35 research outputs found

    Climate Change, Coral Reef Ecosystems, and Management Options for Marine Protected Areas

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    Marine protected areas (MPAs) provide place-based management of marine ecosystems through various degrees and types of protective actions. Habitats such as coral reefs are especially susceptible to degradation resulting from climate change, as evidenced by mass bleaching events over the past two decades. Marine ecosystems are being altered by direct effects of climate change including ocean warming, ocean acidification, rising sea level, changing circulation patterns, increasing severity of storms, and changing freshwater influxes. As impacts of climate change strengthen they may exacerbate effects of existing stressors and require new or modified management approaches; MPA networks are generally accepted as an improvement over individual MPAs to address multiple threats to the marine environment. While MPA networks are considered a potentially effective management approach for conserving marine biodiversity, they should be established in conjunction with other management strategies, such as fisheries regulations and reductions of nutrients and other forms of land-based pollution. Information about interactions between climate change and more “traditional” stressors is limited. MPA managers are faced with high levels of uncertainty about likely outcomes of management actions because climate change impacts have strong interactions with existing stressors, such as land-based sources of pollution, overfishing and destructive fishing practices, invasive species, and diseases. Management options include ameliorating existing stressors, protecting potentially resilient areas, developing networks of MPAs, and integrating climate change into MPA planning, management, and evaluation

    Lawson criterion for ignition exceeded in an inertial fusion experiment

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    For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

    International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

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    Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

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    Development, characterization, and applications of multi-material stereolithography bioprinting

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    AbstractAs a 3D bioprinting technique, hydrogel stereolithography has historically been limited in its ability to capture the spatial heterogeneity that permeates mammalian tissues and dictates structure–function relationships. This limitation stems directly from the difficulty of preventing unwanted material mixing when switching between different liquid bioinks. Accordingly, we present the development, characterization, and application of a multi-material stereolithography bioprinter that provides controlled material selection, yields precise regional feature alignment, and minimizes bioink mixing. Fluorescent tracers were first used to highlight the broad design freedoms afforded by this fabrication strategy, complemented by morphometric image analysis to validate architectural fidelity. To evaluate the bioactivity of printed gels, 344SQ lung adenocarcinoma cells were printed in a 3D core/shell architecture. These cells exhibited native phenotypic behavior as evidenced by apparent proliferation and formation of spherical multicellular aggregates. Cells were also printed as pre-formed multicellular aggregates, which appropriately developed invasive protrusions in response to hTGF-β1. Finally, we constructed a simplified model of intratumoral heterogeneity with two separate sub-populations of 344SQ cells, which together grew over 14 days to form a dense regional interface. Together, these studies highlight the potential of multi-material stereolithography to probe heterotypic interactions between distinct cell types in tissue-specific microenvironments.</jats:p

    Development, characterization, and applications of multi-material stereolithography bioprinting

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    As a 3D bioprinting technique, hydrogel stereolithography has historically been limited in its ability to capture the spatial heterogeneity that permeates mammalian tissues and dictates structure–function relationships. This limitation stems directly from the difficulty of preventing unwanted material mixing when switching between different liquid bioinks. Accordingly, we present the development, characterization, and application of a multi-material stereolithography bioprinter that provides controlled material selection, yields precise regional feature alignment, and minimizes bioink mixing. Fluorescent tracers were first used to highlight the broad design freedoms afforded by this fabrication strategy, complemented by morphometric image analysis to validate architectural fidelity. To evaluate the bioactivity of printed gels, 344SQ lung adenocarcinoma cells were printed in a 3D core/shell architecture. These cells exhibited native phenotypic behavior as evidenced by apparent proliferation and formation of spherical multicellular aggregates. Cells were also printed as pre-formed multicellular aggregates, which appropriately developed invasive protrusions in response to hTGF-β1. Finally, we constructed a simplified model of intratumoral heterogeneity with two separate sub-populations of 344SQ cells, which together grew over 14 days to form a dense regional interface. Together, these studies highlight the potential of multi-material stereolithography to probe heterotypic interactions between distinct cell types in tissue-specific microenvironments

    Quantifying Physician Teaching Productivity Using Clinical Relative Value Units

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    OBJECTIVE: To design and test a customizable system for calculating physician teaching productivity based on clinical relative value units (RVUs). SETTING/PARTICIPANTS: A 550-bed community teaching hospital with 11 part-time faculty general internists. DESIGN: Academic year 1997–98 educational activities were analyzed with an RVU-based system using teaching value multipliers (TVMs). The TVM is the ratio of the value of a unit of time spent teaching to the equivalent time spent in clinical practice. We assigned TVMs to teaching tasks based on their educational value and complexity. The RVUs of a teaching activity would be equal to its TVM multiplied by its duration and by the regional median clinical RVU production rate. MEASUREMENTS: The faculty members' total annual RVUs for teaching were calculated and compared with the RVUs they would have earned had they spent the same proportion of time in clinical practice. MAIN RESULTS: For the same proportion of time, the faculty physicians would have generated 29,806 RVUs through teaching or 27,137 RVUs through clinical practice (Absolute difference = 2,669 RVUs; Relative excess = 9.8%). CONCLUSIONS: We describe an easily customizable method of quantifying physician teaching productivity in terms of clinical RVUs. This system allows equitable recognition of physician efforts in both the educational and clinical arenas

    Educational and Career Outcomes of an Internal Medicine Preceptorship for First-Year Medical Students

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    OBJECTIVE: Medical educators have attempted in recent years to provide quality clinical experiences for medical students early in their medical training. We questioned whether participating in a preceptorship in internal medicine (PIM) resulted in better performances on subsequent clinical rotations and increased interest in internal medicine. PARTICIPANTS: Fifty-four students have participated in the PIM to date, with control groups consisting of students who applied for it but were not selected (n = 36), students participating in a preceptorship in family medicine (n = 168), and the remaining students (n = 330). DESIGN: Prospective cohort study. SETTING: University medical center and community practices. INTERVENTION: A 2-month, clinical preceptorship following the first year of medical school. MEASUREMENTS AND MAIN RESULTS: The following outcomes were assessed: scores in the introduction to clinical medicine course; grades in the medical ethics course; scores from the internal medicine clerkship; and choosing a career in internal medicine. In their second year, PIM students scored higher in both semesters of the introduction to clinical medicine course (87% and 86% vs 84% and 84%, p’s < .01) and were more likely to receive honors in ethics (50% vs 29%, p < .01) than non-PIM students. During the internal medicine clerkship, PIM students’ scores were significantly higher on an objective structured clinical examination (79% vs 76%, p = .05), ambulatory clinical evaluations (80% vs 76%, p < .01), and overall clerkship scores (78% vs 75%, p = .03) but not on inpatient clinical evaluations or on the National Board of Medical Examiners Subject Examination. Preceptorship students were more likely to receive honors grades in the medicine clerkship (33% vs 10%, p < .01), and they were more likely to match into internal medicine residencies than control students (54% vs 27%, p < .01). CONCLUSIONS: The PIM course is an intervention, early in students’ careers, which appears to benefit them academically and increase their interest in internal medicine as a career
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