Evaluating student learning of experimental design using online module and experiential learning

Digital learning may be an advantageous accessory to large university classes as an accessible and multifaceted method of content delivery. The purpose of this study was to evaluate student learning using an online module given over a week and an experiential lab offered over three weeks. A short-term longitudinal comparison was performed with first and second year biology students using pre- and post-concept inventory short answer quizzes about fundamental experimental design concepts associated with an eLearning module in a first year lab and in a second year Scientific Methods lab course. Furthermore, experimental design knowledge retention rates were assessed on a short-term basis, as well as comparisons, based on demographics (gender, age, secondary school location, etc.), within a sample of 78% of second year students and 24% of first year students to provide association-based inferences on students’ understanding of experimental design. Results from the concept inventory quizzes show that experiential learning in second year students is significantly more effective than the online counterpart in the first year course (difference of 3.2 (t = 12.2, P \u3c 0.001) with 95% CI: (2.7, 3.8). Students in first year had difficulty in identifying controls and students in both years found the question on replications to be a challenge. Educators can use this information to plan experiential/digital content resources based on course outcomes, as well as to gain insight into the level of experimental design knowledge in first and second year biology students

Interactions between lemongrass and lavender essential oils in combination with ampicillin influencing antibacterial activity on Sporosarcina ureae and Serratia liquefaciens

The purpose of this study is to determine the effects of various combinations of essential oils (EOs) with antibiotics on bacterial growth. The molecular mechanisms behind the effects of individual phytochemicals in EOs and antibiotics is well understood, unlike the mechanisms behind the interactions between multiple phytochemicals and antibiotics in a mixture. Serratia liquefaciens and Sporosarcina ureae were exposed to various treatments of different combinations of Lavandula officinalis (lavender oil), Cymbopogon citratus (lemongrass oil) with ampicillin. For each treatment group, mean zones of inhibition (ZOI) were measured after exposure for 48 hours. Controls for both species did not yield any ZOI whereas all other treatments resulted in the inhibition of bacterial growth in both Serratia liquefaciens and Sporosarcina ureae. Statistical analyses showed that the combination of lemongrass oil and ampicillin was significantly more effective than all other treatments for Serratia liquefaciens. The lemongrass oil and ampicillin treatment was the only treatment that displayed additive effects. All treatments for Sporosarcina ureae, with the exception of the control and lavender oil treatments, showed a significantly higher mean ZOI when compared to control and lavender oil treatments. It was concluded that lemongrass oil was a better candidate to be included in antibacterial cocktails than lavender oil. However, further investigation is required to elucidate EOs that interact synergistically with ampicillin when acting on Serratia liquefaciens and Sporosarcina ureae. Additionally, further investigation into the molecular mechanisms behind the interactions of the components found in these EOs with ampicillin is required