Visual, Motor and Attentional Influences on Proprioceptive Contributions to Perception of Hand Path Rectilinearity during Reaching

We examined how proprioceptive contributions to perception of hand path straightness are influenced by visual, motor and attentional sources of performance variability during horizontal planar reaching. Subjects held the handle of a robot that constrained goal-directed movements of the hand to the paths of controlled curvature. Subjects attempted to detect the presence of hand path curvature during both active (subject driven) and passive (robot driven) movements that either required active muscle force production or not. Subjects were less able to discriminate curved from straight paths when actively reaching for a target versus when the robot moved their hand through the same curved paths. This effect was especially evident during robot-driven movements requiring concurrent activation of lengthening but not shortening muscles. Subjects were less likely to report curvature and were more variable in reporting when movements appeared straight in a novel “visual channel” condition previously shown to block adaptive updating of motor commands in response to deviations from a straight-line hand path. Similarly, compromised performance was obtained when subjects simultaneously performed a distracting secondary task (key pressing with the contralateral hand). The effects compounded when these last two treatments were combined. It is concluded that environmental, intrinsic and attentional factors all impact the ability to detect deviations from a rectilinear hand path during goal-directed movement by decreasing proprioceptive contributions to limb state estimation. In contrast, response variability increased only in experimental conditions thought to impose additional attentional demands on the observer. Implications of these results for perception and other sensorimotor behaviors are discussed

Monitoring the Impact of Health Reform on Americans 50-64: Medicaid Expansion and Marketplace Implementation Increased Health Coverage

This survey shows that the share of 50- to 64-year-olds without health insurance fell between December 2013 and March 2014. In states that expanded their Medicaid programs, a greater share of previously uninsured adults gained coverage, particularly among groups that have traditionally faced barriers to obtaining it. The survey also found that the newly insured differed in key ways from those who reported being insured for all of the past 12 months. On average, more were low income, and more reported that they had had trouble paying medical bills. This paper is part of a series that looks at the experience of 50- to 64-year-olds during the first open enrollment period of the Affordable Care Act (ACA)

Wolf-Rayet Central Stars of Planetary Nebulae: Their Evolution and Properties

Over the past decade, the number of planetary nebula central stars (CSPN) known to exhibit the Wolf-Rayet (WR) phenomenon has grown substantially. Many of these discoveries have resulted from the Macquarie/AAO/Strasbourg Ha (MASH) PN Survey. While WR CSPN constitute a relatively rare stellar type (<10% of CS), there are indications that the proportion of PN harbouring them may increase as spectroscopy of more central stars is carried out. In addition, with new and better distances from the Ha surface brightness-radius relationship of Frew (2008), we can attempt a dynamical age sequence which may provide insight into the evolution of these stars.Comment: 4 pages, 2 figures. Presented at the Asymmetric Planetary Nebulae V Conference in Bowness-on-Windermere, UK, June 201

Use of an index to reflect the aggregate burden of long-term exposure to criteria air pollutants in the United States.

Air pollution control in the United States for five common pollutants--particulate matter, ground-level ozone, sulfur dioxide, nitrogen dioxide, and carbon monoxide--is based partly on the attainment of ambient air quality standards that represent a level of air pollution regarded as safe. Regulatory and health agencies often focus on whether standards for short periods are attained; the number of days that standards are exceeded is used to track progress. Efforts to explain air pollution to the public often incorporate an air quality index that represents daily concentrations of pollutants. While effects of short-term exposures have been emphasized, research shows that long-term exposures to lower concentrations of air pollutants can also result in adverse health effects. We developed an aggregate index that represents long-term exposure to these pollutants, using 1995 monitoring data for metropolitan areas obtained from the U.S. Environmental Protection Agency's Aerometric Information Retrieval System. We compared the ranking of metropolitan areas under the proposed aggregate index with the ranking of areas by the number of days that short-term standards were exceeded. The geographic areas with the highest burden of long-term exposures are not, in all cases, the same as those with the most days that exceeded a short-term standard. We believe that an aggregate index of long-term air pollution offers an informative addition to the principal approaches currently used to describe air pollution exposures; further work on an aggregate index representing long-term exposure to air pollutants is warranted

Monitoring the Impact of Health Care Reforms on Americans 50-64: Awareness and Coverage Expectations

This survey found widespread awareness among Americans ages 50 to 64 about the new health insurance Marketplace that had been created by the Affordable Care Act (ACA). Those with the most to gain from the ACA -- the uninsured and those with nongroup (individual) insurance -- expressed the greatest interest in using the Marketplace to learn about new coverage options. Most of those already insured expected to keep their same source of coverage in 2014, whereas the uninsured had mixed expectations. This paper is part of a series that looks at the experiences of 50- to 64-year-olds during the ACA's first open enrollment period

Monitoring the Impact of Health Reform on Americans 50-64: Use of Insurance Marketplaces

This survey found that 9 out of 10 Americans ages 50 to 64 were aware of the new health insurance Marketplace that had been created by the Affordable Care Act (ACA). The survey found that, despite widespread awareness of the Marketplace among this age group, relatively few who knew about the Marketplace were interested in using it to acquire new coverage. The survey also found that 50- to 64-year-olds' use of the Marketplace varied widely by health insurance status and income. This paper is part of a series that looks at the experiences of 50- to 64-year-olds during the ACA's first open enrollment period