Issues in health reform: How changes in eligibility may move millions back and forth between Medicaid and insurance exchanges

The Affordable Care Act will extend health insurance coverage by both expanding Medicaid eligibility and offering premium subsidies for the purchase of private health insurance through state health insurance exchanges. But by definition, eligibility for these programs is sensitive to income and can change over time with fluctuating income and changes in family composition. The law specifies no minimum enrollment period, and subsidy levels will also change as income rises and falls. Using national survey data, we estimate that within six months, more than 35 percent of all adults with family incomes below 200 percent of the federal poverty level will experience a shift in eligibility from Medicaid to an insurance exchange, or the reverse; within a year, 50 percent, or 28 million, will. To minimize the effect on continuity and quality of care, states and the federal government should adopt strategies to reduce the frequency of coverage transitions and to mitigate the disruptions caused by those transitions. Options include establishing a minimum guaranteed eligibility period and “dually certifying” some plans to serve both Medicaid and exchange enrollees

Strengthening Medicaid as a Critical Lever in Building a Culture of Health

Strengthening Medicaid as a Critical Lever in Building a Culture of Health is a nonpartisan study panel report which offers a series of steps that would enable Medicaid to leverage its unique role as an insurer to increase its capacity for addressing the underlying social determinants of health. The study panel was convened to assess the current and possible future role of Medicaid in building a Culture of Health. The panel included state Medicaid program directors, public health and health policy experts, health researchers, medical and health professionals, and health plan representatives.The panel discussed strategies that could increase Medicaid's potential to help move the dial on individual and population health, while improving health care quality and program efficiency. The findings are divided into two categories: those that can be accomplished administratively (without any further legislative action) and those that would require legislative change.The report also recognizes key challenges that Medicaid faces, including the high cost states already bear for insuring vulnerable populations, the chronic insufficiency of funding for social service programs that could partner with Medicaid to foster health, and the complexities of implementing innovative care delivery models, among others.While the current political landscape signals new policy discussions about the future of the program and its funding, the analysis and options included in this report recognize that health care coverage is a critical underpinning for improving health. Whether and how Medicaid might be changed, its role as an insurer is foundational; this report assumes that Medicaid will continue to be central to the health care safety net as an insurer of low-income, vulnerable populations

Invasive earthworms modulate native plant trait expression and competition

Biological invasions have major impacts on a variety of ecosystems and threaten native biodiversity. Earthworms have been absent from northern parts of North America since the last ice age, but non-native earthworms were recently introduced there and are now being spread by human activities. While past work has shown that plant communities in earthworm-invaded areas change towards a lower diversity mainly dominated by grasses, the underlying mechanisms related to changes in the biotic interactions of the plants are not well understood. Here, we used a trait-based approach to study the effect of earthworms on interspecific plant competition and aboveground herbivory. We conducted a microcosm experiment in a growth chamber with a full-factorial design using three plant species native to northern North American deciduous forests, Poa palustris (grass), Symphyotrichum laeve (herb) and Vicia americana (legume), either growing in monoculture or in a mixture of three. These plant community treatments were crossed with earthworm (presence or absence) and herbivore (presence or absence) treatments. Eight out of the fourteen above- and belowground plant functional traits studied were significantly affected by earthworms, either by a general effect or in interaction with plant species identity, plant diversity level and/or herbivore presence. Earthworms increased the aboveground productivity and the number of inflorescences of the grass P. palustris. Further, earthworms and herbivores together affected root tissue density of P. palustris and the specific leaf area of V. americana. In this study, earthworm presence gave a competitive advantage to the grass species P. palustris by inducing changes in plant functional traits. Our results suggest that invasive earthworms can alter competitive and multitrophic interactions of plants, shedding light on some of the mechanisms behind invasive earthworm-induced plant community changes in northern North America forests.NE, LT and RS acknowledge funding from the German Research Foundation (DFG Ei 862/18-1). Authors also acknowledge the support of the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, funded by the German Research Foundation (DFG–FZT 118, 202548816). Moreover, NE acknowledges funding by DFG (Ei 862/29-1 and Ei 862/31-1) as well as by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant no. 677232)

The Combined Effects of Warming and Body Size on the Stability of Predator-Prey Interactions

Environmental temperature and body size are two prominent drivers of predation. Despite the ample evidence of their independent effects, the combined impact of temperature and predator-prey body size ratio on the strength and stability of trophic interactions is not fully understood. We experimentally tested how water temperature alters the functional response and population stability of dragonfly nymphs (Cordulegaster boltonii) feeding on freshwater amphipods (Gammarus pulex) across a gradient of their body size ratios. Attack coefficients were highest for small predators feeding on small prey at low temperatures, but shifted toward the largest predators feeding on larger prey in warmer environments. Handling time appeared to decrease with increasing predator and prey body size in the cold environment, but increase at higher temperatures. These findings indicate interactive effects of temperature and body size on functional responses. There was also a negative effect of warming on the stability of predator and prey populations, but this was counteracted by a larger predator-prey body size ratio at higher temperatures. Here, a greater Hill exponent reduced feeding at low prey densities when predators were much larger than their prey, enhancing the persistence of both predator and prey populations in the warmer environment. These experimental findings provide new mechanistic insights into the destabilizing effect of warming on trophic interactions and the key role of predator-prey body size ratios in mitigating these effects

The Wikipedia Gender Gap Revisited: Characterizing Survey Response Bias with Propensity Score Estimation

Opt-in surveys are the most widespread method used to study participation in online communities, but produce biased results in the absence of adjustments for non-response. A 2008 survey conducted by the Wikimedia Foundation and United Nations University at Maastricht is the source of a frequently cited statistic that less than 13% of Wikipedia contributors are female. However, the same study suggested that only 39.9% of Wikipedia readers in the US were female – a finding contradicted by a representative survey of American adults by the Pew Research Center conducted less than two months later. Combining these two datasets through an application and extension of a propensity score estimation technique used to model survey non-response bias, we construct revised estimates, contingent on explicit assumptions, for several of the Wikimedia Foundation and United Nations University at Maastricht claims about Wikipedia editors. We estimate that the proportion of female US adult editors was 27.5% higher than the original study reported (22.7%, versus 17.8%), and that the total proportion of female editors was 26.8% higher (16.1%, versus 12.7%).Sloan School of ManagementHarvard University. Berkman Center for Internet & SocietyFord Visionary Leadership FundNorthwestern University (Evanston, Ill.

Temperature alters the size selectivity of Southern Ocean fish

A primary response of many marine ectotherms to warming is a reduction in body size, to lower the metabolic costs associated with higher temperatures. The impact of such changes on ecosystem dynamics and stability will depend on the resulting changes to community size-structure, but few studies have investigated how temperature affects the relative size of predators and their prey in natural systems. We utilise >3700 prey size measurements from ten Southern Ocean lanternfish species sampled across >10° of latitude to investigate how temperature influences predator-prey size relationships and size-selective feeding. As temperature increased, we show that predators became closer in size to their prey, which was primarily associated with a decline in predator size and an increase in the relative abundance of intermediate-sized prey. The potential implications of these changes include reduced top-down control of prey populations and a reduction in the diversity of predator-prey interactions. Both of these factors could reduce the stability of community dynamics and ecosystem resistance to perturbations under ocean warming

The intrinsic predictability of ecological time series and its potential to guide forecasting

Successfully predicting the future states of systems that are complex, stochastic, and potentially chaotic is a major challenge. Model forecasting error (FE) is the usual measure of success; however model predictions provide no insights into the potential for improvement. In short, the realized predictability of a specific model is uninformative about whether the system is inherently predictable or whether the chosen model is a poor match for the system and our observations thereof. Ideally, model proficiency would be judged with respect to the systems’ intrinsic predictability, the highest achievable predictability given the degree to which system dynamics are the result of deterministic vs. stochastic processes. Intrinsic predictability may be quantified with permutation entropy (PE), a model‐free, information‐theoretic measure of the complexity of a time series. By means of simulations, we show that a correlation exists between estimated PE and FE and show how stochasticity, process error, and chaotic dynamics affect the relationship. This relationship is verified for a data set of 461 empirical ecological time series. We show how deviations from the expected PE–FE relationship are related to covariates of data quality and the nonlinearity of ecological dynamics. These results demonstrate a theoretically grounded basis for a model‐free evaluation of a system's intrinsic predictability. Identifying the gap between the intrinsic and realized predictability of time series will enable researchers to understand whether forecasting proficiency is limited by the quality and quantity of their data or the ability of the chosen forecasting model to explain the data. Intrinsic predictability also provides a model‐free baseline of forecasting proficiency against which modeling efforts can be evaluated

Ultrasound imaging of the carpal tunnel during median nerve compression

Median nerve (MN) compression is a recognized component of carpal tunnel syndrome (CTS). In order to document compressive changes in the MN during hand activity, the carpal tunnel was imaged with neuromuscular ultrasound (NMUS). Ten patients with CTS and five normal controls underwent NMUS of the MN at rest and during dynamic stress testing (DST). DST maneuvers involve sustained isometric flexion of the distal phalanges of the first three digits. During DST in the CTS patients, NMUS demonstrated MN compression between the contracting thenar muscles ventrally and the taut flexor tendons dorsally. The mean MN diameter decreased nearly 40%, with focal narrowing in the mid-distal carpal canal. Normal controls demonstrated no MN compression and a tendency towards MN enlargement, with an average diameter increase of 17%. Observing the pathologic mechanism of MN injury during common prehensile hand movements could help better understand how to treat and prevent CTS