Cross-Platform Presentation of Interactive Volumetric Imagery

Volume data is useful across many disciplines, not just medicine. Thus, it is very important that researchers have a simple and lightweight method of sharing and reproducing such volumetric data. In this paper, we explore some of the challenges associated with volume rendering, both from a classical sense and from the context of Web3D technologies. We describe and evaluate the pro- posed X3D Volume Rendering Component and its associated styles for their suitability in the visualization of several types of image data. Additionally, we examine the ability for a minimal X3D node set to capture provenance and semantic information from outside ontologies in metadata and integrate it with the scene graph

Effect of metallic walls on dynamos generated by laminar boundary-driven flow in a spherical domain

We present a numerical study of dynamo action in a conducting fluid encased in a metallic spherical shell. Motions in the fluid are driven by differential rotation of the outer metallic shell, which we refer to as "the wall". The two hemispheres of the wall are held in counter-rotation, producing a steady, axisymmetric interior flow consisting of differential rotation and a two-cell meridional circulation with radial inflow in the equatorial plane. From previous studies, this type of flow is known to maintain a stationary equatorial dipole by dynamo action if the magnetic Reynolds number is larger than about 300 and if the outer boundary is electrically insulating. We vary independently the thickness, electrical conductivity, and magnetic permeability of the wall to determine their effect on the dynamo action. The main results are: (a) Increasing the conductivity of the wall hinders the dynamo by allowing eddy currents within the wall, which are induced by the relative motion of the equatorial dipole field and the wall. This processes can be viewed as a skin effect or, equivalently, as the tearing apart of the dipole by the differential rotation of the wall, to which the field lines are anchored by high conductivity. (b) Increasing the magnetic permeability of the wall favors dynamo action by constraining the magnetic field lines in the fluid to be normal to the wall, thereby decoupling the fluid from any induction in the wall. (c) Decreasing the wall thickness limits the amplitude of the eddy currents, and is therefore favorable for dynamo action, provided that the wall is thinner than the skin depth. We explicitly demonstrate these effects of the wall properties on the dynamo field by deriving an effective boundary condition in the limit of vanishing wall thickness.Comment: accepted for publication in Physical Review

Trapping of nanoparticles with dielectrophoretic nano-probes.

Dielectrophoresis (DEP) is an electrokinetic force capable of attracting or repelling neutrally charged particles due to a non-uniform electric field [1, 2]. Positive dielectrophoresis attracts particles in the region of the highest electric field gradient; negative dielectrophoresis repels particles from the region of the highest electric field gradient. The dielectrophoretic force is directly proportional to the square of the electric field gradient, as well as the cube of the radius of the particles involved. As particles decrease in size, the gradient of the electric field must increase rapidly in order to capture or repel the particles. The intense electric field gradients were produced using fabricated silver gallium (Ag2Ga) nano-probes electrodes in conjunction with indium tin oxide (ITO) coated microscope cover slips, which served as the opposite electrode. The silver gallium nano-probes ranged from approximately 100-500 nm in diameter and were typically positioned less than 40 ?m above the ITO cover slips. Positive and negative dielectrophoretic forces were able to dominate the other electrokinetic forces acting on sub-micron particles, which were suspended in deionized water and aqueous potassium chloride, using the nano-probes and ITO cover slips as electrodes. Colloidal quantum dots of gold, as small as 5 nm in diameter, were captured using positive DEP forces, as were sub-micron fluorescent polystyrene particles. Negative DEP forces repelled sub-micron fluorescent polystyrene particles suspended in a low conductivity solution

Planning For Privately Owned Public Space In The Greater Toronto Area

Privately Owned Public Spaces (POPS) are public spaces which allow general access but remain under the ownership of the property owner. While popular around the world, they are becoming a visible entity in the landscapes of the Greater Toronto Area (GTA). The presence of POPS in downtown Toronto has been visible for several decades; however, cities located in the periphery of Toronto are beginning to adapt and create policies which allow for the creation of POPS. Although this integration is at its initial stage, with few spaces constructed and minimal policy preparation, there is a conscious intention to add this type of public space into the network of parkland and open space. Through interviews conducted with municipal planners, this research provides insight into the rationale and motivations of these cities to understand what is driving their pursuit of POPS. This research will contribute to the discussion on POPS from the context of an emerging market. As well, this paper offers recommendations which can assist municipalities preparing policies to regulate POPS

Coupling of sedimentation and liquid structure: influence on hard sphere nucleation

The discrepancy in nucleation rate densities between simulated and experimental hard spheres remains staggering and unexplained. Suggestively, more strongly sedimenting colloidal suspensions of hard spheres nucleate much faster than weakly sedimenting systems. In this work we consider firstly the effect of sedimentation on the structure of colloidal hard spheres, by tuning the density mismatch between solvent and colloidal particles. In particular we investigate the effect on the degree of five fold symmetry present. Secondly we study the size of density fluctuations in these experimental systems in comparison to simulations. The density fluctuations are measured by assigning each particle a local density, which is related to the number of particles within a distance of 3.25 particle diameters. The standard deviation of these local densities gives an indication of the fluctuations present in the system. Five fold symmetry is suppressed by a factor of two when sedimentation is induced in our system. Density fluctuations are also increased by a factor of two in experiments compared to simulations. The change in five fold symmetry makes a difference to the expected nucleation rates, but we demonstrate that it is ultimately too small to resolve the discrepancy between experiment and simulation, while the fluctuations are shown to be an artefact of 3d particle tracking.Comment: 8 page

Characterization of the CIP Protease System in the Growth and Development of Chlamydia trachomatis

Chlamydia is an obligate intracellular bacterium that differentiates between two distinct forms during its developmental cycle: elementary bodies (EBs) and reticulate bodies (RBs). The EB is the small, electron dense form that mediates host cell infection. Within the cell, the EB differentiates into the RB, which is the replicative form that develops within a host membrane derived vesicle, termed an inclusion. RBs replicate within this inclusion and eventually differentiate back into EBs. Upon accumulation of EBs at the end of the developmental cycle, the host cell lyses, releasing the EBs for infection of proximal cells. The EB and RB have distinct proteomic profiles, and, given the unique functional and morphological forms, the role of proteomic turnover through protein degradation is understudied in Chlamydia. We hypothesize that the CIP protease system plays an integral role in protein turnover by targeting specific proteins from one developmental form or the other for degradation. Chlamydia contains five genes encoding five CIP genes: clpX, clpC, two clpP paralogs, and clpB. Homotypic oligomerization of the CIP proteins was determined with bacterial two-hybrid assays and native-PAGE gels. Transcriptional analysis via RT-qPCR determined these genes are expressed mid-cycle. Antibiotics that non-specifically activated the ClpPs negatively affected chlamydial development. Additionally, inducible, poly-histidine tagged inactive CIP mutants were used to determine the effect of overexpression on Chlamydia. Taken together, these data suggest that i) the CIP system of Chlamydia functions comparably to other bacteria and ii) CIP proteins are important for chlamydial growth and development

Protecting Creativity: Why Moral Rights Should be Extended to Sound Recordings under New Zealand Copyright Law

Traditionally, moral rights have not extended to the creators of sound recordings under either common law or civil law systems. The somewhat outdated rationale of this exclusion of sound recordings from the ambit of moral rights protection was generally that sound recordings were merely mechanical reproductions of already existing musical works, and hence the recordings lacked sufficient creativity to make them worthy of moral rights protection. In 1996, the WIPO Performances and Phonograms Treaty sought to remedy this anomaly in copyright law by extending the moral rights of paternity and of integrity to performers whose performances are fixed in sound recordings.This paper argues that New Zealand should follow WIPO's lead and extend the moral rights provisions of the Copyright Act 1994 to sound recordings. The author argues that sound recordings are imbued with sufficient creativity to merit moral rights protection and that this protection should be granted not only to performers but to sound engineers and producers, who also contribute creatively to the recording. This paper examines how moral rights in relation to sound recordings might work in practice and what remedies should be available for breach of these rights. The author concludes that the extension of moral rights to sound recordings need not impact detrimentally on the music industry, as some commentators fear

A Qualitative Examination of Optimal Professional Traits of Physical Therapists. – An Exploratory Investigation

Physical therapists are constantly searching for aspects of their professional practice to improve, in order to enhance interactions with patients, eventually leading to a more successful practice (Resnek & Jensen, 2003). Although this is the case, limited research has been found which has examined optimal qualities of physical therapists from neither a qualitative perspective, nor based upon their location. Thus, the purpose of this study is to use a qualitative approach to describe optimal qualities necessary for a successful physical therapy practice. In addition, this study aims to determine if therapists practicing in a rural community describe different qualities than therapists practicing in a metropolitan area. The study found that effective communication skills, deeper relationships, vast knowledge and the ability to teach it, a motivating mentality and a calm demeanor are essential professional traits for physical therapists. There were no major differences in professional traits between rural and metropolitan areas