Growth of marine bacteria and ammonium regeneration from substrates in different C:N ratios

Natural assemblages of marine bacteria were chosen in a batch culture experiments. The impact of varying nitrogen substrate concentrations and the substrate C：N ratios （C：Ns） on the bacterial C：N ratio （C：NB）, the bacterial growth efficiency （BGE） and ammonium regeneration was mainly examined. The C：Ns ratios varied from 5：1 （carbon limitation） to 40：1 （nitrogen limitation） with varying combinations of glucose and NO3. The C：NB ratio had positive relationship with the C：Ns ratio （r=0.93, n=8）, whose value was 3.77 when the C：Ns ratio was 5：1 but increased to 6.47 when the C：Ns ratio was 40：1. These results indicate that the C：NB ratio is a potential diagnostic tool for determining the bacterial growth in natural waters controlled by either, carbon or nitrogen. BGE decreased with the declining nitrate concentration and negatively related to C：N8 （r=-0.51, n=8）. The average value of BGE was 0.20. This value was a little lower than other reports, which could be induced by the nitrogen source used in our experiments. Finally, regeneration time of ammonium delayed with the increasing C：Ns ratio, which indicates that there were different metabolism mechanisms when bacterial growth was limited by carbon source and nitrogen source.

Ecological functions of ciliated protozoa in marine ecosystem： effects of ammonium on the population growth of Euplotes vannus

The effects of ammonium on the population growth of the marine ciliate, Euplotes vannus, were examined using ecotoxicological method, h is showed that ammonium exerts inhibitory effects on the growth of the ciliate populations in a concentration-dependent way. Statistical analvsis reveals that the population growth dynamics exposed to ammoniunt-N concentration over 100mg/L are significantly different from that in the control at P 〈 0.05 level. Linear regression determined that the 24h, 36h, 48h, 60h, 72h and 84h IC50 values of ammonium-N are 19.68, 201.51, 167.49, 47.86, 50.43 and 43.11 concentration over 100mg/L, respectively （ P 〈 0.05; pH 8.2; salinity 28 ppt; temperature, 25℃ ）. The results indicate that the tolerance to ammonium in E. vannus is considerably higher than that of the larvae or juveniles of some metozoa, such as cuhured prawns and oysters. Therefore, it is believed that the high tolerance to ammonium is necessary for eiliated protozoa to play positive roles in maintaining and improving water quality in marine ecosystems, especially in the intensive aquacuhure waters with high-level ammonium. In addition, the correlation between /C50 values and exposure time was discussed.

Study on Growth Laws of Marine Science and Technology Talents Based on the Perspective of Big Data

Based on the perspective of big data,the growth characteristics of marine science and technology talents were analyzed,and the growth of marine science and technology talents was divided into five periods:study period,adaptation period,growth period,promotion period and stability period.Moreover,some suggestions for the training of marine science and technology talents were proposed from the aspects of students,families,schools and society.

Experimental studies on dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) production by four marine microalgae

The production of dimethylsulfide （DMS） and dimethylsulfoniopropionate （DMSP） by marine microalgae was investigated to elucidate more on the role of marine phytoplankton in ocean-atmosphere interactions in the global biogeochemical sulfur cycle.Axenic laboratory cultures of four marine microalgae–Isochrysis galbana 8701,Pavlova viridis,Platymonas sp.and Chlorella were tested for DMSP production and conversion into DMS.Among these four microalgae,Isochrysis galbana 8701 and Pavlova viridis are two species of Haptophyta,while Chlorella and Platymonas sp.belong to Chlorophyta.The results demonstrate that the four algae can produce various amounts of DMS（P）,and their DMS（P） production was species specific.With similar cell size,more DMS was released by Haptophyta than that by Chlorophyta.DMS and dissolved DMSP （DMSPd） concentrations in algal cultures varied significantly during their life cycles.The highest release of DMS appeared in the senescent period for all the four algae.Variations in DMSP concentrations were in strong compliance with variations in algal cell densities during the growing period.A highly significant correlation was observed between the DMS and DMSPd concentrations in algal cultures,and there was a time lag for the variation trend of the DMS concentrations as compared with that of the DMSPd.The consistency of variation patterns of DMS and DMSPd implies that the DMSPd produced by phytoplankton cells has a marked effect on the production of DMS.In the present study,the authors’ results specify the significant contribution of the marine phytoplankton to DMS（P） production and the importance of biological control of DMS concentrations in oceanic water.

Decumbenones A–C from marine fungus <i>Aspergillus sulphureus</i>as stimulators of the initial stages of development of agricultural plants

The effect of decumbenones A (1), B (2) and C (3) from the marine-derived strain of the fungus Aspergillus sulphureus on the growth of seedling roots of buckwheat, wheat, barley and corn at the concentration range 10﹣5 - 10﹣18 M was studied. It was shown that decumbenone B had a stimulatory effect on the growth of seedling roots of buckwheat, decumbenone A—on the growth of seedling roots of spring soft wheat, decumbenone C—on the growth of seedling roots of spring barley, decumbenone A, B and C —on the growth of seedling roots of corn. The stimulatory effect for some substances was shown at ultra-low concentrations 10﹣12 - 10﹣18 M. It is possible to recommend decumbenones A, B and C for studying in field conditions as growth factors of buckwheat, wheat, barley and corn.

Understanding the function of the tumor microenvironment,and compounds from marine organisms for breast cancer therapy

The pathology and physiology of breast cancer(BC),including metastasis,and drug resistance,is driven by multiple signaling pathways in the tumor microenvironment(TME),which hamper antitumor immunity.Recently,long non-coding RNAs have been reported to mediate pathophysiological developments such as metastasis as well as immune suppression within the TME.Given the complex biology of BC,novel personalized therapeutic strategies that address its diverse pathophysiologies are needed to improve clinical outcomes.In this review,we describe the advances in the biology of breast neoplasia,including cellular and molecular biology,heterogeneity,and TME.We review the role of novel molecules such as long non-coding RNAs in the pathophysiology of BC.Finally,we provide an up-to-date overview of anticancer compounds extracted from marine microorganisms,crustaceans,and fishes and their synergistic effects in combination with other anticancer drugs.Marine compounds are a new discipline of research in BC and offer a wide range of anti-cancer effects that could be harnessed to target the various pathways involved in BC development,thus assisting current therapeutic regimens.

新常态下海洋经济新旧动能转换测评与影响因素分析

海洋经济新旧动能转换是坚持新发展理念、深化海洋供给侧结构性改革、推动海洋经济转型升级的重要标志,对实现海洋经济高质量发展有重要意义。基于海洋经济新旧动能转换内涵与机理,从需求侧、供给侧、结构转换动能三个维度构建综合评价指标体系;运用主客观赋权法、TOPSIS模型和核密度估计,对中国2006—2020年海洋经济新旧动能转换进行测算与评价;引入GWR模型探讨中国沿海11个省份各影响因素的空间异质性。结果表明,中国海洋经济新旧动能转换综合指数总体呈现波动上升趋势。其中,结构转换动能提升最为显著,需求侧动能总体呈波动上升态势,供给侧动能转换指数整体发展水平不高,对海洋经济新旧动能转换贡献力度较小;2006—2020年,中国海洋经济新旧动能转换指数差异呈先缩小后扩大继而再缩小的变化过程;陆域经济发展水平、海洋产业结构水平、海洋科技创新水平对海洋经济动能转换的提升起正向作用,各因素影响效应具有空间异质性。

GaR视角下海洋产业结构升级、科技创新与海洋经济高质量发展

海洋产业结构升级是实现海洋经济高质量发展的关键,其能否促进海洋经济增长是海洋产业结构高质量转型的着力点。文章从在险增长视角,以我国沿海11个省(自治区、直辖市)为样本,通过构建面板分位数回归模型,研究海洋产业结构升级对GOP分布的影响,着重分析海洋经济下行风险和上升潜力的变化趋势。实证结果显示:海洋产业结构升级与短、中、长期海洋经济增长正相关,显著促进海洋经济高质量发展,且不同经济增长水平下,该促进作用具有异质性。而科技创新能够正向调节海洋产业结构升级与海洋经济增长的关系,助力海洋产业结构升级,降低中、短期海洋经济下行风险,并提高中、长期海洋经济上升潜力,发挥出海洋产业升级对海洋GaR的正向促进作用。因此,有关部门应完善海洋科技创新体系,加快推进海洋产业结构升级,对海洋经济高质量发展具有重要的意义。

海岛地区碳排放脱钩效应及驱动因素研究——基于Tapio脱钩指标和LMDI分解模型

海岛作为陆海复合生态系统的典型地带,通过科学测度海岛的碳排放强度及其脱钩效应,可以为海岛低碳绿色发展模式确定和实施路径选择提供依据。基于IPCC碳排放核算方法及线性插值法,构建海岛地区碳排放测度模型,以中国12个县级海岛为案例区,测算其2000—2020年的碳排放规模,采用Tapio脱钩模型及莫兰指数空间自相关法揭示其脱钩状态和空间格局演化特征,并运用LMDI分解方法探讨碳排放的影响因素。结果表明:(1)海岛县域碳排放总量与经济发展均呈增长趋势,经济发展与碳排放增长的速率相当;(2)海岛县域碳排放量多种脱钩类型共存的特征突出,弱脱钩成为主导性脱钩状态,低碳经济仍有很大的发展空间;(3)海岛县域脱钩效应存在显著的全局空间正相关性,空间集聚特征显著,崇明区成为典型脱钩优势区,嵊泗县、长岛县脱钩状态欠佳,呈现脱钩不稳定与区域不均衡的状态;(4)碳排放强度、产业结构、人口规模对碳排放具有正效应,而财政政策、经济发展具有负效应,且经济发展效应保持平稳状态。基于海岛县的脱钩态势,提出了通过优化产业结构、加大财政支持等差异化政策措施,助推“双碳”目标。

海洋产业集聚、科技创新与海洋经济增长

海洋产业作为沿海地区重要的产业依托,其集聚程度和类型已成为影响我国海洋经济发展的重要因素。基于我国11个沿海地区2006-2018年的面板数据,采用区位熵法测算海洋产业集聚情况,并实证考察了海洋产业集聚、科技创新对区域海洋经济发展的影响。研究发现:(1)海洋产业集聚和科技创新均能显著促进我国海洋经济增长,且产业集聚对海洋经济发展的推动作用有11.37%是通过促进科技创新来间接实现的。(2)不同海洋产业集聚类型对区域海洋经济发展的作用具有明显差异,海洋第一、二产业集聚水平的提高并不能对海洋经济产生促进作用,而提高第三产业的集聚水平可以更好地促进海洋经济发展。此外,海洋产业集聚对海洋经济发展的影响也存在明显的区域异质性。为此,沿海各地区应致力于提升海洋产业集聚水平、增强科技创新投入力度,根据自身实际情况实行差异化政策,优化海洋产业结构,促进海洋经济高质量发展。

海洋产业集聚、海洋资源禀赋与海洋经济增长

海洋产业的发展对海洋资源具有高度依赖性,在建设“海洋强国”背景之下,研究海洋产业集聚、海洋资源禀赋与海洋经济增长具有重要意义。文章基于2006—2019年我国沿海11个省(自治区、直辖市)的数据,利用固定效应模型实证检验海洋产业集聚与海洋经济增长的关系基础上,分析海洋资源禀赋的调节效应,最后进一步利用空间杜宾模型分析海洋产业集聚对海洋经济增长的空间溢出效应。得出如下结论:海洋产业集聚与沿海地区的海洋经济增长之间存在“倒U”型关系;通过调节效应检验可知,海洋资源禀赋在海洋产业集聚影响海洋经济增长的过程中发挥调节效应,海洋资源禀赋既能够通过促进实物资本投资、降低交易成本等产生“资源福音”,也能挤出海洋产业科技创新与人力资本投资从而产生“资源诅咒”;通过空间计量分析可知,海洋产业集聚对海洋经济增长具有显著的空间溢出特征。

Optimal effort,fish farming,and marine reserve in fisheries management

In this paper,we develop a bioeconomic model to determine an optimal wild catch harvest and freshwater commercial aquaculture production in a lake that uses cages or floating rafts.Although off-bottom aquaculture activities have less impact on the environment compared to on-bottom aquaculture,it has negative externalities.It takes away the fishing area and hence creates pressure in the open-access fishing ground.It also changes the nutrient and ecological composition of the environment.We recommend the implementation of a reserved area to minimize the impact of fishing and aquaculture activities.The reserve also helps in improving the habitat and restocking the fish population which is declining rapidly.We determine the optimal sizes of the aquaculture and reserve and the optimal effort level that maximizes social welfare.We illustrate our findings using numerical simulations and perform an analysis of the optimal solutions with respect to biological and economic parameters involved in the model.

海生物对渤海导管架平台结构性能的影响

为分析附着海生物对渤海导管架平台结构性能的影响,以渤海某典型4腿平台为例,结合渤海油田导管架附着海生物现场实测数据,针对不同海生物厚度及密度对导管架结构的影响进行敏感性分析,结果表明,平台所受环境荷载随海生物厚度增加而增大,而海生物密度对环境荷载不产生影响;结构杆件UC值和桩头力随海生物厚度及密度的增加而增大,节点UC值随海生物厚度增加而增大,随海生物密度增加几乎没有变化;平台前三阶自振周期随海生物厚度及密度的增加而小幅增大;疲劳寿命随海生物厚度的增加逐渐降低,且几乎不受海生物密度的影响;平台极限承载力不受海生物的影响。

基于改进FP-growth的海上群目标挖掘

海上目标状态呈现复杂多变的形势,须快速挖掘海上船舶的群组信息,以掌握海上目标态势。本文使用改进的FP-growth算法对海上船舶进行数据挖掘,使用基于时空分割的方法划分目标区域,挖掘频繁项集。首先清洗原始数据得到有效数据;其次使用线性插值方法处理船舶的轨迹方便后续计算;然后使用FP-growth算法,构建生成FP-tree;最后得到频繁项集,挖掘海上船舶群组信息。针对基于项集划分关联分析查找效率低的问题,本文使用基于Hash表拆分数据库和结点交换的方法挖掘频繁项集,在内存占用和时间消耗两方面比较算法的效率。使用AIS数据集进行验证,在给定的置信度和支持度下挖掘目标群组信息,验证改进算法的高效率。

Isolation, characterization and implications of the bacterial communities associated with established cultures of Chattonella marina(Raphidophyceae) and Skeletonema costatum(Bacillariophyceae)

Cultivable bacteria coexisting in the cultures of two microalgal species, Chattonella marina(Raphidophyceae)and Skeletonema costatum(diatom, Bacillariophyceae), which have been maintained in the laboratory for several years, were examined in this study. Forty-eight and thirty-four cultivable bacterial strains were isolated from different growth stages of C. marina and S. costatum cultures, respectively. A total of twelve unique bacterial phylotypes were isolated. These bacterial phylotypes belonged to Alphaproteobacteria, Gammaproteobacteria,Bacteroidetes, and Actinobacteria. Alphaproteobacteria predominated in phycospheres of both microalgae, and Rhodobacteraceae was the most common family. Bacterial phylotypes were more diversified in cultures of S.costatum than in those of C. marina. Bacterial concentrations increased remarkably after the late stationary phase of C. marina, which might account for the decline in algal cells. One phylotype of S. costatum-associated bacteria had inhibitory effects on Chaetoceros curvisetus(Bacillariophyceae). However, most bacterial phylotypes from cultures of C. marina showed significant inhibition of the growth of C. curvisetus. The results suggested that bacteria associated with C. marina might have some ecological roles in its competition with diatoms.

Size-Dependent Growth Rate of Nitzschia closterium at Different Concentrations of Petroleum Hydrocarbon

The maximum growth rate ofNitzschia elosterium at various concentrations of petroleum hydrocarbon was studied. The influence of petroleum hydrocarbon on cell size as a function of concentration was discussed. The relationship between maximum growth rate of Nitzschia closterium and cell median equivalent spherical diameter （MESD） was also carefully studied. The experi- mental results showed that the growth rate of Nitzschia elosterium was generally suppressed by petroleum hydrocarbon, which had greater effects at both low and high concentrations than at intermediate concentrations. No significant changes in cell size distribu- tion were observed during the growth period ofNitzsehia closterium. The Gaussian function could give a clear description of the cell size distribution ofNitzsehia closterium, and the MESD value ranged from 2.71 to 6.82 μm. The MESD decreased when the cell was exposed to petroleum hydrocarbon, and the reduction of cell MESD was much more significant at both relatively high and low hydrocarbon concentrations. The presence of petroleum hydrocarbon changed the relationship between μmax, and MESD from an allometric function to a U-shaped curve. When the MESD was below 5.07 μm,μmax decreased along with increased MESD, whereas when MESD was above 5.07 μm, μmax increased along with MESD, which deviated from the allometric model.

Investigating factors driving phytoplankton growth and grazing loss rates in waters around Peninsular Malaysia

In tropical waters where temperatures are relatively stable,we investigated whether the relationship between phytoplankton growth and grazing loss rate across diff erent habitats around Peninsular Malaysia can be attributed to its eutrophication states.We measured phytoplankton growth(μ)and grazing loss(g)rates in waters off Bachok Marine Research Station(BMRS),located northeast of Peninsular Malaysia.Chlorophyll-a(chl-a)concentration ranged from 2.90 to 15.78μg/L and was dominated by nanoand micro-phytoplankton(>2μm in size).Using the Landry and Hassett dilution method,μat BMRS ranged from 1.02 to 1.58/d whereas g varied from 0.07 to 0.88/d.Grazing accounted for 35%of the primary production at BMRS.A systematic review of available data in waters around Peninsular Malaysia,revealed howμfl uctuated over a wide range(0.01–1.80/d)and correlated with chl a distribution(R 2=0.181,P<0.001).However,the relationship was only signifi cant at<9μg/L chl a for mesotrophic waters and<16μg/L chl a for eutrophic waters.In contrast,g ranged from 0.00 to 1.01/d,and correlated withμat all locations.The g/μslope ranged from 19%to 84%,and was generally similar for waters around Peninsular Malaysia.However,all the g/μslopes had a positive y-intercept except for BMRS,and this seemed to suggest the availability of alternative prey supporting grazing at the other stations.

金融发展视角下海洋科技创新对海洋经济高质量发展的影响

随着海洋强国战略的实施,探究海洋科技创新对于海洋经济的影响成为实现海洋强国目标的重要推动力。文章基于2008—2019年中国11个沿海地区的面板数据,构建面板模型,在金融发展视角下探讨海洋科技创新对于海洋经济高质量发展的调节效应以及门槛非线性作用。结果表明:海洋科技创新对于海洋经济高质量增长具有显著促进作用;在海洋科技创新对海洋经济高质量发展的影响过程中,金融发展规模和效率表现出正向调节效应,而金融发展结构的调节效应暂不显著;在海洋科技创新作用于海洋经济高质量发展的过程中,金融发展规模存在双门槛效应以及最佳金融发展水平区间,金融发展结构和效率均存在单门槛效应,即当金融发展结构大于单一门槛值时,海洋科技创新对海洋经济高质量增长表现显著正向作用,当金融发展效率大于单一门槛值时,海洋科技创新对海洋经济高质量增长的促进作用增大。

海洋环境规制强度、健康人力资本与海洋经济增长

人口老龄化与海洋环境污染成为影响海洋经济增长的重要因素。文章基于代际交替模型和柯布-道格拉斯生产函数构建数理模型,将健康人力资本纳入模型,系统分析了海洋环境规制强度影响海洋经济增长的机理。在此基础上,选取2007—2019年我国沿海11个省(自治区、直辖市)的面板数据进行实证分析,结果表明:市场激励型海洋环境规制强度对海洋经济增长的促进作用明显弱于命令控制型海洋环境规制强度;命令控制型海洋环境规制强度与海洋经济增长之间存在“倒U型”特征;海洋环境规制强度的提升对健康人力资本积累有正向作用,两者联动作用进一步促进了海洋经济增长。因此,政府应采取动态化的海洋环境规制强度策略,完善健康保障制度,发挥健康人力资本效应;完善海洋环境治理体系,激发海洋环境规制市场活力,以保持海洋经济增长和海洋环境双赢。

科技创新、产业结构升级与海洋经济增长

随着我国海洋经济增速放缓,依靠简单的资源投入的粗放式生产方式已难以满足现代海洋产业的需要,而科技创新和产业结构升级既是拉动海洋经济增长的重要引擎,也是海洋产业发展的重要着力方向。文章选取2009—2021年全国海洋经济数据以及2009—2019年沿海11个省(自治区、直辖市)海洋产业经济数据,研究了海洋科技创新、海洋产业结构升级对海洋经济增长的独立影响以及协同影响,并建立了以产业结构升级为门槛变量,科技创新水平影响海洋经济发展的门槛模型。研究结果表明:科技创新、产业结构升级水平对海洋经济发展表现出显著的正向促进作用,同时这二者的协同效应也能够激励海洋经济水平的提升;科技创新促进海洋经济水平增长的过程中有门槛效应存在,跨过门槛值后,科技创新对海洋经济水平的促进影响程度会大幅度提升。