5,296 research outputs found

    Distribution of Caustic-Crossing Intervals for Galactic Binary-Lens Microlensing Events

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    Detection of caustic crossings of binary-lens gravitational microlensing events is important because by detecting them one can obtain useful information both about the lens and source star. In this paper, we compute the distribution of the intervals between two successive caustic crossings, f(tcc)f(t_{\rm cc}), for Galactic bulge binary-lens events to investigate the observational strategy for the optimal detection and resolution of caustic crossings. From this computation, we find that the distribution is highly skewed toward short tcct_{\rm cc} and peaks at tcc1.5t_{\rm cc}\sim 1.5 days. For the maximal detection of caustic crossings, therefore, prompt initiation of followup observations for intensive monitoring of events will be important. We estimate that under the strategy of the current followup observations with a second caustic-crossing preparation time of 2\sim 2 days, the fraction of events with resolvable caustic crossing is 80\sim 80%. We find that if the followup observations can be initiated within 1 day after the first caustic crossing by adopting more aggressive observational strategies, the detection rate can be improved into 90\sim 90%.Comment: total 6 pages, including 5 Figures and no Table, submitted to MNRA

    Rubisco activity and gene expression of tropical tree species under light stress

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    Tropical rain forests contain an ecologically and physiologically diverse range of vegetation and habitats. Sun-acclimated plants can be divided into two groups, shade-tolerant and shade-intolerant, according to the plant’s physiological and genetic responses. Some tropical species have potential capacity for light damage in a shaded environment as well as shade-tolerance to compensate for the impaired light harvesting complex. In particular, ribulose‐1,5‐bisphosphate carboxylase/oxygenase (Rubisco) is regulated by the Calvin cycle, which participated in protein synthesis. Rubisco plays a role in CO2 fixation, which helps supply the energy to regulate Rubisco for ribulose 1,5-bisphosphate (RuBP) reduction. Light intensity is associated with the photosynthetic rate and genetic response to moderate growth environments.Keywords: Gene expression, growth, light intensity, Rubisco activityAfrican Journal of Biotechnology Vol. 12(20), pp. 2764-276

    Interfacial chemical bonding-mediated ionic resistive switching.

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    In this paper, we present a unique resistive switching (RS) mechanism study of Pt/TiO2/Pt cell, one of the most widely studied RS system, by focusing on the role of interfacial bonding at the active TiO2-Pt interface, as opposed to a physico-chemical change within the RS film. This study was enabled by the use of a non-conventional scanning probe-based setup. The nanoscale cell is formed by bringing a Pt/TiO2-coated atomic force microscope tip into contact with a flat substrate coated with Pt. The study reveals that electrical resistance and interfacial bonding status are highly coupled together. An oxygen-mediated chemical bonding at the active interface between TiO2 and Pt is a necessary condition for a non-polar low-resistance state, and a reset switching process disconnects the chemical bonding. Bipolar switching mode did not involve the chemical bonding. The nature of chemical bonding at the TiO2-metal interface is further studied by density functional theory calculations

    OASIS 2: online application for survival analysis 2 with features for the analysis of maximal lifespan and healthspan in aging research

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    Online application for survival analysis (OASIS) has served as a popular and convenient platform for the statistical analysis of various survival data, particularly in the field of aging research. With the recent advances in the fields of aging research that deal with complex survival data, we noticed a need for updates to the current version of OASIS. Here, we report OASIS 2 (http://sbi.postech.ac.kr/oasis2), which provides extended statistical tools for survival data and an enhanced user interface. In particular, OASIS 2 enables the statistical comparison of maximal lifespans, which is potentially useful for determining key factors that limit the lifespan of a population. Furthermore, OASIS 2 provides statistical and graphical tools that compare values in different conditions and times. That feature is useful for comparing age-associated changes in physiological activities, which can be used as indicators of "healthspan." We believe that OASIS 2 will serve as a standard platform for survival analysis with advanced and user-friendly statistical tools for experimental biologists in the field of aging research.1127Ysciescopu

    Effects of mutation at a conserved N-glycosylation site in the bovine retinal cyclic nucleotide-gated ion channel

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    AbstractBovine retinal cyclic nucleotide-gated (CNG) ion channel contains an evolutionary conserved N-glycosylation site in the external loop between the fifth transmembrane segment and the pore-forming region. The effect of tunicamycin treatment and the site-specific mutation suggested that the channel is glycosylated when expressed in Xenopus oocytes. To test the role of glycosylation in this channel, N-glycosylation was abolished by mutation, and the detailed permeation and the gating characteristics of the mutant channel were investigated. The charge contribution turned out to be detectable, although the mutation of the N-glycosylation site did not affect expression and functionality of the CNG channel in oocytes
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