Automatic measurement of vertebral rotation in idiopathic scoliosis

Study Design. Development of an automatic measurement algorithm and comparison with manual measurement methods. Objectives. To develop a new computer-based method for automatic measurement of vertebral rotation in idiopathic scoliosis from computed tomography images and to compare the automatic method with two manual measurement techniques. Summary of Background Data. Techniques have been developed for vertebral rotation measurement in idiopathic scoliosis using plain radiographs, computed tomography, or magnetic resonance images. All of these techniques require manual selection of landmark points and are therefore subject to interobserver and intraobserver error. Methods. We developed a new method for automatic measurement of vertebral rotation in idiopathic scoliosis using a symmetry ratio algorithm. The automatic method provided values comparable with Aaro and Ho's manual measurement methods for a set of 19 transverse computed tomography slices through apical vertebrae, and with Aaro's method for a set of 204 reformatted computed tomography images through vertebral endplates. Results. Confidence intervals (95%) for intraobserver and interobserver variability using manual methods were in the range 5.5 to 7.2. The mean (+/- SD) difference between automatic and manual rotation measurements for the 19 apical images was -0.5 degrees +/- 3.3 degrees for Aaro's method and 0.7 degrees +/- 3.4 degrees for Ho's method. The mean (+/- SD) difference between automatic and manual rotation measurements for the 204 endplate images was 0.25 degrees +/- 3.8 degrees. Conclusions. The symmetry ratio algorithm allows automatic measurement of vertebral rotation in idiopathic scoliosis without intraobserver or interobserver error due to landmark point selection.

A prospective assessment of SRS-24 scores after endoscopic anterior instrumentation for scoliosis

Study Design. Prospective clinical case series. Objective. To evaluate the clinical outcome of anterior endoscopic instrumention for scoliosis using the SRS-24 questionnaire and to examine how these scores change over a 2-year follow-up period. Summary of Background Data. Anterior endoscopic instrumentation correction has several advantages compared with open procedures. However, the clinical results of this technique using a validated outcome measure have rarely been reported in the literature. Methods. A total of 83 consecutive patients underwent endoscopic anterior instrumentation performed at a single unit. Patients completed the SRS-24 questionnaire before surgery and at 3, 6, 12, and 24 months after surgery. The SRS-24 scores were compared between each of the follow-up intervals. Results. The pain, general self-image, and function from back condition domains improved after surgery (P < 0.05). Activity level significantly improved between 3 and 6 months, and both function domains improved between 6 and 12 months (P < 0.05). None of the domains increased significantly after 1 year. Conclusions. Endoscopic anterior instrumentation for scoliosis significantly improved pain, self-image, and function. The greatest improvement in function occurred between 6 and 12 months after surgery. The SRS-24 scores at 1 year from surgery may provide a good indicator of patient outcome in the long-term.

Dynamic models of exchange rate dependence using option prices and historical returns

Models for the conditional joint distribution of the U.S. Dollar/Japanese Yen and Euro/Japanese Yen exchange rates, from November 2001 until June 2007, are evaluated and compared. The conditional dependency is allowed to vary across time, as a function of either historical returns or a combination of past return data and option-implied dependence estimates. Using prices of currency options that are available in the public domain, risk-neutral dependency expectations are extracted through a copula repre- sentation of the bivariate risk-neutral density. For this purpose, we employ either the one-parameter \Normal" or a two-parameter \Gumbel Mixture" specification. The latter provides forward-looking information regarding the overall degree of covariation, as well as, the level and direction of asymmetric dependence. Specifications that include option-based measures in their information set are found to outperform, in-sample and out-of-sample, models that rely solely on historical returns.

Synthesis of pyridine-stretched 2′-deoxynucleosides

Synthesis of novel pyridine-stretched nucleoside (PSN) analogues of adenine (strA) (1), 2,6-diaminopurine (strD) (15) and hypoxanthine (strH) (17) from 4(5)-nitroimidazole has been achieved. Glycosylation of 4(5)-nitroimidazole was optimized to give consistently good yields (>70%) of the desired analytically pure 5-nitro-1′-β isomer 8 which on hydrogenation, C-addition of ethoxymethylene malononitrile (EMMN) and cyclisation provides the key intermediate 14 for PSN synthesis.

Anatomy and lessons of the global financial crisis. Is US consumption financed by Chinese savings?

Savings and investments in the American money market by emerging countries, primarily China, financed the excessive consumption of the United States in the early 2000s, which indirectly led to a global financial crisis. The crisis started from the real estate mortgage market. Such balance disrupting processes began on the American financial market which contradicted all previously known equilibrium theories of every school of economics. Economics has yet to come up with models or empirical theories for this new disequilibrium. This is why the outbreak of the crisis could not be prevented or at least predicted. The question is, to what extent can existing market theories, calculation methods and the latest financial products be held responsible for the new situation. This paper studies the influence of the efficient market and modern portfolio theory, as well as Li’s copula function on the American investment market. Naturally, the issues of moral risks and greed, credit ratings and shareholder control, limited liability and market regulations are aspects, which cannot be ignored. In summary, the author outlines the potential alternative measures that could be applied to prevent a new crisis, defines the new directions of economic research and draws the conclusion for the Hungarian economic policy.

Relative significance of pelagic, benthic and allochthonous organic matter to microbial carbon cycling in a phosphorus-depleted subtropical estuary (Florida Bay)

Heterotrophic bacteria are important decomposers and transformers of primary production and provide an important link between detritus and the aquatic food web. In seagrass ecosystems, much of seagrass primary production is unavailable through direct grazing and must undergo microbial reworking before seagrass production can enter the aquatic food web. The goal of my dissertation research is to understand better the role heterotrophic bacteria play in carbon cycling in seagrass estuaries. My dissertation research focuses on Florida Bay, a seagrass estuary that has experienced recent changes in carbon source availability, which may have altered ecosystem function. My dissertation research investigates the importance of seagrass, algal and/or cyanobacterial, and allochthonous-derived organic matter to heterotrophic bacteria in Florida Bay and helps establish the carbon base of the estuarine food web. ^ A three tiered approach to the study of heterotrophic bacterial carbon cycling and trophic influences in Florida Bay was used: (1) Spatiotemporal observations of environmental parameters (hydrology, nutrients, extracellular enzymes, and microbial abundance, biomass, and production); (2) Microbial grazing experiments under different levels of top-down and bottom-up influence; and (3) Bulk and compound-specific (bacteria-biomarker fatty acid analysis) stable carbon isotope analysis. ^ In Florida Bay, spatiotemporal patterns in microbial extracellular enzyme (also called ectoenzyme) activities indicate that microorganisms hydrolyzed selectively fractions of the estuarine organic matter pool. The microbial community hydrolyzed organic acids, peptides, and phosphate esters and did not use storage and structural carbohydrates. Organic matter use by heterotrophic bacterioplankton in Florida Bay was co-regulated by bottom-up (resource availability) and top-down (grazer mediated) processes. A bacterial carbon budget based on bacterial, epiphytic, and seagrass production indicates that heterotrophic bacterial carbon cycles are supported primarily through epiphytic production with mixing from seagrass production. Stable carbon isotope analysis of bacteria biomarkers and carbon sources in Florida Bay corroborate the results of the bacterial carbon budget. These results support previous studies of aquatic consumers in Florida Bay, indicating that epiphytic/benthic algal and/or cyanobacterial production with mixing from seagrass-derived organic matter is the carbon base of the seagrass estuarine food web. ^

Employee Tumover: Implications for Hotel Managers

The hotel industry has been experiencing a severe labor shortage in recent years. The need for organizations to attempt to retain current employees has increased as a direct result of this shortage. An area that has not received as much attention in industry literature is to look at what may be the determinants and the predictors of the turnover process. The authors’ discuss the role of specific intentions, reasoned action, and job satisfaction and the implications of these factors for hotel managers.

Influence of Restaurant Reviews Upon Consumers

It is generally believed that restaurant reviews can influence consumers' decisions in choosing a restaurant. A survey administered to a sample of 420 college faculty and staff members suggests that while most restaurant patrons may read reviews, they are not used as the sole selection criterion. Recommendations of friends, the restaurant's current reputation, and perceived value may have greater influence upon the choice than does a re- view. The authors discuss the implications of both favorable and unfavorable reviews.

Reducing uncertainties in estimation of wind effects on tall buildings using aerodynamic wind tunnel tests

Tall buildings are wind-sensitive structures and could experience high wind-induced effects. Aerodynamic boundary layer wind tunnel testing has been the most commonly used method for estimating wind effects on tall buildings. Design wind effects on tall buildings are estimated through analytical processing of the data obtained from aerodynamic wind tunnel tests. Even though it is widely agreed that the data obtained from wind tunnel testing is fairly reliable the post-test analytical procedures are still argued to have remarkable uncertainties. This research work attempted to assess the uncertainties occurring at different stages of the post-test analytical procedures in detail and suggest improved techniques for reducing the uncertainties. Results of the study showed that traditionally used simplifying approximations, particularly in the frequency domain approach, could cause significant uncertainties in estimating aerodynamic wind-induced responses. Based on identified shortcomings, a more accurate dual aerodynamic data analysis framework which works in the frequency and time domains was developed. The comprehensive analysis framework allows estimating modal, resultant and peak values of various wind-induced responses of a tall building more accurately. Estimating design wind effects on tall buildings also requires synthesizing the wind tunnel data with local climatological data of the study site. A novel copula based approach was developed for accurately synthesizing aerodynamic and climatological data up on investigating the causes of significant uncertainties in currently used synthesizing techniques. Improvement of the new approach over the existing techniques was also illustrated with a case study on a 50 story building. At last, a practical dynamic optimization approach was suggested for tuning structural properties of tall buildings towards attaining optimum performance against wind loads with less number of design iterations.

As estações ferroviárias do Triângulo Mineiro e Alto Paranaíba e suas interfaces: história e conservação

The implementation of the railway in Triângulo Mineiro and Alto Paranaíba helped to develop the area and connexion with other states: São Paulo, Goiás and Mato Grosso. The railway used to transport people and goods throughout many train stations in urban and rural areas and some major railroad complexes. There were many factors that led to the decline and abandonment of these properties: governmental policies which were in favour of road transportation and automotive industry, the replacement of the steam locomotive for electric and electric-diesel locomotives, changing part of the railway plan, removal of railways and loss of function of the buildings, extinction of passenger trains, which led the stations to lose its main purpose: people transport. 53% of the stations built inside the study area were demolished and most of them are in rural areas. There are several situations: stations on a precarious conservation state, most of them in the city s rural area, stations being used in urban and rural areas with new uses, stations working with cargo and goods transportation. The stations in Triângulo Mineiro and Alto Paranaíba area in Minas Gerais are the object of this dissertation, wherein the main interest lies on the stations that are in operation, 21 buildings, seeking to verify their conservation state, their agents and role in preserving the train memory. Maps, charts and tables were made for this collection s understanding, having visited the stations that are listed by the cultural heritage and the ones that are in operation with new functions. Field records were made allowing the understanding of these properties in operation. It is observed that only the buildings listing, despite ensuring the non-demolition, does not help on the use and preservation of these stations, because there are some buildings that have this protection level, but are abandoned and in disrepair. The use of these stations by a train company, operating with cargo and goods transportation do not also guarantee the buildings preservation, as they are not treated with any preservation interest, their maintenance are precarious. The using by these companies are various, however, only a few stations have internal spaces dedicated to the railroad memory. Most of the stations did not have preservation projects with architects and specialists participation and the major concern, during maintenance process, is on the building s external part. The stations conservation begins on the local government interest, that preserve these properties, most of them are in urban areas, the major challenge is on their using definition and occupancy, especially in the countryside, wherein the buildings uses must be sustainable, as regards the appreciation and management of this heritage.

Integrated geoarchaeological methods for the determination of site activity areas : A study of a Viking Age house in Reykjavik, Iceland

Acknowledgements The excavation was funded by the City of Reykjavík, and the geoarchaeological research was funded by a SSHRCC Doctoral Fellowship from the government of Canada, an Overseas Research Studentship, the Cambridge Commonwealth Trust, Pelham Roberts and Muriel Onslow Research Studentships from Newnham College, Cambridge, and Canadian Centennial Scholarships from the Canadian High Commission in London. Garðar Guðmundsson took the micromorphology samples, and supervised sampling on site. The bones were counted by Clayton Tinsley, the thin sections were made by Julie Boreham, and Steve Boreham and his team in the Department of Geography, University of Cambridge, provided technical support for all of the bulk geochemical analyses that were conducted by K. Milek, except for ICP–AES, which was conducted by ALS Chemex. Our gratitude is extended to Charles French, Catherine Hills, Peter Jordan and two anonymous reviewers for their support and helpful comments on earlier drafts of this paper, and to Óskar Gísli Sveinbjarnarson for his assistance with the figures.