Attitudes and Experiences of Preservice Teachers Utilizing Video Annotation Software: A Phenomenological Study

The purpose of this hermeneutic phenomenological study was to explore preservice teachers’ experiences with video observations at Central University. The theory guiding this study was Bandura’s self-efficacy theory as it provides insights into the internal and external factors that affect an individual’s perception of their capabilities. Self-efficacy is a critical component and goal of field experience observations. The central research question for this hermeneutic phenomenological study was: What are preservice teachers’ attitudes and experiences using video annotation software during field experience? The study was divided into two phases: individual interviews with preservice teachers, audio-visual elicitation interviews, a letter-writing activity, and qualitative data aggregation. Four themes were derived from the participants’ experiences: (a) streamlined reflection, (b) digital detachment, (c) the supervisor variable, and (d) program components’ effect on self-efficacy. Interpretations of the themes included four significant interpretations: (a) video annotation software improves reflection capabilities and personal agency, (b) video annotation software is a field supervision tool, not replacement, (c) convenient but not complete: video annotation software asynchronous communication is not enough, and (d) expectations and structure matter

Espresso coffees, caffeine and chlorogenic acid intake: potential health implications

HPLC analysis of 20 commercial espresso coffees revealed 6-fold differences in caffeine levels, a 17-fold range of caffeoylquinic acid contents, and 4-fold differences in the caffeoylquinic acid:caffeine ratio. These variations reflect differences in batch-to-batch bean composition, possible blending of arabica with robusta beans, as well as roasting and grinding procedures, but the predominant factor is likely to be the amount of beans used in the coffee-making/barista processes. The most caffeine in a single espresso was 322 mg and a further three contained >200 mg, exceeding the 200 mg day−1 upper limit recommended during pregnancy by the UK Food Standards Agency. This snap-shot of high-street expresso coffees suggests the published assumption that a cup of strong coffee contains 50 mg caffeine may be misleading. Consumers at risk of toxicity, including pregnant women, children and those with liver disease, may unknowingly ingest excessive caffeine from a single cup of espresso coffee. As many coffee houses prepare larger volume coffees, such as Latte and Cappuccino, by dilution of a single or double shot of expresso, further study on these products is warranted. New data are needed to provide informative labelling, with attention to bean variety, preparation, and barista methods

Using bacterial biomarkers to identify early indicators of cystic fibrosis pulmonary exacerbation onset

Acute periods of pulmonary exacerbation are the single most important cause of morbidity in cystic fibrosis patients, and may be associated with a loss of lung function. Intervening prior to the onset of a substantially increased inflammatory response may limit the associated damage to the airways. While a number of biomarker assays based on inflammatory markers have been developed, providing useful and important measures of disease during these periods, such factors are typically only elevated once the process of exacerbation has been initiated. Identifying biomarkers that can predict the onset of pulmonary exacerbation at an early stage would provide an opportunity to intervene before the establishment of a substantial immune response, with major implications for the advancement of cystic fibrosis care. The precise triggers of pulmonary exacerbation remain to be determined; however, the majority of models relate to the activity of microbes present in the patient's lower airways of cystic fibrosis. Advances in diagnostic microbiology now allow for the examination of these complex systems at a level likely to identify factors on which biomarker assays can be based. In this article, we discuss key considerations in the design and testing of assays that could predict pulmonary exacerbations

Spectral Theory of Sparse Non-Hermitian Random Matrices

Sparse non-Hermitian random matrices arise in the study of disordered physical systems with asymmetric local interactions, and have applications ranging from neural networks to ecosystem dynamics. The spectral characteristics of these matrices provide crucial information on system stability and susceptibility, however, their study is greatly complicated by the twin challenges of a lack of symmetry and a sparse interaction structure. In this review we provide a concise and systematic introduction to the main tools and results in this field. We show how the spectra of sparse non-Hermitian matrices can be computed via an analogy with infinite dimensional operators obeying certain recursion relations. With reference to three illustrative examples --- adjacency matrices of regular oriented graphs, adjacency matrices of oriented Erd\H{o}s-R\'{e}nyi graphs, and adjacency matrices of weighted oriented Erd\H{o}s-R\'{e}nyi graphs --- we demonstrate the use of these methods to obtain both analytic and numerical results for the spectrum, the spectral distribution, the location of outlier eigenvalues, and the statistical properties of eigenvectors.Comment: 60 pages, 10 figure

Hubble Space Telescope Survey of Interstellar ^12CO/^13CO in the Solar Neighborhood

We examine 20 diffuse and translucent Galactic sight lines and extract the column densities of the ^12CO and ^13CO isotopologues from their ultraviolet A--X absorption bands detected in archival Space Telescope Imaging Spectrograph data with lambda/Deltalambda geq 46,000. Five more targets with Goddard High-Resolution Spectrograph data are added to the sample that more than doubles the number of sight lines with published Hubble Space Telescope observations of ^13CO. Most sight lines have 12-to-13 isotopic ratios that are not significantly different from the local value of 70 for ^12C/^13C, which is based on mm-wave observations of rotational lines in emission from CO and H_2CO inside dense molecular clouds, as well as on results from optical measurements of CH^+. Five of the 25 sight lines are found to be fractionated toward lower 12-to-13 values, while three sight lines in the sample are fractionated toward higher ratios, signaling the predominance of either isotopic charge exchange or selective photodissociation, respectively. There are no obvious trends of the ^12CO-to-^13CO ratio with physical conditions such as gas temperature or density, yet ^12CO/^13CO does vary in a complicated manner with the column density of either CO isotopologue, owing to varying levels of competition between isotopic charge exchange and selective photodissociation in the fractionation of CO. Finally, rotational temperatures of H_2 show that all sight lines with detected amounts of ^13CO pass through gas that is on average colder by 20 K than the gas without ^13CO. This colder gas is also sampled by CN and C_2 molecules, the latter indicating gas kinetic temperatures of only 28 K, enough to facilitate an efficient charge exchange reaction that lowers the value of ^12CO/^13CO.Comment: 1-column emulateapj, 23 pages, 9 figure

The aerodynamic performance of a range of FIFA-approved footballs

Much discussion surrounds the flight of a football especially that perceived as irregular and is typically done so with little understanding of the aerodynamic effects or substantive evidence of the path taken. This work establishes that for a range of FIFA approved balls there is a significant variation in aerodynamic performance. This paper describes the methods used for mounting stationary and spinning footballs in a wind tunnel enabling accurate force data to be obtained, and the analysis techniques used. The approach has been to investigate a number of scenarios: Non-spinning Reynolds Sweep, Unsteady Loads, Orientation Sensitivity (Yaw Sweep) and Spinning Reynolds Sweep. The techniques are applied to a number of footballs with differing constructions and the results reported. To put the aerodynamic data into context the results are applied in a flight model to predict the potential differences in the behaviour of each ball in the air. The paper concludes that although the drag characteristics are different for the different balls tested the simulation suggests that this has only a limited effect on the flight of the ball. It is also shown that the unsteadiness of the aerodynamic loads is unlikely to be responsible for unpredictable behaviour. However, it is also shown that there are significant differences in the lateral aerodynamic forces for a range of FIFA approved match balls, and that these aerodynamic differences have a significant effect on the flight path for both spinning and for slowly rotating balls

The application of simulation to the understanding of football flight

This paper demonstrates the value of using a flight model in the analysis of the flight of a football, and explores the complexity of the model required to produce useful results. Two specific aspects of the simulation are addressed: the need to include a model of spin decay and the requirement to include a full aerodynamic drag profile as a function of Reynolds number rather than a single indicative value. Both are aspects of the ball performance that are experimentally intensive to obtain. The simulated flights show that the inclusion of spin degradation is important if flight validation is the objective, but that it may be unnecessary in a comparative study. The simple analytical model of spin degradation is shown to overestimate the reduction in lateral deviation when compared to experimentally acquired data. Therefore, the experimental method is preferred. The analysis of the shape of the drag profile (drag coefficient against Reynolds number) is explored, and it is shown from the simulated flights that post-critical coefficients of drag have the greatest effect on trajectories, and an average drag value is sufficient for most modelled scenarios

Mixed superposition rules and the Riccati hierarchy

Mixed superposition rules, i.e., functions describing the general solution of a system of first-order differential equations in terms of a generic family of particular solutions of first-order systems and some constants, are studied. The main achievement is a generalization of the celebrated Lie-Scheffers Theorem, characterizing systems admitting a mixed superposition rule. This somehow unexpected result says that such systems are exactly Lie systems, i.e., they admit a standard superposition rule. This provides a new and powerful tool for finding Lie systems, which is applied here to studying the Riccati hierarchy and to retrieving some known results in a more efficient and simpler way.Comment: 20 page