Interactive 3D Simulation of Escher-like Impossible Worlds

figures and impossible worlds. Many of his works illustrate mathematical and geometrical concepts such as perspective and limits. Works by Escher have motivated scientists over the years to discover the mathematical foundations of his work, ultimately leading to applications that are able to model and render scenes similar to the ones created by Escher. Presented is an application that is capable of displaying a special class of impossible worlds that have been created by the artist. The software displays worlds that appear physically correct, but are connected in an impossible manner, similar to Escher’s Another World II or Relativity. Portal rendering is employed to create real-time interactive visualizations of such scenes, which can be freely explored by the user

Generation of advanced Escher-like spiral tessellations

In this paper, using both hand-drawn and computer-drawn graphics, we establish a method to generate advanced Escherlike spiral tessellations. We first give a way to achieve simple spiral tilings of cyclic symmetry. Then, we introduce several conformal mappings to generate three derived spiral tilings. To obtain Escher-like tessellations on the generated tilings, given pre-designed wallpaper motifs, we specify the tessellations’ implementation details. Finally, we exhibit a rich gallery of the generated Escher-like tessellations. According to the proposed method, one can produce a great variety of exotic Escher-like tessellations that have both good aesthetic value and commercial potential

Topology and morphology design of spherically reconfigurable homogeneous Modular Soft Robots (MSoRos)

Imagine a swarm of terrestrial robots that can explore an environment, and, upon completion of this task, reconfigure into a spherical ball and roll out. This dimensional change alters the dynamics of locomotion and can assist them to maneuver variable terrains. The sphere-plane reconfiguration is equivalent to projecting a spherical shell onto a plane, an operation which is not possible without distortions. Fortunately, soft materials have potential to adapt to this disparity of the Gaussian curvatures. Modular Soft Robots (MSoRos) have promise of achieving dimensional change by exploiting their continuum and deformable nature. We present topology and morphology design of MSoRos capable of reconfiguring between spherical and planar configurations. Our approach is based in geometry, where a platonic solid determines the number of modules required for plane-to-sphere reconfiguration and the radius of the resulting sphere, e.g., four `tetrahedron-based' or six `cube-based' MSoRos are required for spherical reconfiguration. The methodology involves: (1)inverse orthographic projection of a `module-topology curve' onto the circumscribing sphere to generate the spherical topology,(2)azimuthal projection of the spherical topology onto a tangent plane at the center of the module resulting in the planar topology, and (3)adjusting the limb stiffness and curling ability by manipulating the geometry of cavities to realize a physical finite-width, Motor-Tendon Actuated MSoRo. The topology design is shown to be scale invariant, i.e., scaling of base platonic solid is reflected linearly in spherical and planar topologies. The module-topology curve is optimized for the reconfiguration and locomotion ability using a metric that quantifies sphere-to-plane distortion. The geometry of the cavity optimizes for the limb stiffness and curling ability without compromising the actuator's structural integrity

New peptidic angiotensin II analogues their synthesis and pharmacological characterization

In this study we present the synthesis and pharmacological characterization of different classes of peptidic Angiotensin II (AngII) analogues modified principally at position 8. These analogues can be used to explain the conformational changes, which AngII receptors undergo upon ligand binding. The first class of AngII analogues synthesized were Tyr[superscript 4] -palmitoylated analogues of general structure [Sar[superscript 1] ,Y(O-Pal)[superscript 4] ,X]AngII, where X presented either Gly, Ala, Ile, Leu, Br[subscript 5]Phe (pentabromophenylalanine), D-[bêta]Nal (beta-naphtylalanine) or Phe. Binding studies on bovine adrenocortical membranes showed that these analogues keep their affinity for the AT[subscript 1] receptor despite palmitoylation having pK[subscript i] values around 8. Pharmacologically these analogues resemble their non-palmitoylated equivalents. All the analogues were antagonists of AT[subscript 1] , except [Sar[superscript 1] ,Y(O-Pal)[superscript 4] ]AngII, which exerted full agonistic properties. Furthermore, this study showed that palmitoylated antagonists exerted long-lasting antagonistic effect in vitro , which persisted for several hours, and that these analogues acted specifically and all the observed effects were driven via the AT[subscript 1] receptor. The second class of analogues contained a benzoylphenylalanine-like (Bpa) residue at the position 8 of AngII. Four new ligands, which were potentially photoactive were synthesized, three of which could be directly iodinated within the Bpa-moiety. Photolabeling studies revealed that two of the four tested analogues, [superscript 125]I-[Sar1 ,p ' -I-Bpa8 ]AngII and [superscript 125] I-[Sar[superscript 1] ,p' -NO[subscript 2] -Bpa[superscript 8]]AngII photolabeled the human AT[subscript 2] receptor (hAT[subscript 2] ) but did not photolabel the human AT[subscript 1] receptor (hAT[subscript 1] ). CNBr chemical digestion of the photolabeled hAT[subscript 2] complexes confirmed that the site of attachment of p' -I-Bpa[superscript 8] and p' -NO[subscript 2] -Bpa[superscript 8] corresponded to that of Bpa[superscript 8] previously reported to be situated in the 3rd TMD within M[superscript 128] -M[superscript 138] . Site-directed mutagenesis of hAT[subscript 1] and hAT[subscript 2] , where different mutations were introduced close to the previously reported contact points of Bpa[superscript 8] with the receptor, have shown that selective photolabeling of hAT[subscript 2] by [superscript 125]I-[Sar[superscript 1] ,p' -NO[subscript 2] -Bpa[superscript 8] ]AngII resulted from an increased selectivity of Bpa and p' -NO[subscript 2] -Bpa for M presented in the site of attachment of hAT[subscript 2] . Furthermore, these results indicated that M[superscript 128] and M[superscript 138] from the 3rd TMD of hAT[subscript 2] equally contribute to the binding of position 8 of AngII

Cell-associated hemolysis activity in the clinical strain of Pseudomonas fluorescens MFN1032

<p>Abstract</p> <p>Background</p> <p>MFN1032 is a clinical <it>Pseudomonas fluorescens </it>strain able to grow at 37°C. MFN1032 cells induce necrosis and apoptosis in rat glial cells at this temperature. This strain displays secretion-mediated hemolytic activity involving phospholipase C and cyclolipopeptides. Under laboratory conditions, this activity is not expressed at 37°C. This activity is tightly regulated and is subject to phase variation.</p> <p>Results</p> <p>We found that MFN1032 displays a cell-associated hemolytic activity distinct from the secreted hemolytic activity. Cell-associated hemolysis was expressed at 37°C and was only detected <it>in vitro </it>in mid log growth phase in the presence of erythrocytes. We studied the regulation of this activity in the wild-type strain and in a mutant defective in the Gac two-component pathway. GacS/GacA is a negative regulator of this activity. In contrast to the <it>Pseudomonas fluorescens </it>strains PfO-1 and Pf5, whose genomes have been sequenced, the MFN1032 strain has the type III secretion-like genes <it>hrc</it>RST belonging to the <it>hrpU </it>operon. We showed that disruption of this operon abolished cell-associated hemolytic activity. This activity was not detected in <it>P.fluorescens </it>strains carrying similar <it>hrc </it>genes, as for the <it>P. fluorescens </it>psychrotrophic strain MF37.</p> <p>Conclusions</p> <p>To our knowledge this the first demonstration of cell-associated hemolytic activity of a clinical strain of <it>Pseudomonas fluorescens</it>. Moreover, this activity seems to be related to a functional <it>hrpU </it>operon and is independent of biosurfactant production. Precise link between a functional <it>hrpU </it>operon and cell-associated hemolytic activity remains to be elucidated.</p

Nonlinear Evolution Equations: Analysis and Numerics

The workshop was devoted to the analytical and numerical investigation of nonlinear evolution equations. The main aim was to stimulate a closer interaction between experts in analytical and numerical methods for areas such as wave and Schrödinger equations or the Navier–Stokes equations and fluid dynamics

Digital Citizen Participation – Involving Citizens Through Immersive Systems in Urban Planning

Citizen participation is a democratic practice that became, especially on a local level, an important mean for the public to be included in the development of their immediate surrounding. With the digitalization of work and social life also the digitalization of the public sector, including governmental action, began. This process, as a research discipline called digital government, includes addressing how the interaction between citizens and their state should be designed. A meaningful way to do so are digital platforms that enable participation in governmental action. Digital Citizen Participation, a concept introduced in this dissertation, tries to include recent technological innovations in e-Participation platform design. This dissertation argues that these innovations might help overcome general barriers in participation processes. When it comes to construction projects in urban environments for example, public debates and protests may arise if architectural plans remain unshared or are not sufficiently accessible for the citizens they might affect. To involve the public affected by urban planning, offering easily graspable visualizations for citizens is key. This dissertation deals with the participation of citizens in urban planning through an e-Participation platform that makes use of immersive technologies such as Augmented and Virtual Reality. In this work, this idea is investigated through a design science research approach that uses qualitative and quantitative methods. While the first qualitative study puts for-ward a set of meta-requirements and design principles based on interviews with 27 individuals, the second study (n=339) and third study (n=382) evaluate quantitatively a prototype based on those design principles. The used methods are adequately contex-tualized and, in the end, a final prototype of the platform is demonstrated. This allows to show findings concerning the forms and levels of participation citizens and initiators are interested in when using immersive systems for public participation, and how an ideal platform should be designed. Among many other findings, the studies show that citizens have a high interest in using immersive systems for public participation and find their qualities for visualization to be highly valuable

Inhibition of the growth of Bacillus subtilis DSM10 by a newly discovered antibacterial protein from the soil metagenome

A functional metagenomics based approach exploiting the microbiota of suppressive soils from an organic field site has succeeded in the identification of a clone with the ability to inhibit the growth of Bacillus subtilis DSM10. Sequencing of the fosmid identified a putative β-lactamase-like gene abgT. Transposon mutagenesis of the abgT gene resulted in a loss in ability to inhibit the growth of B. subtilis DSM10. Further analysis of the deduced amino acid sequence of AbgT revealed moderate homology to esterases, suggesting that the protein may possess hydrolytic activity. Weak lipolytic activity was detected; however the clone did not appear to produce any β-lactamase activity. Phylogenetic analysis revealed the protein is a member of the family VIII group of lipase/esterases and clusters with a number of proteins of metagenomic origin. The abgT gene was sub-cloned into a protein expression vector and when introduced into the abgT transposon mutant clones restored the ability of the clones to inhibit the growth of B. subtilis DSM10, clearly indicating that the abgT gene is involved in the antibacterial activity. While the precise role of this protein has yet to fully elucidated, it may be involved in the generation of free fatty acid with antibacterial properties. Thus functional metagenomic approaches continue to provide a significant resource for the discovery of novel functional proteins and it is clear that hydrolytic enzymes, such as AbgT, may be a potential source for the development of future antimicrobial therapies