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Plasma radiative properties play a pivotal role both in nuclear fusion and astrophysics. They are essential to analyze and explain experiments or observations and also in radiative-hydrodynamics simulations. Their computation requires the generation of large atomic databases and the calculation, by solving a set of rate equations, of a huge number of atomic level populations in wide ranges of plasma conditions. These facts make that, for example, radiative-hydrodynamics in-line simulations be almost infeasible. This has lead to develop analytical expressions based on the parametrization of radiative properties. However, most of them are accurate only for coronal or local thermodynamic equilibrium. In this work we present a code for the parametrization of plasma radiative properties of mono-component plasmas, in terms of plasma density and temperature, such as radiative power loss, the Planck and Rosseland mean opacities and the average ionization, which is valid for steady-state optically thin plasmas in wide ranges of plasma densities and temperatures. Furthermore, we also present some applications of this parametrization such as the analysis of the optical depth and radiative character of plasmas, the use to perform diagnostics of the electron temperature, the determination of mean radiative properties for multicomponent plasmas and the analysis of radiative cooling instabilities in some kind of experiments on high-energy density laboratory astrophysics. Finally, to ease the use of the code for the parametrization, this one has been integrated in a user interface and brief comments about it are presented.
The hydrolysis of niobates in aqueous solutions has been studied as a function of pH and concentration. The process has been applied to the coprecipitation of PbNb2/3Mg1/3O3 leading to a low temperature synthesis of this ferroelectric relaxor ceramic. The effect of hydrolysis conditions such as the concentration of bases and acids used, their rate of addition, temperature and the nature of the precursor salts is described. The homogeneity of the precipitates has been characterized through infrared spectroscopy and X-ray diffraction techniques. The perovskite phase appears after heating at 350°C and is obtained as a pure phase above 750°C after one hour heat-treatment. Relaxor ceramics with high dielectric constant can be obtained by sintering above 1000°C. The process also has been successfully applied to the synthesis of other relaxor ceramic compositions such as PZN (PbNb2/3Zn1/3O3), PFN (PbNb1/2Fe1/2O3) as well as CdNb2O6 and MgNb2O6 compounds.
Thermally grown Si3N4 films in NH3 are known to have a higher dielectric constant and a higher N concentration than silicon oxynitrides, although they incorporate hydrogen atoms that induce hot electron carriers during subsequent high temperature processing. Further, a silicon nitride is difficult to grow over about 6 nm thick, due to self-limiting growth. One alternative is SiOxNy post-nitrided with NH3.
In this work, we study the scope of improvement of Ar annealed nitrided oxynitrides as a function of annealing temperature and duration. Secondary ion mass spectroscopy (SIMS) studies of the nitrogen and hydrogen profiles suggest increasing N and H removal with increasing annealing time and temperature. Electrical characterizations have been performed to determine the total charge (Qox) and interface trap (Dit) densities at different processing conditions, before and after the annealing step. Post-annealing steps are not found to yield improvements of the electrical properties of these dielectric films. Instead, sometimes Qox is even seen to increase (e.g., after a 30 min Ar anneal at 1000 °C). Therefore, an optimization of such annealing steps is essential in designing nanodielectrics with desired nitrogen amounts and N concentration profiles as well as in understanding related process-structure-function relationships.
A cross-sectional study on 32 different Belgian broiler farms was performed in 2007 and 2008 to identify risk factors for ceftiofur resistance in Escherichia coli. On each farm, one E. coli colony was isolated from 30 random birds. Following susceptibility testing of 14 antimicrobials, an on-farm questionnaire was used to obtain information on risk factors. Using a multilevel logistic regression model two factors were identified at the animal level: resistance to amoxicillin and to trimethoprim–sulfonamide. On the farm level, besides antimicrobial use, seven management factors were found to be associated with the occurrence of ceftiofur resistance in E. coli from broilers: poor hygienic condition of the medicinal treatment reservoir, no acidification of drinking water, more than three feed changes during the production cycle, hatchery of origin, breed, litter material used, and treatment with amoxicillin. This study confirms that not only on-farm antimicrobial therapy, but also management- and hatchery-related factors influence the occurrence of antimicrobial resistance.
Direct numerical simulations (DNSs) are used to investigate the drag-reducing performance of superhydrophobic surfaces (SHSs) in turbulent channel flow. SHSs combine surface roughness with hydrophobicity and can, in some cases, support a shear-free air–water interface. Slip velocities, wall shear stresses and Reynolds stresses are considered for a variety of SHS microfeature geometry configurations at a friction Reynolds number of Reτ ≈ 180. For the largest microfeature spacing studied, an average slip velocity over 75% of the bulk velocity is obtained, and the wall shear stress reduction is found to be nearly 40%. The simulation results suggest that the mean velocity profile near the superhydrophobic wall continues to scale with the wall shear stress but is offset by a slip velocity that increases with increasing microfeature spacing.
Damage of the intestinal epithelial barrier by xenobiotics or reactive oxygen species and a dysregulated immune response are both factors involved in the pathogenesis of inflammatory bowel diseases (IBD). Curcumin and rutin are polyphenolic compounds known to have antioxidant and anti-inflammatory activities, but their mechanism(s) of action are yet to be fully elucidated. Multidrug resistance gene-deficient (mdr1a− / − ) mice spontaneously develop intestinal inflammation, predominantly in the colon, with pathology similar to IBD, so this mouse model is relevant for studying diet–gene interactions and potential effects of foods on remission or development of IBD. The present study tested whether the addition of curcumin or rutin to the diet would alleviate colonic inflammation in mdr1a− / − mice. Using whole-genome microarrays, the effect of dietary curcumin on gene expression in colon tissue was also investigated. Twelve mice were randomly assigned to each of three diets (control (AIN-76A), control +0·2 % curcumin or control +0·1 % rutin) and monitored from the age of 7 to 24 weeks. Curcumin, but not rutin, significantly reduced histological signs of colonic inflammation in mdr1a− / − mice. Microarray and pathway analyses suggested that the effect of dietary curcumin on colon inflammation could be via an up-regulation of xenobiotic metabolism and a down-regulation of pro-inflammatory pathways, probably mediated by pregnane X receptor (Pxr) and peroxisome proliferator-activated receptor α (Ppara) activation of retinoid X receptor (Rxr). These results indicate the potential of global gene expression and pathway analyses to study and better understand the effect of foods in modulating colonic inflammation.
Radiative properties are fundamental for plasma diagnostics and hydro-simulations. For this reason, there is a high interest in their determination and they are a current topic of investigation both in astrophysics and inertial fusion confinement research. In this work a flexible computation package for calculating radiative properties for low and high Z optically thin and thick plasmas, both under local thermodynamic equilibrium and non-local thermodynamic equilibrium conditions, named RAPCAL is presented. This code has been developed with the aim of providing accurate radiative properties for low and medium Z plasmas within the context of detailed level accounting approach and for heavy elements under the detailed configuration accounting approach. In order to show the capabilities of the code, there are presented calculations of some radiative properties for carbon, aluminum, krypton and xenon plasmas under local thermodynamic and non-local thermodynamic equilibrium conditions.
In this work is accomplished the determination of the corona, local and non-local thermodynamic equilibrium regimes for optically thin carbon plasmas in steady state, in terms of the plasma density and temperature using the ABAKO code. The determination is made through the analysis of the plasma average ionization and ion and level populations. The results are compared whit those obtained applying Griem's criterion. Finally, it is made a brief analysis of the effects of the calculation of level populations assuming different plasma regimes in radiative properties, such as emissivities and opacities.
We describe a method of working on publicly available data to estimate disease prevalence in small geographic areas using Helicobacter pylori as a model infection. Using data from the Third National Health and Nutrition Examination Survey, risk parameters for H. pylori infection were obtained by logistic regression and validated by predicting 737·5 infections in an independent cohort with 736 observed infections. The prevalence of H. pylori infection in the San Francisco Bay Area was estimated with the probabilities obtained from a predictive logistic model, using risk parameters with individual-level 1990 U.S. Census data as input. Predicted H. pylori prevalence was also compared to gastric cancer incidence obtained from the Northern California Cancer Center and showed a positive correlation with gastric cancer incidence (P<0·001, R2=0·87), and no statistically significant association with other malignancies. By exclusively using publicly available data, these methods may be applied to selected conditions with strong demographic predictors.
In this work, we first presents a review of the work that research
teams have developed in collaboration in order to determine the optical
properties of plasmas during the recent years, and showing the
achievements reached. The second part of this paper is devoted to one of
these improvements, which is to include reabsorption of the radiation in
the calculations of dense optically thick plasmas in non-LTE conditions.
Two models recently developed for this purpose are presented. The
quantitative study was focused on aluminum plasmas, which was obtained
recently at LULI experiments.
We previously reported that 25% (108/441) of consecutive patients presenting to the emergency department (ED) of the Montreal Heart Institute with a chief complaint of chest pain suffered from panic disorder (PD). The purpose of the present study was to re-examine these patients (with and without PD) 2 years after their initial ED visit to determine their psychiatric and psychosocial status.
An interviewer, who was kept blind to patients’ initial medical and psychiatric diagnoses, attempted to contact all patients who participated in the initial study by phone. Patients who completed the phone interview were sent a battery of psychological questionnaires by mail.
A total of 301 (70%) patients completed the phone interview, and 228 (52%) patients completed the self-report questionnaires. Participants and non-participants did not differ with respect to age, gender, initial self-report scores, or initial cardiac or psychiatric diagnoses. At follow-up, significantly (p < 0.05) more PD+ than non-PD (PD–) patients reported: 1) chest pains in the last month (57% vs. 31%); 2) one or more ED consultations in the past year for chest pain (40% vs. 14%); 3) one or more hospitalizations in the past year (31% vs. 11%); and 4) perceiving their general health as “poor” (22% vs. 9%). PD+ patients displayed a significant (p < 0.05) worsening of their panic symptoms, agoraphobic avoidance, depression, and trait anxiety, and reported significantly (p < 0.05) greater suicidal ideation compared to PD– patients (32% vs. 9%). Of all PD+ patients, only 22% (18/82) reported receiving some form of mental health treatment for their symptoms.
Unrecognized and untreated PD has a chronic and disabling course. Greater efforts should be made to screen for PD in patients complaining of chest pain in EDs.
In this work, the Saha equation is solved using atomic data
provided by means of a new relativistic-screened hydrogenic
model based on analytical potentials to calculate the ionization
state and ion abundance for LTE iron plasmas. The plasma effects
on the atomic structure are taken into account by including
the classical continuum lowering correction of Stewart and Pyatt.
For high density, the Saha equation is modified to consider
the degeneration of free electrons using the Fermi–Dirac
statistics instead of the Maxwellian distribution commonly used.
The results are compared with more sophisticated self-consistent
In this work, a new analytical potential for studying ions
in excited configurations is presented, which is built up from
a parametric potential for ions in a ground state. It is used
to calculate atomic magnitudes of special importance in plasmas
such as total energies, energy levels, and transition energies,
for ions in excited configurations. The results are successfully
compared with those obtained with both self-consistent or
In this work, the Saha equation is solved using
atomic data provided by means of analytical potentials
to calculate the ionization state and ion abundances for
local thermodynamic equilibrium (LTE) plasmas of Al, Fe,
and Au. The plasma effects are taking into account using
an analytical potential which includes plasma effects.
The problem of the cut off partition functions in the Saha
equation is also analyzed using three different criteria.
Finally, some opacity calculations are performed.
A numerical model for opacity calculations by using a family of analytical potentials for each configuration in the plasma is presented. The obtained numerical opacity results with this model are compared with those obtained by using a self-consistent potential model.
Multiple neurotransmitter systems are affected in senile dementia of the Alzheimer's type (SDAT). Among them, acetylcholine has been most studied. It is now well accepted that the activity of the enzyme, choline acetyltransferase (ChAT) is much decreased in various brain regions including the frontal and temporal cortices, hippocampus and nucleus basalis of Meynert (nbm) in SDAT. Cortical M2-muscarinic and nicotinic cholinergic receptors are also decreased but only in a certain proportion (30-40%) of SDAT patients. For other systems, it appears that cortical serotonin (5-HT)-type 2 receptor binding sites are decreased in SDAT. This diminution in 5-HT2 receptors correlates well with the decreased levels of somatostatin-like immunoreactive materials found in the cortex of SDAT patients. Cortical somatostatin receptor binding sites are decreased in about one third of SDAT patients. Finally, neuropeptide Y and neuropeptide Y receptor binding sites are distributed in areas enriched in cholinergic cell bodies and nerve fiber terminals and it would be of interest to determine possible involvement of this peptide in SDAT. Thus, it appears that multi-drug clinical trials should be considered for the treatment of SDAT.
In laboratory studies, ovipositing northern corn rootworm beetles significantly preferred Ste. Rosalie clay soil with particles 1 mm – 1.4 cm in diameter. In the field, unaltered local farm soil with natural cracks was preferred for oviposition to mechanically-disturbed soil. Surface condition, surface cover, and soil moisture all combined to influence the choice of oviposition site in field soils.
The development of insects that live within plant tissues has always been difficult to observe. Reliable information on their biology has been obtained by making daily dissections of infested plants but that procedure sacrifices both insects and plants and does not allow continuous observations of individual insects from plant entrance to emergence. Milner et al. (1950) developed an X-ray technique which provided satisfactory delineation of internal infestation of insects in grain. With their method they were able to observe insect development of the granary weevil, Sitophilus granarius (L.), and the rice weevil, Sitophilus oryzae (L.), without any deleterious effects of radiation upon their development. Other techniques applied in seed testing (Metzner 1962), coffee beans, and nut evaluations (Esteves 1959; Vilar 1966) are not applicable to soft vegetable materials such as maize stalk and ear.