Although pharmaceuticals have beendetected in the environment only in the range from ng/L to μg/L, it has beendemonstrated that they can adversely affect the health status of aquatic organisms. Lysosomal membrane sta...Although pharmaceuticals have beendetected in the environment only in the range from ng/L to μg/L, it has beendemonstrated that they can adversely affect the health status of aquatic organisms. Lysosomal membrane stability （LMS） has previously been applied as an indicator of cellularwell-being todetermine health status in bivalve mussels. The objective of this study is to evaluate LMS in Ruditapes philippinarum haemolymph using the neutral red retention assay （NRRA）. Clamswere exposed in laboratory conditions to caffeine （0.1, 5, 15, 50 μg/L）, ibuprofen （0.1, 5, 10, 50 μg/L）, carbamazepine and novobiocin （both at 0.1, 1, 10, 50 μg/L） for35days. Results show adose-dependent effect of the pharmaceuticals. The neutral red retention time measured at the end of the bioassaywas significantly reduced by 50% after exposure to environmental concentrations （p 〈 0.05） （caffeine = 15 μg/L; ibuprofen = 10 μg/L; carbamazepine = 1 μg/L and novobiocin = 1 μg/L）, compared to controls. Clams exposed to these pharmaceuticalswere considered to present adiminished health status （retention time 〈45 min）, significantlyworse than controls （96 min） （p 〈 0.05）. The predicted no environmental effect concentration （PNEC） results showed that these pharmaceuticals are very toxic at the environmental concentrations tested. Measurement of the alteration of LMS has been found to be a sensitive technique that enables evaluation of the health status of clams after exposure to pharmaceuticals under laboratory conditions, thus representing a robust Tier-1 screening biomarker.展开更多
The Okinawa Trench in the East China Sea and the Manila Trench in the South China Sea are considered to be the regions with high risk of potential tsunamis induced by submarine earthquakes. Tsunami waves will impact t...The Okinawa Trench in the East China Sea and the Manila Trench in the South China Sea are considered to be the regions with high risk of potential tsunamis induced by submarine earthquakes. Tsunami waves will impact the southeast coast of China if tsunamis occur in these areas. In this paper, the horizontal two-dimensional Boussinesq model is used to simulate tsunami generation, propagation, and runnp in a domain with complex geometrical boundaries. The temporary varying bottom boundary condition is adopted to describe the initial tsunami waves motivated by the submarine faults. The Indian Ocean tsunami is simulated by the numerical model as a validation case. The time series of water elevation and runup on the beach are compared with the measured data from field survey. The agreements indicate that the Boussinesq model can be used to simulate tsunamis and predict the waveform and runup. Then, the hypothetical tsunamis in the Okinawa Trench and the Manila Trench are simulated by the numerical model. The arrival time and maximum wave height near coastal cities are predicted by the model. It turns out that the leading depression N-wave occurs when the tsunami propagates in the continental shelf from the Okinawa Trench. The scenarios of the tsunami in the Manila Trench demonstrate significant effects on the coastal area around the South China Sea.展开更多
Manila Trench is a critical region for revealing the tectonic evolution and source-to-sink process of the South China Sea,but the sediment provenance in the northern part of the trench remains unclear.In this study,we...Manila Trench is a critical region for revealing the tectonic evolution and source-to-sink process of the South China Sea,but the sediment provenance in the northern part of the trench remains unclear.In this study,we present a first detrital zircon U-Pb geochronology of sediments in the northern Manila Trench,in the vicinity of Northwestern Luzon Island,to identify the sediment provenance and understand the source-to-sink process in the marginal sea.The study shows that the sediments yielded multiple zircon age populations at ca.123,221,443,565,906,and 1871 Ma.A detailed detrital zircon age study indicates that the sediments were derived mainly from Taiwan Island,China,rather than the nearby Luzon Island.In comparison with the modern drainage systems surrounding northeastern South China Sea,this study further confirms that the sediments primarily originated from the Gaoping River(ca.45%),with subordinate contributions from the Lanyang River(ca.24%)and Min River(ca.19%).The study also elucidates two completely different sedimentary transport modes in the northern Manila Trench.The transportation of sediments from southwestern Taiwan Island is primarily related to the gravity-driven transport through the Gaoping submarine canyon.Furthermore,a quarter of detritus derived from eastern Taiwan Island might have been transported by the deep-water circulation of the Luzon Strait.This study highlights the provenance and transport pathway of sediments in the northern Manila Trench and provides a solution for understanding the source-to-sink process in the marginal sea.展开更多
Increasing intense human activities have largely changed the coastal landscape and caused many environmental issues.However,whether human-induced activities could change the coastal land use gradient pattern,an import...Increasing intense human activities have largely changed the coastal landscape and caused many environmental issues.However,whether human-induced activities could change the coastal land use gradient pattern,an important coastal zonal characteristic along the sea-land direction,remains unclear.Manila Bay was selected as the study area in this work.According to the distance of the land use and land cover(LULC)to the coastline,we clustered the typical coastal land use sequence patterns(CLUSPs)along the sea-land direction between 1988 and 2016 in Manila Bay and found the following.(1)Four typical CLUSPs,including the natural CLUSP dominated by forest land and grassland,the agricultural CLUSP dominated by dry farm and paddy field,the urbanised CLUSP dominated by construction land and the fishery CLUSP dominated by fishing farm,were mined in 1988.Three typical CLUSPs(a natural CLUSP,an intermediate CLUSP between the agricultural and urbanised CLUSPs,and a fishery CLUSP)were mined in 2016.(2)Affected by the dominant LULC,these typical CLUSPs showed a regular spatial pattern along the sea-land direction.For example,the typical natural CLUSP showed a landward pattern due to the long distance between the forest land and grassland and the coastline.(3)However,influenced by urban and aquaculture expansion,the land intensification of the CLUSP exhibited an obvious increase and caused the decrease of the CLUSP diversity from 1988 to 2016.The increase in the area of LULC coverage showed no obvious correlation with its distance from the coastline(DFC),but the net increase rate of LULC coverage had a significant negative correlation with the DFC.Therefore,human-induced activities have a large impact on the gradient pattern of coastal land use along the sea-land direction.展开更多
Genomic DNA was extracted from hypnospores of Perkinsus-like parasite of Manila clam Ruditapes philippinarum collected at the fishing grounds in Huanghai Sea coast Shicheng Island and East China Sea coast Ningbo, Chin...Genomic DNA was extracted from hypnospores of Perkinsus-like parasite of Manila clam Ruditapes philippinarum collected at the fishing grounds in Huanghai Sea coast Shicheng Island and East China Sea coast Ningbo, China. The internal transcribed spacer（ITS） in rDNA was PCR-amplified, cloned, sequenced, and compared with that of five Perkinsus species in GenBank. The fragment amplified from DNA of parasite of either Shicheng Island or Ningbo contained 649 bp, including partial ssrRNA（51 bp） and ITS（＋5.8 S） （598 bp） regions. The ITS（＋5.SS） sequences of Perkinsus-like parasite of both Shicheng Island and Ningbo were all 99% identical to those ofPerkinsis atlanticus, and were not more than 95% identical to those of other four Perkinsus species including P. marinus, P. andrewsi, P. qugwadi and P. medierraneus.The ITS （＋5.8S） sequence of Perkinsus-like parasite of Shicheng Island was 99% identical to that of Ningbo. These facts about nucleotide sequences suggested that the Perkinsus-like parasite in Manila clam, Ruditapes philippinarum collected from either the Huanghai Sea coast or the East China Sea coast was P. atlanticus, and might reflect P. atlanticus strains of distinct geographic distribution.展开更多
Eelgrass species worldwide are valued for the ecosystem service they provide to estuarine and marine habitats. One species, Zostera japonica, however, has some negative impacts outside its native range and is consider...Eelgrass species worldwide are valued for the ecosystem service they provide to estuarine and marine habitats. One species, Zostera japonica, however, has some negative impacts outside its native range and is considered invasive. In Willapa Bay WA, USA, the nonnative eelgrass has expanded to the level where the shellfish industry is concerned about its potential impacts on its livelihood. Studies were conducted using paired plots, Z. japonica controlled with the herbicide imazamox vs. untreated controls, to assess the effects of Z. japonica on Manila clams (Ruditapes philippinarum) and Pacific oysters (Crassostrea gigas). Recruitment of new Manila clams was not affected by Z. japonica. The growth of young clams, total commercial clam harvests, clam quality and clam harvest efficiency, however, were greater on plots where Z. japonica was chemically controlled than where it was not treated. The response of oysters to Z. japonica control varied by site;there was no effect at one site, while the other sites had a 15% increase in shucked meat with Z. japonica control. The potential economic impact of a Z. japonica infestation of a shellfish bed was ~$47,000 ha-1 for Manila clams and $4000 ha-1 for oysters for each crop harvest cycle.展开更多
The Manila clam Venerupis philippinarum is a good biomonitor/bioindicator to marine metal pollution and is frequently used in aquatic toxicology. Two dominant pedigrees (white and zebra) of clam are distributed in the...The Manila clam Venerupis philippinarum is a good biomonitor/bioindicator to marine metal pollution and is frequently used in aquatic toxicology. Two dominant pedigrees (white and zebra) of clam are distributed in the Bohai Sea; however, little attention has been paid to potential biological differences between these two pedigrees. In this study, we tested the sensitivity of both pedigrees to marine metal (cadmium and zinc) pollution biomonitoring and marine environmental toxicology. Results demonstrate significant biological differences in gills of white and zebra clams based on metabolic profiles and antioxidant enzyme activities. In addition, we found that hypotaurine, malonate and homarine were relatively high in white clam gills, while alanine, arginine, glutamate, succinate, 4-aminobutyrate, taurine and betaine were high in zebra clam gills. Zebra clam gills were also more sensitive to a mixture of Cd and Zn, as shown by antioxidant enzyme activities and metabolic profiles, but white clam gills could accumulate more Zn. Therefore, we suggest that the white pedigree can be used as a biomonitor to marine Zn pollution, whereas the zebra pedigree can be used for toxicology studies on Cd and Zn mixed pollution.展开更多
In order to determine whether growth performance could be improved by hybridizing full-sib families of Manila clam （Ruditapes philippinarum）, crosses between two full-sib families including self and reciprocal cross...In order to determine whether growth performance could be improved by hybridizing full-sib families of Manila clam （Ruditapes philippinarum）, crosses between two full-sib families including self and reciprocal crosses were carried out. The effects of heterosis, combining ability and interaction on the growth of shell length were estimated. The results showed that the growth of hybrid larvae was intermediate between parents on days 6 and 9. Heterosis on shell length was observed, which varied at juvenile stage. The cross of ♂A×♀B （Hp varied between 10.41% and 68.27%） displayed larger heterosis than ♂A×♀B （Hp varied between 1.89% and 32.33%） did, suggesting that ♂A×♀B was an ideal hatchery method of improving the growth performance of Manila clam. The variances of general combining ability （GCA）, special combining ability （SCA） and interaction （I） were significant in shell length （P〈 0.05）, indicating that both additive and non-additive genetic factors were important contributors to the growth of larvae and juveniles. The GCA for shell length of ♂A×♀B was higher than that of ♂A×♀B at both larval and juvenile stages. This con- firmed that the cross between ♂A and ♀B showed great growth in shell length. In summary, the growth of Manila clam seeds could be improved by hybridizing selected parents from large numbers of full-sib families.展开更多
Natural plant fibers, including flax, kenaf, jute, bamboo, ramie and much more are renewable and sustainable resources and are considered good candidates for cost-effective alternatives to glass and carbon fibers. In ...Natural plant fibers, including flax, kenaf, jute, bamboo, ramie and much more are renewable and sustainable resources and are considered good candidates for cost-effective alternatives to glass and carbon fibers. In this research, cross ply biodegradable composites were fabricated by press-forming method. The biodegradable composites consist of Manila hemp textile as a reinforcement and starch-based biodegradable plastics as a matrix was fabricated and investigated about mechanical properties. The tensile strength increased with the fiber content until fiber content of about 50% and leveled off thereafter. This dependence on the fiber content is due to the decrease in fiber strength of loading direction caused by fiber damages introduced during hot-pressing. In order to decrease the damage of fibers aligned in loading direction, Manila hemp textile was produced by using Manila hemp fibers for warp and biodegradable resin thread for weft. As a result, the tensile strength of cross ply composites increased from 153 MPa to 202 MPa.展开更多
This work details the simulation of tsunami waves generated by seaquakes in the Manila Trench and their effect on fixed oil and gas jacket platforms in waters offshore North Borneo. For this study, a four-leg living q...This work details the simulation of tsunami waves generated by seaquakes in the Manila Trench and their effect on fixed oil and gas jacket platforms in waters offshore North Borneo. For this study, a four-leg living quarter jacket platform located in a water depth of 63 m is modelled in SACS v5.3. Malaysia has traditionally been perceived to be safe from the hazards of earthquakes and tsunamis. Local design practices tend to neglect tsunami waves and include no such provisions. In 2004, a 9.3Mw seaquake occurred off the northwest coast of Aceh, which generated tsunami waves that caused destruction in Malaysia totalling US$ 25 million and 68 deaths. This event prompted an awareness of the need to study the reliability of fixed offshore platforms scattered throughout Malaysian waters. In this paper, we present a review of research on the seismicity of the Manila Trench, which is perceived to be high risk for Southeast Asia. From the tsunami numerical model TUNA-M2, we extract computer-simulated tsunami waves at prescribed grid points in the vicinity of the platforms in the region. Using wave heights as input, we simulate the tsunami using SACS v5.3 structural analysis software of offshore platforms, which is widely accepted by the industry. We employ the nonlinear solitary wave theory in our tsunami loading calculations for the platforms, and formulate a platform-specific risk quantification system. We then perform an intensive structural sensitivity analysis and derive a corresponding platform-specific risk rating model.展开更多
According to the activity of earthquakes and volcanoes along the Manila trench and its adjacent region, combined with analysis of focal mechanism solutions and geophysics data, the Manila trench is still being downwar...According to the activity of earthquakes and volcanoes along the Manila trench and its adjacent region, combined with analysis of focal mechanism solutions and geophysics data, the Manila trench is still being downward subduction in the depth of 200 km. Deep earthquakes mainly concentrate between 12°N and 14°N, the concentrated region is divided into different sections, and the focal depth is gradually deep from the north to the south. From the focal mechanism solution data, the maximum principal stress direction (P axis) varies from the northern region of Philippine fault to the southern region of the fault. In the north P axes directions are mainly NW, however in the south there is the complex displaying and P axes have NW, NE and approximately NS directions. These results show the characteristics of press-thrust in the northern region of the Philippine fault and the clockwise rotation in the southern region of the fault. The stress caused by the Philippine plate, which moved upon the South China Sea sub-plate, is adjusted by the oblique subduction of the Manila trench, the sinistral strike-slip of the Philippine fault and the sinistral strike-slip of the Mindoro fault.展开更多
The coupling numerical model between astronomical tide and tsunamis was built based on the data of the COMCOT model, which was verified by the Japan "3·11" tsunami. The tsunami source of the Manila seis...The coupling numerical model between astronomical tide and tsunamis was built based on the data of the COMCOT model, which was verified by the Japan "3·11" tsunami. The tsunami source of the Manila seismic tsunami was designed and computed to analyze the risk of tsunami which will happen in the Guangdong coast. According to the results, the maximum quantity of water increasing and the time of the tsunami arriving at the Guangdong seacoast were calculated. The coupling simulation between astronomical tide and tsunamis has significant meaning for evaluating the risk and early-warning of tsunamis in the Guangdong coastal area.展开更多
Chemical inducement and DDRT-PCR （differential display reverse transcription PCR） are adopted to investigate the effect of epinephrine （EPI） on the settlement and metamorphosis of Manila clam larvae. Chemical indu...Chemical inducement and DDRT-PCR （differential display reverse transcription PCR） are adopted to investigate the effect of epinephrine （EPI） on the settlement and metamorphosis of Manila clam larvae. Chemical inducement shows that EPI has an effect to some extent on the metamorphosis of Manila clam larvae at all concentrations and in all treatments designed. The most significant result of inducement is obtained at the concentration of 10^-6 tool L^-1 and for 4 h. DDRT-PCR using six primer pairs shows that the gene expression pattern is quite different between EPI treatment and the control. Three hundred and forty-three amplification bands are obtained in total, among which, 67 （19.53%） are differentially appeared. Therefore, EPI has an effect on the gene expression of the eye spot larval Manila clam. It can be hypothesized that EPI is a settlement and metamorphosis inducer for Manila clam. EPI may lead to larvae settlement and metamorphosis by binding to the receptors on the membrane and then changing the gene expression of larvae cells.展开更多
所谓'早期马尼拉闽南语'(Early Manila Hokkien,简称EMH),是指十七世纪初菲律宾马尼拉地区华侨所说的闽南语。这种闽南语的片段曾经被当时驻菲的天主教传教士记录下来。其中一份最有名的文献,是Arte de la lengua chio chiu。...所谓'早期马尼拉闽南语'(Early Manila Hokkien,简称EMH),是指十七世纪初菲律宾马尼拉地区华侨所说的闽南语。这种闽南语的片段曾经被当时驻菲的天主教传教士记录下来。其中一份最有名的文献,是Arte de la lengua chio chiu。韩可龙(Kloter2011)把该书翻译为英语并做了精心的校订,为研究者提供了很大的便利。本文以'原始闽南语'(Proto-South Min)为出发点,全面检视Arte的音韵系统,试图厘清它所反映的EMH系属问题。比较证明:EMH和'闽南语南支福建小支'共享为数不少的音韵创新,因此把EMH归到那个小支去,应该是没有问题的。'福建小支'的成员包括漳州话、大田话和龙岩话等。另一方面,EMH并非完全没有混杂的成分,这可由若干罕见于'福建小支'的音变,以及个别含'闽南语北支'特点的拼写反映出来。展开更多
基金conducted under the framework of the project P09-RNM-5136(Government of Andalu-sia,Spain)partially financed by the UN-ESCO/UNITWIN/WiCop as part of the research activities of the Erasmus Mundus Master's degree in Water and Coastal Managementthe financial support from MAEC-AECID(Government of Spain),Becas Chile(Government of Chile),and Junta de Andaluc'a(Government of Andalusia,Spain)
文摘Although pharmaceuticals have beendetected in the environment only in the range from ng/L to μg/L, it has beendemonstrated that they can adversely affect the health status of aquatic organisms. Lysosomal membrane stability （LMS） has previously been applied as an indicator of cellularwell-being todetermine health status in bivalve mussels. The objective of this study is to evaluate LMS in Ruditapes philippinarum haemolymph using the neutral red retention assay （NRRA）. Clamswere exposed in laboratory conditions to caffeine （0.1, 5, 15, 50 μg/L）, ibuprofen （0.1, 5, 10, 50 μg/L）, carbamazepine and novobiocin （both at 0.1, 1, 10, 50 μg/L） for35days. Results show adose-dependent effect of the pharmaceuticals. The neutral red retention time measured at the end of the bioassaywas significantly reduced by 50% after exposure to environmental concentrations （p 〈 0.05） （caffeine = 15 μg/L; ibuprofen = 10 μg/L; carbamazepine = 1 μg/L and novobiocin = 1 μg/L）, compared to controls. Clams exposed to these pharmaceuticalswere considered to present adiminished health status （retention time 〈45 min）, significantlyworse than controls （96 min） （p 〈 0.05）. The predicted no environmental effect concentration （PNEC） results showed that these pharmaceuticals are very toxic at the environmental concentrations tested. Measurement of the alteration of LMS has been found to be a sensitive technique that enables evaluation of the health status of clams after exposure to pharmaceuticals under laboratory conditions, thus representing a robust Tier-1 screening biomarker.
基金financially supported by the National Natural Science Foundation of China(Grant No.11202130)the National Science Foundation of Shanghai Municipality(Grant No.11ZR1418200)the Doctoral Program Foundation of Higher Education(Grant No.20060248046)
文摘The Okinawa Trench in the East China Sea and the Manila Trench in the South China Sea are considered to be the regions with high risk of potential tsunamis induced by submarine earthquakes. Tsunami waves will impact the southeast coast of China if tsunamis occur in these areas. In this paper, the horizontal two-dimensional Boussinesq model is used to simulate tsunami generation, propagation, and runnp in a domain with complex geometrical boundaries. The temporary varying bottom boundary condition is adopted to describe the initial tsunami waves motivated by the submarine faults. The Indian Ocean tsunami is simulated by the numerical model as a validation case. The time series of water elevation and runup on the beach are compared with the measured data from field survey. The agreements indicate that the Boussinesq model can be used to simulate tsunamis and predict the waveform and runup. Then, the hypothetical tsunamis in the Okinawa Trench and the Manila Trench are simulated by the numerical model. The arrival time and maximum wave height near coastal cities are predicted by the model. It turns out that the leading depression N-wave occurs when the tsunami propagates in the continental shelf from the Okinawa Trench. The scenarios of the tsunami in the Manila Trench demonstrate significant effects on the coastal area around the South China Sea.
基金supported by the National Natural Science Foundation of China(Grant No.4217020131)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2019A1515012017)the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(Grant No.SML2021SP307)。
文摘Manila Trench is a critical region for revealing the tectonic evolution and source-to-sink process of the South China Sea,but the sediment provenance in the northern part of the trench remains unclear.In this study,we present a first detrital zircon U-Pb geochronology of sediments in the northern Manila Trench,in the vicinity of Northwestern Luzon Island,to identify the sediment provenance and understand the source-to-sink process in the marginal sea.The study shows that the sediments yielded multiple zircon age populations at ca.123,221,443,565,906,and 1871 Ma.A detailed detrital zircon age study indicates that the sediments were derived mainly from Taiwan Island,China,rather than the nearby Luzon Island.In comparison with the modern drainage systems surrounding northeastern South China Sea,this study further confirms that the sediments primarily originated from the Gaoping River(ca.45%),with subordinate contributions from the Lanyang River(ca.24%)and Min River(ca.19%).The study also elucidates two completely different sedimentary transport modes in the northern Manila Trench.The transportation of sediments from southwestern Taiwan Island is primarily related to the gravity-driven transport through the Gaoping submarine canyon.Furthermore,a quarter of detritus derived from eastern Taiwan Island might have been transported by the deep-water circulation of the Luzon Strait.This study highlights the provenance and transport pathway of sediments in the northern Manila Trench and provides a solution for understanding the source-to-sink process in the marginal sea.
基金The Innovation Academy of South China Sea Ecology and Environmental Engineering,Chinese Academy of Sciences under contract No.ISEE2020YB06the National Natural Science Foundation of China under contract Nos 41830648 and 41801353+3 种基金the Chongqing Postdoctoral Innovation Fund under contract No.cstc2020jcyj-bshX0103the Grant from the State Key Laboratory of Resources and Environmental Information Systemthe Open Project Programme of the Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions under contract No.GTYR201906the Open Project Programme of Chongqing Key Laboratory of Karst Environment under contract No.Cqk201903.
文摘Increasing intense human activities have largely changed the coastal landscape and caused many environmental issues.However,whether human-induced activities could change the coastal land use gradient pattern,an important coastal zonal characteristic along the sea-land direction,remains unclear.Manila Bay was selected as the study area in this work.According to the distance of the land use and land cover(LULC)to the coastline,we clustered the typical coastal land use sequence patterns(CLUSPs)along the sea-land direction between 1988 and 2016 in Manila Bay and found the following.(1)Four typical CLUSPs,including the natural CLUSP dominated by forest land and grassland,the agricultural CLUSP dominated by dry farm and paddy field,the urbanised CLUSP dominated by construction land and the fishery CLUSP dominated by fishing farm,were mined in 1988.Three typical CLUSPs(a natural CLUSP,an intermediate CLUSP between the agricultural and urbanised CLUSPs,and a fishery CLUSP)were mined in 2016.(2)Affected by the dominant LULC,these typical CLUSPs showed a regular spatial pattern along the sea-land direction.For example,the typical natural CLUSP showed a landward pattern due to the long distance between the forest land and grassland and the coastline.(3)However,influenced by urban and aquaculture expansion,the land intensification of the CLUSP exhibited an obvious increase and caused the decrease of the CLUSP diversity from 1988 to 2016.The increase in the area of LULC coverage showed no obvious correlation with its distance from the coastline(DFC),but the net increase rate of LULC coverage had a significant negative correlation with the DFC.Therefore,human-induced activities have a large impact on the gradient pattern of coastal land use along the sea-land direction.
基金This study was supported by the National Natural Science Foundation of China under contract No.30070124.
文摘Genomic DNA was extracted from hypnospores of Perkinsus-like parasite of Manila clam Ruditapes philippinarum collected at the fishing grounds in Huanghai Sea coast Shicheng Island and East China Sea coast Ningbo, China. The internal transcribed spacer（ITS） in rDNA was PCR-amplified, cloned, sequenced, and compared with that of five Perkinsus species in GenBank. The fragment amplified from DNA of parasite of either Shicheng Island or Ningbo contained 649 bp, including partial ssrRNA（51 bp） and ITS（＋5.8 S） （598 bp） regions. The ITS（＋5.SS） sequences of Perkinsus-like parasite of both Shicheng Island and Ningbo were all 99% identical to those ofPerkinsis atlanticus, and were not more than 95% identical to those of other four Perkinsus species including P. marinus, P. andrewsi, P. qugwadi and P. medierraneus.The ITS （＋5.8S） sequence of Perkinsus-like parasite of Shicheng Island was 99% identical to that of Ningbo. These facts about nucleotide sequences suggested that the Perkinsus-like parasite in Manila clam, Ruditapes philippinarum collected from either the Huanghai Sea coast or the East China Sea coast was P. atlanticus, and might reflect P. atlanticus strains of distinct geographic distribution.
文摘Eelgrass species worldwide are valued for the ecosystem service they provide to estuarine and marine habitats. One species, Zostera japonica, however, has some negative impacts outside its native range and is considered invasive. In Willapa Bay WA, USA, the nonnative eelgrass has expanded to the level where the shellfish industry is concerned about its potential impacts on its livelihood. Studies were conducted using paired plots, Z. japonica controlled with the herbicide imazamox vs. untreated controls, to assess the effects of Z. japonica on Manila clams (Ruditapes philippinarum) and Pacific oysters (Crassostrea gigas). Recruitment of new Manila clams was not affected by Z. japonica. The growth of young clams, total commercial clam harvests, clam quality and clam harvest efficiency, however, were greater on plots where Z. japonica was chemically controlled than where it was not treated. The response of oysters to Z. japonica control varied by site;there was no effect at one site, while the other sites had a 15% increase in shucked meat with Z. japonica control. The potential economic impact of a Z. japonica infestation of a shellfish bed was ~$47,000 ha-1 for Manila clams and $4000 ha-1 for oysters for each crop harvest cycle.
基金Supported by the National Natural Science Foundation of China (No.41106102)Shandong Science Foundation of China (No. ZR2009CZ008)the 100 Talents Program of the Chinese Academy of Sciences
文摘The Manila clam Venerupis philippinarum is a good biomonitor/bioindicator to marine metal pollution and is frequently used in aquatic toxicology. Two dominant pedigrees (white and zebra) of clam are distributed in the Bohai Sea; however, little attention has been paid to potential biological differences between these two pedigrees. In this study, we tested the sensitivity of both pedigrees to marine metal (cadmium and zinc) pollution biomonitoring and marine environmental toxicology. Results demonstrate significant biological differences in gills of white and zebra clams based on metabolic profiles and antioxidant enzyme activities. In addition, we found that hypotaurine, malonate and homarine were relatively high in white clam gills, while alanine, arginine, glutamate, succinate, 4-aminobutyrate, taurine and betaine were high in zebra clam gills. Zebra clam gills were also more sensitive to a mixture of Cd and Zn, as shown by antioxidant enzyme activities and metabolic profiles, but white clam gills could accumulate more Zn. Therefore, we suggest that the white pedigree can be used as a biomonitor to marine Zn pollution, whereas the zebra pedigree can be used for toxicology studies on Cd and Zn mixed pollution.
基金supported by the earmarked fund for Modern Agro-industry Technology Research System (CARS-48)grants from the ‘863’ Project of China (2012AA10AA400)
文摘In order to determine whether growth performance could be improved by hybridizing full-sib families of Manila clam （Ruditapes philippinarum）, crosses between two full-sib families including self and reciprocal crosses were carried out. The effects of heterosis, combining ability and interaction on the growth of shell length were estimated. The results showed that the growth of hybrid larvae was intermediate between parents on days 6 and 9. Heterosis on shell length was observed, which varied at juvenile stage. The cross of ♂A×♀B （Hp varied between 10.41% and 68.27%） displayed larger heterosis than ♂A×♀B （Hp varied between 1.89% and 32.33%） did, suggesting that ♂A×♀B was an ideal hatchery method of improving the growth performance of Manila clam. The variances of general combining ability （GCA）, special combining ability （SCA） and interaction （I） were significant in shell length （P〈 0.05）, indicating that both additive and non-additive genetic factors were important contributors to the growth of larvae and juveniles. The GCA for shell length of ♂A×♀B was higher than that of ♂A×♀B at both larval and juvenile stages. This con- firmed that the cross between ♂A and ♀B showed great growth in shell length. In summary, the growth of Manila clam seeds could be improved by hybridizing selected parents from large numbers of full-sib families.
文摘Natural plant fibers, including flax, kenaf, jute, bamboo, ramie and much more are renewable and sustainable resources and are considered good candidates for cost-effective alternatives to glass and carbon fibers. In this research, cross ply biodegradable composites were fabricated by press-forming method. The biodegradable composites consist of Manila hemp textile as a reinforcement and starch-based biodegradable plastics as a matrix was fabricated and investigated about mechanical properties. The tensile strength increased with the fiber content until fiber content of about 50% and leveled off thereafter. This dependence on the fiber content is due to the decrease in fiber strength of loading direction caused by fiber damages introduced during hot-pressing. In order to decrease the damage of fibers aligned in loading direction, Manila hemp textile was produced by using Manila hemp fibers for warp and biodegradable resin thread for weft. As a result, the tensile strength of cross ply composites increased from 153 MPa to 202 MPa.
基金Universiti Teknologi PETRONAS Research Grant(No.0153B2-A44)
文摘This work details the simulation of tsunami waves generated by seaquakes in the Manila Trench and their effect on fixed oil and gas jacket platforms in waters offshore North Borneo. For this study, a four-leg living quarter jacket platform located in a water depth of 63 m is modelled in SACS v5.3. Malaysia has traditionally been perceived to be safe from the hazards of earthquakes and tsunamis. Local design practices tend to neglect tsunami waves and include no such provisions. In 2004, a 9.3Mw seaquake occurred off the northwest coast of Aceh, which generated tsunami waves that caused destruction in Malaysia totalling US$ 25 million and 68 deaths. This event prompted an awareness of the need to study the reliability of fixed offshore platforms scattered throughout Malaysian waters. In this paper, we present a review of research on the seismicity of the Manila Trench, which is perceived to be high risk for Southeast Asia. From the tsunami numerical model TUNA-M2, we extract computer-simulated tsunami waves at prescribed grid points in the vicinity of the platforms in the region. Using wave heights as input, we simulate the tsunami using SACS v5.3 structural analysis software of offshore platforms, which is widely accepted by the industry. We employ the nonlinear solitary wave theory in our tsunami loading calculations for the platforms, and formulate a platform-specific risk quantification system. We then perform an intensive structural sensitivity analysis and derive a corresponding platform-specific risk rating model.
基金South China Sea Institute of Oceanology (LYQY200302),The Chinese Ministry of Science and Technology (G2000046701), National Natural Science Foundation of China (40476026) and Guangdong Natural Science Foundation (040013090).
文摘According to the activity of earthquakes and volcanoes along the Manila trench and its adjacent region, combined with analysis of focal mechanism solutions and geophysics data, the Manila trench is still being downward subduction in the depth of 200 km. Deep earthquakes mainly concentrate between 12°N and 14°N, the concentrated region is divided into different sections, and the focal depth is gradually deep from the north to the south. From the focal mechanism solution data, the maximum principal stress direction (P axis) varies from the northern region of Philippine fault to the southern region of the fault. In the north P axes directions are mainly NW, however in the south there is the complex displaying and P axes have NW, NE and approximately NS directions. These results show the characteristics of press-thrust in the northern region of the Philippine fault and the clockwise rotation in the southern region of the fault. The stress caused by the Philippine plate, which moved upon the South China Sea sub-plate, is adjusted by the oblique subduction of the Manila trench, the sinistral strike-slip of the Philippine fault and the sinistral strike-slip of the Mindoro fault.
基金sponsored by the Youth Fund Project of the National Natural Science Foundation of China(51509023)the Open-end Fund Project of State Key Laboratory of Hydraulic Engineering Simulation and Safety(HESS-1401)+3 种基金Major Open-end Fund Project of Key Laboratory of South China Sea Rights Protection Technology and Application,State Oceanic Administration(SCS1606)Open-end Fund of Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province(2017SS04)Project supported by South China Sea Branch,State Oceanic Administration for Director of Marine Science and Technology(1417)Key Founding of South China Sea Branch of State Oceanic Administration(180106)
文摘The coupling numerical model between astronomical tide and tsunamis was built based on the data of the COMCOT model, which was verified by the Japan "3·11" tsunami. The tsunami source of the Manila seismic tsunami was designed and computed to analyze the risk of tsunami which will happen in the Guangdong coast. According to the results, the maximum quantity of water increasing and the time of the tsunami arriving at the Guangdong seacoast were calculated. The coupling simulation between astronomical tide and tsunamis has significant meaning for evaluating the risk and early-warning of tsunamis in the Guangdong coastal area.
文摘Chemical inducement and DDRT-PCR （differential display reverse transcription PCR） are adopted to investigate the effect of epinephrine （EPI） on the settlement and metamorphosis of Manila clam larvae. Chemical inducement shows that EPI has an effect to some extent on the metamorphosis of Manila clam larvae at all concentrations and in all treatments designed. The most significant result of inducement is obtained at the concentration of 10^-6 tool L^-1 and for 4 h. DDRT-PCR using six primer pairs shows that the gene expression pattern is quite different between EPI treatment and the control. Three hundred and forty-three amplification bands are obtained in total, among which, 67 （19.53%） are differentially appeared. Therefore, EPI has an effect on the gene expression of the eye spot larval Manila clam. It can be hypothesized that EPI is a settlement and metamorphosis inducer for Manila clam. EPI may lead to larvae settlement and metamorphosis by binding to the receptors on the membrane and then changing the gene expression of larvae cells.
文摘所谓'早期马尼拉闽南语'(Early Manila Hokkien,简称EMH),是指十七世纪初菲律宾马尼拉地区华侨所说的闽南语。这种闽南语的片段曾经被当时驻菲的天主教传教士记录下来。其中一份最有名的文献,是Arte de la lengua chio chiu。韩可龙(Kloter2011)把该书翻译为英语并做了精心的校订,为研究者提供了很大的便利。本文以'原始闽南语'(Proto-South Min)为出发点,全面检视Arte的音韵系统,试图厘清它所反映的EMH系属问题。比较证明:EMH和'闽南语南支福建小支'共享为数不少的音韵创新,因此把EMH归到那个小支去,应该是没有问题的。'福建小支'的成员包括漳州话、大田话和龙岩话等。另一方面,EMH并非完全没有混杂的成分,这可由若干罕见于'福建小支'的音变,以及个别含'闽南语北支'特点的拼写反映出来。
