Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
J Chem Educ ; 100(8): 2873-2886, 2023 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-37576851

RESUMEN

This article examines student experiences in a workshop-based undergraduate research experience studying the activity and inhibition of salivary amylase that provides students with the chance to participate in authentic scientific research prior to the start of their undergraduate studies, following the structure of a course-based undergraduate research experience (CURE). Understanding student experiences at this point in their studies is important because research experiences at the beginning of university studies have been shown to increase retention in STEM. This study utilizes meaningful learning and situated cognition as theoretical frameworks and phenomenography as a methodological framework, applied to data from semi-structured interviews with six students. The student experiences were characterized as an outcome space detailing the degree of their meaningful learning with respect to their understanding of the research process, nature of science, and the poster creation and presentation process. The findings highlight that meaningful learning is achieved when research is connected to students' personal lives and/or future job interests. The research process and nature of science must also be made explicit to students by emphasizing the iterative nature of research and highlighting distinctions between science and non-science fields. All participating students displayed an understanding that anyone can partake in science anywhere. Implications for building on this work to develop an understanding of students' sense of belonging and self-identity are also discussed.

2.
J Chem Educ ; 99(1): 307-316, 2022 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-35979036

RESUMEN

This reflective overview describes the benefits of participation in authentic undergraduate research for students at a Historically Black College and University (HBCU). The department of chemistry and biochemistry at Hampton University has an undergraduate research environment that empowers and fosters a success-oriented research experience for our diverse students. By engaging undergraduate students in research early in their careers, we successfully motivate students to make informed decisions about pursuing STEM careers and entering graduate schools with high confidence. Our structured undergraduate research experiences are created within an inclusive environment that instills a sense of belonging and recognizes the talent all our students bring to STEM. We reflect on our experiences using faculty-student research collaborations within nurturing support systems that leverage African American culture while setting high expectations to improve scientific skills and retain our HBCU students in STEM.

3.
J Chem Educ ; 99(5): 2135-2142, 2022 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-35770202

RESUMEN

We report a new online suite of tools that enables inquiry-based active-learning activities to develop students' representational competence about atomic orbitals. Orbital Explorer is Web site hub for the visualization and interactive investigation of atomic orbital properties. Orbital Explorer contains two integrated tools, namely, Atomic Orbital Explorer, which enables one to visualize and interrogate individual atomic orbitals, and Orbital RDF Comparison, which enables one to make a more detailed quantitative comparison of orbital energies and properties of orbital radial distribution functions (RDFs). In addition, we present an original chemistry educational gamification design, BingOrbital, constructed in a format resembling Bingo (American version). The game aims to reinforce the recognition of atomic orbitals based on the RDF and 3D isosurface and has been applied as an engaging retrieval practice tool. A companion set of example activities that use the Orbital Explorer and BingOrbital game have been presented in another article.

4.
J Chem Educ ; 99(5): 2175-2181, 2022 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-35645409

RESUMEN

Atomic orbitals represent an essential construct used to develop chemical bonding models, upon which other more advanced chemistry topics are built. In this article, we share a series of active-learning activities and a gamified approach to develop students' representational competence about atomic orbitals and to engage students in learning the properties of atomic orbitals. These properties are essential for understanding an array of fundamental concepts such as penetration and shielding, relationships such as periodic trends, and models used to describe chemical bonding. The activities employ an inquiry-based approach to engage students in exploring the relationship between atomic orbitals' spatial properties and quantum numbers. The activities guide students to collect data to verify periodic trends and construct electronic configurations. The activities utilize Orbital Explorer Web site for visualization, comparison and analysis of atomic orbitals. The Orbital Explorer Web site is described in a related Technology Report. The activities and the game are suitable to be conducted in both in-person and remote-teaching settings.

5.
J Chem Educ ; 99(1): 402-408, 2022 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-35221372

RESUMEN

The COVID-19 pandemic redefined how chemistry laboratories were taught. It also introduced a racial health disparity for Black and Brown people. The General Chemistry I laboratory curriculum at a Historically Black College and University (HBCU) in Baltimore, MD, was redesigned to meet student needs during this challenging time. While surrounded by civil unrest and uncertainty, we wanted to reach our underrepresented students in a way that they felt seen and heard. "The Mystery of Mr. Johnson" series was designed to reinforce the role chemistry can serve in advancing equity in their community. This interconnected series of three experiments (Solutions, Titration, Spectroscopy) developed chemistry laboratory skills which were applied to diabetes, a COVID-19 comorbidity, and health disparity highly prevalent in Baltimore. "The Mystery of Mr. Johnson" series provided opportunities for students to gain exposure to the role of chemistry in addressing a health disparity that impacts their community. The culminating project was a public service announcement to communicate lifestyle changes and the prevalence of diabetes in the black community.

6.
J Chem Educ ; 98(2): 281-292, 2021 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-34024936

RESUMEN

As the conversation in higher education shifts from diversity to inclusion, the attrition rates of students in the STEM fields continues to be a point of discussion. Combined with the demand for expansion in the STEM workforce, various retention reforms have been proposed, implemented, and in some cases integrated into policy following evidence of success. Still, new findings, technological advances, and socio-cultural shifts inevitably necessitate an on-going investigation as to how students approach learning. Among other factors, students who enter college without effective study skills are at much greater risk of being unsuccessful in their coursework. In order to construct an equitable learning environment, a mechanism must be developed to provide underprepared students with access to resources or interventions designed to refine the skills they need to be successful in the course. Early, reliable assessments can provide predictions of individual student outcomes in order to guide the development and implementation of such targeted interventions. In the present study, a model is developed to predict students' odds of success based their study approaches, as measured by their responses to twelve survey items from an existing instrument used in the Chemistry Education Research literature designed to measure students' deep and surface learning approaches. The model's prediction specificity ranges from 66.5% to 86.9% by semester. Two distinct sets of lower-performing students are identified in the data: those who align predominantly with surface approaches to learning versus those who indicate using both deep and surface approaches to learning. This supports the idea of a tailored approach to interventions, rather than a one-size-fits-all solution. Results from this instrument were correlated to students' reported study methods and beliefs.

7.
J Chem Educ ; 98(10): 3090-3099, 2021 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-35250048

RESUMEN

Nanoscience and technology research offer exciting avenues to modernize undergraduate-level General Chemistry curricula. In particular, spherical nucleic acid (SNA) nanoconjugates, which behave as "programmable atom equivalents" (PAEs) in the context of colloidal crystals, are one system that one can use to reinforce foundational concepts in chemistry including matter and atoms, the Periodic Table, Lewis dot structures and the octet rule, valency and valence-shell electron-pair repulsion (VSEPR) theory, and Pauling's rules, ultimately leading to enriching discussions centered on materials chemistry and biochemistry with key implications in medicine, optics, catalysis, and other areas. These lessons connect historical and modern concepts in chemistry, relate course content to current professional and popular science topics, inspire critical and creative thinking, and spur some students to continue their science, technology, engineering, and mathematics (STEM) education and attain careers in STEM fields. Ultimately, and perhaps most importantly, these lessons may expand the pool of young students interested in chemistry by making connections to a broader group of contemporary concepts and technologies that impact their lives and enhance their view of the field. Herein, a way of teaching aspects of General Chemistry in the context of modern nanoscience concepts is introduced to instructors and curricula developers at research institutions, primarily undergraduate institutions, and community colleges worldwide.

8.
J Chem Educ ; 97(8): 2078-2090, 2020 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-32952212

RESUMEN

The Teaching Internship is a credit-bearing program comprised of undergraduate near peer instructors (Teaching Interns, or TIs) that offers supplemental assistance for students in the General Chemistry courses. With fellow undergraduates serving as a role model and student-faculty liaison, the benefits of near peer instruction have been well-documented. Because TIs develop a dual role of student and instructor over time, they afford a unique opportunity to explore the middle area of the expert/novice spectrum. Identifying the most influential components of the TI role may allow practitioners to implement these components in other ways for different groups of students. The present work provides a description of the TI model and uses a mixed-methods approach to analyze how the peer leadership role impacted the TIs' attitudes about learning chemistry. Quantitative results show that TIs do hold predominantly expert-like learning attitudes compared to the General Chemistry population from which they are selected; however, evidence of novice thinking is still observed in some areas. This survey data was then used to inform a qualitative approach. Further analysis indicated that TIs' responses on survey items were context-dependent, and that peer leadership experiences were associated with expert learning attitudes and appear to be influential in the development of these attitudes. These findings suggest that these factors should be taken into account when drawing general conclusions from survey results.

9.
Biochem Mol Biol Educ ; 47(3): 333-340, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30748072

RESUMEN

Allelopathy plays crucial roles in invasive plant viability and agricultural production systems. However, there is no well-established hands-on learning activity to teach the concept of allelopathy. Nor is there an activity which allows students to gain knowledge about glucosinolates and their corresponding enzyme, myrosinase, which are present in almost all Brassica crops. Lettuce germination was counted by the students from three different treatments including water treated with Parafilm sealing, horseradish treated with Parafilm sealing, and horseradish treated without Parafilm sealing. Additionally, lettuce root length was measured by students using ImageJ software from each treatment using pictures captured by students' smartphones. Students took an identical quiz as a pre-laboratory and a post-laboratory assignment. Their average scores on the pre-laboratory and post-laboratory quizzes were 3.14 and 6.56 out of 10, respectively, indicating the lab activity significantly improved students' understanding of allelopathy and glucosinolate-myrosinase system. In addition, students (n = 76) completed a survey post-laboratory to assess their self-efficacy. This simple and cost-effective laboratory activity improved students' knowledge and skill development as it made learning more inviting, meaningful, and fun. © 2019 International Union of Biochemistry and Molecular Biology, 47(3):333-340, 2019.


Asunto(s)
Alelopatía , Armoracia/química , Lactuca/química , Aprendizaje , Extractos Vegetales/química , Semillas/química , Glucosinolatos/química , Glucosinolatos/metabolismo , Glicósido Hidrolasas/química , Glicósido Hidrolasas/metabolismo , Humanos , Laboratorios , Raíces de Plantas/química , Estudiantes
10.
J Chem Educ ; 96(11): 2441-2449, 2019 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-33911314

RESUMEN

The "International Research Experience for Students (IRES)" at Doane University (DU) located in Crete, Nebraska, exposed undergraduate science, technology, engineering, and mathematics (STEM) students to international research at the Karlsruhe Institute of Technology (KIT) in Germany. The international collaboration team included three undergraduate researchers per year from DU, one faculty member and one postdoctoral fellow from DU, two faculty mentors at KIT, and several graduate, post-doctoral, and technical staff at KIT. Prior to departure to Germany, the students received extensive research training, as well as culture and language preparation from the mentors at DU. While in Germany, the students received an in-depth orientation to Karlsruhe, Germany, Europe, the research setting at KIT, and the international collaborators. The eight week summer projects over three years involved nanolithography, nano- to microsized array fabrication, organic synthesis using click chemistry, and surface modifications for sensing and other biomedical research applications. When the students returned from Germany, they continued to conduct research at DU and train other undergraduate students using the expertise acquired from KIT. The DU research students, including the IRES scholars, learned oral and written communication skills. They presented their KIT and DU research results at weekly seminars and at local and national meetings. An external assessment firm evaluated the program, the students, and mentors on a yearly basis before and after the summer research. This enabled all participants to continuously improve the learning objectives and the program execution including three program adjustments implemented in year 2 or 3. The survey data shows that the IRES program provided an enriching experience for the students in research and international culture and established a successful base of collaboration for mentors.

11.
J Chem Educ ; 95(5): 691-699, 2018 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-30197451

RESUMEN

We investigated whether use of an adaptive-responsive online homework system (OHS) that tailors homework to students' prior knowledge and periodically reassesses students to promote learning through practice retrieval has inherent advantages over traditional-responsive online homework. A quasi-experimental cohort control post-test-only design with nonequivalent groups and propensity scores with nearest neighbor matching (n = 6,114 pairs) was used. The adaptive system was found to increase the odds of a higher final letter grade for average, below average, and failing students. However, despite the learning advantages, students self-reported less favorable attitudes toward adaptive-responsive (3.15 of 5) relative to traditional-responsive OHS (3.31). Specific to the adaptive OHS, the following were found: (i) student attitudes were moderately and positively correlated (r = 0.36, p < 0.01) to final letter grade, (ii) most students (95%) reported engaging in remediation of incorrect responses, (iii) a majority of students (69%) reported changes in study habits, and (iv) students recognized the benefit of using adaptive OHS by ranking its assignments and explanations or review materials as two of the top three most useful course aspects contributing to perceived learning. Instructors can use our findings to inform their choice of online homework system for formative assessment of chemistry learning by weighing the benefits, disadvantages, and learning pedagogies of traditional-responsive versus adaptive-responsive systems.

12.
J Chem Educ ; 94(9): 1209-1216, 2017 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-28919643

RESUMEN

As it connects to a large set of important fundamental ideas in chemistry and analytical techniques discussed in high school chemistry curricula, we review the exploding flask demonstration. In this demonstration, methanol vapor is catalytically oxidized by a Pt wire catalyst in an open container. The exothermicity of reactions occurring at the catalytic surface heats the metal to the extent that it glows. When restricting reactant and product gas flow, conditions may favor repetitive occurrence of a small explosion. We show how mass spectrometry and infrared spectroscopy allow for unravelling the chemical background of this demonstration and discuss various ideas on how to use it in a classroom setting to engage students' critical thinking about chemical research. Along the way, we show that two commonly published ideas about the chemical background of this demonstration are incorrect, and we suggest simple tests that may be performed in a high school setting either as an addition to the demonstration or as a student research project.

13.
J Chem Educ ; 94(9): 1285-1287, 2017 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-28919644

RESUMEN

The "exploding" flask demonstration presents a well-known illustration of heterogeneous catalyzed methanol oxidation. We find that for the same vapor pressure, the demonstration also works for all primary and secondary alcohols up to butanol but not for a tertiary alcohol. Also, we show that the demonstration works for a large range of transition metal catalysts. Hence, this demonstration, which is often applied for the repetitive explosions when methanol is used, may also be used to argue the requirement of initial dehydrogenation of the alcohol to an aldehyde in the catalytic reaction mechanism to support the general insensitivity to reactant molecules in heterogeneous catalysis in contrast to biological catalysis and to provide proof for activity trends as often depicted by volcano plots.

14.
J Chem Educ ; 94(7): 941-945, 2017 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-34483361

RESUMEN

Proteins are involved in nearly every biological process, which makes them of interest to a range of scientists. Previous work has shown that hand-held cameras can be used to determine the concentration of colored analytes in solution, and this paper extends the approach to reactions involving a color change in order to quantify protein concentration (e.g., green to blue). Herein, we describe the successful use of smartphone colorimetry to quantify protein concentration using two common colorimetric biochemical methods, the Bradford and biuret assays. The ease of the experimental setup makes these lab experiments accessible to a wide range of students and can be used as both high school and college level laboratory experiments.

15.
J Chem Educ ; 91(8): 1220-1223, 2014 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-25132687

RESUMEN

An efficient laboratory experiment has been developed for undergraduate students to conduct hydrogen-deuterium (H-D) exchange of resorcinol by electrophilic aromatic substitution using D2O and a catalytic amount of H2SO4. The resulting labeled product is characterized by 1H NMR. Students also visualize a significant kinetic isotope effect (kH/kD ≈ 3 to 4) by adding iodine tincture to solutions of unlabeled resorcinol and the H-D exchange product. This method is highly adaptable to fit a target audience and has been successfully implemented in a pedagogical capacity with second-year introductory organic chemistry students as part of their laboratory curriculum. It was also adapted for students at the advanced high school level.

16.
J Chem Educ ; 90(9): 1200-1202, 2013 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-24092948

RESUMEN

A laboratory discussion worksheet and its answer key provide instructors and students a discussion model to further the students' understanding of chemical kinetics. This discussion worksheet includes a section for students to augment their previous knowledge about chemical kinetics measurements, an initial check on students' understanding of basic concepts, a group participation model where students work on solving complex-conceptual problems, and a conclusion to help students connect this discussion to their laboratory or lecture class. Additionally, the worksheet has a detailed solution to a more advanced problem to help students understand how the concepts they have put together relate to problems they will encounter during later formal assessments.

17.
J Chem Educ ; 90(7): 922-925, 2013 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-23929983

RESUMEN

Dotarem and Magnevist, two clinically available magnetic resonance imaging (MRI) contrast agents, were assessed in a high school science classroom with respect to which is the better contrast agent. Magnevist, the more efficacious contrast agent, has negative side effects because its gadolinium center can escape from its ligand. However, Dotarem, though a less efficacious contrast agent, is a safer drug choice. After the experiment, students are confronted with the FDA warning on Magnevist, which enabled a discussion of drug efficacy versus safety. We describe a laboratory experiment in which NMR spin lattice relaxation rate measurements are used to quantify the relaxivities of the active ingredients of Dotarem and Magnevist. The spin lattice relaxation rate gives the average amount of time it takes the excited nucleus to relax back to the original state. Students learn by constructing molar relaxivity curves based on inversion recovery data sets that Magnevist is more relaxive than Dotarem. This experiment is suitable for any analytical chemistry laboratory with access to NMR.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...