In this paper a family, called the pivotal family, of distributions is considered.A pivotal family is determined by a generalized pivotal model. Analytical results show that a great many parametric families of distrib...In this paper a family, called the pivotal family, of distributions is considered.A pivotal family is determined by a generalized pivotal model. Analytical results show that a great many parametric families of distributions are pivotal. In a pivotal family of distributions a general method of deriving fiducial distributions of parameters is proposed. In the method a fiducial model plays an important role. A fiducial model is a function of a random variable with a known distribution, called the pivotal random element, when the observation of a statistic is given.The method of this paper includes some other methods of deriving fiducial distributions. Specially the first fiducial distribution given by Fisher can be derived by the method. For the monotone likelihood ratio family of distributions, which is a pivotal family, the fiducial distributions have a frequentist property in the Neyman-Pearson view. Fiducial distributions of regular parametric functions also have the above frequentist property. Some advantages of the fiducial inference are exhibited in four applications of the fiducial distribution. Many examples are given, in which the fiducial distributions cannot be derived by the existing methods.展开更多
Gastric hamartomatous inverted polyps(GHIP)are difficult to diagnose accurately because of inversion into the submucosal layer.GHIP are diagnosed using the pathological characteristics of the tumor,including the fibro...Gastric hamartomatous inverted polyps(GHIP)are difficult to diagnose accurately because of inversion into the submucosal layer.GHIP are diagnosed using the pathological characteristics of the tumor,including the fibroblast cells,smooth muscle,nerve components,glandular hyperplasia,and cystic gland dilatation.Although Peutz-Jeghers syndrome,juvenile polyposis,and Cowden disease are hereditary,it is rare to encounter 2 cases of monostotic and asymptomatic gastric hamartomas.The pathogeneses of hamartomatous inverted polyps and inverted hyperplastic polyps remain controversial because of the paucity of reported cases.There are 3 hypotheses regarding the pathogenesis of complete gastric inverted polyps.Based on our experience with 2 successive,rare GHIP cases,we affirm the hypothesis that after a hamartomatous change occurs in the submucosal layer,some of these components are exposed to the gastric mucosa and,consequently,form a hypertrophic lesion.In Case 1,our hypothesis explains why a tiny hypertrophic change was first detected on the top of the submucosal tumor using a detailed narrow band imaging-magnified endoscopy.There was no confirmation that the milky white mucous and calcification structures were exuding directly from the biopsy site like Case 1,and in Case 2 the presence of this mucous was indirectly confirmed during an endoscopic submucosal dissection(ESD).Regarding the pathogenesis of GHIP,a submucosal hamartomatous change may occur prior to the growth of hypertrophic portions.An en bloc resection using ESD is recommended for treatment.展开更多
Ciliated protists represent one of the most primitive and diverse lineages of eukaryotes,with nuclear dimorphism,a distinctive sexual process(conjugation),and extensive genome rearrangements.Among divergent ciliate li...Ciliated protists represent one of the most primitive and diverse lineages of eukaryotes,with nuclear dimorphism,a distinctive sexual process(conjugation),and extensive genome rearrangements.Among divergent ciliate lineages,the peritrich order Sessilida includes members with a colonial lifestyle,which may hint to an independent evolutionary attempt for multicellularity,although they are still single-celled organisms.To date,the evolution and phylogeny of this group are still far from clear,in part due to the paucity of molecular and/or morphological data for many taxa.In this study,we extend taxon sampling of a loricate group of sessilids by obtaining 69 new r DNA(SSU r DNA,ITS1-5.8S rDNA-ITS2,and LSU r DNA)sequences from 20 wellcharacterized representative species and analyze the phylogenetic relationships within Sessilida.The main findings are:(i)the genera Rhabdostyla and Campanella each represents a unique taxon at family level,supporting the establishment of two new families,i.e.,Rhabdostylidae n.fam.and Campanellidae n.fam.,respectively,the former being sister to a morphologically heterogeneous clade comprising Astylozoidae and several incertae sedis species and the latter occupying the basal position within the Sessilida clade;(ii)the structure of infundibular polykinety 3 is likely to be a phylogenetically informative character for resolving evolutionary relationships among sessilids;(iii)differences between sparsely and the densely arranged silverline systems could be a suprageneric taxonomic character;(iv)the monophyly of Vaginicolidae is confirmed,which is consistent with its specialized morphology,i.e.,the possession of a typical peritrich lorica which might be an apomorphy for this group;(v)within Vaginicolidae,the monotypic Cothurniopsis sensu Stokes,1893 is a synonym of Cothurnia Ehrenberg,1831,and a new combination is created,i.e.,Cothurnia valvata nov.comb.;(vi)Vaginicola sensu lato comprises at least two distinctly divergent clades,one affiliated with Thuricola and the other with a systematicall展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.10271013,10071090).
文摘In this paper a family, called the pivotal family, of distributions is considered.A pivotal family is determined by a generalized pivotal model. Analytical results show that a great many parametric families of distributions are pivotal. In a pivotal family of distributions a general method of deriving fiducial distributions of parameters is proposed. In the method a fiducial model plays an important role. A fiducial model is a function of a random variable with a known distribution, called the pivotal random element, when the observation of a statistic is given.The method of this paper includes some other methods of deriving fiducial distributions. Specially the first fiducial distribution given by Fisher can be derived by the method. For the monotone likelihood ratio family of distributions, which is a pivotal family, the fiducial distributions have a frequentist property in the Neyman-Pearson view. Fiducial distributions of regular parametric functions also have the above frequentist property. Some advantages of the fiducial inference are exhibited in four applications of the fiducial distribution. Many examples are given, in which the fiducial distributions cannot be derived by the existing methods.
文摘Gastric hamartomatous inverted polyps(GHIP)are difficult to diagnose accurately because of inversion into the submucosal layer.GHIP are diagnosed using the pathological characteristics of the tumor,including the fibroblast cells,smooth muscle,nerve components,glandular hyperplasia,and cystic gland dilatation.Although Peutz-Jeghers syndrome,juvenile polyposis,and Cowden disease are hereditary,it is rare to encounter 2 cases of monostotic and asymptomatic gastric hamartomas.The pathogeneses of hamartomatous inverted polyps and inverted hyperplastic polyps remain controversial because of the paucity of reported cases.There are 3 hypotheses regarding the pathogenesis of complete gastric inverted polyps.Based on our experience with 2 successive,rare GHIP cases,we affirm the hypothesis that after a hamartomatous change occurs in the submucosal layer,some of these components are exposed to the gastric mucosa and,consequently,form a hypertrophic lesion.In Case 1,our hypothesis explains why a tiny hypertrophic change was first detected on the top of the submucosal tumor using a detailed narrow band imaging-magnified endoscopy.There was no confirmation that the milky white mucous and calcification structures were exuding directly from the biopsy site like Case 1,and in Case 2 the presence of this mucous was indirectly confirmed during an endoscopic submucosal dissection(ESD).Regarding the pathogenesis of GHIP,a submucosal hamartomatous change may occur prior to the growth of hypertrophic portions.An en bloc resection using ESD is recommended for treatment.
基金supported by the Laoshan Laboratory(LSKJ202203201)the National Natural Science Foundation of China(32030015,41976086,32270558,32111530116)+2 种基金Young Taishan Scholar Program of Shandong Province(tsqn202103037)the Fundamental Research Funds for the Central Universities(202141007)the China Postdoctoral Science Foundation(2021M703037)。
文摘Ciliated protists represent one of the most primitive and diverse lineages of eukaryotes,with nuclear dimorphism,a distinctive sexual process(conjugation),and extensive genome rearrangements.Among divergent ciliate lineages,the peritrich order Sessilida includes members with a colonial lifestyle,which may hint to an independent evolutionary attempt for multicellularity,although they are still single-celled organisms.To date,the evolution and phylogeny of this group are still far from clear,in part due to the paucity of molecular and/or morphological data for many taxa.In this study,we extend taxon sampling of a loricate group of sessilids by obtaining 69 new r DNA(SSU r DNA,ITS1-5.8S rDNA-ITS2,and LSU r DNA)sequences from 20 wellcharacterized representative species and analyze the phylogenetic relationships within Sessilida.The main findings are:(i)the genera Rhabdostyla and Campanella each represents a unique taxon at family level,supporting the establishment of two new families,i.e.,Rhabdostylidae n.fam.and Campanellidae n.fam.,respectively,the former being sister to a morphologically heterogeneous clade comprising Astylozoidae and several incertae sedis species and the latter occupying the basal position within the Sessilida clade;(ii)the structure of infundibular polykinety 3 is likely to be a phylogenetically informative character for resolving evolutionary relationships among sessilids;(iii)differences between sparsely and the densely arranged silverline systems could be a suprageneric taxonomic character;(iv)the monophyly of Vaginicolidae is confirmed,which is consistent with its specialized morphology,i.e.,the possession of a typical peritrich lorica which might be an apomorphy for this group;(v)within Vaginicolidae,the monotypic Cothurniopsis sensu Stokes,1893 is a synonym of Cothurnia Ehrenberg,1831,and a new combination is created,i.e.,Cothurnia valvata nov.comb.;(vi)Vaginicola sensu lato comprises at least two distinctly divergent clades,one affiliated with Thuricola and the other with a systematicall
