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Simple Summary: More than 350 species (32 species groups) of Cyrtodactylus Gray, 1827, are reported currently, with a wide distribution from Himalaya, South Asia, Southeast Asia, to Melanesia. Cyrtodactylus tibetanus group, as the earliest Cyrtodactylus diverging clade, are endemic to the Yarlung–Tsangpo River Basin of Tibetan Plateau, only containing two species: C. tibetanus and C. zhaoermii. However, two newly collected Cyrtodactylus specimens from the eastern region of Lang County, Linzhi City, Xizang Autonomous Region, China, were found to be an unnamed taxon of this group based upon the molecular phylogeny, which was conducted using a concatenation data matrix (the partial 16S ribosomal RNA gene (16S), the partial cytochrome c oxidase subunit 1 gene (CO1), and the partial NADH dehydrogenase subunit 2 gene (ND2)) and morphological comparisons, as the new species could be easily identified from other C. tibetanus group species through the absence of the tubercles on dorsum, tail segments, and the tubercles on tails. The new species is currently only known from the type locality with its extremely small populations, with great demand for future investigations to figure out its distribution range, population status, natural history, and mechanisms so that this new species can coexist with Altiphylax medogense. A new Cyrtodactylus species, C. laevissp. nov., from the dry-hot valleys near the Yarlung Zangbo River in Re Village, Jindong Countryside, Lang County, Linzhi City, Xizang Autonomous Region, China, is described herein based upon the integrative taxonomic results combining molecular phylogenetic systematics and morphological characteristic comparisons. Our molecular phylogeny was inferred by combining three mitochondrial gene fragments (16S/CO1/ND2), and it indicated a distinct differentiation between the new species and C. tibetanus species complex, with obvious genetic distances (16S 9.9–11.8%/CO1 16.5–18.2%/ND2 16.6–18.5%) detected, supporting its validity. Morphologically, the new species can be easily distinguished from its congers by the following characters: (1) medium size (SVL 48.58–50.92 mm), (2) tubercles on dorsum sparse, (3) tail segments absent and tubercles on tails absent, (4) supralabials 10–12 and infralabials 8–10, (5) interorbital scales between anterior corners of the eyes 28–32, (6) scale rows at midbody 96–98, (7) ventral scales between mental and cloacal slit 145–153, (8) ventral scale rows 41–45, and (9) 4 to 5 white–yellow transverse bands with brown dots and black merges between the nape and sacrum. The description of C. laevis sp. nov. increased the total species number of C. tibetanus group to three, and the total Cyrtodactylus species number in Xizang to six and in China to eleven. The new species is currently only known from the type locality with its extremely small populations and needs future surveys to reveal its distribution range, population status, natural history, and mechanisms so that the new species can coexist with Altiphylax medogense. [ABSTRACT FROM AUTHOR]

Simple Summary: Cobras (Naja Laurenti, 1768) are a group of well-known highly venomous snakes, which cause numerous cases of snakebites every year, especially in South Asia and Southern China. Taxonomic framework is essential for the medical treatment of snake bites and accurate antivenin development. However, the taxonomy of Asian cobras is still puzzling, especially for the widespread species Monocled Cobra (N. kaouthia Lesson, 1831). This study provided new materials and understanding for the taxonomy of this species by combining mitochondrial phylogenetic analysis and morphological comparisons based on samples from a vast area in Asia. The results showed that the Chinese population of N. kaouthia represents a new species. This study also provided new data for N. atra and designated a neotype for it. Furthermore, the subspecies N. naja polyocellata was resurrected and recognized as a full species, N. polyocellatacomb. nov., and the subspecies N. sumatrana miolepis was also resurrected. This study highlighted the necessity to evaluate the effectiveness of cobra antivenin based on a comprehensive taxonomic framework. Taxonomic frameworks for medically important species such as cobras (genus Naja Laurenti, 1768; Squamata, Elapidae) are essential for the medical treatment of snake bites and accurate antivenin development. In this paper, we described the former N. kaouthia populations recorded from China as a new species and designated a neotype for N. atra-based morphological and mitochondrial phylogenetic analysis. The new species N. fuxisp. nov. was morphologically diagnosed from N. kaouthia by (1) regular single narrow crossband present on the middle and posterior parts of the dorsum (3–15, 7.9 ± 2.7, n = 32) and the dorsal surface of the tail (1–6, 4.2 ± 1.1, n = 32) of both adults and juveniles, buff-colored with dark fringes on both edges, vs. South Asian populations (n = 39) and Southeast Asian populations (n = 35) without cross bands, with irregular cross bands or multiple light-colored crossbands pairs, or densely woven lines; (2) small scales between the posterior chin shields, usually three (40%) or two (37%), rarely four (13%), or one (10%) (n = 30) vs. mostly one (81%) and rarely two (19%) (n = 28); (3) ventrals 179–205 (195.4 ± 6.7, n = 33) vs. South Asian populations 179–199 (188.7 ± 5.9, n = 12); Southeast Asian populations 168–186 (177.8 ± 4.9, n = 18). Phylogenetically, the new species forms an independent sister clade to the clade including N. atra, N. kaouthia, N. oxiana and N. sagittifera. Furthermore, the subspecies N. naja polyocellata should be resurrected and recognized as a full species, N. polyocellatacomb. nov., and the subspecies N. sumatrana miolepis should be resurrected. [ABSTRACT FROM AUTHOR]

Stochastic resonance is widely applied to detect weak signal in a strong noise background because it can enhance the signal-to-noise ratio (SNR). A weak single frequency signal detection method based on under-sampling stochastic resonance is proposed to solve the problem that traditional stochastic resonance can be only applied to deal with small parameter signals. Stochastic resonance is successfully expanded into the applications of the large parameter signals on the basis of scale-transformation and retrieve technology in the under-sampling stochastic resonance. Moreover, the algorithm overcomes the limit that signal frequency must be more than 50 times of the sampling frequency in the second sample algorithm. The model of weak signal detection based on under-sampling stochastic resonance is put forward. Finally, detecting the weak single frequency signal under SNR = -27 dB background by the method proposed in this paper is simulated. The result proves the validity of the method. The sampling frequency in the method is much less than that in the traditional methods and this is helpful to apply stochastic resonance in improving the performance of the Costas loop. [ABSTRACT FROM AUTHOR]