Interaction and Expressivity in Video Games: Harnessing the Rhetoric of Film

The film-maker uses the camera and editing creatively, not simply to present the action of the film but also to set up a particular relation between the action and the viewer. In 3D video games with action controlled by the player, the pseudo camera is usually less creatively controlled and has less effect on the player’s appreciation of and engagement with the game. This paper discusses methods of controlling games by easy and intuitive interfaces and use of an automated virtual camera to increase the appeal of games for users

Design principles for metamorphic block copolymer assemblies

Certain block copolymer assemblies in selective solvents undergo dynamic morphology transitions (metamorphism) on varying the solution temperature. Despite the great application potential, there is a lack of fundamental understanding of the relationship between copolymer composition and the thermally-induced metamorphic behavior. Herein this relationship is studied by applying Scheutjens-Fleer Self-Consistent Field (SF-SCF) theory to develop fundamental design principles for thermoresponsive diblock copolymers exhibiting metamorphic behavior. It is found that metamorphism is caused by variation in the degree of stretching of the lyophobic blocks in response to changes in solvency. An optimal lyophobic/lyophilic block length ratio interval 3.5 ≲ fB ≲ 5.5 is identified. Such a fB window allows switching between spheres, cylinders and vesicles as preferred morphologies, with relatively small changes in the lyophobic block solvency. The transition from spheres to cylinders and from cylinders to bilayers can be controlled by varying fB, the overall degree of polymerization of the diblock copolymer, and by choosing an appropriate lyophilic block. Empirical relationships are provided to establish a connection between the SCF–SCF predictions and experimental observations

The laboratory culture and development of Helicoverpa Armigera

Techniques for the laboratory rearing of Helicoverpa armigera, an important pest of food crops in the Old World tropics, are described. Methods for rearing all stages of the insect are given, including recepies for artificial diets and recommendations for the recognition and control of disease. The effects of various environmental factors on development in the laboratory are described

Exploring the Upper Size Limit for Sterically Stabilized Diblock Copolymer Nanoparticles Prepared by Polymerization-Induced Self-Assembly in Non-Polar Media

Reversible addition–fragmentation chain transfer (RAFT) dispersion polymerization of benzyl methacrylate is used to prepare a series of well-defined poly(stearyl methacrylate)–poly(benzyl methacrylate) (PSMA–PBzMA) diblock copolymer nanoparticles in mineral oil at 90 °C. A relatively long PSMA54 precursor acts as a steric stabilizer block and also ensures that only kinetically trapped spheres are obtained, regardless of the target degree of polymerization (DP) for the core-forming PBzMA block. This polymerization-induced self-assembly (PISA) formulation provides good control over the particle size distribution over a wide size range (24–459 nm diameter). 1H NMR spectroscopy studies confirm that high monomer conversions (≥96%) are obtained for all PISA syntheses while transmission electron microscopy and dynamic light scattering analyses show well-defined spheres with a power-law relationship between the target PBzMA DP and the mean particle diameter. Gel permeation chromatography studies indicate a gradual loss of control over the molecular weight distribution as higher DPs are targeted, but well-defined morphologies and narrow particle size distributions can be obtained for PBzMA DPs up to 3500, which corresponds to an upper particle size limit of 459 nm. Thus, these are among the largest well-defined spheres with reasonably narrow size distributions (standard deviation ≤20%) produced by any PISA formulation. Such large spheres serve as model sterically stabilized particles for analytical centrifugation studies

Evidence of ratchet effect in nanowires of a conducting polymer

Ratchet effect, observed in many systems starting from living organism to artificially designed device, is a manifestation of motion in asymmetric potential. Here we report results of a conductivity study of Polypyrrole nanowires, which have been prepared by a simple method to generate a variation of doping concentration along the length. This variation gives rise to an asymmetric potential profile that hinders the symmetry of the hopping process of charges and hence the value of measured resistance of these nanowires become sensitive to the direction of current flow. The asymmetry in resistance was found to increase with decreasing nanowire diameter and increasing temperature. The observed phenomena could be explained with the assumption that the spatial extension of localized state involved in hopping process reduces as the doping concentration reduces along the length of the nanowires.Comment: Revtex, two column, 4 pages, 10 figure

Synthesis of well-defined epoxy-functional spherical nanoparticles by RAFT aqueous emulsion polymerization

The environmentally-friendly synthesis of epoxy-functional spherical nanoparticles has been achieved using polymerization-induced self-assembly (PISA) in aqueous solution. Firstly, a non-ionic hydrophilic stabilizer block, poly(glycerol monomethacrylate) (PGMA), was prepared by reversible addition–fragmentation chain transfer (RAFT) solution polymerization in ethanol. This water-soluble precursor was subsequently chain-extended via RAFT aqueous emulsion polymerization of glycidyl methacrylate (GlyMA) at 50 °C and neutral pH to ensure maximum retention of the epoxy functionality. PISA leads to the formation of well-defined PGMA-PGlyMA spherical diblock copolymer nanoparticles at up to 35% w/w solids and 1H NMR spectroscopy studies indicated that virtually all of the epoxy groups survive such relatively mild conditions. DMF GPC studies confirmed that relatively low dispersities (Mw/Mn </p

Stimulus-responsive block copolymer nano-objects and hydrogels via dynamic covalent chemistry

Herein we demonstrate that dynamic covalent chemistry can be used to induce reversible morphological transitions in block copolymer nano-objects and hydrogels. Poly(glycerol monomethacrylate)–poly(2- hydroxypropyl methacrylate) (PGMA–PHPMA) diblock copolymer nano-objects (vesicles or worms) were prepared via polymerization-induced self-assembly. Addition of 4-carboxyphenylboronic acid (CPBA) leads to the formation of phenylboronate ester bonds with the 1,2-diol pendent groups on the hydrophilic PGMA stabilizer chains; such binding causes a subtle reduction in the packing parameter, which in turn induces either vesicle-to-worm or worm-to-sphere transitions. Moreover, CPBA binding is pH-dependent, so reversible transitions can be achieved by switching the solution pH, with relatively high copolymer concentrations leading to associated (de)gelation. This distinguishes these new physical hydrogels from the covalently cross-linked gels prepared using dynamic covalent chemistry reported in the literature

Comparative status of insecticide resistance in the Helicoverpa and Heliothis species (Lepidoptera: Noctuidae) of south India

Helicoverpa armigera (Hübner), H. assulta Guenée and Heliothis peltigera (Denis & Schiffermüller) were collected as mixed populations from safflower and the wild host Datura metel, from Patancheru, Andhra Pradesh, India, in 1992 and 1993, and their toxicological responses to insecticides determined. Both Helicoverpa armigera strains were highly resistant to cypermethrin, fenvalerate, endosulfan and quinalphos insecticides, based on resistance ratios relative to laboratory reared susceptible strains. There was no evidence of resistance development in H. assulta and Heliothis peltigera to the same chemicals. Light trap data collected from 1974 to 1987 showed that Helicoverpa armigera was at least 100 × more abundant than the other two species over most of the cropping season. Peak catches of H. assulta and Heliothis peltigera were confined to defined times in the season, corresponding with the flowering and fruiting periods of their respective host plants; August-October for Helicoverpa assulta and November-December for Heliothis peltigera. Helicoverpa armigera on the other hand, because of its high polyphagy on commercial and wild hosts, was abundant between August and April. Resistance has not developed in H. assulta and Heliothis peltigera in southern India, probably because of their restricted host range, limiting exposure to insecticides

A worm gel-based 3D model to elucidate the paracrine interaction between multiple myeloma and mesenchymal stem cells

Multiple myeloma (MM) is a malignancy of terminally-differentiated plasma cells that develops mainly inside the bone marrow (BM) microenvironment. It is well known that autocrine and paracrine signals are responsible for the progression of this disease but the precise mechanism and contributions from single cell remain largely unknown. Mesenchymal stem cells (MSC) are an important cellular component of the BM: they support MM growth by increasing its survival and chemo-resistance, but little is known about the paracrine signaling pathways. Three-dimensional (3D) models of MM-MSC paracrine interactions are much more biologically-relevant than simple 2D models and are considered essential for detailed studies of MM pathogenesis. Herein we present a novel 3D co-culture model designed to mimic the paracrine interaction between MSC and MM cells. MSC were embedded within a previously characterized thermoresponsive block copolymer worm gel that can induce stasis in human pluripotent stem cells (hPSC) and then co-cultured with MM cells. Transcriptional phenotyping of co-cultured cells indicated the dysregulation of genes that code for known disease-relevant factors, and also revealed IL-6 and IL-10 as upstream regulators. Importantly, we have identified a synergistic paracrine signaling pathway between IL-6 and IL-10 that plays a critical role in sustaining MM cell proliferation. Our findings indicate that this 3D co-culture system is a useful model to investigate the paracrine interaction between MM cells and the BM microenvironment in vitro. This approach has revealed a new mechanism that promotes the proliferation of MM cells and suggested a new therapeutic target

Diapause in Two Tachinid (Diptera: Tachinidae) Parasitoids of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in Southern India

Two larval-pupal tachinid parasitoids; Goniophthalmus halli (Mesnil) and Senometopia (Eucarcelia) illota (Curran) were recorded from the pupae of Helicoverpa armigera (Hubner) on pigeonpea crop in Andhra Pradesh, India, between 1974 and 1996. Both the parasitoids enter in diapause following the signals received from their host and maintain close proximity in their development in nondiapausing and diapausing H. armigera populations. It is suggested that parasitoid diapause is induced by the physiological changes in late larval or pupal stage of the host and was observed in seasons when host diapause occurred and followed synchrony in terms of emergence for both the host and parasitoids. This is the first report of diapause in tachinid parasitoids from the southern region of Indian sub-continent