Dalat University Journal of Science / Tạp chí khoa học Đại học Đà Lạt
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THE EFFECT OF ECOLOGICAL FACTORS ON GROWTH OF Sterculia foetida L. IN BUON DON AND EA SUP DISTRICTS, DAK LAK PROVINCE
Get PDFAccurate and reliable assessment of site suitability for the growth of selected plant species is critical for afforestation projects and programs to improve rural livelihoods. This research examines the relationship between growth of Sterculia foetida L. and six ecological factors in Buon Don and Ea Sup districts, Dak Lak Province. The purpose of the research is to predict the growth in average height and trunk diameter of the trees using ecological factors that are easy to measure and observe. These include topography (slope) and soil characteristics (clay ratio, depth of soil layer, surface and subsurface rock concentrations, and agglomeration ratio). The ecological factors were evaluated by multivariable regression analysis of growth data from 31 experimental plots, 16 in Buon Don district and 15 in Ea Sup district. The results show that four of the six factors affect average growth in tree height and that five factors affect average trunk diameter growth. The findings are of practical value for households and agricultural extension officers to consider before planting Sterculia foetida L. in the two areas
THE TAXONOMIC TREAMENT OF CAMELLIA LUUANA (SECT. DALATIA) IN THE CENTRAL HIGHLANDS, VIETNAM
Get PDFCamellia luuana Orel & Curry is known only from its type locality, Ta Dung Nature Reserve, now Ta Dung National Park, Dak Nong Province, the Central Highlands of Vietnam. No characteristics of fruit and seeds, which are the most important to divide genera in Theaceae (Chang & Ren, 1998; Ming & Bartholomew, 2007; Sealy, 1958), were presented in its protologue. After carefully reviewing the protologue, specimens, and images of Camellia luuana, relevant species and genera, and conducting a field investigation around its type locality, we concluded that this species is not a member of Camellia, but a member of Pyrenaria
ENHANCING THE EFFICIENCY OF COMMUNICATION PROGRAMS FOR STUDENT ENROLLMENT AT UNIVERSITIES THROUGH RECIPIENT FEEDBACK (SURVEY OF STUDENTS AT DALAT UNIVERSITY IN 2021)
Get PDFResearching recipient feedback is one of the important actions to enhance the quality of the communication process. This study was conducted to provide some solutions to improve the effectiveness of Dalat University’s enrollment communication process by analyzing student feedback. A survey was conducted in 2021 with a sample of 655 students from Dalat University. The results showed that students mainly knew about Dalat University through word of mouth and the Facebook channel, and that tuition fees, the benchmark, and geographical location were the main reasons students chose the university. In addition, most students showed an interest in receiving content in the form of short videos. The research results can be applied by the communication department of Dalat University and can contribute to the field of university communication research, which has not received much attention in Vietnam
FATTY ACID COMPOSITION AND ANTIOXIDANT ACTIVITY OF CAMELLIA NINHII SEED OIL COLLECTED IN LAM DONG PROVINCE
Get PDFThe seed oil of Camellia ninhii was studied for the first time on its fatty acid composition by gas chromatography-mass spectrometry (GC-MS) and antioxidant activity by the DPPH method. The results show that unsaturated fatty acids account for the largest amount, especially oleic acid with 45.43% of the total sample analyzed. In addition, other fatty acids, palmitic, linoleic, pentadecanoic, and two aromatic acids, benzoic and cinnamic, were present. The sample of C. ninhii seed oil exhibited mild antioxidant activity against DPPH free radicals with IC50 = 0.94 mg/mL
ANTIBACTERIAL ACTIVITY OF SILVER NANOPARTICLES SYNTHESIZED USING ELEUSINE INDICA (L.) GAERTN. LEAF EXTRACT ON THE BACTERIA ISOLATED FROM THE VASE SOLUTION
Get PDFGreen synthesis of silver nanoparticles (SNPs) using Eleusine indica (L.) Gaertn. leaf extract as a reducing agent is reported. SNPs were characterized with UV-Vis spectroscopy and transmission electron microscopy (TEM). The SNPs were rod like and spherical in shape with sizes from 3 to 33 nm and an average size of 16.73 nm. Seven bacterial strains were isolated from the vase water, including Bacillus cereus CA1, Alcaligenes faecalis CA2, Micrococcus luteus CA3, Pantoe agglomerans CA4, Pseudomonas aeruginosa CA5, Pseudomonas aeruginosa CA6, and Pantoe agglomerans CA7. Identifications were made according to Bergey’s Manual of Systematic Bacteriology and Bergey’s Manual of Determinative Bacteriology. The SNPs inhibited the growth of bacteria and exhibited significant antimicrobial activity against different isolated bacteria strains. SEM images showed that the SNPs damaged the cell membranes of bacteria, released plasmic contents, and altered the morphology of the cells. The impact of SNPs on gram-negative bacteria was more severe than on gram-positive bacteria. This study revealed that biosynthesized SNPs from Eleusine indica (L.) Gaertn. leaf extract are potential agents in combating bacterial contamination
MICROPLASTIC FIBER ACCUMULATION IN SOME WILD AND CULTURED SHRIMP SPECIES
Get PDFThis study was conducted to examine the microplastic fiber abundance and its characteristics in two wild and two cultured shrimp species collected at coastal areas in Hoai Nhon district, Binh Dinh Province. A total of 84 individuals of four shrimp species, Litopenaeus vannamei, Penaeus monodon, Metapenaeus ensis, and Penaeus semisulcatus were collected for analysis. All shrimp specimens were dissected to remove the digestive tracts, which were then treated with 10% KOH to collect microplastic fibers by filtering. The microplastic fiber concentrations varied from 1.96 ± 0.09 to 19.33 ± 10.82 fibers/specimen or 0.20 ± 0.12 to 2.26 ± 1.26 fibers/g of wet body weight. The abundance of fibers in the wild shrimps (Penaeus semisulcatus and Metapenaeus ensis) was higher than in the cultured shrimps (Penaeus monodon and Litopenaeus vannamei). Most fibers observed in the four shrimp species had lengths between 300 and 1500 μm, accounting for 78.72% to 92.82% of the total). White fibers were dominant (30.38%), followed by gray (11.87%), and green (10.60%)
THE IMPACT OF PROTESTANTISM ON THE ECONOMY OF THE COHO CHIL PEOPLE IN LAM DONG PROVINCE
Get PDFThis study examines the relationship between Protestantism and the Coho Chil economy using qualitative methods to analyze data from fieldwork in the Coho Chil Protestant communities of Lam Dong Province. The research shows that Protestantism has a positive impact on the economy of the Coho Chil community. This impact is manifested in casting out superstitious and magical practices and in applying economic rationalization. The Protestant doctrine and sermons by clergy have influenced the thinking of the people and their economic performance. Protestantism creates a social network and social capital that not only influences their economic life, but also provides timely material support for Christians in need. This paper serves as an additional resource for research related to the relationship between religion and the economy – an intriguing topic that is not found in much previous research in Vietnam.This study examines the relationship between Protestantism and the Coho Chil economy using qualitative methods to analyze data from fieldwork in the Coho Chil Protestant communities of Lam Dong Province. The research shows that Protestantism has a positive impact on the economy of the Coho Chil community. This impact is manifested in casting out superstitious and magical practices and in applying economic rationalization. The Protestant doctrine and sermons by clergy have influenced the thinking of the people and their economic performance. Protestantism creates a social network and social capital that not only influences their economic life, but also provides timely material support for Christians in need. This paper serves as an additional resource for research related to the relationship between religion and the economy – an intriguing topic that is not found in much previous research in Vietnam
BI-LIPSCHITZ CONTACT INVARIANCE OF RANK
Get PDFWe address the question of whether the Thom-Boardman symbol of a map germ is an invariant with respect to bi-Lipschitz right equivalence. We give a counterexample showing that in general the answer is negative. We prove that the rank of a map germ is a bi-Lipschitz contact invariant. Consequently, the first Thom-Boardman symbol and its length are bi-Lipschitz contact invariants
“I AM MENTALLY HEALTHY, SO I CAN CHOOSE WELL.” QUARTER-LIFE CRISIS AND POSITIVE MENTAL HEALTH IN STUDENTS
Get PDFThe transition from adolescence to adulthood is marked by psychosocial and other psychological changes. Quarter-life crisis is a symptom that appears during the transition period. We examined how quarter-life crisis impacts mental health using a convenience sampling technique. A total of 459 students, 18 to 25 years old, filled out questionnaires distributed online. The data measurement tool used quarter-life crisis and positive mental health scales adjusted into Indonesian form. The results show a significant negative correlation (R = -0.437; p < .001) between quarter-life crisis and positive mental health in students. The regression analysis shows an impact of quarter-life crisis on positive mental health of 19%, which is relatively small. The implications of our research results are discussed
THE IMPACT OF CREATING SHARED VALUE ON PURCHASE INTENTION AND RECOMMENDATION INTENTION: A STUDY IN VIETNAM
Get PDFCreating shared value (CSV) has been predicted as the next evolution of corporate social responsibility. Companies that follow the CSV approach integrate economic, societal, and environmental objectives in their strategy to pursue sustainability and competitive advantages. This study investigates the effects of CSV contributions (which are framed as economic, social, and environmental contributions) on brand attitude, and then the effects of brand attitude on consumer purchase and recommendation intentions. This research also examines the moderating role of perceived personal relevance on the relationships between economic, social, and environmental contributions and brand attitude. The proposed model was empirically tested on a sample of 234 consumers in a metropolitan city in Vietnam. The results confirm that positive links exist between the three CSV contributions and brand attitude as well as between brand attitude and consumer intentions of purchasing and recommending. The study also finds that perceived personal relevance moderates the effect of environmental contribution on brand attitude. These effects help us better understand previous findings in the literature regarding the influence of CSV on consumer intentions and enrich the limited CSV research. Moreover, this study also provides managerial suggestions for companies in making their CSV decisions