Sodium current of neurosecretory cells in the eyestalk from the shrimp Penaeus japonicus

The properties of the inward current of medulla terminalis-X-organ (MTXO) cells isolated from the Penaeus japonicus eyestalk were studied with the whole-cell clamp technique in the presence of Ca2+ and K+ channel blockers. The inward currents had a threshold at about -50 mV and peaked at -10 mV. The reversed potential (V-rev) was very close to V-Na, the theoretical Nernst equilibrium potential for Na+. V-rev followed V-Na when the external Na+ concentration was varied and the currents were entirely suppressed by 30 nM tetrodotoxin (TTX), indicating that it was carried by Na+. The smooth line of concentration-dependent inhibition of sodium currents by TTX represented the best. t with the Hill equation, yielding an IC50 of 2.1 +/- 0.1 nM. The values of the half-maximal activation voltage V-h were -20.6 +/- 0.5 and -19.3 +/- 0.5 mV, respectively, in the absence and presence of 2 nM TTX. TTX had no significant effect on the voltage dependence of steady-state activation and inactivation of I-Na. Taken together, the results suggest that the inward current recorded under our experimental conditions was carried by sodium ions. owing through fast voltage-dependent Na+ channels. (C) 2009 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.National Natural Science Foundation of China [30300269]; Technical Innovation Project of Fujian [2003J018

Impact of the Kuroshio intrusion on the nutrient inventory in the upper northern South China Sea: insights from an isopycnal mixing model

Based on four cruises covering a seasonal cycle in 2009-2011, we examined the impact of the Kuroshio intrusion, featured by extremely oligotrophic waters, on the nutrient inventory in the central northern South China Sea (NSCS). The nutrient inventory in the upper 100m of the water column in the study area ranged from similar to 200 to similar to 290 mmol m(-2) for N+N (nitrate plus nitrite), from similar to 13 to similar to 24 mmol m(-2) for soluble reactive phosphate and from similar to 210 to similar to 430 mmol m(-2) for silicic acid. The nutrient inventory showed a clear seasonal pattern with the highest value appearing in summer, while the N+N inventory in spring and winter had a reduction of similar to 13 and similar to 30 %, respectively, relative to that in summer. To quantify the extent of the Kuroshio intrusion, an isopycnal mixing model was adopted to derive the proportional contribution of water masses from the SCS proper and the Kuroshio along individual isopycnal surfaces. The derived mixing ratio along the isopycnal plane was then employed to predict the genuine gradients of nutrients under the assumption of no biogeochemical alteration. These predicted nutrient concentrations, denoted as N-m, are solely determined by water mass mixing. Results showed that the nutrient inventory in the upper 100m of the NSCS was overall negatively correlated to the Kuroshio water fraction, suggesting that the Kuroshio intrusion significantly influenced the nutrient distribution in the SCS and its seasonal variation. The difference between the observed nutrient concentrations and their corresponding Nm allowed us to further quantify the nutrient removal/addition associated with the biogeochemical processes on top of the water mass mixing. We revealed that the nutrients in the upper 100m of the water column had a net consumption in both winter and spring but a net addition in fall.Based on four cruises covering a seasonal cycle in 2009-2011, we examined the impact of the Kuroshio intrusion, featured by extremely oligotrophic waters, on the nutrient inventory in the central northern South China Sea (NSCS). The nutrient inventory in the upper 100m of the water column in the study area ranged from similar to 200 to similar to 290 mmol m(-2) for N+N (nitrate plus nitrite), from similar to 13 to similar to 24 mmol m(-2) for soluble reactive phosphate and from similar to 210 to similar to 430 mmol m(-2) for silicic acid. The nutrient inventory showed a clear seasonal pattern with the highest value appearing in summer, while the N+N inventory in spring and winter had a reduction of similar to 13 and similar to 30 %, respectively, relative to that in summer. To quantify the extent of the Kuroshio intrusion, an isopycnal mixing model was adopted to derive the proportional contribution of water masses from the SCS proper and the Kuroshio along individual isopycnal surfaces. The derived mixing ratio along the isopycnal plane was then employed to predict the genuine gradients of nutrients under the assumption of no biogeochemical alteration. These predicted nutrient concentrations, denoted as N-m, are solely determined by water mass mixing. Results showed that the nutrient inventory in the upper 100m of the NSCS was overall negatively correlated to the Kuroshio water fraction, suggesting that the Kuroshio intrusion significantly influenced the nutrient distribution in the SCS and its seasonal variation. The difference between the observed nutrient concentrations and their corresponding Nm allowed us to further quantify the nutrient removal/addition associated with the biogeochemical processes on top of the water mass mixing. We revealed that the nutrients in the upper 100m of the water column had a net consumption in both winter and spring but a net addition in fall

Modeling the Total Allowable Area for Coastal Reclamation : a case study of Xiamen, China

Author Posting. © The Author(s), 2013. 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 Ocean & Coastal Management 76 (2013):38-44, doi:10.1016/j.ocecoaman.2013.02.015.This paper presents an analytical framework to estimate the Total Allowable Area for Coastal Reclamation (TAACR) to provide scientific support for the implementation of a coastal reclamation restriction mechanism. The logic of the framework is to maximize the net benefits of coastal reclamation subject to a set of constraints. Various benefits and costs, including the ecological and environmental costs of coastal reclamation, are systematically quantified in the framework. Model simulations are developed using data from Tongan Bay of Xiamen. The results suggest that the TAACR in Tongan Bay is 5.67 km2, and the area of the Bay should be maintained at least at 87.52 km2.The study was funded by the National Oceanic Public Welfare Projects (No. 201105006) and the Fujian Natural Science Foundation (No. 2010J01360

Sources and accumulation of organic carbon in the Pearl River Estuary surface sediment as indicated by elemental, stable carbon isotopic, and carbohydrate compositions

Organic matter in surface sediments from the upper reach of the Pearl River Estuary and Lingdingyang Bay, as well as the adjacent northern South China Sea shelf was characterized using a variety of techniques, including elemental (C and N) ratio, bulk stable organic carbon isotopic composition (delta C-13), and carbohydrate composition analyses. Total organic carbon (TOC) content was 1.21 +/- 0.45% in the upper reach, down to 1.00 +/- 0.22% in Lingdingyang Bay and to 0.80 +/- 0.10% on the inner shelf and 0.58 +/- 0.06% on the outer shelf. delta C-13 values ranged from -25.1 parts per thousand to -21.3 parts per thousand in Lingdingyang Bay and the South China Sea shelf, with a trend of enrichment seawards. The spatial trend in C/N ratios mirrored that of delta C-13, with a substantial decrease in C/N ratio offshore. Total carbohydrate yields ranged from 22.1 to 26.7 mg (100 mg OC)(-1), and typically followed TOC concentrations in the estuarine and shelf sediments. Total neutral sugars, as detected by the nine major monosaccharides (lyxose, rhamnose, ribose, arabinose, fucose, xylose, galactose, mannose, and glucose), were between 4.0 and 18.6 mg (100 mg OC)(-1) in the same sediments, suggesting that significant amounts of carbohydrates were not neutral aldoses. Using a two end-member mixing model based on delta C-13 values and C/N ratios, we estimated that the terrestrial organic carbon contribution to the surface sediment TOC was ca. 78 +/- 11% for Lingdingyang Bay, 34 +/- 4% for the inner shelf, and 5.5 +/- 1% for the outer shelf. The molecular composition of the carbohydrate in the surface sediments also suggested that the inner estuary was rich in terrestrially derived carbohydrates but that their contribution decreased offshore. A relatively high abundance of deoxyhexoses in the estuary and shelf indicated a considerable bacterial source of these carbohydrates, implying that sediment organic matter had undergone extensive degradation and/or transformation during transport. Sediment budget based on calculated regional accumulation rates showed that only similar to 50% of the influxes of terrestrial organic carbon were accumulated in the estuary. This relatively low accumulation efficiency of terrestrial organic matter as compared to the total suspended solids (accumulation efficiency similar to 73%) suggested significant degradation of the terrestrial organic carbon within the estuarine system after its discharge from the river. This study demonstrated that the combination of the bulk organic matter properties together with the isotopic composition and molecular-level carbohydrate compositions can be an efficient way to track down the source and fate of organic matter in highly dynamic estuarine and coastal systems. The predominance of terrestrially originated organic matter in the sediment and its generally low accumulation efficiency within the estuary is not surprising, and yet it may have important implications in light of the heavy anthropogenic discharges into the Pearl River Estuary during the past thirty years.Natural Science Foundation of China [49825111, 40176025, 90211020

Methodology and applications of city level CO2 emission accounts in China

China is the world's largest energy consumer and CO2 emitter. Cities contribute 85% of the total CO2 emissions in China and thus are considered as the key areas for implementing policies designed for climate change adaption and CO2 emission mitigation. However, the emission inventory construction of Chinese cities has not been well researched, mainly owing to the lack of systematic statistics and poor data quality. Focusing on this research gap, we developed a set of methods for constructing CO2 emissions inventories for Chinese cities based on energy balance table. The newly constructed emission inventory is compiled in terms of the definition provided by the IPCC territorial emission accounting approach and covers 47 socioeconomic sectors, 17 fossil fuels and 9 primary industry products, which is corresponding with the national and provincial inventory. In the study, we applied the methods to compile CO2 emissions inventories for 24 common Chinese cities and examined uncertainties of the inventories. Understanding the emissions sources in Chinese cities is the basis for many climate policy and goal research in the future

Preliminary Step Towards Wire-Driven Parallel Suspension Systems for Static and Dynamic Derivatives of the Aircraft in Low-Speed Wind Tunnels

The wind tunnel test is one important way to obtain the aerodynamic derivatives of aircrafts. These derivatives are necessary when the guidance and control systems of the aircraft are designed and when the dynamic quality of the aircraft is analyzed as well. The results of experiments of the static derivatives and dynamic derivatives of the aircraft in low-speed wind tunnels have revealed that there are some unavoidable drawbacks such as the interference of the streamline flow brought about by the strut in the traditional strut suspension system. A cable-mounted system is very suitable for experiments of the static derivatives of an aircraft, but it cannot be used in the experiments of dynamic derivatives. In order to use the same wire-driven parallel suspension system to realize the static and dynamic derivates experiments in low-speed wind tunnels, a survey of the research work addressed within the Wire-Driven Parallel Suspension Systems (WDPSS-8) project is presented in this paper. The results show that WDPSS-8 can be successfully used in experiments of static derivatives, and that it has potentiality to be used in experiments of dynamic derivatives. In the issues in the theoretical aspect the issues have been handled. However, much work should be done in the experimental aspects. The research outcomes of WDPSS-8 will help the Chinese set up Chinese brands in the field of wind tunnel tests of aircrafts

A Bingham-plastic model for fluid mud transport under waves and currents

Simplified equations of fluid mud motion, which is described as Bingham-Plastic model under waves and currents, are presented by order analysis. The simplified equations are non-linear ordinary differential equations which are solved by hybrid numerical-analytical technique. As the computational cost is very low, the effects of wave current parameters and fluid mud properties on the transportation velocity of the fluid mud are studied systematically. It is found that the fluid mud can move toward one direction even if the shear stress acting on the fluid mud bed is much smaller than the fluid mud yield stress under the condition of wave and current coexistence. Experiments of the fluid mud motion under current with fluctuation water surface are carried out. The fluid mud transportation velocity predicted by the presented mathematical model can roughly match that measured in experiments

Supporting information for: Interaction between oxygen consumption and carbon dioxide emission in a subtropical hypoxic reservoir, southeastern China

Measured data for the study on Interaction between oxygen consumption and carbon dioxide emission in a subtropical hypoxic reservoir, southeastern China</b

Leucine Aminopeptidase from Red Sea Bream (Pagrus major) Skeletal Muscle: Purification, Characterization, Cellular Location, and Tissue Distribution

A leucine aminopeptidase was purified for the first time from marine fish red sea bream (Pagrus major skeletal muscle to homogeneity with 4850-fold and a yield of 7.4%. The purification procedure consisted of ammonium sulfate fractionation and chromatographies including DEAE-Sephacel, Sephacryl S-200, hydroxyapatite, and phenyl-Sepharose. The enzyme was approximately 96 kDa as estimated by SIDS-PAGE and gel filtration and preferentially hydrolyzed substrate Leu-MCA. The enzymatic activity was optimal at 45 degrees C and pH 7.5. The K-m and k(cat) values of the enzyme for Leu-MCA were 1,55 mu M and 26.4 S-1 at 37 degrees C, respectively. Activation energy (E-a) of the enzyme was 59.6 kJ M-1. The enzyme was specifically inhibited by metal-chelating agents, and Zn2+ and (or) Mn2+ seemed to be its metal cofactor(s). In addition, bestatin strongly inhibited its activity, and K-i was 1.44 mu M. Using a highly specific polyclonal antibody, the location of enzyme was demonstrated intracellularly and distributed in different tissues.National Natural Scientific Foundation of China [30571450]; Natural Scientific Foundation of Fujian Province [2006J0368]; Foundation for Innovative Research Team of Jimei University [2006A002

A Wire-Driven Parallel Suspension System with 8 Wires (WDPSS-8) for Low-Speed Wind Tunnels

Based on researching into WDPSS-8, after analysing and comparing 3 support systems in wind tunnel including the strut suspension system, cable mounted system and wire-driven parallel suspension system, the following conclusions can be acquired. 1) Till now the strut support systems and rotary balances can be used in measuring the dynamic derivatives of the aircraft in low-speed wind tunnels successfully, wire-driven parallel suspension system has a great potentiality, but it is still under investigation. 2) The cable mounted system is one of suitable method for measuring the static derivatives of the aircraft in LSWT. Though it allows a large supporting stiffness, small interference of the streamline flow and a high measuring precision for large attack angle, it can not be used in measuring the dynamic derivatives. 3) Wire-driven parallel suspension system has opened a new horizon for measuring the static and dynamic derivatives of the aircraft in LSWT. Using the same system based on position control and force control in robotics, it allows to realize the free flight of the aircraft model and to obtain the static and dynamic derivatives. However, the results given in this Chapter can only be considered as a preliminary step in establishing feasibility，although the wire-driven parallel suspension system is a very interesting design, and it may be sufficiently developed into a routine practical system