Drosophila melanogaster mutants with deficient kynurenine (KYN) formation from tryptophan (TRP) have longer life span than wild type flies. Administration of alpha-methyl-TRP and 5-methyl-TRY, the inhibitors of TRP-KY...Drosophila melanogaster mutants with deficient kynurenine (KYN) formation from tryptophan (TRP) have longer life span than wild type flies. Administration of alpha-methyl-TRP and 5-methyl-TRY, the inhibitors of TRP-KYN metabolism, prolonged life span in wild-type flies. Both inhibitors are not available for human use. Berberine, an isoquinoline alkaloid isolated from berberis aristata is known as the herb widely used in traditional Chinese and Indian medicine. Berberin is a strong inhibitor of the enzyme catalyzing TRP conversion into KYN. Considering this particular feature we investigated the effect of berberine on life-and health-span in wild-type Drosophila melanogaster. The results of our study showed that Berberine extended mean, median and maximum life span of female flies. Berberine did not affect the number of pupae of filial generation and decreased their lethality. Berberine increased locomotor activity (vertical climbing). The results of the study suggest that berberine prolongs life- and improves health-span of Drosophila melanogaster. Berberine might be a candidate drug for prevention and treatment of aging and aging-associated medical and psychiatric disorders.展开更多
The ef fects of salinity on the copepod, A cartia tonsa in terms of daily egg production rate(EPR), hatching success, fecal pellet production rate(FPR), naupliar development time and survival, sex ratio, and total lif...The ef fects of salinity on the copepod, A cartia tonsa in terms of daily egg production rate(EPR), hatching success, fecal pellet production rate(FPR), naupliar development time and survival, sex ratio, and total life span were determined in laboratory conditions through three experiments. In experiment 1, EPR, hatching success, and FPR of individual females were monitored at salinities of 13, 20, 35 and 45 during short-periods(seven consecutive days). Results show EPR was aff ected by salinity with the highest outputs recorded at 20 and 35, respectively, which were considerably higher than those at 13 and 45. Mean FPR was also higher in 35 and 20. In experiment 2, the same parameters were evaluated over total life span of females(long-term study). The best EPR and FPR were observed in 35, which was statistically higher than at 13 and 20. In experiment 3, survival rates of early nauplii until adult stage were lowest at a salinity of 13. The development time increased with increasing of salinity. Female percentage clearly decreased with increasing salinity. Higher female percentages(56.7% and 52.2%, respectively) were signifi cantly observed at two salinities of 13 and 20 compared to that at 35(25%). Total longevity of females was not af fected by salinity increment. Based on our results, for mass culture we recommend that a salinity of 35 be adopted due to higher reproductive performances, better feeding, and faster development of A. tonsa.展开更多
This paper deals with the Cauchy problem for a doubly singular parabolic equation with a weighted source ut=div｜u｜p-2um）＋｜x｜α uq ,（x,t）∈RN×（0,t）,where N ≥ 1, 1 〈 p 〈 2, m 〉 max（0,3 -p/N} satisfyi...This paper deals with the Cauchy problem for a doubly singular parabolic equation with a weighted source ut=div｜u｜p-2um）＋｜x｜α uq ,（x,t）∈RN×（0,t）,where N ≥ 1, 1 〈 p 〈 2, m 〉 max（0,3 -p/N} satisfying 2 〈 p＋m 〈 3, q 〉 1, and（α 〉 N（3 - p - m） - p. We give the secondary critical exponent on the decay asymptotic behavior of an initial value at infinity for the existence and non-existence of global solutions of the Cauchy problem. Moreover, the life span of solutions is also studied.展开更多
Implications of the differences in leaf life span are still subject to debate in the field of ecophysiology.Since leaf traits associated with these differences may be decisive for determining the distribution of tree ...Implications of the differences in leaf life span are still subject to debate in the field of ecophysiology.Since leaf traits associated with these differences may be decisive for determining the distribution of tree species,this topic is particularly relevant in the context of climate change.This study analyzes the effects of the differences in leaf life span on premature losses of leaf area owing to insect herbivory and to abiotic stress.Loss of leaf area may be an important determinant of total leaf carbon assimilation.Seven Mediterranean tree species,distributed on four sites with different climates were studied.The species exhibited strong differences in leaf life span and in leaf traits,especially leaf mass per unit area.Premature leaf area losses were estimated in response to insect herbivory and summer drought over two years.The results revealed that,despite having older leaf cohorts with more damage,species with longer leaf duration had lower area lost to herbivores and less damage due to accelerated senescence during the summer drought.With respect to the predicted increase in water stress,deciduous species are at a disadvantage due to their high premature loss of leaf area and thus loss of photosynthetic capacity.展开更多
In this paper the authors consider Cauchy problem of first order quasilinear hyperbolic and prove that existence of its periodic solutions and estimates of life span of solutions. This results reveals the relationship...In this paper the authors consider Cauchy problem of first order quasilinear hyperbolic and prove that existence of its periodic solutions and estimates of life span of solutions. This results reveals the relationship of dissipation and smoothness of periodic solutions.展开更多
The paper concerns Cauchy,problem for one-dimensional hydromagnetic dynamics with dissipative terms. When the dissipation coefficient is equal to zero it is shown that the smooth solutions develop shocks in the finite...The paper concerns Cauchy,problem for one-dimensional hydromagnetic dynamics with dissipative terms. When the dissipation coefficient is equal to zero it is shown that the smooth solutions develop shocks in the finite time if the initial amounts of entropy and magnetic field are smaller than those of sound waves; when it is larger than zero, and the initial amounts of entropyI this dissipation coefficient and the magnetic field in each period are smaller than those of sound Waves, then the smooth solutions blow up in the finite time. Moreover, the life-span of the smooth solution is given.展开更多
In this article, we investigate the lower bound of life-span of classical solutions of the hyperbolic geometry flow equations in several space dimensions with ＂small＂ initial data. We first present some estimates on...In this article, we investigate the lower bound of life-span of classical solutions of the hyperbolic geometry flow equations in several space dimensions with ＂small＂ initial data. We first present some estimates on solutions of linear wave equations in several space variables. Then, we derive a lower bound of the life-span of the classical solutions to the equations with ＂small＂ initial data.展开更多
Dietary γ-amino butyric acid (GABA) has been suggested to decrease systolic blood pressure. This study aimed to ex-amine the effects of dietary GABA on the life span of stroke-prone spontaneously hypertensive rats (S...Dietary γ-amino butyric acid (GABA) has been suggested to decrease systolic blood pressure. This study aimed to ex-amine the effects of dietary GABA on the life span of stroke-prone spontaneously hypertensive rats (SHRSPs). In this study, life span was determined for SHRSPs provided 1% NaCl solution or 0.01% GABA in 1% NaCl solution as drinking water. The life span of the GABA-fed group (76.3 ± 1.65 days) was significantly shorter than that of the control group (81.6 ± 0.88 days). The results of this study may not be applicable to humans. Future studies will be necessary to elucidate the mechanism underlying this phenomenon.展开更多
Considering the insulators ageing in a mixture of PVC and dye, set following operating conditions and time to ensure proper operation and perfect safety of industrial installations using insulated conductors. The resu...Considering the insulators ageing in a mixture of PVC and dye, set following operating conditions and time to ensure proper operation and perfect safety of industrial installations using insulated conductors. The results showed that the insulation carried out by the L.C main office was a good quality (on thermal aspect), because the resistance of the insulation is so high (i.e. 3940 Mega Ohms under normal conditions). The results showed a lifespan of 50 years at a temperature of 40°C (close to ambient temperature), plus minus 33 years at a temperature of 70°C;plus minus 22 years at a temperature of 100°C and 12 years at a temperature of 160°C. Furthermore, information on chemical attack, the results showed that PVC cables have poor resistance to sulfuric acid attack (having a pH of 1.5 and a density of 1.84 g/cm<sup>3</sup>). LC/Gecamines is able to produce locally a good quality of electrical cables.展开更多
Owing to the complex environmental conditions, suspension could induce complicated forces on submarine pipelines and even cause vortex-induced vibration, resulting in fatigue damage of pipelines. Through aiming at the...Owing to the complex environmental conditions, suspension could induce complicated forces on submarine pipelines and even cause vortex-induced vibration, resulting in fatigue damage of pipelines. Through aiming at the 28-inch submarine pipeline in the East China Sea, the pipeline was segmented according to the similarity, considering the factors of pipe assembly, typhoon, current, wave and seabed topography. The effects of span length on natural frequency in each section of submarine pipeline were analyzed by finite element model. The maximum safe span length allowed by each pipeline section was verified by fatigue cumulative damage theory, and the fatigue life of each pipeline section were predicted. The results showed that each order natural frequency of the pipeline decreased with the increase of span length. The calculated results of empirical formulas were much smaller than those of the FEM analysis. The increase of the gap between the suspended pipeline and the seabed was beneficial to enhance the fatigue life of the suspended pipeline.展开更多
文摘Drosophila melanogaster mutants with deficient kynurenine (KYN) formation from tryptophan (TRP) have longer life span than wild type flies. Administration of alpha-methyl-TRP and 5-methyl-TRY, the inhibitors of TRP-KYN metabolism, prolonged life span in wild-type flies. Both inhibitors are not available for human use. Berberine, an isoquinoline alkaloid isolated from berberis aristata is known as the herb widely used in traditional Chinese and Indian medicine. Berberin is a strong inhibitor of the enzyme catalyzing TRP conversion into KYN. Considering this particular feature we investigated the effect of berberine on life-and health-span in wild-type Drosophila melanogaster. The results of our study showed that Berberine extended mean, median and maximum life span of female flies. Berberine did not affect the number of pupae of filial generation and decreased their lethality. Berberine increased locomotor activity (vertical climbing). The results of the study suggest that berberine prolongs life- and improves health-span of Drosophila melanogaster. Berberine might be a candidate drug for prevention and treatment of aging and aging-associated medical and psychiatric disorders.
文摘The ef fects of salinity on the copepod, A cartia tonsa in terms of daily egg production rate(EPR), hatching success, fecal pellet production rate(FPR), naupliar development time and survival, sex ratio, and total life span were determined in laboratory conditions through three experiments. In experiment 1, EPR, hatching success, and FPR of individual females were monitored at salinities of 13, 20, 35 and 45 during short-periods(seven consecutive days). Results show EPR was aff ected by salinity with the highest outputs recorded at 20 and 35, respectively, which were considerably higher than those at 13 and 45. Mean FPR was also higher in 35 and 20. In experiment 2, the same parameters were evaluated over total life span of females(long-term study). The best EPR and FPR were observed in 35, which was statistically higher than at 13 and 20. In experiment 3, survival rates of early nauplii until adult stage were lowest at a salinity of 13. The development time increased with increasing of salinity. Female percentage clearly decreased with increasing salinity. Higher female percentages(56.7% and 52.2%, respectively) were signifi cantly observed at two salinities of 13 and 20 compared to that at 35(25%). Total longevity of females was not af fected by salinity increment. Based on our results, for mass culture we recommend that a salinity of 35 be adopted due to higher reproductive performances, better feeding, and faster development of A. tonsa.
基金partially supported by the Doctor Start-up Funding and Natural Science Foundation of Chongqing University of Posts and Telecommunications(A2014-25 and A2014-106)partially supported by Scientific and Technological Research Program of Chongqing Municipal Education Commission(KJ1500403)+3 种基金the Basic and Advanced Research Project of CQCSTC(cstc2015jcyj A00008)partially supported by NSFC(11371384),partially supported by NSFC(11426047)the Basic and Advanced Research Project of CQCSTC(cstc2014jcyj A00040)the Research Fund of Chongqing Technology and Business University(2014-56-11)
文摘This paper deals with the Cauchy problem for a doubly singular parabolic equation with a weighted source ut=div｜u｜p-2um）＋｜x｜α uq ,（x,t）∈RN×（0,t）,where N ≥ 1, 1 〈 p 〈 2, m 〉 max（0,3 -p/N} satisfying 2 〈 p＋m 〈 3, q 〉 1, and（α 〉 N（3 - p - m） - p. We give the secondary critical exponent on the decay asymptotic behavior of an initial value at infinity for the existence and non-existence of global solutions of the Cauchy problem. Moreover, the life span of solutions is also studied.
基金financial support from the Regional Government of Castilla-León(Project No.SA126G18)。
文摘Implications of the differences in leaf life span are still subject to debate in the field of ecophysiology.Since leaf traits associated with these differences may be decisive for determining the distribution of tree species,this topic is particularly relevant in the context of climate change.This study analyzes the effects of the differences in leaf life span on premature losses of leaf area owing to insect herbivory and to abiotic stress.Loss of leaf area may be an important determinant of total leaf carbon assimilation.Seven Mediterranean tree species,distributed on four sites with different climates were studied.The species exhibited strong differences in leaf life span and in leaf traits,especially leaf mass per unit area.Premature leaf area losses were estimated in response to insect herbivory and summer drought over two years.The results revealed that,despite having older leaf cohorts with more damage,species with longer leaf duration had lower area lost to herbivores and less damage due to accelerated senescence during the summer drought.With respect to the predicted increase in water stress,deciduous species are at a disadvantage due to their high premature loss of leaf area and thus loss of photosynthetic capacity.
文摘In this paper the authors consider Cauchy problem of first order quasilinear hyperbolic and prove that existence of its periodic solutions and estimates of life span of solutions. This results reveals the relationship of dissipation and smoothness of periodic solutions.
基金Project supported by the National Natural Science Foundation of China(No. 10571024)the Natural Science Foundation of Henan Province of China (No.200510078005)the Science Foundation of Educational Department of Henan Province of China (No.200511051700)
文摘The paper concerns Cauchy,problem for one-dimensional hydromagnetic dynamics with dissipative terms. When the dissipation coefficient is equal to zero it is shown that the smooth solutions develop shocks in the finite time if the initial amounts of entropy and magnetic field are smaller than those of sound waves; when it is larger than zero, and the initial amounts of entropyI this dissipation coefficient and the magnetic field in each period are smaller than those of sound Waves, then the smooth solutions blow up in the finite time. Moreover, the life-span of the smooth solution is given.
基金supported in part by the NNSF of China(11271323,91330105)the Zhejiang Provincial Natural Science Foundation of China(LZ13A010002)the Henan Provincial Natural Science Foundation of China(152300410226)
文摘In this article, we investigate the lower bound of life-span of classical solutions of the hyperbolic geometry flow equations in several space dimensions with ＂small＂ initial data. We first present some estimates on solutions of linear wave equations in several space variables. Then, we derive a lower bound of the life-span of the classical solutions to the equations with ＂small＂ initial data.
文摘Dietary γ-amino butyric acid (GABA) has been suggested to decrease systolic blood pressure. This study aimed to ex-amine the effects of dietary GABA on the life span of stroke-prone spontaneously hypertensive rats (SHRSPs). In this study, life span was determined for SHRSPs provided 1% NaCl solution or 0.01% GABA in 1% NaCl solution as drinking water. The life span of the GABA-fed group (76.3 ± 1.65 days) was significantly shorter than that of the control group (81.6 ± 0.88 days). The results of this study may not be applicable to humans. Future studies will be necessary to elucidate the mechanism underlying this phenomenon.
文摘Considering the insulators ageing in a mixture of PVC and dye, set following operating conditions and time to ensure proper operation and perfect safety of industrial installations using insulated conductors. The results showed that the insulation carried out by the L.C main office was a good quality (on thermal aspect), because the resistance of the insulation is so high (i.e. 3940 Mega Ohms under normal conditions). The results showed a lifespan of 50 years at a temperature of 40°C (close to ambient temperature), plus minus 33 years at a temperature of 70°C;plus minus 22 years at a temperature of 100°C and 12 years at a temperature of 160°C. Furthermore, information on chemical attack, the results showed that PVC cables have poor resistance to sulfuric acid attack (having a pH of 1.5 and a density of 1.84 g/cm<sup>3</sup>). LC/Gecamines is able to produce locally a good quality of electrical cables.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.11802168 and 51575331)project funded by China Postdoctoral Science Foundation(No.2019M661458)
文摘Owing to the complex environmental conditions, suspension could induce complicated forces on submarine pipelines and even cause vortex-induced vibration, resulting in fatigue damage of pipelines. Through aiming at the 28-inch submarine pipeline in the East China Sea, the pipeline was segmented according to the similarity, considering the factors of pipe assembly, typhoon, current, wave and seabed topography. The effects of span length on natural frequency in each section of submarine pipeline were analyzed by finite element model. The maximum safe span length allowed by each pipeline section was verified by fatigue cumulative damage theory, and the fatigue life of each pipeline section were predicted. The results showed that each order natural frequency of the pipeline decreased with the increase of span length. The calculated results of empirical formulas were much smaller than those of the FEM analysis. The increase of the gap between the suspended pipeline and the seabed was beneficial to enhance the fatigue life of the suspended pipeline.
