Recent publications in Science and Engineering

College of Science and Engineering Recent publications in Science and Engineering

Miller, Mark G.R., Carlile, Nicholas, Phillips, Joe Scutt, McDuie, Fiona, and Congdon, Bradley C. (2018) The importance of tropical tuna for seabirds foraging over a marine productivity gradient. Marine Ecology Progress Series. (In Press)
Foraging with tuna is a well-documented seabird strategy, referred to as facilitated foraging. However, despite this behaviour being considered almost obligatory in nutrient-poor tropical waters, little data exist on its relative importance to individual colonies. Therefore, to examine facilitated foraging under different patterns of nutrient availability we tracked Wedge-tailed Shearwaters Ardenna pacifica from two colonies, one tropical and one subtropical, situated in waters of contrasting productivity. Shearwater foraging behaviour was assessed relative to oceanographic covariates and predicted distributions for multiple tropical tuna species and age-classes, simulated by an existing ecosystem model (SEAPODYM). Shearwaters from both colonies undertook long-trips to deep, pelagic waters close to seamounts and foraged most often at fronts and eddies. Micronektonic and adult tuna age-classes were highly correlated in space. Predation between these tuna age-classes represents a likely source of facilitated foraging opportunities for shearwaters. At broad-scales, shearwaters consistently foraged in areas with higher predicted adult skipjack and micronektonic tuna densities and avoided adult bigeye tuna. At finer-scales, dynamic ocean features aggregated tuna of all sizes. Enhanced tuna density at these locations increased the likelihood of shearwater foraging activity. Long-trips in the tropics targeted oligotrophic waters with higher tuna densities. Long-trips in the subtropics targeted enhanced productivity, but in some years shifted to target the same oligotrophic, tuna-dense waters used by tropical conspecifics. We conclude that facilitated foraging with tuna is consistently important to the tropical breeding population and becomes increasingly important to the subtropical population in years of low marine productivity.

Neal, Luke C., Wilkinson, Jamie J., Mason, Philippa J., and Chang, Zhaoshan (2018) Spectral characteristics of propylitic alteration minerals as a vectoring tool for porphyry copper deposits. Journal of Geochemical Exploration, 184 (Part A). pp. 179-198.
Short-wave infrared (SWIR) reflectance spectroscopy is a quick and effective method of detecting and characterising hydrothermal alteration associated with ore deposits, and can identify not only mineral species but also changes in the major element composition of minerals. Porphyry deposits represent large accumulations of valuable metal in the Earth's crust and have extensive alteration signatures making them an attractive target for exploration, particularly by remote sensing which can cover large areas quickly. Reflectance spectroscopy has been widely applied in sericitic (phyllic), argillic and advanced argillic alteration domains because it is particularly effective in discriminating bright clay minerals. However, the propylitic domain has remained relatively unexplored because propylitic rocks are typically dark and produce relatively poorly-defined spectra. This study utilised an ASD TerraSpec 4 handheld spectrometer to collect SWIR spectra from rocks surrounding the Batu Hijau Cu-Au porphyry deposit in Indonesia, where previous work has identified systematic spatial variations in the chemistry of chlorite, a common propylitic alteration mineral. Spectra were collected from 90 samples and processed using The Spectral Geologist (TSG) software as well as the Halo mineral identifier to characterise mineralogy and extract the positions and depths of spectral absorption features, which were then correlated with major element geochemistry. Two diagnostic chlorite absorption features located at around 2250 nm and 2340 nm correlate with the Mg# (Mg/[Mg +Fe]) of chlorite, both in terms of wavelength position and depth. As the Mg# increases, the wavelengths of both features increase from 2249 nm to 2254 nm and from 2332 nm to 2343 nm respectively, and absorption depths also increase significantly. In the spatial dimension, these feature variations act as reasonably strong vectors to the orebody, showing systematic increases over a transect away from the porphyry centre, peaking at distances of around 1.6 km, which matches the spatial trend displayed by Mg#, as well as various trace element indicators in chlorite. The hull slope in spectra between 1400 nm and 1900 nm is also shown to increase with Mg#, and the position of an absorption feature at 1400 nm increases with the Al:Si ratio, a parameter that also tends to increase with proximity to porphyry deposits. Feature depth variations in particular appear to represent a new finding in chlorite reflectance spectroscopy; however, the causes are not entirely clear and require further investigation. Nonetheless, the systematic behaviour provides a potentially useful new tool for exploration in propylitic alteration zones.

Sims, K. (2018) More growth, less freedom? charting development pathways in Lao PDR. In: Howe, Brendan, (ed.) National Security, Statecentricity, and Governance in East Asia. Security, Development and Human Rights in East Asia . Palgrave Macmillan, Cham, Switzerland, pp. 127-149.
According to macro-scale measures and indicators the principal development narrative for Lao PDR is one of strong economic growth and continued socio-economic progress. However, the true complexity of socio-economic transformations to have occurred in the country are not easily captured by reductive macro-scale indices. In this chapter I problematize development success narratives surrounding Lao PDR by bringing attention to the relationship between persistent socio-economic challenges and the state’s poor track record on human rights and political freedoms. Here, I argue: (1) that privileging economic growth over political freedom is a threat to sustained poverty-alleviation; (2) the common myth that economic liberalization naturally leads to democratic reform is unlikely to materialize in Lao PDR, and; (3) attempts by foreign donors to depoliticize socio-economic inequalities have bolstered a regime that is responsible for intolerable human rights abuses.

Taufa, Shalon, Munns, Suzanne, and Edwards, Will (2017) Smoking, particulate fuel use, increasing BMI (but not betel use) increase the probability of obstructive airway conditions in adults fron National Capital District, PNG. In: [Presented at PNG Impact: Research Innovation Society], pp. 80-81. From: PNG Impact: Research Innovation Society, 12-13 Dec 2017, Port Moresby, Papua New Guinea.
Exposure to tobacco smoke and particulates from biomass fuel smoke are a risk factors for Chronic Obstructive Pulmonary Disease (COPD). Papua New Guinea has a high prevalence of smoking, which is a leading cause of COPD. In addition to tobacco use, many families in PNG also use fuels producing particulate smoke for cooking (e.g. wood, charcoal or kerosene) which may further increase the risk of developing lung disease. The chewing of Betel nut (Areca catechu) is also prevalent in PNG, and has been shown to cause bronchoconstriction in asthmatic patients. This study was conducted to determine the relative contribution of smoking, particulate fuel use, and betel use have on the probability of developing obstructive lung disease. A prospective cross-sectional study measured the lung function of apparently healthy adults residing in the National Capital District. Lung function was assessed using spirometry, which was conducted according to the American Thoracic Society guidelines. Seventy-six subjects met the inclusion criteria out of hundred and forty volunteers. Smoking and biomass smoke inhalation both independently increased the probability of decreased lung function as measured by a %FEV1/FVC less than 80% of the predicted value. The use of betel was not found to significantly alter the probability of lowering %FEV1/FVC below 80% of predicted values. Interesting, increasing BMI was found to increase the probability of decreasing lung function in smokers who did not use particulate fuels and in particulate fuel users who did not smoke, and was most significant in smokers who used particulate fuels. Understanding the interactive effects between COPD risk factors will help predict health outcomes in PNG and increase public education on COPD prevention.

Younes Cárdenas, Nicolás, Joyce, Karen E., and Maier, Stefan W. (2017) Monitoring mangrove forests: are we taking full advantage of technology? International Journal of Applied Earth Observation and Geoinformation, 63. pp. 1-14.
Mangrove forests grow in the estuaries of 124 tropical countries around the world. Because in-situ monitoring of mangroves is difficult and time-consuming, remote sensing technologies are commonly used to monitor these ecosystems. Landsat satellites have provided regular and systematic images of mangrove ecosystems for over 30 years, yet researchers often cite budget and infrastructure constraints to justify the underuse this resource. Since 2001, over 50 studies have used Landsat or ASTER imagery for mangrove monitoring, and most focus on the spatial extent of mangroves, rarely using more than five images. Even after the Landsat archive was made free for public use, few studies used more than five images, despite the clear advantages of using more images (e.g. lower signal-to-noise ratios). The main argument of this paper is that, with freely available imagery and high performance computing facilities around the world, it is up to researchers to acquire the necessary programming skills to use these resources. Programming skills allow researchers to automate repetitive and time-consuming tasks, such as image acquisition and processing, consequently reducing up to 60% of the time dedicated to these activities. These skills also help scientists to review and re-use algorithms, hence making mangrove research more agile. This paper contributes to the debate on why scientists need to learn to program, not only to challenge prevailing approaches to mangrove research, but also to expand the temporal and spatial extents that are commonly used for mangrove research.

Gibson, Luke, Wilman, Elspeth N., and Laurance, William F. (2017) How green is 'green' energy? Trends in Ecology & Evolution, 32 (12). pp. 922-935.
Renewable energy is an important piece of the puzzle in meeting growing energy demands and mitigating climate change, but the potentially adverse effects of such technologies are often overlooked. Given that climate and ecology are inextricably linked, assessing the effects of energy technologies requires one to consider their full suite of global environmental concerns. We review here the ecological impacts of three major types of renewable energy – hydro, solar, and wind energy – and highlight some strategies for mitigating their negative effects. All three types can have significant environmental consequences in certain contexts. Wind power has the fewest and most easily mitigated impacts; solar energy is comparably benign if designed and managed carefully. Hydropower clearly has the greatest risks, particularly in certain ecological and geographical settings. More research is needed to assess the environmental impacts of these 'green' energy technologies, given that all are rapidly expanding globally.

Sims, Kearrin (2017) Gambling on the future: casino enclaves, development, and poverty alleviation in Laos. Pacific Affairs, 90 (4). pp. 675-700.
Following the extraordinary wealth generation of casinos in Macau and Singapore, governments and non-state actors across Southeast Asia have developed gambling establishments as a means to fast-track economic growth and stimulate national development. Yet, here and elsewhere, casinos have been heavily criticized for their association with immoral behaviour, problem gambling, corruption and organized crime. In this article I focus on two casinos in northern Laos to address two research questions. First, I consider how casinos have come to exist within the remote border regions of one of Asia’s least developed countries. Here, I discuss vice economies within the Golden Triangle region, multi-actor aspirations to boost transnational connectivity within continental Southeast Asia, strengthening political-economic relationships between Laos and China, and Government of Laos efforts to use foreign investment as a mechanism for increasing governance capacities in borderlands. Following this, I critically analyse how, in what ways, and for whom, casinos have brought development to Laos. Here, I focus specifically on the multifarious effects of casinos on the lives and livelihoods of local communities to argue that casino development has been informed by logics of expulsion and the establishment of new predatory formations. To make this argument, the article draws on four fieldwork visits to each of the casino sites between 2011 and 2015, desk-based research, and interviews with local residents, casino staff and members of the Government of Laos.

Antunes, Elsa, Jacob, Mohan V., Brodie, Graham, and Schneider, Philip A. (2017) Silver removal from aqueous solution by biochar produced from biosolids via microwave pyrolysis. Journal of Environmental Management, 203 (Part 1). pp. 264-272.
The contamination of water with silver has increased due to the widespread applications of products with silver employed as antimicrobial agent. Adsorption is a cost-effective method for silver removal from aqueous solution. In this study biochar, produced from the microwave assisted pyrolysis of biosolids, was used for silver removal from an aqueous solution. The adsorption kinetics, isotherms and thermodynamics were investigated to better understand the silver removal process by biochar. X-ray diffraction results demonstrated that silver removal was a combination two consecutive mechanisms, reduction and physical adsorption. The Langmuir model fitted the experimental data well, showing that silver removal was predominantly a surface mechanism. The thermodynamic investigation demonstrated that silver removal by biochar was an exothermic process. The final nanocomposite Ag-biochar (biochar plus silver) was used for methylene blue adsorption and photodegradation. This study showed the potential of using biochar produced from biosolids for silver removal as a promising solution to mitigate water pollution and an environmentally sustainable approach for biosolids management and re-use.

Parackal, K.I., Ginger, J.D., and Henderson, D.J. (2017) Correlation of peak wind loads at batten-truss connections. In: Proceedings of the 24th Australasian Conference on the Mechanics and Structures and Materials, pp. 1899-1904. From: ACMSM24: 24th Australasian Conference on the Mechanics of Structures and Materials, 6-10 December 2016, Perth, WA, Australia.
Wind loads on roofs fluctuate significantly, both across their surfaces and in time. A 1/50 scale wind tunnel study was conducted to determine the correlations of these load fluctuations on batten to truss connections. This study found that load histories between neighbouring connections are correlated and are sensitive to wind direction. Critical wind directions that cause the highest uplift loads are not necessarily those that experience the highest correlations amongst neighbouring connections. Additionally, for different wind directions loads at connections to the left, right or diagonally across from the critical connections are more correlated, suggesting that the path that a progressive failure takes is dependent on wind direction and the location on the roof where it initiates.

Miller, Mark G.R., Silva, Fabiola R.O., Machovsky-Capuska, Gabriel E., and Congdon, Bradley C. (2017) Sexual segregation in tropical seabirds: drivers of sex-specific foraging in the Brown Booby Sula leucogaster. Journal of Ornithology. (In Press)
Sexual segregation in the behaviour, morphology or physiology of breeding seabirds can be related to divergent parental roles, foraging niche partitioning or sex-specific nutritional requirements. Here we combine GPS tracking, dietary and nutritional analysis to investigate sex-specific foraging of Brown Boobies breeding on Raine Island, Great Barrier Reef, Australia. We observed sex-specific segregation in: a) foraging location: females undertook longer trips, foraging at more distant locations than males; b) foraging time: male activity and foraging occurred throughout the day, while female activity and foraging increased from midday to an afternoon peak; and c) prey type, females mostly consumed flying fish, whereas males consumed equal proportions of flying fish and squid. Brown Booby diets contained five tropical prey species that significantly differed in their nutritional composition (Protein, Lipid and Water, wet mass). Despite this variation we found no differences in the overall nutritional content of prey caught by each sex. The observed sex-specific differences in prey type, location and time of capture are likely driven by a combination of a division of labour, risk partitioning and competition. However, Brown Boobies breeding on Raine Island, and other populations, might flexibly partition foraging niche by sex in response to varying competitive and environmental pressures. In light of such potential foraging dynamism, our inconclusive exploration of nutritional segregation between sexes warrants further investigation in the species.

Cairns, Andi, and Meagher, David (2017) Significant range extensions and new records of mosses from tropical Australia. Telopea, 20. pp. 277-287.
We report Pleuridium nervosum and Pseudotaxiphyllum pohliaecarpum as new to the Australian Wet Tropics bioregion, and Fabronia brachyphylla and Pleuridium nervosum as new to the adjacent Einasleigh Uplands bioregion. We also report significant range extensions for other species, and new records of several very rare species including Distichophyllum mittenii, Entodontopsis pygmaea, Meiotheciella papillosa, Philonotis slateri, Rhynchostegium nanopennatum, and Trachythecium verrucosum.

Shiel, Brett P., Hall, Nathan E., Cooke, Ira R., Robinson, Nicholas A., Stone, David A.J., and Strugnell, Jan M. (2017) The effect of commercial, natural and grape seed extract supplemented diets on gene expression signatures and survival of greenlip abalone (Haliotis laevigata) during heat stress. Aquaculture, 479. pp. 798-807.
Summer mortality is a phenomenon associated with high temperature water spikes that can result in mass mortalities of abalone and other molluscs. This is a particular concern for aquaculture industries due to the economic impacts of such events. Diets containing algal supplements have been suggested as pre-emptive solutions for preventing these mass mortalities. The same has also been suggested for diets containing grape seed extract. This is due to their potential as a source of antioxidative compounds, which reduce the accumulation of harmful reactive oxygen species. This study aimed to identify functional genes associated with high survival in abalone fed diets high in antioxidative compounds during heat stress. Tentacle transcriptomes of 40 greenlip abalone (Haliotis laevigata) were investigated to determine the combined effects of differing diets and temperature on the gene expression responses by abalone. Here we compare the functional gene expression changes at 22 degrees C and 25 degrees C in abalone fed common commercial, live macroalgal (Ulva lactuca) and grape seed extract supplemented commercial diets as a means to understand the resulting high survival of abalone fed grape seed extract during heat stress. Twenty-four genes were differentially expressed between high survival promoting diets (macroalgae or grape seed extract supplemented commercial) relative to the purely commercial diet. Many of these genes have been suggested to be involved in antioxidant and innate immunity responses. The identification of these genes and their functional roles has enhanced our understanding of processes that contribute to summer stress resilience in abalone. Our study supports the hypothesis that diet and gene expression signatures may be indicative of the survival capabilities of abalone when exposed to heat stress.

Kosov, D.S. (2017) Restoring the Pauli principle in the random phase approximation ground state. Chemical Physics Letters, 690. pp. 20-24.
Random phase approximation ground state contains electronic configurations where two (and more) identical electrons can occupy the same molecular spin-orbital violating the Pauli exclusion principle. This overcounting of electronic configurations happens due to quasiboson approximation in the treatment of electron-hole pair operators. We describe the method to restore the Pauli principle in the RPA wavefunction. The proposed theory is illustrated by the calculations of molecular dipole moments and electronic kinetic energies. The Hartree–Fock based RPA, which is corrected for the Pauli principle, gives the results of comparable accuracy with Møller-Plesset second order perturbation theory and coupled-cluster singles and doubles method.

Schlaefer, Jodie A., Wolanski, Eric, Kingsford, Michael J., and schlaef, (2017) Swimming behaviour can maintain localised jellyfish (Chironex fleckeri: Cubozoa) populations. Marine Ecology Progress Series. (In Press)
The potentially lethal Chironex fleckeri (Class Cubozoa) inhabits estuarine and nearshore coastal waters in the western Pacific. The spatial scales of connectivity between C. fleckeri populations are poorly understood. Biophysical modelling of Port Musgrave, a 17 × 21 km shallow bay in tropical Australia, was used to investigate the potential for connections between populations separated by medium (10s of km) to small (100s of m) spatial scales. We measured the swimming speeds and orientations of medusae ranging in size from 4 to 12 cm interpedalial distance (the distance between two adjacent corners on the bell of the medusae). Medusae swam longshore at average speeds (5.3 ± 3.5 cm s-1 SD) that exceeded the local average current speeds (2.7 ± 2.4 cm s-1). These and other ecological data were used to parameterise the biophysical model. No medusae modelled as passive were advected from the bay in 14 d; <2.5% of swimming medusae were lost. When medusae swam directionally, a high percentage aggregated in shallow waters within 10s to 100s of m of the seeding locations. Newly metamorphosed medusae are likely to be retained in the bay through a combination of ‘sticky water’ (i.e. water with reduced current speeds, reduced through diversion around obstacles) in shallow complex habitats and favourable currents. C. fleckeri are vulnerable to low salinities; however, modelling a strong flood revealed higher salinity refugia in shallow water. As there was high retention within the system, we conclude that populations of C. fleckeri inhabiting shallow, semi-enclosed estuarine bays probably represent stocks. Within these stocks, swimming and favourable currents may minimise connectivity and maintain populations at multiple spatial scales.

Konovalov, D.A., Domingos, J.A., Bajema, C., White, R.D., and Jerry, D.R. (2017) Ruler detection for automatic scaling of fish images. In: Proceedings of the International Conference on Advances in Image Processing, pp. 90-95. From: ICAIP 2017: International Conference on Advances in Image Processing, 25-27 August 2017, Bangkok, Thailand.
Fast and low-cost image collection and processing is often required in aquaculture farms for quality/size attributes and breeding programs. For example, the absolute physical dimensions of fish (in millimeters or inches) could be estimated from electronic images. The absolute scale of the photographed fish is often unknown or requires additional hardware, data- collection and/or management overheads. One cost and time effective solution is to capture the absolute scale (in pixels-per- millimeter or dots-per-inch) by including a measuring ruler in the photographed scene. To assist that type of workflow, this paper presents a relatively simple image-processing algorithm that automatically located a sufficiently large section of the ruler in a given image. The algorithm utilized the Fast Fourier Transform and was designed to be free from adjustable parameters and therefore did not require training. The algorithm was tested on 445 images of Barramundi (Asian sea bass, Lates calcarifer), where a millimeter-graded ruler was included in each image. The algorithm achieved precision of 98% (on the original, 10, 20, 70, 80 90 degree rotated images) and 95-96% on 40, 50, 60 degree rotated images. The test Barramundi images were released to public domain (on this publication) via https://github.com/dmitryako/BarraRulerDataset445.

Nuske, Susan Joy (2017) The importance of declining mammalian fungal specialists for ectomycorrhizal fungal dispersal. PhD thesis, James Cook University.
Conservation is more than just preserving biodiversity but also preserving ecosystem processes. Understanding how loss of diversity can affect the functioning of ecosystems requires understanding of the system's functional redundancy. That is, how many species in the system perform similar roles and can compensate for the loss of similar species? In this thesis, I investigate the functional redundancy among mammal species involved in an important, yet poorly understood, interaction between three very different organisms; fungi, plants and mammals. Mycorrhizal fungi associate mutualistically with the roots of many plant species. In exchange for nutrients accessed by the fungi, the plants provide the fungus with sugars (carbohydrates) from their photosynthesis. Many mycorrhizal species form below-ground fruit-bodies (truffles) that rely on mammals for spore dispersal. This interaction led to the hypothesis that mammals are important for fungal species diversity, plant-fungal interactions and ecosystem functioning. However, little is known about how truffles contribute to the structure of mycorrhizal communities. For instance, are truffle taxa that mammals disperse important components of the mycorrhizal community as a whole and thus, can mammals influence mycorrhizal community structure? Globally, many different mammals are known to consume and disperse truffles, some to a much greater degree than others. For example, the term 'fungal specialists' is used for mammals that consume fungi for the majority of their diet (>50%, relative to other food types). Often as a consequence, fungal specialists can also consume (and disperse) a diversity of truffle species. Many mammals with generalist diets, on the other hand, frequently consume truffle fungi opportunistically. Hence, individual mammals with generalist diets often consume a lower diversity of truffle fungal species than mammals with fungal specialist diets. However, currently it is unknown whether the combined fungal dispersal role of mammals with generalist diets equates to that of a specialist (i.e.: is there functional redundancy in the system?). In other words, if a fungal specialist were to become extinct in an ecosystem, is there enough functional redundancy that the dispersal roles for truffle fungi will be fulfilled by the remaining mammals with generalist diets? Understanding this interaction is particularly relevant to Australian ecosystems. Unfortunately, Australia has the highest rate of mammal extinction and decline, including fungal specialists within the family Potoroidae. Additionally, the majority of Australia's native forests are dominated by woodland trees that host truffle-producing ectomycorrhizal (ECM) fungi (for instance, Eucalyptus, Corymbia, Allocasuarina, Melaleuca). In this thesis, I addressed a number of research questions aimed at better understanding how the loss of mammalian diversity could potentially impact on truffle populations and mycorrhizal communities. These research results pave the way to understanding how loss of mammal diversity could influence fungus-plant interactions and ecosystem functioning. In Chapter Two, a meta-analysis brings together discordant data on fungal diets of mammals across Australia. These data were used to ask whether there is functional redundancy in fungal dispersal roles among mammalian fungal specialists and mammals with generalist diets. Despite detecting a sampling bias in the literature, on average, fungal specialists consumed fungi at a higher diversity and abundance, and more consistently across seasons than mycophagous mammals with generalist diets, indicating little functional redundancy in general. However, some generalist mammals ate a fungal species diversity on par with specialists (Rattus fuscipes, Perameles nasuta and Wallabia bicolor) indicating that there may be functional redundancy in some systems. Studies presented in this meta-analysis utilised differences in morphological characters of spores to identify fungal species, however, this technique has limited resolution with some groups (e.g. Russulaceae). Additionally, much of the data could not be compared between studies because many taxa were undescribed (e.g. Unknown species 1). Results from Chapter Two are built on in Chapter Three, by directly comparing fungal diets of a specialist and nine co-occurring generalist fungal diets using modern DNA sequencing techniques. This direct comparison eliminated the biases associated with using data collected from different studies and allowed a higher resolution of fungal species diversity to be measured. I found that the fungal specialist, Bettongia tropica (northern bettong), consumed a significantly higher diversity and more unique mycorrhizal and truffle fungal taxa than the combined diets of the generalists. Bettongia tropica also had a significantly different fungal community in their diets. These trends were consistent across sites and seasons. These data suggest that there is little functional redundancy in this ecosystem and indicates that truffle fungi populations may be detrimentally impacted by the loss of the endangered B. tropica. To further understand whether potential loss of truffle taxa, via loss of specialists, would have detrimental impacts on fungal-plant interactions, a good understanding of the structure of the mycorrhizal community must first be obtained. Yet, particularly in Australia, little is known about the structure of mycorrhizal communities and how truffle diversity contributes to it. In Chapter Four, this knowledge gap was addressed by measuring the mycorrhizal community at different scales using molecular methods. I found that the dominant mycorrhizal fungal taxa associating with plant roots were truffle taxa found in mycophagous mammalian diets. Over 80% of truffle taxa associating with roots were within the diet of the fungal specialist, and this percentage was just over half (52%) for generalist mammals. These data indicate that mammals, particularly those with specialist fungal diets, are important in shaping ECM fungal communities. This adds credence to the hypothesis that the loss of mammals could have detrimental effects on ECM communities and fungal-plant relationships. Overall, my thesis addressed key knowledge gaps in the interactions between mycophagous mammals, ECM fungi and their host plants. This work also highlights previously overlooked ramifications of native mammal loss in Australia, drawing particular attention to specialist mycophagists whose role in maintaining the diversity of ECM truffle fungal taxa may be irreplaceable.

Madanayaka, Thushara Asela, and Sivakugan, Nagaratnam (2017) Adaptation of method of fragments to axisymmetric cofferdam seepage problems. International Journal of Geomechanics, 17 (9).
The method of fragments can be used to efficiently obtain solutions to a variety of two-dimensional seepage problems, especially confined flow problems. With this method, the flow domain is divided into fragments that span zones, which are defined between certain critical planes, based on the assumption that the equipotential lines through each such plane are coincident with the plane(s) in question. A dimensionless form factor is then defined for each fragment, and the total flow rate is computed using these form factors in a straightforward manner. An extension of the method of fragments to the axisymmetric cofferdam problem is presented in this paper. A range of numerical simulations was used to generate design charts to obtain the required axisymmetric form factors and exit gradients. These were validated against detailed numerical solutions and against analytical solutions reported in the literature. The design charts presented in this paper are considered to provide very reliable estimates of the seepage conditions and for a wide range of cofferdam geometries of practical interest.

Ramsay, Helen, Cairns, Andi, and Meagher, David (2017) Macromitrium erythrocomum (Bryophyta: Orthotrichaceae), a new species from tropical Queensland, Australia. Telopea, 20. pp. 261-268.
Macromitrium erythrocomum sp. nov. is described from the Wet Tropics bioregion, Queensland, Australia. It is distinguished mainly by its large size, excurrent red costa, unusual areolation of the upper leaf lamina, short seta, hairy calyptra, peristome absent or reduced to a low basal membrane, and anisomorphic spores. A comparison is made with other Macromitrium species in the region.

Jaditager, Mohamed, and Sivakugan, Nagaratnam (2017) Influence of fly ash-based geopolymer binder on the sedimentation behaviour of dredged mud. Journal of Waterway, Port, Coastal, and Ocean Engineering, 143 (5). pp. 1-9.
This laboratory study investigated the sedimentation behavior of a fly ash–based geopolymer-stabilized dredged-mud slurry extracted from the Port of Townsville, Queensland, Australia. Settling-column tests were conducted to study the sedimentation behavior of 400%-water-content dredged mud of untreated and geopolymer-stabilized slurries at 6, 12, and 18% content by weight. Dredged-mud slurry interface height movements with elapsed time were recorded, and their settling patterns were observed. Mineralogical and microstructural characteristics of dried, untreated, and geopolymer-stabilized dredged-mud sediments were determined using X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) analysis. The study found that a fly ash–based geopolymer gel coating the dredged-mud particles in the slurry led to a flocculated settling behavior, and the geopolymer stabilization reduced the overall dredged-mud slurry sedimentation duration. XRD and SEM/EDS analysis showed that the geopolymer stabilization altered the microstructure of stabilized dredged-mud sediment and reduced its desiccation shrinkage cracks.

Rowen, David J., Templeman, Michelle A., and Kingsford, Michael J. (2017) Herbicide effects on the growth and photosynthetic efficiency of Cassiopea maremetens. Chemosphere, 182. pp. 143-148.
Herbicides from agricultural run-off have been measured in coastal systems of the Great Barrier Reef over many years. Non-target herbicide exposure, especially photosystem II herbicides has the potential to affect seagrasses and other marine species. The symbiotic benthic jellyfish Cassiopea maremetens is present in tropical/sub-tropical estuarine and marine environments. Jellyfish were exposed to agricultural formulations of diuron or hexazinone to determine their sensitivity and potential for recovery to pulsed herbicide exposure. Jellyfish growth, symbiont photosynthetic activity and zooxanthellae density were analysed for herbicide-induced changes for 7 days followed by a 7 day recovery period. Both the jellyfish and endosymbiont were more sensitive to diuron than hexazinone. The 7-day EC50 for jellyfish growth was 0.35 µg.L-1 for Diuron and 17.5 µg.L-1 for Hexazinone respectively. Diuron exposure caused a significant decrease in(p<0.05) in jellyfish growth at all concentrations and at levels0.1 µg.L-1, a level that is below the regional Great Barrier Reef guideline valuesvalue. Jellyfish recovery was rapid with growth rates similar to control animals following removal from herbicide exposure. Both diuron and hexazinone caused significant decreases in photosynthetic efficiency (effective quantum yield) in all treatment concentrations (0.1 µg.L-1 and above) and this effect continued in the post-exposure period. As this species is frequently found in near-shore environments, they may be particularly vulnerable to herbicide run-off.

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