The paper reviews previous publications and reports some comments about a semi empirical model of the growth and decay process of a planktonic microbial culture. After summarizing and reshaping some fundamental mathem...The paper reviews previous publications and reports some comments about a semi empirical model of the growth and decay process of a planktonic microbial culture. After summarizing and reshaping some fundamental mathematical expressions, the paper highlights the reasons for the choice of a suitable time origin that makes the parameters of the model self-consistent. Besides the potential applications to predictive microbiology studies and to effects of bactericidal drugs, the model allows a suitable proxy of the fitness of the microbial culture, which can be of interest for the studies on the evolution across some thousand generations of a Long Term Evolution Experiment.展开更多
Population Growth and Decay study of the growth or the decrease of a population of a given entity, is carried out according to the environment. In an infinite environment, i.e. when the resources are unlimited, a popu...Population Growth and Decay study of the growth or the decrease of a population of a given entity, is carried out according to the environment. In an infinite environment, i.e. when the resources are unlimited, a population P believes according to the following differential equation P’ = KP, with the application of the differential calculus we obtasin an exponential function of the variable time (t). The function of which we can predict approximately a population according to the signs of k and time (t). If k > 0, we speak of the Malthusian croissant. On the other hand, in a finite environment i.e. when resources are limited, the population cannot exceed a certain value. and it satisfies the logistic equation proposed by the economist Francois Verhulst: P’ = P(1-P).展开更多
In this paper, we consider the nonlinearly damped semi-linear wave equation associated with initial and Dirichlet boundary conditions. We prove the existence of a local weak solution and introduce a family of potentia...In this paper, we consider the nonlinearly damped semi-linear wave equation associated with initial and Dirichlet boundary conditions. We prove the existence of a local weak solution and introduce a family of potential wells and discuss the invariants and vacuum isolating behavior of solutions. Furthermore, we prove the global existence of solutions in both cases which are polynomial and exponential decay in the energy space respectively, and the asymptotic behavior of solutions for the cases of potential well family with 0 〈 E(0) 〈 d. At last we show that the energy will grow up as an exponential function as time goes to infinity, provided the initial data is large enough or E(0) 〈 0.展开更多
In this paper, derived from Maxwell and fluid equations of plasmas, unified nonlinear wave equations are used to describe the parametric decay instability (PDI) in magnetized plasmas, and in view of mode-coupling, w...In this paper, derived from Maxwell and fluid equations of plasmas, unified nonlinear wave equations are used to describe the parametric decay instability (PDI) in magnetized plasmas, and in view of mode-coupling, we can obtain all the possible PDI channels. By solving the nonlinear equations with a mode-coupling method, we obtain the growth rate of the PDI, of which all of the three waves are ordinary mode (O-mode) or extraordinary mode (X-mode) wave. Under the dipole approximation, an explicit formula of the growth rate of the X-mode and the condition of the equilibrium density scale are obtained. According to the existence conditions of three X-mode waves, this kind of instability might exist in ECRH with the second harmonic X-mode wave.展开更多
The annual cycle of the thickness and temperature of landfast sea ice in the East Siberian Sea has been examined using a one-dimensional thermodynamic model. The model was calibrated for the year August 2012-July 2013...The annual cycle of the thickness and temperature of landfast sea ice in the East Siberian Sea has been examined using a one-dimensional thermodynamic model. The model was calibrated for the year August 2012-July 2013, forced using the data of the Russian weather station Kotel'ny Island and ECMWF reanalyses. Thermal growth and decay of ice were reproduced well, and the maximum annual ice thickness and breakup day became 1.64 m and the end of July. Oceanic heat flux was 2 W.m^-2 in winter and raised to 25 W.m^-2 in summer, albedo was 0.3-0.8 depending on the surface type (snow/ice and wet/dry). The model outcome showed sensitivity to the albedo, air temperature and oceanic heat flux. The modelled snow cover was less than 10 cm having a small influence on the ice thickness. In situ sea ice thickness in the East Siberian Sea is rarely available in publications. This study provides a method for quantitative ice thickness estimation by modelling. The result can be used as a proxy to understand the sea ice conditions on the Eurasian Arctic coast, which is important for shipping and high-resolution Arctic climate modelling.展开更多
Pollution by polycyclic aromatic hydrocarbons(PAHs) is widespread due to tmsuitable disposal of industrial waste. They are mostly defined as priority pollutants by environmental protection authorities worldwide. Phe...Pollution by polycyclic aromatic hydrocarbons(PAHs) is widespread due to tmsuitable disposal of industrial waste. They are mostly defined as priority pollutants by environmental protection authorities worldwide. Phenanthrene, a typical PAH, was selected as the target in this paper. The PAH-degrading mixed culture, named ZM, was collected from a petroleum contaminated river bed. This culture was injected into phenanthrene solutions at different concentrations to quantify the biodegradation process. Results show near-complete removal of phenanthrene in three days of biodegradation if the initial phenanthrene concentration is low. When the initial concentration is high, the removal rate is increased but 20%-40% of the phenanthrene remains at the end of the experiment. The biomass shows a peak on the third day due to the combined effects of microbial growth and decay. Another peak is evident for cases with a high initial concentration, possibly due to production of an intermediate metabolite. The pH generally decreased during biodegradation because of the production of organic acid. Two phenomenological models were designed to simulate the phenanthrene biodegradation and biomass growth. A relatively simple model that does not consider the intermediate metabolite and its inhibition of phenanthrene biodegradation cannot fit the observed data. A modified Monod model that considered an intermediate metabolite (organic acid) and its inhibiting reversal effect reasonably depicts the experimental results.展开更多
According to Fromm, the life instinct constitutes the primary potentiality in man, while the death instinct a secondary potentiality, and which of the two prevails depending crucially on the living conditions that the...According to Fromm, the life instinct constitutes the primary potentiality in man, while the death instinct a secondary potentiality, and which of the two prevails depending crucially on the living conditions that the subject experiences during his or her childhood. Not limited to the individual level, Fromm's observation works on the collective level as well. Different environments foster different potentialities and lead to the formation of different cultures and ethics. A biophilic ethics treasures the value of love, peace, reciprocal altruism and unity of being, while a biophobic ethics is more addicted to hatred, violence, dualistic confrontation, and mutual destruction. Appling Fromm's theory to the interpretation of Charles Johnson's Middle Passage, readers can get a newly enlightened understanding of this award-winning masterpiece. Based on Fromm's hypothesis about human nature, this article analyzes the representation of the confrontations between the biophobic ethics and the biophilic ethics in this novel, the former being embodied by Captain Falcon's "syndrome of decay" which is also Johnson's critical metaphor of Western civilization, while the latter embodied by the Allmuseri culture's "syndrome of growth" which represents Johnson's idealistic imagination of the sum of non-Western civilization展开更多
Disease resistance is often associated with compromised plant growth and yield due to defense-growth tradeoffs.However,key components and mechanisms underlying the defensegrowth tradeoffs are rarely explored in maize....Disease resistance is often associated with compromised plant growth and yield due to defense-growth tradeoffs.However,key components and mechanisms underlying the defensegrowth tradeoffs are rarely explored in maize.In this study,we find that ZmSKI3,a putative subunit of the SUPERKILLER(SKI)complex that mediates the 3′-5′degradation of RNA,regulates both plant development and disease resistance in maize.The Zmski3 mutants showed retarded plant growth and constitutively activated defense responses,while the ZmSKI3 overexpression lines are more susceptible to Curvularia lunata and Bipolaris maydis.Consistently,the expression of defense-related genes was generally up-regulated,while expressions of growth-related genes were mostly down-regulated in leaves of the Zmski3-1 mutant compared to that of wild type.In addition,223 differentially expressed genes that are up-regulated in Zmski3-1 mutant but down-regulated in the ZmSKI3 overexpression line are identified as potential target genes of ZmSKI3.Moreover,small interfering RNAs targeting the transcripts of the defense-and growth-related genes are differentially accumulated,likely to combat the increase of defense-related transcripts but decrease of growthrelated transcripts in Zmski3-1 mutant.Taken together,our study indicates that plant growth and immunity could be regulated by both ZmSKI3-mediated RNA decay and post-transcriptional gene silencing in maize.展开更多
The cumulative landfill gas (LFG) production and its rate were simulated for pretreated municipal solid waste (MSW) landfill using four models namely first order exponential model, modified Gompertz model, single ...The cumulative landfill gas (LFG) production and its rate were simulated for pretreated municipal solid waste (MSW) landfill using four models namely first order exponential model, modified Gompertz model, single component combined growth and decay model and Gaussian function. Considering the behavior of the pretreated MSW landfill, a new multi component model was based on biochemical processes that occurring in landfilled pretreated MSW. The model was developed on the basis of single component combined growth and decay model using an anaerobic landfill simulator reactor which treats the pretreated MSW. It includes three components of the degradation i.e. quickly degradable, moderately degradable and slowly degradable. Moreover, the devel- oped model was statistically analyzed for its goodness of fit. The results show that the multi components LFG production model is more suitable in comparison to the simulated models and can efficiently be used as a modeling tool for pretreated MSW landfills. The proposed model is likely to give assistance in sizing of LFG collection system, generates speedy results at lower cost, improves cost-benefit analysis and decreases LFG project risk. It also indicates the stabilization of the landfill and helps the managers in the reuse of the landfill space. The proposed model is limited to aerobically pretreated MSW landfill and also requires the values of delay times in LFG productions from moderately and slowly degradable fractions ofpretreated MSW.展开更多
文摘The paper reviews previous publications and reports some comments about a semi empirical model of the growth and decay process of a planktonic microbial culture. After summarizing and reshaping some fundamental mathematical expressions, the paper highlights the reasons for the choice of a suitable time origin that makes the parameters of the model self-consistent. Besides the potential applications to predictive microbiology studies and to effects of bactericidal drugs, the model allows a suitable proxy of the fitness of the microbial culture, which can be of interest for the studies on the evolution across some thousand generations of a Long Term Evolution Experiment.
文摘Population Growth and Decay study of the growth or the decrease of a population of a given entity, is carried out according to the environment. In an infinite environment, i.e. when the resources are unlimited, a population P believes according to the following differential equation P’ = KP, with the application of the differential calculus we obtasin an exponential function of the variable time (t). The function of which we can predict approximately a population according to the signs of k and time (t). If k > 0, we speak of the Malthusian croissant. On the other hand, in a finite environment i.e. when resources are limited, the population cannot exceed a certain value. and it satisfies the logistic equation proposed by the economist Francois Verhulst: P’ = P(1-P).
文摘In this paper, we consider the nonlinearly damped semi-linear wave equation associated with initial and Dirichlet boundary conditions. We prove the existence of a local weak solution and introduce a family of potential wells and discuss the invariants and vacuum isolating behavior of solutions. Furthermore, we prove the global existence of solutions in both cases which are polynomial and exponential decay in the energy space respectively, and the asymptotic behavior of solutions for the cases of potential well family with 0 〈 E(0) 〈 d. At last we show that the energy will grow up as an exponential function as time goes to infinity, provided the initial data is large enough or E(0) 〈 0.
基金supported by National Natural Science Foundation of China(Nos.10990214 and 115450)
文摘In this paper, derived from Maxwell and fluid equations of plasmas, unified nonlinear wave equations are used to describe the parametric decay instability (PDI) in magnetized plasmas, and in view of mode-coupling, we can obtain all the possible PDI channels. By solving the nonlinear equations with a mode-coupling method, we obtain the growth rate of the PDI, of which all of the three waves are ordinary mode (O-mode) or extraordinary mode (X-mode) wave. Under the dipole approximation, an explicit formula of the growth rate of the X-mode and the condition of the equilibrium density scale are obtained. According to the existence conditions of three X-mode waves, this kind of instability might exist in ECRH with the second harmonic X-mode wave.
基金supported by research funding from the National Natural Science Foundation of China (Grant nos. 41428603, 41376186, 41476170)the EU FP7 Project Eu Ru CAS(European-Russian Centre for Cooperation in the Arctic and Sub-Arctic Environmental and Climate Research,Grant no.295068)+2 种基金Academy of Finland (Grant nos. 11409391, 259537)the Liaoning Educational Committee Foundation (Grant no. L2013497)the Ocean Public Welfare Scientific Research Project of China (Grant nos. 201205007, 201205007-2)
文摘The annual cycle of the thickness and temperature of landfast sea ice in the East Siberian Sea has been examined using a one-dimensional thermodynamic model. The model was calibrated for the year August 2012-July 2013, forced using the data of the Russian weather station Kotel'ny Island and ECMWF reanalyses. Thermal growth and decay of ice were reproduced well, and the maximum annual ice thickness and breakup day became 1.64 m and the end of July. Oceanic heat flux was 2 W.m^-2 in winter and raised to 25 W.m^-2 in summer, albedo was 0.3-0.8 depending on the surface type (snow/ice and wet/dry). The model outcome showed sensitivity to the albedo, air temperature and oceanic heat flux. The modelled snow cover was less than 10 cm having a small influence on the ice thickness. In situ sea ice thickness in the East Siberian Sea is rarely available in publications. This study provides a method for quantitative ice thickness estimation by modelling. The result can be used as a proxy to understand the sea ice conditions on the Eurasian Arctic coast, which is important for shipping and high-resolution Arctic climate modelling.
基金The National Natural Science Foundation of China (No. 50178040) the Royal Society of UK and the Hi-Tech Research and Development Program(863) of China(No. 2003AA601080)
文摘Pollution by polycyclic aromatic hydrocarbons(PAHs) is widespread due to tmsuitable disposal of industrial waste. They are mostly defined as priority pollutants by environmental protection authorities worldwide. Phenanthrene, a typical PAH, was selected as the target in this paper. The PAH-degrading mixed culture, named ZM, was collected from a petroleum contaminated river bed. This culture was injected into phenanthrene solutions at different concentrations to quantify the biodegradation process. Results show near-complete removal of phenanthrene in three days of biodegradation if the initial phenanthrene concentration is low. When the initial concentration is high, the removal rate is increased but 20%-40% of the phenanthrene remains at the end of the experiment. The biomass shows a peak on the third day due to the combined effects of microbial growth and decay. Another peak is evident for cases with a high initial concentration, possibly due to production of an intermediate metabolite. The pH generally decreased during biodegradation because of the production of organic acid. Two phenomenological models were designed to simulate the phenanthrene biodegradation and biomass growth. A relatively simple model that does not consider the intermediate metabolite and its inhibition of phenanthrene biodegradation cannot fit the observed data. A modified Monod model that considered an intermediate metabolite (organic acid) and its inhibiting reversal effect reasonably depicts the experimental results.
基金Acknowledgement: This research is funded by the National Planning Office of Philosophy and Social Science of China (Reference 14CWW022), and by the China Postdoctoral Science Foundation (Reference 2014M552063).
文摘According to Fromm, the life instinct constitutes the primary potentiality in man, while the death instinct a secondary potentiality, and which of the two prevails depending crucially on the living conditions that the subject experiences during his or her childhood. Not limited to the individual level, Fromm's observation works on the collective level as well. Different environments foster different potentialities and lead to the formation of different cultures and ethics. A biophilic ethics treasures the value of love, peace, reciprocal altruism and unity of being, while a biophobic ethics is more addicted to hatred, violence, dualistic confrontation, and mutual destruction. Appling Fromm's theory to the interpretation of Charles Johnson's Middle Passage, readers can get a newly enlightened understanding of this award-winning masterpiece. Based on Fromm's hypothesis about human nature, this article analyzes the representation of the confrontations between the biophobic ethics and the biophilic ethics in this novel, the former being embodied by Captain Falcon's "syndrome of decay" which is also Johnson's critical metaphor of Western civilization, while the latter embodied by the Allmuseri culture's "syndrome of growth" which represents Johnson's idealistic imagination of the sum of non-Western civilization
基金supported by grants from National Key Research and Development program(2022YFD1201801 to M.G.)National Natural Science Foundation of China(U2004207,32372208 to M.G.32372179 to J.L.)+2 种基金Henan Province Major Science and Technology Project(221100110300,to J.T.)Distinguished Young Scholars in Henan(212300410007,to MG)Henan Province Joint Fund for Science and Technology Research(222103810003 to J.L.232103810004 to Y.Y.)。
文摘Disease resistance is often associated with compromised plant growth and yield due to defense-growth tradeoffs.However,key components and mechanisms underlying the defensegrowth tradeoffs are rarely explored in maize.In this study,we find that ZmSKI3,a putative subunit of the SUPERKILLER(SKI)complex that mediates the 3′-5′degradation of RNA,regulates both plant development and disease resistance in maize.The Zmski3 mutants showed retarded plant growth and constitutively activated defense responses,while the ZmSKI3 overexpression lines are more susceptible to Curvularia lunata and Bipolaris maydis.Consistently,the expression of defense-related genes was generally up-regulated,while expressions of growth-related genes were mostly down-regulated in leaves of the Zmski3-1 mutant compared to that of wild type.In addition,223 differentially expressed genes that are up-regulated in Zmski3-1 mutant but down-regulated in the ZmSKI3 overexpression line are identified as potential target genes of ZmSKI3.Moreover,small interfering RNAs targeting the transcripts of the defense-and growth-related genes are differentially accumulated,likely to combat the increase of defense-related transcripts but decrease of growthrelated transcripts in Zmski3-1 mutant.Taken together,our study indicates that plant growth and immunity could be regulated by both ZmSKI3-mediated RNA decay and post-transcriptional gene silencing in maize.
文摘The cumulative landfill gas (LFG) production and its rate were simulated for pretreated municipal solid waste (MSW) landfill using four models namely first order exponential model, modified Gompertz model, single component combined growth and decay model and Gaussian function. Considering the behavior of the pretreated MSW landfill, a new multi component model was based on biochemical processes that occurring in landfilled pretreated MSW. The model was developed on the basis of single component combined growth and decay model using an anaerobic landfill simulator reactor which treats the pretreated MSW. It includes three components of the degradation i.e. quickly degradable, moderately degradable and slowly degradable. Moreover, the devel- oped model was statistically analyzed for its goodness of fit. The results show that the multi components LFG production model is more suitable in comparison to the simulated models and can efficiently be used as a modeling tool for pretreated MSW landfills. The proposed model is likely to give assistance in sizing of LFG collection system, generates speedy results at lower cost, improves cost-benefit analysis and decreases LFG project risk. It also indicates the stabilization of the landfill and helps the managers in the reuse of the landfill space. The proposed model is limited to aerobically pretreated MSW landfill and also requires the values of delay times in LFG productions from moderately and slowly degradable fractions ofpretreated MSW.