After conjugation in hypotrichous ciliates, a new macronucleus is produced from a copy of the micronucleus. This transformation involves large-scale reorganization of DNA, with conversion of the chromosomal micronuclear genome into short, gene-sized DNA molecules in the macronucleus. To study directly the changes that occur during this process, techniques were developed for synchronous mating of large populations of the hypotrichous ciliate E. crassus. The micronuclear chromosomes are polytenized during the first 20 h of macronuclear development. The polytene chromosomes lack the band-interband organization observed in othe hypotrichs and in the Diptera. Polytenization is followed by transectioning of the chromosomes. DNA was isolated at various times of macronuclear development and the average MW of the DNA decreases at the time of chromosome transectioning. A small size group of macronuclear DNA molecules (450-550 base pairs) is excised from the chromosomal DNA .apprx. 10 h later in macronuclear development.

Fine particulate matter (PM2.5) is a criteria pollutant. Its sensitivity to meteorology implies its distribution will likely change with climate shifts. Limited availability of global climate models with full chemistry complicates efforts to assess rigorously the uncertainties in the PM2.5 response to a warming climate. We evaluate the potential for PM2.5 distributions in a chemistry-climate model under current-day and warmer climate conditions over the Northeastern United States to be represented by a Synthetic Aerosol tracer (SAt). The SAt implemented into the Geophysical Fluid Dynamics Laboratory chemistry-climate model (AM3) follows the protocol of a recent multimodel community effort (HTAP), with CO emissions, 25-day chemical lifetime, and wet deposition rate of sulfate. Over the Northeastern United States, the summer daily time series of SAt correlates strongly with that of PM2.5, with similar cumulative density functions under both present and future climate conditions. With a linear regression model derived from PM2.5 and SAt in the current-day simulation, we reconstruct both the current-day and future PM2.5 daily time series from the simulated SAt. This reconstruction captures the summer mean PM2.5, the incidence of days above the 24-h mean PM2.5 NAAQS, and PM2.5 responses to climate change. This reconstruction also works over other polluted Northern Hemispheric regions and in spring. Our proof-of-concept study demonstrates that simple tracers can be developed to mimic PM2.5, including its response to climate change, as an easy-to-implement and low-cost addition to physical climate models that should help air quality managers to reap the benefits of climate models that have no chemistry. Citation: Fang, Y., A. M. Fiore, J.-F. Lamarque, L. W. Horowitz, and M. Lin (2013), Using synthetic tracers as a proxy for summertime PM2.5 air quality over the Northeastern United States in physical climate models, Geophys. Res. Lett., 40, 755-760, doi:10.1002/grl.50162.

In addition to its well-established role in plant development, the hormone cytokinin regulates plant responses to biotic and abiotic stresses. It was previously shown that cytokinin signaling acts negatively upon drought and osmotic stress tolerance and that gain-of-function of the cytokinin response regulator ARR1 causes osmotic stress hypersensitivity. Here we show that increased ARR1 action increases tolerance to heat shock and that this is correlated with increased accumulation of the heat shock proteins Hsp17.6 and Hsp70. These results show that the heat shock tolerance of plants can be elevated by increasing the expression of a cytokinin response activator.

Aims. We study the stellar and dust properties of a well-defined sample of local elliptical galaxies to investigate the relationship between host galaxy properties and nuclear activity.

In this work, the microalloying effect on glass-forming ability (GFA) has been investigated from the structural aspect, by performing synchrotron radiation X-ray diffraction and absorption measurements coupled with simulations in the NiNbZr ternary system. By sorting out the preferred Voronoi clusters, we propose a new structural parameter which counts the fraction of the five-connected shell atoms in clusters and find it is strongly associated with the GFA. In particular, this structural parameter has the highest value in a composition where the best GFA is achieved. The present work provides an in-depth understanding of microalloying-induced high GFAs in multicomponent alloys. (C) 2016 Elsevier Ltd. All rights reserved.

Tunable symmetry breaking plays a crucial role for the manipulation of topological phases of quantum matter. Here, through combined high-pressure magnetotransport measurements, Raman spectroscopy, and x-ray diffraction, we demonstrate a pressure-induced topological phase transition in nodal-line semimetal ZrSiS. Symmetry analysis and first-principles calculations suggest that this pressure-induced topological phase transition may be attributed to weak lattice distortions by nonhydrostatic compression, which breaks some crystal symmetries, such as the mirror and inversion symmetries. This finding provides some experimental evidence for crystal symmetry protection for the topological semimetal state, which is at the heart of topological relativistic fermion physics.

Graphite-bearing peridotites, pyroxenites and eclogite xenoliths from the Kaapvaal craton of southern Africa and the Siberian craton, Russia, have been studied with the aim of: 1) better characterising the abundance and distribution of elemental carbon in the shallow continental lithospheric mantle; (2) determining the isotopic composition of the graphite; (3) testing for significant metastability of graphite in mantle rocks using mineral thermobarometry. Graphite crystals in peridotie, pyroxenite and eclogite xenoliths have X-ray diffraction patterns and Raman spectra characteristic of highly crystalline graphite of high-temperature origin and are interpreted to have crystallised within the mantle. Thermobarometry on the graphite-peridotite assemblages using a variety of element partitions and formulations yield estimated equilibration conditions that plot at lower temperatures and pressures than diamondiferous assemblages. Moreover, estimated pressures and temperatures for the graphite-peridotites fall almost exclusively within the experimentally determined graphite stability field and thus we find no evidence for substantial graphite metastability. The carbon isotopic composition of graphite in peridotites from this and other studies varies from deltaC-13PDB=-12.3 to -3.8 parts per thousand with a mean of -6.7 parts per thousand, a = 2.1 (n = 22) and a mode between -7 and -6 parts per thousand. This mean is within one standard deviation of the -4 parts per thousand mean displayed by diamonds from peridotite xenoliths, and is identical to that of diamonds containing peridotite-suite inclusions. The carbon isotope range of graphite and diamonds in peridotites is more restricted than that observed for either phase in eclogites or pyroxenites. The isotopic range displayed by peridotite-suite graphite and diamond encompasses the carbon isotope range observed in mid-ocean-ridge-basalt (MORB) glasses and ocean-island basalts (OIB). Similarity between the isotopic compositions of carbon associated with cratonic peridotites and the carbon (as CO2) in oceanic magmas (MORB/OIB) indicates that the source of the fluids that deposited carbon, as graphite or diamond, in cratonic peridotites lies within the convecting mantle, below the lithosphere. Textural observations provide evidence that some of graphite in cratonic peridotites is of sub-solidus metasomatic origin, probably deposited from a cooling C - H - O fluid phase permeating the lithosphere along fractures. Macrocrystalline graphite of primary appearance has not been found in mantle xenoliths from kimberlitic or basaltic rocks erupted away from cratonic areas. Hence, graphite in mantle-derived xenoliths appears to be restricted to Archaean cratons and occurs exclusively in low-temperature, coarse peridotites thought to be characteristic of the lithospheric mantle. The tectonic association of graphite within the mantle is very similar to that of diamond. It is unlikely that this restricted occurrence is due solely to unique conditions of oxygen fugacity in the cratonic lithospheric mantle because some peridotite xenoliths from off-craton localities are as reduced as those from within cratons. Radiogenic isotope systematics of peridotite-suite diamond inclusions suggest that diamond crystallisation was not directly related to the melting events that formed lithospheric peridotites.

High-pressure angle-dispersive x-ray diffraction measurements have been performed on bulk and nanocrystalline cubic CeO2 with mean sizes of 4.7 and 5.6 nm. It is found that the compressibility of the nanocrystals is lower than the bulk when a threshold pressure is reached. This critical pressure is found to be 10 GPa for 4.7 nm and 16 GPa for 5.6 nm CeO2 nanocubes. The particle size dependence of the threshold pressure for the hardening of CeO2 nanoparticles is quite unusual. First-principles electronic calculations show that the increased bulk modulus of the nanocrystal is due to the strengthening of the surface Ce-O bonds resulting in a much larger shear modulus than in the bulk and consequently hardening the shell surface.

Episodic ejection of plasma blobs has been observed in many black hole systems. While steady, continuous jets are believed to be associated with large-scale open magnetic fields, what causes the episodic ejection of blobs remains unclear. Here by analogy with the coronal mass ejection on the Sun, we propose a magnetohydrodynamical model for episodic ejections from black holes associated with the closed magnetic fields in an accretion flow. Shear and turbulence of the accretion flow deform the field and result in the formation of a flux rope in the disc corona. Energy and helicity are accumulated and stored until a threshold is reached. The system then loses its equilibrium and the flux rope is thrust outward by the magnetic compression force in a catastrophic way. Our calculations show that for parameters appropriate for the black hole in our Galactic centre, the plasmoid can attain relativistic speeds in about 35 min.

We investigate the origin of the X-ray emission in low-luminosity active galactic nuclei (LLAGNs). Yuan and Cui predicted that the X-ray emission should originate from jets rather than an advection-dominated accretion flow (ADAF) when the X-ray luminosity L-X of the source is below a critical value of L-X,L-crit approximate to 10(-6)L(Edd). This prediction implies that the X-ray spectrum in such sources should be fitted by jets rather than ADAFs. Furthermore, below L-X,L-crit the correlation between radio (L-R) and X-ray (L-X) luminosities and the black hole mass (M)-the so-called fundamental plane of black hole activity-should deviate from the general correlation obtained by Merloni et al. and become steeper. The Merloni et al. correlation is described by logL(R) = 0.6logL(X) + 0.78logM + 7.33, while the predicted correlation is logL(R) = 1.23logL(X) + 0.25logM-13.45. We collect data from the literature to check the validity of these two expectations. We find that among the 16 LLAGNs with good X-ray and radio spectra, 13 are consistent with the Yuan and Cui prediction. For the 22 LLAGNs with L-X < L-X,L-crit, the fundamental plane correlation is described by logL(R) 1.22logL(X)+ 0.23logM-12.46, also in excellent agreement with the prediction.