Competing Glauber and Kawasaki Dynamics

Using a quantum formulation of the master equation we study a kinetic Ising model with competing stochastic processes: the Glauber dynamics with probability $p$ and the Kawasaki dynamics with probability $1 - p$. Introducing explicitely the coupling to a heat bath and the mutual static interaction of the spins the model can be traced back exactly to a Ginzburg Landau functional when the interaction is of long range order. The dependence of the correlation length on the temperature and on the probability $p$ is calculated. In case that the spins are subject to flip processes the correlation length disappears for each finite temperature. In the exchange dominated case the system is strongly correlated for each temperature.Comment: 9 pages, Revte

Do Women Ask?

Women typically earn less than men. The reasons are not fully understood. Previous studies argue that this may be because (i) women ‘don’t ask’ and (ii) the reason they fail to ask is out of concern for the quality of their relationships at work. This account is difficult to assess with standard labor-economics data sets. Hence we examine direct survey evidence. Using matched employer-employee data from 2013-14, the paper finds that the women-don’t-ask account is incorrect. Once an hours-of-work variable is included in ‘asking’ equations, hypotheses (i) and (ii) can be rejected. Women do ask. However, women do not get

Do Women Ask?

Females typically earn less than males. The reasons are not fully understood. This paper reexamines the idea that women ‘don’t ask’, which potentially assigns part of the responsibility for the gender pay gap on to female behavior. Such an account cannot readily be tested with standard data sets. This paper is the first to be able to use matched employer-employee data in which workers are questioned about their asking behaviour. It concludes that males and females ask equally often for promotions and raises. The paper’s empirical results suggest, however, that while women do now ask they ‘don’t get’

Phase transition in an asymmetric generalization of the zero-temperature Glauber model

An asymmetric generalization of the zero-temperature Glauber model on a lattice is introduced. The dynamics of the particle-density and specially the large-time behavior of the system is studied. It is shown that the system exhibits two kinds of phase transition, a static one and a dynamic one.Comment: LaTeX, 9 pages, to appear in Phys. Rev. E (2001

Phase transition in an asymmetric generalization of the zero-temperature q-state Potts model

An asymmetric generalization of the zero-temperature q-state Potts model on a one dimensional lattice, with and without boundaries, has been studied. The dynamics of the particle number, and specially the large time behavior of the system has been analyzed. In the thermodynamic limit, the system exhibits two kinds of phase transitions, a static and a dynamic phase transition.Comment: 11 pages, LaTeX2

Proposed Measurement of an Effective Flux Quantum in the Fractional Quantum Hall Effect

We consider a channel of an incompressible fractional-quantum-Hall-effect (FQHE) liquid containing an island of another FQHE liquid. It is predicted that the resistance of this channel will be periodic in the flux through the island, with the period equal to an odd integer multiple of the fundamental flux quantum, $\phi_{0}=hc/e$. The multiplicity depends on the quasiparticle charges of the two FQHE liquids.Comment: Late

Atmospheric nutrient input to coastal areas: reducing the uncertainties

A significant fraction of the total nitrogen entering coastal and estuarine ecosystems along the eastern U.S. coast arises from atmospheric deposition; however, the exact role of atmospherically derived nitrogen in the decline of the health of coastal, estuarine, and inland waters is still uncertain. From the perspective of coastal ecosystem eutrophication, nitrogen compounds from the air, along with nitrogen from sewage, industrial effluent, and fertilizers, become a source of nutrients to the receiving ecosystem. Eutrophication, however, is only one of the detrimental impacts of the emission of nitrogen containing compounds to the atmosphere. Other adverse effects include the production of tropospheric ozone, acid deposition, and decreased visibility (photochemical smog). Assessments of the coastal eutrophication problem indicate that the atmospheric deposition loading is most important in the region extending from Albemarle/Parnlico Sounds to the Gulf of Maine; however, these assessments are based on model outputs supported by a meager amount of actual data. The data shortage is severe. The National Research Council specifically mentions the atmospheric role in its recent publication for the Committee on Environmental and Natural Resources, Priorities for Coastal Ecosystem Science (1994). It states that, "Problems associated with changes in the quantity and quality of inputs to coastal environments from runoff and atmospheric deposition are particularly important [to coastal ecosystem integrity]. These include nutrient loading from agriculture and fossil fuel combustion, habitat losses from eutrophication, widespread contamination by toxic materials, changes in riverborne sediment, and alteration of coastal hydrodynamics.

Mechanisms of Unexplained Anemia in the Nursing Home

To characterize anemia in elderly nursing home residents. Design : Prospective multiinstitutional cohort study. Setting : Five nursing homes. Participants : From retrospective analysis, residents found to be anemic using chart review were prospectively randomized. Of the 81 residents enrolled, 60 were anemic. Measurements : Chart review for medical history and factors related to treatment or history of anemia, extensive laboratory evaluation for causes of anemia, and classification of anemia by two hematologists. Results : Among the 60 anemic residents, the causes of anemia were idiopathic (n=27), iron-deficiency (n=14), anemia associated with chronic disease (n=8), anemia of renal insufficiency (n=6), and other (n=5). The eryrthropoietin (EPO) response to anemia was lower in residents with idiopathic anemia (IA) than in those with iron-deficiency anemia, and this correlated with renal function as estimated using calculated creatinine clearance. In this elderly population, advancing age was not correlated with lower EPO response. Conclusion : IA is common in nursing home residents. A lower EPO response contributes to the high prevalence of anemia in this setting and may be due, in part, to occult renal dysfunction.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65745/1/j.1532-5415.2004.52116.x.pd

Algebraic Bethe ansatz for the one-dimensional Hubbard model with open boundaries

The one-dimensional Hubbard model with open boundary conditions is exactly solved by means of algebraic Bethe ansatz. The eigenvalue of the transfer matrix, the energy spectrum as well as the Bethe ansatz equations are obtained.Comment: Only LaTex file; no figur