Narrative framing may increase human suboptimal choice behavior.

Under certain conditions, multiple nonhuman species have been observed engaging in choice behavior that resulted in less food earned when compared to the amount of food that was available to be earned over the course of a session. This phenomenon is particularly strong in pigeons, but has also been observed in rats and nonhuman primates. Conversely, human participants have demonstrated a propensity to choose more optimally. However, human participants do not exclusively choose the alternative associated with more reinforcement. Framing a task in a real-world narrative has been effective in improving problem-solving on other tasks such as the Wason Four-Card problem. The present study gave human participants a choice task with either abstract stimuli or with a real-world narrative. In addition, participants were given terminal stimuli that were either predictive or unpredictive of reinforcement. Thus, participants were assigned to one of four conditions: Abstract Predictive, Abstract Unpredictive, Narrative Predictive, or Narrative Unpredictive. In contrast to the improved performance on the Wason Four-Card task, the current study found no evidence that the addition of a real-world narrative improved optimal choice performance. Rather, it may have interfered with optimal choice selection in that participants who received the narrative and unpredictive terminal stimuli were at chance performance at the end of the experimental session. Conversely, participants in the Abstract Unpredictive, Abstract Predictive, and Narrative Predictive conditions all demonstrated a preference for the optimal alternative. Possible mechanisms for these findings and future directions are discussed.

Human Choice Predicted by Obtained Reinforcers, Not by Reinforcement Predictors.

Macphail (1985) proposed that "intelligence" should not vary across vertebrate species when contextual variables are accounted for. Focusing on research involving choice behavior, the propensity for choosing an option that produces stimuli that predict the presence or absence of reinforcement but that also results in less food over time can be examined. This choice preference has been found multiple times in pigeons (Stagner and Zentall, 2010; Zentall and Stagner, 2011; Laude et al., 2014) and has been likened to gambling behavior demonstrated by humans (Zentall, 2014, 2016). The present experiments used a similarly structured task to examine adult human preferences for reinforcement predictors and compared findings to choice behavior demonstrated by children (Lalli et al., 2000), monkeys (Smith et al., 2017; Smith and Beran, 2020), dogs (Jackson et al., 2020), rats (Chow et al., 2017; Cunningham and Shahan, 2019; Jackson et al., 2020), and pigeons (Roper and Zentall, 1999; Stagner and Zentall, 2010). In Experiment 1, adult human participants showed no preference for reinforcement predictors. Results from Experiment 2 suggest that not only were reinforcement predictors not preferred, but that perhaps reinforcement predictors had no effect at all on choice behavior. Results from Experiments 1 and 2 were further assessed using a generalized matching equation, the findings from which support that adult human choice behavior in the present research was largely determined by reinforcement history. Overall, the present results obtained from human adult participants are different than those found from pigeons in particular, suggesting that further examination of Macphail (1985) hypothesis is warranted.

Modeling-dependent protein characterization of the rice aldehyde dehydrogenase (ALDH) superfamily reveals distinct functional and structural features.

The completion of the rice genome sequence has made it possible to identify and characterize new genes and to perform comparative genomics studies across taxa. The aldehyde dehydrogenase (ALDH) gene superfamily encoding for NAD(P)(+)-dependent enzymes is found in all major plant and animal taxa. However, the characterization of plant ALDHs has lagged behind their animal- and prokaryotic-ALDH homologs. In plants, ALDHs are involved in abiotic stress tolerance, male sterility restoration, embryo development and seed viability and maturation. However, there is still no structural property-dependent functional characterization of ALDH protein superfamily in plants. In this paper, we identify members of the rice ALDH gene superfamily and use the evolutionary nesting events of retrotransposons and protein-modeling-based structural reconstitution to report the genetic and molecular and structural features of each member of the rice ALDH superfamily in abiotic/biotic stress responses and developmental processes. Our results indicate that rice-ALDHs are the most expanded plant ALDHs ever characterized. This work represents the first report of specific structural features mediating functionality of the whole families of ALDHs in an organism ever characterized.

Sampling and recruitment in multilevel studies among marginalized urban populations: the IMPACT studies.

Illicit drug use in urban settings is a major public health problem. A range of individual level factors are known to influence drug use and its consequences, and a number of recent studies have suggested that the neighborhood in which an individual lives may also play a role. However, studies seeking to identify neighborhood-level determinants of drug use, particularly among marginalized urban populations, need to overcome significant challenges, particularly in the area of sampling and recruitment. One key issue is defining functional neighborhoods that are relevant to local residents. Another arises from the need to sample a representative or even a diverse population when studying marginalized groups such as illicit drug users. These are common problems that raise particular challenges when both need to be addressed in the same study. For example, many sampling approaches for neighborhood-level studies have included some form of random sample of households, but this may systematically overlook marginalized populations. On the other hand, the sampling approaches commonly used in studies of hidden populations such as chain referral, snow ball, and more recently, respondent-driven sampling, typically expand beyond a geographic "neighborhood." We describe the organization and rationale for the IMPACT Studies in New York City as a case illustration on how such issues may be addressed.

Ecstasy use among Hispanic and black substance users in New York City.

Surveillance data suggests that use of ecstasy in the U.S. is predominantly among white adolescent and young adults. To investigate ecstasy use among substance users in New York City we added questions to ongoing efforts to recruit heroin and cocaine users. Of 715 participants recruited, 58.3% were injection drug users (IDUs). The median age was 32 (range 17-64), 76.4% were male, 49.0% were currently homeless, 62.4% were Hispanic, 27.3% were black, and 34.5% were born outside the United States. Overall, 23.4% used ecstasy in their lifetime and 11.9% had used in the last-6 months. In multivariate logistic regression, correlates of lifetime ecstasy use included younger age, being born in the U.S., and current homelessness. We observed a significant interaction between injection drug use and race where, compared to black non-IDUs, Hispanic non-IDUs, and white IDUs were significantly more likely to have a history of lifetime ecstasy use while black IDUs were significantly less likely. These findings are limited to persons who use other drugs, but suggest that further investigation of ecstasy use in minority populations is warranted.

Drug use frequency among street-recruited heroin and cocaine users in Harlem and the Bronx before and after September 11, 2001.

We determined if illicit drug use frequency changes after a disaster by comparing drug use frequency in two street-recruited samples of heroin and cocaine users, ages 15-40 years. The users were interviewed between July 11 and November 11 and divided into before- and after-September 11th groups for analysis. The before and after groups were similar in the mean number of days of drug use per month (sniff cocaine 6.8 days vs. 9.4 days, respectively, P =.17; snorted heroin 13.9 vs. 14.0, respectively, P =.96; smoked crack 16.9 vs. 15.6, respectively, P =.96; and smoked marijuana 17.5 vs. 15.3, respectively, P =.36) and in the proportion of daily users: sniffed cocaine 10% versus 17%, respectively (P =.28); snorted heroin 47% versus 40%, respectively (P =.91); smoked crack 33% versus 37%, respectively (P =.68); and smoked marijuana 47% versus 40%, respectively (P =.41). Among street-recruited heroin and cocaine users in Harlem and the Bronx, the frequency of drug use did not increase following the events of September 11, 2001.

Variability in the incidence of human immunodeficiency virus, hepatitis B virus, and hepatitis C virus infection among young injecting drug users in New York City.

Cohort studies of young (aged 18-30 years) injecting drug users recruited in 1997-1999 in the Harlem and Lower East Side areas of New York City, New York, were used to assess the incidence of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV). The authors found that HIV incidence was low at both sites: 0.8/100 person-years at the Harlem site and 0/100 person-years at the Lower East Side site. In contrast, HBV incidence was moderate (12.2/100 person-years) at the Harlem site and high (30.7/100 person-years) at the Lower East Side site. Similarly, HCV incidence was moderate (9.3/100 person-years) at the Harlem site and high (34.0/100 person-years) at the Lower East Side site. Results show that high rates of HBV and HCV transmission do not imply high rates of HIV transmission, even within an area of high HIV seroprevalence.