Examining the Connection between Classroom Technology and Student Engagement

Technological pedagogy is being relied upon more-and-more as a way to address the growing needs of higher education. This study investigated the use of a tool designed with the specific purpose of student engagement in a large classroom. The tool allows students to post to a community based discussion in a manner similar to a Twitter feed. Despite engaging in a community dialogue, findings suggest that as usage of the technology went up a student’s sense of community learning went down. This result prompted the authors to consider how this tool was utilized in the classroom. We close with a warning that adoption of a novel technology alone does not produce a greater sense of community learning

A Statistical Mechanical Problem in Schwarzschild Spacetime

We use Fermi coordinates to calculate the canonical partition function for an ideal gas in a circular geodesic orbit in Schwarzschild spacetime. To test the validity of the results we prove theorems for limiting cases. We recover the Newtonian gas law subject only to tidal forces in the Newtonian limit. Additionally we recover the special relativistic gas law as the radius of the orbit increases to infinity. We also discuss how the method can be extended to the non ideal gas case.Comment: Corrected an equation misprint, added four references, and brief comments on the system's center of mass and the thermodynamic limi

30 Doradus - a Template for "Real Starbursts"?

30 Doradus is the closest massive star forming region and the best studied template of a starburst. In this conference paper we first summarize the properties of 30 Doradus and its stellar core, R136. We discuss the effects of insufficient spatial resolution and cluster density profiles on dynamical mass estimates of super star clusters, and show that their masses can be easily overestimated by a factor of ten or more. From a very simple model, with R136-like clusters as representative building blocks, we estimate typical luminosities of the order 10^11 L_o for starburst galaxies.Comment: To be published in "Starbursts: From 30 Doradus to Lyman Break Galaxies", eds. R. de Grijs & R.M. Gonzalez Delgad

Transduction of a cellular oncogene: The genesis of Rous sarcoma virus

The oncogene of Rous sarcoma virus (v-src) arose by transduction of a cellular gene (c-src). In an effort to explore the mechanism of transduction, we have identified the splice acceptor site used in the genesis of mRNA for v-src, shown that an equivalent site is used in the splicing of mRNA for c-src, and determined the nucleotide sequence from the boundaries of homology between v-src and c-src. Our data indicate that (i) only a portion of c-src is represented within v-src, (ii) the leftward recombination between the genome of the transducing virus and c-src occurred in an intron of the cellular gene, (iii) v-src is in part a spliced version of the corresponding portion of c-src, and (iv) nucleotide sequences represented once in the genome of the transducing virus become duplicated to flank v-src. These findings indicate that the first step in transduction is probably recombination between DNA forms of the transducing viral genome and c-src and otherwise support the prevailing model for transduction by retroviruses. The carboxyl termini of the proteins encoded by v-src and c-src differ appreciably. An unidentified domain of 127 or 128 nucleotides is located at different positions in the genomes of two strains of RSV and gives evidence of being a foreign element that entered the viral genomes by genetic transposition independent of the transduction of src

Development of a Student Self-Reported Instrument to Assess Course Reform

This study examines the development and implementation of a survey-based instrument assessing the effectiveness of a course redesign initiative focused on student centeredness at a large midwestern university in the United States. Given the scope of the reform initiative under investigation in this study, researchers developed an instrument called the Classroom Experience Questionnaire (CEQ), which was administered to students enrolled in redesigned courses. Early findings demonstrate strong construct validity and internal reliability of the CEQ instrument as well as concurrent validity between the CEQ and observation data gathered in concert with self-report data. The authors conclude that in the absence of trained classroom observers, the developed student self-report protocol can serve as a useful tool for measuring the constructivist orientation of pedagogy and student-centered nature of the learning environment in a higher education setting

The yellow European eel (Anguilla anguilla L.) may adopt a sedentary lifestyle in inland freshwaters

We analysed the movements of the growing yellow phase using a long-term mark–recapture programme on European eels in a small catchment (the Frémur, France). The results showed that of the yellow eels (>200 mm) recaptured, more than 90% were recaptured at the original marking site over a long period before the silvering metamorphosis and downstream migration. We conclude that yellow European eels >200 mm may adopt a sedentary lifestyle in freshwater area, especially in small catchment

Leak Rate Quantification Method for Gas Pressure Seals with Controlled Pressure Differential

An enhancement to the pressure decay leak rate method with mass point analysis solved deficiencies in the standard method. By adding a control system, a constant gas pressure differential across the test article was maintained. As a result, the desired pressure condition was met at the onset of the test, and the mass leak rate and measurement uncertainty were computed in real-time. The data acquisition and control system were programmed to automatically stop when specified criteria were met. Typically, the test was stopped when a specified level of measurement uncertainty was attained. Using silicone O-ring test articles, the new method was compared with the standard method that permitted the downstream pressure to be non-constant atmospheric pressure. The two methods recorded comparable leak rates, but the new method recorded leak rates with significantly lower measurement uncertainty, statistical variance, and test duration. Utilizing this new method in leak rate quantification, projects will reduce cost and schedule, improve test results, and ease interpretation between data sets

Prolonged enoxaparin therapy compared with standard-of-care antithrombotic therapy in opiate-treated patients undergoing primary percutaneous coronary intervention

A novel enoxaparin regimen consisting of intra-arterial bolus (0.75 mg/kg) followed by intravenous infusion (0.75 mg/kg/6 hours) has been developed as a possible solution to the delayed absorption of oral P2Y12 inhibitors in opiate-treated ST-elevation myocardial infarction (STEMI) patients undergoing primary angioplasty. We aimed to study the feasibility of this regimen as an alternative to standard-of-care treatment (SOC) with unfractionated heparin ± glycoprotein IIb/IIIa antagonist (GPI). One hundred opiate-treated patients presenting with STEMI and accepted for primary angioplasty were randomized (1:1) to either enoxaparin or SOC. Fifty patients were allocated enoxaparin (median age 61, 40% females) and 49 allocated SOC (median age 62, 22% females). One developed stroke before angiography and was withdrawn. One SOC patient had a gastrointestinal bleed resulting in 1 g drop in hemoglobin and early cessation of GPI infusion. Two enoxaparin patients had transient minor bleeding: one transient gingival bleed and one episode of coffee ground vomit with no hemoglobin drop or hemodynamic instability. Two SOC and no enoxaparin group patients had acute stent thrombosis. These preliminary data support further study of this novel 6-hour enoxaparin regimen in opiate-treated PPCI patients

The Aeromonas caviae AHA0618 gene modulates cell length and influences swimming and swarming motility

Aeromonas caviae is motile via a polar flagellum in liquid culture, with a lateral flagella system used for swarming on solid surfaces. The polar flagellum also has a role in cellular adherence and biofilm formation. The two subunits of the polar flagellum, FlaA and FlaB, are posttranslationally modified by O-linked glycosylation with pseudaminic acid on 6–8 serine and threonine residues within the central region of these proteins. This modification is essential for the formation of the flagellum. Aeromonas caviae possesses the simplest set of genes required for bacterial glycosylation currently known, with the putative glycosyltransferase, Maf1, being described recently. Here, we investigated the role of the AHA0618 gene, which shares homology (37% at the amino acid level) with the central region of a putative deglycosylation enzyme (HP0518) from the human pathogen Helicobacter pylori, which also glycosylates its flagellin and is proposed to be part of a flagellin deglycosylation pathway. Phenotypic analysis of an AHA0618 A. caviae mutant revealed increased swimming and swarming motility compared to the wild-type strain but without any detectable effects on the glycosylation status of the polar flagellins when analyzed by western blot analysis or mass spectroscopy. Bioinformatic analysis of the protein AHA0618, demonstrated homology to a family of l,d-transpeptidases involved in cell wall biology and peptidoglycan cross-linking (YkuD-like). Scanning electron microscopy (SEM) and fluorescence microscopy analysis of the wild-type and AHA0618-mutant A. caviae strains revealed the mutant to be subtly but significantly shorter than wild-type cells; a phenomenon that could be recovered when either AHA0618 or H. pylori HP0518 were introduced. We can therefore conclude that AHA0618 does not affect A. caviae behavior by altering polar flagellin glycosylation levels but is likely to have a role in peptidoglycan processing at the bacterial cell wall, consequently altering cell length and hence influencing motility

Heterogeneous glycosylation and methylation of the Aeromonas caviae flagellin

Bacterial swimming is mediated by the rotation of a flagellar filament. Many bacteria are now known to be able to O-glycosylate their flagellins, the proteins that make up the flagellar filament. For bacteria that use nonulosonic acid sugars such as pseudaminic acid, this glycosylation process is essential for the formation of a functional flagellum. However, the specific role of glycosylation remains elusive. Aeromonas caviae is a model for this process as it has a genetically simple glycosylation system. Here, we investigated the localization of the glycans on the A. caviae flagellum filament. Using mass spectrometry it was revealed that pseudaminic acid O-glycosylation was heterogeneous with no serine or threonine sites that were constantly glycosylated. Site-directed mutagenesis of particular glycosylation sites in most cases resulted in strains that had reduced motility and produced less detectable flagellin on Western blots. For flagellin O-linked glycosylation, there is no known consensus sequence, although hydrophobic amino acids have been suggested to play a role. We, therefore, performed site-directed mutagenesis of isoleucine or leucine residues flanking the sites of glycosylation and demonstrated a reduction in motility and the amount of flagellin present in the cells, indicating a role for these hydrophobic amino acids in the flagellin glycosylation process