An improved terminal deoxynucleotidyl transferase- mediated dUTP-biotin nick end labeling method for the quantification of DNA damage in tissues and cultured cells was developed. Many reports have revealed that histoc...An improved terminal deoxynucleotidyl transferase- mediated dUTP-biotin nick end labeling method for the quantification of DNA damage in tissues and cultured cells was developed. Many reports have revealed that histochemistry of DNA damage can be visualized using immunohistochemistry for the terminal deoxynucleotidyl transferase reaction in tissue sections. However, few reports have described quantification of DNA damage in tissues or cells. In this study, to estimate the degree of DNA damage, the confirmed method for histochemistry using biotinylated dUTP and deoxynucleotidyl transferase was applied to label the cleaved DNA ends caused by DNA damage in tissues or cells. After end-labeling, avidin-conjugated peroxidase was reacted. A significant correlation was observed between numbers of cleaved DNA ends and peroxidase activity after the reaction. The obtained signals for presented method showed higher than those for ordinary method, and correlate with degree of DNA damage caused by serum deprivation and chemical dose. In addition, DNA damage caused by apoptosis in cells treated with 6-hydroxydopamine or Cu and in the tissues of rats administered a diet containing no Zn could be evaluated quantitatively using the present method.展开更多
Expecting that agricultural yield is highly dependent on climatic conditions, particularly water availability and suitable temperature, an agroclimatic study was carried out on rice crops during three different season...Expecting that agricultural yield is highly dependent on climatic conditions, particularly water availability and suitable temperature, an agroclimatic study was carried out on rice crops during three different seasons in four regions of Bangladesh. Data on climate （surface air temperature and precipitation） and seasonal rice production were examined for the period 1986-2006 from 18 rice growth observatories. The relationship between climate and rice production was statistically analyzed by removing long-term trends so that the effects of improved irrigation, which results in a general increase in crop production, may be removed. The analysis involved both single and multiple regressions. The results suggested that, during monsoon and summer, higher temperatures had negative effects on rice production, especially in the northwestern （NW） region. In winter, positive effects were observed throughout Bangladesh. Since the annual mean temperature was positively correlated with those in the three seasons individually, the annual temperature had negative effects on the annual rice production only in the NW region, while it had positive effects in the central and southern regions. With the exception of the NW region, it was basically dry, excessive rainfall both in summer and monsoon yielded floods and reduced rice yield. In winter, more rainfall showed positive effects on crop production only in the central region, which was least irrigated. These findings suggested that accelerated atmospheric warming would result in serious damage to crops during summer and monsoon. Reliable prediction of future crop production will rely on the temperature and rainfall trends in individual seasons.展开更多
文摘An improved terminal deoxynucleotidyl transferase- mediated dUTP-biotin nick end labeling method for the quantification of DNA damage in tissues and cultured cells was developed. Many reports have revealed that histochemistry of DNA damage can be visualized using immunohistochemistry for the terminal deoxynucleotidyl transferase reaction in tissue sections. However, few reports have described quantification of DNA damage in tissues or cells. In this study, to estimate the degree of DNA damage, the confirmed method for histochemistry using biotinylated dUTP and deoxynucleotidyl transferase was applied to label the cleaved DNA ends caused by DNA damage in tissues or cells. After end-labeling, avidin-conjugated peroxidase was reacted. A significant correlation was observed between numbers of cleaved DNA ends and peroxidase activity after the reaction. The obtained signals for presented method showed higher than those for ordinary method, and correlate with degree of DNA damage caused by serum deprivation and chemical dose. In addition, DNA damage caused by apoptosis in cells treated with 6-hydroxydopamine or Cu and in the tissues of rats administered a diet containing no Zn could be evaluated quantitatively using the present method.
文摘Expecting that agricultural yield is highly dependent on climatic conditions, particularly water availability and suitable temperature, an agroclimatic study was carried out on rice crops during three different seasons in four regions of Bangladesh. Data on climate （surface air temperature and precipitation） and seasonal rice production were examined for the period 1986-2006 from 18 rice growth observatories. The relationship between climate and rice production was statistically analyzed by removing long-term trends so that the effects of improved irrigation, which results in a general increase in crop production, may be removed. The analysis involved both single and multiple regressions. The results suggested that, during monsoon and summer, higher temperatures had negative effects on rice production, especially in the northwestern （NW） region. In winter, positive effects were observed throughout Bangladesh. Since the annual mean temperature was positively correlated with those in the three seasons individually, the annual temperature had negative effects on the annual rice production only in the NW region, while it had positive effects in the central and southern regions. With the exception of the NW region, it was basically dry, excessive rainfall both in summer and monsoon yielded floods and reduced rice yield. In winter, more rainfall showed positive effects on crop production only in the central region, which was least irrigated. These findings suggested that accelerated atmospheric warming would result in serious damage to crops during summer and monsoon. Reliable prediction of future crop production will rely on the temperature and rainfall trends in individual seasons.
