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Purpose: Native Americans and Latinos have higher COVID‐19 infection and mortality rates and may have limited access to diagnostic testing. Home‐based testing may improve access to care in rural and underserved populations. This study tests the effect of community health worker (CHW) support on accessibility, feasibility, and completion of COVID‐19 home testing among Native American and Latino adults living on the Flathead Reservation in Montana and in Yakima Valley, Washington. Methods: A two‐arm, multisite, pragmatic randomized controlled trial was conducted using block randomization stratified by site and participant age. Active arm participants received CHW assistance with online COVID‐19 test kit registration and virtual swabbing support. The passive arm participants received standard‐of‐care support from the kit vendor. Logistic regression modeled the association between study arm and test completion (primary outcome) and between study arm and test completion with return of valid test results (secondary outcome). Responses to posttest surveys and interviews were summarized using deductive thematic analysis. Findings: Overall, 63% of participants (n = 268) completed COVID‐19 tests, and 50% completed tests yielding a valid result. Active arm participants had higher odds of test completion (odds ratio: 1.66, 95% confidence interval [1.01, 2.75]). Differences were most pronounced among adults ≥60 years. Participants cited ease of use and not having to leave home as positive aspects, and transportation and mailing issues as negative aspects of home‐based testing. Conclusions: CHW support led to higher COVID‐19 test completion rates, particularly among older adults. Significant testing barriers included language, educational level, rurality, and test kit issues. [ABSTRACT FROM AUTHOR]

Objective: To determine whether alcohol use leads to prolonged clinical recovery or increased severity of concussion symptoms in National Collegiate Athletic Association (NCAA) athletes. Design: Prospective observational study. Setting: Clinical institutions. Participants: Athletes from the NCAA Concussion Assessment Research and Education consortium who sustained a concussion from 2014 to 2021. Interventions: Athletes were divided into 2 groups, those reporting alcohol use postinjury and those reporting no alcohol use postinjury. Main Outcome Measures: Symptom recovery was evaluated as time (in days) from injury to clearance to return to unrestricted play (days until URTP). Severity of concussion symptoms was assessed using the Standardized Sport Concussion Assessment Tool (SCAT3) symptom severity, headache severity, difficulty concentrating, and difficulty remembering scores. These scores were taken a median of 6.6 [interquartile range (IQR) = 4.0-10] and 6 (IQR = 4.0-9.0) days after injury for those who did and did not consume alcohol postinjury respectively and compared with baseline SCAT3 scores. Results: Four hundred eighty four athletes from the data set had complete data for exposure and outcome. The adjusted mean number of days until URTP for athletes reporting alcohol use postinjury [23.3; 95% confidence interval (CI), 20.0-27.2; days] was incidence rate ratio (IRR) 1.32 (95% CI, 1.12-1.55; P < 0.001) times higher than for athletes who reported no alcohol use postinjury [17.7 (95% CI, 16.1-19.3) days]. Postinjury alcohol was not associated with severity of concussion symptoms (P's < 0.05). Conclusion: Self-reported postinjury alcohol use is associated with prolonged recovery but not severity of concussion symptoms in collegiate athletes. This may inform future clinical recommendations regarding alcohol consumption after concussion. [ABSTRACT FROM AUTHOR]

The nitrogen and oxygen isotopic compositions of nitrate in pore water extracts from unsaturated zone (UZ) core samples and groundwater samples indicate at least four potential sources of nitrate plumes in groundwaters at the USDOE Hanford Site in southcentral Washington. These nitrate sources are microbially produced nitrate from the soil column (delta15N of 4 to 8 o/oo, delta18O of -9 to 2 o/oo), 2) nitrate in buried caliche layers (delta15N of 0 to 8 o/oo, delta18O of -6 to 42 o/oo), 3) nitric acid in low-level disposal waters (delta15N approx. equal to 0 o/oo, delta18O approx. equal to 23 o/oo ), and 4) co-contaminant nitrate in high-level radioactive waste from plutonium processing (delta15N of 8 to 33 o/oo, delta18O of -9 to 7 o/oo). The isotopic compositions of nitrate have been analyzed from 91 groundwater wells with concentrations up to 763 mg/L NO3-. Estimates based on isotopic mixing indicate that even the wells with the highest nitrate concentrations contain at least 30% of nitrate from natural sources in the UZ. These data indicate that major nitrate plumes resulted from flushing nitrate out of the UZ during disposal of low-level wastewater and nitric acid, rather than migration of the nitrate associated with high-level radioactive UZ contamination.

Strontium isotope compositions (87Sr/86Sr) measured in groundwater samples from 273 wells in the Pasco Basin unconfined aquifer below the Hanford Site show large and systematic variations that provide constraints on groundwater recharge, weathering rates of the aquifer host rocks, communication between unconfined and deeper confined aquifers, and vadose zone-groundwater interaction. The impact of millions of cubic meters of wastewater discharged to the vadose zone (103-105 times higher than ambient drainage) shows up strikingly on maps of groundwater 87Sr/86Sr. Extensive access through the many groundwater monitoring wells at the site allows for an unprecedented opportunity to evaluate the strontium geochemistry of a major aquifer, hosted primarily in unconsolidated sediments, and relate it to both long term properties and recent disturbances. Groundwater 87Sr/86Sr increases systematically from 0.707 to 0.712 from west to east across the Hanford Site, in the general direction of groundwater flow, as a result of addition of Sr from the weathering of aquifer sediments and from diffuse drainage through the vadose zone. The lower 87Sr/86Sr groundwater reflects recharge waters that have acquired Sr from Columbia River Basalts. Based on a steady-state model of Sr reactive transport and drainage, there is an average natural drainage flux of 0-1.4 mm/yr near the western margin of the Hanford Site, and ambient drainage may be up to 30 mm/yr in the center of the site assuming an average bulk rock weathering rate of 10-7.5 g/g/yr.

The Hanford Site in southern Washington contains a large proportion of the 250,000 metric tons of nitrate estimated to reside at DOE sites across the USA. Nitrate concentrations >600 mg/L have been reported for Hanford groundwaters, where nitrate commonly accompanies elevated levels of radionuclide contamination. Much of the Hanford nitrate is stored in the vadose zone, where complicated hydrology and poorly understood chemical and biochemical processes lead to uncertain fate and transport. Analysis of the nitrogen and oxygen isotopic composition of nitrate provides a promising method to identify sources and investigate biochemical degradation of nitrate in the subsurface at Hanford. A preliminary investigation of NO3- fate and transport at the Hanford Site focuses on pore water nitrate, extracted by 1:1 sediment to DI water rinses of vadose zone sediments, in a vertical profile through a radionuclide plume at the TX-TY tank farm, and compares these results with transects across major nitrate plumes in the Hanford unconfined aquifer.Until recently, methods for analyzing d15N and d18O of NO3- in waters were unwieldy for routine analyses of dilute groundwaters and pore water extracts from vadose zone sediments; however, Sigman, et al., 2001 (Anal. Chem) and Casciotti, et al., 2002 (Anal. Chem), developed a method using denitrifying bacteria with a truncated enzymatic pathway to generate N2O for analyzing both isotopes simultaneously from NO3- in dilute samples. Our modifications to this method decrease both culture preparation and sample processing times. Culturing time has been reduced to 2-3 days by increasing the initial inoculation volume to 2mL in 100mL. We grow cultures on a bench top and mix by inversion twice daily, instead of growing on a constant shaking unit. These changes have not been shown to affect the cell yield nor the N2O levels in blanks. Secondly, cell preparation for NO3- reduction has been modified to decrease sample processing time. Intense centrifugation was found to be unnecessary and loose pellet formation at a lower g is more than adequate. We found no detectable background level of N2O in the cultures, and have reduced the sample venting time. Lastly, we have found that samples can be injected, cells lysed, and N2O run in the same day with negligible affects to N2O yield and d15N/d18O values.

Numerical simulations of transport and isotope fractionation provide a method to quantitatively interpret vadose zone pore water stable isotope depth profiles based on soil properties, climatic conditions, and infiltration. We incorporate the temperature-dependent equilibration of stable isotopic species between water and water vapor, and their differing diffusive transport properties into the thermodynamic database of the reactive transport code TOUGHREACT. These simulations are used to illustrate the evolution of stable isotope profiles in semiarid regions where recharge during wet seasons disturbs the drying profile traditionally associated with vadose zone pore waters. Alternating wet and dry seasons lead to annual fluctuations in moisture content, capillary pressure, and stable isotope compositions in the vadose zone. Periodic infiltration models capture the effects of seasonal increases in precipitation and predict stable isotope profiles that are distinct from those observed under drying (zero infiltration) conditions. After infiltration, evaporation causes a shift to higher 18O and D values, which are preserved in the deeper pore waters. The magnitude of the isotopic composition shift preserved in deep vadose zone pore waters varies inversely with the rate of infiltration.

Objective: Parkinson's disease (PD) and essential tremor (ET) involve neuroanatomical circuitry that impact frontal lobe functioning, via the striatum and cerebellum, respectively. The aim of this exploratory study was to investigate quantitative and qualitative performance between and within these groups on measures of verbal fluency. Method: Sixty-three PD and 53 ET patients completed neuropsychological testing. Linear regression models with robust variance estimation compared verbal fluency performance between groups related to correct responses and errors. Paired t-tests investigated within group error rates. Results: PD patients gave more correct responses for phonological ( β ̂ =5.3, p=.01) and category fluency ( β ̂ =4.1, p=.01) than ET patients; however, when processing speed was added as a covariate, this attenuated performance on both measures and only phonological fluency remained significant ( β ̂ =4.0, p=.04). There were no statistical differences in error scores between groups. Error rates within groups suggested that PD patients had higher error rates in total errors and perseveration errors on phonological fluency (M = 2.6, p=.00; M = 1.6, p=.00) and higher total errors and set-loss error rates on category switching (M = 5.1, p<.001; M = 4.1, p<.001). ET patients had higher error rate with relation to total errors and set-loss errors on phonological fluency (M = 2.5, p=.00; M = 1.5, p=.02) and category switching (M = 3.9, p=,00; M = 3.9, p<.001). Conclusions: PD patients performed better than ET patients on phonological fluency. PD patients appear to make more perseveration errors on phonological fluency, while ET patients made more set-loss errors. Implications for frontal lobe dysfunction and clinical impact are discussed. [ABSTRACT FROM AUTHOR]