331 research outputs found
An evolve-then-correct reduced order model for hidden fluid dynamics
In this paper, we put forth an evolve-then-correct reduced order modeling
approach that combines intrusive and nonintrusive models to take hidden
physical processes into account. Specifically, we split the underlying dynamics
into known and unknown components. In the known part, we first utilize an
intrusive Galerkin method projected on a set of basis functions obtained by
proper orthogonal decomposition. We then formulate a recurrent neural network
emulator based on the assumption that observed data is a manifestation of all
relevant processes. We further enhance our approach by using an orthonormality
conforming basis interpolation approach on a Grassmannian manifold to address
off-design conditions. The proposed framework is illustrated here with the
application of two-dimensional co-rotating vortex simulations under modeling
uncertainty. The results demonstrate highly accurate predictions underlining
the effectiveness of the evolve-then-correct approach toward realtime
simulations, where the full process model is not known a priori
Qlusty: Quick and dirty generation of event videos from written media coverage
Qlusty generates videos describing the coverage of the same event by different news outlets automatically. Throughout four modules it identifies events, de-duplicates notes, ranks according to coverage, and queries for images to generate an overview video. In this manuscript we present our preliminary models, including quantitative evaluations of the former two and a qualitative analysis of the latter two. The results show the potential for achieving our main aim: contributing in breaking the information bubble, so common in the current news landscape
Electron irradiation induced reduction of the permittivity in chalcogenide glass (As2S3) thin film
We investigate the effect of electron beam irradiation on the dielectric
properties of As2S3 Chalcogenide glass. By means of low-loss Electron Energy
Loss Spectroscopy, we derive the permittivity function, its dispersive
relation, and calculate the refractive index and absorption coefficients under
the constant permeability approximation. The measured and calculated results
show, to the best of our knowledge, a heretofore unseen phenomenon: the
reduction in the permittivity of <40%, and consequently a modification of the
refractive index follows, reducing it by 20%, hence suggesting a significant
change on the optical properties of the material. The plausible physical
phenomena leading to these observations are discussed in terms of the homopolar
and heteropolar bond dynamics under high energy absorption.Comment: 22 pages, 7 figures, manuscript in preparation to send to Physical
Review
Selective IgA Deficiency in Spontaneously Hypertensive Rats With Gut Dysbiosis
BACKGROUND: The spontaneously hypertensive rat (SHR) is extensively used to study hypertension. Gut microbiota dysbiosis is a notable feature in SHR for reasons unknown. Immunoglobulin A (IgA) is a major host factor required for gut microbiota homeostasis. We hypothesized that inadequate IgA contributes to gut microbiota dysbiosis in SHR.
METHODS: IgA was measured in feces, cecum, serum, liver, gut-associated lymphoid tissue, and milk from SHR and Wistar Kyoto rats. IgA regulatory factors like IgM, IgG, and
RESULTS: Compared with Wistar Kyoto rats, SHR displayed remarkably near-deficient IgA levels accompanied by compensatory increases in serum IgM and IgG and gut-liver
CONCLUSIONS: This study is the first to reveal IgA deficiency in SHR as one host factor associated with gut microbiota dysbiosis and invigorates future research to determine the pathophysiological role of IgA in hypertension
The dynamics of ecological sustainability in housing delivery: Developers’ perspectives
Housing delivery is facing substantial environmental sustainability threats. Consequently, the housing industry is constantly adopting broad-based actions to sustain the environment and make delivery more efficient and risk-averse. Such regulatory models are sometimes targeted at the housing developers’ readiness, the dimensions of market volatility, technology, and the firm's resources. These variables are more profound within an emerging economic context such as Malaysia, and previous research investigating sustainability agenda in housing delivery has neglected their impacts within the housing developer's perspective. This study tested regional-scale hypotheses regarding predictors of ecological sustainability across the state of Sarawak Malaysia. It was hypothesised that the critical dynamics of technology, developer's readiness, resources, regulatory framework, market turbulence, and uncertainty would increase the likelihood of cumulative environmental sustainability in housing delivery. A sample of 221 Housing developers registered under the Sarawak Housing and Real Estate Developers’ Association and allied professionals were sent a self-report online survey instrument, and 144 completed questionnaires were returned, indicating a 65 per cent response rate. Subsequently, SPSS and SmartPLS were used for data analysis. SPSS was used for data screening, while SmartPLS was used to assess the measurement and structural models. Structural equation models show that improved technology, developer's readiness, and regulatory apparatus are the better correlated with environmental sustainability performance
Sphingosine 1-Phosphate Receptor Modulator Fingolimod (FTY720) Attenuates Myocardial Fibrosis in Post-heterotopic Heart Transplantation
Background and Objective: Sphingosine 1-phosphate (S1P), and S1P receptor modulator fingolimod have been suggested to play important cardioprotective role in animal models of myocardial ischemia/reperfusion injuries. To understand the cardioprotective function of S1P and its mechanism in vivo, we analyzed apoptotic, inflammatory biomarkers, and myocardial fibrosis in an in vivo heterotopic rat heart transplantation model.Methods: Heterotopic heart transplantation is performed in 60 Sprague–Dawley (SD) rats (350–400 g). The heart transplant recipients (n = 60) are categorized into Group A (control) and Group B (fingolimod treated 1 mg/kg intravenous). At baseline with 24 h after heart transplantation, blood and myocardial tissue are collected for analysis of myocardial biomarkers, apoptosis, inflammatory markers, oxidative stress, and phosphorylation of Akt/Erk/STAT-3 signaling pathways. Myocardial fibrosis was investigated using Masson’s trichrome staining and L-hydroxyline.Results: Fingolimod treatment activates both Reperfusion Injury Salvage Kinase (RISK) and Survivor Activating Factor Enhancement (SAFE) pathways as evident from activation of anti-apoptotic and anti-inflammatory pathways. Fingolimod treatment caused a reduction in myocardial oxidative stress and hence cardiomyocyte apoptosis resulting in a decrease in myocardial reperfusion injury. Moreover, a significant (p < 0.001) reduction in collagen staining and hydroxyproline content was observed in fingolimod treated animals 30 days after transplantation demonstrating a reduction in cardiac fibrosis.Conclusion: S1P receptor activation with fingolimod activates anti-apoptotic and anti-inflammatory pathways, leading to improved myocardial salvage causing a reduction in cardiac fibrosis
Discrimination as a One-Day Performance Critically Reviewing an Anti-racism Day at School
Peer reviewe
Developing an Individual-level Geodemographic Classification
Geodemographics is a spatially explicit classification of socio-economic data, which can be used to describe and analyse individuals by where they live. Geodemographic information is used by the public sector for planning and resource allocation but it also has considerable use within commercial sector applications. Early geodemographic systems, such as the UK’s ACORN (A Classification of Residential Neighbourhoods), used only area-based census data, but more recent systems have added supplementary layers of information, e.g. credit details and survey data, to provide better discrimination between classes. Although much more data has now become available, geodemographic systems are still fundamentally built from area-based census information. This is partly because privacy laws require release of census data at an aggregate level but mostly because much of the research remains proprietary. Household level classifications do exist but they are often based on regressions between area and household data sets. This paper presents a different approach for creating a geodemographic classification at the individual level using only census data. A generic framework is presented, which classifies data from the UK Census Small Area Microdata and then allocates the resulting clusters to a synthetic population created via microsimulation. The framework is then applied to the creation of an individual-based system for the city of Leeds, demonstrated using data from the 2001 census, and is further validated using individual and household survey data from the British Household Panel Survey
Status of Muon Collider Research and Development and Future Plans
The status of the research on muon colliders is discussed and plans are
outlined for future theoretical and experimental studies. Besides continued
work on the parameters of a 3-4 and 0.5 TeV center-of-mass (CoM) energy
collider, many studies are now concentrating on a machine near 0.1 TeV (CoM)
that could be a factory for the s-channel production of Higgs particles. We
discuss the research on the various components in such muon colliders, starting
from the proton accelerator needed to generate pions from a heavy-Z target and
proceeding through the phase rotation and decay ()
channel, muon cooling, acceleration, storage in a collider ring and the
collider detector. We also present theoretical and experimental R & D plans for
the next several years that should lead to a better understanding of the design
and feasibility issues for all of the components. This report is an update of
the progress on the R & D since the Feasibility Study of Muon Colliders
presented at the Snowmass'96 Workshop [R. B. Palmer, A. Sessler and A.
Tollestrup, Proceedings of the 1996 DPF/DPB Summer Study on High-Energy Physics
(Stanford Linear Accelerator Center, Menlo Park, CA, 1997)].Comment: 95 pages, 75 figures. Submitted to Physical Review Special Topics,
Accelerators and Beam
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