Analysis of the effect of in-class writing on the learning of function concepts in college algebra

This study examined the effects of in-class writing to learn mathematics on college students in a college algebra course. The students in the two experimental groups wrote explanatory responses to prompts regarding a topic discussed in class the previous day twice a week for eight weeks. The teacher read and responded to all writing assignments the next day. The two control groups spent the time discussing additional examples as a class. All other aspects of the course were held constant for the 209 students in the study;The first goal of the study was to investigate the effect of the in-class writing on mathematics achievement. The second goal was to investigate the effect of the in-class writing on the students\u27 attitude toward Mathematics; A third goal was to investigate whether the in-class writing treatment would be differentially effective for some students more than others based on previous mathematics achievement, length of time since the last math class, or self reported study habits;Findings of the study showed that the in-class writing treatment was differentially effective on the attitudes of low achievement students. The low achievement writing students had significantly more positive attitudes toward mathematics at the end of the study than the low achievement nonwriting students. Also there was a significant interaction for the treatment x time since the last mathematics class. The students in the writing group who had not taken a math class for 1.5 years or more had significantly better achievement scores than those in the control group who had not recently completed a math course. These two findings may have practical implications for making mathematics accessible to more students through the use of writing assignments. In general, the study did not find a significant effect for either attitude or achievement for the writing groups

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Phenotypic expansion of CACNA1C-associated disorders to include isolated neurological manifestations

International audiencePurpose:CACNA1C encodes the alpha-1-subunit of a voltage-dependent L-type calcium channel expressed in human heart and brain. Heterozygous variants in CACNA1C have previously been reported in association with Timothy syndrome and long QT syndrome. Several case reports have suggested that CACNA1C variation may also be associated with a primarily neurological phenotype.Methods:We describe 25 individuals from 22 families with heterozygous variants in CACNA1C, who present with predominantly neurological manifestations.Results:Fourteen individuals have de novo, nontruncating variants and present variably with developmental delays, intellectual disability, autism, hypotonia, ataxia, and epilepsy. Functional studies of a subgroup of missense variants via patch clamp experiments demonstrated differential effects on channel function in vitro, including loss of function (p.Leu1408Val), neutral effect (p.Leu614Arg), and gain of function (p.Leu657Phe, p.Leu614Pro). The remaining 11 individuals from eight families have truncating variants in CACNA1C. The majority of these individuals have expressive language deficits, and half have autism.Conclusion:We expand the phenotype associated with CACNA1C variants to include neurodevelopmental abnormalities and epilepsy, in the absence of classic features of Timothy syndrome or long QT syndrome