1,612 research outputs found

    Investigating volume effects for Nf_f=2 twisted clover fermions at the physical point

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    In this work we present preliminary results on the nucleon axial and tensor charges, the quark momentum fraction and the first moment of the helicity distribution. The simulations have been performed using two Nf=2N_f{=}2 and Nf=2+1+1N_f{=}2{+}1{+}1 ensembles. Both ensembles have a twisted mass action with a clover term with the quark masses fixed at their physical values (physical point) and volumes of 643×12864^3{\times}128. The extracted quantities are compared with results from an existing Nf=2N_f{=}2 (483×9648^3{\times}96) ensemble. This comparison allows one to address volume and quenching effects.Comment: 6 pages, Proceedings of the 36th Annual International Symposium on Lattice Field Theory - LATTICE201

    Cerebellar Motor Learning: When Is Cortical Plasticity Not Enough?

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    Classical Marr-Albus theories of cerebellar learning employ only cortical sites of plasticity. However, tests of these theories using adaptive calibration of the vestibulo–ocular reflex (VOR) have indicated plasticity in both cerebellar cortex and the brainstem. To resolve this long-standing conflict, we attempted to identify the computational role of the brainstem site, by using an adaptive filter version of the cerebellar microcircuit to model VOR calibration for changes in the oculomotor plant. With only cortical plasticity, introducing a realistic delay in the retinal-slip error signal of 100 ms prevented learning at frequencies higher than 2.5 Hz, although the VOR itself is accurate up to at least 25 Hz. However, the introduction of an additional brainstem site of plasticity, driven by the correlation between cerebellar and vestibular inputs, overcame the 2.5 Hz limitation and allowed learning of accurate high-frequency gains. This “cortex-first” learning mechanism is consistent with a wide variety of evidence concerning the role of the flocculus in VOR calibration, and complements rather than replaces the previously proposed “brainstem-first” mechanism that operates when ocular tracking mechanisms are effective. These results (i) describe a process whereby information originally learnt in one area of the brain (cerebellar cortex) can be transferred and expressed in another (brainstem), and (ii) indicate for the first time why a brainstem site of plasticity is actually required by Marr-Albus type models when high-frequency gains must be learned in the presence of error delay

    Regionalism Panel Discussion

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    Regionalism Panel Discussion Featuring: Mr. Jon Cooper, Mr. Ralph Schulz, and Mr. Michael Skipper. Moderated by Mayor Karl Dean. October 7, 201

    An examination of the acceptance of construction and demolition waste reduction measures by residential building contractors in Windsor and Essex County (Ontario).

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    Within the field of urban planning there is a growing recognition that the discipline must incorporate within its existing framework an environmental component that is sensitive to environmental concerns and which takes a proactive role. It is no longer possible to consider development in isolation without first looking at the consequences development has upon the natural and physical environment. The residential construction industry is seen as an industry where opportunity exists to reduce, reuse, recycle and recover material wasted during the construction process. The purpose of this study was to survey new residential building contractors in the Windsor/Essex County area and determine how they had been affected by waste reduction and minimization measures. After surveying 43 residential building contractors, analysis was conducted to determine the impact that waste reduction and minimization practices have had in the Windsor/Essex County area. The results suggest that the contractors surveyed do minimize waste on site for economic rather than environmental reasons. However, waste reduction and minimization literature designed specifically for contractors is not reaching them and the composition of new construction waste is quite different to previous studies done in other municipalities. This study should prove useful to other researchers investigating the issue of construction and demolition waste reduction in Windsor and Essex County area and else where.Dept. of Geography. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1995 .T36. Source: Masters Abstracts International, Volume: 34-02, page: 0622. Adviser: M. Matthew. Thesis (M.A.)--University of Windsor (Canada), 1995

    Modifications of Fabrication of Vibratory Microgyroscopes

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    A micromachining process for the fabrication of vibratory microgyroscopes from silicon wafers, and aspects of the microgyroscope design that are inextricably linked with the fabrication process, have been modified in an effort to increase production yields from perspectives of both quantity and quality. Prior to the modifications, the effective production yield of working microgyroscopes was limited to one or less per wafer. The modifications are part of a continuing effort to improve the design and increase production yields to more than 30 working microgyroscopes per wafer. A discussion of pertinent aspects of the unmodified design and the unmodified fabrication process is prerequisite to a meaningful description of the modifications. The design of the microgyroscope package was not conducive to high yield and rapid testing of many microgyroscopes. One of the major impediments to high yield and testing was found to lie in vibration- isolation beams around the four edges of each microgyroscope, which beams were found to be unnecessary for achieving high resonance quality factors (Q values) characterizing the vibrations of petallike cantilevers. The fabrication process included an 8- m-deep plasma etch. The purpose of the etch was to create 8- m vertical gaps, below which were to be placed large gold evaporated electrodes and sensing pads to drive and sense resonant vibrations of the "petals." The process also included a step in which bridges between dies were cut to separate the dies. The etched areas must be kept clean and smooth (free of debris and spikes), because any object close to 8 m high in those areas would stop the vibrations. However, it was found that after the etch, there remained some spikes with heights that were, variously, almost as high or as high as the etch depth. It also was found that the cutting of bridges created silicon debris, some of which lodged in the 8- m gaps and some of which landed on top of the petals. The masses added to the petals by the debris altered resonance frequencies and/or Q values to unacceptable degrees. Hence, the spikes and the debris have been conjectured to cause most of the observed malfunctions of newly fabricated microgyroscopes. Another pertinent aspect of the unmodified design and process was the fabrication of electrodes and the 8- m capacitance gap on a 500- m-thick wafer, and the fabrication of a 3-mm-thick baseplate from another wafer. It was necessary to bond these wafers to each other in an assembly step that was later found to be superfluous in that it could be eliminated by a suitable modification of the design

    The global warming hiatus: Slowdown or redistribution?

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    Global mean surface temperatures (GMST) exhibited a smaller rate of warming during 1998-2013, compared to the warming in the latter half of the 20th Century. Although, not a "true" hiatus in the strict definition of the word, this has been termed the "global warming hiatus" by IPCC (2013). There have been other periods that have also been defined as the "hiatus" depending on the analysis. There are a number of uncertainties and knowledge gaps regarding the "hiatus." This report reviews these issues and also posits insights from a collective set of diverse information that helps us understand what we do and do not know. One salient insight is that the GMST phenomenon is a surface characteristic that does not represent a slowdown in warming of the climate system but rather is an energy redistribution within the oceans. Improved understanding of the ocean distribution and redistribution of heat will help better monitor Earth's energy budget and its consequences. A review of recent scientific publications on the "hiatus" shows the difficulty and complexities in pinpointing the oceanic sink of the "missing heat" from the atmosphere and the upper layer of the oceans, which defines the "hiatus." Advances in "hiatus" research and outlooks (recommendations) are given in this report

    Accuracy of temperature measurements with the VACM

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    For the past five years the Buoy Group at Woods Hole Oceanographic Institution has included temperature as one of the variables recorded in its current meters. These measurements began with the first successful deployments of Vector Averaging Current Meters (VACMs) in 1971. Circuitry designed for making highly accurate temperature measurements has been included in all the Buoy Project's VACMs. During the past year we have begun to add similar circuitry to the EG&G 850 current meters. This report is intended to describe what we have learned about making water temperature measurements with VACMs.Prepared for the Office of Naval Research under Contract N00014-76-C-0197; NR 083-400

    Predictors of extra-articular manifestations in axial spondyloarthritis and their influence on TNF-inhibitor prescribing patterns:Results from the British Society for Rheumatology Biologics Register in Ankylosing Spondylitis

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    OBJECTIVES: Extra-articular manifestations (EAMs) are important systemic features of axial spondyloarthritis (axSpA), which may influence the choice of tumour necrosis factor-inhibitor (TNFi). We examined the cumulative incidence and predictors of EAMs and the influence of these on first TNFi choice in a 'real-world' cohort of patients with axSpA. METHODS: Clinical and patient-reported outcomes of 2420 patients with axSpA from 83 centres were collected by the British Society for Rheumatology Biologics Register in Ankylosing Spondylitis. Lifestyle factors for EAMs (acute anterior uveitis (AAU), inflammatory bowel diseases (IBD), psoriasis) were compared with those without EAMs. Also, the association between pretreatment EAMs and choice of first TNFi (adalimumab, etanercept, certolizumab) was analysed. RESULTS: AAU was directly associated with human leukocyte antigen (HLA)-B27 (incidence rate ratio (IRR) 1.95, 95% CI 1.40 to 2.73) and inversely associated with ever-smoking (IRR=0.71, 95% CI 0.55 to 0.92). For both psoriasis and IBD, there was an inverse relationship with HLA-B27 (IRR 0.54, 95% CI 0.36 to 0.79 and IRR 0.63, 95% CI 0.43 to 0.91, respectively). A diagnosis of either AAU (OR 3.79, 95% CI 2.11 to 6.80) or IBD (OR 5.50, 95% CI 2.09 to 14.46) was associated with preference for adalimumab versus others. In contrast, a diagnosis of either AAU (OR 0.14, 95% CI 0.06 to 0.33) or IBD (OR 0.17, 95% CI 0.05 to 0.57) was associated with less preference for etanercept over other TNFi. CONCLUSION: The higher occurrence of AAU and lower occurrence of psoriasis and IBD in HLA-B27-positive patients with axSpA are consistent with current pathophysiology. Patients with previous AAU and IBD are more likely to be prescribed adalimumab and less likely to receive etanercept, consistent with the superior efficacy of monoclonal TNFi for these indications. Future work will determine whether EAMs influence TNFi survival, or effectiveness, and whether this varies between agents

    Method of producing an integral resonator sensor and case

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    The present invention discloses an inertial sensor having an integral resonator. A typical sensor comprises a planar mechanical resonator for sensing motion of the inertial sensor and a case for housing the resonator. The resonator and a wall of the case are defined through an etching process. A typical method of producing the resonator includes etching a baseplate, bonding a wafer to the etched baseplate, through etching the wafer to form a planar mechanical resonator and the wall of the case and bonding an end cap wafer to the wall to complete the case
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