Evidence for quantum confinement in the photoluminescence of porous Si and SiGe

We have used anodization techniques to process porous surface regions in p-type Czochralski Si and in p-type Si0.85Ge0.15 epitaxial layers grown by molecular beam epitaxy. The SiGe layers were unrelaxed before processing. We have observed strong near-infrared and visible light emission from both systems. Analysis of the radiative and nonradiative recombination processes indicate that the emission is consistent with the decay of excitons localized in structures of one or zero dimensions

Debate:Challenges in sports cardiology; US versus European approaches

For practitioners working with elite athletes, the field of sports cardiology provides clinical, academic, administrative and fiscal challenges. These challenges are exemplified and reinforced by the lack of consistency and consensus both in the literature and academic presentations. Through thepresentation of a series of clinical questions, this debate attempts to ‘cut to the chase’ on cardiovascular issues relevant to the clinician dealing with elite athletes. In so doing, we hope to crystallize some of the most important elements of the complex cardiological management of elite athletes, in a concise, readable format. Frequently over the last 10 years, many of the controversies in this field have been (rightly or wrongly) presented in aEurope versus USA paradigm. We have chosen to test whether there really are polarised views across the Atlantic, by deliberately pitting specialists from the USA against those from the UK. Professors Levine and Thompson are both internationally recognised sports cardiologists, with immense academic and clinical credibility, and who will represent the ‘US approach’. Professor Whyte and Doctor Wilson are cardiac physiologists with a wealth of experience in the testing, evaluation and screening of elite athletes, and who have equally impressive academic credibility and for the purposes of this debate, they will be representing the ‘European approach’. To initiate this process, each team was required to provide a concise answer (circa 200–300 words) to a series of fiveclinical conundrums. Subsequently, each team had the opportunity to provide a rebuttal to the opposing team’s answers, and the following reflects the consolidation of those answers

Football Banning Orders: The Highly Effective Cornerstone of a Preventative Strategy?

The chapter examines the development, use and effectiveness of football banning orders in the UK, comparing their use in England to address issues of football 'hooliganism' with their distinct evolution in Scotland to address concerns around sectarian disorder

A multi-lake comparative analysis of the General Lake Model (GLM): Stress-testing across a global observatory network

The modelling community has identified challenges for the integration and assessment of lake models due to the diversity of modelling approaches and lakes. In this study, we develop and assess a one-dimensional lake model and apply it to 32 lakes from a global observatory network. The data set included lakes over broad ranges in latitude, climatic zones, size, residence time, mixing regime and trophic level. Model performance was evaluated using several error assessment metrics, and a sensitivity analysis was conducted for nine parameters that governed the surface heat exchange and mixing efficiency. There was low correlation between input data uncertainty and model performance and predictions of temperature were less sensitive to model parameters than prediction of thermocline depth and Schmidt stability. The study provides guidance to where the general model approach and associated assumptions work, and cases where adjustments to model parameterisations and/or structure are required

Sicca symptoms and their association with chronic rhinosinusitis in a community sample

Abstract: Objective: To determine associations between sicca symptoms, chronic rhinosinusitis (CRS) symptoms and asthma in a community survey. Methods: Data was obtained from the Spring 2009 South Australian Health Omnibus Survey which sampled, via interviewer administered questionnaire, 3007 individuals aged 15 years and over whose socio-demographic distribution corresponded to South Australian population estimates. Respondents were asked a range of questions relating to the presence of persistent dry eyes or dry mouth, CRS and medically diagnosed nasal polyps and asthma. Relationships between symptoms were explored using maximum likelihood dependency tree analysis. Results: The respective population prevalences were: dry mouth (5.9%), dry eyes (8.6%), nasal polyps (3.8%), CRS (13.2%) and asthma (12.0%). The overall prevalence of sicca symptoms (dry eyes or dry mouth) was 12.4%. Dependency tree analysis revealed the expected symptom clustering between (1) sicca symptoms and their association with female gender and increasing age and (2) CRS, nasal polyps and asthma (one airway hypothesis). However there was also an association between dry eyes and CRS (OR 2.5, 95% CI 1.9, 3.4), which was in fact stronger than the association between CRS and asthma (OR 1.9, 95% CI 1.4, 2.5). Conclusions: Sicca symptoms are common in the community. Our novel finding of a strong association between dry eyes and CRS suggests that further research into the relationship between airway inflammation and sicca symptoms is required. These findings may have particular relevance to Sjögren’s syndrome (SS) in both its primary and secondary forms.S. Lester, M. Rischmueller, L.W. Tan, P.J. Wormald, P. Zalewski, M.A. Hamilton-Bruce, S. Appleton, R.J. Adams and C.L. Hil

A Phase I and Pharmacologic Study of Weekly Gemcitabine in Combination with Infusional 5-fluorodeoxyuridine and Oral Calcium Leucovorin

Purpose: Since preclinical studies have shown more than additive cytotoxicity and DNA damage with the combination of gemcitabine and 5-fluoro-2′-deoxyuridine (FUDR), we studied this combination in a phase I trial. Methods: Gemcitabine alone was given in cycle 1 as a 24-h, 2-h or 1-h i.v. infusion weekly for 3 of 4 weeks; if tolerated, a 24-h i.v. infusion of FUDR was added with oral leucovorin. The cycle was aborted for grade 3 thrombocytopenia, grade 4 neutropenia, and grade 2 or worse nonhematologic toxicity. Results: During cycle 1, six of eight patients who received 150 or 100 mg/m2 over 24 h had dose-limiting neutropenia, thrombocytopenia, fatigue or mucositis. Six of seven patients treated with 1000 mg/m2 over 2 h required a gemcitabine dose reduction for cycle 2 (thrombocytopenia, neutropenia, fatigue). Of 25 assessable patients who received gemcitabine 1000 mg/m2 over 1 h, 7 did not complete cycle 1 due to thrombocytopenia (n = 6) or diarrhea (n = 1). Of 42 patients entered, 27 received at least one course of gemcitabine/FUDR (5-19.5 mg/m2 over 24 h) without appreciable toxicity. Due to a shortage of FUDR, the protocol was closed early. Gemcitabine plasma concentrations averaged 0.061 μM (24 h), 16.3 μM (2 h), and 31.9 μM (1 h). In 21 paired bone marrow mononuclear cell samples obtained before treatment and during FUDR infusion, thymidylate synthase ternary complex was only seen during FUDR infusion. Conclusions: Gemcitabine 100-150 mg/m2 over 24 h was poorly tolerated, whereas toxicity was acceptable with 800-1000 mg/m2 over 1 h. Inhibition of the target enzyme was demonstrated at all FUDR doses

An Analysis of Private School Closings

We add to the small literature on private school supply by exploring exits of K-12 private schools. We find that the closure of private schools is not an infrequent event, and use national survey data from the National Center for Education Statistics to study closures of private schools. We assume that the probability of an exit is a function of excess supply of private schools over the demand, as well as the school's characteristics such as age, size, and religious affiliation. Our empirical results generally support the implications of the model. Working Paper 07-0