1,119,478 results on '"Julie In"'
Search Results
2. Development and Evaluation of an Intensive Short Course: The Quantitative Microbial Risk Assessment Interdisciplinary Instructional Institute (QMRA III)
- Author
-
Jade Mitchell, Hongwan Li, Mark H. Weir, Julie Libarkin, and Emily Pasek
- Abstract
Quantitative microbial risk assessment (QMRA) is a growing interdisciplinary field addressing exposures to microbial pathogens and infectious disease processes. Risk science is inherently interdisciplinary, but few of the contributing disciplinary programs offer courses and training specifically in QMRA. To develop multidisciplinary training in QMRA, an annual 10-day long intensive workshop was conducted from 2015 to 2019--the Quantitative Microbial Risk Assessment Interdisciplinary Instructional Institute (QMRA III). National leaders in the fields of public health, engineering, microbiology, epidemiology, communications, public policy, and QMRA served as instructors and mentors over the course of the program. To provide cross-training, multidisciplinary teams of 5-6 trainees were created from the approximately 30 trainees each year. A formal assessment of the program was performed based on observations and surveys containing Likert-type scales and open-ended prompts. In addition, a longitudinal alumni survey was also disseminated to facilitate the future redevelopment of QMRA institutes and determine the impact of the program. Across all years, trainees experienced statistically significant increases (P < 0.05) in their perceptions of their QMRA abilities (e.g., use of specific computer programs) and knowledge of QMRA constructs (e.g., risk management). In addition, 12 publications, three conference presentations, and two research grants were derived from the QMRA III institute projects or tangential research. The success of QMRA III indicates that a short course format can effectively address many multidisciplinary training needs. Key features of QMRA III, including the inter-disciplinary training approach, hands-on exercises, real-world institute projects, and interaction through a mentoring process, were vital for training multidisciplinary teams housing multiple forms of expertise. Future QMRA institutes are being redeveloped to leverage hybrid learning formats that can further the multidisciplinary training and mentoring objectives.
- Published
- 2024
3. Perennial biomass cropping and use: Shaping the policy ecosystem in European countries
- Author
-
John Clifton‐Brown, Astley Hastings, Moritz vonCossel, Donal Murphy‐Bokern, Jon McCalmont, Jeanette Whitaker, Efi Alexopoulou, Stefano Amaducci, Larisa Andronic, Christopher Ashman, Danny Awty‐Carroll, Rakesh Bhatia, Lutz Breuer, Salvatore Cosentino, William Cracroft‐Eley, Iain Donnison, Berien Elbersen, Andrea Ferrarini, Judith Ford, Jörg Greef, Julie Ingram, Iris Lewandowski, Elena Magenau, Michal Mos, Martin Petrick, Marta Pogrzeba, Paul Robson, Rebecca L. Rowe, Anatolii Sandu, Kai‐Uwe Schwarz, Danilo Scordia, Jonathan Scurlock, Anita Shepherd, Judith Thornton, Luisa M. Trindade, Sylvia Vetter, Moritz Wagner, Pei‐Chen Wu, Toshihiko Yamada, and Andreas Kiesel
- Subjects
BECCS ,bioeconomy value chains ,biomass utilisation ,circular economy ,energy security ,farm subsidies ,Renewable energy sources ,TJ807-830 ,Energy industries. Energy policy. Fuel trade ,HD9502-9502.5 - Abstract
Abstract Demand for sustainably produced biomass is expected to increase with the need to provide renewable commodities, improve resource security and reduce greenhouse gas emissions in line with COP26 commitments. Studies have demonstrated additional environmental benefits of using perennial biomass crops (PBCs), when produced appropriately, as a feedstock for the growing bioeconomy, including utilisation for bioenergy (with or without carbon capture and storage). PBCs can potentially contribute to Common Agricultural Policy (CAP) (2023–27) objectives provided they are carefully integrated into farming systems and landscapes. Despite significant research and development (R&D) investment over decades in herbaceous and coppiced woody PBCs, deployment has largely stagnated due to social, economic and policy uncertainties. This paper identifies the challenges in creating policies that are acceptable to all actors. Development will need to be informed by measurement, reporting and verification (MRV) of greenhouse gas emissions reductions and other environmental, economic and social metrics. It discusses interlinked issues that must be considered in the expansion of PBC production: (i) available land; (ii) yield potential; (iii) integration into farming systems; (iv) R&D requirements; (v) utilisation options; and (vi) market systems and the socio‐economic environment. It makes policy recommendations that would enable greater PBC deployment: (1) incentivise farmers and land managers through specific policy measures, including carbon pricing, to allocate their less productive and less profitable land for uses which deliver demonstrable greenhouse gas reductions; (2) enable greenhouse gas mitigation markets to develop and offer secure contracts for commercial developers of verifiable low‐carbon bioenergy and bioproducts; (3) support innovation in biomass utilisation value chains; and (4) continue long‐term, strategic R&D and education for positive environmental, economic and social sustainability impacts.
- Published
- 2023
- Full Text
- View/download PDF
4. Quartz Clouds in the Dayside Atmosphere of the Quintessential Hot Jupiter HD 189733 b
- Author
-
Julie Inglis, Natasha E. Batalha, Nikole K. Lewis, Tiffany Kataria, Heather A. Knutson, Brian M. Kilpatrick, Anna Gagnebin, Sagnick Mukherjee, Maria M. Pettyjohn, Ian J. M. Crossfield, Trevor O. Foote, David Grant, Gregory W. Henry, Maura Lally, Laura K. McKemmish, David K. Sing, Hannah R. Wakeford, Juan C. Zapata Trujillo, and Robert T. Zellem
- Subjects
Exoplanet atmospheres ,Exoplanet atmospheric composition ,Exoplanet astronomy ,Hot Jupiters ,Astrophysics ,QB460-466 - Abstract
Recent mid-infrared observations with JWST's Mid-Infrared Instrument Low Resolution Spectrometer (MIRI LRS) have resulted in the first direct detections of absorption features from silicate clouds in the transmission spectra of two transiting exoplanets, WASP-17 b and WASP-107 b. In this Letter, we measure the mid-infrared (5–12 μ m) dayside emission spectrum of the benchmark hot Jupiter HD 189733 b with MIRI LRS by combining data from two secondary-eclipse observations. We confirm the previous detection of H _2 O absorption at 6.5 μ m from Spitzer's Infrared Spectrograph (IRS) and additionally detect H _2 S as well as an absorption feature at 8.7 μ m in both secondary-eclipse observations. The excess absorption at 8.7 μ m can be explained by the presence of small (∼0.01 μ m) grains of SiO _2 [s] in the uppermost layers of HD 189733 b’s dayside atmosphere. This is the first direct detection of silicate clouds in HD 189733 b’s atmosphere, and the first detection of a distinct absorption feature from silicate clouds on the dayside of any hot Jupiter. We find that models including SiO _2 [s] are preferred by 6–7 σ over clear models and those with other potential cloud species. The high-altitude location of these silicate particles is best explained by formation in the hottest regions of HD 189733 b’s dayside atmosphere near the substellar point. We additionally find that HD 189733 b’s emission spectrum longward of 9 μ m displays residual features not well captured by our current atmospheric models. When combined with other JWST observations of HD 189733 b’s transmission and emission spectra at shorter wavelengths, these observations will provide us with the most detailed picture to date of the atmospheric composition and cloud properties of this benchmark hot Jupiter.
- Published
- 2024
- Full Text
- View/download PDF
5. COVID-19 Diarrhea is Inflammatory, Caused by Direct Viral Effects Plus Major Role of Virus-induced CytokinesSummary
- Author
-
Mark Donowitz, Chung-Ming Tse, Rafiq Sarker, Ruxian Lin, Karol Dokladny, Manmeet Rawat, Ivy Horwitz, ChunYan Ye, George McNamara, Julie In, Alison Kell, Chenxu Guo, Shang JuiTsai, Tyrus Vong, Andrew Karaba, Varsha Singh, Jaiprasath Sachithanandham, Andy Pekosz, Andrea Cox, Steven Bradfute, Nicholas C. Zachos, Steven Gould, and Olga Kovbasnjuk
- Subjects
CaCC ,Cytokines ,Diarrhea ,DRA ,NHE3 ,SARS-CoV-2 ,Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
Background & Aims: Diarrhea occurs in up to 50% of cases of COVID-19. Nonetheless, the pathophysiologic mechanism(s) have not been determined. Methods: This was examined using normal human enteroid monolayers exposed apically to live SARS-CoV-2 or non-replicating virus-like particles (VLPs) bearing the 4 SARS-CoV-2 structural proteins or irradiated virus, all of which bound and entered enterocytes. Results: Live virus and VLPs incrieased secretion of multiple cytokines and reduced mRNAs of ACE2, NHE3, and DRA. Interleukin (IL)-6 plus IL-8 alone reduced NHE3 mRNA and protein and DRA mRNA and protein. Neither VLPs nor IL-6 plus IL-8 alone altered Cl- secretion, but together they caused Cl- secretion, which was Ca2+-dependent, CFTR-independent, blocked partially by a specific TMEM16A inhibitor, and entirely by a general TMEM16 family inhibitor. VLPs and irradiated virus, but not IL-6 plus IL-8, produced Ca2+ waves that began within minutes of VLP exposure, lasted for at least 60 minutes, and were prevented by pretreatment with apyrase, a P2Y1 receptor antagonist, and general TMEM16 family inhibitor but not by the specific TMEM16A inhibitor. Conclusions: The pathophysiology of COVID-19 diarrhea appears to be a unique example of a calcium-dependent inflammatory diarrhea that is caused by direct viral effects plus the virus-induced intestinal epithelial cytokine secretion.
- Published
- 2024
- Full Text
- View/download PDF
6. Debris Disks Can Contaminate Mid-infrared Exoplanet Spectra: Evidence for a Circumstellar Debris Disk around Exoplanet Host WASP-39
- Author
-
Laura Flagg, Alycia J. Weinberger, Taylor J. Bell, Luis Welbanks, Giuseppe Morello, Diana Powell, Jacob L. Bean, Jasmina Blecic, Nicolas Crouzet, Peter Gao, Julie Inglis, James Kirk, Mercedes López-Morales, Karan Molaverdikhani, Nikolay Nikolov, Apurva V. Oza, Benjamin V. Rackham, Seth Redfield, Shang-Min Tsai, Ray Jayawardhana, Laura Kreidberg, Matthew C. Nixon, Kevin B. Stevenson, and Jake D. Turner
- Subjects
Debris disks ,Exoplanet atmospheres ,Infrared spectroscopy ,Spectral energy distribution ,Circumstellar dust ,Exoplanet evolution ,Astrophysics ,QB460-466 - Abstract
The signal from a transiting planet can be diluted by astrophysical contamination. In the case of circumstellar debris disks, this contamination could start in the mid-infrared and vary as a function of wavelength, which would then change the observed transmission spectrum for any planet in the system. The MIRI/Low Resolution Spectrometer WASP-39b transmission spectrum shows an unexplained dip starting at ∼10 μ m that could be caused by astrophysical contamination. The spectral energy distribution displays excess flux at similar levels to that which are needed to create the dip in the transmission spectrum. In this Letter, we show that this dip is consistent with the presence of a bright circumstellar debris disk, at a distance of >2 au. We discuss how a circumstellar debris disk like that could affect the atmosphere of WASP-39b. We also show that even faint debris disks can be a source of contamination in MIRI exoplanet spectra.
- Published
- 2024
- Full Text
- View/download PDF
7. GJ 367b Is a Dark, Hot, Airless Sub-Earth
- Author
-
Michael Zhang, Renyu Hu, Julie Inglis, Fei Dai, Jacob L. Bean, Heather A. Knutson, Kristine Lam, Elisa Goffo, and Davide Gandolfi
- Subjects
Exoplanet atmospheres ,Exoplanet surface composition ,James Webb Space Telescope ,Extrasolar rocky planets ,Astrophysics ,QB460-466 - Abstract
We present the mid-infrared (5–12 μ m) phase curve of GJ 367b observed by the Mid-Infrared Instrument on the James Webb Space Telescope (JWST). GJ 367b is a hot ( T _eq = 1370 K), extremely dense (10.2 ± 1.3 g cm ^−3 ) sub-Earth orbiting an M dwarf on a 0.32 day orbit. We measure an eclipse depth of 79 ± 4 ppm, a nightside planet-to-star flux ratio of 4 ± 8 ppm, and a relative phase amplitude of 0.97 ± 0.10, all fully consistent with a zero-albedo planet with no heat recirculation. Such a scenario is also consistent with the phase offset of 11°E ± 5° to within 2.2 σ . The emission spectrum is likewise consistent with a blackbody with no heat redistribution and a low albedo of A _B ≈ 0.1, with the exception of one anomalous wavelength bin that we attribute to unexplained systematics. The emission spectrum puts few constraints on the surface composition but rules out a CO _2 atmosphere ≳1 bar, an outgassed atmosphere ≳10 mbar (under heavily reducing conditions), or an outgassed atmosphere ≳0.01 mbar (under heavily oxidizing conditions). The lack of day–night heat recirculation implies that 1 bar atmospheres are ruled out for a wide range of compositions, while 0.1 bar atmospheres are consistent with the data. Taken together with the fact that most of the dayside should be molten, our JWST observations suggest that the planet must have lost the vast majority of its initial inventory of volatiles.
- Published
- 2024
- Full Text
- View/download PDF
8. Seven new 'cryptic' species of Discodorididae (Mollusca, Gastropoda, Nudibranchia) from New Caledonia
- Author
-
Julie Innabi, Carla C. Stout, and Ángel Valdés
- Subjects
Zoology ,QL1-991 - Abstract
The study of a well-preserved collection of discodorid nudibranchs collected in Koumac, New Caledonia, revealed the presence of seven species new to science belonging to the genera Atagema, Jorunna, Rostanga, and Sclerodoris, although some of the generic assignments are tentative as the phylogeny of Discodorididae remains unresolved. Moreover, a poorly known species of Atagema originally described from New Caledonia is re-described and the presence of Sclerodoris tuberculata in New Caledonia is confirmed with molecular data. All the species described herein are highly cryptic on their food source and in the context of the present study the term “cryptic” is used to denote such species. This paper highlights the importance of comprehensive collecting efforts to identify and document well-camouflaged taxa.
- Published
- 2023
- Full Text
- View/download PDF
9. The mobile vaccine equity enhancement program–a model program for enhancing equity in vaccine availability based at a large health care system
- Author
-
John Broach, Olga Brown, Caitlin McEachern, Janell Forget, Peter Lancette, Norman Soucie, Julie Inzerillo, Robert Klugman, Stephen Tosi, Abraham Haddad, Pamela Manor, Richard Bylund, Gio Dellostritto, Max Grecchi, Connie Camelo, Jeanne Shirshac, Katharine Eshghi, Nardy Vega, Stacy Hampson, Kassandra Follwell, Rafael Gonzalez, Theresa Hicks, Victoria McCandless, Timothy VanStratten, Mina Botros, Tracy Jalbert, Catherine Merwin, Wendy Schellhammer, Ian Pelto, Maggie Rodriguez, Cheryl LaPriore, Monica Lowell, Elizabeth Radigan, Lorie Gull, Alana Gruszecki, Sarah Benoit, Eric Dickson, and Michelle Muller
- Subjects
vaccine ,COVID ,pandemic (COVID19) ,equity ,mobile healthcare application ,Public aspects of medicine ,RA1-1270 - Abstract
The SARS CoV-2 (COVID-19) pandemic presented unprecedented challenges as communities attempted to respond to the administration of a novel vaccine that faced cold chain logistical requirements and vaccine hesitancy among many, as well as complicated phased rollout plans that changed frequently as availability of the vaccine waxed and waned. The COVID-19 pandemic also disproportionately affected communities of color and communities with barriers to accessing healthcare. In the setting of these difficulties, a program was created specifically to address inequity in vaccine administration with a focus on communities of color and linguistic diversity as well as those who had technological barriers to online sign-up processes common at mass vaccination sites. This effort, the Mobile Vaccine Equity Enhancement Program (MVeeP), delivered over 12,000 vaccines in 24 months through a reproducible set of practices that can inform equity-driven vaccine efforts in future pandemics.
- Published
- 2023
- Full Text
- View/download PDF
10. Editorial: The social side of agroecological systems: farmers’ adaptation capacity
- Author
-
Sandra Ricart, Julie Ingram, A Amarender Reddy, Nicholas A. Cradock-Henry, and Nicholas Kirk
- Subjects
agroecological systems ,adaptive capacity ,resilient landscapes ,agricultural innovation ,extension programs ,hydrosocial territories ,Agriculture ,Plant culture ,SB1-1110 - Published
- 2023
- Full Text
- View/download PDF
11. Teacher Residencies: State and Federal Policy to Support Comprehensive Teacher Preparation
- Author
-
Learning Policy Institute, EdPrepLab, Ryan Saunders, Julie Fitz, Michael A. DiNapoli, and Tara Kini
- Abstract
As school systems work to recover from the COVID-19 pandemic, states continue to grapple with persistent teacher shortages, a lack of teachers of color in the workforce, and high turnover rates undermining recruitment efforts. Teachers' effectiveness and their likelihood of staying in teaching are strongly influenced by the quality of preparation they receive, and well-designed teacher residencies have been found to support both of these outcomes. Research suggests that teacher candidates who receive their preparation through teacher residencies--which combine comprehensive, financially supported preparation with a post-program service requirement--tend to be retained in their districts longer than other candidates, on average, thereby lowering rates of new teacher attrition and reducing the need to hire more new teachers. This research is based on the initial designs for residencies that guided the federal legislation on residencies and several early state adoptions. States and the federal government are seeking policy strategies to better recruit, prepare, and retain a qualified teacher workforce. To understand the growing evidence and policy landscape, this report begins with an overview of research on the teacher residency model and then describes state and federal policy trends and opportunities supporting teacher residencies. This includes a look across recent efforts in 12 states to fund and grow high-quality, research-aligned residencies: Arizona, California, Delaware, Indiana, Mississippi, Montana, New Mexico, New York, Pennsylvania, Texas, Washington, and West Virginia.
- Published
- 2024
12. Learning through Collaboration: Reflections on Cultivating Cross-Institutional Capacity for Place-Based Community Engagement
- Author
-
Carmine Perrotti, Nicholas V. Longo, Julie L. Plaut, and Adam Bush
- Abstract
This article highlights the nascent efforts between College Unbound, Brown University, and Providence College--three very different types of institutions in Providence, Rhode Island--to foster cross-institutional capacity for place-based community engagement. By collectively engaging our institutions, we experimented with what collaboration around community engagement might look like within our local context. In this article, we share our approach and reflections in working to cultivate a place-based collaboration that is community-centric and grounded in students' lived experiences, along with limitations, lessons learned, and next steps related to our collaborative work. Through our efforts, we situate cross-institutional collaborations as an opportunity for more sustained and transformative work within higher education community engagement.
- Published
- 2024
13. Exploring the Relationship between Test-Optional Admissions and Selectivity and Enrollment Outcomes during the Pandemic. EdWorkingPaper No. 24-982
- Author
-
Annenberg Institute for School Reform at Brown University, Kelly Rosinger, Dominique J. Baker, Joseph Sturm, Wan Yu, Julie J. Park, OiYan Poon, Brian Heseung Kim, and Stephanie Breen
- Abstract
Most selective colleges implemented test-optional admissions during the pandemic, making college entrance exam scores optional for applicants. We draw on descriptive, two-way fixed effects, and event study methods to examine variation in test-optional implementation during the pandemic and how implementation relates to selectivity and enrollment. For "test-optional" colleges during the pandemic, we found substantial variation in policy type (e.g., test optional, test free) and whether the policy extended to all applicants and scholarship consideration. Findings suggest test-optional implementation related to increases in Black student enrollment, mostly at moderately selective colleges and when policies extended to all applicants and scholarships. At highly selective colleges, findings suggest test-optional implementation related to an increase in applications but not consistent gains in enrollment.
- Published
- 2024
14. State Approaches to Developing Educational Leaders
- Author
-
Learning Policy Institute, Julie Fitz, Marjorie E. Wechsler, and Stephanie Levin
- Abstract
High-quality professional learning can support in-service leaders' effectiveness by developing the skills, knowledge, and competencies necessary for addressing their full range of leadership responsibilities. however, recent data show that leaders' access to professional learning varies across states and communities and that leaders in high-poverty schools are less likely than those in low-poverty schools to have high-quality learning opportunities. States can expand access to leadership development and make access more equitable by investing in ongoing statewide initiatives, such as leadership academies or institutes. Building the infrastructure for leadership-relevant professional learning can allow for long-term capacity building of a state's leadership workforce and create opportunities for leaders to access a continuum of support over the course of their career. The purpose of this study was to understand the infrastructure that states have built for leadership-relevant professional learning by identifying the long-term leadership development initiatives supported by states and analyzing their purposes, target audiences, and scope. They conducted a scan between March and May of 2023 using search engines, state department of education websites, and other web-based documents. The researchers found that at least 26 states support ongoing statewide leadership development initiatives to build the knowledge and skills of in-service leaders. This report provides examples of different states' initiatives related to each of these functions. It also briefly addresses the federal, state, and local funding sources that states draw on to develop and sustain these initiatives.
- Published
- 2024
15. Report on the Condition of Education 2024. NCES 2024-144
- Author
-
National Center for Education Statistics (NCES) (ED/IES), American Institutes for Research (AIR), Véronique Irwin, Ke Wang, Julie Jung, Tabitha Tezil, Sara Alhassani, Alison Filbey, Rita Dilig, and Farrah Bullock Mann
- Abstract
The "Report on the Condition of Education" is an annual report from the National Center for Education Statistics (NCES) that is mandated by the United States Congress. Using data from NCES and other sources, NCES compiles a set of "indicators" of the condition of education in the United States at all levels, from prekindergarten through postsecondary, as well as labor force outcomes and international comparisons. The full contents of the Condition of Education Indicator System can be accessed online or by downloading PDFs for the individual indicators. The "Report on the Condition of Education 2024" comprises key findings from the Indicator System. This summary report provides a brief overview of information available on various topics as well as direct links to the online versions of indicators discussed. This year's report also includes select content from sources outside the Indicator System, such as the National Assessment of Educational Progress (NAEP) and the Integrated Postsecondary Education System (IPEDS).
- Published
- 2024
16. Atmospheric Characterization of the Super-Jupiter HIP 99770 b with KPIC
- Author
-
Yapeng Zhang, Jerry W. Xuan, Dimitri Mawet, Jason J. Wang, Chih-Chun Hsu, Jean-Bapiste Ruffio, Heather A. Knutson, Julie Inglis, Geoffrey A. Blake, Yayaati Chachan, Katelyn Horstman, Ashley Baker, Randall Bartos, Benjamin Calvin, Sylvain Cetre, Jacques-Robert Delorme, Greg Doppmann, Daniel Echeverri, Luke Finnerty, Michael P. Fitzgerald, Nemanja Jovanovic, Joshua Liberman, Ronald A. López, Evan Morris, Jacklyn Pezzato, Ben Sappey, Tobias Schofield, Andrew Skemer, J. Kent Wallace, Ji Wang, and Clarissa R. Do Ó
- Subjects
Exoplanet atmospheres ,High resolution spectroscopy ,Substellar companion stars ,Astronomy ,QB1-991 - Abstract
Young, self-luminous super-Jovian companions discovered by direct imaging provide a challenging test for planet formation and evolution theories. By spectroscopically characterizing the atmospheric compositions of these super-Jupiters, we can constrain their formation histories. Here we present studies of the recently discovered HIP 99770 b, a 16 M _Jup high-contrast companion on a 17 au orbit, using the fiber-fed high-resolution spectrograph KPIC ( ${ \mathcal R }$ ∼ 35,000) on the Keck II telescope. Our K -band observations led to detections of H _2 O and CO in the atmosphere of HIP 99770 b. We carried out free retrieval analyses using petitRADTRANS to measure its chemical abundances, including the metallicity and C/O ratio, projected rotation velocity ( $v\sin i$ ), and radial velocity (RV). We found that the companion’s atmosphere has C/O $=\,{0.55}_{-0.04}^{+0.06}$ and [M/H] $=\,{0.26}_{-0.23}^{+0.24}$ (1 σ confidence intervals), values consistent with those of the Sun and with a companion formation via gravitational instability or core accretion. The projected rotation velocity $v\sin (i)\lt 7.8$ km s ^−1 is small relative to other directly imaged companions with similar masses and ages. This may imply a nearly pole-on orientation or effective magnetic braking by a circumplanetary disk. In addition, we added the companion-to-primary relative RV measurement to the orbital fitting and obtained updated constraints on orbital parameters. Detailed characterization of super-Jovian companions within 20 au like HIP 99770 b is critical for understanding the formation histories of this population.
- Published
- 2024
- Full Text
- View/download PDF
17. Are These Planets or Brown Dwarfs? Broadly Solar Compositions from High-resolution Atmospheric Retrievals of ∼10–30 M Jup Companions
- Author
-
Jerry W. Xuan, Chih-Chun Hsu, Luke Finnerty, Jason Wang, Jean-Baptiste Ruffio, Yapeng Zhang, Heather A. Knutson, Dimitri Mawet, Eric E. Mamajek, Julie Inglis, Nicole L. Wallack, Marta L. Bryan, Geoffrey A. Blake, Paul Mollière, Neda Hejazi, Ashley Baker, Randall Bartos, Benjamin Calvin, Sylvain Cetre, Jacques-Robert Delorme, Greg Doppmann, Daniel Echeverri, Michael P. Fitzgerald, Nemanja Jovanovic, Joshua Liberman, Ronald A. López, Evan Morris, Jacklyn Pezzato, Ben Sappey, Tobias Schofield, Andrew Skemer, J. Kent Wallace, Ji Wang, Shubh Agrawal, and Katelyn Horstman
- Subjects
Exoplanet atmospheres ,Brown dwarfs ,High resolution spectroscopy ,Exoplanet atmospheric composition ,Atmospheric clouds ,Exoplanet formation ,Astrophysics ,QB460-466 - Abstract
Using Keck Planet Imager and Characterizer high-resolution ( R ∼ 35,000) spectroscopy from 2.29 to 2.49 μ m, we present uniform atmospheric retrievals for eight young substellar companions with masses of ∼10–30 M _Jup , orbital separations spanning ∼50–360 au, and T _eff between ∼1500 and 2600 K. We find that all companions have solar C/O ratios and metallicities to within the 1 σ –2 σ level, with the measurements clustered around solar composition. Stars in the same stellar associations as our systems have near-solar abundances, so these results indicate that this population of companions is consistent with formation via direct gravitational collapse. Alternatively, core accretion outside the CO snowline would be compatible with our measurements, though the high mass ratios of most systems would require rapid core assembly and gas accretion in massive disks. On a population level, our findings can be contrasted with abundance measurements for directly imaged planets with m < 10 M _Jup , which show tentative atmospheric metal enrichment compared to their host stars. In addition, the atmospheric compositions of our sample of companions are distinct from those of hot Jupiters, which most likely form via core accretion. For two companions with T _eff ∼ 1700–2000 K ( κ And b and GSC 6214–210 b), our best-fit models prefer a nongray cloud model with >3 σ significance. The cloudy models yield 2 σ −3 σ lower T _eff for these companions, though the C/O and [C/H] still agree between cloudy and clear models at the 1 σ level. Finally, we constrain ^12 CO/ ^13 CO for three companions with the highest signal-to-noise ratio data (GQ Lup b, HIP 79098b, and DH Tau b) and report $v\sin i$ and radial velocities for all companions.
- Published
- 2024
- Full Text
- View/download PDF
18. Orbital and Atmospheric Characterization of the 1RXS J034231.8+121622 System using High-resolution Spectroscopy Confirms that the Companion is a Low-mass Star
- Author
-
Clarissa R. Do Ó, Ben Sappey, Quinn M. Konopacky, Jean-Baptiste Ruffio, Kelly K. O’Neil, Tuan Do, Gregory Martinez, Travis S. Barman, Jayke S. Nguyen, Jerry W. Xuan, Christopher A. Theissen, Sarah Blunt, William Thompson, Chih-Chun Hsu, Ashley Baker, Randall Bartos, Geoffrey A. Blake, Benjamin Calvin, Sylvain Cetre, Jacques-Robert Delorme, Greg Doppmann, Daniel Echeverri, Luke Finnerty, Michael P. Fitzgerald, Julie Inglis, Nemanja Jovanovic, Ronald A. López, Dimitri Mawet, Evan Morris, Jacklyn Pezzato, Tobias Schofield, Andrew Skemer, J. Kent Wallace, Jason J. Wang, Ji Wang, and Joshua Liberman
- Subjects
Brown dwarfs ,Direct imaging ,High resolution spectroscopy ,Exoplanets ,Binary stars ,Orbit determination ,Astronomy ,QB1-991 - Abstract
The 1RXS J034231.8+121622 system consists of an M dwarf primary and a directly imaged low-mass stellar companion. We use high-resolution spectroscopic data from Keck/KPIC to estimate the objects' atmospheric parameters and radial velocities (RVs). Using PHOENIX stellar models, we find that the primary has a temperature of 3460 ± 50 K and a metallicity of 0.16 ± 0.04, while the secondary has a temperature of 2510 ± 50 K and a metallicity of ${0.13}_{-0.11}^{+0.12}$ . Recent work suggests this system is associated with the Hyades, giving it an older age than previous estimates. Both metallicities agree with current Hyades [Fe/H] measurements (0.11–0.21). Using stellar evolutionary models, we obtain significantly higher masses for the objects, 0.30 ± 0.15 M _⊙ and 0.08 ± 0.01 M _⊙ (84 ± 11 M _Jup ), respectively. Using the RVs and a new astrometry point from Keck/NIRC2, we find that the system is likely an edge-on, moderately eccentric ( ${0.41}_{-0.08}^{+0.27}$ ) configuration. We also estimate the C/O ratio of both objects using custom grid models, obtaining 0.42 ± 0.10 (primary) and 0.55 ± 0.10 (companion). From these results, we confirm that this system most likely went through a binary star formation process in the Hyades. The significant changes in this system's parameters since its discovery highlight the importance of high-resolution spectroscopy for both orbital and atmospheric characterization of directly imaged companions.
- Published
- 2024
- Full Text
- View/download PDF
19. Atmospheric Retrievals of the Young Giant Planet ROXs 42B b from Low- and High-resolution Spectroscopy
- Author
-
Julie Inglis, Nicole L. Wallack, Jerry W. Xuan, Heather A. Knutson, Yayaati Chachan, Marta L. Bryan, Brendan P. Bowler, Aishwarya Iyer, Tiffany Kataria, and Björn Benneke
- Subjects
Exoplanet atmospheres ,High resolution spectroscopy ,Atmospheric clouds ,Exoplanet atmospheric composition ,Exoplanet formation ,Astronomy ,QB1-991 - Abstract
Previous attempts have been made to characterize the atmospheres of directly imaged planets at low resolution ( R ∼ 10–100 s), but the presence of clouds has often led to degeneracies in the retrieved atmospheric abundances with cloud opacity and temperature structure that bias retrieved compositions. In this study, we perform retrievals on the ultrayoung (≲5 Myr) directly imaged planet ROXs 42B b with both a downsampled low-resolution JHK -band spectrum from Gemini/NIFS and Keck/OSIRIS, and a high-resolution K -band spectrum from pre-upgrade Keck/NIRSPAO. Using the atmospheric retrieval framework of petitRADTRANS , we analyze both data sets individually and combined. We additionally fit for the stellar abundances and other physical properties of the host stars, a young M spectral type binary, using the SPHINX model grid. We find that the measured C/O, 0.50 ± 0.05, and metallicity, [Fe/H] = −0.67 ± 0.35, for ROXs 42B b from our high-resolution spectrum agree with those of its host stars within 1 σ . The retrieved parameters from the high-resolution spectrum are also independent of our choice of cloud model. In contrast, the retrieved parameters from the low-resolution spectrum show strong degeneracies between the clouds and the retrieved metallicity and temperature structure. When we retrieve both data sets together, we find that these degeneracies are reduced but not eliminated, and the final results remain highly sensitive to cloud modeling choices. We conclude that high-resolution spectroscopy offers the most promising path for reliably determining atmospheric compositions of directly imaged companions independent of their cloud properties.
- Published
- 2024
- Full Text
- View/download PDF
20. Validation of Elemental and Isotopic Abundances in Late-M Spectral Types with the Benchmark HIP 55507 AB System
- Author
-
Jerry W. Xuan, Jason Wang, Luke Finnerty, Katelyn Horstman, Simon Grimm, Anne E. Peck, Eric Nielsen, Heather A. Knutson, Dimitri Mawet, Howard Isaacson, Andrew W. Howard, Michael C. Liu, Sam Walker, Mark W. Phillips, Geoffrey A. Blake, Jean-Baptiste Ruffio, Yapeng Zhang, Julie Inglis, Nicole L. Wallack, Aniket Sanghi, Erica J. Gonzales, Fei Dai, Ashley Baker, Randall Bartos, Charlotte Z. Bond, Marta L. Bryan, Benjamin Calvin, Sylvain Cetre, Jacques-Robert Delorme, Greg Doppmann, Daniel Echeverri, Michael P. Fitzgerald, Nemanja Jovanovic, Joshua Liberman, Ronald A. López, Emily C. Martin, Evan Morris, Jacklyn Pezzato, Garreth Ruane, Ben Sappey, Tobias Schofield, Andrew Skemer, Taylor Venenciano, J. Kent Wallace, Ji Wang, Peter Wizinowich, Yinzi Xin, Shubh Agrawal, Clarissa R. Do Ó, Chih-Chun Hsu, and Caprice L. Phillips
- Subjects
Atmospheric composition ,Stellar atmospheres ,Isotopic abundances ,Radial velocity ,Astrophysics ,QB460-466 - Abstract
M dwarfs are common host stars to exoplanets but often lack atmospheric abundance measurements. Late-M dwarfs are also good analogs to the youngest substellar companions, which share similar T _eff ∼ 2300–2800 K. We present atmospheric analyses for the M7.5 companion HIP 55507 B and its K6V primary star with Keck/KPIC high-resolution ( R ∼ 35,000) K -band spectroscopy. First, by including KPIC relative radial velocities between the primary and secondary in the orbit fit, we improve the dynamical mass precision by 60% and find ${M}_{B}={88.0}_{-3.2}^{+3.4}\,{M}_{\mathrm{Jup}}$ , putting HIP 55507 B above the stellar–substellar boundary. We also find that HIP 55507 B orbits its K6V primary star with $a={38}_{-3}^{+4}$ au and e = 0.40 ± 0.04. From atmospheric retrievals of HIP 55507 B, we measure [C/H] = 0.24 ± 0.13, [O/H] = 0.15 ± 0.13, and C/O = 0.67 ± 0.04. Moreover, we strongly detect ^13 CO (7.8 σ significance) and tentatively detect ${{\rm{H}}}_{2}^{18}{\rm{O}}$ (3.7 σ significance) in the companion’s atmosphere and measure ${}^{12}\mathrm{CO}{/}^{13}\mathrm{CO}={98}_{-22}^{+28}$ and ${{\rm{H}}}_{2}^{16}{\rm{O}}/{{\rm{H}}}_{2}^{18}{\rm{O}}={240}_{-80}^{+145}$ after accounting for systematic errors. From a simplified retrieval analysis of HIP 55507 A, we measure ${}^{12}\mathrm{CO}{/}^{13}\mathrm{CO}={79}_{-16}^{+21}$ and ${{\rm{C}}}^{16}{\rm{O}}/{{\rm{C}}}^{18}{\rm{O}}={288}_{-70}^{+125}$ for the primary star. These results demonstrate that HIP 55507 A and B have consistent ^12 C/ ^13 C and ^16 O/ ^18 O to the
- Published
- 2024
- Full Text
- View/download PDF
21. Developing Educational Leaders in California: The 21st Century California School Leadership Academy
- Author
-
Learning Policy Institute, Julie Fitz, Stephanie Levin, and Marjorie E. Wechsler
- Abstract
California has a notable history of investing in educational leaders' professional learning. In 1983, the state launched the California School Leadership Academy (CSLA), which it funded until the academy was discontinued due to statewide budget cuts in 2003. Research showed that CSLA was a source of high-quality professional development. In 2019, the state legislature reinvested in leaders' professional learning when it authorized the 21st Century California School Leadership Academy (21CSLA) to provide high-quality professional learning opportunities that are accessible and free of charge to California's PreK-12 educational leaders, including central office leaders, site leaders, and teacher leaders. The professional learning is delivered through seven regional academies that offer three primary types of learning opportunities: communities of practice (i.e., cohorts of leaders in similar roles collaboratively working on problems of practice), localized professional learning (i.e., learning opportunities developed in response to regional need), and individualized coaching by trained coaches. 21CSLA is one of several lead agencies that compose the California Statewide System of Support, an important part of the state's accountability and continuous improvement strategy that is designed to help local education agencies (LEAs) and their schools meet the needs of each student they serve. The purpose of this study is to understand how 21CSLA contributes to leadership development in California. Specifically, the study seeks to understand how 21CSLA currently supports the professional learning needs of educational leaders and how it fits within the broader state infrastructure to support educational improvement. The goal of the study is to inform policymakers and program administrators about the work and accomplishments of 21CSLA during the initiative's first 3-year grant cycle and point to ways in which the state can further support 21CSLA efforts to serve California's educational leaders.
- Published
- 2024
22. The Promises and Pitfalls of Using Language Models to Measure Instruction Quality in Education. EdWorkingPaper No. 24-948
- Author
-
Annenberg Institute for School Reform at Brown University, Paiheng Xu, Jing Liu, Nathan Jones, Julie Cohen, and Wei Ai
- Abstract
Assessing instruction quality is a fundamental component of any improvement efforts in the education system. However, traditional manual assessments are expensive, subjective, and heavily dependent on observers' expertise and idiosyncratic factors, preventing teachers from getting timely and frequent feedback. Different from prior research that focuses on low-inference instructional practices, this paper presents the first study that leverages Natural Language Processing (NLP) techniques to assess multiple high-inference instructional practices in two distinct educational settings: in-person K-12 classrooms and simulated performance tasks for pre-service teachers. This is also the first study that applies NLP to measure a teaching practice that has been demonstrated to be particularly effective for students with special needs. We confront two challenges inherent in NLP-based instructional analysis, including noisy and long input data and highly skewed distributions of human ratings. Our results suggest that pretrained Language Models (PLMs) demonstrate performances comparable to the agreement level of human raters for variables that are more discrete and require lower inference, but their efficacy diminishes with more complex teaching practices. Interestingly, using only teachers' utterances as input yields strong results for student-centered variables, alleviating common concerns over the difficulty of collecting and transcribing high-quality student speech data in in-person teaching settings. Our findings highlight both the potential and the limitations of current NLP techniques in the education domain, opening avenues for further exploration.
- Published
- 2024
23. Inequity and College Applications: Assessing Differences and Disparities in Letters of Recommendation from School Counselors with Natural Language Processing. EdWorkingPaper No. 24-953
- Author
-
Annenberg Institute for School Reform at Brown University, Brian Heseung Kim, Julie J. Park, Pearl Lo, Dominique Baker, Nancy Wong, Stephanie Breen, Huong Truong, Jia Zheng, Kelly Rosinger, and OiYan A. Poon
- Abstract
Letters of recommendation from school counselors are required to apply to many selective colleges and universities. Still, relatively little is known about how this non-standardized component may affect equity in admissions. We use cutting-edge natural language processing techniques to algorithmically analyze a national dataset of over 600,000 student applications and counselor recommendation letters submitted via the Common App platform. We examine how the length and topical content of letters (e.g., sentences about Personal Qualities, Athletics, Intellectual Promise, etc.) relate to student self-identified race/ethnicity, sex, and proxies for socioeconomic status. Paired with regression analyses, we explore whether demographic differences in letter characteristics persist when accounting for additional student, school, and counselor characteristics, as well as among letters written by the same counselor and among students with comparably competitive standardized test scores. We ultimately find large and noteworthy naïve differences in letter length and content across nearly all demographic groups, many in alignment with known inequities (e.g., many more sentences about Athletics among White and higher-SES students, longer letters and more sentences on Personal Qualities for private school students). However, these differences vary drastically based on the exact controls and comparison groups included -- demonstrating that the ultimate implications of these letter differences for equity hinges on exactly how and when letters are used in admissions processes (e.g., among which groups of students are they used to "break ties"?). Findings do not point to a clear recommendation whether institutions should keep or discard letter requirements, but reflect the importance of reading letters and overall applications in the context of structural opportunity. We discuss additional implications and possible recommendations for college access and admissions policy/practice.
- Published
- 2024
24. Examining School Sector and Mission in a Landscape of Parental Choice
- Author
-
Julie W. Dallavis
- Abstract
Researchers have considered how school choice policies affect student achievement, but less inquiry explores how the organization of schools may change in the presence of choice. This descriptive and exploratory paper analyzes a state representative sample of school mission statements at two time points: before the enactment of choice policies in Indiana, namely the Indiana Choice Scholarship Program, and again six years into the policy. Using structural topic modeling, this paper examines whether and how school mission statements topics have changed over this period. Descriptive findings suggest mission statement topics differ significantly between sectors but show few changes over time. The most striking shift is that Catholic and other private religious schools appear to be clarifying the religious aspects of their mission in the presence of robust choice policies.
- Published
- 2024
25. Chronic Inflammation in Ulcerative Colitis Causes Long-Term Changes in Goblet Cell FunctionSummary
- Author
-
Varsha Singh, Kelli Johnson, Jianyi Yin, Sun Lee, Ruxian Lin, Huimin Yu, Julie In, Jennifer Foulke-Abel, Nicholas C. Zachos, Mark Donowitz, and Yan Rong
- Subjects
Ulcerative Colitis ,Goblet Cell ,Mucus Layer ,Colonoids ,Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
Background & Aims: One of the features of ulcerative colitis (UC) is a defect in the protective mucus layer. This has been attributed to a reduced number of goblet cells (GCs). However, it is not known whether abnormal GC mucus secretion also contributes to the reduced mucus layer. Our aims were to investigate whether GC secretion was abnormal in UC and exists as a long-term effect of chronic inflammation. Methods: Colonoids were established from intestinal stem cells of healthy subjects (HS) and patients with UC. Colonoids were maintained as undifferentiated (UD) or induced to differentiate (DF) and studied as three-dimensional or monolayers on Transwell filters. Total RNA was extracted for quantitative real-time polymerase chain reaction analysis. Carbachol and prostaglandin E2 mediated mucin stimulation was examined by MUC2 IF/confocal microscopy and transmission electron microscopy. Results: Colonoids from UC patients can be propagated over many passages; however, they exhibit a reduced rate of growth and transepithelial electrical resistance compared with HS. Differentiated UC colonoid monolayers form a thin and non-continuous mucus layer. UC colonoids have increased expression of secretory lineage markers ATOH1 and SPDEF, along with MUC2 positive GCs, but failed to secrete mucin in response to the cholinergic agonist carbachol and prostaglandin E2, which caused increased secretion in HS. Exposure to tumor necrosis factor α (5 days) reduced the number of GCs, with a greater percentage decrease in UC colonoids compared with HS. Conclusions: Chronic inflammation in UC causes long-term changes in GCs, leading to abnormal mucus secretion. This continued defect in GC mucus secretion may contribute to the recurrence in UC.
- Published
- 2022
- Full Text
- View/download PDF
26. Detection of Carbon Monoxide in the Atmosphere of WASP-39b Applying Standard Cross-correlation Techniques to JWST NIRSpec G395H Data
- Author
-
Emma Esparza-Borges, Mercedes López-Morales, Jéa I. Adams Redai, Enric Pallé, James Kirk, Núria Casasayas-Barris, Natasha E. Batalha, Benjamin V. Rackham, Jacob L. Bean, S. L. Casewell, Leen Decin, Leonardo A. Dos Santos, Antonio García Muñoz, Joseph Harrington, Kevin Heng, Renyu Hu, Luigi Mancini, Karan Molaverdikhani, Giuseppe Morello, Nikolay K. Nikolov, Matthew C. Nixon, Seth Redfield, Kevin B. Stevenson, Hannah R. Wakeford, Munazza K. Alam, Björn Benneke, Jasmina Blecic, Nicolas Crouzet, Tansu Daylan, Julie Inglis, Laura Kreidberg, Dominique J. M. Petit dit de la Roche, and Jake D. Turner
- Subjects
Exoplanet atmospheres ,Exoplanet atmospheric composition ,Hot Jupiters ,Astronomical methods ,Astrophysics ,QB460-466 - Abstract
Carbon monoxide was recently reported in the atmosphere of the hot Jupiter WASP-39b using the NIRSpec PRISM transit observation of this planet, collected as part of the JWST Transiting Exoplanet Community Early Release Science Program. This detection, however, could not be confidently confirmed in the initial analysis of the higher-resolution observations with NIRSpec G395H disperser. Here we confirm the detection of CO in the atmosphere of WASP-39b using the NIRSpec G395H data and cross-correlation techniques. We do this by searching for the CO signal in the unbinned transmission spectrum of the planet between 4.6 and 5.0 μ m, where the contribution of CO is expected to be higher than that of other anticipated molecules in the planet’s atmosphere. Our search results in a detection of CO with a cross-correlation function (CCF) significance of 6.6 σ when using a template with only ^12 C ^16 O lines. The CCF significance of the CO signal increases to 7.5 σ when including in the template lines from additional CO isotopologues, with the largest contribution being from ^13 C ^16 O. Our results highlight how cross-correlation techniques can be a powerful tool for unveiling the chemical composition of exoplanetary atmospheres from medium-resolution transmission spectra, including the detection of isotopologues.
- Published
- 2023
- Full Text
- View/download PDF
27. Detection of Carbon Monoxide’s 4.6 Micron Fundamental Band Structure in WASP-39b’s Atmosphere with JWST NIRSpec G395H
- Author
-
David Grant, Joshua D. Lothringer, Hannah R. Wakeford, Munazza K. Alam, Lili Alderson, Jacob L. Bean, Björn Benneke, Jean-Michel Désert, Tansu Daylan, Laura Flagg, Renyu Hu, Julie Inglis, James Kirk, Laura Kreidberg, Mercedes López-Morales, Luigi Mancini, Thomas Mikal-Evans, Karan Molaverdikhani, Enric Palle, Benjamin V. Rackham, Seth Redfield, Kevin B. Stevenson, Jeff A. Valenti, Nicole L. Wallack, Keshav Aggarwal, Eva-Maria Ahrer, Ian J. M. Crossfield, Nicolas Crouzet, Nicolas Iro, Nikolay K. Nikolov, Peter J. Wheatley, and JWST Transiting Exoplanet Community ERS team
- Subjects
Exoplanet atmospheres ,Transmission spectroscopy ,Near infrared astronomy ,Astrophysics ,QB460-466 - Abstract
Carbon monoxide (CO) is predicted to be the dominant carbon-bearing molecule in giant planet atmospheres and, along with water, is important for discerning the oxygen and therefore carbon-to-oxygen ratio of these planets. The fundamental absorption mode of CO has a broad, double-branched structure composed of many individual absorption lines from 4.3 to 5.1 μ m, which can now be spectroscopically measured with JWST. Here we present a technique for detecting the rotational sub-band structure of CO at medium resolution with the NIRSpec G395H instrument. We use a single transit observation of the hot Jupiter WASP-39b from the JWST Transiting Exoplanet Community Early Release Science (JTEC ERS) program at the native resolution of the instrument ( R ∼ 2700) to resolve the CO absorption structure. We robustly detect absorption by CO, with an increase in transit depth of 264 ± 68 ppm, in agreement with the predicted CO contribution from the best-fit model at low resolution. This detection confirms our theoretical expectations that CO is the dominant carbon-bearing molecule in WASP-39b’s atmosphere and further supports the conclusions of low C/O and supersolar metallicities presented in the JTEC ERS papers for WASP-39b.
- Published
- 2023
- Full Text
- View/download PDF
28. MeDeT: Medical Device Digital Twins Creation with Few-shot Meta-learning
- Author
-
Sartaj, Hassan, Ali, Shaukat, and Gjøby, Julie Marie
- Subjects
Computer Science - Software Engineering - Abstract
Testing healthcare Internet of Things (IoT) applications at system and integration levels necessitates integrating numerous medical devices of various types. Challenges of incorporating medical devices are: (i) their continuous evolution, making it infeasible to include all device variants, and (ii) rigorous testing at scale requires multiple devices and their variants, which is time-intensive, costly, and impractical. Our collaborator, Oslo City's health department, faced these challenges in developing automated test infrastructure, which our research aims to address. In this context, we propose a meta-learning-based approach (MeDeT) to generate digital twins (DTs) of medical devices and adapt DTs to evolving devices. We evaluate MeDeT in OsloCity's context using five widely-used medical devices integrated with a real-world healthcare IoT application. Our evaluation assesses MeDeT's ability to generate and adapt DTs across various devices and versions using different few-shot methods, the fidelity of these DTs, the scalability of operating 1000 DTs concurrently, and the associated time costs. Results show that MeDeT can generate DTs with over 96% fidelity, adapt DTs to different devices and newer versions with reduced time cost (around one minute), and operate 1000 DTs in a scalable manner while maintaining the fidelity level, thus serving in place of physical devices for testing.
- Published
- 2024
29. Uncertainty-Aware Environment Simulation of Medical Devices Digital Twins
- Author
-
Sartaj, Hassan, Ali, Shaukat, and Gjøby, Julie Marie
- Subjects
Computer Science - Software Engineering - Abstract
Smart medical devices are an integral component of the healthcare Internet of Things (IoT), providing patients with various healthcare services through an IoT-based application. Ensuring the dependability of such applications through system and integration-level testing mandates the physical integration of numerous medical devices, which is costly and impractical. In this context, digital twins of medical devices play an essential role in facilitating testing automation. Testing with digital twins without accounting for uncertain environmental factors of medical devices leaves many functionalities of IoT-based healthcare applications untested. In addition, digital twins operating without environmental factors remain out of sync and uncalibrated with their corresponding devices functioning in the real environment. To deal with these challenges, in this paper, we propose a model-based approach (EnvDT) for modeling and simulating the environment of medical devices' digital twins under uncertainties. We empirically evaluate the EnvDT using three medicine dispensers, Karie, Medido, and Pilly connected to a real-world IoT-based healthcare application. Our evaluation targets analyzing the coverage of environment models and the diversity of uncertain scenarios generated for digital twins. Results show that EnvDT achieves approximately 61% coverage of environment models and generates diverse uncertain scenarios (with a near-maximum diversity value of 0.62) during multiple environmental simulations.
- Published
- 2024
30. The 2023 Balloon Flight of the ComPair Instrument
- Author
-
Smith, Lucas D., Cannady, Nicholas, Caputo, Regina, Kierans, Carolyn, Kirschner, Nicholas, Liceaga-Indart, Iker, McEnery, Julie, Metzler, Zachary, Moiseev, A. A., Parker, Lucas, Perkins, Jeremy, Sasaki, Makoto, Schoenwald, Adam J., Shy, Daniel, Valverde, Janeth, Wasti, Sambid, Woolf, Richard, Bolotnikov, Aleksey, Caligiure, Thomas J., Crosier, A. Wilder, Fried, Jack, Ghosh, Priyarshini, Griffin, Sean, Grove, J. Eric, Hays, Elizabeth, Kong, Emily, Mitchell, John, Phlips, Bernard, Sleator, Clio, Thompson, D. J., Wulf, Eric, and Zajczyk, Anna
- Subjects
Astrophysics - Instrumentation and Methods for Astrophysics - Abstract
The ComPair balloon instrument is a prototype gamma-ray telescope that aims to further develop technology for observing the gamma-ray sky in the MeV regime. ComPair combines four detector subsystems to enable parallel Compton scattering and pair-production detection, critical for observing in this energy range. This includes a 10 layer double-sided silicon strip detector tracker, a virtual Frisch grid low energy CZT calorimeter, a high energy CsI calorimeter, and a plastic scintillator anti-coincidence detector. The inaugural balloon flight successfully launched from the Columbia Scientific Balloon Facility site in Fort Sumner, New Mexico, in late August 2023, lasting approximately 6.5 hours in duration. In this proceeding, we discuss the development of the ComPair Since balloon payload, the performance during flight, and early results., Comment: 13 pages, 12 figures
- Published
- 2024
- Full Text
- View/download PDF
31. Topological mapping for traversability-aware long-range navigation in off-road terrain
- Author
-
Tremblay, Jean-François, Alhosh, Julie, Petit, Louis, Lotfi, Faraz, Landauro, Lara, and Meger, David
- Subjects
Computer Science - Robotics - Abstract
Autonomous robots navigating in off-road terrain like forests open new opportunities for automation. While off-road navigation has been studied, existing work often relies on clearly delineated pathways. We present a method allowing for long-range planning, exploration and low-level control in unknown off-trail forest terrain, using vision and GPS only. We represent outdoor terrain with a topological map, which is a set of panoramic snapshots connected with edges containing traversability information. A novel traversability analysis method is demonstrated, predicting the existence of a safe path towards a target in an image. Navigating between nodes is done using goal-conditioned behavior cloning, leveraging the power of a pretrained vision transformer. An exploration planner is presented, efficiently covering an unknown off-road area with unknown traversability using a frontiers-based approach. The approach is successfully deployed to autonomously explore two 400 meters squared forest sites unseen during training, in difficult conditions for navigation.
- Published
- 2024
32. Supercomputer 3D Digital Twin for User Focused Real-Time Monitoring
- Author
-
Bergeron, William, Hubbell, Matthew, Mojica, Daniel, Reuther, Albert, Arcand, William, Bestor, David, Burrill, Daniel, Chansup, Byun, Gadepally, Vijay, Houle, Michael, Jananthan, Hayden, Jones, Michael, Luszczek, Piotr, Michaleas, Peter, Milechin, Lauren, Prout, Julie Mullen Andrew, Rosa, Antonio, Yee, Charles, and Kepner, Jeremy
- Subjects
Computer Science - Distributed, Parallel, and Cluster Computing - Abstract
Real-time supercomputing performance analysis is a critical aspect of evaluating and optimizing computational systems in a dynamic user environment. The operation of supercomputers produce vast quantities of analytic data from multiple sources and of varying types so compiling this data in an efficient matter is critical to the process. MIT Lincoln Laboratory Supercomputing Center has been utilizing the Unity 3D game engine to create a Digital Twin of our supercomputing systems for several years to perform system monitoring. Unity offers robust visualization capabilities making it ideal for creating a sophisticated representation of the computational processes. As we scale the systems to include a diversity of resources such as accelerators and the addition of more users, we need to implement new analysis tools for the monitoring system. The workloads in research continuously change, as does the capability of Unity, and this allows us to adapt our monitoring tools to scale and incorporate features enabling efficient replay of system wide events, user isolation, and machine level granularity. Our system fully takes advantage of the modern capabilities of the Unity Engine in a way that intuitively represents the real time workload performed on a supercomputer. It allows HPC system engineers to quickly diagnose usage related errors with its responsive user interface which scales efficiently with large data sets.
- Published
- 2024
33. Sea Foam contains Hemoglycin from Cosmic Dust
- Author
-
McGeoch, Julie E. M. and McGeoch, Malcolm W.
- Subjects
Physics - Chemical Physics ,Astrophysics - Earth and Planetary Astrophysics ,Physics - Atmospheric and Oceanic Physics ,Physics - Geophysics - Abstract
In-falling cosmic dust has left evidence of meteoritic polymer amide in stromatolites, both fossil and modern. In search of evidence for continued present day in-fall sea foam was collected from two beaches in Rhode Island and subjected to Folch extraction to concentrate amphiphilic components in a chloroform water-methanol interphase layer. Hemoglycin polymer amide molecules previously characterized by MALDI mass spectrometry in meteorites and stromatolites were identified in sea foam either directly, or via their fragmentation patterns. Residual isotope enrichment pointed to an extra-terrestrial origin. The unique resiliency of sea foam may be due to the formation of extended hemoglycin lattices that stabilize its closed-cell structure and its lightness can potentially be explained by photolytic hydrogen production., Comment: 32 pages, 11 figures, 4 Tables
- Published
- 2024
34. Automation from the Worker's Perspective
- Author
-
Armstrong, Ben, Chen, Valerie K., Cuellar, Alex, Forsey-Smerek, Alexandra, and Shah, Julie A.
- Subjects
Computer Science - Human-Computer Interaction ,Computer Science - Robotics - Abstract
Common narratives about automation often pit new technologies against workers. The introduction of advanced machine tools, industrial robots, and AI have all been met with concern that technological progress will mean fewer jobs. However, workers themselves offer a more optimistic, nuanced perspective. Drawing on a far-reaching 2024 survey of more than 9,000 workers across nine countries, this paper finds that more workers report potential benefits from new technologies like robots and AI for their safety and comfort at work, their pay, and their autonomy on the job than report potential costs. Workers with jobs that ask them to solve complex problems, workers who feel valued by their employers, and workers who are motivated to move up in their careers are all more likely to see new technologies as beneficial. In contrast to assumptions in previous research, more formal education is in some cases associated with more negative attitudes toward automation and its impact on work. In an experimental setting, the prospect of financial incentives for workers improve their perceptions of automation technologies, whereas the prospect of increased input about how new technologies are used does not have a significant effect on workers' attitudes toward automation.
- Published
- 2024
35. Coupled-Cluster Calculations of Infinite Nuclear Matter in the Complete Basis Limit Using Bayesian Machine Learning
- Author
-
Butler, Julie, Hjorth-Jensen, Morten, and Jansen, Gustav R.
- Subjects
Nuclear Theory - Abstract
Infinite nuclear matter provides valuable insights into the behavior of nuclear systems and aids our understanding of atomic nuclei and large-scale stellar objects such as neutron stars. However, partly due to the large basis needed to converge the system's binding energy, size-extensive methods such as coupled-cluster theory struggle with long computational run times, even using the nation's largest high-performance computing facilities. This research introduces a novel approach to the problem. We propose using a machine learning method to predict the coupled-cluster energies of infinite matter systems in the complete basis limit, leveraging only data collected using smaller basis sets. This method promises to deliver high-accuracy results with significantly reduced run times. The sequential regression extrapolation (SRE) algorithm, based on Gaussian processes, was created to perform these extrapolations. By combining Bayesian machine learning with a unique method of formatting the training data, we can create a powerful extrapolator that can make accurate predictions given very little data. The SRE algorithm successfully predicted the CCD(T) energies for pure neutron matter across six densities near nuclear saturation density, with an average error of 0.0083 MeV/N. The algorithm achieved an average error of 0.038 MeV/A for symmetric nuclear matter. These predictions were made with a time savings of 83.8 node hours for pure neutron matter and 284 node hours for symmetric nuclear matter. Additionally, the symmetry energy at these six densities was predicted with an average error of 0.031 MeV/A and a total time savings of 368 node hours compared to the traditional converged coupled-cluster calculations performed without the SRE algorithm.
- Published
- 2024
36. The ESO SupJup Survey III: Confirmation of 13CO in YSES 1 b and Atmospheric Detection of YSES 1 c with CRIRES+
- Author
-
Zhang, Yapeng, Picos, Darío González, de Regt, Sam, Snellen, Ignas A. G., Gandhi, Siddharth, Ginski, Christian, Kesseli, Aurora Y., Landman, Rico, Mollière, Paul, Nasedkin, Evert, Sánchez-López, Alejandro, Stolker, Tomas, Inglis, Julie, Knutson, Heather A., Mawet, Dimitri, Wallack, Nicole, and Xuan, Jerry W.
- Subjects
Astrophysics - Earth and Planetary Astrophysics ,Astrophysics - Solar and Stellar Astrophysics - Abstract
High-resolution spectroscopic characterization of young super-Jovian planets enables precise constraints on elemental and isotopic abundances of their atmospheres. As part of the ESO SupJup Survey, we present high-resolution spectral observations of two wide-orbit super-Jupiters in YSES 1 (or TYC 8998-760-1) using the upgraded VLT/CRIRES+ (R~100,000) in K-band. We carry out free atmospheric retrieval analyses to constrain chemical and isotopic abundances, temperature structures, rotation velocities, and radial velocities. We confirm the previous detection of 13CO in YSES 1 b at a higher significance of 12.6{\sigma}, but point to a higher 12CO/13CO ratio of 88+/-13 (1{\sigma} confidence interval), consistent with the primary's isotope ratio 66+/-5. We retrieve a solar-like composition in YSES 1 b with a C/O=0.57+/-0.01, indicating a formation via gravitational instability or core accretion beyond the CO iceline. Additionally, the observations lead to detections of H2O and CO in the outer planet YSES 1 c at 7.3{\sigma} and 5.7{\sigma}, respectively. We constrain the atmospheric C/O ratio of YSES 1 c to be either solar or subsolar (C/O=0.36+/-0.15), indicating the accretion of oxygen-rich solids. The two companions have distinct vsini, 5.34+/-0.14 km/s for YSES 1 b and 11.3+/-2.1 km/s for YSES 1 c, despite their similar natal environments. This may indicate different spin axis inclinations or effective magnetic braking by the long-lived circumplanetary disk around YSES 1 b. YSES 1 represents an intriguing system for comparative studies of super-Jovian companions and linking present atmospheres to formation histories., Comment: 25 pages, 11 figure, accepted for publication in AJ. The extracted CRIRES+ spectra of the YSES-1 system can be found at https://doi.org/10.5281/zenodo.13664032
- Published
- 2024
- Full Text
- View/download PDF
37. Automated Spatio-Temporal Weather Modeling for Load Forecasting
- Author
-
Keisler, Julie and Bregere, Margaux
- Subjects
Computer Science - Machine Learning ,Computer Science - Artificial Intelligence ,Statistics - Machine Learning - Abstract
Electricity is difficult to store, except at prohibitive cost, and therefore the balance between generation and load must be maintained at all times. Electricity is traditionally managed by anticipating demand and intermittent production (wind, solar) and matching flexible production (hydro, nuclear, coal and gas). Accurate forecasting of electricity load and renewable production is therefore essential to ensure grid performance and stability. Both are highly dependent on meteorological variables (temperature, wind, sunshine). These dependencies are complex and difficult to model. On the one hand, spatial variations do not have a uniform impact because population, industry, and wind and solar farms are not evenly distributed across the territory. On the other hand, temporal variations can have delayed effects on load (due to the thermal inertia of buildings). With access to observations from different weather stations and simulated data from meteorological models, we believe that both phenomena can be modeled together. In today's state-of-the-art load forecasting models, the spatio-temporal modeling of the weather is fixed. In this work, we aim to take advantage of the automated representation and spatio-temporal feature extraction capabilities of deep neural networks to improve spatio-temporal weather modeling for load forecasting. We compare our deep learning-based methodology with the state-of-the-art on French national load. This methodology could also be fully adapted to forecasting renewable energy production.
- Published
- 2024
38. Spectral invariants of integrable polygons
- Author
-
Mårdby, Gustav and Rowlett, Julie
- Subjects
Mathematics - Spectral Theory ,Mathematical Physics ,Mathematics - Number Theory ,35P15, 58J35, 11M36, 53C22 - Abstract
An integrable polygon is one whose interior angles are fractions of $\pi$; that is to say of the form $\frac \pi n$ for positive integers $n$. We consider the Laplace spectrum on these polygons with the Dirichlet and Neumann boundary conditions, and we obtain new spectral invariants for these polygons. This includes new expressions for the spectral zeta function and zeta-regularized determinant as well as a new spectral invariant contained in the short-time asymptotic expansion of the heat trace. Moreover, we demonstrate relationships between the short-time heat trace invariants of general polygonal domains (not necessarily integrable) and smoothly bounded domains and pose conjectures and further related directions of investigation., Comment: 33 pages, 4 figures
- Published
- 2024
39. Improving constraints on the extended mass distribution in the Galactic Center with stellar orbits
- Author
-
The GRAVITY Collaboration, Dayem, Karim Abd El, Abuter, Roberto, Aimar, Nicolas, Seoane, Pau Amaro, Amorim, Antonio, Beck, Julie, Berger, Jean Philippe, Bonnet, Henri, Bourdarot, Guillaume, Brandner, Wolfgang, Cardoso, Vitor, Dolcetta, Roberto Capuzzo, Clénet, Yann, Davies, Ric, de Zeeuw, Tim, Drescher, Antonia, Eckart, Andreas, Eisenhauer, Frank, Feuchtgruber, Helmut, Finger, Gert, Schreiber, Natascha M. Förster, Foschi, Arianna, Gao, Feng, Garcia, Paulo, Gendron, Eric, Genzel, Reinhard, Gillessen, Stefan, Hartl, Michael, Haubois, Xavier, Haussman, Frank, Heißel, Gernot, Hennig, Thomas, Hippler, Stefan, Horrobin, Matthew, Jochum, Lieselotte, Jocou, Laurent, Kaufer, Andreas, Kervella, Pierre, Lacour, Sylvestre, Lapeyrère, Vincent, Bouquin, Jean B. Le, Léna, Pierre, Lutz, Dieter, Mang, Felix, More, Nikhil, Ott, Thomas, Paumard, Thibaut, Perraut, Karine, Perrin, Guy, Pfuhl, Oliver, Rabien, Sebastien, Ribeiro, Diogo C., Bordoni, Matteo Sadun, Scheithauer, Silvia, Shangguan, Jinyi, Shimizu, Taro, Stadler, Julia, Straub, Odele, Straubmeier, Christian, Sturm, Eckhard, Tacconi, Linda J., Urso, Irene, Vincent, Frederic, Von Fellenberg, Sebastiano D., Widmann, Felix, Wieprecht, Ekkehard, Woillez, Julien, and Zhang, Fupeng
- Subjects
Astrophysics - Astrophysics of Galaxies ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
Studying the orbital motion of stars around Sagittarius A* in the Galactic Center provides a unique opportunity to probe the gravitational potential near the supermassive black hole at the heart of our Galaxy. Interferometric data obtained with the GRAVITY instrument at the Very Large Telescope Interferometer (VLTI) since 2016 has allowed us to achieve unprecedented precision in tracking the orbits of these stars. GRAVITY data have been key to detecting the in-plane, prograde Schwarzschild precession of the orbit of the star S2, as predicted by General Relativity. By combining astrometric and spectroscopic data from multiple stars, including S2, S29, S38, and S55 - for which we have data around their time of pericenter passage with GRAVITY - we can now strengthen the significance of this detection to an approximately $10 \sigma$ confidence level. The prograde precession of S2's orbit provides valuable insights into the potential presence of an extended mass distribution surrounding Sagittarius A*, which could consist of a dynamically relaxed stellar cusp comprised of old stars and stellar remnants, along with a possible dark matter spike. Our analysis, based on two plausible density profiles - a power-law and a Plummer profile - constrains the enclosed mass within the orbit of S2 to be consistent with zero, establishing an upper limit of approximately $1200 \, M_\odot$ with a $1 \sigma$ confidence level. This significantly improves our constraints on the mass distribution in the Galactic Center. Our upper limit is very close to the expected value from numerical simulations for a stellar cusp in the Galactic Center, leaving little room for a significant enhancement of dark matter density near Sagittarius A*., Comment: Submitted to A&A on September 17, 2024
- Published
- 2024
40. Sparse Factor Analysis for Categorical Data with the Group-Sparse Generalized Singular Value Decomposition
- Author
-
Yu, Ju-Chi, Borgne, Julie Le, Krishnan, Anjali, Gloaguen, Arnaud, Yang, Cheng-Ta, Rabin, Laura A, Abdi, Hervé, and Guillemot, Vincent
- Subjects
Mathematics - Statistics Theory - Abstract
Correspondence analysis, multiple correspondence analysis and their discriminant counterparts (i.e., discriminant simple correspondence analysis and discriminant multiple correspondence analysis) are methods of choice for analyzing multivariate categorical data. In these methods, variables are integrated into optimal components computed as linear combinations whose weights are obtained from a generalized singular value decomposition (GSVD) that integrates specific metric constraints on the rows and columns of the original data matrix. The weights of the linear combinations are, in turn, used to interpret the components, and this interpretation is facilitated when components are 1) pairwise orthogonal and 2) when the values of the weights are either large or small but not intermediate-a pattern called a simple or a sparse structure. To obtain such simple configurations, the optimization problem solved by the GSVD is extended to include new constraints that implement component orthogonality and sparse weights. Because multiple correspondence analysis represents qualitative variables by a set of binary variables, an additional group constraint is added to the optimization problem in order to sparsify the whole set representing one qualitative variable. This new algorithm-called group-sparse GSVD (gsGSVD)-integrates these constraints via an iterative projection scheme onto the intersection of subspaces where each subspace implements a specific constraint. In this paper, we expose this new algorithm and show how it can be adapted to the sparsification of simple and multiple correspondence analysis, and illustrate its applications with the analysis of four different data sets-each illustrating the sparsification of a particular CA-based analysis.
- Published
- 2024
41. Photothermal Spectroscopy for Planetary Sciences: Mid-IR Absorption Made Easy
- Author
-
Cox, Christopher, Haynes, Jakob, Duffey, Christopher, Bennett, Christopher, and Brisset, Julie
- Subjects
Astrophysics - Earth and Planetary Astrophysics ,Astrophysics - Instrumentation and Methods for Astrophysics - Abstract
The understanding of the formation and evolution of the solar system still has many unanswered questions. Formation of solids in the solar system, mineral and organic mixing, and planetary body creation are all topics of interest to the community. Studying these phenomena is often performed through observations, remote sensing, and in-situ analysis, but there are limitations to the methods. Limitations such as IR diffraction limits, spatial resolution issues, and spectral resolution issues can prevent detection of organics, detection and identification of cellular structures, and the disentangling of granular mixtures. Optical-PhotoThermal InfraRed (O-PTIR) spectroscopy is a relatively new method of spectroscopy currently used in fields other than planetary sciences. O-PTIR is a non-destructive, highly repeatable, and fast form of measurement capable of reducing these limitations. Using a dual laser system with an IR source tuned to the mid-IR wavelength we performed laboratory O-PTIR measurements to compare O-PTIR data to existing IR absorption data and laboratory FTIR measurements for planetary materials. We do this for the purpose of introducing O-PTIR to the planetary science community. The technique featured here would serve to better measurements of planetary bodies during in-situ analysis. We find that, unlike other fields where O-PTIR produces almost one-to-one measurements with IR absorption measurements of the same material, granular materials relevant to planetary science do not. However, we do find that the materials compared were significantly close and O-PTIR was still capable of identifying materials relevant to planetary science., Comment: This paper is an introductory of O-PTIR spectroscopy into planetary science. It is also going to be part 1 of a series. This is a pre-print
- Published
- 2024
42. Harnessing AI data-driven global weather models for climate attribution: An analysis of the 2017 Oroville Dam extreme atmospheric river
- Author
-
Baño-Medina, Jorge, Sengupta, Agniv, Michaelis, Allison, Monache, Luca Delle, Kalansky, Julie, and Watson-Parris, Duncan
- Subjects
Physics - Atmospheric and Oceanic Physics ,Computer Science - Artificial Intelligence - Abstract
AI data-driven models (Graphcast, Pangu Weather, Fourcastnet, and SFNO) are explored for storyline-based climate attribution due to their short inference times, which can accelerate the number of events studied, and provide real time attributions when public attention is heightened. The analysis is framed on the extreme atmospheric river episode of February 2017 that contributed to the Oroville dam spillway incident in Northern California. Past and future simulations are generated by perturbing the initial conditions with the pre-industrial and the late-21st century temperature climate change signals, respectively. The simulations are compared to results from a dynamical model which represents plausible pseudo-realities under both climate environments. Overall, the AI models show promising results, projecting a 5-6 % increase in the integrated water vapor over the Oroville dam in the present day compared to the pre-industrial, in agreement with the dynamical model. Different geopotential-moisture-temperature dependencies are unveiled for each of the AI-models tested, providing valuable information for understanding the physicality of the attribution response. However, the AI models tend to simulate weaker attribution values than the pseudo-reality imagined by the dynamical model, suggesting some reduced extrapolation skill, especially for the late-21st century regime. Large ensembles generated with an AI model (>500 members) produced statistically significant present-day to pre-industrial attribution results, unlike the >20-member ensemble from the dynamical model. This analysis highlights the potential of AI models to conduct attribution analysis, while emphasizing future lines of work on explainable artificial intelligence to gain confidence in these tools, which can enable reliable attribution studies in real-time., Comment: This Work has been submitted to Artificial Intelligence for the Earth Systems
- Published
- 2024
43. Self-Contrastive Forward-Forward Algorithm
- Author
-
Chen, Xing, Liu, Dongshu, Laydevant, Jeremie, and Grollier, Julie
- Subjects
Computer Science - Machine Learning ,Computer Science - Artificial Intelligence ,Computer Science - Computer Vision and Pattern Recognition ,Computer Science - Emerging Technologies ,Computer Science - Neural and Evolutionary Computing - Abstract
The Forward-Forward (FF) algorithm is a recent, purely forward-mode learning method, that updates weights locally and layer-wise and supports supervised as well as unsupervised learning. These features make it ideal for applications such as brain-inspired learning, low-power hardware neural networks, and distributed learning in large models. However, while FF has shown promise on written digit recognition tasks, its performance on natural images and time-series remains a challenge. A key limitation is the need to generate high-quality negative examples for contrastive learning, especially in unsupervised tasks, where versatile solutions are currently lacking. To address this, we introduce the Self-Contrastive Forward-Forward (SCFF) method, inspired by self-supervised contrastive learning. SCFF generates positive and negative examples applicable across different datasets, surpassing existing local forward algorithms for unsupervised classification accuracy on MNIST (MLP: 98.7%), CIFAR-10 (CNN: 80.75%), and STL-10 (CNN: 77.3%). Additionally, SCFF is the first to enable FF training of recurrent neural networks, opening the door to more complex tasks and continuous-time video and text processing.
- Published
- 2024
44. Quartz Clouds in the Dayside Atmosphere of the Quintessential Hot Jupiter HD 189733 b
- Author
-
Inglis, Julie, Batalha, Natasha E., Lewis, Nikole K., Kataria, Tiffany, Knutson, Heather A., Kilpatrick, Brian M., Gagnebin, Anna, Mukherjee, Sagnick, Pettyjohn, Maria M., Crossfield, Ian J. M., Foote, Trevor O., Grant, David, Henry, Gregory W., Lally, Maura, McKemmish, Laura K., Sing, David K., Wakeford, Hannah R., Trujillo, Juan C. Zapata, and Zellem, Robert T.
- Subjects
Astrophysics - Earth and Planetary Astrophysics - Abstract
Recent mid-infrared observations with JWST/MIRI have resulted in the first direct detections of absorption features from silicate clouds in the transmission spectra of two transiting exoplanets, WASP-17 b and WASP-107 b. In this paper, we measure the mid-infrared ($5-12$ $\mu$m) dayside emission spectrum of the benchmark hot Jupiter HD 189733 b with MIRI LRS by combining data from two secondary eclipse observations. We confirm the previous detection of H$_2$O absorption at 6.5 $\mu$m from Spitzer/IRS and additionally detect H$_2$S as well as an absorption feature at 8.7 $\mu$m in both secondary eclipse observations. The excess absorption at 8.7 $\mu$m can be explained by the presence of small ($\sim$0.01 $\mu$m) grains of SiO$_2$[s] in the uppermost layers of HD 189733 b's dayside atmosphere. This is the first direct detection of silicate clouds in HD 189733 b's atmosphere, and the first detection of a distinct absorption feature from silicate clouds on the day side of any hot Jupiter. We find that models including SiO$_2$[s] are preferred by $6-7\sigma$ over clear models and those with other potential cloud species. The high altitude location of these silicate particles is best explained by formation in the hottest regions of HD 189733 b's dayside atmosphere near the substellar point. We additionally find that HD 189733 b's emission spectrum longward of 9 $\mu$m displays residual features not well captured by our current atmospheric models. When combined with other JWST observations of HD 189733 b's transmission and emission spectrum at shorter wavelengths, these observations will provide us with the most detailed picture to date of the atmospheric composition and cloud properties of this benchmark hot Jupiter., Comment: 21 pages, 7 Figures, 3 Tables, Accepted to ApJL
- Published
- 2024
- Full Text
- View/download PDF
45. HPC with Enhanced User Separation
- Author
-
Prout, Andrew, Reuther, Albert, Houle, Michael, Jones, Michael, Michaleas, Peter, Anderson, LaToya, Arcand, William, Bergeron, Bill, Bestor, David, Bonn, Alex, Burrill, Daniel, Byun, Chansup, Gadepally, Vijay, Hubbell, Matthew, Jananthan, Hayden, Luszczek, Piotr, Milechin, Lauren, Morales, Guillermo, Mullen, Julie, Rosa, Antonio, Yee, Charles, and Kepner, Jeremy
- Subjects
Computer Science - Distributed, Parallel, and Cluster Computing - Abstract
HPC systems used for research run a wide variety of software and workflows. This software is often written or modified by users to meet the needs of their research projects, and rarely is built with security in mind. In this paper we explore several of the key techniques that MIT Lincoln Laboratory Supercomputing Center has deployed on its systems to manage the security implications of these workflows by providing enforced separation for processes, filesystem access, network traffic, and accelerators to make every user feel like they are running on a personal HPC.
- Published
- 2024
46. Deconvolving X-ray Galaxy Cluster Spectra Using a Recurrent Inference Machine
- Author
-
Rhea, Carter, Hlavacek-Larrondo, Julie, Adam, Alexandre, Kraft, Ralph, Bogdan, Akos, Perreault-Levasseur, Laurence, and Prunier, Marine
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
Recent advances in machine learning algorithms have unlocked new insights in observational astronomy by allowing astronomers to probe new frontiers. In this article, we present a methodology to disentangle the intrinsic X-ray spectrum of galaxy clusters from the instrumental response function. Employing state-of-the-art modeling software and data mining techniques of the Chandra data archive, we construct a set of 100,000 mock Chandra spectra. We train a recurrent inference machine (RIM) to take in the instrumental response and mock observation and output the intrinsic X-ray spectrum. The RIM can recover the mock intrinsic spectrum below the 1-$\sigma$ error threshold; moreover, the RIM reconstruction of the mock observations are indistinguishable from the observations themselves. To further test the algorithm, we deconvolve extracted spectra from the central regions of the galaxy group NGC 1550, known to have a rich X-ray spectrum, and the massive galaxy clusters Abell 1795. Despite the RIM reconstructions consistently remaining below the 1-$\sigma$ noise level, the recovered intrinsic spectra did not align with modeled expectations. This discrepancy is likely attributable to the RIM's method of implicitly encoding prior information within the neural network. This approach holds promise for unlocking new possibilities in accurate spectral reconstructions and advancing our understanding of complex X-ray cosmic phenomena., Comment: Submitted to AJ
- Published
- 2024
47. Adaptive Language-Guided Abstraction from Contrastive Explanations
- Author
-
Peng, Andi, Li, Belinda Z., Sucholutsky, Ilia, Kumar, Nishanth, Shah, Julie A., Andreas, Jacob, and Bobu, Andreea
- Subjects
Computer Science - Robotics ,Computer Science - Machine Learning - Abstract
Many approaches to robot learning begin by inferring a reward function from a set of human demonstrations. To learn a good reward, it is necessary to determine which features of the environment are relevant before determining how these features should be used to compute reward. End-to-end methods for joint feature and reward learning (e.g., using deep networks or program synthesis techniques) often yield brittle reward functions that are sensitive to spurious state features. By contrast, humans can often generalizably learn from a small number of demonstrations by incorporating strong priors about what features of a demonstration are likely meaningful for a task of interest. How do we build robots that leverage this kind of background knowledge when learning from new demonstrations? This paper describes a method named ALGAE (Adaptive Language-Guided Abstraction from [Contrastive] Explanations) which alternates between using language models to iteratively identify human-meaningful features needed to explain demonstrated behavior, then standard inverse reinforcement learning techniques to assign weights to these features. Experiments across a variety of both simulated and real-world robot environments show that ALGAE learns generalizable reward functions defined on interpretable features using only small numbers of demonstrations. Importantly, ALGAE can recognize when features are missing, then extract and define those features without any human input -- making it possible to quickly and efficiently acquire rich representations of user behavior., Comment: CoRL 2024
- Published
- 2024
48. Anonymized Network Sensing Graph Challenge
- Author
-
Jananthan, Hayden, Jones, Michael, Arcand, William, Bestor, David, Bergeron, William, Burrill, Daniel, Buluc, Aydin, Byun, Chansup, Davis, Timothy, Gadepally, Vijay, Grant, Daniel, Houle, Michael, Hubbell, Matthew, Luszczek, Piotr, Michaleas, Peter, Milechin, Lauren, Milner, Chasen, Morales, Guillermo, Morris, Andrew, Mullen, Julie, Patel, Ritesh, Pentland, Alex, Pisharody, Sandeep, Prout, Andrew, Reuther, Albert, Rosa, Antonio, Wachman, Gabriel, Yee, Charles, and Kepner, Jeremy
- Subjects
Computer Science - Networking and Internet Architecture ,Computer Science - Discrete Mathematics ,Computer Science - Performance ,Computer Science - Software Engineering ,Mathematics - Combinatorics - Abstract
The MIT/IEEE/Amazon GraphChallenge encourages community approaches to developing new solutions for analyzing graphs and sparse data derived from social media, sensor feeds, and scientific data to discover relationships between events as they unfold in the field. The anonymized network sensing Graph Challenge seeks to enable large, open, community-based approaches to protecting networks. Many large-scale networking problems can only be solved with community access to very broad data sets with the highest regard for privacy and strong community buy-in. Such approaches often require community-based data sharing. In the broader networking community (commercial, federal, and academia) anonymized source-to-destination traffic matrices with standard data sharing agreements have emerged as a data product that can meet many of these requirements. This challenge provides an opportunity to highlight novel approaches for optimizing the construction and analysis of anonymized traffic matrices using over 100 billion network packets derived from the largest Internet telescope in the world (CAIDA). This challenge specifies the anonymization, construction, and analysis of these traffic matrices. A GraphBLAS reference implementation is provided, but the use of GraphBLAS is not required in this Graph Challenge. As with prior Graph Challenges the goal is to provide a well-defined context for demonstrating innovation. Graph Challenge participants are free to select (with accompanying explanation) the Graph Challenge elements that are appropriate for highlighting their innovations., Comment: Accepted to IEEE HPEC 2024
- Published
- 2024
49. Evaluation of South African Candidate Sites for an Expanded Event Horizon Telescope
- Author
-
Simelane, Senkhosi, Deane, Roger, Kemball, Athol, Botha, Roelf, Julie, Roufurd, Molamu, Keitumetse, Tiplady, Adrian, and de Witt, Aletha
- Subjects
Astrophysics - Instrumentation and Methods for Astrophysics - Abstract
Global expansion of the Event Horizon Telescope (EHT) will see the strategic addition of antennas at new geographical locations, transforming the sensitivity and imaging fidelity of the $\lambda \sim 1\,$mm EHT array. A possible South African EHT station would leverage a strong geographical advantage, local infrastructure, and radio astronomy expertise, and have strong synergies with the Africa Millimetre Telescope in Namibia. We assessed three South African candidate millimetre sites using climatological simulations and found at least two promising sites. These sites are comparable to some existing EHT stations during the typical April EHT observing window and outperform them during most of the year, especially the southern hemisphere winter. Interferometric simulations of Africa-enhanced EHT arrays under the simulated atmospheric conditions demonstrate the improved array performance. In typical weather, the number of reliable visibility detections increased considerably, especially at $(u, v)$-distances corresponding to the angular sizes of the Sagittarius A$^*$ and Messier 87$^*$ black hole shadow diameters ($\sim40\,\mathrm{\mu}$as to $50\,\mathrm{\mu}$as). The simulation results underscore the sizable, positive impact of a strategically placed South African EHT station on ngEHT objectives and the resulting black hole science., Comment: 6 pages, 3 figures, 1 table. Submitted to URSI RSL
- Published
- 2024
50. Enhancing Preference-based Linear Bandits via Human Response Time
- Author
-
Li, Shen, Zhang, Yuyang, Ren, Zhaolin, Liang, Claire, Li, Na, and Shah, Julie A.
- Subjects
Computer Science - Machine Learning ,Computer Science - Artificial Intelligence ,Computer Science - Human-Computer Interaction ,Economics - Econometrics ,Statistics - Machine Learning - Abstract
Binary human choice feedback is widely used in interactive preference learning for its simplicity, but it provides limited information about preference strength. To overcome this limitation, we leverage human response times, which inversely correlate with preference strength, as complementary information. Our work integrates the EZ-diffusion model, which jointly models human choices and response times, into preference-based linear bandits. We introduce a computationally efficient utility estimator that reformulates the utility estimation problem using both choices and response times as a linear regression problem. Theoretical and empirical comparisons with traditional choice-only estimators reveal that for queries with strong preferences ("easy" queries), choices alone provide limited information, while response times offer valuable complementary information about preference strength. As a result, incorporating response times makes easy queries more useful. We demonstrate this advantage in the fixed-budget best-arm identification problem, with simulations based on three real-world datasets, consistently showing accelerated learning when response times are incorporated.
- Published
- 2024
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.