Motivated by a question of Erdös and inquiries by Beeson and Laczkovich, we explore the possible $N$ for which a triangle $T$ can tile into $N$ congruent copies of a triangle $R$. The \emph{reptile} cases (where $T$ is similar to $R$) and the \emph{commensurable-angles} cases (where all angles of $R$ are rational multiples of $π$) are well-understood. We tackle the most interesting remaining case, which is when $R$ contains an angle of $2π/3$ and when $T$ is one of $6$ ``sporadic'' specific triangles, of which only $2$ were known to have constructions. For each of these, we create a family of constructions and conjecture that they are the only possible $N$ that occur for these triangles.
In recent years, the death rate of Procambarus clarkii increased sharply due to pathogenic bacterial infections, leading to huge economic losses. To determine the immune response of the intestinal tissues of P. clarkii to bacterial infections, we compared the immune indexes, histopathological damage, and transcriptome data of the control and Aeromonas hydrophila-infected P. clarkii. With the injection of A. hydrophila, it was found that intestinal mucosal folds increased, intestinal villi showed obvious vacuolation, and the tissue structure changed significantly. The results of non-specific immunoenzyme activity showed that the Total protein (TP) content was significantly lower than that of the control group at 24 h, and the Acid phosphatase (ACP) and Alkaline phosphatase (AKP) activities in the treatment group showed a significant increasing trend (p < 0.05). In terms of the transcriptome, an average of 22,927,523 clean reads and 27,866 genes were found in the control and treatment groups through gene assembly and annotation. Among these genes, 567 were identified as differentially expressed genes (DEGs), of which 501 were up-regulated and 66 were down-regulated. Quantitative-polymerase chain reaction (qPCR) analysis of six randomly selected genes was used to verify the RNA-sequencing results. The Gene Ontology enrichment analysis revealed that the DEGs were primarily involved in cell processes, metabolic processes, and biological regulation, while the Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that these DEGs were involved in tyrosine metabolism, glycosphingolipid biosynthesis—ganglionic series, and nitrogen metabolism. We studied the tyrosine metabolic pathway and found that it contributes to the immune defense mechanism of P. clarkii. The results of our study provide important insights into the intestinal immune response of P. clarkii to A. hydrophila infection.
Alaa A. El-Dahhar, Rashwan S. Rashwan, Samy Y. EL-Zaeem
et al.
Adapted European seabass (Dicentrarchus labrax L.) larvae at 25 days post-hatching (dph) with a primary weight and length of 23 mg and 9.92 mm, start the weaning up to 46 dph using the weaning micro-diet (54% crude protein from fish meal, powder milk, and poultry egg) concurrently with Artemia enriched with fortification emulsions (0.6 g/L) of DHA selco® as a control group (DHAS) or Fish oil + 20% Vitamin C (FOVC), or Fish oil + 20% Vitamin E (FOVE), or Fish oil + 10% Vit. C +10% Vit. E (FOCE), or Fish oil only (FO). At 46 dph, groups of larvae fed enriched Artemia with DHAS and FOVE exhibited the highest final body weight, weight gain, average daily gain, specific growth rate, feed intake, protein efficiency ratio, and survival% as well as the lowest feed conversion ratio. Meanwhile, larvae in FOVC displayed the lowest final body weight, total length, weight gain, average daily gain, specific growth rate, feed intake, protein efficiency ratio, and survival% as well as the highest feed conversion ratio. Gastrointestinal histological assessment exhibited no pathological alteration as well as an improvement in the structure with DHAS, FOVE, FOVC, and FOCE co-additives compared to FO. Glutathione peroxidase enzyme (GPx) recorded the highest rates (P < 0.05) in groups fed Artemia supplemented with DHAS and FOVE followed by FOCE and FOVC. While the lowest record for GPx activity was noted in the FO group. In conclusion, Using augmented Artemia nauplii with fish oil + vitamin E in single or in companion with vitamin C as cheap antioxidants support D. labrax larval growth, survival, and antioxidant efficacy during the critical weaning period.
Geographically separated populations of Culter alburnus in China exhibit marked physiological and behavioral characteristics, particularly between populations inhabiting the northern and southern part of Huai River (HR), indicating their adaptation to local environments. In this study, the morphological characteristics of C. alburnus were measured, and restriction site associated DNA (RAD) sequencing was used for C. alburnus to investigate the genomic features of the Xingkai Lake (XKL) population from the northern part and HR, Yangtze River (YR), and Dianshan Lake (DSL) populations from the southern part of China. Analyses results revealed significant morphological differences and population genetic structure among these populations, with pronounced genetic differentiation between the northern and the southern part. Notably, the northern (XKL) population exhibited significantly lower genetic diversity than the other three southern populations. Furthermore, genes involved in synaptic vesicle transmission regulation, androgen receptor signaling, and behavior regulation pathways, including oligophrenin 1, ch25h13, androgen receptor, and Rho kinase genes, showed selection signals with high genetic differentiation indices (Fst), significant nucleotide diversity (Pi) differences, and significantly differential expression values in the northern (XKL) population compared with southern populations. These findings indicate that these genes may influence the different adaptive reflex behavioral responses of northern and southern C. alburnus populations. This study highlights the genetic structure and adaptations of C. alburnus, providing important resources for its management and aquaculture.
Rice–turtle co-culture is an ecological method involving a low exogenous input of chemicals and excessive feeding might increase the cost and reduce the mutual beneficial effect. To determine the optimal feeding level for co-cultured P. sinensis and for its adaptation, the turtles (878.0±10.3 g) were fed at feeding levels of 0.7 %, 1.4 % and 2.1 % for 90 days. The observation of feeding behavior showed that a low feeding level prompted the turtles to move into field paddies and prolonged their stay. The specific growth rate increased with increasing feeding level, but did not further increase when it exceeded 1.4 %, and the feed conversion ratio increased with increasing feeding level from 0.7 % to 2.1 %. The activities of digestive enzymes were higher in the group with a low feeding level. The plasma triglyceride and total cholesterol levels increased with increasing feeding level, while the creatinine level was significantly lower at a high feeding level of 2.1 %. The trend analysis of gene expression showed that the expression of most of differentially expressed genes (DEGs) in the brain decreased with increasing feeding levels from 0.7 % to 1.4 % and did not further decrease at a feeding level of 2.1 %, while in the gut, most of the genes were significantly downregulated or upregulated at a feeding level of 1.4 %. In the brain, the pathways associated with the DEGs were involved in the relaxin signaling pathway, melanogenesis and the age–rage signaling pathway in diabetic complications. In the gut, the DEGs were most associated with pancreatic secretion, protein digestion and absorption. The related genes expression was consistent with feeding behavior, growth and physiological metabolism. These findings suggest that co-cultured turtles can adapt to different feeding levels, that the optimal feeding level for co-cultured turtles is 1.4 %, and that additional feeding reduced the economic and ecological benefits of co-culture.
Felipe Ceolin, Aline Felix Schneider Bedin, Clóvis Eliseu Gewehr
ABSTRACT The performance and morphometry of intestinal villi were evaluated in piglets fed liquid diets with different water levels compared to dry diets during the first week after weaning. The experiments were using 48 piglets around 7 kg, weaned at 25 days of age, and housed in 24 bays for seven days. A completely randomized design was adopted with six treatments: dry feed (control) provided in the feeder and water provided in the drinker; control diet moistened with water in a 1:1 ratio (feed/water) and access to the drinker (1:1+water); control diet moistened with water in a 1:2 ratio (feed/water) and access to the drinker (1:2+water); control diet moistened with water in a 1:3 ratio (feed/water) and access to the drinker (1:3+water); control diet moistened with water in a ratio of 1:2 (feed/water) without access to the drinker (diet 1:2/no water); control diet moistened with water in a ratio of 1:3 (feed/water) without access to the drinker (diet 1:3/no water). In the 1:2+water and 1:3+water diets, there was an improvement in piglet performance compared to the dry diet. The 1:2+water diet improved the duodenal villus/crypt ratio and the 1:2+water and 1:3+water diets improved the jejunal villus/crypt ratio compared to the dry diet.
In this paper, we introduce a method for calculating the deflection angle in the weak-field approximation, applicable to both null and timelike rays. By combining the trajectory equation $\mathcal{Z}(u)=(du/dφ)^2$ and the `straight line' $u(\varphi)={\sin\varphi}/b$, we introduce a new function $Φ(\varphi)$. The deflection angle can then be expressed as $δ=Φ(0)+Φ(π)-π$, which directly depends on the impact parameter rather than the closest approach distance. This method offers a convenient and straightforward approach to calculations, avoiding the complexities of integration or iterative procedures. As an illustrative application, we compute the deflection angle for charged particle in the Kerr-Newman spacetime.
Given a finite subset of a sphere or projective space, known as a design, we can compute the strength and angle set of that design. When the strength and angle set meet certain bounds, the design is called tight. Hoggar sought to prove that, aside from certain known cases, the angle sets of tight projective designs must be rational. Lyubich found a counter-example and provided a repair for Hoggar's proof but excluded the exceptional octonion projective cases. This note extends Lyubich's repair of Hoggar's proof to the remaining projective cases and extends the proof to all spherical cases. It does so by using Jordan algebra primitive idempotents to treat all of the cases simultaneously. We thereby confirm that tight spherical and projective designs have rational angle sets except in specific cases.
Alexis Imbert, Julien Cucherousset, Nathalie Parthuisot
et al.
AbstractRecreational fishing, through groundbaiting, provides a potentially important trophic subsidy to freshwater ecosystems that could promote eutrophication. To date, our understanding of the role of bait properties on their fate when they are not consumed remains limited. The present study aimed to determine if the C:N:P composition of some of the most commonly used angling baits modulated microbial decomposition. The C:N:P composition of 28 models of four commercially available angling baits was assessed and a microcosm experiment was used to quantify microbial decomposition. Elemental composition strongly varied among angling baits, with N content varying by a factor of three and P content varying by a factor of five. Microbial decomposition of angling baits was highly variable and faster for more industrialised baits. Microbial decomposition was five times faster for angling baits rather than natural subsidies (leaves) and was not significantly correlated with high N or P content. Compared to natural subsidies, angling baits were a favourable substrate for bacterial growth. Angling baits represent a source of highly available nutrients and the most‐enriched angling baits might affect ecological processes and water quality in ecosystems with high angling pressure, especially when their use is not regulated.
Abstract As demand for ingredients for fish feed has increased, fish meal and fish oil converted from fisheries by‐products have gained importance as ingredients to replace forage fish. It has been demonstrated that high quality fish oil and fish meal made from urban fisheries biomass, which is fisheries by‐products collected downstream in the seafood supply chain, could be produced. However, a problem with this is that traceability is not ensured due to the wide variety of fish used. Here, a DNA metabarcoding method for monitoring biodiversity was applied to fish meal from the fisheries biomass produced in Japan. This method was shown to be able to detect fish species present at more than 0.001% by weight, and quantitatively detect more than 0.01% by weight; we successfully detected 81–122 species in amplicon sequence variants obtained from fish meals collected throughout a 1‐year period. Bray–Curtis similarity classified the samples into two clusters: one in spring to autumn and one in winter, indicating a considerable influence of skipjack tuna ( Katsuwonus pelamis ) on the fish constituting the fisheries biomass. Among the detected fish species present at more than 0.01% in fish meal, southern bluefin tuna ( Thunnus maccoyii ) and Japanese eel ( Anguilla japonica ) might be of concern for their stock and illegal, unreported, and unregulated fishery risks. However, from the food recycling perspective, fish oil and fish meal from the fisheries biomass should be utilized, as long as these fish comprised in the biomass are not caught for feed purposes.
Rabia Alghazeer, Hesham El Fatah, Salah Azwai
et al.
Macroalgae are a valuable source of highly bioactive primary and secondary metabolites that may have useful bioapplications. To investigate the nutritional and nonnutritional contents of underexploited edible seaweeds, proximate composition, including protein, fat, ash, vitamins A, C, and E, and niacin, as well as important phytochemicals, including polyphenols, tannins, flavonoids, alkaloids, sterols, saponins, and coumarins, were screened from algal species using spectrophotometric methods. Ash content ranged from 3.15–25.23% for green seaweeds, 5–29.78% for brown algae, and 7–31.15% for red algae. Crude protein content ranged between 5 and 9.8% in Chlorophyta, 5 and 7.4% in Rhodophyta, and between 4.6 and 6.2% in Phaeophyceae. Crude carbohydrate contents ranged from 20 to 42% for the collected seaweeds, where green algae had the highest content (22.5–42%), followed by brown algae (21–29.5%) and red algae (20–29%). Lipid content was found to be low in all the studied taxa at approximately 1–6%, except for Caulerpa prolifera (Chlorophyta), which had a noticeable higher lipid content at 12.41%. These results indicated that Phaeophyceae were enriched with a high phytochemical content, followed by that of Chlorophyta and Rhodophyta. The studied algal species contained a high amount of carbohydrate and protein, indicating that they could be considered as a healthy food source.
Min-Soo Joo, Kwang-Min Choi, Gyoungsik Kang
et al.
Interferon regulatory factor (IRF) 3 and IRF7 are important innate immune-related genes that induce type I interferon (IFN). In this study, PmIRF3 and PmIRF7 were identified from red sea bream (Pagrus major) infected by red sea bream iridovirus (RSIV), and expression and functional analyses were performed. PmIRF3 and PmIRF7 consisted of 465 and 436 amino acids, respectively, and contained a well-conserved IRF domain, IRF3 domain, and serine-rich domain (SRD). PmIRF3 and PmIRF7 are ubiquitously expressed in the liver and gills in normal fish, and with a high expression being recorded in kidney and spleen during RSIV infection. In P. major fin cells (PMF cells), pAcGFP-PmIRF3 and pAcGFP-PmIRF7 were localized to the cytoplasm, and overexpression of PmIRF3 and PmIRF7 using the pcDNA3.1 vector induced type I IFN. In addition, in the experiment in vitro, PMF cells overexpressed with PmIRF3 or PmIRF7 exhibited antiviral activity against RSIV and significantly reduced viral genome copies and virus titer. Therefore, PmIRF3 and PmIRF7 may have antiviral activity through the induction of type I IFN against RSIV infection of red sea bream.
The Naive Angle Method, used by Geometry Expressions for solving problems which involve only angle constraints, represents a geometrical configuration as a sparse linear system. Linear systems with the same underlying matrix structure underpin a number of different geometrical theorems. We use a graph theoretical approach to define a generalization of the matrix structure.