Whether human-induced activities could change the gradient pattern of coastal land use along the sea-land direction:a case study in Manila Bay,Philippines

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.

Manila clam Venerupis philippinarum as a biomonitor to metal pollution

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.

Larval and Juvenile Growth Performance of Manila Clam Hybrids of Two Full-Sib Families

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.

Identification of Perkinsus-like parasite in Manila clam, Ruditapes philippinarum using DNA molecular marker at ITS region

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.

Effect of Epinephrine on the Settlement and Metamorphosis of Manila Clam Larvae

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.

基于OpenStack Manila的多租户多协议共享存储平台

基于OpenStack Manila的多租户多协议共享存储平台,构建一个可支持多租户、多文件传输协议的共享存储平台。用户不仅可以使用新的存储卷创建共享存储,还可将已存有数据的存储卷做成共享存储;平台可支持多种文件传输协议,将共享存储挂载到不同类型的操作系统;平台支持水平扩展和高可用,用户可根据业务要求,部署多节点数量。平台满足从已有数据盘创建共享存储并挂载不同类型的操作系统的需求。

Annual Variations of Biogenic Element Contents of Manila Clam(Ruditapes philippinarum) Bottom-Cultivated in Jiaozhou Bay, China

Manila clam （Ruditapes philippinarum） was monthly sampled from its benthic aquaculture area in Jiaozhou Bay from May 2009 to June 2010.The annual variations of major elemental composition,organic content,fatness and element ratio of Manila clam were examined.The element removal effect of clam farming in Jiaozhou Bay was analyzed based on natural mortality and clam harvest.The results indicated that the variation trend of carbon content in shell （Cshell） was similar to that in clam （Cclam）.Such a variation was higher in summer and autumn than in other seasons,which ranged from 9.10±0.13 to 10.38 ± 0.09 mmol g^-1 and from 11.28 ±0.29 to 12.36±0.06 mmol g 1,respectively.Carbon content of flesh （Cflnesh） showed an opposite variation trend to that of shell in most months,varying from 29.42 ± 0.05 to 33.64 ± 0.62 mmol g^-1.Nitrogen content of shell （Nshell） and flesh （Nflesh） changed seasonally,which was relatively low in spring and summer.Nshell and Nflesh varied from 0.07 ±0.009 to 0.14±0.009 mmol g^-1 and from 5.46 ± 0.12 to 7.39 ± 0.43 mmol g^-1,respectively.Total nitrogen content of clam ranged from 0.50 ± 0.003 to 0.76 ± 0.10 mmol g^-1 with a falling tend except for a high value in March 2010.Phosphorus content of clam （Nclam） fluctuated largely,while phosphorus content of shell （Pshell） was less varied than that of flesh （Pflesh）.Pshell varied from 0.006±0.001 to 0.016±0.001 mmol g^-1; while Pflesh fluctuated between 0.058±0.017 and 0.293±0.029mmolg^-1.Pclam ranged from 0.015±0.002 to 0.041 ±0.006mmolg^-1.Carbon and nitrogen content were slightly affected by shell length,width or height.Elemental contents were closely related to the reproduction cycle.The removal amounts of carbon,nitrogen and phosphorus from clam harvest and natural death in Jiaozhou Bay were 2.92× 10^4t,1420t and 145 t,respectively.The nutrient removal may aid to reduce the concentrations of nitrogen and phosphorus,the main causes of eutrophication,and to maintain the ecosystem health of Jiaozhou Bay.

Impact of seawater acidification on shell property of the Manila clam Ruditapes philippinarum grown within and without sediment

Although the impact of ocean acidification on marine bivalves has been previously investigated under mainly controlled laboratory conditions,it is still unclear whether the impact of acidification on sediment-burrowing species differs between those within or without sediment.In order to fill this gap in our knowledge,we compared shell properties of the infaunal Manila clam(Ruditapes philippinarum)exposed to three pH concentrations(7.4,7.7,and 8.0),within and without sediments.In the first experiment(140 d),clams were exposed to seawater in an acidification system without sediment.A decrease in shell weight corresponding to the increase in dissolution rate was observed in the group ofpH 7.4,at which shell color disappeared or whitened.SEM observations confirmed the changes of the external shell surface.In the second experiment(170 d),sediment was placed at the bottom of each exposure chamber.The effects were found obvious in shell dissolution rate and shell color in the shell specimens exposed to overlying seawater but not found in the shell specimens exposed to sediment.Although the experimental period was longer in the second experiment,shell specimens in the first experiment were more seriously damaged than those in the second experiment under acidic seawater conditions.Our results,in relation to the defense function of the shell,show that marine bivalves in burrowing behavior are more adaptable to seawater acidification than those who do not burrow into sediment.

Numerical Study on the Effect of the Manila Seismic Tsunami on the Guangdong Coast——The Nonlinear Effects of Tides and Tsunamis

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.

Growth Performance of Larval and Juvenile Manila Clam(Ruditapes philippinarum) from Divergently Selected Individuals of a Full-Sib Family

Abstract In this study, the method of divergent selection was employed to test the larval and juvenile growth performance within a full-sib family of Manila clam Ruditapes philippinarum. The 10% largest and 10% smallest clam individuals （on the basis of shell length） of a full-sib family were selected as parents for the fast and slow growing lines, respectively. The difference in shell length was significant among the three lines （fast, control, and slow） tested. The sequence of shell length were fast line 〉 control line 〉 slow line. The responses to selection, realized heritability, and genetic gain were 0.06%-0.81%, 0.04%-0.47% and 0.58%-18.89% in the fast direction, respectively; and were 0.14%-1.27%, 0.08%-0.73%, and 0.31%-49.03% in the slow direction, respectively. The re- suits suggested that there was a large portion of additive genetic variance affecting the growth in the full-sib family. Selection in the fast direction within the full-sib family would greatly improve the growth ofR. philippinarum.

Fabrication of Manila Hemp Fiber Reinforced Cross Ply Biodegradable Composites and Their Tensile Properties

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.

Provenance of sediments in the northern Manila Trench:An assessment from detrital zircon geochronology

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.

震源运动学破裂过程对马尼拉俯冲带潜在海啸的影响研究

提高对马尼拉俯冲带海啸生成机制的认识对研究我国东南沿海地区海洋防灾减灾具有重要意义。目前,大型俯冲带震源破裂的运动过程对海啸生成的影响逐渐受到关注,但震源运动学破裂过程对马尼拉俯冲带潜在海啸的影响尚未明确。基于马尼拉俯冲带的典型破裂模型,对不同破裂速度和方向设定的海啸情景开展数值模拟,评估分析破裂速度和方向对海啸波传播特征的影响。结果表明:破裂方向相同时,破裂速度越慢,海啸波到时越晚,峰值波高越小;破裂速度相同时,与不考虑破裂运动过程的模拟结果相比,破裂前方的场点峰值波高更大,距离初始破裂位置更近的场点到时越早;不同设定情境下,沿海场点的海啸波到时最大相差10 min左右,峰值波高最大值约为最小值的1.5倍。

马尼拉俯冲带地震海啸对华南沿海的概率性灾害影响

马尼拉俯冲带地震作为高风险海啸源对华南沿海地区构成严重威胁,开展概率性海啸灾害评估有助于全面了解马尼拉俯冲带地震海啸能量的时空分布规律并指导南海海岸工程的设计及建设。本文针对马尼拉俯冲带五项不确定性参数的概率分布展开研究,应用逻辑树法设计地震海啸样本集,使用非静压海啸数值模型对所有样本情景进行传播模拟,最后通过概率计算得到南海海域的海啸最大波幅超越概率曲线,并绘制了100年和500年回归周期下南海概率性海啸最大波幅的空间分布图。研究发现,100年一遇的海啸对中国大陆南部沿海影响较低,潜在海啸的最大波幅最高可达0.7 m,危险等级不超过Ⅱ级;500年一遇的海啸可能会对我国南部沿岸城市(如汕头、汕尾、香港地区和澳门地区等)造成最大波幅为2.5 m左右的Ⅲ级海啸威胁,中沙群岛和西沙群岛沿岸可能出现最大波幅为3.1 m的海啸活动,东沙群岛受到最大波幅有可能超过4.0 m的海啸威胁,这些地区海啸危险等级均高达Ⅳ级。

马尼拉海沟增生楔北部海域天然气水合物成藏机制及其潜在地质灾害风险

天然气水合物由于其巨大的资源潜力而受到广泛关注,但以往研究多集中在南海北部海域被动陆缘,对南海东部主动陆缘的天然气水合物关注相对较少。本文基于南海东北部马尼拉海沟主动陆缘区多道地震剖面分析,识别出似海底反射、振幅空白带、极性反转等典型天然气水合物识别标志以及逆断层、泥底辟等流体运移通道。台湾西南部造山带是马尼拉海沟增生楔的延伸,其泥火山伴生气以CH_(4)为主,少部分表现出高氮异常;其地球化学特征表明,该区天然气主要为热解成因的成熟烃类气,且主要是新近纪巨厚海相沉积烃源岩的贡献。分析认为,其成因是板块俯冲运动将深部烃类物质带入增生楔内,并形成高压环境,热成因烃类气体沿着泥底辟和逆断层等通道向上运移,在运移过程中部分天然气被微生物逐步改造,并混合原位生物气。热成因和生物成因甲烷最终在合适的稳定带内混合;形成以热成因为主,部分具有生物成因特征的逆冲推覆控藏混合气源天然气水合物藏。另外,随着外界环境的变化及俯冲运动的持续活动,天然气水合物的稳定条件遭到破坏而发生分解渗漏,可能引起滑坡,在对本区天然气水合物资源进一步的勘探开发过程中必须注意其潜在地质灾害风险。

高炉渣矿质元素对马尼拉草生长的影响

高炉渣是炼铁过程中产生的副产品,含有丰富Ca、Si、Mg、Fe等植物生长所需的矿质元素,在农林领域应用前景广阔。以高炉渣为研究对象,将高炉渣与泥炭土混合后开展淋溶实验和马尼拉草盆栽实验,通过测定高炉渣与泥炭土混合物淋溶液元素溶出浓度,确定马尼拉草生物量、株高、根系形态等植物生长指标和叶绿素、可溶性糖和可溶性蛋白含量等生化指标,研究了高炉渣对土壤-马尼拉草生态系统的影响。结果表明:添加少量高炉渣会提升土壤中Si、Fe、Mn的溶出浓度,但当高炉渣添加量高于4%时,会造成土壤碱化、贫钾、贫磷和富铝化。当高炉渣添加量不高于4 wt.%时,土壤中高炉渣的加入会促进马尼拉草根系的发育,提高叶绿素、可溶性糖和可溶性蛋白的含量,进而促进其生长。与对照组相比,土壤中高炉渣添加量为4%时,马尼拉草的株高和生物量分别提升了19%和35%,可起到较好的固碳释氧效果。

First molluscan antimicrobial peptide hydramacin in Manila clam:molecular characterization and expression analysis

Objective:To investigate molecular characterization and the immune responses of Manila clam hydramacin(Rp-hdmc).Methods:cDNA sequence of hydramacin was isolated from Manila clam transcriptome database.Molecular characterization of hydramacin cDNA was performed by BLAST and SWISS-MODEL bioinformatics programs.Tissue-specific expression and transcriptional regulation after Vibrio tapetis challenge was done by quantitative real time PCR.Results:Rp-hdmc has 291 bp open reading frame(ORF),encoding 97 amino acids with a mature hydramacin consisting of 77 amino acid residues.In un-challenged clam,Rp-hdmc was constitutively expressed in all tested tissues and the highest expression level was detected in gill.After pathogenic bacteria Vibrio tapetis challenge,Rp-hdmc mRNA was up-regulated in gill and hemocytes.Conclusions:We identified hydramacin cDNA(Rp-hdmc)from mollusk Manila clam that shows the characteristic features of hydramacin sequence.It has eight cysteine residues with four disulfide linkages,three helices and two β-strands in secondary structure.Expression results after V.tapetis challenges suggest that Rp-hdmc is involved in immune response against pathogenic bacteria.

Indentation tectonics in the accretionary wedge of middle Manila Trench

Based on the multibeam morpho-tectonic analysis of the Manila Trench accretionary wedge and its indentation tectonics and the contrasting researches with other geological and geophysical data, three tectonic zones of the wedge are established, faulting features, tectonic distri- bution and stress mechanism for the indentation tectonics are analyzed, oblique subduction along Manila Trench with convergent stress of NW55° is presented, and the relation- ship of the ceasing of Eastern Subbasin spreading of South China Sea Basin to the formation of subduction zone of Ma- nila Trench is discussed. By the model analysis and regional research, it is found that the seamount subduction along Ma- nila Trench does not lead to the erosion of the accretionary wedge and the oblique subduction actually is a NWW- trending obduction of Luzon micro-plate that results from the NWW-trending displacement of the Philippine Sea plate.

16~19世纪海上丝绸之路视域下墨西哥瓷器的中国风

16~19世纪海上丝绸之路贸易中,中国瓷器通过马尼拉大帆船影响到墨西哥乃至美洲,对墨西哥的审美及其身份形成所起的重要作用一直被忽略。本文从物质文化研究的领域出发,对中国瓷器的传播动因、媒介、方式、路径和效果问题进行梳理、比较和系统研究。此段历史的研究对增强文化自信,开展文化外交具有一定的现实意义。

南海海盆俯冲消亡机制:马尼拉海沟俯冲起始的启示

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