98 research outputs found

    Differential Usage of Learning Management Systems in Chemistry Courses in the Time after COVID-19

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    Learning management systems play a crucial role in addressing pedagogical challenges imposed by the COVID-19 pandemic. The solutions provided by the learning management systems (LMS) facilitated online instructions and helped form a community of learning and support. With the rapid increased usage during the pandemic and the return to face-to-face post-pandemic, an in-depth analysis on lasting changes in students’ engagement and the instructors’ use of the systems during and after the pandemic is needed. This study aims at providing the analysis results on the differential usage of the learning management systems in a chronological time frame and on a course-level-specific aspect. Analysis conducted on the LMS usage data of chemistry courses between Fall 2019 and Fall 2021 suggests unique patterns, depending on the course levels. The extent of students’ interaction with peers and course materials varied for different course levels. The degree of usage of learning management systems by instructors also depended on the course levels. Instructors in lower-level courses (1000 and 2000 level courses) continued to use learning management systems extensively after the pandemic, while instructors in upper-level courses (3000 and 4000 level courses) rebounded to their pre-pandemic level of usage after resuming face-to-face instructions

    Differential Usage of Learning Management Systems in Chemistry Courses in the Time after COVID-19

    No full text
    Learning management systems play a crucial role in addressing pedagogical challenges imposed by the COVID-19 pandemic. The solutions provided by the learning management systems (LMS) facilitated online instructions and helped form a community of learning and support. With the rapid increased usage during the pandemic and the return to face-to-face post-pandemic, an in-depth analysis on lasting changes in students’ engagement and the instructors’ use of the systems during and after the pandemic is needed. This study aims at providing the analysis results on the differential usage of the learning management systems in a chronological time frame and on a course-level-specific aspect. Analysis conducted on the LMS usage data of chemistry courses between Fall 2019 and Fall 2021 suggests unique patterns, depending on the course levels. The extent of students’ interaction with peers and course materials varied for different course levels. The degree of usage of learning management systems by instructors also depended on the course levels. Instructors in lower-level courses (1000 and 2000 level courses) continued to use learning management systems extensively after the pandemic, while instructors in upper-level courses (3000 and 4000 level courses) rebounded to their pre-pandemic level of usage after resuming face-to-face instructions

    Leveraging ChatGPT for Enhancing Critical Thinking Skills

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    This article presents a study conducted at Georgia Gwinnett College (GGC) to explore the use of ChatGPT, a large language model, for fostering critical thinking skills in higher education. The study implemented a ChatGPT-based activity in introductory chemistry courses, where students engaged with ChatGPT in three stages: account setup and orientation, essay creation, and output revision and validation. The results showed significant improvements in students’ confidence to ask insightful questions, analyze information, and comprehend complex concepts. Students reported that ChatGPT provided diverse perspectives and challenged their current ways of thinking. They also expressed an increased utilization of ChatGPT to enhance critical thinking skills and a willingness to recommend it to others. However, challenges included low-quality student comments and difficulties in validating information sources. The study highlights the importance of comprehensive training for educators and access to reliable resources. Future research should focus on training educators in integrating ChatGPT effectively and ensuring student awareness of privacy and security considerations. In conclusion, this study provides valuable insights for leveraging AI technologies like ChatGPT to foster critical thinking skills in higher education

    smn_cf2_esip_201807.pdf

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    A seminar on the current status of the CF2-Groups modifications to the CF Convention

    Leveraging ChatGPT for Enhancing Critical Thinking Skills

    No full text
    This article presents a study conducted at Georgia Gwinnett College (GGC) to explore the use of ChatGPT, a large language model, for fostering critical thinking skills in higher education. The study implemented a ChatGPT-based activity in introductory chemistry courses, where students engaged with ChatGPT in three stages: account setup and orientation, essay creation, and output revision and validation. The results showed significant improvements in students’ confidence to ask insightful questions, analyze information, and comprehend complex concepts. Students reported that ChatGPT provided diverse perspectives and challenged their current ways of thinking. They also expressed an increased utilization of ChatGPT to enhance critical thinking skills and a willingness to recommend it to others. However, challenges included low-quality student comments and difficulties in validating information sources. The study highlights the importance of comprehensive training for educators and access to reliable resources. Future research should focus on training educators in integrating ChatGPT effectively and ensuring student awareness of privacy and security considerations. In conclusion, this study provides valuable insights for leveraging AI technologies like ChatGPT to foster critical thinking skills in higher education

    Primostrato Solid-State NMR Enhanced by Dynamic Nuclear Polarization: Pentacoordinated Al<sup>3+</sup> Ions Are Only Located at the Surface of Hydrated γ‑Alumina

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    Aluminas (Al2O3) are ubiquitous functional materials. In particular, the γ-alumina form is extensively used in research and industry as a catalyst and catalyst support. Nevertheless, a full structural description, which would aid in comprehension of its properties, is lacking and under large debate. Solid-state NMR has been used previously to study γ-alumina but is limited for certain applications, such as surface studies, due to intrinsic low sensitivity. Here, we detail the implementation of low temperature (∼100 K) magic angle spinning combined with dynamic nuclear polarization (MAS-DNP) to significantly enhance the sensitivity of solid-state NMR experiments and gain structural insights into this important material. Notably, we analyze hydrophilic and hydrophobic sample preparation protocols and their implications on the sample and resulting NMR parameters. We show that the choice of preparation does not perturb the spectrum, but it does have a large effect on NMR coherence lifetimes, as does the corresponding required (hyper)­polarizing agent. We use this preliminary study to optimize the absolute sensitivity of the following experiments. We then show that there are no detectable hydroxyl groups in the bulk of the material and that DNP-enhanced 1H → 27Al cross-polarization experiments are selective to only the first surface layer, enabling a very specific study. This primostrato NMR is integrated with multiple-quantum magic angle spinning (MQMAS) and it is demonstrated, interestingly, that pentacoordinated Al3+ ions are only observed in this first surface layer. To highlight that there is no evidence of subsurface pentacoordinated Al3+, a new bulk-filtered experiment is described that can eliminate surface signals

    Detection of the Surface of Crystalline Y<sub>2</sub>O<sub>3</sub> Using Direct <sup>89</sup>Y Dynamic Nuclear Polarization

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    Nuclei with low gyromagnetic ratio (γ) present a serious sensitivity challenge for nulear magnetic resonance (NMR) spectroscopy. Recently, dynamic nuclear polarization (DNP) has shown great promise in overcoming this hurdle by indirect hyperpolarization (via 1H) of these low-γ nuclei. Here we show that at a magnetic field of 9.4 T and cryogenic temperature of about 110 K direct DNP of 89Y in a frozen solution of Y­(NO3)3 can offer signal enhancements greater than 80 times using exogeneous trityl OX063 monoradical by satisfying the cross effect magic angle spinning (MAS) DNP mechanism. The large signal enhancement achieved permits 89Y NMR spectra of Y2O3 and Gd2O3-added Y2O3 materials to be obtained quickly (∼30 min), revealing a range of surface yttrium hydroxyl groups in addition to the two octahedral yttrium signals of the core. The results open up promises for the observation of low gyromagnetic ratio nuclei and the detection of corresponding surface and (sub-)­surface sites

    New Insights into the Activation of Escherichia coli Tyrosine Kinase Revealed by Molecular Dynamics Simulation and Biochemical Analysis

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    Escherichia coli tyrosine kinase (Etk) regulates the export of pathogenic capsular polysaccharide (CPS) by intermolecularly autophosphorylating its C-terminal tyrosine cluster. The kinase Etk, however, needs to be first activated by the intramolecular phosphorylation of a tyrosine residue, Y574, next to the active site. The recently determined structure of Etk shows that dephosphorylated Y574 blocks the active site and prevents substrate access. After phosphorylation, the negatively charged P-Y574 side chain was previously postulated to flip out to associate with a positively charged R614, unblocking the active site. This proposed activation is unique among protein kinases; however, there is no direct structural evidence in support of this hypothesis. In this paper, we carried out molecular dynamics simulation, mutagenesis, and biochemical analysis to study the activation mechanism of Etk. Our simulation results are in excellent agreement with the proposed molecular switch involving P-Y574 and R614 in the activation of Etk. Further, we show that a previously unidentified residue, R572, modulates the rotation of the P-Y574 side chain through electrostatic interaction, slowing down the opening of the active site. Our enzymatic assays demonstrate that the R572A mutant of Etk possesses significantly increased kinase activity, providing direct experimental support for the unique activation mechanism of Etk. In addition, the simulation of the Etk Y574F mutant predicted short periods of unblocked active site by Y574F, in good agreement with the low kinase activity of this mutant. The C-terminal substrate peptide and the nucleotide cofactor were also docked into the active site, and their implications are discussed

    New Insights into the Activation of Escherichia coli Tyrosine Kinase Revealed by Molecular Dynamics Simulation and Biochemical Analysis

    No full text
    Escherichia coli tyrosine kinase (Etk) regulates the export of pathogenic capsular polysaccharide (CPS) by intermolecularly autophosphorylating its C-terminal tyrosine cluster. The kinase Etk, however, needs to be first activated by the intramolecular phosphorylation of a tyrosine residue, Y574, next to the active site. The recently determined structure of Etk shows that dephosphorylated Y574 blocks the active site and prevents substrate access. After phosphorylation, the negatively charged P-Y574 side chain was previously postulated to flip out to associate with a positively charged R614, unblocking the active site. This proposed activation is unique among protein kinases; however, there is no direct structural evidence in support of this hypothesis. In this paper, we carried out molecular dynamics simulation, mutagenesis, and biochemical analysis to study the activation mechanism of Etk. Our simulation results are in excellent agreement with the proposed molecular switch involving P-Y574 and R614 in the activation of Etk. Further, we show that a previously unidentified residue, R572, modulates the rotation of the P-Y574 side chain through electrostatic interaction, slowing down the opening of the active site. Our enzymatic assays demonstrate that the R572A mutant of Etk possesses significantly increased kinase activity, providing direct experimental support for the unique activation mechanism of Etk. In addition, the simulation of the Etk Y574F mutant predicted short periods of unblocked active site by Y574F, in good agreement with the low kinase activity of this mutant. The C-terminal substrate peptide and the nucleotide cofactor were also docked into the active site, and their implications are discussed

    For each season and each site, a rose plot of wind conditions is shown.

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    The blue part represents the portion of dates with these wind conditions and a beaching event.</p
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