354 research outputs found

    Stomatal Conductance of Malosma laurina in Frequently Burned and Non-frequently Burned Sites

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    In the months following the Malibu fires, the fire zones have experienced and abundance of new growth. Among this new growth, there are differences that can be observed when comparing the top of the Malibu hill (frequent fire zone) to the base of the hill (nonfrequent fire zone). As the chaparral resprouted we noticed the behavior of the Malosma laurina in both frequent and non-frequent fire zones and stomatal conductance, height, and water potential were tested for plants in the two varying zones, with plants in the non-frequent fire zone outperforming their counterparts

    Autonomous Surface Site Establishment to Ensure Safe Crew Arrival and Operations

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    Traditional human Mars missions have relied on crew to support the surface systems. However, for safety, the surface systems will likely need to be setup and capable of operating prior to the arrival of crew. To mitigate risks to the crew, a novel surface architecture has been developed that addresses risks associated with other Mars missions. This architecture relies on a reusable descent and ascent vehicle, extensive in-situ resource utilization, redundant habitation systems, and emerging autonomous capabilities. The resulting surface architecture increases safety for the crew while also providing potential to expand to support longer missions with larger populations in the future

    Drug Combinations as a First Line of Defense against Coronaviruses and Other Emerging Viruses

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    The world was unprepared for coronavirus disease 2019 (COVID-19) and remains ill-equipped for future pandemics. While unprecedented strides have been made developing vaccines and treatments for COVID-19, there remains a need for highly effective and widely available regimens for ambulatory use for novel coronaviruses and other viral pathogens. We posit that a priority is to develop pan-family drug cocktails to enhance potency, limit toxicity, and avoid drug resistance. We urge cocktail development for all viruses with pandemic potential both in the short term (Peer reviewe

    Was COVID-19 associated with worsening inequities in stroke treatment and outcomes?

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    Background COVID-19 stressed hospitals and may have disproportionately affected the stroke outcomes and treatment of Black and Hispanic individuals. Methods and Results This retrospective study used 100% Medicare Provider Analysis and Review file data from between 2016 and 2020. We used interrupted time series analyses to examine whether the COVID-19 pandemic exacerbated disparities in stroke outcomes and reperfusion therapy. Among 1 142 560 hospitalizations for acute ischemic strokes, 90 912 (8.0%) were Hispanic individuals; 162 752 (14.2%) were non-Hispanic Black individuals; and 888 896 (77.8%) were non-Hispanic White individuals. The adjusted odds of mortality increased by 51% (adjusted odds ratio [aOR], 1.51 [95% CI, 1.34-1.69]

    The beginning of time? Evidence for catastrophic drought in Baringo in the early nineteenth century

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    New developments in the collection of palaeo-data over the past two decades have transformed our understanding of climate and environmental history in eastern Africa. This article utilises instrumental and proxy evidence of historical lake-level fluctuations from Baringo and Bogoria, along with other Rift Valley lakes, to document the timing and magnitude of hydroclimate variability at decadal to century time scales since 1750. These data allow us to construct a record of past climate variation not only for the Baringo basin proper, but also across a sizable portion of central and northern Kenya. This record is then set alongside historical evidence, from oral histories gathered amongst the peoples of northern Kenya and the Rift Valley and from contemporary observations recorded by travellers through the region, to offer a reinterpretation of human activity and its relationship to environmental history in the nineteenth century. The results reveal strong evidence of a catastrophic drought in the early nineteenth century, the effects of which radically alters our historical understanding of the character of settlement, mobility and identity within the Baringo–Bogoria basin

    Toward a More Comprehensive Understanding of organizational influences On Implementation: the organization theory For Implementation Science Framework

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    INTRODUCTION: Implementation is influenced by factors beyond individual clinical settings. Nevertheless, implementation research often focuses on factors related to individual providers and practices, potentially due to limitations of available frameworks. Extant frameworks do not adequately capture the myriad organizational influences on implementation. Organization theories capture diverse organizational influences but remain underused in implementation science. to advance their use among implementation scientists, we distilled 70 constructs from nine organization theories identified in our previous work into theoretical domains in the Organization Theory for Implementation Science (OTIS) framework. METHODS: The process of distilling organization theory constructs into domains involved concept mapping and iterative consensus-building. First, we recruited organization and implementation scientists to participate in an online concept mapping exercise in which they sorted organization theory constructs into domains representing similar theoretical concepts. Multidimensional scaling and hierarchical cluster analyses were used to produce visual representations (clusters) of the relationships among constructs in concept maps. Second, to interpret concept maps, we engaged members of the Cancer Prevention and Control Research Network (CPCRN) OTIS workgroup in consensus-building discussions. RESULTS: Twenty-four experts participated in concept mapping. Based on resulting construct groupings\u27 coherence, OTIS workgroup members selected the 10-cluster solution (from options of 7-13 clusters) and then reorganized clusters in consensus-building discussions to increase coherence. This process yielded six final OTIS domains: organizational characteristics (e.g., size; age); governance and operations (e.g., organizational and social subsystems); tasks and processes (e.g., technology cycles; excess capacity); knowledge and learning (e.g., tacit knowledge; sense making); characteristics of a population of organizations (e.g., isomorphism; selection pressure); and interorganizational relationships (e.g., dominance; interdependence). DISCUSSION: Organizational influences on implementation are poorly understood, in part due to the limitations of extant frameworks. to improve understanding of organizational influences on implementation, we distilled 70 constructs from nine organization theories into six domains. Applications of the OTIS framework will enhance understanding of organizational influences on implementation, promote theory-driven strategies for organizational change, improve understanding of mechanisms underlying relationships between OTIS constructs and implementation, and allow for framework refinement. Next steps include testing the OTIS framework in implementation research and adapting it for use among policymakers and practitioners

    The Mock LISA Data Challenges: from Challenge 3 to Challenge 4

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    The Mock LISA Data Challenges are a program to demonstrate LISA data-analysis capabilities and to encourage their development. Each round of challenges consists of one or more datasets containing simulated instrument noise and gravitational waves from sources of undisclosed parameters. Participants analyze the datasets and report best-fit solutions for the source parameters. Here we present the results of the third challenge, issued in Apr 2008, which demonstrated the positive recovery of signals from chirping Galactic binaries, from spinning supermassive--black-hole binaries (with optimal SNRs between ~ 10 and 2000), from simultaneous extreme-mass-ratio inspirals (SNRs of 10-50), from cosmic-string-cusp bursts (SNRs of 10-100), and from a relatively loud isotropic background with Omega_gw(f) ~ 10^-11, slightly below the LISA instrument noise.Comment: 12 pages, 2 figures, proceedings of the 8th Edoardo Amaldi Conference on Gravitational Waves, New York, June 21-26, 200

    How should the advent of large language models affect the practice of science?

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    Large language models (LLMs) are being increasingly incorporated into scientific workflows. However, we have yet to fully grasp the implications of this integration. How should the advent of large language models affect the practice of science? For this opinion piece, we have invited four diverse groups of scientists to reflect on this query, sharing their perspectives and engaging in debate. Schulz et al. make the argument that working with LLMs is not fundamentally different from working with human collaborators, while Bender et al. argue that LLMs are often misused and over-hyped, and that their limitations warrant a focus on more specialized, easily interpretable tools. Marelli et al. emphasize the importance of transparent attribution and responsible use of LLMs. Finally, Botvinick and Gershman advocate that humans should retain responsibility for determining the scientific roadmap. To facilitate the discussion, the four perspectives are complemented with a response from each group. By putting these different perspectives in conversation, we aim to bring attention to important considerations within the academic community regarding the adoption of LLMs and their impact on both current and future scientific practices

    Moyal star product approach to the Bohr-Sommerfeld approximation

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    The Bohr-Sommerfeld approximation to the eigenvalues of a one-dimensional quantum Hamiltonian is derived through order â„Ź2\hbar^2 (i.e., including the first correction term beyond the usual result) by means of the Moyal star product. The Hamiltonian need only have a Weyl transform (or symbol) that is a power series in â„Ź\hbar, starting with â„Ź0\hbar^0, with a generic fixed point in phase space. The Hamiltonian is not restricted to the kinetic-plus-potential form. The method involves transforming the Hamiltonian to a normal form, in which it becomes a function of the harmonic oscillator Hamiltonian. Diagrammatic and other techniques with potential applications to other normal form problems are presented for manipulating higher order terms in the Moyal series.Comment: 27 pages, no figure
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