1925 research outputs found
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Holocene hydroclimate in southern and arctic Alaska inferred from diatom oxygen isotopes and data – model comparisons
No full textRapid anthropogenic warming in Alaska is causing drastic changes to the region’s hydroclimate, as evidenced in part by melting glaciers, diminishing sea ice, and changing precipitation patterns. These rapid changes are superimposed upon the naturally occurring, long-term variability characteristic of ocean and atmospheric systems in the North Pacific and Arctic Ocean basins. One particularly important source of natural climate variability in this region is the Aleutian Low, an atmospheric pressure cell that modulates the paths of winter storms in the Gulf of Alaska and Bering Sea. The influence of the Aleutian Low on terrestrial hydroclimate is well documented on intra- and interannual timescales over the instrumental period in southern Alaska, and to some degree in Arctic Alaska. However, Aleutian Low variability on centennial to millennial timescales remains uncertain over the course of the current interglacial period (the Holocene); the findings of existing reconstructions contradict one another, and few studies address the pressure cell’s influence on past hydroclimate in northern Alaska. Furthermore, there is evidence that suggests the presence of modern teleconnections between variability in the extent and duration of Arctic sea ice and lower latitude circulation, including the Aleutian Low. However, no studies have interrogated such a teleconnection through the Holocene. In addition to these dynamical uncertainties, efforts to reconstruct past hydroclimate are complicated by the challenges of deciphering a climate signal from proxy systems, particularly those pertaining to oxygen isotopes, which are influenced by numerous climate and environmental variables.To improve our understanding of Holocene hydroclimate variability in sub-Arctic and Arctic Alaska, I have used a variety of approaches focused on lacustrine diatom oxygen isotope datasets and model experiments. These approaches include: 1) multi-proxy paleoclimate analyses conducted on lake sediments collected at individual sites; 2) comparing proxy datasets at neighboring sites; 3) compiling and synthesizing paleoclimate datasets across Alaska and neighboring lands and oceans; 4) comparing modern observations and paleo data with output from a coupled ocean-atmosphere general circulation model; and 5) interpreting paleo oxygen isotope data using a simple hydrologic and isotope mass balance model.
Results from this dissertation support a growing body of evidence that the Aleutian Low strengthened between the middle and late Holocene (around 5 – 4 ka cal BP), and suggest this change may have occurred concomitant with an increase in the annual duration and extent of sea ice in the western Arctic Ocean. This finding indicates that the observed modern relationship between North Pacific atmospheric circulation and high latitude hydroclimate is a more persistent feature of Holocene hydroclimate than was previously demonstrated. Finally, my results reveal that these synoptic-scale influences on hydroclimate are not always evident at individual sites, because site-specific factors can dampen a regional climate signal. In particular, I demonstrate the importance of groundwater derived from receding glaciers in the hydrologic and isotope mass balance of lakes adjacent to mountain glaciers, which is an often over-looked component of paleoenvironmental reconstructions from lacustrine oxygen isotope datasets. In light of these findings, valuable future research directions for Alaska’s Holocene hydroclimate include: 1) developing methods to identify the influence of synoptic-scale climate influences on lake water isotopes; 2) proxy system modeling, and corresponding monitoring studies; and 3) the development and application of simplistic modeling frameworks
The impact of instructional model and instructor experience and rank on university level precalculus grades
No full textThis descriptive-comparative study investigated the impact of different instructional models on a university level Precalculus course on students’ achievement. Participant data (N=14,993) was collected from Fall 2008 to Spring 2019 and categorized into four different instructional models: traditional, modular, emporium v.1, and emporium v.2. This study discovered that instructional model was a significant predictor of students’ achievement in a university level Precalculus course. Data on students’ achievement in Calculus I, the subsequent course, was collected and analyzed. Significant association existed between the instructional models in the Precalculus course and students’ achievement in Calculus I. This study found that the modular model had higher students’ success in both Precalculus and Calculus I, in comparison to the traditional and emporium models. Furthermore, instructor experience, measured through instructor rank, was another variable analyzed in this study. Statistical analyses showed that instructor rank was a significant predictor of students’ achievement in the Precalculus course. The data analysis estimated that students were more likely to earn a passing grade in the Precalculus course when they were taught by a faculty with a lecturer rank in comparison to professor, instructor, Graduate Teaching Assistant, or part-time rank. However, students tend to have higher passing rates in Calculus I if they took Precalculus with a professor rank faculty. Given that a multitude of extraneous variables and random factors existed, more study will be needed to better understand the impact of instructional model and instructor experience and rank on a university level Precalculus grades
Deciding factors in school choice among parents in the southwest United States
No full textThe purpose of the study was to explore the reasons why parents choose to send their children to schools, other than assigned neighborhood public schools, by identifying common values parents hold about charter schools that lead them to choose charter schools over their assigned public schools. Qualitative data collection was completed within a four-week time frame, with parent participants of students enrolled at a K-12, K-8, or 6-12 choice school within Maricopa County, Arizona. Due to the Covid-19 pandemic, Zoom interviews were conducted with the 16 participants, and a summary of surfaced themes was constructed from the parent participants’ responses to bear record of the overall factors in school choice among parents in the southwest United States.
Research Question 1 addressed reasons parents are sending their children to “choice schools” rather than have them attend their neighborhood public school. Interview answers indicated enrollment decision was due to the influence of trusted individuals or groups of people, i.e., friends, colleagues, fellow church and family members, and even the school’s website. Another reason was because of matriculation from or children aging out of another school.
Research Question 2 addressed the positive attributes of the choice school that influenced parents to enroll their children there. Positive attributes included educational aspects, school schedule, and online websites that included school ratings and test scores. Online websites were highly valued sources of information.
Research Question 2a addressed the profound satisfaction parents had with their decision to enroll their children in the choice school. Due, in large part to school culture, participants were highly satisfied with their child(ren)’s enrollment in the choice schools. Participants of this study plan on continuing enrollment for the 2021-2022 school year.
Regarding consequences parents have faced following enrolling their children in a choice school, participants indicated children are prepared for both higher learning and citizenship. The most identified theme was earning an associate’s degree prior to entering college. Positive feedback discussed attending schools, other than there assigned neighborhood school was a natural choice. Negative feedback came from family and neighbors, centered around participating in the decline of public education. Related to citizenship, participants shared how their children were gaining an understanding of the founding fathers, what the developing country was based on, expectations of them as citizens, and their civic duties
The Effects of Arsenic on Wound Healing in Larval Zebrafish (Danio rerio) and Mice (Mus musculus)
No full textArsenic (As) is a toxic metalloid frequently found in ground and surface water worldwide. While drinking water standards are in place by the Environmental Protection Agency (EPA), many regions of the Southwest United States have reported water sources to be non-compliant with these standards. For example, the Navajo and Hopi Nations and the Verde Valley are three regions in Arizona that have groundwater and surface water with As levels above the EPA limits. Arsenic has numerous potential effects on health outcomes including increased risks for cancers and diabetes. In vitro models of skin cell migration demonstrate that As may inhibit wound healing. In order to determine whether this effect translates into an in vivo system, larval zebrafish (Danio rerio) and mice (Mus Musculus) were used to investigate the effects of 10 μM As on wound healing. We hypothesize that As exposure at environmentally relevant concentrations will delay wound closure and increase wound erythema in vivo, and that these effects may be through both estrogenic and inflammatory pathways. Arsenic-exposed larval zebrafish had their tail fins removed and regeneration was measured over 72 hours. Arsenic had no effect on regeneration. Male and female mice exposed to As had full-thickness wounds created and imaged over a 6-day period. Wound closure was measured, and results showed significantly decreased wound healing in female mice and prolonged erythema. Gene expression analysis showed a 1.5- fold significant upregulation for As3mt and Esr2 gene amplicons, but not for Gper1, Mmp1 or Timp1 in female mice exposed to As, and no effect on any gene amplicons in males. In conclusion, this study shows that As has a sex-specific impact on wound healing in an in vivo model and warrants further research into the molecular mechanism of As interference with wound healing
Biocommunicability and Superstition in Notions of Mental Unwellness in Belize
Get PDFMuch qualitative research has demonstrated the variability and non-universal nature of conceptualizations of mental health and illness in different contexts, including ideas about illness etiology, timing and form of symptom onset, prognosis, and acceptable treatment. While much anthropological literature exists on how understandings of mental health and illness differ between contexts, to my knowledge there is limited qualitative research investigating the Belizean context. My research, described in this thesis, explored ideas about authoritative knowledge on the topic of mental health in television segments; the perceived individuality of psychological struggles and those experiencing them; and societal reactions to those perceived as behaving abnormally. I conducted 15 qualitative interviews and reviewed archival data from a series of television segments featuring mental health professionals to understand how mental unwellness is spoken about in Belize. I draw from Briggs and Hallin’s (2015) theory of biocommunicability to consider professional authority on the topic of mental health; and Goffman’s (1963) theory of stigma to explore participants’ notions of reasons for failure to engage in mental health care. I also consider the factors and individual characteristics understood as contributing to mental unhealth and how they inform participants’ variable interpretations of behavior and flexible recommended interventions. To provide additional context to comments about superstition and my interpretations of the limits placed on care-seeking in relation to mental unwellness, I briefly describe the history of and comments about Obeah, an Afro-Caribbean belief system developed during the transatlantic slave trade that has continued as a “medicine art” in Belize. Ultimately, participants’ judgments about some care as appropriate and some as merely “superstitious” and “stigmatizing” to those with abnormal behaviors simplifies and de-emphasizes macro, micro, and individual factors influencing health related decisions. In a process of attributing continued mental health problems to undesirable mental health management strategies of not seeking psy-resources, and blaming patterns of doing “nothing” on superstitious beliefs, fears of stigma, and Belizean emotion management strategies, participants indirectly implicate culture in the perpetuation of psychological struggles. Future research should explore the factors influencing decisions to not seek psy-resources in Belize
Register Representation and Processing
No full textRegisters are culturally recognized varieties of language that are associated with situations of use (Biber, Egbert, & Keller, 2020). Variation in frequencies of linguistic forms across registers is thought to be functional for the situations they are associated with; that is, certain language features are more common in one register than another because they are suited for the situations associated with the register (Biber & Conrad, 2019, p. 6). It is not possible, however, for situations to influence discourse directly without a mediating layer of cognition; that is, for any aspect of a situation to influence language users’ selection or processing of linguistic forms, that aspect must be modeled mentally (van Dijk, 2005). Therefore, the nature of situational influences on language variation is constrained by cognitive processes. Despite this, little research has investigated registers as psychological (rather than cultural or textual) phenomena. Simultaneously, research on registers from an explicitly psycholinguistic perspective (e.g., Kerz et al., 2020) has focused on the relationships between linguistic items that commonly co-occur within registers, rather than on the relationships between situational cues and their contingent linguistic items.
The current study had two main goals. First, to theorize register variation from an explicitly psycholinguistic perspective. Second, to test implications of the proposed psychological model. I propose that registers are mental categories of texts. Through processes of statistical learning, cross-modal associations are acquired between situational cues and linguistic features. Then, in similar situations, processing of situational cues activates linguistic representations contingent upon those cues. To test this explanation, 62 participants undertook a cross-modal, primed lexical decision task in which they were primed to recognize keywords for one of three registers by short video clips displaying typical situational cues for one of the registers. Findings suggest that viewing a video clip associated with a register facilitated recognition of that register’s keywords, but that this facilitation varied across registers. Registers with many keywords and high mean keyness values were less facilitating than registers with few keywords and low mean keyness values. These findings suggest that the psychological model of register representation and processing proposed here is valid, but underdeveloped
Women’s empowerment in chief traditional authority Mposa, Machinga District of Malawi: an assessment of existing development initiatives to promote women’s economic empowerment
No full textWomen’s economic empowerment still remains a critical issue in Machinga District. Despite the fact that the Malawian government partners with NGOs who are implementing strategies to empower women economically, there is still a gap. Women in Machinga district are experiencing inequalities at the household level which interferes with these development efforts. This thesis is assessing the existing economic strategies to empower women economically by answering the research question “How do we create economically sustainable strategies for subaltern women in rural areas through empowerment programs?” In order to answer this research question, focus group discussions and semi-structured interviews were used to generate data for this project. Through these methods, five themes emerged. These were: (1) gender inequalities need to be addressed at the household level; (2) women should have greater access to loans; (3) capacity building needs to be done at the community level to teach women about checks and balances and to empower men to support their wives and other women in the community to engage in business; (4) there are also gendered attitudes towards women with money which could exclude women from operating their own businesses; and (5) even though women are experiencing gender and economic inequalities, they are able to assert agency and recognize their ability to manage small businesses. This study recommends that women, especially the subaltern, should be encouraged to run small scale businesses and join Village savings and Loans groups. The government should make deliberate efforts in educating rural women about policies so that women may understand the importance of knowing these policies. Lastly there is a need to raise awareness of male involvement. Future efforts should be to involve men to participate in the village savings and loans groups to create a platform for partnership between men and women.
Key words: women’s empowerment, economic strategies, Malawi government, gender inequalities, subaltern women
Portraits of Indigenous students and educators in the time of Coronavirus disease 2019
No full textThis study examined the experiences with remote schooling of Indigenous Kānaka Maoli students and the experiences of Indigenous Kānaka Maoli educators (including non-Indigenous educators of Indigenous students) in Hawaiʻi during COVID-19. The purpose of this study was to understand their experiences so future educational experiences, delivered remotely or in-person, could be made more relevant, meaningful, and with respect to indigeneity. The study was motivated by three research questions: (1) In what ways did schooling change for Indigenous Kānaka Maoli students and Indigenous Kānaka Maoli educators because of the response to the COVID-19 outbreak? (2) What effects, if any, did remote learning have on Hawaiian culture-based education as described by students and teachers? (3) In what ways were the experiences of Indigenous Kānaka Maoli students and teachers the same and/or different in the time of COVID-19 (spring 2020 and fall 2020)? To examine these questions, individual interviews were conducted with study participants and their individual and collective stories were re-told as portraits in a portraiture. The findings from the research showed that Indigenous students and educators faced challenges with remote teaching and learning that were similar to challenges discussed in previous research and some new challenges. The old challenges included access to digital connectivity and physical proximity to one another. The new challenges included the preservation of language, the preservation of Indigenous identity, and maintaining the mission of culture-based education. Implications for school leaders and future research are discussed
The frontier next door: how short-term rentals affect housing in western mountain towns
No full textShort-term rental (STR) platforms like Airbnb increasingly offer entire homes for most of the year. Mounting evidence in large U.S. cities shows that this places them in competition with
long-term housing options. To examine the impact of STRs on smaller, tourism-driven cities, this
research uses Flagstaff (Arizona), Bozeman (Montana), and St. George (Utah) as case studies.
This research utilizes a political ecology theoretical framework to examine these three
cities as part of the “New West” economy, a trend in which municipalities in the 11 contiguous
western states protect natural amenities to grow their economies. Through extensive interviews
with officials in each city, this research shows that STRs have seen limited restrictions despite
widespread acknowledgement that they have exerted significant pressure on local housing
markets.
Although digital STR platforms are relatively new, this research argues that STRs should
be understood as part of a long-standing frontier imaginary whereby blank spaces are created for
outsiders willing and able to pay more, in this case tourists and second homeowners. This
research traces five distinct frontiers throughout U.S. history which opened previously settled
places to outside wealth, identifying STRs as part of the current “financialization of home.”
Building on proposals from interviewees and strategies of other cities, this research
closes by arguing for a change in attitudes and policies which ensure locals are benefiting from,
not competing with, outside visitation
Perceived impact of an artificial intelligent chatbot by first-generation Hispanic students enrolling at a public university
No full textThe Hispanic student population is growing at a fast pace in the United States. This population is more likely to be first-generation students than their peers and thus, require additional support. Advances in technology make it possible to leverage artificial intelligence and machine learning to support students at scale presenting an opportunity to support first-generation Hispanic students. This study analyzed the perceived helpfulness of an artificially intelligent chatbot aiding in the enrollment process at a four-year public university in the southwest United States. The study found heterogeneity among ethnicity as it relates to the perceived impact on the admissions experience and contact frequency. However, the study found evidence of a preference by first-generation students in their perception of the chatbot’s positive impact on their admissions experience and contact frequency. This perception is likely the result of lower social capital, making the reminders and nudges from the chatbot be perceived more positively. This study also explored differences in Hispanic students when considering gender and found no correlation. Last, the study found no relationship between perception, ethnicity, and likelihood to enroll, an indication that the chatbot may aid in task completion but more complex support may be needed to guide the student towards enrollment