Attitudes and access to lung volume reduction surgery for COPD: a survey by the British Thoracic Society.

OBJECTIVE: Lung volume reduction surgery for emphysema leads to improved survival in appropriately selected individuals, and it is therefore recommended in national and international guidelines for this group of patients. Despite this, fewer than 100 patients undergo the procedure each year in the UK. Our objective was to establish whether this reflects concerns about morbidity and mortality or difficulties in the referral pathway. DESIGN AND SETTING: We conducted a survey of members of the British Thoracic Society by email to investigate this in the second half of 2013. The survey included questions about access to investigations, the indications for lung volume reduction surgery (LVRS), whether a multidisciplinary meeting discussed eligibility of patients for LVRS and what the morbidity and mortality associated with the procedure was. RESULTS: There were 65 responses, 82% from respiratory physicians. Roughly half of the respondents were either unsure about the risks of death or prolonged (>30 days) hospital stay involved or significantly over-estimated them. In total, 70% did not have a specific multidisciplinary team to discuss the management of patients with advanced chronic obstructive pulmonary disease (COPD). There was no consensus as to which patients with COPD should undergo a CT scan to evaluate them for possible surgery. CONCLUSIONS: Patients with COPD require a systematic and multidisciplinary approach to assessment for LVRS and these survey data suggest that work is needed to deliver this evidence-based therapy in a consistent and comprehensive way across the UK

Show Me the Data: Statistical Representation

Statistical representation is the science and art of using data to describe the world around us. Statistical representation is based on the fundamental concept that data consists of structure plus noise. The challenge facing the statistician is to use the noisy data to learn about the underlying structure. This framework accommodates the analysis of data generated by almost all other scientific disciplines. There are numerous ways of constructing statistical representations. The methods discussed here include tables, graphs, and models. The proper representation depends on the nature of the data and the particular issues being addressed. A combination of methods is often appropriate

Information usage in the formation of price expectations: theory and econometric tests

Assume that economic agents form expectations rationally by forecasting future prices with the stochastic expectation of price, conditional upon an observed set of information. If information used in forming expectations is considered a scarce resource, profit maximizing agents will acquire additional information until the marginal cost of that activity equals the marginal benefit. Agents engaged in purely productive activities are considered, and it is assumed that there is no opportunity for speculation. The benefits of information usage are shown to depend upon the parameters of the market in which the agent is participating. In certain situations, the information used by one agent may create both positive and negative externalities in the market;If information is considered a costly resource, then one does not expect agents to use all that is available, even if expectations are formed rationally. The applicability of different econometric tests of the hypothesis of rationality are discussed in light of this fact. Special attention is given to estimation and hypothesis testing when the error in the model is serially correlated;An empirical analysis of expectation formation in the chicken broiler market is conducted. The results imply that short run production decisions in this industry do not satisfy the rational expectations model. It is suggested that the value of information to broiler producers is relatively small in the short run because of an inability to make substantial short-run changes in the level of production. A cobweb model of expectation formation performed well in describing producer behavior

An evaluation of Saudi Arabia’s policies for economic diversification

The aim of this thesis is to evaluate Saudi Arabia's policies for diversification. Economic diversification only became a realistic possibility following the first major oil price rise in the early 1970's. Not surprisingly the immediate reaction was to follow the example of western industrialised countries, and consequently very ambitious plans were discussed. This over reaction was soon rationalised. The Second Development Plan covering the 1975-1980 period, laid the foundations for diversifying the economy by providing for the creation of a much needed infrastructure. It vas left to the Third Development Plan covering the 1980-1985 period, to define a selective approach to industrialisation so that only the economically feasible projects remained. It is rather too early to assess just how successful the Third Plan has been. The most that can fairly be asked is: has the Government begun to implement its policies for economic diversification? The abrupt change in revenues almost forced the Government to rely on imports for development if it wished to take immediate action because of its limited domestic economy. Consequently, industrialisation in Saudi Arabia is largely dependent on imports, and most diversification amounts to the implementation of import substitution policies. Export diversification is virtually the export of any goods or services other than oil. It is thus essential to analyse the determinants of imports and exports and to look at recent trends

On the Impossibility to Extend Triples of Mutually Unbiased Product Bases in Dimension Six

An analytic proof is given which shows that it is impossible to extend any triple of mutually unbiased (MU) product bases in dimension six by a single MU vector. Furthermore, the 16 states obtained by removing two orthogonal states from any MU product triple cannot figure in a (hypothetical) complete set of seven MU bases. These results follow from exploiting the structure of MU product bases in a novel fashion, and they are among the strongest ones obtained for MU bases in dimension six without recourse to computer algebra.Comment: 12 pages, identical to published versio

Structure of the proton-gated urea channel from the gastric pathogen Helicobacter pylori.

Half the world's population is chronically infected with Helicobacter pylori, causing gastritis, gastric ulcers and an increased incidence of gastric adenocarcinoma. Its proton-gated inner-membrane urea channel, HpUreI, is essential for survival in the acidic environment of the stomach. The channel is closed at neutral pH and opens at acidic pH to allow the rapid access of urea to cytoplasmic urease. Urease produces NH(3) and CO(2), neutralizing entering protons and thus buffering the periplasm to a pH of roughly 6.1 even in gastric juice at a pH below 2.0. Here we report the structure of HpUreI, revealing six protomers assembled in a hexameric ring surrounding a central bilayer plug of ordered lipids. Each protomer encloses a channel formed by a twisted bundle of six transmembrane helices. The bundle defines a previously unobserved fold comprising a two-helix hairpin motif repeated three times around the central axis of the channel, without the inverted repeat of mammalian-type urea transporters. Both the channel and the protomer interface contain residues conserved in the AmiS/UreI superfamily, suggesting the preservation of channel architecture and oligomeric state in this superfamily. Predominantly aromatic or aliphatic side chains line the entire channel and define two consecutive constriction sites in the middle of the channel. Mutation of Trp 153 in the cytoplasmic constriction site to Ala or Phe decreases the selectivity for urea in comparison with thiourea, suggesting that solute interaction with Trp 153 contributes specificity. The previously unobserved hexameric channel structure described here provides a new model for the permeation of urea and other small amide solutes in prokaryotes and archaea

THE USE OF INVERSE THEORY ON AN ILL-POSED ENVIRONMENTAL COMPOSITE SAMPLING PROBLEM

As an alternative to retesting, the use of inverse theory techniques is proposed to resolve the lack of information inherent in composite sampling methods. This paper evaluates the feasibility of combining composite sampling with the inverse theory technique of linear regularization on an environmental site characterization investigation. Federal legislation has mandated the cleanup of hazardous waste sites, creating the need to characterize these sites for various chemical constituents. An abundance of samples, high measurement costs, and limited budgets create the appeal of compositing samples. We propose that the number of costly laboratory analyses can be reduced by combining composite sampling and inverse theory techniques. The goal of the paper is to estimate the constituent concentration for the sample units used to construct the composite . A novel application of linear regularization is illustrated with a data set from an environmental investigation into mercury contamination at a waste disposal site in New Mexico. The disposal site has measurements at both the composite and sample unit level. This allows for a rare opportunity to evaluate the assumptions made about the compositing process and to compare estimates based on composite measurements with estimates based on sample unit measurements

The Efficacy of Peripheral Opioid Antagonists in Opioid-Induced Constipation and Postoperative Ileus: A Systematic Review of the Literature.

Opioid-induced constipation has a negative impact on quality of life for patients with chronic pain and can affect more than a third of patients. A related but separate entity is postoperative ileus, which is an abnormal pattern of gastrointestinal motility after surgery. Nonselective μ-opioid receptor antagonists reverse constipation and opioid-induced ileus but cross the blood-brain barrier and may reverse analgesia. Peripherally acting μ-opioid receptor antagonists target the μ-opioid receptor without reversing analgesia. Three such agents are US Food and Drug Administration approved. We reviewed the literature for randomized controlled trials that studied the efficacy of alvimopan, methylnaltrexone, and naloxegol in treating either opioid-induced constipation or postoperative ileus. Peripherally acting μ-opioid receptor antagonists may be effective in treating both opioid-induced bowel dysfunction and postoperative ileus, but definitive conclusions are not possible because of study inconsistency and the relatively low quality of evidence. Comparisons of agents are difficult because of heterogeneous end points and no head-to-head studies

Developing and testing accelerated partner therapy for partner notification for people with genital Chlamydia trachomatis diagnosed in primary care: a pilot randomised controlled trial

Background Accelerated partner therapy (APT) is a promising partner notification (PN) intervention in specialist sexual health clinic attenders. To address its applicability in primary care, we undertook a pilot randomised controlled trial (RCT) of two APT models in community settings. Methods Three-arm pilot RCT of two adjunct APT interventions: APTHotline (telephone assessment of partner(s) plus standard PN) and APTPharmacy (community pharmacist assessment of partner(s) plus routine PN), versus standard PN alone (patient referral). Index patients were women diagnosed with genital chlamydia in 12 general practices and three community contraception and sexual health (CASH) services in London and south coast of England, randomised between 1 September 2011 and 31 July 2013. Results 199 women described 339 male partners, of whom 313 were reported by the index as contactable. The proportions of contactable partners considered treated within 6 weeks of index diagnosis were APTHotline 39/111 (35%), APTPharmacy 46/100 (46%), standard patient referral 46/102 (45%). Among treated partners, 8/39 (21%) in APTHotline arm were treated via hotline and 14/46 (30%) in APTPharmacy arm were treated via pharmacy. Conclusions The two novel primary care APT models were acceptable, feasible, compliant with regulations and capable of achieving acceptable outcomes within a pilot RCT but intervention uptake was low. Although addition of these interventions to standard PN did not result in a difference between arms, overall PN uptake was higher than previously reported in similar settings, probably as a result of introducing a formal evaluation. Recruitment to an individually randomised trial proved challenging and full evaluation will likely require service-level randomisation