423 research outputs found

    The Three-Phase Reading Comprehension Intervention (3-RCI): A Support for Intermediate-Grade Word Callers

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    This article describes results of a reading comprehension intervention for students with adequate decoding but poor comprehension skills. Five teachers and 25 students in grades 3-5 from two rural public schools participated in this naturalistic experimental research study. Teachers met with identified students in a small group setting for 30 intervention sessions. The intervention involved explicit teaching and gradual release of instruction in three phases: metacognitive strategies, comprehension strategies, and peer-led discussions. To measure growth in reading comprehension, the Qualitative Reading Inventory-3 (Leslie & Caldwell, 2001) was administered as the pre- and posttest and analyzed through t-test comparisons. Interactive teaching is characterized by a dynamic flow of instruction with a powerful use of questioning used as a tool to assist students in understanding what they read. Recitative teaching is marked by static interactions that did not change across treatment intervention. Subsequently, the groups receiving the interactive instruction were compared to those receiving recitative instruction, and growth in reading comprehension for each group was compared. While all students gained in reading comprehension, students in the interactive teaching groups gained more in reading comprehension than those in the recitative teaching groups. Instructional implications of this research are presented and discussed, providing suggestions for teaching reading comprehension

    Acceptance of Simulated Oral Rabies Vaccine Baits by Urban Raccoons

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    In summer 1986, a study was conducted to evaluate raccoon (Procyon lotor) acceptance of oral baits that could be used for rabies vaccination, One thousand wax-coated sponge bait cubes were filled with 5 mg of a seromarker (iophenoxic acid), placed in polyethylene bags, and hand-distributed in an 80 ha area within an urban National Park in Washington, D.C. (USA), After 3 wk, target and nontarget animals were trapped and blood samples collected to evaluate bait uptake. Thirty-three of 52 (63%) raccoons had elevated blood iodine levels indicating they had eaten at least one bait, 13 (25%) were negative, and six (12%) had marginal values, These results indicate that sponge baits hand-placed at a density of 12,4/ha can reach a significant proportion of an urban raccoon population. Implications for oral rabies vaccination of raccoons are discussed

    Materials and processes laboratory composite materials characterization task, part 1. Damage tolerance

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    A test run was performed on IM6/3501-6 carbon-epoxy in which the material was processed, machined into specimens, and tested for damage tolerance capabilities. Nondestructive test data played a major role in this element of composite characterization. A time chart was produced showing the time the composite material spent within each Branch or Division in order to identify those areas which produce a long turnaround time. Instrumented drop weight testing was performed on the specimens with nondestructive evaluation being performed before and after the impacts. Destructive testing in the form of cross-sectional photomicrography and compression-after-impact testing were used. Results show that the processing and machining steps needed to be performed more rapidly if data on composite material is to be collected within a reasonable timeframe. The results of the damage tolerance testing showed that IM6/3501-6 is a brittle material that is very susceptible to impact damage

    Functional significance may underlie the taxonomic utility of single amino acid substitutions in conserved proteins

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    We hypothesized that some amino acid substitutions in conserved proteins that are strongly fixed by critical functional roles would show lineage-specific distributions. As an example of an archetypal conserved eukaryotic protein we considered the active site of Ɵ-tubulin. Our analysis identified one amino acid substitutionā€”ĆŸ-tubulin F224ā€”which was highly lineage specific. Investigation of Ɵ-tubulin for other phylogenetically restricted amino acids identified several with apparent specificity for well-defined phylogenetic groups. Intriguingly, none showed specificity for ā€œsupergroupsā€ other than the unikonts. To understand why, we analysed the Ɵ-tubulin Neighbor-Net and demonstrated a fundamental division between core Ɵ-tubulins (plant-like) and divergent Ɵ-tubulins (animal and fungal). F224 was almost completely restricted to the core Ɵ-tubulins, while divergent Ɵ-tubulins possessed Y224. Thus, our specific example offers insight into the restrictions associated with the co-evolution of Ɵ-tubulin during the radiation of eukaryotes, underlining a fundamental dichotomy between F-type, core Ɵ-tubulins and Y-type, divergent Ɵ-tubulins. More broadly our study provides proof of principle for the taxonomic utility of critical amino acids in the active sites of conserved proteins

    UNISOR on-line nuclear orientation facility (UNISOR/NOF)

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    The UNISOR on-line nuclear orientation facility (UNISOR/NOF) consists of a3He-4He dilution refrigerator on line to the isotope separator. Nuclei are implanted directly into a target foil which is soldered to the bottom accessed cold finger of the refrigerator. A 1.5 T superconducting magnet polarizes the ferromagnetic target foils and determines the axis of symmetry. Up to eight gamma detectors can be positioned around the refrigerator, each 9 cm from the target. A unique feature of this system is that the k=4 term in the directional distribution function can be directly and unambigously deduced so that a single solution for the mixing ratio can be found. The first on-line experiment at this facility reported here was a study of the decay of the191Hg and193Hg isotopes. Ā© 1998 J.C. Baltzer A.G., Scientific Publishing Company

    Human mass balance study of the novel anticancer agent ixabepilone using accelerator mass spectrometry

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    Ixabepilone (BMS-247550) is a semi-synthetic, microtubule stabilizing epothilone B analogue which is more potent than taxanes and has displayed activity in taxane-resistant patients. The human plasma pharmacokinetics of ixabepilone have been described. However, the excretory pathways and contribution of metabolism to ixabepilone elimination have not been determined. To investigate the elimination pathways of ixabepilone we initiated a mass balance study in cancer patients. Due to autoradiolysis, ixabepilone proved to be very unstable when labeled with conventional [14C]-levels (100Ā Ī¼Ci in a typical human radio-tracer study). This necessitated the use of much lower levels of [14C]-labeling and an ultra-sensitive detection method, Accelerator Mass Spectrometry (AMS). Eight patients with advanced cancer (3 males, 5 females; median age 54.5 y; performance status 0ā€“2) received an intravenous dose of 70Ā mg, 80 nCi of [14C]ixabepilone over 3Ā h. Plasma, urine and faeces were collected up to 7Ā days after administration and total radioactivity (TRA) was determined using AMS. Ixabepilone in plasma and urine was quantitated using a validated LC-MS/MS method. Mean recovery of ixabepilone-derived radioactivity was 77.3% of dose. Fecal excretion was 52.2% and urinary excretion was 25.1%. Only a minor part of TRA is accounted for by unchanged ixabepilone in both plasma and urine, which indicates that metabolism is a major elimination mechanism for this drug. Future studies should focus on structural elucidation of ixabepilone metabolites and characterization of their activities

    Identifying Compound-Target Associations by Combining Bioactivity Profile Similarity Search and Public Databases Mining

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    Molecular target identification is of central importance to drug discovery. Here, we developed a computational approach, named bioactivity profile similarity search (BASS), for associating targets to small molecules by using the known target annotations of related compounds from public databases. To evaluate BASS, a bioactivity profile database was constructed using 4296 compounds that were commonly tested in the US National Cancer Institute 60 human tumor cell line anticancer drug screen (NCI-60). Each compound was used as a query to search against the entire bioactivity profile database, and reference compounds with similar bioactivity profiles above a threshold of 0.75 were considered as neighbor compounds of the query. Potential targets were subsequently linked to the identified neighbor compounds by using the known targets o

    The PhenX Toolkit: Get the Most From Your Measures

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    The potential for genome-wide association studies to relate phenotypes to specific genetic variation is greatly increased when data can be combined or compared across multiple studies. To facilitate replication and validation across studies, RTI International (Research Triangle Park, North Carolina) and the National Human Genome Research Institute (Bethesda, Maryland) are collaborating on the consensus measures for Phenotypes and eXposures (PhenX) project. The goal of PhenX is to identify 15 high-priority, well-established, and broadly applicable measures for each of 21 research domains. PhenX measures are selected by working groups of domain experts using a consensus process that includes input from the scientific community. The selected measures are then made freely available to the scientific community via the PhenX Toolkit. Thus, the PhenX Toolkit provides the research community with a core set of high-quality, well-established, low-burden measures intended for use in large-scale genomic studies. PhenX measures will have the most impact when included at the experimental design stage. The PhenX Toolkit also includes links to standards and resources in an effort to facilitate data harmonization to legacy data. Broad acceptance and use of PhenX measures will promote cross-study comparisons to increase statistical power for identifying and replicating variants associated with complex diseases and with gene-gene and gene-environment interactions

    Specific Ī²-Tubulin Isotypes Can Functionally Enhance or Diminish Epothilone B Sensitivity in Non-Small Cell Lung Cancer Cells

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    Epothilones are a new class of microtubule stabilizing agents with promising preclinical and clinical activity. Their cellular target is Ī²-tubulin and factors influencing intrinsic sensitivity to epothilones are not well understood. In this study, the functional significance of specific Ī²-tubulin isotypes in intrinsic sensitivity to epothilone B was investigated using siRNA gene knockdown against Ī²II-, Ī²III- or Ī²IVb-tubulins in two independent non-small cell lung cancer (NSCLC) cell lines, NCI-H460 and Calu-6. Drug-treated clonogenic assays showed that sensitivity to epothilone B was not altered following knockdown of Ī²II-tubulin in both NSCLC cell lines. In contrast, knockdown of Ī²III-tubulin significantly increased sensitivity to epothilone B. Interestingly, Ī²IVb-tubulin knockdowns were significantly less sensitive to epothilone B, compared to mock- and control siRNA cells. Cell cycle analysis of Ī²III-tubulin knockdown cells showed a higher percentage of cell death with epothilone B concentrations as low as 0.5 nM. In contrast, Ī²IVb-tubulin knockdown cells displayed a decrease in epothilone B-induced G2-M cell cycle accumulation compared to control siRNA cells. Importantly, Ī²III-tubulin knockdowns displayed a significant dose-dependent increase in the percentage of apoptotic cells upon treatment with epothilone B, as detected using caspase 3/7 activity and Annexin-V staining. Higher concentrations of epothilone B were required to induce apoptosis in the Ī²IVb-tubulin knockdowns compared to control siRNA, highlighting a potential mechanism underlying decreased sensitivity to this agent. This study demonstrates that specific Ī²-tubulin isotypes can influence sensitivity to epothilone B and may influence differential sensitivity to this promising new agent
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