31,250 research outputs found
Comparison of different objective functions for parameterization of simple respiration models
The eddy covariance measurements of carbon dioxide fluxes collected around the world offer a rich source for detailed data analysis. Simple, aggregated models are attractive tools for gap filling, budget calculation, and upscaling in space and time. Key in the application of these models is their parameterization and a robust estimate of the uncertainty and reliability of their predictions. In this study we compared the use of ordinary least squares (OLS) and weighted absolute deviations (WAD, which is the objective function yielding maximum likelihood parameter estimates with a double exponential error distribution) as objective functions within the annual parameterization of two respiration models: the Q10 model and the Lloyd and Taylor model. We introduce a new parameterization method based on two nonparametric tests in which model deviation (Wilcoxon test) and residual trend analyses (Spearman test) are combined. A data set of 9 years of flux measurements was used for this study. The analysis showed that the choice of the objective function is crucial, resulting in differences in the estimated annual respiration budget of up to 40%. The objective function should be tested thoroughly to determine whether it is appropriate for the application for which the model will be used. If simple models are used to estimate a respiration budget, a trend test is essential to achieve unbiased estimates over the year. The analyses also showed that the parameters of the Lloyd and Taylor model are highly correlated and difficult to determine precisely, thereby limiting the physiological interpretability of the parameter
A Comparison of Methodologies for Valuing Decreased Health Effects from Wildfire Smoke
Wildfire seasons are becoming longer and more intense throughout the world, making it increasingly important to monetize the full damages caused by wildfires when analyzing various fire management policies. We estimate the economic costs of the health effects associated with exposure to wildfire smoke using a simple cost of illness approach and for the first time to our knowledge we estimate willingness-to-pay (WTP) for a decrease in symptom days from wildfire smoke using the contingent valuation method and the averting behavior method. Comparing estimates across all three common approaches for estimating the economic cost of exposure to an air pollutant is an important contribution to the literature. This study uses data from the largest wildfire in Los Angeles County’s modern history, the Station Fire of 2009. Our results show that a simple cost of illness estimate is about 43 or 74 - $98 to avoid one day of wildfire-smoke induced symptom days, depending on model specification.averting behavior method, contingent valuation method, cost of illness, wildfire smoke, health, morbidity, Environmental Economics and Policy, Health Economics and Policy, Q,
Discrimination techniques employing both reflective and thermal multispectral signals
Recent improvements in remote sensor technology carry implications for data processing. Multispectral line scanners now exist that can collect data simultaneously and in registration in multiple channels at both reflective and thermal (emissive) wavelengths. Progress in dealing with two resultant recognition processing problems is discussed: (1) More channels mean higher processing costs; to combat these costs, a new and faster procedure for selecting subsets of channels has been developed. (2) Differences between thermal and reflective characteristics influence recognition processing; to illustrate the magnitude of these differences, some explanatory calculations are presented. Also introduced, is a different way to process multispectral scanner data, namely, radiation balance mapping and related procedures. Techniques and potentials are discussed and examples presented
Do student nurses feel a lack of comfort in providing support for Lesbian, Gay, Bisexual or Questioning adolescents: what factors influence their comfort level?
Aim: The aim of this study was to find out if student nurses feel comfortable in caring by providing support for Lesbian, Gay, Bisexual or Questioning adolescents and what factors influence their level of comfort.
Background: Research indicates that nurses and nursing students experience varying levels of comfort when caring for adults who are Lesbian, Gay, Bisexual or Questioning: adult patients feel that nurse’s attitudes change towards them once they disclose their sexuality. There has been minimal research to date on nursing attitudes to working with adolescents who are Lesbian, Gay, Bisexual or Questioning.
Design Both quantitative and qualitative methods were used in this descriptive study. Questionnaires were completed by 152 nursing students and 9 took part in semi-structured focus groups.
Method: A two way ANOVA was used to analyse the questionnaires. Thematic analysis was used to identify the themes arising from the focus groups. Data was collected between August 2013 and July 2014.
Results/Findings: The results and findings of the study were that student nurse’s felt discomfort in providing support; due to a lack of knowledge of Lesbian, Gay or Bisexual sexuality, personal and religious beliefs and the perceptions of others. However, all students indicated they had a positive attitude towards Lesbian, Gay, Bisexual and Questioning adolescents.
Conclusion: More needs to be done to raise self-awareness and improve the level of knowledge in relation to Lesbian, Gay and Bisexual issues amongst student nurses. Educational institutions and practice areas need to recognize this fact and reflect this in their educational programmes
Sensitivity of orbiting JEM-EUSO to large-scale cosmic-ray anisotropies
The two main advantages of space-based observation of extreme-energy
(~eV) cosmic-rays (EECRs) over ground-based observatories are
the increased field of view, and the all-sky coverage with nearly uniform
systematics of an orbiting observatory. The former guarantees increased
statistics, whereas the latter enables a partitioning of the sky into spherical
harmonics. We have begun an investigation, using the spherical harmonic
technique, of the reach of \J\ into potential anisotropies in the
extreme-energy cosmic-ray sky-map. The technique is explained here, and
simulations are presented. The discovery of anisotropies would help to identify
the long-sought origin of EECRs.Comment: 7 pages, 6 figures. To appear in the proceedings of the Cosmic Ray
Anisotropy Workshop, Madison Wisconsin, September 201
On the analytic solution of the pairing problem: one pair in many levels
We search for approximate, but analytic solutions of the pairing problem for
one pair of nucleons in many levels of a potential well. For the collective
energy a general formula, independent of the details of the single particle
spectrum, is given in both the strong and weak coupling regimes. Next the
displacements of the solutions trapped in between the single particle levels
with respect to the unperturbed energies are explored: their dependence upon a
suitably defined quantum number is found to undergo a transition between two
different regimes.Comment: 30 pages, AMS Latex, 8 figures. Submitted to Phys. Rev.
Nano-scale analysis of titanium dioxide fingerprint-development powders
Titanium dioxide based powders are regularly used in the development of latent fingerprints on dark surfaces. For analysis of prints on adhesive tapes, the titanium dioxide is suspended in a surfactant and used in the form of a small particle reagent (SPR). Analysis of commercially available products shows varying levels of effectiveness of print development, with some powders adhering to the background as well as the print. Scanning electron microscopy (SEM) images of prints developed with different powders show a range of levels of aggregation of particles.
Analytical transmission electron microscopy (TEM) of the fingerprint powder shows TiO2 particles with a surrounding coating, tens of nanometres thick, consisting of Al and Si rich material. X ray photoelectron spectroscopy (XPS) is used to determine the composition and chemical state of the surface of the powders; with a penetration depth of approximately 10nm, this technique demonstrates differing Ti: Al: Si ratios and oxidation states between the surfaces of different powders. Levels of titanium detected with this technique demonstrate variation in the integrity of the surface coating. The thickness, integrity and composition of the Al/Si-based coating is related to the level of aggregation of TiO2 particles and efficacy of print development
The many levels pairing Hamiltonian for two pairs
We address the problem of two pairs of fermions living on an arbitrary number
of single particle levels of a potential well (mean field) and interacting
through a pairing force. The associated solutions of the Richardson's equations
are classified in terms of a number , which reduces to the seniority
in the limit of large values of the pairing strength and yields the number
of pairs not developing a collective behaviour, their energy remaining finite
in the limit. We express analytically, through the moments of the
single particle levels distribution, the collective mode energy and the two
critical values and of the coupling which can
exist on a single particle level with no pair degeneracy. Notably and merge when the number of single particle levels
goes to infinity, where they coincide with the (when it exists) of
a one pair system, not envisioned by the Richardson theory. In correspondence
of the system undergoes a transition from a mean field to a
pairing dominated regime. We finally explore the behaviour of the excitation
energies, wave functions and pair transfer amplitudes finding out that the
former, for , come close to the BCS predictions, whereas the
latter display a divergence at , signaling the onset of a long
range off-diagonal order in the system.Comment: 35 pages, 6 figures, 2 tables, to be published in EPJ
Body mass index and age affect Three-Factor Eating Questionnaire scores in male subjects
This cross-sectional analysis evaluated the effect of age and body mass index (BMI) on Three-Factor Eating Questionnaire scores in males. Subjects (n = 60) were recruited according to BMI status. Each completed the 51-item Three-Factor Eating Questionnaire. The group was split at the median age to produce a "younger" and "older" group for statistical analysis. A 2-way between-groups analysis of variance revealed a significant main effect of BMI on disinhibition (P = .003) and hunger (P = .041) with higher levels found in overweight males compared to healthy-weight counterparts. A significant main effect of age on hunger (P = .046) demonstrated older males were less susceptible to hunger than younger males. These insights provide a better understanding of eating behavior across the male life cycle and may assist health professionals to better guide men in weight management in the light of rising overweight/obesity. (c) 2009 Elsevier Inc. All rights reserved
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