The capability of neurons to discriminate between intensity of external stimulus is measured by its dynamic range.A larger dynamic range indicates a greater probability of neuronal survival.In this study,the potential...The capability of neurons to discriminate between intensity of external stimulus is measured by its dynamic range.A larger dynamic range indicates a greater probability of neuronal survival.In this study,the potential roles of adaptation mechanisms（ion currents） in modulating neuronal dynamic range were numerically investigated.Based on the adaptive exponential integrate-and-fire model,which includes two different adaptation mechanisms,i.e.subthreshold and suprathreshold（spike-triggered） adaptation,our results reveal that the two adaptation mechanisms exhibit rather different roles in regulating neuronal dynamic range.Specifically,subthreshold adaptation acts as a negative factor that observably decreases the neuronal dynamic range,while suprathreshold adaptation has little influence on the neuronal dynamic range.Moreover,when stochastic noise was introduced into the adaptation mechanisms,the dynamic range was apparently enhanced,regardless of what state the neuron was in,e.g.adaptive or non-adaptive.Our model results suggested that the neuronal dynamic range can be differentially modulated by different adaptation mechanisms.Additionally,noise was a non-ignorable factor,which could effectively modulate the neuronal dynamic range.展开更多
Background:Historical forests(circa 1799 to 1846)of Indiana were predominantly composed of American beech(25%of all trees)and upland oaks(27%of all trees).I compared historical forest composition,using studies of smal...Background:Historical forests(circa 1799 to 1846)of Indiana were predominantly composed of American beech(25%of all trees)and upland oaks(27%of all trees).I compared historical forest composition,using studies of smaller areas to approximate composition for uncommon species or genera(<4.5%of all trees)and forest types,to current forest composition and forest types in Indiana.I also compiled published historical density estimates from small studies and estimated current density for the state.Results:Current forests are diverse with an even composition of many eastern broadleaf species.In addition to upland oaks,which decreased to 13%of all trees,only sugar maple currently comprises greater than 10%of all trees.Other increasing species were yellow-poplar,red maple,black cherry,and eastern redcedar.Eastern redcedar increased from no presence to one of the most abundant ten species(≥3.5%of composition),similarly to the pine genus,becoming more common currently than American beech.Beech or oak or beech-oak forest types(≥24%of all trees)became eastern broadleaf forests,with no dominant species,and black cherry,red maple,and eastern redcedar forest types now occurred.Estimates of historical oak or beech forests ranged from 28 trees per hectare to 175 trees per hectare,which probably represent savannas and woodlands.Current mean density of Indiana forests is 385 trees per hectare,ranging from 180 trees per hectare to 450 trees per hectare.These forests likely contain dense layers of woody vegetation,filling the midstory and replacing herbaceous vegetation in the ground layer.Conclusion:Historically dominant beech and oak forests in the eastern United States have transitioned to an alternative state of closed eastern broadleaf forests due to uncontrolled establishment of many tree species.展开更多
Objective:To observe the clinical efficacy of filiform fire-needling plus continuous passive motion(CPM)therapy for frozen shoulder.Methods:A total of 72 patients were randomized into an observation group and a contro...Objective:To observe the clinical efficacy of filiform fire-needling plus continuous passive motion(CPM)therapy for frozen shoulder.Methods:A total of 72 patients were randomized into an observation group and a control group by the random number table method,with 36 cases in each group.Patients in the control group received celecoxib capsule plus CPM,while those in the observation group received filiform fire-needling plus CPM.The whole course of treatment lasted for 2 weeks in both groups.The visual analog scale(VAS),Constant-Murley score(CMS)and range of motion of shoulder joint were measured for therapeutic efficacy evaluation.Results:The total effective rate was 91.7%in the observation group,higher than 72.2%in the control group,and the between-group comparison showed statistical significance(P<0.05).After treatment,the VAS scores in the two groups dropped significantly,the CMS as well as the range of motion including abduction,forward flexion and extension were all increased significantly,and the intra-group comparisons showed statistical significance(all P<0.05).The betweengroup comparisons showed the improvements in these items in the observation group were more significant than those in the control group(all P<0.05).Conclusion:Filiform fire-needling plus CPM can produce more significant efficacy than celecoxib capsule plus CPM for frozen shoulder;it can alleviate pain,improve shoulder function and restore joint range of motion in such patients.展开更多
Free and open access to the Landsat archive has enabled the detection and delineation of an unprecedented number of fire events across the globe.Despite the availability and potential of these data,few studies have an...Free and open access to the Landsat archive has enabled the detection and delineation of an unprecedented number of fire events across the globe.Despite the availability and potential of these data,few studies have analysed residual vegetation patterns and/or partial mortality of fire across the Canadian boreal forest,and those available,are either incomplete or inaccurate.Further,they all differ in the methods and spatial language,which makes it difficult for managers to interpret fire patterns over large areas.There is an urgent need for methods to help unify fire pattern observations across the Canadian boreal forest.This study explores the capacity of the Landsat data archive when coupled with a recently developed fire mapping approach and a robust spatial language to characterize and compare tree mortality patterns across the boreal plains ecozone,Canada.With 507 fires 2.5 Mha mapped,this study represents the most comprehensive analysis of mortality patterns for study area.Summaries from this demonstration generated an accurate characterization of the fire patterns the various ecoregions based on seven key fire metrics.The comparison between ecoregions revealed differences in the amount of residual vegetation,which in turn suggested various climate,topography and/or vegetation ecosystem drivers.展开更多
基金supported by a grant from Beijing Municipal Commission of Science and Technology of China,No.Z151100000915070
文摘The capability of neurons to discriminate between intensity of external stimulus is measured by its dynamic range.A larger dynamic range indicates a greater probability of neuronal survival.In this study,the potential roles of adaptation mechanisms（ion currents） in modulating neuronal dynamic range were numerically investigated.Based on the adaptive exponential integrate-and-fire model,which includes two different adaptation mechanisms,i.e.subthreshold and suprathreshold（spike-triggered） adaptation,our results reveal that the two adaptation mechanisms exhibit rather different roles in regulating neuronal dynamic range.Specifically,subthreshold adaptation acts as a negative factor that observably decreases the neuronal dynamic range,while suprathreshold adaptation has little influence on the neuronal dynamic range.Moreover,when stochastic noise was introduced into the adaptation mechanisms,the dynamic range was apparently enhanced,regardless of what state the neuron was in,e.g.adaptive or non-adaptive.Our model results suggested that the neuronal dynamic range can be differentially modulated by different adaptation mechanisms.Additionally,noise was a non-ignorable factor,which could effectively modulate the neuronal dynamic range.
文摘Background:Historical forests(circa 1799 to 1846)of Indiana were predominantly composed of American beech(25%of all trees)and upland oaks(27%of all trees).I compared historical forest composition,using studies of smaller areas to approximate composition for uncommon species or genera(<4.5%of all trees)and forest types,to current forest composition and forest types in Indiana.I also compiled published historical density estimates from small studies and estimated current density for the state.Results:Current forests are diverse with an even composition of many eastern broadleaf species.In addition to upland oaks,which decreased to 13%of all trees,only sugar maple currently comprises greater than 10%of all trees.Other increasing species were yellow-poplar,red maple,black cherry,and eastern redcedar.Eastern redcedar increased from no presence to one of the most abundant ten species(≥3.5%of composition),similarly to the pine genus,becoming more common currently than American beech.Beech or oak or beech-oak forest types(≥24%of all trees)became eastern broadleaf forests,with no dominant species,and black cherry,red maple,and eastern redcedar forest types now occurred.Estimates of historical oak or beech forests ranged from 28 trees per hectare to 175 trees per hectare,which probably represent savannas and woodlands.Current mean density of Indiana forests is 385 trees per hectare,ranging from 180 trees per hectare to 450 trees per hectare.These forests likely contain dense layers of woody vegetation,filling the midstory and replacing herbaceous vegetation in the ground layer.Conclusion:Historically dominant beech and oak forests in the eastern United States have transitioned to an alternative state of closed eastern broadleaf forests due to uncontrolled establishment of many tree species.
文摘Objective:To observe the clinical efficacy of filiform fire-needling plus continuous passive motion(CPM)therapy for frozen shoulder.Methods:A total of 72 patients were randomized into an observation group and a control group by the random number table method,with 36 cases in each group.Patients in the control group received celecoxib capsule plus CPM,while those in the observation group received filiform fire-needling plus CPM.The whole course of treatment lasted for 2 weeks in both groups.The visual analog scale(VAS),Constant-Murley score(CMS)and range of motion of shoulder joint were measured for therapeutic efficacy evaluation.Results:The total effective rate was 91.7%in the observation group,higher than 72.2%in the control group,and the between-group comparison showed statistical significance(P<0.05).After treatment,the VAS scores in the two groups dropped significantly,the CMS as well as the range of motion including abduction,forward flexion and extension were all increased significantly,and the intra-group comparisons showed statistical significance(all P<0.05).The betweengroup comparisons showed the improvements in these items in the observation group were more significant than those in the control group(all P<0.05).Conclusion:Filiform fire-needling plus CPM can produce more significant efficacy than celecoxib capsule plus CPM for frozen shoulder;it can alleviate pain,improve shoulder function and restore joint range of motion in such patients.
基金Saskatchewan Environment,fRI Research Healthy Landscapes Program,the government of the Northwest Territories,Bandaloop Landscape-Ecosystem Services,and an NSERC Discovery and Engage grant to Coops(RGPIN 311926-13 and EGP 503226-16).
文摘Free and open access to the Landsat archive has enabled the detection and delineation of an unprecedented number of fire events across the globe.Despite the availability and potential of these data,few studies have analysed residual vegetation patterns and/or partial mortality of fire across the Canadian boreal forest,and those available,are either incomplete or inaccurate.Further,they all differ in the methods and spatial language,which makes it difficult for managers to interpret fire patterns over large areas.There is an urgent need for methods to help unify fire pattern observations across the Canadian boreal forest.This study explores the capacity of the Landsat data archive when coupled with a recently developed fire mapping approach and a robust spatial language to characterize and compare tree mortality patterns across the boreal plains ecozone,Canada.With 507 fires 2.5 Mha mapped,this study represents the most comprehensive analysis of mortality patterns for study area.Summaries from this demonstration generated an accurate characterization of the fire patterns the various ecoregions based on seven key fire metrics.The comparison between ecoregions revealed differences in the amount of residual vegetation,which in turn suggested various climate,topography and/or vegetation ecosystem drivers.
