The influence of weathering and organic matter on heavy metals lability in silicatic, Alpine soils

We investigated the effect of organic matter and weathering on the lability and solid phase speciation of heavy metals (Cd, Cr, Cu, Ni, Pb, Zn) in two contrasting subalpine regions in the Italian Alps. Cr, Ni and Cu could be linked to weathering. This was not the case for Pb. Since organic matter (OM) influences the solid phase speciation of heavy metals, the total organic C and N content, the C and N content of different density fractions of OM and also of the labile (oxidised by H₂O₂) and stable (H₂O₂-resistant) fractions were determined. Soil OM stocks were high and soils on north-facing slopes had more OM than the south-facing sites to which they were paired. Density measurements and the H₂O₂ fractionation indicated that the higher OM content on north-facing sites was due to an accumulation of weakly degraded organic material. Due to higher weathering intensity on north-facing sites, the abundance of the EDTA-extractable heavy metals was higher than on south-facing sites. All EDTA-extractable heavy metals showed a good correlation to the water-soluble phenolic concentrations which indicates that the metals were probably translocated as metal-organic complexes. Pb and Cu correlate not only to the light (density < 1 g/cm³) and labile, organic fraction but also to the heavy (density > 2 g/cm³) and stable fraction. High-mountain ecosystems like the Alps are sensitive to changing environmental conditions such as global warming. A warmer climate and the more favourable conditions it brings for biological activity, especially at cooler sites, will probably lead in the short- to mid-term to an increased loss of accumulated, weakly degraded OM. As the Pb and Cu content is significantly related to the labile organic matter pools, the risk exists that an increase in OM mineralisation could affect the storage capacity and mobility of these metals in soils.     

Physical and compressional characteristics of a novel 3D fibrous structure – application in comparison between PU foam and 3D fibrous structure

The question of the recycling of the polyurethane (PU) foam, especially in the automotive industry represents one of the main technology thrust and challenge of the car manufacturers and the Original Equipment Manufacturers’ (OEM) since 2000. Indeed, it is nowadays necessary for car industry to promote ecological methods of development in regard to new consumer sensibility. New textile products present the best alternative solutions to answer this issue of replacement of the PU foam. Based on this fact, a new three-dimensional (3D) fibrous structure made of polyester (PET) material has been developed in order to replace PU foam in automotive trim. These new manufactured 3D fibrous structures are laminated with needle-punched and spun-bonded sheets. The sheets are made of 100% PET, in order to obtain a mono component product. Characterization of physical and mechanical properties of these new 3D fibrous structures, testing methods have to be developed. Based on the automotive specifications, a methodology has been set up to test the compression behavior of these new products. In order to answer the issue of replacement, some PU foam products have also been characterized, and comparisons with alternative products have been conducted. The results of this study show interesting properties of the new 3D fibrous structure in terms of compression behavior when compared to the PU foam.     

Toward a spectroscopic hemogram: Raman spectroscopic differentiation of the two most abundant leukocytes from peripheral blood

The first response to infection in the blood is mediated by leukocytes. As a result crucial information can be gained from a hemogram. Conventional methods such as blood smears and automated sorting procedures are not capable of recording detailed biochemical information of the different leukocytes. In this study, Raman spectroscopy has been applied to investigate the differences between the leukocyte subtypes which have been obtained from healthy donors. Raman imaging was able to visualize the same morphological features as standard staining methods without the need of any label. Unsupervised statistical methods such as principal component analysis and hierarchical cluster analysis were able to separate Raman spectra of the two most abundant leukocytes, the neutrophils and lymphocytes (with a special focus on CD4(+) T-lymphocytes). For the same cells a classification model was built to allow an automated Raman-based differentiation of the cell type in the future. The classification model could achieve an accuracy of 94% in the validation step and could predict the identity of unknown cells from a completely different donor with an accuracy of 81% when using single spectra and with an accuracy of 97% when using the majority vote from all individual spectra of the cell. This marks a promising step toward automated Raman spectroscopic blood analysis which holds the potential not only to assign the numbers of the cells but also to yield important biochemical information.     

Introducing lateral thinking in search engines

Decomposing a very complex problem into smaller subproblems that are much easier to solve is not a new idea. The “Parisian Approach”[9] applies this principle extensively to shatter complexity by cutting down the original problem into many small subproblems that are then globally optimized thanks to an evolutionary algorithm. This paper describes how this approach has been used to interactively evolve a user profile to be used by a search engine. User queries are rewritten thanks to the evolved profile, resulting in an increased diversity in the retrieved documents that is showing an interesting property: even though precision is lost, retrieved documents relate both to the user’s query and to his areas of interest in a manner that evokes “lateral thinking”. This paper describes ELISE, an Evolutionary Learning Interactive Search Engine that interactively evolves rewriting modules and rules (some kind of elaborated user profile) along a Parisian Approach. Results obtained over a public domain benchmark (Cystic Fibrosis Database) are presented and discussed. This research is partly funded by Novartis-Pharma (IK@N/KE)     

The virtual fields method with piecewise virtual fields

This paper deals with the identification of constitutive parameters of materials from whole-field strain data. The inverse identification procedure used is the virtual fields method. It is based on the principle of virtual work written with particular virtual fields. A keypoint of the method is the determination of the virtual fields since they directly extract the unknown parameters from the measured fields. The main improvement of the present paper is to show the feasibility of piecewise virtual fields. These piecewise virtual fields are defined by virtual nodal displacements. The headlines of the virtual fields method are recalled in the first part of the paper. The procedure leading to the definition of piecewise virtual fields is then described. Numerical simulations finally illustrate the relevance of the approach and its sensitivity to noisy data.     

Choroidal hemangioma: MR findings and differentiation from uveal melanoma

Transgenic mice (T26) bearing the envelope, regulatory, and accessory genes of HIV- I develop renal disease resembling human HIV-associated nephropathy (HIVAN). Effects of vehicle (VEH) and the angiotensin-converting enzyme inhibitor captopril (CAP) were examined in wild-type (WT) or T26 mice treated from 7 to 100 d of age. Mortality was lower in CAP T26 mice (30 mg/kg: 8%; 100 mg/kg: 12%) than VEH T26 mice (52%). The urinary protein/creatinine ratio was increased in VEH T26 mice (19.5+/-7.60) versus WT mice (6.1+/-0.83), but not in low-dose (7.3+/-0.94) or high-dose (8.2+/-1.02) CAP T26 mice. Blood urea nitrogen was higher in VEH T26 mice (52+/-16.2 mg/dl) than VEH WT mice (24+/-0.8). Blood urea nitrogen was also elevated in CAP WT (high dose: 43+/-2.1 mg/dl) and T26 mice (high dose: 42+/-2.4 mg/dl). Glomerular injury was higher in VEH T26 mice (6.8+/-0.58) than VEH WT mice (0.2+/-0.08) or CAP T26 mice (low dose: 1.1+/-0.17; high dose: 0.7+/-0.13). Tubulointerstitial injury was also greater in VEH T26 mice (1.1+/-0.10) than VEH WT mice (0.2+/-0.08) or CAP T26 mice (low dose: 0.4+/-0.10; high dose: 0.3+/-0.10). These data validate recent nonrandomized studies of captopril in HIV-infected patients, and suggest that an angiotensin-converting enzyme substrate is an important mediator in HIVAN. A randomized placebo-controlled trial of captopril in HIVAN may be warranted.     

Clinicopathologic features of retinoblastoma after primary chemoreduction

BACKGROUND: Cytotoxic T cells can induce target cell lysis and apoptosis by different pathways. The interactions of CD95 antigen (Fas) with its ligand (CD95L) and of tumor necrosis factor (TNF)-alpha with its receptor (TNF-R1) lead to apoptotic cell death. Recently, conflicting studies have been published concerning the expression and the role of CD95L in allograft rejection and tolerance. METHODS: In this study, the intragraft expression of CD95/CD95L and TNF-alpha and the frequency and distribution of apoptotic cells were compared in a model of heterotopic cardiac allograft in the rat in which recipients were either not treated (acute rejection) or pretreated with donor-specific blood transfusion (tolerant). RESULTS: In the acutely rejected allografts, a peak in the expression of CD95L and TNF-alpha and in the number of apoptotic cells was observed during the first week after transplantation; apoptotic cells were confined to graft-infiltrating cells. In the tolerated allografts, however, levels of graft-infiltrating cell apoptosis and CD95L and TNF-alpha expression during the same period of time were dramatically lower. The expression of Fas was constitutive and was not modulated during acute rejection or tolerance. CONCLUSION: This down-regulation of CD95L and TNF-alpha in allografts rendered tolerant by donor-specific transfusion suggests a role for apoptosis-inducing pathways in acute allograft rejection.     

Compact Unstructured Representations for Evolutionary Design

This paper proposes a few steps to escape structured extensive representations for objects, in the context of evolutionary Topological Optimum Design (TOD) problems: early results have demonstrated the potential power of Evolutionary methods to find numerical solutions to yet unsolved TOD problems, but those approaches were limited because the complexity of the representation was that of a fixed underlying mesh. Different compact unstructured representations are introduced, the complexity of which is self-adaptive, i.e. is evolved by the algorithm itself. The Voronoi-based representations are variable length lists of alleles that are directly decoded into object shapes, while the IFS representation, based on fractal theory, involves a much more complex morphogenetic process. First results demonstrates that Voronoi-based representations allow one to push further the limits of Evolutionary Topological Optimum Design by actually removing the correlation between the complexity of the representations and that of the discretization. Further comparative results among all these representations on simple test problems seem to indicate that the complex causality in the IFS representation disfavors it compared to the Voronoi-based representations.