6,715 research outputs found
Bella y sus manchas
Victoria Rodrigo, PhD- Serie Leamos’ EditorProfessor of Spanish World Languages and Cultures DepartmentGeorgia State Universityhttps://scholarworks.gsu.edu/wcl_leamos/1001/thumbnail.jp
Virtual Cohorts and Synthetic Data in Dementia: An Illustration of Their Potential to Advance Research
When attempting to answer questions of interest, scientists often encounter hurdles that may stem from limited access to existing adequate datasets as a consequence of poor data sharing practices, constraining administrative practices. Further, when attempting to integrate data, differences in existing datasets also impose challenges that limit opportunities for data integration. As a result, the pace of scientific advancements is suboptimal. Synthetic data and virtual cohorts generated using innovative computational techniques represent an opportunity to overcome some of these limitations and consequently, to advance scientific developments. In this paper, we demonstrate the use of virtual cohorts techniques to generate a synthetic dataset that mirrors a deeply phenotyped sample of preclinical dementia research participants
Identifying Planetary Biosignature Impostors: Spectral Features of CO and O4 Resulting from Abiotic O2/O3 Production
O2 and O3 have been long considered the most robust individual biosignature
gases in a planetary atmosphere, yet multiple mechanisms that may produce them
in the absence of life have been described. However, these abiotic planetary
mechanisms modify the environment in potentially identifiable ways. Here we
briefly discuss two of the most detectable spectral discriminants for abiotic
O2/O3: CO and O4. We produce the first explicit self-consistent simulations of
these spectral discriminants as they may be seen by JWST. If JWST-NIRISS and/or
NIRSpec observe CO (2.35, 4.6 um) in conjunction with CO2 (1.6, 2.0, 4.3 um) in
the transmission spectrum of a terrestrial planet it could indicate robust CO2
photolysis and suggest that a future detection of O2 or O3 might not be
biogenic. Strong O4 bands seen in transmission at 1.06 and 1.27 um could be
diagnostic of a post-runaway O2-dominated atmosphere from massive H-escape. We
find that for these false positive scenarios, CO at 2.35 um, CO2 at 2.0 and 4.3
um, and O4 at 1.27 um are all stronger features in transmission than O2/O3 and
could be detected with SNRs 3 for an Earth-size planet orbiting a
nearby M dwarf star with as few as 10 transits, assuming photon-limited noise.
O4 bands could also be sought in UV/VIS/NIR reflected light (at 0.345, 0.36,
0.38, 0.445, 0.475, 0.53, 0.57, 0.63, 1.06, and 1.27 um) by a next generation
direct-imaging telescope such as LUVOIR/HDST or HabEx and would indicate an
oxygen atmosphere too massive to be biologically produced.Comment: 7 pages, 4 figures, accepted to the Astrophysical Journal Letter
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