Vibration of skewed cantilever plates and helicoidal shells

Theoretical vibration frequencies and mode shapes are obtained for skewed plates and helicoidal shells with a cantilever boundary. Using Hamilton's law of varying action, a power series solution is developed to obtain converged numerical results for the five lowest frequencies. Effects of geometrical variables such as aspect ratio, sweep angle and shell radius to thickness ratio are investigated. Accuracy of the solution method is substantiated by comparison with existing skewed plate spherical cap, and conical shell results

Fast and deep deformation approximations

Character rigs are procedural systems that compute the shape of an animated character for a given pose. They can be highly complex and must account for bulges, wrinkles, and other aspects of a character's appearance. When comparing film-quality character rigs with those designed for real-time applications, there is typically a substantial and readily apparent difference in the quality of the mesh deformations. Real-time rigs are limited by a computational budget and often trade realism for performance. Rigs for film do not have this same limitation, and character riggers can make the rig as complicated as necessary to achieve realistic deformations. However, increasing the rig complexity slows rig evaluation, and the animators working with it can become less efficient and may experience frustration. In this paper, we present a method to reduce the time required to compute mesh deformations for film-quality rigs, allowing better interactivity during animation authoring and use in real-time games and applications. Our approach learns the deformations from an existing rig by splitting the mesh deformation into linear and nonlinear portions. The linear deformations are computed directly from the transformations of the rig's underlying skeleton. We use deep learning methods to approximate the remaining nonlinear portion. In the examples we show from production rigs used to animate lead characters, our approach reduces the computational time spent on evaluating deformations by a factor of 5×-10×. This significant savings allows us to run the complex, film-quality rigs in real-time even when using a CPU-only implementation on a mobile device

A Search for Biomolecules in Sagittarius B2 (LMH) with the ATCA

We have used the Australia Telescope Compact Array to conduct a search for the simplest amino acid, glycine (conformers I and II), and the simple chiral molecule propylene oxide at 3-mm in the Sgr B2 LMH. We searched 15 portions of spectrum between 85 and 91 GHz, each of 64 MHz bandwidth, and detected 58 emission features and 21 absorption features, giving a line density of 75 emission lines and 25 absorption lines per GHz stronger than the 5 sigma level of 110 mJy. Of these, 19 are transitions previously detected in the interstellar medium, and we have made tentative assignments of a further 23 features to molecular transitions. However, as many of these involve molecules not previously detected in the ISM, these assignments cannot be regarded with confidence. Given the median line width of 6.5 km/s in Sgr B2 LMH, we find that the spectra have reached a level where there is line confusion, with about 1/5 of the band being covered with lines. Although we did not confidently detect either glycine or propylene oxide, we can set 3 sigma upper limits for most transitions searched. We also show that if glycine is present in the Sgr B2 LMH at the level of N = 4 x 10^{14} cm^{-2} found by Kuan et al. (2003) in their reported detection of glycine, it should have been easily detected with the ATCA synthesized beam size of 17.0 x 3.4 arcsec^{2}, if it were confined to the scale of the LMH continuum source (< 5 arcsec). This thus puts a strong upper limit on any small-scale glycine emission in Sgr B2, for both of conformers I and II.Comment: 12 pages, 2 figures, 5 tables, accepted by MNRA

Poincaré maps define topography of Vlasov distribution functions consistent with stochastic dynamics

In a recent paper [A. D. Bailey et al., Phys. Rev. Lett. 34, 3124 (1993)], the authors presented direct planar laser induced fluorescence measurements of the oscillatory ion fluid velocity field in the presence of a large amplitude drift-Alfven wave. Surprisingly, the measured speeds were an order of magnitude lower than predicted by standard fluid theory, yet the flow pattern was consistent with the fluid theory. A new model, based on the connection between stochasticity and bulk behavior, is presented which gives insights into the cause of this behavior. It is shown that when particle motion is stochastic, invariant sets of a 'Poincaré map' define a flat-topped particle distribution function consistent with both the electromagnetic field driving the Vlasov equation and the fine-scale single particle dynamics. The approach is described for the general case and explored for a slab model of the observed drift wave

Characterization of a spheromak plasma gun: The effect of refractory electrode coatings

In order to investigate the proposition that high-Z impurities are responsible for the anomalously short lifetime of the Caltech spheromak, the center electrode of the spheromak plasma gun has been coated with a variety of metals (bare steel, copper, nickel, chromium, rhodium, and tungsten). Visible light (230–890 nm) emitted directly from the plasma in the gun breech was monitored for each of the coated electrodes. Plasma density and temperature and spheromak lifetime were compared for each electrode. Results indicate little difference in gun performance or macroscopic plasma parameters. The chromium and tungsten electrodes performed marginally better in that a previously reported helicity injection effect [Phys. Rev. Lett. 64, 2144 (1990)] is only observed in discharges using these electrode coatings. There are subtle differences in the detailed line emission spectra from the different electrodes, but the spectra are remarkably similar. The fact that (1) contrary to expectations, attempts to reduce high-Z impurities had only marginal effect on the spheromak lifetime coupled with (2) an estimate of Zeff<2 based on a 0-D model suggests that it is not impurities but some other mechanism that limits the lifetime of small, cold spheromaks. We will discuss the general characteristics of the spheromak gun as well as effects due to the coatings

Does kinesiology taping of the ankles affect proprioceptive control in professional football (soccer) players?

Abstract Objective To determine whether the bilateral application of kinesiology tape (KT) to professional footballers' ankles can improve their lower limb proprioception. Design A single blind randomised crossover study. Participants were randomly assigned to complete a proprioception test in either a taped or not taped condition first. Following a wash out period, participants were then re-tested in the alternate condition. Setting A UK Championship League Football Club, mid-season. Participants Twenty male professional football players over the age of 18, currently match fit with no injuries. Outcome measure Proprioception was assessed by participants undertaking the moving target program on the balance module attached to a Kin-Com 125AP isokinetic dynamometer. A paired sample two tailed t-test was used to assess whether there was a significant difference between the participants test scores in the not taped and taped conditions. Results The bilateral application of KT to professional footballers' ankles did not bring about a significant change in participants' scores when tested with a fine movement and balance control test. Percentage accuracy score mean difference 4.2 (p = 0.285). Conclusion The results of this study do not support the use of KT when applied to the ankles of healthy footballers as a method of improving proprioception

Oligonucleotide sequences forming short self-complimentary hairpins can expedite the down-regulation of Coprinopsis cinerea genes

Gene silencing in fungi is often induced by dsRNA hairpin forming constructs the preparation of which can require multiple cloning steps. To simplify gene silencing in the filamentous fungi we have evaluated a high throughput cloning method for target sequences using the homobasidiomycete Coprinopsis cinerea, the GFP reporter and a commercially available vector system. The pSUPER RNAi System™, which was developed for mammalian experiments, exploits the human H1 Polymerase III (Pol III) RNA gene promoter and expedites cloning/expression of specific user-defined oligonucleotide sequences to form short self-complimentary hairpins. Transformation of C. cinerea with pSUPER constructs harboring specific oligonucleotides (19 nt stem length) enabled recovery of transformants with reduced transcripts of the GFP transgene, that were less fluorescent in protein assays and microscopic phenotypes. This technological advance should expedite functional genomic studies in C. cinerea and has wider potential for utility in other homobasidiomycete and filamentous fungi

Pollination services in the UK: how important are honeybees?

Pollination services are known to provide substantial benefits to human populations and agriculture in particular. Although many species are known to provide pollination services, honeybees (Apis mellifera) are often assumed to provide the majority of these services to agriculture. Using data from a range of secondary sources, this study assesses the importance of insect pollinated crops at regional and national scales and investigates the capacity of honeybees to provide optimal pollination services to UK agriculture. The findings indicate that insect pollinated crops have become increasingly important in UK crop agriculture and, as of 2007, accounted for 20% of UK cropland and 19% of total farmgate crop value. Analysis of honeybee hive numbers indicates that current UK populations are only capable of supplying 34% of pollination service demands even under favourable assumptions, falling from 70% in 1984. In spite of this decline, insect pollinated crop yields have risen by an average of 54% since 1984, casting doubt on long held beliefs that honeybees provide the majority of pollination services. Future land use and crop production patterns may further increase the role of pollination services to UK agriculture, highlighting the importance of measures aimed at maintaining both wild and managed species

Climate change at the ecosystem scale: a 50-year record in New Hampshire

Observing the full range of climate change impacts at the local scale is difficult. Predicted rates of change are often small relative to interannual variability, and few locations have sufficiently comprehensive long-term records of environmental variables to enable researchers to observe the fine-scale patterns that may be important to understanding the influence of climate change on biological systems at the taxon, community, and ecosystem levels. We examined a 50-year meteorological and hydrological record from the Hubbard Brook Experimental Forest (HBEF) in New Hampshire, an intensively monitored Long-Term Ecological Research site. Of the examined climate metrics, trends in temperature were the most significant (ranging from 0.7 to 1.3 °C increase over 40–50 year records at 4 temperature stations), while analysis of precipitation and hydrologic data yielded mixed results. Regional records show generally similar trends over the same time period, though longer-term (70–102 year) trends are less dramatic. Taken together, the results from HBEF and the regional records indicate that the climate has warmed detectably over 50 years, with important consequences for hydrological processes. Understanding effects on ecosystems will require a diversity of metrics and concurrent ecological observations at a range of sites, as well as a recognition that ecosystems have existed in a directionally changing climate for decades, and are not necessarily in equilibrium with the current climate

Multimodality, visual methods and lived experience

View from the Top from Prof Paula Reavey Paula Reavey is Professor of Psychology and Mental Health at London South Bank University. This interview took place at the Qualitative Methods in Psychology (QMiP) and History & Philosophy of Psychology (HPP) joint 2019 conference at Cardiff Metropolitan University where Paula led a workshop on visual methods and delivered a keynote speech. Best known for her pathbreaking work on visual methods and multimodality (Reavey, 2011), she has also distinguished herself with her innovative interdisciplinary work in the field of mental health, space and embodiment. Susanne Langer (Senior Lecturer in Psychology, MMU) and Deborah Bailey-Rodriguez (Lecturer in Psychology, Middlesex University), who are both associate editors of the QMiP Bulletin, asked the questions