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

Assortative mixing as a source of bias in epidemiological studies of sexually transmitted infections: the case of smoking and human papillomavirus

For studies examining risk factors of sexually transmitted infections (STIs), confounding can stem from characteristics of partners of study subjects, and persist after adjustment for the subjects’ individual-level characteristics. Two conditions that can result in confounding by the subjects’ partners are: (C1) partner choice is assortative by the risk factor examined and, (C2) sexual activity is associated with the risk factor. The objective of this paper is to illustrate the potential impact of the assortativity bias in studies examining STI risk factors, using smoking and human papillomavirus (HPV) as an example. We developed an HPV transmission-dynamic mathematical model in which we nested a cross-sectional study assessing the smoking–HPV association. In our base case, we assumed (1) no effect of smoking on HPV, and (2) conditions C1–C2 hold for smoking (based on empirical data). The assortativity bias caused an overestimation of the odds ratio (OR) in the simulated study after perfect adjustment for the subjects’ individual-level characteristics (adjusted OR 1·51 instead of 1·00). The bias was amplified by a lower basic reproductive number (R(0)), greater mixing assortativity and stronger association of smoking with sexual activity. Adjustment for characteristics of partners is needed to mitigate assortativity bias

The cellular interactions of PEGylated gold nanoparticles : effect of PEGylation on cellular uptake and cytotoxicity

Poly(ethylene glycol) (PEG) is frequently used to coat various medical nanoparticles (NPs). As PEG is known to minimize NP interactions with biological specimens, the question remains whether PEGylated NPs are intrinsically less toxic or whether this is caused by reduced NP uptake. In the present work, the effect of gold NP PEGylation on uptake by three cell types is compared and evaluated the effect on cell viability, oxidative stress, cell morphology, and functionality using a multiparametric methodology. The data reveal that PEGylation affects cellular NP uptake in a cell-type-dependent manner and influences toxicity by different mechanisms. At similar intracellular NP numbers, PEGylated NPs are found to yield higher levels of cell death, mostly by induction of oxidative stress. These findings reveal that PEGylation significantly reduces NP uptake, but that at similar functional (= cell-associated) NP levels, non-PEGylated NPs are better tolerated by the cells

Traitement de polissage par marais épurateur du drainage minier acide

Affiche présentée dans le cadre du Colloque de l'ARC, «La culture de la recherche au collégial», dans le cadre du 82e Congrès de l'Acfas, Université Concordia, Montréal, le 14 mai 2014.Les résidus miniers représentent une source de danger potentiel pour l'environnement, en particulier lorsque ces déchets contiennent des minéraux sulfureux qui peuvent s'oxyder et générer du drainage minier acide (DMA). Ce dernier est caractérisé par un pH faible et des concentrations en sulfates et métaux dissous élevées. Les traitements biologiques constituent une solution moins coûteuse par rapport aux traitements chimiques, en plus de présenter plusieurs avantages dont des taux élevés d’enlèvement des métaux, une réduction du pH, de faibles coûts d’exploitation et une consommation minimale d’énergie. La capacité des marais filtrants à traiter un DMA chargé en fer à l’étape de polissage a été étudiée. Les systèmes consistaient en des marais artificiels à écoulement vertical et horizontal de 0,052 m3, remplis de deux différents substrats et plantés avec des quenouilles (Typha latifolia). Ils étaient alimentés pour traiter 1,5 mL/min d’un DMA ayant une concentration moyenne de 38,0 mg/L de fer, 2,6 mg/L de manganèse, 0,4 mg/L de nickel et 0,9 mg/L de zinc à un pH moyen de 4,2. Après traitement, le pH moyen à l’effluent était de 8,0 pour les marais verticaux et de 7,6 pour les horizontaux. Le taux d’enlèvement du fer et du zinc était respectivement de 95 et 96 % pour les marais à écoulement verticaux et de 87 et 94 % pour les horizontaux. Le traitement du nickel et du manganèse était négligeable

Vaccinating Girls and Boys with Different Human Papillomavirus Vaccines: Can It Optimise Population-Level Effectiveness?

<label>BACKGROUND</label>Decision-makers may consider vaccinating girls and boys with different HPV vaccines to benefit from their respective strengths; the quadrivalent (HPV4) prevents anogenital warts (AGW) whilst the bivalent (HPV2) may confer greater cross-protection. We compared, to a girls-only vaccination program with HPV4, the impact of vaccinating: 1) both genders with HPV4, and 2) boys with HPV4 and girls with HPV2.<label>METHODS</label>We used an individual-based transmission-dynamic model of heterosexual HPV infection and diseases. Our base-case scenario assumed lifelong efficacy of 100% against vaccine types, and 46,29,8,18,6% and 77,43,79,8,0% efficacy against HPV-31,-33,-45,-52,-58 for HPV4 and HPV2, respectively.<label>RESULTS</label>Assuming 70% vaccination coverage and lifelong cross-protection, vaccinating boys has little additional benefit on AGW prevention, irrespective of the vaccine used for girls. Furthermore, using HPV4 for boys and HPV2 for girls produces greater incremental reductions in SCC incidence than using HPV4 for both genders (12 vs 7 percentage points). At 50% vaccination coverage, vaccinating boys produces incremental reductions in AGW of 17 percentage points if both genders are vaccinated with HPV4, but increases female incidence by 16 percentage points if girls are switched to HPV2 (heterosexual male incidence is incrementally reduced by 24 percentage points in both scenarios). Higher incremental reductions in SCC incidence are predicted when vaccinating boys with HPV4 and girls with HPV2 versus vaccinating both genders with HPV4 (16 vs 12 percentage points). Results are sensitive to vaccination coverage and the relative duration of protection of the vaccines.<label>CONCLUSION</label>Vaccinating girls with HPV2 and boys with HPV4 can optimize SCC prevention if HPV2 has higher/longer cross-protection, but can increase AGW incidence if vaccination coverage is low among boys

Impacto social de las radiaciones no ionizantes y las políticas públicas

El objetivo del presente trabajo es fundamentar los beneficios de la contribución del asesoramiento profesional en la generación y transferencia del conocimiento, para la toma de decisiones en las políticas públicas que permita apropiarse de los avances y aplicaciones resultantes del trabajo científico desarrollado.Las Radiaciones No Ionizantes (RNI) son aquellas que no poseen la energía suficiente para ionizar la materia, pero que producen otro tipo de efectos, especialmente de tipo térmico. Sus efectos a largo plazo sobre la salud de los seres humanos aún es materia de discusión y es por esto que se genera en la ciudadanía una honda preocupación por el desconocimiento y falta de normativas a nivel municipal. El Grupo ITMA reúne un grupo interdisciplinario de profesionales con el objetivo de investigar el impacto de las RNI sobre el medio ambiente y los sistemas biológicos. Una de sus actividades es el asesoramiento a municipios y organismos públicos respecto de las RNI, en particular, el despliegue de antenas de telefonía móvil para generar ordenanzas municipales que contribuyan a la tranquilidad y mejora de la calidad de vida de la comunidad y contemplen los controles necesarios para preservar estas condiciones en el tiempo

Size Doesn\u27t Matter: Microbial Selection Experiments Address Ecological Phenomena

Experimental evolution is relevant to ecology because it can connect physiology, and in particular metabolism, to questions in ecology. The investigation of the linkage between the environment and the evolution of metabolism is tractable because these experiments manipulate a very simple environment to produce predictable evolutionary outcomes. In doing so, microbial selection experiments can examine the causal elements of natural selection: how specific traits in varying environments will yield different fitnesses. Here, we review the methodology of microbial evolution experiments and address three issues that are relevant to ecologists: genotype-by-environment interactions, ecological diversification due to specialization, and negative frequency-dependent selection. First, we expect that genotype-by-environment interactions will be ubiquitous in biological systems. Second, while antagonistic pleiotropy is implicated in some cases of ecological specialization, other mechanisms also seem to be at work. Third, while negative frequency-dependent selection can maintain ecological diversity in laboratory systems, a mechanistic (biochemical) analysis of these systems suggests that negative frequency dependence may only apply within a narrow range of environments if resources are substitutable. Finally, we conclude that microbial experimental evolution needs to avail itself of molecular techniques that could enable a mechanistic understanding of ecological diversification in these simple systems

Annexin-A5 assembled into two-dimensional arrays promotes cell membrane repair

Eukaryotic cells possess a universal repair machinery that ensures rapid resealing of plasma membrane disruptions. Before resealing, the torn membrane is submitted to considerable tension, which functions to expand the disruption. Here we show that annexin-A5 (AnxA5), a protein that self-assembles into two-dimensional (2D) arrays on membranes upon Ca2+ activation, promotes membrane repair. Compared with wild-type mouse perivascular cells, AnxA5-null cells exhibit a severe membrane repair defect. Membrane repair in AnxA5-null cells is rescued by addition of AnxA5, which binds exclusively to disrupted membrane areas. In contrast, an AnxA5 mutant that lacks the ability of forming 2D arrays is unable to promote membrane repair. We propose that AnxA5 participates in a previously unrecognized step of the membrane repair process: triggered by the local influx of Ca2+, AnxA5 proteins bind to torn membrane edges and form a 2D array, which prevents wound expansion and promotes membrane resealing

Large-scale synchrony of gap dynamics and the distribution of understory tree species in maple-beech forests

Large-scale synchronous variations in community dynamics are well documented for a vast array of organisms, but are considerably less understood for forest trees. Because of temporal variations in canopy gap dynamics, forest communities—even old-growth ones—are never at equilibrium at the stand scale. This paucity of equilibrium may also be true at the regional scale. Our objectives were to determine (1) if nonequilibrium dynamics caused by temporal variations in the formation of canopy gaps are regionally synchronized, and (2) if spatiotemporal variations in canopy gap formation aVect the relative abundance of tree species in the understory. We examined these questions by analyzing variations in the suppression and release history of Acer saccharum Marsh. and Fagus grandifolia Ehrh. from 481 growth series of understory saplings taken from 34 mature stands. We observed that (1) the proportion of stems in release as a function of time exhibited a U-shaped pattern over the last 35 years, with the lowest levels occurring during 1975–1985, and that (2) the response to this in terms of species composition was that A. saccharum became more abundant at sites that had the highest proportion of stems in release during 1975–1985. We concluded that the understory dynamics, typically thought of as a stand-scale process, may be regionally synchronized

Measurement of Multijet Production in ep Collisions at High Q^2 and Determination of the Strong Coupling alpha_s

84 Pages, 22 figure, 40 tables, submitted to EPJC ; see paper for full list of authorsInternational audienceInclusive jet, dijet and trijet differential cross sections are measured in neutral current deep-inelastic scattering for exchanged boson virtualities 150 < Q^2 < 15000 GeV^2 using the H1 detector at HERA. The data were taken in the years 2003 to 2007 and correspond to an integrated luminosity of 351 pb^{-1}. Double differential Jet cross sections are obtained using a regularised unfolding procedure. They are presented as a function of Q^2 and the transverse momentum of the jet, P_T^jet, and as a function of Q^2 and the proton's longitudinal momentum fraction, Xi, carried by the parton participating in the hard interaction. In addition normalised double differential jet cross sections are measured as the ratio of the jet cross sections to the inclusive neutral current cross sections in the respective Q^2 bins of the jet measurements. Compared to earlier work, the measurements benefit from an improved reconstruction and calibration of the hadronic final state. The cross sections are compared to perturbative QCD calculations in next-to-leading order and are used to determine the running coupling and the value of the strong coupling constant as alpha_s(M_Z) = 0.1165 (8)_exp (38)_{pdf,theo}