The 1909 Darwin celebration. Reexamining evolution in the light of Mendel, mutation, and meiosis

In June 1909, scientists and dignitaries from 167 different countries gathered in Cambridge to celebrate the hundredth anniversary of Charles Darwin's birth and the fiftieth anniversary of the publication of Origin of Species. The event was one of the most magnificent commemorations in the annals of science. Delegates gathered within the cloisters of Cambridge University not only to honor the "hero" of evolution but also to reassess the underpinnings of Darwinism at a critical juncture. With the mechanism of natural selection increasingly under attack, evolutionary theory was in disarray. Against this backdrop, biologists weighed the impact of several new developments--the rediscovery of Mendel's laws of heredity, de Vriesian mutation theory, and the linkage of sex-cell division (recently named "meiosis") to the mechanism of heredity. The 1909 Darwin celebration thus represents a significant watershed in the history of modem biology that allows historians to assess the status of evolution prior to the advent of the chromosome theory of genetics.     

Use of a mnemonic technique to teach young children foreign language vocabulary

Children 3 to 6 years of age learned simple Spanish vocabulary items using an adaptation of the keyword method of foreign language vocabulary learning. Using this version of the keyword method, the learner remembered a picture of the translation referent of the vocabulary item interacting with the referent of a concrete English word which sounded like part of the foreign word (the keyword). Children who used the keyword method remembered more vocabulary translations than children who were not instructed in keyword method usage.     

The Effects of the Spacing of Test Trials and Study Trials in Paired‐association Learning

The learning effects due to test and study trials after the initial presentation were examined in a paired‐associate learning paradigm. In Experiment 1 both the spacing and retention intervals were systematically varied. The results showed advantages of spacing for both test and study trials. However, the spacing function of test trials interacted significantly with the retention interval. At a short retention interval, the second recall was a decreasing function of spacing and paralleled closely the initial recall. As the retention interval increased, the spacing‐of‐test function assumed an inverted U‐shape. Performance after repeated studies was on the average better than after test trials. Experiment 2 confirmed that when an initial presentation was followed by two test trials, an increasing spacing interval between each successive test trial produced optimal long‐term performance. In the case where a second study trial was coupled with a test trial, a pattern with equal interval length was better than other spacing patterns. The proportion of test trials of the study list was also varied among groups of subjects. A higher proportion of test trials resulted in better final recall.     

Meaningful education for returning-to-school students in a comprehensive upper secondary school in Iceland

Dropout from upper secondary education in Iceland is higher than in the neighboring countries, but varied options to re-enter school have also been on offer. This article focuses on how students, who had returned to a selected upper secondary school after having quit in one or more other schools, benefited from an innovative pedagogical approach used in the school. The article draws upon interviews, in which the interviewees expressed their pleasure with the school, reporting three main assets of its pedagogy: firstly, a supportive school ethos and student–teacher relationships expressed by the ways in which teachers worked, and also in teachers’ views towards students; secondly, an online learning platform, used by all teachers, which the students could use to structure their studies; and thirdly, the use of formative assessment and no final end-of-term examinations. This pedagogy comprises a whole school approach, and the article concludes that such a school culture and practice enables teenagers and young adults to exercise their right to re-enter academic upper secondary education, which prepares for college, rather than directing them to an industry vocational or practical study program they take little or no interest in.     

Redundancy and the cohesion doze

Reading involves simultaneous top-down processing, where the reader applies prior knowledge to the text, and bottom-up processing, where the reader derives meaning from macro-level structures in the text. Text redundancy is central to both. This study investigated the usefulness of using grammatical cohesion to evaluate comprehension on the macro- or discourse-level, as well as on the micro-level. The Cohesion Cloze was used to determine the extent to which 65 native speakers of Hebrew made use of text redundancy or cohesion when reading an English text. According to the categorization of grammatical and lexical cohesion by Halliday and Hasan (1976), blanks were chosen to test students’ recognition of the repetition of a word or its pronoun, a synonym, superordinate, or generalization. Students were directed to fill in the blanks with words already found in the text. Items were analyzed in terms of discourse analysis as relations of cohesion and coherence in the text. Results indicated that there was a relation between anaphora and coherence that contributed to reading difficulty. Cohesive markers were helpful where blanks were multi-determined and there was redundancy of coherence. Passages which focused on a single idea were found easier to fill in than passages containing ideas that were compared and contrasted. Thus shifts in argument. were found to be more difficult to comprehend than a continuous chain of thought.     

Latent Class Analysis in Higher Education: An Illustrative Example of Pluralistic Orientation

Although used frequently in related fields such as K-12 education research, educational psychology, sociology, and social survey research, latent class analysis (LCA) has been infrequently used in higher education. This article provides higher education researchers with a pedagogical application of LCA to classify entering freshmen based on their pluralistic orientation. This study utilized data on entering freshmen at a racially diverse institution on the West coast. LCA was used to estimate latent profile probabilities, classify freshmen into latent classes, and relate latent class probabilities to covariates. The findings indicated that a four-class model was the best fitting model: high pluralistic orientation; high-disposition, low-skill; low-disposition, high-skill; and low pluralistic orientation. Similar to previous research, the findings indicated that the probability of being classified into one group versus the other was dependent upon a student’s race/ethnicity and intended major. This approach can aid college administrators in their program planning and targeted interventions around issues of diversity.     

The Development of Social Networks in Preschool Children

Behavioral observations and sociometric ratings were assessed in separate 3- and 4-year-old child care classes across a two year period. A cross sequential design included three cohorts. Cohort A was observed at age 4, Cohort B at ages 3 and 4 and Cohort C was observed at age 3 yielding two separate cross sectional comparisons and a longitudinal comparison across ages 3 and 4. Social network analyses were used to determine the relation between behavioral measures of social interactions and sociometric ratings, developmental changes in the degree of organization of the social networks in each class, and the degree to which gender was an organizing principle in the social structure of both age groups. In general, correspondence between the behavioral observations and sociometric ratings increased with age and the social structure showed greater cohesion in the 4-year-old class. Gender was an organizing principle in the social structure of the 4-year-old class and became more apparent across time in the 3-year-old class. Implications of the findings for the assessment of sociometric status and for intervention are discussed.     

Behavioral problems among children whose mothers are abused by an intimate partner

OBJECTIVES: To determine the association between children's exposure to maternal intimate partner violence (IPV) and behavior problems as measured by the parent report version of the Child Behavior Checklist (CBCL). METHODS: The study population was comprised of 167 2- to 17-year-old children of Seattle women with police-reported or court-reported intimate partner abuse. The CBCL normative population served as the comparison group. Risk of behavior problems was calculated among the exposed children, in the presence and absence of a history of reported child maltreatment, relative to the normative population. Multiple logistic regression served as the primary method of analysis. RESULTS: Children exposed to maternal IPV were more likely to have borderline to clinical level scores on externalizing (i.e., aggressive, delinquent) behavior (RR=1.6, 95% CI: 1.2, 2.1) and total behavioral problems (RR=1.4, 95% CI: 1.1, 1.9) compared to the CBCL normative sample after adjusting for age and sex. Children who were exposed to maternal IPV and were victims of child maltreatment were more likely to receive borderline to clinical level scores on internalizing (i.e., anxious, depressed) behaviors (RR=2.6, 95% CI: 1.5, 3.6), externalizing (i.e., aggressive, delinquent) behaviors (RR=3.0, 95% CI: 1.9, 4.0) and total behavioral problems (RR=2.1, 95% CI: 1.2, 3.2) compared to the CBCL normative sample after adjusting for age and sex. CONCLUSIONS: Exposure to maternal IPV is significantly associated with child behavioral problems both in the presence and absence of co-occurring child maltreatment. Appropriate attention to the mental health of children living in households with IPV is needed.