As an important metric for mesh quality evaluation, the isotropy property holds significant value for applications such as texture UV-mapping, physical simulation, and discrete geometric analysis. Classical isotropy remeshing methods adjust vertices and edge lengths, which exhibit certain limitations in terms of input data sensitivity, geometric consistency control, and convergence speed. In this paper, we propose an improved isotropy remeshing solution with inter-angle optimization during mesh editing to enhance shape control capability and accelerate convergence. The advantage of the solution lies in its ability to predict the impact of edge length adjustments on subsequent optimization by monitoring angle transformations. It avoids inefficient editing that may cause performance fluctuations, thereby improving efficiency. Experiments demonstrate that the proposed method effectively improves the overall efficiency of mesh optimization.
The carbon sink of cultivation shellfish in coastal wetlands is characterized as both highly ecological and economic value, thus making great contributions to achieving carbon neutrality. In this study, the main species of cultured shellfish (Ruditapes philippinarum, Meretrix meretrix, Sinonovacula constricta, Scapharca suberenata, and Grassostrea gigas) were selected as the research objects in the coastal wetland of the Yalu River Estuary to measure shellfish yields and carbon contents. Combined with the data from the cultured shellfish of fishery statistics of Donggang city, Dandong, Liaoning Province, China, the carbon sequestration capacity was calculated, and the carbon sink values of cultured shellfish also evaluated on the base of the diverse shellfish carbon sequestration ratios. The carbon sink conversion ratio of cultivation shellfish decreased in the following order: S. suberenata, R. philippinarum, G. gigas, S. constricta, and M. meretrix. The total carbon sequestration of cultured shellfish in the Yalu River Estuary Coastal Wetland from 2015 to 2019 was approximately 110,500 tC. The yield and the carbon sequestration quantity of R. philippinarum accounted for 76.60~83.30% of the total yield and 79.07~85.41% of the total carbon sequestration quantity. The value of the carbon sink was approximately 63,710,600 yuan. Among the species of cultured shellfish, R. philippinarum was the largest contributor to the carbon sink value. Based on Tapio’s decoupling model, R. philippinarum has the most ideal state of decoupling between carbon sink and economic growth of cultured shellfish, followed by M. meretrix and S. suberenata. Our results illustrate that the development of coastal wetland shellfish aquaculture has a positive contribution to reducing carbon emissions and increasing carbon sinks.
A group of loosely related, large‐bodied fishes collectively called carps have had a complex relationship with North Americans. Despite lessons learned about invasive Common Carp Cyprinus carpio in the early 1900s, Bighead Carp Hypophthalmichthys nobilis, Black Carp Mylopharyngodon piceus, Grass Carp Ctenopharyngodon idella, and Silver Carp H. molitrix were introduced to the United States more than 50 years ago and are expanding throughout the Mississippi River basin. Increased economic value in the North American seafood market could aid management. Complete eradication through harvest is unlikely, but controlling densities and containing dispersal may be possible. Improving perceptions of nutrition, palatability, and safety of wild‐caught carps should increase consumer demand. A branding and marketing effort launched in June 2022 renamed the foodstuff produced from the four species as the trademarked brand Copi. The “Choose Copi: Eat Well. Do Good.” campaign allows consumers to know that these fishes are an environmentally sound and responsible alternative to other seafood choices. The Copi brand has gained interest nationwide, with food processors and distributors engaged, although the contribution of Copi to harvest removal from rivers and resulting population dynamics is yet to be quantified. Developing a regional fishing industry for Copi, while also aiding fisheries and aquaculture for native species, remains an economic and logistical challenge within the vast river network.
ABSTRACTIn recirculating aquaculture systems (RAS), off‐flavours accumulated in fish muscle tissue can be problematic in terms of consumer acceptance and the reputation of farmed fish products. Off‐flavours often give fish earthy, muddy, or other undesirable flavours. Typically, off‐flavours are removed during a depuration period in which fish are fasted and held in clean water. Unfortunately, this causes additional costs and delayed sales, while fish lose weight and show a decrease in lipid content. First, we studied fish growth in a partial RAS (PRAS) where the conditions are very similar to those in depuration with a water exchange rate of 4000 L kg−1 feed, compared to RAS with a 650‐L water kg−1 feed. Rainbow trout (Oncorhynchus mykiss) was reared in both systems. Our aim was to combine the benefits of a higher water exchange rate: the lack of need for biofilters and a lower accumulation of off‐flavours while obtaining stable rearing conditions. Additionally, we studied the effects of moderate feeding and H2O2 addition during depuration. The fish grew faster in a PRAS than in a RAS when fed ad libitum. Thirteen off‐flavour compounds were found in the fish flesh and 11 in the circulating water. The H2O2 addition led to decreased levels of off‐flavours in the tank water and in fish muscle. The results showed no significant differences in off‐flavours between the fed and not‐fed systems, showing that moderate feeding did not prevent a good depuration result. However, the lipid content and the overall fish weight were higher in the fed systems, which suggests more effective depuration. Increased depuration efficiency can be an important tool when considering ways to improve the profitability of production.
We demonstrate the generic existence of Dirac cones in the full Bistritzer--MacDonald Hamiltonian for twisted bilayer graphene. Its complementary set, when Dirac cones are absent, is the set of magic angles. We show the stability of magic angles obtained in the chiral limit by demonstrating that the perfectly flat bands transform into quadratic band crossings when perturbing away from the chiral limit. Moreover, using the invariance of Euler number, we show that at magic angles there are more band crossings beyond these quadratic band crossings. This is the first result showing the existence of magic angles for the full Bistritzer--MacDonald Hamiltonian and solves Open Problem No.2 proposed in the recent survey arXiv:2310.20642.
Let $S_g$ be a closed orientable surface of genus $g \geq 2$, and let $\mathcal{T}_g$ be the Teichmüller space of $S_g$. Let $\mathcal{H}_g$ denotes the space of all hyperelliptic surfaces of genus $g$. For $g\geq 3$, we have proved that $\mathcal{T}_g$ can be parametrized by $6g-5$ angle parameters. We also prove that for $g\geq 2$, $\mathcal{H}_g$ can be parametrized by $4g-2$ angle parameters.
Md Moshiur Rahman, Nur Asma Ariffin, Ying Giat Seah
et al.
Understanding the reproductive biology of fishes is crucial to making accurate and scientifically sound recommendations for fisheries management. The presently reported study is the first to report the reproductive characteristics of the data-deficient and recently described yellowfin snapper, Lutjanus xanthopinnis Iwatsuki, Tanaka et Allen, 2015, collected from the eastern South China Sea, Malaysia. A total of 572 fish specimens were sampled monthly from March 2022 to April 2023 using a gillnet and a trawl net. Subsequently, these specimens were measured and weighed. Their total length (TL) ranged from 15.3 to 26.8 cm (19.25 ± 2.04 cm; mean ± SD). Their body weight (WB) ranged from 53.5 g to 279.7 g (114.5 ± 40.3 g; mean ± SD). For the reproductive biology study, the following parameters were determined: the sex ratio, gonadosomatic index (GSI), hepatosomatic index (HSI), spawning period, fecundity, condition factor (K), length at maturity, and the gonadal maturity stages. In the sex ratio, males (M) were significantly dominant over females (F) (M:F = 1:0.75) (χ2 = 11.18). Consequently, the monthly mean GSI of pooled sex revealed a consistent trend from January to August, indicating spawning seasons with peak periods in March and April. The batch fecundity of 67 mature females (16.0–25.2 cm TL; 64.5– 279.3 g W), was determined to range from 16 405 to 94 357 oocytes. The fecundity increased with gonad weight in contrast to weight and length. The length at first maturity of females and males was 14.53 and 20.56 cm, respectively. Females matured earlier than males. Macroscopic and histological examination of gonads revealed monthly variation in the ratio of gonad stages for males and females. This study offers crucial data on the reproductive biology of L. xanthopinnis, which will help with sustainable fishery management in this area and can be used as a reference for the management of similar fish populations in other regions of the world.
Yusuf Kamlasi, Sri Rejeki, Slamet Budi Prayitno
et al.
Seaweed cultivation area is habitat and development if the ecological conditions of the waters support the growth and survival of seaweed. Chlorophyll is one of the parameters that greatly determines primary productivity in the sea. The study aims to find out the patterns of chlorophyll-a spread and water quality in seaweed cultivation areas. The methods used in the investigation were the survey method for water sampling in the field and the spectrophotometry method for laboratory analysis. The results of the survey showed that the chlorophyll value in the seaweed cultivation area in October 2023 averaged 1.43 mg/m3, while in December 2023 the average chlorophyll-A level was 0.90 mg/m3. The chlorophyll-a content in the waters of the island of Semau in October 2023 ranged between 0.29 and 4.56 mg/m3, while in December 2023 it ranged between 0.09 and 2.82 mg/m3. Water quality parameters that affect chlorophyll distribution include nitrates, temperature, salinity, brightness, depth, dissolved oxygen, and pH.
Kawasan budidaya rumput laut sebagai tempat hidup dan berkembang jika kondisi ekologis perairan ikut mendukung pertumbuhan dan keberlangsungan rumput laut. Klorofil merupakan bagian dari parameter yang sangat menentukan produktivitas primer di laut. Penelitian ini bertujuan untuk mengetahui pola sebaran kloroil-a dan kualitas air di kawasan budidaya rumput laut. Metode yang digunakan dalam penelitan ini metode survey untuk pengambilan sampel air di lapangan dan metode Spektrofotometri untuk analisis laboratorium. Hasil peneletian menunjukkan bahwa nilai klorofil pada kawasan budidaya rumput laut pada bulan Oktober 2023 nilai rata-rata sebesar 1,43 mg/m3 sedangkan pada bulan Desember 2023 rata-rata klorofil-a adalah 0,90 mg/m3. Kandungan klorofil-a di perairan pulau Semau pada bulan Oktober 2023 berkirsar antara 0,29 – 4,56 mg/m3 sedangkan pada bulan Desember 2023 berkisar antara 0,09 – 2,82 mg/m3. Parameter kualitas air yang mempengaruhi distribusi klorofil-a seperti nitrat, suhu, salinitas, kecerahan, kedalaman, oksigen terlarut dan pH.
In this study, optimized multivitamin premix (OVP) was added to three kinds of different protein quality feeds (by decreasing dietary protein levels from 50% to 45% and replacing marine fish meal with terrestrial proteins) to investigate the effects of OVP on dietary protein quality-induced fatty liver in largemouth bass. Lysine (Lys) and methionine (Met) were supplied to ensure a consistent level of these two limiting amino acids. The results showed that decreased dietary protein quality did not affect the FBW and SGR of largemouth bass (P>0.05), but improved protein efficiency (P<0.05). However, decreased dietary protein quality impaired fish health and induced the occurrence of liver steatosis, manifested by fat accumulation, lipid metabolism disturbance, apoptosis, ER stress, and gut microbiome changes. Meanwhile, supplementation with OVP significantly reduced the FCR (P<0.05) and promoted dietary utilization in high- and low-protein-quality feed treatments. Supplementation with OVP reduced the contents of lipids, TC and TG, downregulated the mRNA expression of proinflammatory cytokines (nf-kb, tnf-α and il15), upregulated the mRNA expression of anti-inflammatory cytokines (il10 and tgf-β) in the liver, and reduced the relative abundance of intestinal flora related to liver steatosis (P<0.05). Furthermore, in the middle- and low-protein-quality feed treatments, supplementation with OVP alleviated ER stress and reduced ER stress-induced apoptosis through the hsp90/p38-mediated pathway. Finally, we found that supplementation with OVP could affect dhhc4 and dhhc5-mediated pathway to inhibit CD36 palmitoylation and facilitate CD36 mitochondrial localization, and alleviating the crosstalk between CD36 and the ER stress to prevent decreased dietary protein quality-induced hepatic steatosis.
A novel reconstruction method is introduced for the severely ill-posed inverse problem of limited-angle tomography. It is well known that, depending on the available measurement, angles specify a subset of the wavefront set of the unknown target, while some oriented singularities remain invisible in the data. Topological Interface recovery for Limited-angle Tomography, or TILT, is based on lifting the visible part of the wavefront set under a universal covering map. In the space provided, it is possible to connect the appropriate pieces of the lifted wavefront set correctly using dual-tree complex wavelets, a dedicated metric, and persistent homology. The result is not only a suggested invisible boundary but also a computational representation for all interfaces in the target.
Not everybody can be equipped with professional photography skills and sufficient shooting time, and there can be some tilts in the captured images occasionally. In this paper, we propose a new and practical task, named Rotation Correction, to automatically correct the tilt with high content fidelity in the condition that the rotated angle is unknown. This task can be easily integrated into image editing applications, allowing users to correct the rotated images without any manual operations. To this end, we leverage a neural network to predict the optical flows that can warp the tilted images to be perceptually horizontal. Nevertheless, the pixel-wise optical flow estimation from a single image is severely unstable, especially in large-angle tilted images. To enhance its robustness, we propose a simple but effective prediction strategy to form a robust elastic warp. Particularly, we first regress the mesh deformation that can be transformed into robust initial optical flows. Then we estimate residual optical flows to facilitate our network the flexibility of pixel-wise deformation, further correcting the details of the tilted images. To establish an evaluation benchmark and train the learning framework, a comprehensive rotation correction dataset is presented with a large diversity in scenes and rotated angles. Extensive experiments demonstrate that even in the absence of the angle prior, our algorithm can outperform other state-of-the-art solutions requiring this prior. The code and dataset are available at https://github.com/nie-lang/RotationCorrection.
Diatoms associated with the order Bacillariales, Rhopalodiales and Surirellales are well known to be present in marine and brackish waters. In this study, diatoms in the western Black Sea coasts of Turkey were investigated with ultrastructure details. Species belonging to the Bacillariales, Rhopalodiales and Surirellales were subject to light microscopy (LM) and scanning electron microscopy (SEM) analysis, and a total of twenty-four taxa were investigated. This study examines details on the morphology and biogeography of the taxa with remarks on their distribution in Turkey. The results revealed that four species were reported on the Turkish coasts for the first time. These species were Nitzschia liebethruthii, N. volvendirostrata, Epithemia guettingeri and Campylodiscus scalaris.