In this paper, a simple and robust shock-capturing method is developed for the Flux Reconstruction (FR) framework by combining the Adaptive Mesh Refinement (AMR) technique with the ...positivity-preserving property. The adaptive technique avoids the use of redundant meshes in smooth regions, while the positivity-preserving property makes the solver capable of providing numerical solutions with physical meaning. The compatibility of these two significant features relies on a novel limiter designed for mesh refinements. It ensures the positivity of solutions on all newly created cells. Therefore, the proposed method is completely positivity-preserving and thus highly robust. It performs well in solving challenging problems on highly refined meshes and allows the transition of cells at different levels to be completed within a very short distance. The performance of the proposed method is examined in various numerical experiments. When solving Euler equations, the technique of Local Artificial Diffusivity (LAD) is additionally coupled to damp oscillations. More importantly, when solving Navier-Stokes equations, the proposed method requires no auxiliaries and can provide satisfying numerical solutions directly. The implementation of the method becomes rather simple.
Marker-assisted selection enables breeders to quickly select excellent root architectural variations, which play an essential role in plant productivity. Here, ten root-related and shoot biomass ...traits of a new F
recombinant inbred line (RIL) population were investigated under hydroponics and resulted in high heritabilities from 0.61 to 0.83. A high-density linkage map of the RIL population was constructed using a
50k Illumina single nucleotide polymorphism (SNP) array. A total of 86 quantitative trait loci (QTLs) explaining 4.16-14.1% of the phenotypic variances were detected and integrated into eight stable QTL clusters, which were repeatedly detected in different experiments. The codominant markers were developed to be tightly linked with three major QTL clusters,
,
, and
, which controlled both root-related and shoot biomass traits and had phenotypic contributions greater than 10%. Among these,
, renamed
, was further fine-mapped to a 129-kb interval with 19 annotated genes in the
reference genome. By integrating the results of real-time PCR and comparative sequencing, five genes with expression differences and/or amino acid differences were identified as important candidate genes for
. Our findings laid the foundation for revealing the molecular mechanism of root development and developed valuable markers for root genetic improvement in rapeseed.
In this work, we present the explicit strong stability-preserving (SSP) three-derivative Runge–Kutta (ThDRK) methods and propose the order accuracy conditions for ThDRK methods by Albrecht’s ...approach. Additionally, we develop the SSP theory based on the new Taylor series condition for the ThDRK methods and find its optimal SSP coefficient with the corresponding parameters. By comparing with two-derivative Runge–Kutta (TDRK) methods, Runge–Kutta (RK) methods and second derivative general linear methods (SGLMs), the theoretical and numerical results show that the ThDRK methods have the largest effective SSP coefficient for the order accuracy (
3
≤
p
≤
5
). The numerical experiments reveal that the ThDRK methods maintain the designed order of convergence on the linear advection and Euler equation, and indicate the ThDRK methods have effective computational cost.
Reef-building corals present various colony morphologies that may greatly influence their nutritional ecology. Fatty acids (FAs) and lipids are important components of corals and have been ...increasingly used to research the nutritional ecology of corals. In this study, we examined the symbiodiniaceae density, corallite area, total lipid content, and FAs composition of 14 species of corals with different colony morphologies. The results showed that the different colony morphology of coral was significantly correlated with the corallite area but not with the symbiodiniaceae density. Massive corals, with a large corallite area (7.16 ± 6.29 mm
2
), could ingest a high quantity of food, leading to high levels of total lipid content and unsaturated FAs particularly n-6 polyunsaturated FAs (PUFAs) and monounsaturated FAs. For branching corals, the total lipid content and saturated FAs (SFAs, 16:0 and 18:0) were significantly positively correlated with the Symbiodiniaceae density, indicating that branching corals are predominantly autotrophic. Moreover, compared with healthy corals, bleached corals consume larger amounts of stored energy (such as lipids and SFAs) to maintain their normal physiological functions. Although bleached corals may obtain PUFAs from heterotrophic assimilation or biosynthesize, the efficiency is too low to sufficiently replenish essential PUFAs in a short time. Overall, massive corals with more initial total lipid content and PUFAs exhibit an advantage under adverse environmental conditions.
Observation of coral spawning times is valuable to detect spawning patterns and identify the potential mechanisms behind coral reproduction. Although large amount of data on global coral spawning ...records have become available over the past decades, information on coral spawning in the northern South China Sea remains scarce. In this study, we investigated the spawning patterns of scleractinian corals in Luhuitou fringing reef, Hainan Island, China, from 2009 to 2021 in relation to lunar cycles (month and day). The spawning times of 22 coral species from five genera ( Acropora , Montipora , Platygyra , Dipsastraea , and Galaxea ) within three families (Acroporidae, Merulinidae, and Euphylliidae) were recorded, with spawning occurring from lunar February to May 2009–2021. Recorded spawning events started at a period of increasing seawater temperature. Acropora , the most documented genus, spawned between lunar February and April, but primarily in lunar March. Importantly, the spawning time of Acropora was delayed for one lunar month in 2016 most likely due to a rapid decrease in monthly mean seawater temperature in lunar February. Spawning lunar days before, on or after full moon of corals in the Luhuitou Reef, including those of the Acropora species, were highly variable between years even for the same species. No predictable pattern of spawning times can thus be detected. Nonetheless, our results fill up an information gap on coral spawning patterns in the northern South China Sea that may be useful for further understanding of the reproductive biology of scleractinian corals throughout the Indo–West Pacific.
Roots are complicated quantitative characteristics that play an essential role in absorbing water and nutrients. To uncover the genetic variations for root-related traits in rapeseed, twelve mature ...root traits of a
association panel were investigated in the field within three environments. All traits showed significant phenotypic variation among genotypes, with heritabilities ranging from 55.18% to 79.68%. Genome-wide association studies (GWAS) using 20,131 SNPs discovered 172 marker-trait associations, including 103 significant SNPs (-log10 (
) > 4.30) that explained 5.24-20.31% of the phenotypic variance. With the linkage disequilibrium r
> 0.2, these significant associations were binned into 40 quantitative trait loci (QTL) clusters. Among them, 14 important QTL clusters were discovered in two environments and/or with phenotypic contributions greater than 10%. By analyzing the genomic regions within 100 kb upstream and downstream of the peak SNPs within the 14 loci, 334 annotated genes were found. Among these, 32 genes were potentially associated with root development according to their expression analysis. Furthermore, the protein interaction network using the 334 annotated genes gave nine genes involved in a substantial number of interactions, including a key gene associated with root development,
This research provides the groundwork for deciphering
' genetic variations and improving its root system architecture.
•Yongxing Island is a natural laboratory for studying the effects of fishing on natural coral reef ecosystems.•Reducing fishing effort has improved the trophic level of fishing.•Appropriate ...vulnerability parameters should be selected when simulating fishing strategies.•Under different fishing strategies, there is a clear trend of biomass recovery for certain species as fishing effort decreases.
Fishing activities are known to have a predominantly negative impact on coral-reef ecosystem, but with the rise in conservation efforts, the reduction in fishing effort and the resilience of the ecosystem seem sufficient to mitigate the impacts and return to a better state of the ecosystem. Therefore, it is crucial to investigate how fishing practices affect the structure and function of coral-reef ecosystem and explore the role of different fishing strategies in promoting sustainable fishery resource development and effective conservation measures. Utilizing the Ecopath with Ecosim (EwE) modeling approach, we constructed pre- and post-fishing models (2015 and 2021) for the Yongxing Island reef area. Our findings indicated that a reduction in fishing effort significantly elevated the trophic level within the fishing zone. This phenomenon can primarily be attributed to the resurgence of Imreeffishc2 biomass, specifically within the Chaetodontidae, Mullidae, and Serranidae species. The positive impact of fishing were observed in only 14.63 % of fishery groups in 2015, a figure that is significantly lower than the 27.27 % recorded in 2021 following a reduction in fishing activities. Subsequent simulations of diverse fishing strategies revealed that the majority of populations recuperate with a decrease in fishing effort. However, a minority of groups exhibited a declining trend in biomass, which may be due to competition for food resulting in migration to more hospitable environments. In addition, we conducted simulations to ascertain the optimal vulnerability values across different groups. This study emphasizes the importance of reducing fishing effort as a means of restoring fishery resources and adopting different fishing strategies for different functional groups to achieve sustainable use of fishery resources.
In this article, an accurate and robust numerical method is developed for solving the compressible two-medium model. The method in arbitrary high-order case has the following significant features: ...Firstly, it uses the discrete equations in the differential framework of flux reconstruction (FR). This simple discretization automatically satisfies the Abgrall condition and avoids the production of oscillations around isolated interfaces. Secondly, it solves the diffuse interface five-equation system coupled with the equation of state (EOS) for stiffened gases. The method is applicable to more fluid mediums while not relying on special treatments of material interfaces. Thirdly, it provides physically meaningful solutions that are bound-preserving for volume fractions and positivity-preserving for density, energy, etc. The robustness of the method is greatly enhanced owing to the maintenance of the hyperbolic characteristic of the system in various problems. Finally, it may couple with the weighted essentially nonoscillatory (WENO) limiter that we design for the five-equation model. The smoothness and monotonicity of the final results can be further improved. The above features are well examined and reflected in the relevant numerical experiments.
•The IFWENO and THINC schemes are hybridized a priori using the shock detector.•The proposed hybrid scheme provides high resolution in both smooth and discontinuous regions.•A shock detector that can ...fully exploit the advantages of the THINC scheme is given.•A simplified positive-preserving limiter is employed to improve robustness.
The weighted essentially non-oscillatory (WENO) scheme is a famous shock-capturing scheme, but for high-precision numerical simulation, the classical WENO scheme is always considered to have excessive dissipation and insufficient resolution near discontinuities. Improving the accuracy order or reducing the dissipation of the WENO by optimizing the linear weights can effectively improve the resolution of this scheme in the smooth regions. However, under the same method, the improvement of shock-capturing abilities is generally limited and may lead to numerical oscillations. In order to simultaneously improve the resolution in discontinuous regions and ensure the performance of the smooth regions, this study uses the shock detector to combine the tangent of hyperbola for interface capturing (THINC) scheme, which is a better discontinuity-capturing scheme, with a given WENO discretization, such as the improved fast WENO (IFWENO) scheme that equips with high economy and does not loss accuracy at any critical point. The hybrid method in this study is an apriori algorithm, which is more efficient and universal than the method in (Takagi et al. J. Comput. Phys. 452(2022)110899). Additionally, the performance of the THINC scheme in different regions near the discontinuity is analyzed in detail through numerical experiments, and a shock detector that can fully exploit the advantages of the THINC scheme is provided. By using this shock detector, several one-dimensional and two-dimensional numerical cases are employed to verify that the hybrid scheme can greatly improve the performance in discontinuities without affecting the flow structure in the smooth regions, which proves the effectiveness of the proposed shock detector and the excellence of the hybrid IFWENO-THINC scheme.
PDF
