The horned toad assemblage, genus Megophrys sensu lato, currently includes three groups previously recognized as the genera Atympanophrys, Xenophrys and Megophrys sensu stricto. The taxonomic status and species composition of the three groups remain controversial due to conflicting phenotypic analyses and insufficient phylogenetic reconstruction; likewise, the position of the monotypic Borneophrys remains uncertain with respect to the horned toads. Further, the diversity of the horned toads remains poorly understood, especially for widespread species. Herein, we evaluate species-level diversity based on 45 of the 57 described species from throughout southern China, Southeast Asia and the Himalayas using Bayesian inference trees and the Generalized Mixed Yule Coalescent (GMYC) approach. We estimate the phylogeny using both mitochondrial and nuclear DNA data. Analyses reveal statistically significant mito-nuclear discordance. All analyses resolve paraphyly for horned toads involving multiple strongly supported clades. These clades correspond with geography. We resurrect the genera Atympanophrys and Xenophrys from the synonymy of Megophrys to eliminate paraphyly of Megophrys s.l. and to account for the morphological, molecular and biogeographic differences among these groups, but we also provide an alternative option. Our study suggests that Borneophrys is junior synonym of Megophrys sensu stricto. We provide an estimation of timeframe for the horned toads. The mitochondrial and nuclear trees indicate the presence of many putative undescribed species. Widespread species, such as Xenophrys major and X. minor, likely have dramatically underestimated diversity. The integration of morphological and molecular evidence can validate this discovery. Montane forest dynamics appear to play a significant role in driving diversification of horned toads.
Cuprous oxide (Cu(2)O) nanoparticles dispersed on reduced graphene oxide (RGO) were prepared by reducing copper acetate supported on graphite oxide using diethylene glycol as both solvent and reducing agent. The Cu(2)O/RGO composite exhibits excellent catalytic activity and remarkable tolerance to methanol and CO in the oxygen reduction reaction.
Southeast Asia and southern China (SEA-SC) harbor a highly diverse and endemic flora and fauna that is under increasing threat. An understanding of the biogeographical history and drivers of this diversity is lacking, especially in some of the most diverse and threatened groups. The Asian leaf-litter frog genus Leptolalax Dubois 1980 is a forest-dependent genus distributed throughout SEA-SC, making it an ideal study group to examine specific biogeographic hypotheses. In addition, the diversity of this genus remains poorly understood, and the phylogenetic relationships among species of Leptolalax and closely related Leptobrachella Smith 1928 remain unclear. Herein, we evaluate species-level diversity based on 48 of the 53 described species from throughout the distribution of Leptolalax. Molecular analyses reveal many undescribed species, mostly in southern China and Indochina. Our well-resolved phylogeny based on multiple nuclear DNA markers shows that Leptolalax is not monophyletic with respect to Leptobrachella and, thus, we assign the former to being a junior synonym of the latter. Similarly, analyses reject monophyly of the two subgenera of Leptolalax. The diversification pattern of the group is complex, involving a high degree of sympatry and prevalence of microendemic species. Northern Sundaland (Borneo) and eastern Indochina (Vietnam) appear to have played pivotal roles as geographical centers of diversification, and paleoclimatic changes and tectonic movements seem to have driven the major divergence of clades. Analyses fail to reject an "upstream" colonization hypothesis, and, thus, the genus appears to have originated in Sundaland and then colonized mainland Asia. Our results reveal that both vicariance and dispersal are responsible for current distribution patterns in the genus.
sive utilization of fossil fuels. The design and development of efficient, economic, and sustainable strategies to convert clean energy (e.g., solar energy, wind energy, and hydropower energy) is thus of great significance. Among various available strategies, electrochemical energy conversion technologies have been attracted extreme attention. They mainly include (photo)electrochemical reduction of atmosphere-rich and greenhouse gas-carbon dioxideinto high value-added chemicals or liquid fuels under mild reaction conditions, electrosynthesis of NH 3 with low energy consumption to substitute the Haber method, electrochemical overall water splitting, and different kinds of fuel cells. By use of these electrochemical energy conversion technologies, it is believed that both the issues of energy shortage and environmental pollution are promising to be solved, eventually creating a globalized system with a sustainable energy circle for our society in the future (Figure 1). [1][2][3][4][5][6][7] To achieve efficient electrochemical conversion technologies, high-performance electrochemical conversion platforms need to be initialized, where electrocatalysts are frequently required. An electrocatalyst actually plays a vital role in the determination and further improvement of reaction rate, efficiency, and selectivity of different electrochemical transformations. In terms of its catalytic performance, the most crucial factors are generally considered as the amount of its active sites, the intrinsic activity of each active site, and the total efficiency of these active sites. [8] It is well-known that the amount of active sites of an electrocatalyst and its electrocatalytic efficiency can be increased through enlarging the surface area of an electrocatalyst, for example by means of synthesizing a nanostructured catalyst (e.g., nanosheets, [9] nanowires, [10] nanopores, [11][12][13] and coreshell structures [14,15] ). Meanwhile, the intrinsic activity of each catalytic site basically follows the Sabatier principle, [16][17][18][19][20] which is closely related to the ability of an electrocatalyst to weaken or strengthen the binding energies with reactants, reaction intermediates, and/or products. For example, when the free energy of hydrogen adsorption (ΔG H ) on the active sites of an electrocatalyst remains at a moderate strength, this catalyst exhibits the highest catalytic activity toward hydrogen evolution reaction (HER). In contrast, too strong or too weak ΔG H on the active sites of an electrocatalyst precludes the HER. [21][22][23] Among numerous electrocatalysts, multiple metal components based electrocatalysts have been extensively utilized in Strain engineering of nanomaterials, namely, designing, tuning, or controlling surface strains of nanomaterials is an effective strategy to achieve outstanding performance in different nanomaterials for their various applications. This article summarizes recent progress and achievements in the development of strain-rich electrocatalysts (SREs) and their applications in the fi...
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