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101.
The passage of large-sized herpesviral capsids through the nuclear lamina and the inner nuclear membrane to leave the nucleus requires a dissolution of the nuclear lamina. Here, we report on the functions of M50/p35, a beta-herpesviral protein of murine cytomegalovirus. M50/p35 inserts into the inner nuclear membrane and is aggregated by a second viral protein, M53/p38, to form the capsid docking site. M50/p35 recruits the cellular protein kinase C for phosphorylation and dissolution of the nuclear lamina, suggesting that herpesviruses target a critical element of nuclear architecture. 相似文献
102.
Comment on "Emergence of novel color vision in mice engineered to express a human cone photopigment"
Makous W 《Science (New York, N.Y.)》2007,318(5848):196; author reply 196
Jacobs et al. (Reports, 23 March 2007, p. 1723) reported that plasticity in the mammalian visual system permitted the emergence of "a new dimension of sensory experience" in mice genetically engineered to express a human long-wavelength-sensitive cone photopigment. However, neither neural plasticity nor a new dimension of sensory experience is required to explain their results. 相似文献
103.
104.
Aeschlimann M Brixner T Fischer A Kramer C Melchior P Pfeiffer W Schneider C Strüber C Tuchscherer P Voronine DV 《Science (New York, N.Y.)》2011,333(6050):1723-1726
We introduce a spectroscopic method that determines nonlinear quantum mechanical response functions beyond the optical diffraction limit and allows direct imaging of nanoscale coherence. In established coherent two-dimensional (2D) spectroscopy, four-wave-mixing responses are measured using three ingoing waves and one outgoing wave; thus, the method is diffraction-limited in spatial resolution. In coherent 2D nanoscopy, we use four ingoing waves and detect the final state via photoemission electron microscopy, which has 50-nanometer spatial resolution. We recorded local nanospectra from a corrugated silver surface and observed subwavelength 2D line shape variations. Plasmonic phase coherence of localized excitations persisted for about 100 femtoseconds and exhibited coherent beats. The observations are best explained by a model in which coupled oscillators lead to Fano-like resonances in the hybridized dark- and bright-mode response. 相似文献
105.
Space used by animals increases with increasing body size. Energy requirements alone can explain how population density decreases, but not the steep rate at which home range area increases. We present a general mechanistic model that predicts the frequency of interaction, spatial overlap, and loss of resources to neighbors. Extensive empirical evidence supports the model, demonstrating that spatial constraints on defense cause exclusivity of home range use to decrease with increasing body size. In large mammals, over 90% of available resources may be lost to neighbors. Our model offers a general framework to understand animal space use and sociality. 相似文献
106.
Francis Zvomuya Francis J. Larney Walter D. Willms Ryan K. Beck Andrew F. Olson 《Strength and Conditioning Journal》2011,64(4):375-383
Landspraying while drilling (LWD) is an approved disposal method for water-based drilling mud (WBM) systems in western Canada. The mud is applied either on cultivated land, where it is incorporated by cultivation, or on vegetated land where it is not incorporated. This study examined the effects of summer WBM application (0, 15, 20, 40, and 80 m3 · ha?1) on native vegetation properties. Our results indicated that LWD increased bare ground but decreased lichen cover at the 80 m3 · ha?1 rate relative to the untreated control. Nitrogen (N), sulfur (S), and magnesium (Mg) concentrations in aboveground plant tissue increased with increasing LWD rate in samples taken 45 d after WBM application, but these differences disappeared 1 yr after treatment. Increase in tissue concentration of phosphorus (P) with LWD rate, however, was only detected 3 yr after LWD. Nonetheless, these changes in tissue chemistry were not associated with significant changes in biomass yield or species composition. Overall, our results suggest that single WBM applications at rates (≤ 20 m3 · ha?1) commonly used in western Canada, if properly managed, are unlikely to adversely affect native prairie vegetation. 相似文献
107.
Experiments were conducted on olive plants in controlled environments to determine the effect of conidial concentration, leaf age, temperature, continuous and interrupted leaf wetness periods, and relative humidity (RH) during the drier periods that interrupted wet periods, on olive leaf spot (OLS) severity. As inoculum concentration increased from 1·0 × 102 to 2·5 × 105 conidia mL?1, the severity of OLS increased at all five temperatures (5, 10, 15, 20 and 25°C). A simple polynomial model satisfactorily described the relationship between the inoculum concentration at the upper asymptote (maximum number of lesions) and temperature. The results showed that for the three leaf age groups tested (2–4, 6–8 and 10–12 weeks old) OLS severity decreased significantly (P < 0·001) with increasing leaf age at the time of inoculation. Overall, temperature also affected (P < 0·001) OLS severity, with the lesion numbers increasing gradually from 5°C to a maximum at 15°C, and then declining to a minimum at 25°C. When nine leaf wetness periods (0, 6, 12, 18, 24, 36, 48, 72 and 96 h) were tested at the same temperatures, the numbers of lesions increased with increasing leaf wetness period at all temperatures tested. The minimum leaf wetness periods for infection at 5, 10, 15, 20 and 25°C were 18, 12, 12, 12 and 24 h, respectively. The wet periods during early infection processes were interrupted with drying periods (0, 3, 6, 12, 18 and 24 h) at two levels of RH (70 and 100%). The length of drying period had a significant (P < 0·001) effect on disease severity, the effect depending on the RH during the interruption. High RH (100%) resulted in greater disease severity than low RH (70%). A polynomial equation with linear and quadratic terms of temperature, wetness and leaf age was developed to describe the effects of temperature, wetness and leaf age on OLS infection, which could be incorporated as a forecasting component of an integrated system for the control of OLS. 相似文献
108.
Walter E. Riedell 《Journal of plant nutrition》2016,39(14):2115-2125
Ion inclusion or ion exclusion are the two main strategies developed by plants to tolerate saline environments. Shoot sodium (Na+), potassium (K+), and calcium (Ca2+) in four perennial grass species (tall wheatgrass, Nuttall's alkaligrass, creeping foxtail, and switchgrass) treated with nutrient solution salinity levels ranging from 2 to 32 dS m?1 were measured. As the nutrient solution salinity was increased from 2 to 10 dS m?1, tall wheatgrass, creeping foxtail and Nuttall's alkali grass had increased shoot Na+ and decreased Ca2+ concentration while maintaining growth suggesting that these species tolerated these changes in shoot ion concentration. In contrast, switchgrass excluded Na+ from the shoot and maintained K+ and Ca2+ concentrations but suffered dramatic shoot dry weight reduction. Thus, the Na+ exclusion mechanisms present in switchgrass were less efficient in maintaining growth under the 10 dS m?1 nutrient solution treatment than the Na+ inclusion mechanisms used by the other three species. 相似文献
109.
Wang J Chan WG Haut SA Krauss MR Izac RR Hempfling WP 《Journal of agricultural and food chemistry》2005,53(12):4686-4691
A method for the determination of total N-nitroso compounds (NOC) by chemical denitrosation and subsequent chemiluminescence detection of evolved NO is described. Denitrosation was accomplished with CuCl in HCl at 70 degrees C. The detection limit for N-nitrosoproline (NPRO) was 1 pmol. NO formation from NPRO was linear (R(2) = 0.999) from 4 pmol to 2 nmol. Among the possible interfering compounds tested, only S-nitroso compounds contribute any significant interference. This method had several advantages over other similar methods: (1) A commercially available one-piece reaction vessel and a NO analyzer with software were used. (2) NO release occurred rapidly and was easily measured and quantified. (3) Compared to HBr or HI, CuCl was more convenient to work with and safe. (4) CuCl was suitable for samples in aqueous and most organic solvents. The application of this method to food, personal care products, and human body fluids demonstrates its utility. 相似文献
110.
Biochemical characterization of amandin,the major storage protein in almond (Prunus dulcis L.) 总被引:1,自引:0,他引:1
Sathe SK Wolf WJ Roux KH Teuber SS Venkatachalam M Sze-Tao KW 《Journal of agricultural and food chemistry》2002,50(15):4333-4341
The almond major storage protein, amandin, was prepared by column chromatography (amandin-1), cryoprecipitation (amandin-2), and isoelectric precipitation (amandin-3) methods. Amandin is a legumin type protein characterized by a sedimentation value of 14S. Amandin is composed of two major types of polypeptides with estimated molecular weights of 42-46 and 20-22 kDa linked via disulfide bonds. Several additional minor polypeptides were also present in amandin. Amandin is a storage protein with an estimated molecular weight of 427,300 +/- 47,600 Da (n = 7) and a Stokes radius of 65.88 +/- 3.21 A (n = 7). Amandin is not a glycoprotein. Amandin-1, amandin-2, and amandin-3 are antigenically related and have similar biochemical properties. Amandin-3 is more negatively charged than either amandin-1 or amandin-2. Methionine is the first essential limiting amino acid in amandin followed by lysine and threonine. 相似文献