Using virtual reality (VR) in educational settings is becoming increasingly popular. The feasibility of replacing an instrumentation-based organic chemistry lab with a VR experience has been evaluated. A VR laboratory experience was designed to teach students how to use an infrared spectrometer and elucidate an unknown structure from the resulting infrared spectrum. The resulting first-person VR experience is immersive and realistic, with a teaching assistant guiding the user along the steps required to complete the experiment, including feedback as needed. The VR experience was developed in WondaVR with selections made using gaze navigation. The resulting product was tested with a group of students, and the outcomes for short- and long-term recall were compared with a group of students that did the same experiment in a traditional lab. Results indicate that there are no significant differences in learning outcomes between the two groups, which indicates the possibility of using this tool to offer this organic chemistry lab experiment via distance education. Students that tried the VR experience reported a high degree of satisfaction with the product and no significant usability barriers. These VR experiences could be useful for students who are unable to be present in lab due to disabilities, attendance challenges such as pregnancy, or safety concerns.
Multimedia instruction has been shown to serve as an effective learning aid for chemistry students. In this study, the viability of student-generated video instruction for organic chemistry laboratory techniques and procedure was examined and its effectiveness compared to instruction provided by a teaching assistant (TA) was evaluated. After providing selected lab sections with either video or TA lab instruction, student participants were given an assessment to evaluate the effectiveness of each presentation. Videos were found to prepare students for lab more effectively, with an average of 17% more students answering questions correctly after watching the video than after receiving TA instruction. Additionally, according to direct observations, students were 37% less likely to require TA assistance during the lab when presented with video instruction. By providing students with short and concise student-generated video instructions, students in the observed courses were able to be more independent throughout the lab and perform better than students who had received TA instruction alone.
This study was designed to evaluate the effectiveness of student-generated videos as a supplement to teaching assistant (TA) instruction in an undergraduate organic chemistry laboratory. Three videos covering different aspects of lab instruction (experimental technique, use of instrumentation, and calculations) were produced using student-generated scripts. A laboratory classroom was outfitted with video cameras and sound recording equipment that allowed the research team to monitor all TA−student and student−student interactions. Six course sections led by three randomly assigned TAs were selected. Two sections from each TA were observed (control and treatment), each at the same time of day, 1 week apart. Students in the control group had their TA conduct the lab briefing and supervise the lab, but were given no access to the instructional videos. The treatment group had videos available to supplement the TA's lab briefing but was otherwise identical to the control group. Both groups were given a questionnaire that contained two comprehension questions per category to be completed during the lab before performing the experiment. Statistical analysis of the responses to this pre-experimental questionnaire showed that students who watched the videos had a better understanding of the methods than the students in sections that only received the TA lab briefing. Effect size calculations using Cohen's d indicate that the Instrumentation video had a large positive effect on the number of correct responses in the treatment groups, while small effects were found for the Technique and Calculation videos. Content analysis of the lab transcripts supports these findings. In addition to these effects, treatment groups invariably completed the lab in less time than the control groups. Results from a follow-up survey e-mailed to students the week after their lab session show that most students found the videos to be valuable when completing the lab, with the Technique video being generally ranked as most helpful.
Agricultural crops can be used either to remediate selenium-contaminated soils or to increase the daily selenium intake of consumers after soil supplementation using inorganic or organic selenium sources. In this study, four agricultural crops were examined for potential selenium enhancement. Soils containing tomato, strawberry, radish, and lettuce plants were supplemented with either an inorganic or an organic form of selenium. Two different soils, i.e., low Se and high Se containing, were also used. Statistically significant differences in appearance, fruit production, and fresh weights of the fruit produced were studied. Next, the amount of selenium retained in the edible fruits, nonedible plant, and soil for each was analyzed by acid digestion followed by hydride generation atomic absorption analysis. Finally, inhibition effects on the seeds of the agricultural plants were studied. The results show that supplementation with an inorganic form of selenium led to higher retention in the plants, with a maximum of 97.5% retained in the edible portion of lettuce plants.
Prostate-specific antigen (PSA) is a serine protease and one of the most abundant proteins secreted by the human prostate epithelium. PSA is used as a well-established marker of prostate cancer. The involvement of PSA in several early events leading to the development of malignant prostate tumors has made it a target for prevention and intervention. It is thought that PSA cleaves insulin-like growth factor binding protein-3 (IGFBP-3), providing increased local levels of IGF-1, leading to tumor growth. Separately, there are data that suggest an enzymatic regulatory role for dietary boron, which is a serine protease inhibitor. In this study we have addressed the use of boric acid as a PSA inhibitor in an animal study. We have previously reported that low concentrations (6 ug/mL) of boric acid can partially inhibit the proteolytic activity of purified PSA towards a synthetic fluorogenic substrate. Also, by Western blot we have followed the degradation of fibronectin by enzymatically active PSA and have found significant inhibition in the presence of boric acid. We proposed that dietary supplementation with boric acid would inhibit PSA and reduce the development and proliferation of prostate carcinomas in an animal model. We tested this hypothesis using nude mice implanted subcutaneously with LNCaP cells in Matrigel. Two groups (10 animals/group) were dosed with boric acid solutions (1.7, 9.0 mgB/kg/day) by gavage. Control group received only water. Tumor sizes were measured weekly for 8 weeks. Serum PSA and IGF-1 levels were determined at terminal sacrifice. The size of tumors was decreased in mice exposed to the low and high dose of boric acid by 38% and 25%, respectively. Serum PSA levels decreased by 88.6% and 86.4%, respectively, as compared to the control group. There were morphological differences between the tumors in control and boron-dosed animals, including a significantly lower incidence of mitotic figures in the boron-supplemented groups. Circulating IGF-1 levels were not different among groups, though expression of IGF-1 in the tumors was markedly reduced by boron treatment, which we have shown by immunohistochemistry. These data indicate that low-level dietary boron supplementation reduced tumor size and content of a tumor trophic factor, IGF-1.This promising model is being evaluated in further studies.
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