Generation and Performance of R132H Mutant IDH1 Rabbit Monoclonal Antibody.

Isocitrate dehydrogenase 1 (IDH1) gene mutations have been observed in a majority of diffuse astrocytomas, oligodendrogliomas, and secondary glioblastomas, and the mutant IDH1 R132H is detectable in most of these lesions. By specifically targeting the R132H mutation through B-cell cloning, a novel rabbit monoclonal antibody, MRQ-67, was produced that can recognize mutant IDH1 R132H and does not react with the wild type protein as demonstrated by Enzyme-linked immunosorbent assay (ELISA) and Western blotting. Through immunohistochemistry, the antibody is able to highlight neoplastic cells in glioma tissue specimens, and can be used as a tool in glioma subtyping. Immunohistochemistry (IHC) detection of IDH1 mutant protein may also be used to visualize single infiltrating tumor cells in surrounding brain tissue with an otherwise normal appearance.

Onset of particle trapping and release via acoustic bubbles.

Trapping and sorting of micro-sized objects is one important application of lab on a chip devices, with the use of acoustic bubbles emerging as an effective, non-contact method. Acoustically actuated bubbles are known to exert a secondary radiation force (FSR) on micro-particles and stabilize them on the bubble surface, when this radiation force exceeds the external hydrodynamic forces that act to keep the particles in motion. While the theoretical expression of FSR has been derived by Nyborg decades ago, no direct experimental validation of this force has been performed, and the relationship between FSR and the bubble's ability to trap particles in a given lab on a chip device remains largely empirical. In order to quantify the connection between the bubble oscillation and the resultant FSR, we experimentally measure the amplitude of bubble oscillations that give rise to FSR and observe the trapping and release of a single microsphere in the presence of the mean flow at the corresponding acoustic parameters using an acoustofluidic device. By combining well-developed theories that connect bubble oscillations to the acoustic actuation, we derive the expression for the critical input voltage that leads to particle release into the flow, in good agreement with the experiments.

Exploring undergraduates' understanding of photosynthesis using diagnostic question clusters.

We present a diagnostic question cluster (DQC) that assesses undergraduates' thinking about photosynthesis. This assessment tool is not designed to identify individual misconceptions. Rather, it is focused on students' abilities to apply basic concepts about photosynthesis by reasoning with a coordinated set of practices based on a few scientific principles: conservation of matter, conservation of energy, and the hierarchical nature of biological systems. Data on students' responses to the cluster items and uses of some of the questions in multiple-choice, multiple-true/false, and essay formats are compared. A cross-over study indicates that the multiple-true/false format shows promise as a machine-gradable format that identifies students who have a mixture of accurate and inaccurate ideas. In addition, interviews with students about their choices on three multiple-choice questions reveal the fragility of students' understanding. Collectively, the data show that many undergraduates lack both a basic understanding of the role of photosynthesis in plant metabolism and the ability to reason with scientific principles when learning new content. Implications for instruction are discussed.

The development of a conceptual framework and tools to assess undergraduates' principled use of models in cellular biology.

Recent science education reform has been marked by a shift away from a focus on facts toward deep, rich, conceptual understanding. This requires assessment that also focuses on conceptual understanding rather than recall of facts. This study outlines our development of a new assessment framework and tool-a taxonomy- which, unlike existing frameworks and tools, is grounded firmly in a framework that considers the critical role that models play in science. It also provides instructors a resource for assessing students' ability to reason about models that are central to the organization of key scientific concepts. We describe preliminary data arising from the application of our tool to exam questions used by instructors of a large-enrollment cell and molecular biology course over a 5-yr period during which time our framework and the assessment tool were increasingly used. Students were increasingly able to describe and manipulate models of the processes and systems being studied in this course as measured by assessment items. However, their ability to apply these models in new contexts did not improve. Finally, we discuss the implications of our results and the future directions for our research.

Assessing students' ability to trace matter in dynamic systems in cell biology.

College-level biology courses contain many complex processes that are often taught and learned as detailed narratives. These processes can be better understood by perceiving them as dynamic systems that are governed by common fundamental principles. Conservation of matter is such a principle, and thus tracing matter is an essential step in learning to reason about biological processes. We present here multiple-choice questions that measure students' ability and inclination to trace matter through photosynthesis and cellular respiration. Data associated with each question come from students in a large undergraduate biology course that was undergoing a shift in instructional strategy toward making fundamental principles (such as tracing matter) a central theme. We also present findings from interviews with students in the course. Our data indicate that 1) many students are not using tracing matter as a tool to reason about biological processes, 2) students have particular difficulties tracing matter between systems and have a persistent tendency to interconvert matter and energy, and 3) instructional changes seem to be effective in promoting application of the tracing matter principle. Using these items as diagnostic tools allows instructors to be proactive in addressing students' misconceptions and ineffective reasoning.

Lack of effects of Bacillus sphaericus (Vectolex) on nontarget organisms in a mosquito-control program in southeastern Wisconsin: a 3-year study.

A 3-year study (2000-2002) in southeastern Wisconsin was conducted to assess the effects of Bacillus sphaericus applied for mosquito control on nontarget wetland invertebrates. The experimental design consisted of control and treatment sites (that were applied by helicopter with Vectolex CG), each in 2 vegetation habitat types: reed canary grass marsh (Phalaris arundinacea) and cattail marsh (Typha spp.). In each of these areas, a predetermined number of timed (30-sec) D-frame aquatic net samples containing vegetation, detritus, and invertebrates were collected 1 day before spraying and 72 h after spraying to detect for effects. We examined and compared 5 bioassessment measures to determine if there was an effect of B. sphaericus on nontarget organisms during each of the sampling years. The metrics tested were (1) mean taxa richness (the mean number of all taxa), (2) mean diversity (combines taxa richness and abundances in a summary statistic; i.e., Shannon Index [H'I]), (3) Diptera richness (minus mosquitoes) as a proportion of all other taxa richness (Diptera/others richness), (4) Diptera abundance (minus mosquitoes) as a proportion of all other invertebrate abundance (Diptera/others abundance), and (5) functional group changes in percent collector-gatherers, collector-filterers, scrapers, shredders, and predators. When Vectolex was applied during 6 treatments at the labeled dosage rate in the above habitats in Brookfield, WI, no detrimental effects to nontarget organisms could be attributed to this microbial insecticide. Much of the variation in the control vs. treatment and pre vs. post plots was attributed to factors other than the effects of B. sphaericus on nontarget organisms, such as the time of sampling, natural variation that occurs in such diverse habitats as canary grass and cattail marshes, and water depth, which varied among years.