Faut-il corriger les rentabilités des hedge funds?

Ce papier examine deux principaux mécanismes proposés dans la littérature pour corriger les rentabilités lissées des hedge funds et l'impact de cette correction sur les caractéristiques statistiques de la distribution des rentabilités et sur la performance des fonds. Nos résultats suggèrent que le délissage a pour conséquence de modifier considérablement la distribution des rentabilités - augmenter l'écart-type, augementer ou baisser la skewness et la kurtosis. En revanche, la moyenne reste inchangée. Ce résultat indique une modification non négligeable du profil derisque des fonds suite au délissage. Concernant la performance des fonds mesurée par le ratio de Sharpe et l'indice Omega, nous trouvons que leur classement par rapport aux indices de marché reste plus ou moins inchangé. Malgré une corrélation assez forte entre les classements d'avant et d'après le délissage, des modifications de rang assez nettes ont été observées au sein des stratégies des hedge funds. Par ailleurs, le choix de la méthode de délissage a un impact non négligeable sur les résultats obtenus.hedge funds, mesures de performance, ratio de Sharpe,indice Omega, rentabilités lissées

Factor substitution in rice production function: the case of Vietnam

Vietnamese rice production has achieved remarkable success over the last couple of decades. This is due to land and market reforms, known as ‘Doi Moi’. There were noticeable changes in policies, such as land and production systems, which were transformed from a collective to an individual contract system in the 1980s. Vietnam made progress in rice production through the legalisation of the privatisation of farm properties and a huge investment in irrigation systems. The country not only ensured its domestic demand, but also started exporting rice and gradually became the second largest exporter in the world. An estimate of the Constant Elasticity of Substitution function (CES) for Vietnam’s rice production is essential for the government to design effective policy on agricultural production. This study makes the first attempt to estimate the nested CES model for Vietnamese rice production in 2012. The paper finds that the elasticity of substitution of Vietnam’s nested CES model lies between 0.44 and 0.46. The results indicate the weak substitutability between land and the capital-labour composite in the nested CES model. This also suggests that it is impossible to take labour as the substitutable factor for land and capital

Explaining the Organizational Commitment of Banking Employees

This study aims to demonstrate the factors influencing the organizational commitment of banking employees. The study surveyed 232 employees working in the commercial banking system in Vietnam. By combining qualitative and quantitative research methods, the study has shown that employees’ commitment to the organization is influenced by 8 factors, including the work environment, corporate culture, organizational support, job nature, training and development, income and benefits, peer relationships, and leadership style. Among these factors, leadership style is the most significant factor affecting employees’ commitment to the organization. The research results contribute to providing insights for managers to enhance the employees’ commitment to the organization in the banking sector

Differentiation Effect of Two Alkaloid Fractions from Vietnamese Lycopodiaceae on Mouse Neural Stem Cells

Various Lycopodium alkaloids have been studied for their various biological activities including anti-inflammatory, antioxidant, immunomodulatory, and neuroprotective activities. Moreover, these alkaloid compounds have high potential in the treatment of neuron degenerative disease. This study has been carried out to test the effect of Huperzia serrata (Thunb.) Trevis, and Lycopodium clavatum L alkaloid fractions on the mouse neural stem cells (NSCs). Firstly, the alkaloid fractions were used to verify its toxicity on NSCs. The multiple concentrations of alkaloid fractions from H. serrata (0.044; 0.088; 0.175; 0.35; 0.7; 1.4 mg/ml) and L. clavatum (0.031; 0.063; 0.125; 0.25; 0.50; 1.0; 2.0 mg/ml) have been used for the treatment of NSCs at period of 48h incubation. Results of the study suggested that the IC50 value of H. serrata and L. clavatum was 0.56 mg/ml and 0.50 mg/ml, respectively. Then, the NSCs were differentiated in the presence of 5 and 10 µg/ml of alkaloid fraction from H. serrata; 0.625 and 1.25 µg/ml of alkaloid fraction from L. clavatum for 6 days. Here, we observed the primary NSCs treated with alkaloid fraction extract from H. serrata showed the increased gene expression level of early neuron TUBB3 and neuron-specific cytoskeleton MAP2. On the other hand, the L. clavatum alkaloid fraction increased the expression of neural stem cell marker genes (Nestin and PAX6) and decreased neuron marker genes. In conclusion, these results established that alkaloid fraction from H. serrata promoted differentiation of the mouse NSCs to neuron cells, and L. clavatum extract had a capacity for stemness maintenance

Morphological Traits and Nuclear Genetic Diversity of Coptis sp. in Hoang Lien National Park, Lao Cai Province, Vietnam

Coptis is a medicinal plant genus in the Ranunculaceae family, and is also known as “Hoang Lien” in Vietnamese. It is a perennial herb that grows in some regions of the world. However, Coptis is endangered and faces global threats. This study aimed to characterize some main morphological characteristics and performed a phylogenetic analysis of 11 samples of Coptis sp. collected from Hoang Lien National Park using nuclear DNA sequence analyses. All sample species have unique morphological traits with distinct yellow rhizomes and basal leaves with five segments. The petiole measures 13-25 cm and is smooth, while the leaf blade is ovate, ranging from 7 to 15.5 cm in length and 5.5 to 14 cm in width. The leaves are subleathery, glabrous on the underside, and sparsely puberulous on the veins on the upper side. The molecular characterization of Coptis sp. genotypes was determined by ITS markers. The length of the ITS1-ITS2 sequences varied from 363 to 371 nucleotides. The average nucleotide composition was 17.11% A, 31.25% C, 32.247% G and 19.41% T, respectively. The comparison with the GenBank database showed that the samples had 95.71- 96.37% similarity with the species Coptis quinquesecta. The genetic distance among the 11 Coptis samples fluctuated from 0.00 to 0.017. A neighbor-joining tree was constructed to show the genetic relationships among Coptis samples. The results indicated that this endangered species had low levels of genetic diversity. The study has provided valuable information for genetic-based conservation of this rare endemic species and suggested some conservation strategies

How Digital Natives Learn and Thrive in the Digital Age: Evidence from an Emerging Economy

As a generation of ‘digital natives,’ secondary students who were born from 2002 to 2010 have various approaches to acquiring digital knowledge. Digital literacy and resilience are crucial for them to navigate the digital world as much as the real world; however, these remain under-researched subjects, especially in developing countries. In Vietnam, the education system has put considerable effort into teaching students these skills to promote quality education as part of the United Nations-defined Sustainable Development Goal 4 (SDG4). This issue has proven especially salient amid the COVID−19 pandemic lockdowns, which had obliged most schools to switch to online forms of teaching. This study, which utilizes a dataset of 1061 Vietnamese students taken from the United Nations Educational, Scientific, and Cultural Organization (UNESCO)’s “Digital Kids Asia Pacific (DKAP)” project, employs Bayesian statistics to explore the relationship between the students’ background and their digital abilities. Results show that economic status and parents’ level of education are positively correlated with digital literacy. Students from urban schools have only a slightly higher level of digital literacy than their rural counterparts, suggesting that school location may not be a defining explanatory element in the variation of digital literacy and resilience among Vietnamese students. Students’ digital literacy and, especially resilience, also have associations with their gender. Moreover, as students are digitally literate, they are more likely to be digitally resilient. Following SDG4, i.e., Quality Education, it is advisable for schools, and especially parents, to seriously invest in creating a safe, educational environment to enhance digital literacy among students

Scaling up the use of low-emissions development (LED) research outputs in Vietnam: Co-design of LED research priorities, outputs, and impact pathways for emissions reduction from the livestock sector

Key messages – Using a rational formulation tool (PC Dairy Software) with locally available feeds can increase productivity and income of dairy farmers and reduce methane emissions. This requires building the capacity of policymakers, extension officers, dairy farmers, and feed industries to facilitate the use of the livestock PC Dairy Software and the national deed database. – Co-designing low-emissions development (LED) research priorities, outputs, and impact pathways with user input ensures relevant research and generates impact. This helps develop and refine research outputs, communication with stakeholders, and integration into LED policies and strategies. – Promoting improved feed by using the national feed database and PC Dairy Software can contribute to achieving Vietnam’s greenhouse gas (GHG) reduction targets set in the nationally determined contribution (NDC) and green growth strategy (GGS)

Unexpected cases in field diagnosis of African swine fever virus in Vietnam: The needs consideration when performing molecular diagnostic tests

Background: The first confirmed case of African swine fever (ASF) in Vietnam was reported officially in February 2019. To date, ASF virus (ASFV) have been detected in 63/63 provinces in Vietnam. Currently, real-time polymerase chain reaction (PCR) is considered to be a powerful tool for viral detection in field samples, including ASFV. However, some recent reports have suggested that mismatches in primer and probe binding regions may directly affect real-time PCR qualification, leading a false-negative result.Aim: This study aims to further examine a conflicting result obtained from two OIE recommended methods, conventional PCR and real-time PCR, for ASFV detection.Methods: Two ASF suspected pigs from different provinces in the north of Vietnam were selected for this study based on clinical signs and postmortem lesions. The different results obtained by OIE-recommended conventional PCR and real-time PCR were further analyzed by the Sanger sequencing method and virus isolation in combination with hemadsorption (HAD) test using porcine alveolar macrophages cells.Results: The results showed that when the primer sequence matched perfectly with the sequences of field isolates, a mutation in probe binding region was found, indicating that a single mismatch in the probe binding site may cause a false-negative result by real-time PCR in detecting ASFV in clinical samples in Vietnam. An agreement between conventional PCR, using PPA1/PPA2 primers and two golden standard methods, virus isolation in combination with HAD assay, and sequencing method was observed in this study.Conclusion: A single mismatch in the probe binding site caused a failse-negative result by realtime PCR method in field diagnosis of ASFV. The needs consideration when selecting the appropriate molecular diagnostic methods is based on the current databases of ASFV sequences,  particularly for epidemiological surveillance of ASF. Keywords: African swine fever, PCR, Pigs, Real-time PCR, Vietna

Brza serotipizacija virusa afričke kuge svinja zasnovana na analizi kratkih fragmenata EP402R gena koji kodira CD2-like protein

The first confirmed case of African swine fever (ASF) in Vietnam was officially reported in February 2019. To date, the ASF virus (ASFV) has been detected in all 63 cities/provinces in Vietnam. In order to get a better understanding of the potential role of the EP402R gene in a grouping of ASFV serotypes, thirty ASFV sequences of EP402R genes (accession numbers: MN711757-86) from North Central Coast of Vietnam and 68 well-known references of serotype groups from previous studies were further analyzed. Interestingly, we found that a short fragment of 90 nucleotides was very typical for 8 serological groups of ASFVs. A primer set was designed to amplicon the short fragment of 90 nucleotides using the Primer3 program to establish a simplified method for the serotyping of ASFV. Our results indicated that phylogenetic analysis of the short fragment (90 nucleotides) of the EP402R gene is a very specific and useful method for ASFV serotyping when compared to the previous method using a long fragment (816 nucleotides) of this gene and well-known serotype references based on haemadsorption inhibition (HAI) assay.Prvi potvrđen slučaj afričke kuge svinja (ASF) u Vijetnamu bio je zvanično prijavljen u februaru 2019. godine. Do danas, ASF virus (ASFV) je detektovan u 63 provincije Vijetnama. Radi boljeg razumevanja potencijalne uloge EP402R gena u grupisanju ASFV serotipova, analizirano je trideset ASFV sekvenci EP402R gena (pristupni brojevi: MN711757-86) poreklom iz Centralne severne obale Vijetnama i 68 referentnih uzoraka serotip grupa koji su dobro poznati iz prethodnih studija. Interesantan je bio nalaz da je kratak fragment od 90 nukleotida bio tipičan za 8 seroloških grupa ASF virusa. Dizajniran je set prajmera sa ciljem amplifi kacije kratkih fragmenata (90 nukleotida), korišćenjem Primer3 programa, a za uspostavljanje jednostavne metode serotipiziranja ASFV. Rezultati ukazuju da je fi logenetska analiza kratkih fragmenata (90 nukleotida) EP402R gena je veoma specifična i predstavlja korisnu metodu serotipizacije ASFV u poređenju sa prethodno opisanim metodama koje su koristile duge fragmente (816 nukleotida) ovog gena kao i dobro poznate referentne serotipove dobijene metodom inhibicije hemadsorbcije