56 research outputs found
Exploring the networks of government scientists using Social Network Analysis: a scoping study
Scientists working for the New South Wales (NSW) Office of Environment and Heritage (OEH) provide rigorous evidence and advice to support government priorities which include protecting the natural environment. They also collaborate with and attract non-government researchers to work on government priorities. In this scoping study, we used Social Network Analysis (SNA) to visualise the ego networks of six government scientists from OEH who work on biodiversity conservation and landscape management. This allowed us to explore the potential reach of their advice and information within OEH and beyond; and examine gaps and redundancy in the stacked ego networks
Soil management and production of Alfisols in the semi-arid tropics. II. Deriving USDA curve numbers from rainfall simulator data
A comparison of USDA-SCS runoff curve numbers from model calibration using experimental runoff data and rainfall simulation is presented. A rainfall simulator was used to derive curve numbers for a range of antecedent soil water contents and surface cover conditions for an Alfisol soil in the semi-arid tropics of India. These relationships between cover and curve number are compared with relationships that were obtained using model calibration in Part I of this paper.
The results showed that rainfall simulation on dry soils was most useful for deriving curve numbers. Derived curve numbers under dry antecedent conditions (CN1) can be easily adjusted to curve numbers for average antecedent conditions (CN2) which is an input parameter for many agricultural simulation models. Further analysis of the effects of cover on curve number showed that a linear function explained up to 86% of the variability between curve number and surface cover.
Curve numbers derived from rainfall simulators were similar to those obtained from model calibration. This has improved confidence in using rainfall simulation to measure a runoff curve number
The cropping systems-model PERFECT as a quantitative tool in land evaluation - an example for wheat cropping in the Maranoa area of Queensland
The mechanistic cropping systems model PERFECT was validated for six different soils and used as a tool to evalute land suitability of wheat cropping in the Maranoa, a marginal cropping area of Queensland. Using 100 years of historic climate data from the area, and crop, soil and management parameters, simulations provided an objective insight into the key interactions of the cropping system. Current methods of land suitability evaluation are qualitative and rely on the experience of the land resource surveyor and local precedent. Consequently, where local precedent is lacking, as in marginal areas, current methods are considered less reliable and quantiative data from simulation studies will be useful. Using this process, the significance of key components of the systems (climate, plant available water capacity, soil nitrate and soil loss hazard) were quantified. These quantitative data were used to establish critical values for diagnostic attributes for land suitability evaluation in the Maranoa. The role for this approach as a tool in quantitative land evaluation is discussed
The multi-risk vulnerability of global coal regions in the context of mine closure
Coal mining industries face real challenges to meet legal demands on a low carbon future. The history of coal in industrial transitions seems to come to a rapid end, accompanied by widespread boom of closing active coal mining projects. This change can result in negative ramifications for coal mining regions, involving a complex interplay of multiple risks. In this paper, we aim to analyse the complexity of environmental, social, and governance factors that can cause significant difficulties in closure of coal mining operations. We identify multi-factor risk profiles for operating mines by applying spatially explicit indicators within a proposed multi-risk framework. The indicators have not been captured by conventional market, as they tend to be more long-term oriented in the context of strategy and performance. We map eight risk categories: stability, water and climate, biodiversity, vulnerability of land uses, indigenous people, social fragility, political fragility, and regulatory environment, and analyse their effect on a global dataset of active open pit coal mines. The spatial analysis reveals that a significant proportion of the projects face accumulation of multiple risk factors. A total of 552 projects out of 916 show medium to very high-risk occurrence. In this paper, we present global risk vulnerability across the coal mining projects by indicating extent to which operators of the mines face multiple risk factors when planning for closure
Molecular dissection of box jellyfish venom cytotoxicity highlights an effective venom antidote
The box jellyfish Chironex fleckeri is extremely venomous, and envenoming causes tissue
necrosis, extreme pain and death within minutes after severe exposure. Despite rapid and
potent venom action, basic mechanistic insight is lacking. Here we perform molecular dissection
of a jellyfish venom-induced cell death pathway by screening for host components
required for venom exposure-induced cell death using genome-scale lenti-CRISPR mutagenesis.
We identify the peripheral membrane protein ATP2B1, a calcium transporting
ATPase, as one host factor required for venom cytotoxicity. Targeting ATP2B1 prevents
venom action and confers long lasting protection. Informatics analysis of host genes required
for venom cytotoxicity reveal pathways not previously implicated in cell death. We also
discover a venom antidote that functions up to 15 minutes after exposure and suppresses
tissue necrosis and pain in mice. These results highlight the power of whole genome CRISPR
screening to investigate venom mechanisms of action and to rapidly identify new medicines
Soil management and rroduction of alfisols in the semi-arid tropics. I. Modelling the effects of soil management on runoff and erosion
Techniques to simulate effects of surface cover and tillage on runoff and erosion are described. Data for 15 soil management treatments on an Alfisol in the semi-arid tropics, India, were used to modify existing procedures of runoff prediction using USDA runoff curve numbers. A relationship between surface cover and curve number was developed to account for the effects of surface cover on runoff. Impact of shallow or deep tillage was predicted using functions that relate curve number to cumulative rainfall since tillage. The derived relationships were applied to adjust curve number due to the effects of cover and tillage on a daily basis and were incorporated into the cropping systems model called PERFECT-IND.
Results of model validation showed that PERFECT-IND explained between 71 and 91% of the variation in daily runoff volumes. The model also provided accurate predictions of average annual runoff ranging from 33 to 217 mm for the 15 soil management treatments. Runoff was reduced to a much greater extent by surface cover compared with surface roughness. Surface cover reduced runoff curve number by a maximum of 35 units. The maximum reduction in curve number due to surface roughness was 5 units for shallow tillage and 10 units for deep tillage. Erosion predictions were acceptable but the lack of erosion data for all years in the experimental data limits the confidence in model output.
Model calibration and validation have provided a set of parameters that can be coupled with historical climate records to provide a long-term perspective of the effects of soil management on runoff and erosion. Keywords: simulation, model, runoff, water balance, curve number
Soil management and production of alfisols in the semi-arid tropics. III. Long-term effects on water conservation and production
A calibrated cropping systems model was used to provide long-term biophysical responses of various land managements at two differing semi-arid tropic environments in India. Organic based practices such as farmyard manure or straw amendments and perennial pastures reduced runoff by between 50 and 87%, and are optimum for in situ, water and soil conservation. A consequence of the reduced runoff was an increase in drainage below the root zone. Furthermore, the detrimental effects of cropping on high slopes and long slope lengths showed that it is not feasible to crop on slopes greater than 5%. Our study did not incorporate farmer preferences for land management, but the results can still be used as an integral part of decision making for optimum land management
Soil management and production of alfisols in the semi-arid tropics. IV. Simulation of decline in productivity caused by soil erosion
Maintenance of a productive soil base by minimizing soil erosion is vital to long-term crop production. In this study, a modelling approach is used to estimate the effects of soil erosion on productivity for a sorghum cropping system on an Alfisol in the semi-arid tropics of India. Predictions of erosion, runoff and yield decline due to erosion, for variations in initial soil depth, slope, tillage strategy and amendment treatment, are presented.
On average, soil depth decreased by 0.91 cm/year at Hyderabad for a 10% slope, 80 cm initial soil depth, shallow tillage at planting and no surface amendment. Rates of soil removal and subsequent yield decline were higher for shallower soils, steeper slopes and if management practices provided less surface cover during the crop. The productive life of the soil was less than 91 years for some soil depths, slope and management combinations. For other combinations, significant yield decline was predicted after 91 years of cropping.
The quantification of erosion-productivity relationships allows us to identify regions with a higher risk of degradation from soil erosion and to estimate the impact of various management options on long-term sustainability. Models provide a basis to focus research and a means of assessing alternative management strategies to preserve long-term production
- …