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Papers by Tran van Thanh
Conservation Genetics, 2007
Vietnam’s elephant population that has suffered severe declines during the past three decades is ... more Vietnam’s elephant population that has suffered severe declines during the past three decades is now believed to number 60–80 individuals in the wild. Cat Tien National Park is thought to be one of the key areas for the recovery of Vietnam’s elephants. We carried out a molecular genetic study of elephants in Cat Tien National Park and its adjoining areas with the objectives of estimating minimum population size, assessing genetic diversity, and obtaining insights into social organization. We obtained a minimum population size of 11 elephants based on a combination of unique nuclear microsatellite genotypes and mitochondrial haplotypes. While mitochondrial diversity based on a 600-base pair segment was high in this small sample of individuals, the six microsatellite loci examined showed low diversity and the signature of a recent population bottleneck. Along with nuclear genetic depauperation of Cat Tien’s elephants, we also report disruption of normal social organization, with different matrilines having coalesced into a single social group because of anthropogenic disturbance. The results emphasize the critical condition of this elephant population and the need for urgent conservation measures if this population is to be saved.
Oryx, 2008
This study updates the status and conservation of the Endangered Asian elephant Elephas maximus i... more This study updates the status and conservation of the Endangered Asian elephant Elephas maximus in Cat Tien National Park, Vietnam. Line transect indirect surveys, block surveys for elephant signs, village surveys of elephant-human conflict incidents, guard-post surveys for records of sightings, and surveys of elephant food plants were undertaken during the dry and wet seasons of 2001. A minimum of 11 elephants and a maximum of 15-17 elephants was estimated for c. 500 km 2 of the Park and its vicinity. The elephants are largely confined to the southern boundary of the Park and make extensive use of the adjoining La Nga State Forest Enterprises. During the dry season the elephants depend on at least 26 species of wild and cultivated plants, chiefly the fruits of cashew. Most of the villages surveyed reported some elephant-human conflict. Two adult male elephants seem to cover a large area to raid crops, whereas the family groups restrict themselves to a few villages; overall, the conflict is not serious. Since 2001 there have been no reports of any deaths or births of elephants in the Park. We make recommendations for habitat protection and management, increasing the viability of the small population, reducing elephant-human conflicts, and improving the chances of survival of the declining elephants of this Park. The Government has now approved an Action Plan for Urgent Conservation Areas in Vietnam that calls for the establishment of three elephant conservation areas in the country, including Cat Tien National Park.
Archives of Pharmacal Research, 2011
A new flavonoid glycoside, globlin A (1), and eleven known compounds were isolated from methanoli... more A new flavonoid glycoside, globlin A (1), and eleven known compounds were isolated from methanolic extracts of the leaves of Glochidion obliquum. The structure of this new compound was established with a combination of 2D NMR techniques (COSY, NOESY, HMQC and HMBC) and HR-ESI-MS analyses. Chemical structures of the other known compounds were identified by comparison of their spectroscopic and physical data with those reported in the literature. Some of the isolates were examined for their bioactivities. Among the tested compounds, rotundic acid (4) displayed significant cytotoxicity and anti-inflammatory activities.
Other by Tran van Thanh
Bà i 1. Cho hì nh chóp S.ABCD cóđáy ABCD là hình thoi ca ̣ nh, Go ̣ i M, N lâ ̀ n lươ ̣ t ... more Bà i 1. Cho hì nh chóp S.ABCD cóđáy ABCD là hình thoi ca ̣ nh, Go ̣ i M, N lâ ̀ n lươ ̣ t là trung điê ̉ m SC, AB.
Books by Tran van Thanh
no, 2007
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Conservation Genetics, 2007
Vietnam’s elephant population that has suffered severe declines during the past three decades is ... more Vietnam’s elephant population that has suffered severe declines during the past three decades is now believed to number 60–80 individuals in the wild. Cat Tien National Park is thought to be one of the key areas for the recovery of Vietnam’s elephants. We carried out a molecular genetic study of elephants in Cat Tien National Park and its adjoining areas with the objectives of estimating minimum population size, assessing genetic diversity, and obtaining insights into social organization. We obtained a minimum population size of 11 elephants based on a combination of unique nuclear microsatellite genotypes and mitochondrial haplotypes. While mitochondrial diversity based on a 600-base pair segment was high in this small sample of individuals, the six microsatellite loci examined showed low diversity and the signature of a recent population bottleneck. Along with nuclear genetic depauperation of Cat Tien’s elephants, we also report disruption of normal social organization, with different matrilines having coalesced into a single social group because of anthropogenic disturbance. The results emphasize the critical condition of this elephant population and the need for urgent conservation measures if this population is to be saved.
Oryx, 2008
This study updates the status and conservation of the Endangered Asian elephant Elephas maximus i... more This study updates the status and conservation of the Endangered Asian elephant Elephas maximus in Cat Tien National Park, Vietnam. Line transect indirect surveys, block surveys for elephant signs, village surveys of elephant-human conflict incidents, guard-post surveys for records of sightings, and surveys of elephant food plants were undertaken during the dry and wet seasons of 2001. A minimum of 11 elephants and a maximum of 15-17 elephants was estimated for c. 500 km 2 of the Park and its vicinity. The elephants are largely confined to the southern boundary of the Park and make extensive use of the adjoining La Nga State Forest Enterprises. During the dry season the elephants depend on at least 26 species of wild and cultivated plants, chiefly the fruits of cashew. Most of the villages surveyed reported some elephant-human conflict. Two adult male elephants seem to cover a large area to raid crops, whereas the family groups restrict themselves to a few villages; overall, the conflict is not serious. Since 2001 there have been no reports of any deaths or births of elephants in the Park. We make recommendations for habitat protection and management, increasing the viability of the small population, reducing elephant-human conflicts, and improving the chances of survival of the declining elephants of this Park. The Government has now approved an Action Plan for Urgent Conservation Areas in Vietnam that calls for the establishment of three elephant conservation areas in the country, including Cat Tien National Park.
Archives of Pharmacal Research, 2011
A new flavonoid glycoside, globlin A (1), and eleven known compounds were isolated from methanoli... more A new flavonoid glycoside, globlin A (1), and eleven known compounds were isolated from methanolic extracts of the leaves of Glochidion obliquum. The structure of this new compound was established with a combination of 2D NMR techniques (COSY, NOESY, HMQC and HMBC) and HR-ESI-MS analyses. Chemical structures of the other known compounds were identified by comparison of their spectroscopic and physical data with those reported in the literature. Some of the isolates were examined for their bioactivities. Among the tested compounds, rotundic acid (4) displayed significant cytotoxicity and anti-inflammatory activities.
Bà i 1. Cho hì nh chóp S.ABCD cóđáy ABCD là hình thoi ca ̣ nh, Go ̣ i M, N lâ ̀ n lươ ̣ t ... more Bà i 1. Cho hì nh chóp S.ABCD cóđáy ABCD là hình thoi ca ̣ nh, Go ̣ i M, N lâ ̀ n lươ ̣ t là trung điê ̉ m SC, AB.
no, 2007
Hướng dẫn Geogebra