80 resultados para Dominant plants


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This paper develops a causal model of environmental attitudes using measures of the dominant social paradigm of Western industrial societies. Four components of the DSP framework are examined with regard to environmental attitudes and perception of change using a sample of university students from Australia and New Zealand. The results indicate that one’s belief in the DSP has a negative effect on both environmental attitudes and perception of change necessary to ameliorate degradation of the environment. Thus, while public policy favors increasing awareness of and interest in the environment, policy instruments may remain ineffective in producing lasting change if the components of the DSP remain unchanged. It is argued that public policy ought to be directed at changing the DSP so that its negative effects will be minimized.

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It is well known that waste water treatment plant (WWTP) effluents are estrogenic. There has been much less consideration of the androgenic activity of WWTP effluents. To partly address the shortage of information on androgens in Australian WWTP effluents, in August 2006, and again in 2007, we collected discharges from up to 45 Victorian WWTPs (~25% of all WWTPs in Victoria), grouped by treatment process, i.e. activated sludge, extended aeration, and lagoon based treatment, and measured the total estrogenic, androgenic, retinoic acid, and aromatic hydrocarbon hydrogenase activity of the effluents using a hybrid yeast bioassay. This paper will concentrate on the androgenic activity and male hormone concentrations.

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The ferrous iron and 2-oxoglutarate (2OG) dependent oxygenases catalyse two electron oxidation reactions by coupling the oxidation of substrate to the oxidative decarboxylation of 2OG, giving succinate and carbon dioxide coproducts. The evidence available on the level of incorporation of one atom from dioxygen into succinate is inconclusive. Here, we demonstrate that five members of the 2OG oxygenase family, AlkB from Escherichia coli, anthocyanidin synthase and flavonol synthase from Arabidopsis thaliana, and prolyl hydroxylase domain enzyme 2 and factor inhibiting hypoxia-inducible factor-1 from Homo sapiens all incorporate a single oxygen atom, almost exclusively derived from dioxygen, into the succinate co-product.

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The relationship between muscle strength and bone mineral density illustrates the positive effect of mechanical loading on bone. But local and systemic factors may affect both muscle and bone tissues. This study investigated the effects of long-term tennis playing on the relationship between lean tissue mass and bone mineral content in the forearms, taking the body dimensions into account. Fifty-two tennis players (age 24.2 +/- 5.8 yrs, 16.2 +/- 6.1 yrs of practice) were recruited. Lean tissue mass (LTM), bone area, bone mineral content (BMC), and bone mineral density were measured at the forearms from a DXA whole-body scan. Grip strength was assessed with a dynamometer. A marked side-to-side difference (p < 0.0001) was found in favor of the dominant forearm in all parameters. Bone area and BMC correlated with grip strength on both sides (r = 0.81 - 0.84, p < 0.0001). The correlations were still significant after adjusting for whole-body BMC body height, or forearm length. This result reinforced the putative role of the muscles in the mechanical loading on bones. In addition, forearm BMC adjusted to LTM or grip strength was higher on the dominant side, suggesting that tennis playing exerts a direct effect on bone.

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This study aimed at demonstrating the asymmetry in volume between the dominant and nondominant upper limbs in tennis players, controlled for maturity status. Upper limb volumes on both sides were calculated in 72 tennis players and 84 control subjects, using the truncated cone method. The participants’ maturity status was determined using the predicted age at peak height velocity (PHV). The results showed significant larger side-to-side asymmetry in volume in tennis groups than
in control groups. These findings suggested that, even before PHV, specific-sport adaptations occurred in the dominant upper limb in tennis players.

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Purpose – The purpose of this paper is to consider whether art experiences can inform service-dominant logic (SDL) discourse through an exploration of the co-production and co-creation processes of art experiences.

Design/methodology/approach – Empirical knowledge gained about art experiences is analysed to identify emergent themes about co-production and co-creation. Four modes of qualitative data collection are employed: research participant diaries, photo elicitation, in depth interviews and focus groups.

Findings – Key findings are there are three stakeholders involved in the co-creation of art experiences, which all have critical and different roles; co-creation and co-production are both temporally based and evolving and there are points where they interact and intersect; and high levels of engagement in co-production enhance individuals' contribution to the co-creation of positive value and make their participation in future co-production opportunities more likely.

Research limitations/implications – The paper is exploratory and not a general population study. The methodology and sample of participants employed do not allow for the generalisation of the findings to the broader population.

Practical implications – Organisations may benefit from devising strategies to encourage greater dialogue and connection between all stakeholders involved in co-production and co-creation. The higher the level of individuals' co-production of art experiences the greater likelihood of positive value being co-created. Furthermore, the greater the possibility of individuals engaging in other co-production experiences in the future. While individuals are attracted to co-production possibilities, there are factors that are external to an experience that can act as either barriers to or facilitators of co-production, and that consequently impact on co-creation.

Originality/value –
There is little extant research that explores the applicability of art experiences to SDL. This paper is significant in that it employs empirical research methods to develop knowledge on the topic. Furthermore, this paper is innovative in that it seeks to see whether the art experiences can inform generic marketing models, rather than whether generic marketing models can inform arts marketing.

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New Zealand is one of the world’s largest producers of dairy products and has a climate with high levels of solar radiation; however, the use of solar energy in the dairy processing industry has received limited attention. An examination of historical records found that the annual peak in New Zealand milk production and processing occurs at a time when solar radiation levels are increasing markedly. An F-Chart analysis was used to simulate the performance of large-area arrays of solar collectors and to determine their suitability for heating and cooling in a dairy processing environment. For the study four types of solar collectors were analysed: glazed flat plates, evacuated tubes, evacuated tubes with CPC reflectors and a building-integrated solar collector under development at the University of Waikato (UoW). It was found that of these echnologies, both flat plate and evacuated tubes with CPC reflectors could make useful heating and cooling contributions. Furthermore, the solar fraction was determined mainly by the collector area to storage volume ratio. Finally, it was found that the UoW building-integrated solar collector could make a significant contribution to energy use in dairies and may be an attractive future technology for the industry.

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This thesis examines Greater Melbourne’s indigenous plants movement from the 1930s to the early twenty first century. It demonstrates the important scientific and educational role of the public intellectual, Professor John Turner, and of the Melbourne University Botany School which he led for thirty five years. The case study of the movement within the City of Sandringham and its successor the City of Bayside reveals how the inhabitants of an urbanised are responded to threats to the indigenous trees and wildflowers of their neighbourhood, stimulating botanists to assist them and using political means in order to achieve their conservation objectives. The thesis draws upon a range of local archives, conservation literature and private papers.

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This report investigated the lichen flora of the Mt Donna Buang Scenic Reserve in Victoria, There were several aims: to describe the lichens of the region, to produce a pictorial key enabling field identification and to determine any distribution patterns. A floristic survey covering approximately 50 square km was undertaken to determine lichen diversity of the region generally. Lichens were sampled along roads, tracks, walking trails and in sections of bush, taking into account forest type and, particularly, areas that were lichen rich. Seventy-five lichen species in 43 genera and 27 families were identified and described from the region. An unknown, species H, also was described. Of the 76 lichen species, 22 were crastose and the remainder macrolichens. The best represented families were: Cladoniaceae (8 species), Hypogymniaceae (6), Lobariaceae (7), Lecideaceae (6), Pannariaceae (6) and Parmeliaccae (6). This study described 12 species (17%) which previously were not known for Victoria and which are a first record for the state. These include: Cladonia sarmentosa (J.D. Hook & Taylor) Dodge, Graphis librata Knight, Parmelinopsis neodamaziana (Elix & Johnston) Elix & Hale, Pertusaria novaezelandiae Szatala, Placopsis pardlina f. microphylla Lamb, Porina leptalea AX. Sm., Pseudocyphellaria ardesiaca Galloway, Trapeliopsis congregant (Zahlbr.) Brako, Menegazzia myriotrema (Mull. Arg.) P. James, Bunodophoron scrobiculatum (Church. Bab,) Wedin, Parmelia testacea Stirton and Menegazzia purpurascens S. Louwhoff sp. nov.. The last eight species are new to the mainland and, apart from Menegazzia purpurascens, previously were known only from Tasmania. Five main elements of distribution were identified for the lichen flora of the Mt Donna Buang Scenic Reserve: cosmopolitan, austral/australasian, paleotropical, pantropical and western pacific. The majority of species (68%) had austral/australasian distributions, eleven (16%) were endemic to Australia and nine (13%) occurred only in Tasmania , Victoria and New Zealand. A pictorial, dichotomous key was constructed for the lichen flora of the Mt Donna Buang Scenic Reserve. Previously, keys to the lichen flora of Tasmanian rainforests were suggested as appropriate to similar areas in Victoria, however, the Victorian forests include a significant sclerophyll element The key presented is specific for the study site but is appropriate to similar regions in Victoria and has been tested in a number of these areas. The key was designed to be ‘user-friendly’ so that the experienced and inexperienced alike are able to use it. A more detailed investigation of the lichen flora of the Mt Donna Buang Scenic Reserve was carried out in order to determine distribution. A total of 50 quadrats, each 20m x 20m in size, were sampled. Within each, the dominant vegetation type was determined and individuals were identified and location noted. The cover abundance of each lichen species on each individual tree was estimated using a modified Braun-Blanquet scale. A total of 710 trees, representing 13 different species, were examined. Nothofagus cunninghamii (Hook.) Oerst, Eucalyptus regnans R Mull., Acacia dealbata Link, A. melanoxylon R. Br., Hedycarya angustifolia A. Cunn. and Atherosperma moschatum Labill. were the six most common tree species encountered at the study site. Nothofagus cunninghamii supported the greatest lichen diversity (39 species), although most species occurred on less than 10% of the trees. The majority of lichens occurring on N. cunninghamii A. melanoxylon, A. dealbata and H. angustifolia were foliose or crustose, those on Ł. regnans fruticose and foliose and those on A moschatum crustose. Bunodophoron australe was the only lichen species at the study site to occur on one host, Nothofagus cunninghamiL Many occurred on a number of different hosts, but were most common on one particular tree species. The distribution of lichens at the study site was analysed with a rnultivariate statistical package (PATN) which dealt with ‘pattern analysis’. The program ‘SSH’ in PATN which uses the Bray-Curtis ordination technique, was used to create scatterplots displaying the degree of dissimilarity between quadrats in terms of presence/absence of lichen species. The program ‘TWAY’ in PATN was used to construct a two way table to display which lichen species occurred in each vegetation type. The pattern analysis revealed that the lichens of the Mt Donna Buang Scenic Reserve were not restricted to any particular forest type, but particular lichens, or groups of lichens, tended to predominate in certain vegetation communities. This concurs with work done by others in Tasmanian forests. Quadrats which were situated in cool temperate rainforest were grouped more closely with each other than with quadrats in other vegetation types. These also supported the greatest number of lichen species. This was not surprising since N. cunninghamii the dominant tree species in cool temperate rainforest, supported the greatest lichen diversity.

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In this study, both physiological and cellular effects are elicited by natriuretic peptides (NPs), a novel type of plant hormone. It was found that rat ANP (rANP) influenced stomatal opening movement in Tradescantia sp., where a significant increase in stomatal opening was observed in the presence of 1 µM rANP. Furthermore, this effect is mediated by cGMP, a (putative) second messenger of NPs. Two inhibitors of guanylyl cyclase, LY 83583 and methylene blue, inhibited rANP-induced stomatal opening. In contrast, stomatal opening is induced in a concentration dependent manner by the cell permeant cGMP analogue 8-Br-cGMP. In addition it was found, that like in animals, the secondary structure of rANP is essential for rANP responses. Linearised rANP is biologically inactive. Since ANP elicit plant responses, an attempt was made to isolate NP analogues from plants. A protocol for partially purifying NP from plants was developed. It was found that two fractions eluted from an immunoaffinity chromatography column (0.5 M KCI eluted fraction and 0.75 M KCI eluted fraction) were biologically active. The level of cGMP in response to NPs was also tested. It is suggested that the receptor of NP is specific since only 0.75 M KCI eluted fractions increased cGMP levels in Zea mays root stele tissue. rANP did not elicit an effect on cGMP levels in this tissue and LY 83583 did not affect this response. It is therefore argued that a plant specific biologically active NP system is present in the stele and it is predicted that NPs modulate solute movement in this tissue. NPs also influence K+, Na+ and H+ fluxes in Zea mays root stele. Increase in both K+ and Na+ uptake were observed after 30 min., while H+ flux shifted immediately toward influx in the presence of both 0.5 and 0.75 KCI eluted fractions. Finally, a model is proposed for the effect of NPs on solute movement and its signalling system in plants.

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DNA repair mechanisms constitute an essential cellular response to DNA damage arising either from metabolic processes or from environmental sources such as ultraviolet radiation. Repair of these lesions may be via direct reversal, or by processes such as nucleotide excision repair (NER), a coordinated pathway in which lesions and the surrounding nucleotides are excised and replaced via DNA resynthesis. The importance of repair is illustrated by human disease states such as xeroderma pigmentosum and Cockayne's syndrome which result from defects in the NER system arising from mutations in XP- genes or XP- and CS- genes respectively Little detail is known of DNA damage repair processes in plants, despite the economic and ecological importance of these organisms. This study aimed to expand our knowledge of the process of NER in plants, largely via a polymerase chain reaction (PCR)-based approach involving amplification, cloning and characterisation of plant genomic DNA and cDNA. Homologues of the NER components XPF/RAD1 and XPD/RAD3 were isolated as both genomic and complete cDNA sequences from the model dicotyledonous plant Arabidopsis thaliana. The sequence of the 3'-untranslated region of atXPD was also determined. Comparison of genomic and cDNA sequences allowed a detailed analysis of gene structures, including details of intron/exon processing. Variable transcript processing to produce three distinct transcripts was found in the case of atXPF. In an attempt to validate the proposed homologous function of these cDNAs, assays to test complementation of resistance to ultraviolet radiation in the relevant yeast mutants were performed. Despite extensive amino acid sequence conservation, neither plant cDNA was able to restore UV-resistance. As the yeast RAD3 gene product is also involved in vivo in transcription, and so is required for viability, the atXPD cDNA was tested in a complementation assay for this function in an appropriate yeast mutant. The plant cDNA was found to substantially increase the viability of the yeast mutant. The structural and functional significance of these results is discussed comparatively with reference to yeast, human and other known homologues. Other putative NER homologues were identified in A. thaliana database sequences, including those of ERCC1/RAD10 and XPG/ERCC5/RAD2, and are now the subjects of ongoing investigations. This study also describes preliminary investigations of putative REVS and RAD30 translesion synthesis genes from A. thaliana.