4,467 research outputs found
Local modulations of the spin-fluctuation mediated pairing interaction by impurities in d-wave superconductors
We present a self-consistent real space formulation of spin-fluctuation
mediated d-wave pairing. By calculating all relevant inhomogeneous spin and
charge susceptibilities in real space within the random phase approximation
(RPA), we obtain the effective pairing interaction and study its spatial
dependence near both local potential and hopping impurities. A remarkably large
enhancement of the pairing interaction may be obtained near the impurity site.
We discuss the relevance of our result to inhomogeneities observed by scanning
tunneling spectroscopy on the surface of cuprate superconductors.Comment: 8 pages, 7 figure
How Demanding Should Equality of Opportunity Be, and How Much Have We Achieved?
[Excerpt] This chapter proposes tests of various notions of equality of opportunity and applies them to intergenerational income data for the United States and Britain. Agreement is widespread that equality of opportunity holds in a society if the chances that individuals have to succeed depend only on their own efforts and not on extraneous circumstances that may inhibit or expand those chances. What is contentious, however, is what constitutes effort and circumstances. Most people, we think, would say that the social connections of an individual\u27s parents would be included among circumstances: equality of opportunity is incomplete if some individuals get ahead because they have well-connected parents. This and other channels through which circumstances affect income opportunities in an intergenerational context are discussed in Section 2.
Section 3 then formulates four, increasingly stringent criteria for equality of opportunity. In Section 4, we turn to an empirical implementation of these criteria to test for equality of opportunity in the United States and Britain. The results, presented in Section 5, provide only the weakest of support for equality of opportunity in the United States and no support at all in Britain.
Concluding remarks are presented in Section 6
Global Governance and the Limits of Health Security
The Ebola outbreak in West Africa has exposed the limits of the current approach to the global governance of infectious diseases, which mixes public health and security interests. International efforts to strengthen ‘health security’ quickly faltered when confronted with weak national health systems. Costly attempts by Western governments to strengthen global health security by developing new medical countermeasures, though important, did not yield a single, effective, widely available treatment or vaccine before the outbreak occurred. The World Health Organization (WHO), which had made strengthening global health security a strategic objective, was unable to marshal a rapid international response to the epidemic due to its institutional structure and recent cutbacks in its outbreak and emergency response department. In the end, governments could only try to get ‘ahead’ of the disease via a heavily militarised response that came too late for the thousands who have already died, that remains of uncertain sustainability, and that raises profound challenges for already stretched armed forces. The time has come to move from a focus on health security and international crisis response, to a system of global governance capable of addressing infectious disease outbreaks in an orderly, organised and sustainable manner.UK Department for International Developmen
INFLUENCE OF BODY MASS INDEX ON ROWING KINEMATICS
Rowing meets the criteria for weight loss as defined by the American College of Sport Medicine. Little research exists on the influence of body shape on movement kinematics. Even if rowing is a non weight bearing exercise, the body shape may have an influence on rowing motion and joint reactions. This study investigated rowing movement kinematics between normal weight and overweight subjects. Differences were found for hip abduction and adduction angles. This knowledge can help to understand the influence of body weight and body shape on movement kinematics and can help to avoid overloading the joints
Sixth Nerve Palsy from Cholesterol Granuloma of the Petrous Apex.
Herein, we report a patient who had an isolated sixth nerve palsy due to a petrous apex cholesterol granuloma. The sixth nerve palsy appeared acutely and then spontaneously resolved over several months, initially suggesting a microvascular origin of the palsy. Subsequent recurrences of the palsy indicated a different pathophysiologic etiology and MRI revealed the lesion at the petrous apex. Surgical resection improved the compressive effect of the lesion at Dorello's canal and clinical improvement was observed. A relapsing-remitting sixth nerve palsy is an unusual presentation of this rare lesion
An in-host model of HIV incorporating latent infection and viral mutation
We construct a seven-component model of the in-host dynamics of the Human
Immunodeficiency Virus Type-1 (i.e, HIV) that accounts for latent infection and
the propensity of viral mutation. A dynamical analysis is conducted and a
theorem is presented which characterizes the long time behavior of the model.
Finally, we study the effects of an antiretroviral drug and treatment
implications.Comment: 10 pages, 7 figures, Proceedings of AIMS Conference on Differential
Equations and Dynamical Systems (2015
Egalitarian justice and expected value
According to all-luck egalitarianism, the differential distributive effects of both brute luck, which defines the outcome of risks which are not deliberately taken, and option luck, which defines the outcome of deliberate gambles, are unjust. Exactly how to correct the effects of option luck is, however, a complex issue. This article argues that (a) option luck should be neutralized not just by correcting luck among gamblers, but among the community as a whole, because it would be unfair for gamblers as a group to be disadvantaged relative to non-gamblers by bad option luck; (b) individuals should receive the warranted expected results of their gambles, except insofar as individuals blamelessly lacked the ability to ascertain which expectations were warranted; and (c) where societal resources are insufficient to deliver expected results to gamblers, gamblers should receive a lesser distributive share which is in proportion to the expected results. Where all-luck egalitarianism is understood in this way, it allows risk-takers to impose externalities on non-risk-takers, which seems counterintuitive. This may, however, be an advantage as it provides a luck egalitarian rationale for assisting ‘negligent victims’
Calibration of traffic flow models under adverse weather and application in mesoscopic network simulation
The weather-sensitive traffic estimation and prediction system (TrEPS) aims for accurate estimation and prediction of the traffic states under inclement weather conditions. Successful application of weather-sensitive TrEPS requires detailed calibration of weather effects on the traffic flow model. In this study, systematic procedures for the entire calibration process were developed, from data collection through model parameter estimation to model validation. After the development of the procedures, a dual-regime modified Greenshields model and weather adjustment factors were calibrated for four metropolitan areas across the United States (Irvine, California; Chicago, Illinois; Salt Lake City, Utah; and Baltimore, Maryland) by using freeway loop detector traffic data and weather data from automated surface-observing systems stations. Observations showed that visibility and precipitation (rain-snow) intensity have significant impacts on the value of some parameters of the traffic flow models, such as free-flow speed and maximum flow rate, while these impacts can be included in weather adjustment factors. The calibrated models were used as input in a weather-integrated simulation system for dynamic traffic assignment. The results show that the calibrated models are capable of capturing the weather effects on traffic flow more realistically than TrEPS without weather integration
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