Anion influences on reactivity and NMR spectroscopic features of NHC precursors

10.1039/c8ra05839cRSC Advances86134960-3496

The tadpoles of five Megophrys Horned frogs (Amphibia: Megophryidae) from the Hoang Lien Range, Vietnam

Frogs in the genus Megophrys are an Asian radiation of stream-breeding frogs. The tadpoles of many Megophrys species are undescribed; those that are described are often dubiously allocated to species by association with post metamorphic specimens at collection sites and without supportive molecular data. We provide detailed descriptions of the larvae of five species of Megophrys from the Hoang Lien Range in northwest Vietnam: Megophrys fansipanensis, M. gigantica, M. hoanglienensis, M. jingdongensis and M. maosonensis. Tadpoles from different subgenera differ from each other via a combination of patternation in life, oral disc shape and tail morphology but given the small sample size, and limited number of species it is unlikely that these differences can be applied more widely to delineate subgenera. Morphological differences between tadpoles from species within the subgenus Panophrys were insufficient to clearly delineate all species. The ability to identify tadpoles is likely to advance our understanding of the frog fauna in mainland southeast Asia

Two new and potentially highly threatened Megophrys Horned frogs (Amphibia: Megophryidae) from Indochina’s highest mountains

Megophrys are a group of morphologically conserved, primarily forest-dependent frogs known to harbour cryptic species diversity. In this study, we examined populations of small-sized Megophrys from mid- and high elevation locations in the Hoang Lien Range, northern Vietnam. On the basis of morphological, molecular and bioacoustic data, individuals of these populations differed from all species of Megophrys known from mainland Southeast Asia north of the Isthmus of Kra and from neighbouring provinces in China. Further, the newly collected specimens formed two distinct species-level groups. We herein describe two new species, Megophrys fansipanensis sp. nov. and Megophrys hoanglienensis sp. nov. Both new species are range restricted and likely to be highly threatened by habitat degradation. These discoveries highlight the importance of the Hoang Lien Range for Vietnam’s amphibian diversity

The Vietnamese population of Megophrys kuatunensis (Amphibia: Megophryidae) represents a new species of Asian horned frog from Vietnam and southern China

The Asian frog genus Megophrys is a diverse group of morphologically conserved, forest-dwelling frogs. The genus harbours highly localised species diversification and new species continue to be described on a regular basis. We examined the taxonomic status of a population of Megophrys frogs from the Hoang Lien Range in northern Vietnam and southern China previously identified as M. kuatunensis (subgenus Panophrys). Preliminary phylogenetic analyses using a fragment of 16S rDNA places the species in question within the Megophrys (subgenus Panophrys) species group, a primarily Chinese radiation within the genus. On the basis of morphological, molecular and bioacoustic data, we conclude that this population does not represent M. kuatunensis, or any known species in the genus. We herein describe this species of Megophrys as new. Known only from Sa Pa District, Lao Cai Province in Vietnam and Jinping County, Yunnan Province in China, the new species is likely to be threatened by ongoing deforestation in the region. We provide an updated species description of M. kuatunensis based on type specimens, and suggest that M. kuatunensis is likely to be restricted to eastern China

A new potentially Endangered species of Megophrys from Mount Ky Quan San, northwest Vietnam

The genus Megophrys is known to harbour morphological cryptic species diversity. During field work on Vietnam’s third highest peak, Mount Ky Quan San, north-west Vietnam, we collected specimens of a new species of Megophrys at two locations more than 2000 m above sea level (asl). Phylogenetic analyses using mitochondrial markers place the new species within the subgenus Panophrys, a primarily Chinese radiation within the genus Megophrys. We describe the species based on an all-male type series and distinguish it from all other Megophrys species from mainland Southeast Asia, north of the Isthmus of Kra and nearby provinces of China (Yunnan, Guangxi and Guizhou) based on morphological, molecular and bioacoustic data. The new species is inferred to form a clade along with M. hoanglienensis and M. fansipanensis; it is syntopic with the former but has a non-overlapping range with the latter. Uncorrected p distances for the 16S rDNA and CO1 genes between the new species and closest relatives exceed values observed between other closely related species in the Panophrys subgenus. The new species is most similar to M. fansipanensis in terms of morphology, and several call parameters also overlap with this species; however, these two species call at different times of year. This is the fourth likely range-restricted and Endangered Megophrys species described from the Hoang Lien Range since 2017, and this discovery further highlights the significance of the Hoang Lien Range for Vietnam’s amphibian diversity

Removal of Congo red and malachite green from aqueous solution using heterogeneous Ag/ZnCo-ZIF catalyst in the presence of hydrogen peroxide

The bimetallic Zn/Co zeolitic imidazole frameworks (ZnCo-ZIFs) were successfully synthesized by a simple solvothermal method at room temperature. Silver elements were afterward doped onto the bimetallic frameworks to form Ag/ZnCo-ZIFs via a facile impregnation method in acetone solvent. The as-synthesized material was used as a heterogeneous catalyst for the removal reaction of Congo red (CR) and malachite green (MG) in the presence of hydrogen peroxide (H2O2). Effects of catalyst dosage, H2O2 concentration, initial concentration of the contaminants, reaction temperature, and reaction time were conducted in this work. The results showed that more than 94% and 98% removal of CR and MG were, respectively, achieved within 45 and 30 min. The presence of Ag also enhanced the removal efficiency of CR and MG. The main mechanism of removal reaction of the organic contaminants could be oxidation via hydroxyl radicals. Moreover, the catalytic activity of the material remained over 90% after four recycling cycles. Due to the efficient reactivity as well as high stability, Ag/ZnCo-ZIFs can be a potential heterogeneous catalyst to remove hazardous dyes from aqueous solution

The economics of land fragmentation in the north of Vietnam *

Land fragmentation, where a single farm has a number of parcels of land, is a common feature of agriculture in many countries, especially in developing countries. In Vietnam, land fragmentation is common, especially in the north. For the whole country, there are about 75 million parcels of land, an average of seven to eight plots per farm household. Such fragmentation can be seen to have negative and positive benefits for farm households and the community generally. Comparative statics analysis and analysis of survey data have led to the conclusion that small-sized farms are likely to be more fragmented, and that fragmentation had a negative impact on crop productivity and increased family labour use and other money expenses. Policies which allow the appropriate opportunity cost of labour to be reflected at the farm level may provide appropriate incentives to trigger farm size change and land consolidation. Policies which tip the benefits in favour of fewer and larger plots, such as strong and effective research and development, an active extension system and strong administrative management, may also lead to land consolidation. Copyright 2007 The Authors Journal Compilation 2007 Australian Agricultural and Resource Economics Society Inc. and Blackwell Publishers Ltd .