Aims In estuarine salt-marshes,nitrate supply and soil salinity,which are known as two main environmental drivers,simultaneously affect the interspecific interactions between plant species.However,to date,their intera...Aims In estuarine salt-marshes,nitrate supply and soil salinity,which are known as two main environmental drivers,simultaneously affect the interspecific interactions between plant species.However,to date,their interactive effects on interspecific interactions have not been closely examined for salt-marsh plant species.Methods Juvenile plants of Suaeda salsa L.(Chenopodiaceae)and Scirpus planiculmis Fr.(Cyperaceae)were grown in rinsed river sand to conduct a greenhouse experiment with three treatment categories:interspecific interaction(mixed culture or monoculture),three salinity levels(1,50 and 100 mmol L^(-1))and three nitrate levels(0.5,5 and 10 mmol L^(-1)).First,height and biomass of all plants were measured.Then,the growth data,relative interaction index and competitive important index of the two species were analyzed.Important Findings The interspecific interactions between S.salsa and S.planiculmis were facilitation across the salinity gradients.The promotion of S.salsa growth with high nitrate supply did not enhance the facilitative effect of the species,especially at low salinity.However,high nitrate supply significantly shifted the interspecific interactions of S.planiculmis from facilitation to competition at high salinity.Our results suggest that excessive nitrate application changes the prediction of the stress-gradient hypothesis along a salinity gradient,leading to collapse of the two species coexistence in the salt-marshes.These findings make a contribution to the understanding of how S.salsa and S.planiculmis,as well as salt-marsh communities,respond to the human modification of estuarine nutritional levels.展开更多
Revise the abstract as follows:This work aims to investigate numerically the influence of the buoyancy ratio and the Dufour parameter on thermosolutal convection in a square Salt Gradient Solar Pond(SGSP).The absorpti...Revise the abstract as follows:This work aims to investigate numerically the influence of the buoyancy ratio and the Dufour parameter on thermosolutal convection in a square Salt Gradient Solar Pond(SGSP).The absorption of solar radiation by the saline water,the heat losses and the wind effects via the SGSP free surface are considered.The mathematical model is based on the Navier-Stokes equations used in synergy with the thermal energy equation.These equations are solved using the finite volume method and the Gauss algorithm.Velocity-pressure coupling is implemented through the SIMPLE algorithm.Simulations of the SGSP are performed for three values of buoyancy ratio(N=1,2 and 10),three values of Dufour parameter(Df?0,0.2 and 0.8)and some sample meteorological data(Tangier,Morocco).Results show that the highest dimensionless temperature of the storage zone is found for N=10.In the same zone and for the same value of N,the dimensionless salt concentration decreases very slightly versus time(unlike for N=1 or 2).Moreover,increasing Df from 0 to 0.8 causes a decrease in the dimensionless temperature of the SGSP storage zone and this decrease is more pronounced for N=1 and N=2.展开更多
Conventional solid-state nanopore measurements sense all translocating entities,necessitating meticulous analysis to differentiate target biomolecules.To address this,we have established a selective assay with the pla...Conventional solid-state nanopore measurements sense all translocating entities,necessitating meticulous analysis to differentiate target biomolecules.To address this,we have established a selective assay with the platform that has shown utility in quantifying several nucleic acid biomarkers.However,limited detection efficiency and intrinsic noise have so far limited assay resolution to 10 nM.Improvements in this value require manipulation of translocation dynamics.Here,we report the effects of NaCl conditions on assay performance.We first investigate symmetric conditions,finding sensitivity increases with salt concentration but selectivity is maximized at 1.0 M NaCl.We then probe asymmetric conditions,showing a remarkable impact on assay sensitivity and selectivity when measurement buffer NaCl concentration in the reservoir with the translocating molecules is low and the opposite reservoir is increased.Using optimum conditions,we demonstrate detection of target biomolecules down to a concentration of 100 pM which is an improvement of 2 orders of magnitude over past results.展开更多
While notable progress has been made in recent years both experimentally and theoretically in understanding the highly complex dynamics of polymer capture and transport through nanopores,there remains significant disa...While notable progress has been made in recent years both experimentally and theoretically in understanding the highly complex dynamics of polymer capture and transport through nanopores,there remains significant disagreement between experimental observation and theoretical prediction that needs to be resolved.Asymmetric salt concentrations,where the concentrations of ions on each side of the membrane are different,can be used to enhance capture rates and prolong translocation times of electrophoretically driven polymers translocating through a nanopore from the low salt concentration reservoir,which are both attractive features for single-molecule analysis.However,since asymmetric salt concentrations affect the electrophoretic pull inside and outside the pore differently,it also offers a useful control parameter to elucidate the otherwise inseparable physics of the capture and translocation process.In this work,we attempt to paint a complete picture of the dynamics of polymer capture and translocation in both symmetric and asymmetric salt concentration conditions by reporting the dependence of multiple translocation metrics on voltage,polymer length,and salt concentration gradient.Using asymmetric salt concentration conditions,we experimentally observe the predictions of tension propagation theory,and infer the significant impact of the electric field outside the pore in capturing polymers and in altering polymer conformations prior to translocation.展开更多
In this paper,the behavior of a salt-gradient solar pond with the square cross-section has been studied experimentally and numerically.A small-scale solar pond were designed and built to provide quantitative data.A tw...In this paper,the behavior of a salt-gradient solar pond with the square cross-section has been studied experimentally and numerically.A small-scale solar pond were designed and built to provide quantitative data.A two-dimensional,transient heat and mass transfer model has been solved numerically by using finite-control-volume method.In this study,all the thermo-physical properties are variable as the function of temperature and salt concentration.Numerical results as obtained for the experimental pond have been satisfactorily compared and validated against measured data.Furthermore,the wall shading effect has been elaborated to improve the agreement between two sets of results.The temperature of the storage zone is predicted well by the model.It also can be observed that the initial concentration profile is preserved with time.The stability of the pond in time has been investigated in order to distinguish the critical zones.Finally,the application of an energy analysis gives an efficiency of about 12%for the pond.展开更多
Xinjiang is the province with the largest saline-alkali land in China.The growth of halophytes will be stressed when their salt content reaches the threshold.In this study,the pot experiments were conducted and Suaeda...Xinjiang is the province with the largest saline-alkali land in China.The growth of halophytes will be stressed when their salt content reaches the threshold.In this study,the pot experiments were conducted and Suaeda salsa,a typical halophyte,was selected as the object to explore the relationship between growth characteristics and salt content under different soil salinity gradients.Salinity gradients were set according to the maximum soil salinity in the current years of Ebinur Lake Wetland National Nature Reserve(ELWNNR).They were classified using the following threshold values:≤2 g/kg(Control Group),10 g/kg,20 g/kg,30 g/kg,and 40 g/kg.The original spectrum,trilateral position and growth characteristics were used as indexes for analysis.With the increase of soil salt content,the red edge shift occurs first,followed by the blue edge shift.The position of yellow edge,green peak and blue edge were not sensitive to the change of soil salinity.This indicates that the red edge is the best indicator for evaluating plant growth.Compared with the Control Group,when the salt content is less than 10 g/kg,the growth status of plant seems not significantly affected.However,plant growth begins to be stressed when the salt content increases to 20 g/kg,which is a turning point for plant health.The increase of soil salt content can inhibit chlorophyll synthesis and plant growth.Plants begin to die when the salt content reaches 40 g/kg.Therefore,40 g/kg could be regarded as the critical point of salt content which inhibits plant growth.The study also shows that the relationship between plant-height change rate and soil salt content is the most significant,indicating that the plant-height change rate is significantly impacted by soil salt content.展开更多
基金supported by the National Key R&D Program of China(2017YFC0506200).
文摘Aims In estuarine salt-marshes,nitrate supply and soil salinity,which are known as two main environmental drivers,simultaneously affect the interspecific interactions between plant species.However,to date,their interactive effects on interspecific interactions have not been closely examined for salt-marsh plant species.Methods Juvenile plants of Suaeda salsa L.(Chenopodiaceae)and Scirpus planiculmis Fr.(Cyperaceae)were grown in rinsed river sand to conduct a greenhouse experiment with three treatment categories:interspecific interaction(mixed culture or monoculture),three salinity levels(1,50 and 100 mmol L^(-1))and three nitrate levels(0.5,5 and 10 mmol L^(-1)).First,height and biomass of all plants were measured.Then,the growth data,relative interaction index and competitive important index of the two species were analyzed.Important Findings The interspecific interactions between S.salsa and S.planiculmis were facilitation across the salinity gradients.The promotion of S.salsa growth with high nitrate supply did not enhance the facilitative effect of the species,especially at low salinity.However,high nitrate supply significantly shifted the interspecific interactions of S.planiculmis from facilitation to competition at high salinity.Our results suggest that excessive nitrate application changes the prediction of the stress-gradient hypothesis along a salinity gradient,leading to collapse of the two species coexistence in the salt-marshes.These findings make a contribution to the understanding of how S.salsa and S.planiculmis,as well as salt-marsh communities,respond to the human modification of estuarine nutritional levels.
文摘Revise the abstract as follows:This work aims to investigate numerically the influence of the buoyancy ratio and the Dufour parameter on thermosolutal convection in a square Salt Gradient Solar Pond(SGSP).The absorption of solar radiation by the saline water,the heat losses and the wind effects via the SGSP free surface are considered.The mathematical model is based on the Navier-Stokes equations used in synergy with the thermal energy equation.These equations are solved using the finite volume method and the Gauss algorithm.Velocity-pressure coupling is implemented through the SIMPLE algorithm.Simulations of the SGSP are performed for three values of buoyancy ratio(N=1,2 and 10),three values of Dufour parameter(Df?0,0.2 and 0.8)and some sample meteorological data(Tangier,Morocco).Results show that the highest dimensionless temperature of the storage zone is found for N=10.In the same zone and for the same value of N,the dimensionless salt concentration decreases very slightly versus time(unlike for N=1 or 2).Moreover,increasing Df from 0 to 0.8 causes a decrease in the dimensionless temperature of the SGSP storage zone and this decrease is more pronounced for N=1 and N=2.
基金supported by NIH awards(Nos.R21CA193067,R33CA246448,and P41EB020594)。
文摘Conventional solid-state nanopore measurements sense all translocating entities,necessitating meticulous analysis to differentiate target biomolecules.To address this,we have established a selective assay with the platform that has shown utility in quantifying several nucleic acid biomarkers.However,limited detection efficiency and intrinsic noise have so far limited assay resolution to 10 nM.Improvements in this value require manipulation of translocation dynamics.Here,we report the effects of NaCl conditions on assay performance.We first investigate symmetric conditions,finding sensitivity increases with salt concentration but selectivity is maximized at 1.0 M NaCl.We then probe asymmetric conditions,showing a remarkable impact on assay sensitivity and selectivity when measurement buffer NaCl concentration in the reservoir with the translocating molecules is low and the opposite reservoir is increased.Using optimum conditions,we demonstrate detection of target biomolecules down to a concentration of 100 pM which is an improvement of 2 orders of magnitude over past results.
基金the support of the Natural Sciences and Engineering Research Council of Canada(NSERC),through funding from No.CRDPJ 530554-18.
文摘While notable progress has been made in recent years both experimentally and theoretically in understanding the highly complex dynamics of polymer capture and transport through nanopores,there remains significant disagreement between experimental observation and theoretical prediction that needs to be resolved.Asymmetric salt concentrations,where the concentrations of ions on each side of the membrane are different,can be used to enhance capture rates and prolong translocation times of electrophoretically driven polymers translocating through a nanopore from the low salt concentration reservoir,which are both attractive features for single-molecule analysis.However,since asymmetric salt concentrations affect the electrophoretic pull inside and outside the pore differently,it also offers a useful control parameter to elucidate the otherwise inseparable physics of the capture and translocation process.In this work,we attempt to paint a complete picture of the dynamics of polymer capture and translocation in both symmetric and asymmetric salt concentration conditions by reporting the dependence of multiple translocation metrics on voltage,polymer length,and salt concentration gradient.Using asymmetric salt concentration conditions,we experimentally observe the predictions of tension propagation theory,and infer the significant impact of the electric field outside the pore in capturing polymers and in altering polymer conformations prior to translocation.
文摘In this paper,the behavior of a salt-gradient solar pond with the square cross-section has been studied experimentally and numerically.A small-scale solar pond were designed and built to provide quantitative data.A two-dimensional,transient heat and mass transfer model has been solved numerically by using finite-control-volume method.In this study,all the thermo-physical properties are variable as the function of temperature and salt concentration.Numerical results as obtained for the experimental pond have been satisfactorily compared and validated against measured data.Furthermore,the wall shading effect has been elaborated to improve the agreement between two sets of results.The temperature of the storage zone is predicted well by the model.It also can be observed that the initial concentration profile is preserved with time.The stability of the pond in time has been investigated in order to distinguish the critical zones.Finally,the application of an energy analysis gives an efficiency of about 12%for the pond.
基金support provided by the National Natural Science Foundation of China(Grant No.U1503302,U1603241)the Tianshan Talent Project(Phase III)of the Xinjiang Uygur Autonomous Region and the Local People’s Government of the Xinjiang Uygur Autonomous Region in China sent abroad to study abroad as a complete set of projects(Grant No.L06).
文摘Xinjiang is the province with the largest saline-alkali land in China.The growth of halophytes will be stressed when their salt content reaches the threshold.In this study,the pot experiments were conducted and Suaeda salsa,a typical halophyte,was selected as the object to explore the relationship between growth characteristics and salt content under different soil salinity gradients.Salinity gradients were set according to the maximum soil salinity in the current years of Ebinur Lake Wetland National Nature Reserve(ELWNNR).They were classified using the following threshold values:≤2 g/kg(Control Group),10 g/kg,20 g/kg,30 g/kg,and 40 g/kg.The original spectrum,trilateral position and growth characteristics were used as indexes for analysis.With the increase of soil salt content,the red edge shift occurs first,followed by the blue edge shift.The position of yellow edge,green peak and blue edge were not sensitive to the change of soil salinity.This indicates that the red edge is the best indicator for evaluating plant growth.Compared with the Control Group,when the salt content is less than 10 g/kg,the growth status of plant seems not significantly affected.However,plant growth begins to be stressed when the salt content increases to 20 g/kg,which is a turning point for plant health.The increase of soil salt content can inhibit chlorophyll synthesis and plant growth.Plants begin to die when the salt content reaches 40 g/kg.Therefore,40 g/kg could be regarded as the critical point of salt content which inhibits plant growth.The study also shows that the relationship between plant-height change rate and soil salt content is the most significant,indicating that the plant-height change rate is significantly impacted by soil salt content.
