Octahedron-based Projections as Intermediate Representations for Computer Imaging: TOAST, TEA, and More

This paper defines and discusses a set of rectangular all-sky projections that have no singular points, notably the Tesselated Octahedral Adaptive Spherical Transformation (or TOAST) developed initially for the WorldWide Telescope. These have proven to be useful as intermediate representations for imaging data where the application transforms dynamically from a standardized internal format to a specific format (projection, scaling, orientation, etc.) requested by the user. TOAST is strongly related to the Hierarchical Triangular Mesh pixelization and is particularly well adapted to situations where one wishes to traverse a hierarchy of images increasing in resolution. Because it can be recursively computed using a very simple algorithm it is particularly adaptable to use with graphical processing units

A New Hybrid Framework to Efficiently Model Lines of Sight to Gravitational Lenses

In strong gravitational lens systems, the light bending is usually dominated by one main galaxy, but may be affected by other mass along the line of sight (LOS). Shear and convergence can be used to approximate the contributions from less significant perturbers (e.g. those that are projected far from the lens or have a small mass), but higher order effects need to be included for objects that are closer or more massive. We develop a framework for multiplane lensing that can handle an arbitrary combination of tidal planes treated with shear and convergence and planes treated exactly (i.e., including higher order terms). This framework addresses all of the traditional lensing observables including image positions, fluxes, and time delays to facilitate lens modelling that includes the non-linear effects due to mass along the LOS. It balances accuracy (accounting for higher-order terms when necessary) with efficiency (compressing all other LOS effects into a set of matrices that can be calculated up front and cached for lens modelling). We identify a generalized multiplane mass sheet degeneracy, in which the effective shear and convergence are sums over the lensing planes with specific, redshift-dependent weighting factors.Comment: 13 pages, 2 figure

WorldWide Telescope in Research and Education

The WorldWide Telescope computer program, released to researchers and the public as a free resource in 2008 by Microsoft Research, has changed the way the ever-growing Universe of online astronomical data is viewed and understood. The WWT program can be thought of as a scriptable, interactive, richly visual browser of the multi-wavelength Sky as we see it from Earth, and of the Universe as we would travel within it. In its web API format, WWT is being used as a service to display professional research data. In its desktop format, WWT works in concert (thanks to SAMP and other IVOA standards) with more traditional research applications such as ds9, Aladin and TOPCAT. The WWT Ambassadors Program (founded in 2009) recruits and trains astrophysically-literate volunteers (including retirees) who use WWT as a teaching tool in online, classroom, and informal educational settings. Early quantitative studies of WWTA indicate that student experiences with WWT enhance science learning dramatically. Thanks to the wealth of data it can access, and the growing number of services to which it connects, WWT is now a key linking technology in the Seamless Astronomy environment we seek to offer researchers, teachers, and students alike.Comment: 4 pages, 2 figures, describes software available at worldwidetelescope.or

Past approaches and future directions for targeting tumor hypoxia in squamous cell carcinomas of the head and neck

AbstractRecurrent squamous cell carcinoma of the head and neck (SCCHN) carries a poor prognosis. Tumor hypoxia (TH) has been implicated as one of many factors contributing to SCCHN recurrence. TH leads to radiation resistance by reversing radiation-induced DNA damage. Effective strategies to overcome TH may improve outcomes in patients with SCCHN. We searched the English literature on PubMed and reviewed the reference sections of key articles related to TH (publications spanning from the early 1900s to the present). We summarized the underlying theory of TH in SCCHN, methods for quantifying it, and the numerous therapies developed to modulate it. We included articles that set the foundation of TH as a theory and the most relevant articles published within the last 15 years related to TH quantification and therapeutic targeting. Despite extensive research, targeting TH in SCCHN has not become a part of routine clinical practice in North America, and we analyze the pitfalls in hypoxia research that have led to this failure. We propose that future studies should test a combined approach of targeting the immune system in addition to cellular pathways rendered aberrant in TH and should include development of novel surrogate markers of TH and/or TH imaging

SunSat Design Competition 2015-2016 Second Place Winner – Team Pathway to Power : Wireless Power Transfer

Solar Power Satellites (SPS) using Wireless Power Transfer (WPT) to beam renewable energy to consumers on earth face three grand challenges: moving parts, heat dissipation, and radio interference. Solutions to each of these “show stoppers” are presented here. Further, a progressively more-complex pathway is described which starts where we are now and leads step-wise to implementation of large-scale Space Solar Power (SSP). The first two grand challenges are addressed by a novel SPS design based on a thin-walled cylinder configuration of solar panels. The remaining challenge is tackled through a newly-discovered antenna configuration which allows dramatic reduction in radio/telecom interference from so-called “sidelobes.” The cost of this SPS (called the “tin can” for its resemblance to a soup tin with the “lid” antenna canted up at an angle) is made affordable through the use of raw materials already present in space. The techniques known as In-Situ Resource Utilization (ISRU, or “living off the land”) provide for the refinement of minerals (powdered rock or “regolith”) from the moon or from asteroids into the pure metals and semiconductors needed to build the tin can SPS. All these factors are brought together as the ultimate goal of a progression of value-added solutions leading to commercial feasibility of SSP. Click here to see this team video: Pathway to Power Faculty Advisor: Peter Schubert, Director, Richard G. Lugar Center for Renewable Energy; Professor of Electrical and Computer Engineering, Indiana University-Purdue University, Indianapolis, Indian

A Frequentist Approach to Computer Model Calibration

This paper considers the computer model calibration problem and provides a general frequentist solution. Under the proposed framework, the data model is semi-parametric with a nonparametric discrepancy function which accounts for any discrepancy between the physical reality and the computer model. In an attempt to solve a fundamentally important (but often ignored) identifiability issue between the computer model parameters and the discrepancy function, this paper proposes a new and identifiable parametrization of the calibration problem. It also develops a two-step procedure for estimating all the relevant quantities under the new parameterization. This estimation procedure is shown to enjoy excellent rates of convergence and can be straightforwardly implemented with existing software. For uncertainty quantification, bootstrapping is adopted to construct confidence regions for the quantities of interest. The practical performance of the proposed methodology is illustrated through simulation examples and an application to a computational fluid dynamics model.Comment: 21 pages, 2 figure

WorldWide Telescope in Research and Education

The WorldWide Telescope computer program, released to researchers and the public as a free resource in 2008 by Microsoft Research, has changed the way the ever-growing Universe of online astronomical data is viewed and understood. The WWT program can be thought of as a scriptable, interactive, richly visual browser of the multi-wavelength Sky as we see it from Earth, and of the Universe as we would travel within it. In its web API format, WWT is being used as a service to display professional research data. In its desktop format, WWT works in concert (thanks to SAMP and other IVOA standards) with more traditional research applications such as ds9, Aladin and TOPCAT. The WWT Ambassadors Program (founded in 2009) recruits and trains astrophysically-literate volunteers (including retirees) who use WWT as a teaching tool in online, classroom, and informal educational settings. Early quantitative studies of WWTA indicate that student experiences with WWT enhance science learning dramatically. Thanks to the wealth of data it can access, and the growing number of services to which it connects, WWT is now a key linking technology in the Seamless Astronomy environment we seek to offer researchers, teachers, and students alike.Astronom

Editorial: Grounds for Re-wor(l)ding

This is a co-authored Editorial for a special issue of Studies in Theatre and Performance journal titled open-call+response:This editorial elaborates on the processes and practices of Open Call and its iteration as a print and online issue of Studies in Theatre and Performance. It offers a collaborative framing of the issue that includes the voices of its editors and peer reviewers, and suggests some possible pathways through the texts and artworks that comprise this special issue, which is titled open-call+response