A Stationary, Mixing and Perturbative Counterexample to the 0-1-law for Random Walk in Random Environment in Two Dimensions

We construct a two-dimensional counterexample of a random walk in random environment (RWRE). The environment is stationary, mixing and perturbative, and the corresponding RWRE has non-trivial probability to wander off to the upper right. This is in contrast to the 0-1-law that holds for i.i.d.\ environments

Could the library be dismantled/role of unique holdings in modern times

I have been asked by administration, how much of our collection could go into storage. They optimistically hoping for a room or two for faculty/staff offices, as some buildings need renovation or need to be closed due to safety issues. Clearly, much of the population believes that all/most library materials are available on-line – free. I will present the results of our survey’s of material held and available on-line and space “freed” thanks to archiving. How little space is freed

The linear rms-flux relation in an Ultraluminous X-ray Source

We report the first detection of a linear correlation between rms variability amplitude and flux in the Ultraluminous X-ray source NGC 5408 X-1. The rms-flux relation has previously been observed in several Galactic black hole X-ray binaries (BHBs), several Active Galactic Nuclei (AGN) and at least one neutron star X-ray binary. This result supports the hypothesis that a linear rms-flux relation is common to all luminous black hole accretion and perhaps even a fundamental property of accretion flows about compact objects. We also show for the first time the cross-spectral properties of the variability of this ULX, comparing variations below and above 1 keV. The coherence and time delays are poorly constrained but consistent with high coherence between the two bands, over most of the observable frequency range, and a significant time delay (with hard leading soft variations). The magnitude and frequency dependence of the lags are broadly consistent with those commonly observed in BHBs, but the direction of the lag is reversed. These results indicate that ULX variability studies, using long X-ray observations, hold great promise for constraining the processes driving ULXs behaviour, and the position of ULXs in the scheme of black hole accretion from BHBs to AGN.Comment: 4 Pages, 3 figures, accepted for publication by MNRAS

Quasiparticle GWGW band structures and Fermi surfaces of bulk and monolayer NbS2_2

In this work we employ the $GW$ approximation in the framework of the SternheimerGW method to investigate the effects of many-body corrections to the band structures and Fermi surfaces of bulk and monolayer NbS$_2$. For the bulk system, we find that the inclusion of these many-body effects leads to important changes in the band structure, especially in the low-energy regime around the Fermi level, and that our calculations are in good agreement with recent ARPES measurements. In the case of a free-standing monolayer NbS$_2$, we observe a strong increase of the screened Coulomb interaction and the quasiparticle corrections as compared to bulk. In this case we also perform calculations to include the effect of screening by a substrate. We report in detail the results of our convergence tests and computational parameters, to serve as a solid basis for future studies.Comment: 15 pages, 18 figure

Pre-entry advertising, entry deterrence and multi-informational signaling

Advertising is commonly regarded as a strategic tool to increase demand and steal business from competitors. The present work studies the competitive effects of advertising in a two-period game with incomplete information about the opponent's cost structure. Bagwell and Ramey (1988) showed that deterring entry is possible by signaling lower costs even if the post-entry game is independent of the pre-entry advertising decision. Assuming that pre-entry advertising by an entrant affects the post-entry game, then the incumbent is forced to do more than in the Bagwell/Ramey case to deter entry; he needs to distort costs downwards more extensively. On the other hand, introductory advertising does not facilitate entry if the entrant learns from the signal that competition with the incumbent is unprofitable. In this case, the entrant abstains from entry after performing introductory advertisng. Furthermore, if the incumbent has private information on cost and advertising effectiveness, then he can deter entry by acting as if he had lower production costs and a better advertising effectiveness. In this scenario, entry deterrence is associated with overinvestment in advertising but not with limit pricing, which is a new prediction. The use of multi-informational signals, i.e. pooled information on more than one type of private information transferred by one signal, is methodologically a new development of the classical signaling game.advertising, entry deterrence, advertising effectiveness, pre-entry advertising, signaling

Chemical investigation of light induced DNA bipyrimidine damage and repair

In all organisms, genetic information is stored in DNA and RNA. Both of these macromolecules are damaged by many exogenous and endogenous events, with UV irradiation being one of the major sources of damage. The major photolesions formed are the cyclobutane pyrimidine dimers (CPD), pyrimidine–pyrimidone-(6-4)-photoproducts, Dewar valence isomers and, for dehydrated spore DNA, 5-(a-thyminyl)-5,6-dihydrothymine (SP). In order to be able to investigate how nature’s repair and tolerance mechanisms protect the integrity of genetic information, oligonucleotides containing sequence and site-specific UV lesions are essential. This tutorial review provides an overview of synthetic procedures by which these oligonucleotides can be generated, either through phosphoramidite chemistry or direct irradiation of DNA. Moreover, a brief summary on their usage in analysing repair and tolerance processes as well as their biological effects is provided

Reducing air pollution from urban passenger transport : a framework for policy analysis

This paper develops a simple framework to analyze various pollution control strategies that have been used or are proposed in the urban passenger transport sector. The context is the declining quality of air in urban areas, which is among the serious problems associated with the rapid motorization of societies the world over. The paper examines the point of impact of different policy levers and provides a categorization of different instruments that should assist policy makers when choosing between them. A distinguishing feature of this framework is its explicit recognition of behavioral incentives, in particular, the fact that offsetting changes in consumer behavior can often undermine the original intent of particular policies. The paper is organized as follows. Section II presents the basic framework we have used to examine transport emissions. Section III reviews pollutant characteristics and their impact. The resulting policy choices are discussed in more detail in section IV. Several urban transport projects supported by the World Bank are then reviewed in section VI, and section V concludes the report.Montreal Protocol,Environmental Economics&Policies,Air Quality&Clean Air,Roads&Highways,Public Health Promotion,Roads&Highways,Urban Transport,Transport and Environment,Environmental Economics&Policies,Airports and Air Services

Absence of superconductivity in iron polyhydrides at high pressures

Recently, C. M. Pépin et al. [Science 357, 382 (2017)] reported the formation of several new iron polyhydrides FeHx at pressures in the megabar range and spotted FeH5, which forms above 130 GPa, as a potential high-Tc superconductor because of an alleged layer of dense metallic hydrogen. Shortly after, two studies by A. Majumdar et al. [Phys. Rev. B 96, 201107 (2017)] and A. G. Kvashnin et al. [J. Phys. Chem. C 122, 4731 (2018)] based on ab initio Migdal-Eliashberg theory seemed to independently confirm such a conjecture. We conversely find, on the same theoretical-numerical basis, that neither FeH5 nor its precursor, FeH3, shows any conventional superconductivity and explain why this is the case. We also show that superconductivity may be attained by transition-metal polyhydrides in the FeH3 structure type by adding more electrons to partially fill one of the Fe-H hybrid bands (as, e.g., in NiH3). Critical temperatures, however, will remain low because the d-metal bonding, and not the metallic hydrogen, dominates the behavior of electrons and phonons involved in the superconducting pairing in these compounds