Regulation and accumulation of secondary metabolites in plant-fungus symbiotic system

Plants have evolved adaptive strategies to mutualistic microbes penetration for both mycorrhizal fungi and endophytic fungi. Subsequently, an array of host plant defense responses and signal transduction is generated. A group of secondary metabolites are accumulated inducibly or enhanced constitutively in plant tissues during the process. Symbiotic fungi usually perform compatible and friendly interactions with host plants, which contribute to growth promotion and secondary metabolites accumulation simultaneously, such as alkaloids and terpenoid with pharmacological characteristics. Especially, some secondary metabolites derived from root exudation act as signal molecules, which induce the spore germination and hypha branching in mycorrhizal fungi. However, the precise mechanisms in some cases remain unclear so far and need to be further investigated. Above exciting and interesting results shed light on our understanding of the mystery of fungal elicitation of secondary metabolitesaccumulation in plant kingdom. Therefore a deeper insight in mutualistic symbiosis is of great importance for biological applications: (1) the plant/microbial co-culture system in vitro may be perfectly useful to guide the cultivation of medicinal plants for obtaining high level of bioactive compounds; (2) manipulating plant released signal molecules and isoprenoid metabolism will be effective to optimize and improve the function of mycorrhizae in forestry, agriculture and horticulture

Factors related to children's caries: a structural equation modeling approach

published_or_final_versio

General theory of decoy-state quantum cryptography with source errors

The existing theory of decoy-state quantum cryptography assumes the exact control of each states from Alice's source. Such exact control is impossible in practice. We develop the theory of decoy-state method so that it is unconditionally secure even there are state errors of sources, if the range of a few parameters in the states are known. This theory simplifies the practical implementation of the decoy-state quantum key distribution because the unconditional security can be achieved with a slightly shortened final key, even though the small errors of pulses are not corrected.Comment: Our results can be used securely for any source of diagonal states, including the Plug-&-Play protocol with whatever error pattern, if we know the ranges of errors of a few parameter

Zb(10610)±Z_b(10610)^\pm and Zb(10650)±Z_b(10650)^\pm as the B∗BˉB^*\bar{B} and B∗Bˉ∗B^*\bar{B}^{*} molecular states

In the framework of the one-boson-exchange model, we have studied the interaction of the $B^*\bar{B}$ and $B^*\bar{B}^{*}$ system. After considering the S-wave and D-wave mixing, we notice that both $Z_b(10610)^\pm$ and $Z_b(10650)^\pm$ can be interpreted as the $B^*\bar{B}$ and $B^*\bar{B}^{*}$ molecular states quite naturally. Within the same framework, there also exist several molecular charmonia including X(3872) and several other molecular bottomonia, which are the partners of $Z_b(10610)$ and $Z_b(10650)$. The long-range one-pion-exchange force alone is strong enough to form these loosely bound molecular states, which ensures the numerical results quite model-independent and robust.Comment: 11 pages, 6 table

Meta-analysis: The Effect of Muscle Strength Training on Walking Ability of Patients with Parkinson's Disease

Objective: This Meta-analysis was aimed to systematically studying the effects of muscle strength training on the walking ability like balance ability, mobility ability of Parkinson's disease patients and then provide useful theoretical reference to further researches on exercise treatments on Parkinson’s disease by retrieving and collecting articles about muscle strength training. Methods This literature review was finally determined on searching PubMed, Elsevier, Web of science, China Journal Full-text Database (CNKI), WanFang Data and other Chinese and foreign databases and combined with manual search. The limit of the search time was from the date when the literature was recorded to 2019. A comprehensive collection of randomly controlled trials of muscle strength training on the walking ability of Parkinson's patients was done. Researchers used the Cochrance risk assessment tool to evaluate the methodological quality of the selected articles, and the ReMan 5.3.5 software to statistically process the obtained data. Results A total of 13 RCTs and 627 samples were included in this study. Meta-analysis of BBS balance scale show that MD=4.67 (95%CI, I2=97%, P=0.52) between muscle strength training group and non-exercise intervention group; MD=-2.67 between muscle strength training group and exercise intervention control group (95%CI, I2=7%, P<0.00001); TUGT Meta-analysis show that MD=-1.06 (95%CI, I2=75%, P=0.10) between muscle strength training group and non-exercise intervention group; MD=0.09 (95%CI, I2=0%, P=0.31) between the muscle strength training group and the control group with exercise intervention; 10MWT Meta-analysis show MD=-0.28 (95%CI), I2=98%, P<0.29) between the muscle strength training group and the control group with exercise intervention; Stride length Meta-analysis show MD=-1.85 (95%CI, I2=68%, P=0.63) between the muscle strength training group and the control group without exercise intervention; MD=-1.75 (95%CI, I2=32%, P=0.56) between the muscle strength training group and the control group with exercise intervention; MD=-1.75 (95%CI, I2=32%, P=0.56). Meta-analysis of stride speed show MD=-0.02 (95%CI, I2=0%, P=0.46) between muscle strength training group and control group without exercise intervention; MD=-0.03 (95%CI, I2=35%, P=0.52) between the muscle strength training group and control group with exercise intervention. Conclusion Muscle strength training can significantly improve the balance ability, mobility, and walking ability of Parkinson's disease patients, but it has no significant benefits on improving stride length and walking speed

A Close Binary Star Resolved from Occultation by 87 Sylvia

The star BD+29 1748 was resolved to be a close binary from its occultation by the asteroid 87 Sylvia on 2006 December 18 UT. Four telescopes were used to observe this event at two sites separated by some 80 km apart. Two flux drops were observed at one site, whereas only one flux drop was detected at the other. From the long-term variation of Sylvia, we inferred the probable shape of the shadow during the occultation, and this in turn constrains the binary parameters: the two components of BD+29 1748 have a projected separation of 0.097" to 0.110" on the sky with a position angle 104 deg to 107 deg. The asteroid was clearly resolved with a size scale ranging from 130 to 290 km, as projected onto the occultation direction. No occultation was detected for either of the two known moonlets of 87 Sylvia.Comment: 12 pages, 4 figures, 2 tables; submitted to the PAS

Effects of ac-field amplitude on the dielectric susceptibility of relaxors

The thermally activated flips of the local spontaneous polarization in relaxors were simulated to investigate the effects of the applied-ac-field amplitude on the dielectric susceptibility. It was observed that the susceptibility increases with increasing the amplitude at low temperatures. At high temperatures, the susceptibility experiences a plateau and then drops. The maximum in the temperature dependence of susceptibility shifts to lower temperatures when the amplitude increases. A similarity was found between the effects of the amplitude and frequency on the susceptibility.Comment: 8 pages, 7 figures, Phys. Rev. B (in July 1st

On the Optimum Long Baseline for the Next Generation Neutrino Oscillation Experiments

For high energy long baseline neutrino oscillation experiments, we propose a Figure of Merit criterion to compare the statistical quality of experiments at various oscillation distances under the condition of identical detectors and a given neutrino beam. We take into account all possible experimental errors under general consideration. In this way the Figure of Merit is closely related to the usual statistical criterion of number of sigmas. We use a realistic neutrino beam for an entry level neutrino factory and a possible superbeam from a meson source and a 100 kt detector for the calculation. We considered in detail four oscillation distances, 300 km, 700 km, 2100 km and 3000 km, in the neutrino energy range of 0.5-20 GeV for a 20 GeV entry level neutrino factory and a 50 GeV superbeam. We found that the very long baselines of 2100 km and 3000 km are preferred for the neutrino factory according to the figure of merit criterion. Our results also show that, for a neutrino factory, lower primary muon energies such as 20 GeV are preferred rather than higher ones such as 30 or 50 GeV. For the superbeam, the combination of a long baseline such as 300 km and a very long baseline like 2100 km will form a complete measurement of the oscillation parameters besides the CP phase. To measure the CP phase in a superbeam, a larger detector (a factor 3 beyond what is considered in this article) and/or a higher intensity beam will be needed to put some significant constraints on the size of the CP angle.Comment: 21 LaTeX pages, 13 PS figures, typos corrected, references adde

Rapid Surface Oxidation as a Source of Surface Degradation Factor for Bi2Se3

Bi2Se3 is a topological insulator with metallic surface states residing in a large bulk bandgap. It is believed that Bi2Se3 gets additional n-type doping after exposure to atmosphere, thereby reducing the relative contribution of surface states in total conductivity. In this letter, transport measurements on Bi2Se3 nanoribbons provide additional evidence of such environmental doping process. Systematic surface composition analyses by X-ray photoelectron spectroscopy reveal fast formation and continuous growth of native oxide on Bi2Se3 under ambient conditions. In addition to n-type doping at the surface, such surface oxidation is likely the material origin of the degradation of topological surface states. Appropriate surface passivation or encapsulation may be required to probe topological surface states of Bi2Se3 by transport measurements