Background. Cardiovascular disease (CVD) risk prediction tools are often applied to populations beyond those in which they were designed when validated tools for specific subpopulations are ...unavailable. Methods. Using data from 2283 human immunodeficiency virus (HIV)–infected adults aged ≥18 years, who were active in the HIV Outpatient Study (HOPS), we assessed performance of 3 commonly used CVD prediction models developed for general populations: Framingham general cardiovascular Risk Score (FRS), American College of Cardiology/American Heart Association Pooled Cohort equations (PCEs), and Systematic COronary Risk Evaluation (SCORE) high-risk equation, and 1 model developed in HIV-infected persons: the Data Collection on Adverse Effects of Anti-HIV Drugs (D:A:D) study equation. C-statistics assessed model discrimination and the ratio of expected to observed events (E/O) and Hosmer-Lemeshow χ2 P value assessed calibration. Results. From January 2002 through September 2013, 195 (8.5%) HOPS participants experienced an incident CVD event in 15 056 person-years. The FRS demonstrated moderate discrimination and was well calibrated (C-statistic: 0.66, E/O: 1.01, P = .89). The PCE and D:A:D risk equations demonstrated good discrimination but were less well calibrated (C-statistics: 0.71 and 0.72 and E/O: 0.88 and 0.80, respectively; P < .001 for both), whereas SCORE performed poorly (C-statistic: 0.59, E/O: 1.72; P = .48). Conclusions. Only the FRS accurately estimated risk of CVD events, while PCE and D:A:D underestimated risk. Although these models could potentially be used to rank US HIV-infected individuals at higher or lower risk for CVD, the models may fail to identify substantial numbers of HIV-infected persons with elevated CVD risk who could potentially benefit from additional medical treatment.
Managing for RADical ecosystem change Lynch, Abigail J; Thompson, Laura M; Beever, Erik A ...
Frontiers in ecology and the environment,
10/2021, Volume:
19, Issue:
8
Journal Article
Peer reviewed
Open access
Ecosystem transformation involves the emergence of persistent ecological or social–ecological systems that diverge, dramatically and irreversibly, from prior ecosystem structure and function. Such ...transformations are occurring at increasing rates across the planet in response to changes in climate, land use, and other factors. Consequently, a dynamic view of ecosystem processes that accommodates rapid, irreversible change will be critical for effectively conserving fish, wildlife, and other natural resources, and maintaining ecosystem services. However, managing ecosystems toward states with novel structure and function is an inherently unpredictable and difficult task. Managers navigating ecosystem transformation can benefit from considering broader objectives, beyond a traditional focus on resisting ecosystem change, by also considering whether accepting inevitable change or directing it along some desirable pathway is more feasible (that is, practical and appropriate) under some circumstances (the RAD framework). By explicitly acknowledging transformation and implementing an iterative RAD approach, natural resource managers can be deliberate and strategic in addressing profound ecosystem change.
Medicaid, one of the largest federal programs in the United States, gives grants to states to provide health insurance for over 60 million low-income Americans. As private health insurance benefits ...have relentlessly eroded, the program has played an increasingly important role. Yet Medicaid's prominence in the health care arena has come as a surprise. Many astute observers of the Medicaid debate have long claimed that "a program for the poor is a poor program" prone to erosion because it serves a stigmatized, politically weak clientele. Means-tested programs for the poor are often politically unpopular, and there is pressure from fiscally conservative lawmakers to scale back the $350-billion-per-year program even as more and more Americans have come to rely on it. For their part, health reformers had long assumed that Medicaid would fade away as the country moved toward universal health insurance. Instead, Medicaid has proved remarkably durable, expanding and becoming a major pillar of America's health insurance system. InMedicaid Politics, political scientist Frank J. Thompson examines the program's profound evolution during the presidential administrations of Bill Clinton, George W. Bush, and Barack Obama and its pivotal role in the epic health reform law of 2010. This clear and accessible book details the specific forces embedded in American federalism that contributed so much to Medicaid's growth and durability during this period. It also looks to the future outlining the political dynamics that could yield major program retrenchment.
Understanding the forces and magma system dynamics on timescales of seconds to minutes remains challenging. In the January 2022 phreatoplinian Hunga Tonga‐Hunga Ha'apai eruption, four remarkably ...similar seismic subevents within a 5‐min interval occurred during the intensifying early eruptive phase. The subevents are similar in waveforms and durations (∼25 s each). Each subevent begins with an unusual negative P‐wave polarity which is inferred, using full‐wave seismic modeling, to be caused by an upward single‐force mechanism at the volcano created by a magma hammer likely in response to magma flow blockage/constriction during the early part of the eruption as discharge rapidly increased over orders of magnitude with concomitant conduit geometry evolution and instability. Our proposed episodic magma hammer model is consistent with thermodynamic and phase properties of the magmatic mixture, and yields an estimate of conduit mass flow in agreement with vent discharge rates derived from satellite imagery of plume heights.
Plain Language Summary
The seismic record of the 15 January 2022 Hunga Tonga‐Hunga Ha'apai explosive eruption exhibited a remarkably regular pattern, recording repeating volcanic processes. Within an interval of ∼300 s during an early eruptive phase, four strong seismic subevents occurred and were recorded by global seismic stations. Detailed seismic analyses showed that each of these subevents is similar in waveform and duration and is characterized by a sequence of four forces: upward, downward, upward, and downward. We suggest that the first upward seismic force at the volcano was likely created by an ascending magma colliding with a blockage or conduit constriction that occurred during and because of the ongoing eruption. We attribute the other forces to upward magma backflow and piston motion in the conduit, owing to their similar time durations. The magma hammer mechanism allows us to estimate the magma flow rate in the subsurface conduit, which is consistent with the vent discharge rate observed by satellite imagery.
Key Points
The 15 January 2022 Hunga Tonga‐Hunga Ha'apai eruption had four episodic seismic subevents with similar waveforms within ∼300 s
An unusual upward force jump‐started each subevent
A magma hammer explains the force and estimates the subsurface magma mass flux which fits the vent discharge rate based on satellite data
Ecosystem transformation can be defined as the emergence of a self‐organizing, self‐sustaining, ecological or social–ecological system that deviates from prior ecosystem structure and function. These ...transformations are occurring across the globe; consequently, a static view of ecosystem processes is likely no longer sufficient for managing fish, wildlife, and other species. We present a framework that encompasses three strategies for fish and wildlife managers dealing with ecosystems vulnerable to transformation. Specifically, managers can resist change and strive to maintain existing ecosystem composition, structure, and function; accept transformation when it is not feasible to resist change or when changes are deemed socially acceptable; or direct change to a future ecosystem configuration that would yield desirable outcomes. Choice of a particular option likely hinges on anticipating future change, while also acknowledging that temporal and spatial scales, recent history and current state of the system, and magnitude of change can factor into the decision. This suite of management strategies can be implemented using a structured approach of learning and adapting as ecosystems change.
The Patient Protection and Affordable Care Act (ACA) of 2010 constituted an epic policy breakthrough, culminating a century of effort to ensure that nearly all Americans can obtain health insurance. ...The articles in this special issue seek to illuminate the challenges involved in implementing this law and other health reforms in a context marked by deep‐seated partisan polarization. This introductory essay provides a backdrop to frame the more specific insights of the contributors. It introduces two key legacies in place at the time of the ACA’s passage: the health insurance regime and rising health care costs. Certain pivotal provisions of the ACA then receive attention, including the “individual mandate,” health insurance exchanges, and the Medicaid expansion. This introduction shows how the ACA and related health care developments intersect with broader issues of governance and public administration: the rise of executive branch discretion within the nation's separation of powers system, the increased importance of the administrative presidency, and the emergence of fractious federalism rooted in partisan polarization.
Depletion of glutathione (GSH) is considered a critical pathogenic event promoting alcohol-induced lipotoxicity. We recently show that systemic GSH deficiency in mice harboring a global disruption of ...the glutamate-cysteine ligase modifier subunit (Gclm) gene confers protection against alcohol-induced steatosis. While several molecular pathways have been linked to the observed hepatic protection, including nuclear factor erythroid 2-related factor 2 and AMP-activated protein kinase pathways, the precise mechanisms are yet to be defined. In this study, to gain insights into the molecular mechanisms underpinning the protective effects of loss of GCLM, global profiling of hepatic polar metabolites combined with liver microarray analysis was carried out. These inter-omics analyses revealed both low GSH- and alcohol-driven changes in multiple cellular pathways involving the metabolism of amino acids, fatty acid, glucose and nucleic acids. Notably, several metabolic changes were uniquely present in alcohol-treated Gclm-null mouse livers, including acetyl-CoA enrichment and diversion of acetyl-CoA flux from lipogenesis to alterative metabolic pathways, elevation in glutamate concentration, and induction of the glucuronate pathway and nucleotide biosynthesis. These metabolic features reflect low GSH-elicited cellular response to chronic alcohol exposure, which is beneficial for the maintenance of hepatic redox and metabolic homeostasis. The current study indicates that fine-tuning of hepatic GSH pool may evoke metabolic reprogramming to cope with alcohol-induced cellular stress.
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•GSH-deficient (Gclm-KO) liver is acetyl-CoA and glutamate enriched.•Low GSH promotes pyruvate and fatty acid oxidation and inhibits lipogenesis.•Ethanol-exposed WT and KO liver show differential changes in acetyl-CoA metabolism.•Transcriptional and post-transcriptional mechanisms underlie metabolic adaptions.
Abstract
Intensifying global change is propelling many ecosystems toward irreversible transformations. Natural resource managers face the complex task of conserving these important resources under ...unprecedented conditions and expanding uncertainty. As once familiar ecological conditions disappear, traditional management approaches that assume the future will reflect the past are becoming increasingly untenable. In the present article, we place adaptive management within the resist–accept–direct (RAD) framework to assist informed risk taking for transforming ecosystems. This approach empowers managers to use familiar techniques associated with adaptive management in the unfamiliar territory of ecosystem transformation. By providing a common lexicon, it gives decision makers agency to revisit objectives, consider new system trajectories, and discuss RAD strategies in relation to current system state and direction of change. Operationalizing RAD adaptive management requires periodic review and update of management actions and objectives; monitoring, experimentation, and pilot studies; and bet hedging to better identify and tolerate associated risks.
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