GIS-based Analysis for Hotspot Identification of Tradeoff Between Ecosystem Services： A Case Study in Yanhe Basin, China

Although the quantification and valuation of ecosystem services have been studied for a long time, few studies have specifi- cally focused on the quantification of tradeoffs between ecosystem services and tradeoff hotspots, Based on previous studies of ecosys- tem service assessment, we proposed a feasible method to analyze the tradeoffs between ecosystem services, including determination of their relationship, quantification of tradeoffs, and identification of tradeoff hotspots. Potential influencing factors were then further ana- lyzed. The Yanhe Basin in the Loess Plateau was selected as an example to demonstrate the application process. Firstly, the amounts of net primary production （NPP） and water yield （WY） in 2000 and 2008 were estimated by using biophysical models, Secondly, correla- tion analysis was used to indicate the tradeoffs between NPP and WY. Thirdly, tradeoff index （TINpp/wy） was established to quantify the extent of tradeoffs between NPP and WY, and the average value of TINpp/wy is 24.4 g/（mm·m2） for the Yanhe Basin between 2000 and 2008. Finally, the tradeoff hotspots were identified. The results indicated that the area of lowest tradeoff index concentrated in the mid- dle part of the Yanhe Basin and marginal areas of the southern basin. Map overlapping was used for preliminary analysis to seek poten- tial influencing factors, and the results showed that shrub was the best suited for growing in the Yanhe Basin, but also was a potential irtfluencing factor for formulatiort of the tradeoff hotspots. The concept of tradeoff index could also be used to quantify the degree of synergy between different ecosystem services. The method to identify the tradeoff hotspots could help us to narrow the scope of study area for further research on the relationship among ecosystem services and concentrate on the potential factors for formation of tradeoff between ecosystem services, enhance the capacity to maintain the sustainability of ecosystem.

Integrating Factors and Conservation Laws of Generalized Birkhoff System Dynamics in Event Space

In this paper, the conservation laws of generalized Birkhoff system in event space are studied by using the method of integrating factors. Firstly, the generalized Pfaff-Birkhoff principle and the generalized Birkhoff equations are established, and the definition of the integrating factors for the system is given. Secondly, based on the concept of integrating factors, the conservation theorems and their inverse for the generalized Birkhoff system in the event space are presented in detail, and the relation between the conservation laws and the integrating factors of the system is obtained and the generalized Killing equations for the determination of the integrating factors are given. Finally, an example is given to illustrate the application of the results.

GENE EXPRESSION OF GROWTH FACTOR RECEPTORS AND NEURONAL MARKERS IN NEURO BLASTOMA CELL LINES

Gene expression of nerve growth factor receptor (NGFR), epidermal growth factor receptor (EGFR), chromogranin A (CGA) and neuropetide Y (NPY)in 4 aeuroblsstoma cell lines without N-myc amplification was studied by wins Northern blot technique, N type cells expressed more NGFR mRNA than S type cells and have only little or no EGFR expression. S type cells had stronger expression of EGFR mRNA than that of N type cells accompanying with only less or even no NGFR expression. The results Indicated that difference of gene expression of theae growth factor receptors might be due to the various of tumor cell differetiation. Celli differentiating toward neurons gave more NGFR expression and cells prepared to be differentiating toward other direction might give more EGFR gene expression.Various gene expression of CGA and NPY In neuroblsstoma cell lines might be due to the presence of different stages of tumor cell differentiation and NGF only Induced differentiation of those neuroblastoma cells ready to be differentiation to neurons afterwards.