In a technology-driven society, screens are being used more than ever. The high rate of electronic media use among children and adolescents begs the question: is screen time harming our youth? The ...current study draws from a nationwide sample of 11,875 participants in the United States, aged 9 to 10 years, from the Adolescent Brain Cognitive Development Study (ABCD Study®). We investigate relationships between screen time and mental health, behavioral problems, academic performance, sleep habits, and peer relationships by conducting a series of correlation and regression analyses, controlling for SES and race/ethnicity. We find that more screen time is moderately associated with worse mental health, increased behavioral problems, decreased academic performance, and poorer sleep, but heightened quality of peer relationships. However, effect sizes associated with screen time and the various outcomes were modest; SES was more strongly associated with each outcome measure. Our analyses do not establish causality and the small effect sizes observed suggest that increased screen time is unlikely to be directly harmful to 9-and-10-year-old children.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
G-quadruplexes (G4s) are noncanonical DNA structures that frequently occur in the promoter regions of oncogenes, such as MYC, and regulate gene expression. Although G4s are attractive therapeutic ...targets, ligands capable of discriminating between different G4 structures are rare. Here, we describe DC-34, a small molecule that potently downregulates MYC transcription in cancer cells by a G4-dependent mechanism. Inhibition by DC-34 is significantly greater for MYC than other G4-driven genes. We use chemical, biophysical, biological, and structural studies to demonstrate a molecular rationale for the recognition of the MYC G4. We solve the structure of the MYC G4 in complex with DC-34 by NMR spectroscopy and illustrate specific contacts responsible for affinity and selectivity. Modification of DC-34 reveals features required for G4 affinity, biological activity, and validates the derived NMR structure. This work advances the design of quadruplex-interacting small molecules to control gene expression in therapeutic areas such as cancer.
Previous research has revealed a moderate and positive correlation between procrastination and impulsivity. However, little is known about why these two constructs are related. In the present study, ...we used behavior-genetics methodology to test three predictions derived from an evolutionary account that postulates that procrastination arose as a by-product of impulsivity: (a) Procrastination is heritable, (b) the two traits share considerable genetic variation, and (c) goal-management ability is an important component of this shared variation. These predictions were confirmed. First, both procrastination and impulsivity were moderately heritable (46% and 49%, respectively). Second, although the two traits were separable at the phenotypic level (r = .65), they were not separable at the genetic level (rgenetic = 1.0). Finally, variation in goal-management ability accounted for much of this shared genetic variation. These results suggest that procrastination and impulsivity are linked primarily through genetic influences on the ability to use high-priority goals to effectively regulate actions.
Executive functions (EFs)-the higher level cognitive abilities that enable us to control our own thoughts and actions-continue to develop into early adulthood, yet no longitudinal study has examined ...their stability during the important life transition from late adolescence to young adulthood. In this twin study (total N = 840 individuals from 424 families), we examined the stability of individual differences in 3 EF components across a 6-year period, from approximately age 17 years (Wave 1) to 23 years (Wave 2). Specifically, we address the following questions: (a) How stable are individual differences in multiple EFs across this time period? and (b) What (genetic and/or environmental) influences affect stability and change in EFs? Results indicated that individual differences in EFs are quite stable across this 6-year period (phenotypic latent variable correlations ranged from 0.86 to 1.0). However, there was evidence for change, particularly in the factor common to multiple EFs (Common EF). Multivariate twin models suggested that stability was due almost entirely to high genetic correlations across time; there was no new genetic variance at Wave 2. Change in Common EF was due to small but significant nonshared environmental influences at Wave 2 (15%). The results suggest that individual differences in EFs are quite heritable and stable by late adolescence, yet are still sensitive to environmental influences.
The author provides a personal perspective on Nick Martin's contributions to behavioral genetics and his role in the workshops on statistical genetics held annually in Boulder. Highlighted are Prof. ...Martin's seminal work on multivariate behavioral genetics, his career-long commitment to the value of the study of twins, and his enthusiastic support of the didactic mission of the 'Boulder workshops'. These contributions and activities continue unabated as we celebrate Prof. Martin's 70th birthday.
•Small associations of rumination with Common executive function (EF).•Anger and Depressive Rumination not differentially associated with EFs.•Independent associations between Common EF, rumination, ...and psychopathology.•Results are inconsistent with rumination as mediator of Common EF–psychopathology association.
Both rumination, a pattern of repetitive, self-focused thought in response to distress, and deficits in executive functions (EFs), a set of cognitive abilities that facilitate higher-order thinking, have transdiagnostic associations with psychopathology. Although empirical studies suggest associations between EFs and rumination, this literature has not examined subtypes of rumination and different components of EFs. It also has not examined whether rumination and EFs explain overlapping variance in psychopathology, which is relevant to theoretical models suggesting that rumination might mediate the EF–psychopathology association.
We used structural equation modeling to examine the association between latent factors for two types of rumination (anger and depressive) and three components of EF (a Common EF factor, and factors specific to updating working memory and shifting mental sets) and whether they independently relate to internalizing and externalizing psychopathology in a population sample of 764 young adults (mean age 23 years) from the Colorado Longitudinal Twin Study.
Depressive and Anger Rumination showed small correlations with a Common EF factor (rs = –.09 to –.11). Anger Rumination and Common EF ability were associated with independent variance in externalizing psychopathology, whereas Depressive Rumination, but not Common EF, was associated with internalizing psychopathology.
Examination of cross-sectional relations in a population sample led to low symptom endorsement for psychopathology and necessitated examination of lifetime, rather than past-year, psychopathology.
Inconsistent with mediation hypotheses, Common EF abilities and rumination are correlated yet largely independent constructs that both predict psychopathology.
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