885 resultados para allocation procedure
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The CHaracterizing ExOPlanet Satellite (CHEOPS) is an ESA Small Mission whose launch is planned for the end of 2017. It is a Ritchey-Chretien telescope with a 320 mm aperture providing a FoV of 0.32 degrees, which will target nearby bright stars already known to host planets, and measure, through ultrahigh precision photometry, the radius of exo-planets, allowing to determine their composition. This paper will present the details of the AIV plan for a demonstration model of the CHEOPS Telescope with equivalent structure but different CTEs. Alignment procedures, needed GSEs and devised verification tests will be described and a path for the AIV of the flight model, which will take place at industries premises, will be sketched. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).
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The OPERA experiment, designed to perform the first observation of νμ→ντ oscillations in appearance mode through the detection of the τ leptons produced in ντ charged current interactions, has collected data from 2008 to 2012. In the present paper, the procedure developed to detect τ particle decays, occurring over distances of the order of 1 mm from the neutrino interaction point, is described in detail. The results of its application to the search for charmed hadrons are then presented as a validation of the methods for ντ appearance detection.
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After the general morbidity reduction at the beginning of the century and the routine use of prophylactic antibiotics, a hysterectomy was generously, sometimes to generously indicated in the middle of the 20th century. This might be one of the major reasons why the procedure got a bad reputation. Furthermore, in the last decade, several new treatments for benign uterine pathologies have been developed which can be proposed to the patients instead of performing a hysterectomy. Therefore, the question might be asked, if nowadays there are still some indications for a hysterectomy or if the procedure is obsolete.
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BACKGROUND/AIMS Several countries are working to adapt clinical trial regulations to align the approval process to the level of risk for trial participants. The optimal framework to categorize clinical trials according to risk remains unclear, however. Switzerland is the first European country to adopt a risk-based categorization procedure in January 2014. We assessed how accurately and consistently clinical trials are categorized using two different approaches: an approach using criteria set forth in the new law (concept) or an intuitive approach (ad hoc). METHODS This was a randomized controlled trial with a method-comparison study nested in each arm. We used clinical trial protocols from eight Swiss ethics committees approved between 2010 and 2011. Protocols were randomly assigned to be categorized in one of three risk categories using the concept or the ad hoc approach. Each protocol was independently categorized by the trial's sponsor, a group of experts and the approving ethics committee. The primary outcome was the difference in categorization agreement between the expert group and sponsors across arms. Linear weighted kappa was used to quantify agreements, with the difference between kappas being the primary effect measure. RESULTS We included 142 of 231 protocols in the final analysis (concept = 78; ad hoc = 64). Raw agreement between the expert group and sponsors was 0.74 in the concept and 0.78 in the ad hoc arm. Chance-corrected agreement was higher in the ad hoc (kappa: 0.34 (95% confidence interval = 0.10-0.58)) than in the concept arm (0.27 (0.06-0.50)), but the difference was not significant (p = 0.67). LIMITATIONS The main limitation was the large number of protocols excluded from the analysis mostly because they did not fit with the clinical trial definition of the new law. CONCLUSION A structured risk categorization approach was not better than an ad hoc approach. Laws introducing risk-based approaches should provide guidelines, examples and templates to ensure correct application.
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Auxin (IAA) is an important regulator of plant development and root differentiation. Although recent studies indicate that salicylic acid (SA) may also be important in this context by interfering with IAA signaling, comparatively little is known about its impact on the plant’s physiology, metabolism, and growth characteristics. Using carbon-11, a short-lived radioisotope (t 1/2 = 20.4 min) administered as 11CO2 to maize plants (B73), we measured changes in these functions using SA and IAA treatments. IAA application decreased total root biomass, though it increased lateral root growth at the expense of primary root elongation. IAA-mediated inhibition of root growth was correlated with decreased 11CO2 fixation, photosystem II (PSII) efficiency, and total leaf carbon export of 11C-photoassimilates and their allocation belowground. Furthermore, IAA application increased leaf starch content. On the other hand, SA application increased total root biomass, 11CO2 fixation, PSII efficiency, and leaf carbon export of 11C-photoassimilates, but it decreased leaf starch content. IAA and SA induction patterns were also examined after root-herbivore attack by Diabrotica virgifera to place possible hormone crosstalk into a realistic environmental context. We found that 4 days after infestation, IAA was induced in the midzone and root tip, whereas SA was induced only in the upper proximal zone of damaged roots. We conclude that antagonistic crosstalk exists between IAA and SA which can affect the development of maize plants, particularly through alteration of the root system’s architecture, and we propose that the integration of both signals may shape the plant’s response to environmental stress.
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OBJECTIVE To determine if adequacy of randomisation and allocation concealment is associated with changes in effect sizes (ES) when comparing physical therapy (PT) trials with and without these methodological characteristics. DESIGN Meta-epidemiological study. PARTICIPANTS A random sample of randomised controlled trials (RCTs) included in meta-analyses in the PT discipline were identified. INTERVENTION Data extraction including assessments of random sequence generation and allocation concealment was conducted independently by two reviewers. To determine the association between sequence generation, and allocation concealment and ES, a two-level analysis was conducted using a meta-meta-analytic approach. PRIMARY AND SECONDARY OUTCOME MEASURES association between random sequence generation and allocation concealment and ES in PT trials. RESULTS 393 trials included in 43 meta-analyses, analysing 44 622 patients contributed to this study. Adequate random sequence generation and appropriate allocation concealment were accomplished in only 39.7% and 11.5% of PT trials, respectively. Although trials with inappropriate allocation concealment tended to have an overestimate treatment effect when compared with trials with adequate concealment of allocation, the difference was non-statistically significant (ES=0.12; 95% CI -0.06 to 0.30). When pooling our results with those of Nuesch et al, we obtained a pooled statistically significant value (ES=0.14; 95% CI 0.02 to 0.26). There was no difference in ES in trials with appropriate or inappropriate random sequence generation (ES=0.02; 95% CI -0.12 to 0.15). CONCLUSIONS Our results suggest that when evaluating risk of bias of primary RCTs in PT area, systematic reviewers and clinicians implementing research into practice should pay attention to these biases since they could exaggerate treatment effects. Systematic reviewers should perform sensitivity analysis including trials with low risk of bias in these domains as primary analysis and/or in combination with less restrictive analyses. Authors and editors should make sure that allocation concealment and random sequence generation are properly reported in trial reports.
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Various software packages for project management include a procedure for resource-constrained scheduling. In several packages, the user can influence this procedure by selecting a priority rule. However, the resource-allocation methods that are implemented in the procedures are proprietary information; therefore, the question of how the priority-rule selection impacts the performance of the procedures arises. We experimentally evaluate the resource-allocation methods of eight recent software packages using the 600 instances of the PSPLIB J120 test set. The results of our analysis indicate that applying the default rule tends to outperform a randomly selected rule, whereas applying two randomly selected rules tends to outperform the default rule. Applying a small set of more than two rules further improves the project durations considerably. However, a large number of rules must be applied to obtain the best possible project durations.
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BACKGROUND AND AIMS The Barcelona Clinic Liver Cancer (BCLC) staging system is the algorithm most widely used to manage patients with hepatocellular carcinoma (HCC). We aimed to investigate the extent to which the BCLC recommendations effectively guide clinical practice and assess the reasons for any deviation from the recommendations. MATERIAL AND METHODS The first-line treatments assigned to patients included in the prospective Bern HCC cohort were analyzed. RESULTS Among 223 patients included in the cohort, 116 were not treated according to the BCLC algorithm. Eighty percent of the patients in BCLC stage 0 (very early HCC) and 60% of the patients in BCLC stage A (early HCC) received recommended curative treatment. Only 29% of the BCLC stage B patients (intermediate HCC) and 33% of the BCLC stage C patients (advanced HCC) were treated according to the algorithm. Eighty-nine percent of the BCLC stage D patients (terminal HCC) were treated with best supportive care, as recommended. In 98 patients (44%) the performance status was disregarded in the stage assignment. CONCLUSION The management of HCC in clinical practice frequently deviates from the BCLC recommendations. Most of the curative therapy options, which have well-defined selection criteria, were allocated according to the recommendations, while the majority of the palliative therapy options were assigned to patients with tumor stages not aligned with the recommendations. The only parameter which is subjective in the algorithm, the performance status, is also the least respected.
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INTRODUCTION Inhaled drugs can only be effective if they reach the middle and small airways. This study introduces a system that combines a trans-nasal application of aerosols with noninvasive pressure support ventilation. METHODS In a pilot study, 7 COPD patients with GOLD stages II and III inhaled a radiolabeled marker dissolved in water via a trans-nasal route. The mean aerosol particle size was 5.5 µm. Each patient took part in two inhalation sessions that included two application methods and were at least 70 hours apart. During the first session ("passive method"), the patient inhaled the aerosol through an open tube system. The second session ("active method") included pressure support ventilation during the inhalation process. A gamma camera and planar scintigraphy was used to determine the distribution of aerosol particles in the patient's body and lung. RESULTS The pressure supported inhalation ("active method") results in an increased aerosol lung deposition compared to the passive method. Above all, we could demonstrate deposition in the lung periphery with relatively large aerosol particles (5.5 µm). DISCUSSION The results prove that the combination of trans-nasal inhalation with noninvasive pressure support ventilation leads to significantly increased particle deposition in the lung.
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BACKGROUND Giant cell arteritis is an immune-mediated disease of medium and large-sized arteries that affects mostly people older than 50 years of age. Treatment with glucocorticoids is the gold-standard and prevents severe vascular complications but is associated with substantial morbidity and mortality. Tocilizumab, a humanised monoclonal antibody against the interleukin-6 receptor, has been associated with rapid induction and maintenance of remission in patients with giant cell arteritis. We therefore aimed to study the efficacy and safety of tocilizumab in the first randomised clinical trial in patients with newly diagnosed or recurrent giant cell arteritis. METHODS In this single centre, phase 2, randomised, double-blind, placebo-controlled trial, we recruited patients aged 50 years and older from University Hospital Bern, Switzerland, who met the 1990 American College of Rheumatology criteria for giant cell arteritis. Patients with new-onset or relapsing disease were randomly assigned (2:1) to receive either tocilizumab (8 mg/kg) or placebo intravenously. 13 infusions were given in 4 week intervals until week 52. Both groups received oral prednisolone, starting at 1 mg/kg per day and tapered down to 0 mg according to a standard reduction scheme defined in the study protocol. Allocation to treatment groups was done using a central computerised randomisation procedure with a permuted block design and a block size of three, and concealed using central randomisation generated by the clinical trials unit. Patients, investigators, and study personnel were masked to treatment assignment. The primary outcome was the proportion of patients who achieved complete remission of disease at a prednisolone dose of 0·1 mg/kg per day at week 12. All analyses were intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01450137. RESULTS Between March 3, 2012, and Sept 9, 2014, 20 patients were randomly assigned to receive tocilizumab and prednisolone, and ten patients to receive placebo and glucocorticoid; 16 (80%) and seven (70%) patients, respectively, had new-onset giant cell arteritis. 17 (85%) of 20 patients given tocilizumab and four (40%) of ten patients given placebo reached complete remission by week 12 (risk difference 45%, 95% CI 11-79; p=0·0301). Relapse-free survival was achieved in 17 (85%) patients in the tocilizumab group and two (20%) in the placebo group by week 52 (risk difference 65%, 95% CI 36-94; p=0·0010). The mean survival-time difference to stop glucocorticoids was 12 weeks in favour of tocilizumab (95% CI 7-17; p<0·0001), leading to a cumulative prednisolone dose of 43 mg/kg in the tocilizumab group versus 110 mg/kg in the placebo group (p=0·0005) after 52 weeks. Seven (35%) patients in the tocilizumab group and five (50%) in the placebo group had serious adverse events. INTERPRETATION Our findings show, for the first time in a trial setting, the efficacy of tocilizumab in the induction and maintenance of remission in patients with giant cell arteritis. FUNDING Roche and the University of Bern.
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This study attempts to analyze the underlying factors and motives influencing the allocation of discretionary state expenditures. The fact that some cities receive more money than other cities begs the question of what accounts for this variation. After framing the provision of state money within the theoretical framework of political patronage, a case study of Governor Rowland’s tenure in office and the accompanying expenditures to Connecticut’s 17 largest cities from 1995 to 2004 was conducted to evaluate whether a disproportionate amount of money was given to Rowland’s hometown of Waterbury, Connecticut. Besides employing a statistical analysis that determined that cities with similar characteristics received different amounts of money, interviewing was conducted to identify reasons for such variation. The results indicate that Waterbury received a greater amount of money than was predicted based on the city’s economic and demographic characteristics, and that non-objective and biased factors such as favoritism, the need to reward political support, or the desire to increase political loyalty sometimes take precedence over more objective factors.
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The Data Envelopment Analysis (DEA) efficiency score obtained for an individual firm is a point estimate without any confidence interval around it. In recent years, researchers have resorted to bootstrapping in order to generate empirical distributions of efficiency scores. This procedure assumes that all firms have the same probability of getting an efficiency score from any specified interval within the [0,1] range. We propose a bootstrap procedure that empirically generates the conditional distribution of efficiency for each individual firm given systematic factors that influence its efficiency. Instead of resampling directly from the pooled DEA scores, we first regress these scores on a set of explanatory variables not included at the DEA stage and bootstrap the residuals from this regression. These pseudo-efficiency scores incorporate the systematic effects of unit-specific factors along with the contribution of the randomly drawn residual. Data from the U.S. airline industry are utilized in an empirical application.
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Herbicides are used to control the growth of weeds along highways, power lines, and many other urban locations. Exposure to herbicides has been linked to adverse health outcomes. This study was initiated to pretest for the presence of herbicides in multiple water sources near intersections in a corridor in the Northwest Harris County (specifically in the Highway 6/FM 1960, North Freeway 45, US 290 and S 99 corridor). Roadside water and tap water samples were collected and analyzed for herbicides using the established Environmental Protection Agency (EPA) Method 515.4: "Determination of Chlorinated Acids in Drinking Water by Liquid-Liquid Micro-extraction, Derivatization, and Fast Gas Chromatography with Electron Capture Detection." A standard operating procedure (adapted from the US EPA Method 515.4) was developed for subsequent, larger studies of environmental fate of herbicides and non-occupational exposure risks. Preliminary testing of 16 water samples was performed to pretest the existence of trace herbicides; all concentrations that were greater than the minimum reporting limits of each analyte are reported with a 99 percent confidence. This study failed to find concentrations above the limits of detection of the method in any of the samples collected on June 15, 2008. However, this does not indicate that the waters around the NW Harris County are free of herbicides and metabolites. A larger and repeated sampling in the region would be necessary to make that claim. ^
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Although the processes involved in rational patient targeting may be obvious for certain services, for others, both the appropriate sub-populations to receive services and the procedures to be used for their identification may be unclear. This project was designed to address several research questions which arise in the attempt to deliver appropriate services to specific populations. The related difficulties are particularly evident for those interventions about which findings regarding effectiveness are conflicting. When an intervention clearly is not beneficial (or is dangerous) to a large, diverse population, consensus regarding withholding the intervention from dissemination can easily be reached. When findings are ambiguous, however, conclusions may be impossible.^ When characteristics of patients likely to benefit from an intervention are not obvious, and when the intervention is not significantly invasive or dangerous, the strategy proposed herein may be used to identify specific characteristics of sub-populations which may benefit from the intervention. The identification of these populations may be used both in further informing decisions regarding distribution of the intervention and for purposes of planning implementation of the intervention by identifying specific target populations for service delivery.^ This project explores a method for identifying such sub-populations through the use of related datasets generated from clinical trials conducted to test the effectiveness of an intervention. The method is specified in detail and tested using the example intervention of case management for outpatient treatment of populations with chronic mental illness. These analyses were applied in order to identify any characteristics which distinguish specific sub-populations who are more likely to benefit from case management service, despite conflicting findings regarding its effectiveness for the aggregate population, as reported in the body of related research. However, in addition to a limited set of characteristics associated with benefit, the findings generated, a larger set of characteristics of patients likely to experience greater improvement without intervention. ^