The Limits to Stability: The Economic Implications of the Paris Agreement on Vietnam, January 1973-August 1974.

The Paris Agreement of 27 January 1973 was intended, at least by some of its authors, to end the war and to bring peace to Vietnam and Indochina. Studies on the Agreement have generally focused on the American retreat from Vietnam and the military and political consequences leading to the fall of Saigon in April 1975. This study will seek to explore a number of questions which remain controversial. It addresses itself to considering whether under the circumstances prevailing between 1973 and 1974 the Paris Agreement could have worked. In the light of these circumstances it argues that the Agreement sought to establish a framework for future stability and economic development through multilateral aid and rehabilitation aimed at the eventual survival of South Vietnam. The main thrust of the study is the interraction between the US and the Asian protagonists, considered on their own terms. Special prominence is given to the role of Japan, who endeavoured to contribute, under the Agreement's auspices, the centre of gravity for the economic dimension. From the Indochina perspective the protagonists include the communist power centres of North Vietnam and Cambodia and the government of South Vietnam. The consequences of the accord for East Asia are also examined where it complemented new realities emerging there in the form of the Japan-China dialogue, the assumptions of US strategy and the diplomacy surrounding them. The attempt is made to identify through the day-to-day course of events the different stages in the evolution of the intended design. Especially close attention will be paid to certain periods to identify major turning points when the conjunction of events had a crucial bearing on the final outcome. Equal consideration is given to explain how and why the Paris Agreement lost all credibility and was no longer a possible framework for stability in Vietnam and Indochina

SU(3) Quantum Interferometry with single-photon input pulses

We develop a framework for solving the action of a three-channel passive optical interferometer on single-photon pulse inputs to each channel using SU(3) group-theoretic methods, which can be readily generalized to higher-order photon-coincidence experiments. We show that features of the coincidence plots vs relative time delays of photons yield information about permanents, immanants, and determinants of the interferometer SU(3) matrix

Development, Characterisation And Release Study Of Encapsulated Curcumin Microparticles.

Curcumin, the major yellow pigment of Curcuma longa L., has been traditionally used to treat inflammation, skin wounds and tumors. The major disadvantage of curcumin is its high colour intensity, which stains fabrics when in contact with the treated skin

Highly efficient influenza virus production: A MDCK-based high-cell-density process

Seasonal vaccination campaigns for influenza in developed and developing countries create a massive demand for 500 million (2015) vaccine doses every year [1]. Besides egg-based vaccine manufacturing, production platforms based on animal cell culture increasingly contribute to this overall growing market. In order to intensify cell culture-based influenza virus production, high-cell-density (HCD) cultivation of suspension cells can be applied to improve virus titer, process productivity and production costs [2]. For process optimization and evaluation of HCD conditions, cells cultivated using semi-perfusion approaches in small shakers can be used as a scale-down model for bioreactors operating in full perfusion mode [3]. In this study, a previously developed MDCK suspension cell line [4] was adapted to a new serum free medium [5] to facilitate higher growth rate, cell density and virus titer both in batch and in HCD. Therefore, MDCK cells cultivated in Smif-8 medium were slowly adapted to a new cultivation medium (Xeno™) by stepwise increasing the Xeno content. Fully adapted cells were cultivated in shaker flasks to evaluate the performance of influenza A virus production in batch and HCD. Cell densities exceeding 2∙107 cells/mL were achieved in shakers using semi-perfusion, where cell free medium was manually replaced with fresh medium. Volume and time interval of media replacement were chosen to achieve a constant cell-specific perfusion rate of 2.5 pL/(cell h). Cell cultures were infected with influenza virus (A/PR/8/34 H1N1 RKI) with trypsin addition. Cell count, viability, main metabolites and virus titer (HA-assay & TCID50) were monitored pre and post infection. Medium adaptation resulted in a MDCK suspension cell line with morphological, growth, and metabolic characteristics different from parental cells. Cells fully adapted to Xeno medium were growing to higher cell densities (1.4∙107 vs 6∙106 cells/mL) with higher specific growth rate (µmax: 0.036 vs 0.026 1/h), cells were bigger (15-16 vs 13-14 µm) and grew without aggregate formation. Due to higher cell densities at time of infection, virus titers up to 3.6 log10(HAU/100µL) were reached. In semi-perfusion, adapted MDCK cells were grown up to 6∙107 cells/mL, however, maximum virus titer and productivity were observed with 4∙107 cells/mL. In multiple harvests, very high virus titer exceeding 4 log10(HAU/100µL) and up to 9∙109 virions/mL (TCID50) were measured, which corresponded to an accumulated titer of 4.5 log10(HAU/100µL). Cell-specific virus titer was similar or higher compared to the reference batch infections, depending on perfusion and infection strategy. Overall, results in this semi-perfusion scale-down model for influenza A virus production suggest a highly efficient and productive upstream process for influenza virus production, with an up to six-fold improved space time yield compared to batch mode. [1] Palache A. et al., Vaccine 35 (2017): 4681–4686. doi: 10.1016/j.vaccine.2017.07.053 [2] Genzel Y. et al., Vaccine 32 (2014): 2770–2781. doi: 10.1016/j.vaccine.2014.02.016 [3] Vázquez-Ramírez D. et al., Vaccine (2018): article in press. doi: 10.1016/j.vaccine.2017.10.112 [4] Lohr V. et al., Vaccine 28 (2010): 6256–6264. doi: 10.1016/j.vaccine.2010.07.004 [5] Xeno™-S001S MDCK Cell Serum Free Medium (#FG0100402), Bioengine, Shanghai, Chin

Efficient influenza vaccine manufacturing: Single MDCK suspension cells in chemically defined medium

Facing the constant global high demand for influenza vaccines, improving production capacity is most important. For influenza vaccine production, cell culture-based processes have advantages regarding flexibility, efficiency, and safety in comparison with the traditional egg-based processes. To avoid problems related to microcarrier-based approaches and serum containing media, growth of suspension cells in chemically-defined media is favoured. In addition, such a process has advantages regarding the improvement of virus titers, the scale-up of the production process, and overall productivity in up- and downstream processing. In this study, a previously developed MDCK suspension cell line [1] was cultivated in an in-house chemically defined medium to evaluate cell growth and virus production. For the purpose of process intensification, virus adaptation and infection strategies were investigated to achieve high cell densities and to maximize virus titers. Therefore, an adapted influenza virus strain (A/PR/8/34 H1N1 RK1) was generated by a series of virus passages with low multiplicity of infection (MOI). Virus infections were carried out by supplementing 100% of fresh medium, infecting cells with a MOI of 10-3, and with trypsin addition at 72 h of cell cultivations in shake flasks and bioreactors. For scale-up, MDCK cells were cultivated in a DASGIP bioreactor system, optimizing stirring speed, time of infection, pH and DO levels both for cell growth and virus infection. Cell count, viability, main extracellular metabolites, and virus titers were measured to compare productivity between shake flasks and bioreactors. In batch culture (shake flasks and bioreactors), single MDCK cells were grown to maximum cell densities of 1.2 x107 cells/ml with cell viabilities exceeding 98% at high cell specific growth rates of 0.036 h-1. Virus adaptation to the MDCK suspension cell line led to a fast infection and stable virus titers over time. Regarding process optimization, optimal pH (cell growth: 7.00, infection: 7.20), DO (40%) and agitation speed (80 rpm) were chosen for influenza A virus production in three parallel bioreactors. Cell densities of 1.0 x107 cells/ml were achieved at time of infection (72 h) before performing a dilution step. Post infection, similar virus infection dynamics were observed in shake flasks and bioreactors. For both cultivation systems maximal HA titers of 3.6 log10(HAU/100µl) were achieved without reduction of cell-specific virus titer (12,000 virions/cell). Overall, a highly efficient and scalable upstream process was realized by cultivation of MDCK suspension cells as single cells in chemically defined medium. This is a strong basis for a promising application in large-scale influenza vaccine manufacturing and potential process intensification towards high cell density virus production. [1] Huang D. et al., PloS One 10 (2015): e0141686. doi: 10.1371/journal.pone.014168

Overcoming Status Quo Bias: Nudging in a Government-Led Digital Transformation Initiative

While Singaporean citizens are keen on using e-payments in retail shops, they still prefer cash payments in hawker centers and coffee shops, i.e., traditional open-air complexes selling inexpensive cooked food. A government-led initiative seeks to tackle the situation, known as status quo bias. The key actors involved in this initiative are public agencies, the central bank, and a private Singaporean electronic payment service provider. Working with these partners, we investigate the process designed to nudge citizens to use e-payments for micropayments in hawker centers and coffee shops. We employ a design ethnography methodology and adapt an existing nudging framework. Early findings reveal contingency factors that shape the nudging approach. Through this study, we expect to contribute to the theoretical development of nudging theory to overcome status quo bias in government-led digital transformation initiatives