6609 research outputs found
Sort by
VLTI/GRAVITY Observations and Characterization of the Brown Dwarf Companion HD 72946 B
Get PDFTension remains between the observed and modeled properties of substellar objects, but objects in binary orbits, with known dynamical masses, can provide a way forward. HD 72946 B is a recently imaged brown dwarf companion to a nearby, solar-type star. We achieve ∼100 μas relative astrometry of HD 72946 B in the K band using VLTI/GRAVITY, unprecedented for a benchmark brown dwarf. We fit an ensemble of measurements of the orbit using orbitize! and derive a strong dynamical mass constraint M B = 69.5 ± 0.5 M Jup assuming a strong prior on the host star mass M A = 0.97 ± 0.01 M ⊙ from an updated stellar analysis. We fit the spectrum of the companion to a grid of self-consistent BT-Settl-CIFIST model atmospheres, and perform atmospheric retrievals using petitRADTRANS. A dynamical mass prior only marginally influences the sampled distribution of effective temperature, but has a large influence on the surface gravity and radius, as expected. The dynamical mass alone does not strongly influence retrieved pressure-temperature or cloud parameters within our current retrieval setup. Independently of the cloud prescription and prior assumptions, we find agreement within ±2σ between the C/O of the host (0.52 ± 0.05) and brown dwarf (0.43-0.63), as expected from a molecular cloud collapse formation scenario, but our retrieved metallicities are implausibly high (0.6-0.8) in light of the excellent agreement of the data with the solar-abundance model grid. Future work on our retrieval framework will seek to resolve this tension. Additional study of low surface gravity objects is necessary to assess the influence of a dynamical mass prior on atmospheric analysis
Episode 6: Medtronic DC1516
Get PDFEpisode 6:
This episode features three alums from the class of 2016: Marina Biggio, Bethany Claps, and Dakota Murray. Their Design Clinic project with Medtronic was on the design of a Veress needle indicator for minimally invasive surgery
Celebrating Faculty Scholarship 2023
Get PDFScroll down to view the bibliography of selected scholarly and creative work produced by Smith College faculty and submitted by faculty for the 2023 celebration which took place in the Neilson Library Skyline Reading Room, Smith College on April 26, 2023.https://scholarworks.smith.edu/celebratingfacultyscholarshipbiblios/1001/thumbnail.jp
The Importance of Mentorship in Fostering Change Among Young Parents Utilizing Co-Creation Principles
No full textUpdated Virophage Taxonomy and Distinction from Polinton-Like Viruses
Get PDFVirophages are small dsDNA viruses that hijack the machinery of giant viruses during the co-infection of a protist (i.e., microeukaryotic) host and represent an exceptional case of “hyperparasitism” in the viral world. While only a handful of virophages have been isolated, a vast diversity of virophage-like sequences have been uncovered from diverse metagenomes. Their wide ecological distribution, idiosyncratic infection and replication strategy, ability to integrate into protist and giant virus genomes and potential role in antiviral defense have made virophages a topic of broad interest. However, one limitation for further studies is the lack of clarity regarding the nomenclature and taxonomy of this group of viruses. Specifically, virophages have been linked in the literature to other “virophage-like” mobile genetic elements and viruses, including polinton-like viruses (PLVs), but there are no formal demarcation criteria and proper nomenclature for either group, i.e., virophage or PLVs. Here, as part of the ICTV Virophage Study Group, we leverage a large set of genomes gathered from published datasets as well as newly generated protist genomes to propose delineation criteria and classification methods at multiple taxonomic ranks for virophages ‘sensu stricto’, i.e., genomes related to the prototype isolates Sputnik and mavirus. Based on a combination of comparative genomics and phylogenetic analyses, we show that this group of virophages forms a cohesive taxon that we propose to establish at the class level and suggest a subdivision into four orders and seven families with distinctive ecogenomic features. Finally, to illustrate how the proposed delineation criteria and classification method would be used, we apply these to two recently published datasets, which we show include both virophages and other virophage-related elements. Overall, we see this proposed classification as a necessary first step to provide a robust taxonomic framework in this area of the virosphere, which will need to be expanded in the future to cover other virophage-related viruses such as PLVs
Updated Virophage Taxonomy and Distinction from Polinton-Like Viruses
Get PDFVirophages are small dsDNA viruses that hijack the machinery of giant viruses during the co-infection of a protist (i.e., microeukaryotic) host and represent an exceptional case of “hyperparasitism” in the viral world. While only a handful of virophages have been isolated, a vast diversity of virophage-like sequences have been uncovered from diverse metagenomes. Their wide ecological distribution, idiosyncratic infection and replication strategy, ability to integrate into protist and giant virus genomes and potential role in antiviral defense have made virophages a topic of broad interest. However, one limitation for further studies is the lack of clarity regarding the nomenclature and taxonomy of this group of viruses. Specifically, virophages have been linked in the literature to other “virophage-like” mobile genetic elements and viruses, including polinton-like viruses (PLVs), but there are no formal demarcation criteria and proper nomenclature for either group, i.e., virophage or PLVs. Here, as part of the ICTV Virophage Study Group, we leverage a large set of genomes gathered from published datasets as well as newly generated protist genomes to propose delineation criteria and classification methods at multiple taxonomic ranks for virophages ‘sensu stricto’, i.e., genomes related to the prototype isolates Sputnik and mavirus. Based on a combination of comparative genomics and phylogenetic analyses, we show that this group of virophages forms a cohesive taxon that we propose to establish at the class level and suggest a subdivision into four orders and seven families with distinctive ecogenomic features. Finally, to illustrate how the proposed delineation criteria and classification method would be used, we apply these to two recently published datasets, which we show include both virophages and other virophage-related elements. Overall, we see this proposed classification as a necessary first step to provide a robust taxonomic framework in this area of the virosphere, which will need to be expanded in the future to cover other virophage-related viruses such as PLVs
Building Community, Competency, and Creativity in Calculus 2: Summary of a pilot year of project implementation
Get PDFIn light of the COVID-19 pandemic, instructional modes at our institution moved to fully online and remote, then fully online but on campus, and back to in-person learning in fall 2021. To combat perceived issues in student engagement, we piloted using group projects in place of exams at the natural content break points in Calculus 2
Welcome to the Oops Club!: Varied Patterns of Mistake Responses in a Veteran Teacher’s Classroom
Get PDFThis study explores the range of distinct mistake responses that one veteran public school teacher employs with her class of 20 Kindergarten students during daily learning and teaching. Relying on more than 60 h of classroom observations and using a grounded theory approach, a micro-level, qualitative analysis of the teacher’s responses to each child’s mistakes was conducted, attending to words and actions during instructional interactions captured in fieldnotes and video recordings. Data analysis of observed teaching practices revealed five distinct patterns that the teacher used to help children correct academic and/or behavioral mistakes. The amount and type of teacher involvement ranged from little engagement with mistakes for students who rarely made any, to heavyhanded supports for children who routinely struggled to obtain right answers
