1,225 research outputs found

    Neutron skin and signature of the N = 14 shell gap found from measured proton radii of 17−22N

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    A thick neutron skin emerges from the first determination of root mean square radii of the proton distributions for 17−22N from charge changing cross section measurements around 900A MeV at GSI. Neutron halo effects are signalled for 22N from an increase in the proton and matter radii. The radii suggest an unconventional shell gap at N = 14 arising from the attractive proton–neutron tensor interaction, in good agreement with shell model calculations. Ab initio, in-medium similarity re-normalization group, calculations with a state-of-the-art chiral nucleon–nucleon and three-nucleon interaction reproduce well the data approaching the neutron drip-line isotopes but are challenged in explaining the complete isotopic trend of the radii.The authors are thankful for the support of the GSI accelerator staff and the FRS technical staff for an efficient running of the experiment. The support from NSERC, Canada for this work is gratefully acknowledged. The support of the PR China government and Beihang University under the Thousand Talent program is gratefully acknowledged. The experiment work is partly supported by the grant-in-aid program of the Japanese government under the contract number 23224008. This work is partly supported by Grants-in-Aid for Scientific Research (JP15K05090) of the JSPS of Japan. It is supported by the Office of Nuclear Physics, U.S. Department of Energy (Oak Ridge National Laboratory), DE-SC0008499 (NUCLEI SciDAC collaboration), NERRSC Grant No. 491045-2011, and the Field Work Proposal ERKBP57 at Oak Ridge National Laboratory. Computer time was provided by the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program. TRIUMF receives funding via a contribution through the National Research Council Canada. This research used resources of the Oak Ridge Leadership Computing Facility located in the Oak Ridge National Laboratory, which is supported by the Office of Science of the Department of Energy under Contract No. DE-AC05-00OR22725, and used computational resources of the National Center for Computational Sciences and the National Institute for Computational Sciences. The authors thank B. Davids for a careful reading of the manuscript.S

    Radial Spoke Proteins of \u3cem\u3eChlamydomonas\u3c/em\u3e Flagella

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    The radial spoke is a ubiquitous component of `9+2\u27 cilia and flagella, and plays an essential role in the control of dynein arm activity by relaying signals from the central pair of microtubules to the arms. The Chlamydomonas reinhardtii radial spoke contains at least 23 proteins, only 8 of which have been characterized at the molecular level. Here, we use mass spectrometry to identify 10 additional radial spoke proteins. Many of the newly identified proteins in the spoke stalk are predicted to contain domains associated with signal transduction, including Ca2+-, AKAP- and nucleotide-binding domains. This suggests that the spoke stalk is both a scaffold for signaling molecules and itself a transducer of signals. Moreover, in addition to the recently described HSP40 family member, a second spoke stalk protein is predicted to be a molecular chaperone, implying that there is a sophisticated mechanism for the assembly of this large complex. Among the 18 spoke proteins identified to date, at least 12 have apparent homologs in humans, indicating that the radial spoke has been conserved throughout evolution. The human genes encoding these proteins are candidates for causing primary ciliary dyskinesia, a severe inherited disease involving missing or defective axonemal structures, including the radial spokes

    Effect of Recovery Modality on Rate of Force Development, Vertical Jump, and Lactate Clearance

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    Please refer to the pdf version of the abstract located adjacent to the title

    Mass measurement by track reconstruction with the LEB spectrometer

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    Geometric analysis of satellite laser ranging data

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    The analysis of simultaneous laser data is investigated using the method of trilateration. Analysis of data from 1987 to 1992 is presented with selected baseline rates and station positions. The use of simultaneous Etalon data is simulated to demonstrate the additional global coverage these satellites provide. Trilateration has a great potential for regional deformation studies with monthly LAGEOS American solutions between 3-12 millimeters

    Modelling a wireless connected swarm of mobile robots

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    It is a characteristic of swarm robotics that modelling the overall swarm behaviour in terms of the low-level behaviours of individual robots is very difficult. Yet if swarm robotics is to make the transition from the laboratory to real-world engineering realisation such models would be critical for both overall validation of algorithm correctness and detailed parameter optimisation. We seek models with predictive power: models that allow us to determine the effect of modifying parameters in individual robots on the overall swarm behaviour. This paper presents results from a study to apply the probabilistic modelling approach to a class of wireless connected swarms operating in unbounded environments. The paper proposes a probabilistic finite state machine (PFSM) that describes the network connectivity and overall macroscopic behaviour of the swarm, then develops a novel robot-centric approach to the estimation of the state transition probabilities within the PFSM. Using measured data from simulation the paper then carefully validates the PFSM model step by step, allowing us to assess the accuracy and hence the utility of the model. © Springer Science + Business Media, LLC 2008

    Structure of 12Be: intruder d-wave strength at N=8

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    The breaking of the N=8 shell-model magic number in the 12Be ground state has been determined to include significant occupancy of the intruder d-wave orbital. This is in marked contrast with all other N=8 isotones, both more and less exotic than 12Be. The occupancies of the 0 hbar omega neutron p1/2-orbital and the 1 hbar omega, neutron d5/2 intruder orbital were deduced from a measurement of neutron removal from a high-energy 12Be beam leading to bound and unbound states in 11Be.Comment: 5 pages, 2 figure
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