The Renaissance of Isothermal Titration Calorimetry

This dissertation is a composite of some of the research that I have conducted during the course of my PhD study. The larger goal of this dissertation is to renew the interests among the scientific community for an otherwise under-appreciated technique called Isothermal Titration Calorimetry. The resurgence of calorimetry in the biophysical community and the shift to investigations of more complex biological systems signal a real need for more sophisticated analysis techniques. This dissertation expounds on new ITC analysis methods that we have developed as well as results from the study of thermodynamic properties of higher order DNA structures. In 1978, Peter Privalov described the first use of microcalorimetry to obtain the thermodynamic properties for removing calcium from parvalbumin III protein. Fast forward 36 years: modern day electronics, highly efficient thermally conductive and chemically inert materials, in conjunction with sensitive thermal detectors, has transformed the original calorimeter into a device capable of measuring heat changes as small as 0.05 nanowatts, which is equivalent to capturing heat from an incandescent light bulb a kilometer away. However, analytical methods have not kept pace with this technology. Commercial ITC instruments are typically supplied with software that only includes a number of simple interaction models. As a result, the lack of analysis tools for more complex models has become a limiting factor for many researchers. We have recently developed new ITC fitting algorithms that we have incorporated into a userriendly program (CHASM©) for the analysis of complex ITC equilibria. In a little over a year, CHASM© has been downloaded by over 370 unique users. Several chapters in this dissertation demonstrate this software’s power and versatility in the thermodynamic investigations of two model systems in both aqueous and non-aqueous media. In chapter VI, we assembled a model NHE-III1 : a novel structure of Gquadruplex in a double stranded form and studied its structural complexity and binding interactions with a classical G-quaduplex interactive ligand known as TMPyP4. In chapter VII, we reported the thermodynamic properties of a novel PAH system in which weak dispersion forces are solely responsible for formation of the supramolecular complexes

Vietnam’s Quest for Influence and Its Implications for the Management of Border Disputes with Laos and Cambodia

Through providing a historical overview of border disputes between Vietnam and neighbouring Laos and Cambodia in Indochina, the article aims to evaluate the success gained by Vietnam in its efforts to secure the western and southwestern land border and thus maintain a peaceful external environment for the domestic reform. Since the Cambodian endgame, Vietnam has sought to improve political relations with all neighbours (including China) and, on that basis, consistently applied fundamental principles of international law while adopting the region’s common practice in order to resolve border issues. In return, the Communist leadership in Laos and the Hun Sen regime in Cambodia have been eager to sustain the Cold War border treaty system with Vietnam in order to stabilize the border, address cross-border non-traditional security issues, and ensure Vietnam’s assistance for economic development and regime security. In addition, Vietnam’s border disputes with Cambodia prove harder to deal with because the latter’s domestic power struggle has turned the issue into a political card played by opposition parties in their election campaigns.Der Artikel untersucht die Grenzfragen in Festlandsüdostasien aus der Perspektive Vietnams, das versucht, die westliche und südwestliche Grenze nach Kambodscha und Laos zu sichern, um dadurch Freiräume für innenpolitische Reformen zu erhalten. Vietnam versucht die Beziehungen mit seinen Nachbarn zu verbessern. Die Nachbarstaaten verfolgen hierbei das Interesse, die Grenzen des Kalten Krieges aufrecht zu erhalten, um nichttraditionelle Sicherheitsbeziehungen lösen zu können und Vietnams Hilfe für den wirtschaftlichen Aufbau und den Regimeerhalt sichern zu können. Außerdem sind die Grenzstreitigkeiten mit Kambodscha schwieriger zu lösen, da die innenpolitischen Machtkämpfe in Kambodscha dazu führen, dass die Grenzfrage bei Wahlkämpfen politisiert wird

Global Market Shocks and Poverty in Vietnam: The Case of Rice

World food prices have experienced dramatic increases in recent years. These "shocks" affect food importers and exporters alike. Vietnam is a major exporter of rice, and rice is also a key item in domestic production, employment and consumption. Accordingly, rice price shocks from the world market have general equilibrium impacts and as such, their implications for household welfare are not known ex ante. In this paper we first present a simple framework for understanding the direct and indirect welfare effects of a global market shock of this kind. Second, we quantify the transmission of the price shock from global indicator prices to domestic markets. Third, we then we use an applied general equilibrium (AGE) model to simulate the effects of domestic price changes in more detail. Fourth, a recursive mapping to a large nationally representative living standards survey permits us to identify in detail the ceteris paribus effects of the shock on household incomes and welfare. In this analysis, interregional and intersectoral adjustments in the labor market emerge as key channels transmitting the effects of global price shocks across sectors and among households.

FDI spill-overs, absorptive capacity and domestic firms' technical efficiency in Vietnamese wearing apparel industry

This study empirically examines relationship between FDI spill-overs and technical efficiency of domestic firms and role of the absorptive capacity of domestic firms. Data on Vietnamese Annual Enterprises Survey are exploited to build a firm-level panel data on the Vietnamese wearing apparel industry from 2009 to 2013. By applying stochastic production frontier model, this paper shows that there are positive vertical spill-over effects but no horizontal effects. Moreover, this study finds the negative impact of the absorptive capacity of domestic firms on benefits reaped from FDI externalities

EfficientRec an unlimited user-item scale recommendation system based on clustering and users interaction embedding profile

Recommendation systems are highly interested in technology companies nowadays. The businesses are constantly growing users and products, causing the number of users and items to continuously increase over time, to very large numbers. Traditional recommendation algorithms with complexity dependent on the number of users and items make them difficult to adapt to the industrial environment. In this paper, we introduce a new method applying graph neural networks with a contrastive learning framework in extracting user preferences. We incorporate a soft clustering architecture that significantly reduces the computational cost of the inference process. Experiments show that the model is able to learn user preferences with low computational cost in both training and prediction phases. At the same time, the model gives a very good accuracy. We call this architecture EfficientRec with the implication of model compactness and the ability to scale to unlimited users and products.Comment: Published in 14th Asian Conference on Intelligent Information and Database Systems (ACIIDS), 202

Prevalence and impact of myocardial injury among patients hospitalized with COVID-19

BackgroundMyocardial injury is a prevalent complication observed in patients hospitalized with COVID-19 and is strongly associated with severe illness and in-hospital mortality. However, the long-term consequences of myocardial injury on clinical outcomes remain poorly understood. This study aimed to assess the impact of myocardial injury on both acute-phase and long-term prognosis in COVID-19 patients.MethodsA retrospective, observational study was conducted on all patients who received treatment at the Intensive Care Center for COVID-19 patient, University Medical Center Ho Chi Minh City (UCICC), from August 3rd, 2021, to October 28th, 2021.ResultsA total of 582 patients were enrolled in the study, of which 55.3% were female. The mean age of participants was 63.3 ± 16.2. Out of these patients, 330 cases (56.8%) showed myocardial injury. Compared to patients without myocardial injury, those with myocardial injury were older and had a higher incidence of chronic diseases including hypertension, ischemic heart disease, atrial fibrillation, heart failure, diabetes mellitus, chronic kidney disease. They also presented with more severe respiratory failure upon admission and showed a more pronounced abnormality in inflammation and kidney function tests. Furthermore, the in-hospital mortality rate was significantly higher in the group with myocardial injury (49.7% vs 14.3%, p < 0.001). After adjusting for age, gender, comorbidities, renal function, and disease severity at admission, myocardial injury emerged as an independent risk factor for in-hospital mortality (OR = 3.758, 95% CI 1.854–7.678, p < 0.001). Among successfully discharged COVID-19 patients, the all-cause mortality rate after a median follow-up of 18.4 months was 7.9%. Patients with myocardial injury had a significantly higher long-term mortality rate compared to those without myocardial injury (14.0% vs. 3.2%, p < 0.001). However, multivariable Cox regression analysis did not find myocardial injury to be a significant predictor of long-term mortality (HR = 2.128, 95% CI 0.792–5.712, p = 0.134).ConclusionsMyocardial injury is a common and serious complication in hospitalized COVID-19 patients, associated with increased in-hospital mortality. However, it does not significantly impact long-term mortality in successfully discharged COVID-19 patients

Effects of different feeds and stocking densities on growth and survival rates of mud crab (<em>Scylla paramamosain</em>) at the stage from megalopa to crablet-1

Mud crabs (Scylla genus) are luxury foods in high demand internationally. The efficient techniques for mud crab hatcheries are vital for providing breeds for their aquaculture, which is rapidly growing in many countries. This study aims to investigate the effects of different feeds and stocking densities on mud crabs' growth and survival rates (Scylla paramamosain) in the stage from megalopa to crablet-1 stage. Two separate experiments were conducted indoors in the 60-liter round plastic tanks (containing 50 liters of water at a 28‰ salinity). Experiment 1 investigated four feeds: frozen Artemia biomass, pureed shrimp meat, Lansy pellet feed (48% protein), and NRD pellet feed (55% protein). Megalopae (mean weight of 5.8 mg) were stocked at a density of 10/L. In experiment 2, the megalopae (mean weight of 5.4 mg) were stocked at densities of 20, 30, and 40/L and were fed the Lansy pellet feed, which was the best one selected from experiment 1. High survival rates were obtained at all four feeds (82.2–87.5%) and three stocking densities (88.4–90.1%). The growth performances in Lansy feed and frozen Artemia biomass were better than those in pureed shrimp meat and NRD pellet feed, which was seen through higher indicators of daily weight gain (DWG) and specific growth rate in weight (SGRw) (p p > 0.05). The investigated feeds and stocking densities suit the nursing mud crab (S. paramamosain) megalopa. In contrast, the Lansy pellet feeds had a stocking density of 20/L, resulting in the highest nursing efficiency

Current status and behavior modeling on household solid-waste separation: a case study in Da Nang city, Vietnam

This study focused on household solid-waste recycling in Da Nang city, Vietnam to assess the existing separation behavior and clarify the factors influencing the separation behavior. The authors conducted a questionnaire survey for 150 households in 6 urban districts, which consisted of household attributes, separation behavior, and the household's attitude on recycling and the environment. The waste separation rates were determined for leftover food and 13 recyclable items and the recyclable disposal habit was also assessed. The separation rate of leftover food was 77.3%. Among 13 surveyed recyclable items, plastic bottles and metal cans were two popular items with higher separation rate (72.5% and 63.8%, respectively). To identify the conscious structure and determinants of separation behavior, the authors developed a predictive model on the separation behavior of leftover food and recyclables by logistic and multiple linear regression analyses. The positive factors included behavior intention, sympathy for the collector, incentive brought by recycling, goal intention, internal norm, and perception of responsibility and seriousness. The negative factor was evaluation of trouble. The authors also analyzed the differences in separation rates among attributes. Based on the significant influence factors and attributes, the authors suggested how to promote separation behavior

Curie Temperature of Diluted Magnetic Semiconductors: the Influence of the Antiferromagnetic Exchange Interaction

The coherent potential approximation and mean field approximation are used to calculate the free energy of the coupled carrier – localized spin system in III-V diluted magnetic semiconductors. Thus the magnetic transition temperature Tc can be determined and its dependence on important model parameters. We show that the strong antiferromagnetic superexchange interaction between nearest neighbour sites considerably reduces the Curie temperature

Creating Fatigue Curve for Steel Machine Elements Using Fatigue Test Method with Gradually Increasing Stress Amplitude

In order to create a fatigue curve, the traditional fatigue test method is applied to specimens using a cyclic stress with constant amplitude. However, this method has disadvantages such as the experimental results could not be used because of specimens broken before reaching the expected stress amplitude, or the tests may be stopped before specimen broken because of limitation of time. To overcome this hurdle of the traditional method, a new experimental method using cyclic stress with gradually increasing amplitude was proposed to build the fatigue curve for steel machine elements