The genus
The accurate assessment of actual tree stem respiration and its relation with temperature plays a considerable role in investigating the forest carbon cycle. An increasing number of research reports have indicated that tree stem respiration determined with the commonly-applied chamber gas exchange measuring system does not follow expectations regarding temperature relationships. This method is based on the nowadays widely-accepted theory that the respired CO2 in a tree stem would all diffuse outward into the atmosphere. However, it neglects partial CO2 that is dissolved in the xylem sap and is carried away by the transpirational stream. Scientists have started to realize that the respired CO2 measured with the chamber gas exchange method is only a portion of the total stem respiration (CO2 efflux), while the other portion, which is sometimes very substantial in quantity (thought to occupy maybe 15%-75% of the total stem respiration), is transported to the upper part of the stem and to the canopy by sap flow. This suggests that the CO2 produced by respiration is re-allocated within the stem. Accordingly, the change in CO2 efflux could be reflected in the rates of sap flow in addition to its dependence on temperature. Proper methods and instruments are required to quantify the internal and external CO2 fluxes in the trunk and their interaction with related environmental factors.
The majority of single nucleotide polymorphisms (SNPs) found in the coding region (cSNPs) are single base substitutions that may or may not lead to amino acid substitutions, most of which are related to diseases. Some cSNPs may prove useful for their potential links to functional cSNPs via linkage disequilibrium mapping. We have selected 48 cSNPs located in the coding regions of 25 genes to construct the cSNP chip. These genes are harbored in the high frequency loss regions of the chromosome 1p and 8p and related with apoptosis, cell cycles, signal transduction, oncogene, tumor suppressor genes and so on. All of the cSNPs can lead to amino acid substitutions except TP73 (rs1801174). The PCR products amplified from 31 hepatocellular carcinoma (HCC) specimens were labeled with Dig-dUTP and then hybridized with the cSNP chips. The results showed that there was no hybridization signal when there was more than one site of mutation in the amplification sequence, indicating that the cSNP chip had a high sensitivity. The statistic data of the SNP (MT, homozygous and HT, heterozygous) in the HCC patients with different phenotypes (HBV +/-,differentiation stage, family history positive or negative, tumor size) indicated that the number of MT was distinctly different between patients with positive HBV and negative HBV. The MT and HT numbers of all the 48 cSNPs were significantly different between low differentiation and high differentiation HCC patients. The numbers of MT and HT were not different between positived and negative family history groups and between tumor size > 3 cm and ≤ 3 cm groups. The study results provided useful information for understanding the molecular mechanisms of HCC development.
The present investigation on fungal diversity shows that there were rich fungal resources of up to 196 species, belonging to 41 families and 90 genera, in the Qinling Mountainous Range of central China. The dominant families were