Studies on the Tolerating Mechanism for Sulfide in Urechis Unicinctus (Echiura:Urechidae)-cytological observation on Urechis Unicinctus in Different Hydrogen Sulfide Environment

This study on the cytological changes of the body wall ,aspiratory intestine and crissal bursa in Urechis unicincuts by light microscope(LM) and transmission electron microscope(TEM) showed that the difference between the body wall and the natural environment rich in H2S was not obvious,that the wall color of the aspiratory intestine in H2S rich environment changed from normal semitransparency to dark brown.that its epithelia were disassembled and the electron density of its cytoplasm matrix was lower;and that in H2S rich environment many basoplhilic granules occurred in the epithelia of the crissal bursa.Granules with single membrane and myelinefingure were found with TEM.     

A Kinetic Spectrophotometric Method for the Determination of Iron (Ⅲ) in Water Samples

A new kinetic spectrophotometric method has been developed for the determination of iron (Ⅲ). The method is based on the catalytic effect of iron (Ⅲ) on the oxidation of weak acid brilliant blue dye (RAWL) by KIO4 in acid medium. The advantages of the proposed method are that it is sensitive, accurate, rapid, inexpensive, can be operated under room temperature and has a large determination concentration range compared to other techniques. The obtained optimum conditions are: pH 3.15, RAWL (200 mgL-1) 5.00mL, Potassium periodate solution (0.01 molL-1) 0.30mL, phenanthroline (0.02molL-1) 1.00mL, reaction temperature 25℃ and reaction time 7 miu. With this method iron could quantitively be determined in the range 0.00-0.02 mgL-1, the detection limit being 4.10×10-10mL-1. The relative standard deviations (RSD) in five replicate determinations for 3 μgL-1 and 5μgL-1 iron (Ⅲ) are 3.1% and 1.9%, respectively. The method has been applied to the determination of iron (Ⅲ) in tap water samples and seawater samples (from the South China Sea), the recovery rates being 98.0% and 100.5%, respectively.     

Tourism management in national parks: ?umava and Bayerischer Wald(Bavarian Forest) in the Czech-German borderland

Along the Czech-German border there are four national parks, two Czech and two German, arranged in cross-border ‘pairs'. This article focuses on the southern ‘pair' formed by the parks of ?umava and Bayerischer Wald(Bavarian Forest). The aim is to evaluate and compare tourism organization in their areas, taking into account selected aspects of management: the network of hiking trails with its related infrastructure, transport accessibility, a typology of tourist centers, as well as directions and destinations of tourist movements. Based on the results, it can be concluded that the availability of geographical space for tourists is much greater in the German than in the Czech national park, and the tourism infrastructure is clearly more extensive there, including the network of tourist trails. This is mainly due to the longer and fairly uninterrupted development of tourism in this area. ?umava National Park can be identified as a model in terms of how to adjust the directions of tourist movements and the layout of the tourist trail network to the needs of natural environment. On the basis of observations in both national parks, it is possible to indicate various solutions that, after appropriate adaptation, may bring benefits to other protected areas.     

Accessibility for High Asia:Comparative Perspective on Northern Pakistan''''s Traffic Infrastructure and Linkages with Its Neighbours in the Hindukush- Karakoram-Himalaya

Introduction The birth of Pakistan in particular and theindependence and creation of some other Asiannation states in general coincide with an internationaleffort to overcome colonialization and tostrengthen mutual exchanges of goods andknowledge. The age of planned developmentcommenced with the unanimously recommendedstrategy of modernization. The concept ofmodernity was virtually synonymous witheconomic growth. To sustain and accelerateeconomic growth, an adequate physicalinfrastructure was…     

A Fast and Indriect Fluorescent Antibody Assay for the Vibro in Large Yeelow Croaker Pseudosciaena Crocea (Richardson)

A fast and indirect fluorescnet antibody assay for the Vibrio alginolyticus and V.Parahaemolyticus infecting the large yellow croaker has been developed.The specific antisera for the two strains of vibrio were prepared with New Zealand rabbit and the antiserum and cross-reactive efficacy was tested by coagulation in tube.It showed that the goat anti-rabbit IgG had been labeled by fuorescence isothiocyanate(FITC).The results showed that positive reactions were 100% for the large yellow croaker Pseudosciaena crocea with typical symptom of vibrio infection,while the positive reaction to the pathogen in healthy yellow croakers reached 40%,but seemed negative for aquaculter water.The results demonstrated that this fast and indirect fluorescent antibody assay can be used not only to test the vibrio pathogen in diseased yellow croaker but also in infected animals with no symptom.     

A Fast and Indirect Fluorescent Antibody Assay for the Vibrio in Large Yellow Croaker Pseudosciaena crocea (Richardson)

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A new method for the estimation of fine-sediment resuspension ratios in estuaries-taking the turbidity maximum zone of the Changjiang(Yangtze) estuary as an example

Based on the principle of conservative matter removal in estuary,a new method is proposed for estimating the ratio of sediment resuspension in estuaries with fine suspended sediments in the turbidity maximum zone(TMZ) of the Changjiang(Yangtze) estuary during 2005.Results show that there was a range of 18.7%±27.9% to 73.9%±22.5% per annum of total suspended particulate matter(SPM),with an average of 49.2%.Nearly half of the particulate matter in the TMZ originates from sediment resuspension.This indicates that sediment resuspension is one of the major mechanisms involved in formation of the TMZ.Compared with traditional method for calculating these ratios in the estuary,this new method evaluates the dynamic variation of SPM content carried by river runoff from the river mouth to the ocean.The new method produced more reliable results than the traditional one and could produce a better estimation of resuspension flux for particulate matter in estuaries.     

China's Global Shipping Connectivity: Internal and External Dynamics in the Contemporary Era(1890–2016)

China's global shipping connectivity had been somewhat overlooked as the bulk of related studies predominantly focused on the throughput volume of its own port cities. This article tackles such lacunae by providing a relational perspective based on the extraction of vessel movement archives from the Lloyd's List corpus. Two complementary analyses are proposed: long-term dynamics with all ships included(1890–2008) and medium-term dynamics focusing on container flows(1978–2016). Each analysis examines China's maritime connectivity in various ways and on different spatial scales, from the global to the local, in terms of concentration, vulnerability, and expansion. The main results underline the influence of technological, economic, and political factors on the changing distribution of connectivity internally and externally. In particular, China has managed to reduce its dependence upon external transit hubs, to increase the internal connectivity of its own port system, and to strengthen its dominance towards an increasing number of foreign nodes and trade partners through the maritime network.     

Gradient effect on farmers’ income in the mountain areas and its implication for poverty alleviation strategies: Empirical analysis from the upper reach of Minjiang River, China

Using four types of settlements in the upper reach of Minjiang River as case,we establish structural models in farmers’ income of different settlement patterns based on rural household panel data to reveal the gradient effect on farmers’ income and determinants.The results indicate that:(1) except the resettlement area,the incomes for farmers living in river valley,semi-mountain,and high-mountain settlements present a decreasing trend with the elevation increasing;on the contrary,their nonfarm earnings show an increasing trend with the elevation decreasing;(2) from the effect on farmers’ income,there is a common feature that the nonfarm earnings and farming incomes have significant positive effects,and family size and productive expenditure have significant negative effects.One exception to this is the productive expenditure,which becomes insignificant in the model of resettlement area;(3) from the way of increasing farmers’ income and alleviating poverty,there are great differences for four types of settlements in mountain areas,however,the improvement of agricultural product sales,agricultural production subsidies,the expansion for nonfarm employment,and the control of the family’s size are the most effective approaches for poverty alleviation.     

Study of Panjin Wetlands Along Bohai Coast: (Ⅰ) the Information System of Wetlands Based on 3S Technique

Based on previous studies on Panjin wetlands along the coast of the Bohai Sea,this paper adopts RS,GIS and GPS tech-niques and establishes the information system for Panjin wetlands.The system involves many functions,such as identification andclassification of wetlands,calculation of the area of wetlands and storage of the information of the wetland management.Moreover,our study indicates that remote sensing technique is a useful tool for great macrography,speediness and accuracy to carry out theextraction,analysis,management and handling of information together with geography information system,which has prospectiveapplications in similar kinds of research.     

Study on the distribution,abundance and growth condition of Antarctic Krill(Euphausia superba)in the Prydz Bay region,Antarctica during the Austral summer of 1999/2000

Antarctic krill (Euphausia superba) were collected from the Prydz Bay region during the austral summer of 1999/2000. The sample - collection was made at 15 sites in 3 longitudinal transects. Although krill were encountered at 14 sites, the abundance was comparatively low in general. The main component of the krill population was of post -larval stages. The mean numerical and weight density of krill integrated for all sampling stations in the survey area were 16. 17 ind. 1000 m -3and 12.02 g 1000 m -3 , respectively. In the survey area, stations with larger krill density are mainly located in the slope zone, except that the largest sample was collected in the open sea zone. No krill occurred in the only station of the shelf zone during our investigation. Krill collected from the slope zone were under better growth condition than those from the open sea zone, but when the survey area is considered as a whole, the growth condition is normal. The results of the comprehensive analysis of the environmental fa     

Analyses of Trawling Track and Fishing Activity Based on the Data of Vessel Monitoring System (VMS)：A Case Study of the Single Otter Trawl Vessels in the Zhoushan Fishing Ground

The original purpose of Vessel Monitoring System(VMS) is for enforcement and control of vessel sailing. With the application of VMS in fishing vessels, more and more population dynamic studies have used VMS data to improve the accuracy of fisheries stock assessment. In this paper, we simulated the trawl trajectory under different time intervals using the cubic Hermite spline(c Hs) interpolation method based on the VMS data of 8 single otter trawl vessels(totally 36000 data items) fishing in Zhoushan fishing ground from September 2012 to December 2012, and selected the appropriate time interval. We then determined vessels’ activities(fishing or non-fishing) by comparing VMS speed data with the corresponding speeds from logbooks. The results showed that the error of simulated trajectory greatly increased with the increase of time intervals of VMS data when they were longer than 30 minutes. Comparing the speeds from VMS with those from the corresponding logbooks, we found that the vessels’ speeds were between 2.5 kn and 5.0 kn in fishing. The c Hs interpolation method is a new choice for improving the accuracy of estimation of sailing trajectory, and the VMS can be used to determine the vessels’ activities with the analysis of their trajectories and speeds. Therefore, when the fishery information is limited, VMS can be one of the important data sources for fisheries stock assessment, and more attention should be paid to its construction and application to fisheries stock assessment and management.     

Altitudinal trends in δ~(13)C value,stomatal density and nitrogen content of Pinus tabuliformis needles on the southern slope of the middle Qinling Mountains,China

In this study,a coniferous tree species(Pinus tabuliformis Carr.) was investigated at a moderate-altitude mountainous terrain on the southern slope of the middle Qinling Mountains(QLM) to detect the trends in carbon isotope ratio( δ~(13)C),leaf nitrogen content(LNC) and stomatal density(SD) with altitude variation in northsubtropical humid mountain climate zone of China.The results showed that LNC and SD both significantly increased linearly along the altitudinal gradient ranging from 1000 to 2200 m,whereas leafδ~(13)C exhibited a significantly negative correlation with the altitude.Such a correlation pattern differs obviously from that obtained in offshore low-altitude humid environment or inland high-altitude semi-arid environment,suggesting that the pattern of increasing δ~(13)C with the altitude cannot be generalized.The negative correlation between δ ~(13)C and altitude might be attributed mainly to the strengthening of carbon isotope fractionation in plants caused by increasing precipitation with altitude.Furthermore,there was a remarkable negative correlation between leaf δ ~(13)C and LNC.One possible reason was that increasing precipitation that operates to increase isotopic discrimination with altitude overtook the LNC in determining the sign of leaf δ ~(13)C.The significant negative correlation between leaf δ ~(13)C and SD over altitudes was also found in the present study,indicating that increases in SD with altitude would reduce,rather than enhance plant δ~(13)C values.