275 research outputs found
Pertussis Toxin-sensitive Activation of Phospholipase C by the C5a and fMet-Leu-Phe Receptors
Signal transduction pathways that mediate C5a and fMet-Leu-Phe (fMLP)-induced pertussis toxin (PTx)-sensitive activation of phospholipase C (PLC) have been investigated using a cotransfection assay system in COS-7 cells. The abilities of the receptors for C5a and fMLP to activate PLC beta 2 and PLC beta 3 through the Gbeta gamma subunits of endogenous Gi proteins in COS-7 cells were tested because both PLC beta 2 and PLC beta 3 were shown to be activated by the beta gamma subunits of G proteins in in vitro reconstitution assays. Neither of the receptors can activate endogenous PLC beta 3 or recombinant PLC beta 3 in transfected COS-7 cells. However, both receptors can clearly activate PLC beta 2 in a PTx-sensitive manner, suggesting that the receptors may interact with endogenous PTx-sensitive G proteins and activate PLC beta 2 probably through the Gbeta gamma subunits. These findings were further corroborated by the results that PLC beta 3 could only be slightly activated by Gbeta 1gamma 1 or Gbeta 1gamma 5 in the cotransfection assay, whereas the Gbeta gamma subunits strongly activated PLC beta 2 under the same conditions. PLC beta 3 can be activated by Galpha q, Galpha 11, and Galpha 16 in the cotransfection assay. In addition, the Ggamma 2 and Ggamma 3 mutants with substitution of the C-terminal Cys residue by a Ser residue, which can inhibit wild type Gbeta gamma -mediated activation of PLC beta 2, were able to inhibit C5a or fMLP-mediated activation of PLC beta 2. These Ggamma mutants, however, showed little effect on m1-muscarinic receptor-mediated PLC activation, which is mediated by the Gq class of G proteins. These results all confirm that the Gbeta gamma subunits are involved in PLC beta 2 activation by the two chemoattractant receptors and suggest that in COS-7 cells activation of PLC beta 3 by Gbeta gamma may not be the primary pathway for the receptors
Development of a Framework to Support the Effective Adoption of BIM in the Public Sector: Lessons for Ireland
Building Information Modelling (BIM) has been formally adopted by many countries with the promise of creating greater economic, social and sustainability benefits. Several authors and institutions have presented alternative BIM policies and tactics which have been adopted by developed countries. However, there is evidence to indicate that BIM adoption theories are not well established and, in particular, the linkage between BIM public sector adoption strategy outcomes and their contribution to achieving Government policy objectives are underdeveloped. This paper will present the outcome of the first phase of a systematic literature review of published studies (including journal papers and noteworthy international reports) on global government BIM adoption. It will focus primarily on what are the key drivers affecting the decision to adopt BIM at government level, together with the theories, frameworks, and models adopted by governments or public sector bodies to assist in realising the economic, social and sustainability benefits of BIM adoption. The authors reveal a consistency in the drivers associated with the use of BIM in the delivery of public sector construction projects and how these contributed to the establishment of a National BIM Roadmap for Ireland. The methodology focuses on identifying a list of high quality published information of public sector BIM adoption through a rigorous retrieval and filtering system, presenting and critically reviewing alternative government BIM adoption strategies and finally discusses current perceived conclusions and actual implementation frameworks that serve to inform Ireland’s digital transition programme in construction. This paper seeks to inform an early phase in the development of a framework to support the deployment and evaluation of government policy objectives in Ireland and would be applicable to other countries which are an early stage of their digital construction transformation
Ireland’s BIM Macro Adoption Study: Establishing Ireland’s BIM Maturity
Since 2016 the BIM Innovation Capability Programme (BICP) has captured the capability of the Irish Construction Industry’s and the Higher Education Institutes’ (HEIs) response to the increased requirement for BIM on Irish construction and engineering projects. One of the primary responsibilities of the BICP research team is to collate data to assist the National BIM Council of Ireland in the formulation of a National BIM Roadmap. To assist the Council with this task the BICP research team applied five macro BIM maturity conceptual models to assess Ireland’s BIM maturity. The results from the models were further utilised to develop a national BIM adoption policy. The application of the five models helped identify the key policies’ deliverables and the macro maturity components that must be addressed within the initiation and consultation phase of proposing the Irish roadmap. The results also demonstrated the benefits of continuing the BICP initiative into the execution phase of the roadmap, so as to ensure successful integration of its findings within the sector
Public Sector BIM Adoption: Development and Evaluation of Government Policy Interventions: A Systematic Literature Review
Rapid technological advancements in the Architecture, Engineering and Construction (AEC) sector have provided a significant opportunity for improving the industry\u27s efficiency, performance and sustainability. Building Information Modelling (BIM) is an innovative approach to information management in construction that provides a structured methodology for storing and analysing building information exchanged between project stakeholders. However, successful interventions and supports introduced by the public sector in accelerating BIM adoption can be seen through BIM mandates, promotion of information management ISO standards, guidance, funding and procurement integration. In this study, a systematic literature review is adopted to identify BIM policy interventions. The study aims to analyse national BIM interventions with varying degrees of success, compare their general impacts, and identify how the Irish Government could deploy these interventions to address current challenges and establish a formal BIM implementation plan. The outcomes of this study will potentially act as a guideline to industry players for the future development of BIM-based projects
Lipidomic Response to Coffee Consumption
Coffee is widely consumed and contains many bioactive compounds, any of which may impact pathways related to disease development. Our objective was to identify individual lipid changes in response to coffee drinking. We profiled the lipidome of fasting serum samples collected from a previously reported single blinded, three-stage clinical trial. Forty-seven habitual coffee consumers refrained from drinking coffee for 1 month, consumed 4 cups of coffee/day in the second month and 8 cups/day in the third month. Samples collected after each coffee stage were subject to quantitative lipidomic profiling using ion-mobility spectrometry-mass spectrometry. A total of 853 lipid species mapping to 14 lipid classes were included for univariate analysis. Three lysophosphatidylcholine (LPC) species including LPC (20:4), LPC (22:1) and LPC (22:2), significantly decreased after coffee intake (p 0.05); 58 of these decreased after coffee intake. In conclusion, coffee intake leads to lower levels of specific LPC species with potential impacts on glycerophospholipid metabolism more generally.Peer reviewe
The Grism Lens-Amplified Survey from Space (GLASS). IX. The dual origin of low-mass cluster galaxies as revealed by new structural analyses
Using deep Hubble Frontier Fields imaging and slitless spectroscopy from the
Grism Lens-Amplified Survey from Space, we analyze 2200 cluster and 1748 field
galaxies at to determine the impact of environment on galaxy
size and structure at , an unprecedented limit at these
redshifts. Based on simple assumptions--we find no significant
differences in half-light radii () between equal-mass cluster or field
systems. More complex analyses-)-reveal local density
) to induce only a ( confidence) reduction in
beyond what can be accounted for by color, Sersic index (), and
redshift () effects.Almost any size difference between galaxies in high- and
low-density regions is thus attributable to their different distributions in
properties other than environment. Indeed, we find a clear color-
correlation in low-mass passive cluster galaxies () such
that bluer systems have larger radii, with the bluest having sizes consistent
with equal-mass star-forming galaxies. We take this as evidence that
large- low-mass passive cluster galaxies are recently acquired systems
that have been environmentally quenched without significant structural
transformation (e.g., by ram pressure stripping or starvation).Conversely,
of small- low-mass passive cluster galaxies appear to have been
in place since . Given the consistency of the small- galaxies'
stellar surface densities (and even colors) with those of systems more than ten
times as massive, our findings suggest that clusters mark places where galaxy
evolution is accelerated for an ancient base population spanning most masses,
with late-time additions quenched by environment-specific mechanisms are mainly
restricted to the lowest masses.Comment: The accepted version. The catalog is available through the GLASS web
page (http://glass.astro.ucla.edu), or
https://www.astr.tohoku.ac.jp/~mtakahiro/Publication/Morishita17
High-field side scrape-off layer investigation: Plasma profiles and impurity screening behavior in near-double-null configurations
New experiments on Alcator C-Mod reveal that the favorable impurity screening characteristics of the high-field side (HFS) scrape-off layer (SOL), previously reported for single null geometries, is retained in double null configurations, despite the formation of an extremely thin SOL. In balanced double-null, nitrogen injected locally into the HFS SOL is better screened by a factor of 2.5 compared to the same injection into the low field side (LFS) SOL. This result is insensitive to plasma current and Greenwald fraction. Nitrogen injected into the HFS SOL is not as well screened (only a factor of 1.5 improvement over LFS) in unbalanced double-null discharges, when the primary divertor is in the direction of B×∇B. In this configuration, impurity ‘plume’ emission patterns indicate that an opposing E × B drift competes with the parallel impurity flow to the divertor. In balanced double-null plasmas, the dispersal pattern exhibits a dominant E × B motion. Unbalanced discharges with the primary divertor opposite the direction of B×∇B exhibit excellent HFS screening characteristics – a factor of 5 enhancement compared to LFS. These data support the idea that future tokamaks should locate all RF actuators and close-fitting wall structures on the HFS and employ near-double-null magnetic topologies, both to precisely control plasma conditions at the antenna/plasma interface and to maximally mitigate the impact of local impurity sources arising from plasma-material interactions. Keywords:
Alcator C-Mod; Impurity screening; Double null; High field side scrape-off layerUnited States. Department of Energy (Contract DE-FC02-99ER54512
Mixing tone mapping operators on the GPU by differential zone mapping based on psychophysical experiments
© 2016 In this paper, we present a new technique for displaying High Dynamic Range (HDR) images on Low Dynamic Range (LDR) displays in an efficient way on the GPU. The described process has three stages. First, the input image is segmented into luminance zones. Second, the tone mapping operator (TMO) that performs better in each zone is automatically selected. Finally, the resulting tone mapping (TM) outputs for each zone are merged, generating the final LDR output image. To establish the TMO that performs better in each luminance zone we conducted a preliminary psychophysical experiment using a set of HDR images and six different TMOs. We validated our composite technique on several (new) HDR images and conducted a further psychophysical experiment, using an HDR display as the reference that establishes the advantages of our hybrid three-stage approach over a traditional individual TMO. Finally, we present a GPU version, which is perceptually equal to the standard version but with much improved computational performance
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