897 resultados para General and Applied Linguistics
Resumo:
Using polynomial regression and response surface analysis to examine the non-linearity between variables, this study demonstrates that better analytical nuances are required to investigate the relationships between constructs when the underlying theories suggest non-linearity. By utilising the Theory of Planned Behaviour (TPB), Ettlie’s adoption stages as well as employing data gathered from 162 owners of Small and Medium-sized Enterprises (SMEs), our findings reveal that subjective norms and attitude have differing influences upon behavioural intention in both the evaluation and trial stages of the adoption.
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Grazing experiments are usually used to quantify and demonstrate the biophysical impact of grazing strategies, with the Wambiana grazing experiment being one of the longest running such experiments in northern Australia. Previous economic analyses of this experiment suggest that there is a major advantage in stocking at a fixed, moderate stocking rate or in using decision rules allowing flexible stocking to match available feed supply. The present study developed and applied a modelling procedure to use data collected at the small plot, land type and paddock scales at the experimental site to simulate the property-level implications of a range of stocking rates for a breeding-finishing cattle enterprise. The greatest economic performance was achieved at a moderate stocking rate of 10.5 adult equivalents 100 ha(-1). For the same stocking rate over time, the fixed stocking strategy gave a greater economic performance than strategies that involved moderate changes to stocking rates each year in response to feed supply. Model outcomes were consistent with previous economic analyses using experimental data. Further modelling of the experimental data is warranted and similar analyses could be applied to other major grazing experiments to allow the scaling of results to greater scales.
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Background Alcohol expectancies likely play a role in people’s perceptions of alcohol-involved sexual violence. However, no appropriate measure exists to examine this link comprehensively. Objective The aim of this research was to develop an alcohol expectancy measure which captures young adults’ beliefs about alcohol’s role in sexual aggression and victimization. Method Two cross-sectional samples of young Australian adults (18–25 years) were recruited for scale development (Phase 1) and scale validation (Phase 2). In Phase 1, participants (N = 201; 38.3% males) completed an online survey with an initial pool of alcohol expectancy items stated in terms of three targets (self, men, women) to identify the scale’s factor structure and most effective items. A revised alcohol expectancy scale was then administered online to 322 young adults (39.6% males) in Phase 2. To assess the predictive, convergent, and discriminant validity of the scale, participants also completed established measures of personality, social desirability, alcohol use, general and context-specific alcohol expectancies, and impulsiveness. Results Principal axis factoring (Phase 1) and confirmatory factor analysis (Phase 2) resulted in a target-equivalent five-factor structure for the final 66-item Drinking Expectancy Sexual Vulnerabilities Questionnaire (DESV-Q). The factors were labeled: - (1) Sexual Coercion - (2) Sexual Vulnerability - (3) Confidence - (4) Self-Centeredness - (5) Negative Cognitive and Behavioral Changes The measure demonstrated effective items, high internal consistency, and satisfactory predictive, convergent, and discriminant validity. Conclusions The DESV-Q is a purpose-specific instrument that could be used in future research to elucidate people’s attributions for alcohol-involved sexual aggression and victimization.
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The concept of focus on opportunities describes how many new goals, options, and possibilities employees believe to have in their personal future at work. In this multi-sample, multi-method study, the authors investigated relationships between focus on opportunities and general and daily work engagement and the moderating role of focus on opportunities on between- and within-person relationships between job control and work engagement. Based on a social cognitive theory framework on the motivating potential of a future temporal focus, it was hypothesized that focus on opportunities is positively related to work engagement. Further, consistent with the notion of compensatory resources, it was expected that job control is not related to work engagement among employees with a high focus on opportunities, whereas job control, as an external resource of the work environment, is positively related to work engagement among employees with a low focus on opportunities. Both a cross-sectional survey study (N=174) and a daily diary study (N=64) supported the hypotheses. The study contributes to research on the job demands-resources model as it emphasizes the role of focus on opportunities as a motivational factor in the relationship between job control and work engagement.
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Background Excessive speed is a primary contributing factor to young novice road trauma, including intentional and unintentional speeds above posted limits or too fast for conditions. The objective of this research was to conduct a systematic review of recent investigations into novice drivers’ speed selection, with particular attention to applications and limitations of theory and methodology. Method Systematic searches of peer-reviewed and grey literature were conducted during September 2014. Abstract reviews identified 71 references potentially meeting selection criteria of investigations since the year 2000 into factors that influence (directly or indirectly) actual speed (i.e., behaviour or performance) of young (age <25 years) and/or novice (recently-licensed) drivers. Results Full paper reviews resulted in 30 final references: 15 focused on intentional speeding and 15 on broader speed selection investigations. Both sets identified a range of individual (e.g., beliefs, personality) and social (e.g., peer, adult) influences, were predominantly theory-driven and applied cross-sectional designs. Intentional speed investigations largely utilised self-reports while other investigations more often included actual driving (simulated or ‘real world’). The latter also identified cognitive workload and external environment influences, as well as targeted interventions. Discussion and implications Applications of theory have shifted the novice speed-related literature beyond a simplistic focus on intentional speeding as human error. The potential to develop a ‘grand theory’ of intentional speeding emerged and to fill gaps to understand broader speed selection influences. This includes need for future investigations of vehicle-related and physical environment-related influences and methodologies that move beyond cross-sectional designs and rely less on self-reports.
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It has long been recognized that mast cells occur throughout connective tissues. Histologic studies have revealed that such cells release their granules into the surrounding environment upon exposure to both immunologic and nonimmunologic stimuli. By microscopy these extracellular granules appeared to be phagocytosed by fibroblasts and by blood-borne phagocytic cells as they entered the site of mast cell degranulation. Such in vivo observations led to the suggestion that mast cells both altered connective tissue components and influenced fibroblast function through these discharged granules. Recent in vitro studies using cultured fibroblasts and isolated mast cells and mast cell granules have confirmed both these hypotheses. In addition, such studies have also documented that fibroblasts degrade ingested mast cell granules. Such studies document that a number of critical interactions may occur between mast cells and connective tissue components.
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Bringing a social interaction approach to children’s geographies to investigate how children accomplish place in everyday lives, we draw on ethnomethodological and conversation analytic approaches that recognize children’s competence to manipulate their social and digital worlds. An investigation of preschool-aged children engaged with Google Earth™ shows how they both claimed and displayed technological understandings and practices such as maneuvering the mouse and screen, and referenced place through relationships with local landmarks and familiar settings such as their school. At times, the children’s competing agendas required orientation to each other’s ideas, and shared negotiation to come to resolution. A focus on children’s use of digital technologies as they make meaning of the world around them makes possible new understandings of place within the geographies of childhood and education.
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Cotton bunchy top virus (CBTV) and the related Cotton leafroll dwarf virus (CLRDV) have caused sporadic disease outbreaks in most cotton regions of the world. Until recently, little was known about the diversity of CBTV or its natural host range. Seven natural field hosts and one experimental host of CBTV have now been identified. These include cotton, Malva parviflora (Marshmallow weed), Abutilon theophrasti (Velvetleaf), Anoda cristata (Spurred anoda), Hibiscus sabdariffa (Rosella), Sida rhombifolia (Paddy’s lucerne), Chamaesyce hirta (Asthma plant) and Gossypium australe. These are currently the only eight known hosts of CBTV. However the virus may have a wider host range than originally thought and include further non-Malvaceae species like asthma plant (family Euphorbiaceae). There are two distinct strains of CBTV in Australia, -A and -B, which have been detected in cotton from numerous locations across almost all growing regions. From 105 samples of cotton that have been positive for CBTV, 6 were infections of strain A only, 60 were strain B only and 64 were a mixed infection of strains A and B. These results indicate the symptoms of cotton bunchy top disease are closely associated with the presence of strain CBTV-B. A diagnostic assay for Cotton leafroll dwarf virus (CLRDV - cotton blue disease) is being developed and applied successfully for the detection of CLRDV samples from Brazil and Thailand. This is the first confirmation of CLRDV from SE-Asia, which may pose an increased biosecurity threat to the Australian industry.
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Tillering in sorghum can be associated with either the carbon supply–demand (S/D) balance of the plant or an intrinsic propensity to tiller (PTT). Knowledge of the genetic control of tillering could assist breeders in selecting germplasm with tillering characteristics appropriate for their target environments. The aims of this study were to identify QTL for tillering and component traits associated with the S/D balance or PTT, to develop a framework model for the genetic control of tillering in sorghum. Four mapping populations were grown in a number of experiments in south east Queensland, Australia. The QTL analysis suggested that the contribution of traits associated with either the S/D balance or PTT to the genotypic differences in tillering differed among populations. Thirty-four tillering QTL were identified across the populations, of which 15 were novel to this study. Additionally, half of the tillering QTL co-located with QTL for component traits. A comparison of tillering QTL and candidate gene locations identified numerous coincident QTL and gene locations across populations, including the identification of common non-synonymous SNPs in the parental genotypes of two mapping populations in a sorghum homologue of MAX1, a gene involved in the control of tiller bud outgrowth through the production of strigolactones. Combined with a framework for crop physiological processes that underpin genotypic differences in tillering, the co-location of QTL for tillering and component traits and candidate genes allowed the development of a framework QTL model for the genetic control of tillering in sorghum.
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Key message: QTLidentified for seedling and adult plant crown rot resistance in four partially resistant hexaploid wheat sources. PCR-based markers identified for use in marker-assisted selection. Abstract: Crown rot, caused by Fusarium pseudograminearum, is an important disease of wheat in many wheat-growing regions globally. Complete resistance to infection by F. pseudograminearum has not been observed in a wheat host, but germplasm with partial resistance to this pathogen has been identified. The partially resistant wheat hexaploid germplasm sources 2-49, Sunco, IRN497 and CPI133817 were investigated in both seedling and adult plant field trials to identify markers associated with the resistance which could be used in marker-assisted selection programs. Thirteen different quantitative trait loci (QTL) conditioning crown rot resistance were identified in the four different sources. Some QTL were only observed in seedling trials whereas others appeared to be adult plant specific. For example while the QTL on chromosomes 1AS, 1BS, and 4BS contributed by 2-49 and on 2BS contributed by Sunco were detected in both seedling and field trials, the QTL on 1DL present in 2-49 and the QTL on 3BL in IRN497 were only detected in seedling trials. Genetic correlations between field trials of the same population were strong, as were correlations between seedling trials of the same population. Low to moderate correlations were observed between seedling and field trials. Flanking markers, most of which are less than 10 cM apart, have now been identified for each of the regions associated with crown rot resistance.
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Comprehensive two-dimensional gas chromatography (GC×GC) offers enhanced separation efficiency, reliability in qualitative and quantitative analysis, capability to detect low quantities, and information on the whole sample and its components. These features are essential in the analysis of complex samples, in which the number of compounds may be large or the analytes of interest are present at trace level. This study involved the development of instrumentation, data analysis programs and methodologies for GC×GC and their application in studies on qualitative and quantitative aspects of GC×GC analysis. Environmental samples were used as model samples. Instrumental development comprised the construction of three versions of a semi-rotating cryogenic modulator in which modulation was based on two-step cryogenic trapping with continuously flowing carbon dioxide as coolant. Two-step trapping was achieved by rotating the nozzle spraying the carbon dioxide with a motor. The fastest rotation and highest modulation frequency were achieved with a permanent magnetic motor, and modulation was most accurate when the motor was controlled with a microcontroller containing a quartz crystal. Heated wire resistors were unnecessary for the desorption step when liquid carbon dioxide was used as coolant. With use of the modulators developed in this study, the narrowest peaks were 75 ms at base. Three data analysis programs were developed allowing basic, comparison and identification operations. Basic operations enabled the visualisation of two-dimensional plots and the determination of retention times, peak heights and volumes. The overlaying feature in the comparison program allowed easy comparison of 2D plots. An automated identification procedure based on mass spectra and retention parameters allowed the qualitative analysis of data obtained by GC×GC and time-of-flight mass spectrometry. In the methodological development, sample preparation (extraction and clean-up) and GC×GC methods were developed for the analysis of atmospheric aerosol and sediment samples. Dynamic sonication assisted extraction was well suited for atmospheric aerosols collected on a filter. A clean-up procedure utilising normal phase liquid chromatography with ultra violet detection worked well in the removal of aliphatic hydrocarbons from a sediment extract. GC×GC with flame ionisation detection or quadrupole mass spectrometry provided good reliability in the qualitative analysis of target analytes. However, GC×GC with time-of-flight mass spectrometry was needed in the analysis of unknowns. The automated identification procedure that was developed was efficient in the analysis of large data files, but manual search and analyst knowledge are invaluable as well. Quantitative analysis was examined in terms of calibration procedures and the effect of matrix compounds on GC×GC separation. In addition to calibration in GC×GC with summed peak areas or peak volumes, simplified area calibration based on normal GC signal can be used to quantify compounds in samples analysed by GC×GC so long as certain qualitative and quantitative prerequisites are met. In a study of the effect of matrix compounds on GC×GC separation, it was shown that quality of the separation of PAHs is not significantly disturbed by the amount of matrix and quantitativeness suffers only slightly in the presence of matrix and when the amount of target compounds is low. The benefits of GC×GC in the analysis of complex samples easily overcome some minor drawbacks of the technique. The developed instrumentation and methodologies performed well for environmental samples, but they could also be applied for other complex samples.
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We investigate the role of plant species in crops, pasture and native vegetation remnants in supporting agronomic pests and their predators. The study was conducted in three Australian States and across 290 sites sampled monthly for two years. Pastures played a key role in harbouring pest species consistent across States, while native vegetation hosted relatively more predators than other habitat types within each State. Furthermore, native plant species supported the lowest pest density and more predators than pests; in contrast, 75 of the exotic weed species surveyed hosted more pests than predators. Despite the role of pasture in harbouring pests, we found in NSW that pasture also supported the highest proportion of juvenile predators, while native vegetation remnants had the lowest. Our results indicate that non-crop habitat (native remnants or pasture) with few exotic weeds supports high predator and low pest arthropod densities, and that weeds are associated with high pest densities. By linking broad response variables such as ‘all pests’ with specific predictors such as ‘plant species’, our study will inform on-farm management actions of which weeds to control and which natives to plant or regenerate. This study shows the importance of knowing the function of habitats and plants species in supporting pests and predators in agricultural landscapes across multiple regions.
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The design and implementation of a complete gas sensor system for liquified petroleum gas (LPG) gas sensing are presented. The system consists of a SnO2 transducer, a lowcost heater, an application specific integrated circuit (ASIC) with front-end interface circuitry, and a microcontroller interface for data logging. The ASIC includes a relaxation-oscillator-based heater driver circuit that is capable of controlling the sensor operating temperature from 100degC to 425degC. The sensor readout circuit in the ASIC, which is based on the resistance to time conversion technique, has been designed to measure the gas sensor response over three orders of resistance change during its interaction with gases.
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Transgenic engineering of plants is important in both basic and applied research. However, the expression of a transgene can dwindle over time as the plant's small (s)RNA-guided silencing pathways shut it down. The silencing pathways have evolved as antiviral defence mechanisms, and viruses have co-evolved viral silencing-suppressor proteins (VSPs) to block them. Therefore, VSPs have been routinely used alongside desired transgene constructs to enhance their expression in transient assays. However, constitutive, stable expression of a VSP in a plant usually causes pronounced developmental abnormalities, as their actions interfere with endogenous microRNA-regulated processes, and has largely precluded the use of VSPs as an aid to stable transgene expression. In an attempt to avoid the deleterious effects but obtain the enhancing effect, a number of different VSPs were expressed exclusively in the seeds of Arabidopsis thaliana alongside a three-step transgenic pathway for the synthesis of arachidonic acid (AA), an ω-6 long chain polyunsaturated fatty acid. Results from independent transgenic events, maintained for four generations, showed that the VSP-AA-transformed plants were developmentally normal, apart from minor phenotypes at the cotyledon stage, and could produce 40% more AA than plants transformed with the AA transgene cassette alone. Intriguingly, a geminivirus VSP, V2, was constitutively expressed without causing developmental defects, as it acts on the siRNA amplification step that is not part of the miRNA pathway, and gave strong transgene enhancement. These results demonstrate that VSP expression can be used to protect and enhance stable transgene performance and has significant biotechnological application.
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Project evaluation is a process of measuring costs, benefits, risks and uncertainties for the purpose of decision-making by estimating and assessing impacts of the project to the community. The effects of impacts of toll roads are similar but different from the general non-tolled roads. Project evaluation methodologies are extensively studied and applied to various transport infrastructure projects. However, there is no definitive methodology to evaluate toll roads. This review discusses the impacts of toll roads then reviews the limitations of existing project evaluation methodologies when evaluating toll road impacts. The review identified gaps of knowledge of toll evaluations. First, the treatment of toll in project evaluation, particularly in Cost-Benefit Analysis requires further study to explore the appropriate methodology. Secondly, the project evaluation methodology needs to place strong emphasis on empirically based risk and uncertainty assessment. Addressing the limitations of the existing project evaluation methodologies leads to improvements of the methodology in practical level as well as fills the gap of knowledge of project evaluation for toll roads with respect to net impacts to the community.