Search

This paper proposes a variable time step, second-order time filter algorithm for the closed-loop geothermal system for the first time. The algorithm is easy to implement in programming, which greatly improves calculation efficiency, while improving the accuracy of convergence. Theoretically, we mainly analyze the stability and the convergence of the algorithm in the case of variable time steps. Finally, numerical experiments confirm the theoretical results and show that the algorithm can simulate geothermal system well. [ABSTRACT FROM AUTHOR]

Many researchers found that there is a close connection between biological rhythm and metabolism in mammals and humans. But, it is uncertain whether there is a central and peripheral clock system in fish or not, and it is also uncertain whether there is a relationship between them. This article used the model fish, marine medaka (Oryzias melastigma) as the experimental object, and built a complete test with 2 factors and 2 levels, the photoperiod factor with Light (L): Dark (D) = 16:8 and 12:12 and the factor of feeding time with 1 h after light and 1 h before dark, to verify the existence of the clock system and explore the relationship between biological rhythm and metabolism. The results showed that: In treatment 1# with L:D = 16:8 and 1 h after light, two clock genes of Bmal1 and Per1, among the tested 6 clock genes, had obvious rhythmic expression in the brain and in the liver, and 2 metabolic genes of Elovl5 and Lpl also had obvious rhythmic oscillations in the liver. In treatment 2# with L:D = 12:12 and 1 h after light, 3 clock genes (Bmal1, Per1 and Per2) had obvious rhythmic expression in the brain and in the liver, and 5 metabolic genes (Elovl5, Lpl, Fadsd2, Tryp, Pck) also presented rhythmic oscillations in the liver. Both treatments had the same photoperiod, the treatment with feeding at 1 h before dark still had several clock genes in the brain that were rhythmical, but neither clock gene nor metabolic gene in the liver exhibited obvious rhythmic oscillations. This study showed that there were biological rhythms in marine medaka, and there was a close relationship between the biological rhythm and the lipid metabolism. According to the set 2 factors, it is found that the photoperiod could mainly affect the central clock system, and the feeding time could mainly affect the rhythmic expression of the peripheral clock and metabolic genes. The conclusion will provide a scientific and efficient breeding strategy for marine medaka. [ABSTRACT FROM AUTHOR]

Objective: Diet acidification supplementation is known to influence intestinal morphology, gut microbiota, and on phosphorus (P) utilization of broilers. Alterations in intestinal barrier and microbiota have been associated with systemic inflammation and thus regulating bone turnover. Hence the effect of acidifier addition to drinking water on tibia mass and the linkages between intestinal integrity and bone were studied. Methods: One-d-old male broilers were randomly assigned to normal water (control) or continuous supply of acidified water (2% the blend of 2-hydroxy-4-methylthiobutyric acid, lactic, and phosphoric acid) group with 5 replicates of 10 chicks per replicate for 42 d. Results: Acidification of drinking water improved the ash percentage and calcium content of tibia at 42 d. Broilers receiving acidified water had increased serum P concentration compared to control birds. The acidified group showed improved intestinal barrier, evidenced by increased wall thickness, villus height, the villus height to crypt depth ratio, and upregulated mucin-2 expression in ileum. Broilers receiving drinking water containing mixed organic acids had a higher proportion of Firmicutes and the ratio of Firmicutes and Bacteroidetes, as well as a lower population of Proteobacteria. Meanwhile, the addition of acidifier to drinking water resulted in declined ileal and serum proinflammatory factors level and increased immunoglobulin concentrations in serum. Concerning bone remodeling, acidifier addition was linked to a decrease in serum C-terminal cross-linked telopeptide of type I collagen and tartrate-resistant acid phosphatase reflecting bone resorption, whereas it did not apparently change serum alkaline phosphatase activity that is a bone formation marker. Conclusion: Acidified drinking water increased tibia mineral deposition of broilers, which was probably linked with higher P utilization and decreased bone resorption through improved intestinal integrity and gut microbiota and through decreased systemic inflammation. [ABSTRACT FROM AUTHOR]