IN THE NAME OF CIVIL SOCIETY : CONTESTING FREE ELECTIONS IN THE POST-COLONIAL PHILIPPINES (ELECTIONS)

HEDMAN, EVA-LOTTA ELISABET CORNELL UNIVERSITY 1998 해외박사

The Princeton IQU Experiment and constraints on the polarization of the cosmic microwave background at 90 GHz

Hedman, Matthew McKay Princeton University 2002 해외박사(DDOD)

The polarization anisotropies in the Cosmic Microwave Background provide important information about the structure and dynamics of the early universe. This cosmological polarization has thus far eluded detection, which is not surprising because it should be an extremely small signal (an order of magnitude smaller than the temperature anisotropies, or about 5 μK <italic>rms</italic> variations in 3K thermal radiation). The Princeton IQU Experiment, or PIQUE, is an effort to measure this tiny polarized signal using two correlation polarimeters operating at W-band (84–100 GHz) and Q-band (35–46 GHz). This work describes the construction, characterization, observations and preliminary results from the W-band system, which observed the sky around the north celestial pole over two successive winters (2000 and 2001), and acquired 500 hours of useful data. These data yield one of the tightest constraints on the cosmological polarization to date.

Regulation of Lysosomal Sorting by Phosphatidylinositol 4-Phosphate, 5-Kinase Type I Gamma i5 and Sorting Nexin 5

Hedman, Andrew Charles The University of Wisconsin - Madison 2012 해외박사(DDOD)

Phosphoinositide signaling is known to regulate a wide variety of cellular processes, including intracellular trafficking pathways. Phosphoinositide synthesis at specific cellular compartments is regulated by the specific targeting of phosphoinositide modifying enzymes. Phosphatidylinositol 4,5 bisphosphate (PI4,5P2) is primarily synthesized by the type I phosphatidylinositol 4 phosphate 5 kinase (PIPKI) family of enzymes. There are several PIPKI genes and there exist several splice variants for each. The recently discovered PIPKIgammai5 splice variant is localized to intracellular compartments, but its functions are unknown. Initial studies have identified roles for PIPKIgammai5 in promoting the lysosomal sorting of E-cadherin and Epidermal Growth Factor Receptor (EGFR). Therefore, my research focused on how PIPKIgammai5 regulates this pathway. A specific direct interaction was identified between PIPKIgammai5 and Sorting Nexin 5 (SNX5), a PI4,5P2 binding protein that regulates intracellular trafficking. In this pathway, PIPKIgammai5 was found to promote E-cadherin lysosomal degradation, which requires Rab7 function. SNX5 was found to enhance E-cadherin protein levels, but was not required for PIPKIgammai5 function in this pathway. Additionally, PIPKI7i5 and SNX5 were found to be required for EGFR degradation. Furthermore, it was assessed how PI4,5P2 may regulate SNX5 function. Point mutations were identified in the SNX5 PX domain that reduce binding to PI4,5P2 or PIPKIgammai5. However, these mutations did not result in a loss of function for SNX5 function in this pathway. These PIPKIgammai5 studies provide evidence for a novel role for PI4,5P2 in regulating lysosomal sorting. This pathway may be relevant to normal cellular function and potentially, changes in PIPKIgammai5 signaling may alter EGFR and E-cadherin function, resulting in pathological consequences.

Analysis of Polar Organic Compounds in Environmental Samples by Mass Spectrometric Techniques

Hedman, Curtis James The University of Wisconsin - Madison 2012 해외박사(DDOD)

The utility of mass spectrometric (MS) techniques is highlighted in three studies that analyze a wide variety of organic compounds in complex environmental matrices. First, a battery of MS techniques is used to identify and quantify over 180 compounds emitted from crumb rubber amended synthetic turf. Quality control data demonstrate the efficacy of these MS techniques for the purpose intended. Second, high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) is used to measure very low levels of estrogenic and androgenic compounds in samples from Confined Animal Farming Operations (CAFOs). Fractionation HPLC is used to isolate hormonal bioactivity and to determine whether the toxicological potency, as measured by bioassay, can be accounted for by the types and concentrations of hormones identified. Third, HPLC-MS/MS is used with a variety of scan modes along with isotope labeling to propose abiotic breakdown pathways for the sulfonamide antimicrobial compound sulfamethazine. In the first study, most compounds were analyzed at the low ng/sample level with good accuracy and precision. However, compounds in laboratory air presented interference problems for some analytes, such as carbon disulfide, 2-methyl butane, acetone, benzene, methylene chloride, methanol, and pentane. HPLC-MS/MS methods replaced established gas chromatographic methods to measure seven N-Nitrosamines, benzothiazole, 2-mercaptobenzothiazole, 4-tert-octylphenol, butylated hydroxytoluene, and butylated hydroxyanisole. In the CAFO study, much of the hormonal bioactivity in the samples could be accounted for by the HPLC-MS/MS target compounds detected (17-beta-estradiol, 4-androstene-3,17-dione, progesterone, 17,20-dihydroxyprogesterone, nandrolone, and zearalenone). Gas Chromatography - Mass Spectrometry (GC/MS) analysis of bioactive fractions identified compounds potentially responsible for unaccountable endocrine disrupting bioactivity (a triazine herbicide and a phthalate). Finally, HPLC-MS/MS analysis showed that sulfamethazine is transformed by birnessite under oxic conditions to an azo-dimer self-coupling product and SO2 extrusion products. These studies demonstrate how modern MS techniques are effective for analyzing a wide array of organic compounds in difficult environmental matrices.

Health and cultural interaction in the Illinois Country: A bioarchaeological analysis of three historic Native American populations

Hedman, Kristin Marie University of Illinois at Urbana-Champaign 2007 해외박사(DDOD)

Great strides have been made in documenting the complexities of interaction between indigenous people and the expanding European economic and political interests in the Illinois Country. This bioarchaeological study focuses on the degree to which skeletal evidence for disease, nutritional status, and trauma correlates with historical evidence of health and behavior. It is hypothesized that differences in the nature and intensity of interaction between Native Americans and Europeans resulted in measurable differences in skeletal markers of health and behavior of Native American populations. Archaeological and skeletal data are used to examine the biological impact of European contact and colonization on three Native American tribes---the Kaskaskia in northern Illinois (A. D. 1640-1700), the Michigamea in southwestern Illinois (A. D. 1753-1765), and the Sauk in northwestern Illinois (A. D. 1780-1820). These sites and populations represent three distinct periods, each characterized by unique conditions and events that impacted the lives and lifestyles of Native American inhabitants. Analysis of these data revealed that patterns of population health, trauma, and activity-related morphology are consistent with ethnohistoric descriptions and archaeological evidence of historical events and conditions. Unanticipated differences in health and lifestyle were identified between sites, and between males and females within sites. While many of these are attributable to temporally-related differences in access to European resources, exposure to disease, and proximity to European settlements, some differences are better explained by the lifestyle choices of the Native American populations in question. When sexes are compared between sites, males tend to show less variation (e.g., in caries rates, LEH frequency, and the nature of pathologies and trauma) than females, indicating that while the lifestyle of males was fairly similar, the lifestyle of women varied between populations in response to their changing roles in their individual communities. This study emphasizes the important contributions that bioarchaeological research provides to a more complete understanding of the historical consequences of cultural contact between Europeans and Native American communities.

Experimental observation and modeling of solid composite propellants

Hedman, Trevor Purdue University 2012 해외박사(DDOD)

Since the 1960's, composite propellants have been widely used in rocketry applications because of their excellent performance and low cost to implement. Due to their pervasive use, there has been a strong desire for a method to predict the performance of a propellant <italic>a priori.</italic> The ability to predict performance would accelerate development of solid propellants, minimizing the required amount of costly empirical data. Early flame structure models for composite propellants such as the granular diffusion flame (GDF) and the Beckstead, Derr, Price (BDP) models, were introduced in the 1960's and 1970's respectively. These well-known models involved the development of heuristic relations to predict the burning rate of a composite propellant. Increased computing power in recent years has allowed for more advanced modeling of solid propellants. Models exist today that incorporate detailed chemistry in the gas phase with a simplified geometry as well as a 3-D surface structure using simple chemistry. However, these models lack validation due to the dearth of detailed experimental data on composite propellants. This is due, in part, to the challenging nature of the combustion environment. The flame is particulate heavy, transient, and highly spatially variant. Additionally, composite propellant surface morphology is complex, made up of complex mixtures of oxidizers and fuels. This document summarizes an effort to provide detailed experimental data for todays advanced models that is currently lacking in the literature. Experiments are designed and carried out to quantify the flame structure and surface behavior of various composite propellants. High speed PLIF and high resolution surface imaging are employed at various pressures in order to characterize flame structure and surface behavior. In addition, an attempt is made to begin to improve existing composite propellant models. This is performed by first combining a micro-scale detailed chemistry model and a meso-scale model that includes surface topography. This model is compared with the experimental results and areas for improvement are identified. It is hoped that increased knowledge of the flame structure and surface structure of composite propellants will translate into better <italic>a priori</italic> predictions of performance eventually.

Flexible Transmission in the Smart Grid

Hedman, Kory Walter University of California, Berkeley 2010 해외박사(DDOD)

There is currently a national push to create a smarter electric grid; introducing new technologies that will create a more controllable and flexible grid is part of the smart grid concept and integral to its success. The full control of transmission assets are not currently built into electric energy dispatch optimization models. Optimal transmission switching is a straightforward way to leverage grid controllability: to make better use of the existing system and meet growing demand with existing infrastructure. Previous research has shown that transmission switching as a corrective mechanism can help relieve line overloading, voltage violations, etc. However, there has been limited focus on the use of transmission switching as a means to improve the economic efficiency of the network by incorporating the control of transmission assets into the overall economic dispatch problem. This research discusses the ways that the modeling of flexible transmission assets can benefit the multi-trillion dollar electric industry. It presents and analyzes novel formulations by which the operator can incorporate this flexibility into the economic dispatch formulation. This research focuses on modeling transmission assets so that they can be temporarily taken out of service, i.e., by opening breakers, or kept in service, i.e., by keeping the breakers closed. By incorporating this control into the network optimization problem, this provides the ability for the operator to consider the state of a transmission line as a decision variable instead of treating it as a static asset, which is the current practice today. The possible benefits demonstrated from this research indicate that the benefits to society are substantial. On the contrary, the benefits to individual market participants are uncertain; some will benefit and other will not. Consequently, this research also analyzes the impacts that optimal transmission switching may have on market participants as well as the policy implications. Methods to improve the solution time of this difficult problem are discussed as well.

Don't Count Your Eggs Before They Hatch: A "One Health" Investigation of Antimicrobial Resistance at the Intersection of Small-scale Agricultural Development and Global Health in Northwestern Ecuador

Hedman, Hayden D ProQuest Dissertations & Theses University of Mich 2019 해외박사(DDOD)

Small-scale poultry production systems have been essential to human livelihoods among rural agricultural communities for millennia, improving diet, finances, and food security of impoverished rural populations. Poultry farming is the fastest growing agricultural sub-sector, especially among low- and middle-income countries (LMICs). Small-scale chicken farming remains a rapidly growing micro industry because of the low initial investment compared to other food animals. Although the majority of households globally continue to practice backyard poultry farming, primarily encompassing indigenous chickens or sometimes crossbred varieties, more recently, there has been a shift from subsidence farming of local free-range backyard chickens to industrial food production breeds of poultry reared in concentrated animal feeding operations (CAFOS). Often international non-governmental organizations promote commercial small-scale chicken farming as a means to promote improved food security, economic development, and gender equity. Such intervention strategy has become more common since the United Nation’s Sustainability Goals to end hunger, achieve food security and improved nutrition and promote sustainable agriculture by 2030. Despite the economic benefits of industrially animal production, such introductions can present serious risks to animal and human health. Specifically, poultry reared in CAFO environments receive high amounts of antimicrobials for growth promotion and prophylaxis, leading to increased likelihood of zoonoticspillover events of antimicrobial-resistant commensal organisms and pathogens into surrounding human populations. Globally, industrialization of agriculture is expected to exponentially increase along with the concentration of antimicrobials used in animal agriculture. Consequently, this dissertation applies a “One Health” cross disciplinary approach towards studying the confluence of small-scale agricultural development and global health within rural northwestern Ecuador. In chapter two, I present a cross-sectional study examining the impacts of a synchronous introduction of broiler farming within one community. I then enrolled 10 households to monitor the change in backyard chicken E. coli resistance levels after the introduction of broiler chickens. I found phenotypic and genotypic evidence supporting the spillover of cefotaxime resistance from broiler chickens to backyard chickens and potentially to children. In chapter three, I present a longitudinal field study to better understand the spatial relationship of antimicrobial resistance in communities that conduct small-scale farming in northwestern Ecuador. I analyzed phenotypic resistance of E. coli sampled from humans and backyard chicken to 12 antibiotics in relation to the distance to the nearest small-scale farming operation. I did not find any statistical significance when testing the relationship between the distance of a household to small-scale farming and backyard chicken or human susceptibility to antibiotics associated with that household. I also monitored the movement of backyard chickens. The null results of antimicrobial resistance spatial analysis can be supported by the observation of the extensive home range of free-ranging backyard chickens. Chapter 4 uses the same dataset from chapter 3 to examine antimicrobial resistance carriage. Between sample period 1 and 2, I observed significant increases in 6 of the 12 antibiotics in humans and 4 of the 12 antibiotics in backyard chickens. These findings suggest that the recent rebound in farming activity after a regional collapse in farming, and the observed increase of AMR in the one-day old broilers was likely the cause of the observed increase in AMR in backyard chickens and children. This dissertation provides evidence that small-scale poultry farming activity causes the emergence, spread, and persistence of antimicrobial resistance in low- and middle-income countries.