Search NASA⌕ Search

SEARCH · Search NASA

Results for “Administration”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

CO 2 Pipeline risk assessment and comparison for the midcontinent United States

For this work, a comprehensive quantitative risk assessment for the construction and operation of CO 2 transportation networks considered for the Midcontinent United States was conducted. The results showed risks associated with CO 2 pipelines were significantly less than those of other pipeline types. The assessment used four conceptual pipelines of different lengths to discuss risks operators may see. The assessment evaluated the risk associated with construction and operation using data from the US Occupational Safety Health Administration to determine the risk of injury or death for pipeline workers and data from the US Pipeline and Hazardous Materials Safety Administration for CO 2 , natural gas distribution, natural gas transmission/gathering, and non-CO 2 hazardous liquid pipelines to develop quantitative likelihood and severity values leading to risk values. The data for the assessment covered incidents from 2010 to 2017 for CO 2 pipelines. The average risk for construction and 30 years of operation for four CO 2 pipeline configurations ranging between 79 and 1,546 miles in length was found. The construction and operational risk averaged between $\$1,400,521$ (approximately $\$0.02$/tonne of CO 2 ) for the shorter pipeline (79 miles) and $\$27,481,939$ (approximately $\$0.10$/tonne of CO 2 ) for a longer pipeline (1,546 miles). The largest risks of fatality for CO 2 pipelines comes from vehicle transport. The largest operational risk to the pipeline was due to leakage. Public pipeline opposition is also a significant risk; it was not quantified but is addressed.

03 NATURAL GAS↗
DOE OSTI2022

Determining critical overlap concentration of polyethylene oxide to support excipient safety assessment of opioid products

Intravenous administration of abuse-deterrent opioid products poses high safety risks, in part due to the presence of high molecular weight polymeric excipients. Previous in vivo studies in animal models have shown that the higher molecular weight (Mw) polymeric excipients like polyethylene oxide (PEO) were directly linked to such adverse responses as intravenous hemolysis and kidney damage. PEO polymers have been widely used in abuse-deterrent formulations (ADF) of opioid products, adding to concerns over the general safety of the opioid category due to the unknown safety risk from abuse via unintended routes. Here, the current study focused on the determination of the critical overlap concentration (c*) at various PEO molecular weights to aid in explaining differences in observed adverse responses from previous animal studies on the intravenous administration of PEO solutions. Adverse in vivo responses may be related to the viscoelastic regime of the polymer solution, which depends not only on Mw but also on concentration. Having a localized polymer concentration in the blood above the c*, i.e., the transition from the dilute to semi-dilute entangled viscoelastic regime, may influence the flow behavior and interactions of cells in the blood. The relationship of c* to this combination of physical, chemical, and rheological effects is a possible driving force behind adverse in vivo responses.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

The effect of food vehicles on in vitro performance of pantoprazole sodium delayed release sprinkle formulation

Certain patient populations, including children, the elderly or people with dysphagia, find swallowing whole medications such as tablets and capsules difficult. To facilitate oral administration of drugs in such patients, a common practice is to sprinkle the drug products (e.g., usually after crushing the tablet or opening the capsule) on food vehicles before consumption which improves swallowability. Thus, evaluation of the impact of food vehicles on the potency and stability of the administered drug product is important. Here, the aim of the current study was to evaluate the physicochemical properties (viscosity, pH, and water content) of common food vehicles used for sprinkle administration (e.g., apple juice, applesauce, pudding, yogurt, and milk) and their impacts on the in vitro performance (i.e., dissolution) of pantoprazole sodium delayed release (DR) drug products. The food vehicles evaluated exhibited marked difference in viscosity, pH and water content. Notably, the pH of the food as well as the interaction between food vehicle pH and drug-food contact time were the most significant factors affecting the in vitro performance of pantoprazole sodium DR granules. For example, the dissolution of pantoprazole sodium DR granules sprinkled on food vehicles of low pH (e.g., apple juice or applesauce) for short durations remained unchanged compared with the control group (i.e., without mixing with food vehicles). However, use of high pH food vehicles (e.g., milk) with prolonged contact time (e.g., 2h) resulted in accelerated pantoprazole release, drug degradation and loss of potency. Overall, a thorough assessment of physicochemical properties of food vehicles and formulation characteristics are a necessary part of the development of sprinkle formulations.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Overcoming Barriers to Radiopharmaceutical Therapy (RPT): An Overview From the NRG-NCI Working Group on Dosimetry of Radiopharmaceutical Therapy

Radiopharmaceutical therapy (RPT) continues to demonstrate tremendous potential in improving the therapeutic gains in radiation therapy by specifically delivering radiation to tumors that can be well assessed in terms of dosimetry and imaging. Dosimetry in external beam radiation therapy is standard practice. This is not the case, however, in RPT. This NRG (acronym formed from the first letter of the 3 original groups: National Surgical Adjuvant Breast and Bowel Project, the Radiation Therapy Oncology Group, and the Gynecologic Oncology Group)-National Cancer Institute Working Group review describes some of the challenges to improving RPT. The main priorities for advancing the field include (1) developing and adopting best practice guidelines for incorporating patient-specific dosimetry for RPT that can be used at both large clinics with substantial resources and more modest clinics that have limited resources, (2) establishing and improving strategies for introducing new radiopharmaceuticals for clinical investigation, (3) developing approaches to address the radiophobia that is associated with the administration of radioactivity for cancer therapy, and (4) solving the financial and logistical issues of expertise and training in the developing field of RPT.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2022

Automated fault detection and diagnosis deployment Internet of Things solution for building energy system

The building sector is the highest energy consumer and ranks first in terms of carbon emissions among all sectors. To address these issues, decarbonization and electrification in the building energy sector are two critical missions of the new US administration. For decarbonization, the new administration has set a target to reduce greenhouse gas emissions by 50–52% by 2030 and targeting a carbon-neutral economy by 2050. For electrification, the goal is to achieve 100% clean electricity by 2035. Such decarbonization and electrification in the building sector require that energy consumption in buildings be reduced significantly. Therefore, the building sector must continuously adopt new technologies to achieve its energy and carbon emission goals. One of the most fundamental technologies is the Internet of Things (IoT). IoT has proven to be an effective solution for the building domain, including building information/energy modeling, smart buildings, etc. Although much progress has been made in the development of IoT-based building energy systems, there is still a lack of reliable, scalable, and affordable IoT-based automated fault and degradation diagnostic (AFDD) solutions. Such solutions would enable deployment of advanced algorithms into real systems to archive the projected energy benefits. Here, this study reviews existing IoT solutions developed for building energy–related application and developed a simple but effective AFDD IoT deployment solution, including developing a suitable IoT architecture and conducting easy and scalable deployment by leveraging a common cloud-based IoT service.

42 ENGINEERING↗
DOE OSTI2025

Thermal performance and energy consumption validation of an occupied local government office building outfitted with ceiling tile phase change materials

Buildings present an opportunity for energy conservation and the modulation of peak energy demand through controlled Heating, Ventilation, and Air Conditioning (HVAC) energy use. The administrative and office building stock in the United States holds potential to achieve energy and demand savings through retrofits such as insulation, weatherization, and thermal energy storage. Specifically, there is a need to validate passive phase change material (PCM) applications in full scale in aging administrative buildings in the US to evaluate the energy benefits. Aim of this study was to conduct a whole building level thermal and energy validation of an operational building and explore an alternative method for evaluating energy efficiency. To accomplish this, the study employed PCMs in the drop ceiling and carry out an energy audit and on-site measurement of HVAC systems' energy demand and consumption. A full-scale EnergyPlus energy model, modeled by the authors, served as a baseline for evaluation. The results show that calibrated model's envelope temperature measures fall within the accepted errors. HVAC energy simulation results also fall within the accepted errors for monthly and hourly pre- and post- PCM retrofit electricity and natural gas data. The novelty of this study is that it employees energy scales per Heating Degree Hour and Cooling Degree Hour, in contrast to the commonly used Heating Degree Days and Cooling Degree Days as reported in the literature to analyze energy savings. These findings underscore the pivotal role of a calibrated model in assessing the efficacy of a singular energy measure, like a PCM-retrofitted ceiling, in an occupied office building.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2020

In-Use Interfacial Stability of Monoclonal Antibody Formulations Diluted in Saline i.v. Bags

The use of monoclonal antibodies (mAbs) for the treatment of a variety of diseases is rapidly growing each year. Many mAbs are administered intravenously using i.v. bags containing 0.9% NaCl (normal saline). We studied the aggregation propensity of these antibody solutions in saline and compared it with a low ionic strength formulation buffer. Furthermore, the mAb studied in this work is prone to aggregate, and is known to form a viscoelastic network at the air-solution interface. We observed that this interfacial elasticity increased when formulated in saline. In the bulk, the mAbs exhibited a tendency to self-associate that was higher in saline. We also studied the aggregation of the mAbs in the presence of polysorbate-20, typically added to formulations to mitigate interfacial aggregation. We observed that with surfactants, the presence of salt in the buffer led to a greater mAb adsorption at the interface and resulted in the formation of more particulate aggregates. Our results show that the addition of salt to the buffer led to differences in the interfacial aggregation in mAb formulations, showing that stress studies used to screen for mAb aggregation intended for i.v. administration should be performed in conditions representative of their intended route of administration.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Glucocorticoids suppressed osteoblast differentiation by decreasing Sema3A expression via the PIK3/Akt pathway

Highlights: • Dex decreased Sema3A expression by suppressing the PI3K/Akt pathway. • Sema3A reversed Dex-induced suppression of osteoblast differentiation. • Sema3A reversed the Dex-mediated reduced transcriptional activity of β-catenin. Glucocorticoids(GCs) are extensively used to treat inflammatory and autoimmune diseases. Excessive prolonged exposure to glucocorticoids is associated with an increased risk of osteoporosis. The inhibition of osteoblast differentiation by GCs is suggested as a major cause for GCs-induced osteoporosis (GIO). However, the precise mechanism underlying the role of GCs in osteoblasts differentiation is not fully elucidated. Semaphorin 3A (Sema3A), a secreted member of the Semaphorin family, enhances bone formation and promotes fracture healing, which is known to increase osteoblastic differentiation and stimulate osteogenesis in bone metabolism. Here, the present study explored the effect of Sema3A in osteoblast differentiation using dexamethasone (Dex) treatment of bone marrow stromal cells (BMSCs). Dex treatment decreased Sema3A expression in BMSCs in a dose-dependent manner. Moreover, Dex stimulation suppressed the differentiation of osteoblasts by reducing alkaline phosphatase (ALP) activity, osteoblastic marker genes expression and mineralization, but all of these effects were ameliorated by exogenous recombinant Sema3A administration. Furthermore, exogenous Sema3A administration reversed the Dex-mediated decrease in nuclear accumulation of β-catenin and β-catenin activity in BMSCs. Meanwhile, Dex was capable of simultaneously suppressing the phosphorylation of protein kinase B(Akt) and the expression level of Sema3A in BMSCs. These changes were significantly abolished by the PI3K/Akt agonist. These results suggest that Dex inhibits osteoblast differentiation by suppressing Sema3A expression via the PI3K/Akt pathway. These data provide new insights into the molecular mechanisms of Dex-induced osteoblast differentiation inhibition.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

Evaluation of Copper Chelation Therapy in a Transgenic Rat Model of Cerebral Amyloid Angiopathy

Cerebral amyloid angiopathy (CAA) is characterized by the accumulation of the amyloid β (Aβ) protein in blood vessels and leads to hemorrhages, strokes, and dementia in elderly individuals. Recent reports have shown elevated copper levels colocalized with vascular amyloid in human CAA and Alzheimer’s disease patients, which have been suggested to contribute to cytotoxicity through the formation of reactive oxygen species. Here, we treated a transgenic rat model of CAA (rTg-DI) with the copper-specific chelator, tetrathiomolybdate (TTM), via intraperitoneal (IP) administration for 6 months to determine if it could lower copper content in vascular amyloid deposits and modify CAA pathology. In this work, results showed that TTM treatment led to elevated Aβ load in the hippocampus of the rTg-DI rats and increased microbleeds in the wild type (WT) animals. X-ray fluorescence microscopy was performed to image the distribution of copper and revealed a surprising increase in copper colocalized with Aβ aggregates in TTM-treated rTg-DI rats. Unexpectedly, we also found an increase in the copper content in unaffected vessels of both rTg-DI and WT animals. These results show that IP administration of TTM was ineffective in removing copper from vascular Aβ aggregates in vivo and increased the development of disease pathology in CAA.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Phage-specific immunity impairs efficacy of bacteriophage targeting Vancomycin Resistant Enterococcus in a murine model

Bacteriophage therapy is a promising approach to address antimicrobial infections though questions remain regarding the impact of the immune response on clinical effectiveness. Here, we develop a mouse model to assess phage treatment using a cocktail of five phages from the Myoviridae and Siphoviridae families that target Vancomycin-Resistant Enterococcus gut colonization. Phage treatment significantly reduces fecal bacterial loads of Vancomycin-Resistant Enterococcus. We also characterize immune responses elicited following administration of the phage cocktail. While minimal innate responses are observed after phage administration, two rounds of treatment induces phage-specific neutralizing antibodies and accelerate phage clearance from tissues. Interestingly, the myophages in our cocktail induce a more robust neutralizing antibody response than the siphophages. This anti-phage immunity reduces the effectiveness of the phage cocktail in our murine model. Collectively, this study shows phage-specific immune responses may be an important consideration in the development of phage cocktails for therapeutic use.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2025

Driving the grid forward: How electric vehicle adoption shapes power system infrastructure and emissions

We model the effect of plug-in electric vehicle (EV) adoption on U.S. power system generator capacity investment, operations, and emissions through 2050 by estimating power systems outcomes under a range of EV adoption trajectory scenarios. Our EV adoption scenarios are informed by 1) an Energy Information Administration scenario with no policy intervention, 2) EV growth expected under the Inflation Reduction Act (IRA), 3) a Biden Administration 50% EV sales target by 2030, 4) the Environmental Protection Agency’s projections under vehicle emissions standards, and 5) the International Energy Agency’s roadmap to Net Zero by 2050. We find across these scenarios that increasing EV adoption induces investment in new wind, solar, storage, and natural gas capacity, affecting power generation mix and emissions. The net effect of increasing EV adoption beyond our IRA base case is to increase power sector emissions by about 5 mtCO 2 eq per EV-year in 2026 (comparable to displaced gasoline vehicle combustion emissions), but this effect rapidly drops to annual levels below 1 mtCO 2 eq per EV-year by 2032 and continues below this level through 2050. Consequential effects of EV adoption vary regionally, with most regions primarily increasing wind or solar capacity and some regions primarily increasing natural gas capacity, even in 2050. Our national emissions estimates per EV-year are relatively robust to the level of EV adoption beyond our baseline and to variation in assumptions about power systems, EV behavior, and policy.

Science & Technology - Other Topics↗
DOE OSTI2025

Engineering a protease-stable, oral single-domain antibody to inhibit IL-23 signaling

Interleukin (IL)-23 is a validated therapeutic target in inflammatory bowel disease. While antibodies targeting IL23 demonstrate clinical efficacy, they face challenges such as high costs, safety risks, and the necessity of parenteral administration. Here, we present a workflow to simultaneously enhance the affinity and protease stability of an inhibitory anti-IL23R VHH for oral use. Cocrystal structure analysis reveals that the anti-IL23R VHH employs both CDR and framework residues to achieve picomolar affinity for IL23R. The engineered VHH remains stable for over 8 h in intestinal fluid and 24 h in fecal samples. Oral administration of this VHH achieves deep pathway inhibition in a murine colitis model. Furthermore, a single pill provides sustained IL23R inhibition in nonhuman primate blood for over 24 h. With high potency, gut stability, high production yield, and favorable drug-like properties, oral VHHs offer a promising approach for inflammatory bowel diseases.

Science & Technology - Other Topics↗
DOE OSTI2020

Foreword Special issue on the Kilopower Project, Kilowatt Reactor Using Stirling TechnologY (KRUSTY) Test

This special issue of Nuclear Technology contains full-length, peer-reviewed papers describing the design work leading up to and the results of the Kilowatt Reactor Using Stirling TechnologY (KRUSTY) test. KRUSTY was the centerpiece of the National Aeronautics and Space Administration (NASA) Kilopower Project to design, build, and test a space nuclear reactor. This test was the first such test since the end of the Space Nuclear Auxiliary Power (SNAP) project at the end of the 1960s. In this issue, the introduction paper presents the goals of the Kilopower Project and the potential missions this reactor concept could serve in NASA. Kilopower was intended to serve both human exploration needs on planetary surfaces as well as science needs for deep-space exploration. The design work for the experiment by Poston and the power conversion development by Gibson present the pre-work required to perform the eventual KRUSTY test. A paper on regulatory analysis follows, to show the path used to gain approval of the proposed experiment. Then, the early zero-power critical experiments are presented by Sanchez and Grove. These experiments were essential data used to enhance model predictions prior to the high-temperature test. Next, Poston presents the three experiments (warm criticals) that increase the temperature in an incremental fashion prior to the final experiment. These experiments were used to achieve final regulatory approval of the final high-temperature experiment. The last paper by Poston presents the results of the steady-state and transient testing of the reactor at full power and at the design temperature. These results show that the reactor design and as-built experiment met all of the requirements that NASA had developed for the system. Any experiment of this magnitude was accomplished only because of the hard work and dedication of a large number of people at multiple institutions, including the NASA Glenn Research Center, NASA Marshall Space Flight Center, Y-12 National Security Site, Los Alamos National Laboratory, and the Nevada National Security Site prime contractor (formerly National Security Technologies and now the Mission Support and Test Services). The project was jointly funded by the Space Technology Mission Directorate at NASA and the Criticality Safety Program at the National Nuclear Security Administration (NNSA). A special thanks to Jerry McKamy and Angela Chambers at the NNSA and Lee Mason and Don Palac at NASA for their support and guidance. For the authors and multitude of staff that performed this work, the passion for space nuclear reactors was the key to making this experiment a reality.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2024

Convolutional Non-Homogeneous Poisson Process and its Application to Wildfire Ignition Risk Quantification for Power Delivery Networks

To quantify wildfire ignition risks on power delivery networks, the current practice predominantly relies on the empirically calculated fire danger indices, which may not well capture the effects of dynamically changing environmental factors. This article proposes a spatio-temporal point process model, known as the Convolutional Non-homogeneous Poisson Process (cNHPP), and applies the model to quantify wildfire ignition risks for power delivery networks. The proposed model captures both the current (i.e., instantaneous) and cumulative (i.e., historical) effects of key environmental processes (i.e., covariates) on wildfire risks, as well as the spatio-temporal dependency among different segments of the power delivery network. The computation and interpretation of the intensity function are thoroughly investigated. We apply the proposed approach to estimate wildfire ignition risks on major transmission lines in California, using historical fire data, meteorological and vegetation data obtained from the National Oceanic and Atmospheric Administration and National Aeronautics and Space Administration. Here, a comprehensive comparison study is performed to show the applicability and predictive capability of the proposed approach.

Non-homogeneous Poisson Process↗
DOE OSTI2024

Variable domain mutational analysis to probe the molecular mechanisms of high viscosity of an IgG 1 antibody

Subcutaneous injection is the preferred route of administration for many antibody therapeutics for reasons that include its speed and convenience. However, the small volume limit (typically ≤2 mL) for subcutaneous delivery often necessitates antibody formulations at high concentrations (commonly ≥100 mg/mL), which may lead to physicochemical problems. For example, antibodies with large hydrophobic or charged patches can be prone to self-interaction giving rise to high viscosity. Here, we combined X-ray crystallography with computational modeling to predict regions of an anti-glucagon receptor (GCGR) IgG 1 antibody prone to self-interaction. An extensive mutational analysis was undertaken of the complementarity-determining region residues residing in hydrophobic surface patches predicted by spatial aggregation propensity, in conjunction with residue-level solvent accessibility, averaged over conformational ensembles from molecular dynamics simulations. Dynamic light scattering (DLS) was used as a medium throughput screen for self-interaction of ~200 anti-GCGR IgG 1 variants. A negative correlation was found between the viscosity determined at high concentration (180 mg/mL) and the DLS interaction parameter measured at low concentration (2–10 mg/mL). Additionally, anti-GCGR variants were readily identified with reduced viscosity and antigen-binding affinity within a few fold of the parent antibody, with no identified impact on overall developability. The methods described here may be useful in the optimization of other antibodies to facilitate their therapeutic administration at high concentration.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

Pharmacoepidemiology, Machine Learning and COVID-19: An intent-to-treat analysis of hydroxychloroquine, with or without azithromycin, and COVID-19 outcomes amongst hospitalized US Veterans

Hydroxychloroquine (HCQ) was proposed as an early therapy for coronavirus disease 2019 (COVID-19) after in vitro studies indicated possible benefit. Previous in vivo observational studies have presented conflicting results, though recent randomized clinical trials have reported no benefit from HCQ amongst hospitalized COVID-19 patients. In this work, we examined the effects of HCQ alone, and in combination with azithromycin, in a hospitalized COVID-19 positive, United States (US) Veteran population using a propensity score adjusted survival analysis with imputation of missing data. From March 1, 2020 through April 30, 2020, 64,055 US Veterans were tested for COVID-19 based on Veteran Affairs Healthcare Administration electronic health record data. Of the 7,193 positive cases, 2,809 were hospitalized, and 657 individuals were prescribed HCQ within the first 48-hours of hospitalization for the treatment of COVID-19. There was no apparent benefit associated with HCQ receipt, alone or in combination with azithromycin, and an increased risk of intubation when used in combination with azithromycin [Hazard Ratio (95% Confidence Interval): 1.55 (1.07, 2.24)]. In conclusion, we assessed the effectiveness of HCQ with or without azithromycin in treating patients hospitalized with COVID-19 using a national sample of the US Veteran population. Using rigorous study design and analytic methods to reduce confounding and bias, we found no evidence of a survival benefit from the administration of HCQ.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

Discordant Clinical and Microbiological Outcomes Are Associated With Late Clinical Relapse in Clinical Trials for Complicated Urinary Tract Infections

Abstract Background Current US Food and Drug Administration guidance recommends that the primary endpoint for complicated urinary tract infection clinical trials be a composite of the clinical and microbiological responses, assessed at a fixed point after therapy. Although some participants meet the criteria for clinical success, they do not meet the criteria for microbiological eradication and are classified as treatment failures. These discordant outcomes have raised questions about the utility of the microbiological endpoint. Methods We analyzed participant data from 13 phase 3 clinical trials submitted to the US Food and Drug Administration (N = 4842). Outcomes were determined at the test of cure (TOC) visit, recommended to occur at least 5 days after therapy and at the late follow-up visit, recommended to occur 21 to 28 days after randomization. Clinical and microbiological success were defined as the resolution of complicated urinary tract infection symptoms present at study entry, with no new symptoms (clinical cure), and a reduction in density of the original pathogen to <103 CFU/mL on urine culture (microbiological eradication). Results Among included participants, 70.7% were concordant successes at the TOC visit, 18.0% were discordant failures (clinical cure/microbiological persistence), and 6.7% were concordant failures (clinical failure/microbiological persistence). Discordant participants were at an increased risk for clinical failure at the late follow-up visit, and the risk of late clinical failure increased with time. Conclusions Discordant clinical and microbiological outcomes at the TOC visit were associated with an increased risk of late clinical failure. Microbiological outcomes appear to be an important component of the endpoint.

Immunology↗
DOE OSTI2024

Detecting Important Drivers of Gridded Population Modeling With Machine Learning

High-resolution population datasets have been lever-aged across a broad swath of domains, such as climate change, public policy, humanitarian aid, and rescue operations, among others. Machine learning methods were adopted to generate high-resolution or gridded population estimates by using various geospatial input features such as buildings, roads, and nighttime lights. In this study, we evaluate the importance of population features using Random Forest models across three levels of analysis, utilizing permutation measures. Our research aims to address key questions to enhance our understanding of high-resolution population modeling, such as: Are certain features globally (10 countries collectively) more important than others? Do optimal features vary by country? Within each country, do feature importance differ across administrative units? What similarities exist in feature importance at the global, country, and administrative unit levels? To answer these questions, we leverage the Kneedle algorithm to automate the selection of optimum features. We find that there are patterns displayed by features across spatial boundaries, evidenced by the same feature being the most important indicator of population across 7 of the 10 countries modeled. Our findings indicate that while important features may vary across geographies, certain features consistently hold greater importance than others agnostic of geography.

Lebakula, Viswadeep [ORNL] (ORCID:0000000152935914↗