法律解释方法位序表的元规则

法律解释方法的排序由于缺乏一个元规则而颇受非议。对这些异议的回应迫使我们检讨影响法律解释方法位序的种种因素,并进而探寻隐藏在解释方法位序表背后的元规则。研究表明,可接受性的元规则可以作为法律解释方法排序的始基,并在法律解释中担当起类似法学研究逻辑起点的各项功能。

Quasispecies dynamics in main core epitopes of hepatitis B virus by ultra-deep-pyrosequencing

AIM:To investigate the variability of the main immunodominant motifs of hepatitis B virus(HBV) core gene by ultra-deep-pyrosequencing(UDPS).METHODS:Four samples(2 genotype A and 2 genotype D) from 4 treatment-na ve patients were assessed for baseline variability.Two additional samples from one patient(patient 4,genotype D) were selected for analysis:one sample corresponded to a 36-mo treatment-free period from baseline and the other to the time of viral breakthrough after 18 mo of lamivudine treatment.The HBV region analyzed covered amino acids 40 to 95 of the core gene,and included the two main epitopic regions,Th50-69 and B74-84.UDPS was carried out in the Genome Sequencer FLX system(454 Life Sciences,Roche).After computer filtering of UDPS data based on a Poisson statistical model,122 813 sequences were analyzed.The most conserved position detected by UDPS was analyzed by site-directed mutagenesis and evaluated in cell culture.RESULTS:Positions with highest variability rates were mainly located in the main core epitopes,confirming their role as immune-stimulating regions.In addition,the distribution of variability showed a relationship with HBV genotype.Patient 1(genotype A) presented the lowest variability rates and patient 2(genotype A) had 3 codons with variability higher than 1%.Patient 3 and 4(both genotype D) presented 5 and 8 codons with variability higher than 1%,respectively.The median baseline frequencies showed that genotype A samples had higher variability in epitopic positions than in the other positions analyzed,approaching significance(P = 0.07,sample 1 and P = 0.05,sample 2).In contrast,there were no significant differences in variability between the epitopic and other positions in genotype D cases.Interestingly,patient 1 presented a completely mutated motif from amino acid 64 to 67(E 64 LMT 67),which is commonly recognized by T helper cells.Additionally,the variability observed in all 4 patients was particularly associated with the E 64 LMT 67 motif.Codons 78 and 79 were highly conserved in all samples,in keeping with their involvement in the interaction between the HBV virion capsid and the surface antigens(HBsAg).Of note,codon 76 was even more conserved than codons 78 and 79,suggesting a possible role in HBsAg interactions or even in hepatitis B e antigen conformation.Sequential analysis of samples from patient 4(genotype D) illustrated the dynamism of the HBV quasispecies,with strong selection of one minor baseline variant coinciding with a decrease in core variability during the treatment-free and lamivudinetreated period.The drop in variability seemed to result from a "steady state" situation of the HBV quasispecies after selection of the variant with greatest fitness.CONCLUSION:Host immune pressure seems to be the main cause of HBV core evolution.UDPS analysis is a useful technique for studying viral quasispecies.

Characterization of genic microsatellite markers derived from expressed sequence tags in Pacific abalone (Haliotis discus hannai)

Simple sequence repeat (SSR) markers were developed from the expressed sequence tags (ESTs) of Pacific abalone (Haliotis discus hannai).Repeat motifs were found in 4.95% of the ESTs at a frequency of one repeat every 10.04 kb of EST sequences,after redundancy elimination.Seventeen polymorphic EST-SSRs were developed.The number of alleles per locus varied from 2-17,with an average of 6.8 alleles per locus.The expected and observed heterozygosities ranged from 0.159 to 0.928 and from 0.132 to 0.922,respectively.Twelve of the 17 loci (70.6%) were successfully amplified in H.diversicolor.Seventeen loci segregated in three families,with three showing the presence of null alleles (17.6%).The adequate level of variability and low frequency of null alleles observed in H.discus hannai,together with the high rate of transportability across Haliotis species,make this set of EST-SSR markers an important tool for comparative mapping,marker-assisted selection,and evolutionary studies,not only in the Pacific abalone,but also in related species.

Characterization and fine mapping of the rice blast resistance gene Pia

Blast, caused by Magnaporthe oryzae, is one of the most widespread and destructive diseases of rice. Breeding durable resistant cultivars （cvs） can be achieved by pyramiding of various resistance （R） genes. Pia, carded by cv. Aichi Asahi, was evaluated against 612 isolates of M. oryzae collected from 10 Chinese provinces. The Pia gene expresses weak resistance in all the provinces except for Jiangsu. Genomic position-ready marker-based linkage analysis was carded out in a mapping population consisting of 800 F2 plants derived from a cross of Aichi Asahi×Kasalath. The locus was defined in an interval of approximately 90 kb, flanked by markers A16 and A21. Four candidate genes （Pia-1, Pia-2, Pia-3, and Pia-4）, all having the R gene conserved structure, were predicted in the interval using the cv. Nipponbare genomic sequence. Four candidate resistance gene （CRG） markers （A17, A25, A26, and A27）, derived from the four candidates, were subjected to genotyping with the recombinants detected at the flanking markers. The first three markers completely co-segregated with the Pia locus, and the fourth was absent in the Aichi Asahi genome and disordered with the Pia locus and its flanking markers, indicating that the fourth candidate gene, Pia-4, could be excluded. Co-segregation marker-based genotyping of the three sets of differentials with known R gene genotypes revealed that the genotype of A26 （Pia-3） perfectly matched the R gene genotype of Pia, indicating that Pia-3 is the strongest candidate gene for Pia.

A NOTE ON THE NESTEDNESS PROPERTY FOR ORDERED MEDIAN PROBLEMS IN TREE NETWORKS

The nestedness property has become an increasingly important means for devising efficient algorithms for network location problems.There have been attempts to explore the nestedness property of network location problems with some special cases of the convex ordered median objectives.However,there is little research on the nestedness property for those problems with the concave ordered median objectives.This paper constructs a tree network T and shows that the nestedness property cannot hold for the concave ordered median problem,which fills a gap in the research on the nestedness property.Finally,the authors pose an open problem on identifying the nestedness property for the continuous strategic ordered median problem.