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

The Evolution of Religion: How Cognitive By-Products, Adaptive Learning Heuristics, Ritual Displays, and Group Competition Generate Deep Commitments to Prosocial Religio

Understanding religion requires explaining why supernatural beliefs, devotions, and rituals are both universal and variable across cultures, and why religion is so often associated with both large-scale cooperation and enduring group conflict. Emerging lines of research suggest that these oppositions result from the convergence of three processes. First, the interaction of certain reliably developing cognitive processes, such as our ability to infer the presence of intentional agents, favors—as an evolutionary by-product—the spread of certain kinds of counterintuitive concepts. Second, participation in rituals and devotions involving costly displays exploits various aspects of our evolved psychology to deepen people's commitment to both supernatural agents and religious communities. Third, competition among societies and organizations with different faith-based beliefs and practices has increasingly connected religion with both within-group prosociality and between-group enmity. This connection has strengthened dramatically in recent millennia, as part of the evolution of complex societies, and is important to understanding cooperation and conflict in today's world.by-product hypothesis, credibility enhancing displays, cultural 40 transmission, cooperation, group competition, high gods,min

Power Spectrum Constraints from Spectral Distortions in the Cosmic Microwave Background

%The content of this replacement paper is identical to the original. %We have attempted to fix the postscript so that it will print out on %a larger number of printers. Using recent experimental limits on $\mu$ distortions from COBE FIRAS, and the large lever-arm spanning the damping of sub-Jeans scale fluctuations to the scale of the COBE DMR fluctuations, we set a constraint on the slope of the primordial power spectrum $n$. It is possible to analytically calculate the contribution over the full range of scales and redshifts, correctly taking into account fluctuation growth and damping as well as thermalization processes. We find that the 95\% upper limit is weakly dependent on cosmological parameters, e.g. $n<1.54 (h=0.5)$ and $n<1.56 (h=1.0)$ for $\Omega_0=1$ with marginally weaker constraints for $\Omega_0<1$ in a flat $\Omega_0 +\Omega_\Lambda=1$ universe.Comment: 8pg, uuencoded-tarred (& hopefully more compatible!) postscript, CfPA-TH-94-1

On the optimality of interest-bearing reserves in economies of overlapping generations

Econometrics

Should bank reserves earn interest?

This article examines the effects and desirability of paying interest on required reserves. Scott Freeman and Joseph Haslag demonstrate that a policy of paying interest on reserves can make everyone better off, even if the interest must be financed by a tax on capital. An essential part of this policy is an open market operation that offsets any changes in the value of money.Bank reserves

Constructing an alternative measure of changes in reserve requirement ratios

Bank reserves

13 + 1: A Comparison of Global Climate Change Policy Architectures

We critically review the Kyoto Protocol and thirteen alternative policy architectures for addressing the threat of global climate change. We employ six criteria to evaluate the policy proposals: environmental outcome, dynamic efficiency, cost effectiveness, equity, flexibility in the presence of new information, and incentives for participation and compliance. The Kyoto Protocol does not fare well on a number of criteria, but none of the alternative proposals fare well along all six dimensions. We identify several major themes among the alternative proposals: Kyoto is “too little, too fast”; developing countries should play a more substantial role and receive incentives to participate; implementation should focus on market-based approaches, especially those with price mechanisms; and participation and compliance incentives are inadequately addressed by most proposals. Our investigation reveals tensions among several of the evaluative criteria, such as between environmental outcome and efficiency, and between cost-effectiveness and incentives for participation and compliance.policy architecture, Kyoto Protocol, efficiency, cost effectiveness, equity,participation, compliance