Search

In this work, polypyrrole-based nanocomposites doped with graphene oxide, molybdate, and salicylate (PPy/GO/Mo/Sal) were synthesized via in situ electrochemical polymerization to enhance the anti-corrosion protection performance of polymer coatings. The morphology and structures of the coatings were characterized by SEM, EDX, FTIR, Raman spectroscopy, and XRD. The protection abilities of coatings against corrosion were investigated in 0.1 M NaCl solution with EIS potentiodynamic polarization, salt spray test, and open-circuit potential (OCP) measurements. The results showed that with the presence of both molybdate/salicylate and GO in the PPy matrix, the nanocomposite coating exhibited an excellent protection ability against corrosion for low-carbon steel, better than that with only GO as filler. Compared to the nanocomposites doped with only salicylate or salicylate/GO, the one doped with both molybdate/salicylate and GO exhibited the longest protection plateau (ca. 100 h) on the OCP-time curves with some fluctuation points known as the self-healing action of molybdate dopant. It also resulted in a decrease in the corrosion current (Tafel plots), a higher impedance (Bode plot), and a better protection performance in salt spray tests. In this case, the anti-corrosion ability of the coatings was provided through a barrier and self-healing mechanism.

Strategy game and simulation application are an exciting area with many opportunities for study and research. Currently most of the existing games and simulations apply hard coded rules so the intelligence of the computer generated forces is limited. After some time, player gets used to the simulation making it less attractive and challenging. It is also costly and tedious to incorporate new rules for an existing game. The main motivation behind this research project is to improve the quality of artificial intelligence- (AI-) based on various techniques such as qualitative spatial reasoning (Forbus et al., 2002), near-optimal hierarchical pathfinding (HPA*) (Botea et al., 2004), and reinforcement learning (RL) (Sutton and Barto, 1998).

The endangered crocodile lizard, Shinisaurus crocodilurus, is seriously imperiled by anthropogenic threats, including habitat loss and degradation and most critically over-collection for the international pet trade. As a result, population sizes of crocodile lizards have sharply declined throughout their range, with only a small number remaining in China and a handful of individuals left in Vietnam. To prioritize conservation measures for the species, in this study, we generate new mitochondrial sequences of important new samples and analyze them with existing data. Our results confirm a new genetically distinct population in China, highlighting cryptic genetic diversity within the species. The assessment of climate change impacts on the species suggests that the suitable habitat of one population in China will become severely fragmented, decreased in size, and shifted, while the habitat of two other Chinese populations will remain stable and may even expand given future climate scenarios. In Vietnam, Yen Tu Mountain Range is predicted to serve as a refuge in different climate change projections, but suitable habitat in the border area between Vietnam and China will likely shift geographically. Based on our results, we recommend further field surveys to locate the natural distribution range of the newly identified molecular clade in China and determine the distribution extension of the Vietnamese population in the border area, especially potential occurrence on the Chinese side. Considering the impacts of climate change on the Vietnamese population, designing a corridor to connect the subpopulation’s habitat in the border area with nature reserves in Yen Tu Mountain Range and/or translocating lizards from the site to more suitable habitats might help secure the subpopulation in the context of climate change. In all recommended conservation measures, close collaboration between Vietnam and China will be crucial to effectively protect this potentially shared subpopulation of the highly threatened species.

The Cao Vit Gibbon (Nomascus nasutus) is a critically endangered species of gibbon that was historically wide-ranging but is now known to occupy only one forest patch that straddles the China-Vietnam border. While past and current threats to the species include poaching and habitat destruction, the potential effects of global climate change on this species and its current habitat are still poorly known. Species Distribution Modeling (SDM) is often used to predict the risk of potential species distribution shifts in response to climate change and inform conservation planning including restoration and reintroduction efforts. Here, we present optimally tuned SDMs to predict climatically suitable habitat for N. nasutus, projected under a range of future climate change scenarios. Our SDMs showed high predictive performance and successfully predicted the current known range, but also showed expected areas of overprediction to a much wider area that likely reflects the historical distribution of the Cao Vit Gibbon across southern China and northern Vietnam. SDMs that projected across a range of future scenarios estimated an overall loss in total area of climatically suitable habitat, with the average value of about -23,000 km2 in 2041 – 2060 period and about -25,000 km2 in 2061 – 2080 period, compared to the current predicted range, but they also predicted the currently occupied Trung Khanh-Jingxi Forest as suitable across all future scenarios. Thus, some of the predicted climatically suitable areas that are close to the current known range may be worth targeting for future habitat restoration and population re-establishment and recovery efforts, while balancing other threats and management concerns.

The Cao Vit Gibbon (Nomascus nasutus) is a critically endangered species of gibbon that was historically wide-ranging but is now known to occupy only one forest patch that straddles the China-Vietnam border. While past and current threats to the species include poaching and habitat destruction, the potential effects of global climate change on this species and its current habitat are still poorly known. Species Distribution Modeling (SDM) is often used to predict the risk of potential species distribution shifts in response to climate change and inform conservation planning including restoration and reintroduction efforts. Here, we present optimally tuned SDMs to predict climatically suitable habitat for N. nasutus, projected under a range of future climate change scenarios. Our SDMs showed high predictive performance and successfully predicted the current known range, but also showed expected areas of overprediction to a much wider area that likely reflects the historical distribution of the Cao Vit Gibbon across southern China and northern Vietnam. SDMs that projected across a range of future scenarios estimated an overall loss in total area of climatically suitable habitat, with the average value of about -23,000 km2 in 2041 – 2060 period and about -25,000 km2 in 2061 – 2080 period, compared to the current predicted range, but they also predicted the currently occupied Trung Khanh-Jingxi Forest as suitable across all future scenarios. Thus, some of the predicted climatically suitable areas that are close to the current known range may be worth targeting for future habitat restoration and population re-establishment and recovery efforts, while balancing other threats and management concerns.

How to choose the most appropriate courses to study throughout the learning process remains a question interested in by many students. Students often choose suitable courses according to their interests, needs, and advice from supporting staff, etc. This paper presents the results in developing a course recommendation system that will select appropriate courses for each student studying a major in the following semesters based on his/her current academic performance. We have applied several techniques based on data mining and learning analytics to predict students' learning outcomes in the next semester and developed a model to select the appropriate courses based on such a recommendation system. Besides, our study has focused on comparing the effectiveness of predictive learning methods based on collaborative filtering. Experiments analyzed the learning results of 510 students who enrolled in the courses from 2015 to 2019 and showed that the Matrix Factorization method is the most effective. Also, the paper has proposed procedures and constraints applicable to different training curricula.

The Rosy Litter Frog (Leptobrachella eos) is known from Thailand, Laos, and Vietnam. Knowledge about the natural history of this species is virtually lacking. As a result of our field work in Son La, Nghe An, and Ha Tinh provinces of Vietnam, we provide data on the food composition of L. eos for the first time. Using the stomach-flushing method, we analyzed stomach contents of 34 individuals (23 males and 11 females) from a total of 42 frogs, with stomachs of five males and three females (19%) being empty. A total of 13 prey categories were observed in the stomachs of L. eos , with 232 items, comprising 230 items of invertebrates and two unidentified items. The most important (IRI) groups among the prey of L. eos were Blattodea (26.31%), Araneae (17.26%), Orthoptera (13.21%), Coleoptera (12.39%), and Opiliones (10.09%). There was an overlap of 51.11 % in the diet between males and females, The trophic spectrum of males comprising 11 prey categories revealed to be wider than that of females comprising nine prey categories. Despite differences in diets between the sexes, Blattodea, Orthoptera, Araneae, Coleoptera, and Opiliones represented the most important prey category for all of them. In addition, we also report a new find of Leptobrachella eos , with a new subpopulation from Ha Tinh Province, Vietnam. [ABSTRACT FROM AUTHOR]

The genus Rotavirus (RV) has been reported as zoonotic, highly prevalent in diarrheic neonates, and possibly activated by gestation. Searching RV prevalence in bovines and checking its presence during convalescence of the animals from the illness are useful for One-Health management. Tests detecting specific genes encoding the virus' capsid VP6 and VP4 with Reverse transcription PCR (RT-PCR) amplification as well as virus antigens with both Immuno-chromatographic assay (ICA) and Shifting assay of standardized direct hemagglutination inhibition (SSDHI) in fecal samples taken individually from both diarrheic and healthy calves and pregnant cows were implemented. The tests showed low percentages of diarrheic calves infected with the virus, implying insignificant contribution of the virus in bovine diarrhea. However, ICA tests which were then performed for checking the virus in feces of a genetically and antigenically proven infected diarrheic calf daily during the course of illness and daily through a week after diarrhea stopped showed that the virus had a role in causing the illness. Meanwhile, specific antibody titration with hemagglutination inhibition (HI) reactions implemented with serum samples of locally reared slaughtered and live cattle showed a significantly (P = 0.0008) higher rate of the virus infection. The outcomes of the tests showed that application of the system of HA-HI-SSDHI with the use of RotaTeq vaccine is feasible in investigation of RV though the targets are restricted to bovine-specific P[8] strains. [ABSTRACT FROM AUTHOR]

Background: Xuan Lien Nature Reserve was established in 1999 to protect important habitats and wildlife in the northern part of the Annamites in Vietnam. While Xuan Lien is home to many threatened species, it has experienced a high level of human disturbance over the last decades. To document and provide baseline data on the status and distribution of the terrestrial vertebrate fauna community in the region, we conducted a systematic camera trapping survey in Xuan Lien Nature Reserve in 2023. The data collected during the survey will help design proper conservation measures to better conserve the remaining species. New information: Our study investigates and updates the species richness of mid- to large-sized terrestrial vertebrates, thus providing essential information for developing conservation strategies in Xuan Lien Nature Reserve, Vietnam. As camera traps were set up in a grid-based design, our survey also generated the first-ever systematic data for terrestrial vertebrate fauna in the area. The study covers approximately 21,000 hectares (about 77% of the area), using 35 camera trap stations; each station consists of two cameras. In total, the final dataset consists of 6,276 trap nights, recording at least 46 species in 39 genera. The results suggest that Xuan Lien is a key stronghold for small carnivores, based on the diversity of such species groups in the Reserve. We failed to detect the previously documented Roosevelt's muntjac (Muntiacus rooseveltorum Osgood, 1932) and we only documented a single record of the northern red muntjac (Muntiacus vaginalis Boddaert, 1785). Our survey confirms the severity of overhunting and other anthropogenic threats to the mammal fauna, especially ungulates, in the Reserve. [ABSTRACT FROM AUTHOR]

Background: Based on the examination of specimens of Amolops minutus Orlov & Ho, 2007 and A. ottorum Pham, Sung, Pham, Le, Zieger & Nguyen, 2019, we found that there is no significant morphological difference between them. Phylogenetic analysis also showed that A. minutus and A. ottorum belong to the same taxon. In addition, we discovered the distribution of A. minutus in China. New information: In this study, we provide the first molecular data of Amolops minutus and regard A. ottorum as a junior synonym of A. minutus. In addition, we report the first record of A. minutus from China, based on nine specimens collected from Guanyinshan Provincial Nature Reserve in southern Yunnan Province and present an updated diagnosis of this species, based on literature data and newly-collected specimens. [ABSTRACT FROM AUTHOR]

The Sparreboom's Crocodile Newt (Tylototriton sparreboomi) is a recently discovered species of crocodile newts from Vietnam and it is currently known only from Sin Ho District in Lai Chau Province. Due to the limited information available on its population status and distribution, the species has been classified as Data Deficient in the IUCN Red List. As a result of our field surveys in 2021 and 2022 in north-western Vietnam, novel data on distribution and population status of and threats to this poorly-known species were collected. We combined the newly-discovered locations with previous occurrence records and used the data as input for modelling the potential distribution of the Sparreboom's Crocodile Newt. The results showed that the Sparreboom's Crocodile Newt's potential distribution encompasses areas in Lai Chau, Dien Bien and Son La Provinces, Vietnam, as well as a section in Jinping County, Yunnan Province, China. Based on the findings, we suggest that protected areas in the eastern side of Hoang Lien Mountain Range, such as Che Tao, Muong La, Hoang Lien – Van Ban and Bat Xat Nature Reserves and Hoang Lien National Park in Vietnam and Jinping Feishuling Nature Reserve in China be priority sites for the species conservation. Future research and conservation initiatives should prioritise efforts in such areas in an effort to find and protect new populations of the newt. [ABSTRACT FROM AUTHOR]