Calmness modulus of linear semi-infinite programs
- Cánovas, Maria, Kruger, Alexander, López, Marco, Parra, Juan, Théra, Michel
- Authors: Cánovas, Maria , Kruger, Alexander , López, Marco , Parra, Juan , Théra, Michel
- Date: 2014
- Type: Text , Journal article
- Relation: SIAM Journal on Optimization Vol. 24, no. 1 (2014), p. 29-48
- Relation: http://purl.org/au-research/grants/arc/DP110102011
- Full Text:
- Reviewed:
- Description: Our main goal is to compute or estimate the calmness modulus of the argmin mapping of linear semi-infinite optimization problems under canonical perturbations, i.e., perturbations of the objective function together with continuous perturbations of the right-hand side of the constraint system (with respect to an index ranging in a compact Hausdorff space). Specifically, we provide a lower bound on the calmness modulus for semi-infinite programs with unique optimal solution which turns out to be the exact modulus when the problem is finitely constrained. The relationship between the calmness of the argmin mapping and the same property for the (sub)level set mapping (with respect to the objective function), for semi-infinite programs and without requiring the uniqueness of the nominal solution, is explored, too, providing an upper bound on the calmness modulus of the argmin mapping. When confined to finitely constrained problems, we also provide a computable upper bound as it only relies on the nominal data and parameters, not involving elements in a neighborhood. Illustrative examples are provided.
- Authors: Cánovas, Maria , Kruger, Alexander , López, Marco , Parra, Juan , Théra, Michel
- Date: 2014
- Type: Text , Journal article
- Relation: SIAM Journal on Optimization Vol. 24, no. 1 (2014), p. 29-48
- Relation: http://purl.org/au-research/grants/arc/DP110102011
- Full Text:
- Reviewed:
- Description: Our main goal is to compute or estimate the calmness modulus of the argmin mapping of linear semi-infinite optimization problems under canonical perturbations, i.e., perturbations of the objective function together with continuous perturbations of the right-hand side of the constraint system (with respect to an index ranging in a compact Hausdorff space). Specifically, we provide a lower bound on the calmness modulus for semi-infinite programs with unique optimal solution which turns out to be the exact modulus when the problem is finitely constrained. The relationship between the calmness of the argmin mapping and the same property for the (sub)level set mapping (with respect to the objective function), for semi-infinite programs and without requiring the uniqueness of the nominal solution, is explored, too, providing an upper bound on the calmness modulus of the argmin mapping. When confined to finitely constrained problems, we also provide a computable upper bound as it only relies on the nominal data and parameters, not involving elements in a neighborhood. Illustrative examples are provided.
Cannabis use and anxiety : Is stress the missing piece of the puzzle?
- Temple, Elizabeth, Driver, Matthew, Brown, Rhonda
- Authors: Temple, Elizabeth , Driver, Matthew , Brown, Rhonda
- Date: 2014
- Type: Text , Journal article
- Relation: Frontiers in Psychiatry Vol. 5, no. (2014), p. 1-13
- Full Text:
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- Description: Objective: Comorbidity between anxiety and cannabis use is common yet the nature of the association between these conditions is not clear. Four theories were assessed, and a fifth hypothesis tested to determine if the misattribution of stress symptomology plays a role in the association between state-anxiety and cannabis. Methods: Three-hundred-sixteen participants ranging in age from 18 to 71 years completed a short online questionnaire asking about their history of cannabis use and symptoms of stress and anxiety. Results: Past and current cannabis users reported higher incidence of lifetime anxiety than participants who had never used cannabis; however, these groups did not differ in state-anxiety, stress, or age of onset of anxiety. State-anxiety and stress were not associated with frequency of cannabis use, but reported use to self-medicate for anxiety was positively associated with all three. Path analyses indicated two different associations between anxiety and cannabis use, pre-existing and high state-anxiety was associated with (i) higher average levels of intoxication and, in turn, acute anxiety responses to cannabis use; (ii) frequency of cannabis use via the mediating effects of stress and self-medication. Conclusion: None of the theories was fully supported by the findings. However, as cannabis users reporting self-medication for anxiety were found to be self-medicating stress symptomology, there was some support for the stress-misattribution hypothesis. With reported self-medication for anxiety being the strongest predictor of frequency of use, it is suggested that researchers, clinicians, and cannabis users pay greater attention to the overlap between stress and anxiety symptomology and the possible misinterpretation of these related but distinct conditions. © 2014 Temple, Driver and Brown.
- Authors: Temple, Elizabeth , Driver, Matthew , Brown, Rhonda
- Date: 2014
- Type: Text , Journal article
- Relation: Frontiers in Psychiatry Vol. 5, no. (2014), p. 1-13
- Full Text:
- Reviewed:
- Description: Objective: Comorbidity between anxiety and cannabis use is common yet the nature of the association between these conditions is not clear. Four theories were assessed, and a fifth hypothesis tested to determine if the misattribution of stress symptomology plays a role in the association between state-anxiety and cannabis. Methods: Three-hundred-sixteen participants ranging in age from 18 to 71 years completed a short online questionnaire asking about their history of cannabis use and symptoms of stress and anxiety. Results: Past and current cannabis users reported higher incidence of lifetime anxiety than participants who had never used cannabis; however, these groups did not differ in state-anxiety, stress, or age of onset of anxiety. State-anxiety and stress were not associated with frequency of cannabis use, but reported use to self-medicate for anxiety was positively associated with all three. Path analyses indicated two different associations between anxiety and cannabis use, pre-existing and high state-anxiety was associated with (i) higher average levels of intoxication and, in turn, acute anxiety responses to cannabis use; (ii) frequency of cannabis use via the mediating effects of stress and self-medication. Conclusion: None of the theories was fully supported by the findings. However, as cannabis users reporting self-medication for anxiety were found to be self-medicating stress symptomology, there was some support for the stress-misattribution hypothesis. With reported self-medication for anxiety being the strongest predictor of frequency of use, it is suggested that researchers, clinicians, and cannabis users pay greater attention to the overlap between stress and anxiety symptomology and the possible misinterpretation of these related but distinct conditions. © 2014 Temple, Driver and Brown.
Canonical Dual Algorithms for Global Optimization with Applications
- Authors: Zhou, Xiaojun
- Date: 2014
- Type: Text , Thesis
- Full Text:
- Description: Canonical duality theory provides a unified framework which can transform a nonconvex primal minimization problem to a canonical dual maximization problem over a convex domain without duality gap. But the global optimality is guaranteed by a certain positive definite condition and such condition is not always satisfied. The goal of this thesis aims to explore possible techniques that can be used to solve global optimization problems based on the canonical duality theory. Firstly, an algorithmic framework for canonical duality theory is established, which shows that the canonical dual algorithms can be developed in four aspects under the positive definite condition explicitly or implicitly, namely, (i) minimizing the primal problem, (ii) maximizing the canonical dual problem, (iii) solving a nonlinear equation caused by total complementary function, and (iv) solving a nonlinear equation caused by canonical dual function. Secondly, we show that if there exists a critical point of the canonical dual problem in the positive definite domain, by solving an equivalent semidefinite programming (SDP) problem, the corresponding global solution to the primal problem can be obtained easily via off-the-shelf software packages. A specific canonical dual algorithm is given for each problem, including sum of fourth-order polynomials minimization, nonconvex quadratically constrained quadratic program (QCQP), and boolean quadratic program (BQP). Thirdly, we propose a canonical primal-dual algorithm framework based on the total complementary function. Convergence analysis is discussed from the perspective of variational inequalities (VIs) and contraction methods. Specific canonical primal-dual algorithms for sum of fourth-order polynomials minimization is given as well. And a real-world application to the sensor network localization problem is illustrated. Next, a canonical sequential reduction approach is proposed to recover the approximate or global solution for the BQP problem. By fixing some previously known components, the original problem can be reduced sequentially to a lower dimension one. This approach is successfully applied to the well-known maxcut problem. Finally, we discuss the canonical dual approach applied to continuous time constrained optimal control. And it shows that the optimal control law for the n-dimensional constrained linear quadratic regulator can be achieved precisely via one-dimensional canonical dual variable, and for the optimal control problem with concave cost functional, an approximate solution can be obtained by introducing a linear perturbation term.
- Description: PhD
- Authors: Zhou, Xiaojun
- Date: 2014
- Type: Text , Thesis
- Full Text:
- Description: Canonical duality theory provides a unified framework which can transform a nonconvex primal minimization problem to a canonical dual maximization problem over a convex domain without duality gap. But the global optimality is guaranteed by a certain positive definite condition and such condition is not always satisfied. The goal of this thesis aims to explore possible techniques that can be used to solve global optimization problems based on the canonical duality theory. Firstly, an algorithmic framework for canonical duality theory is established, which shows that the canonical dual algorithms can be developed in four aspects under the positive definite condition explicitly or implicitly, namely, (i) minimizing the primal problem, (ii) maximizing the canonical dual problem, (iii) solving a nonlinear equation caused by total complementary function, and (iv) solving a nonlinear equation caused by canonical dual function. Secondly, we show that if there exists a critical point of the canonical dual problem in the positive definite domain, by solving an equivalent semidefinite programming (SDP) problem, the corresponding global solution to the primal problem can be obtained easily via off-the-shelf software packages. A specific canonical dual algorithm is given for each problem, including sum of fourth-order polynomials minimization, nonconvex quadratically constrained quadratic program (QCQP), and boolean quadratic program (BQP). Thirdly, we propose a canonical primal-dual algorithm framework based on the total complementary function. Convergence analysis is discussed from the perspective of variational inequalities (VIs) and contraction methods. Specific canonical primal-dual algorithms for sum of fourth-order polynomials minimization is given as well. And a real-world application to the sensor network localization problem is illustrated. Next, a canonical sequential reduction approach is proposed to recover the approximate or global solution for the BQP problem. By fixing some previously known components, the original problem can be reduced sequentially to a lower dimension one. This approach is successfully applied to the well-known maxcut problem. Finally, we discuss the canonical dual approach applied to continuous time constrained optimal control. And it shows that the optimal control law for the n-dimensional constrained linear quadratic regulator can be achieved precisely via one-dimensional canonical dual variable, and for the optimal control problem with concave cost functional, an approximate solution can be obtained by introducing a linear perturbation term.
- Description: PhD
Categorising sports injuries in epidemiological studies : the subsequent injury categorisation (SIC) model to address multiple, recurrent and exacerbation of injuries
- Authors: Finch, Caroline , Cook, Jill
- Date: 2014
- Type: Text , Journal article
- Relation: British Journal of Sports Medicine Vol. 48, no.17, p. 1-6
- Relation: http://purl.org/au-research/grants/nhmrc/565900
- Full Text:
- Reviewed:
- Description: Objective: Sports injuries are often recurrent and there is wide recognition that a subsequent injury (of either the same or a different type) can be strongly influenced by a previous injury. Correctly categorising subsequent injuries (multiple, recurrent, exacerbation or new) requires substantial clinical expertise, but there is also considerable value in combining this expertise with more objective statistical criteria. This paper presents a new model, the subsequent injury categorisation (SIC) model, for categorising subsequent sports injuries that takes into account the need to include both acute and overuse injuries and ten different dependency structures between injury types. Methods: The suitability of the SIC model was demonstrated with date ordered sports injury data from a large injury database from community Australian football players over one playing season. A subsequent injury was defined to have occurred in the subset of players with two or more reported injuries. Results: 282 players sustained 469 subsequent injuries of which 15.6% were coded to categories representing injuries that were directly related to previous index injuries. This demonstrates that players can sustain a number of injuries over one playing season. Many of these will be unrelated to previous injuries but subsequent injuries that are related to previous injury occurrences are not uncommon. Conclusion: The handling of subsequent sports injuries is a substantial challenge for the sports medicine field—both in terms of injury treatment and in epidemiological research to quantify them. Application of the SIC model allows for multiple different injury types and relationships within players, as well as different index injuries.
- Authors: Finch, Caroline , Cook, Jill
- Date: 2014
- Type: Text , Journal article
- Relation: British Journal of Sports Medicine Vol. 48, no.17, p. 1-6
- Relation: http://purl.org/au-research/grants/nhmrc/565900
- Full Text:
- Reviewed:
- Description: Objective: Sports injuries are often recurrent and there is wide recognition that a subsequent injury (of either the same or a different type) can be strongly influenced by a previous injury. Correctly categorising subsequent injuries (multiple, recurrent, exacerbation or new) requires substantial clinical expertise, but there is also considerable value in combining this expertise with more objective statistical criteria. This paper presents a new model, the subsequent injury categorisation (SIC) model, for categorising subsequent sports injuries that takes into account the need to include both acute and overuse injuries and ten different dependency structures between injury types. Methods: The suitability of the SIC model was demonstrated with date ordered sports injury data from a large injury database from community Australian football players over one playing season. A subsequent injury was defined to have occurred in the subset of players with two or more reported injuries. Results: 282 players sustained 469 subsequent injuries of which 15.6% were coded to categories representing injuries that were directly related to previous index injuries. This demonstrates that players can sustain a number of injuries over one playing season. Many of these will be unrelated to previous injuries but subsequent injuries that are related to previous injury occurrences are not uncommon. Conclusion: The handling of subsequent sports injuries is a substantial challenge for the sports medicine field—both in terms of injury treatment and in epidemiological research to quantify them. Application of the SIC model allows for multiple different injury types and relationships within players, as well as different index injuries.
Challenges of food security for migrants living in a regional area of Australia : food availability, accessibility and affordability
- Yeoh, Joanne, Le, Quynh, Terry, Daniel, McManamey, Rosa
- Authors: Yeoh, Joanne , Le, Quynh , Terry, Daniel , McManamey, Rosa
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of Food Security Vol. 2, no. 3 (2014), p. 72-78
- Full Text:
- Reviewed:
- Authors: Yeoh, Joanne , Le, Quynh , Terry, Daniel , McManamey, Rosa
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of Food Security Vol. 2, no. 3 (2014), p. 72-78
- Full Text:
- Reviewed:
Changes in muscle activation following balance and technique training and a season of Australian football
- Donnelly, Cyril, Elliott, Bruce, Doyle, Tim, Finch, Caroline, Dempsey, Alasdair, Lloyd, David
- Authors: Donnelly, Cyril , Elliott, Bruce , Doyle, Tim , Finch, Caroline , Dempsey, Alasdair , Lloyd, David
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 18, no. 3 (2014), p.348-352
- Relation: http://purl.org/au-research/grants/nhmrc/565900
- Full Text:
- Reviewed:
- Description: Objectives: Determine if balance and technique training implemented adjunct to 1001 male Australian football players' training influenced the activation/strength of the muscles crossing the knee during pre-planned and unplanned sidestepping. Design: Randomized Control Trial. Methods: Each Australian football player participated in either 28 weeks of balance and technique training or 'sham' training. Twenty-eight Australian football players (balance and technique training, n = 12; 'sham' training, n = 16) completed biomechanical testing pre-to-post training. Peak knee moments and directed co-contraction ratios in three degrees of freedom, as well as total muscle activation were calculated during pre-planned and unplanned sidestepping. Results: No significant differences in muscle activation/strength were observed between the 'sham' training and balance and technique training groups. Following a season of Australian football, knee extensor (p = 0.023) and semimembranosus (p = 0.006) muscle activation increased during both pre-planned sidestepping and unplanned sidestepping. Following a season of Australian football, total muscle activation was 30% lower and peak valgus knee moments 80% greater (p = 0.022) during unplanned sidestepping when compared with pre-planned sidestepping. Conclusions: When implemented in a community level training environment, balance and technique training was not effective in changing the activation of the muscles crossing the knee during sidestepping. Following a season of Australian football, players are better able to support both frontal and sagittal plane knee moments. When compared to pre-planned sidestepping, Australian football players may be at increased risk of anterior cruciate ligament injury during unplanned sidestepping in the latter half of an Australian football season.
- Authors: Donnelly, Cyril , Elliott, Bruce , Doyle, Tim , Finch, Caroline , Dempsey, Alasdair , Lloyd, David
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 18, no. 3 (2014), p.348-352
- Relation: http://purl.org/au-research/grants/nhmrc/565900
- Full Text:
- Reviewed:
- Description: Objectives: Determine if balance and technique training implemented adjunct to 1001 male Australian football players' training influenced the activation/strength of the muscles crossing the knee during pre-planned and unplanned sidestepping. Design: Randomized Control Trial. Methods: Each Australian football player participated in either 28 weeks of balance and technique training or 'sham' training. Twenty-eight Australian football players (balance and technique training, n = 12; 'sham' training, n = 16) completed biomechanical testing pre-to-post training. Peak knee moments and directed co-contraction ratios in three degrees of freedom, as well as total muscle activation were calculated during pre-planned and unplanned sidestepping. Results: No significant differences in muscle activation/strength were observed between the 'sham' training and balance and technique training groups. Following a season of Australian football, knee extensor (p = 0.023) and semimembranosus (p = 0.006) muscle activation increased during both pre-planned sidestepping and unplanned sidestepping. Following a season of Australian football, total muscle activation was 30% lower and peak valgus knee moments 80% greater (p = 0.022) during unplanned sidestepping when compared with pre-planned sidestepping. Conclusions: When implemented in a community level training environment, balance and technique training was not effective in changing the activation of the muscles crossing the knee during sidestepping. Following a season of Australian football, players are better able to support both frontal and sagittal plane knee moments. When compared to pre-planned sidestepping, Australian football players may be at increased risk of anterior cruciate ligament injury during unplanned sidestepping in the latter half of an Australian football season.
Cladoceran-inferred ecological and hydrological changes of two floodplain wetlands in two large river systems, the Murray (Australia) and Yangtze Rivers (China)
- Kattel, Giri, Dong, Xuhui, Yang, Xiangdong
- Authors: Kattel, Giri , Dong, Xuhui , Yang, Xiangdong
- Date: 2014
- Type: Text , Conference paper
- Relation: Symposium on Australia-China Wetland Network Research Partnership; Nanjing Institute of Geography and Limnology Chinese Academy of Sciences (NIGLAS) Nanjing, China; 23rd-28th December 2014 p. 42-49
- Full Text:
- Reviewed:
- Description: The landscapes of two of the world’s large river basins, the Murray and Yangtze Rivers of Australia and China, have been intensively developed for the provision of food and water resources. Long term archives of change, reveal that man-made infrastructures in the river and catchment modifications for agricultural and industrial developments have reduced the resilience of wetlands ecosystem structure and functions in recent decades. The river regulations imposed during the 20th centuries in the Murray and Yangtze Rivers have transformed hydrology and ecology of the river and associated wetlands. High resolution, subfossil cladoceran assemblages retrieved from Kings Billabong and Zhangdu Lake of the Murray and Yangtze Rivers, have strongly responded to human disturbances in the past. Ratios of littoral to planktonic (L:P) assemblages of subfossil cladocerans and the number of ephippial remains in Kings Billabong indicated the shift in hydrology and ecology of Kings Billabong, and ecological stress as a result of changes in naturally occurring dry-wet cycles following river regulation (1927 AD). Similarly, the subfossil cladoceran assemblages and their ephippia in Zhangdu Lake also reflected the impacts of the construction of the Three Gorges Dam (1954) in the Yangtze River on hydrology and ecology of the wetland.
- Authors: Kattel, Giri , Dong, Xuhui , Yang, Xiangdong
- Date: 2014
- Type: Text , Conference paper
- Relation: Symposium on Australia-China Wetland Network Research Partnership; Nanjing Institute of Geography and Limnology Chinese Academy of Sciences (NIGLAS) Nanjing, China; 23rd-28th December 2014 p. 42-49
- Full Text:
- Reviewed:
- Description: The landscapes of two of the world’s large river basins, the Murray and Yangtze Rivers of Australia and China, have been intensively developed for the provision of food and water resources. Long term archives of change, reveal that man-made infrastructures in the river and catchment modifications for agricultural and industrial developments have reduced the resilience of wetlands ecosystem structure and functions in recent decades. The river regulations imposed during the 20th centuries in the Murray and Yangtze Rivers have transformed hydrology and ecology of the river and associated wetlands. High resolution, subfossil cladoceran assemblages retrieved from Kings Billabong and Zhangdu Lake of the Murray and Yangtze Rivers, have strongly responded to human disturbances in the past. Ratios of littoral to planktonic (L:P) assemblages of subfossil cladocerans and the number of ephippial remains in Kings Billabong indicated the shift in hydrology and ecology of Kings Billabong, and ecological stress as a result of changes in naturally occurring dry-wet cycles following river regulation (1927 AD). Similarly, the subfossil cladoceran assemblages and their ephippia in Zhangdu Lake also reflected the impacts of the construction of the Three Gorges Dam (1954) in the Yangtze River on hydrology and ecology of the wetland.
Collaboration success in the dataverse : Libraries as digital humanities research partners
- Owen, Sue, Verhoeven, Deb, Horn, Anne, Robertson, Sabina
- Authors: Owen, Sue , Verhoeven, Deb , Horn, Anne , Robertson, Sabina
- Date: 2014
- Type: Text , Conference proceedings , Conference paper
- Relation: 35th International Association of Scientific and Technological University Libraries Conference (IATUL 2014); Espoo, Finland; 2nd-5th June 2014 p. 1-9
- Full Text:
- Reviewed:
- Description: At Deakin, the Humanities Networked Infrastructure project (HuNI), has paved new ground for facilitating the effective use and re-use of humanities research data. HuNI is one of the first largescale eResearch infrastructure projects for the humanities in Australia and the first national, crossdisciplinary Virtual Laboratory (VL) worldwide. HuNI provides new information infrastructure services for both humanities researchers and members of the public. Its development has been funded by the National eResearch Collaboration Tools and Resources project (NeCTAR) and undertaken by a consortium of thirteen institutions led by Deakin University. A Deakin University Library team with skills in data description, curation, retrieval and preservation is exploring with digital humanities researchers and developers effective means to support and maintain the HuNI project. HuNI ingests and aggregates data from a total of 31 different Australian cultural datasets which cover a wide range of disciplines in the humanities and creative arts. The HuNI VL also provides a number of online research capabilities for humanities researchers to discover and work with the large-scale aggregation of data. The HuNI VL enables researchers to create, save and publish selections of data; to analyse and manipulate the data; share findings and to export the data for reuse in external environments. In a major innovation, HuNI also enables researchers to assert relationships between entities in the form of ‘socially linked’ data. This capability contributes to the building of a ‘vernacular’ network of associations between HuNI records that embody diverse perspectives on knowledge and ramify avenues for research discovery beyond keyword and phrase searches. This paper reports on key milestones in this project, the future role of Libraries as digital humanities research partners and the challenges and sustainability issues that face national digital humanities research projects that are developed in strategic library settings.
- Authors: Owen, Sue , Verhoeven, Deb , Horn, Anne , Robertson, Sabina
- Date: 2014
- Type: Text , Conference proceedings , Conference paper
- Relation: 35th International Association of Scientific and Technological University Libraries Conference (IATUL 2014); Espoo, Finland; 2nd-5th June 2014 p. 1-9
- Full Text:
- Reviewed:
- Description: At Deakin, the Humanities Networked Infrastructure project (HuNI), has paved new ground for facilitating the effective use and re-use of humanities research data. HuNI is one of the first largescale eResearch infrastructure projects for the humanities in Australia and the first national, crossdisciplinary Virtual Laboratory (VL) worldwide. HuNI provides new information infrastructure services for both humanities researchers and members of the public. Its development has been funded by the National eResearch Collaboration Tools and Resources project (NeCTAR) and undertaken by a consortium of thirteen institutions led by Deakin University. A Deakin University Library team with skills in data description, curation, retrieval and preservation is exploring with digital humanities researchers and developers effective means to support and maintain the HuNI project. HuNI ingests and aggregates data from a total of 31 different Australian cultural datasets which cover a wide range of disciplines in the humanities and creative arts. The HuNI VL also provides a number of online research capabilities for humanities researchers to discover and work with the large-scale aggregation of data. The HuNI VL enables researchers to create, save and publish selections of data; to analyse and manipulate the data; share findings and to export the data for reuse in external environments. In a major innovation, HuNI also enables researchers to assert relationships between entities in the form of ‘socially linked’ data. This capability contributes to the building of a ‘vernacular’ network of associations between HuNI records that embody diverse perspectives on knowledge and ramify avenues for research discovery beyond keyword and phrase searches. This paper reports on key milestones in this project, the future role of Libraries as digital humanities research partners and the challenges and sustainability issues that face national digital humanities research projects that are developed in strategic library settings.
Collembola (Springtails)
- Greenslade, Penelope, Florentine, Singarayer
- Authors: Greenslade, Penelope , Florentine, Singarayer
- Date: 2014
- Type: Text , Book chapter
- Relation: The distributions of invertebrate species along the Warra/Mt Weld altitudinal transect 2001/2002 and identification of taxa restricted by altitude (part of the Nature Conservation Report Series 13/4) Chapter 6 p.1-73
- Full Text:
- Reviewed:
- Description: Summary 1. The distributions of Collembola on the Warra-Mount Weld Altitudinal Transect were investigated based on samples taken from February–April 2001, November–December 2001 and January– February 2002. 2. The Collembola of the Warra-Mount Weld Altitudinal Transect was species rich with more than 40 species collected; the majority of species recorded have not been described. 3. Most of the species collected are considered endemic to Tasmania and some endemic genera were present. 4. The Malaise traps performed well indicating that a suite of species are arboreal and highly vagile. 5. No exotic (introduced, alien) species were detected in this study indicating that the area sampled has been little disturbed and is of high conservation value. 6. Altitudinal trends were evident with a small number of species only occurring at the high altitudes and others only at low altitudes. Only a few species appeared to occur at all altitudes sampled. 7. Ordination plots showed that Collembola assemblages at lower altitude sites on the Warra transect were more similar to each other than those at the higher altitude sites on Mount Weld which formed three clusters: 1100; 1200 and 1300 m; and 800, 900 and 1000 m. 8. Mount Weld sites 600 and 700 m faunas were most similar to Warra sites so forming a continuum in altitudinal zonation between Warra and Mount Weld. 9. PERMANOVA analysis of monthly pitfall catches in 2001 and 2002 showed differences between months and altitudes on both transects and that the differences between months were more distinct at the lower altitude Warra sites than on the higher altitude Mount Weld sites. This difference was particularly marked for the month of February, which was the only month surveyed in both years. 10.Much of the change in faunal assemblages along the Warra and Mount Weld altitudinal transect seemed to be the result of changes in vegetation cover. The most abrupt faunal transitions took place across the tree line between 1000 and 1100 m and a smaller change from lowland forest to subalpine woodland on the Mount Weld transect. 11.Much material in the pitfalls was in very poor condition because of the long trapping time with unsuitable preservative so could not be identified to species but rough estimates were made of numbers of individuals in each family or genus.
- Authors: Greenslade, Penelope , Florentine, Singarayer
- Date: 2014
- Type: Text , Book chapter
- Relation: The distributions of invertebrate species along the Warra/Mt Weld altitudinal transect 2001/2002 and identification of taxa restricted by altitude (part of the Nature Conservation Report Series 13/4) Chapter 6 p.1-73
- Full Text:
- Reviewed:
- Description: Summary 1. The distributions of Collembola on the Warra-Mount Weld Altitudinal Transect were investigated based on samples taken from February–April 2001, November–December 2001 and January– February 2002. 2. The Collembola of the Warra-Mount Weld Altitudinal Transect was species rich with more than 40 species collected; the majority of species recorded have not been described. 3. Most of the species collected are considered endemic to Tasmania and some endemic genera were present. 4. The Malaise traps performed well indicating that a suite of species are arboreal and highly vagile. 5. No exotic (introduced, alien) species were detected in this study indicating that the area sampled has been little disturbed and is of high conservation value. 6. Altitudinal trends were evident with a small number of species only occurring at the high altitudes and others only at low altitudes. Only a few species appeared to occur at all altitudes sampled. 7. Ordination plots showed that Collembola assemblages at lower altitude sites on the Warra transect were more similar to each other than those at the higher altitude sites on Mount Weld which formed three clusters: 1100; 1200 and 1300 m; and 800, 900 and 1000 m. 8. Mount Weld sites 600 and 700 m faunas were most similar to Warra sites so forming a continuum in altitudinal zonation between Warra and Mount Weld. 9. PERMANOVA analysis of monthly pitfall catches in 2001 and 2002 showed differences between months and altitudes on both transects and that the differences between months were more distinct at the lower altitude Warra sites than on the higher altitude Mount Weld sites. This difference was particularly marked for the month of February, which was the only month surveyed in both years. 10.Much of the change in faunal assemblages along the Warra and Mount Weld altitudinal transect seemed to be the result of changes in vegetation cover. The most abrupt faunal transitions took place across the tree line between 1000 and 1100 m and a smaller change from lowland forest to subalpine woodland on the Mount Weld transect. 11.Much material in the pitfalls was in very poor condition because of the long trapping time with unsuitable preservative so could not be identified to species but rough estimates were made of numbers of individuals in each family or genus.
Colour-temperature correspondences : When reactions to thermal stimuli are influenced by colour
- Ho, Hsin-Ni, Van Doorn, George, Watanabe, Takahiro, Spence, Charles
- Authors: Ho, Hsin-Ni , Van Doorn, George , Watanabe, Takahiro , Spence, Charles
- Date: 2014
- Type: Text , Journal article
- Relation: PLoS One Vol. 9, no. 3 (2014), p. e91854
- Full Text:
- Reviewed:
- Description: In our daily lives, information concerning temperature is often provided by means of colour cues, with red typically being associated with warm/hot, and blue with cold. While such correspondences have been known about for many years, they have primarily been studied using subjective report measures. Here we examined this correspondence using two more objective response measures. First, we used the Implicit Association Test (IAT), a test designed to assess the strength of automatic associations between different concepts in a given individual. Second, we used a priming task that involved speeded target discrimination in order to assess whether priming colour or thermal information could invoke the crossmodal association. The results of the IAT confirmed that the association exists at the level of response selection, thus indicating that a participant's responses to colour or thermal stimuli are influenced by the colour-temperature correspondence. The results of the priming experiment revealed that priming a colour affected thermal discrimination reaction times (RTs), but thermal cues did not influence colour discrimination responses. These results may therefore provide important clues as to the level of processing at which such colour-temperature correspondences are represented.
- Authors: Ho, Hsin-Ni , Van Doorn, George , Watanabe, Takahiro , Spence, Charles
- Date: 2014
- Type: Text , Journal article
- Relation: PLoS One Vol. 9, no. 3 (2014), p. e91854
- Full Text:
- Reviewed:
- Description: In our daily lives, information concerning temperature is often provided by means of colour cues, with red typically being associated with warm/hot, and blue with cold. While such correspondences have been known about for many years, they have primarily been studied using subjective report measures. Here we examined this correspondence using two more objective response measures. First, we used the Implicit Association Test (IAT), a test designed to assess the strength of automatic associations between different concepts in a given individual. Second, we used a priming task that involved speeded target discrimination in order to assess whether priming colour or thermal information could invoke the crossmodal association. The results of the IAT confirmed that the association exists at the level of response selection, thus indicating that a participant's responses to colour or thermal stimuli are influenced by the colour-temperature correspondence. The results of the priming experiment revealed that priming a colour affected thermal discrimination reaction times (RTs), but thermal cues did not influence colour discrimination responses. These results may therefore provide important clues as to the level of processing at which such colour-temperature correspondences are represented.
Comorbidity structure of psychological disorders in the online e-PASS data as predictors of psychosocial adjustment measures: psychological distress, adequate social support, self-confidence, quality of life, and suicidal ideation
- Al-Asadi, Ali, Klein, Britt, Meyer, Denny
- Authors: Al-Asadi, Ali , Klein, Britt , Meyer, Denny
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of Medical Internet Research Vol. 16, no. 10 (2014), p. e248
- Full Text:
- Reviewed:
- Description: BACKGROUND: A relative newcomer to the field of psychology, e-mental health has been gaining momentum and has been given considerable research attention. Although several aspects of e-mental health have been studied, 1 aspect has yet to receive attention: the structure of comorbidity of psychological disorders and their relationships with measures of psychosocial adjustment including suicidal ideation in online samples. OBJECTIVE: This exploratory study attempted to identify the structure of comorbidity of 21 psychological disorders assessed by an automated online electronic psychological assessment screening system (e-PASS). The resulting comorbidity factor scores were then used to assess the association between comorbidity factor scores and measures of psychosocial adjustments (ie, psychological distress, suicidal ideation, adequate social support, self-confidence in dealing with mental health issues, and quality of life). METHODS: A total of 13,414 participants were assessed using a complex online algorithm that resulted in primary and secondary Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revision) diagnoses for 21 psychological disorders on dimensional severity scales. The scores on these severity scales were used in a principal component analysis (PCA) and the resulting comorbidity factor scores were related to 4 measures of psychosocial adjustments. RESULTS: A PCA based on 17 of the 21 psychological disorders resulted in a 4-factor model of comorbidity: anxiety-depression consisting of all anxiety disorders, major depressive episode (MDE), and insomnia; substance abuse consisting of alcohol and drug abuse and dependency; body image-eating consisting of eating disorders, body dysmorphic disorder, and obsessive-compulsive disorders; depression-sleep problems consisting of MDE, insomnia, and hypersomnia. All comorbidity factor scores were significantly associated with psychosocial measures of adjustment (P<.001). They were positively related to psychological distress and suicidal ideation, but negatively related to adequate social support, self-confidence, and quality of life. CONCLUSIONS: This exploratory study identified 4 comorbidity factors in the e-PASS data and these factor scores significantly predicted 5 psychosocial adjustment measures. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry ACTRN121611000704998; http://www.anzctr.org.au/trial_view.aspx?ID=336143 (Archived by WebCite at http://www.webcitation.org/618r3wvOG).
- Authors: Al-Asadi, Ali , Klein, Britt , Meyer, Denny
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of Medical Internet Research Vol. 16, no. 10 (2014), p. e248
- Full Text:
- Reviewed:
- Description: BACKGROUND: A relative newcomer to the field of psychology, e-mental health has been gaining momentum and has been given considerable research attention. Although several aspects of e-mental health have been studied, 1 aspect has yet to receive attention: the structure of comorbidity of psychological disorders and their relationships with measures of psychosocial adjustment including suicidal ideation in online samples. OBJECTIVE: This exploratory study attempted to identify the structure of comorbidity of 21 psychological disorders assessed by an automated online electronic psychological assessment screening system (e-PASS). The resulting comorbidity factor scores were then used to assess the association between comorbidity factor scores and measures of psychosocial adjustments (ie, psychological distress, suicidal ideation, adequate social support, self-confidence in dealing with mental health issues, and quality of life). METHODS: A total of 13,414 participants were assessed using a complex online algorithm that resulted in primary and secondary Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revision) diagnoses for 21 psychological disorders on dimensional severity scales. The scores on these severity scales were used in a principal component analysis (PCA) and the resulting comorbidity factor scores were related to 4 measures of psychosocial adjustments. RESULTS: A PCA based on 17 of the 21 psychological disorders resulted in a 4-factor model of comorbidity: anxiety-depression consisting of all anxiety disorders, major depressive episode (MDE), and insomnia; substance abuse consisting of alcohol and drug abuse and dependency; body image-eating consisting of eating disorders, body dysmorphic disorder, and obsessive-compulsive disorders; depression-sleep problems consisting of MDE, insomnia, and hypersomnia. All comorbidity factor scores were significantly associated with psychosocial measures of adjustment (P<.001). They were positively related to psychological distress and suicidal ideation, but negatively related to adequate social support, self-confidence, and quality of life. CONCLUSIONS: This exploratory study identified 4 comorbidity factors in the e-PASS data and these factor scores significantly predicted 5 psychosocial adjustment measures. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry ACTRN121611000704998; http://www.anzctr.org.au/trial_view.aspx?ID=336143 (Archived by WebCite at http://www.webcitation.org/618r3wvOG).
Condition monitoring techniques of the wind turbines gearbox and rotor
- Salem, Abdulwahed, Abu-Siada, Ahmed, Islam, Syed
- Authors: Salem, Abdulwahed , Abu-Siada, Ahmed , Islam, Syed
- Date: 2014
- Type: Text , Journal article , Conference paper
- Relation: 6th International Conference on Computer and Electrical Engineering (ICCEE 2013); Paris, France; 30th-31st December 2013; published in International Journal of Electrical Energy Vol. 2, no. 1 (2014), p. 53-56
- Full Text:
- Reviewed:
- Description: Gearbox and the blades are classified as the most critical and expensive components of the wind turbine. Moreover, these parts are prone to high risk failure when compared to the rest of the wind turbine components. Due to the global significant increase in wind turbines, a reliable and cost effective condition monitoring technique is essential to maintain the availability and to improve the reliability of wind turbines. This paper aims to present a comprehensive review of the latest condition monitoring techniques for turbine gearbox and blades which are considered as the crux of any wind energy conversion system.
- Authors: Salem, Abdulwahed , Abu-Siada, Ahmed , Islam, Syed
- Date: 2014
- Type: Text , Journal article , Conference paper
- Relation: 6th International Conference on Computer and Electrical Engineering (ICCEE 2013); Paris, France; 30th-31st December 2013; published in International Journal of Electrical Energy Vol. 2, no. 1 (2014), p. 53-56
- Full Text:
- Reviewed:
- Description: Gearbox and the blades are classified as the most critical and expensive components of the wind turbine. Moreover, these parts are prone to high risk failure when compared to the rest of the wind turbine components. Due to the global significant increase in wind turbines, a reliable and cost effective condition monitoring technique is essential to maintain the availability and to improve the reliability of wind turbines. This paper aims to present a comprehensive review of the latest condition monitoring techniques for turbine gearbox and blades which are considered as the crux of any wind energy conversion system.
Contributions of single–phase rooftop PVs on short circuits faults in residential feeders
- Yengejeh, Hadi, Shahnia, Farhad, Islam, Syed
- Authors: Yengejeh, Hadi , Shahnia, Farhad , Islam, Syed
- Date: 2014
- Type: Text , Conference proceedings , Conference paper
- Relation: 24th Australasian Universities Power Engineering Conference, AUPEC 2014; Perth, Australia; 28th September-1st October 2014 p. 1-6
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- Description: Sensitivity analysis results are presented to investigate the presence of single–phase rooftop Photovoltaic Cells (PV) in low voltage residential feeders, during short circuits in the overhead lines. The PV rating and location in the feeder and the fault location are considered as the variables of the sensitivity analysis. The single–phase faults are the main focus of this paper and the PV effect on fault current, current in distribution transformer secondary and the voltage at each bus of the feeder are investigated, during fault. Furthermore, to analyze the bus voltages and fault current in the presence of multiple PVs, each with different rating and location, a stochastic analysis is carried out to investigate the expected probability density function of these parameters, considering the uncertainties of PV rating and location as well as fault location.
- Authors: Yengejeh, Hadi , Shahnia, Farhad , Islam, Syed
- Date: 2014
- Type: Text , Conference proceedings , Conference paper
- Relation: 24th Australasian Universities Power Engineering Conference, AUPEC 2014; Perth, Australia; 28th September-1st October 2014 p. 1-6
- Full Text:
- Reviewed:
- Description: Sensitivity analysis results are presented to investigate the presence of single–phase rooftop Photovoltaic Cells (PV) in low voltage residential feeders, during short circuits in the overhead lines. The PV rating and location in the feeder and the fault location are considered as the variables of the sensitivity analysis. The single–phase faults are the main focus of this paper and the PV effect on fault current, current in distribution transformer secondary and the voltage at each bus of the feeder are investigated, during fault. Furthermore, to analyze the bus voltages and fault current in the presence of multiple PVs, each with different rating and location, a stochastic analysis is carried out to investigate the expected probability density function of these parameters, considering the uncertainties of PV rating and location as well as fault location.
Could pathophysiology failure be ruled out?
- Authors: Wang, Yutang
- Date: 2014
- Type: Text , Letter
- Relation: American Journal of Medicine Vol. 2014, no. 127 (2014), p. e29
- Relation: http://purl.org/au-research/grants/nhmrc/1062671
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- Authors: Wang, Yutang
- Date: 2014
- Type: Text , Letter
- Relation: American Journal of Medicine Vol. 2014, no. 127 (2014), p. e29
- Relation: http://purl.org/au-research/grants/nhmrc/1062671
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Credit transfer from VET to higher education: a pathways policy meets a roadblock.
- Smith, Erica, Kemmis, Ros Brennan
- Authors: Smith, Erica , Kemmis, Ros Brennan
- Date: 2014
- Type: Text , Journal article
- Relation: Research in Post-Compulsory Education Vol. 19, no. 2 (2014), p. 230-244
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- Description: Higher education is increasingly available to a wider range of people, not just recent school-leavers with established academic ability. One way of encouraging this trend is to provide credit transfer into higher education (HE) qualifications for people’s prior vocational education and training (VET) studies. However, it is generally recognised that while a range of pathways have been created, the numbers of students involved in such pathways are relatively limited. This paper explores some of the reasons this might be so, using, as a case study, an analysis of a national Australian government policy initiative. The initiative, known as ‘VET FEE-HELP’, involved the introduction of student loans for fees for higher-level VET studies and was designed partly to encourage credit transfer. Availability of loans to students was on the proviso that the course in which the student enrolled had a documented pathway providing credit transfer into a higher education course. This created a climate in which VET providers actively pursued partnerships with higher education. But recently, the credit transfer requirement of the policy has been removed. The paper concludes by discussing the issues for governments in finding appropriate policy levers to increase proportions of students transferring from VET to higher education.
- Description: C1
- Authors: Smith, Erica , Kemmis, Ros Brennan
- Date: 2014
- Type: Text , Journal article
- Relation: Research in Post-Compulsory Education Vol. 19, no. 2 (2014), p. 230-244
- Full Text:
- Reviewed:
- Description: Higher education is increasingly available to a wider range of people, not just recent school-leavers with established academic ability. One way of encouraging this trend is to provide credit transfer into higher education (HE) qualifications for people’s prior vocational education and training (VET) studies. However, it is generally recognised that while a range of pathways have been created, the numbers of students involved in such pathways are relatively limited. This paper explores some of the reasons this might be so, using, as a case study, an analysis of a national Australian government policy initiative. The initiative, known as ‘VET FEE-HELP’, involved the introduction of student loans for fees for higher-level VET studies and was designed partly to encourage credit transfer. Availability of loans to students was on the proviso that the course in which the student enrolled had a documented pathway providing credit transfer into a higher education course. This created a climate in which VET providers actively pursued partnerships with higher education. But recently, the credit transfer requirement of the policy has been removed. The paper concludes by discussing the issues for governments in finding appropriate policy levers to increase proportions of students transferring from VET to higher education.
- Description: C1
Current continuing professional education practice among Malaysian nurses
- Chan Chong, Mei, Francis, Karen, Cooper, Simon J., Abdullah, Khatijah Lim
- Authors: Chan Chong, Mei , Francis, Karen , Cooper, Simon J. , Abdullah, Khatijah Lim
- Date: 2014
- Type: Text , Journal article
- Relation: Nursing Research and Practice. Vol. 2014, Article ID 126748
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- Description: Nurses need to participate in CPE to update their knowledge and increase their competencies. This research was carried out to explore their current practice and the future general needs for CPE. This cross-sectional descriptive study involved registered nurses from government hospitals and health clinics from Peninsular Malaysia. Multistage cluster sampling was used to recruit 1000 nurses from four states of Malaysia. Self-explanatory questionnaires were used to collect the data, which were analyzed using SPSS version 16. Seven hundred and ninety-two nurses participated in this survey. Only 80% (562) of the nurses had engaged in CPE activities during the past 12 months. All attendance for the various activities was below 50%. Workshops were the most popular CPE activity (345, 43.6%) and tertiary education was the most unpopular activity (10, 1.3%). The respondents did perceive the importance of future CPE activities for career development. Mandatory continuing professional education (MCPE) is a key measure to ensure that nurses upgrade their knowledge and skills; however, it is recommended that policy makers and nurse leaders in the continuing professional development unit of health service facilities plan CPE activities to meet registered nurses’ (RNs) needs and not simply organizational requirements.
- Authors: Chan Chong, Mei , Francis, Karen , Cooper, Simon J. , Abdullah, Khatijah Lim
- Date: 2014
- Type: Text , Journal article
- Relation: Nursing Research and Practice. Vol. 2014, Article ID 126748
- Full Text:
- Reviewed:
- Description: Nurses need to participate in CPE to update their knowledge and increase their competencies. This research was carried out to explore their current practice and the future general needs for CPE. This cross-sectional descriptive study involved registered nurses from government hospitals and health clinics from Peninsular Malaysia. Multistage cluster sampling was used to recruit 1000 nurses from four states of Malaysia. Self-explanatory questionnaires were used to collect the data, which were analyzed using SPSS version 16. Seven hundred and ninety-two nurses participated in this survey. Only 80% (562) of the nurses had engaged in CPE activities during the past 12 months. All attendance for the various activities was below 50%. Workshops were the most popular CPE activity (345, 43.6%) and tertiary education was the most unpopular activity (10, 1.3%). The respondents did perceive the importance of future CPE activities for career development. Mandatory continuing professional education (MCPE) is a key measure to ensure that nurses upgrade their knowledge and skills; however, it is recommended that policy makers and nurse leaders in the continuing professional development unit of health service facilities plan CPE activities to meet registered nurses’ (RNs) needs and not simply organizational requirements.
Current status for gastrointestinal nematode diagnosis in small ruminants: where are we and where are we going?
- Preston, Sarah, Sandeman, Mark, Gonzalez, Jorge, Piedrafita, David
- Authors: Preston, Sarah , Sandeman, Mark , Gonzalez, Jorge , Piedrafita, David
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of immunology research Vol. 2014, no. September (2014), p. Article no. 210350
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- Description: Gastrointestinal nematode (GIN) parasites pose a significant economic burden particularly in small ruminant production systems. Anthelmintic resistance is a serious concern to the effective control of GIN parasites and has fuelled the focus to design and promote sustainable control of practices of parasite control. Many facets of sustainable GIN parasite control programs rely on the ability to diagnose infection both qualitatively and quantitatively. Diagnostics are required to determine anthelmintic efficacies, for targeted treatment programs and selection of animals for parasite resistant breeding. This review describes much of the research investigated to date to improve the current diagnostic for the above practices which is based on counting the number of parasite eggs in faeces.
- Authors: Preston, Sarah , Sandeman, Mark , Gonzalez, Jorge , Piedrafita, David
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of immunology research Vol. 2014, no. September (2014), p. Article no. 210350
- Full Text:
- Reviewed:
- Description: Gastrointestinal nematode (GIN) parasites pose a significant economic burden particularly in small ruminant production systems. Anthelmintic resistance is a serious concern to the effective control of GIN parasites and has fuelled the focus to design and promote sustainable control of practices of parasite control. Many facets of sustainable GIN parasite control programs rely on the ability to diagnose infection both qualitatively and quantitatively. Diagnostics are required to determine anthelmintic efficacies, for targeted treatment programs and selection of animals for parasite resistant breeding. This review describes much of the research investigated to date to improve the current diagnostic for the above practices which is based on counting the number of parasite eggs in faeces.
Delayed self-regulation and time-dependent chemical drive leads to novel states in epigenetic landscapes
- Mitra, Mitra, Taylor, Paul, Hutchison, Chris, McLeish, T. C. B., Chakrabarti, Buddapriya
- Authors: Mitra, Mitra , Taylor, Paul , Hutchison, Chris , McLeish, T. C. B. , Chakrabarti, Buddapriya
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of the Royal Society Interface Vol. 11, no. 100 (2014), p.
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- Reviewed:
- Description: The epigenetic pathway of a cell as it differentiates from a stem cell state to a mature lineage-committed one has been historically understood in terms of Waddington's landscape, consisting of hills and valleys. The smooth top and valley-strewn bottom of the hill represent their undifferentiated and differentiated states, respectively. Although mathematical ideas rooted in nonlinear dynamics and bifurcation theory have been used to quantify this picture, the importance of time delays arising from multistep chemical reactions or cellular shape transformations have been ignored so far.We argue that this feature is crucial in understanding cell differentiation and explore the role of time delay in a model of a single-gene regulatory circuit.We show that the interplay of time-dependent drive and delay introduces a new regime where the system shows sustained oscillations between the two admissible steady states. We interpret these results in the light of recent perplexing experiments on inducing the pluripotent state in mouse somatic cells.We also comment on howsuch an oscillatory state can provide a framework for understanding more general feedback circuits in cell development. © 2014 The Author(s) Published by the Royal Society. All rights reserved.
- Description: The epigenetic pathway of a cell as it differentiates from a stem cell state to a mature lineage-committed one has been historically understood in terms of Waddington's landscape, consisting of hills and valleys. The smooth top and valley-strewn bottom of the hill represent their undifferentiated and differentiated states, respectively. Although mathematical ideas rooted in nonlinear dynamics and bifurcation theory have been used to quantify this picture, the importance of time delays arising from multistep chemical reactions or cellular shape transformations have been ignored so far.We argue that this feature is crucial in understanding cell differentiation and explore the role of time delay in a model of a single-gene regulatory circuit.We showthat the interplay of time-dependent drive and delay introduces a new regime where the system shows sustained oscillations between the two admissible steady states. We interpret these results in the light of recent perplexing experiments on inducing the pluripotent state in mouse somatic cells.We also comment on howsuch an oscillatory state can provide a framework for understanding more general feedback circuits in cell development. © 2014 The Author(s) Published by the Royal Society. All rights reserved.
- Authors: Mitra, Mitra , Taylor, Paul , Hutchison, Chris , McLeish, T. C. B. , Chakrabarti, Buddapriya
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of the Royal Society Interface Vol. 11, no. 100 (2014), p.
- Full Text:
- Reviewed:
- Description: The epigenetic pathway of a cell as it differentiates from a stem cell state to a mature lineage-committed one has been historically understood in terms of Waddington's landscape, consisting of hills and valleys. The smooth top and valley-strewn bottom of the hill represent their undifferentiated and differentiated states, respectively. Although mathematical ideas rooted in nonlinear dynamics and bifurcation theory have been used to quantify this picture, the importance of time delays arising from multistep chemical reactions or cellular shape transformations have been ignored so far.We argue that this feature is crucial in understanding cell differentiation and explore the role of time delay in a model of a single-gene regulatory circuit.We show that the interplay of time-dependent drive and delay introduces a new regime where the system shows sustained oscillations between the two admissible steady states. We interpret these results in the light of recent perplexing experiments on inducing the pluripotent state in mouse somatic cells.We also comment on howsuch an oscillatory state can provide a framework for understanding more general feedback circuits in cell development. © 2014 The Author(s) Published by the Royal Society. All rights reserved.
- Description: The epigenetic pathway of a cell as it differentiates from a stem cell state to a mature lineage-committed one has been historically understood in terms of Waddington's landscape, consisting of hills and valleys. The smooth top and valley-strewn bottom of the hill represent their undifferentiated and differentiated states, respectively. Although mathematical ideas rooted in nonlinear dynamics and bifurcation theory have been used to quantify this picture, the importance of time delays arising from multistep chemical reactions or cellular shape transformations have been ignored so far.We argue that this feature is crucial in understanding cell differentiation and explore the role of time delay in a model of a single-gene regulatory circuit.We showthat the interplay of time-dependent drive and delay introduces a new regime where the system shows sustained oscillations between the two admissible steady states. We interpret these results in the light of recent perplexing experiments on inducing the pluripotent state in mouse somatic cells.We also comment on howsuch an oscillatory state can provide a framework for understanding more general feedback circuits in cell development. © 2014 The Author(s) Published by the Royal Society. All rights reserved.
DELVE14
- Authors: Wojciechowski, Noirin
- Date: 2014
- Type: Text , Visual art work
- Full Text:
- Description: Masters and PhD Research students at the Arts Academy, Ballarat, present their recent work at the Post Office Gallery in an exhibition which reflects diverse ideas and bold approaches to their work and chosen field of inquiry.
- Authors: Wojciechowski, Noirin
- Date: 2014
- Type: Text , Visual art work
- Full Text:
- Description: Masters and PhD Research students at the Arts Academy, Ballarat, present their recent work at the Post Office Gallery in an exhibition which reflects diverse ideas and bold approaches to their work and chosen field of inquiry.
Detection of enteric viral and bacterial pathogens associated with paediatric diarrhoea in Goroka, Papua New Guinea
- Soli, Kevin, Maure, Tobias, Kas, Monalisa, Bande, Grace, Bebes, Sauli, Luang-Suarkia, Dagwin, Siba, Peter, Morita, Ayako, Umezaki, Masahiro, Greenhill, Andrew, Horwood, Paul
- Authors: Soli, Kevin , Maure, Tobias , Kas, Monalisa , Bande, Grace , Bebes, Sauli , Luang-Suarkia, Dagwin , Siba, Peter , Morita, Ayako , Umezaki, Masahiro , Greenhill, Andrew , Horwood, Paul
- Date: 2014
- Type: Text , Journal article
- Relation: International Journal of Infectious Diseases Vol. 27, no. (2014), p. 54-58
- Full Text:
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- Description: Objectives: The aim of this study was to investigate the viral and bacterial causes of acute watery diarrhoea in hospitalized children in Papua New Guinea. Methods: A retrospective analysis was conducted on stool samples collected from 199 children (age > 5 years) admitted to the paediatric ward of Goroka General Hospital from August 2009 through November 2010. A large range of viral and bacterial enteric pathogens were targeted using real-time PCR/RT-PCR assays. Results: Young children were much more likely to be admitted with acute gastroenteritis, with 62.8% of patients aged >1 year and 88.4% aged >2 years. An enteric pathogen was detected in 69.8% (n= 138) of patients. The most commonly detected pathogens were Shigella spp (26.6%), rotavirus (25.6%), adenovirus types 40/41 (11.6%), enterotoxigenic Escherichia coli (11.1%), enteropathogenic E. coli (8.5%), norovirus G2 (6.0%), and Campylobacter spp (4.0%). Norovirus G1, sapovirus, and Salmonella spp were also detected, but below our statistical limit of detection. Vibrio cholerae and astrovirus were not detected in any patients. Mixed infections were detected in 22.1% of patients, with Shigella and rotavirus most commonly detected in co-infections with other pathogens. Conclusions: This study demonstrates that Shigella and rotavirus are the major pathogens associated with acute paediatric gastroenteritis in this setting. © 2014 The Authors.
- Authors: Soli, Kevin , Maure, Tobias , Kas, Monalisa , Bande, Grace , Bebes, Sauli , Luang-Suarkia, Dagwin , Siba, Peter , Morita, Ayako , Umezaki, Masahiro , Greenhill, Andrew , Horwood, Paul
- Date: 2014
- Type: Text , Journal article
- Relation: International Journal of Infectious Diseases Vol. 27, no. (2014), p. 54-58
- Full Text:
- Reviewed:
- Description: Objectives: The aim of this study was to investigate the viral and bacterial causes of acute watery diarrhoea in hospitalized children in Papua New Guinea. Methods: A retrospective analysis was conducted on stool samples collected from 199 children (age > 5 years) admitted to the paediatric ward of Goroka General Hospital from August 2009 through November 2010. A large range of viral and bacterial enteric pathogens were targeted using real-time PCR/RT-PCR assays. Results: Young children were much more likely to be admitted with acute gastroenteritis, with 62.8% of patients aged >1 year and 88.4% aged >2 years. An enteric pathogen was detected in 69.8% (n= 138) of patients. The most commonly detected pathogens were Shigella spp (26.6%), rotavirus (25.6%), adenovirus types 40/41 (11.6%), enterotoxigenic Escherichia coli (11.1%), enteropathogenic E. coli (8.5%), norovirus G2 (6.0%), and Campylobacter spp (4.0%). Norovirus G1, sapovirus, and Salmonella spp were also detected, but below our statistical limit of detection. Vibrio cholerae and astrovirus were not detected in any patients. Mixed infections were detected in 22.1% of patients, with Shigella and rotavirus most commonly detected in co-infections with other pathogens. Conclusions: This study demonstrates that Shigella and rotavirus are the major pathogens associated with acute paediatric gastroenteritis in this setting. © 2014 The Authors.