VARIATION IN FLOW AND SEDIMENT OF DASHA RIVER AND INFLUENCE OF HUMAN ACTIVITIES ON IT IN SOUTHWEST REGION OF ANHUI PROVINCE

Soil and water loss is now a major environmental problem in many areas of China, especially in the area of the Dabie Mountain, Anhui Province, which results in environmental degradation and does harm to the people＇s life and production there. Based on the observational records from the Dasha River, the authors analyze the character of the variation in flow and sediment in different flood and dry seasons from 1970 to 2000. The result shows that human activities had significantly reduced the sediment discharge and sediment module, and increased the runoff in low-water seasons since the 1980s. The average contribution rate ofhnman activities to decreasing sediment was 65.67%, and at the same period the contribution rate of runoff and rainfall was about 34.33%. Therefore, it is necessary to take the biological and engineering measures to solve the problem of soil and water loss in the Dasha River watershed.

Time derivative of earthquake acceleration

Unlike acceleration, velocity, and displacement, the time derivative ofacceleration (TDoA) of ground motion has not been extensively studied. In this paper, the basiccharacteristics of TDoA are evaluated based on records from the 1999 Chi-Chi, earthquake (Mw 7.6)and one of its aftershocks (Mw 6.2). It is found that the maximum TDoA at a free-field station wasover 31,200 cm/s3 (31.8 g/s); and the duration of 'strong' TDoA, between the first and the last timepoints exceeding 2,000 cm/s3 (2 g/s), was almost one minute near the epicenter area. Since groundTDoA sensors are not commonly available, the time series are calculated by direct numericaldifferentiation of acceleration time series. Relative error analysis shows that the error isnon-transitive and total error is within 4%. The density function of TDoA amplitude, frequencycontent and spatial distribution of peak ground jerk (PGJ) are evaluated. The study also includesexamination of some TDoA responses from a seven-story building and comparison of ground TDoA withthe limit TDoA used in the transportation industry for ride comfort. Some potential impacts of TDoAon humans have also been reviewed.

Expression and Antigen Activity Determination of Human Thyroid Peroxidase in Silkworm and Yeast

In this study,we report the expression of human thyroid peroxidase（TPO） in silkworm larvae and Pichia pastoris GS115. Recombinant TPO is sequentially purified from the hemolymph of infected silkworm larvae and yeast using a Ni-NTA resin kit. The concentration of yield of recombinant TPO is 4.87 mg per thousand larvae and 40.83 mg per liter yeast culture. However,the recombinant TPO produced in silkworm show similar binding ability with the specific anti-TPO serum to standard human TPO purified from insect cells. The lower antigen activity indicates the TPO expressed in yeast is not suitable to be used as the coating antigen in enzyme linked immunosorbent assay（ELISA）. The cost of TPO expressed in B. mori is about 1/4 that of in insect cells,and the cost of TPO purified from silkworm for ELISA is only 1/8 that of TPO produced from Sf9 cells. It indicates the Bm NPV-silkworm expression system is a cost-effectiv e platform for producing TPO with high antigen activity.