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Seed-source environment predicts drought response for a priority restoration species, Plantago patagonica
No full textIn drylands of the Southwestern United States, drought is a common disturbance. However, the intensity, duration, and severity of drought is increasing because of anthropogenic climate change. Restoration efforts are often thwarted by drought induced effects on plant germination, survival, and reproduction, and we expect these challenges to exacerbate restoration failure in the future. The careful selection of plant materials to match the future environment may be one way to improve restoration success under climate change. Here, we focus on a priority restoration species in the arid southwestern United States, Plantago patagonica sourced from environments that differ in rainfall variability. With a combination of greenhouse and common garden experiments, we quantified how collection site temperature, precipitation, and variability in precipitation impacted performance in twelve populations of P. patagonica under experimentally imposed drought conditions. We found that seeds sourced from variable precipitation environments have higher adult mortality (p < 0.01, R2c=0.09, R2m=0.24), higher SLA (p < 0.05, R2c=0.22, R2m=0.36), and larger total biomass (p < 0.05, R2c=0.08, R2m=0.28) under experimental drought. Contrary to expectations, these results suggest that consistent and predictable precipitation regimes have prepared populations of Plantago patagonica to survive in drought conditions. We also find that spring temperature and rainfall of seed source locations impact performance, drought response, and plasticity for P. patagonica. We suggest that the consideration of seed source rainfall variability, temperature, and precipitation in wild seed collection efforts for ultimate use in restoration can improve the success of restoration projects in arid lands under climate change
Beware of despair: embracing fear and hope in climate journalism
No full textSince the mid-20th century, the effects of climate change have worsened around the world, from major temperature fluctuations and sea level rise, to extreme weather events like wildfires, hurricanes and drought (NASA, 2021). Climate scientists have warned of climate change for many years, but the message has fallen upon deaf ears. Climate journalism is media coverage of climate-related events, stories and impacts and has been common in mainstream media since 1988. There has been an increase in this type of journalism in recent years as people become more aware and alarmed. Much of this coverage is fear-based and does not provide much hope for the future, which has proven to be unproductive, and does not inspire the pro-social behaviors necessary for climate change mitigation. The following case study analyzes media coverage of the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), published in August of 2021. The discourse and image analysis found that 55% of articles were fear-based, 24% were balanced between hope and fear and 21% were hope-based articles. To conclude are recommendations for climate journalists informed by Ajzen and Fishbein’s (1980) theory of planned behavior, Azjen’s (1991) theory of reasoned action, Petty and Cacioppo’s (1986) elaboration likelihood model, and McCombs and Shaw’s (1972) agenda setting theory
High throughput, reliable, and secure password management system using physical unclonable functions
No full textInsider attacks capable of diverting databases (DBs) of passwords (PWs) are a significant risk. This risk cannot be mitigated by turning PWs into digests with salted hashing schemes. Converting digests to PUF responses via low-cost memory PUFs and constrained hardware (HW) is attractive because DBs cannot be exploited without PUF control. Even though PUFs provide an additional layer of security, PUFs are slow for PW managers (PWMs). For systems with a large number of users, this can be a serious issue. Furthermore, the resiliency of PUFs, like that of any other piece of HW, can be a source of concern. As a result, accepting the concept of a PUF-based PWM system requires a trade-off between achieved security and desired throughput and resiliency. This dissertation investigates how PUF-based PW managers might be brought closer to reality, with a focus on throughput and reliability. Several methods and architectures are proposed and evaluated to improve the PUF-based PWMs' resiliency, latency, or both. The proposed solution involves implementing a high-throughput architecture with PWM nodes controlled by a dispatcher that distributes the central DB and tasks to all PUF-based PWM nodes. The concept of high throughput, resilient, and secure PWM system with multiple PUFs is tested and evaluated on a prototype consisting of four PWM nodes to overcome the latency constraint caused by PUFs. A PWM node receives user information from the dispatcher and outputs the authentication result. A PWM node is implemented using a low-cost microcontroller, extremely low-cost SRAM PUF, and a non-volatile memory. The experimental results of this work show functionality of PUF-based PWM systems as the number of PUF-based PWM nodes increases. The findings of this study can help mitigate one of the critical cybersecurity attacks that may be utilized in various real-world situations
An experimental approach to PaleoAmerican petrified wood procurement and heat-treatment at the Rainbow Forest archaeological locality
Get PDFArchaeological investigations by Northern Arizona University in the Rainbow Forest Locality identified two possibly heat-treated petrified wood artifacts, including a Clovis point fragment, which offers important insights into PaleoAmerican resource use and settlement. This thesis provides additional evidence for Clovis-age petrified wood heat-treatment activities in the Rainbow Forest Locality at the Petrified Forest National Park in northeastern Arizona. This evidence is supported by an experimental pilot project examining the effects of heat-treating Rainbow Forest petrified wood to 1) create a comparative collection that can be used to identify heat-treated petrified wood in the archaeological record; and 2) assess the flintknapping characteristics of untreated and heat-treated petrified wood. Experimental archaeology examining the possibly heat-treated petrified wood artifacts from the Rainbow Forest Locality yields evidence that Clovis peoples were engaging in lithic heat-treatment activities in the Southwest. Examining Clovis heat-treatment lithic manufacturing techniques in the Rainbow Forest Locality offers archaeology information on Clovis resource use, local adaptation, regional mobility, and lithic technology that can be applied to the greater Southwest region of the United States
Evaluation of the relationship between higher education institutions in the United States and their international recruitment agents
No full textStudent mobility has increased significantly in the last two decades. With the United States as the most popular location in the world for international students, recruitment of this student population became a priority for many institutions of higher education. The use of international student recruitment agents has become a common practice among institutions that pursue this market. The purpose of this study was to evaluate the effectiveness of partnerships between international student recruitment agents and institutions of higher education, to understand what makes them successful business partners, and to learn how to improve these partnerships.The findings suggest that channels of communication between institutions of higher education and international student recruitment agents ought to improve so they can support and represent each other properly. Furthermore, standardizing onboarding processes as well as agent professional certifications play a crucial role in maintaining high standards of ethical practices. Finally, regulating agent-institution collaboration would ensure they serve students efficiently
Setting an interim leader up for success
No full textHigher education is experiencing leadership turnover and during these transitions colleges and universities are relying on interim leaders to fill this leadership gap. The purpose of this study was to identify ways to support interim leaders and leverage their experience into the development of professional growth opportunities at a large community college district in the Southwest United States to be referred to as Canyon Road Community College District (CRCCD).
Participants included academic leaders currently serving or have served in an interim role within the last two years from 2019 – 2021, who have served for at least one full academic semester (i.e., 16 weeks), and are current and/or past interims in various roles throughout the organization such as but not limited to provost, president, vice-president of academic and student affairs, senior associate vice-president, deans, associate vice-presidents, associate deans, and directors. The design of this qualitative study utilized data collected, transcribed, coded, analyzed, and summarized from in-depth semi-structured personal interviews with 11 academic leaders.
The findings of this study suggested the need for various supports: onboarding and training, mentoring or coaching, and if allowed the opportunity to shadow the outgoing leader that would be beneficial for interim leaders to be successful in their temporary role. There is also evidence that the length of time of serving in an interim role needs to be addressed
Ecological effects of seed harvesting ants on rangeland plant communities
No full textHarvester ants play important ecological roles through nest construction and trophic interactions, considered by many to be keystone species. Yet they have historically been labeled as pests and persecuted within their native ranges. This dissertation focuses on understanding beneficial and detrimental roles of harvester ants to human activities and rangeland ecosystems. I review the literature focusing on support or lack of support for keystone and pest effects of harvester ants in rangeland habitat. Harvester ants perform beneficial roles such as: a) nest rims serving as refugia for plants thereby increasing ecosystem stability, b) the dispersal or consumption of seeds, and c) trophic roles such as predation of arthropod and prey to insectivores. Oppositely most detrimental roles had little to no scientific support, instead stemming from anecdotes or assumption. The only detrimental role that potentially justifies eradication of harvester ants in rare cases is the powerful sting of some species. However, other roles of harvester ants are recently discovered and require more study to clarify the beneficial or detrimental effects to human activities. I investigated the roles of harvester ants in structuring vegetation through nest-construction and seed harvesting. Harvester ants enhanced both native and invasive plant species along their nest rims. Harvester ants preferred a variety of native grass seeds but rejected seeds from other species. These findings are important for broadcast seeding and invasion dynamics in areas with high densities of harvester ants. Harvester ants have been accused of causing degradation because their nest densities may be increased from disturbances such as grazing, although in these cases they are a symptom not cause of ecosystem disfunction. I investigated how human activities change harvester ant nesting densities. The presence of hiking trails increased nest densities, while grazing decreased them. These results underscore the roles human activities have in either promoting or decreasing abundances of ants. Overall, the few detrimental roles of harvester ants seem easily mitigated and none support persecution of harvester ants as pests, while the strong support for their roles as keystone species indicate the importance of their conservation
The relationship between sense of belonging to calculus and persistence for community college students
No full textAs the demand for qualified science, technology, engineering and mathematics (STEM) and business college-degreed workers increases, underrepresented minorities, females, first-generation college students, and students who are economically disadvantaged remain as four high-risk STEM populations. A majority of undergraduate STEM and business programs require calculus, an advanced course in mathematics. However, students who cannot pass the required math courses must change their academic plans, making calculus a gatekeeper to high-income yielding careers in both STEM and business.
Research suggests that a sense of belonging to an academic domain, specifically calculus, has an influence on students’ persistence and academic achievement. This research study seeks to obtain a better understanding of the relationship between sense of belonging to calculus and persistence for students at Brightside Community College, a two-year Hispanic-Serving and Minority Serving Institution located in the southwestern United States. The primary research question was: To what extent does a sense of belonging to calculus influence the persistence and academic achievement of students at Brightside Community College? In a mixed-methods study, the researcher used the Sense of Belonging to Calculus quantitative survey to investigate any differences in sense of belonging among six different groups. The six groups were course delivery mode, academic program, level of economic pressure, ethnicity, gender, and first-generation college student. The researcher also used qualitative data in the form of individual student interviews to complement the survey data and investigate how students at the college attain a sense of belonging to calculus.Data from the survey and the interviews were combined to provide some understanding about the research population. The findings in this study indicate that students who are under high economic stress have numerous challenges attaining a sense of belonging to calculus, pulling their time and effort away from schoolwork and delaying their academic plans. Although the students in this study indicated a willingness to persist and complete their college degree, much of their time that could have been dedicated to schoolwork was instead diverted to difficult issues related to food, housing, and safety
Rules of academic writing: a synchronic and diachronic corpus analysis across the disciplines
No full textStandards of academic writing are documented in style guides adopted by academic disciplines, style guides such as the Publication Manual of the American Psychological Association and Scientific Style and Format. Some of the standards in these style guides are expressed as prescriptive or proscriptive rules that provide academic writers with language advice. Regarding such prescriptive and proscriptive rules, this dissertation has two goals: (i) to identify and describe the body of rules that form standard academic writing and (ii) to examine whether such rules matter; that is, whether they are followed in current academic writing and whether adherence to such rules has changed over time.
To accomplish the first goal, six style guides adopted by academic disciplines were analyzed to identify rules. The identified rules (n = 537) were categorized by their aim (e.g., promoting clarity, removing bias), linguistic category (e.g., lexical, grammatical), and the disciplines for which they are intended, among others. These basic categorizations revealed contradictions in how prescriptive and proscriptive rules are traditionally viewed in the linguistics community. Prescriptive and proscriptive rules are often referred to as “grammar rules,” but the vast majority of the rules are, surprisingly, about lexis. As discussed by Curzan (2014), rules are often associated with arbitrary judgements regarding what constitutes “correct” or “standard” language, but rules can also be motivated by desirable values in writing such as clarity, concision, and bias-free language. Such basic categorizations and descriptions show the various layers of rules, furthering our understanding of rules and their study as a sociolinguistic phenomenon.
To accomplish the second goal of the dissertation, 155 rules were analyzed in a corpus of reputable journal article writing in four disciplines (i.e., biology, history, psychology, mechanical engineering) during two periods (i.e., 1950, 2020). The corpus included 17,085 articles with 117,707,019 words. The corpus analyses provided insights into (i) which rules are violated more versus less often, (ii) what characteristics are shared by rules that tend to be violated more often, and (iii) which rules will likely continue to be followed or violated. A few of the major findings are as follows: (i) lexico-grammatical or grammatical rules are generally violated more often than lexical rules; (ii) surprisingly, some bias-free language rules are violated (e.g., the use of the biased terms opposite gender, opposite sex, and chairman); (iii) current academic writing violates the rules that proscribe the dense use of nominalizations, long noun-noun sequences, and adverbial uses of based on, and there is a considerable increase in the frequency of these features from 1950 to 2020, indicating that the rules proscribing these features will likely continue to be violated; (iv) academic writing in biology, psychology, and mechanical engineering include fewer agentless passive voice constructions in 2020 compared with 1950, and this decrease in the frequency of passive voice constructions is related to the increase in the use of the first-person pronoun we; and (v) the proscribed use of the relative pronoun which in restrictive relative clauses is mostly followed by academic writers, and adherence to this proscription has increased from 1950 to 2020. The findings of the dissertation have implications for the study of prescriptivism as a sociolinguistic phenomenon and for anyone involved in the writing, teaching, and/or editing of academic writing
Literacy instruction for English learners with extensive support needs
No full textThe current study examined the effects of a shared reading instructional package on literacy instruction for multilingual learner (MLL) students with extensive support needs (ESN). Three participants, from kindergarten through 5th grade, received the intervention. To establish experimental control, the researchers used a multiple probe design with conditions (i.e., phonics sets) and replicated across participants. Based on the multiple probe design and visual analysis, results showed all students met criterion across all phonics sets. In addition, all participants made considerable progress on secondary variables to include phonemic awareness, fluency, vocabulary, and comprehension. Furthermore, students were able to generalize their knowledge of decoding words. Considerations in interpreting the results for classroom implementation and future research are discussed