Upgrade

Distribution by Scientific Domains


Selected Abstracts


Towards Fast Measurement of the Electron Temperature in the SOL of ASDEX Upgrade Using Swept Langmuir Probes

CONTRIBUTIONS TO PLASMA PHYSICS, Issue 9 2010
H.W. Müller
Abstract On ASDEX Upgrade first experiments were made using single probes with a voltage sweep frequency up to 100kHz. Possibilities and limitations using fast swept probes with a standard diagnostic and analysis tools are discussed. A good agreement between the data derived from fast swept single probe characteristics and floating as well as saturation current measurements was found. In a stationary (non ELMing) plasma the data of the fast swept probe are compared to standard slow swept probes (kHz range) showing an improvement of the measurement by faster sweeping. While ELM filaments already could be resolved the access of electron temperature fluctuations in small scale turbulence still has to be improved. Further comparisons are done in ELMy H-mode with combined ball-pen probe/floating potential measurements which can deliver electron temperatures with 25 , s time resolution at reduced spatial resolution compared to pin probes. During ELMs the electron temperatures derived from the ball-pen probe and fast swept single probes agreed (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Ball-Pen Probe Measurements in L-Mode and H-Mode on ASDEX Upgrade

CONTRIBUTIONS TO PLASMA PHYSICS, Issue 9 2010
J. Adamek
Abstract Experimental investigations of the plasma potential, poloidal electric field and electron temperature during L-mode and ELMy H-mode were performed on ASDEX Upgrade by means of a probe head containing four ball-pen probes and four Langmuir probes. This allows to measure simultaneously the floating and plasma potential at the same time which are related by the electron temperature. Thus a combination of ball-pen probes and Langmuir probes offers the possibility to determine the electron temperature directly with high temporal resolution. This novel temperature measurement method is compared to standard techniques. The influence of the electron temperature on the usual calculation of the poloidal electric field from the gradient of the floating potential is determined by a comparison to the poloidal electric field derived from the plasma potential (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Simulating the Role of Intrinsic Carbon Impurities in the Divertor Detachment of ASDEX Upgrade

CONTRIBUTIONS TO PLASMA PHYSICS, Issue 1-3 2008
M. Wischmeier
Abstract As part of a general effort in validating SOL fluid Monte Carlo codes, well diagnosed ohmic discharges have been done in ASDEX Upgrade reaching from the lowest accessible density up to densities at which both targets were at least partially detached. The numerical code B2.5-EIRENE has been used to simulate these experiments with a particular focus on detachment. Whilst it is possible to qualitatively reproduce the general experimental observations when transiting from attached to detached plasmas, the simulations do not reproduce the detachment threshold observed in experiment quantitatively. The strong asymmetry of the ion flux density between the inner and the outer target with increasing density and in particular the vanishing ion flux, defined as full detachment, at the inner target cannot be reproduced. The influence of various parameters such as chemical sputtering yields and the effect of the activation of drift terms on the results is analyzed. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Increase in Ventricular Tachycardia Frequency After Biventricular Implantable Cardioverter Defibrillator Upgrade

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 11 2003
JOSE M. GUERRA M.D.
We report the case of a patient in whom transvenous left ventricular pacing lead placement at the time of a biventricular upgrade led to an exacerbation of clinical monomorphic ventricular tachycardia (MVT). At implant, slow left ventricular pacing repeatedly induced sustained MVT. However, testing of the biventricular pacing showed no MVT inducibility, and the system was implanted. The patient was readmitted due to multiple episodes of the MVT observed at implant. The MVT was controlled with pharmacotherapy, allowing the patient to continue with biventricular pacing. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1245-1247, November 2003) [source]


Upgrade of the CATS sample changer on FIP-BM30A at the ESRF: towards a commercialized standard

JOURNAL OF SYNCHROTRON RADIATION, Issue 1 2009
L. Jacquamet
An upgraded version of the sample changer `CATS' (Cryogenic Automated Transfer System) that was developed on the FIP-BM30A beamline at the ESRF is presented. At present, CATS is installed at SLS (three systems), BESSY (one system), DLS (two systems) and APS (four systems for the LSCAT beamline). It consists mainly of an automated Dewar with an assortment of specific grippers designed to obtain a fast and reliable mounting/dismounting rate without jeopardizing the flexibility of the system. The upgraded system has the ability to manage any sample standard stored in any kind of puck. [source]


Branch-and-Price Methods for Prescribing Profitable Upgrades of High-Technology Products with Stochastic Demands*

DECISION SCIENCES, Issue 1 2004
Purushothaman Damodaran
ABSTRACT This paper develops a model that can be used as a decision support aid, helping manufacturers make profitable decisions in upgrading the features of a family of high-technology products over its life cycle. The model integrates various organizations in the enterprise: product design, marketing, manufacturing, production planning, and supply chain management. Customer demand is assumed random and this uncertainty is addressed using scenario analysis. A branch-and-price (B&P) solution approach is devised to optimize the stochastic problem effectively. Sets of random instances are generated to evaluate the effectiveness of our solution approach in comparison with that of commercial software on the basis of run time. Computational results indicate that our approach outperforms commercial software on all of our test problems and is capable of solving practical problems in reasonable run time. We present several examples to demonstrate how managers can use our models to answer "what if" questions. [source]


The local ETKF and SKEB: Upgrades to the MOGREPS short-range ensemble prediction system

THE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 640 2009
Neill E. Bowler
Abstract The Met Office has been routinely running a short-range global and regional ensemble prediction system (EPS) since the summer of 2005. This article describes a major upgrade to the global ensemble, which affected both the initial condition and model uncertainty perturbations applied in that ensemble. The change to the initial condition perturbations is to allow localization within the ensemble transform Kalman filter (ETKF). This enables better specification of the ensemble spread as a function of location around the globe. The change to the model uncertainty perturbations is the addition of a stochastic kinetic energy backscatter scheme (SKEB). This adds vorticity perturbations to the forecast in order to counteract the damping of small-scale features introduced by the semi-Lagrangian advection scheme. Verification of ensemble forecasts is presented for the global ensemble system. It is shown that the localization of the ETKF gives a distribution of the spread as a function of latitude that better matches the forecast error of the ensemble mean. The SKEB scheme has a substantial effect on the power spectrum of the kinetic energy, and with the scheme a shallowing of the spectral slope is seen in the tail. A k,5/3 slope is seen at wavelengths shorter than 1000 km and this better agrees with the observed spectrum. The local ETKF significantly improves forecasts at all lead times over a number of variables. The SKEB scheme increases the rate of growth of ensemble spread in some variables, and improves forecast skill at short lead times. ©Crown Copyright 2009. Reproduced with the permission of HMSO. Published by John Wiley & Sons Ltd. [source]


Road upgrade in Victoria a filter to the movement of the endangered Squirrel glider (Petaurus norfolcensis): Results of a pilot study

ECOLOGICAL MANAGEMENT & RESTORATION, Issue 3 2006
Rodney Van Der Ree
No abstract is available for this article. [source]


Awarding Entrepreneurship Research: A Presentation of the Global Award

ENTREPRENEURSHIP THEORY AND PRACTICE, Issue 3 2009
Pontus Braunerhjelm
On January 29, 2009, professor Scott A. Shane, Case Western Reserve University (Cleveland, Ohio), became the first recipient of the Global Award for Entrepreneurship Research, an upgrade of the previous award given annually since 1996, and since then firmly established as the leading prize for outstanding research contributions in the area. The objective of this essay is to present the background to and the organizations behind the award; to describe how candidates are nominated, evaluated, and selected; and to give a clear account of the criteria that guide the Prize Committee in their selection of award winners. [source]


Impact of energy efficiency upgrade retrofits on the residential energy consumption in Canada

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 9 2001
Burak Guler
Abstract The impact of various energy efficiency upgrade scenarios on the annual energy consumption of the Canadian housing stock is assessed using the Canadian Residential Energy End-use Model (CREEM). The energy efficiency upgrade scenarios that are considered include major retrofits, such as the improvement of the house envelope by adding insulation, and the replacement of the existing heating system and appliances by higher efficiency units, as well as minor retrofits, such as lighting fixture, thermostat, showerhead and aerator upgrades that reduce energy consumption. The economic feasibility of each upgrade was assessed using the indicator ,energy savings per dollar investment'. The results indicate that the energy savings potential of the retrofits is rather small, resulting in savings of 0,8 per cent of the total energy consumption of the Canadian housing stock. Copyright © 2001 John Wiley & Sons, Ltd. [source]


Distribution-based anomaly detection in 3G mobile networks: from theory to practice

INTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 5 2010
Alessandro D'Alconzo
The design of anomaly detection (AD) methods for network traffic has been intensively investigated by the research community in recent years. However, less attention has been devoted to the issues which eventually arise when deploying such tools in a real operational context. We designed a statistical based change detection algorithm for identifying deviations in distribution time series. The proposed method has been applied to the analysis of a large dataset from an operational 3G mobile network, in the perspective of the adoption of such a tool in production. Our algorithm is designed to cope with the marked non-stationarity and daily/weekly seasonality that characterize the traffic mix in a large public network. Several practical issues emerged during the study, including the need to handle incompleteness of the collected data, the difficulty in drilling down the cause of certain alarms, and the need for human assistance in resetting the algorithm after a persistent change in network configuration (e.g. a capacity upgrade). We report on our practical experience, highlighting the key lessons learned and the hands-on experience gained from such an analysis. Finally, we propose a novel methodology based on semi-synthetic traces for tuning and performance assessment of the proposed AD algorithm. Copyright © 2010 John Wiley & Sons, Ltd. [source]


Successful Catheter Ablation of Two Types of Ventricular Tachycardias Triggered by Cardiac Resynchronization Therapy: A Case Report

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2 2007
PETR PEICHL M.D., Ph.D.
We report a case of a patient with nonischemic dilated cardiomyopathy and implantable cardioverter-defibrillator, in whom an upgrade to biventricular pacing triggered multiple episodes of ventricular tachycardias (VTs) of two morphologies. First VT presented as repetitive nonsustained arrhythmia of the same morphology as isolated ectopic beats, suggesting its focal origin. Second VT was reentrant and was triggered by the former ectopy, leading to a therapy from the device. Electroanatomical mapping of the left ventricle revealed relatively small low voltage area in the left ventricular outflow tract and identified both an arrhythmogenic focus as well as critical isthmus for reentrant VT. Radiofrequency catheter ablation successfully abolished both VTs. After the procedure, biventricular pacing was continued without any recurrences during a period of 24 months. The report emphasizes the role of catheter ablation in management of VTs triggered by cardiac resynchronization therapy. [source]


Increase in Ventricular Tachycardia Frequency After Biventricular Implantable Cardioverter Defibrillator Upgrade

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 11 2003
JOSE M. GUERRA M.D.
We report the case of a patient in whom transvenous left ventricular pacing lead placement at the time of a biventricular upgrade led to an exacerbation of clinical monomorphic ventricular tachycardia (MVT). At implant, slow left ventricular pacing repeatedly induced sustained MVT. However, testing of the biventricular pacing showed no MVT inducibility, and the system was implanted. The patient was readmitted due to multiple episodes of the MVT observed at implant. The MVT was controlled with pharmacotherapy, allowing the patient to continue with biventricular pacing. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1245-1247, November 2003) [source]


Assessment of "grading" with Ki-67 and c-kit immunohistochemical expressions may be a helpful tool in management of patients with flat epithelial atypia (FEA) and columnar cell lesions (CCLs) on core breast biopsy

JOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2009
Rosa M. Tomasino
It is essential to reach a better understanding of "flat epithelial atypia/columnar cell lesions" (FEA/CCLs) in breast core biopsies. Our aim was to explore their biological nature, in order to predict the likelihood of an upgrade to carcinoma. "Cytological grading" has been specially focused, in view of its possible utility in the choice of management. One hundred thirty of a total of 900 cases core needle (CN)/vacuum-assisted biopsies (VABs), with diagnoses of "hyperplasia" and "atypia" were retrospectively re-evaluated. Pathological findings of further excision biopsies (FEBs) performed in 40/75 patients with follow-up were compared with the previous diagnoses. In all cases, both Ki-67 and c-kit immunoreactivities were explored and compared with both normal breast tissues and subsequently documented cancers, with special reference to the hyperplastic FEA/CCLs, with "mild" atypia (FEA/CCHAm). Sixteen cases were re-diagnosed as "usual ductal hyperplasia" (UDH), 60 as "columnar cell hyperplasia" (CCH), and 54 as FEA/CCHA, 30 of which FEA/CCHAm and 24 FEA/CCHAh (with high atypia). Significantly, the Ki-67 index proved to be on the increase and c-kit expression on the decrease in FEA/CCHA lesions, mainly in the FEA/CCHAh group and in the subsequently observed cancers, compared with either benign tissues or the FEA/CCH cases. It was also significant that most of the carcinomas were found in FEBs within the FEA/CCHAh group. In this study cytological grading, together with Ki-67 and c-kit indices, proved to be helpful in FEA/CCLs evaluation. With regard to FEA/CCHAm lesions, an adequate surveillance appears to be a more appropriate management tool than FEB, as a result of their biological nature and behavior. J. Cell. Physiol. 221: 343,349, 2009. © 2009 Wiley-Liss, Inc. [source]


Reactions leading to the formation and breakdown of stilpnomelane in the Otago Schist, New Zealand

JOURNAL OF METAMORPHIC GEOLOGY, Issue 4 2000
G. Li
Semi-pelitic rocks ranging in grade from the prehnite,pumpellyite to the greenschist facies from south-eastern Otago, New Zealand, have been investigated in order to evaluate the reactions leading to formation and breakdown of stilpnomelane. Detrital grains of mica and chlorite along with fine-grained authigenic illite and chlorite occur in lower-grade rocks with compactional fabric parallel to bedding. At higher grades, detrital grains have undergone dissolution, and metamorphic phyllosilicates have crystallized with preferred orientation (sub)parallel to bedding, leading to slaty cleavage. Stilpnomelane is found in metapelites of the pumpellyite,actinolite facies and the chlorite zone of the greenschist facies, but only rarely in the biotite zone of the greenschist facies. Illite or phengite is ubiquitous, whereas chlorite occurs only rarely with stilpnomelane upgrade of the pumpellyite-out isograd. Chemical and textural relationships suggest that stilpnomelane formed from chlorite, phengite, quartz, K-feldspar and iron oxides. Stilpnomelane was produced by grain-boundary replacement of chlorite and by precipitation from solution, overprinting earlier textures. Some relict 14 Å chlorite layers are observed by TEM to be in the process of transforming to 12 Å stilpnomelane layers. The AEM analyses show that Fe is strongly partitioned over Mg into stilpnomelane relative to chlorite (KD,2.5) and into chlorite relative to phengite (KD,1.9). Modified A,FM diagrams, projected from the measured phengite composition rather than from ideal KAl3Si3O10(OH)2, are used to elucidate reactions among chlorite, stilpnomelane, phengite and biotite. In addition to pressure, temperature and bulk rock composition, the stilpnomelane-in isograd is controlled by variations in K, Fe3+/Fe2+, O/OH and H2O contents, and the locus of the isograd is expected to vary in rocks of different oxidation states and permeabilities. Biotite, quartz and less phengitic muscovite form from stilpnomelane, chlorite and phengite in the biotite zone. Projection of bulk rock compositions from phengite, NaAlO2, SiO2 and H2O reveals that they lie close to the polyhedra defined by the A,FM minerals and albite. Other extended A,FM diagrams, such as one projected from phengite, NaAlO2, CaAl2O4, SiO2 and H2O, may prove useful in the evaluation of other low-grade assemblages. [source]


The Impact of Underage Drinking Laws on Alcohol-Related Fatal Crashes of Young Drivers

ALCOHOLISM, Issue 7 2009
James C. Fell
Background:, This study used a pre- to post-design to evaluate the influence on drinking-and-driving fatal crashes of 6 laws directed at youth aged 20 and younger and 4 laws targeting all drivers. Methods:, Data on the laws were drawn from the Alcohol Policy Information System data set (1998 to 2005), the Digests of State Alcohol Highway Safety Related Legislation (1983 to 2006), and the Westlaw database. The Fatality Analysis Reporting System data set (1982 to 2004) was used to assess the ratio of drinking to nondrinking drivers involved in fatal crashes [fatal crash incidence ratio (CIR)]. The data were analyzed using structural equation modeling techniques. Results:, Significant decreases in the underage fatal CIR were associated with presence of 4 of the laws targeting youth (possession, purchase, use and lose, and zero tolerance) and 3 of the laws targeting all drivers (0.08 blood alcohol concentration illegal per se law, secondary or upgrade to a primary seat belt law, and an administrative license revocation law). Beer consumption was associated with a significant increase in the underage fatal CIR. The direct effects of laws targeting drivers of all ages on adult drinking drivers aged 26 and older were similar but of a smaller magnitude compared to the findings for those aged 20 and younger. It is estimated that the 2 core underage drinking laws (purchase and possession) and the zero tolerance law are currently saving an estimated 732 lives per year controlling for other exposure factors. If all states adopted use and lose laws, an additional 165 lives could be saved annually. Conclusions:, These results provide substantial support for the effectiveness of under age 21 drinking laws with 4 of the 6 laws examined having significant associations with reductions in underage drinking-and-driving fatal crashes. These findings point to the importance of key underage drinking and traffic safety laws in efforts to reduce underage drinking-driver crashes. [source]


Angle-resolved photoemission spectroscopy and imaging with a submicrometre probe at the SPECTROMICROSCOPY-3.2L beamline of Elettra

JOURNAL OF SYNCHROTRON RADIATION, Issue 4 2010
Pavel Dudin
The extensive upgrade of the experimental end-station of the SPECTROMICROSCOPY-3.2L beamline at Elettra synchrotron light source is reported. After the upgrade, angle-resolved photoemission spectroscopy from a submicrometre spot and scanning microscopy images monitoring the photoelectron signal inside selected acquisition angle and energy windows can be performed. As a test case, angle-resolved photoemission spectroscopy from single flakes of highly oriented pyrolitic graphite and imaging of the flakes with image contrast owing to rotation of the band dispersion of different flakes are presented. [source]


Use of Triple-Site Ventricular Pacing in a Patient with Severe Congestive Heart Failure and Atrial Fibrillation

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 5 2009
FAIZEL OSMAN M.D.
Cardiac resynchronization therapy (CRT) has become an accepted treatment for selected patients with drug-resistant heart failure. Data for patients in atrial fibrillation (AF) remains limited but suggests benefit in these patients too. We report the case of an 82-year-old patient with heart failure, VVIR permanent pacemaker, and permanent AF who had an upgrade to triple-site CRT implantation with good clinical response. Triple-site ventricular pacing may enhance the chance of response and LV reverse remodeling and should be considered in AF patients undergoing CRT implantation. [source]


Laser Lead Extraction: Predictors of Success and Complications

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2 2007
JEAN-FRANÇOIS ROUX M.D.
Background: Paralleling the rise in pacemaker and defibrillator implantations, lead extraction procedures are increasingly required. Concerns regarding failure and complications remain. Methods and Results: A total of 200 lead extraction procudures were performed at the Montreal Heart Institute between September 2000 and August 2005. In 23 patients, all leads were removed by traction with a locking stylet. A total of 270 leads were extracted using a laser sheath system (Spectranectics, Colorado Springs, CO, USA) in 177 procedures involving 175 patients (74% male), age 62±16 years. Procedural indications were: infection 88 (50%), dysfunction 54 (30%), upgrade 21 (12%), and other 14 (8%). Overall, 241 leads (89%) were successfully extracted, 7 (3%) were partially extracted (,4 cm retained), and 22 (8%) were non-extractable. In multivariate analyses, predictors of failed extraction were longer time from implant (OR 1.16 per year, P=0.0001) and history of hypertension (OR 5.2, P=0.0023). Acute complications occurred in 14 of 177 procedures (7.9%): 8 (4.5%) minor and 6 (3.4%) major, with one death. In multivariate analyses, the only predictor of acute complications was laser lead extraction from both right and left sides during the same procedure (OR 9.4, P = 0.0119). In addition, 3 of 10 patients with failed or partially extracted infected systems eventually required open chest explantation because of endocarditis. Conclusion: Most leads not amenable to manual traction may be successfully extracted by a percutaneous laser sheath system. While most complications are minor, major complications including death may occur. Older leads are at higher risk for failed extraction. Endocarditis may ensue if infected leads are incompletely removed. [source]


Variability in Implantable Cardioverter Defibrillator Pulse Generator Longevity Between Manufacturers

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1p1 2003
PATRICK T. ELLINOR
ELLINOR, P.T., et al.: Variability in Implantable Cardioverter Defibrillator Pulse Generator Longevity Between Manufacturers.ICDs are used frequently to treat malignant ventricular arrhythmias. Despite the expanding role of these devices, little is known about the manufacturer variability in the performance of ICD generators. The purpose of this study is to explore the indications for ICD pulse generator replacement and to examine performance differences between the three major manufacturers of ICDs in the United States. The authors performed a retrospective review of ICD pulse generators that were implanted and replaced at Massachusetts General Hospital between February 1998 and March 2002. During the study period, 50 (7%) of the 707 devices in the study cohort were replaced. The most common indication for pulse generator replacement was related to battery performance followed by device recall, upgrade to a dual chamber device, and pulse generator malfunction. After exclusion of the recalled devices, a significantly higher number of pulse generators manufactured by St. Jude Medical (14/229) required replacement for battery depletion or prolonged charge times during the study period compared with devices from Guidant (2/220) or Medtronic (0/273),P = 0.003andP < 0.0001, respectively. This difference was attributable to reduced longevity in the Angstrom series of defibrillators. (PACE 2003; 26[Pt. I]:71,75) [source]


Addition of a Left Ventricular Lead to Conventional Pacing Systems in Patients with Congestive Heart Failure: Feasibility, Safety, and Early Results in 60 Consecutive Patients

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 8 2002
CINDY M. BAKER
BAKER, C.M., et al.: Addition of a Left Ventricular Lead to Conventional Pacing Systems in Patients with Congestive Heart Failure: Feasibility, Safety, and Early Results in 60 Consecutive Patients. Left bundle branch block worsens congestive heart failure (CHF) in patients with LV dysfunction. Asynchronous LV activation produced by RV apical pacing leads to paradoxical septal motion and inefficient ventricular contraction. Recent studies show improvement in LV function and patient symptoms with biventricular pacing in patients with CHF. The aim of this study was to determine the feasibility, safety, acute efficacy, and early effect on symptoms of the upgrade of a chronically implanted RV pacing system to a biventricular system. Sixty patients with NYHA Class III and IV underwent the upgrade procedure using commercially available leads and adapters. The procedure succeeded in 54 (90%) of 60 patients. Acute LV stimulation thresholds obtained from leads placed along the lateral LV wall via the coronary sinus compare favorably to those reported in current biventricular pacing trials. The complication rate was low (5/60, 8.3%): lead dislodgement (n = 1), pocket hematoma (n = 1), and wound infections (n = 3). During 18 months of follow-up (16.7%) of 60 patients died. Two patients that died failed the initial upgrade attempt. At 3-month follow-up, quality of life scores improved 31 ± 28 points (n = 29), P < 0.0001). NYHA Class improved from 3.4 ± 0.5 to 2.4 ± 0.7 (P = < 0.0001) and ejection fraction increased from 0.23 ± 0.8 to 0.29 ± 0.11 (P = 0.0003). Modification of RV pacing to a biventricular system using commercially available leads and adapters can be performed effectively and safely. The early results of this study suggest patients may benefit from this procedure with improved functional status and quality of life. [source]


The local ETKF and SKEB: Upgrades to the MOGREPS short-range ensemble prediction system

THE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 640 2009
Neill E. Bowler
Abstract The Met Office has been routinely running a short-range global and regional ensemble prediction system (EPS) since the summer of 2005. This article describes a major upgrade to the global ensemble, which affected both the initial condition and model uncertainty perturbations applied in that ensemble. The change to the initial condition perturbations is to allow localization within the ensemble transform Kalman filter (ETKF). This enables better specification of the ensemble spread as a function of location around the globe. The change to the model uncertainty perturbations is the addition of a stochastic kinetic energy backscatter scheme (SKEB). This adds vorticity perturbations to the forecast in order to counteract the damping of small-scale features introduced by the semi-Lagrangian advection scheme. Verification of ensemble forecasts is presented for the global ensemble system. It is shown that the localization of the ETKF gives a distribution of the spread as a function of latitude that better matches the forecast error of the ensemble mean. The SKEB scheme has a substantial effect on the power spectrum of the kinetic energy, and with the scheme a shallowing of the spectral slope is seen in the tail. A k,5/3 slope is seen at wavelengths shorter than 1000 km and this better agrees with the observed spectrum. The local ETKF significantly improves forecasts at all lead times over a number of variables. The SKEB scheme increases the rate of growth of ensemble spread in some variables, and improves forecast skill at short lead times. ©Crown Copyright 2009. Reproduced with the permission of HMSO. Published by John Wiley & Sons Ltd. [source]


Intercomparison of line-parameter spectroscopic databases using downwelling spectral radiance

THE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue S3 2007
F. Esposito
Abstract Ground-based Fourier Transform Spectrometer observations in the infrared, acquired during the Italian phase of the EAQUATE campaign, have been considered in this study and compared to calculations. Synthetic spectral radiances have been obtained using the 2000 and 2004 releases and the 2006 upgrade of HITRAN spectral databases. It has been found that synthetic radiance computations fit the data quite well, even though the goodness of the fit depends on the spectral database. Differences in the spectral residual behaviour appear to be mostly localized in the long-wave side of the Earth emission spectrum, i.e. in the spectral region 520,610 cm,1, which is dominated by the water vapour rotational absorption band. In this range, computation performed with the latest updates provides almost the same results as those of HITRAN2000, while HITRAN2004 shows a mixed behaviour,better than the first two in a large region of the spectral range, but worse at very few specific wave numbers. Overall, HITRAN2006 yields the highest consistency with the observations. No sensitive differences appear at higher wave numbers. Copyright © 2007 Royal Meteorological Society [source]


A Comparative Analysis of Transarterial Downstaging for Hepatocellular Carcinoma: Chemoembolization Versus Radioembolization

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 8 2009
R. J. Lewandowski
Chemoembolization and other ablative therapies are routinely utilized in downstaging from United Network for Organ Sharing (UNOS) T3 to T2, thus potentially making patients transplant candidates under the UNOS model for end-stage liver disease (MELD) upgrade for hepatocellular carcinoma (HCC). This study was undertaken to compare the downstaging efficacy of transarterial chemoembolization (TACE) versus transarterial radioembolization. Eighty-six patients were treated with either TACE (n = 43) or transarterial radioembolization with Yttrium-90 microspheres (TARE-Y90; n = 43). Median tumor size was similar (TACE: 5.7 cm, TARE-Y90: 5.6 cm). Partial response rates favored TARE-Y90 versus TACE (61% vs. 37%). Downstaging to UNOS T2 was achieved in 31% of TACE and 58% of TARE-Y90 patients. Time to progression according to UNOS criteria was similar for both groups (18.2 months for TACE vs. 33.3 months for TARE-Y90, p = 0.098). Event-free survival was significantly greater for TARE-Y90 than TACE (17.7 vs. 7.1 months, p = 0.0017). Overall survival favored TARE-Y90 compared to TACE (censored 35.7/18.7 months; p = 0.18; uncensored 41.6/19.2 months; p = 0.008). In conclusion, TARE-Y90 appears to outperform TACE for downstaging HCC from UNOS T3 to T2. [source]


Separation and Mineralogical Analysis of Bayer Red Mud

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5-6 2002
T. Picaro
This paper describes preliminary work to assess the potential for recovering valuable components from Queensland Alumina Limited (QAL) red mud by physical beneficiation. Upgrading of Weipa bauxites residue was trialed using a 50 mm hydrocyclone and a Mozley Multigravity Separator (MGS) to recover desilication product (DSP) and TiO2 fractions. The mineralogy of the original red muh and the various sub-fractions produced was studied by chemical assay, selective leaching, XRD and SEM techniques. DSP is present in QAL red mud in two forms: (i) as balls in the size range from 0.8 to 10 ,m that appear to be liberated; and (ii) as finely grained DSP intermixed with the other minerals. The hydrocycloning tests produced a DSP rich (39.5 wt%) fraction at 89% recovery from a feed containing 31.9 wt.% DSP. This represents an upgrade (enrichment) of 1.24 times. These results suggest that the greatest DSP enrichment will be achieved by targeting the 0.8 to 10 ,m DSP balls. The richest TiO2 fraction produced varied from 20 to 36 wt.% TiO2 from a feed value of 7 wt.% at a recovery of 7.5%. Mineralogical examination showed that most of the TiO2 in this fraction was as liberated particles in the size range 8 to 20 ,m. Most of the TiO2 particles in the other fractions were not fully liberated from mainly iron minerals. The present work indicates that it is possible to further upgrade DSP fractions by investigating finer particle separation techniques, e.g. smaller, 25 mm and 10 mm, hydrocyclones. [source]


Stereotactic vacuum-assisted breast biopsy in 2874 patients

CANCER, Issue 2 2004
A multicenter study
Abstract BACKGROUND Vacuum-assisted breast biopsy (VAB) can replace surgical biopsy for the diagnosis of breast carcinoma. The authors evaluated the accuracy and clinical utility of VAB in a multicenter setting using a strict quality assurance protocol. METHODS In the current study, VABs were performed successfully for 2874 patients at 5 sites. Benign lesions were verified by follow-up. Surgery was recommended for malignant and borderline lesions. VAB was performed on patients with lesions rated as highly suspicious (6%), intermediate to suspicious (85%), or probably benign (9%). Fifty-eight percent of the lesions were < 10 mm and 70% had microcalcifications. RESULTS The authors identified 7% of patients with invasive carcinomas, 15% with ductal carcinomas in situ (DCIS), 5% with atypical ductal hyperplasias (ADH), and 0.6% with lobular carcinomas in situ. The results of the VAB necessitated an upgrade of 24% of patients with ADH to DCIS or DCIS and invasive carcinoma. Twelve percent of patients with DCIS proved to have invasive carcinoma. Seventy-three percent of the patients had benign lesions. Only 1 false-negative result was encountered (negative predictive value, 99.95%). Minor side effects were reported to occur in 1.4% of patients and 0.1% of patients required a subsequent intervention. Scarring relevant for mammography was rare among patients (i.e., 0.3% of patients had relevant scarring). CONCLUSIONS Quality-assured VAB was found to be highly reliable. VAB effectively identified patients with benign lesions and assisted therapeutic decisions. Most important, only a single case of malignancy was missed. A close interdisciplinary approach assured optimal results. Cancer 2004;100:245,51. © 2003 American Cancer Society. [source]


A new approach to long QT syndrome mutation detection by Sequenom MassARRAY® system

ELECTROPHORESIS, Issue 10 2010
Catarina Allegue
Abstract Congenital long QT syndrome is an inherited cardiac disorder characterized by a prolonged QT interval and polymorphic ventricular arrhythmias that could result in recurrent syncope, seizures or sudden death as the most dramatic event. Until now QT interval mutations have been described in 12 genes, where the majority of mutations reside in three genes KCNQ1, KCNH2, and SCN5A. Diagnosis and prognosis are directly related with the gene and mutation involved. We have developed a diagnostic approach for long QT syndrome and Brugada syndrome based on published mutations and Sequenom MassArray® system. Three diagnostic tests have been developed, oriented to each of the three most prevalent genes in the long QT syndrome. A total of 433 mutations are analyzed in 38 multiplex reactions, allowing their detection in about 48,h. Tests were validated on 502 samples from individuals with different clinical conditions and family history. The average call rates obtained for each of the tests were 93, 83, and 73% in KCNQ1, KCNH2, and SCNA, respectively. Sequenom MassARRAY mutation detection is a reliable, highly flexible, and cost-efficient alternative to conventional methods for genetic testing in long QT syndrome and Brugada syndrome, facilitating flexible upgrades of the version of the test presented here with the inclusion of new mutations. [source]


Ratings Changes, Ratings Levels, and the Predictive Value of Analysts' Recommendations

FINANCIAL MANAGEMENT, Issue 2 2010
Brad M. Barber
We show that abnormal returns to analysts' recommendations stem from both the ratings levels assigned and the changes in those ratings. Conditional on the ratings change, buy and strong buy recommendations have greater returns than do holds, sells, and strong sells. Conditional on the ratings level, upgrades earn the highest returns and downgrades the lowest. We also find that both ratings levels and changes predict future unexpected earnings and the associated market reaction. Our results imply that 1) investment returns may be enhanced by conditioning on both recommendation levels and changes; 2) the predictive power of analysts' recommendations reflects, at least partially, analysts' ability to generate valuable private information; and 3) some inconsistency exists between analysts' ratings and the formal ratings definitions issued by securities firms. [source]


Impact of energy efficiency upgrade retrofits on the residential energy consumption in Canada

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 9 2001
Burak Guler
Abstract The impact of various energy efficiency upgrade scenarios on the annual energy consumption of the Canadian housing stock is assessed using the Canadian Residential Energy End-use Model (CREEM). The energy efficiency upgrade scenarios that are considered include major retrofits, such as the improvement of the house envelope by adding insulation, and the replacement of the existing heating system and appliances by higher efficiency units, as well as minor retrofits, such as lighting fixture, thermostat, showerhead and aerator upgrades that reduce energy consumption. The economic feasibility of each upgrade was assessed using the indicator ,energy savings per dollar investment'. The results indicate that the energy savings potential of the retrofits is rather small, resulting in savings of 0,8 per cent of the total energy consumption of the Canadian housing stock. Copyright © 2001 John Wiley & Sons, Ltd. [source]


Networking lessons in delivering ,Software as a Service',Part II

INTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 6 2002
David Greschler
In part I of this paper, we described the origins and evolution of Software as a Service (SaaS) and its value proposition to Corporate IT, Service Providers, Independent Software Vendors and End Users. SaaS is a model in which software applications are deployed, managed, updated and supported on demand,like a utility,and are served to users centrally using servers that are internal or external to the enterprise. Applications are no longer installed locally on a user's desktop PC; instead, upgrades, licensing and version control, metering, support and provisioning are all managed at the server level. In part we examine the lessons learned in researching, building and running an SaaS service. Copyright © 2002 John Wiley & Sons, Ltd. [source]