428 research outputs found

    An observation on CarnapĘĽs Continuum and stochastic independencies

    Get PDF
    We characterize those identities and independencies which hold for all probability functions on a unary language satisfying the Principle of Atom Exchangeability. We then show that if this is strengthen to the requirement that Johnson's Sufficientness Principle holds, thus giving Carnap's Continuum of inductive methods for languages with at least two predicates, then new and somewhat inexplicable identities and independencies emerge, the latter even in the case of Carnap's Continuum for the language with just a single predicate

    Implementing the New Ecosystem Services Mandate of the Section 404 Compensatory Mitigation Program--A Catalyst for Advancing Science and Policy

    Get PDF
    On April 10, 2008, the U.S. Army Corps of Engineers (Corps) and Environmental Protection Agency (EPA) jointly published final regulations defining standards and procedures for authorizing compensatory mitigation of impacts to aquatic resources the Corps permits under Section 404 of the Clean Water Act (Section 404). Prior to the rule, the Section 404 compensatory mitigation program had been administered under a mish-mash of guidances, inter-agency memoranda, and other policy documents issued over the span of 17 years. A growing tide of policy and science scholarship criticized the program\u27s administration as not accounting for the potential redistribution of ecosystem services that results when wetlands are filled at impact sites and mitigation wetlands are provided at possibly significant distances away. Although motivated primarily by the need to bring the program under one comprehensive regulatory framework, the new rule also for the first time introduces ecosystem services into the mitigation decision-making standards, requiring that compensatory mitigation...should be located where it is most likely to successfully replace lost...services. Easily overlooked in the in the 210-page Federal Register document, this is a potentially significant development, but it will be unlikely to gain policy traction without substantial research into the development of efficient and reliable wetland ecosystem service assessment methods. To help orient such research efforts, this article provides: (1) background on the compensatory mitigation program and ecosystem services prior to promulgation of the new rule; (2) an overview of how the new rule integrates ecosystem service analysis into compensatory mitigation decisions; and (3) suggestions for a research agenda to support implementation of that feature of the rule

    Sub-wavelength diffraction-free imaging with low-loss metal-dielectric multilayers

    Get PDF
    We demonstrate numerically the diffraction-free propagation of sub-wavelength sized optical beams through simple elements built of metal-dielectric multilayers. The proposed metamaterial consists of silver and a high refractive index dielectric, and is designed using the effective medium theory as strongly anisotropic and impedance matched to air. Further it is characterised with the transfer matrix method, and investigated with FDTD. The diffraction-free behaviour is verified by the analysis of FWHM of PSF in the function of the number of periods. Small reflections, small attenuation, and reduced Fabry Perot resonances make it a flexible diffraction-free material for arbitrarily shaped optical planar elements with sizes of the order of one wavelength.Comment: 5 pages, 4 figure

    Gamow-Teller Matrix Elements and the (p,n) Reaction

    Get PDF
    This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

    Spin Transfer Measurements for (p,n) Reactions at Intermediate Energy

    Get PDF
    This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

    Advice of the Scientific Advisory Committee on Seal Rehabilitation in the Netherlands

    Get PDF
    Two species of seal breed in the Netherlands, the grey seal (Halichoerus grypus) and the harbour seal (Phoca vitulina). The populations of both species have increased markedly over the past 40 years. Harbour seals have recovered from a minimum number of around 500 in 1980 to some 9,000 seals in 2016 (Figure 1). Grey seals were effectively absent from the Netherlands until 1980, but have made a remarkable recovery; the numbers counted during the annual moult increased to around 5,100 in 2016. The number of pups born each year for both species is equivalent to around 20% of the number of seals counted during the moult

    Cluster Analysis of Cardiovascular Phenotypes in Patients With Type 2 Diabetes and Established Atherosclerotic Cardiovascular Disease: A Potential Approach to Precision Medicine

    Get PDF
    OBJECTIVE Phenotypic heterogeneity among patients with type 2 diabetes mellitus (T2DM) and atherosclerotic cardiovascular disease (ASCVD) is ill defined. We used cluster analysis machine-learning algorithms to identify phenotypes among trial participants with T2DM and ASCVD. RESEARCH DESIGN AND METHODS We used data from the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS) study (n = 14,671), a cardiovascular outcome safety trial comparing sitagliptin with placebo in patients with T2DM and ASCVD (median follow-up 3.0 years). Cluster analysis using 40 baseline variables was conducted, with associations between clusters and the primary composite outcome (cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for unstable angina) assessed by Cox proportional hazards models. We replicated the results using the Exenatide Study of Cardiovascular Event Lowering (EXSCEL) trial. RESULTS Four distinct phenotypes were identified: Cluster I included Caucasian men with a high prevalence of coronary artery disease; cluster II included Asian patients with a low BMI; cluster III included women with noncoronary ASCVD disease; and cluster IV included patients with heart failure and kidney dysfunction. The primary outcome occurred, respectively, in 11.6%, 8.6%, 10.3%, and 16.8% of patients in clusters I to IV. The crude difference in cardiovascular risk for the highest versus lowest risk cluster (cluster IV vs. II) was statistically significant (hazard ratio 2.74 [95% CI 2.29–3.29]). Similar phenotypes and outcomes were identified in EXSCEL. CONCLUSIONS In patients with T2DM and ASCVD, cluster analysis identified four clinically distinct groups. Further cardiovascular phenotyping is warranted to inform patient care and optimize clinical trial designs

    Clinical Outcomes in Patients with Type 2 Diabetes Mellitus and Peripheral Artery Disease: Results from the EXSCEL Trial

    Get PDF
    Background: Recent trials have identified anti-diabetes mellitus agents that lower major adverse cardiovascular event (MACE) rates, although some increase rates of lower-extremity amputation (LEA). Patients with peripheral artery disease (PAD) have greater incidence of diabetes mellitus and risk for LEA, prompting this investigation of clinical outcomes in patients with diabetes mellitus and PAD in the EXSCEL trial (Exenatide Study of Cardiovascular Event Lowering). Methods: EXSCEL evaluated the effects of once-weekly exenatide (a GLP-1 [glucagon-like peptide-1] receptor agonist) versus placebo on the rates of the primary composite MACE end point (cardiovascular death, myocardial infarction, or stroke) among patients with type 2 diabetes mellitus. In this post hoc analysis, we assessed the association of baseline PAD with rates of MACE, LEA, and the effects of exenatide versus placebo in patients with and without PAD. Results: EXSCEL included 2800 patients with PAD (19% of the trial population). These individuals had higher unadjusted and adjusted rates of MACE compared with patients without PAD (13.6% versus 11.4%, respectively) as well as a higher adjusted hazard ratio (adjusted hazard ratio, 1.13 [95% CI, 1.00-1.27]; P=0.047). Patients with PAD had higher all-cause mortality (adjusted hazard ratio 1.38 [95% CI, 1.20-1.60]; P<0.001) and more frequent LEA (adjusted hazard ratio 5.48 [95% CI, 4.16-7.22]; P<0.001). Patients treated with exenatide or placebo had similar rates of MACE and LEA, regardless of PAD status. Conclusions: EXSCEL participants with PAD had higher rates of all-cause mortality and LEA compared with those without PAD. There were no differences in MACE or LEA rates with exenatide versus placebo. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT01144338

    Recent developments in planet migration theory

    Full text link
    Planetary migration is the process by which a forming planet undergoes a drift of its semi-major axis caused by the tidal interaction with its parent protoplanetary disc. One of the key quantities to assess the migration of embedded planets is the tidal torque between the disc and planet, which has two components: the Lindblad torque and the corotation torque. We review the latest results on both torque components for planets on circular orbits, with a special emphasis on the various processes that give rise to additional, large components of the corotation torque, and those contributing to the saturation of this torque. These additional components of the corotation torque could help address the shortcomings that have recently been exposed by models of planet population syntheses. We also review recent results concerning the migration of giant planets that carve gaps in the disc (type II migration) and the migration of sub-giant planets that open partial gaps in massive discs (type III migration).Comment: 52 pages, 18 figures. Review article to be published in "Tidal effects in Astronomy and Astrophysics", Lecture Notes in Physic
    • …
    corecore