Analysis of contaminant residues in honey bee hive matrices.

Pollinators provide ecological services essential to maintaining our food supply and propagating natural habitats. Populations are in decline due to environmental stressors including pesticides, pathogens, and habitat loss. To better understand the impacts of pesticide exposures on colony health, a field survey in Ohio, USA was conducted to monitor the potential contamination of honey bee colonies by pesticides. Apiaries (n = 10) were situated across an agricultural gradient and samples were collected over a 4-week period encompassing corn planting. Dead bees from entrance traps (DBT), pollen, and in-hive (IH) matrices including bee bread, honey, larvae, and nurse bees were analyzed for a whole suite of pesticides. Out of 210 pesticides targeted, 68 residues were quantified across 306 samples. Neonicotinoids, miticides, and fungicides were the dominant pesticide classes identified throughout all the matrix types. Neonicotinoids were detected at higher concentrations and at higher frequencies compared to fungicides, specifically in field pollen samples. DBT also contained high concentrations of these two contaminant classes, although detection frequencies for neonicotinoids were typically lower. Overall, herbicides and non­neonicotinoid insecticides were found with low frequency and at low concentrations. For most pesticide classes, trends for the mean concentrations were DBT > IH nurse bees > field pollen > IH larvae > IH honey. Pesticides were detected in 100 % of samples with concentrations ranging from 0.01 ppb (diphenylamine) to 2790 ppb (clothianidin). All samples were contaminated with at least two pesticide residues, while 19 samples presented over ten detects and maximum detections of 20 in DBT. Pesticide residues were positively correlated with agricultural gradients across sites and sampling periods. These findings reveal that foraging leads to the exposure of the entire colony to a wide range of pesticides. Moreover, residues determined in DBT serve as an effective proxy for monitoring hive matrices with significantly less disturbance to active hives.

Patch-free streaming contrast-rebalanced dichoptic cartoons versus patching for treatment of amblyopia in children aged 3 to 5 years: a pilot, randomized clinical trial.

BACKGROUND: We developed and tested a dichoptic treatment designed for younger children that can be viewed freely and involves a dichoptic manipulation of a popular animation series that enables contrast-rebalancing without disrupting fusion. Our aim was to assess whether this novel amblyopia treatment is superior to patching in children aged 3-5 years. METHODS: A total of 34 children with amblyopia were randomly assigned to contrast-rebalanced dichoptic cartoons (4 hours/week) or patching (14 hours/week) for 2 weeks. Children in the cartoon group continued watching cartoons for an additional 2 weeks. Designed to target the youngest and most treatable children, the dichoptic cartoons presented the entire scene to the amblyopic eye at 100% contrast, while the fellow eye view was presented at reduced contrast with the main character omitted. Best-corrected visual acuity (BCVA), stereoacuity, suppression, and manual dexterity were measured at each visit. RESULTS: After 2 weeks, improvement in amblyopic eye BCVA was greater for dichoptic treatment than for patching, with a mean improvement of 0.11 ± 0.08 versus 0.06 ± 0.09 logMAR, respectively (P = 0.04). Stereoacuity, suppression, and manual dexterity did not improve significantly more in the dichoptic group than the patching group at 2 weeks. After 4 weeks of dichoptic cartoon treatment, mean visual acuity improvement in the dichoptic group was 0.16 logMAR (95% CI, 0.10-0.21). CONCLUSIONS: In our study cohort, a contrast-rebalanced dichoptic cartoon was more effective than patching in treating childhood amblyopia after 2 weeks. Dichoptic cartoons that rebalance contrast to overcome suppression provide an additional treatment option for amblyopia in young children.

It's Not Just What Parents Say, It's Why They Say It: Students' Perceptions of Parents' Motives for Alcohol Communication.

OBJECTIVE: Previous work has investigated parents' reports of motives for communicating with their young adults about alcohol. While parents' self-reported motives may predict intentions to communicate, young adults' perceptions of their parents' motives may be important for understanding young adults' responses to parent alcohol communication. The present study was conducted to explore college students' perceptions of their parents' motives for alcohol communication and to investigate whether perceptions of these motives predict changes in alcohol consumption and related consequences during the transition to college. METHOD: First-year college students (N = 306) participated in a longitudinal survey study. Baseline measures at pre-matriculation (T1) included assessments of student perceptions of their parents' motives for alcohol communication and covariates (e.g., perceived peer descriptive drinking norms, parental modeling and alcohol communication, and drinking and consequences). At a 1-month follow-up (T2), students reported on their alcohol use and consequences. RESULTS: Controlling for other predictors of college student drinking, results indicate that for each one-unit increase in perceived parental reactive communication motives, the incidence rate of typical weekly drinking increased by 9%, and heavy episodic drinking (HED) increased by 21%. Conversely, the incidence rate of HED decreased by 27% for each one-unit increase in perceived maternal family history communication motives. CONCLUSIONS: These findings suggest that college students' perceptions of their parents' motives for alcohol communication can significantly influence their drinking behavior during the transition to college.

Case Series: Bilateral Operative Femoral Neck Stress Fractures in Marine Corps Recruits.

Bone stress injuries are well-documented injury patterns among U.S. Armed Forces recruits because of the rapid increase in frequency and intensity of bone-impacting activities throughout training. In the recruit population, femoral neck stress fractures are of great concern because of their propensity to progress, displace, and lead to lifelong complications like avascular necrosis. We present two cases of bilateral operative femoral neck stress fractures. The first is of a 28-year-old male Marine Corps recruit who experienced bilateral groin pain during the first week of training. He was found to have bilateral grade 4 femoral neck stress fractures with concomitant effusions. Operative management was pursued with bilateral percutaneous pinning. For this patient, one hip had classically indicated operative involvement while on the contralateral hip the decision to operate was based on recent literature predicting progression based on the presence of a joint effusion. The second case is of a 23-year-old male Marine Corps recruit who experienced hip pain in the final few weeks of training. He was also found to have bilateral grade 4 femoral neck stress fractures with concomitant effusions and was similarly operated on. To the best of our knowledge, this is the first reported operative bilateral femoral neck stress fracture case series in a military-aged patient in the literature. A high clinical suspicion for femoral neck stress injuries with early diagnostic imaging for high-risk groups was important in these cases and ultimately led to timely definitive management for this patient.

Changes in Parent-Student Text Message and Phone Call Communication During the Transition to College as Predictors of Cannabis and Simultaneous Use During the First Year.

Parent communication can be protective against cannabis use among young adults. However, changes in parent-student communication frequency naturally occur during the transition from high school to college. Recent research suggests declines in parent-student communication frequency predict increased drinking and consequences during the first year of college, yet these effects on other risky behaviors are unknown. The current study investigated whether post-matriculation changes in frequency of texting/calling with parents predict cannabis use and simultaneous use of cannabis and alcohol, and whether pre-matriculation cannabis and simultaneous use predict changes in communication. First-year students (N = 287, 61.3% female, 50.9% White) reported cannabis and simultaneous use pre- and post-matriculation (T1 & T3) and changes in frequency of texting/calling their mother/father per day (T2). Negative binomial hurdle models examined whether T2 changes in communication frequency predicted T3 cannabis and simultaneous use, and logistic regression models examined whether T1 cannabis and simultaneous use predicted T2 changes in communication frequency. Results revealed that increasing (vs. decreasing) frequency of calling with mothers and texting with fathers was protective against cannabis use, whereas increasing frequency of calling with fathers was associated with greater risk of use. Changes in communication did not significantly predict simultaneous use, nor did pre-matriculation cannabis or simultaneous use predict changes in either mode of communication with parents during the college transition. These findings highlight that changes in mother and father communication may be both beneficial and detrimental to cannabis use depending on the parent and mode of communication. Implications for these findings are discussed.

Effects of gender-affirming hormone therapy on gray matter density, microstructure and monoamine oxidase A levels in transgender subjects.

MAO-A catalyzes the oxidative degradation of monoamines and is thus implicated in sex-specific neuroplastic processes that influence gray matter (GM) density (GMD) and microstructure (GMM). Given the exact monitoring of plasma hormone levels and sex steroid intake, transgender individuals undergoing gender-affirming hormone therapy (GHT) represent a valuable cohort to potentially investigate sex steroid-induced changes of GM and concomitant MAO-A density. Here, we investigated the effects of GHT over a median time period of 4.5 months on GMD and GMM as well as MAO-A distribution volume. To this end, 20 cisgender women, 11 cisgender men, 20 transgender women and 10 transgender men underwent two MRI scans in a longitudinal design. PET scans using [11C]harmine were performed before each MRI session in a subset of 35 individuals. GM changes determined by diffusion weighted imaging (DWI) metrics for GMM and voxel based morphometry (VBM) for GMD were estimated using repeated measures ANOVA. Regions showing significant changes of both GMM and GMD were used for the subsequent analysis of MAO-A density. These involved the fusiform gyrus, rolandic operculum, inferior occipital cortex, middle and anterior cingulum, bilateral insula, cerebellum and the lingual gyrus (post-hoc tests: pFWE+Bonferroni < 0.025). In terms of MAO-A distribution volume, no significant effects were found. Additionally, the sexual desire inventory (SDI) was applied to assess GHT-induced changes in sexual desire, showing an increase of SDI scores among transgender men. Changes in the GMD of the bilateral insula showed a moderate correlation to SDI scores (rho = - 0.62, pBonferroni = 0.047). The present results are indicative of a reliable influence of gender-affirming hormone therapy on 1) GMD and GMM following an interregional pattern and 2) sexual desire specifically among transgender men.

Vaccination invitations sent by warm and competent medical professionals disclosing risks and benefits increase trust and booking intention and reduce inequalities between ethnic groups.

OBJECTIVE: We aim to identify vaccination invitations that foster trust and improve vaccination uptake overall, especially among ethnic minority groups who are more at risk from coronavirus disease (COVID-19) and less likely to be vaccinated. METHOD: In a preregistered 4 × 4 mixed-design experiment, we manipulated how much risk-benefit information the message included within-subjects and the message source between-subjects (N = 4,038 U.K. and U.S. participants, 50% ethnic minority). Participants read four vaccine invitations that varied in vaccination risk-benefit information (randomized order): control (no information), benefits only, risk and benefit, and risk and benefit that mentions vulnerable groups. The messages were sent by one of four sources (random allocation): control (health institution), medical professional (unnamed), warm and competent medical professional (unnamed), and named warm and competent medical professional (Sanjay/Lamar). Participants assessed how much they trusted the message and how likely they would be to book their vaccination appointment. RESULTS: Information about vaccination benefits and risks increased trust, especially among ethnic minority groups-for whom the effect replicated within each group. Trust also increased when the message was sent by a warm and competent medical professional relative to a health institution, but the importance of the source mattered less when more information was shared. CONCLUSIONS: Our research demonstrates the positive impact of outlining the benefits and disclosing the risks of COVID vaccines in vaccination invitation messages. Having a warm and competent medical professional source can also increase trust, especially where the message is limited in scope. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Unmet financial needs among patients crowdfunding to support gynecologic cancer care.

BACKGROUND: Patients may use crowdfunding to solicit donations, typically from multiple small donors using internet-based means, to offset the financial toxicity of cancer care. OBJECTIVE: To describe crowdfunding campaigns by gynecologic cancer patients and to compare campaign characteristics and needs expressed between patients with cervical, uterine, and ovarian cancer. STUDY DESIGN: We queried the public crowdfunding forum GoFundMe.com for "cervical cancer," "uterine cancer," and "ovarian cancer." The first 200 consecutive posts for each cancer type fundraising within the United States were analyzed. Data on campaign goals and needs expressed were manually extracted. Descriptive statistics and bivariate analyses were performed. RESULTS: Among the 600 fundraising pages, the median campaign goal was $10,000 [IQR $5000-$23,000]. Campaigns raised a median of 28.6% of their goal with only 8.7% of campaigns reaching their goal after a median of 54 days online. On average, ovarian cancer campaigns had higher monetary goals, more donors, and larger donation amounts than cervical cancer campaigns and raised more money than both cervical and uterine cancer campaigns. Campaigns were fundraising to support medical costs (80-85%) followed by lost wages (36-56%) or living expenses (27-41%). Cervical cancer campaigns reported need for non-medical costs more frequently than uterine or ovarian cancer campaigns. States without Medicaid expansions (31% of the national population) were over-represented among cervical cancer and uterine cancer, but not ovarian cancer campaigns. CONCLUSIONS: Crowdfunding pages reveal patients fundraising for out-of-pocket costs in the thousands of dollars and a wide range of unmet financial needs based on cancer type.

Ocular Biometric Components in Hyperopic Children and a Machine Learning-Based Model to Predict Axial Length.

Purpose: The purpose of this study was to investigate the development of optical biometric components in children with hyperopia, and apply a machine-learning model to predict axial length. Methods: Children with hyperopia (+1 diopters [D] to +10 D) in 3 age groups: 3 to 5 years (n = 74), 6 to 8 years (n = 102), and 9 to 11 years (n = 36) were included. Axial length, anterior chamber depth, lens thickness, central corneal thickness, and corneal power were measured; all participants had cycloplegic refraction within 6 months. Spherical equivalent (SEQ) was calculated. A mixed-effects model was used to compare sex and age groups and adjust for interocular correlation. A classification and regression tree (CART) analysis was used to predict axial length and compared with the linear regression. Results: Mean SEQ for all 3 age groups were similar but the 9 to 11 year old group had 0.49 D less hyperopia than the 3 to 5 year old group (P < 0.001). With the exception of corneal thickness, all other ocular components had a significant sex difference (P < 0.05). The 3 to 5 year group had significantly shorter axial length and anterior chamber depth and higher corneal power than older groups (P < 0.001). Using SEQ, age, and sex, axial length can be predicted with a CART model, resulting in lower mean absolute error of 0.60 than the linear regression model (0.76). Conclusions: Despite similar values of refractive errors, ocular biometric parameters changed with age in hyperopic children, whereby axial length growth is offset by reductions in corneal power. Translational Relevance: We provide references for optical components in children with hyperopia, and a machine-learning model for convenient axial length estimation based on SEQ, age, and sex.

Text Messages Conveying Parental Drinking Limits: A Potential Avenue for Preventing and Reducing Alcohol Use in College Students.

OBJECTIVE: Although previous research has established that students who perceive that their parents have lower drinking limits on underage drinking consume less alcohol, optimal approaches for effectively communicating these limits are less understood. To address this gap in the literature, the present study examined the effects of hypothetical limit-focused text messages on estimated drinking behavior. METHOD: Undergraduate college students (N = 253) completed an online survey in which they were instructed to imagine a scenario in which they were planning to go out at night to an event involving drinking. Participants were randomly assigned to a condition in which they would receive one of four hypothetical text messages from their mother and/or father containing a range of drinking limits. They were then asked to report how much alcohol they would realistically consume on this night if they were and were not obligated to check in with their parent at the end of the night. RESULTS: Hypothetical text messages from mothers and fathers containing lower drinking limits resulted in lower estimated alcohol consumption. A drinking limit of zero resulted in the least amount of expected alcohol consumption, but specifying 1-2 drinks as a limit might produce a similar effect if parents also required their student to check in at the end of the night. CONCLUSIONS: Findings from this study provide initial support for future studies to investigate the effects of limit-setting text messages sent from parents on college student drinking as well as the effects of text messages sent from parents requiring that students check in.

Process Evaluation and Investigation of Cultural Adaptations for an Online Parent-Based Intervention Using a Mixed-Method Approach.

Most alcohol intervention research focuses on program efficacy, yet few studies have investigated the acceptability of a program's design and implementation to the target population or adapting existing alcohol interventions to different populations. To address these gaps in the literature, we (1) examined participant responsiveness to and implementation quality of FITSTART+, a web-app delivered parent-based alcohol intervention designed for incoming first-year college students in the United States, and (2) gathered feedback on how this intervention could be adapted to other populations of parents. A sample of U.S. parents of 17-20-year-old first-year college students (N = 109) participated in FITSTART+ during their child's first year of college and completed a survey about parents' responsiveness to the app and its quality. Next, a sample of non-U.S. parents of adolescents aged 13 to 19 (N = 44) participated in one of 11 focus groups in which they briefly explored the app and then discussed how it could be adapted to be applicable and culturally relevant for them and their context. Results revealed that U.S. parents rated the intervention's quality as high and parents were responsive to the web-app's content, but some did not visit one of the most critical aspects of the intervention (i.e., alcohol-related parenting resources). Non-U.S. participants provided a range of suggestions for adapting the intervention to their context, which varied by culture. Results identify areas for improvement, particularly regarding the use of alcohol-related parenting resources, in this intervention and for web-delivered PBIs more broadly.

Perceptions of a reduced nicotine policy and predictors of policy support: A nationally representative U.S. survey.

BACKGROUND: The U.S. Food and Drug Administration is considering a policy to reduce nicotine in cigarettes to non-addictive levels. Although current evidence supports the public-health benefits of a reduced-nicotine policy, almost half of people who smoke (∼ 40%) do not support the policy. This study estimates the factors most strongly associated with support or opposition toward the policy, including tobacco use status, perceived effects of a reduced nicotine policy, trust in the FDA, and psychological distress. The study aims to inform messaging campaigns and policy makers. METHODS: Data were collected in 2021 with nationally representative samples of U.S. adults (n = 1763). After receiving information about the reduced nicotine policy, participants indicated their beliefs and support for or opposition to the policy, along with other individual difference characteristics. Univariate population parameters and multinomial logistic regression coefficients were estimated. RESULTS: In adjusted models, people who formerly or never smoked were less likely to oppose the policy compared to those who currently smoke; people with higher psychological distress and those who believe the policy will promote switching to e-cigarettes were more likely to oppose the policy. In addition, people were more likely to support the policy if they believed it would make quitting easier or that the FDA is trustworthy. CONCLUSIONS: Educational campaigns about reduced nicotine policy should expect higher impact by targeting prevalent perceptions and those more strongly associated with policy sentiment. In anticipation of the policy rollout, there may be a critical window to shape public opinion.

Independent and combined effects of very low nicotine cigarette messages and e-cigarette messages: a randomised clinical trial.

BACKGROUND: USA is considering reducing nicotine in cigarettes to non-addictive levels, coupled with promoting alternative nicotine delivery products (eg, e-cigarettes). However, effective communication is needed to reduce misperceptions about very low nicotine cigarettes (VLNCs) being less harmful than regular cigarettes. METHODS: In 2022-2023, we conducted a four-group randomised clinical trial with a national probability sample from an online panel (971 adults who smoked cigarettes exclusively, 472 adults who dual used cigarettes and e-cigarettes and 458 adults aged 18-29 who had never smoked). Participants were randomised (parallel assignment) to one message condition: (1) VLNCs as harmful but easier to quit than regular cigarettes (n=468), (2) those who are not ready to quit should consider switching to e-cigarettes as less harmful alternatives (n=484), (3) combined (VLNC and e-cigarette messages; n=476) or (4) control condition (ie, water ads), n=473. The primary outcome was perceived absolute harm of VLNCs. RESULTS: Perceived harm of VLNCs was higher in the VLNC condition compared with the e-cigarette and control conditions, and higher in the combined condition compared with the e-cigarette condition (adjusted p<0.05). Among adults who dual used, intention to switch to e-cigarettes was higher in the VLNC condition than the e-cigarette, combined or control conditions (adjusted p<0.05). CONCLUSIONS: VLNC messages reduced the misperception that VLNCs are less harmful than cigarettes, but adding messages about e-cigarettes did not enhance desired outcomes. These VLNC messages can be considered during the rollout of a reduced nicotine policy. TRIAL REGISTRATION: NCT05506046.

Measuring factors affecting honey bee (Hymenoptera: Apidae) attraction to soybeans using bioacoustics monitoring.

Soybean (Glycine max (L.) Merr.) is an important agricultural crop around the world, and previous studies suggest that honey bees (Apis mellifera Linnaeus) can be a component for optimizing soybean production through pollination. Determining when bees are present in soybean fields is critical for assessing pollination activity and identifying periods when bees are absent so that bee-toxic pesticides may be applied. There are currently several methods for detecting pollinator activity, but these existing methods have substantial limitations, including the bias of pan trappings against large bees and the limited duration of observation possible using manual techniques. This study aimed to develop a new method for detecting honey bees in soybean fields using bioacoustics monitoring. Microphones were placed in soybean fields to record the audible wingbeats of foraging bees. Foraging activity was identified using the wingbeat frequency of honey bees (234 ±â€…14 Hz) through a combination of algorithmic and manual approaches. A total of 243 honey bees were detected over 10 days of recording in 4 soybean fields. Bee activity was significantly greater in blooming fields than in non-blooming fields. Temperature had no significant effect on bee activity, but bee activity differed significantly between soybean varieties, suggesting that soybean attractiveness to honey bees is heavily dependent on varietal characteristics. Refinement of bioacoustics methods, particularly through the incorporation of machine learning, could provide a practical tool for measuring the activity of honey bees and other flying insects in soybeans as well as other crops and ecosystems.

Motion-Defined Form Perception in Deprivation Amblyopia.

Purpose: The purpose of this study was to assess motion-defined form perception, including the association with clinical and sensory factors that may drive performance, in each eye of children with deprivation amblyopia due to unilateral cataract. Methods: Coherence thresholds for orientation discrimination of motion-defined form were measured using a staircase procedure in 30 children with deprivation amblyopia and 59 age-matched controls. Visual acuity, stereoacuity, fusion, and interocular suppression were also measured. Fixation stability and fellow-eye global motion thresholds were measured in a subset of children. Results: Motion-defined form coherence thresholds were elevated in 90% of children with deprivation amblyopia when viewing with the amblyopic eye and in 40% when viewing with the fellow eye. The deficit was similar in children with a cataract that had been visually significant at birth (congenital) and in children for whom the cataract appeared later in infancy or childhood (developmental). Poorer motion-defined form perception in amblyopic eyes was associated with poorer visual acuity, poorer binocular function, greater interocular suppression, and the presence of nystagmus. Fellow-eye deficits were not associated with any of these factors, but a temporo-nasal asymmetry for global motion perception in favor of nasalward motion suggested a general disruption in motion perception. Conclusions: Deficits in motion-defined form perception are common in children with deprivation amblyopia and may reflect a problem in motion processing that relies on binocular mechanisms.

Large library docking for cannabinoid-1 receptor agonists with reduced side effects.

Large library docking can reveal unexpected chemotypes that complement the structures of biological targets. Seeking new agonists for the cannabinoid-1 receptor (CB1R), we docked 74 million tangible molecules, prioritizing 46 high ranking ones for de novo synthesis and testing. Nine were active by radioligand competition, a 20% hit-rate. Structure-based optimization of one of the most potent of these (Ki = 0.7 uM) led to '4042, a 1.9 nM ligand and a full CB1R agonist. A cryo-EM structure of the purified enantiomer of '4042 ('1350) in complex with CB1R-Gi1 confirmed its docked pose. The new agonist was strongly analgesic, with generally a 5-10-fold therapeutic window over sedation and catalepsy and no observable conditioned place preference. These findings suggest that new cannabinoid chemotypes may disentangle characteristic cannabinoid side-effects from their analgesia, supporting the further development of cannabinoids as pain therapeutics.

Effects of the FITSTART + PBI on drinking and negative alcohol-related consequences during the first year of college.

Objective: This study evaluated FITSTART+, a parent-based intervention (PBI), for preventing risky drinking among first-year college students. Participants: Participants were traditional first-year students aged between 17 and 20. Method: In total, 391 eligible students completed a baseline survey and their parents were then invited to use the FITSTART+ PBI or Control web-applications. 266 students had a parent who created a profile in the app (FITSTART+ PBI, n = 134; FITSTART+ Control, n = 132). Additionally, 58 parents randomized to the FITSTART+ PBI did not complete the personalized normative feedback (PNF) component of the intervention. Results: No significant effect on drinking or related consequences was detected between Intervention and Control groups. However, exploratory analyses revealed that completing PNF in the FITSTART+ PBI condition was associated with a greater likelihood of remaining zero on consequences at follow-ups. Conclusion: The PNF component of the FITSTART+ PBI showed potential in preventing risky drinking, warranting further research.

Water Table Depth Estimates over the Contiguous United States Using a Random Forest Model.

Water table depth (WTD) has a substantial impact on the connection between groundwater dynamics and land surface processes. Due to the scarcity of WTD observations, physically-based groundwater models are growing in their ability to map WTD at large scales; however, they are still challenged to represent simulated WTD compared to well observations. In this study, we develop a purely data-driven approach to estimating WTD at continental scale. We apply a random forest (RF) model to estimate WTD over most of the contiguous United States (CONUS) based on available WTD observations. The estimated WTD are in good agreement with well observations, with a Pearson correlation coefficient (r) of 0.96 (0.81 during testing), a Nash-Sutcliffe efficiency (NSE) of 0.93 (0.65 during testing), and a root mean square error (RMSE) of 6.87 m (15.31 m during testing). The location of each grid cell is rated as the most important feature in estimating WTD over most of the CONUS, which might be a surrogate for spatial information. In addition, the uncertainty of the RF model is quantified using quantile regression forests. High uncertainties are generally associated with locations having a shallow WTD. Our study demonstrates that the RF model can produce reasonable WTD estimates over most of the CONUS, providing an alternative to physics-based modeling for modeling large-scale freshwater resources. Since the CONUS covers many different hydrologic regimes, the RF model trained for the CONUS may be transferrable to other regions with a similar hydrologic regime and limited observations.

Continental Scale Hydrostratigraphy: Basin-Scale Testing of Alternative Data-Driven Approaches.

Integrated hydrological modeling is an effective method for understanding interactions between parts of the hydrologic cycle, quantifying water resources, and furthering knowledge of hydrologic processes. However, these models are dependent on robust and accurate datasets that physically represent spatial characteristics as model inputs. This study evaluates multiple data-driven approaches for estimating hydraulic conductivity and subsurface properties at the continental-scale, constructed from existing subsurface dataset components. Each subsurface configuration represents upper (unconfined) hydrogeology, lower (confined) hydrogeology, and the presence of a vertical flow barrier. Configurations are tested in two large-scale U.S. watersheds using an integrated model. Model results are compared to observed streamflow and steady state water table depth (WTD). We provide model results for a range of configurations and show that both WTD and surface water partitioning are important indicators of performance. We also show that geology data source, total subsurface depth, anisotropy, and inclusion of a vertical flow barrier are the most important considerations for subsurface configurations. While a range of configurations proved viable, we provide a recommended Selected National Configuration 1 km resolution subsurface dataset for use in distributed large-and continental-scale hydrologic modeling.