Doctor of Philosophy

dissertationSperm competition is a pervasive mode of sexual selection across the phyla that have crucial implications in microevolutionary and macroevolutionary processes. Furthermore, females can bias the selection of sperm from one male over another in a process known as cryptic female choice. While sperm competition has been the subject of intense experimental research, very little is known about the molecular pathways and cellular mechanisms that regulate these processes. Insight into the molecular pathways regulating sperm competition and cryptic female choice are likely to have a high impact in the field of evolutionary biology since so little is currently known. The nematode C. elegans offers many advantages for the study of sperm competition. Male sperm exhibit a robust competitive advantage over hermaphrodite self sperm, resulting in the almost complete preferential use of male sperm. We have identified a gene, comp-1, that regulates several sperm behaviors leading to reduced male precedence when competing with both self sperm and other male sperm. Critically, mutant males and hermaphrodites have normal fertility, suggesting that mutants produce and transfer as many functional sperm competent for motility, sensation of guidance cues, and fertilization as do wild type. We have shown that the comp-1 sperm behavioral defects are specific to competitive contexts as comp-1 sperm are functionally normal when wild type iv sperm are absent. Surprisingly, wild type sperm appears to inhibit comp-1 sperm by altering the chemical environment of the hermaphrodite, most likely to involve prostaglandin signaling. Intercellular communication between the reproductive tract and sperm is fundamental for sperm migration, and prostaglandins have been previously identified as important for this process. However, this is the first time that prostaglandins have been implicated as necessary for sperm competition. Furthermore, prostaglandins are a novel mechanism of cryptic female choice and add to the field where very little is known about how females influence sperm competition. Results from our studies of comp-1 will provide insight into the molecular pathways necessary for sperm competition and cryptic female choice, which will ultimately broaden our knowledge of the mechanisms of evolutionary change

Vegetation Cover Analysis of Hazardous Waste Sites in Utah and Arizona Using Hyperspectral Remote Sensing

This study investigated the usability of hyperspectral remote sensing for characterizing vegetation at hazardous waste sites. The specific objectives of this study were to: (1) estimate leaf-area-index (LAI) of the vegetation using three different methods (i.e., vegetation indices, red-edge positioning (REP), and machine learning regression trees), and (2) map the vegetation cover using machine learning decision trees based on either the scaled reflectance data or mixture tuned matched filtering (MTMF)-derived metrics and vegetation indices. HyMap airborne data (126 bands at 2.3 x 2.3 m spatial resolution), collected over the U. S. Department of Energy uranium processing sites near Monticello, Utah and Monument Valley, Arizona, were used. Grass and shrub species were mixed on an engineered disposal cell cover at the Monticello site while shrub species were dominant in the phytoremediation plantings at the Monument Valley site. Regression trees resulted in the best calibration performance of LAI estimation (R-2 > 0.80. The use of REPs failed to accurately predict LAI (R-2 < 0.2). The use of the MTMF-derived metrics (matched filter scores and infeasibility) and a range of vegetation indices in decision trees improved the vegetation mapping when compared to the decision tree classification using just the scaled reflectance. Results suggest that hyperspectral imagery are useful for characterizing biophysical characteristics (LAI) and vegetation cover on capped hazardous waste sites. However, it is believed that the vegetation mapping would benefit from the use of higher spatial resolution hyperspectral data due to the small size of many of the vegetation patches (<1 m) found on the sites.open111

OpenET : filling a critical data gap in water management for the western United States.

The lack of consistent, accurate information on evapotranspiration (ET) and consumptive use of water by irrigated agriculture is one of the most important data gaps for water managers in the western United States (U.S.) and other arid agricultural regions globally. The ability to easily access information on ET is central to improving water budgets across the West, advancing the use of data-driven irrigation management strategies, and expanding incentive-driven conservation programs. Recent advances in remote sensing of ET have led to the development of multiple approaches for field-scale ET mapping that have been used for local and regional water resource management applications by U.S. state and federal agencies. The OpenET project is a community-driven effort that is building upon these advances to develop an operational system for generating and distributing ET data at a field scale using an ensemble of six well-established satellite-based approaches for mapping ET. Key objectives of OpenET include: Increasing access to remotely sensed ET data through a web-based data explorer and data services; supporting the use of ET data for a range of water resource management applications; and development of use cases and training resources for agricultural producers and water resource managers. Here we describe the OpenET framework, including the models used in the ensemble, the satellite, meteorological, and ancillary data inputs to the system, and the OpenET data visualization and access tools. We also summarize an extensive intercomparison and accuracy assessment conducted using ground measurements of ET from 139 flux tower sites instrumented with open path eddy covariance systems. Results calculated for 24 cropland sites from Phase I of the intercomparison and accuracy assessment demonstrate strong agreement between the satellite-driven ET models and the flux tower ET data. For the six models that have been evaluated to date (ALEXI/DisALEXI, eeMETRIC, geeSEBAL, PT-JPL, SIMS, and SSEBop) and the ensemble mean, the weighted average mean absolute error (MAE) values across all sites range from 13.6 to 21.6 mm/month at a monthly timestep, and 0.74 to 1.07 mm/day at a daily timestep. At seasonal time scales, for all but one of the models the weighted mean total ET is within ±8% of both the ensemble mean and the weighted mean total ET calculated from the flux tower data. Overall, the ensemble mean performs as well as any individual model across nearly all accuracy statistics for croplands, though some individual models may perform better for specific sites and regions. We conclude with three brief use cases to illustrate current applications and benefits of increased access to ET data, and discuss key lessons learned from the development of OpenET

Repositioning of the global epicentre of non-optimal cholesterol

High blood cholesterol is typically considered a feature of wealthy western countries(1,2). However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world(3) and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health(4,5). However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol-which is a marker of cardiovascular riskchanged from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million-4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.Peer reviewe

The Identification and Reporting of Physical Abuse by Physicians: A Review and Implications for Research

Identification and reporting of possible cases of child physical abuse are critical precursors to intervention with maltreating families. Professionals from a variety of disciplines are mandated to report suspected cases of child maltreatment. Unfortunately, not all physically abused children are identified or reported. This paper reviews the literature that has examined factors that may influence the identification and reporting of physical abuse by physicians. The literature review is preceded by an overview of the multistep, multibehavior process of identification and reporting. The factors that may influence identification and reporting are discussed according to their association with the case, physician, or setting. Future directions for research in the area of identification and reporting are suggested throughout the paper

Reminiscences of early days in Manti

Typescript (3 pages) of memoir (dated July 18, 1945) of Jody Hansen (age 87), assisted by his brother Pete Hansen (89) on early days in Manti, Sanpete County, Uta

Child Physical Abuse

Widespread attention to the problem of child physical abuse has increased dramatically in recent decades. Extensive research evidence has described child physical abuse as a complex, multidimensional phenomenon that is best assessed by procedures using multiple modalities (e.g., interview, self-report, direct observation) that address multiple content areas. Comprehensive assessment is essential for identifying risk and occurrence of abuse, guiding the focus or direction of treatment, as well as monitoring treatment efficacy and outcome, all of which may be disseminated to interested parties as appropriate (e.g., CPS, judicial system, school, other treatment providers). Increasingly specific and relevant procedures have become available for many of the commonly targeted areas of assessment. In general, recent advances have been especially significant in the development of self-report and analogue assessments to measure parental responses in a variety of contexts (Hansen & MacMillan, 1990; Lutzker, 1998; Lutzker et al., 1998; Wolfe & McEachran, 1997). The complex, multiproblem nature of maltreating families and child physical abuse presents many assessment difficulties for both clinicians and researchers. The assessment of physically abusive families is complicated by issues such as mandatory reporting and other legal considerations, the potential unwillingness of parents to cooperate, and contextual factors and stressors that interfere with a family\u27s ability to participate (e.g., social isolation, relationship problems, financial difficulties). Although there are many suggested strategies, further research on the. most effective and appropriate methods of addressing these issues and conducting comprehensive and accurate assessments is needed