3,642 research outputs found

    Full Open Population Capture-Recapture Models with Individual Covariates

    Full text link
    Traditional analyses of capture-recapture data are based on likelihood functions that explicitly integrate out all missing data. We use a complete data likelihood (CDL) to show how a wide range of capture-recapture models can be easily fitted using readily available software JAGS/BUGS even when there are individual-specific time-varying covariates. The models we describe extend those that condition on first capture to include abundance parameters, or parameters related to abundance, such as population size, birth rates or lifetime. The use of a CDL means that any missing data, including uncertain individual covariates, can be included in models without the need for customized likelihood functions. This approach also facilitates modeling processes of demographic interest rather than the complexities caused by non-ignorable missing data. We illustrate using two examples, (i) open population modeling in the presence of a censored time-varying individual covariate in a full robust-design, and (ii) full open population multi-state modeling in the presence of a partially observed categorical variable

    Molecular simulation of the phase behavior of noble gases using accurate two-body and three-body intermolecular potentials

    Get PDF
    Gibbs ensemble Monte Carlo simulations are reported for the vapor- liquid phase coexistence of argon, krypton, and xenon. The calculations employ accurate two-body potentials in addition to contributions from three-body dispersion interactions resulting from third-order triple-dipole, dipole-dipole-quadrupole, dipole- quadrupole-quadrupole, quadrupole-quadrupole-quadrupole, and fourth- order triple- dipole terms. It is shown that vapor-liquid equilibria are affected substantially by three-body interactions. The addition of three-body interactions results in good overall agreement of theory with experimental data. In particular, the subcritical liquid- phase densities are predicted accurately. (C) 1999 American Institute of Physics. S0021- 9606(99)50728-9

    Role of zinc in bulk precipitation from the steaming process of potable water

    Get PDF
    Water chemistry plays an important role in fouling kinetics and morphology. This work investigates the influence of zinc cations in potable water, specifically the kinetics of crystallisation and their effect on the fouling layer during the operation of a batch steam generator system and a once-through flow system. The kinetics of precipitation in the batch crystalliser were examined based on the change in concentration of the foulants, while the fouling resistance approach was used in the flow system. In addition, morphological testing was carried out using Scanning Electron Microscopy, Powder X-ray Diffraction, and Energy dispersive X-ray. The findings showed that the precipitation rate of calcium carbonate decreases with the increase in zinc ions until reaching the zinc carbonate supersaturation in the water due to water evaporation. Regarding morphology, co-precipitation of zinc carbonate was observed at high zinc concentrations. As a result, a double effect was observed where zinc both retarded and enhanced fouling over time. The fouling rate in the flow system decreased as the zinc concentration increased. Zinc ions were found to influence the morphology of deposit minerals significantly. Moreover, the surface deposition of zinc salts increased with the solution content of zinc

    The politics of punishment in colonial Mauritius, 1766-1887

    Get PDF
    The history of imprisonment in British colonial Mauritius is intertwined with its political economy, most especially the relationship between metropolitan government and plantation owners. Whether labour was predominantly enslaved, apprenticed or indentured, incarceration was part of a broader process through which the regulation of the colonial workforce was taken from the private to the public sphere and became associated with economic development. Nevertheless, prisoners both challenged and used prison regimes as vehicles for the improvement of their lives. Mauritian jails were intensely political arenas in which the changing nature of colonial relations and the regulation of labour was both expressed and contested

    Electronic structure of NiS1x_{1-x}Sex_x across the phase transition

    Full text link
    We report very highly resolved photoemission spectra of NiS(1-x)Se(x) across the so-called metal-insulator transition as a function of temperature as well as composition. The present results convincingly demonstrate that the low temperature, antiferromagnetic phase is metallic, with a reduced density of states at EF_F. This decrease is possibly due to the opening of gaps along specific directions in the Brillouin zone caused by the antiferromagnetic ordering.Comment: Revtex, 4 pages, 3 postscript figure

    The pH-dependence of lipid-mediated antimicrobial peptide resistance in a model Staphylococcal plasma membrane: a two-for-one mechanism of epithelial defence circumvention.

    Get PDF
    The mechanisms of membrane defence by lysylphosphatidylglycerol (LPG), were investigated using synthetic biomimetic mono- and bilayer models of methicillin resistant S. aureus ST239 TW, based on its lipid composition in both pH 7.4 (28% LPG) and pH 5.5 (51% LPG) cultures. These models incorporated a stable synthetic analogue of LPG (3adLPG) to facilitate long-duration biophysical studies, which were previously limited by the lability native LPG. Both increased 3adLPG content and full headgroup ionization at pH 5.5, increased bilayer order and dampened overall charge, via the formation of neutral ion pairs with anionic lipids. Ion pair formation in air/liquid interface lipid monolayers elicited a significant condensing effect, which correlated with the inhibition of subphase-injected magainin 2 F5W partitioning. In fluid phase lipid vesicles, increasing the proportion of 3adLPG from 28 to 51 mol% completely inhibited the adoption of the membrane-active ?-helical conformation of the peptide, without the need for full headgroup ionization. Neutron reflectivity measurements performed on biomimetic PG/3adLPG fluid floating bilayers, showed a significant ordering effect of mild acidity on a bilayer containing 30 mol% 3adLPG, whilst peptide binding/partitioning was only fully inhibited in a bilayer with 55 mol% 3adLPG at pH 5.5. These findings are discussed with respect to the roles of LPG in resistance to human epithelial defences in S. aureus and the continued evolution of this opportunistic pathogen’s virulence

    Prospectus, November 29, 1989

    Get PDF
    https://spark.parkland.edu/prospectus_1989/1030/thumbnail.jp
    corecore