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The current study examined a stage-based alcohol use trajectory model to test for potential causal effects of earlier drinking milestones on later drinking milestones in a combined sample of two cohorts of Australian monozygotic and same-sex dizygotic twins (N = 7,398, age M = 30.46, SD = 2.61, 61% male, 56% monozygotic twins). Ages of drinking, drunkenness, regular drinking, tolerance, first nontolerance alcohol use disorder symptom, and alcohol use disorder symptom onsets were assessed retrospectively. Ages of milestone attainment (i.e., age-of-onset) and time between milestones (i.e., time-to-event) were examined via frailty models within a multilevel discordant twin design. For age-of-onset models, earlier ages of onset of antecedent drinking milestones increased hazards for earlier ages of onset for more proximal subsequent drinking milestones. For the time-to-event models, however, earlier ages of onset for the “starting” milestone decreased risk for a shorter time period between the starting and the “ending” milestone. Earlier age of onset of intermediate milestones between starting and ending drinking milestones had the opposite effect, increasing risk for a shorter time period between the starting and ending milestones. These results are consistent with a causal effect of an earlier age of drinking milestone onset on temporally proximal subsequent drinking milestones.
Language use is of increasing interest in the study of mental illness. Analytical approaches range from phenomenological and qualitative to formal computational quantitative methods. Practically, the approach may have utility in predicting clinical outcomes. We harnessed a real-world sample (blog entries) from groups with psychosis, strong beliefs, odd beliefs, illness, mental illness and/or social isolation to validate and extend laboratory findings about lexical differences between psychosis and control subjects.
We describe the results of two experiments using Linguistic Inquiry and Word Count software to assess word category frequencies. In experiment 1, we compared word use in psychosis and control subjects in the laboratory (23 per group), and related results to subject symptoms. In experiment 2, we examined lexical patterns in blog entries written by people with psychosis and eight comparison groups. In addition to between-group comparisons, we used factor analysis followed by clustering to discern the contributions of strong belief, odd belief and illness identity to lexical patterns.
Consistent with others’ work, we found that first-person pronouns, biological process words and negative emotion words were more frequent in psychosis language. We tested lexical differences between bloggers with psychosis and multiple relevant comparison groups. Clustering analysis revealed that word use frequencies did not group individuals with strong or odd beliefs, but instead grouped individuals with any illness (mental or physical).
Pairing of laboratory and real-world samples reveals that lexical markers previously identified as specific language changes in depression and psychosis are probably markers of illness in general.
The results presented here are from an ongoing mid-infrared imaging study of PPNe and PNe, using MIRAC2 the UA/SAO mid-IR camera. Our 8-21 μm observations have a spatial resolution of about 0.7″ to 1.5″, and a pixel scale of 0.25″/pixel (at UKIRT) or 0.34″/pixel (at IRTF). The high S/N and good spatial sampling in our images of IRAS 22272+5435 and IRAS 07134+1005 allow us to construct temperature and optical depth maps. Using our 11.7μm and 20.6μm images we also construct maps which isolate the 11.3μm (UIR) and 21μm emission features (Justannont et al. 1995). As a second part of this project, we are modelling the dust emission from PPNe and young PNe, using a axisymmetrical radiative transfer code.
The dispersion relation of electrostatic waves with phase velocities smaller than the electron thermal velocity is investigated in relativistic temperature plasmas. The model equations are the electron relativistic collisionless hydrodynamic equations and the ion non-relativistic Vlasov equation, coupled to the Poisson equation. The complex frequency of electrostatic modes are calculated numerically as a function of the relevant parameters kλDe and ZTe/Ti where k is the wavenumber, λDe, the electron Debye length, Te and Ti the electron and ion temperature, and Z, the ion charge number. Useful analytic expressions of the real and imaginary parts of frequency are also proposed. The non-relativistic results established in the literature from the kinetic theory are recovered and the role of the relativistic effects on the dispersion and the damping rate of electrostatic modes is discussed. In particular, it is shown that in highly relativistic regime the electrostatic waves are strongly damped.
We survey the present status and potentialities of diagnostics for arbitrary magnetized plasmas of inertial confinement fusion concern. These diagnostics include: Faraday rotation, inverse Faraday effect, Thomson scattering, Stark–Zeeman line broadening as well as proton stopping for any ratio, of the particles plasma frequency to cyclotron frequency. This presentation is timely motivated by recent experiments highlighting laser-produced kilo Teslas and nearly steady magnetic fields in inertial fusion plasmas. Positive synergies due to diagnostics combinations are also addressed.
Recently, we have proposed an experiment to test the persistence of the polarization in a fusion process (D+D→3He+n), using a powerful laser hitting a polarized HD target. The purpose of the present contribution is to examine in more detail the experimental constraints, to move from a principle proposal to a doable experiment. Some of the difficulties are as follows: Production of a windowless cryogenic HD target and target cryostat vacuum breakdown, identification of thermal fusion or accelerated deuterons, inducing nuclear reactions, and finally, a clear signature of the polarization persistence of the fused deuterons must be found. Those points will be reviewed and discussed in the scope of the new results presented at this conference.
Language use is often disrupted in patients with schizophrenia; novel
computational approaches may provide new insights.
To test word use patterns as markers of the perceptual, cognitive and
social experiences characteristic of schizophrenia.
Word counting software was applied to first-person accounts of
schizophrenia and mood disorder.
More third-person plural pronouns (‘they’) and fewer first-person
singular pronouns (‘I’) were used in schizophrenia than mood disorder
accounts. Schizophrenia accounts included fewer words related to the body
and ingestion, and more related to religion. Perceptual and causal
language were negatively correlated in schizophrenia accounts but
positively correlated in mood disorder accounts.
Differences in pronouns suggest decreased self-focus or perhaps even an
understanding of self as other in schizophrenia. Differences in how
perceptual and causal words are correlated suggest that long-held
delusions represent a decreased coupling of explanations with sensory
experience over time.
The effects of a radiation field (RF) on the interaction process of a relativistic electron beam (REB) with an electron plasma are investigated. The stopping power of the test electron averaged with a period of the RF has been calculated assuming an underdense plasma, ω0 > ωp, where ω0 is the frequency of the RF and ωp is the plasma frequency. In order to highlight the effect of the radiation field we present a comparison of our analytical and numerical results obtained for nonzero RF with those for vanishing RF. In particular, it has been shown that the weak RF increases the mean energy loss for small angles between the velocity of the REB and the direction of polarization of the RF while decreasing it at large angles. Furthermore, the relative deviation of the energy loss from the field-free value is strongly reduced with increasing the beam energy. Special case of the parallel orientation of the polarization of the RF with respect to the beam velocity has been also considered. At high-intensities of the RF two extreme regimes have been distinguished when the excited harmonics cancel effectively each other reducing strongly the energy loss or increasing it due to the constructive interference. Moreover, it has been demonstrated that the energy loss of the ultrarelativistic electron beam increases systematically with the intensity of the RF exceeding essentially the field-free value.
A theoretical model for electrons in the conduction band intend to investigate the optical breakdown threshold in femtosecond laser pulse-fused silica interaction is presented. The model is derived from a rate equation that includes the avalanche and multi-photon ionization processes of Thornber and Keldysh, respectively, and also the three-body and exciton recombination mechanisms. In addition, the time evolution of electron mean energy is also considered through the energy balance equation. The mean energy acts as a trigger for the avalanche mechanism. The evolution of electron density profiles is calculated and discussed with respect to the ionization and recombination mechanisms. The results for the fluence threshold as a function of the pulse duration fall in good agreement with the experimental data reported in the literature.
Solid phase physical and chemical characterization methods have been used in an ongoing study of residual wastes from several single-shell underground waste tanks at the U.S. Department of Energy's Hanford Site in southeastern Washington State. Because these wastes are highly-radioactive dispersible powders and are chemically-complex assemblages of crystalline and amorphous solids that contain contaminants as discrete phases and/or co-precipitated within oxide phases, their detailed characterization offers an extraordinary technical challenge. X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive x-ray spectroscopy (SEM/EDS) are the two principal methods used, along with a limited series of analyses by synchrotron-based methods, to characterize solid phases and their contaminant associations in these wastes. Depending on the specific tank, numerous solids (e.g., èejkaite; Na2U2O7; clarkeite; gibbsite; böhmite; dawsonite; cancrinite; Fe oxides such as hematite, goethite, and maghemite; rhodochrosite; lindbergite; whewellite; nitratine; and several amorphous phases) have been identified in residual wastes studied to date. Because many contaminants of concern are heavy elements, SEM analysis using the backscattered electron (BSE) signal has proved invaluable in distinguishing phases containing elements, such as U and Hg, within the complex assemblage of particles that make up each waste. XRD, SEM/EDS, and synchrotron-based methods provide different, but complimentary characterization data about the morphologies, crystallinity, particle sizes, surface coatings, and compositions of phases in these wastes. The impact of these techniques is magnified when each is used in an iterative fashion to help interpret the results from the other analysis methods and identify additional, more focused analyses.
The inelastic interaction between heavy ions and an electron plasma in the presence of an intense radiation field (RF) is investigated. The stopping power of the test ion averaged with a period of the RF has been calculated assuming that ω0 > ωp, where ω0 is the frequency of the RF and ωp is the plasma frequency. In order to highlight the effect of the radiation field we present a comparison of our analytical and numerical results obtained for nonzero RF with those for vanishing RF. It has been shown that the RF may strongly reduce the mean energy loss for slow ions while increasing it at high–velocities. Moreover, it has been shown, that acceleration of the projectile ion due to the RF is expected at high–velocities and in the high–intensity limit of the RF, when the quiver velocity of the plasma electrons exceeds the ion velocity.
We propose an experiment to test the persistence of the polarization in a fusion process, using a terawatt laser hitting a polarized high density (HD) target. The polarized protons and deuterons heated in the plasma induced by the laser have a significant probability to fuse producing a 3He and a γ-ray or a neutron in the final state. The angular distribution of the radiated γ-rays and the change in the corresponding total cross-section are related to the polarization persistence, but the resulting signal turns out to be weak. By comparison, the neutrons are produced hadronically with a larger cross-section and it is much easier to detect them. A significant reduction of the cross-section by parallel polarization of the deuterons as well as a structured angular distribution of the emitted neutrons is reliably predicted by the theory. Therefore, it is expected that the corresponding signal on the neutron counting rate could be seen experimentally. Magnetic fields, relaxation times and possibilities of local investigations are discussed.
We consider ion projectile slowing down at low velocity Vp < Vthe, target thermal electron velocity, in a strongly coupled and de-mixing H-He ionic mixture. It is investigated in terms of quasi-static and critical charge-charge structure factors. Non-polarizable as well as polarizable partially degenerate electron backgrounds are given attention. The low velocity ion slowing down turns negative in the presence of long wavelength and low frequency hydromodes, signaling a critical de-mixing. This process documents an energy transfer from target ion plasma to the incoming ion projectile.
The structural evolution of Au/Ni multilayers (with an increasing number of Ni monolayers (MLs)) has been investigated by HREM. As soon as the thickness of Ni becomes larger than 5 MLs, a structural change occurs which in fact has been predicted by numerical simulations. The deformation in the multilayer has been characterised by HREM image processing and has been related to the Ni profile. This profile has been compared to the chemical profile obtained by scanning PEELS analysis through the multilayer.
Inertial confinement fusion fast ignition at very high relativistic electron beam energy is systematically explored through a possible combination of various stopping mechanisms including strong Langmuir turbulence, elastic, and inelastic electron interactions with target particles. A specific attention is given to final state interaction through catalysis by negative pion.
Ion projectile stopping at velocity smaller than target electron thermal velocity in a strong magnetic field is investigated within a novel diffusion formulation, based on Green-Kubo integrands evaluated in magnetized one component plasma models, respectively, framed on target ions and electron. Analytic expressions are reported for slowing down orthogonal and parallel to an arbitrary large magnetic field, which are free from the usual uncertainties plaguing the standard perturbative derivations.
A massive fish-kill at a trout hatchery located below the discharge of a seasonally stratified impoundment provided a unique opportunity to examine mechanisms of toxicity (using in situ water) by means of a largescale experiment at the hatchery itself. In order to assess the relative impact on the fish of a number of water constituents such as heavy-metals and organic materials, a variety of dosing chemicals were employed within the hatchery. Fish tissue and blood samples were collected for histological and chemical analysis, respectively.
It was concluded that a combination of manganese and organic material (probably humic in nature) in reduced chemical states in discharges of bottom (hypolimnetic) waters of the impoundment during periods of minimum power-generation was responsible for the mortality. Parallels between the fish-kill under investigation and other reported causes of hypolimnetic water toxicity were also drawn. It would appear that the redox state and nature of organic materials present may control the mechanisms in the various fish-kill situations. Implications for other users of the water are currently under investigation in an expanded programme.