Fruit fly attractants and pheromones
(With Prof Phil Taylor, Department of Biological Sciences and A/Prof Joanne Jamie, Department of Chemistry and Biomolecular Sciences)
Bactrocera fruit flies – a genus of more than 500 species – include some of the world’s most devastating insect pests of horticulture. Airborne volatile organic compounds are used by these insects to communicate with each other and to find food and egg-laying sites. These compounds, or their analogues, have potential as tools for control. Attractants are used to monitor and control fruit fly populations.
Projects within this field may focus on one or more categories of compounds, but in all cases would involve a combination of collection and identification of compounds, analysis of dispersal and transformation in the atmosphere, and synthesis of novel and reference compounds.
Structure and composition of secondary organic aerosols
Organic aerosol accounts for a very large fraction of air particulate matter. It affects the atmosphere and climate through interaction with reactive trace gases, water vapour, clouds, precipitation, and radiation. It also influences the biosphere and human health through the spread of reproductive materials and micro-organisms, has impacts on respiratory and cardiovascular functions and is a factor in allergic and infectious disease spread. While advances have occurred in the science of organic aerosols, much remains to be understood concerning their composition, sources and transformation. The broad aim of this project is to improve our understanding of Secondary Organic Aerosol (SOA) composition in major Australian airsheds. In particular, we are concerned with the impact that both plant and motor vehicle emissions of volatile organic compounds (VOCs) have on SOA formation and composition and hence on air quality. This project will address the following scientific questions:
- Under photolytic conditions associated with aerosol formation, what are the reaction pathways of VOCs of significance in Australian urban and semi-urban airsheds?
- What is the molecular composition of Secondary Organic Aerosols?
- What similarities and differences are there between aerosol formation under homogeneous (unseeded) and heterogeneous (seeded) conditions?
Trace gases and volatile organic compounds
Identifying and quantifying the sources of volatile organic compounds (VOC’s) is important as these compounds are involved in complex chemical and physical transformations that result in effects such as smog formation, changes in the oxidative capacity of the atmosphere and aerosol formation.
Large volumes of VOC’s are emitted from plants (biogenic VOC’s) and from human activities (anthropogenic VOC’s), such as fossil fuel and biomass combustion, evaporation of solvents and fuels and production processes. Much effort has been put into reducing emissions of anthropogenic VOC’s, yet if the quantity of biogenic VOC’s is significant, then this effort may be misplaced. VOC’s and other trace species (such as NO, NO2 and CO) are contributors to poor indoor air quality. Increasing urbanisation results in an increase in the occupation of well-sealed buildings using recirculated air for climate control, which may lead to a decrease in indoor air quality. This is a growing concern throughout the world. Identification of sources of VOC’s and other trace species is a central issue in environmental management.
We have a range of projects concerned with identifying and quantifying VOC’s and their sources. The techniques incorporate Solid Phase Microextraction with GC and GC/MS analysis, cavity ring-down spectroscopy and Fourier Transform Infrared spectroscopy.
Emissions of greenhouse gases from livestock cows
Ruminants (cows, sheep) emit significant amounts of methane, a potent greenhouse gas. We are developing new ways of measuring methane emissions through Cavity-Ringdown Spectroscopy (CRDS), a laser-based technology that will allow monitoring of herds in remote locations. This innovative optical sensing technique will allow key molecular species (notably CH4, also CO2 & H2O) in ruminants' breath to be monitored simultaneously, sensitively and accurately.
The fibre-coupled CRDS approach has a short cycle time for high sampling rates, with distinct advantages relative to other forms of optical spectroscopy such as open-path laser or non-dispersive infrared absorption techniques.
Emissions of organic compounds in natural product chemistry
Vegetation emits significant quantities of Volatile Organic Compounds. These emissions may be correlated with internal chemistry of the plants, and give clues on such things as the presence of useful compounds, stage of plant development and the maturation state of fruit.
The relatively new technique of Solid-Phase Microextraction (SPME) offers a route to convenient in situ sampling. SPME combines in one-step sampling and preconcentration, prior to GC or GC-MS analysis.
Our research activity aims at developing methods of in situ SPME-GC analysis, and to develop a database of VOC emissions from Australian native vegetation.
Photo-oxidation of VOC’s from Australian vegetation
Oxidation of compounds emitted by plants occurs through a series of cyclic chain reactions, initiated principally by the hydroxyl radical, OH. Hydroxyl radicals are produced photolytically, hence the process is generally one of photo-oxidation. Products from this photo-oxidation are involved in a number of important atmospheric processes, including secondary organic aerosol (SOA) formation.
There has been very little exploration of the photo-oxidation reactions of VOC’s emitted in quantity by Australian vegetation, for instance, those of eucalyptol (1,8-cineole).
In this project, compounds of interest will be photo-oxidized under controlled conditions using the Indoor Smog Chamber at CSIRO Lucas heights and analysed via GC- and LC-MS after derivatisation.
The National Indigenous Science Education Program
The National Indigenous Science Education Program (NISEP) uses science to place Indigenous youth in leadership positions so they gain the confidence, motivation and skills to stay in school and consider pathways to higher education.
We bring together the voices that matter. NISEP is a unique collective of Aboriginal Elders, science academics and high school staff, committed to helping the educational attainment of Indigenous youth in a meaningful way.
We provide in-school, community and university science events. NISEP currently incorporates 13 high schools from low socioeconomic rural, regional and metro areas and 3 universities, and annually places around 150 Indigenous students in leadership roles. We are committed to working with our student leaders over their high school studies so as to strengthen their confidence and aspirations.
We help students broaden their ideas of what’s possible, develop confidence in their own abilities, and become role models in their communities. We are creating cycles of learning and leadership to improve educational outcomes for Indigenous youth, strengthen community ties and fost er a sense of pride and identity.
We want every student in Australia to have the chance to unlock their potential, ignite their imaginations and become our leaders of tomorrow.
The Pedagogy of Laboratory-Based Teaching and Learning
Laboratory-based teaching and learning is generally, but not universally, accepted as a fundamental element in science education. While our understanding of teaching and learning processes has advanced through education research, the application of this knowledge to the laboratory has lagged behind. We are interested in addressing a number of general educational questions relating to laboratory-based teaching and learning, such as what are the purposes of teaching in laboratories, what strategies are available for teaching in laboratories and how are they related to the purposes and how might we assess the outcomes of laboratory instruction? Of particular interest is identifying how generic skills and graduate attributes may be developed in the laboratory context. Laboratory work provides ample opportunities for students to cultivate skills such as collecting, analysing and organising information, communicating ideas and information, planning and organising activities, working alone and in teams, using mathematical ideas and techniques, solving problems and using technology.
Mathematics in Chemistry Education
Anecdotal evidence suggests that the many science students are finding the mathematical aspects of their courses to be difficult and therefore a barrier to their studies. We are interested in determining if anecdotal evidence can be supported by research, in discovering why this position has come about, and developing approaches to achieve the desired learning outcomes for our graduates, which includes the ability to use mathematical tools in a confident and competent manner.
Maths Anxiety in Chemistry Students
Mathematics anxiety is described in a number of ways, but the common themes are that a sufferer feels, to greater or lesser extent, panic, helplessness, paralysis, and mental disorganization. This may mean that the student stops him- or herself from starting on a task, even if capable of doing it. Students may be caught in a cycle of maths avoidance when, in the past, the student has suffered a bad experience relating to maths. The student then avoids mathematical tasks, resulting in poor mathematical preparation. This then leads to more negative maths experiences, reinforcing negative perceptions, and hence completing the cycle. In the milder form of this behaviour, simple reassurance and guidance may be sufficient to break the cycle. In the strong form, this will result in a true lack of mathematical preparation and a fear of doing anything about it. The protocol for dealing with students suffering from maths anxiety should be different from that for those students simply lacking adequate mathematical skills, but without anxiety. For this reason it is necessary to measure the extent of maths anxiety amongst the student cohort, and develop mechanisms for identifying these people early in their studies, so that appropriate support for them can be provided.
Chemical Misconceptions and Constructivism
“Constructivism” refers to the theory that the process of learning is not one of simple acceptance and remembrance of facts, but one where the learner must incorporate them into an already constructed world-view. If that world-view can not be modified to fit the new knowledge, then the knowledge is not retained. In other words, the learner must construct meaning for the knowledge for it to be preserved. It is therefore necessary for teachers to understand the ways in which students incorporate knowledge into their “world-views”. Students bring with them many preconceptions and/or misconceptions. These form the scaffolding on which students build all subsequent knowledge, unless they are distinguished, confronted and replaced or reconstructed in line with modern scientific thinking. Preconceptions in chemistry are extremely persistent. There is typically a rapid evolution in fundamental ideas about chemistry between the ages of 6 and 12, but only very slow change thereafter, in spite of intensive instruction in chemistry. These misconceptions are likely to still be present in tertiary level students, right through to those studying for their Ph.D.’s. It is important that teachers are aware of the range of preconceptions and misconceptions that students bring with them, and put in place appropriate teaching methods that adequately address these issues.