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Castor is a prime industrial crop belonging to a monotypic genus and its genetic improvement depends on creating desired variability in the primary gene pool. This study reports the development of tetraploid castor plants through colchicine treatment. Seeds of three castor genotypes were soaked in aqueous solutions of colchicine with variable concentrations, and the LD50 value was determined. Of 1010 treated field-raised plants, three were identified as potential polyploids based on increases in a guard cell size and reductions in the number of stomata. The putative polyploid plants were selfed and the progeny were subjected to meiotic analysis. All the progeny were found to be tetraploid. The pairing of chromosomes was abnormal with univalent to octavalent configurations during meiosis-I, but the later parts of meiosis were normal. Seasonal variations in pollen fertility indicated the possible role of temperature-sensitive male sterility in causing the sterility in tetraploid plants. The tetraploid plants were phenotypically comparable with their diploid counterparts, but produced substantially bigger seeds. Thus, these tetraploid plants are valuable resources for basic and applied research in castor.
Recent work suggests that antihypertensive medications may be useful as repurposed treatments for mood disorders. Using large-scale linked healthcare data we investigated whether certain classes of antihypertensive, such as angiotensin antagonists (AAs) and calcium channel blockers, were associated with reduced risk of new-onset major depressive disorder (MDD) or bipolar disorder (BD).
Two cohorts of patients treated with antihypertensives were identified from Scottish prescribing (2009–2016) and hospital admission (1981–2016) records. Eligibility for cohort membership was determined by a receipt of a minimum of four prescriptions for antihypertensives within a 12-month window. One treatment cohort (n = 538 730) included patients with no previous history of mood disorder, whereas the other (n = 262 278) included those who did. Both cohorts were matched by age, sex and area deprivation to untreated comparators. Associations between antihypertensive treatment and new-onset MDD or bipolar episodes were investigated using Cox regression.
For patients without a history of mood disorder, antihypertensives were associated with increased risk of new-onset MDD. For AA monotherapy, the hazard ratio (HR) for new-onset MDD was 1.17 (95% CI 1.04–1.31). Beta blockers' association was stronger (HR 2.68; 95% CI 2.45–2.92), possibly indicating pre-existing anxiety. Some classes of antihypertensive were associated with protection against BD, particularly AAs (HR 0.46; 95% CI 0.30–0.70). For patients with a past history of mood disorders, all classes of antihypertensives were associated with increased risk of future episodes of MDD.
There was no evidence that antihypertensive medications prevented new episodes of MDD but AAs may represent a novel treatment avenue for BD.
This study examined the long-term effects of a randomized controlled trial of the Family Check-Up (FCU) intervention initiated at age 2 on inhibitory control in middle childhood and adolescent internalizing and externalizing problems. We hypothesized that the FCU would promote higher inhibitory control in middle childhood relative to the control group, which in turn would be associated with lower internalizing and externalizing symptomology at age 14. Participants were 731 families, with half (n = 367) of the families assigned to the FCU intervention. Using an intent-to-treat design, results indicate that the FCU intervention was indirectly associated with both lower internalizing and externalizing symptoms at age 14 via its effect on increased inhibitory control in middle childhood (i.e., ages 8.5–10.5). Findings highlight the potential for interventions initiated in toddlerhood to have long-term impacts on self-regulation processes, which can further reduce the risk for behavioral and emotional difficulties in adolescence.
Deployment to war is associated with disruptions to emotion regulation and parenting. Using data from a randomized controlled trial, we examined whether fathers with poorer emotion regulation would differentially benefit from the After Deployment, Adaptive Parenting Tools program, a 14-session group-based parenting intervention. Prior analyses of the intervention demonstrated benefits to observed couple parenting and children's adjustment, but not to fathers’ observed parenting. In this study we examined whether intervention effects on fathers’ observed distress avoidance were moderated by baseline emotion regulation, and whether reduced distress avoidance was associated with improved observed parenting and reduced children's internalizing symptoms. A subset of the full randomized controlled trial sample (181 families with a father who had returned from deployment to war in Iraq or Afghanistan, a nondeployed mother, and a target child aged 4–13) completed measures at baseline, 12-months, and 24-months postbaseline. Results indicated that fathers high in baseline emotion regulation difficulties assigned to the intervention group showed reductions in observed distress avoidance at 12 months compared to controls, which were subsequently associated with improvements in observed parenting practices and reductions in children's internalizing symptoms at 24 months. The results suggest a role for personalizing parenting programs for fathers high in emotion dysregulation.
This paper examines the misalignment between modern human society and certain male phenotypes, a misalignment that has been highlighted and explored in great detail in the work of Tom Dishion. We begin by briefly enumerating the ongoing developmental difficulties of many boys and young men and how these difficulties affect them and those around them. We then suggest that the qualities that have been advantageous for men and their families in our earlier evolution but that are often no longer functional in modern society are a source of these problems. Finally, we provide a brief review of prevention programs that can contribute to preventing this type of problematic development and eliciting more prosocial behavior from at-risk boys and men. We conclude with an overview of research and policy priorities that could contribute to reducing the proportion of boys and young men who experience developmental difficulties in making their way in the world.
Maltreatment during childhood is associated with difficult interpersonal relationships throughout the life course. The aim of the current study was to investigate differential pathways from child maltreatment to emerging adult relationship dysfunction. Specifically, we prospectively tested whether child maltreatment initiates a developmental cascade resulting in coercive negative romantic and friend interactions in emerging adulthood via childhood antisocial tendencies and via childhood relational aggression. Utilizing a longitudinal sample of emerging adult participants (N = 392; mean age = 20 years old) who took part in a summer research camp program as children (mean age = 11 years old), results supported pathways via both childhood antisocial behavior and childhood relational aggression. We found specificity within these pathways such that childhood antisocial behavior was a mediator of child maltreatment effects on emerging adult negative romantic interactions, whereas childhood relational aggression was a mediator of child maltreatment effects on emerging adult negative friend interactions. Taken together, results indicate that children exposed to maltreatment face significant interpersonal challenges in emerging adulthood, within both the friend and the romantic domains, and point to distinct childhood pathways to these negative interactions. Our findings are consistent with Dishion's (2016) theoretical framework for understanding the development of coercion in relationships and highlight the criticality of early intervention with maltreating families.
Decades of research have highlighted the significance of parenting in children's development, yet few studies have focused specifically on the development of parental monitoring strategies in diverse families living in at-risk neighborhoods. The current study investigated the development of active (i.e., parental discussions and curfew rules) and passive (i.e., child communication with parents) parental monitoring strategies across different developmental periods (middle childhood and adolescence; Grades 4–5 and 7–11) as well as individual (child, parent), family, and contextual antecedents (measured in kindergarten) of this parenting behavior. Using an ecological approach, this study evaluated longitudinal data from 753 participants in the Fast Track Project, a multisite study directed at the development and prevention of conduct problems in at-risk children. Latent trajectory modeling results identified little to no mean growth in these monitoring strategies over time, suggesting that families living in at-risk environments may engage in consistent levels of monitoring strategies to ensure children's safety and well-being. Findings also identified several kindergarten antecedents of the growth factors of these parental monitoring strategies including (a) early child conduct problems; (b) parental warmth/involvement, satisfaction, and efficacy; and (c) parent–child relationship quality. These predictive effects largely highlighted the important role of early parenting behaviors on later levels of and growth in parental monitoring strategies. These findings have important implications for potential prevention and intervention targets to promote the development of parental monitoring strategies among families living in more at-risk contexts.
In interventions for at-risk children, Tom Dishion strongly exhorted programs that are short term, cost-effective, and delivered in families’ own communities, just as resilience researchers underscore the need for programs that provide ongoing support for children's primary caregivers, and are implementable on a large scale. Presented here are preliminary results on a short-term intervention for mothers, the Authentic Connections Virtual Groups. A previous randomized trial of the in-person version of this program, conducted with mothers at high risk for stress and burnout, showed significant benefits. There had been zero dropouts across the 3-month program, and participants showed significant improvements on psychological indices as well as cortisol, even 3 months after the program ended. In the present study, virtual groups were conducted with five sets of women, all white-collar professionals with highly stressful, exacting careers, and most also primary caregivers of their children. Again, there were zero dropouts. Mean satisfaction ratings were 9.6 of 10, and the Net Promoter Score (promoters vs. detractors) fell in the “world class” range. To illuminate mechanisms of change, participants’ responses to open-ended questions on the groups’ value are presented verbatim. Recurrently mentioned were the development of new, authentic connections and invaluable ongoing support. These results, with the low costs and ease of women's attendance, attest to the value of expanding offerings such as these, toward benefiting even more highly stressed mothers themselves as well as the children for whose care they are responsible.
Smoking is a major cause of worldwide morbidity and mortality. Almost no evidence-based intervention programs are available to help youth quit smoking. We argue that ineffective targeting of peer influence and engagement difficulties are significant barriers to successful youth smoking cessation. To address these barriers, we developed the mobile game intervention HitnRun. A two-armed randomized controlled trial (RCT; n = 144) was conducted and young smokers (Mage = 19.39; SDage = 2.52) were randomly assigned to either play HitnRun or read a psychoeducational brochure. Prior to, directly following the intervention period, and after three-month follow-up, weekly smoking behavior, abstinence rates, intervention dose, and peer- and engagement-related factors were assessed. Results indicated similar reductions in weekly smoking levels and similar abstinence rates for both groups. Yet, we found a dose effect with HitnRun only: The longer participants played HitnRun, the lower their weekly smoking levels were. In the brochure group, a higher dose was related to higher weekly smoking levels at all measurement moments. Exploratory analyses showed the most powerful effects of HitnRun for participants who connected with and were engaged by the intervention. Future work should build on the promising potential of HitnRun by increasing personalization efforts and strengthening peer influence components.
Whether men's and women's reciprocation of their intimate partners’ negative and positive affect during conflictual topic discussions accounted for the association between their trait hostility and perpetration of physical intimate partner violence (IPV) was examined within a dyadic model, using concurrent measurement. The work builds on that of Dr. Tom Dishion regarding hostile and coercive interactions in key relationships on risk outcomes and the importance of moment-by-moment influences in social interactions. Using dynamic development systems theory and a community sample of at-risk men (N = 156) and their female partners, the hypothesis that quicker negative and slower positive affect reactivity would account for physical IPV perpetration beyond trait hostility was tested. Results suggest that, for women, quicker negative affect reactivity partially explains the hostility IPV association, whereas for men, trait hostility of both partners best explained their perpetration of physical IPV. No support was found for positive affect reactivity as a protective relationship process for IPV involvement. Findings are in line with other studies indicating men were less likely to engage in negative reciprocity relative to women. Furthermore, findings highlight how both partners’ individual characteristics, communication patterns, and emotion regulation processes germane to the romantic relationship impact the likelihood of experiencing physical IPV.
Exposure to high levels of postdivorce interparental conflict is a well-documented risk factor for the development of psychopathology, and there is strong evidence of a subpopulation of families for which conflict persists for many years after divorce. However, existing studies have not elucidated differential trajectories of conflict within families over time, nor have they assessed the risk posed by conflict trajectories for development of psychopathology or evaluated potential protective effects of children's coping to mitigate such risk. We used growth mixture modeling to identify longitudinal trajectories of child-reported conflict over a period of six to eight years following divorce in a sample of 240 children. We related the trajectories to children's mental health problems, substance use, and risky sexual behaviors and assessed how children's coping prospectively predicted psychopathology in the different conflict trajectories. We identified three distinct trajectories of conflict; youth in two high-conflict trajectories showed deleterious effects on measures of psychopathology at baseline and the six-year follow-up. We found both main effects of coping and coping by conflict trajectory interaction effects in predicting problem outcomes at the six-year follow-up. The study supports the notion that improving youth's general capacity to cope adaptively is a potentially modifiable protective factor for all children facing parental divorce and that children in families with high levels of postdivorce conflict are a particularly appropriate group to target for coping-focused preventive interventions.
The Early Growth and Development Study (EGDS) is a prospective adoption study of birth parents, adoptive parents and adopted children (n = 561 adoptees). The original sample has been expanded to include siblings of the EGDS adoptees who were reared by the birth mother and assessed beginning at age 7 years (n = 217 biological children), and additional siblings in both the birth and adoptive family homes, recruited when the adoptees were 8–15 years old (n = 823). The overall study aims are to examine how family, peer and contextual processes affect child and adolescent adjustment, and to examine their interplay (mediation, moderation) with genetic influences. Adoptive and birth parents were originally recruited through adoption agencies located throughout the USA following the birth of a child. Assessments are ongoing and occurred in 9 month’s intervals until the adoptees turned 3 years of age, and in 1 to 2 year intervals thereafter through age 15. Data collection includes the following primary constructs: child temperament, behavior problems, mental health, peer relations, executive functioning, school performance and health; birth and adoptive parent personality characteristics, mental health, health, context, substance use, parenting and marital relations; and the prenatal environment. Findings highlight the power of the adoption design to detect environmental influences on child development and provide evidence of complex interactions and correlations between genetic, prenatal environmental and postnatal environmental influences on a range of child outcomes. The study sample, procedures and an overview of findings are summarized and ongoing assessment activities are described.
Tom Dishion, a pioneer in prevention science, was one of the first to recognize the importance of adapting interventions to the needs of individual families. Building towards this goal, we suggest that prevention trials be used to assess baseline target moderated mediation (BTMM), where preventive intervention effects are mediated through change in specific targets, and the resulting effect varies across baseline levels of the target. Four forms of BTMM found in recent trials are discussed including compensatory, rich-get-richer, crossover, and differential iatrogenic effects. A strategy for evaluating meaningful preventive effects is presented based on preventive thresholds for diagnostic conditions, midpoint targets and proximal risk or protective mechanisms. Methods are described for using the results from BTMM analyses of these thresholds to estimate indices of intervention risk reduction or increase as they vary over baseline target levels, and potential cut points are presented for identifying subgroups that would benefit from program adaptation because of weak or potentially iatrogenic program effects. Simulated data are used to illustrate curves for the four forms of BTMM effects and how implications for adaptation change when untreated control group outcomes also vary over baseline target levels.
Adolescent association with deviant and delinquent friends was examined for its roots in coercive parent–teen interactions and its links to functional difficulties extending beyond delinquent behavior and into adulthood. A community sample of 184 adolescents was followed from age 13 to age 27, with collateral data obtained from close friends, classmates, and parents. Even after accounting for adolescent levels of delinquent and deviant behavior, association with deviant friends was predicted by coercive parent–teen interactions and then linked to declining functioning with peers during adolescence and greater internalizing and externalizing symptoms and poorer overall adjustment in adulthood. Results are interpreted as suggesting that association with deviant friends may disrupt a core developmental task—establishing positive relationships with peers—with implications that extend well beyond deviancy-training effects.
Dishion and Patterson's work on the unique role of fathers in the coercive family process showed that fathers' coercion explained twice the variance of mothers' in predicting children's antisocial behavior and how treatment and prevention of coercion and promotion of prosocial parenting can mitigate children's problem behaviors. Using these ideas, we employed a sample of 426 divorced or separated fathers randomly assigned to Fathering Through Change (FTC), an interactive online behavioral parent training program or to a waitlist control. Participating fathers had been separated or divorced within the past 24 months with children ages 4 to 12 years. We tested an intent to treat (ITT) mediation hypothesis positing that intervention-induced changes in child problem behaviors would be mediated by changes in fathers' coercive parenting. We also tested complier average causal effects (CACE) models to estimate intervention effects, accounting for compliers and noncompliers in the treatment group and would-be compliers in the controls. Mediation was supported. ITT analyses showed the FTC obtained a small direct effect on father-reported pre–post changes in child adjustment problems (d = .20), a medium effect on pre–post changes in fathers' coercive parenting (d = .61), and a moderate indirect effect to changes in child adjustment (d = .30). Larger effects were observed in CACE analyses.
One of Tom Dishion's most significant contributions to prevention science was the development of affordable, ecologically valid interventions, such as the Family Check-Up, that screen for child and family risk factors broadly, but concentrate family-specific interventions on those with greatest potential for population impact. In the spirit of this approach, investigators examined effects of a brief, universal postnatal home visiting program on child emergency medical care and billing costs from birth to age 24 months. Family Connects is a community-wide public health intervention that combines identification and alignment of community services and resources with brief, postpartum nurse home visits designed to assess risk, provide supportive guidance, and connect families with identified risk to community resources. Over 18 months, families of all 4,777 resident Durham County, North Carolina, births were randomly assigned based on even or odd birth date to receive a postnatal nurse home visiting intervention or services as usual (control). Independently, 549 of these families were randomly selected and participated in an impact evaluation study. Families, blind to study goals, provided written consent to access hospital administrative records. Results indicate that children randomly assigned to Family Connects had significantly less total emergency medical care (by 37%) through age 24 months, with results observed across almost all subgroups. Examination of billing records indicate a $3.17 decrease in total billing costs for each $1 in program costs. Overall, results suggest that community-wide postpartum support program can significantly reduce population rates of child emergency medical care through age 24 months while being cost-beneficial to communities.
This study revisits the premature autonomy model by examining parents’ use of positive behavior support (PBS) practices on a daily timescale to better understand underlying processes in developmental changes in family disengagement and the implications for adolescent problem behavior and substance use. This study included 151 9th and 10th grade adolescents (61.5% female) and their caregivers, who participated in a baseline assessment, a 21-day daily diary burst, and a 1-year follow-up assessment. Four key findings emerged: (a) on days when parents used more PBS, adolescents felt more close and connected to their caregivers; (b) adolescents who exhibited a larger-magnitude of change in connectedness with caregivers in relation to variation in positive parenting (termed fragile connectedness) were at higher risk for antisocial behavior, deviant peer involvement, and substance use one year later; (c) individual differences in initial levels of antisocial behavior and effortful control accounted for between-person variation in fragile connectedness; and (d) day-level adolescent anger and parent–adolescent conflict predicted within-family variation in parents’ use of PBS. Implications for the premature autonomy model and intervention science are discussed.