688 research outputs found

    CHARACTERISTIC GROUND REACTION FORCES IN SOFTBALL PITCHING

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    The purpose of this study was to investigate the ground reaction forces of pushing leg and landing leg during softball pitching with windmill style fastball. Four female elite fastpitch softball pitchers served as subjects. A Peak high-speed camera (120Hz) was synchronized with a force plate (600Hz) to collect the parameters of lower extremity during pitching. Results indicated that the higher impulse of pushing leg and the peak slope of landing leg improve softball pitching performance. In addition, the peak ground reaction forces appeared before the human neuromuscular system responded to modify these forces. The greater ground reaction forces created during the landing phase putting a heavy load on lower extremity. It was suggested that the improvement of lower extremities strength would reduce the injury and improve softball pitching performance

    Interaction induced ferro-electricity in the rotational states of polar molecules

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    We show that a ferro-electric quantum phase transition can be driven by the dipolar interaction of polar molecules in the presence a micro-wave field. The obtained ferro-electricity crucially depends on the harmonic confinement potential, and the resulting dipole moment persists even when the external field is turned off adiabatically. The transition is shown to be second order for fermions and for bosons of a smaller permanent dipole moment, but is first order for bosons of a larger moment. Our results suggest the possibility of manipulating the microscopic rotational state of polar molecules by tuning the trap's aspect ratio (and other mesoscopic parameters), even though the later's energy scale is smaller than the former's by six orders of magnitude.Comment: 4 pages and 4 figure

    Stimulation of ribosomal frameshifting by antisense LNA

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    Programmed ribosomal frameshifting is a translational recoding mechanism commonly used by RNA viruses to express two or more proteins from a single mRNA at a fixed ratio. An essential element in this process is the presence of an RNA secondary structure, such as a pseudoknot or a hairpin, located downstream of the slippery sequence. Here, we have tested the efficiency of RNA oligonucleotides annealing downstream of the slippery sequence to induce frameshifting in vitro. Maximal frameshifting was observed with oligonucleotides of 12ā€“18ā€‰nt. Antisense oligonucleotides bearing locked nucleid acid (LNA) modifications also proved to be efficient frameshift-stimulators in contrast to DNA oligonucleotides. The number, sequence and location of LNA bases in an otherwise DNA oligonucleotide have to be carefully manipulated to obtain optimal levels of frameshifting. Our data favor a model in which RNA stability at the entrance of the ribosomal tunnel is the major determinant of stimulating slippage rather than a specific three-dimensional structure of the stimulating RNA element

    Assessing decentralised policy implementation in Vietnam : The case of land recovery and resettlement in the Vung Ang Economic Zone

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    From 2006 plans were implemented to create a deep-sea water port linked to an Economic Zone in the coastal Province of Ha Tinh, located in north central Vietnam. The multi-purpose Zone entitled ā€˜Vung Angā€™, was to attract foreign investors, while the port would provide a link to nearby Laos and Thailand. The project obviously had large implications for the administrations at various levels of governance from Hanoi to the coastal communes and villages, but even more serious impacts on the people living in the affected areas. A large area of about 23,000 hectares was to be cleared, affecting the people of 9 communes, in some of which all inhabitants had to leave their houses and homesteads, to be relocated to completely new settlements about 10 miles inland. These tightly knit communities were not too happy with the prospect to leave their homes and land, the burial places of their ancestors, and the long term comforts of community support networks. While initial decision making process started at the highest levels of Vietnam Governance, the implementation of port and industrial park construction and the related relocation policy was delegated to Ha Tinh province, which is consistent with current decentralisation policies in Vietnam. Actual implementation was carried out by the affected District and Commune level officials ā€“ with support from the Communist Party led Mass Organisations ā€“ who were in charge of the planning and implementation of the relocation process. This entailed a complex and sensitive series of steps to inform affected households, prepare relocation areas and allocate compensation and alternative housing. This paper describes the implementation dynamics of relocation by depicting and assessing the roles of all stakeholders involved, including the impacts - for better or for worse ā€“ of the relocated households. It brings out the way local authorities dealt with affected people, including efforts linked to the ideal of grass-roots democracy. Key areas of contestation are uncovered, such as inadequate infrastructure and low compensation rates. The paper has a second objective to assess the degree to which decentralisation in Vietnam has been actually implemented, and how this affects policy making processes such as the Vung Ang port/industrial zone project. The paper concludes that the relocation policy was implemented in a fairly efficient and harmonious way ā€“ with a very intensive engagement of the entire provincial administrative machinery, but that it is too early to assess the livelihood opportunities of the relocated households

    Near-Infrared Survey and Photometric Redshifts in the Extended GOODS-North field

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    We present deep JJ and HH-band images in the extended Great Observatories Origins Deep Survey-North (GOODS-N) field covering an area of 0.22 deg2\rm{deg}^{2}. The observations were taken using WIRCam on the 3.6-m Canada France Hawaii Telescope (CFHT). Together with the reprocessed KsK_{\rm s}-band image, the 5Ļƒ5\sigma limiting AB magnitudes (in 2" diameter apertures) are 24.7, 24.2, and 24.4 AB mag in the JJ, HH, and KsK_{\rm s} bands, respectively. We also release a multi-band photometry and photometric redshift catalog containing 93598 sources. For non-X-ray sources, we obtained a photometric redshift accuracy ĻƒNMAD=0.036\sigma_{\mathrm{NMAD}}=0.036 with an outlier fraction Ī·=7.3%\eta = 7.3\%. For X-ray sources, which are mainly active galactic nuclei (AGNs), we cross-matched our catalog with the updated 2M-CDFN X-ray catalog from Xue et al. (2016) and found that 658 out of 683 X-ray sources have counterparts. GALEXGALEX UV data are included in the photometric redshift computation for the X-ray sources to give ĻƒNMAD=0.040\sigma_{\mathrm{NMAD}} = 0.040 with Ī·=10.5%\eta=10.5\%. Our approach yields more accurate photometric redshift estimates compared to previous works in this field. In particular, by adopting AGN-galaxy hybrid templates, our approach delivers photometric redshifts for the X-ray counterparts with fewer outliers compared to the 3D-HST catalog, which fit these sources with galaxy-only templates

    Quantum transport in ultracold atoms

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    Ultracold atoms confined by engineered magnetic or optical potentials are ideal systems for studying phenomena otherwise difficult to realize or probe in the solid state because their atomic interaction strength, number of species, density, and geometry can be independently controlled. This review focuses on quantum transport phenomena in atomic gases that mirror and oftentimes either better elucidate or show fundamental differences with those observed in mesoscopic and nanoscopic systems. We discuss significant progress in performing transport experiments in atomic gases, contrast similarities and differences between transport in cold atoms and in condensed matter systems, and survey inspiring theoretical predictions that are difficult to verify in conventional setups. These results further demonstrate the versatility offered by atomic systems in the study of nonequilibrium phenomena and their promise for novel applications.Comment: 24 pages, 7 figures. A revie

    Characterization and System Identification of XY Flexural Mechanism Using Double Parallelogram Manipulator for High Precision Scanning

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    This article represents modeling of double parallelogram flexural manipulator derived from basic classical mechanics theory. Fourth order vibration wave equation is used for mathematical modeling and its performance is determined for step input and sinusoidal forced input. Static characterization of DFM is carried out to determine stiffness and force deflection characteristics over the entire motion range and dynamic characteristics is carried out using Transient response and Frequency response. Transient response is determined using step input to DFM which gives system properties such as damping, rise time and settling time. These parameters are then compared with theoretical model presented previously. Frequency response of DFM system gives characteristics of system with different frequency inputs which is used for experimental modeling of DFM device. Here, Voice Coil Motor is used as Actuator and optical encoder is used for positioning sensing of motion stage. It is noted that theoretical model is having 5% accuracy with experimental results. To achieve better position and accuracy, PID and LQR (Linear Quadratic Regulator) implementation was carried out on experimental model. PID gains are optimally tuned by using Ziegler Nichols approach. PID control is implemented experimentally using dSPACE DS1104 microcontroller and Control Desk software. Experimentally, it is observed that positioning accuracy is less than 5 Ī¼m. Further multiple DFM blocks are arranged for developing XY flexural mechanism and static characterization was carried out on it. The comparison of experimental and FEA results for X-direction and Y-direction is presented at end of paper

    Muscle Expression of Mutant Androgen Receptor Accounts for Systemic and Motor Neuron Disease Phenotypes in Spinal and Bulbar Muscular Atrophy

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    SummaryX-linked spinal and bulbar muscular atrophy (SBMA) is characterized by adult-onset muscle weakness and lower motor neuron degeneration. SBMA is caused by CAG-polyglutamine (polyQ) repeat expansions in the androgen receptor (AR) gene. Pathological findings include motor neuron loss, with polyQ-AR accumulation in intranuclear inclusions. SBMA patients exhibit myopathic features, suggesting a role for muscle in disease pathogenesis. To determine the contribution of muscle, we developed a BAC mouse model featuring a floxed first exon to permit cell-type-specific excision of human AR121Q. BAC fxAR121 mice develop systemic and neuromuscular phenotypes, including shortened survival. After validating termination of AR121 expression and full rescue with ubiquitous Cre, we crossed BAC fxAR121 mice with Human Skeletal Actin-Cre mice. Muscle-specific excision prevented weight loss, motor phenotypes, muscle pathology, and motor neuronopathy and dramatically extended survival. Our results reveal a crucial role for muscle expression of polyQ-AR in SBMA and suggest muscle-directed therapies as effective treatments
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