1,230 research outputs found
Solution of the Non‐homogeneous Helmholtz Equation for Optical Gratings with Perfectly Conducting Boundaries
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113718/1/sapm1966451383.pd
Flight control electronics reliability/maintenance study
Collection and analysis of data are reported that concern the reliability and maintenance experience of flight control system electronics currently in use on passenger carrying jet aircraft. Two airlines B-747 airplane fleets were analyzed to assess the component reliability, system functional reliability, and achieved availability of the CAT II configuration flight control system. Also assessed were the costs generated by this system in the categories of spare equipment, schedule irregularity, and line and shop maintenance. The results indicate that although there is a marked difference in the geographic location and route pattern between the airlines studied, there is a close similarity in the reliability and the maintenance costs associated with the flight control electronics
Phonon Density of States and Anharmonicity of UO2
Phonon density of states (PDOS) measurements have been performed on
polycrystalline UO2 at 295 and 1200 K using time-of-flight inelastic neutron
scattering to investigate the impact of anharmonicity on the vibrational
spectra and to benchmark ab initio PDOS simulations performed on this strongly
correlated Mott-insulator. Time-of-flight PDOS measurements include anharmonic
linewidth broadening inherently and the factor of ~ 7 enhancement of the oxygen
spectrum relative to the uranium component by the neutron weighting increases
sensitivity to the oxygen-dominated optical phonon modes. The first-principles
simulations of quasi-harmonic PDOS spectra were neutron-weighted and
anharmonicity was introduced in an approximate way by convolution with
wavevector-weighted averages over our previously measured phonon linewidths for
UO2 that are provided in numerical form. Comparisons between the PDOS
measurements and the simulations show reasonable agreement overall, but they
also reveal important areas of disagreement for both high and low temperatures.
The discrepancies stem largely from an ~ 10 meV compression in the overall
bandwidth (energy range) of the oxygen-dominated optical phonons in the
simulations. A similar linewidth-convoluted comparison performed with the PDOS
spectrum of Dolling et al. obtained by shell-model fitting to their historical
phonon dispersion measurements shows excellent agreement with the
time-of-flight PDOS measurements reported here. In contrast, we show by
comparisons of spectra in linewidth-convoluted form that recent
first-principles simulations for UO2 fail to account for the PDOS spectrum
determined from the measurements of Dolling et al. These results demonstrate
PDOS measurements to be stringent tests for ab initio simulations of phonon
physics in UO2 and they indicate further the need for advances in theory to
address lattice dynamics of UO2.Comment: Text slightly modified, results unchange
Variations in the quality of care of patients with acute myocardial infarction among Swiss university hospitals
Objectives. The objective of our study was to assess hospital variations in the quality of care delivered to acute myocardial infarction (AMI) patients among three Swiss academic medical centres. Design. Cross-sectional study. Setting. Three Swiss university hospitals. Study participants. We selected 1129 eligible patients discharged from these hospitals from 1 January to 31 December 1999, with a primary or secondary diagnosis code [International Classification of Diseases, 10th revision (ICD-10)] of AMI. We abstracted medical records for information on demographic characteristics, risk factors, symptoms, and findings at admission. We also recorded the main ECG and laboratory findings, as well as hospital and discharge management and treatment. We excluded patients transferred to another hospital and who did not meet the clinical definition of AMI. Main outcome measures. Percentage of patients receiving appropriate intervention as defined by six quality of care indicators derived from clinical practical guidelines. Results. Among 577 eligible patients with AMI in this study, the mean (SD) age was 68.2 (13.9), and 65% were male. In the assessment of the quality indicators we excluded patients who were not eligible for the procedure. Among cohorts of ‘ideal candidates' for specific interventions, 64% in hospital A and 73% in hospital C had reperfusion within 12 hours either with thrombolytics or percutaneous transluminal coronary angioplasty (P = 0.367). Further, in hospitals A, B, and C, respectively 97, 94, and 84% were prescribed aspirin during the initial hospitalization (P = 0.0002), and respectively 68, 91, and 75% received angiotensin converting enzyme inhibitors at discharge in the case of left ventricular systolic dysfunction (P = 0.003). Conclusions. Our results showed important hospital-to-hospital variations in the quality of care provided to patients with AMI between these three university hospital
Nondestructive Evaluation of Standing Trees With a Stress Wave Method
The primary objective of this study was to investigate the usefulness of a stress wave technique for evaluating wood strength and stiffness of young-growth western hemlock and Sitka spruce in standing trees. A secondary objective was to determine if the effects of silvicultural practices on wood quality can be identified using this technique. Stress wave measurements were conducted on 168 young-growth western hemlock and Sitka spruce trees. After in situ measurements, a 0.61-m-long bole section in the test span was taken from 56 felled trees to obtain small, clear wood specimens. Stress wave and static bending tests were then performed on these specimens to determine strength and stiffness. Results of this study indicate that in situ stress wave measurements could provide relatively accurate and reliable information that would enable nondestructive evaluation of wood properties in standing trees. The mean values of stress wave speed and dynamic modulus of elasticity for trees agreed with those determined from small, clear wood specimens. Statistical regression analyses revealed good correlations between stress wave properties of trees and static bending properties of small, clear wood specimens obtained from the trees. Regression models showed statistical significance at the 0.01 confidence level. Results of this study also demonstrate that the effect of silvicultural practices on wood properties can be identified with the stress wave properties of trees. This indicates that this nondestructive stress wave technique can be used to track property changes in trees and help determine how forests could be managed to meet desired wood and fiber qualities
Effects of intravenous theophylline on exercise-induced myocardial ischemia: II. A concentration-dependent phenomenon
AbstractObjectives. The effects of varying concentrations of theophylline on exercise-induced myocardial ischemia were evaluated in patients with stable coronary artery disease.Background. Theophylline is a competitive antagonist of adenosine and may have potential as an anti-ischemic medication. It is not known whether these effects on myocardial ischemia are concentration dependent.Methods. In a double-blind, randomized, crossover manner, 11 patients received, at 1-week intervals, placebo and each of three theophylline doses by intravenous infusion for 45 min. Graded exercise testing was performed before randomization and immediately after each infusion. Concurrent anti-ischemic medications were withheld for 24 h before each exercise test. Serum theophylline concentrations achieved were 3.9 ± 1.0 mg/liter (low), 8.2 ± 1.8 mg/liter (medium) and 13.2 ± 2.3 mg/liter (high).Results. Compared with placebo, none of the three theophylline infusions produced a significant alteration in rest heart rate, blood pressure, mean frequency or severity of ventricular ectopic activity or noncardiac symptoms. The time to onset of ischemia was progressively increased, with medium and high concentrations achieving statistical significance. Similar patterns were observed for oxygen uptake and the heart rate-systolic blood pressure product at the onset of ischemia. Total exercise duration was significantly prolonged with the medium and high concentrations.Conclusions. It is concluded that administration of varying doses of theophylline before exercise produces a clinically significant and concentration-dependent improvement in the indicators of myocardial ischemia in patients with chronic stable coronary artery disease
Shadowing in the nuclear photoabsorption above the resonance region
A model based on the hadronic fluctuations of the real photon is developed to
describe the total photonucleon and photonuclear cross sections in the energy
region above the nucleon resonances. The hadronic spectral function of the
photon is derived including the finite width of vector-meson resonances and the
quark-antiquark continuum. The shadowing effect is evaluated considering the
effective interaction of the hadronic component with the bound nucleons within
a Glauber-Gribov multiple scattering theory. The low energy onset of the
shadowing effect is interpreted as a possible signature of a modification of
the hadronic spectral function in the nuclear medium. A decrease of the
-meson mass in nuclei is suggested for a better explanation of the
experimental data.Comment: 8 pages, 7 figure
The equation of state of solid nickel aluminide
The pressure-volume-temperature equation of state of the intermetallic
compound NiAl was calculated theoretically, and compared with experimental
measurements. Electron ground states were calculated for NiAl in the CsCl
structure, using density functional theory, and were used to predict the cold
compression curve and the density of phonon states. The Rose form of
compression curve was found to reproduce the ab initio calculations well in
compression but exhibited significant deviations in expansion. A
thermodynamically-complete equation of state was constructed for NiAl. Shock
waves were induced in crystals of NiAl by the impact of laser-launched Cu
flyers and by launching NiAl flyers into transparent windows of known
properties. The TRIDENT laser was used to accelerate the flyers to speeds
between 100 and 600m/s. Point and line-imaging laser Doppler velocimetry was
used to measure the acceleration of the flyer and the surface velocity history
of the target. The velocity histories were used to deduce the stress state, and
hence states on the principal Hugoniot and the flow stress. Flyers and targets
were recovered from most experiments. The effect of elasticity and plastic flow
in the sample and window was assessed. The ambient isotherm reproduced static
compression data very well, and the predicted Hugoniot was consistent with
shock compression data
Is readmission to hospital an indicator of poor process of care for patients with heart failure?
BACKGROUND: Controversy exists about the appropriateness of using readmission as an indicator of the quality of care. A study was undertaken to measure the validity and predictive ability of readmission in this context. METHODS: An evaluation study was performed in patients discharged alive with heart failure from three Swiss academic medical centres. Process quality indicators were derived from evidence based guidelines for the management and treatment of heart failure. Readmissions were calculated from hospital administrative data. The predictive ability of readmissions was evaluated using bivariate and multivariate analyses, and validity by calculating sensitivity, specificity, positive and negative predictive value, using process indicators as the "gold standard". RESULTS: Of 1055 eligible patients discharged alive, 139 (13.2%) were readmitted within 30 days. The adjusted odds ratio (OR) for absence of measurement of left ventricular function was 0.70 (95% CI 0.45 to 1.08) for readmissions. In patients with left ventricular systolic dysfunction, three dose categories of angiotensin converting enzyme inhibitor were examined using ordinal logistic regression. The adjusted OR for these categories was 1.07 (95% CI 0.56 to 2.06) for readmissions. When using process indicators as the gold standard to assess the validity of readmissions, sensitivity ranged from 0.08 to 0.17 and specificity from 0.86 to 0.93. CONCLUSIONS: Readmission did not predict and was not a valid indicator of the quality of care for patients with heart failure admitted to three Swiss university hospitals. [Authors]]]>
Cardiac Output, Low ; Patient Readmission ; Quality Indicators, Health Care
oai:serval.unil.ch:BIB_CA2C9037E755
2022-05-07T01:27:02Z
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Genèse et l'évolution de la grammaire psychologique en Russie
Simonato, Elena
info:eu-repo/semantics/conferenceObject
inproceedings
2008
Actes du colloque "Structure de la proposition", pp. 217-134
Sériot, Patrick (ed.)
fre
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Las "muertas de Ciudad Juárez": construcción e impacto cultural de un acontecimiento serial
Kunz, Marco
info:eu-repo/semantics/bookPart
incollection
2016
Acontecimientos históricos y su productividad cultural en el mundo hispánico, pp. 137-156
Kunz, Marco (ed.)
Bornet, Rachel (ed.)
Girbés, Salvador (ed.)
Schultheiss, Michel (ed.)
info:eu-repo/semantics/altIdentifier/isbn/9783643802347
spa
oai:serval.unil.ch:BIB_CA2DD7891699
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Late presentation to HIV care despite good access to health services: current epidemiological trends and how to do better.
info:doi:10.4414/smw.2016.14348
info:eu-repo/semantics/altIdentifier/doi/10.4414/smw.2016.14348
info:eu-repo/semantics/altIdentifier/pmid/27544642
Darling, K.E.
Hachfeld, A.
Cavassini, M.
Kirk, O.
Furrer, H.
Wandeler, G.
info:eu-repo/semantics/review
article
2016
Swiss medical weekly, vol. 146, pp. w14348
info:eu-repo/semantics/altIdentifier/eissn/1424-3997
urn:issn:0036-7672
<![CDATA[In 2014, there were 36.9 million people worldwide living with human immunodeficiency virus (PLWH), of whom 17.1 million did not know they were infected. Whilst the number of new human immunodeficiency virus (HIV) infections has declined globally since 2000, there are still regions where new infection rates are rising, and diagnosing HIV early in the course of infection remains a challenge. Late presentation to care in HIV refers to individuals newly presenting for HIV care with a CD4 count below 350 cells/µl or with an acquired immune deficiency syndrome (AIDS)-defining event. Late presentation is associated with increased patient morbidity and mortality, healthcare costs and risk of onward transmission by individuals unaware of their status. Further, late presentation limits the effectiveness of all subsequent steps in the cascade of HIV care. Recent figures from 34 countries in Europe show that late presentation occurs in 38.3% to 49.8% of patients newly presenting for care, depending on region. In Switzerland, data from patients enrolled in the Swiss HIV Cohort Study put the rate of late presentation at 49.8% and show that patients outside established HIV risk groups are most likely to be late presenters. Provider-initiated testing needs to be improved to reach these groups, which include heterosexual men and women and older patients. The aim of this review is to describe the scale and implications of late presentation using cohort data from Switzerland and elsewhere in Europe, and to highlight initiatives to improve early HIV diagnosis. The importance of recognising indicator conditions and the potential for missed opportunities for HIV testing is illustrated in three clinical case studies
Assessment of family-derived metabolic traits for the conservation of an ancient fish
Physiological and behavioral traits of aquatic organisms are often highly dependent on environmental conditions, but genetic (family) effects often contribute to phenotypic variation. In this study, a series of physiological indices were used to assess the variability that exists among progeny of lake sturgeon (Acipenser fulvescens Rafinesque, 1817) produced from eight different families. We designed a controlled experiment aimed to evaluate metabolic performance of age-0 lake sturgeon where growth, energy density, survival, metabolic rate, volitional swimming performance, and critical thermal maxima were quantified for fish reared under the same environmental conditions. We found a strong family effect for most metrics that were quantified and primarily influenced by the female. Furthermore, poor growth and survival within families were strongly correlated to low energy density levels and depressed routine metabolic rates at the yolk sac stage. Lastly, the quantification of energy density at the onset of exogenous feeding appeared to be an excellent predictor of future growth and survival. Our results suggest that the choice of female for production of progeny in conservation hatcheries will have significant impacts on the success of stock enhancement as a conservation strategy for lake sturgeon. -- Keywords : lake sturgeon ; Acipenser fulvescens ; respirometry ; early life history ; conservation aquaculture ; critical thermal maxima
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