Some Methods for Evaluating Performance of Management Information System

Recently, several kinds of information systems are developed for purposes and needs of business and play an important role in business organizations and management operations. Management information system, or MIS for short, is a kind of information system. It is a key factor to facilitate and attain efficient decision-making in an organization. Its performance relates to many other information systems, for instance, DSS or decision support system, SIS or strategic information system, etc. Methods of testing statistical hypotheses concerning the performance of MIS are absolutely essential to support management activities and decision-making

The Intention to Participate in Voluntary Social Insurance of Informal Sector Workers: the Case in Mekong Delta, Vietnam

Purpose: The objective of this study is to develop the participation of informal sector workers in voluntary social insurance to ensure the Social Security policy of the Government of Vietnam.   Theoretical Framework: Based on the results compiled from expert as: Kotler, 2003; Schiffman and Kanuk, 2007; Ming-Chi Lee, 2009; Holmgren et al., 2016 and Krajaechun and Praditbatuga, 2019. The model was preliminarily designed by the author through eight prefix variables including: Confidence in Benefits, Evaluation of Social Responses, Perception of risks, Beliefs, Motivation, Attitude towards Voluntary social insurance, Subjective norms, and Intention to participate in Voluntary social insurance.   Methodology: This study employs primary data from a survey of 370 people working in informal workers in 04 province of the Mekong Delta region of Vietnam: Kien Giang Province, Tra Vinh Province, Hau Giang Province and Soc Trang Province. The Authors using Partial Least Squares-Structural Equation Modeling (PLS-SEM) and Bootstrap analysis in the SEM reliability test employed for data analysis and interpretation.   Findings: Research results show that two factors that affect the intention to participate in voluntary social insurance of workers in the informal sector: Attitude towards social insurance and subjective norms.   Solutions: From the research results, the authors have proposed solutions to further improve the participation in voluntary social insurance of workers in the informal sector in the Mekong Delta, Vietnam in future

Model of neutrino effective masses

It is shown that an effective (nonrenormalizable) coupling of lepton multiplets to scalar triplets in the 331 model with sterile/exotic neutrinos, can be a good way for generating neutrino masses of different types. The method is simple and avoids radiative/loop calculations which, sometimes, are long and complicated. Basing on some astrophysical arguments it is also stated that the scale of SU(3)L symmetry breaking is at TeV scale, in agreement with earlier investigations. Or equivalently, starting from this symmetry breaking scale we could have sterile/exotic neutrinos with mass of a few keV's which could be used to explain several astrophysical and cosmological puzzles, such as the dark matter, the fast motion of the observed pulsars, the re-ionization of the Universe, etc

TAXONOMIC IDENTITY OF ARISAEMA CONDAOENSE (ARACEAE) BASED ON NEW MORPHOLOGICAL AND MOLECULAR DATA

Arisaema condaoense V.D. Nguyen was described as a new species from Con Dao National Park, Ba Ria–Vung Tau Province, Vietnam in 2000. However, this species has been suspected of being a form of Arisaema roxburghii Kunth, a species widespread in the whole Indochina and Malay Peninsula. This was due to the original description based on dried specimens with male inflorescences only. Morphological characteristics of female inflorescences, which are of taxonomical importance to identify the species, have not been known. In June 2015, we re-sampled the plant in Con Dao National Park with both male and female inflorescences for detailed examination of morphological characteristics. Besides, the matK gene of the chloroplast genome of this species was sequenced to analyse its phylogenetic relationship with other Arisaema species. The gathered morphological and molecular data indicate that A. condaoense is certainly a distinct species, not a synonym of A. roxburghii. The noted morphological characteristics also provide key differences to distinguish A. condaoense from two other morphologically close species of sect. Fimbriata (i.e A. maxwellii from Thailand and A. pierreanum from Vietnam which also share yellow spathes and several other characteristics in common), which are supported by the molecular data. Thus, the species is endemic to Con Dao National Park in Ba Ria–Vung Tau Province, Vietnam. Furthermore, this study allows us revising the description of A. condaoense with, for the first time, supplemental key taxonomic characteristics and illustrating colourful photographs taken from the fresh materials. A key to all eight known Vietnamese species of sect. Fimbriata is also given

On the CP Violation Phase in a Neutrino Mixing Model with an A4 Flavor Symmetry

Neutrino masses and mixing in an extended standard model acquiring an A4 flavour symmetry are considered. The corresponding three-neutrino mixing matrix obtained via a pertur- bative method allows us to determine the Dirac CP violation phase (\delta_{CP}) as a function of the mixing angles (\theta_{12}, \theta_{23}, \theta_{13}). Then, numerical values and distributions of \delta_{CP} are given. The latter values are quite close to the global fits of the experimental data for both the normal ordering and inverse ordering of the neutrino masses

A new species of Typhonium (Araceae) from Vietnam

Typhonium obtusum is described as a new species endemic to Vietnam. It is unique in the genus in having an oblong-elliptic spathe limb with an obtuse apex and yellowish-greenish filiform staminodes with a down-curved acumen. The ecology, distribution and assessment of the conservation status of the new taxon, as well as a key to all known Typhonium species in Vietnam, are provided

Chemical composition and antibacterial activities of essential oils from Homalomena pierreana (Araceae)

30-37Homalomena is a genus of the Araceae family which contains several remedies used extensively in traditional Vietnamese medicine. H. pierreana is a rare plant species of Homalomena genus and found only in Phu Quoc National Park, Phu Quoc Island, Kien Giang Province, Vietnam. Therefore, the number of studies about this species is limited and the bioactivity of this species is still unknown. In this study, the chemical composition of essential oils was investigated which was isolated from leaves and rhizomes of H. pierreana at the first time by GC-MS. Eight and twelve compounds were identified from the essential oils of rhizomes and leaves, respectively. The major component from both the rhizomes and the leaves was aromadendrene (44 and 48%, respectively). Furthermore, the antibacterial activity of essential oils collected from leaves and rhizomes of H. pierreana was investigated and it was observed that the essential oil of rhizomes could inhibit the growth of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, while the essential oil of leaves exhibited an inhibitory effect against Staphylococcus aureus and Escherichia coli.</em

Chemical profiles and antibacterial activity of acetone extract of two Curcuma species from Vietnam

Curcuma thorelii Gagnep. and Curcuma cotuana Luu, Škorni?k. &amp; H.?.Tr?n are the rare species only found in Southeast Asia. The present study was the first to explore the chemical compositions and antibacterial effects of the whole plant acetone extracts of these 2 species. Altogether 41 and 31 compounds have been identified in C. thorelii and C. cotuana extracts by gas chromatography/mass spectrometry. Accordingly, the C. thorelii extract contained (E)-labda-8(17),12-diene-15,16-dial (33.37%), vitamin E (12.33%), phytol (9.83%) as the major compounds while C. cotuana extract contained predominantly (E)-labda-8(17),12-diene-15,16-dial (14.58%), n-hexadecanoic acid (10.96%), 3,7,11,15-tetramethylhexadec-2-en-1-yl acetate (8.13%), ?-sitosterol (7.97%). In addition, results from disc diffusion assay have shown that C. thorelii acetone extract had inhibitory effects on 5 out of 10 pathogenic bacterial strains such as Bacillus cereus (ATCC 11778), Listeria monocytogenes (ATCC 19111), Staphylococcus aureus (ATCC 25923), S. aureus (ATCC 29213) and S. saprophyticus (BAA750) while C. cotuana acetone extract was found to be effective only against B. cereus. The obtained results showed that the acetone extracts of C. thorelii and C. cotuana possessed several valuable bioactive compounds as well as promising antibacterial activity, which place a good foundation for future pharmaceutical product development

Genetic Diversity and Population Structure of Canarium tramdenum Dai and Yakovl. in Northern Vietnam

Canarium tramdenum occurs naturally in subtropical and tropical regions of Indochina and China. The wood is used for making high quality furniture and the fruit and leaves are used in traditional medicine. However, a lack of information on genetic diversity and population structure has handicapped the genetic conservation and domestication of this high-value species. This study evaluated genetic variation within and among four C. tramdenum populations. Sixty individuals were collected from four natural populations in Vietnam in the provinces of Ninhbinh, Bacgiang, Nghean, and Backan. Genetic diversity and genetic structure were determined using 20 ISSR markers. A total of 192 DNA fragments with sizes ranging from 110 bp to 3,000 bp were detected, of which 154 segments (80.2%) were polymorphic and 38 segments (19.8%) were monomorphic. The ISSR data indicated a moderate degree of genetic diversity for the species (h = 0.252). The four populations were separated into three genetic clusters with low levels of genetic distance between them. AMOVA result showed that most (78%) of the genetic variation was within the populations. The moderate to high genetic diversity of C. tramdenum and the low genetic differentiation among populations suggested that all existing natural populations in the particular regions needed to be preserved to protect the genetic diversity of this species