The confidentiality of pseudonymous authentication and secure data transmission is essential for the protection of information and mitigating risks posed by compromised vehicles.The Internet of Vehicles has meaningful...The confidentiality of pseudonymous authentication and secure data transmission is essential for the protection of information and mitigating risks posed by compromised vehicles.The Internet of Vehicles has meaningful applications,enabling connected and autonomous vehicles to interact with infrastructure,sensors,computing nodes,humans,and fellow vehicles.Vehicular hoc networks play an essential role in enhancing driving efficiency and safety by reducing traffic congestion while adhering to cryptographic security standards.This paper introduces a privacy-preserving Vehicle-to-Infrastructure authentication,utilizing encryption and the Moore curve.The proposed approach enables a vehicle to deduce the planned itinerary of Roadside Units(RSUs)before embarking on a journey.Crucially,the Certification Authority remains unaware of the specific route design,ensuring privacy.The method involves transforming all Roadside Units(RSUs)in a region into a vector,allowing for instant authentication of a vehicle’s route using RSU information.Real-world performance evaluations affirm the effectiveness of the proposed model.展开更多
In industrial areas, tree leaves contaminated by metals and metalloids could constitute a secondary source of pollutants. In the present study, water extraction kinetics of inorganic elements （IE： Pb, Zn, Cd, As, Fe...In industrial areas, tree leaves contaminated by metals and metalloids could constitute a secondary source of pollutants. In the present study, water extraction kinetics of inorganic elements （IE： Pb, Zn, Cd, As, Fe and Mn）, dissolved organic carbon, pH and biological activity were studied for industrial contaminated poplar leaves. Moreover, the distribution of the IE through the size fractions of the associated top soil was measured. High quantities ofMn, Zn and As and polysaccharides were released in the solution from the strongly contaminated leaves. The kinetic of release varied with time and metal type. The solution pH decreased while dissolved organic contents increased with time after 30 days. Therefore, these contaminated leaves could constitute a source of more available organic metals and metalloids than the initial inorganic process particles. However, the distribution of the IE through the size fractions of the top soil suggested that a great part of the released IE was adsorbed, reducing in consequence their transfers and bioavailability. It＇s concluded that mobility/boioavailability and speciation of metals and metalloids released from the decomposition of polluted tree leaves depends on soil characteristics, pollutant type and litter composition, with consequences for environmental risk assessment.展开更多
At the global scale,foliar metal transfer occurs for consumed vegetables cultivated in numerous urban or industrial areas with a polluted atmosphere.However,the kinetics of metal uptake,translocation and involved phyt...At the global scale,foliar metal transfer occurs for consumed vegetables cultivated in numerous urban or industrial areas with a polluted atmosphere.However,the kinetics of metal uptake,translocation and involved phytotoxicity was never jointly studied with vegetables exposed to micronic and sub-micronic particles(PM).Different leafy vegetables(lettuces and cabbages)cultivated in RHIZOtest?devices were,therefore,exposed in a greenhouse for 5,10 and 15 days to various Pb O PM doses.The kinetics of transfer and phytotoxicity was assessed in relation to lead concentration and exposure duration.A significant Pb accumulation in leaves(up to 7392 mg/kg dry weight(DW)in lettuce)with translocation to roots was observed.Lead foliar exposure resulted in significant phytotoxicity,lipid composition change,a decrease of plant shoot growth(up to 68.2%in lettuce)and net photosynthesis(up to 58%in lettuce).The phytotoxicity results indicated plant adaptation to Pb and a higher sensitivity of lettuce in comparison with cabbage.Air quality needs,therefore,to be considered for the health and quality of vegetables grown in polluted areas,such as certain megacities(in China,Pakistan,Europe,etc.)and furthermore,to assess the health risks associated with their consumption.展开更多
This study aims at evaluating the potential suitability of Tetouan and Meknes (central Morocco) clay material as raw materials in various ceramic applications by investigating their textural, chemical, thermal and fir...This study aims at evaluating the potential suitability of Tetouan and Meknes (central Morocco) clay material as raw materials in various ceramic applications by investigating their textural, chemical, thermal and firing characteristics. Textural properties were identified by specific surface area, cation exchange capacity (CEC) and bulk density (ρs). Chemical and thermal properties were assessed using XRF and TG/DTA techniques, respectively. Firing characteristics at temperatures from 800℃ to 1100℃ were determined by linear firing shrinkage, loss on weight and water absorption capacity. The Meknes clays are characterised by medium cation exchange capacity (CEC) and specific surface area (SSA) values due to their moderate smectite content. The Tetouan clays have medium to low CEC and medium SSA values. The main oxides in the clayey samples are SiO2 (35 - 54.3 wt%), Al2O3 (20.6 - 43.9 wt%), and Fe2O3 (9.7 - 22.4 wt%). The amount of CaO in Meknes clays ranges from 8 to 12 wt%, whereas CaO is only present in some Tetouan clay (TE4, TE7, TN4 and TN5). A significant densification of ceramic behaviour could be noticed for most of Tetouan clays at firing temperatures above 1000℃. Meknes clays show earlier densification from 800℃. The chemical, textural and ceramic properties of Tetouan and Meknes clays indicate their suitability as raw materials for the production of structural ceramics. The high amount of Fe2O3 in all clays makes them inappropriate in fine ceramics.展开更多
This paper describes recent levels of surfactants measured in a coastal lagoon ecosystem highly stressed by human activites: the Orbetello lagoon (Southern Tuscany, Italy, Ramsar Site IT008). Significance of differenc...This paper describes recent levels of surfactants measured in a coastal lagoon ecosystem highly stressed by human activites: the Orbetello lagoon (Southern Tuscany, Italy, Ramsar Site IT008). Significance of difference among concentrations measured before and after summertime are explored in order to evaluate effects related to tourism exploitation. Among surfactants, methylene blue active anionic substances (MBAS) are selected as tracers for untreated discharges originated by domestic and urban activities. Water samplings were performed in 2011 following a randomly replicated nested logic model (n = 144). MBAS mean level of 0.070 mg.L–1 (–1) and 0.530 mg.L–1 (–1) are respectively recorded in June and October evidencing a significant increase after the touristic season. Possible MBAS concentration phenomena could be induced by different evaportaton rates among sampling stations and between winter and summer seasons and were evaluated, in this study, using water salinity as possible factor affecting samples segregations. Results evidence that differences of MBAS levels related to evaporation rates are trascurabile if compared to the variability induced by the presence of not-collected wastewater hot-spot pollution sources located closed around the urban settlement and along sandbars. Measured levels of surfactants could act negatively on living organisms both animals and plants contributing to affect Orbetello lagoon biodiversity. In this ecosystem, after the complete reorganization of urban wastewater treatment plants occured in 2008, further management actions should be focalized on reducing untreated sources of MBAS.展开更多
The main cash crop in Togo is cotton, with about 70% of agricultural exports. This crop is very dependent on the use of chemical inputs, in particular pesticides. Pesticides used in cotton farming in Togo include orga...The main cash crop in Togo is cotton, with about 70% of agricultural exports. This crop is very dependent on the use of chemical inputs, in particular pesticides. Pesticides used in cotton farming in Togo include organochlorines, triazines, organophosphates and pyrethroids. We conducted a study on the impact of these pesticide use, in particular organochlorines and triazines, on cotton farming soils. We chose the Plateaux region (southern Togo) as the study area because of its high cotton production. Analysis was carried out on crop soil samples at the 0 - 20 cm horizon. Several pesticide residues were found: simazine (0.051 to 0.103 μg/Kg soil);atrazine (0.149 to 0.197 μg/Kg soil);lindane (0.259 to 0.672 μg/Kg soil);β-endosulfan (1.37 to 5.727 μg/Kg soil);dieldrin (0.063 to 1.16 μg/Kg soil);endrin (0.512 μg/Kg soil), Heptachlor (0.489 to 1.243 μg/Kg soil);Heptachlor epoxide (0.928 to 1.633 μg/Kg soil);[2,4'DDT] (0.257 μg/Kg soil);[4,4'DDE] (0.262 μg/Kg soil). These results show pesticide contamination of cotton farming soils.展开更多
The Soil and Water Assessment Tool(SWAT)model was used to assess the impacts of different land use scenarios on hydrological processes in the Fuhe watershed in Poyang Lake Basin,East China.A total of 12 model paramete...The Soil and Water Assessment Tool(SWAT)model was used to assess the impacts of different land use scenarios on hydrological processes in the Fuhe watershed in Poyang Lake Basin,East China.A total of 12 model parameters were calibrated with observed monthly runoff data for 1982-1988 and validated for 1991-1998 for baseline conditions.The baseline test results of R2 and Nash-Sutcliffe model efficiency(NSE)values ranged between 0.88 and 0.94 across the calibration and validation periods,indicating that SWAT accurately replicated the Fuhe watershed streamflow.Several different land use scenarios were then simulated with the model,focusing on the impacts of land use change on the hydrology of the watershed.The results of hypothetical scenario simulations revealed that surface runoff declined while groundwater recharge and evapotranspiration(ET)increased,as forest land,agriculture land and/or grassland areas increased,as well as when paddy field and urban areas decreased.These results further showed that forest land has a higher capacity to conserve the water as compared to pasture land.The results of the real scenario simulations revealed that urbanization is the strongest contributor to changes in surface runoff,water yield,and ET.Urbanization can be considered as a potential major environmental stressor controlling hydrological components.展开更多
Two cornborer species, Ostrinia furnacalis （Lepidoptera： Crambidae） and O. nubilalis, are major corn pests in Asia and Europe, respectively. In both continents, the larval endoparasitoid Macrocentrus cingulum （Hym...Two cornborer species, Ostrinia furnacalis （Lepidoptera： Crambidae） and O. nubilalis, are major corn pests in Asia and Europe, respectively. In both continents, the larval endoparasitoid Macrocentrus cingulum （Hymenoptera： Braconidae） develops on another, closely related stemborer, O. scapulalis, which feeds on mugwort and other dicotyledons. M. cingulum also emerges from O. furnacalis in Asia and （9. nubilalis in North America, but not from O. nubilalis in Europe. We assessed the ability of three populations of each of the three Ostrinia species to encapsulate foreign bodies of a size similar to that of a M. cingulum egg. We conclude that variations in encapsulation ability alone cannot account for the differences observed in the field between parasite emergence rates in these different host species and geographic areas.展开更多
Aims One critical challenge for plants is to maintain an adequate nutrient supply under fluctuating environmental conditions.This is particularly true for epiphytic species that have limited or no access to the pedosp...Aims One critical challenge for plants is to maintain an adequate nutrient supply under fluctuating environmental conditions.This is particularly true for epiphytic species that have limited or no access to the pedosphere and often live in harsh climates.Bromeliads have evolved key innovations such as epiphytism,water-absorbing leaf trichomes,tank habit and Crassulacean acid metabolism(CAM)photosynthesis that enable them to survive under various environmental conditions.Bromeliads encompass diverse ecological types that live on different substrates(they can be terrestrial,epilithic or epiphytic)and vary in their ability to retain water(they can be tank-forming or tankless)and photosynthetic pathway(i.e.C3 or CAM).In this review,we outline the nutritional modes and specializations that enable bromeliads to thrive in a wide range of nutrient-poor(mostly nitrogen-depleted)environments.Important FindingsBromeliads have evolved a great diversity of morphologies and functional adaptations leading to the existence of numerous nutritional modes.Focusing on species that have absorptive foliar trichomes,we review evidence that bromeliads have evolved multi-faceted nutritional strategies to respond to fluctuations in the supply of natural nitrogen(N).These plants have developed mutualistic associations with many different and functionally diverse terrestrial and aquatic microorganisms and metazoans that contribute substantially to their mineral nutrition and,thus,their fitness and survival.Bacterial and fungal microbiota-assisted N provisioning,protocarnivory,digestive mutualisms and myrmecotrophic pathways are the main strategies used by bromeliads to acquire nitrogen.The combination of different nutritional pathways in bromeliads represents an important adaptation enabling them to exploit nutrient-poor habitats.Nonetheless,as has been shown for several other vascular plants,multiple partners are involved in nutrient acquisition indicating that there have been convergent adaptations to nutrient scarcity.Finally,we point out some gaps in the current knowledge of bromeliad nutrition that offer fascinating research opportunities.展开更多
Supercolonies of the red fire ant Solenopsis saevissima （Smith） develop in disturbed environments and likely alter the ant community in the native range of the species. For example, in French Guiana only 8 ant speci...Supercolonies of the red fire ant Solenopsis saevissima （Smith） develop in disturbed environments and likely alter the ant community in the native range of the species. For example, in French Guiana only 8 ant species were repeatedly noted as nesting in close vicinity to its mounds. Here, we verified if a shared set of biological, ecological, and behavioral traits might explain how these 8 species are able to nest in the presence of S. saevissima. We did not find this to be the case. We did find, however, that all of them are able to live in disturbed habitats. It is likely that over the course of evolution each of these species acquired the capacity to live syntopically with S. saevissima through its own set of traits, where colony size （4 species develop large colonies）, cuticular compounds which do not trigger aggressiveness （6 species） and submissive behaviors （4 species） complement each other.展开更多
In this study, conducted in French Guiana, a part of the native range of the fire ant Solenopsis saevissima, we compared the cuticular hydrocarbon profiles of media workers with previous results based on intraspecific...In this study, conducted in French Guiana, a part of the native range of the fire ant Solenopsis saevissima, we compared the cuticular hydrocarbon profiles of media workers with previous results based on intraspecific aggressiveness tests. We noted a strong congruence between the two studies permitting us to delimit 2 supercolonies extending over large distances （up to 54 kin）, a phenomenon known as unicoloniality. Solenopsis geminata workers, taken as an out-group for cluster analyses, have a very different cuticular hydrocarbon profile. Because S. saevissima has been reported outside its native range, our conclusion is that this species has the potential to become invasive because unicoloniality （i.e., the main attribute for ants to become invasive） was shown at least for the Guianese population.展开更多
文摘The confidentiality of pseudonymous authentication and secure data transmission is essential for the protection of information and mitigating risks posed by compromised vehicles.The Internet of Vehicles has meaningful applications,enabling connected and autonomous vehicles to interact with infrastructure,sensors,computing nodes,humans,and fellow vehicles.Vehicular hoc networks play an essential role in enhancing driving efficiency and safety by reducing traffic congestion while adhering to cryptographic security standards.This paper introduces a privacy-preserving Vehicle-to-Infrastructure authentication,utilizing encryption and the Moore curve.The proposed approach enables a vehicle to deduce the planned itinerary of Roadside Units(RSUs)before embarking on a journey.Crucially,the Certification Authority remains unaware of the specific route design,ensuring privacy.The method involves transforming all Roadside Units(RSUs)in a region into a vector,allowing for instant authentication of a vehicle’s route using RSU information.Real-world performance evaluations affirm the effectiveness of the proposed model.
文摘In industrial areas, tree leaves contaminated by metals and metalloids could constitute a secondary source of pollutants. In the present study, water extraction kinetics of inorganic elements （IE： Pb, Zn, Cd, As, Fe and Mn）, dissolved organic carbon, pH and biological activity were studied for industrial contaminated poplar leaves. Moreover, the distribution of the IE through the size fractions of the associated top soil was measured. High quantities ofMn, Zn and As and polysaccharides were released in the solution from the strongly contaminated leaves. The kinetic of release varied with time and metal type. The solution pH decreased while dissolved organic contents increased with time after 30 days. Therefore, these contaminated leaves could constitute a source of more available organic metals and metalloids than the initial inorganic process particles. However, the distribution of the IE through the size fractions of the top soil suggested that a great part of the released IE was adsorbed, reducing in consequence their transfers and bioavailability. It＇s concluded that mobility/boioavailability and speciation of metals and metalloids released from the decomposition of polluted tree leaves depends on soil characteristics, pollutant type and litter composition, with consequences for environmental risk assessment.
基金financial support from Ademe(the French Agency of Sustainable Development and Energy)through the"DIMENSION"projectthe National Research Agency under reference ANR-12-0011-VBDUthe National Polytechnic Institute in Toulouse(INPT)
文摘At the global scale,foliar metal transfer occurs for consumed vegetables cultivated in numerous urban or industrial areas with a polluted atmosphere.However,the kinetics of metal uptake,translocation and involved phytotoxicity was never jointly studied with vegetables exposed to micronic and sub-micronic particles(PM).Different leafy vegetables(lettuces and cabbages)cultivated in RHIZOtest?devices were,therefore,exposed in a greenhouse for 5,10 and 15 days to various Pb O PM doses.The kinetics of transfer and phytotoxicity was assessed in relation to lead concentration and exposure duration.A significant Pb accumulation in leaves(up to 7392 mg/kg dry weight(DW)in lettuce)with translocation to roots was observed.Lead foliar exposure resulted in significant phytotoxicity,lipid composition change,a decrease of plant shoot growth(up to 68.2%in lettuce)and net photosynthesis(up to 58%in lettuce).The phytotoxicity results indicated plant adaptation to Pb and a higher sensitivity of lettuce in comparison with cabbage.Air quality needs,therefore,to be considered for the health and quality of vegetables grown in polluted areas,such as certain megacities(in China,Pakistan,Europe,etc.)and furthermore,to assess the health risks associated with their consumption.
文摘This study aims at evaluating the potential suitability of Tetouan and Meknes (central Morocco) clay material as raw materials in various ceramic applications by investigating their textural, chemical, thermal and firing characteristics. Textural properties were identified by specific surface area, cation exchange capacity (CEC) and bulk density (ρs). Chemical and thermal properties were assessed using XRF and TG/DTA techniques, respectively. Firing characteristics at temperatures from 800℃ to 1100℃ were determined by linear firing shrinkage, loss on weight and water absorption capacity. The Meknes clays are characterised by medium cation exchange capacity (CEC) and specific surface area (SSA) values due to their moderate smectite content. The Tetouan clays have medium to low CEC and medium SSA values. The main oxides in the clayey samples are SiO2 (35 - 54.3 wt%), Al2O3 (20.6 - 43.9 wt%), and Fe2O3 (9.7 - 22.4 wt%). The amount of CaO in Meknes clays ranges from 8 to 12 wt%, whereas CaO is only present in some Tetouan clay (TE4, TE7, TN4 and TN5). A significant densification of ceramic behaviour could be noticed for most of Tetouan clays at firing temperatures above 1000℃. Meknes clays show earlier densification from 800℃. The chemical, textural and ceramic properties of Tetouan and Meknes clays indicate their suitability as raw materials for the production of structural ceramics. The high amount of Fe2O3 in all clays makes them inappropriate in fine ceramics.
文摘This paper describes recent levels of surfactants measured in a coastal lagoon ecosystem highly stressed by human activites: the Orbetello lagoon (Southern Tuscany, Italy, Ramsar Site IT008). Significance of difference among concentrations measured before and after summertime are explored in order to evaluate effects related to tourism exploitation. Among surfactants, methylene blue active anionic substances (MBAS) are selected as tracers for untreated discharges originated by domestic and urban activities. Water samplings were performed in 2011 following a randomly replicated nested logic model (n = 144). MBAS mean level of 0.070 mg.L–1 (–1) and 0.530 mg.L–1 (–1) are respectively recorded in June and October evidencing a significant increase after the touristic season. Possible MBAS concentration phenomena could be induced by different evaportaton rates among sampling stations and between winter and summer seasons and were evaluated, in this study, using water salinity as possible factor affecting samples segregations. Results evidence that differences of MBAS levels related to evaporation rates are trascurabile if compared to the variability induced by the presence of not-collected wastewater hot-spot pollution sources located closed around the urban settlement and along sandbars. Measured levels of surfactants could act negatively on living organisms both animals and plants contributing to affect Orbetello lagoon biodiversity. In this ecosystem, after the complete reorganization of urban wastewater treatment plants occured in 2008, further management actions should be focalized on reducing untreated sources of MBAS.
文摘The main cash crop in Togo is cotton, with about 70% of agricultural exports. This crop is very dependent on the use of chemical inputs, in particular pesticides. Pesticides used in cotton farming in Togo include organochlorines, triazines, organophosphates and pyrethroids. We conducted a study on the impact of these pesticide use, in particular organochlorines and triazines, on cotton farming soils. We chose the Plateaux region (southern Togo) as the study area because of its high cotton production. Analysis was carried out on crop soil samples at the 0 - 20 cm horizon. Several pesticide residues were found: simazine (0.051 to 0.103 μg/Kg soil);atrazine (0.149 to 0.197 μg/Kg soil);lindane (0.259 to 0.672 μg/Kg soil);β-endosulfan (1.37 to 5.727 μg/Kg soil);dieldrin (0.063 to 1.16 μg/Kg soil);endrin (0.512 μg/Kg soil), Heptachlor (0.489 to 1.243 μg/Kg soil);Heptachlor epoxide (0.928 to 1.633 μg/Kg soil);[2,4'DDT] (0.257 μg/Kg soil);[4,4'DDE] (0.262 μg/Kg soil). These results show pesticide contamination of cotton farming soils.
基金This work was funded by the National Natural Science Foundation of China(41331174,41101415,41301366)Collaborative Innovation Center of Geospatial Technology,Collaborative Innovation Center for Major Ecological Security Issues of Jiangxi Province and Monitoring Implementation(JXS-EW-08)+2 种基金Special Fund by Surveying&Mapping and Geoinformation Research in the Public Interest(201512026),863 Program(2012AA12A304,2012AA12A306)Natural Science Foundation of Hubei Province of China(2015CFB331)Special funds of State Key Laboratory for equipment.Thanks to Jiangxi Provincial Institute of Water Science for providing partial data for this paper.
文摘The Soil and Water Assessment Tool(SWAT)model was used to assess the impacts of different land use scenarios on hydrological processes in the Fuhe watershed in Poyang Lake Basin,East China.A total of 12 model parameters were calibrated with observed monthly runoff data for 1982-1988 and validated for 1991-1998 for baseline conditions.The baseline test results of R2 and Nash-Sutcliffe model efficiency(NSE)values ranged between 0.88 and 0.94 across the calibration and validation periods,indicating that SWAT accurately replicated the Fuhe watershed streamflow.Several different land use scenarios were then simulated with the model,focusing on the impacts of land use change on the hydrology of the watershed.The results of hypothetical scenario simulations revealed that surface runoff declined while groundwater recharge and evapotranspiration(ET)increased,as forest land,agriculture land and/or grassland areas increased,as well as when paddy field and urban areas decreased.These results further showed that forest land has a higher capacity to conserve the water as compared to pasture land.The results of the real scenario simulations revealed that urbanization is the strongest contributor to changes in surface runoff,water yield,and ET.Urbanization can be considered as a potential major environmental stressor controlling hydrological components.
文摘Two cornborer species, Ostrinia furnacalis （Lepidoptera： Crambidae） and O. nubilalis, are major corn pests in Asia and Europe, respectively. In both continents, the larval endoparasitoid Macrocentrus cingulum （Hymenoptera： Braconidae） develops on another, closely related stemborer, O. scapulalis, which feeds on mugwort and other dicotyledons. M. cingulum also emerges from O. furnacalis in Asia and （9. nubilalis in North America, but not from O. nubilalis in Europe. We assessed the ability of three populations of each of the three Ostrinia species to encapsulate foreign bodies of a size similar to that of a M. cingulum egg. We conclude that variations in encapsulation ability alone cannot account for the differences observed in the field between parasite emergence rates in these different host species and geographic areas.
基金support from the Programme Convergence 2007-2013,Région Guyane from the European community(BREGA,ref.32080)an‘Investissement d’Avenir’grant managed by Agence Nationale de la Recherche(CEBA,ref.ANR-10-LABX-0025).
文摘Aims One critical challenge for plants is to maintain an adequate nutrient supply under fluctuating environmental conditions.This is particularly true for epiphytic species that have limited or no access to the pedosphere and often live in harsh climates.Bromeliads have evolved key innovations such as epiphytism,water-absorbing leaf trichomes,tank habit and Crassulacean acid metabolism(CAM)photosynthesis that enable them to survive under various environmental conditions.Bromeliads encompass diverse ecological types that live on different substrates(they can be terrestrial,epilithic or epiphytic)and vary in their ability to retain water(they can be tank-forming or tankless)and photosynthetic pathway(i.e.C3 or CAM).In this review,we outline the nutritional modes and specializations that enable bromeliads to thrive in a wide range of nutrient-poor(mostly nitrogen-depleted)environments.Important FindingsBromeliads have evolved a great diversity of morphologies and functional adaptations leading to the existence of numerous nutritional modes.Focusing on species that have absorptive foliar trichomes,we review evidence that bromeliads have evolved multi-faceted nutritional strategies to respond to fluctuations in the supply of natural nitrogen(N).These plants have developed mutualistic associations with many different and functionally diverse terrestrial and aquatic microorganisms and metazoans that contribute substantially to their mineral nutrition and,thus,their fitness and survival.Bacterial and fungal microbiota-assisted N provisioning,protocarnivory,digestive mutualisms and myrmecotrophic pathways are the main strategies used by bromeliads to acquire nitrogen.The combination of different nutritional pathways in bromeliads represents an important adaptation enabling them to exploit nutrient-poor habitats.Nonetheless,as has been shown for several other vascular plants,multiple partners are involved in nutrient acquisition indicating that there have been convergent adaptations to nutrient scarcity.Finally,we point out some gaps in the current knowledge of bromeliad nutrition that offer fascinating research opportunities.
文摘Supercolonies of the red fire ant Solenopsis saevissima （Smith） develop in disturbed environments and likely alter the ant community in the native range of the species. For example, in French Guiana only 8 ant species were repeatedly noted as nesting in close vicinity to its mounds. Here, we verified if a shared set of biological, ecological, and behavioral traits might explain how these 8 species are able to nest in the presence of S. saevissima. We did not find this to be the case. We did find, however, that all of them are able to live in disturbed habitats. It is likely that over the course of evolution each of these species acquired the capacity to live syntopically with S. saevissima through its own set of traits, where colony size （4 species develop large colonies）, cuticular compounds which do not trigger aggressiveness （6 species） and submissive behaviors （4 species） complement each other.
文摘In this study, conducted in French Guiana, a part of the native range of the fire ant Solenopsis saevissima, we compared the cuticular hydrocarbon profiles of media workers with previous results based on intraspecific aggressiveness tests. We noted a strong congruence between the two studies permitting us to delimit 2 supercolonies extending over large distances （up to 54 kin）, a phenomenon known as unicoloniality. Solenopsis geminata workers, taken as an out-group for cluster analyses, have a very different cuticular hydrocarbon profile. Because S. saevissima has been reported outside its native range, our conclusion is that this species has the potential to become invasive because unicoloniality （i.e., the main attribute for ants to become invasive） was shown at least for the Guianese population.
