The occurrence, distribution, and rapid molecular detection technology of Heterodera zeae Koshy et al. 1971, have been reported in China. We explored the biological characteristics of H. zeae sampled in Henan Province...The occurrence, distribution, and rapid molecular detection technology of Heterodera zeae Koshy et al. 1971, have been reported in China. We explored the biological characteristics of H. zeae sampled in Henan Province, China to understand its interaction with plants. Cysts and second-stage juveniles(J2s) were identified under an optical and scanning electron microscope, internal transcribed spacer(ITS) phylogenetic tree, and sequence characterized amplified region(SCAR)-PCR analyses. The optimum hatching temperatures of H. zeae were 30°C and 28°C, with cumulative hatching rates of 16.5 and 16.1%, respectively, at 30 days post-hatching(dph). The hatching rate of H. zeae eggs was improved by 20-and 50-time maize soil leachate and root juice, and 10-time root exudates. The hatching rate in 10-time root exudates was the highest(25.9%). The 10-time root exudates of maize and millet produced the highest hatching rate at 30 dph(25.9 and 22.9%, respectively), followed by wheat(19.9%), barley(18.3%), and rice(17.6%). Heterodera zeae developed faster in maize than in other crops. Fourth-stage juveniles(J4s) were detected in maize roots 8 days post-inoculation(dpi) at 28°C but not in other crops. Combined with hatching tests, the Huang–Huai–Hai summer maize region and the south and central-southwest mountainous maize areas are highly suitable for H. zeae in China. This is the first systematically study of the hatching and infection characteristics on different plant hosts of corn cyst nematode H. zeae in temperate regions. This study laid a theoretical foundation for the rapid spread and high environmental adaptability of corn cyst nematode.展开更多
The urgent demand for high-energy-density storage systems evokes the research upsurge on the alkali metal batteries with high theoretical capacities.However,the utilization of alkali metal anodes,including Li,Na,and K...The urgent demand for high-energy-density storage systems evokes the research upsurge on the alkali metal batteries with high theoretical capacities.However,the utilization of alkali metal anodes,including Li,Na,and K,is significantly hindered by notorious dendrite growth,undesirable corrosion,and unstable solid electrolyte interface.In order to resolve these issues,the carbon materials for the rational design of current collector/host that can regulate the plating/stripping behavior of alkali metal have been exploited.These carbon-based current collectors/hosts are featured with many pivotal advantages,including mechanical integrity to accommodate the volume change,superior electronic/ionic conductivity,large available surface area,and rich functionalization chemistries to increase the affinity to alkali metal.In this review,the recent progress on various dimensional carbon-based current collectors/hosts with different chemical components in stabilizing the alkali metal anodes through the regulation of initial deposition and subsequent growth behavior during plating/stripping process is provided.The nanostructured carbon scaffolds with self-affinity to alkali metals,as well as the carbon frameworks with internal/external affinitive sites to alkali metals,catalogued by various dimensions,are discussed in this review.Therefore,these appealing strategies based on the carbon-based current collectors/hosts can provide a paradigm for the realization of high-energy-density alkali metal batteries.展开更多
Lithium(Li) metal anode has received extensive attentions due to its ultrahigh theoretical capacity and the most negative electrode potential. However, dendrite growth severely impedes the practical applications of th...Lithium(Li) metal anode has received extensive attentions due to its ultrahigh theoretical capacity and the most negative electrode potential. However, dendrite growth severely impedes the practical applications of the Li metal anode in rechargeable batteries. In this contribution, a mesoporous graphene with a high specific surface area was synthesized to host the Li metal anode. The mesoporous graphene host(MGH) has a high specific surface area(2090 m^2/g), which affords free space and an interconnected conductive pathway for Li plating and stripping, thus alleviating the volume variation and reducing the generation of dead Li during repeated cycles. More importantly, the high specific surface area of MGH efficiently reduces the local current density of the electrode, which favors a uniform Li nucleation and plating behavior, rendering a dendritefree deposition morphology at a low overpotential. These factors synergistically boost the Li utilization(90.1% vs. 70.1% for Cu foil) and life span(150 cycles vs. 100 cycles for Cu foil) with a low polarization of MGH electrode at an ultrahigh current of 15.0 mA/cm^2. The as-prepared MGH can provide fresh insights into the electrode design of the Li metal anode operating at high rates.展开更多
Lithium-sulfur batteries(LSBs)are one of the most promising energy storage devices because of their high theoretical energy density;however,inherent issues including poor electrical conductivity and severe dissolution...Lithium-sulfur batteries(LSBs)are one of the most promising energy storage devices because of their high theoretical energy density;however,inherent issues including poor electrical conductivity and severe dissolution of S and its discharged products hinder their practical applications.MXenes have metallic conductivity,ultra-thin two-dimensional(2D)structures,rich surface functional groups,and macrostructural adjustability and have been widely used to design advanced sulfur hosts.3D network structures assembled by 2D MXene nanosheets have shown superior performance for improving reaction kinetics,accommodating and dispersing sulfur at the micro-/nanoscale,and capturing polysulfides due to their porous interconnected structure.Herein,the applications of MXene architectures related to 2D layered structures,3D multilayered structures,and 3D spherical structures as sulfur hosts are reviewed.The structure-performance relationship,challenges for current designs,and opportunities for future 3D architectures for LSBs are also analyzed.展开更多
With its high theoretical capacity,lithium(Li)metal is recognized as the most potential anode for realizing a high-performance energy storage system.A series of questions(severe safety hazard,low Coulombic efficiency,...With its high theoretical capacity,lithium(Li)metal is recognized as the most potential anode for realizing a high-performance energy storage system.A series of questions(severe safety hazard,low Coulombic efficiency,short lifetime,etc.)induced by uncontrollable dendrites growth,unstable solid electrolyte interface layer,and large volume change,make practical application of Li-metal anodes still a threshold.Due to their highly appealing properties,carbon-based materials as hosts to composite with Li metal have been passionately investigated for improving the performance of Li-metal batteries.This review displays an overview of the critical role of carbon-based hosts for improving the comprehensive performance of Li-metal anodes.Based on correlated mainstream models,the main failure mechanism of Li-metal anodes is introduced.The advantages and strategies of carbon-based hosts to address the corresponding challenges are generalized.The unique function,existing limitation,and recent research progress of key carbon-based host materials for Li-metal anodes are reviewed.Finally,a conclusion and an outlook for future research of carbon-based hosts are presented.This review is dedicated to summarizing the advances of carbon-based materials hosts in recent years and providing a reference for the further development of carbonbased hosts for advanced Li-metal anodes.展开更多
Background: Cuscuta spp. known as dodders, have been used as traditional medicines in eastern and southern Asian countries for many disorders such as gastrointestinal, respiratory, endocrine, skin and neurological dis...Background: Cuscuta spp. known as dodders, have been used as traditional medicines in eastern and southern Asian countries for many disorders such as gastrointestinal, respiratory, endocrine, skin and neurological diseases (Drug of mania). Flavonoids are the main biologically active constituents in Cuscuta genus especially in C. chinensis. Our aim in this study was to identify and discriminate between C. chinensis samples which were collected from different hosts, by using the pattern recognition aided fingerprint analysis and comparison of the content of four major flavonoids (hyperoside, rutin, isorhamnetin, kaempferol). Material and methods: Samples were collected from nine different plants in the same time and place, dried, grinded and extracted with methanol (80%) by repeated maceration. Extractions were evaluated by high performance liquid chromatography analysis and fingerprinting. Results: Beside chromatographic fingerprint using similarity index, we compared the content of 4 major flavonoids (hyperoside, rutin, isorhamnetin, kaempferol) of C. chinensis samples on different hosts. Coclusion: The results showed that there were significant differences between the content of four major flavonoids of nine C. chinensis samples, but chromatographic fingerprint by similarity index of more than 0.88, showed that the sample consistency was similar. So, it was suggested that combination of chromatographic fingerprint and the content determination of major flavonoids could be used to evaluate the quality control of C. chinensis from different hosts.展开更多
Objective:To evaluate the predatory potential of the Odonata nymph on freshwater snails that serve as intermediate hosts for Schistosoma species(Bulinus truncatus and Biomphalaria alexandrina).Methods:Observations on ...Objective:To evaluate the predatory potential of the Odonata nymph on freshwater snails that serve as intermediate hosts for Schistosoma species(Bulinus truncatus and Biomphalaria alexandrina).Methods:Observations on the searching,attacking and devouring of the two snail types with series of laboratory-based predation experiments,whose aims were to determine daily predation rate,differential predation,prey preference considering small-,mediumand large-sized snails were conducted.Results:Laboratory evaluation revealed that,the Odonata nymph could kill and consume the two intermediate hosts.The number of snails consumed differed according to the snail type,size and density.The times taken for searching and handling times were dependent on the snail size,type and satiation of the predator.The predation rate varied also with respect to snail type,size and density.This study also evaluated that Odonata nymphs consumed more Bulinus truncatus than Biomphalaria alexandrina per unit time,and that there may be a preference for smaller than larger snails.Conclusions:According to our observation,the predator,Hemianax ephippiger nymph may be a suitable biocontrol agent in connection with Schistosoma intermediate hosts.展开更多
The World Engineers’ Convention2004(WEC2004)was held onNovember 2-6,2004 in Shanghai,China. The motto of the conventionis“Engineers Shape the SustainableFuture.”It advocates that engineersshould take the task of ma...The World Engineers’ Convention2004(WEC2004)was held onNovember 2-6,2004 in Shanghai,China. The motto of the conventionis“Engineers Shape the SustainableFuture.”It advocates that engineersshould take the task of makingpeople’s life better and commit tocreating a new world.Engineers should be well awareof their responsibilities:developingnew technologies and making good展开更多
Interoperability of symmetric 10G-EPON products was demonstrated successfully in Shanghai, China in April 2010. Interoperability among products was successfully demonstrated by four vendors: Broadcom, PMC-Sierra Opu...Interoperability of symmetric 10G-EPON products was demonstrated successfully in Shanghai, China in April 2010. Interoperability among products was successfully demonstrated by four vendors: Broadcom, PMC-Sierra Opulan and ZTE. Each vendor supplied an OLT and a variety of ONUs (supporting both 1G-EPON and symmetric 10G-EPON), connected in a multi-vendor展开更多
With constant economic development and continuous improvement of living standards in Northeast China,rural tourism,as a new type of tourism,is increasingly favored. From the perspective of symbolic interaction theory,...With constant economic development and continuous improvement of living standards in Northeast China,rural tourism,as a new type of tourism,is increasingly favored. From the perspective of symbolic interaction theory,taking the current situation of rural tourism in Northeast China as an example,this paper explained the semiotic significance between hosts and guests in rural tourism. It established the evaluation indicators for authentic symbolic perception of rural tourism. Also,combined with the theories of sociology and anthropology,it studied the interaction between hosts and tourists of rural tourism in Northeast China.展开更多
In Brazil,schistosomiasis occurrence is related to the presence of the etiological agent Schistosoma mansoni.The presence of mollusks for Biomphalaria genus is a necessary condition for development of the parasite cyc...In Brazil,schistosomiasis occurrence is related to the presence of the etiological agent Schistosoma mansoni.The presence of mollusks for Biomphalaria genus is a necessary condition for development of the parasite cycle.In Parástate,the species B.schrammi,B.kuhniana,B.straminea and B.glabrata have already been identified,with reports of the last two occurring in Belém.The aim of this study was to determine the spatial distribution of Biomphalaria species in Belém,Pará,Brazil,identifying risk areas for schistosomiasis transmission.Biannual malacological surveys were carried out between September 2013 and October 2017 in 35 neighborhoods of Belém.The collection points were georeferenced using a Global Positioning System(GPS)receiver and the Kernel Density Estimation(KDE)was used to the spatial analysis.The mollusks,after measurement,were exposed to light to verify the presence of S.mansoni cercariae.Subsequently,mollusks were sacrificed and fixed for dissection and morphological identification of species.The surveys resulted in a total of 10,803 mollusks collected,of which 9,367(86.70%)specimens were examined.Among the analyzed mollusks,5,820(62.14%)were identified as B.glabrata and 3,547(37.86%)as B.straminea.The presence of the parasite was observed in 208(2.22%)specimens,all B.glabrata.Positive mollusks were found in six neighborhoods:Guamá(51 mollusks/24.5%),Sacramenta(47 mollusks/22.6%),Telégrafo(47 mollusks/22.6%),Terra Firme(36 mollusks/17.3%),Condor(20 mollusks/9.6%)and Barreiro(7 mollusks/3.4%).This study confirms that B.glabrata species actively participates as intermediate host in the disease maintenance in Belém.The KDE allowed to analyze the spatial distribution of collection sites and consequently to determine possible risk areas of schistosomiasis transmission in Belem.The development of maps identifying sites with schistosomiasis positive snails may support efforts of this municipality by directing activities related to endemic disease control.展开更多
基金This study was financially supported by the National Natural Science Foundation of China(31801717)the Major Science and Technology Projects in Henan Province,China(221100110300)+2 种基金the Special Fund for Young Talents in Henan Agricultural University,China(30500663)the Opening Foundation of the National Key Laboratory of Crop Science on Wheat and Maize,China(SKL2021KF06)the HAU grant for Collaborative Crop Science Research,China(CCSR2022-1)。
文摘The occurrence, distribution, and rapid molecular detection technology of Heterodera zeae Koshy et al. 1971, have been reported in China. We explored the biological characteristics of H. zeae sampled in Henan Province, China to understand its interaction with plants. Cysts and second-stage juveniles(J2s) were identified under an optical and scanning electron microscope, internal transcribed spacer(ITS) phylogenetic tree, and sequence characterized amplified region(SCAR)-PCR analyses. The optimum hatching temperatures of H. zeae were 30°C and 28°C, with cumulative hatching rates of 16.5 and 16.1%, respectively, at 30 days post-hatching(dph). The hatching rate of H. zeae eggs was improved by 20-and 50-time maize soil leachate and root juice, and 10-time root exudates. The hatching rate in 10-time root exudates was the highest(25.9%). The 10-time root exudates of maize and millet produced the highest hatching rate at 30 dph(25.9 and 22.9%, respectively), followed by wheat(19.9%), barley(18.3%), and rice(17.6%). Heterodera zeae developed faster in maize than in other crops. Fourth-stage juveniles(J4s) were detected in maize roots 8 days post-inoculation(dpi) at 28°C but not in other crops. Combined with hatching tests, the Huang–Huai–Hai summer maize region and the south and central-southwest mountainous maize areas are highly suitable for H. zeae in China. This is the first systematically study of the hatching and infection characteristics on different plant hosts of corn cyst nematode H. zeae in temperate regions. This study laid a theoretical foundation for the rapid spread and high environmental adaptability of corn cyst nematode.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(NRF-2020R1A3B2079803)Republic of Korea and SKKU Research Fellowship Program of Sungkyunkwan University,2021.
文摘The urgent demand for high-energy-density storage systems evokes the research upsurge on the alkali metal batteries with high theoretical capacities.However,the utilization of alkali metal anodes,including Li,Na,and K,is significantly hindered by notorious dendrite growth,undesirable corrosion,and unstable solid electrolyte interface.In order to resolve these issues,the carbon materials for the rational design of current collector/host that can regulate the plating/stripping behavior of alkali metal have been exploited.These carbon-based current collectors/hosts are featured with many pivotal advantages,including mechanical integrity to accommodate the volume change,superior electronic/ionic conductivity,large available surface area,and rich functionalization chemistries to increase the affinity to alkali metal.In this review,the recent progress on various dimensional carbon-based current collectors/hosts with different chemical components in stabilizing the alkali metal anodes through the regulation of initial deposition and subsequent growth behavior during plating/stripping process is provided.The nanostructured carbon scaffolds with self-affinity to alkali metals,as well as the carbon frameworks with internal/external affinitive sites to alkali metals,catalogued by various dimensions,are discussed in this review.Therefore,these appealing strategies based on the carbon-based current collectors/hosts can provide a paradigm for the realization of high-energy-density alkali metal batteries.
基金supported by the National Key Research and Development Program (Nos. 2016YFA0202500 and 2016YFA0200102)National Natural Science Foundation of China (Nos. 21676160, 21825501, 21805161, 21808121, and U1801257)the Tsinghua University Initiative Scientific Research Program.
文摘Lithium(Li) metal anode has received extensive attentions due to its ultrahigh theoretical capacity and the most negative electrode potential. However, dendrite growth severely impedes the practical applications of the Li metal anode in rechargeable batteries. In this contribution, a mesoporous graphene with a high specific surface area was synthesized to host the Li metal anode. The mesoporous graphene host(MGH) has a high specific surface area(2090 m^2/g), which affords free space and an interconnected conductive pathway for Li plating and stripping, thus alleviating the volume variation and reducing the generation of dead Li during repeated cycles. More importantly, the high specific surface area of MGH efficiently reduces the local current density of the electrode, which favors a uniform Li nucleation and plating behavior, rendering a dendritefree deposition morphology at a low overpotential. These factors synergistically boost the Li utilization(90.1% vs. 70.1% for Cu foil) and life span(150 cycles vs. 100 cycles for Cu foil) with a low polarization of MGH electrode at an ultrahigh current of 15.0 mA/cm^2. The as-prepared MGH can provide fresh insights into the electrode design of the Li metal anode operating at high rates.
基金supported by the National Natural Science Foundation of China(21805105,21975091 and 21773078)。
文摘Lithium-sulfur batteries(LSBs)are one of the most promising energy storage devices because of their high theoretical energy density;however,inherent issues including poor electrical conductivity and severe dissolution of S and its discharged products hinder their practical applications.MXenes have metallic conductivity,ultra-thin two-dimensional(2D)structures,rich surface functional groups,and macrostructural adjustability and have been widely used to design advanced sulfur hosts.3D network structures assembled by 2D MXene nanosheets have shown superior performance for improving reaction kinetics,accommodating and dispersing sulfur at the micro-/nanoscale,and capturing polysulfides due to their porous interconnected structure.Herein,the applications of MXene architectures related to 2D layered structures,3D multilayered structures,and 3D spherical structures as sulfur hosts are reviewed.The structure-performance relationship,challenges for current designs,and opportunities for future 3D architectures for LSBs are also analyzed.
基金The author sincerely thanks the financial supports from the National Natural Science Foundation of China(Grant Nos.51871188,51701169,and 51931006)National Key R&D Program of China(Grant No.2016YFA0202602)+1 种基金the Natural Science Foundation of Fujian Province of China(Grant No.2019J06003)the“Double‐First Class”Foundation of Materials and Intelligent Manufacturing Discipline of Xiamen University.
文摘With its high theoretical capacity,lithium(Li)metal is recognized as the most potential anode for realizing a high-performance energy storage system.A series of questions(severe safety hazard,low Coulombic efficiency,short lifetime,etc.)induced by uncontrollable dendrites growth,unstable solid electrolyte interface layer,and large volume change,make practical application of Li-metal anodes still a threshold.Due to their highly appealing properties,carbon-based materials as hosts to composite with Li metal have been passionately investigated for improving the performance of Li-metal batteries.This review displays an overview of the critical role of carbon-based hosts for improving the comprehensive performance of Li-metal anodes.Based on correlated mainstream models,the main failure mechanism of Li-metal anodes is introduced.The advantages and strategies of carbon-based hosts to address the corresponding challenges are generalized.The unique function,existing limitation,and recent research progress of key carbon-based host materials for Li-metal anodes are reviewed.Finally,a conclusion and an outlook for future research of carbon-based hosts are presented.This review is dedicated to summarizing the advances of carbon-based materials hosts in recent years and providing a reference for the further development of carbonbased hosts for advanced Li-metal anodes.
文摘Background: Cuscuta spp. known as dodders, have been used as traditional medicines in eastern and southern Asian countries for many disorders such as gastrointestinal, respiratory, endocrine, skin and neurological diseases (Drug of mania). Flavonoids are the main biologically active constituents in Cuscuta genus especially in C. chinensis. Our aim in this study was to identify and discriminate between C. chinensis samples which were collected from different hosts, by using the pattern recognition aided fingerprint analysis and comparison of the content of four major flavonoids (hyperoside, rutin, isorhamnetin, kaempferol). Material and methods: Samples were collected from nine different plants in the same time and place, dried, grinded and extracted with methanol (80%) by repeated maceration. Extractions were evaluated by high performance liquid chromatography analysis and fingerprinting. Results: Beside chromatographic fingerprint using similarity index, we compared the content of 4 major flavonoids (hyperoside, rutin, isorhamnetin, kaempferol) of C. chinensis samples on different hosts. Coclusion: The results showed that there were significant differences between the content of four major flavonoids of nine C. chinensis samples, but chromatographic fingerprint by similarity index of more than 0.88, showed that the sample consistency was similar. So, it was suggested that combination of chromatographic fingerprint and the content determination of major flavonoids could be used to evaluate the quality control of C. chinensis from different hosts.
基金Supported by Theodor Bilharz Research Institute,Imbaba,Giza,Egypt(Grant No.94M)
文摘Objective:To evaluate the predatory potential of the Odonata nymph on freshwater snails that serve as intermediate hosts for Schistosoma species(Bulinus truncatus and Biomphalaria alexandrina).Methods:Observations on the searching,attacking and devouring of the two snail types with series of laboratory-based predation experiments,whose aims were to determine daily predation rate,differential predation,prey preference considering small-,mediumand large-sized snails were conducted.Results:Laboratory evaluation revealed that,the Odonata nymph could kill and consume the two intermediate hosts.The number of snails consumed differed according to the snail type,size and density.The times taken for searching and handling times were dependent on the snail size,type and satiation of the predator.The predation rate varied also with respect to snail type,size and density.This study also evaluated that Odonata nymphs consumed more Bulinus truncatus than Biomphalaria alexandrina per unit time,and that there may be a preference for smaller than larger snails.Conclusions:According to our observation,the predator,Hemianax ephippiger nymph may be a suitable biocontrol agent in connection with Schistosoma intermediate hosts.
文摘The World Engineers’ Convention2004(WEC2004)was held onNovember 2-6,2004 in Shanghai,China. The motto of the conventionis“Engineers Shape the SustainableFuture.”It advocates that engineersshould take the task of makingpeople’s life better and commit tocreating a new world.Engineers should be well awareof their responsibilities:developingnew technologies and making good
文摘Interoperability of symmetric 10G-EPON products was demonstrated successfully in Shanghai, China in April 2010. Interoperability among products was successfully demonstrated by four vendors: Broadcom, PMC-Sierra Opulan and ZTE. Each vendor supplied an OLT and a variety of ONUs (supporting both 1G-EPON and symmetric 10G-EPON), connected in a multi-vendor
基金Supported by Student Innovation Project of University of Science and Technology Liaoning in 2017(201710146000016)
文摘With constant economic development and continuous improvement of living standards in Northeast China,rural tourism,as a new type of tourism,is increasingly favored. From the perspective of symbolic interaction theory,taking the current situation of rural tourism in Northeast China as an example,this paper explained the semiotic significance between hosts and guests in rural tourism. It established the evaluation indicators for authentic symbolic perception of rural tourism. Also,combined with the theories of sociology and anthropology,it studied the interaction between hosts and tourists of rural tourism in Northeast China.
文摘In Brazil,schistosomiasis occurrence is related to the presence of the etiological agent Schistosoma mansoni.The presence of mollusks for Biomphalaria genus is a necessary condition for development of the parasite cycle.In Parástate,the species B.schrammi,B.kuhniana,B.straminea and B.glabrata have already been identified,with reports of the last two occurring in Belém.The aim of this study was to determine the spatial distribution of Biomphalaria species in Belém,Pará,Brazil,identifying risk areas for schistosomiasis transmission.Biannual malacological surveys were carried out between September 2013 and October 2017 in 35 neighborhoods of Belém.The collection points were georeferenced using a Global Positioning System(GPS)receiver and the Kernel Density Estimation(KDE)was used to the spatial analysis.The mollusks,after measurement,were exposed to light to verify the presence of S.mansoni cercariae.Subsequently,mollusks were sacrificed and fixed for dissection and morphological identification of species.The surveys resulted in a total of 10,803 mollusks collected,of which 9,367(86.70%)specimens were examined.Among the analyzed mollusks,5,820(62.14%)were identified as B.glabrata and 3,547(37.86%)as B.straminea.The presence of the parasite was observed in 208(2.22%)specimens,all B.glabrata.Positive mollusks were found in six neighborhoods:Guamá(51 mollusks/24.5%),Sacramenta(47 mollusks/22.6%),Telégrafo(47 mollusks/22.6%),Terra Firme(36 mollusks/17.3%),Condor(20 mollusks/9.6%)and Barreiro(7 mollusks/3.4%).This study confirms that B.glabrata species actively participates as intermediate host in the disease maintenance in Belém.The KDE allowed to analyze the spatial distribution of collection sites and consequently to determine possible risk areas of schistosomiasis transmission in Belem.The development of maps identifying sites with schistosomiasis positive snails may support efforts of this municipality by directing activities related to endemic disease control.