50 research outputs found
Forest Focus Monitoring Database System - Executive Summary Report 2003 Level II Data
This Executive Report presents the results obtained from all processing stages (data reception, validation checks Âż compliance, conformity, uniformity) for submitted data referring to the monitoring year 2003. This report presents the results at the end of the processing phase after data have been re-submitted in 2007. It presents in addition a brief comment on the data status for each NFC, for the reporting year, with respect to the parameter assessed and including analyses of spatial variability of data and temporal trends of parameters.JRC.H.7-Land management and natural hazard
Forest Focus Monitoring Database System - Technical Report 2003 Level II Data
Forest Focus (Regulation (EC) No 2152/2003) is a Community scheme for harmonized, broad-based, comprehensive and long-term monitoring of European forest ecosystems. Under this scheme the monitoring of air pollution effects on forests is carried out by participating countries on the basis of the systematic network of observation points (Level I) and of the network of observation plots for intensive and continuous monitoring (Level II).
According to Article 15(1) of the Forest Focus Regulation Member States shall annually, through the designated authorities and agencies, forward to the Commission geo-referenced data gathered under the scheme, together with a report on them by means of computer telecommunications and/or electronic technology. For managing the data JRC has implemented a Forest Focus Monitoring Database System.
This Technical Report presents the results obtained from all processing stages (data reception, validation checks Âż compliance, conformity, uniformity) for submitted data referring to the monitoring year 2003. This report presents the results at the end of the processing phase after data have been re-submitted in 2007. It presents in addition a brief comment on the data status for each NFC, for the reporting year, with respect to the parameter assessed and including analyses of spatial variability of data and temporal trends of parameters.JRC.H.7-Land management and natural hazard
Explicit expressions for the estimation of the elastic constants of lamellar bone as a function of the volumetric mineral content using a multi-scale approach
[EN] In this work, explicit expressions to estimate all the transversely isotropic elastic constants of lamellar bone as a function of the volumetric bone mineral density (BMD) are provided. The methodology presented is based on the direct homogenization procedure using the finite element method, the continuum approach based on the Hill bounds, the least-square method and the mean field technique. Firstly, a detailed description of the volumetric content of the different components of bone is provided. The parameters defined in this step are related to the volumetric BMD considering that bone mineralization process occurs at the smallest scale length of the bone tissue. Then, a thorough description provides the details of the numerical models and the assumptions adopted to estimate the elastic behaviour of the forward scale lengths. The results highlight the noticeable influence of the BMD on the elastic modulus of lamellar bone. Power law regressions fit the Young's moduli, shear stiffness moduli and Poisson ratios. In addition, the explicit expressions obtained are applied to the estimation of the elastic constants of cortical bone. At this scale length, a representative unit cell of cortical bone is analysed including the fibril orientation pattern given by Wagermaier et al. (Biointerphases 1:1-5, 2006) and the BMD distributions observed by Granke et al. (PLoS One 8:e58043, 2012) for the osteon. Results confirm that fibril orientation arrangement governs the anisotropic behaviour of cortical bone instead of the BMD distribution. The novel explicit expressions obtained in this work can be used for improving the accuracy of bone fracture risk assessment.The authors acknowledge the Ministerio de Economia y Competitividad for the financial support received through the project DPI2013-46641-R and to the Generalitat Valenciana for Programme PROMETEO 2016/007. The authors declare that they have no conflict of interestVercher MartĂnez, A.; Giner Maravilla, E.; Belda, R.; Aigoun, A.; Fuenmayor Fernández, F. (2018). Explicit expressions for the estimation of the elastic constants of lamellar bone as a function of the volumetric mineral content using a multi-scale approach. Biomechanics and Modeling in Mechanobiology. 17(2):449-464. https://doi.org/10.1007/s10237-017-0971-xS449464172Akiva U, Wagner HD, Weiner S (1998) Modelling the three-dimensional elastic constants of parallel-fibred and lamellar bone. J Mater Sci 33:1497–1509Ascenzi A, Bonucci E (1967) The tensile properties of single osteons. Ana Rec 158:375–386Barbour KE, Zmuda JM, Strotmeyer ES, Horwitz MJ, Boudreau R, Evans RW, Ensrud K, Petit MA, Gordon CL, Cauley JA (2013) Correlates of trabecular and cortical volumetric bone mineral density of the radius and tibia older men: the osteoporotic fractures in men study. 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Biodiversity assessment in forests - from genetic diversity to landscape diversity
Assessing biodiversity in forests requires a reliable and sustainable monitoring concept, which must include all levels of diversity, the genetic, the species and the landscape level. Diversity studies should not be reduced to quantitative analysis, but qualitative interpretations are an important part for the understanding of the results. Also, the linkage of terrestrial data and remote sensing data as well the implementation of abiotic and biotic data collected on existing monitoring systems are useful sources to analyse cause-effect relationships and interactions between the different aspects of diversity
Echocardiographic Diagnosis of Extrapericardial Tamponade Due to Dilated Gastric Roll following Oesophagectomy
Sources and Distribution Systems of Irrigation Water and Their Potential Risks for Crop Health
Myocardial ischemia caused by postoperative malfunction of a patent internal mammary coronary arterial graft
The internal mammary artery is used with increasing frequency for myocardial revascularization. However, preoperative coronary angiography does not always provide adequate visualization of subclavian arteries. If a proximal subclavian artery stenosis exists or develops in a patient who has myocardial revascularization with the internal mammary artery, graft malfunction can occur resulting in myocardial ischemia. We have identified four cases of internal mammary artery graft malfunction at our own institution and identified an additional 12 cases from the literature. These 16 cases are analyzed for age, sex, time of onset of symptoms, clinical findings, method of revascularization, and long-term follow-up. Sixty-three percent of the patients were men, and the mean age was 52.9 +/- 9.0 years. Onset of symptoms occurred after a mean interval of 25.1 months from the time of myocardial revascularization. Three patients had asymptomatic reversal of flow in the internal mammary artery as diagnosed by coronary arteriography during routine follow-up examination before 1980. One death after internal mammary artery-coronary bypass grafting was related to immediate malfunction. In the remaining 12 patients with symptomatic malfunction, all but one were treated by placement of a carotid-subclavian bypass graft with no mortality. Relief of myocardial ischemia was complete in 93% of the patients with a mean follow-up of 29.3 months. Carotid-subclavian bypass grafting appears to be the treatment of choice for the usual management of internal mammary artery graft dysfunction. Careful preoperative evaluation and postoperative follow-up of the subclavian arteries, even by simple comparison of bilateral arm blood pressure should help reduce the incidence of this syndrome
Microfibril orientation dominates the microelastic properties of bone tissue at the lamellar length scale
International audience12 Hide Figures Abstract Introduction Methods Results Discussion Acknowledgments Author Contributions References Reader Comments (0) Figures Abstract The elastic properties of bone tissue determine the biomechanical behavior of bone at the organ level. It is now widely accepted that the nanoscale structure of bone plays an important role to determine the elastic properties at the tissue level. Hence, in addition to the mineral density, the structure and organization of the mineral nanoparticles and of the collagen microfibrils appear as potential key factors governing the elasticity. Many studies exist on the role of the organization of collagen microfibril and mineral nanocrystals in strongly remodeled bone. However, there is no direct experimental proof to support the theoretical calculations. Here, we provide such evidence through a novel approach combining several high resolution imaging techniques: scanning acoustic microscopy, quantitative scanning small-Angle X-ray scattering imaging and synchrotron radiation computed microtomography. We find that the periodic modulations of elasticity across osteonal bone are essentially determined by the orientation of the mineral nanoparticles and to a lesser extent only by the particle size and density. Based on the strong correlation between the orientation of the mineral nanoparticles and the collagen molecules, we conclude that the microfibril orientation is the main determinant of the observed undulations of microelastic properties in regions of constant mineralization in osteonal lamellar bone. This multimodal approach could be applied to a much broader range of fibrous biological materials for the purpose of biomimetic technologies