The role of Zn2+ in insulin signalling and muscle atrophy
- Authors: Maier, Michelle
- Date: 2019
- Type: Text , Thesis , PhD
- Full Text:
- Description: Zn2+ is a broadly utilised ion in biology that has important catalytic, structural and regulatory roles within the cell. Zn2+ distribution in cells is maintained by zinc transporters, Zips and ZnTs, and disruptions in levels of Zn2+ have been associated with insulin resistance and muscle atrophy disorders. Zn2+ and reactive oxygen species (ROS) interact through inhibition of protein tyrosine phosphatases and ROS-mediated oxidation of the metal-binding metallothioneins (Mts) causing release of bound Zn2+, however the precise mechanisms are unclear. In the first study of this thesis addition of inhibitors of ROS-generating enzymes, superoxide dismutase 1 (SOD1) and NADPH oxidase 1 (NOX1) showed that only SOD1 inhibition increased short-term insulin-mediated Zn2+ release and increased the expression of Mt1 and 2. These results may suggest that ROS, in particular O2- accumulation through inhibition of SOD1, plays a role in insulin-mediated Zn2+ release. Inhibiting SOD1 prevents the conversion of O2- to H2O2 causing an accumulation of O2- in the cell which oxidises Mts to release Zn2+, thereby increasing Zn2+ levels within the cell. Manipulation of the expression of the zinc transporter Zip-7 has previously been shown to modulate cell signalling and glucose metabolism in C2C12 skeletal muscle cells, warranting further investigation into the role of Zn2+ within insulin signalling. Reducing Zip-7 expression when NOX1 was inhibited caused a decrease in Mt2 expression in response to insulin suggesting an interaction between insulin, Zip-7 and NOX1 activity but this requires further investigation. Skeletal muscle atrophy is a clinical symptom of insulin resistance and diabetes. Muscle atrophy is associated with increases in circulating glucocorticoid levels and accumulation of Zn2+ in muscle. This study investigates if Zn2+ homeostasis is disrupted in glucocorticoid-induced atrophy using C2C12 skeletal muscle cells treated with Dexamethasone (DEX) and iv insulin. Results demonstrate DEX-induced atrophy significantly increased the gene expression of the Mt1&2 and decreased glycogen accumulation when treated with insulin. Both confocal microscopy and flow cytometry showed significant increases in free cellular Zn2+ after DEX treatment. Notably, free Zn2+ levels observed with confocal microscopy increased after insulin treatment in control cells but decreased in DEX treated cells. Total cellular Zn2+ was increased by DEX treatment. This demonstrates that DEX causes Zn2+ accumulation in muscle cells and disrupts both Zn2+ homeostasis through blocking insulin-induced Zn2+ release, and insulin-induced glycogen synthesis. This raised the question of whether the same effects of atrophy on Zn2+ homeostasis apply to other cell systems. To investigate this, we examined adipose cells given that these too are involved in insulin resistance and muscle atrophy disorders. In this study we found similar increases in mRNA abundance of Mt1 & 2. Confocal microscopy revealed that DEX treatment caused changes in the distribution of free Zn2+ within peri-nuclear and cytosolic regions of the cell upon stimulation with insulin. Furthermore, investigation into morphometric changes using Oil Red O staining and particle analysis through Coherent Anti-Stokes Ramen Spectrophotometry (CARS) microscopy showed changes in cell and lipid droplet size consistent with reduced lipid turnover in DEX treated cells. These results highlight a potential mechanistic role for Zn2+ in the development of atrophy in 3T3-L1 adipocytes where increased free Zn2+ and its redistribution in cells may inhibit lipid metabolism downstream of insulin signalling. These findings show that insulin-induced Zn2+ release is disrupted by glucocorticoids and this is associated with insulin resistance. Restoring control of Zn2+ homeostasis, possibly through controlling oxidation or manipulating Zn2+ levels directly, may prove beneficial in metabolic disease states such as diabetes.
- Description: Doctor of Philosophy
- Authors: Maier, Michelle
- Date: 2019
- Type: Text , Thesis , PhD
- Full Text:
- Description: Zn2+ is a broadly utilised ion in biology that has important catalytic, structural and regulatory roles within the cell. Zn2+ distribution in cells is maintained by zinc transporters, Zips and ZnTs, and disruptions in levels of Zn2+ have been associated with insulin resistance and muscle atrophy disorders. Zn2+ and reactive oxygen species (ROS) interact through inhibition of protein tyrosine phosphatases and ROS-mediated oxidation of the metal-binding metallothioneins (Mts) causing release of bound Zn2+, however the precise mechanisms are unclear. In the first study of this thesis addition of inhibitors of ROS-generating enzymes, superoxide dismutase 1 (SOD1) and NADPH oxidase 1 (NOX1) showed that only SOD1 inhibition increased short-term insulin-mediated Zn2+ release and increased the expression of Mt1 and 2. These results may suggest that ROS, in particular O2- accumulation through inhibition of SOD1, plays a role in insulin-mediated Zn2+ release. Inhibiting SOD1 prevents the conversion of O2- to H2O2 causing an accumulation of O2- in the cell which oxidises Mts to release Zn2+, thereby increasing Zn2+ levels within the cell. Manipulation of the expression of the zinc transporter Zip-7 has previously been shown to modulate cell signalling and glucose metabolism in C2C12 skeletal muscle cells, warranting further investigation into the role of Zn2+ within insulin signalling. Reducing Zip-7 expression when NOX1 was inhibited caused a decrease in Mt2 expression in response to insulin suggesting an interaction between insulin, Zip-7 and NOX1 activity but this requires further investigation. Skeletal muscle atrophy is a clinical symptom of insulin resistance and diabetes. Muscle atrophy is associated with increases in circulating glucocorticoid levels and accumulation of Zn2+ in muscle. This study investigates if Zn2+ homeostasis is disrupted in glucocorticoid-induced atrophy using C2C12 skeletal muscle cells treated with Dexamethasone (DEX) and iv insulin. Results demonstrate DEX-induced atrophy significantly increased the gene expression of the Mt1&2 and decreased glycogen accumulation when treated with insulin. Both confocal microscopy and flow cytometry showed significant increases in free cellular Zn2+ after DEX treatment. Notably, free Zn2+ levels observed with confocal microscopy increased after insulin treatment in control cells but decreased in DEX treated cells. Total cellular Zn2+ was increased by DEX treatment. This demonstrates that DEX causes Zn2+ accumulation in muscle cells and disrupts both Zn2+ homeostasis through blocking insulin-induced Zn2+ release, and insulin-induced glycogen synthesis. This raised the question of whether the same effects of atrophy on Zn2+ homeostasis apply to other cell systems. To investigate this, we examined adipose cells given that these too are involved in insulin resistance and muscle atrophy disorders. In this study we found similar increases in mRNA abundance of Mt1 & 2. Confocal microscopy revealed that DEX treatment caused changes in the distribution of free Zn2+ within peri-nuclear and cytosolic regions of the cell upon stimulation with insulin. Furthermore, investigation into morphometric changes using Oil Red O staining and particle analysis through Coherent Anti-Stokes Ramen Spectrophotometry (CARS) microscopy showed changes in cell and lipid droplet size consistent with reduced lipid turnover in DEX treated cells. These results highlight a potential mechanistic role for Zn2+ in the development of atrophy in 3T3-L1 adipocytes where increased free Zn2+ and its redistribution in cells may inhibit lipid metabolism downstream of insulin signalling. These findings show that insulin-induced Zn2+ release is disrupted by glucocorticoids and this is associated with insulin resistance. Restoring control of Zn2+ homeostasis, possibly through controlling oxidation or manipulating Zn2+ levels directly, may prove beneficial in metabolic disease states such as diabetes.
- Description: Doctor of Philosophy
Noncoding genes on sex chromosomes and their function in sex determination, dosage compensation, male traits, and diseases
- Maier, Michelle, McInerney, Molly-Rose, Graves, Jennifer, Charchar, Fadi
- Authors: Maier, Michelle , McInerney, Molly-Rose , Graves, Jennifer , Charchar, Fadi
- Date: 2021
- Type: Text , Journal article , Review
- Relation: Sexual Development Vol. 15, no. 5-6 (2021), p. 432-440
- Relation: http://purl.org/au-research/grants/nhmrc/1123472
- Full Text:
- Reviewed:
- Description: The mammalian Y chromosome has evolved in many species into a specialized chromosome that contributes to sex development among other male phenotypes. This function is well studied in terms of protein-coding genes. Less is known about the noncoding genome on the Y chromosome and its contribution to both sex development and other traits. Once considered junk genetic material, noncoding RNAs are now known to contribute to the regulation of gene expression and to play an important role in refining cellular functions. The prime examples are noncoding genes on the X chromosome, which mitigate the differential dosage of genes on sex chromosomes. Here, we discuss the evolution of noncoding RNAs on the Y chromosome and the emerging evidence of how micro, long, and circular noncoding RNAs transcribed from the Y chromosome contribute to sex differentiation. We briefly touch on emerging evidence that these noncoding RNAs also contribute to some other important clinical phenotypes in humans. © 2021 S. Karger AG. All rights reserved.
- Authors: Maier, Michelle , McInerney, Molly-Rose , Graves, Jennifer , Charchar, Fadi
- Date: 2021
- Type: Text , Journal article , Review
- Relation: Sexual Development Vol. 15, no. 5-6 (2021), p. 432-440
- Relation: http://purl.org/au-research/grants/nhmrc/1123472
- Full Text:
- Reviewed:
- Description: The mammalian Y chromosome has evolved in many species into a specialized chromosome that contributes to sex development among other male phenotypes. This function is well studied in terms of protein-coding genes. Less is known about the noncoding genome on the Y chromosome and its contribution to both sex development and other traits. Once considered junk genetic material, noncoding RNAs are now known to contribute to the regulation of gene expression and to play an important role in refining cellular functions. The prime examples are noncoding genes on the X chromosome, which mitigate the differential dosage of genes on sex chromosomes. Here, we discuss the evolution of noncoding RNAs on the Y chromosome and the emerging evidence of how micro, long, and circular noncoding RNAs transcribed from the Y chromosome contribute to sex differentiation. We briefly touch on emerging evidence that these noncoding RNAs also contribute to some other important clinical phenotypes in humans. © 2021 S. Karger AG. All rights reserved.
Dexamethasone leads to Zn2+ accumulation and increased unbound Zn2+ in C2C12 muscle and 3T3-L1 adipose cells
- Maier, Michelle, Nankervis, Scott, Wallace, Morgan, Develyn, Tamekha, Myers, Mark
- Authors: Maier, Michelle , Nankervis, Scott , Wallace, Morgan , Develyn, Tamekha , Myers, Mark
- Date: 2023
- Type: Text , Journal article
- Relation: Journal of Cellular Biochemistry Vol. 124, no. 3 (2023), p. 409-420
- Full Text:
- Reviewed:
- Description: Skeletal muscle atrophy is associated with increases in circulating glucocorticoid levels and insulin resistance. Zinc accumulates in atrophic muscle, but the relationship between atrophy, insulin resistance, and Zn2+ homeostasis remains unclear. In this study, the effect of the glucocorticoid dexamethasone (DEX) on insulin and Zn2+ homeostasis was explored. Treatment of differentiated C2C12 skeletal myotubes and 3T3-L1 adipocytes with DEX significantly increased mRNA expression of the metal-binding proteins Mt1 and 2 and altered energy storage as shown by the increased size of lipid droplets in 3T3-L1 cells. In C2C12 cells the total cellular Zn2+ was higher after DEX treatment, and in both C2C12 and 3T3-L1 adipocytes, free unbound Zn2+ was increased. Insulin treatment led to a gradual increase in free Zn2+ in C2C12 cells, and no significant change in DEX-treated cells such that concentrations were similar 10 min after insulin treatment. These data demonstrate that DEX disturbs Zn2+ homeostasis in muscle and fat cells. Further study of the molecular pathways involved to identify novel therapeutic targets for treatment of skeletal muscle atrophy is warranted. © 2023 The Authors. Journal of Cellular Biochemistry published by Wiley Periodicals LLC.
- Authors: Maier, Michelle , Nankervis, Scott , Wallace, Morgan , Develyn, Tamekha , Myers, Mark
- Date: 2023
- Type: Text , Journal article
- Relation: Journal of Cellular Biochemistry Vol. 124, no. 3 (2023), p. 409-420
- Full Text:
- Reviewed:
- Description: Skeletal muscle atrophy is associated with increases in circulating glucocorticoid levels and insulin resistance. Zinc accumulates in atrophic muscle, but the relationship between atrophy, insulin resistance, and Zn2+ homeostasis remains unclear. In this study, the effect of the glucocorticoid dexamethasone (DEX) on insulin and Zn2+ homeostasis was explored. Treatment of differentiated C2C12 skeletal myotubes and 3T3-L1 adipocytes with DEX significantly increased mRNA expression of the metal-binding proteins Mt1 and 2 and altered energy storage as shown by the increased size of lipid droplets in 3T3-L1 cells. In C2C12 cells the total cellular Zn2+ was higher after DEX treatment, and in both C2C12 and 3T3-L1 adipocytes, free unbound Zn2+ was increased. Insulin treatment led to a gradual increase in free Zn2+ in C2C12 cells, and no significant change in DEX-treated cells such that concentrations were similar 10 min after insulin treatment. These data demonstrate that DEX disturbs Zn2+ homeostasis in muscle and fat cells. Further study of the molecular pathways involved to identify novel therapeutic targets for treatment of skeletal muscle atrophy is warranted. © 2023 The Authors. Journal of Cellular Biochemistry published by Wiley Periodicals LLC.
The effect of an e-health intervention designed to reduce prolonged occupational sitting on mean arterial pressure
- Mainsbridge, Casey, Cooley, Dean, Fraser, Sharon, Pedersen, Scott
- Authors: Mainsbridge, Casey , Cooley, Dean , Fraser, Sharon , Pedersen, Scott
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of Occupational and Environmental Medicine Vol. 56, no. 11 (2014), p. 1189-1194
- Full Text:
- Reviewed:
- Description: Objective: To evaluate the effect of a workplace health intervention designed to reduce prolonged occupational sitting on the mean arterial pressure (MAP) of desk-based employees. Methods: This randomized controlled trial involved an experimental group who received an e-health intervention and a control group who did not. The 13-week intervention passively prompted participants to stand and engage in short bouts of office-based physical activity by interrupting prolonged occupational sitting time periodically throughout the workday. Mean arterial pressure was measured at pretest and posttest. Results: Between pretest and posttest the experimental group significantly reduced their MAP, whereas MAP in the control group did not. Conclusions: A workplace e-health intervention designed to reduce prolonged occupational sitting was effective in decreasing MAP in desk-based employees.
- Authors: Mainsbridge, Casey , Cooley, Dean , Fraser, Sharon , Pedersen, Scott
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of Occupational and Environmental Medicine Vol. 56, no. 11 (2014), p. 1189-1194
- Full Text:
- Reviewed:
- Description: Objective: To evaluate the effect of a workplace health intervention designed to reduce prolonged occupational sitting on the mean arterial pressure (MAP) of desk-based employees. Methods: This randomized controlled trial involved an experimental group who received an e-health intervention and a control group who did not. The 13-week intervention passively prompted participants to stand and engage in short bouts of office-based physical activity by interrupting prolonged occupational sitting time periodically throughout the workday. Mean arterial pressure was measured at pretest and posttest. Results: Between pretest and posttest the experimental group significantly reduced their MAP, whereas MAP in the control group did not. Conclusions: A workplace e-health intervention designed to reduce prolonged occupational sitting was effective in decreasing MAP in desk-based employees.
Blood pressure response to interrupting workplace sitting time with non-exercise physical activity: Results of a 12-month cohort study
- Mainsbridge, Casey, Ahuja, Kiran, Williams, Andrew, Bird, Marie-Louise, Cooley, Dean, Pedersen, Scott
- Authors: Mainsbridge, Casey , Ahuja, Kiran , Williams, Andrew , Bird, Marie-Louise , Cooley, Dean , Pedersen, Scott
- Date: 2018
- Type: Journal article
- Relation: Journal of Occupational and Environmental Medicine Vol. 60, no. 9 (2018), p. 769-774
- Full Text:
- Reviewed:
- Description: OBJECTIVE:To evaluate the blood pressure (BP) effects of a yearlong e-health solution designed to interrupt prolonged occupational sitting time. METHODS:BP data of 228 desk-based employees (45.1 ± 10.5 years) were analyzed at baseline, 3, 6, 9, and 12 months. RESULTS:Systolic BP significantly reduced from baseline for the first 9 months (1.0 to 3.4 mmHg P < 0.01) while diastolic and mean arterial pressure decreased for the full 12-months (4 to 5 mmHg for diastolic pressure and 3.6 to 4.2 mmHg for MAP all P < 0.01).Participants used the e-health solution 5.5 ± 2.0 times/day in the first 3 months which reduced to 4.2 ± 2.5 times/day by the end of the study (P < 0.05). CONCLUSIONS:An e-health solution designed to increase non-exercise physical activity by interrupting sitting time in the workplace is feasible and produced long-term reductions in blood pressure.
- Authors: Mainsbridge, Casey , Ahuja, Kiran , Williams, Andrew , Bird, Marie-Louise , Cooley, Dean , Pedersen, Scott
- Date: 2018
- Type: Journal article
- Relation: Journal of Occupational and Environmental Medicine Vol. 60, no. 9 (2018), p. 769-774
- Full Text:
- Reviewed:
- Description: OBJECTIVE:To evaluate the blood pressure (BP) effects of a yearlong e-health solution designed to interrupt prolonged occupational sitting time. METHODS:BP data of 228 desk-based employees (45.1 ± 10.5 years) were analyzed at baseline, 3, 6, 9, and 12 months. RESULTS:Systolic BP significantly reduced from baseline for the first 9 months (1.0 to 3.4 mmHg P < 0.01) while diastolic and mean arterial pressure decreased for the full 12-months (4 to 5 mmHg for diastolic pressure and 3.6 to 4.2 mmHg for MAP all P < 0.01).Participants used the e-health solution 5.5 ± 2.0 times/day in the first 3 months which reduced to 4.2 ± 2.5 times/day by the end of the study (P < 0.05). CONCLUSIONS:An e-health solution designed to increase non-exercise physical activity by interrupting sitting time in the workplace is feasible and produced long-term reductions in blood pressure.
Quaternary hinterland evolution of the active Banda Arc : Surface uplift and neotectonic deformation recorded by coral terraces at Kisar, Indonesia
- Major, Jonathan, Harris, Ron, Chiang, Hong-Wei, Cox, Nicole, Shen, Chuan-Chou, Nelson, Stephen, Prasetyadi, Carolus, Rianto, Arif
- Authors: Major, Jonathan , Harris, Ron , Chiang, Hong-Wei , Cox, Nicole , Shen, Chuan-Chou , Nelson, Stephen , Prasetyadi, Carolus , Rianto, Arif
- Date: 2013
- Type: Text , Journal article
- Relation: Journal of Asian Earth Sciences Vol. 73, no. (2013), p. 149-161
- Full Text:
- Reviewed:
- Description: Coral terrace surveys and U-series ages of coral yield a surface uplift rate of ~0.5. m/ka for Kisar Island, which is an emergent island in the hinterland of the active Banda arc-continent collision. Based on this rate, Kisar first emerged from the ocean as recently as ~450. ka. These uplifted terraces are gently warped in a pattern of east-west striking folds. These folds are strike parallel to more developed thrust-related folds of similar wavelength imaged by a seismic reflection profile just offshore. This deformation shows that the emergence of Kisar is influenced by forearc closure along the south-dipping Kisar Thrust. However, the pinnacle shape of Kisar and the protrusion of its metamorphic rocks through the forearc basin sediments also suggest a component of extrusion along shear zones or active doming.Coral encrusts the island coast in many locations over 100. m above sea level. Terrace morphology and coral ages are best explained by recognizing major surfaces as mostly growth terraces and minor terraces as mostly erosional into older terraces. All reliable and referable coral U-series ages determined by MC-ICP-MS correlate with marine isotope stage (MIS) 5e (118-128. ka). The only unaltered coral samples are found below 6. m elevation; however an unaltered Tridacna (giant clam) shell in growth position at 95. m elevation yields a U-series age of 195. ±. 31. ka, which corresponds to MIS 7. This age agrees with the best-fit uplift model for the island. Loose deposits of unaltered coral fragments found at elevations between 8 and 20. m yield U-series ages of <100. years and may represent paleotsunami deposits from previously undocumented tectonic activity in the region. © 2013 Elsevier Ltd.
- Description: 2003011098
- Authors: Major, Jonathan , Harris, Ron , Chiang, Hong-Wei , Cox, Nicole , Shen, Chuan-Chou , Nelson, Stephen , Prasetyadi, Carolus , Rianto, Arif
- Date: 2013
- Type: Text , Journal article
- Relation: Journal of Asian Earth Sciences Vol. 73, no. (2013), p. 149-161
- Full Text:
- Reviewed:
- Description: Coral terrace surveys and U-series ages of coral yield a surface uplift rate of ~0.5. m/ka for Kisar Island, which is an emergent island in the hinterland of the active Banda arc-continent collision. Based on this rate, Kisar first emerged from the ocean as recently as ~450. ka. These uplifted terraces are gently warped in a pattern of east-west striking folds. These folds are strike parallel to more developed thrust-related folds of similar wavelength imaged by a seismic reflection profile just offshore. This deformation shows that the emergence of Kisar is influenced by forearc closure along the south-dipping Kisar Thrust. However, the pinnacle shape of Kisar and the protrusion of its metamorphic rocks through the forearc basin sediments also suggest a component of extrusion along shear zones or active doming.Coral encrusts the island coast in many locations over 100. m above sea level. Terrace morphology and coral ages are best explained by recognizing major surfaces as mostly growth terraces and minor terraces as mostly erosional into older terraces. All reliable and referable coral U-series ages determined by MC-ICP-MS correlate with marine isotope stage (MIS) 5e (118-128. ka). The only unaltered coral samples are found below 6. m elevation; however an unaltered Tridacna (giant clam) shell in growth position at 95. m elevation yields a U-series age of 195. ±. 31. ka, which corresponds to MIS 7. This age agrees with the best-fit uplift model for the island. Loose deposits of unaltered coral fragments found at elevations between 8 and 20. m yield U-series ages of <100. years and may represent paleotsunami deposits from previously undocumented tectonic activity in the region. © 2013 Elsevier Ltd.
- Description: 2003011098
Adaption to water shortage through the implementation of a unique pipeline system in Victoria, Australia
- Mala-Jetmarova, Helena, Barton, Andrew, Bagirov, Adil, McRae-Williams, Pamela, Caris, Rob, Jackson, Peter
- Authors: Mala-Jetmarova, Helena , Barton, Andrew , Bagirov, Adil , McRae-Williams, Pamela , Caris, Rob , Jackson, Peter
- Date: 2010
- Type: Conference paper
- Relation: Paper presented at Hydropredict' 2010, 2nd International Interdisciplinary Conference on predications for Hydrology, Ecology, and Water Resources Management
- Full Text:
- Reviewed:
- Description: Abstract Water resource development has played a crucial role in the Grampians, Wimmera and Mallee regions of Australia, with the main source of surface water located in several reservoirs in the Grampians mountain ranges. Historically, water was delivered by gravity through a vast 19 500 km earthen channel system from the reservoirs to the townships and farms. As a result of the severe and protracted drought experienced in the region over the past 13 years and the projected drying climate, there have been fundamental changes made to the management of water in order to better cope with water scarcity. The primary strategic effort to sustainably manage water resources was by removing the unsustainable transport of water via the open channels which resulted in very high losses through seepage and evaporation. This inefficient system has been replaced by a pressurised pipeline, the largest geographical water infrastructure project of its type in Australia, spreading across an area of approximately 20 000 km2. To manage the change in water balance as a result of the pipeline and drying climate, the regions water corporations and environmental agencies have designed a scheme for water allocations intended to sustain local communities, allow for regional development and improve environmental conditions. This paper describes the unique pipeline system recently completed, provides a brief summary of water sharing arrangements and introduces the research program currently underway to optimise the performance of the pipeline system.
- Authors: Mala-Jetmarova, Helena , Barton, Andrew , Bagirov, Adil , McRae-Williams, Pamela , Caris, Rob , Jackson, Peter
- Date: 2010
- Type: Conference paper
- Relation: Paper presented at Hydropredict' 2010, 2nd International Interdisciplinary Conference on predications for Hydrology, Ecology, and Water Resources Management
- Full Text:
- Reviewed:
- Description: Abstract Water resource development has played a crucial role in the Grampians, Wimmera and Mallee regions of Australia, with the main source of surface water located in several reservoirs in the Grampians mountain ranges. Historically, water was delivered by gravity through a vast 19 500 km earthen channel system from the reservoirs to the townships and farms. As a result of the severe and protracted drought experienced in the region over the past 13 years and the projected drying climate, there have been fundamental changes made to the management of water in order to better cope with water scarcity. The primary strategic effort to sustainably manage water resources was by removing the unsustainable transport of water via the open channels which resulted in very high losses through seepage and evaporation. This inefficient system has been replaced by a pressurised pipeline, the largest geographical water infrastructure project of its type in Australia, spreading across an area of approximately 20 000 km2. To manage the change in water balance as a result of the pipeline and drying climate, the regions water corporations and environmental agencies have designed a scheme for water allocations intended to sustain local communities, allow for regional development and improve environmental conditions. This paper describes the unique pipeline system recently completed, provides a brief summary of water sharing arrangements and introduces the research program currently underway to optimise the performance of the pipeline system.
Optimal operation of a multi-quality water distribution system with changing turbidity and salinity levels in source reservoirs
- Mala-Jetmarova, Helena, Barton, Andrew, Bagirov, Adil
- Authors: Mala-Jetmarova, Helena , Barton, Andrew , Bagirov, Adil
- Date: 2014
- Type: Text , Conference proceedings
- Relation: http://purl.org/au-research/grants/arc/LP0990908
- Relation: 16th International Conference on Water Distribution System Analysis, WDSA 2014; Bari, Italy; 14th-17th July 2014
- Full Text:
- Description: Impact of water quality conditions in sources on the optimal operation of a regional multiquality water distribution system is analysed. Three operational objectives are concurrently minimised, being pump energy costs, turbidity and salinity deviations at customer nodes. The optimisation problem is solved using GANetXL (NSGA-II) linked with EPANet. The example network incorporates scenarios with different water quality in sources. It was discovered that two types of tradeoffs, competing and non-competing, exist between the objectives and that the type of tradeoff is not unique between a particular pair of objectives across scenarios. The findings may be used for system operational planning.
- Authors: Mala-Jetmarova, Helena , Barton, Andrew , Bagirov, Adil
- Date: 2014
- Type: Text , Conference proceedings
- Relation: http://purl.org/au-research/grants/arc/LP0990908
- Relation: 16th International Conference on Water Distribution System Analysis, WDSA 2014; Bari, Italy; 14th-17th July 2014
- Full Text:
- Description: Impact of water quality conditions in sources on the optimal operation of a regional multiquality water distribution system is analysed. Three operational objectives are concurrently minimised, being pump energy costs, turbidity and salinity deviations at customer nodes. The optimisation problem is solved using GANetXL (NSGA-II) linked with EPANet. The example network incorporates scenarios with different water quality in sources. It was discovered that two types of tradeoffs, competing and non-competing, exist between the objectives and that the type of tradeoff is not unique between a particular pair of objectives across scenarios. The findings may be used for system operational planning.
Relationships between pumping costs and water quality in optimal operation of regional multiquality water distribution systems
- Authors: Mala-Jetmarova, Helena
- Date: 2016
- Type: Text , Thesis , PhD
- Full Text:
- Description: The operation of regional multiquality water distribution systems (WDSs) is a complex task involving multiple objectives in order to meet customer water quantity and quality requirements. These objectives, often conflicting, include scheduling of pumps to minimise pumping costs and mixing different quality waters from sources to ensure adequate quality water for customers. Evolutionary algorithms have been successfully applied to optimise operation of regional WDSs. Although a considerable reduction in pumping costs was demonstrated in past studies, other legitimate objectives, for example water quality, were not considered on an equal basis as they were included as a constraint. This single-objective approach precludes the tradeoffs between the objectives being obtained, so any insight on how to operate such a system cannot be provided should pumping costs and water quality be considered on equal basis. A multi-objective approach is applied in this thesis to optimise operation of regional multiquality WDSs considering pumping costs and water quality as legitimate objectives. Two optimisation models with increasing complexity are proposed. The first model considers two objectives, the pumping costs and a general water quality objective. The second model includes three objectives, the pumping costs and two water quality objectives for turbidity and salinity. The optimisation models are applied to three example networks from the literature using numerous scenarios and water quality data from the Wimmera Mallee Pipeline, Australia. A methodology is proposed to find the optimal solution for the multi‐objective optimisation of the WDS, which links a network simulator with a multi-objective genetic algorithm. Prior to optimisation, the performance of algorithm parameters is evaluated and their sensitivity analysed, for which a new methodology is developed. The following results were obtained. For the two-objective optimisation problem, there is a tradeoff with a competing nature between pumping costs and water quality. It means that reduction in pumping costs cannot be achieved without deterioration of water quality delivered to customers and vice versa. For the three-objective optimisation problem, interestingly, there is not a unique type of tradeoff (either competing or non-competing) between a particular pair of objectives. It is dependent on network hydraulics in combination with water quality at sources and customer water quality requirements. General principles behind the tradeoffs are formulated based on new categorisation of sources, so called consistent/inconsistent water quality (CWQ/IWQ) sources, in relation to customer water quality requirements. A practical approach for system operational strategy is developed for the purpose of long-term operational planning. It enables an operator to schedule supply from multiple sources with minimum pumping costs and customer water quality requirements being satisfied as much as possible, for all predicted water quality scenarios in the system.
- Description: Doctor of Philosophy
- Authors: Mala-Jetmarova, Helena
- Date: 2016
- Type: Text , Thesis , PhD
- Full Text:
- Description: The operation of regional multiquality water distribution systems (WDSs) is a complex task involving multiple objectives in order to meet customer water quantity and quality requirements. These objectives, often conflicting, include scheduling of pumps to minimise pumping costs and mixing different quality waters from sources to ensure adequate quality water for customers. Evolutionary algorithms have been successfully applied to optimise operation of regional WDSs. Although a considerable reduction in pumping costs was demonstrated in past studies, other legitimate objectives, for example water quality, were not considered on an equal basis as they were included as a constraint. This single-objective approach precludes the tradeoffs between the objectives being obtained, so any insight on how to operate such a system cannot be provided should pumping costs and water quality be considered on equal basis. A multi-objective approach is applied in this thesis to optimise operation of regional multiquality WDSs considering pumping costs and water quality as legitimate objectives. Two optimisation models with increasing complexity are proposed. The first model considers two objectives, the pumping costs and a general water quality objective. The second model includes three objectives, the pumping costs and two water quality objectives for turbidity and salinity. The optimisation models are applied to three example networks from the literature using numerous scenarios and water quality data from the Wimmera Mallee Pipeline, Australia. A methodology is proposed to find the optimal solution for the multi‐objective optimisation of the WDS, which links a network simulator with a multi-objective genetic algorithm. Prior to optimisation, the performance of algorithm parameters is evaluated and their sensitivity analysed, for which a new methodology is developed. The following results were obtained. For the two-objective optimisation problem, there is a tradeoff with a competing nature between pumping costs and water quality. It means that reduction in pumping costs cannot be achieved without deterioration of water quality delivered to customers and vice versa. For the three-objective optimisation problem, interestingly, there is not a unique type of tradeoff (either competing or non-competing) between a particular pair of objectives. It is dependent on network hydraulics in combination with water quality at sources and customer water quality requirements. General principles behind the tradeoffs are formulated based on new categorisation of sources, so called consistent/inconsistent water quality (CWQ/IWQ) sources, in relation to customer water quality requirements. A practical approach for system operational strategy is developed for the purpose of long-term operational planning. It enables an operator to schedule supply from multiple sources with minimum pumping costs and customer water quality requirements being satisfied as much as possible, for all predicted water quality scenarios in the system.
- Description: Doctor of Philosophy
Lost in optimisation of water distribution systems? A literature review of system operation
- Mala-Jetmarova, Helena, Sultanova, Nargiz, Savic, Dragan
- Authors: Mala-Jetmarova, Helena , Sultanova, Nargiz , Savic, Dragan
- Date: 2017
- Type: Text , Journal article , Review
- Relation: Environmental Modelling and Software Vol. 93, no. (2017), p. 209-254
- Full Text:
- Reviewed:
- Description: Optimisation of the operation of water distribution systems has been an active research field for almost half a century. It has focused mainly on optimal pump operation to minimise pumping costs and optimal water quality management to ensure that standards at customer nodes are met. This paper provides a systematic review by bringing together over two hundred publications from the past three decades, which are relevant to operational optimisation of water distribution systems, particularly optimal pump operation, valve control and system operation for water quality purposes of both urban drinking and regional multiquality water distribution systems. Uniquely, it also contains substantial and thorough information for over one hundred publications in a tabular form, which lists optimisation models inclusive of objectives, constraints, decision variables, solution methodologies used and other details. Research challenges in terms of simulation models, optimisation model formulation, selection of optimisation method and postprocessing needs have also been identified. © 2017
- Authors: Mala-Jetmarova, Helena , Sultanova, Nargiz , Savic, Dragan
- Date: 2017
- Type: Text , Journal article , Review
- Relation: Environmental Modelling and Software Vol. 93, no. (2017), p. 209-254
- Full Text:
- Reviewed:
- Description: Optimisation of the operation of water distribution systems has been an active research field for almost half a century. It has focused mainly on optimal pump operation to minimise pumping costs and optimal water quality management to ensure that standards at customer nodes are met. This paper provides a systematic review by bringing together over two hundred publications from the past three decades, which are relevant to operational optimisation of water distribution systems, particularly optimal pump operation, valve control and system operation for water quality purposes of both urban drinking and regional multiquality water distribution systems. Uniquely, it also contains substantial and thorough information for over one hundred publications in a tabular form, which lists optimisation models inclusive of objectives, constraints, decision variables, solution methodologies used and other details. Research challenges in terms of simulation models, optimisation model formulation, selection of optimisation method and postprocessing needs have also been identified. © 2017
Competing food consumption discourses and proper gendered behaviour among over 50s: are you really what you eat?
- Malatzky, Christina, Terry, Daniel, Bourke, Lisa, Glenister, Kristen, Ervin, Kaye
- Authors: Malatzky, Christina , Terry, Daniel , Bourke, Lisa , Glenister, Kristen , Ervin, Kaye
- Date: 2018
- Type: Text , Journal article
- Relation: Journal of Research for Consumers Vol. , no. 32 (2018), p. 1-31
- Full Text:
- Reviewed:
- Description: The national narratives about proper food consumption and its relationship to health and wellbeing has been articulated in many Australian public health campaigns. These shape awareness, knowledge and behaviours as well as reporting on food consumption. This paper reports on the findings of a large-scale community health survey, conducted in four Victorian regional areas, related to the self-reported eating practices of respondents aged 50 years and over. It was found that women were more likely to report trying to eat a diet consistent with public health messages than men. Overall, however there was strong agreement amongst respondents that they tried to eat a healthy diet. These findings are contextualised within broader societal discourses, including the Australian national narrative about food consumption, proper gendered behaviour, good, moral, responsible citizenship, and the competing social meanings attached to food and food consumption. It is argued that understanding the social circumstances in which people report their dietary behaviours is essential to understanding why behavioural change is such a complex goal for public health and health promotion.
- Authors: Malatzky, Christina , Terry, Daniel , Bourke, Lisa , Glenister, Kristen , Ervin, Kaye
- Date: 2018
- Type: Text , Journal article
- Relation: Journal of Research for Consumers Vol. , no. 32 (2018), p. 1-31
- Full Text:
- Reviewed:
- Description: The national narratives about proper food consumption and its relationship to health and wellbeing has been articulated in many Australian public health campaigns. These shape awareness, knowledge and behaviours as well as reporting on food consumption. This paper reports on the findings of a large-scale community health survey, conducted in four Victorian regional areas, related to the self-reported eating practices of respondents aged 50 years and over. It was found that women were more likely to report trying to eat a diet consistent with public health messages than men. Overall, however there was strong agreement amongst respondents that they tried to eat a healthy diet. These findings are contextualised within broader societal discourses, including the Australian national narrative about food consumption, proper gendered behaviour, good, moral, responsible citizenship, and the competing social meanings attached to food and food consumption. It is argued that understanding the social circumstances in which people report their dietary behaviours is essential to understanding why behavioural change is such a complex goal for public health and health promotion.
Antimicrobial sensitivity trends and virulence genes in Shigella spp. from the Oceania region
- Malau, Elisheba, Ford, Rebecca, Valcanis, Mary, Jennison, Amy, Mosse, Jenny, Bean, David, Yoannes, Mition, Pomat, William, Horwood, Paul, Greenhill, Andrew
- Authors: Malau, Elisheba , Ford, Rebecca , Valcanis, Mary , Jennison, Amy , Mosse, Jenny , Bean, David , Yoannes, Mition , Pomat, William , Horwood, Paul , Greenhill, Andrew
- Date: 2018
- Type: Text , Journal article
- Relation: Infection, Genetics and Evolution Vol. 64, no. (2018), p. 52-56
- Full Text:
- Reviewed:
- Description: Shigella is a common cause of diarrhoea in Papua New Guinea (PNG) and other Oceania countries. However, little is known about the strains causing infection. Archived Shigella isolates (n = 72) were obtained from research laboratories in PNG and reference laboratories in Australia. Shigella virulence genes were detected by PCR, and antimicrobial susceptibility was determined by disk diffusion. The ipaH virulence gene was present in all 72 isolates. The prevalence of other virulence genes was variable, with ial, invE, ipaBCD, sen/ospD3 and virF present in 60% of isolates and set1A and set1B genes present in 42% of isolates. Most S. flexneri isolates contained genes encoding enterotoxin 1 and/or enterotoxin 2. Resistance to antibiotics was common, with 51/72 isolates resistant to 2–4 antimicrobials. A greater proportion of bacteria isolated since 2010 (relative to pre-2010 isolates) were resistant to commonly used antibiotics such as ampicillin, chloramphenicol, tetracycline, and trimethoprim-sulfamethoxazole; suggesting that antimicrobial resistance (AMR) in Shigella is increasing over time in the Oceania region. There is a need for improved knowledge regarding Shigella circulation in the Oceania region and further monitoring of AMR patterns. © 2018 Elsevier B.V.
- Authors: Malau, Elisheba , Ford, Rebecca , Valcanis, Mary , Jennison, Amy , Mosse, Jenny , Bean, David , Yoannes, Mition , Pomat, William , Horwood, Paul , Greenhill, Andrew
- Date: 2018
- Type: Text , Journal article
- Relation: Infection, Genetics and Evolution Vol. 64, no. (2018), p. 52-56
- Full Text:
- Reviewed:
- Description: Shigella is a common cause of diarrhoea in Papua New Guinea (PNG) and other Oceania countries. However, little is known about the strains causing infection. Archived Shigella isolates (n = 72) were obtained from research laboratories in PNG and reference laboratories in Australia. Shigella virulence genes were detected by PCR, and antimicrobial susceptibility was determined by disk diffusion. The ipaH virulence gene was present in all 72 isolates. The prevalence of other virulence genes was variable, with ial, invE, ipaBCD, sen/ospD3 and virF present in 60% of isolates and set1A and set1B genes present in 42% of isolates. Most S. flexneri isolates contained genes encoding enterotoxin 1 and/or enterotoxin 2. Resistance to antibiotics was common, with 51/72 isolates resistant to 2–4 antimicrobials. A greater proportion of bacteria isolated since 2010 (relative to pre-2010 isolates) were resistant to commonly used antibiotics such as ampicillin, chloramphenicol, tetracycline, and trimethoprim-sulfamethoxazole; suggesting that antimicrobial resistance (AMR) in Shigella is increasing over time in the Oceania region. There is a need for improved knowledge regarding Shigella circulation in the Oceania region and further monitoring of AMR patterns. © 2018 Elsevier B.V.
The molecular characterisation of shigella spp. from Papua New Guinea and Pacific Island Nations
- Authors: Malau, Elisheba
- Date: 2019
- Type: Text , Thesis , PhD
- Full Text:
- Description: In Papua New Guinea (PNG) and other low-middle income countries (LMICs) in Oceania, diarrhoea remains a leading cause of hospitalisation and death in children <5 years old; and is an important cause of illness in older children and adults. Shigella is one of four leading causes of diarrhoea globally and is likely a major cause of diarrhoea in Oceanic LMICs, particularly PNG. A survey was conducted among parents of children with diarrhoea in the PNG highlands, demonstrating limited access to, and application of, sanitation and hygiene; likely contributing to the transmission of Shigella and other pathogens in PNG. To better understand Shigella in Oceanic LMICs, multiple analyses of isolates from within PNG (n=38), far-northeastern Australia, and from travellers returning to Australia from Oceanic LMICs with shigellosis (n=34) were conducted. Antimicrobial susceptibility (by disc diffusion), detection of virulence genes by polymerase chain reaction (PCR) were conducted on all isolates, and whole genome sequencing (WGS) conducted on 63 isolates. Shigella spp. were commonly resistant to two or more classes of first-line antibiotics, with resistance more common in post-2010 relative to pre-2010 isolates. WGS was used to verify PCR detection of virulence genes, determine whether resistance could be predicted genetically, and conduct phylogenetic analysis of Shigella spp. in Oceania. WGS surpassed PCR in the detection of virulence genes, but correlated poorly with phenotypic antimicrobial resistance. Phylogenetic analysis revealed the intra- and inter-country relatedness. Three phylogenetic groups of S. flexneri co-exist in Oceanic LMICs (and far-northeastern Australia), the result of multiple incursions. Two lineages of S. sonnei were detected, one circulating in PNG and New Caledonia, and the other in various other countries including Fiji; with no geographical overlap of the two S. sonnei lineages. Incursions of Shigella into the Oceanic LMICs occur regularly, and are likely to occur again. This study provides evidence of the need for, and potential approach to, expanded surveillance of Shigella in the region.
- Description: Doctor of Philsophy
- Authors: Malau, Elisheba
- Date: 2019
- Type: Text , Thesis , PhD
- Full Text:
- Description: In Papua New Guinea (PNG) and other low-middle income countries (LMICs) in Oceania, diarrhoea remains a leading cause of hospitalisation and death in children <5 years old; and is an important cause of illness in older children and adults. Shigella is one of four leading causes of diarrhoea globally and is likely a major cause of diarrhoea in Oceanic LMICs, particularly PNG. A survey was conducted among parents of children with diarrhoea in the PNG highlands, demonstrating limited access to, and application of, sanitation and hygiene; likely contributing to the transmission of Shigella and other pathogens in PNG. To better understand Shigella in Oceanic LMICs, multiple analyses of isolates from within PNG (n=38), far-northeastern Australia, and from travellers returning to Australia from Oceanic LMICs with shigellosis (n=34) were conducted. Antimicrobial susceptibility (by disc diffusion), detection of virulence genes by polymerase chain reaction (PCR) were conducted on all isolates, and whole genome sequencing (WGS) conducted on 63 isolates. Shigella spp. were commonly resistant to two or more classes of first-line antibiotics, with resistance more common in post-2010 relative to pre-2010 isolates. WGS was used to verify PCR detection of virulence genes, determine whether resistance could be predicted genetically, and conduct phylogenetic analysis of Shigella spp. in Oceania. WGS surpassed PCR in the detection of virulence genes, but correlated poorly with phenotypic antimicrobial resistance. Phylogenetic analysis revealed the intra- and inter-country relatedness. Three phylogenetic groups of S. flexneri co-exist in Oceanic LMICs (and far-northeastern Australia), the result of multiple incursions. Two lineages of S. sonnei were detected, one circulating in PNG and New Caledonia, and the other in various other countries including Fiji; with no geographical overlap of the two S. sonnei lineages. Incursions of Shigella into the Oceanic LMICs occur regularly, and are likely to occur again. This study provides evidence of the need for, and potential approach to, expanded surveillance of Shigella in the region.
- Description: Doctor of Philsophy
Factors affecting the organisational adoption of blockchain technology in australia : a mixed-methods approach
- Authors: Malik, Muhammad Saleem
- Date: 2022
- Type: Text , Thesis , PhD
- Full Text:
- Description: Blockchain (BCT) is an emerging technology that promises many benefits for organisations, such as disintermediation, data security, data transparency, a single version of the truth, and trust among trading partners. Despite its multiple benefits, the adoption rate of BCT among organisations has not reached a significantly high level worldwide. The present thesis addresses this issue in the Australian context. There is a knowledge gap in what specific factors, among the plethora of factors reported in the extant scholarly and commercial literature, affect Australian organisations while deciding to adopt BCT. To fill this gap, this thesis uses a mixed-methods approach known as sequential exploratory mixed methods. In this approach, the research starts with a qualitative phase as an initial phase followed by a quantitative phase. During the qualitative phase, data were collected through semi-structured interviews of the BCT experts and decision-makers working with the ifferent Australian organisations that adopted or were in the process of adopting BCT. The Technology, Organisation, Environment (TOE) framework, based on the qualitative interpretative approach, was used as a theoretical lens during the qualitative phase. The qualitative data were analyzed using the thematic analysis technique with the SQR NVivo software. The analysis shows that the different factors, belonging to the technological, organisational, and environmental contexts, affect the organisational decision to adopt BCT in Australia. The technological factors include perceived benefits, perceived computability, perceived complexity, perceived disintermediation, and perceived information transparency; organisational factors are organisational innovativeness, organisational learning capability, top management support; environmental factors consist of government support, standards uncertainty, competition intensity, and trading partners readiness. The qualitative analysis also shows the direct and moderating effect of the perceived risks between the relationship of the identified factors and organisational adoption of BCT. Based on the findings of the qualitative phase, the thesis develops a theoretical conceptual model, which shows the relationship between the factors and the organisational adoption of BCT. To increase the external validity of the developed conceptual model, the thesis started a quantitative phase with the administration of an online survey for data collection. Certain criteria were set to screen out the irrelevant participants in the survey. During this phase, hypotheses were proposed for the relationship of the factors identified in the qualitative phase and the organisational adoption of BCT. The survey data was analyzed using the PLS Structural Equation Modelling (SEM) technique with the SmartPLS 3 software. The quantitative analysis confirms the findings of the qualitative phase that the perceived benefits, perceived compatibility, perceived information transparency, perceived disintermediation, organisational innovativeness, organisational learning capability, top management support, competitive intensity, government support, and trading partner readiness have a positive effect on the organisational adoption of BCT. Whereas the perceived complexity, standards uncertainty, and perceived risks have a negative effect. The analysis also shows that the moderating effects of perceived risks are significant in the relationship of perceived compatibility, perceived information transparency, perceived disintermediation, organisational innovativeness, organisation innovativeness, competition intensity, and organisational adoption of BCT. Contrary to the qualitative findings, ‘perceived risks’ has no moderating effects on the relationship of perceived benefits, organisational learning capability, top management support, government support, trading partner readiness, and the adoption of BCT. The thesis has both theoretical and practical contributions, which are useful both for theory development and decision-making for the adoption of BCT in Australia. Theoretically, this thesis contributes to the existing IT adoption literature in several ways. Firstly, the thesis provides empirical evidence about the factors affecting organisational adoption of BCT in Australia. This is the first in-depth sequential exploratory mixed methods research that bridges this knowledge gap in the extant literature. The identification of such factors is important, particularly for the Australian government and organisations interested in the value creation of BCT. Second, the thesis reports the effect of new factors, namely, perceived information transparency, perceived disintermediation, organisational innovativeness, organisational learning capability, standards uncertainty, trading partner readiness, and competition intensity on BCT adoption that are exclusively identified in this research. Third, this thesis confirms the findings of the past studies that the factors of perceived benefits and perceived compatibility, perceived complexity, and top management support have an effect on the organisational adoption of BCT. Fourth, according to the best of the authors' knowledge, this is the first research that has used the qualitative interpretive research approach to investigate the organisational adoption of BCT. Therefore, the thesis confirms the suitability of the qualitative interpretive research approach for BCT adoption. Lastly, most of the researchers have used the TOE framework in either in qualitative or quantitative research. This thesis proves its validity in mixed methods research as well. The thesis's practical contributions are discussed in chapter 7.
- Description: Doctor of Philosophy
- Authors: Malik, Muhammad Saleem
- Date: 2022
- Type: Text , Thesis , PhD
- Full Text:
- Description: Blockchain (BCT) is an emerging technology that promises many benefits for organisations, such as disintermediation, data security, data transparency, a single version of the truth, and trust among trading partners. Despite its multiple benefits, the adoption rate of BCT among organisations has not reached a significantly high level worldwide. The present thesis addresses this issue in the Australian context. There is a knowledge gap in what specific factors, among the plethora of factors reported in the extant scholarly and commercial literature, affect Australian organisations while deciding to adopt BCT. To fill this gap, this thesis uses a mixed-methods approach known as sequential exploratory mixed methods. In this approach, the research starts with a qualitative phase as an initial phase followed by a quantitative phase. During the qualitative phase, data were collected through semi-structured interviews of the BCT experts and decision-makers working with the ifferent Australian organisations that adopted or were in the process of adopting BCT. The Technology, Organisation, Environment (TOE) framework, based on the qualitative interpretative approach, was used as a theoretical lens during the qualitative phase. The qualitative data were analyzed using the thematic analysis technique with the SQR NVivo software. The analysis shows that the different factors, belonging to the technological, organisational, and environmental contexts, affect the organisational decision to adopt BCT in Australia. The technological factors include perceived benefits, perceived computability, perceived complexity, perceived disintermediation, and perceived information transparency; organisational factors are organisational innovativeness, organisational learning capability, top management support; environmental factors consist of government support, standards uncertainty, competition intensity, and trading partners readiness. The qualitative analysis also shows the direct and moderating effect of the perceived risks between the relationship of the identified factors and organisational adoption of BCT. Based on the findings of the qualitative phase, the thesis develops a theoretical conceptual model, which shows the relationship between the factors and the organisational adoption of BCT. To increase the external validity of the developed conceptual model, the thesis started a quantitative phase with the administration of an online survey for data collection. Certain criteria were set to screen out the irrelevant participants in the survey. During this phase, hypotheses were proposed for the relationship of the factors identified in the qualitative phase and the organisational adoption of BCT. The survey data was analyzed using the PLS Structural Equation Modelling (SEM) technique with the SmartPLS 3 software. The quantitative analysis confirms the findings of the qualitative phase that the perceived benefits, perceived compatibility, perceived information transparency, perceived disintermediation, organisational innovativeness, organisational learning capability, top management support, competitive intensity, government support, and trading partner readiness have a positive effect on the organisational adoption of BCT. Whereas the perceived complexity, standards uncertainty, and perceived risks have a negative effect. The analysis also shows that the moderating effects of perceived risks are significant in the relationship of perceived compatibility, perceived information transparency, perceived disintermediation, organisational innovativeness, organisation innovativeness, competition intensity, and organisational adoption of BCT. Contrary to the qualitative findings, ‘perceived risks’ has no moderating effects on the relationship of perceived benefits, organisational learning capability, top management support, government support, trading partner readiness, and the adoption of BCT. The thesis has both theoretical and practical contributions, which are useful both for theory development and decision-making for the adoption of BCT in Australia. Theoretically, this thesis contributes to the existing IT adoption literature in several ways. Firstly, the thesis provides empirical evidence about the factors affecting organisational adoption of BCT in Australia. This is the first in-depth sequential exploratory mixed methods research that bridges this knowledge gap in the extant literature. The identification of such factors is important, particularly for the Australian government and organisations interested in the value creation of BCT. Second, the thesis reports the effect of new factors, namely, perceived information transparency, perceived disintermediation, organisational innovativeness, organisational learning capability, standards uncertainty, trading partner readiness, and competition intensity on BCT adoption that are exclusively identified in this research. Third, this thesis confirms the findings of the past studies that the factors of perceived benefits and perceived compatibility, perceived complexity, and top management support have an effect on the organisational adoption of BCT. Fourth, according to the best of the authors' knowledge, this is the first research that has used the qualitative interpretive research approach to investigate the organisational adoption of BCT. Therefore, the thesis confirms the suitability of the qualitative interpretive research approach for BCT adoption. Lastly, most of the researchers have used the TOE framework in either in qualitative or quantitative research. This thesis proves its validity in mixed methods research as well. The thesis's practical contributions are discussed in chapter 7.
- Description: Doctor of Philosophy
Factors affecting the organizational adoption of blockchain technology : extending the technology–organization– environment (TOE) framework in the Australian context
- Malik, Saleem, Chadhar, Mehmood, Vatanasakdakul, Savanid, Chetty, Madhu
- Authors: Malik, Saleem , Chadhar, Mehmood , Vatanasakdakul, Savanid , Chetty, Madhu
- Date: 2021
- Type: Text , Journal article
- Relation: Sustainability (Switzerland) Vol. 13, no. 16 (2021), p.
- Full Text:
- Reviewed:
- Description: Blockchain technology (BCT) has been gaining popularity due to its benefits for almost every industry. However, despite its benefits, the organizational adoption of BCT is rather limited. This lack of uptake motivated us to identify the factors that influence the adoption of BCT from an organizational perspective. In doing this, we reviewed the BCT literature, interviewed BCT experts, and proposed a research model based on the TOE framework. Specifically, we theorized the role of technological (perceived benefits, compatibility, information transparency, and disintermediation), organizational (organization innovativeness, organizational learning capability, and top management support), and environmental (competition intensity, government support, trading partners readiness, and standards uncertainty) factors in the organizational adoption of BCT in Australia. We confirmed the model with a sample of adopters and potential adopter organizations in Aus-tralia. The results show a significant role of the proposed factors in the organizational adoption of BCT in Australia. Additionally, we found that the relationship between the influential factors and BCT adoption is moderated by “perceived risks”. The study extends the TOE framework by adding factors that were ignored in previous studies on BCT adoption, such as perceived information trans-parency, perceived disintermediation, organizational innovativeness, organizational learning capa-bility, and standards uncertainty. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
- Authors: Malik, Saleem , Chadhar, Mehmood , Vatanasakdakul, Savanid , Chetty, Madhu
- Date: 2021
- Type: Text , Journal article
- Relation: Sustainability (Switzerland) Vol. 13, no. 16 (2021), p.
- Full Text:
- Reviewed:
- Description: Blockchain technology (BCT) has been gaining popularity due to its benefits for almost every industry. However, despite its benefits, the organizational adoption of BCT is rather limited. This lack of uptake motivated us to identify the factors that influence the adoption of BCT from an organizational perspective. In doing this, we reviewed the BCT literature, interviewed BCT experts, and proposed a research model based on the TOE framework. Specifically, we theorized the role of technological (perceived benefits, compatibility, information transparency, and disintermediation), organizational (organization innovativeness, organizational learning capability, and top management support), and environmental (competition intensity, government support, trading partners readiness, and standards uncertainty) factors in the organizational adoption of BCT in Australia. We confirmed the model with a sample of adopters and potential adopter organizations in Aus-tralia. The results show a significant role of the proposed factors in the organizational adoption of BCT in Australia. Additionally, we found that the relationship between the influential factors and BCT adoption is moderated by “perceived risks”. The study extends the TOE framework by adding factors that were ignored in previous studies on BCT adoption, such as perceived information trans-parency, perceived disintermediation, organizational innovativeness, organizational learning capa-bility, and standards uncertainty. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Factors affecting the organizational adoption of blockchain technology : an Australian perspective
- Malik, Saleem, Chadhar, Mehmood, Chetty, Madhu
- Authors: Malik, Saleem , Chadhar, Mehmood , Chetty, Madhu
- Date: 2021
- Type: Text , Conference paper
- Relation: 54th Annual Hawaii International Conference on System Sciences, HICSS 2021 Vol. 2020-January, p. 5597-5606
- Full Text:
- Reviewed:
- Description: Blockchain Technology (BCT) is a novel innovation that has the potential to transform industries, for instance, supply chain, energy, finance, and healthcare. However, despite the potential and the wide range of benefits reported, organizational adoption of BCT is low in several countries including Australia. Some studies investigated the adoption of BCT in different countries, however, there is a lack of research that examines the organizational adoption of BCT in Australia. This study fills this gap by exploring the factors, which influence BCT adoption among Australian organizations. To achieve this, we used an interpretative qualitative research approach based on the Technology, Organization, and Environment (TOE) framework and the Institutional Theory. The findings show that organizational adoption of BCT in Australia is influenced by perceived novelty, complexity, cost, and disintermediation feature of BCT; top management knowledge and support; government support, customer pressure, trading partner readiness, and consensus among trading partners. © 2021 IEEE Computer Society. All rights reserved.
- Authors: Malik, Saleem , Chadhar, Mehmood , Chetty, Madhu
- Date: 2021
- Type: Text , Conference paper
- Relation: 54th Annual Hawaii International Conference on System Sciences, HICSS 2021 Vol. 2020-January, p. 5597-5606
- Full Text:
- Reviewed:
- Description: Blockchain Technology (BCT) is a novel innovation that has the potential to transform industries, for instance, supply chain, energy, finance, and healthcare. However, despite the potential and the wide range of benefits reported, organizational adoption of BCT is low in several countries including Australia. Some studies investigated the adoption of BCT in different countries, however, there is a lack of research that examines the organizational adoption of BCT in Australia. This study fills this gap by exploring the factors, which influence BCT adoption among Australian organizations. To achieve this, we used an interpretative qualitative research approach based on the Technology, Organization, and Environment (TOE) framework and the Institutional Theory. The findings show that organizational adoption of BCT in Australia is influenced by perceived novelty, complexity, cost, and disintermediation feature of BCT; top management knowledge and support; government support, customer pressure, trading partner readiness, and consensus among trading partners. © 2021 IEEE Computer Society. All rights reserved.
Adoption of blockchain technology : exploring the factors affecting organizational decision
- Malik, Saleem, Chadhar, Mehmood, Chetty, Madhu, Vatanasakdakul, Savanid
- Authors: Malik, Saleem , Chadhar, Mehmood , Chetty, Madhu , Vatanasakdakul, Savanid
- Date: 2022
- Type: Text , Journal article , Review
- Relation: Human Behavior and Emerging Technologies Vol. 2022, no. (2022), p.
- Full Text:
- Reviewed:
- Description: Blockchain (BCT) is an emerging technology that promises many benefits for organizations, for instance, disintermediation, data security, data transparency, a single version of the truth, and trust among trading partners. Despite its multiple benefits, the adoption rate of BCT among organizations has not reached a significantly high level worldwide, thus requiring further research in this space. The present study addresses this issue in the Australian context. There is a knowledge gap in what specific factors, among the plethora of factors reported in the extant literature, affect the organizational adoption of BCT in Australia. To fill this gap, the study uses the qualitative interpretative research approach along with the technology-organization-environment (TOE) framework as a theoretical lens. The data was mainly drawn from the literature review and semi-structured interviews of the decision-makers and senior IT people from the BCT adopter and potential adopter organizations in Australia. According to the findings, perceived information transparency, perceived risks, organization innovativeness, organization learning capability, standards uncertainty, and competition intensity influence organizational adoption of BCT in Australia. These factors are exclusively identified in this study. The study also validates the influence of perceived benefits and perceived compatibility on BCT adoption that are reported in the past studies. Practically, these findings are helpful for the Australian government and public and private organizations to develop better policies and make informed decisions for the organizational adoption of BCT. The findings would guide decision-makers to think about the adoption of BCT strategically. The study also has theoretical implications explained in the discussion section. © 2022 Saleem Malik et al.
- Authors: Malik, Saleem , Chadhar, Mehmood , Chetty, Madhu , Vatanasakdakul, Savanid
- Date: 2022
- Type: Text , Journal article , Review
- Relation: Human Behavior and Emerging Technologies Vol. 2022, no. (2022), p.
- Full Text:
- Reviewed:
- Description: Blockchain (BCT) is an emerging technology that promises many benefits for organizations, for instance, disintermediation, data security, data transparency, a single version of the truth, and trust among trading partners. Despite its multiple benefits, the adoption rate of BCT among organizations has not reached a significantly high level worldwide, thus requiring further research in this space. The present study addresses this issue in the Australian context. There is a knowledge gap in what specific factors, among the plethora of factors reported in the extant literature, affect the organizational adoption of BCT in Australia. To fill this gap, the study uses the qualitative interpretative research approach along with the technology-organization-environment (TOE) framework as a theoretical lens. The data was mainly drawn from the literature review and semi-structured interviews of the decision-makers and senior IT people from the BCT adopter and potential adopter organizations in Australia. According to the findings, perceived information transparency, perceived risks, organization innovativeness, organization learning capability, standards uncertainty, and competition intensity influence organizational adoption of BCT in Australia. These factors are exclusively identified in this study. The study also validates the influence of perceived benefits and perceived compatibility on BCT adoption that are reported in the past studies. Practically, these findings are helpful for the Australian government and public and private organizations to develop better policies and make informed decisions for the organizational adoption of BCT. The findings would guide decision-makers to think about the adoption of BCT strategically. The study also has theoretical implications explained in the discussion section. © 2022 Saleem Malik et al.
Information technology and organizational learning interplay : A survey
- Malik, Saleem, Chetty, Madhu, Chadhar, Mehmood
- Authors: Malik, Saleem , Chetty, Madhu , Chadhar, Mehmood
- Date: 2018
- Type: Text , Conference proceedings
- Relation: 29th Australasian Conference on Information Systems (ACIS 2018); Sydney, Australia; 3rd December 2018 p. 1-11
- Full Text:
- Reviewed:
- Description: The objective of this paper is to provide a systematic review of the evolutionary trends in the research domain of information technology and organizational learning. Having surveyed various journals and key conferences between 2000 and 2018 on the topic, we observe that information technology (IT) has expanded from its general form to various contemporary information systems, e.g. knowledge organization systems, communication and collaborative systems and decision support systems. However, organization learning (OL) now essentially occurs through knowledge management activities, e.g. knowledge acquisition, storing, sharing and application of knowledge. The survey reported here not only validates the interplay of IT and OL but also reveals some important intervening factors between IT and OL, e.g. absorptive capacity, organization culture, user trust, acceptance and satisfaction that work as deterministic elements in the reciprocal relationship of IT and OL. We propose future research to explore interaction between big data analytical systems and organizational learning.
- Authors: Malik, Saleem , Chetty, Madhu , Chadhar, Mehmood
- Date: 2018
- Type: Text , Conference proceedings
- Relation: 29th Australasian Conference on Information Systems (ACIS 2018); Sydney, Australia; 3rd December 2018 p. 1-11
- Full Text:
- Reviewed:
- Description: The objective of this paper is to provide a systematic review of the evolutionary trends in the research domain of information technology and organizational learning. Having surveyed various journals and key conferences between 2000 and 2018 on the topic, we observe that information technology (IT) has expanded from its general form to various contemporary information systems, e.g. knowledge organization systems, communication and collaborative systems and decision support systems. However, organization learning (OL) now essentially occurs through knowledge management activities, e.g. knowledge acquisition, storing, sharing and application of knowledge. The survey reported here not only validates the interplay of IT and OL but also reveals some important intervening factors between IT and OL, e.g. absorptive capacity, organization culture, user trust, acceptance and satisfaction that work as deterministic elements in the reciprocal relationship of IT and OL. We propose future research to explore interaction between big data analytical systems and organizational learning.
An exploratory study of the adoption of blockchain technology among Australian organizations : a theoretical model
- Malik, Saleem, Chadhar, Mehmood, Chetty, Madhu, Vatanasakdakul, Savanid
- Authors: Malik, Saleem , Chadhar, Mehmood , Chetty, Madhu , Vatanasakdakul, Savanid
- Date: 2020
- Type: Text , Conference paper
- Relation: 17th European, Mediterranean, and Middle Eastern Conference on Information Systems, EMCIS 2020; Dubai; 25-26 November 2020 Vol. 402, p. 205-220
- Full Text:
- Reviewed:
- Description: Scholarly and commercial literature indicates several applications of Blockchain Technology (BCT) in different industries e.g. health, finance, supply chain, government, and energy. Despite abundant benefits reported and growing prominence, BCT has been facing various challenges across the globe, including low adoption by organizations. There is a dearth of studies that examined the organizational adoption of blockchain technology, particularly in Australia. This lack of uptake provides the rationale to initiate this research to identify the factors influencing the Australian organizations to adopt BCT. To achieve this, we conducted a qualitative study based on the Technology, Organization, Environment (TOE) framework. The study proposes a theoretical model grounded on the findings of semi-structured interviews of blockchain experts in Australia. The proposed model shows that the organizational adoption of blockchain is influenced by perceived benefits, compatibility, and complexity, organization innovativeness, organizational learning capability, competitive intensity, government support, trading partner readiness, and standards uncertainty. © 2020, Springer Nature Switzerland AG.
- Authors: Malik, Saleem , Chadhar, Mehmood , Chetty, Madhu , Vatanasakdakul, Savanid
- Date: 2020
- Type: Text , Conference paper
- Relation: 17th European, Mediterranean, and Middle Eastern Conference on Information Systems, EMCIS 2020; Dubai; 25-26 November 2020 Vol. 402, p. 205-220
- Full Text:
- Reviewed:
- Description: Scholarly and commercial literature indicates several applications of Blockchain Technology (BCT) in different industries e.g. health, finance, supply chain, government, and energy. Despite abundant benefits reported and growing prominence, BCT has been facing various challenges across the globe, including low adoption by organizations. There is a dearth of studies that examined the organizational adoption of blockchain technology, particularly in Australia. This lack of uptake provides the rationale to initiate this research to identify the factors influencing the Australian organizations to adopt BCT. To achieve this, we conducted a qualitative study based on the Technology, Organization, Environment (TOE) framework. The study proposes a theoretical model grounded on the findings of semi-structured interviews of blockchain experts in Australia. The proposed model shows that the organizational adoption of blockchain is influenced by perceived benefits, compatibility, and complexity, organization innovativeness, organizational learning capability, competitive intensity, government support, trading partner readiness, and standards uncertainty. © 2020, Springer Nature Switzerland AG.
A multi-proxy approach to track ecological change in Gunbower Wetlands, Victoria, Australia
- Authors: Mall, Neeraj
- Date: 2021
- Type: Text , Thesis , PhD
- Full Text:
- Description: The wetlands of the Murray-Darling Basin have come under the threat of a drying climate, the over-allocation of water for irrigation agriculture and widespread catchment disturbance. A synthesis of many paleolimnological assessments undertaken in the upper and lower sections of the Murray floodplain, and the Murrumbidgee, reveal considerable ecological change in wetlands from early in European settlement. The wetlands of the Gunbower Forest lie in the middle reaches of the Murray River. They are located on Gunbower Island that is deemed a wetland of international significance under the Ramsar Convention and an icon site under the Living Murray Initiative. Many Gunbower Island wetlands are located in protected forests, while others are within a zone developed for irrigation, mostly dairy, agriculture. This study analysed the sedimentary records of two wetlands within the forest estate and two within irrigation lands intending to compare long term change in the Gunbower wetlands to studies on floodplains both up and downstream, and to assess the relative impact of regional causes of change and that of local land use. Sediments constitute natural archives of past environmental changes. Sediment records were recovered from four wetlands and radiometric dating and multi-proxy paleoecological techniques were applied to assess how these wetlands have responded to changes in human occupation and other factors, such as climate. Then, extracted sediment cores were taken from Black (core length: 84 cm) and Green (86 cm) Swamps located in the forest, and Taylors (94 cm) and Cockatoo (74 cm) Lagoons were situated amongst dairy farms. In order to reconstruct ecological and water quality changes from the study sites, the cores were analysed using four different analysis techniques, i.e., Itrax-XRF (X-Ray Fluorescence) scanning, Lead-210 (210Pb) dating, Stable isotope and diatom analysis. XRF scanning provided evidence of the elemental composition of the cores. Detrital enrichment in the lower parts of all cores was observed, indicating elevated erosion rates or low water levels. In addition to this, some recent metal pollution was evident with high Cu, Ni and Pb inputs. Stable isotopes provided limited information on the carbon and nitrogen sources. The
- Description: Doctor of Philosophy
- Authors: Mall, Neeraj
- Date: 2021
- Type: Text , Thesis , PhD
- Full Text:
- Description: The wetlands of the Murray-Darling Basin have come under the threat of a drying climate, the over-allocation of water for irrigation agriculture and widespread catchment disturbance. A synthesis of many paleolimnological assessments undertaken in the upper and lower sections of the Murray floodplain, and the Murrumbidgee, reveal considerable ecological change in wetlands from early in European settlement. The wetlands of the Gunbower Forest lie in the middle reaches of the Murray River. They are located on Gunbower Island that is deemed a wetland of international significance under the Ramsar Convention and an icon site under the Living Murray Initiative. Many Gunbower Island wetlands are located in protected forests, while others are within a zone developed for irrigation, mostly dairy, agriculture. This study analysed the sedimentary records of two wetlands within the forest estate and two within irrigation lands intending to compare long term change in the Gunbower wetlands to studies on floodplains both up and downstream, and to assess the relative impact of regional causes of change and that of local land use. Sediments constitute natural archives of past environmental changes. Sediment records were recovered from four wetlands and radiometric dating and multi-proxy paleoecological techniques were applied to assess how these wetlands have responded to changes in human occupation and other factors, such as climate. Then, extracted sediment cores were taken from Black (core length: 84 cm) and Green (86 cm) Swamps located in the forest, and Taylors (94 cm) and Cockatoo (74 cm) Lagoons were situated amongst dairy farms. In order to reconstruct ecological and water quality changes from the study sites, the cores were analysed using four different analysis techniques, i.e., Itrax-XRF (X-Ray Fluorescence) scanning, Lead-210 (210Pb) dating, Stable isotope and diatom analysis. XRF scanning provided evidence of the elemental composition of the cores. Detrital enrichment in the lower parts of all cores was observed, indicating elevated erosion rates or low water levels. In addition to this, some recent metal pollution was evident with high Cu, Ni and Pb inputs. Stable isotopes provided limited information on the carbon and nitrogen sources. The
- Description: Doctor of Philosophy