Effect of paramagnetic fluctuations on a Fermi-surface topological transition in two dimensions

We study the Fermi-surface topological transition of the pocket-opening type in a two-dimensional Fermi liquid. We find that the paramagnetic fluctuations in an interacting Fermi liquid typically drive the transition first order at zero temperature. We first gain insight from a calculation using second-order perturbation theory in the self-energy. This is valid for weak interaction and far from instabilities. We then extend the results to stronger interaction, using the self-consistent fluctuation approximation. Experimental signatures are given in light of our results

Scaling relation for determining the critical threshold for continuum percolation of overlapping discs of two sizes

We study continuum percolation of overlapping circular discs of two sizes. We propose a phenomenological scaling equation for the increase in the effective size of the larger discs due to the presence of the smaller discs. The critical percolation threshold as a function of the ratio of sizes of discs, for different values of the relative areal densities of two discs, can be described in terms of a scaling function of only one variable. The recent accurate Monte Carlo estimates of critical threshold by Quintanilla and Ziff [Phys. Rev. E, 76 051115 (2007)] are in very good agreement with the proposed scaling relation.Comment: 4 pages, 3 figure

Comparison of Employment Disability Discrimination Claims with Other Statutes Across U.S. Equal Opportunity Commission and Fair Employment Practice Agencies Nationally

Although 15 years have passed since the employment provisions of the Americans with Disabilities Act of 1990 (ADA) became effective, significant employment disparities for persons with disabilities persist. It is important to assess how employer policies and practices may contribute to this disparity. Analyses of employment-related discrimination claims and subsequent legal outcomes are an important source of information about where and how disability employment discrimination is perceived to be happening. Examining the disability employment discrimination charges filed with the U.S. Equal Employment Opportunity Commission (EEOC) and Fair Employment Practice Agencies (FEPAs) within states can inform an understanding of where specific issues continue. This research uses the EEOC\u27s Charge Data System (CDS) (later called the Integrated Mission System, IMS) to explore difference between the filing of discrimination claims at EEOC offices and state FEPA offices. To date, most analyses of these charges have occurred on the EEOC charge data only. Yet of the 328,001 disability employment discrimination charges filed across both agencies during 1993 – 2003, almost half (46 percent) of these charges have been filed in FEPA offices. Analyzing both sets of data provides a fuller picture of disability employment discrimination claims nationally and subsequently further informs our understanding of where problems may be occurring in the implementation of the ADA Title I provisions. For more information, Contact Susanne Bruyère: [email protected]

User Guide: A Guide to Disability Statistics from the National Assessment of Educational Programs (NAEP)

Policymakers, service providers, disability advocacy groups and researchers use disability statistics for a wide variety of purposes. A common problem that these groups encounter is finding a data source, a disability definition and/or a statistical method that provides them with a disability statistic that is both relevant to their needs and useful. The mission of the Cornell StatsRRTC is to bridge the divide between the sources of disability data and the users of disability statistics. One product of this effort is a series of User Guides to national survey data sets that collect information on the disability population. The purpose of each of the User Guides is to provide disability data users with: 1. An easily accessible guide to the disability information available in the nationally representative survey; 2. Estimates of the population with a disability, the disability prevalence rate, and estimates of participation-related statistics; 3. A description of the unique features of the dataset that will help disability statistics users determine whether the dataset can provide them with the statistic that they need; and 4. A description of how the dataset compares to other national data that are used to describe the population with disabilities. This User Guide contains information on the National Assessment of Educational Programs (NAEP), also known as “the Nation\u27s Report Card.” Unlike the other data sources addressed by the User Guide Series, the NAEP focuses solely on children. As a result, the focus of this Guide will shift to the inclusion and accommodation of educational activities of children with disabilities, as opposed to adult employment and economic well-being, which are the focus of many of the other User Guide

Impact of violence against women on severe acute maternal morbidity in the intensive care unit, including neonatal outcomes: a case–control study protocol in a tertiary healthcare facility in Lima, Peru

Introduction Preventing and reducing violence against women (VAW) and maternal mortality are Sustainable Development Goals. Worldwide, the maternal mortality ratio has fallen about 44% in the last 25 years, and for one maternal death there are many women affected by severe acute maternal morbidity (SAMM) requiring management in the intensive care unit (ICU). These women represent the most critically ill obstetric patients of the maternal morbidity spectrum and should be studied to complement the review of maternal mortality. VAW has been associated with all-cause maternal deaths, and since many women (30%) endure violence usually exerted by their intimate partners and this abuse can be severe during pregnancy, it is important to determine whether it impacts SAMM. Thus, this study aims to investigate the impact of VAW on SAMM in the ICU. Methods and analysis This will be a prospective case-control study undertaken in a tertiary healthcare facility in Lima-Peru, with a sample size of 109 cases (obstetric patients admitted to the ICU) and 109 controls (obstetric patients not admitted to the ICU selected by systematic random sampling). Data on social determinants, medical and obstetric characteristics, VAW, pregnancy and neonatal outcome will be collected through interviews and by extracting information from the medical records using a pretested form. Main outcome will be VAW rate and neonatal mortality rate between cases and controls. VAW will be assessed by using the WHO instrument. Binary logistic followed by stepwise multivariate regression and goodness of fit test will assess any association between VAW and SAMM. Ethics and dissemination Ethical approval has been granted by the La Trobe University, Melbourne-Australia and the tertiary healthcare facility in Lima-Peru. This research follows the WHO ethical and safety recommendations for research on VAW. Findings will be presented at conferences and published in peer-reviewed journals

Living on a trophic subsidy: Algal quality drives an upper-shore herbivore’s consumption, preference and absorption but not growth rates

Indexación: Scopus.The transfer of seaweeds from subtidal bottoms to nearby intertidal rocky shores is a common but often overlooked phenomenon. Freshly detached seaweeds often represent critical trophic subsidies for herbivores living in upper-shore rocky intertidal areas, such as the marine snail Diloma nigerrima. This species relies on three species of seaweeds for food and displays feeding strategies to deal with a resource that is scarce and at times unpredictable. This study focused on the nutritional quality of freshly detached algae (Durvillaea antarctica, Lessonia spicata and Lessonia trabeculata) and measured Diloma nigerrima’s algal consumption rates in trials with and without choice. Absorption efficiency and growth of individual snails fed on each alga were also measured. Durvillaea antarctica had the highest nutritional quality and was the most consumed algae in both single and multiple-choice trials. Absorption efficiency was also highest for D. antarctica but growth rates of snails fed with this species were similar to those fed with the other algae. Combined, these results suggest that D. nigerrima has the ability to discriminate among seaweeds based on their nutritional quality. A potential increase in oxygen uptake when D. nigerrima is consuming the preferred food item is also proposed as a plausible hypothesis to explain the mismatch between snails’ preference and growth rate. These results aim to guide further studies on trophic subsidies and their role in coastal systems. © 2018 Quintanilla-Ahumada et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.https://journals.plos.org/plosone/article?id=10.1371/journal.pone.019612

Thermal versus quantum fluctuations of optical-lattice fermions

We show that, for fermionic atoms in a one-dimensional optical lattice, the fraction of atoms in doubly occupied sites is a highly nonmonotonic function of temperature. We demonstrate that this property persists even in the presence of realistic harmonic confinement, and that it leads to a suppression of entropy at intermediate temperatures that offers a route to adiabatic cooling. Our interpretation of the suppression is that such intermediate temperatures are simultaneously too high for quantum coherence and too low for significant thermal excitation of double occupancy thus offering a clear indicator of the onset of quantum fluctuations.Publisher PDFPeer reviewe

Strictly correlated uniform electron droplets

We study the energetic properties of finite but internally homogeneous D-dimensional electron droplets in the strict-correlation limit. The indirect Coulomb interaction is found to increase as a function of the electron number, approaching the tighter forms of the Lieb-Oxford bound recently proposed by Rasanen et al. [Phys. Rev. Lett. 102, 206406 (2009)]. The bound is satisfied in three-, two-, and one-dimensional droplets, and in the latter case it is reached exactly - regardless of the type of interaction considered. Our results provide useful reference data for delocalized strongly correlated systems, and they can be used in the development and testing of exchange-correlation density functionals in the framework of density-functional theory

Condensation in an Economic Model with Brand Competition

We present a linear agent based model on brand competition. Each agent belongs to one of the two brands and interacts with its nearest neighbors. In the process the agent can decide to change to the other brand if the move is beneficial. The numerical simulations show that the systems always condenses into a state when all agents belong to a single brand. We study the condensation times for different parameters of the model and the influence of different mechanisms to avoid condensation, like anti monopoly rules and brand fidelity.Comment: Accepted in: International Journal of Modern Physics

Spatial and structural stability in thermoelasto-dynamics on a half-cylinder

EnThe linear nonhomogeneous thermoelastodynamic problem in a half-cylinder is considered subject to assigned initial conditions, and to the displacement and temperature being specified over the base, and vanishing on the lateral boundary. Spatial stability, derived from a differential inequality, establishes that the mean-square volume integrals of displacement and temperature are bounded above by a decaying function of axial distance for each finite positive time instant. Structural stability, which here relates to continuous dependence of the displacement on the thermal coupling, depends upon the construction of further differential inequalities