165 research outputs found

    Examination of Urban Air Mobility Integration into the National Airspace System

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    The Advanced Air Mobility (AAM) initiative aims to enhance air transportation for people and cargo in areas with limited aviation services. The Urban Air Mobility (UAM) concept, under AAM, focuses on improving transportation connectivity within metropolitan areas. The FAA’s ASSURE UAS Center of Excellence has sponsored a project to provide recommendations for future technological developments, UAM airspace integration, infrastructure enhancements, and new regulations to support UAM flights. The team’s first milestone was a literature review to identify past work relevant to UAM, including airspace and operational constraints, infrastructure requirements, and communication, navigation, and surveillance (CNS) requirements. Two dominant concepts of operations were identified, one by the FAA and one by NASA. The team’s second milestone was to examine a UAM corridor concept in Daytona Beach Class C airspace to determine the impact of UAM operations on ATC. The FAA advocates the use of helicopter routes for a measured approach to NAS integration. Since Daytona Class C lacks published helicopter routes, the team developed UAM corridors with input from various airspace users. Key findings suggest a crawl, walk, run development of UAM into Class C airspace is needed, with airspace concepts and system complexities evolving as new UAM features are developed and integrated to meet each UAM Maturity Level

    A Conceptual Model for a Universal Severity of Emergency Report (USER): An Example in Aviation

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    In emergency situations, it is important that information be communicated quickly, concisely, and efficiently. Breakdowns can occur when the receiver of the emergency call does not fully understand the information that the person is sending. The purpose of this paper is to present a new model for enhancing communication between the sender and receiver in emergency situations. The Universal Severity of Emergency Report (USER) is a model designed to be used in emergency situations and convey more information about the current state of the person declaring the emergency than is currently offered by emergency communication channels. USER provides three key pieces of vital information: severity of the situation, capabilities of the sender, and ability to communicate. Severity identifies the level of the emergency on a scale of 1, 2, or 3. Capabilities use the colors white, yellow, and red to indicate the current self-determined capabilities of the individual. Communicate notifies the receiver if the individual is able to communicate or is unable to communicate. This paper presents this concept in an aviation context, but USER has the potential to be used in any number of industries, including medical, military, shipping, transportation, space flight, and law enforcement

    Implicit Racial/Ethnic Bias Among Health Care Professionals and Its Influence on Health Care Outcomes: A Systematic Review

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    Background. In the United States, people of color face disparities in access to health care, the quality of care received, and health outcomes. The attitudes and behaviors of health care providers have been identified as one of many factors that contribute to health disparities. Implicit attitudes are thoughts and feelings that often exist outside of conscious awareness, and thus are difficult to consciously acknowledge and control. These attitudes are often automatically activated and can influence human behavior without conscious volition. Objectives.We investigated the extent towhich implicit racial/ethnic bias exists among health care professionals and examined the relationships between health care professionals’ implicit attitudes about racial/ethnic groups and health care outcomes. Search Methods. To identify relevant studies, we searched 10 computerized bibliographic databases and used a reference harvesting technique. Selection Criteria. We assessed eligibility using double independent screening based on a priori inclusion criteria. We included studies if they sampled existing health care providers or those in training to become health care providers, measured and reported results on implicit racial/ethnic bias, and were written in English. Data Collection and Analysis. We included a total of 15 studies for review and then subjected them to double independent data extraction. Information extracted included the citation, purpose of the study, use of theory, study design, study site and location, sampling strategy, response rate, sample size and characteristics, measurement of relevant variables, analyses performed, and results and findings.We summarized study design characteristics, and categorized and then synthesized substantive findings. Main Results. Almost all studies used cross-sectional designs, convenience sampling, USparticipants, and the Implicit Association Test to assess implicit bias. Low to moderate levels of implicit racial/ethnic bias were found among health care professionals in all but 1 study. These implicit bias scores are similar to those in the general population. Levels of implicit bias against Black, Hispanic/Latino/Latina, and dark-skinned people were relatively similar across these groups. Although some associations between implicit bias and health care outcomes were nonsignificant, results also showed that implicit bias was significantly related to patient–provider interactions, treatment decisions, treatment adherence, and patient health outcomes. Implicit attitudesweremore often significantly related to patient–provider interactions and health outcomes than treatment processes. Conclusions. Most health care providers appear to have implicit bias in terms of positive attitudes toward Whites and negative attitudes toward people of color. Future studies need to employ more rigorous methods to examine the relationships between implicit bias and health care outcomes. Interventions targeting implicit attitudes among health care professionals are needed because implicit bias may contribute to health disparities for people of color

    Racial and Ethnic Differences in Injury Prevention Behaviors Among Caregivers of Infants

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    African American and Latino children experience higher rates of traumatic injury and mortality, but the extent to which parents of different races and ethnicities disparately enact injury prevention behaviors has not been fully characterized. The objective of this study is to evaluate the association between caregiver race/ethnicity and adherence to injury prevention recommendations

    Ring distributions leading to species formation: a global topographic analysis of geographic barriers associated with ring species

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    <p>Abstract</p> <p>Background</p> <p>In the mid 20<sup>th </sup>century, Ernst Mayr and Theodosius Dobzhansky championed the significance of circular overlaps or ring species as the perfect demonstration of speciation, yet in the over 50 years since, only a handful of such taxa are known. We developed a topographic model to evaluate whether the geographic barriers that favor processes leading to ring species are common or rare, and to predict where other candidate ring barriers might be found.</p> <p>Results</p> <p>Of the 952,147 geographic barriers identified on the planet, only about 1% are topographically similar to barriers associated with known ring taxa, with most of the likely candidates occurring in under-studied parts of the world (for example, marine environments, tropical latitudes). Predicted barriers separate into two distinct categories: (i) single cohesive barriers (< 50,000 km<sup>2</sup>), associated with taxa that differentiate at smaller spatial scales (salamander: <it>Ensatina eschscholtzii</it>; tree: <it>Acacia karroo</it>); and (ii) composite barriers - formed by groups of barriers (each 184,000 to 1.7 million km<sup>2</sup>) in close geographic proximity (totaling 1.9 to 2.3 million km<sup>2</sup>) - associated with taxa that differentiate at larger spatial scales (birds: <it>Phylloscopus trochiloide</it>s and <it>Larus </it>(sp. <it>argentatus </it>and <it>fuscus</it>)). When evaluated globally, we find a large number of cohesive barriers that are topographically similar to those associated with known ring taxa. Yet, compared to cohesive barriers, an order of magnitude fewer composite barriers are similar to those that favor ring divergence in species with higher dispersal.</p> <p>Conclusions</p> <p>While these findings confirm that the topographic conditions that favor evolutionary processes leading to ring speciation are, in fact, rare, they also suggest that many understudied natural systems could provide valuable demonstrations of continuous divergence towards the formation of new species. Distinct advantages of the model are that it (i) requires no <it>a priori </it>information on the relative importance of features that define barriers, (ii) can be replicated using any kind of continuously distributed environmental variable, and (iii) generates spatially explicit hypotheses of geographic species formation. The methods developed here - combined with study of the geographical ecology and genetics of taxa in their environments - should enable recognition of ring species phenomena throughout the world.</p

    A pedagogy of friendship: young children's friendships and how schools can support them?

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    Children’s friendships are often neglected by teachers and researchers. This phenomenological study conducted with seven children aged five and six years explores young children’s perceptions of their everyday friendship experiences. This multi-method study used role play interviews, drawings and persona doll scenarios to consider children’s everyday experiences of friendship in school. The paper discusses the importance of socio-cultural aspects of children’s friendship including: imaginary friends; losing friends; protecting time and space to develop friendships and children’s routines and practices as they form and maintain friendships. Data and findings are discussed, leading to an original conceptual framework: a ‘Pedagogy of Friendship’. This is designed to help children make meaning from their friendship experiences and also provide practitioners with the opportunity to nurture and scaffold children through their friendship experiences in schools. We suggest that there is a need to raise the profile of children’s friendships in early childhood education and generate an educational perspective on friendship. Finally we conclude that listening to children’s views of friendship indicates that the application of the framework of a ‘Pedagogy of Friendship’ would be beneficial to children’s all round learning and development. Keywords - children's perceptions, phenomenology, friendship, key stage one, Pedagogy of Friendshi

    Evolution of Blind Beetles in Isolated Aquifers: A Test of Alternative Modes of Speciation

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    Evidence is growing that not only allopatric but also sympatric speciation can be important in the evolution of species. Sympatric speciation has most convincingly been demonstrated in laboratory experiments with bacteria, but field-based evidence is limited to a few cases. The recently discovered plethora of subterranean diving beetle species in isolated aquifers in the arid interior of Australia offers a unique opportunity to evaluate alternative modes of speciation. This naturally replicated evolutionary experiment started 10-5 million years ago, when climate change forced the surface species to occupy geographically isolated subterranean aquifers. Using phylogenetic analysis, we determine the frequency of aquifers containing closely related sister species. By comparing observed frequencies with predictions from different statistical models, we show that it is very unlikely that the high number of sympatrically occurring sister species can be explained by a combination of allopatric evolution and repeated colonisations alone. Thus, diversification has occurred within the aquifers and likely involved sympatric, parapatric and/or microallopatric speciation

    Sexually Antagonistic “Zygotic Drive” of the Sex Chromosomes

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    Genomic conflict is perplexing because it causes the fitness of a species to decline rather than improve. Many diverse forms of genomic conflict have been identified, but this extant tally may be incomplete. Here, we show that the unusual characteristics of the sex chromosomes can, in principle, lead to a previously unappreciated form of sexual genomic conflict. The phenomenon occurs because there is selection in the heterogametic sex for sex-linked mutations that harm the sex of offspring that does not carry them, whenever there is competition among siblings. This harmful phenotype can be expressed as an antagonistic green-beard effect that is mediated by epigenetic parental effects, parental investment, and/or interactions among siblings. We call this form of genomic conflict sexually antagonistic “zygotic drive”, because it is functionally equivalent to meiotic drive, except that it operates during the zygotic and postzygotic stages of the life cycle rather than the meiotic and gametic stages. A combination of mathematical modeling and a survey of empirical studies is used to show that sexually antagonistic zygotic drive is feasible, likely to be widespread in nature, and that it can promote a genetic “arms race” between the homo- and heteromorphic sex chromosomes. This new category of genomic conflict has the potential to strongly influence other fundamental evolutionary processes, such as speciation and the degeneration of the Y and W sex chromosomes. It also fosters a new genetic hypothesis for the evolution of enigmatic fitness-reducing traits like the high frequency of spontaneous abortion, sterility, and homosexuality observed in humans
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