Morphological and stance interpolations in database for simulating bipedalism of virtual humans

We present a computer tool for testing walk hypotheses for human beings. This tool aims to generate plausible walking movements according to anatomical knowledge. To this end, we introduce an interpolation method based, on one hand, on morphological data and, on the other hand, on stance hypotheses and on footprint hypotheses. We want to test these hypotheses for application to the reconstruction of early hominid walking. We interpolate from a specific representation of the movement—a characteristic relative displacement. First, we use a motion capture system to acquire real movements of a walk cycle, and we propose to represent them by using a generic parametric model. Thus, we create a database of movements. The interpolation process produces, thanks to this database, a retargeted motion adapted to the morphology of the considered targeted skeleton. The interpolation is done according to three main hypotheses. The first concerns the reference stance, the second the lateral spacing between the feet, and the third the length of the step. In the introduction, we refer to related work. Then we propose the two following points of our method: the 3D representation of our motion representation and the multidimensional interpolation method applied to this representation. The interpolation method addresses morphological adaptation, and the use of an inverse kinematics solver addresses the computation of skeleton movements. The self-coherent validation process aims to test the coherence of the proposed method. The results propose an application to a virtual skeleton of Lucy (Australopithecus afarensis A.L. 288-1) reconstructed from real data. Finally, the relevance of the method for anthropological investigations and for animation purposes is discussed and future work is discussed with respect to the limitations of the proposed method.     

Thioether Analogues of Disulfide‐Bridged Cyclic Peptides Targeting Death Receptor 5: Conformational Analysis,Dimerisation and Consequences for Receptor Activation

Cyclic peptides containing redox‐stable thioether bridges might provide a useful alternative to disulfide‐bridged bioactive peptides. We report the effect of replacing the disulfide bridge with a lanthionine linkage in a 16‐mer cyclic peptide that binds to death receptor 5 (DR5, TRAIL‐R2). Upon covalent oligomerisation, the disulfide‐bridged peptide has previously shown similar behaviour to that of TNF‐related apoptosis inducing ligand (TRAIL), by selectively triggering the DR5 cell death pathway. The structural and biological properties of the DR5‐binding peptide and its desulfurised analogue were compared. Surface plasmon resonance (SPR) data suggest that these peptides bind DR5 with comparable affinities. The same holds true for dimeric versions of these peptides: the thioether is able to induce DR5‐mediated apoptosis of BJAB lymphoma and tumorigenic BJELR cells, albeit to a slightly lower extent compared to its disulfide homologue. NMR analysis revealed subtle variation in the conformations of the two peptides and suggests that the thioether peptide is slightly less folded than its disulfide homologue. These observations could account for the different capability of the two dimers to cluster DR5 receptors on the cell surface and to trigger apoptosis. Nevertheless, our results suggest that the thioether peptide is a potential candidate for evaluation in animal models.     

Ultrathin PECVD epitaxial Si solar cells on glass via low‐temperature transfer process

Fabrication of high‐quality ultrathin monocrystalline silicon layers and their transfer to low‐cost substrates are key steps for flexible electronics and photovoltaics. In this work, we demonstrate a low‐temperature and low‐cost process for ultrathin silicon solar cells. By using standard plasma‐enhanced chemical vapor deposition (PECVD), we grow high‐quality epitaxial silicon layers (epi‐PECVD) from SiH₄/H₂ gas mixtures at 175 °C. Using secondary ion mass spectrometry and transmission electron microscopy, we show that the porosity of the epi‐PECVD/crystalline silicon interface can be tuned by controlling the hydrogen accumulation there. Moreover, we demonstrate that 13–14% porosity is a threshold above which the interface becomes fragile and can easily be cleaved. Taking advantage of the H‐rich interface fragility, we demonstrate the transfer of large areas (∽10 cm²) ultrathin epi‐PECVD layers (0.5–5.5 µm) onto glass substrates by anodic bonding and moderate annealing (275–350 °C). The structural properties of transferred layers are assessed, and the first PECVD epitaxial silicon solar cells transferred on glass are characterized. Copyright © 2016 John Wiley & Sons, Ltd.     

A Cloud Rise Model for Dust and Soot from High Explosive Detonations

Traditionally, the evolution and rise of the dust and soot cloud resulting from high explosive detonations has been divided into two stages, with specific models used for each stage. In this study, based on the assumption that cloud formation progresses smoothly from stage to stage, a simple cloud rise model has been developed based on three sets of field tests of high explosive detonations (25×10⁻³ to 4.5 kg of detasheet and C‐4). This model provides a good fit to observations and measurements of clouds from detonations both at ground level and 1 m above the ground. It was also found that the detonation height has a noticeable influence on cloud rise before reaching its effective height, but the influence is minor on the subsequent cloud rise.     

Production vs. respiration in river systems: an indicator of an "ecological status"

The Riverstrahler model of ecological functioning of large drainage networks validated on the Seine river system has been used for calculating the seasonal variations of Production and Respiration at various spatial scales (e.g. according to river orders). Based on the measurements of biological processes, the P/R ratio has led to an evaluation of the "ecological functioning", beyond the notion of "good ecological status". Furthermore, the effects, on the P/R ratio, of the geomorphological and climate factors characterizing the Hydro-Eco-Regions (HER) of the Seine watershed have been quantitatively explored with the model. Whereas one finds a typical upstream-downstream pattern of the P/R ratio variations under the traditional rural conditions that prevailed in the Seine basin until the end of the 18th century, this pattern is strongly affected by the changes in urban populations and the implementation of wastewater collection and treatment, more than by the specificity of the physical factors characterizing the different HER. We have also found that autotrophy (a P/R ratio >1) might leads to eutrophication symptoms when P exceeds 1-2 mg C m(-2) d(-1) and that heterotrophy of the system (P/R ratio< 1) would reveal organic pollution when R exceeds 1-2 mg C m(-2) d(-1), stocks and fluxes of organic matter being expressed in carbon unit. Consequently, the P/R ratio appears as a good indicator of the perturbations caused by human activities in the watershed. The Riverstrahler model is able to quantify this effect.     

Mineralogy of air-pollution-control residues from a secondary lead smelter: environmental implications

The mineralogy and solubility of air-pollution-control (APC) residues from a secondary lead (Pb) smelter have been studied on samples from the Príbram smelter, Czech Republic, recycling car batteries, with the emphasis on their potential environmental effect. The presence of dominant anglesite (PbSO4) and laurionite (Pb(OH)Cl) was observed in a sintered residue from after-burning chambers (800-1000 degrees C). In contrast, low-temperature Pb-bearing phases, such as KCl x 2PbCl2 and caracolite (Na3Pb2(SO4)3Cl), were detected in the major APC residue from bag-type fabric filters. Metallic elements, zinc (Zn), cadmium (Cd), and tin (Sn) were found homogeneously distributed within this residue. The formation of anglesite, cotunnite (PbCl2), (Zn,Cd)2SnO4, and (Sb,As)2O3 was observed during the sintering of this APC residue at 500 degrees C in a rotary furnace. The 168 h leaching test on filter residue, representing the fraction that may escape the flue gas treatment system, indicated rapid release of Pb and other contaminants. Caracolite and KCl x 2PbCl2 are significantly dissolved, and anglesite and cotunnite form the alteration products, as was confirmed by mineralogical analysis and PHREEQC-2 modeling. The observed Pb-bearing chlorides have significantly higher solubility than anglesite and, following emission from the smelter stack, can readily dissolve, transferring Pb into the environmental milieu (soils, water, inhabited areas).     

Ability of naloxone to enhance the colonoscopic appearance of normal colon vasculature and colon vascular ectasias

OBJECTIVE: To compare the safety and efficacy of high-dose intravenous (IV) nitroglycerin with those of IV magnesium sulfate for acute tocolysis of preterm labor. METHODS: Thirty-one women with preterm labor before 35 weeks' gestation were assigned randomly to IV magnesium sulfate or IV nitroglycerin for tocolysis. Preterm labor was defined as the occurrence of at least two contractions in 10 minutes, with cervical change or ruptured membranes. Acute tocolysis was defined as tocolysis for up to 48 hours. Magnesium sulfate was administered as a 4-g bolus, then at a rate of 2-4 g/h. Nitroglycerin was administered as a 100-microg bolus, then at a rate of 1- to 10-microg/kg/min. The primary outcome measure was achievement of at least 12 hours of successful tocolysis. RESULTS: Thirty patients were available for analysis. There were no significant differences in gestational age, cervical dilation, or incidence of ruptured membranes between groups at the initiation of tocolysis. Successful tocolysis was achieved in six of 16 patients receiving nitroglycerin, compared with 11 of 14 receiving magnesium sulfate (37.5 versus 78.6%, P = .033). Tocolytic failures (nitroglycerin versus magnesium sulfate) were due to persistent contractions with cervical change or rupture of previously intact membranes (five of 16 versus two of 14), persistent hypotension (four of 16 versus none of 14), and other severe side effects (one of 16 versus one of 14). Maternal hemodynamic alterations were more pronounced in patients who received nitroglycerin, and 25% of patients assigned to nitroglycerin treatment had hypotension requiring discontinuation of therapy. CONCLUSION: Tocolytic failures were more common with nitroglycerin than with magnesium sulfate. The hemodynamic alterations noted in patients receiving nitroglycerin, including a 25% incidence of persistent hypotension, might limit the usefulness of IV nitroglycerin for the acute tocolysis of preterm labor.     

Effects of neurotrophins on embryonic retinal outgrowth

In the literature it is generally assumed that venous reflux within the radicular veins is prevented by the presence of bicuspid valves and narrowing of the transdural part of these vessels. Recently, we performed a human cadaver study of the internal vertebral venous plexus. Surprisingly, a large number of radicular and perimedullary veins appeared to be filled with Araldite CY 221 mixture, after injection of this material into the vertebral venous system, implicating reflux via the radicular veins and suggesting insufficiency of the presumed anti-reflux mechanism. Therefore, it was decided to study the radicular veins in order to determine and to investigate the presence or absence of anti-reflux mechanisms within this system. The vertebral venous systems of ten fresh human cadavers, between 64 and 93 years of age, were injected with Araldite CY 221 mixture. After polymerization, all cadavers were dissected and the spinal nerve sheaths, including nerve roots, radicular veins and epidural veins, were excised as a whole. After macroscopical examination, serial sections (40 microm) were cut on a freezing microtome and stained in Von Gieson medium. Every third section was stained immunohistochemically with smooth muscle antigen (SMA), to visualize smooth muscle cells. In all cadavers, a number of intradural radicular veins was filled with Araldite. Employing microscopical examination, no bicuspid valves were found. However, four structures were encountered that might serve as ananti-reflux-mechanism: 1) intravenous dural folds, 2) meandrous configuration, and 3) narrowing of the radicular veins at the point of penetration of the dura mater, and 4) varying numbers of smooth muscle fibers in the walls of the intradural and extradural parts of the radicular veins. Reflux via the radicular veins seems to be a physiological phenomenon. Structural valves have not been encountered during this study. Intravenous dural folds, meandrous configuration and narrowing of the transdural part of the radicular veins, and the presence of large numbers of smooth muscle cells in the radicular venous walls suggest the existence of a dynamic reflux-regulating system that has the ability to increase the intravascular resistance under conditions of venous hyperpression, in order to protect the spinal cord from venous pressure waves. Possibly, venous reflux via the radicular veins has a role in selective cooling of the spinal cord.     

Differences in prostate size between patients from University and Veterans Affairs Medical Center populations

We have previously determined that Nippostrongylus brasiliensis secretes three monomeric nonamphiphilic (G1na) variants of acetylcholinesterase (AChE) with broadly similar properties. In this study we have examined AChE expression in somatic extracts of N. brasiliensis and report the identification of an additional enzyme which is not secreted. The enzyme was resolved by sucrose density gradient centrifugation with a sedimentation coefficient of 10.2 S which was shifted to 9.4 S in the presence of Triton X-100, identifying the enzyme as a tetrameric amphiphilic (G4a) form. The amphiphilic properties of this enzyme were confirmed by charge-shift electrophoresis, in which migration was accelerated by interaction with sodium deoxycholate. The enzyme showed low activity with butyrylthiocholine, and a Michaelis constant of 91 +/- 13 microM for acetylthiocholine was determined. It was highly sensitive to the AChE-specific inhibitor bis (4-allyldimethylammoniumphenyl)pentan-3-one dibromide, with an IC50 of 6.5 +/- 0.4 microM, but was also inhibited by the butyrylcholinesterase-specific inhibitor tetramonoisopropylpyrophosphortetramide, albeit with a higher IC50 of 46.5 +/- 6.1 microM. This enzyme can therefore be distinguished from the secreted AChEs by its amphiphilic properties, sedimentation in sucrose gradients, and sensitivity to cholinesterase inhibitors.