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College of Science and Engineering CSE publications Recent publications in Science and Engineering

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Recent publications in Science and Engineering

Bird, Michael I., Haig, Jordahna, Ulm, Sean, and Wurster, Christopher (2022) A carbon and nitrogen isotope perspective on ancient human diet in the British Isles. Journal of Archaeological Science, 137. 105516.
The stable carbon (δ13C) and nitrogen (δ15N) isotope composition of human bone collagen is increasingly used to investigate past mobility and subsistence strategies. This study presents a compilation of 1298 carbon and nitrogen isotope analyses of archaeological human bone collagen from the British Isles spanning much of the Holocene, along with a compilation of 4148 analyses of modern and ancient isotope analyses from the major marine and terrestrial dietary resources from the same region. We convert ancient human stable isotope data to modern diet equivalent (MDE) values for humans, and convert the isotope composition of ancient dietary items to modern tissue equivalent (MTE) isotope values. These conversions enable a direct comparison of ancient and modern datasets. Results for food groups (plants, grain, herbivores, omnivores, shellfish, freshwater fish and marine fish) show a remarkably broad range of δ13CMTE values from ∼-36 to −7‰ and δ15NMTE values from ∼-2 to +21‰ and we provide estimates for each food type that can be used in dietary reconstruction in the absence of site-specific data. We further show that there is no significant change in terrestrial stable isotope baseline values over the Holocene, with observed variability in baseline values due to local eco-physiological, edaphic and microclimatic factors. The range of values expressed in the human sample set from the beginning of the Iron Age is relatively tightly clustered with 50% of all human modern diet equivalent results falling within a ∼2‰ range in δ13CMDE values (−25.5 to −27.5‰) and a ∼3.5‰ range in δ15NMDE values from (+4‰ to +8‰). From the Iron Age to post-medieval times there is a consistent progressive shift to higher δ13CMDE and δ15NMDE values at the population level. This shift likely reflects a combination of successive innovations associated with food production, preservation and transport that enabled a broader cross-section of the population of the British Isles to incorporate a higher proportion of animal, and particularly marine protein, into their diets.

Collins, Brian (2021) Frequency of compound hot–dry weather extremes has significantly increased in Australia since 1889. Journal of Agronomy and Crop Science. (In Press)
There is high confidence that climate change has increased the probability of concurrent temperature-precipitation extremes, changed their spatial-temporal variations and affected the relationships between drivers of such natural hazards. However, the extent of such changes has been less investigated in Australia. Daily data spanning the period 1889-2019 (131 years) were extracted from SILO gridded dataset at 700 grid cells (1◦ × 1◦) across Australia to calculate annual and seasonal mean daily maximum temperature (MMT) and total precipitation (TPR). A nonparametric multivariate copula framework was adopted to estimate the return period of compound hot-dry (CHD) events based on an ‘And’ hazard scenario (hotter than a threshold ‘And’ drier than a threshold). CHD extremes were defined as years with joint return periods of longer than 25 years calculated over the period 1889-2019. Mann-Kendall nonparametric tests were used to analyse trends in MMT and TPR as well as in the frequency of univariate and CHD extremes. Results showed a general cooling-wetting trend over 1889-1989. Significant increasing trends were detected over 1990-2019 in the frequency and severity of hot extremes across the country while trends in dry extremes were mostly insignificant (and decreasing). A significant increase in the association between temperature and precipitation was identified at various temporal scales. While the frequency of CHD extremes was mostly stable over 1889-1989, it significantly increased between 1990 and 2019 at 44% of studied grid cells, mostly located in the north, south-east and southwest.

Laurance, William F. (2021) Reconciliation through ecological collaboration (commentary). Mongabay, 13 July 2021.
Peace is always kinder to the environment than war. But in the South Caucasus, restoring the environment together may help strengthen peace.

Chaturvedi, Iti, Cambria, Erik, Chen, Qian, and McConnell, Desmond (2021) Landmark calibration for facial expressions and fish classification. Signal, Image and Video Processing. (In Press)
This paper considers the automatic labeling of emotions in face images found on social media. Facial landmarks are commonly used to classify the emotions from a face image. However, it is difficult to accurately segment landmarks for some faces and for subtle emotions. Previous authors used a Gaussian prior for the refinement of landmarks, but their model often gets stuck in a local minima. Instead, the calibration of the landmarks with respect to the known emotion class label using principal component analysis is proposed in this paper. Next, the face image is generated from the landmarks using an image translation model. The proposed model is evaluated on the classification of facial expressions and also for fish identification underwater and outperforms baselines in accuracy by over 20%.

Schlaefer, Jodie A., Wolanski, Eric, Lambrechts, Jonathan, and Kingsford, Michael J. (2021) Behavioural and oceanographic isolation of an island-based jellyfish (Copula sivickisi, Class Cubozoa) population. Scientific Reports, 11. 10280.
Cubozoan jellyfish are classified as plankton despite the strong swimming and orientation abilities of cubomedusae. How these capabilities could affect cubozoan population structures is poorly understood. Medusae of the cubozoan Copula sivickisi can uniquely attach to surfaces with the sticky pads on their bells. Biophysical modelling was used to investigate the spatial scales of connectivity in a C. sivickisi population. When the medusae were active at night they could maintain their observed distribution on fringing reef if they attached to the reef when the current speed exceeded a moderate threshold. This behaviour facilitated the isolation of a C. sivickisi population on reefs fringing Magnetic Island, Queensland, Australia. Within this distribution, there was considerable within bay retention and medusae rarely travelled > 3 km. The few (< 0.1%) medusae lost from the island habitat were largely advected into open water and away from the mainland coast which lies 8 km from the island. Given that successful emigration is unlikely, the island population probably represents a stock that is ecologically distinct from any mainland populations. The cosmopolitan distribution of C. sivickisi could contain incipient or cryptic species given the small scales of connectivity demonstrated here.

Sharma, Choudhurimayum Pankaj, Chahal, Poonam, Kumar, Anil, Singhal, Saurabh, Sundriyal, Y. P., Ziegler, Alan, Agnihotri, Rajesh, Wasson, Robert J., Shukla, Uma Kant, and Srivastava, Pradeep (2021) Late Pleistocene-Holocene flood history, flood-sediment provenance and human imprints from the upper Indus River catchment, Ladakh Himalaya. GSA Bulletin. (In Press)
lThe Indus River, originating from Manasarovar Lake in Tibet, runs along the Indus Tsangpo Suture Zone (ITSZ) in Ladakh which separates the Tethyan Himalaya in the south from the Karakoram Zone to the north. Due to the barriers created by the Pir-Panjal ranges and the High Himalaya, Ladakh is located in a rain shadow zone of the Indian Summer Monsoon (ISM) making it a high-altitude desert. Occasional catastrophic hydrological events are known to endanger lives and properties of people residing there. Evidence of such events in the recent geologic past that are larger in magnitude than modern occurrences, are preserved along the channels. Detailed investigation of these archives is imperative to expand our knowledge of extreme floods that rarely occur on the human timescale. Understanding the frequency, distribution and forcing mechanisms of past extreme floods of this region are crucial to examine whether the causal agents are regional, global or both on long timescales. We studied the Holocene extreme flood history of the Upper Indus catchment in Ladakh using slack water deposits (SWDs) preserved along the Indus and Zanskar Rivers. SWDs here are composed of stacks of sand-silt couplets deposited rapidly during large flooding events in areas where a sharp reduction of flow velocity is caused by local geomorphic conditions. Each couplet represents a flood, the age of which is constrained using Optically Stimulated Luminescence (OSL) for sand and AMS 14C for charcoal specks from hearths. The study suggests occurrence of large floods during phases of strengthened ISM when the monsoon penetrated into arid Ladakh. Comparison with flood records of rivers draining other regions of the Himalaya and those influenced by the East Asian Summer Monsoon (EASM) indicates asynchronicity with the Western Himalaya that confirms the existing anti-phase relationship of the ISM-EASM occurred in the Holocene. Detrital zircon provenance analysis indicates that sediment transportation along the Zanskar River is more efficient than the main Indus channel during extreme floods. Post LGM human migration, during warm and wet climatic conditions, into the arid upper Indus catchment is revealed from hearths found within the SWDs.

Davis, Nicholas S., Rudge, Samuel L., and Kosov, Daniel S. (2021) Electronic statistics on demand: bunching, antibunching, positive, and negative correlations in a molecular spin valve. Physical Review B, 103 (20). 205408.
One of the long-standing goals of quantum transport is to use the noise, rather than the average current, for information processing. However, achieving this requires on-demand control of quantum fluctuations in the electric current. In this paper, we demonstrate theoretically that transport through a molecular spin valve provides access to many different statistics of electron tunneling events. Simply by changing highly tunable parameters, such as electrode spin polarization, magnetization angle, and voltage, one is able to switch between Poisson behavior, bunching and antibunching of electron tunnelings, and positive and negative temporal correlations. The molecular spin valve is modeled by a single spin-degenerate molecular orbital with local electronic repulsion coupled to two ferromagnetic leads with magnetization orientations allowed to rotate relative to each other. The electron transport is described via Born-Markov master equation and fluctuations are studied with higher- order waiting time distributions. For highly magnetized parallel-aligned electrodes, we find that strong positive temporal correlations emerge in the voltage range where the second transport channel is partially open. These are caused by a spin-induced electron-bunching, which does not manifest in the stationary current alone.

Baker, Stephanie, Xiang, Wei, and Atkinson, Ian (2021) Determining respiratory rate from photoplethysmogram and electrocardiogram signals using respiratory quality indices and neural networks. PLoS ONE, 16 (4). e0249843.
Continuous and non-invasive respiratory rate (RR) monitoring would significantly improve patient outcomes. Currently, RR is under-recorded in clinical environments and is often measured by manually counting breaths. In this work, we investigate the use of respiratory signal quality quantification and several neural network (NN) structures for improved RR estimation. We extract respiratory modulation signals from the electrocardiogram (ECG) and photoplethysmogram (PPG) signals, and calculate a possible RR from each extracted signal. We develop a straightforward and efficient respiratory quality index (RQI) scheme that determines the quality of each moonddulation-extracted respiration signal. We then develop NNs for the estimation of RR, using estimated RRs and their corresponding quality index as input features. We determine that calculating RQIs for modulation-extracted RRs decreased the mean absolute error (MAE) of our NNs by up to 38.17%. When trained and tested using 60-sec waveform segments, the proposed scheme achieved an MAE of 0.638 breaths per minute. Based on these results, our scheme could be readily implemented into non-invasive wearable devices for continuous RR measurement in many healthcare applications.

Tucker, Robert, Khatamifar, Mehdi, Lin, Wenxian, and McDonald, Kyle (2021) Experimental investigation of orientation and geometry effect on additive manufactured aluminium LED heat sinks under natural convection. Thermal Science and Engineering Progress, 23. 100918.
The continued adaptation of light-emitting diodes (LEDs) presents challenges for heat dissipation. LEDs are considered to be high power density devices, as such effective thermal management is imperative for extended usage. In this study, new design considerations such as adapting middle fin, fin height gradient towards the centre of the heat sink, along with fin perforations and a spiral cut out of the central pillar have been incorporated into heat sinks to assist convection. The heat sinks were manufactured out of aluminium alloy (AlSi10Mg) using the selective laser melting (SLM) method. The effects of orientation on the heat transfer of different heat sink geometries were experimentally studied under natural convection conditions. The performance of six different geometries with 6, 8 and 10 long fins (6LF, 8LF and 10LF) with and without middle fins were evaluated under three different heat flux conditions (471.57 , 943.14 and 1257.52 ) for 10 different orientation angles (0-90). The higher fin density heat sinks are found to have lower orientation dependency. The convective fluid flow of the higher fin density geometries is significantly hindered by the overlapping of thermal boundary layers. The increase in the Rayleigh number has the most significant effect on the 6LF heat sink. The overall Nusselt number correlations for the 6LF, 8LF and 10LF heat sinks with short fins are and , respectively. Removing short fins improved heat transfer rate for all heat sinks.

Dong, Liqiang, Lin, Wenxian, and Khatamifar, Mehdi (2021) Experimental study on the intrusion and stratification produced by confined laminar and turbulent round fountains. International Journal of Heat and Fluid Flow, 89. 108785. pp. 1-26.
In this paper, high-speed cameras and flow visualization techniques are used to investigate the behavior of the ‘fountain filling box’ flow resulted from releasing a round fountain in a homogeneous quiescent fluid in a cylindrical container over the ranges of 1.0⩽Fr⩽20.0,102⩽Re⩽1502, and 27.9⩽λ⩽48.75, where Fr,Re and λ are the Froude number, the Reynolds number, and the dimensionless radius of the container, respectively, with λ non-dimensionalized by the fountain source radius. The results show the transition of the flow behavior of the fountain and its secondary flows (i.e., the intrusion, reversed flow and stratification) from laminar to turbulent with increasing Fr, and turbulence of the flow strengthened with increasing Re. For intermediate (e.g., Fr=3.0) and forced turbulent fountains (e.g., Fr=5.0, 8.0, 15.0) with a specific λ, the non-dimensionalized time-scale for the intrusion front to impinge upon the sidewall, τw, is nearly constant for Re≳500. This is because the secondary intrusion flow is dominated by the wall-jet and buoyancy-inertial regimes where the non-dimensionalized intrusion front velocity, vi, is only time-dependent (vi~τ-1/2) or time-dependent but also under the influence of Fr (vi~Fr-1/2τ-1/4). However, τw for the fountains of Re≲204 is significantly different, which may result from the change in the dominant regime for the intrusion or the interaction between the upflow, downflow of the fountain and the ambient fluids. Furthermore, it is found that the non-dimensionalized quasi-steady development rate of the stratification, vs, increases with Fr, but decreases with Re, since the diffusion effect is suppressed with decreasing Fr or increasing Re.

Clements, Kendall D., German, Donovan P., Piche, Jacinthe, Tribollet, Aline, and Choat, John Howard (2021) Integrating ecological roles and trophic diversification on coral reefs: multiple lines of evidence identify parrotfishes as microphages. Biological Journal of the Linnean Society. (In Press)
Coral reef ecosystems are remarkable for their high productivity in nutrient-poor waters. A high proportion of primary production is consumed by the dominant herbivore assemblage, teleost fishes, many of which are the product of recent and rapid diversification. Our review and synthesis of the trophodynamics of herbivorous reef fishes suggests that current models underestimate the level of resource partitioning, and thus trophic innovation, in this diverse assemblage. We examine several lines of evidence including feeding observations, trophic anatomy, and biochemical analyses of diet, tissue composition and digestive processes to show that the prevailing view (including explicit models) of parrotfishes as primary consumers of macroscopic algae is incompatible with available data. Instead, the data are consistent with the hypothesis that most parrotfishes are microphages that target cyanobacteria and other protein-rich autotrophic microorganisms that live on (epilithic) or within (endolithic) calcareous substrata, are epiphytic on algae or seagrasses, or endosymbiotic within sessile invertebrates. This novel view of parrotfish feeding biology provides a unified explanation for the apparently disparate range of feeding substrata used by parrotfishes, and integrates parrotfish nutrition with their ecological roles in reef bioerosion and sediment transport. Accelerated evolution in parrotfishes can now be explained as the result of (1) the ability to utilize a novel food resource for reef fishes, i.e. microscopic autotrophs; and (2) the partitioning of this resource by habitat and successional stage.

Lal, Alvin, and Datta, Bithin (2021) Optimal pumping strategies for the management of coastal groundwater resources: application of Gaussian Process Regression metamodel-based simulation-optimization methodology. ISH Journal of Hydraulic Engineering. (In Press)
The present study utilizes a coupled simulation-optimization (S-O) methodology to develop a multi-objective management strategy for a coastal aquifer system. The aim of the multi-objective management model is to maximize pumping from freshwater wells (FWs) and minimize pumping from the barrier wells (BWs), while keeping salinity concentration in the aquifer within pre-specified limits (optimization constraint). To achieve computational feasibility of the management model, the numerical simulation model is substituted by the relatively new Gaussian Process Regression (GPR) metamodels. The GPR models are used to approximate coastal aquifer responses to variable transient pumping patterns from FWs and BWs. Prediction capabilities of the developed GPR metamodels are quantified using standard statistical parameters. Once trained and validated, the GPR metamodels are coupled to a multi-objective genetic algorithm optimization model and used to prescribe optimal groundwater pumping patterns. The outcomes of this study establishes the potential applicability of the GPR metamodel-based S-O model for developing sustainable coastal groundwater management strategies, which can utilize accurate and efficient prediction of management strategy impacts on the saltwater intrusion (SI) process when the optimal management policy development is based on the trained metamodel predictions. Once implemented, the developed strategy can help in controlling SI in coastal aquifer systems.

Staunton, Kyran M., Crawford, Jacob E., Liu, Jianyi, Townsend, Michael, Han, Yu, Desnoyer, Mark, Howell, Paul, Xiang, Wei, Burkot, Thomas R., Snoad, Nigel, and Ritchie, Scott A. (2021) A low-powered and highly selective trap for male Aedes (Diptera: Culicidae) surveillance: the male Aedes sound trap. Journal of Medical Entomology. (In Press)
As Aedes aegypti (Linnaeus, Diptera: Culicidae) expands its global distribution and vectors a range of debilitating arboviruses there is an increased need for enhanced mosquito surveillance. Consequently, we developed a Male Aedes Sound Trap (MAST) that requires minimal power and is highly species-specific. Two different versions of the MAST were developed, one that uses synthetic pyrethroid to kill captured mosquitoes (MAST Spray) and another which has an internal divider to create a killing chamber in which a sticky panel can be placed to capture mosquitoes (MAST Sticky). We compared weekly capture rates of male Ae. aegypti and bycatch from the two MAST versions to those from BG-Sentinel (BGS) traps and Sound-producing BG-Gravid Aedes Traps (SGATs) throughout Cairns, northern Australia. Weekly mean male Ae. aegypti catches did not significantly differ between trap types. However, the rate of positive weekly detections of male Ae. aegypti was lower for the MAST Sticky than the other three trap types. The MASTs sampled significantly fewer mosquitoes other than male Ae. aegypti, than either the BGS trap or the SGAT. Also, the MASTs and SGATs all caught significantly less non-Culicidae bycatch than the BGS traps. Consequently, we have developed a versatile male Ae. aegypti trap which is potentially of great benefit to Ae. aegypti surveillance programs.

MacKeracher, Tracy, Mizrahi, Me'ira, Bergseth, Brock, Chit Maung, Khin May, Khine, Zin Lin, Phyu, Ei Thal, Simpfendorfer, Colin A., and Diedrich, Amy (2021) Understanding non-compliance in small-scale fisheries: shark fishing in Myanmar's Myeik Archipelago. Ambio, 50. pp. 572-585.
Achieving fisheries compliance is challenging in contexts where enforcement capacity is limited and the incentives for rule-breaking are strong. This challenge is exemplified in Myanmar, where an active shark fishery exists despite a nationwide ban on targeted shark fishing. We used the Kipling method (5W1H) to gather a complete story of non-compliance in five small-scale fishing communities in the Myeik Archipelago. Among 144 fishers surveyed, 49% were aware of the nationwide ban. Shark fishers (24%) tended to be younger individuals who did not own a boat and perceived shark fishing to be prevalent. Compliant fishers were motivated by a fear of sharks and lack of capacity (equipment, knowledge), whereas food and income were cited as key motivations for non-compliance. The results of our study emphasize that in resource-dependent communities, improving compliance for effective shark conservation may require addressing broader issues of poverty, food security and the lack of alternatives.

Thiault, Lauric, Curnock, Matthew I., Gurney, Georgina G., Heron, Scott F., Marshall, Nadine A., Bohensky, Erin, Nakamura, Nao, Pert, Petina L., and Claudet, Joachim (2021) Convergence of stakeholders' environmental threat perceptions following mass coral bleaching of the Great Barrier Reef. Conservation Biology, 35 (2). pp. 598-609.
Managing human use of ecosystems in an era of rapid environmental change requires an understanding of diverse stakeholders' behaviors and perceptions to enable effective prioritization of actions to mitigate multiple threats. Specifically, research examining how threat perceptions are shared or diverge among stakeholder groups and how these can evolve through time is increasingly important. We investigated environmental threat perceptions related to Australia's Great Barrier Reef and explored their associations before and after consecutive years of mass coral bleaching. We used data from surveys of commercial fishers, tourism operators, and coastal residents (n = 5254) conducted in 2013 and 2017. Threats perceived as most serious differed substantially among groups before bleaching but were strongly aligned after bleaching. Climate change became the most frequently reported threat by all stakeholder groups following the coral bleaching events, and perceptions of fishing and poor water quality as threats also ranked high. Within each of the 3 stakeholder groups, fishers, tourism operators, and coastal residents, the prioritization of these 3 threats tended to diverge in 2013, but convergence occurred after bleaching. These results indicate an emergence of areas of agreement both within and across stakeholder groups. Changes in perceptions were likely influenced by high-profile environmental-disturbance events and media representations of threats. Our results provide insights into the plasticity of environmental-threat perceptions and highlight how their convergence in response to major events may create new opportunities for strategic public engagement and increasing support for management.

Rowell, Misha K., and Rymer, Tasmin L. (2021) Growth and behavioural development of the fawn-footed mosaic-tailed rat (Melomys cervinipes). Australian Mammalogy, 43 (3). pp. 330-334.
The fawn-footed mosaic-tailed rat (Melomys cervinipes) is a common Australian rainforest rodent; however, little is known about the growth or behavioural development of individuals of this species. We raised mosaic-tailed rats in captivity to assess the growth and behavioural development of pups from birth until weaning. Pups developed quickly compared with some other Australian species, and there were no significant differences in growth between males and females, except for anogenital distance. The auditory meatus was open by Postnatal Day 5, and eyes were fully opened by Postnatal Day 9. All behaviours, including righting, locomotion, negative geotaxis, climbing and grip reflex, were fully developed by Postnatal Day 6. These results suggest that mosaic-tailed rats are semiprecocial in their physical and behavioural development compared with some native Australian rodent species that are found in arid environments. As females produce few, relatively well-developed young, the population has a low intrinsic rate of natural increase. This may, however, be offset by mosaic-tailed rats producing more litters per year. Understanding the biology of mosaic-tailed rats in general could provide insights into how rarer precocial species might struggle to increase in population size under increasing disturbances.

Hopkins, Jaimie M., Higgie, Megan, and Hoskin, Conrad J. (2021) Calling behaviour in the invasive Asian house gecko (Hemidactylus frenatus) and implications for early detection. Wildlife Research, 48 (2). pp. 152-162.
Context. Acoustic communication is common in some animal groups, with an underlying function typically associated with mating or territoriality. Resolving the function of calls is valuable both in terms of understanding the fundamental biology of the species and, potentially, for applied reasons such as detection. Early detection is a key step in exclusion and eradication of invasive species, and calling behaviour can be used in this regard. The Asian house gecko (Hemidactylus frenatus) is one of a minority of lizards that uses acoustic communication. However, despite how conspicuous the call is, its function remains poorly resolved. It is also one of the world's most invasive species, with exclusion via early detection being the key form of control. Aims. The aim was to resolve calling patterns and underlying function of the loud, multiple-chirp call ('chik, chik, chiky') in H. frenatus, in the context of using the results for developing effective methods for detection of new and establishing populations. Methods. The calls of wild H. frenatus were recorded to assess peaks in calling activity. Also, laboratory experiments were performed to determine which individuals call, what causes them to call and the degree of call variation among individuals. Key results. Assessment of calling behaviour in the wild revealed greater calling activity in warmer months, and five- to 10-fold peaks in calling activity at sunset and 30 min before sunrise. Laboratory experiments revealed that calls were uttered exclusively by males and primarily by adults (although juveniles can call). Males called more when they were paired with females as opposed to other males. Calls differed among geckos, including the expected negative correlation between dominant frequency and body size. Conclusions. The results suggest that the multiple-chirp call functions as a territory or sexual broadcast by males, perhaps containing information such as body size. Implications. Detection success can be maximised by performing acoustic surveys (by human or machine) during the calling peaks at 30 min before sunrise and at sunset, particularly during warm nights. However, these surveys will only be effective for detecting adult males. The results also suggest that good quality recordings could potentially be used to identify individual geckos.

Ziegler, Alan D., Lim, H.S., Wasson, Robert J., and Williamson, Fiona C. (2021) Flood mortality in SE Asia: can palaeo‐historical information help save lives? Hydrological Processes, 35 (1). e13989.
[Excerpt] Asia is one of the world's most flood-prone regions by many metrics: high flood magnitudes, frequency, severity; the number countries affected, the area of inundation; the number of people at risk; and importantly, flood-related fatalities (AIR, 2014; Luo, Maddoks, Iceland,Ward, & Winsemius, 2015; Table 1). With respect to mortality, nearly all the countries with more than 5,000 flood-related deaths since 1985 are from Asia (11 of 13; Table 1; Figure 1). As we write this commentary, flooding associated with tropical storm Nangka has caused more than 40 deaths in Laos, Cambodia, and Vietnam(Floodlist, 2020).

Brown, Colin, Behrendt, Karl, Ping, Li, Guanghua, Qiao, Bennett, Jeff, Bao, Zhang, Addison, Jane, Kemp, David, Guodong, Han, and Jing, Zhang (2021) Refining China's grassland policies: an interdisciplinary and ex-ante analysis. The Rangeland Journal, 42 (6). pp. 435-445.
China is about to embark on a new round of grassland policies as part of its 14th Five-Year-Plan. While current grassland policies have generally been perceived positively in arresting widespread grassland degradation, concerns have arisen that the current policies may not be effective in achieving the desired reduction in livestock numbers. Furthermore there are concerns the incentive based payments that are part of these policy programs may not reflect herder opportunity costs or the marginal environmental benefits of the program with associated issues of herder satisfaction and compliance. Changes to current policy settings are being considered in response to these concerns. This paper reports on an interdisciplinary and ex-ante analysis of alternative policy settings affecting grazing and livestock management in terms of their environmental impacts, net social benefits and other impacts. The analysis finds that a bundle of instruments involving both positive and negative herder incentives is needed if desired stocking rates are to be achieved. The impact on herder incomes, both positive and negative depending on the grassland biome, along with transaction costs of implementing the policies, have the most influence on net social benefits.

Yeeles, Peter, Strain, Angela, Lenancker, Pauline, and Lach, Lori (2021) Low reduction of invasive ant colony productivity with an insect growth regulator. Pest Management Science. (In Press)
Background Insect growth regulators (IGRs) generally are considered to have safer eco-toxicological profiles than the more commonly used neurotoxins and metabolic inhibitors, and are extremely effective against several insect groups, including some invasive ant species. However, use of an IGR product in a large-scale eradication program for a widespread invasive ant (Anoploepis gracilipes; yellow crazy ant) was ineffective. We tested the IGR in question (active ingredient: (S)-methoprene) on A. gracilipes colonies in a laboratory environment to evaluate efficacy. Results We found that treatment with (S)-methoprene resulted in lower egg production with subsequently decreased numbers of larvae, pupae, and workers over the 135 days of the experiment. None of the treated colonies died, and the number of worker ants in treated colonies was 36% of that seen in control colonies 135 days post-treatment. Treated queen egg production was 39% lower than queens in control colonies, but we saw no effect of treatment on the internal physiology of dissected queens. Treatment had no effect on worker activity levels. Conclusion Our results show that although (S)-methoprene treatment reduced production of larvae, pupae and workers in treated colonies, the magnitude of reduction was lower than might be expected considering the responses of other species against which this IGR has been tested. Our findings highlight a need for testing species-specific responses to IGR-based insecticides in a controlled environment, before broad-scale field applications that could result in suboptimal management of the target species.

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