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Objective Despite its well-known effectiveness, the cost-effectiveness of epilepsy surgery has never been demonstrated in France. We compared cost-effectiveness between resective surgery and medical therapy in a controlled cohort of adult patients with partial intractable epilepsy. Methods A prospective cohort of adult patients with surgically remediable and medically intractable partial epilepsy was followed over 5 years in the 15 French centers. Effectiveness was defined as 1 year without a seizure, based on the International League Against Epilepsy ( ILAE) classification. Clinical outcomes and direct costs were compared between surgical and medical groups. Long-term direct costs and effectiveness were extrapolated over the patients' lifetimes with a Monte-Carlo simulation using a Markov model, and an incremental cost-effectiveness ratio ( ICER) was computed. Indirect costs were also evaluated. Results Among the 289 enrolled surgery candidates, 207 were operable-119 in the surgical group and 88 in the medical group-65 were not operable and not analyzed here, 7 were finally not eligible, and 10 were not followed. The proportion of patients completely seizure-free during the last 12 months ( ILAE class 1) was 69.0% in the operated group and 12.3% in the medical group during the second year (p < 0.001), and it was respectively 76.8% and 21% during the fifth year (p < 0.001). Direct costs became significantly lower in the surgical group the third year after surgery, as a result of less antiepileptic drug use. The value of the discounted ICER was 10,406 (95% confidence interval [ CI] 10,182-10,634) at 2 years and 2,630 ( CI 95% 2,549-2,713) at 5 years. Surgery became cost-effective between 9 and 10 years after surgery, and even earlier if indirect costs were taken into account as well. Significance Our study suggests that in addition to being safe and effective, resective surgery of epilepsy is cost-effective in the medium term. It should therefore be considered earlier in the development of epilepsy. [ABSTRACT FROM AUTHOR]

Mathematical modelling was combined with experimental Cu isotope measurements to demonstrate the effect of the sample matrix in changing the absolute and relative abundances of spectral interferences from Ti and Cr species. This unforeseen non-spectral effect, evidenced by variable inaccuracies of the different Zn-normalised Cu isotope ratios, was investigated by comparing real sedimentary samples and artificial solutions intended to match the Cu: Ti: Cr ratios of the real samples after (one or two step) chromatographic processing. Artificial solutions showed positive bias in δ65 Cu X/ Y with the magnitude depending on (a) the 6 XZn/6 YZn ratio used for normalisation, (b) the Ti/ Cu ratio and (c) the transmission coefficient of the TiO species. In contrast, real samples showed different δ65 CuX/ Y patterns and displayed a more complex population of Ti and Cr oxides and hydroxides, giving rise to positive and negative inaccuracies that were two to six times higher compared with the artificial samples. The results evidence contrasting behaviour of Ti and Cr when forming polyatomic species in the plasma and stress that artificial solutions may fail to predict how residual elements interact with the analyte/dopant pair during MC- ICP- MS analyses. More importantly, the study shows that all Zn isotope ratios do not have the same merit in correcting for mass bias in the presence of matrix elements and should all be monitored to verify the absence of spectral interferences for Cu isotope measurements. In this respect, accurate Cu data could be generally obtained by a two-step chromatographic purification providing a minimum reduction of ~ 21000 and ~ 3000 times the initial amounts of Ti and Cr, respectively. [ABSTRACT FROM AUTHOR]

In the context of climate change, the effects of prolonged or more severe droughts on pest and pathogen damage are a major concern for forest ecosystems. To date, there is great uncertainty about the direction, magnitude and sources of variation in responses to drought by insects and fungi. We report the outcomes of a meta-analysis of 100 pairwise comparisons of insect pest or pathogen damage to water-stressed and control trees from 40 publications. The type of feeding substrate for insects and fungi and the water stress severity emerged as the main factors influencing the level of damage in water-stressed trees. Overall, primary damaging agents living in wood caused significantly lower damage to the water-stressed trees compared with the control, whereas primary pests and pathogens living on foliage caused more damage to water-stressed trees, in all cases irrespective of stress severity. In contrast, damage by secondary agents increased with stress severity, which was best estimated by the ratio between the predawn leaf water potential in stressed trees and the xylem pressure inducing 50% loss in hydraulic conductance due to cavitation, a species-specific index of drought tolerance. Insect and fungus feeding behaviour, affected tree part, and water stress severity are therefore proposed as three important predictors of forest damage in drought conditions. [ABSTRACT FROM AUTHOR]

The present study evaluates several critical issues related to precision and accuracy of Cu and Zn isotopic measurements with application to estuarine particulate materials. Calibration of reference materials (such as the IRMM 3702 Zn) against the JMC Zn and NIST Cu reference materials were performed in wet and/or dry plasma modes (Aridus I and DSN-100) on a Nu Plasma MC-ICP-MS. Different mass bias correction methods were compared. More than 100 analyses of certified reference materials suggested that the sample-calibrator bracketing correction and the empirical external normalisation methods provide the most reliable corrections, with long term external precisions of 0.06 and 0.07‰ (2SD), respectively. Investigation of the effect of variable analyte to spike concentration ratios on Zn and Cu isotopic determinations indicated that the accuracy of Cu measurements in dry plasma is very sensitive to the relative Cu and Zn concentrations, with deviations of δ65Cu from −0.4‰ (Cu/Zn = 4) to +0.4‰ (Cu/Zn = 0.2). A quantitative assessment (with instrumental mass bias corrections) of spectral and non-spectral interferences (Ti, Cr, Co, Fe, Ca, Mg, Na) was performed. Titanium and Cr were the most severe interfering constituents, contributing to inaccuracies of −5.1‰ and +0.60‰ on δ68/64Zn, respectively (for 500 μg l−1 Cu and Zn standard solutions spiked with 1000 μg l−1 of Ti or Cr). Preliminary isotopic results were obtained on contrasting sediment matrices from the Scheldt estuary. Significant isotopic fractionation of zinc (from 0.21‰ to 1.13‰ for δ66Zn) and copper (from −0.38‰ to 0.23‰ for δ65Cu), suggest a control by physical mixing of continental and marine water masses, characterized by distinct Cu and Zn isotopic signatures. These results provide a stepping-stone to further evaluate the use of Cu and Zn isotopes as biogeochemical tracers in estuarine environments. [ABSTRACT FROM AUTHOR]