182 research outputs found
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
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
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.
ARE CONSUMERS WILLING TO PAY MORE FOR TRACEABILITY? EVIDENCE FROM AN AUCTION EXPERIMENT OF VIETNAMESE PORK
This study aims to conduct the consumer’s willingness to pay (WTP) for traceable pork products by using the auction experiments methods, estimate the factors affecting to the WTP and identify the demand for specific information in traceability systems from information of consumers in Vietnam. The results indicated that, the WTP for traceable pork products of consumers is higher than 24%, comparing to the non-traceable pork products. The frequency of pork consumption, gender, age, education, health self-report and consumer’s attitude from risk of unsafe pork products were the influencing factors to the consumer’s WTP for traceable pork. The necessary information of traceability, suggested by consumers, included: information of additives included in the purchased pork, place of origin, expiration date and quality certificate
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
OPTICAL BISTABILITY IN A DEGENERATE TWO-LEVEL EIT MEDIUM UNDER THE INFLUENCE OF AN EXTERNAL MAGNETIC FIELD: AN ANALYTICAL APPROACH
We investigate the behavior of optical bistability in a degenerate two-level atomic medium using an external magnetic field to separate the lower level into two distinct levels that both connect to an upper level by the probe and coupling laser fields. Based on analytical solutions, the absorption spectrum and behavior of optical bistability in an electromagnetically induced transparency regime under an external magnetic field are investigated. By controlling the external magnetic field, we find that the appearance and disappearance of the optical bistability can be easily controlled according to the strength of the magnetic field in the transparent window domain. Furthermore, the effects of the intensity of the coupling laser field and the parameters of the system on the behavior of optical bistability are also considered. The proposed model is useful for applications in all-optical switches and magneto-optic storage devices.We investigate the behavior of optical bistability in a degenerate two-level atomic medium using an external magnetic field to separate the lower level into two distinct levels that both connect to an upper level by the probe and coupling laser fields. Based on analytical solutions, the absorption spectrum and behavior of optical bistability in an electromagnetically induced transparency regime under an external magnetic field are investigated. By controlling the external magnetic field, we find that the appearance and disappearance of the optical bistability can be easily controlled according to the strength of the magnetic field in the transparent window domain. Furthermore, the effects of the intensity of the coupling laser field and the parameters of the system on the behavior of optical bistability are also considered. The proposed model is useful for applications in all-optical switches and magneto-optic storage devices
Assessing Vegetation Cover Change Using Remote Sensing: Case Study at Binh Duong Province, Vietnam
This study aims to present the application of remote sensing in monitoring vegetation change in Binh Duong Province, Vietnam. The study used Landsat 5 images in the year 2010 and Landsat 8 images in the years 2015 and 2020 to investigate the area of vegetation. The maximum likelihood classification method (MLC) was used to classify land cover and an accuracy matrix was computed to validate the classification results. The references data were collected to support classification and accuracy assessment processes including land use maps in 2010, 2015, and 2020. In addition, collected field points and UAV (unmanned aerial vehicle) in 2020 were used. The overall accuracies are 81.27%, 84.41%, and 83.86%, and Kappa indices were 0.76, 0.80, and 0.80, corresponding to 2010, 2015, and 2020. The results showed that as compared to 2010 and 2015, the area of vegetation in 2020 decreased 10% and 8%, respectively. The average vegetation cover per capita was 740 m2 person-1 in 2020, compared to 1000 m2 person-1 in 2015 and 1200 m2 person-1 in 2010. This reduction was obvious in urban areas in the province, due to the need for construction and development. The study provides meaningful information on vegetation change and green area per capita in Binh Duong Province from 2010 to 2020
The Vatly Radio Telescope: Performance Study
A detailed account of the performance of the VATLY radio telescope, operated in HaNoi on and near the 21 cm HI line, is given. Drift scans across the Sun are used to measure the dependence of the gain on frequency and power, revealing small nonlinearities at or below the percent level. Interferences associated with the electromagnetic pollution in the Ha Noi environment are described. The sensitivity of the instrument is discussed and demonstrated with the detection of the Crab. The reliability of the measurement of the spectral flux density is illustrated by comparing solar flux data measured in Ha Noi and at the Australian observatory of Learmonth
Simultaneously induced mutations in eIF4E genes by CRISPR/Cas9 enhance PVY resistance in tobacco
Tobacco is an important commercial crop and a rich source of alkaloids for pharmaceutical and agricultural applications. However, its yield can be reduced by up to 70% due to virus infections, especially by a potyvirus Potato virus Y (PVY). The replication of PVY relies on host factors, and eukaryotic translation initiation factor 4Es (eIF4Es) have already been identified as recessive resistance genes against potyviruses in many plant species. To investigate the molecular basis of PVY resistance in the widely cultivated allotetraploid tobacco variety K326, we developed a dual guide RNA CRISPR/Cas9 system for combinatorial gene editing of two clades, eIF4E1 (eIF4E1-S and eIF4E1-T) and eIF4E2 (eIF4E2-S and eIF4E2-T) in the eIF4E gene family comprising six members in tobacco. We screened for CRISPR/Cas9-induced mutations by heteroduplex analysis and Sanger sequencing, and monitored PVY(O) accumulation in virus challenged regenerated plants by DAS-ELISA both in T0 and T1 generations. We found that all T0 lines carrying targeted mutations in the eIF4E1-S gene displayed enhanced resistance to PVY(O) confirming previous reports. More importantly, our combinatorial approach revealed that eIF4E1-S is necessary but not sufficient for complete PVY resistance. Only the quadruple mutants harboring loss-of-function mutations in eIF4E1-S, eIF4E1-T, eIF4E2-S and eIF4E2-T showed heritable high-level resistance to PVY(O) in tobacco. Our work highlights the importance of understanding host factor redundancy in virus replication and provides a roadmap to generate virus resistance by combinatorial CRISPR/Cas9-mediated editing in non-model crop plants with complex genomes
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