The consistency test on the cosmic evolution

We propose a new and robust method to test the consistency of the cosmic evolution given by a cosmological model. It is realized by comparing the combined quantity r_d^CMB/D_V^SN, which is derived from the comoving sound horizon r_d from cosmic microwave background (CMB) measurements and the effective distance D_V derived from low-redshift Type-Ia supernovae (SNe Ia) data, with direct and independent r_d/D_V obtained by baryon acoustic oscillation (BAO) measurements at median redshifts. We apply this test method for the Lambda-CDM and wCDM models, and investigate the consistency of the derived value of r_d/D_V from Planck 2015 and the SN Ia data sets of Union2.1 and JLA (z<1.5), and the r_d/D_V directly given by BAO data from six-degree-field galaxy survey (6dFGS), Sloan Digital Sky Survey Data Release 7 Main Galaxy Survey (SDSS-DR7 MGS), DR11 of SDSS-III, WiggleZ and Ly-alpha forecast surveys from Baryon Oscillation Spectroscopic Data (BOSS) DR-11 over 0.1<z<2.36. We find that r_d^CMB/D_V^SN for both non-flat Lambda-CDM and flat wCDM models with Union2.1 and JLA data are well consistent with the BAO and CMB measurements within 1-sigma CL. Future surveys will further tight up the constraints significantly, and provide stronger test on the consistency.Comment: 11 pages, 5 figures, 4 tables. Version accepted by PR

Multifunctional Bracts in the Dove Tree Davidia involucrata (Nyssaceae:Cornales)

Although there has been much experimental work on floral traits that are under selection from mutualists and antagonists, selection by abiotic environmental factors on flowers has been largely ignored. Here we test whether pollen susceptibility to rain damage could have played a role in the evolution of the reproductive architecture of Davidia involucrata, an endemic in the mountains of western China. Flowers in this tree species lack a perianth and are arranged in capitula surrounded by large (up to 10 cm#5 cm) bracts that at anthesis turn from green to white, losing their photosynthetic capability. Flowers are nectarless, and pollen grains are presented on the recurved anther walls for 5–7 days. Flower visitors, and likely pollinators, were mainly pollen-collecting bees from the genera Apis, Xylocopa, Halictus, and Lasioglossum. Capitula with natural or white paper bracts attracted significantly more bees per hour than capitula that had their bracts removed or replaced by green paper. Experimental immersion of pollen grains in water resulted in rapid loss of viability, and capitula with bracts lost less pollen to rain than did capitula that had their bracts removed, suggesting that the bracts protect the pollen from rain damage as well as attracting pollinators

Analytic initial relative orbit solution for angles-only space rendezvous using hybrid dynamics method

A closed-form solution to the angles-only initial relative orbit determination (IROD) problem for space rendezvous with non-cooperated target is developed, where a method of hybrid dynamics with the concept of virtual formation is introduced to analytically solve the problem. Emphasis is placed on developing the solution based on hybrid dynamics (i.e., Clohessy-Wiltshire equations and two-body dynamics), obtaining formation geometries that produce relative orbit state observability, and deriving the approximate analytic error covariance for the IROD solution. A standard Monte Carlo simulation system based on two-body dynamics is used to verify the feasibility and evaluate the performance proposed algorithms. The sensitivity of the solution accuracy to the formation geometry, observation numbers is presented and discussed

5-Bromo-2-meth­oxy-4-{[(4-meth­oxy­phen­yl)imino]­meth­yl}phenol monohydrate

The crystal structure of the title compound, C15H14BrNO3·H2O, has a trans configuration about the central C=N double bond. An intra­molecular O—H⋯O hydrogen bond occurs in the main mol­ecule. The crystal packing is stabilized by strong O—H⋯O and O—H⋯N hydrogen bonds

Epigenetic Control of Circadian Clock Operation during Development

The molecular players of circadian clock oscillation have been identified and extensively characterized. The epigenetic mechanisms behind the circadian gene expression control has also been recently studied, although there are still details to be illucidated. In this review, we briefly summarize the current understanding of the mammalian clock. We also provide evidence for the lack of circadian oscillation in particular cell types. As the circadian clock has intimate interaction with the various cellular functions in different type of cells, it must have plasticity and specicity in its operation within different epigenetic environments. The lack of circadian oscillation in certain cells provide an unique opportunity to study the required epigenetic environment in the cell that permit circadian oscillation and to idenfify key influencing factors for proper clock function. How epigenetic mechansims, including DNA methylaiton and chromatin modifications, participate in control of clock oscillation still awaits future studies at the genomic scale

Highly sensitive magnetic properties and large linear magnetoresistance in antiferromagnetic CrxSe(0.875\lex\le1)single crystals

CrxSe (x\le1) is a class of quasi-layered binary compounds with potential applications in spintronics due to its intriguing antiferromagnetic properties. In this work, CrxSe single crystals with high Cr content (x=0.87, 0.91 and 0.95) were grown, and their magnetic and transport properties were investigated in detail. It is found that with small increase of Cr content, the N\'eel temperature (TN) of the samples can dramatically increase from 147 K to 257 K, accompanied with obvious changes in the magnetic anisotropy and hysteresis. The phenomena of field-induced spin-flop transitions were unveiled in these alloys, indicating their comparatively low anisotropy. The magnetoresistance (MR) of the three compounds showed positive dependence at low temperatures and particularly, non-saturated linear positive MR was observed in Cr0.91Se and Cr0.95Se, with a large value of 16.2% achieved in Cr0.91Se (10K, 9T). The calculated Fermi surface and MR showed that the quasi-linear MR is a product of carrier compensation. Our work revealed highly sensitive magnetic and transport properties in the Cr-Se compounds, which can lay foundation when constructing further antiferromagnetic spintronic devices based on them