244 research outputs found
A Study of Layered Learning in Oncology
Objective. To explore use of pharmacy learners as a means to expand pharmacy services in a layered learning practice model (LLPM), to examine whether an LLPM environment precludes achievement of knowledge-based learning objectives, and to explore learner perception of the experience
Detection of a Satellite of the Trojan Asteroid (3548) Eurybates—A Lucy Mission Target
We describe the discovery of a satellite of the Trojan asteroid (3548) Eurybates in images obtained with the Hubble Space Telescope. The satellite was detected on three separate epochs, two in 2018 September and one in 2020 January. The satellite has a brightness in all three epochs consistent with an effective diameter of d₂ = 1.2 ± 0.4 km. The projected separation from Eurybates was s ~ 1700–2300 km and varied in position, consistent with a large range of possible orbits. Eurybates is a target of the Lucy Discovery mission and the early detection of a satellite provides an opportunity for a significant expansion of the scientific return from this encounter
Randomly barcoded transposon mutant libraries for gut commensals I: Strategies for efficient library construction.
Randomly barcoded transposon mutant libraries are powerful tools for studying gene function and organization, assessing gene essentiality and pathways, discovering potential therapeutic targets, and understanding the physiology of gut bacteria and their interactions with the host. However, construction of high-quality libraries with uniform representation can be challenging. In this review, we survey various strategies for barcoded library construction, including transposition systems, methods of transposon delivery, optimal library size, and transconjugant selection schemes. We discuss the advantages and limitations of each approach, as well as factors to consider when selecting a strategy. In addition, we highlight experimental and computational advances in arraying condensed libraries from mutant pools. We focus on examples of successful library construction in gut bacteria and their application to gene function studies and drug discovery. Given the need for understanding gene function and organization in gut bacteria, we provide a comprehensive guide for researchers to construct randomly barcoded transposon mutant libraries
TNOs are Cool: A survey of the trans-Neptunian region V. Physical characterization of 18 Plutinos using Herschel PACS observations
We present Herschel PACS photometry of 18 Plutinos and determine sizes and
albedos for these objects using thermal modeling. We analyze our results for
correlations, draw conclusions on the Plutino size distribution, and compare to
earlier results. Flux densities are derived from PACS mini scan-maps using
specialized data reduction and photometry methods. In order to improve the
quality of our results, we combine our PACS data with existing Spitzer MIPS
data where possible, and refine existing absolute magnitudes for the targets.
The physical characterization of our sample is done using a thermal model.
Uncertainties of the physical parameters are derived using customized Monte
Carlo methods. The correlation analysis is performed using a bootstrap Spearman
rank analysis. We find the sizes of our Plutinos to range from 150 to 730 km
and geometric albedos to vary between 0.04 and 0.28. The average albedo of the
sample is 0.08 \pm 0.03, which is comparable to the mean albedo of Centaurs,
Jupiter Family comets and other Trans-Neptunian Objects. We were able to
calibrate the Plutino size scale for the first time and find the cumulative
Plutino size distribution to be best fit using a cumulative power law with q =
2 at sizes ranging from 120-400 km and q = 3 at larger sizes. We revise the
bulk density of 1999 TC36 and find a density of 0.64 (+0.15/-0.11) g cm-3. On
the basis of a modified Spearman rank analysis technique our Plutino sample
appears to be biased with respect to object size but unbiased with respect to
albedo. Furthermore, we find biases based on geometrical aspects and color in
our sample. There is qualitative evidence that icy Plutinos have higher albedos
than the average of the sample.Comment: 18 pages, 8 figures, 8 tables, accepted for publication in A&
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