We investigated forest road networks and forestry operations before and after mechanization on aggregated forestry operation sites. We developed equations to estimate densities of road networks with average slope angl...We investigated forest road networks and forestry operations before and after mechanization on aggregated forestry operation sites. We developed equations to estimate densities of road networks with average slope angles, operational efficiency of bunching operations with road network density, and average forwarding distances with operation site areas. Subsequently, we analyzed the effects of aggregating forests, establishing forest road networks, and mechanization on operational efficiency and costs. Six ha proved to be an appropriate operation site area with minimum operation expenses. The operation site areas of the forest owners＇ cooperative in this region aggregated approximately 6 ha and the cooperative conducted forestry operations on aggregated sites. Therefore, 6 ha would be an appropriate operation site area in this region. Regarding road network density, higher-density road networks increased operational expenses due to the higher direct operational expenses of strip road establishment. Therefore, road network density should be reduced to approximately 200 m.展开更多
The maximal entropy ordered weighted averaging （ME-OWA） operator is used to aggregate metasearch engine results, and its newly analytical solution is also applied. Within the current context of the OWA operator, the...The maximal entropy ordered weighted averaging （ME-OWA） operator is used to aggregate metasearch engine results, and its newly analytical solution is also applied. Within the current context of the OWA operator, the methods for aggregating metasearch engine results are divided into two kinds. One has a unique solution, and the other has multiple solutions. The proposed method not only has crisp weights, but also provides multiple aggregation results for decision makers to choose from. In order to prove the application of the ME-OWA operator method, under the context of aggregating metasearch engine results, an example is given, which shows the results obtained by the ME-OWA operator method and the minimax linear programming （ minimax-LP ） method. Comparison between these two methods are also made. The results show that the ME-OWA operator has nearly the same aggregation results as those of the minimax-LP method.展开更多
Genetic engineering in filamentous N2-fixing cyanobacteria usually involves Anabaena sp. PCC 7120 and several other non-aggregating species. Mass culture and harvest of such species are more energy consuming relative ...Genetic engineering in filamentous N2-fixing cyanobacteria usually involves Anabaena sp. PCC 7120 and several other non-aggregating species. Mass culture and harvest of such species are more energy consuming relative to aggregating species. To establish a gene transfer system for aggregating species, we tested many species of Anabaena and Nostoc, and identified Nostoc muscorum FACHB244 as a species that can be genetically manipulated using the conjugative gene transfer system. To promote biodegradation of organophosphorus pollutants in aquatic environments, we introduced a plasmid containing the organophosphorus-degradation gene （opd） into Anabaena sp. PCC 7120 and Nostoc muscorum FACHB244 by conjugation. The opd gene was driven by a strong promoter, Pp,bA. From both species, we obtained transgenic strains having organophosphorus-degradation activities. At 25~C, the whole-cell activities of the transgenic Anabaena and Nostoc strains were 0.163~0.001 and 0.289~0.042 unit/gg Chl a, respectively. However, most colonies resulting from the gene transfer showed no activity. PCR and DNA sequencing revealed deletions or rearrangements in the plasmid in some of the colonies. Expression of the green fluorescent protein gene from the same promoter in Anabaena sp. PCC 7120 showed similar results. These results suggest that there is the potential to promote the degradation of organophosphorus pollutants with transgenic cyanobacteria and that selection of high-expression transgenic colonies is important for genetic engineering of Anabaena and Nostoc species. For the first time, we established a gene transfer and expression system in an aggregating filamentous N2-fixing cyanobacterium. The genetic manipulation system of Nostoc muscorum FACHB244 could be utilized in the elimination of pollutants and large-scale production of valuable proteins or metabolites.展开更多
The coaggregating behavior of the cationic kinetic probe P16;with different types of surfactants are in complete agreement with predictions based on the newly proposed ESAg concept.
Marine fisheries in Kenya mainly comprise of the artisanal fishermen who use non-motorized boats. Competition of these dwindling resources has led to overfishing and degradation of coral reef ecosystems. One of the me...Marine fisheries in Kenya mainly comprise of the artisanal fishermen who use non-motorized boats. Competition of these dwindling resources has led to overfishing and degradation of coral reef ecosystems. One of the methods which have been used to enhance sustainable exploitation of fisheries resources is the use of Fish Aggregating Devices (FADs). The study was conducted in two areas along the Kenyan coast which are: Msambweni in the southern part and Kuruwitu (Vipingo) in the northern part of the Kenyan coast. A combination of systematic site surveys: structured and semi structured interviews with key informants (community leaders and resource users);participant observations;descriptions of daily and seasonal time use;and analyses of secondary sources, such as fisheries records, was used to gather information and triangulate results. The perception of the community about FADs was determined by conducting a socio-economic survey before and after deploying FADs. Colonization and biomass survey around the deployed FADs was undertaken and fish associated with FADs was recorded. Results indicate that nine families of fish aggregated around FADs and at different distances. Catch and effort at FADs have been evaluated by monitoring catch data from fishers on daily basis after deployments.展开更多
The influence on fine particle aggregation and flotation behavior induced by high intensity conditioning(HIC) from saturated of the slurry with CO2 saturation was investigated.Bubble size measurements were conducted.T...The influence on fine particle aggregation and flotation behavior induced by high intensity conditioning(HIC) from saturated of the slurry with CO2 saturation was investigated.Bubble size measurements were conducted.The effect of dissolved gas,xanthate addition and agitation speed on fine sphalerite particle aggregation-and flotation-behavior were studied.The results show that during HIC in air or CO2 saturated water xanthate acts as a frother.The dissolved gas content in the pulp and HIC play a synergistic role in promoting fine particle aggregation and hence flotation;a significantly enhanced aggregation of fine sphalerite particles in a CO2 saturated slurry by HIC is observed.The aggregate size increased when the agitation speed was increased from 700 r/min to 1500 r/min.Increasing the HIC speed to 1500 r/min caused a positive impact on flotation kinetics.Further increasing the speed to 2000 r/min resulted in an adverse effect on flotation kinetics.展开更多
The aggregating properties of Cz-C-n (n = 3, 6, 10) have been investigated by means of fluorescence method in DMSO-H2O binary solvent. The measured CAC and C F values indicate that the aggregating tendency of the amp...The aggregating properties of Cz-C-n (n = 3, 6, 10) have been investigated by means of fluorescence method in DMSO-H2O binary solvent. The measured CAC and C F values indicate that the aggregating tendency of the amphiphilic compounds Cz-C-n containing crown ether increases with the length of alkyl chains, similar to that of carbazole compounds with long alkyl chains.展开更多
At first sight, the choice of a socially best economic policy and the choice of an optimal engineering design seem to be quite separate issues. A closer look, however, shows that both approaches which aim at generatin...At first sight, the choice of a socially best economic policy and the choice of an optimal engineering design seem to be quite separate issues. A closer look, however, shows that both approaches which aim at generating a (set of) best alternative(s) have much in common. We describe and characterize axiomatically an aggregation method that uses a set of evaluations that are arranged on a common scale. This scale establishes a common language, so to speak, which conforms to the criteria that are deemed relevant in order to compare various design options. Two conditions are able to characterize the proposed aggregation mechanism. One is a simple dominance requirement, and the other called cancellation independence makes use of the fact that for any pair of objects, rank differences of opposite sign can be reduced without changing the aggregate outcome of the ranking procedure. The proposed method has its origin in voting theory but may have the potential to prove useful in engineering design as well.展开更多
The aggregating process of particle suspension systems is a very universal phenomena and crucial for various processes both in nature and in industry.In this paper,the aggregating process was simulated with offlattice...The aggregating process of particle suspension systems is a very universal phenomena and crucial for various processes both in nature and in industry.In this paper,the aggregating process was simulated with offlattice diffusion-limited cluster-cluster aggregation(DLCA)Monte Carlo programs.The self-similar fractal structures of aggregates have been clearly demonstrated by the statistical analysis of gyration radius distribution and the existence of a scaling distribution of the reduced cluster size.The fractal dimension determined from the relationship between mass and gyration radius of aggregates was 1.80 or so.The fractal dimension of the aggregates drawn from the radial distribution function and structure factor of a single aggregate is about 1.90-2.10.It was also showed that,along with the increasing of particle volume fraction,the fractal dimension will increase in a nearly square root manner,and the spatial range of the fractal structure appearing becomes narrower.Also,the gelation transition can only occur in a particle suspension system where the particle volume fraction is greater than a critical value.展开更多
In modern construction,Lightweight Aggregate Concrete(LWAC)has been recognized as a vital material of concern because of its unique properties,such as reduced density and improved thermal insulation.Despite the extens...In modern construction,Lightweight Aggregate Concrete(LWAC)has been recognized as a vital material of concern because of its unique properties,such as reduced density and improved thermal insulation.Despite the extensive knowledge regarding its macroscopic properties,there is a wide knowledge gap in understanding the influence of microscale parameters like aggregate porosity and volume ratio on the mechanical response of LWAC.This study aims to bridge this knowledge gap,spurred by the need to enhance the predictability and applicability of LWAC in various construction environments.With the help of advanced numerical methods,including the finite element method and a random circular aggregate model,this study critically evaluates the role played by these microscale factors.We found that an increase in the aggregate porosity from 23.5%to 48.5%leads to a drastic change of weakness from the bonding interface to the aggregate,reducing compressive strength by up to 24.2%and tensile strength by 27.8%.Similarly,the increase in the volume ratio of lightweight aggregate from 25%to 40%leads to a reduction in compressive strength by 13.0%and tensile strength by 9.23%.These results highlight the imperative role of microscale properties on the mechanical properties of LWAC.By supplying precise quantitative details on the effect of porosity and aggregate volume ratio,this research makes significant contributions to construction materials science by providing useful recommendations for the creation and optimization of LWAC with improved performance and sustainability in construction.展开更多
Freeze-thaw cycles(FTCs)have an important effect on soil aggregate stability by altering soil structures,thereby influencing soil wind and water erosion on the eastern Qinghai-Tibet Plateau.However,the effects of FTCs...Freeze-thaw cycles(FTCs)have an important effect on soil aggregate stability by altering soil structures,thereby influencing soil wind and water erosion on the eastern Qinghai-Tibet Plateau.However,the effects of FTCs on the stability of these soils remain unclear.Here,we conducted freeze-thaw simulations in laboratory to investigate the effects of FTCs(0 to 15 cycles)on the wet-and dry-sieving aggregate stability of undisturbed sandy loam from Maqu county,which was treated with different initial soil moisture contents(1%to 25%in increments of 4%)and initial aggregate diameters(<2,2-5,5-10,and 10-15 mm).Results show that soil aggregates with initial diameters larger than 2 mm exhibit higher soil organic carbon contents(1.45%-1.57%)and silt contents(34.63%-35.52%)than those smaller than 2 mm(0.93%and 31.38%,respectively).The stability of both wet-and dry-sieving aggregates increases with larger initial diameters.Increasing initial soil moisture content from 1%to 25%reduces aggregate stability,with reductions of 2.4%-88.0%for wet-sieving aggregates and 2.1%-25.5%for dry-sieving aggregates(>2 mm).With increasing FTCs,wet-sieving aggregate(>2 mm)stability exhibits a fluctuating upward trend,with increases of 79.2%-87.4%after 15 FTCs,while dry-sieving aggregate(>2 mm)stability decreases significantly(5.7%-21.7%)upon the first FTC and remains unchanged thereafter.The stability of both the wet-and dry-sieving aggregates smaller than 2 mm remains unchanged with increasing FTCs(p>0.05).SOC content decreases by 22.3%on average with increasing FTCs from 1 to 15 and shows no significant correlations with wet-and dry-sieving aggregate stability.Higher silt content(r=0.39,p<0.05)and lower sand content(r=-0.38,p<0.05)enhances the wet-sieving aggregate stability of sandy loam.Frequent FTCs tend to improve wet-sieving aggregate stability but reduce dry-sieving aggregate stability in the sandy loam.The findings provide certain guidance for preventing freeze-thaw-induced wind erosion.展开更多
Protein aggregates,mitochondrial import stress and neurodegenerative disorders:A salient hallmark of several neurodegenerative diseases,including Parkinson’s disease,is the abundance of protein aggregates(Goiran et a...Protein aggregates,mitochondrial import stress and neurodegenerative disorders:A salient hallmark of several neurodegenerative diseases,including Parkinson’s disease,is the abundance of protein aggregates(Goiran et al.,2022).This molecular event is believed to lead to activation of stress pathways ultimately resulting in cellular dysfunction(Eldeeb et al.,2022).Accordingly,many lines of research investigations focused on dampening the formation of protein aggregates or augmenting the clearance of protein aggregates as a potential therapeutic strategy to counteract the progression of neurodegenerative diseases,albeit with little success(Costa-Mattioli and Walter,2020).Cell stress cues such as the accumulation of protein aggregates lead to the activation of stress response pathways that aid cells in responding to the damage.Despite the notion that the transient activation of these pathways helps cells cope with stressors,persistent activation can induce unwanted apoptosis of cells and reduce overall tissue strength as well as lead to an accumulation of aggregation-prone proteins(Hetz and Papa,2018).Mutations in proteins involved in stress signaling termination can cause conditions like ataxia and early-onset dementia(Conroy et al.,2014).Therefore,it is crucial for stress response signaling to be turned off once conditions have improved.Nevertheless,the mechanisms by which cells silence these signals are still elusive.展开更多
Concrete production often relies on natural aggregates,which can lead to resource depletion and environmental harm.In addition,improper disposal of thermoplastic waste exacerbates ecological problems.Although signific...Concrete production often relies on natural aggregates,which can lead to resource depletion and environmental harm.In addition,improper disposal of thermoplastic waste exacerbates ecological problems.Although significant attention has recently been given to recycling various waste materials into concrete,studies specifically addressing thermoplastic recycled aggregates are still trending.This underscores the need to comprehensively review existing literature,identify research trends,and recognize gaps in understanding the mechanical performance of thermoplastic-based recycled aggregate concrete.Accordingly,this review summarizes recent investigations focused on the mechanical properties of thermoplastic-based recycled aggregate concrete,emphasizing aspects such as compressive strength,tensile behavior,modulus of elasticity,and durability characteristics.The primary aim is to consolidate scattered research findings,identify key parameters influencing mechanical behavior,and propose future research directions.Understanding the influence of recycled thermoplastic aggregates on concrete performance significantly supports sustainable construction practices by reducing dependency on virgin aggregates and mitigating environmental impacts associated with waste disposal.In addition,assessing mechanical performance contributes to confidence in the practical application,encouraging the broader adoption of thermoplastic-based recycled aggregate concrete in construction projects.Through this critical synthesis,the review guides researchers and industry practitioners toward informed decisions on the feasibility and reliability of integrating thermoplastic waste into concrete,thereby promoting sustainable infrastructure development.展开更多
The large-scale deployment of Internet of Things(IoT)technology across various aspects of daily life has significantly propelled the intelligent development of society.Among them,the integration of IoT and named data ...The large-scale deployment of Internet of Things(IoT)technology across various aspects of daily life has significantly propelled the intelligent development of society.Among them,the integration of IoT and named data networks(NDNs)reduces network complexity and provides practical directions for content-oriented network design.However,ensuring data integrity in NDN-IoT applications remains a challenging issue.Very recently,Wang et al.(Entropy,27(5),471(2025))designed a certificateless aggregate signature(CLAS)scheme for NDN-IoT environments.Wang et al.stated that their construction was provably secure under various types of security attacks.Using theoretical analysis methods,in this work,we reveal that their CLAS design fails to meet unforgeability,a core security requirement for CLAS schemes.In particular,we demonstrate that their scheme is vulnerable to amalicious public-key replacement attack,enabling an adversary to produce authentic signatures for arbitrary fraudulent messages.Therefore,Wang et al.’s design cannot achieve its goal.To address the issue,we systematically examine the root causes behind the vulnerability and propose a security-enhanced CLAS construction for NDN-IoT environments.We prove the security ofour improveddesignunder the standard security assumptionandalsoanalyze its practicalperformanceby comparing the computational and communication costs with several related works.The comparison results show the practicality of our design.展开更多
Amyloid protein aggregation plays a major role in multiple neurodegenerative diseases and is likely the primary driving force for the progression of most of these diseases.Multiple recent studies have highlighted that...Amyloid protein aggregation plays a major role in multiple neurodegenerative diseases and is likely the primary driving force for the progression of most of these diseases.Multiple recent studies have highlighted that the DNAJ homolog subfamily B member 6(DNAJB6)chaperone is particularly interesting,when it comes to preventing amyloidogenic proteins from aggregating.It has been shown that DNAJB6 can prevent the aggregation of polyglutamine-expanded proteins in models of Huntington’s disease.Likewise,it can suppress aggregation ofα-synuclein in models of Parkinson’s disease and other synucleinopathies.Finally,it has been shown that DNAJB6 can block aggregation of multiple additional amyloid proteins involved in Alzheimer’s disease and other tauopathies as well.We believe there is yet much to learn about the protective role of DNAJB6 in the brain,but this focused review summarizes,what we know so far of this chaperone.It describes the biological role of DNAJB6 in the brain and its interaction with Hsp70,with particular emphasis on the studies that show its ability to prevent amyloid protein aggregation in vitro and in vivo.Moreover,recent work on dysregulation of the expression of DNAJB6 in brain clinical tissue is discussed.Finally,we discuss potential therapeutic perspectives as we believe this protein is a promising druggable target.展开更多
We investigated the effects of fly ash(FA)content on the mechanical properties of recycled aggregate concrete(RAC)and its regeneration potential under freeze and thaw(F-T)cycles.The physical properties of second-gener...We investigated the effects of fly ash(FA)content on the mechanical properties of recycled aggregate concrete(RAC)and its regeneration potential under freeze and thaw(F-T)cycles.The physical properties of second-generation recycled concrete aggregates(RCA)were used to analyze the regeneration potential of RAC after F-T cycles.Scanning electron microscopy was used to study the interfacial transition zone microstructure of RAC after F-T cycles.Results showed that adding 20%FA to RAC significantly enhanced its mechanical properties and frost resistance.Before the F-T cycles,the compressive strength of RAC with 20%FA reached 48.3 MPa,exceeding research strength target of 40 MPa.A majority of second-generation RCA with FA had been verified to attain class Ⅲ,which enabled their practical application in non-structural projects such as backfill trenches and road pavement.However,the second-generation RCA with 20%FA can achieve class Ⅱ,making it ideal for 40 MPa structural concrete.展开更多
Insight into the carbon turnover in soil aggregates and density fractions is essential for reducing the uncertainty in estimating carbon pools on the Tibetan Plateau,and how they vary with land use type is unclear.In ...Insight into the carbon turnover in soil aggregates and density fractions is essential for reducing the uncertainty in estimating carbon pools on the Tibetan Plateau,and how they vary with land use type is unclear.In this study,the effect of land use type on carbon storage and fractionation was quantified based on organic carbon and its ^(13)C abundance at the microscale of soil aggregates and density fractions in Tibetan alpine ecosystems.The sequence of soil aggregate destruction in the land use types of plantation(13.1%)<shrubland(32.7%)<grassland(47.9%)<farmland(61.8%)shows that plantations strengthen the soil structure.Plantation land had a greater contribution of light fraction organic carbon(28.3%)but a lower contribution of mineral-associated organic carbon(40.6%)to the carbon stock compared to farmland(13.5 and 70.3%).Interestingly,plantation land enhanced the aggregational differentiation of organic carbon and ^(13)C in each density fraction,whereas no such phenomenon existed in the soil organic carbon.Carbon isotope analyses revealed that carbon transfer in the plantation land occurred from the light fraction in macroaggregates(–24.9‰)to the mineral-associated fraction in microaggregates(–19.9‰).When compared to the other three land use types,the low transferability of carbon in aggregates and density fractions in plantation land provides a stable carbon pool for the Tibetan Plateau.This study shows that plantations can mitigate global climate change by slowing carbon transfer and increasing carbon storage at the microscale of aggregates and density fractions in alpine regions.展开更多
Crushing waste coral concrete into recycled aggregates to create recycled coral aggregate concrete(RCAC)contributes to sustainable construction development on offshore islands and reefs.To investigate the impact of re...Crushing waste coral concrete into recycled aggregates to create recycled coral aggregate concrete(RCAC)contributes to sustainable construction development on offshore islands and reefs.To investigate the impact of recycled coral aggregate on concrete properties,this study performed a comprehensive analysis of the physical properties of recycled coral aggregate and the basic mechanical properties and microstructure of RCAC.The test results indicate that,compared to coral debris,the crushing index of recycled coral aggregate was reduced by 9.4%,while porosity decreased by 33.5%.Furthermore,RCAC retained the early strength characteristics of coral concrete,with compressive strength and flexural strength exhibiting a notable increase as the water-cement ratio decreased.Under identical conditions,the compressive strength and flexural strength of RCAC were 12.7% and 2.5% higher than coral concrete's,respectively,with porosity correspondingly reduced from 3.13% to 5.11%.This enhancement could be attributed to the new mortar filling the recycled coral aggregate.Scanning electron microscopy(SEM)analysis revealed three distinct interface transition zones within RCAC,with the‘new mortar-old mortar’interface identified as the weakest.The above findings provided a reference for the sustainable use of coral concrete in constructing offshore islands.展开更多
As renewable energy penetration continues to rise,enhancing power system flexibility has become a critical requirement.Photovoltaic–storage–charging stations(PSCSs)are key components for enhancing local regulation c...As renewable energy penetration continues to rise,enhancing power system flexibility has become a critical requirement.Photovoltaic–storage–charging stations(PSCSs)are key components for enhancing local regulation capability and promoting renewable integration.However,evaluating the adjustable capability of such hybrid stations while considering security constraints remains a major challenge.This paper first analyzes the adjustable capabilities of all the resources within such a station based on the power-energy boundary(PEB)model.Then,an optimal formulation is proposed to obtain the adjusted parameters of the aggregate feasible region(AFR)model,which embeds low-dimensional linear models within high-dimensional linear models to improve the accuracy.To solve this formulation,it is transformed using duality theory and an alternating optimization algorithm is designed to obtain the solution.Finally,a multi-station adjustable capability aggregation method considering security constraints is introduced.Simulation results verify that the proposed method effectively reduces infeasible regions and improves smoothness of aggregated boundaries,providing an accurate and practical tool for flexibility evaluation in PSCSs and offering guidance for aggregators and system planners.展开更多
文摘We investigated forest road networks and forestry operations before and after mechanization on aggregated forestry operation sites. We developed equations to estimate densities of road networks with average slope angles, operational efficiency of bunching operations with road network density, and average forwarding distances with operation site areas. Subsequently, we analyzed the effects of aggregating forests, establishing forest road networks, and mechanization on operational efficiency and costs. Six ha proved to be an appropriate operation site area with minimum operation expenses. The operation site areas of the forest owners＇ cooperative in this region aggregated approximately 6 ha and the cooperative conducted forestry operations on aggregated sites. Therefore, 6 ha would be an appropriate operation site area in this region. Regarding road network density, higher-density road networks increased operational expenses due to the higher direct operational expenses of strip road establishment. Therefore, road network density should be reduced to approximately 200 m.
基金The National Natural Science Foundation of China(No.71171048)
文摘The maximal entropy ordered weighted averaging （ME-OWA） operator is used to aggregate metasearch engine results, and its newly analytical solution is also applied. Within the current context of the OWA operator, the methods for aggregating metasearch engine results are divided into two kinds. One has a unique solution, and the other has multiple solutions. The proposed method not only has crisp weights, but also provides multiple aggregation results for decision makers to choose from. In order to prove the application of the ME-OWA operator method, under the context of aggregating metasearch engine results, an example is given, which shows the results obtained by the ME-OWA operator method and the minimax linear programming （ minimax-LP ） method. Comparison between these two methods are also made. The results show that the ME-OWA operator has nearly the same aggregation results as those of the minimax-LP method.
基金Supported by the National High Technology Research and Development Program of China (863 Program) (No. 2002AA601170)the National Natural Science Foundation of China (No. 30623001)
文摘Genetic engineering in filamentous N2-fixing cyanobacteria usually involves Anabaena sp. PCC 7120 and several other non-aggregating species. Mass culture and harvest of such species are more energy consuming relative to aggregating species. To establish a gene transfer system for aggregating species, we tested many species of Anabaena and Nostoc, and identified Nostoc muscorum FACHB244 as a species that can be genetically manipulated using the conjugative gene transfer system. To promote biodegradation of organophosphorus pollutants in aquatic environments, we introduced a plasmid containing the organophosphorus-degradation gene （opd） into Anabaena sp. PCC 7120 and Nostoc muscorum FACHB244 by conjugation. The opd gene was driven by a strong promoter, Pp,bA. From both species, we obtained transgenic strains having organophosphorus-degradation activities. At 25~C, the whole-cell activities of the transgenic Anabaena and Nostoc strains were 0.163~0.001 and 0.289~0.042 unit/gg Chl a, respectively. However, most colonies resulting from the gene transfer showed no activity. PCR and DNA sequencing revealed deletions or rearrangements in the plasmid in some of the colonies. Expression of the green fluorescent protein gene from the same promoter in Anabaena sp. PCC 7120 showed similar results. These results suggest that there is the potential to promote the degradation of organophosphorus pollutants with transgenic cyanobacteria and that selection of high-expression transgenic colonies is important for genetic engineering of Anabaena and Nostoc species. For the first time, we established a gene transfer and expression system in an aggregating filamentous N2-fixing cyanobacterium. The genetic manipulation system of Nostoc muscorum FACHB244 could be utilized in the elimination of pollutants and large-scale production of valuable proteins or metabolites.
文摘The coaggregating behavior of the cationic kinetic probe P16;with different types of surfactants are in complete agreement with predictions based on the newly proposed ESAg concept.
文摘Marine fisheries in Kenya mainly comprise of the artisanal fishermen who use non-motorized boats. Competition of these dwindling resources has led to overfishing and degradation of coral reef ecosystems. One of the methods which have been used to enhance sustainable exploitation of fisheries resources is the use of Fish Aggregating Devices (FADs). The study was conducted in two areas along the Kenyan coast which are: Msambweni in the southern part and Kuruwitu (Vipingo) in the northern part of the Kenyan coast. A combination of systematic site surveys: structured and semi structured interviews with key informants (community leaders and resource users);participant observations;descriptions of daily and seasonal time use;and analyses of secondary sources, such as fisheries records, was used to gather information and triangulate results. The perception of the community about FADs was determined by conducting a socio-economic survey before and after deploying FADs. Colonization and biomass survey around the deployed FADs was undertaken and fish associated with FADs was recorded. Results indicate that nine families of fish aggregated around FADs and at different distances. Catch and effort at FADs have been evaluated by monitoring catch data from fishers on daily basis after deployments.
基金Project 50674103 supported by the National Natural Science Foundation of China
文摘The influence on fine particle aggregation and flotation behavior induced by high intensity conditioning(HIC) from saturated of the slurry with CO2 saturation was investigated.Bubble size measurements were conducted.The effect of dissolved gas,xanthate addition and agitation speed on fine sphalerite particle aggregation-and flotation-behavior were studied.The results show that during HIC in air or CO2 saturated water xanthate acts as a frother.The dissolved gas content in the pulp and HIC play a synergistic role in promoting fine particle aggregation and hence flotation;a significantly enhanced aggregation of fine sphalerite particles in a CO2 saturated slurry by HIC is observed.The aggregate size increased when the agitation speed was increased from 700 r/min to 1500 r/min.Increasing the HIC speed to 1500 r/min caused a positive impact on flotation kinetics.Further increasing the speed to 2000 r/min resulted in an adverse effect on flotation kinetics.
基金We thank the National Natural Science Foundation of China. The foundation of the Ministry of Science and Technology of China (grant No. G2000078104 and No. G2000077502) for financial supports.
文摘The aggregating properties of Cz-C-n (n = 3, 6, 10) have been investigated by means of fluorescence method in DMSO-H2O binary solvent. The measured CAC and C F values indicate that the aggregating tendency of the amphiphilic compounds Cz-C-n containing crown ether increases with the length of alkyl chains, similar to that of carbazole compounds with long alkyl chains.
文摘At first sight, the choice of a socially best economic policy and the choice of an optimal engineering design seem to be quite separate issues. A closer look, however, shows that both approaches which aim at generating a (set of) best alternative(s) have much in common. We describe and characterize axiomatically an aggregation method that uses a set of evaluations that are arranged on a common scale. This scale establishes a common language, so to speak, which conforms to the criteria that are deemed relevant in order to compare various design options. Two conditions are able to characterize the proposed aggregation mechanism. One is a simple dominance requirement, and the other called cancellation independence makes use of the fact that for any pair of objects, rank differences of opposite sign can be reduced without changing the aggregate outcome of the ranking procedure. The proposed method has its origin in voting theory but may have the potential to prove useful in engineering design as well.
基金the Foundation of Key Laboratory of National Defense Science and Technology of Plasma Physics,China(No.9140C6806020707)the Foundation of China Academy of Engineering Physics(No.2007B08008)for the support.
文摘The aggregating process of particle suspension systems is a very universal phenomena and crucial for various processes both in nature and in industry.In this paper,the aggregating process was simulated with offlattice diffusion-limited cluster-cluster aggregation(DLCA)Monte Carlo programs.The self-similar fractal structures of aggregates have been clearly demonstrated by the statistical analysis of gyration radius distribution and the existence of a scaling distribution of the reduced cluster size.The fractal dimension determined from the relationship between mass and gyration radius of aggregates was 1.80 or so.The fractal dimension of the aggregates drawn from the radial distribution function and structure factor of a single aggregate is about 1.90-2.10.It was also showed that,along with the increasing of particle volume fraction,the fractal dimension will increase in a nearly square root manner,and the spatial range of the fractal structure appearing becomes narrower.Also,the gelation transition can only occur in a particle suspension system where the particle volume fraction is greater than a critical value.
基金supported by National Science Foundation of China(10972015,11172015)the Beijing Natural Science Foundation(8162008).
文摘In modern construction,Lightweight Aggregate Concrete(LWAC)has been recognized as a vital material of concern because of its unique properties,such as reduced density and improved thermal insulation.Despite the extensive knowledge regarding its macroscopic properties,there is a wide knowledge gap in understanding the influence of microscale parameters like aggregate porosity and volume ratio on the mechanical response of LWAC.This study aims to bridge this knowledge gap,spurred by the need to enhance the predictability and applicability of LWAC in various construction environments.With the help of advanced numerical methods,including the finite element method and a random circular aggregate model,this study critically evaluates the role played by these microscale factors.We found that an increase in the aggregate porosity from 23.5%to 48.5%leads to a drastic change of weakness from the bonding interface to the aggregate,reducing compressive strength by up to 24.2%and tensile strength by 27.8%.Similarly,the increase in the volume ratio of lightweight aggregate from 25%to 40%leads to a reduction in compressive strength by 13.0%and tensile strength by 9.23%.These results highlight the imperative role of microscale properties on the mechanical properties of LWAC.By supplying precise quantitative details on the effect of porosity and aggregate volume ratio,this research makes significant contributions to construction materials science by providing useful recommendations for the creation and optimization of LWAC with improved performance and sustainability in construction.
基金supported by National Natural Science Foundation of China(Grant No.42201080)Young Scientific and Technological Talents Program of Shaanxi Province(Grant No.2025ZC-KJXX-57)Special Scientific Research Program of the Shaanxi Provincial Department of Education(Grant No.21JK0967)。
文摘Freeze-thaw cycles(FTCs)have an important effect on soil aggregate stability by altering soil structures,thereby influencing soil wind and water erosion on the eastern Qinghai-Tibet Plateau.However,the effects of FTCs on the stability of these soils remain unclear.Here,we conducted freeze-thaw simulations in laboratory to investigate the effects of FTCs(0 to 15 cycles)on the wet-and dry-sieving aggregate stability of undisturbed sandy loam from Maqu county,which was treated with different initial soil moisture contents(1%to 25%in increments of 4%)and initial aggregate diameters(<2,2-5,5-10,and 10-15 mm).Results show that soil aggregates with initial diameters larger than 2 mm exhibit higher soil organic carbon contents(1.45%-1.57%)and silt contents(34.63%-35.52%)than those smaller than 2 mm(0.93%and 31.38%,respectively).The stability of both wet-and dry-sieving aggregates increases with larger initial diameters.Increasing initial soil moisture content from 1%to 25%reduces aggregate stability,with reductions of 2.4%-88.0%for wet-sieving aggregates and 2.1%-25.5%for dry-sieving aggregates(>2 mm).With increasing FTCs,wet-sieving aggregate(>2 mm)stability exhibits a fluctuating upward trend,with increases of 79.2%-87.4%after 15 FTCs,while dry-sieving aggregate(>2 mm)stability decreases significantly(5.7%-21.7%)upon the first FTC and remains unchanged thereafter.The stability of both the wet-and dry-sieving aggregates smaller than 2 mm remains unchanged with increasing FTCs(p>0.05).SOC content decreases by 22.3%on average with increasing FTCs from 1 to 15 and shows no significant correlations with wet-and dry-sieving aggregate stability.Higher silt content(r=0.39,p<0.05)and lower sand content(r=-0.38,p<0.05)enhances the wet-sieving aggregate stability of sandy loam.Frequent FTCs tend to improve wet-sieving aggregate stability but reduce dry-sieving aggregate stability in the sandy loam.The findings provide certain guidance for preventing freeze-thaw-induced wind erosion.
文摘Protein aggregates,mitochondrial import stress and neurodegenerative disorders:A salient hallmark of several neurodegenerative diseases,including Parkinson’s disease,is the abundance of protein aggregates(Goiran et al.,2022).This molecular event is believed to lead to activation of stress pathways ultimately resulting in cellular dysfunction(Eldeeb et al.,2022).Accordingly,many lines of research investigations focused on dampening the formation of protein aggregates or augmenting the clearance of protein aggregates as a potential therapeutic strategy to counteract the progression of neurodegenerative diseases,albeit with little success(Costa-Mattioli and Walter,2020).Cell stress cues such as the accumulation of protein aggregates lead to the activation of stress response pathways that aid cells in responding to the damage.Despite the notion that the transient activation of these pathways helps cells cope with stressors,persistent activation can induce unwanted apoptosis of cells and reduce overall tissue strength as well as lead to an accumulation of aggregation-prone proteins(Hetz and Papa,2018).Mutations in proteins involved in stress signaling termination can cause conditions like ataxia and early-onset dementia(Conroy et al.,2014).Therefore,it is crucial for stress response signaling to be turned off once conditions have improved.Nevertheless,the mechanisms by which cells silence these signals are still elusive.
文摘Concrete production often relies on natural aggregates,which can lead to resource depletion and environmental harm.In addition,improper disposal of thermoplastic waste exacerbates ecological problems.Although significant attention has recently been given to recycling various waste materials into concrete,studies specifically addressing thermoplastic recycled aggregates are still trending.This underscores the need to comprehensively review existing literature,identify research trends,and recognize gaps in understanding the mechanical performance of thermoplastic-based recycled aggregate concrete.Accordingly,this review summarizes recent investigations focused on the mechanical properties of thermoplastic-based recycled aggregate concrete,emphasizing aspects such as compressive strength,tensile behavior,modulus of elasticity,and durability characteristics.The primary aim is to consolidate scattered research findings,identify key parameters influencing mechanical behavior,and propose future research directions.Understanding the influence of recycled thermoplastic aggregates on concrete performance significantly supports sustainable construction practices by reducing dependency on virgin aggregates and mitigating environmental impacts associated with waste disposal.In addition,assessing mechanical performance contributes to confidence in the practical application,encouraging the broader adoption of thermoplastic-based recycled aggregate concrete in construction projects.Through this critical synthesis,the review guides researchers and industry practitioners toward informed decisions on the feasibility and reliability of integrating thermoplastic waste into concrete,thereby promoting sustainable infrastructure development.
基金supported in part by theHubei Engineering Research Center for BDS-CloudHigh-Precision Deformation Monitoring Open Funding(No.HBBDGJ202507Y)the National Natural Science Foundation of China(No.62377037).
文摘The large-scale deployment of Internet of Things(IoT)technology across various aspects of daily life has significantly propelled the intelligent development of society.Among them,the integration of IoT and named data networks(NDNs)reduces network complexity and provides practical directions for content-oriented network design.However,ensuring data integrity in NDN-IoT applications remains a challenging issue.Very recently,Wang et al.(Entropy,27(5),471(2025))designed a certificateless aggregate signature(CLAS)scheme for NDN-IoT environments.Wang et al.stated that their construction was provably secure under various types of security attacks.Using theoretical analysis methods,in this work,we reveal that their CLAS design fails to meet unforgeability,a core security requirement for CLAS schemes.In particular,we demonstrate that their scheme is vulnerable to amalicious public-key replacement attack,enabling an adversary to produce authentic signatures for arbitrary fraudulent messages.Therefore,Wang et al.’s design cannot achieve its goal.To address the issue,we systematically examine the root causes behind the vulnerability and propose a security-enhanced CLAS construction for NDN-IoT environments.We prove the security ofour improveddesignunder the standard security assumptionandalsoanalyze its practicalperformanceby comparing the computational and communication costs with several related works.The comparison results show the practicality of our design.
文摘Amyloid protein aggregation plays a major role in multiple neurodegenerative diseases and is likely the primary driving force for the progression of most of these diseases.Multiple recent studies have highlighted that the DNAJ homolog subfamily B member 6(DNAJB6)chaperone is particularly interesting,when it comes to preventing amyloidogenic proteins from aggregating.It has been shown that DNAJB6 can prevent the aggregation of polyglutamine-expanded proteins in models of Huntington’s disease.Likewise,it can suppress aggregation ofα-synuclein in models of Parkinson’s disease and other synucleinopathies.Finally,it has been shown that DNAJB6 can block aggregation of multiple additional amyloid proteins involved in Alzheimer’s disease and other tauopathies as well.We believe there is yet much to learn about the protective role of DNAJB6 in the brain,but this focused review summarizes,what we know so far of this chaperone.It describes the biological role of DNAJB6 in the brain and its interaction with Hsp70,with particular emphasis on the studies that show its ability to prevent amyloid protein aggregation in vitro and in vivo.Moreover,recent work on dysregulation of the expression of DNAJB6 in brain clinical tissue is discussed.Finally,we discuss potential therapeutic perspectives as we believe this protein is a promising druggable target.
基金Funded by the Natural Science Foundation of Jiangsu Province(No.BK20220626)the National Natural Science Foundation of China(No.52078068)+2 种基金Science and Technology Innovation Foundation of NIT(No.KCTD006)Jiangsu Marine Structure Service Performance Improvement Engineering Research CenterKey Laboratory of Jiangsu"Marine Floating Wind Power Technology and Equipment"。
文摘We investigated the effects of fly ash(FA)content on the mechanical properties of recycled aggregate concrete(RAC)and its regeneration potential under freeze and thaw(F-T)cycles.The physical properties of second-generation recycled concrete aggregates(RCA)were used to analyze the regeneration potential of RAC after F-T cycles.Scanning electron microscopy was used to study the interfacial transition zone microstructure of RAC after F-T cycles.Results showed that adding 20%FA to RAC significantly enhanced its mechanical properties and frost resistance.Before the F-T cycles,the compressive strength of RAC with 20%FA reached 48.3 MPa,exceeding research strength target of 40 MPa.A majority of second-generation RCA with FA had been verified to attain class Ⅲ,which enabled their practical application in non-structural projects such as backfill trenches and road pavement.However,the second-generation RCA with 20%FA can achieve class Ⅱ,making it ideal for 40 MPa structural concrete.
基金financially supported by the National Natural Science Foundation of China (42477044,32171648 and U23A2017)the Hubei Provincial Science and Technology Program,China (2025AFD451 and 2022CFB030)。
文摘Insight into the carbon turnover in soil aggregates and density fractions is essential for reducing the uncertainty in estimating carbon pools on the Tibetan Plateau,and how they vary with land use type is unclear.In this study,the effect of land use type on carbon storage and fractionation was quantified based on organic carbon and its ^(13)C abundance at the microscale of soil aggregates and density fractions in Tibetan alpine ecosystems.The sequence of soil aggregate destruction in the land use types of plantation(13.1%)<shrubland(32.7%)<grassland(47.9%)<farmland(61.8%)shows that plantations strengthen the soil structure.Plantation land had a greater contribution of light fraction organic carbon(28.3%)but a lower contribution of mineral-associated organic carbon(40.6%)to the carbon stock compared to farmland(13.5 and 70.3%).Interestingly,plantation land enhanced the aggregational differentiation of organic carbon and ^(13)C in each density fraction,whereas no such phenomenon existed in the soil organic carbon.Carbon isotope analyses revealed that carbon transfer in the plantation land occurred from the light fraction in macroaggregates(–24.9‰)to the mineral-associated fraction in microaggregates(–19.9‰).When compared to the other three land use types,the low transferability of carbon in aggregates and density fractions in plantation land provides a stable carbon pool for the Tibetan Plateau.This study shows that plantations can mitigate global climate change by slowing carbon transfer and increasing carbon storage at the microscale of aggregates and density fractions in alpine regions.
基金Funded by Natural Science Foundation of Guangxi(No.2025GXNSFBA069565)Guangxi Science and Technology Program(No.AD25069101)Guangxi Bagui Scholars Fund。
文摘Crushing waste coral concrete into recycled aggregates to create recycled coral aggregate concrete(RCAC)contributes to sustainable construction development on offshore islands and reefs.To investigate the impact of recycled coral aggregate on concrete properties,this study performed a comprehensive analysis of the physical properties of recycled coral aggregate and the basic mechanical properties and microstructure of RCAC.The test results indicate that,compared to coral debris,the crushing index of recycled coral aggregate was reduced by 9.4%,while porosity decreased by 33.5%.Furthermore,RCAC retained the early strength characteristics of coral concrete,with compressive strength and flexural strength exhibiting a notable increase as the water-cement ratio decreased.Under identical conditions,the compressive strength and flexural strength of RCAC were 12.7% and 2.5% higher than coral concrete's,respectively,with porosity correspondingly reduced from 3.13% to 5.11%.This enhancement could be attributed to the new mortar filling the recycled coral aggregate.Scanning electron microscopy(SEM)analysis revealed three distinct interface transition zones within RCAC,with the‘new mortar-old mortar’interface identified as the weakest.The above findings provided a reference for the sustainable use of coral concrete in constructing offshore islands.
基金supported by Science and Technology Project of China Southern Power Grid Company(036000KK52222007(GDKJXM20222121)).
文摘As renewable energy penetration continues to rise,enhancing power system flexibility has become a critical requirement.Photovoltaic–storage–charging stations(PSCSs)are key components for enhancing local regulation capability and promoting renewable integration.However,evaluating the adjustable capability of such hybrid stations while considering security constraints remains a major challenge.This paper first analyzes the adjustable capabilities of all the resources within such a station based on the power-energy boundary(PEB)model.Then,an optimal formulation is proposed to obtain the adjusted parameters of the aggregate feasible region(AFR)model,which embeds low-dimensional linear models within high-dimensional linear models to improve the accuracy.To solve this formulation,it is transformed using duality theory and an alternating optimization algorithm is designed to obtain the solution.Finally,a multi-station adjustable capability aggregation method considering security constraints is introduced.Simulation results verify that the proposed method effectively reduces infeasible regions and improves smoothness of aggregated boundaries,providing an accurate and practical tool for flexibility evaluation in PSCSs and offering guidance for aggregators and system planners.
