Haptic-Based Shared-Control Methods for a Dual-Arm System

We propose novel haptic guidance methods for a dual-arm telerobotic manipulation system, which are able to deal with several different constraints, such as collisions, joint limits, and singularities. We combine the haptic guidance with shared-control algorithms for autonomous orientation control and collision avoidance meant to further simplify the execution of grasping tasks. The stability of the overall system in various control modalities is presented and analyzed via passivity arguments. In addition, a human subject study is carried out to assess the effectiveness and applicability of the proposed control approaches both in simulated and real scenarios. Results show that the proposed haptic-enabled shared-control methods significantly improve the performance of grasping tasks with respect to the use of classic teleoperation with neither haptic guidance nor shared control

A multi-ethnic genome-wide association study implicates collagen matrix integrity and cell differentiation pathways in keratoconus

Keratoconus is characterised by reduced rigidity of the cornea with distortion and focal thinning that causes blurred vision, however, the pathogenetic mechanisms are unknown. It can lead to severe visual morbidity in children and young adults and is a common indication for corneal transplantation worldwide. Here we report the first large scale genome-wide association study of keratoconus including 4,669 cases and 116,547 controls. We have identified significant association with 36 genomic loci that, for the first time, implicate both dysregulation of corneal collagen matrix integrity and cell differentiation pathways as primary disease-causing mechanisms. The results also suggest pleiotropy, with some disease mechanisms shared with other corneal diseases, such as Fuchs endothelial corneal dystrophy. The common variants associated with keratoconus explain 12.5% of the genetic variance, which shows potential for the future development of a diagnostic test to detect susceptibility to disease

A missense mutation in ITGB6 causes pitted hypomineralized amelogenesis imperfecta

We identified a family in which pitted hypomineralized amelogenesis imperfecta (AI) with premature enamel failure segregated in an autosomal recessive fashion. Whole-exome sequencing revealed a missense mutation (c.586C>A, p.P196T) in the I-domain of integrin-beta6 (ITGB6), which is consistently predicted to be pathogenic by all available programmes and is the only variant that segregates with the disease phenotype. Furthermore, a recent study revealed that mice lacking a functional allele of Itgb6 display a hypomaturation AI phenotype. Phenotypic characterization of affected human teeth in this study showed areas of abnormal prismatic organization, areas of low mineral density and severe abnormal surface pitting in the tooth's coronal portion. We suggest that the pathogenesis of this form of AI may be due to ineffective ligand binding of ITGB6 resulting in either compromised cell-matrix interaction or compromised ITGB6 activation of transforming growth factor-beta (TGF-beta) impacting indirectly on ameloblast-ameloblast interactions and proteolytic processing of extracellular matrix proteins via MMP20. This study adds to the list of genes mutated in AI and further highlights the importance of cell-matrix interactions during enamel formation

Investigation into the Effect of Replacing Natural Sand by Normalized Crushed Sand on Concrete Performance

International audienc

Mutational Analysis of MIR184 in Sporadic Keratoconus and Myopia

Author version made available in accordance with the publisher's policy.A mutation miR-184(+57C>T) in the seed region of miR-184 (encoded by MIR184 [MIM*613146]) results in familial severe keratoconus combined with early-onset anterior polar cataract and endothelial dystrophy, iris hypoplasia, congenital cataract, and stromal thinning (EDICT) syndrome (MIM#614303). In order to investigate the phenotypic spectrum resulting from MIR184 mutation, MIR184 was sequenced in a keratoconus cohort of mixed ethnicity and a Chinese axial myopia cohort. Sequencing of MIR184 was performed in 780 unrelated keratoconus patients and 96 unrelated Han southern Chinese subjects with axial myopia. Effects of identified mutations on RNA secondary structure were predicted computationally using mFold and RNAFold algorithms. MIR184 amplicons from patients harboring mutations were cloned and transfected into human embryonic kidney 293T (HEK293T) cells, and mature mutant miR-184 expression was analyzed by stem-loop real-time quantitative PCR (RT-qPCR). Two novel heterozygous substitution mutations in MIR184 were identified in the two patients with isolated keratoconus: miR-184(+8C>A) and miR-184(+3A>G). Computational modeling predicted that these mutations would alter the miR-184 stem-loop stability and secondary structure. Ex vivo miR-184 expression analysis demonstrated that miR-184(+8C>A) almost completely repressed the expression of miR-184 (P = 0.022), and miR-184(+3A>G) reduced the expression of miR-184 by approximately 40% (P = 0.002). There was no significant association of rs41280052, which lies within the stem-loop of miR-184, with keratoconus. No MIR184 mutations were detected in the axial myopia cohort. Two novel heterozygous substitution mutations in MIR184 were identified in two patients with isolated keratoconus: miR-184(+8C>A) and miR-184(+3A>G). Mutations in MIR184 are a rare cause of keratoconus and were found in 2 of 780 (0.25%) cases.Supported by Fight for Sight (United Kingdom; JL, CEW); The Research and Development Office, Northern Ireland (RRG Grant 4.46; CEW); Biotechnology and Biological Sciences Research Council, United Kingdom (Grant BB/H005498/1; JG-F, DAS); National Health and Medical Research Council of Australia (KPB, JEC); ALCON India (GG, MD, PS); and The Aravind Eye Care System (GG, MD, PS). JL is a Fight for Sight PhD student

A multi-ethnic genome-wide association study implicates collagen matrix integrity and cell differentiation pathways in keratoconus.

Keratoconus is characterised by reduced rigidity of the cornea with distortion and focal thinning that causes blurred vision, however, the pathogenetic mechanisms are unknown. It can lead to severe visual morbidity in children and young adults and is a common indication for corneal transplantation worldwide. Here we report the first large scale genome-wide association study of keratoconus including 4,669 cases and 116,547 controls. We have identified significant association with 36 genomic loci that, for the first time, implicate both dysregulation of corneal collagen matrix integrity and cell differentiation pathways as primary disease-causing mechanisms. The results also suggest pleiotropy, with some disease mechanisms shared with other corneal diseases, such as Fuchs endothelial corneal dystrophy. The common variants associated with keratoconus explain 12.5% of the genetic variance, which shows potential for the future development of a diagnostic test to detect susceptibility to disease