Direct embryogenesis from anther culture of hot chilli Capsicum annuum L.

In Viet Nam, local varieties of chili have a distinctive aroma and pungency. However, the generation of pure lines from pollen culture in local hot chilli has been very limited reported. Therefore, this study was to relate flower bud size with microspore developmental stages and the culture media have concentration changed of growth regulator effects on the in vitro androgenesis. Flower buds were randomly collected and visually divided into three stage based on both petal and sepal size. Then anther was cultured on MS basal medium with different concentration of hormones NAA changed 0.1 - 0.7 mg/L and kinetin changed 1.0 - 3.0 mg/L, BA changed 0.5 - 1.5 mg/L. The results showed that bud flower have anthers are light violet in color, 2.5 mm long, consisted of anthers with 80 % uni-nucleate and 20 % bi-nucleate microspores were selected. In induction culture media, it was observed that MS medium with 2.0 mg/L Kinetin and 0.5 mg/L NAA gave higher embryo frequency. MS medium with 1 mg/L BA is the best medium for embryo germination and inducting shoots. And ½ MS medium for shoot elongation and rooting

Vietnamese Version of Cornell Scale for Depression in Dementia at an Outpatient Memory Clinic: A Reliability and Validity Study

Background: In Vietnam, there has been, currently, no standardized tool for depression assessment for people with dementia (PWD). Cornell Scale for Depression in Dementia (CSDD) is a widely studied and used scale for PWD worldwide. Objectives: The aim of this study was to standardize the Vietnamese version of the CSDD (V-CSDD) in depression assessment in PWD through reliability and validity examination. Methods: V-CSDD was rated in terms of reliability and validity with gold standard regarding "major depressive episode"and "major depressive-like episode"of DSM-5. Cronbach's α, ICC, exploratory factor analysis (EFA), and receiver operating characteristic analysis were performed. Results: V-CSDD was found to have a high internal consistency reliability (Cronbach's α = 0.80), inter-rater reliability at sound ranking (ICC = 0.89; 95% CI = 0.81-0.94), maximum cut-off mark of 13 (sensitivity = 70%, specificity = 92%), and EFA, which suggested that V-CSDD may comprise 5 factors. Conclusions: Results indicate the V-CSDD to be a reliable and valid assessment and to be beneficial in classifying and diagnosing depression in dementia outpatients in clinical contexts

Effect of natural auxin from portulaca grandiflora hook and Ipomoea batatas (L.) Poir on the formation adventitious roots in vitro of Plumbago zeylanica L.

Plumbago zeylanica L. is a traditional herbal that has been reported to treat on skin diseases. Furthermore, some researchers have found plumbagin extracted from roots of this species can prevent cancer cell development. In current study, stems of Plumbago zeylanica L. were cultured on MS medium with BA 1.0 mg/L and IAA (0.01-0.15 mg/L) or NAA (0.1-0.15 mg/L). After 8-week cultured, stems were transferred to MS medium with extracted from stems of Portulaca grandiflora Hook (2-10 ml/L) or extracted from stems of Ipomoea batatas (L.) Poir. The results showed that, the appropriate medium for shoot formation was in MS with BA and IAA 0.1 mg/L or NAA 0.1 mg/L. The adventitious roots in vitro were formatted in MS medium supplied with extracted from stems Portulaca grandiflora Hook or from stems of Ipomoea batatas (L.) Poir 6 ml/L. Simultaneously, after 8-week cultured, the adventitious roots were collected and plumbagin qualitative were analyzed with pure plumbagin of Sigma. As the results, plumbagin presents in adventitious roots cultured

Effect of plant growth regulators on growth and lipid accumulation of microalgal Haematococcus pluvialis Flotow in two-stage culture

Haematococcus pluvialis cells were cultured in aerated liquid Bold’s Basal medium in two-stage (initial stage during in 7 weeks for increased biomass growth and second stage during in 3 weeks for increased lipid accumulation) with different volumes 250 mL, 10 L, and 1,000 L. With a volume of 250 mL, the medium was supplied with benzyl adenine (BA), indole-3-acetic acid (IAA) or gibberellic acid (GA3) at concentration from 0.1 - 0.2 mg/L in initial stage and IAA or GA3 at concentration from 0.1 - 0.2 mg/L in second stage. After 10 weeks of culture, results showed that supplement of 0.1 mg/L BA in initial stage and 0.125 mg/L IAA in second stage increased cell density, and microalgal cells had green color with a spherical shape. On the contrary, supplement of 0.15 mg/L IAA in initial stage and 0.175 mg/L GA3 in second stage increased lipid accumulation, and microalgal cells had red color with a spherical shape. With a volume of 10 L, the medium was supplied with 0.1 mg/L BA in initial stage, and treated with separation or combination from 2 - 3 of these factors (nitrogen starvation, 0.5% NaCl, 4.98 mg/L FeSO4) were applied in second stage. The result showed that the cultures was treated with nitrogen starvation increased dry biomass and biofuel, but treated with 4.98 mg/L FeSO4 only increased biofuel. With a volume of 1,000 L, microalgal cells were cultured in BB liquid medium in initial stage, and treated with 4.98 mg/L FeSO4 increased fresh 78.67 mg/mL and dry biomass 2.05 mg/L and total lipid content 28.24 %/ DW

Shoots formation from gynosinesis Cucumis sativus l.

Haploid plants achieve through androgenesis or gynogenesis. In gynogenesis method, the ovary or ovule are used as explants induct haploid plants. Female flower one day before flowering of Cucumis sativus L. are collected. Cold pretreatment of ovaries at 4°C up to 24 hours and culture under dark conditions. Significantly enhanced callus induction response is compared with cultures under 4-week cultured on CBM medium supplemented with various concentration of TDZ 0.01-0.04 mg/L. After 4 weeks, ovaries are transferred to medium with kinetin 0.05 – 0.20 mg/L. Then, ovaries were transferred to medium supplemented with BA: IAA 3:1. Finally, green ovaries were transferred to BA 1.5 mg/L and GA3 1.5 mg/L. The results showed that ovary induction has best affected on CBM with TDZ 0.03 mg/L with 11 callus/sample. Ovaries developed on kinetin 0.1 mg/L with 7.4 callus/sample. Ovaries become green and had leaves and roots formation on BA: IAA (3 mg/L: 1 mg/L). 11 plantlets were harvested from ovary culture after 12-week culture on CBM supplemented with BA 1.5 mg/L and GA3 1.5 mg/L

Insiders, Outsiders and Performance of Vietnamese Firms

The consensus in the finance literature is that a large proportion of inside ownership (defined as greater than 5% share ownership by non-institutional holders, managerial holdings, founding family holdings, cross-shareholdings by affiliated firms and ownership by creditors) tends to be associated with more unsatisfactory performance (as measured by ROE or ROA) when compared to firms with lower inside ownership, all else equal. However, this need not be the case if insiders act as monitors of the firm and have the same interest in returns as outsiders.  Ownership structure and firm level financial performance have not been widely studied in Vietnam.  Using data from 729 listed firms in Vietnam for 2018, we test the hypothesis that greater insider ownership has a negative impact on firm performance. We found that Vietnam's insiders play a monitoring role, exercising their relative power to ensure the firm's profitable functioning. These findings are inconsistent with research on Japanese groupings, as well as other findings. The Vietnamese stock market does not appear to be negatively affected by insider influence; indeed, insiders appear to act as positive monitors.

INFLUENCE OF CULTIVATION OF CHLORELLA VULGARIS ON MICROORGANISMS IN SEAFOOD WASTEWATER

Microalgae cultivation in wastewater for many purposes has been investigated recently decade ago. In this study, Chlorella vulgaris was chosen to culture for examination of its influences on microorganisms of seafood wastewater in particular aerobic bacteria, Coliform and E. coli. The microalgae cultivation was realized in Erlenmeyer flasks containing seafood wastewater medium. Another was also grown in original medium called Sueoka medium for control. All experiments were set up until almost all Chlorella vulgaris decanted or flocculated in the bottom of flasks. The changes of bacteria counts including aerobic bacteria, Coliform and E. coli were measured to evaluate the impact of cultivation of Chlorella vulgaris on them in this sewage. Otherwise, the growth of microalgae has been also recorded for evaluating the effect of a new medium on metabolism of Chlorella vulgaris. The results showed that the bacteria counts were significantly reduced after day 3 of microalgae culture. These results have been calculated the efficiency of aerobic bacteria, Coliform and E. coli elimination out of wastewater medium represented approximately 70%, 81% and 90% respectively. These eliminations provided evidences of difficult metabolism of bacteria under the presence of microalgae as like as Chlorella vulgaris. In other words, the symbiosis of microalgae and bacteria in sewage could prevent the raising of bacteria counts

Two different mechanisms of ampicillin resistance operating in strains of Vibrio cholerae O1 independent of resistance genes.

Autoagglutinable strains of Vibrio cholerae O1 (seven nonfimbriate strains and one fimbriate strain) were transformed to obtain resistance to ampicillin. Two distinct mechanisms were found in these strains. One was operating in nonfimbriate strains by reducing OmpU protein production and the other was operating in a fimbriate strain (Bgd17) by newly overproducing cpxP protein. The twitching motility in the fimbriate Bgd17 strain disappeared depending on the production of cpxP protein, suggesting that fimbriation of V. cholerae O1 is controlled by a two-component signal transduction system

Long short-term memory (LSTM) neural networks for short-term water level prediction in Mekong river estuaries

This study firstly adopts a state-of-the-art deep learning approach based on a Long Short-Term Memory (LSTM) neural network for predicting the hourly water level of Mekong estuaries in Vietnam. The LSTM models were developed from around 8,760 hourly data points within 2018 and were evaluated using the Nash-Sutcliffe efficiency coefficient (NSE), mean absolute error (MAE), and root mean square error (RMSE). The results showed that the NSE values for the training and testing steps were both above 0.98, which can be regarded as very good performance. Furthermore, the RMSE were between 0.09 and 0.11 m for the training and between 0.10 and 0.12 m for the testing, while MAE for the training ranged from 0.07 to 0.08 m and varied from 0.08 to 0.10 m for the testing. The LSTM networks appear to enable high precision and robustness in water level time series prediction. The outcomes of this research have crucial implications in river water level predictions, especially from the viewpoint of employing deep learning algorithms