Elucidating Factors Contributing to Dicamba Volatilization by Characterizing Chemical Speciation in Dried Dicamba-Amine Residues.

Dicamba is a semivolatile herbicide that has caused widespread unintentional damage to vegetation due to its volatilization from genetically engineered dicamba-tolerant crops. Strategies to reduce dicamba volatilization rely on the use of formulations containing amines, which deprotonate dicamba to generate a nonvolatile anion in aqueous solution. Dicamba volatilization in the field is also expected to occur after aqueous spray droplets dry to produce a residue; however, dicamba speciation in this phase is poorly understood. We applied Fourier transform infrared (FTIR) spectroscopy to evaluate dicamba protonation state in dried dicamba-amine residues. We first demonstrated that commercially relevant amines such as diglycolamine (DGA) and n,n-bis(3-aminopropyl)methylamine (BAPMA) fully deprotonated dicamba when applied at an equimolar molar ratio, while dimethylamine (DMA) allowed neutral dicamba to remain detectable, which corresponded to greater dicamba volatilization. Expanding the amines tested, we determined that dicamba speciation in the residues was unrelated to solution-phase amine pKa, but instead was affected by other amine characteristics (i.e., number of hydrogen bonding sites) that also correlated with greater dicamba volatilization. Finally, we characterized dicamba-amine residues containing an additional component (i.e., the herbicide S-metolachlor registered for use alongside dicamba) to investigate dicamba speciation in a more complex chemical environment encountered in field applications.

Effects of Halides on Organic Compound Degradation during Plasma Treatment of Brines.

Plasma has been proposed as an alternative strategy to treat organic contaminants in brines. Chemical degradation in these systems is expected to be partially driven by halogen oxidants, which have been detected in halide-containing solutions exposed to plasma. In this study, we characterized specific mechanisms involving the formation and reactions of halogen oxidants during plasma treatment. We first demonstrated that addition of halides accelerated the degradation of a probe compound known to react quickly with halogen oxidants (i.e., para-hydroxybenzoate) but did not affect the degradation of a less reactive probe compound (i.e., benzoate). This effect was attributed to the degradation of para-hydroxybenzoate by hypohalous acids, which were produced via a mechanism involving halogen radicals as intermediates. We applied this mechanistic insight to investigate the impact of constituents in brines on reactions driven by halogen oxidants during plasma treatment. Bromide, which is expected to occur alongside chloride in brines, was required to enable halogen oxidant formation, consistent with the generation of halogen radicals from the oxidation of halides by hydroxyl radical. Other constituents typically present in brines (i.e., carbonates, organic matter) slowed the degradation of organic compounds, consistent with their ability to scavenge species involved during plasma treatment.

Binding of Dissolved Organic Matter to RNA and Protection from Nuclease-Mediated Degradation.

The persistence of RNA in environmental systems is an important parameter for emerging applications, including ecological surveys, wastewater-based epidemiology, and RNA interference biopesticides. RNA persistence is controlled by its rate of biodegradation, particularly by extracellular enzymes, although the specific factors determining this rate have not been characterized. Due to prior work suggesting that nucleic acids-specifically DNA-interact with dissolved organic matter (DOM), we hypothesized that DOM may bind RNA and impede its biodegradation in natural systems. We first adapted a technique previously used to assess RNA-protein binding to differentiate RNA that is bound at all sites by DOM from RNA that is unbound or partially bound by DOM. Results from this technique suggested that humic acids bound RNA more extensively than fulvic acids. At concentrations of 8-10 mgC/L, humic acids were also found to be more effective than fulvic acids at suppressing enzymatic degradation of RNA. In surface water and soil extract containing DOM, RNA degradation was suppressed by 39-46% relative to pH-adjusted controls. Due to the ability of DOM to both bind and suppress the enzymatic degradation of RNA, RNA biodegradation may be slowed in environmental systems with high DOM concentrations, which may increase its persistence.

Sociocultural and structural influences on HIV Pre-Exposure Prophylaxis (PrEP) Engagement and Uptake among African American Young adults.

BACKGROUND: Pre-exposure prophylaxis (PrEP) demonstrates effectiveness in decreasing new cases of HIV. However, few African Americans use PrEP, despite being disproportionately impacted by HIV. Understanding the influence of sociocultural and structural factors on PrEP use among multiple priority groups of African Americans, including but not limited to men who have sex with men, may improve PrEP engagement and uptake. The social ecological model (SEM) as a framework guided the understanding of how these factors operate on multiple levels to influence PrEP use among this population. METHODS: This study derived data from the Afya PrEP study consisting of eleven focus groups (N = 63) with 18-29-year-old African American sexual and gender minority and heterosexual individuals at heightened behavioral vulnerability to HIV. We employed constructivist grounded theory processes to inductively analyze the data. A pooled kappa score of 0.90 indicated excellent inter-rater agreement. RESULTS: Factors impacting PrEP engagement among African American young adults included: (1) Community/social network influences; (2) medical mistrust; (3) stigma; (4) PrEP availability and accessibility, which had two sub-categories: (a) cost and (b) where to obtain PrEP; and (5) PrEP engagement strategies, which had two sub-categories: (a) current AIDS service organizations' PrEP engagement practices and (b) recommended future PrEP engagement strategies. Categories one through three represent sociocultural factors, and categories four and five represent structural factors that influence perceptions and attitudes of African American young adults regarding PrEP. CONCLUSION: Our study highlights sociocultural and structural factors that act as barriers and facilitators to PrEP engagement. The SEM guided the understanding of how these factors operated on multiple levels. One of the sociocultural factors, community/social network influences operated at the interpersonal level of the SEM; the other two, stigma and medical mistrust, operated at the community level. The structural factors (PrEP availability, accessibility, and engagement strategies) operated at the institutional/organizational level. Thus, multi-level interventions are warranted to improve PrEP engagement among various African American young adult priority groups.

Effectiveness of an Immersive Telemedicine Platform for Delivering Diabetes Medical Group Visits for African American, Black and Hispanic, or Latina Women With Uncontrolled Diabetes: The Women in Control 2.0 Noninferiority Randomized Clinical Trial.

BACKGROUND: Medically underserved people with type 2 diabetes mellitus face limited access to group-based diabetes care, placing them at risk for poor disease control and complications. Immersive technology and telemedicine solutions could bridge this gap. OBJECTIVE: The purpose of this study was to compare the effectiveness of diabetes medical group visits (DMGVs) delivered in an immersive telemedicine platform versus an in-person (IP) setting and establish the noninferiority of the technology-enabled approach for changes in hemoglobin A1c (HbA1c) and physical activity (measured in metabolic equivalent of task [MET]) at 6 months. METHODS: This study is a noninferiority randomized controlled trial conducted from February 2017 to December 2019 at an urban safety net health system and community health center. We enrolled adult women (aged ≥18 years) who self-reported African American or Black race or Hispanic or Latina ethnicity and had type 2 diabetes mellitus and HbA1c ≥8%. Participants attended 8 weekly DMGVs, which included diabetes self-management education, peer support, and clinician counseling using a culturally adapted curriculum in English or Spanish. In-person participants convened in clinical settings, while virtual world (VW) participants met remotely via an avatar-driven, 3D VW linked to video teleconferencing. Follow-up occurred 6 months post enrollment. Primary outcomes were mean changes in HbA1c and physical activity at 6 months, with noninferiority margins of 0.7% and 12 MET-hours, respectively. Secondary outcomes included changes in diabetes distress and depressive symptoms. RESULTS: Of 309 female participants (mean age 55, SD 10.6 years; n=195, 63% African American or Black; n=105, 34% Hispanic or Latina; n=151 IP; and n=158 in VW), 207 (67%) met per-protocol criteria. In the intention-to-treat analysis, we confirmed noninferiority for primary outcomes. We found similar improvements in mean HbA1c by group at 6 months (IP: -0.8%, SD 1.9%; VW: -0.5%, SD 1.8%; mean difference 0.3, 97.5% CI -∞ to 0.3; P<.001). However, there were no detectable improvements in physical activity (IP: -6.5, SD 43.6; VW: -9.6, SD 44.8 MET-hours; mean difference -3.1, 97.5% CI -6.9 to ∞; P=.02). The proportion of participants with significant diabetes distress and depressive symptoms at 6 months decreased in both groups. CONCLUSIONS: In this noninferiority randomized controlled trial, immersive telemedicine was a noninferior platform for delivering diabetes care, eliciting comparable glycemic control improvement, and enhancing patient engagement, compared to IP DMGVs. TRIAL REGISTRATION: ClinicalTrials.gov NCT02726425; https://clinicaltrials.gov/ct2/show/NCT02726425.

RNA Hydrolysis at Mineral-Water Interfaces.

As an essential biomolecule for life, RNA is ubiquitous across environmental systems where it plays a central role in biogeochemical processes and emerging technologies. The persistence of RNA in soils and sediments is thought to be limited by enzymatic or microbial degradation, which occurs on timescales that are orders of magnitude faster than known abiotic pathways. Herein, we unveil a previously unreported abiotic pathway by which RNA rapidly hydrolyzes on the timescale of hours upon adsorption to iron (oxyhydr)oxide minerals such as goethite (α-FeOOH). The hydrolysis products were consistent with iron present in the minerals acting as a Lewis acid to accelerate sequence-independent hydrolysis of phosphodiester bonds comprising the RNA backbone. In contrast to acid- or base-catalyzed RNA hydrolysis in solution, mineral-catalyzed hydrolysis was fastest at circumneutral pH, which allowed for both sufficient RNA adsorption and hydroxide concentration. In addition to goethite, we observed that RNA hydrolysis was also catalyzed by hematite (α-Fe2O3) but not by aluminum-containing minerals (e.g., montmorillonite). Given the extensive adsorption of nucleic acids to environmental surfaces, we anticipate previously overlooked mineral-catalyzed hydrolysis of RNA may be prevalent particularly in iron-rich soils and sediments, which must be considered across biogeochemical applications of nucleic acid analysis in environmental systems.

Development and implementation of a novel peer mentoring program for undergraduate nursing students.

OBJECTIVES: Given the dynamic and high-stress environment of nursing education today, the need arose for the development and implementation of a novel peer mentoring program to support undergraduate nursing students. Peer mentoring refers to a network of support in which a more skilled or experienced person serves as a role model for a less skilled person for professional development and personal growth. Peer mentoring provides a support system that encourages self-confidence and increases self-worth for both the mentee and the mentor. The undergraduate student peer mentoring program in a large, Southeastern United States, university-based, 4-year school of nursing was created in response to a desire for more support conveyed by upper-level nursing students. METHODS: A model was developed whereby each incoming nursing student (Semester 1) would be paired with a senior nursing student (Semesters 3, 4, or 5). This mentoring dyad was then assigned to a faculty mentor who ensured that the mentoring relationship was functioning in accordance with established guidelines and provided support to both the student mentee and the student mentor. RESULTS: The first cohort was comprised of 20 mentoring dyads. Subsequent cohorts have ranged from 20 to 45 mentoring dyads. To date, over 300 nursing students have participated in the undergraduate peer mentoring program. Based on feedback from student evaluation surveys, both mentors and mentees appreciate and find value in the program. Approximately 93% of student mentors indicated that they would have appreciated such a program when they were first semester nursing students. CONCLUSION: Some of the challenges of navigating nursing programs are not related to lack of academic aptitude. Rather, other challenges, including lack of social support and soft skills needed to successfully complete the first and second semesters of nursing school. These are critical challenges that a peer mentor could help to meet.

Production of Dichloroacetonitrile from Derivatives of Isoxaflutole Herbicide during Water Treatment.

The herbicide isoxaflutole has the potential to contaminate drinking water directly, as well as upon hydrolyzing to its active form diketonitrile. Diketonitrile also may impact water quality by acting as a precursor for dichloroacetonitrile (DCAN), which is an unregulated but highly toxic disinfection byproduct (DBP). In this study, we investigated the reaction of diketonitrile with free chlorine and chloramine to form DCAN. We found that diketonitrile reacts with free chlorine within seconds but reacts with chloramine on the time scale of hours to days. In the presence of both oxidants, DCAN was generated at yields up to 100%. Diketonitrile reacted fastest with chlorine at circumneutral pH, which was consistent with base-catalyzed halogenation involving the enolate form of diketonitrile present at alkaline pH and electrophilic hypochlorous acid, which decreases in abundance above its pKa (7.5). In contrast, we found that diketonitrile reacts faster with chloramine as pH values decreased, consistent with an attack on the enolate by electrophilic protonated monochloramine that increases in abundance at acidic pH approaching its pKa (1.6). Our results indicate that increasing isoxaflutole use, particularly in light of the recent release of genetically modified isoxaflutole-tolerant crops, could result in greater occurrences of a high-yield DCAN precursor during disinfection.

Permanganate preoxidation affects the formation of disinfection byproducts from algal organic matter.

During harmful algal blooms (HABs), permanganate may be used as a preoxidant to improve drinking water quality by removing algal cells and degrading algal toxins. However, permanganate also lyses algal cells, releasing intracellular algal organic matter (AOM). AOM further reacts with permanganate to alter the abundance of disinfection byproduct (DBP) precursors, which in turn affects DBP formation during disinfection. In this study, we evaluated the impacts of preoxidation by permanganate applied at commonly used doses (i.e., 1-5 mg/L) on DBP generation during chlorination and chloramination of AOM. We found that permanganate preoxidation increased trichloronitromethane (TCNM) formation by up to 3-fold and decreased dichloroacetonitrile (DCAN) formation by up to 40% during chlorination, indicating that permanganate oxidized organic amines in AOM to organic nitro compounds rather than organic nitrile compounds. To test this proposed mechanism, we demonstrated that permanganate oxidized organic amines in known DBP precursors (i.e., tyrosine, tryptophan) to favor the production of TCNM over DCAN during chlorination. Compared to the decreased formation of DCAN during chlorination, permanganate increased DCAN formation by 30-50% during chloramination of AOM. This difference likely arose from monochloramine's ability to react with non-nitrogenous precursors (e.g., organic aldehydes) that formed during permanganate preoxidation of AOM to generate nitrogen-containing intermediates that go on to form DCAN. Our results also showed that permanganate preoxidation favored the formation of dichlorobromomethane (DCBM) over trichloromethane (TCM) during chlorination and chloramination. The increased formation of DBPs, especially nitrogenous DBPs that are more toxic than carbonaceous DBPs, may increase the overall toxicity in finished drinking water when permanganate preoxidation is implemented.

Understanding Influences on Intention to Use Pre-exposure Prophylaxis (PrEP) Among African American Young Adults.

Pre-exposure prophylaxis (PrEP), a potent medication for HIV prevention, shows promise for reducing HIV disparities. However, PrEP is not equitably utilized by all races and ethnicities in the USA. Its uptake is especially low among African Americans, who are disproportionately impacted by HIV. Understanding factors influencing low PrEP uptake among diverse priority groups of African American young adults beyond gender and sexual minority groups (e.g., cisgender heterosexual people) may increase PrEP uptake. Data were from the Afya project, a study examining the use of PrEP for HIV prevention among multiple priority groups of African American young adults at heightened HIV risk, using Theory of Reasoned Action/Theory of Planned Behavior (TRA/TPB) as a theoretical framework. Eleven focus groups (N = 63) were conducted in Louisville, Kentucky from June to November 2018 with African American young adult priority groups (18-29 years old): men who have sex with men, transgender women, and cisgender heterosexual men and women demonstrating heightened sexual risk. Data were analyzed using constructivist grounded theory techniques. PrEP awareness, knowledge, perceived HIV risk and perceived need for PrEP (behavioral beliefs) and adherence beliefs (control beliefs), opinions of others (subjective norms), and confidence in ability to adhere to PrEP (perceived behavior controls) influenced acceptability of PrEP (participants' attitudes) and, in turn, influenced intention to use PrEP either negatively or positively. Thus, understanding factors that create reticence to PrEP use provides useful insight for tailoring outreach interventions towards African American young adults to improve PrEP uptake.

Amine Volatilization from Herbicide Salts: Implications for Herbicide Formulations and Atmospheric Chemistry.

Amines are frequently included in formulations of the herbicides glyphosate, 2,4-D, and dicamba to increase herbicide solubility and reduce herbicide volatilization by producing herbicide-amine salts. Amines, which typically have higher vapor pressures than the corresponding herbicides, could potentially volatilize from these salts and enter the atmosphere, where they may impact atmospheric chemistry, human health, and climate. Amine volatilization from herbicide-amine salts may additionally contribute to volatilization of dicamba and 2,4-D. In this study, we established that amines applied in herbicide-amine salt formulations undergo extensive volatilization. Both dimethylamine and isopropylamine volatilized when aqueous salt solutions were dried to a residue at ∼20 °C, while lower-vapor pressure amines like diglycolamine and n,n-bis-(3-aminopropyl)methylamine did not. However, all four amines volatilized from salt residues at 40-80 °C. Because amine loss typically exceeded herbicide loss, we proposed that neutral amines dominated volatilization and that higher temperatures altered their protonation state and vapor pressure. Due to an estimated 4.0 Gg N/yr applied as amines to major U.S. crops, amine emissions from herbicide-amine salts may be important on regional scales. Further characterization of worldwide herbicide-amine use would enable this contribution to be compared to the 285 Gg N/yr of methylamines emitted globally.

The Overlooked Photochemistry of Iodine in Aqueous Suspensions of Fullerene Derivatives.

Fullerene's low water solubility was a serious challenge to researchers aiming to harness their excellent photochemical properties for aqueous applications. Cationic functionalization of the fullerene cage provided the most effective approach to increase water solubility, but common synthesis practices inadvertently complicated the photochemistry of these systems by introducing iodide as a counterion. This problem was overlooked until recent work noted a potentiation effect which occurred when photosensitizers were used to inactivate microorganisms with added potassium iodide. In this work, several photochemical pathways were explored to determine the extent and underlying mechanisms of iodide's interference in the photosensitization of singlet oxygen by cationic fulleropyrrolidinium ions and rose bengal. Triplet excited state sensitizer lifetimes were measured via laser flash photolysis to probe the role of I- in triplet sensitizer quenching. Singlet oxygen production rates were compared across sensitizers in the presence or absence of I-, SO42-, and other anions. 3,5-Dimethyl-1H-pyrazole was employed as a chemical probe for iodine radical species, such as I·, but none were observed in the photochemical systems. Molecular iodine and triiodide, however, were found in significant quantities when photosensitizers were irradiated in the presence of I- and O2. The formation of I2 in these photochemical systems calls into question the interpretations of prior studies that used I- as a counterion for photosensitizer materials. As an example, MS2 bacteriophages were inactivated here by cationic fullerenes with and without I- present, showing that I- moderately accelerated the MS2 deactivation, likely by producing I2. Production of I2 did not appear to be directly correlated with estimates of 1O2 concentration, suggesting that the relevant photochemical pathways are more complex than direct reactions between 1O2 and I- in the bulk solution. On the basis of the results here, iodine photochemistry may be underappreciated and misunderstood in other environmental systems.

Reducing Readmission of Hospitalized Patients With Depressive Symptoms: A Randomized Trial.

PURPOSE: To determine if hospitalized patients with depressive symptoms will benefit from post-discharge depression treatment with care transition support. METHODS: This is a randomized controlled trial of hospitalized patients with patient health questionnaire-9 score of 10 or more. We delivered the Re-Engineered Discharge (RED) and randomized participants to groups receiving RED-only or RED for Depression (RED-D), a 12-week post-discharge telehealth intervention including cognitive behavioral therapy, self-management support, and patient navigation. Primary outcomes were hospital readmission and reutilization rates at 30 and 90 days post discharge. RESULTS: We randomized 709 participants (353 RED-D, 356 RED-only). At 90 days, 265 (75%) intervention participants had received at least 1 RED-D session (median 4). At 30 days, the intention-to-treat analysis showed no differences between RED-D vs RED-only in hospital readmission (9% vs 10%, incidence rate ratio [IRR] 0.92 [95% CI, 0.56-1.52]) or reutilization (27% vs 24%, IRR 1.14 [95% CI, 0.85-1.54]). The intention-to-treat analysis also showed no differences at 90 days in readmission (28% vs 21%, IRR 1.30 [95% CI, 0.95-1.78]) or reutilization (70% vs 57%, IRR 1.22 [95% CI, 1.01-1.49]). In the as-treated analysis, each additional RED-D session was associated with a decrease in 30- and 90-day readmissions. At 30 days, among 104 participants receiving 3 or more sessions, there were fewer readmissions (3% vs 10%, IRR 0.30 [95% CI, 0.07-0.84]) compared with the control group. At 90 days, among 109 participants receiving 6 or more sessions, there were fewer readmissions (11% vs 21%, IRR 0.52 [95% CI, 0.27-0.92]). Intention-to-treat analysis showed no differences between study groups on secondary outcomes. CONCLUSIONS: Care transition support and post-discharge depression treatment can reduce unplanned hospital use with sufficient uptake of the RED-D intervention.

Metal-Catalyzed Hydrolysis of RNA in Aqueous Environments.

The stability of RNA in aqueous systems is critical for multiple environmental applications including evaluating the environmental fate of RNA interference pesticides and interpreting viral genetic marker abundance for wastewater-based epidemiology. In addition to biological processes, abiotic reactions may also contribute to RNA loss. In particular, some metals are known to dramatically accelerate rates of RNA hydrolysis under certain conditions (i.e., 37 °C or higher temperatures, 0.15-100 mM metal concentrations). In this study, we investigated the extent to which metals catalyze RNA hydrolysis under environmentally relevant conditions. At ambient temperature, neutral pH, and ∼10 µM metal concentrations, we determined that metals that are stronger Lewis acids (i.e., lead, copper) catalyzed single-stranded (ss)RNA, whereas metals that are weaker Lewis acids (i.e., zinc, nickel) did not. In contrast, double-stranded (ds)RNA resisted hydrolysis by all metals. While lead and copper catalyzed ssRNA hydrolysis at ambient temperature and neutral pH values, other factors such as lowering the solution pH and including inorganic and organic ligands reduced the rates of these reactions. Considering these factors along with sub-micromolar metal concentrations typical of environmental systems, we determined that both ssRNA and dsRNA are unlikely to undergo significant metal-catalyzed hydrolysis in most environmental aqueous systems.

The role of RNA processing and regulation in metastatic dormancy.

Tumor dormancy is a major contributor to the lethality of metastatic disease, especially for cancer patients who develop metastases years-to-decades after initial diagnosis. Indeed, tumor cells can disseminate during early disease stages and persist in new microenvironments at distal sites for months, years, or even decades before initiating metastatic outgrowth. This delay between primary tumor remission and metastatic relapse is known as "dormancy," during which disseminated tumor cells (DTCs) acquire quiescent states in response to intrinsic (i.e., cellular) and extrinsic (i.e., microenvironmental) signals. Maintaining dormancy-associated phenotypes requires DTCs to activate transcriptional, translational, and post-translational mechanisms that engender cellular plasticity. RNA processing is emerging as an essential facet of cellular plasticity, particularly with respect to the initiation, maintenance, and reversal of dormancy-associated phenotypes. Moreover, dysregulated RNA processing, particularly that associated with alternative RNA splicing and expression of noncoding RNAs (ncRNAs), can occur in DTCs to mediate intrinsic and extrinsic metastatic dormancy. Here we review the pathophysiological impact of alternative RNA splicing and ncRNAs in promoting metastatic dormancy and disease recurrence in human cancers.

Hematite/selenium disulfide hybrid catalyst for enhanced Fe(III)/Fe(II) redox cycling in advanced oxidation processes.

Regeneration of Fe(II) is a key issue for heterogeneous advanced oxidation processes (AOPs) using iron-based catalysts. Herein, a hybrid catalyst was developed from α-Fe2O3 and SeS2 to enhance the Fe(III)/Fe(II) redox cycling in both hydrogen peroxide (H2O2) system and persulfate (PS) system. The regeneration of Fe(II) was evidenced by the increased Fe(II)/Fe(III) ratio in the used catalyst (205.8% in the H2O2 system or 125.4% in the PS system), compared to 68.4% in the fresh hybrid catalyst Fe/Se-3. Methyl orange was used as a model pollutant to evaluate the degradation performance of the hybrid catalyst. Owing to the promotion of Fe(II) regeneration, Fe/Se-3 achieved a pollutant removal efficiency of 100.0% in 12 min in both systems, significantly higher than that with pure α-Fe2O3 (33.9 ± 3.6% in the H2O2 system or 30.7 ± 2.8% in the PS system). The dominant active species were identified as hydroxyl radicals in the H2O2 system and sulfate radicals in the PS system. In the proposed mechanism, soluble and surface-bound Fe species are provided by α-Fe2O3 to activate H2O2 or PS to radicals, and SeS2 participates in the reactions via Se(IV) reducing Fe(III) to Fe(II) and S atoms being released through protonation to expose more active Se sites.

Herbicide Drift from Genetically Engineered Herbicide-Tolerant Crops.

In recent years, off-target herbicide drift has been increasingly reported to lead to damage to nontarget vegetation in the U.S. These reports have coincided with the widespread adoption of genetically modified crops with new herbicide-tolerance traits. Planting crops with these traits may indirectly lead to increased drift both by increasing the use of the corresponding herbicides and by facilitating their use as postemergence herbicides later in the season. While extensive efforts have aimed to reduce herbicide drift, critical uncertainties remain regarding the physiochemical phenomena that drive the entry of herbicides into the atmosphere as well as the atmospheric processes that may influence short- and long-range transport. Resolving these uncertainties will support the development of effective approaches to reduce herbicide drift.

Examining Factors that Impact Intentions to Use Pre-Exposure Prophylaxis Among African-American Young Adults.

Pre-exposure prophylaxis (PrEP) is a biomedical HIV prevention strategy with potential to reduce racial HIV disparities. However, African-Americans have not received the benefits of PrEP to the same extent as other groups. The theory of planned behavior (TPB) was employed to explain intentions to use PrEP among a sample of African-Americans (age 18-29) in Louisville, Kentucky. Data were derived from the Afya Project, a study examining PrEP-focused HIV prevention for African-American young adults. The sample was developed through respondent-driven sampling and participants (N = 181) completed audio computer-assisted self-interviews assessing demographics and TPB variables. Analysis of variance was used to examine relationships between demographics and PrEP intentions. Linear regressions determined associations between control beliefs, attitudes, norms, and PrEP use intentions. Confidence in using PrEP (p ≤ .0001), perceived HIV risk (p ≤ 0.05), perceived likelihood of acquiring HIV (p ≤ 0.05), and positive norms around PrEP (p ≤ 0.05) were significantly associated with PrEP use intentions. Findings can inform interventions to advance PrEP as a HIV prevention option for African-American populations at higher risk of contracting HIV.