Palmer amaranth, a competitive weed in cotton and soybeans, poses challenges due to its rapid growth, high fertility, and herbicide resistance. Effective management strategies targeting sex ratios could reduce seed production by female plants. Protoporphyrinogen oxidase (PPO-) inhibiting herbicides play a role in the evolving resistance of Amaranthus spp. in the Midwestern US. These herbicides may also affect the male-to-female ratio of Palmer amaranth. A two-year field experiment (2015 and 2016) was conducted in a soybean field in Collinsville, Illinois, evaluating various preemergence and postemergence PPO-inhibiting herbicide treatments. Untreated Palmer amaranth populations exhibited a bias towards females. Pre-emergence application of sulfentrazone and flumioxazin effectively reduced Palmer amaranth density (1.66 plants m-2) throughout the season, while post-emergence applications of fomesafen and lactofen provided limited control (27 and 31 plants m-2). Early-season mortality was high (96 %) among Palmer amaranth seedlings, especially with pyroxasulfone+fluthiacet-methyl treatment. Fomesafen increased female biomass (28.8 %) while reducing male biomass compared to non-treated control. In 2015, pyroxasulfone+fluthiacet-methyl and acetochlor altered the male-to-female sex ratio compared to the non-treated control, with pyroxasulfone+fluthiacet-methyl reducing the proportion of females (-0.11 M:F) and acetochlor slightly increasing the proportion of males (0.03 M:F), though not different from a 1:1 ratio. In 2016, pendimethalin and flumioxazin-2 resulted in a strong female-biased sex ratio, with an almost exclusively female population. In both years, the non-treated control plots (-0.58 and -0.55 M:F) maintained a naturally female-biased sex ratio, deviating significantly from a 1:1 ratio. These findings suggest that specific herbicide treatments can alter the sex ratio.. Understanding sex determination in Palmer amaranth holds promise for developing more effective control strategies in the future.

This study is the first to attempt to isolate a relationship between cognitive activity and equilibration to a Nash Equilibrium. Subjects, while undergoing fMRI scans of brain activity, participated in second price auctions against a single competitor following predetermined strategy that was unknown to the subject. For this auction there is a unique strategy that will maximize the subjects’ earnings, which is also a Nash equilibrium of the associated game theoretic model of the auction. As is the case with all games, the bidding strategies of subjects participating in second price auctions most often do not reflect the equilibrium bidding strategy at first but with experience, typically exhibit a process of equilibration, or convergence toward the equilibrium. This research is focused on the process of convergence.

In the data reported here subjects participated in sixteen auctions, after which all subjects were told the strategy that will maximize their revenues, the theoretical equilibrium. Following that announcement, sixteen more auctions were performed. The question posed by the research concerns the mental activity that might accompany equilibration as it is observed in the bidding behavior. Does brain activation differ between being equilibrated and non-equilibrated in the sense of a bidding strategy? If so, are their differences in the location of activation during and after equilibration? We found significant activation in the frontal pole especially in Brodmann's area 10, the anterior cingulate cortex, the amygdala and the basal forebrain. There was significantly more activation in the basal forebrain and the anterior cingulate cortex during the first sixteen auctions than in the second sixteen. The activity in the amygdala shifted from the right side to the left after the solution was given.

There are two means of changing the expected value of a risk: changing the probability of a reward or changing the reward. Theoretically, the former produces a greater change in expected utility for risk averse agents. This paper uses two formats of a risk preference elicitation mechanism under two decision frames to test this hypothesis. After controlling for decision error, probability weighting, and order effects, subjects, on average, are slightly risk averse and prefer an increase in the expected value of a risk due to increasing the probability over a compensated increase in the reward. There is substantial across-format inconsistency but very little within-format inconsistency at the individual level.

Some economists argue that consumption of publicly visible goods is driven by social status. Making a causal inference about this claim is difficult with observational data. We conduct an experiment in which we vary both whether a purchase of a physical product is publicly visible or kept private and whether the income used for purchase is linked to social status or randomly assigned. Making consumption choices visible leads to a large increase in demand when income is linked to status, but not otherwise. We investigate the characteristics that mediate this effect and estimate its impact on welfare.

There is substantial evidence that risky decision-making involves a stochastic error process. The literature has adopted different approaches to address this issue, however, risk preferences are not uniquely identified by the most popular methods; decision error is not predicted to monotonically decrease with risk aversion. This paper reports the results of an experiment that elicits risk preferences to identify risk averse individuals and evaluates the frequency the stochastically dominant of two lotteries is chosen. Risk averse subjects exhibit a strong preference for dominant lotteries. More importantly, violations are consistent with stochastic decision error that decreases with risk aversion.

We examine motives for ‘overbidding’ in contests between individuals using a “two-headed” approach to decision-making. In “two-headed” contests, subject pairs send suggested bids and messages to a partner. Content analysis of the messages provides insight into an individual’s bidding motives. In addition, we elicit measures of preferences, beliefs, and impulsiveness. We find that beliefs about others’ bids and messages that emphasize winning (i.e., utility of winning) are the most robust predictors of ‘overbidding’. Our results suggest that analyzing communication provides a rich window into an individual’s thought process when making decisions, and can complement insights from elicited values from common decision tasks (Replication materials, including data, do files, and software, are available at https://sites.google.com/view/david-bruner/research).

This paper reports an expansion of the English as a second language (L2) component of the Multilingual Eye Movement Corpus (MECO L2), an international database of eye movements during text reading. While the previous Wave 1 of the MECO project (Kuperman et al., 2023) contained English as a L2 reading data from readers with 12 different first language (L1) backgrounds, the newly collected dataset adds eye-tracking data on English text reading from 13 distinct L1 backgrounds (N = 660) as well as participants’ scores on component skills of English proficiency and information about their demographics and language background and use. The paper reports reliability estimates, descriptive statistics, and correlational analyses as means to validate the expansion dataset. Consistent with prior literature and the MECO Wave 1, trends in the MECO Wave 2 data include a weak correlation between reading comprehension and oculomotor measures of reading fluency and a greater L1-L2 contrast in reading fluency than reading comprehension. Jointly with Wave 1, the MECO project includes English reading data from more than 1,200 readers representing a diversity of native writing systems (logographic, abjad, abugida, and alphabetic) and 19 distinct L1 backgrounds. We provide multiple pointers to new venues of how L2 reading researchers can mine this rich publicly available dataset.

The current study examines the application of the Pediatric-Buccal-Epigenetic (PedBE) clock, designed for buccal epithelial cells, to endothelia. We evaluate the association of PedBE epigenetic age and age acceleration estimated from human umbilical vein endothelial cells (HUVECs) with length of gestation and birthweight in a racially and ethnically diverse sample (analytic sample n = 333). PedBE age was positively associated with gestational age at birth (r = 0.22, p < .001) and infant birth weight (r = 0.20, p < .001). Multivariate models revealed infants with higher birth weight (adjusted for gestational age) had greater PedBE epigenetic age acceleration (b = 0.0002, se = 0.0007, p = 0.002), though this effect was small; findings were unchanged excluding preterm infants born before 37 weeks’ gestation. In conclusion, the PedBE clock may have application to endothelial cells and provide utility as an anchoring sampling point at birth to examine epigenetic aging in infancy.

Comprehending resilience in the face of mental health issues is important, especially for young people who deal with a variety of psychological pressures. This study aims to investigate the co-occurrence of several mental health conditions and the role of resilience as a potential intervention in youth 14–25 years in the Nairobi metropolitan area. We recruited 1,972 youths. The following self-administered instruments were used: resilience (ARM-R), hopelessness (BHS), depression (BDI, PHQ-9), PTSD (HTQ), loneliness (UCLA Loneliness Scale) and suicidality (C-SSRS). Descriptive statistics, Pearson correlation and hierarchical multiple regression analyses were conducted on the data. The key findings are that depression and hopelessness showed a strong negative association with resilience. PTSD and recent suicidal ideation and behavior showed less negative association with resilience. Building resilience is an important intervention for the conditions reported in our study among the youth. This study contributes novel insights into the intersection of multiple psychological stressors and resilience, paving the way for more targeted, integrative mental health interventions.

Effect modification occurs when a covariate alters the relative effectiveness of treatment compared to control. It is widely understood that, when effect modification is present, treatment recommendations may vary by population and by subgroups within the population. Population-adjustment methods are increasingly used to adjust for differences in effect modifiers between study populations and to produce population-adjusted estimates in a relevant target population for decision-making. It is also widely understood that marginal and conditional estimands for non-collapsible effect measures, such as odds ratios or hazard ratios, do not in general coincide even without effect modification. However, the consequences of both non-collapsibility and effect modification together are little-discussed in the literature.

In this article, we set out the definitions of conditional and marginal estimands, illustrate their properties when effect modification is present, and discuss the implications for decision-making. In particular, we show that effect modification can result in conflicting treatment rankings between conditional and marginal estimates. This is because conditional and marginal estimands correspond to different decision questions that are no longer aligned when effect modification is present. For time-to-event outcomes, the presence of covariates implies that marginal hazard ratios are time-varying, and effect modification can cause marginal hazard curves to cross. We conclude with practical recommendations for decision-making in the presence of effect modification, based on pragmatic comparisons of both conditional and marginal estimates in the decision target population. Currently, multilevel network meta-regression is the only population-adjustment method capable of producing both conditional and marginal estimates, in any decision target population.

We examined the association between influenza vaccination policies at acute care hospitals and influenza vaccination coverage among healthcare personnel for the 2021–22 influenza season. Mandatory vaccination and masking for unvaccinated personnel were associated with increased odds of vaccination. Hospital employees had higher vaccination coverage than licensed independent practitioners.