1,720,966 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Environmental adaptation in three-spined stickleback
Get PDFEnvironmental adaptation of a species driven by different agents of natural selection is a major focus of eco-evolutionary research. In this thesis, I aimed to understand the role of selection in shaping phenotypic and genotypic adaptation of a model fish, the three-spined stickleback (Gasterosteus aculeatus) in relation to different environmental factors. Firstly, I found significant associations between the pH of loch water and patterns of morphological diversity when comparing adaptive divergence on two neighbouring islands, North and South Uist. This suggests the influence of an abiotic agent on natural selection which might be responsible for the adaptive divergence of closely-related lineages. Secondly, I observed substantial variation in phenotypic and genotypic traits among hybrids of ancient marine anadromous and newly-adapted freshwater stickleback populations in a natural hybrid zone in North Uist. Phenotypic traits such as standard length of fish, total plate count and parasite abundance showedmosaic patterns, whereas body shape, all spines and pelvic structure exhibited clinal patterns across the hybrid zone due to adaptive divergence between parental populations. Genetic diversity was also observed using adaptive nuclear and mitochondrial markers of specific candidate loci (Eda, PPARA, WNT7B, NLRC5 and Cytochrome b gene) under selection. There was strong genotypic differentiation between marine and freshwater stickleback populations due to strong direct selection across the geographical range from sea to loch. The phenotype-genotype association of selected adaptive traits indicates the evolutionary consequences of adaptation, by identifying signatures of selection on genomic regions underlying phenotypic traits. Third, I found strong genetic links to parasite resistance underlying adaptation to infection, by examining parasitic abundance in stickleback in both natural and experimental environments. The genotypes of selected adaptive loci (Eda, PPARA, WNT7B and NLRC5) varied in relation to the common ectoparasite (Gyrodactylus sp.) and freshwater endoparasite (Diplostomum pseudospathecum), suggesting a role for parasite-mediated selection in the ecological adaptation of stickleback. Finally, I found both environmental and genetic influences on the relative abundance and diversity of bacterial species in the stickleback skin microbiome. In conclusion, the research presented in this thesis provides a significant insight into divergent phenotypic and genotypic adaptation driven by environmental selection to understand the mechanism of ecological speciation in nature
Environmental adaptation in three-spined stickleback
Get PDFEnvironmental adaptation of a species driven by different agents of natural selection is a major focus of eco-evolutionary research. In this thesis, I aimed to understand the role of selection in shaping phenotypic and genotypic adaptation of a model fish, the three-spined stickleback (Gasterosteus aculeatus) in relation to different environmental factors. Firstly, I found significant associations between the pH of loch water and patterns of morphological diversity when comparing adaptive divergence on two neighbouring islands, North and South Uist. This suggests the influence of an abiotic agent on natural selection which might be responsible for the adaptive divergence of closely-related lineages. Secondly, I observed substantial variation in phenotypic and genotypic traits among hybrids of ancient marine anadromous and newly-adapted freshwater stickleback populations in a natural hybrid zone in North Uist. Phenotypic traits such as standard length of fish, total plate count and parasite abundance showedmosaic patterns, whereas body shape, all spines and pelvic structure exhibited clinal patterns across the hybrid zone due to adaptive divergence between parental populations. Genetic diversity was also observed using adaptive nuclear and mitochondrial markers of specific candidate loci (Eda, PPARA, WNT7B, NLRC5 and Cytochrome b gene) under selection. There was strong genotypic differentiation between marine and freshwater stickleback populations due to strong direct selection across the geographical range from sea to loch. The phenotype-genotype association of selected adaptive traits indicates the evolutionary consequences of adaptation, by identifying signatures of selection on genomic regions underlying phenotypic traits. Third, I found strong genetic links to parasite resistance underlying adaptation to infection, by examining parasitic abundance in stickleback in both natural and experimental environments. The genotypes of selected adaptive loci (Eda, PPARA, WNT7B and NLRC5) varied in relation to the common ectoparasite (Gyrodactylus sp.) and freshwater endoparasite (Diplostomum pseudospathecum), suggesting a role for parasite-mediated selection in the ecological adaptation of stickleback. Finally, I found both environmental and genetic influences on the relative abundance and diversity of bacterial species in the stickleback skin microbiome. In conclusion, the research presented in this thesis provides a significant insight into divergent phenotypic and genotypic adaptation driven by environmental selection to understand the mechanism of ecological speciation in nature
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
A Comprehensive Study of the Australian Commercial Insectary Industry and its Implications for Augmentative Biological Control
Get PDFThe Australian commercial insectary industry produces biological control agents (predator, parasitoid and nematode BCAs) to control pests. This study is the first to address its lack of growth and develop recommendations. During 2011–2013, semi-structured interviews (27) were conducted with the insectary owners, citrus pest management researchers and citrus growers. A national survey of citrus growers was undertaken. A mixed method design was followed to collect qualitative and quantitative data to analyse thematically. The Australian insectary industry started with citrus pest management in the 1970s and since then the industry has expanded to five companies and 36 commercial biological control agents (commercial BCAs) in 2014. It has estimated gross sales below AUD$10 million for the 2010–2011 financial year and no export market. Users of commercial BCAs have larger farms, more employees and a consultant. The complexity of the adoption of commercial BCA is the main reason that deterred small farm owners. The insectary owners were cautious to keep their rearing methods and other information secret because of commercial confidentiality. The costs of establishing a new insectary, developing a new commercial BCA, logistics, biosecurity and skill shortage are major barriers. Patents, collaboration and government support are essential for the industry expansion. It can develop technical support software, use Skype (or an equivalent program) and develop insect identification and monitoring flash cards for technical support. It can use a model grower for advertisement and establish a retail office in all states. It can establish IPM shops or contact local shops and encourage them to sell IPM grown fresh produce. The IPM logo, TV and radio programs can increase consumers’ awareness. It needs to focus on organic farmers and encourage their uptake of the commercial BCAs. Pest management consultants and extension officers require some education about IPM or commercial BCAs
Habitat manipulation to enhance biological control of light brown apple moth (Epiphyas Postvittana)
Get PDFTrichogramma carverae Oatman and Pinto is mass-released for biological control of the leafroller pest, light brown apple moth, Epiphyas postvittana (Walker) in Australian vineyards. Parasitoid performance can, however, be constrained by a lack of suitable adult food and no information is available on the effect of nectar on the parasitism and longevity of T. carverae. To address this, the effect of alyssum, Lobularia maritima (L.) flowers on E. postvittana parasitism was studied in a vineyard experiment with and without releases of T. carverae. Egg parasitoid activity was assessed with E. postvittana egg 'sentinel cards' and no parasitism was recorded in plots without T. carverae releases. Where T. carverae were released, there was no significant enhancement of parasitism by the presence of L. maritima flowers. Three hypotheses were subsequently tested to account for the lack of an effect: (i) T. carverae does not benefit from L. maritima nectar, (ii) T. carverae was feeding on nectar from other flowering plants (weeds) present in the vineyard, (iii) T. carverae was feeding on sugars from ripe grapes. A growth-cabinet experiment using potted L. maritima plants with and without flowers did not support hypothesis one. No parasitism was recorded after day two for T. carverae caged without flowers whilst parasitism occured until day eight in the presence of flowers. A laboratory experiment with common vineyard weeds (Trifolium repens, Hypochoeris radicata, Echium plantagineum) as well as L. maritima did not support hypothesis one but gave partial support to hypothesis two. Survival of T. carverae was enhanced to a small but statistically significant extent in vials with intact flowers of L. maritima, white clover (T. repens) and catsear (H. radicata) but not in vials with flowering shoots of these species from which flowers and flowering buds had been removed. Paterson's curse (E. plantagineum) flowers had no effect on T. carverae survival. In a laboratory study, punctured grapes significantly enhanced T. carverae survival compared with a treatment without grapes, supporting hypothesis three. Trichogramma carverae performance in the field experiment was probably also constrained by relatively cool and wet weather. Further work on the enhancement of T. carverae efficacy by L. maritima and other carbohydrate sources is warranted. Greenhouse and field experiments were conducted to investigate whether T. carverae benefit from different groundcover plant species. Ten T. carverae adults (<24h after eclosion) were caged with different groundcover species and a control with no plant materials. Epiphyas postvittana egg sentinel cards were used to measure parasitism and longevity was recorded visually. Survival and realised parasitism of T. carverae was significantly higher in L. maritima than in Brassica juncea, Coriandrum sativum, shoots of these species from which flowers had been removed and nil control treatments. A similar experiment with Fagopyrum esculentum (with- and without-flowers) and a control treatment showed that survival was significantly higher in intact F. esculentum than in without-flower and control treatments. There was no significant treatment effect on parasitism in the early stages of that experiment, though parasitism was recorded in the presence of F. esculentum flowers for 12 days, compared with 6 days in other treatments. Higher parasitism was observed in intact Borago officinalis than in the flowerless shoot, water only and no plant material control treatments in a third experiment. There was no significant treatment effect on parasitism. Fitted exponential curves for survival data differed significantly in curvature in the first, second and third experiments but the slope was a non-significant parameter in the second and third experiments. In a second series of laboratory experiments, one male and one female T. carverae were caged with groundcover species to investigate male and female longevity and daily fecundity. Both male and female longevity in F. esculentum and L. maritima treatments were significantly higher than on shoots of these species from which flowers had been removed, and than in the control treatments. Daily fecundity was significantly greater in the intact L. maritima treatment than in all other treatments. Fitted exponential curves for daily fecundity differed significantly in position and slope but not in curvature. There was no significant treatment effect on longevity or parasitism when a male and female were caged with intact B. juncea, B. officinalis or without-flower of these species, nor in the treatment with no plant materials. No parasitism was observed in a survey of naturally occurring egg parasitoids on two sites close to Orange and Canowindra in New South Wales, illustrating the importance of mass releases of T. carverae in biological control of E. postvittana. In an experiment on the Canowindra site, parasitism was significantly higher on day one and day two after T. carverae release when with-flower treatments were compared with without-flower treatments. Parasitism was significantly higher in the F. esculentum treatment than in C. sativum, L. maritima, vegetation without-flowers and control treatments on these dates. On day five, parasitism was higher in C. sativum than in all other treatments. There was no significant increase in parasitism in a second experiment conducted on the Orange site. Coriandrum sativum, F. esculentum and L. maritima appear to be suitable adult food sources for T. carverae and offer some scope for habitat manipulation in vineyards The adults of many parasitoid species require nectar for optimal fitness but very little is known about flower recognition. Flight cage experiments showed that the adults of T. carverae benefited from L. maritima bearing white flowers to a greater extent than was the case for light pink, dark pink or purple flowered cultivars, despite all cultivars producing nectar. Survival and realised parasitism on non-white flowers were no greater than when the parasitoids were caged on L. maritima shoots from which flowers had been removed. The possibility that differences between L. maritima cultivars were due to factors other than flower colour, such as nectar quality, was excluded by dyeing white L. maritima flowers by placing the roots of the plants in 5% food dye (blue or pink) solution. Survival of T. carverae was lower on dyed L. maritima flowers than on undyed white flowers. Mixing the same dyes with honey in a third experiment conducted in the dark showed that the low level of feeding on dyed flowers was unlikely to be the result of olfactory or gustatory cues. Flower colour appears, therefore, to be a critical factor in the choice of plants used to enhance biological control, and is likely to also be a factor in the role parasitoids play in structuring invertebrate communities. Provision of nectar producing plants to increase the effectiveness of biological control is one aspect of habitat manipulation, but care needs to be taken to avoid the use of plant species that may benefit pest species. Greenhouse experiments were conducted to investigate whether the adult E. postvittana and larvae benefit from nectar producing groundcover species. Newly emerged E. postvittana adults were caged with different groundcover species and a honey-based artificial adult diet. The longevity of male and female E. postvittana when caged with shoots of borage (B. officinalis) and buckwheat (F. esculentum) bearing flowers was as long as when fed a honey-based artificial diet. This effect was not evident when caged with shoots of these plants from which flowers had been removed. Longevity was significantly lower than in the artificial diet treatment when caged with coriander (C. sativum) or alyssum (L. maritima) irrespective of whether flowers were present or not. There was no significant treatment effect on the lifetime fecundity of E. postvittana. A second experiment with mustard (B. juncea) (with- and without-flowers), water only and honey-based artificial adult diet showed no significant treatment effects on the longevity of male and female E. postvittana or on the lifetime fecundity of E. postvittana. The anomalous lack of a difference between the water and honey-based diet treatments precludes making conclusions on the value of B. juncea for E. postvittana. Two greenhouse experiments were conducted to evaluate the effects of groundcover species on the larval development of E. postvittana. In the first experiment, larval mortality was significantly higher in C. sativum, and L. maritima than in B. juncea, B. officinalis and white clover (T. repens) a known host of E. postvittana. Coriandrum sativum and L. maritima extended the larval period. In B. juncea and B. officinalis, mortality did not differ from that in T. repens. In F. esculentum, larval mortality was significantly higher than in T. repens. A short larval period was observed on B. juncea, B. officinalis and F. esculentum. Fitted exponential curves for larval mortality differed significantly in curvature between plant treatments. Similarly, successful pupation was significantly lower in C. sativum, F. esculentum and L. maritima than in T. repens. The percentage of successful pupation in B. juncea and B. officinalis did not differ from F. esculentum and T. repens. Fitted exponential curves for pupation differed significantly in curvature. A similar trend was observed in a second experiment with potted plants. The overall results suggest that C. sativum and L. maritima denied benefit to E. postvittana adults and larvae, so could be planted as vineyard groundcover with minimal risk of exacerbating this pest. Overall results suggest that T. carverae require nutrients to reach their full reproductive potential and flowers provide such nutrients. Lobularia maritima and C. sativum may be considered 'selective food plants' for T. carverae whereas F. esculentum appears to be a 'non-selective food plant'; both T. carverae and E. postvittana benefited from it. Fruits such as grapes can be used as food resources in habitat manipulation and this merits further research. This result also suggests that within species flower colour is an important factor for flower selection in habitat manipulation
Distributed Cooperative Control for Autonomous Microgrids
Get PDFUniversity of Technology Sydney. Faculty of Engineering and Information Technology.Distributed control for microgrids (MGs) is the current development due to its numerous benefits compared to traditional central control systems, such as system reliability, reducing its sensitivity to failures, and eliminating the requirement for central computing and communication structure. Although many research works have been accomplished on the design of MG control, distributed secondary control (DSC) needs more attention. There is still a lack of appropriate DSC design for islanded AC MGs which can restore the frequency and voltage along with precise power-sharing with detailed stability analysis. Another concern is the simplicity of DSC system design. Moreover, very little research addressed the DSC for distributed energy storage units (DESUs) for MGs considering state of charge (SoC) balancing along with frequency and voltage restoration with precise power-sharing.
This thesis proposes MG control that addresses frequency and voltage restoration with precise power-sharing, and optimises the control parameters by utilising intelligent controller and SoC balancing for DESUs in a single control strategy with detailed stability analysis. The significant contributions of this thesis are to: (1) design a DSC for MGs which covers all the control aspects in a single control strategy; (2) model the MGs for the proposed DSC in a systematic way and perform a detailed stability analysis; (3) verify the presented control with several case studies; (4) consider SoC balancing along with other control aspects in designing DSC for DESUs; (5) propose intelligent control methods to find the optimal control parameters for stability enhancement of MGs and verify their effectiveness with different case studies.
Firstly, a novel DSC with an incremental cost-based droop controller is proposed. The parameters of the proposed DSC are designed utilising the particle swarm optimization (PSO) method. A linearised small-signal state-space model considering DSC with stability studies of an islanded AC MG is also presented. The dynamic response of DSC initiates additional oscillatory modes, which affects the damping performance of the system. To enhance the system stability with DSC, a fuzzy logic based intelligent controller is also offered for tuning the secondary control parameters for the best functioning of the offered DSC. This research also introduces a new DSC system for DESUs in an islanded AC MG. By applying the suggested methodology, all the DESUs achieve exactly the same SoC with the power proportional to their capacity at the steady state, and hence the uneven degradation of DESUs is avoided
Evaluating training programmes: A grounded theory exploration of training evaluation as experienced by managers working in the textile industry in Bangladesh and the development of a new approach for the evaluation of training within that context
Get PDFThe aim of this research was to assess the existing models for the evaluation of training
and propose a context specific theory and model for adoption by the textile industry in
Bangladesh. The research adopted grounded theory as the methodology. That guided the
approach to literature inclusion, the in-depth interviews with a sample of 45 managerial
and training provider participants and subsequent data analysis. Consequently, the research
proposed a conceptual framework which led to the development of a new model for use in
that particular context. The substantive theory and model developed explained how
training could be evaluated effectively in a different cultural and business context from that
of all existing theories and models. The research therefore made significant theoretical,
managerial practice and methodological contributions to the subject.
The findings identified a new approach to the evaluation of training outcomes based on
two causal conditions, six contexts, one intervening condition, six processes and four
consequences/outcomes. These factors offered a different approach and way to evaluate
training compared to the existing models. For example, the consequences/outcomes of
training evaluation reflected evaluation based on the immediate outcomes, direct outcomes,
behavioural outcomes and performance outcomes of training.
The outcome from this research offered a significantly improved integration of theory and
practice for the effective evaluation of training within the context of the textile industry in
Bangladesh. Consequently, that reflected both the managerial and theoretical contributions
of the research. The proposed theory and model were unique to textile industry in
Bangladesh and provided managers and training specialists with both data on the
consequences of the training provided and guidelines on how approach the future design
and delivery of training activities.
Finally, the research identified several areas for future research into specific aspects of
training, its evaluation and the means of monitoring it. The methodology adopted was also
a contribution to existing knowledge about the use of the grounded theory methodology in
developing economies, specifically, the textile industry within Bangladesh
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