A new species of the genus <italic>Sinomicrurus</italic> (Serpentes: Elapidae) from China and Vietnam

Independence of black and white: Phase-specific adaptation

If a cross figure consists of upper and lower black arms, right and left white arms, and a central gray square, we do not perceive the mosaic sum of these five parts. We see, instead, a black vertical bar and a white horizontal bar. In the central part of this figure, we can see simultaneously two colors, white and black, one behind the other. One of these two colors appears transparent and the other appears to be seen through the former (See Fig. 1A). The following investigation is concerned with this apparent transparency.Method: Experimental procedures were nearly the same with those of our previous studies on figure-ground reversal (This journal, 1955, 26, 178-188). Observers were instructed to fixate their eyes upon the center of the figure 60 to 120 seconds, and push the first one of the three electric buttons when the black bar appeared in front of the white bar, push the second button when the white bar appeared nearer, and push the third button during ambiguous appearances. As the measure of relative dominancy of black and white, the formula, Rb=100Tb/(Tb+Tw), was adopted, in which Tb indicates the total pushing time of the first button, and Tw, that of the second.Results: 1) In general, the white bar has a stronger tendency to appear in front of the black bar when the central square is light gray, and the black bar is dominant when the central square is dark gray. It was discovered that the relative dominancy was approximately proportional to the difference between the square root of reflectance of the central part and that of the arms (Table 1, Fig. 2, 3, 4).2) The lightness of the surrounding field has little effect on the relative dominancy of two bars (Table 2).3) When the arms are of two of the four chromatic colors, red, yellow, green and blue, instead of white and black, and the central part is the mixture of these two colors produced by the rotating disk, yellow is the most dominant color, red is the second, green the third and blue the last. However, red may be more dominant than yellow if the above mentioned effect of lightness is eliminated (Table 3).4) When the vertical arms are red, the horizontal arms are green, and the central square is the mixture of red and green in various ratios, the relative dominancy is represented in a S-shaped curve as a function of the mixture ratio, i.e., the angle ratio in color disk (Table 4, Fig. 5, 6).5) The effect of area of the arms is equivocal. There are large individual differences, and the difference of instructions easily affects the results (Fig. 8, 9, 10, Table 5). The similar results were obtained in the stimulus figures of another type (Fig. 1B, 11).

The mossy frogs of the genus Theloderma Tschudi comprise 28 described taxa (Sivongxay et al. 2016; Frost 2022), which are distributed from north-eastern India and Myanmar to southern China, across the peninsula of Indochina and Malaysia, to Indonesia (Poyarkov et al. 2015; Frost 2022). Theloderma albopunctatum is a small-sized taxon that is assigned to the T.-asperum species complex (Poyarkov et al. 2015, 2018; Sivongxay et al. 2016; Dever 2018). For long time, it has been believed to be a synonym of T. asperum. However, genetic analyses revealed that both taxa show significant differences. Currently, populations south of the Isthmus of Kra (southern Thailand, Malayan peninsular) are assigned to T. asperum, while populations north of it (southern China, northern and central Vietnam, adjacent Laos, south-eastern Cambodia) are assigned to T. albopunctatum. In addition, this species complex might contain further cryptic species (cf. Nguyen et al. 2015; Poyarkov et al. 2015) and according to Chunskul et al. (2021) four genetic groups do exist: group A comprises T. albopunctatum from southern and central Vietnam, Laos, central and north-eastern Thailand; group B is composed of populations from northern Vietnam and China; group C ranges from north-western Vietnam to northern Thailand and Myanmar; and group D is distributed in northern Vietnam (Thanh Hoa).

Bactrocera tau (Walker), a major invasive pest worldwide, was first described in Fujian (China) in 1849 and has dispersed to tropical and subtropical Asia and the South Pacific region. Few data are available on its colonization history and expansion processes. This pilot study attempted to reconstruct the colonization history and pathways of this pest in China and neighboring Southeast Asian countries based on mitochondrial DNA. Results of the study showed six genetic groups corresponding to geographical characteristics, although the pattern was relatively weak. Homogeneous genetic patterns were observed within southern and central China, and northern Vietnam. Continuous colonization from the coast of southern China to inland regions of China and northern Vietnam was suggested. Strong genetic structure was observed in western China, Thailand, and Laos. The isolation of four of the six groups was most probably attributable to major topographical barriers of western China. Yunnan acted as a contact zone of B. tau in China and neighboring Southeast Asia. The absence of isolation by distance and the overall low phylogeographic structure of B. tau suggested that long distance dispersal events and human activities could play a major role in the colonization and expansion patterns of B. tau. By analyzing the genetic diversity, gene flow, haplotype phylogeny, and demographic history of 23 fly populations, we hypothesized that B. tau could have been introduced long ago in southern China, from which it further expanded or that southern China could correspond to the native range of this species.

RNA Interference-mediated Silencing of X11α and X11β Attenuates Amyloid β-Protein Levels via Differential Effects on β-Amyloid Precursor Protein Processing

It is shown that an orientation anisotropy exists for the magnitude of induced brightness in a cruciform stimulus consisting of a grey test patch positioned at the intersection of two inducing bars, one black and one white, oriented at right angles to each other. When the cruciform was oriented such that the white bar was horizontal, the grey patch appeared darker than when the same cruciform was oriented such that the white bar was vertical. The contribution of the black and white inducing bars towards the brightness of the test patch was investigated. A simple mathematical function, which took into account both the contribution of the two component inducing bars and the orientation anisotropy, was fitted to the data. No consistent orientation anisotropy was found with inducing stimuli at oblique orientations.

Perioperative factors including hypoxia, hypocapnia, and certain anesthetics have been suggested to contribute to Alzheimer disease (AD) neuropathogenesis. Desflurane is one of the most commonly used inhalation anesthetics. However, the effects of desflurane on AD neuropathogenesis have not been previously determined. Here, we set out to assess the effects of desflurane and hypoxia on caspase activation, amyloid precursor protein (APP) processing, and amyloid beta-protein (Abeta) generation in H4 human neuroglioma cells (H4 naïve cells) as well as those overexpressing APP (H4-APP cells). Neither 12% desflurane nor hypoxia (18% O(2)) alone affected caspase-3 activation, APP processing, and Abeta generation. However, treatment with a combination of 12% desflurane and hypoxia (18% O(2)) (desflurane/hypoxia) for 6 h induced caspase-3 activation, altered APP processing, and increased Abeta generation in H4-APP cells. Desflurane/hypoxia also increased levels of beta-site APP-cleaving enzyme in H4-APP cells. In addition, desflurane/hypoxia-induced Abeta generation could be reduced by the broad caspase inhibitor benzyloxycarbonyl-VAD. Finally, the Abeta aggregation inhibitor clioquinol and gamma-secretase inhibitor L-685,458 attenuated caspase-3 activation induced by desflurane/hypoxia. In summary, desflurane can induce Abeta production and caspase activation, but only in the presence of hypoxia. Pending in vivo confirmation, these data may have profound implications for anesthesia care in elderly patients, and especially those with AD.

To investigate the molecular epidemiology of a recent HIV-1 outbreak in northern Vietnam and its relation to the epidemic in surrounding areas, we analyzed 17 HIV-positive blood specimens from 3 heterosexuals, 2 sexually transmitted disease patients, and 12 injecting drug users (IDUs), collected in 4 provinces near Hanoi in 1998. These were compared with the specimens from Ho Chi Minh City (n = 10) and An Giang Province (n = 10) in southern Vietnam and with published sequences from neighboring countries. Genetic subtyping based on the env C2/V3 sequences revealed that HIV-1 subtype E predominated throughout Vietnam in all risk populations; the exception was one typical United States-European-type HIV-1 subtype B detected in a patient in Ho Chi Minh City, the first case of HIV infection identified in Vietnam in 1990. The HIV-1 subtype E sequences identified in 9 of the 12 IDUs from northern provinces were closely related phylogenetically to those in IDUs in nearby Guangxi Province of China, and also shared a common amino acid signature downstream of the env V3 loop region. The low interperson nucleotide diversity among IDUs in northern Vietnam supports the view that HIV-1 subtype E was introduced recently among IDUs in northern Vietnam. These data indicate a linkage between HIV-1 circulating among IDUs in northern Vietnam and southern China, and suggest recent transborder introductions as the likely source of HIV-1 subtype E in northern Vietnam.

Although the effects of high-frequency electromagnetic fields on biological systems have been studied frequently, unequivocal results have rarely been obtained, primarily because suitably controlled experiments could not be performed. In the present work, tomato plants were exposed to a homogeneous and isotropic field (900 MHz) using a mode stirred reverberation chamber, and the stress-related transcripts (calmodulin, protease inhibitor and chloroplast mRNA-binding protein) were assayed by real-time quantitative PCR. Exposure to an electromagnetic field induced a biphasic response, in which the levels of all three transcripts increased four-to six-fold 15 min after the end of electromagnetic stimulation, dropped to close to initial levels by 30 min, and then increased again at 60 min. We deliberately focused on the very early molecular responses to high-frequency electromagnetic fields in order to minimize secondary effects.

Opsariichthys duchuunguyeni, a new species of cyprinid fish from Ky Cung-Bang Giang river basin, northern Vietnam, is described. It is characterized by the following unique combination of features: short maxillary extending; 12-15 rounded tubercles on lower jaw; 11-12 crossbars on body; pectoral fin reaching the pelvic fin origin in adult male; lateral- line scales comprising 41; scales above lateral-line 8; scales below lateral-line 3. Moreover, the genetic differentiation and a diagnostic key of the new species and other congeners are given in this paper for discussion about taxonomic status of the genus Opsariichthys from Vietnam and nearby geographical regions, southern China and Taiwan.

A new species of the genus Liurana Dubois, 1986 is described from Medog County, Tibet, China, based on morphological and molecular data. The new species can be differentiated from all other congeners by the following combination of characters: (1) head wider than long; (2) tympanum distinct and large; (3) hindlimb long, tibiotarsal articulation beyond tip of snout when adpressed; (4) belly with flat tubercles, cloacal region with small tubercles; (5) transverse bands distinctly on dorsal limbs, four bands on thigh and three on tibia; and, (6) dark brown marbled patterns or speckles on white belly. Here, we also discuss the distribution pattern of Liurana in the East Himalaya region, the role of the Yarlung Tsangpo River in the speciation and genetic isolation of congeners, the direct developmental mode of reproduction, and the two different ecotypes of the genus. Lastly, we provide conservation recommendations for the genus in southeastern Tibet.

Recovering motion information from luminance

The sodium-calcium exchanger (NCX) is a critical mediator of calcium homeostasis. In the heart, NCX1 predominantly operates in forward mode to extrude Ca(2+); however, reverse-mode NCX1 activity during ischemia/reperfusion (IR) contributes to Ca(2+) loading and electrical and contractile dysfunction. IR injury has also been associated with altered fat metabolism and accumulation of long-chain acyl CoA esters. Here, we show that acyl CoAs are novel, endogenous activators of reverse-mode NCX1 activity, exhibiting chain length and saturation dependence, with longer chain saturated acyl moieties being the most effective NCX1 activators. These results implicate dietary fat composition as a plausible determinant of IR injury. We further show that acyl CoAs may interact directly with the XIP (exchanger inhibitory peptide) sequence, a known region of anionic lipid modulation, to dynamically regulate NCX1 activity and Ca(2+) homeostasis. Additionally, our findings have broad implications for the coupling of Ca(2+) homeostasis to fat metabolism in a variety of tissues.

We describe a new forest skink species of the genus Sphenomorphus based on specimens from northern Vietnam and from Hainan Island, southern China. The new species is differentiated from the congeners by the combination of the following characters: size small (SVL 35.8–48.8 mm); prefrontals in contact with each other mesially; supralabials seven; primary temporals two; external ear opening present, without lobules, tympanum slightly sunk; midbody scales in 32–34 rows; dorsal scales smooth, paravertebral scales 65–72, not widened; limbs well developed, pentadactyl; 15–19 smooth lamellae under fourth toe; free margins of upper and lower eyelids edged in white; neck, dorsum, and tail base bronze-brown with a discontinuous dark vertebral stripe; upper lateral zone black, interrupted by small light spots from behind the neck. In addition, we provide a review of Vietnamese Sphenomorphus with the first country record of Sphenomorphus mimicus. The generic allocation of Sphenomorphus devorator (allocated t...

A new species of the genus Oligodon Fitzinger, 1826, Oligodon nagao sp. nov., is described on the basis of five specimensoriginating from Lang Son and Cao Bang provinces in northern Vietnam, Guangxi Autonomous Region in southernPeople’s Republic of China, and from Khammouane Province in central Laos PDR. This species differs from other speciesof the region by the combination of 15 or 17 dorsal scale rows at midbody, unforked hemipenes, not spinose but withpapillae, entire cloacal plate, a high number of ventrals, a rather short tail and dorsal pattern made of numerous dark,butterfly-shaped blotches. On the basis of the morphology of its hemipenes, Oligodon nagao sp. nov. belongs to the groupof Oligodon cinereus. This new species is compared with other species of the Indochinese Peninsula and China with 15or 17 dorsal scale rows, especially Oligodon joynsoni (Smith, 1917). An updated list of the Oligodon species of this region is provided.