An overview of the time trade-off method:concept, foundation, and the evaluation of distorting factors in putting a value on health

INTRODUCTION: Preference-based instruments measuring health status express the value of specific health states in a single number. One method used is time trade-off (TTO). Health-status values are key elements in calculating quality-adjusted life years (QALYs) and are pertinent for resource allocation. Since they are used in economic evaluations of healthcare, searching for a theoretical foundation of TTO in economics is justified. AREA COVERED: This paper provides an overview of TTO, including its relation to economic theory, and discusses biases and distortions, compiled from recent and older research. Inconsistencies between TTO and random utility theory were detected; The TTO is confounded by time preferences and by respondents' life expectancies. TTO is cognitively challenging, therefore guidance during the interviews is needed, producing interview effects. TTO does not measure one thing at a time, nor are the values independent of other states that are being valued in the same task. That is, TTO does not exhibit theoretical measurement properties such as unidimensionality and the invariance principle. EXPERT OPINION: We conclude that the TTO may be a pragmatic method of eliciting health state values, but the limitations in regard to measurement theory and practical elicitation problems makes it prone to inconsistencies and arbitrariness

PACCE: Perl Algorithm to Compute Continuum and Equivalent Widths

We present Perl Algorithm to Compute continuum and Equivalent Widths (pacce). We describe the methods used in the computations and the requirements for its usage. We compare the measurements made with pacce and "manual" ones made using iraf splot task. These tests show that for SSP models the equivalent widths strengths are very similar (differences <0.2A) for both measurements. In real stellar spectra, the correlation between both values is still very good, but with differences of up to 0.5A. pacce is also able to determine mean continuum and continuum at line center values, which are helpful in stellar population studies. In addition, it is also able to compute the uncertainties in the equivalent widths using photon statistics. The code is made available for the community through the web at http://www.if.ufrgs.br/~riffel/software.html.Comment: 8 pages, 5 figures, accepted by Astrophysics and Space Scienc

The Nuclear Gas Dynamics and Star Formation of NGC 7469

We report interferometric radio CO2-1 observations at a resolution of 0.7", and 0.085" resolution adaptive optics K-band spectroscopy of the inner few arcseconds of NGC7469. The CO2-1 map shows a ring of molecular clouds and a bright extended nucleus, with a bar or pair of spiral arms between them. The dynamical structure of both the radio CO2-1 and the K-band H2 1-0S(1) lines can be reproduced using an axisymmetric mass model comprising 3 components: a broad disk, a ring 4-5" across, and an inner nuclear ring about 0.5" across. No non-circular motions faster than the velocity residuals of 25 km/s are seen, although this may be because in some cases a secondary bar is not expected to cause gas inflow. From the dynamical mass and estimates of the stellar mass we find that the CO-to-H_2 conversion is 0.4-0.8 times that for the Milky Way. The H2 1-0S(1) morphology peaks at the nucleus, although there is no strong nuclear mass concentration. The 1-0S(1) is likely to originate in X-ray of gas by the AGN rather than via star formation. Using the 2.3um stellar CO2-0 absorption and the continuum slope we have directly resolved the nuclear star cluster to be 0.15-0.20" across, and find that it is asymmetric. This cluster has an age of less than about 60Myr and contributes 20-30% of the nuclear K-band light, and about 10% of the nuclear bolometric luminosity. Within a radius of ~4" gas contributes more than half the total mass; but in the nucleus, within a radius of 0.1", it is likely that most of the mass is due to starsComment: accepted for publication in ApJ (see their pages for a version with higher quality figures

Estimating the detectable rate of capture of stellar mass black holes by massive central black holes in normal galaxies

The capture and subsequent inspiral of stellar mass black holes on eccentric orbits by central massive black holes, is one of the more interesting likely sources of gravitational radiation detectable by LISA. We estimate the rate of observable events and the associated uncertainties. A moderately favourable mass function could provide many detectable bursts each year, and a detection of at least one burst per year is very likely given our current understanding of the populations in cores of normal spiral galaxies.Comment: 3 pages 2-column revtex Latex macro. No figures. Classical and Quantum Gravity, accepte

On the central abundances of Active Galactic Nuclei and Star-forming Galaxies

We examine the relation between oxygen abundances in the narrow-line regions (NLRs) of active galactic nuclei (AGNs) estimated from the optical emission lines through the strong-line method (the theoretical calibration of Storchi-Bergmann et al. 1998), via the direct Te-method, and the central intersect abundances in the host galax- ies determined from the radial abundance gradients. We found that the Te-method underestimates the oxygen abundances by up to ∼2 dex (with average value of ~0.8 dex) compared to the abundances derived through the strong-line method. This con- firms the existence of the so-called ?temperature problem? in AGNs. We also found that the abundances in the centres of galaxies obtained from their spectra trough the strong-line method are close to or slightly lower than the central intersect abun- dances estimated from the radial abundance gradient both in AGNs and Star-forming galaxies. The oxygen abundance of the NLR is usually lower than the maximum at- tainable abundance in galaxies (~2 times the solar value). This suggests that there is no extraordinary chemical enrichment of the NLRs of AGNs.Fil: Dors Jr., O. L.. Universidade Do Vale Do Paraíba; BrasilFil: Cardaci, Monica Viviana. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Astrofísica de La Plata; ArgentinaFil: Hägele, Guillermo Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Astrofísica de la Plata; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Rodrigues, I.. Universidade Do Vale Do Paraíba; BrasilFil: Grebel, E. K. . Universität Heidelberg. Astronomisches Rechen-Institut. Zentrum für Astronomie; AlemaniaFil: Pilyugin, L. S. . Universität Heidelberg; Alemania. National Academy of Sciences of Ukraine; Ucrania. Kazan Federal University; RusiaFil: Freitas Lemes, P. . Universidade Do Vale Do Paraíba; BrasilFil: Krabbe, A. C. . Universidade Do Vale Do Paraíba; Brasi

Growth performance, morphometric analysis of the intestinal mucosa and thyroid of broiler fed canola meal.

Abstract: The aim of this study was to evaluate the effect of replacing soybean meal with canola meal in broiler diets on performance, liver histopathology, morphometry of the intestinal mucosa and thyroid. One-day-old Cobb chicks (n=300) were distributed in a completely randomized design, with increasing levels of replacement of soybean meal with canola meal (0, 25, 50, 75 and 100%) and 6 repetitions of 10 birds each. Weight gain decreased linearly (P< 0.05) with increasing levels of inclusion of canola meal, in all stages. Villus height in the duodenum and jejunum linearly decreased (P< 0.05). Follicle diameter and thyroid follicular epithelium height increased linearly with increasing levels of canola meal (P< 0.05). Similarly, there was an increase in relative weight of liver and heart, and liver steatosis in the highest levels of replacement. In conclusion, the replacement of soybean meal with canola meal can reduce performance, adversely affecting the thyroid, liver and the morphometric characteristics in the duodenum and jejunum. Resumo: O objetivo deste estudo foi avaliar o efeito da substituição do farelo de soja pelo farelo de canola na dieta de frangos de corte sobre o desempenho, a histopatologia hepática, a morfometria da mucosa intestinal e da tiroide. Foram distribuídos 300 pintos com um dia de idade em um delineamento inteiramente causualizado, com níveis crescentes de substituição do farelo de soja pelo farelo de canola (0, 25, 50, 75 e 100%), 6 repetições com 10 aves cada. O ganho de peso diminuiu linearmente (P< 0,05) com níveis crescentes da substituição, em todas as fases. Assim como, a altura das vilosidades no duodeno e jejuno diminuiu linearmente (P< 0,05) em todas as idades avaliadas. O diâmetro do folículo e a altura do epitélio da tireoide aumentaram linearmente conforme aumentou os níveis de farelo de canola (P< 0,05). Da mesma forma, houve um aumento do peso relativo do fígado e do coração, e aparecimento de esteatose hepática nos níveis mais altos de substituição. Em conclusão, a substituição do farelo de soja pelo farelo de canola pode reduzir o desempenho, afetando negativamente a tireoide, o fígado e as características morfométricas no duodeno e jejuno

On the central abundances of Active Galactic Nuclei and Star-forming Galaxies

We examine the relation between oxygen abundances in the narrow-line regions (NLRs) of active galactic nuclei (AGNs) estimated from the optical emission lines through the strong-line method (the theoretical calibration of Storchi-Bergmann et al. 1998), via the direct Te-method, and the central intersect abundances in the host galaxies determined from the radial abundance gradients. We found that the Te-method underestimates the oxygen abundances by up to ∼2 dex (with average value of ~0.8 dex) compared to the abundances derived through the strong-line method. This con- firms the existence of the so-called ?temperature problem? in AGNs. We also found that the abundances in the centres of galaxies obtained from their spectra trough the strong-line method are close to or slightly lower than the central intersect abun- dances estimated from the radial abundance gradient both in AGNs and Star-forming galaxies. The oxygen abundance of the NLR is usually lower than the maximum at- tainable abundance in galaxies (~2 times the solar value). This suggests that there is no extraordinary chemical enrichment of the NLRs of AGNs.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat