Dilated cardiomyopathy (DCM) is the third most common cause of heart failure, with similar to 70% of DCM cases considered idiopathic. We showed recently, through genetic ablation of the MGAT1 gene, which encodes an essential glycosyltransferase (GIcNAcT1), that prevention of cardiomyocyte hybrid/complex N-glycosylation was sufficient to cause DCM that led to heart failure and early death. Our findings are consistent with increasing evidence suggesting a link between aberrant glycosylation and heart diseases of acquired and congenital etiologies. However, the mechanisms by which changes in glycosylation contribute to disease onset and progression remain largely unknown. Activity and gating of voltage-gated Na+ and K+ channels (Na-v and K-v respectively) play pivotal roles in the initiation, shaping and conduction of cardiomyocyte action potentials (APs) and aberrant channel activity was shown to contribute to cardiac disease. We and others showed that glycosylation can impact Na-v and K-v function; therefore, here, we investigated the effects of reduced cardiomyocyte hybrid/complex N-glycosylation on channel activity to investigate whether chronic aberrant channel function can contribute to DCM. Ventricular cardiomyocytes from MGAT1 deficient (MGAT1KO) mice display prolonged APs and pacing-induced aberrant early re-activation that can be attributed to, at least in part, a significant reduction in K-v expression and activity that worsens over time suggesting heart disease-related remodeling. MGAT1KO Na-v demonstrate no change in expression or maximal conductance but show depolarizing shifts in voltage-dependent gating. Together, the changes in MGAT1KO Na-v and K-v function likely contribute to observed anomalous electrocardiograms and Ca2+ handling. These findings provide insight into mechanisms by which altered glycosylation contributes to DCM through changes in Na-v and K-v activity that impact conduction, Ca2+ handling and contraction. The MGAT1KO can also serve as a useful model to study the effects of aberrant electrical signaling on cardiac function and the remodeling events that can occur with heart disease progression.

This chapter considers the former type of test to reflect metamemory for text, whereas the latter is considered to reflect metacomprehension. As suggested by both theory and empirical findings, accurate metamemory and metacomprehension for text are distinct constructs, rely on different types of judgment cues, and can be impacted in opposite ways by a given manipulation. The chapter provides an overview of effective manipulations specifically for improving metacomprehension. In general, students' ability to accurately monitor their own comprehension of text is quite poor. Several reviews reports average levels of metacomprehension accuracy around 0.27 in baseline conditions without special instructions or activities. The chapter stimulates that literature within a theoretical context and discusses relevant methodological concerns. It describes the differences between measures of monitoring accuracy such as relative versus absolute measures. In addition to using a measure of monitoring accuracy that is sensitive to readers' online experiences, monitoring will theoretically be more effective when the cues that readers use as a basis for their judgments are more diagnostic for predicting comprehension. There is now a substantial body of work that has demonstrated the effectiveness of several types of activities in improving relative metacomprehension accuracy. (PsycInfo Database Record (c) 2024 APA, all rights reserved)

This quantitative study examines the impact of a three-week online organic preparatory course for chemistry undergraduates that is designed to improve student performance in the subsequent organic chemistry course series (N = 1,289). Organic chemistry often serves as a gatekeeper for students pursuing careers in science, technology, engineering, or mathematics (STEM). Because many students are underprepared for the rigorous organic chemistry series, and consequently are at greater risk of failing it, an online preparatory course was offered that emphasized topics that students frequently struggle with when they enter organic chemistry. The average treatment effects of participation in the online preparatory course on students' subsequent organic chemistry course grades were analyzed utilizing inverse-probability weights with regression adjustment. The analyses indicate that participation in the online preparatory course led to an improvement in subsequent organic chemistry course performance of approximately one-third of a letter grade (e.g., C+ to B-). Notably, students typically at-risk in college environments (i.e., low-income students, first-generation college students, underrepresented minorities) showed commensurate gains when compared to their non-at-risk counterparts. Consequently, this study provides an example of a low-cost intervention that can increase student learning and achievement in organic chemistry. In addition, this study contributes to the nascent research base that examines more distal effects of online course participation.

This quantitative synthesis of 448 independent studies including 480,830 families revealed small positive associations (rs = .13 to .23) between parents' naturally occurring involvement in children's schooling and children's academic adjustment (i.e., achievement, engagement, and motivation) that were maintained over time. Parents' involvement was also positively related to children's social (r = .12) and emotional adjustment (r = .17) and negatively related to their delinquency (r = -.15), concurrently. Analyses focusing on children's academic adjustment revealed that different types of involvement (e.g., parents' participation in school events and discussion of school with children) were similarly positively associated with such adjustment. The only exception was that parents' homework assistance was negatively associated with children's achievement (r = -.15), but not engagement (r = .07) or motivation (r = .05). There was little variation due to age, ethnicity, or socioeconomic status in the links between different types of involvement and children's academic adjustment.

This study examines the relations among parental beliefs and practices about mathematics, children's beliefs about mathematics, participants' gender, and family socioeconomic status (SES). The study was conducted in Chile, a country with significant gender gaps in standardized test results in mathematics, with boys receiving significantly higher scores than girls. One hundred eighty Chilean kindergarteners (M age = 5.6 years) of low and high SES completed both implicit and explicit measures of their beliefs about mathematics. Children's mothers and fathers also completed adult versions of these tests, as well as measures of home numeracy practices. This combination of child and parental assessments (both mother and father), including both implicit and explicit measures, provided a wider range of measures than in previous studies. On implicit measures of math-gender stereotypes, boys showed the math = boy stereotype significantly more strongly than girls did. Both fathers and mothers showed this stereotype on both implicit and explicit measures. Fathers also linked me = math (math self-concept) more strongly than mothers on both implicit and explicit measures. Kindergarten girls' implicit math self-concept was explained by a combination of parents' math self-concepts and SES. Taken together, these results show that by 5 years of age children are already developing beliefs about "who does math" in their culture, and that parental beliefs and practices are significantly linked to children's stereotypes and self-concepts about mathematics before they enter formal schooling. © 2018 American Psychological Association.

Elementary school students often lack a conceptual understanding of linear measurement, which is revealed by their poor performance when the object to be measured is not aligned with the start of the ruler. Instead of correctly counting the units that correspond to the object (e.g., inches or centimeters), children often use 1 of 2 incorrect strategies: reading off the number that corresponds to the end of the object (the least-mature, read-off strategy) and counting the hash marks that flank the object (a more mature, but still incorrect, hash-mark strategy). We hypothesized that shifting to a more mature linear measurement strategy would require the ability to inhibit less-mature prepotent responses, such as read-off and hash-mark responses. In the present study, we predicted that children with better inhibitory control would be more likely to improve in their linear measurement strategy use over one year. Participants (n = 317) were in 1st through 3rd grades when they completed a linear measurement task that required measuring objects that were not aligned with the start of the ruler; they also completed an inhibitory control task and control measures (visuospatial working memory, arithmetic calculations, and number line estimation). One year later, they repeated the linear measurement task. Students with higher initial inhibitory control were more likely to adopt a more mature strategy over time. Moreover, inhibitory control was a significant predictor of strategy improvement over and above other cognitive measures, including visuospatial working memory and arithmetic calculation skill.

Children and adults often have difficulties comparing decimal magnitudes. Although individuals attempt to reconcile decimals with prior whole-number and fraction knowledge, conceptual and procedural differences between decimals and prior knowledge of whole numbers and fractions can lead to incorrect strategies. The dynamic strategy choice account has proposed that saliency, recency, prior knowledge, and other factors contribute to strategy use when reasoning about decimals. We experimentally tested this theory using a priming technique to manipulate the saliency of different strategies prior to completion of a decimal magnitude comparison task. We hypothesized that whole-number priming (practicing whole-number comparisons with feedback) would increase whole-number bias in decimal comparisons (treating decimals with more digits as larger in magnitude), whereas fraction priming would increase fraction bias (treating decimals with fewer digits as larger in magnitude). We also explored participants' performance in decimal comparisons after being primed by decimal comparisons with feedback. Sixth to eighth graders (N = 149) and adults (N = 175) were randomly assigned to 1 of 4 priming conditions: whole-number, fraction, decimal, or a control (flanker) task. Participants first completed numerical magnitude comparisons according to their priming condition (or control task) with feedback, then all conditions completed decimal comparisons without feedback. In both children and adults, fraction priming significantly reduced whole-number bias compared with the control. Among children, fraction priming significantly increased fraction bias. Moreover, children's performance in the control and whole-number-priming conditions was characterized by strong whole-number bias, but in the decimal-priming condition, relatively brief feedback substantially improved decimal comparison performance.

This study tested 3 instructor presence features in learning from video lectures: dynamic drawings, eye contact with the camera, and instructor visibility. In 2 experiments, college students watched a video lecture about the human kidney, which consisted of a series of drawings and a spoken explanation from the instructor, and then took a written posttest assessing retention and transfer. In Experiment 1, students viewed a lesson consisting of a spoken explanation coordinated with static, already-produced drawings (static drawings group) or with drawings dynamically created by the instructor (dynamic drawings group), both without the instructor visible. In support of the dynamic drawings hypothesis, a t test indicated the dynamic drawings group significantly outperformed the static drawings group on the posttest (d = .54). In Experiment 2, students viewed 2 new versions of the kidney lesson, in which the instructor was visible on the screen and either did not provide eye contact with the camera (conventional whiteboard group) or did provide eye contact (transparent whiteboard group). In support of the social agency hypothesis, a t test indicated the transparent whiteboard group significantly outperformed the conventional whiteboard group on the posttest (d = .54). Finally, consistent with the instructor visibility hypothesis, analyses comparing the dynamic drawings group and the transparent whiteboard group indicated no significant differences in posttest performance. Overall, these findings suggest that learning from video lectures is enhanced by specific instructor presence features, such as instructor dynamic drawing and instructor eye contact, rather than by merely having the instructor visible on the screen.

Sex differences in the strength of the relations between mathematics anxiety, mathematics attitudes, and mathematics achievement were assessed concurrently in sixth grade (n = 1,091, 545 boys) and longitudinally from sixth to seventh grade (n = 190, 97 boys). Mathematics anxiety was composed of two facets, one associated with evaluations and the other for learning more generally. Girls had higher mathematics anxiety for evaluations than did boys (ds = -.30 to -.52), but not for mathematics learning. In sixth grade, the negative correlation between mathematical competence and mathematics anxiety for evaluations was stronger in girls than in boys. Longitudinally, higher mathematical competence in sixth grade was associated with lower mathematics anxiety for evaluations and better mathematics attitudes in seventh grade for girls but not for boys. The key finding is that adolescent girls' mathematics anxiety and their attitudes toward mathematics are more reflective of their actual mathematical competence than they are for boys. One implication is that relative to boys with low mathematics achievement, girls with low achievement are at higher risk of developing mathematics anxiety and poor attitudes toward mathematics.