85 research outputs found

    External sensory-motor cues while managing unexpected slippages can violate the planar covariation law.

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    This study was aimed at investigating the intersegmental coordination of six older adults while managing unexpected slippages delivered during steady walking, and wearing an Active Pelvis Orthosis (APO). The APO was setup either to assist volunteers at the hip levels during balance loss or to be transparent. The Planar Covariation Law (PCL) of the lower limb elevation angles was the main tool used to assess the intersegmental coordination of both limbs (i.e., the perturbed and unperturbed ones). Results revealed that, after the onset of the perturbation, elevation angles of both limbs do not covary, a part from the robot-mediated assistance. These new evidences suggest that external sensory-motor cues can alter the temporal synchronization of elevation angles, thus violating the PCL. (C) 2019 Elsevier Ltd. All rights reserved

    Impaired oxidative stress response characterizes HUWE1-promoted X-linked intellectual disability.

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    Mutations in the HECT, UBA and WWE domain-containing 1 (HUWE1) E3 ubiquitin ligase cause neurodevelopmental disorder X-linked intellectual disability (XLID). HUWE1 regulates essential processes such as genome integrity maintenance. Alterations in the genome integrity and accumulation of mutations have been tightly associated with the onset of neurodevelopmental disorders. Though HUWE1 mutations are clearly implicated in XLID and HUWE1 regulatory functions well explored, currently much is unknown about the molecular basis of HUWE1-promoted XLID. Here we showed that the HUWE1 expression is altered and mutation frequency increased in three different XLID individual (HUWE1 p.R2981H, p.R4187C and HUWE1 duplication) cell lines. The effect was most prominent in HUWE1 p.R4187C XLID cells and was accompanied with decreased DNA repair capacity and hypersensitivity to oxidative stress. Analysis of HUWE1 substrates revealed XLID-specific down-regulation of oxidative stress response DNA polymerase (Pol) λ caused by hyperactive HUWE1 p.R4187C. The subsequent restoration of Polλ levels counteracted the oxidative hypersensitivity. The observed alterations in the genome integrity maintenance may be particularly relevant in the cortical progenitor zones of human brain, as suggested by HUWE1 immunofluorescence analysis of cerebral organoids. These results provide evidence that impairments of the fundamental cellular processes, like genome integrity maintenance, characterize HUWE1-promoted XLID

    Eosinophil Morphology Eosinophil granules and degranulation

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    Endogenous DNA damage is causally associated with the functional decline and transformation of stem cells that characterize aging. DNA lesions that have escaped DNA repair can induce replication stress and genomic breaks that induce senescence and apoptosis. It is not clear how stem and proliferating cells cope with accumulating endogenous DNA lesions and how these ultimately affect the physiology of cells and tissues. Here we have addressed these questions by investigating the hematopoietic system of mice deficient for Rev1, a core factor in DNA translesion synthesis (TLS), the postreplicative bypass of damaged nucleotides. Rev1 hematopoietic stem and progenitor cells displayed compromised proliferation, and replication stress that could be rescued with an antioxidant. The additional disruption of Xpc, essential for global-genome nucleotide excision repair (ggNER) of helix-distorting nucleotide lesions, resulted in the perinatal loss of hematopoietic stem cells, progressive loss of bone marrow, and fatal aplastic anemia between 3 and 4 months of age. This was associated with replication stress, genomic breaks, DNA damage signaling, senescence, and apoptosis in bone marrow. Surprisingly, the collapse of the Rev1Xpc bone marrow was associated with progressive mitochondrial dysfunction and consequent exacerbation of oxidative stress. These data reveal that, to protect its genomic and functional integrity, the hematopoietic system critically depends on the combined activities of repair and replication of helix-distorting oxidative nucleotide lesions by ggNER and Rev1-dependent TLS, respectively. The error-prone nature of TLS may provide mechanistic understanding of the accumulation of mutations in the hematopoietic system upon aging

    The instrument suite of the European Spallation Source

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    An overview is provided of the 15 neutron beam instruments making up the initial instrument suite of the European Spallation Source (ESS), and being made available to the neutron user community. The ESS neutron source consists of a high-power accelerator and target station, providing a unique long-pulse time structure of slow neutrons. The design considerations behind the time structure, moderator geometry and instrument layout are presented. The 15-instrument suite consists of two small-angle instruments, two reflectometers, an imaging beamline, two single-crystal diffractometers; one for macromolecular crystallography and one for magnetism, two powder diffractometers, and an engineering diffractometer, as well as an array of five inelastic instruments comprising two chopper spectrometers, an inverse-geometry single-crystal excitations spectrometer, an instrument for vibrational spectroscopy and a high-resolution backscattering spectrometer. The conceptual design, performance and scientific drivers of each of these instruments are described. All of the instruments are designed to provide breakthrough new scientific capability, not currently available at existing facilities, building on the inherent strengths of the ESS long-pulse neutron source of high flux, flexible resolution and large bandwidth. Each of them is predicted to provide world-leading performance at an accelerator power of 2 MW. This technical capability translates into a very broad range of scientific capabilities. The composition of the instrument suite has been chosen to maximise the breadth and depth of the scientific impact o
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