Robo-AO Discovery and Basic Characterization of Wide Multiple Star Systems in the Pleiades, Praesepe, and NGC 2264 Clusters

We identify and roughly characterize 66 candidate binary star systems in the Pleiades, Praesepe, and NGC 2264 star clusters based on robotic adaptive optics imaging data obtained using Robo-AO at the Palomar 60" telescope. Only $\sim$10% of our imaged pairs were previously known. We detect companions at red optical wavelengths having physical separations ranging from a few tens to a few thousand AU. A 3-sigma contrast curve generated for each final image provides upper limits to the brightness ratios for any undetected putative companions. The observations are sensitive to companions with maximum contrast $\sim$6$^m$ at larger separations. At smaller separations, the mean (best) raw contrast at 2 arcsec is 3.8$^m$ (6$^m$), at 1 arcsec is 3.0$^m$ (4.5$^m$), and at 0.5 arcsec is 1.9$^m$ (3$^m$). PSF subtraction can recover close to the full contrast in to the closer separations. For detected candidate binary pairs, we report separations, position angles, and relative magnitudes. Theoretical isochrones appropriate to the Pleiades and Praesepe clusters are then used to determine the corresponding binary mass ratios, which range from 0.2-0.9 in $q=m_2/m_1$. For our sample of roughly solar-mass (FGK type) stars in NGC 2264 and sub-solar-mass (K and early M-type) primaries in the Pleiades and Praesepe, the overall binary frequency is measured at $\sim$15.5% $\pm$ 2%. However, this value should be considered a lower limit to the true binary fraction within the specified separation and mass ratio ranges in these clusters, given that complex and uncertain corrections for sensitivity and completeness have not been applied.Comment: Accepted to A

High speed suburbanism: Developing transit infrastructures in a disconnected metropolis

The current interest in developing mobility alternatives such as high-speed rail and commuter rail systems in our auto dominated American regions poses new possibilities to reimagine our sprawling, disconnected, suburban landscapes. Since the patterns of development that automobile infrastructures have produced over the last century radically differ from the urbanisms that traditional rail systems once served, the integration of new transit systems into this contemporary context has potential for radical innovation. This thesis examines the impact of new modalities within our suburban environments and problematizes the monofunctionality of a ground plane fully dominated by the automobile. Through a multilayered fabric of mobility infrastructures, garden dwellings, retail strips, working units, and public outdoor spaces, this proposal condenses and reorganizes the suburban landscape into a field condition transit development with emerging nodes of connectivity to the ground, rail, and city landscape

Making a Case for Case-Based Teaching in Data Literacy

Building on a study conducted by the authors, this article provides strategies for teaching data literacy and outlines the case-based teaching method as an effective way of developing data-literate teachers

Asking, Learning, Seeking Out : An Exploration of Data Literacy for Teaching

The current study explored preservice and inservice teachers’ perspectives on data literacy for teaching. Semi-structured interviews were employed with 12 teacher candidates in elementary and special education. The findings revealed participants’ misconceptions regarding formative and summative data; their understanding of the value of formative data; perceptions of challenges related to data literacy for teaching including time, making sense of data, and reliability and validity; and candidates’ preferences for authentic data literacy instruction

PACAP-38 Signaling in \u3ci\u3eTetrahymena thermophila\u3c/i\u3e Involves NO and cGMP

Chemorepellents are signaling molecules, which have been shown to be important for mammalian neuronal development, and are presumed to have a role in protozoan defense. Tetrahymena thermophila represent a good model system in which to study repellents because of their ease of use in biochemical, behavioral, electrophysiological, and genetic analyses. In this study, we have used Tetrahymena as a model in which to study the chemorepellent, PACAP. Using behavioral and biochemical (EIA) assays, we have found that the NO/cGMP pathway plays an important role in PACAP signaling. An increase in intracellular calcium is also critical for PACAP avoidance, which appears to be mediated through a pertussis toxin-sensitive G-protein