Booz Allen Hamilton
  • Tysons Corner, United States
Recent publications
Adult day services centers (ADSCs) play an important role in long-term services and supports (LTSS), but no studies have examined ADSC nursing staff turnover. This study estimates full-time nursing aide turnover rates and examines ADSC provider characteristics associated with turnover using the 2018 National Post-Acute and Long-term Care Study, a nationally representative sample of 672 ADSCs in the United States. The average turnover percent for aides was 18.5% (range: 0–60%). Attending care plan meetings often was associated with a 6% lower aide turnover rate (95% CI: −11 to − 0.74). A higher proportion of participants needing bathing assistance was associated with a 0.11% higher turnover rate (95% CI: 0.04 to 0.18). Lastly, providing 11–20 hours of continuing education to aides was associated with a 6.6% increase in turnover (95% CI: 1.1 to 12). This study expands knowledge of nursing aide turnover in an under-explored LTSS setting.
This article advances the geographic grid approach to military unmanned aircraft systems (UAS) routing featured in the existing literature. Its contributions are twofold. First, it demonstrates an empirical scoring system to determine the most important areas for maritime domain awareness-focused intelligence, surveillance, and reconnaissance collection, applying the method to the South China Sea. Second, it introduces what we call the “team orienteering problem with prize-dependent loitering times” (TOP-PDLT) and uses that model to identify optimal UAS collection routes in the South China Sea. Compared with other grid-based UAS routing schemes that use service time-dependent profits, TOP-PDLT is shown to be particularly applicable to military use-cases.
This paper describes the Grid Optimization (GO) Competition Challenge 3, focusing on the problem motivation, formulation, solvers submitted by competition entrants, and analysis of the solutions produced. Funded by DOE/ARPA-E and led by a collaboration of national labs and academia members, the GO Competition addresses challenging problems in power systems planning and operations to drive research in advanced solution methods essential for a rapidly evolving electric power sector. Challenge 3 targets a multi-period unit commitment problem, incorporating AC power modeling and topology switching to reflect the dynamic grid management techniques required for future power systems. The competition results offer significant benefits to both researchers and industry practitioners. For researchers, it fosters innovation, encouraging the development of new algorithms to address the complexities of modern power systems. For industry practitioners, the competition drives the creation of more efficient and reliable computational tools, directly improving grid management practices. This collaboration bridges the gap between theory and practical implementation, advancing the field in meaningful ways. This paper documents the problem formulation, solver approaches, and the effectiveness of the solutions developed.
The reflectance-based vicarious calibration approach uses measurements at well-understood test sites to provide top-of-atmosphere reference reflectance values suitable for inter-calibration approaches and does not require coincident views. The challenge is that results from such data may suffer from high variability from day to day. Data from high-quality sensors, such as the imaging spectrometers on the International Space Station (ISS) platform, provide an opportunity to use improved fine spectral information about the test sites with various sun/sensor geometries and site surface and atmospheric conditions to improve the test sites’ characterization. The results here are based on data from the DLR Earth Sensing Imaging Spectrometer (DESIS) instrument installed on the ISS since 2018 combined with output from the Radiometric Calibration Network (RadCalNet) site at Railroad Valley Playa (RRV) to decouple the effects of sun/sensor geometry from the RadCalNet predictions. The approach here uses the precessing orbit of the ISS to allow similar sensor view zenith angles at varying sun angles over short periods that limit the impact of any sensor changes and highlight the bi-directional effects of the surface reflectance and atmospheric conditions. DESIS data collected at (i) similar solar angles but varying view angles, (ii) similar sensor angles and varying solar angles, and (iii) similar scatter angles are compared. The DESIS results indicate that the top-of-atmosphere reflectance spectra for RRV at similar solar zenith angles but with varying sensor viewing angles provide more consistent data than those with varying solar zenith but with similar sensor viewing angles. In addition, comparisons of reflectance spectra of the site performed in terms of the sensor view scatter angle show good agreement, indicating that a directional reflectance correction would be straightforward and could offer a significant improvement in the use of RadCalNet data. The work shows that observations from imaging spectroscopy data from DESIS, and eventually Earth Surface Mineral Dust Source Investigation (EMIT), Surface Biology and Geology (SBG), and the climate-quality sensor CLARREO Pathfinder (CPF), provide the opportunity for the development of a model-based, SI-traceable prediction of at-sensor radiance over the RRV site that would serve as the basis for similar site characterizations with error budgets valid for arbitrary view and illumination angles.
Astronomy and Space Domain Awareness are limited by the size of available telescope optics, the cost for which scales steeply due to the exquisitely ground and polished primary mirrors, typically made of glass or other lightweight substrates. Liquid mirrors (LMs) may break this unfavorable cost scaling. When rotated at a constant angular velocity, it has been shown that fluid surfaces take the form of a paraboloid, which can function as a primary mirror. However, current LMs cannot slew or tilt off-zenith due to gravity, greatly limiting the viewing area in the sky. To overcome these limitations while also enabling low-cost, very-large-aperture telescopes , the Defense Advanced Research Projects Agency launched the Zenith program. Zenith is developing entirely new LM design-for-build approaches that can create large optical surfaces without rotation and maintain the optical quality during tilt and slew by correcting transient liquid surface aberrations in real time. The development of these new designs is being supported by multi-physics models, materials, surface and field controls, and structures. We discuss key and fundamental aspects of four new design and modeling approaches for this new class of LMs, and the software and simulation tools developed by the Zenith program to design tiltable and size-scalable liquid mirrors.
The quantum interference effects of mixing the most non-classical states of light, number states, with the most classical-like of pure field states, the coherent state, are investigated. We demonstrate how the non-classicality of a single photon when mixed with a coherent field can transform the statistical properties of the output and further demonstrate that the entanglement of the output is independent of the coherent state amplitude. This article is part of the theme issue ‘The quantum theory of light’.
Targeted knockout, mutations, or knock-in of genomic DNA fragments in model organisms have been used widely for functional and cell-tracking studies. The desired genetic perturbation is often accomplished by recombination-based or CRISPR/Cas9-based genome engineering. For validating the intended genetic modification, a local region surrounding the targeted locus is typically examined based on enzymatic cleavage and consequent length patterns, e.g. in a Southern analysis. Despite its wide use, this approach is open to incomplete and ambiguous readouts. With decreasing costs of high-throughput sequencing, it is becoming feasible to consider a large-scale validation of a new strain after a targeted genetic perturbation. Here we describe a dataset of whole-genome sequences and the variant analysis results from four novel reporter mouse strains. This served to validate the strains and identified all the off-target effects on the genome, thereby increasing the genetic diversity of genomic sequences over those represented in the public databases for inbred mice.
Health disparities, leading to worse health outcomes such as elevated COVID-19 mortality rates, are rooted in social and structural factors. These disparities notably impact individuals from lower socioeconomic backgrounds and more socially vulnerable areas. We analyzed the relationship between COVID-19 deaths and social vulnerability using the Minority Health Social Vulnerability Index (MHSVI). COVID-19 death data in the U.S. was obtained from the Centers for Disease Control and Prevention (CDC) National Center for Health Statistics, where COVID-19 deaths were defined using the ICD-10 code U07.1. MHSVI composite scores were calculated for 3089 U.S. counties and categorized into social vulnerability quartiles, where values ranged from 0 (lowest vulnerability) to 1 (highest vulnerability). Negative binomial regression was employed to determine death rate ratios for each quartile within each theme. Finally, a multivariate negative binomial regression including all MHSVI sub-themes, excluding the overall index ranking, was used to assess the association between each theme and COVID-19 death rates independently. There were 1,134,272 COVID-19 deaths from January 1, 2020 through June 24, 2023. Adjusted rate ratios for COVID-19 deaths in the overall index ranking were 1.06 (95% CI 0.99-1.13), 1.14 (95% CI 1.06-1.22), and 1.41 (95% CI 1.31-1.52) for the second, third and fourth quartiles, respectively. Sub-themes of socioeconomic status (SES), household characteristics (HC), racial and ethnic minority status (REMS), housing type and transportation (HTT), and medical vulnerability (MV) revealed increasing death rates in higher vulnerability quartiles. The healthcare infrastructure and access (HIA) theme had decreasing death rate ratios of 0.74 (95% CI 0.71–0.78), 0.59 (95% CI 0.56–0.62), and 0.42 (95% CI 0.39–0.44) for the second, third, and fourth quartiles, respectively. Finally, the multivariate analysis showed that the HC, HTT, HIA, and MV themes were associated with COVID-19 deaths (P < 0.05). Counties that were identified as more socially vulnerable experienced higher death rates from COVID-19. These areas may need additional public health and social support during future pandemics.
Lung cancer remains the leading cause of cancer mortality, despite declining smoking rates. Previous lung cancer GWAS have identified numerous loci, but separating the genetic risks of lung cancer and smoking behavioral susceptibility remains challenging. Here, we perform multi-ancestry GWAS meta-analyses of lung cancer using the Million Veteran Program cohort (approximately 95% male cases) and a previous study of European-ancestry individuals, jointly comprising 42,102 cases and 181,270 controls, followed by replication in an independent cohort of 19,404 cases and 17,378 controls. We then carry out conditional meta-analyses on cigarettes per day and identify two novel, replicated loci, including the 19p13.11 pleiotropic cancer locus in squamous cell lung carcinoma. Overall, we report twelve novel risk loci for overall lung cancer, lung adenocarcinoma, and squamous cell lung carcinoma, nine of which are externally replicated. Finally, we perform PheWAS on polygenic risk scores for lung cancer, with and without conditioning on smoking. The unconditioned lung cancer polygenic risk score is associated with smoking status in controls, illustrating a reduced predictive utility in non-smokers. Additionally, our polygenic risk score demonstrates smoking-independent pleiotropy of lung cancer risk across neoplasms and metabolic traits.
Pregnancy is a hypercoagulable state. There is a lack of strong evidence-based guidance regarding management when anticoagulation is required to prevent or treat venous thromboembolism during pregnancy. In practice, some patients are prescribed enoxaparin and transitioned to heparin due to the shorter half-life in the setting of an unpredictable delivery despite less predictable pharmacokinetics of heparin compared with enoxaparin, while others are continued on enoxaparin with a scheduled delivery. This work retrospectively evaluates obstetrical and neonatal outcomes between these two practices for 194 live singleton deliveries from 179 patients in a single institution January 2017 through May 2022. A Bayesian regression was used to control for confounders including dosing regimens. This work found no statistically significant differences in blood loss at time of delivery or availability of neuraxial anesthesia. This suggests continuing enoxaparin is noninferior to transitioning to heparin when anticoagulation is indicated in pregnancy.
The two near-identical pushbroom Thermal Infrared Sensors (TIRS) aboard Landsat 8 and 9 are currently imaging the Earth’s surface at 10.9 and 12 microns from similar 705 km altitude, sun-synchronous polar orbits. This work validates the consistency in the imaging data quality, which is vital for harmonization of the data from the two sensors needed for global mapping. The overlapping operation of these two near-identical sensors, launched eight years apart, provides a unique opportunity to assess the sensitivity of the conventionally used metrics to any unexpectedly found nuanced differences in their spatial performance caused by variety of factors. Our study evaluates spatial quality metrics for bands 10 and 11 from 2022, the first complete year during which both TIRS instruments have been operational. The assessment relies on the straight-knife-edge technique, also known as the Edge Method. The study focuses on comparing the consistency and stability of eight separate spatial metrics derived from four separate water–desert boundary scenes. Desert coastal scenes were selected for their high thermal contrast in both the along- and across-track directions with respect to the platforms ground tracks. The analysis makes use of the 30 m upsampled TIRS images. The results show that the Landsat 8 and Landsat 9 TIRS spatial performance are both meeting the spatial performance requirements of the Landsat program, and that the two sensors are consistent and nearly identical in both across- and along-track directions. Better agreement, both with time and in magnitude, is found for the edge slope and line spread function’s full-width at half maximum. The trend of averaged modulation transfer function at Nyquist shows that Landsat 8 TIRS MTF differs more between the along- and across-track scans than that for Landsat 9 TIRS. The across-track MTF is consistently lower than that for the along-track, though the differences are within the scatter seen in the results due to the use of the natural edges.
Background: During the ongoing outbreak of clade II monkeypox virus (MPXV), many U.S. patients were prescribed tecovirimat, an antiviral drug that was made available under an expanded access Investigational New Drug (EA-IND) program. We evaluated EA-IND data to summarize characteristics of treated patients, outcomes, and serious adverse events (SAEs). Methods: We evaluated data from patients prescribed tecovirimat from May 29, 2022, through July 10, 2023. Baseline patient characteristics, clinical courses, and outcomes were evaluated via intake forms, outcome forms, and patient diaries. Data were summarized in aggregate by human immunodeficiency virus (HIV) status and by comorbidities of special interest. Reported SAEs were also compiled. Results: Tecovirimat was prescribed for over 7100 patients in the United States, most often for lesions in sensitive anatomical areas, such as certain anogenital lesions (83.5%; 5135 out of 6148 patients), and pain (52.5%; 3227 out of 6148 patients). The demographic and clinical characteristics mirrored those of patients worldwide. Among the 7181 patients with returned intake forms, 1626 also had returned outcome forms (22.6%). Many patients with severe immunocompromise (e.g., HIV with CD4 counts <200 cells/μl) received multiple courses of tecovirimat (43.1%; 22 out of 51 patients), including intravenously, and often experienced poor outcomes (35.3%; 18 out of 51 patients). Overall, 223 SAEs and 40 deaths were reported. Most SAEs were among patients who were severely immunocompromised, one of whom experienced hallucinations after tecovirimat was administered at twice the standard dose. Conclusions: Tecovirimat was used extensively. The returned EA-IND data suggest that life-threatening or protracted infections occurred in persons who were severely immunocompromised. SAEs were not commonly reported. The EA-IND data are not definitive; controlled clinical trial data are essential to elucidating if and how tecovirimat should be used.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
1,029 members
Information
Address
Tysons Corner, United States