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.
Trans-ethnic kidney function association study reveals putative causal genes and effects on kidney-specific disease aetiologies
- Morris, Andrew, Le, Thu, Wu, Haojia, Akbarov, Artur, van der Most, Peter, Hemani, Gibran, Smith, George, Mahajan, Anubha, Gaulton, Kyle, Nadkarni, Girish, Valladares-Salgado, Adan, Wacher-Rodarte, Niels, Mychaleckyj, Josyf, Dueker, Nicole, Guo, Xiuqing, Hai, Yang, Haessler, Jeffrey, Kamatani, Yoichiro, Stilp, Adrienne, Zhu, Gu, Cook, James, Arnlov, Johan, Blanton, Susan, de Borst, Martin, Bottinger, Erwin, Buchanan, Thomas, Cechova, Sylvia, Charchar, Fadi, Chu, Pei-Lun, Damman, Jeffrey, Eales, James, Gharavi, Ali, Giedraitis, Vilmantas, Heath, Andrew, Ipp, Eli, Kiryluk, Krzysztof, Kramer, Holly, Kubo, Michiaki, Larsson, Anders, Lindgren, Cecilia, Lu, Yingchang, Madden, Pamela, Montgomery, Grant, Papanicolaou, George, Raffel, Leslie, Sacco, Ralph, Sanchez, Elena, Stark, Holger, Sundstrom, Johan, Taylor, Kent, Xiang, Anny, Zivkovic, Aleksandra, Lind, Lars, Ingelsson, Erik, Martin, Nicholas, Whitfield, John, Cai, Jianwen, Laurie, Cathy, Okada, Yukinori, Matsuda, Koichi, Kooperberg, Charles, Chen, Yii-Der, Rundek, Tatjana, Rich, Stephen, Loos, Ruth, Parra, Esteban, Cruz, Miguel, Rotter, Jerome, Snieder, Harold, Tomaszewski, Maciej, Humphreys, Benjamin, Franceschini, Nora
- Authors: Morris, Andrew , Le, Thu , Wu, Haojia , Akbarov, Artur , van der Most, Peter , Hemani, Gibran , Smith, George , Mahajan, Anubha , Gaulton, Kyle , Nadkarni, Girish , Valladares-Salgado, Adan , Wacher-Rodarte, Niels , Mychaleckyj, Josyf , Dueker, Nicole , Guo, Xiuqing , Hai, Yang , Haessler, Jeffrey , Kamatani, Yoichiro , Stilp, Adrienne , Zhu, Gu , Cook, James , Arnlov, Johan , Blanton, Susan , de Borst, Martin , Bottinger, Erwin , Buchanan, Thomas , Cechova, Sylvia , Charchar, Fadi , Chu, Pei-Lun , Damman, Jeffrey , Eales, James , Gharavi, Ali , Giedraitis, Vilmantas , Heath, Andrew , Ipp, Eli , Kiryluk, Krzysztof , Kramer, Holly , Kubo, Michiaki , Larsson, Anders , Lindgren, Cecilia , Lu, Yingchang , Madden, Pamela , Montgomery, Grant , Papanicolaou, George , Raffel, Leslie , Sacco, Ralph , Sanchez, Elena , Stark, Holger , Sundstrom, Johan , Taylor, Kent , Xiang, Anny , Zivkovic, Aleksandra , Lind, Lars , Ingelsson, Erik , Martin, Nicholas , Whitfield, John , Cai, Jianwen , Laurie, Cathy , Okada, Yukinori , Matsuda, Koichi , Kooperberg, Charles , Chen, Yii-Der , Rundek, Tatjana , Rich, Stephen , Loos, Ruth , Parra, Esteban , Cruz, Miguel , Rotter, Jerome , Snieder, Harold , Tomaszewski, Maciej , Humphreys, Benjamin , Franceschini, Nora
- Date: 2019
- Type: Text , Journal article
- Relation: Nature Communications Vol. 10, no. 1 (2019), p. 1-14
- Full Text:
- Reviewed:
- Description: Chronic kidney disease (CKD) affects ~10% of the global population, with considerable ethnic differences in prevalence and aetiology. We assemble genome-wide association studies of estimated glomerular filtration rate (eGFR), a measure of kidney function that defines CKD, in 312,468 individuals of diverse ancestry. We identify 127 distinct association signals with homogeneous effects on eGFR across ancestries and enrichment in genomic annotations including kidney-specific histone modifications. Fine-mapping reveals 40 high-confidence variants driving eGFR associations and highlights putative causal genes with cell-type specific expression in glomerulus, and in proximal and distal nephron. Mendelian randomisation supports causal effects of eGFR on overall and cause-specific CKD, kidney stone formation, diastolic blood pressure and hypertension. These results define novel molecular mechanisms and putative causal genes for eGFR, offering insight into clinical outcomes and routes to CKD treatment development.
- Authors: Morris, Andrew , Le, Thu , Wu, Haojia , Akbarov, Artur , van der Most, Peter , Hemani, Gibran , Smith, George , Mahajan, Anubha , Gaulton, Kyle , Nadkarni, Girish , Valladares-Salgado, Adan , Wacher-Rodarte, Niels , Mychaleckyj, Josyf , Dueker, Nicole , Guo, Xiuqing , Hai, Yang , Haessler, Jeffrey , Kamatani, Yoichiro , Stilp, Adrienne , Zhu, Gu , Cook, James , Arnlov, Johan , Blanton, Susan , de Borst, Martin , Bottinger, Erwin , Buchanan, Thomas , Cechova, Sylvia , Charchar, Fadi , Chu, Pei-Lun , Damman, Jeffrey , Eales, James , Gharavi, Ali , Giedraitis, Vilmantas , Heath, Andrew , Ipp, Eli , Kiryluk, Krzysztof , Kramer, Holly , Kubo, Michiaki , Larsson, Anders , Lindgren, Cecilia , Lu, Yingchang , Madden, Pamela , Montgomery, Grant , Papanicolaou, George , Raffel, Leslie , Sacco, Ralph , Sanchez, Elena , Stark, Holger , Sundstrom, Johan , Taylor, Kent , Xiang, Anny , Zivkovic, Aleksandra , Lind, Lars , Ingelsson, Erik , Martin, Nicholas , Whitfield, John , Cai, Jianwen , Laurie, Cathy , Okada, Yukinori , Matsuda, Koichi , Kooperberg, Charles , Chen, Yii-Der , Rundek, Tatjana , Rich, Stephen , Loos, Ruth , Parra, Esteban , Cruz, Miguel , Rotter, Jerome , Snieder, Harold , Tomaszewski, Maciej , Humphreys, Benjamin , Franceschini, Nora
- Date: 2019
- Type: Text , Journal article
- Relation: Nature Communications Vol. 10, no. 1 (2019), p. 1-14
- Full Text:
- Reviewed:
- Description: Chronic kidney disease (CKD) affects ~10% of the global population, with considerable ethnic differences in prevalence and aetiology. We assemble genome-wide association studies of estimated glomerular filtration rate (eGFR), a measure of kidney function that defines CKD, in 312,468 individuals of diverse ancestry. We identify 127 distinct association signals with homogeneous effects on eGFR across ancestries and enrichment in genomic annotations including kidney-specific histone modifications. Fine-mapping reveals 40 high-confidence variants driving eGFR associations and highlights putative causal genes with cell-type specific expression in glomerulus, and in proximal and distal nephron. Mendelian randomisation supports causal effects of eGFR on overall and cause-specific CKD, kidney stone formation, diastolic blood pressure and hypertension. These results define novel molecular mechanisms and putative causal genes for eGFR, offering insight into clinical outcomes and routes to CKD treatment development.
A comparative assessment of models to predict monthly rainfall in Australia
- Bagirov, Adil, Mahmood, Arshad
- Authors: Bagirov, Adil , Mahmood, Arshad
- Date: 2018
- Type: Text , Journal article
- Relation: Water Resources Management Vol. 32, no. 5 (2018), p. 1777-1794
- Relation: http://purl.org/au-research/grants/arc/DP140103213
- Full Text: false
- Reviewed:
- Description: Accurate rainfall prediction is a challenging task. It is especially challenging in Australia where the climate is highly variable. Australia’s climatic zones range from high rainfall tropical regions in the north to the driest desert region in the interior. The performance of prediction models may vary depending on climatic conditions. It is, therefore, important to assess and compare the performance of these models in different climatic zones. This paper examines the performance of data driven models such as the support vector machines for regression, the multiple linear regression, the k-nearest neighbors and the artificial neural networks for monthly rainfall prediction in Australia depending on climatic conditions. Rainfall data with five meteorological variables over the period of 1970–2014 from 24 geographically diverse weather stations are used for this purpose. The prediction performance of each model was evaluated by comparing observed and predicted rainfall using various measures for prediction accuracy. © 2018, Springer Science+Business Media B.V., part of Springer Nature.
A new Australian record of a Parajapidae (Diplura): A potential pest of wheat
- Greenslade, Penelope, Luan, Yun-Xia
- Authors: Greenslade, Penelope , Luan, Yun-Xia
- Date: 2018
- Type: Text , Journal article
- Relation: Soil Research Vol. 56, no. 7 (2018), p. 657-663
- Full Text: false
- Reviewed:
- Description: Parajapyx isabellae (Grassi, 1886) is recorded for the first time from Australia. It is a cosmopolitan soil species found in Europe, North and South America and Asia. Womersley last studied Australian Parajapygidae 80 years ago, listing a single endemic species for the genus Parajapyx Silvestri, 1903, sensu stricta. In 2017, an unidentified Parajapyx was found in deep soil under wheat in winter, spring and summer at Harden, New South Wales, in a long-term tillage trial. It was most abundant in the minimum tillage/stubble retained plots in soil below 5 cm but rarely observed in the conventionally tilled/stubble burned plots. The same field experiment was sampled five times using the same methods over 3 years from 1993-95 but no specimens of Diplura were collected. The specimens were identified as P. isabellae using morphology and confirmed with the DNA barcoding sequence data. Most species of Parajapygidae are carnivores feeding on small arthropods but there are records from North America, Europe and Hawaii of P. isabellae feeding on roots of wheat and other agricultural crops. We provide here illustrations of species P. isabellae so that crop scientists in Australia are aware of the potential pest and can identify it. Sequence data indicate that the population may have originated from two sources.
- Authors: Clarke, Philip
- Date: 2018
- Type: Text , Journal article
- Relation: Transactions of the Royal Society of South Australia Vol. 142, no. 1 (2018), p. 27-48
- Full Text: false
- Reviewed:
- Description: This paper is a literature review of the use of birds in the Indigenous material culture of the Lower Murray River region in temperate South Australia, as observed in the early years of British colonisation. This record is augmented with additional data from fieldwork in the 1980s and early 1990s. It was found that Aboriginal people in this region made artefacts incorporating avian materials based upon their perceived physical and cultural properties. Analysis of material culture with respect to birds contributes to the understanding of Aboriginal use and perception of the Australian landscape. © 2018 Royal Society of South Australia.
A review of the scaled boundary finite element method for two-dimensional linear elastic fracture mechanics
- Song, Chongmin, Ooi, Ean Tat, Natarajan, Sundararajan
- Authors: Song, Chongmin , Ooi, Ean Tat , Natarajan, Sundararajan
- Date: 2018
- Type: Text , Journal article , Review
- Relation: Engineering Fracture Mechanics Vol. 187, no. (2018), p. 45-73
- Full Text:
- Reviewed:
- Description: The development and the application of the scaled boundary finite element method for fracture analysis is reviewed. In this method, polygonal elements (referred to as subdomains) of arbitrary number of edges are constructed, with the only limitation that the whole boundary is directly visible from the scaling centre. The element solution is semi-analytical. When applied to two-dimensional linear fracture mechanics, any kinds of stress singularities are represented analytically without local refinement, special elements and enrichment functions. The flexibility of polygons to represent arbitrary geometric shapes leads to simple yet efficient remeshing algorithms to model crack propagation. Coupling procedures with the extended finite element method, meshless method and boundary element method to handle changes in the crack morphology have been established. These developments result in an efficient framework for fracture modelling. Examples of applications are provided to demonstrate their feasibility. © 2017 Elsevier Ltd
- Authors: Song, Chongmin , Ooi, Ean Tat , Natarajan, Sundararajan
- Date: 2018
- Type: Text , Journal article , Review
- Relation: Engineering Fracture Mechanics Vol. 187, no. (2018), p. 45-73
- Full Text:
- Reviewed:
- Description: The development and the application of the scaled boundary finite element method for fracture analysis is reviewed. In this method, polygonal elements (referred to as subdomains) of arbitrary number of edges are constructed, with the only limitation that the whole boundary is directly visible from the scaling centre. The element solution is semi-analytical. When applied to two-dimensional linear fracture mechanics, any kinds of stress singularities are represented analytically without local refinement, special elements and enrichment functions. The flexibility of polygons to represent arbitrary geometric shapes leads to simple yet efficient remeshing algorithms to model crack propagation. Coupling procedures with the extended finite element method, meshless method and boundary element method to handle changes in the crack morphology have been established. These developments result in an efficient framework for fracture modelling. Examples of applications are provided to demonstrate their feasibility. © 2017 Elsevier Ltd
Altered populations of unconventional T Cell lineages in patients with Langerhans Cell Histiocytosis
- Mitchell, Jenée, Kvedaraite, Egle, von Bahr Greenwood, Tatiana, Henter, Jan-Inge, Pellicci, Daniel, Berzins, Stuart, Kannourakis, George
- Authors: Mitchell, Jenée , Kvedaraite, Egle , von Bahr Greenwood, Tatiana , Henter, Jan-Inge , Pellicci, Daniel , Berzins, Stuart , Kannourakis, George
- Date: 2018
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 8, no. 1 (2018), p. 1-13
- Full Text:
- Reviewed:
- Description: Langerhans cell histiocytosis (LCH) lesions are defined by the presence of CD1a+/CD207+ myeloid cells, but many other immune cells are present including unconventional T cells, which have powerful immunoregulatory functions. Unconventional T cell lineages include mucosal-associated invariant T (MAIT) cells, type I natural killer T (NKT) cells and gamma-delta (γδ) T cells, which are associated with many inflammatory conditions, although their importance has not been studied in LCH. We characterized their phenotype and function in blood and lesions from patients with LCH, and identified a deficiency in MAIT cell frequency and abnormalities in the subset distributions of γδ T cells and NKT cells. Such abnormalities are associated with immune dysregulation in other disease settings and are therefore potentially important in LCH. Our study is the first to recognize alterations to MAIT cell proportions in patients with LCH. This finding along with other abnormalities identified amongst unconventional T cells could potentially influence the onset and progression of LCH, thereby highlighting potential targets for new immune based therapies.
Altered populations of unconventional T Cell lineages in patients with Langerhans Cell Histiocytosis
- Authors: Mitchell, Jenée , Kvedaraite, Egle , von Bahr Greenwood, Tatiana , Henter, Jan-Inge , Pellicci, Daniel , Berzins, Stuart , Kannourakis, George
- Date: 2018
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 8, no. 1 (2018), p. 1-13
- Full Text:
- Reviewed:
- Description: Langerhans cell histiocytosis (LCH) lesions are defined by the presence of CD1a+/CD207+ myeloid cells, but many other immune cells are present including unconventional T cells, which have powerful immunoregulatory functions. Unconventional T cell lineages include mucosal-associated invariant T (MAIT) cells, type I natural killer T (NKT) cells and gamma-delta (γδ) T cells, which are associated with many inflammatory conditions, although their importance has not been studied in LCH. We characterized their phenotype and function in blood and lesions from patients with LCH, and identified a deficiency in MAIT cell frequency and abnormalities in the subset distributions of γδ T cells and NKT cells. Such abnormalities are associated with immune dysregulation in other disease settings and are therefore potentially important in LCH. Our study is the first to recognize alterations to MAIT cell proportions in patients with LCH. This finding along with other abnormalities identified amongst unconventional T cells could potentially influence the onset and progression of LCH, thereby highlighting potential targets for new immune based therapies.
- Abraham, Joji, Dowling, Kim, Florentine, Singarayer
- Authors: Abraham, Joji , Dowling, Kim , Florentine, Singarayer
- Date: 2018
- Type: Text , Journal article
- Relation: Chemosphere Vol. 192, no. (2018), p. 122-132
- Full Text: false
- Reviewed:
- Description: The environmental impact of toxic metal contamination from legacy mining activities, many of which had operated and were closed prior to the enforcement of robust environmental legislation, is of growing concern to modern society. We have carried out analysis of As and potentially toxic metals (Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, and Zn) in the surface soil of a legacy gold mining site in Maldon, Victoria, Australia, to reveal the status of the current metal concentration. The results revealed the median concentrations of metals from highest to lowest, in the order: Mn > Zn > As > Cr > Cu > Pb > Ni > Co > Hg > Cd. The status of site was assessed directly by comparing the metal concentrations in the study area with known Australian and Victorian average top soil levels and the health investigation levels set by the National Environmental Protection Measures (NEPM) and the Department of Environment and Conservation (DEC) of the State of Western Australia. Although, median concentrations of As, Hg, Pb, Cu and Zn exceeded the average Australian and Victorian top soil concentrations, only As and Hg exceeded the ecological investigation levels (EIL) set by DEC and thus these metals are considered as risk to the human and aquatic ecosystems health due to their increase in concentration and toxicity. In an environment of climate fluctuation with increased storm events and forest fires may mobilize these toxic metals contaminants, pose a real threat to the environment and the community. © 2017 Elsevier Ltd
Bio-reinforced self-healing concrete using magnetic iron oxide nanoparticles
- Seifan, Mostafa, Sarmah, Ajit, Ebrahiminezhad, Alireza, Ghasemi, Younes, Samani, Ali Khajeh, Berenjian, Aydin
- Authors: Seifan, Mostafa , Sarmah, Ajit , Ebrahiminezhad, Alireza , Ghasemi, Younes , Samani, Ali Khajeh , Berenjian, Aydin
- Date: 2018
- Type: Text , Journal article
- Relation: Applied Microbiology and Biotechnology Vol. 102, no. 5 (2018), p. 2167-2178
- Full Text: false
- Reviewed:
- Description: Immobilization has been reported as an efficient technique to address the bacterial vulnerability for application in bio self-healing concrete. In this study, for the first time, magnetic iron oxide nanoparticles (IONs) are being practically employed as the protective vehicle for bacteria to evaluate the self-healing performance in concrete environment. Magnetic IONs were successfully synthesized and characterized using different techniques. The scanning electron microscope (SEM) images show the efficient adsorption of nanoparticles to the Bacillus cells. Microscopic observation illustrates that the incorporation of the immobilized bacteria in the concrete matrix resulted in a significant crack healing behavior, while the control specimen had no healing characteristics. Analysis of bio-precipitates revealed that the induced minerals in the cracks were calcium carbonate. The effect of magnetic immobilized cells on the concrete water absorption showed that the concrete specimens supplemented with decorated bacteria with IONs had a higher resistance to water penetration. The initial and secondary water absorption rates in bio-concrete specimens were 26% and 22% lower than the control specimens. Due to the compatible behavior of IONs with the concrete compositions, the results of this study proved the potential application of IONs for developing a new generation of bio self-healing concrete.
Charles Joseph La Trobe and his administration of the Wadawurrung, 1839‑1853
- Authors: Cahir, David (Fred)
- Date: 2018
- Type: Text , Journal article
- Relation: Journal of the C.J. La Trobe Society Vol. 17, no. 1 (2018), p. 5-16
- Full Text:
- Reviewed:
- Description: Maggie Black’s work as a writer has focused on disadvantaged people in Africa, Asia and Latin America. Her view of the damaging impact of contemporary forms of development on Indigenous societies is articulated in her book, International Development: Illusions and Realities (New Internationalist, 2015). This proved a useful basis for studying her great‑grandfather’s pioneering life in Victoria. Niel Black’s archive found its way to State Library Victoria thanks to Margaret Kiddle, author of Men of Yesterday (Melbourne University Press, 1961), which also drew heavily on his remarkable voice. This article is a shortened version of a chapter in the author’s Up Came a Squatter: Niel Black of Glenormiston 1839‑1880 (NewSouth, 2016).
- Authors: Cahir, David (Fred)
- Date: 2018
- Type: Text , Journal article
- Relation: Journal of the C.J. La Trobe Society Vol. 17, no. 1 (2018), p. 5-16
- Full Text:
- Reviewed:
- Description: Maggie Black’s work as a writer has focused on disadvantaged people in Africa, Asia and Latin America. Her view of the damaging impact of contemporary forms of development on Indigenous societies is articulated in her book, International Development: Illusions and Realities (New Internationalist, 2015). This proved a useful basis for studying her great‑grandfather’s pioneering life in Victoria. Niel Black’s archive found its way to State Library Victoria thanks to Margaret Kiddle, author of Men of Yesterday (Melbourne University Press, 1961), which also drew heavily on his remarkable voice. This article is a shortened version of a chapter in the author’s Up Came a Squatter: Niel Black of Glenormiston 1839‑1880 (NewSouth, 2016).
- Abraham, Joji, Dowling, Kim, Florentine, Singarayer
- Authors: Abraham, Joji , Dowling, Kim , Florentine, Singarayer
- Date: 2018
- Type: Text , Journal article
- Relation: Science of the Total Environment Vol. 616-617, no. (2018), p. 1022-1034
- Full Text: false
- Reviewed:
- Description: Conducting controlled burns in fire prone areas is an efficient and economic method for forest management, and provides relief from the incidence of high severity wild fires and the consequent damage to human property and ecosystems. However, similar to wild fires, controlled burns also affect many of the physical and biogeochemical properties of the forest soil and may facilitate remobilization of potentially toxic elements (PTEs) sequestered in vegetation and soil organic matter. The objective of the current study is to investigate the mobilization of PTEs, in Central Victorian forest soils in Australia after a controlled burn. Surface soil samples were collected two days before and after the controlled burn to determine the concentration of PTEs and to examine the physicochemical properties. Results show that As, Cd, Mn, Ni and Zn concentrations increased 1.1, 1.6, 1.7, 1.1 and 1.9 times respectively in the post-burn environment, whereas the concentrations of Hg, Cr and Pb decreased to 0.7, 0.9 and 0.9 times respectively, highlighting considerable PTE mobility during and after a controlled burn. Whilst these results do not identify very strong correlations between physicochemical properties of soil and PTEs in the pre- and post-burn environments, PTEs themselves demonstrated very strong and significant correlations. The mobilization of As, Hg and other toxic elements raise potential health concerns as the number of controlled burns are projected to increase in response to climate change. Due to this increased level of PTE release and remobilization, the use of any kinds of controlled burn must be carefully considered before being used as a forest management strategy in mining-affected landscapes which include areas with high PTE concentrations. © 2017 Elsevier B.V.
- Barua, Bipasha, Barua, Suborna, Hasan Rana, Rezwanul
- Authors: Barua, Bipasha , Barua, Suborna , Hasan Rana, Rezwanul
- Date: 2018
- Type: Text , Journal article
- Relation: The Journal of Developing Areas Vol. 52, no. 3 (2018), p. 153-168
- Full Text: false
- Reviewed:
- Description: Non-life insurance companies are an important part of the financial system in any country. Constant development and financial sustainability of these institutions is key to foster the rapidly growing economic activities of emerging economies like Bangladesh. This study made an attempt to establish the impact of different firm-specific factors on profitability using the non-life insurance sector in Bangladesh. A thriving insurance industry, especially in the non-life sector, can accelerate economic growth by mobilizing large funds and providing risk-hedging services to economic activities. This paper investigates the temporary and permanent impact of different firm-specific factors on financial performance, using the case of the non-life insurance sector in Bangladesh: one of the fastest growing economies in the world. Using panel data on 16 non-life insurance companies from 1999 to 2014, this paper utilizes both Static Panel Data (SPD) and Dynamic Panel Data (DPD) estimation techniques. For DPD estimation, a Pooled Mean Group (PMG) estimator built on an ARDL Framework that can produce short run and long run impacts separately has been employed. In addition to the average impact generated from static estimations, this paper identifies the significant impact of all variables on profitability in the long-term (those of a permanent nature) while the investment ratio shows some impact in the short-term (those of a temporary nature). The results of the study indicate that the average impact is predominantly derived from the long-term and thus appear to be permanent in nature. Moreover, investment ratio contributes positively to profitability, mostly in the short-term (temporarily) with some effects in the long-term. The findings on liquidity and investment ratio suggest the permanent nature of their impact on profitability in the long-term and, hence, insurers are probably better served investing funds in short-term opportunities (e.g. investing in securities) rather than in long-term ones. Lastly, the empirical results regarding the impact of leverage is not clear, as it shows mixed impact in two different estimations, including the permanent nature of negative impact in the long-term. The non-life insurance companies of Bangladesh should implement strong policies to reduce the faulty underwriting procedures to improve the profitability. This paper offers significant contributions to the literature by separately identifying the 'temporary' and 'permanent' impact of several determinants, thereby producing novel estimations for Bangladesh that may have implications for other emerging economies.