Resolution of Cryptic Species Complexes of Tephritid Pests to Enhance SIT Application and Facilitate International Trade

Tephritid fruit flies (Diptera: Tephritidae) are considered by far the most important group of horticultural pests worldwide. Female fruit flies lay eggs directly into ripening fruit, where the maggots feed causing fruit loss. Each and every continent is plagued by a number of fruit fly pests, both indigenous as well as invasive ones, causing tremendous economic losses. In addition to the direct losses through damage, they can negatively impact commodity trade through restrictions to market access. The quarantine and regulatory controls put in place to manage them are expensive, while the on-farm control costs and loss of crop affect the general well-being of growers. These constraints can have huge implications on loss in revenues and limitations to developing fruit and vegetable-based agroindustries in developing, emergent and developed nations. Because fruit flies are a global problem, the study of their biology and management requires significant international attention to overcome the hurdles they pose. The Joint Food and Agriculture Organisation / International Atomic Energy Agency (FAO/IAEA) Programme on Nuclear Techniques in Food and Agriculture has been on the foreground in assisting Member States in developing and validating environment-friendly fruit fly suppression systems to support viable fresh fruit and vegetable production and export industries. Such international attention has resulted in the successful development and validation of a Sterile Insect Technique (SIT) package for the Mediterranean fruit fly. Although demands for R&D support with respect to Mediterranean fruit fly are diminishing due to successful integration of this package into sustainable control programmes against this pest in many countries, there were increasing demands from Member States in Africa, Asia and Latin America, to address other major fruit fly pests and a related, but sometimes neglected issue of tephritid species complexes of economic importance. Any research, whether it is basic or applied, requires a taxonomic framework that provides reliable and universally recognized entities and names. Among the currently recognized major fruit fly pests, there are groups of species whose morphology is very similar or identical, but biologically they are distinct species. As such, some insect populations that are grouped taxonomically within the same pest species, display different biological and genetic traits and show reproductive isolation which suggest that they are different species. On the other hand, different species may have been taxonomically described, but there may be doubt as to whether they actually represent distinct biological species or merely geographical variants of the same species. This uncertain taxonomic status has practical implications on the effective development and use of the SIT against such complexes, particularly at the time of determining which species to mass-rear, and significantly affects international movement of fruit and vegetables through the establishment of trade barriers to important agricultural commodities which are hosts to these pest tephritid species...

Biomass based energy system for a South Indian village

The biomass resources, existing utilization levels and the efficiency of its use have been analyzed for a South Indian village. A biomass based energy efficient strategy has been devised to meet all the energy needs of the village, including substitution of fuels such as electricity and kerosene used in specific activities. Results indicate that the potential as well as the technologies exist for such substitutions. The proposed strategy will lead to an increase in the efficiency of energy use, reduce human drudgery and make villages more self reliant.

Phenotypic variation in natural populations of kikuyu in Australia

The quality of tropical grasses is a major limitation to animal production in tropical and subtropical areas. This is mainly associated with the lower digestibility because C4 grasses have higher fibre levels. Any improvement in quality would require a reduction in the lignin and an increase in the digestion of the neutral detergent fibre content of these plants (Clark and Wilson 1993). Kikuyu (Pennisetum clandestinum) is an important grass for the dairy and beef industries of the subtropics of Australia, South Africa and New Zealand (Mears 1970). Increased digestibility could substantially improve animal production in these industries. These experiments investigated the variation in agronomic and quality of natural populations selected from diverse regions within Australia. Runners of 14 kikuyu selections were collected by project staff or local agronomists from areas considered to have grown kikuyu for over 30 years while Whittet and Noonan were established by seed. Entries were established as single spaced plants on a 1.5 m grid in a randomised block with 3 replicates and evaluated under irrigation at Mutdapilly (brown podsol) and Wollongbar (red ferrosol). Foliage height, forage production and runner yield were assessed along with crude protein (CP), in vitro dry matter digestibility (IVDMD), metabolisable energy (ME), acid detergent fibre (ADF) and neutral detergent fibre (NDF) content of the leaf in autumn, winter and spring.

EMS in the pastoral industries of western Queensland: From customisation to implementation

This paper outlines the customisation of Environmental Management Systems (EMS) for the pastoral industry of western Queensland, the recruitment and training of pastoral producers, and their development and implementation of EMS. EMS was simplified to a 7-step process and producers were recruited to trial this customised EMS. Producers from 40 properties received EMS training, either as groups or individually. Of these, 37 commenced Pastoral EMS development through a facilitated approach that allowed them to learn about EMS while developing an EMS for their property. EMS implementation has been more effective with producers who were trained in groups. At this stage, however, most producers do not see value in EMS as there are currently no strong drivers to warrant continued development and implementation. Key findings resulting from this work were that personal contact and assistance is vital to encourage producers to trial EMS, and that a staged approach to EMS implementation, commencing with a self-assessment, is recommended. EMS training is most successful in a group situation; however, an alternative method of delivery should be provided for those producers who, either by choice or isolation, have to work alone. A support network is also necessary to encourage and maintain progress with EMS development and implementation, particularly where no strong drivers exist.

Improved bounds on the radius and curvature of the K pi scalar form factor and implications to low-energy theorems

We obtain stringent bounds in the < r(2)>(K pi)(S)-c plane where these are the scalar radius and the curvature parameters of the scalar K pi form factor, respectively, using analyticity and dispersion relation constraints, the knowledge of the form factor from the well-known Callan-Treiman point m(K)(2)-m(pi)(2), as well as at m(pi)(2)-m(K)(2), which we call the second Callan-Treiman point. The central values of these parameters from a recent determination are accomodated in the allowed region provided the higher loop corrections to the value of th form factor at the second Callan-Treiman point reduce the one-loop result by about 3% with F-K/F-pi = 1.21. Such a variation in magnitude at the second Callan-Treiman point yields 0.12 fm(2) less than or similar to < r(2)>(K pi)(S) less than or similar to 0.21 fm(2) and 0.56 GeV-4 less than or similar to c less than or similar to 1.47 GeV-4 and a strong correlation between them. A smaller value of F-K/F-pi shifts both bounds to lower values.

The economic value of new tropical biorefinery industries in Australia

Biorefineries, co-producing fuels, green chemicals and bio-products, offer great potential for enhancing agricultural value, and developing new industries in the bioeconomy. Biomass biorefineries aim to convert agricultural crops and wastes through biochemical and enzymatic processes to low cost fermentable sugars and other products which are platforms for value-adding. Through subsequent fermentation or chemical synthesis, the bio-based platforms can be converted to fuels including ethanol and butanol, oils, organic acids such as lactic and levulinic acid and polymer precursors. Other biorefinery products can include food and animal feeds, plastics, fibre products and resins. In 2014, QUT commissioned a study from Deloitte Access Economics and Correlli Consulting to assess the potential future economic value of tropical biorefineries to Queensland. This paper will report on the outcomes of this study and address the opportunities available for tropical biorefineries to contribute to the future profitability and sustainability of tropical agricultural industries in Queensland and more broadly across northern Australia.

Cellular Mechanisms of Sleep Homeostasis : Studies on Brain Energy Metabolism and Aging

Sleep is governed by a homeostatic process in which the duration and quality of previous wake regulate the subsequent sleep. Active wakefulness is characterized with high frequency cortical oscillations and depends on stimulating influence of the arousal systems, such as the cholinergic basal forebrain (BF), while cessation of the activity in the arousal systems is required for slow wave sleep (SWS) to occur. The site-specific accumulation of adenosine (a by-product of ATP breakdown) in the BF during prolonged waking /sleep deprivation (SD) is known to induce sleep, thus coupling energy demand to sleep promotion. The adenosine release in the BF is accompanied with increases in extracellular lactate and nitric oxide (NO) levels. This thesis was aimed at further understanding the cellular processes by which the BF is involved in sleep-wake regulation and how these processes are affected by aging. The BF function was studied simultaneously at three levels of organization: 1) locally at a cellular level by measuring energy metabolites 2) globally at a cortical level (the out-put area of the BF) by measuring EEG oscillations and 3) at a behavioral level by studying changes in vigilance states. Study I showed that wake-promoting BF activation, particularly with glutamate receptor agonist N-methyl-D-aspatate (NMDA), increased extracellular adenosine and lactate levels and led to a homeostatic increase in the subsequent sleep. Blocking NMDA activation during SD reduced the high frequency (HF) EEG theta (7-9 Hz) power and attenuated the subsequent sleep. In aging, activation of the BF during SD or experimentally with NMDA (studies III, IV), did not induce lactate or adenosine release and the increases in the HF EEG theta power during SD and SWS during the subsequent sleep were attenuated as compared to the young. These findings implicate that increased or continuous BF activity is important for active wake maintenance during SD as well as for the generation of homeostatic sleep pressure, and that in aging these mechanisms are impaired. Study II found that induction of the inducible NO synthase (iNOS) during SD is accompanied with activation of the AMP-activated protein kinase (AMPK) in the BF. Because decreased cellular energy charge is the most common cause for AMPK activation, this finding implicates that the BF is selectively sensitive to the metabolic demands of SD as increases were not found in the cortex. In aging (study III), iNOS expression and extracellular levels of NO and adenosine were not significantly increased during SD in the BF. Furthermore, infusion of NO donor into the BF did not lead to sleep promotion as it did in the young. These findings indicated that the NO (and adenosine) mediated sleep induction is impaired in aging and that it could at least partly be due to the reduced sensitivity of the BF to sleep-inducing factors. Taken together, these findings show that reduced sleep promotion by the BF contributes to the attenuated homeostatic sleep response in aging.

Sleep deprivation and brain energy metabolism : in vivo studies in rats and humans

Sleep deprivation leads to increased subsequent sleep length and depth and to deficits in cognitive performance in humans. In animals extreme sleep deprivation is eventually fatal. The cellular and molecular mechanisms causing the symptoms of sleep deprivation are unclear. This thesis was inspired by the hypothesis that during wakefulness brain energy stores would be depleted, and they would be replenished during sleep. The aim of this thesis was to elucidate the energy metabolic processes taking place in the brain during sleep deprivation. Endogenous brain energy metabolite levels were assessed in vivo in rats and in humans in four separate studies (Studies I-IV). In the first part (Study I) the effects of local energy depletion on brain energy metabolism and sleep were studied in rats with the use of in vivo microdialysis combined with high performance liquid chromatography. Energy depletion induced by 2,4-dinitrophenol infusion into the basal forebrain was comparable to the effects of sleep deprivation: both increased extracellular concentrations of adenosine, lactate, and pyruvate, and elevated subsequent sleep. This result supports the hypothesis of a connection between brain energy metabolism and sleep. The second part involved healthy human subjects (Studies II-IV). Study II aimed to assess the feasibility of applying proton magnetic resonance spectroscopy (1H MRS) to study brain lactate levels during cognitive stimulation. Cognitive stimulation induced an increase in lactate levels in the left inferior frontal gyrus, showing that metabolic imaging of neuronal activity related to cognition is possible with 1H MRS. Study III examined the effects of sleep deprivation and aging on the brain lactate response to cognitive stimulation. No physiologic, cognitive stimulation-induced lactate response appeared in the sleep-deprived and in the aging subjects, which can be interpreted as a sign of malfunctioning of brain energy metabolism. This malfunctioning may contribute to the functional impairment of the frontal cortex both during aging and sleep deprivation. Finally (Study IV), 1H MRS major metabolite levels in the occipital cortex were assessed during sleep deprivation and during photic stimulation. N-acetyl-aspartate (NAA/H2O) decreased during sleep deprivation, supporting the hypothesis of sleep deprivation-induced disturbance in brain energy metabolism. Choline containing compounds (Cho/H2O) decreased during sleep deprivation and recovered to alert levels during photic stimulation, pointing towards changes in membrane metabolism, and giving support to earlier observations of altered brain response to stimulation during sleep deprivation. Based on these findings, it can be concluded that sleep deprivation alters brain energy metabolism. However, the effects of sleep deprivation on brain energy metabolism may vary from one brain area to another. Although an effect of sleep deprivation might not in all cases be detectable in the non-stimulated baseline state, a challenge imposed by cognitive or photic stimulation can reveal significant changes. It can be hypothesized that brain energy metabolism during sleep deprivation is more vulnerable than in the alert state. Changes in brain energy metabolism may participate in the homeostatic regulation of sleep and contribute to the deficits in cognitive performance during sleep deprivation.

Electron energy loss spectroscopy (EELS) of H2O, H2S, H2Se and H2Te

Electronic excitation in H2O, H2S, H2Se and H2Te molecules has been studied by the EELS technique. Spectra of H2S and H2Se are remarkably similar with the 1b1-nd transition most intense. The intensity of the first transition 1b1-nsa1 decreases through H2O to H2Se and this transition is absent in H2Te. Transitions observed by EELS have been compared with optical absorption studies. A correlation diagram of the occupied and the excited states has been provided for these four molecules by making use of UVPES and EELS.

Fractional power dependence of rate on activation energy for reactions with very low internal barriers

The dynamics of reactions with low internal barriers are studied both analytically and numerically for two different models. Exact expressions for the average rate,kI, are obtained by solving the associated first passage time problems. Both the average rate constant, kI, and the numerically calculated long-time rate constant, kL, show a fractional power law dependence on the barrier height for very low barriers. The crossover of the reaction dynamics from low to high barrier is investigated.

A hydro-wood net-energy approach to hydro project design

An integrated approach to energy planning, when applied to large hydroelectric projects, requires that the energy-opportunity cost of the land submerged under the reservoir be incorporated into the planning methodology. Biomass energy lost from the submerged land has to be compared to the electrical energy generated, for which we develop four alternative formulations of the net-energy function. The design problem is posed as an LP problem and is solved for two sites in India. Our results show that the proposed designs may not be viable in net-energy terms, whereas a marginal reduction in the generation capacity could lead to an optimal design that gives substantial savings in the submerged area. Allowing seasonal variations in the hydroelectric generation capacity also reduces the reservoir size. A mixed hydro-wood generation system is then examined and is found to be viable.

Duckweed-based Wastewater Treatment Systems: Design Aspects and Integrated Reuse Options for Queensland Conditions

Point sources of wastewater pollution, including effluent from municipal sewage treatment plants and intensive livestock and processing industries, can contribute significantly to the degradation of receiving waters (Chambers et al. 1997; Productivity Commission 2004). This has led to increasingly stringent local wastewater discharge quotas (particularly regarding Nitrogen, Phosphorous and suspended solids), and many municipal authorities and industry managers are now faced with upgrading their existing treatment facilities in order to comply. However, with high construction, energy and maintenance expenses and increasing labour costs, traditional wastewater treatment systems are becoming an escalating financial burden for the communities and industries that operate them. This report was generated, in the first instance, for the Burdekin Shire Council to provide information on design aspects and parameters critical for developing duckweed-based wastewater treatment (DWT) in the Burdekin region. However, the information will be relevant to a range of wastewater sources throughout Queensland. This information has been collated from published literature and both overseas and local studies of pilot and full-scale DWT systems. This report also considers options to generate revenue from duckweed production (a significant feature of DWT), and provides specifications and component cost information (current at the time of publication) for a large-scale demonstration of an integrated DWT and fish production system.

Polychaete-assisted sand filters – prawn farm wastewater remediation trial

Medium bedding sand which is commonly available in coastal sedimentary deposits, and a marine polychaete-worm species from Moreton Bay recently classified as Perinereis helleri (Nereididae), were deployed in a simple low-maintenance sand filter design that potentially has application at large scale. Previous work had shown that this physical and biological combination can provide a new option for saline wastewater treatment, since the worms help to prevent sand filter blocking with organic debris and offer a profitable by-product. To test the application of this new concept in a commercial environment, six 1.84 m2 Polychaete-assisted sand filters were experimentally tested for their ability to treat wastewater from a semi-intensive prawn culture pond. Polychaetes produced exclusively on the waste nutrients that collected in these gravity-driven sand filters were assessed for their production levels and nutritional contents. Water parameters studied included temperature, salinity, pH, dissolved oxygen (DO), oxidation/ reduction potential (redox), suspended solids, chlorophyll a, biological oxygen demand (BOD), and common forms of nitrogen and phosphorus. Pond water which had percolated through the sand bed had significantly lower pH, DO and redox levels compared with inflow water. Suspended solids and chlorophyll a levels were consistently more than halved by the process. Reductions in BOD appeared dependant on regular subsurface flows. Only marginal reductions in total nitrogen and phosphorus were documented, but their forms were altered in a potentially useful way: dissolved forms (ammonia and orthophosphate) were generated by the process, and this remineralisation also seemed to be accentuated by intermittent flow patterns. Flow rates of approximately 1,500 L m-2 d-1 were achieved suggesting that a 1 ha polychaete bed of this nature could similarly treat the discharge from a 10 ha semi-intensive prawn farm. Sixteen weeks after stocking sand beds with one-month-old P. helleri, over 3.6 kg of polychaete biomass (wet weight) was recovered from the trial. Production on a sand bed area basis was 328 g m-2. Similar (P>0.05) overall biomass production was found for the two stocking densities tested (2000 and 6000 m-2; n = 3), but survival was lower and more worms were graded as small (<0.6 g) when produced at the higher density (28.2 ± 1.5 % and approx. 88 %, respectively) compared with the lower density (46.8 ± 4.4 % and approx. 76 %, respectively). When considered on a weight for weight basis, about half of the worm biomass produced was generally suitable for use as bait. The nutritional contents of the worms harvested were analysed for different stocking densities and graded sizes. These factors did not significantly affect their percentages of dry matter (DM) (18.23 ± 0.57 %), ash (19.77 ± 0.80 % of DM) or gross energy 19.39 ± 0.29 MJ kg-1 DM) (n = 12). Although stocking density did not affect the worms’ nitrogen and phosphorus contents, small worms had a higher mean proportion of nitrogen and phosphorus (10.57 ± 0.17 % and 0.70 ± 0.01 % of DM, respectively) than large worms (9.99 ± 0.12 % and 0.65 ± 0.01 % of DM, respectively) (n = 6). More lipid was present in large worms grown at the medium density (11.20 ± 0.19 %) compared with the high density (9.50 ± 0.31 %) and less was generally found in small worms (7.1-7.6 % of DM). Mean cholesterol and total phospholipid levels were 5.24 ± 0.15 mg g-1 and 13.66 ± 2.15 mg g-1 DM, respectively (n = 12). Of the specific phospholipids tested, phosphatidyl-serine or sphingomyelin were below detection limits (<0.05 mg g-1), whilst mean levels of phosphatidyl-ethanolamine, phosphatidyl-inositol, phosphatidyl-choline and lysophosphatidyl-choline were 6.89 ± 1.09, 0.89 ± 0.26, 4.04 ± 1.17 and 1.84 ± 0.37 mg g-1, respectively (n = 12). Culture density generally had a more pronounced effect on phospholipid contents than did size of worms. By contrast, worm size had a more pronounced effect on total fatty acid contents, with large worms containing significantly higher (P<0.001) levels on a DM basis (46.88 ± 2.46 mg g-1) than smaller worms (27.76 ± 1.28 mg g-1). A very broad range of fatty acids were detected with palmitic acid being the most heavily represented class (up to 14.23 ± 0.49 mg g-1 DM or 27.28 ± 0.22 % of total fatty acids). Other heavily represented classes included stearic acid (7.4-8.8 %), vaccenic acid (6.8-7.8 %), arachidonic acid (3.5-4.4 %), eicosapentaenoic acid (9.9-13.8 %) and docosenoic acid (5.7-7.0 %). Stocking density did not affect (P>0.05) the levels of amino acids present in polychaete DM, but there was generally less of each amino acid tested on a weight per weight basis in large worms than in small worms. This difference was significant (P<0.05) for the most heavily represented classes being glutamic acid (73-77 mg g-1), aspartic acid (50-54 mg g-1), and glycine (46-53 mg g-1). These results demonstrate how this polychaete species can be planted and sorted at harvest according to various strategies aimed at providing biomass with specific physical and nutritional qualities for different uses.