82 research outputs found
Relational Research between China’s Marine S&T and Economy Based on RPGRA Model
To make up the defect of the existing model, an improved grey relational model based on radian perspective (RPGRA) is put forward. According to the similarity of the relative change trend of time series translating traditional grey relational degree into radian algorithm within different piecewise functions, it greatly improves the accuracy and validity of the research results by making full use of the poor information in time series. Meanwhile, the properties of the RPGRA were discussed. The relationship between China’s marine S&T and marine economy is researched using the new model, so the validity and creditability of RPGRA are illustrated. The empirical results show that marine scientific and technological research projects, marine scientific and technological patents granted, and research funds receipts of the marine scientific research institutions have greater relationship with GOP, which indicates that they have more impact on China’s marine economy
Lagosinema tenuis gen. et sp. nov. (Prochlorotrichaceae, Cyanobacteria): a new brackish water genus from Tropical Africa
A novel filamentous, nonheterocytous cyanobacterium was isolated from Lagos Lagoon, Nigeria. The isolate was \u3c3.0 μm wide, untapered, with small rounded polar bodies (aerotopes or cyanophycin granules) visible at the crosswalls, and consequently fit the morphological description of Limnothrix planctonica. Although morphologically inseparable from that species, it was molecularly distant from that taxon, with genetic identities between the two taxa ranging 90.73–92.49%, a degree of separation typical of different genera. Both taxa, as well as Limnothrix rosea, are phylogenetically in the Prochlorotrichaceae, distant from the type species of Limnothrix, L. redekei, which is in the Pseudanabaenaceae. The isolate is herein described as Lagosinema tenuis gen. et sp. nov
Trend analysis of global stock market linkage based on a dynamic conditional correlation network
The paper analyses the trend of global stock market linkages via daily data of 51 stock indices spanning the period 22 July 2005 to 30 June 2016 which covers four regions: America, Europe, Asia Pacific and Africa. A dynamic conditional multivariate generalized autoregressive conditional heteroskedasticity (DCC-MVGARCH) approach was used to calculate dynamic correlation coefficient in order to construct the volatility networks. The methods of minimum spanning tree (MST) and low pass filter were for the first time applied to analyze the variable periodicity of the comovement. The original contribution of this paper is that contrary to previous works, financial events such as Quantitative Easing (QE) and Bailouts are accounted for rather than only crisis factors such as the 2008 financial crisis and the European Debt crisis. The main findings of the paper are as follows: (1) Financial crisis promotes and strengthens global stock markets linkage in the short run; (2) Linkage cycles post crisis are significantly short, due to the effect of monetary policy spillover effects caused by QE from developed to developing countries; and (3) European stock markets are the information transmission hub for global stock market. The research conclusions would be significant for both government to regulate markets as well as for investors to diversify risks
Temporal and spatial variations in nutrient stoichiometry and regulation of phytoplankton biomass in Hong Kong waters : influence of the Pearl River outflow and sewage inputs
Author Posting. © Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Marine Pollution Bulletin 57 (2008): 335-348, doi:10.1016/j.marpolbul.2008.01.020.In 2001, the Hong Kong government implemented the Harbor Area Treatment Scheme (HATS) under which 70% of the sewage that had been formerly discharged into Victoria Harbor is now collected and sent to Stonecutters Island Sewage Works where it receives chemically enhanced primary treatment (CEPT), and is then discharged into waters west of the Harbor. The relocation of the sewage discharge will possibly change the nutrient dynamics and phytoplankton biomass in this area. Therefore, there is a need to examine the factors that regulate phytoplankton growth in Hong Kong waters in order to understand future impacts. Based on a historic nutrient data set (1986-2001), a comparison of ambient nutrient ratios with the Redfield ratio (N:P:Si=16:1:16) showed clear spatial variations in the factors that regulate phytoplankton biomass along a west (estuary) to east (coastal/oceanic) transect through Hong Kong waters. Algal biomass was constrained by a combination of low light conditions, a rapid change in salinity, and strong turbulent mixing in western waters throughout the year. Potential stoichiometric Si limitation (up to 94% of the cases in winter) occurred in Victoria Harbor due to the contribution of sewage effluent with high N and P enrichment all year, except for summer when the frequency of stoichiometric Si limitation (48%) was the same as P, owing to the influence of the high Si in the Pearl River discharge. In the eastern waters, potential N limitation and N and P co-limitation occurred in autumn and winter respectively, because of the dominance of coastal/oceanic water with low nutrients and low N:P ratios. In contrast, potential Si limitation occurred in spring and a switch to potential N, P and Si limitation occurred in eastern waters in summer. In southern waters, there was a shift from P limitation (80%) in summer due to the influence of the N-rich Pearl River discharge, to N limitation (68%) in autumn, and to N and P co-limitation in winter due to the dominance of N-poor oceanic water from the oligotrophic South China Sea. Our results show clear temporal and spatial variations in the nutrient stoichiometry which indicates potential regulation of phytoplankton biomass in HK waters due to the combination of the seasonal exchange of the Pearl River discharge and oceanic water, sewage effluent inputs, and strong hydrodynamic mixing from SW monsoon winds in summer and the NE monsoon winds in winter.Financial support for this research was provided by the University Grants Council of Hong Kong AoE project (AoE/P-04/0401), and RGC project HKUST6478/05M. Support was also provided (to DMA) by U.S. National Science Foundation grants OCE-0402707 and OCE-0430724 and by NIEHS grant 1 P50-ES01274201
GlobalHAB : a new program to promote international research, observations, and modeling of harmful algal blooms in aquatic systems
From 1998 to 2013, the international community of scientists researching harmful algal blooms (HABs) in marine systems worked through the Intergovernmental Oceanographic Commission (IOC) of UNESCO and the Scientific Committee on Oceanic Research (SCOR) to better understand the ecological and oceanographic controls on these natural events that cause harm to humans and ecosystems. During this period, IOC and SCOR cosponsored the Global Ecology and Oceanography of Harmful Algal Blooms (GEOHAB) program to facilitate progress in HAB research, observations, and modeling. In 2016, building on the foundation provided by GEOHAB, IOC and SCOR launched a new HAB project design to extend research into freshwater systems and address several topics related to the effects of HABs on human society now and in a rapidly changing world
Research and Optimization of the Coupling and Coordination of Environmental Regulation, Technological Innovation, and Green Development
Environmental regulation and technological innovation play important strategic roles in green growth, and the three systems interact and influence each other. Herein, we used a comprehensive development level evaluation model for calculating the environmental regulation and technological innovation indices for 17 cities in Shandong Province. We used the slack-based measure-data envelopment analysis (SBM-DEA) model to measure green development efficiency. The coupling coordination degree model was used to determine the coordination of environmental regulation, technological innovation, and green development; we divided the cities into three systems: green economy lagging, environmental regulation lagging, and technological innovation lagging. We used grey correlation analysis to explore the factors affecting system development. Eastern coastal cities were better developed in the three systems and the degree of coupling and coordination, like Qingdao and Weihai, and the observed level of technological innovation development, a critical factor in the coordinated development of cities, was lowest in Shandong Province. The grey correlation analysis illustrated that the level of economic development and the level of foreign economic development impacts cities labeled green economy lagging; the impact of pollutant emissions is greater than pollution control expenditure in environmental regulation lagging cities; and the government’s attention and the cultivation and attraction of talent are foundational for technological innovation in lagging cities. Considering these factors, we make recommendations for the optimal development of cities and coordinated development of regions
Dynamics of nutrients and phytoplankton production in the Strait of Georgia estuary, British Columbia, Canada
Vertical profiles of temperature, salinity, NO3 and fluorescence were taken along
the Fraser River estuary and during time series at a station near the river mouth to
investigate entrainment of N0₃. In late spring and early summer, the N0₃-poorer
estuarine plume in the Strait of Georgia invaded the river with the advancing salt wedge on the flood tide in the middle layer between the river water and the N0₃-rich deep seawater, forming a three-layered system. Thus, upward entrainment of seawater into the riverine plume does not necessarily result in an upward entrainment of NO₃. More NO₃was entrained during the spring tide than during the neap tide; more during a higher river discharge than during a lower river discharge; and more under windy conditions than weak winds. Under all the conditions investigated, the contribution of the entrained N0₃to the surface layer was (2-11 times) more than that of the river-borne N0₃. The spring bloom was underway in early April, 1991 in the Strait of Georgia
estuary when it was interrupted by a wind event. Five days after the wind event,
phytoplankton biomass and production were even lower. During the next four days, they
gradually increased, and N0₃concentrations in the water column decreased slowly, which
indicated a slow recovery of the spring bloom. Higher zooplankton abundance were
responsible for the slow recovery.
The interaction between tidal ranges, river discharge and winds in the Strait during
spring controls the stability of the water column and hence, the development of the spring bloom. In 1988, nutrients, phytoplankton biomass, production and species composition during early June indicated the delayed spring bloom, due to a later initiation of the annual freshet and strong winds during March-mid-April. Whereas in 1992 (an El Nino year), an earlier initiation of the freshet and calm weather in March appeared to result in an earlier
onset of the spring bloom. The observations in all those years strongly suggest that
massive recruitment of the copepod Neocalanus plumchrus to the surface, due to its ontogenic migration from deep waters, regulates the development of the spring bloom. Thus, the interannual variability in the timing of the spring bloom determines the matching (phasing) between phytoplankton and zooplankton.Science, Faculty ofEarth, Ocean and Atmospheric Sciences, Department ofGraduat
Short-term interaction between nitrate and ammonium uptake for cells of a marine diatom grown under different degrees of light limitation
The short-term interaction between nitrate and ammonium uptake was examined for a marine diatom, Thalassiosira pseudonana, grown in the continuous turbidostat cultures under different degrees of light limitation. Nitrate uptake in the absence and in the presence of ammonium and ammonium uptake in the absence and in the presence of nitrate were measured during a 6 min time course after a solution of both nitrate and ammonium was passed across the cells trapped on the filter.
It was found that the interaction between nitrate and ammonium uptake occurred immediately and continued for the remainder of the time course. The effect of light on the interaction was apparent. In the less light-limited cultures, nitrate uptake was depressed by ammonium. In contrast, in the most light-limited culture, the depression of nitrate uptake by ammonium disappeared. Ammonium uptake was dependent on the degree of light limitation of the cultures. For all the cultures, ammonium uptake was initially enhanced and then declined with time. However, only the initial (1 min) enhanced uptake of ammonium was suppressed by the presence of nitrate, and the subsequent ammonium uptake rate was unaffected. Possible explanations and the ecological significance of the interaction are discussed.Science, Faculty ofEarth, Ocean and Atmospheric Sciences, Department ofGraduat
Lack of Seasonal Hypoxia in Spite of High Nitrogen Enrichment in the Pearl River Estuary and Adjacent Coastal Waters
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