1925 research outputs found
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Experimental performance analysis of physically unclonable session key protocol for zero-trust environments
No full textThis article describes a protocol which mitigates the possibility of fraudulent server-side man-in-the-middle attacks on client-server architectures by exploiting physically unique properties of hardware memory devices known as Physically Unclonable Functions (PUFs). We then provide an analysis of the performance of an experimental implementation of the protocol using two different types of PUF in many different configurations, followed by a discussion of the conclusions and practical considerations implied by the preceding analysis
Entangled resistance: capacity to radically imagine through the art of countermapping
No full textThe web of possibility expands when we begin to imagine the once unimaginable. What does it look like to challenge the way we individually imagine our communities and our internalized hierarchies of representations? This thesis is an artistic inquiry that engages with social struggle, utilizing an arts-based methodology to create visibility for that which has only existed in the margins of occupied Flagstaff and to oppose what current power structures want us to believe to be unchangeable, through the example of first transforming ourselves as individuals. Coronavirus spread around the world, seeping a strange collective unrest into the forefront of our minds. Our bodies are political. The spaces through which we move are political. The streets we march in are political. The pandemic revealed there is no escaping the ways in which we embody the societies we live in. This thesis is a countermap, born of one person’s imaginings of a place but is influenced by participation in mutual aid at a time when government and capitalism were failing us; when a militant critique of neoliberal policies became mainstream. Bridging the gap between the abstract and the planned, countermapping can be an incredible tool for expanding our capacity to imagine meaningful changes to the spaces through which we move and embody. It is a reclamation of place in response to how maps have historically been used by colonizing forces to seize and redistribute land and exclude BIPOC from thriving. This countermap is a large-scale mixed media painting that explores what was, at the height of the pandemic in occupied Flagstaff, and what could be, in the following twenty years, if we continue the work of resisting a violent and destructive status quo. The map is based on autoethnographic accounts of my participation in local mutual aid efforts during COVID-19 and the following process of reinvigorating my imaginative capacity through arts-based inquiry. It is an example of the power of our imaginations to incubate the seeds of possibility within us as individuals first and to build our capacity to arrive in community transformed, ready to participate holistically and relentlessly
Trust monitoring framework in autonomous unmanned aerial systems
No full textMulti-Agent Systems (MAS) refers to a system of several agents that interact to solve problems beyond each agent's individual capacities or knowledge. One example of MAS is unmanned aerial vehicles (UAVs). UAVs are widely used in several civilian and military operations, including remote sensing, surveillance, package delivery, disaster relief, and medical services. Due to their unique features, such as high mobility, ease of deployment, and ability to hover, UAVs can provide urgent Internet and communication services in time-critical missions or natural disasters. On the one hand, the UAVs are vulnerable to several attacks, including cyberattacks such as false data injection, physical attacks such as targeting the UAVs using firearms, and cyber-physical attacks such as GPS spoofing. On the other hand, in MASs, the agents need to rely on one another’s services and resources to perform their tasks. Any malicious behavior accordingly may lead to serious system breakdown in the long term. Therefore, developing robust trust monitoring mechanisms to identify potential attacks on these systems is crucial. The aim of this project is to develop a distributed trust management framework approach to solve this problem
Evaluating the co-occurrence and exchangeability of adverse childhood experiences in 21 states
Get PDFSmoking is the leading cause of preventable disease, disability, and death in the US. There is strong evidence that current smoking is associated with adverse childhood experiences (ACEs), traumatic events that occur in childhood. This association is observed when comparing smoking prevalence across a cumulative exposure variable representing the number of ACEs experienced. However, no research to date has described specific ACE exposures, both individually and in combination, within a given cumulative count of adversities. Additionally, there is a recognized but largely untested assumption that individual ACEs (and ACE exposure categories) are equally prognostic for given health outcomes. Evaluating this assumption requires partitioning individual ACE exposures within each cumulative risk category. The first objective of this study was to partition the composition of individual ACE exposures within cumulative risk categories. The second goal was to evaluate the exchangeability assumption of the cumulative categorical risk model by comparing the individual ACE exposures that comprise a singleton and pair ACE category. In a national sample of 115,230 adults across 21 states, divorce, verbal abuse and physical abuse were the most common elements of singleton ACE exposures, and heterogeneity was observed for smoking prevalence, where persons experiencing divorce (18.7%) had substantially higher smoking prevalence than persons experiencing verbal abuse (11.5%) despite exposure to a single adversity. No heterogeneity was observed among the top three pairwise ACE clusters. This study provides evidence that individual ACE exposures are not exchangeable in terms of their association with smoking. The approach to partitioning ACE clustering described here provides a foundation for further evaluation of ACE exchangeability within higher cumulative exposure categories and among different health outcomes
Professional identity, career satisfaction, and occupational commitment of dental hygiene educators
No full textThe past two decades have emphasized the growth in popularity and community need for the dental hygiene profession in the United States. However, the shortage of dental hygiene educators has also been growing over the past 20 years. Reasons for this continued shortage have not been fully explored. Through an explanatory mixed methods design, this study examines the professional identity, career satisfaction, and occupational commitment of dental hygiene educator within the United States. I analyzed data from a survey to assess if professional identity and career satisfaction impacted dental hygiene educators’ commitment to staying within academia. Data was collected from 141 dental hygiene educators who were employed full-time and taught didactic courses at accredited colleges and universities in the United States. Professional identity was examined utilizing the Professional Teacher Identity Scale, the Minnesota Satisfaction Questionnaire was used to determine career satisfaction, and occupational commitment was measured with the TCM Employee Commitment Survey. Survey findings revealed that professional identity and career satisfaction have no significant bearing on occupational commitment. Focus groups were also conducted to identify how educators perceived their professional identity and what may have influenced that perception. Twelve dental hygiene educators were interviewed and all of them identified as educators and not solely as dental hygienists. Common influences on their identity were education and experience, while a lack of administrative support was seen as a barrier to identity formation, and an increase in education and training was seen as a way to develop their identity as educators. Further investigation into training programs tailored to improve the professional identity and increase the retention of dental hygiene educators is recommended. Overall, the results in this study underscore the relationship between professional identity and career satisfaction, and school administration should further explore ways to enhance dental hygiene educators’ professional identity to increase their career satisfaction
Amino acid geochronology of foraminifera from the central Arctic Ocean and Nordic Seas
No full textAccurate geochronology of Arctic Ocean Quaternary sediments is needed in order to properly investigate paleoclimatic and palaeoceanographic changes that have occurred in the region. Common Quaternary marine geochronologic methods such as oxygen isotope and paleomagnetic reversal stratigraphy are challenging to use in the Arctic Ocean, however. The extent of amino acid racemization (AAR) in foraminifera is a promising geochronological tool in the Arctic Ocean, although previous studies have highlighted anomalously high rates of racemization there compared to those from other oceans. Additionally, high intrasample variability limits the accuracy of the method as applied to foraminifera. To address these issues, this thesis presents data from AAR analysis conducted on Neogloboquadrina pachyderma samples ranging in age back to 780 ka from five sediment cores from the central Arctic Ocean and five cores from the Nordic Seas. The Nordic Seas samples were analyzed to further evaluate the validity of the AAR method as applied to cold-water sites where the cores are well dated using conventional methods. The central Arctic Ocean samples were analyzed to test the reproducibility of the apparent high rate of racemization in the region. The subsample rejection rate and coefficient of variation (CV) values for the samples were used to quantify intrasample variability. Scanning electron microscopy (SEM) imaging was conducted on Nordic Seas and central Arctic Ocean N. pachyderma tests to see if intrasample variability was associated with visibly altered tests. Neogloboquadrina pachyderma were extracted from a total of 86 samples and subdivided into 784 subsamples, most of which comprised 8 to 10 individual foraminifera tests. Subsample rejection rates and CV values for samples were comparable to those of previous AAR studies on foraminifera, with 27% of the subsamples rejected based on conventional data-screening procedures. SEM analysis of the tests did not detect widespread visual evidence of incomplete cleaning or alteration features that could readily be associated with high intrasample variability, though it did identify a sample with overall poor test preservation. All examined tests exhibit thick calcite encrustations, but their effect on intrasample variability is uncertain. The utility of the AAR geochronology method is reaffirmed for independently dated cold-water sites using the Nordic Seas data. Further, the apparently high rate of racemization was reproduced in the central Arctic Ocean samples. While the cause for this apparent high rate is unclear, my preferred explanation is that the currently accepted ages for the central Arctic Ocean samples are too young. An alternative age model extending back to 400 ka is proposed based on a simple linear sedimentation rate as indicated by AAR-derived ages using an existing AAR age equation from multiple cold-water sites globally
Soil, plants and the biocrust between: innovations in Mojave Desert restoration and management
No full textThe Mojave Desert is home to a diverse community of organisms with varying strategies to thrive in harsh abiotic conditions but are threatened by anthropogenic disturbances. This includes biological soil crusts (biocrusts) that inhabit the soil surface in arid landscapes, providing vital ecosystem services. Restoration of biocrusts to degraded ecosystems is both a goal in and of itself and a possible tool to boost ecosystem function and habitat quality, improving overall restoration outcomes. This research focuses on answering practical questions to inform restoration practitioners on best practices to assist recovery of biocrusts, while also investigating the if biocrust can be used to support desirable changes in the vascular plant community. As restoration often uses multiple techniques simultaneously, land managers need to know how biocrust restoration actions integrate with other commonly used methods before deploying biocrust broadscale. To address this knowledge gap, we tested for potential conflicts with invasive plant management as well as potential positive interactions with vascular plant focused restoration practice. In a greenhouse experiment, we found that herbicides from the synthetic auxin family can likely be used alongside biocrust additions while commonly used herbicides such as glyphosate may damage biocrust organisms. In a factorial, blocked field experiment in gypsum soils of the Mojave Desert we found that active restoration of biocrust and vascular plants is both needed and effective for enhancing these communities in a three-year timeframe. However, combining biocrust inoculation and direct seeding of vascular plants did not increase the success of either treatment.
We further tested for beneficial interactions between biocrust and the endangered Arctomecon californica. We found no evidence for a relationship between A. californica and biocrusts or other organisms but did make advances in methods for salvage, direct seeding, and ex situ cultivation of this rare plant. Research on A. californica has been stymied by the inaccessibility of much of the previous work, which has remained unpublished and, in some cases, undigitized. We provide a detailed summary of all available information about A. californica to ensure that no knowledge is lost and ensure both researchers and land managers can make informed decisions regarding conservation of this species
Discourse within southwest water management: a case study in the Central Arizona Project
No full textThe Central Arizona Project (CAP), a system of canals developed under the Colorado River Basin Project Act of 1968 that provided water to central and southern Arizona, is the primary water supplier for over 80 percent of the population in the state. With growing communities and already scarce water resources, addressing climate change is important within the discussion of water management and the broader water-energy-food-climate (WEFC) nexus. This study asks: How does discourse on water availability in the context of drought/climate change/global warming influence the policies and procedures of the Central Arizona Project? To answer this question, the study employs a discourse and content analysis of 221 CAP board meetings to understand how the discussion of climate change has changed over time and guiding motivations of CAP governance. A political ecology lens was taken to reveal the social and political relations of the water-energy- food-climate nexus. While the discussion of climate change within CAP board meetings has increased in frequency with decreasing levels of resistance, these discussions do not fully encompass the full extent of climate change. Results from both the content analysis and discourse analysis reveal the key motivating factors behind CAP board meetings as well as individual sentiments CAP members and the included external individuals feel towards climate change, including economic development and agriculture. These show gaps and biases within CAP discussions, ultimately pointing towards opportunities for growth when it comes to building sustainable communities within the realm of water management. Suggestions for future CAP actions include continuing to raise awareness on climate change and resource availability while limiting overall consumption
Lived experiences of women of color in educational leadership in Arizona
No full textThe purpose of this study was to explore the lived experiences of women of color in K-12 public school district administration positions in order to gain insight on the conditions that need to be present for women of color to obtain longevity and professional success as well as to gain a better understanding of the specific barriers women of color encounter when pursuing leadership positions in order to provide K-12 public school districts’ human resources departments with guidance on developing policies and protocols to attract and retain a more diverse leadership team.Participants included in this phenomenological study were individuals who identify as women of color and have held an administrative position at the district level in an Arizona K-12 public school district for a minimum of two years. Although it was planned to include seven to 12 participants in this study, the sensitive nature of the subject combined with the extremely small population size reduced the participant sample to four.
Research question one addressed the perceived barriers faced by women of color in educational leadership in Maricopa County school districts. Participants perceived challenges related to access to opportunities beginning early in their lives, surfacing as being precluded from expectations around college participation and degree attainment. The lack of expectations was a common thread among all four participants; despite this lack of expectations, each participant managed to blaze a trail to ultimately attain advanced degrees.
Research question two explored the ways gender and race intersect and impact women of color in leadership positions. For each of the participants, similarities of experience were extracted based on their responses to the interview questions. Despite the differences in origination, upbringing, family values, and professional pathways, the parallel experiences recalled allowed for meaningful connections in challenges encountered, tactics employed, and systemic issues identified by each despite existing in separate organizations across Maricopa County, Arizona.
Research question three addressed the policies and protocols school districts can employ to attract and retain candidates of color. Each participant expressed some variation of concern over the lip service that school districts provide around the topic of attracting and retaining a diverse work force at multiple levels of their organization
The bidirectional relationship between physical activity and stress in working parents
Get PDFPhysical activity is widely known to have many physical and mental health benefits. Despite this, a large portion of the population fails to engage in regular physical activity. One commonly reported barrier to physical activity is stress. However, stress has also been shown to decrease when engaging in physical activity. Working parents are a subpopulation that has a relatively high risk for stressor exposure and limited available free time to engage in physical activity. Limited research has attempted to untangle the day-to-day associations between physical activity and stress among a working parent population. The purpose of this study is to examine the bidirectional relationships between daily physical activity and stressor frequencies and severity within working parents using a microlongitudinal approach, while simultaneously assessing differences between mothers and fathers. Using a subsample of 667 working parents (47.7% female, Mage 43, 81% married, 84.9% White) from the National Study of Daily Experiences, structural equations modelling was used to examine the dynamic links between daily stressors and physical activity. Overall, the models for fathers were not deemed a good fit, however, the models for mothers did have adequate fit. The measurement paths from the latent variables to their respective variables were significant, whereas the vast majority of the structural relations between physical activity and stressors were not significant. Due to poor fit for fathers’ models, no conclusions can be made. It appears that daily physical activity and daily stress (both number of stressors and perceived severity) are not related among working mothers. Further, these findings suggest that for working mothers, encountering a stressor on one day may not be detrimental to the amount of physical activity that they perform the next day. And, if physical activity engagement is low on one day, both the number of stressors and their severity appear not to increase. Results of the aggregated linear regressions were not significant for number of stressors or the severity, providing further evidence for a lack of relationship between the variables. Future research should examine daily links between physical activity and stress among fathers utilizing a different model. Given the non-predictive relationships, future work should also examine the different methods for reducing daily stress and their severity among working parents