Karen Burke da Silva

Promoting Inquiry-Based Teaching in Laboratory Courses: Are We Meeting the Grade?

The authors reviewed the current literature on inquiry-based learning in laboratory courses and found that most exercises were guided inquiry. The majority of studies included assessment data showing learning gains. Few exercises were assessed in multiple courses or at multiple institutions. Therefore, whether results can be generalized is unclear.

Searching for a toxic key to unlock the mystery of anemonefish and anemone symbiosis.

Twenty-six species of anemonefish of the genera Amphiprion and monospecific Premnas, use only 10 species of anemones as hosts in the wild (Families: Actiniidae, Stichodactylidae and Thalassianthidae). Of these 10 anemone species some are used by multiple species of anemonefish while others have only a single anemonefish symbiont. Past studies have explored the different patterns of usage between anemonefish species and anemone species; however the evolution of this relationship remains unknown and has been little studied over the past decade. Here we reopen the case, comparing the toxicity of crude venoms obtained from anemones that host anemonefish as a way to investigate why some anemone species are used as a host more than others. Specifically, for each anemone species we investigated acute toxicity using Artemia francisca (LC50), haemolytic toxicity using ovine erythrocytes (EC50) and neurotoxicity using shore crabs (Ozius truncatus). We found that haemolytic and neurotoxic activity varied among host anemone species. Generally anemone species that displayed greater haemolytic activity also displayed high neurotoxic activity and tend to be more toxic on average as indicated by acute lethality analysis. An overall venom toxicity ranking for each anemone species was compared with the number of anemonefish species that are known to associate with each anemone species in the wild. Interestingly, anemones with intermediate toxicity had the highest number of anemonefish associates, whereas anemones with either very low or very high toxicity had the fewest anemonefish associates. These data demonstrate that variation in toxicity among host anemone species may be important in the establishment and maintenance of anemonefish anemone symbiosis.

The effect of sea anemone (H. magnifica) venom on two human breast cancer lines: death by apoptosis

Venom from the sea anemone, Heteractis magnifica, has multiple biological effects including, cytotoxic, cytolytic and hemolytic activities. In this study, cytotoxicity induced by H. magnifica venom was investigated using the crystal violet assay on human breast cancer T47D and MCF7 cell lines and normal human breast 184B5 cell line. Apoptosis was also assayed via Annexin V-flourescein isothiocyanate and propidium iodide (PI) staining followed by flow cytometric analysis. Cell cycle progression and mitochondria membrane potential were studied via flow cytometry following PI and JC-1 staining respectively. H. magnifica venom induced significant reductions in viable cell numbers and increases in apoptosis in T47D and MCF7 in dose-dependent manners. A significant apoptosis-related increase in the sub G1 peak of the cell cycle in both breast cancer cell lines was also observed. Moreover, treatment by venom cleaved caspase-8, caspase-9, and activated caspase-3. Overall, H. magnifica venom was highly cytotoxic to T47D and MCF7 human breast cancer cells, and the phenomenon could be the killing phenomenon via the death receptor-mediated and the mitochondria-mediated apoptotic pathways. Consequently, H. magnifica venom has potential for the development of a breast cancer therapeutic.

An analysis of the effectiveness of feedback to students on assessed work

This paper presents the views of students, from a range of schools and disciplines, on the effectiveness of current assessment feedback practices at Flinders University. We also report on a workshop on feedback with teachers. Overall, individual written comments were found to be the most useful form of feedback. However, there was significant variation with the level of satisfaction with feedback and the relative usefulness of different forms of feedback across the different schools and disciplines. This research suggests both the need to improve the effectiveness of such feedback and to tailor the forms of feedback offered to students according to the distinctive teaching and learning environments in different schools and disciplines. To that end, innovation and further research on feedback are justified, and some suggestions are offered.

Venom present in sea anemone (Heteractis magnifica) induces apoptosis in non-small-cell lung cancer A549 cells through activation of mitochondria-mediated pathway

Lung cancer is a major cause of cancer deaths throughout the world and the complexity of apoptosis resistance in lung cancer is apparent. Venom from Heteractis magnifica caused dose-dependent decreases in survival of the human non-small-cell lung cancer cell line, as determined by the MTT and Crystal Violet assays. The H. magnifica venom induced cell cycle arrest and induced apoptosis of A549 cells, as confirmed by annexin V/propidium iodide staining. The venom-induced apoptosis in A549 cells was characterized by cleavage of caspase-3 and a reduction in the mitochondrial membrane potential. Interestingly, crude extracts from H. magnifica had less effect on the survival of non-cancer cell lines. In the non-cancer cells, the mechanism via which cell death occurred was through necrosis not apoptosis. These findings are important for future work using H. magnifica venom for pharmaceutical development to treat human lung cancer.

Evolution: Improving the Understanding of Undergraduate Biology Students with an Active Pedagogical Approach

Students in a large introductory biology course at Flinders University, South Australia, were quizzed on misconceptions relating to evolution and their acceptance of evolutionary theory before and after completing the course. By providing students with a course featuring a multifaceted approach to learning about evolution, students improved their understanding and decreased their overall misconceptions. A variety of instructional methods and assessment tools were utilized in the course, and it employed an active and historically rich pedagogical approach. Although student learning and understanding of evolutionary theory improved throughout the course, it did not alter the beliefs of students who commented both before and after the course that religious theories provided adequate explanation for the diversity of life. Interestingly, students who maintained this belief scored more poorly on the final examination than students who considered evolution as the best explanation for the diversity of life.

Evolution-Centered Teaching of Biology

University teaching remains an area of concern, and perhaps the most difficult discipline for both teaching and learning is evolution. The concepts that underpin evolution, although complex, have been shown to be fairly straightforward, yet students arrive at and leave university with serious misconceptions, misunderstandings related to language, and often a reluctance to learn the subject because of cultural or societal pressures. Because of the unifying power of the theory, however, it is necessary not only for biology students to have a thorough understanding of evolution, but also for them to learn it in their first year so that this knowledge can then be taken into further years of study. Rather than teaching evolution at the end of a degree program, embedding it as a semester-long first-year course will ensure that a far larger number of students are made aware of misconceptions that they have brought with them from high school. Teaching through traditional passive lectures makes learning difficult conceptual material more difficult, and needs to be replaced with more interactive lectures coupled with inquiry-based practicals and small group-learning sessions to increase student engagement and interest in the subject. A new approach in pedagogy, curriculum design, and academic staff professional development is essential, especially at this time, when enrollments across science courses in many countries around the world are in decline.

Development, Evaluation and Use of a Student Experience Survey in Undergraduate Science Laboratories: The Advancing Science by Enhancing Learning in the Laboratory Student Laboratory Learning Experience Survey.

Student experience surveys have become increasingly popular to probe various aspects of processes and outcomes in higher education, such as measuring student perceptions of the learning environment and identifying aspects that could be improved. This paper reports on a particular survey for evaluating individual experiments that has been developed over some 15 years as part of a large national Australian study pertaining to the area of undergraduate laboratories—Advancing Science by Enhancing Learning in the Laboratory. This paper reports on the development of the survey instrument and the evaluation of the survey using student responses to experiments from different institutions in Australia, New Zealand and the USA. A total of 3153 student responses have been analysed using factor analysis. Three factors, motivation, assessment and resources, have been identified as contributing to improved student attitudes to laboratory activities. A central focus of the survey is to provide feedback to practitioners to iteratively improve experiments. Implications for practitioners and researchers are also discussed.

The Use of Pre-Lectures in a University Biology Course--Eliminating the Need for Prerequisites.

Abstract First year biology students at Flinders University with no prior biology background knowledge fail at almost twice the rate as those with a background. To remedy this discrepancy we enabled students to attend a weekly series of pre-lectures aimed at providing basic biological concepts, thereby removing the need for students to complete a prerequisite course. The overall failure rate of first year biology students was lowered and the gap between students with and without the background knowledge was significantly reduced. The overall effect of the implementation of pre-lectures was a more appropriate level of teaching for the first year students, neither too difficult for students without a prior biology background and no longer too easy (or repetitive) for students with high school level biology.

How Venom from the Magnificent Sea Anemone, Heteractis magnifica, Kills Breast and Lung Cancer Cells

The sea anemone Heteractis magnifica, also known as the “magnificent one”, is a friendly host to anemonefish. However, it has venom which acts as a chemical defence against predators that helps it to acquire prey in the marine environment. Heteractis magnifica produces venom with multiple biological activities. We have shown killing activity against human lung and breast cancer cells that was concentration-dependent (5–40 μg/ml). The mechanism of cancer cell killing by the venom was also uncovered. Apoptosis (programmed cell death) resistance is a hallmark of cancer. Heteractis magnifica venom induces apoptosis in human lung and breast cancer cell lines. Apoptosis occurs via two pathways and the investigation of these pathways has been discovered. Another hallmark of cancer is cell cycle deregulation, and H. magnifica venom was shown to modulate cell cycle progression in the cancer cell lines mentioned above. Thus the types and levels of breast and lung cancer cell killing by venom from the “Magnificent” sea anemone is explored as well as the mechanistic pathways underlying those effects.