Teaching meiosis with the DNA triangle framework: A classroom activity that changes how students think about chromosomes

Many biology students struggle to learn about the process of meiosis and have particular difficulty understanding the molecular basis of crossing over and the importance of homologous pairing for proper segregation. To help students overcome these challenges, we designed an activity that uses a newly developed Chromosome Connections Kit® from 3-D Molecular Designs to allow learners to explore meiosis at the molecular level. We took a backwards design approach in constructing an effective classroom activity. We developed evidence-based learning objectives and designed a crossing over activity that targets students\u27 misconceptions and key concepts about meiosis. Assessment questions were designed based on the learning objectives and common student misconceptions. The activity consists of three parts: an interactive introductory video, a model-based activity, and reflection questions. The activity was first beta-tested with a small number of students and revised based on feedback. The revised activity was deployed in a mid-level Cell and Molecular Biology course. Analysis of pre-/post-assessment data from students who completed the activity (n = 83) showed strong learning gains on concepts related to ploidy, homology, segregation, and the mechanism and purpose of crossing over. Additionally, students who participated in the activity outperformed nonparticipants on a Genetics assessment about meiosis the following semester

Web-based Interactive Video Vignettes Create a Personalized Active Learning Classroom for Introducing Big Ideas in Introductory Biology

The typical “flipped classroom” delivers lecture material in video format to students outside of class in order to make space for active learning in class. But why give students passive material at all? We are developing a set of high-quality online educational materials that promote active, hands-on science learning to aid in teaching of core concepts for introductory biology at the college level. Interactive video vignettes (IVVs) incorporate evidence based teaching strategies to address known areas of confusion for entering students. Each IVV includes a live action scenario with undergraduates investigating a biological problem with a realistic experiment that users participate in. Through the course of each 10-20 minute video, users are required to make predictions, answer questions, collect data and draw conclusions. Branching and reflection of previous answers allows each user to have a personalized experience. Research into how students learn with these tools is being used to develop entire modules that will incorporate the IVV as a priming activity to be done as homework, along with suggested activities to be done in class that take the introduced concepts deeper and/or broader

A Close-Up Look at PCR

The Polymerase Chain Reaction (PCR) is a fundamental laboratory technique that allows for the amplification of many copies of a desired DNA target sequence. Despite its prevalence, undergraduate students often have poor comprehension about the underlying molecular mechanisms of PCR and the components necessary to carry out the reaction. We designed an interactive modeling activity to help students visualize the underlying molecular processes of denaturation, annealing, and extension, and to see how PCR parallels in vivo DNA replication. During the activity, students mimic denaturation, annealing, and extension by synthesizing DNA strands from individual nucleotides and primers in the 5’ to 3’ direction. Because they carry out three cycles, students construct and observe the intermediate products that lead to the exponential amplification of the target sequence. Instructors can easily assemble kits from relatively inexpensive foam nucleotide pieces, and the models can be reused indefinitely. Field testing with first and second year undergraduates suggested that students productively interacted with the models to improve their understanding of PCR

Tuning into the Future: Informal Learning and Music Education

When adolescents are engaged in learning, research has shown a decrease in alcohol and drug use, higher retention rates and fewer failures throughout high school, lower rates of depression as well as lower rates of anti-social and criminal behaviours. Attention to student engagement with a priority on 21st century learning skills requires the examination of various pedagogies, including using informal learning practices as the foundation for instruction with adolescents in schools. This pilot project targets Grade 7 to 10 students in two school settings where adolescent engagement is a priority; it examines the viability of implementing informal learning practices within the Canadian context

Chronicles of Oklahoma

Article includes a report on the runes on a stone on Poteau Mountain near Heavener, Oklahoma, interpreting its meaning through the examination of various translations and suggestions of origin

Labour supply and skills demands in fashion retailing

If, as Adam Smith once famously suggested, Britain was a nation of shopkeepers then it is now a nation of shopworkers. Retail is now a significant part of the UK economy, accounting for £256 billion in sales and one-third of all consumer spending (Skillsmart, 2007). It is the largest private sector employer in the UK, employing 3m workers, or 1 in 10 of the working population. For future job creation in the UK economy retail is also similarly prominent and the sector is expected to create a further 250,000 jobs to 2014 (Skillsmart, 2007). The centrality of retail to economic success and job creation is apparent in other advanced economies. For example, within the US, retail sales is the occupation with the largest projected job growth in the period 2004-2014 (Gatta et al., 2009) and in Australia retail accounts for 1 in 6 workers (Buchanan et al., 2003). Within the UK these workers are employed in approximately 290,000 businesses, encompassing large and small organizations and also a number of sub-sectors. This variance suggests that retail should not be regarded as homogenous in its labour demands. Hart et al. (2007) note how skill requirements and the types of workers employed may differ across the sector. This chapter further opens up this point, providing an analysis of the labour supply and skills demands for the sub-sectors of clothing, footwear and leather goods, which are described by Skillsmart (2007: 48) as being 'significant categories in UK retailing'

Induced chromosome deletions cause hypersociability and other features of Williams-Beuren syndrome in mice

The neurodevelopmental disorder Williams-Beuren syndrome is caused by spontaneous similar to 1.5 Mb deletions comprising 25 genes on human chromosome 7q11.23. To functionally dissect the deletion and identify dosage-sensitive genes, we created two half-deletions of the conserved syntenic region on mouse chromosome 5G2. Proximal deletion (PD) mice lack Gtf2i to Limk1, distal deletion (DD) mice lack Limk1 to Fkbp6, and the double heterozygotes (D/P) model the complete human deletion. Gene transcript levels in brain are generally consistent with gene dosage. Increased sociability and acoustic startle response are associated with PD, and cognitive defects with DD. Both PD and D/P males are growth-retarded, while skulls are shortened and brains are smaller in DD and D/P. Lateral ventricle (LV) volumes are reduced, and neuronal cell density in the somatosensory cortex is increased, in PD and D/P. Motor skills are most impaired in D/P. Together, these partial deletion mice replicate crucial aspects of the human disorder and serve to identify genes and gene networks contributing to the neural substrates of complex behaviours and behavioural disorders

TADPOL: A 1.3 mm Survey of Dust Polarization in Star-forming Cores and Regions

We present {\lambda}1.3 mm CARMA observations of dust polarization toward 30 star-forming cores and 8 star-forming regions from the TADPOL survey. We show maps of all sources, and compare the ~2.5" resolution TADPOL maps with ~20" resolution polarization maps from single-dish submillimeter telescopes. Here we do not attempt to interpret the detailed B-field morphology of each object. Rather, we use average B-field orientations to derive conclusions in a statistical sense from the ensemble of sources, bearing in mind that these average orientations can be quite uncertain. We discuss three main findings: (1) A subset of the sources have consistent magnetic field (B-field) orientations between large (~20") and small (~2.5") scales. Those same sources also tend to have higher fractional polarizations than the sources with inconsistent large-to-small-scale fields. We interpret this to mean that in at least some cases B-fields play a role in regulating the infall of material all the way down to the ~1000 AU scales of protostellar envelopes. (2) Outflows appear to be randomly aligned with B-fields; although, in sources with low polarization fractions there is a hint that outflows are preferentially perpendicular to small-scale B-fields, which suggests that in these sources the fields have been wrapped up by envelope rotation. (3) Finally, even at ~2.5" resolution we see the so-called "polarization hole" effect, where the fractional polarization drops significantly near the total intensity peak. All data are publicly available in the electronic edition of this article.Comment: 53 pages, 37 figures -- main body (13 pp., 3 figures), source maps (32 pp., 34 figures), source descriptions (8 pp.). Accepted by the Astrophysical Journal Supplemen