18 research outputs found
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Diet of the Annamese langur (Trachypithecus margarita) (Elliot, 1909) at Takou Nature Reserve, Binh Thuan Province, Vietnam
The Annamese langur (Trachypithecus margarita) was described in 1909 but its ecology, including its feeding behaviour, is still largely unknown. Based on current knowledge of feeding ecology of many Asian langurs, T. margarita is expected to be a generalist herbivore, with seasonal variation in diet. Feeding behaviour of one habituated group of Annamese langurs at Takou Mountain was studied from October 2009 to September 2011. The dietary pattern of these langurs was found to be similar to other Trachypithecus species, which is characterised by a high amount of leaf consumption (54.4% immature leaves, 7.1% mature leaves) and complemented by fruits (29.9%). The Annamese langurs ate plant parts from 31 species belonging to 20 families on Takou Mountain where 689 plant species were known for the mountain. Moraceae is the most important family in the langur's diet with at least 10 species consumed and accounting for 41.1% of feeding time. Based on the current and previous feeding studies of Trachypithecus species, it could be concluded that the genus is a generalist folivore and the dietary pattern is similar among species.</p
Context-Specific Metabolic Networks Are Consistent with Experiments
Reconstructions of cellular metabolism are publicly available for a variety of different microorganisms and some mammalian genomes. To date, these reconstructions are “genome-scale” and strive to include all reactions implied by the genome annotation, as well as those with direct experimental evidence. Clearly, many of the reactions in a genome-scale reconstruction will not be active under particular conditions or in a particular cell type. Methods to tailor these comprehensive genome-scale reconstructions into context-specific networks will aid predictive in silico modeling for a particular situation. We present a method called Gene Inactivity Moderated by Metabolism and Expression (GIMME) to achieve this goal. The GIMME algorithm uses quantitative gene expression data and one or more presupposed metabolic objectives to produce the context-specific reconstruction that is most consistent with the available data. Furthermore, the algorithm provides a quantitative inconsistency score indicating how consistent a set of gene expression data is with a particular metabolic objective. We show that this algorithm produces results consistent with biological experiments and intuition for adaptive evolution of bacteria, rational design of metabolic engineering strains, and human skeletal muscle cells. This work represents progress towards producing constraint-based models of metabolism that are specific to the conditions where the expression profiling data is available
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Associations Between Nutrition, Gut Microbiome, and Health in A Novel Nonhuman Primate Model.
Red-shanked doucs (Pygathrix nemaeus) are endangered, foregut-fermenting colobine primates which are difficult to maintain in captivity. There are critical gaps in our understanding of their natural lifestyle, including dietary habits such as consumption of leaves, unripe fruit, flowers, seeds, and other plant parts. There is also a lack of understanding of enteric adaptations, including their unique microflora. To address these knowledge gaps, we used the douc as a model to study relationships between gastrointestinal microbial community structure and lifestyle. We analyzed published fecal samples as well as detailed dietary history from doucs with four distinct lifestyles (wild, semi-wild, semi-captive, and captive) and determined gastrointestinal bacterial microbiome composition using 16S rRNA sequencing. A clear gradient of microbiome composition was revealed along an axis of natural lifestyle disruption, including significant associations with diet, biodiversity, and microbial function. We also identified potential microbial biomarkers of douc dysbiosis, including Bacteroides and Prevotella, which may be related to health. Our results suggest a gradient-like shift in captivity causes an attendant shift to severe gut dysbiosis, thereby resulting in gastrointestinal issues
New records of home range of Tonkin snub-nosed monkey (Rhinopithecus avunculus Dollman, 1912) in Khau Ca forest, Ha Giang province
The Tonkin snub-nosed monkey presently is known from four small and isolated populations in Tuyen Quang province (Na Hang and Cham Chu district) and Ha Giang province (Khau Ca and Tung Vai of Quan Ba district). It is listed as “Critically Endangered” in the IUCN’s red list of threatened animals, and as one of the top 25 most endangered primates of the world [10]. This study focused on reviewing previous research on home range size in Vietnam and daily range length of TSNM in Khau Ca area, Ha Giang province. According to Fleagle (1999), the home range of a primate or primate group consists of the day ranges or daily path lengths, that the primate or group uses over a long period of time. Among primatologists this period is usually a year. A day range or daily path length is the distance that an individual or a group moves in a single day (or night). Primate groups frequently use one part of their home range more intensively than others and “this heavily used area is called the core area” [3: 52]. By plotting the day ranges or daily path lengths that occur throughout the year on a map, primatologists can determine the home range of a primate group. Maps of home ranges can help primatologists understand the extent of a species range and document the areas where their species of interest can and cannot inhabit. Knowledge of home ranges and resource use by primates are critical for effective conservation measures. Estimates of the home range of TSNM vary among authors. Le Hien Hao (1973) identified the home range of this species as 1.7 to 3.14 km2. Pham Nhat (1993) reported the average size of home range as 4.55 km2 (Table 8) while Boonratana and Le Xuan Canh (1994, 1998) reported a home range of about 10 km2 for the TSNMs in Tat Ke sector, Na Hang Nature Reserve (Tuyen Quang province). Further, most encounters in Khau Ca are inside the core area of 7 km2. The aim of this study is to calculate the daily range length of the TSNM population that inhabits the Khau Ca forest, Ha Giang province. Ranging data were collected in May-June, 2008 during a 28 day field season. These data were the result of seven encounters and 26 contact hours with free-ranging R. avunculus groups. Day range lengths were 851.3 m (1st June, 2008) and 673.5 (10th June, 2008)
A review of the distribution of a new gibbon species: the northern yellow-cheeked crested gibbon nomascus annamensis Thinh, Mootnick, Thanh, Nadler and Roos, 2010
Nomascus annamensis is a newly described gibbon endemic to the Indochina peninsula (Cambodia, Laos and Vietnam). We review the published and unpublished literature relevant to N. annamensis to clarify its distribution and help inform conservation management and policy related to this species. The best current distribution estimate for N. annamensis is east of the Mekong River, from 16°55'N to approximately 14°00'N in central Vietnam, and from 16°00'N in the south of Laos to about 13°57'N in northeast Cambodia. There is a large forest tract overlapping the borders of Cambodia, Laos and Vietnam that is probably an important habitat for this gibbon. The distribution and population status of this species in Cambodia and Laos is poorly known, however. In addition, information on the biogeographic boundaries with other gibbon species is still lacking. Various biogeographic barriers based on rivers and forest types have been hypothesized to explain the biogeography of gibbons in this region; however, our review of the evidence suggests that these factors might not fully explain the distribution of Nomascus annamensis and its close relatives (N. siki and N. gabriellae). We propose that climatic conditions may be a driver shaping the distribution of the gibbon. Further studies are needed, therefore, to provide comprehensive information on the distribution of N. annamensis and to clarify its boundaries with adjacent gibbon species