58 research outputs found

    The Nonlinearity of Working Capital and Cross-Sectional Stock Returns: Does Financial Constraints Matter?

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    This study is the first to examine the impacts of working capital (WC) and financial constraints on cross-sectional stock returns in Taiwan. The findings indicate a non-linear relationship between WC and stock returns. Moreover, the nonlinearity between WC and cross-sectional stock returns is robust after controlling for financial constraints, risk, and growth factors, before the Covid-19 pandemic. In contrast, there is no evidence of nonlinearity between WC and stock returns throughout the Covid-19 outbreak. In addition, the study shows that any deviations from the minimum WC level enhance the stock returns cross-sectionally. It is found that a positive Deviation effect exists in the Taiwan stock exchange before the Covid-19 pandemic by employing portfolio sorting methodologies. The return difference of the long buying highest Deviation and short selling lowest Deviation portfolios earn from 0.6% to 0.9% per month after controlling for financial constraints, risks, and growth factors. Interestingly, it is determined that the deviation effect becomes negative for small stocks during the Covid-19 pandemic, implying that investors prefer small stocks to maintain minimum working capital. The results support the trade-off theory and liquidity preference theory. Finally, the study provides insights into working capital management for managers, and investment strategies for investors during the pandemic

    Development of a diagnostic scar marker for Vibrio shilonii caused acute hepatopancreatic necrosis disease in whiteleg shrimp

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    Background: In a previous report, we showed that Vibrio shilonii was found on whiteleg shrimp (Litopenaeus vannamei) with acute hepatopancreatic necrosis disease in Thua Thien Hue province, Vietnam. This study was performed to develop a diagnostic molecular marker generated by random amplified polymorphic DNA (RAPD) for V. shilonii rapid detection.Methods: Pathogen Vibrio spp. were isolated from shrimps and fishes, and were identified by 16S rRNA sequencing. Genetic diversity of Vibrio strains was analysis by RAPD technique. Specific PCR product for V. shilonii was cloned and sequenced. SCAR marker was developed from specific PCR product.Result: Twenty random primers were evaluated for RAPD to identify DNA polymorphisms between Vibrio species. The random primer OPN-06 generated a 468-bp DNA fragment specific for V. shilonii. This was then converted into a sequence-characterized amplified region (SCAR) marker designated N6-441.Conclusion: Specific primers (Vshi-441F/Vshi-441R) amplified a unique DNA fragment in all V. shilonii isolates but not in the other Vibrio spp. This PCR assay showed significantly sensitive to the target DNA and reliably for the amplification the V. shilonii genome.Keywords: AHPND; RAPD; SCAR; Vibrio shilonii; Vietna

    Hydrogen production by newly isolated Clostridium species from cow rumen in pure- and co-cultures on a broad range of carbon sources

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    Three novel hydrogen-generating strains, ST1, ST4, and ST5, were isolated from the rumen of cow in Vietnam, and respectively identified as Clostridium beijerinckii ST1, Clostridium bifermentans ST4, and Clostridium butyricum ST5, based on 16S rDNA gene sequence analysis and physiobiochemical characteristics. The dark fermentative hydrogen production of these isolated Clostridium strains was performed and characterized in both pure- and co-cultures from various carbon sources including sucrose, glucose, lactose, xylose, molasses, cassava stumps, and rice distillers wet grains with soluble. The highest hydrogen production was achieved from a co-culture with three Clostridium strains. To optimize the operational conditions of temperature, time, and substrate concentration for the high-level production of hydrogen, response surface methodology in a Box-Behnken design was used. The results revealed a maximum hydrogen production of 1.13 ± 0.015 L H2/L medium by the three-strain co-culture under the following fermentation conditions: 11.63 g/L sucrose, 36.1 °C, in 51.13 h

    Investigation of salt-tolerant rhizosphere bacteria from seawater-intruding paddy rice field in Vietnam

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    Salt‐tolerant plant growth‐promoting rhizobacteria (ST‐PGPR) are known as potential tools to improve rice salinity tolerance. In this study, we aimed to investigate the plant growth‐promoting rhizobacteria community richness of the paddy rice fields in Soc Trang and Ben Tre Provinces where were seriously affected by sea level rise. The salinity in the sampling sites ranged from 0.14‰ to 2.17‰ in November 2018, the rainy season. The microbial abundance of samples was evaluated by spreading the samples in tryptic soy agar (TSA) medium supplemented with various concentrations of NaCl. With the increase of salt concentration up to 10% NaCl, a total number of bacteria decreased for all the samples, ranging from 106 to 104 CFU/g, and bacterial colonies were not observed at 30% NaCl. Among a total of 48 salt-resisting bacteria isolated from the rice paddy field mud surrounding the rice root, 22 isolates were able to produce indole-3-acetic acid (IAA: phytohormone for the plant growth). Seventeen out of 48 isolates were able to grow in the medium without nitrogen or phosphor sources. Six isolates having high IAA producing activity, nitrogen fixation and phosphate solubilization were belonged to Bacillus (DT6, LT16, and LHT8), Halobacillus (DT8), Aeromonas (LHT1), and Klebsiella (LHT7) genera. All the sequences of the strains DT6, DT8, LT16, LHT1, LHT7, and LHT8 were registered in the GeneBank with the accession numbers MK335670, MK335671, MK335672, MK335673, MK335674, and MK335675, respectively.

    Excess body weight and age associated with the carriage of fluoroquinolone and third-generation cephalosporin resistance genes in commensal Escherichia coli from a cohort of urban Vietnamese children.

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    PURPOSE: Antimicrobial-resistant bacterial infections in low- and middle-income countries (LMICs) are a well-established global health issue. We aimed to assess the prevalence of and epidemiological factors associated with the carriage of ciprofloxacin- and ceftriaxone-resistant Escherichia coli and associated resistance genes in a cohort of 498 healthy children residing in urban Vietnam. METHODOLOGY: We cultured rectal swabs onto MacConkey agar supplemented with resistant concentrations of ciprofloxacin and ceftriaxone. Additionally, we screened meta-E. coli populations by conventional PCR to detect plasmid-mediated quinolone resistance (PMQR)- and extended-spectrum β-lactamase (ESBL)-encoding genes. We measured the associations between phenotypic/genotypic resistance and demographic characteristics using logistic regression.Results/Key findings. Ciprofloxacin- and ceftriaxone-resistant E. coli were cultured from the faecal samples of 67.7 % (337/498) and 80.3 % (400/498) of children, respectively. The prevalence of any associated resistance marker in the individual samples was 86.7 % (432/498) for PMQR genes and 90.6 % (451/498) for β-lactamase genes. Overweight children were significantly more likely to carry qnr genes than children with lower weight-for-height z-scores [odds ratios (OR): 1.24; 95 % confidence interval (CI): 10.5-1.48 for each unit increase in weight for height; P=0.01]. Additionally, younger children were significantly more likely to carry ESBL CTX-M genes than older children (OR: 0.97, 95 % CI: 0.94-0.99 for each additional year, P=0.01). CONCLUSION: The carriage of genotypic and phenotypic antimicrobial resistance is highly prevalent among E. coli in healthy children in the community in Vietnam. Future investigations on the carriage of antimicrobial resistant organisms in LMICs should focus on the progression of carriage from birth and structure of the microbiome in obesity

    Improvement in neoantigen prediction via integration of RNA sequencing data for variant calling

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    IntroductionNeoantigen-based immunotherapy has emerged as a promising strategy for improving the life expectancy of cancer patients. This therapeutic approach heavily relies on accurate identification of cancer mutations using DNA sequencing (DNAseq) data. However, current workflows tend to provide a large number of neoantigen candidates, of which only a limited number elicit efficient and immunogenic T-cell responses suitable for downstream clinical evaluation. To overcome this limitation and increase the number of high-quality immunogenic neoantigens, we propose integrating RNA sequencing (RNAseq) data into the mutation identification step in the neoantigen prediction workflow.MethodsIn this study, we characterize the mutation profiles identified from DNAseq and/or RNAseq data in tumor tissues of 25 patients with colorectal cancer (CRC). Immunogenicity was then validated by ELISpot assay using long synthesis peptides (sLP).ResultsWe detected only 22.4% of variants shared between the two methods. In contrast, RNAseq-derived variants displayed unique features of affinity and immunogenicity. We further established that neoantigen candidates identified by RNAseq data significantly increased the number of highly immunogenic neoantigens (confirmed by ELISpot) that would otherwise be overlooked if relying solely on DNAseq data.DiscussionThis integrative approach holds great potential for improving the selection of neoantigens for personalized cancer immunotherapy, ultimately leading to enhanced treatment outcomes and improved survival rates for cancer patients

    Successful Psoriasis Treatment Using NB-UVB with Methotrexate: The Vietnamese Experience

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    AIM: To compare the effectiveness of narrowband ultraviolet B (NBUVB) and oral methotrexate (MTX) to oral MTX alone in Vietnamese psoriasis patients, from May 2016 to May 2018. METHODS: We conducted a non-randomized trial on 70 patients with plaque-type psoriasis of moderate to severe. Thirty-five patients apply NBUVB once/day in 5 days/week for 4 weeks plus oral MTX 7.5 mg/week and 35 patients oral MTX 7.5 mg/week and both two groups treatment for 3 months. The extent of the lesion was assessed by the Psoriasis Area and Severity Index (PASI). RESULTS: The proportion of decreasing PASI was comparable (68.49% in NBUVB and MTX versus 57.62% in MTX alone); p < 0.05. Inside, good 28.58%, moderate 68.57% and poor 2.85% in NBUVB and MTX better than good 2.85%, moderate 71.4% and poor 25.72% in MTX alone; p < 0.05. The recurrence rate after 24 months of the NBUVB and MTX group (42.9%) was lower than the MTX alone group (71.4%); p < 0.05. CONCLUSION: NBUVB and oral MTX have affected treatment with chronic plaque psoriasis better than oral MTX alone

    Awareness and preparedness of healthcare workers against the first wave of the COVID-19 pandemic: A cross-sectional survey across 57 countries.

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    BACKGROUND: Since the COVID-19 pandemic began, there have been concerns related to the preparedness of healthcare workers (HCWs). This study aimed to describe the level of awareness and preparedness of hospital HCWs at the time of the first wave. METHODS: This multinational, multicenter, cross-sectional survey was conducted among hospital HCWs from February to May 2020. We used a hierarchical logistic regression multivariate analysis to adjust the influence of variables based on awareness and preparedness. We then used association rule mining to identify relationships between HCW confidence in handling suspected COVID-19 patients and prior COVID-19 case-management training. RESULTS: We surveyed 24,653 HCWs from 371 hospitals across 57 countries and received 17,302 responses from 70.2% HCWs overall. The median COVID-19 preparedness score was 11.0 (interquartile range [IQR] = 6.0-14.0) and the median awareness score was 29.6 (IQR = 26.6-32.6). HCWs at COVID-19 designated facilities with previous outbreak experience, or HCWs who were trained for dealing with the SARS-CoV-2 outbreak, had significantly higher levels of preparedness and awareness (p<0.001). Association rule mining suggests that nurses and doctors who had a 'great-extent-of-confidence' in handling suspected COVID-19 patients had participated in COVID-19 training courses. Male participants (mean difference = 0.34; 95% CI = 0.22, 0.46; p<0.001) and nurses (mean difference = 0.67; 95% CI = 0.53, 0.81; p<0.001) had higher preparedness scores compared to women participants and doctors. INTERPRETATION: There was an unsurprising high level of awareness and preparedness among HCWs who participated in COVID-19 training courses. However, disparity existed along the lines of gender and type of HCW. It is unknown whether the difference in COVID-19 preparedness that we detected early in the pandemic may have translated into disproportionate SARS-CoV-2 burden of disease by gender or HCW type
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