1,607 research outputs found

    Opposing Effects of Impulsivity and Mindset on Sources of Science Self- 5 Efficacy and STEM Interest in Adolescents

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    Impulsivity has been linked to academic performance in the context of Attention Deficit Hyperactivity Disorder, though its influence on a wider spectrum of students remains largely unexplored, particularly in the context of STEM learning (i.e. science, technology, engineering, and math). STEM learning was hypothesized to be more challenging for impulsive students, since it requires the practice and repetition of tasks as well as concerted attention to task performance. Impulsivity was assessed in a cross-sectional sample of 2,476 students in grades 6-12. Results show impulsivity affects a larger population of students, not limited to students with learning disabilities. Impulsivity was associated with lower sources of science self-efficacy (SSSE) scores, interest in all STEM domains (particularly math), and self-reported STEM skills. The large negative effect observed for impulsivity was opposed by “growth” mindset, which describes a student’s belief in the importance of effort when learning is difficult. Mindset had a large positive effect, which was associated with greater SSSE, STEM interest, and STEM skills. When modeled together, results suggest that mindset interventions may benefit impulsive students who struggle with STEM. Together, these data suggest important interconnected roles for impulsivity and mindset that can influence secondary students’ STEM trajectories

    Behavioral inhibition in mice bred for high vs. low levels of methamphetamine consumption or sensitization

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    Abstract Rationale Research indicates that genetics influence methamphetamine self-administration as well as sensitization to the psychomotor-stimulating effects of methamphetamine (MA). Other studies have suggested that heightened levels of impulsivity, including low levels of behavioral inhibition, are associated with the use of drugs, including MA. Objectives The current study examined whether lines of mice selected for traits associated with a heightened risk of developing MA dependence would also exhibit low levels of drug-naïve inhibition and whether administration of MA would result in different levels of inhibition in animals selected to consume or respond more to MA. Methods A go/no-go task was used to assess inhibition in male and female mice selected for low or high levels of MA consumption or selected for high or low levels of locomotor sensitization to repeated injections of MA. Results Mice selected for MA sensitization differed in false alarms, precue response rates (measures of behavioral inhibition), and also hits (measure of operant responding). Mice selected for MA consumption did not differ in measures of behavioral inhibition, though hits differed. When MA was administered prior to the task, false alarms, precue response rates, and hits decreased for mice from all selected lines. Female high drinking mice were particularly resistant to MA's effects on hits, but not precue response rate or false alarms. Conclusions These data suggest a shared, but complex, genetic association between inhibition processes, general levels of operant responding, and MA sensitization or consumption

    Correlates of weight instability across the lifespan in a population-based sample

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    Research from overweight/obese clinical samples links weight instability to poor health. This study investigated whether negative health outcomes were associated with weight instability in a population-based sample

    An Investigation of a Measure of Twins' Equal Environments

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    Abstract The equal environments assumption, which holds that trait-relevant environments are equally correlated among monozygotic (MZ) and dizygotic (DZ) twin pairs, is essential to twin designs. Violations of this assumption could lead to biased parameter estimates in twin models. A variety of methods and measures have been used to test this assumption. No studies to date have evaluated the measurement invariance of such items or examined the distribution of the underlying equal environments trait. The current study was an investigation of the psychometric properties of a self-report measure of twins' equal environments. Exploratory and confirmatory factor analysis results indicated that items loaded onto ‘child’ and ‘teen’ equal environments factors. Factor loadings and factor variances and their covariance were invariant for MZ and DZ twins; however, DZ twins had significantly lower factor means than MZ twins. Further, these items demonstrated adequate test–retest reliability. Lastly, the child and teen factors may be bimodally distributed, particularly for MZ twin pairs. Measurement invariance issues, as well as distributions of equal environments traits, should be considered when evaluating the equal environments assumption, in order to produce accurate parameter estimates in twin models

    Design choices for observational studies of the effect of exposure on disease incidence.

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    The purpose of this paper is to help readers choose an appropriate observational study design for measuring an association between an exposure and disease incidence. We discuss cohort studies, sub-samples from cohorts (case-cohort and nested case-control designs), and population-based or hospital-based case-control studies. Appropriate study design is the foundation of a scientifically valid observational study. Mistakes in design are often irremediable. Key steps are understanding the scientific aims of the study and what is required to achieve them. Some designs will not yield the information required to realise the aims. The choice of design also depends on the availability of source populations and resources. Choosing an appropriate design requires balancing the pros and cons of various designs in view of study aims and practical constraints. We compare various cohort and case-control designs to estimate the effect of an exposure on disease incidence and mention how certain design features can reduce threats to study validity

    An investigation of weight suppression in a population-based sample of female twins

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    Weight suppression (WS), maintaining a body weight below one’s maximum adult weight, is associated with bingeing, purging and weight gain in clinical samples

    Differences in genotype and virulence among four multidrug-resistant <i>Streptococcus pneumoniae</i> isolates belonging to the PMEN1 clone

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    We report on the comparative genomics and characterization of the virulence phenotypes of four &lt;i&gt;S. pneumoniae&lt;/i&gt; strains that belong to the multidrug resistant clone PMEN1 (Spain&lt;sup&gt;23F&lt;/sup&gt; ST81). Strains SV35-T23 and SV36-T3 were recovered in 1996 from the nasopharynx of patients at an AIDS hospice in New York. Strain SV36-T3 expressed capsule type 3 which is unusual for this clone and represents the product of an in vivo capsular switch event. A third PMEN1 isolate - PN4595-T23 - was recovered in 1996 from the nasopharynx of a child attending day care in Portugal, and a fourth strain - ATCC700669 - was originally isolated from a patient with pneumococcal disease in Spain in 1984. We compared the genomes among four PMEN1 strains and 47 previously sequenced pneumococcal isolates for gene possession differences and allelic variations within core genes. In contrast to the 47 strains - representing a variety of clonal types - the four PMEN1 strains grouped closely together, demonstrating high genomic conservation within this lineage relative to the rest of the species. In the four PMEN1 strains allelic and gene possession differences were clustered into 18 genomic regions including the capsule, the blp bacteriocins, erythromycin resistance, the MM1-2008 prophage and multiple cell wall anchored proteins. In spite of their genomic similarity, the high resolution chinchilla model was able to detect variations in virulence properties of the PMEN1 strains highlighting how small genic or allelic variation can lead to significant changes in pathogenicity and making this set of strains ideal for the identification of novel virulence determinant
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