Recent publications in Science and Engineering
Solution-processing of organic light-emitting diode films has potential advantages in terms of cost and scalability over vacuum-deposition for large area applications. However, solution processed small molecule films can have lower overall device performance. Here, novel molecular dynamics techniques are developed to enable faster simulation of solvent evaporation that occurs during solution processing and give films of thicknesses relevant to real devices. All-atom molecular dynamics simulations are then used in combination with kinetic Monte Carlo transport modeling to examine how differences in morphology stemming from solution or vacuum film deposition affect charge transport and exciton dynamics in films consisting of light-emitting bis(2-phenylpyridine)(acetylacetonate)iridium(III) [Ir(ppy)2(acac)] guest molecules in a 4,4′-bis(N-carbazolyl)biphenyl host. While the structures of the films deposited from vacuum and solution were found to differ, critically, only minor variations in the transport properties were predicted by the simulations even if trapped solvent was present.
Massault, Cecile, Jeffrey, Cara, Jones, David B., Barnard, Roger, Strugnell, Jan M., Zenger, Kyall R., and Jerry, Dean R. (2022) Non-invasive DNA collection for parentage analysis for bivalves: A case study from the silver-lipped pearl oyster (Pinctada maxima). Aquaculture, 552. 738036.
Due to the high revenues generated by the pearl industry, interest in developing breeding programs is increasing. The traditional approach for collecting DNA for pedigree analyses in breeding programs for the silver-lipped pearl oyster (Pinctada maxima) involves tissue excision from the muscular foot and/or mantle. Tissue excision causes injury and stress to the animal, and can lead to reduced growth efficiency, bacterial infection and subsequent mortality when oysters are returned to the non-sterile marine environment. The approach of swabbing tissue to collect cells for DNA analyses offers a potential non-invasive and rapid method but has not been reported previously for pearl oysters; particularly where DNA is destined for a high-throughput genotype-by-sequencing (GBS) single nucleotide polymorphism (SNP) genotyping platform. To evaluate the potential of swabbing as a method to collect DNA for downstream GBS SNP genotyping under commercial farming conditions, 29 broodstock pearl oysters were swabbed with two different swab brushes (a stiff and soft brush). Concentration of the extracted DNA from swabs was found to meet requirements for genotyping (44 to 59 ng/μL) and 260/280 ratios were in the acceptable range for DNA purity (1.9–2.2). SNP genotype calls derived from swab samples were highly correlated with those derived from tissue excised from the same oyster (mean of 0.97 ± 0.04 for soft bristle – mean of 0.98 ± 0.02 for stiff bristle). Finally, we evaluated the performance of swabbing under a commercial breeding program scenario, whereby 923 spat were genotyped and 18 months later 1927 pearl oysters from the same commercial cohort were swabbed to determine parental contributions for the cohort at the two time periods. Results demonstrated that the swab method is reliable for collecting sufficient quantity and quality of DNA for genome-wide SNP genotyping enabling accurate pedigree reconstruction. This study validated the efficiency of the use of the swab technique to collect DNA for routine parentage assignment, while limiting the adverse effects of destructive tissue sampling for commercial use and/or for the development of breeding programs.
Moynier, Frédéric, Merland, Ariane, Rigoussen, Dimitri, Moureau, Julien, Paquet, Marine, Mahan, Brandon, and LeBorgne, Marie (2022) Baseline distribution of stable copper isotope compositions of the brain and other organs in mice. Metallomics, 14 (5). mfac017.
Copper (Cu) stable isotopes are useful for understanding pathways and tracing changes in Cu homeostasis, such as those induced by various diseases (e.g. liver cirrhosis, numerous forms of cancer, and neurodegenerative diseases). However, this utility relies on a baseline understanding of the natural distribution of Cu isotopes between organs of healthy organisms, which is not well-known at present. Here, the distribution of natural Cu isotopes in the brain, liver, red blood cells, plasma, kidneys, and muscle of 14 mice (7 males and 7 females) from three different genetic backgrounds is assessed. We show that the Cu isotopic composition of most mouse organs is isotopically distinct from one another. The most striking feature is the heavy isotope enrichment of the kidney (δ65Cu = 1.65 ± 0.06‰, 2SE), brain (δ65Cu = 0.87 ± 0.03‰, 2SE) and liver (δ65Cu = 0.71 ± 0.24‰, 2SE) compared to blood components, i.e. red blood cells (RBCs) (δ65Cu = 0.30 ± 0.06‰, 2SE), and plasma (δ65Cu = –0.61 ± 0.08‰, 2SE), with δ65Cu being the per mil deviation of the 65Cu/63Cu ratio from the NIST SRM 976 standard. Differences in genetic background do not appear to affect the isotopic distribution of Cu. Interestingly, male and female mice appear to have different Cu concentrations and isotopic compositions in their brain, plasma, muscle, and RBC. By demonstrating that organs have distinct isotopic compositions, our study reinforces the notion that Cu stable isotopes can be used to trace changes in homeostasis in diseases affecting Cu distribution, such as Alzheimer's disease, liver cancer, and possible chronic kidney failure.
Clements, Kendall D., German, Donovan P., Piche, Jacinthe, Tribollet, Aline, and Choat, John Howard (2022) 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.
Chaitae, Apinya, Gordon, Iain J., Addison, Jane, and Marsh, Helene (2022) Protection of elephants to sustainable use of ivory in Thailand. Oryx. (In Press)
The elephant has deep cultural significance in Thailand and for the Thai people. The development of legal protection for Thai elephants reflects concerns about both human livelihoods and elephant conservation. Thus, the legal status of privately-owned domesticated, or captive Asian elephants, differs from that of wild Asian elephants, a situation that has consequences for the lawful use of ivory from domesticated animals. Prior to 2015, the lack of comprehensive measures to control the Thai ivory market enabled the laundering of illegally-sourced ivory through the country. The 2015 legal reforms of the Thai Government: 1) introduced strict controls over the possession and domestic trade of ivory from domesticated Asian elephants, and 2) aligned the protection of African elephants and their ivory with the CITES Convention. Nonetheless, the sustainability of the Thai ivory trade remains disputed, and international pressure to close the commercial trade in domestic ivory persists. This paper reviews this complex situation to inform future reforms. Consolidation of related laws would ease the enforcement tasks of officers and facilitate the compliance of stakeholders. Use of an electronic database would enhance the monitoring of ivory flow, as well as aid the implementation and enforcement of laws. This situation is a valuable example of the tensions between national and international attempts to conserve species important in wildlife trade.
Montesinos, Daniel (2022) Fast invasives fastly become faster: invasive plants align largely with the fast side of the plant economics spectrum. Journal of Ecology, 110 (5). pp. 1010-1014.
1. Invasive plants generally align with the fast side of the plant's trait economics spectrum, characterized by fast nutrient acquisition, growth and reproduction. However, there are numerous and notable exceptions, including woody invasives. 2. The generalization that invasives are fast is driven by the high occurrence of invasive ruderal species colonizing nutrient-rich disturbed habitats, a consequence of anthropogenic disturbance usually going hand-in-hand with biological introductions. 3. Successful invasive plans have shown a remarkable ability to rapidly adapt to the new regions where they are introduced. These changes predominantly involve increased resource acquisition, growth and reproduction, aligning them even further with the fast side of the plant economics spectrum. 4. Common garden experiments with invasive model systems provide valuable insights about the speed and direction of adaptive responses to different climates, helping us to predict general plant responses to global change. 5. Synthesis. Invasive plant species commonly present fast nutrient acquisition, growth and reproduction, but this general pattern is mostly driven by ruderal species. Still, common garden experiments comparing populations from distant world regions show a clear trend for already fast invasive plants to rapidly adapt towards even faster traits in their non-native regions.
Malekzadeh, M., Sivakugan, Siva, and Clark, M.W. (2022) Effect of aqueous environment on sedimentation of dredged mud and kaolinite. Marine Georesources & Geotechnology, 40 (2). pp. 171-180.
Port development results in production of large quantities of dredged marine sediments. Once dredged, sediments often have high water contents and are pumped to near-shore or in-water bunded marine impoundments for port expansion. However, dredged material disposal to freshwater onshore or empty impoundments typically changes sedimentation conditions that may change the effective grain-size distribution, mineral specific surface areas, settling particle orientations, resulting in settling rate changes. Salinity, temperature, water content, mineralogy, filling rate, and organic matter content may also influence sediment settlement and resulting consolidation. This study investigates the effect of salinity and sediment mineralogy on sediment settlement behaviour when deposited in saltwater, freshwater, or to empty ponds. For this purpose, slurries of dredged mud and kaolinite with water contents of 1.7 times their liquid limit were prepared and disposed into a series of 1000 mm long, 50 mm wide, and 500 mm high settlement columns. Result shows that the sediments settle faster in saltwater than freshwater or air, through divalent surface complexation and flocculation provided by seawater Ca and Mg. However, this is true if the salinity remains below 10 PSU, but the mixed mineral dredge spoil ultimately provides the densest sediment and lowest water sediment interface.
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 (2022) Late Pleistocene-Holocene flood history, flood-sediment provenance and human imprints from the upper Indus River catchment, Ladakh Himalaya. GSA Bulletin, 134. 1-2. pp. 275-292.
The 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.
Collins, Brian (2022) 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.
Han, Kang, Xiang, Wei, Wang, Eric, and Huang, Tao (2022) A novel occlusion-aware vote cost for light field depth estimation. IEEE Transactions on Pattern Analysis and Machine Intelligence. (In Press)
Conventional light field depth estimation methods build a cost volume that measures the photo-consistency of pixels refocused to a range of depths, which works well in most regions but usually generates blurry edges in the estimated depth map due to occlusions. Existing occlusion handling methods rely on complex edge-aided processing and post-refinement, and this reliance limits the resultant depth accuracy and impacts on the computational performance. In this paper, we propose a novel occlusion-aware vote cost (OAVC) which is able to accurately preserve edges in the depth map. Instead of using photo-consistency as an indicator of the correct depth, we construct a novel cost from a new perspective that counts the number of refocused pixels whose deviations from the central-view pixel is less than a small threshold, and utilizes that number to select the correct depth. The pixels from occluders are thus excluded in determining the correct depth. Without the use of any explicit occlusion handling methods, the proposed method can inherently preserve edges and produces high-quality depth estimates. Experimental results show that the proposed OAVC outperforms state-of-the-art light field depth estimation methods in terms of depth estimation accuracy and the computational performance.
Walshe, Rachael (2022) Book review of "Food, Senses and the City" by Ferne Edwards, Roos Gerritsen and Grit Wesser (eds). London, UK, Routledge, 2021. ISBN: 978-0-367-45823-2. Australian Geographical Studies, 60 (1). pp. 196-198.
[Extract] Food, Senses and the City explores how sensorial experiences of food create new meanings and understandings of the city. In the process, the book extends conversations about the role food plays in shaping our identities (Baker, 2004; Bourdieu, 1984; Law, 2001; Sutton, 2010).
Vuppaladadiyam, Arun K., Antunes, Elsa, Vuppaladadiyam, Varsha S.S., Shehzad, Farrukh, Somasundaram, Murugavelh, Memon, Muhammad Z., Song, Qingbin, Dong, Weiguo, and Duan, Hubao (2022) Discernment of synergy during the co-pyrolysis of lipid-extracted microalgae and digested municipal solid waste: a thermogravimetric–mass spectrometric study. Journal of Chemical Technology and Biotechnology, 97 (2). pp. 490-500.
BACKGROUND: The current study investigated the co-pyrolysis nature of biomasses, gas yields, kinetics and thermodynamics of Chroococcus sp. (CC), digested municipal solid waste (DMSW) and their mixtures using thermogravimetric analysis and mass spectrometry. RESULTS: Thermogravimetric/differential thermogravimetric analysis indicated three major weight loss stages: dehydration (50–150 °C), thermal degradation of structural components (150–550 °C) and char decomposition (550–800 °C). The gases released during the process mainly contained CO, CH4, CO2 and H2 as main components. Also, with an increase in the composition of CC, the hydrogen yields were noticed to increase. Model-free isoconversional methods, the Kissinger–Akahira–Sunose and Friedman methods, were considered to identify the activation energy. The kinetic results showed that an increase in the percentage of CC in the mixture lowered the activation energy. The activation energies recorded for CC, DMSW, CD-1, -2 and -3 were 282.11, 202.55, 210.54, 145.46 and 139.98 kJ mol−1, respectively. CONCLUSIONS: Thermodynamic and kinetic analysis for CC, DMSW and their mixtures can be effectively used for reactor design and process optimization for similar types of waste materials. © 2021 Society of Chemical Industry (SCI).
Smith, Calvin, Hill, Blair, Wheatley, Greg, Masoudi Nejad, Reza, and Sina, Nima (2022) Fatigue reliability assessment of the new design of rear suspension system of the JCU motorsport car. Structures, 36. pp. 473-481.
The objective of this paper is to calculate fatigue reliability of the new design of rear suspension system of the James Cook University (JCU) motorsports 2nd generation vehicle for the formula society of automotive engineers (FSAE) competition. Also, this paper entails preliminary and detailed design stages for the rear suspension ensuring coherence with the FSAE rules, and carrying out details theoretical and numerical analysis throughout and iterative design process. The objective of this paper to conceive and design a fully functioning rear suspension system that includes uprights, wishbones, rockers, dampers and shock-absorbers. The fabrication of specific suspension components, if not all, is a major goal of this paper. Then, in order to maintain the minimum amount of fatigue reliability at a certain value, the number of variable components is defined at each time of inspection. The results showed that reducing the time interval between periodic inspections and increasing the number of replaced components at each stage of the inspection can keep the system reliability as expected.
Rowe, Melissah, van Oort, Aaabel, Brouwer, Lyanne, Lifjeld, Jan T., Webster, Michael S., Welklin, Joseph F., and Baldassarre, Daniel T. (2022) Sperm numbers as a paternity guard in a wild bird. Cells, 11 (2). 231.
Sperm competition is thought to impose strong selection on males to produce competitive ejaculates to outcompete rival males under competitive mating conditions. Our understanding of how different sperm traits influence fertilization success, however, remains limited, especially in wild populations. Recent literature highlights the importance of incorporating multiple ejaculate traits and pre-copulatory sexually selected traits in analyses aimed at understanding how selection acts on sperm traits. However, variation in a male’s ability to gain fertilization success may also depend upon a range of social and ecological factors that determine the opportunity for mating events both within and outside of the social pair-bond. Here, we test for an effect of sperm quantity and sperm size on male reproductive success in the red-back fairy-wren (Malurus melanocephalus) while simultaneously accounting for pre-copulatory sexual selection and potential socio-ecological correlates of male mating success. We found that sperm number (i.e., cloacal protuberance volume), but not sperm morphology, was associated with reproductive success in male red-backed fairy-wrens. Most notably, males with large numbers of sperm available for copulation achieved greater within-pair paternity success. Our results suggest that males use large sperm numbers as a defensive strategy to guard within-pair paternity success in a system where there is a high risk of sperm competition and female control of copulation. Finally, our work highlights the importance of accounting for socio-ecological factors that may influence male mating opportunities when examining the role of sperm traits in determining male reproductive success.
Tavares, Silvia G., Sellars, David, Dupre, Karine, and Mews, Gregor H. (2022) Implementation of the New Urban Agenda on a local level: an effective community engagement methodology for human-centred urban design. Journal of Urbanism. (In Press)
This paper explores multi-method community engagement activities used to quickly and effectively produce an action plan based on city stakeholders' perceptions and wishes. A UN-Habitat Urban Thinkers Campus (UTC), focused on promoting urban liveability, adopted a methodology aimed to effectively engage participants through the completion of urban diaries prior to the event. Engagement with participants was further enhanced through urban labs and discussions culminating in a Design Sprint, producing meaningful action statements. The methodology was aimed at capturing impressions, concerns and roles of each stakeholder group in producing human-centred urban environments. Results suggest the adopted methodology was successful in producing a clear set of tangible action statements, identified as potentially generating high impact and requiring low effort to be implemented. These readily applicable actions were compiled by the end of a single but intense workday.
Kamash, Walid El, Naggar, Hany El, To, Peter, and Sivakugan, Nagaratnam (2022) The effect of long-term consolidation on foundations underpinned by micropiles in soft clay. Ain Shams Engineering Journal, 13 (1). 101487.
So far insufficient research has been done on the long-term behavior of micropiles embedded in a clay medium, even though this has a significant influence on the expected total settlement. This paper considers a square foundation placed on a clay bed and tested under vertical loads until the clay reached its bearing capacity. Subsequently, the plate was underpinned with four micropiles, and the load test was repeated. These test data were used to validate the coupled hydraulic-mechanical three-dimensional finite difference model presented in this paper. In the numerical modelling, four different load transfer scenarios were considered to simulate different approaches to adding floors to an existing building. Consolidation periods of zero months, six months, and five years between the application of the load due to the existing building, and the application of loads due to additional storeys were considered. The six-month period represents a short-term, and the five-year period a long-term scenario. Following the first consolidation period and the application of loads representing additional storeys, a second consolidation period was implemented, such that the combined length of the two consolidation periods was five years. In this study, the results showed that the installation of micropiles immediately after the completion of existing floors is most successful in controlling the settlement of additional floors later on.
Lei, Peng, Zhou, Ying, Li, Bei, Liu, Yang, Dong, Chuan, and Shuang, Shaomin (2022) Gold/palladium–polypyrrole/graphene nanocomposites for simultaneous electrochemical detection of DNA bases. ACS Applied Nano Materials, 5 (1). pp. 1635-1643.
The unique combination of DNA bases is essential for storing genetic information. A reliable and accurate electrochemical sensor based on a gold/palladium−polypyrrole/graphene nanocomposite (Au/Pd−PPy/GR) has been prepared to individually and simultaneously detect guanine (G), adenine (A), thymine (T), and cytosine (C). The bimetallic nanomaterial (Au/Pd−PPy) is used to enhance the sensing performance of DNA bases, and the GR could further increase the electroactive area and amplify the electrochemical response. As expected, the electrochemical sensor shows excellent electrocatalytic activity with well-separated current responses at 0.704 V (G), 0.976 (A), 1.164 (T), and 1.348 V (C). The prepared sensor exhibits the linear range of 1−350 μM for G, 5−300 μM for A, 20−900 μM for T, and 10−700 μM for C. The developed device is also demonstrated as an excellently sensitive and highly selective sensor to identify the four bases in calf thymus DNA, which provides the application of electrochemical sensors in bioscience.
Chen, Jun Yu, Zeng, Chaoshu, and Cobcroft, Jennifer M. (2022) Digestive system ontogeny and the effects of weaning time on larval survival, growth and pigmentation development of orchid dottyback Pseudochromis fridmani. Aquaculture, 549. 737737.
Although live prey remain essential for most marine finfish larviculture, the larvae or young juveniles are ultimately weaned onto formulated feeds at foodfish and ornamental fish hatcheries. Understanding the development of larval digestive capabilities is crucial for optimizing weaning success. The present study used the digestive system ontogeny to interpret the effects of different weaning times on larval rearing of orchid dottyback Pseudochromis fridmani, a marine ornamental fish species. The study documented the ontogenetic digestive system development of P. fridmani larvae from hatching to 40 days post-hatching (DPH). The histological analysis showed that as a demersal spawning species, the newly hatched P. fridmani larvae possessed advanced gut development which allowed the onset of exogenous feeding soon after hatching. Most major larval gut morphological changes were completed by 13 DPH; however, the stomach and gastric glands were first observed between 32 and 36 DPH. At this stage, P. fridmani larvae were expected to acquire substantially improved digestive capabilities, and were likely capable of digesting formulated feed. In the subsequent experiment, P. fridmani larvae were weaned onto formulated feed from 20, 23, 26, 29, or 32 DPH over a three-day period of co-feeding with enriched Artemia; the control group were exclusively fed enriched Artemia until the end of experiment. The timing of weaning significantly affected the larval growth and pigmentation development rather than survival (mean: 44-64%). P. fridmani larvae weaned later tended to grow larger, and the control group grew significantly larger in length than all weaning treatments (p < 0.05). Interestingly, at the end of the experiment (40 DPH), none of larvae from the control obtained adult-type pigmentation despite their larger size. In contrast, the introduction of formulated feed appeared to stimulate pigmentation development in P. fridmani individuals with a clear trend of higher pigmentation completion by 40 DPH (mean: 62-97%) with earlier weaning. Overall, this study demonstrated that P. fridmani larvae could be weaned onto formulated feed from as early as 20 DPH, before the stomach and gastric glands were fully developed; indeed, the timing of adult-type pigmentation change in P. fridmani was also advanced by the introduction of the weaning diet.
Sedighkia, Mahdi, Datta, Bithin, and Abdoli, Asghar (2022) Reducing the conflict of interest in the optimal operation of reservoirs by linking mesohabitat hydraulic modeling and metaheuristic optimization. Water Supply, 22 (2). pp. 2269-2286.
The present study proposes a novel framework to optimize the reservoir operation through linking mesohabitat hydraulic modeling and metaheuristic optimization to mitigate environmental impact downstream of the reservoir. Environmental impact function was developed by mesohabitat hydraulic simulation. Then, the developed function was utilized in the structure of the reservoir operation optimization. Different metaheuristic algorithms including practice swarm optimization, invasive weed optimization, differential evolution and biogeography-based algorithm were used to optimize reservoir operation. Root mean square error (RMSE) and reliability index were utilized to measure the performance of algorithms. Based on the results in the case study, the proposed method is robust for mitigating downstream environmental impacts and sustaining water supply by the reservoir. RMSE for mesohabitats is 8%, which indicates the robustness of proposed method to mitigate environmental impacts at downstream. It seems that providing environmental requirements might reduce the reliability of water supply considerably. Differential evolution algorithm is the best method to optimize reservoir operation in the case study.
Sedighkia, Mahdi, and Datta, Bithin (2022) A simulation-optimization system for evaluating flood management and environmental flow supply by reservoirs. Natural Hazards, 111. pp. 2855-2879.
The present study proposes and evaluates an applicable simulation-optimization framework for simulating and evaluating flood management and environmental flow supply by the reservoirs that was applied in the Australian tropical regions as the case study. 2D hydraulic modeling was utilized to simulate inundation area to develop inundation area function. Furthermore, minimum environmental flow regime and target of the environmental flow regime were defined based on the historical flow data in the optimization model of the reservoir operation. Different evolutionary algorithms were applied to optimize reservoir operation. Moreover, different indices were used to measure the performance of the optimization model. Based on the results in the case study, management of the flood damage and environmental flow is a serious challenge in the Australian tropical region that needs an optimal operation. The genetic algorithm was the best method to optimize reservoir operation based on the outputs of the decision-making system. The main application of the proposed framework for all case studies is simulation of the optimal operation in the past periods to get lessons for improvement of the operation in the future period. Moreover, coupling the proposed framework with the climate change models might be helpful to project the future challenges of the flood damage and environmental flow management.
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