Is the New Keynesian Explanation of the Great Dis-Inflation Consistent with the Cross Country Data?

A leading explanation of long run U.S. inflation trends attributes both the fall of inflation in the 1980s and the subsequent years of low and stable inflation to well run monetary policy pinning down inflationary expectations. Most other OECD economies experienced a similar rise and fall of inflation, as well as subsequent low and stable inflation over the same period. This observation has been under-explored in the literature. In this paper we exploit the international dimension of the fall of inflation to investigate the hypothesis that good monetary policy is responsible for recent inflation outcomes. Our results suggest that this theory is not compatible with the cross country data.

A Combinatorial Exploration of Elliptic Curves

At the intersection of algebraic geometry, number theory, and combinatorics, an interesting problem is counting points on an algebraic curve over a finite field. When specialized to the case of elliptic curves, this question leads to a surprising connection with a particular family of graphs. In this document, we present some of the underlying theory and then summarize recent results concerning the aforementioned relationship between elliptic curves and graphs. A few results are additionally further elucidated by theory that was omitted in their original presentation

DEIMOS Observations of WISE-Selected, Optically Obscured AGNs

While there are numerous criteria for photometrically identifying active galactic nuclei (AGNs), searches in the optical and UV tend to exclude galaxies that are highly dust obscured. This is problematic for constraining models of AGN evolution and estimating the AGN contribution to the cosmic X-ray and IR backgrounds, as highly obscured objects tend to be underrepresented in large-scale surveys. To address this, we identify potentially obscured AGNs using mid-IR color colors from the Wide-field Infrared Survey Explorer (WISE) catalog. This paper presents the results of optical spectroscopy of obscured AGN candidates using Keck DEIMOS, and their physical properties derived from these spectra. We find that a $W1-W2>0.8$ color criterion effectively selects AGNs with a higher median level of $E(B-V)$ extinction compared to the AGNs found in the SDSS DR7 survey. This optical extinction can be measured using SED modeling or by using $r-W1$ as a measure of optical to IR flux. We find that specific, targeted observations are necessary to find the most highly optically obscured AGNs, and that additional far-IR photometry is necessary to further constrain the dust properties of these AGNs.Comment: 20 pages, 25 figures, accepted by MNRA

Analytic treatment of controlled reversible inhomogeneous broadening quantum memories for light using two-level atoms

It has recently been discovered that the optical analog of a gradient echo, in an optically thick material, could form the basis of an optical memory that is both completely efficient and noise-free. Here we present analytical calculations showing that this is the case. There is close analogy between the operation of the memory and an optical system with two beam splitters. We can use this analogy to calculate efficiencies as a function of optical depth for a number of quantum memory schemes based on controlled inhomogeneous broadening. In particular, we show that multiple switching leads to a net 100% retrieval efficiency for the optical gradient echo even in the optically thin case

The Sensitivity of Estimates of Post-Apartheid Changes in South African Poverty and Inequality to key Data Imputations

We begin by summarising the literature that has assessed medium-run changes in poverty and inequality in South Africa using census data. According to this literature, over the 1996 to 2001 period both poverty and inequality increased. In this paper we assesses the robustness of these results to the large percentage of individuals and households in both censuses for whom personal income data is missing and to the fact that personal income is collected in income bands rather than as point estimates. First, we use a sequential regression multiple imputation approach to impute missing values for the 2001 census data. Relative to the existing literature, the imputation results lead to estimates of mean income and inequality (as measured by the Gini coefficient) that are higher and estimates of poverty that are lower. This is true even accounting for the wider confidence intervals that arise from the uncertainty that the imputations bring into the estimation process. Next we go on to assess the influence of dubious zero values by setting them to missing and re-doing the multiple imputation process. This increases the uncertainty associated with the imputation process as reflected in wider confidence intervals on all estimates and only the Gini coefficient is significantly different from the first set of estimated parameters. The final imputation exercise assesses the sensitivity of results to the practice of taking personal incomes recorded in bands and attributing band midpoints to them. We impute an alternative set of intra-band point incomes by replicating the intra-band empirical distribution of personal incomes from a national income and expenditure survey undertaken in the year before each census. Using the empirical distributions increases estimated inequality although the differences are relatively small. We finish our empirical work with a discussion of provincial poverty shares as a policy relevant illustration of the importance of dealing with missing values. Overall our results for 1996 and 2001 confirm the major findings from the existing literature while generating more reliable confidence intervals for the key parameter of interest than are available elsewhere.

The Role of Phenotyping in the Personalised Management of OSA

Background: Obstructive sleep apnoea (OSA) is estimated to affect up to 1 billion people in the world. Those who fail first-line continuous positive airway pressure (CPAP) therapy have salvage treatment options available. Patient assessment can incorporate multidisciplinary teams to better select therapy. Traditional parameters that define OSA severity do not always correlate with symptoms of the disease. Newly identified pathophysiological “phenotypes” of airway vulnerability, low arousal threshold, loop gain and muscle responsiveness may explain the heterogeneity of OSA for up to two-thirds of patients. Little data exists on the effectiveness of phenotyping in a real-world clinical setting for patients undergoing contemporary management paradigms. Aims and Hypothesis: To evaluate the prevalence of the four OSA phenotypic traits and explore the clinical validity of endotyping in predicting future treatment outcomes. It is expected that non-responders to treatment will have unfavourable non-anatomical phenotypes. Design: An observational prospective cohort study of 49 patients referred after failure of CPAP for consideration of salvage therapy was conducted. Treatments included upper airway surgery (n = 17), mandibular advancement splint (n = 7), positional therapy (n = 7), weight loss (n = 4), nerve stimulation (n = 5) and combination therapy (n = 9). Treatment “success” was defined using polysomnographic parameters and patient-reported outcome measures of sleepiness and function. Phenotypic traits were analysed according to these outcomes. Results: Nearly all surgical patients had unfavourable loop gain (LG1 \u3e 0.72), which improved after surgical treatment (p \u3c .05). Patients who had decreased sleepiness (Epworth Sleepiness Scale reduction ≥ 3, total score \u3c 10, p = .01) after any treatment had favourable traits of low loop gain, lower arousal threshold and lower muscle compensation. There may be a potential role for phenotyping in predicting expected outcomes from salvage treatment for OSA, although more prospective clinical data is required to further investigate its utility and relevance

Cytotoxic activity of Fagonia cretica against human breast cancer cells

In many parts of the world, plants are directly utilised for their medicinal properties. Traditional medicine from Pakistan, India and the Far East is well documented and its history is embedded in folklore. It has been documented that an aqueous extract of the desert shrub, Fagonia cretica, is a popular treatment for breast cancer in Pakistan. The administration of an aqueous extract of Fagonia cretica is reported effective at reducing tumour size and improving the quality of life of breast cancer patients, is well tolerated and does not exhibit adverse effects like vomiting, diarrhoea or alopecia which are common side effects of standard cytotoxic therapy. In the past, many pharmacologically active and chemotherapeutic compounds have been isolated from plants which subsequently have proven to be successful in clinical trials and been used as primary compounds in therapeutic regimes. Fagonia cretica has historical use as a treatment for breast cancer, yet there is little scientific evidence which shows chemotherapeutic potential towards breast tumours. Preparation and analysis of an aqueous extract of Fagonia cretica may reveal novel chemotherapeutic agents that can be used to effectively target cancer cells. An understanding of the mechanism of any activity may improve our understanding of cancer cell biology and reveal novel therapeutic targets. This thesis describes for the first time that an aqueous extract of Fagonia cretica shows potent in vitro cytotoxic activity towards breast cancer epithelial cell lines which was not seen towards normal mammary epithelial cells. Elucidation and characterisation of the cytotoxic mechanism was undertaken by analysing DNA damage, cell cycle status, apoptosis, metabolic state and expression of transcription factors and their targets. Finally, methods for the isolation and identification of active compound(s) were developed using various chromatographic techniques. An aqueous extract of Fagonia cretica was able to reduce cell viability significantly in two phenotypically different breast cancer cell lines (MCF-7 and MDA-MB-231). This activity was markedly reduced in normal mammary epithelial cells (HMEpC). Further investigation into the mode of action revealed that extract treatment induced cell cycle arrest and apoptosis in both MCF-7 and MDA-MB-231 cell lines. This coincided with the formation of DNA double stranded breaks and the DNA repair marker ?-H2AX. In MCF-7 cells, ATM/ATR activation resulted in increased p53 expression and of its transcriptional targets p21 and bax, suggesting a role for a p53-mediated response. Furthermore, inhibition of extract-induced p53 expression with siRNA reduced the cytotoxic effect against MCF-7 cells. Extract treatment was also associated with increased FOXO3a expression in MCF-7 and MDA-MB-231 cells. In the absence of functional p53, siRNA knockdown of extract-induced FOXO3a expression was completely abrogated, suggesting that FOXO3a plays a vital role in extract-induced cytotoxicity. Isolation and characterisation of the active compound(s) within the extract was attempted using liquid chromatography and mass spectrometry in conjunction with a cell viability assay. Multiple fractionations generated an active fraction that contained four major compounds as detected by mass spectrometry. However, none of these compounds were identified structurally or chemically due to constraints within the methodology

A Model of Internet Consumer Satisfaction: Focusing on the Web-site design

Since the trend of doing business on line has become more and more common among different sizes of companies and industries, measuring the antecedents of web site design is important to both practitioners and researchers. Achieving customer satisfaction is the ultimate goal of electronic commerce so to guarantee on line purchases. Based on the research models and factors proposed by previous studies on customer satisfaction and Web interface design, a new model is developed in this paper. This model shows how various antecedent factors affect consumer satisfaction towards Internet shopping through the intermediate construct of a successful Web- site design