15 resultados para Yvonne Bennett
em eResearch Archive - Queensland Department of Agriculture
Resumo:
Non-parametric difference tests such as triangle and duo-trio tests traditionally are used to establish differences or similarities between products. However they only supply the researcher with partial answers and often further testing is required to establish the nature, size and direction of differences. This paper looks at the advantages of the difference from control (DFC) test (also known as degree of difference test) and discusses appropriate applications of the test. The scope and principle of the test, panel composition and analysis of results are presented with the aid of suitable examples. Two of the major uses of the DFC test are in quality control and shelf-life testing. The role DFC takes in these areas and the use of other tests to complement the testing is discussed. Controls or standards are important in both these areas and the use of standard products, mental and written standards and blind controls are highlighted. The DFC test has applications in products where the duo-trio and triangle tests cannot be used because of the normal heterogeneity of the product. While the DFC test is a simple difference test it can be structured to give the researcher more valuable data and scope to make informed decisions about their product.
Resumo:
Correlations between liveweight gains and temperament during feedlotting (Voisinet et al., 1997) may be an indication that cattle of different temperament suffer different degrees of stress. This paper describes the effect of grouping into feedlot pens, cattle of good, poor and mixed (some good and some poor) temperament on blood parameters that are indicators of stress (Bennett et al., 1989). Animal production for a consuming world : proceedings of 9th Congress of the Asian-Australasian Association of Animal Production Societies [AAAP] and 23rd Biennial Conference of the Australian Society of Animal Production [ASAP] and 17th Annual Symposium of the University of Sydney, Dairy Research Foundation, [DRF]. 2-7 July 2000, Sydney, Australia.
Resumo:
In order to develop an efficient and reliable biolistics transformation system for pineapples parameters need to be optimised for growth, survival and development of explants pre- and post transformation. We have optimised in vitro conditions for culture media for the various stages of plant and callus initiation and development, and for effective selection of putative transgenic material. Shoot multiplication and proliferation is best on medium containing MS basic nutrients and vitamins with the addition of 0.1 mg/L myo-inositol, 20 g/L sucrose, 2.5 mg/L BAP and 3 g/L Phytagel, followed by transfer to basic MS medium for further development. Callus production on leaf base explants is best on MS nutrients and vitamins, to which 10 mg/L of BAP and NAA each was added. Optimum explant age for bombardment is 17-35 week old callus, while a pre-bombardment osmoticum treatment in the medium is not required. By comparing several antibiotics as selective agent, it has been established that a two-step selection of 2 fortnightly sub-cultures on 50 μg/mL of geneticin in the culture medium, followed by monthly sub-cultures on 100 μg/mL geneticin is optimal for survival of transgenic callus. Shoot regeneration from callus cultures is optimal on medium containing MS nutrients and vitamins, 5% coconut water and 400 mg/L casein hydrolysate. Plants can be readily regenerated and multiplied from transgenic callus through organogenesis. Rooting of shoots does not require any additional plant hormones to the medium. A transformation efficiency of 1 – 3.5% can be achieved, depending on the gene construct applied.
Resumo:
Techniques for the introduction of transgenes to control blackheart by particle bombardment and Agrobacterium co-transformation have been developed for pineapple cv. Smooth Cayenne. Polyphenol oxidase (PPO) is the enzyme responsible for blackheart development in pineapple fruit following chilling injury. Sense, anti-sense and hairpin constructs were used as a means to suppress PPO expression in plants. Average transformation efficiency for biolistics was approximately 1% and for Agrobacterium was approximately 1.5%. These results were considered acceptable given the high regeneration potential of between 80-90% from callus cultures. Southern blot analysis revealed stable integration of transgenes with lower copy number found in plants transformed with Agrobacterium compared to those transformed by biolistics. Over 5000 plants from 55 transgenic lines are now undergoing field evaluation in Australia
Resumo:
The Australian endemic skate Dipturus polyommata collected from by-catch of a benthic prawn fishery off southern Queensland was examined to provide information on reproduction and diet. Morphological relationships of total length (LT) to disc width and LT to mass were estimated. Size at birth was estimated at c. 100-110 mm and size at first feeding at c. 105-110 mm LT. Size at 50% maturity (LT50 and 95% CI) was 321 (305-332) and 300 (285-306) mm LT for females and males, respectively. Size at first maturity corresponded to 87.7% of observed maximum size in females (366 mm LT) and 87.5% in males (343 mm L T). Two females, representing 18.2% of mature females sampled in the austral winter were each carrying two egg cases. Descriptions of egg cases are given. Diet described by the index of relative importance as a percentage (%IRI) was predominantly crustacean based with carid shrimps (53.64%) and penaeoid prawns (23.30%) the most significant prey groups. Teleosts (11.72%), gammarid amphipods (5.31%) and mysids (4.72%) were also important to the diet of the species, while a further six prey groups made only a minor contribution to diet (1.31%). An ontogenetic change was evident between the diets of immature and mature skates. Immature animals fed more extensively on carids and amphipods and mature animals on penaeoids, teleosts and mysids.
Resumo:
BACKGROUND: Field studies of diuron and its metabolites 3-(3,4-dichlorophenyl)-1-methylurea (DCPMU), 3,4-dichlorophenylurea (DCPU) and 3,4-dichloroaniline (DCA) were conducted in a farm soil and in stream sediments in coastal Queensland, Australia. RESULTS: During a 38 week period after a 1.6 kg ha^-1 diuron application, 70-100% of detected compounds were within 0-15 cm of the farm soil, and 3-10% reached the 30-45 cm depth. First-order t1/2 degradation averaged 49 ± 0.9 days for the 0-15, 0-30 and 0-45 cm soil depths. Farm runoff was collected in the first 13-50 min of episodes lasting 55-90 min. Average concentrations of diuron, DCPU and DCPMU in runoff were 93, 30 and 83-825 µg L^-1 respectively. Their total loading in all runoff was >0.6% of applied diuron. Diuron and DCPMU concentrations in stream sediments were between 3-22 and 4-31 µg kg^-1 soil respectively. The DCPMU/diuron sediment ratio was >1. CONCLUSION: Retention of diuron and its metabolites in farm topsoil indicated their negligible potential for groundwater contamination. Minimal amounts of diuron and DCMPU escaped in farm runoff. This may entail a significant loading into the wider environment at annual amounts of application. The concentrations and ratio of diuron and DCPMU in stream sediments indicated that they had prolonged residence times and potential for accumulation in sediments. The higher ecotoxicity of DCPMU compared with diuron and the combined presence of both compounds in stream sediments suggest that together they would have a greater impact on sensitive aquatic species than as currently apportioned by assessments that are based upon diuron alone.
Resumo:
‘SDX-1’ originated as an open-pollinated chance seeding in an old green of ‘Adalayd’ seashore paspalum (US Plant Patent 3939) surrounded by an undefined local ecotype of the same species. ‘SDX-1’ was finer textured and had a denser, more prostrate growth habit than its putative parents which are ‘Adalayd’ (maternal) and an undefined parental genotype growing among the surrounding local ecotype. ‘SDX-1’ was compared with other promising seedlings discovered similarly at the same time, and was selected on the basis of its dwarf growth habit, tolerance of low cutting height, turf density, fine-textured growth, and apparent salt tolerance under field conditions. Breeder: Stewart T Bennett, Paul H Tillman, Michael DePew, Enviro Turf LC, Terkonsha, MI, USA. PBR Certificate Number 3660, Application Number 2006/160, granted 16 December 2008.
Resumo:
Three species of Australian endemic catsharks (grey spotted catshark Asymbolus analis, orange spotted catshark A. rubiginosus and Australian sawtail shark Figaro boardmani) were collected from the trawl grounds of a highly seasonal commercial fishery off southern Queensland, Australia. Specimens were collected on the mid to outer continental shelf at depths between 78 and 168 m. This study provides the first information on the reproductive biology of these three poorly-known species. Mature female and male A. analis were observed from 455 mm total length (TL), mature female A. rubiginosus from 410 mm TL, mature male A. rubiginosus from 405 mm TL, mature female F. boardmani from 402 mm TL and mature male F. boardmani from 398 mm TL (although a lack of immature specimens precluded more accurate assessments of size at maturity). The reproductive mode of all species was confirmed as single oviparous (carrying only one egg case in each uterus at a time). Ovarian fecundity (the number of vitellogenic follicles) ranged from 7-20 in A. analis, 5-23 in A. rubiginosus and 9-13 in F. boardmani. Several indicators suggest that Asymbolus catsharks off southern Queensland are reproductively active year-round. The proportion of female A. rubiginosus carrying egg cases was highest in spring (60%), intermediate in autumn (50%) and lowest in winter (44%).
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This report provides quantitative information on the effects of turtle excluder devices (TEDs) and bycatch reduction devices (BRDs) on the catch rates of bycatch, prawns, scallops and byproduct species, such as Moreton Bay bugs and Balmain bugs, in Queensland’s major trawl fishing sectors. It also provides biological information on, and management advice for several species referred to in the Fishery Management Plan as the permitted species. Several recommendations are included for reducing bycatch in the trawl fishery and for sustaining stocks of the permitted species.
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Effective and targeted conservation action requires detailed information about species, their distribution, systematics and ecology as well as the distribution of threat processes which affect them. Knowledge of reptilian diversity remains surprisingly disparate, and innovative means of gaining rapid insight into the status of reptiles are needed in order to highlight urgent conservation cases and inform environmental policy with appropriate biodiversity information in a timely manner. We present the first ever global analysis of extinction risk in reptiles, based on a random representative sample of 1500 species (16% of all currently known species). To our knowledge, our results provide the first analysis of the global conservation status and distribution patterns of reptiles and the threats affecting them, highlighting conservation priorities and knowledge gaps which need to be addressed urgently to ensure the continued survival of the world’s reptiles. Nearly one in five reptilian species are threatened with extinction, with another one in five species classed as Data Deficient. The proportion of threatened reptile species is highest in freshwater environments, tropical regions and on oceanic islands, while data deficiency was highest in tropical areas, such as Central Africa and Southeast Asia, and among fossorial reptiles. Our results emphasise the need for research attention to be focussed on tropical areas which are experiencing the most dramatic rates of habitat loss, on fossorial reptiles for which there is a chronic lack of data, and on certain taxa such as snakes for which extinction risk may currently be underestimated due to lack of population information. Conservation actions specifically need to mitigate the effects of human-induced habitat loss and harvesting, which are the predominant threats to reptiles.
Resumo:
Field evaluation of germplasm for performance under water and heat stress is challenging. Field environments are variable and unpredictable, and genotype x environment interactions are difficult to interpret if environments are not well characterised. Numerous traits, genes and quantitative trait loci have been proposed for improving performance but few have been used in variety development. This reflects the limited capacity of commercial breeding companies to screen for these traits and the absence of validation in field environments relevant to breeding companies, and because little is known about the economic benefit of selecting one particular trait over another. The value of the proposed traits or genes is commonly not demonstrated in genetic backgrounds of value to breeding companies. To overcome this disconnection between physiological trait breeding and uptake by breeding companies, three field sites representing the main environment types encountered across the Australian wheatbelt were selected to form a set of managed environment facilities (MEFs). Each MEF manages soil moisture stress through irrigation, and the effects of heat stress through variable sowing dates. Field trials are monitored continuously for weather variables and changes in soil water and canopy temperature in selected probe genotypes, which aids in decisions guiding irrigation scheduling and sampling times. Protocols have been standardised for an essential core set of measurements so that phenotyping yield and other traits are consistent across sites and seasons. MEFs enable assessment of a large number of traits across multiple genetic backgrounds in relevant environments, determine relative trait value, and facilitate delivery of promising germplasm and high value traits into commercial breeding programs.
Resumo:
Suitable long term species-specific catch rate and biological data are seldom available for large shark species, particularly where historical commercial logbook reporting has been poor. However, shark control programs can provide suitable data from gear that consistently fishes nearshore waters all year round. We present an analysis of the distribution of 4757 . Galeocerdo cuvier caught in surface nets and on drumlines across 9 of the 10 locations of the Queensland Shark Control Program (QSCP) between 1993 and 2010. Standardised catch rates showed a significant decline (p<. 0.0001) in southern Queensland locations for both gear types, which contrasts with studies at other locations where increases in tiger shark catch per unit effort (CPUE) have been reported. Significant temporal declines in the average size of tiger sharks occurred at four of the nine locations analysed (p<. 0.05), which may be indicative of fishing reducing abundance in these areas. Given the long term nature of shark control programs along the Australian east coast, effects on local abundance should have been evident many years ago, which suggests that factors other than the effects of shark control programs have also contributed to the decline. While reductions in catch rate are consistent with a decline in tiger shark abundance, this interpretation should be made with caution, as the inter-annual CPUE varies considerably at most locations. Nevertheless, the overall downward trend, particularly in southern Queensland, indicates that current fishing pressures on the species may be unsustainable. © 2012 Elsevier B.V.
Resumo:
The Mobulidae are zooplanktivorous elasmobranchs comprising two recognized species of manta rays (Manta spp.) and nine recognized species of devil rays (Mobula spp.). They are found circumglobally in tropical, subtropical and temperate coastal waters. Although mobulids have been recorded for over 400 years, critical knowledge gaps still compromise the ability to assess the status of these species. On the basis of a review of 263 publications, a comparative synthesis of the biology and ecology of mobulids was conducted to examine their evolution, taxonomy, distribution, population trends, movements and aggregation, reproduction, growth and longevity, feeding, natural mortality and direct and indirect anthropogenic threats. There has been a marked increase in the number of published studies on mobulids since c. 1990, particularly for the genus Manta, although the genus Mobula remains poorly understood. Mobulid species have many common biological characteristics although their ecologies appear to be species-specific, and sometimes region-specific. Movement studies suggest that mobulids are highly mobile and have the potential to rapidly travel large distances. Fishing pressure is the major threat to many mobulid populations, with current levels of exploitation in target fisheries unlikely to be sustainable. Advances in the fields of population genetics, acoustic and satellite tracking, and stable-isotope and fatty-acid analyses will provide new insights into the biology and ecology of these species. Future research should focus on the uncertain taxonomy of mobulid species, the degree of overlap between their large-scale movement and human activities such as fisheries and pollution, and the need for management of inter-jurisdictional fisheries in developing nations to ensure their long-term sustainability. Closer collaboration among researchers worldwide is necessary to ensure standardized sampling and modelling methodologies to underpin global population estimates and status.
Resumo:
The tomato I-3 and I-7 genes confer resistance to Fusarium oxysporum f. sp. lycopersici (Fol) race 3 and were introgressed into the cultivated tomato, Solanum lycopersicum, from the wild relative Solanum pennellii. I-3 has been identified previously on chromosome 7 and encodes an S-receptor-like kinase, but little is known about I-7. Molecular markers have been developed for the marker-assisted breeding of I-3, but none are available for I-7. We used an RNA-seq and single nucleotide polymorphism (SNP) analysis approach to map I-7 to a small introgression of S. pennellii DNA (c. 210 kb) on chromosome 8, and identified I-7 as a gene encoding a leucine-rich repeat receptor-like protein (LRR-RLP), thereby expanding the repertoire of resistance protein classes conferring resistance to Fol. Using an eds1 mutant of tomato, we showed that I-7, like many other LRR-RLPs conferring pathogen resistance in tomato, is EDS1 (Enhanced Disease Susceptibility 1) dependent. Using transgenic tomato plants carrying only the I-7 gene for Fol resistance, we found that I-7 also confers resistance to Fol races 1 and 2. Given that Fol race 1 carries Avr1, resistance to Fol race 1 indicates that I-7-mediated resistance, unlike I-2- or I-3-mediated resistance, is not suppressed by Avr1. This suggests that Avr1 is not a general suppressor of Fol resistance in tomato, leading us to hypothesize that Avr1 may be acting against an EDS1-independent pathway for resistance activation. The identification of I-7 has allowed us to develop molecular markers for marker-assisted breeding of both genes currently known to confer Fol race 3 resistance (I-3 and I-7). Given that I-7-mediated resistance is not suppressed by Avr1, I-7 may be a useful addition to I-3 in the tomato breeder's toolbox.
Resumo:
Stakeholder engagement is important for successful management of natural resources, both to make effective decisions and to obtain support. However, in the context of coastal management, questions remain unanswered on how to effectively link decisions made at the catchment level with objectives for marine biodiversity and fisheries productivity. Moreover, there is much uncertainty on how to best elicit community input in a rigorous manner that supports management decisions. A decision support process is described that uses the adaptive management loop as its basis to elicit management objectives, priorities and management options using two case studies in the Great Barrier Reef, Australia. The approach described is then generalised for international interest. A hierarchical engagement model of local stakeholders, regional and senior managers is used. The result is a semi-quantitative generic elicitation framework that ultimately provides a prioritised list of management options in the context of clearly articulated management objectives that has widespread application for coastal communities worldwide. The case studies show that demand for local input and regional management is high, but local influences affect the relative success of both engagement processes and uptake by managers. Differences between case study outcomes highlight the importance of discussing objectives prior to suggesting management actions, and avoiding or minimising conflicts at the early stages of the process. Strong contributors to success are a) the provision of local information to the community group, and b) the early inclusion of senior managers and influencers in the group to ensure the intellectual and time investment is not compromised at the final stages of the process. The project has uncovered a conundrum in the significant gap between the way managers perceive their management actions and outcomes, and community's perception of the effectiveness (and wisdom) of these same management actions.