Valuing the benefit of varicella vaccination: comparison of willingness to pay and quality-adjusted life-years

Vaccination is different from most health interventions because it is preventative, it protects against infectious disease (leading to knock-on effects), the diseases it prevents are usually acute and self-limiting, and most vaccines are given to children from whom it is very difficult to elicit preferences. Because of its unique characteristics, vaccination may possess its own specific attributes. In this paper, we estimate the average Willingness to Pay (WTP) for varicella vaccination and the Quality-Adjusted Life-Years (QALY) lost due to chickenpox using Contingent Valuation (CV), Standard Gamble and Health Utility Index Mark II (HUI2). Furthermore, we identify what attributes of vaccination are important to vaccinees and what elicitation technique can capture these components. To do this, we administered computerised interviews to a sample of parents attending primary Health Centres. Using CV we demonstrate that individuals are willing to pay more for vaccination than treatment. Furthermore, we show that prevention of work loss is an important intervention attribute for parents. On the other hand, consistent with economic theory, the elicitation techniques used to estimate QALYs (Standard Gamble and HUI2) did not capture non-health benefits. Finally, results elicited using the CV were correlated with QALYs measured through the HUI2 questionnaire

Effect of a major ice storm on understory light conditions in an old-growth Acer-Fagus forest: Pattern of recovery over seven years

We evaluated the effects of a major ice storm on understory light conditions (%PPFD, photosynthetic photon flux density) in an old-growth Acer-Fagus forest in Quebec, based on pre- and post-disturbance light measurements taken until the seventh growing season after the event (which occurred in January 1998). Before the ice storm, most microsites received between 2 and 4%PPFD. Following the ice storm, the stand-level mean %PPFD increased four- to five-fold, ranging from 13.8 to 20.5%PPFD, from 0.3 to 4 m aboveground. Despite its magnitude, the post-ice storm increase in light transmission was short-lived. By 1999 (2-year+), the mean light levels had decreased by half, and recovery to pre-storm conditions occurred within 3-7 years, depending on height. The decrease in light transmission during the post-disturbance years followed an inverse J-shape trend, indicating more dynamic changes early after disturbance. By 2004 (7-year+), light levels at ≤2 m had become slightly but significantly lower than before the ice storm, with most microsites receiving <2%PPFD. The ice storm led to a synchronized increase of the light levels at almost all understory locations, which might allow a high proportion of the advanced regeneration to experience a release. However, due to the rapid recovery of the light conditions to levels similar or lower than before the ice storm, this disturbance should be more advantageous to shade-tolerant species

Towards a human eye behavior model by applying Data Mining Techniques on Gaze Information from IEC

In this paper, we firstly present what is Interactive Evolutionary Computation (IEC) and rapidly how we have combined this artificial intelligence technique with an eye-tracker for visual optimization. Next, in order to correctly parameterize our application, we present results from applying data mining techniques on gaze information coming from experiments conducted on about 80 human individuals

Forecasting Some Low-Predictability Time Series Using Diffusion Indices

The growth rates of real output and real investment are two macroeconomic time series which are particularly difficult to forecast. This paper considers the application of diffusion index forecasting models to this problem. We begin by characterizing the performance of standard forecasts, via recently-introduced measures of predictability and the forecast content, noting the maximum horizon at which the forecasts have value. We then compare diffusion index forecasts with a variety of alternatives, including the forecasts made by the OECD. We find gains in forecast accuracy at short horizons from the diffusion index models, but do not find evidence that the maximum horizon for forecasts can be extended in this way. Les taux de croissance de production et d'investissements réels sont deux séries macroéconomiques qui sont particulièrement difficiles à prévoir. Nous considérons dans cet article l'application des méthodes d'indice de diffusion à ce problème. Nous commençons avec une caractérisation de la performance des méthodes de prévision standards, via les mesures nouvelles de prévisibilité et la valeur ajoutée des prévisions, en notant l'horizon maximal auquel les prévisions ont de la valeur. Nous comparons les prévisions provenant des indices de diffusion avec les alternatives, incluant les prévisions de l'OCDE. Nous trouvons des gains en précision des prévisions,0501s ne trouvons pas que l'horizon maximal de prévision peut être augmenté.Diffusion index, forecasting, investment, GDP, Indice de diffusion, prévisions, investissement, PNB

Metabolomic Analysis Reveals Contributions of Citric and Citramalic Acids to Rare Earth Bioleaching by a Paecilomyces Fungus.

Conventional methods for extracting rare earth elements from monazite ore require high energy inputs and produce environmentally damaging waste streams. Bioleaching offers a potentially more environmentally friendly alternative extraction process. In order to better understand bioleaching mechanisms, we conducted an exo-metabolomic analysis of a previously isolated rare earth bioleaching fungus from the genus Paecilomyces (GenBank accession numbers KM874779 and KM 874781) to identify contributions of compounds exuded by this fungus to bioleaching activity. Exuded compounds were compared under two growth conditions: growth with monazite ore as the only phosphate source, and growth with a soluble phosphate source (K2HPO4) added. Overall metabolite profiling, in combination with glucose consumption and biomass accumulation data, reflected a lag in growth when this organism was grown with only monazite. We analyzed the relationships between metabolite concentrations, rare earth solubilization, and growth conditions, and identified several metabolites potentially associated with bioleaching. Further investigation using laboratory prepared solutions of 17 of these metabolites indicated statistically significant leaching contributions from both citric and citramalic acids. These contributions (16.4 and 15.0 mg/L total rare earths solubilized) accounted for a portion, but not all, of the leaching achieved with direct bioleaching (42 ± 15 mg/L final rare earth concentration). Additionally, citramalic acid released significantly less of the radioactive element thorium than did citric acid (0.25 ± 0.01 mg/L compared to 1.18 ± 0.01 mg/L), suggesting that citramalic acid may have preferable leaching properties for a monazite bioleaching process

La santé au travail et la convention collective

Cet article traite de l'utilisation de la convention collective en tant qu'outil d'intervention en matière de santé au travailThis study deals with the effectiveness of the collective agreement as a means of intervention in questions of occupational health.The first part of the study briefly situates the question of occupational health in historical and present perspectives. The possibility of inserting preventive measures in collective agreements is then treated, followed by the elaboration of research objectives.The potential impact of the collective agreement on occupational health is limited by several factors. Nevertheless, the successes registered through them seem significant to concrete action in the workplace, and have been repeatedly and will probably continue to be used. The task at hand, therefore, is to analyse the degree of success achieved.The study's sample included 491 collective agreements negotiated in the following sectors: manufacturing, mining and forest products. The contents of the collective agreements were analyzed by type of provision. Most frequent were references to participatory bodies (joint or otherwise) governing protective equipment and compensation. Second in importance were references to health services, information, the right of refusal, and inspection. Provisions on training and rehabilitation are less frequent, while. those on research are almost non-existent. Each classification is clearly defined, and statistical tables are provided on several points.The interpretation of results is subdivised into two parts:— The information available reveals a definite general interest of the bargaining partners regarding occupational health. Thus, approximately 80% of the collective agreements contained at least one pertinent provision.— This overall interest, however, must be clearly distinguished from its effectiveness in practice.As regards the second part, several points are dealt with:— In order to provide meaningful protection in the areas of prevention and compensation, the relevant provisions must be as encompassing as possible. In fact, less than half of the collective agreements even approach this criteria.— The practical impact of the relevant provisions, based on their precision, varies a great deal from one agreement to the next.— Taken quantitatively, the relevant provisions are more oriented toward compensation than prevention, such as research, information and training.In view of such results, it should be recognized that Law 17 (Loi sur la santé et la sécurité au travail), if properly applied, will permit a greater number of workers to benefit from the rights and remedial structures contained presently in a limited number of collective agreements.— On the other hand, the results of this study should not be considered purely in quantitative terms. In several cases, provisions of less general impact were revealed to be very effective from the point of view of concrete applications of the collective agreement.The development of preoccupations with occupational health in collective agreements is considered in the folio wing two ways: the increase in the use of provisions concerning occupational health over the years, as well as the impact of recent provincial legislation on occupational health and safety.In conclusion, the limits of the collective agreement, as practised in our industrial relations System, are evaluated

Resource and non-resource root competition among trees of different successional status

1. This study assessed the effects of resource (i.e. nutrients) and non-resource (i.e. interference for space) competition from fine roots of competing grasses on the growth, morphology and architecture of fine roots of four tree species of varying successional status: Populus deltoides × P. balsamifera (a\ud hybrid), Betula papyrifera, Acer saccharum and Fraxinus americana. We tested the general hypothesis that tree fine-roots are affected by both below-ground resource and non-resource competition from non-self plants, and the more specific hypothesis that this effect is stronger in early- successional tree species.\ud 2. The experiment was conducted in split-containers where half of the roots of tree seedlings experienced either below-ground resource competition or non-resource competition, or both, by grasses while the other half experienced no competition.\ud 3. The late-successional tree species A. saccharum and\ud F. americana were mostly affected by resource competition, whereas the early-successional P. deltoides × balsamifera\ud and B. papyrifera were strongly affected by both resource and non-resource competition. Non-resource competition reduced fine-root growth, root branching over root length (a measure of root architecture) and specific root length (a measure of root morphology) of both early-successional species.\ud 4. Synthesis. This study suggests that early-successional tree species have been selected for root avoidance or segregation and late-successional tree species for root tolerance of competition as mechanisms to improve below-ground resource uptake in their particular environments. It also\ud contradicts recent studies showing perennial and annual grasses tend to overproduce roots in the presence of non-self conspecific plants. Woody plants, required to grow and develop for long periods in the presence of other plants, may react differently to non-self root competition than perennial or\ud annual grasses that have much shorter lives

Etude des dimensions du tempérament du cheval : évaluation expérimentale de différents traits de tempérament au moyen de tests comportementaux

Le tempérament peut être un facteur déterminant dans l'utilisation du cheval. Par tempérament on désigne un ensemble de caractéristiques individuelles présentant un certain degré de constance dans le temps et entre différentes situations. Pour alimenter une conception multifactorielle du tempérament, nous avons étudié un ensemble de traits comportementaux aussi large que possible : docilité, caractère peureux, motivation sociale, nervosité, persévérance et capacités d'apprentissage. Cette étude a confirmé la stabilité dans des contextes équivalents d'un certain nombre de caractéristiques comportementales. En terme d'application pratique, cela signifie qu'il est envisageable de déterminer la prédisposition d'un cheval à se comporter d'une certaine manière dans un contexte donné. La portée prédictive de l'évaluation du tempérament d'un cheval doit encore être approfondie, essentiellement lors des modifications physiologiques normales du développement (sevrage, puberté, vieillissement)