张量不变式方法在物理张量计算中的应用——(Ⅰ)原理

对张量不变式方法进行了改造和推广,系统地阐明了它的基本原理和使用步骤。提出了伴随基定理和独立基个数定理,并在此基础上得到了所有晶体点群的一到三秩同变正交基,使得张量不变式方法能够简便、准确地用于所有常用的物理张量的计算。

Isozyme Analysis on the Populations of Ruditapes philippinarum

Horizontal starch gel electrophoresis was used to investigate the genetic structure of six populations of Ruditapes philippinarum in the coast of China. Seven enzymes revealed eleven putative loci, and seven of them were polymorphic, PGM^＊, MDH-1^ ＊, MDH-3^＊, LAP-1^＊, LAP-2^＊, MPI-1^＊ and MPI-2^＊. The proportions of polymorphic loci of R. philippinarum populations varied from 0.454 5 to 0.636 4. The values of observed and expected heterozygosities were from 0.039 4 to 0.154 5 and from 0.111 1 to 0.238 5, respectively. Nei＇s genetic distance varied from 0.003 3 to 0.025 3 with an average of 0.013 5. It is suggested that the genetic diversity of R. philippinarum was high.

A Comparative Study of Genetic Variation between Chinese Mitten Crab Eriocheir Sinensis and Hepu Mitten Crab E.Hepuensis

Horizontal starch gel electrophoresis was used to investigate the biochemical genetic structure of Chinese mitten crab Eriocheir sinensis and Hepu mitten crab E.hepuensis. Sixteen putative enzyme-coding loci were examined for forty-nine Chinese mitten crabs and thirty-eight Hepu mitten crabs. Nine loci, AAT-1 *, AAT-2 *, G3PDH *, GPI *, IDHP-1 *, IDHP-2 *, MDH-1 *, MDH-2 * and PGM *, are polymorphic in Chinese mitten crab, and seven, AAT-1 *, AAT-2 *, GPI *, IDHP-1 *, MDH-1 *, MDH-2 * and PGM *, are polymorphic in Hepu mitten crab. The proportion of polymorphic loci and the expected heterozygosity are 0.562 5 and 0.080 3 for Chinese mitten crab, and 0.437 5 and 0.075 4 for Hepu mitten crab. The Nei’s genetic distance between two species is 0.002 4.

Detection of Homozygous Deletions and Mutations in the CDKN2A Gene in Hydatidiform Moles

OBJECTIVE To investigate homozygous deletions and mutations in the CDKN2A gene(p16 INK4a and p14 ARF gene)in hydatidiform moles. METHODS A total of 38 hydatidiform mole samples and 30 villi samples were examined for homozygous deletions in the CDKN2A gene by PCR and for mutations by DHPLC. RESULTS i)Among 38 hydatidiform mole samples, homozygous deletions in the p16 INK4a exon 1 were identified in 5 cases(13.2%),while no homozygous deletions were found in the p16I NK4aexon 1 of 30 early-pregnancy samples.The rates of those deletions in hydatidiform compared to early-pregnancy villi samples was statistically significant(P=0.036).ii)No homozygous deletions in the p14 ARF exon 1 or p16 INK4a exon 2 were found in any of the hydatidiform moles or early-preganancy samples.iii) In all hydatidiform moles and early-pregnancy villi samples,no mutations were detected by DHPLC. CONCLUSION We suggest there may be a close correlation between homozygous deletions in the CDKN2A gene and occurrence of hydatidiform moles variation in the CDKN2A gene is mainly caused by homozygous deletions,while mutations may be not a major cause.

Identification of a novel frameshift mutation in PITX2 gene in a Chinese family with Axenfeld-Rieger syndrome

Objective： Axenfeld-Rieger syndrome （ARS） is phenotypically and genetically heterogeneous. In this study we identified the underlying genetic defect in a Chinese family with ARS. Methods： A detailed family history and clinical data were recorded. The ocular phenotype was documented using slit-lamp photography and systemic anomalies were also documented where available. The genomic DNA was extracted from peripheral blood leukocytes. All coding exons and intron-exon junctions of paired-like homeodomain transcription factor 2 （PITX2） gene and the forkhead box C1 （FOXC1） gene were amplified by polymerase chain reaction （PCR） and screened for mutation by direct DNA sequencing. Variations detected in exon 5 of PITX2 were further evaluated with cloning sequencing. The exon 5 of PITX2 was also sequenced in 100 healthy controls, unrelated to the family, for comparison. Structural models of the wild type and mutant homeodomain of PITX2 were investigated by SWISS-MODEL. Results： Affected individuals exhibited variable ocular phenotypes, whereas the systemic anomalies were similar. After direct sequencing and cloning sequencing, a heterozygous deletion/insertion mutation c. 198_201delinsTTTCT （p.M661fs＊133） was revealed in exon 5 of PITX2. This mutation co-segregated with all affected individuals in the family and was not found either in unaffected family members or in 100 unrelated controls. Conclusions： We detected a novel frameshift mutation p.M661fs＊133 in PITX2 in a Chinese family with ARS. Although PITX2 mutations and polymorphisms have been re- ported from various ethnic groups, we report for the first time the identification of a novel deletion/insertion mutation that causes frameshift mutation in the homeodomain of PITX2 protein.

Homogenization of climate series:The basis for assessing climate changes

Long-term meteorological observation series are fundamental for reflecting climate changes.However,almost all meteorological stations inevitably undergo relocation or changes in observation instruments,rules,and methods,which can result in systematic biases in the observation series for corresponding periods.Homogenization is a technique for adjusting these biases in order to assess the true trends in the time series.In recent years,homogenization has shifted its focus from the adjustments to climate mean status to the adjustments to information about climate extremes or extreme weather.Using case analyses of ideal and actual climate series,here we demonstrate the basic idea of homogenization,introduce new understanding obtained from recent studies of homogenization of climate series in China,and raise issues for further studies in this field,especially with regards to climate extremes,uncertainty of the statistical adjustments,and biased physical relationships among different climate variables due to adjustments in single variable series.