The Rate and Spatial Distribution of Novae in M31 as Determined by a 20 Year Survey

A long-term (1995-2016) survey for novae in the nearby Andromeda galaxy (M31) was conducted as part of the Research-Based Science Education initiative. During the course of the survey 180 nights of observation were completed at Kitt Peak, Arizona. A total of 262 novae were either discovered or confirmed, 40 of which have not been previously reported. Of these, 203 novae form a spatially complete sample detected by the KPNO/WIYN 0.9 m telescope within a 20 ′ × 20 ′ field centered on the nucleus of M31. An additional 50 novae are part of a spatially complete sample detected by the KPNO 4 m telescope within a larger 36 ′ × 36 ′ field. Consistent with previous studies, it is found that the spatial distribution of novae in both surveys follows the bulge light of M31 somewhat more closely than the overall background light of the galaxy. After correcting for the limiting magnitude and the spatial and temporal coverage of the surveys, a final nova rate in M31 is found to be R = 40 − 4 + 5 yr−1, which is considerably lower than recent estimates. When normalized to the K-band luminosity of M31, this value yields a luminosity-specific nova rate, ν K = 3.3 ± 0.4 yr − 1 [ 10 10 L ⊙ , K ] − 1 . By scaling the M31 nova rate using the relative infrared luminosities of M31 and our Galaxy, a nova rate of R G = 28 − 4 + 5 yr−1 is found for the Milky Way. © 2022. The Author(s). Published by the American Astronomical Society.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Quantification and Implications of Soil Losses from Commercial Sod Production

Commercial sod farms occupy about 1.62 × 103 km 2 of the landscape of the United States. Land managers generally consider sod farms on an equal footing with other, sustainable agricultural land uses. We measured soil losses associated with sod harvesting in farms in the northeastern United States. Sod harvest resulted in soil losses ranging from 74 to 114 Mg ha-1 yr-1 , considerably higher than the tolerable soil loss of 6.7 Mg ha-1 yr-1 . Soil losses were proportional to time under sod production, with soil removal rates of 0.833 cm yr-1 . We estimate that sod harvesting in the United States results in the net, permanent loss of 12.0 to 18.7 Tg of agriculturally productive soil from sod farms-and associated ecosystem services-every year. The soil losses reported here have important implications in terms of land use planning, transactions involving the purchase of development rights, and tax deductions for soil depletion. © Soil Science Society of America, 5585 Guilford Rd., Madison WI 53711 USA All rights reserved

Experience of using OWL ontologies for automated inference of routine pre-operative screening tests

We describe our experience of designing and implementing a knowledge-based pre-operative assessment decision support system. We developed the system using semantic web technology, including modular ontologies developed in the OWL Web Ontology Language, the OWL Java Application Programming Interface and an automated logic reasoner. Using ontologies at the core of the system’s architecture permits to efficiently manage a vast repository of pre-operative assessment domain knowledge, including classification of surgical procedures, classification of morbidities, and guidelines for routine pre-operative screening tests. Logical inference on the domain knowledge, according to individual patient’s medical context (medical history combined with planned surgical procedure) enables to generate personalised patients’ reports, consisting of a risk assessment and clinical recommendations, including relevant pre-operative screening tests