Selection and identification of thermophilic yeast strains in leachate from the organic waste heap in Phu Luong district, Thai Nguyen province, Vietnam

The study was carried out to isolate and select useful thermophilic yeast strains in the process of organic domestic waste treatment in Phu Luong - Thai Nguyen. Research results from 23 samples of rust have isolated 10 strains of yeast on YPG medium at 40 oC. Among them, 6 strains of yeast were selected with the ability to grow and develop in a wide temperature range from 20-45 oC. The results of identification combined with morphological, physiological, and biochemical characteristics of yeast strains showed that, out of 6 selected strains, there were 3 strains belonging to the genus Saccharomyces (Saccharomyces sp. TNY13.01, Saccharomyces sp. TNY22.01), Saccharomyces cerevisiae TNY13.09), 2 strains of the genus Candida (Candida sp. TNY23.01, Candida tropicalis TNY23.126) and 1 strain of the genus Papiliotrema (Papiliotrema laurentii TNY23.127). Among them, the identified strain Saccharomyces cerevisiae TNY13.09 has the ability to grow at 45, tolerates a wide pH range of 4.0– 8.5, has a positive catalase reaction, is capable of using a variety of carbon sources, and belongs to class I biosafety group. On that basis, Saccharomyces cerevisiae TNY13.09 has the potential to be further researched and applied as additional microbial inoculants to the organic waste heap

EXTRACTION AND PROPERTY STUDIES OF COENZYME Q10 FROM RECOMBINANT AGROBACTERIUM TUMEFACIENS

In this report, some results of extraction and characterization of CoQ10 from recombinant A. tumefaciens are presented. Four different cell breaking methods (sonication, acidic treatment, ethanol treatment, and enzymatic lysis) in combination with the extracting steps were carried out to extract CoQ10 and the results showed that ethanol treatment was the most efficient method. Appropriate conditions for CoQ10 extraction were 25 oC, 24 hours incubation and ethanol solvent/biomass ratio of 10:1 (ml/g). Characterization of extracted CoQ10 showed that CoQ10 was sensitive to light, but stable in the temperature ranges of 4 – 60 oC and the pH range of 6.0 – 9.0. Obtained results in present study should be applied in the large scale for CoQ10 extraction, providing the CoQ10 product for testing production of functional foods

Emotional Regulation in Synchronous Online Collaborative Learning: A Facial Expression Recognition Study

Emotional regulation in learning has been recognised as a critical factor for collaborative learning success. However, the “unobservable” processes of emotion and motivation at the core of learning regulation have challenged the methodological progress to examine and support learners’ regulation. Artificial intelligence (AI) and learning analytics have recently brought novel opportunities for investigating the learning processes. This multidisciplinary study proposes a novel fine-grained approach to provide empirical evidence on the application of these advanced technologies in assessing emotional regulation in synchronous computer-support collaborative learning (CSCL). The study involved eighteen university students (N=18) working collaboratively in groups of three. The process mining analysis was adopted to explore the patterns of emotional regulation in synchronous CSCL, while AI facial expression recognition was used for examining learners’ associated emotions and emotional synchrony in regulatory activities. Our findings establish a foundation for further design of human-centred AI-enhanced support for collaborative learning regulation

Revealing the Hidden Structure of Affective States During Emotion Regulation in Synchronous Online Collaborative Learning

This study aims to explore the use of advanced technologies such as artificial intelligence (AI) to reveal learners' emotion regulation. In particular, this study attempts to discover the hidden structure of affective states associated with facial expression during challenges, interactions, and strategies for emotion regulation in the context of synchronous online collaborative learning. The participants consist of 18 higher education students (N=18) who collaboratively worked in groups. The Hidden Markov Model (HMM) results indicated interesting transition patterns of latent state of emotion and provided insights into how learners engage in the emotion regulation process. This study demonstrates a new opportunity for theoretical and methodology advancement in the exploration of AI in researching socially shared regulation in collaborative learning

NONLINEAR CHARACTERISTICS OF SQUARE SOLID-CORE PHOTONIC CRYSTAL FIBERS WITH VARIOUS LATTICE PARAMETERS IN THE CLADDING

Nonlinear characteristics of fused silica, solid-core photonic crystal fibers (PCFs) with a square array of air holes are studied numerically. We present a novel design that emphasizes the difference in air hole diameters in the photonic cladding. These PCFs have the advantages of flat dispersion, high nonlinearity, and low attenuation. Based on simulation results, three optimal structures, denoted #F1, #F2, and #F3, having anomalous and all-normal dispersions in the near-infrared range are selected to investigate characteristic properties at the pump wavelength. Such PCFs open up many possibilities for nonlinear optical applications, especially supercontinuum generation

INFLUENCE OF STRUCTURAL PARAMETERS ON OPTICAL CHARACTERISTICS OF PHOTONIC CRYSTAL FIBERS WITH CIRCULAR LATTICE

We demonstrate in this study that near-zero, ultra-flattened chromatic dispersion can be achieved over a wide range of wavelengths in photonic crystal fibers (PCFs) by means of slight variations in the geometrical parameters of the cladding. To do that, a new solid-core circular PCF design with various air hole diameters and lattice constants is presented, and the design features are numerically analyzed in detail. After 40 simulations, we determined three structures that possess optimal dispersion with the following lattice constants (Ʌ) and filling factors for the first ring (d1/Ʌ): Ʌ = 0.8 µm, d1/Ʌ = 0.45 for #F1, Ʌ = 0.9 µm, d1/Ʌ = 0.45 for #F2, and Ʌ = 1.0 µm, d1/Ʌ = 0.45 for #F3. High nonlinearity and low attenuation are outstanding features of our model. With these advantages, the proposed fibers are targeted for smooth flat broadband supercontinuum generation for near-infrared applications

Investigating the Effect of Matrices and Densities on the Efficiency of HPGe Gamma Spectroscopy Using MCNP

When determining radioactivities in environmental samples using low-level gamma spectroscopy, in order to raise detection limit, voluminous samples are used. It takes in account for the self-absorption (self-attenuation) of gamma rays in samples. The self-absorption effect is small or large depend on the sample shapes, matrices and densities. In this paper, we investigated the effect of some regular matrices such as water, soil, epoxy resin on the detector efficiency. Some analytical formulas for the correction of matrix and densities for soil sample was established and applied to calculate some activities from standard sample of IAEA-375

Growth performance, meat quality, and blood characteristics of finisher crossbred pigs fed diets supplemented with different levels of green tea (Camellia sinensis) by-products.

peer reviewed[en] BACKGROUND AND AIM: Dietary supplementation with green tea by-product shows special effects on animal parameters. This study aimed to assess the effects of green tea by-products (GTBP) in the diet on some blood parameters, growth performance, and carcass characteristics of finishing pigs and on meat quality, and nutritional composition of pork. MATERIALS AND METHODS: One hundred and sixty crossbred pigs with an initial body weight of 65.15 ± 0.38 kg, were distributed into four dietary treatments, with four replicates of 10 pigs each. The dietary treatments were a basal diet (control diet, CON), and three experimental diets (GTBP8, GTBP16, and GTBP24) based on the CON diet supplemented with GTBP at 8, 16, and 24 g/kg of feed. The studied parameters were examined during the experimental period of 10 weeks. RESULTS: No statistical differences in average daily feed intake, average daily gain, and feed conversion ratio were observed between the diet treatments (p > 0.05). Backfat thickness decreased (linear, p 0.05). However, pigs fed with GTBP had a decrease in cholesterol content and an increase in crude protein and total omega-3 content of pork compared to the CON diet (p < 0.05). Moreover, dietary supplementation with GTBP significantly decreased plasma cholesterol (p < 0.05), and trends for the decrease in low-density lipoprotein cholesterol and urea nitrogen were observed (linear, p = 0.08). CONCLUSION: Up to 24 g/kg GTBP in the diet for finishing pigs does not impair animal performance and makes carcass leaner with softer meat as well as positive effects on cholesterol and fatty acid metabolism. Further experiments are needed to determine the optimal levels of GTBP addition in finishing pig diet to produce higher meat quality

Fragmented understanding: exploring the practice and meaning of informed consent in clinical trials in Ho Chi Minh City, Vietnam

Background The informed consent process in clinical trials has been extensively studied to inform the development processes which protect research participants and encourage their autonomy. However, ensuring a meaningful informed consent process is still of great concern in many research settings due to its complexity in practice and interwined socio-cultural factors. Objectives This study explored the practices and meaning of the informed consent process in two clinial trials conducted by Oxford University Clinical Research Unit in collaboration with the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam. Methods We used multiple data collection methods including direct observervations, in-depth interviews with study physicians and trial participants, review of informed consent documents from 2009 to 2018, and participant observation with patients’ family members. We recruited seven physicians and twenty-five trial participants into the study, of whom five physicians and thirteen trial participants completed in-depth interviews, and we held twenty-two direct observation sessions. Results We use the concept “fragmented understanding” to describe the nuances of understanding about the consent process and unpack underlying reasons for differing understandings. Conclusions Our findings show how practices of informed consent and different understanding of the trial information are shaped by trial participants’ characteristics and the socio-cultural context in which the trials take place

Viral Metagenomic Analysis of Cerebrospinal Fluid from Patients with Acute Central Nervous System Infections of Unknown Origin, Vietnam.

Central nervous system (CNS) infection is a serious neurologic condition, although the etiology remains unknown in >50% of patients. We used metagenomic next-generation sequencing to detect viruses in 204 cerebrospinal fluid (CSF) samples from patients with acute CNS infection who were enrolled from Vietnam hospitals during 2012-2016. We detected 8 viral species in 107/204 (52.4%) of CSF samples. After virus-specific PCR confirmation, the detection rate was lowered to 30/204 (14.7%). Enteroviruses were the most common viruses detected (n = 23), followed by hepatitis B virus (3), HIV (2), molluscum contagiosum virus (1), and gemycircularvirus (1). Analysis of enterovirus sequences revealed the predominance of echovirus 30 (9). Phylogenetically, the echovirus 30 strains belonged to genogroup V and VIIb. Our results expanded knowledge about the clinical burden of enterovirus in Vietnam and underscore the challenges of identifying a plausible viral pathogen in CSF of patients with CNS infections