An investigation of the progression from Barrett's esophagus to adenocarcinoma

Barrett's esophagus is a metaplasia of the epithelium of the lower esophagus from a normal squamous appearance to a columnar appearance more typically found in the stomach. It is normally caused by prolonged gastric reflux. While Barrett's esophagus is not usually the direct cause of adverse symptoms, it does put a person at greater risk for developing esophageal adenocarcinoma, one of the least treatable cancers currently known. While the progression from gastric reflux to Barrett's esophagus is fairly clear, the relationship between Barrett's esophagus and esophageal adenocarcinoma is not as well understood. Not all patients diagnosed with Barrett's esophagus will go on to develop esophageal adenocarcinoma. There are several factors that may have some impact on this progression, including obesity, lifestyle, and genetic predisposition. The purpose of this study was to evaluate the literature to determine the potential impacts of each of these factors on development of esophageal adenocarcinoma. While obesity and lifestyle clearly have some impact on development of esophageal adenocarcinoma, it was found that the exact nature of that impact is still unclear. Obesity leads to several consequences, including increased gastroesophageal reflux, hormonal changes, and reduction in the bacterium H. pylori, all of which have been shown to have some impact on metaplasia in the esophagus. Lifestyle choices, including alcohol or tobacco use, also have been shown to have at least some effect on development of esophageal adenocarcinoma. The literature also reveals that inherited risk factors, namely genetic predisposition, may play a role in development of esophageal adenocarcinoma. Genetic predisposition to obesity may have some impact, but other studies have identified genetic variations that seem to directly influence development of esophageal adenocarcinoma. While it is clear that there are several factors that influence development of esophageal adenocarcinoma, we do not yet understand the complete etiology. By continuing to study these risk factors, we will be able to develop new treatments to combat the rising incidence of Barrett's esophagus and esophageal adenocarcinoma

Unveiling the unseen with the Dark Energy Survey: gravitational waves and dark matter

In this thesis I show how large galaxy surveys, in particular the study of the properties of galaxies, can shed light on gravitational wave sources and dark matter. This is achieved using the latest data from the Dark Energy Survey, an on-going 5000 deg2 optical survey. Galaxy properties such as photometric redshifts and stellar masses are derived through spectral energy distribution fitting methods. The results are used to study host galaxies of gravitational wave events and how light traces dark matter in galaxy clusters. Gravita- tional wave (GW) science, and particularly the electromagnetic follow up of these events, is transforming what had never been seen into a new astronomical field able to unveil the nature of cataclysmic events. Identifying the galaxies that host these events, and es- timating their redshift, stellar mass, and star–formation rate, is crucial for cosmological analysis with gravitational waves, for follow up studies and to understand the formation of the binary systems that are thought to produce observable gravitational wave signals. This thesis describes how the host matching is implemented within the DES–GW pipeline and how observations of NGC 4993, the galaxy host of the event GW170817, provide important information about possible formation scenarios for binary neutron stars. In particular, we find that NGC 4993 presents shell structures and we relate their formation to the binary formation. The same galaxy properties are used to derive an observable mass proxy for galaxy clusters. I show that this mass observable correlates well with the total mass of clusters, which is mainly composed of dark matter. It can therefore be used for cosmological studies with galaxy clusters. The measurement of stellar–to–halo mass relations in clusters provides insights on the connection between the star content and the total matter content in clusters, and how this evolves over cosmic time

John Adams Composing Through Others: Modeling, Innovation, and Recomposition

John Adams has frequently embedded allusions to the music of others in his work while also drawing on more general stylistic conventions and sensibilities of others to inform his creative output. Although this dynamic has been widely acknowledged in Adams’s body of work by scholars and critics generally, it has received little sustained attention or explanation. I argue that much of his work involves “composing through others,” a process in which he adopts, in various ways, the aesthetic conventions, styles, and sensibilities of other composers. By unearthing traces of this creative approach through a focus on short, but significant, periods of his career, we can craft a more nuanced picture of Adams’s stylistic development. The title of this dissertation suggests three ways in which Adams has composed through others: modeling, innovation, and recomposition. Modeling involves the outright adoption or mimicking of other composers’ styles, a conspicuous feature of his earliest compositions, which were written in the early- and mid-1970s. Innovation, in this dissertation, refers to the process by which Adams has cultivated new styles and subjected them to testing and development; this process gave rise to Adams’s first large-scale ensemble works during the late 1970s and early 1980s. Recomposition was his most straightforward strategy for composing through others in the late 1980s and early 1990s; he orchestrated the music of past composers as an exercise in revision and elaboration, using the process to help chart new paths forward in composing original works

Strangeness production in heavy-ion collisions

A study of the "horn" in the particle ratio $K^+/\pi^+$ for central heavy-ion collisions as a function of the collision energy $\sqrt{s}$ is presented. We analyse two different interpretations: the onset of deconfinement and the transition from a baryon- to a meson-dominated hadron gas. We use a realistic equation of state (EOS), which includes both hadron and quark degrees-of-freedom. The Taub-adiabate procedure is followed to determine the system at the early stage. Our results do not support an explanation of the horn as due to the onset of deconfinement. Using only hadronic EOS we reproduced the energy dependence of the $K^+/\pi^+$ and $\Lambda/\pi^-$ ratios employing an experimental parametrisation of the freeze-out curve. We observe a transition between a baryon- and a meson-dominated regime; however, the reproduction of the $K^+/\pi^+$ and $\Lambda/\pi^-$ ratios as a function of $\sqrt{s}$ is not completely satisfying. We finally propose a new idea for the interpretation of the data, the roll-over scheme, in which the scalar meson field $\sigma$ has not reached the thermal equilibrium at freeze-out. The rool-over scheme for the equilibration of the $\sigma$-field is based on the inflation mechanism. The non-equilibrium evolution of the scalar field influences the particle production, e.g. $K^+/\pi^+$, however, the fixing of the free parameters in this model is still an open issue.Comment: 10 pages, 7 figures, 9th International Workshop on Critical Point and Onset of Deconfinement, 17-21 November, 201

New furan-based thermosetting polymer systems

Furan building blocks for chemicals and polymers are derived from the processing of cellulose and hemicellulose. A new family of furan-based thermosetting materials will be discussed. Furfuryl amine (FA) was coupled using aldehydes and di-aldehydes to form di-furan di-amine (DFDA) and terra-furan tetra-amine (TFTA) molecules containing two or four furan rings respectively (Figure 1). These amines form the basis for epoxy, benzoxazine, and polyimide thermosetting systems with unique properties (Figure 2). Furan-based epoxy amine systems were found to possess higher density and Young’s modulus (\u3e5 GPa), as well as higher yield strength (\u3e150 MPa in compression) and high char-yield compared to traditional epoxies. Benzoxazine monomers were synthesized by reacting DFDA’s with a number of phenolic compounds and formaldehyde resulting in solid powders that melt at temperatures ranging between 70°C and 150°C to form low-viscosity liquids. Onset cure temperature varied in the range of 120°C-240°C depending on composition. The resulting polybenzoxazine systems possess Tg’s ranging from 220°C to 280°C and char-yield as high as 70% measured at 800°C by TGA in an inert environment. DFDA was also used to prepare nadic end-capped polyimides analogous to PMR-15. These materials were found to process high Tg (\u3e330°C) and excellent processing characteristics because of low melt viscosity and facile imidization. This family of thermosetting systems could provide additional capability for composite, coating, and adhesive applications that require good ambient performance characteristics as well as good thermal management in extreme environments. Please click Additional Files below to see the full abstract

Standard Siren Cosmology with Gravitational Waves from Binary Black Hole Mergers in Active Galaxy Nuclei

The detection of gravitational waves (GW) with an electromagnetic counterpart enabled the first Hubble Constant $H_0$ measurement through the standard siren method. Current constraints suggest that $\sim 20-80\%$ of LIGO/Virgo/KAGRA (LVK) Binary Black Hole (BBH) mergers occur in Active Galactic Nuclei (AGN) disks. The claim for a possible association of several BBH mergers with flaring AGNs suggests that cosmological analyses using BBH and AGNs might be promising. We explore standard siren analyses through a method that takes into account the presence of background flaring AGNs, without requiring a unique host galaxy identification, and apply it to realistic GW simulations. Depending on the fraction of LVK BBHs that induce flares, we expect to constrain $H_0$ at the $\sim 3.5-7\%$ ($\sim 2.5-5\%$) precision with $\sim 2$ years or $\sim 160$ events ($\sim 1$ year or $500$ events) of LVK at design (A+) sensitivity, assuming that systematic BBH follow-up searches are performed. Assuming a more restrictive $\Omega_{\rm m}$ prior and that at least $20\%$ of BBHs produces detectable flares, we may reach a $3\%$ ($2\%$) precision in $H_0$ after 2 (1) year of LVK at design (A+) sensitivity. We also show that a $\sim 5-10\%$ precision is possible with complete AGN catalogs and 1 year of LVK run, without the need of time-critical follow-up observations.Comment: 14 pages, 5 figure