Area Of Southeast China Research Articles

Critical loads of acid deposition on soil in China.

Critical loads of acid deposition havebeen mapped for Chinese soils using a modifiedsemi-quantitative method, which is based on theminerals controlling weathering and soil development,and corrected by introducing an Arrhenius relationshipto describe the effect of temperature and a weightedaveraging approach to evaluate the effect of soiltexture, land use and precipitation. As a consequenceof these modifications, the method has been quantifiedand can be more widely used. Results from this studyshow that the lowest critical loads of acid depositionin China, i.e., those areas most sensitive to aciddeposition, occur in the Podzolic soils in theNortheast, followed by Latosol, Dark brown forest soiland Black soil areas. The Ferralsol areas in SouthChina are intermediate, tolerating about 0.8–1.6 g m-2 yr-1 sulfur deposition. The highestcritical loads of acid deposition are mainly locatedin the Alpine soil areas on the Plateau of Tibet andareas of Xerosol and Podocal soil in Northwest China.The reason for lower critical loads in the Northeastrelative to South China can be attributed to thedifference of temperature, soil moisture and soiltexture. Comparison of critical loads with the sulfurdeposition in 1995 identifies almost one fourth of theland area in southeast China to be subject to risk of acidification.

Precipitation patterns in flood season over China associated with the El Niño/Southern Osciliation

The precipitation patterns in flood season over China associated with the El Nino/Southern Oscillation (ENSO) are investigated, especially in the eastern China, using the rather long period rainfall data in this century. The results show that there were remarkable differences between the precipitation patterns in flood seasons of ENSO warm phase (El Nino year) and cold phase (La Nina year), as well as between the patterns in El Nino years and their following years. The most parts of China received below normal rainfall in flood season of the onset years of El Nino events, but the coastal area of Southeast China received above normal amounts. Comparatively, the most parts of China received above normal rainfall in flood season of the following years of El Nino events, but the eastern part of the reaches among the Huanghe (Yellow) River, the Huaihe River and the Haihe River, and the Northeast China received less. During ENSO cold phase, the reaches of the Changjiang (Yangtze) River and the North China received more amounts than normal rainfall in flood season of the onset years of La Nina events, and the other regions of China received less. In the following years of La Nina events, the coastal area of the Southeast China, the most part of the Northeast China and the regions between the Huanghe River and the Huaihe River received more precipitation during flood seasons, but the other parts received below normal precipitation.

Glacial and Periglacial Paleoenvironments in the Japanese Islands.

The paper reviews three main topics of recent studies of Quaternary glacial and periglacial environments in Japan: chronology of glaciations, showline elevation, and permafrost distribution in the Last Glacial age. Two glaciations have been recognized in the Japanese high mountains during the Last Glacial age. The younger one corresponds to the isotope stage 2, and the older one to the stage 4. The alpine glacier attained its maximum extension in stage 4, because of more favorable snowfall conditions in this stage. The oldest glaciations which have been morphologically defined correspond to the isotope stage 5d or 6. The distribution of snowline elevation during stage 4 in eastern Asia shows (1) an abrupt increase of snowline elevation at the eastern margin of Qinghai-Xizang Plateau; (2) no possibility of Quaternary glaciation in the Mt. Lushan area in Southeast China; (3) existence of snowline trough which streches from Formosa towards the mountains of the Japan Sea side of Japan, and (4) the high snowline elevation in Central and Northern Hokkaido, suggesting the winter dryness. The research of present alpine permafrost environment on Mts. Daisetsuzan, central Hokkaido, and the fossil periglacial phenomena in the lowland of Hokkaido have revealed that the island was mostly in the discontinuous permafrost zone in the Last Glacial age.

Epstein-Barr virus DNA m nasopharyngeal biopsies

The Epstein-Barr virus (EBV) has been closely associated with the undifferentiated form of nasopharyngeal carcinoma (NPC), which is particularly common in the high risk area in southeast China. We have examined 37 nasopharyngeal biopsies from patients within this high risk area, including 31 cases of undifferentiated NPC and 6 cases of patients with nasopharyngitis, for the presence of EBV DNA. We found that 26 of 31 biopsies from NPC patients were EBV DNA positive; 3 of the 6 biopsies from patients diagnosed with nasopharyngitis were also EBV DNA positive. Southern blot analysis of the DNAs obtained from the EBV genome positive biopsies, digested with EcoRI, showed that all preparations from the NPC tumors had only one band corresponding to the EcoRI A fragment when a BamHI W fragment was used as a probe. However, one tumor had an additional band with a molecular weight larger than EcoRI A. The presence of this novel band could indicate the integration of viral DNA into host cellular DNA. DNA from the same biopsies were restricted with BamHI and PstI restriction enzymes. The data obtained from these experiments suggest that the EBV genomes in both the NPC tumor biopsies and biopsies from nasopharyngitis patients obtained from an endemic area in South China may be similar to each other and to the B95-8 EBV isolate with respect to the BamHI Y region of the EBV genome. The data also demonstrate that infection of normal nasopharyngeal epithelial cells with EBV takes place in patients with nasopharyngitis.

A Golgi study on the histogenesis of the spinal motoneurons in the domestic hen (gallus domesticus)

In order to determine and trace geochemical anomalies in soils, a tungsten (W) metallogene was constructed according to the idea of the gold (Au) metallogene previously developed. Based on the outcomes obtained for the Tieshanlong tungsten deposit area in southeast China from both three weathered profiles and a subset of data extracted from a regional geochemical survey database, a value of 40% of similarity between a W metallogene and an ideal ore was set as a criterion to individuate samples with potential W mineralization. Based on their W or Au metallogenes, a value of 70% of similarity was also chosen as the threshold criterion to locate samples with similar genes relative to a parent rocks or its weathered products. Based on the regional geochemical survey data available for the Tieshanlong tungsten deposit area, single elemental anomalies were determined and classified by means of the “seven levels' classification” method. Integrated anomalies were also determined and classified by using similarities (relative to their ideal ore) on W and Au metallogenes. Results indicate that the determined anomaly regions are well spatially consistent with the known deposits and that the metallogenes can be used to trace mineralized soil samples. Furthermore, the location of mineralized samples sourced by (altered) magmatic rock could be well pinpointed on geochemical genes, as well.It was also observed that a value of 80% similarity for a lithogene (a geochemical gene based on a sequence of eleven immobile elements) which, similarly to metallogene, allow to compares samples to a specific parent rock and its weathered products, may be too stringent in the case of sedimentary rocks (even if metamorphosed) due to their relevant geochemical heterogeneity.