529 research outputs found

    Prediction of naturally-occurring, industrially-induced and total trans fatty acids in butter, dairy spreads and Cheddar cheese using vibrational spectroscopy and multivariate data analysis

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    peer-reviewedThis study investigated the use of vibrational spectroscopy [near infrared (NIR), Fourier-transform mid-infrared (FT-MIR), Raman] and multivariate data analysis for (1) quantifying total trans fatty acids (TT), and (2) separately predicting naturally-occurring (NT; i.e., C16:1 t9; C18:1 trans-n, n = 6 … 9, 10, 11; C18:2 trans) and industrially-induced trans fatty acids (IT = TT – NT) in Irish dairy products, i.e., butter (n = 60), Cheddar cheese (n = 44), and dairy spreads (n = 54). Partial least squares regression models for predicting NT, IT and TT in each type of dairy product were developed using FT-MIR, NIR and Raman spectral data. Models based on NIR, FT-MIR and Raman spectra were used for the prediction of NT and TT content in butter; best prediction performance achieved a coefficient of determination in validation (R2V) ∼ 0.91–0.95, root mean square error of prediction (RMSEP) ∼ 0.07–0.30 for NT; R2V ∼ 0.92–0.95, RMSEP ∼ 0.23–0.29 for TT.This project was funded by the Irish Department of Agriculture, Food and the Marine as part of CheeseBoard 2015. Ming Zhao is a Teagasc Walsh Fellow

    A partition approach for underwater explosion based on smoothed particle method

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    As a Lagrangian particle method, smoothed particle hydrodynamics (SPH) has been applied into the problems of fluid-structure interaction (FSI) more and more. However, the transient fluid-structure interactions characterized by severe reactions and wide spreads are very expensive to be carried out with three-dimensional SPH method due to the approach of solid modeling, especially when the structure is subjected to the shock loads from mid-field or far-field, which is almost impossible to achieve. Therefore, based on the previous research, the coupled SPH-BEM method is put forward and applied to underwater explosion in this paper. The structure is modeled and solved with SPH method while the fluid boundary only required is coped with a boundary element method (BEM), the second-order doubly asymptotic approximations (DAA2). The FSI method will reduce the elements of structures and fluid greatly so as to solve the problems of fluid-structure interactions feasibly and efficiently. The mid-plane of a plate only discretized into a layer of particles is taken as the study object in the SPH shell element and the related physical quantities is integrated in the thickness direction to capture the dynamic response of structures; the fluid boundary only discretized into a piece of boundary elements is employed in the BEM method to solve fluid dynamics based on the retarded potential equation; treatments of the coupled fluid-structure interface are made to satisfy the compatibility conditions and the messages related to motions and loads are well delivered. Finally, two standard examples are carried out to test the above algorithm

    Impacts of sea level rise on hypoxia in the Chesapeake Bay: A model intercomparison

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    Over recent years a number of studies have examined the effects of sea level rise (SLR) on hypoxia in Chesapeake Bay. However, variations in the methodology, the years considered, and the metrics reported made comparisons between these studies difficult. To clarify the effects of SLR on the Bay’s hypoxia, we present an intercomparison between four numerical models following a common methodology. The models share the riverine fluxes, baseline period (1991–1995), and consider the same three scenarios of SLR: an increase in sea level of 0.17m, 0.50m, and 1.00m (representative of years 2025, 2050 and 2100, respectively). SLR is the sole climate driver considered in these experiments

    Multi-phase SPH modelling of air effect on the dynamic flooding of a damaged cabin

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    The air flow may take effects on the responses of the damaged ship in the dynamic flooding process. It not only relates to the amount of inflow but also the stability of the ship. In order to accurately predict the responses of a damaged ship, it is essential to take the air into account. In this study, a multi-phase SPH model combined with a dummy boundary method is proposed. One of the advantages of the new SPH model in solving this nonlinear problem is that, it does not rely on other algorithms to track the interface of different phases but can easily deal with breaking, splashing and mixing. The stability and accuracy of the numerical model are verified by comparing with experimental and published numerical results. The air captured in the flooding process is further studied with focus on the exchange of air and water near the opening. Finally, the effects of the sizes and number of the deck openings on the air flow are analyzed. It is found that the air flow can reduce the kinematic energy of inflow water, leading to decreases in the dynamic moment formed by the flooding water and sinking rate of damaged cabin

    Interplay of quantum magnetic and potential scattering around Zn or Ni impurity ions in superconducting cuprates

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    To describe the scattering of superconducting quasiparticles from non-magnetic (Zn) or magnetic (Ni) impurities in optimally doped high Tc_c cuprates, we propose an effective Anderson model Hamiltonian of a localized electron hybridizing with dx2y2d_{x^2-y^2}-wave BCS type superconducting quasiparticles with an attractive scalar potential at the impurity site. Due to the strong local antiferromagnetic couplings between the original Cu ions and their nearest neighbors, the localized electron in the Ni-doped materials is assumed to be on the impurity sites, while in the Zn-doped materials the localized electron is distributed over the four nearest neighbor sites of the impurities with a dominant dx2y2d_{x^2-y^2} symmetric form of the wave function. With Ni impurities, two resonant states are formed above the Fermi level in the local density of states at the impurity site, while for Zn impurities a sharp resonant peak below the Fermi level dominates in the local density of states at the Zn site, accompanied by a small and broad resonant state above the Fermi level mainly induced by the potential scattering. In both cases, there are no Kondo screening effects. The local density of states and their spatial distribution at the dominant resonant energy around the substituted impurities are calculated for both cases, and they are in good agreement with the experimental results of scanning tunneling microscopy in Bi2_2Sr2_2CaCu2_2O8+δ_{8+\delta} with Zn or Ni impurities, respectively.Comment: 24 pages, Revtex, 8 figures, submitted to Physical Review B for publication. Sub-ject Class: Superconductivity; Strongly Correlated Electron

    Challenges associated with modeling low-oxygen waters in Chesapeake Bay: a multiple model comparison

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    As three-dimensional (3-D) aquatic ecosystem models are used more frequently for operational water quality forecasts and ecological management decisions, it is important to understand the relative strengths and limitations of existing 3-D models of varying spatial resolution and biogeochemical complexity. To this end, 2-year simulations of the Chesapeake Bay from eight hydrodynamic-oxygen models have been statistically compared to each other and to historical monitoring data. Results show that although models have difficulty resolving the variables typically thought to be the main drivers of dissolved oxygen variability (stratification, nutrients, and chlorophyll), all eight models have significant skill in reproducing the mean and seasonal variability of dissolved oxygen. In addition, models with constant net respiration rates independent of nutrient supply and temperature reproduced observed dissolved oxygen concentrations about as well as much more complex, nutrient-dependent biogeochemical models. This finding has significant ramifications for short-term hypoxia forecasts in the Chesapeake Bay, which may be possible with very simple oxygen parameterizations, in contrast to the more complex full biogeochemical models required for scenario-based forecasting. However, models have difficulty simulating correct density and oxygen mixed layer depths, which are important ecologically in terms of habitat compression. Observations indicate a much stronger correlation between the depths of the top of the pycnocline and oxycline than between their maximum vertical gradients, highlighting the importance of the mixing depth in defining the region of aerobic habitat in the Chesapeake Bay when low-oxygen bottom waters are present. Improvement in hypoxia simulations will thus depend more on the ability of models to reproduce the correct mean and variability of the depth of the physically driven surface mixed layer than the precise magnitude of the vertical density gradient

    The Role of Parvalbumin-positive Interneurons in Auditory Steady-State Response Deficits in Schizophrenia

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    © The Author(s) 2019. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Despite an increasing body of evidence demonstrating subcellular alterations in parvalbumin-positive (PV+) interneurons in schizophrenia, their functional consequences remain elusive. Since PV+ interneurons are involved in the generation of fast cortical rhythms, these changes have been hypothesized to contribute to well-established alterations of beta and gamma range oscillations in patients suffering from schizophrenia. However, the precise role of these alterations and the role of different subtypes of PV+ interneurons is still unclear. Here we used a computational model of auditory steady-state response (ASSR) deficits in schizophrenia. We investigated the differential effects of decelerated synaptic dynamics, caused by subcellular alterations at two subtypes of PV+ interneurons: basket cells and chandelier cells. Our simulations suggest that subcellular alterations at basket cell synapses rather than chandelier cell synapses are the main contributor to these deficits. Particularly, basket cells might serve as target for innovative therapeutic interventions aiming at reversing the oscillatory deficits.Peer reviewe

    Beyond the pandemic : COVID-19 pandemic changed the face of life

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    Funding Information: This work was supported by the Swedish Research Council Vetenskapsr?det (VR grant 2016?05885). Funding Information: Acknowledgments: H.R. El-Seedi is very grateful to the Swedish Research links grant VR 2016– 05885 and the Department of Molecular Biosciences, Wenner-Grens Institute, Stockholm University, Sweden, for the financial support. Publisher Copyright: © 2021 by the au-thors. Licensee MDPI, Basel, Switzerland.The COVID-19 pandemic is a serious challenge for societies around the globe as entire populations have fallen victim to the infectious spread and have taken up social distancing. In many countries, people have had to self-isolate and to be confined to their homes for several weeks to months to prevent the spread of the virus. Social distancing measures have had both negative and positive impacts on various aspects of economies, lifestyles, education, transportation, food supply, health, social life, and mental wellbeing. On other hands, due to reduced population movements and the decline in human activities, gas emissions decreased and the ozone layer improved; this had a positive impact on Earth’s weather and environment. Overall, the COVID-19 pandemic has negative effects on human activities and positive impacts on nature. This study discusses the impact of the COVID-19 pandemic on different life aspects including the economy, social life, health, education, and the environment.publishersversionPeer reviewe

    Clinical Outcome Following Stringent Discontinuation of Dual Antiplatelet Therapy After 12 Months in Real-World Patients Treated With Second-Generation Zotarolimus-Eluting Resolute and Everolimus-Eluting Xience V Stents : 2-Year Follow-Up of the Randomized TWENTE Trial

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    Objectives The aim of this study was to assess the safety and efficacy of the implantation of Resolute zotarolimus-eluting stents (ZES) (Medtronic Inc., Santa Rosa, California) and Xience V everolimus-eluting stents (EES) (Abbott Vascular, Santa Clara, California) following strict discontinuation of dual antiplatelet therapy (DAPT) after 12 months. Background Only limited long-term follow-up data are available from head-to-head comparisons of second-generation drug-eluting stents. Methods The randomized TWENTE (The Real-World Endeavor Resolute Versus Xience V Drug-Eluting Stent Study in Twente) trial is an investigator-initiated study performed in a population with many complex patients and lesions and only limited exclusion criteria. Patients were randomly assigned 1:1 to ZES (n = 697) or EES (n = 694). Results Two-year follow-up information was available on all patients. The rate of continuation of DAPT beyond 12 months was very low (5.4%). The primary endpoint of target vessel failure, a composite of cardiac death, target vessel–related myocardial infarction, and target vessel revascularization, did not differ between ZES and EES (10.8% vs. 11.6, p = 0.65), despite fewer target lesion revascularizations in patients with EES (2.6% vs. 4.9%, p = 0.03). The patient-oriented composite endpoint was similar (16.4% vs. 17.1%, p = 0.75). Two-year rates of definite or probable stent thrombosis were 1.2% and 1.4%, respectively (p = 0.63). Very late definite or probable stent thrombosis occurred only in 2 patients in each study arm (0.3% vs. 0.3%, p = 1.00). Conclusions After 2 years of follow-up and stringent discontinuation of DAPT beyond 12 months, Resolute ZES and Xience V EES showed similar results in terms of safety and efficacy for treating patients with a majority of complex lesions and off-label indications for drug-eluting stents. (The Real-World Endeavor Resolute Versus Xience V Drug-Eluting Stent Study in Twent
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