Investigating high school students' conceptualizations of the biological basis of learning

Students go to school to learn. How much, however, do students understand about the biological basis of this everyday process? Blackwell et al. (1) demonstrated a correlation between education about learning and academic achievement. Yet there are few studies investigating high school students' conceptions of learning. In this mixed-methods research study, written assessments were administered to 339 high school students in an urban school district after they completed their required biology education, and videotaped interviews were conducted with 15 students. The results indicated that the majority of students know little about the biological basis of learning, even with prompting, and they recall having learned little about it in school. Students appear to believe that people control their own ability to learn, and some have developed personal hypotheses to describe the learning process. On written assessments, 75% of participants demonstrated a nonbiological framework for learning, and, during interviews, 67% of participants revealed misconceptions about the biological basis of learning. Sample quotes of these interviews are included in this report, and the implications of these findings are discussed.     

Septin ring size scaling and dynamics require the coiled-coil region of Shs1p

Septins are conserved GTP-binding proteins that assemble into heteromeric complexes that form filaments and higher-order structures in cells. What directs filament assembly, determines the size of higher-order septin structures, and governs septin dynamics is still not well understood. We previously identified two kinases essential for septin ring assembly in the filamentous fungus Ashbya gossypii and demonstrate here that the septin Shs1p is multiphosphorylated at the C-terminus of the protein near the predicted coiled-coil domain. Expression of the nonphosphorylatable allele shs1-9A does not mimic the loss of the kinase nor does complete truncation of the Shs1p C-terminus. Surprisingly, however, loss of the C-terminus or the predicted coiled-coil domain of Shs1p generates expanded zones of septin assemblies and ectopic septin fibers, as well as aberrant cell morphology. The expanded structures form coincident with ring assembly and are heteromeric. Interestingly, while septin recruitment to convex membranes is increased, septin localization is diminished at concave membranes in these mutants. Additionally, the loss of the coiled-coil leads to increased mobility of Shs1p. These data indicate the coiled-coil of Shs1p is an important negative regulator of septin ring size and mobility, and its absence may make septin assembly sensitive to local membrane curvature.     

Southern Ocean Biogeography of Tintinnid Ciliates of the Marine Plankton

Ciliate microzooplankton are important grazers in most pelagic ecosystems and among them, tintinnids, with their largely species‐specific loricas, allow relatively easy assessment of questions of diversity and distributions. Herein, we present the results of a survey of species records of tintinnids from the Southern Ocean (locations below 40°S) reported in 56 publications yielding 2,047 species records (synonyms included) from 402 locations. The 192 species reported can be parsed into two main groups: 32 endemic Southern Ocean species, known only from 40°S and further south, and a second group of 181 widespread species, forms with extensive geographic ranges extending into the Southern Ocean. Widespread species reported from the Southern Ocean can be further divided into a group of 81 species, each recorded multiple times in the Southern Ocean waters and 70 apparent “stray” species which have only been found but once. The endemic and widespread species of the Southern Ocean show both distinct distributional patterns and morphological differences. The assemblage of Southern Ocean endemics is found mostly within the Antarctic zone delimited by the average location of the Polar Front and contains a relatively large portion of wide‐mouthed forms. We give suggestions for future study.     

Configuration of a high-content imaging platform for hit identification and pharmacological assessment of JMJD3 demethylase enzyme inhibitors

The biological complexity associated with the regulation of histone demethylases makes it desirable to configure a cellular mechanistic assay format that simultaneously encompasses as many of the relevant cellular processes as possible. In this report, the authors describe the configuration of a JMJD3 high-content cellular mechanistic imaging assay that uses single-cell multiparameter measurements to accurately assess cellular viability and the enzyme-dependent demethylation of the H3K27(Me)3 mark by exogenously expressed JMJD3. This approach couples robust statistical analyses with the spatial resolving power of cellular imaging. This enables segregation of expressing and nonexpressing cells into discrete subpopulations and consequently pharmacological quantification of compounds of interest in the expressing population at varying JMJD3 expression levels. Moreover, the authors demonstrate the utility of this hit identification strategy through the successful prosecution of a medium-throughput focused campaign of an 87 500-compound file, which has enabled the identification of JMJD3 cellular-active chemotypes. This study represents the first report of a demethylase high-content imaging assay with the ability to capture a repertoire of pharmacological tools, which are likely both to inform our mechanistic understanding of how JMJD3 is modulated and, more important, to contribute to the identification of novel therapeutic modalities for this demethylase enzyme.     

Behavioral and hormonal consequences of transporting giant pandas from China to the United States

Zoological institutions strive to ensure the welfare of nonhuman animals in captivity. Part of this effort involves reducing the level of distress experienced by an animal to the greatest extent possible. However, some necessary zoo management practices such as transportation induce stress responses. An extensive literature exists concerning the animal welfare implications of road transportation for farm and laboratory animals. There has, however, been little focus on the effects of air transportation on wild animals in captivity. Because many endangered species are transported by air for breeding purposes, it is especially important to study the effects of stress on these species. This study investigated the behavioral and hormonal consequences of transporting 4 giant pandas (2 male-female pairs) by air from China to the United States. An autoregressive test revealed that urinary cortisol measures were highest for 2 subjects, Lun Lun and Tian Tian, during the flight than during the remainder of the 30-day period posttransport (p < .01). No long-term behavioral changes or problems emerged as a result of the transport. The study found that more research is needed to develop a complete understanding of transportation stress and welfare in captive wildlife.     

Regulation of Epidermal Growth Factor Receptor Signaling and Erlotinib Sensitivity in Head and Neck Cancer Cells by miR-7

Elevated expression and activity of the epidermal growth factor receptor (EGFR)/protein kinase B (Akt) signaling pathway is associated with development, progression and treatment resistance of head and neck cancer (HNC). Several studies have demonstrated that microRNA-7 (miR-7) regulates EGFR expression and Akt activity in a range of cancer cell types via its specific interaction with the EGFR mRNA 3′-untranslated region (3′-UTR). In the present study, we found that miR-7 regulated EGFR expression and Akt activity in HNC cell lines, and that this was associated with reduced growth in vitro and in vivo of cells (HN5) that were sensitive to the EGFR tyrosine kinase inhibitor (TKI) erlotinib (Tarceva). miR-7 acted synergistically with erlotinib to inhibit growth of erlotinib-resistant FaDu cells, an effect associated with increased inhibition of Akt activity. Microarray analysis of HN5 and FaDu cell lines transfected with miR-7 identified a common set of downregulated miR-7 target genes, providing insight into the tumor suppressor function of miR-7. Furthermore, we identified several target miR-7 mRNAs with a putative role in the sensitization of FaDu cells to erlotinib. Together, these data support the coordinate regulation of Akt signaling by miR-7 in HNC cells and suggest the therapeutic potential of miR-7 alone or in combination with EGFR TKIs in this disease.