47 CFR 1.957 - Procedure with respect to amateur radio operator license.

Code of Federal Regulations, 2014 CFR

2014-10-01

... AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.957 Procedure with respect to amateur radio operator license. Each... 47 Telecommunication 1 2014-10-01 2014-10-01 false Procedure with respect to amateur radio...

47 CFR 1.957 - Procedure with respect to amateur radio operator license.

Code of Federal Regulations, 2012 CFR

2012-10-01

... AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.957 Procedure with respect to amateur radio operator license. Each... 47 Telecommunication 1 2012-10-01 2012-10-01 false Procedure with respect to amateur radio...

47 CFR 1.926 - Application processing; initial procedures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Application processing; initial procedures. 1.926 Section 1.926 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements...

47 CFR 1.926 - Application processing; initial procedures.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Application processing; initial procedures. 1.926 Section 1.926 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements...

47 CFR 1.926 - Application processing; initial procedures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Application processing; initial procedures. 1.926 Section 1.926 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements...

Alternative Modal Basis Selection Procedures For Reduced-Order Nonlinear Random Response Simulation

NASA Technical Reports Server (NTRS)

Przekop, Adam; Guo, Xinyun; Rizi, Stephen A.

2012-01-01

Three procedures to guide selection of an efficient modal basis in a nonlinear random response analysis are examined. One method is based only on proper orthogonal decomposition, while the other two additionally involve smooth orthogonal decomposition. Acoustic random response problems are employed to assess the performance of the three modal basis selection approaches. A thermally post-buckled beam exhibiting snap-through behavior, a shallowly curved arch in the auto-parametric response regime and a plate structure are used as numerical test articles. The results of a computationally taxing full-order analysis in physical degrees of freedom are taken as the benchmark for comparison with the results from the three reduced-order analyses. For the cases considered, all three methods are shown to produce modal bases resulting in accurate and computationally efficient reduced-order nonlinear simulations.

47 CFR 1.1621 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Definitions. 1.1621 Section 1.1621 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1621 Definitions. (a) Medium of mass communications means...

47 CFR 1.1621 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 1 2011-10-01 2011-10-01 false Definitions. 1.1621 Section 1.1621 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1621 Definitions. (a) Medium of mass communications means...

47 CFR 1.1623 - Probability calculation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Probability calculation. 1.1623 Section 1.1623 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1623 Probability calculation. (a) All calculations shall be...

47 CFR 1.1601 - Scope.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Scope. 1.1601 Section 1.1601 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1601 Scope. The provisions of this subpart, and the provisions...

47 CFR 1.1601 - Scope.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 1 2011-10-01 2011-10-01 false Scope. 1.1601 Section 1.1601 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1601 Scope. The provisions of this subpart, and the provisions...

Selection of Variables in Cluster Analysis: An Empirical Comparison of Eight Procedures

ERIC Educational Resources Information Center

Steinley, Douglas; Brusco, Michael J.

2008-01-01

Eight different variable selection techniques for model-based and non-model-based clustering are evaluated across a wide range of cluster structures. It is shown that several methods have difficulties when non-informative variables (i.e., random noise) are included in the model. Furthermore, the distribution of the random noise greatly impacts the…

Just-in-time consent: The ethical case for an alternative to traditional informed consent in randomized trials comparing an experimental intervention with usual care.

PubMed

Vickers, Andrew J; Young-Afat, Danny A; Ehdaie, Behfar; Kim, Scott Yh

2018-02-01

Informed consent for randomized trials often causes significant and persistent anxiety, distress and confusion to patients. Where an experimental treatment is compared to a standard care control, much of this burden is potentially avoidable in the control group. We propose a "just-in-time" consent in which consent discussions take place in two stages: an initial consent to research from all participants and a later specific consent to randomized treatment only from those assigned to the experimental intervention. All patients are first approached and informed about research procedures, such as questionnaires or tests. They are also informed that they might be randomly selected to receive an experimental treatment and that, if selected, they can learn more about the treatment and decide whether or not to accept it at that time. After randomization, control patients undergo standard clinical consent whereas patients randomized to the experimental procedure undergo a second consent discussion. Analysis would be by intent-to-treat, which protects the trial from selection bias, although not from poor acceptance of experimental treatment. The advantages of just-in-time consent stem from the fact that only patients randomized to the experimental treatment are subject to a discussion of that intervention. We hypothesize that this will reduce much of the patient's burden associated with the consent process, such as decisional anxiety, confusion and information overload. We recommend well-controlled studies to compare just-in-time and traditional consent, with endpoints to include characteristics of participants, distress and anxiety and participants' understanding of research procedures.

People's Need for Additional Job Training: Development and Evaluation of an Assessment Procedure.

ERIC Educational Resources Information Center

Copa, George H.; Maurice, Clyde F.

A procedure was developed and evaluated for assessing the self-perceived educational needs of people as one input to the process of planning, approving, and implementing relevant educational programs. The method of data collection involved selecting samples of people by randomly selecting households in a given geographic area, and then contacting…

47 CFR 1.824 - Random selection procedures for Multichannel Multipoint Distribution Service and Multipoint...

Code of Federal Regulations, 2010 CFR

2010-10-01

... an ownership interest of more than 50 percent in the media of mass communication whose service areas... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Complaints, Applications, Tariffs...

Randomization in clinical trials in orthodontics: its significance in research design and methods to achieve it.

PubMed

Pandis, Nikolaos; Polychronopoulou, Argy; Eliades, Theodore

2011-12-01

Randomization is a key step in reducing selection bias during the treatment allocation phase in randomized clinical trials. The process of randomization follows specific steps, which include generation of the randomization list, allocation concealment, and implementation of randomization. The phenomenon in the dental and orthodontic literature of characterizing treatment allocation as random is frequent; however, often the randomization procedures followed are not appropriate. Randomization methods assign, at random, treatment to the trial arms without foreknowledge of allocation by either the participants or the investigators thus reducing selection bias. Randomization entails generation of random allocation, allocation concealment, and the actual methodology of implementing treatment allocation randomly and unpredictably. Most popular randomization methods include some form of restricted and/or stratified randomization. This article introduces the reasons, which make randomization an integral part of solid clinical trial methodology, and presents the main randomization schemes applicable to clinical trials in orthodontics.

US EPA Base Study Standard Operating Procedure for Building Recruiting

EPA Pesticide Factsheets

Building recruiting for the BASE study is defined by a random selection of buildings within cities of population exceeding 100,000 inhabitants and located in selected climatic regions of the United States.

A comparative study of restricted randomization procedures for multiarm trials with equal or unequal treatment allocation ratios.

PubMed

Ryeznik, Yevgen; Sverdlov, Oleksandr

2018-06-04

Randomization designs for multiarm clinical trials are increasingly used in practice, especially in phase II dose-ranging studies. Many new methods have been proposed in the literature; however, there is lack of systematic, head-to-head comparison of the competing designs. In this paper, we systematically investigate statistical properties of various restricted randomization procedures for multiarm trials with fixed and possibly unequal allocation ratios. The design operating characteristics include measures of allocation balance, randomness of treatment assignments, variations in the allocation ratio, and statistical characteristics such as type I error rate and power. The results from the current paper should help clinical investigators select an appropriate randomization procedure for their clinical trial. We also provide a web-based R shiny application that can be used to reproduce all results in this paper and run simulations under additional user-defined experimental scenarios. Copyright © 2018 John Wiley & Sons, Ltd.

47 CFR 1.956 - Settlement conferences.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Settlement conferences. 1.956 Section 1.956 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.956...

47 CFR 1.956 - Settlement conferences.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Settlement conferences. 1.956 Section 1.956 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.956...

47 CFR 1.956 - Settlement conferences.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Settlement conferences. 1.956 Section 1.956 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.956...

47 CFR 1.958 - Distance computation.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Distance computation. 1.958 Section 1.958 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.958...

47 CFR 1.958 - Distance computation.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Distance computation. 1.958 Section 1.958 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.958...

47 CFR 1.958 - Distance computation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Distance computation. 1.958 Section 1.958 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.958...

47 CFR 1.911 - Station files.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Station files. 1.911 Section 1.911 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.911...

47 CFR 1.911 - Station files.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Station files. 1.911 Section 1.911 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.911...

47 CFR 1.911 - Station files.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Station files. 1.911 Section 1.911 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.911...

Use of Matrix Sampling Procedures to Assess Achievement in Solving Open Addition and Subtraction Sentences.

ERIC Educational Resources Information Center

Montague, Margariete A.

This study investigated the feasibility of concurrently and randomly sampling examinees and items in order to estimate group achievement. Seven 32-item tests reflecting a 640-item universe of simple open sentences were used such that item selection (random, systematic) and assignment (random, systematic) of items (four, eight, sixteen) to forms…

47 CFR 1.947 - Modification of licenses.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Modification of licenses. 1.947 Section 1.947 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.947...

47 CFR 1.927 - Amendment of applications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Amendment of applications. 1.927 Section 1.927 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.927...

47 CFR 1.927 - Amendment of applications.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Amendment of applications. 1.927 Section 1.927 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.927...

47 CFR 1.947 - Modification of licenses.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Modification of licenses. 1.947 Section 1.947 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.947...

47 CFR 1.939 - Petitions to deny.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Petitions to deny. 1.939 Section 1.939 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.939...

47 CFR 1.927 - Amendment of applications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Amendment of applications. 1.927 Section 1.927 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.927...

47 CFR 1.947 - Modification of licenses.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Modification of licenses. 1.947 Section 1.947 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.947...

47 CFR 1.939 - Petitions to deny.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Petitions to deny. 1.939 Section 1.939 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.939...

47 CFR 1.939 - Petitions to deny.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Petitions to deny. 1.939 Section 1.939 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.939...

Effect of Spinal Manipulative Therapy on the Singing Voice.

PubMed

Fachinatto, Ana Paula A; Duprat, André de Campos; Silva, Marta Andrada E; Bracher, Eduardo Sawaya Botelho; Benedicto, Camila de Carvalho; Luz, Victor Botta Colangelo; Nogueira, Maruan Nogueira; Fonseca, Beatriz Suster Gomes

2015-09-01

This study investigated the effect of spinal manipulative therapy (SMT) on the singing voice of male individuals. Randomized, controlled, case-crossover trial. Twenty-nine subjects were selected among male members of the Heralds of the Gospel. This association was chosen because it is a group of persons with similar singing activities. Participants were randomly assigned to two groups: (A) chiropractic SMT procedure and (B) nontherapeutic transcutaneous electrical nerve stimulation (TENS) procedure. Recordings of the singing voice of each participant were taken immediately before and after the procedures. After a 14-day period, procedures were switched between groups: participants who underwent SMT on the first day were subjected to TENS and vice versa. Recordings were subjected to perceptual audio and acoustic evaluations. The same recording segment of each participant was selected. Perceptual audio evaluation was performed by a specialist panel (SP). Recordings of each participant were randomly presented thus making the SP blind to intervention type and recording session (before/after intervention). Recordings compiled in a randomized order were also subjected to acoustic evaluation. No differences in the quality of the singing on perceptual audio evaluation were observed between TENS and SMT. No differences in the quality of the singing voice of asymptomatic male singers were observed on perceptual audio evaluation or acoustic evaluation after a single spinal manipulative intervention of the thoracic and cervical spine. Copyright © 2015 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR ELECTRONIC DATA QA CHECK (HAND ENTRY AND SCANNED) (UA-D-26.0)

EPA Science Inventory

The purpose of this SOP is to define the procedure for conducting a data accuracy check on a randomly selected 10% sample of all electronic data. This procedure applies to the cleaned, working databases generated during the Arizona NHEXAS project and the "Border" study. Keyword...

32 CFR 1624.1 - Random selection procedures for induction.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., during the specified calendar year(s) attain their 18th year of birth. The drawing, commencing with the... date of birth of the registrant that appears on his Selective Service Registration Record on the day... date of birth in all matters pertaining to his relations with the Selective Service System. ...

IMBLMS phase B4, additional tasks 5.0. Microbial identification system

NASA Technical Reports Server (NTRS)

1971-01-01

A laboratory study was undertaken to provide simplified procedures leading to the presumptive identification (I/D) of defined microorganisms on-board an orbiting spacecraft. Identifications were to be initiated by nonprofessional bacteriologists, (crew members) on a contingency basis only. Key objectives/constraints for this investigation were as follows:(1) I/D procedures based on limited, defined diagnostic tests, (2) testing oriented about ten selected microorganisms, (3) provide for definitive I/D key and procedures per selected organism, (4) define possible occurrences of false positives for the resulting I/D key by search of the appropriate literature, and (5) evaluation of the I/D key and procedure through a limited field trial on randomly selected subjects using the I/D key.

47 CFR 1.9060 - Amendments, waivers, and dismissals affecting spectrum leasing notifications and applications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... spectrum leasing notifications and applications. 1.9060 Section 1.9060 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9060 Amendments, waivers, and dismissals affecting spectrum leasing...

47 CFR 1.9060 - Amendments, waivers, and dismissals affecting spectrum leasing notifications and applications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... spectrum leasing notifications and applications. 1.9060 Section 1.9060 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9060 Amendments, waivers, and dismissals affecting spectrum leasing...

47 CFR 1.9060 - Amendments, waivers, and dismissals affecting spectrum leasing notifications and applications.

Code of Federal Regulations, 2014 CFR

2014-10-01

... spectrum leasing notifications and applications. 1.9060 Section 1.9060 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9060 Amendments, waivers, and dismissals affecting spectrum leasing...

Inverse probability weighting for covariate adjustment in randomized studies

PubMed Central

Li, Xiaochun; Li, Lingling

2013-01-01

SUMMARY Covariate adjustment in randomized clinical trials has the potential benefit of precision gain. It also has the potential pitfall of reduced objectivity as it opens the possibility of selecting “favorable” model that yields strong treatment benefit estimate. Although there is a large volume of statistical literature targeting on the first aspect, realistic solutions to enforce objective inference and improve precision are rare. As a typical randomized trial needs to accommodate many implementation issues beyond statistical considerations, maintaining the objectivity is at least as important as precision gain if not more, particularly from the perspective of the regulatory agencies. In this article, we propose a two-stage estimation procedure based on inverse probability weighting to achieve better precision without compromising objectivity. The procedure is designed in a way such that the covariate adjustment is performed before seeing the outcome, effectively reducing the possibility of selecting a “favorable” model that yields a strong intervention effect. Both theoretical and numerical properties of the estimation procedure are presented. Application of the proposed method to a real data example is presented. PMID:24038458

Inverse probability weighting for covariate adjustment in randomized studies.

PubMed

Shen, Changyu; Li, Xiaochun; Li, Lingling

2014-02-20

Covariate adjustment in randomized clinical trials has the potential benefit of precision gain. It also has the potential pitfall of reduced objectivity as it opens the possibility of selecting a 'favorable' model that yields strong treatment benefit estimate. Although there is a large volume of statistical literature targeting on the first aspect, realistic solutions to enforce objective inference and improve precision are rare. As a typical randomized trial needs to accommodate many implementation issues beyond statistical considerations, maintaining the objectivity is at least as important as precision gain if not more, particularly from the perspective of the regulatory agencies. In this article, we propose a two-stage estimation procedure based on inverse probability weighting to achieve better precision without compromising objectivity. The procedure is designed in a way such that the covariate adjustment is performed before seeing the outcome, effectively reducing the possibility of selecting a 'favorable' model that yields a strong intervention effect. Both theoretical and numerical properties of the estimation procedure are presented. Application of the proposed method to a real data example is presented. Copyright © 2013 John Wiley & Sons, Ltd.

Selection dynamic of Escherichia coli host in M13 combinatorial peptide phage display libraries.

PubMed

Zanconato, Stefano; Minervini, Giovanni; Poli, Irene; De Lucrezia, Davide

2011-01-01

Phage display relies on an iterative cycle of selection and amplification of random combinatorial libraries to enrich the initial population of those peptides that satisfy a priori chosen criteria. The effectiveness of any phage display protocol depends directly on library amino acid sequence diversity and the strength of the selection procedure. In this study we monitored the dynamics of the selective pressure exerted by the host organism on a random peptide library in the absence of any additional selection pressure. The results indicate that sequence censorship exerted by Escherichia coli dramatically reduces library diversity and can significantly impair phage display effectiveness.

"Congratulations, you have been randomized into the control group!(?)": issues to consider when recruiting schools for matched-pair randomized control trials of prevention programs.

PubMed

Ji, Peter; DuBois, David L; Flay, Brian R; Brechling, Vanessa

2008-03-01

Recruiting schools into a matched-pair randomized control trial (MP-RCT) to evaluate the efficacy of a school-level prevention program presents challenges for researchers. We considered which of 2 procedures would be most effective for recruiting schools into the study and assigning them to conditions. In 1 procedure (recruit and match/randomize), we would recruit schools and match them prior to randomization, and in the other (match/randomize and recruitment), we would match schools and randomize them prior to recruitment. We considered how each procedure impacted the randomization process and our ability to recruit schools into the study. After implementing the selected procedure, the equivalence of both treatment and control group schools and the participating and nonparticipating schools on school demographic variables was evaluated. We decided on the recruit and match/randomize procedure because we thought it would provide the opportunity to build rapport with the schools and prepare them for the randomization process, thereby increasing the likelihood that they would accept their randomly assigned conditions. Neither the treatment and control group schools nor the participating and nonparticipating schools exhibited statistically significant differences from each other on any of the school demographic variables. Recruitment of schools prior to matching and randomization in an MP-RCT may facilitate the recruitment of schools and thus enhance both the statistical power and the representativeness of study findings. Future research would benefit from the consideration of a broader range of variables (eg, readiness to implement a comprehensive prevention program) both in matching schools and in evaluating their representativeness to nonparticipating schools.

47 CFR 1.9047 - Special provisions relating to leases of educational broadband service spectrum.

Code of Federal Regulations, 2014 CFR

2014-10-01

... educational broadband service spectrum. 1.9047 Section 1.9047 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9047 Special provisions relating to leases of educational broadband service spectrum...

47 CFR 1.9040 - Contractual requirements applicable to spectrum leasing arrangements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Contractual requirements applicable to spectrum... PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9040 Contractual requirements applicable to spectrum leasing arrangements. (a) Agreements between licensees and...

47 CFR 1.9040 - Contractual requirements applicable to spectrum leasing arrangements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Contractual requirements applicable to spectrum... PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9040 Contractual requirements applicable to spectrum leasing arrangements. (a) Agreements between licensees and...

47 CFR 1.9040 - Contractual requirements applicable to spectrum leasing arrangements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Contractual requirements applicable to spectrum... PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9040 Contractual requirements applicable to spectrum leasing arrangements. (a) Agreements between licensees and...

47 CFR 1.9047 - Special provisions relating to leases of educational broadband service spectrum.

Code of Federal Regulations, 2013 CFR

2013-10-01

... educational broadband service spectrum. 1.9047 Section 1.9047 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9047 Special provisions relating to leases of educational broadband service spectrum...

47 CFR 1.9047 - Special provisions relating to leases of educational broadband service spectrum.

Code of Federal Regulations, 2012 CFR

2012-10-01

... educational broadband service spectrum. 1.9047 Section 1.9047 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9047 Special provisions relating to leases of educational broadband service spectrum...

Distributive and Procedural Justice as Related to Satisfaction and Commitment.

ERIC Educational Resources Information Center

Tang, Thomas Li-Ping; Sarsfield-Baldwin, Linda J.

Randomly selected employees from a Veterans Administration Medical Center (n=200) were asked to complete measures on distributive justice and procedural justice 4 weeks before their performance appraisal; and on job satisfaction, commitment, involvement, and self-reported performance feedback 4 weeks after their performance appraisals.…

Collective Negotiations and Teacher Satisfaction in Selected Indiana Secondary Schools.

ERIC Educational Resources Information Center

Davies, Paul R.; Kline, Charles E.

This paper reports a study that sought to determine whether differences in bargaining procedures are related to differences in teacher satisfaction or morale. Of the forty schools in the random sample, 27 were operating under traditional collective negotiation procedures -- teachers relatively unorganized; eight were operating under procedural…

47 CFR 1.9048 - Special provisions relating to spectrum leasing arrangements involving licensees in the Public...

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Special provisions relating to spectrum leasing... FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9048 Special provisions relating to spectrum leasing...

47 CFR 1.9055 - Assignment of file numbers to spectrum leasing notifications and applications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Assignment of file numbers to spectrum leasing... GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9055 Assignment of file numbers to spectrum leasing notifications and applications. Spectrum...

47 CFR 1.9055 - Assignment of file numbers to spectrum leasing notifications and applications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Assignment of file numbers to spectrum leasing... GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9055 Assignment of file numbers to spectrum leasing notifications and applications. Spectrum...

47 CFR 1.9010 - De facto control standard for spectrum leasing arrangements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false De facto control standard for spectrum leasing... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9010 De facto control standard for spectrum leasing arrangements. (a) Under the rules established for spectrum leasing...

47 CFR 1.9048 - Special provisions relating to spectrum leasing arrangements involving licensees in the Public...

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Special provisions relating to spectrum leasing... FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9048 Special provisions relating to spectrum leasing...

47 CFR 1.9055 - Assignment of file numbers to spectrum leasing notifications and applications.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Assignment of file numbers to spectrum leasing... GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9055 Assignment of file numbers to spectrum leasing notifications and applications. Spectrum...

47 CFR 1.9010 - De facto control standard for spectrum leasing arrangements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false De facto control standard for spectrum leasing... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9010 De facto control standard for spectrum leasing arrangements. (a) Under the rules established for spectrum leasing...

47 CFR 1.9010 - De facto control standard for spectrum leasing arrangements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false De facto control standard for spectrum leasing... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9010 De facto control standard for spectrum leasing arrangements. (a) Under the rules established for spectrum leasing...

47 CFR 1.9048 - Special provisions relating to spectrum leasing arrangements involving licensees in the Public...

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Special provisions relating to spectrum leasing... FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9048 Special provisions relating to spectrum leasing...

Empirical versus Random Item Selection in the Design of Intelligence Test Short Forms--The WISC-R Example.

ERIC Educational Resources Information Center

Goh, David S.

1979-01-01

The advantages of using psychometric thoery to design short forms of intelligence tests are demonstrated by comparing such usage to a systematic random procedure that has previously been used. The Wechsler Intelligence Scale for Children Revised (WISC-R) Short Form is presented as an example. (JKS)

78 FR 54653 - Proposed Data Collections Submitted for Public Comment and Recommendations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-05

... materials on opinions about CRC screening tests. Each respondent will be randomly assigned to one of three... treatment group that receives a ``No Excuses'' educational flyer designed to dispel many common reasons for... randomly selected from the KN KnowledgePanel[supreg]. A pre-test of study procedures will be conducted...

Input variable selection and calibration data selection for storm water quality regression models.

PubMed

Sun, Siao; Bertrand-Krajewski, Jean-Luc

2013-01-01

Storm water quality models are useful tools in storm water management. Interest has been growing in analyzing existing data for developing models for urban storm water quality evaluations. It is important to select appropriate model inputs when many candidate explanatory variables are available. Model calibration and verification are essential steps in any storm water quality modeling. This study investigates input variable selection and calibration data selection in storm water quality regression models. The two selection problems are mutually interacted. A procedure is developed in order to fulfil the two selection tasks in order. The procedure firstly selects model input variables using a cross validation method. An appropriate number of variables are identified as model inputs to ensure that a model is neither overfitted nor underfitted. Based on the model input selection results, calibration data selection is studied. Uncertainty of model performances due to calibration data selection is investigated with a random selection method. An approach using the cluster method is applied in order to enhance model calibration practice based on the principle of selecting representative data for calibration. The comparison between results from the cluster selection method and random selection shows that the former can significantly improve performances of calibrated models. It is found that the information content in calibration data is important in addition to the size of calibration data.

47 CFR 1.9035 - Short-term de facto transfer leasing arrangements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9035 Short-term de... any of the included services) and a spectrum lessee may enter into a short-term de facto transfer... the leased spectrum is transferred to the spectrum lessee for the duration of the spectrum leasing...

47 CFR 1.9050 - Who may sign spectrum leasing notifications and applications.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Who may sign spectrum leasing notifications and... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9050 Who may sign spectrum leasing notifications and applications. Under the rules set forth in this subpart, certain...

47 CFR 1.9050 - Who may sign spectrum leasing notifications and applications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Who may sign spectrum leasing notifications and... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9050 Who may sign spectrum leasing notifications and applications. Under the rules set forth in this subpart, certain...

47 CFR 1.9050 - Who may sign spectrum leasing notifications and applications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Who may sign spectrum leasing notifications and... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9050 Who may sign spectrum leasing notifications and applications. Under the rules set forth in this subpart, certain...

47 CFR 1.9035 - Short-term de facto transfer leasing arrangements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9035 Short-term de... any of the included services) and a spectrum lessee may enter into a short-term de facto transfer... the leased spectrum is transferred to the spectrum lessee for the duration of the spectrum leasing...

47 CFR 1.9035 - Short-term de facto transfer leasing arrangements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9035 Short-term de... any of the included services) and a spectrum lessee may enter into a short-term de facto transfer... the leased spectrum is transferred to the spectrum lessee for the duration of the spectrum leasing...

Selection of stable scFv antibodies by phage display.

PubMed

Brockmann, Eeva-Christine

2012-01-01

ScFv fragments are popular recombinant antibody formats but often suffer from limited stability. Phage display is a powerful tool in antibody engineering and applicable also for stability selection. ScFv variants with improved stability can be selected from large randomly mutated phage displayed libraries with a specific antigen after the unstable variants have been inactivated by heat or GdmCl. Irreversible scFv denaturation, which is a prerequisite for efficient selection, is achieved by combining denaturation with reduction of the intradomain disulfide bonds. Repeated selection cycles of increasing stringency result in enrichment of stabilized scFv fragments. Procedures for constructing a randomly mutated scFv library by error-prone PCR and phage display selection for enrichment of stable scFv antibodies from the library are described here.

An investigation into the probabilistic combination of quasi-static and random accelerations

NASA Technical Reports Server (NTRS)

Schock, R. W.; Tuell, L. P.

1984-01-01

The development of design load factors for aerospace and aircraft components and experiment support structures, which are subject to a simultaneous vehicle dynamic vibration (quasi-static) and acoustically generated random vibration, require the selection of a combination methodology. Typically, the procedure is to define the quasi-static and the random generated response separately, and arithmetically add or root sum square to get combined accelerations. Since the combination of a probabilistic and a deterministic function yield a probabilistic function, a viable alternate approach would be to determine the characteristics of the combined acceleration probability density function and select an appropriate percentile level for the combined acceleration. The following paper develops this mechanism and provides graphical data to select combined accelerations for most popular percentile levels.

An Investigation of Plans and Procedures for Increasing Student Enrollments in Selected Southern California Community Colleges.

ERIC Educational Resources Information Center

Huguley, Sally M.

A study involving interviews with administrators at seven randomly selected Southern California community colleges was conducted to identify the marketing strategies undertaken by these institutions to increase student recruitment. During the interviews, respondents were asked to: (1) outline the functions of their public relations office; (2)…

Validity and Reliability of Psychosocial Factors Related to Breast Cancer Screening.

ERIC Educational Resources Information Center

Zapka, Jane G.; And Others

1991-01-01

The construct validity of hypothesized survey items and data reduction procedures for selected psychosocial constructs frequently used in breast cancer screening research were investigated in telephone interviews with randomly selected samples of 1,184 and 903 women and a sample of 169 Hispanic clinic clients. Validity of the constructs is…

47 CFR 1.992 - How to calculate indirect equity and voting interests.

Code of Federal Regulations, 2013 CFR

2013-10-01

... PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Foreign Ownership of Common Carrier, Aeronautical En Route, and Aeronautical Fixed Radio Station Licensees § 1.992 How...

47 CFR 1.992 - How to calculate indirect equity and voting interests.

Code of Federal Regulations, 2014 CFR

2014-10-01

... PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Foreign Ownership of Common Carrier, Aeronautical En Route, and Aeronautical Fixed Radio Station Licensees § 1.992 How...

Effects of Sample Selection on Estimates of Economic Impacts of Outdoor Recreation

Treesearch

Donald B.K. English

1997-01-01

Estimates of the economic impacts of recreation often come from spending data provided by a self-selected subset of a random sample of site visitors. The subset is frequently less than half the onsite sample. Biased vectors of per trip spending and impact estimates can result if self-selection is related to spending pattctns, and proper corrective procedures arc not...

Decision tree modeling using R.

PubMed

Zhang, Zhongheng

2016-08-01

In machine learning field, decision tree learner is powerful and easy to interpret. It employs recursive binary partitioning algorithm that splits the sample in partitioning variable with the strongest association with the response variable. The process continues until some stopping criteria are met. In the example I focus on conditional inference tree, which incorporates tree-structured regression models into conditional inference procedures. While growing a single tree is subject to small changes in the training data, random forests procedure is introduced to address this problem. The sources of diversity for random forests come from the random sampling and restricted set of input variables to be selected. Finally, I introduce R functions to perform model based recursive partitioning. This method incorporates recursive partitioning into conventional parametric model building.

VARIABLE SELECTION FOR REGRESSION MODELS WITH MISSING DATA

PubMed Central

Garcia, Ramon I.; Ibrahim, Joseph G.; Zhu, Hongtu

2009-01-01

We consider the variable selection problem for a class of statistical models with missing data, including missing covariate and/or response data. We investigate the smoothly clipped absolute deviation penalty (SCAD) and adaptive LASSO and propose a unified model selection and estimation procedure for use in the presence of missing data. We develop a computationally attractive algorithm for simultaneously optimizing the penalized likelihood function and estimating the penalty parameters. Particularly, we propose to use a model selection criterion, called the ICQ statistic, for selecting the penalty parameters. We show that the variable selection procedure based on ICQ automatically and consistently selects the important covariates and leads to efficient estimates with oracle properties. The methodology is very general and can be applied to numerous situations involving missing data, from covariates missing at random in arbitrary regression models to nonignorably missing longitudinal responses and/or covariates. Simulations are given to demonstrate the methodology and examine the finite sample performance of the variable selection procedures. Melanoma data from a cancer clinical trial is presented to illustrate the proposed methodology. PMID:20336190

Evaluation of Model Specification, Variable Selection, and Adjustment Methods in Relation to Propensity Scores and Prognostic Scores in Multilevel Data

ERIC Educational Resources Information Center

Yu, Bing; Hong, Guanglei

2012-01-01

This study uses simulation examples representing three types of treatment assignment mechanisms in data generation (the random intercept and slopes setting, the random intercept setting, and a third setting with a cluster-level treatment and an individual-level outcome) in order to determine optimal procedures for reducing bias and improving…

Teachers' Methodologies and Sources of Information on HIV/AIDS for Students with Visual Impairments in Selected Residential and Integrated Schools in Ghana

ERIC Educational Resources Information Center

Hayford, Samuel K.; Ocansey, Frederick

2017-01-01

This study reports part of a national survey on sources of information, education and communication materials on HIV/AIDS available to students with visual impairments in residential, segregated, and integrated schools in Ghana. A multi-staged stratified random sampling procedure and a purposive and simple random sampling approach, where…

Factors Associated With Time to Site Activation, Randomization, and Enrollment Performance in a Stroke Prevention Trial.

PubMed

Demaerschalk, Bart M; Brown, Robert D; Roubin, Gary S; Howard, Virginia J; Cesko, Eldina; Barrett, Kevin M; Longbottom, Mary E; Voeks, Jenifer H; Chaturvedi, Seemant; Brott, Thomas G; Lal, Brajesh K; Meschia, James F; Howard, George

2017-09-01

Multicenter clinical trials attempt to select sites that can move rapidly to randomization and enroll sufficient numbers of patients. However, there are few assessments of the success of site selection. In the CREST-2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trials), we assess factors associated with the time between site selection and authorization to randomize, the time between authorization to randomize and the first randomization, and the average number of randomizations per site per month. Potential factors included characteristics of the site, specialty of the principal investigator, and site type. For 147 sites, the median time between site selection to authorization to randomize was 9.9 months (interquartile range, 7.7, 12.4), and factors associated with early site activation were not identified. The median time between authorization to randomize and a randomization was 4.6 months (interquartile range, 2.6, 10.5). Sites with authorization to randomize in only the carotid endarterectomy study were slower to randomize, and other factors examined were not significantly associated with time-to-randomization. The recruitment rate was 0.26 (95% confidence interval, 0.23-0.28) patients per site per month. By univariate analysis, factors associated with faster recruitment were authorization to randomize in both trials, principal investigator specialties of interventional radiology and cardiology, pre-trial reported performance >50 carotid angioplasty and stenting procedures per year, status in the top half of recruitment in the CREST trial, and classification as a private health facility. Participation in StrokeNet was associated with slower recruitment as compared with the non-StrokeNet sites. Overall, selection of sites with high enrollment rates will likely require customization to align the sites selected to the factor under study in the trial. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02089217. © 2017 American Heart Association, Inc.

Capture-SELEX: Selection of DNA Aptamers for Aminoglycoside Antibiotics

PubMed Central

2012-01-01

Small organic molecules are challenging targets for an aptamer selection using the SELEX technology (SELEX—Systematic Evolution of Ligans by EXponential enrichment). Often they are not suitable for immobilization on solid surfaces, which is a common procedure in known aptamer selection methods. The Capture-SELEX procedure allows the selection of DNA aptamers for solute targets. A special SELEX library was constructed with the aim to immobilize this library on magnetic beads or other surfaces. For this purpose a docking sequence was incorporated into the random region of the library enabling hybridization to a complementary oligo fixed on magnetic beads. Oligonucleotides of the library which exhibit high affinity to the target and a secondary structure fitting to the target are released from the beads for binding to the target during the aptamer selection process. The oligonucleotides of these binding complexes were amplified, purified, and immobilized via the docking sequence to the magnetic beads as the starting point of the following selection round. Based on this Capture-SELEX procedure, the successful DNA aptamer selection for the aminoglycoside antibiotic kanamycin A as a small molecule target is described. PMID:23326761

What Every Public School Physical Educator Should Know about the Hiring Process

ERIC Educational Resources Information Center

Stier, William F., Jr.; Schneider, Robert C.

2007-01-01

A national survey of high school principals was conducted to determine whether they agreed or disagreed with selected practices and procedures used to hire high school physical education teachers. A survey instrument, developed with the help of experts in the field and consisting of 29 items, was sent to 400 randomly selected principals. Useable…

The validation of procedures to assess prevocational task preferences in retarded adults.

PubMed

Mithaug, D E; Hanawalt, D A

1978-01-01

Three severely retarded young adults between the ages of 19 and 21 years participated in a prevocational training program, and worked regularly on six different tasks during the scheduled six-hour day. The study attempted to assess each subject's preferences for the six tasks: collating, stuffing, sorting, pulley assembly, flour-sifter assembly, and circuit-board stuffing. In Phase I, the procedure consisted of randomly pairing each task with all other tasks in a two-choice situation that required the subjects to select one task from each pair combination to work for a seven-minute period. The selection procedure consisted of presenting two representative task objects on a tray and requesting the subject to pick up one object and place it on the work table. The object selected represented the task worked for that period. The 15 possible pair combinations were presented randomly every two days for a period of 34 days to determine the preferences. During the validation phase (Phase II), each subject's least- and most-preferred tasks were paired separately with moderately-preferred tasks. As expected, these manipulations confirmed the baseline data, as choices for the moderately-preferred tasks decreased when consistently paired with the preferred tasks and increased when consistently paired with the least-preferred tasks.

A reliability-based cost effective fail-safe design procedure

NASA Technical Reports Server (NTRS)

Hanagud, S.; Uppaluri, B.

1976-01-01

The authors have developed a methodology for cost-effective fatigue design of structures subject to random fatigue loading. A stochastic model for fatigue crack propagation under random loading has been discussed. Fracture mechanics is then used to estimate the parameters of the model and the residual strength of structures with cracks. The stochastic model and residual strength variations have been used to develop procedures for estimating the probability of failure and its changes with inspection frequency. This information on reliability is then used to construct an objective function in terms of either a total weight function or cost function. A procedure for selecting the design variables, subject to constraints, by optimizing the objective function has been illustrated by examples. In particular, optimum design of stiffened panel has been discussed.

Conventional versus traction-assisted endoscopic submucosal dissection for gastric neoplasms: a multicenter, randomized controlled trial (with video).

PubMed

Yoshida, Masao; Takizawa, Kohei; Suzuki, Sho; Koike, Yoshiki; Nonaka, Satoru; Yamasaki, Yasushi; Minagawa, Takeyoshi; Sato, Chiko; Takeuchi, Chihiro; Watanabe, Ko; Kanzaki, Hiromitsu; Morimoto, Hiroyuki; Yano, Takafumi; Sudo, Kosuke; Mori, Keita; Gotoda, Takuji; Ono, Hiroyuki

2018-05-01

The aim of this study was to clarify whether dental floss clip (DFC) traction improves the technical outcomes of endoscopic submucosal dissection (ESD). A superiority, randomized control trial was conducted at 14 institutions across Japan. Patients with single gastric neoplasm meeting the indications of the Japanese guidelines for gastric treatment were enrolled and assigned to receive conventional ESD or DFC traction-assisted ESD (DFC-ESD). Randomization was performed according to a computer-generated random sequence with stratification by institution, tumor location, tumor size, and operator experience. The primary endpoint was ESD procedure time, defined as the time from the start of the submucosal injection to the end of the tumor removal procedure. Between July 2015 and September 2016, 640 patients underwent randomization. Of these, 316 patients who underwent conventional ESD and 319 patients who underwent DFC-ESD were included in our analysis. The mean ESD procedure time was 60.7 and 58.1 minutes for conventional ESD and DFC-ESD, respectively (P = .45). Perforation was less frequent in the DFC-ESD group (2.2% vs .3%, P = .04). For lesions located in the greater curvature of the upper or middle stomach, the mean procedure time was significantly shorter in the DFC-ESD group (104.1 vs 57.2 minutes, P = .01). Our findings suggest that DFC-ESD does not result in shorter procedure time in the overall patient population, but it can reduce the risk of perforation. When selectively applied to lesions located in the greater curvature of the upper or middle stomach, DFC-ESD provides a remarkable reduction in procedure time. Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

How many records should be used in ASCE/SEI-7 ground motion scaling procedure?

USGS Publications Warehouse

Reyes, Juan C.; Kalkan, Erol

2012-01-01

U.S. national building codes refer to the ASCE/SEI-7 provisions for selecting and scaling ground motions for use in nonlinear response history analysis of structures. Because the limiting values for the number of records in the ASCE/SEI-7 are based on engineering experience, this study examines the required number of records statistically, such that the scaled records provide accurate, efficient, and consistent estimates of “true” structural responses. Based on elastic–perfectly plastic and bilinear single-degree-of-freedom systems, the ASCE/SEI-7 scaling procedure is applied to 480 sets of ground motions; the number of records in these sets varies from three to ten. As compared to benchmark responses, it is demonstrated that the ASCE/SEI-7 scaling procedure is conservative if fewer than seven ground motions are employed. Utilizing seven or more randomly selected records provides more accurate estimate of the responses. Selecting records based on their spectral shape and design spectral acceleration increases the accuracy and efficiency of the procedure.

47 CFR 1.955 - Termination of authorizations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Termination of authorizations. 1.955 Section 1.955 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and...

47 CFR 1.955 - Termination of authorizations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Termination of authorizations. 1.955 Section 1.955 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and...

47 CFR 1.955 - Termination of authorizations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Termination of authorizations. 1.955 Section 1.955 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and...

Transoral Incisionless Fundoplication (TIF 2.0): A Meta-Analysis of Three Randomized, Controlled Clinical Trials.

PubMed

Gerson, Lauren; Stouch, Bruce; Lobonţiu, Adrian

2018-01-01

The TIF procedure has emerged as an endoscopic treatment for patients with refractory gastro-esophageal reflux disease (GERD). Previous systematic reviews of the TIF procedure conflated findings from studies with modalities that do not reflect the current 2.0 procedure technique or refined data-backed patient selection criteria. A meta-analysis was conducted using data only from randomized studies that assessed the TIF 2.0 procedure compared to a control. The purpose of the meta-analysis was to determine the efficacy and long-term outcomes associated with performance of the TIF 2.0 procedure in patients with chronic long-term refractory GERD on optimized PPI therapy, including esophageal pH, PPI utilization and quality of life. Methods: Three prospective research questions were predicated on the outcomes of the TIF procedure compared to patients who received PPI therapy or sham, concomitant treatment for GERD, and the patient-reported quality of life. Event rates were calculated using the random effect model. Since the time of follow-up post-TIF procedure was variable, analysis was performed to incorporate the time of follow-up for each individual patient at the 3-year time point. Results: Results from this meta-analysis, including data from 233 patients, demonstrated that TIF subjects at 3 years had improved esophageal pH, a decrease in PPI utilization, and improved quality of life. Conclusions: In a meta-analysis of randomized, controlled trials (RCTs), the TIF procedure data for patients with GERD refractory to PPI's produces significant changes, compared with sham or PPI therapy, in esophageal pH, decreased PPI utilization, and improved quality of life. Celsius.

The effects of psychotomimetics and psychomotor stimulants on two schedules promoting response switching in the rat.

PubMed

Evenden, John

2002-10-01

Psychosis and psychotomimetic drugs result in a disorganisation of the structure of thought and behaviour. Normalising these is one of the objects of antipsychotic therapy, and methods for predicting such a therapeutic effect would be of value. The effects of a number of psychotomimetic agents were examined on the way in which rats distributed responding over two response levers using two different procedures, to assay their effects on behavioural organisation. Previously, amphetamine has been found to increase response switching using these schedules. In the first, the random reinforcement procedure, one of the two levers was selected at random as "correct", and responses on this lever were reinforced with food under a random ratio schedule. No signal was given to distinguish the levers. Responding could also result in the food tray being illuminated, but no food pellet was delivered ("no-food" event). Responses on the second lever ("incorrect") had no programmed consequences. After each food delivery or "no-food" event the levers designated as "correct" and "incorrect" were reassigned at random, and the rat had to open the food tray to restart the schedule. In the second procedure, the rats were required to make 21 responses before a switch between the two levers resulted in food delivery [Fixed Ratio (FR) 21-switch]. The responses making up the FR could be distributed freely between the two levers. Phencyclidine (PCP), scopolamine, caffeine and ethanol increased switching under the random reinforcement procedure, but (+/-)-2,5-dimethoxy-4-iodoamphetamine hydrochloride (DOI) and atropine did not. PCP, caffeine, lysergic acid diethylamide (LSD) and atropine increased switching under the FR21-switch procedure, but ethanol did not. The increases in switching produced by PCP, LSD and the anticholinergics were accompanied by marked reductions in response rate, whereas those produced by amphetamine and caffeine were not. The effects of amphetamine, and PCP were strongly dependent on the baseline probability of switching, those of atropine and caffeine moderately so, and those of LSD and ethanol only weakly so. Of the agents tested, psychomotor stimulants appear to produce the most selective increases in switching. The procedures described here may be useful for assaying the disorganisation of behaviour produced by other psychotomimetics and may have value in the detection of novel antipsychotic drugs.

SNP selection and classification of genome-wide SNP data using stratified sampling random forests.

PubMed

Wu, Qingyao; Ye, Yunming; Liu, Yang; Ng, Michael K

2012-09-01

For high dimensional genome-wide association (GWA) case-control data of complex disease, there are usually a large portion of single-nucleotide polymorphisms (SNPs) that are irrelevant with the disease. A simple random sampling method in random forest using default mtry parameter to choose feature subspace, will select too many subspaces without informative SNPs. Exhaustive searching an optimal mtry is often required in order to include useful and relevant SNPs and get rid of vast of non-informative SNPs. However, it is too time-consuming and not favorable in GWA for high-dimensional data. The main aim of this paper is to propose a stratified sampling method for feature subspace selection to generate decision trees in a random forest for GWA high-dimensional data. Our idea is to design an equal-width discretization scheme for informativeness to divide SNPs into multiple groups. In feature subspace selection, we randomly select the same number of SNPs from each group and combine them to form a subspace to generate a decision tree. The advantage of this stratified sampling procedure can make sure each subspace contains enough useful SNPs, but can avoid a very high computational cost of exhaustive search of an optimal mtry, and maintain the randomness of a random forest. We employ two genome-wide SNP data sets (Parkinson case-control data comprised of 408 803 SNPs and Alzheimer case-control data comprised of 380 157 SNPs) to demonstrate that the proposed stratified sampling method is effective, and it can generate better random forest with higher accuracy and lower error bound than those by Breiman's random forest generation method. For Parkinson data, we also show some interesting genes identified by the method, which may be associated with neurological disorders for further biological investigations.

'Chain pooling' model selection as developed for the statistical analysis of a rotor burst protection experiment

NASA Technical Reports Server (NTRS)

Holms, A. G.

1977-01-01

A statistical decision procedure called chain pooling had been developed for model selection in fitting the results of a two-level fixed-effects full or fractional factorial experiment not having replication. The basic strategy included the use of one nominal level of significance for a preliminary test and a second nominal level of significance for the final test. The subject has been reexamined from the point of view of using as many as three successive statistical model deletion procedures in fitting the results of a single experiment. The investigation consisted of random number studies intended to simulate the results of a proposed aircraft turbine-engine rotor-burst-protection experiment. As a conservative approach, population model coefficients were chosen to represent a saturated 2 to the 4th power experiment with a distribution of parameter values unfavorable to the decision procedures. Three model selection strategies were developed.

47 CFR 1.2110 - Designated entities.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection... company” as defined by the Communications Act; and (iii) The applicant (or the controlling interest... office space and/or employees and/or other facilities with another concern, particularly where such...

47 CFR 1.2110 - Designated entities.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection... company” as defined by the Communications Act; and (iii) The applicant (or the controlling interest... office space and/or employees and/or other facilities with another concern, particularly where such...

47 CFR 1.2110 - Designated entities.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection... company” as defined by the Communications Act; and (iii) The applicant (or the controlling interest... office space and/or employees and/or other facilities with another concern, particularly where such...

47 CFR 1.1703 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Cable... control of entities holding authorizations. (b) Authorization. A written instrument issued by the FCC conveying authority to operate, for a specified period, a station in the Cable Television Relay Service. In...

47 CFR 1.1703 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Cable... control of entities holding authorizations. (b) Authorization. A written instrument issued by the FCC conveying authority to operate, for a specified period, a station in the Cable Television Relay Service. In...

47 CFR 1.1703 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Cable... control of entities holding authorizations. (b) Authorization. A written instrument issued by the FCC conveying authority to operate, for a specified period, a station in the Cable Television Relay Service. In...

47 CFR 1.931 - Application for special temporary authority.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.931 Application for special temporary authority. (a) Wireless Telecommunications Services. (1) In circumstances requiring immediate or temporary use of station in the Wireless...

47 CFR 1.931 - Application for special temporary authority.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.931 Application for special temporary authority. (a) Wireless Telecommunications Services. (1) In circumstances requiring immediate or temporary use of station in the Wireless...

47 CFR 1.931 - Application for special temporary authority.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.931 Application for special temporary authority. (a) Wireless Telecommunications Services. (1) In circumstances requiring immediate or temporary use of station in the Wireless...

47 CFR 1.2209 - Disbursement of incentive payments.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Disbursement of incentive payments. 1.2209 Section 1.2209 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Competitive Bidding Proceedings Broadcast Television Spectrum Reverse Auction § 1...

Identification of Genes Involved in Breast Cancer Metastasis by Integrating Protein-Protein Interaction Information with Expression Data.

PubMed

Tian, Xin; Xin, Mingyuan; Luo, Jian; Liu, Mingyao; Jiang, Zhenran

2017-02-01

The selection of relevant genes for breast cancer metastasis is critical for the treatment and prognosis of cancer patients. Although much effort has been devoted to the gene selection procedures by use of different statistical analysis methods or computational techniques, the interpretation of the variables in the resulting survival models has been limited so far. This article proposes a new Random Forest (RF)-based algorithm to identify important variables highly related with breast cancer metastasis, which is based on the important scores of two variable selection algorithms, including the mean decrease Gini (MDG) criteria of Random Forest and the GeneRank algorithm with protein-protein interaction (PPI) information. The new gene selection algorithm can be called PPIRF. The improved prediction accuracy fully illustrated the reliability and high interpretability of gene list selected by the PPIRF approach.

THE SOCIAL PROBLEMS OF MIGRANT FARM LABORERS--EFFECT OF MIGRANT FARM LABOR ON THE EDUCATION OF CHILDREN.

ERIC Educational Resources Information Center

BROOKS, MELVIN S.; HILGENDORF, ROBERT L.

MIGRANT LABORERS WHO PICKED STRAWBERRIES IN SOUTHERN ILLINOIS IN THE SPRING OF 1958 WERE SURVEYED. THIS PARTICULAR SAMPLE WAS SELECTED FOR STUDY BECAUSE FAR MORE CHILDREN ARE INVOLVED IN THE HARVEST OF STRAWBERRIES THAN IN ANY OTHER FARM TASK OF THE AREA. MIGRANTS WHO WERE INTERVIEWED WERE SELECTED BY SYSTEMATIC RANDOM SAMPLING--A PROCEDURE THAT…

Application and testing of a procedure to evaluate transferability of habitat suitability criteria

USGS Publications Warehouse

Thomas, Jeff A.; Bovee, Ken D.

1993-01-01

A procedure designed to test the transferability of habitat suitability criteria was evaluated in the Cache la Poudre River, Colorado. Habitat suitability criteria were developed for active adult and juvenile rainbow trout in the South Platte River, Colorado. These criteria were tested by comparing microhabitat use predicted from the criteria with observed microhabitat use by adult rainbow trout in the Cache la Poudre River. A one-sided X2 test, using counts of occupied and unoccupied cells in each suitability classification, was used to test for non-random selection for optimum habitat use over usable habitat and for suitable over unsuitable habitat. Criteria for adult rainbow trout were judged to be transferable to the Cache la Poudre River, but juvenile criteria (applied to adults) were not transferable. Random subsampling of occupied and unoccupied cells was conducted to determine the effect of sample size on the reliability of the test procedure. The incidence of type I and type II errors increased rapidly as the sample size was reduced below 55 occupied and 200 unoccupied cells. Recommended modifications to the procedure included the adoption of a systematic or randomized sampling design and direct measurement of microhabitat variables. With these modifications, the procedure is economical, simple and reliable. Use of the procedure as a quality assurance device in routine applications of the instream flow incremental methodology was encouraged.

Comparison of properties of fresh and hardened concrete in bridge decks.

DOT National Transportation Integrated Search

1971-01-01

A study was made on 17 bridge decks constructed in 1963 under regular construction procedures. The purpose was (1) to compare important properties of concrete as freshly placed in randomly selected bridge decks with those after hardening of the concr...

47 CFR 1.935 - Agreements to dismiss applications, amendments or pleadings.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Agreements to dismiss applications, amendments or pleadings. 1.935 Section 1.935 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings...

47 CFR 1.935 - Agreements to dismiss applications, amendments or pleadings.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Agreements to dismiss applications, amendments or pleadings. 1.935 Section 1.935 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings...

47 CFR 1.935 - Agreements to dismiss applications, amendments or pleadings.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Agreements to dismiss applications, amendments or pleadings. 1.935 Section 1.935 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings...

47 CFR 1.2208 - Public notice of auction completion and auction results.

Code of Federal Regulations, 2014 CFR

2014-10-01

... PROCEDURE Grants by Random Selection Competitive Bidding Proceedings Broadcast Television Spectrum Reverse... broadcast television spectrum incentive auction conducted under section 6403 of the Spectrum Act, public... indicate that the reassignments of television channels and reallocations of broadcast television spectrum...

47 CFR 1.10001 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... stamps your payment as received. Pay by online credit card (through IBFS) The date your online credit... Proposed Frequencies in the United States officially filed the moment you file them through IBFS. The... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection...

47 CFR 1.10001 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... stamps your payment as received. Pay by online credit card (through IBFS) The date your online credit... Proposed Frequencies in the United States officially filed the moment you file them through IBFS. The... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection...

47 CFR 1.10001 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... stamps your payment as received. Pay by online credit card (through IBFS) The date your online credit... Proposed Frequencies in the United States officially filed the moment you file them through IBFS. The... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection...

A sampling design framework for monitoring secretive marshbirds

USGS Publications Warehouse

Johnson, D.H.; Gibbs, J.P.; Herzog, M.; Lor, S.; Niemuth, N.D.; Ribic, C.A.; Seamans, M.; Shaffer, T.L.; Shriver, W.G.; Stehman, S.V.; Thompson, W.L.

2009-01-01

A framework for a sampling plan for monitoring marshbird populations in the contiguous 48 states is proposed here. The sampling universe is the breeding habitat (i.e. wetlands) potentially used by marshbirds. Selection protocols would be implemented within each of large geographical strata, such as Bird Conservation Regions. Site selection will be done using a two-stage cluster sample. Primary sampling units (PSUs) would be land areas, such as legal townships, and would be selected by a procedure such as systematic sampling. Secondary sampling units (SSUs) will be wetlands or portions of wetlands in the PSUs. SSUs will be selected by a randomized spatially balanced procedure. For analysis, the use of a variety of methods as a means of increasing confidence in conclusions that may be reached is encouraged. Additional effort will be required to work out details and implement the plan.

Colorectal Adenomas in Participants of the SELECT Randomized Trial of Selenium and Vitamin E for Prostate Cancer Prevention

PubMed Central

Lance, Peter; Alberts, David S.; Thompson, Patricia A.; Fales, Liane; Wang, Fang; Jose, Jerilyn San; Jacobs, Elizabeth T.; Goodman, Phyllis J.; Darke, Amy K.; Yee, Monica; Minasian, Lori; Thompson, Ian M.; Roe, Denise J.

2017-01-01

Selenium and vitamin E micronutrients have been advocated for the prevention of colorectal cancer. Colorectal adenoma occurrence was used as a surrogate for colorectal cancer in an ancillary study to the Selenium and Vitamin E Cancer Prevention Trial (SELECT) for prostate cancer prevention. The primary objective was to measure the effect of selenium (as selenomethionine) on colorectal adenomas occurrence, with the effect of vitamin E (as alpha tocopherol) supplementation on colorectal adenoma occurrence considered as a secondary objective. Participants who underwent lower endoscopy while in SELECT were identified from a subgroup of the 35,533 men randomized in the trial. Adenoma occurrence was ascertained from the endoscopy and pathology reports for these procedures. Relative risk (RR) estimates and 95% confidence intervals (CI) of adenoma occurrence were generated comparing those randomized to selenium versus placebo and to vitamin E versus placebo based on the full factorial design. Evaluable endoscopy information was obtained for 6,546 participants, of whom 2,286 had 1+ adenomas. Apart from 21 flexible sigmoidoscopies, all the procedures yielding adenomas were colonoscopies. Adenomas occurred in 34.2% and 35.7%, respectively, of participants whose intervention included or did not include selenium. Compared with placebo, the RR for adenoma occurrence in participants randomized to selenium was 0.96 (95% CI, 0.90–1.02; P = 0.194). Vitamin E did not affect adenoma occurrence compared to placebo (RR = 1.03, 95% CI, 0.96–1.10; P = 0.38). Neither selenium nor vitamin E supplementation can be recommended for colorectal adenoma prevention. PMID:27777235

Students' perceived experience of university admission based on tests and interviews.

PubMed

Röding, K; Nordenram, G

2005-11-01

The aim of the study was to generate an impression, from the perspective of graduating dental students, of the individualised admissions procedures, which they had undergone 5 years before. The subjects comprised 10 randomly selected students, five male and five female, from two different admission rounds. Qualitative research was used and data were collected by means of semi-structured interviews. The results show that even 5 years later, the students remember clearly the different steps in the selection procedure and they found the procedure relevant. In particular, the admission interviews made a lasting impression. The students consider that being interviewed by one admissions committee member at a time reduces the applicant's apprehension and allows a more personal interview. Several believe that the admissions procedure influences academic achievement or improves self-confidence: implicit in their selection by a committee of experienced professionals is affirmation that they have the potential to become good dentists. The students therefore feel encouraged to aspire to higher achievement. All students believe that motivation is an important non-cognitive attribute for success and that students selected through this mode are not only highly motivated but also well informed, with realistic expectations of the undergraduate programme and their future professional career.

Assessing the accuracy and stability of variable selection methods for random forest modeling in ecology.

PubMed

Fox, Eric W; Hill, Ryan A; Leibowitz, Scott G; Olsen, Anthony R; Thornbrugh, Darren J; Weber, Marc H

2017-07-01

Random forest (RF) modeling has emerged as an important statistical learning method in ecology due to its exceptional predictive performance. However, for large and complex ecological data sets, there is limited guidance on variable selection methods for RF modeling. Typically, either a preselected set of predictor variables are used or stepwise procedures are employed which iteratively remove variables according to their importance measures. This paper investigates the application of variable selection methods to RF models for predicting probable biological stream condition. Our motivating data set consists of the good/poor condition of n = 1365 stream survey sites from the 2008/2009 National Rivers and Stream Assessment, and a large set (p = 212) of landscape features from the StreamCat data set as potential predictors. We compare two types of RF models: a full variable set model with all 212 predictors and a reduced variable set model selected using a backward elimination approach. We assess model accuracy using RF's internal out-of-bag estimate, and a cross-validation procedure with validation folds external to the variable selection process. We also assess the stability of the spatial predictions generated by the RF models to changes in the number of predictors and argue that model selection needs to consider both accuracy and stability. The results suggest that RF modeling is robust to the inclusion of many variables of moderate to low importance. We found no substantial improvement in cross-validated accuracy as a result of variable reduction. Moreover, the backward elimination procedure tended to select too few variables and exhibited numerous issues such as upwardly biased out-of-bag accuracy estimates and instabilities in the spatial predictions. We use simulations to further support and generalize results from the analysis of real data. A main purpose of this work is to elucidate issues of model selection bias and instability to ecologists interested in using RF to develop predictive models with large environmental data sets.

47 CFR 1.902 - Scope.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Scope. 1.902 Section 1.902 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Scope and Authority § 1.902 Scope. In case of any conflict between...

47 CFR 1.902 - Scope.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Scope. 1.902 Section 1.902 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Scope and Authority § 1.902 Scope. In case of any conflict between...

47 CFR 1.902 - Scope.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Scope. 1.902 Section 1.902 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Scope and Authority § 1.902 Scope. In case of any conflict between...

Determining Consumer Preference for Furniture Product Characteristics

ERIC Educational Resources Information Center

Turner, Carolyn S.; Edwards, Kay P.

1974-01-01

The paper describes instruments for determining preferences of consumers for selected product characteristics associated with furniture choices--specifically style, color, color scheme, texture, and materials--and the procedures for administration of those instruments. Results are based on a random sampling of public housing residents. (Author/MW)

47 CFR 1.2001 - Purpose.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Purpose. 1.2001 Section 1.2001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Implementation of the Anti-Drug Abuse Act of 1988 § 1.2001 Purpose. To determine eligibility for professional and...

47 CFR 1.2001 - Purpose.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Purpose. 1.2001 Section 1.2001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Implementation of the Anti-Drug Abuse Act of 1988 § 1.2001 Purpose. To determine eligibility for professional and...

47 CFR 1.2001 - Purpose.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Purpose. 1.2001 Section 1.2001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Implementation of the Anti-Drug Abuse Act of 1988 § 1.2001 Purpose. To determine eligibility for professional and...

Resampling procedures to identify important SNPs using a consensus approach.

PubMed

Pardy, Christopher; Motyer, Allan; Wilson, Susan

2011-11-29

Our goal is to identify common single-nucleotide polymorphisms (SNPs) (minor allele frequency > 1%) that add predictive accuracy above that gained by knowledge of easily measured clinical variables. We take an algorithmic approach to predict each phenotypic variable using a combination of phenotypic and genotypic predictors. We perform our procedure on the first simulated replicate and then validate against the others. Our procedure performs well when predicting Q1 but is less successful for the other outcomes. We use resampling procedures where possible to guard against false positives and to improve generalizability. The approach is based on finding a consensus regarding important SNPs by applying random forests and the least absolute shrinkage and selection operator (LASSO) on multiple subsamples. Random forests are used first to discard unimportant predictors, narrowing our focus to roughly 100 important SNPs. A cross-validation LASSO is then used to further select variables. We combine these procedures to guarantee that cross-validation can be used to choose a shrinkage parameter for the LASSO. If the clinical variables were unavailable, this prefiltering step would be essential. We perform the SNP-based analyses simultaneously rather than one at a time to estimate SNP effects in the presence of other causal variants. We analyzed the first simulated replicate of Genetic Analysis Workshop 17 without knowledge of the true model. Post-conference knowledge of the simulation parameters allowed us to investigate the limitations of our approach. We found that many of the false positives we identified were substantially correlated with genuine causal SNPs.

47 CFR 90.165 - Procedures for mutually exclusive applications.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., the Commission may use competitive bidding, random selection, or comparative hearings, depending on... exclusive applications in a renewal filing group are designated for comparative consideration in a hearing... applications in the filing group for comparative consideration in a hearing. In this event, the result of the...

47 CFR 90.165 - Procedures for mutually exclusive applications.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., the Commission may use competitive bidding, random selection, or comparative hearings, depending on... exclusive applications in a renewal filing group are designated for comparative consideration in a hearing... applications in the filing group for comparative consideration in a hearing. In this event, the result of the...

47 CFR 90.165 - Procedures for mutually exclusive applications.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., the Commission may use competitive bidding, random selection, or comparative hearings, depending on... exclusive applications in a renewal filing group are designated for comparative consideration in a hearing... applications in the filing group for comparative consideration in a hearing. In this event, the result of the...

47 CFR 1.913 - Application and notification forms; electronic and manual filing.

Code of Federal Regulations, 2014 CFR

2014-10-01

... PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings... Form 601, Application for Authorization in the Wireless Radio Services. FCC Form 601 and associated..., notifications, requests for extension of time, and administrative updates. (2) FCC Form 602, Wireless Radio...

47 CFR 1.925 - Waivers.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Waivers. 1.925 Section 1.925 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio... applications in the Wireless Radio Services must be filed on FCC Form 601, 603, or 605. (2) Requests for waiver...

47 CFR 1.913 - Application and notification forms; electronic and manual filing.

Code of Federal Regulations, 2013 CFR

2013-10-01

... PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings... Form 601, Application for Authorization in the Wireless Radio Services. FCC Form 601 and associated..., notifications, requests for extension of time, and administrative updates. (2) FCC Form 602, Wireless Radio...

47 CFR 1.925 - Waivers.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Waivers. 1.925 Section 1.925 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio... applications in the Wireless Radio Services must be filed on FCC Form 601, 603, or 605. (2) Requests for waiver...

47 CFR 1.925 - Waivers.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Waivers. 1.925 Section 1.925 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio... applications in the Wireless Radio Services must be filed on FCC Form 601, 603, or 605. (2) Requests for waiver...

Antibiotic resistance profiles of coagulase-positive and coagulase-negative staphylococci from pit latrine fecal sludge in a peri-urban South African community.

PubMed

Beukes, Lorika S; Schmidt, Stefan

2018-04-16

The aim of this study was to assess pit latrine samples from a peri-urban community in KwaZulu-Natal (South Africa) for the presence of multidrug-resistant (MDR) Staphylococcus spp. Standard procedures were used to isolate Staphylococcus spp. from pit latrine fecal sludge samples, with confirmation at genus level by polymerase chain reaction (PCR). Sixty-eight randomly selected pit latrine Staphylococcus spp. isolates were further characterized by using established disk diffusion procedures. An average Staphylococcus spp. count of 2.1 × 10 5  CFU per g fecal material was established using two randomly selected pit latrine samples. Of the 68-selected Staphylococcus spp. pit latrine isolates, 49% were identified as coagulase positive, 51% as coagulase negative and 65% (12 coagulase positive, 32 coagulase negative isolates) were categorized as MDR. The majority (66/68) of Staphylococcus spp. isolates displayed resistance to fusidic acid while only 5/68 isolates displayed resistance to chloramphenicol. The pit latrine samples analyzed in this study are a source of MDR Staphylococcus spp., highlighting the need for proper hygiene and sanitation regimes in rural communities using these facilities.

Variable selection in subdistribution hazard frailty models with competing risks data

PubMed Central

Do Ha, Il; Lee, Minjung; Oh, Seungyoung; Jeong, Jong-Hyeon; Sylvester, Richard; Lee, Youngjo

2014-01-01

The proportional subdistribution hazards model (i.e. Fine-Gray model) has been widely used for analyzing univariate competing risks data. Recently, this model has been extended to clustered competing risks data via frailty. To the best of our knowledge, however, there has been no literature on variable selection method for such competing risks frailty models. In this paper, we propose a simple but unified procedure via a penalized h-likelihood (HL) for variable selection of fixed effects in a general class of subdistribution hazard frailty models, in which random effects may be shared or correlated. We consider three penalty functions (LASSO, SCAD and HL) in our variable selection procedure. We show that the proposed method can be easily implemented using a slight modification to existing h-likelihood estimation approaches. Numerical studies demonstrate that the proposed procedure using the HL penalty performs well, providing a higher probability of choosing the true model than LASSO and SCAD methods without losing prediction accuracy. The usefulness of the new method is illustrated using two actual data sets from multi-center clinical trials. PMID:25042872

Required number of records for ASCE/SEI 7 ground-motion scaling procedure

USGS Publications Warehouse

Reyes, Juan C.; Kalkan, Erol

2011-01-01

The procedures and criteria in 2006 IBC (International Council of Building Officials, 2006) and 2007 CBC (International Council of Building Officials, 2007) for the selection and scaling ground-motions for use in nonlinear response history analysis (RHA) of structures are based on ASCE/SEI 7 provisions (ASCE, 2005, 2010). According to ASCE/SEI 7, earthquake records should be selected from events of magnitudes, fault distance, and source mechanisms that comply with the maximum considered earthquake, and then scaled so that the average value of the 5-percent-damped response spectra for the set of scaled records is not less than the design response spectrum over the period range from 0.2Tn to 1.5Tn sec (where Tn is the fundamental vibration period of the structure). If at least seven ground-motions are analyzed, the design values of engineering demand parameters (EDPs) are taken as the average of the EDPs determined from the analyses. If fewer than seven ground-motions are analyzed, the design values of EDPs are taken as the maximum values of the EDPs. ASCE/SEI 7 requires a minimum of three ground-motions. These limits on the number of records in the ASCE/SEI 7 procedure are based on engineering experience, rather than on a comprehensive evaluation. This study statistically examines the required number of records for the ASCE/SEI 7 procedure, such that the scaled records provide accurate, efficient, and consistent estimates of" true" structural responses. Based on elastic-perfectly-plastic and bilinear single-degree-of-freedom systems, the ASCE/SEI 7 scaling procedure is applied to 480 sets of ground-motions. The number of records in these sets varies from three to ten. The records in each set were selected either (i) randomly, (ii) considering their spectral shapes, or (iii) considering their spectral shapes and design spectral-acceleration value, A(Tn). As compared to benchmark (that is, "true") responses from unscaled records using a larger catalog of ground-motions, it is demonstrated that the ASCE/SEI 7 scaling procedure is overly conservative if fewer than seven ground-motions are employed. Utilizing seven or more randomly selected records provides a more accurate estimate of the EDPs accompanied by reduced record-to-record variability of the responses. Consistency in accuracy and efficiency is achieved only if records are selected on the basis of their spectral shape and A(Tn).

The evaluation of readiness of medical personnel to act under conditions of chemical contamination.

PubMed

Szarpak, Łukasz; Kurowski, Andrzej

2014-08-01

We evaluated the knowledge of physicians, nurses, and paramedics in Poland about the procedures in a chemical contamination. An anonymous survey was mailed to 600 randomly selected physicians, nurses, and paramedics. The survey included questions concerning the process of decontamination, knowledge of toxidromes, and the use of selected antidotes. Completed surveys were received from 510 respondents (85%). A very low level of knowledge was observed regarding decontamination techniques (from 8.3% to 34.2%), use of antidotes (from 13.7% to 61%), and knowledge of toxidromes (from 10.2% to 22.7%). Our findings showed that for all aspects of chemical rescue procedures queried, the knowledge of medical personnel was not satisfactory. Both practical and theoretical training of medical personnel is urgently needed for life-saving procedures during a chemical contamination.

40 CFR 86.1823-08 - Durability demonstration procedures for exhaust emissions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... judgement, a catalyst aging bench that follows the SBC and delivers the appropriate exhaust flow, exhaust... set must consist of randomly procured vehicles from actual customer use. The vehicles selected for... submit an analysis which evaluates whether the durability objective will be achieved for the vehicle...

47 CFR 1.1417 - Allocation of Unusable Space Costs.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Allocation of Unusable Space Costs. 1.1417... by Random Selection Pole Attachment Complaint Procedures § 1.1417 Allocation of Unusable Space Costs... providing unusable space on a pole so that such apportionment equals two-thirds of the costs of providing...

47 CFR 1.1417 - Allocation of Unusable Space Costs.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Allocation of Unusable Space Costs. 1.1417... by Random Selection Pole Attachment Complaint Procedures § 1.1417 Allocation of Unusable Space Costs... providing unusable space on a pole so that such apportionment equals two-thirds of the costs of providing...

47 CFR 1.913 - Application and notification forms; electronic and manual filing.

Code of Federal Regulations, 2012 CFR

2012-10-01

... PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings... Form 601, Application for Authorization in the Wireless Radio Services. FCC Form 601 and associated... 602, Wireless Radio Services Ownership Form. FCC Form 602 is used by applicants and licensees in...

47 CFR 1.948 - Assignment of authorization or transfer of control, notification of consummation.

Code of Federal Regulations, 2013 CFR

2013-10-01

... COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and... involuntary assignment or transfer. (d) Notification of consummation. In all Wireless Radio Services... radio station in the Wireless Radio Services is assigned to another party, voluntarily or involuntarily...

47 CFR 1.948 - Assignment of authorization or transfer of control, notification of consummation.

Code of Federal Regulations, 2014 CFR

2014-10-01

... COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and... involuntary assignment or transfer. (d) Notification of consummation. In all Wireless Radio Services... radio station in the Wireless Radio Services is assigned to another party, voluntarily or involuntarily...

47 CFR 1.948 - Assignment of authorization or transfer of control, notification of consummation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and... involuntary assignment or transfer. (d) Notification of consummation. In all Wireless Radio Services... radio station in the Wireless Radio Services is assigned to another party, voluntarily or involuntarily...

A Design Selection Procedure.

ERIC Educational Resources Information Center

Kroeker, Leonard P.

The problem of blocking on a status variable was investigated. The one-way fixed-effects analysis of variance, analysis of covariance, and generalized randomized block designs each treat the blocking problem in a different way. In order to compare these designs, it is necessary to restrict attention to experimental situations in which observations…

47 CFR 1.1417 - Allocation of Unusable Space Costs.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false Allocation of Unusable Space Costs. 1.1417... by Random Selection Pole Attachment Complaint Procedures § 1.1417 Allocation of Unusable Space Costs... providing unusable space on a pole so that such apportionment equals two-thirds of the costs of providing...

47 CFR 1.10012 - When can I file on IBFS?

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false When can I file on IBFS? 1.10012 Section 1.10012 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection International Bureau Filing System § 1.10012 When can I file on IBFS? IBFS is available...

47 CFR 1.10012 - When can I file on IBFS?

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false When can I file on IBFS? 1.10012 Section 1.10012 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection International Bureau Filing System § 1.10012 When can I file on IBFS? IBFS is available...

Conducting a wildland visual resources inventory

Treesearch

James F. Palmer

1979-01-01

This paper describes a procedure for systematically inventorying the visual resources of wildland environments. Visual attributes are recorded photographically using two separate sampling methods: one based on professional judgment and the other on random selection. The location and description of each inventoried scene are recorded on U.S. Geological Survey...

Colorectal Adenomas in Participants of the SELECT Randomized Trial of Selenium and Vitamin E for Prostate Cancer Prevention.

PubMed

Lance, Peter; Alberts, David S; Thompson, Patricia A; Fales, Liane; Wang, Fang; San Jose, Jerilyn; Jacobs, Elizabeth T; Goodman, Phyllis J; Darke, Amy K; Yee, Monica; Minasian, Lori; Thompson, Ian M; Roe, Denise J

2017-01-01

Selenium and vitamin E micronutrients have been advocated for the prevention of colorectal cancer. Colorectal adenoma occurrence was used as a surrogate for colorectal cancer in an ancillary study to the Selenium and Vitamin E Cancer Prevention Trial (SELECT) for prostate cancer prevention. The primary objective was to measure the effect of selenium (as selenomethionine) on colorectal adenomas occurrence, with the effect of vitamin E (as α-tocopherol) supplementation on colorectal adenoma occurrence considered as a secondary objective. Participants who underwent lower endoscopy while in SELECT were identified from a subgroup of the 35,533 men randomized in the trial. Adenoma occurrence was ascertained from the endoscopy and pathology reports for these procedures. Relative Risk (RR) estimates and 95% confidence intervals (CI) of adenoma occurrence were generated comparing those randomized to selenium versus placebo and to vitamin E versus placebo based on the full factorial design. Evaluable endoscopy information was obtained for 6,546 participants, of whom 2,286 had 1+ adenomas. Apart from 21 flexible sigmoidoscopies, all the procedures yielding adenomas were colonoscopies. Adenomas occurred in 34.2% and 35.7%, respectively, of participants whose intervention included or did not include selenium. Compared with placebo, the RR for adenoma occurrence in participants randomized to selenium was 0.96 (95% CI, 0.90-1.02; P = 0.194). Vitamin E did not affect adenoma occurrence compared with placebo (RR = 1.03; 95% CI, 0.96-1.10; P = 0.38). Neither selenium nor vitamin E supplementation can be recommended for colorectal adenoma prevention. Cancer Prev Res; 10(1); 45-54. ©2016 AACR. ©2016 American Association for Cancer Research.

Adaptive pre-specification in randomized trials with and without pair-matching.

PubMed

Balzer, Laura B; van der Laan, Mark J; Petersen, Maya L

2016-11-10

In randomized trials, adjustment for measured covariates during the analysis can reduce variance and increase power. To avoid misleading inference, the analysis plan must be pre-specified. However, it is often unclear a priori which baseline covariates (if any) should be adjusted for in the analysis. Consider, for example, the Sustainable East Africa Research in Community Health (SEARCH) trial for HIV prevention and treatment. There are 16 matched pairs of communities and many potential adjustment variables, including region, HIV prevalence, male circumcision coverage, and measures of community-level viral load. In this paper, we propose a rigorous procedure to data-adaptively select the adjustment set, which maximizes the efficiency of the analysis. Specifically, we use cross-validation to select from a pre-specified library the candidate targeted maximum likelihood estimator (TMLE) that minimizes the estimated variance. For further gains in precision, we also propose a collaborative procedure for estimating the known exposure mechanism. Our small sample simulations demonstrate the promise of the methodology to maximize study power, while maintaining nominal confidence interval coverage. We show how our procedure can be tailored to the scientific question (intervention effect for the study sample vs. for the target population) and study design (pair-matched or not). Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Covariate Selection for Multilevel Models with Missing Data

PubMed Central

Marino, Miguel; Buxton, Orfeu M.; Li, Yi

2017-01-01

Missing covariate data hampers variable selection in multilevel regression settings. Current variable selection techniques for multiply-imputed data commonly address missingness in the predictors through list-wise deletion and stepwise-selection methods which are problematic. Moreover, most variable selection methods are developed for independent linear regression models and do not accommodate multilevel mixed effects regression models with incomplete covariate data. We develop a novel methodology that is able to perform covariate selection across multiply-imputed data for multilevel random effects models when missing data is present. Specifically, we propose to stack the multiply-imputed data sets from a multiple imputation procedure and to apply a group variable selection procedure through group lasso regularization to assess the overall impact of each predictor on the outcome across the imputed data sets. Simulations confirm the advantageous performance of the proposed method compared with the competing methods. We applied the method to reanalyze the Healthy Directions-Small Business cancer prevention study, which evaluated a behavioral intervention program targeting multiple risk-related behaviors in a working-class, multi-ethnic population. PMID:28239457

Treatment of Implant Exposure due to Skin Necroses after Skin Sparing Mastectomy: Initial Experiences Using a Not Selective Random Epigastric Flap.

PubMed

Echazarreta-Gallego, Estíbaliz; Pola-Bandrés, Guillermo; Arribas-Del Amo, María Dolores; Gil-Romea, Ismael; Sousa-Domínguez, Ramón; Güemes-Sánchez, Antonio

2017-10-01

Breast prostheses exposure is probably the most devastating complication after a skin sparing mastectomy (SSM) and implant-based, one-stage, breast reconstruction. This complication may occur in the immediate post-operative period or in the weeks and even months after the procedure. In most cases, the cause is poor skin coverage of the implant due to skin necrosis. Eight consecutive cases of implant exposure (or risk of exposure) due to skin necrosis in SSM patients over a period of 5 years, all patients were treated using a random epigastric rotation flap, executed by the same medical team. A random epigastric flap (island or conventional rotation flap) was used to cover the skin defect. All the patients completed the procedure and all prostheses were saved; there were no cases of flap necrosis or infection. Cases of skin necrosis after SSM and immediate implant reconstruction, in which the implant is at risk of exposure, can be successfully treated with a random epigastric rotation flap.

Digital transcriptome profiling using selective hexamer priming for cDNA synthesis.

PubMed

Armour, Christopher D; Castle, John C; Chen, Ronghua; Babak, Tomas; Loerch, Patrick; Jackson, Stuart; Shah, Jyoti K; Dey, John; Rohl, Carol A; Johnson, Jason M; Raymond, Christopher K

2009-09-01

We developed a procedure for the preparation of whole transcriptome cDNA libraries depleted of ribosomal RNA from only 1 microg of total RNA. The method relies on a collection of short, computationally selected oligonucleotides, called 'not-so-random' (NSR) primers, to obtain full-length, strand-specific representation of nonribosomal RNA transcripts. In this study we validated the technique by profiling human whole brain and universal human reference RNA using ultra-high-throughput sequencing.

The effect of self-selected soothing music on fistula puncture-related pain in hemodialysis patients.

PubMed

Shabandokht-Zarmi, Hosniyeh; Bagheri-Nesami, Masoumeh; Shorofi, Seyed Afshin; Mousavinasab, Seyed Nouraddin

2017-11-01

This study was intended to examine the effect of selective soothing music on fistula puncture-related pain in hemodialysis patients. This is a randomized clinical trial in which 114 participants were selected from two hemodialysis units by means of a non-random, convenience sampling method. The participants were then allocated in three groups of music (N = 38), headphone (N = 38), and control (N = 38). The fistula puncture-related pain was measured 1 min after venipuncture procedure in all three groups. The music group listened to their self-selected and preferred music 6 min before needle insertion into a fistula until the end of procedure. The headphone group wore a headphone alone without listening to music 6 min before needle insertion into a fistula until the end of procedure. The control group did not receive any intervention from the research team during needle insertion into a fistula. The pain intensity was measured immediately after the intervention in all three groups. This study showed a significant difference between the music and control groups, and the music and headphone groups in terms of the mean pain score after the intervention. However, the analysis did not indicate any significant difference between the headphone and control groups with regard to the mean pain score after the intervention. It is concluded that music can be used effectively for pain related to needle insertion into a fistula in hemodialysis patients. Future research should investigate the comparative effects of pharmacological and non-pharmacological interventions on fistula puncture-related pain. Copyright © 2017 Elsevier Ltd. All rights reserved.

42 CFR 416.140 - Surveys.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 3 2014-10-01 2014-10-01 false Surveys. 416.140 Section 416.140 Public Health... Furnished Before January 1, 2008 § 416.140 Surveys. (a) Timing, purpose, and procedures. (1) No more often than once a year, CMS conducts a survey of a randomly selected sample of participating ASCs to collect...

42 CFR 416.140 - Surveys.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 3 2011-10-01 2011-10-01 false Surveys. 416.140 Section 416.140 Public Health... January 1, 2008 § 416.140 Surveys. (a) Timing, purpose, and procedures. (1) No more often than once a year, CMS conducts a survey of a randomly selected sample of participating ASCs to collect data for analysis...

42 CFR 416.140 - Surveys.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 3 2013-10-01 2013-10-01 false Surveys. 416.140 Section 416.140 Public Health... Furnished Before January 1, 2008 § 416.140 Surveys. (a) Timing, purpose, and procedures. (1) No more often than once a year, CMS conducts a survey of a randomly selected sample of participating ASCs to collect...

42 CFR 416.140 - Surveys.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 3 2012-10-01 2012-10-01 false Surveys. 416.140 Section 416.140 Public Health... Furnished Before January 1, 2008 § 416.140 Surveys. (a) Timing, purpose, and procedures. (1) No more often than once a year, CMS conducts a survey of a randomly selected sample of participating ASCs to collect...

42 CFR 416.140 - Surveys.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 3 2010-10-01 2010-10-01 false Surveys. 416.140 Section 416.140 Public Health... January 1, 2008 § 416.140 Surveys. (a) Timing, purpose, and procedures. (1) No more often than once a year, CMS conducts a survey of a randomly selected sample of participating ASCs to collect data for analysis...

Anemia, micronutrient deficiencies, and malaria in children and women in Sierra Leone prior to the Ebola outbreak

USDA-ARS?s Scientific Manuscript database

To identify the factors associated with anemia and to document the severity of micronutrient deficiencies, malaria and inflammation, a nationally representative cross-sectional survey was conducted. A three-stage sampling procedure was used to randomly select children <5 years of age and adult women...

Questioning: A Reading/Thinking Foundation for the Gifted.

ERIC Educational Resources Information Center

Batson, Amanda Davis

A study to determine the effects of higher level interactive questioning procedures on the cognitive abilities of gifted students was conducted with 14 gifted sixth grade students. The students were selected from a public school enrichment program and randomly assigned to one of two groups that met for five weekly sessions. The control group was…

The impact of system level factors on treatment timeliness: utilizing the Toyota Production System to implement direct intake scheduling in a semi-rural community mental health clinic.

PubMed

Weaver, Addie; Greeno, Catherine G; Goughler, Donald H; Yarzebinski, Kathleen; Zimmerman, Tina; Anderson, Carol

2013-07-01

This study examined the effect of using the Toyota Production System (TPS) to change intake procedures on treatment timeliness within a semi-rural community mental health clinic. One hundred randomly selected cases opened the year before the change and 100 randomly selected cases opened the year after the change were reviewed. An analysis of covariance demonstrated that changing intake procedures significantly decreased the number of days consumers waited for appointments (F(1,160) = 4.9; p = .03) from an average of 11 to 8 days. The pattern of difference on treatment timeliness was significantly different between adult and child programs (F(1,160) = 4.2; p = .04), with children waiting an average of 4 days longer than adults for appointments. Findings suggest that small system level changes may elicit important changes and that TPS offers a valuable model to improve processes within community mental health settings. Results also indicate that different factors drive adult and children's treatment timeliness.

The Impact of System Level Factors on Treatment Timeliness: Utilizing the Toyota Production System to Implement Direct Intake Scheduling in a Semi-Rural Community Mental Health Clinic

PubMed Central

Weaver, A.; Greeno, C.G.; Goughler, D.H.; Yarzebinski, K.; Zimmerman, T.; Anderson, C.

2013-01-01

This study examined the effect of using the Toyota Production System (TPS) to change intake procedures on treatment timeliness within a semi-rural community mental health clinic. One hundred randomly selected cases opened the year before the change and one hundred randomly selected cases opened the year after the change were reviewed. An analysis of covariance (ANCOVA) demonstrated that changing intake procedures significantly decreased the number of days consumers waited for appointments (F(1,160)=4.9; p=.03) from an average of 11 days to 8 days. The pattern of difference on treatment timeliness was significantly different between adult and child programs (F(1,160)=4.2; p=.04), with children waiting an average of 4 days longer than adults for appointments. Findings suggest that small system level changes may elicit important changes and that TPS offers a valuable model to improve processes within community mental health settings. Results also indicate that different factors drive adult and children’s treatment timeliness. PMID:23576137

The applications of regenerative medicine in sinus lift procedures: A systematic review.

PubMed

Correia, Francisco; Pozza, Daniel Humberto; Gouveia, Sónia; Felino, António; Faria E Almeida, Ricardo

2018-04-01

Findings in regenerative medicine applied to the sinus lift procedures. Evaluate the effectiveness of regenerative medicine in sinus lift. An extensive search for manuscripts were performed by using different combinations of keywords and MeSH terms (Pub-med; Embase; Scopus; Web of Science Core Collection; Medline; Current Contents Connect; Derwent Innovations Index; Scielo Citation Index; Cochrane library). The full text selected articles are written in English, Portuguese, Spanish, Italian, German, or French, and published until 28 of November 2016. Inclusion criteria were: implant osteointegration, radiographic, histologic, and/or histomorphometric analysis, clinical studies in humans using of regenerative medicine. This systematic review was performed by selecting only randomized controlled clinical trials and controlled clinical trials. Eighteen published studies (11 CT and 7 RCT) were considered eligible for inclusion in the present systematic review. These studies demonstrated considerable variation of biomaterial and cell technics used, study design, sinus lift technic, outcomes, follow-up, and results. Only few studies have demonstrated potential of regenerative medicine in sinus lift; further randomized clinical trials are needed to achieve more accurate results. © 2017 Wiley Periodicals, Inc.

A multiscale Markov random field model in wavelet domain for image segmentation

NASA Astrophysics Data System (ADS)

Dai, Peng; Cheng, Yu; Wang, Shengchun; Du, Xinyu; Wu, Dan

2017-07-01

The human vision system has abilities for feature detection, learning and selective attention with some properties of hierarchy and bidirectional connection in the form of neural population. In this paper, a multiscale Markov random field model in the wavelet domain is proposed by mimicking some image processing functions of vision system. For an input scene, our model provides its sparse representations using wavelet transforms and extracts its topological organization using MRF. In addition, the hierarchy property of vision system is simulated using a pyramid framework in our model. There are two information flows in our model, i.e., a bottom-up procedure to extract input features and a top-down procedure to provide feedback controls. The two procedures are controlled simply by two pyramidal parameters, and some Gestalt laws are also integrated implicitly. Equipped with such biological inspired properties, our model can be used to accomplish different image segmentation tasks, such as edge detection and region segmentation.

Comparative evaluation of stress levels before, during, and after periodontal surgical procedures with and without nitrous oxide-oxygen inhalation sedation.

PubMed

Sandhu, Gurkirat; Khinda, Paramjit Kaur; Gill, Amarjit Singh; Singh Khinda, Vineet Inder; Baghi, Kamal; Chahal, Gurparkash Singh

2017-01-01

Periodontal surgical procedures produce varying degree of stress in all patients. Nitrous oxide-oxygen inhalation sedation is very effective for adult patients with mild-to-moderate anxiety due to dental procedures and needle phobia. The present study was designed to perform periodontal surgical procedures under nitrous oxide-oxygen inhalation sedation and assess whether this technique actually reduces stress physiologically, in comparison to local anesthesia alone (LA) during lengthy periodontal surgical procedures. This was a randomized, split-mouth, cross-over study. A total of 16 patients were selected for this randomized, split-mouth, cross-over study. One surgical session (SS) was performed under local anesthesia aided by nitrous oxide-oxygen inhalation sedation, and the other SS was performed on the contralateral quadrant under LA. For each session, blood samples to measure and evaluate serum cortisol levels were obtained, and vital parameters including blood pressure, heart rate, respiratory rate, and arterial blood oxygen saturation were monitored before, during, and after periodontal surgical procedures. Paired t -test and repeated measure ANOVA. The findings of the present study revealed a statistically significant decrease in serum cortisol levels, blood pressure and pulse rate and a statistically significant increase in respiratory rate and arterial blood oxygen saturation during periodontal surgical procedures under nitrous oxide inhalation sedation. Nitrous oxide-oxygen inhalation sedation for periodontal surgical procedures is capable of reducing stress physiologically, in comparison to LA during lengthy periodontal surgical procedures.

Endoscopic and laparoscopic treatment of gastroesophageal reflux.

PubMed

Watson, David I; Immanuel, Arul

2010-04-01

Gastroesophageal reflux is extremely common in Western countries. For selected patients, there is an established role for the surgical treatment of reflux, and possibly an emerging role for endoscopic antireflux procedures. Randomized trials have compared medical versus surgical management, laparoscopic versus open surgery and partial versus total fundoplications. However, the evidence base for endoscopic procedures is limited to some small sham-controlled studies, and cohort studies with short-term follow-up. Laparoscopic fundoplication has been shown to be an effective antireflux operation. It facilitates quicker convalescence and is associated with fewer complications, but has a similar longer term outcome compared with open antireflux surgery. In most randomized trials, antireflux surgery achieves at least as good control of reflux as medical therapy, and these studies support a wider application of surgery for the treatment of moderate-to-severe reflux. Laparoscopic partial fundoplication is an effective surgical procedure with fewer side effects, and it may achieve high rates of patient satisfaction at late follow-up. Many of the early endoscopic antireflux procedures have failed to achieve effective reflux control, and they have been withdrawn from the market. Newer procedures have the potential to fashion a surgical fundoplication. However, at present there is insufficient evidence to establish the safety and efficacy of endoscopic procedures for the treatment of gastroesophageal reflux, and no endoscopic procedure has achieved equivalent reflux control to that achieved by surgical fundoplication.

Sampling in health geography: reconciling geographical objectives and probabilistic methods. An example of a health survey in Vientiane (Lao PDR)

PubMed Central

Vallée, Julie; Souris, Marc; Fournet, Florence; Bochaton, Audrey; Mobillion, Virginie; Peyronnie, Karine; Salem, Gérard

2007-01-01

Background Geographical objectives and probabilistic methods are difficult to reconcile in a unique health survey. Probabilistic methods focus on individuals to provide estimates of a variable's prevalence with a certain precision, while geographical approaches emphasise the selection of specific areas to study interactions between spatial characteristics and health outcomes. A sample selected from a small number of specific areas creates statistical challenges: the observations are not independent at the local level, and this results in poor statistical validity at the global level. Therefore, it is difficult to construct a sample that is appropriate for both geographical and probability methods. Methods We used a two-stage selection procedure with a first non-random stage of selection of clusters. Instead of randomly selecting clusters, we deliberately chose a group of clusters, which as a whole would contain all the variation in health measures in the population. As there was no health information available before the survey, we selected a priori determinants that can influence the spatial homogeneity of the health characteristics. This method yields a distribution of variables in the sample that closely resembles that in the overall population, something that cannot be guaranteed with randomly-selected clusters, especially if the number of selected clusters is small. In this way, we were able to survey specific areas while minimising design effects and maximising statistical precision. Application We applied this strategy in a health survey carried out in Vientiane, Lao People's Democratic Republic. We selected well-known health determinants with unequal spatial distribution within the city: nationality and literacy. We deliberately selected a combination of clusters whose distribution of nationality and literacy is similar to the distribution in the general population. Conclusion This paper describes the conceptual reasoning behind the construction of the survey sample and shows that it can be advantageous to choose clusters using reasoned hypotheses, based on both probability and geographical approaches, in contrast to a conventional, random cluster selection strategy. PMID:17543100

Sampling in health geography: reconciling geographical objectives and probabilistic methods. An example of a health survey in Vientiane (Lao PDR).

PubMed

Vallée, Julie; Souris, Marc; Fournet, Florence; Bochaton, Audrey; Mobillion, Virginie; Peyronnie, Karine; Salem, Gérard

2007-06-01

Geographical objectives and probabilistic methods are difficult to reconcile in a unique health survey. Probabilistic methods focus on individuals to provide estimates of a variable's prevalence with a certain precision, while geographical approaches emphasise the selection of specific areas to study interactions between spatial characteristics and health outcomes. A sample selected from a small number of specific areas creates statistical challenges: the observations are not independent at the local level, and this results in poor statistical validity at the global level. Therefore, it is difficult to construct a sample that is appropriate for both geographical and probability methods. We used a two-stage selection procedure with a first non-random stage of selection of clusters. Instead of randomly selecting clusters, we deliberately chose a group of clusters, which as a whole would contain all the variation in health measures in the population. As there was no health information available before the survey, we selected a priori determinants that can influence the spatial homogeneity of the health characteristics. This method yields a distribution of variables in the sample that closely resembles that in the overall population, something that cannot be guaranteed with randomly-selected clusters, especially if the number of selected clusters is small. In this way, we were able to survey specific areas while minimising design effects and maximising statistical precision. We applied this strategy in a health survey carried out in Vientiane, Lao People's Democratic Republic. We selected well-known health determinants with unequal spatial distribution within the city: nationality and literacy. We deliberately selected a combination of clusters whose distribution of nationality and literacy is similar to the distribution in the general population. This paper describes the conceptual reasoning behind the construction of the survey sample and shows that it can be advantageous to choose clusters using reasoned hypotheses, based on both probability and geographical approaches, in contrast to a conventional, random cluster selection strategy.

Jackknifing Techniques for Evaluation of Equating Accuracy. Research Report. ETS RR-09-39

ERIC Educational Resources Information Center

Haberman, Shelby J.; Lee, Yi-Hsuan; Qian, Jiahe

2009-01-01

Grouped jackknifing may be used to evaluate the stability of equating procedures with respect to sampling error and with respect to changes in anchor selection. Properties of grouped jackknifing are reviewed for simple-random and stratified sampling, and its use is described for comparisons of anchor sets. Application is made to examples of item…

Intra-Group Motivational Analysis of Students with Learning Disabilities: A Goal Orientation Approach

ERIC Educational Resources Information Center

Sideris, Georgios D.; Tsorbatzoudis, Charalambos

2003-01-01

The purpose of the present study was to profile, using a K-means cluster analysis, the cognitive, motivational, affective, and goal orientation characteristics of elementary school students with and without learning disabilities (LD). Participants were 58 fifth and 6 sixth graders (29 typical and 29 LD) selected using stratified random procedures.…

The Cloze Procedure: A Measure for Determining Readability Level for Vocational Junior College Students.

ERIC Educational Resources Information Center

Caffey, Musa B.

One hundred students enrolled in the welding and air-conditioning/refrigeration classes at Delgado Community College (Louisiana) were randomly selected to participate in a study to evaluate their effective reading comprehension level, to investigate the impact of a study skill "preview" method such as the SQ3R on their test-taking…

Texas School Survey of Substance Abuse: Grades 7-12. 1992.

ERIC Educational Resources Information Center

Liu, Liang Y.; Fredlund, Eric V.

The 1992 Texas School Survey results for secondary students are based on data collected from a sample of 73,073 students in grades 7 through 12. Students were randomly selected from school districts throughout the state using a multi-stage probability design. The procedure ensured that students living in metropolitan and rural areas of Texas are…

47 CFR 1.991 - Contents of petitions for declaratory ruling under the Communications Act of 1934.

Code of Federal Regulations, 2014 CFR

2014-10-01

... COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and... assignment or transfer of control, specify for each named applicant: (i) The File No(s). of the associated... consist of the following rights: (i) The power to prevent the sale or pledge of all or substantially all...

47 CFR 1.991 - Contents of petitions for declaratory ruling under the Communications Act of 1934.

Code of Federal Regulations, 2013 CFR

2013-10-01

... COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and... assignment or transfer of control, specify for each named applicant: (i) The File No(s). of the associated... consist of the following rights: (i) The power to prevent the sale or pledge of all or substantially all...

A Behaviorally-Anchored Rating System to Monitor Treatment Integrity for Community Clinicians Using the Adolescent Community Reinforcement Approach

ERIC Educational Resources Information Center

Smith, Jane Ellen; Gianini, Loren M.; Garner, Bryan R.; Malek, Karen L.; Godley, Susan H.

2014-01-01

This study evaluated a process for training raters to reliably rate clinicians delivering the Adolescent Community Reinforcement Approach (A-CRA) in a national dissemination project. The unique A-CRA coding system uses specific behavioral anchors throughout its 73 procedure components. Five randomly selected raters each rated "passing"…

Tooth movements in foxhounds after one or two alveolar corticotomies.

PubMed

Sanjideh, Payam A; Rossouw, P Emile; Campbell, Phillip M; Opperman, Lynne A; Buschang, Peter H

2010-02-01

The aim of this split-mouth experimental study was to determine (1) whether corticotomy procedures increase tooth movement and (2) the effects of a second corticotomy procedure after 4 weeks on the rate of tooth movement. The mandibular third and maxillary second premolars of five skeletally mature male foxhounds, approximately 2 years of age, were extracted. One randomly selected mandibular quadrant had buccal and lingual flaps and corticotomies performed around the second premolar; the other quadrant served as the control. Both maxillary quadrants had initial buccal flaps and corticotomies; one randomly selected quadrant had a second buccal flap surgery and corticotomy after 28 days. Coil springs (200 g force), along with a 0.045 mm diameter tube on a 0.040 mm diameter guiding wire, were used to move the mandibular second and maxillary third premolars. Records, including digital calliper measurements and radiographs, were taken on days 0, 10, 14, 28, 42, and 56. Multilevel statistical procedures were used to model longitudinal tooth movements. The radiographic measurements initially showed increasing mandibular tooth movement rates, peaking between 22 and 25 days, and then decelerating. Total mandibular tooth movements were significantly (P < 0.05) greater on the experimental (2.4 mm) than on the control (1.3 mm) side. The rates of maxillary tooth movement slowed over time, with significantly (P < 0.05) more overall tooth movement on the side that had two (2.3 mm) than one (2.0 mm) corticotomy procedure. Alveolar corticotomy significantly increases orthodontic tooth movement. Performing a second corticotomy procedure after 4 weeks maintained higher rates of tooth movement over a longer duration and produced greater overall tooth movement than performing just one initial corticotomy, but the difference was small.

A clinical rule (sex, contralateral occlusion, age, and restenosis) to select patients for stenting versus carotid endarterectomy: systematic review of observational studies with validation in randomized trials.

PubMed

Touzé, Emmanuel; Trinquart, Ludovic; Felgueiras, Rui; Rerkasem, Kittipan; Bonati, Leo H; Meliksetyan, Gayané; Ringleb, Peter A; Mas, Jean-Louis; Brown, Martin M; Rothwell, Peter M

2013-12-01

Compared with carotid endarterectomy (CEA), carotid angioplasty and stenting (CAS) is associated with a higher risk of procedural stroke or death especially in patients with symptomatic stenosis. However, after the perioperative period, risk is similar with both treatments, suggesting that CAS could be an acceptable option in selected patients. We performed systematic reviews of observational studies of procedural risks of CEA or CAS and extracted data on 9 predefined risk factors (age, contralateral carotid occlusion, coronary artery disease, diabetes mellitus, sex, hypertension, peripheral artery disease, and type and side of stenosis). We calculated pooled relative risks of procedural stroke or death. Factors with differential effects on risk of CAS versus CEA were identified by interaction tests and used to derive a rule. The rule was tested using individual patient data from randomized trials of CAS versus CEA from the Carotid Stenting Trialists' Collaboration (CSTC). We identified 170 studies. The effects of sex, contralateral occlusion, age, and restenosis (SCAR) on the procedural risk of stroke or death differed. Patients with contralateral occlusion or restenosis and women<75 years were at relatively low risk for CAS (SCAR negative), with all others being high risk (SCAR positive). Among the 3049 patients in the CSTC validation, 694 (23%) patients were SCAR negative. The pooled RR of procedural stroke and death with CAS versus CEA was 0.93 (0.49-1.77; P=0.83) in SCAR-negative and 2.41 (1.68-3.45; P<0.0001) in SCAR-positive patients (P [interaction]=0.05). The SCAR rule is potentially useful to identify patients in whom CAS has a similar risk of perioperative stroke or death to CEA.

Selective reminding of prospective memory in Multiple Sclerosis.

PubMed

McKeever, Joshua D; Schultheis, Maria T; Sim, Tiffanie; Goykhman, Jessica; Patrick, Kristina; Ehde, Dawn M; Woods, Steven Paul

2017-04-19

Multiple sclerosis (MS) is associated with prospective memory (PM) deficits, which may increase the risk of poor functional/health outcomes such as medication non-adherence. This study examined the potential benefits of selective reminding to enhance PM functioning in persons with MS. Twenty-one participants with MS and 22 healthy adults (HA) underwent a neuropsychological battery including a Selective Reminding PM (SRPM) experimental procedure. Participants were randomly assigned to either: (1) a selective reminding condition in which participants learn (to criterion) eight prospective memory tasks in a Selective Reminding format; or (2) a single trial encoding condition (1T). A significant interaction was demonstrated, with MS participants receiving greater benefit than HAs from the SR procedure in terms of PM performance. Across diagnostic groups, participants in the SR conditions (vs. 1T conditions) demonstrated significantly better PM performance. Individuals with MS were impaired relative to HAs in the 1T condition, but performance was statistically comparable in the SR condition. This preliminary study suggests that selective reminding can be used to enhance PM cue detection and retrieval in MS. The extent to which selective reminding of PM is effective in naturalistic settings and for health-related behaviours in MS remains to be determined.

Pain Management for Gynecologic Procedures in the Office.

PubMed

Ireland, Luu Doan; Allen, Rebecca H

2016-02-01

Satisfactory pain control for women undergoing office gynecologic procedures is critical for both patient comfort and procedure success. Therefore, it is important for clinicians to be aware of the safety and efficacy of different pain control regimens. This article aimed to review the literature regarding pain control regimens for procedures such as endometrial biopsy, intrauterine device insertion, colposcopy and loop electrosurgical excisional procedure, uterine aspiration, and hysteroscopy. A search of published literature using PubMed was conducted using the following keywords: "pain" or "anesthesia." These terms were paired with the following keywords: "intrauterine device" or "IUD," "endometrial biopsy," "uterine aspiration" or "abortion," "colposcopy" or "loop electrosurgical excisional procedure" or "LEEP," "hysteroscopy" or "hysteroscopic sterilization." The search was conducted through July 2015. Articles were hand reviewed and selected by the authors for study quality. Meta-analyses and randomized controlled trials were prioritized. Although local anesthesia is commonly used for gynecologic procedures, a multimodal approach may be more effective including oral medication, a dedicated emotional support person, and visual or auditory distraction. Women who are nulliparous, are postmenopausal, have a history of dysmenorrhea, or suffer from anxiety are more likely to experience greater pain with gynecologic procedures. Evidence for some interventions exists; however, the interpretation of intervention comparisons is limited by the use of different regimens, pain measurement scales, patient populations, and procedure techniques. There are many options for pain management for office gynecologic procedures, and depending on the procedure, different modalities may work best. The importance of patient counseling and selection cannot be overstated.

Rationale and design of the Patient Related OuTcomes with Endeavor versus Cypher stenting Trial (PROTECT): randomized controlled trial comparing the incidence of stent thrombosis and clinical events after sirolimus or zotarolimus drug-eluting stent implantation.

PubMed

Camenzind, Edoardo; Wijns, William; Mauri, Laura; Boersma, Eric; Parikh, Keyur; Kurowski, Volkhard; Gao, Runlin; Bode, Christoph; Greenwood, John P; Gershlick, Anthony; O'Neill, William; Serruys, Patrick W; Jorissen, Brenda; Steg, P Gabriel

2009-12-01

Drug-eluting stents (DES) reduce restenosis rates compared to bare-metal stents. Most trials using DES enrolled selected patient and lesion subtypes, and primary endpoint focused on angiographic metrics or relatively short-term outcomes. When DES are used in broader types of lesions and patients, important differences may emerge in long-term outcomes between stent types, particularly the incidence of late stent thrombosis. PROTECT is a randomized, open-label trial comparing the long-term safety of the zotarolimus-eluting stent and the sirolimus-eluting stent. The trial has enrolled 8,800 patients representative of those seen in routine clinical practice, undergoing elective, unplanned, or emergency procedures in native coronary arteries in 196 centers in 36 countries. Indications for the procedure and selection of target vessel and lesion characteristics were at the operator's discretion. Procedures could be staged, but no more than 4 target lesions could be treated per patient. Duration of dual antiplatelet therapy was prespecified to achieve similar lengths of treatment in both study arms. The shortest predefined duration was 3 months, as per the manufacturer's instructions. The primary outcome measure is the composite rate of definite and probable stent thrombosis at 3 years, centrally adjudicated using Academic Research Consortium definitions. The main secondary end points are 3-year all-cause mortality, cardiac death, large nonfatal myocardial infarction, and all myocardial infarctions. This large, international, randomized, controlled trial will provide important information on comparative rates of stent thrombosis between 2 different DES systems and safety as assessed by patient-relevant long-term clinical outcomes.

A New Method of Random Environmental Walking for Assessing Behavioral Preferences for Different Lighting Applications

PubMed Central

Patching, Geoffrey R.; Rahm, Johan; Jansson, Märit; Johansson, Maria

2017-01-01

Accurate assessment of people’s preferences for different outdoor lighting applications is increasingly considered important in the development of new urban environments. Here a new method of random environmental walking is proposed to complement current methods of assessing urban lighting applications, such as self-report questionnaires. The procedure involves participants repeatedly walking between different lighting applications by random selection of a lighting application and preferred choice or by random selection of a lighting application alone. In this manner, participants are exposed to all lighting applications of interest more than once and participants’ preferences for the different lighting applications are reflected in the number of times they walk to each lighting application. On the basis of an initial simulation study, to explore the feasibility of this approach, a comprehensive field test was undertaken. The field test included random environmental walking and collection of participants’ subjective ratings of perceived pleasantness (PP), perceived quality, perceived strength, and perceived flicker of four lighting applications. The results indicate that random environmental walking can reveal participants’ preferences for different lighting applications that, in the present study, conformed to participants’ ratings of PP and perceived quality of the lighting applications. As a complement to subjectively stated environmental preferences, random environmental walking has the potential to expose behavioral preferences for different lighting applications. PMID:28337163

Randomized comparison of operator radiation exposure comparing transradial and transfemoral approach for percutaneous coronary procedures: rationale and design of the minimizing adverse haemorrhagic events by TRansradial access site and systemic implementation of angioX - RAdiation Dose study (RAD-MATRIX).

PubMed

Sciahbasi, Alessandro; Calabrò, Paolo; Sarandrea, Alessandro; Rigattieri, Stefano; Tomassini, Francesco; Sardella, Gennaro; Zavalloni, Dennis; Cortese, Bernardo; Limbruno, Ugo; Tebaldi, Matteo; Gagnor, Andrea; Rubartelli, Paolo; Zingarelli, Antonio; Valgimigli, Marco

2014-06-01

Radiation absorbed by interventional cardiologists is a frequently under-evaluated important issue. Aim is to compare radiation dose absorbed by interventional cardiologists during percutaneous coronary procedures for acute coronary syndromes comparing transradial and transfemoral access. The randomized multicentre MATRIX (Minimizing Adverse Haemorrhagic Events by TRansradial Access Site and Systemic Implementation of angioX) trial has been designed to compare the clinical outcome of patients with acute coronary syndromes treated invasively according to the access site (transfemoral vs. transradial) and to the anticoagulant therapy (bivalirudin vs. heparin). Selected experienced interventional cardiologists involved in this study have been equipped with dedicated thermoluminescent dosimeters to evaluate the radiation dose absorbed during transfemoral or right transradial or left transradial access. For each access we evaluate the radiation dose absorbed at wrist, at thorax and at eye level. Consequently the operator is equipped with three sets (transfemoral, right transradial or left transradial access) of three different dosimeters (wrist, thorax and eye dosimeter). Primary end-point of the study is the procedural radiation dose absorbed by operators at thorax. An important secondary end-point is the procedural radiation dose absorbed by operators comparing the right or left radial approach. Patient randomization is performed according to the MATRIX protocol for the femoral or radial approach. A further randomization for the radial approach is performed to compare right and left transradial access. The RAD-MATRIX study will probably consent to clarify the radiation issue for interventional cardiologist comparing transradial and transfemoral access in the setting of acute coronary syndromes. Copyright © 2014 Elsevier Inc. All rights reserved.

Types of Bullying in the Senior High Schools in Ghana

ERIC Educational Resources Information Center

Antiri, Kwasi Otopa

2016-01-01

The main objective of the study was to examine the types of bullying that were taking place in the senior high schools in Ghana. A multi-stage sampling procedure, comprising purposive, simple random and snowball sampling technique, was used in the selection of the sample. A total of 354 respondents were drawn six schools in Ashanti, Central and…

Occupational Commonalities: A Base for Course Construction. Paper No. 2219, Journal Series.

ERIC Educational Resources Information Center

Dillon, Roy D.; Horner, James T.

To determine competencies and activities used by workers in a cross section of the statewide labor force, data were obtained from a random sample of 1,500 employed persons drawn from 14 purposively selected index counties in Nebraska. An interview-questionnaire procedure yielded an 87.7 percent response to a checklist of 144 activities, duties,…

Laying down the Family Burden: A Cross-Cultural Analysis of Resilience in the Midst of Family Violence

ERIC Educational Resources Information Center

Kassis, Wassilis; Artz, Sibylle; Moldenhauer, Stephanie

2013-01-01

Questionnaire data from a cross-sectional study of a randomly selected sample of 5,149 middle-school students from four EU countries (Austria, Germany, Slovenia, and Spain) were used to explore the effects of family violence burden level, structural and procedural risk and protective factors, and personal characteristics on adolescents who are…

Transoral incisionless fundoplication: current status.

PubMed

Sami Trad, Karim

2016-07-01

Transoral incisionless fundoplication (TIF) performed with the EsophyX device (Redmond, Washington, USA) is a totally endoscopic procedure with the objectives to mechanically repair a defective gastroesophageal valve and to reduce small hiatal hernias. The recent publication of randomized controlled trials and long-term follow-up data offers the opportunity to reevaluate this treatment modality and its role in the management of patients with chronic gastroesophageal reflux disease (GERD). Randomized controlled trials have confirmed the ability of TIF to eliminate troublesome GERD symptoms, heal esophagitis, and improve distal esophageal acid exposure in appropriately selected patient populations. These studies establish TIF's superiority to conventional medical therapy, especially in clinical scenarios where proton-pump inhibitors fail to provide complete symptom relief across the spectrum of classic and atypical GERD manifestations, including regurgitation and laryngopharyngeal reflux. Long-term data indicate sustained positive outcomes and durability up to 6 years after procedure. These results were achieved with a low rate of serious adverse events and usually without introducing troublesome dysphagia, gas bloat, or flatulence. Based on the most recent data, TIF appears to be a valuable treatment alternative for the management of appropriately selected patients with moderate to severe chronic GERD symptoms.

Comparative evaluation of stress levels before, during, and after periodontal surgical procedures with and without nitrous oxide-oxygen inhalation sedation

PubMed Central

Sandhu, Gurkirat; Khinda, Paramjit Kaur; Gill, Amarjit Singh; Singh Khinda, Vineet Inder; Baghi, Kamal; Chahal, Gurparkash Singh

2017-01-01

Context: Periodontal surgical procedures produce varying degree of stress in all patients. Nitrous oxide-oxygen inhalation sedation is very effective for adult patients with mild-to-moderate anxiety due to dental procedures and needle phobia. Aim: The present study was designed to perform periodontal surgical procedures under nitrous oxide-oxygen inhalation sedation and assess whether this technique actually reduces stress physiologically, in comparison to local anesthesia alone (LA) during lengthy periodontal surgical procedures. Settings and Design: This was a randomized, split-mouth, cross-over study. Materials and Methods: A total of 16 patients were selected for this randomized, split-mouth, cross-over study. One surgical session (SS) was performed under local anesthesia aided by nitrous oxide-oxygen inhalation sedation, and the other SS was performed on the contralateral quadrant under LA. For each session, blood samples to measure and evaluate serum cortisol levels were obtained, and vital parameters including blood pressure, heart rate, respiratory rate, and arterial blood oxygen saturation were monitored before, during, and after periodontal surgical procedures. Statistical Analysis Used: Paired t-test and repeated measure ANOVA. Results: The findings of the present study revealed a statistically significant decrease in serum cortisol levels, blood pressure and pulse rate and a statistically significant increase in respiratory rate and arterial blood oxygen saturation during periodontal surgical procedures under nitrous oxide inhalation sedation. Conclusion: Nitrous oxide-oxygen inhalation sedation for periodontal surgical procedures is capable of reducing stress physiologically, in comparison to LA during lengthy periodontal surgical procedures. PMID:29386796

Use of Random and Site-Directed Mutagenesis to Probe Protein Structure-Function Relationships: Applied Techniques in the Study of Helicobacter pylori.

PubMed

Whitmire, Jeannette M; Merrell, D Scott

2017-01-01

Mutagenesis is a valuable tool to examine the structure-function relationships of bacterial proteins. As such, a wide variety of mutagenesis techniques and strategies have been developed. This chapter details a selection of random mutagenesis methods and site-directed mutagenesis procedures that can be applied to an array of bacterial species. Additionally, the direct application of the techniques to study the Helicobacter pylori Ferric Uptake Regulator (Fur) protein is described. The varied approaches illustrated herein allow the robust investigation of the structural-functional relationships within a protein of interest.

Knowledge diffusion of dynamical network in terms of interaction frequency.

PubMed

Liu, Jian-Guo; Zhou, Qing; Guo, Qiang; Yang, Zhen-Hua; Xie, Fei; Han, Jing-Ti

2017-09-07

In this paper, we present a knowledge diffusion (SKD) model for dynamic networks by taking into account the interaction frequency which always used to measure the social closeness. A set of agents, which are initially interconnected to form a random network, either exchange knowledge with their neighbors or move toward a new location through an edge-rewiring procedure. The activity of knowledge exchange between agents is determined by a knowledge transfer rule that the target node would preferentially select one neighbor node to transfer knowledge with probability p according to their interaction frequency instead of the knowledge distance, otherwise, the target node would build a new link with its second-order neighbor preferentially or select one node in the system randomly with probability 1 - p. The simulation results show that, comparing with the Null model defined by the random selection mechanism and the traditional knowledge diffusion (TKD) model driven by knowledge distance, the knowledge would spread more fast based on SKD driven by interaction frequency. In particular, the network structure of SKD would evolve as an assortative one, which is a fundamental feature of social networks. This work would be helpful for deeply understanding the coevolution of the knowledge diffusion and network structure.

featsel: A framework for benchmarking of feature selection algorithms and cost functions

NASA Astrophysics Data System (ADS)

Reis, Marcelo S.; Estrela, Gustavo; Ferreira, Carlos Eduardo; Barrera, Junior

In this paper, we introduce featsel, a framework for benchmarking of feature selection algorithms and cost functions. This framework allows the user to deal with the search space as a Boolean lattice and has its core coded in C++ for computational efficiency purposes. Moreover, featsel includes Perl scripts to add new algorithms and/or cost functions, generate random instances, plot graphs and organize results into tables. Besides, this framework already comes with dozens of algorithms and cost functions for benchmarking experiments. We also provide illustrative examples, in which featsel outperforms the popular Weka workbench in feature selection procedures on data sets from the UCI Machine Learning Repository.

Selective detection of underivatized 2,4-dichlorophenoxyacetic acid in soil by supercritical fluid chromatography with ion mobility detection.

PubMed

Morrissey, M A; Hill, H H

1989-09-01

A simplified procedure was developed for the determination of 2,4-dichlorophenoxyacetic acid (2,4-D) in soils. Soil samples were separated by supercritical fluid chromatography after extraction without derivatization and without the use of column chromatography for cleanup. Interferences in the chromatographic separation were eliminated by using a tunably selective ion mobility detector. An atmospheric pressure ion formed by the free acid was selectively monitored so the detector could monitor 2,4-D in the presence of other electron-capturing compounds. For a randomly chosen soil sample, the level of 2,4-D detected was estimated at 500 ppb.

Intelligent Fault Diagnosis of HVCB with Feature Space Optimization-Based Random Forest

PubMed Central

Ma, Suliang; Wu, Jianwen; Wang, Yuhao; Jia, Bowen; Jiang, Yuan

2018-01-01

Mechanical faults of high-voltage circuit breakers (HVCBs) always happen over long-term operation, so extracting the fault features and identifying the fault type have become a key issue for ensuring the security and reliability of power supply. Based on wavelet packet decomposition technology and random forest algorithm, an effective identification system was developed in this paper. First, compared with the incomplete description of Shannon entropy, the wavelet packet time-frequency energy rate (WTFER) was adopted as the input vector for the classifier model in the feature selection procedure. Then, a random forest classifier was used to diagnose the HVCB fault, assess the importance of the feature variable and optimize the feature space. Finally, the approach was verified based on actual HVCB vibration signals by considering six typical fault classes. The comparative experiment results show that the classification accuracy of the proposed method with the origin feature space reached 93.33% and reached up to 95.56% with optimized input feature vector of classifier. This indicates that feature optimization procedure is successful, and the proposed diagnosis algorithm has higher efficiency and robustness than traditional methods. PMID:29659548

Performance of time-varying predictors in multilevel models under an assumption of fixed or random effects.

PubMed

Baird, Rachel; Maxwell, Scott E

2016-06-01

Time-varying predictors in multilevel models are a useful tool for longitudinal research, whether they are the research variable of interest or they are controlling for variance to allow greater power for other variables. However, standard recommendations to fix the effect of time-varying predictors may make an assumption that is unlikely to hold in reality and may influence results. A simulation study illustrates that treating the time-varying predictor as fixed may allow analyses to converge, but the analyses have poor coverage of the true fixed effect when the time-varying predictor has a random effect in reality. A second simulation study shows that treating the time-varying predictor as random may have poor convergence, except when allowing negative variance estimates. Although negative variance estimates are uninterpretable, results of the simulation show that estimates of the fixed effect of the time-varying predictor are as accurate for these cases as for cases with positive variance estimates, and that treating the time-varying predictor as random and allowing negative variance estimates performs well whether the time-varying predictor is fixed or random in reality. Because of the difficulty of interpreting negative variance estimates, 2 procedures are suggested for selection between fixed-effect and random-effect models: comparing between fixed-effect and constrained random-effect models with a likelihood ratio test or fitting a fixed-effect model when an unconstrained random-effect model produces negative variance estimates. The performance of these 2 procedures is compared. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Nonlinear probabilistic finite element models of laminated composite shells

NASA Technical Reports Server (NTRS)

Engelstad, S. P.; Reddy, J. N.

1993-01-01

A probabilistic finite element analysis procedure for laminated composite shells has been developed. A total Lagrangian finite element formulation, employing a degenerated 3-D laminated composite shell with the full Green-Lagrange strains and first-order shear deformable kinematics, forms the modeling foundation. The first-order second-moment technique for probabilistic finite element analysis of random fields is employed and results are presented in the form of mean and variance of the structural response. The effects of material nonlinearity are included through the use of a rate-independent anisotropic plasticity formulation with the macroscopic point of view. Both ply-level and micromechanics-level random variables can be selected, the latter by means of the Aboudi micromechanics model. A number of sample problems are solved to verify the accuracy of the procedures developed and to quantify the variability of certain material type/structure combinations. Experimental data is compared in many cases, and the Monte Carlo simulation method is used to check the probabilistic results. In general, the procedure is quite effective in modeling the mean and variance response of the linear and nonlinear behavior of laminated composite shells.

Randomization of grab-sampling strategies for estimating the annual exposure of U miners to Rn daughters.

PubMed

Borak, T B

1986-04-01

Periodic grab sampling in combination with time-of-occupancy surveys has been the accepted procedure for estimating the annual exposure of underground U miners to Rn daughters. Temporal variations in the concentration of potential alpha energy in the mine generate uncertainties in this process. A system to randomize the selection of locations for measurement is described which can reduce uncertainties and eliminate systematic biases in the data. In general, a sample frequency of 50 measurements per year is sufficient to satisfy the criteria that the annual exposure be determined in working level months to within +/- 50% of the true value with a 95% level of confidence. Suggestions for implementing this randomization scheme are presented.

Selective epidemic vaccination under the performant routing algorithms

NASA Astrophysics Data System (ADS)

Bamaarouf, O.; Alweimine, A. Ould Baba; Rachadi, A.; EZ-Zahraouy, H.

2018-04-01

Despite the extensive research on traffic dynamics and epidemic spreading, the effect of the routing algorithms strategies on the traffic-driven epidemic spreading has not received an adequate attention. It is well known that more performant routing algorithm strategies are used to overcome the congestion problem. However, our main result shows unexpectedly that these algorithms favor the virus spreading more than the case where the shortest path based algorithm is used. In this work, we studied the virus spreading in a complex network using the efficient path and the global dynamic routing algorithms as compared to shortest path strategy. Some previous studies have tried to modify the routing rules to limit the virus spreading, but at the expense of reducing the traffic transport efficiency. This work proposed a solution to overcome this drawback by using a selective vaccination procedure instead of a random vaccination used often in the literature. We found that the selective vaccination succeeded in eradicating the virus better than a pure random intervention for the performant routing algorithm strategies.

Does self-selection affect samples' representativeness in online surveys? An investigation in online video game research.

PubMed

Khazaal, Yasser; van Singer, Mathias; Chatton, Anne; Achab, Sophia; Zullino, Daniele; Rothen, Stephane; Khan, Riaz; Billieux, Joel; Thorens, Gabriel

2014-07-07

The number of medical studies performed through online surveys has increased dramatically in recent years. Despite their numerous advantages (eg, sample size, facilitated access to individuals presenting stigmatizing issues), selection bias may exist in online surveys. However, evidence on the representativeness of self-selected samples in online studies is patchy. Our objective was to explore the representativeness of a self-selected sample of online gamers using online players' virtual characters (avatars). All avatars belonged to individuals playing World of Warcraft (WoW), currently the most widely used online game. Avatars' characteristics were defined using various games' scores, reported on the WoW's official website, and two self-selected samples from previous studies were compared with a randomly selected sample of avatars. We used scores linked to 1240 avatars (762 from the self-selected samples and 478 from the random sample). The two self-selected samples of avatars had higher scores on most of the assessed variables (except for guild membership and exploration). Furthermore, some guilds were overrepresented in the self-selected samples. Our results suggest that more proficient players or players more involved in the game may be more likely to participate in online surveys. Caution is needed in the interpretation of studies based on online surveys that used a self-selection recruitment procedure. Epidemiological evidence on the reduced representativeness of sample of online surveys is warranted.

Context-specific control and the Stroop negative priming effect.

PubMed

Milliken, Bruce; Thomson, David R; Bleile, Karmen; MacLellan, Ellen; Giammarco, Maria

2012-01-01

The present study highlights the utility of context-specific learning for different probe types in accounting for the commonly observed dependence of negative priming on probe selection. Using a Stroop priming procedure, Experiments 1a and 1b offered a demonstration that Stroop priming effects can differ qualitatively for selection and no-selection probes when probe selection is manipulated between subjects, but not when it is manipulated randomly from trial to trial within subject (see also Moore, 1994). In Experiments 2 and 3, selection and no-selection probes served as two contexts that varied randomly from trial to trial, but for which proportion repeated was manipulated separately. A context-specific proportion repeated effect was observed in Experiment 2, characterized by modest quantitative shifts in the repetition effects as a function of the context-specific proportion repeated manipulation. However, with a longer intertrial interval in Experiment 3, a context-specific proportion repeated manipulation that focused on the no-selection probes changed the repetition effect qualitatively, from negative priming when the proportion repeated was .25 to positive priming when the proportion repeated was .75. The results are discussed with reference to the role of rapid, context-specific learning processes in the integration of prior experiences with current perception and action.

Blocking for Sequential Political Experiments

PubMed Central

Moore, Sally A.

2013-01-01

In typical political experiments, researchers randomize a set of households, precincts, or individuals to treatments all at once, and characteristics of all units are known at the time of randomization. However, in many other experiments, subjects “trickle in” to be randomized to treatment conditions, usually via complete randomization. To take advantage of the rich background data that researchers often have (but underutilize) in these experiments, we develop methods that use continuous covariates to assign treatments sequentially. We build on biased coin and minimization procedures for discrete covariates and demonstrate that our methods outperform complete randomization, producing better covariate balance in simulated data. We then describe how we selected and deployed a sequential blocking method in a clinical trial and demonstrate the advantages of our having done so. Further, we show how that method would have performed in two larger sequential political trials. Finally, we compare causal effect estimates from differences in means, augmented inverse propensity weighted estimators, and randomization test inversion. PMID:24143061

Correcting Classifiers for Sample Selection Bias in Two-Phase Case-Control Studies

PubMed Central

Theis, Fabian J.

2017-01-01

Epidemiological studies often utilize stratified data in which rare outcomes or exposures are artificially enriched. This design can increase precision in association tests but distorts predictions when applying classifiers on nonstratified data. Several methods correct for this so-called sample selection bias, but their performance remains unclear especially for machine learning classifiers. With an emphasis on two-phase case-control studies, we aim to assess which corrections to perform in which setting and to obtain methods suitable for machine learning techniques, especially the random forest. We propose two new resampling-based methods to resemble the original data and covariance structure: stochastic inverse-probability oversampling and parametric inverse-probability bagging. We compare all techniques for the random forest and other classifiers, both theoretically and on simulated and real data. Empirical results show that the random forest profits from only the parametric inverse-probability bagging proposed by us. For other classifiers, correction is mostly advantageous, and methods perform uniformly. We discuss consequences of inappropriate distribution assumptions and reason for different behaviors between the random forest and other classifiers. In conclusion, we provide guidance for choosing correction methods when training classifiers on biased samples. For random forests, our method outperforms state-of-the-art procedures if distribution assumptions are roughly fulfilled. We provide our implementation in the R package sambia. PMID:29312464

Applying a weighted random forests method to extract karst sinkholes from LiDAR data

NASA Astrophysics Data System (ADS)

Zhu, Junfeng; Pierskalla, William P.

2016-02-01

Detailed mapping of sinkholes provides critical information for mitigating sinkhole hazards and understanding groundwater and surface water interactions in karst terrains. LiDAR (Light Detection and Ranging) measures the earth's surface in high-resolution and high-density and has shown great potentials to drastically improve locating and delineating sinkholes. However, processing LiDAR data to extract sinkholes requires separating sinkholes from other depressions, which can be laborious because of the sheer number of the depressions commonly generated from LiDAR data. In this study, we applied the random forests, a machine learning method, to automatically separate sinkholes from other depressions in a karst region in central Kentucky. The sinkhole-extraction random forest was grown on a training dataset built from an area where LiDAR-derived depressions were manually classified through a visual inspection and field verification process. Based on the geometry of depressions, as well as natural and human factors related to sinkholes, 11 parameters were selected as predictive variables to form the dataset. Because the training dataset was imbalanced with the majority of depressions being non-sinkholes, a weighted random forests method was used to improve the accuracy of predicting sinkholes. The weighted random forest achieved an average accuracy of 89.95% for the training dataset, demonstrating that the random forest can be an effective sinkhole classifier. Testing of the random forest in another area, however, resulted in moderate success with an average accuracy rate of 73.96%. This study suggests that an automatic sinkhole extraction procedure like the random forest classifier can significantly reduce time and labor costs and makes its more tractable to map sinkholes using LiDAR data for large areas. However, the random forests method cannot totally replace manual procedures, such as visual inspection and field verification.

A Study of Information Content in the U.S. Television Commercials: Has It Become Less Informative but More Creative?

ERIC Educational Resources Information Center

Ng, Daniel; Supaporn, Potibut

A study investigated the trend of current U.S. television commercial informativeness by comparing the results with Alan Resnik and Bruce Stern's previous benchmark study conducted in 1977. A systematic random sampling procedure was used to select viewing dates and times of commercials from the three national networks. Ultimately, a total of 550…

Stress and Coping Strategies among Distance Education Students at the University of Cape Coast, Ghana

ERIC Educational Resources Information Center

Kwaah, Christopher Yaw; Essilfie, Gabriel

2017-01-01

This study was designed to identify the causes of stress and coping strategies adopted among distance education students at the College of Distance Education in the University of Cape Coast. A total of 332 diploma and post-diploma final year students in 2014/2015 academic year were selected from two study centers using random sampling procedure to…

Guidelines for patient selection and performance of carotid artery stenting.

PubMed

Bladin, Christopher; Chambers, Brian; New, Gishel; Denton, Michael; Lawrence-Brown, Michael

2010-06-01

The endovascular treatment of carotid atherosclerosis with carotid artery stenting (CAS) remains controversial. Carotid endarterectomy remains the benchmark in terms of procedural mortality and morbidity. At present, there are no consensus Australasian guidelines for the safe performance of CAS. We applied a modified Delphi consensus method of iterative consultation between the College representatives on the Carotid Stenting Guidelines Committee (CSGC). Selection of patients suitable for CAS needs careful consideration of clinical and patho-anatomical criteria and cannot be directly extrapolated from clinical indicators for carotid endarterectomy (CEA). Randomized controlled trials (including pooled analyses of results) comparing CAS with CEA for treatment of symptomatic stenosis have demonstrated that CAS is more hazardous than CEA. On current evidence, the CGSC therefore recommends that CAS should not be performed in the majority of patients requiring carotid revascularisation. The evidence for CAS in patients with symptomatic severe carotid stenosis who are considered medically high risk is weak, and there is currently no evidence to support CAS as a treatment for asymptomatic carotid stenosis. The use of distal protection devices during CAS remains controversial with increased risk of clinically silent stroke. The knowledge requirements for the safe performance of CAS include an understanding of the evidence base from randomized controlled trials, carotid and aortic arch anatomy and pathology, clinical stroke syndromes, the differing treatment options for stroke and carotid atherosclerosis, and recognition and management of periprocedural complications. It is critical that all patients being considered for a carotid intervention have adequate pre-procedural neuro-imaging and an independent, standardized neurological assessment before and after the procedure. Maintenance of proficiency in CAS requires active involvement in surgical/endovascular audit and continuing medical education programs. These standards should apply in the public and private health care settings. These guidelines represent the consensus of an inter-collegiate committee in order to direct appropriate patient selection and the range of cognitive and technical requirements to perform CAS. Advances in endovascular technologies and the results of randomized controlled trials will guide future revisions of these guidelines.

Do plastic surgeons have cosmetic surgery?

PubMed

Gurunluoglu, Raffi; Gurunluoglu, Aslin

2009-12-01

Thoughts and attitudes of plastic surgeons about having cosmetic surgery on themselves remain obscure for the most part and pose an attractive subject to study. A survey was distributed to a random sample of 2635 American Society of Plastic Surgeons member and candidate member surgeons to determine plastic surgeons' interest in both minimally invasive cosmetic procedures and cosmetic surgical procedures, selection of facility type, selection of surgeon, and their satisfaction level. There were 276 responses. Sixty-two percent of the plastic surgeons had undergone at least one type of minimally invasive cosmetic procedure. Female plastic surgeons had significantly more minimally invasive cosmetic procedures compared with male plastic surgeons (84.9 versus 57 percent; p < 0.05). The most common procedure was botulinum toxin type A injection (31.5 percent). Approximately one-third of plastic surgeons had at least one type of cosmetic surgery. The most common cosmetic surgical procedure was liposuction of the trunk and/or extremity (18.6 percent). Male plastic surgeons were more likely to have a procedure than men in the general population, and female plastic surgeons were less likely to have breast augmentation than the general population. The percentage of operations conducted by a plastic surgeon was 88.2 percent. The percentage performed by a nationally known surgeon was 45.3 percent; 75.9 percent of plastic surgeons selected a surgeon who was certified by the American Board of Plastic Surgery. The satisfaction rate was 90 percent. The survey provides insight on the stance of American Society of Plastic Surgeons member and candidate member surgeons on the subject. To the authors' knowledge, this is the first survey designed for this purpose.

Inverse probability weighting in STI/HIV prevention research: methods for evaluating social and community interventions

PubMed Central

Lippman, Sheri A.; Shade, Starley B.; Hubbard, Alan E.

2011-01-01

Background Intervention effects estimated from non-randomized intervention studies are plagued by biases, yet social or structural intervention studies are rarely randomized. There are underutilized statistical methods available to mitigate biases due to self-selection, missing data, and confounding in longitudinal, observational data permitting estimation of causal effects. We demonstrate the use of Inverse Probability Weighting (IPW) to evaluate the effect of participating in a combined clinical and social STI/HIV prevention intervention on reduction of incident chlamydia and gonorrhea infections among sex workers in Brazil. Methods We demonstrate the step-by-step use of IPW, including presentation of the theoretical background, data set up, model selection for weighting, application of weights, estimation of effects using varied modeling procedures, and discussion of assumptions for use of IPW. Results 420 sex workers contributed data on 840 incident chlamydia and gonorrhea infections. Participators were compared to non-participators following application of inverse probability weights to correct for differences in covariate patterns between exposed and unexposed participants and between those who remained in the intervention and those who were lost-to-follow-up. Estimators using four model selection procedures provided estimates of intervention effect between odds ratio (OR) .43 (95% CI:.22-.85) and .53 (95% CI:.26-1.1). Conclusions After correcting for selection bias, loss-to-follow-up, and confounding, our analysis suggests a protective effect of participating in the Encontros intervention. Evaluations of behavioral, social, and multi-level interventions to prevent STI can benefit by introduction of weighting methods such as IPW. PMID:20375927

Evaluation of new collision-pair selection models in DSMC

NASA Astrophysics Data System (ADS)

Akhlaghi, Hassan; Roohi, Ehsan

2017-10-01

The current paper investigates new collision-pair selection procedures in a direct simulation Monte Carlo (DSMC) method. Collision partner selection based on the random procedure from nearest neighbor particles and deterministic selection of nearest neighbor particles have already been introduced as schemes that provide accurate results in a wide range of problems. In the current research, new collision-pair selections based on the time spacing and direction of the relative movement of particles are introduced and evaluated. Comparisons between the new and existing algorithms are made considering appropriate test cases including fluctuations in homogeneous gas, 2D equilibrium flow, and Fourier flow problem. Distribution functions for number of particles and collisions in cell, velocity components, and collisional parameters (collision separation, time spacing, relative velocity, and the angle between relative movements of particles) are investigated and compared with existing analytical relations for each model. The capability of each model in the prediction of the heat flux in the Fourier problem at different cell numbers, numbers of particles, and time steps is examined. For new and existing collision-pair selection schemes, the effect of an alternative formula for the number of collision-pair selections and avoiding repetitive collisions are investigated via the prediction of the Fourier heat flux. The simulation results demonstrate the advantages and weaknesses of each model in different test cases.

Continuous Shape Estimation of Continuum Robots Using X-ray Images

PubMed Central

Lobaton, Edgar J.; Fu, Jinghua; Torres, Luis G.; Alterovitz, Ron

2015-01-01

We present a new method for continuously and accurately estimating the shape of a continuum robot during a medical procedure using a small number of X-ray projection images (e.g., radiographs or fluoroscopy images). Continuum robots have curvilinear structure, enabling them to maneuver through constrained spaces by bending around obstacles. Accurately estimating the robot’s shape continuously over time is crucial for the success of procedures that require avoidance of anatomical obstacles and sensitive tissues. Online shape estimation of a continuum robot is complicated by uncertainty in its kinematic model, movement of the robot during the procedure, noise in X-ray images, and the clinical need to minimize the number of X-ray images acquired. Our new method integrates kinematics models of the robot with data extracted from an optimally selected set of X-ray projection images. Our method represents the shape of the continuum robot over time as a deformable surface which can be described as a linear combination of time and space basis functions. We take advantage of probabilistic priors and numeric optimization to select optimal camera configurations, thus minimizing the expected shape estimation error. We evaluate our method using simulated concentric tube robot procedures and demonstrate that obtaining between 3 and 10 images from viewpoints selected by our method enables online shape estimation with errors significantly lower than using the kinematic model alone or using randomly spaced viewpoints. PMID:26279960

Continuous Shape Estimation of Continuum Robots Using X-ray Images.

PubMed

Lobaton, Edgar J; Fu, Jinghua; Torres, Luis G; Alterovitz, Ron

2013-05-06

We present a new method for continuously and accurately estimating the shape of a continuum robot during a medical procedure using a small number of X-ray projection images (e.g., radiographs or fluoroscopy images). Continuum robots have curvilinear structure, enabling them to maneuver through constrained spaces by bending around obstacles. Accurately estimating the robot's shape continuously over time is crucial for the success of procedures that require avoidance of anatomical obstacles and sensitive tissues. Online shape estimation of a continuum robot is complicated by uncertainty in its kinematic model, movement of the robot during the procedure, noise in X-ray images, and the clinical need to minimize the number of X-ray images acquired. Our new method integrates kinematics models of the robot with data extracted from an optimally selected set of X-ray projection images. Our method represents the shape of the continuum robot over time as a deformable surface which can be described as a linear combination of time and space basis functions. We take advantage of probabilistic priors and numeric optimization to select optimal camera configurations, thus minimizing the expected shape estimation error. We evaluate our method using simulated concentric tube robot procedures and demonstrate that obtaining between 3 and 10 images from viewpoints selected by our method enables online shape estimation with errors significantly lower than using the kinematic model alone or using randomly spaced viewpoints.

Evaluation of Bias-Variance Trade-Off for Commonly Used Post-Summarizing Normalization Procedures in Large-Scale Gene Expression Studies

PubMed Central

Qiu, Xing; Hu, Rui; Wu, Zhixin

2014-01-01

Normalization procedures are widely used in high-throughput genomic data analyses to remove various technological noise and variations. They are known to have profound impact to the subsequent gene differential expression analysis. Although there has been some research in evaluating different normalization procedures, few attempts have been made to systematically evaluate the gene detection performances of normalization procedures from the bias-variance trade-off point of view, especially with strong gene differentiation effects and large sample size. In this paper, we conduct a thorough study to evaluate the effects of normalization procedures combined with several commonly used statistical tests and MTPs under different configurations of effect size and sample size. We conduct theoretical evaluation based on a random effect model, as well as simulation and biological data analyses to verify the results. Based on our findings, we provide some practical guidance for selecting a suitable normalization procedure under different scenarios. PMID:24941114

A smart Monte Carlo procedure for production costing and uncertainty analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parker, C.; Stremel, J.

1996-11-01

Electric utilities using chronological production costing models to decide whether to buy or sell power over the next week or next few weeks need to determine potential profits or losses under a number of uncertainties. A large amount of money can be at stake--often $100,000 a day or more--and one party of the sale must always take on the risk. In the case of fixed price ($/MWh) contracts, the seller accepts the risk. In the case of cost plus contracts, the buyer must accept the risk. So, modeling uncertainty and understanding the risk accurately can improve the competitive edge ofmore » the user. This paper investigates an efficient procedure for representing risks and costs from capacity outages. Typically, production costing models use an algorithm based on some form of random number generator to select resources as available or on outage. These algorithms allow experiments to be repeated and gains and losses to be observed in a short time. The authors perform several experiments to examine the capability of three unit outage selection methods and measures their results. Specifically, a brute force Monte Carlo procedure, a Monte Carlo procedure with Latin Hypercube sampling, and a Smart Monte Carlo procedure with cost stratification and directed sampling are examined.« less

Prophylaxis of pancreatitis with intravenous ketoprofen in a consecutive population of ERCP patients: a randomized double-blind placebo-controlled trial.

PubMed

de Quadros Onófrio, Fernanda; Lima, Julio Carlos Pereira; Watte, Guilherme; Lehmen, Romnei Lenon; Oba, Daniela; Camargo, Gabriela; Dos Santos, Carlos Eduardo Oliveira

2017-05-01

Background Acute pancreatitis is the most common complication after ERCP, occurring in about 4 % of the procedures. Only the placement of pancreatic duct prosthesis and the use of nonsteroidal anti-inflammatory drugs (NSAIDs) have shown benefit in the prevention of post-ERCP pancreatitis (PEP). Although the benefit of rectal administration of indomethacin or diclofenac is recommended by some studies and society guidelines especially in a selected group of high-risk patients, there is so far, no standardization of time or route of NSAID administration. The aim of the current study is to investigate the role of an intravenous NSAID administered before the procedure for PEP prevention. Methods In this randomized double-blind clinical trial, all consecutive patients who underwent ERCP were randomized to receive saline infusion with ketoprofen or saline, immediately before the procedure. Results A total of 477 patients were enrolled and completed follow-up. The majority of patients (72.1 %) had bile duct stones, and only 1.5 % had a clinical suspicion of sphincter of Oddi dysfunction. PEP developed in 5 of 253 (2 %) patients in the placebo group and in 5 of 224 (2.2 %) patients in the ketoprofen group (p = 1.). Conclusions Intravenous administration of ketoprofen immediately prior to ERCP did not result in reduction in PEP in a general population of ERCP patients.

Study of Dynamic Characteristics of Aeroelastic Systems Utilizing Randomdec Signatures

NASA Technical Reports Server (NTRS)

Chang, C. S.

1975-01-01

The feasibility of utilizing the random decrement method in conjunction with a signature analysis procedure to determine the dynamic characteristics of an aeroelastic system for the purpose of on-line prediction of potential on-set of flutter was examined. Digital computer programs were developed to simulate sampled response signals of a two-mode aeroelastic system. Simulated response data were used to test the random decrement method. A special curve-fit approach was developed for analyzing the resulting signatures. A number of numerical 'experiments' were conducted on the combined processes. The method is capable of determining frequency and damping values accurately from randomdec signatures of carefully selected lengths.

Randomized controlled study of customized preventive medicine reminder letters in a community practice.

PubMed Central

Hogg, W. E.; Bass, M.; Calonge, N.; Crouch, H.; Satenstein, G.

1998-01-01

OBJECTIVE: To test the effectiveness of customized, family-oriented reminder letters in activating patients to seek appropriate preventive services. DESIGN: Randomized clinical trial. One group received computer-generated, customized letters explaining recommended preventive procedures for each family member. A second group received a form letter listing recommendations for all preventive procedures for all age and sex groups. A third group (control group) received no letters. SETTING: A private medical centre, without university affiliation, in rural Quebec. PARTICIPANTS: From 8770 patients who met study criteria, 719 families were randomly selected. Data were available for 1971 of 1998 patients in these families. MAIN OUTCOME MEASURES: The Family Received Index is the proportion of all procedures for which a family was overdue that they received. The Family End-of-study Up-to-date Index is the proportion of procedures for which the family was eligible and for which they were up-to-date at the end of the study. RESULTS: The Family Received Index for families mailed customized letters was more than double the index for patients not mailed letters (Kruskal-Wallis P = .0139). Comparison of the Family End-of-study Up-to-date indices also demonstrated that families of patients sent customized letters were more likely to be up-to-date than families not sent letters (Kruskal-Wallis P = .0054). No statistically significant difference appeared between the number of preventive measures received by the control group and the form-letter group. CONCLUSIONS: This study demonstrates a clinically small but statistically significant value to customizing reminder letters. PMID:9481466

A Random Forest Based Risk Model for Reliable and Accurate Prediction of Receipt of Transfusion in Patients Undergoing Percutaneous Coronary Intervention

PubMed Central

Gurm, Hitinder S.; Kooiman, Judith; LaLonde, Thomas; Grines, Cindy; Share, David; Seth, Milan

2014-01-01

Background Transfusion is a common complication of Percutaneous Coronary Intervention (PCI) and is associated with adverse short and long term outcomes. There is no risk model for identifying patients most likely to receive transfusion after PCI. The objective of our study was to develop and validate a tool for predicting receipt of blood transfusion in patients undergoing contemporary PCI. Methods Random forest models were developed utilizing 45 pre-procedural clinical and laboratory variables to estimate the receipt of transfusion in patients undergoing PCI. The most influential variables were selected for inclusion in an abbreviated model. Model performance estimating transfusion was evaluated in an independent validation dataset using area under the ROC curve (AUC), with net reclassification improvement (NRI) used to compare full and reduced model prediction after grouping in low, intermediate, and high risk categories. The impact of procedural anticoagulation on observed versus predicted transfusion rates were assessed for the different risk categories. Results Our study cohort was comprised of 103,294 PCI procedures performed at 46 hospitals between July 2009 through December 2012 in Michigan of which 72,328 (70%) were randomly selected for training the models, and 30,966 (30%) for validation. The models demonstrated excellent calibration and discrimination (AUC: full model  = 0.888 (95% CI 0.877–0.899), reduced model AUC = 0.880 (95% CI, 0.868–0.892), p for difference 0.003, NRI = 2.77%, p = 0.007). Procedural anticoagulation and radial access significantly influenced transfusion rates in the intermediate and high risk patients but no clinically relevant impact was noted in low risk patients, who made up 70% of the total cohort. Conclusions The risk of transfusion among patients undergoing PCI can be reliably calculated using a novel easy to use computational tool (https://bmc2.org/calculators/transfusion). This risk prediction algorithm may prove useful for both bed side clinical decision making and risk adjustment for assessment of quality. PMID:24816645

0.025-inch vs 0.035-inch guide wires for wire-guided cannulation during endoscopic retrograde cholangiopancreatography: A randomized study

PubMed Central

Kitamura, Katsuya; Yamamiya, Akira; Ishii, Yu; Sato, Yoshiki; Iwata, Tomoyuki; Nomoto, Tomohiro; Ikegami, Akitoshi; Yoshida, Hitoshi

2015-01-01

AIM: To compare the clinical outcomes between 0.025-inch and 0.035-inch guide wires (GWs) when used in wire-guided cannulation (WGC). METHODS: A single center, randomized study was conducted between April 2011 and March 2013. This study was approved by the Medical Ethics Committee at our hospital. Informed, written consent was obtained from each patient prior to study enrollment. Three hundred and twenty-two patients with a naïve papilla of Vater who underwent endoscopic retrograde cholangiopancreatography (ERCP) for the purpose of selective bile duct cannulation with WGC were enrolled in this study. Fifty-three patients were excluded based on the exclusion criteria, and 269 patients were randomly allocated to two groups by a computer and analyzed: the 0.025-inch GW group (n = 109) and the 0.035-inch GW group (n = 160). The primary endpoint was the success rate of selective bile duct cannulation with WGC. Secondary endpoints were the success rates of the pancreatic GW technique and precutting, selective bile duct cannulation time, ERCP procedure time, the rate of pancreatic duct stent placement, the final success rate of selective bile duct cannulation, and the incidence of post-ERCP pancreatitis (PEP). RESULTS: The primary success rates of selective bile duct cannulation with WGC were 80.7% (88/109) and 86.3% (138/160) for the 0.025-inch and the 0.035-inch groups, respectively (P = 0.226). There were no statistically significant differences in the success rates of selective bile duct cannulation using the pancreatic duct GW technique (46.7% vs 52.4% for the 0.025-inch and 0.035-inch groups, respectively; P = 0.884) or in the success rates of selective bile duct cannulation using precutting (66.7% vs 63.6% for the 0.025-inch and 0.035-inch groups, respectively; P = 0.893). The final success rates for selective bile duct cannulation using these procedures were 92.7% (101/109) and 97.5% (156/160) for the 0.025-inch and 0.035-inch groups, respectively (P = 0.113). There were no significant differences in selective bile duct cannulation time (median ± interquartile range: 3.7 ± 13.9 min vs 4.0 ± 11.2 min for the 0.025-inch and 0.035-inch groups, respectively; P = 0.851), ERCP procedure time (median ± interquartile range: 32 ± 29 min vs 30 ± 25 min for the 0.025-inch and 0.035-inch groups, respectively; P = 0.184) or in the rate of pancreatic duct stent placement (14.7% vs 15.6% for the 0.025-inch and 0.035-inch groups, respectively; P = 0.832). The incidence of PEP was 2.8% (3/109) and 2.5% (4/160) for the 0.025-inch and 0.035-inch groups, respectively (P = 0.793). CONCLUSION: The thickness of the GW for WGC does not appear to affect either the success rate of selective bile duct cannulation or the incidence of PEP. PMID:26290646

Skin penetration operators' knowledge and attitudes towards infection control.

PubMed

Oberdorfer, Aurmporn; Wiggers, John H; Considine, Robyn J; Bowman, Jenny; Cockburn, Jill

2003-01-01

To assess the knowledge and attitudes of owners/managers of commercial skin-penetration premises regarding infection control. A telephone survey was conducted with a randomly selected sample of 874 owners/managers. Participants appeared to lack knowledge of essential infection-control practices. Less than 39% correctly identified recommended disinfection procedures, and between 12% to 67% were not aware of inappropriate sterlization procedures. Almost all participants accepted the need for guidelines. Half acknowledged a need to improve their infection-control compliance, and most accepted having their premises regularly checked by the councils. There is a considerable opportunity to increase infection-control compliance among skin-penetration operators.

How to Do Random Allocation (Randomization)

PubMed Central

Shin, Wonshik

2014-01-01

Purpose To explain the concept and procedure of random allocation as used in a randomized controlled study. Methods We explain the general concept of random allocation and demonstrate how to perform the procedure easily and how to report it in a paper. PMID:24605197

TRUNCATED RANDOM MEASURES

DTIC Science & Technology

2018-01-12

sequential representations, a method is required for deter- mining which to use for the application at hand and, once a representation is selected, for...DISTRIBUTION UNLIMITED Methods , Assumptions, and Procedures 3.1 Background 3.1.1 CRMs and truncation Consider a Poisson point process on R+ := [0...the heart of the study of truncated CRMs. They provide an itera- tive method that can be terminated at any point to yield a finite approximation to the

Interpretation of the results of statistical measurements. [search for basic probability model

NASA Technical Reports Server (NTRS)

Olshevskiy, V. V.

1973-01-01

For random processes, the calculated probability characteristic, and the measured statistical estimate are used in a quality functional, which defines the difference between the two functions. Based on the assumption that the statistical measurement procedure is organized so that the parameters for a selected model are optimized, it is shown that the interpretation of experimental research is a search for a basic probability model.

The Effects of a Simulation Game on Learning of Geographic Information at the Fifth Grade Level. Final Report.

ERIC Educational Resources Information Center

Keach, Everett T., Jr.; Pierfy, David A.

The research in this report was conducted to assess the cognitive impact of a simulation game designed to teach selected geographic data about wind and ocean currents to fifth graders. A two-group, post-test research design was used. A random procedure was used to assign 185 students to two treatment groups. The sample was divided by sex, ranked…

[Are there selection criteria between abdominal approach and vaginal route for genital prolapse surgical management?].

PubMed

Cour, F; Vidart, A

2016-07-01

The never ending debate over the surgical approach of genital prolapse repair (abdominal versus vaginal route) is as passionate as ever. The available literature may support a multidisciplinary analysis of our expert daily practice. Our purpose was to define selection criteria for surgical approach between abdominal and vaginal route in the management of genital prolapse by reviewing the literature. Systematically review of the literature concerning comparative anatomical and functionnal results of surgery of pelvic organ prolaps by vaginal or abdominal route. We were confronted to the lack of data in the literature, with few prospective randomized comparative studies. Many limitations were identified such as small populations in the studies, no description of sub-population, multiplicity of surgical procedures. Moreover, vaginal route was compared to sacral colpopexy by open abdominal approach, whereas laparoscopic sacrocolpopexy is now recommended. Only one prospective randomized comparative trial assessed laparoscopic sacrocolpopexy and vaginal approach, in which was used a mesh withdrawn from the market. The lack of available randomized trials makes it impossible to define HAS compliant guidelines on this topic. However, selection criteria for each surgical approach and technique were drawn from experts' advices. © 2016 Published by Elsevier Masson SAS. © 2016 Elsevier Masson SAS. Tous droits réservés.

Varying levels of difficulty index of skills-test items randomly selected by examinees on the Korean emergency medical technician licensing examination.

PubMed

Koh, Bongyeun; Hong, Sunggi; Kim, Soon-Sim; Hyun, Jin-Sook; Baek, Milye; Moon, Jundong; Kwon, Hayran; Kim, Gyoungyong; Min, Seonggi; Kang, Gu-Hyun

2016-01-01

The goal of this study was to characterize the difficulty index of the items in the skills test components of the class I and II Korean emergency medical technician licensing examination (KEMTLE), which requires examinees to select items randomly. The results of 1,309 class I KEMTLE examinations and 1,801 class II KEMTLE examinations in 2013 were subjected to analysis. Items from the basic and advanced skills test sections of the KEMTLE were compared to determine whether some were significantly more difficult than others. In the class I KEMTLE, all 4 of the items on the basic skills test showed significant variation in difficulty index (P<0.01), as well as 4 of the 5 items on the advanced skills test (P<0.05). In the class II KEMTLE, 4 of the 5 items on the basic skills test showed significantly different difficulty index (P<0.01), as well as all 3 of the advanced skills test items (P<0.01). In the skills test components of the class I and II KEMTLE, the procedure in which examinees randomly select questions should be revised to require examinees to respond to a set of fixed items in order to improve the reliability of the national licensing examination.

Autoshaping, random control, and omission training in the rat1

PubMed Central

Locurto, Charles; Terrace, H. S.; Gibbon, John

1976-01-01

The role of the stimulus-reinforcer contingency in the development and maintenance of lever contact responding was studied in hooded rats. In Experiment I, three groups of experimentally naive rats were trained either on autoshaping, omission training, or a random-control procedure. Subjects trained by the autoshaping procedure responded more consistently than did either random-control or omission-trained subjects. The probability of at least one lever contact per trial was slightly higher in subjects trained by the omission procedure than by the random-control procedure. However, these differences were not maintained during extended training, nor were they evident in total lever-contact frequencies. When omission and random-control subjects were switched to the autoshaping condition, lever contacts increased in all animals, but a pronounced retardation was observed in omission subjects relative to the random-control subjects. In addition, subjects originally exposed to the random-control procedure, and later switched to autoshaping, acquired more rapidly than naive subjects that were exposed only on the autoshaping procedure. In Experiment II, subjects originally trained by an autoshaping procedure were exposed either to an omission, a random-control, or an extinction procedure. No differences were observed among the groups either in the rate at which lever contacts decreased or in the frequency of lever contacts at the end of training. These data implicate prior experience in the interpretation of omission-training effects and suggest limitations in the influence of stimulus-reinforcer relations in autoshaping. PMID:16811960

Autoshaping, random control, and omission training in the rat.

PubMed

Locurto, C; Terrace, H S; Gibbon, J

1976-11-01

The role of the stimulus-reinforcer contingency in the development and maintenance of lever contact responding was studied in hooded rats. In Experiment I, three groups of experimentally naive rats were trained either on autoshaping, omission training, or a random-control procedure. Subjects trained by the autoshaping procedure responded more consistently than did either random-control or omission-trained subjects. The probability of at least one lever contact per trial was slightly higher in subjects trained by the omission procedure than by the random-control procedure. However, these differences were not maintained during extended training, nor were they evident in total lever-contact frequencies. When omission and random-control subjects were switched to the autoshaping condition, lever contacts increased in all animals, but a pronounced retardation was observed in omission subjects relative to the random-control subjects. In addition, subjects originally exposed to the random-control procedure, and later switched to autoshaping, acquired more rapidly than naive subjects that were exposed only on the autoshaping procedure. In Experiment II, subjects originally trained by an autoshaping procedure were exposed either to an omission, a random-control, or an extinction procedure. No differences were observed among the groups either in the rate at which lever contacts decreased or in the frequency of lever contacts at the end of training. These data implicate prior experience in the interpretation of omission-training effects and suggest limitations in the influence of stimulus-reinforcer relations in autoshaping.

Does Self-Selection Affect Samples’ Representativeness in Online Surveys? An Investigation in Online Video Game Research

PubMed Central

van Singer, Mathias; Chatton, Anne; Achab, Sophia; Zullino, Daniele; Rothen, Stephane; Khan, Riaz; Billieux, Joel; Thorens, Gabriel

2014-01-01

Background The number of medical studies performed through online surveys has increased dramatically in recent years. Despite their numerous advantages (eg, sample size, facilitated access to individuals presenting stigmatizing issues), selection bias may exist in online surveys. However, evidence on the representativeness of self-selected samples in online studies is patchy. Objective Our objective was to explore the representativeness of a self-selected sample of online gamers using online players’ virtual characters (avatars). Methods All avatars belonged to individuals playing World of Warcraft (WoW), currently the most widely used online game. Avatars’ characteristics were defined using various games’ scores, reported on the WoW’s official website, and two self-selected samples from previous studies were compared with a randomly selected sample of avatars. Results We used scores linked to 1240 avatars (762 from the self-selected samples and 478 from the random sample). The two self-selected samples of avatars had higher scores on most of the assessed variables (except for guild membership and exploration). Furthermore, some guilds were overrepresented in the self-selected samples. Conclusions Our results suggest that more proficient players or players more involved in the game may be more likely to participate in online surveys. Caution is needed in the interpretation of studies based on online surveys that used a self-selection recruitment procedure. Epidemiological evidence on the reduced representativeness of sample of online surveys is warranted. PMID:25001007

Constraints on the performance of minor surgery by family physicians: study of a 'mock' skin biopsy procedure.

PubMed

Rodney, W M; Richards, E; Ounanian, L L; Morrison, J D

1987-03-01

Despite the availability of a procedure room equipped for the performance of common surgery procedures, physicians in a family medicine training programme have reported that minor surgery training objectives are not being accomplished. To examine this issue, the frequency of minor surgery procedures was audited among 357 randomly selected medical records. The frequency of documented sigmoidoscopy in this group of active patients over the age of 50 years was 4.8%. A similar low frequency for the performance of skin biopsy was also observed. All 15 senior residents participated in an attitude survey and a timed exercise in which they sought to find the necessary items for performance of a skin biopsy. In a questionnaire the group agreed that sigmoidoscopy and skin biopsies were procedures appropriate for their family practice goals. In their offices, these residents required over nine minutes to partially locate equipment chosen for skin biopsy. The attitude survey revealed few constraints other than insufficient time to perform indicated elective procedures. Further study of procedure room utilization and family physicians' office surgery skills is recommended.

Refining a complex diagnostic construct: subtyping Dysthymia with the Shedler-Westen Assessment Procedure-II.

PubMed

Huprich, Steven K; Defife, Jared; Westen, Drew

2014-01-01

We sought to determine whether meaningful subtypes of Dysthymic patients could be identified when grouping them by similar personality profiles. A random, national sample of psychiatrists and clinical psychologists (n=1201) described a randomly selected current patient with personality pathology using the descriptors in the Shedler-Westen Assessment Procedure-II (SWAP-II), completed assessments of patients' adaptive functioning, and provided DSM-IV Axis I and II diagnoses. We applied Q-factor cluster analyses to those patients diagnosed with Dysthymic Disorder. Four clusters were identified-High Functioning, Anxious/Dysphoric, Emotionally Dysregulated, and Narcissistic. These factor scores corresponded with a priori hypotheses regarding diagnostic comorbidity and level of adaptive functioning. We compared these groups to diagnostic constructs described and empirically identified in the past literature. The results converge with past and current ideas about the ways in which chronic depression and personality are related and offer an enhanced means by which to understand a heterogeneous diagnostic category that is empirically grounded and clinically useful. © 2013 Published by Elsevier B.V.

Random Survival Forest in practice: a method for modelling complex metabolomics data in time to event analysis.

PubMed

Dietrich, Stefan; Floegel, Anna; Troll, Martina; Kühn, Tilman; Rathmann, Wolfgang; Peters, Anette; Sookthai, Disorn; von Bergen, Martin; Kaaks, Rudolf; Adamski, Jerzy; Prehn, Cornelia; Boeing, Heiner; Schulze, Matthias B; Illig, Thomas; Pischon, Tobias; Knüppel, Sven; Wang-Sattler, Rui; Drogan, Dagmar

2016-10-01

The application of metabolomics in prospective cohort studies is statistically challenging. Given the importance of appropriate statistical methods for selection of disease-associated metabolites in highly correlated complex data, we combined random survival forest (RSF) with an automated backward elimination procedure that addresses such issues. Our RSF approach was illustrated with data from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study, with concentrations of 127 serum metabolites as exposure variables and time to development of type 2 diabetes mellitus (T2D) as outcome variable. Out of this data set, Cox regression with a stepwise selection method was recently published. Replication of methodical comparison (RSF and Cox regression) was conducted in two independent cohorts. Finally, the R-code for implementing the metabolite selection procedure into the RSF-syntax is provided. The application of the RSF approach in EPIC-Potsdam resulted in the identification of 16 incident T2D-associated metabolites which slightly improved prediction of T2D when used in addition to traditional T2D risk factors and also when used together with classical biomarkers. The identified metabolites partly agreed with previous findings using Cox regression, though RSF selected a higher number of highly correlated metabolites. The RSF method appeared to be a promising approach for identification of disease-associated variables in complex data with time to event as outcome. The demonstrated RSF approach provides comparable findings as the generally used Cox regression, but also addresses the problem of multicollinearity and is suitable for high-dimensional data. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

Determination of the Optimal Chromosomal Location(s) for a DNA Element in Escherichia coli Using a Novel Transposon-mediated Approach.

PubMed

Frimodt-Møller, Jakob; Charbon, Godefroid; Krogfelt, Karen A; Løbner-Olesen, Anders

2017-09-11

The optimal chromosomal position(s) of a given DNA element was/were determined by transposon-mediated random insertion followed by fitness selection. In bacteria, the impact of the genetic context on the function of a genetic element can be difficult to assess. Several mechanisms, including topological effects, transcriptional interference from neighboring genes, and/or replication-associated gene dosage, may affect the function of a given genetic element. Here, we describe a method that permits the random integration of a DNA element into the chromosome of Escherichia coli and select the most favorable locations using a simple growth competition experiment. The method takes advantage of a well-described transposon-based system of random insertion, coupled with a selection of the fittest clone(s) by growth advantage, a procedure that is easily adjustable to experimental needs. The nature of the fittest clone(s) can be determined by whole-genome sequencing on a complex multi-clonal population or by easy gene walking for the rapid identification of selected clones. Here, the non-coding DNA region DARS2, which controls the initiation of chromosome replication in E. coli, was used as an example. The function of DARS2 is known to be affected by replication-associated gene dosage; the closer DARS2 gets to the origin of DNA replication, the more active it becomes. DARS2 was randomly inserted into the chromosome of a DARS2-deleted strain. The resultant clones containing individual insertions were pooled and competed against one another for hundreds of generations. Finally, the fittest clones were characterized and found to contain DARS2 inserted in close proximity to the original DARS2 location.

Method for nonlinear optimization for gas tagging and other systems

DOEpatents

Chen, Ting; Gross, Kenny C.; Wegerich, Stephan

1998-01-01

A method and system for providing nuclear fuel rods with a configuration of isotopic gas tags. The method includes selecting a true location of a first gas tag node, selecting initial locations for the remaining n-1 nodes using target gas tag compositions, generating a set of random gene pools with L nodes, applying a Hopfield network for computing on energy, or cost, for each of the L gene pools and using selected constraints to establish minimum energy states to identify optimal gas tag nodes with each energy compared to a convergence threshold and then upon identifying the gas tag node continuing this procedure until establishing the next gas tag node until all remaining n nodes have been established.

Method for nonlinear optimization for gas tagging and other systems

DOEpatents

Chen, T.; Gross, K.C.; Wegerich, S.

1998-01-06

A method and system are disclosed for providing nuclear fuel rods with a configuration of isotopic gas tags. The method includes selecting a true location of a first gas tag node, selecting initial locations for the remaining n-1 nodes using target gas tag compositions, generating a set of random gene pools with L nodes, applying a Hopfield network for computing on energy, or cost, for each of the L gene pools and using selected constraints to establish minimum energy states to identify optimal gas tag nodes with each energy compared to a convergence threshold and then upon identifying the gas tag node continuing this procedure until establishing the next gas tag node until all remaining n nodes have been established. 6 figs.

Handwashing with soap or alcoholic solutions? A randomized clinical trial of its effectiveness.

PubMed

Zaragoza, M; Sallés, M; Gomez, J; Bayas, J M; Trilla, A

1999-06-01

The effectiveness of an alcoholic solution compared with the standard hygienic handwashing procedure during regular work in clinical wards and intensive care units of a large public university hospital in Barcelona was assessed. A prospective, randomized clinical trial with crossover design, paired data, and blind evaluation was done. Eligible health care workers (HCWs) included permanent and temporary HCWs of wards and intensive care units. From each category, a random sample of persons was selected. HCWs were randomly assigned to regular handwashing (liquid soap and water) or handwashing with the alcoholic solution by using a crossover design. The number of colony-forming units on agar plates from hands printing in 3 different samples was counted. A total of 47 HCWs were included. The average reduction in the number of colony-forming units from samples before handwashing to samples after handwashing was 49.6% for soap and water and 88.2% for the alcoholic solution. When both methods were compared, the average number of colony-forming units recovered after the procedure showed a statistically significant difference in favor of the alcoholic solution (P <.001). The alcoholic solution was well tolerated by HCWs. Overall acceptance rate was classified as "good" by 72% of HCWs after 2 weeks use. Of all HCWs included, 9.3% stated that the use of the alcoholic solution worsened minor pre-existing skin conditions. Although the regular use of hygienic soap and water handwashing procedures is the gold standard, the use of alcoholic solutions is effective and safe and deserves more attention, especially in situations in which the handwashing compliance rate is hampered by architectural problems (lack of sinks) or nursing work overload.

An automatic optimum number of well-distributed ground control lines selection procedure based on genetic algorithm

NASA Astrophysics Data System (ADS)

Yavari, Somayeh; Valadan Zoej, Mohammad Javad; Salehi, Bahram

2018-05-01

The procedure of selecting an optimum number and best distribution of ground control information is important in order to reach accurate and robust registration results. This paper proposes a new general procedure based on Genetic Algorithm (GA) which is applicable for all kinds of features (point, line, and areal features). However, linear features due to their unique characteristics are of interest in this investigation. This method is called Optimum number of Well-Distributed ground control Information Selection (OWDIS) procedure. Using this method, a population of binary chromosomes is randomly initialized. The ones indicate the presence of a pair of conjugate lines as a GCL and zeros specify the absence. The chromosome length is considered equal to the number of all conjugate lines. For each chromosome, the unknown parameters of a proper mathematical model can be calculated using the selected GCLs (ones in each chromosome). Then, a limited number of Check Points (CPs) are used to evaluate the Root Mean Square Error (RMSE) of each chromosome as its fitness value. The procedure continues until reaching a stopping criterion. The number and position of ones in the best chromosome indicate the selected GCLs among all conjugate lines. To evaluate the proposed method, a GeoEye and an Ikonos Images are used over different areas of Iran. Comparing the obtained results by the proposed method in a traditional RFM with conventional methods that use all conjugate lines as GCLs shows five times the accuracy improvement (pixel level accuracy) as well as the strength of the proposed method. To prevent an over-parametrization error in a traditional RFM due to the selection of a high number of improper correlated terms, an optimized line-based RFM is also proposed. The results show the superiority of the combination of the proposed OWDIS method with an optimized line-based RFM in terms of increasing the accuracy to better than 0.7 pixel, reliability, and reducing systematic errors. These results also demonstrate the high potential of linear features as reliable control features to reach sub-pixel accuracy in registration applications.

The effect of music on preprocedure anxiety in Hong Kong Chinese day patients.

PubMed

Lee, David; Henderson, Amanda; Shum, David

2004-03-01

To identify the effect of music on preprocedure anxiety levels of Hong Kong Chinese patients undergoing day procedures in a local community based hospital. Pre and post-test quasi experimental design with non-random assignment. A total of 113 participants were assigned to the control group or intervention group depending on the day of their procedure. Participants' anxiety levels were measured objectively by comparing their vital signs and subjectively by the Spielberger State Trait Anxiety Scale. Participants' physiological parameters (blood pressure, pulse and respiration) and State Trait Anxiety Scale were measured at two time periods. The control group undertook the usual relaxing activities provided in the waiting room compared with the intervention group who listened to music of their own choice in reclining chairs while waiting for the procedure. The physiological parameters for both the control and intervention groups dropped significantly during the waiting period, however, only the intervention group had a significant reduction in reported anxiety levels. These results suggest that providing self-selected music to day procedure patients in the preprocedure period assists in the reduction of physiological parameters and anxiety, yet, a relaxing environment can assist in the reduction of physiological parameters. The administration of self-selected music to day procedure patients in the preprocedure period can be effective in the reduction of physiological parameters and anxiety.

Inter-rater agreement among orthodontists in a blocked experiment.

PubMed

Korn, E L; Baumrind, S

1985-01-01

Five orthodontists were asked to predict for 64 patients a particular dichotomous outcome of treatment based on pre-treatment X-ray films. The orthodontists rated the cases in blocks of size 4-6 with the knowledge of the number of positive outcomes in each block. We discuss the reasons why this blocked design is appropriate whenever clinicians are asked to rate cases which have not been randomly selected from a clinical practice similar to their own. We give a simple description of the inter-rater agreement for this type of blocked experiment as well as a procedure to test that the agreement is no better than that expected by random independent assignment.

Efficient one-cycle affinity selection of binding proteins or peptides specific for a small-molecule using a T7 phage display pool.

PubMed

Takakusagi, Yoichi; Kuramochi, Kouji; Takagi, Manami; Kusayanagi, Tomoe; Manita, Daisuke; Ozawa, Hiroko; Iwakiri, Kanako; Takakusagi, Kaori; Miyano, Yuka; Nakazaki, Atsuo; Kobayashi, Susumu; Sugawara, Fumio; Sakaguchi, Kengo

2008-11-15

Here, we report an efficient one-cycle affinity selection using a natural-protein or random-peptide T7 phage pool for identification of binding proteins or peptides specific for small-molecules. The screening procedure involved a cuvette type 27-MHz quartz-crystal microbalance (QCM) apparatus with introduction of self-assembled monolayer (SAM) for a specific small-molecule immobilization on the gold electrode surface of a sensor chip. Using this apparatus, we attempted an affinity selection of proteins or peptides against synthetic ligand for FK506-binding protein (SLF) or irinotecan (Iri, CPT-11). An affinity selection using SLF-SAM and a natural-protein T7 phage pool successfully detected FK506-binding protein 12 (FKBP12)-displaying T7 phage after an interaction time of only 10 min. Extensive exploration of time-consuming wash and/or elution conditions together with several rounds of selection was not required. Furthermore, in the selection using a 15-mer random-peptide T7 phage pool and subsequent analysis utilizing receptor ligand contact (RELIC) software, a subset of SLF-selected peptides clearly pinpointed several amino-acid residues within the binding site of FKBP12. Likewise, a subset of Iri-selected peptides pinpointed part of the positive amino-acid region of residues from the Iri-binding site of the well-known direct targets, acetylcholinesterase (AChE) and carboxylesterase (CE). Our findings demonstrate the effectiveness of this method and general applicability for a wide range of small-molecules.

Chain Pooling modeling selection as developed for the statistical analysis of a rotor burst protection experiment

NASA Technical Reports Server (NTRS)

Holms, A. G.

1977-01-01

As many as three iterated statistical model deletion procedures were considered for an experiment. Population model coefficients were chosen to simulate a saturated 2 to the 4th power experiment having an unfavorable distribution of parameter values. Using random number studies, three model selection strategies were developed, namely, (1) a strategy to be used in anticipation of large coefficients of variation, approximately 65 percent, (2) a strategy to be sued in anticipation of small coefficients of variation, 4 percent or less, and (3) a security regret strategy to be used in the absence of such prior knowledge.

A machine learning methodology for the selection and classification of spontaneous spinal cord dorsum potentials allows disclosure of structured (non-random) changes in neuronal connectivity induced by nociceptive stimulation

PubMed Central

Martin, Mario; Contreras-Hernández, Enrique; Béjar, Javier; Esposito, Gennaro; Chávez, Diógenes; Glusman, Silvio; Cortés, Ulises; Rudomin, Pablo

2015-01-01

Previous studies aimed to disclose the functional organization of the neuronal networks involved in the generation of the spontaneous cord dorsum potentials (CDPs) generated in the lumbosacral spinal segments used predetermined templates to select specific classes of spontaneous CDPs. Since this procedure was time consuming and required continuous supervision, it was limited to the analysis of two specific types of CDPs (negative CDPs and negative positive CDPs), thus excluding potentials that may reflect activation of other neuronal networks of presumed functional relevance. We now present a novel procedure based in machine learning that allows the efficient and unbiased selection of a variety of spontaneous CDPs with different shapes and amplitudes. The reliability and performance of the present method is evaluated by analyzing the effects on the probabilities of generation of different classes of spontaneous CDPs induced by the intradermic injection of small amounts of capsaicin in the anesthetized cat, a procedure known to induce a state of central sensitization leading to allodynia and hyperalgesia. The results obtained with the selection method presently described allowed detection of spontaneous CDPs with specific shapes and amplitudes that are assumed to represent the activation of functionally coupled sets of dorsal horn neurones that acquire different, structured configurations in response to nociceptive stimuli. These changes are considered as responses tending to adequate transmission of sensory information to specific functional requirements as part of homeostatic adjustments. PMID:26379540

Virtual Reality as a Distraction Intervention to Relieve Pain and Distress During Medical Procedures: A Comprehensive Literature Review.

PubMed

Indovina, Paola; Barone, Daniela; Gallo, Luigi; Chirico, Andrea; De Pietro, Giuseppe; Antonio, Giordano

2018-02-26

This review aims to provide a framework for evaluating the utility of virtual reality (VR) as a distraction intervention to alleviate pain and distress during medical procedures. We firstly describe the theoretical bases underlying the VR analgesic and anxiolytic effects and define the main factors contributing to its efficacy, which largely emerged from studies on healthy volunteers. Then, we provide a comprehensive overview of the clinical trials using VR distraction during different medical procedures, such as burn injury treatments, chemotherapy, surgery, dental treatment, and other diagnostic and therapeutic procedures. A broad literature search was performed using as main terms "virtual reality", "distraction" and "pain". No date limit was applied and all the retrieved studies on immersive VR distraction during medical procedures were selected. VR has proven to be effective in reducing procedural pain, as almost invariably observed even in patients subjected to extremely painful procedures, such as patients with burn injuries undergoing wound care and physical therapy. Moreover, VR seemed to decrease cancer-related symptoms in different settings, including during chemotherapy. Only mild and infrequent side effects were observed. Despite these promising results, future long-term randomized controlled trials with larger sample sizes and evaluating not only self-report measures but also physiological variables are needed. Further studies are also required both to establish predictive factors to select patients who can benefit from VR distraction and to design hardware/software systems tailored to the specific needs of different patients and able to provide the greatest distraction at the lowest cost.

Assessing the accuracy and stability of variable selection ...

EPA Pesticide Factsheets

Random forest (RF) modeling has emerged as an important statistical learning method in ecology due to its exceptional predictive performance. However, for large and complex ecological datasets there is limited guidance on variable selection methods for RF modeling. Typically, either a preselected set of predictor variables are used, or stepwise procedures are employed which iteratively add/remove variables according to their importance measures. This paper investigates the application of variable selection methods to RF models for predicting probable biological stream condition. Our motivating dataset consists of the good/poor condition of n=1365 stream survey sites from the 2008/2009 National Rivers and Stream Assessment, and a large set (p=212) of landscape features from the StreamCat dataset. Two types of RF models are compared: a full variable set model with all 212 predictors, and a reduced variable set model selected using a backwards elimination approach. We assess model accuracy using RF's internal out-of-bag estimate, and a cross-validation procedure with validation folds external to the variable selection process. We also assess the stability of the spatial predictions generated by the RF models to changes in the number of predictors, and argue that model selection needs to consider both accuracy and stability. The results suggest that RF modeling is robust to the inclusion of many variables of moderate to low importance. We found no substanti

Varying levels of difficulty index of skills-test items randomly selected by examinees on the Korean emergency medical technician licensing examination

PubMed Central

2016-01-01

Purpose: The goal of this study was to characterize the difficulty index of the items in the skills test components of the class I and II Korean emergency medical technician licensing examination (KEMTLE), which requires examinees to select items randomly. Methods: The results of 1,309 class I KEMTLE examinations and 1,801 class II KEMTLE examinations in 2013 were subjected to analysis. Items from the basic and advanced skills test sections of the KEMTLE were compared to determine whether some were significantly more difficult than others. Results: In the class I KEMTLE, all 4 of the items on the basic skills test showed significant variation in difficulty index (P<0.01), as well as 4 of the 5 items on the advanced skills test (P<0.05). In the class II KEMTLE, 4 of the 5 items on the basic skills test showed significantly different difficulty index (P<0.01), as well as all 3 of the advanced skills test items (P<0.01). Conclusion: In the skills test components of the class I and II KEMTLE, the procedure in which examinees randomly select questions should be revised to require examinees to respond to a set of fixed items in order to improve the reliability of the national licensing examination. PMID:26883810

Music therapy improves the mood of patients undergoing hematopoietic stem cells transplantation (controlled randomized study).

PubMed

Dóro, Carlos Antonio; Neto, José Zanis; Cunha, Rosemyriam; Dóro, Maribel Pelaez

2017-03-01

The allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a therapeutic medical treatment for various neoplastic hematologic, congenital, genetic, or acquired disorders. In this procedure which combines high-dose chemotherapy and/or radiotherapy and has a high degree of cytotoxicity, the patient experiences solitary confinement, which causes psychological distress, pain, anxiety, mood disorders and can lead him/her to depression. Music therapy was applied with the purpose of decreasing this social confinement. This is a randomized controlled trial. Patients (n = 100) were selected randomly. Patients (n = 50) were selected for the Experimental Music Therapy Group (EMG) and n = 50 for the control group (CG) who received the standard treatment. The intervention of live music was applied using music therapy techniques. Assessment and quantification were made using the visual analog scale (VAS). The dependent variables were pain, anxiety, and mood of patients. The Mann-Whitney test (p < 0.05) applied was considered statistically significant when comparing the groups, improving mood significantly (EMG). Music therapy proved to be a strong ally in the treatment of patients undergoing allo-HSCT, providing bio-psychosocial welfare.

Effect of the video output of the dental operating microscope on anxiety levels in a pediatric population during restorative procedures.

PubMed

Sayed, Abrar; Ranna, Vinisha; Padawe, Dimple; Takate, Vilas

2016-01-01

Adapting a child to the alien settings of a dental operatory is a major challenge to the dentist. Fear of the unknown and preconceived notions of dental pain causes anxiety in the pediatric patient. This often leads to disruptive and uncooperative behavior in the dental operatory. Many methods of behavior management have been described, of which the Tell-Show-Do (TSD) is an established and time-tested technique of behavior management. To determine if a live visual output of the dental operating microscope (DOM) could be used as an adjunct to the TSD technique, to involve the child more completely in the procedure and reduce the fear of the unknown. The study was a randomized, controlled, crossover, and cross-sectional clinical trial. Data were obtained from two visits. 90 children having carious lesions on both lower first molars, in the 7-9 years age group were selected and divided randomly into two groups. Restorative procedures were performed on one tooth per visit, with visits 1 week apart. Live display of the procedure was shown to the patient using video output of the DOM displayed on a 72 inch LCD monitor, angled for best visibility of the child. Anxiety levels were evaluated using Venhams picture selection test and pulse oximetry. Student's t-test was used to compare the anxiety scores obtained from the two groups. The results showed there was a decrease in the anxiety from the first visit to the second visit. (P = 0.05 for Group A and P = 0.003 for Group B). The patients preferred the visit in which the DOM was used. The operator reported an increased patient compliance and reduced patient movement in the visits in which the DOM was used. There is a reduction in anxiety from the first visit to the second visit for restorative treatment when the DOM is used.

Procedural and Physical Interventions for Vaccine Injections: Systematic Review of Randomized Controlled Trials and Quasi-Randomized Controlled Trials.

PubMed

Taddio, Anna; Shah, Vibhuti; McMurtry, C Meghan; MacDonald, Noni E; Ipp, Moshe; Riddell, Rebecca Pillai; Noel, Melanie; Chambers, Christine T

2015-10-01

This systematic review evaluated the effectiveness of physical and procedural interventions for reducing pain and related outcomes during vaccination. Databases were searched using a broad search strategy to identify relevant randomized and quasi-randomized controlled trials. Data were extracted according to procedure phase (preprocedure, acute, recovery, and combinations of these) and pooled using established methods. A total of 31 studies were included. Acute infant distress was diminished during intramuscular injection without aspiration (n=313): standardized mean difference (SMD) -0.82 (95% confidence interval [CI]: -1.18, -0.46). Injecting the most painful vaccine last during vaccinations reduced acute infant distress (n=196): SMD -0.69 (95% CI: -0.98, -0.4). Simultaneous injections reduced acute infant distress compared with sequential injections (n=172): SMD -0.56 (95% CI: -0.87, -0.25). There was no benefit of simultaneous injections in children. Less infant distress during the acute and recovery phases combined occurred with vastus lateralis (vs. deltoid) injections (n=185): SMD -0.70 (95% CI: -1.00, -0.41). Skin-to-skin contact in neonates (n=736) reduced acute distress: SMD -0.65 (95% CI: -1.05, -0.25). Holding infants reduced acute distress after removal of the data from 1 methodologically diverse study (n=107): SMD -1.25 (95% CI: -2.05, -0.46). Holding after vaccination (n=417) reduced infant distress during the acute and recovery phases combined: SMD -0.65 (95% CI: -1.08, -0.22). Self-reported fear was reduced for children positioned upright (n=107): SMD -0.39 (95% CI: -0.77, -0.01). Non-nutritive sucking (n=186) reduced acute distress in infants: SMD -1.88 (95% CI: -2.57, -1.18). Manual tactile stimulation did not reduce pain across the lifespan. An external vibrating device and cold reduced pain in children (n=145): SMD -1.23 (95% CI: -1.58, -0.87). There was no benefit of warming the vaccine in adults. Muscle tension was beneficial in selected indices of fainting in adolescents and adults. Interventions with evidence of benefit in select populations include: no aspiration, injecting most painful vaccine last, simultaneous injections, vastus lateralis injection, positioning interventions, non-nutritive sucking, external vibrating device with cold, and muscle tension.

Random-effects meta-analysis: the number of studies matters.

PubMed

Guolo, Annamaria; Varin, Cristiano

2017-06-01

This paper investigates the impact of the number of studies on meta-analysis and meta-regression within the random-effects model framework. It is frequently neglected that inference in random-effects models requires a substantial number of studies included in meta-analysis to guarantee reliable conclusions. Several authors warn about the risk of inaccurate results of the traditional DerSimonian and Laird approach especially in the common case of meta-analysis involving a limited number of studies. This paper presents a selection of likelihood and non-likelihood methods for inference in meta-analysis proposed to overcome the limitations of the DerSimonian and Laird procedure, with a focus on the effect of the number of studies. The applicability and the performance of the methods are investigated in terms of Type I error rates and empirical power to detect effects, according to scenarios of practical interest. Simulation studies and applications to real meta-analyses highlight that it is not possible to identify an approach uniformly superior to alternatives. The overall recommendation is to avoid the DerSimonian and Laird method when the number of meta-analysis studies is modest and prefer a more comprehensive procedure that compares alternative inferential approaches. R code for meta-analysis according to all of the inferential methods examined in the paper is provided.

Reward and uncertainty in exploration programs

NASA Technical Reports Server (NTRS)

Kaufman, G. M.; Bradley, P. G.

1971-01-01

A set of variables which are crucial to the economic outcome of petroleum exploration are discussed. These are treated as random variables; the values they assume indicate the number of successes that occur in a drilling program and determine, for a particular discovery, the unit production cost and net economic return if that reservoir is developed. In specifying the joint probability law for those variables, extreme and probably unrealistic assumptions are made. In particular, the different random variables are assumed to be independently distributed. Using postulated probability functions and specified parameters, values are generated for selected random variables, such as reservoir size. From this set of values the economic magnitudes of interest, net return and unit production cost are computed. This constitutes a single trial, and the procedure is repeated many times. The resulting histograms approximate the probability density functions of the variables which describe the economic outcomes of an exploratory drilling program.

Application of GIS-based Procedure on Slopeland Use Classification and Identification

NASA Astrophysics Data System (ADS)

KU, L. C.; LI, M. C.

2016-12-01

In Taiwan, the "Slopeland Conservation and Utilization Act" regulates the management of the slopelands. It categorizes the slopeland into land suitable for agricultural or animal husbandry, land suitable for forestry and land for enhanced conservation, according to the environmental factors of average slope, effective soil depth, soil erosion and parental rock. Traditionally, investigations of environmental factors require cost-effective field works. It has been confronted with many practical issues such as non-evaluated cadastral parcels, evaluation results depending on expert's opinion, difficulties in field measurement and judgment, and time consuming. This study aimed to develop a GIS-based procedure involved in the acceleration of slopeland use classification and quality improvement. First, the environmental factors of slopelands were analyzed by GIS and SPSS software. The analysis involved with the digital elevation model (DEM), soil depth map, land use map and satellite images. Second, 5% of the analyzed slopelands were selected to perform the site investigations and correct the results of classification. Finally, a 2nd examination was involved by randomly selected 2% of the analyzed slopelands to perform the accuracy evaluation. It was showed the developed procedure is effective in slopeland use classification and identification. Keywords: Slopeland Use Classification, GIS, Management

The effects of control of thermal balance on vascular stability in hemodialysis patients: results of the European randomized clinical trial.

PubMed

Maggiore, Quirino; Pizzarelli, Francesco; Santoro, Antonio; Panzetta, Giovanni; Bonforte, Giuseppe; Hannedouche, Thierry; Alvarez de Lara, Maria Antonia; Tsouras, Ioannis; Loureiro, Alfredo; Ponce, Pedro; Sulkovà, Sylvie; Van Roost, Guido; Brink, Hans; Kwan, Jonathan T C

2002-08-01

Many reports note that the use of cool dialysate has a protective effect on blood pressure during hemodialysis (HD) treatments. However, formal clinical trials in which dialysate temperature is tailored to the body temperature of appropriately selected hypotension-prone patients are lacking. We investigated the effect of thermal control of dialysate on hemodynamic stability in hypotension-prone patients selected from 27 centers in nine European countries. Patients were eligible for the study if they had symptomatic hypotensive episodes in 25% or more of their HD sessions, assessed during a prospective screening phase over 1 month. The study is designed as a randomized crossover trial with two phases and two treatment arms, each phase lasting 4 weeks. We used a device allowing the regulation of thermal balance (Blood Temperature Monitor; Fresenius Medical Care, Bad Homberg, Germany), by which we compared a procedure aimed at preventing any transfer of thermal energy between dialysate and extracorporeal blood (thermoneutral dialysis) with a procedure aimed at keeping body temperature unchanged (isothermic dialysis). One hundred sixteen HD patients were enrolled, and 95 patients completed the study. During thermoneutral dialysis (energy flow rate: DeltaE = -0.22 +/- 0.29 kJ/kg x h), 6 of 12 treatments (median) were complicated by hypotension, whereas during isothermic dialysis (energy flow rate: DeltaE = -0.90 +/- 0.35 kJ/kg x h), the median decreased to 3 of 12 treatments (P < 0.001). Systolic and diastolic blood pressures and heart rate were more stable during the latter procedure. Isothermic dialysis was well tolerated by patients. Results show that active control of body temperature can significantly improve intradialytic tolerance in hypotension-prone patients. Copyright 2002 by the National Kidney Foundation, Inc.

Evidence Synthesis in Harm Assessment of Medicines Using the Example of Rosiglitazone and Myocardial Infarction.

PubMed

Rietbergen, Charlotte; Stefansdottir, Gudrun; Leufkens, Hubert G; Knol, Mirjam J; De Bruin, Marie L; Klugkist, Irene

2017-01-01

The current system of harm assessment of medicines has been criticized for relying on intuitive expert judgment. There is a call for more quantitative approaches and transparency in decision-making. Illustrated with the case of cardiovascular safety concerns for rosiglitazone, we aimed to explore a structured procedure for the collection, quality assessment, and statistical modeling of safety data from observational and randomized studies. We distinguished five stages in the synthesis process. In Stage I, the general research question, population and outcome, and general inclusion and exclusion criteria are defined and a systematic search is performed. Stage II focusses on the identification of sub-questions examined in the included studies and the classification of the studies into the different categories of sub-questions. In Stage III, the quality of the identified studies is assessed. Coding and data extraction are performed in Stage IV. Finally, meta-analyses on the study results per sub-question are performed in Stage V. A Pubmed search identified 30 randomized and 14 observational studies meeting our search criteria. From these studies, we identified 4 higher level sub-questions and 4 lower level sub-questions. We were able to categorize 29 individual treatment comparisons into one or more of the sub-question categories, and selected study duration as an important covariate. We extracted covariate, outcome, and sample size information at the treatment arm level of the studies. We extracted absolute numbers of myocardial infarctions from the randomized study, and adjusted risk estimates with 95% confidence intervals from the observational studies. Overall, few events were observed in the randomized studies that were frequently of relatively short duration. The large observational studies provided more information since these were often of longer duration. A Bayesian random effects meta-analysis on these data showed no significant increase in risk of rosiglitazone for any of the sub-questions. The proposed procedure can be of additional value for drug safety assessment because it provides a stepwise approach that guides the decision-making in increasing process transparency. The procedure allows for the inclusion of results from both randomized an observational studies, which is especially relevant for this type of research.

Variable Selection for Regression Models of Percentile Flows

NASA Astrophysics Data System (ADS)

Fouad, G.

2017-12-01

Percentile flows describe the flow magnitude equaled or exceeded for a given percent of time, and are widely used in water resource management. However, these statistics are normally unavailable since most basins are ungauged. Percentile flows of ungauged basins are often predicted using regression models based on readily observable basin characteristics, such as mean elevation. The number of these independent variables is too large to evaluate all possible models. A subset of models is typically evaluated using automatic procedures, like stepwise regression. This ignores a large variety of methods from the field of feature (variable) selection and physical understanding of percentile flows. A study of 918 basins in the United States was conducted to compare an automatic regression procedure to the following variable selection methods: (1) principal component analysis, (2) correlation analysis, (3) random forests, (4) genetic programming, (5) Bayesian networks, and (6) physical understanding. The automatic regression procedure only performed better than principal component analysis. Poor performance of the regression procedure was due to a commonly used filter for multicollinearity, which rejected the strongest models because they had cross-correlated independent variables. Multicollinearity did not decrease model performance in validation because of a representative set of calibration basins. Variable selection methods based strictly on predictive power (numbers 2-5 from above) performed similarly, likely indicating a limit to the predictive power of the variables. Similar performance was also reached using variables selected based on physical understanding, a finding that substantiates recent calls to emphasize physical understanding in modeling for predictions in ungauged basins. The strongest variables highlighted the importance of geology and land cover, whereas widely used topographic variables were the weakest predictors. Variables suffered from a high degree of multicollinearity, possibly illustrating the co-evolution of climatic and physiographic conditions. Given the ineffectiveness of many variables used here, future work should develop new variables that target specific processes associated with percentile flows.

Renal access in PNL under sonographic guidance: Do we really need to insert an open end ureteral catheter in dilated renal systems? A prospective randomized study.

PubMed

Eryildirim, Bilal; Tuncer, Murat; Camur, Emre; Ustun, Fatih; Tarhan, Fatih; Sarica, Kemal

2017-10-03

To evaluate the true necessity of open end ureteral catheter insertion in patients with moderate to severe pelvicalyceal system dilation treated with percutaneous nephrolithotomy (PNL) under sonographic guidance. 50 cases treated with PNL under sonographic guidance in prone position for solitary obstructing renal stones were evaluated. Patients were randomly divided into two groups; Group 1: Patients in whom a open end ureteral catheter was inserted prior to the procedure; Group 2: Patients receiving no catheter before PNL. In addition to the duration of the procedure as a whole and also all relevant stages as well, radiation exposure time, hospitalization period, mean nephrostomy tube duration, mean drop in Hb levels and all intra and postoperative complications have been evaluated. Mean size of the stones was 308.5 ± 133.2 mm2. Mean total duration of the PNL procedure in cases with open end ureteral catheter was significantly longer than the other cases (p < 0.001). Evaluation of the outcomes of the PNL procedures revealed no statistically significant difference between two groups regarding the stone-free rates (86% vs 84%). Additionally, there was no significant difference with respect to the duration of nephrostomy tube, hospitalization period and secondary procedures needed, complication rates as well as the post-operative Hb drop levels in both groups (p = 0.6830). Our results indicate that the placement of an open end ureteral catheter prior to a PNL procedure performed under sonographic access may not be indicated in selected cases presenting with solitary obstructing renal pelvic and/or calyceal stones.

Renal denervation in the management of resistant hypertension: current evidence and perspectives.

PubMed

Jin, Yu; Persu, Alexandre; Staessen, Jan A

2013-09-01

Catheter-based renal denervation has emerged as a novel treatment modality for resistant hypertension. This review summarizes the current evidence on this procedure in treatment of resistant hypertension, limitations of available evidence and questions to be answered. The SYMPLICITY studies showed that renal denervation is feasible in treating resistant hypertension, but failed to provide conclusive evidence on the size and durability of the antihypertensive, renal and sympatholytic effects, as well as the long-term safety. The definition of resistant hypertension was loose in the SYMPLICITY studies and the management of resistant hypertension was suboptimal. Future studies should have a randomized design and enroll truly resistant hypertension patients by excluding secondary hypertension, white-coat hypertension and nonadherent patients. Questions to be addressed by the ongoing and future trials include the long-term efficacy and safety of this procedure, identification of responders and uncovering of the underlying mechanisms. Only well-designed, randomized clinical trials addressing the limitations of the SYMPLICITY studies will be able to demonstrate whether renal denervation is an efficacious treatment modality in resistant hypertension and in which patients. For now, renal denervation remains an experimental procedure and should only be offered to truly resistant hypertensive patients in a research context after careful selection.

A Bayesian random effects discrete-choice model for resource selection: Population-level selection inference

USGS Publications Warehouse

Thomas, D.L.; Johnson, D.; Griffith, B.

2006-01-01

Modeling the probability of use of land units characterized by discrete and continuous measures, we present a Bayesian random-effects model to assess resource selection. This model provides simultaneous estimation of both individual- and population-level selection. Deviance information criterion (DIC), a Bayesian alternative to AIC that is sample-size specific, is used for model selection. Aerial radiolocation data from 76 adult female caribou (Rangifer tarandus) and calf pairs during 1 year on an Arctic coastal plain calving ground were used to illustrate models and assess population-level selection of landscape attributes, as well as individual heterogeneity of selection. Landscape attributes included elevation, NDVI (a measure of forage greenness), and land cover-type classification. Results from the first of a 2-stage model-selection procedure indicated that there is substantial heterogeneity among cow-calf pairs with respect to selection of the landscape attributes. In the second stage, selection of models with heterogeneity included indicated that at the population-level, NDVI and land cover class were significant attributes for selection of different landscapes by pairs on the calving ground. Population-level selection coefficients indicate that the pairs generally select landscapes with higher levels of NDVI, but the relationship is quadratic. The highest rate of selection occurs at values of NDVI less than the maximum observed. Results for land cover-class selections coefficients indicate that wet sedge, moist sedge, herbaceous tussock tundra, and shrub tussock tundra are selected at approximately the same rate, while alpine and sparsely vegetated landscapes are selected at a lower rate. Furthermore, the variability in selection by individual caribou for moist sedge and sparsely vegetated landscapes is large relative to the variability in selection of other land cover types. The example analysis illustrates that, while sometimes computationally intense, a Bayesian hierarchical discrete-choice model for resource selection can provide managers with 2 components of population-level inference: average population selection and variability of selection. Both components are necessary to make sound management decisions based on animal selection.

Alcohol- and Drug-Involved Driving in the United States: Methodology for the 2007 National Roadside Survey

PubMed Central

Lacey, John H.; Kelley-Baker, Tara; Voas, Robert B.; Romano, Eduardo; Furr-Holden, C. Debra; Torres, Pedro; Berning, Amy

2013-01-01

This article describes the methodology used in the 2007 U.S. National Roadside Survey to estimate the prevalence of alcohol- and drug-impaired driving and alcohol- and drug-involved driving. This study involved randomly stopping drivers at 300 locations across the 48 continental U.S. states at sites selected through a stratified random sampling procedure. Data were collected during a 2-hour Friday daytime session at 60 locations and during 2-hour nighttime weekend periods at 240 locations. Both self-report and biological measures were taken. Biological measures included breath alcohol measurements from 9,413 respondents, oral fluid samples from 7,719 respondents, and blood samples from 3,276 respondents. PMID:21997324

Randomization Procedures Applied to Analysis of Ballistic Data

DTIC Science & Technology

1991-06-01

test,;;15. NUMBER OF PAGES data analysis; computationally intensive statistics ; randomization tests; permutation tests; 16 nonparametric statistics ...be 0.13. 8 Any reasonable statistical procedure would fail to support the notion of improvement of dynamic over standard indexing based on this data ...AD-A238 389 TECHNICAL REPORT BRL-TR-3245 iBRL RANDOMIZATION PROCEDURES APPLIED TO ANALYSIS OF BALLISTIC DATA MALCOLM S. TAYLOR BARRY A. BODT - JUNE

Modeling Training Site Vegetation Coverage Probability with a Random Optimizing Procedure: An Artificial Neural Network Approach.

DTIC Science & Technology

1998-05-01

Coverage Probability with a Random Optimization Procedure: An Artificial Neural Network Approach by Biing T. Guan, George Z. Gertner, and Alan B...Modeling Training Site Vegetation Coverage Probability with a Random Optimizing Procedure: An Artificial Neural Network Approach 6. AUTHOR(S) Biing...coverage based on past coverage. Approach A literature survey was conducted to identify artificial neural network analysis techniques applicable for

Policies and procedures in the workplace: how health care organizations compare.

PubMed

Loo, R

1993-01-01

Many organizations are implementing programs and services to manage the human and economic costs of stress. A mail survey was conducted of 500 randomly selected Canadian organizations having at least 500 employees. The survey tapped four major areas: organizational policies and procedures for managing stress; programs and services offered; perceived benefits and constraints for the organization; and projected future directions in this area. Analyses of returns from 210 organizations-43 health and 167 non-health-revealed various findings. For example, over half of health care organizations have policies and procedures as opposed to less than half of non-health care organizations. Also, health care organizations place greater emphasis on smoking cessation, weight control programs and on stress management training. Although some Canadian organizations are addressing stress, much more could and should be done, especially by organizations that do not yet recognize the impact of stress on employees and their work performance.

Acute changes of hip joint range of motion using selected clinical stretching procedures: A randomized crossover study.

PubMed

Hammer, Adam M; Hammer, Roger L; Lomond, Karen V; O'Connor, Paul

2017-12-01

Hip adductor flexibility and strength is an important component of athletic performance and many activities of daily living. Little research has been done on the acute effects of a single session of stretching on hip abduction range of motion (ROM). The aim of this study was to compare 3 clinical stretching procedures against passive static stretching and control on ROM and peak isometric maximal voluntary contraction (MVC). Using a randomized crossover study design, a total of 40 participants (20 male and 20 female) who had reduced hip adductor muscle length attended a familiarization session and 5 testing sessions on non-consecutive days. Following the warm-up and pre-intervention measures of ROM and MVC, participants were randomly assigned 1 of 3 clinical stretching procedures (modified lunge, multidirectional, and joint mobilization) or a static stretch or control condition. Post-intervention measures of ROM and MVC were taken immediately following completion of the assigned condition. An ANOVA using a repeated measure design with the change score was conducted. All interventions resulted in small but statistically significant (p < 0.05) increases (1.0°-1.7°) in ROM with no inter-condition differences except one. Multidirectional stretching was greater than control (p = 0.031). These data suggest that a single session of stretching has only a minimal effect on acute changes of hip abduction ROM. Although hip abduction is a frontal plane motion, to effectively increase the extensibility of the structures that limit abduction, integrating multi-planar stretches may be indicated. Copyright © 2017 Elsevier Ltd. All rights reserved.

The efficacy of virtual reality simulation training in laparoscopy: a systematic review of randomized trials.

PubMed

Larsen, Christian Rifbjerg; Oestergaard, Jeanett; Ottesen, Bent S; Soerensen, Jette Led

2012-09-01

Virtual reality (VR) simulators for surgical training might possess the properties needed for basic training in laparoscopy. Evidence for training efficacy of VR has been investigated by research of varying quality over the past decade. To review randomized controlled trials regarding VR training efficacy compared with traditional or no training, with outcome measured as surgical performance in humans or animals. In June 2011 Medline, Embase, the Cochrane Central Register of Controlled Trials, Web of Science and Google Scholar were searched using the following medical subject headings (MeSh) terms: Laparoscopy/standards, Computing methodologies, Programmed instruction, Surgical procedures, Operative, and the following free text terms: Virtual real* OR simulat* AND Laparoscop* OR train* Controlled trials. All randomized controlled trials investigating the effect of VR training in laparoscopy, with outcome measured as surgical performance. A total of 98 studies were screened, 26 selected and 12 included, with a total of 241 participants. Operation time was reduced by 17-50% by VR training, depending on simulator type and training principles. Proficiency-based training appeared superior to training based on fixed time or fixed numbers of repetition. Simulators offering training for complete operative procedures came out as more efficient than simulators offering only basic skills training. Skills in laparoscopic surgery can be increased by proficiency-based procedural VR simulator training. There is substantial evidence (grade IA - IIB) to support the use of VR simulators in laparoscopic training. © 2012 The Authors  Acta Obstetricia et Gynecologica Scandinavica© 2012 Nordic Federation of Societies of Obstetrics and Gynecology.

Residual anastomoses in twin-twin transfusion syndrome after laser: the Solomon randomized trial.

PubMed

Slaghekke, Femke; Lewi, Liesbeth; Middeldorp, Johanna M; Weingertner, Anne Sophie; Klumper, Frans J; Dekoninck, Philip; Devlieger, Roland; Lanna, Mariano M; Deprest, Jan; Favre, Romain; Oepkes, Dick; Lopriore, Enrico

2014-09-01

Residual anastomoses after fetoscopic laser surgery for twin-to-twin transfusion syndrome (TTTS) may lead to severe postoperative complications, including recurrent TTTS and twin anemia-polycythemia sequence (TAPS). A novel technique (Solomon technique) using laser coagulation of the entire vascular equator was recently investigated in a randomized controlled trial (Solomon trial) and compared with the Standard selective laser technique. The aim of this secondary analysis was to evaluate the occurrence and characteristics of residual anastomoses in placentas included in the Solomon trial. International multicenter randomized controlled trial in TTTS, randomized 1:1 ratio to either the Solomon laser technique or Standard laser technique. At time of laser, surgeons recorded whether they considered the procedure to be complete. Placental dye injection was performed after birth in the participating centers to evaluate the presence of residual anastomoses. A total of 151 placentas were included in the study. The percentage of placentas with residual anastomoses in the Solomon group and Standard group was 19% (14/74) and 34% (26/77), respectively (P = .04). The percentage of placentas with residual anastomoses in the subgroup of cases where the procedure was recorded as complete was 8/65 (12%) and 22/69 (32%) in the Solomon group and Standard group, respectively (P < .01). The Solomon laser technique reduces the risk of residual anastomoses. However, careful follow-up remains essential also after the Solomon technique, as complete dichorionization is not always achieved. Copyright © 2014 Mosby, Inc. All rights reserved.

Moving a randomized clinical trial into an observational cohort.

PubMed

Goodman, Phyllis J; Hartline, Jo Ann; Tangen, Catherine M; Crowley, John J; Minasian, Lori M; Klein, Eric A; Cook, Elise D; Darke, Amy K; Arnold, Kathryn B; Anderson, Karen; Yee, Monica; Meyskens, Frank L; Baker, Laurence H

2013-02-01

The Selenium and Vitamin E Cancer Prevention Trial (SELECT) was a randomized, double-blind, placebo-controlled prostate cancer prevention study funded by the National Cancer Institute (NCI) and conducted by the Southwest Oncology Group (SWOG). A total of 35,533 men were assigned randomly to one of the four treatment groups (vitamin E + placebo, selenium + placebo, vitamin E + selenium, and placebo + placebo). The independent Data and Safety Monitoring Committee (DSMC) recommended the discontinuation of study supplements because of the lack of efficacy for risk reduction and because futility analyses demonstrated no possibility of benefit of the supplements to the anticipated degree (25% reduction in prostate cancer incidence) with additional follow-up. Study leadership agreed that the randomized trial should be terminated but believed that the cohort should be maintained and followed as the additional follow-up would contribute important information to the understanding of the biologic consequences of the intervention. Since the participants no longer needed to be seen in person to assess acute toxicities or to be given study supplements, it was determined that the most efficient and cost-effective way to follow them was via a central coordinated effort. A number of changes were necessary at the local Study Sites and SELECT Statistical Center to transition to following participants via a Central Coordinating Center. We describe the transition process from a randomized clinical trial to the observational Centralized Follow-Up (CFU) study. The process of transitioning SELECT, implemented at more than 400 Study Sites across the United States, Canada, and Puerto Rico, entailed many critical decisions and actions including updates to online documents such as the SELECT Workbench and Study Manual, a protocol amendment, reorganization of the Statistical Center, creation of a Transition Committee, development of materials for SELECT Study Sites, development of procedures to close Study Sites, and revision of data collection procedures and the process by which to contact participants. At the time of the publication of the primary SELECT results in December 2008, there were 32,569 men alive and currently active in the trial. As of 31 December 2011, 17,761 participants had been registered to the CFU study. This number is less than had been anticipated due to unforeseen difficulties with local Study Site institutional review boards (IRBs). However, from this cohort, we estimate that an additional 580 prostate cancer cases and 215 Gleason 7 or higher grade cancers will be identified. Over 109,000 individual items have been mailed to participants. Active SELECT ancillary studies have continued. The substantial SELECT biorepository is available to researchers; requests to use the specimens are reviewed for feasibility and scientific merit. As of April 2012, 12 proposals had been approved. The accrual goal of the follow-up study was not met, limiting our power to address the study objectives satisfactorily. The CFU study is also dependent on a number of factors including continued funding, continued interest of investigators in the biorepository, and the continued contribution of the participants. Our experience may be less pertinent to investigators who wish to follow participants in a treatment trial or participants in prevention trials in other medical areas. Extended follow-up of participants in prevention research is important to study the long-term effects of the interventions, such as those used in SELECT. The approach taken by SELECT investigators was to continue to follow participants centrally via an annual questionnaire and with a web-based option. The participants enrolled in the CFU study represent a large, well-characterized, generally healthy cohort. The CFU has enabled us to collect additional prostate and other cancer endpoints and longer follow-up on the almost 18,000 participants enrolled. The utility of the extensive biorepository that was developed during the course of the SELECT is enhanced by longer follow-up.

Moving a Randomized Clinical Trial into an Observational Cohort

PubMed Central

Goodman, Phyllis J.; Hartline, Jo Ann; Tangen, Catherine M.; Crowley, John J.; Minasian, Lori M.; Klein, Eric A.; Cook, Elise D.; Darke, Amy K.; Arnold, Kathryn B.; Anderson, Karen; Yee, Monica; Meyskens, Frank L.; Baker, Laurence H.

2013-01-01

Background The Selenium and Vitamin E Cancer Prevention Trial (SELECT) was a randomized, double blind, placebo-controlled prostate cancer prevention study funded by the National Cancer Institute and conducted by SWOG (Southwest Oncology Group). A total of 35,533 men were assigned randomly to one of four treatment groups (vitamin E + placebo, selenium + placebo, vitamin E + selenium, placebo + placebo. The independent Data and Safety Monitoring Committee recommended the discontinuation of study supplements because of the lack of efficacy for risk reduction and because futility analyses demonstrated no possibility of benefit of the supplements to the anticipated degree (25% reduction in prostate cancer incidence) with additional follow-up. Study leadership agreed that the randomized trial should be terminated but believed that the cohort should be maintained and followed as the additional follow-up would contribute important information to the understanding of the biologic consequences of the intervention. Since the participants no longer needed to be seen in person to assess acute toxicities or to be given study supplements, it was determined that the most efficient and cost-effective way to follow them was via a central coordinated effort. Purpose A number of changes were necessary at the local Study Sites and SELECT Statistical Center to transition to following participants via a Central Coordinating Center. We describe the transition process from a randomized clinical trial to the observational Centralized Follow-up (CFU) study. Methods The process of transitioning SELECT, implemented at more than 400 Study Sites across the United States, Canada and Puerto Rico, entailed many critical decisions and actions including updates to online documents such as the SELECT Workbench and Study Manual, a protocol amendment, reorganization of the Statistical Center, creation of a Transition Committee, development of materials for SELECT Study Sites, development of procedures to close Study Sites, and revision of data collection procedures and the process by which to contact participants. Results At the time of the publication of the primary SELECT results in December 2008, there were 32,569 men alive and currently active in the trial. As of December 31, 2011, 17,761 participants had been registered to the CFU study. This number is less than had been anticipated due to unforeseen difficulties with local Study Site IRBs. However, from this cohort we estimate that an additional 580 prostate cancer cases and 215 Gleason 7 or higher cancers will be identified. Over 109,000 individual items have been mailed to participants. Active SELECT ancillary studies have continued. The substantial SELECT biorepository is available to researchers; requests to use the specimens are reviewed for feasibility and scientific merit. As of April 2012, 12 proposals had been approved. Limitations The accrual goal of the follow-up study was not met, limiting our power to address the study objectives satisfactorily. The CFU study is also dependent on a number of factors including continued funding, continued interest of investigators in the biorepository and the continued contribution of the participants. Our experience may be less pertinent to investigators who wish to follow participants in a treatment trial or participants in prevention trials in other medical areas. Conclusions Extended follow-up of participants in prevention research is important to study the long-term effects of the interventions, such as those used in SELECT. The approach taken by SELECT investigators was to continue to follow participants centrally via an annual questionnaire and with a web-based option. The participants enrolled in the CFU study represent a large, well-characterized, generally healthy cohort. The CFU has enabled us to collect additional prostate and other cancer endpoints and longer follow-up on the almost 18,000 participants enrolled. The utility of the extensive biorepository that was developed during the course of the SELECT is enhanced by longer follow-up. PMID:23064404

Fibroblast Activation Protein-Alpha, a Serine Protease that Facilitates Metastasis by Modification of Diverse Microenvironments

DTIC Science & Technology

2011-10-01

lung tissue. We were not able to detect sufficient numbers of cells in this manner. We tried a different procedure for fixing the lungs after they...added after 24 hours. The films were fixed and evaluated microscopically. In four trials, 10 random microscopic fields were selected and... dosing by oral gavage once daily with 1.3 mg/kg L-valine-L-boroproline called talabostat (extracellular & intracellular DASH), 13.3 mg/kg L- glutamyl

Automated Neuropsychological Assessment Metrics Version 4 (ANAM4): Select Psychometric Properties and Administration Procedures

DTIC Science & Technology

2012-12-01

month no- cost extension for this study was approved on 7 November 2012, extending study activities through December 2013. A modified statement of work...approved as part of the no- cost extension and currently pending approval by the USARIEM HURC (Amendment #14), is presented in Table 2. 5...ptjournal.apta.org/Downloaded from 13     time. SAS 9.2 was used to perform a mixed model analysis with random individual intercept to account for

The Effectiveness of Two Grammar Treatment Procedures for Children with SLI: A Randomized Clinical Trial

ERIC Educational Resources Information Center

Smith-Lock, Karen M.; Leitão, Suze; Prior, Polly; Nickels, Lyndsey

2015-01-01

Purpose: This study compared the effectiveness of two grammar treatment procedures for children with specific language impairment. Method: A double-blind superiority trial with cluster randomization was used to compare a cueing procedure, designed to elicit a correct production following an initial error, to a recasting procedure, which required…

Extending cluster Lot Quality Assurance Sampling designs for surveillance programs

PubMed Central

Hund, Lauren; Pagano, Marcello

2014-01-01

Lot quality assurance sampling (LQAS) has a long history of applications in industrial quality control. LQAS is frequently used for rapid surveillance in global health settings, with areas classified as poor or acceptable performance based on the binary classification of an indicator. Historically, LQAS surveys have relied on simple random samples from the population; however, implementing two-stage cluster designs for surveillance sampling is often more cost-effective than simple random sampling. By applying survey sampling results to the binary classification procedure, we develop a simple and flexible non-parametric procedure to incorporate clustering effects into the LQAS sample design to appropriately inflate the sample size, accommodating finite numbers of clusters in the population when relevant. We use this framework to then discuss principled selection of survey design parameters in longitudinal surveillance programs. We apply this framework to design surveys to detect rises in malnutrition prevalence in nutrition surveillance programs in Kenya and South Sudan, accounting for clustering within villages. By combining historical information with data from previous surveys, we design surveys to detect spikes in the childhood malnutrition rate. PMID:24633656

Comparison of in vivo 3D cone-beam computed tomography tooth volume measurement protocols.

PubMed

Forst, Darren; Nijjar, Simrit; Flores-Mir, Carlos; Carey, Jason; Secanell, Marc; Lagravere, Manuel

2014-12-23

The objective of this study is to analyze a set of previously developed and proposed image segmentation protocols for precision in both intra- and inter-rater reliability for in vivo tooth volume measurements using cone-beam computed tomography (CBCT) images. Six 3D volume segmentation procedures were proposed and tested for intra- and inter-rater reliability to quantify maxillary first molar volumes. Ten randomly selected maxillary first molars were measured in vivo in random order three times with 10 days separation between measurements. Intra- and inter-rater agreement for all segmentation procedures was attained using intra-class correlation coefficient (ICC). The highest precision was for automated thresholding with manual refinements. A tooth volume measurement protocol for CBCT images employing automated segmentation with manual human refinement on a 2D slice-by-slice basis in all three planes of space possessed excellent intra- and inter-rater reliability. Three-dimensional volume measurements of the entire tooth structure are more precise than 3D volume measurements of only the dental roots apical to the cemento-enamel junction (CEJ).

Extending cluster lot quality assurance sampling designs for surveillance programs.

PubMed

Hund, Lauren; Pagano, Marcello

2014-07-20

Lot quality assurance sampling (LQAS) has a long history of applications in industrial quality control. LQAS is frequently used for rapid surveillance in global health settings, with areas classified as poor or acceptable performance on the basis of the binary classification of an indicator. Historically, LQAS surveys have relied on simple random samples from the population; however, implementing two-stage cluster designs for surveillance sampling is often more cost-effective than simple random sampling. By applying survey sampling results to the binary classification procedure, we develop a simple and flexible nonparametric procedure to incorporate clustering effects into the LQAS sample design to appropriately inflate the sample size, accommodating finite numbers of clusters in the population when relevant. We use this framework to then discuss principled selection of survey design parameters in longitudinal surveillance programs. We apply this framework to design surveys to detect rises in malnutrition prevalence in nutrition surveillance programs in Kenya and South Sudan, accounting for clustering within villages. By combining historical information with data from previous surveys, we design surveys to detect spikes in the childhood malnutrition rate. Copyright © 2014 John Wiley & Sons, Ltd.

Random analysis of bearing capacity of square footing using the LAS procedure

NASA Astrophysics Data System (ADS)

Kawa, Marek; Puła, Wojciech; Suska, Michał

2016-09-01

In the present paper, a three-dimensional problem of bearing capacity of square footing on random soil medium is analyzed. The random fields of strength parameters c and φ are generated using LAS procedure (Local Average Subdivision, Fenton and Vanmarcke 1990). The procedure used is re-implemented by the authors in Mathematica environment in order to combine it with commercial program. Since the procedure is still tested the random filed has been assumed as one-dimensional: the strength properties of soil are random in vertical direction only. Individual realizations of bearing capacity boundary-problem with strength parameters of medium defined the above procedure are solved using FLAC3D Software. The analysis is performed for two qualitatively different cases, namely for the purely cohesive and cohesive-frictional soils. For the latter case the friction angle and cohesion have been assumed as independent random variables. For these two cases the random square footing bearing capacity results have been obtained for the range of fluctuation scales from 0.5 m to 10 m. Each time 1000 Monte Carlo realizations have been performed. The obtained results allow not only the mean and variance but also the probability density function to be estimated. An example of application of this function for reliability calculation has been presented in the final part of the paper.

Prevalence and Characterization of Motile Salmonella in Commercial Layer Poultry Farms in Bangladesh

PubMed Central

Barua, Himel; Biswas, Paritosh K.; Olsen, Katharina E. P.; Christensen, Jens P.

2012-01-01

Salmonella is a globally widespread food-borne pathogen having major impact on public health. All motile serovars of Salmonella enterica of poultry origin are zoonotic, and contaminated meat and raw eggs are an important source to human infections. Information on the prevalence of Salmonella at farm/holding level, and the zoonotic serovars circulating in layer poultry in the South and South-East Asian countries including Bangladesh, where small-scale commercial farms are predominant, is limited. To investigate the prevalence of Salmonella at layer farm level, and to identify the prevalent serovars we conducted a cross-sectional survey by randomly selecting 500 commercial layer poultry farms in Bangladesh. Faecal samples from the selected farms were collected following standard procedure, and examined for the presence of Salmonella using conventional bacteriological procedures. Thirty isolates were randomly selected, from the ninety obtained from the survey, for serotyping and characterized further by plasmid profiling and pulsed-field gel electrophoresis (PFGE). Results of the survey showed that the prevalence of motile Salmonella at layer farm level was 18% (95% confidence interval 15–21%), and Salmonella Kentucky was identified to be the only serovar circulating in the study population. Plasmid analysis of the S. Kentucky and non-serotyped isolates revealed two distinct profiles with a variation of two different sizes (2.7 and 4.8 kb). PFGE of the 30 S. Kentucky and 30 non-serotyped isolates showed that all of them were clonally related because only one genotype and three subtypes were determined based on the variation in two or three bands. This is also the first report on the presence of any specific serovar of Salmonella enterica in poultry in Bangladesh. PMID:22558269

Prevalence and characterization of motile Salmonella in commercial layer poultry farms in Bangladesh.

PubMed

Barua, Himel; Biswas, Paritosh K; Olsen, Katharina E P; Christensen, Jens P

2012-01-01

Salmonella is a globally widespread food-borne pathogen having major impact on public health. All motile serovars of Salmonella enterica of poultry origin are zoonotic, and contaminated meat and raw eggs are an important source to human infections. Information on the prevalence of Salmonella at farm/holding level, and the zoonotic serovars circulating in layer poultry in the South and South-East Asian countries including Bangladesh, where small-scale commercial farms are predominant, is limited. To investigate the prevalence of Salmonella at layer farm level, and to identify the prevalent serovars we conducted a cross-sectional survey by randomly selecting 500 commercial layer poultry farms in Bangladesh. Faecal samples from the selected farms were collected following standard procedure, and examined for the presence of Salmonella using conventional bacteriological procedures. Thirty isolates were randomly selected, from the ninety obtained from the survey, for serotyping and characterized further by plasmid profiling and pulsed-field gel electrophoresis (PFGE). Results of the survey showed that the prevalence of motile Salmonella at layer farm level was 18% (95% confidence interval 15-21%), and Salmonella Kentucky was identified to be the only serovar circulating in the study population. Plasmid analysis of the S. Kentucky and non-serotyped isolates revealed two distinct profiles with a variation of two different sizes (2.7 and 4.8 kb). PFGE of the 30 S. Kentucky and 30 non-serotyped isolates showed that all of them were clonally related because only one genotype and three subtypes were determined based on the variation in two or three bands. This is also the first report on the presence of any specific serovar of Salmonella enterica in poultry in Bangladesh.

Impact of nitroglycerin and glucagon administration on selective common bile duct cannulation and prevention of post-ERCP pancreatitis.

PubMed

Katsinelos, Panagiotis; Lazaraki, Georgia; Chatzimavroudis, Grigoris; Katsinelos, Taxiarchis; Georgakis, Nikos; Anastasiadou, Kyriaki; Gatopoulou, Anthi; Zeglinas, Christos; Psarras, Kyriakos; Kountouras, Jannis

2017-01-01

Easy common bile duct (CBD) cannulation is associated with low complication rate. This study aimed to investigate the potential impact of nitroglycerin and glucagon administration on selective CBD cannulation and prevention of post-ERCP pancreatitis. A prospective single center, double-blind randomized study in which a total of 455 patients were randomly assigned to CBD cannulation by receiving 6 puffs (2.4 mg) sublingual nitroglycerin and glucagon 1 mg intravenously (n = 227, group A) or 6 puffs sterile water and 20 mg hyoscine-n-butyl bromide intravenously (n = 228, group B). After ERCP, patients were followed for the development of drugs' side-effects and post-ERCP complications. There were no statistically significant differences between the two groups regarding demographic data and ERCP findings. Success rate of selective CΒD cannulation was 95.15% in group A versus 82.29% in group B (p < .001). Time required for CBD cannulation was 2.82 ± 2.31 min in group A versus 4.27 ± 3.84 min in group B (p = .021). Needle-knife papillotomy was used in 11 (4.85%) patients of group A and 39 (17.11%) patients of group B (p = .001). The frequency of post-ERCP pancreatitis was significantly lower in group A than in group B (3.08% versus 7.46%, p = .037). No difference was observed between the two groups with regard to the occurrence of post-procedure hemorrhage. There was no procedure-related mortality; no adverse event related to the combination regimen was observed. Combined nitroglycerin and glucagon administration achieves a high selective CBC cannulation rates with concomitant reduction of post-ERCP pancreatitis incidence. However, further relative large-scale studies are needed to confirm our findings before definite conclusions can be drawn (Clinical trial registration number: NT: 4321).

Topology in two dimensions. II - The Abell and ACO cluster catalogues

NASA Astrophysics Data System (ADS)

Plionis, Manolis; Valdarnini, Riccardo; Coles, Peter

1992-09-01

We apply a method for quantifying the topology of projected galaxy clustering to the Abell and ACO catalogues of rich clusters. We use numerical simulations to quantify the statistical bias involved in using high peaks to define the large-scale structure, and we use the results obtained to correct our observational determinations for this known selection effect and also for possible errors introduced by boundary effects. We find that the Abell cluster sample is consistent with clusters being identified with high peaks of a Gaussian random field, but that the ACO shows a slight meatball shift away from the Gaussian behavior over and above that expected purely from the high-peak selection. The most conservative explanation of this effect is that it is caused by some artefact of the procedure used to select the clusters in the two samples.

Interventions to Improve Patient Comprehension in Informed Consent for Medical and Surgical Procedures: A Systematic Review

PubMed Central

Schenker, Yael; Fernandez, Alicia; Sudore, Rebecca; Schillinger, Dean

2017-01-01

Background Patient understanding in clinical informed consent is often poor. Little is known about the effectiveness of interventions to improve comprehension or the extent to which such interventions address different elements of understanding in informed consent. Purpose To systematically review communication interventions to improve patient comprehension in informed consent for medical and surgical procedures. Data Sources A systematic literature search of English-language articles in MEDLINE (1949–2008) and EMBASE (1974–2008) was performed. In addition, a published bibliography of empirical research on informed consent and the reference lists of all eligible studies were reviewed. Study Selection Randomized controlled trials and controlled trials with non-random allocation were included if they compared comprehension in informed consent for a medical or surgical procedure. Only studies that used a quantitative, objective measure of understanding were included. All studies addressed informed consent for a needed or recommended procedure in actual patients. Data Extraction Reviewers independently extracted data using a standardized form. All results were compared, and disagreements were resolved by consensus. Data Synthesis Forty-four studies were eligible. Intervention categories included written information, audiovisual/multimedia, extended discussions, and test/feedback techniques. The majority of studies assessed patient understanding of procedural risks; other elements included benefits, alternatives, and general knowledge about the procedure. Only 6 of 44 studies assessed all 4 elements of understanding. Interventions were generally effective in improving patient comprehension, especially regarding risks and general knowledge. Limitations Many studies failed to include adequate description of the study population, and outcome measures varied widely. Conclusions A wide range of communication interventions improve comprehension in clinical informed consent. Decisions to enhance informed consent should consider the importance of different elements of understanding, beyond procedural risks, as well as feasibility and acceptability of the intervention to clinicians and patients. Conceptual clarity regarding the key elements of informed consent knowledge will help to focus improvements and standardize evaluations. PMID:20357225

Conduct of a personal radiofrequency electromagnetic field measurement study: proposed study protocol.

PubMed

Röösli, Martin; Frei, Patrizia; Bolte, John; Neubauer, Georg; Cardis, Elisabeth; Feychting, Maria; Gajsek, Peter; Heinrich, Sabine; Joseph, Wout; Mann, Simon; Martens, Luc; Mohler, Evelyn; Parslow, Roger C; Poulsen, Aslak Harbo; Radon, Katja; Schüz, Joachim; Thuroczy, György; Viel, Jean-François; Vrijheid, Martine

2010-05-20

The development of new wireless communication technologies that emit radio frequency electromagnetic fields (RF-EMF) is ongoing, but little is known about the RF-EMF exposure distribution in the general population. Previous attempts to measure personal exposure to RF-EMF have used different measurement protocols and analysis methods making comparisons between exposure situations across different study populations very difficult. As a result, observed differences in exposure levels between study populations may not reflect real exposure differences but may be in part, or wholly due to methodological differences. The aim of this paper is to develop a study protocol for future personal RF-EMF exposure studies based on experience drawn from previous research. Using the current knowledge base, we propose procedures for the measurement of personal exposure to RF-EMF, data collection, data management and analysis, and methods for the selection and instruction of study participants. We have identified two basic types of personal RF-EMF measurement studies: population surveys and microenvironmental measurements. In the case of a population survey, the unit of observation is the individual and a randomly selected representative sample of the population is needed to obtain reliable results. For microenvironmental measurements, study participants are selected in order to represent typical behaviours in different microenvironments. These two study types require different methods and procedures. Applying our proposed common core procedures in future personal measurement studies will allow direct comparisons of personal RF-EMF exposures in different populations and study areas.

Conduct of a personal radiofrequency electromagnetic field measurement study: proposed study protocol

PubMed Central

2010-01-01

Background The development of new wireless communication technologies that emit radio frequency electromagnetic fields (RF-EMF) is ongoing, but little is known about the RF-EMF exposure distribution in the general population. Previous attempts to measure personal exposure to RF-EMF have used different measurement protocols and analysis methods making comparisons between exposure situations across different study populations very difficult. As a result, observed differences in exposure levels between study populations may not reflect real exposure differences but may be in part, or wholly due to methodological differences. Methods The aim of this paper is to develop a study protocol for future personal RF-EMF exposure studies based on experience drawn from previous research. Using the current knowledge base, we propose procedures for the measurement of personal exposure to RF-EMF, data collection, data management and analysis, and methods for the selection and instruction of study participants. Results We have identified two basic types of personal RF-EMF measurement studies: population surveys and microenvironmental measurements. In the case of a population survey, the unit of observation is the individual and a randomly selected representative sample of the population is needed to obtain reliable results. For microenvironmental measurements, study participants are selected in order to represent typical behaviours in different microenvironments. These two study types require different methods and procedures. Conclusion Applying our proposed common core procedures in future personal measurement studies will allow direct comparisons of personal RF-EMF exposures in different populations and study areas. PMID:20487532

Lessons learned from a single institution's retrospective analysis of emergent cesarean delivery following external cephalic version with and without neuraxial anesthesia.

PubMed

Ainsworth, A; Sviggum, H P; Tolcher, M C; Weaver, A L; Holman, M A; Arendt, K W

2017-05-01

To evaluate the risk of emergent cesarean delivery with the use of neuraxial anesthesia for external cephalic version in a single practice. Randomized trials have shown increased external cephalic version success when neuraxial anesthesia is used, without additional risk. We hypothesized that in our actual clinical practice, outside the confines of randomized trials, neuraxial anesthesia could be associated with an increased risk of emergent cesarean delivery. This retrospective cohort study included all women who underwent external cephalic version at a single institution with and without neuraxial anesthesia. The primary outcome was the incidence of emergent cesarean delivery (defined as delivery within 4hours of version). Secondary outcomes were version success and ultimate mode of delivery. A total of 135 women underwent external cephalic version procedures; 58 with neuraxial anesthesia (43.0%) and 77 without (57.0%). Location of the procedure, tocolytic therapy, and gestational age were different between groups. An increased rate of emergent cesarean delivery was found in procedures with neuraxial anesthesia compared to procedures without (5/58 (8.6%) compared to 0/77 (0.0%); 95% CI for difference, 1.4 to 15.8%; P=0.013). In this single hospital's practice, patients who may be at higher risk of complications and have a lesser likelihood of success were provided NA for ECV. As a result, the use of neuraxial anesthesia for external cephalic version was associated with a higher rate of emergent cesarean delivery. Obstetric and anesthetic practices should evaluate their patient selection and procedure protocol for external cephalic version under neuraxial anesthesia. Copyright © 2017 Elsevier Ltd. All rights reserved.

Laparoscopic surgery: A qualified systematic review

PubMed Central

Buia, Alexander; Stockhausen, Florian; Hanisch, Ernst

2015-01-01

AIM: To review current applications of the laparoscopic surgery while highlighting the standard procedures across different fields. METHODS: A comprehensive search was undertaken using the PubMed Advanced Search Builder. A total of 321 articles were found in this search. The following criteria had to be met for the publication to be selected: Review article, randomized controlled trials, or meta-analyses discussing the subject of laparoscopic surgery. In addition, publications were hand-searched in the Cochrane database and the high-impact journals. A total of 82 of the findings were included according to matching the inclusion criteria. Overall, 403 full-text articles were reviewed. Of these, 218 were excluded due to not matching the inclusion criteria. RESULTS: A total of 185 relevant articles were identified matching the search criteria for an overview of the current literature on the laparoscopic surgery. Articles covered the period from the first laparoscopic application through its tremendous advancement over the last several years. Overall, the biggest advantage of the procedure has been minimizing trauma to the abdominal wall compared with open surgery. In the case of cholecystectomy, fundoplication, and adrenalectomy, the procedure has become the gold standard without being proven as a superior technique over the open surgery in randomized controlled trials. Faster recovery, reduced hospital stay, and a quicker return to normal activities are the most evident advantages of the laparoscopic surgery. Positive outcomes, efficiency, a lower rate of wound infections, and reduction in the perioperative morbidity of minimally invasive procedures have been shown in most indications. CONCLUSION: Improvements in surgical training and developments in instruments, imaging, and surgical techniques have greatly increased safety and feasibility of the laparoscopic surgical procedures. PMID:26713285

Strong adsorption of random heteropolymers on protein surfaces

NASA Astrophysics Data System (ADS)

Nguyen, Trung; Qiao, Baofu; Panganiban, Brian; Delre, Christopher; Xu, Ting; Olvera de La Cruz, Monica

Rational design of copolymers for stablizing proteins' functionalities in unfavorable solvents and delivering nanoparticles through organic membranes demands a thorough understanding of how the proteins and colloids are encapsulated by a given type of copolymers. Random heteropolymers (RHPs), a special family of copolymers with random segment order, have long been recognized as a promising coating materials due to their biomimetic behaviors while allowing for much flexibility in the synthesis procedure. Of practical importance is the ability to predict the conditions under which a given family of random heteropolymers would provide optimal encapsulatio. Here we investigate the key factors that govern the adsorption of RHPs on the surface of a model protein. Using coarse-grained molecular simulation we identify the conditions under which the model protein is fully covered by the polymers. We have examined the nanometer-level details of the adsorbed polymer chains and found a clear connection between the surface coverage and adsorption strength, solvent selectivity and the volume fraction of adsorbing monomers. The results in this work set the stage for further investigation on engineering biomimetic RHPs for stabilizing and delivering functional proteins across multiple media.

CW-SSIM kernel based random forest for image classification

NASA Astrophysics Data System (ADS)

Fan, Guangzhe; Wang, Zhou; Wang, Jiheng

2010-07-01

Complex wavelet structural similarity (CW-SSIM) index has been proposed as a powerful image similarity metric that is robust to translation, scaling and rotation of images, but how to employ it in image classification applications has not been deeply investigated. In this paper, we incorporate CW-SSIM as a kernel function into a random forest learning algorithm. This leads to a novel image classification approach that does not require a feature extraction or dimension reduction stage at the front end. We use hand-written digit recognition as an example to demonstrate our algorithm. We compare the performance of the proposed approach with random forest learning based on other kernels, including the widely adopted Gaussian and the inner product kernels. Empirical evidences show that the proposed method is superior in its classification power. We also compared our proposed approach with the direct random forest method without kernel and the popular kernel-learning method support vector machine. Our test results based on both simulated and realworld data suggest that the proposed approach works superior to traditional methods without the feature selection procedure.

A survey on the effectiveness of using GeoGebra software towards lecturers' conceptual knowledge and procedural mathematics

NASA Astrophysics Data System (ADS)

Wan Salleh, Masturah; Sulaiman, Hajar

2013-04-01

The use of technology in the teaching of mathematics at the university level has long been introduced; but many among the lecturers, especially those that have taught for many years, still opt for a traditional teaching method, that is, by lecture talk. One reason is that lecturers themselves were not exposed to the technologies available and how it can assist in the teaching and learning procedures (T&L) in mathematics. GeoGebra is a mathematical software which is open and free and has just recently been introduced in Malaysia. Compared with the software Cabri Geometry and Geometer's Sketchpad (GSP), which only focus on geometry, GeoGebra is able to connect geometry, algebra and numerical representation. Realizing this, the researchers have conducted a study to expose the university lecturers on the use of GeoGebra in T&L. The researchers chose to do the research on mathematics lecturers at the Department of Computer Science and Mathematics (JSKM), Universiti Teknologi Mara (UiTM), Penang. The objective of this study is to determine whether an exposure to GeoGebra software can affect the conceptual knowledge and procedural teaching of mathematics at the university level. This study is a combination of descriptive and qualitative. One session was conducted in an open workshop for all the 45 lecturers. From that total, four people were selected as a sample. The sample was selected by using a simple random sampling method. This study used materials in the form of modules during the workshop. In terms of conceptual knowledge, the results showed that the GeoGebra software is appropriate, relevant and highly effective for in-depth understanding of the selected topics. While the procedural aspects of teaching, it can be one of the teaching aids and considerably facilitate the lecturers.

Carotid Endarterectomy: Current Concepts and Practice Patterns

PubMed Central

Saha, Sibu P.; Saha, Subhajit; Vyas, Krishna S.

2015-01-01

Background Stroke is the number one cause of disability and third leading cause of death among adults in the United States. A major cause of stroke is carotid artery stenosis (CAS) caused by atherosclerotic plaques. Randomized trials have varying results regarding the equivalence and perioperative complication rates of stents versus carotid endarterectomy (CEA) in the management of CAS. Objectives We review the evidence for the current management of CAS and describe the current concepts and practice patterns of CEA. Methods A literature search was conducted using PubMed to identify relevant studies regarding CEA and stenting for the management of CAS. Results The introduction of CAS has led to a decrease in the percentage of CEA and an increase in the number of CAS procedures performed in the context of all revascularization procedures. However, the efficacy of stents in patients with symptomatic CAS remains unclear because of varying results among randomized trials, but the perioperative complication rates exceed those found after CEA. Conclusions Vascular surgeons are uniquely positioned to treat carotid artery disease through medical therapy, CEA, and stenting. Although data from randomized trials differ, it is important for surgeons to make clinical decisions based on the patient. We believe that CAS can be adopted with low complication rate in a selected subgroup of patients, but CEA should remain the standard of care. This current evidence should be incorporated into practice of the modern vascular surgeon. PMID:26417192

Online doctor reviews: do they track surgeon volume, a proxy for quality of care?

PubMed

Segal, Jeffrey; Sacopulos, Michael; Sheets, Virgil; Thurston, Irish; Brooks, Kendra; Puccia, Ryan

2012-04-10

Increasingly, consumers are accessing the Internet seeking health information. Consumers are also using online doctor review websites to help select their physician. Such websites tally numerical ratings and comments from past patients. To our knowledge, no study has previously analyzed whether doctors with positive online reputations on doctor review websites actually deliver higher quality of care typically associated with better clinical outcomes and better safety records. For a number of procedures, surgeons who perform more procedures have better clinical outcomes and safety records than those who perform fewer procedures. Our objective was to determine if surgeon volume, as a proxy for clinical outcomes and patient safety, correlates with online reputation. We investigated the numerical ratings and comments on 9 online review websites for high- and low-volume surgeons for three procedures: lumbar surgery, total knee replacement, and bariatric surgery. High-volume surgeons were randomly selected from the group within the highest quartile of claims submitted for reimbursement using the procedures' relevant current procedural terminology (CPT) codes. Low-volume surgeons were randomly selected from the lowest quartile of submitted claims for the procedures' relevant CPT codes. Claims were collated within the Normative Health Information Database, covering multiple payers for more than 25 million insured patients. Numerical ratings were found for the majority of physicians in our sample (547/600, 91.2%) and comments were found for 385/600 (64.2%) of the physicians. We found that high-volume (HV) surgeons could be differentiated from low-volume (LV) surgeons independently by analyzing: (1) the total number of numerical ratings per website (HV: mean = 5.85; LV: mean = 4.87, P<.001); (2) the total number of text comments per website (HV: mean = 2.74; LV: mean = 2.30, P=.05); (3) the proportion of glowing praise/total comments about quality of care (HV: mean = 0.64; LV: mean = 0.51, P=.002); and (4) the proportion of scathing criticism/total comments about quality of care (HV: mean = 0.14; LV: mean = 0.23, P= .005). Even when these features were combined, the effect size, although significant, was still weak. The results revealed that one could accurately identify a physician's patient volume via discriminant and classification analysis 61.6% of the time. We also found that high-volume surgeons could not be differentiated from low-volume surgeons by analyzing (1) standardized z score numerical ratings (HV: mean = 0.07; LV: mean = 0, P=.27); (2) proportion of glowing praise/total comments about customer service (HV: mean = 0.24; LV: mean = 0.22, P=.52); and (3) proportion of scathing criticism/total comments about customer service (HV: mean = 0.19; LV: mean = 0.21, P=.48). Online review websites provide a rich source of data that may be able to track quality of care, although the effect size is weak and not consistent for all review website metrics.

24 CFR 983.51 - Owner proposal selection procedures.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Owner proposal selection procedures... proposal selection procedures. (a) Procedures for selecting PBV proposals. The PHA administrative plan must describe the procedures for owner submission of PBV proposals and for PHA selection of PBV proposals...

Mortality after percutaneous edge-to-edge mitral valve repair: a contemporary review.

PubMed

Kortlandt, Friso A; de Beenhouwer, Thomas; Swaans, Martin J; Post, Marco C; van der Heyden, Jan A S; Eefting, Frank D; Rensing, Benno J W M

2016-04-01

Percutaneous edge-to-edge mitral valve (MV) repair is a relatively new treatment option for mitral regurgitation (MR). After the feasibility and safety having been proved in low-surgical-risk patients, the use of this procedure has shifted more to the treatment of high-risk patients. With the absence of randomized controlled trials (RCT) for this particular subgroup, observational studies try to add evidence to the safety aspect of this procedure. These also provide short- and mid-term mortality figures. Several mortality predictors have been identified, which may help the optimal selection of patients who will benefit most from this technique. In this article we provide an overview of the literature about mortality and its predictors in patients treated with the percutaneous edge-to-edge device.

A comparative study of modified transcanalicular diode laser dacryocystorhinostomy versus conventional transcanalicular diode laser dacryocystorhinostomy.

PubMed

Feijó, Eduardo Damous; Caixeta, Juliana Alves; de Souza Nery, Ana Carla; Limongi, Roberto Murillo; Matayoshi, Suzana

2017-08-01

External dacryocystorhinostomy (DCR) is the gold standard surgical technique for the treatment of primary acquired nasolacrimal duct obstruction (PANDO). However, new techniques such as endoscopic DCR and transcanalicular dacryocystorhinostomy (T-DCR) are being studied in an attempt to reduce surgical time, avoid external scarring and preserve the lacrimal pump while achieving the same efficacy. The purpose of this study was to compare the efficacy between conventional T-DCR and modified transcanalicular dacryocystorhinostomy (MT-DCR) in patients with PANDO. MT-DCR is performed to remove nasal mucosa prior to laser osteotomy. This is a comparative, prospective, interventionist and randomized study. Patients with PANDO were selected to undergo MT-DCR or T-DCR by blocked randomization. PANDO was diagnosed based on clinical presentation, dye disappearance test and dacryocystography. All of the procedures were performed by the same surgery team members. Anatomical success outcome was defined as positive lacrimal syringing and functional success outcome was defined as the absence or improvement of epiphora. A total of 44 surgical procedures were performed (22 MT-DCR and 22 T-DCR). In the case of MT-DCR, the anatomical and functional success rates after 12 months were 90 and 86%, respectively. After T-DCR, these rates were 77 and 72%, respectively (p = 0.162). MT-DCR and T-DCR are both safe and fast procedures with low morbidity and well-tolerated.

[Acupuncture in fibromyalgia: a randomized, controlled study addressing the immediate pain response].

PubMed

Stival, Rebecca Saray Marchesini; Cavalheiro, Patrícia Rechetello; Stasiak, Camila Edith Stachera; Galdino, Dayana Talita; Hoekstra, Bianca Eliza; Schafranski, Marcelo Derbli

2014-01-01

To evaluate the efficacy of acupuncture in the treatment of fibromyalgia, considering the immediate response of the visual analogue pain scale (VAS) as its primary outcome. Randomized, controlled, double-blind study including 36 patients with fibromyalgia (ACR 1990) selected from the outpatient rheumatology clinic, Santa Casa de Misericórdia, Ponta Grossa, PR. Twenty-one patients underwent an acupuncture session, under the principles of the traditional Chinese medicine, and 15 patients underwent a placebo procedure (sham acupuncture). For pain assessment, the subjects completed a Visual Analogue Scale (VAS) before and immediately after the proposed procedure. The mean change in VAS was compared among groups. The variation between the final and initial VAS values was -4.36±3.23 (P=0.0001) in the treatment group and -1.70±1.55 in the control group (P=0.06). The difference in terms of amplitude of variation of VAS (initial - final VAS) among groups favored the actual procedure (P=0.005). The effect size (ES) for the treatment group was d=1.7, which is considered a large effect. Although small, the statistical power of the sample for these results was very relevant (94.8%). Acupuncture has proven effective in the immediate pain reduction in patients with fibromyalgia, with a quite significant effect size. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

Changes in pitching mechanics after ulnar collateral ligament reconstruction in major league baseball pitchers.

PubMed

Portney, Daniel A; Lazaroff, Jake M; Buchler, Lucas T; Gryzlo, Stephen M; Saltzman, Matthew D

2017-08-01

Medial ulnar collateral ligament (UCL) reconstruction is a common procedure performed on Major League Baseball pitchers. Variations in pitching mechanics before and after UCL reconstructive surgery are not well understood. Publicly available pitch tracking data (PITCHf/x) were compared for all Major League Baseball pitchers who underwent UCL reconstruction between 2008 and 2013. Specific parameters analyzed were fastball percentage, release location, velocity, and movement of each pitch type. These data were compared before and after UCL reconstructive surgery and compared with a randomly selected control cohort. There were no statistically significant changes in pitch selection or pitch accuracy after UCL reconstruction, nor was there a decrease in pitch velocity. The average pitch release location for 4-seam and 2-seam fastballs, curveballs, and changeups is more medial after UCL reconstruction (P < .01). Four-seam fastballs and sliders showed decreased horizontal breaking movement after surgery (P < .05), whereas curveballs showed increased downward breaking movement after surgery (P < .05). Pitch selection, pitch velocity, and pitch accuracy do not significantly change after UCL reconstruction, nor do players who require UCL reconstruction have significantly different pitch selection, velocity, or accuracy than a randomly selected control cohort. Pitch release location is more medial after UCL reconstruction for all pitch types except sliders. Breaking movement of fastballs, sliders, and curveballs changes after UCL reconstruction. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Patient-centered outcomes comparing digital and conventional implant impression procedures: a randomized crossover trial.

PubMed

Joda, Tim; Brägger, Urs

2016-12-01

The aim of this randomized controlled trial was to compare patient-centered outcomes during digital and conventional implant impressions. In a crossover study design, intraoral scanning (IOS) [test] as well as classical polyether impressions [control] were both performed on 20 patients for single-tooth replacement with implant-supported crowns. The sequential distribution of either starting with the test or the control procedure was randomly selected. Patients' perception and satisfaction on the level of convenience-related factors were assessed with visual analogue scale (VAS) questionnaires. In addition, clinical work time was separately recorded for test and control procedures. Statistical analyses were performed with Wilcoxon signed-rank tests and corrected for multiple testing by the method of Holm. On VAS ranging from 0 to 100, patients scored a mean convenience level of 78.6 (SD ± 14.0) in favor of IOS compared to conventional impressions with 53.6 (SD ± 15.4) [P = 0.0001]. All included patients would prefer the digital workflow if in the future they could choose between the two techniques. Secondary, IOS was significantly faster with 14.8 min (SD ± 2.2) compared to the conventional approach with 17.9 min (SD ± 1.1) [P = 0.0001]. Based on the findings of this investigation, both impression protocols worked successfully for all study participants capturing the 3D implant positions. However, the digital technique emerges as the most preferred one according to patient-centered outcomes and was more time-effective compared to conventional impressions. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The Childhood Adenotonsillectomy Trial (CHAT): Rationale, Design, and Challenges of a Randomized Controlled Trial Evaluating a Standard Surgical Procedure in a Pediatric Population

PubMed Central

Redline, Susan; Amin, Raouf; Beebe, Dean; Chervin, Ronald D.; Garetz, Susan L.; Giordani, Bruno; Marcus, Carole L.; Moore, Renee H.; Rosen, Carol L.; Arens, Raanan; Gozal, David; Katz, Eliot S.; Mitchell, Ronald B.; Muzumdar, Hiren; Taylor, H.G.; Thomas, Nina; Ellenberg, Susan

2011-01-01

Each year, over 500,000 adenotonsillectomies (AT), mostly for the treatment of pediatric obstructive sleep apnea (OSA) are performed in the US in children under 15 years of age. No definitive study, however, has been yet conducted that has rigorously evaluated the effectiveness of AT for not only improving sleep disordered breathing, but also for improving clinically relevant outcomes, such as neurocognitive function, behavior, and quality of life. The Childhood Adenotonsillectomy Trial (CHAT) was designed to assess neuropsychological and health outcomes in children randomized to receive early AT (eAT) as compared to Watchful Waiting with Supportive Care (WWSC). Important secondary goals of the study are to evaluate outcomes in subgroups defined by obesity and race. This paper addresses key elements in the design and implementation of a controlled trial for a widely used “standard practice” surgical intervention in a pediatric population, that include establishment of standardized data collection procedures across sites for a wide variety of data types, establishment of equipoise, and approaches for minimizing unblinding of selected key personnel. The study framework that was established should provide a useful template for other pediatric controlled studies or other studies that evaluate surgical interventions. Citation: Redline S; Amin R; Beebe D; Chervin RD; Garetz SL; Giordani B; Marcus CL; Moore RH; Rosen CL; Arens R; Gozal D; Katz ES; Mitchell RB; Muzumdar H; Taylor HG; Thomas N; Ellenberg S. The Childhood Adenotonsillectomy Trial (CHAT): rationale, design, and challenges of a randomized controlled trial evaluating a standard surgical procedure in a pediatric population. SLEEP 2011;34(11):1509-1517. PMID:22043122

Cervical Radiculopathy: Effectiveness of Adding Traction to Physical Therapy-A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

PubMed

Romeo, Antonio; Vanti, Carla; Boldrini, Valerio; Ruggeri, Martina; Guccione, Andrew A; Pillastrini, Paolo; Bertozzii, Lucia

2018-04-01

Cervical radiculopathy (CR) is a common cervical spine disorder. Cervical traction (CT) is a frequently recommended treatment for patients with CR. The purpose of this study was to conduct a review and meta-analysis of randomized controlled trials (RCTs) on the effect of CT combined with other physical therapy procedures versus physical therapy procedures alone on pain and disability. Data were obtained from COCHRANE Controlled Trials Register, PubMed, CINAHL, Scopus, ISI Web of Science, and PEDro, from their inception to July 2016. All RCTs on symptomatic adults with CR, without any restriction regarding publication time or language, were considered. Two reviewers selected the studies, conducted the quality assessment, and extracted the results. Meta-analysis employed a random-effects model. The evidence was assessed using GRADE criteria. Five studies met the inclusion criteria. Mechanical traction had a significant effect on pain at short- and intermediate-terms (g = -0.85 [95% CI = -1.63 to -0.06] and g = -1.17 [95% CI = -2.25 to -0.10], respectively) and significant effects on disability at intermediate term (g = -1.05; 95% CI = -1.81 to -0.28). Manual traction had significant effects on pain at short- term (g = -0.85; 95% CI = -1.39 to -0.30). The most important limitation of the present work is the lack of homogeneity in CR diagnostic criteria among the included studies. In light of these results, the current literature lends some support to the use of the mechanical and manual traction for CR in addition to other physical therapy procedures for pain reduction, but yielding lesser effects on function/disability.

Comparative Effect of Contrast Media Type on the Incidence of Contrast-Induced Nephropathy: A Systematic Review and Meta-analysis.

PubMed

Eng, John; Wilson, Renee F; Subramaniam, Rathan M; Zhang, Allen; Suarez-Cuervo, Catalina; Turban, Sharon; Choi, Michael J; Sherrod, Cheryl; Hutfless, Susan; Iyoha, Emmanuel E; Bass, Eric B

2016-03-15

Iodine contrast media are essential components of many imaging procedures. An important potential side effect is contrast-induced nephropathy (CIN). To compare CIN risk for contrast media within and between osmolality classes in patients receiving diagnostic or therapeutic imaging procedures. PubMed, EMBASE, Cochrane Library, Clinical Trials.gov, and Scopus through June 2015. Randomized, controlled trials that reported CIN-related outcomes in patients receiving low-osmolar contrast media (LOCM) or iso-osmolar contrast media for imaging. Independent study selection and quality assessment by 2 reviewers and dual extraction of study characteristics and results. None of the 5 studies that compared types of LOCM reported a statistically significant or clinically important difference among study groups, but the strength of evidence was low. Twenty-five randomized, controlled trials found a slight reduction in CIN risk with the iso-osmolar contrast media agent iodixanol compared with a diverse group of LOCM that just reached statistical significance in a meta-analysis (pooled relative risk, 0.80 [95% CI, 0.65 to 0.99]; P = 0.045). This comparison's strength of evidence was moderate. In a meta regression of randomized, controlled trials of iodixanol, no relationship was found between route of administration and comparative CIN risk. Few studies compared LOCM. Procedural details about contrast administration were not uniformly reported. Few studies specified clinical indications or severity of baseline renal impairment. No differences were found in CIN risk among types of LOCM. Iodixanol had a slightly lower risk for CIN than LOCM, but the lower risk did not exceed a criterion for clinical importance. Agency for Healthcare Research and Quality.

Teaching procedural skills to medical students: A pilot procedural skills lab.

PubMed

Katz, Laurence M; Finch, Alexander; McKinnish, Tyler; Gilliland, Kurt; Tolleson-Rinehart, Sue; Marks, Bonita L

2017-01-01

Medical students have limited confidence in performing procedural skills. A pilot study was conducted to evaluate the effect of a multifaceted Procedural Skills Lab (PSL) on the confidence of medical students to perform procedural skills. Twelve 2nd year medical students were randomly selected to participate in a pilot PSL. The PSL students met with an instructor for 2 h once a week for 4 weeks. Students participated in a flipped classroom and spaced education program before laboratory sessions that included a cadaver laboratory. Procedural skills included a focused assessment with sonography in trauma (FAST) scan, cardiac echocardiogram, lumbar puncture, arthrocentesis, and insertion of intraosseous and intravenous catheters. Students in the PSL were asked to rank their confidence in performing procedural skills before and after completion of the laboratory sessions (Wilcoxon ranked-sum test). A web-based questionnaire was also emailed to all 2nd year medical students to establish a baseline frequency for observing, performing, and confidence performing procedural skills (Mann-Whitney U-test). Fifty-nine percent (n = 106) of 180 2nd year medical students (n = 12 PSL students [treatment group], n = 94 [control group]) completed the survey. Frequency of observation, performance, and confidence in performing procedural skills was similar between the control and treatment groups at baseline. There was an increased confidence level (p < 0.001) for performing all procedural skills for the treatment group after completion of the PSL. An innovative PSL may increase students' confidence to perform procedural skills. Future studies will examine competency after a PSL.

Assessment of the geoavailability of trace elements from minerals in mine wastes: analytical techniques and assessment of selected copper minerals

USGS Publications Warehouse

Driscoll, Rhonda; Hageman, Phillip L.; Benzel, William M.; Diehl, Sharon F.; Adams, David T.; Morman, Suzette; Choate, LaDonna M.

2012-01-01

In this study, four randomly selected copper-bearing minerals were examined—azurite, malachite, bornite, and chalcopyrite. The objectives were to examine and enumerate the crystalline and chemical properties of each of the minerals, to determine which, if any, of the Cu-bearing minerals might adversely affect systems biota, and to provide a multi-procedure reference. Laboratory work included use of computational software for quantifying crystalline and amorphous material and optical and electron imaging instruments to model and project crystalline structures. Chemical weathering, human fluid, and enzyme simulation studies were also conducted. The analyses were conducted systematically: X-ray diffraction and microanalytical studies followed by a series of chemical, bio-leaching, and toxicity experiments.

Marginal and Random Intercepts Models for Longitudinal Binary Data With Examples From Criminology.

PubMed

Long, Jeffrey D; Loeber, Rolf; Farrington, David P

2009-01-01

Two models for the analysis of longitudinal binary data are discussed: the marginal model and the random intercepts model. In contrast to the linear mixed model (LMM), the two models for binary data are not subsumed under a single hierarchical model. The marginal model provides group-level information whereas the random intercepts model provides individual-level information including information about heterogeneity of growth. It is shown how a type of numerical averaging can be used with the random intercepts model to obtain group-level information, thus approximating individual and marginal aspects of the LMM. The types of inferences associated with each model are illustrated with longitudinal criminal offending data based on N = 506 males followed over a 22-year period. Violent offending indexed by official records and self-report were analyzed, with the marginal model estimated using generalized estimating equations and the random intercepts model estimated using maximum likelihood. The results show that the numerical averaging based on the random intercepts can produce prediction curves almost identical to those obtained directly from the marginal model parameter estimates. The results provide a basis for contrasting the models and the estimation procedures and key features are discussed to aid in selecting a method for empirical analysis.

Biased random key genetic algorithm with insertion and gender selection for capacitated vehicle routing problem with time windows

NASA Astrophysics Data System (ADS)

Rochman, Auliya Noor; Prasetyo, Hari; Nugroho, Munajat Tri

2017-06-01

Vehicle Routing Problem (VRP) often occurs when the manufacturers need to distribute their product to some customers/outlets. The distribution process is typically restricted by the capacity of the vehicle and the working hours at the distributor. This type of VRP is also known as Capacitated Vehicle Routing Problem with Time Windows (CVRPTW). A Biased Random Key Genetic Algorithm (BRKGA) was designed and coded in MATLAB to solve the CVRPTW case of soft drink distribution. The standard BRKGA was then modified by applying chromosome insertion into the initial population and defining chromosome gender for parent undergoing crossover operation. The performance of the established algorithms was then compared to a heuristic procedure for solving a soft drink distribution. Some findings are revealed (1) the total distribution cost of BRKGA with insertion (BRKGA-I) results in a cost saving of 39% compared to the total cost of heuristic method, (2) BRKGA with the gender selection (BRKGA-GS) could further improve the performance of the heuristic method. However, the BRKGA-GS tends to yield worse results compared to that obtained from the standard BRKGA.

Application of Multiple Imputation for Missing Values in Three-Way Three-Mode Multi-Environment Trial Data

PubMed Central

Tian, Ting; McLachlan, Geoffrey J.; Dieters, Mark J.; Basford, Kaye E.

2015-01-01

It is a common occurrence in plant breeding programs to observe missing values in three-way three-mode multi-environment trial (MET) data. We proposed modifications of models for estimating missing observations for these data arrays, and developed a novel approach in terms of hierarchical clustering. Multiple imputation (MI) was used in four ways, multiple agglomerative hierarchical clustering, normal distribution model, normal regression model, and predictive mean match. The later three models used both Bayesian analysis and non-Bayesian analysis, while the first approach used a clustering procedure with randomly selected attributes and assigned real values from the nearest neighbour to the one with missing observations. Different proportions of data entries in six complete datasets were randomly selected to be missing and the MI methods were compared based on the efficiency and accuracy of estimating those values. The results indicated that the models using Bayesian analysis had slightly higher accuracy of estimation performance than those using non-Bayesian analysis but they were more time-consuming. However, the novel approach of multiple agglomerative hierarchical clustering demonstrated the overall best performances. PMID:26689369

Do nonexercisers also share the positive exerciser stereotype?: An elicitation and comparison of beliefs about exercisers.

PubMed

Rodgers, Wendy M; Hall, Craig R; Wilson, Philip M; Berry, Tanya R

2009-02-01

The purpose of this research was to examine whether exercisers and nonexercisers are rated similarly on a variety of characteristics by a sample of randomly selected regular exercisers, nonexercisers who intend to exercise, and nonexercisers with no intention to exercise. Previous research by Martin Ginis et al. (2003) has demonstrated an exerciser stereotype that advantages exercisers. It is unknown, however, the extent to which an exerciser stereotype is shared by nonexercisers, particularly nonintenders. Following an item-generation procedure, a sample of 470 (n=218 men; n=252 women) people selected using random digit dialing responded to a questionnaire assessing the extent to which they agreed that exercisers and nonexercisers possessed 24 characteristics, such as "happy," "fit," "fat," and "lazy." The results strongly support a positive exerciser bias, with exercisers rated more favorably on 22 of the 24 items. The degree of bias was equivalent in all groups of respondents. Examination of the demographic characteristics revealed no differences among the three groups on age, work status, or child-care responsibilities, suggesting that there is a pervasive positive exerciser bias.

Application of Multiple Imputation for Missing Values in Three-Way Three-Mode Multi-Environment Trial Data.

PubMed

Tian, Ting; McLachlan, Geoffrey J; Dieters, Mark J; Basford, Kaye E

2015-01-01

It is a common occurrence in plant breeding programs to observe missing values in three-way three-mode multi-environment trial (MET) data. We proposed modifications of models for estimating missing observations for these data arrays, and developed a novel approach in terms of hierarchical clustering. Multiple imputation (MI) was used in four ways, multiple agglomerative hierarchical clustering, normal distribution model, normal regression model, and predictive mean match. The later three models used both Bayesian analysis and non-Bayesian analysis, while the first approach used a clustering procedure with randomly selected attributes and assigned real values from the nearest neighbour to the one with missing observations. Different proportions of data entries in six complete datasets were randomly selected to be missing and the MI methods were compared based on the efficiency and accuracy of estimating those values. The results indicated that the models using Bayesian analysis had slightly higher accuracy of estimation performance than those using non-Bayesian analysis but they were more time-consuming. However, the novel approach of multiple agglomerative hierarchical clustering demonstrated the overall best performances.

Algorithms for selecting informative marker panels for population assignment.

PubMed

Rosenberg, Noah A

2005-11-01

Given a set of potential source populations, genotypes of an individual of unknown origin at a collection of markers can be used to predict the correct source population of the individual. For improved efficiency, informative markers can be chosen from a larger set of markers to maximize the accuracy of this prediction. However, selecting the loci that are individually most informative does not necessarily produce the optimal panel. Here, using genotypes from eight species--carp, cat, chicken, dog, fly, grayling, human, and maize--this univariate accumulation procedure is compared to new multivariate "greedy" and "maximin" algorithms for choosing marker panels. The procedures generally suggest similar panels, although the greedy method often recommends inclusion of loci that are not chosen by the other algorithms. In seven of the eight species, when applied to five or more markers, all methods achieve at least 94% assignment accuracy on simulated individuals, with one species--dog--producing this level of accuracy with only three markers, and the eighth species--human--requiring approximately 13-16 markers. The new algorithms produce substantial improvements over use of randomly selected markers; where differences among the methods are noticeable, the greedy algorithm leads to slightly higher probabilities of correct assignment. Although none of the approaches necessarily chooses the panel with optimal performance, the algorithms all likely select panels with performance near enough to the maximum that they all are suitable for practical use.

Evaluation of variable selection methods for random forests and omics data sets.

PubMed

Degenhardt, Frauke; Seifert, Stephan; Szymczak, Silke

2017-10-16

Machine learning methods and in particular random forests are promising approaches for prediction based on high dimensional omics data sets. They provide variable importance measures to rank predictors according to their predictive power. If building a prediction model is the main goal of a study, often a minimal set of variables with good prediction performance is selected. However, if the objective is the identification of involved variables to find active networks and pathways, approaches that aim to select all relevant variables should be preferred. We evaluated several variable selection procedures based on simulated data as well as publicly available experimental methylation and gene expression data. Our comparison included the Boruta algorithm, the Vita method, recurrent relative variable importance, a permutation approach and its parametric variant (Altmann) as well as recursive feature elimination (RFE). In our simulation studies, Boruta was the most powerful approach, followed closely by the Vita method. Both approaches demonstrated similar stability in variable selection, while Vita was the most robust approach under a pure null model without any predictor variables related to the outcome. In the analysis of the different experimental data sets, Vita demonstrated slightly better stability in variable selection and was less computationally intensive than Boruta.In conclusion, we recommend the Boruta and Vita approaches for the analysis of high-dimensional data sets. Vita is considerably faster than Boruta and thus more suitable for large data sets, but only Boruta can also be applied in low-dimensional settings. © The Author 2017. Published by Oxford University Press.

48 CFR 715.370 - Alternative source selection procedures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... selection procedures. 715.370 Section 715.370 Federal Acquisition Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT CONTRACTING METHODS AND CONTRACT TYPES CONTRACTING BY NEGOTIATION Source Selection 715.370 Alternative source selection procedures. The following selection procedures may be used, when...

There is no silver bullet--a guide to low-level data transforms and normalisation methods for microarray data.

PubMed

Kreil, David P; Russell, Roslin R

2005-03-01

To overcome random experimental variation, even for simple screens, data from multiple microarrays have to be combined. There are, however, systematic differences between arrays, and any bias remaining after experimental measures to ensure consistency needs to be controlled for. It is often difficult to make the right choice of data transformation and normalisation methods to achieve this end. In this tutorial paper we review the problem and a selection of solutions, explaining the basic principles behind normalisation procedures and providing guidance for their application.

Dealing with correlated choices: how a spin-glass model can help political parties select their policies.

PubMed

Moore, M A; Katzgraber, Helmut G

2014-10-01

Starting from preferences on N proposed policies obtained via questionnaires from a sample of the electorate, an Ising spin-glass model in a field can be constructed from which a political party could find the subset of the proposed policies which would maximize its appeal, form a coherent choice in the eyes of the electorate, and have maximum overlap with the party's existing policies. We illustrate the application of the procedure by simulations of a spin glass in a random field on scale-free networks.

An updated meta-analysis on the effectiveness of preoperative prophylactic antibiotics in patients undergoing breast surgical procedures.

PubMed

Sajid, Muhammad S; Hutson, Kristian; Akhter, Naved; Kalra, Lorain; Rapisarda, Ignacio F; Bonomi, Ricardo

2012-01-01

To systematically analyze published randomized trials on the effectiveness of preoperative prophylactic antibiotics in patients undergoing breast surgical procedures. Trials on the effectiveness of preoperative prophylactic antibiotics in patients undergoing breast surgery were selected and analyzed to generate summated data (expressed as risk ratio [RR]) by using RevMan 5.0. Nine randomized controlled trials encompassing 3720 patients undergoing breast surgery were retrieved from the electronic databases. The antibiotics group comprised a total of 1857 patients and non-antibiotics group, 1863 patients. There was no heterogeneity [χ(2) = 7.61, d.f. = 7, p < 0.37; I(2) = 8%] amongst trials. Therefore, in the fixed-effects model (RR, 0.64; 95% CI, 0.50-0.83; z = 3.48; p < 0.0005), the use of preoperative prophylactic antibiotics in patients undergoing breast surgical procedures was statistically significant in reducing the incidence of surgical site infection (SSI). Furthermore, in the fixed-effects model (RR, 1.30; 95% CI, 0.89-1.90; z = 1.37; p < 0.17), adverse reactions secondary to the use of prophylactic antibiotics was not statistically significant between the two groups. Preoperative prophylactic antibiotics significantly reduce the risk of SSI after breast surgical procedures. The risk of adverse reactions from prophylactic antibiotic administration is not significant in these patients. Therefore, preoperative prophylactic antibiotics in breast surgery patients may be routinely administered. Further research is required, however, on risk stratification for SSI, timing and duration of prophylaxis, and the need for prophylaxis in patients undergoing breast reconstruction versus no reconstruction. © 2012 Wiley Periodicals, Inc.

Use of Noninvasive Ventilation During Feeding Tube Placement.

PubMed

Banfi, Paolo; Volpato, Eleonora; Valota, Chiara; D'Ascenzo, Salvatore; Alunno, Chiara Bani; Lax, Agata; Nicolini, Antonello; Ticozzi, Nicola; Silani, Vincenzo; Bach, John R

2017-11-01

Parenteral nutrition is indicated in amyotrophic lateral sclerosis (ALS) when dysphagia, loss of appetite, and difficulty protecting the airways cause malnutrition, severe weight loss, dehydration, and increased risk of aspiration pneumonia. The aim of this review is to compare percutaneous endoscopic gastrostomy (PEG), radiologically inserted G-tube (RIG), and percutaneous radiologic gastrostomy (PRG) in patients with ALS, performed with or without noninvasive ventilation (NIV). We searched PubMed, MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), the EBSCO Online Research Database, and Scopus up to December 2015. A priori selection included all randomized controlled trials (RCTs), quasi-randomized trials, and prospective and retrospective studies. The primary outcome was 30-d survival. We found no RCTs or quasi-RCTs. Seven studies about the implementation of the PEG/RIG procedure during the use of NIV and 5 studies without NIV were included. In another study of 59 subjects undergoing open gastrostomy, all with vital capacity < 30% of normal, 18 of whom were dependent on continuous NIV at full ventilatory support settings, there were no respiratory complications. Thus, the use of NIV during the implementation of these procedures, especially when used at full ventilatory support settings of pressure preset 18-25 cm H 2 O, can support alveolar ventilation before, during, and after the procedures and prevent respiratory complications. The procedures investigated appear equivalent, but the methodological quality of the studies could be improved. Possible benefits with regard to nutrition parameters, quality of life, and psychological features need to be further investigated. Copyright © 2017 by Daedalus Enterprises.

Clinical recommendation for treatment planning of sinus augmentation procedures by using presurgical CAT scan images: a preliminary report.

PubMed

Kutkut, Ahmad M; Andreana, Sebastiano; Kim, Hyeong-Ll; Monaco, Edward

2011-12-01

To propose a clinical recommendation based on anatomy of maxillary sinus before sinus augmentation procedure using presurgical computerized axial tomography (CAT) scan images. CAT scan images were randomly selected from previous completed implant cases. Proposed area for the lateral window osteotomy was outlined on the panorex image of the CAT scan. Sagittal section on the CAT scan that was in the center of the outlined window was selected for sinus measurement analysis. On CAT scan, 2 lines were drawn to measure the dimensions of sinus. One line measured the horizontal width and the other line measured the vertical height. Based on the measurement data, a classification of the maxillary sinus anatomy was proposed. Narrow sinus cavity indicates favorable type anatomy in terms of bone regeneration healing and wide sinus cavity as less favorable anatomy for patient treatment planning. A narrow sinus and greater exposure to the blood supply should require shorter healing times after grafting. Conversely, wider sinus cavities and less exposure to the blood supply would require a longer healing time before implant placement.

Endometrial 'scratching': what the data show.

PubMed

Santamaria, Xavier; Katzorke, Nora; Simón, Carlos

2016-08-01

Since its first description in 2003, the endometrial scratching procedure has been the topic of over 1000 studies. This procedure, used to improve endometrial receptivity for assisted reproduction, is accessible - any gynecologist can easily perform it - and has been adapted into clinical routine by some reproductive units. However, the available data are controversial, and no biological plausibility exists to support the use of this intervention. This study aims to critically review the existing data, focusing on the last 2 years, regarding the efficiency of endometrial scratching. A total of five randomized controlled studies, one meta-analysis, and a systematic review related to endometrial scratching/injury were published in 2014 and 2015. Considerable heterogeneity exists among these studies regarding the selected population, type of treatment, and even timing and devices used to perform the endometrial injury. Importantly, none of these studies reported improved reproductive outcomes in terms of live birth rates following endometrial scratching. Overall, data from properly designed and powered randomized controlled studies demonstrate no beneficial effect of this intervention that is based on unknown biological effects. Endometrial scratching produces pain, costs money, and the side-effects of systematic scratching in the production of Asherman syndrome remain to be seen. Think before scratching.

Robotic Surgery in Gynecology: An Updated Systematic Review

PubMed Central

Weinberg, Lori; Rao, Sanjay; Escobar, Pedro F.

2011-01-01

The introduction of da Vinci Robotic Surgery to the field of Gynecology has resulted in large changes in surgical management. The robotic platform allows less experienced laparoscopic surgeons to perform more complex procedures. In general gynecology and reproductive gynecology, the robot is being increasingly used for procedures such as hysterectomies, myomectomies, adnexal surgery, and tubal anastomosis. Among urogynecology the robot is being utilized for sacrocolopexies. In the field of gynecologic oncology, the robot is being increasingly used for hysterectomies and lymphadenectomies in oncologic diseases. Despite the rapid and widespread adoption of robotic surgery in gynecology, there are no randomized trials comparing its efficacy and safety to other traditional surgical approaches. Our aim is to update previously published reviews with a focus on only comparative observational studies. We determined that, with the right amount of training and skill, along with appropriate patient selection, robotic surgery can be highly advantageous. Patients will likely have less blood loss, less post-operative pain, faster recoveries, and fewer complications compared to open surgery and potentially even laparoscopy. However, until larger, well-designed observational studies or randomized control trials are completed which report long-term outcomes, we cannot definitively state the superiority of robotic surgery over other surgical methods. PMID:22190948

[Robotic surgery in gynecology].

PubMed

Csorba, Roland

2012-06-24

Minimally invasive surgery has revolutionized gynecological interventions over the past 30 years. The introduction of the da Vinci robotic surgery in 2005 has resulted in large changes in surgical management. The robotic platform allows less experienced laparoscopic surgeons to perform more complex procedures. It can be utilized mainly in general gynecology and reproductive gynecology. The robot is being increasingly used for procedures such as hysterectomy, myomectomy, adnexal surgery, and tubal anastomosis. In urogynecology, the robot is being utilized for sacrocolopexy as well. In the field of gynecologic oncology, the robot is being increasingly used for hysterectomy and lymphadenectomy in oncologic diseases. Despite the rapid and widespread adaption of robotic surgery in gynecology, there are no randomized trials comparing its efficacy and safety to other traditional surgical approaches. This article presents the development, technical aspects and indications of robotic surgery in gynecology, based on the previously published reviews. Robotic surgery can be highly advantageous with the right amount of training, along with appropriate patient selection. Patients will have less blood loss, less post-operative pain, faster recovery, and fewer complications compared to open surgery and laparoscopy. However, until larger randomized control trials are completed which report long-term outcomes, robotic surgery cannot be stated to have priority over other surgical methods.

The appropriateness of use of percutaneous transluminal coronary angioplasty in Spain.

PubMed

Aguilar, M D; Fitch, K; Lázaro, P; Bernstein, S J

2001-05-01

The rapid increase in the number of percutaneous transluminal coronary angioplasty (PTCA) procedures performed in Spain in recent years raises questions about how appropriately this procedure is being used. To examine this issue, we studied the appropriateness of use of PTCA in Spanish patients and factors associated with inappropriate use. We applied criteria for the appropriate use of PTCA developed by an expert panel of Spanish cardiologists and cardiovascular surgeons to a random sample of 1913 patients undergoing PTCA in Spain in 1997. The patients were selected through a two-step sampling process, stratifying by hospital type (public/private) and volume of procedures (low/medium/high). We examined the association between inappropriate use of PTCA and different clinical and sociodemographic factors. Overall, 46% of the PTCA procedures were appropriate, 31% were uncertain and 22% were inappropriate. Two factors contributing to inappropriate use were patients' receipt of less than optimal medical therapy and their failure to undergo stress testing. Institutional type and volume of procedures were not significantly related with inappropriate use. One of every five PTCA procedures in Spain is done for inappropriate reasons. Assuring that patients receive optimal medical therapy and undergo stress testing when indicated could contribute to more appropriate use of PTCA.

Effectiveness of CO2 laser with subcision in patients with acne scars.

PubMed

Anupama, Y G; Wahab, Afthab Jameela

2016-11-01

Post-acne facial scarring has always been a challenge to treat. It requires multiple therapeutic modalities as single modality is not hundred percent effective. Therefore, we have combined CO 2 laser resurfacing with subcision in patients with acne scars for better results. The aim is to study the effectiveness and side effects of CO 2 laser with subcision in patients with atrophic acne scars. Fifty patients were selected for the study. Baseline grading was done with Goodman and Baron grading system. Twenty-five patients were randomly selected for subcision followed by CO 2 laser and the remaining patients were selected for CO 2 laser alone. The treatment was done for four sessions at 4-week interval. Clinical photographs were obtained for evaluation. CO 2 laser with subcision showed excellent response in grade-2 and -3 acne scars. Statistically there is a significant difference between CO 2 laser following subcision and CO 2 laser alone at 5% level (p < 0.05). Both procedures were well tolerated with minimal side effects. The highly versatile CO 2 laser is useful for treating acne scars. Subcision prior to the CO 2 laser procedure showed better improvement when compared to CO 2 laser alone. Thus, in acne scars, multiple therapeutic modalities achieve better results.

Clinical evaluation of selected Yogic procedures in individuals with low back pain

PubMed Central

Pushpika Attanayake, A. M.; Somarathna, K. I. W. K.; Vyas, G. H.; Dash, S. C.

2010-01-01

The present study has been conducted to evaluate selected yogic procedures on individuals with low back pain. The understanding of back pain as one of the commonest clinical presentations during clinical practice made the path to the present study. It has also been calculated that more than three-quarters of the world's population experience back pain at some time in their lives. Twelve patients were selected and randomly divided into two groups, viz., group A yogic group and group B control group. Advice for life style and diet was given for all the patients. The effect of the therapy was assessed subjectively and objectively. Particular scores drawn for yogic group and control group were individually analyzed before and after treatment and the values were compared using standard statistical protocols. Yogic intervention revealed 79% relief in both subjective and objective parameters (i.e., 7 out of 14 parameters showed statistically highly significant P < 0.01 results, while 4 showed significant results P < 0.05). Comparative effect of yogic group and control group showed 79% relief in both subjective and objective parameters. (i.e., total 6 out of 14 parameters showed statistically highly significant (P < 0.01) results, while 5 showed significant results (P < 0.05). PMID:22131719

Acellular dermal matrix for mucogingival surgery: a meta-analysis.

PubMed

Gapski, Ricardo; Parks, Christopher Allen; Wang, Hom-Lay

2005-11-01

Many clinical studies revealed the effectiveness of acellular dermal matrix (ADM) in the treatment of mucogingival defects. The purpose of this meta-analysis was to compare the efficacy of ADM-based root coverage (RC) and ADM-based increase in keratinized tissues to other commonly used mucogingival surgeries. Meta-analysis was limited to randomized clinical trials (RCT). Articles from January 1, 1990 to October 2004 related to ADM were searched utilizing the MEDLINE database from the National Library of Medicine, the Cochrane Oral Health Group Specialized Trials Registry, and through hand searches of reviews and recent journals. Relevant studies were identified, ranked independently, and mean data from each were weighted accordingly. Selected outcomes were analyzed using a meta-analysis software program. The significant estimates of the treatment effects from different trials were assessed by means of Cochrane's test of heterogeneity. 1) Few RCT studies were found to compile the data. In summary, selection identified eight RCT that met the inclusion criteria. There were four studies comparing ADM versus a connective tissue graft for root coverage procedures, two studies comparing ADM versus coronally advanced flap (CAF) for root coverage procedures, and two studies comparing ADM to free gingival graft in augmentation of keratinized tissue. 2) There were no statistically significant differences between groups for any of the outcomes measured (recession coverage, keratinized tissue formation, probing depths, and clinical attachment levels). 3) The majority of the analyses demonstrated moderate to high levels of heterogeneity. 4) Considering the heterogeneity values found among the studies, certain trends could be found: a) three out of four studies favored the ADM-RC group for recession coverage; b) a connective tissue graft tended to increase keratinized tissue compared to ADM (0.52-mm difference; P = 0.11); c) there were trends of increased clinical attachment gains comparing ADM to CAF procedures (0.56-mm difference; P = 0.16). Differences in study design and lack of data precluded an adequate and complete pooling of data for a more comprehensive analysis. Therefore, considering the trends presented in this study, there is a need for further randomized clinical studies of ADM procedures in comparison to common mucogingival surgical procedures to confirm our findings. It is difficult to draw anything other than tentative conclusions from this meta-analysis of ADM for mucogingival surgery, primarily because of the weakness in the design and reporting of existing trials.

Using machine learning for sequence-level automated MRI protocol selection in neuroradiology.

PubMed

Brown, Andrew D; Marotta, Thomas R

2018-05-01

Incorrect imaging protocol selection can lead to important clinical findings being missed, contributing to both wasted health care resources and patient harm. We present a machine learning method for analyzing the unstructured text of clinical indications and patient demographics from magnetic resonance imaging (MRI) orders to automatically protocol MRI procedures at the sequence level. We compared 3 machine learning models - support vector machine, gradient boosting machine, and random forest - to a baseline model that predicted the most common protocol for all observations in our test set. The gradient boosting machine model significantly outperformed the baseline and demonstrated the best performance of the 3 models in terms of accuracy (95%), precision (86%), recall (80%), and Hamming loss (0.0487). This demonstrates the feasibility of automating sequence selection by applying machine learning to MRI orders. Automated sequence selection has important safety, quality, and financial implications and may facilitate improvements in the quality and safety of medical imaging service delivery.

The effects of predictor method factors on selection outcomes: A modular approach to personnel selection procedures.

PubMed

Lievens, Filip; Sackett, Paul R

2017-01-01

Past reviews and meta-analyses typically conceptualized and examined selection procedures as holistic entities. We draw on the product design literature to propose a modular approach as a complementary perspective to conceptualizing selection procedures. A modular approach means that a product is broken down into its key underlying components. Therefore, we start by presenting a modular framework that identifies the important measurement components of selection procedures. Next, we adopt this modular lens for reviewing the available evidence regarding each of these components in terms of affecting validity, subgroup differences, and applicant perceptions, as well as for identifying new research directions. As a complement to the historical focus on holistic selection procedures, we posit that the theoretical contributions of a modular approach include improved insight into the isolated workings of the different components underlying selection procedures and greater theoretical connectivity among different selection procedures and their literatures. We also outline how organizations can put a modular approach into operation to increase the variety in selection procedures and to enhance the flexibility in designing them. Overall, we believe that a modular perspective on selection procedures will provide the impetus for programmatic and theory-driven research on the different measurement components of selection procedures. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The Effect of Random Error on Diagnostic Accuracy Illustrated with the Anthropometric Diagnosis of Malnutrition

PubMed Central

2016-01-01

Background It is often thought that random measurement error has a minor effect upon the results of an epidemiological survey. Theoretically, errors of measurement should always increase the spread of a distribution. Defining an illness by having a measurement outside an established healthy range will lead to an inflated prevalence of that condition if there are measurement errors. Methods and results A Monte Carlo simulation was conducted of anthropometric assessment of children with malnutrition. Random errors of increasing magnitude were imposed upon the populations and showed that there was an increase in the standard deviation with each of the errors that became exponentially greater with the magnitude of the error. The potential magnitude of the resulting error of reported prevalence of malnutrition were compared with published international data and found to be of sufficient magnitude to make a number of surveys and the numerous reports and analyses that used these data unreliable. Conclusions The effect of random error in public health surveys and the data upon which diagnostic cut-off points are derived to define “health” has been underestimated. Even quite modest random errors can more than double the reported prevalence of conditions such as malnutrition. Increasing sample size does not address this problem, and may even result in less accurate estimates. More attention needs to be paid to the selection, calibration and maintenance of instruments, measurer selection, training & supervision, routine estimation of the likely magnitude of errors using standardization tests, use of statistical likelihood of error to exclude data from analysis and full reporting of these procedures in order to judge the reliability of survey reports. PMID:28030627

Satisfiability Test with Synchronous Simulated Annealing on the Fujitsu AP1000 Massively-Parallel Multiprocessor

NASA Technical Reports Server (NTRS)

Sohn, Andrew; Biswas, Rupak

1996-01-01

Solving the hard Satisfiability Problem is time consuming even for modest-sized problem instances. Solving the Random L-SAT Problem is especially difficult due to the ratio of clauses to variables. This report presents a parallel synchronous simulated annealing method for solving the Random L-SAT Problem on a large-scale distributed-memory multiprocessor. In particular, we use a parallel synchronous simulated annealing procedure, called Generalized Speculative Computation, which guarantees the same decision sequence as sequential simulated annealing. To demonstrate the performance of the parallel method, we have selected problem instances varying in size from 100-variables/425-clauses to 5000-variables/21,250-clauses. Experimental results on the AP1000 multiprocessor indicate that our approach can satisfy 99.9 percent of the clauses while giving almost a 70-fold speedup on 500 processors.

Shunting for normal pressure hydrocephalus (NPH).

PubMed

Esmonde, T; Cooke, S

2002-01-01

Since the condition was first described in 1965, the syndrome of normal pressure hydrocephalus (NPH) has conventionally been managed by placement of a cerebrospinal fluid (CSF) shunt. To determine the effectiveness of shunting procedures in promoting stability or improvement in the neurological symptoms and signs of NPH. The trials were identified from a search of the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group on 26 June 2001 using the terms 'shunt*' and 'normal pressure hydrocephalus'. Studies included for analysis were those involving the placement of a CSF shunt for the treatment of NPH as part of a randomized controlled trial. No data matching the selection criteria were found. No randomized controlled trials of shunt placement versus no shunt were found. There is no evidence to indicate whether placement of a shunt is effective in the management of NPH.

Planetarium instructional efficacy: A research synthesis

NASA Astrophysics Data System (ADS)

Brazell, Bruce D.

The purpose of the current study was to explore the instructional effectiveness of the planetarium in astronomy education using meta-analysis. A review of the literature revealed 46 studies related to planetarium efficacy. However, only 19 of the studies satisfied selection criteria for inclusion in the meta-analysis. Selected studies were then subjected to coding procedures, which extracted information such as subject characteristics, experimental design, and outcome measures. From these data, 24 effect sizes were calculated in the area of student achievement and five effect sizes were determined in the area of student attitudes using reported statistical information. Mean effect sizes were calculated for both the achievement and the attitude distributions. Additionally, each effect size distribution was subjected to homogeneity analysis. The attitude distribution was found to be homogeneous with a mean effect size of -0.09, which was not significant, p = .2535. The achievement distribution was found to be heterogeneous with a statistically significant mean effect size of +0.28, p < .05. Since the achievement distribution was heterogeneous, the analog to the ANOVA procedure was employed to explore variability in this distribution in terms of the coded variables. The analog to the ANOVA procedure revealed that the variability introduced by the coded variables did not fully explain the variability in the achievement distribution beyond subject-level sampling error under a fixed effects model. Therefore, a random effects model analysis was performed which resulted in a mean effect size of +0.18, which was not significant, p = .2363. However, a large random effect variance component was determined indicating that the differences between studies were systematic and yet to be revealed. The findings of this meta-analysis showed that the planetarium has been an effective instructional tool in astronomy education in terms of student achievement. However, the meta-analysis revealed that the planetarium has not been a very effective tool for improving student attitudes towards astronomy.

Comparison of a semi-automatic annotation tool and a natural language processing application for the generation of clinical statement entries.

PubMed

Lin, Ching-Heng; Wu, Nai-Yuan; Lai, Wei-Shao; Liou, Der-Ming

2015-01-01

Electronic medical records with encoded entries should enhance the semantic interoperability of document exchange. However, it remains a challenge to encode the narrative concept and to transform the coded concepts into a standard entry-level document. This study aimed to use a novel approach for the generation of entry-level interoperable clinical documents. Using HL7 clinical document architecture (CDA) as the example, we developed three pipelines to generate entry-level CDA documents. The first approach was a semi-automatic annotation pipeline (SAAP), the second was a natural language processing (NLP) pipeline, and the third merged the above two pipelines. We randomly selected 50 test documents from the i2b2 corpora to evaluate the performance of the three pipelines. The 50 randomly selected test documents contained 9365 words, including 588 Observation terms and 123 Procedure terms. For the Observation terms, the merged pipeline had a significantly higher F-measure than the NLP pipeline (0.89 vs 0.80, p<0.0001), but a similar F-measure to that of the SAAP (0.89 vs 0.87). For the Procedure terms, the F-measure was not significantly different among the three pipelines. The combination of a semi-automatic annotation approach and the NLP application seems to be a solution for generating entry-level interoperable clinical documents. © The Author 2014. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.comFor numbered affiliation see end of article.

Prediction of postoperative pulmonary complications in a population-based surgical cohort.

PubMed

Canet, Jaume; Gallart, Lluís; Gomar, Carmen; Paluzie, Guillem; Vallès, Jordi; Castillo, Jordi; Sabaté, Sergi; Mazo, Valentín; Briones, Zahara; Sanchis, Joaquín

2010-12-01

Current knowledge of the risk for postoperative pulmonary complications (PPCs) rests on studies that narrowly selected patients and procedures. Hypothesizing that PPC occurrence could be predicted from a reduced set of perioperative variables, we aimed to develop a predictive index for a broad surgical population. Patients undergoing surgical procedures given general, neuraxial, or regional anesthesia in 59 hospitals were randomly selected for this prospective, multicenter study. The main outcome was the development of at least one of the following: respiratory infection, respiratory failure, bronchospasm, atelectasis, pleural effusion, pneumothorax, or aspiration pneumonitis. The cohort was randomly divided into a development subsample to construct a logistic regression model and a validation subsample. A PPC predictive index was constructed. Of 2,464 patients studied, 252 events were observed in 123 (5%). Thirty-day mortality was higher in patients with a PPC (19.5%; 95% [CI], 12.5-26.5%) than in those without a PPC (0.5%; 95% CI, 0.2-0.8%). Regression modeling identified seven independent risk factors: low preoperative arterial oxygen saturation, acute respiratory infection during the previous month, age, preoperative anemia, upper abdominal or intrathoracic surgery, surgical duration of at least 2 h, and emergency surgery. The area under the receiver operating characteristic curve was 90% (95% CI, 85-94%) for the development subsample and 88% (95% CI, 84-93%) for the validation subsample. The risk index based on seven objective, easily assessed factors has excellent discriminative ability. The index can be used to assess individual risk of PPC and focus further research on measures to improve patient care.

The best marketing strategy in aesthetic plastic surgery: evaluating patients' preferences by conjoint analysis.

PubMed

Marsidi, Nick; van den Bergh, Maurice W H M; Luijendijk, Roland W

2014-01-01

To provide the best marketing strategy for a private clinic, knowledge of patients' preferences is essential. In marketing, conjoint analysis has been frequently used to calculate which attributes of a product are most valuable to consumers. This study investigates the relative importance of attributes that influence the selection and decision-making process when choosing an aesthetic private clinic, using conjoint analysis. The following attributes were chosen by the senior author (R.W.L.) and a marketing and communications director after a preselection of 25 randomly selected people: relative cost of the procedure, travel time, experience of the plastic surgeon, size of the clinic, method of referral, and online presentation. The attributes were then divided into levels. Using a random factor conducted by SPSS, 18 different scenarios were created and rated online by 150 potential patients before their potential visit or consultation. The patients could rate these scenarios on a scale from 1 to 7 with respect to the likeliness of visiting the clinic. The most important attribute was experience of the surgeon (35.6 percent), followed by method of referral (21.5 percent), travel time (14.2 percent), cost of procedure (12.9 percent), online presentation (9.7 percent), and size of the clinic (6.1 percent). Six of 16 levels gave a negative influence on the decision making. The authors' study shows that the two most important attributes are the experience of the surgeon and the method of referral and that conjoint analysis is effective in determining patients' preferences. It also shows which levels positively or negatively contribute per attribute.

Cost reduction with successful implementation of an antibiotic prophylaxis program in a private hospital in Ribeirão Preto, Brazil.

PubMed

Fonseca, S N; Melon Kunzle, S R; Barbosa Silva, S A; Schmidt, J G; Mele, R R

1999-01-01

To describe the implementation and results of a perioperative antibiotic prophylaxis (PAP) program. A protocol for correct use of PAP was implemented in December 1994. For selected months we measured the PAP protocol compliance of a random sample of clean and clean-contaminated procedures and calculated the cost of incorrect use of PAP. SELLING: A 180-bed general hospital in Ribeirão Preto, Brazil. The cost of unnecessary PAP in the obstetric and gynecologic, cardiothoracic, and orthopedic services dropped from $4,224.54 ($23.47/procedure) in November 1994 to $1,147.24 ($6.17/procedure, January 1995), $544.42 ($3.58/procedure, May 1995), $99.06 ($0.50/procedure, August 1995), and $30 ($0.12/procedure, March 1996). In November 1994, only 13.6% of all surgical procedures were done with correct use of PAP, compared to 59% in January 1995, 73% in August 1995, 78% in March 1996, 92% in November 1996, and 98% in May 1997. Incorrect PAP use wastes resources, which is a particular problem in developing countries. Our program is simple and can be implemented without the use of computers and now is being adopted in other hospitals in our region. We credit the success of our program to the commitment of all participants and to the strong support of the hospital directors.

Evaluation of Bayesian Sequential Proportion Estimation Using Analyst Labels

NASA Technical Reports Server (NTRS)

Lennington, R. K.; Abotteen, K. M. (Principal Investigator)

1980-01-01

The author has identified the following significant results. A total of ten Large Area Crop Inventory Experiment Phase 3 blind sites and analyst-interpreter labels were used in a study to compare proportional estimates obtained by the Bayes sequential procedure with estimates obtained from simple random sampling and from Procedure 1. The analyst error rate using the Bayes technique was shown to be no greater than that for the simple random sampling. Also, the segment proportion estimates produced using this technique had smaller bias and mean squared errors than the estimates produced using either simple random sampling or Procedure 1.

Random Forest as an Imputation Method for Education and Psychology Research: Its Impact on Item Fit and Difficulty of the Rasch Model

ERIC Educational Resources Information Center

Golino, Hudson F.; Gomes, Cristiano M. A.

2016-01-01

This paper presents a non-parametric imputation technique, named random forest, from the machine learning field. The random forest procedure has two main tuning parameters: the number of trees grown in the prediction and the number of predictors used. Fifty experimental conditions were created in the imputation procedure, with different…

Anesthetic effects from low concentrations of proparacaine and benoxinate.

PubMed

Jauregui, M J; Sanders, T J; Polse, K A

1980-01-01

Using double masking procedures, the response to McKay-Marg and Goldmann tonometry of 361 randomly selected patients was determined following the installation of a single dose of either 0.125, 0.25 or 0.5% proparacaine or 0.1, 0.2 or 0.4% benoxinate. Examiners graded the adequacy, patient tolerance and conjunctival hyperemia induced by the drop, while the subjects reported on the sting of the drop, awareness of the tonometer and discomfort after the procedure. The results indicate that 0.25% proparacaine is an effective anesthetic dose on all patients and that 0.2% benoxinate and 0.125% proparacaine would be effective on patients over age 40. The implication of these results is that significantly lower doses of anesthetic can be used which will result in less stinging, reduced hyperemia and shorter duration of action.

SONOlysis in prevention of Brain InfaRctions During Internal carotid Endarterectomy (SONOBIRDIE) trial - study protocol for a randomized controlled trial.

PubMed

Hrbáč, Tomáš; Netuka, David; Beneš, Vladimír; Nosáľ, Vladimír; Kešnerová, Petra; Tomek, Aleš; Fadrná, Táňa; Beneš, Vladimír; Fiedler, Jiří; Přibáň, Vladimír; Brozman, Miroslav; Langová, Kateřina; Herzig, Roman; Školoudík, David

2017-01-17

Carotid endarterectomy (CEA) is a beneficial procedure for selected patients with an internal carotid artery (ICA) stenosis. Surgical risk of CEA varies from between 2 and 15%. The aim of the study is to demonstrate the safety and effectiveness of sonolysis (continual transcranial Doppler monitoring, TCD) using a 2-MHz diagnostic probe with maximal diagnostic energy on the reduction of the incidence of stroke, transient ischemic attack (TIA) and brain infarction detected using magnetic resonance imaging (MRI) by the activation of the endogenous fibrinolytic system during CEA. Design: a multicenter, randomized, double-blind, sham-controlled trial. international, multicenter trial for patients with at least 70% symptomatic or asymptomatic ICA stenosis undergoing CEA. patients with symptomatic or asymptomatic ICA stenosis of at least 70% are candidates for CEA; a sufficient temporal bone window for TCD; aged 40-85 years, functionally independent; provision of signed informed consent. Randomization: consecutive patients will be assigned to the sonolysis or control (sham procedure) group by computer-generated 1:1 randomization. Prestudy calculations showed that a minimum of 704 patients in each group is needed to reach a significant difference with an alpha value of 0.05 (two-tailed) and a beta value of 0.8 assuming that 10% would be lost to follow-up or refuse to participate in the study (estimated 39 endpoints). the primary endpoint is the incidence of stroke or TIA during 30 days after CEA and the incidence of new ischemic lesions on brain MRI performed 24 h after CEA in the sonolysis and control groups. Secondary endpoints are occurrence of death, any stroke, or myocardial infarction within 30 days, changes in cognitive functions 1 year post procedure related to pretreatment scores, and number of new lesions and occurrence of new lesions ≥0.5 mL on post-procedural brain MRI. descriptive statistics and linear/logistic multiple regression models will be performed. Clinical relevance will be measured as relative risk reduction, absolute risk reduction and the number needed to treat. Reduction of the periprocedural complications of CEA using sonolysis as a widely available and cheap method may significantly increase the safety of CEA and extend the indication criteria for CEA. ClinicalTrials.gov, NCT02398734 . Registered on 20 March 2015.

SMS text messaging as a means of increasing recall of therapy goals in brain injury rehabilitation: a single-blind within-subjects trial.

PubMed

Culley, Campbell; Evans, Jonathan J

2010-01-01

A single-blind within-subjects trial was used to test the efficacy of sending SMS text messages to patients with a traumatic brain injury as a means of improving their recall of rehabilitation goals. Eleven participants were recruited from two community-based rehabilitation centres and were sent text messages relating to three randomly selected goals from a selection of six current goals three times per day for 14 days. Participants' recall of their rehabilitation goals was assessed at baseline, seven days, and 14 days via free recall and cued recall procedures. Results showed that goals in the "text" condition were recalled better than goals in the "no text" condition. Practical applications and extensions are discussed.

Proceedings of the Conference on the Design of Experiments in Army Research Development and Testing (26th) Held at New Mexico State University, Las Cruces, New Mexico on 22-24 October 1980.

DTIC Science & Technology

1981-06-01

normality and several types of nonnormality. Overall the rank transformation procedure seems to be the best. The Fisher’s LSD multiple comparisons procedure...the rank transformation procedure appears to maintain power better than Fisher’s LSD or the randomization proce- dures. The conclusion of this study...best. The Fisher’s LSD multiple comparisons procedure in the one way and two way layouts iv compared with a randomization procedure and with the same

Randomized study of surgical prophylaxis in immunocompromised hosts.

PubMed

Lopes, D R; Peres, M P S M; Levin, A S

2011-02-01

Although prophylaxis is current practice, there are no randomized controlled studies evaluating preoperative antimicrobial prophylaxis in dental procedures in patients immunocompromised by chemotherapy or organ transplants. To evaluate prophylaxis in dental-invasive procedures in patients with cancer or solid organ transplants, 414 patients were randomized to receive one oral 500-mg dose 2 hours before the procedure (1-dose group) or a 500-mg dose 2 hours before the procedure and an additional dose 8 hours later (2-dose group). Procedures were exodontia or periodontal scaling/root planing. Follow-up was 4 weeks. No deaths or surgical site infections occurred. Six patients (1.4%) presented with use of pain medication > 3 days or hospitalization during follow-up: 4 of 207 (2%) in the 1-dose group and 2 of 207 (1%) in the 2-dose group (relative risk, 2.02; 95% confidence interval, 0.37-11.15). In conclusion, no statistically significant difference occurred in outcome using 1 or 2 doses of prophylactic amoxicillin for invasive dental procedures in immunocompromised patients.

Model selection with multiple regression on distance matrices leads to incorrect inferences.

PubMed

Franckowiak, Ryan P; Panasci, Michael; Jarvis, Karl J; Acuña-Rodriguez, Ian S; Landguth, Erin L; Fortin, Marie-Josée; Wagner, Helene H

2017-01-01

In landscape genetics, model selection procedures based on Information Theoretic and Bayesian principles have been used with multiple regression on distance matrices (MRM) to test the relationship between multiple vectors of pairwise genetic, geographic, and environmental distance. Using Monte Carlo simulations, we examined the ability of model selection criteria based on Akaike's information criterion (AIC), its small-sample correction (AICc), and the Bayesian information criterion (BIC) to reliably rank candidate models when applied with MRM while varying the sample size. The results showed a serious problem: all three criteria exhibit a systematic bias toward selecting unnecessarily complex models containing spurious random variables and erroneously suggest a high level of support for the incorrectly ranked best model. These problems effectively increased with increasing sample size. The failure of AIC, AICc, and BIC was likely driven by the inflated sample size and different sum-of-squares partitioned by MRM, and the resulting effect on delta values. Based on these findings, we strongly discourage the continued application of AIC, AICc, and BIC for model selection with MRM.

Comparison of two surgical procedures for use of the acellular dermal matrix graft in the treatment of gingival recessions: a randomized controlled clinical study.

PubMed

Felipe, Maria Emília M C; Andrade, Patrícia F; Grisi, Marcio F M; Souza, Sérgio L S; Taba, Mário; Palioto, Daniela B; Novaes, Arthur B

2007-07-01

The aim of this randomized, controlled, clinical investigation was to compare two surgical techniques for root coverage with the acellular dermal matrix graft to evaluate which technique provided better root coverage, a better esthetic result, and less postoperative discomfort. Fifteen patients with bilateral Miller Class I or II gingival recessions were selected. Fifteen pairs of recessions were treated and assigned randomly to the test group, and the contralateral recessions were assigned to the control group. The control group was treated with a broader flap and vertical releasing incisions; the test group was treated with the proposed surgical technique, without vertical releasing incisions. The clinical parameters evaluated were probing depth, relative clinical attachment level, gingival recession (GR), width of keratinized tissue, thickness of keratinized tissue, esthetic result, and pain evaluation. The measurements were taken before the surgeries and after 6 months. At baseline, all parameters were similar for both groups. At 6 months, a statistically significant greater reduction in GR favored the control group. The percentage of root coverage was 68.98% and 84.81% for the test and control groups, respectively. The esthetic result was equivalent between the groups, and all patients tolerated both procedures well. Both techniques provided significant root coverage, good esthetic results, and similar levels of postoperative discomfort. However, the control technique had statistically significantly better results for root coverage of localized gingival recessions.

Incidence of Postoperative Pain after Single Visit and Two Visit Root Canal Therapy: A Randomized Controlled Trial

PubMed Central

Joshi, Sonal B.; Bhagwat, S.V; Patil, Sanjana A

2016-01-01

Introduction Root Canal Treatment (RCT) has become a mainstream procedure in dentistry. A successful RCT is presented by absence of clinical signs and symptoms in teeth without any radiographic evidence of periodontal involvement. Completing this procedure in one visit or multiple visits has long been a topic of discussion. Aim To evaluate the incidence of postoperative pain after root canal therapy performed in single visit and two visits. Material and Methods An unblinded/ open label randomized controlled trial was carried out in the endodontic department of the Dental Institute, where 78 patients were recruited from the regular pool of patients. A total of 66 maxillary central incisors requiring root canal therapy fulfilled the inclusion and exclusion criteria. Using simple randomization by biased coin randomization method, the selected patients were assigned into two groups: group A (n=33) and group B (n=33). Single visit root canal treatment was performed for group A and two visit root canal treatment for group B. Independent sample t-test was used for statistical analysis. Results Thirty three patients were allotted to group A where endodontic treatment was completed in single visit while 33 patients were allotted to group B where endodontic treatment was completed in two visits. One patient dropped-out from Group A. Hence in Group A, 32 patients were analysed while in Group B, 33 patients were analysed. After 6 hours, 12 hours and 24 hours of obturation, pain was significantly higher in Group B as compared to Group A. However, there was no significant difference in the pain experienced by the patients 48 hours after treatment in both the groups. Conclusion Incidence of pain after endodontic treatment being performed in one-visit or two-visits is not significantly different. PMID:27437339

Surgical treatment of hepatocellular carcinoma: evidence-based outcomes.

PubMed

Yamazaki, Shintaro; Takayama, Tadatoshi

2008-02-07

Surgeons may be severely criticized from the perspective of evidence-based medicine because the majority of surgical publications appear not to be convincing. In the top nine surgical journals in 1996, half of the 175 publications refer to pilot studies lacking a control group, 18% to animal experiments, and only 5% to randomized controlled trials (RCT). There are five levels of clinical evidence: level 1 (randomized controlled trial), level 2 (prospective concurrent cohort study), level 3 (retrospective historical cohort study), level 4 (pre-post study), and level 5 (case report). Recently, a Japanese evidence-based guideline for the surgical treatment of hepatocellular carcinoma (HCC) was made by a committee (Chairman, Professor Makuuchi and five members). We searched the literature using the Medline Dialog System with four keywords: HCC, surgery, English papers, in the last 20 years. A total of 915 publications were identified systematically reviewed. At the first selection (in which surgery-dominant papers were selected), 478 papers survived. In the second selection (clearly concluded papers), 181 papers survived. In the final selection (clinically significant papers), 100 papers survived. The evidence level of the 100 surviving papers is shown here: level-1 papers (13%), level-2 papers (11%), level-3 papers (52%), and level-4 papers (24%); therefore, there were 24% prospective papers and 76% retrospective papers. Here, we present a part of the guideline on the five main surgical issues: indication to operation, operative procedure, peri-operative care, prognostic factor, and post-operative adjuvant therapy.

Surgical treatment of hepatocellular carcinoma: Evidence-based outcomes

PubMed Central

Yamazaki, Shintaro; Takayama, Tadatoshi

2008-01-01

Surgeons may be severely criticized from the perspective of evidence-based medicine because the majority of surgical publications appear not to be convincing. In the top nine surgical journals in 1996, half of the 175 publications refer to pilot studies lacking a control group, 18% to animal experiments, and only 5% to randomized controlled trials (RCT). There are five levels of clinical evidence: level 1 (randomized controlled trial), level 2 (prospective concurrent cohort study), level 3 (retrospective historical cohort study), level 4 (pre-post study), and level 5 (case report). Recently, a Japanese evidence-based guideline for the surgical treatment of hepatocellular carcinoma (HCC) was made by a committee (Chairman, Professor Makuuchi and five members). We searched the literature using the Medline Dialog System with four keywords: HCC, surgery, English papers, in the last 20 years. A total of 915 publications were identified systematically reviewed. At the first selection (in which surgery-dominant papers were selected), 478 papers survived. In the second selection (clearly concluded papers), 181 papers survived. In the final selection (clinically significant papers), 100 papers survived. The evidence level of the 100 surviving papers is shown here: level-1 papers (13%), level-2 papers (11%), level-3 papers (52%), and level-4 papers (24%); therefore, there were 24% prospective papers and 76% retrospective papers. Here, we present a part of the guideline on the five main surgical issues: indication to operation, operative procedure, peri-operative care, prognostic factor, and post-operative adjuvant therapy. PMID:18205256

Contrasting lexical similarity and formal definitions in SNOMED CT: consistency and implications.

PubMed

Agrawal, Ankur; Elhanan, Gai

2014-02-01

To quantify the presence of and evaluate an approach for detection of inconsistencies in the formal definitions of SNOMED CT (SCT) concepts utilizing a lexical method. Utilizing SCT's Procedure hierarchy, we algorithmically formulated similarity sets: groups of concepts with similar lexical structure of their fully specified name. We formulated five random samples, each with 50 similarity sets, based on the same parameter: number of parents, attributes, groups, all the former as well as a randomly selected control sample. All samples' sets were reviewed for types of formal definition inconsistencies: hierarchical, attribute assignment, attribute target values, groups, and definitional. For the Procedure hierarchy, 2111 similarity sets were formulated, covering 18.1% of eligible concepts. The evaluation revealed that 38 (Control) to 70% (Different relationships) of similarity sets within the samples exhibited significant inconsistencies. The rate of inconsistencies for the sample with different relationships was highly significant compared to Control, as well as the number of attribute assignment and hierarchical inconsistencies within their respective samples. While, at this time of the HITECH initiative, the formal definitions of SCT are only a minor consideration, in the grand scheme of sophisticated, meaningful use of captured clinical data, they are essential. However, significant portion of the concepts in the most semantically complex hierarchy of SCT, the Procedure hierarchy, are modeled inconsistently in a manner that affects their computability. Lexical methods can efficiently identify such inconsistencies and possibly allow for their algorithmic resolution. Copyright © 2013 Elsevier Inc. All rights reserved.

Aromatherapy for reducing colonoscopy related procedural anxiety and physiological parameters: a randomized controlled study.

PubMed

Hu, Pei-Hsin; Peng, Yen-Chun; Lin, Yu-Ting; Chang, Chi-Sen; Ou, Ming-Chiu

2010-01-01

Colonoscopy is generally tolerated, some patients regarding the procedure as unpleasant and painful and generally performed with the patient sedated and receiving analgesics. The effect of sedation and analgesia for colonoscopy is limited. Aromatherapy is also applied to gastrointestinal endoscopy to reduce procedural anxiety. There is lack of information about aromatherapy specific for colonoscopy. In this study, we aimed to performed a randomized controlled study to investigate the effect of aromatherapy on relieve anxiety, stress and physiological parameters of colonoscopy. A randomized controlled trail was carried out and collected in 2009 and 2010. The participants were randomized in two groups. Aromatherapy was then carried out by inhalation of Sunflower oil (control group) and Neroli oil (Experimental group). The anxiety index was evaluated by State Trait Anxiety Inventory-state (STAI-S) score before aromatherapy and after colonoscopy as well as the pain index for post-procedural by visual analogue scale (VAS). Physiological indicators, such as blood pressure (systolic and diastolic blood pressure), heart rate and respiratory rate were evaluated before and after aromatherapy. Participates in this study were 27 subjects, 13 in control group and 14 in Neroli group with average age 52.26 +/- 17.79 years. There was no significance of procedural anxiety by STAI-S score and procedural pain by VAS. The physiological parameters showed a significant lower pre- and post-procedural systolic blood pressure in Neroli group than control group. Aromatic care for colonoscopy, although with no significant effect on procedural anxiety, is an inexpensive, effective and safe pre-procedural technique that could decrease systolic blood pressure.

Brainstorming: weighted voting prediction of inhibitors for protein targets.

PubMed

Plewczynski, Dariusz

2011-09-01

The "Brainstorming" approach presented in this paper is a weighted voting method that can improve the quality of predictions generated by several machine learning (ML) methods. First, an ensemble of heterogeneous ML algorithms is trained on available experimental data, then all solutions are gathered and a consensus is built between them. The final prediction is performed using a voting procedure, whereby the vote of each method is weighted according to a quality coefficient calculated using multivariable linear regression (MLR). The MLR optimization procedure is very fast, therefore no additional computational cost is introduced by using this jury approach. Here, brainstorming is applied to selecting actives from large collections of compounds relating to five diverse biological targets of medicinal interest, namely HIV-reverse transcriptase, cyclooxygenase-2, dihydrofolate reductase, estrogen receptor, and thrombin. The MDL Drug Data Report (MDDR) database was used for selecting known inhibitors for these protein targets, and experimental data was then used to train a set of machine learning methods. The benchmark dataset (available at http://bio.icm.edu.pl/∼darman/chemoinfo/benchmark.tar.gz ) can be used for further testing of various clustering and machine learning methods when predicting the biological activity of compounds. Depending on the protein target, the overall recall value is raised by at least 20% in comparison to any single machine learning method (including ensemble methods like random forest) and unweighted simple majority voting procedures.

Mirnacle: machine learning with SMOTE and random forest for improving selectivity in pre-miRNA ab initio prediction.

PubMed

Marques, Yuri Bento; de Paiva Oliveira, Alcione; Ribeiro Vasconcelos, Ana Tereza; Cerqueira, Fabio Ribeiro

2016-12-15

MicroRNAs (miRNAs) are key gene expression regulators in plants and animals. Therefore, miRNAs are involved in several biological processes, making the study of these molecules one of the most relevant topics of molecular biology nowadays. However, characterizing miRNAs in vivo is still a complex task. As a consequence, in silico methods have been developed to predict miRNA loci. A common ab initio strategy to find miRNAs in genomic data is to search for sequences that can fold into the typical hairpin structure of miRNA precursors (pre-miRNAs). The current ab initio approaches, however, have selectivity issues, i.e., a high number of false positives is reported, which can lead to laborious and costly attempts to provide biological validation. This study presents an extension of the ab initio method miRNAFold, with the aim of improving selectivity through machine learning techniques, namely, random forest combined with the SMOTE procedure that copes with imbalance datasets. By comparing our method, termed Mirnacle, with other important approaches in the literature, we demonstrate that Mirnacle substantially improves selectivity without compromising sensitivity. For the three datasets used in our experiments, our method achieved at least 97% of sensitivity and could deliver a two-fold, 20-fold, and 6-fold increase in selectivity, respectively, compared with the best results of current computational tools. The extension of miRNAFold by the introduction of machine learning techniques, significantly increases selectivity in pre-miRNA ab initio prediction, which optimally contributes to advanced studies on miRNAs, as the need of biological validations is diminished. Hopefully, new research, such as studies of severe diseases caused by miRNA malfunction, will benefit from the proposed computational tool.

29 CFR 1607.3 - Discrimination defined: Relationship between use of selection procedures and discrimination.

Code of Federal Regulations, 2013 CFR

2013-07-01

... selection procedures and discrimination. 1607.3 Section 1607.3 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION UNIFORM GUIDELINES ON EMPLOYEE SELECTION PROCEDURES (1978) General Principles § 1607.3 Discrimination defined: Relationship between use of selection procedures and...

In situ medical simulation investigation of emergency department procedural sedation with randomized trial of experimental bedside clinical process guidance intervention.

PubMed

Siegel, Nathan A; Kobayashi, Leo; Dunbar-Viveiros, Jennifer A; Devine, Jeffrey; Al-Rasheed, Rakan S; Gardiner, Fenwick G; Olsson, Krister; Lai, Stella; Jones, Mark S; Dannecker, Max; Overly, Frank L; Gosbee, John W; Portelli, David C; Jay, Gregory D

2015-06-01

Patient safety during emergency department procedural sedation (EDPS) can be difficult to study. Investigators sought to delineate and experimentally assess EDPS performance and safety practices of senior-level emergency medicine residents through in situ simulation. Study sessions used 2 pilot-tested EDPS scenarios with critical action checklists, institutional forms, embedded probes, and situational awareness questionnaires. An experimental informatics system was separately developed for bedside EDPS process guidance. Postgraduate year 3 and 4 subjects completed both scenarios in randomized order; only experimental subjects were provided with the experimental system during second scenarios. Twenty-four residents were recruited into a control group (n = 12; 6.2 ± 7.4 live EDPS experience) and experimental group (n = 12; 11.3 ± 8.2 live EDPS experience [P = 0.10]). Critical actions for EDPS medication selection, induction, and adverse event recognition with resuscitation were correctly performed by most subjects. Presedation evaluations, sedation rescue preparation, equipment checks, time-outs, and documentation were frequently missed. Time-outs and postsedation assessments increased during second scenarios in the experimental group. Emergency department procedural sedation safety probe detection did not change across scenarios in either group. Situational awareness scores were 51% ± 7% for control group and 58% ± 12% for experimental group. Subjects using the experimental system completed more time-outs and scored higher Simulation EDPS Safety Composite Scores, although without comprehensive improvements in EDPS practice or safety. Study simulations delineated EDPS and assessed safety behaviors in senior emergency medicine residents, who exhibited the requisite medical knowledge base and procedural skill set but lacked some nontechnical skills that pertain to emergency department microsystem functions and patient safety. The experimental system exhibited limited impact only on in-simulation time-out compliance.

Weight Loss Outcomes in Laparoscopic Vertical Sleeve Gastrectomy (LVSG) Versus Laparoscopic Roux-en-Y Gastric Bypass (LRYGB) Procedures: A Meta-Analysis and Systematic Review of Randomized Controlled Trials.

PubMed

Osland, Emma; Yunus, Rossita M; Khan, Shahjahan; Memon, Breda; Memon, Muhammed A

2017-02-01

Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic vertical sleeve gastrectomy (LVSG) have been proposed as cost-effective strategies to manage morbid obesity. The aim of this meta-analysis was to compare the postoperative weight loss outcomes reported in randomized control trials (RCTs) for LVSG versus LRYGB procedures. RCTs comparing the weight loss outcomes following LVSG and LRYGB in adult population between January 2000 and November 2015 were selected from PubMed, Medline, Embase, Science Citation Index, Current Contents, and the Cochrane database. The review was prepared in accordance with Preferred Reporting of Systematic Reviews and Meta-Analyses (PRISMA). Nine unique RCTs described over 10 publications involving a total of 865 patients (LVSG, n=437; LRYGB, n=428) were analyzed. Postoperative follow-up ranged from 3 months to 5 years. Twelve-month excess weight loss (EWL) for LVSG ranged from 69.7% to 83%, and for LRYGB, ranged from 60.5% to 86.4%. A number of studies reported slow weight gain between the second and third years of postoperative follow-up ranging from 1.4% to 4.2%EWL. This trend was seen to continue to 5 years postoperatively (8% to 10%EWL) for both procedures. In conclusion, LRYGB and LVSG are comparable with regards to the weight loss outcomes in the short term, with LRYGB achieving slightly greater weight loss. Slow weight recidivism is observed after the first postoperative year following both procedures. Long-term reporting of outcomes obtained from well-designed studies using intention-to-treat analyses are identified as a major gap in the literature at present.

Changes in Non-Diabetic Comorbid Disease Status Following Laparoscopic Vertical Sleeve Gastrectomy (LVSG) Versus Laparoscopic Roux-En-Y Gastric Bypass (LRYGB) Procedures: a Systematic Review of Randomized Controlled Trials.

PubMed

Osland, Emma; Yunus, Rossita Mohamad; Khan, Shahjahan; Memon, Breda; Memon, Muhammed Ashraf

2017-05-01

Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic vertical sleeve gastrectomy (LVSG) have been proposed as cost-effective strategies to manage obesity-related chronic disease. The aim of this systematic review was to study the peer review literature regarding postoperative nondiabetic comorbid disease resolution or improvement reported from randomized controlled trials (RCTs) comparing LVSG and LRYGB procedures. RCTs comparing postoperative comorbid disease resolution such as hypertension, dyslipidemia, obstructive sleep apnea, joint and musculoskeletal conditions, gastroesophageal reflux disease, and menstrual irregularities following LVSG and LRYGB were included for analysis. The studies were selected from PubMed, Medline, EMBASE, Science Citation Index, Current Contents, and the Cochrane database and reported on at least one comorbidity resolution or improvement. The present work was undertaken according to the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA). The Jadad method for assessment of methodological quality was applied to the included studies. Six RCTs performed between 2005 and 2015 involving a total of 695 patients (LVSG n = 347, LRYGB n = 348) reported on the resolution or improvement of comorbid disease following LVSG and LRYGB procedures. Both bariatric procedures provide effective and almost comparable results in improving or resolving these comorbidities. This systematic review of RCTs suggests that both LVSG and LRYGB are effective in resolving or improving preoperative nondiabetic comorbid diseases in obese patients. While results are not conclusive at this time, LRYGB may provide superior results compared to LVSG in mediating the remission and/or improvement in some conditions such as dyslipidemia and arthritis.

SAS procedures for designing and analyzing sample surveys

USGS Publications Warehouse

Stafford, Joshua D.; Reinecke, Kenneth J.; Kaminski, Richard M.

2003-01-01

Complex surveys often are necessary to estimate occurrence (or distribution), density, and abundance of plants and animals for purposes of re-search and conservation. Most scientists are familiar with simple random sampling, where sample units are selected from a population of interest (sampling frame) with equal probability. However, the goal of ecological surveys often is to make inferences about populations over large or complex spatial areas where organisms are not homogeneously distributed or sampling frames are in-convenient or impossible to construct. Candidate sampling strategies for such complex surveys include stratified,multistage, and adaptive sampling (Thompson 1992, Buckland 1994).

The quality of the new birth certificate data: a validation study in North Carolina.

PubMed Central

Buescher, P A; Taylor, K P; Davis, M H; Bowling, J M

1993-01-01

A random sample of 395 December 1989 North Carolina birth certificates and the corresponding maternal hospital medical records were examined to validate selected items. Reporting was very accurate for birth-weight, Apgar score, and method of delivery; fair to good for tobacco use, prenatal care, weight gain during pregnancy, obstetrical procedures, and events of labor and delivery; and poor for medical history and alcohol use. This study suggests that many of the new birth certificate items will support valid aggregate analyses for maternal and child health research and evaluation. PMID:8342728

Improving the Spatial Prediction of Soil Organic Carbon Stocks in a Complex Tropical Mountain Landscape by Methodological Specifications in Machine Learning Approaches.

PubMed

Ließ, Mareike; Schmidt, Johannes; Glaser, Bruno

2016-01-01

Tropical forests are significant carbon sinks and their soils' carbon storage potential is immense. However, little is known about the soil organic carbon (SOC) stocks of tropical mountain areas whose complex soil-landscape and difficult accessibility pose a challenge to spatial analysis. The choice of methodology for spatial prediction is of high importance to improve the expected poor model results in case of low predictor-response correlations. Four aspects were considered to improve model performance in predicting SOC stocks of the organic layer of a tropical mountain forest landscape: Different spatial predictor settings, predictor selection strategies, various machine learning algorithms and model tuning. Five machine learning algorithms: random forests, artificial neural networks, multivariate adaptive regression splines, boosted regression trees and support vector machines were trained and tuned to predict SOC stocks from predictors derived from a digital elevation model and satellite image. Topographical predictors were calculated with a GIS search radius of 45 to 615 m. Finally, three predictor selection strategies were applied to the total set of 236 predictors. All machine learning algorithms-including the model tuning and predictor selection-were compared via five repetitions of a tenfold cross-validation. The boosted regression tree algorithm resulted in the overall best model. SOC stocks ranged between 0.2 to 17.7 kg m-2, displaying a huge variability with diffuse insolation and curvatures of different scale guiding the spatial pattern. Predictor selection and model tuning improved the models' predictive performance in all five machine learning algorithms. The rather low number of selected predictors favours forward compared to backward selection procedures. Choosing predictors due to their indiviual performance was vanquished by the two procedures which accounted for predictor interaction.

Enumeration procedure for monitoring test microbe populations on inoculated carriers in AOAC use-dilution methods.

PubMed

Tomasino, Stephen F; Fiumara, Rebecca M; Cottrill, Michele P

2006-01-01

The AOAC Use-Dilution methods do not provide procedures to enumerate the test microbe on stainless steel carriers (penicylinders) or guidance on the expected target populations of the test microbe (i.e., a performance standard). This report describes the procedures used by the U.S. Environmental Protection Agency to enumerate the test microbe (carrier counts) associated with conducting the Use-Dilution method with Staphylococcus aureus (Method 955.15) and Pseudomonas aeruginosa (Method 964.02) and the examination of historical data. The carrier count procedure involves the random selection of carriers, shearing bacterial cells from the carrier surface through sonication, and plating of serially diluted inoculum on trypticase soy agar. For each Use-Dilution test conducted, the official AOAC method was strictly followed for carrier preparation, culture initiation, test culture preparation, and carrier inoculation steps. Carrier count data from 78 Use-Dilution tests conducted over a 6-year period were compiled and analyzed. A mean carrier count of 6.6 logs (approximately 4.0 x 10(6) colony-forming units/carrier) was calculated for both S. aureus and P. aeruginosa. Of the mean values, 95% fell within +/- 2 repeatability standard deviations. The enumeration procedure and target carrier counts are desirable for standardizing the Use-Dilution methods, increasing their reproducibility, and ensuring the quality of the data.

Sampling procedures for inventory of commercial volume tree species in Amazon Forest.

PubMed

Netto, Sylvio P; Pelissari, Allan L; Cysneiros, Vinicius C; Bonazza, Marcelo; Sanquetta, Carlos R

2017-01-01

The spatial distribution of tropical tree species can affect the consistency of the estimators in commercial forest inventories, therefore, appropriate sampling procedures are required to survey species with different spatial patterns in the Amazon Forest. For this, the present study aims to evaluate the conventional sampling procedures and introduce the adaptive cluster sampling for volumetric inventories of Amazonian tree species, considering the hypotheses that the density, the spatial distribution and the zero-plots affect the consistency of the estimators, and that the adaptive cluster sampling allows to obtain more accurate volumetric estimation. We use data from a census carried out in Jamari National Forest, Brazil, where trees with diameters equal to or higher than 40 cm were measured in 1,355 plots. Species with different spatial patterns were selected and sampled with simple random sampling, systematic sampling, linear cluster sampling and adaptive cluster sampling, whereby the accuracy of the volumetric estimation and presence of zero-plots were evaluated. The sampling procedures applied to species were affected by the low density of trees and the large number of zero-plots, wherein the adaptive clusters allowed concentrating the sampling effort in plots with trees and, thus, agglutinating more representative samples to estimate the commercial volume.

Emory Angioplasty Versus Surgery Trial (EAST): design, recruitment, and baseline description of patients.

PubMed

King, S B; Lembo, N J; Weintraub, W S; Kosinski, A S; Barnhart, H X; Kutner, M H

1995-03-23

In patients with multivessel coronary artery disease who require revascularization there is uncertainty as to the selection of the appropriate patients for percutaneous transluminal coronary angioplasty (PTCA) as opposed to coronary artery bypass grafting (CABG). To define the relative roles of PTCA and CABG for multivessel disease, 392 patients were randomly assigned to revascularization by PTCA or CABG and followed for 3 years. This is a single-center randomized study in which individual group assignment was known but grouped data remained blinded until a full 3 years of follow-up was complete on all patients. The patients were randomized in 4 strata: (1) 2-vessel disease with 1 lesion per vessel; (2) 2-vessel disease with multiple lesions in at least 1 vessel; (3) 3-vessel disease with 1 lesion per vessel; and (4) 3-vessel disease with multiple lesions in at least 1 vessel. All data were collected on study-specific forms and sent to an independent biostatistical coordinating center for entry into a computerized database. All data will be analyzed by intention-to-treat. The primary endpoint of the trial is the composite of death of any cause, Q-wave myocardial infarction within 3 years, or a large reversible thallium defect at 3 years. Multiple secondary endpoints will include each of the components of the primary endpoint, the need for additional procedures, angiographic status at 1 and 3 years measured by an independent quantitative coronary arteriography laboratory, and measures of quality of life. A total of 5,118 patients were screened, of whom 3,371 were excluded for angiographic reasons, 191 because the angioplasty operators or surgeons believed that the patients were anatomically unsuitable, and 714 for clinical exclusions, leaving 842 eligible patients, of whom 392 were randomized. Of these, 40% had triple-vessel disease and 60% had double-vessel disease. There was no baseline difference between the 2 treatment arms for any clinical or major angiographic variable. This randomized trial will permit an in-depth comparison of coronary angioplasty and coronary surgery in comparable patients suitable for either procedure. Clinical, angiographic, and quality-of-life comparisons will be made and should be helpful in medical decision making between the 2 procedures.

Pulsed Nd:YAG laser selective ablation of surface enamel caries: II. Histology and clinical trials

NASA Astrophysics Data System (ADS)

Harris, David M.; Goodis, Harold E.; White, Joel M.; Arcoria, Charles J.; Simon, James; Burkart, John; Yessik, Michael J.; Myers, Terry D.

2000-03-01

High intensity infrared light from the pulsed Nd:YAG dental laser is absorbed by pigmented carious enamel and not absorbed by normal enamel. Therefore, this system is capable of selective removal of surface enamel caries. Safety and efficacy of the clinical procedure was evaluated in two sets of clinical trials at three dental schools. Carious lesions were randomized to drill or laser treatment. Pulp vitality, surface condition, preparations and restorations were evaluated by blinded evaluators. In Study 1 surface caries were removed from 104 third molars scheduled for extraction. One week post-treatment teeth were extracted and the pulp was examined histologically. In Study 2 90 patients with 422 lesions on 376 teeth were randomized to laser or drill and followed for six months. There were no adverse events and both clinical and histological evaluations of pulp vitality showed no abnormalities. Caries were removed in all conditions. A significantly greater number of preparations in the drill groups vs. laser groups entered dentin (drill equals 11, laser equals 1, p less than 0.001). This indicates that the more conservative laser treatment removed the caries but not the sound enamel below the lesion.

[Clinical study of tissue-selecting therapy in the treatment of mixed hemorrhoids: a single-blind randomized controlled trail].

PubMed

He, Hongyan; He, Ping; Liu, Ning

2014-06-01

To evaluate the clinical efficacy and safety of tissue-selecting therapy (TST) in treatment of mixed hemorrhoids. A single-blind randomized study was carried out. A total of 120 patients with mixed hemorrhoids from January to December 2012 were prospectively enrolled in the study and equally divided into two groups, TST group and procedure for prolapse and hemorrhoids(PPH) group. Surgical data, efficacy and postoperative complications were compared between the two groups. As compared to PPH group, patients in TST group had shorter operation time [(15.9±5.18) min vs. (22.6±7.1) min, P<0.05], lower scores of rectal urgency (0.5±0.2 vs. 1.5±1.4, P<0.05), and shorter hospital stay [(11.2±3.7) d vs. (14.8±3.7) d, P<0.05]. No anastomotic stricture case was found in TST group, while 11 cases(18.3%) developed anastomotic stricture in PPH group. There were no significant differences in effective rate and pain score of first defecation between the two groups. TST is reliable and safe for mixed hemorrhoids with the advantage of simple, rapid recovery and less complications.

Therapist facilitative interpersonal skills and training status: A randomized clinical trial on alliance and outcome.

PubMed

Anderson, Timothy; Crowley, Mary Ellen J; Himawan, Lina; Holmberg, Jennifer K; Uhlin, Brian D

2016-09-01

Therapist effects, independent of the treatment provided, have emerged as a contributor to psychotherapy outcomes. However, past research largely has not identified which therapist factors might be contributing to these effects, though research on psychotherapy implicates relational characteristics. The present Randomized Clinical Trial tested the efficacy of therapists who were selected by their facilitative interpersonal skills (FIS) and training status. Sixty-five clients were selected from 2713 undergraduates using a screening and clinical interview procedure. Twenty-three therapists met with 2 clients for 7 sessions and 20 participants served in a no-treatment control group. Outcome and alliance differences for Training Status were negligible. High FIS therapists had greater pre-post client outcome, and higher rates of change across sessions, than low FIS therapists. All clients treated by therapists improved more than the silent control, but effects were greater with high FIS than low FIS therapists. From the first session, high FIS therapists also had higher alliances than low FIS therapists as well as significant improvements on client-rated alliance. Results were consistent with the hypothesis that therapists' common relational skills are independent contributors to therapeutic alliance and outcome.

Oral Chloral Hydrate Compare with Rectal Thiopental in Pediatric Procedural Sedation and Analgesia; a Randomized Clinical Trial.

PubMed

Azizkhani, Reza; Kanani, Soheila; Sharifi, Ali; Golshani, Keihan; Masoumi, Babak; Ahmadi, Omid

2014-01-01

The increasing use of diagnostic imaging in pediatric medicine has resulted in growing need for procedural sedation and analgesia (PSA) to minimize motion artifacts during procedures. The drug of choice in pediatric PSA was not introduced until now. The aim of the present study was comparison of oral chloral hydrate (OCH) and rectal sodium thiopental (RST) in pediatric PSA. In the present randomized clinical trial, 2-6 years old pediatrics who referred for performing brain computed tomography scan was enrolled and were randomly divided in to two groups. OCH (50mg/kg) and RST (25mg/kg) were prescribed and a trained nurse recorded the time from drug prescription to receiving the conscious sedation (onset of action), the total period which the patient has the Ramsay score≥4 (duration of action), and adverse effect of agents. Mann-Whitney U test and chi-squared test, and Non-parametric analysis of covariance (ANCOVA) were used for comparisons. One hundred and forty children were entered to two groups of OCH and RST, randomly. The patients of two groups had similar age, sex, weight, and baseline vital signs except for diastolic blood pressure (p<0.001). The onset of action in OCH and RST groups were 24.5±6.1and 28.7±5.2 minutes, respectively (p<0.001). Duration of action in OCH and RST groups were 12.9±2.8 minutes and 13.7±2.6 minutes, respectively (p=0.085). Non-parametric ANCOVA revealed that only diastolic blood pressure was affected by drug prescription (p=0.001). In 11(15.7%) patients in RST group, diarrhea was observed during 24 hours (p=0.001). Oxygen desaturation was observed only in two patients, both in OCH group. Each of the sedative has advantages and disadvantages that should be considered when selecting one for inducing short-term sedation. It seems that rectal sodium thiopental and oral chloral hydrate are equally effective in pediatric PSA and based on patient's condition we can administrate one of these agents.

Direct-to-consumer prescription drug advertising and the public.

PubMed

Bell, R A; Kravitz, R L; Wilkes, M S

1999-11-01

Drug manufacturers are intensely promoting their products directly to consumers, but the impact has not been widely studied. Consumers' awareness and understanding of, attitudes toward, and susceptibility to direct-to-consumer (DTC) drug advertising were examined. Random-digit dialing telephone survey with a random household member selection procedure (completion and response rates, 58% and 69%, respectively). Respondents were interviewed while they were at their residences. Complete data were obtained from 329 adults in Sacramento County, California. Outcome measures included awareness of advertisements for 10 selected drugs, misconceptions about DTC advertising, attitudes toward DTC ads, and behavioral responses to such promotions. The influence of demographic characteristics, health status, attitudes, beliefs, and media exposure on awareness and behaviors was examined. On average, respondents were aware of advertisements for 3.7 of the 10 drugs; awareness varied from 8% for Buspar (buspirone) to 72% for Claritin (loratadine). Awareness was associated with prescription drug use, media exposure, positive attitudes toward DTC advertising, poorer health, and insurance status. Substantial misconceptions were revealed; e.g., 43% thought that only "completely safe" drugs could be advertised. Direct-to-consumer advertisements had led one third of respondents to ask their physicians for drug information and one fifth to request a prescription. Direct-to-consumer advertisements are reaching the public, but selectively so, and affecting their behaviors. Implications for public policy are examined.

Direct-to-Consumer Prescription Drug Advertising and the Public

PubMed Central

Bell, Robert A; Kravitz, Richard L; Wilkes, Michael S

1999-01-01

OBJECTIVE Drug manufacturers are intensely promoting their products directly to consumers, but the impact has not been widely studied. Consumers' awareness and understanding of, attitudes toward, and susceptibility to direct-to-consumer (DTC) drug advertising were examined. DESIGN Random-digit dialing telephone survey with a random household member selection procedure (completion and response rates, 58% and 69%, respectively). SETTING Respondents were interviewed while they were at their residences. PARTICIPANTS Complete data were obtained from 329 adults in Sacramento County, California. MEASUREMENTS AND MAIN RESULTS Outcome measures included awareness of advertisements for 10 selected drugs, misconceptions about DTC advertising, attitudes toward DTC ads, and behavioral responses to such promotions. The influence of demographic characteristics, health status, attitudes, beliefs, and media exposure on awareness and behaviors was examined. On average, respondents were aware of advertisements for 3.7 of the 10 drugs; awareness varied from 8% for Buspar (buspirone) to 72% for Claritin (loratadine). Awareness was associated with prescription drug use, media exposure, positive attitudes toward DTC advertising, poorer health, and insurance status. Substantial misconceptions were revealed; e.g., 43% thought that only “completely safe” drugs could be advertised. Direct-to-consumer advertisements had led one third of respondents to ask their physicians for drug information and one fifth to request a prescription. CONCLUSIONS Direct-to-consumer advertisements are reaching the public, but selectively so, and affecting their behaviors. Implications for public policy are examined. PMID:10571712

Frequent users of rural primary care: comparisons with randomly selected users.

PubMed

Mehl-Madrona, L E

1998-01-01

Frequent users of primary care have not been adequately characterized. The unique characteristics of this population was sought--why they come so often, what their care costs, and whether psychosocial factors play a role in their high utilization of health care. The billing system of a rural primary care clinic was used to find the frequency of visits for all patients attending the clinic for the previous 12 months. The 211 most frequent visitors were selected. A comparison group of 250 patients was drawn from the billing records using a random number generator. Charts were reviewed to compare diagnoses (by frequency), number of procedures, amount billed for care, amount received from those billings, number of psychotropic medications prescribed, and response to medication. A subgroup of each group was interviewed to confirm chart review findings and to inquire about personal reasons for coming to the clinic. Compared with patients who were random users, patients who were frequent users were more likely to come from the younger and older age groups, they averaged significantly more emergency department visits and visits to other specialists (P < 0.0001), and they had more mental health problems diagnosed (P < 0.01). Significantly more frequent users were insured by Medicaid and fewer were insured by Medicare. They had more detailed office visits and more laboratory tests. They received twice as much psychotherapy and had a higher percentage of problem-focused office visits. Chart audits and interviews of selected patients revealed that many nonmedical reasons were related to visits in addition to psychosocial stressors. Nonmedical factors are important among the most frequent users of a primary care clinic. Proposals to improve care for frequent users should consider the psychosocial needs of this population.

Surveyed opinion of American trauma, orthopedic, and thoracic surgeons on rib and sternal fracture repair.

PubMed

Mayberry, John C; Ham, L Bruce; Schipper, Paul H; Ellis, Thomas J; Mullins, Richard J

2009-03-01

Rib and sternal fracture repair are controversial. The opinion of surgeons regarding those patients who would benefit from repair is unknown. Members of the Eastern Association for the Surgery of Trauma, the Orthopedic Trauma Association, and thoracic surgeons (THS) affiliated with teaching hospitals in the United States were recruited to complete an electronic survey regarding rib and sternal fracture repair. Two hundred thirty-eight trauma surgeons (TRS), 97 orthopedic trauma surgeons (OTS), and 70 THS completed the survey. Eighty-two percent of TRS, 66% of OTS, and 71% of THS thought that rib fracture repair was indicated in selected patients. A greater proportion of surgeons thought that sternal fracture repair was indicated in selected patients (89% of TRS, 85% of OTS, and 95% of THS). Chest wall defect/pulmonary hernia (58%) and sternal fracture nonunion (>6 weeks) (68%) were the only two indications accepted by a majority of respondents. Twenty-six percent of surgeons reported that they had performed or assisted on a chest wall fracture repair, whereas 22% of surgeons were familiar with published randomized trials of the surgical repair of flail chest. Of surgeons who thought rib fracture or sternal fracture repair was rarely, if ever, indicated, 91% and 95%, respectively, specified that a randomized trial confirming efficacy would be necessary to change their negative opinion. A majority of surveyed surgeons reported that rib and sternal fracture repair is indicated in selected patients; however, a much smaller proportion indicated that they had performed the procedures. The published literature on surgical repair is sparse and unfamiliar to most surgeons. Barriers to surgical repair of rib and sternal fracture include a lack of expertise among TRS, lack of research of optimal techniques, and a dearth of randomized trials.

Standard operating procedures for vascular surgery in erectile dysfunction: revascularization and venous procedures.

PubMed

Sohn, Michael; Hatzinger, Martin; Goldstein, Irwin; Krishnamurti, Sudhakar

2013-01-01

The impact of penile blood supply on erectile function was recognized some 500 years ago. At the turn of the 20th century first results of penile venous ligation were published and in 1973 the first surgical attempts to restore penile arterial inflow were undertaken. Numerous techniques were published in the meantime, but inclusion criteria, patient selection, and success evaluation differed extremely between study groups. To develop evidence-based standard operating procedures (SOPs) for vascular surgery in erectile dysfunction, based on recent state of the art consensus reports and recently published articles in peer-reviewed journals. Based on the recent publication of the consensus process during the 2009 International Consultation on Sexual Medicine in Paris, recommendations are derived for diagnosis and surgical treatment of vascular erectile dysfunction. In addition several recent publications in this field not mentioned in the consensus statements are included in the discussion. The Oxford system of evidence-based review was systematically applied. Due to the generally low level of evidence in this field expert opinions were accepted, if published after a well-defined consensus process in peer-reviewed journals. Referring to penile revascularization it may be concluded, that in the face of missing randomized trials, only recommendations grade D may be given: this kind of surgery may be offered to men less than 55 years, who are nonsmokers, nondiabetic, and demonstrate isolated arterial stenoses in the absence of generalized vascular disease. The evidence level for recommendations concerning penile venous ligations may be even lower. Too many unsolved controversies exist and universal diagnostic criteria for patient selection as well as operative technique selection have not been unequivocally established. This kind of surgery is still considered investigational but may be offered in special situations on an individualized basis in an investigational or research setting after obtaining written consent, using both pre- and postoperatively validated measuring instruments of success evaluation. SOPs for penile revascularization procedures can be developed, concerning a highly selected patient group with isolated arterial stenoses. Based on the available data it is not yet possible to define SOPs for surgical treatment of corporal veno-occlusive dysfunction. © 2012 International Society for Sexual Medicine.

A randomized study of a method for optimizing adolescent assent to biomedical research.

PubMed

Annett, Robert D; Brody, Janet L; Scherer, David G; Turner, Charles W; Dalen, Jeanne; Raissy, Hengameh

2017-01-01

Voluntary consent/assent with adolescents invited to participate in research raises challenging problems. No studies to date have attempted to manipulate autonomy in relation to assent/consent processes. This study evaluated the effects of an autonomy-enhanced individualized assent/consent procedure embedded within a randomized pediatric asthma clinical trial. Families were randomly assigned to remain together or separated during a consent/assent process; the latter we characterize as an autonomy-enhanced assent/consent procedure. We hypothesized that separating adolescents from their parents would improve adolescent assent by increasing knowledge and appreciation of the clinical trial and willingness to participate. Sixty-four adolescent-parent dyads completed procedures. The together versus separate randomization made no difference in adolescent or parent willingness to participate. However, significant differences were found in both parent and adolescent knowledge of the asthma clinical trial based on the assent/consent procedure and adolescent age. The separate assent/consent procedure improved knowledge of study risks and benefits for older adolescents and their parents but not for the younger youth or their parents. Regardless of the assent/consent process, younger adolescents had lower comprehension of information associated with the study medication and research risks and benefits, but not study procedures or their research rights and privileges. The use of an autonomy-enhanced assent/consent procedure for adolescents may improve their and their parent's informed assent/consent without impacting research participation decisions. Traditional assent/consent procedures may result in a "diffusion of responsibility" effect between parents and older adolescents, specifically in attending to key information associated with study risks and benefits.

Views of College Students on Plastic Surgery

PubMed Central

Ahmad, Muhammad; Mohmand, Humayun; Ahmad, Nabila

2013-01-01

BACKGROUND Various studies have been conducted in many countries to determine the perception/awareness about plastic surgery. The present study assessed the views of college students about plastic surgery. METHODS A questionnaire consisted of nine questions regarding the basic knowledge about plastic surgery was randomly distributed among college students. The students were given 20 minutes to fill out the forms. RESULTS A total of 250 male and 250 female college students were randomly included in the study. The mean age of the male students was 21.1 years as compared to 20.7 years of female students. The top five conditions named were related to hair (89.8%) followed by face scars (88%). The most common procedure named by the students was liposuction (88.2%) followed by hair transplantation. 80.2% of the students opted not to be a plastic surgeon if given an opportunity to select the profession. 33.8% of the students had seen some kinds of plastic surgery operation. Only 5.6% of the students (3.4% male and 2.2% female) had seen some kinds of plastic surgery procedure. 68% of male students and 48% of female students wished to have a plastic surgery procedure sometime in their lives. Majority of the students (88%) got the information from the internet. The second most common source was magazines (85.2%). Majority of the students (53.4%) had an idea of an invisible scar as a result of having a plastic surgery procedure. Only 22% thought to have no scar. Late Michael Jackson was at the top of the list of celebrities having a plastic surgery procedure (97.8%) followed by Nawaz Shariff (92.4%). CONCLUSION Despite the rapid growth of plastic surgery in the last two decades, a large portion of population remains unaware of the spatiality. It is essential to institute programs to educate healthcare consumers and providers about the plastic surgery. PMID:25489513

Views of college students on plastic surgery.

PubMed

Ahmad, Muhammad; Mohmand, Humayun; Ahmad, Nabila

2013-06-01

Various studies have been conducted in many countries to determine the perception/awareness about plastic surgery. The present study assessed the views of college students about plastic surgery. A questionnaire consisted of nine questions regarding the basic knowledge about plastic surgery was randomly distributed among college students. The students were given 20 minutes to fill out the forms. A total of 250 male and 250 female college students were randomly included in the study. The mean age of the male students was 21.1 years as compared to 20.7 years of female students. The top five conditions named were related to hair (89.8%) followed by face scars (88%). The most common procedure named by the students was liposuction (88.2%) followed by hair transplantation. 80.2% of the students opted not to be a plastic surgeon if given an opportunity to select the profession. 33.8% of the students had seen some kinds of plastic surgery operation. Only 5.6% of the students (3.4% male and 2.2% female) had seen some kinds of plastic surgery procedure. 68% of male students and 48% of female students wished to have a plastic surgery procedure sometime in their lives. Majority of the students (88%) got the information from the internet. The second most common source was magazines (85.2%). Majority of the students (53.4%) had an idea of an invisible scar as a result of having a plastic surgery procedure. Only 22% thought to have no scar. Late Michael Jackson was at the top of the list of celebrities having a plastic surgery procedure (97.8%) followed by Nawaz Shariff (92.4%). Despite the rapid growth of plastic surgery in the last two decades, a large portion of population remains unaware of the spatiality. It is essential to institute programs to educate healthcare consumers and providers about the plastic surgery.

Transferability of laparoscopic skills using the virtual reality simulator.

PubMed

Yang, Cui; Kalinitschenko, Uljana; Helmert, Jens R; Weitz, Juergen; Reissfelder, Christoph; Mees, Soeren Torge

2018-03-30

Skill transfer represents an important issue in surgical education, and is not well understood. The aim of this randomized study is to assess the transferability of surgical skills between two laparoscopic abdominal procedures using the virtual reality simulator in surgical novices. From September 2016 to July 2017, 44 surgical novices were randomized into two groups and underwent a proficiency-based basic training consisting of five selected simulated laparoscopic tasks. In group 1, participants performed an appendectomy training on the virtual reality simulator until they reached a defined proficiency. They moved on to the tutorial procedural tasks of laparoscopic cholecystectomy. Participants in group 2 started with the tutorial procedural tasks of laparoscopic cholecystectomy directly. Finishing the training, participants of both groups were required to perform a complete cholecystectomy on the simulator. Time, safety and economy parameters were analysed. Significant differences in the demographic characteristics and previous computer games experience between the two groups were not noted. Both groups took similar time to complete the proficiency-based basic training. Participants in group 1 needed significantly less movements (388.6 ± 98.6 vs. 446.4 ± 81.6; P < 0.05) as well as shorter path length (810.2 ± 159.5 vs. 945.5 ± 187.8 cm; P < 0.05) to complete the cholecystectomy compared to group 2. Time and safety parameters did not differ significantly between both groups. The data demonstrate a positive transfer of motor skills between laparoscopic appendectomy and cholecystectomy on the virtual reality simulator; however, the transfer of cognitive skills is limited. Separate training curricula seem to be necessary for each procedure for trainees to practise task-specific cognitive skills effectively. Mentoring could help trainees to get a deeper understanding of the procedures, thereby increasing the chance for the transfer of acquired skills.

Predicate Argument Structure Frames for Modeling Information in Operative Notes

PubMed Central

Wang, Yan; Pakhomov, Serguei; Melton, Genevieve B.

2015-01-01

The rich information about surgical procedures contained in operative notes is a valuable data source for improving the clinical evidence base and clinical research. In this study, we propose a set of Predicate Argument Structure (PAS) frames for surgical action verbs to assist in the creation of an information extraction (IE) system to automatically extract details about the techniques, equipment, and operative steps from operative notes. We created PropBank style PAS frames for the 30 top surgical action verbs based on examination of randomly selected sample sentences from 3,000 Laparoscopic Cholecystectomy notes. To assess completeness of the PAS frames to represent usage of same action verbs, we evaluated the PAS frames created on sample sentences from operative notes of 6 other gastrointestinal surgical procedures. Our results showed that the PAS frames created with one type of surgery can successfully denote the usage of the same verbs in operative notes of broader surgical categories. PMID:23920664

Scaling earthquake ground motions for performance-based assessment of buildings

USGS Publications Warehouse

Huang, Y.-N.; Whittaker, A.S.; Luco, N.; Hamburger, R.O.

2011-01-01

The impact of alternate ground-motion scaling procedures on the distribution of displacement responses in simplified structural systems is investigated. Recommendations are provided for selecting and scaling ground motions for performance-based assessment of buildings. Four scaling methods are studied, namely, (1)geometric-mean scaling of pairs of ground motions, (2)spectrum matching of ground motions, (3)first-mode-period scaling to a target spectral acceleration, and (4)scaling of ground motions per the distribution of spectral demands. Data were developed by nonlinear response-history analysis of a large family of nonlinear single degree-of-freedom (SDOF) oscillators that could represent fixed-base and base-isolated structures. The advantages and disadvantages of each scaling method are discussed. The relationship between spectral shape and a ground-motion randomness parameter, is presented. A scaling procedure that explicitly considers spectral shape is proposed. ?? 2011 American Society of Civil Engineers.

Scalable randomized benchmarking of non-Clifford gates

NASA Astrophysics Data System (ADS)

Cross, Andrew; Magesan, Easwar; Bishop, Lev; Smolin, John; Gambetta, Jay

Randomized benchmarking is a widely used experimental technique to characterize the average error of quantum operations. Benchmarking procedures that scale to enable characterization of n-qubit circuits rely on efficient procedures for manipulating those circuits and, as such, have been limited to subgroups of the Clifford group. However, universal quantum computers require additional, non-Clifford gates to approximate arbitrary unitary transformations. We define a scalable randomized benchmarking procedure over n-qubit unitary matrices that correspond to protected non-Clifford gates for a class of stabilizer codes. We present efficient methods for representing and composing group elements, sampling them uniformly, and synthesizing corresponding poly (n) -sized circuits. The procedure provides experimental access to two independent parameters that together characterize the average gate fidelity of a group element. We acknowledge support from ARO under Contract W911NF-14-1-0124.

A closer look at cross-validation for assessing the accuracy of gene regulatory networks and models.

PubMed

Tabe-Bordbar, Shayan; Emad, Amin; Zhao, Sihai Dave; Sinha, Saurabh

2018-04-26

Cross-validation (CV) is a technique to assess the generalizability of a model to unseen data. This technique relies on assumptions that may not be satisfied when studying genomics datasets. For example, random CV (RCV) assumes that a randomly selected set of samples, the test set, well represents unseen data. This assumption doesn't hold true where samples are obtained from different experimental conditions, and the goal is to learn regulatory relationships among the genes that generalize beyond the observed conditions. In this study, we investigated how the CV procedure affects the assessment of supervised learning methods used to learn gene regulatory networks (or in other applications). We compared the performance of a regression-based method for gene expression prediction estimated using RCV with that estimated using a clustering-based CV (CCV) procedure. Our analysis illustrates that RCV can produce over-optimistic estimates of the model's generalizability compared to CCV. Next, we defined the 'distinctness' of test set from training set and showed that this measure is predictive of performance of the regression method. Finally, we introduced a simulated annealing method to construct partitions with gradually increasing distinctness and showed that performance of different gene expression prediction methods can be better evaluated using this method.

Acellular dermal matrix graft with or without enamel matrix derivative for root coverage in smokers: a randomized clinical study.

PubMed

Alves, Luciana B; Costa, Priscila P; Scombatti de Souza, Sérgio Luís; de Moraes Grisi, Márcio F; Palioto, Daniela B; Taba, Mario; Novaes, Arthur B

2012-04-01

The aim of this randomized controlled clinical study was to compare the use of an acellular dermal matrix graft (ADMG) with or without the enamel matrix derivative (EMD) in smokers to evaluate which procedure would provide better root coverage. Nineteen smokers with bilateral Miller Class I or II gingival recessions ≥3 mm were selected. The test group was treated with an association of ADMG and EMD, and the control group with ADMG alone. Probing depth, relative clinical attachment level, gingival recession height, gingival recession width, keratinized tissue width and keratinized tissue thickness were evaluated before the surgeries and after 6 months. Wilcoxon test was used for the statistical analysis at significance level of 5%. No significant differences were found between groups in all parameters at baseline. The mean gain recession height between baseline and 6 months and the complete root coverage favored the test group (p = 0.042, p = 0.019 respectively). Smoking may negatively affect the results achieved through periodontal plastic procedures; however, the association of ADMG and EMD is beneficial in the root coverage of gingival recessions in smokers, 6 months after the surgery. © 2012 John Wiley & Sons A/S.

The impact of initialization procedures on unsupervised unmixing of hyperspectral imagery using the constrained positive matrix factorization

NASA Astrophysics Data System (ADS)

Masalmah, Yahya M.; Vélez-Reyes, Miguel

2007-04-01

The authors proposed in previous papers the use of the constrained Positive Matrix Factorization (cPMF) to perform unsupervised unmixing of hyperspectral imagery. Two iterative algorithms were proposed to compute the cPMF based on the Gauss-Seidel and penalty approaches to solve optimization problems. Results presented in previous papers have shown the potential of the proposed method to perform unsupervised unmixing in HYPERION and AVIRIS imagery. The performance of iterative methods is highly dependent on the initialization scheme. Good initialization schemes can improve convergence speed, whether or not a global minimum is found, and whether or not spectra with physical relevance are retrieved as endmembers. In this paper, different initializations using random selection, longest norm pixels, and standard endmembers selection routines are studied and compared using simulated and real data.

45 CFR 1217.4 - Selection procedure.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Selection procedure. 1217.4 Section 1217.4 Public... VISTA VOLUNTEER LEADER § 1217.4 Selection procedure. (a) Nomination. Candidates may be nominated in... Director's review. (b) Selection. VISTA volunteer leaders will be selected by the Regional Director (or his...

Embolization of the Gastroduodenal Artery Before Selective Internal Radiotherapy: A Prospectively Randomized Trial Comparing Standard Pushable Coils with Fibered Interlock Detachable Coils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dudeck, Oliver, E-mail: oliver.dudeck@med.ovgu.de; Bulla, Karsten; Wieners, Gero

2011-02-15

The purpose of this study was compare embolization of the gastroduodenal artery (GDA) using standard pushable coils with the Interlock detachable coil (IDC), a novel fibered mechanically detachable long microcoil, in patients scheduled for selective internal radiotherapy (SIRT). Fifty patients (31 male and 19 female; median age 66.6 {+-} 8.1 years) were prospectively randomized for embolization using either standard coils or IDCs. Procedure time, radiation dose, number of embolization devices, complications, and durability of vessel occlusion at follow-up angiography were recorded. The procedures differed significantly in time (14:32 {+-} 5:56 min for standard coils vs. 2:13 {+-} 1:04 min formore » IDCs; p < 0.001); radiation dose for coil deployment (2479 {+-} 1237 cGycm Superscript-Two for standard coils vs. 275 {+-} 268 cGycm Superscript-Two for IDCs; p < 0.001); and vessel occlusion (17:18 {+-} 6:39 min for standard coils vs. 11:19 {+-} 7:54 min for IDCs; p = 0.002). A mean of 6.2 {+-} 1.8 coils (n = 27) were used in the standard coil group, and 1.3 {+-} 0.9 coils (p < 0.0001) were used in the IDC group (n = 23) because additional pushable coils were required to achieve GDA occlusion in 4 patients. In 2 patients, the IDC could not be deployed through a Soft-VU catheter. One standard coil dislodged in the hepatic artery and was retrieved. Vessel reperfusion was noted in only 1 patient in the standard coil group. Controlled embolization of the GDA with fibered IDCs was achieved more rapidly than with pushable coils. However, vessel occlusion may not be obtained using a single device only, and the use of sharply angled guiding catheters hampered coil pushability.« less

The IBV Valve trial: a multicenter, randomized, double-blind trial of endobronchial therapy for severe emphysema.

PubMed

Wood, Douglas E; Nader, Daniel A; Springmeyer, Steven C; Elstad, Mark R; Coxson, Harvey O; Chan, Andrew; Rai, Navdeep S; Mularski, Richard A; Cooper, Christopher B; Wise, Robert A; Jones, Paul W; Mehta, Atul C; Gonzalez, Xavier; Sterman, Daniel H

2014-10-01

Lung volume reduction surgery improves quality of life, exercise capacity, and survival in selected patients but is accompanied by significant morbidity. Bronchoscopic approaches may provide similar benefits with less morbidity. In a randomized, sham procedure controlled, double-blind trial, 277 subjects were enrolled at 36 centers. Patients had emphysema, airflow obstruction, hyperinflation, and severe dyspnea. The primary effectiveness measure was a significant improvement in disease-related quality of life (St. George's Respiratory Questionnaire) and changes in lobar lung volumes. The primary safety measure was a comparison of serious adverse events. There were 6/121 (5.0%) responders in the treatment group at 6 months, significantly >1/134 (0.7%) in the control group [Bayesian credible intervals (BCI), 0.05%, 9.21%]. Lobar volume changes were significantly different with an average decrease in the treated lobes of -224 mL compared with -17 mL for the control group (BCI, -272, -143). The proportion of responders in St. George's Respiratory Questionnaire was not greater in the treatment group. There were significantly more subjects with a serious adverse event in the treatment group (n=20 or 14.1%) compared with the control group (n=5 or 3.7%) (BCI, 4.0, 17.1), but most were neither procedure nor device related. This trial had technical and statistical success but partial-bilateral endobronchial valve occlusion did not obtain clinically meaningful results. Safety results were acceptable and compare favorably to lung volume reduction surgery and other bronchial valve studies. Further studies need to focus on improved patient selection and a different treatment algorithm. ClinicalTrials.gov NCT00475007.

The structure, organisation and perioperative management of ambulatory surgery and anaesthesia in France: Methodology of the SFAR-OPERA study.

PubMed

Albaladejo, Pierre; Aubrun, Frédéric; Samama, Charles-Marc; Jouffroy, Laurent; Beaussier, Marc; Benhamou, Dan; Romegoux, Pauline; Skaare, Kristina; Bosson, Jean-Luc; Ecoffey, Claude

2017-10-01

The organization of health care establishments and perioperative care are essential for ensuring the quality of care and safety of patients undergoing outpatient surgery. In order to correctly inventory these organizations and practices, in 2013-2014, the French society of anaesthesia and intensive care organized an extensive practical survey in French ambulatory surgery units entitled the "OPERA" study (Organisation periopératoire de l'anesthésie en chirurgie ambulatoire). From among all of the ambulatory surgery centres listed by the Agences régionales de santé (Regional health agencies, France), 206 public and private centres were randomly selected. A structural (typology, organization) survey and a medical-practice survey (focusing on the management of postoperative pain, nausea and vomiting as well as the prevention of venous thromboembolism) were collected and managed by a prospective audit of practices occurring on two randomly selected days. The latter was further accompanied by an additional audit specifically focussing on ten representative procedures: (1) stomatology surgery (third molar removal); (2) knee arthroscopy; (3) surgery of the abdominal wall (including inguinal hernia); (4) perianal surgery; (5) varicose vein surgery; (6) digestive laparoscopy-cholecystectomy; (7) breast surgery (tumourectomy); (8) uterine surgery; (9) hallux valgus and (10) hand surgery (excluding carpal tunnel). Over the 2 days of observation, 7382 patients were included comprising 2174 patients who underwent one of the procedures from the above list. The analysis of these data will provide an overview of the organization of health establishments, the modalities thus supported and compliance with standards. Copyright © 2016 Société française d'anesthésie et de réanimation (Sfar). Published by Elsevier Masson SAS. All rights reserved.

CMOS gate array characterization procedures

NASA Astrophysics Data System (ADS)

Spratt, James P.

1993-09-01

Present procedures are inadequate for characterizing the radiation hardness of gate array product lines prior to personalization because the selection of circuits to be used, from among all those available in the manufacturer's circuit library, is usually uncontrolled. (Some circuits are fundamentally more radiation resistant than others.) In such cases, differences in hardness can result between different designs of the same logic function. Hardness also varies because many gate arrays feature large custom-designed megacells (e.g., microprocessors and random access memories-MicroP's and RAM's). As a result, different product lines cannot be compared equally. A characterization strategy is needed, along with standardized test vehicle(s), methodology, and conditions, so that users can make informed judgments on which gate arrays are best suited for their needs. The program described developed preferred procedures for the radiation characterization of gate arrays, including a gate array evaluation test vehicle, featuring a canary circuit, designed to define the speed versus hardness envelope of the gate array. A multiplier was chosen for this role, and a baseline multiplier architecture is suggested that could be incorporated into an existing standard evaluation circuit chip.

Evaluation of Factors Influencing Accuracy of Principal Procedure Coding Based on ICD-9-CM: An Iranian Study

PubMed Central

Farzandipour, Mehrdad; Sheikhtaheri, Abbas

2009-01-01

To evaluate the accuracy of procedural coding and the factors that influence it, 246 records were randomly selected from four teaching hospitals in Kashan, Iran. “Recodes” were assigned blindly and then compared to the original codes. Furthermore, the coders' professional behaviors were carefully observed during the coding process. Coding errors were classified as major or minor. The relations between coding accuracy and possible effective factors were analyzed by χ2 or Fisher exact tests as well as the odds ratio (OR) and the 95 percent confidence interval for the OR. The results showed that using a tabular index for rechecking codes reduces errors (83 percent vs. 72 percent accuracy). Further, more thorough documentation by the clinician positively affected coding accuracy, though this relation was not significant. Readability of records decreased errors overall (p = .003), including major ones (p = .012). Moreover, records with no abbreviations had fewer major errors (p = .021). In conclusion, not using abbreviations, ensuring more readable documentation, and paying more attention to available information increased coding accuracy and the quality of procedure databases. PMID:19471647

Introducing Statistical Inference to Biology Students through Bootstrapping and Randomization

ERIC Educational Resources Information Center

Lock, Robin H.; Lock, Patti Frazer

2008-01-01

Bootstrap methods and randomization tests are increasingly being used as alternatives to standard statistical procedures in biology. They also serve as an effective introduction to the key ideas of statistical inference in introductory courses for biology students. We discuss the use of such simulation based procedures in an integrated curriculum…

An Examination of Fluoxetine for the Treatment of Selective Mutism Using a Nonconcurrent Multiple-Baseline Single-Case Design Across 5 Cases.

PubMed

Barterian, Justin A; Sanchez, Joel M; Magen, Jed; Siroky, Allison K; Mash, Brittany L; Carlson, John S

2018-01-01

This study examined the utility of fluoxetine in the treatment of 5 children, aged 5 to 14 years, diagnosed with selective mutism who also demonstrated symptoms of social anxiety. A nonconcurrent, randomized, multiple-baseline, single-case design with a single-blind placebo-controlled procedure was used. Parents and the study psychiatrist completed multiple methods of assessment including Direct Behavior Ratings and questionnaires. Treatment outcomes were evaluated by calculating effect sizes for each participant as an individual and for the participants as a group. Information regarding adverse effects with an emphasis on behavioral disinhibition and ratings of parental acceptance of the intervention was gathered. All 5 children experienced improvement in social anxiety, responsive speech, and spontaneous speech with medium to large effect sizes; however, children still met criteria for selective mutism at the end of the study. Adverse events were minimal, with only 2 children experiencing brief occurrences of minor behavioral disinhibition. Parents found the treatment highly acceptable.

Pareto genealogies arising from a Poisson branching evolution model with selection.

PubMed

Huillet, Thierry E

2014-02-01

We study a class of coalescents derived from a sampling procedure out of N i.i.d. Pareto(α) random variables, normalized by their sum, including β-size-biasing on total length effects (β < α). Depending on the range of α we derive the large N limit coalescents structure, leading either to a discrete-time Poisson-Dirichlet (α, -β) Ξ-coalescent (α ε[0, 1)), or to a family of continuous-time Beta (2 - α, α - β)Λ-coalescents (α ε[1, 2)), or to the Kingman coalescent (α ≥ 2). We indicate that this class of coalescent processes (and their scaling limits) may be viewed as the genealogical processes of some forward in time evolving branching population models including selection effects. In such constant-size population models, the reproduction step, which is based on a fitness-dependent Poisson Point Process with scaling power-law(α) intensity, is coupled to a selection step consisting of sorting out the N fittest individuals issued from the reproduction step.

Cellular Spacing Selection During the Directional Solidification of Binary Alloys. A Numerical Approach

NASA Technical Reports Server (NTRS)

Catalina, Adrian V.; Sen, S.; Rose, M. Franklin (Technical Monitor)

2001-01-01

The evolution of cellular solid/liquid interfaces from an initially unstable planar front was studied by means of a two-dimensional computer simulation. The developed numerical model makes use of an interface tracking procedure and has the capability to describe the dynamics of the interface morphology based on local changes of the thermodynamic conditions. The fundamental physics of this formulation was validated against experimental microgravity results and the predictions of the analytical linear stability theory. The performed simulations revealed that in certain conditions, based on a competitive growth mechanism, an interface could become unstable to random perturbations of infinitesimal amplitude even at wavelengths smaller than the neutral wavelength, lambda(sub c), predicted by the linear stability theory. Furthermore, two main stages of spacing selection have been identified. In the first stage, at low perturbations amplitude, the selection mechanism is driven by the maximum growth rate of instabilities while in the second stage the selection is influenced by nonlinear phenomena caused by the interactions between the neighboring cells. Comparison of these predictions with other existing theories of pattern formation and experimental results will be discussed.

Zeta Sperm Selection Improves Pregnancy Rate and Alters Sex Ratio in Male Factor Infertility Patients: A Double-Blind, Randomized Clinical Trial

PubMed Central

Nasr Esfahani, Mohammad Hossein; Deemeh, Mohammad Reza; Tavalaee, Marziyeh; Sekhavati, Mohammad Hadi; Gourabi, Hamid

2016-01-01

Background Selection of sperm for intra-cytoplasmic sperm injection (ICSI) is usually considered as the ultimate technique to alleviate male-factor infertility. In routine ICSI, selection is based on morphology and viability which does not necessarily preclude the chance injection of DNA-damaged or apoptotic sperm into the oocyte. Sperm with high negative surface electrical charge, named “Zeta potential”, are mature and more likely to have intact chromatin. In addition, X-bearing spermatozoa carry more negative charge. Therefore, we aimed to compare the clinical outcomes of Zeta procedure with routine sperm selection in infertile men candidate for ICSI. Materials and Methods From a total of 203 ICSI cycles studied, 101 cycles were allocated to density gradient centrifugation (DGC)/Zeta group and the remaining 102 were included in the DGC group in this prospective study. Clinical outcomes were com- pared between the two groups. The ratios of Xand Y bearing sperm were assessed by fluorescence in situ hybridization (FISH) and quantitative polymerase chain reaction (qPCR) methods in 17 independent semen samples. Results In the present double-blind randomized clinical trial, a significant increase in top quality embryos and pregnancy rate were observed in DGC/Zeta group compared to DGC group. Moreover, sex ratio (XY/XX) at birth significantly was lower in the DGC/Zeta group compared to DGC group despite similar ratio of X/Y bearings sper- matozoa following Zeta selection. Conclusion Zeta method not only improves the percentage of top embryo quality and pregnancy outcome but also alters the sex ratio compared to the conventional DGC method, despite no significant change in the ratio of Xand Ybearing sperm population (Registration number: IRCT201108047223N1). PMID:27441060

The Effect of Sodium Hypochlorite and Chlorhexidine as Irrigant Solutions for Root Canal Disinfection: A Systematic Review of Clinical Trials.

PubMed

Gonçalves, Lucio Souza; Rodrigues, Renata Costa Val; Andrade Junior, Carlos Vieira; Soares, Renata G; Vettore, Mario Vianna

2016-04-01

This systematic review aimed to compare the effectiveness of sodium hypochlorite and chlorhexidine for root canal disinfection during root canal therapy. A literature search for clinical trials was made on the PubMed (MEDLINE), Web of Knowledge, SCOPUS, and Science Direct databases and in the reference lists of the identified articles up to January 2015. Quality assessment of the selected studies was performed according to the Consolidated Standards of Reporting Trials statement. One clinical trial and 4 randomized clinical trials were selected from the 172 articles initially identified. There was heterogeneity in the laboratory methods used to assess the root canal disinfection as well as in the concentrations of the irrigants used. Therefore, meta-analysis was not performed. Two studies reported effective and similar reductions in bacterial levels for both irrigants. Sodium hypochlorite was more effective than chlorhexidine in reducing microorganisms in 1 study, and another reported opposite findings. Both root irrigants were ineffective in eliminating endotoxins from necrotic pulp root canals in 1 study. Trial design and information regarding randomization procedures were not clearly described in the clinical trials. No study compared laboratory results with clinical outcomes. The available evidence on this topic is scarce, and the findings of studies were not consistent. Additional randomized clinical trials using clinical outcomes to compare the use of sodium hypochlorite and chlorhexidine during root canal therapy are needed. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

COMPARISON OF RANDOM AND SYSTEMATIC SITE SELECTION FOR ASSESSING ATTAINMENT OF AQUATIC LIFE USES IN SEGMENTS OF THE OHIO RIVER

EPA Science Inventory

This report is a description of field work and data analysis results comparing a design comparable to systematic site selection with one based on random selection of sites. The report is expected to validate the use of random site selection in the bioassessment program for the O...

Low pH irrigation fluids have positive effect on intra-articular chondral healing.

PubMed

Ulku, Tekin Kerem; Kocaoglu, Baris; Gereli, Arel; Uslu, Serap; Nalbantoglu, Ufuk

2017-12-02

The aim of this study was to evaluate the effect of Ringer's lactate (RL) solutions with different pH values on early histologic healing in a microfracture model in vivo. The null hypothesis of the presented study is that irrigation fluids with lower pH (6.4) have negative effects on fibrous cartilage healing. Eighteen Wistar albino rats were randomly divided into three groups. Anterior midline incision was performed. Microfracture procedure was performed with a 1.2 mm k-wire at the lateral femoral condyle of each knee. the skin was sutured and joints were irrigated for 30 min with low pH (6.4) RL in Group 1, high pH (7.6) RL in Group 2 and no irrigation in Group 3. Three rats from each group were randomly selected and killed on the 3rd and 7th day. On the 3rd day, the healed chondral area was examined. On the 3rd and 7th day, the chondral depth and morphology were evaluated. On the 7th day, bone cellularity was assessed with osteoblast; osteoclast number and bone quality were evaluated with trabecular area and the number of trabeculae. Chondral healing area on the 3rd day was significantly higher in Group 1 compared to other groups. Chondral morphology was also qualitatively superior in Group 1 compared to other groups on the 3rd and 7th day. There were no differences in chondral depths between the groups on the 3rd day; however, increased chondral depths were observed in Group 1 on the 7th day. There were statistically significant increases in trabecular area and the number of trabeculae, as well as the number of osteoblasts and osteoclasts in Group 1 on the 7th day. The presented study revealed that low pH irrigation fluids have positive effects on the healing characteristics of intra-articular fibrous cartilage after microfracture procedure in vivo. In light of this study, we can assume that lower pH solutions could be safely used during microfracture procedures and it can also facilitate intra-articular fibrous cartilage formation and cartilage healing. Selection of irrigation solution is also important for intra-articular fibrous cartilage healing after microfracture procedure in vivo.

The effect of yoga in stress reduction for dental students performing their first periodontal surgery: A randomized controlled study

PubMed Central

Shankarapillai, Rajesh; Nair, Manju Anathakrishnan; George, Roy

2012-01-01

Context: The dental students experience a lot of stress, which increase when they perform their first surgical procedure. Yoga as an anxiolytic tool in anxiety reduction has been practiced over centuries in India. Aim: To assess the efficacy of yoga in reducing the state trait anxiety of dental students before their first periodontal surgery performance. Settings and Design: A randomized controlled study using a two-way split plot design (pre-post-test) was conducted in the department of periodontics, Pacific Dental College, Udaipur, India. Materials and Methods: One hundred clinical dental students who were ready to perform their first periodontal surgery were selected. Students were randomly assigned to two groups and were given a 60-min session on stress reduction. Group A, yogic intervention group, were instructed to do yoga and their performances were monitored for a period of one week and Group B, control group, were given a lecture on stress reduction without any yoga instructions. The investigator who was unaware of the groups had taken the state trait anxiety score of the students three times a) before assigning them to each group, b) prior to the surgical procedure and c) immediately after the performance of surgery. Statistical Analysis Used: Analyses of variance (ANOVA) by SPSS V.16. Results: The statistical results showed a significant reduction in the VAS and state trait anxiety of Group A compared to Group B (ANOVA; P<0.001). Conclusions: This study concludes that Yogic breathing has a significant effect on the reduction of state trait anxiety level of dental students. PMID:22346066

Matched-pair analyses of resting and dynamic morphology between Monarc and TVT-O procedures by ultrasound.

PubMed

Yang, Jenn-Ming; Yang, Shwu-Huey; Huang, Wen-Chen; Tzeng, Chii-Ruey

2013-07-01

To determine morphologic differences between Monarc and TVT-O procedures in axial and coronal planes by three- and four-dimensional (3D and 4D) ultrasound. Retrospective chart audits and ultrasound analyses were conducted on 128 women who had undergone either Monarc or TVT-O procedures for urodynamic stress incontinence. Thirty matched pairs of the two successful procedures were randomly selected and compared. Matched variables were age, parity, body mass index, cesarean status, menopausal status, and primary surgeries. Six-month postoperative 3D and 4D ultrasound results obtained at rest, on straining, and during coughing in these 60 women were analyzed. Assessed ultrasound parameters included the axial tape urethral distance (aTUD), axial central urethral echolucent area (aUCEA), axial tape angle (aTA), and coronal tape angle (cTA), all of which were measured at three equidistant points along the tapes. Paired t-tests were used to compare differences in ultrasound parameters between women after the two procedures and a P value <0.004 was considered significant after Bonferroni correction. At rest, women subjected to Monarc procedures had a significantly wider aTA at one-fourth of the tape and a wider cTA at one-, two-, and three-fourths of the tape than did those subjected to TVT-O procedures. There were no significant differences in other resting ultrasound parameters between these two procedures. Additionally, after both procedures women had comparable straining and coughing ultrasound manifestations as well as respective dynamic changes. Despite flatter resting tape angulations in women following Monarc procedures, both Monarc and TVT-O tapes had equivalent dynamic patterns and changes assessed by 4D ultrasound. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

An affine projection algorithm using grouping selection of input vectors

NASA Astrophysics Data System (ADS)

Shin, JaeWook; Kong, NamWoong; Park, PooGyeon

2011-10-01

This paper present an affine projection algorithm (APA) using grouping selection of input vectors. To improve the performance of conventional APA, the proposed algorithm adjusts the number of the input vectors using two procedures: grouping procedure and selection procedure. In grouping procedure, the some input vectors that have overlapping information for update is grouped using normalized inner product. Then, few input vectors that have enough information for for coefficient update is selected using steady-state mean square error (MSE) in selection procedure. Finally, the filter coefficients update using selected input vectors. The experimental results show that the proposed algorithm has small steady-state estimation errors comparing with the existing algorithms.

Consultant selection guidebook : procedures for selecting consultants for FHWA federal-aid projects and state funded projects. [Rev. 2002

DOT National Transportation Integrated Search

2002-01-01

This Guidebook provides an overview of procedures for consultant selection. The local agencies that intend to request federal and state funds for reimbursement of consultant services should follow specific selection and contracting procedures. These ...

Determination of Pesticides Residues in Cucumbers Grown in Greenhouse and the Effect of Some Procedures on Their Residues.

PubMed

Leili, Mostafa; Pirmoghani, Amin; Samadi, Mohammad Taghi; Shokoohi, Reza; Roshanaei, Ghodratollah; Poormohammadi, Ali

2016-11-01

The objective of this study was to determine the residual concentrations of ethion and imidacloprid in cucumbers grown in greenhouse. The effect of some simple processing procedures on both ethion and imidacloprid residues were also studied. Ten active greenhouses that produce cucumber were randomly selected. Ethion and imidacloprid as the most widely used pesticides were measured in cucumber samples of studied greenhouses. Moreover, the effect of storing, washing, and peeling as simple processing procedures on both ethion and imidacloprid residues were investigated. One hour after pesticide application; the maximum residue levels (MRLs) of ethion and imidacloprid were higher than that of Codex standard level. One day after pesticide application, the levels of pesticides were decreased about 35 and 31% for ethion and imidacloprid, respectively, which still were higher than the MRL. Washing procedure led to about 51 and 42.5% loss in ethion and imidacloprid residues, respectively. Peeling procedure also led to highest loss of 93.4 and 63.7% in ethion and imidacloprid residues, respectively. The recovery for both target analytes was in the range between 88 and 102%. The residue values in collected samples one hour after pesticides application were higher than standard value. The storing, washing, and peeling procedures lead to the decrease of pesticide residues in greenhouse cucumbers. Among them, the peeling procedure has the greatest impact on residual reduction. Therefore, these procedures can be used as simple and effective processing techniques for reducing and removing pesticides from greenhouse products before their consumption.

A Randomized Study of a Method for Optimizing Adolescent Assent to Biomedical Research

PubMed Central

Annett, Robert D.; Brody, Janet L.; Scherer, David G.; Turner, Charles W.; Dalen, Jeanne; Raissy, Hengameh

2018-01-01

Purpose Voluntary consent/assent with adolescents invited to participate in research raises challenging problems. No studies to date have attempted to manipulate autonomy in relation to assent/consent processes. This study evaluated the effects of an autonomy-enhanced individualized assent/consent procedure embedded within a randomized pediatric asthma clinical trial. Methods Families were randomly assigned to remain together or separated during a consent/assent process, the latter we characterize as an autonomy-enhanced assent/consent procedure. We hypothesized that separating adolescents from their parents would improve adolescent assent by increasing knowledge and appreciation of the clinical trial and willingness to participate. Results 64 adolescent-parent dyads completed procedures. The together versus separate randomization made no difference in adolescent or parent willingness to participate. However, significant differences were found in both parent and adolescent knowledge of the asthma clinical trial based on the assent/consent procedure and adolescent age. The separate assent/consent procedure improved knowledge of study risks and benefits for older adolescents and their parents but not for the younger youth or their parents. Regardless of the assent/consent process, younger adolescents had lower comprehension of information associated with the study medication and research risks and benefits, but not study procedures or their research rights and privileges. Conclusions The use of an autonomy-enhanced assent/consent procedure for adolescents may improve their and their parent’s informed assent/consent without impacting research participation decisions. Traditional assent/consent procedures may result in a “diffusion of responsibility” effect between parents and older adolescents, specifically in attending to key information associated with study risks and benefits. PMID:28949898

Improving the Spatial Prediction of Soil Organic Carbon Stocks in a Complex Tropical Mountain Landscape by Methodological Specifications in Machine Learning Approaches

PubMed Central

Schmidt, Johannes; Glaser, Bruno

2016-01-01

Tropical forests are significant carbon sinks and their soils’ carbon storage potential is immense. However, little is known about the soil organic carbon (SOC) stocks of tropical mountain areas whose complex soil-landscape and difficult accessibility pose a challenge to spatial analysis. The choice of methodology for spatial prediction is of high importance to improve the expected poor model results in case of low predictor-response correlations. Four aspects were considered to improve model performance in predicting SOC stocks of the organic layer of a tropical mountain forest landscape: Different spatial predictor settings, predictor selection strategies, various machine learning algorithms and model tuning. Five machine learning algorithms: random forests, artificial neural networks, multivariate adaptive regression splines, boosted regression trees and support vector machines were trained and tuned to predict SOC stocks from predictors derived from a digital elevation model and satellite image. Topographical predictors were calculated with a GIS search radius of 45 to 615 m. Finally, three predictor selection strategies were applied to the total set of 236 predictors. All machine learning algorithms—including the model tuning and predictor selection—were compared via five repetitions of a tenfold cross-validation. The boosted regression tree algorithm resulted in the overall best model. SOC stocks ranged between 0.2 to 17.7 kg m-2, displaying a huge variability with diffuse insolation and curvatures of different scale guiding the spatial pattern. Predictor selection and model tuning improved the models’ predictive performance in all five machine learning algorithms. The rather low number of selected predictors favours forward compared to backward selection procedures. Choosing predictors due to their indiviual performance was vanquished by the two procedures which accounted for predictor interaction. PMID:27128736

48 CFR 570.305 - Two-phase design-build selection procedures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 4 2012-10-01 2012-10-01 false Two-phase design-build...-phase design-build selection procedures. (a) These procedures apply to acquisitions of leasehold interests if the contracting officer uses the two-phase design-build selection procedures authorized by 570...

48 CFR 570.305 - Two-phase design-build selection procedures.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 4 2014-10-01 2014-10-01 false Two-phase design-build...-phase design-build selection procedures. (a) These procedures apply to acquisitions of leasehold interests if the contracting officer uses the two-phase design-build selection procedures authorized by 570...

48 CFR 570.305 - Two-phase design-build selection procedures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 4 2013-10-01 2013-10-01 false Two-phase design-build...-phase design-build selection procedures. (a) These procedures apply to acquisitions of leasehold interests if the contracting officer uses the two-phase design-build selection procedures authorized by 570...

48 CFR 570.305 - Two-phase design-build selection procedures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Two-phase design-build...-phase design-build selection procedures. (a) These procedures apply to acquisitions of leasehold interests if the contracting officer uses the two-phase design-build selection procedures authorized by 570...

Randomizing Roaches: Exploring the "Bugs" of Randomization in Experimental Design

ERIC Educational Resources Information Center

Wagler, Amy; Wagler, Ron

2014-01-01

Understanding the roles of random selection and random assignment in experimental design is a central learning objective in most introductory statistics courses. This article describes an activity, appropriate for a high school or introductory statistics course, designed to teach the concepts, values and pitfalls of random selection and assignment…

Analgesic effect of intraperitoneal local anesthetic in surgery: an overview of systematic reviews.

PubMed

Hamill, James K; Rahiri, Jamie-Lee; Hill, Andrew G

2017-05-15

Intraperitoneal local anesthetic (IPLA) reduces postoperative pain as shown by previous systematic reviews. The purpose of this review was to compare the efficacy of IPLA between different types of procedure and to formulate GRADE recommendations for the use of IPLA. A systematic search for systematic reviews of the effect of IPLA, versus no IPLA or placebo, on pain after any surgical procedure. Databases included in the study were MEDLINE, EMBASE, CDSR, and DARE. Two reviewers independently undertook searches, selected studies, extracted data, and assessed the risk of bias. Meta-analysis was by random effects. Recommendation was by GRADE. The main outcome measure was self-reported early postoperative pain scores. Searches uncovered nine systematic reviews. This study included randomized trials numbered 76, representing 4000 participants, 2022 in IPLA and 1978 in control groups. Six reviews scored at low risk of bias and three at high risk. Meta-analysis demonstrated that IPLA reduced the mean pain score (0-10 scale) by 0.95 point (95% confidence interval: 0.73-1.17). Excluding laparoscopic cholecystectomy, the effect size increased to 1.52 (95% confidence interval: 1.15-1.88). Heterogeneity was high overall at I 2  = 91.7% but on excluding laparoscopic cholecystectomy trials reduced to I 2  = 31.3%. IPLA could be considered a viable option for early postoperative analgesia in certain laparoscopic operations. Further research on the effect of IPLA on procedures other than laparoscopic cholecystectomy would help clarify its place in a postoperative analgesia protocol. Copyright © 2017 Elsevier Inc. All rights reserved.

Intraoperative determination of the extent of corpus callosotomy for epilepsy: two simple techniques.

PubMed

Awad, I A; Wyllie, E; Luders, H; Ahl, J

1990-01-01

There is increasing interest in staged corpus callosotomy for intractable generalized epilepsy. At the first procedure, a portion (usually the anterior two-thirds) of the corpus callosum is sectioned. If seizures persist, completion of callosotomy or alternative treatment approaches can be considered. It is obviously important to ascertain that the desired extent of callosotomy was in fact accomplished at the time of initial operation. Our experience and the published literature indicate that the surgeon's impression at operation can be erroneous. We describe a technique of determining extent of corpus callosotomy during the procedure. The magnetic resonance imaging (MRI) scan in the midsagittal plane is used to select the desired extent of callosotomy. That point on the corpus callosum is characterized using simple planar geometry in relation to three anatomic landmarks in that same plane: the glabella, the inion, and the bregma (midline intersection of the coronal suture). The same point along the corpus callosum can then be located on a lateral skull x-ray using these same three anatomic landmarks. At surgery, an intraoperative lateral skull x-ray is obtained with a marking clip, thereby verifying the actual extent of callosotomy. We have verified the reliability of this scheme in 5 callosotomy procedures and have used this technique for intraoperative localization of midline and parasagittal targets in another 7 cases (3 tumors, 2 aneurysms, and 2 placements of interhemispheric subdural grids). In addition, we reviewed corpus callosum topography on 25 randomly selected MRI scans.(ABSTRACT TRUNCATED AT 250 WORDS)

Indirect vs direct bonding of mandibular fixed retainers in orthodontic patients: a single-center randomized controlled trial comparing placement time and failure over a 6-month period.

PubMed

Bovali, Efstathia; Kiliaridis, Stavros; Cornelis, Marie A

2014-12-01

The objective of this 2-arm parallel single-center trial was to compare placement time and numbers of failures of mandibular lingual retainers bonded with an indirect procedure vs a direct bonding procedure. Sixty-four consecutive patients at the postgraduate orthodontic clinic of the University of Geneva in Switzerland scheduled for debonding and mandibular fixed retainer placement were randomly allocated to either an indirect bonding procedure or a traditional direct bonding procedure. Eligibility criteria were the presence of the 4 mandibular incisors and the 2 mandibular canines, and no active caries, restorations, fractures, or periodontal disease of these teeth. The patients were randomized in blocks of 4; the randomization sequence was generated using an online randomization service (www.randomization.com). Allocation concealment was secured by contacting the sequence generator for treatment assignment; blinding was possible for outcome assessment only. Bonding time was measured for each procedure. Unpaired t tests were used to assess differences in time. Patients were recalled at 1, 2, 4, and 6 months after bonding. Mandibular fixed retainers having at least 1 composite pad debonded were considered as failures. The log-rank test was used to compare the Kaplan-Meier survival curves of both procedures. A test of proportion was applied to compare the failures at 6 months between the treatment groups. Sixty-four patients were randomized in a 1:1 ratio. One patient dropped out at baseline after the bonding procedure, and 3 patients did not attend the recalls at 4 and 6 months. Bonding time was significantly shorter for the indirect procedure (321 ± 31 seconds, mean ± SD) than for the direct procedure (401 ± 40 seconds) (per protocol analysis of 63 patients: mean difference = 80 seconds; 95% CI = 62.4-98.1; P <0.001). The 6-month numbers of failures were 10 of 31 (32%) with the indirect technique and 7 of 29 (24%) with the direct technique (log rank: P = 0.35; test of proportions: risk difference = 0.08; 95% CI = -0.15 to 0.31; P = 0.49). No serious harm was observed except for plaque accumulation. Indirect bonding was statistically significantly faster than direct bonding, with both techniques showing similar risks of failure. This trial was not registered. The protocol was not published before trial commencement. No funding or conflict of interest to be declared. Copyright © 2014 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

The study of combining Latin Hypercube Sampling method and LU decomposition method (LULHS method) for constructing spatial random field

NASA Astrophysics Data System (ADS)

WANG, P. T.

2015-12-01

Groundwater modeling requires to assign hydrogeological properties to every numerical grid. Due to the lack of detailed information and the inherent spatial heterogeneity, geological properties can be treated as random variables. Hydrogeological property is assumed to be a multivariate distribution with spatial correlations. By sampling random numbers from a given statistical distribution and assigning a value to each grid, a random field for modeling can be completed. Therefore, statistics sampling plays an important role in the efficiency of modeling procedure. Latin Hypercube Sampling (LHS) is a stratified random sampling procedure that provides an efficient way to sample variables from their multivariate distributions. This study combines the the stratified random procedure from LHS and the simulation by using LU decomposition to form LULHS. Both conditional and unconditional simulations of LULHS were develpoed. The simulation efficiency and spatial correlation of LULHS are compared to the other three different simulation methods. The results show that for the conditional simulation and unconditional simulation, LULHS method is more efficient in terms of computational effort. Less realizations are required to achieve the required statistical accuracy and spatial correlation.

Coordination and Management of Multisite Complementary and Alternative Medicine (CAM) Therapies: Experience from a Multisite Reflexology Intervention Trial

PubMed Central

Rahbar, Mohammad H.; Wyatt, Gwen; Sikorskii, Alla; Victorson, David; Ardjomand-Hessabi, Manouchehr

2011-01-01

Background Multisite randomized clinical trials allow for increased research collaboration among investigators and expedite data collection efforts. As a result, government funding agencies typically look favorably upon this approach. As the field of complementary and alternative medicine (CAM) continues to evolve, so do increased calls for the use of more rigorous study design and trial methodologies, which can present challenges for investigators. Purpose To describe the processes involved in the coordination and management of a multisite randomized clinical trial of a CAM intervention. Methods Key aspects related to the coordination and management of a multisite CAM randomized clinical trial are presented, including organizational and site selection considerations, recruitment concerns and issues related to data collection and randomization to treatment groups. Management and monitoring of data, as well as quality assurance procedures are described. Finally, a real world perspective is shared from a recently conducted multisite randomized clinical trial of reflexology for women diagnosed with advanced breast cancer. Results The use of multiple sites in the conduct of CAM-based randomized clinical trials can provide an efficient, collaborative and robust approach to study coordination and data collection that maximizes efficiency and ensures the quality of results. Conclusions Multisite randomized clinical trial designs can offer the field of CAM research a more standardized and efficient approach to examine the effectiveness of novel therapies and treatments. Special attention must be given to intervention fidelity, consistent data collection and ensuring data quality. Assessment and reporting of quantitative indicators of data quality should be required. PMID:21664296

[Pay attention to the complexity of cataract surgery of no vitreous eyes].

PubMed

Bao, Y Z

2017-04-11

With wide-spread performance of pars plana vitrectomy, cataract surgeries with no vitreous are getting more and more. This kind of surgery has great difference between individuals and it lacks randomized large sample clinical trial. Surgical strategy decision was basically relied on the surgeon's personal experience. We should fully aware the individual and common characteristics of no vitreous cataract surgery. Surgical time should be carefully decided. Complete ocular examination, evaluation, design of cataract surgical procedure and appropriate intra-ocular lens selection are needed. We must pay highly attention on the cataract surgery of no vitreous eyes. (Chin J Ophthalmol, 2017, 53: 241-243) .

Verifying the buildingEXODUS through an emergency response procedure (ERP) exercise at an underground intervention shaft

NASA Astrophysics Data System (ADS)

Tajedi, Noor Aqilah A.; Sukor, Nur Sabahiah A.; Ismail, Mohd Ashraf M.; Shamsudin, Shahrul A.

2017-10-01

An Emergency Response Plan (ERP) is an essential safety procedure that needs to be taken into account for railway operations, especially for underground railway networks. Several parameters need to be taken into consideration in planning an ERP such as the design of tunnels and intervention shafts, and operation procedures for underground transportation systems. Therefore, the purpose of this paper is to observe and analyse the Emergency Response Procedure (ERP) exercise for the underground train network at the LRT Kelana Jaya Line. The exercise was conducted at one of the underground intervention shaft exits, where the height of the staircase from the bottom floor to the upper floor was 24.59 metres. Four cameras were located at selected levels of the shaft, and 71 participants were assigned for the evacuation exercise. The participants were tagged with a number at the front and back of their safety vests. Ten respondents were randomly selected to give details of their height and weight and, at the same time, they had to self-record the time taken for them to evacuate from the bottom to the top of the shaft. The video footages that were taken during the ERP were analysed, and the data were used for the verification process on the buildingEXODUS simulation software. It was found that the results of the ERP experiment were significantly similar to the simulation results, thereby successfully verifying the simulation. This verification process was important to ensure that the results of the simulation were in accordance with the real situation. Therefore, a further evacuation analysis made use of the results from this verification.

Application of random effects to the study of resource selection by animals

USGS Publications Warehouse

Gillies, C.S.; Hebblewhite, M.; Nielsen, S.E.; Krawchuk, M.A.; Aldridge, Cameron L.; Frair, J.L.; Saher, D.J.; Stevens, C.E.; Jerde, C.L.

2006-01-01

1. Resource selection estimated by logistic regression is used increasingly in studies to identify critical resources for animal populations and to predict species occurrence.2. Most frequently, individual animals are monitored and pooled to estimate population-level effects without regard to group or individual-level variation. Pooling assumes that both observations and their errors are independent, and resource selection is constant given individual variation in resource availability.3. Although researchers have identified ways to minimize autocorrelation, variation between individuals caused by differences in selection or available resources, including functional responses in resource selection, have not been well addressed.4. Here we review random-effects models and their application to resource selection modelling to overcome these common limitations. We present a simple case study of an analysis of resource selection by grizzly bears in the foothills of the Canadian Rocky Mountains with and without random effects.5. Both categorical and continuous variables in the grizzly bear model differed in interpretation, both in statistical significance and coefficient sign, depending on how a random effect was included. We used a simulation approach to clarify the application of random effects under three common situations for telemetry studies: (a) discrepancies in sample sizes among individuals; (b) differences among individuals in selection where availability is constant; and (c) differences in availability with and without a functional response in resource selection.6. We found that random intercepts accounted for unbalanced sample designs, and models with random intercepts and coefficients improved model fit given the variation in selection among individuals and functional responses in selection. Our empirical example and simulations demonstrate how including random effects in resource selection models can aid interpretation and address difficult assumptions limiting their generality. This approach will allow researchers to appropriately estimate marginal (population) and conditional (individual) responses, and account for complex grouping, unbalanced sample designs and autocorrelation.

Application of random effects to the study of resource selection by animals.

PubMed

Gillies, Cameron S; Hebblewhite, Mark; Nielsen, Scott E; Krawchuk, Meg A; Aldridge, Cameron L; Frair, Jacqueline L; Saher, D Joanne; Stevens, Cameron E; Jerde, Christopher L

2006-07-01

1. Resource selection estimated by logistic regression is used increasingly in studies to identify critical resources for animal populations and to predict species occurrence. 2. Most frequently, individual animals are monitored and pooled to estimate population-level effects without regard to group or individual-level variation. Pooling assumes that both observations and their errors are independent, and resource selection is constant given individual variation in resource availability. 3. Although researchers have identified ways to minimize autocorrelation, variation between individuals caused by differences in selection or available resources, including functional responses in resource selection, have not been well addressed. 4. Here we review random-effects models and their application to resource selection modelling to overcome these common limitations. We present a simple case study of an analysis of resource selection by grizzly bears in the foothills of the Canadian Rocky Mountains with and without random effects. 5. Both categorical and continuous variables in the grizzly bear model differed in interpretation, both in statistical significance and coefficient sign, depending on how a random effect was included. We used a simulation approach to clarify the application of random effects under three common situations for telemetry studies: (a) discrepancies in sample sizes among individuals; (b) differences among individuals in selection where availability is constant; and (c) differences in availability with and without a functional response in resource selection. 6. We found that random intercepts accounted for unbalanced sample designs, and models with random intercepts and coefficients improved model fit given the variation in selection among individuals and functional responses in selection. Our empirical example and simulations demonstrate how including random effects in resource selection models can aid interpretation and address difficult assumptions limiting their generality. This approach will allow researchers to appropriately estimate marginal (population) and conditional (individual) responses, and account for complex grouping, unbalanced sample designs and autocorrelation.

Incidence of tuberculosis among school-going adolescents in South India.

PubMed

Uppada, Dharma Rao; Selvam, Sumithra; Jesuraj, Nelson; Lau, Esther L; Doherty, T Mark; Grewal, Harleen M S; Vaz, Mario; Lindtjørn, Bernt

2016-07-26

Tuberculosis (TB) incidence data in vaccine target populations, particularly adolescents, are important for designing and powering vaccine clinical trials. Little is known about the incidence of tuberculosis among adolescents in India. The objective of current study is to estimate the incidence of pulmonary tuberculosis (PTB) disease among adolescents attending school in South India using two different surveillance methods (active and passive) and to compare the incidence between the two groups. The study was a prospective cohort study with a 2-year follow-up period. The study was conducted in Palamaner, Chittoor District of Andhra Pradesh, South India from February 2007 to July 2010. A random sampling procedure was used to select a subset of schools to enable approximately 8000 subjects to be available for randomization in the study. A stratified randomization procedure was used to assign the selected schools to either active or passive surveillance. Participants who met the criteria for being exposed to TB were referred to the diagnostic ward for pulmonary tuberculosis confirmation. A total number of 3441 males and 3202 females between the ages 11 and less than 18 years were enrolled into the study. Of the 3102 participants in the active surveillance group, four subjects were diagnosed with definite tuberculosis, four subjects with probable tuberculosis, and 71 subjects had non-tuberculous Mycobacteria (NTM) isolated from their sputum. Of the 3541 participants in the passive surveillance group, four subjects were diagnosed with definite tuberculosis, two subjects with probable tuberculosis, and 48 subjects had non-tuberculosis Mycobacteria isolated from their sputum. The incidence of definite + probable TB was 147.60 / 100,000 person years in the active surveillance group and 87 / 100,000 person years in the passive surveillance group. The incidence of pulmonary tuberculosis among adolescents in our study is lower than similar studies conducted in South Africa and Eastern Uganda - countries with a higher incidence of tuberculosis and human immunodeficiency virus (HIV) than India. The study data will inform sample design for vaccine efficacy trials among adolescents in India.

The Fisher-Markov selector: fast selecting maximally separable feature subset for multiclass classification with applications to high-dimensional data.

PubMed

Cheng, Qiang; Zhou, Hongbo; Cheng, Jie

2011-06-01

Selecting features for multiclass classification is a critically important task for pattern recognition and machine learning applications. Especially challenging is selecting an optimal subset of features from high-dimensional data, which typically have many more variables than observations and contain significant noise, missing components, or outliers. Existing methods either cannot handle high-dimensional data efficiently or scalably, or can only obtain local optimum instead of global optimum. Toward the selection of the globally optimal subset of features efficiently, we introduce a new selector--which we call the Fisher-Markov selector--to identify those features that are the most useful in describing essential differences among the possible groups. In particular, in this paper we present a way to represent essential discriminating characteristics together with the sparsity as an optimization objective. With properly identified measures for the sparseness and discriminativeness in possibly high-dimensional settings, we take a systematic approach for optimizing the measures to choose the best feature subset. We use Markov random field optimization techniques to solve the formulated objective functions for simultaneous feature selection. Our results are noncombinatorial, and they can achieve the exact global optimum of the objective function for some special kernels. The method is fast; in particular, it can be linear in the number of features and quadratic in the number of observations. We apply our procedure to a variety of real-world data, including mid--dimensional optical handwritten digit data set and high-dimensional microarray gene expression data sets. The effectiveness of our method is confirmed by experimental results. In pattern recognition and from a model selection viewpoint, our procedure says that it is possible to select the most discriminating subset of variables by solving a very simple unconstrained objective function which in fact can be obtained with an explicit expression.

Primer-Free Aptamer Selection Using A Random DNA Library

PubMed Central

Pan, Weihua; Xin, Ping; Patrick, Susan; Dean, Stacey; Keating, Christine; Clawson, Gary

2010-01-01

Aptamers are highly structured oligonucleotides (DNA or RNA) that can bind to targets with affinities comparable to antibodies 1. They are identified through an in vitro selection process called Systematic Evolution of Ligands by EXponential enrichment (SELEX) to recognize a wide variety of targets, from small molecules to proteins and other macromolecules 2-4. Aptamers have properties that are well suited for in vivo diagnostic and/or therapeutic applications: Besides good specificity and affinity, they are easily synthesized, survive more rigorous processing conditions, they are poorly immunogenic, and their relatively small size can result in facile penetration of tissues. Aptamers that are identified through the standard SELEX process usually comprise ~80 nucleotides (nt), since they are typically selected from nucleic acid libraries with ~40 nt long randomized regions plus fixed primer sites of ~20 nt on each side. The fixed primer sequences thus can comprise nearly ~50% of the library sequences, and therefore may positively or negatively compromise identification of aptamers in the selection process 3, although bioinformatics approaches suggest that the fixed sequences do not contribute significantly to aptamer structure after selection 5. To address these potential problems, primer sequences have been blocked by complementary oligonucleotides or switched to different sequences midway during the rounds of SELEX 6, or they have been trimmed to 6-9 nt 7, 8. Wen and Gray 9 designed a primer-free genomic SELEX method, in which the primer sequences were completely removed from the library before selection and were then regenerated to allow amplification of the selected genomic fragments. However, to employ the technique, a unique genomic library has to be constructed, which possesses limited diversity, and regeneration after rounds of selection relies on a linear reamplification step. Alternatively, efforts to circumvent problems caused by fixed primer sequences using high efficiency partitioning are met with problems regarding PCR amplification 10. We have developed a primer-free (PF) selection method that significantly simplifies SELEX procedures and effectively eliminates primer-interference problems 11, 12. The protocols work in a straightforward manner. The central random region of the library is purified without extraneous flanking sequences and is bound to a suitable target (for example to a purified protein or complex mixtures such as cell lines). Then the bound sequences are obtained, reunited with flanking sequences, and re-amplified to generate selected sub-libraries. As an example, here we selected aptamers to S100B, a protein marker for melanoma. Binding assays showed Kd s in the 10-7 - 10-8 M range after a few rounds of selection, and we demonstrate that the aptamers function effectively in a sandwich binding format. PMID:20689511

Individualizing drug dosage with longitudinal data.

PubMed

Zhu, Xiaolu; Qu, Annie

2016-10-30

We propose a two-step procedure to personalize drug dosage over time under the framework of a log-linear mixed-effect model. We model patients' heterogeneity using subject-specific random effects, which are treated as the realizations of an unspecified stochastic process. We extend the conditional quadratic inference function to estimate both fixed-effect coefficients and individual random effects on a longitudinal training data sample in the first step and propose an adaptive procedure to estimate new patients' random effects and provide dosage recommendations for new patients in the second step. An advantage of our approach is that we do not impose any distribution assumption on estimating random effects. Moreover, the new approach can accommodate more general time-varying covariates corresponding to random effects. We show in theory and numerical studies that the proposed method is more efficient compared with existing approaches, especially when covariates are time varying. In addition, a real data example of a clozapine study confirms that our two-step procedure leads to more accurate drug dosage recommendations. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

MnDOT thin whitetopping selection procedures : final report.

DOT National Transportation Integrated Search

2017-06-01

This report provides an integrated selection procedure for evaluating whether an existing hot-mix asphalt (HMA) pavement is an appropriate candidate for a bonded concrete overlay of asphalt (BCOA). The selection procedure includes (1) a desk review, ...

Working with a fixed operating room team on consecutive similar cases and the effect on case duration and turnover time.

PubMed

Stepaniak, Pieter S; Vrijland, Wietske W; de Quelerij, Marcel; de Vries, Guus; Heij, Christiaan

2010-12-01

If variation in procedure times could be controlled or better predicted, the cost of surgeries could be reduced through improved scheduling of surgical resources. This study on the impact of similar consecutive cases on the turnover, surgical, and procedure times tests the perception that repeating the same manual tasks reduces the duration of these tasks. We hypothesize that when a fixed team works on similar consecutive cases the result will be shorter turnover and procedure duration as well as less variation as compared with the situation without a fixed team. Case-control study. St Franciscus Hospital, a large general teaching hospital in Rotterdam, the Netherlands. Two procedures, inguinal hernia repair and laparoscopic cholecystectomy, were selected and divided across a control group and a study group. Patients were randomly assigned to the study or control group. Preparation time, surgical time, procedure time, and turnover time. For inguinal hernia repair, we found a significantly lower preparation time and 10 minutes less procedure time in the study group, as compared with the control group. Variation in the study group was lower, as compared with the control group. For laparoscopic cholecystectomy, preparation time was significantly lower in the study group, as compared with the control group. For both procedures, there was a significant decrease in turnover time. Scheduling similar consecutive cases and performing with a fixed team results in lower turnover times and preparation times. The procedure time of the inguinal hernia repair decreased significantly and has practical scheduling implications. For more complex surgery, like laparoscopic cholecystectomy, there is no effect on procedure time.

Detailed Analysis of Peri-Procedural Strokes in Patients Undergoing Intracranial Stenting in SAMMPRIS

PubMed Central

Fiorella, David; Derdeyn, Colin P; Lynn, Michael J; Barnwell, Stanley L; Hoh, Brian L.; Levy, Elad I.; Harrigan, Mark R.; Klucznik, Richard P.; McDougall, Cameron G.; Pride, G. Lee; Zaidat, Osama O.; Lutsep, Helmi L.; Waters, Michael F.; Hourihane, J. Maurice; Alexandrov, Andrei V.; Chiu, David; Clark, Joni M.; Johnson, Mark D.; Torbey, Michel T.; Rumboldt, Zoran; Cloft, Harry J.; Turan, Tanya N.; Lane, Bethany F.; Janis, L. Scott; Chimowitz, Marc I.

2012-01-01

Background and Purpose Enrollment in the SAMMPRIS trial was halted due to the high risk of stroke or death within 30 days of enrollment in the percutaneous transluminal angioplasty and stenting (PTAS) arm relative to the medical arm. This analysis focuses on the patient and procedural factors that may have been associated with peri-procedural cerebrovascular events in the trial. Methods Bivariate and multivariate analyses were performed to evaluate whether patient and procedural variables were associated with cerebral ischemic or hemorrhagic events occurring within 30 days of enrollment (termed peri-procedural) in the PTAS arm. Results Of 224 patients randomized to PTAS, 213 underwent angioplasty alone (n=5) or with stenting (n=208). Of these, 13 had hemorrhagic strokes (7 parenchymal, 6 subarachnoid), 19 had ischemic stroke, and 2 had cerebral infarcts with temporary signs (CITS) within the peri-procedural period. Ischemic events were categorized as perforator occlusions (13), embolic (4), mixed perforator and embolic (2), and delayed stent occlusion (2). Multivariate analyses showed that higher percent stenosis, lower modified Rankin score, and clopidogrel load associated with an activated clotting time above the target range were associated (p ≤ 0.05) with hemorrhagic stroke. Non-smoking, basilar artery stenosis, diabetes, and older age were associated (p ≤ 0.05) with ischemic events. Conclusions Peri-procedural strokes in SAMMPRIS had multiple causes with the most common being perforator occlusion. Although risk factors for peri-procedural strokes could be identified, excluding patients with these features from undergoing PTAS to lower the procedural risk would limit PTAS to a small subset of patients. Moreover, given the small number of events, the present data should be used for hypothesis generation rather than to guide patient selection in clinical practice. PMID:22984008

Robust Approach to Verifying the Weak Form of the Efficient Market Hypothesis

NASA Astrophysics Data System (ADS)

Střelec, Luboš

2011-09-01

The weak form of the efficient markets hypothesis states that prices incorporate only past information about the asset. An implication of this form of the efficient markets hypothesis is that one cannot detect mispriced assets and consistently outperform the market through technical analysis of past prices. One of possible formulations of the efficient market hypothesis used for weak form tests is that share prices follow a random walk. It means that returns are realizations of IID sequence of random variables. Consequently, for verifying the weak form of the efficient market hypothesis, we can use distribution tests, among others, i.e. some tests of normality and/or some graphical methods. Many procedures for testing the normality of univariate samples have been proposed in the literature [7]. Today the most popular omnibus test of normality for a general use is the Shapiro-Wilk test. The Jarque-Bera test is the most widely adopted omnibus test of normality in econometrics and related fields. In particular, the Jarque-Bera test (i.e. test based on the classical measures of skewness and kurtosis) is frequently used when one is more concerned about heavy-tailed alternatives. As these measures are based on moments of the data, this test has a zero breakdown value [2]. In other words, a single outlier can make the test worthless. The reason so many classical procedures are nonrobust to outliers is that the parameters of the model are expressed in terms of moments, and their classical estimators are expressed in terms of sample moments, which are very sensitive to outliers. Another approach to robustness is to concentrate on the parameters of interest suggested by the problem under this study. Consequently, novel robust testing procedures of testing normality are presented in this paper to overcome shortcomings of classical normality tests in the field of financial data, which are typical with occurrence of remote data points and additional types of deviations from normality. This study also discusses some results of simulation power studies of these tests for normality against selected alternatives. Based on outcome of the power simulation study, selected normality tests were consequently used to verify weak form of efficiency in Central Europe stock markets.

Spinal cord stimulation versus repeated lumbosacral spine surgery for chronic pain: a randomized, controlled trial.

PubMed

North, Richard B; Kidd, David H; Farrokhi, Farrokh; Piantadosi, Steven A

2005-01-01

Persistent or recurrent radicular pain after lumbosacral spine surgery is often associated with nerve root compression and is treated by repeated operation or, as a last resort, by spinal cord stimulation (SCS). We conducted a prospective, randomized, controlled trial to test our hypothesis that SCS is more likely than reoperation to result in a successful outcome by standard measures of pain relief and treatment outcome, including subsequent use of health care resources. For an average of 3 years postoperatively, disinterested third-party interviewers followed 50 patients selected for reoperation by standard criteria and randomized to SCS or reoperation. If the results of the randomized treatment were unsatisfactory, patients could cross over to the alternative. Success was based on self-reported pain relief and patient satisfaction. Crossover to the alternative procedure was an outcome measure. Use of analgesics, activities of daily living, and work status were self-reported. Among 45 patients (90%) available for follow-up, SCS was more successful than reoperation (9 of 19 patients versus 3 of 26 patients, P <0.01). Patients initially randomized to SCS were significantly less likely to cross over than were those randomized to reoperation (5 of 24 patients versus 14 of 26 patients, P=0.02). Patients randomized to reoperation required increased opiate analgesics significantly more often than those randomized to SCS (P <0.025). Other measures of activities of daily living and work status did not differ significantly. SCS is more effective than reoperation as a treatment for persistent radicular pain after lumbosacral spine surgery, and in the great majority of patients, it obviates the need for reoperation.

Primary Definitive Procedure versus Conventional Three-staged Procedure for the Management of Low-type Anorectal Malformation in Females: A Randomized Controlled Trial.

PubMed

Gupta, Alisha; Agarwala, Sandeep; Sreenivas, Vishnubhatla; Srinivas, Madhur; Bhatnagar, Veereshwar

2017-01-01

Females with Krickenbeck low-type anorectal malformations - vestibular fistula (VF) and perineal fistula (PF) - are managed either by a primary definitive or conventional three-staged approach. Ultimate outcome in these children may be affected by wound dehiscence leading to healing by fibrosis. Most of the literature favors one approach over other based on retrospective analysis of their outcomes. Whether a statistically significant difference in wound dehiscence rates between these approaches exists needed to be seen. A randomized controlled trial for girls <14 years with VF or PF was done. Random tables were used to randomize 33 children to Group I (primary procedure) and 31 to Group II (three-staged procedure). Statistical analysis was done for significance of difference ( P < 0.05) in the primary outcome (wound dehiscence) and secondary outcomes (immediate and early postoperative complications). Of the 64 children randomized, 54 (84%) had VF. Both groups were comparable in demography, clinical profile and age at surgery. The incidence of wound dehiscence (39.4% vs. 18.2%; P = 0.04), immediate postoperative complications (51.5% vs. 12.9%; P = 0.001), and early postoperative complications (42.4% vs. 12.9%; P = 0.01) was significantly higher in Group I as compared to Group II. Six of 13 children (46.2%) with dehiscence in Group I required a diverting colostomy to be made. Females with VF or PF undergoing primary definitive procedure have a significantly higher incidence of wound dehiscence ( P = 0.04), immediate ( P = 0.001) and early postoperative complications ( P = 0.01).

41 CFR 60-3.3 - Discrimination defined: Relationship between use of selection procedures and discrimination.

Code of Federal Regulations, 2013 CFR

2013-07-01

...: Relationship between use of selection procedures and discrimination. 60-3.3 Section 60-3.3 Public Contracts and... PROGRAMS, EQUAL EMPLOYMENT OPPORTUNITY, DEPARTMENT OF LABOR 3-UNIFORM GUIDELINES ON EMPLOYEE SELECTION PROCEDURES (1978) General Principles § 60-3.3 Discrimination defined: Relationship between use of selection...

An RNA motif that binds ATP

NASA Technical Reports Server (NTRS)

Sassanfar, M.; Szostak, J. W.

1993-01-01

RNAs that contain specific high-affinity binding sites for small molecule ligands immobilized on a solid support are present at a frequency of roughly one in 10(10)-10(11) in pools of random sequence RNA molecules. Here we describe a new in vitro selection procedure designed to ensure the isolation of RNAs that bind the ligand of interest in solution as well as on a solid support. We have used this method to isolate a remarkably small RNA motif that binds ATP, a substrate in numerous biological reactions and the universal biological high-energy intermediate. The selected ATP-binding RNAs contain a consensus sequence, embedded in a common secondary structure. The binding properties of ATP analogues and modified RNAs show that the binding interaction is characterized by a large number of close contacts between the ATP and RNA, and by a change in the conformation of the RNA.

Serotonin Augmentation Reduces Response to Attack in Aggressive Individuals

PubMed Central

Berman, Mitchell E.; McCloskey, Michael S.; Fanning, Jennifer R.; Schumacher, Julie A.; Coccaro, Emil F.

2009-01-01

We tested the theory that central serotonin (5- hydroxytryptamine, or 5-HT) activity regulates aggression by modulating response to provocation. Eighty men and women (40 with and 40 without a history of aggression) were randomly assigned to receive either 40 mg of paroxetine (to acutely augment serotonergic activity) or a placebo, administered using double-blind procedures. Aggression was assessed during a competitive reaction time game with a fictitious opponent. Shocks were selected by the participant and opponent before each trial, with the loser on each trial receiving the shock set by the other player. Provocation was manipulated by having the opponent select increasingly intense shocks for the participant and eventually an ostensibly severe shock toward the end of the trials. Aggression was measured by the number of severe shocks set by the participant for the opponent. As predicted, aggressive responding after provocation was attenuated by augmentation of serotonin in individuals with a pronounced history of aggression. PMID:19422623

The effects of a parenting prime on sex differences in mate selection criteria.

PubMed

Millar, Murray G; Ostlund, Nelse M

2006-11-01

This study tested an evolutionary hypothesis that the mere prospect of caring for a child will increase sex differences in human mate selection criteria. That is, women would adopt a stronger preference for socially dominant men when parenting had been primed and men would adopt a stronger preference for physically attractive women when parenting had been primed. Male and female university students were randomly assigned to be exposed to a parenting prime or a nonparenting prime. Following the priming procedure, participants rated the romantic appeal of a target person of the opposite sex. Exposure to the parenting prime, the target's social dominance, and the target's physical attractiveness were orthogonally manipulated. As predicted, women adopted a stronger mate preference for social dominance when parenting was at the forefront of the mind. Contrary to predictions, the parenting prime had no effect on men's mate preference for physical attractiveness.

Stratified and Maximum Information Item Selection Procedures in Computer Adaptive Testing

ERIC Educational Resources Information Center

Deng, Hui; Ansley, Timothy; Chang, Hua-Hua

2010-01-01

In this study we evaluated and compared three item selection procedures: the maximum Fisher information procedure (F), the a-stratified multistage computer adaptive testing (CAT) (STR), and a refined stratification procedure that allows more items to be selected from the high a strata and fewer items from the low a strata (USTR), along with…

Improving the performance of minimizers and winnowing schemes

PubMed Central

Marçais, Guillaume; Pellow, David; Bork, Daniel; Orenstein, Yaron; Shamir, Ron; Kingsford, Carl

2017-01-01

Abstract Motivation: The minimizers scheme is a method for selecting k-mers from sequences. It is used in many bioinformatics software tools to bin comparable sequences or to sample a sequence in a deterministic fashion at approximately regular intervals, in order to reduce memory consumption and processing time. Although very useful, the minimizers selection procedure has undesirable behaviors (e.g. too many k-mers are selected when processing certain sequences). Some of these problems were already known to the authors of the minimizers technique, and the natural lexicographic ordering of k-mers used by minimizers was recognized as their origin. Many software tools using minimizers employ ad hoc variations of the lexicographic order to alleviate those issues. Results: We provide an in-depth analysis of the effect of k-mer ordering on the performance of the minimizers technique. By using small universal hitting sets (a recently defined concept), we show how to significantly improve the performance of minimizers and avoid some of its worse behaviors. Based on these results, we encourage bioinformatics software developers to use an ordering based on a universal hitting set or, if not possible, a randomized ordering, rather than the lexicographic order. This analysis also settles negatively a conjecture (by Schleimer et al.) on the expected density of minimizers in a random sequence. Availability and Implementation: The software used for this analysis is available on GitHub: https://github.com/gmarcais/minimizers.git. Contact: gmarcais@cs.cmu.edu or carlk@cs.cmu.edu PMID:28881970

Increased cognitive load enables unlearning in procedural category learning.

PubMed

Crossley, Matthew J; Maddox, W Todd; Ashby, F Gregory

2018-04-19

Interventions for drug abuse and other maladaptive habitual behaviors may yield temporary success but are often fragile and relapse is common. This implies that current interventions do not erase or substantially modify the representations that support the underlying addictive behavior-that is, they do not cause true unlearning. One example of an intervention that fails to induce true unlearning comes from Crossley, Ashby, and Maddox (2013, Journal of Experimental Psychology: General), who reported that a sudden shift to random feedback did not cause unlearning of category knowledge obtained through procedural systems, and they also reported results suggesting that this failure is because random feedback is noncontingent on behavior. These results imply the existence of a mechanism that (a) estimates feedback contingency and (b) protects procedural learning from modification when feedback contingency is low (i.e., during random feedback). This article reports the results of an experiment in which increasing cognitive load via an explicit dual task during the random feedback period facilitated unlearning. This result is consistent with the hypothesis that the mechanism that protects procedural learning when feedback contingency is low depends on executive function. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Optimal spatial sampling techniques for ground truth data in microwave remote sensing of soil moisture

NASA Technical Reports Server (NTRS)

Rao, R. G. S.; Ulaby, F. T.

1977-01-01

The paper examines optimal sampling techniques for obtaining accurate spatial averages of soil moisture, at various depths and for cell sizes in the range 2.5-40 acres, with a minimum number of samples. Both simple random sampling and stratified sampling procedures are used to reach a set of recommended sample sizes for each depth and for each cell size. Major conclusions from statistical sampling test results are that (1) the number of samples required decreases with increasing depth; (2) when the total number of samples cannot be prespecified or the moisture in only one single layer is of interest, then a simple random sample procedure should be used which is based on the observed mean and SD for data from a single field; (3) when the total number of samples can be prespecified and the objective is to measure the soil moisture profile with depth, then stratified random sampling based on optimal allocation should be used; and (4) decreasing the sensor resolution cell size leads to fairly large decreases in samples sizes with stratified sampling procedures, whereas only a moderate decrease is obtained in simple random sampling procedures.

Using discrete choice modeling to generate resource selection functions for female polar bears in the Beaufort Sea

USGS Publications Warehouse

Durner, George M.; Amstrup, Steven C.; Nielson, Ryan M.; McDonald, Trent; Huzurbazar, Snehalata

2004-01-01

Polar bears (Ursus maritimus) depend on ice-covered seas to satisfy life history requirements. Modern threats to polar bears include oil spills in the marine environment and changes in ice composition resulting from climate change. Managers need practical models that explain the distribution of bears in order to assess the impacts of these threats. We explored the use of discrete choice models to describe habitat selection by female polar bears in the Beaufort Sea. Using stepwise procedures we generated resource selection models of habitat use. Sea ice characteristics and ocean depths at known polar bear locations were compared to the same features at randomly selected locations. Models generated for each of four seasons confirmed complexities of habitat use by polar bears and their response to numerous factors. Bears preferred shallow water areas where different ice types intersected. Variation among seasons was reflected mainly in differential selection of total ice concentration, ice stages, floe sizes, and their interactions. Distance to the nearest ice interface was a significant term in models for three seasons. Water depth was selected as a significant term in all seasons, possibly reflecting higher productivity in shallow water areas. Preliminary tests indicate seasonal models can predict polar bear distribution based on prior sea ice data.

Plant mediated green synthesis: modified approaches.

PubMed

Das, Ratul Kumar; Brar, Satinder Kaur

2013-11-07

Plant mediated green synthesis of different metallic nanoparticles has emerged as one of the options for implementation of green chemistry principles, and successfully made an important contribution towards green nanotechnology. However, beyond the synthesis and application aspects, the science of green synthesis has carried some wrong perceptions in an unforeseen fashion. In this review, some of the key issues related to the green synthesis of metallic nanoparticles employing plants as reducing/capping agents have been addressed. Random selection of plants and its overall impact on the different aspects of green synthesis have been discussed. Emphasis is given to the setting of some standard selection criteria to be adopted for selecting a plant for use in green synthesis. How selection of a plant can positively or negatively influence both procedure and products of a green synthesis process is the prime concern of this article. In addition to selection, the key issue of biocompatibility associated with green synthesized metallic nanoparticles has been considered. Both selection of plant and biocompatibility were reconsidered for their minute details in terms of synthesis, analysis and data interpretation in the green synthesis approach. The key factors capable of fine tuning the core meaning of "green" in the synthesis of any metallic nanoparticles were taken into consideration. This article is an effort towards keeping the core meaning of green synthesis.

High throughput sequencing analysis of RNA libraries reveals the influences of initial library and PCR methods on SELEX efficiency.

PubMed

Takahashi, Mayumi; Wu, Xiwei; Ho, Michelle; Chomchan, Pritsana; Rossi, John J; Burnett, John C; Zhou, Jiehua

2016-09-22

The systemic evolution of ligands by exponential enrichment (SELEX) technique is a powerful and effective aptamer-selection procedure. However, modifications to the process can dramatically improve selection efficiency and aptamer performance. For example, droplet digital PCR (ddPCR) has been recently incorporated into SELEX selection protocols to putatively reduce the propagation of byproducts and avoid selection bias that result from differences in PCR efficiency of sequences within the random library. However, a detailed, parallel comparison of the efficacy of conventional solution PCR versus the ddPCR modification in the RNA aptamer-selection process is needed to understand effects on overall SELEX performance. In the present study, we took advantage of powerful high throughput sequencing technology and bioinformatics analysis coupled with SELEX (HT-SELEX) to thoroughly investigate the effects of initial library and PCR methods in the RNA aptamer identification. Our analysis revealed that distinct "biased sequences" and nucleotide composition existed in the initial, unselected libraries purchased from two different manufacturers and that the fate of the "biased sequences" was target-dependent during selection. Our comparison of solution PCR- and ddPCR-driven HT-SELEX demonstrated that PCR method affected not only the nucleotide composition of the enriched sequences, but also the overall SELEX efficiency and aptamer efficacy.

High throughput sequencing analysis of RNA libraries reveals the influences of initial library and PCR methods on SELEX efficiency

PubMed Central

Takahashi, Mayumi; Wu, Xiwei; Ho, Michelle; Chomchan, Pritsana; Rossi, John J.; Burnett, John C.; Zhou, Jiehua

2016-01-01

The systemic evolution of ligands by exponential enrichment (SELEX) technique is a powerful and effective aptamer-selection procedure. However, modifications to the process can dramatically improve selection efficiency and aptamer performance. For example, droplet digital PCR (ddPCR) has been recently incorporated into SELEX selection protocols to putatively reduce the propagation of byproducts and avoid selection bias that result from differences in PCR efficiency of sequences within the random library. However, a detailed, parallel comparison of the efficacy of conventional solution PCR versus the ddPCR modification in the RNA aptamer-selection process is needed to understand effects on overall SELEX performance. In the present study, we took advantage of powerful high throughput sequencing technology and bioinformatics analysis coupled with SELEX (HT-SELEX) to thoroughly investigate the effects of initial library and PCR methods in the RNA aptamer identification. Our analysis revealed that distinct “biased sequences” and nucleotide composition existed in the initial, unselected libraries purchased from two different manufacturers and that the fate of the “biased sequences” was target-dependent during selection. Our comparison of solution PCR- and ddPCR-driven HT-SELEX demonstrated that PCR method affected not only the nucleotide composition of the enriched sequences, but also the overall SELEX efficiency and aptamer efficacy. PMID:27652575

Autoshaping of chlordiazepoxide drinking in non-deprived rats.

PubMed

Tomie, Arthur; Wong, Lauren E; Pohorecky, Larissa A

2005-02-28

Effects of autoshaping procedures (Paired versus Random) and sipper fluid [chlordiazepoxide (CDP) versus water] on sipper-directed drinking were evaluated in 32 male Long-Evans rats maintained with free access to food and water. For the Paired/CDP group (n = 16), autoshaping procedures consisted of the presentation of the CDP sipper conditioned stimulus (CS) followed by the response-independent presentation of the food unconditioned stimulus (US). The concentration of CDP in the sipper CS (0.05, 0.10, 0.15, 0.20, and 0.25 mg/ml CDP) was increased across sessions. The Paired/Water group (n = 8) received only water in the sipper CS. The Random/CDP group (n = 8) received the CDP sipper CS and food US randomly with respect to one another. The Paired/CDP group drank significantly more of the 0.20 mg/ml and 0.25 mg/ml CDP solutions than the Random/CDP control, and more fluid than the Paired/Water control group when the sipper CS for the Paired/CDP group contained the three highest concentrations of CDP. CS-Only extinction procedures reliably reduced sipper CS-directed drinking in the Paired/CDP and the Paired/Water groups, but not in the Random/CDP group. Data are consistent with the hypothesis that Pavlovian autoshaping procedures induce sipper CS-directed drinking of CDP in rats deprived of neither food nor fluid. Implications for the autoshaping model of drug abuse are discussed.

SSRIs and ejaculation: a double-blind, randomized, fixed-dose study with paroxetine and citalopram.

PubMed

Waldinger, M D; Zwinderman, A H; Olivier, B

2001-12-01

Selective serotonin reuptake inhibitors (SSRIs) are known to induce delayed orgasm and ejaculation. However, different SSRIs may differentially delay ejaculation. A double-blind, fixed-dose study in healthy men with lifelong rapid ejaculation was performed to evaluate potential differences between clinically relevant doses of two selective serotonin reuptake inhibitors, paroxetine and citalopram, in their effects on ejaculation. Thirty men with an intravaginal ejaculation latency time (IELT) less than 1 minute were randomly assigned to receive paroxetine (20 mg/day) and citalopram (20 mg/day) for 5 weeks, after taking half the dosage in the first week. During the 1-month baseline and 6-week treatment period, IELTs were measured at home by using a stopwatch procedure. The trial was completed by 23 men. Analysis of variance revealed a between-group difference in the evolution of IELT delay over time (p = 0.0004); the IELT after paroxetine and citalopram gradually increased from 18 and 21 seconds to approximately 170 and 44 seconds, respectively. Paroxetine 20 mg/day exerted a strong delay (8.9-fold increase), whereas citalopram 20 mg/day mildly delayed ejaculation (1.8-fold increase). These results indicate that paroxetine leads to a significant delay in orgasm and ejaculation, whereas citalopram seems to have less of an effect on it.

High Dimensional Classification Using Features Annealed Independence Rules.

PubMed

Fan, Jianqing; Fan, Yingying

2008-01-01

Classification using high-dimensional features arises frequently in many contemporary statistical studies such as tumor classification using microarray or other high-throughput data. The impact of dimensionality on classifications is largely poorly understood. In a seminal paper, Bickel and Levina (2004) show that the Fisher discriminant performs poorly due to diverging spectra and they propose to use the independence rule to overcome the problem. We first demonstrate that even for the independence classification rule, classification using all the features can be as bad as the random guessing due to noise accumulation in estimating population centroids in high-dimensional feature space. In fact, we demonstrate further that almost all linear discriminants can perform as bad as the random guessing. Thus, it is paramountly important to select a subset of important features for high-dimensional classification, resulting in Features Annealed Independence Rules (FAIR). The conditions under which all the important features can be selected by the two-sample t-statistic are established. The choice of the optimal number of features, or equivalently, the threshold value of the test statistics are proposed based on an upper bound of the classification error. Simulation studies and real data analysis support our theoretical results and demonstrate convincingly the advantage of our new classification procedure.

Chloroacetanilide herbicide metabolites in Wisconsin groundwater: 2001 survey results.

PubMed

Postle, Jeffrey K; Rheineck, Bruce D; Allen, Paula E; Baldock, Jon O; Cook, Cody J; Zogbaum, Randy; Vandenbrook, James P

2004-10-15

A survey of agricultural chemicals in Wisconsin groundwater was conducted between October 2000 and April 2001 to obtain a current picture of agricultural chemicals in groundwater used for private drinking water. A stratified, random sampling procedure was used to select 336 sampling locations. Water from private drinking water wells randomly selected from within the 336 sampling locations was analyzed for 18 compounds including herbicides, herbicide metabolites, and nitrate. This report focuses on the frequency and concentration of chloroacetanilide herbicides and their metabolites. Analysis of data resulted in an estimated proportion of 38+/-5.0% of wells that contained detectable levels of a herbicide or herbicide metabolite. The most commonly detected compound was alachlor ESA with a proportion estimate of 28+/-4.6%. Other detected compounds in order of prevalence were metolachlor ESA, metolachlor OA, alachlor OA, acetochlor ESA, and parent alachlor. Estimates of the mean concentration for the detects ranged from 0.15+/-0.082 microg/L for acetochlor ESA to 1.8+/-0.60 microg/L for alachlor OA. Water quality standards have not been developed for these chloroacetanilide herbicide metabolites. The results of this survey emphasize the need for toxicological assessments of herbicide metabolite compounds and establishment of water quality standards at the state and federal levels.

Stochastic noncooperative and cooperative evolutionary game strategies of a population of biological networks under natural selection.

PubMed

Chen, Bor-Sen; Yeh, Chin-Hsun

2017-12-01

We review current static and dynamic evolutionary game strategies of biological networks and discuss the lack of random genetic variations and stochastic environmental disturbances in these models. To include these factors, a population of evolving biological networks is modeled as a nonlinear stochastic biological system with Poisson-driven genetic variations and random environmental fluctuations (stimuli). To gain insight into the evolutionary game theory of stochastic biological networks under natural selection, the phenotypic robustness and network evolvability of noncooperative and cooperative evolutionary game strategies are discussed from a stochastic Nash game perspective. The noncooperative strategy can be transformed into an equivalent multi-objective optimization problem and is shown to display significantly improved network robustness to tolerate genetic variations and buffer environmental disturbances, maintaining phenotypic traits for longer than the cooperative strategy. However, the noncooperative case requires greater effort and more compromises between partly conflicting players. Global linearization is used to simplify the problem of solving nonlinear stochastic evolutionary games. Finally, a simple stochastic evolutionary model of a metabolic pathway is simulated to illustrate the procedure of solving for two evolutionary game strategies and to confirm and compare their respective characteristics in the evolutionary process. Copyright © 2017 Elsevier B.V. All rights reserved.

Pricing of common cosmetic surgery procedures: local economic factors trump supply and demand.

PubMed

Richardson, Clare; Mattison, Gennaya; Workman, Adrienne; Gupta, Subhas

2015-02-01

The pricing of cosmetic surgery procedures has long been thought to coincide with laws of basic economics, including the model of supply and demand. However, the highly variable prices of these procedures indicate that additional economic contributors are probable. The authors sought to reassess the fit of cosmetic surgery costs to the model of supply and demand and to determine the driving forces behind the pricing of cosmetic surgery procedures. Ten plastic surgery practices were randomly selected from each of 15 US cities of various population sizes. Average prices of breast augmentation, mastopexy, abdominoplasty, blepharoplasty, and rhytidectomy in each city were compared with economic and demographic statistics. The average price of cosmetic surgery procedures correlated substantially with population size (r = 0.767), cost-of-living index (r = 0.784), cost to own real estate (r = 0.714), and cost to rent real estate (r = 0.695) across the 15 US cities. Cosmetic surgery pricing also was found to correlate (albeit weakly) with household income (r = 0.436) and per capita income (r = 0.576). Virtually no correlations existed between pricing and the density of plastic surgeons (r = 0.185) or the average age of residents (r = 0.076). Results of this study demonstrate a correlation between costs of cosmetic surgery procedures and local economic factors. Cosmetic surgery pricing cannot be completely explained by the supply-and-demand model because no association was found between procedure cost and the density of plastic surgeons. © 2015 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

41 CFR 60-3.3 - Discrimination defined: Relationship between use of selection procedures and discrimination.

Code of Federal Regulations, 2010 CFR

2010-07-01

... employment or membership opportunities of members of any race, sex, or ethnic group will be considered to be... selection procedures and suitable alternative methods of using the selection procedure which have as little...

41 CFR 60-3.3 - Discrimination defined: Relationship between use of selection procedures and discrimination.

Code of Federal Regulations, 2014 CFR

2014-07-01

... employment or membership opportunities of members of any race, sex, or ethnic group will be considered to be... selection procedures and suitable alternative methods of using the selection procedure which have as little...

41 CFR 60-3.3 - Discrimination defined: Relationship between use of selection procedures and discrimination.

Code of Federal Regulations, 2012 CFR

2012-07-01

... employment or membership opportunities of members of any race, sex, or ethnic group will be considered to be... selection procedures and suitable alternative methods of using the selection procedure which have as little...

41 CFR 60-3.3 - Discrimination defined: Relationship between use of selection procedures and discrimination.

Code of Federal Regulations, 2011 CFR

2011-07-01

... employment or membership opportunities of members of any race, sex, or ethnic group will be considered to be... selection procedures and suitable alternative methods of using the selection procedure which have as little...

Outcome of tactile conditioning of neonates, or "imprint training" on selected handling measures in foals.

PubMed

Spier, Sharon J; Berger Pusterla, Jeannine; Villarroel, Aurora; Pusterla, Nicola

2004-11-01

Behavioural reactions to selected handling procedures were compared between conditioned, or imprint-trained, and untrained foals raised on the same farm. Nineteen randomly chosen healthy foals were imprint trained at birth and 24 h later (Group A). Twenty-one similar foals that were not imprint-trained served as age-matched controls (Group B). Training began within 10 min of birth and consisted of touch desensitization by gentle rubbing. Each tactile stimulus was repeated 30-50 times over 45-60 min, until the foal no longer resisted the procedure and appeared relaxed. The procedure was then repeated at 24 h of age. At that time a physical examination and blood analysis were performed to assess the foals' health status. Group B animals were not handled except for a brief physical examination and blood analysis at 24 h of age. Thereafter all foals were kept on pastures with their dams with no further handling until they were three months of age. Any foals handled for other reasons before that time were excluded from the study. At three months, each of the 28 foals that completed the study experienced the following handling procedures: acceptance of restraint, haltering, complete physical examination, acceptance of a plastic rebreathing bag, touching the whole body, intramuscular vaccination in the neck, intranasal vaccination, and deworming with oral paste. Response to each procedure was scored (1=not resistant, 2=low resistance, 3=strong resistance, 4=not possible without major physical restraint). Conditioned foals (Group A) were significantly less resistant to touching the front and hind legs and picking up the hind feet (P < 0.05). The administration of vaccines and paste dewormer and the collection of blood were tolerated by the majority of the foals of both groups with no or low resistance. It appeared that neonatal imprint training resulted in a learned behaviour that resulted in decreased self-defence responses towards handling the limbs at three months of age.

A selective-update affine projection algorithm with selective input vectors

NASA Astrophysics Data System (ADS)

Kong, NamWoong; Shin, JaeWook; Park, PooGyeon

2011-10-01

This paper proposes an affine projection algorithm (APA) with selective input vectors, which based on the concept of selective-update in order to reduce estimation errors and computations. The algorithm consists of two procedures: input- vector-selection and state-decision. The input-vector-selection procedure determines the number of input vectors by checking with mean square error (MSE) whether the input vectors have enough information for update. The state-decision procedure determines the current state of the adaptive filter by using the state-decision criterion. As the adaptive filter is in transient state, the algorithm updates the filter coefficients with the selected input vectors. On the other hand, as soon as the adaptive filter reaches the steady state, the update procedure is not performed. Through these two procedures, the proposed algorithm achieves small steady-state estimation errors, low computational complexity and low update complexity for colored input signals.

Impact of a bronchial genomic classifier on clinical decision making in patients undergoing diagnostic evaluation for lung cancer.

PubMed

Ferguson, J Scott; Van Wert, Ryan; Choi, Yoonha; Rosenbluth, Michael J; Smith, Kate Porta; Huang, Jing; Spira, Avrum

2016-05-17

Bronchoscopy is frequently used for the evaluation of suspicious pulmonary lesions found on computed tomography, but its sensitivity for detecting lung cancer is limited. Recently, a bronchial genomic classifier was validated to improve the sensitivity of bronchoscopy for lung cancer detection, demonstrating a high sensitivity and negative predictive value among patients at intermediate risk (10-60 %) for lung cancer with an inconclusive bronchoscopy. Our objective for this study was to determine if a negative genomic classifier result that down-classifies a patient from intermediate risk to low risk (<10 %) for lung cancer would reduce the rate that physicians recommend more invasive testing among patients with an inconclusive bronchoscopy. We conducted a randomized, prospective, decision impact survey study assessing pulmonologist recommendations in patients undergoing workup for lung cancer who had an inconclusive bronchoscopy. Cases with an intermediate pretest risk for lung cancer were selected from the AEGIS trials and presented in a randomized fashion to pulmonologists either with or without the patient's bronchial genomic classifier result to determine how the classifier results impacted physician decisions. Two hundred two physicians provided 1523 case evaluations on 36 patients. Invasive procedure recommendations were reduced from 57 % without the classifier result to 18 % with a negative (low risk) classifier result (p < 0.001). Invasive procedure recommendations increased from 50 to 65 % with a positive (intermediate risk) classifier result (p < 0.001). When stratifying by ultimate disease diagnosis, there was an overall reduction in invasive procedure recommendations in patients with benign disease when classifier results were reported (54 to 41 %, p < 0.001). For patients ultimately diagnosed with malignant disease, there was an overall increase in invasive procedure recommendations when the classifier results were reported (50 to 64 %, p = 0.003). Our findings suggest that a negative (low risk) bronchial genomic classifier result reduces invasive procedure recommendations following an inconclusive bronchoscopy and that the classifier overall reduces invasive procedure recommendations among patients ultimately diagnosed with benign disease. These results support the potential clinical utility of the classifier to improve management of patients undergoing bronchoscopy for suspect lung cancer by reducing additional invasive procedures in the setting of benign disease.

Music to reduce pain and distress in the pediatric emergency department: a randomized clinical trial.

PubMed

Hartling, Lisa; Newton, Amanda S; Liang, Yuanyuan; Jou, Hsing; Hewson, Krista; Klassen, Terry P; Curtis, Sarah

2013-09-01

Many medical procedures aimed at helping children cause them pain and distress, which can have long-lasting negative effects. Music is a form of distraction that may alleviate some of the pain and distress experienced by children while undergoing medical procedures. To compare music with standard care to manage pain and distress. Randomized clinical trial conducted in a pediatric emergency department with appropriate sequence generation and adequate allocation concealment from January 1, 2009, to March 31, 2010. Individuals assessing the primary outcome were blind to treatment allocation. A total of 42 children aged 3 to 11 years undergoing intravenous placement were included. Music (recordings selected by a music therapist via ambient speakers) vs standard care. The primary outcome was behavioral distress assessed blinded using the Observational Scale of Behavioral Distress-Revised. The secondary outcomes included child-reported pain, heart rate, parent and health care provider satisfaction, ease of performing the procedure, and parental anxiety. With or without controlling for potential confounders, we found no significant difference in the change in behavioral distress from before the procedure to immediately after the procedure. When children who had no distress during the procedure were removed from the analysis, there was a significantly less increase in distress for the music group (standard care group = 2.2 vs music group = 1.1, P < .05). Pain scores among children in the standard care group increased by 2 points, while they remained the same in the music group (P = .04); the difference was considered clinically important. The pattern of parent satisfaction with the management of children's pain was different between groups, although not statistically significant (P = .07). Health care providers reported that it was easier to perform the procedure for children in the music group (76% very easy) vs the standard care group (38% very easy) (P = .03). Health care providers were more satisfied with the intravenous placement in the music group (86% very satisfied) compared with the standard care group (48%) (P = .02). Music may have a positive impact on pain and distress for children undergoing intravenous placement. Benefits were also observed for the parents and health care providers. clinicaltrials.gov Identifier: NCT00761033.

Costs of revascularization over eight years in the randomized and eligible patients in the Emory Angioplasty versus Surgery Trial (EAST).

PubMed

Weintraub, W S; Becker, E R; Mauldin, P D; Culler, S; Kosinski, A S; King, S B

2000-10-01

The Emory Angioplasty versus Surgery Trial (EAST) was a randomized trial that compared, by intention to treat, the clinical outcome and costs of percutaneous transluminal coronary angioplasty (PTCA) and coronary bypass grafting (CABG) for multivessel coronary artery disease. We present the findings of the economic analysis of EAST through 8 years of follow-up and compare the cost and outcomes of patients randomized in EAST versus patients eligible but not randomized (registry patients). Charges were assessed from hospital UB82 and UB92 bills and professional charges from the Emory Clinic. Hospital charges were reduced to cost through step-down accounting methods. All costs and charges were inflated to 1997 dollars. Costs were assessed for initial hospitalization and for cumulative costs of the initial hospitalization and additional revascularization procedures up to 8 years. Total 8-year costs were $46,548 for CABG and $44,491 for PTCA (p = 0.37). Cost of CABG in the eligible registry group showed a pattern similar to that for randomized patients, but total cost of PTCA was lower for registry patients than for randomized patients. Thus, the primary procedural costs of CABG are more than those for PTCA; this cost advantage, given the limits of measurement, is largely or even completely lost for randomized patients over the course of 8 years because of additional procedures after a first revascularization by PTCA.

A DNA fingerprinting procedure for ultra high-throughput genetic analysis of insects.

PubMed

Schlipalius, D I; Waldron, J; Carroll, B J; Collins, P J; Ebert, P R

2001-12-01

Existing procedures for the generation of polymorphic DNA markers are not optimal for insect studies in which the organisms are often tiny and background molecular information is often non-existent. We have used a new high throughput DNA marker generation protocol called randomly amplified DNA fingerprints (RAF) to analyse the genetic variability in three separate strains of the stored grain pest, Rhyzopertha dominica. This protocol is quick, robust and reliable even though it requires minimal sample preparation, minute amounts of DNA and no prior molecular analysis of the organism. Arbitrarily selected oligonucleotide primers routinely produced approximately 50 scoreable polymorphic DNA markers, between individuals of three independent field isolates of R. dominica. Multivariate cluster analysis using forty-nine arbitrarily selected polymorphisms generated from a single primer reliably separated individuals into three clades corresponding to their geographical origin. The resulting clades were quite distinct, with an average genetic difference of 37.5 +/- 6.0% between clades and of 21.0 +/- 7.1% between individuals within clades. As a prelude to future gene mapping efforts, we have also assessed the performance of RAF under conditions commonly used in gene mapping. In this analysis, fingerprints from pooled DNA samples accurately and reproducibly reflected RAF profiles obtained from individual DNA samples that had been combined to create the bulked samples.

Cross-talk free selective reconstruction of individual objects from multiplexed optical field data

NASA Astrophysics Data System (ADS)

Zea, Alejandro Velez; Barrera, John Fredy; Torroba, Roberto

2018-01-01

In this paper we present a data multiplexing method for simultaneous storage in a single package composed by several optical fields of tridimensional (3D) objects, and their individual cross-talk free retrieval. Optical field data are extracted from off axis Fourier holograms, and then sampled by multiplying them with random binary masks. The resulting sampled optical fields can be used to reconstruct the original objects. Sampling causes a loss of quality that can be controlled by the number of white pixels in the binary masks and by applying a padding procedure on the optical field data. This process can be performed using a different binary mask for each optical field, and then added to form a multiplexed package. With the adequate choice of sampling and padding, we can achieve a volume reduction in the multiplexed package over the addition of all individual optical fields. Moreover, the package can be multiplied by a binary mask to select a specific optical field, and after the reconstruction procedure, the corresponding 3D object is recovered without any cross-talk. We demonstrate the effectiveness of our proposal for data compression with a comparison with discrete cosine transform filtering. Experimental results confirm the validity of our proposal.

Radiotherapy setup displacements in breast cancer patients: 3D surface imaging experience.

PubMed

Cravo Sá, Ana; Fermento, Ana; Neves, Dalila; Ferreira, Sara; Silva, Teresa; Marques Coelho, Carina; Vaandering, Aude; Roma, Ana; Quaresma, Sérgio; Bonnarens, Emmanuel

2018-01-01

In this study, we intend to compare two different setup procedures for female breast cancer patients. Imaging in radiotherapy provides a precise localization of the tumour, increasing the accuracy of the treatment delivery in breast cancer. Twenty breast cancer patients who underwent whole breast radiotherapy (WBRT) were selected for this study. Patients were divided into two groups of ten. Group one (G1) was positioned by tattoos and then the patient positioning was adjusted with the aid of AlignRT (Vision RT, London, UK). In group two (G2), patients were positioned only by tattoos. For both groups, the first 15 fractions were analyzed, a daily kilovoltage (kV) cone beam computed tomography (CBCT) image was made and then the rotational and translational displacements and, posteriorly, the systematic ( Σ ) and random ( σ ) errors were analyzed. The comparison of CBCT displacements for the two groups showed a statistically significant difference in the translational left-right (LR) direction ( ρ  = 0.03), considering that the procedure with AlignRT system has smaller lateral displacements. The results of systematic ( Σ ) and random ( σ ) errors showed that for translational displacements the group positioned only by tattoos (G2) demonstrated higher values of errors when compared with the group positioned with the aid of AlignRT (G1). AlignRT could help the positioning of breast cancer patients; however, it should be used with another imaging method.

Response rate, response time, and economic costs of survey research: A randomized trial of practicing pharmacists.

PubMed

Hardigan, Patrick C; Popovici, Ioana; Carvajal, Manuel J

2016-01-01

There is a gap between increasing demands from pharmacy journals, publishers, and reviewers for high survey response rates and the actual responses often obtained in the field by survey researchers. Presumably demands have been set high because response rates, times, and costs affect the validity and reliability of survey results. Explore the extent to which survey response rates, average response times, and economic costs are affected by conditions under which pharmacist workforce surveys are administered. A random sample of 7200 U.S. practicing pharmacists was selected. The sample was stratified by delivery method, questionnaire length, item placement, and gender of respondent for a total of 300 observations within each subgroup. A job satisfaction survey was administered during March-April 2012. Delivery method was the only classification showing significant differences in response rates and average response times. The postal mail procedure accounted for the highest response rates of completed surveys, but the email method exhibited the quickest turnaround. A hybrid approach, consisting of a combination of postal and electronic means, showed the least favorable results. Postal mail was 2.9 times more cost effective than the email approach and 4.6 times more cost effective than the hybrid approach. Researchers seeking to increase practicing pharmacists' survey participation and reduce response time and related costs can benefit from the analytical procedures tested here. Copyright © 2016 Elsevier Inc. All rights reserved.

Efficacy and safety of 1% ropivacaine for postoperative analgesia after lower third molar surgery: a prospective, randomized, double-blinded clinical study.

PubMed

Brković, Božidar; Andrić, Miroslav; Ćalasan, Dejan; Milić, Marija; Stepić, Jelena; Vučetić, Milan; Brajković, Denis; Todorović, Ljubomir

2017-04-01

The purpose of this study was to investigate postoperative analgesic effect of ropivacaine administered as main or supplemental injection for the inferior alveolar nerve block (IANB) in patients undergoing lower third molar surgery. The double-blind randomized study comprised 72 healthy patients. All patients received two blocks, the IANB for surgical procedure + IANB after surgery for postoperative pain control, and were divided into three groups: (1) 2 % lidocaine/epinephrine + 1 % ropivacaine, (2) 2 % lidocaine/epinephrine + saline, and (3) 1 % ropivacaine + saline. The occurrence of postoperative pain, pain intensity and analgesic requirements were recorded. Data were statistically analyzed using chi-square, Fisher, and Kruskal-Wallis tests and analysis of variance (ANOVA) with Bonferroni and Tukey correction. Ropivacaine was more successful than lidocaine/epinephrine in obtaining duration of postoperative analgesia, reduction of pain, and analgesic requirements whether ropivacaine was used for surgical block or administered as a supplemental injection after surgery. Ropivacaine (1 %, 2 ml) resulted in effective postoperative analgesia after lower third molar surgery. Since pain control related to third molar surgery requires the effective surgical anesthesia and postoperative analgesia, the use of 1 % ropivacaine could be clinically relevant in a selection of appropriate pain control regimen for both surgical procedure and early postsurgical treatment.

China Angioplasty and Stenting for Symptomatic Intracranial Severe Stenosis (CASSISS): A new, prospective, multicenter, randomized controlled trial in China

PubMed Central

Gao, Peng; Zhao, Zhenwei; Wang, Daming; Wu, Jian; Cai, Yiling; Li, Tianxiao; Wu, Wei; Shi, Huaizhang; He, Weiwen; Zhu, Fengshui; Ling, Feng

2015-01-01

Background Patients with symptomatic stenosis of intradural arteries are at high risk for subsequent stroke. Since the SAMMPRIS trial, stenting is no longer recommended as primary treatment; however, the results of this trial, its inclusion criteria and its center selection received significant criticism and did not appear to reflect our experience regarding natural history nor treatment complications rate. As intracranial atherosclerosis (ICAS) is the most common cause for stroke in Asian countries, we are hereby proposing a refined prospective, randomized, multicenter study in an Asian population with strictly defined patient and participating center inclusion criteria. Methods The China Angioplasty and Stenting for Symptomatic Intracranial Severe Stenosis (CASSISS) trial is an ongoing, government-funded, prospective, multicenter, randomized trial. It recruits patients with recent TIA or stroke caused by 70%–99% stenosis of a major intracranial artery. Patients with previous stroke related to perforator ischemia will not be included. Only high-volume centers with a proven track record will enroll patients as determined by a lead-in phase. Patients will be randomized (1:1) to best medical therapy alone or medical therapy plus stenting. Primary endpoints are any stroke or death within 30 days after enrollment or after any revascularization procedure of the qualifying lesion during follow-up, or stroke in the territory of the symptomatic intracranial artery beyond 30 days. The CASSISS trial will be conducted in eight sites in China with core imaging lab review at a North American site and aims to have a sample size of 380 participants (stenting, 190; medical therapy, 190). Recruitment is expected to be finished by December 2016. Patients will be followed for at least three years. The trial is scheduled to complete in 2019. Conclusion In the proposed trial, certain shortcomings of SAMMPRIS including patient and participating center selection will be addressed. The present manuscript outlines the rationale and design of the study. We estimate that this trial will allow for a critical reappraisal of the role of intracranial stenting for selected patients in high-volume centers. PMID:25934656

Conceptualizing and Testing Random Indirect Effects and Moderated Mediation in Multilevel Models: New Procedures and Recommendations

ERIC Educational Resources Information Center

Bauer, Daniel J.; Preacher, Kristopher J.; Gil, Karen M.

2006-01-01

The authors propose new procedures for evaluating direct, indirect, and total effects in multilevel models when all relevant variables are measured at Level 1 and all effects are random. Formulas are provided for the mean and variance of the indirect and total effects and for the sampling variances of the average indirect and total effects.…

Postoperative Early Major and Minor Complications in Laparoscopic Vertical Sleeve Gastrectomy (LVSG) Versus Laparoscopic Roux-en-Y Gastric Bypass (LRYGB) Procedures: A Meta-Analysis and Systematic Review.

PubMed

Osland, Emma; Yunus, Rossita Mohamad; Khan, Shahjahan; Alodat, Tareq; Memon, Breda; Memon, Muhammed Ashraf

2016-10-01

Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic vertical sleeve gastrectomy (LVSG) have been proposed as cost-effective strategies to manage obesity-related chronic disease. The aim of this meta-analysis and systematic review was to compare the "early postoperative complication rate i.e. within 30-days" reported from randomized control trials (RCTs) comparing these two procedures. RCTs comparing the early complication rates following LVSG and LRYGB between 2000 and 2015 were selected from PubMed, Medline, Embase, Science Citation Index, Current Contents, and the Cochrane database. The outcome variables analyzed included 30-day mortality, major and minor complications and interventions required for their management, length of hospital stay, readmission rates, operating time, and conversions from laparoscopic to open procedures. Six RCTs involving a total of 695 patients (LVSG n = 347, LRYGB n = 348) reported on early major complications. A statistically significant reduction in relative odds of early major complications favoring the LVSG procedure was noted (p = 0.05). Five RCTs representing 633 patients (LVSG n = 317, LRYGB n = 316) reported early minor complications. A non-statically significant reduction in relative odds of 29 % favoring the LVSG procedure was observed for early minor complications (p = 0.4). However, other outcomes directly related to complications which included reoperation rates, readmission rate, and 30-day mortality rate showed comparable effect size for both surgical procedures. This meta-analysis and systematic review of RCTs suggests that fewer early major and minor complications are associated with LVSG compared with LRYGB procedure. However, this does not translate into higher readmission rate, reoperation rate, or 30-day mortality for either procedure.

Periodontal regeneration around natural teeth.

PubMed

Garrett, S

1996-11-01

1. Evidence is conclusive (Table 2) that periodontal regeneration in humans is possible following the use of bone grafts, guided tissue regeneration procedures, both without and in combination with bone grafts, and root demineralization procedures. 2. Clinically guided tissue regeneration procedures have demonstrated significant positive clinical change beyond that achieved with debridement alone in treating mandibular and maxillary (buccal only) Class II furcations. Similar data exist for intraosseous defects. Evidence suggests that the use of bone grafts or GTR procedures produce equal clinical benefit in treating intraosseous defects. Further research is necessary to evaluate GTR procedures compared to, or combined with, bone grafts in treating intraosseous defects. 3. Although there are some data suggesting hopeful results in Class II furcations, the clinical advantage of procedures combining present regenerative techniques remains to be demonstrated. Additional randomized controlled trials with sufficient power are needed to demonstrate the potential usefulness of these techniques. 4. Outcomes following regenerative attempts remain somewhat variable with differences in results between studies and individual subjects. Some of this variability is likely patient related in terms of compliance with plaque control and maintenance procedures, as well as personal habits; e.g., smoking. Variations in the defects selected for study may also affect predictability of outcomes along with other factors. 5. There is evidence to suggest that present regenerative techniques lead to significant amounts of regeneration at localized sites on specific teeth. However, if complete regeneration is to become a reality, additional stimuli to enhance the regenerative process are likely needed. Perhaps this will be accomplished in the future, with combined procedures that include appropriate polypeptide growth factors or tissue factors to provide additional stimulus.

29 CFR 1606.6 - Selection procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 4 2012-07-01 2012-07-01 false Selection procedures. 1606.6 Section 1606.6 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION GUIDELINES ON DISCRIMINATION... the use of the following selection procedures may be discriminatory on the basis of national origin...

29 CFR 1606.6 - Selection procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 4 2011-07-01 2011-07-01 false Selection procedures. 1606.6 Section 1606.6 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION GUIDELINES ON DISCRIMINATION... the use of the following selection procedures may be discriminatory on the basis of national origin...

29 CFR 1606.6 - Selection procedures.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 4 2014-07-01 2014-07-01 false Selection procedures. 1606.6 Section 1606.6 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION GUIDELINES ON DISCRIMINATION... the use of the following selection procedures may be discriminatory on the basis of national origin...

29 CFR 1606.6 - Selection procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 4 2010-07-01 2010-07-01 false Selection procedures. 1606.6 Section 1606.6 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION GUIDELINES ON DISCRIMINATION... the use of the following selection procedures may be discriminatory on the basis of national origin...

29 CFR 1606.6 - Selection procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 4 2013-07-01 2013-07-01 false Selection procedures. 1606.6 Section 1606.6 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION GUIDELINES ON DISCRIMINATION... the use of the following selection procedures may be discriminatory on the basis of national origin...

29 CFR 1607.18 - Citations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... SELECTION PROCEDURES (1978) Appendix § 1607.18 Citations. The official title of these guidelines is “Uniform Guidelines on Employee Selection Procedures (1978)”. The Uniform Guidelines on Employee Selection Procedures... employment practices on grounds of race, color, religion, sex, or national origin. These guidelines have been...

29 CFR 1607.18 - Citations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... SELECTION PROCEDURES (1978) Appendix § 1607.18 Citations. The official title of these guidelines is “Uniform Guidelines on Employee Selection Procedures (1978)”. The Uniform Guidelines on Employee Selection Procedures... employment practices on grounds of race, color, religion, sex, or national origin. These guidelines have been...

29 CFR 1607.18 - Citations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... SELECTION PROCEDURES (1978) Appendix § 1607.18 Citations. The official title of these guidelines is “Uniform Guidelines on Employee Selection Procedures (1978)”. The Uniform Guidelines on Employee Selection Procedures... employment practices on grounds of race, color, religion, sex, or national origin. These guidelines have been...

29 CFR 1607.18 - Citations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... SELECTION PROCEDURES (1978) Appendix § 1607.18 Citations. The official title of these guidelines is “Uniform Guidelines on Employee Selection Procedures (1978)”. The Uniform Guidelines on Employee Selection Procedures... employment practices on grounds of race, color, religion, sex, or national origin. These guidelines have been...

29 CFR 1607.18 - Citations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... SELECTION PROCEDURES (1978) Appendix § 1607.18 Citations. The official title of these guidelines is “Uniform Guidelines on Employee Selection Procedures (1978)”. The Uniform Guidelines on Employee Selection Procedures... employment practices on grounds of race, color, religion, sex, or national origin. These guidelines have been...

Design of state-feedback controllers including sensitivity reduction, with applications to precision pointing

NASA Technical Reports Server (NTRS)

Hadass, Z.

1974-01-01

The design procedure of feedback controllers was described and the considerations for the selection of the design parameters were given. The frequency domain properties of single-input single-output systems using state feedback controllers are analyzed, and desirable phase and gain margin properties are demonstrated. Special consideration is given to the design of controllers for tracking systems, especially those designed to track polynomial commands. As an example, a controller was designed for a tracking telescope with a polynomial tracking requirement and some special features such as actuator saturation and multiple measurements, one of which is sampled. The resulting system has a tracking performance comparing favorably with a much more complicated digital aided tracker. The parameter sensitivity reduction was treated by considering the variable parameters as random variables. A performance index is defined as a weighted sum of the state and control convariances that sum from both the random system disturbances and the parameter uncertainties, and is minimized numerically by adjusting a set of free parameters.

Sustained State-Independent Quantum Contextual Correlations from a Single Ion

NASA Astrophysics Data System (ADS)

Leupold, F. M.; Malinowski, M.; Zhang, C.; Negnevitsky, V.; Alonso, J.; Home, J. P.; Cabello, A.

2018-05-01

We use a single trapped-ion qutrit to demonstrate the quantum-state-independent violation of noncontextuality inequalities using a sequence of randomly chosen quantum nondemolition projective measurements. We concatenate 53 ×106 sequential measurements of 13 observables, and unambiguously violate an optimal noncontextual bound. We use the same data set to characterize imperfections including signaling and repeatability of the measurements. The experimental sequence was generated in real time with a quantum random number generator integrated into our control system to select the subsequent observable with a latency below 50 μ s , which can be used to constrain contextual hidden-variable models that might describe our results. The state-recycling experimental procedure is resilient to noise and independent of the qutrit state, substantiating the fact that the contextual nature of quantum physics is connected to measurements and not necessarily to designated states. The use of extended sequences of quantum nondemolition measurements finds applications in the fields of sensing and quantum information.

Design challenges in transdiagnostic psychotherapy research: Comparing Transdiagnostic Behavior Therapy (TBT) to existing evidence-based psychotherapy in veterans with affective disorders.

PubMed

Gros, Daniel F

2015-07-01

To address the limitations of disorder-specific approaches, newer transdiagnostic approaches to psychotherapy have been developed to provide a single treatment that is capable of addressing several, related disorders. However, the recruitment of multiple diagnoses presents many challenges to the traditional design of psychotherapy randomized controlled trials (RCTs). The goal of the manuscript is to present the challenges and rationale for designing a RCT for transdiagnostic treatment to inform and aid in the development of future investigations. A recently funded and ongoing RCT for Transdiagnostic Behavior Therapy (TBT) is used as an example to discuss the related design challenges. The TBT study involves the recruitment of 96 veteran participants with any of the following eight principal diagnoses: posttraumatic stress disorder, panic disorder, social anxiety disorder, obsessive compulsive disorder, generalized anxiety disorder, specific phobia, major depressive disorder, or persistent depressive disorder. Within the TBT study, participants will complete a semi-structured diagnostic interview and a series of transdiagnostic self-report measures to determine eligibility and assess baseline symptomatology. Qualifying participants will be randomized to TBT or control psychotherapy. Additional assessments will be completed at post-treatment and 6-month follow-up. Due to the transdiagnostic nature of the sample, adjustments to the recruitment and randomization procedures, selection of measures, selection of control psychotherapy, and analysis plan were required. These adjustments have implications to future trials on transdiagnostic psychotherapy protocols as well as future research in line with the transdiagnostic focus of the National Institute of Mental Health's Research Domain Criteria (RDoC) funding strategy. Published by Elsevier Inc.

Major System Source Evaluation and Selection Procedures.

DTIC Science & Technology

1987-04-02

A-RIBI I" MAJOR SYSTEM SOURCE EVALUATION AND SELECTION PROCEDURES / (U) BUSINESS MANAGEMENT RESEARCH ASSOCIATES INC ARLINGTON VA 02 APR 6? ORMC-5...BRMC-85-5142-1 0 I- MAJOR SYSTEM SOURCE EVALUATION AND SELECTION PROCEDURES o I Business Management Research Associates, Inc. 1911 Jefferson Davis...FORCE SOURCE EVALUATION AND SELECTI ON PROCEDURES Prepared by Business Management Research Associates, Inc., 1911 Jefferson Davis Highway, Arlington

Enhanced recovery after elective coronary revascularization surgery with minimal versus conventional extracorporeal circulation: a prospective randomized study.

PubMed

Anastasiadis, Kyriakos; Asteriou, Christos; Antonitsis, Polychronis; Argiriadou, Helena; Grosomanidis, Vassilios; Kyparissa, Magdalena; Deliopoulos, Apostolos; Konstantinou, Dimitrios; Tossios, Paschalis

2013-10-01

A minimal extracorporeal circulation (MECC) circuit integrates the advances in cardiopulmonary bypass (CPB) technology into a single circuit and is associated with improved short-term outcome. The aim of this study was to prospectively evaluate MECC compared with conventional CPB in facilitating fast-track recovery after elective coronary revascularization procedures. Prospective randomized study. All patients scheduled for elective coronary artery surgery were evaluated, excluding those considered particularly high risk for fast-track failure. The fast-track protocol included careful preoperative patient selection, a fast-track anesthetic technique based on minimal administration of fentanyl, surgery at normothermia, early postoperative extubation in the cardiac recovery unit, and admission to the cardiothoracic ward within the first 24 hours postoperatively. One hundred twenty patients were assigned randomly into 2 groups (60 in each group). Group A included patients who were operated on using the MECC circuit, whereas patients in Group B underwent surgery on conventional CPB. Incidence of fast-track recovery was significantly higher in patients undergoing MECC (25% v 6.7%, p = 0.006). MECC also was recognized as a strong independent predictor of early recovery, with an odds ratio of 3.8 (p = 0.011). Duration of mechanical ventilation and cardiac recovery unit stay were significantly lower in patients undergoing MECC together with the need for blood transfusion, duration of inotropic support, need for an intra-aortic balloon pump, and development of postoperative atrial fibrillation and renal failure. MECC promotes successful early recovery after elective coronary revascularization procedures, even in a nondedicated cardiac intensive care unit setting. Copyright © 2013 Elsevier Inc. All rights reserved.

Bipolar plasma vaporization using plasma-cutting and plasma-loop electrodes versus cold-knife transurethral incision for the treatment of posterior urethral stricture: a prospective, randomized study.

PubMed

Cai, Wansong; Chen, Zhiyuan; Wen, Liping; Jiang, Xiangxin; Liu, Xiuheng

2016-01-01

Evaluate the efficiency and safety of bipolar plasma vaporization using plasma-cutting and plasma-loop electrodes for the treatment of posterior urethral stricture. Compare the outcomes following bipolar plasma vaporization with conventional cold-knife urethrotomy. A randomized trial was performed to compare patient outcomes from the bipolar and cold-knife groups. All patients were assessed at 6 and 12 months postoperatively via urethrography and uroflowmetry. At the end of the first postoperative year, ureteroscopy was performed to evaluate the efficacy of the procedure. The mean follow-up time was 13.9 months (range: 12 to 21 months). If re-stenosis was not identified by both urethrography and ureteroscopy, the procedure was considered "successful". Fifty-three male patients with posterior urethral strictures were selected and randomly divided into two groups: bipolar group (n=27) or cold-knife group (n=26). Patients in the bipolar group experienced a shorter operative time compared to the cold-knife group (23.45±7.64 hours vs 33.45±5.45 hours, respectively). The 12-month postoperative Qmax was faster in the bipolar group than in the cold-knife group (15.54±2.78 ml/sec vs 18.25±2.12 ml/sec, respectively). In the bipolar group, the recurrence-free rate was 81.5% at a mean follow-up time of 13.9 months. In the cold-knife group, the recurrence-free rate was 53.8%. The application of bipolar plasma-cutting and plasma-loop electrodes for the management of urethral stricture disease is a safe and reliable method that minimizes the morbidity of urethral stricture resection. The advantages include a lower recurrence rate and shorter operative time compared to the cold-knife technique.

49 CFR 219.605 - Positive drug test results; procedures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CONTROL OF ALCOHOL AND DRUG USE Random Alcohol and Drug Testing Programs § 219.605 Positive drug test results; procedures. (a) [Reserved] (b) Procedures for administrative... 49 Transportation 4 2012-10-01 2012-10-01 false Positive drug test results; procedures. 219.605...

49 CFR 219.605 - Positive drug test results; procedures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CONTROL OF ALCOHOL AND DRUG USE Random Alcohol and Drug Testing Programs § 219.605 Positive drug test results; procedures. (a) [Reserved] (b) Procedures for administrative... 49 Transportation 4 2010-10-01 2010-10-01 false Positive drug test results; procedures. 219.605...

49 CFR 219.605 - Positive drug test results; procedures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CONTROL OF ALCOHOL AND DRUG USE Random Alcohol and Drug Testing Programs § 219.605 Positive drug test results; procedures. (a) [Reserved] (b) Procedures for administrative... 49 Transportation 4 2011-10-01 2011-10-01 false Positive drug test results; procedures. 219.605...

49 CFR 219.605 - Positive drug test results; procedures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CONTROL OF ALCOHOL AND DRUG USE Random Alcohol and Drug Testing Programs § 219.605 Positive drug test results; procedures. (a) [Reserved] (b) Procedures for administrative... 49 Transportation 4 2013-10-01 2013-10-01 false Positive drug test results; procedures. 219.605...