Two revised drafts about a simple evolution trade off function studied by Mitchell(Mitchell, 2000) were put up first. Considering the complex of the environment, or the nonlinear interaction of the environment and sp...Two revised drafts about a simple evolution trade off function studied by Mitchell(Mitchell, 2000) were put up first. Considering the complex of the environment, or the nonlinear interaction of the environment and species, we put up two new cost functions:c(u,z)=c 0+c 1u+k(z+az 2)u,u>0;c(u,z)=c 0+c 1u+kz du,u>0,d>0. In the first case, if the environment is adverse to species ( a >0), the region of low stress which is more suitable for the intolerant species is very small, and at the same environment stress z , the tolerant species will pay the more cost than it will paid in the normal environment. However the tolerant species will pay more cost but low strategies in the environment of a <0 than that it will paid in the environment of a =0 or a >0. In the second case, the results showed that the greater the stress of the environment is, or the more complex the environment is, the lower cost the intolerant species will pay in the region of z <1. In order to exist or to evolve from an environment of high stress, the organisms must possess a higher u , or a better means of mitigating of the stress of environment. Meanwhile in the region d >1, when d decrease, the intolerant species will pays more lower cost of exploiting a habitat in the low stress environment while the tolerant one will pays more lower cost in the high stress environment. This means that scale d describes the selection character of the species system in the evolution process, the smaller the d(d <1) is, the better the selection or the mitigation the system will possesses.展开更多
Melatonin is a multifunctional molecule found in all organisms that has been shown to play a crucial role in plant growth, development, and stress response. Plant melatonin is typically synthesized in organelles terme...Melatonin is a multifunctional molecule found in all organisms that has been shown to play a crucial role in plant growth, development, and stress response. Plant melatonin is typically synthesized in organelles termed chloroplasts, and the mechanisms of its synthesis and metabolic pathways have been extensively studied. Melatonin serves a significant regulatory function in plant growth and development, influencing the morphological and physiological characteristics of plants by modulating biological processes. While studies on plant melatonin receptors are in their early stages compared to studies in animal receptors, the binding mechanism with melatonin is now recognized as the key initiating step that triggers a series of downstream protective effects. This suggests that melatonin in plants may exert its effects through two main modes of target binding. The CAND2/PMTR1 protein binds to melatonin with a high degree of affinity. This binding activates downstream heterotrimeric G proteins, which trigger rapid intracellular signaling cascades. These cascades include activating the MAPK pathway and modulating ion channel activity. This action swiftly regulates stomatal closure in response to physiological processes such as drought stress. Additionally, melatonin has been demonstrated to regulate the plant stress response through two main mechanisms. First, it directly inhibits the accumulation of reactive oxygen species. Second, it indirectly influences the stress response pathways. This paper examines plant melatonin from three perspectives: the synthesis pathways of melatonin, its effects on plant growth, and its applications in plants under stress. Finally, the prospects for melatonin study and its applications in plants are discussed.展开更多
Stress in plants refers to adverse changes in their functioning.The occurrence and intensity of a stress can be assessed by alterations in plant traits,termed stress indicators.The ultimate goal of this study was to t...Stress in plants refers to adverse changes in their functioning.The occurrence and intensity of a stress can be assessed by alterations in plant traits,termed stress indicators.The ultimate goal of this study was to test whether six morpho-physiological plant traits,frequently used as stress indicators,respond consistently across species to various environmental stressors,with the aim of detecting universal stress indicators in forest tree species.We examined changes in vertical increment,leaf/needle size,shoot length,needle longevity,photosynthetic efficiency and fluctuating asymmetry in three common European tree species,mountain birch(Betula pubescens var.pumila),Norway spruce(Picea abies)and Scots pine(Pinus sylvestris)along three environmental gradients(elevation,pollution and seashore)from forests to stressful open environments.Data were collected in 2003,2004 and 2005 from 297 trees growing naturally across 36 sites in north-western Russia.Fluctuating asymmetry was the only trait that did not vary among sites with differing levels of environmental stress.Leaf/needle size and shoot length occasionally changed along stress gradients,but the magnitude and direction of these changes differed by gradient type and species,resulting in no significant overall stress effect for either trait.In contrast,photosynthetic efficiency,vertical increment and needle longevity consistently decreased from low-stress to high-stress sites.The overall effect was significant for each of these three traits despite the magnitudes of these decreases differed depending on the gradient type and location,species,study year and individual tree.Replication at spatial,temporal and taxonomic levels ensured the robustness and reliability of our results that photosynthetic efficiency,vertical growth and needle longevity reliably captured a general stress syndrome and may serve as stress indicators in forest species.展开更多
Plantshave evolvedvariousmechanismsto interact withmicroorganisms,which help them acquire nutrients from the soil and enhance their tolerance to environmental stresses.One of the most widespread mutualistic interactio...Plantshave evolvedvariousmechanismsto interact withmicroorganisms,which help them acquire nutrients from the soil and enhance their tolerance to environmental stresses.One of the most widespread mutualistic interactions is arbuscular mycorrhizal(AM)symbiosis,which is formed by 80%-90%of terrestrial plants in association with AM fungi.In AM symbiosis,plants acquire mineral nutrients from the fungi in exchange for fatty acids and sugars that are produced during photosynthesis(Jiang et al.,2017).展开更多
Associating environmental stresses （ESs） with built-in test （BIT） output is an important means to help diagnose intermittent faults （IFs）. Aiming at low efficiency in association of traditional time stress measu...Associating environmental stresses （ESs） with built-in test （BIT） output is an important means to help diagnose intermittent faults （IFs）. Aiming at low efficiency in association of traditional time stress measurement device （TSMD）, an association model is built. Thereafter, a novel approach is given to evaluate the integrated environmental stress （IES） level. Firstly, the selection principle and approach of main environmental stresses （MESs） and key characteristic parameters （KCPs） are presented based on fault mode, mechanism, and ESs analysis （FMMEA）. Secondly, reference stress events （RSEs） are constructed by dividing IES into three stress levels according to its impact on faults; and then the association model between integrated environmental stress event （IESE） and BIT output is built. Thirdly, an interval grey association approach to evaluate IES level is proposed due to the interval number of IES value. Consequently, the association output can be obtained as well. Finally, a case study is presented to demonstrate the proposed approach. Results show the proposed model and approach are effective and feasible. This approach can be used to guide ESs measure, record, and association. It is well suited for on-line assistant diagnosis of faults, especially IFs.展开更多
Multiplex environmental factors are generally expected to have significant effects on genetic diversity of plant populations.In this study,randomly amplified polymorphic DNA（RAPD） technique was used to reveal the ge...Multiplex environmental factors are generally expected to have significant effects on genetic diversity of plant populations.In this study,randomly amplified polymorphic DNA（RAPD） technique was used to reveal the genetic diversity in the same species of four populations collected from Niupidujuan（Rhododendron chrysanthum） at different altitudes,an endangered species,endemic to Northeast China.Initially,twenty informative and reproducible primers were chosen for final RAPD analysis.A total of 152 clear bands were obtained,including 143 polymorphic ones.With the help of POPGENE software,the poly rate was calculated to be 94.07% and the evenness of amplified bands for every primer was 6.8.Additionally,the mean observed number of alleles was 1.7265 with an effective number of 1.3608.An examination of the gene indicated a diversity of 0.2162 with an information diversity index of 0.3313.For these data,the clustering blurred analysis was performed with the aid of NTSYS-pc software to define the Nei＇s gene diversity and the Shannon information diversity index of the four plant populations.The relationships between the genetic diversity indexes on the one hand and the geographic and climatic factors on the other hand were estimated by the Pearson correlation with SPSS 11.0 software.The results of the correlation analysis show that there were significant（P〈0.05） or highly significant（P〈0.01） correlations between each of the genetic diversity indexes and the different temperature which were mainly caused by the altitude different populations located.These data highlight the importance of native populations in shaping the spatial genetic structure in Niupidujuan.展开更多
In order to evaluate the relationships between temporal species succession of planktonic protists and physical-chemical parameters in semi-enclosed mariculture waters, species distributions in response to environmenta...In order to evaluate the relationships between temporal species succession of planktonic protists and physical-chemical parameters in semi-enclosed mariculture waters, species distributions in response to environmental stress were investigated in a shrimp-farming pond near Qingdao, China during a complete shrimp-culture cycle （May to October 2002）. A clear temporal succession in species distribution was found over the complete farming cycle. For example, before the introduction of the shrimp larvae there was low-variability of species distribution in the protist communities whereas during the stages immediately after, there was higher variability in species composition. Multiple linear/logistic regression analyses demonstrate that 12 protist taxa （e.g., Gyrodinium spirale, Teleaulax acuta, Prorocentrum spp. and Mesodinium pupula） were related to the nutrients, in particular ammonia and phosphates, alone or in combination with water temperature. These results suggest that temporal variations in species distribution of planktonic protist communities might be used in assessing water quality of semi-enclosed mariculture waters.展开更多
Lonicera japonica Thunb.is widely distributed in China.It has strong adaptability to the environment and can maintain normal growth and development under a variety of stress conditions.It is commonly used as a medicin...Lonicera japonica Thunb.is widely distributed in China.It has strong adaptability to the environment and can maintain normal growth and development under a variety of stress conditions.It is commonly used as a medicine with its dry flower buds or newly opened flowers,named honeysuckle,and with both economic value and ecological application value.The research progress of L.japonica Thunb.under stress conditions such as temperature,drought,light,salt,heavy metals and diseases,pests and endophytic bacteria was reviewed,and the current research situation of the physiological and biochemical response mechanism,changes of photosynthetic fluorescence and accumulation of secondary metabolites of honeysuckle under different stresses was discussed,so as to provide a reference for deep-level exploring the resistance mechanism of L.japonica Thunb.in the future and lay a theoretical foundation for the high-quality authentic ecological cultivation of L.japonica Thunb.展开更多
The gut microbiota has gained attention because of its importance in facilitating host survival and evolution.However,it is unclear whether gut microbial communities are determined by the host(heritable factor) or env...The gut microbiota has gained attention because of its importance in facilitating host survival and evolution.However,it is unclear whether gut microbial communities are determined by the host(heritable factor) or environment(environmental factor).In this study,we investigated the gut microbial communities and potential functional signatures of two sympatric species distributed along an elevation gradient,the toadheaded lizards Phrynocephalus axillaris and P.forsythii.Our results indicated that at high elevations,the gut microbial communities of P.axillaris and P.forsythii did not significantly differ,and the phylogenetic relationships of gut microbial communities contradicted their hosts.At low altitudes,the two lizards could be distinguished based on their significantly different gut microbial communities.Compared to low-altitude populations,Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis showed that at higher altitudes,energy metabolism,such as carbohydrate,lipid,and amino acids metabolism were higher in both lizards.While a larger number of pathogenic bacteria were found in the lowaltitude population of P.forsythii.This suggests that the convergence of gut microbiota of two lizards at highaltitude stem from environmental factors,as they were exposed to the same environmental stress,whereas the divergence at low-altitude stemmed from heritable factors,as they were exposed to different environmental stresses.These results provide a new perspective regarding whether heritable or environmental factors dominate the gut microbiota during exposure to environmental stress.展开更多
Sap flow and environmental conditions were monitored at two Eucalyptus (Eucalyptus urophylla S.T.Blake) plantations at Hetou and Jijia, located in Leizhou, Zhanjiang, Guangdong Province. It was found that daily sap fl...Sap flow and environmental conditions were monitored at two Eucalyptus (Eucalyptus urophylla S.T.Blake) plantations at Hetou and Jijia, located in Leizhou, Zhanjiang, Guangdong Province. It was found that daily sap flux density (SFD) of Eucalyptus was closely related to daily atmospheric vapor pressure deficit (VPD) (R2=0.76, P=0.01 at Hetou and R2=0.7021, P=0.01 at Jijia) at both sites. No significant relationship existed between daily SFD and mean daily air temperature at both sites. Daily SFD varied with wind speed Y=-17585X3+15147X2-1250.7X+2278.4 (R2=0.68; P=0.01) at Hetou and Y=-101.67X3-1.65X2-376.4X+1914.8 (R2=0.40,P=0.05) at Jijia, where Y was daily SFD,X was daily wind speed. Experimental observations yielded the following data: (1) the critical lower and upper daily VPD threshold were 0 and 2 kPa, within which daily SFD varied from 540±70 L/(m2·d) to 4739±115 L/(m2·d) at Hetou site, from 397±26 L/(m2·d) to 3414±191 L/(m2·d) at Jijia site; (2) Diurnal SFDs at Hetou site were much higher under low relative humidity (<30%) and slightly lower under high relative humidity (>%) compared with those at the Jijia site; (3) The upper and lower threshold of daily and diurnal RAD for the optimal water use of E. urophylla plantations were 18±2.7 and 2±1 MJ/(m2·d), 669 and 0 J/(cm2·h) during the observation period.展开更多
Clinical studies have suggested that internal and/or external aversive cues may produce a negative affective-motivational component whereby maladaptive responses(plasticity)of dural afferent neurons are initiated cont...Clinical studies have suggested that internal and/or external aversive cues may produce a negative affective-motivational component whereby maladaptive responses(plasticity)of dural afferent neurons are initiated contributing to migraine chronification.However,pathophysiological processes and neural circuitry involved in aversion(unpleasantness)-producing migraine chronification are still evolving.An interdisciplinary team conducted this narrative review aimed at reviewing neuronal plasticity for developing migraine chronicity and its relevant neurocircuits and providing the most cutting-edge information on neuronal mechanisms involved in the processing of affective aspects of pain and the role of unpleasantness evoked by internal and/or external cues in facilitating the chronification process of migraine headache.Thus,information presented in this review promotes the understanding of the pathophysiology of chronic migraine and contribution of unpleasantness(aversion)to migraine chronification.We hope that it will bring clinicians’attention to how the maladaptive neuroplasticity of the emotion brain in the aversive environment produces a significant impact on the chronification of migraine headache,which will in turn lead to new therapeutic strategies for this type of pain.展开更多
Background:The biomechanical environment created by suture-button fixation Latarjet is conducive to the healing and shaping of the transplanted coracoid,but its mechanism remains unclear.The latest research has found ...Background:The biomechanical environment created by suture-button fixation Latarjet is conducive to the healing and shaping of the transplanted coracoid,but its mechanism remains unclear.The latest research has found that the absence of stem cell chemokine(CXCL12)impeded bone regeneration in Sonic Hedgehog(SHH)-deficient animals.However,whether the biomechanical environment affects SHH and CXCL12 function has not been studied.Methods:Rat fracture models were constructed to simulate stress environments under non-l oad-bearing and load-bearing conditions.The fracture healing and shaping,as well as the expression levels of SHH and CXCL12,were assessed through gross viewing,micro-computed tomography(micro-CT),and histochemical staining.Results:Under flexible fixation,the relative bone volume(BV/TV)of rats exposed to the load-bearing stress environment was significantly higher than that of rats under a non-l oad-bearing stress environment(p≤0.05).Adverse bone shaping was not observed in rats subjected to flexible fixation.The levels of SHH and CXCL12in load-bearing rats exhibited significant elevation(p≤0.05).Under a load-bearing stress environment,no significant difference was observed in the BV/TV between the flexible fixation group and the rigid fixation group(p≥0.05),but there was excessive hyperplasia of the fracture callus in the rigid fixation group.The levels of SHH and CXCL12 in rats subjected to rigid fixation were significantly elevated(p≤0.05).Conclusions:Flexible fixation and load-bearing stress environment may contribute to bone healing and shaping by influencing the levels of SHH and CXCL12,suggested that this mechanism may be relevant to the healing and shaping of the transplanted coracoid after suture-button fixation Latarjet.展开更多
[Objective] The study aimed to analyze the eco-environrnental stress trend of Inner Mongolia using ecological stress index method. [Methed] On the basis of the improved ecological stress index （ESI） analysis method,...[Objective] The study aimed to analyze the eco-environrnental stress trend of Inner Mongolia using ecological stress index method. [Methed] On the basis of the improved ecological stress index （ESI） analysis method, the eco-environmental stress trend of Inner Mongolia from 1996 to 2009 was analyzed, as well as the changes of eco-environmental stress in major industrial cities of Inner Mongolia in 2008. [ Result] With the economic development of Inner Mongolia from 1996 to 2009, the U-shape change could be found in the eco-environmental stress, showing an upward trend on the whole, especially since 2003, and there was a sharp raise in the environmental pollution index. In addition, the eco-enviren- mental stress lessened in most major cities of Inner Mongolian in 2008, but it was in a polarization state, that is, Baotou, Wuhai and Hohhot biased resource and energy consumption, while Ordos and Chifeng biased environmental pollution. [ Conclusion] The research could provide scientific ref- erences for the protection of ecological environment and the adjustment of industrial structure in Inner Mongolia.展开更多
In order to evaluate the influence of stressed environments on hepatopancreatic cells of fre- shwater prawns, Macrobachium borellii Nobili, 1896 and Palaemonetes argentinus Nobili 1901, (Crustacea, Decapoda, Palaemoni...In order to evaluate the influence of stressed environments on hepatopancreatic cells of fre- shwater prawns, Macrobachium borellii Nobili, 1896 and Palaemonetes argentinus Nobili 1901, (Crustacea, Decapoda, Palaemonidae) were collected at three different aquatic environments with different relationship to urban development in Argentina. Furthermore the effects of several cypermethryn concentration on hepa- topancreatic cell of M. borellii and P. argentinus were evaluated in a laboratory assays. The “N°1” lake (Santa Fe Argentina) which is more affected by the anthropogenic pressure and “Don Felipe” lake which is still not strongly by human activities were the studied sites from the floodplain of Paranáriver. While Alejandra lake was the intermedia effects sites. Different damaged ultra-structures were found in F- and R-cells of prawns in the stressed lake. The predominant features were: disrupted the microvillous border, swelled mitochondria, reduction of endoplasmic reticulum, dyctiosomes, glycoproteins, desna-turalization of vacuole membrane and premature autolysis. Moreover the F-cell number was higher in the environment near to city than in the others sites. Similar effects were observed in the cypermethryn assays. The observations clearly indicate that the ultrastructure of midgut gland in the both palaemonids varies depending on the site from which animals are collected and the biocid presence. So, in this case it can be stated that the hepatopancreas histology of fre- shwater prawns is a good tool to monitor the impact of a stressed environment upon freshwater prawns.展开更多
Antibiotic resistant Escherichia coli strains are becoming more common recently. OmpA is a very important antigen protein of E. coli, which consists of two separate domains, N-terminal and C-terminal domain. The N-ter...Antibiotic resistant Escherichia coli strains are becoming more common recently. OmpA is a very important antigen protein of E. coli, which consists of two separate domains, N-terminal and C-terminal domain. The N-terminal domain contains eight β- barrel regions that plays important roles in the multifaceted functions of OmpA. In the present study, we cloned a mutant OmpA gene from a multi-antibiotic resistant E. coli strain. Sequence analysis indicated that the N-terminal DNA sequence of the mutant OmpA shared 81.05% homology with the modeled OmpA from E. coli K12 and the N-terminal amino acid sequence of the mutant OmpA was 81.22% identical to that of the E. coli K12 OmpA. Moreover, several amino acids located in the β-barrel region were mutated. The mutant OmpA was expressed in BL21 suggested by SDS-PAGE. Resistance to environmental stress assay indicated that the N-terminus mutant OmpA still possessed excellent activities in pH, temperature and osmotic pressure resistance. Our pre- sent study may supply insights into better and deeper understand the relationships between OmpA N-terminal regions and its functions in environmental stress conditions and the mechanisms on antibiotic resistance of E. coli.展开更多
Pollution by various heavy metals as environmental stress factors might affect bacteria. It was established that iron（Fe（Ⅲ））, manganese（Mn（Ⅱ）） and copper（Cu（Ⅱ）） ion combinations caused effects on Entero...Pollution by various heavy metals as environmental stress factors might affect bacteria. It was established that iron（Fe（Ⅲ））, manganese（Mn（Ⅱ）） and copper（Cu（Ⅱ）） ion combinations caused effects on Enterococcus hirae that differed from the sum of the effects when the metals were added separately. It was shown that the Cu2＋–Fe3＋combination decreased the growth and ATPase activity of membrane vesicles of wild-type E. hirae ATCC9790 and atp D mutant（with defective FoF1-ATPase） MS116. Addition of Mn2＋–Fe3＋combinations within the same concentration range had no effects on growth compared to control（without heavy metals）. ATPase activity was increased in the presence of Mn2＋–Fe3＋, while together with0.2 mmol/L N,N′-dicyclohexylcarbodiimide（DCCD）, ATPase activity was decreased compared to control（when only 0.2 mmol/L DCCD was present）. These results indicate that heavy metals ion combinations probably affect the FOF1-ATPase, leading to conformational changes. Moreover the action may be direct or be mediated by environment redox potential.The effects observed when Fe3＋was added separately disappeared in both cases, which might be a result of competing processes between Fe3＋and other heavy metals. These findings are novel and improve the understanding of heavy metals ions effects on bacteria,and could be applied for regulation of stress response patterns in the environment.展开更多
Environmental stress is used as an indicator of the overall pressure on regional environmental systems caused by the output of various pollutants as a result of human activities. Based on the pollutant emissions and s...Environmental stress is used as an indicator of the overall pressure on regional environmental systems caused by the output of various pollutants as a result of human activities. Based on the pollutant emissions and socioeconomic databases of the counties in Beijing–Tianjin–Hebei region, this paper comprehensively calculates the environmental stress index(ESI) for the urban agglomeration using the entropy weight method(EWM) at the county scale and analyzes the spatiotemporal patterns and the differences among the four types of major functional zones(MFZ) for the period 2012–2016. In addition, the socioeconomic driving forces of environmental stress are quantitatively estimated using the geographically weighted regression(GWR) method based on the STIRPAT model framework. The results show that:(1) The level of environmental stress in the Beijing–Tianjin–Hebei region was significantly alleviated during that time period, with a decrease in ESI of 54.68% by 2016. This decrease was most significant in Beijing, Tangshan, Tianjin, Shijiazhuang, and other central urban areas, as well as the Binhai New Area. The level of environmental stress in counties decreased gradually from the central urban areas to the suburban areas, and the high-level stress counties were eliminated by 2016.(2) The spatial spillover effect of environmental stress increased further at the county scale from 2012 to 2016, and spatial locking and path dependence emerged in the cities of Tangshan and Tianjin.(3) Urbanized zones(development-optimized and development-prioritized zones) were the major areas bearing environmental pollution in the Beijing–Tianjin–Hebei region in that time period. The ESI accounted for 65.98% of the whole region, where there was a need to focus on the prevention and control of environmental pollution.(4) The driving factors of environmental stress at the county scale included population size and the level of economic development. In addition, the technical capacity of environmental waste disposal, the intensity of agricultural production input, the intensity of territorial development, and the level of urbanization also had a certain degree of influence.(5) There was spatial heterogeneity in the effects of the various driving factors on the level of environmental stress. Thus, it was necessary to adopt differentiated environmental governance and reduction countermeasures in respect of emission sources, according to the intensity and spatiotemporal differences in the driving forces in order to improve the accuracy and adaptability of environmental collaborative control in the Beijing–Tianjin–Hebei region.展开更多
Fluorescence correlation spectroscopy （FCS） without objective image magnification （without using con-focal microscope） was applied to observe the variation in cell size of Escherichia coli （E. coli） induced by t...Fluorescence correlation spectroscopy （FCS） without objective image magnification （without using con-focal microscope） was applied to observe the variation in cell size of Escherichia coli （E. coli） induced by the anti-cancer agent MitomycinC （MMC）. In the system without image magnification followed in this study, the suspension of E. coli cells was stirred, and the difference in movement due to the different cell sizes induced by the compulsive solution flow was detected. The addition of 0.1-0.4 pg/L of MMC elongated the E. coli cell length from about 3.6 to 7.8μm. The flow cell （i.d. = about 1 mm） also produced a size-dependent correlation curve, The present system is not based on single molecular FCS but is inexpensive and effective at observing the variation in cell size induced by environmental changes.展开更多
The environment shear stress of Tangshan main earthquake and 38 great aftershocks have been calculated by the acceleration data of Tangshan earthquake sequence. The environment shear stress for 52 smaller aftershocks ...The environment shear stress of Tangshan main earthquake and 38 great aftershocks have been calculated by the acceleration data of Tangshan earthquake sequence. The environment shear stress for 52 smaller aftershocks from July of 1982 to July of 1984 have also been calculated by use of the digital data of the Sino-American cooperation recorded by the instrumental arrays in Tangshan. The results represent that the environment shear stress τ0 values have a weak dependence on the seismic moment, only the small and moderate earthquakes will be able to occur in the region with smaller τ0 value and the large earthquakes are only in the region with greater τ0 value. The peak acceleration, velocity and displacement will be larger for the earthquakes occurred in the region with greater τ0 value, Therefore, the measurement of environment shear stress τ0 value for the significant region will play an important role in earthquske prediction and engineering shock-proof. The environment shear stress values for the great aftershocks occurred in the two ends of the main fault are often higher than that for the main shock. This case may represent the stress concentration in the two ends of the fault. This phenomenon provides the references for the place where the great aftershock will occur.展开更多
Environmental stress model is proposed as an effective tool to the analysis and evaluation of navigational safety in ports and waterways. Marine traffic simulations are carried out in a virtual port area with various ...Environmental stress model is proposed as an effective tool to the analysis and evaluation of navigational safety in ports and waterways. Marine traffic simulations are carried out in a virtual port area with various arrangements and conditions. Calculations of stress values and traffic volume criteria are illustrated. The simulation results provide a valuable hint for safety management of vessel traffic. The model provides quantitative information and helps administrators in decision making to achieve desired safety level and improve the efficiency of vessel traffic in ports and waterways.展开更多
文摘Two revised drafts about a simple evolution trade off function studied by Mitchell(Mitchell, 2000) were put up first. Considering the complex of the environment, or the nonlinear interaction of the environment and species, we put up two new cost functions:c(u,z)=c 0+c 1u+k(z+az 2)u,u>0;c(u,z)=c 0+c 1u+kz du,u>0,d>0. In the first case, if the environment is adverse to species ( a >0), the region of low stress which is more suitable for the intolerant species is very small, and at the same environment stress z , the tolerant species will pay the more cost than it will paid in the normal environment. However the tolerant species will pay more cost but low strategies in the environment of a <0 than that it will paid in the environment of a =0 or a >0. In the second case, the results showed that the greater the stress of the environment is, or the more complex the environment is, the lower cost the intolerant species will pay in the region of z <1. In order to exist or to evolve from an environment of high stress, the organisms must possess a higher u , or a better means of mitigating of the stress of environment. Meanwhile in the region d >1, when d decrease, the intolerant species will pays more lower cost of exploiting a habitat in the low stress environment while the tolerant one will pays more lower cost in the high stress environment. This means that scale d describes the selection character of the species system in the evolution process, the smaller the d(d <1) is, the better the selection or the mitigation the system will possesses.
基金supported by National College Student Innovation and Entrepreneurship Train-ing Program(202410376009)Anhui Province College Student Innovation and Entrepreneurship Training Program(S202310376057,S202510376030)+2 种基金Quality Engineering Project of West Anhui University(wxxy2024011)Quality Engineering Project of Anhui Province(2024zybj032)Development of Big Data Integration and Analysis Platform for Traditional Chinese Medicine Genomics(0045025050).
文摘Melatonin is a multifunctional molecule found in all organisms that has been shown to play a crucial role in plant growth, development, and stress response. Plant melatonin is typically synthesized in organelles termed chloroplasts, and the mechanisms of its synthesis and metabolic pathways have been extensively studied. Melatonin serves a significant regulatory function in plant growth and development, influencing the morphological and physiological characteristics of plants by modulating biological processes. While studies on plant melatonin receptors are in their early stages compared to studies in animal receptors, the binding mechanism with melatonin is now recognized as the key initiating step that triggers a series of downstream protective effects. This suggests that melatonin in plants may exert its effects through two main modes of target binding. The CAND2/PMTR1 protein binds to melatonin with a high degree of affinity. This binding activates downstream heterotrimeric G proteins, which trigger rapid intracellular signaling cascades. These cascades include activating the MAPK pathway and modulating ion channel activity. This action swiftly regulates stomatal closure in response to physiological processes such as drought stress. Additionally, melatonin has been demonstrated to regulate the plant stress response through two main mechanisms. First, it directly inhibits the accumulation of reactive oxygen species. Second, it indirectly influences the stress response pathways. This paper examines plant melatonin from three perspectives: the synthesis pathways of melatonin, its effects on plant growth, and its applications in plants under stress. Finally, the prospects for melatonin study and its applications in plants are discussed.
基金supported by the Research Council(formerly Academy)of Finland(projects 122133,214824,362731,and researcher posts of M.V.Kozlov)EC through the BALANCE project carried out under contract EVK2-2002-00169,and the University of Turku。
文摘Stress in plants refers to adverse changes in their functioning.The occurrence and intensity of a stress can be assessed by alterations in plant traits,termed stress indicators.The ultimate goal of this study was to test whether six morpho-physiological plant traits,frequently used as stress indicators,respond consistently across species to various environmental stressors,with the aim of detecting universal stress indicators in forest tree species.We examined changes in vertical increment,leaf/needle size,shoot length,needle longevity,photosynthetic efficiency and fluctuating asymmetry in three common European tree species,mountain birch(Betula pubescens var.pumila),Norway spruce(Picea abies)and Scots pine(Pinus sylvestris)along three environmental gradients(elevation,pollution and seashore)from forests to stressful open environments.Data were collected in 2003,2004 and 2005 from 297 trees growing naturally across 36 sites in north-western Russia.Fluctuating asymmetry was the only trait that did not vary among sites with differing levels of environmental stress.Leaf/needle size and shoot length occasionally changed along stress gradients,but the magnitude and direction of these changes differed by gradient type and species,resulting in no significant overall stress effect for either trait.In contrast,photosynthetic efficiency,vertical increment and needle longevity consistently decreased from low-stress to high-stress sites.The overall effect was significant for each of these three traits despite the magnitudes of these decreases differed depending on the gradient type and location,species,study year and individual tree.Replication at spatial,temporal and taxonomic levels ensured the robustness and reliability of our results that photosynthetic efficiency,vertical growth and needle longevity reliably captured a general stress syndrome and may serve as stress indicators in forest species.
基金supported by the National Key R&D Program of China(2022YFF1001800)the National Natural Science Foundation of China(32088102)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0630103).
文摘Plantshave evolvedvariousmechanismsto interact withmicroorganisms,which help them acquire nutrients from the soil and enhance their tolerance to environmental stresses.One of the most widespread mutualistic interactions is arbuscular mycorrhizal(AM)symbiosis,which is formed by 80%-90%of terrestrial plants in association with AM fungi.In AM symbiosis,plants acquire mineral nutrients from the fungi in exchange for fatty acids and sugars that are produced during photosynthesis(Jiang et al.,2017).
基金co-supported by National Natural Science Foundation of China (No. 51175502)National Defence Pre-research Foundation (No. 9140A17060411KG01)
文摘Associating environmental stresses （ESs） with built-in test （BIT） output is an important means to help diagnose intermittent faults （IFs）. Aiming at low efficiency in association of traditional time stress measurement device （TSMD）, an association model is built. Thereafter, a novel approach is given to evaluate the integrated environmental stress （IES） level. Firstly, the selection principle and approach of main environmental stresses （MESs） and key characteristic parameters （KCPs） are presented based on fault mode, mechanism, and ESs analysis （FMMEA）. Secondly, reference stress events （RSEs） are constructed by dividing IES into three stress levels according to its impact on faults; and then the association model between integrated environmental stress event （IESE） and BIT output is built. Thirdly, an interval grey association approach to evaluate IES level is proposed due to the interval number of IES value. Consequently, the association output can be obtained as well. Finally, a case study is presented to demonstrate the proposed approach. Results show the proposed model and approach are effective and feasible. This approach can be used to guide ESs measure, record, and association. It is well suited for on-line assistant diagnosis of faults, especially IFs.
基金Supported by the Project of Development and Reform Commission of Jilin Province,China
文摘Multiplex environmental factors are generally expected to have significant effects on genetic diversity of plant populations.In this study,randomly amplified polymorphic DNA（RAPD） technique was used to reveal the genetic diversity in the same species of four populations collected from Niupidujuan（Rhododendron chrysanthum） at different altitudes,an endangered species,endemic to Northeast China.Initially,twenty informative and reproducible primers were chosen for final RAPD analysis.A total of 152 clear bands were obtained,including 143 polymorphic ones.With the help of POPGENE software,the poly rate was calculated to be 94.07% and the evenness of amplified bands for every primer was 6.8.Additionally,the mean observed number of alleles was 1.7265 with an effective number of 1.3608.An examination of the gene indicated a diversity of 0.2162 with an information diversity index of 0.3313.For these data,the clustering blurred analysis was performed with the aid of NTSYS-pc software to define the Nei＇s gene diversity and the Shannon information diversity index of the four plant populations.The relationships between the genetic diversity indexes on the one hand and the geographic and climatic factors on the other hand were estimated by the Pearson correlation with SPSS 11.0 software.The results of the correlation analysis show that there were significant（P〈0.05） or highly significant（P〈0.01） correlations between each of the genetic diversity indexes and the different temperature which were mainly caused by the altitude different populations located.These data highlight the importance of native populations in shaping the spatial genetic structure in Niupidujuan.
基金The National Natural Science Foundation of China under contract Nos 40676076 and 700069a post-doctoral fellowship of Inha University and a grant from the Center of Excellence in Biodiversity Research, King Saud University
文摘In order to evaluate the relationships between temporal species succession of planktonic protists and physical-chemical parameters in semi-enclosed mariculture waters, species distributions in response to environmental stress were investigated in a shrimp-farming pond near Qingdao, China during a complete shrimp-culture cycle （May to October 2002）. A clear temporal succession in species distribution was found over the complete farming cycle. For example, before the introduction of the shrimp larvae there was low-variability of species distribution in the protist communities whereas during the stages immediately after, there was higher variability in species composition. Multiple linear/logistic regression analyses demonstrate that 12 protist taxa （e.g., Gyrodinium spirale, Teleaulax acuta, Prorocentrum spp. and Mesodinium pupula） were related to the nutrients, in particular ammonia and phosphates, alone or in combination with water temperature. These results suggest that temporal variations in species distribution of planktonic protist communities might be used in assessing water quality of semi-enclosed mariculture waters.
基金Supported by National Key R&D Program(2017YFC1701503)National Nature Science Foundation of China(81872963)。
文摘Lonicera japonica Thunb.is widely distributed in China.It has strong adaptability to the environment and can maintain normal growth and development under a variety of stress conditions.It is commonly used as a medicine with its dry flower buds or newly opened flowers,named honeysuckle,and with both economic value and ecological application value.The research progress of L.japonica Thunb.under stress conditions such as temperature,drought,light,salt,heavy metals and diseases,pests and endophytic bacteria was reviewed,and the current research situation of the physiological and biochemical response mechanism,changes of photosynthetic fluorescence and accumulation of secondary metabolites of honeysuckle under different stresses was discussed,so as to provide a reference for deep-level exploring the resistance mechanism of L.japonica Thunb.in the future and lay a theoretical foundation for the high-quality authentic ecological cultivation of L.japonica Thunb.
基金supported by the National Natural Science Foundation of China (No.31471988 and N0.31200287)。
文摘The gut microbiota has gained attention because of its importance in facilitating host survival and evolution.However,it is unclear whether gut microbial communities are determined by the host(heritable factor) or environment(environmental factor).In this study,we investigated the gut microbial communities and potential functional signatures of two sympatric species distributed along an elevation gradient,the toadheaded lizards Phrynocephalus axillaris and P.forsythii.Our results indicated that at high elevations,the gut microbial communities of P.axillaris and P.forsythii did not significantly differ,and the phylogenetic relationships of gut microbial communities contradicted their hosts.At low altitudes,the two lizards could be distinguished based on their significantly different gut microbial communities.Compared to low-altitude populations,Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis showed that at higher altitudes,energy metabolism,such as carbohydrate,lipid,and amino acids metabolism were higher in both lizards.While a larger number of pathogenic bacteria were found in the lowaltitude population of P.forsythii.This suggests that the convergence of gut microbiota of two lizards at highaltitude stem from environmental factors,as they were exposed to the same environmental stress,whereas the divergence at low-altitude stemmed from heritable factors,as they were exposed to different environmental stresses.These results provide a new perspective regarding whether heritable or environmental factors dominate the gut microbiota during exposure to environmental stress.
基金Project supported by Knowledge Innovation Funds from Chinese Academy of Sciences (Nos. KSCX2-SW-120, KZCX1-SW-01-01A3)the Key Project of Guangdong Natural Science Foundation (No. 010567), China Author for correspondence
文摘Sap flow and environmental conditions were monitored at two Eucalyptus (Eucalyptus urophylla S.T.Blake) plantations at Hetou and Jijia, located in Leizhou, Zhanjiang, Guangdong Province. It was found that daily sap flux density (SFD) of Eucalyptus was closely related to daily atmospheric vapor pressure deficit (VPD) (R2=0.76, P=0.01 at Hetou and R2=0.7021, P=0.01 at Jijia) at both sites. No significant relationship existed between daily SFD and mean daily air temperature at both sites. Daily SFD varied with wind speed Y=-17585X3+15147X2-1250.7X+2278.4 (R2=0.68; P=0.01) at Hetou and Y=-101.67X3-1.65X2-376.4X+1914.8 (R2=0.40,P=0.05) at Jijia, where Y was daily SFD,X was daily wind speed. Experimental observations yielded the following data: (1) the critical lower and upper daily VPD threshold were 0 and 2 kPa, within which daily SFD varied from 540±70 L/(m2·d) to 4739±115 L/(m2·d) at Hetou site, from 397±26 L/(m2·d) to 3414±191 L/(m2·d) at Jijia site; (2) Diurnal SFDs at Hetou site were much higher under low relative humidity (<30%) and slightly lower under high relative humidity (>%) compared with those at the Jijia site; (3) The upper and lower threshold of daily and diurnal RAD for the optimal water use of E. urophylla plantations were 18±2.7 and 2±1 MJ/(m2·d), 669 and 0 J/(cm2·h) during the observation period.
基金Supported by The Science and Technology Department of Yibin,No.2016YZY004.
文摘Clinical studies have suggested that internal and/or external aversive cues may produce a negative affective-motivational component whereby maladaptive responses(plasticity)of dural afferent neurons are initiated contributing to migraine chronification.However,pathophysiological processes and neural circuitry involved in aversion(unpleasantness)-producing migraine chronification are still evolving.An interdisciplinary team conducted this narrative review aimed at reviewing neuronal plasticity for developing migraine chronicity and its relevant neurocircuits and providing the most cutting-edge information on neuronal mechanisms involved in the processing of affective aspects of pain and the role of unpleasantness evoked by internal and/or external cues in facilitating the chronification process of migraine headache.Thus,information presented in this review promotes the understanding of the pathophysiology of chronic migraine and contribution of unpleasantness(aversion)to migraine chronification.We hope that it will bring clinicians’attention to how the maladaptive neuroplasticity of the emotion brain in the aversive environment produces a significant impact on the chronification of migraine headache,which will in turn lead to new therapeutic strategies for this type of pain.
基金supported by the National Natural Science Foundation of China (no.82072515)Guangdong Basic and Applied Basic Research Foundation (2023A1515220072,2021A1515220030)+1 种基金Shenzhen High-level Hospital Construction Fund (no.4001013)Shenzhen Science and Technology Projects (no.JCYJ20220530150615035)。
文摘Background:The biomechanical environment created by suture-button fixation Latarjet is conducive to the healing and shaping of the transplanted coracoid,but its mechanism remains unclear.The latest research has found that the absence of stem cell chemokine(CXCL12)impeded bone regeneration in Sonic Hedgehog(SHH)-deficient animals.However,whether the biomechanical environment affects SHH and CXCL12 function has not been studied.Methods:Rat fracture models were constructed to simulate stress environments under non-l oad-bearing and load-bearing conditions.The fracture healing and shaping,as well as the expression levels of SHH and CXCL12,were assessed through gross viewing,micro-computed tomography(micro-CT),and histochemical staining.Results:Under flexible fixation,the relative bone volume(BV/TV)of rats exposed to the load-bearing stress environment was significantly higher than that of rats under a non-l oad-bearing stress environment(p≤0.05).Adverse bone shaping was not observed in rats subjected to flexible fixation.The levels of SHH and CXCL12in load-bearing rats exhibited significant elevation(p≤0.05).Under a load-bearing stress environment,no significant difference was observed in the BV/TV between the flexible fixation group and the rigid fixation group(p≥0.05),but there was excessive hyperplasia of the fracture callus in the rigid fixation group.The levels of SHH and CXCL12 in rats subjected to rigid fixation were significantly elevated(p≤0.05).Conclusions:Flexible fixation and load-bearing stress environment may contribute to bone healing and shaping by influencing the levels of SHH and CXCL12,suggested that this mechanism may be relevant to the healing and shaping of the transplanted coracoid after suture-button fixation Latarjet.
文摘[Objective] The study aimed to analyze the eco-environrnental stress trend of Inner Mongolia using ecological stress index method. [Methed] On the basis of the improved ecological stress index （ESI） analysis method, the eco-environmental stress trend of Inner Mongolia from 1996 to 2009 was analyzed, as well as the changes of eco-environmental stress in major industrial cities of Inner Mongolia in 2008. [ Result] With the economic development of Inner Mongolia from 1996 to 2009, the U-shape change could be found in the eco-environmental stress, showing an upward trend on the whole, especially since 2003, and there was a sharp raise in the environmental pollution index. In addition, the eco-enviren- mental stress lessened in most major cities of Inner Mongolian in 2008, but it was in a polarization state, that is, Baotou, Wuhai and Hohhot biased resource and energy consumption, while Ordos and Chifeng biased environmental pollution. [ Conclusion] The research could provide scientific ref- erences for the protection of ecological environment and the adjustment of industrial structure in Inner Mongolia.
文摘In order to evaluate the influence of stressed environments on hepatopancreatic cells of fre- shwater prawns, Macrobachium borellii Nobili, 1896 and Palaemonetes argentinus Nobili 1901, (Crustacea, Decapoda, Palaemonidae) were collected at three different aquatic environments with different relationship to urban development in Argentina. Furthermore the effects of several cypermethryn concentration on hepa- topancreatic cell of M. borellii and P. argentinus were evaluated in a laboratory assays. The “N°1” lake (Santa Fe Argentina) which is more affected by the anthropogenic pressure and “Don Felipe” lake which is still not strongly by human activities were the studied sites from the floodplain of Paranáriver. While Alejandra lake was the intermedia effects sites. Different damaged ultra-structures were found in F- and R-cells of prawns in the stressed lake. The predominant features were: disrupted the microvillous border, swelled mitochondria, reduction of endoplasmic reticulum, dyctiosomes, glycoproteins, desna-turalization of vacuole membrane and premature autolysis. Moreover the F-cell number was higher in the environment near to city than in the others sites. Similar effects were observed in the cypermethryn assays. The observations clearly indicate that the ultrastructure of midgut gland in the both palaemonids varies depending on the site from which animals are collected and the biocid presence. So, in this case it can be stated that the hepatopancreas histology of fre- shwater prawns is a good tool to monitor the impact of a stressed environment upon freshwater prawns.
文摘Antibiotic resistant Escherichia coli strains are becoming more common recently. OmpA is a very important antigen protein of E. coli, which consists of two separate domains, N-terminal and C-terminal domain. The N-terminal domain contains eight β- barrel regions that plays important roles in the multifaceted functions of OmpA. In the present study, we cloned a mutant OmpA gene from a multi-antibiotic resistant E. coli strain. Sequence analysis indicated that the N-terminal DNA sequence of the mutant OmpA shared 81.05% homology with the modeled OmpA from E. coli K12 and the N-terminal amino acid sequence of the mutant OmpA was 81.22% identical to that of the E. coli K12 OmpA. Moreover, several amino acids located in the β-barrel region were mutated. The mutant OmpA was expressed in BL21 suggested by SDS-PAGE. Resistance to environmental stress assay indicated that the N-terminus mutant OmpA still possessed excellent activities in pH, temperature and osmotic pressure resistance. Our pre- sent study may supply insights into better and deeper understand the relationships between OmpA N-terminal regions and its functions in environmental stress conditions and the mechanisms on antibiotic resistance of E. coli.
基金supported by the Ministry of Education and Science of Armenia (10-3/9) (Basic support)
文摘Pollution by various heavy metals as environmental stress factors might affect bacteria. It was established that iron（Fe（Ⅲ））, manganese（Mn（Ⅱ）） and copper（Cu（Ⅱ）） ion combinations caused effects on Enterococcus hirae that differed from the sum of the effects when the metals were added separately. It was shown that the Cu2＋–Fe3＋combination decreased the growth and ATPase activity of membrane vesicles of wild-type E. hirae ATCC9790 and atp D mutant（with defective FoF1-ATPase） MS116. Addition of Mn2＋–Fe3＋combinations within the same concentration range had no effects on growth compared to control（without heavy metals）. ATPase activity was increased in the presence of Mn2＋–Fe3＋, while together with0.2 mmol/L N,N′-dicyclohexylcarbodiimide（DCCD）, ATPase activity was decreased compared to control（when only 0.2 mmol/L DCCD was present）. These results indicate that heavy metals ion combinations probably affect the FOF1-ATPase, leading to conformational changes. Moreover the action may be direct or be mediated by environment redox potential.The effects observed when Fe3＋was added separately disappeared in both cases, which might be a result of competing processes between Fe3＋and other heavy metals. These findings are novel and improve the understanding of heavy metals ions effects on bacteria,and could be applied for regulation of stress response patterns in the environment.
基金National Natural Science Foundation of China,No.41971164, No.42071148Strategic Priority Research Program of the Chinese Academy of Sciences,Grant No.XDA23020101。
文摘Environmental stress is used as an indicator of the overall pressure on regional environmental systems caused by the output of various pollutants as a result of human activities. Based on the pollutant emissions and socioeconomic databases of the counties in Beijing–Tianjin–Hebei region, this paper comprehensively calculates the environmental stress index(ESI) for the urban agglomeration using the entropy weight method(EWM) at the county scale and analyzes the spatiotemporal patterns and the differences among the four types of major functional zones(MFZ) for the period 2012–2016. In addition, the socioeconomic driving forces of environmental stress are quantitatively estimated using the geographically weighted regression(GWR) method based on the STIRPAT model framework. The results show that:(1) The level of environmental stress in the Beijing–Tianjin–Hebei region was significantly alleviated during that time period, with a decrease in ESI of 54.68% by 2016. This decrease was most significant in Beijing, Tangshan, Tianjin, Shijiazhuang, and other central urban areas, as well as the Binhai New Area. The level of environmental stress in counties decreased gradually from the central urban areas to the suburban areas, and the high-level stress counties were eliminated by 2016.(2) The spatial spillover effect of environmental stress increased further at the county scale from 2012 to 2016, and spatial locking and path dependence emerged in the cities of Tangshan and Tianjin.(3) Urbanized zones(development-optimized and development-prioritized zones) were the major areas bearing environmental pollution in the Beijing–Tianjin–Hebei region in that time period. The ESI accounted for 65.98% of the whole region, where there was a need to focus on the prevention and control of environmental pollution.(4) The driving factors of environmental stress at the county scale included population size and the level of economic development. In addition, the technical capacity of environmental waste disposal, the intensity of agricultural production input, the intensity of territorial development, and the level of urbanization also had a certain degree of influence.(5) There was spatial heterogeneity in the effects of the various driving factors on the level of environmental stress. Thus, it was necessary to adopt differentiated environmental governance and reduction countermeasures in respect of emission sources, according to the intensity and spatiotemporal differences in the driving forces in order to improve the accuracy and adaptability of environmental collaborative control in the Beijing–Tianjin–Hebei region.
文摘Fluorescence correlation spectroscopy （FCS） without objective image magnification （without using con-focal microscope） was applied to observe the variation in cell size of Escherichia coli （E. coli） induced by the anti-cancer agent MitomycinC （MMC）. In the system without image magnification followed in this study, the suspension of E. coli cells was stirred, and the difference in movement due to the different cell sizes induced by the compulsive solution flow was detected. The addition of 0.1-0.4 pg/L of MMC elongated the E. coli cell length from about 3.6 to 7.8μm. The flow cell （i.d. = about 1 mm） also produced a size-dependent correlation curve, The present system is not based on single molecular FCS but is inexpensive and effective at observing the variation in cell size induced by environmental changes.
文摘The environment shear stress of Tangshan main earthquake and 38 great aftershocks have been calculated by the acceleration data of Tangshan earthquake sequence. The environment shear stress for 52 smaller aftershocks from July of 1982 to July of 1984 have also been calculated by use of the digital data of the Sino-American cooperation recorded by the instrumental arrays in Tangshan. The results represent that the environment shear stress τ0 values have a weak dependence on the seismic moment, only the small and moderate earthquakes will be able to occur in the region with smaller τ0 value and the large earthquakes are only in the region with greater τ0 value. The peak acceleration, velocity and displacement will be larger for the earthquakes occurred in the region with greater τ0 value, Therefore, the measurement of environment shear stress τ0 value for the significant region will play an important role in earthquske prediction and engineering shock-proof. The environment shear stress values for the great aftershocks occurred in the two ends of the main fault are often higher than that for the main shock. This case may represent the stress concentration in the two ends of the fault. This phenomenon provides the references for the place where the great aftershock will occur.
文摘Environmental stress model is proposed as an effective tool to the analysis and evaluation of navigational safety in ports and waterways. Marine traffic simulations are carried out in a virtual port area with various arrangements and conditions. Calculations of stress values and traffic volume criteria are illustrated. The simulation results provide a valuable hint for safety management of vessel traffic. The model provides quantitative information and helps administrators in decision making to achieve desired safety level and improve the efficiency of vessel traffic in ports and waterways.
