Bifurcation of a predator-prey system with generation delay and habitat complexity

Zhihui Ma,Haopeng Tang,Shufan Wang,Tingting Wang 대한수학회 2018 대한수학회지 Vol.55 No.1

In this paper, we study a delayed predator-prey system with Holling type IV functional response incorporating the effect of habitat complexity. The results show that there exist stability switches and Hopf bifurcation occurs while the delay crosses a set of critical values. The explicit formulas which determine the direction and stability of Hopf bifurcation are obtained by the normal form theory and the center manifold theorem.

BIFURCATION OF A PREDATOR-PREY SYSTEM WITH GENERATION DELAY AND HABITAT COMPLEXITY

Ma, Zhihui,Tang, Haopeng,Wang, Shufan,Wang, Tingting Korean Mathematical Society 2018 대한수학회지 Vol.55 No.1

In this paper, we study a delayed predator-prey system with Holling type IV functional response incorporating the effect of habitat complexity. The results show that there exist stability switches and Hopf bifurcation occurs while the delay crosses a set of critical values. The explicit formulas which determine the direction and stability of Hopf bifurcation are obtained by the normal form theory and the center manifold theorem.

Dissipative Fault Detection for Nonlinear Markov Jump Systems With Cyber Attacks and Hidden Mode Information Under Round-robin Protocol

Zhihui Wu,Siteng Ma,Dongyan Chen,Xue Zhao,Cai Chen 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.11

This paper addresses the problem of dissipative fault detection (FD) for nonlinear Markov jump systems (MJSs) with cyber attacks and hidden modal information, in which the round-robin (R-R) protocol is introduced to save network bandwidth. Two Bernoulli random variables are used to characterize the measurement affected by potential cyber attacks. The hidden Markov model (HMM) is employed to handle the phenomenon of hidden mode information. Subsequently, the sufficient conditions are derived based on the Lyapunov stability theory to ensure that the FD system is stochastically stable and stochastically strictly (Q1, Q2, Q3)-γ dissipative. The desired FD filter matrices are obtained by solving linear matrix inequalities (LMIs). Finally, a simulation is provided to verify the feasibility and effectiveness of the designed FD scheme.

Replacing alfalfa hay with amaranth hay: effects on production performance, rumen fermentation, nutrient digestibility and antioxidant ability in dairy cow

Ma Jian,Fan Xue,Sun Guoqing,Yin Fuquan,Zhou Guangxian,Zhao Zhihui,Gan Shangquan 아세아·태평양축산학회 2024 Animal Bioscience Vol.37 No.2

Objective: The aim of this research was to explore the effects of dietary substitution of alfalfa hay by amaranth hay on production performance, rumen fermentation, nutrient digestibility, serum biochemical parameters and antioxidant ability in dairy cows. Methods: A total of 45 healthy Holstein cows with same parity and similar milk yield and body weight were randomly divided into 3 groups: control diet without amaranth hay (CON) or 50% and 100% alfalfa hay replaced by an equal amount of amaranth hay (dry matter basis, AH1 and AH2, respectively). All the cows were fed regularly 3 times a day at 06:30, 14:30, and 22:30 and had free access to water. The experiment lasted for 60 d. Results: The dry matter intake of CON and AH1 groups was higher (p<0.05) than that of AH2 group. Compared with AH1 group, the milk yield of AH2 group was reduced (p<0.05). Moreover, dietary substitution of alfalfa hay by amaranth hay increased (p<0.05) milk fat, ammonia nitrogen and acetate concentrations. However, the crude protein digestibility of AH2 group was lower (p<0.05) than that of CON group, while an opposite tendency of serum urea nitrogen was found between two groups. The neutral detergent fiber digestibility of AH1 group was increased (p<0.05) when compared to AH2 group. Amaranth hay treatment increased (p<0.05) the serum concentration of glutathione peroxidase in dairy cows. Compared with CON group, the malonaldehyde activity of AH1 group was decreased (p<0.05). Conclusion: Dietary replacing alfalfa hay with amaranth hay (50% ratio) in dairy cows did not affect production performance but improved their antioxidant ability.

High Density Lipoprotein from Egg Yolk (EYHDL) Improves Dyslipidemia by Mediating Fatty Acids Metabolism in High Fat Diet-induced Obese Mice

Zhihui Yu,Changyi Mao,Xing Fu,Meihu Ma 한국축산식품학회 2019 한국축산식품학회지 Vol.39 No.2

We investigated the effect of high density lipoprotein from egg yolk (EYHDL) on serum, hepatic and fecal lipid and fatty acids (FAs) levels and on gene expression involved in FAs metabolism. Male KM mice were fed either normal diet (ND; n=20), high fat diet (HFD; n=20), or high fat diet containing EYHDL (EYHDL; 0.6 mg/g, every day by oral gavage, n=20) for 100 days. At the end of the experiment, the effects of treatments on biochemical parameters, FAs profiles and involved gene expression were analyzed. Our results revealed that EYHDL markedly suppressed the body weight gain, accumulation of abdominal fat tissues, serum concentrations of LDL-cholesterol (LDL-C) and triglycerides, hepatic triglycerides and cholesterol accumulation, while increased serum concentration of HDL-cholesterol (HDL-C). EYHDL intake also increased total cholesterol (TC) excretions compared with HFD group. Moreover, it alleviated the severity of fatty liver and improved glucose and insulin tolerance compared with HFD. More importantly, EYHDL partially normalized FAs profiles in serum, liver and fecaces and neutralized the HFD-induced upregulation of SREBP-1c, Acaca, Fasn, GPAT and Scd1. In conclusion, our findings indicate that EYHDL may have the potential to improve metabolic disturbances that occur in HFD mice and can be considered as an appropriate dietary recommendation for the treatment of metabolic syndrome (MetS).

Comparison of long-term effects of egg yolk consumption under normal and high fat diet on lipid metabolism and fatty acids profile in mice

Zhihui Yu,Ning Wang,Gan Hu,Meihu Ma 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.4

This study compared the long-term effects of EYconsumption under two diet conditions: normal (ND ?EY) and high fat diet (HFD ? EY), on lipid metabolism inmice. ND ? EY did not increase serum triglycerides, totalcholesterol hepatic triglyceride concentrations, adiposetissue accumulation and glucose impairment, not leading tofatty liver. HFD ? EY markedly decreased adipose tissueaccumulation, the triglyceride and total cholesterol, andimproved serum HDL-C and blood glucose impairmentcompared with HFD. PLS-DA analyzes showed bothND ? EY and HFD ? EY could decrease serum C18:1and MUFA. HFD ? EY could further decrease hepaticC18:2 and PUFA and increase C18:1 and MUFA excretion,which were associated with lower expression of Elovl6 andhigher expression of Scd1 in liver. These results suggestthat HFD ? EY significantly improved dyslipidemiacaused by HFD through modifying lipid metabolism, andND ? EY did not adversely affect the biomarkersassociated with dyslipidemia risk, but showed less obviousregulation of lipid metabolism than HFD ? EY.

A highly active Z-scheme NiGa2O4/anthraquinone/MoO3 photocatalyst via charge transfer for sunlight photocatalytic simultaneous conversions of nitrite and sulfite

Xue Ma,Siyi Li,Zhihui Qu,Meng Zhang,Jing Qiao,Xin Cui,Chunquan Wang,Jun Wang,Youtao Song 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.78 No.-

The separation efficiency of photogenerated electron-hole pairs (e –h+) is an important factor for ahighly photocatalytic activity of Z-scheme photocatalytic system. In order to suppress the recombining ofphotogenerated e and h+ and enhance the electron transfer rate, anthraquinone (AQ) as special electrontransfer channel is combined with NiGa2O4 and MoO3, forming a Z-scheme NiGa2O4/AQ/MoO3photocatalyst. Due to unique chemical and physical properties, AQ provides a novel electron transmissionway. Compared with traditional conductive channels (for example, noble metals and graphene), in thisway, the AQ may greatly enhance the electron transfer efficiency. In addition, the related morphology,optical properties and chemical composition were investigated by a sequence of characterizationmethods. The influences of photocatalyst species, irradiation time and used times in simultaneouslyconverting nitrite and sulfite under simulated sunlight were also studied. The results indicate that theprepared Z-scheme NiGa2O4/AQ/MoO3 photocatalyst exhibits a much high activity. The conversion ratesof nitrite and sulfite can reach 89.81% and 94.47%, respectively, under simulated sunlight irradiation forfour hours. The enhanced photocatalytic activity is attributed to the fact that AQ can rapidly transferelectron by inner charge transfer. This charge transfer way can provide a new idea to design subsequentphotocatalysts.

The Functional Properties of Preserved Eggs: From Anti-cancer and Anti-inflammatory Aspects

Changyi Mao,Zhihui Yu,Chengliang Li,Yongguo Jin,Meihu Ma 한국축산식품학회 2018 한국축산식품학회지 Vol.38 No.3

Preserved egg, a kind of alkaline-fermented food, is a traditional egg product in China. Here, we investigated the nutritional functions of preserved eggs by in vivo and in vitro experiments. The results of in vivo studies showed that the levels of triglycerides (TG), total cholesterol (TCHO) and low-density lipoprotein cholesterol/high density lipoprotein cholesterol (LDL-C/HDL-C) were significantly decreased (p<0.05) in the liver of rats treated with preserved eggs. Meanwhile, the levels of two important cancer markers, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), were also significantly decreased (p<0.05) in treated rats. In vitro studies were performed on Caco-2 cells, a human epithelial colorectal adenocarcinoma cell line. It demonstrated that the gastrointestinal (GI) digests of preserved eggs significantly accelerated (p<0.05) the apoptosis by upregulating caspase-3 in the Caco-2 cells. Besides, after treated with preserved eggs, the half maximal inhibitory concentration (IC50) of preserved eggs digests to Caco-2 cells was 5.75 mg/mL, indicating the significant inhibition of cell proliferation provided by preserved eggs (p<0.05). The results shown in this study demonstrated that preserved eggs may be a novel functional food involved with antilipemic, anti-inflammatory activity as well as the effect on accelarating the apoptosis of Caco-2 cells.

Effects of maternal dietary energy restriction on laying performance, embryonic development, and lipid metabolism in broilers

Sun, Hao,Chen, Zhihui,Ma, Chengzhan,Lian, Lina,Zhao, Zeyu,Niu, Shupeng,Xu, Liangmei,Sun, Jinhua Asian Australasian Association of Animal Productio 2022 Animal Bioscience Vol.35 No.5

Objective: The objective of this study was to investigate the effects of different degrees of maternal dietary energy restriction on lipid deposition in embryonic tissues during the medium laying period (37 to 39 weeks) in Arbor Acres (AA) broiler breeders. Methods: A single factor design was adopted, and 400 AA broiler breeders (20 weeks of age) with a similar weight were randomly allocated into four groups. The birds in the control group were fed a corn-soybean meal based diet, and those in trial groups were fed diets with 80%, 70%, and 50% energy levels of the basal diet. Incubated eggs from the medium laying period were collected. Samples of developing embryos at various stages were prepared for composition analysis. Results: The embryo weight in the 80% energy group was higher than those of the other groups on embryonic day (E) 13, but at 21 E, they were significantly decreased with decreasing energy intake of the broiler breeders (p<0.05). Additionally, the levels of crude fat in tissues in the restriction groups were significantly decreased (p<0.05). The long axis and area of adipocytes in breast muscle, thigh muscle and the liver were significantly decreased (p<0.05) at 21 E in the 80%, 70%, and 50% energy groups. Conclusion: The effects of the 80% maternal dietary energy restriction energy affects egg production performance, egg quality, and nutrient deposition in egg weights, which then directly impacts on the developmental process of embryos, especially on fat utilization and deposition.