27,845 research outputs found
Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 144
This bibliography lists 257 reports, articles, and other documents introduced into the NASA scientific and technical information system in July 1975
Simulation and Optimization Methods for Assessing the Impact of Aviation Operations on the Environment
There is increased awareness of anthropogenic factors affecting climate change and urgency to slow the negative impact. Greenhouse gases, oxides of Nitrogen and contrails resulting from aviation affect the climate in different and uncertain ways. This paper develops a flexible simulation and optimization software architecture to study the trade-offs involved in reducing emissions. The software environment is used to conduct analysis of two approaches for avoiding contrails using the concepts of contrail frequency index and optimal avoidance trajectories
Aerospace medicine and biology: A continuing bibliography with indexes, supplement 204
This bibliography lists 140 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1980
Assignment of the New Type of Ecological Services for Providing Human Safety Under Conditions of Urban Environment
The main aim of the study is to separate a new category of ecological services for providing human and environmental safety under conditions of accelerated urbanization in the system of eco-services.Urbanization decreased the potential of ecological services and the set of provided functions at the expanse of absorbing essential territories of natural ecosystems and disturbing the ecological balance of the environment. The urbogenic environment that men made and natural dangerous phenomena intensify synergetically in models the new level of threats for both a human and all biotic and abiotic components. There was offered to separate an integral safety service as a new type of eco-services, based on the principle of providing human safety through environmental one. It was demonstrated, that safety services will improve other categories of ecological services, widen the assortment, diversity and mutual dependence of functions. There was presented the succession of steps for identifying and assessing safety services. Indicators and possible types of giving safe and high-quality drinking water to the population were given.The demand for safety services will grow with the development of urbanization processes. Separation and provision of services by functions of the human protection against natural and men made threats increases the total potential of eco-services
Fluid Resuscitation Optimization in Surgical Trauma Patients Utilizing Pulse Pressure Variation and Stroke Volume Variation: An educational module
This quality improvement project seeks to evaluate the knowledge, beliefs, and attitudes of anesthesia physicians on the need of fluid resuscitation and optimization using pulse pressure variation (PPV) or stroke volume variation (SVV) in surgical trauma patients. The intervention will be administered to certified registered nurse anesthetists (CRNAs) and physician anesthesiologists. The sample will consist of roughly ten individuals. A pre-test survey, a virtual educational intervention, and a post-test survey will comprise the project. Utilizing pre- and post-test surveys, the consequences of the intervention will be measured. Additionally, statistical analysis will be used to evaluate the efficacy of the educational intervention. It is anticipated that anesthesia provider education on the efficacy and safety of PPV/SVV-guided fluid resuscitation will provide them with the knowledge necessary to facilitate better surgical trauma patient treatment. As a result, they will be more skilled and effective in assisting patients with surgical trauma to attain euvolemia, hence enhancing the results of perioperative treatment
Aerospace Medicine and Biology: A continuing bibliography with indexes (supplement 274)
This bibliography lists 128 reports, articles, and other documents introduced into the NASA scientific and technical information system in July 1985
MPA network design based on graph network theory and emergent properties of larval dispersal
Despite the recognised effectiveness of networks of Marine Protected Areas
(MPAs) as a biodiversity conservation instrument, nowadays MPA network design
frequently disregards the importance of connectivity patterns. In the case of
sedentary marine populations, connectivity stems not only from the stochastic
nature of the physical environment that affects early-life stages dispersal,
but also from the spawning stock attributes that affect the reproductive output
(e.g., passive eggs and larvae) and its survivorship. Early-life stages are
virtually impossible to track in the ocean. Therefore, numerical ocean current
simulations coupled to egg and larval Lagrangian transport models remain the
most common approach for the assessment of marine larval connectivity. Inferred
larval connectivity may be different depending on the type of connectivity
considered; consequently, the prioritisation of sites for marine populations'
conservation might also differ. Here, we introduce a framework for evaluating
and designing MPA networks based on the identification of connectivity hotspots
using graph theoretic analysis. We use as a case of study a network of
open-access areas and MPAs, off Mallorca Island (Spain), and test its
effectiveness for the protection of the painted comber Serranus scriba. Outputs
from network analysis are used to: (1) identify critical areas for improving
overall larval connectivity; (2) assess the impact of species' biological
parameters in network connectivity; and (3) explore alternative MPA
configurations to improve average network connectivity. Results demonstrate the
potential of graph theory to identify non-trivial egg/larval dispersal patterns
and emerging collective properties of the MPA network which are relevant for
increasing protection efficiency.Comment: 8 figures, 3 tables, 1 Supplementary material (including 4 table; 3
figures and supplementary methods
Exploring Agricultural Production Systems and Their Fundamental Components with System Dynamics Modelling
Agricultural production in the United States is undergoing marked changes due to rapid shifts in consumer demands, input costs, and concerns for food safety and environmental impact. Agricultural production systems are comprised of multidimensional components and drivers that interact in complex ways to influence production sustainability. In a mixed-methods approach, we combine qualitative and quantitative data to develop and simulate a system dynamics model that explores the systemic interaction of these drivers on the economic, environmental and social sustainability of agricultural production. We then use this model to evaluate the role of each driver in determining the differences in sustainability between three distinct production systems: crops only, livestock only, and an integrated crops and livestock system. The result from these modelling efforts found that the greatest potential for sustainability existed with the crops only production system. While this study presents a stand-alone contribution to sector knowledge and practice, it encourages future research in this sector that employs similar systems-based methods to enable more sustainable practices and policies within agricultural production
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