Economics of the aircraft industry : by Gene Roger Simonson

Simonson, Gene Roger University Microfilms International 1977 국내박사

Structural and Magnetic Investigation of Organic Building Blocks for Molecule-Based Magnetic Materials

Simonson, Andrew Nels The University of Utah ProQuest Dissertations & Th 2020 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

A series of 1st-row transition metal complexes with either diazafluorene or tetraoxalate ligands were synthesized and studied.The reaction of Fe(BF4)2, TPyA [tris(2-pyridylmethyl)amine], and sodium nitroanilate (Na21NO2) produced the 7-coordinate oxygen-bridged dimer [FeIII(TPyA)1NO2]2O. The assignment of a binuclear heptacoordinate high-spin FeIII state is supported by the isomer shift and quadrupole splitting of the 57Fe Mossbauer spectra. At temperatures above 35 K, the spectra exhibit a single quadrupole doublet indicating equivalency of the two iron sites of the dimer, while below 35 K, the single quadrupole doublet splits into two doublets arising from structural non-equivalency between the two iron sites at low temperature. A homonuclear Sa = Sb = 5/2 dinuclear spin model (H = –2JSa•Sb) was fitted to the magnetic properties of [FeIII(TPyA)1NO2]2O to reveal strong antiferromagnetic intradimer coupling (J/kB = –146 K = –101 cm–1) and weak interdimer antiferromagnetic coupling (θ = –5 K) with g = 2.00. The reaction of Mn(O2CMe)2, TPyA, and chlorianilic acid (H21Cl) produced MnII(TPyA)1Cl, a 1-D zigzag chain of 7-coordinate MnII sites bridged by 1Cl2– anions. The magnetic properties of MnII(TPyA)1Cl can be fit to a homonuclear S = 5/2 1-D Fischer chain model with weak intrachain antiferromagnetic coupling (J/kB = –0.33 K = –0.23 cm–1) and weak interchain antiferromagnetic coupling (zJ’/kB = –0.05 K = –0.03 cm–1) with g = 2.06.The reaction of [MII(NCMe)6][SbF6]2 (M = Mn, Fe, or Co) with TPyA and 9’-(4,5-dimethyl-1,3-dithiol-2-ylidene)-4’,5’-diazafluorene (L) produced [(TPyA)MII(L)][SbF6]2 (M = Mn, Fe, or Co). Single-crystal x-ray diffraction studies indicate all three complexes are isostructural. The UV-vis spectra in dichloromethane and the solid-state IR spectra are consistent with L coordinated to MII in each respective complex. UV-vis studies in acetone or acetonitrile result in the formation of the free ligand and solvated MII, indicating that L is readily labile in the presence of coordinating solvents. The magnetic properties of the three [(TPyA)MII(L)][SbF6]2 complexes were fit to the Curie-Weiss Law; analysis reveals weak ferromagnetic coupling for the Mn and Co complexes while the Fe complex exhibits weak antiferromagnetic coupling.

Limiting Financial Risk from Catastrophic Events in Project Management

Simonson, Peter Douglas ProQuest Dissertations & Theses North Dakota State 2020 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

This dissertation develops a mixed integer linear program to establish the upper and lower bounds of the Alphorn of Uncertainty. For a project manager, planning for uncertainty is a staple of their jobs and education. But the uncertainty associated with a catastrophic event presents difficulties not easily controlled with traditional methods of risk management. This dissertation brings and modifies the concept of a project schedule as a bounded “Alphorn of Uncertainty” to the problem of how to reduce the risk of a catastrophic event wreaking havoc on a project and, by extension, the company participating in that project. The dissertation presents new mathematical models underpinning the methods proposed to reduce risk as well as simulations to demonstrate the accuracy of those models. The dissertation further assesses the complexity of the models and thus their practical application. Finally, the dissertation presents strategies to reduce the risk to a project of a catastrophic event using the upper bound of the Alphorn as the measure of risk.

Mathematical Theory of Opinion Dynamics with Applications

Simonson, Daniel Vincent ProQuest Dissertations & Theses University of Cali 2022 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Opinion dynamics can be modeled by using agent-based simulations, where agents in a population are characterized by binary opinions on a number of different issues. They engage in pairwise interactions, whereby if the agreement level is high, the interlocutor is recognized as an “ally” and the individual will flip one of their opinions to coincide with the interlocutor; if the agreement is low, they will switch away from the interlocutor. While it is usually assumed that all issues in the opinion vector are equally important, in chapter 2 we investigate how breaking this symmetry influences the dynamics. We find that the model outcomes can be predicted by a single Agreement-Disagreement Score (ADS) in [−1, 1]. ADS characterizes how likely individuals in the population are to regard an interlocutor as an ally; low-ADS (very “cautious”) populations tend to converge to a two-faction system with exponentially high convergence times, while high-ADS (very “trusting”) populations tend to converge to a single-faction system relatively fast. In heterogeneous populations characterized by individual issue weighting, individuals that are more “trusting” are more likely to join the majority group compared to those that are more “cautious”. In the presence of an influencer, for ADS both near −1 and 1, a single faction tends to emerge, but in the former case it coincides with the influencer’s opinions, while in the latter case it is the opposite. Time to fixation is also affected by the presence of an influencer, especially for negative-ADS populations, where it no longer experiences such a large increase near −1. One can say that an influencer unifies the population to align with the source of influence if ADS> 0 and to disagree with it if ADS< 0, and consensus is reached relatively fast for both extremely “trusting” and extremely “cautious” populations. In chapter 3 we introduce a system of ordinary differential equations (ODEs) which govern the behavior of the discrete stochastic model studied in chapter 2. We find a neutrally stable solution to the system which, when it is the only stable solution, provides a mathematical description for the extremely long times to fixation observed in the stochastic model under certain conditions. Chapter 4 turns to a real world example as we analyze the so-called re-tweet network of tweets concerning the HPV vaccine on the social network Twitter. Community detection algorithms provide a way to split the nodes of a network into two or more communities. Using a label propagation method, survey data, and a construction of cultural consensus for survey response data we find a natural division in this network into two distinct communities, one of which is pro-HPV vaccine and the other is anti-HPV vaccine.

Chromosomal and carcinogenic effects of sequential HZE and low-LET irradiations

Simonson, Dustin Mark The Johns Hopkins University 2002 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

All persons are exposed to a natural background of ionizing radiations with different spatial patterns of energy deposition resulting in differential biologic response. Astronauts, aircrew and radioactive contamination clean-up personnel are exposed to particularly complex radiation spectra. The current method for calculating radiation-induced exposure limits in mixed radiation environments is based on the linear summation of non-threshold risks, a methodology grounded in the premise that each component of the radiation field acts independently of the presence of other components. The assumption of effect independence of in-vitro exposed samples was tested by evaluating the frequency of chromosome aberrations induced by sequential irradiation of immortalized human mammary epithelial cells with 1 GeV/nucleon <super> 56</super>Fe ions and <super>137</super>Cs gamma-rays. Experimental response was found to be significantly less than calculated on the basis of effect independence, but only when <super>56</super>Fe ions preceded the photon exposure. That there was order dependence is interpreted as evidence that response may not simply be a result of interactions between similar sublesions but rather may involve qualitatively different time-ordered parameters. The presence of this sub-additive response is phenomenologically similar to adaptive response, which had not been previously reported as a consequence to high-energy heavy ion irradiation. Calculations based on effect independence predict a significantly greater average number and lifetime cumulative incidence of breast cancers in female Sprague-Dawley rats irradiated with both <super>56</super>Fe ions and 250 MeV protons than was experimentally observed. This finding supports the hypothesis that the presence of non-additive response is not exclusively an <italic> in vitro</italic> phenomenon. Results from an evaluation of mammary epithelial cell response induced in a rat cancer model are marginally consistent with the use of <italic>in vivo</italic> induced chromosome aberrations as a biomarker of breast cancer risk. There is also an apparent association between the two endpoints relating to dependence on radiation quality. In conclusion, these data demonstrate that sequential exposures to both HZE and low-LET radiation may result in chromosomal and carcinogenic response that is inconsistent with effect independence. These results provide evidence that the linear summation of health risks from mixed HZE and low-LET radiation fields may not accurately reflect true risk.

The mechanism of action of the HPV16 E6 protein in cancer: A role for PDZ domain proteins

Simonson, Sara Jane Speros The University of Wisconsin - Madison 2006 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Human papillomaviruses (HPVs) are DNA viruses that infect squamous epithelia. A subset of HPVs, called high risk HPVs, cause cervical cancer and are associated with other less common anogenital cancers and a subset of head and neck cancers. In cervical cancers the viral genome is often found integrated into the host genome and the HPV genes E6 and E7 are selectively upregulated. E6 is a multifunctional protein that associates with a variety of cellular factors that differentially contribute to E6's phenotypes. My thesis studies were focused on understanding the role of E6's interactions with cellular PDZ domain proteins in E6's induction of phenotypes. To determine what phenotypes induced by E6 in vivo were dependent upon E6's interactions with PDZ domain proteins I compared phenotypes between K14E6WT mice and mice expressing a mutant E6 protein that is unable to associate with PDZ domain proteins ( K14E6Delta146-151). From these studies I determined that E6's interactions with PDZ domain proteins are required for E6's ability to disrupt differentiation and cause spontaneous tumors in the skin of mice. Further, I found that E6's interactions with PDZ domain proteins are required for E6's promotion activity, but dispensable for E6's progression activity in a multistage skin carcinogenesis model. To address what PDZ domain proteins or cell signaling pathways are mediating E6's phenotypes in vivo, I analyzed mice carrying mutant alleles of E6's PDZ domain partners Magi1 and Dlg and a mouse harboring a conditional knockout allele of the tumor suppressor, PTEN. These studies allowed me to determine the neither Magi1 nor Dlg are the all-important PDZ domain protein required for E6's induction of phenotypes. Additional studies with the conditional Dlg knockout mice allowed me to study the role of Dlg in development, where I found that Dlg is critical for many aspects of mammalian development. Additionally, my analysis of conditional PTEN knockout mice allowed me to determine that the inactivation of PTEN is insufficient to recapitulate E6's phenotypes in the suprabasal compartment. Surprisingly, however, deletion of PTEN in the basal compartment revealed a novel activity of E6: the induction of basal DNA synthesis.

The roles of talin1 and calpain in T cell adhesion and migration

Simonson, William T. N The University of Wisconsin - Madison 2007 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The development of an adaptive immune response is dependent on the recognition by T cells of antigen displayed by antigen presenting cells (APCs). In their unactivated state, T cells migrate rapidly through lymphoid tissues in search of cognate antigen. When a T cell contacts an APC, the T cell stops migrating and adheres to the APC, forming a stable contact termed the immunological synapse. This transition from a highly migratory to a highly adherent phenotype depends on the rapid accumulation at the T cell-APC contact site of structural and adhesive molecules, particularly actin and the integrin LFA-1. In this work, I describe a role for the cytoskeletal protein talin1 in immunological synapse formation. Adhesion of talin1-deficient T cells to antigen-presenting cells is impaired, as is LFA-1-dependent adhesion to ICAM-1-coated surfaces. Talin1-deficient T cells are defective in both LFA-1 affinity regulation and clustering, and the rescue of LFA-1 affinity is not sufficient to permit the normal function of talin1-deficient T cells. Finally, the actin-binding region in the talin1 rod domain, but not the integrin-binding region in the talin1 head domain, is required for talin1 targeting to the immunological synapse. Together, my results indicate that talin1 is recruited to the immunological synapse by the actin cytoskeleton, where it activates LFA-1 and recruits it to the site of TCR ligation, thereby stabilizing the nascent immunological synapse. I also demonstrate that the intracellular protease calpain is required for the arrest of T cell migration following antigen recognition. While T cells deficient in calpain 2 or its regulatory partner calpain 4 migrate normally on an ICAM-1-coated surface, they are unable to stop when stimulated by CD3 crosslinking. However, in contrast to the results of previous studies, calpain is not required for LFA-1-dependent adhesion following antigen recognition, indicating that calpain mediates T cell arrest by some other mechanism. These results suggest that calpain is an important regulator of T cell activation, and is a promising target for the therapeutic manipulation of immune function.

Music, dance, and female creativity in early twentieth-century American performance

Simonson, Mary Elizabeth University of Virginia 2007 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

A plethora of female performers emerged within American art and entertainment in the first decades of the twentieth century. Creating and staging pieces that combined music and dance in venues ranging from opera houses and concert halls to vaudeville theaters and film, these women were ubiquitous, popular, and a significant part of turn-of-the-century American musical life and culture. Actively adapting and amending (often European) musical texts, they created and performed new acts and roles, displaying onstage shifting body politics and practices, new forms of art and entertainment, and the strong, symbiotic relationship between music and movement. In this dissertation, I explore a series of four of these performances: the dancing Salomes that swept the United States during the first two decades of the twentieth century, Isadora Duncan's written and danced relationship with Richard Wagner's opera scores and theories, ballerina Anna Pavlova's film version of D.F.E. Auber's 1828 opera La Muette de Portici, and choreographer Michel Fokine's Les Sylphides, as staged by Serge Diaghilev's Ballets Russes during their 1916 American tour. These performances, I argue, challenge and enhance musicological narratives and methodologies in several ways. First, they offer unique insights into early twentieth-century American musical tastes, practices, and identities, as well as notions of American musical identity. Second, they reveal the fluid relationships between composer, performer, and audience, encouraging expanded definitions of creativity and authorship. Finally, and most importantly, they foreground the close historical connections between music and dance traditions, the ways in which music and movement inflect one another onstage, and the embodied nature of performance. In recent years, both "performance" and "the body" have been increasingly invoked in musicological scholarship as a means of complementing and complicating familiar readings of musical works. Both have also increasingly taken on an amorphous, slippery quality. In this dissertation, I am interested in demystifying these terms by returning to the sights and sounds of each performance, the physical and musical gestures that each entailed, the reactions of audience members and critics, and the ways in which each of these performances reflected and constructed the cultural moment in which it was conceived and presented.

Effectiveness of Dialectical Behavior Therapy Skills Training for Individuals with Psychosis

Simonson, Alix Palo Alto University ProQuest Dissertations & Thes 2022 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Individuals with psychosis struggle with emotion regulation in ways that exacerbate their symptoms, contribute to comorbid conditions, and detract from quality of life. However, there is little literature on treatment options targeting emotion regulation for this population. Dialectical behavior therapy (DBT) is a widely used and highly effective treatment for problems of emotion regulation, implemented across a wide array of psychiatric disorders and transdiagnostic populations. However, individuals with psychosis have often been excluded from RCT’s of DBT, and little research has been conducted directly on DBT for psychosis. Driven by the need to provide useful tools to patients struggling with psychosis and emotion dysregulation, many clinical settings are already offering DBT-based interventions to this population. Research is needed to bridge the gap between science and practice. This study examined the effectiveness of a DBT skills group for individuals with symptoms of psychosis. Among a sample of adult participants (n = 118) enrolled in a naturalistic study of DBT at an outpatient clinic, a subsample of participants (n = 21) was identified as having symptoms of psychosis. Self-report questionnaires were administered at intake and following the completion of a module of DBT skills group, assessing psychiatric symptomatology, emotion regulation, and coping skills acquisition. At baseline, greater levels of psychoticism was significantly associated with more severe difficulties in emotion regulation and poorer coping. After a single module of DBT, individuals with symptoms of psychosis significantly improved in their difficulties with emotion regulation, use of coping skills, and symptoms of psychosis. Baseline levels of psychoticism were not shown to have any detrimental effect on participants’ abilities to improve in any of the target areas. These findings provide preliminary empirical support for the effectiveness of DBT for individuals with psychosis and strengthen the rationale for clinics already offering DBT to this population. Future research is needed to replicate and expand the findings in a larger sample.