Understanding Teacher Reflection as a Significant Tool for Bringing Reform-Based Teaching to College Mathematics

This paper describes a senior mathematics professor’s effort to change his teaching practice in a mathematical analysis course for secondary pre-service teachers in alignment with the current reform movement. Data include semester-long observations and interviews with the professor and his students. The data were analyzed by the use of reflection as the most significant tool for examining his experience of bringing about change. The reflection was used as a bridge from theory to practice by serving as a significant point for the professor to experience the process of professional development in a real sense. Discussions include the role of teacher reflection, teacher beliefs about good teaching and their manifestation in practice, the role of students in a reform-based classroom and the professor\u27s effort for changing pedagogy of the mathematics course and his search for continuing the effort. The researcher includes her own reflection of the processes of understanding the change process. Her views on inconsistency between the professors beliefs and his practice, the role of reflection as a hallmark of professionalism, and the importance of environment and support for the change to be sustainable are addressed

On the relationship between the vortex formation process and cylinder wake vortex patterns

The idea of vortex formation time, originally developed for vortex ring formation, is extended to bluff-body flows. Effects related to characteristic vortex formation time are shown for both the cylinder starting from rest and the cylinder undergoing forced oscillations in a steady flow. By looking at how wake vortices are formed when the cylinder is accelerated from rest, it is found that similarities exist between the formation process for wakes and for vortex rings. This formation process is then observed for forced oscillating cylinders, where the characteristic formation time interacts with the oscillation period. Frequently observed bluff-body phenomena will be recast in light of the vortex formation process

Word Embedding based Correlation Model for Question/Answer Matching

With the development of community based question answering (Q&A) services, a large scale of Q&A archives have been accumulated and are an important information and knowledge resource on the web. Question and answer matching has been attached much importance to for its ability to reuse knowledge stored in these systems: it can be useful in enhancing user experience with recurrent questions. In this paper, we try to improve the matching accuracy by overcoming the lexical gap between question and answer pairs. A Word Embedding based Correlation (WEC) model is proposed by integrating advantages of both the translation model and word embedding, given a random pair of words, WEC can score their co-occurrence probability in Q&A pairs and it can also leverage the continuity and smoothness of continuous space word representation to deal with new pairs of words that are rare in the training parallel text. An experimental study on Yahoo! Answers dataset and Baidu Zhidao dataset shows this new method's promising potential.Comment: 8 pages, 2 figure

Fluctuations Do Matter: Large Noise-Enhanced Halos in Charged-Particle Beams

The formation of beam halos has customarily been described in terms of a particle-core model in which the space-charge field of the oscillating core drives particles to large amplitudes. This model involves parametric resonance and predicts a hard upper bound to the orbital amplitude of the halo particles. We show that the presence of colored noise due to space-charge fluctuations and/or machine imperfections can eject particles to much larger amplitudes than would be inferred from parametric resonance alone.Comment: 13 pages total, including 5 figure

Black Hole Feedback On The First Galaxies

We study how the first galaxies were assembled under feedback from the accretion onto a central black hole (BH) that is left behind by the first generation of metal-free stars through self-consistent, cosmological simulations. X-ray radiation from the accretion of gas onto BH remnants of Population III (Pop III) stars, or from high-mass X-ray binaries (HMXBs), again involving Pop III stars, influences the mode of second generation star formation. We track the evolution of the black hole accretion rate and the associated X-ray feedback starting with the death of the Pop III progenitor star inside a minihalo and following the subsequent evolution of the black hole as the minihalo grows to become an atomically cooling galaxy. We find that X-ray photoionization heating from a stellar-mass BH is able to quench further star formation in the host halo at all times before the halo enters the atomic cooling phase. X-ray radiation from a HMXB, assuming a luminosity close to the Eddington value, exerts an even stronger, and more diverse, feedback on star formation. It photoheats the gas inside the host halo, but also promotes the formation of molecular hydrogen and cooling of gas in the intergalactic medium and in nearby minihalos, leading to a net increase in the number of stars formed at early times. Our simulations further show that the radiative feedback from the first BHs may strongly suppress early BH growth, thus constraining models for the formation of supermassive BHs.Astronom

Leveraging Drug Repurposing: A Strategic Approach to Combat Bacterial Infections.

Aerospace physiology Leveraging Drug Repurposing: A Strategic Approach to Combat Bacterial Infections. Author Information: Wesley A. Flewelling, Anderson Y. Jeon and Giovanni Benjamin Faculty mentor: Dr. Alba Chavez The emergence of antibiotic resistant bacterial strains poses a critical threat to global public health, necessitating innovative strategies to address this challenge. Drug repurposing, the process of identifying new therapeutic uses for existing drugs, has emerged as a promising approach to Accelerate the development of effective treatments for bacterial infections. This research aims to highlight the importance of drug repurposing in the context of bacterial infections in an effort to emphasize the various advantages it offers over traditional drug discovery methods. We have selected 6 drugs that are not infrequently used to treat infections (including gentamycin sulfate, simvastatin, caspofungin, finasteride, ketorolac and clarithromycin) and tested their efficacy as antibacterial agents using four bacterial strains (Escherichia, Serratia, Micrococcus and Bacillus) as target model systems. We performed a comprehensive high throughput screening using a 96 well microplate approach and determined the Minimum Inhibitory Concentration (MIC) of bacterial growth. Our results indicate that Finasteride and Ketorolac are effective against the gram-negative bacteria Escherichia and Serratia, whereas Caspofungin and Clarithromycin are the most effective against the gram-positive Micrococcus and Bacillus. These results shed light into future perspectives of antimicrobial agents and possible treatments for fastidious infections. Embracing drug repurposing as a complementary strategy to traditional drug discovery efforts holds tremendous potential in the fight against bacterial infections