412 research outputs found

    Airborne transmission of pathogens emerging in the poultry industry

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    Poultry houses might have high levels of airborne pathogens, including Escherichia coli (E. coli) and avian influenza (AI), which may be transmitted through the air and pose risks of infection. The objective of the dissertation is to provide an insightful understanding the of airborne transmission of E. coli and AI which were attached to poultry dust particles. Chapter I and VI summarized background, gap in knowledge, and discussed the limitations and implications of the study. Chapter II compared the efficiency of Andersen six-stage impactor, all-glass impinger, and ACD-200 Bobcat, in collecting airborne E. coli carried by dust particles. The results showed that the Andersen six-stage impactor and the all-glass impinger outperformed the Bobcat sampler. Airborne E. coli were found to mainly aggregate on large particles (\u3e7.0 µm). The survivability of E. coli in poultry litter under different environmental conditions was described in Chapter III. The survivability of airborne E. coli was found to have a half-life time of 5.7 ± 1.2 min, while the survivability of settled E. coli and E. coli in poultry litter were much longer with half-life times of 9.6 ± 1.6 hrs and 15.9 ± 1.3 hrs, respectively. The effect of ultraviolet (UV) light on the inactivation of airborne E. coli carried by poultry dust particles under laboratory conditions was explored in Chapter IV. The inactivation rates varied from over 99.87% and 99.95% at 5.62 s of contact time to 72.90% and 86.60% at 0.23 s of contact time, with 1,707 µW cm−2 and 3,422 µW cm−2 of UV irradiance, respectively. Utilizing computational modeling to assess the risk of airborne and deposited AI carried by poultry-litter dust particles was investigated in Chapter V. Results showed that concentrations of airborne AI transmitted to other farms in a day were lower than the minimal infective dose for poultry. The study suggests that factors such as infected location and type of poultry house may influence the risk of airborne transmission of HPAI. In conclusion, this dissertation explores sampling methods, survivability, mitigation technologies for airborne transmission of pathogens in poultry, and factors affecting infection probabilities in the poultry industry

    Labour Commitments in the EVFTA: Amendments and Supplements to Vietnamese Law and Recommendations

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    Following months of negotiations, Vietnam and the European Union (EU) signed the EU-Vietnam free trade agreement (EVFTA) on June 30, 2019 (effective from August 1, 2020). Although this agreement opens up enormous opportunities for cooperation with the EU in many trade areas, Vietnam would still ensure compliance with other non-trade provisions, particularly with the labour clauses in this agreement, in accordance with the principle pacta sunt servanda, which is a fundamental principle of international law. By using a synthesis research method, comprehensive assessment, and in-depth comparison with documents of the International Labour Organization (ILO), EVFTA regulations, and Vietnamese legal documents on labour, this study aims to review the amendments and modifications of Vietnam’s labour law to fulfil the commitments in labour in the EVFTA, as well as provide recommendations on how to enhance the Vietnamese labour law to ensure effective implementation of these international labour responsibilities. Keywords: EVFTA, EU, labour, commitment. DOI: 10.7176/JLPG/125-10 Publication date:October 31st 2022

    Asymmetric Impacts of Public Debt on Economic Growth: Empirical Evidence From Vietnam

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    Purpose: The objective studies the influence of government debt on the expansion of the Vietnamese economy was the subject of the research presented in this article.   Theoretical framework: Most governments in developing nations have budget deficits due to excessive spending and inadequate revenue. When the government chooses to pay the budget deficit through borrowing, it incurs a liability known as public debt and public debt on economic growth.   Design/methodology/approach: In regression analysis involving time series data, if the regression model contains the variables' present values and the lagged values (past values), this model is known as the lagged distribution model. If the model's explanatory variables include one or more lagged values of the dependent variable, the model is called the autoregressive model. Nonlinear Auto Regressive Distributed Lag regression was applied.   Findings: The findings reveal that government debt has a considerable and disproportionate effect on sustained economic growth in the short and long run using a Nonlinear Autoregressive Distributed Lag (NARDL) model with quarterly data over twenty years beginning in 2000.   Research, Practical & Social implications: The results indicate a disproportional association between public sector debt levels and short- and long-term economic growth. The results are consistent with recent empirical studies showing a nonlinear relationship between some nations' public debt and economic development.   Originality/value: Government debt should support short- and long-term economic growth through funding production. Consequently, government debt should not burden the economy when the high amount of debt exceeds the capacity to repay

    On quantum melting of superfluid vortex crystals: from Lifshitz scalar to dual gravity

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    Despite a long history of studies of vortex crystals in rotating superfluids, their melting due to quantum fluctuations is poorly understood. Here we develop a fracton-elasticity duality to investigate a two-dimensional vortex lattice within the fast rotation regime, where the Lifshitz model of the collective Tkachenko mode serves as the leading-order low-energy effective theory. We incorporate topological defects and discuss several quantum melting scenarios triggered by their proliferation. Furthermore, we lay the groundwork for a dual non-linear gravity description of the superfluid vortex crystals.Comment: comments are welcom

    Robust newsvendor games with ambiguity in demand distributions

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    In classical newsvendor games, vendors collaborate to serve their aggregate demand whose joint distribution is assumed known with certainty. We investigate a new class of newsvendor games with ambiguity in the joint demand distributions, which is represented by a Fréchet class of distributions with some, possibly overlapping, marginal information. To model this new class of games, we use ideas from distributionally robust optimization to handle distributional ambiguity and study the robust newsvendor games. We provide conditions for the existence of core solutions of these games using the structural analysis of the worst-case joint demand distributions of the corresponding distributionally robust newsvendor optimization problem
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