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Subsurface Contaminants Focus Area (SCFA) Lead Laboratory Providing Technical Assistance to the DOE Weapons Complex in Subsurface Contamination
The Subsurface Contaminants Focus Area (SCFA), a DOE-HQ EM-50 organization, is hosted and managed at the Savannah River Site in Aiken, South Carolina. SCFA is an integrated program chartered to find technology and scientific solutions to address DOE subsurface environmental restoration problems throughout the DOE Weapons Complex. Since its inception in 1989, the SCFA program has resulted in a total of 269 deployments of 83 innovative technologies. Until recently, the primary thrust of the program has been to develop, demonstrate, and deploy those remediation technology alternatives that are solutions to technology needs identified by the DOE Sites. Over the last several years, the DOE Sites began to express a need not only for innovative technologies, but also for technical assistance. In response to this need, DOE-HQ EM-50, in collaboration with and in support of a Strategic Lab Council recommendation directed each of its Focus Areas to implement a Lead Laboratory Concept to enhance their technical capabilities. Because each Focus Area is unique as defined by the contrast in either the type of contaminants involved or the environments in which they are found, the Focus Areas were given latitude in how they set up and implemented the Lead Lab Concept. The configuration of choice for the SCFA was a Lead-Partner Lab arrangement. Savannah River Technology Center (SRTC) teamed with the SCFA as the Focus Area's Lead Laboratory. SRTC then partnered with the DOE National Laboratories to create a virtual consulting function within DOE. The National Laboratories were established to help solve the Nation's most difficult problems, drawing from a resource pool of the most talented and gifted scientists and engineers. Following that logic, SRTC, through the Lead-Partner Lab arrangement, has that same resource base to draw from to provide assistance to any SCFA DOE customer throughout the Complex. This paper briefly describes how this particular arrangement is organized and provides case histories that illustrate its strengths in solving problems and offering solutions. The program is designed to minimize red tape, maximize value, and to rapidly and cost effectively disseminate solutions to common problems facing the DOE
Outcome of revision anterior cruciate ligament reconstruction: a systematic review
BACKGROUND: Revision anterior cruciate ligament (ACL) reconstruction is believed to have an inferior outcome compared with primary ACL reconstruction. The available literature on the outcome of revision ACL reconstruction is sparse compared with that for primary reconstruction. The purpose of this systematic review was to test the hypothesis that the outcome of revision ACL reconstruction compares unfavorably with the historical outcome of primary ACL reconstruction. METHODS: A systematic review of studies evaluating the outcome of revision ACL reconstructions with a minimum of two years of follow-up was performed. Pooled data were collected when appropriate and a mixed-effect-model meta-analysis was performed for important outcome measures that were reported in several studies (objective graft failure, Lysholm score, International Knee Documentation Committee [IKDC] subjective score, and IKDC objective score). Objective failure was defined as repeat revision, a side-to-side difference of >5 mm measured with use of a KT1000 arthrometer, or a pivot-shift grade of 2+ or 3+. RESULTS: Twenty-one studies were included, and 863 of the 1004 patients in these studies had a minimum of two years of follow-up and were analyzed. The pooled mean age of the patients at the time of the revision procedure was 30.6 years, and 66% were male. Objective failure occurred in 13.7% ± 2.7% of the patients (95% confidence interval, 8.0% to 19.4%). The mean Lysholm score in 491 patients was 82.1 ± 3.3 (95% confidence interval, 74.6 to 89.5) according to a mixed-model meta-analysis. The mean IKDC subjective score in 202 patients was 74.8 ± 4.4 (95% confidence interval, 62.5 to 87.0). CONCLUSIONS: Revision ACL reconstruction resulted in a worse outcome compared with primary ACL reconstruction. Patient-reported outcome scores were inferior to previously published results of primary ACL reconstruction, but these differences may not be clinically important. A dramatically elevated failure rate was noted after revision ACL reconstruction; this rate was nearly three to four times the failure rate in prospective series of primary ACL reconstructions
Persistent starspot signals on M dwarfs: multi-wavelength Doppler observations with the Habitable-zone Planet Finder and Keck/HIRES
Young, rapidly-rotating M dwarfs exhibit prominent starspots, which create
quasiperiodic signals in their photometric and Doppler spectroscopic
measurements. The periodic Doppler signals can mimic radial velocity (RV)
changes expected from orbiting exoplanets. Exoplanets can be distinguished from
activity-induced false positives by the chromaticity and long-term incoherence
of starspot signals, but these qualities are poorly constrained for
fully-convective M stars. Coherent photometric starspot signals on M dwarfs may
persist for hundreds of rotations, and the wavelength dependence of starspot RV
signals may not be consistent between stars due to differences in their
magnetic fields and active regions. We obtained precise multi-wavelength RVs of
four rapidly-rotating M dwarfs (AD Leo, G 227-22, GJ 1245B, GJ 3959) using the
near-infrared (NIR) Habitable-zone Planet Finder, and the optical Keck/HIRES
spectrometer. Our RVs are complemented by photometry from Kepler, TESS, and the
Las Cumbres Observatory (LCO) network of telescopes. We found that all four
stars exhibit large spot-induced Doppler signals at their rotation periods, and
investigated the longevity and optical-to-NIR chromaticity for these signals.
The phase curves remain coherent much longer than is typical for Sunlike stars.
Their chromaticity varies, and one star (GJ 3959) exhibits optical and NIR RV
modulation consistent in both phase and amplitude. In general, though, we find
that the NIR amplitudes are lower than their optical counterparts. We conclude
that starspot modulation for rapidly-rotating M stars frequently remains
coherent for hundreds of stellar rotations, and gives rise to Doppler signals
that, due to this coherence, may be mistaken for exoplanets.Comment: Accepted for publication in the Astrophysical Journa
A line confusion limited millimeter survey of Orion KL (I): sulfur carbon chains
We perform a sensitive (line confusion limited), single-side band spectral
survey towards Orion KL with the IRAM 30m telescope, covering the following
frequency ranges: 80-115.5 GHz, 130-178 GHz, and 197-281 GHz. We detect more
than 14 400 spectral features of which 10 040 have been identified up to date
and attributed to 43 different molecules, including 148 isotopologues and lines
from vibrationally excited states. In this paper, we focus on the study of OCS,
HCS+, H2CS, CS, CCS, C3S, and their isotopologues. In addition, we map the OCS
J=18-17 line and complete complementary observations of several OCS lines at
selected positions around Orion IRc2 (the position selected for the survey). We
report the first detection of OCS v2 = 1 and v3 = 1 vibrationally excited
states in space and the first detection of C3S in warm clouds. Most of CCS, and
almost all C3S, line emission arises from the hot core indicating an
enhancement of their abundances in warm and dense gas. Column densities and
isotopic ratios have been calculated using a large velocity gradient (LVG)
excitation and radiative transfer code (for the low density gas components) and
a local thermal equilibrium (LTE) code (appropriate for the warm and dense hot
core component), which takes into account the different cloud components known
to exist towards Orion KL, the extended ridge, compact ridge, plateau, and hot
core. The vibrational temperature derived from OCS v2 = 1 and v3 = 1 levels is
about 210 K, similar to the gas kinetic temperature in the hot core. These OCS
high energy levels are probably pumped by absorption of IR dust photons. We
derive an upper limit to the OC3S, H2CCS, HNCS, HOCS+, and NCS column
densities. Finally, we discuss the D/H abundance ratio and infer the following
isotopic abundances: 12C/13C=45+-20, 32S/34S=20+-6, 32S/33S=75+-29, and
16O/18O=250+-135.Comment: Accepted for publication in A&
TOI-1670 c, a 40-day Orbital Period Warm Jupiter in a Compact System, is Well-aligned
We report the measurement of the sky-projected obliquity angle of
the Warm Jovian exoplanet TOI-1670 c via the Rossiter-McLaughlin effect as part
of the Stellar Obliquities in Long-period Exoplanet Systems (SOLES) project. We
observed the transit window during UT 20 April 2023 for 7 continuous hours with
NEID on the 3.5 m WIYN Telescope at Kitt Peak National Observatory. TOI-1670
hosts a sub-Neptune (P ~11 days; planet b) interior to the Warm Jovian (P ~40
days; planet c), which presents an opportunity to investigate the dynamics of a
Warm Jupiter with an inner companion. Additionally, TOI-1670 c is now among the
longest-period planets to date to have its sky-projected obliquity angle
measured. We find planet c is well-aligned to the host star, with =
-0.3 +/- 2.2 degrees. TOI-1670 c joins a growing census of aligned Warm
Jupiters around single stars and aligned planets in multi-planet systems.Comment: 11 pages, 2 figures, 1 table. Accepted to ApJ Letter
Persistent Starspot Signals on M Dwarfs: Multiwavelength Doppler Observations with the Habitable-zone Planet Finder and Keck/HIRES
Young, rapidly rotating M dwarfs exhibit prominent starspots, which create quasiperiodic signals in their photometric and Doppler spectroscopic measurements. The periodic Doppler signals can mimic radial velocity (RV) changes expected from orbiting exoplanets. Exoplanets can be distinguished from activity-induced false positives by the chromaticity and long-term incoherence of starspot signals, but these qualities are poorly constrained for fully convective M stars. Coherent photometric starspot signals on M dwarfs may persist for hundreds of rotations, and the wavelength dependence of starspot RV signals may not be consistent between stars due to differences in their magnetic fields and active regions. We obtained precise multiwavelength RVs of four rapidly rotating M dwarfs (AD Leo, G227-22, GJ 1245B, GJ 3959) using the near-infrared (NIR) Habitable-zone Planet Finder and the optical Keck/HIRES spectrometer. Our RVs are complemented by photometry from Kepler, TESS, and the Las Cumbres Observatory network of telescopes. We found that all four stars exhibit large spot-induced Doppler signals at their rotation periods, and investigated the longevity and optical-to-NIR chromaticity for these signals. The phase curves remain coherent much longer than is typical for Sunlike stars. Their chromaticity varies, and one star (GJ 3959) exhibits optical and NIR RV modulation consistent in both phase and amplitude. In general, though, we find that the NIR amplitudes are lower than their optical counterparts. We conclude that starspot modulation for rapidly rotating M stars frequently remains coherent for hundreds of stellar rotations and gives rise to Doppler signals that, due to this coherence, may be mistaken for exoplanets
Early human impacts and ecosystem reorganization in southern-central Africa
Modern Homo sapiens engage in substantial ecosystem modification, but it is difficult to detect the origins or early consequences of these behaviors. Archaeological, geochronological, geomorphological, and paleoenvironmental data from northern Malawi document a changing relationship between forager presence, ecosystem organization, and alluvial fan formation in the Late Pleistocene. Dense concentrations of Middle Stone Age artifacts and alluvial fan systems formed after ca. 92 thousand years ago, within a paleoecological context with no analog in the preceding half-million-year record. Archaeological data and principal coordinates analysis indicate that early anthropogenic fire relaxed seasonal constraints on ignitions, influencing vegetation composition and erosion. This operated in tandem with climate-driven changes in precipitation to culminate in an ecological transition to an early, pre-agricultural anthropogenic landscape.info:eu-repo/semantics/publishedVersio
A warm Jupiter transiting an M dwarf: A TESS single transit event confirmed with the Habitable-zone Planet Finder
We confirm the planetary nature of a warm Jupiter transiting the early M
dwarf TOI-1899, using a combination of available TESS photometry;
high-precision, near-infrared spectroscopy with the Habitable-zone Planet
Finder; and speckle and adaptive optics imaging. The data reveal a transiting
companion on an -day orbit with a mass and radius of $0.66\pm0.07\
\mathrm{M_{J}}1.15_{-0.05}^{+0.04}\ \mathrm{R_{J}}\mathrm{T_{eq}}\sim362$ K) gas giant orbiting an M0 star. Our observations
reveal that TOI-1899.01 is a puffy warm Jupiter, and we suggest additional
transit observations to both refine the orbit and constrain the true dilution
observed in TESS.Comment: 24 pages, 5 figures, 3 tables, published in A
The unusual M-dwarf Warm Jupiter TOI-1899~b: Refinement of orbital and planetary parameters
TOI-1899~b is a rare exoplanet, a temperate Warm Jupiter orbiting an M-dwarf,
first discovered by \citet{Canas2020_toi1899} from a TESS single-transit event.
Using new radial velocities (RVs) from the precision RV spectrographs HPF and
NEID, along with additional TESS photometry and ground-based transit follow-up,
we are able to derive a much more precise orbital period of ~d, along with a radius of ~\unit{R_{J}}. We have also improved the constraints on planet
mass, ~\unit{M_{J}}, and eccentricity, which is consistent
with a circular orbit at 2 (). TOI-1899~b
occupies a unique region of parameter space as the coolest known ( 380~K) Jovian-sized transiting planet around an M-dwarf; we show that
it has great potential to provide clues regarding the formation and migration
mechanisms of these rare gas giants through transmission spectroscopy with JWST
as well as studies of tidal evolution.Comment: 19 pages, 7 figures, 3 tables, submitted to AJ (comments welcome
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