List of Records in School of Biological Sciences Publications - UQ eSpace

A bioinformatic approach to the identification of a conserved domain in a sugarcane legumain that directs GFP to the lytic vacuole

2008-05-08T08:57:15Z

Sugarcane is an ideal candidate as a biofactory for the production of alternate higher value products. One way of achieving this is to direct useful proteins into the vacuoles within the sugarcane storage parenchyma tissue. By bioinformatic analysis of gene sequences from putative sugarcane vacuolar proteins a motif has been identified that displays high conservation across plant legumain homologues that are known to function within vacuolar compartments. This. ve amino acid motif, represented by the sequence IRLPS in sugarcane is shown to direct an otherwise secreted GFP fusion protein into a large acidic and proteolytic vacuole in sugarcane callus cells as well as in diverse plant species. In mature sugarcane transgenic plants, the stability of GFP appeared to be dependent on cell type, suggesting that the vacuolar environment can be hostile to introduced proteins. This targeting motif will be a valuable tool for engineering plants such as sugarcane for production of novel products.

A broad-scale analysis of links between coastal fisheries production and mangrove extent: A case-study for northeastern Australia

2007-08-15T05:24:38Z

The paradigm that mangroves are critical for sustaining production in coastal fisheries is widely accepted, but empirical evidence has been tenuous. This study showed that links between mangrove extent and coastal fisheries production could be detected for some species at a broad regional scale (1000s of kilometres) on the east coast of Queensland, Australia. The relationships between catch-per-unit-effort for different commercially caught species in four fisheries (trawl, line, net and pot fisheries) and mangrove characteristics, estimated from Landsat images were examined using multiple regression analyses. The species were categorised into three groups based on information on their life history characteristics, namely mangrove-related species (banana prawns Penaeus merguiensis, mud crabs Scylla serrata and barramundi Lates calcarifer), estuarine species (tiger prawns Penaeus esculentus and Penaeus semisulcatus, blue swimmer crabs Portunus pelagicus and blue threadfin Eleutheronema tetradactylum) and offshore species (coral trout Plectropomus spp.). For the mangrove-related species, mangrove characteristics such as area and perimeter accounted for most of the variation in the model; for the non-mangrove estuarine species, latitude was the dominant parameter but some mangrove characteristics (e.g. mangrove perimeter) also made significant contributions to the models. In contrast, for the offshore species, latitude was the dominant variable, with no contribution from mangrove characteristics. This study also identified that finer scale spatial data for the fisheries, to enable catch information to be attributed to a particular catchment, would help to improve our understanding of relationships between mangroves and fisheries production. (C) 2005 Elsevier B.V. All rights reserved.

Absolute and relative abundance estimates of Australian east cost humpback whales (Megaptera novaeangliae)

Noad, M. J. og Cato, D. H. og Paton, D. — 2007-08-14T13:44:19Z

Abundance and demography of a seasonal aggregation of zebra sharks Stegostoma fasciatum

2009-02-02T13:21:23Z

Seasonal aggregations commonly occur in the marine environment where typically wide-ranging organisms come together to exploit temporary resources or find conspecifics for mating events. The zebra shark Stegostoma fasciatum is a demersal carpet shark that aggregates over the austral summer months in the coastal waters of southeast Queensland, Australia. This study employed photo-identification and mark-recapture methods over a 3 yr period (2003 to 2006) to investigate the population size and structure of this aggregation. In total 327 individual zebra sharks were identified from 570 photographs. Numbered dart-tags on 15 zebra sharks were used to confirm that pigmentation patterns were unique and persistent in wild zebra sharks for up to 810 d. Pollock’s robust design resulted in an annual population estimate of 458 individuals (95% CI = 298–618). The mean number of zebra sharks observed on a single day was 8 (± 8 SE) and the maximum number of zebra sharks seen on a single day was 34. In total, 27% of the sharks were sighted in more than one summer aggregation period and males had greater re-capture probabilities than females. The aggregation consisted exclusively of large (>1800 mm total length) adults with an overall female sex bias of 3.8:1 though sex-ratios varied temporally. Predictable visitation of large, presumably mature individuals to the site raises conservation concerns if aggregations of similar size and structure occur in regions where zebra sharks are fished.

Abundance, distribution, and availability of Trissolcus basalis (Wollaston) (Hymenoptera: Scelionidae) hosts in a soybean agricultural system in Southeastern Queensland

Loch, A. — 2008-06-10T11:42:33Z

Seasonal patterns of abundance and distribution of all life stages of known Trissolcus basalis (Wollaston) host species on different plant species in a soybean agricultural system in southeastern Queensland, Australia are reported. In particular, the seasonal phenology of different bug species is described with emphasis on periods of oviposition. Twelve hosts for T. basalis were identified, with three pentatomid bugs, green vegetable bug, green stink bug, and horehound bug, predominating. These three species appear to undergo at least three generations per year with mating and oviposition occurring during all months between September and April but mainly during October and January–April. Horehound bug is the only known T. basalis host that does not diapause during winter and continues to oviposit during winter at low levels. These results suggest that T. basalis is not host limited temporally except during winter when hosts are scarce. Results also show that T. basalis hosts are spatially aggregated at a number of levels, but how this affects T. basalis and the subsequent degree of biological control has yet to be investigated.

A butterfly eye’s view of birds

Frentiu, F. og Briscoe, A.D. — 2009-03-27T18:34:25Z

The striking color patterns of butterflies and birds have long interested biologists. But how these animals see color is less well understood. Opsins are the protein components of the visual pigments of the eye. Color vision has evolved in butterflies through opsin gene duplications, through positive selection at individual opsin loci, and by the use of filtering pigments. By contrast, birds have retained the same opsin complement present in early-jawed vertebrates, and their visual system has diversified primarily through tuning of the short-wavelength-sensitive photoreceptors, rather than by opsin duplication or the use of filtering elements. Butterflies and birds have evolved photoreceptors that might use some of the same amino acid sites for generating similar spectral phenotypes across 540 million years of evolution, when rhabdomeric and ciliary-type opsins radiated during the early Cambrian period. Considering the similarities between the two taxa, it is surprising that the eyes of birds are not more diverse. Additional taxonomic sampling of birds may help clarify this mystery

A calreticulin-like protein from endoparasitoid venom fluid is involved in host hemocyte inactivation

Zhang, G. M. og Schmidt, O. og Asgari, S. — 2007-08-15T09:40:24Z

During oviposition, most endoparasitoid wasps inject maternal factors into their hosts to interfere with host immune reactions and ensure successful development of their progeny. Since encapsulation is a major cellular defensive response of insects against intruding parasites, parasitoids have developed numerous mechanisms to suppress the host encapsulation capability by interfering with every step in the process, including recognition, adherence and spreading. In previous studies, components of Cotesia rubecula venom were shown to inhibit melanization of host hemolymph by interfering with the prophenoloxidase activation cascade and facilitate expression of polydnavirus genes. Here we report the isolation and characterization of another venom protein with similarity to calreticulin. Results indicate that C rubecula calreticulin (CrCRT) inhibits hemocyte spreading behavior, thus preventing encapsulation of the developing parasitoid. It is possible that the protein might function as an antagonist competing for binding sites with the host hemocyte calreticulin, which mediates early-encapsulation reactions. (c) 2005 Elsevier Ltd. All rights reserved.

A caspase-like gene from Heliothis virescens ascovirus (HvAV-3e) is not involved in apoptosis but is essential for virus replication

Asgari, S. — 2008-02-18T15:00:16Z

Ascoviruses (AVs) are double-stranded DNA viruses causing a fatal disease in lepidopteran host larvae. A unique feature of AV infection is cleavage of host cells into membrane bound vesicles containing the virions. A recent study showed that a caspase from Spodoptera frugiperda AV (SfAV) is directly involved in initiation of apoptosis and eventually cell cleavage. Results shown here indicate that Heliothis virescens AV does not induce apoptosis in host cells. HvAV codes for a caspase-like protein but no apoptosis was observed when the gene was expressed in vitro. RNAi studies indicated that the gene is essential for virus replication. (C) 2007 Elsevier B.V. All rights reserved.

Acclimation Of CTM, LD50 And Rapid Loss Of Acclimation Of Thermal Preferendum In Tadpoles Of Limnodynastes Peronii (Anura, Myobatrachidae)

Marshall, Elizabeth og Grigg, Gordon C. — 2004-11-12T00:00:00Z

Groups of tadpoles of Limnodynastes peronii (Anura, Myobatrachidae) were kept at two temperatures (15 degrees and 25 degrees Celsius) for 45-105 days. In a thermal gradient (6-36 degrees C), initial thermal preferenda were significantly different in 15 degrees and 25 degrees C history groups, approximately 13 degrees C and 21 degrees C respectively. However, after 2.5 hours, these initial differences were no longer seen and the final thermal preferendum was approximately 18 degrees C regardless of previous thermal history. Considering these results and the lack of metabolic acclimation reported elsewhere, these tadpoles can be seen as ecotherms whose thermal strategies are behavioural rather than physiological or biochemical. The rapid loss of acclimation of preferred temperature is discussed in relation to Fry's 'final preferendum' paradigm.

Acclimation of CTM, LD50, and Rapid Loss of Acclimation of Thermal Preferendum in Tadpoles of Limnodynastes peronii (Anura, Myobatrachidae)

Marshall, Elizabeth og Grigg, Gordon C. — 2005-04-06T00:00:00Z

Groups of tadpoles of Limnodynastes peronii (Anura, Myobatrachidae) were kept at two temperatures (15 degrees C and 25 degrees C) for 45-105 days. In a thermal gradient (6-36 degrees C), initial thermal preferenda were significantly different in 15 degrees C and 25 degrees C history groups, approximately 13 degrees C and 21 degrees C respectively. However, after 2.5 hours these initial differences were no longer seen and the final thermal preferendum was approximately 18 degrees C regardless of previous thermal history. Critical thermal maxima and LD50, increased following warm thermal history. Considering these results and the lack of metabolic acclimation reported elsewhere, these tadpoles can be seen as ectotherms whose thermal strategies are behavioural rather than physiological or biochemical. The rapid loss of acclimation of preferred temperature is discussed in relation to Fry's "final preferendum" paradigm.

Accounting for management costs in sensitivity analyses of matrix population models

2007-08-15T10:24:47Z

Traditional sensitivity and elasticity analyses of matrix population models have been used to p inform management decisions, but they ignore the economic costs of manipulating vital rates. For exam le, the growth rate of a population is often most sensitive to changes in adult survival rate, but this does not mean that increasing that rate is the best option for managing the population because it may be much more expensive than other options. To explore how managers should optimize their manipulation of vital rates, we incorporated the cost of changing those rates into matrix population models. We derived analytic expressions for locations in parameter space where managers should shift between management of fecundity and survival, for the balance between fecundity and survival management at those boundaries, and for the allocation of management resources to sustain that optimal balance. For simple matrices, the optimal budget allocation can often be expressed as simple functions of vital rates and the relative costs of changing them. We applied our method to management of the Helmeted Honeyeater (Lichenostomus melanops cassidix; an endangered Australian bird) and the koala (Phascolarctos cinereus) as examples. Our method showed that cost-efficient management of the Helmeted Honeyeater should focus on increasing fecundity via nest protection, whereas optimal koala management should focus on manipulating both fecundity and survival simultaneously, These findings are contrary to the cost-negligent recommendations of elasticity analysis, which would suggest focusing on managing survival in both cases. A further investigation of Helmeted Honeyeater management options, based on an individual-based model incorporating density dependence, spatial structure, and environmental stochasticity, confirmed that fecundity management was the most cost-effective strategy. Our results demonstrate that decisions that ignore economic factors will reduce management efficiency.

Achievement and challenge

McCallum, H. I. — 2008-06-10T12:46:59Z

Achilles and the mite: Zeno's paradox and rainforest mite diversity

Walter, D. E. — 2007-08-24T00:22:00Z

Acibenzolar-S-methyl-induced alteration of defence gene expression and enzyme activity in cotton infected with Fusarium oxysporum f. sp. vasinfectum

2009-11-11T15:11:44Z

The effect of acibenzolar-S-methyl (ASM) applied in the form of Bion® as a seed soak or a foliar spray, on transcript accumulation of six defence related genes, and activities of four defence related enzymes, was assessed after cotton was inoculated with Fusarium oxysporum f. sp. vasinfectum (Fov). Significant upregulation of chitinase class I, peroxidase, and β-1, 3-glucanase transcripts occurred in the Bion® seed soak treatment with Fov inoculation compared to all other treatments. Bion® alone did not significantly increase transcripts compared with water control treatments in the majority of cases. Phenylalanine ammonia lyase transcript in Bion® treated plants following fungal inoculation was greater than in the respective Bion® alone treatments, and osmotin-like protein transcript was significantly greater in inoculated plants sprayed with Bion® than in all other treatments. Transcripts of 4-coumarate-CoA ligase-like protein were generally lower than for all other genes, and significant upregulation compared with water control occurred in extracts from Fov inoculated plants receiving no Bion® treatment, and Fov inoculated plants cultivated from Bion® treated seed. The greatest increases in chitinase, β-1, 3-glucanase and peroxidase activity occurred in root and shoot tissue from Bion® seed treated material inoculated with Fov. Bion® treatment alone did not consistently enhance enzyme activities above those measured in water treated controls. Polyphenol oxidase activities were enhanced by various Bion® or Fov treatments at 3 days after inoculation only.

Acid–base regulation during hypercapnia, exercise and anoxia in the armoured catfish, Liposarcus pardalis

2009-02-25T12:58:22Z

During exposure to elevated water CO2 levels (hypercapnia), blood pH and tissue intracellular pH (pHi) in fish are initially reduced due to the rapid development of a respiratory acidosis. Blood pH recovery is associated with acid–base relevant ion transfer at the gills (i.e., Na+/H+ or Cl−/HCO3−), and generally occurs over 24–48 h during which time pHi recovery closely follows pH recovery of the blood. In the armoured catfish, Liposarcus pardalis, hypercapnia induces a large respiratory acidosis, but intracellular pH (pHi) of tissues such as the liver, heart and muscle is tightly regulated despite large reductions in plasma pH. Using an in situ perfused heart preparation, maximum cardiac performance (power output, cardiac output and stroke volume) was maintained at levels of up to 5% CO2 in L. pardalis. Maintenance of heart function under these conditions was associated with preferential pHi regulation. Following exhaustive exercise and 2 h of anoxia, there was little evidence for lactate incorporation into the skull or bony plates, but liver, heart and brain pHi were preferentially regulated despite a large uncompensated plasma acidosis, indicating that the type of acidosis does not alter the pattern of acid–base regulation in this species. This pattern of preferential pHi regulation differs markedly from that of most fish investigated to date; however, it has also been observed in two other facultative air-breathing fishes, Synbranchus marmoratus and Amia calva, and may be associated with the evolution of air-breathing.

A classification of subantarctic Heard Island vegetation

2007-08-14T17:10:56Z

The vascular and bryophyte floras of subantarctic Heard Island were classified using cluster analysis into six vegetation communities: Open Cushion Carpet, Mossy Feldmark, Wet Mixed Herbfield, Coastal Biotic Vegetation, Saltspray Vegetation, and Closed Cushion Carpet. Multidimensional scaling indicated that the vegetation communities were not well delineated but were continua. Discriminant analysis and a classification tree identified altitude, wind, peat depth, bryophyte cover and extent of bare ground, and particle size as discriminating variables. The combination of small area, glaciation, and harsh climate has resulted in reduced vegetation variety in comparison to those subantarctic islands north of the Antarctic Polar Front Zone. Some of the functional groups and vegetation communities found on warmer subantarctic islands are not present on Heard Island, notably ferns and sedges and fernbrakes and extensive mires, respectively.

A coiled-coil region of an insect immune suppressor protein is involved in binding and uptake by hemocytes

Asgari, S. og Schmidt, O. — 2007-08-13T12:56:23Z

Polydnaviruses are associated with certain parasitoid wasps and are introduced into the body cavity of the host caterpillar during oviposition. Some of the viral genes are expressed in host tissues and corresponding proteins are secreted into the hemocoel causing suppression of the host immune system. The Cotesia rubecula polydnavirus gene product, CrV1, effectively inactivates hemocytes by mediating cytoskeleton break-down. A precondition for the CrV1 function is the incorporation of the extracellular protein by hemocytes. Here, we show that a coiled-coil domain containing a putative leucine zipper is required for CrV1 function, since removal of this domain abolishes binding and uptake of the CrV1 protein by hemocytes. (C) 2002 Elsevier Science Ltd. All rights reserved.

A community based reforestation program for the conservation of forest culture in Madagascar

2008-06-06T15:08:52Z

A comparative map viewer integrating genetic maps for Brassica and Arabidopsis

2008-04-28T12:50:35Z

Background: Molecular genetic maps provide a means to link heritable traits with underlying genome sequence variation. Several genetic maps have been constructed for Brassica species, yet to date, there has been no simple means to compare this information or to associate mapped traits with the genome sequence of the related model plant, Arabidopsis. Description: We have developed a comparative genetic map database for the viewing, comparison and analysis of Brassica and Arabidopsis genetic, physical and trait map information. This web- based tool allows users to view and compare genetic and physical maps, search for traits and markers, and compare genetic linkage groups within and between the amphidiploid and diploid Brassica genomes. The inclusion of Arabidopsis data enables comparison between Brassica maps that share no common markers. Analysis of conserved syntenic blocks between Arabidopsis and collated Brassica genetic maps validates the application of this system. This tool is freely available over the internet on http://bioinformatics.pbcbasc.latrobe.edu.au/cmap. Conclusion: This database enables users to interrogate the relationship between Brassica genetic maps and the sequenced genome of A. thaliana, permitting the comparison of genetic linkage groups and mapped traits and the rapid identification of candidate genes.

A comparison of the performance and biological efficiency of new knapsack sprayers and a controlled droplet application (CDA) sprayer for the control of the diamondback moth, Plutella xylostella L. (Lepidoptera : Plutellidae)

2007-08-13T14:17:19Z

Field trials and laboratory bioassays were undertaken to compare the performance and efficacy (mortality of diamondback moth larvae) of insecticides applied to cabbages with three high volume hydraulic knapsack sprayers (NS-16, PB-20 and Selecta 12V) and a controlled droplet application (CDA) sprayer. In field experiments, the high volume knapsack sprayers (application rate 500-600 L ha(-1)) provided better spray coverage on the upper and lower surfaces of inner leaves, the upper surfaces of middle and outer leaves, and greater biological efficacy than the CDA sprayer (application rate 20similar to40 L ha(-1)). The PB-20 provided better spray coverage on the upper surface of middle leaves and both surfaces of outer leaves when compared with the Selecta 12V. However, its biological efficacy in the field was not significantly different from that of the other high volume sprayers. Increasing the application rate from 20 to 40 L ha(-1) for the CDA sprayer significantly increased droplet density but had no impact on test insect mortality. Laboratory evaluations of biological efficacy yielded higher estimates than field evaluations and there was no significant difference between the performance of the PB-20 and the CDA sprayer. Significant positive relationships were detected between insect mortality and droplet density deposited for both the PB-20 and the CDA sprayers.

A congruent molecular signature of vicariance across multiple plant linages

Crisp, M. D. og Cook, L. G. — 2008-04-14T15:18:03Z

A conservation plan for a global biodiversity hotspot - the Cape Floristic Region, South Africa

2007-09-19T16:40:51Z

We produced a conservation plan that achieved conservation targets for biodiversity pattern and process in the species- and endemic-rich Cape Floristic Region of South Africa. Features given quantitative conservation targets were land classes, localities of Proteaceae and selected vertebrate (freshwater fish, amphibians and reptiles) species, population sizes for medium- and large-sized mammals, and six types of spatial surrogates for ecological and evolutionary processes. The plan was developed in several stages using C-Plan, a decision support system linked to a geographic information system. Accepting the existing reserve system as part of the plan, we first selected spatially fixed surrogates for biodiversity processes; then we included those planning units that were essential for achieving targets for land classes, Proteaceae and vertebrate species; next we included areas required to accommodate population and design targets for large and medium-sized mammals; we then selected planning units required to conserve entire upland-lowland and macroclimatic gradients; and finally we resolved the options for achieving remaining targets while also consolidating the design of conservation areas. The result was a system of conservation areas, requiring, in addition to the existing reserve system, 52% of the remaining extant habitat in the planning domain, as well as restorable habitat, that will promote the persistence and continued diversification of much of the region's biota in the face of ongoing habitat loss and climate change. After describing the planning process, we discuss implementation priorities in relation to conservation value and vulnerability to habitat loss, as well as socio-economic, political and institutional. constraints and opportunities. (C) 2003 Elsevier Science Ltd. All rights reserved.

A critical reassessment of the cretaceous non-avian dinosaur faunas of Australia and New Zealand

2008-06-19T14:28:00Z

A critical review of the effects of gold cyanide-bearing tailings solutions on wildlife

2008-04-28T11:33:29Z

Wildlife deaths associated with cyanide-bearing mine waste solutions have plagued the gold mining industries for many years, yet there is little published data showing the relationship between wildlife mortality and cyanide toxicity. A gap of knowledge exists in monitoring, understanding the causal relationships and managing risks to wildlife from cyanide-bearing waste solutions and tailings. There is a need for the gold industry to address this issue and to meet the International Cyanide Management Code (ICMC) guidelines. The perceived extent of the issue varies, with one study finding the issue inadequately monitored and wildlife deaths grossly underestimated. In Nevada, USA during 1990 and 1991, 9512 carcasses were reported of over 100 species, although there was underestimation due to reporting being voluntary. Of these, birds comprised 80–91% of vertebrate carcasses reported annually. At Northparkes, Australia in 1995, it was initially estimated that 100 bird carcasses were present by mine staff following a tailings incident; when a thorough count was conducted, 1583 bird carcasses were recorded. Eventually, 2700 bird deaths were documented over a four-month period. It is identified that avian deaths are usually undetected and significantly underestimated, leading to a perception that a risk does not exist. Few guidelines and information are available to manage the risks of cyanide to wildlife, although detoxification, habitat modification and denying wildlife access have been used effectively. Hazing techniques have proven ineffective. Apparently no literature exists that documents accurate wildlife monitoring protocols on potentially toxic cyanide-bearing mine waste solutions or any understanding on the analysis of any derived dataset. This places the onus on mining operations to document that no risk to wildlife exists. Cyanide-bearing tailings storage facilities are environmental control structures to contain tailings, a standard practice in the mining industry. Cyanide concentrations below 50 mg/L weak-acid-dissociable (WAD) are deemed safe to wildlife but are considered an interim benchmark for discharge into tailings storage facilities (TSFs). Cyanide is a fast acting poison, and its toxicity is related to the types of cyanide complexes that are present. Cyanide in biota binds to iron, copper and sulfur-containing enzymes and proteins required for oxygen transportation to cells. The accurate determination of cyanide concentrations in the field is difficult to achieve due to sampling techniques and analytical error associated with loss and interferences following collection. The main WAD cyanide complexes in gold mine tailings are stable in the TSF environment but can release cyanide ions under varying environmental conditions including ingestion and absorption by wildlife. Therefore distinction between free, WAD and total cyanide forms in tailings water for regulatory purposes is justified. From an environmental perspective, there is a distinction between ore bodies on the basis of their copper content. For example, wildlife deaths are more likely to occur at mines possessing copper–gold ores due to the formation of copper–cyanide complexes which is toxic to birds and bats. The formation of copper–cyanide complex occurs preferentially to gold cyanide complex indicating the relative importance of economic vs. environmental considerations in the tailings water. Management of cyanide to a perceived threshold has inherent risks since cyanide has a steep toxicity response curve; is difficult to accurately measure in the field; and is likely to vary due to variable copper content of ore bodies and ore blending. Consequently, wildlife interaction needs to be limited to further reduce the risks. A gap in knowledge exists to design or manage cyanide-bearing mine waste solutions to render such facilities unattractive to at-risk wildlife species. This gap may be overcome by understanding the wildlife behaviour and habitat usage of cyanide-bearing solutions.

Active adaptive management for conservation

McCarthy, M. A. og Possingham, H. P. — 2008-02-18T14:32:43Z

Active adaptive management balances the requirements of management with the need to learn about the system being managed, which leads to better decisions. It is difficult to judge the benefit of management actions that accelerate information gain, relative to the benefit of making the best management decision given what is known at the time. We present a first step in developing methods to optimize management decisions that incorporate both uncertainty and learning via adaptive management We assumed a manager can allocate effort to discrete units (e.g., areas for revegetation or animals for reintroduction), the outcome can be measured as success or failure (e.g., the revegetation in an area is successful or the animal survives and breeds), and the manager has two possible management options from which to choose. We further assumed that there is an annual budget that may be allocated to one or both of the two options and that the manager must decide on the allocation. We used Bayesian updating of the probability of success of the two options and stochastic dynamic programming to determine the optimal strategy over a specified number of years, The costs, level of certainty about the success of the two options, and the timeframe of management all influenced the optimal allocation of the annual budget. In addition, the choice of management objective had a large influence on the optimal decision. In a case study of Merri Creek, Melbourne, Australia, we applied the approach to determining revegetation strategies. Our approach can be used to determine how best to manage ecological systems in the face of uncertainty.

Active Adaptive Management in Insect Pest and Weed Control: Intervention with a Plan for Learning

2006-02-10T00:00:00Z

A major problem in insect pest and weed management is uncertainty. Managers are faced with three main types of uncertainty: uncertainty about biological and environmental processes, and observational uncertainty. Active adaptive management (AAM) is management with a deliberate plan for learning about the managed system, so that management can be improved in the face of uncertainty. We discuss the potential benefits of applying AAM to insect pest and weed control with reference to a number of examples. We first address the possible uses for AAM in biological control, with particular reference to agent selection and release. We also propose applying AAM methods to resistance management and to spatial strategies for pest control. We conclude with an overview of AAM, a discussion of some of the potential limitations to its use in pest management, and the possibilities for increased implementation of AAM in the future.

Activity patterns and oviposition rates of Aphytis lingnanensis females, a parasitoid of California red scale Aonidiella aurantii: implications for successful biological control

Fernando, L. C. og Walter, G. H. — 2008-06-10T13:49:28Z

Acute symptoms, not rectally administered sucralfate, predict for late radiation proctitis: Longer term follow-up of a phase III trial - trans-Tasman radiation oncology group

2007-08-14T17:31:44Z

Image : To assess the potential for sucralfate administered rectally to reduce the risk of late rectal morbidity in patients undergoing nonconformal radiotherapy (RT) for carcinoma of the prostate and to study the variables potentially contributing to late rectal morbidity and particularly to explore the relationship between acute and late toxicity. Image : Eighty-six patients with localized prostate carcinoma were randomized in a double-blind, placebo-controlled study to a daily enema of 3 g of sucralfate in a 15-mL suspension or the same suspension without sucralfate. The enema began the first day of RT and was continued for 2 weeks after treatment completion. The primary end point of the study was acute Radiation Therapy Oncology Group (RTOG)/European Organization for Research and Treatment of Cancer (EORTC) toxicity; however, the patients were followed for an additional 5 years on a 6-month basis. The evaluation included late RTOG/EORTC toxicity and a patient self-assessment questionnaire. Image : With a median follow-up of 5 years, the Kaplan-Meier probability of late Grade 2 RTOG/EORTC toxicity was 12% (95% confidence interval [CI] 2–22%) for placebo and 5% (95% CI 0–12%) for sucralfate (p = 0.26). The probability of late rectal bleeding was 59% (95% CI 45–73%) for placebo and 54% (95% CI 40–68%) for sucralfate. No statistically significant difference was found between the treatment arms for the peak incidence of any of the other patient self-assessment variables. Cox proportional hazards modeling indicated acute RTOG/EORTC toxicity of Grade 2 or greater was associated with a hazard ratio of 2.74 (95% CI 1.31–5.73) for the development of late toxicity of Grade 1 or greater. Substituting the patient self-assessment variables for acute RTOG/EORTC toxicity revealed that rectal pain of a moderate or severe grade during RT was the best predictor of the subsequent development of late toxicity, with a hazard ratio of 3.44 (95% CI 1.68–7). Image : The results of this study do not support the use of sucralfate administered rectally as a method for reducing the late toxicity of nonconformal RT for prostate cancer. There appears to be an association between the development of acute and subsequent late toxicity, although the nature of this association remains to be determined

Adaptation of rainbow fish to lake and stream habitats

2007-08-14T19:05:34Z

Fish occupy a range of hydrological habitats that exert different demands on locomotor performance. We examined replicate natural populations of the rainbow fishes Melanotaenia eachamensis and M. duboulayi to determine if colonization of low-velocity (lake) habitats by fish from high-velocity (stream) habitats resulted in adaptation of locomotor morphology and performance. Relative to stream conspecifics, lake fish had more posteriorly positioned first dorsal and pelvic fins, and shorter second dorsal fin bases. Habitat dimorphism observed between wild-caught fish was determined to be heritable as it was retained in M. eachamensis offspring raised in a common garden. Repeated evolution of the same heritable phenotype in independently derived populations indicated body shape divergence was a consequence of natural selection. Morphological divergence between hydrological habitats did not support a priori expectations of deeper bodies and caudal peduncles in lake fish. However, observed divergence in fin positioning was consistent with a family-wide association between habitat and morphology, and with empirical studies on other fish species. As predicted, decreased demand for sustained swimming in takes resulted in a reduction in caudal red muscle area of lake fish relative to their stream counterparts. Melanotaenia duboulayi lake fish also had slower sustained swimming speeds (U-crit) than stream conspecifics. In M. eachamensis, habitat affected U-crit of males and females differently. Specifically, females exhibited the pattern observed in M. duboulayi (lake fish had faster U-crit than stream fish), but the opposite association was observed in males (stream males had slower Ucrit than lake males). Stream M. eachamensis also exhibited a reversed pattern of sexual dimorphism in U-crit (males slower than females) relative to all other groups (males faster than females). We suggest that M. eachamensis males from streams responded to factors other than water velocity. Although replication of muscle and U,,it phenotypes across same habitat populations within and/or among species was suggestive of adaptation, the common garden experiment did not confirm a genetic basis to these associations. Kinematic studies should consider the effect of the position and base length of dorsal fins.

Adaptations of strangler figs to life in the rainforest canopy

Schmidt, S. og Tracey, D. P. — 2007-08-15T08:19:58Z

Figs are rainforest keystone species. Non-strangler figs establish on the forest floor; strangler figs establish epiphytically, followed by a dramatic transition from epiphyte to free-standing tree that kills its hosts. Free-standing figs display vigorous growth and resource demand suggesting that epiphytic strangler figs require special adaptations to deal with resource limitations imposed by the epiphytic environment. We studied epiphytic and free-standing strangler figs, and non-strangler figs in tropical rainforest and in cultivation, as well as strangler figs in controlled conditions. We investigated whether the transition from epiphyte to free-standing tree is characterised by morphological and physiological plasticity. Epiphyte substrate had higher levels of plant-available ammonium and phosphate, and similar levels of nitrate compared with rainforest soil, suggesting that N and P are initially not limiting resources. A relationship was found between taxonomic groups and plant N physiology; strangler figs, all members of subgenus Urostigma, had mostly low foliar nitrate assimilation rates whereas non-strangler figs, in subgenera Pharmacocycea, Sycidium, Sycomorus or Synoecia, had moderate to high rates. Nitrate is an energetically expensive N source, and low nitrate use may be an adaptation of strangler figs for conserving energy during epiphytic growth. Interestingly, significant amounts of nitrate were stored in fleshy taproot tubers of epiphytic stranglers. Supporting the concept of plasticity, leaves of epiphytic Ficus benjamina L. had lower N and C content per unit leaf area, lower stomatal density and 80% greater specific leaf area than leaves of conspecific free-standing trees. Similarly, glasshouse-grown stranglers strongly increased biomass allocation to roots under water limitation. Epiphytic and free-standing F. benjamina had similar average foliar delta C-13, but epiphytes had more extreme values; this indicates that both groups of plants use the C-3 pathway of CO2 fixation but that water availability is highly variable for epiphytes. We hypothesise that epiphytic figs use fleshy stem tubers to avoid water stress, and that nitrate acts as an osmotic compound in tubers. We conclude that strangler figs are a unique experimental system for studying the transition from rainforest epiphyte to tree, and the genetic and environmental triggers involved.

Adaptive Evolution of Color Vision as Seen through the Eyes of Butterflies

2009-03-03T11:09:50Z

Butterflies and primates are interesting for comparative color vision studies, because both have evolved middle- (M) and long-wavelength- (L) sensitive photopigments with overlapping absorbance spectrum maxima (λmax values). Although positive selection is important for the maintenance of spectral variation within the primate pigments, it remains an open question whether it contributes similarly to the diversification of butterfly pigments. To examine this issue, we performed epimicrospectrophotometry on the eyes of five Limenitis butterfly species and found a 31-nm range of variation in the λmax values of the L-sensitive photopigments (514–545 nm). We cloned partial Limenitis L opsin gene sequences and found a significant excess of replacement substitutions relative to polymorphisms among species. Mapping of these L photopigment λmax values onto a phylogeny revealed two instances within Lepidoptera of convergently evolved L photopigment lineages whose λmax values were blue-shifted. A codon-based maximum-likelihood analysis indicated that, associated with the two blue spectral shifts, four amino acid sites (Ile17Met, Ala64Ser, Asn70Ser, and Ser137Ala) have evolved substitutions in parallel and exhibit significant dN/dS >1. Homology modeling of the full-length Limenitis arthemis astyanax L opsin placed all four substitutions within the chromophore-binding pocket. Strikingly, the Ser137Ala substitution is in the same position as a site that in primates is responsible for a 5- to 7-nm blue spectral shift. Our data show that some of the same amino acid sites are under positive selection in the photopigments of both butterflies and primates, spanning an evolutionary distance >500 million years.

Adding a Fifth Gene to the Ramosus branching model

2008-06-06T16:37:22Z

Additional signalling compounds are required to orchestrate plant development

2007-08-15T02:12:42Z

Plants are necessarily complex systems that require monitoring of multiple environmental signals and, in response to those signals, coordination of differentiation and development of an extensive array of cell types at multiple locations. This coordination must rely on integration of long-distance signals that provide a means of communication among different plant parts. We propose that the relatively well-characterized classical phytohormones must act with several other long-distance signals to achieve this level of organization with dynamic yet measured responses. This is supported by observations that classical phytohormones: (i) operate in complex yet experimentally unresolved networks involving cross-talk and feedback, (ii) are generally multifunctional and nonspecific and hence must rely on other long-distance cues or pre-set conditions to achieve specificity and (iii) are likely to mask roles of other long-distance signals in several experimental contexts. We present evidence for involvement of novel long-distance signals in three developmental processes-branching, flowering and nodulation, and discuss the possible identities of novel signalling molecules.

Addressing Interindividual Variation within a Science Dissection-based Anatomy Course

Aland, Rachel C. og Kippers, Vaughan — 2009-04-09T16:01:18Z

A DHA14 drug efflux gene from Xanthomonas albilineans confers high-level albicidin antibiotic resistance in Escherichia coli

2007-08-15T09:40:49Z

Aims: Identification of a gene for self-protection from the antibiotic-producing plant pathogen Xanthomonas albilineans, and functional testing by heterologous expression. Methods and Results: Albicidin antibiotics and phytotoxins are potent inhibitors of prokaryote DNA replication. A resistance gene (albF) isolated by shotgun cloning from the X. albilineans albicidin-biosynthesis region encodes a protein with typical features of DHA14 drug efflux pumps. Low-level expression of albF in Escherichia coli increased the MIC of albicidin 3000-fold, without affecting tsx-mediated albicidin uptake into the periplasm or resistance to other tested antibiotics. Bioinformatic analysis indicates more similarity to proteins involved in self-protection in polyketide-antibiotic-producing actinomycetes than to multi-drug resistance pumps in other Gram-negative bacteria. A complex promoter region may co-regulate albF with genes for hydrolases likely to be involved in albicidin activation or self-protection. Conclusions: AlbF is the first apparent single-component antibiotic-specific efflux pump from a Gram-negative antibiotic producer. It shows extraordinary efficiency as measured by resistance level conferred upon heterologous expression. Significance and Impact of the Study: Development of the clinical potential of albicidins as potent bactericidial antibiotics against diverse bacteria has been limited because of low yields in culture. Expression of albF with recently described albicidin-biosynthesis genes may enable large-scale production. Because albicidins are X. albilineans pathogenicity factors, interference with AlbF function is also an opportunity for control of the associated plant disease.

A DNA-based diagnostic test for 'tropical' race 4 of Fusarium wilt of banana

2007-08-24T00:15:38Z

A DNA fingerprinting procedure for ultra high-throughput genetic analysis of insects

2007-08-14T15:54:39Z

Existing procedures for the generation of polymorphic DNA markers are not optimal for insect studies in which the organisms are often tiny and background molecular Information is often non-existent. We have used a new high throughput DNA marker generation protocol called randomly amplified DNA fingerprints (RAF) to analyse the genetic variability In three separate strains of the stored grain pest, Rhyzopertha dominica. This protocol is quick, robust and reliable even though it requires minimal sample preparation, minute amounts of DNA and no prior molecular analysis of the organism. Arbitrarily selected oligonucleotide primers routinely produced similar to 50 scoreable polymorphic DNA markers, between individuals of three Independent field isolates of R. dominica. Multivariate cluster analysis using forty-nine arbitrarily selected polymorphisms generated from a single primer reliably separated individuals into three clades corresponding to their geographical origin. The resulting clades were quite distinct, with an average genetic difference of 37.5 +/- 6.0% between clades and of 21.0 +/- 7.1% between individuals within clades. As a prelude to future gene mapping efforts, we have also assessed the performance of RAF under conditions commonly used in gene mapping. In this analysis, fingerprints from pooled DNA samples accurately and reproducibly reflected RAF profiles obtained from Individual DNA samples that had been combined to create the bulked samples.

A Double-Survey Estimate Of Population Size From Incomplete Counts

2005-02-25T00:00:00Z

We sought to estimate the number of crocodile nests on the Liverpool River, Northern Territory, Australia. Two methods of survey were available, aerial survey and ground survey, in each of which sightings could be mapped. Hence, those nests which were detected by both methods could be identified. These counts were used to demonstrate the method by which an estimate of total number could be calculated. The assumptions and limitations are discussed.

Aerial Survey of Kangaroos in South Australia 1978-1998: A Brief Report Focusing on Methodology

2005-04-06T00:00:00Z

Twenty-one surveys have been conducted using a Cessna 182 in the pastoral zone of South Australia, covering the twenty year period 1978 to 1998, flying the same transects and using the same method. Considerable attention has been given to observer training and the turnover rate of observers has been low. The same pilot has flown all surveys. The pastoral zone is bounded in the north and west by a dingo-proof fence. Large lakes and areas of terrain above 2000 ft elevation (notably the Flinders Ranges) were excluded from the survey, leaving a surveyed area of approximately 207 000 square km. Surveys are conducted each year in July/August, with morning and afternoon survey sessions. Transects run east/west and are 15 nautical miles (28km) apart. The method has followed what has become the standard for fixed-wing surveys: a height of 250ft (76m) above ground (AGL), a ground speed of 100 knots (185 km h-1), 5 km unit lengths (97 sec.) with a 7 sec. pause between each and animals counted in 200 m wide strips each side of the aircraft, demarcated by streamers attached to the wing struts. A radar altimeter is used to maintain height above the terrain and, since 1989, a global positioning system has been used to ensure adherence to the transect and to maintain the required groundspeed. Red kangaroos, western grey kangaroos, common wallaroos, emus and goats are counted and other macro fauna noted (camels, horses, dingoes, ostriches, etc.). Standard correction factors have been applied throughout, except that, in the present paper, the data are recalculated to reflect the outcomes of this workshop concerning a move to modified correction factors. The results have highlighted the responsiveness of kangaroo populations to rainfall and pasture availability. There has been a statistically significant long-term trend towards higher numbers of western grey kangaroos in the study area, and a similar trend in reds since the end of the 1982/1983 drought. Over the 20 years, however, there has been no statistically significant trend to either higher or lower numbers of red kangaroos. Some analyses of the data obtained by aerial survey have already been presented and, in due course, further analyses will be presented elsewhere. Importantly, the results provide a useful demonstration that long-term harvesting can be carried out without detriment to the populations.

Aeronautical Aspects Of Biological Aerial Surveys

Grigg, Gordon C. — 2005-02-28T00:00:00Z

Aspects of aircraft operation relevant to planning and execution of aerial surveys are discussed. Regulations governing the operation of light aircraft in Australia and the aeronautical limitations of such aircraft operating at low attitude and low speed are discussed as constraints within which aerial surveys must be designed and carried out. For surveys to be effective it is essential that both pilot and biologist know a little of each other's profession.

Aeropalynology of Australian native arboreal species in Brisbane, Australia

2007-08-15T03:27:43Z

The influence of meteorological parameters on airborne pollen of Australian native arboreal species was investigated in the sub-tropical city of Brisbane, Australia over the five-year period, June 1994–May 1999. Australian native arboreal pollen (ANAP), shed by taxa belonging to the families Cupressaceae, Casuarinaceae and Myrtaceae accounts for 18.4% of the total annual pollen count and is distributed in the atmosphere during the entire year with maximum loads restricted to the months May through November. Daily counts within the range 11–100 grains m–3 occurred over short intervals each year and were recorded on 100 days during the five-year sampling period. Total seasonal ANAP concentrations varied each year, with highest annual values measured for the family Cupressaceae, for which greater seasonal frequencies were shown to be related to pre-seasonal precipitation (r 2 = 0.76, p = 0.05). Seasonal start dates were near consistent for the Cupressaceae and Casuarinaceae. Myrtaceae start dates were variable and established to be directly related to lower average pre-seasonal maximum temperature (r 2 = 0.78, p = 0.04). Associations between daily ANAP loads and weather parameters showed that densities of airborne Cupressaceae and Casuarinaceae pollen were negatively correlated with maximum temperature (p < 0.0001), minimum temperature (p < 0.0001) and precipitation (p < 0.05), whereas associations with daily Myrtaceae pollen counts were not statistically significant. This is the first study to be conducted in Australia that has assessed the relationships between weather parameters and the airborne distribution of pollen emitted by Australian native arboreal species. Pollen shed by Australian native Cupressaceae, Casuarinaceae and Myrtaceae species are considered to be important aeroallergens overseas, however their significance as a sensitising source in Australia remains unclear and requires further investigation.

A falsification of the thermal specialization paradigm: compensation for elevated temperatures in Antarctic fishes

2007-08-15T05:50:57Z

Specialization to a particular environment is one of the main factors used to explain species distributions. Antarctic fishes are often cited as a classic example to illustrate the specialization process and are regarded as the archetypal stenotherms. Here we show that the Antarctic fish Pagothenia borchgrevinki has retained the capacity to compensate for chronic temperature change. By displaying astounding plasticity in cardiovascular response and metabolic control, the fishes maintained locomotory performance at elevated temperatures. Our falsification of the specialization paradigm indicates that the effect of climate change on species distribution and extinction may be overestimated by current models of global warming.

A Fetal-Maternal Shift of Blood Oxygen Affinity in an Australian Viviparous Lizard, Sphenomorphus quoyii (Reptilia, Scincidae)

Grigg, Gordon C. og Harlow, Peter — 2005-09-15T00:00:00Z

Compared to adults, the oxygen affinity of blood from fetal Sphenomorphus quoyii is very much higher: P50 is approximately 70 Torr in adults and 30 Torr in nearly full term embryos (PC02= 17 Torr, T=34 degrees C). Following birth, oxygen affinity decreases gradually and adult values are approached after about 15 weeks, with the onset of winter retreat. Electrophoresis revealed a multiple hemoglobin system in both adults and embryos, but there were no apparent differences between them.

Affinities of Lantana camara in the Australia-Pacific Region

2007-08-24T01:06:20Z

Affinities of the family Sollasellidae (Porifera, Demospongiae). II. Molecular evidence

2008-05-15T12:23:32Z

This is the second part of a revision and re-classification of the demosponge family Sollasellidae, and an example of a successful use of combined morphological and molecular data. Sollasella had been a poorly known, long forgotten taxon, placed incertae sedis in the order Hadromerida in the last major revision of the demosponges. It has recently been suggested to belong to Raspailiidae in the order Poecilosclerida due to striking morphological similarities. The present analysis verified this re-classification using molecular markers. Comparing 28S rDNA fragments of Sollasella cervicornis, a newly described species S. moretonensis and a representative set of raspailiid and hadromerid samples. In our analyses Sollasella clearly clusters inside the Raspailiidae clade, and distantly from hadromerid taxa. Supporting morphological hypothesis of Van Soest et al. (2006), that Sollasella is a raspailiid sponge.

A framework for the study of genetic variation in migratory behaviour

2007-08-15T08:17:36Z

Evolutionary change results from selection acting on genetic variation. For migration to be successful, many different aspects of an animal's physiology and behaviour need to function in a co-coordinated way. Changes in one migratory trait are therefore likely to be accompanied by changes in other migratory and life-history traits. At present, we have some knowledge of the pressures that operate at the various stages of migration, but we know very little about the extent of genetic variation in various aspects of the migratory syndrome. As a consequence, our ability to predict which species is capable of what kind of evolutionary change, and at which rate, is limited. Here, we review how our evolutionary understanding of migration may benefit from taking a quantitative-genetic approach and present a framework for studying the causes of phenotypic variation. We review past research, that has mainly studied single migratory traits in captive birds, and discuss how this work could be extended to study genetic variation in the wild and to account for genetic correlations and correlated selection. In the future, reaction-norm approaches may become very important, as they allow the study of genetic and environmental effects on phenotypic expression within a single framework, as well as of their interactions. We advocate making more use of repeated measurements on single individuals to study the causes of among-individual variation in the wild, as they are easier to obtain than data on relatives and can provide valuable information for identifying and selecting traits. This approach will be particularly informative if it involves systematic testing of individuals under different environmental conditions. We propose extending this research agenda by using optimality models to predict levels of variation and covariation among traits and constraints. This may help us to select traits in which we might expect genetic variation, and to identify the most informative environmental axes. We also recommend an expansion of the passerine model, as this model does not apply to birds, like geese, where cultural transmission of spatio-temporal information is an important determinant of migration patterns and their variation.

A framework of lessons learned from community-based marine reserves and its effectiveness in guiding a new coastal management initiative in the Philippines

2007-08-15T05:22:19Z

Age and growth in olive ridley seaturtles (Lepidochelys olivacea) from the north-central Pacific: a skeletochronological analysis

2007-08-15T08:24:01Z

The olive ridley is the most abundant seaturtle species in the world but little is known of the demography of this species. We used skeletochronological data on humerus diameter growth changes to estimate the age of North Pacific olive ridley seaturtles caught incidentally by pelagic longline fisheries operating near Hawaii and from dead turtles washed ashore on the main Hawaiian Islands. Two age estimation methods [ranking, correction factor (CF)] were used and yielded age estimates ranging from 5 to 38 and 7 to 24 years, respectively. Rank age-estimates are highly correlated (r = 0.93) with straight carapace length (SCL), CF age estimates are not (r = 0.62). We consider the CF age-estimates as biologically more plausible because of the disassociation of age and size. Using the CF age-estimates, we then estimate the median age at sexual maturity to be around 13 years old (mean carapace size c. 60 cm SCL) and found that somatic growth was negligible by 15 years of age. The expected age-specific growth rate function derived using numerical differentiation suggests at least one juvenile growth spurt at about 10–12 years of age when maximum age-specific growth rates, c. 5 cm SCL year−1, are apparent.

Age determination in individual wild-caught Drosophila serrata using pteridine concentration

2007-08-15T08:24:03Z

Fluorescence spectrophotometry can reliably detect levels of the pteridine 6-biopterin in the heads of individual Drosophila serrata Malloch 1927. Pteridine content in both laboratory and field captured flies is typically a level of magnitude higher than the minimally detectable level (mean(lab)=0.54 units, mean(field)=0.44 units, minimum detectable level=0.01 units) and can be used to predict individual age in laboratory populations with high certainty (r(2)=57%). Laboratory studies of individuals of known age ( from 1 to 48 days old) indicate that while pteridine level increases linearly with age, they also increase in a linear manner with rearing temperature and ambient light levels, but are independent of sex. As expected, the longevity of laboratory-reared males ( at least 48 days) is higher than the range of predicted ages of wild-caught males based on individual pteridine levels (40 days). However, the predictive equation based on pteridine level alone suggested that a number of wild-caught males were less than 0 days old, and the 95% confidence for these predictions based on the inverse regression broad. The age of the oldest wild-caught male is to fall within the range of 2 to 50 days. The effects of temperature and light intensity determined in laboratory study (effect sizes omega(2)=14.3 and respectively) suggests that the calibration of the prediction equation for field populations would significantly improved when combined with fine scaled studies of habitat temperature and light conditions. ability to determine relative age in individual wild-caught D. serrata presents great opportunities for a variety evolutionary studies on the dynamics of populations.

Age estimation of Eretmochelys imbricata by sclerochronology of carapacial scutes

2007-08-14T16:46:47Z