Office of Science

Physiologic closed-loop controlled (PCLC) medical devices have the potential to enhance therapeutic precision and effectiveness. However, their complexity introduces potential failure modes that may pose risks to patients if not properly evaluated. This study assesses the effectiveness of a mathematical model of the cardiovascular system in predicting PCLC performance metrics through in vivo and in silico comparisons of blood pressure responses to automated fluid infusion. A closed-loop control system for regulating mean arterial pressure (MAP) was implemented using a custom Java-based software application on a tablet. The system operated in two control speed modes, 'slow' and 'fast.' The study was conducted in an animal laboratory using thirteen swine subjects (two were excluded due to hardware-related issues). Following intubation, anesthesia, and splenectomy, hemorrhage was induced until MAP reached 45mmHg, followed by fluid resuscitation using the closed-loop controller targeting 70mmHg. Arterial blood pressure waveforms were continuously recorded, and cardiac output and hematocrit measurements were taken every 15min. The same control algorithm and speed modes were applied to in silico subjects generated with a mathematical model simulating cardiovascular responses to fluid perturbation while the same protocol was simulated. The mathematical model effectively predicted key PCLC performance metrics, including rise time, %overshoot, settling time, and divergence. The simulated results closely matched experimental data and captured differences between slow and fast control speeds. The ability of the mathematical model to predict PCLC performance metrics demonstrates its value in supporting the development and evaluation of automated fluid resuscitation controllers.

Abstract NOAA began operational assimilation of radio occultation (RO) observations from the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC-1) mission over 15 years ago. Since then, other operational and research missions have been incorporated into the operational suite. To increase the volume of RO profiles and their geographical coverage beyond what COSMIC-2 provides, which is mostly limited to the tropical and subtropical regions, NOAA engaged in procurement activities with commercial companies capable of delivering RO data for operational use. Tests were conducted in this study to quantify the value of commercial RO data for numerical weather prediction (NWP) applications and their relative value compared to a U.S. Government RO data source (viz., COSMIC-2). When commercial RO soundings are added to a baseline that already assimilates COSMIC-2 bending angle observations, it is found that commercial RO soundings bring benefits to global weather forecast skill, mostly by reducing the temperature and wind root-mean-squared error globally. As expected, the benefits are larger in the extratropics. Statistics between COSMIC-2 and commercial RO data show similar values, indicating that higher signal-to-noise values are not necessary to improve weather forecasting—at least with current modeling capabilities. The quality of commercial RO is sufficient for current global NWP applications. Finally, and supporting earlier studies with simulated data, results show that global RO data distribution is needed to improve NWP skill globally. Significance Statement The results of this paper are significant because they inform on the value of radio occultation observations from different sources for global numerical weather prediction applications, thus helping decision-makers plan for future commercial data buys.

Abstract The distribution of Pacific hake, Merluccius productus, extends from Northern Canada to Southern Baja California and into the Gulf of California (GC), Mexico. In an emergent fishery in the Northern GC, hake dominates finfish catches from February to May. Developing management strategies aiming to make this fishery sustainable requires estimates of abundance, which can be provided by the acoustic-trawl method. To identify echoes from daytime demersal aggregations of hake, we use ranges of the sum and difference of mean volume backscattering strength (SV) measured at 38 and 120 kHz. More than 90% of the summed 38-kHz volume backscattering coefficient (sV38) associated with hake-only catches are retained using −4.2 < SV120 – SV38 < 0.9 and −122.0 < SV38 + SV120 < −110.4 dB. These ranges mostly differ for cusk-eel, family Ophidiidae, and scorpionfishes, family Scorpaenidae, which are frequently caught with hake in the Northern GC, but overlap completely for sharks, family Triakidae. To estimate the accuracy of the putative hake backscatter, we present a novel method that accounts for the spatial distribution of area backscattering coefficient, the sensitivity and specificity of the hake-identification ranges, and the acoustic-proportions of hake and the other species.

In June 2024, the U.S. Environmental Protection Agency (USEPA)Office of Water published aquatic life screening values for acute freshwater exposures to two widely distributed rubber-tire compounds, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylene diamine (6PPD) and N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylene diamine quinone (6PPD-quinone). The purpose of this critical review is to outline the derivation of these protective values and provide a thorough summary of the toxicity data available at the time of screening value development to help identify current data gaps to inform future research needs. The detection of these compounds in United States waterways and toxicity data indicate short-term exposure to these compounds may present a risk to aquatic organisms. A transformation product of 6PPD, 6PPD-quinone has been found to be highly toxic to certain adult salmonid species. As emerging contaminants for which scientific understanding of toxicity is rapidly evolving, the current 6PPD and 6PPD-quinone data did not fulfill the USEPA's requirements for deriving national recommended 304(a)(1) aquatic life ambient water quality criteria. Therefore, the USEPA developed screening values in accordance with Section 304(a)(2) of the Clean Water Act to provide states, authorized Tribes, and other stakeholders with the best available information on the toxicity of 6PPD and 6PPD-quinone to aquatic organisms. The 2024 USEPA screening values for acute exposures to 6PPD and 6PPD-quinone in freshwaters are 8.9 µg/L (8,900 ng/L) and 11 ng/L, respectively, and are intended to support protection of freshwater aquatic communities from acute effects including coho salmon (Oncorhynchus kisutch), listed as threatened or endangered in several states, based on the best available data. The USEPA will continue to monitor newly reported toxicity data to evaluate the protectiveness of these values.

ABSTRACT Objective Management of most fisheries is currently based on single species, so multispecies interactions often constrain fishing, leading to suboptimal yields or overfishing. Ecosystem-based fisheries management (EBFM) uses a more holistic approach to resource access or allocation and takes advantage of multispecies interactions to spread risk and achieve target yields. Portfolio theory is a commonly applied financial tool that considers covariance between assets in an investment portfolio to reduce the risk of achieving economic return targets. This method can be adapted to EBFM for balancing risk with expected benefits for a portfolio of species’ revenue. Portfolio management considers species interdependencies (covariance in revenue time series), uncertainty, and sustainability constraints. Methods We demonstrate how to apply economic frontier analysis using publicly available landings and revenue data from commercial fisheries and calculate the risk gap between historic portfolios and the EBFM frontier to assess past fishery performance. We identify data challenges and offer guidance on practical decisions for applying portfolio analysis to derive annual efficient frontiers (trade-offs between revenue risk and return) and demonstrate the sensitivity of frontiers to these data decisions and model parameters. Results In accordance with previous portfolio analyses, results show that the multispecies portfolio approach outperformed single-species management and there was forgone revenue for the associated risk taken in the single-species approach. Conclusions These demonstrations as well as guidance on data and analysis are intended to facilitate broader evaluation and application of multispecies fishery management and portfolio theory to fisheries.

While the transition towards university is exciting for many first-year students, it can also result in tremendous stress from the rigour needed in lab reports, midterms and oral presentations, leading to evaluation anxiety. This can create discrepancies between perceived and actual academic performance, impacting mental health. Science education research aims to formulate potential teaching methods to foster a better learning environment in undergraduate courses. This study looked into the effects of students’ assessment experiences on evaluation anxiety, consisting of state (SEA) and trait evaluation anxiety (TEA), and the relationship between study strategies and academic self-efficacy in a large undergraduate science course at a Canadian university. An online survey using a reversed 7-point Likert scale and addressing the above variables was adapted from previous studies and distributed to students (n = 591, 7.1% response rate). Results indicated that students preferred elaboration strategies (problem-solving, summarizing lectures, active recall) over rehearsal strategies (flashcards, rereading and highlighting lecture notes) based on their average values from descriptive statistics in SPSS. Bivariate correlation analysis showed that both learning methods were positively associated with SEA, with a slightly higher correlation for elaboration. SEA and self-efficacy varied inversely; therefore, higher anxiety may be associated with less accurate self-predictions for academic success. It was noted that test/exam anxiety may diminish as the student feels more confident, however it can also boost academic motivation. These findings could inform future research on evaluation anxiety with a larger sample size and less bias from self-reporting and time constraints, implementing pedagogical approaches to minimize anxiety in science education.