Natural history and biology of the Tiannan Crocodile Newt, Tylototriton yangi (Urodela: Salamandridae) at Gejiu, Yunnan province, China with its conservation implications

The natural history of newly discovered species among the genus Tylototriton in South-Eastern Asia is poorly known to date, and most of the species are threatened by extinction. The description of their ecology is crucial to determine their survival status and successful reproduction for conservation purposes. In this study, we assessed the microhabitat preferences of Tylototriton yangi at the type locality, Gejiu, Yunnan province, China, with the Visual Encounter Survey method and by using new important materials. The main habitat is located within a humid subtropical climate and is composed of a large karstic mountain containing some patch of secondary mixed forests and plantations such as tomato fields, pepper and cabbage that are surrounded by scrubs, grasses and small ponds. We provided a complete diagnosis with new morphological data analysing ten adult individuals from the type series to establish a formal description which is absent from the first original description. We compared our results with other related taxa of the genus Tylototriton to updated key determinants between similar species. Thus, we analysed the population structure and the behaviour of T. yangi during a period of ten years, 2008–2017, to assess its survival status and to determine the main threat factors. A total of 186 specimens were found during the whole study predicting a small population inhabiting the type locality, Gejiu. Consequently, T. yangi is now regarded as a highly threatened species that need more attention of Chinese authorities and we suggest regarding it as Endangered due to its small distribution range, the low number of adult specimens observed and ongoing exploitation

Regulation of the Fear Network by Mediators of Stress: Norepinephrine Alters the Balance between Cortical and Subcortical Afferent Excitation of the Lateral Amygdala

Pavlovian auditory fear conditioning involves the integration of information about an acoustic conditioned stimulus (CS) and an aversive unconditioned stimulus in the lateral nucleus of the amygdala (LA). The auditory CS reaches the LA subcortically via a direct connection from the auditory thalamus and also from the auditory association cortex itself. How neural modulators, especially those activated during stress, such as norepinephrine (NE), regulate synaptic transmission and plasticity in this network is poorly understood. Here we show that NE inhibits synaptic transmission in both the subcortical and cortical input pathway but that sensory processing is biased toward the subcortical pathway. In addition binding of NE to β-adrenergic receptors further dissociates sensory processing in the LA. These findings suggest a network mechanism that shifts sensory balance toward the faster but more primitive subcortical input

A new species of Zhangixalus (Anura, Rhacophoridae) from Yunnan, China

We described herein Zhangixalus yunnanensis sp. nov., a new treefrog species from central and western Yunnan, China, which had previously been confused with Z. nigropunctatus, based on morphological and molecular evidence. Our phylogenetic analyses revealed that the new species is sister to the clade of Z. nigropunctatus and Z. melanoleucus with strong support (100% and 73% for BI and ML, respectively). Our morphological analysis suggested that Z. yunnanensis sp. nov. is distinctly different from all known congeners by the combination of the following morphological characters: black blotches on body flank and hind-limb, medium body size (SVL31.3–36.0 mm in males and 47.6–48.6 mm in females), head wider than long, iris yellowish-brown, dorsum uniformly green, vocal sac external, throat black, webbing greyish and fingers webbed one third and toes webbed half. Additionally, we revealed that the specimens ROM 38011 (Sa Pa, Vietnam) and VNMN 4099 (Son La, Vietnam) are neither Z. dorsoviridis nor Z. nigropunctatus, but probably represent one or two cryptic species of Zhangixalus pending further morphological and molecular data. Including the new species described herein, the genus Zhangixalus currently comprises 42 species, 30 of which are distributed in China with 11 species known from Yunnan. Amongst different zoogeographic regions in Yunnan, south-eastern Yunnan has the highest diversity of Zhangixalus, followed by western Yunnan and southern Yunnan. More studies are required to clarify the species diversity of this genus based on multiple lines of evidence (e.g. morphological and molecular data)

Probing flavor changing interactions in hadron collisions

The subprocess $gg \to t\bar{c}+\bar{t}c$ in the two-Higgs-doublet model with flavor-changing scalar couplings is examined at the one loop level. With perturbative QCD factorization theorem, the corresponding cross sections for hadron-hadron collisions are computed numerically. The results are applicable to the whole mass range of the weakly coupled Higgs bosons. In case we could efficiently exclude the severe backgrounds of the $t\bar{c}(\bar{t}c)$ production signal, probing the flavor-changing top-charm-scalar vertex at hadron colliders would be very promising and accessible experimentally.Comment: LaTex file, 14 pages, 8 EPS figure

Efficient surface water flow simulation on static Cartesian grid with local refinement according to key topographic features

Aiming at improving the computational efficiency without accuracy losses for surface water flow simulation, this paper presents a structured but non-uniform grid system incorporated into a Godunov-type finite volume scheme. The proposed grid system can detect the key topographic features in the computational domain where high-resolution mesh is in need for reliably solving the shallow water equations. The mesh refinement is automatically carried out in these areas while the mesh in the rest of the domain remains coarse. The criterion determining the refinement is suggested by a dimensionless number with a fixed value of 0.2 after sensitivity analysis. Three laboratory and field-scale test cases are employed to demonstrate the performance of the model for flow simulations on the new non-uniform grids. In all of the tests, the grid system is shown to successfully generate high-resolution mesh only in those areas with abruptly changing topographic features that dominate the flooding processes. To produce numerical solutions of similar accuracy, the non-uniform grid based model is able to accelerate by about two times comparing with the fine uniform grid based counterpart

New Record of the Leopard Gecko Goniurosaurus araneus (Squamata: Eublepharidae) for China and Habitat Partitioning between Geographically and Phylogenetically Close Leopard Geckos

Two specimens of the Leopard Gecko Goniurosaurus araneus (Squamata: Eublepharidae) were collected from Nonggang National Nature Reserve, Chongzuo Prefecture, Guangxi Zhuang Ethnicity Autonomous Region, China, in October 2011. This species is a new record for China and this report is a range extension for the species from northern Vietnam to southern Guangxi. A phylogenetic study demonstrated that Goniurosaurus araneus and G. luii are a species pair. We show for the first time that they coexist broadly but are narrowly allopatric in a small area in southern Guangxi, separated only by a river, similar to what had been reported previously for G. yingdeensis and Goniurosaurus indet. from northwestern Guangdong. A river as a geographical barrier, elevation, and aspect may have contributed to habitat partitioning between G. araneus and G. luii

A Recurrent Network in the Lateral Amygdala: A Mechanism for Coincidence Detection

Synaptic changes at sensory inputs to the dorsal nucleus of the lateral amygdala (LAd) play a key role in the acquisition and storage of associative fear memory. However, neither the temporal nor spatial architecture of the LAd network response to sensory signals is understood. We developed a method for the elucidation of network behavior. Using this approach, temporally patterned polysynaptic recurrent network responses were found in LAd (intra-LA), both in vitro and in vivo, in response to activation of thalamic sensory afferents. Potentiation of thalamic afferents resulted in a depression of intra-LA synaptic activity, indicating a homeostatic response to changes in synaptic strength within the LAd network. Additionally, the latencies of thalamic afferent triggered recurrent network activity within the LAd overlap with known later occurring cortical afferent latencies. Thus, this recurrent network may facilitate temporal coincidence of sensory afferents within LAd during associative learning