Electric lead field for a piecewise homogeneous volume conductormodel of the head

A new method is presented for computing the electric lead field of a realistic head shape model which has piecewise homogenous conductivity. The basic formulae are derived using the well-known reciprocity theorem. Previously described methods are also based upon this theorem, but these first calculate the electric potential inside the head by a scalar boundary element method (BEM), and then approximate the ohmic current density by some sort of gradient. In contrast, this paper proposes the direct evaluation of the ohmic current density by discretizing the vector Green's second identity which leads to a rector version of BEM. This approach also allows the derivation of the same equations for the three concentric spheres model as obtained by Rush and Driscoll (1969). The results of simulations on a spherical head model indicate that the use of a vector BEM leads to an improvement of accuracy in the computation of the ohmic current density with respect to those reported previously, in term of different measures of error     

Wind excitation of neighbouring tall buildings

There is a growing concern about the importance of interaction effects between neighbouring tall buildings subjected to wind loading. Available results indicate that both the peak dynamic response as well as the mean wind loads may increase substantially due to building interaction.An extensive wind-tunnel study of the interaction between two square prisms with a height-to-base length equal to six was undertaken at the LAC, UFRGS. Fifteen relative prism positions were studied, for wind orientations at every 15°, under smooth-uniform as well as turbulent-shear wind. Mean force and torsional moment coefficients for uniform flow were reported in previous publications. Herein, complete results for turbulent wind are given. In addition, the most important interaction effects observed under both flow conditions are discussed in detail.     

Transplantectomy today: indications and complications

Analysis of the indications for transplantectomy and its complications over a 12-year period. Over a total of 159 failure grafts, we performed 53 transplantectomies (33.3%). The percentage of complications was 16.9%. Three patients died (5.6%) during the more or less immediate post-operative period. In our experience, consistent and prolonged maintenance of immunosuppression should avoid the need for transplantectomy in a high percentage of grafts. Only 15 transplantectomies were made on 104 failure grafts after 6 months (14.4%). Our short but successful experience with embolization of 2 rejected grafts confirms the validity of this conservative alternative versus conventional surgical transplantectomy in selected cases.     

Health benefits of CLA – lessons from pig models in biomedical research

The objective of this review is to highlight the use of pig models for investigating safety, efficacy and the mechanisms of action of conjugated linoleic acid (CLA). Although CLA elicits positive effects in animal models and in vitro systems, a consistent concern in terms of translational research is that the health benefits observed by using these model systems cannot be extrapolated directly into humans. Conversely, the similarities between pigs and humans make the pig an ideal model for examining the health benefits of dietary supplements, functional foods and nutraceuticals. We have developed pig models of viral and bacterial infection to examine the preventive role of dietary CLA supplementation on virally induced immunosuppression and gut health, respectively. Results from these studies indicate that CLA significantly enhances the immune function while limiting the catabolic effects of uncontrolled immune and inflammatory responses. The scientific findings in pig models and human clinical trials demonstrate that CLA modulates immune responses in pigs and humans. Pig models of immunomodulation represent significant improvements over other animal models and in vitro systems because they mimic more closely the compartmentalization of the human immune system and the clinical presentation of human infectious, immune and inflammatory diseases.     

Humic fertilizers by oxiammoniation of hydrolyzed olive pits residues

Hydrolyzed olive pit residues from the production of furfural were ammoniated to obtain a nitrogenenriched humic fertilizer. Samples had been previously oxidized with nitric acid. The oxidized samples were further ammoniated in a batch reactor in the following range of experimental conditions: T = 80–210°C, , solid/liquid ratio, S/L = 0.5–2.8 w/w and reaction time, t = 1–4 h.Planning of experiments was made by statistical design and results were fitted by multiple non-lineal regression polynomials. The product consists of two fractions: a water soluble fraction which contains most of the nitrogen (10–13 wt%) and a solid fraction with a very low nitrogen content (<4.0 wt%), which is likely to be fixed during the oxidation step. The soluble fraction can be used as a humic fertilizer and the solid product as a soil conditioner.     

Multiphoton fluorescent images with a spatially varying background signal: a ML deconvolution method

By means of multiphoton laser scanning microscopy, neuroscientists can look inside the brain deeper than has ever been possible before. Multiphoton fluorescent images, as all optical images, suffer from degradation caused by a variety of sources (e.g. light dispersion and absorption in the tissue, laser fluctuations, spurious photodetection and staining deficiency). From a modelling perspective, such degradations can be considered the sum of stochastic noise and a background signal. Among the methods proposed in the literature to perform image deconvolution in either confocal or multiphoton fluorescent microscopy, Vicidomini et al. (2009) were the first to incorporate models for noise (a Poisson process) and background signal (spatially constant) in the context of regularized inverse problems. Unfortunately, the so-called split-gradient deconvolution method (SGM) they used did not consider possible spatial variations in the background signal. In this paper, we extend the SGM by adding a maximum-likelihood estimation step for the determination of a spatially varying background signal. We demonstrate that the assumption of a constant background is not always valid in multiphoton laser microscopy and by using synthetic and actual multiphoton fluorescent images, we evaluate the face of validity of the proposed method, and compare its accuracy with the previously introduced SGM algorithm.     

Production of furfural by acid hydrolysis of corncobs

Hydrolysis of corncobs for producing furfural was carried out in a pressurized batch reactor using superheated water and diluted sulphuric acid as catalyst. The range of experimental conditions was T=140–200°C and P=350–1550 kPa. Yields of furfural are reported as a function of reaction temperature, particle size, acid concentration and liquid/solid ratio. Attention has been focused on the solid residue remaining after the hydrolysis process, so that it can be further used as a humic fertilizer after oxiammoniation treatment.     

Both Specific Endothelial and Proximal Tubular Adam17 Deletion Protect against Diabetic Nephropathy

ADAM17 is a disintegrin and metalloproteinase capable of cleaving the ectodomains of a diverse variety of molecules including TNF-α, TGF-α, L-selectin, and ACE2. We have previously demonstrated that renal ADAM17 is upregulated in diabetic mice. The role of endothelial (eAdam17) and proximal tubular (tAdam17) Adam17 deletion in renal histology, modulation of the renin angiotensin system (RAS), renal inflammation, and fibrosis was studied in a mouse model of type 1 Diabetes Mellitus. Moreover, the effect of Adam17 deletion in an in vitro 3D cell culture from human proximal tubular cells under high glucose conditions was evaluated. eAdam17 deletion attenuates renal fibrosis and inflammation, whereas tAdam17 deletion decreases podocyte loss, attenuates the RAS, and decreases macrophage infiltration, α-SMA and collagen accumulation. The 3D in vitro cell culture reinforced the findings obtained in tAdam17KO mice with decreased fibrosis in the Adam17 knockout spheroids. In conclusion, Adam17 deletion either in the endothelial or the tubular cells mitigates kidney injury in the diabetic mice by targeting different pathways. The manipulation of Adam17 should be considered as a therapeutic strategy for treating DN.