The stability of a set of spatially constant plane wave solutions to a pair of damped coupled nonlinear Schrödinger evolution equations is considered. The equations could model physical phenomena arising in fluid...The stability of a set of spatially constant plane wave solutions to a pair of damped coupled nonlinear Schrödinger evolution equations is considered. The equations could model physical phenomena arising in fluid dynamics, fibre optics or electron plasmas. The main result is that any small perturbation to the solution remains small for all time. Here small is interpreted as being both in the supremum sense and the square integrable sense.展开更多
The cosmopolitan calcifying alga Emiliania huxleyi is one of the most abundant bloom forming coccolithophore species in the oceans and plays an important role in global biogeochemical cycling. Coccolithoviruses are a ...The cosmopolitan calcifying alga Emiliania huxleyi is one of the most abundant bloom forming coccolithophore species in the oceans and plays an important role in global biogeochemical cycling. Coccolithoviruses are a major cause of coccolithophore bloom termination and have been studied in laboratory, mesocosm and open ocean studies. However, little is known about the dynamic interactions between the host and its viruses, and less is known about the natural diversity and role of functionally important genes within natural coccolithovirus communities. Here, we investigate the temporal and spatial distribution of coccolithoviruses by the use of molecular fingerprinting techniques PCR, DGGE and genomie sequencing. The natural biodiversity of the virus genes encoding the major capsid protein （MCP） and serine palmitoyltransferase （SPT） were analysed in samples obtained from the Atlantic Meridional Transect （AMT）, the North Sea and the L4 site in the Westem Channel Observatory. We discovered nine new coccolithovirus genotypes across the AMT and L4 site, with the majority of MCP sequences observed at the deep chlorophyll maximum layer of the sampled sites on the transect. We also found four new SPT gene variations in the North Sea and at L4. Their translated fragments and the full protein sequence of SPT from laboratory strains EhV-86 and EhV-99B 1 were modelled and revealed that the theoretical fold differs among strains. Variation identified in the structural distance between the two domains of the SPT protein may have an impact on the catalytic capabilities of its active site. In summary, the combined use of ＇standard＇ markers （i.e. MCP）, in combination with metabolically relevant markers （i.e. SPT） are useful in the study of the phylogeny and functional biodiversity of coccolithoviruses, and can provide an interesting intracellular insight into the evolution of these viruses and their ability to infect and replicate within their algal hosts.展开更多
Background Social relationships are associated with mortality and chronic conditions.However,little is known about the effects of social relationship satisfaction on multiple chronic conditions(multimorbidity).Aims To...Background Social relationships are associated with mortality and chronic conditions.However,little is known about the effects of social relationship satisfaction on multiple chronic conditions(multimorbidity).Aims To examine whether social relationship satisfaction is associated with the accumulation of multimorbidity.Methods Data from 7694 Australian women who were free from 11 chronic conditions at 45–50 years of age in 1996 were analysed.Five types of social relationship satisfaction(partner,family members,friends,work and social activities)were measured approximately every 3 years and scored from 0(very dissatisfied)to 3(very satisfied).Scores from each relationship type were summed to provide an overall satisfaction score(range:≤5–15).The outcome of interest was the accumulation of multimorbidity in 11 chronic conditions.Results Over a 20-year period,4484(58.3%)women reported multimorbidities.Overall,the level of social relationship satisfaction had a dose–response relationship with the accumulation of multimorbidities.Compared with women reporting the highest satisfaction(score 15),women with the lowest satisfaction(score≤5)had the highest odds of accumulating multimorbidity(odds ratio(OR)=2.35,95%confidence interval(CI):1.94 to 2.83)in the adjusted model.Similar results were observed for each social relationship type.Other risk factors,such as socioeconomic,behavioural and menopausal status,together explained 22.72%of the association.Conclusions Social relationship satisfaction is associated with the accumulation of multimorbidity,and the relationship is only partly explained by socioeconomic,behavioural and reproductive factors.Social connections(eg,satisfaction with social relationships)should be considered a public health priority in chronic disease prevention and intervention.展开更多
This study focused on the development of a new low viscosity automatic transmission fluid(ATF) with enhanced friction durability to meet the needs of new step type automatic transmissions.Recent high fuel prices encou...This study focused on the development of a new low viscosity automatic transmission fluid(ATF) with enhanced friction durability to meet the needs of new step type automatic transmissions.Recent high fuel prices encourage increased efficiency in the driveline,including the transmission.Reduction in fluid viscosity and wider use of slip control in torque converter clutches are two ways to practically improve fuel efficiency.Increased torque and more shifting is seen with a variety of new transmission hardware platforms,such as wet starting clutches,dual clutches and seven-or eight-speed ATs.This suggests the need for enhanced levels of friction durability from the ATF.The new challenge from this hardware for the ATF formulator lies in the need to simultaneously meet the wear,friction durability and torque capacity requirements at low viscosity in a cost-effective manner.This report introduced a new low viscosity fluid that represents a different commercial ATF formulation style.The new chemistry employs a low viscosity for increased fuel economy,while easily doubling the friction durability of current conventional ATFs and offering higher torque and better EP.展开更多
In particulate material transfer systems,traditional shear test based steady state analysis can provide some insight into the strength of the bulk material and subsequent resistive frictional forces during flow.For fa...In particulate material transfer systems,traditional shear test based steady state analysis can provide some insight into the strength of the bulk material and subsequent resistive frictional forces during flow.For fast flowing transfer points,dynamic flow conditions dominate and additional modelling techniques are required to improve design guidance.The research presented shows the evolution of a design solution which utilises two distinct processes;a continuum method and a discrete element method(DEM). Initially,the internal structure of dense granular flow,down vertical and inclined pipes was investigated using a twin sensor,12 electrode electrical capacitance tomography device.Subsequently,DEM simulations were conducted using the commercial software,PFC3D.Initially,two particle types and their flow behaviours were analysed:plastic pellets and sand.The pipe angle was varied between 0°and 45°to the vertical.For both the plastic pellets and the sand,good qualitative agreement was found with the spatial particle concentration analysis.Generally,the flow had a dense particle region at its core with the particle concentration reducing away from this core.As expected,at 0°, the core was centrally located within the pipe for both the plastic pellets and sand.At pipe angles 5°or greater,the dense core of particles was located on or near the pipe wall.Average flow velocity analysis was also conducted using the results of wall friction test analysis.The velocity comparisons also showed good agreement between the ECT image analysis and the DEM simulations. Subsequently,the DEM method was used to analyse a complex transfer system(or chute) with the continuum method providing comparative flow analysis with the DEM flow analysis.展开更多
Dear Editor,Sugarcane mosaic virus （SCMV） causes severe viral diseases in maize worldwide （Fuchs and Gruntzig, 1995）, resulting in significant losses in grain and forage yield in susceptible cultivars of maize and...Dear Editor,Sugarcane mosaic virus （SCMV） causes severe viral diseases in maize worldwide （Fuchs and Gruntzig, 1995）, resulting in significant losses in grain and forage yield in susceptible cultivars of maize and related crops. The most promising solution is to cultivate resistant varieties, which contribute to sustainable crop production. Two epistatically interacting major SCMV resistance loci （Scmvl and Scmv2） are required to confer complete resistance against SCMV in the resistant nearisogenic line F7RPJRR （the letters left of the slash refer to the genotype at Scmv2 on chromosome 3 and those on the right refer to the genotype at Scmvl on chromosome 6, with R indicating a resistance allele and S a susceptibility allele） （Xing et al., 2006）.展开更多
Vigorous particle collisions and mechanical processes occurring during high-velocity pneumatic con- veying often lead to particle degradation. The resulting particle size reduction and particle number increase will im...Vigorous particle collisions and mechanical processes occurring during high-velocity pneumatic con- veying often lead to particle degradation. The resulting particle size reduction and particle number increase will impact on the flow characteristics, and subsequently affect the electrostatic type of flow measurements. This study investigates this phenomenon using both experimental and numerical meth- ods. Particle degradation was induced experimentally by recursively conveying the fillite material within a pneumatic pipeline. The associated particle size reduction was monitored. Three electrostatic sensors were embedded along the pipeline to monitor the flow. The results indicated a decreasing trend in the electrostatic sensor outputs with decreasing particle size, which suggested the attenuation of the flow velocity fluctuation. This trend was more apparent at higher conveying velocities, which suggested that more severe particle degradation occurred under these conditions. Coupled computational fluid dynamics and discrete element methods （CFD-DEM） analysis was used to qualitatively validate these experimental results. The numerical results suggested that smaller particles exhibited lower flow velocity fluctua- tions, which was consistent with the observed experimental results. These findings provide important information for the accurate aoolication of electrostatic measurement devices in oneumatic conveyors.展开更多
文摘The stability of a set of spatially constant plane wave solutions to a pair of damped coupled nonlinear Schrödinger evolution equations is considered. The equations could model physical phenomena arising in fluid dynamics, fibre optics or electron plasmas. The main result is that any small perturbation to the solution remains small for all time. Here small is interpreted as being both in the supremum sense and the square integrable sense.
文摘The cosmopolitan calcifying alga Emiliania huxleyi is one of the most abundant bloom forming coccolithophore species in the oceans and plays an important role in global biogeochemical cycling. Coccolithoviruses are a major cause of coccolithophore bloom termination and have been studied in laboratory, mesocosm and open ocean studies. However, little is known about the dynamic interactions between the host and its viruses, and less is known about the natural diversity and role of functionally important genes within natural coccolithovirus communities. Here, we investigate the temporal and spatial distribution of coccolithoviruses by the use of molecular fingerprinting techniques PCR, DGGE and genomie sequencing. The natural biodiversity of the virus genes encoding the major capsid protein （MCP） and serine palmitoyltransferase （SPT） were analysed in samples obtained from the Atlantic Meridional Transect （AMT）, the North Sea and the L4 site in the Westem Channel Observatory. We discovered nine new coccolithovirus genotypes across the AMT and L4 site, with the majority of MCP sequences observed at the deep chlorophyll maximum layer of the sampled sites on the transect. We also found four new SPT gene variations in the North Sea and at L4. Their translated fragments and the full protein sequence of SPT from laboratory strains EhV-86 and EhV-99B 1 were modelled and revealed that the theoretical fold differs among strains. Variation identified in the structural distance between the two domains of the SPT protein may have an impact on the catalytic capabilities of its active site. In summary, the combined use of ＇standard＇ markers （i.e. MCP）, in combination with metabolically relevant markers （i.e. SPT） are useful in the study of the phylogeny and functional biodiversity of coccolithoviruses, and can provide an interesting intracellular insight into the evolution of these viruses and their ability to infect and replicate within their algal hosts.
基金This study was funded by Universities of Queensland and Newcastle,National Health and Medical Research Council Principal Research Fellowship(grant number:APP1121844)the University of Queensland,Australian Government Department of Health.
文摘Background Social relationships are associated with mortality and chronic conditions.However,little is known about the effects of social relationship satisfaction on multiple chronic conditions(multimorbidity).Aims To examine whether social relationship satisfaction is associated with the accumulation of multimorbidity.Methods Data from 7694 Australian women who were free from 11 chronic conditions at 45–50 years of age in 1996 were analysed.Five types of social relationship satisfaction(partner,family members,friends,work and social activities)were measured approximately every 3 years and scored from 0(very dissatisfied)to 3(very satisfied).Scores from each relationship type were summed to provide an overall satisfaction score(range:≤5–15).The outcome of interest was the accumulation of multimorbidity in 11 chronic conditions.Results Over a 20-year period,4484(58.3%)women reported multimorbidities.Overall,the level of social relationship satisfaction had a dose–response relationship with the accumulation of multimorbidities.Compared with women reporting the highest satisfaction(score 15),women with the lowest satisfaction(score≤5)had the highest odds of accumulating multimorbidity(odds ratio(OR)=2.35,95%confidence interval(CI):1.94 to 2.83)in the adjusted model.Similar results were observed for each social relationship type.Other risk factors,such as socioeconomic,behavioural and menopausal status,together explained 22.72%of the association.Conclusions Social relationship satisfaction is associated with the accumulation of multimorbidity,and the relationship is only partly explained by socioeconomic,behavioural and reproductive factors.Social connections(eg,satisfaction with social relationships)should be considered a public health priority in chronic disease prevention and intervention.
文摘This study focused on the development of a new low viscosity automatic transmission fluid(ATF) with enhanced friction durability to meet the needs of new step type automatic transmissions.Recent high fuel prices encourage increased efficiency in the driveline,including the transmission.Reduction in fluid viscosity and wider use of slip control in torque converter clutches are two ways to practically improve fuel efficiency.Increased torque and more shifting is seen with a variety of new transmission hardware platforms,such as wet starting clutches,dual clutches and seven-or eight-speed ATs.This suggests the need for enhanced levels of friction durability from the ATF.The new challenge from this hardware for the ATF formulator lies in the need to simultaneously meet the wear,friction durability and torque capacity requirements at low viscosity in a cost-effective manner.This report introduced a new low viscosity fluid that represents a different commercial ATF formulation style.The new chemistry employs a low viscosity for increased fuel economy,while easily doubling the friction durability of current conventional ATFs and offering higher torque and better EP.
文摘In particulate material transfer systems,traditional shear test based steady state analysis can provide some insight into the strength of the bulk material and subsequent resistive frictional forces during flow.For fast flowing transfer points,dynamic flow conditions dominate and additional modelling techniques are required to improve design guidance.The research presented shows the evolution of a design solution which utilises two distinct processes;a continuum method and a discrete element method(DEM). Initially,the internal structure of dense granular flow,down vertical and inclined pipes was investigated using a twin sensor,12 electrode electrical capacitance tomography device.Subsequently,DEM simulations were conducted using the commercial software,PFC3D.Initially,two particle types and their flow behaviours were analysed:plastic pellets and sand.The pipe angle was varied between 0°and 45°to the vertical.For both the plastic pellets and the sand,good qualitative agreement was found with the spatial particle concentration analysis.Generally,the flow had a dense particle region at its core with the particle concentration reducing away from this core.As expected,at 0°, the core was centrally located within the pipe for both the plastic pellets and sand.At pipe angles 5°or greater,the dense core of particles was located on or near the pipe wall.Average flow velocity analysis was also conducted using the results of wall friction test analysis.The velocity comparisons also showed good agreement between the ECT image analysis and the DEM simulations. Subsequently,the DEM method was used to analyse a complex transfer system(or chute) with the continuum method providing comparative flow analysis with the DEM flow analysis.
文摘Dear Editor,Sugarcane mosaic virus （SCMV） causes severe viral diseases in maize worldwide （Fuchs and Gruntzig, 1995）, resulting in significant losses in grain and forage yield in susceptible cultivars of maize and related crops. The most promising solution is to cultivate resistant varieties, which contribute to sustainable crop production. Two epistatically interacting major SCMV resistance loci （Scmvl and Scmv2） are required to confer complete resistance against SCMV in the resistant nearisogenic line F7RPJRR （the letters left of the slash refer to the genotype at Scmv2 on chromosome 3 and those on the right refer to the genotype at Scmvl on chromosome 6, with R indicating a resistance allele and S a susceptibility allele） （Xing et al., 2006）.
文摘Vigorous particle collisions and mechanical processes occurring during high-velocity pneumatic con- veying often lead to particle degradation. The resulting particle size reduction and particle number increase will impact on the flow characteristics, and subsequently affect the electrostatic type of flow measurements. This study investigates this phenomenon using both experimental and numerical meth- ods. Particle degradation was induced experimentally by recursively conveying the fillite material within a pneumatic pipeline. The associated particle size reduction was monitored. Three electrostatic sensors were embedded along the pipeline to monitor the flow. The results indicated a decreasing trend in the electrostatic sensor outputs with decreasing particle size, which suggested the attenuation of the flow velocity fluctuation. This trend was more apparent at higher conveying velocities, which suggested that more severe particle degradation occurred under these conditions. Coupled computational fluid dynamics and discrete element methods （CFD-DEM） analysis was used to qualitatively validate these experimental results. The numerical results suggested that smaller particles exhibited lower flow velocity fluctua- tions, which was consistent with the observed experimental results. These findings provide important information for the accurate aoolication of electrostatic measurement devices in oneumatic conveyors.
