Let {X\-n,n≥1} be a stationary strongly mixing random sequence satisfying E X\-1=μ, E X\+2\-1<∞ and (Var S\-n)/n→σ\+2 as n→∞ . In this paper a class of estimators of Var S\-n is studied. Th...Let {X\-n,n≥1} be a stationary strongly mixing random sequence satisfying E X\-1=μ, E X\+2\-1<∞ and (Var S\-n)/n→σ\+2 as n→∞ . In this paper a class of estimators of Var S\-n is studied. The weak consistency and asymptotic normality as well as the central limit theorem are presented.展开更多
Background This study investigated the molecular mechanisms by which redox status regulates protoporphyrin IX(PpIX)biosynthesis and eggshell coloration in brown-shelled laying hens.This study consisted of two experime...Background This study investigated the molecular mechanisms by which redox status regulates protoporphyrin IX(PpIX)biosynthesis and eggshell coloration in brown-shelled laying hens.This study consisted of two experiments involving 48 and 32 healthy 60-week-old Hy-Line Brown hens,respectively.The hens exhibited either dark(L*=51.99±2.08)or light(L*=64.12±3.02)brown eggshell colors.In Exp.1,light brown-shelled hens were fed a basal diet(Lb group),while dark brown-shelled hens received either a basal diet(Db group)or a basal diet with 10 mg/kg ammonium metavanadate(Dbv group)for 20 d.In Exp.2,light brown-shelled hens received either a basal diet(Lbc group)or a basal diet supplemented with 200 mg/kg resveratrol(Lbr group)for 12 weeks.Results Compared to the Db group,eggshell L*values increased,and PpIX concentrations in both eggshell and uterus decreased in Dbv and Lb groups.These groups also showed oxidative stress,as indicated by reduced hepatic T-SOD and CAT activities.Uterine redox status changes were further confirmed by increased T-AOC level(Dbv)and reduced CAT gene expression(Lb).These redox disturbances led to reduced expression of ND4 and COX1 mt DNA,decreased ATP production and CS activity,along with upregulation of IR,PI3K,HK,and PK gene expression,reflecting altered mitochondrial energy metabolism.Notably,the SIRT1/PGC-1αsignaling cascade and its downstream target ALAS1 were significantly downregulated at both mRNA and protein levels in Dbv and Lb groups.Compared to the Lbc group,the Lbr group exhibited higher antioxidant capacity by increasing hepatic CAT activity and uterine T-SOD and GSH-Px activities,and reducing MDA levels.Moreover,the Lbr group restored mitochondrial function and PpIX biosynthesis by upregulating ND4 and COX1 mt DNA,CS and SDHA gene expression,and SIRT1/PGC-1α/ALAS1 signaling,while downregulating LDH activity and the expression of IR and PI3K,thereby alleviating eggshell color fading.Conclusion Oxidative stress induces eggshell depigmentation by impairing mitochondrial function and downregulating the SIRT1/PGC-1α/ALAS1 pathway,leading to reduced PpIX biosynthesis.Specifically,vanadium-induced or endogenous oxidative stress disrupts mitochondrial energy metabolism and suppresses key components of this pathway,while resveratrol alleviates oxidative damage and restores mitochondrial function and ALAS1-driven PpIX synthesis through reactivation of the SIRT1/PGC-1αaxis.展开更多
氧化应激导致褐壳鸡蛋壳颜色减退近期,中国农业科学院饲料研究所家禽营养与饲料创新团队研究发现,氧化应激会损伤线粒体功能,抑制原卟啉IX的生物合成,从而导致褐壳鸡蛋壳颜色减退。相关研究结果发表在《动物科学与生物技术杂志(Journal ...氧化应激导致褐壳鸡蛋壳颜色减退近期,中国农业科学院饲料研究所家禽营养与饲料创新团队研究发现,氧化应激会损伤线粒体功能,抑制原卟啉IX的生物合成,从而导致褐壳鸡蛋壳颜色减退。相关研究结果发表在《动物科学与生物技术杂志(Journal of Animal Science and Biotechnology)》上。蛋壳颜色不仅是消费者选购时的重要参考,也是反映蛋壳品质和母鸡健康的重要指标。团队研究发现,无论是外部应激还是内部衰老因素,都会引发氧化应激,造成肝脏和子宫的抗氧化能力下降、线粒体功能受损,能量生成减少。展开更多
In this paper, a notion of negative side ρ \|mixing ( ρ\+- \|mixing) which can be regarded as asymptotic negative association is defined, and some Rosenthal type inequalities for ρ\+- \|mixing random fields are est...In this paper, a notion of negative side ρ \|mixing ( ρ\+- \|mixing) which can be regarded as asymptotic negative association is defined, and some Rosenthal type inequalities for ρ\+- \|mixing random fields are established. The complete convergence and almost sure summability on the convergence rates with respect to the strong law of large numbers are also discussed for ρ\+-\| mixing random fields. The results obtained extend those for negatively associated sequences and ρ\+*\| mixing random fields.展开更多
Protoporphyrin Ⅸ(PPⅨ), a basic porphyrin system found in nature, all “porphyrin-type”tetrapyrroles with a biological function are biosynthetically derived thereof. PPⅨ is a metalloprosthetic group of numerous pro...Protoporphyrin Ⅸ(PPⅨ), a basic porphyrin system found in nature, all “porphyrin-type”tetrapyrroles with a biological function are biosynthetically derived thereof. PPⅨ is a metalloprosthetic group of numerous proteins involved in diverse metabolic and respiratory processes across all domains of life, and is thus considered essential for respiring organisms. Determining the biotic and abiotic factors that influence marine microbial growth and community structure is critical for understanding global biogeochemical cycles. Here,we present vertical profiles of intracellular PPⅨ and four derivative products(Chlorophylla/b and Pheophytin-a/b) from two coastal sediment cores, alongside ancillary geochemical and 16S rRNA microbial community data. Our findings indicated that PPⅨ is present in the natural sediment environment and displays a decreasing trend with depth, revealing a significant positive correlation with both organic matter and microbial abundance. Cooccurrence networks revealed that the environmental distribution of PPⅨ was positively correlated with the microbial porphyrin producer(high genetic completeness), but negatively correlated with auxotrophs(absence or low genetic completeness). It emphasized the critical role of PPⅨ as a biological molecule involved in key physiological processes. These results suggest that PPⅨ is a prominent component of the shared extracellular metabolite pool, especially in anoxic marine sediments where it exists at physiologically relevant concentrations for microbial metabolism. This study highlighted the significance of PPⅨ in microbial ecology and its potential impact on biogeochemical cycles in marine sedimentary environments.展开更多
文摘Let {X\-n,n≥1} be a stationary strongly mixing random sequence satisfying E X\-1=μ, E X\+2\-1<∞ and (Var S\-n)/n→σ\+2 as n→∞ . In this paper a class of estimators of Var S\-n is studied. The weak consistency and asymptotic normality as well as the central limit theorem are presented.
基金financially supported by the National Natural Science Foundation of China(32322078)the earmarked fund for the China Agriculture Research System(CARS-40)+1 种基金the China Postdoctoral Science Foundation(grant no.2024M763615)the Agricultural Science and Technology Innovation Program(ASTIP)of CAAS。
文摘Background This study investigated the molecular mechanisms by which redox status regulates protoporphyrin IX(PpIX)biosynthesis and eggshell coloration in brown-shelled laying hens.This study consisted of two experiments involving 48 and 32 healthy 60-week-old Hy-Line Brown hens,respectively.The hens exhibited either dark(L*=51.99±2.08)or light(L*=64.12±3.02)brown eggshell colors.In Exp.1,light brown-shelled hens were fed a basal diet(Lb group),while dark brown-shelled hens received either a basal diet(Db group)or a basal diet with 10 mg/kg ammonium metavanadate(Dbv group)for 20 d.In Exp.2,light brown-shelled hens received either a basal diet(Lbc group)or a basal diet supplemented with 200 mg/kg resveratrol(Lbr group)for 12 weeks.Results Compared to the Db group,eggshell L*values increased,and PpIX concentrations in both eggshell and uterus decreased in Dbv and Lb groups.These groups also showed oxidative stress,as indicated by reduced hepatic T-SOD and CAT activities.Uterine redox status changes were further confirmed by increased T-AOC level(Dbv)and reduced CAT gene expression(Lb).These redox disturbances led to reduced expression of ND4 and COX1 mt DNA,decreased ATP production and CS activity,along with upregulation of IR,PI3K,HK,and PK gene expression,reflecting altered mitochondrial energy metabolism.Notably,the SIRT1/PGC-1αsignaling cascade and its downstream target ALAS1 were significantly downregulated at both mRNA and protein levels in Dbv and Lb groups.Compared to the Lbc group,the Lbr group exhibited higher antioxidant capacity by increasing hepatic CAT activity and uterine T-SOD and GSH-Px activities,and reducing MDA levels.Moreover,the Lbr group restored mitochondrial function and PpIX biosynthesis by upregulating ND4 and COX1 mt DNA,CS and SDHA gene expression,and SIRT1/PGC-1α/ALAS1 signaling,while downregulating LDH activity and the expression of IR and PI3K,thereby alleviating eggshell color fading.Conclusion Oxidative stress induces eggshell depigmentation by impairing mitochondrial function and downregulating the SIRT1/PGC-1α/ALAS1 pathway,leading to reduced PpIX biosynthesis.Specifically,vanadium-induced or endogenous oxidative stress disrupts mitochondrial energy metabolism and suppresses key components of this pathway,while resveratrol alleviates oxidative damage and restores mitochondrial function and ALAS1-driven PpIX synthesis through reactivation of the SIRT1/PGC-1αaxis.
文摘氧化应激导致褐壳鸡蛋壳颜色减退近期,中国农业科学院饲料研究所家禽营养与饲料创新团队研究发现,氧化应激会损伤线粒体功能,抑制原卟啉IX的生物合成,从而导致褐壳鸡蛋壳颜色减退。相关研究结果发表在《动物科学与生物技术杂志(Journal of Animal Science and Biotechnology)》上。蛋壳颜色不仅是消费者选购时的重要参考,也是反映蛋壳品质和母鸡健康的重要指标。团队研究发现,无论是外部应激还是内部衰老因素,都会引发氧化应激,造成肝脏和子宫的抗氧化能力下降、线粒体功能受损,能量生成减少。
文摘In this paper, a notion of negative side ρ \|mixing ( ρ\+- \|mixing) which can be regarded as asymptotic negative association is defined, and some Rosenthal type inequalities for ρ\+- \|mixing random fields are established. The complete convergence and almost sure summability on the convergence rates with respect to the strong law of large numbers are also discussed for ρ\+-\| mixing random fields. The results obtained extend those for negatively associated sequences and ρ\+*\| mixing random fields.
基金supported by the Doctoral Research Initiation Fund Project of Hebei Normal University(No.L2025B19)PhD Fellowship of the State Key Laboratory of Marine Environmental Science at Xiamen University.
文摘Protoporphyrin Ⅸ(PPⅨ), a basic porphyrin system found in nature, all “porphyrin-type”tetrapyrroles with a biological function are biosynthetically derived thereof. PPⅨ is a metalloprosthetic group of numerous proteins involved in diverse metabolic and respiratory processes across all domains of life, and is thus considered essential for respiring organisms. Determining the biotic and abiotic factors that influence marine microbial growth and community structure is critical for understanding global biogeochemical cycles. Here,we present vertical profiles of intracellular PPⅨ and four derivative products(Chlorophylla/b and Pheophytin-a/b) from two coastal sediment cores, alongside ancillary geochemical and 16S rRNA microbial community data. Our findings indicated that PPⅨ is present in the natural sediment environment and displays a decreasing trend with depth, revealing a significant positive correlation with both organic matter and microbial abundance. Cooccurrence networks revealed that the environmental distribution of PPⅨ was positively correlated with the microbial porphyrin producer(high genetic completeness), but negatively correlated with auxotrophs(absence or low genetic completeness). It emphasized the critical role of PPⅨ as a biological molecule involved in key physiological processes. These results suggest that PPⅨ is a prominent component of the shared extracellular metabolite pool, especially in anoxic marine sediments where it exists at physiologically relevant concentrations for microbial metabolism. This study highlighted the significance of PPⅨ in microbial ecology and its potential impact on biogeochemical cycles in marine sedimentary environments.
