BcB_c Spectroscopy from Lattice QCD

We present first results for $B_c$ spectroscopy using Lattice Non-Relativistic QCD (NRQCD). For the NRQCD action the leading order spin-dependent and next to leading order spin-independent interactions have been included with tadpole-improved coefficients. We use multi-exponential fits to multiple correlation functions to extract ground and excited $S$ states and give accurate values for the $S$ state hyperfine splitting and the P state ($B^{**}_c$) fine structure, including the effects of $^1P_1/^3P_1$ mixing.Comment: 12 pages uuencoded latex file + 1 postscript figur

Autonomous Locomotion Mode Transition Simulation of a Track-legged Quadruped Robot Step Negotiation

Multi-modal locomotion (e.g. terrestrial, aerial, and aquatic) is gaining increasing interest in robotics research as it improves the robots environmental adaptability, locomotion versatility, and operational flexibility. Within the terrestrial multiple locomotion robots, the advantage of hybrid robots stems from their multiple (two or more) locomotion modes, among which robots can select from depending on the encountering terrain conditions. However, there are many challenges in improving the autonomy of the locomotion mode transition between their multiple locomotion modes. This work proposed a method to realize an autonomous locomotion mode transition of a track-legged quadruped robot steps negotiation. The autonomy of the decision-making process was realized by the proposed criterion to comparing energy performances of the rolling and walking locomotion modes. Two climbing gaits were proposed to achieve smooth steps negotiation behaviours for energy evaluation purposes. Simulations showed autonomous locomotion mode transitions were realized for negotiations of steps with different height. The proposed method is generic enough to be utilized to other hybrid robots after some pre-studies of their locomotion energy performances

Construction and Calibration of a Streaked Optical Spectrometer for Shock Temperature

Here we describe the implementation and calibration of a streaked visible spectrometer (SVS) for optical pyrometry and emission/absorption spectroscopy on light gas gun platforms in the UC Davis Shock Compression Laboratory. The diagnostic consists of an optical streak camera coupled to a spectrometer to provide temporally and spectrally-resolved records of visible emission from dynamically-compressed materials. Fiber optic coupling to the sample enables a small diagnostic footprint on the target face and flexibility of operation on multiple launch systems without the need for open optics. We present the details of calibration (time, wavelength and spectral radiance) for absolute temperature determination and present benchmark measurements of system performance.Comment: 6 pages, 3 figures Davies, E., et al. (accepted). In J. Lane, T. Germann, and M. Armstrong (Eds.), 21st Biennial APS Conference on Shock Compression of Condensed Matter (SCCM19). AIP Publishin

How typical is the Coma cluster?

Coma is frequently used as the archetype z~0 galaxy cluster to compare higher redshift work against. It is not clear, however, how representative the Coma cluster is for galaxy clusters of its mass or X-ray luminosity, and significantly: recent works have suggested that the galaxy population of Coma may be in some ways anomolous. In this work, we present a comparison of Coma to an X-ray selected control sample of clusters. We show that although Coma is typical against the control sample in terms of its internal kinematics (substructure and velocity dispersion profile), it has a significantly high (~3sigma) X-ray temperature set against clusters of comparable mass. By de-redshifting our control sample cluster galaxies star-formation rates using a fit to the galaxy main sequence evolution at z < 0.1, we determine that the typical star-formation rate of Coma galaxies as a function of mass is higher than for galaxies in our control sample at a confidence level of > 99 per cent. One way to alleviate this discrepency and bring Coma in-line with the control sample would be to have the distance to Coma to be slightly lower, perhaps through a non-negligible peculiar velocity with respect to the Hubble expansion, but we do not regard this as likely given precision measurements using a variety of approaches. Therefore in summary, we urge caution in using Coma as a z~0 baseline cluster in galaxy evolution studies.Comment: accepted for publication in MNRA

False memory ≠ false memory: DRM errors are unrelated to the misinformation effect

The DRM method has proved to be a popular and powerful, if controversial, way to study 'false memories'. One reason for the controversy is that the extent to which the DRM effect generalises to other kinds of memory error has been neither satisfactorily established nor subject to much empirical attention. In the present paper we contribute data to this ongoing debate. One hundred and twenty participants took part in a standard misinformation effect experiment, in which they watched some CCTV footage, were exposed to misleading post-event information about events depicted in the footage, and then completed free recall and recognition tests. Participants also completed a DRM test as an ostensibly unrelated filler task. Despite obtaining robust misinformation and DRM effects, there were no correlations between a broad range of misinformation and DRM effect measures (mean r  = -.01). This was not due to reliability issues with our measures or a lack of power. Thus DRM 'false memories' and misinformation effect 'false memories' do not appear to be equivalent

An unusual pi* shape resonance in the near-threshold photoionization of S(1) para-difluorobenzene

Previously reported dramatic changes in photoelectron angular distributions (PADs) as a function of photoelectron kinetic energy following the ionization of S1 p-difluorobenzene are shown to be explained by a shape resonance in the b(2g) symmetry continuum. The characteristics of this resonance are clearly demonstrated by a theoretical multiple-scattering treatment of the photoionization dynamics. New experimental data are presented which demonstrate an apparent insensitivity of the PADs to both vibrational motion and prepared molecular alignment, however, the calculations suggest that strong alignment effects may nevertheless be recognized in the detail of the comparison with experimental data. The apparent, but unexpected, indifference to vibrational excitation is rationalized by considering the nature of the resonance. The correlation of this shape resonance in the continuum with a virtual pi* antibonding orbital is considered. Because this orbital is characteristic of the benzene ring, the existence of similar resonances in related substituted benzenes is discussed.Bellm, SM: Davies, JA: Whiteside, PT; Guo, J: Powis, I; and Reid KL

Elucidating the role of DEPTOR in Alzheimer's disease

This article has been made available through the Brunel Open Access Publishing Fund.The mammalian or mechanistic target of rapamycin (mTOR) is a Ser/Thr protein kinase that, in response to nutrient stimulation, regulates cellular growth, proliferation, survival, protein synthesis and gene transcription. It has also been implicated in Alzheimer's disease (AD) with neuronal cells and hippocampal slices of AD transgenic mice experiencing dysregulated mTOR and synaptic plasticity in response to treatment with the toxic amyloid β (Aβ1-42) peptide, which has been implicated in AD. DEP domain-containing mTOR-interacting protein (DEPTOR) is a protein which can bind to mTOR and cause its inhibition, and functions as a regulatory protein of mTOR to control its activity. The inhibition of mTOR has been shown to have a neuroprotective effect; in an animal model, it was shown to protect against Aβ-induced neurotoxicity. In the present study, to investigate to role of DEPTOR in a model of AD, we neuronally differentiated the SH-SY5Y cell line and examined the effects of treatment with an Aβ42 peptide, thus mimicking plaque formation. This resulted in a significant increase in mTOR and a significant decrease in DEPTOR expression compared to the unstimulated controls. Moreover, to the best of our knowledge, we demonstrate for the first time a reduction in the protein level of DEPTOR in the precentral gyrus, postcentral gyrus and occipital lobe of a brain with AD compared to a normal control, as well as a significant reduction in DEPTOR expression in samples from late-onset AD (LOAD) compared to early-onset familial AD (EOFAD). The reduction in DEPTOR expression in cases of AD compared to healthy controls can lead to an augmentation of mTOR signalling, leading to Aβ accumulation, which in turn leads to a further reduction in DEPTOR expression. This results in the accumulation of amyloid plaque, shifting the balance from neuroprotection to neurodegeneration

Coral symbiodinium community composition across the Belize Mesoamerican barrier reef system is influenced by host species and thermal variability

Accepted manuscrip