and/or soils related to changing agricultural practices in North America and Europe. Over the same time period, Antarctic ice cores show no such trend in δ15N. This would be consistent with previous work suggesting that biomass burning and/or stratospheric intrusion of NOx produced from N2O oxidation are dominant sources for nitrate formation at high southern latitudes. In comparison to the polar records, nitrate in tropical ice cores should represent more significant inputs from lightning, microbial processes in soils, and biomass burning. This may be reflected in new results from a high-elevation site in the Peruvian Andes that shows strong seasonal δ15N cycles of up to 15% (vs. N2). We compare and contrast these records in an effort to evaluate the contribution of NOx sources to nitrate over

  7. A BAYESIAN HIERARCHICAL SPATIAL MODEL FOR DENTAL CARIES ASSESSMENT USING NON-GAUSSIAN MARKOV RANDOM FIELDS

    PubMed Central

    Jin, Ick Hoon; Yuan, Ying; Bandyopadhyay, Dipankar

    2016-01-01

    Research in dental caries generates data with two levels of hierarchy: that of a tooth overall and that of the different surfaces of the tooth. The outcomes often exhibit spatial referencing among neighboring teeth and surfaces, i.e., the disease status of a tooth or surface might be influenced by the status of a set of proximal teeth/surfaces. Assessments of dental caries (tooth decay) at the tooth level yield binary outcomes indicating the presence/absence of teeth, and trinary outcomes at the surface level indicating healthy, decayed, or filled surfaces. The presence of these mixed discrete responses complicates the data analysis under a unified framework. To mitigate complications, we develop a Bayesian two-level hierarchical model under suitable (spatial) Markov random field assumptions that accommodates the natural hierarchy within the mixed responses. At the first level, we utilize an autologistic model to accommodate the spatial dependence for the tooth-level binary outcomes. For the second level and conditioned on a tooth being non-missing, we utilize a Potts model to accommodate the spatial referencing for the surface-level trinary outcomes. The regression models at both levels were controlled for plausible covariates (risk factors) of caries, and remain connected through shared parameters. To tackle the computational challenges in our Bayesian estimation scheme caused due to the doubly-intractable normalizing constant, we employ a double Metropolis-Hastings sampler. We compare and contrast our model performances to the standard non-spatial (naive) model using a small simulation study, and illustrate via an application to a clinical dataset on dental caries. PMID:27807470

  8. Bayesian network reconstruction using systems genetics data: comparison of MCMC methods.

    PubMed

    Tasaki, Shinya; Sauerwine, Ben; Hoff, Bruce; Toyoshiba, Hiroyoshi; Gaiteri, Chris; Chaibub Neto, Elias

    2015-04-01

    Reconstructing biological networks using high-throughput technologies has the potential to produce condition-specific interactomes. But are these reconstructed networks a reliable source of biological interactions? Do some network inference methods offer dramatically improved performance on certain types of networks? To facilitate the use of network inference methods in systems biology, we report a large-scale simulation study comparing the ability of Markov chain Monte Carlo (MCMC) samplers to reverse engineer Bayesian networks. The MCMC samplers we investigated included foundational and state-of-the-art Metropolis-Hastings and Gibbs sampling approaches, as well as novel samplers we have designed. To enable a comprehensive comparison, we simulated gene expression and genetics data from known network structures under a range of biologically plausible scenarios. We examine the overall quality of network inference via different methods, as well as how their performance is affected by network characteristics. Our simulations reveal that network size, edge density, and strength of gene-to-gene signaling are major parameters that differentiate the performance of various samplers. Specifically, more recent samplers including our novel methods outperform traditional samplers for highly interconnected large networks with strong gene-to-gene signaling. Our newly developed samplers show comparable or superior performance to the top existing methods. Moreover, this performance gain is strongest in networks with biologically oriented topology, which indicates that our novel samplers are suitable for inferring biological networks. The performance of MCMC samplers in this simulation framework can guide the choice of methods for network reconstruction using systems genetics data. PMID:25631319

  9. Segmentation of polycystic kidneys from MR images

    NASA Astrophysics Data System (ADS)

    Racimora, Dimitri; Vivier, Pierre-Hugues; Chandarana, Hersh; Rusinek, Henry

    2010-03-01

    Polycystic kidney disease (PKD) is a disorder characterized by the growth of numerous fluid filled cysts in the kidneys. Measuring cystic kidney volume is thus crucial to monitoring the evolution of the disease. While T2-weighted MRI delineates the organ, automatic segmentation is very difficult due to highly variable shape and image contrast. The interactive stereology methods used currently involve a compromise between segmentation accuracy and time. We have investigated semi-automated methods: active contours and a sub-voxel morphology based algorithm. Coronal T2- weighted images of 17 patients were acquired in four breath-holds using the HASTE sequence on a 1.5 Tesla MRI unit. The segmentation results were compared to ground truth kidney masks obtained as a consensus of experts. Automatic active contour algorithm yielded an average 22% +/- 8.6% volume error. A recently developed method (Bridge Burner) based on thresholding and constrained morphology failed to separate PKD from the spleen, yielding 37.4% +/- 8.7% volume error. Manual post-editing reduced the volume error to 3.2% +/- 0.8% for active contours and 3.2% +/- 0.6% for Bridge Burner. The total time (automated algorithm plus editing) was 15 min +/- 5 min for active contours and 19 min +/- 11 min for Bridge Burner. The average volume errors for stereology method were 5.9%, 6.2%, 5.4% for mesh size 6.6, 11, 16.5 mm. The average processing times were 17, 7, 4 min. These results show that nearly two-fold improvement in PKD segmentation accuracy over stereology technique can be achieved with a combination of active contours and postediting.

  10. Uncertainty in dual permeability model parameters for structured soils.

    PubMed

    Arora, B; Mohanty, B P; McGuire, J T

    2012-01-01

    Successful application of dual permeability models (DPM) to predict contaminant transport is contingent upon measured or inversely estimated soil hydraulic and solute transport parameters. The difficulty in unique identification of parameters for the additional macropore- and matrix-macropore interface regions, and knowledge about requisite experimental data for DPM has not been resolved to date. Therefore, this study quantifies uncertainty in dual permeability model parameters of experimental soil columns with different macropore distributions (single macropore, and low- and high-density multiple macropores). Uncertainty evaluation is conducted using adaptive Markov chain Monte Carlo (AMCMC) and conventional Metropolis-Hastings (MH) algorithms while assuming 10 out of 17 parameters to be uncertain or random. Results indicate that AMCMC resolves parameter correlations and exhibits fast convergence for all DPM parameters while MH displays large posterior correlations for various parameters. This study demonstrates that the choice of parameter sampling algorithms is paramount in obtaining unique DPM parameters when information on covariance structure is lacking, or else additional information on parameter correlations must be supplied to resolve the problem of equifinality of DPM parameters. This study also highlights the placement and significance of matrix-macropore interface in flow experiments of soil columns with different macropore densities. Histograms for certain soil hydraulic parameters display tri-modal characteristics implying that macropores are drained first followed by the interface region and then by pores of the matrix domain in drainage experiments. Results indicate that hydraulic properties and behavior of the matrix-macropore interface is not only a function of saturated hydraulic conductivity of the macroporematrix interface (Ksa ) and macropore tortuosity (lf ) but also of other parameters of the matrix and macropore domains.

  11. DWI/ADC in Differentiation of Benign from Malignant Focal Liver Lesion

    PubMed Central

    Jahic, Elma; Sofic, Amela; Selimovic, Azra Husic

    2016-01-01

    Material and methods: The study was of prospective-retrospective character. It was carried out at the AKH in Vienna (Austria), where 100 patients with focal liver lesions were included in the study. All patients underwent the routine MR sequences on appliances 1,5 and 3T (Siemens, Germany): T1, T2, HASTE, VIBE, and a DWI with three b values (b 50, b 300 b 600 s / mm2) and ADC map with ROI (regions of interest). The numerical value of ADC map was calculated, where n = 100 liver lesions, by two independent radiologists. Results: On the basis of matching the PH finding statistically we get DWI accuracy of 96.8% for the assessment of liver lesions. The average numerical value of ADC in benign hepatic lesions (FNH, Hemangiomas) in our study amounted to 1.88 (1.326 to 2.48) x103 mm2 /s, while the value of malignant liver lesions (HCC, CCC, CRCLM) were significantly lower and amounted to 1.15 (1.024 to 1.343) x10-3 mm2 /s (Figure 2). Differences between the mean ADC of benign and malignant lesions showed a statistically significant difference with p <0.0005. In our research, we get cut-off for the ADC value of 1,341x10-3 mm2 /s, which proved to be the optimal parameter for differentiation between benign and malignant lesions. Conclusion: Measuring ADC values with DWI as an additional MRI tool can help in oncological practice by distinguishing normal liver parenchyma from focal lesions, and in differentiating benign from malignant liver lesions, particularly in cases where administration of contrast is not possible. PMID:27708485

  12. A methodology to determine boundary conditions from forced convection experiments using liquid crystal thermography

    NASA Astrophysics Data System (ADS)

    Jakkareddy, Pradeep S.; Balaji, C.

    2016-05-01

    This paper reports the results of an experimental study to estimate the heat flux and convective heat transfer coefficient using liquid crystal thermography and Bayesian inference in a heat generating sphere, enclosed in a cubical Teflon block. The geometry considered for the experiments comprises a heater inserted in a hollow hemispherical aluminium ball, resulting in a volumetric heat generation source that is placed at the center of the Teflon block. Calibrated thermochromic liquid crystal sheets are used to capture the temperature distribution at the front face of the Teflon block. The forward model is the three dimensional conduction equation which is solved within the Teflon block to obtain steady state temperatures, using COMSOL. Match up experiments are carried out for various velocities by minimizing the residual between TLC and simulated temperatures for every assumed loss coefficient, to obtain a correlation of average Nusselt number against Reynolds number. This is used for prescribing the boundary condition for the solution to the forward model. A surrogate model obtained by artificial neural network built upon the data from COMSOL simulations is used to drive a Markov Chain Monte Carlo based Metropolis Hastings algorithm to generate the samples. Bayesian inference is adopted to solve the inverse problem for determination of heat flux and heat transfer coefficient from the measured temperature field. Point estimates of the posterior like the mean, maximum a posteriori and standard deviation of the retrieved heat flux and convective heat transfer coefficient are reported. Additionally the effect of number of samples on the performance of the estimation process has been investigated.

  13. Emulation of MIROC5 with a simple climate model

    NASA Astrophysics Data System (ADS)

    Ishizaki, Yasuhiro; Emori, Seita; Shiogama, Hideo; Takahashi, Kiyoshi; Yokohata, Tokuta; Yoshimori, Masakazu

    2014-05-01

    We developed a simple climate model based on MAGICC6, and investigated the ability of the simple climate model to emulate global mean surface air temperature (SAT) changes of an atmosphere-ocean general circulation model (MIROC5) in the twenty-first century in representative concentration pathways (RCPs). Some previous research indicated that climate sensitivity, ocean vertical diffusion and forcing of anthropogenic aerosols (direct and indirect effects of sulfate aerosol, black carbon and organic carbon) are important factors to emulate global mean SAT changes of atmosphere-ocean general circulation models CMIP3. We therefore estimate these important parameters in the simple climate model using a Metropolis-Hastings Markov chain Monte Carlo (MCMC) approach. The estimated values of the important parameters by the MCMC are physically valid, and our simple climate model can successfully emulate global mean SAT changes of MIROC5 in RCPs with the estimated parameters by the MCMC approach. In addition, we estimated the relative contributions f each important parameter in sensitivity experiments, in which we change the value of an important parameter from the estimated one by the MCMC to the default value of MAGICC6. As a result, we found that the estimation of climate sensitivity is the most important factor for the emulation of the AOGCM, and the stimation of ocean vertical diffusion is also important factor. Although the estimations of the anthropogenic aerosols forcing are very important for the emulation of the AOGCM in the twenty century, the influence of them on the emulation of the AOGCM in the twenty first century is very small. This is because emissions of anthropogenic aerosols are projected to decrease in the twenty first century, and relative contributions of the forcing of anthropogenic aerosols also decrease. Carbon cycle models are not incorporated into our simple climate model yet. A sophisticated carbon cycle model is required to be incorporated into

  14. Cosmological Parameters from CMB Maps without Likelihood Approximation

    NASA Astrophysics Data System (ADS)

    Racine, B.; Jewell, J. B.; Eriksen, H. K.; Wehus, I. K.

    2016-03-01

    We propose an efficient Bayesian Markov chain Monte Carlo (MCMC) algorithm for estimating cosmological parameters from cosmic microwave background (CMB) data without the use of likelihood approximations. It builds on a previously developed Gibbs sampling framework that allows for exploration of the joint CMB sky signal and power spectrum posterior, P({\\boldsymbol{s}},{C}{\\ell }| {\\boldsymbol{d}}), and addresses a long-standing problem of efficient parameter estimation simultaneously in regimes of high and low signal-to-noise ratio. To achieve this, our new algorithm introduces a joint Markov chain move in which both the signal map and power spectrum are synchronously modified, by rescaling the map according to the proposed power spectrum before evaluating the Metropolis-Hastings accept probability. Such a move was already introduced by Jewell et al., who used it to explore low signal-to-noise posteriors. However, they also found that the same algorithm is inefficient in the high signal-to-noise regime, since a brute-force rescaling operation does not account for phase information. This problem is mitigated in the new algorithm by subtracting the Wiener filter mean field from the proposed map prior to rescaling, leaving high signal-to-noise information invariant in the joint step, and effectively only rescaling the low signal-to-noise component. To explore the full posterior, the new joint move is then interleaved with a standard conditional Gibbs move for the sky map. We apply our new algorithm to simplified simulations for which we can evaluate the exact posterior to study both its accuracy and its performance, and find good agreement with the exact posterior; marginal means agree to ≲0.006σ and standard deviations to better than ˜3%. The Markov chain correlation length is of the same order of magnitude as those obtained by other standard samplers in the field.

  15. Non-linearity in Bayesian 1-D magnetotelluric inversion

    NASA Astrophysics Data System (ADS)

    Guo, Rongwen; Dosso, Stan E.; Liu, Jianxin; Dettmer, Jan; Tong, Xiaozhong

    2011-05-01

    This paper applies a Bayesian approach to examine non-linearity for the 1-D magnetotelluric (MT) inverse problem. In a Bayesian formulation the posterior probability density (PPD), which combines data and prior information, is interpreted in terms of parameter estimates and uncertainties, which requires optimizing and integrating the PPD. Much work on 1-D MT inversion has been based on (approximate) linearized solutions, but more recently fully non-linear (numerical) approaches have been applied. This paper directly compares results of linearized and non-linear uncertainty estimation for 1-D MT inversion; to do so, advanced methods for both approaches are applied. In the non-linear formulation used here, numerical optimization is carried out using an adaptive-hybrid algorithm. Numerical integration applies Metropolis-Hastings sampling, rotated to a principal-component parameter space for efficient sampling of correlated parameters, and employing non-unity sampling temperatures to ensure global sampling. Since appropriate model parametrizations are generally not known a priori, both under- and overparametrized approaches are considered. For underparametrization, the Bayesian information criterion is applied to determine the number of layers consistent with the resolving power of the data. For overparametrization, prior information is included which favours simple structure in a manner similar to regularized inversion. The data variance and/or trade-off parameter regulating data and prior information are treated in several ways, including applying fixed optimal estimates (an empirical Bayesian approach) or including them as hyperparameters in the sampling (hierarchical Bayesian). The latter approach has the benefit of accounting for the uncertainty in the hyperparameters in estimating model parameter uncertainties. Non-linear and linearized inversion results are compared for synthetic test cases and for the measured COPROD1 MT data by considering marginal probability

  16. Firefighter safety: rampant unsafe practices as documented in mainstream media.

    PubMed

    Kahn, Steven A; Woods, Jason; Sipes, Jan C; Toscano, Nicole; Bell, Derek E

    2014-01-01

    More than 30,000 firefighters are injured on the fireground each year. Literature suggests that injury often occurs when protective gear is not used properly. According to firefighters, failure to correctly wear protective equipment occurs for several reasons: (1) gear not used because of haste, (2) cumbersome gear can sometimes interfere with performance, and (3) cultural factors. The purpose of this study is to quantify improper gear and tactic use in a publicly available, online video repository in order to better understand unsafe firefighting. This was an Institutional Review Board-exempt study of public video records. A search for "fire fighting videos" was conducted at YouTube (www.youtube.com). The first 50 videos that contained volunteer or career firefighters at work fighting fires were selected evaluated for appropriate use of personal protective equipment and for safe behavior. The videos were evaluated by two highly experienced professional firefighters. Of the 50 videos reviewed, 25 (50%) demonstrated violations of firefighting safety principles. Of the unsafe videos, 21 (42%) displayed firefighters improperly using gear, while the other 4 (8%) were related to unsound tactics. The most common problem was failure to wear or properly secure a self-contained breathing apparatus when appropriate (14 videos or 28%). The second most common failure was lack of helmet, hood, or approved gloves (11 videos or 22%). In conclusion, firefighting as documented on YouTube is often unsafe because of failure to properly use personal protective equipment. Half of the videos reviewed contained unsafe practices. With such a shockingly high rate of unsafe firefighting, the profession is in need of additional education and reform. In response to this epidemic, a multidisciplinary educational program has been developed to improve firefighter awareness of gear limitations and burn injury risk. Effectiveness of educational programs should be documented in additional

  17. Bayesian inversion of marine controlled source electromagnetic data offshore Vancouver Island, Canada

    NASA Astrophysics Data System (ADS)

    Gehrmann, Romina A. S.; Schwalenberg, Katrin; Riedel, Michael; Spence, George D.; Spieß, Volkhard; Dosso, Stan E.

    2016-01-01

    This paper applies nonlinear Bayesian inversion to marine controlled source electromagnetic (CSEM) data collected near two sites of the Integrated Ocean Drilling Program (IODP) Expedition 311 on the northern Cascadia Margin to investigate subseafloor resistivity structure related to gas hydrate deposits and cold vents. The Cascadia margin, off the west coast of Vancouver Island, Canada, has a large accretionary prism where sediments are under pressure due to convergent plate boundary tectonics. Gas hydrate deposits and cold vent structures have previously been investigated by various geophysical methods and seabed drilling. Here, we invert time-domain CSEM data collected at Sites U1328 and U1329 of IODP Expedition 311 using Bayesian methods to derive subsurface resistivity model parameters and uncertainties. The Bayesian information criterion is applied to determine the amount of structure (number of layers in a depth-dependent model) that can be resolved by the data. The parameter space is sampled with the Metropolis-Hastings algorithm in principal-component space, utilizing parallel tempering to ensure wider and efficient sampling and convergence. Nonlinear inversion allows analysis of uncertain acquisition parameters such as time delays between receiver and transmitter clocks as well as input electrical current amplitude. Marginalizing over these instrument parameters in the inversion accounts for their contribution to the geophysical model uncertainties. One-dimensional inversion of time-domain CSEM data collected at measurement sites along a survey line allows interpretation of the subsurface resistivity structure. The data sets can be generally explained by models with 1 to 3 layers. Inversion results at U1329, at the landward edge of the gas hydrate stability zone, indicate a sediment unconformity as well as potential cold vents which were previously unknown. The resistivities generally increase upslope due to sediment erosion along the slope. Inversion

  18. Fit for high altitude: are hypoxic challenge tests useful?

    PubMed Central

    2011-01-01

    Altitude travel results in acute variations of barometric pressure, which induce different degrees of hypoxia, changing the gas contents in body tissues and cavities. Non ventilated air containing cavities may induce barotraumas of the lung (pneumothorax), sinuses and middle ear, with pain, vertigo and hearing loss. Commercial air planes keep their cabin pressure at an equivalent altitude of about 2,500 m. This leads to an increased respiratory drive which may also result in symptoms of emotional hyperventilation. In patients with preexisting respiratory pathology due to lung, cardiovascular, pleural, thoracic neuromuscular or obesity-related diseases (i.e. obstructive sleep apnea) an additional hypoxic stress may induce respiratory pump and/or heart failure. Clinical pre-altitude assessment must be disease-specific and it includes spirometry, pulsoximetry, ECG, pulmonary and systemic hypertension assessment. In patients with abnormal values we need, in addition, measurements of hemoglobin, pH, base excess, PaO2, and PaCO2 to evaluate whether O2- and CO2-transport is sufficient. Instead of the hypoxia altitude simulation test (HAST), which is not without danger for patients with respiratory insufficiency, we prefer primarily a hyperoxic challenge. The supplementation of normobaric O2 gives us information on the acute reversibility of the arterial hypoxemia and the reduction of ventilation and pulmonary hypertension, as well as about the efficiency of the additional O2-flow needed during altitude exposure. For difficult judgements the performance of the test in a hypobaric chamber with and without supplemental O2-breathing remains the gold standard. The increasing numbers of drugs to treat acute pulmonary hypertension due to altitude exposure (acetazolamide, dexamethasone, nifedipine, sildenafil) or to other etiologies (anticoagulants, prostanoids, phosphodiesterase-5-inhibitors, endothelin receptor antagonists) including mechanical aids to reduce periodical or

  19. Nest-site selection in the acorn woodpecker

    USGS Publications Warehouse

    Hooge, P.N.; Stanback, M.T.; Koenig, W.D.

    1999-01-01

    Acorn Woodpeckers (Melanerpes formicivorus) at Hastings Reservation in central California prefer to nest in dead limbs in large, dead valley oaks (Quercus lobata) and California sycamores (Platanus racemosa) that are also frequently used as acorn storage trees. Based on 232 nest cavities used over an 18-year period, we tested whether preferred or modal nest-site characters were associated with increased reproductive success (the 'nest-site quality' hypothesis). We also examined whether more successful nests were likely to experience more favorable microclimatic conditions or to be less accessible to terrestrial predators. We found only equivocal support for the nest-site quality hypothesis: only 1 of 5 preferred characters and 2 of 10 characters exhibiting a clear modality were correlated with higher reproductive success. All three characteristics of nests known or likely to be associated with a more favorable microclimate, and two of five characteristics likely to render nests less accessible to predators, were correlated with higher reproductive success: These results suggest that nest cavities in this population are built in part to take advantage of favorable microclimatic conditions and, to a lesser extent, to reduce access to predators. However, despite benefits of particular nest characteristics, birds frequently nested in apparently suboptimal cavities. We also found a significant relationship between mean group size and the history of occupancy of particular territories and the probability of nest cavities being built in microclimatically favorable live limbs, suggesting that larger groups residing on more stable territories were better able to construct nests with optimal characteristics. This indicates that there may be demographic, as well as ecological, constraints on nest-site selection in this primary cavity nester.

  20. Bayesian Network Reconstruction Using Systems Genetics Data: Comparison of MCMC Methods

    PubMed Central

    Tasaki, Shinya; Sauerwine, Ben; Hoff, Bruce; Toyoshiba, Hiroyoshi; Gaiteri, Chris; Chaibub Neto, Elias

    2015-01-01

    Reconstructing biological networks using high-throughput technologies has the potential to produce condition-specific interactomes. But are these reconstructed networks a reliable source of biological interactions? Do some network inference methods offer dramatically improved performance on certain types of networks? To facilitate the use of network inference methods in systems biology, we report a large-scale simulation study comparing the ability of Markov chain Monte Carlo (MCMC) samplers to reverse engineer Bayesian networks. The MCMC samplers we investigated included foundational and state-of-the-art Metropolis–Hastings and Gibbs sampling approaches, as well as novel samplers we have designed. To enable a comprehensive comparison, we simulated gene expression and genetics data from known network structures under a range of biologically plausible scenarios. We examine the overall quality of network inference via different methods, as well as how their performance is affected by network characteristics. Our simulations reveal that network size, edge density, and strength of gene-to-gene signaling are major parameters that differentiate the performance of various samplers. Specifically, more recent samplers including our novel methods outperform traditional samplers for highly interconnected large networks with strong gene-to-gene signaling. Our newly developed samplers show comparable or superior performance to the top existing methods. Moreover, this performance gain is strongest in networks with biologically oriented topology, which indicates that our novel samplers are suitable for inferring biological networks. The performance of MCMC samplers in this simulation framework can guide the choice of methods for network reconstruction using systems genetics data. PMID:25631319

  1. Bayesian Semi-parametric Analysis of Semi-competing Risks Data: Investigating Hospital Readmission after a Pancreatic Cancer Diagnosis

    PubMed Central

    Lee, Kyu Ha; Haneuse, Sebastien; Schrag, Deborah; Dominici, Francesca

    2014-01-01

    Summary In the U.S., the Centers for Medicare and Medicaid Services uses 30-day readmission, following hospitalization, as a proxy outcome to monitor quality of care. These efforts generally focus on treatable health conditions, such as pneumonia and heart failure. Expanding quality of care systems to monitor conditions for which treatment options are limited or non-existent, such as pancreatic cancer, is challenging because of the non-trivial force of mortality; 30-day mortality for pancreatic cancer is approximately 30%. In the statistical literature, data that arise when the observation of the time to some non-terminal event is subject to some terminal event are referred to as ‘semi-competing risks data’. Given such data, scientific interest may lie in at least one of three areas: (i) estimation/inference for regression parameters, (ii) characterization of dependence between the two events, and (iii) prediction given a covariate profile. Existing statistical methods focus almost exclusively on the first of these; methods are sparse or non-existent, however, when interest lies with understanding dependence and performing prediction. In this paper we propose a Bayesian semi-parametric regression framework for analyzing semi-competing risks data that permits the simultaneous investigation of all three of the aforementioned scientific goals. Characterization of the induced posterior and posterior predictive distributions is achieved via an efficient Metropolis-Hastings-Green algorithm, which has been implemented in an R package. The proposed framework is applied to data on 16,051 individuals diagnosed with pancreatic cancer between 2005-2008, obtained from Medicare Part A. We found that increased risk for readmission is associated with a high comorbidity index, a long hospital stay at initial hospitalization, non-white race, male, and discharge to home care. PMID:25977592

  2. Integration of climate change in flood prediction: application to the Somme river (France)

    NASA Astrophysics Data System (ADS)

    Pinault, J.-L.; Amraoui, N.; Noyer, M.-L.

    2003-04-01

    Exceptional floods that have occurred for the last two years in western and central Europe were very unlikely. The concomitance of such rare events shows that they might be imputable to climate change. The statistical analysis of long rainfall series confirms that both the cumulated annual height and the temporal variability have increased for the last decade. This paper is devoted to the analysis of climate change impact on flood prediction applied to the Somme river. The exceptional pluviometry that occurred from October 2000 to April 2001, about the double of the mean value, entailed catastrophic flood between the high Somme and Abbeville. The flow reached a peak at the beginning of May 2001, involving damages in numerous habitations and communication routes, and economical activity of the region had been flood-bound for more than 2 months. The flood caught unaware the population and caused deep traumas in France since it was the first time such a sudden event was recognized as resulting from groundwater discharge. Mechanisms of flood generation were studied tightly in order to predict the behavior of the Somme catchment and other urbanized basins when the pluviometry is exceptional in winter or in spring, which occurs more and more frequently in the northern part of Europe. The contribution of groundwater in surface water flow was calculated by inverse modeling from piezometers that are representative of aquifers in valleys. They were found on the slopes and near the edge of plateaus in order to characterize the drainage processes of the watertable to the surface water network. For flood prediction, a stochastic process is used, consisting in the generation of both rainfall and PET time series. The precipitation generator uses Markov chain Monte Carlo and simulated annealing from the Hastings -- Metropolis algorithm. Coupling of rainfall and PET generators with transfer enables a new evaluation of the probability of occurrence of floods, taking into account

  3. Asymptotics for a special solution of the thirty fourth Painlevé equation

    NASA Astrophysics Data System (ADS)

    Its, A. R.; Kuijlaars, A. B. J.; Östensson, J.

    2009-07-01

    In a previous paper we studied the double scaling limit of unitary random matrix ensembles of the form Z_{n,N}^{-1} |\\det M|^{2\\alpha} \\rme^{-N Tr V(M)} \\rmd M with α > -1/2. The factor | det M|2α induces critical eigenvalue behaviour near the origin. Under the assumption that the limiting mean eigenvalue density associated with V is regular, and that the origin is a right endpoint of its support, we computed the limiting eigenvalue correlation kernel in the double scaling limit as n, N → ∞ such that n2/3(n/N - 1) = O(1) by using the Deift-Zhou steepest descent method for the Riemann-Hilbert problem for polynomials on the line orthogonal with respect to the weight |x|2αe-NV(x). Our main attention was on the construction of a local parametrix near the origin by means of the ψ-functions associated with a distinguished solution uα of the Painlevé XXXIV equation. This solution is related to a particular solution of the Painlevé II equation, which, however, is different from the usual Hastings-McLeod solution. In this paper we compute the asymptotic behaviour of uα(s) as s → ±∞. We conjecture that this asymptotics characterizes uα and we present supporting arguments based on the asymptotic analysis of a one-parameter family of solutions of the Painlevé XXXIV equation which includes uα. We identify this family as the family of tronquée solutions of the thirty fourth Painlevé equation.

  4. Extremes of N Vicious Walkers for Large N: Application to the Directed Polymer and KPZ Interfaces

    NASA Astrophysics Data System (ADS)

    Schehr, Grégory

    2012-11-01

    We compute the joint probability density function (jpdf) P N ( M, τ M ) of the maximum M and its position τ M for N non-intersecting Brownian excursions, on the unit time interval, in the large N limit. For N→∞, this jpdf is peaked around M = sqrt{2N} and τ M =1/2, while the typical fluctuations behave for large N like M - sqrt{2N} ∝ s N^{-1/6} and τ M -1/2∝ wN -1/3 where s and w are correlated random variables. One obtains an explicit expression of the limiting jpdf P( s, w) in terms of the Tracy-Widom distribution for the Gaussian Orthogonal Ensemble (GOE) of Random Matrix Theory and a psi-function for the Hastings-McLeod solution to the Painlevé II equation. Our result yields, up to a rescaling of the random variables s and w, an expression for the jpdf of the maximum and its position for the Airy2 process minus a parabola. This latter describes the fluctuations in many different physical systems belonging to the Kardar-Parisi-Zhang (KPZ) universality class in 1+1 dimensions. In particular, the marginal probability density function (pdf) P( w) yields, up to a model dependent length scale, the distribution of the endpoint of the directed polymer in a random medium with one free end, at zero temperature. In the large w limit one shows the asymptotic behavior log P( w)˜- w 3/12.

  5. Application of Markov Chain Monte Carlo Method to Mantle Melting: An Example from REE Abundances in Abyssal Peridotites

    NASA Astrophysics Data System (ADS)

    LIU, B.; Liang, Y.

    2015-12-01

    Markov chain Monte Carlo (MCMC) simulation is a powerful statistical method in solving inverse problems that arise from a wide range of applications, such as nuclear physics, computational biology, financial engineering, among others. In Earth sciences applications of MCMC are primarily in the field of geophysics [1]. The purpose of this study is to introduce MCMC to geochemical inverse problems related to trace element fractionation during concurrent melting, melt transport and melt-rock reaction in the mantle. MCMC method has several advantages over linearized least squares methods in inverting trace element patterns in basalts and mantle rocks. First, MCMC can handle equations that have no explicit analytical solutions which are required by linearized least squares methods for gradient calculation. Second, MCMC converges to global minimum while linearized least squares methods may be stuck at a local minimum or converge slowly due to nonlinearity. Furthermore, MCMC can provide insight into uncertainties of model parameters with non-normal trade-off. We use MCMC to invert for extent of melting, amount of trapped melt, and extent of chemical disequilibrium between the melt and residual solid from REE data in abyssal peridotites from Central Indian Ridge and Mid-Atlantic Ridge. In the first step, we conduct forward calculation of REE evolution with melting models in a reasonable model space. We then build up a chain of melting models according to Metropolis-Hastings algorithm to represent the probability of specific model. We show that chemical disequilibrium is likely to play an important role in fractionating LREE in residual peridotites. In the future, MCMC will be applied to more realistic but also more complicated melting models in which partition coefficients, diffusion coefficients, as well as melting and melt suction rates vary as functions of temperature, pressure and mineral compositions. [1]. Sambridge & Mosegarrd [2002] Rev. Geophys.

  6. Fit for high altitude: are hypoxic challenge tests useful?

    PubMed

    Matthys, Heinrich

    2011-01-01

    Altitude travel results in acute variations of barometric pressure, which induce different degrees of hypoxia, changing the gas contents in body tissues and cavities. Non ventilated air containing cavities may induce barotraumas of the lung (pneumothorax), sinuses and middle ear, with pain, vertigo and hearing loss. Commercial air planes keep their cabin pressure at an equivalent altitude of about 2,500 m. This leads to an increased respiratory drive which may also result in symptoms of emotional hyperventilation. In patients with preexisting respiratory pathology due to lung, cardiovascular, pleural, thoracic neuromuscular or obesity-related diseases (i.e. obstructive sleep apnea) an additional hypoxic stress may induce respiratory pump and/or heart failure. Clinical pre-altitude assessment must be disease-specific and it includes spirometry, pulsoximetry, ECG, pulmonary and systemic hypertension assessment. In patients with abnormal values we need, in addition, measurements of hemoglobin, pH, base excess, PaO2, and PaCO2 to evaluate whether O2- and CO2-transport is sufficient.Instead of the hypoxia altitude simulation test (HAST), which is not without danger for patients with respiratory insufficiency, we prefer primarily a hyperoxic challenge. The supplementation of normobaric O2 gives us information on the acute reversibility of the arterial hypoxemia and the reduction of ventilation and pulmonary hypertension, as well as about the efficiency of the additional O2-flow needed during altitude exposure. For difficult judgements the performance of the test in a hypobaric chamber with and without supplemental O2-breathing remains the gold standard. The increasing numbers of drugs to treat acute pulmonary hypertension due to altitude exposure (acetazolamide, dexamethasone, nifedipine, sildenafil) or to other etiologies (anticoagulants, prostanoids, phosphodiesterase-5-inhibitors, endothelin receptor antagonists) including mechanical aids to reduce periodical or

  7. Changes in the social context and conduct of eating in four Nordic countries between 1997 and 2012.

    PubMed

    Holm, Lotte; Lauridsen, Drude; Lund, Thomas Bøker; Gronow, Jukka; Niva, Mari; Mäkelä, Johanna

    2016-08-01

    How have eating patterns changed in modern life? In public and academic debate concern has been expressed that the social function of eating may be challenged by de-structuration and the dissolution of traditions. We analyzed changes in the social context and conduct of eating in four Nordic countries over the period 1997-2012. We focused on three interlinked processes often claimed to be distinctive of modern eating: delocalization of eating from private households to commercial settings, individualization in the form of more eating alone, and informalization, implying more casual codes of conduct. We based the analysis on data from two surveys conducted in Denmark, Finland, Norway and Sweden in 1997 and 2012. The surveys reported in detail one day of eating in representative samples of adult populations in the four countries (N = 4823 and N = 8242). We compared data regarding where, with whom, and for how long people ate, and whether parallel activities took place while eating. While Nordic people's primary location for eating remained the home and the workplace, the practices of eating in haste, and while watching television increased and using tablets, computers and smartphones while eating was frequent in 2012. Propensity to eat alone increased slightly in Denmark and Norway, and decreased slightly in Sweden. While such practices vary with socio-economic background, regression analysis showed several changes were common across the Nordic populations. However, the new practice of using tablets, computers, and smartphones while eating was strongly associated with young age. Further, each of the practices appeared to be related to different types of meal. We conclude that while the changes in the social organization of eating were not dramatic, signs of individualization and informalization could be detected. PMID:27131417

  8. Cost reduction and manufacture of the SunSine{reg_sign} AC module: Phase I Annual Report : 21 April 1998 -- 31 October 1999

    SciTech Connect

    Kern, E.; Kern, G.

    2000-03-06

    This report summarizes the progress made by Ascension Technology in Phase 1 of the cost reduction and manufacturing improvements of the SunSine{reg_sign} AC Module. This work, conducted under NREL subcontract, is a two-phase effort consisting of investigations into improving inverter packaging, soft switching, circuit optimization, design for manufacturing, manufacturing processes, and pilot production manufacturing. The objective of this subcontract is to significantly reduce the cost of the SunSine{reg_sign} inverter, enhance its performance, and streamline and expand the manufacturing process. During Phase 1, the soft-switching topology was designed, then refined to meet stringent cost and performance goals. This design resulted in improved performance, smaller overall footprint, and reduced costs. The aluminum inverter housing was redesigned, and the decision was made to conformal coat the circuit boards, which was verified through the HAST (Highly Accelerated Stress Testing) method. Potential international markets were identified, and the inverter is designed to be easily modified to meet the requirements of other countries. Significant cost reduction and performance improvements have been achieved in Phase I, and accomplishments during Phase I include: (1) SunSine{reg_sign} AC Module costs have been reduced enough to be able to reduce the suggested list price; (2) successful implementation of soft-switching; (3) power circuit-board size reduced 53{percent}; (4) power circuit-board component count reduced 34{percent}; (5) total inverter parts count reduced 49{percent}; (6) anticipated inverter manufacturing cost reduced 57{percent} on a $/Wp rating; (7) transformer efficiency improved 1.4{percent}; and (8) inverter efficiency improved 4.7{percent} to 91.0{percent} at 275 Wac.

  9. A Spatio-Temporal Nonparametric Bayesian Variable Selection Model of fMRI Data for Clustering Correlated Time Courses

    PubMed Central

    Zhang, Linlin; Guindani, Michele; Versace, Francesco; Vannucci, Marina

    2014-01-01

    In this paper we present a novel wavelet-based Bayesian nonparametric regression model for the analysis of functional magnetic resonance imaging (fMRI) data. Our goal is to provide a joint analytical framework that allows to detect regions of the brain which exhibit neuronal activity in response to a stimulus and, simultaneously, infer the association, or clustering, of spatially remote voxels that exhibit fMRI time series with similar characteristics. We start by modeling the data with an hemodynamic response function (HRF) with a voxel-dependent shape parameter. We detect regions of the brain activated in response to a given stimulus by using mixture priors with a spike at zero on the coefficients of the regression model. We account for the complex spatial correlation structure of the brain by using a Markov Random Field (MRF) prior on the parameters guiding the selection of the activated voxels, therefore capturing correlation among nearby voxels. In order to infer association of the voxel time courses, we assume correlated errors, in particular long memory, and exploit the whitening properties of discrete wavelet transforms. Furthermore, we achieve clustering of the voxels by imposing a Dirichlet Process (DP) prior on the parameters of the long memory process. For inference, we use Markov Chain Monte Carlo (MCMC) sampling techniques that combine Metropolis- Hastings schemes employed in Bayesian variable selection with sampling algorithms for nonparametric DP models. We explore the performance of the proposed model on simulated data, with both block- and event-related design, and on real fMRI data. PMID:24650600

  10. Microbial structures in an Alpine Thermal Spring - Microscopic techniques for the examination of Biofilms in a Subsurface Environment

    NASA Astrophysics Data System (ADS)

    Dornmayr-Pfaffenhuemer, Marion; Pierson, Elisabeth; Janssen, Geert-Jan; Stan-Lotter, Helga

    2010-05-01

    The research into extreme environments hast important implications for biology and other sciences. Many of the organisms found there provide insights into the history of Earth. Life exists in all niches where water is present in liquid form. Isolated environments such as caves and other subsurface locations are of interest for geomicrobiological studies. And because of their "extra-terrestrial" conditions such as darkness and mostly extreme physicochemical state they are also of astrobiological interest. The slightly radioactive thermal spring at Bad Gastein (Austria) was therefore examined for the occurrence of subsurface microbial communities. The surfaces of the submerged rocks in this warm spring were overgrown by microbial mats. Scanning electron microscopy (SEM) performed by the late Dr. Wolfgang Heinen revealed an interesting morphological diversity in biofilms found in this environment (1, 2). Molecular analysis of the community structure of the radioactive subsurface thermal spring was performed by Weidler et al. (3). The growth of these mats was simulated using sterile glass slides which were exposed to the water stream of the spring. Those mats were analysed microscopically. Staining, using fluorescent dyes such as 4',6-Diamidino-2-phenylindol (DAPI), gave an overview of the microbial diversity of these biofilms. Additional SEM samples were prepared using different fixation protocols. Scanning confocal laser microscopy (SCLM) allowed a three dimensional view of the analysed biofilms. This work presents some electron micrographs of Dr. Heinen and additionally new microscopic studies of the biofilms formed on the glass slides. The appearances of the new SEM micrographs were compared to those of Dr. Heinen that were done several years ago. The morphology and small-scale distribution in the microbial mat was analyzed by fluorescence microscopy. The examination of natural biomats and biofilms grown on glass slides using several microscopical techniques

  11. Essentials in the diagnosis of acid-base disorders and their high altitude application.

    PubMed

    Paulev, P E; Zubieta-Calleja, G R

    2005-09-01

    This report describes the historical development in the clinical application of chemical variables for the interpretation of acid-base disturbances. The pH concept was already introduced in 1909. Following World War II, disagreements concerning the definition of acids and bases occurred, and since then two strategies have been competing. Danish scientists in 1923 defined an acid as a substance able to give off a proton at a given pH, and a base as a substance that could bind a proton, whereas the North American Singer-Hasting school in 1948 defined acids as strong non-buffer anions and bases as non-buffer cations. As a consequence of this last definition, electrolyte disturbances were mixed up with real acid-base disorders and the variable, strong ion difference (SID), was introduced as a measure of non-respiratory acid-base disturbances. However, the SID concept is only an empirical approximation. In contrast, the Astrup/Siggaard-Andersen school of scientists, using computer strategies and the Acid-base Chart, has made diagnosis of acid-base disorders possible at a glance on the Chart, when the data are considered in context with the clinical development. Siggaard-Andersen introduced Base Excess (BE) or Standard Base Excess (SBE) in the extracellular fluid volume (ECF), extended to include the red cell volume (eECF), as a measure of metabolic acid-base disturbances and recently replaced it by the term Concentration of Titratable Hydrogen Ion (ctH). These two concepts (SBE and ctH) represent the same concentration difference, but with opposite signs. Three charts modified from the Siggaard-Andersen Acid-Base Chart are presented for use at low, medium and high altitudes of 2500 m, 3500 m, and 4000 m, respectively. In this context, the authors suggest the use of Titratable Hydrogen Ion concentration Difference (THID) in the extended extracellular fluid volume, finding it efficient and better than any other determination of the metabolic component in acid

  12. Estimating methane fluxes at a landscape scale

    NASA Astrophysics Data System (ADS)

    Stockdale, James; MacBean, Natasha

    2010-05-01

    Terrestrial methane fluxes are an important component of peatland carbon budgets. Using a well-studied peatland site in Wales as a case study, we present a variety of approaches to quantifying annual methane fluxes at a landscape scale, with a focus on the comparison between a simple stratification method, an empirical regression-based method and a process-based method. The simplest approach relies on in situ methane flux measurements which, due to the indirect effects on methane flux from the vascular transport mechanism and co-variation with hydrological conditions, were stratified by vegetation type. Aside from this initial classification, an annual landscape flux was produced through a linear scaling model without attempting to consider any physical, chemical or biological processes known to control methane fluxes. The regression-based approach attempted to model fluxes using repeated measurements from across the study site over a 12 months period, together with environmental variables from associated locations. This method classifies the landscape by vegetation in a similar way to the first method and also takes into consideration variables commonly known to influence methane flux such as temperature and water table. However, no direct consideration of methane production or consumption is included in this empirical regression model. In contrast to both the preceding methods, estimates of methane flux using a process-based model were constructed for the same landscape. This method uses the Carnegie-Ames-Stanford Approach (CASA) model (Potter et al., 1993), which has been modified to include a representation of methane dynamics. The model is calibrated with ground-based measurements of net CH4 flux and water table depth using a Metropolis Hastings Markov Chain Monte Carlo approach. Comparison of these approaches shows that, while simple methods of stratification and scaling are computationally inexpensive and quick to perform, they are least successful when

  13. kNN-based multi-spectral MRI brain tissue classification: manual training versus automated atlas-based training

    NASA Astrophysics Data System (ADS)

    Vrooman, Henri A.; Cocosco, Chris A.; Stokking, Rik; Ikram, M. Arfan; Vernooij, Meike W.; Breteler, Monique M.; Niessen, Wiro J.

    2006-03-01

    Conventional k-Nearest-Neighbor (kNN) classification, which has been successfully applied to classify brain tissue, requires laborious training on manually labeled subjects. In this work, the performance of kNN-based segmentation of gray matter (GM), white matter (WM) and cerebrospinal fluid (CSF) using manual training is compared with a new method, in which training is automated using an atlas. From 12 subjects, standard T2 and PD scans and a high-resolution, high-contrast scan (Siemens T1-weighted HASTE sequence with reverse contrast) were used as feature sets. For the conventional kNN method, manual segmentations were used for training, and classifications were evaluated in a leave-one-out study. The performance as a function of the number of samples per tissue, and k was studied. For fully automated training, scans were registered to a probabilistic brain atlas. Initial training samples were randomly selected per tissue based on a threshold on the tissue probability. These initials were processed to keep the most reliable samples. Performance of the method for varying the threshold on the tissue probability method was studied. By measuring the percentage overlap (SI), classification results of both methods were validated. For conventional kNN classification, varying the number of training samples did not result in significant differences, while increasing k gave significantly better results. In the method using automated training, there is an overestimation of GM at the expense of CSF at higher thresholds on the tissue probability maps. The difference between the conventional method (k=45) and the observers was not significantly larger than inter-observer variability for all tissue types. The automated method performed slightly worse and performed equal to the observers for WM, and less for CSF and GM. From these results it can be concluded that conventional kNN classification may replace manual segmentation, and that atlas-based kNN segmentation has strong

  14. Essentials in the diagnosis of acid-base disorders and their high altitude application.

    PubMed

    Paulev, P E; Zubieta-Calleja, G R

    2005-09-01

    This report describes the historical development in the clinical application of chemical variables for the interpretation of acid-base disturbances. The pH concept was already introduced in 1909. Following World War II, disagreements concerning the definition of acids and bases occurred, and since then two strategies have been competing. Danish scientists in 1923 defined an acid as a substance able to give off a proton at a given pH, and a base as a substance that could bind a proton, whereas the North American Singer-Hasting school in 1948 defined acids as strong non-buffer anions and bases as non-buffer cations. As a consequence of this last definition, electrolyte disturbances were mixed up with real acid-base disorders and the variable, strong ion difference (SID), was introduced as a measure of non-respiratory acid-base disturbances. However, the SID concept is only an empirical approximation. In contrast, the Astrup/Siggaard-Andersen school of scientists, using computer strategies and the Acid-base Chart, has made diagnosis of acid-base disorders possible at a glance on the Chart, when the data are considered in context with the clinical development. Siggaard-Andersen introduced Base Excess (BE) or Standard Base Excess (SBE) in the extracellular fluid volume (ECF), extended to include the red cell volume (eECF), as a measure of metabolic acid-base disturbances and recently replaced it by the term Concentration of Titratable Hydrogen Ion (ctH). These two concepts (SBE and ctH) represent the same concentration difference, but with opposite signs. Three charts modified from the Siggaard-Andersen Acid-Base Chart are presented for use at low, medium and high altitudes of 2500 m, 3500 m, and 4000 m, respectively. In this context, the authors suggest the use of Titratable Hydrogen Ion concentration Difference (THID) in the extended extracellular fluid volume, finding it efficient and better than any other determination of the metabolic component in acid

  15. Degradation monitoring using probabilistic inference

    NASA Astrophysics Data System (ADS)

    Alpay, Bulent

    In order to increase safety and improve economy and performance in a nuclear power plant (NPP), the source and extent of component degradations should be identified before failures and breakdowns occur. It is also crucial for the next generation of NPPs, which are designed to have a long core life and high fuel burnup to have a degradation monitoring system in order to keep the reactor in a safe state, to meet the designed reactor core lifetime and to optimize the scheduled maintenance. Model-based methods are based on determining the inconsistencies between the actual and expected behavior of the plant, and use these inconsistencies for detection and diagnostics of degradations. By defining degradation as a random abrupt change from the nominal to a constant degraded state of a component, we employed nonlinear filtering techniques based on state/parameter estimation. We utilized a Bayesian recursive estimation formulation in the sequential probabilistic inference framework and constructed a hidden Markov model to represent a general physical system. By addressing the problem of a filter's inability to estimate an abrupt change, which is called the oblivious filter problem in nonlinear extensions of Kalman filtering, and the sample impoverishment problem in particle filtering, we developed techniques to modify filtering algorithms by utilizing additional data sources to improve the filter's response to this problem. We utilized a reliability degradation database that can be constructed from plant specific operational experience and test and maintenance reports to generate proposal densities for probable degradation modes. These are used in a multiple hypothesis testing algorithm. We then test samples drawn from these proposal densities with the particle filtering estimates based on the Bayesian recursive estimation formulation with the Metropolis Hastings algorithm, which is a well-known Markov chain Monte Carlo method (MCMC). This multiple hypothesis testing

  16. The Time Is Now: Bioethics and LGBT Issues.

    PubMed

    Powell, Tia; Foglia, Mary Beth

    2014-09-01

    Our goal in producing this special issue is to encourage our colleagues to incorporate topics related to LGBT populations into bioethics curricula and scholarship. Bioethics has only rarely examined the ways in which law and medicine have defined, regulated, and often oppressed sexual minorities. This is an error on the part of bioethics. Medicine and law have served in the past as society's enforcement arm toward sexual minorities, in ways that robbed many people of their dignity. We feel that bioethics has an obligation to discuss that history and to help us as a society take responsibility for it. We can address only a small number of topics in this special issue of the Hastings Center Report, and we selected topics we believe will stimulate discourse. Andrew Solomon offers an elegant overview of the challenges that bioethics faces in articulating a solid basis for LGBT rights. Timothy F. Murphy asks whether bioethics still faces issues related to lesbian, gay, and bisexual people, given the deletion of homosexuality as a disease and the progress toward same-sex marriage. Jamie Lindemann Nelson's essay addresses the search for identity for transgender persons and the role of science in that search. Two articles, those by Brendan S. Abel and by Jack Drescher and Jack Pula, take up the complex issue of medical treatment for children who reject their assigned birth gender. Celia B. Fisher and Brian Mustanski address the special challenges of engaging LGBT youth in research, balancing the need for better information about this vulnerable group against the existing restrictions on research involving children. Tia Powell and Edward Stein consider the merits of legal bans on psychotherapies intended to change sexual orientation, particularly in the light of current research on orientation. Mary Beth Foglia and Karen I. Fredricksen-Goldsen highlight health disparities and resilience among LGBT older adults and then discuss the role of nonconscious bias in perpetuating

  17. The Time Is Now: Bioethics and LGBT Issues.

    PubMed

    Powell, Tia; Foglia, Mary Beth

    2014-09-01

    Our goal in producing this special issue is to encourage our colleagues to incorporate topics related to LGBT populations into bioethics curricula and scholarship. Bioethics has only rarely examined the ways in which law and medicine have defined, regulated, and often oppressed sexual minorities. This is an error on the part of bioethics. Medicine and law have served in the past as society's enforcement arm toward sexual minorities, in ways that robbed many people of their dignity. We feel that bioethics has an obligation to discuss that history and to help us as a society take responsibility for it. We can address only a small number of topics in this special issue of the Hastings Center Report, and we selected topics we believe will stimulate discourse. Andrew Solomon offers an elegant overview of the challenges that bioethics faces in articulating a solid basis for LGBT rights. Timothy F. Murphy asks whether bioethics still faces issues related to lesbian, gay, and bisexual people, given the deletion of homosexuality as a disease and the progress toward same-sex marriage. Jamie Lindemann Nelson's essay addresses the search for identity for transgender persons and the role of science in that search. Two articles, those by Brendan S. Abel and by Jack Drescher and Jack Pula, take up the complex issue of medical treatment for children who reject their assigned birth gender. Celia B. Fisher and Brian Mustanski address the special challenges of engaging LGBT youth in research, balancing the need for better information about this vulnerable group against the existing restrictions on research involving children. Tia Powell and Edward Stein consider the merits of legal bans on psychotherapies intended to change sexual orientation, particularly in the light of current research on orientation. Mary Beth Foglia and Karen I. Fredricksen-Goldsen highlight health disparities and resilience among LGBT older adults and then discuss the role of nonconscious bias in perpetuating

  18. Improving carbon model phenology using data assimilation

    NASA Astrophysics Data System (ADS)

    Exrayat, Jean-François; Smallman, T. Luke; Bloom, A. Anthony; Williams, Mathew

    2015-04-01

    Carbon cycle dynamics is significantly impacted by ecosystem phenology, leading to substantial seasonal and inter-annual variation in the global carbon balance. Representing inter-annual variability is key for predicting the response of the terrestrial ecosystem to climate change and disturbance. Existing terrestrial ecosystem models (TEMs) often struggle to accurately simulate observed inter-annual variability. TEMs often use different phenological models based on plant functional type (PFT) assumptions. Moreover, due to a high level of computational overhead in TEMs they are unable to take advantage of globally available datasets to calibrate their models. Here we describe the novel CARbon DAta MOdel fraMework (CARDAMOM) for data assimilation. CARDAMOM is used to calibrate the Data Assimilation Linked Ecosystem Carbon version 2 (DALEC2) model using Bayes' Theorem within a Metropolis Hastings - Markov Chain Monte Carlo (MH-MCMC). CARDAMOM provides a framework which combines knowledge from observations, such as remotely sensed LAI, and heuristic information in the form of Ecological and Dynamical Constraints (EDCs). The EDCs are representative of real world processes and constrain parameter interdependencies and constrain carbon dynamics. We used CARDAMOM to bring together globally spanning datasets of LAI and the DALEC2 and DALEC2-GSI models. These analyses allow us to investigate the sensitivity ecosystem processes to the representation of phenology. DALEC2 uses an analytically solved model of phenology which is invariant between years. In contrast DALEC2-GSI uses a growing season index (GSI) calculated as a function of temperature, vapour pressure deficit (VPD) and photoperiod to calculate bud-burst and leaf senescence, allowing the model to simulate inter-annual variability in response to climate. Neither model makes any PFT assumptions about the phenological controls of a given ecosystem, allowing the data alone to determine the impact of the meteorological

  19. [The analysis of patients with body traumas treated in the Military Medical Academy's Second Clinical Hospital of the Medical University of Lodz].

    PubMed

    Sikorski, Tomasz; Piotrowski, Dariusz; Gaszyński, Wojciech

    2011-01-01

    According to recent WHO reports, body traumas are ranked third with respect of frequency of occurrence right after cardiovascular diseases and tumours, and are considered one of the major medical problems. Trauma is a kind of energy (mechanical, thermal or chemical) affecting the human body. After crossing the threshold of tissue endurance, an injury or damage occurs. A common problem of all the centres that treat traumas is a reliable and comparable assessment of injury severity. Constant improvement of the trauma scores, contributes to increased objectivity of the assessment of injury severity and makes trauma research easier. To a large extent, commonness of the scores enables the exchange of experiences with respect to treating patients after trauma. An ideal scale should be reliable, easy to use, and most of all commonly used, thus enabling the employment of a common "traumatologic" language. In the following research, the test group was comprised of 137 adult patients including 113 men (82%) and 24 women (18%). Most patients were aged from 20 to 60 years, that is, in the productive age. Appropriate trauma treatment results in the reduction of the costs of hospitalisation time of those patients and their recovery. An accident or worse still death of a young person is not only a personal tragedy for the family. It is also a big economic loss for the society which results from "lost years of life" and thus "lost years of work". Quick and appropriate treatment, done in a proper centre with appropriately trained staff and highest quality equipment will allow not only to reduce the victim's suffering and return to their daily life, but also minimise the social costs connected with disability pensions, benefits and compensations. Most injuries happened at work--61% were probably due to haste but most of all not complying with occupational health and safety regulations, which all employees should know and comply with. It involves doctors writing a sick note for the

  20. Bacteriocins: modes of action and potentials in food preservation and control of food poisoning.

    PubMed

    Abee, T; Krockel, L; Hill, C

    1995-12-01

    -negative bacteria possess an additional layer, the so-called outer membrane which is composed of phospholipids, proteins and lipopolysaccharides (LPS), and this membrane is impermeable to most molecules. Nevertheless, the presence of porins in this layer will allow the free diffusion of molecules with a molecular mass below 600 Da. The smallest bacteriocins produced by lactic acid bacteria are approximately 3 kDa and are thus too large to reach their target, the cytoplasmic membrane (Klaenhammer, 1993; Stiles and Hastings, 1991). However, Stevens et al. (1991) and Ray (1993) have demonstrated that Salmonella species and other Gram-negative bacteria become sensitive to nisin after exposure to treatments that change the permeability barrier properties of the outer membrane (see below). This review will focus on the mode of action of lantibiotics (class I) and class II LAB bacteriocins and their potentials in food preservation and control of food poisoning.

  1. The environment of ageing.

    PubMed Central

    Tinker, A

    1997-01-01

    The issue of housing and the wider environment for an ageing population is one where there are many unanswered questions. In this paper a number of key issues are discussed and for each of these the focus is on three aspects. These are the current situation, its reasonableness and what research is needed in order to make decisions about policy and practice. The first three issues relate to the profile of older people themselves and the importance of home to them. The changing profile of older people is not just about an ageing population but also about the growing prominence of those with dementia, women, people from black and ethnic minority groups and one person households, yet little is known about the type of housing which should be provided. Of equal concern is the widening gap between those with a high standard of living (including housing) and those with a low standard of living. The importance of home to older people means that research must focus on how people can be enabled to remain there, and also on the costs, financial and otherwise, to carers and to society. The next three issues relate to the type of housing older people live in and moves in later life. The startling change in the tenure pattern with a growth of owner occupation brings problems as does the decline in social housing. The advantages and disadvantages of the different types of housing--mainstream and specialized--for older people are relatively well known. However the balance between the two needs more research as does that on retirement communities. While it is well known that there are peaks of migration in old age and that moves are often made in haste, little is known about the process of decision making. The final two topics concern links between housing and other aspects of older people's lives. On health more research is needed on temperature, mortality and morbidity, homelessness and accidents and especially on links between services. These topics have implications for planning

  2. Vestibular system paresis due to emergency endovascular catheterization.

    PubMed

    Simoceli, Lucinda; Sguillar, Danilo Anunciatto; Santos, Henrique Mendes Paiva; Caputti, Camilla

    2012-04-01

    Objetivo: O objetivo deste relato de caso é descrever uma causa incomum de vestibulopatia periférica associada à perda auditiva unilateral em paciente idoso pós- cateterismo de urgência.Relato de caso: Paciente do gênero masculino, 82 anos, submetido à correção de aneurisma roto de aorta abdominal, no intra-operatório sofreu infarto agudo do miocárdio necessitando de angioplastia primária. Após alta hospitalar refere queixa de hipoacusia acentuada à direita e vertigem incapacitante, sem sinais neurológicos focais. Ao exame clínico otorrinolaringológico apresentava: Teste de Weber lateralizado para a esquerda, nistagmo espontâneo para a esquerda , marcha oscilante, leve disbasia e ataxia, índex-nariz e diadococinesia normais, Teste de Romberg com oscilação sem queda e Fukuda com desvio lateral para a direita. O exame audiométrico evidenciava anacusia à direita e perda neurossensorial à esquerda em agudos, arreflexia vestibular à direita na prova calórica e, na tomografia computadorizada dos ossos temporais e tronco-encefálico, presença de haste metálica atravessando o osso temporal direito, a partir da veia jugular interna e bulbo jugular, atravessando os canais semicirculares posterior, superior e vestíbulo, projetando-se em lobo temporal. O diagnóstico radiológico foi lesão traumática por guia endovascular metálico durante cateterismo de urgência e a conduta, considerando que o paciente não havia compensado o equilíbrio, foi reabilitação vestibular.Conclusão: Queixas de tontura no paciente idoso devem ser criteriosamente avaliadas diante do seu histórico clínico patológico pois os antecedentes de doenças e tratamentos prévios, em geral, direcionam as hipóteses diagnósticas porém podem trazer alterações inesperadas.

  3. [The analysis of patients with body traumas treated in the Military Medical Academy's Second Clinical Hospital of the Medical University of Lodz].

    PubMed

    Sikorski, Tomasz; Piotrowski, Dariusz; Gaszyński, Wojciech

    2011-01-01

    According to recent WHO reports, body traumas are ranked third with respect of frequency of occurrence right after cardiovascular diseases and tumours, and are considered one of the major medical problems. Trauma is a kind of energy (mechanical, thermal or chemical) affecting the human body. After crossing the threshold of tissue endurance, an injury or damage occurs. A common problem of all the centres that treat traumas is a reliable and comparable assessment of injury severity. Constant improvement of the trauma scores, contributes to increased objectivity of the assessment of injury severity and makes trauma research easier. To a large extent, commonness of the scores enables the exchange of experiences with respect to treating patients after trauma. An ideal scale should be reliable, easy to use, and most of all commonly used, thus enabling the employment of a common "traumatologic" language. In the following research, the test group was comprised of 137 adult patients including 113 men (82%) and 24 women (18%). Most patients were aged from 20 to 60 years, that is, in the productive age. Appropriate trauma treatment results in the reduction of the costs of hospitalisation time of those patients and their recovery. An accident or worse still death of a young person is not only a personal tragedy for the family. It is also a big economic loss for the society which results from "lost years of life" and thus "lost years of work". Quick and appropriate treatment, done in a proper centre with appropriately trained staff and highest quality equipment will allow not only to reduce the victim's suffering and return to their daily life, but also minimise the social costs connected with disability pensions, benefits and compensations. Most injuries happened at work--61% were probably due to haste but most of all not complying with occupational health and safety regulations, which all employees should know and comply with. It involves doctors writing a sick note for the

  4. The role of manganese in promoting multimerization and assembly of human immunodeficiency virus type 1 integrase as a catalytically active complex on immobilized long terminal repeat substrates.

    PubMed Central

    Wolfe, A L; Felock, P J; Hastings, J C; Blau, C U; Hazuda, D J

    1996-01-01

    The integration of a DNA copy of the viral genome into the genome of the host cell is an essential step in the replication of all retroviruses. Integration requires two discrete biochemical reactions; specific processing of each viral long terminal repeat terminus or donor substrate, and a DNA strand transfer step wherein the processed donor substrate is joined to a nonspecific target DNA. Both reactions are catalyzed by a virally encoded enzyme, integrase. A microtiter assay for the strand transfer activity of human immunodeficiency virus type 1 integrase which uses an immobilized oligonucleotide as the donor substrate was previously published (D. J. Hazuda, J. C. Hastings, A. L. Wolfe, and E. A. Emini, Nucleic Acids Res. 22;1121-1122, 1994). We now describe a series of modifications to the method which facilitate study of both the nature and the dynamics of the interaction between integrase and the donor DNA. The enzyme which binds to the immobilized donor is shown to be sufficient to catalyze strand transfer with target DNA substrates added subsequent to assembly; in the absence of the target substrate, the complex was retained on the donor in an enzymatically competent state. Assembly required high concentrations of divalent cation, with optimal activity achieved at 25 mM MnCl2. In contrast, preassembled complexes catalyzed strand transfer equally efficiently in either 1 or 25 mM MnCl2, indicating mechanistically distinct functions for the divalent cation in assembly and catalysis, respectively. Prior incubation of the enzyme in 25 mM MnCl2 was shown to promote the multimerization of integrase in the absence of a DNA substrate and alleviate the requirement for high concentrations of divalent cation during assembly. The superphysiological requirement for MnCl2 may, therefore, reflect an insufficiency for functional self-assembly in vitro. Subunits were observed to exchange during the assembly reaction, suggesting that multimerization can occur either before or

  5. Computational estimation of tricarboxylic acid cycle fluxes using noisy NMR data from cardiac biopsies

    PubMed Central

    2013-01-01

    Background The aerobic energy metabolism of cardiac muscle cells is of major importance for the contractile function of the heart. Because energy metabolism is very heterogeneously distributed in heart tissue, especially during coronary disease, a method to quantify metabolic fluxes in small tissue samples is desirable. Taking tissue biopsies after infusion of substrates labeled with stable carbon isotopes makes this possible in animal experiments. However, the appreciable noise level in NMR spectra of extracted tissue samples makes computational estimation of metabolic fluxes challenging and a good method to define confidence regions was not yet available. Results Here we present a computational analysis method for nuclear magnetic resonance (NMR) measurements of tricarboxylic acid (TCA) cycle metabolites. The method was validated using measurements on extracts of single tissue biopsies taken from porcine heart in vivo. Isotopic enrichment of glutamate was measured by NMR spectroscopy in tissue samples taken at a single time point after the timed infusion of 13C labeled substrates for the TCA cycle. The NMR intensities for glutamate were analyzed with a computational model describing carbon transitions in the TCA cycle and carbon exchange with amino acids. The model dynamics depended on five flux parameters, which were optimized to fit the NMR measurements. To determine confidence regions for the estimated fluxes, we used the Metropolis-Hastings algorithm for Markov chain Monte Carlo (MCMC) sampling to generate extensive ensembles of feasible flux combinations that describe the data within measurement precision limits. To validate our method, we compared myocardial oxygen consumption calculated from the TCA cycle flux with in vivo blood gas measurements for 38 hearts under several experimental conditions, e.g. during coronary artery narrowing. Conclusions Despite the appreciable NMR noise level, the oxygen consumption in the tissue samples, estimated from the NMR

  6. Flow Dynamics and Sediment Entrainment in Natural Turbidity Currents Inferred from Numerical Modeling

    NASA Astrophysics Data System (ADS)

    Traer, M. M.; Hilley, G. E.; Fildani, A.

    2009-12-01

    Submarine turbidity currents derive their momentum from gravity acting upon the density contrast between sediment-laden and clear water, and so unlike fluvial systems, the dynamics of such flows are inextricably linked to the rates at which they deposit and entrain sediment. We have analyzed the sensitivity of the growth and maintenance of turbidity currents to sediment entrainment and deposition using the layer-averaged equations of conservation of fluid and sediment mass, and conservation of momentum and turbulent kinetic energy. Our model results show that the dynamics of turbidity currents are extremely sensitive to the functional form and empirical constants of the relationship between sediment entrainment and friction velocity. Data on the relationship between sediment entrainment and friction velocity for submarine density flows are few and as a result, entrainment formulations are populated with data from sub-aerial flows not driven by the density contrast between clear and turbid water. If we entertain the possibility that sediment entrainment in sub-aerial rivers is different than in dense underflows, flow parameters such as velocity, height, and concentration were found nearly impossible to predict beyond a few hundred meters based on the limited laboratory data available that constrain the sediment entrainment process in turbidity currents. The sensitivity of flow dynamics to the functional relationship between friction velocity and sediment entrainment indicates that independent calibration of a sediment entrainment law in the submarine environment is necessary to realistically predict the dynamics of these flows and the resulting patterns of erosion and deposition. To calibrate such a relationship, we have developed an inverse methodology that utilizes existing submarine channel morphology as a means of constraining the sediment entrainment function parameters. We use a Bayesian Metropolis-Hastings sampler to determine the sediment entrainment

  7. Hilbert problems for the geosciences in the 21st century

    NASA Astrophysics Data System (ADS)

    Ghil, M.

    The scientific problems posed by the Earth's fluid envelope, and its atmosphere, oceans, and the land surface that interacts with them are central to major socio-economic and political concerns as we move into the 21st century. It is natural, therefore, that a certain impatience should prevail in attempting to solve these problems. The point of this review paper is that one should proceed with all diligence, but not excessive haste: "festina lente," as the Romans said two thousand years ago, i.e. "hurry in a measured way." The paper traces the necessary progress through the solutions to the ten problems: 1. What is the coarse-grained structure of low-frequency atmospheric variability, and what is the connection between its episodic and oscillatory description? 2. What can we predict beyond one week, for how long, and by what methods? 3. What are the respective roles of intrinsic ocean variability, coupled ocean-atmosphere modes, and atmospheric forcing in seasonal-to-interannual variability? 4. What are the implications of the answer to the previous problem for climate prediction on this time scale? 5. How does the oceans' thermohaline circulation change on interdecadal and longer time scales, and what is the role of the atmosphere and sea ice in such changes? 6. What is the role of chemical cycles and biological changes in affecting climate on slow time scales, and how are they affected, in turn, by climate variations? 7. Does the answer to the question above give us some trigger points for climate control? 8. What can we learn about these problems from the atmospheres and oceans of other planets and their satellites? 9. Given the answer to the questions so far, what is the role of humans in modifying the climate? 10. Can we achieve enlightened climate control of our planet by the end of the century? A unified framework is proposed to deal with these problems in succession, from the shortest to the longest timescale, i.e. from weeks to centuries and millennia. The

  8. Adding a Second Ku-Band Antenna to the International Space Station

    NASA Technical Reports Server (NTRS)

    DuSold, Chuck; Thacker, Corey; Kwatra, Sundeep

    2011-01-01

    The International Space Station, as originally developed, used the Ku-Band Tracking and Data Relay Satellite System communications link to transmit non-critical data to the ground. Since becoming operational, the use for the link evolved to include additional services that, although also not critical, were deemed to be necessary for the crew. The external Ku-Band Antennas were designed for transport to the ISS in the shuttle cargo bay and thus are not suitable for manifesting on any current cargo vehicle. The original intent was to stow two spare antennas on orbit in a protective container until such time as they were needed to replace a failing unit which is a long and complicated process due to the complexity of the removal and replacement procedure. The Boeing Company proposed manifesting one of those spare antennas in an operable configuration eliminating the need for an Extravehicular Activity (EVA) to correct the first failure and as such minimizing the time to hours rather than weeks required to restore the Ku-Band communications link after failures. After the first failure, an EVA would be scheduled to replace the failed antenna with the stowed spare antenna. Because the hot spare is activated internal to the ISS, the replacement of the failed unit can be done when convenient rather than in haste. This paper describes the methodology used to locate a suitable site to add a new antenna mast to the ISS as well the process followed to fabricate, deliver and install the new interface hardware. Because this was not planned when the ISS was originally designed, structural, power, data and Intermediate Frequency signal connections had to be found for use. With the movement of the P6 solar array element from the initial location in the center zenith location of the ISS to the end of the port side of the truss and concurrent relocation of one string of S-Band communications assets, there were candidate power, data and structural connections available on the Z1 Truss

  9. The environment of ageing.

    PubMed

    Tinker, A

    1997-12-29

    The issue of housing and the wider environment for an ageing population is one where there are many unanswered questions. In this paper a number of key issues are discussed and for each of these the focus is on three aspects. These are the current situation, its reasonableness and what research is needed in order to make decisions about policy and practice. The first three issues relate to the profile of older people themselves and the importance of home to them. The changing profile of older people is not just about an ageing population but also about the growing prominence of those with dementia, women, people from black and ethnic minority groups and one person households, yet little is known about the type of housing which should be provided. Of equal concern is the widening gap between those with a high standard of living (including housing) and those with a low standard of living. The importance of home to older people means that research must focus on how people can be enabled to remain there, and also on the costs, financial and otherwise, to carers and to society. The next three issues relate to the type of housing older people live in and moves in later life. The startling change in the tenure pattern with a growth of owner occupation brings problems as does the decline in social housing. The advantages and disadvantages of the different types of housing--mainstream and specialized--for older people are relatively well known. However the balance between the two needs more research as does that on retirement communities. While it is well known that there are peaks of migration in old age and that moves are often made in haste, little is known about the process of decision making. The final two topics concern links between housing and other aspects of older people's lives. On health more research is needed on temperature, mortality and morbidity, homelessness and accidents and especially on links between services. These topics have implications for planning

  10. Facts, values, and Attention-Deficit Hyperactivity Disorder (ADHD): an update on the controversies

    PubMed Central

    Parens, Erik; Johnston, Josephine

    2009-01-01

    The Hastings Center, a bioethics research institute, is holding a series of 5 workshops to examine the controversies surrounding the use of medication to treat emotional and behavioral disturbances in children. These workshops bring together clinicians, researchers, scholars, and advocates with diverse perspectives and from diverse fields. Our first commentary in CAPMH, which grew out of our first workshop, explained our method and explored the controversies in general. This commentary, which grows out of our second workshop, explains why informed people can disagree about ADHD diagnosis and treatment. Based on what workshop participants said and our understanding of the literature, we make 8 points. (1) The ADHD label is based on the interpretation of a heterogeneous set of symptoms that cause impairment. (2) Because symptoms and impairments are dimensional, there is an inevitable "zone of ambiguity," which reasonable people will interpret differently. (3) Many other variables, from different systems and tools of diagnosis to different parenting styles and expectations, also help explain why behaviors associated with ADHD can be interpreted differently. (4) Because people hold competing views about the proper goals of psychiatry and parenting, some people will be more, and others less, concerned about treating children in the zone of ambiguity. (5) To recognize that nature has written no bright line between impaired and unimpaired children, and that it is the responsibility of humans to choose who should receive a diagnosis, does not diminish the significance of ADHD. (6) Once ADHD is diagnosed, the facts surrounding the most effective treatment are complicated and incomplete; contrary to some popular wisdom, behavioral treatments, alone or in combination with low doses of medication, can be effective in the long-term reduction of core ADHD symptoms and at improving many aspects of overall functioning. (7) Especially when a child occupies the zone of ambiguity

  11. Geochemical and Isotopic Composition of Aerosols in Tucson

    NASA Astrophysics Data System (ADS)

    Riha, K. M.; Michalski, G. M.; Lohse, K. A.; Gallo, E. L.; Brooks, P. D.; Meixner, T.

    2010-12-01

    isotopic analyses have been conducted on these samples using the denitrifier method (Casciotti et al., 2002). Observed elevated δ18O values correspond to atmospheric oxidation processes and varying δ15N are possibly linked to different N sources. These isotopic values will be used as a proxy for deposition in a mass balance mixing model for nitrogen in arid streams. References: Casciotti, K. L., D. M. Sigman, M. G. Hastings, J. K. Böhlke and A. Hilkert, Measurement of the oxygen isotopic composition of nitrate in seawater and freshwater using the denitrifier method, Anal. Chem., 74(19), 4905-4912, 2002. Michalski, G., Z. Scott, M. Kabiling and M. Thiemens, First Measurements and Modeling of Δ17O in Atmospheric Nitrate, Geophys. Res. Lett., 30(16), (1870), 2003.

  12. Online Method for Oxygen Triple Isotope Analyses of Nitrate

    NASA Astrophysics Data System (ADS)

    Kaiser, J.; Hastings, M. G.; Houlton, B.; Roeckmann, T.; Sigman, D. M.

    2004-12-01

    average isotopic composition of hydroxy/peroxy radicals and tropospheric ozone [cf. contribution by Hastings et al. in session H38]. Nitrate isotope measurements in ice core samples offer opportunities for paleoatmospheric studies. The same method can also be used to analyze N2O itself or other oxy compounds of nitrogen that can be converted to nitrate.

  13. Making Space Travel to Jupiter Possible

    NASA Technical Reports Server (NTRS)

    Barker, Samuel P.

    2004-01-01

    into the Nb1Zr causing imbrittlement and possibly major failure. I will be testing the effects of Hast-X on Nb1Zr in a high temperature for 10, 50, 100, and 500 hours. After the samples are run through the heat treatment, strength and chemistry will be tested and reported. My appreciation for the research that goes behind every project has and will continue to grow. By digging through old documents written in the 50's and 60's, scouring through forgotten closets, and learning from those with experience in the refractory metals, I am bound to have an incredible learning experience here at NASA.

  14. The Ground State of a Gross-Pitaevskii Energy with General Potential in the Thomas-Fermi Limit

    NASA Astrophysics Data System (ADS)

    Karali, Georgia; Sourdis, Christos

    2015-08-01

    We study the ground state which minimizes a Gross-Pitaevskii energy with general non-radial trapping potential, under the unit mass constraint, in the Thomas-Fermi limit where a small parameter tends to 0. This ground state plays an important role in the mathematical treatment of recent experiments on the phenomenon of Bose-Einstein condensation, and in the study of various types of solutions of nonhomogeneous defocusing nonlinear Schrödinger equations. Many of these applications require delicate estimates for the behavior of the ground state near the boundary of the condensate, as , in the vicinity of which the ground state has irregular behavior in the form of a steep corner layer. In particular, the role of this layer is important in order to detect the presence of vortices in the small density region of the condensate, to understand the superfluid flow around an obstacle, and it also has a leading order contribution in the energy. In contrast to previous approaches, we utilize a perturbation argument to go beyond the classical Thomas-Fermi approximation and accurately approximate the layer by the Hastings-McLeod solution of the Painlevé-II equation. This settles an open problem (cf. Aftalion in Vortices in Bose Einstein Condensates. Birkhäuser Boston, Boston, 2006, pg. 13 or Open Problem 8.1), answered very recently only for the special case of the model harmonic potential (Gallo and Pelinovsky in Asymptot Anal 73:53-96, 2011). In fact, we even improve upon previous results that relied heavily on the radial symmetry of the potential trap. Moreover, we show that the ground state has the maximal regularity available, namely it remains uniformly bounded in the -Hölder norm, which is the exact Hölder regularity of the singular limit profile, as . Our study is highly motivated by an interesting open problem posed recently by A ftalion, Jerrard, and R oyo-L etelier (J Funct Anal 260:2387-2406 2011), and an open question of G allo and P elinovsky (J Math Anal

  15. Applied Mathematics in EM Studies with Special Emphasis on an Uncertainty Quantification and 3-D Integral Equation Modelling

    NASA Astrophysics Data System (ADS)

    Pankratov, Oleg; Kuvshinov, Alexey

    2016-01-01

    Despite impressive progress in the development and application of electromagnetic (EM) deterministic inverse schemes to map the 3-D distribution of electrical conductivity within the Earth, there is one question which remains poorly addressed—uncertainty quantification of the recovered conductivity models. Apparently, only an inversion based on a statistical approach provides a systematic framework to quantify such uncertainties. The Metropolis-Hastings (M-H) algorithm is the most popular technique for sampling the posterior probability distribution that describes the solution of the statistical inverse problem. However, all statistical inverse schemes require an enormous amount of forward simulations and thus appear to be extremely demanding computationally, if not prohibitive, if a 3-D set up is invoked. This urges development of fast and scalable 3-D modelling codes which can run large-scale 3-D models of practical interest for fractions of a second on high-performance multi-core platforms. But, even with these codes, the challenge for M-H methods is to construct proposal functions that simultaneously provide a good approximation of the target density function while being inexpensive to be sampled. In this paper we address both of these issues. First we introduce a variant of the M-H method which uses information about the local gradient and Hessian of the penalty function. This, in particular, allows us to exploit adjoint-based machinery that has been instrumental for the fast solution of deterministic inverse problems. We explain why this modification of M-H significantly accelerates sampling of the posterior probability distribution. In addition we show how Hessian handling (inverse, square root) can be made practicable by a low-rank approximation using the Lanczos algorithm. Ultimately we discuss uncertainty analysis based on stochastic inversion results. In addition, we demonstrate how this analysis can be performed within a deterministic approach. In the

  16. Using eddy covariance of CO2, 13CO2 and CH4, continuous soil respiration measurements, and PhenoCams to constrain a process-based biogeochemical model for carbon market-funded wetland restoration

    NASA Astrophysics Data System (ADS)

    Oikawa, P. Y.; Baldocchi, D. D.; Knox, S. H.; Sturtevant, C. S.; Verfaillie, J. G.; Dronova, I.; Jenerette, D.; Poindexter, C.; Huang, Y. W.

    2015-12-01

    We use multiple data streams in a model-data fusion approach to reduce uncertainty in predicting CO2 and CH4 exchange in drained and flooded peatlands. Drained peatlands in the Sacramento-San Joaquin River Delta, California are a strong source of CO2 to the atmosphere and flooded peatlands or wetlands are a strong CO2 sink. However, wetlands are also large sources of CH4 that can offset the greenhouse gas mitigation potential of wetland restoration. Reducing uncertainty in model predictions of annual CO2 and CH4 budgets is critical for including wetland restoration in Cap-and-Trade programs. We have developed and parameterized the Peatland Ecosystem Photosynthesis, Respiration, and Methane Transport model (PEPRMT) in a drained agricultural peatland and a restored wetland. Both ecosystem respiration (Reco) and CH4 production are a function of 2 soil carbon (C) pools (i.e. recently-fixed C and soil organic C), temperature, and water table height. Photosynthesis is predicted using a light use efficiency model. To estimate parameters we use a Markov Chain Monte Carlo approach with an adaptive Metropolis-Hastings algorithm. Multiple data streams are used to constrain model parameters including eddy covariance of CO2, 13CO2 and CH4, continuous soil respiration measurements and digital photography. Digital photography is used to estimate leaf area index, an important input variable for the photosynthesis model. Soil respiration and 13CO2 fluxes allow partitioning of eddy covariance data between Reco and photosynthesis. Partitioned fluxes of CO2 with associated uncertainty are used to parametrize the Reco and photosynthesis models within PEPRMT. Overall, PEPRMT model performance is high. For example, we observe high data-model agreement between modeled and observed partitioned Reco (r2 = 0.68; slope = 1; RMSE = 0.59 g C-CO2 m-2 d-1). Model validation demonstrated the model's ability to accurately predict annual budgets of CO2 and CH4 in a wetland system (within 14% and 1

  17. Imaging the concealed section of the Whakatane fault below Whakatane city, New Zealand, with a shear wave land streamer system

    NASA Astrophysics Data System (ADS)

    Polom, Ulrich; Mueller, Christof; Krawczyk, CharLotte M.

    2016-04-01

    The Mw 7.1 Darfield Earthquake in September 2010 ruptured the surface along the Greendale Fault that was not known prior to the earthquake. The subsequent Mw 6.3 Christchurch earthquake in February 2011 demonstrated that concealed active faults have a significant risk potential for urban infrastructure and human life in New Zealand if they are located beneath or close to such areas. Mapping exposures and analysis of active faults incorporated into the National Seismic Hazard Model (NSHM) suggests that several thousands of these active structures are yet to be identified and have the potential to generate moderate to large magnitude earthquakes (i.e. magnitudes >5). Geological mapping suggests that active faults pass beneath, or within many urban areas in New Zealand, including Auckland, Blenheim, Christchurch, Hastings/Napier, Nelson, Rotorua, Taupo, Wellington, and Whakatane. Since no established methodology for routinely locating and assessing the earthquake hazard posed by concealed active faults is available, the principal objective of the presented study was to evaluate the usefulness of high-resolution shear wave seismic reflection profiling using a land streamer to locate buried faults in urban areas of New Zealand. During the survey carried out in the city of Whakatane in February 2015, the method was first tested over a well known surface outcrop of the Edgecumbe Fault 30 km south-west of Whakatane city. This allowed further to investigate the principle shear wave propagation characteristics in the unknown sediments, consisting mainly of effusive rock material of the Taupo volcanic zone mixed with marine transgression units. Subsequently the survey was continued within Whakatane city using night operation time slots to reduce the urban noise. In total, 11 profiles of 5.7 km length in high data quality were acquired, which clearly show concealed rupture structures of obviously different age in the shallow sediments down to 100 m depth. Subject to depth

  18. Model parameter estimations from residual gravity anomalies due to simple-shaped sources using Differential Evolution Algorithm

    NASA Astrophysics Data System (ADS)

    Ekinci, Yunus Levent; Balkaya, Çağlayan; Göktürkler, Gökhan; Turan, Seçil

    2016-06-01

    An efficient approach to estimate model parameters from residual gravity data based on differential evolution (DE), a stochastic vector-based metaheuristic algorithm, has been presented. We have showed the applicability and effectiveness of this algorithm on both synthetic and field anomalies. According to our knowledge, this is a first attempt of applying DE for the parameter estimations of residual gravity anomalies due to isolated causative sources embedded in the subsurface. The model parameters dealt with here are the amplitude coefficient (A), the depth and exact origin of causative source (zo and xo, respectively) and the shape factors (q and ƞ). The error energy maps generated for some parameter pairs have successfully revealed the nature of the parameter estimation problem under consideration. Noise-free and noisy synthetic single gravity anomalies have been evaluated with success via DE/best/1/bin, which is a widely used strategy in DE. Additionally some complicated gravity anomalies caused by multiple source bodies have been considered, and the results obtained have showed the efficiency of the algorithm. Then using the strategy applied in synthetic examples some field anomalies observed for various mineral explorations such as a chromite deposit (Camaguey district, Cuba), a manganese deposit (Nagpur, India) and a base metal sulphide deposit (Quebec, Canada) have been considered to estimate the model parameters of the ore bodies. Applications have exhibited that the obtained results such as the depths and shapes of the ore bodies are quite consistent with those published in the literature. Uncertainty in the solutions obtained from DE algorithm has been also investigated by Metropolis-Hastings (M-H) sampling algorithm based on simulated annealing without cooling schedule. Based on the resulting histogram reconstructions of both synthetic and field data examples the algorithm has provided reliable parameter estimations being within the sampling limits of

  19. A Methodology for Post Operational Clean Out of a Highly Active Facility Including Solids Behaviour - 12386

    SciTech Connect

    Edmondson, Michael J.; Ward, Tracy R.; Maxwell, Lisa J.

    2012-07-01

    The Highly Active Liquor Evaporation and Storage (HALES) plant at Sellafield handles acidic fission product containing liquor with typical activities of the order of 18x10{sup 9} Bq/ml. A strategy experimental feedback approach has been used to establish a wash regime for the Post Operational Clean Out (POCO) of the oldest storage tanks for this liquor. Two different wash reagents have been identified as being potentially suitable for removal of acid insoluble fission product precipitates. Ammonium carbamate and sodium carbonate yield similar products during the proposed wash cycle. The proposed wash reagents provide dissolution of caesium phosphomolybdate (CPM) and zirconium molybdate (ZM) solid phases but yields a fine, mobile precipitate of metal carbonates from the Highly Active Liquor (HAL) supernate. Addition of nitric acid to the wash effluent can cause CPM to precipitate where there is sufficient caesium and phosphorous available. Where they are not present (from ZM dissolution) the nitric acid addition initially produces a nitrate precipitate which then re-dissolves, along with the metal carbonates, to give a solid-free solution. The different behaviour of the two solids during the wash cycle has led to the proposal for an amended flowsheet. Additional studies on the potential to change the morphology of crystallising ZM have presented opportunities for changing the rheology of ZM sediments through doping with tellurium or particular organic acids. Two different wash reagents have been identified as being potentially suitable for the POCO of HALES Oldside HASTs. AC and SC both yield similar products during the proposed wash cycle. However, the different behaviour of the two principle HAL solids, CPM and ZM, during the wash cycle has led to the proposal for an amended flowsheet. Additional studies on the potential to change the morphology of crystallising ZM have presented opportunities for changing its rheology through doping with tellurium or certain

  20. CMA Announces the 1996 Responsible Care Catalyst Awards Winners

    NASA Astrophysics Data System (ADS)

    1996-06-01

    Eighteen exceptional teachers of science, chemical technology, chemistry, and chemical engineering have been selected to receive a Responsible Care Chemical Manufacturers Association's 1996 Catalyst Award. The Responsible Care Catalyst Awards Program honors individuals who have the ability to inspire students toward careers in chemistry and science-related fields through their excellent teaching ability in and out of the classroom. The program also seeks to draw public attention to the importance of quality chemistry and science teaching at the undergraduate level. Since the award was established in 1957, 502 teachers of science, chemistry, and chemical engineering have been honored. Winners are selected from a wide range of nominations submitted by colleagues, friends, and administrators. All pre-high school, high school, two and four-year college, or university teachers in the United States and Canada are eligible. Each award winner will be presented with a medal and citation. National award winners receive 5,000; regional award winners receive 2,500. National Winners. Martin N. Ackermann, Oberlin College, Oberlin, OH Kenneth R. Jolls, Iowa State University, Ames, IA Suzanne Zobrist Kelly, Warren H. Meeker Elementary School, Ames, IA John V. Kenkel, Southeast Community College, Lincoln, NE George C. Lisensky, Beloit College, Beloit, WI James M. McBride, Yale University, New Haven, CT Marie C. Sherman, Ursuline Academy, St. Louis, MO Dwight D. Sieggreen, Cooke Middle School, Northville, MI Regional Winners Two-Year College. East-Georgianna Whipple-VanPatter, Central Community College, Hastings, NE West-David N. Barkan, Northwest College, Powell, WY High School. East-John Hnatow, Jr., Emmaus High School, Northampton, PA South-Carole Bennett, Gaither High School, Tampa, FL Midwest-Kenneth J. Spengler, Palatine High School, Palatine, IL West-Ruth Rand, Albuquerque, Albuquerque, NM Middle School. East-Thomas P. Kelly, Grandville Public Schools, Grandville, NH

  1. [A clinical study of generalized amnesia].

    PubMed

    Takahashi, Y

    1989-01-01

    Six cases of generalized amnesia were reported. Generalized amnesia caused by phenomena of genuinely psychogenic origin is a rare psychological disorder and spontaneous recovery from amnesia in a comparatively short period of time is one of the characteristics of this disorder. Three of the cases in this report developed amnesia which was prolonged in comparison with previously reported cases. A comparison between these six cases and previously reported cases of amnesia elucidated the general characteristics of this disorder, differential diagnosis from other disorders, the development of a new identity during the amnestic period, amnesia as an alternative to suicide, factors related to prolonged amnesia, and its treatment. Although differential diagnosis from other disorders, especially from malingering, is sometimes difficult, the patient's attitude toward amnesia, the development of the clinical course of amnesia, the premorbid personal history, and interpersonal relationships should be carefully observed and evaluated in order to differentiate generalized amnesia from malingering. During the amnestic period it was observed that three of the cases believed that they had names of other persons, and two of them recalled personal histories completely different from their own. Previously, such phenomena have been mainly discussed from the view-point of pseudologia fantastica or malingering in Japan. The author discusses how a new identity could be developed in cases of generalized amnesia. According to Abeles, et al., generalized amnesia can sometimes serve as psychological suicide. The author emphasizes that the patient's suicidal risk should be evaluated carefully, even if he or she does not seem highly suicidal superficially. Excessive haste to recover from amnesia may heighten the suicidal risk or help develop a distorted personal identity. The principle for the treatment is to exclude an unnecessary therapeutic manipulation and maintain a consistent and

  2. Chemical composition of Texas surface waters, 1949

    USGS Publications Warehouse

    Irelan, Burdge

    1950-01-01

    This report is the fifth the a series of publications by the Texas Board of Water Engineers giving chemical analyses of the surface waters in the State of Texas. The samples for which data are given were collected between October 1, 1948 and September 30, 1949. During the water year 25 daily sampling stations were maintained by the Geological Survey. Sampled were collected less frequently during the year at many other points. Quality of water records for previous years can be found in the following reports: "Chemical Composition of Texas Surface Waters, 1938-1945," by W. W. Hastings, and J. H. Rowley; "Chemical Composition of Texas Surface Waters, 1946," by W. W. Hastings and B. Irelan; "Chemical Composition of Texas Surface Waters, 1947," by B. Irelan and J. R. Avrett; "Chemical Composition of Texas Surface Waters, 1948," by B. Irelan, D. E. Weaver, and J. R. Avrett. These reports may be obtained from the Texas Board of Water Engineers and Geological Survey at Austin, Texas. Samples for chemical analysis were collected daily at or near points on streams where gaging stations are maintained for measurement of discharge. Most of the analyses were made of 10-day composites of daily samples collected for a year at each sampling point. Three composite samples were usually prepared each month by mixing together equal quantities of daily samples collected for the 1st to the 10th, from the 11th to the 20th, and during the remainder of the month. Monthly composites were made at a few stations where variation in daily conductance was small. For some streams that are subject to sudden large changes in chemical composition, composite samples were made for shorter periods on the basis of the concentration of dissolved solids as indicated by measurement of specific conductance of the daily samples. The mean discharge for the composite period is reported in second-feet. Specific conductance values are expressed as "micromhos, K x 10 at 25° C." Silica, calcium, magnesium, sodium

  3. MAGNOX:BUTEX URANIUM BEARING GLASSES PHYSICAL AND CHEMICAL ANALYSIS DATA PACKAGE

    SciTech Connect

    Peeler, D.; Imrich, K.; Click, D.

    2011-03-08

    Sellafield Ltd (United Kingdom) has requested technical support from the Savannah River National Laboratory (SRNL) to characterize a series of uranium-bearing, mixed alkali borosilicate glasses [WFO (2010)]. The specific glasses to be characterized are based on different blends of Magnox (WRW17 simulant) and Butex (or HASTs 1 and 2) waste types as well as different incorporation rates (or waste loadings) of each blend. Specific Magnox:Butex blend ratios of interest include: 75:25, 60:40, and 50:50. Each of these waste blend ratios will be mixed with a base glass additive composition targeting waste loadings (WLs) of 25, 28, and 32% which will result in nine different glasses. The nine glasses are to be fabricated and physically characterized to provide Sellafield Ltd with the technical data to evaluate the impacts of various Magnox:Butex blend ratios and WLs on key glass properties of interest. It should be noted that the use of 'acceptable' in the Work for Other (WFO) was linked to the results of a durability test (more specifically the Soxhlet leach test). Other processing (e.g., viscosity ({eta}), liquidus temperature (T{sub L})) or product performance (e.g., Product Consistency Test (PCT) results - in addition to the Soxhlet leach test) property constraints were not identified. For example, a critical hold point in the classification of an 'acceptable glass' prior to processing high-level waste (HLW) through the Defense Waste Processing Facility (DWPF) is an evaluation of specific processing and product performance properties against pre-defined constraints. This process is referred to as Slurry Mix Evaporator (SME) acceptability in which predicted glass properties (based on compositional measurements) are compared to predefined constraints to determine whether the glass is acceptable [Brown and Postles (1995)]. As an example, although the nominal melter temperature at DWPF is 1150 C, there is a T{sub L} constraint (without uncertainties applied) of 1050 C. Any

  4. Stimulation of Mojave Desert net ecosystem CO2 uptake after winter precipitation with the opposite effect after summer rains based on 7 years of flux data

    NASA Astrophysics Data System (ADS)

    Jasoni, Richard; Arnone, John; Fenstermaker, Lynn; Wohlfahrt, Georg

    2014-05-01

    Eddy covariance measurements of net ecosystem CO2 exchange (NEE) in the Mojave Desert (Jasoni et al. 2005-Global Change Biology 11:749-756; Wohlfahrt et al. 2008-Global Change Biology 14:1475-1487), and in other deserts of the world (e.g., Hastings et al. 2005- Global Change Biology 14:927-939, indicate greater rates of net CO2 uptake (more negative NEE values) and net ecosystem productivity (NEP) than would have been expected for deserts (as high as -120 g C m-2 year-1). We continue to observe high rates of NEE and NEP and seek explanations for these findings at interannual, seasonal, and sub-seasonal time scales. Because moisture availability most strongly constrains biological activity in deserts, responses to rains probably play a significant role in defining components of NEE-namely net primary productivity (NPP, or roughly net photosynthesis by vascular and non-vascular plants) and heterotrophic respiration (Rh, mainly by soil microorganisms). Most precipitation in the Mojave Desert falls from October through April and periodically in the summer as convective storms. The main objective of this study was to quantify the extent to which NEE and the net flux of CO2 from/to biological soil crust (BSC) covered soil surfaces respond to rain pulses occurring during cool/cold and warm/hot times of the year. Flux data from 7 years (2005-2011) of measurements at our shub land desert site (average 150 mm rain per year) located 120 km northwest of Las Vegas showed a range in NEP from -111±34 to -47±28 g C m-2 year-1. Cool season rains usually stimulated NEE (more negative NEE values or net CO2 uptake) while warm season rains reversed this effect and led to positive NEE values (net ecosystem CO2 efflux. Cool season stimulation of NEE often occurred in the absence of green leaves on vascular plants, suggesting that photosynthesis of BSCs (up to 70% of soil surface covered by cyanobacteria, mosses, and lichens) were responsible for this net uptake. At other times during

  5. Long-term tillage and crop rotation effects on residual nitrate in the crop root zone and nitrate accumulation in the intermediate vadose zone

    USGS Publications Warehouse

    Katupitiya, A.; Eisenhauer, D.E.; Ferguson, R.B.; Spalding, R.F.; Roeth, F.W.; Bobier, M.W.

    1997-01-01

    Tillage influences the physical and biological environment of soil. Rotation of crops with a legume affects the soil N status. A furrow irrigated site was investigated for long-term tillage and crop rotation effects on leaching of nitrate from the root zone and accumulation in the intermediate vadose zone (IVZ). The investigated tillage systems were disk-plant (DP), ridge-till (RT) and slot-plant (SP). These tillage treatments have been maintained on the Hastings silt loam (Udic Argiustoll) and Crete silt loam (Pachic Argiustoll) soils since 1976. Continuous corn (CC) and corn soybean (CS) rotations were the subtreatments. Since 1984, soybeans have been grown in CS plots in even calendar years. All tillage treatments received the same N rate. The N rate varied annually depending on the root zone residual N. Soybeans were not fertilized with N-fertilizer. Samples for residual nitrate in the root zone were taken in 8 of the 15 year study while the IVZ was only sampled at the end of the study. In seven of eight years, root zone residual soil nitrate-N levels were greater with DP than RT and SP. Residual nitrate-N amounts were similar in RT and SP in all years. Despite high residual nitrate-N with DP and the same N application rate, crop yields were higher in RT and SP except when DP had an extremely high root zone nitrate level. By applying the same N rates on all tillage treatments, DP may have been fertilized in excess of crop need. Higher residual nitrate-N in DP was most likely due to a combination of increased mineralization with tillage and lower yield compared to RT and SP. Because of higher nitrate availability with DP, the potential for nitrate leaching from the root zone was greater with DP as compared to the RT and SP tillage systems. Spring residual nitrate-N contents of DP were larger than RT and SP in both crop rotations. Ridge till and SP systems had greater nitrate-N with CS than CC rotations. Nitrate accumulation in IVZ at the upstream end of the

  6. Stratigraphy and structural development of the southwest Isla Tiburón marine basin: Implications for latest Miocene tectonic opening and flooding of the northern Gulf of California

    USGS Publications Warehouse

    Bennett, Scott E K.; Oskin, Michael; Dorsey, Rebecca; Iriondo, Alexander; Kunk, Michael J.

    2015-01-01

    Accurate information on the timing of earliest marine incursion into the Gulf of California (northwestern México) is critical for paleogeographic models and for understanding the spatial and temporal evolution of strain accommodation across the obliquely divergent Pacific-North America plate boundary. Marine strata exposed on southwest Isla Tiburón (SWIT) have been cited as evidence for a middle Miocene marine incursion into the Gulf of California at least 7 m.y. prior to plate boundary localization ca. 6 Ma. A middle Miocene interpretation for SWIT marine deposits has played a large role in subsequent interpretations of regional tectonics and rift evolution, the ages of marine basins containing similar fossil assemblages along ~1300 km of the plate boundary, and the timing of marine incursion into the Gulf of California. We report new detailed geologic mapping and geochronologic data from the SWIT basin, an elongate sedimentary basin associated with deformation along the dextral-oblique La Cruz fault. We integrate these results with previously published biostratigraphic and geochronologic data to bracket the age of marine deposits in the SWIT basin and show that they have a total maximum thickness of ~300 m. The 6.44 ± 0.05 Ma (Ar/Ar) tuff of Hast Pitzcal is an ash-flow tuff stratigraphically below the oldest marine strata, and the 6.01 ± 0.20 Ma (U/Pb) tuff of Oyster Amphitheater, also an ash-flow tuff, is interbedded with marine conglomerate near the base of the marine section. A dike-fed rhyodacite lava flow that caps all marine strata yields ages of 3.51 ± 0.05 Ma (Ar/Ar) and 4.13 ± 0.09 Ma (U/Pb) from the base of the flow, consistent with previously reported ages of 4.16 ± 1.81 Ma (K-Ar) from the flow top and (K-Ar) 3.7 ± 0.9 Ma from the feeder dike. Our new results confirm a latest Miocene to early Pliocene age for the SWIT marine basin, consistent with previously documented latest Miocene to early Pliocene (ca. 6.2-4.3 Ma) planktonic and benthic

  7. Estimating national forest carbon stocks and dynamics: combining models and remotely sensed information

    NASA Astrophysics Data System (ADS)

    Smallman, Luke; Williams, Mathew

    2016-04-01

    Forests are a critical component of the global carbon cycle, storing significant amounts of carbon, split between living biomass and dead organic matter. The carbon budget of forests is the most uncertain component of the global carbon cycle - it is currently impossible to quantify accurately the carbon source/sink strength of forest biomes due to their heterogeneity and complex dynamics. It has been a major challenge to generate robust carbon budgets across landscapes due to data scarcity. Models have been used but outputs have lacked an assessment of uncertainty, making a robust assessment of their reliability and accuracy challenging. Here a Metropolis Hastings - Markov Chain Monte Carlo (MH-MCMC) data assimilation framework has been used to combine remotely sensed leaf area index (MODIS), biomass (where available) and deforestation estimates, in addition to forest planting and clear-felling information from the UK's national forest inventory, an estimate of soil carbon from the Harmonized World Database (HWSD) and plant trait information with a process model (DALEC) to produce a constrained analysis with a robust estimate of uncertainty of the UK forestry carbon budget between 2000 and 2010. Our analysis estimates the mean annual UK forest carbon sink at -3.9 MgC ha-1yr-1 with a 95 % confidence interval between -4.0 and -3.1 MgC ha-1 yr-1. The UK national forest inventory (NFI) estimates the mean UK forest carbon sink to be between -1.4 and -5.5 MgC ha-1 yr-1. The analysis estimate for total forest biomass stock in 2010 is estimated at 229 (177/232) TgC, while the NFI an estimated total forest biomass carbon stock of 216 TgC. Leaf carbon area (LCA) is a key plant trait which we are able to estimate using our analysis. Comparison of median estimates for LCA retrieved from the analysis and a UK land cover map show higher and lower values for LCA are estimated areas dominated by needle leaf and broad leaf forests forest respectively, consistent with ecological

  8. Bacteriocins: modes of action and potentials in food preservation and control of food poisoning.

    PubMed

    Abee, T; Krockel, L; Hill, C

    1995-12-01

    -negative bacteria possess an additional layer, the so-called outer membrane which is composed of phospholipids, proteins and lipopolysaccharides (LPS), and this membrane is impermeable to most molecules. Nevertheless, the presence of porins in this layer will allow the free diffusion of molecules with a molecular mass below 600 Da. The smallest bacteriocins produced by lactic acid bacteria are approximately 3 kDa and are thus too large to reach their target, the cytoplasmic membrane (Klaenhammer, 1993; Stiles and Hastings, 1991). However, Stevens et al. (1991) and Ray (1993) have demonstrated that Salmonella species and other Gram-negative bacteria become sensitive to nisin after exposure to treatments that change the permeability barrier properties of the outer membrane (see below). This review will focus on the mode of action of lantibiotics (class I) and class II LAB bacteriocins and their potentials in food preservation and control of food poisoning. PMID:8750665

  9. Spatial Intensity Duration Frequency Relationships Using Hierarchical Bayesian Analysis for Urban Areas

    NASA Astrophysics Data System (ADS)

    Rupa, Chandra; Mujumdar, Pradeep

    2016-04-01

    In urban areas, quantification of extreme precipitation is important in the design of storm water drains and other infrastructure. Intensity Duration Frequency (IDF) relationships are generally used to obtain design return level for a given duration and return period. Due to lack of availability of extreme precipitation data for sufficiently large number of years, estimating the probability of extreme events is difficult. Typically, a single station data is used to obtain the design return levels for various durations and return periods, which are used in the design of urban infrastructure for the entire city. In an urban setting, the spatial variation of precipitation can be high; the precipitation amounts and patterns often vary within short distances of less than 5 km. Therefore it is crucial to study the uncertainties in the spatial variation of return levels for various durations. In this work, the extreme precipitation is modeled spatially using the Bayesian hierarchical analysis and the spatial variation of return levels is studied. The analysis is carried out with Block Maxima approach for defining the extreme precipitation, using Generalized Extreme Value (GEV) distribution for Bangalore city, Karnataka state, India. Daily data for nineteen stations in and around Bangalore city is considered in the study. The analysis is carried out for summer maxima (March - May), monsoon maxima (June - September) and the annual maxima rainfall. In the hierarchical analysis, the statistical model is specified in three layers. The data layer models the block maxima, pooling the extreme precipitation from all the stations. In the process layer, the latent spatial process characterized by geographical and climatological covariates (lat-lon, elevation, mean temperature etc.) which drives the extreme precipitation is modeled and in the prior level, the prior distributions that govern the latent process are modeled. Markov Chain Monte Carlo (MCMC) algorithm (Metropolis Hastings

  10. Discharge estimates on a small braided river based on synthetic SWOT measurements

    NASA Astrophysics Data System (ADS)

    Paiva, R. C.; Durand, M. T.; Schubert, J.; Sanders, B. F.; Andreadis, K.

    2013-12-01

    This research focuses on the feasibility of estimating discharge in a small braided river, the Platte in Nebraska, USA, using synthetic measurements from the upcoming Surface Water and Ocean Topography (SWOT) satellite mission. The SWOT mission is designed to provide observations of surface water elevations (WSE) together with its spatio-temporal derivatives and inundated area. Discharge is subsequently estimated by fitting a 1D diffusive wave discharge formula to SWOT-derived river attributes including WSE, river width (W) and slope (S) using the Metropolis-Hastings algorithm, a Monte-Carlo Markov-Chain (MCMC) method. This involves the estimation of two parameters, the river roughness coefficient (η) and low-flow cross-sectional area (A0). A two-dimensional (2D) hydrodynamic model (BreZo) was applied to a 10 km reach of the Platte to produce synthetic SWOT measurements at a river resolution of approximately 3 m and for a period of 48 hours, during which a small flood progressed through the reach. BreZo was parameterized from a 1 m resolution Digital Terrain Model derived from an aerial lidar collected during low flow conditions, thus capturing many small scale morphological features, and was forced by discharge observations at a USGS gauging station located at the upstream boundary of the reach. This approach offers a level of detail in WSE variability that has previously been absent from SWOT discharge estimation studies, including riffle-pool morphological structures, and thus represents a rigorous test of the discharge estimation methodology. To estimate discharge from BreZo output, the Platte was split into 3 km reaches and output was sampled every four hours. WSE and S were averaged for each reach while W was estimated as the ratio between inundated area and reach length. Uncertainty of these variables was assumed as 10 cm, 1 cm/km and 15%, respectively. Generally, estimated η and A0 values were close to the modeled values and discharge estimates agreed

  11. Carbon Capture and Sequestration from a Hydrogen Production Facility in an Oil Refinery

    SciTech Connect

    Engels, Cheryl; Williams, Bryan, Valluri, Kiranmal; Watwe, Ramchandra; Kumar, Ravi; Mehlman, Stewart

    2010-06-21

    The project proposed a commercial demonstration of advanced technologies that would capture and sequester CO2 emissions from an existing hydrogen production facility in an oil refinery into underground formations in combination with Enhanced Oil Recovery (EOR). The project is led by Praxair, Inc., with other project participants: BP Products North America Inc., Denbury Onshore, LLC (Denbury), and Gulf Coast Carbon Center (GCCC) at the Bureau of Economic Geology of The University of Texas at Austin. The project is located at the BP Refinery at Texas City, Texas. Praxair owns and operates a large hydrogen production facility within the refinery. As part of the project, Praxair would construct a CO2 capture and compression facility. The project aimed at demonstrating a novel vacuum pressure swing adsorption (VPSA) based technology to remove CO2 from the Steam Methane Reformers (SMR) process gas. The captured CO2 would be purified using refrigerated partial condensation separation (i.e., cold box). Denbury would purchase the CO2 from the project and inject the CO2 as part of its independent commercial EOR projects. The Gulf Coast Carbon Center at the Bureau of Economic Geology, a unit of University of Texas at Austin, would manage the research monitoring, verification and accounting (MVA) project for the sequestered CO2, in conjunction with Denbury. The sequestration and associated MVA activities would be carried out in the Hastings field at Brazoria County, TX. The project would exceed DOE?s target of capturing one million tons of CO2 per year (MTPY) by 2015. Phase 1 of the project (Project Definition) is being completed. The key objective of Phase 1 is to define the project in sufficient detail to enable an economic decision with regard to proceeding with Phase 2. This topical report summarizes the administrative, programmatic and technical accomplishments completed in Phase 1 of the project. It describes the work relative to project technical and design activities

  12. Carbon Capture and Sequestration (via Enhanced Oil Recovery) from a Hydrogen Production Facility in an Oil Refinery

    SciTech Connect

    Stewart Mehlman

    2010-06-16

    The project proposed a commercial demonstration of advanced technologies that would capture and sequester CO2 emissions from an existing hydrogen production facility in an oil refinery into underground formations in combination with Enhanced Oil Recovery (EOR). The project is led by Praxair, Inc., with other project participants: BP Products North America Inc., Denbury Onshore, LLC (Denbury), and Gulf Coast Carbon Center (GCCC) at the Bureau of Economic Geology of The University of Texas at Austin. The project is located at the BP Refinery at Texas City, Texas. Praxair owns and operates a large hydrogen production facility within the refinery. As part of the project, Praxair would construct a CO2 capture and compression facility. The project aimed at demonstrating a novel vacuum pressure swing adsorption (VPSA) based technology to remove CO2 from the Steam Methane Reformers (SMR) process gas. The captured CO2 would be purified using refrigerated partial condensation separation (i.e., cold box). Denbury would purchase the CO2 from the project and inject the CO2 as part of its independent commercial EOR projects. The Gulf Coast Carbon Center at the Bureau of Economic Geology, a unit of University of Texas at Austin, would manage the research monitoring, verification and accounting (MVA) project for the sequestered CO2, in conjunction with Denbury. The sequestration and associated MVA activities would be carried out in the Hastings field at Brazoria County, TX. The project would exceed DOE’s target of capturing one million tons of CO2 per year (MTPY) by 2015. Phase 1 of the project (Project Definition) is being completed. The key objective of Phase 1 is to define the project in sufficient detail to enable an economic decision with regard to proceeding with Phase 2. This topical report summarizes the administrative, programmatic and technical accomplishments completed in Phase 1 of the project. It describes the work relative to project technical and design activities

  13. Genetics, amniocentesis, and abortion.

    PubMed

    Hirschhorn, K

    1984-01-01

    At this time a rather large number of congenital abnormalities still occur. About 2-3% of pregnancies will result in children with major congenital abnormalities that cannot be detected prenatally. Yet, with the availability of prenatal diagnosis for an ever increasing number of genetic problems and, more recently, for developmental problems as well, a new option was offered to couples at risk when they took the risk of pregnancy: finding out whether the fetus was abnormal. An early argument regarding the ethics of this option was formulated by Dan Callahan, director of the Hastings Institute for Ethics, Society and the Life Sciences, when he indicated the need to be careful about the term "option." A need exists to be careful about societal pressures in favor of the new medical options--on, for example, a pregnant woman who is over 35 and does not get a prenatal diagnosis; or on a woman carrying a Down's syndrome child identified by prenatal diagnosis not to have an abortion. This was the 1st specter raised when prenatal diagnosis was introduced. The most common indication for amniocentesis is the risk of chromosomal abnormalities. The risk of discovering a chromosomal abnormality by amniocentesis is about double the risk at birth because a number of chromosomally abnormal fetuses are lost late in the 2nd trimester by spontaneous abortion. The age cutoff at 35 raises an immediate ethical question: since the total number of births to women over age 35 seems to be increasing, and at the same time a greater and greater percentage of children with Down's syndrome are born to women under age 35, the question arises as to whether amniocentesis should be done on all pregnancies, and whether all births with Down's syndrome should be selectively aborted or avoided. Amniocentesis in all pregnancies is impractical at this time from the technological and the cost perspective, but the ethical question should be raised. Among the X-linked disorders, 1 group cannot be

  14. Refining calibration and predictions of a Bayesian statistical-dynamical model for long term avalanche forecasting using dendrochronological reconstructions

    NASA Astrophysics Data System (ADS)

    Eckert, Nicolas; Schläppy, Romain; Jomelli, Vincent; Naaim, Mohamed

    2013-04-01

    chronicle is performed with various prior distributions resulting from expert knowledge and/or other paths. For all calibrations, a very successful convergence is obtained, which confirms the robustness of the used Metropolis-Hastings estimation algorithm. This also demonstrates the interest of the Bayesian framework for aggregating information by sequential assimilation in the frequently encountered case of limited data quantity. Confrontation with the dendrological sample stresses the predominant role of the Coulombian friction coefficient distribution's variance on predicted high magnitude runouts. The optimal fit is obtained for a strong prior reflecting the local bounded behavior, and results in a 10-40 m difference for return periods ranging between 10 and 300 years. Implementing predictive simulations shows that this is largely within the range of magnitude of uncertainties to be taken into account. On the other hand, the different priors tested for the turbulent friction coefficient influence predictive performances only slightly, but have a large influence on predicted velocity and flow depth distributions. This all may be of high interest to refine calibration and predictive use of the statistical-dynamical model for any engineering application.

  15. Correlation between the Palaeozoic structures from West Iberian and Grand Banks margins using inversion of magnetic anomalies

    NASA Astrophysics Data System (ADS)

    Silva, Elsa A.; Miranda, J. M.; Luis, J. F.; Galdeano, A.

    2000-05-01

    The Ibero-Armorican Arc (IAA) is a huge geological structure of Pre-Cambrian origin, tightened during hercynian times and deeply affected by the opening of the Atlantic Ocean and the Bay of Biscay. Its remnants now lie in Iberia, north-western France and the Canadian Grand Banks margins. The qualitative correlation between these three blocks has been attempted by several authors (e.g. Lefort, J.P., 1980. Un 'Fit' structural de l'Atlantique Nord: arguments geologiques pour correler les marqueurs geophysiques reconnus sur les deux marges. Mar. Geol. 37, 355-369; Lefort, J.P., 1983. A new geophysical criterion to correlate the Acadian and Hercynian orogenies of Western Europe and Eastern America. Mem. Geol. Soc. Am. 158, 3-18; Galdeano, A., Miranda, J.M., Matte, P., Mouge, P., Rossignol, C., 1990. Aeromagnetic data: A tool for studying the Variscan arc of Western Europe and its correlation with transatlantic structures. Tectonophysics 177, 293-305) using magnetic anomalies, mainly because they seem to preserve the hercynian zonation, in spite of the strong thermal and mechanical processes that took place during rifting and ocean spreading. In this paper, we present a new contribution to the study of the IAA structure based on the processing of a compilation of magnetic data from Iberia and Grand Banks margins. To interpret the magnetic signature, a Fourier-domain-based inversion technique was applied, considering a layer with a constant thickness of 10 km, and taking into account only the induced field. The digital terrain model was derived from ETOPO5 (ETOPO5, 1986. Relief map of the earth's surface. EOS 67, 121) and TerrainBase (TerrainBase, 1995. In: Row III, L.W., Hastings, D.A., Dunbar, P.K. (Eds.), Worldwide Digital Terrain Data, Documentation Manual, CD-ROM Release 1.0. GEODAS-NGDC Key to Geophysical Records. Documentation N. 30, April) databases. The pseudo-susceptibility distribution obtained was repositioned for the 156.5 Ma epoch, using the Srivastava and

  16. Analysis of the Thermo-Elastic Response of Space Reflectors to Simulated Space Environment

    NASA Astrophysics Data System (ADS)

    Allegri, G.; Ivagnes, M. M.; Marchetti, M.; Poscente, F.

    2002-01-01

    high pressure Xenon lamps to simulate the direct solar irradiation and a cryogenic heat exchanger to reproduce the earth shadowing of sunlight. The temperature of the thermal cycles ranges from -80°C up to 100°C: the thermo-elastic response of the antenna has been surveyed by employing strain gauges place on the structures at several different locations. The structure has been subjected to 100 thermal cycles, each of which lasting two hours: the total duration of the exposition to the vacuum environment has been equal to 300 hours. Finally the antenna has been disassembled and its elements have been examined to evaluate the effects of the simulated exposition on each of them: the total mass loss and the final thermo-mechanical properties of the polymeric based materials which constitute the structural core of the antenna have been surveyed. The experimental results have been compared to numerical simulation performed by the NASTRAN code: the basic FEM model, developed for the unexposed antenna, has been updated to take into account the thermo-mechanical degradation of the structural elements and materials. This has allowed to obtain, by extrapolation, a FEM based prevision of the antenna thermo-elastic response for long-term operative conditions. References. [1] D. Hastings, H. Garret "Spacecraft environment interactions", Cambridge University Press, Atmospheric Series, Cambridge, 1996. [2] IAF-01-I.6.05 "On the Reliability of Honeycomb Core Bonding Joint in Sandwich Composite Materials for Space Applications" G. Allegri, U. Lecci, M. Marchetti, F. Poscente, 52° IAF Congress, 2001. [3] Meguro A. and alii, "Technology status of the 13 m aperture deployment antenna reflectors for Engineering Test Satellite VIII", Acta Astronautica, Volume: 47, Issue: 2-9, July - November, 2000, pp. 147-152. [4] Novikov L. S. "Contemporary state of spacecraft/environment interaction research" Radiation Measurements, Volume: 30, Issue: 5, October, 1999, pp. 661-667. [5] IAF-01-I.1

  17. Lake Charles CCS Project

    SciTech Connect

    Leib, Thomas; Cole, Dan

    2015-06-30

    , construction labor, engineering, and other costs. The CCS Project Final Technical Report is based on a Front End Engineering and Design (FEED) study prepared by SK E&C, completed in [June] 2014. Subsequently, Fluor Enterprises completed a FEED validation study in mid-September 2014. The design analyses indicated that the FEED package was sufficient and as expected. However, Fluor considered the construction risk based on a stick-build approach to be unacceptable, but construction risk would be substantially mitigated through utilization of modular construction where site labor and schedule uncertainty is minimized. Fluor’s estimate of the overall EPC project cost utilizing the revised construction plan was comparable to SKE&C’s value after reflecting Fluor’s assessment of project scope and risk characteristic. Development was halted upon conclusion of Phase 2A FEED and the project was not constructed.Transport and Sequestration – The overall objective of the pipeline project was to construct a pipeline to transport captured CO2 from the Lake Charles Clean Energy project to the existing Denbury Green Line and then to the Hastings Field in Southeast Texas to demonstrate effective geologic sequestration of captured CO2 through commercial EOR operations. The overall objective of the MVA portion of the project was to demonstrate effective geologic sequestration of captured CO2 through commercial Enhanced Oil Recovery (EOR) operations in order to evaluate costs, operational processes and technical performance. The DOE target for the project was to capture and implement a research MVA program to demonstrate the sequestration through EOR of approximately one million tons of CO2 per year as an integral component of commercial operations.

  18. Vertically Integrated Seismological Analysis II : Inference

    NASA Astrophysics Data System (ADS)

    Arora, N. S.; Russell, S.; Sudderth, E.

    2009-12-01

    Methods for automatically associating detected waveform features with hypothesized seismic events, and localizing those events, are a critical component of efforts to verify the Comprehensive Test Ban Treaty (CTBT). As outlined in our companion abstract, we have developed a hierarchical model which views detection, association, and localization as an integrated probabilistic inference problem. In this abstract, we provide more details on the Markov chain Monte Carlo (MCMC) methods used to solve this inference task. MCMC generates samples from a posterior distribution π(x) over possible worlds x by defining a Markov chain whose states are the worlds x, and whose stationary distribution is π(x). In the Metropolis-Hastings (M-H) method, transitions in the Markov chain are constructed in two steps. First, given the current state x, a candidate next state x‧ is generated from a proposal distribution q(x‧ | x), which may be (more or less) arbitrary. Second, the transition to x‧ is not automatic, but occurs with an acceptance probability—α(x‧ | x) = min(1, π(x‧)q(x | x‧)/π(x)q(x‧ | x)). The seismic event model outlined in our companion abstract is quite similar to those used in multitarget tracking, for which MCMC has proved very effective. In this model, each world x is defined by a collection of events, a list of properties characterizing those events (times, locations, magnitudes, and types), and the association of each event to a set of observed detections. The target distribution π(x) = P(x | y), the posterior distribution over worlds x given the observed waveform data y at all stations. Proposal distributions then implement several types of moves between worlds. For example, birth moves create new events; death moves delete existing events; split moves partition the detections for an event into two new events; merge moves combine event pairs; swap moves modify the properties and assocations for pairs of events. Importantly, the rules for

  19. Asteroid orbital inversion using uniform phase-space sampling

    NASA Astrophysics Data System (ADS)

    Muinonen, K.; Pentikäinen, H.; Granvik, M.; Oszkiewicz, D.; Virtanen, J.

    2014-07-01

    a set of virtual observations; second, corresponding virtual least-squares orbital elements are derived using the Nelder-Mead downhill simplex method; third, repeating the procedure two times allows for a computation of a difference for two sets of virtual orbital elements; and, fourth, this orbital-element difference constitutes a symmetric proposal in a random-walk Metropolis-Hastings algorithm, avoiding the explicit computation of the proposal p.d.f. In a discrete approximation, the allowed proposals coincide with the differences that are based on a large number of pre-computed sets of virtual least-squares orbital elements. The virtual-observation MCMC method is thus based on the characterization of the relevant volume in the orbital-element phase space. Here we utilize MCMC to map the phase-space domain of acceptable solutions. We can make use of the proposal p.d.f.s from the MCMC ranging and virtual-observation methods. The present phase-space mapping produces, upon convergence, a uniform sampling of the solution space within a pre-defined χ^2-value. The weights of the sampled orbital elements are then computed on the basis of the corresponding χ^2-values. The present method resembles the original ranging method. On one hand, MCMC mapping is insensitive to local extrema in the phase space and efficiently maps the solution space. This is somewhat contrary to the MCMC methods described above. On the other hand, MCMC mapping can suffer from producing a small number of sample elements with small χ^2-values, in resemblance to the original ranging method. We apply the methods to example near-Earth, main-belt, and transneptunian objects, and highlight the utilization of the methods in the data processing and analysis pipeline of the ESA Gaia space mission.

  20. Frictional properties of DFDP-1 Alpine Fault rocks under hydrothermal conditions and high shear strain

    NASA Astrophysics Data System (ADS)

    Niemeijer, André R.; Boulton, Carolyn; Toy, Virginia; Townend, John; Sutherland, Rupert

    2015-04-01

    has occurred. Thus, depending on the background (nucleation) strain rate, our data indicate that the Alpine Fault should be able to generate earthquakes at all temperatures above room temperature. However, at the highest temperature investigated (600 oC), the transition to velocity-weakening is postponed to slip rates above 10 mm/s (strain rate ~10-2 s-1). This observation, combined with the absence of strength recovery after long holds, suggests that seismic slip may propagate into regions of the fault unlikely to nucleate earthquakes. We propose that in our porous gouges, thermally activated processes operate simultaneously with granular flow, postponing ductile flow to higher temperatures or lower strain rates. Sutherland, R., V.G. Toy, J. Townend, S.C. Cox, J.D. Eccles, D.R. Faulkner, D.J. Prior, R.J.Norris, E. Mariani, C. Boulton, B.M. Carpenter, C.D. Menzies, T.A. Little, M. Hasting, G.De Pascale, R.M. Langridge, H.R. Scott, Z. Reid-Lindroos, B. Fleming (2012), Drilling reveals fluid control on architecture and rupture of the Alpine Fault, New Zealand, Geology,40, 1143-1146, doi:10.1130/G33614.1. Toy, V.G., Craw, D., Cooper, A.F., and R.J. Norris (2010), Thermal regime in the central Alpine Fault zone, New Zealand: Constraints from microstructures, biotite chemistry and fluid inclusion data, Tectonophysics, doi:10.1016/j.tecto.2009.12.013

  1. The importance of being informed

    NASA Astrophysics Data System (ADS)

    Draganova, Tamara

    2013-04-01

    other schools in the region and the country. Campaigns were reflected in regional and national media. However, the capital invested in the young people is our responsibility - students, teachers and research workers, parents and citizens should be informed. And this is the power of us all today in order to face the future calmly and confidently, with the knowledge, attitudes and respect for our planet Earth. And we all, teachers are obliged and responsible to be conductors of Geosciences in the classroom today, for the future of our children... "If thou hast Knowledge, let others light their candle at thine..." Thomas Fuller

  2. EDITORIAL: Focus on Quantum Information and Many-Body Theory

    NASA Astrophysics Data System (ADS)

    Eisert, Jens; Plenio, Martin B.

    2010-02-01

    and F Verstraete SIMULATION AND DYNAMICS A quantum differentiation of k-SAT instances B Tamir and G Ortiz Classical Ising model test for quantum circuits Joseph Geraci and Daniel A Lidar Exact matrix product solutions in the Heisenberg picture of an open quantum spin chain S R Clark, J Prior, M J Hartmann, D Jaksch and M B Plenio Exact solution of Markovian master equations for quadratic Fermi systems: thermal baths, open XY spin chains and non-equilibrium phase transition Tomaž Prosen and Bojan Žunkovič Quantum kinetic Ising models R Augusiak, F M Cucchietti, F Haake and M Lewenstein ENTANGLEMENT AND SPECTRAL PROPERTIES Ground states of unfrustrated spin Hamiltonians satisfy an area law Niel de Beaudrap, Tobias J Osborne and Jens Eisert Correlation density matrices for one-dimensional quantum chains based on the density matrix renormalization group W Münder, A Weichselbaum, A Holzner, Jan von Delft and C L Henley The invariant-comb approach and its relation to the balancedness of multipartite entangled states Andreas Osterloh and Jens Siewert Entanglement scaling of fractional quantum Hall states through geometric deformations Andreas M Läuchli, Emil J Bergholtz and Masudul Haque Entanglement versus gap for one-dimensional spin systems Daniel Gottesman and M B Hastings Entanglement spectra of critical and near-critical systems in one dimension F Pollmann and J E Moore Macroscopic bound entanglement in thermal graph states D Cavalcanti, L Aolita, A Ferraro, A García-Saez and A Acín Entanglement at the quantum phase transition in a harmonic lattice Elisabeth Rieper, Janet Anders and Vlatko Vedral Multipartite entanglement and frustration P Facchi, G Florio, U Marzolino, G Parisi and S Pascazio Entropic uncertainty relations—a survey Stephanie Wehner and Andreas Winter Entanglement in a spin system with inverse square statistical interaction D Giuliano, A Sindona, G Falcone, F Plastina and L Amico APPLICATIONS Time-dependent currents of one-dimensional bosons

  3. Seismic imaging of major tectonic features in the crust of Phanerozoic eastern Australia

    NASA Astrophysics Data System (ADS)

    Finlayson, D. M.; Wake-Dyster, K. D.; Leven, J. H.; Johnstone, D. W.; Murray, C. G.; Harrington, H. J.; Korsch, R. J.; Wellman, P.

    1990-02-01

    England Fold Belt we interpret a high-angle geosuture extending through the crust (the Burunga-Mooki geosuture). Reactivation during late Palaeozoic-early Mesozoic times produced a series of reverse faults along the uplifted eastern margin of the trough. Some of these structures are tentatively considered to be positive flower structures above deeper faults with strike-slip movement. The geosuture separates regions with distinctly different Seismic fabrics and played an important role in the formation of the Bowen-Gunne-dah-Sydney Basin system. (5)Within the New England Fold Belt, crustal domains can be recognized associated with late Palaeozoic oroclinal bending and early Mesozoic trans-tensional basins. Major oroclinal bending of the upper crust in the west of the fold belt is interpreted above a mid-crustal detachment (the Texas detachment). In the central part of the fold belt, the Seismic data support a trans-tensional mechanism for the formation of Triassic basins with steeply dipping bounding faults. Under the east of the fold belt, an imbricate thrust stack/accretionary wedge is clearly imaged above a mid-crustal horizon (the Brisbane mid-crustal detachment). Upper crustal deformation appears to have occurred above this detachment. (6)From the Nebine Ridge to the coast, the Moho is clearly defined below a 3-km thick Moho transition zone. Hast of the Thomson Fold Belt, the Moho level is identified as a gently undulating feature at 36-38 km depth and probably re-established after the major late Palaeozoic tectonic events which formed the crust under the Taroom Trough and New England Fold Belt. This contrasts with the middle Palaeozoic lower crustal/Moho features which appear to be preserved under the Thomson Fold Belt. (7)The thickest crust under the Nebine Ridge (about 44 km) appears to be associated with lower crustal wedging from the east. There is an apparent thinning of the non-sedimentary crust under the deepest basin (Taroom Trough) of about 30% compared with

  4. EDITORIAL: Focus on Quantum Information and Many-Body Theory

    NASA Astrophysics Data System (ADS)

    Eisert, Jens; Plenio, Martin B.

    2010-02-01

    and F Verstraete SIMULATION AND DYNAMICS A quantum differentiation of k-SAT instances B Tamir and G Ortiz Classical Ising model test for quantum circuits Joseph Geraci and Daniel A Lidar Exact matrix product solutions in the Heisenberg picture of an open quantum spin chain S R Clark, J Prior, M J Hartmann, D Jaksch and M B Plenio Exact solution of Markovian master equations for quadratic Fermi systems: thermal baths, open XY spin chains and non-equilibrium phase transition Tomaž Prosen and Bojan Žunkovič Quantum kinetic Ising models R Augusiak, F M Cucchietti, F Haake and M Lewenstein ENTANGLEMENT AND SPECTRAL PROPERTIES Ground states of unfrustrated spin Hamiltonians satisfy an area law Niel de Beaudrap, Tobias J Osborne and Jens Eisert Correlation density matrices for one-dimensional quantum chains based on the density matrix renormalization group W Münder, A Weichselbaum, A Holzner, Jan von Delft and C L Henley The invariant-comb approach and its relation to the balancedness of multipartite entangled states Andreas Osterloh and Jens Siewert Entanglement scaling of fractional quantum Hall states through geometric deformations Andreas M Läuchli, Emil J Bergholtz and Masudul Haque Entanglement versus gap for one-dimensional spin systems Daniel Gottesman and M B Hastings Entanglement spectra of critical and near-critical systems in one dimension F Pollmann and J E Moore Macroscopic bound entanglement in thermal graph states D Cavalcanti, L Aolita, A Ferraro, A García-Saez and A Acín Entanglement at the quantum phase transition in a harmonic lattice Elisabeth Rieper, Janet Anders and Vlatko Vedral Multipartite entanglement and frustration P Facchi, G Florio, U Marzolino, G Parisi and S Pascazio Entropic uncertainty relations—a survey Stephanie Wehner and Andreas Winter Entanglement in a spin system with inverse square statistical interaction D Giuliano, A Sindona, G Falcone, F Plastina and L Amico APPLICATIONS Time-dependent currents of one-dimensional bosons

  5. SPIG From Beginning To Today

    NASA Astrophysics Data System (ADS)

    Labat, J.

    2010-07-01

    physics of ionized gases should be done in a more organized manner. Already in the summer of 1964 the "Summer School on the Physics of Ionized Gases" has been held in Herceg Novi, small town on the Adriatic coast. Six internationally recognized lecturers were invited to give a series of lectures in various fields. These were: prof. J. D. Craggs (Univ. of Liverpool, UK, 3 lectures) prof. A. L. Cullen (Univ. of Sheffield, UK, 3 lectures), prof. Yu. H. Demkov (Univ. of Leningrad, 3 lectures), prof. A. von Engel (Univ. of Oxford, UK, 8 lectures), dr. R. Herman (Obs. de Paris, France, 2 lectures), prof. J. B. Hasted (Univ. College, London, UK, 6 lectures). They were actually the first real teachers for the young and growing generation of Yugoslav scientists working in the field of ionized gases, and their names should be praised with dignity and gratitude. Good results of this summer school suggested that the school of this type should be organized on a regular basis and possibly combined with the symposium. This idea has been accepted by all the participants and as a result of this idea in 1968 the first meeting in a long lasting series was held under the full name: "Yugoslav Symposium and International Summer School on the Physics of Ionized Gases", now known world wide as SPIG. Mainly foreign participants insisted that it should be held somewhere on the Adriatic coast. Until 1990, with the exception of XIV SPIG (held in Sarajevo) all were organized in an attractive summer resorts along Adriatic coast, on a regular, two year basis. Yugoslavia fell apart in 1991, and the regular 1992 term has been omitted. The renowned XVI SPIG meting has been held in Belgrade in spite of general crisis and isolation of newly formed Federal Republic of Yugoslavia. The next one, for the same reason, was also organized in Belgrade. The number of foreign participants dropped down sharply due to war surrounding and largely unsettled situation. However, the general situation in the country

  6. Salt-front movement in the Hudson River estuary, New York : simulations by one-dimensional flow and solute-transport models

    USGS Publications Warehouse

    de Vries, M. Peter; Weiss, L.A.

    2001-01-01

    The Hudson River is being considered for use as a supplemental source of water supply for New York City during droughts. One proposal entails withdrawal of Hudson River water from locations near Newburgh, Chelsea, or Kingston, but the extent to which this could cause the salt front to advance upstream to points where it could adversely affect community water supplies is unknown. The U.S. Geological Survey (USGS) one-dimensional Branch-Network Dynamic Flow model (BRANCH) was used in conjunction with the USGS one-dimensional Branched Lagrangian Solute-Transport Model (BLTM) to simulate the effect of five water-withdrawal scenarios on the salt-front location. The modeled reach contains 132 miles of the lower Hudson River between the Federal Dam at Troy and Hastings-on-Hudson (near New York City). The BRANCH model was calibrated and verified to 19 tidal-cycle discharge measurements made at 11 locations by conventional and acoustic Doppler current-profiler methods. Maximum measured instantaneous tidal flow ranged from 20,000 ft3/s (cubic feet per second) at Albany to 368,000 ft3/s at Tellers Point; daily-mean flow at Green Island near Troy ranged from 3,030 ft3/s to 45,000 ft3/s during the flow measurements. Successive ebb- and flood-flow volumes were measured and compared with computed volumes; daily-mean bias was -1.6 percent (range from -21.0 to +23.7 percent; 13.5 percent mean absolute error). Daily-mean deviation between simulated and measured stage at eight locations (from Bowline Point to Albany) over the 19 tidal-cycle measurements averaged +0.06 ft (range from -0.31 to +0.40 ft; 0.21 ft root mean square error, RMSE). These results indicate that the model can accurately simulate flow in the Hudson River under a wide range of flow, tide, and meteorological conditions. The BLTM was used to simulate chloride transport in the 61-mi reach from Turkey Point to Bowline Point under two seasonal conditions in 1990.one representing spring conditions of high inflow and low

  7. BOOK REVIEW: Seeking Ultimates. An Intuitive Guide to Physics

    NASA Astrophysics Data System (ADS)

    Brown, Neil

    2000-05-01

    : entropy. It is physicists who can benefit most from discarding mathematics and seeking intuitive understanding. It is often too easy to put the numbers into a formula, with little real comprehension of the underlying physics. For layman or physicist the book is hard work. It is not a volume to be read from cover to cover; each section needs to be considered and digested, with frequent turning backwards (or sometimes forwards) to other pages. Even then the outcome may leave questions that can only be answered by access to an academic library to look up some of the copious references to original papers (which, of course, do not eschew mathematics or make concessions to conceptual difficulties). Unfortunately the book is marred by an impression of haste and lack of care, leading to errors that should not have reached the final print. For example, a graph of increase of population with generation number is shown as and stated to be a straight line. It should be exponential. This sort of thing undermines confidence in the whole text. High temperature superconductivity may have a revolutionary effect on electrical machines in the future, but for the time being magnets for magnetic resonance imaging machines and the like still use the old superconductors. Amusing anecdotes make for interesting reading, but the one about Faraday is garbled: he had nothing to do with frogs' legs (that was Galvani), and the quip about taxing electricity one day, if not apocryphal, was made either to Peel or to Gladstone, not to the King. In at least one case a topic mentioned in the index and glossary does not appear on the stated page in the text, apparently having been cut out at a late stage. Personally I did not find the book satisfying, but others will differ. Especially when dealing with intuitive appreciation, what is straightforward to one person may be utterly opaque to another. Making physics comprehensible and conveying its fascination is a daunting and often thankless task, but a very

  8. In This Issue

    NASA Astrophysics Data System (ADS)

    1996-04-01

    acquisition of data has made these techniques desirable even at the high school level. Students who are used to surfing the Internet on their home computer are ready to collect information via PC in their school labs as well. Bindel (page 356) takes advantage of the Personal Science Laboratory, an affordable package of probes and software for PC interfacing, to provide an experiment using the eye-catching lightstick as its object. Students use two methods to determine the activation energy of the reaction that produces the luminescence and explore concepts of kinetics as well as learn about computer-interfaced experimentation. Addendum. The engaging photgraph of Linus Pauling on the cover of the January issue was taken by Joseph McNally and is copyright Joseph McNally Photography, 52 Villard Avenue, Hastings-on-Hudon, NY 10706.

  9. LCLS-II New Instruments Workshops Report

    SciTech Connect

    Baradaran, Samira; Bergmann, Uwe; Durr, Herrmann; Gaffney, Kelley; Goldstein, Julia; Guehr, Markus; Hastings, Jerome; Heimann, Philip; Lee, Richard; Seibert, Marvin; Stohr, Joachim; /SLAC

    2012-08-08

    The LCLS-II New Instruments workshops chaired by Phil Heimann and Jerry Hastings were held on March 19-22, 2012 at the SLAC National Accelerator Laboratory. The goal of the workshops was to identify the most exciting science and corresponding parameters which will help define the LCLS-II instrumentation. This report gives a synopsis of the proposed investigations and an account of the workshop. Scientists from around the world have provided short descriptions of the scientific opportunities they envision at LCLS-II. The workshops focused on four broadly defined science areas: biology, materials sciences, chemistry and atomic, molecular and optical physics (AMO). Below we summarize the identified science opportunities in the four areas. The frontiers of structural biology lie in solving the structures of large macromolecular biological systems. Most large protein assemblies are inherently difficult to crystallize due to their numerous degrees of freedom. Serial femtosecond protein nanocrystallography, using the 'diffraction-before-destruction' approach to outrun radiation damage has been very successfully pioneered at LCLS and diffraction patterns were obtained from some of the smallest protein crystals ever. The combination of femtosecond x-ray pulses of high intensity and nanosized protein crystals avoids the radiation damage encountered by conventional x-ray crystallography with focused beams and opens the door for atomic structure determinations of the previously largely inaccessible class of membrane proteins that are notoriously difficult to crystallize. The obtained structures will allow the identification of key protein functions and help in understanding the origin and control of diseases. Three dimensional coherent x-ray imaging at somewhat lower resolution may be used for larger objects such as viruses. The chemistry research areas of primary focus are the predictive understanding of catalytic mechanisms, with particular emphasis on photo- and

  10. SPIG From Beginning To Today

    NASA Astrophysics Data System (ADS)

    Labat, J.

    2010-07-01

    physics of ionized gases should be done in a more organized manner. Already in the summer of 1964 the "Summer School on the Physics of Ionized Gases" has been held in Herceg Novi, small town on the Adriatic coast. Six internationally recognized lecturers were invited to give a series of lectures in various fields. These were: prof. J. D. Craggs (Univ. of Liverpool, UK, 3 lectures) prof. A. L. Cullen (Univ. of Sheffield, UK, 3 lectures), prof. Yu. H. Demkov (Univ. of Leningrad, 3 lectures), prof. A. von Engel (Univ. of Oxford, UK, 8 lectures), dr. R. Herman (Obs. de Paris, France, 2 lectures), prof. J. B. Hasted (Univ. College, London, UK, 6 lectures). They were actually the first real teachers for the young and growing generation of Yugoslav scientists working in the field of ionized gases, and their names should be praised with dignity and gratitude. Good results of this summer school suggested that the school of this type should be organized on a regular basis and possibly combined with the symposium. This idea has been accepted by all the participants and as a result of this idea in 1968 the first meeting in a long lasting series was held under the full name: "Yugoslav Symposium and International Summer School on the Physics of Ionized Gases", now known world wide as SPIG. Mainly foreign participants insisted that it should be held somewhere on the Adriatic coast. Until 1990, with the exception of XIV SPIG (held in Sarajevo) all were organized in an attractive summer resorts along Adriatic coast, on a regular, two year basis. Yugoslavia fell apart in 1991, and the regular 1992 term has been omitted. The renowned XVI SPIG meting has been held in Belgrade in spite of general crisis and isolation of newly formed Federal Republic of Yugoslavia. The next one, for the same reason, was also organized in Belgrade. The number of foreign participants dropped down sharply due to war surrounding and largely unsettled situation. However, the general situation in the country

  11. Oroclines in the Tasmanides

    NASA Astrophysics Data System (ADS)

    Musgrave, Robert J.

    2015-11-01

    secondary. In contrast to the other orogens, consensus that at least part of the curvature in the Palaeozoic to Triassic New England Orogen is oroclinal has been broad, although not universal. There remains substantial debate over the number of hinges (from two to four) and mechanism. Palaeomagnetic poles have previously been cited as evidence of rotation of blocks within the orocline, but this paper presents the first formal palaeomagnetic orocline test, which is positive for the Manning and Texas hinges. A palaeocurrent orocline test of the Manning hinge, in younger rocks than the palaeomagnetic sample, is negative, constraining rotation in the southern, Manning hinge to the Carboniferous before 322 Ma, while rotation in the northern, Texas hinge appears to be latest Carboniferous or Permian. The existence of a Hastings hinge is questionable, but if real, its rotation also appears to be younger than that of the Manning hinge. Thick-skinned, secondary rotation of the hinges of the New England orocline appears to have been diachronous.

  12. Software Uncertainty in Integrated Environmental Modelling: the role of Semantics and Open Science

    NASA Astrophysics Data System (ADS)

    de Rigo, Daniele

    2013-04-01

    . Semantic Array Programming for Environmental Modelling: Application of the Mastrave library. In: Seppelt, R., Voinov, A. A., Lange, S., Bankamp, D. (Eds.), International Environmental Modelling and Software Society (iEMSs) 2012 International Congress on Environmental Modelling and Software. Managing Resources of a Limited Planet: Pathways and Visions under Uncertainty, Sixth Biennial Meeting. pp. 1167-1176. http://www.iemss.org/iemss2012/proceedings/D3_1_0715_deRigo.pdf de Rigo, D., 2012. Semantic Array Programming with Mastrave - Introduction to Semantic Computational Modelling. http://mastrave.org/doc/MTV-1.012-1 Free Software Foundation, 2012. What is free software? http://www.gnu.org/philosophy/free-sw.html (revision 1.118 archived at http://www.webcitation.org/6DXqCFAN3 ) Stallman, R. M., 2009. Viewpoint: Why "open source" misses the point of free software. Communications of the ACM 52 (6), 31-33. http://dx.doi.org/10.1145/1516046.1516058 (free access version: http://www.gnu.org/philosophy/open-source-misses-the-point.html ) Lempert, R., Schlesinger, M. E., Jul. 2001. Climate-change strategy needs to be robust. Nature 412 (6845), 375. http://dx.doi.org/10.1038/35086617 Shell, K. M., Nov. 2012. Constraining cloud feedbacks. Science 338 (6108), 755-756. http://dx.doi.org/10.1126/science.1231083 van der Sluijs, J. P., 2012. Uncertainty and dissent in climate risk assessment: A Post-Normal perspective. Nature and Culture 7 (2), 174-195. http://dx.doi.org/10.3167/nc.2012.070204 Lenton, T. M., Held, H., Kriegler, E., Hall, J. W., Lucht, W., Rahmstorf, S., Schellnhuber, H. J., Feb. 2008. Tipping elements in the earth's climate system. Proceedings of the National Academy of Sciences 105 (6), 1786-1793. http://dx.doi.org/10.1073/pnas.0705414105 Hastings, A., Wysham, D. B., Apr. 2010. Regime shifts in ecological systems can occur with no warning. Ecology Letters 13 (4), 464-472. http://dx.doi.org/10.1111/j.1461-0248.2010.01439.x Barnosky, A. D., Hadly, E. A., Bascompte, J

  13. Once a myth, now an object of study - How the perception of comets has changed over the centuries

    NASA Astrophysics Data System (ADS)

    2004-02-01

    symbol of the prophet’s empowerment. Or again Luke 21:11: “And great earthquakes shall be in divers places, and famines, and pestilences; and fearful sights and great signs shall there be from heaven.” In 1066, Halley’s Comet appeared to many as a harbinger of the Norman conquest of Britain, so vividly portrayed in the Bayeux tapestry, with its scenes from the Battle of Hastings. The decisive step towards overturning the view that comets are atmospheric phenomena was taken in 1577 by Danish astronomer, Tycho Brahe. For two and a half months he observed from his observatory in Uranienburg the progress of a comet across the heavens. Relying on the phenomenon of the daily parallax - an apparent “shuddering” motion of heavenly bodies in fact attributable to the observer’s position on the revolving Earth - he was able to establish that the comet had to be located beyond the lunar orbit. Halley discovers an elliptical orbit The scientific description of comets took another major step forward in 1705 thanks to the work of the British astronomer and physicist, Edmond Halley, a friend and patron of Isaac Newton. Investigating recorded comet measurements, he observed that the orbits of a number of bright comets were very similar: his own calculation of the orbit of a comet observed in 1682 coincided with the data recorded by Johannes Kepler in 1607 and by Apianus in 1531. He concluded that various comet observations were attributable to one and the same comet. Halley was proved right when in December 1758, the comet whose return he had predicted, thenceforth named after him, did indeed make a repeat appearance. This confirmed his theory that apparently parabolic comet orbits were in fact “simply” sections of one enormous elliptical orbit. Since then observations recorded in China in 240 BC have been identified as relating to a sighting of Halley’s comet, the oldest known document dealing with this phenomenon. What was described in the Bible as a sign from God

  14. Farmyard Manure and Fertilizer Effects on Seed Potato (Solanum tuberosum L.) Yield in Green House Production

    NASA Astrophysics Data System (ADS)

    László, M.

    2009-04-01

    %. Entre as misturas 1 e 2, foi melhor a 2. (80% latossolo vermelho novo, 10% palha de arroz queimado, 10% esterco de curral). Examinando-se 15 fatores, entre 11 casos afirmou-se a mistura como para melhor que a mistura 1. (70% latossolo vermelho novo, 20% palha de arroz queimado, 10% esterco de curral). Em caso de número de tuberculos 0-20 mm com a mistura 2. foi possivel aumentar geralmente os números de tuberculos em 77% que a mistura padrão. Efeitos de adubação 1. Área da folhas por planta entre manejo foi melhor de modo significativo a doságem de 3.6 grama vaso-1 adubo complexo (3103 cm2 plantas-1). 2. Peso fresco da folhas e de hastes por plantas as tendencias foram parecidos com o da área de folhas. 3. Peso fresco de raizis por planta até 7.2 grama vaso-1 diminuiu depois aumentou. 4. Peso fresco total de tuberculos por planta as crescentes doságens de um modo forte diminuiram a produção de tuberculos de 0 e 18.0 grama vaso-1 em 160% em os dois caso da mistura. 5. Peso de fitomassa fresco por planta foi melhor a 3.6 g vaso-1 (239 grama planta-1 em médio da dois mistura), depois os dados diminuirám. 6. Produção de biomassa fresco por planta a maxima produção (188 grama planta-1) foi obtida com 3.6 grama vaso-1. Deste ponto de modo forte caiu a produção. 7. Peso da matéria seca de folhas, hastes e raizis por planta somente em caso de mistura padrão o resultado foi significativo em relação aos outros tratamentos. 8. Péso da matéria seca de tuberculos total por planta modo significativo diminuiu a produção (0 e 18.0 grama vaso-1 = 360%) em médio da duas misturas. 9. Biomassa produção de materia seca por planta modo significativo diminuiu para efeito de alta dosagens de adubo complexo (0 e 18.0 grama vaso-1 = 158%) em médio da duas misturas. 10. Peso fresco de tuberculos com 0-20 mm as crescentes dosagens de 0 e 18.0 grama vaso-1 diminuiram a produção em 213% em médio da duas misturas. 11. Peso fresco de tuberculos com 20 mm-1 as