98 research outputs found
Differential Usage of Learning Management Systems in Chemistry Courses in the Time after COVID-19
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
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
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
A seminar on the current status of the CF2-Groups modifications to the CF Convention
Leveraging ChatGPT for Enhancing Critical Thinking Skills
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
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
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
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
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.
The blue part represents the portion of dates with these wind conditions and a beaching event.</p
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