A simple microscopy assay to teach the processes of phagocytosis and exocytosis

Phagocytosis and exocytosis are two cellular processes involving membrane dynamics. While it is easy to understand the purpose of these processes, it can be extremely difficult for students to comprehend the actual mechanisms. As membrane dynamics play a significant role in many cellular processes ranging from cell signaling to cell division to organelle renewal and maintenance, we felt that we needed to do a better job of teaching these types of processes. Thus, we developed a classroom-based protocol to simultaneously study phagocytosis and exocytosis in Tetrahymena pyriformis. In this paper, we present our results demonstrating that our undergraduate classroom experiment delivers results comparable with those acquired in a professional research laboratory. In addition, students performing the experiment do learn the mechanisms of phagocytosis and exocytosis. Finally, we demonstrate a mathematical exercise to help the students apply their data to the cell. Ultimately, this assay sets the stage for future inquiry-based experiments, in which the students develop their own experimental questions and delve deeper into the mechanisms of phagocytosis and exocytosis.     

Impact of online support for teachers’ open-ended questioning in pre-k science activities

We examined the effects of teacher supports in enhancing teachers’ open-ended questioning in pre-k activities. The blended teacher supports included online video demonstrations of questioning techniques and companion workshop activities. Twenty-five teachers received the blended supports while the control group did not. The data consisted of classroom video observations, teacher surveys, and teachers’ access time to teacher supports. Our quantitative analyses revealed that the treatment group teachers used more open-ended questions than the control group teachers. The students in the treatment group used a greater number of different words and complex sentences than those in the control group.     

The componential model of reading: predicting first grade reading performance of culturally diverse students from ecological, psychological, and cognitive factors assessed at kindergarten entry

This study, framed by the component model of reading (CMR), examined the relative importance of kindergarten-entry predictors of first grade reading performance. Specifically, elements within the ecological domain included dialect, maternal education, amount of preschool, and home literacy; elements within the psychological domain included teacher-reported academic competence, social skills, and behavior; and elements within the cognitive domain included initial vocabulary, phonological, and morpho-syntactic skills, and alphabetic and word recognition skills. Data were obtained for 224 culturally diverse kindergarteners (58% Black, 34% White, and 8% Hispanic or other; 58% received free or reduced-price lunch) from a larger study conducted in seven predominantly high poverty schools (n = 20 classrooms) in a midsized city school district in northern Florida. Results from a hierarchical multiple regression (with variables in the ecological domain entered first, followed by the psychological and cognitive domains) revealed a model that explained roughly 56% of the variance in first grade reading achievement, using fall-of-kindergarten predictors. Letter-word reading and morpho-syntactic skill were the strongest significant predictors. The findings largely support the CMR model as a means to understand individual differences in reading acquisition and, in turn, to support data-based instructional decisions for a wider range of children.     

Math fluency is etiologically distinct from untimed math performance, decoding fluency, and untimed reading performance: evidence from a twin study

The authors examined whether math fluency was independent from untimed math and from reading using 314 pairs of school-aged twins drawn from the Western Reserve Reading and Math Projects. Twins were assessed through a 90-min home visit at approximately age 10 and were reassessed in their homes approximately 1 year later. Results suggested that the shared environment and genetics influenced the covariance among math fluency, untimed math measures, and reading measures. However, roughly two thirds of the variance in math fluency was independent from untimed math measures and reading, including reading fluency. The majority of this independent variance was the result of genetic factors that were longitudinally stable across two measurement occasions. These results suggest that math fluency, although related to other math measures, may also be a genetically distinct dimension of mathematics performance.     

The role of motor experience in understanding action function: the case of the precision grasp

Recent evidence suggests adults and infants selectively attend to features of action, such as how a hand contacts an object. The current research investigated whether this bias stems from infants' processing of the functional consequences of grasps: understanding that different grasps afford different future actions. A habituation paradigm assessed 10-month-old infants' (N = 62) understanding of the functional consequences of precision and whole-hand grasps in others' actions, and infants' own precision grasping abilities were also assessed. The results indicate infants understood the functional consequences of another's grasp only if they could perform precision grasps themselves. These results highlight a previously unknown aspect of early action understanding, and deepen our understanding of the relation between motor experience and cognition.     

Quantile Regression in the Study of Developmental Sciences

Linear regression analysis is one of the most common techniques applied in developmental research, but only allows for an estimate of the average relations between the predictor(s) and the outcome. This study describes quantile regression, which provides estimates of the relations between the predictor(s) and outcome, but across multiple points of the outcome's distribution. Using data from the High School and Beyond and U.S. Sustained Effects Study databases, quantile regression is demonstrated and contrasted with linear regression when considering models with: (a) one continuous predictor, (b) one dichotomous predictor, (c) a continuous and a dichotomous predictor, and (d) a longitudinal application. Results from each example exhibited the differential inferences which may be drawn using linear or quantile regression.     

Relations among home literacy environment,child characteristics and print knowledge for preschool children with language impairment

To contribute to the modest body of work examining the home literacy environment (HLE) and emergent literacy outcomes for children with disabilities, this study addressed two aims: (a) to determine the unique contributions of the HLE on print knowledge of preschool children with language impairment and (b) to identify whether specific child characteristics (oral language ability, print interest) moderated these relations. The sample consisted of 119 preschool children with language impairment. HLE was conceptualised as frequency of storybook reading and literacy teaching during book reading. Frequency of storybook reading was a unique predictor of print knowledge, which is consistent with research on children with typical language. Literacy teaching did not predict print knowledge, which diverges from research on children with typical language. No interactions between the HLE and child characteristics were significant, but language ability and print interest play a role in understanding individual differences in literacy development.     

Researching Race Within Educational Psychology Contexts

In this article, we question why race as a sociohistorical construct has not traditionally been investigated in educational psychology research. To do so, we provide a historical discussion of the significance of race as well as present current dilemmas in the exploration of race, including an examination of the incidence and prevalence of race-related constructs in top educational psychology journals. As a means of expanding educational psychology's use of race as a sociohistorical construct, we introduce the concepts of race-focused and race-reimaged constructs. We end the article with suggestions for how we can begin exploring race as a sociohistorical construct in the field of educational psychology, including the need to challenge traditional paradigms and embrace culturally relevant methodologies.     

An ecological analysis of infant neglect by adolescent mothers

To inform efforts to prevent child neglect, we investigated a wide range of risk factors that have been largely unexamined in relation to infant neglect, the most commonly occurring form of child maltreatment. Using an ecological model of child neglect, we assessed the influence of characteristics at the level of the child, the mother, the family, and broader childrearing contexts on adolescent mothers’ likelihood of being a perpetrator in a substantiated case of neglect against their firstborn infants (n = 383, M = 12 months). Several factors were associated with infant neglect by young mothers: median block income, low infant birth weight, maternal smoking, maternal childhood history of neglect and of positive care, intimate partner violence (IPV) perpetrated by either the mother or her partner, and maternal use of mental health services. In multivariate models, income, a maternal childhood history of positive care, IPV by either a mother or her partner, and mental health service usage made significant contributions to the odds that a mother neglected her infant. Our findings suggest that these factors have particular salience to policymakers’ and practitioners’ efforts to identify high risk families and to intervene during the earliest months of life to prevent child neglect.