Straightforward data management at QUT

QUT Library Research Support has simplified and streamlined the process of research data management planning, storage, discovery and reuse through collaboration and the use of integrated and tailored online tools, and a simplification of the metadata schema. This poster presents the integrated data management services a QUT, including QUT’s Data Management Planning Tool, Research Data Finder, Spatial Data Finder and Software Finder, and information on the simplified Registry Interchange Format – Collections and Services (RIF-CS) Schema. The QUT Data Management Planning (DMP) Tool was built using the Digital Curation Centre’s DMP Online Tool and modified to QUT’s needs and policies. The tool allows researchers and Higher Degree Research students to plan how to handle research data throughout the active phase of their research. The plan is promoted as a ‘live’ document’ and researchers are encouraged to update it as required. The information entered into the plan can be made private or shared with supervisors, project members and external examiners. A plan is mandatory when requesting storage space on the QUT Research Data Storage Service. QUT’s Research Data Finder is integrated with QUT’s Academic Profiles and the Data Management Planning Tool to create a seamless data management process. This process aims to encourage the creation of high quality rich records which facilitate discovery and reuse of quality data. The Registry Interchange Format – Collections and Services (RIF-CS) Schema that is used in the QUT Research Data Finder was simplified to “RIF-CS lite” to reflect mandatory and optional metadata requirements. RIF-CS lite removed schema fields that were underused or extra to the needs of the users and system. This has reduced the amount of metadata fields required from users and made integration of systems a far more simple process where field content is easily shared across services making the process of collecting metadata as transparent as possible.

A Synthetic Model for the Inhibition of Glutathione Peroxidase by Antiarthritic Gold Compounds

In this paper, inhibition of the glutathione peroxidase activity of two synthetic organoselenium compounds, bis[2-(N,N-dimethylamino)benzyl]diselenide (5) and bis[2-(N,N-dimethylamino)benzyl]selenide (9), by gold(I) thioglucose (1), chloro(triethylphosphine)gold(I), chloro(trimethylphosphine)gold(I), and chloro(triphenylphosphine)gold(I) is described. The inhibition is found to be competitive with respect to a peroxide (H2O2) substrate and noncompetitive with respect to a thiol (PhSH) cosubstrate. The diselenide 5 reacts with PhSH to produce the corresponding selenol (6), which upon treatment with 1 equiv of gold(I) chlorides produces the corresponding gold selenolate complexes 11−13. However, the addition of 1 equiv of selenol 6 to complexes 11−13 leads to the formation of bis-selenolate complex 14 by ligand displacement reactions involving the elimination of phosphine ligands. The phosphine ligands eliminated from these reactions are further converted to the corresponding phosphine oxides (R3PO) and selenides (R3PSe). In addition to the replacement of the phosphine ligand by selenol 6, an interchange between two different phosphine ligands is also observed. For example, the reaction of complex 11 having a trimethylphosphine ligand with triphenylphosphine produces complex 13 by phosphine interchange reactions via the formation of intermediates 15 and 16. The reactivity of selenol 6 toward gold(I) phosphines is found to be similar to that of selenocysteine.

Medium-Coupled Bus-Based INS-GPS Sensor Fusion for Accurate and Reliable Positioning

A scheme for integration of stand-alone INS and GPS sensors is presented, with data interchange over an external bus. This ensures modularity and sensor interchangeability. Use of a medium-coupled scheme reduces data flow and computation, facilitating use in surface vehicles. Results show that the hybrid navigation system is capable of delivering high positioning accuracy.

Gear selectivity of large-mesh nets and drumlines used to catch sharks in the Queensland Shark Control Program.

Catches of sharks and bycatch in large-mesh nets and baited drumlines used by the Queensland Shark Control Program were examined to determine the efficacy of both gear types and assess fishing strategies that minimise their impacts. There were few significant differences in the size of both sharks and bycatch in the two gear types, apart from significantly smaller (p < 0.05) tiger sharks Galeocerdo cuvier being taken on drumlines and smaller green turtles Chelonia mydas in nets. Catch per unit effort showed orders of magnitude differences among species, even within the same family. Hammerhead sharks and rays were particularly vulnerable to net capture, whereas higher catch rates of tiger sharks were observed for drumlines. Nets caught more marine mammals, teleost fish and rays, whereas drumlines exhibited higher catch rates of the threatened loggerhead turtle Caretta caretta. Survival of most taxa (particularly obligate ram ventilators) was lower in nets than drumlines. Bycatch species (turtles and marine mammals) were able to swim to the surface to breathe when they were hooked on drumlines, enhancing their survival potential. Fishing strategies that recognise the different selectivity patterns of the gear can be developed to suit local biotic and abiotic conditions, although it is recognised that quantification of both ecological risk and risk to bathers is not a simple task.

Jump Reorientation of Water Molecules Confined in Narrow Carbon Nanotubes

We used molecular dynamics (MD) simulations to study the reorientational dynamics of water molecules confined inside narrow carbon nanotubes immersed in a bath of water. Our simulations show that the confined water molecules exhibit bistability in their reorientational relaxation, which proceeds by angular jumps between the two stable states. The angular jump of a water molecule in the bulk involves the breaking of a hydrogen bond with one of its neighbors and the formation of a hydrogen bond with a different neighbor. In contrast, the angular jump of a confined water molecule corresponds to an interchange of the two hydrogen atoms that can form a hydrogen bond with the same neighbor. The free energy barrier between these two states is a few k(B)T. The analytic solution of a simplified two-state jump model that qualitatively explains the reorientational behavior observed in simulations is also presented.

Effects of living crown reduction on needle element status of Scots pine

A wide range of biotic and abiotic factors, operating over different time perspectives and intensities, cause defoliation and a rapid decrease in the crown size of trees. Scleroderris canker disease [Gremmeniella abietina (Lagerb.) Morelet] has caused widespread crown reduction and tree mortality in Scots pine (Pinus sylvestris L) in forests in Scandinavia during the last three decades. In the 1980's, attempts were made to show, on the basis of the higher foliar N and S concentrations of affected pines in the diseased area, that sulphur and nitrogen deposition predispose trees to G. abietina. Unfortunately, in many studies on defoliated trees, exceptionally high or low needle mineral nutrient concentrations are still often interpreted as one of the causes of tree injury and not, conversely, as the result. In this thesis, three different field experiments, with foliar analysis as the main study method, were conducted in order to asses the possible long-term effects of living crown reduction on the needle nutrient concentrations of Scots pine trees in southern Finland. The crown ratio and length of the living crown were used to estimate the amount of defoliation in the reduced canopies. The material for the partial studies was collected and a total of 968 foliar samples were analysed individually (15-17 elements/sample) on a total of 488 sample trees (140 diseased, 116 pruned and 232 control trees) during the years 1987-1996 in 13 Scots pine stands. All the three experiments of this thesis provided significant evidence that severe, disease-induced defoliation or artificial pruning of the living branches can induce long-lasting nutritional changes in the foliage of the recovering trees under the typical growing conditions for Scots pine. The foliar concentrations of all the 17 mineral nutrients/elements analysed were affected, to a varying degree, by artificial pruning during the following three years. Although Scots pine, as an evergreen conifer, is considered to have low induced chemical responses to defoliation, this study proved experimentally under natural forest conditions that severe artificial pruning or disease-induced defoliation of Scots pine trees may induce biologically significant changes in the concentrations of most of the important macro- and micronutrients, as well as of carbon, in refoliated needles. Concerning the studies in this thesis, I find the results significant in providing new information about the long-term effects of rapid living crown reduction on the foliar nutrient and element status of Scots pine trees. Key words: Foliar analysis, defoliation, needle loss, pruning, nutrients, Pinus sylvestris, Gremmeniella abietina

Possible impacts of the invasive plant Rubus niveus on the native vegetation of the Scalesia Forest in the Galapagos Islands

Originally from Asia, Rubus niveus has become one of the most widespread invasive plant species in the Galapagos Islands. It has invaded open vegetation, shrubland and forest alike. It forms dense thickets up to 4 m high, appearing to displace native vegetation, and threaten the integrity of several native communities. This study used correlation analysis between a R. niveus cover gradient and a number of biotic (vascular plant species richness, cover and vegetation structure) and abiotic (light and soil properties) parameters to help understand possible impacts in one of the last remaining fragments of the Scalesia forest in Santa Cruz Island, Galapagos. Higher cover of R. niveus was associated with significantly lower native species richness and cover, and a different forest structure. Results illustrated that 60% R. niveus cover could be considered a threshold for these impacts. We suggest that a maximum of 40% R. niveus cover could be a suitable management target.

Persistence of bellyache bush (Jatropha gossypifolia L.) soil seed banks

Bellyache bush (Jatropha gossypifolia L.) is an invasive shrub that adversely impacts agricultural and natural systems of northern Australia. While several techniques are available to control bellyache bush, depletion of soil seed banks is central to its management. A 10-year study determined the persistence of intact and ant-discarded bellyache bush seeds buried in shade cloth packets at six depths (ranging from 0 to 40 cm) under both natural rainfall and rainfall-excluded conditions. A second study monitored changes in seedling emergence over time, to provide an indication of the natural rate of seed bank depletion at two sites (rocky and heavy clay) following the physical removal of all bellyache bush plants. Persistence of seed in the burial trial varied depending on seed type, rainfall conditions and burial depth. No viable seeds of bellyache bush remained after 72 months irrespective of seed type under natural rainfall conditions. When rainfall was excluded seeds persisted for much longer, with a small portion (0.4%) of ant-discarded seeds still viable after 120 months. Seed persistence was prolonged (> 96 months to decline to < 1% viability) at all burial depths under rainfall-excluded conditions. In contrast, under natural rainfall, surface located seeds took twice as long (70 months) to decline to 1% viability compared with buried seeds (35 months). No seedling emergence was observed after 58 months and 36 months at the rocky and heavy clay soil sites, respectively. These results suggest that the required duration of control programs on bellyache bush may vary due to the effect of biotic and abiotic factors on persistence of soil seed banks.

The virulence of Finnish Pyrenophora teres f. teres isolates and its implications for resistance breeding

In Finland, barley, Hordeum vulgare L., covers 50 % of the total acreage devoted to cereal cultivation. The most common disease of barley in Finland is net blotch, a foliar disease caused by the ascomycete Pyrenophora teres Drechsler. Disease resistance based on plant genes is an environmentally friendly and economical way to manage plant diseases caused by biotic stresses. Development of a disease resistance breeding programme is dependent on knowledge of the pathogen. In addition to information on the epidemiology and virulence of a pathogen, knowledge on how the pathogen evolves and the nature of the risks that might arise in the future are essential issues that need to be taken into account to achieve the final breeding aims. The main objectives of this study were to establish reliable and efficient testing methods for Pyrenophora teres f. teres virulence screening, and to understand the role of virulence of P. teres f. teres in Finland from a disease resistance breeding point of view. The virulence of P. teres was studied by testing 239 Finnish P. teres f. teres isolates collected between 1994 2007 originating from 19 locations, and 200 P. teres progeny isolates originating from artificially produced P. teres matings. According to the results of this study, screening for P. teres f. teres isolates on barley seedlings under greenhouse conditions is a feasible and cost efficient method to describe the virulence spectrum of the pathogen. Inoculum concentration and the seedling leaf used to gauge virulence had significant effects. Barley grain size, morphological traits of P. teres isolates, spore production and growth rate on agar did not affect the expression of virulence. A common barley differential set to characterize the P. teres virulence was developed and is recommended to be used globally. The virulence spectrum of Finnish P. teres f. teres isolates collected in 1994-2007 was constant both within and between the years. The results indicated differences in the pathogen s aggressiveness and in barley genotypes resistance. However, differences in virulence were rarely significant. Unlike in laboratory conditions, no indications of changes in virulence caused by the sexual reproduction have been observed in Finnish barley fields. In Finland, durable net blotch resistance has been achieved by introducing resistance from other barley varieties using traditional crossing methods, including wide crossing, and testing the breeding material at early generations at several sites under natural infection pressure. Novel resistance is available, which is recommended to minimize the risk of selection of virulent isolates and breakdown of currently deployed resistance.

A need for re-examination of the fibre diffraction data of A-DNA

A-DNA pattern, obtained using a flat plat camera, was indexed by Fuller Image on the basis of a c-face centred monoclinic cell with A = 22.24 Å, B = 40.62 Å, C = 28.15 Å and β = 97.0°. A precession photograph of A-DNA which gives an undistorted picture of the lattice, showed that the unit cell parameters as given by Fuller Image were not quite correct. The precession photograph showed a strong meridional reflection (R = 0.00 Å−1) on the 11th layer line. But the occurrence of the meridional reflection on the 11th layer line could not be explained on the basis of the cell parameters given by Fuller Image ; using those cell parameters the reflection which comes closest to the meridian on 11th layer line is at R = 0.025 Å−1. However, a simple interchange of a and b values accounted for the meridional reflection on 11th layer line. The corrected cell parameter refined against 28 strong spots are A = 40.75 Å, B = 22.07 Å, C = 28.16 Å and β = 97.5°. In the new unit cell of A-DNA, the packing arrangement of the two molecules is different from that in the old one. Nonetheless, our earlier contention is again reaffirmed that both right and left-handed A-DNA are stereochemically allowed and consistent with the observed fibre pattern.

Genetic Diversity and Adaptation of Date Palm (Phoenix dactylifera L.)

Acquiring sufficient information on the genetic variation, genetic differentiation, and the ecological and genetic relationships among individuals and populations are essential for establishing guidelines on conservation and utilization of the genetic resources of a species, and more particularly when biotic and abiotic stresses are considered. The aim of this study was to assess the extent and pattern of genetic variation in date palm (Phoenix dacttylifera L) cultivars; the genetic diversity and structure in its populations occurring over geographical ranges; the variation in economically and botanically important traits of it and the variation in its drought adaptive traits, in conservation and utilization context. In this study, the genetic diversity and relationships among selected cultivars from Sudan and Morocco were assessed using microsatellite markers. Microsatellite markers were also used to investigate the genetic diversity within and among populations collected from different geographic locations in Sudan. In a separate investigation, fruits of cultivars selected from Sudan, involved morphological and chemical characterization, and morphological and DNA polymorphism of the mother trees were also investigated. Morphological and photosynthetic adjustments to water stress were studied in the five most important date palm cultivars in Sudan, namely, Gondaila, Barakawi, Bitamoda, Khateeb and Laggai; and the mechanism enhancing photosynthetic gas exchange in date palm under water stress was also investigated. Results showed a significant (p < 0.001, t-test) differentiation between Sudan and Morocco groups of cultivars. However, the major feature of all tested cultivars was the complete lack of clustering and the absence of cultivars representing specific clones. The results indicated high genetic as well as compositional and morphological diversity among cultivars; while, compositional and morphological traits were found to be characteristic features that strongly differentiate cultivars as well as phenotypes. High genetic diversity was observed also in different populations. Slight but significant (p < 0.01, AMOVA) divergence was observed for soft and dry types; however, the genetic divergence among populations was relatively weak. The results showed a complex genetic relationships between some of the tested populations especially when isolation by distance was considered. The results of the study also revealed that date palm cultivars and phenotypes possess specific direct or interaction effects due to water availability on a range of morphological and physiological traits. Soft and dry phenotypes responded differently to different levels of water stress, while the dry phenotype was more sensitive and conservative. The results indicated that date palm has high fixation capacity to photosynthetic CO2 supply with interaction effect to water availability, which can be considered as advantageous when coping with stresses that may arise with climate change. In conclusion, although a large amount of diversity exists among date palm germplasm, the findings in this study show that the role of biological nature of the tree, isolation by distance and environmental effects on structuring date palm genome was highly influenced by human impacts. Identity of date palm cultivars as developed and manipulated by date palm growers, in the absence of scientific breeding programmes, may continue to mainly depend on tree morphology and fruit characters. The pattern of genetic differentiation may cover specific morphological and physiological traits that contribute to adaptive mechanisms in each phenotype. These traits can be considered for further studies related to drought adaptation in date palm.

Biological Control of Oilseed Rape Pests with Entomopathogenic Nematodes

Biological control techniques attract increasing attention as one of the sustainable alternatives to pesticide use in integrated pest management programs. In order to develop sustainable pest management methods for arable crops based on entomopathogenic nematodes (EPN), their efficacy and persistence needed to be investigated, and an economically feasible delivery system had to be developed. In this study, first a survey of entomopathogens was conducted, and a system approach was tested, using the oilseed Brassica (OSB) growing system (OSB, spring wheat, and red clover) as a model. The system approach aimed at determining the potential of Steinernema feltiae (Filipjev) for the control of OSB pests, developing OSB rotation schemes that support EPN persistence, and investigating the impact of the selected biotic and abiotic factors on efficacy and persistence of EPN. This study employed abductive logic (which employs constant interplay between the theory and empirical observation), quantitative methods, and a case study on OSB. Laboratory and field experiments were carried out, and two types of pathogen surveys. A horizontal survey included OSB fields across Estonia, Germany, Poland, Sweden and the UK, while a vertical survey included sampling from two sets of differently managed experimental fields during three years. A new approach was introduced for measuring occurrence, where the prevalence and relative intensity of entomopathogens, biotic agents, and unidentified insect antagonists were determined. The effect of dose, timing, and the application method on S. feltiae in the control of pests in OSB, and the potential of a controlled release delivery system (CRS) were evaluated in the field. Studies on the impact of selected biotic and abiotc factors (Brassica plant, bait insects, developmental stages of Meligethes aeneus Fab., Isaria fumosorosea Wize (Ifr), and organic and synthetic fertilizers) on the efficacy of S. feltiae were conducted in the laboratory. Persistence of S. feltiae in the OSB growing system, and the effect of dose, timing, and the application method, was assessed in the field as part of the efficacy experiments. The impact of selected biotic and abiotic factors on S. feltiae persistence was assessed in laboratory experiments. The pathogen survey showed that the occurrence of entomopathogens is low in the OSB growing system, and that a management system causing less disturbance (ICM) to the soil increases the relative intensity of insect parasitic nematodes and other insect antagonists. A longer study period is required to show any possible impact of ICM on the relative intensity of entomopathogenic fungi, or on the prevalence of entomopathogens. Two different measures of the occurrence yielded different results: the relative intensity revealed the difference between the two different crop management methods, while prevalence did not. The highest efficacy of S. feltiae was achieved by using a low dose and targeting all stages of M. aeneus. When only the larval stage was targeted, the application method and dose had no significant effect. The CRS decreased the pest abundance significantly more than the surface application method. S. feltiae persisted in the OSB fields in Finland for several months, but did not survive the winter. The strain survived for 7 months when it was applied in autumn in Germany, but its populations declined rapidly after winter. The examined biotic and abiotic factors had variable impacts on S. feltiae efficacy and persistence. The two measures, prevalence and relative intensity of entomopathogens, gave valuable information for their use in biocontrol programs. The recommended biocontrol strategy for OSB growing in Finland is inundation and seasonal inoculation of EPN. The impact of some biotic and abiotic factors on S. feltiae efficacy and persistence is significant, and can be used to improve the efficacy of EPN. The CRS is a novel alternative for EPN application, and should also be considered for use on other crops. Keywords: Biological control, inundation, inoculation, conservation, formulation, slow release method, crop rotation, Entomopathogenic nematodes, Steinernema feltiae, oilseed rape pests, Meligethes aeneus, Phyllotreta spp., occurrence, prevalence, intensity, efficacy, persistence, field, Isaria fumosorosea, biotic factors, abiotic factors, interaction, impact, insect stages, integrated crop management, standard (conventional) crop management

Microbial life and deposits in paper machine circuits

Väitöskirjani käsittele mikrobien ja erilaisten kemikaalien rooleja saostumien ja biofilmien muodostumisessa paperi- ja kartonkikoneilla. "Saostuma" tässä työssä tarkoittaa kiinteän aineen kertymää konepinnoille tai rajapinnoille konekierroissa, jotka on tarkoitettu massasulppujen, lietteiden, vesien tai ilman kuljetukseen. Saostumasta tulee "biofilmi" silloin kun sen oleellinen rakennekomponentti on mikrobisolut tai niiden tuotteet. Väitöstyöni työhypoteesina oli, että i. tietämys saostumien koostumuksesta, sekä ii. niiden rakenteesta, biologisista, fysikaalis-kemiallisista ja teknisistä ominaisuuksista ohjaavat tutkijaa löytämään ympäristöä säästäviä keinoja estää epätoivottujen saostumien muodostus tai purkaa jo muodostuneita saostumia. Selvittääkseni saostumien koostumista ja rakennetta käytin monia erilaisia analytiikan työkaluja, kuten elektronimikroskopiaa, konfokaali-laser mikroskopiaa (CLSM), energiadispersiivistä röntgenanalyysiä (EDX), pyrolyysi kaasukromatografiaa yhdistettynä massaspektrometriaan (Py-GCMS), joninvaihtokromatografiaa, kaasukromatografiaa ja mikrobiologisia analyysejä. Osallistuin aktiivisesti innovatiivisen, valon takaisinsirontaan perustuvan sensorin kehittämistyöhön, käytettäväksi biofilmin kasvun mittaukseen suoraan koneen vesikierroista ja säiliöistä. Työni osoitti, että monet paperinvalmistuksessa käytetyistä kemikaaleista reagoivat keskenään tuottaen orgaanisia tahmakerroksia konekiertojen teräspinnoille. Löysin myös kerrostumia, jotka valomikroskooppisessa tarkastelussa oli tulkittu mikrobeiksi, mutta jotka elektronimikroskopia paljasti alunasta syntyneiksi, alumiinihydroksidiksi joka saostui pH:ssa 6,8 kiertokuitua käyttävän koneen viiravesistä. Monet paperintekijät käyttävät vieläkin alunaa kiinnitysaineena vaikka prosessiolot ovat muuttuneet happamista neutraaleiksi. Sitä pidetään paperitekijän "aspiriinina", mutta väitöstutkimukseni osoitti sen riskit. Löysin myös orgaanisia saostumia, joiden alkuperä oli aineiden, kuten pihkan, saippuoituminen (kalsium saippuat) niin että muodostui tahmankasvua ylläpitävä alusta monilla paperi- ja kartonkikoneilla. Näin solumuodoiltaan Deinococcus geothermalista muistuttavia bakteereita kasvamassa lujasti teräskoepalojen pintaan kiinnittyneinä pesäkkeinä, kun koepaloja upotettiin paperikoneiden vesikiertoihin. Nämä deinokokkimaiset pesäkkeet voivat toimia jalustana, tarttumisalustana muiden mikrobien massoille, joka selittäisi miksi saostumat yleisesti sisältävät deinokokkeja pienenä, muttei koskaan pääasiallisena rakenneosana. Kun paperikoneiden käyttämien vesien (raakavedet, lämminvesi, biologisesti puhdistettu jätevesi) laatua tutkitaan, mittausmenetelmällä on suuri merkitys. Koepalan upotusmenetelmällä todettu biofilmikasvu ja viljelmenetelmällä mitattu bakteerisaastuneisuus korreloivat toisiinsa huonosti etenkin silloin kun likaantumisessa oli mukana rihmamaiseti kasvavia bakteereja. Huoli ympäristöstä on pakottanut paperi- ja kartonkikoneiden vesikiertojen sulkemiseen. Vesien kierrätys ja prosessivesien uudelleenkäyttö nostavat prosessilämpötilaa ja lisäävät koneella kiertävien kolloidisten ja liuenneiden aineiden määriä. Tutkin kiertovesien pitoisuuksia kolmessa eriasteisesti suljetussa tehtaassa, joiden päästöt olivat 0 m3, 0,5 m3 ja 4 m3 jätevettä tuotetonnia kohden, perustuen puhdistetun jäteveden uudelleen käyttöön. Nollapäästöisellä tehtaalla kiertovesiin kertyi paljon orgaanisesti sidottua hiiltä (> 10 g L-1), etenkin haihtuvina happoina (maito-, etikka-, propioni- ja voi-). Myös sulfaatteja, klorideja, natriumia ja kalsiumia kertyi paljon, > 1 g L-1 kutakin. Pääosa (>40%) kaikista bakteereista oli 16S rRNA geenisekvenssianalyysien tulosten perusteella sukua, joskin etäistä (< 96%) ainoastaan Enterococcus cecorum bakteerille. 4 m3 päästävältä tehtaalta löytyi lisäksi Bacillus thermoamylovorans ja Bacillus coagulans. Tehtaiden saostumat sisälsivät arkkeja suurina pitoisuuksina, ≥ 108 g-1, mutta tunnistukseen riittävää sekvenssisamanlaisuutta löytyi vain yhteen arkkisukuun, Methanothrix. Tutkimustulokset osoittivat että tehtaan vesikiertojen sulkeminen vähensi rajusti mikrobiston monimuotoisuutta, muttei estänyt liuenneen aineen ja kiintoaineen mineralisoitumista.

Methods to determine resistance to anthelmintics when continuing larval development occurs

The in vivo faecal egg count reduction test (FECRT) is the most commonly used test to detect anthelmintic resistance (AR) in gastrointestinal nematodes (GIN) of ruminants in pasture based systems. However, there are several variations on the method, some more appropriate than others in specific circumstances. While in some cases labour and time can be saved by just collecting post-drench faecal worm egg counts (FEC) of treatment groups with controls, or pre- and post-drench FEC of a treatment group with no controls, there are circumstances when pre- and post-drench FEC of an untreated control group as well as from the treatment groups are necessary. Computer simulation techniques were used to determine the most appropriate of several methods for calculating AR when there is continuing larval development during the testing period, as often occurs when anthelmintic treatments against genera of GIN with high biotic potential or high re-infection rates, such as Haemonchus contortus of sheep and Cooperia punctata of cattle, are less than 100% efficacious. Three field FECRT experimental designs were investigated: (I) post-drench FEC of treatment and controls groups, (II) pre- and post-drench FEC of a treatment group only and (III) pre- and post-drench FEC of treatment and control groups. To investigate the performance of methods of indicating AR for each of these designs, simulated animal FEC were generated from negative binominal distributions with subsequent sampling from the binomial distributions to account for drench effect, with varying parameters for worm burden, larval development and drench resistance. Calculations of percent reductions and confidence limits were based on those of the Standing Committee for Agriculture (SCA) guidelines. For the two field methods with pre-drench FEC, confidence limits were also determined from cumulative inverse Beta distributions of FEC, for eggs per gram (epg) and the number of eggs counted at detection levels of 50 and 25. Two rules for determining AR: (1) %reduction (%R) < 95% and lower confidence limit <90%; and (2) upper confidence limit <95%, were also assessed. For each combination of worm burden, larval development and drench resistance parameters, 1000 simulations were run to determine the number of times the theoretical percent reduction fell within the estimated confidence limits and the number of times resistance would have been declared. When continuing larval development occurs during the testing period of the FECRT, the simulations showed AR should be calculated from pre- and post-drench worm egg counts of an untreated control group as well as from the treatment group. If the widely used resistance rule 1 is used to assess resistance, rule 2 should also be applied, especially when %R is in the range 90 to 95% and resistance is suspected.

Can sustainable cotton production systems be developed for tropical northern Australia?

This article reviews research coordinated by the Australian Cotton Cooperative Research Centre (CRC) that investigated production issues for irrigated cotton at five targeted sites in tropical northern Australia, north of 21°S from Broome in Western Australia to the Burdekin in Queensland. The biotic and abiotic issues for cotton production were investigated with the aim of defining the potential limitations and, where appropriate, building a sustainable technical foundation for a future industry if it were to follow. Key lessons from the Cotton CRC research effort were: (1) limitations thought to be associated with cotton production in northern Australia can be overcome by developing a deep understanding of biotic and environmental constraints, then tailoring and validating production practices; and (2) transplanting of southern farming practices without consideration of local pest, soil and climatic factors is unlikely to succeed. Two grower guides were published which synthesised the research for new growers into a rational blueprint for sustainable cotton production in each region. In addition to crop production and environmental impact issues, the project identified the following as key elements needed to establish new cropping regions in tropical Australia: rigorous quantification of suitable land and sustainable water yields; support from governments; a long-term funding model for locally based research; the inclusion of traditional owners; and development of human capacity.