Influence of leaf area index prescriptions on simulations of heat, moisture, and carbon fluxes

Leaf area index (LAI), the total one-sided surface area of leaf per ground surface area, is a key component of land surface models. The authors investigate the influence of differing, plausible LAI prescriptions on heat, moisture, and carbon fluxes simulated by the Community Atmosphere Biosphere Land Exchange version 1.4b (CABLEv1.4b) model over the Australian continent. A 15-member ensemble monthly LAI dataset is generated using the Moderate Resolution Imaging Spectroradiometer (MODIS) LAI product and gridded observations of temperature and precipitation. Offline simulations lasting 29 years (1980–2008) are carried out at 25-km resolution with the composite monthly means from the MODIS LAI product (control simulation) and compared with simulations using each of the 15-member ensemble monthly varying LAI datasets generated. The imposed changes in LAI did not strongly influence the sensible and latent fluxes, but the carbon fluxes were more strongly affected. Croplands showed the largest sensitivity in gross primary production with differences ranging from −90% to 60%. Plant function types (PFTs) with high absolute LAI and low interannual variability, such as evergreen broadleaf trees, showed the least response to the different LAI prescriptions, while those with lower absolute LAI and higher interannual variability, such as croplands, were more sensitive. The authors show that reliance on a single LAI prescription may not accurately reflect the uncertainty in the simulation of terrestrial carbon fluxes, especially for PFTs with high interannual variability. The study highlights that accurate representation of LAI in land surface models is key to the simulation of the terrestrial carbon cycle. Hence, this will become critical in quantifying the uncertainty in future changes in primary production

Corrosion behaviour in saline solution of pulsed-electrodeposited zinc-nickel-ceria nanocomposite coatings

cited By 0International audiencePure Zn-Ni and Zn–Ni–ceria (CeO2) nanocomposite coatings were deposited onto steel substrates using pulse electrodeposition process from an acidic bath combined with preliminary sonication. Influences of different parameters such as pulse parameters, addition of nanoparticles in the electroplating bath, use of sonication to ensure their dispersion, were studied in terms of morphology, composition, and corrosion behaviour in saline solution. Results revealed a strong influence of the electrodeposition parameters on the corrosion behaviour of the Zn-Ni coatings. Incorporation of ceria nanoparticles is enhanced for the very short duration of the pulse due to the refinement of the microstructure. It was proved that composite coatings present an enhanced corrosion behaviour, while sonification does not afford a further improvement. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

Association of diagnostic work-up with subsequent attendance in a breast cancer screening program for false-positive cases.

International audienceThe objective of this study is to determine whether the likelihood of returning for routine breast cancer screening differed for false-positive cases depending on the diagnostic work-up. Using the original data from a French population-based breast cancer screening program, we compared the attendance rates at the subsequent round of screening for 16,946 and 1,127 participants who received negative (i.e., American College of Radiology, ACR, categories 1-2) and false-positive mammograms, respectively. False-positive mammograms were categorized ACR 0 (i.e., warranting additional imaging evaluation), 3 (i.e., warranting clinical and imaging follow-up), and 4-5 (i.e., warranting biopsy). We estimated the odds ratios of attendance at subsequent screening round using logistic regression, adjusting for age and history of previous mammography. The attendance rates at the subsequent screening round were 80.6% for women who received negative mammograms versus 69.6, 74.3, and 70.1% for women who received false-positive mammograms warranting additional imaging evaluation, clinical and imaging follow-up, or biopsy, respectively. In comparison to women who received negative mammograms, the corresponding adjusted odds ratios of returning for routine screening were 0.6 [95% confidence interval (CI) 0.4-0.8], 0.8 (95% CI 0.6-0.9), and 0.6 (95% CI 0.4-0.8). No significant differences were found in odds ratios of attendance across ACR categories among women who received false-positive mammograms. Similar figures were observed for attending at least one of the two subsequent screening rounds. In conclusion, in comparison to women with normal or benign findings on index mammograms, false-positive cases warranting additional imaging evaluation, clinical and imaging follow-up, or biopsy had uniformly decreased odds of attending subsequent routine screening rounds

Role of Ceria Nanoparticles on the Electrodeposited Zinc Coating's Growth: Interest of a TEM-Scale Investigation

International audienceThe study deals with a Zn-ceria nanocomposite coating synthesized by direct current electrodeposition. The aim of the study was to determine how the presence of the ceramic particles may affect the coating's growth. Distribution of the ceramic phase into the metallic matrix is deduced from a deep TEM characterization. It was observed that the formation of nanocomposite coating Was strongly governed by a preferential lateral growth of zinc. Nanoparticles were mainly located on the top-surface and in a lesser extent into the film's thickness. Optimization of the incorporated nanoparticules' rate is then discussed on the basis of hosting sites, such as grain boundaries