Three Large-Scale Changes To The Medicare Program Could Curb Its Costs But Also Reduce Enrollment

With Medicare spending projected to increase to 24 percent of all federal spending and to equal 6 percent of the gross domestic product by 2037, policy makers are again considering ways to curb the program's spending growth. We used a microsimulation approach to estimate three scenarios: imposing a means-tested premium for Part A hospitalinsurance, introducing a premium support credit to purchase health insurance, and increasing the eligibility age to sixty-seven.We found thatthe scenarios would lead to reductions in cumulative Medicare spending in 2012 -- 36 of 2.4 -- 24.0 percent. However, the scenarios also would increase out-of-pocket spending for enrollees and, in some cases, causemillions of seniors not to enroll in the program and to be left without coverage. To achieve substantial cost savings without causing substantial lack of coverage among seniors, policy makers should consider benefitchanges in combination with other options, such as some of those now being contemplated by the Obama administration and Congress

High hops on sand influenced by added mass effects

Various animals exhibit locomotive behaviors (like sprinting and hopping) involving transient bursts of actuation coupled to the ground through internal elastic elements. The performance of such maneuvers is subject to reaction forces on the feet from the environment. On substrates like dry granular media, the laws that govern these forces are not fully understood and can vary with foot size and shape, material compaction (measured by the volume fraction, f ) and kinematics of intrusion. To gain insight into how such interactions affect jumping on granular media, we study the performance of a self-actuated spring mass robot with a 7.62-cm flat circular foot. We compare performance between two jump strategies: a single-cycle sine-wave actuation (a “single jump”) and a counter-movement pull-up phase proceeded by a single jump (a “stutter jump”); both jump methods perform well on hard ground. We systematically vary F at fixed actuation parameters for both strategies, and find that both of these jumps perform similarly poorly in loose-packed granular media, reaching only 44% of the close-packed jump height. Introducing a delay time between the pull-up phase and the push-off phase of the stutter jump (the delayed stutter jump) results in significantly improved jump heights at low volume fraction, achieving 77% of the close packed height. A 1D simulation of the robot jumping on granular media reveals that the commonly used depth dependent and velocity dependent model of granular intrusion force is insufficient to reproduce experimental jump heights. To gain insight into the behavior of the granular media during these impulsive events, we image a foot through a transparent sidewall, recording high speed videos at different packing states (F = 0.58‑0.63). To monitor grain flow, we adapt particle image velocimetry techniques to perform a 2D particle tracking velocimetry analysis on these images. A region of grains moving with similar downward speed to the intruder emerges. Subsequently, we implement an added-mass model, an effect observed in fluids, to our granular jumping simulation and find agreement with experiment

The volume of the moduli space of flat connections on a nonorientable 2-manifold

We compute the Riemannian volume on the moduli space of flat connections on a nonorientable 2-manifold, for a natural class of metrics. We also show that Witten's volume formula for these moduli spaces may be derived using Haar measure, and we give a new proof of Witten's volume formula for the moduli space of flat connections on an orientable surface using Haar measure.Comment: 31 pages, LaTeX, manuscript substantially revised. To appear in Communications in Mathematical Physic

Time and place specific policies for controlling ozone precursor nitrogen oxides in New England's electric power sector

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1994.Includes bibliographical references (p. 99-100).by Jeffrey Scott Goldman.M.S

Some open questions on anti-de Sitter geometry

We present a list of open questions on various aspects of AdS geometry, that is, the geometry of Lorentz spaces of constant curvature -1. When possible we point out relations with homogeneous spaces and discrete subgroups of Lie groups, to Teichm\"uller theory, as well as analogs in hyperbolic geometry.Comment: Not a research article in the usual sense but rather a list of open questions. 19 page

Variability in antifungal and antiviral use in hospitalized children

We analyzed antifungal and antiviral prescribing among high-risk children across freestanding children’s hospitals. Antifungal and antiviral days of therapy varied across hospitals. Benchmarking antifungal and antiviral use and developing antimicrobial stewardship strategies to optimize use of these high cost agents is needed.Infect Control Hosp Epidemiol2017;38:743–746</jats:p