Однородные и неоднородные ширины линий в оптических спектрах кристалла Y-=SUB=-2-=/SUB=-SiO-=SUB=-5-=/SUB=- : -=SUP=-171-=/SUP=-Yb-=SUP=-3+-=/SUP=-

Rare earth ions are actively investigated as optically addressable spin systems for quantum technologies thanks to their long optical and spin coherence lifetimes. 171Yb3+, which has 1/2 electron and nuclear spins, recently raised interest for its simple hyperfine structure that moreover can result in long coherence lifetimes at zero magnetic field, an unusual property for paramagnetic rare earth ions. Here, we report on the optical inhomogeneous and homogeneous linewidths in 171Yb3+:Y2SiO5 (site 2) for different doping concentrations. While inhomogeneous linewidth is not correlated to 171Yb3+ concentration, the homogeneous one strongly decreases between 10 and 2 ppm doping level, reaching 255 Hz at 3 K. This is attributed to a slowing down of 171Yb3+ ground state spin flip-flops.

Verbs of deception, point of view and polarity

The Dutch and German verbs wijsmaken/weismachen 'make wise' have an idiomatic interpretation as verbs of deception 'to fool'. As such, they have the unusual property of being contrafactive (presupposing the falsity of their complement). With second person or generic pronoun subjects, under negation and with future orientation, they are used to express disbelief on the part of the entity denoted by the indirect object. A corpus study shows this secondary use to be especially prominent in Dutch. It depends on the availability of the point of view of experiencer and is most common with first person dative objects.

Correlated copying in a hidden network model

We introduce the concept of a hidden network model -- a generative two-layer network in which an observed network evolves according to the structure of an underlying hidden layer. We apply the concept to a simple, analytically tractable model of correlated node copying. In contrast to models where nodes are copied uniformly at random, we consider the case in which the set of copied nodes is biased by the underlying hidden network. In the context of a social network, this copied set may be thought of as an individual's inner social circle, whereas the remaining nodes are part of the wider social circle. Correlated copying results in a stretched-exponential degree distribution, suppressing the power-law tail observed in uniform copying, generates networks with significant clustering, and, in contrast to uniform copying, exhibits the unusual property that the number of cliques of size n grows independently of n. We suggest that hidden network models offer an alternative family of null models for network comparison, and may offer a useful conceptual framework for understanding network heterogeneity.

PbS biomineralization using cysteine: Bacillus cereus and the sulfur rush

Bacillus sp. Abq, belonging to Bacillus cereus sensu lato, was isolated from an aquifer in New Mexico, USA and phylogenetically classified. The isolate possesses the unusual property of precipitating Pb(II) by using cysteine, which is degraded intracellularly to hydrogen sulfide (H2S). H2S is then exported to the extracellular environment to react with Pb(II), yielding PbS (galena). Biochemical and growth tests showed that other sulfur sources tested (sulfate, thiosulfate, and methionine) were not reduced to hydrogen sulfide. Using equimolar concentration of cysteine, 1 mM of soluble Pb(II) was removed from Lysogeny Broth (LB) medium within 120 h of aerobic incubation forming black, solid PbS, with a removal rate of 2.03 µg L−1 h−1 (∼8.7 µM L−1 h−1). The mineralogy of biogenic PbS was characterized and confirmed by XRD, HRTEM, and EDX. Electron microscopy and electron diffraction identified crystalline PbS nanoparticles with a diameter <10 nm, localized in the extracellular matrix and on the surface of the cells. This is the first study demonstrating the use of cysteine in Pb(II) precipitation as insoluble PbS and it may pave the way to PbS recovery from secondary resources, such as Pb-laden industrial effluents.

Gigantic work function in layered AgF2

The calculated work function of a powerful oxidizer, AgF2, is 7.76 eV, thus exceeds even that of fluorinated diamond. This unusual property could be used for fabrication of novel junction electronic devices showing ‘‘broken-gap’’ type band alignment.

MNRR1, a Biorganellar Regulator of Mitochondria

The central role of energy metabolism in cellular activities is becoming widely recognized. However, there are many gaps in our knowledge of the mechanisms by which mitochondria evaluate their status and call upon the nucleus to make adjustments. Recently, a protein family consisting of twin CX9C proteins has been shown to play a role in human pathophysiology. We focus here on two family members, the isoforms CHCHD2 (renamed MNRR1) and CHCHD10. The better studied isoform, MNRR1, has the unusual property of functioning in both the mitochondria and the nucleus and of having a different function in each. In the mitochondria, it functions by binding to cytochromecoxidase (COX), which stimulates respiration. Its binding to COX is promoted by tyrosine-99 phosphorylation, carried out by ABL2 kinase (ARG). In the nucleus, MNRR1 binds to a novel promoter element inCOX4I2and itself, increasing transcription at 4% oxygen. We discuss mutations in both MNRR1 and CHCHD10 found in a number of chronic, mostly neurodegenerative, diseases. Finally, we propose a model of a graded response to hypoxic and oxidative stresses, mediated under different oxygen tensions by CHCHD10, MNRR1, and HIF1, which operate at intermediate and very low oxygen concentrations, respectively.

Lateral chirality-sorting optical forces

The transverse component of the spin angular momentum of evanescent waves gives rise to lateral optical forces on chiral particles, which have the unusual property of acting in a direction in which there is neither a field gradient nor wave propagation. Because their direction and strength depends on the chiral polarizability of the particle, they act as chirality-sorting and may offer a mechanism for passive chirality spectroscopy. The absolute strength of the forces also substantially exceeds that of other recently predicted sideways optical forces.

Symmetric Time-Reversible Flows with a Strange Attractor

A symmetric chaotic flow is time-reversible if the equations governing the flow are unchanged under the transformation t → -t except for a change in sign of one or more of the state space variables. The most obvious solution is symmetric and the same in both forward and reversed time and thus cannot be dissipative. However, it is possible for the symmetry of the solution to be broken, resulting in an attractor in forward time and a symmetric repellor in reversed time. This paper describes the simplest three-dimensional examples of such systems with polynomial nonlinearities and a strange (chaotic) attractor. Some of these systems have the unusual property of allowing the strange attractor to coexist with a set of nested symmetric invariant tori.