排序方式: 共有76条查询结果,搜索用时 15 毫秒
61.
Van Houdt JK Nowakowska BA Sousa SB van Schaik BD Seuntjens E Avonce N Sifrim A Abdul-Rahman OA van den Boogaard MJ Bottani A Castori M Cormier-Daire V Deardorff MA Filges I Fryer A Fryns JP Gana S Garavelli L Gillessen-Kaesbach G Hall BD Horn D Huylebroeck D Klapecki J Krajewska-Walasek M Kuechler A Lines MA Maas S Macdermot KD McKee S Magee A de Man SA Moreau Y Morice-Picard F Obersztyn E Pilch J Rosser E Shannon N Stolte-Dijkstra I Van Dijck P Vilain C Vogels A Wakeling E Wieczorek D 《Nature genetics》2012,44(4):445-9, S1
62.
Rivière JB van Bon BW Hoischen A Kholmanskikh SS O'Roak BJ Gilissen C Gijsen S Sullivan CT Christian SL Abdul-Rahman OA Atkin JF Chassaing N Drouin-Garraud V Fry AE Fryns JP Gripp KW Kempers M Kleefstra T Mancini GM Nowaczyk MJ van Ravenswaaij-Arts CM Roscioli T Marble M Rosenfeld JA Siu VM de Vries BB Shendure J Verloes A Veltman JA Brunner HG Ross ME Pilz DT Dobyns WB 《Nature genetics》2012,44(4):440-4, S1-2
Brain malformations are individually rare but collectively common causes of developmental disabilities. Many forms of malformation occur sporadically and are associated with reduced reproductive fitness, pointing to a causative role for de novo mutations. Here, we report a study of Baraitser-Winter syndrome, a well-defined disorder characterized by distinct craniofacial features, ocular colobomata and neuronal migration defect. Using whole-exome sequencing of three proband-parent trios, we identified de novo missense changes in the cytoplasmic actin-encoding genes ACTB and ACTG1 in one and two probands, respectively. Sequencing of both genes in 15 additional affected individuals identified disease-causing mutations in all probands, including two recurrent de novo alterations (ACTB, encoding p.Arg196His, and ACTG1, encoding p.Ser155Phe). Our results confirm that trio-based exome sequencing is a powerful approach to discover genes causing sporadic developmental disorders, emphasize the overlapping roles of cytoplasmic actin proteins in development and suggest that Baraitser-Winter syndrome is the predominant phenotype associated with mutation of these two genes. 相似文献
63.
Putoux A Thomas S Coene KL Davis EE Alanay Y Ogur G Uz E Buzas D Gomes C Patrier S Bennett CL Elkhartoufi N Frison MH Rigonnot L Joyé N Pruvost S Utine GE Boduroglu K Nitschke P Fertitta L Thauvin-Robinet C Munnich A Cormier-Daire V Hennekam R Colin E Akarsu NA Bole-Feysot C Cagnard N Schmitt A Goudin N Lyonnet S Encha-Razavi F Siffroi JP Winey M Katsanis N Gonzales M Vekemans M Beales PL Attié-Bitach T 《Nature genetics》2011,43(6):601-606
64.
NP-hard Approximation Problems in Overlapping Clustering 总被引:1,自引:1,他引:0
Lp
-norm (p < ∞). These problems also correspond to the approximation by a strongly Robinson dissimilarity or by a dissimilarity fulfilling
the four-point inequality (Bandelt 1992; Diatta and Fichet 1994). The results are extended to circular strongly Robinson dissimilarities,
indexed k-hierarchies (Jardine and Sibson 1971, pp. 65-71), and to proper dissimilarities satisfying the Bertrand and Janowitz (k + 2)-point inequality (Bertrand and Janowitz 1999). Unidimensional scaling (linear or circular) is reinterpreted as a clustering
problem and its hardness is established, but only for the L
1 norm. 相似文献
65.
66.
Jean-Pierre Barthélemy 《Journal of Classification》1988,5(2):229-236
A class of (multiple) consensus methods for n-trees (dendroids, hierarchical classifications) is studied. This class constitutes an extension of the so-called median consensus in the sense that we get two numbersm andm such that: If a clusterX occurs ink n-trees of a profileP, withk m, then it occurs in every consensus n-tree ofP. IfX occurs ink n-trees ofP, withm k <m, then it may, or may not, belong to a consensus n-tree ofP. IfX occurs ink n-trees ofP, withk <m then it cannot occur in any consensus n-tree ofP. If these conditions are satisfied, the multiconsensus function is said to be thresholded by the pair (m,m). Two results are obtained. The first one characterizes the pairs of numbers that can be viewed as thresholds for some consensus function. The second one provides a characterization of thresholded consensus methods. As an application a characterization of the quota rules is provided.
Resume Cet article traite d'une classe de méthodes de consensus (multiples) entre des classifications hiérarchiques. Cette classe est une généralisation du consensus médian dans las mesure oú elle est constituée des méthodes c pour lesquelles il existe deux nombresm etm tels que: Si une classeX appartient ák hiérarchies d'un profilP, aveck m, alorsX appartient á chaque hiérarchie consensus deP. SiX appartient ák hiérarchies deP, avecm k <m, alorsX, peut, ou non, appartenir à une hiérarchie consensus deP. SiX appartient àk hiérarchies deP, aveck <m, alorsX n'appartient á aucune hiérarchie consensus deP. On dit alors que le couple (m,m) est un seuil pour c. Deux résultats sont obtenus. Le premier caractérise les couples de nombres qui sont des seuils de consensus. Le second caractérise les consensus admettant un seuil. Une caractérisation de la régle des quotas est déduite de ce second résultat.相似文献
67.
Bocquet N Nury H Baaden M Le Poupon C Changeux JP Delarue M Corringer PJ 《Nature》2009,457(7225):111-114
Pentameric ligand-gated ion channels from the Cys-loop family mediate fast chemo-electrical transduction, but the mechanisms of ion permeation and gating of these membrane proteins remain elusive. Here we present the X-ray structure at 2.9 A resolution of the bacterial Gloeobacter violaceus pentameric ligand-gated ion channel homologue (GLIC) at pH 4.6 in an apparently open conformation. This cationic channel is known to be permanently activated by protons. The structure is arranged as a funnel-shaped transmembrane pore widely open on the outer side and lined by hydrophobic residues. On the inner side, a 5 A constriction matches with rings of hydrophilic residues that are likely to contribute to the ionic selectivity. Structural comparison with ELIC, a bacterial homologue from Erwinia chrysanthemi solved in a presumed closed conformation, shows a wider pore where the narrow hydrophobic constriction found in ELIC is removed. Comparative analysis of GLIC and ELIC reveals, in concert, a rotation of each extracellular beta-sandwich domain as a rigid body, interface rearrangements, and a reorganization of the transmembrane domain, involving a tilt of the M2 and M3 alpha-helices away from the pore axis. These data are consistent with a model of pore opening based on both quaternary twist and tertiary deformation. 相似文献
68.
Mutations in the human ortholog of Aristaless cause X-linked mental retardation and epilepsy 总被引:20,自引:0,他引:20
Strømme P Mangelsdorf ME Shaw MA Lower KM Lewis SM Bruyere H Lütcherath V Gedeon AK Wallace RH Scheffer IE Turner G Partington M Frints SG Fryns JP Sutherland GR Mulley JC Gécz J 《Nature genetics》2002,30(4):441-445
Mental retardation and epilepsy often occur together. They are both heterogeneous conditions with acquired and genetic causes. Where causes are primarily genetic, major advances have been made in unraveling their molecular basis. The human X chromosome alone is estimated to harbor more than 100 genes that, when mutated, cause mental retardation. At least eight autosomal genes involved in idiopathic epilepsy have been identified, and many more have been implicated in conditions where epilepsy is a feature. We have identified mutations in an X chromosome-linked, Aristaless-related, homeobox gene (ARX), in nine families with mental retardation (syndromic and nonspecific), various forms of epilepsy, including infantile spasms and myoclonic seizures, and dystonia. Two recurrent mutations, present in seven families, result in expansion of polyalanine tracts of the ARX protein. These probably cause protein aggregation, similar to other polyalanine and polyglutamine disorders. In addition, we have identified a missense mutation within the ARX homeodomain and a truncation mutation. Thus, it would seem that mutation of ARX is a major contributor to X-linked mental retardation and epilepsy. 相似文献
69.
FACL4, encoding fatty acid-CoA ligase 4, is mutated in nonspecific X-linked mental retardation 总被引:1,自引:0,他引:1
Meloni I Muscettola M Raynaud M Longo I Bruttini M Moizard MP Gomot M Chelly J des Portes V Fryns JP Ropers HH Magi B Bellan C Volpi N Yntema HG Lewis SE Schaffer JE Renieri A 《Nature genetics》2002,30(4):436-440
X-linked mental retardation (XLMR) is an inherited condition that causes failure to develop cognitive abilities, owing to mutations in a gene on the X chromosome. The latest XLMR update lists up to 136 conditions leading to 'syndromic', or 'specific', mental retardation (MRXS) and 66 entries leading to 'nonspecific' mental retardation (MRX). For 9 of the 66 MRX entries, the causative gene has been identified. Our recent discovery of the contiguous gene deletion syndrome ATS-MR (previously known as Alport syndrome, mental retardation, midface hypoplasia, elliptocytosis, OMIM #300194), characterized by Alport syndrome (ATS) and mental retardation (MR), indicated Xq22.3 as a region containing one mental retardation gene. Comparing the extent of deletion between individuals with ATS-MR and individuals with ATS alone allowed us to define a critical region for mental retardation of approximately 380 kb, containing four genes. Here we report the identification of two point mutations, one missense and one splice-site change, in the gene FACL4 in two families with nonspecific mental retardation. Analysis of enzymatic activity in lymphoblastoid cell lines from affected individuals of both families revealed low levels compared with normal cells, indicating that both mutations are null mutations. All carrier females with either point mutations or genomic deletions in FACL4 showed a completely skewed X-inactivation, suggesting that the gene influences survival advantage. FACL4 is the first gene shown to be involved in nonspecific mental retardation and fatty-acid metabolism. 相似文献
70.
The image contour is segmented into lines, arcs and smooth curves by median filtering of extended direction code. Based on
this segmentation, a set of new local invariant features are proposed to recognize partially occluded objects, which is more
reasonable compared with conventional corner features. The matching results of some typical examples shows that these features
are robust, effective in recognition.
Supported by the National Defence Foundation of China
Wang Yanping: born in Aug. 1937, Professor 相似文献