3,243 research outputs found
Textâanalysis reveals taxonomic and geographic disparities in animal pollination literature
Ecological systematic reviews and metaâanalyses have significantly increased our understanding of global biodiversity decline. However, for some ecological groups, incomplete and biased datasets have hindered our ability to construct robust, predictive models. One such group consists of the animal pollinators. Approximately 88% of wild plant species are thought to be pollinated by animals, with an estimated annual value of $230â410âbillion dollars. Here we apply textâanalysis to quantify the taxonomic and geographical distribution of the animal pollinator literature, both temporally and spatially. We show that the publication of pollinator literature increased rapidly in the 1980s and 1990s. Taxonomically, we show that the distribution of pollinator literature is concentrated in the honey bees (Apis) and bumble bees (Bombus), and geographically in North America and Europe. At least 25% of pollinationârelated abstracts mention a species of honey bee and at least 20% a species of bumble bee, and approximately 46% of abstracts are focussed on either North America (32%) or Europe (14%). Although these results indicate strong taxonomic and geographic biases in the pollinator literature, a large number of studies outside North America and Europe do exist. We then discuss how textâanalysis could be used to shorten the literature search for ecological systematic reviews and metaâanalyses, and to address more applied questions related to pollinator biodiversity, such as the identification of likely interacting plantâpollinator pairs and the number of pollinating species
Motion Sickness Treatment Apparatus and Method
Methods and apparatus are disclosed for treating motion sickness. In a preferred embodiment a method of the invention comprises operating eyewear having shutter lenses to open said shutter lenses at a selected operating frequency ranging from within about 3 Hz to about 50 Hz. The shutter lenses are opened for a short duration at the selected operating frequency wherein the duration is selected to prevent retinal slip. The shutter lenses may be operated at a relatively slow frequency of about 4 Hz when the user is in passive activity such as riding in a boat or car or in limited motion situations in a spacecraft. The shutter lenses may be operated at faster frequencies related to motion of the user's head when the user is active
A large area detector for neutrons between 2 and 100 MeV
A neutron detector sensitive from 2 to 100 MeV is described. The detector is designed for high altitude balloon flight to measure the flux, energy and direction of albedo neutrons from the earth and to search for solar neutrons. A neutron scatter from a proton is required in each of two liquid scintillator tanks spaced 1 meter apart. The energy of the recoil proton in the first tank is obtained from pulse height analysis of the scintillator output. The energy of the recoil neutron is obtained from its time of flight between the tanks. The detector has been calibrated with 15.3 MeV neutrons and mu mesons. The minimum detectable flux is 10(-4) neutron/sq cm/sec at a counting rate of one per minute; the energy resolution is 12% at 15 MeV and 30% at 100 MeV. The angle between the incoming neutron and the recoil neutron is measured to + or - 10 deg
An Approximate Message Passing Algorithm for Rapid Parameter-Free Compressed Sensing MRI
For certain sensing matrices, the Approximate Message Passing (AMP) algorithm
efficiently reconstructs undersampled signals. However, in Magnetic Resonance
Imaging (MRI), where Fourier coefficients of a natural image are sampled with
variable density, AMP encounters convergence problems. In response we present
an algorithm based on Orthogonal AMP constructed specifically for variable
density partial Fourier sensing matrices. For the first time in this setting a
state evolution has been observed. A practical advantage of state evolution is
that Stein's Unbiased Risk Estimate (SURE) can be effectively implemented,
yielding an algorithm with no free parameters. We empirically evaluate the
effectiveness of the parameter-free algorithm on simulated data and find that
it converges over 5x faster and to a lower mean-squared error solution than
Fast Iterative Shrinkage-Thresholding (FISTA).Comment: 5 pages, 5 figures, IEEE International Conference on Image Processing
(ICIP) 202
A Reusable, Extensible Infrastructure for Augmented Field Trips
This paper describes a reusable pervasive information infrastructure developed as part of the Equator IRC, designed to allow the construction of literacy based eLearning activities on top of material created as part of a more traditional visitors system. The architecture of the system is described along with details of the creation of the curated material and the subsequent adaption of the system by local primary school teachers to create a literacy experiences. Results of the first trials of the system are presented with conclusions drawn and discussion of future directions
UbiComp in Opportunity Spaces: Challenges for Participatory Design
The rise of ubiquitous computing (UbiComp), where pervasive, wireless and disappearing technologies offer hitherto unavailable means of supporting activity, increasingly opens up âopportunity spacesâ. These are spaces where there is no urgent problem to be solved, but much potential to augment and enhance practice in new ways. Based on our experience of co-designing novel user experiences for visitors to an English country estate, we discuss challenges for PD in such an opportunity space. Key amongst these are how to build a working relationship of value when there are no urgent requirements; how to understand and scope the space of opportunities; and how to leave users with new resources of value to them
Approximate Message Passing with a Colored Aliasing Model for Variable Density Fourier Sampled Images
The Approximate Message Passing (AMP) algorithm efficiently reconstructs
signals which have been sampled with large i.i.d. sub-Gaussian sensing
matrices. Central to AMP is its "state evolution", which guarantees that the
difference between the current estimate and ground truth (the "aliasing") at
every iteration obeys a Gaussian distribution that can be fully characterized
by a scalar. However, when Fourier coefficients of a signal with non-uniform
spectral density are sampled, such as in Magnetic Resonance Imaging (MRI), the
aliasing is intrinsically colored, AMP's scalar state evolution is no longer
accurate and the algorithm encounters convergence problems. In response, we
propose the Variable Density Approximate Message Passing (VDAMP) algorithm,
which uses the wavelet domain to model the colored aliasing. We present
empirical evidence that VDAMP obeys a "colored state evolution", where the
aliasing obeys a Gaussian distribution that can be fully characterized with one
scalar per wavelet subband. A benefit of state evolution is that Stein's
Unbiased Risk Estimate (SURE) can be effectively implemented, yielding an
algorithm with subband-dependent thresholding that has no free parameters. We
empirically evaluate the effectiveness of VDAMP on three variations of Fast
Iterative Shrinkage-Thresholding (FISTA) and find that it converges in around
10 times fewer iterations on average than the next-fastest method, and to a
comparable mean-squared-error.Comment: 13 pages, 7 figures, 3 tables. arXiv admin note: text overlap with
arXiv:1911.0123
The Literacy Fieldtrip: Using UbiComp to Support Children's Creative Writing
Fieldtrips, traditionally associated with science, history and geography teaching, have long been used to support childrenâs learning by allowing them to engage with environments first-hand. Recently, ubiquitous computing (UbiComp) has been used to enhance fieldtrips in these educational areas by augmenting environments with a range of instruments, devices and sensors. However, the sorts of interaction design that UbiComp makes possible have the potential not just to enhance the value of educational techniques in known application areas, but also to expand the application of those techniques into new areas of curriculum. We report on a UbiComp-supported fieldtrip to support creative writing, associated with the learning of literacy skills. We discuss how the fieldtrip, designed and run in the grounds of a historic English country house with Year 5 UK schoolchildren, engendered interactions which changed both the processes and products of creative writing, with benefits for both teachers and children
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