Factors Influencing Quality of Team Discussion: Discourse Analysis in an Undergraduate Team-Based Learning Biology Course.

Group activities as part of active-learning pedagogies are thought to be effective in promoting student learning in part because of the quality of discussion they engender in student teams. Not much is known, however, about which instructional factors are most important in achieving productive conversation or how these factors may differ among different collaborative pedagogies. We explored what provokes meaningful group discussions in a university physiology course taught using team-based learning (TBL). We were most interested in discussions that evoke explanations that go beyond statements of basic facts and into disciplinary reasoning. Using transcribed conversations of four randomly selected teams three times throughout the semester, we analyzed three distinct discursive phenomena-conceptual explanations, re-evaluations, and co-construction-that occurred in productive conversations. In this paper, we provide examples from student discussions showing the role of each of these elements in moving students toward conceptual understanding. These phenomena were more likely to occur in response to higher-order questions in Bloom's taxonomy. Preclass preparation and student accountability as part of TBL may be important factors in this finding. We share implications for practice based on our results.

Functionally Significant Features in the 5' Untranslated Region of the ABCA1 Gene and Their Comparison in Vertebrates.

Single nucleotide polymorphisms located in 5' untranslated regions (5'UTRs) can regulate gene expression and have clinical impact. Recognition of functionally significant sequences within 5'UTRs is crucial in next-generation sequencing applications. Furthermore, information about the behavior of 5'UTRs during gene evolution is scarce. Using the example of the ATP-binding cassette transporter A1 (ABCA1) gene (Tangier disease), we describe our algorithm for functionally significant sequence finding. 5'UTR features (upstream start and stop codons, open reading frames (ORFs), GC content, motifs, and secondary structures) were studied using freely available bioinformatics tools in 55 vertebrate orthologous genes obtained from Ensembl and UCSC. The most conserved sequences were suggested as hot spots. Exon and intron enhancers and silencers (sc35, ighg2 cgamma2, ctnt, gh-1, and fibronectin eda exon), transcription factors (TFIIA, TATA, NFAT1, NFAT4, and HOXA13), some of them cancer related, and microRNA (hsa-miR-4474-3p) were localized to these regions. An upstream ORF, overlapping with the main ORF in primates and possibly coding for a small bioactive peptide, was also detected. Moreover, we showed several features of 5'UTRs, such as GC content variation, hairpin structure conservation or 5'UTR segmentation, which are interesting from a phylogenetic point of view and can stimulate further evolutionary oriented research.

Circulating and circular RNAs and the need for rationalization and synthesis of the research spiral.

In this essay, we aim to draw a short comparison between 2 important research topics - circular and circulating RNAs - and show how they are connected. The findings described here in the field of circular RNAs, which are still quite obscured by the rapidly expanding body of knowledge in biology, have added another dimension to our view of the process of gene expression, which is formed by a more complex network of molecule interactions than we previously thought. The term "circulating RNAs" refers to a broad spectrum of RNA fragments originating from different sources, such as physiologically dying cells, sites of inflammation or cancer cells, and fragments floating in human liquid tissues together with other elements. Fragments of nucleic acids circulating in blood are emerging as promising biomarkers in different medical conditions. Interestingly, circular RNAs have been found to be present in human blood and form a fraction of circulating RNAs. In addition to updating readers on these fast-developing areas of biology, we also stress the need for the study of complex networks of molecule interactions as whole structures (in unison with the thoughts of systems biology), as opposed to the trend toward searching for individual key player molecules. Fundamentally, we want to add to the rationalization and synthesis of new research findings in the scientific literature, because this direction is important not only for students, teachers and researchers, but also for the general population.

Interactive Computer Simulations as Pedagogical Tools in Biology Labs.

Student learning in biology may be impaired by instructional environments that emphasize technical methodology over analysis. We hypothesized that time gained by experimenting with accurate computer simulations could be used to engage students in analytical, creative learning. The effects of treatments that combined a week of simulated lab instruction with a week of standard lab instruction in different order (E-to-S and S-to-E) were examined using a controlled experimental design with random assignment of lab sections and hierarchical linear modeling analysis to account for possible clustering within sections. Data from a large sample of students ( N = 515) revealed a significant increase (1.59 SD) in posttest scores for both treatment groups over the control. We posit as a plausible explanation the reinforcement of psychomotor learning due to strong engagement of cognitive processes facilitated by the computer simulation. This study supports a wider use of computer simulations as learning tools in laboratory courses.

The use of porcine corrosion casts for teaching human anatomy.

In teaching and learning human anatomy, anatomical autopsy and prosected specimens have always been indispensable. However, alternative methods must often be used to demonstrate particularly delicate structures. Corrosion casting of porcine organs with Biodur E20® Plus is valuable for teaching and learning both gross anatomy and, uniquely, the micromorphology of cardiovascular, respiratory, digestive, and urogenital systems. Assessments of casts with a stereomicroscope and/or scanning electron microscope as well as highlighting cast structures using color coding help students to better understand how the structures that they have observed as two-dimensional images actually exist in three dimensions, and students found using the casts to be highly effective in their learning. Reconstructions of cast hollow structures from (micro-)computed tomography scans and videos facilitate detailed analyses of branching patterns and spatial arrangements in cast structures, aid in the understanding of clinically relevant structures and provide innovative visual aids. The casting protocol and teaching manual we offer can be adjusted to different technical capabilities and might also be found useful for veterinary or other biological science classes.

Development and Assessment of Modules to Integrate Quantitative Skills in Introductory Biology Courses.

Redesigning undergraduate biology courses to integrate quantitative reasoning and skill development is critical to prepare students for careers in modern medicine and scientific research. In this paper, we report on the development, implementation, and assessment of stand-alone modules that integrate quantitative reasoning into introductory biology courses. Modules are designed to improve skills in quantitative numeracy, interpreting data sets using visual tools, and making inferences about biological phenomena using mathematical/statistical models. We also examine demographic/background data that predict student improvement in these skills through exposure to these modules. We carried out pre/postassessment tests across four semesters and used student interviews in one semester to examine how students at different levels approached quantitative problems. We found that students improved in all skills in most semesters, although there was variation in the degree of improvement among skills from semester to semester. One demographic variable, transfer status, stood out as a major predictor of the degree to which students improved (transfer students achieved much lower gains every semester, despite the fact that pretest scores in each focus area were similar between transfer and nontransfer students). We propose that increased exposure to quantitative skill development in biology courses is effective at building competency in quantitative reasoning.

Heterogeneous expression of the potassium-chloride cotransporter KCC2 in gonadotropin-releasing hormone neurons of the adult mouse.

In mature central neurons, chloride extrusion mediated by the K-Cl cotransporter KCC2 appears to be largely responsible for the Cl(-) driving force that allows gamma-aminobutyric acid(A) (GABA(A)) receptor activation to trigger a hyperpolarization. In its absence, GABA's effect is typically depolarizing and often excitatory. We examined the colocalization of KCC2 and GnRH in adult male and female mice using a combined in situ hybridization-immunofluorescence procedure. We found that KCC2 was localized to approximately 34% of GnRH neurons. This proportion was similar in females and males. However, females exhibited a marked rostrocaudal gradient of colocalization that was not seen in males. By contrast, KCC2 was localized to nearly all vasopressin neurons of the supraoptic nucleus. These results indicate that a substantial fraction of GnRH neurons may be depolarized and excited by GABA(A) receptor activation throughout life, supporting the existence of functionally heterogeneous subpopulations.

Deletion of exon 6 of the neuronal nitric oxide synthase gene in mice results in hypogonadism and infertility.

Nitric oxide (NO) has been recognized as a modulator in reproductive functions, but it is not clear whether NO is required for fertility. The first line of mice deficient in neuronal NO synthase (referred to herein as KN1 mice) reproduce normally. However, residual neuronal NO synthase (nNOS) activity is detected in KN1 mice due to the expression of beta- and gamma-nNOS splice variants. We generated a new line of nNOS knockout mice (KN2) lacking exon 6, which codes for the heme-binding domain of nNOS. KN2 mice are viable, but mated homozygotes do not produce litters, indicating that either one or both sexes are infertile. Male KN2 mice show decreased gonad weights, but sperm counts are normal. KN2 males do not display mating behavior, and consequently do not leave vaginal plugs when housed with wild-type (WT) females. KN2 females show decreased ovary weight, and histology reveals decreased corpus luteum counts. RIAs show that KN2 males have decreased plasma FSH, whereas KN2 females have increased levels of plasma LH and increased hypothalamic GnRH content. Experimental ovarian transplantation suggests that central, rather than ovarian, processes are influenced by nNOS, as KN2 ovaries ovulate at near-normal rates under WT hormonal control, whereas WT ovaries transplanted into KN2 mice have decreased ovulation rates. We observed pyloric stenosis in KN2 mice, but plasma leptin levels are normal, and no ketones are found, indicating that hypogonadism is not a result of malnutrition. We conclude that nNOS is required for normal central hormonal regulation of reproductive function.