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Does climate play any role in covid-19 spreading? : an Australian perspective

- Abraham, Joji, Turville, Christopher, Dowling, Kim, Florentine, Singarayer

  • Authors: Abraham, Joji , Turville, Christopher , Dowling, Kim , Florentine, Singarayer
  • Date: 2021
  • Type: Text , Journal article
  • Relation: International Journal of Environmental Research and Public Health Vol. 18, no. 17 (2021), p.
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  • Description: Compared to other countries, the COVID-19 pandemic did not severely affect Australia as measured by total deaths until mid-2021. Though a substantial number of daily confirmed cases (up to 698) were reported during the second wave, most of them were from the southern state of Victoria. This study examined the possible correlations between climate variables and the number of daily confirmed COVID-19 cases in Victoria, Australia, from 25 January to 31 October 2020. Appropriate regression models and cross-correlation diagnostics were used to examine the effect of temperature, rainfall, solar exposure, and ultraviolet index (UVI) with the number of daily confirmed cases. Significant positive associations were identified for solar exposure and maximum and average UVI for confirmed cases one and 19 days later. Negative associations for these variables were found for confirmed cases five days later. Minimum temperature had a significant negative correlation one day later and a positive effect 21 days later. No significant correlation was found for maximum temperature and rainfall. The most significant relationships were found for confirmed cases 19 days after changes in the meteorological variables. A 1% increase in solar exposure, maximum UVI, and average UVI was associated with a 0.31% (95% CI: 0.13 to 0.51), 0.71% (95% CI: 0.43 to 0.98), and 0.63% (95%CI: 0.20 to 1.61) increase 19 days later in the number of confirmed cases, respectively. The implications of these results can be used in the public health management of any possible future events in Australia. It also highlights the significance of considering the climatic variables and seasonality in all kinds of epidemics and pandemics. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Influence of controlled burning on the mobility and temporal variations of potentially toxic metals (PTMs) in the soils of a legacy gold mine site in Central Victoria, Australia

- Abraham, Joji, Dowling, Kim, Florentine, Singarayer

  • Authors: Abraham, Joji , Dowling, Kim , Florentine, Singarayer
  • Date: 2018
  • Type: Text , Journal article
  • Relation: Geoderma Vol. 331, no. (2018), p. 1-14
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  • Description: Controlled burns also known as managed burns or prescribed fires conducted in fire-prone areas are an efficient and economic option to reduce the frequency and intensity of wildfires. The objective of this study is to investigate the remobilization of potentially toxic metals (PTMs) in the soils of a legacy gold mine site in Central Victoria, Australia after a controlled burn and to describe their temporal variations in concentrations. Soil samples were collected two days before, two days after and five times later (3, 6, 9, 12 months and after major rainfall) in the post-burn environment after a controlled burn, from the Maldon legacy mine site and analysed for PTM concentrations. The results revealed PTM mobilization after the burn and most of the PTMs (As, Cd, Cu, Mn, Ni, and Zn) evidenced an increase immediately after the burn but a reduction in the subsequent post-burn environment. The increase is postulated to be associated with addition of PTM enriched ash to the soil, while the decrease is due to the removal of ash and surface soil by wind activity as well as rainfall runoff and leaching. The PTM mobility is of specific concern due to the negative impacts on human and ecosystems health. Climate change and the resulting projection of increased forest fire frequency highlight the environmental significance, given the expected concomitant increase in PTM mobilization through wildfires and controlled burns. Hence, the practice of controlled burning should be carefully considered as a forest management option in any legacy mining areas and indeed in other areas where PTM contamination is reported. © 2018

The unquantified risk of post-fire metal concentration in soil : A Review

- Abraham, Joji, Dowling, Kim, Florentine, Singarayer

  • Authors: Abraham, Joji , Dowling, Kim , Florentine, Singarayer
  • Date: 2017
  • Type: Text , Journal article
  • Relation: Water, Air, and Soil Pollution Vol. 228, no. 5 (2017), p. 1-33
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  • Description: Forest fire is a natural disturbance that occurs in many terrestrial ecosystems specifically in the semi-arid environments and is considered to be an important cause of environmental change. Though many causes of fire are identified, including lightning, volcanic eruption, power line sparks, etc., human involvement is the most significant factor. Fire events are able to alter the physical, chemical and biogeochemical properties of the soil and surface materials and are able to release major and trace metals into the environment. This may be more significant in mining-affected and industrial landscapes, where elevated concentrations of metals present in the soil. After the fire event, metals become more mobile due to the increase in soil surface exposure and the mobility associated with ash dispersal. This mobility may increase the bioavailability of the metals, which may generate water quality issues and may contribute to human and environmental health concerns. Even though, the influences of fire on many soil properties are well established, the behaviour of metals with respect to fire is not well investigated. However, a few studies report that major and trace metals include Cd, Cr, Co, Cu, Hg, Mn, Ni, Pb, Zn and As are mobilized after fire with increased concentrations in soil and water resources and this might pose a risk to human health and ecosystems. Climate change may increase the intensity, frequency and areal extend of fire events and hence increase the metal concentrations and their potential health impacts. This paper reviews post-fire (wild fire) mobility of metals in soil common in contaminated forest ecosystems. The human and ecological health risks of these metals are also considered. © 2017, Springer International Publishing Switzerland.

Can optimum solar radiation exposure or supplemented vitamin D intake reduce the severity of COVID-19 symptoms?

- Abraham, Joji, Dowling, Kim, Florentine, Singarayer

  • Authors: Abraham, Joji , Dowling, Kim , Florentine, Singarayer
  • Date: 2021
  • Type: Text , Journal article , Review
  • Relation: International Journal of Environmental Research and Public Health Vol. 18, no. 2 (2021), p. 1-21
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  • Description: The foremost mortality-causing symptom associated with COVID-19 is acute respiratory distress syndrome (ARDS). A significant correlation has been identified between the deficiency in vitamin D and the risk of developing ARDS. It has been suggested that if we can reduce or modify ARDS in COVID-19 patients, we may significantly reduce the severity of COVID-19 symptoms and associated mortality rates. The increased mortality of dark-skinned people, who have a reduced UV absorption capacity, may be consistent with diminished vitamin D status. The factors associated with COVID-19 mortality, such as old age, ethnicity, obesity, hypertension, cardiovascular diseases, and diabetes, are all found to be linked with vitamin D deficiency. Based on this review and as a precautionary measure, it is suggested that the adoption of appropriate and safe solar exposure and vitamin D enriched foods and supplements should be considered to reduce the possible severity of COVID-19 symptoms. Safe sun exposure is deemed beneficial globally, specifically in low and middle- income countries, as there is no cost involved. It is also noted that improved solar exposure and vitamin D levels can reduce the impact of other diseases as well, thus assisting in maintaining general human well-being. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Controlled burn and immediate mobilization of potentially toxic elements in soil, from a legacy mine site in Central Victoria, Australia

- 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
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  • 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.

Assessment of potentially toxic metal contamination in the soils of a legacy mine site in Central Victoria, Australia

- 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
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  • 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

Effects of prescribed fire and post-fire rainfall on mercury mobilization and subsequent contamination assessment in a legacy mine site in Victoria, Australia

- Abraham, Joji, Dowling, Kim, Florentine, Singarayer

  • Authors: Abraham, Joji , Dowling, Kim , Florentine, Singarayer
  • Date: 2018
  • Type: Text , Journal article
  • Relation: Chemosphere Vol. 190, no. (2018), p. 144-153
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  • Description: Prescribed fire conducted in fire-prone areas is a cost-effective choice for forest management, but it also affects many of the physicochemical and bio-geological properties of the forest soil, in a similar manner to wild fires. The aim of this study is to investigate the nature of the mercury mobilization after a prescribed fire and the subsequent temporal changes in concentration. A prescribed fire was conducted in a legacy mine site in Central Victoria, Australia, in late August 2015 and soil sample collection and analyses were carried out two days before and two days after the fire, followed by collection at the end of each season and after an intense rainfall event in September 2016. Results revealed the occurrence of mercury volatilization (8.3–97%) during the fire, and the mercury concentration displayed a significant difference (p < 0.05) before and immediately after the fire. Integrated assessment with number of pollution indices has shown that the study site is extremely contaminated with mercury during all the sampling events, and this poses a serious ecological risk due to the health impacts of mercury on human and ecosystems. In times of climate fluctuation with concomitant increase in forest fire (including prescribed fire), and subsequent precipitation and runoff, the potential for an increased amount of mercury being mobilized is of heighted significance. Therefore, it is recommended that prescribed fire should be cautiously considered as a forest management strategy in any mercury affected landscapes. © 2017 Elsevier Ltd

Risk of post-fire metal mobilization into surface water resources : A review

- Abraham, Joji, Dowling, Kim, Florentine, Singarayer

  • Authors: Abraham, Joji , Dowling, Kim , Florentine, Singarayer
  • Date: 2017
  • Type: Text , Journal article , Review
  • Relation: Science of the Total Environment Vol. 599-600, no. (2017), p. 1740-1755
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  • Description: One of the significant economic benefits to communities around the world of having pristine forest catchments is the supply of substantial quantities of high quality potable water. This supports a saving of around US$ 4.1 trillion per year globally by limiting the cost of expensive drinking water treatments and provision of unnecessary infrastructure. Even low levels of contaminants specifically organics and metals in catchments when in a mobile state can reduce these economic benefits by seriously affecting the water quality. Contamination and contaminant mobility can occur through natural and anthropogenic activities including forest fires. Moderate to high intensity forest fires are able to alter soil properties and release sequestered metals from sediments, soil organic matter and fragments of vegetation. In addition, the increase in post-fire erosion rate by rainfall runoff and strong winds facilitates the rapid transport of these metals downslope and downstream. The subsequent metal deposition in distal soil and water bodies can influence surface water quality with potential impacts to the larger ecosystems inclusive of negative effects on humans. This is of substantial concern as 4 billion hectares of forest catchments provide high quality water to global communities. Redressing this problem requires quantification of the potential effects on water resources and instituting rigorous fire and environmental management plans to mitigate deleterious effects on catchment areas. This paper is a review of the current state of the art literature dealing with the risk of post-fire mobilization of the metals into surface water resources. It is intended to inform discussion on the preparation of suitable management plans and policies during and after fire events in order to maintain potable water quality in a cost-effective manner. In these times of climate fluctuation and increased incidence of fires, the need for development of new policies and management frameworks are of heighted significance. © 2017 Elsevier B.V.

Analysis of a combined circular–toppling slope failure in an open–pit

- Al Mandalawi, Maged, You, Greg, Dahlhaus, Peter, Dowling, Kim, Sabry, Mohannad

  • Authors: Al Mandalawi, Maged , You, Greg , Dahlhaus, Peter , Dowling, Kim , Sabry, Mohannad
  • Date: 2019
  • Type: Text , Conference paper
  • Relation: 2nd GeoMEast International Congress and Exhibition on Sustainable Civil Infrastructures, Egypt 2018 - The official international congress of the Soil-Structure Interaction Group in Egypt, SSIGE 2018 p. 10-30
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  • Description: Most studies of rock slope failures on open–pit mines have considered either toppling or circular failure stability analysis. By comparison, complex circular–toppling failure has received much less attention in the published literature. This paper presents a study using a range of methods to investigate a failure that occurred in July 2008 in Handlebar Hill, an open–pit base metal mine, near Mt Isa, Australia. Circular failure is the typical slope failure mechanism in slopes with low–strength rocks, although direct/flexural toppling of jointed columns can also occur. The study reviews circular–toppling failure mechanisms in the context of the local geotechnical and geo–hydrological conditions, which include the interaction between fault contacts and the existing deformed rocks. General limit equilibrium methods are used to evaluate the sensitivity of slope models to rock strength parameters and the trigger mechanisms. Finite element methods are used to assess the failure mechanisms and slope displacement, and a kinematic approach is used to evaluate structurally controlled slope instability mechanisms. The results demonstrate that the most credible failure mechanism was shearing along a circular path through the upper weaker rocks (leached Magazine Shale) that in turn initiated secondary block toppling, and the progressive nature of the slope failure mechanism. The use of conventional and numerical techniques for back–analysis of the combined circular–toppling failure provided key insights into the failure mechanisms and factors controlling slope instability. © 2019, Springer Nature Switzerland AG.

Modelling and analyses of rock bridge fracture and step-path failure in open-pit mine rock slope

- Al Mandalawi, Maged, You, Greg, Dahlhaus, Peter, Dowling, Kim, Sabry, Mays

  • Authors: Al Mandalawi, Maged , You, Greg , Dahlhaus, Peter , Dowling, Kim , Sabry, Mays
  • Date: 2019
  • Type: Text , Conference paper
  • Relation: 2nd GeoMEast International Congress and Exhibition on Sustainable Civil Infrastructures, Egypt 2018 - The official international congress of the Soil-Structure Interaction Group in Egypt, SSIGE 2018, 24-28 November 2018 p. 198-226
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  • Description: Rock Bridge fracturing and coalescence with pre-existing discontinuities in rock mass due to the initiation, propagation and interaction of these fractures refers to instability mode of step-path failure. Step-path failure is a typical type of instable mode of man-made and natural rock slopes. The continuum finite element method was applied to work on deeper insight into the propagation of tensile cracks which developing in the intact rock bridges that can finally coalesce to form step-path failure. In this paper, based on the intact rock fracturing hypothesis, two selected slope simulations from the Handlebar Hill open - pit mine near Mt. Isa in Queensland, Australia, modeled the process of fracturing and step-path failure through different pre-existing discontinuities. The empirical models of Bobet and Einstein (1998) and the progressively cracks development are observed within crack initiation, propagation and coalescence in the intact rock bridges. Proposed slope models of the mine included four joint-net distributions through the rock masses considering the geometry of structures (dip angles, spacing, lengths and orientation) illustrated the extension cracks from the flaw tips and propagated to the slope surface. Modes of intact rock bridges fracturing (shear, tensile and a combination of shear and tensile) have been observed. Tensile fracture is usually generated when the rock bridge angle is sub-vertical. Shear fracture can be initiated in less steep rock bridge angles. A combination of shear and tensile failure is normally generated in slopes with. Slope with explicit large-scale structures of steeper dip angles increased the yielding. Larger structures show much higher potential for yielding as the tensile stresses increasing. Major joint plane spacing resulted in less potential for relative deformations between neighboring structures and consequently reduced slope instability. The changes of length and spacing have more influence on slope stability than a change in the dip angle of the structures. © 2019, Springer Nature Switzerland AG.

Slope stability and rockfall Hazard analysis in open pit zinc mine

- Almandalawi, Maged, You, Greg, Dahlhaus, Peter, Dowling, Kim, Sabry, Mohannad

  • Authors: Almandalawi, Maged , You, Greg , Dahlhaus, Peter , Dowling, Kim , Sabry, Mohannad
  • Date: 2015
  • Type: Text , Journal article
  • Relation: International Journal of GEOMATE Vol. 8, no. 1 (2015), p. 1143-1150
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  • Description: Rockfalls are a major safety hazard in open cut mines, particularly in large-scale deep pits. The geotechnical design relies on in-situ, site-specific, rock slope data to predict the trajectories and velocities of rockfalls that present a residual hazard in the mines. This paper presents slope stability analyses using both static general limit equilibrium methods and finite element stress analyses to estimate unstable areas and slope displacements in the mid-west slope at Glencore Zinc's Handlebar Hill Open Cut mine at Mt. Isa, Queensland, Australia. A conventional program -RocFall- was used for the slope rockfall risk assessment. Results indicate the possible slope benches involved in the initiation of rockfalls, and the maximum run-out distance, which could be defined as the pit's hazardous zone. A rockfall restraining system to absorb the impact energy of boulders and prevent them further falling was also modelled. © 2015, International Journal of GEOMATE.

Kinematic assessment of slopes at handlebar hill open cut mine, Mt. Isa, Queensland, Australia

- Almandalawi, Maged, You, Greg, Dowling, Kim, Dahlhaus, Peter

  • Authors: Almandalawi, Maged , You, Greg , Dowling, Kim , Dahlhaus, Peter
  • Date: 2016
  • Type: Text , Journal article
  • Relation: International Journal of GEOMATE Vol. 10, no. 1 (2016), p. 1575-1583
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  • Description: A complete kinematic analysis was conducted for the west slope at the Handlebar Hill mine using the Rocscience/Dips 6.0 software. The west slope was divided into three zones: W1 (south-west), W2 (mid-west) and W3 (north-west), which were then subdivided into nine small elements to increase the certainty of parameters. This enabled the analysis to define the potential kinematics of motions of critical structures. Small scale joints, bedding, faults, shears along the discontinuities were plotted and the data were analysed systematically. The results indicated that the potential toppling mode created by discontinuities can lead to direct/flexural toppling failure. The kinematic feasibility also revealed that the intersections of the discontinuities within the critical zone can structurally control the wedge planar failure modes. The results will assist the mine geotechnical engineers to understand the potential slope failure mechanisms and their locations. © 2016, International Journal of GEOMATE.

Assessment of cadmium distribution in some Australian krasnozems by sequential extraction

- Butt, David, Dowling, Kim, Vinden, Peter

  • Authors: Butt, David , Dowling, Kim , Vinden, Peter
  • Date: 2008
  • Type: Text , Journal article
  • Relation: Water, Air, and Soil Pollution Vol. 190, no. 1-4 (2008), p. 157-169
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  • Description: A sequential extraction procedure was used to investigate the influence of long-term phosphate fertilization on the distribution of cadmium throughout the major components of krasnozemic soils in the potato growing district located to the East of Ballarat, Victoria, Australia. The soil fractions investigated consisted of the water soluble, exchangeable, weakly bound to metal oxides, strongly bound to metal oxides, bound to organic material and residual. Other soil parameters, such as pHH2O, pHCaCl2, electrolytical conductivity and total organic material were investigated. The concentrations of Ca, Mg, Fe, Mn and Zn in each soil fraction were also measured. The total concentration of cadmium in the farmed soils had increased from the background level of 100.5
  • Description: C1

Germination biology of three populations of Navua sedge (Cyperus aromaticus)

- Chadha, Aakansha, Florentine, Singarayer, Dhileepan, Kunjithapatham, Dowling, Kim, Turville, Christopher

  • Authors: Chadha, Aakansha , Florentine, Singarayer , Dhileepan, Kunjithapatham , Dowling, Kim , Turville, Christopher
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Weed Science Vol. 69, no. 1 (2021), p. 69-81
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  • Description: Navua sedge [Cyperus aromaticus (Ridley) Mattf. & Kük.] is an aggressive perennial sedge native to equatorial Africa that has become problematic in many Pacific islands and wet, tropical Queensland, Australia. It has had a significant impact on the livestock-grazing industry, sugarcane (Saccharum officinarum L.) and banana (Musa acuminata Colla) plantations, and various other ecosystems. A laboratory-based research investigation was conducted to understand germination and emergence requirements under various environmental conditions of three geographically varied populations sourced from South Johnstone (SJ), Mackay (M) and Nyleta Creek (NC) in Queensland. Germination was identified to be stimulated by light, with no germination recorded under darkness. Populations SJ and NC had optimal germination at alternating temperatures of 25/15, 30/20, and 35/25 C, whereas population M had optimal germination at 25/15 and 30/20 C. All populations recorded greater than 85% germination at all pH levels tested. Seeds of population SJ were more sensitive to salinity compared with populations M and NC, with SJ showing no germination at 100 mM, whereas populations M and NC had 23% and 9% germination, respectively. An inverse relationship was observed between osmotic potential and germination, with no germination recorded at osmotic potentials below -0.8 MPa in any population, indicating moisture availability is a critical requirement for germination. Exposing seeds to 120 C radiant heat completely inhibited germination in populations M and NC, whereas 3% of population SJ germinated following a 180-s exposure at 120 C. Seedling emergence decreased as planting depth increased. Emergence was greatest for seeds on the soil surface or at 0.5-cm burial depth, consistent with germination being stimulated by light. Knowledge of these biological characteristics of C. aromaticus seed germination will assist in investigation of suitable control actions for this species, particularly in the early stage of its invasion into new areas, and will contribute to significant reduction in the soil seedbank. © 2021 Cambridge University Press. All rights reserved.

Efficacy of halosulfuron-methyl in the management of Navua sedge (Cyperus aromaticus) : differential responses of plants with and without established rhizomes

- Chadha, Aakansha, Florentine, Singarayer, Dhileepan, Kunjithapatham, Turville, Christopher, Dowling, Kim

  • Authors: Chadha, Aakansha , Florentine, Singarayer , Dhileepan, Kunjithapatham , Turville, Christopher , Dowling, Kim
  • Date: 2022
  • Type: Text , Journal article
  • Relation: Weed Technology Vol. 36, no. 3 (2022), p. 397-402
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  • Description: Navua sedge is a creeping perennial sedge commonly found in tropical environments and is currently threatening many agroecosystems and ecosystems in Pacific Island countries and northern Queensland, Australia. Pasture and crop productions have been significantly impacted by this weed. The efficacy of halosulfuron-methyl on Navua sedge plants with and without well-established rhizomes was evaluated under glasshouse conditions. Halosulfuron-methyl was applied to plants with established rhizomes at three stages; mowed, pre-flowering, and flowering growth stages, whereas plants without established rhizomes were treated at seedling, pre-flowering and flowering growth stages. At each application time, halosulfuron-methyl was applied at four dose rates of 0, 38, 75, and 150 g ai ha-1. Mortality of 27.5%, 0%, and 5% was recorded in rhizomatous Navua sedge when treated with 75 g ai ha-1 of halosulfuron-methyl at the mowed, pre-flowering stage and flowering stages, respectively. At 10 wk after treatment (WAT), there were no tillers in surviving plants treated at any of the application times. By 16 WAT, the number of tillers increased to 15, 24, and 26 in mowed, pre-flowering, and flowering stages, respectively. Although halosulfuron-methyl is effective in controlling aboveground growth, subsequent emergence of new growth from the rhizome confirms the failure of the herbicide to kill the rhizome. Application of 75 g ai ha-1 of halosulfuron-methyl provided 100% mortality in plants treated at seedling and pre-flowering stages, and 98% mortality when treated at flowering stage in non-rhizomatous plants. A single application of halosulfuron-methyl is highly effective at controlling Navua sedge seedlings but not effective at controlling plants with established rhizomes. © 2022 Cambridge University Press. All rights reserved.

Evaluation of Florpyrauxifen-Benzyl for the control of Cyperus aromaticus (Navua sedge)

- Chadha, Aakansha, Florentine, Singarayer, Dhileepan, Kunjithapatham, Turville, Christopher, Dowling, Kim

  • Authors: Chadha, Aakansha , Florentine, Singarayer , Dhileepan, Kunjithapatham , Turville, Christopher , Dowling, Kim
  • Date: 2022
  • Type: Text , Journal article
  • Relation: Advances in Weed Science Vol. 40, no. (2022), p.
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  • Description: Background: Cyperus aromaticus (Navua sedge) is a creeping perennial sedge common to tropical environments, currently threatening many agroecosystems and ecosystems in Pacific Island countries and northern Queensland in Australia. Objective: A glasshouse study was conducted to evaluate the efficacy of florpyrauxifen-benzyl on C. aromaticus plants with and without established rhizomes. Methods: The plants with established rhizomes were treated at three application times being mowed, pre-flowering and flowering growth stages and plants without established rhizomes were treated at seedling, pre-flowering and flowering growth stages. At each application time, plants were treated with four rates of florpyrauxifen-benzyl: 0, 15, 30 and 60 g a.i. ha-1 and control. Results: There was no mortality in the plants with established rhizomes. Reduction in the number of tillers was observed at four weeks after treatment (WAT) in plants treated with 30 and 60 g a.i. ha-1 of herbicide, however, there was new growth from the rhizomes and the number of tillers increased at 8 WAT. Conversely, florpyrauxifen-benzyl provided above 95% control in plants without established rhizomes. Conclusions: These results indicate florpyrauxifen-benzyl can help manage a new C. aromaticus infestation prior to the establishment of rhizomes. However, it has little to no impact on C. aromaticus plants with established rhizomes, and other management options should be employed to control them. © 2022, Sociedade Brasileira da Ciencia das Plantas Daninha. All rights reserved.

Perceptions of engineering from female, secondary college students in regional Victoria

- Darby, Linda, Hall, Stephen, Dowling, Kim, Kentish, Barry

Toenail arsenic : Incorporation patterns and biomarker potential

- Dowling, Kim, Pearce, Dora, Gerson, Andrea, Sim, Malcolm, Sutton, Stephen, Newville, Matthew

Sustainability and Regional Development: When Brownfields become playing fields sustainability in the mineral and energy sectors

- Dowling, Kim, Florentine, Singarayer, Martin, Rachael, Pearce, Dora

  • Authors: Dowling, Kim , Florentine, Singarayer , Martin, Rachael , Pearce, Dora
  • Date: 2016
  • Type: Text , Book chapter
  • Relation: Sustainability in the Mineral and Energy Sectors Chapter 17 p. 305-321
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  • Description: Human activity has, in the recent past, resulted in substantial changes in land cover, ecosystem health, and the ability of affected ecosystems to return to their orginal state. This necessitates further human intervention to recreate the systems functions than the present. Earlier restoration activities have not been documented extensively. This hinders our efforts to identify approaches that might support further work. "From Abstract"

Soil and vegetable analysis from the Victorian goldfields : Characterization of a potential backyard hazard

- Dowling, Kim, Harvey, G., Waldron, H., Garnett, D.