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31.
Man Lung Yeung Jade Lee Lee Teng Lilong Jia Chaoyu Zhang Chengxi Huang Jian-Piao Cai Runhong Zhou Kwok-Hung Chan Hanjun Zhao Lin Zhu Kam-Leung Siu Sin-Yee Fung Susan Yung Tak Mao Chan Kelvin Kai-Wang To Jasper Fuk-Woo Chan Zongwei Cai Susanna Kar Pui Lau Kwok-Yung Yuen 《Cell》2021,184(8):2212-2228.e12
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Biogeochemistry - The coupling between chemical weathering (including silicate, carbonate and pyrite weathering) and physical erosion is of high interest in active mountain belts. Participation of... 相似文献
34.
An Extreme Value Analysis of Pollutant Concentrations in Surface Soils Due to Atmospheric Deposition
Risk assessments often rely on deterministic models using long-term averages or “steady-state” values of input variables. Such models do not provide the information needed to estimate acute exposures. This study uses extreme value theory to examine the frequency and magnitude of daily pollutant concentrations in surface soils predicted at six U.S. locations. Concentrations are predicted using a deposition-leaching model and 50 years of historical precipitation data. A stochastic model also is used to generate 1000 years of precipitation data as modeling inputs for each location. The annual maximum concentrations at each site are fitted to a Gumbel type I distribution to estimate occurrence probability. For soluble pollutants, the predicted concentration varied substantially with precipitation, and the maximum daily concentrations exceeded annual averages by 4 to 8 times. Observed and synthetic precipitation data produced similar results at most study locations, though the synthetic data provided a slightly better fit to the Gumbel type I distribution. The precipitation model allows the generation of representative precipitation data that extend limited historical records. The extreme value analysis facilitates the evaluation of maximum pollutant concentrations, return periods, and other statistics that are important in evaluating acute exposures. 相似文献
35.
Chien-Jung Huang Laurent Schild Edward G. Moczydlowski 《The Journal of general physiology》2012,140(4):435-454
Voltage-gated Na+ channels (NaV channels) are specifically blocked by guanidinium toxins such as tetrodotoxin (TTX) and saxitoxin (STX) with nanomolar to micromolar affinity depending on key amino acid substitutions in the outer vestibule of the channel that vary with NaV gene isoforms. All NaV channels that have been studied exhibit a use-dependent enhancement of TTX/STX affinity when the channel is stimulated with brief repetitive voltage depolarizations from a hyperpolarized starting voltage. Two models have been proposed to explain the mechanism of TTX/STX use dependence: a conformational mechanism and a trapped ion mechanism. In this study, we used selectivity filter mutations (K1237R, K1237A, and K1237H) of the rat muscle NaV1.4 channel that are known to alter ionic selectivity and Ca2+ permeability to test the trapped ion mechanism, which attributes use-dependent enhancement of toxin affinity to electrostatic repulsion between the bound toxin and Ca2+ or Na+ ions trapped inside the channel vestibule in the closed state. Our results indicate that TTX/STX use dependence is not relieved by mutations that enhance Ca2+ permeability, suggesting that ion–toxin repulsion is not the primary factor that determines use dependence. Evidence now favors the idea that TTX/STX use dependence arises from conformational coupling of the voltage sensor domain or domains with residues in the toxin-binding site that are also involved in slow inactivation. 相似文献
36.
Guillermo A. Cecchi Lejian Huang Javeria Ali Hashmi Marwan Baliki María V. Centeno Irina Rish A. Vania Apkarian 《PLoS computational biology》2012,8(10)
While the static magnitude of thermal pain perception has been shown to follow a power-law function of the temperature, its dynamical features have been largely overlooked. Due to the slow temporal experience of pain, multiple studies now show that the time evolution of its magnitude can be captured with continuous online ratings. Here we use such ratings to model quantitatively the temporal dynamics of thermal pain perception. We show that a differential equation captures the details of the temporal evolution in pain ratings in individual subjects for different stimulus pattern complexities, and also demonstrates strong predictive power to infer pain ratings, including readouts based only on brain functional images. 相似文献
37.
Huang , P. C. (California Inst. Technol., Pasadena), and E. F. Paddock . The time and site of the semidominant lethal action of “Wo” in Lycopersicon esculentum. Amer. Jour. Bot. 49(4): 388–393. Illus. 1962.—The semidominant lethal gene, Wo (Woolly), in Lycopersicon esculentum has been investigated with specific attention to its lethal action. The primary lethal action is believed to occur prior to the torpedo stage of embryonic development (approximately 22 days after anthesis). The presumed WoWo embryos cease to grow before any cambial differentiation or organogenesis can be recognized. Their accompanying endospermous cells, however, continue to divide, this resulting in full-sized seeds. The death of these embryos probably occurs near the time of maturation of the seeds (approximately 52 days after anthesis or when the ovulary turns orange-red). The mechanism of death of the embryo apparently lies in and is specific to the embryo; hence, this is a case of autogenously determined embryonic lethality. 相似文献
38.
Background
Plant lipoxygenases (LOXs) have been proposed to form biologically active compounds both during normal developmental stages such as germination or growth as well as during responses to environmental stress such as wounding or pathogen attack. In our previous study, we found that enzyme activity of endogenous 9-LOX in Nicotiana benthamiana was highly induced by agroinfiltration using a tobacco mosaic virus (TMV) based vector system. 相似文献39.
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Following injections of the insoluble portion of disrupted yeast cells ofBlastomyces dermatitidis animals exhibited a biphasic pyrogenic response, a decrease in total serum proteins, and there was no release of interferon. 相似文献