Annual ryegrass (Lolium rigidum Gaud) competition altered wheat grain quality : A study under elevated atmospheric CO2 levels and drought conditions
- Fernando, Nimesha, Florentine, Singarayer, Naiker, Mani, Panozzo, Joe, Chauhan, Bhagirath
- Authors: Fernando, Nimesha , Florentine, Singarayer , Naiker, Mani , Panozzo, Joe , Chauhan, Bhagirath
- Date: 2019
- Type: Text , Journal article
- Relation: Food Chemistry Vol. 276, no. (2019), p. 285-290
- Full Text:
- Reviewed:
- Description: Annual ryegrass is one of the most serious, costly weeds of winter cropping systems in Australia. To determine whether its competition-mediated plant defence mechanisms effect on wheat grain quality, wheat (cv. Yitpi) and annual ryegrass were grown under two levels of CO2 (400 ppm; (a[CO2]) vs 700 ppm; (e[CO2]), two levels of water (well-watered vs drought) and two types of competition (wheat only; (W), and wheatxannual ryegrass; (W x R) with four replicates. The competitionx[CO2] interaction had a significant effect on wheat grain protein content, where it was increased in W x R under both e[CO2] (+ 17%) and a[CO2] (+ 21%). Grain yield, total grain reducing power and phenolic content were significantly affected by [CO2] x drought x competition. In a summary, annual ryegrass competition significantly altered the wheat grain quality under both [CO2] levels (depending on the soil water level), while also decreasing the grain yield.
- Authors: Fernando, Nimesha , Florentine, Singarayer , Naiker, Mani , Panozzo, Joe , Chauhan, Bhagirath
- Date: 2019
- Type: Text , Journal article
- Relation: Food Chemistry Vol. 276, no. (2019), p. 285-290
- Full Text:
- Reviewed:
- Description: Annual ryegrass is one of the most serious, costly weeds of winter cropping systems in Australia. To determine whether its competition-mediated plant defence mechanisms effect on wheat grain quality, wheat (cv. Yitpi) and annual ryegrass were grown under two levels of CO2 (400 ppm; (a[CO2]) vs 700 ppm; (e[CO2]), two levels of water (well-watered vs drought) and two types of competition (wheat only; (W), and wheatxannual ryegrass; (W x R) with four replicates. The competitionx[CO2] interaction had a significant effect on wheat grain protein content, where it was increased in W x R under both e[CO2] (+ 17%) and a[CO2] (+ 21%). Grain yield, total grain reducing power and phenolic content were significantly affected by [CO2] x drought x competition. In a summary, annual ryegrass competition significantly altered the wheat grain quality under both [CO2] levels (depending on the soil water level), while also decreasing the grain yield.
Autonomous adaptation to climate-driven change in marine biodiversity in a global marine hotspot
- Pecl, Gretta, Ogier, Emily, Jennings, Sarah, van Putten, Ingrid, Crawford, Christine, Fogarty, Hannah, Frusher, Stewart, Hobday, Alistair, Keane, John, Lee, Emma, MacLeod, Catriona, Mundy, Craig, Stuart-Smith, Jemima, Tracey, Sean
- Authors: Pecl, Gretta , Ogier, Emily , Jennings, Sarah , van Putten, Ingrid , Crawford, Christine , Fogarty, Hannah , Frusher, Stewart , Hobday, Alistair , Keane, John , Lee, Emma , MacLeod, Catriona , Mundy, Craig , Stuart-Smith, Jemima , Tracey, Sean
- Date: 2019
- Type: Text , Journal article
- Relation: Ambio Vol. 48, no. 12 (2019), p. 1498-1515
- Full Text:
- Reviewed:
- Description: While governments and natural resource managers grapple with how to respond to climatic changes, many marine-dependent individuals, organisations and user-groups in fast-changing regions of the world are already adjusting their behaviour to accommodate these. However, we have little information on the nature of these autonomous adaptations that are being initiated by resource user-groups. The east coast of Tasmania, Australia, is one of the world’s fastest warming marine regions with extensive climate-driven changes in biodiversity already observed. We present and compare examples of autonomous adaptations from marine users of the region to provide insights into factors that may have constrained or facilitated the available range of autonomous adaptation options and discuss potential interactions with governmental planned adaptations. We aim to support effective adaptation by identifying the suite of changes that marine users are making largely without government or management intervention, i.e. autonomous adaptations, to better understand these and their potential interactions with formal adaptation strategies. © 2019, Royal Swedish Academy of Sciences.
- Authors: Pecl, Gretta , Ogier, Emily , Jennings, Sarah , van Putten, Ingrid , Crawford, Christine , Fogarty, Hannah , Frusher, Stewart , Hobday, Alistair , Keane, John , Lee, Emma , MacLeod, Catriona , Mundy, Craig , Stuart-Smith, Jemima , Tracey, Sean
- Date: 2019
- Type: Text , Journal article
- Relation: Ambio Vol. 48, no. 12 (2019), p. 1498-1515
- Full Text:
- Reviewed:
- Description: While governments and natural resource managers grapple with how to respond to climatic changes, many marine-dependent individuals, organisations and user-groups in fast-changing regions of the world are already adjusting their behaviour to accommodate these. However, we have little information on the nature of these autonomous adaptations that are being initiated by resource user-groups. The east coast of Tasmania, Australia, is one of the world’s fastest warming marine regions with extensive climate-driven changes in biodiversity already observed. We present and compare examples of autonomous adaptations from marine users of the region to provide insights into factors that may have constrained or facilitated the available range of autonomous adaptation options and discuss potential interactions with governmental planned adaptations. We aim to support effective adaptation by identifying the suite of changes that marine users are making largely without government or management intervention, i.e. autonomous adaptations, to better understand these and their potential interactions with formal adaptation strategies. © 2019, Royal Swedish Academy of Sciences.
Balancing cost, performance and risk in maintenance and capital expenditure
- Authors: Chattopadhyay Gopi
- Date: 2019
- Type: Text , Journal article
- Relation: IAPQR Transactions Vol. 44, no. 2 (2019), p. 107-126
- Full Text: false
- Reviewed:
- Description: Asset Management is focused on realisation of value from assets through managing risk and opportunity. ISO standard for asset management ISO55000, 2014 stipulates effective control and governance of assets for desired balancing act of cost, performance and risk. This paper aims to study the maintenance and capital expenditure problems. It proposes how to balance cost, performance and risk for asset management. Decisions need to be based on performance and risk in addition to costs based on whole of life are supported by international standards for asset management. Option analysis and informed decision-making are proposed considering life cycle costs. Recent trend with industries is to align with latest international standards for asset management. Asset management in heavy haul rail network focuses on this by realisation of value from assets through managing risk and opportunity. Model for total cost of maintenance was developed covering risk costs associated with undetected surface/ subsurface cracks causing rail breaks and derailments and wear loss due to gauge face lubrication problems and intervention costs in inspections and interventions using progressive rail grinding and solar powered electric lubricators with remote performance monitoring. Illustrative examples are used to show how actions in inspection and subsequent rail grinding for controlling rolling contact fatigue (RCF) along with gauge face lubrication for controlling wear can be achieved in heavy haul railway. This maintenance and capital investment policy and decisions based on life cycle cost models can be used as reference for capital expenditure (capex) and operational expenditure (opex) balancing in any industry in general and heavy haul in particular.
Belief in conspiracy theories : the predictive role of schizotypy, machiavellianism, and primary psychopathy
- Authors: March, Evita , Springer
- Date: 2019
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 14, no. 12 (2019), p.
- Full Text:
- Reviewed:
- Description: A conspiracy theory refers to an alternative explanation of an event involving a conspirator plot organised by powerful people or organisations. Belief in conspiracy theories is related to negative societal outcomes such as poor medical decisions and a decrease in prosocial behaviour. Given these negative outcomes, researchers have explored predictors of belief in conspiracy theories in an attempt to understand and possibly manage these beliefs. In the current study, we explored the utility of personality in predicting belief in conspiracy theories. The aim of the current study was to explore the utility of the odd beliefs/magical thinking subtype of schizotypy, Machiavellianism, grandiose narcissism, vulnerable narcissism, primary psychopathy, and secondary psychopathy in predicting belief in conspiracy theories. Participants (N = 230; 44.7% male, 55.3% female) completed an anonymous, confidential online questionnaire which comprised demographics and measures of personality traits and belief in conspiracy theories. The total regression model indicated odd beliefs/magical thinking, trait Machiavellianism, and primary psychopathy were significant, positive predictors of belief in conspiracy theories. No other predictors reached significance. Results of the current study highlight individuals who might be more susceptible to believing conspiracy theories. Specifically, these results indicate that the individual more likely to believe in conspiracy theories may have unusual patterns of thinking and cognitions, be strategic and manipulative, and display interpersonal and affective deficits. © 2019 March, Springer. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
- Authors: March, Evita , Springer
- Date: 2019
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 14, no. 12 (2019), p.
- Full Text:
- Reviewed:
- Description: A conspiracy theory refers to an alternative explanation of an event involving a conspirator plot organised by powerful people or organisations. Belief in conspiracy theories is related to negative societal outcomes such as poor medical decisions and a decrease in prosocial behaviour. Given these negative outcomes, researchers have explored predictors of belief in conspiracy theories in an attempt to understand and possibly manage these beliefs. In the current study, we explored the utility of personality in predicting belief in conspiracy theories. The aim of the current study was to explore the utility of the odd beliefs/magical thinking subtype of schizotypy, Machiavellianism, grandiose narcissism, vulnerable narcissism, primary psychopathy, and secondary psychopathy in predicting belief in conspiracy theories. Participants (N = 230; 44.7% male, 55.3% female) completed an anonymous, confidential online questionnaire which comprised demographics and measures of personality traits and belief in conspiracy theories. The total regression model indicated odd beliefs/magical thinking, trait Machiavellianism, and primary psychopathy were significant, positive predictors of belief in conspiracy theories. No other predictors reached significance. Results of the current study highlight individuals who might be more susceptible to believing conspiracy theories. Specifically, these results indicate that the individual more likely to believe in conspiracy theories may have unusual patterns of thinking and cognitions, be strategic and manipulative, and display interpersonal and affective deficits. © 2019 March, Springer. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Causation analysis of risk coupling of gas explosion accident in chinese underground coal mines
- Zhang, Jinjia, Xu, Kaili, You, Greg, Wang, Beibei, Zhao, Lei
- Authors: Zhang, Jinjia , Xu, Kaili , You, Greg , Wang, Beibei , Zhao, Lei
- Date: 2019
- Type: Text , Journal article
- Relation: Risk Analysis Vol. 39, no. 7 (2019), p. 1634-1646
- Full Text: false
- Reviewed:
- Description: The coal mine production industry is a complex sociotechnical system with interactive relationships among several risk factors. Currently, causation analysis of gas explosion accidents is mainly focused on the aspects of human error and equipment fault, while neglecting the interactive relationships among risk factors. A new method is proposed through risk coupling. First, the meaning of risk coupling of a gas explosion is defined, and types of risk coupling are classified. Next, the coupled relationship and coupled effects among risk factors are explored through combining the interpretative structural modeling (ISM) and the NK model. Twenty-eight representative risk factors and 16 coupled types of risk factors are obtained through analysis of 332 gas explosion accidents in coal mines in China. Through the application of the combined ISM-NK model, an eight-level hierarchical model of risk coupling of a gas explosion accident is established, and the coupled degrees of different types of risk coupling are assessed. The hierarchical model reveals that two of the 28 risk factors, such as state policies, laws, and regulations, are the root risk factors for gas explosions; nine of the 28 risk factors, such as flame from blasting, electric spark, and local gas accumulation, are direct causes of gas explosions; whereas 17 of the risk factors, such as three-violation actions, ventilation system, and safety management, are indirect ones. A quantitative analysis of the NK model shows that the probability of gas explosion increases with the increasing number of risk factors. Compared with subjective risk factors, objective risk factors have a higher probability of causing gas explosion because of risk coupling.
- Oatley, Giles, Williams, Stephen, Barnes, Geoffrey, Clare, Joseph, Chapman, Brendan
- Authors: Oatley, Giles , Williams, Stephen , Barnes, Geoffrey , Clare, Joseph , Chapman, Brendan
- Date: 2019
- Type: Text , Journal article
- Relation: Australian Journal of Forensic Sciences Vol. 51, no. sup1 (2019), p. S136-S140
- Full Text: false
- Reviewed:
- Description: In an applied criminology context, recent meta-analyses and randomized control trials have demonstrated the benefits of targeting police patrols at hot spots or concentrations of street level crime and disorder. This study asked a group of 79 police officers from Perth to make a prediction, based on their experience, of where hot spots of crime would occur in the near future. Officer-defined hot spots were then compared with hot spots derived from police crime data over the preceding 24 month period. Finally, officer patrol time was tracked using a GPS-enabled smart phone and overlayed against both types of hot spot. This analysis indicates that police officers should be supported with hot spot mapping tools which identify data derived micro-places with persistent issues. Analysis also reveals officers patrol both their own and data-derived hot spots regularly; however, they only stay for a matter of a few minutes. These short stays are contrary to best evidence, which dictates officer patrols in hot spots should last for approximately 15 minutes in order to create both initial and residual deterrence.
DNA barcoding and integrative taxonomy of the heterolepisma sclerophylla species complex (Zygentoma: Lepismatidae: Heterolepismatinae) and the description of two new species
- Smith, Graeme, Mitchell, Andrew, Lee, Timothy, Espinasa, Luis
- Authors: Smith, Graeme , Mitchell, Andrew , Lee, Timothy , Espinasa, Luis
- Date: 2019
- Type: Text , Journal article
- Relation: Records of the Australian Museum Vol. 71, no. 1 (2019), p. 1-32
- Full Text:
- Reviewed:
- Description: We present one of the first studies of DNA barcodes (COI sequences) in the basal insect order Zygentoma, and compare the data with nuclear (28S) and mitochondrial (16S) rDNA sequences and morphology for an integrative taxonomic study of the Heterolepisma sclerophylla Smith species group. DNA sequence analyses identified deep divisions between Queensland and New South Wales populations, and among populations in each state. Detailed morphological and morphometric evaluation of the specimens failed, in most cases, to identify unambiguous morphological characters of diagnostic value for each population, possibly due to the interaction of morphological conservatism with high levels of variability resulting from their continued moulting after reaching sexual maturity. Several strong consistent characters were identified to support the description of a southern Queensland population as a new species (Heterolepisma cooloola sp. nov.). The combined molecular and morphological data support the view that the presence of lanceolate scales and the absence of macrochaetae from the anterior margin of the frons are more significant to phylogeny than the arrangement of styli and the shape of the thoracic sternites in Heterolepisma. Specimens from Glen Davis, NSW, while indistinguishable from H. sclerophylla in all other characters examined, were found to possess one fewer pair of abdominal styli in both sexes and are also described as a new species (Heterolepisma coorongooba sp. nov.). Five lineages are recognized within the remaining NSW material but as reliable (non-overlapping) morphological and morphometric differences could not be identified, they are not described here as new species. Heterolepisma sclerophylla sensu stricto is considered to be a complex of morphologically ill-defined species or perhaps subspecies.
- Authors: Smith, Graeme , Mitchell, Andrew , Lee, Timothy , Espinasa, Luis
- Date: 2019
- Type: Text , Journal article
- Relation: Records of the Australian Museum Vol. 71, no. 1 (2019), p. 1-32
- Full Text:
- Reviewed:
- Description: We present one of the first studies of DNA barcodes (COI sequences) in the basal insect order Zygentoma, and compare the data with nuclear (28S) and mitochondrial (16S) rDNA sequences and morphology for an integrative taxonomic study of the Heterolepisma sclerophylla Smith species group. DNA sequence analyses identified deep divisions between Queensland and New South Wales populations, and among populations in each state. Detailed morphological and morphometric evaluation of the specimens failed, in most cases, to identify unambiguous morphological characters of diagnostic value for each population, possibly due to the interaction of morphological conservatism with high levels of variability resulting from their continued moulting after reaching sexual maturity. Several strong consistent characters were identified to support the description of a southern Queensland population as a new species (Heterolepisma cooloola sp. nov.). The combined molecular and morphological data support the view that the presence of lanceolate scales and the absence of macrochaetae from the anterior margin of the frons are more significant to phylogeny than the arrangement of styli and the shape of the thoracic sternites in Heterolepisma. Specimens from Glen Davis, NSW, while indistinguishable from H. sclerophylla in all other characters examined, were found to possess one fewer pair of abdominal styli in both sexes and are also described as a new species (Heterolepisma coorongooba sp. nov.). Five lineages are recognized within the remaining NSW material but as reliable (non-overlapping) morphological and morphometric differences could not be identified, they are not described here as new species. Heterolepisma sclerophylla sensu stricto is considered to be a complex of morphologically ill-defined species or perhaps subspecies.
How practitioners integrate decision triggers with existing metrics in conservation monitoring
- Foster, Claire, O'Loughlin, Luke, Sato, Chloe, Westgate, Martin, Barton, Philip
- Authors: Foster, Claire , O'Loughlin, Luke , Sato, Chloe , Westgate, Martin , Barton, Philip
- Date: 2019
- Type: Text , Journal article
- Relation: Journal of Environmental Management Vol. 230, no. (2019), p. 94-101
- Full Text:
- Reviewed:
- Description: Decision triggers are defined thresholds in the status of monitored variables that indicate when to undertake management, and avoid undesirable ecosystem change. Decision triggers are frequently recommended to conservation practitioners as a tool to facilitate evidence-based management practices, but there has been limited attention paid to how practitioners are integrating decision triggers into existing monitoring programs. We sought to understand whether conservation practitioners’ use of decision triggers was influenced by the type of variables in their monitoring programs. We investigated this question using a practitioner-focused workshop involving a structured discussion and review of eight monitoring programs. Among our case studies, direct measures of biodiversity (e.g. native species) were more commonly monitored, but less likely to be linked to decision triggers (10% with triggers) than measures being used as surrogates (54% with triggers) for program objectives. This was because decision triggers were associated with management of threatening processes, which were often monitored as a surrogate for a biodiversity asset of interest. By contrast, direct measures of biodiversity were more commonly associated with informal decision processes that led to activities such as management reviews or external consultation. Workshop participants were in favor of including more formalized decision triggers in their programs, but were limited by incomplete ecological knowledge, lack of appropriately skilled staff, funding constraints, and/or uncertainty regarding intervention effectiveness. We recommend that practitioners consider including decision triggers for discussion activities (such as external consultation) in their programs as more than just early warning points for future interventions, particularly for direct measures. Decision triggers for discussions should be recognized as a critical feature of monitoring programs where information and operational limitations inhibit the use of decision triggers for interventions. © 2018 Elsevier Ltd. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Philip Barton” is provided in this record**
- Authors: Foster, Claire , O'Loughlin, Luke , Sato, Chloe , Westgate, Martin , Barton, Philip
- Date: 2019
- Type: Text , Journal article
- Relation: Journal of Environmental Management Vol. 230, no. (2019), p. 94-101
- Full Text:
- Reviewed:
- Description: Decision triggers are defined thresholds in the status of monitored variables that indicate when to undertake management, and avoid undesirable ecosystem change. Decision triggers are frequently recommended to conservation practitioners as a tool to facilitate evidence-based management practices, but there has been limited attention paid to how practitioners are integrating decision triggers into existing monitoring programs. We sought to understand whether conservation practitioners’ use of decision triggers was influenced by the type of variables in their monitoring programs. We investigated this question using a practitioner-focused workshop involving a structured discussion and review of eight monitoring programs. Among our case studies, direct measures of biodiversity (e.g. native species) were more commonly monitored, but less likely to be linked to decision triggers (10% with triggers) than measures being used as surrogates (54% with triggers) for program objectives. This was because decision triggers were associated with management of threatening processes, which were often monitored as a surrogate for a biodiversity asset of interest. By contrast, direct measures of biodiversity were more commonly associated with informal decision processes that led to activities such as management reviews or external consultation. Workshop participants were in favor of including more formalized decision triggers in their programs, but were limited by incomplete ecological knowledge, lack of appropriately skilled staff, funding constraints, and/or uncertainty regarding intervention effectiveness. We recommend that practitioners consider including decision triggers for discussion activities (such as external consultation) in their programs as more than just early warning points for future interventions, particularly for direct measures. Decision triggers for discussions should be recognized as a critical feature of monitoring programs where information and operational limitations inhibit the use of decision triggers for interventions. © 2018 Elsevier Ltd. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Philip Barton” is provided in this record**
Influence of soil moisture regimes on growth, photosynthetic capacity, leaf biochemistry and reproductive capabilities of the invasive agronomic weed; Lactuca serriola
- Chadha, Aakansha, Florentine, Singarayer, Chauhan, Bhagirath, Long, Benjamin, Jayasundera, Mithila
- Authors: Chadha, Aakansha , Florentine, Singarayer , Chauhan, Bhagirath , Long, Benjamin , Jayasundera, Mithila
- Date: 2019
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 14, no. 6 (2019), p. 1-17
- Full Text:
- Reviewed:
- Description: Global temperatures are predicted to increase by 1.5–5.9C during this century, and this change is likely to impact average rainfall, with predictions that water deficit will perhaps be the most severe threat to sustainable agriculture. In this respect, invasive weeds, which have traits better adapted to drought stress than crops, add to concerns regarding crop sustainability. Lactuca serriola, an aggressive agronomic weed is thought to be a successful weed because of its ability to maintain high water use efficiency under drought conditions. In this study, experiments were conducted to examine the influence of different soil moisture regimes (100%, 75%, 50% and 25% water holding capacity (WHC)) on growth, photosynthetic capacity, leaf biochemistry and reproduction of this species. Soil moisture significantly affected plant’s height, stem diameter, number of leaves and biomass. The highest plant height (115.14 cm ± 11.64), shoot diameter (9.4 mm ± 0.18), leaf area (1206.5 mm2 ± 73.29), plant fresh weight (83.1 ± 3.98) and dry weight (22.38 ± 1.24) were recorded at 75% soil moisture content. A fundamental adaptation to drought was observed as plants in the 25% WHC treatment had the highest root: shoot ratio. Soluble sugars and total phenolic content were highest in the 25% WHC treatment and significantly different to 100% WHC which was a response to soil moisture stress to ameliorate the damaging effects of reactive oxygen species produced under stress conditions. Results also indicate that L. serriola can survive and produce seeds under water stress as more than 6000 seeds were produced per plant in all WHC treatments. In this study, there was no significant difference in the seed weight, number of seeds produced and their germination ability. This can have a huge impact on agricultural systems as the species can survive both under low and high soil moisture conditions. We therefore suggest that the demonstrated ability of L. serriola to complete its life cycle and produce biomass and seeds under water stressed conditions leads to the introduction of strategies that minimize weed survival while maximizing irrigation efficiency for the crop. A clear understanding of the ecological and biological characteristics of this weed will help land managers take appropriate control measures to mitigate the effect of this species on economic crop productivity.
- Authors: Chadha, Aakansha , Florentine, Singarayer , Chauhan, Bhagirath , Long, Benjamin , Jayasundera, Mithila
- Date: 2019
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 14, no. 6 (2019), p. 1-17
- Full Text:
- Reviewed:
- Description: Global temperatures are predicted to increase by 1.5–5.9C during this century, and this change is likely to impact average rainfall, with predictions that water deficit will perhaps be the most severe threat to sustainable agriculture. In this respect, invasive weeds, which have traits better adapted to drought stress than crops, add to concerns regarding crop sustainability. Lactuca serriola, an aggressive agronomic weed is thought to be a successful weed because of its ability to maintain high water use efficiency under drought conditions. In this study, experiments were conducted to examine the influence of different soil moisture regimes (100%, 75%, 50% and 25% water holding capacity (WHC)) on growth, photosynthetic capacity, leaf biochemistry and reproduction of this species. Soil moisture significantly affected plant’s height, stem diameter, number of leaves and biomass. The highest plant height (115.14 cm ± 11.64), shoot diameter (9.4 mm ± 0.18), leaf area (1206.5 mm2 ± 73.29), plant fresh weight (83.1 ± 3.98) and dry weight (22.38 ± 1.24) were recorded at 75% soil moisture content. A fundamental adaptation to drought was observed as plants in the 25% WHC treatment had the highest root: shoot ratio. Soluble sugars and total phenolic content were highest in the 25% WHC treatment and significantly different to 100% WHC which was a response to soil moisture stress to ameliorate the damaging effects of reactive oxygen species produced under stress conditions. Results also indicate that L. serriola can survive and produce seeds under water stress as more than 6000 seeds were produced per plant in all WHC treatments. In this study, there was no significant difference in the seed weight, number of seeds produced and their germination ability. This can have a huge impact on agricultural systems as the species can survive both under low and high soil moisture conditions. We therefore suggest that the demonstrated ability of L. serriola to complete its life cycle and produce biomass and seeds under water stressed conditions leads to the introduction of strategies that minimize weed survival while maximizing irrigation efficiency for the crop. A clear understanding of the ecological and biological characteristics of this weed will help land managers take appropriate control measures to mitigate the effect of this species on economic crop productivity.
Leaders' creation of shared identity impacts group members' effort and performance : evidence from an exercise task
- Stevens, Mark, Rees, Tim, Steffens, Niklas, Haslam, S., Coffee, Pete, Polman, Remco
- Authors: Stevens, Mark , Rees, Tim , Steffens, Niklas , Haslam, S. , Coffee, Pete , Polman, Remco
- Date: 2019
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 14, no. 7 (2019), p.
- Full Text:
- Reviewed:
- Description: There is growing evidence that leaders' effectiveness derives in part from their creation of a sense of identity that is shared by members of a group they are attempting to lead (i.e., their identity entrepreneurship). Little is known, however, about the impact of identity entrepreneurship in sport and exercise settings, particularly in relation to its effect on group members' effort and performance. Using a pre-post between subjects experimental design, we examined the effect of leaders' identity entrepreneurship on group members' effort and performance during 5km cycling time trials. Following a baseline session (in which time trials were completed individually), participants (N = 72) were randomly allocated to either a high or low identity entrepreneurship condition, and further randomly divided into groups of five (including a leader who was a confederate). In the subsequent test sessions (which participants attended with their fellow group members), leaders displayed either high or low identity entrepreneurship behaviors. Results indicated that, compared to participants in the low identity entrepreneurship condition, those in the high identity entrepreneurship condition maintained greater effort (maximum heart rate), and demonstrated improved (rather than poorer) performance (average power output in the first 60 seconds of time trials). Examination of pacing showed that the largest increases in participants' average power output occurred in the early stages of their second time trials for those in the high identity entrepreneurship condition only. Results provide causal evidence that leaders who create a shared sense of identity among team members are able to inspire greater participant effort and performance. © 2019 Stevens et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
- Authors: Stevens, Mark , Rees, Tim , Steffens, Niklas , Haslam, S. , Coffee, Pete , Polman, Remco
- Date: 2019
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 14, no. 7 (2019), p.
- Full Text:
- Reviewed:
- Description: There is growing evidence that leaders' effectiveness derives in part from their creation of a sense of identity that is shared by members of a group they are attempting to lead (i.e., their identity entrepreneurship). Little is known, however, about the impact of identity entrepreneurship in sport and exercise settings, particularly in relation to its effect on group members' effort and performance. Using a pre-post between subjects experimental design, we examined the effect of leaders' identity entrepreneurship on group members' effort and performance during 5km cycling time trials. Following a baseline session (in which time trials were completed individually), participants (N = 72) were randomly allocated to either a high or low identity entrepreneurship condition, and further randomly divided into groups of five (including a leader who was a confederate). In the subsequent test sessions (which participants attended with their fellow group members), leaders displayed either high or low identity entrepreneurship behaviors. Results indicated that, compared to participants in the low identity entrepreneurship condition, those in the high identity entrepreneurship condition maintained greater effort (maximum heart rate), and demonstrated improved (rather than poorer) performance (average power output in the first 60 seconds of time trials). Examination of pacing showed that the largest increases in participants' average power output occurred in the early stages of their second time trials for those in the high identity entrepreneurship condition only. Results provide causal evidence that leaders who create a shared sense of identity among team members are able to inspire greater participant effort and performance. © 2019 Stevens et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Lower dormancy with rapid germination is an important strategy for seeds in an arid zone with unpredictable rainfall
- Duncan, Corrine, Schultz, Nick, Lewandrowski, Wolfgang, Good, Megan, Cook, Simon
- Authors: Duncan, Corrine , Schultz, Nick , Lewandrowski, Wolfgang , Good, Megan , Cook, Simon
- Date: 2019
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 14, no. 9 (2019), p.
- Full Text:
- Reviewed:
- Description: Seed germination traits are key drivers of population dynamics, yet they are under-represented in community ecology studies, which have predominately focussed on adult plant and seed morphological traits. We studied the seed traits and germination strategy of eight woody plant species to investigate regeneration strategies in the arid zone of eastern Australia. To cope with stochastic and minimal rainfall, we predict that arid seeds will either have rapid germination across a wide range of temperatures, improved germination under cooler temperatures, or dormancy and/or longevity traits to delay or stagger germination across time. To understand how temperature affects germination responses, seeds of eight keystone arid species were germinated under laboratory conditions, and under three diurnal temperatures (30/20°C, 25/15°C and 17/7°C) for 30 days. We also tested for decline in seed viability across 24 months in a dry-aging treatment (
- Authors: Duncan, Corrine , Schultz, Nick , Lewandrowski, Wolfgang , Good, Megan , Cook, Simon
- Date: 2019
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 14, no. 9 (2019), p.
- Full Text:
- Reviewed:
- Description: Seed germination traits are key drivers of population dynamics, yet they are under-represented in community ecology studies, which have predominately focussed on adult plant and seed morphological traits. We studied the seed traits and germination strategy of eight woody plant species to investigate regeneration strategies in the arid zone of eastern Australia. To cope with stochastic and minimal rainfall, we predict that arid seeds will either have rapid germination across a wide range of temperatures, improved germination under cooler temperatures, or dormancy and/or longevity traits to delay or stagger germination across time. To understand how temperature affects germination responses, seeds of eight keystone arid species were germinated under laboratory conditions, and under three diurnal temperatures (30/20°C, 25/15°C and 17/7°C) for 30 days. We also tested for decline in seed viability across 24 months in a dry-aging treatment (
Managing uncertainty in movement knowledge for environmental decisions
- Smith, Annabel, Kujala, Heini, Lahoz-Monfort, José, Guja, Lydia, Barton, Philip
- Authors: Smith, Annabel , Kujala, Heini , Lahoz-Monfort, José , Guja, Lydia , Barton, Philip
- Date: 2019
- Type: Text , Journal article
- Relation: Conservation Letters Vol. 12, no. 3 (2019), p.
- Full Text:
- Reviewed:
- Description: Species’ movements affect their response to environmental change but movement knowledge is often highly uncertain. We now have well-established methods to inte-grate movement knowledge into conservation practice but still lack a framework to deal with uncertainty in movement knowledge for environmental decisions. We provide a framework that distinguishes two dimensions of species’ movement that are heavily influenced by uncertainty: knowledge about movement and relevance of movement to environmental decisions. Management decisions can be informed by their position in this knowledge-relevance space. We then outline a framework to support decisions around (1) increasing understanding of the relevance of movement knowledge, (2) increasing robustness of decisions to uncertainties and (3) improving knowledge on species’ movement. Our decision-support framework provides guid-ance for managing movement-related uncertainty in systematic conservation plan-ning, agri-environment schemes, habitat restoration and international biodiversity policy. It caters to different resource levels (time and funding) so that species’ movement knowledge can be more effectively integrated into environmental decisions. © 2018 The Authors. Conservation Letters published by Wiley Periodicals, Inc.
- Authors: Smith, Annabel , Kujala, Heini , Lahoz-Monfort, José , Guja, Lydia , Barton, Philip
- Date: 2019
- Type: Text , Journal article
- Relation: Conservation Letters Vol. 12, no. 3 (2019), p.
- Full Text:
- Reviewed:
- Description: Species’ movements affect their response to environmental change but movement knowledge is often highly uncertain. We now have well-established methods to inte-grate movement knowledge into conservation practice but still lack a framework to deal with uncertainty in movement knowledge for environmental decisions. We provide a framework that distinguishes two dimensions of species’ movement that are heavily influenced by uncertainty: knowledge about movement and relevance of movement to environmental decisions. Management decisions can be informed by their position in this knowledge-relevance space. We then outline a framework to support decisions around (1) increasing understanding of the relevance of movement knowledge, (2) increasing robustness of decisions to uncertainties and (3) improving knowledge on species’ movement. Our decision-support framework provides guid-ance for managing movement-related uncertainty in systematic conservation plan-ning, agri-environment schemes, habitat restoration and international biodiversity policy. It caters to different resource levels (time and funding) so that species’ movement knowledge can be more effectively integrated into environmental decisions. © 2018 The Authors. Conservation Letters published by Wiley Periodicals, Inc.
- Jiang, Shou-yan, Du, Chengbin, Ooi, Ean
- Authors: Jiang, Shou-yan , Du, Chengbin , Ooi, Ean
- Date: 2019
- Type: Text , Journal article
- Relation: Engineering Fracture Mechanics Vol. 222, no. (Dec 2019), p. 25
- Full Text: false
- Reviewed:
- Description: In this paper, a technique to model strong and weak discontinuities with the scaled boundary finite element method through enrichment is proposed. The main advantage of the method is that the enriched elements, in the spirit of the extended finite element method (XFEM), do not need to physically conform to the geometry of features, e.g. internal interfaces and cracks, and remeshing is unnecessary as the interfaces evolve. All the advantages of the SBFEM and the XFEM are retained. The stress singularity at the crack tip can be captured accurately and the stress intensity factors (SIFs) can be directly computed based on the singular displacement or stress at the crack tip within the framework of the SBFEM. The numerical properties and performance for the proposed method are assessed using several numerical examples. In particular, problems with discontinuities, e.g. voids, inclusions, and cracks are analysed. The results show that the accuracy and convergence rate of the new approach for solving void or inclusion problems are identical to those of the XFEM, but requires less number of degrees-of-freedom than the XFEM. For crack problems, compared with the XFEM with topological enrichment, the developed method is superior.
National income inequality predicts cultural variation in mouth to mouth kissing
- Watkins, Christopher, Leongómez, Juan, Bovet, Jeanne, Żelaźniewicz, Agnieszka, Korbmacher, Max, Varella, Marco, Fernandez, Ana, Wagstaff, Danielle, Bolgan, Samuela
- Authors: Watkins, Christopher , Leongómez, Juan , Bovet, Jeanne , Żelaźniewicz, Agnieszka , Korbmacher, Max , Varella, Marco , Fernandez, Ana , Wagstaff, Danielle , Bolgan, Samuela
- Date: 2019
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 9, no. 1 (2019), p. 1-9
- Full Text:
- Reviewed:
- Description: Romantic mouth-to-mouth kissing is culturally widespread, although not a human universal, and may play a functional role in assessing partner health and maintaining long-term pair bonds. Use and appreciation of kissing may therefore vary according to whether the environment places a premium on good health and partner investment. Here, we test for cultural variation (13 countries from six continents) in these behaviours/attitudes according to national health (historical pathogen prevalence) and both absolute (GDP) and relative wealth (GINI). Our data reveal that kissing is valued more in established relationships than it is valued during courtship. Also, consistent with the pair bonding hypothesis of the function of romantic kissing, relative poverty (income inequality) predicts frequency of kissing across romantic relationships. When aggregated, the predicted relationship between income inequality and kissing frequency (r = 0.67, BCa 95% CI[0.32,0.89]) was over five times the size of the null correlations between income inequality and frequency of hugging/cuddling and sex. As social complexity requires monitoring resource competition among large groups and predicts kissing prevalence in remote societies, this gesture may be important in the maintenance of long-term pair bonds in specific environments.
- Authors: Watkins, Christopher , Leongómez, Juan , Bovet, Jeanne , Żelaźniewicz, Agnieszka , Korbmacher, Max , Varella, Marco , Fernandez, Ana , Wagstaff, Danielle , Bolgan, Samuela
- Date: 2019
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 9, no. 1 (2019), p. 1-9
- Full Text:
- Reviewed:
- Description: Romantic mouth-to-mouth kissing is culturally widespread, although not a human universal, and may play a functional role in assessing partner health and maintaining long-term pair bonds. Use and appreciation of kissing may therefore vary according to whether the environment places a premium on good health and partner investment. Here, we test for cultural variation (13 countries from six continents) in these behaviours/attitudes according to national health (historical pathogen prevalence) and both absolute (GDP) and relative wealth (GINI). Our data reveal that kissing is valued more in established relationships than it is valued during courtship. Also, consistent with the pair bonding hypothesis of the function of romantic kissing, relative poverty (income inequality) predicts frequency of kissing across romantic relationships. When aggregated, the predicted relationship between income inequality and kissing frequency (r = 0.67, BCa 95% CI[0.32,0.89]) was over five times the size of the null correlations between income inequality and frequency of hugging/cuddling and sex. As social complexity requires monitoring resource competition among large groups and predicts kissing prevalence in remote societies, this gesture may be important in the maintenance of long-term pair bonds in specific environments.
Response of Chloris truncata to moisture stress, elevated carbon dioxide and herbicide application
- Weller, Sandra, Florentine, Singarayer, Mutti, Navneet, Jha, Prashant, Chauhan, Bhagirath
- Authors: Weller, Sandra , Florentine, Singarayer , Mutti, Navneet , Jha, Prashant , Chauhan, Bhagirath
- Date: 2019
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 9, no. 1 (2019), p. 1-10
- Full Text:
- Reviewed:
- Description: Herbicide resistance has been observed in Chloris truncata, an Australian native C4 grass and a summer-fallow weed, which is common in no-till agriculture situations where herbicides are involved in crop management. To investigate the role of drought and increased atmospheric carbon dioxide (CO2) in determining weed growth, three trials were conducted using a ‘glyphosate-resistant’ and a ‘glyphosate-susceptible’ biotype. The first two trials tested the effect of herbicide (glyphosate) application on plant survival and growth under moisture stress and elevated CO2 respectively. A third trial investigated the effect on plant growth and reproduction under conditions of moisture stress and elevated CO2 in the absence of herbicide. In the first trial, water was withheld from half of the plants prior to application of glyphosate to all plants, and in the second trial plants were grown in either ambient (450 ppm) or elevated CO2 levels (750 ppm) prior to, and following, herbicide application. In both biotypes, herbicide effectiveness was reduced when plants were subjected to moisture stress or if grown in elevated CO2. Plant productivity, as measured by dry biomass per plant, was reduced with moisture stress, but increased with elevated CO2. In the third trial, growth rate, biomass and seed production were higher in the susceptible biotype compared to the resistant biotype. This suggests that a superior ability to resist herbicides may come at a cost to overall plant fitness. The results indicate that control of this weed may become difficult in the future as climatic conditions change. Supplementary information accompanies this paper at https://doi.org/10.1038/s41598-019-47237-x.
- Authors: Weller, Sandra , Florentine, Singarayer , Mutti, Navneet , Jha, Prashant , Chauhan, Bhagirath
- Date: 2019
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 9, no. 1 (2019), p. 1-10
- Full Text:
- Reviewed:
- Description: Herbicide resistance has been observed in Chloris truncata, an Australian native C4 grass and a summer-fallow weed, which is common in no-till agriculture situations where herbicides are involved in crop management. To investigate the role of drought and increased atmospheric carbon dioxide (CO2) in determining weed growth, three trials were conducted using a ‘glyphosate-resistant’ and a ‘glyphosate-susceptible’ biotype. The first two trials tested the effect of herbicide (glyphosate) application on plant survival and growth under moisture stress and elevated CO2 respectively. A third trial investigated the effect on plant growth and reproduction under conditions of moisture stress and elevated CO2 in the absence of herbicide. In the first trial, water was withheld from half of the plants prior to application of glyphosate to all plants, and in the second trial plants were grown in either ambient (450 ppm) or elevated CO2 levels (750 ppm) prior to, and following, herbicide application. In both biotypes, herbicide effectiveness was reduced when plants were subjected to moisture stress or if grown in elevated CO2. Plant productivity, as measured by dry biomass per plant, was reduced with moisture stress, but increased with elevated CO2. In the third trial, growth rate, biomass and seed production were higher in the susceptible biotype compared to the resistant biotype. This suggests that a superior ability to resist herbicides may come at a cost to overall plant fitness. The results indicate that control of this weed may become difficult in the future as climatic conditions change. Supplementary information accompanies this paper at https://doi.org/10.1038/s41598-019-47237-x.
Review of tropical cyclones in the Australian region : Climatology, variability, predictability, and trends
- Chand, Savin, Dowdy, Andrew, Ramsay, Hamish, Walsh, Kevin, Tory, Kevin, Power, Scott, Bell, Samuel, Lavender, Sally, Ye, Hua, Kuleshov, Yuri
- Authors: Chand, Savin , Dowdy, Andrew , Ramsay, Hamish , Walsh, Kevin , Tory, Kevin , Power, Scott , Bell, Samuel , Lavender, Sally , Ye, Hua , Kuleshov, Yuri
- Date: 2019
- Type: Text , Journal article , Review
- Relation: Wiley Interdisciplinary Reviews: Climate Change Vol. 10, no. 5 (2019), p. 1-17
- Full Text:
- Reviewed:
- Description: Tropical cyclones (TCs) can have severe impacts on Australia. These include extreme rainfall and winds, and coastal hazards such as destructive waves, storm surges, estuarine flooding, and coastal erosion. Various aspects of TCs in the Australian region have been documented over the past several decades. In recent years, increasing emphasis has been placed on human-induced climate change effects on TCs in the Australian region and elsewhere around the globe. However, large natural variability and the lack of consistent long-term TC observations have often complicated the detection and attribution of TC trends. Efforts have been made to improve TC records for Australia over the past decades, but it is still unclear whether such records are sufficient to provide better understanding of the impacts of natural climate variability and climate change. It is important to note that the damage costs associated with tropical cyclones in Australia have increased in recent decades and will continue to increase due to growing coastal settlement and infrastructure development. Therefore, it is critical that any coastal infrastructure planning and engineering decisions, as well as disaster management decisions, strongly consider future risks from tropical cyclones. A better understanding of tropical cyclones in a changing climate will provide key insights that can help mitigate impacts of tropical cyclones on vulnerable communities. An objective assessment of the Australian TCs at regional scale and its link with climate variability and change using improved and up-to-date data records is more imperative now than before. This article is categorized under: Paleoclimates and Current Trends > Modern Climate Change.
- Authors: Chand, Savin , Dowdy, Andrew , Ramsay, Hamish , Walsh, Kevin , Tory, Kevin , Power, Scott , Bell, Samuel , Lavender, Sally , Ye, Hua , Kuleshov, Yuri
- Date: 2019
- Type: Text , Journal article , Review
- Relation: Wiley Interdisciplinary Reviews: Climate Change Vol. 10, no. 5 (2019), p. 1-17
- Full Text:
- Reviewed:
- Description: Tropical cyclones (TCs) can have severe impacts on Australia. These include extreme rainfall and winds, and coastal hazards such as destructive waves, storm surges, estuarine flooding, and coastal erosion. Various aspects of TCs in the Australian region have been documented over the past several decades. In recent years, increasing emphasis has been placed on human-induced climate change effects on TCs in the Australian region and elsewhere around the globe. However, large natural variability and the lack of consistent long-term TC observations have often complicated the detection and attribution of TC trends. Efforts have been made to improve TC records for Australia over the past decades, but it is still unclear whether such records are sufficient to provide better understanding of the impacts of natural climate variability and climate change. It is important to note that the damage costs associated with tropical cyclones in Australia have increased in recent decades and will continue to increase due to growing coastal settlement and infrastructure development. Therefore, it is critical that any coastal infrastructure planning and engineering decisions, as well as disaster management decisions, strongly consider future risks from tropical cyclones. A better understanding of tropical cyclones in a changing climate will provide key insights that can help mitigate impacts of tropical cyclones on vulnerable communities. An objective assessment of the Australian TCs at regional scale and its link with climate variability and change using improved and up-to-date data records is more imperative now than before. This article is categorized under: Paleoclimates and Current Trends > Modern Climate Change.
Secure and efficient data delivery for fog-assisted wireless body area networks
- Hayajneh, Thaier, Griggs, Kristen, Imran, Muhammad, Mohd, Bassam
- Authors: Hayajneh, Thaier , Griggs, Kristen , Imran, Muhammad , Mohd, Bassam
- Date: 2019
- Type: Text , Journal article
- Relation: Peer-to-Peer Networking and Applications Vol. 12, no. 5 (2019), p. 1289-1307
- Full Text: false
- Reviewed:
- Description: The growth of remote patient monitoring technology introduces new opportunities for improving patient outcomes, and Wireless Body Area Networks (WBANs) are a key piece in building a successful system. However, due to the limited power and computational resources of WBAN sensor nodes, combined with user mobility and large network coverage areas, integrating WBANs with cloud and fog computing presents one of the most viable options for successful remote monitoring. In order to help maintain the real-time operations of a fog-assisted WBAN, we propose a secure and efficient data delivery protocol that will reduce delay and protect against malicious attacks on the wireless signal. The protocol is composed of three custom algorithms that address channel assignment, gateway association, and introduce a new delay- and energy-aware routing metric. The channel assignment algorithm is designed to minimize and avoid interference, including jamming nodes. The fog gateway association algorithm helps to improve the efficiency and security of the connection between the WBAN and the remote resources. Similarly, the proposed routing metric is used to construct routes that both minimize delay and conserve power at the nodes along the path for improved efficiency and lifespan of the network. The system was simulated and tested under a variety of conditions to evaluate its performance in regards to mutual interference, human mobility, fog density, and attacks by jamming nodes. The results showed clear improvements in the efficiency and resiliency of the fog-assisted WBAN system when utilizing our protocol. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.
Seed germination ecology of Bidens pilosa and its implications for weed management
- Chauhan, Bhagirath, Ali, Hafiz, Florentine, Singarayer
- Authors: Chauhan, Bhagirath , Ali, Hafiz , Florentine, Singarayer
- Date: 2019
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 9, no. 1 (2019), p.
- Full Text:
- Reviewed:
- Description: It is now widely recognized that Bidens pilosa has become a problematic broadleaf weed in many ecosystems across the world and, particularly in the light of recent climate change conditions, closer management strategies are required to curtail its impact on agricultural cropping. In this investigation, experiments were conducted to evaluate the effect of environmental factors on the germination and emergence of B. pilosa, and also on the response of this weed to commonly available post-emergence herbicides in Australia. The environmental factors of particular interest to this current work were the effect of light and temperature, salinity, burial depth and moisture on B. pilosa since these are key management issues in Australian agriculture. In addition, the effects of a number of commonly used herbicides were examined, because of concerns regarding emerging herbicide resistance. In the tested light/dark regimes, germination was found to be higher at fluctuating day/night temperatures of 25/15 °C and 30/20 °C (92–93%) than at 35/25 °C (79%), whilst across the different temperature ranges, germination was higher in the light/dark regime (79–93%) than in complete darkness (22–38%). The standard five-minute temperature pretreatment required for 50% inhibition of maximum germination was found to be 160 °C, and it was further shown that no seeds germinated at temperatures higher than 240 °C. With regard to salinity, some B. pilosa seeds germinated (3%) in 200 mM sodium chloride (NaCl) but all failed to germinate at 250 mM NaCl. Germination declined from 89% to 2% as the external osmotic potential decreased from 0 to −0.6 MPa, and germination ceased at −0.8 MPa. Seeding emergence of B. pilosa was maximum (71%) for seeds placed on the soil surface and it was found that no seedlings emerged from a depth of 8 cm or greater. A depth of 3.75 cm was required to inhibit the seeds to 50% of the maximum emergence. In this study, application of glufosinate, glyphosate and paraquat provided commercially acceptable control levels (generally accepted as >90%) when applied at the four-leaf stage of B. pilosa. However, none of the herbicide treatments involved in this study provided this level of control when applied at the six-leaf stage. In summary, B. pilosa germination has been clearly shown to be stimulated by light and thus its emergence was greatest from the soil surface. This suggests that infestation from this weed will remain as a problem in no-till conservation agriculture systems, the use of which is increasing now throughout the world. It is intended that information generated from this study be used to develop more effective integrated management programs for B. pilosa and similar weeds in commercial agricultural environments which are tending toward conservation approaches. © 2019, The Author(s).
- Authors: Chauhan, Bhagirath , Ali, Hafiz , Florentine, Singarayer
- Date: 2019
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 9, no. 1 (2019), p.
- Full Text:
- Reviewed:
- Description: It is now widely recognized that Bidens pilosa has become a problematic broadleaf weed in many ecosystems across the world and, particularly in the light of recent climate change conditions, closer management strategies are required to curtail its impact on agricultural cropping. In this investigation, experiments were conducted to evaluate the effect of environmental factors on the germination and emergence of B. pilosa, and also on the response of this weed to commonly available post-emergence herbicides in Australia. The environmental factors of particular interest to this current work were the effect of light and temperature, salinity, burial depth and moisture on B. pilosa since these are key management issues in Australian agriculture. In addition, the effects of a number of commonly used herbicides were examined, because of concerns regarding emerging herbicide resistance. In the tested light/dark regimes, germination was found to be higher at fluctuating day/night temperatures of 25/15 °C and 30/20 °C (92–93%) than at 35/25 °C (79%), whilst across the different temperature ranges, germination was higher in the light/dark regime (79–93%) than in complete darkness (22–38%). The standard five-minute temperature pretreatment required for 50% inhibition of maximum germination was found to be 160 °C, and it was further shown that no seeds germinated at temperatures higher than 240 °C. With regard to salinity, some B. pilosa seeds germinated (3%) in 200 mM sodium chloride (NaCl) but all failed to germinate at 250 mM NaCl. Germination declined from 89% to 2% as the external osmotic potential decreased from 0 to −0.6 MPa, and germination ceased at −0.8 MPa. Seeding emergence of B. pilosa was maximum (71%) for seeds placed on the soil surface and it was found that no seedlings emerged from a depth of 8 cm or greater. A depth of 3.75 cm was required to inhibit the seeds to 50% of the maximum emergence. In this study, application of glufosinate, glyphosate and paraquat provided commercially acceptable control levels (generally accepted as >90%) when applied at the four-leaf stage of B. pilosa. However, none of the herbicide treatments involved in this study provided this level of control when applied at the six-leaf stage. In summary, B. pilosa germination has been clearly shown to be stimulated by light and thus its emergence was greatest from the soil surface. This suggests that infestation from this weed will remain as a problem in no-till conservation agriculture systems, the use of which is increasing now throughout the world. It is intended that information generated from this study be used to develop more effective integrated management programs for B. pilosa and similar weeds in commercial agricultural environments which are tending toward conservation approaches. © 2019, The Author(s).
Singlet molecular oxygen regulates vascular tone and blood pressure in inflammation
- Stanley, Christopher, Maghzal, Ghassan, Ayer, Anita, Talib, Jihan, Giltrap, Andrew, Shengule, Sudhir, Wolhuter, Kathryn, Wang, Yutang, Chadha, Preet, Suarna, Cacang, Prysyazhna, Oleksandra, Scotcher, Jenna, Dunn, Louise, Prado, Fernanda, Nguyen, Nghi, Odiba, Jephthah, Baell, Johathan, Stasch, Johannes-Peter, Yamamoto, Yorihiro, Di Mascio, Paolo, Eaton, Philip, Payne, Richard, Stocker, Roland
- Authors: Stanley, Christopher , Maghzal, Ghassan , Ayer, Anita , Talib, Jihan , Giltrap, Andrew , Shengule, Sudhir , Wolhuter, Kathryn , Wang, Yutang , Chadha, Preet , Suarna, Cacang , Prysyazhna, Oleksandra , Scotcher, Jenna , Dunn, Louise , Prado, Fernanda , Nguyen, Nghi , Odiba, Jephthah , Baell, Johathan , Stasch, Johannes-Peter , Yamamoto, Yorihiro , Di Mascio, Paolo , Eaton, Philip , Payne, Richard , Stocker, Roland
- Date: 2019
- Type: Text , Journal article , Letter
- Relation: Nature Vol. 566, no. 7745 (2019), p. 548-552
- Full Text:
- Reviewed:
- Description: Singlet molecular oxygen (O-1(2)) has well-established roles in photosynthetic plants, bacteria and fungi(1-3), but not in mammals. Chemically generated O-1(2) oxidizes the amino acid tryptophan to precursors of a key metabolite called N-formylkynurenine(4), whereas enzymatic oxidation of tryptophan to N-formylkynurenine is catalysed by a family of dioxygenases, including indoleamine 2,3-dioxygenase 1(5). Under inflammatory conditions, this haem-containing enzyme is expressed in arterial endothelial cells, where it contributes to the regulation of blood pressure(6). However, whether indoleamine 2,3-dioxygenase 1 forms O-1(2) and whether this contributes to blood pressure control have remained unknown. Here we show that arterial indoleamine 2,3-dioxygenase 1 regulates blood pressure via formation of O-1(2). We observed that in the presence of hydrogen peroxide, the enzyme generates O-1(2) and that this is associated with the stereoselective oxidation of L-tryptophan to a tricyclic hydroperoxide via a previously unrecognized oxidative activation of the dioxygenase activity. The tryptophan-derived hydroperoxide acts in vivo as a signalling molecule, inducing arterial relaxation and decreasing blood pressure; this activity is dependent on Cys42 of protein kinase G1 alpha. Our findings demonstrate a pathophysiological role for O-1(2) in mammals through formation of an amino acid-derived hydroperoxide that regulates vascular tone and blood pressure under inflammatory conditions.
- Authors: Stanley, Christopher , Maghzal, Ghassan , Ayer, Anita , Talib, Jihan , Giltrap, Andrew , Shengule, Sudhir , Wolhuter, Kathryn , Wang, Yutang , Chadha, Preet , Suarna, Cacang , Prysyazhna, Oleksandra , Scotcher, Jenna , Dunn, Louise , Prado, Fernanda , Nguyen, Nghi , Odiba, Jephthah , Baell, Johathan , Stasch, Johannes-Peter , Yamamoto, Yorihiro , Di Mascio, Paolo , Eaton, Philip , Payne, Richard , Stocker, Roland
- Date: 2019
- Type: Text , Journal article , Letter
- Relation: Nature Vol. 566, no. 7745 (2019), p. 548-552
- Full Text:
- Reviewed:
- Description: Singlet molecular oxygen (O-1(2)) has well-established roles in photosynthetic plants, bacteria and fungi(1-3), but not in mammals. Chemically generated O-1(2) oxidizes the amino acid tryptophan to precursors of a key metabolite called N-formylkynurenine(4), whereas enzymatic oxidation of tryptophan to N-formylkynurenine is catalysed by a family of dioxygenases, including indoleamine 2,3-dioxygenase 1(5). Under inflammatory conditions, this haem-containing enzyme is expressed in arterial endothelial cells, where it contributes to the regulation of blood pressure(6). However, whether indoleamine 2,3-dioxygenase 1 forms O-1(2) and whether this contributes to blood pressure control have remained unknown. Here we show that arterial indoleamine 2,3-dioxygenase 1 regulates blood pressure via formation of O-1(2). We observed that in the presence of hydrogen peroxide, the enzyme generates O-1(2) and that this is associated with the stereoselective oxidation of L-tryptophan to a tricyclic hydroperoxide via a previously unrecognized oxidative activation of the dioxygenase activity. The tryptophan-derived hydroperoxide acts in vivo as a signalling molecule, inducing arterial relaxation and decreasing blood pressure; this activity is dependent on Cys42 of protein kinase G1 alpha. Our findings demonstrate a pathophysiological role for O-1(2) in mammals through formation of an amino acid-derived hydroperoxide that regulates vascular tone and blood pressure under inflammatory conditions.
Synthesis of water treatment sludge ash-based geopolymers in an Amazonian context
- Santos, Gessica, Melo Filho, Joao, Pinheiro, Mauricio, Manzato, Lizandro
- Authors: Santos, Gessica , Melo Filho, Joao , Pinheiro, Mauricio , Manzato, Lizandro
- Date: 2019
- Type: Text , Journal article
- Relation: Journal of Environmental Management Vol. 249, no. (Nov 2019), p. 8
- Full Text: false
- Reviewed:
- Description: Water treatment plants (WTP) in the City of Manaus, Brazil, generate tons of sludge daily, which are then disposed of in landfills and main watercourses, particularly two important Amazonian Rivers: the blackwater Negro River and the pale sandy-colored water Solimoes River. Because WTP-based sludges are rich in silicon and aluminum, they have been employed in the synthesis of geopolymers - alkaline activated inorganic polymers consisting of silicate and aluminosilicate chains. This paper reports the results of a geopolymeric synthesis process in which calcined sludge was explored as a source of silica and alumina. In this research, a laboratory testing program was developed to characterize the waste material generated from a water treatment plant in Manaus, whose intake water is influenced by the above referred rivers. Sample preparation involved kiln drying at 110 degrees C for 8 h, grinding in ball mill for 2 h, and calcination at 750 degrees C for 6 h. The calcined sludge was used as precursor, and potassium hydroxide added as activating alkali. Two geopolymers, one from each sludge source, were prepared following identical procedures. The chemical, compositional, morphological, thermal and mechanical properties of the fresh and hardened geopolymers were characterized. The geopolymers reached uniaxial compressive strengths of over 50 MPa at 28 days. Calcination conveyed more refined properties to the sludge-based geopolymers, akin to metakaolin-based geopolymers. The results presented herein support the technical feasibility of geopolymer synthesis in the lab scale.