method comparative study: Topics by Science.gov

Sample records for method comparative study

A Study Comparing the Pedagogical Effectiveness of Virtual Worlds and of Classical Methods

DTIC Science & Technology

2014-08-01

Approved for public release; distribution is unlimited. A Study Comparing the Pedagogical Effectiveness of Virtual Worlds and of Classical Methods...ABSTRACT A Study Comparing the Pedagogical Effectiveness of Virtual Worlds and of Classical Methods Report Title This experiment tests whether a virtual... PEDAGOGICAL EFFECTIVENESS OF VIRTUAL WORLDS AND OF TRADITIONAL TRAINING METHODS A Thesis by BENJAMIN PETERS
Comparing DIF Methods for Data with Dual Dependency

ERIC Educational Resources Information Center

Jin, Ying; Kang, Minsoo

2016-01-01

Background: The current study compared four differential item functioning (DIF) methods to examine their performances in terms of accounting for dual dependency (i.e., person and item clustering effects) simultaneously by a simulation study, which is not sufficiently studied under the current DIF literature. The four methods compared are logistic…
Comparative study between EDXRF and ASTM E572 methods using two-way ANOVA

NASA Astrophysics Data System (ADS)

Krummenauer, A.; Veit, H. M.; Zoppas-Ferreira, J.

2018-03-01

Comparison with reference method is one of the necessary requirements for the validation of non-standard methods. This comparison was made using the experiment planning technique with two-way ANOVA. In ANOVA, the results obtained using the EDXRF method, to be validated, were compared with the results obtained using the ASTM E572-13 standard test method. Fisher's tests (F-test) were used to comparative study between of the elements: molybdenum, niobium, copper, nickel, manganese, chromium and vanadium. All F-tests of the elements indicate that the null hypothesis (Ho) has not been rejected. As a result, there is no significant difference between the methods compared. Therefore, according to this study, it is concluded that the EDXRF method was approved in this method comparison requirement.
The Comparative Method of Language Acquisition Research: A Mayan Case Study

ERIC Educational Resources Information Center

Pye, Clifton; Pfeiler, Barbara

2014-01-01

This article demonstrates how the Comparative Method can be applied to cross-linguistic research on language acquisition. The Comparative Method provides a systematic procedure for organizing and interpreting acquisition data from different languages. The Comparative Method controls for cross-linguistic differences at all levels of the grammar and…
Comparing the Principle-Based SBH Maieutic Method to Traditional Case Study Methods of Teaching Media Ethics

ERIC Educational Resources Information Center

Grant, Thomas A.

2012-01-01

This quasi-experimental study at a Northwest university compared two methods of teaching media ethics, a class taught with the principle-based SBH Maieutic Method (n = 25) and a class taught with a traditional case study method (n = 27), with a control group (n = 21) that received no ethics training. Following a 16-week intervention, a one-way…
Methods for comparative evaluation of propulsion system designs for supersonic aircraft

NASA Technical Reports Server (NTRS)

Tyson, R. M.; Mairs, R. Y.; Halferty, F. D., Jr.; Moore, B. E.; Chaloff, D.; Knudsen, A. W.

1976-01-01

The propulsion system comparative evaluation study was conducted to define a rapid, approximate method for evaluating the effects of propulsion system changes for an advanced supersonic cruise airplane, and to verify the approximate method by comparing its mission performance results with those from a more detailed analysis. A table look up computer program was developed to determine nacelle drag increments for a range of parametric nacelle shapes and sizes. Aircraft sensitivities to propulsion parameters were defined. Nacelle shapes, installed weights, and installed performance was determined for four study engines selected from the NASA supersonic cruise aircraft research (SCAR) engine studies program. Both rapid evaluation method (using sensitivities) and traditional preliminary design methods were then used to assess the four engines. The method was found to compare well with the more detailed analyses.
A Comparative Study of Test Data Dimensionality Assessment Procedures Under Nonparametric IRT Models

ERIC Educational Resources Information Center

van Abswoude, Alexandra A. H.; van der Ark, L. Andries; Sijtsma, Klaas

2004-01-01

In this article, an overview of nonparametric item response theory methods for determining the dimensionality of item response data is provided. Four methods were considered: MSP, DETECT, HCA/CCPROX, and DIMTEST. First, the methods were compared theoretically. Second, a simulation study was done to compare the effectiveness of MSP, DETECT, and…
Comparative study of performance of neutral axis tracking based damage detection

NASA Astrophysics Data System (ADS)

Soman, R.; Malinowski, P.; Ostachowicz, W.

2015-07-01

This paper presents a comparative study of a novel SHM technique for damage isolation. The performance of the Neutral Axis (NA) tracking based damage detection strategy is compared to other popularly used vibration based damage detection methods viz. ECOMAC, Mode Shape Curvature Method and Strain Flexibility Index Method. The sensitivity of the novel method is compared under changing ambient temperature conditions and in the presence of measurement noise. Finite Element Analysis (FEA) of the DTU 10 MW Wind Turbine was conducted to compare the local damage identification capability of each method and the results are presented. Under the conditions examined, the proposed method was found to be robust to ambient condition changes and measurement noise. The damage identification in some is either at par with the methods mentioned in the literature or better under the investigated damage scenarios.
TRANSMISSION NETWORK PLANNING METHOD FOR COMPARATIVE STUDIES (JOURNAL VERSION)

EPA Science Inventory

An automated transmission network planning method for comparative studies is presented. This method employs logical steps that may closely parallel those taken in practice by the planning engineers. Use is made of a sensitivity matrix to simulate the engineers' experience in sele...
Instrumental variable methods in comparative safety and effectiveness research.

PubMed

Brookhart, M Alan; Rassen, Jeremy A; Schneeweiss, Sebastian

2010-06-01

Instrumental variable (IV) methods have been proposed as a potential approach to the common problem of uncontrolled confounding in comparative studies of medical interventions, but IV methods are unfamiliar to many researchers. The goal of this article is to provide a non-technical, practical introduction to IV methods for comparative safety and effectiveness research. We outline the principles and basic assumptions necessary for valid IV estimation, discuss how to interpret the results of an IV study, provide a review of instruments that have been used in comparative effectiveness research, and suggest some minimal reporting standards for an IV analysis. Finally, we offer our perspective of the role of IV estimation vis-à-vis more traditional approaches based on statistical modeling of the exposure or outcome. We anticipate that IV methods will be often underpowered for drug safety studies of very rare outcomes, but may be potentially useful in studies of intended effects where uncontrolled confounding may be substantial.
A Comparative Study of Four Methods for the Detection of Nematode Eggs and Large Protozoan Cysts in Mandrill Faecal Material.

PubMed

Pouillevet, Hanae; Dibakou, Serge-Ely; Ngoubangoye, Barthélémy; Poirotte, Clémence; Charpentier, Marie J E

2017-01-01

Coproscopical methods like sedimentation and flotation techniques are widely used in the field for studying simian gastrointestinal parasites. Four parasites of known zoonotic potential were studied in a free-ranging, non-provisioned population of mandrills (Mandrillus sphinx): 2 nematodes (Necatoramericanus/Oesophagostomum sp. complex and Strongyloides sp.) and 2 protozoan species (Balantidium coli and Entamoeba coli). Different coproscopical techniques are available but they are rarely compared to evaluate their efficiency to retrieve parasites. In this study 4 different field-friendly methods were compared. A sedimentation method and 3 different McMaster methods (using sugar, salt, and zinc sulphate solutions) were performed on 47 faecal samples collected from different individuals of both sexes and all ages. First, we show that McMaster flotation methods are appropriate to detect and thus quantify large protozoan cysts. Second, zinc sulphate McMaster flotation allows the retrieval of a higher number of parasite taxa compared to the other 3 methods. This method further shows the highest probability to detect each of the studied parasite taxa. Altogether our results show that zinc sulphate McMaster flotation appears to be the best technique to use when studying nematodes and large protozoa. © 2017 S. Karger AG, Basel.
Isotope ratios of trace elements in samples from human nutrition studies determined by TIMS and ICP-MS: precision and accuracy compared.

PubMed

Turnlund, Judith R; Keyes, William R

2002-09-01

Stable isotopes are used with increasing frequency to trace the metabolic fate of minerals in human nutrition studies. The precision of the analytical methods used must be sufficient to permit reliable measurement of low enrichments and the accuracy should permit comparisons between studies. Two methods most frequently used today are thermal ionization mass spectrometry (TIMS) and inductively coupled plasma mass spectrometry (ICP-MS). This study was conducted to compare the two methods. Multiple natural samples of copper, zinc, molybdenum, and magnesium were analyzed by both methods to compare their internal and external precision. Samples with a range of isotopic enrichments that were collected from human studies or prepared from standards were analyzed to compare their accuracy. TIMS was more precise and accurate than ICP-MS. However, the cost, ease, and speed of analysis were better for ICP-MS. Therefore, for most purposes, ICP-MS is the method of choice, but when the highest degrees of precision and accuracy are required and when enrichments are very low, TIMS is the method of choice.
The Problem With the Placement Study.

ERIC Educational Resources Information Center

Miner, Norris

This study compared the effectiveness and efficiency of two alternative methods for determining the status of graduates of Seminole Community College. The first method involved the identification of graduates, design and mailing of a questionnaire, and analysis of response data, as mandated by the state. The second method compared computer data…
Accuracy of two geocoding methods for geographic information system-based exposure assessment in epidemiological studies.

PubMed

Faure, Elodie; Danjou, Aurélie M N; Clavel-Chapelon, Françoise; Boutron-Ruault, Marie-Christine; Dossus, Laure; Fervers, Béatrice

2017-02-24

Environmental exposure assessment based on Geographic Information Systems (GIS) and study participants' residential proximity to environmental exposure sources relies on the positional accuracy of subjects' residences to avoid misclassification bias. Our study compared the positional accuracy of two automatic geocoding methods to a manual reference method. We geocoded 4,247 address records representing the residential history (1990-2008) of 1,685 women from the French national E3N cohort living in the Rhône-Alpes region. We compared two automatic geocoding methods, a free-online geocoding service (method A) and an in-house geocoder (method B), to a reference layer created by manually relocating addresses from method A (method R). For each automatic geocoding method, positional accuracy levels were compared according to the urban/rural status of addresses and time-periods (1990-2000, 2001-2008), using Chi Square tests. Kappa statistics were performed to assess agreement of positional accuracy of both methods A and B with the reference method, overall, by time-periods and by urban/rural status of addresses. Respectively 81.4% and 84.4% of addresses were geocoded to the exact address (65.1% and 61.4%) or to the street segment (16.3% and 23.0%) with methods A and B. In the reference layer, geocoding accuracy was higher in urban areas compared to rural areas (74.4% vs. 10.5% addresses geocoded to the address or interpolated address level, p < 0.0001); no difference was observed according to the period of residence. Compared to the reference method, median positional errors were 0.0 m (IQR = 0.0-37.2 m) and 26.5 m (8.0-134.8 m), with positional errors <100 m for 82.5% and 71.3% of addresses, for method A and method B respectively. Positional agreement of method A and method B with method R was 'substantial' for both methods, with kappa coefficients of 0.60 and 0.61 for methods A and B, respectively. Our study demonstrates the feasibility of geocoding residential addresses in epidemiological studies not initially recorded for environmental exposure assessment, for both recent addresses and residence locations more than 20 years ago. Accuracy of the two automatic geocoding methods was comparable. The in-house method (B) allowed a better control of the geocoding process and was less time consuming.
The Use of Social Media in Recruitment for Medical Research Studies: A Scoping Review

PubMed Central

2016-01-01

Background Recruiting an adequate number of participants into medical research studies is challenging for many researchers. Over the past 10 years, the use of social media websites has increased in the general population. Consequently, social media websites are a new, powerful method for recruiting participants into such studies. Objective The objective was to answer the following questions: (1) Is the use of social media more effective at research participant recruitment than traditional methods? (2) Does social media recruit a sample of research participants comparable to that recruited via other methods? (3) Is social media more cost-effective at research participant recruitment than traditional methods? Methods Using the MEDLINE, PsycINFO, and EMBASE databases, all medical research studies that used social media and at least one other method for recruitment were identified. These studies were then categorized as either interventional studies or observational studies. For each study, the effectiveness of recruitment, demographic characteristics of the participants, and cost-effectiveness of recruitment using social media were evaluated and compared with that of the other methods used. The social media sites used in recruitment were identified, and if a study stated that the target population was “difficult to reach” as identified by the authors of the study, this was noted. Results Out of 30 studies, 12 found social media to be the most effective recruitment method, 15 did not, and 3 found social media to be equally effective as another recruitment method. Of the 12 studies that found social media to be the best recruitment method, 8 were observational studies while 4 were interventional studies. Of the 15 studies that did not find social media to be the best recruitment method, 7 were interventional studies while 8 were observational studies. In total, 8 studies stated that the target population was “hard-to-reach,” and 6 of these studies found social media to be the most effective recruitment method. Out of 14 studies that reported demographic data for participants, 2 studies found that social media recruited a sample comparable to that recruited via traditional methods and 12 did not. Out of 13 studies that reported cost-effectiveness, 5 studies found social media to be the most cost-effective recruitment method, 7 did not, and 1 study found social media equally cost-effective as compared with other methods. Conclusions Only 12 studies out of 30 found social media to be the most effective recruitment method. There is evidence that social media can be the best recruitment method for hard-to-reach populations and observational studies. With only 30 studies having compared recruitment through social media with other methods, more studies need to be done that report the effectiveness of recruitment for each strategy, demographics of participants recruited, and cost-effectiveness of each method. PMID:27821383
Comparative study on gene set and pathway topology-based enrichment methods.

PubMed

Bayerlová, Michaela; Jung, Klaus; Kramer, Frank; Klemm, Florian; Bleckmann, Annalen; Beißbarth, Tim

2015-10-22

Enrichment analysis is a popular approach to identify pathways or sets of genes which are significantly enriched in the context of differentially expressed genes. The traditional gene set enrichment approach considers a pathway as a simple gene list disregarding any knowledge of gene or protein interactions. In contrast, the new group of so called pathway topology-based methods integrates the topological structure of a pathway into the analysis. We comparatively investigated gene set and pathway topology-based enrichment approaches, considering three gene set and four topological methods. These methods were compared in two extensive simulation studies and on a benchmark of 36 real datasets, providing the same pathway input data for all methods. In the benchmark data analysis both types of methods showed a comparable ability to detect enriched pathways. The first simulation study was conducted with KEGG pathways, which showed considerable gene overlaps between each other. In this study with original KEGG pathways, none of the topology-based methods outperformed the gene set approach. Therefore, a second simulation study was performed on non-overlapping pathways created by unique gene IDs. Here, methods accounting for pathway topology reached higher accuracy than the gene set methods, however their sensitivity was lower. We conducted one of the first comprehensive comparative works on evaluating gene set against pathway topology-based enrichment methods. The topological methods showed better performance in the simulation scenarios with non-overlapping pathways, however, they were not conclusively better in the other scenarios. This suggests that simple gene set approach might be sufficient to detect an enriched pathway under realistic circumstances. Nevertheless, more extensive studies and further benchmark data are needed to systematically evaluate these methods and to assess what gain and cost pathway topology information introduces into enrichment analysis. Both types of methods for enrichment analysis require further improvements in order to deal with the problem of pathway overlaps.
Comparative studies of copy number variation detection methods for next-generation sequencing technologies.

PubMed

Duan, Junbo; Zhang, Ji-Gang; Deng, Hong-Wen; Wang, Yu-Ping

2013-01-01

Copy number variation (CNV) has played an important role in studies of susceptibility or resistance to complex diseases. Traditional methods such as fluorescence in situ hybridization (FISH) and array comparative genomic hybridization (aCGH) suffer from low resolution of genomic regions. Following the emergence of next generation sequencing (NGS) technologies, CNV detection methods based on the short read data have recently been developed. However, due to the relatively young age of the procedures, their performance is not fully understood. To help investigators choose suitable methods to detect CNVs, comparative studies are needed. We compared six publicly available CNV detection methods: CNV-seq, FREEC, readDepth, CNVnator, SegSeq and event-wise testing (EWT). They are evaluated both on simulated and real data with different experiment settings. The receiver operating characteristic (ROC) curve is employed to demonstrate the detection performance in terms of sensitivity and specificity, box plot is employed to compare their performances in terms of breakpoint and copy number estimation, Venn diagram is employed to show the consistency among these methods, and F-score is employed to show the overlapping quality of detected CNVs. The computational demands are also studied. The results of our work provide a comprehensive evaluation on the performances of the selected CNV detection methods, which will help biological investigators choose the best possible method.
The Use of Social Media in Recruitment for Medical Research Studies: A Scoping Review.

PubMed

Topolovec-Vranic, Jane; Natarajan, Karthik

2016-11-07

Recruiting an adequate number of participants into medical research studies is challenging for many researchers. Over the past 10 years, the use of social media websites has increased in the general population. Consequently, social media websites are a new, powerful method for recruiting participants into such studies. The objective was to answer the following questions: (1) Is the use of social media more effective at research participant recruitment than traditional methods? (2) Does social media recruit a sample of research participants comparable to that recruited via other methods? (3) Is social media more cost-effective at research participant recruitment than traditional methods? Using the MEDLINE, PsycINFO, and EMBASE databases, all medical research studies that used social media and at least one other method for recruitment were identified. These studies were then categorized as either interventional studies or observational studies. For each study, the effectiveness of recruitment, demographic characteristics of the participants, and cost-effectiveness of recruitment using social media were evaluated and compared with that of the other methods used. The social media sites used in recruitment were identified, and if a study stated that the target population was "difficult to reach" as identified by the authors of the study, this was noted. Out of 30 studies, 12 found social media to be the most effective recruitment method, 15 did not, and 3 found social media to be equally effective as another recruitment method. Of the 12 studies that found social media to be the best recruitment method, 8 were observational studies while 4 were interventional studies. Of the 15 studies that did not find social media to be the best recruitment method, 7 were interventional studies while 8 were observational studies. In total, 8 studies stated that the target population was "hard-to-reach," and 6 of these studies found social media to be the most effective recruitment method. Out of 14 studies that reported demographic data for participants, 2 studies found that social media recruited a sample comparable to that recruited via traditional methods and 12 did not. Out of 13 studies that reported cost-effectiveness, 5 studies found social media to be the most cost-effective recruitment method, 7 did not, and 1 study found social media equally cost-effective as compared with other methods. Only 12 studies out of 30 found social media to be the most effective recruitment method. There is evidence that social media can be the best recruitment method for hard-to-reach populations and observational studies. With only 30 studies having compared recruitment through social media with other methods, more studies need to be done that report the effectiveness of recruitment for each strategy, demographics of participants recruited, and cost-effectiveness of each method. ©Jane Topolovec-Vranic, Karthik Natarajan. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 07.11.2016.
Instrumental variable methods in comparative safety and effectiveness research†

PubMed Central

Brookhart, M. Alan; Rassen, Jeremy A.; Schneeweiss, Sebastian

2010-01-01

Summary Instrumental variable (IV) methods have been proposed as a potential approach to the common problem of uncontrolled confounding in comparative studies of medical interventions, but IV methods are unfamiliar to many researchers. The goal of this article is to provide a non-technical, practical introduction to IV methods for comparative safety and effectiveness research. We outline the principles and basic assumptions necessary for valid IV estimation, discuss how to interpret the results of an IV study, provide a review of instruments that have been used in comparative effectiveness research, and suggest some minimal reporting standards for an IV analysis. Finally, we offer our perspective of the role of IV estimation vis-à-vis more traditional approaches based on statistical modeling of the exposure or outcome. We anticipate that IV methods will be often underpowered for drug safety studies of very rare outcomes, but may be potentially useful in studies of intended effects where uncontrolled confounding may be substantial. PMID:20354968
Effects of test method and participant musical training on preference ratings of stimuli with different reverberation times.

PubMed

Lawless, Martin S; Vigeant, Michelle C

2017-10-01

Selecting an appropriate listening test design for concert hall research depends on several factors, including listening test method and participant critical-listening experience. Although expert listeners afford more reliable data, their perceptions may not be broadly representative. The present paper contains two studies that examined the validity and reliability of the data obtained from two listening test methods, a successive and a comparative method, and two types of participants, musicians and non-musicians. Participants rated their overall preference of auralizations generated from eight concert hall conditions with a range of reverberation times (0.0-7.2 s). Study 1, with 34 participants, assessed the two methods. The comparative method yielded similar results and reliability as the successive method. Additionally, the comparative method was rated as less difficult and more preferable. For study 2, an additional 37 participants rated the stimuli using the comparative method only. An analysis of variance of the responses from both studies revealed that musicians are better than non-musicians at discerning their preferences across stimuli. This result was confirmed with a k-means clustering analysis on the entire dataset that revealed five preference groups. Four groups exhibited clear preferences to the stimuli, while the fifth group, predominantly comprising non-musicians, demonstrated no clear preference.

Application of wavelet and Fuorier transforms as powerful alternatives for derivative spectrophotometry in analysis of binary mixtures: A comparative study

NASA Astrophysics Data System (ADS)

Hassan, Said A.; Abdel-Gawad, Sherif A.

2018-02-01

Two signal processing methods, namely, Continuous Wavelet Transform (CWT) and the second was Discrete Fourier Transform (DFT) were introduced as alternatives to the classical Derivative Spectrophotometry (DS) in analysis of binary mixtures. To show the advantages of these methods, a comparative study was performed on a binary mixture of Naltrexone (NTX) and Bupropion (BUP). The methods were compared by analyzing laboratory prepared mixtures of the two drugs. By comparing performance of the three methods, it was proved that CWT and DFT methods are more efficient and advantageous in analysis of mixtures with overlapped spectra than DS. The three signal processing methods were adopted for the quantification of NTX and BUP in pure and tablet forms. The adopted methods were validated according to the ICH guideline where accuracy, precision and specificity were found to be within appropriate limits.
Comparing Performance of Methods to Deal with Differential Attrition in Lottery Based Evaluations

ERIC Educational Resources Information Center

Zamarro, Gema; Anderson, Kaitlin; Steele, Jennifer; Miller, Trey

2016-01-01

The purpose of this study is to study the performance of different methods (inverse probability weighting and estimation of informative bounds) to control for differential attrition by comparing the results of different methods using two datasets: an original dataset from Portland Public Schools (PPS) subject to high rates of differential…
Comparing Two Methods for Reducing Variability in Voice Quality Measurements

ERIC Educational Resources Information Center

Kreiman, Jody; Gerratt, Bruce R.

2011-01-01

Purpose: Interrater disagreements in ratings of quality plague the study of voice. This study compared 2 methods for handling this variability. Method: Listeners provided multiple breathiness ratings for 2 sets of pathological voices, one including 20 male and 20 female voices unselected for quality and one including 20 breathy female voices.…
Investigating the Efficacy of Practical Skill Teaching: A Pilot-Study Comparing Three Educational Methods

ERIC Educational Resources Information Center

Maloney, Stephen; Storr, Michael; Paynter, Sophie; Morgan, Prue; Ilic, Dragan

2013-01-01

Effective education of practical skills can alter clinician behaviour, positively influence patient outcomes, and reduce the risk of patient harm. This study compares the efficacy of two innovative practical skill teaching methods, against a traditional teaching method. Year three pre-clinical physiotherapy students consented to participate in a…
Comparative study of signalling methods for high-speed backplane transceiver

NASA Astrophysics Data System (ADS)

Wu, Kejun

2017-11-01

A combined analysis of transient simulation and statistical method is proposed for comparative study of signalling methods applied to high-speed backplane transceivers. This method enables fast and accurate signal-to-noise ratio and symbol error rate estimation of a serial link based on a four-dimension design space, including channel characteristics, noise scenarios, equalisation schemes, and signalling methods. The proposed combined analysis method chooses an efficient sampling size for performance evaluation. A comparative study of non-return-to-zero (NRZ), PAM-4, and four-phase shifted sinusoid symbol (PSS-4) using parameterised behaviour-level simulation shows PAM-4 and PSS-4 has substantial advantages over conventional NRZ in most of the cases. A comparison between PAM-4 and PSS-4 shows PAM-4 gets significant bit error rate degradation when noise level is enhanced.
A comparative study of different aspects of manipulating ratio spectra applied for ternary mixtures: Derivative spectrophotometry versus wavelet transform

NASA Astrophysics Data System (ADS)

Salem, Hesham; Lotfy, Hayam M.; Hassan, Nagiba Y.; El-Zeiny, Mohamed B.; Saleh, Sarah S.

2015-01-01

This work represents a comparative study of different aspects of manipulating ratio spectra, which are: double divisor ratio spectra derivative (DR-DD), area under curve of derivative ratio (DR-AUC) and its novel approach, namely area under the curve correction method (AUCCM) applied for overlapped spectra; successive derivative of ratio spectra (SDR) and continuous wavelet transform (CWT) methods. The proposed methods represent different aspects of manipulating ratio spectra of the ternary mixture of Ofloxacin (OFX), Prednisolone acetate (PA) and Tetryzoline HCl (TZH) combined in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the reported HPLC method, showing no significant difference with respect to accuracy and precision.
A comparative study of different aspects of manipulating ratio spectra applied for ternary mixtures: derivative spectrophotometry versus wavelet transform.

PubMed

Salem, Hesham; Lotfy, Hayam M; Hassan, Nagiba Y; El-Zeiny, Mohamed B; Saleh, Sarah S

2015-01-25

This work represents a comparative study of different aspects of manipulating ratio spectra, which are: double divisor ratio spectra derivative (DR-DD), area under curve of derivative ratio (DR-AUC) and its novel approach, namely area under the curve correction method (AUCCM) applied for overlapped spectra; successive derivative of ratio spectra (SDR) and continuous wavelet transform (CWT) methods. The proposed methods represent different aspects of manipulating ratio spectra of the ternary mixture of Ofloxacin (OFX), Prednisolone acetate (PA) and Tetryzoline HCl (TZH) combined in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the reported HPLC method, showing no significant difference with respect to accuracy and precision. Copyright © 2014 Elsevier B.V. All rights reserved.
A comparative study of three cytotoxicity test methods for nanomaterials using sodium lauryl sulfate.

PubMed

Kwon, Jae-Sung; Kim, Kwang-Mahn; Kim, Kyoung-Nam

2014-10-01

The biocompatibility evaluation of nanomaterials is essential for their medical diagnostic and therapeutic usage, where a cytotoxicity test is the simplest form of biocompatibility evaluation. Three methods have been commonly used in previous studies for the cytotoxicity testing of nanomaterials: trypan blue exclusion, colorimetric assay using water soluble tetrazolium (WST), and imaging under a microscope following calcein AM/ethidium homodimer-1 staining. However, there has yet to be a study to compare each method. Therefore, in this study three methods were compared using the standard reference material of sodium lauryl sulfate (SLS). Each method of the cytotoxicity test was carried out using mouse fibroblasts of L-929 exposed to different concentrations of SLS. Compared to the gold standard trypan blue exclusion test, both colorimetric assay using water soluble tetrazolium (WST) and imaging under microscope with calcein AM/ethidium homodimer-1 staining showed results that were not statistically different. Also, each method exhibited various advantages and disadvantages, which included the need of equipment, time taken for the experiment, and provision of additional information such as cell morphology. Therefore, this study concludes that all three methods of cytotoxicity testing may be valid, though careful consideration will be needed when selecting tests with regard to time, finances, and the amount of information required by the researcher(s).
Woodstove Emission Sampling Methods Comparability Analysis and In-situ Evaluation of New Technology Woodstoves.

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

Simons, Carl A.

1988-06-01

One major objective of this study was to compare several woodstove particulate emission sampling methods under laboratory and in-situ conditions. The laboratory work compared the EPA Method 5H, EPA Method 5G, and OMNI Automated Woodstove Emission Sampler (AWES)/Data LOG'r particulate emission sampling systems. A second major objective of the study was to evaluate the performance of two integral catalytic, two low emission non-catalytic, and two conventional technology woodstoves under in-situ conditions with AWES/Data LOG'r system. The AWES/Data LOG'r and EPA Method 5G sampling systems were also compared in an in-situ test on one of the integral catalytic woodstove models. 7more » figs., 12 tabs.« less
Including mixed methods research in systematic reviews: examples from qualitative syntheses in TB and malaria control.

PubMed

Atkins, Salla; Launiala, Annika; Kagaha, Alexander; Smith, Helen

2012-04-30

Health policy makers now have access to a greater number and variety of systematic reviews to inform different stages in the policy making process, including reviews of qualitative research. The inclusion of mixed methods studies in systematic reviews is increasing, but these studies pose particular challenges to methods of review. This article examines the quality of the reporting of mixed methods and qualitative-only studies. We used two completed systematic reviews to generate a sample of qualitative studies and mixed method studies in order to make an assessment of how the quality of reporting and rigor of qualitative-only studies compares with that of mixed-methods studies. Overall, the reporting of qualitative studies in our sample was consistently better when compared with the reporting of mixed methods studies. We found that mixed methods studies are less likely to provide a description of the research conduct or qualitative data analysis procedures and less likely to be judged credible or provide rich data and thick description compared with standalone qualitative studies. Our time-related analysis shows that for both types of study, papers published since 2003 are more likely to report on the study context, describe analysis procedures, and be judged credible and provide rich data. However, the reporting of other aspects of research conduct (i.e. descriptions of the research question, the sampling strategy, and data collection methods) in mixed methods studies does not appear to have improved over time. Mixed methods research makes an important contribution to health research in general, and could make a more substantial contribution to systematic reviews. Through our careful analysis of the quality of reporting of mixed methods and qualitative-only research, we have identified areas that deserve more attention in the conduct and reporting of mixed methods research.
Comparison of Three Methods of Reducing Test Anxiety: Systematic Desensitization, Implosive Therapy, and Study Counseling

ERIC Educational Resources Information Center

Cornish, Richard D.; Dilley, Josiah S.

1973-01-01

Systematic desensitization, implosive therapy, and study counseling have all been effective in reducing test anxiety. In addition, systematic desensitization has been compared to study counseling for effectiveness. This study compares all three methods and suggests that systematic desentization is more effective than the others, and that implosive…
A Comparative Study on Power Point Presentation and Traditional Lecture Method in Material Understandability, Effectiveness and Attitude

ERIC Educational Resources Information Center

Sewasew, Daniel; Mengestle, Missaye; Abate, Gebeyehu

2015-01-01

The aim of this study was to compare PPT and traditional lecture method in material understandability, effectiveness and attitude among university students. Comparative descriptive survey research design was employed to answer the research questions raised. Four hundred and twenty nine participants were selected randomly using stratified sampling…
An analysis of initial acquisition and maintenance of sight words following picture matching and copy cover, and compare teaching methods.

PubMed

Conley, Colleen M; Derby, K Mark; Roberts-Gwinn, Michelle; Weber, Kimberly P; McLaughlin, T E

2004-01-01

This study compared the copy, cover, and compare method to a picture-word matching method for teaching sight word recognition. Participants were 5 kindergarten students with less than preprimer sight word vocabularies who were enrolled in a public school in the Pacific Northwest. A multielement design was used to evaluate the effects of the two interventions. Outcomes suggested that sight words taught using the copy, cover, and compare method resulted in better maintenance of word recognition when compared to the picture-matching intervention. Benefits to students and the practicality of employing the word-level teaching methods are discussed.
Bayesian data analysis in observational comparative effectiveness research: rationale and examples.

PubMed

Olson, William H; Crivera, Concetta; Ma, Yi-Wen; Panish, Jessica; Mao, Lian; Lynch, Scott M

2013-11-01

Many comparative effectiveness research and patient-centered outcomes research studies will need to be observational for one or both of two reasons: first, randomized trials are expensive and time-consuming; and second, only observational studies can answer some research questions. It is generally recognized that there is a need to increase the scientific validity and efficiency of observational studies. Bayesian methods for the design and analysis of observational studies are scientifically valid and offer many advantages over frequentist methods, including, importantly, the ability to conduct comparative effectiveness research/patient-centered outcomes research more efficiently. Bayesian data analysis is being introduced into outcomes studies that we are conducting. Our purpose here is to describe our view of some of the advantages of Bayesian methods for observational studies and to illustrate both realized and potential advantages by describing studies we are conducting in which various Bayesian methods have been or could be implemented.
Analytical investigation of different mathematical approaches utilizing manipulation of ratio spectra

NASA Astrophysics Data System (ADS)

Osman, Essam Eldin A.

2018-01-01

This work represents a comparative study of different approaches of manipulating ratio spectra, applied on a binary mixture of ciprofloxacin HCl and dexamethasone sodium phosphate co-formulated as ear drops. The proposed new spectrophotometric methods are: ratio difference spectrophotometric method (RDSM), amplitude center method (ACM), first derivative of the ratio spectra (1DD) and mean centering of ratio spectra (MCR). The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitations and sensitivity. The obtained results were statistically compared with those obtained from the reported HPLC method, showing no significant difference with respect to accuracy and precision.
Exploration of Analysis Methods for Diagnostic Imaging Tests: Problems with ROC AUC and Confidence Scores in CT Colonography

PubMed Central

Mallett, Susan; Halligan, Steve; Collins, Gary S.; Altman, Doug G.

2014-01-01

Background Different methods of evaluating diagnostic performance when comparing diagnostic tests may lead to different results. We compared two such approaches, sensitivity and specificity with area under the Receiver Operating Characteristic Curve (ROC AUC) for the evaluation of CT colonography for the detection of polyps, either with or without computer assisted detection. Methods In a multireader multicase study of 10 readers and 107 cases we compared sensitivity and specificity, using radiological reporting of the presence or absence of polyps, to ROC AUC calculated from confidence scores concerning the presence of polyps. Both methods were assessed against a reference standard. Here we focus on five readers, selected to illustrate issues in design and analysis. We compared diagnostic measures within readers, showing that differences in results are due to statistical methods. Results Reader performance varied widely depending on whether sensitivity and specificity or ROC AUC was used. There were problems using confidence scores; in assigning scores to all cases; in use of zero scores when no polyps were identified; the bimodal non-normal distribution of scores; fitting ROC curves due to extrapolation beyond the study data; and the undue influence of a few false positive results. Variation due to use of different ROC methods exceeded differences between test results for ROC AUC. Conclusions The confidence scores recorded in our study violated many assumptions of ROC AUC methods, rendering these methods inappropriate. The problems we identified will apply to other detection studies using confidence scores. We found sensitivity and specificity were a more reliable and clinically appropriate method to compare diagnostic tests. PMID:25353643
A Comparative Study of Two Azimuth Based Non Standard Location Methods

DTIC Science & Technology

2017-03-23

Standard Location Methods Rongsong JIH U.S. Department of State / Arms Control, Verification, and Compliance Bureau, 2201 C Street, NW, Washington...COMPARATIVE STUDY OF TWO AZIMUTH-BASED NON-STANDARD LOCATION METHODS R. Jih Department of State / Arms Control, Verification, and Compliance Bureau...cable. The so-called “Yin Zhong Xian” (“引中线” in Chinese) algorithm, hereafter the YZX method , is an Oriental version of IPB-based procedure. It
A Comparative Study on the Effectiveness of the Computer Assisted Method and the Interactionist Approach to Teaching Geometry Shapes to Young Children

ERIC Educational Resources Information Center

Zaranis, Nicholas; Synodi, Evanthia

2017-01-01

The purpose of this study is to compare and evaluate the effectiveness of computer assisted teaching of geometry shapes and an interactionist approach to teaching geometry in kindergarten versus other more traditional teaching methods. Our research compares the improvement of the children's geometrical competence using two teaching approaches. The…
Enumeration of total aerobic microorganisms in foods by SimPlate Total Plate Count-Color Indicator methods and conventional culture methods: collaborative study.

PubMed

Feldsine, Philip T; Leung, Stephanie C; Lienau, Andrew H; Mui, Linda A; Townsend, David E

2003-01-01

The relative efficacy of the SimPlate Total Plate Count-Color Indicator (TPC-CI) method (SimPlate 35 degrees C) was compared with the AOAC Official Method 966.23 (AOAC 35 degrees C) for enumeration of total aerobic microorganisms in foods. The SimPlate TPC-CI method, incubated at 30 degrees C (SimPlate 30 degrees C), was also compared with the International Organization for Standardization (ISO) 4833 method (ISO 30 degrees C). Six food types were analyzed: ground black pepper, flour, nut meats, frozen hamburger patties, frozen fruits, and fresh vegetables. All foods tested were naturally contaminated. Nineteen laboratories throughout North America and Europe participated in the study. Three method comparisons were conducted. In general, there was <0.3 mean log count difference in recovery among the SimPlate methods and their corresponding reference methods. Mean log counts between the 2 reference methods were also very similar. Repeatability (Sr) and reproducibility (SR) standard deviations were similar among the 3 method comparisons. The SimPlate method (35 degrees C) and the AOAC method were comparable for enumerating total aerobic microorganisms in foods. Similarly, the SimPlate method (30 degrees C) was comparable to the ISO method when samples were prepared and incubated according to the ISO method.
A Comparative Study of Standard-Setting Methods.

ERIC Educational Resources Information Center

Livingston, Samuel A.; Zieky, Michael J.

1989-01-01

The borderline group standard-setting method (BGSM), Nedelsky method (NM), and Angoff method (AM) were compared, using reading scores for 1,948 and mathematics scores for 2,191 sixth through ninth graders. The NM and AM were inconsistent with the BGSM. Passing scores were higher where students were more able. (SLD)

[Comparative study on four kinds of assessment methods of post-marketing safety of Danhong injection].

PubMed

Li, Xuelin; Tang, Jinfa; Meng, Fei; Li, Chunxiao; Xie, Yanming

2011-10-01

To study the adverse reaction of Danhong injection with four kinds of methods, central monitoring method, chart review method, literature study method and spontaneous reporting method, and to compare the differences between them, explore an appropriate method to carry out post-marketing safety evaluation of traditional Chinese medicine injection. Set down the adverse reactions' questionnaire of four kinds of methods, central monitoring method, chart review method, literature study method and collect the information on adverse reactions in a certain period. Danhong injection adverse reaction information from Henan Province spontaneous reporting system was collected with spontaneous reporting method. Carry on data summary and descriptive analysis. Study the adverse reaction of Danhong injection with four methods of central monitoring method, chart review method, literature study method and spontaneous reporting method, the rates of adverse events were 0.993%, 0.336%, 0.515%, 0.067%, respectively. Cyanosis, arrhythmia, hypotension, sweating, erythema, hemorrhage dermatitis, rash, irritability, bleeding gums, toothache, tinnitus, asthma, elevated aminotransferases, constipation, pain are new discovered adverse reactions. The central monitoring method is the appropriate method to carry out post-marketing safety evaluation of traditional Chinese medicine injection, which could objectively reflect the real world of clinical usage.
Comparison of Observational Methods and Their Relation to Ratings of Engagement in Young Children

ERIC Educational Resources Information Center

Wood, Brenna K.; Hojnoski, Robin L.; Laracy, Seth D.; Olson, Christopher L.

2016-01-01

Although, collectively, results of earlier direct observation studies suggest momentary time sampling (MTS) may offer certain technical advantages over whole-interval (WIR) and partial-interval (PIR) recording, no study has compared these methods for measuring engagement in young children in naturalistic environments. This study compared direct…
Comparing strategies to assess multiple behavior change in behavioral intervention studies.

PubMed

Drake, Bettina F; Quintiliani, Lisa M; Sapp, Amy L; Li, Yi; Harley, Amy E; Emmons, Karen M; Sorensen, Glorian

2013-03-01

Alternatives to individual behavior change methods have been proposed, however, little has been done to investigate how these methods compare. To explore four methods that quantify change in multiple risk behaviors targeting four common behaviors. We utilized data from two cluster-randomized, multiple behavior change trials conducted in two settings: small businesses and health centers. Methods used were: (1) summative; (2) z-score; (3) optimal linear combination; and (4) impact score. In the Small Business study, methods 2 and 3 revealed similar outcomes. However, physical activity did not contribute to method 3. In the Health Centers study, similar results were found with each of the methods. Multivitamin intake contributed significantly more to each of the summary measures than other behaviors. Selection of methods to assess multiple behavior change in intervention trials must consider study design, and the targeted population when determining the appropriate method/s to use.
Validation sampling can reduce bias in health care database studies: an illustration using influenza vaccination effectiveness.

PubMed

Nelson, Jennifer Clark; Marsh, Tracey; Lumley, Thomas; Larson, Eric B; Jackson, Lisa A; Jackson, Michael L

2013-08-01

Estimates of treatment effectiveness in epidemiologic studies using large observational health care databases may be biased owing to inaccurate or incomplete information on important confounders. Study methods that collect and incorporate more comprehensive confounder data on a validation cohort may reduce confounding bias. We applied two such methods, namely imputation and reweighting, to Group Health administrative data (full sample) supplemented by more detailed confounder data from the Adult Changes in Thought study (validation sample). We used influenza vaccination effectiveness (with an unexposed comparator group) as an example and evaluated each method's ability to reduce bias using the control time period before influenza circulation. Both methods reduced, but did not completely eliminate, the bias compared with traditional effectiveness estimates that do not use the validation sample confounders. Although these results support the use of validation sampling methods to improve the accuracy of comparative effectiveness findings from health care database studies, they also illustrate that the success of such methods depends on many factors, including the ability to measure important confounders in a representative and large enough validation sample, the comparability of the full sample and validation sample, and the accuracy with which the data can be imputed or reweighted using the additional validation sample information. Copyright © 2013 Elsevier Inc. All rights reserved.
Methods to estimate the between‐study variance and its uncertainty in meta‐analysis†

PubMed Central

Jackson, Dan; Viechtbauer, Wolfgang; Bender, Ralf; Bowden, Jack; Knapp, Guido; Kuss, Oliver; Higgins, Julian PT; Langan, Dean; Salanti, Georgia

2015-01-01

Meta‐analyses are typically used to estimate the overall/mean of an outcome of interest. However, inference about between‐study variability, which is typically modelled using a between‐study variance parameter, is usually an additional aim. The DerSimonian and Laird method, currently widely used by default to estimate the between‐study variance, has been long challenged. Our aim is to identify known methods for estimation of the between‐study variance and its corresponding uncertainty, and to summarise the simulation and empirical evidence that compares them. We identified 16 estimators for the between‐study variance, seven methods to calculate confidence intervals, and several comparative studies. Simulation studies suggest that for both dichotomous and continuous data the estimator proposed by Paule and Mandel and for continuous data the restricted maximum likelihood estimator are better alternatives to estimate the between‐study variance. Based on the scenarios and results presented in the published studies, we recommend the Q‐profile method and the alternative approach based on a ‘generalised Cochran between‐study variance statistic’ to compute corresponding confidence intervals around the resulting estimates. Our recommendations are based on a qualitative evaluation of the existing literature and expert consensus. Evidence‐based recommendations require an extensive simulation study where all methods would be compared under the same scenarios. © 2015 The Authors. Research Synthesis Methods published by John Wiley & Sons Ltd. PMID:26332144
A comparative study of interface reconstruction methods for multi-material ALE simulations

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

Kucharik, Milan; Garimalla, Rao; Schofield, Samuel

2009-01-01

In this paper we compare the performance of different methods for reconstructing interfaces in multi-material compressible flow simulations. The methods compared are a material-order-dependent Volume-of-Fluid (VOF) method, a material-order-independent VOF method based on power diagram partitioning of cells and the Moment-of-Fluid method (MOF). We demonstrate that the MOF method provides the most accurate tracking of interfaces, followed by the VOF method with the right material ordering. The material-order-independent VOF method performs some-what worse than the above two while the solutions with VOF using the wrong material order are considerably worse.
Morbidity and chronic pain following different techniques of caesarean section: A comparative study.

PubMed

Belci, D; Di Renzo, G C; Stark, M; Đurić, J; Zoričić, D; Belci, M; Peteh, L L

2015-01-01

Research examining long-term outcomes after childbirth performed with different techniques of caesarean section have been limited and do not provide information on morbidity and neuropathic pain. The study compares two groups of patients submitted to the 'Traditional' method using Pfannenstiel incision and patients submitted to the 'Misgav Ladach' method ≥ 5 years after the operation. We find better long-term postoperative results in the patients that were treated with the Misgav Ladach method compared with the Traditional method. The results were statistically better regarding the intensity of pain, presence of neuropathic and chronic pain and the level of satisfaction about cosmetic appearance of the scar.
A comparative study of progressive versus successive spectrophotometric resolution techniques applied for pharmaceutical ternary mixtures

NASA Astrophysics Data System (ADS)

Saleh, Sarah S.; Lotfy, Hayam M.; Hassan, Nagiba Y.; Salem, Hesham

2014-11-01

This work represents a comparative study of a novel progressive spectrophotometric resolution technique namely, amplitude center method (ACM), versus the well-established successive spectrophotometric resolution techniques namely; successive derivative subtraction (SDS); successive derivative of ratio spectra (SDR) and mean centering of ratio spectra (MCR). All the proposed spectrophotometric techniques consist of several consecutive steps utilizing ratio and/or derivative spectra. The novel amplitude center method (ACM) can be used for the determination of ternary mixtures using single divisor where the concentrations of the components are determined through progressive manipulation performed on the same ratio spectrum. Those methods were applied for the analysis of the ternary mixture of chloramphenicol (CHL), dexamethasone sodium phosphate (DXM) and tetryzoline hydrochloride (TZH) in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the official BP methods, showing no significant difference with respect to accuracy and precision.
Comparability among four invertebrate sampling methods and two multimetric indexes, Fountain Creek Basin, Colorado, 2010–2012

USGS Publications Warehouse

Bruce, James F.; Roberts, James J.; Zuellig, Robert E.

2018-05-24

The U.S. Geological Survey (USGS), in cooperation with Colorado Springs City Engineering and Colorado Springs Utilities, analyzed previously collected invertebrate data to determine the comparability among four sampling methods and two versions (2010 and 2017) of the Colorado Benthic Macroinvertebrate Multimetric Index (MMI). For this study, annual macroinvertebrate samples were collected concurrently (in space and time) at 15 USGS surface-water gaging stations in the Fountain Creek Basin from 2010 to 2012 using four sampling methods. The USGS monitoring project in the basin uses two of the methods and the Colorado Department of Public Health and Environment recommends the other two. These methods belong to two distinct sample types, one that targets single habitats and one that targets multiple habitats. The study results indicate that there are significant differences in MMI values obtained from the single-habitat and multihabitat sample types but methods from each program within each sample type produced comparable values. This study also determined that MMI values calculated by different versions of the Colorado Benthic Macroinvertebrate MMI are indistinguishable. This indicates that the Colorado Department of Public Health and Environment methods are comparable with the USGS monitoring project methods for single-habitat and multihabitat sample types. This report discusses the direct application of the study results to inform the revision of the existing USGS monitoring project in the Fountain Creek Basin.
Parametric Methods for Dynamic 11C-Phenytoin PET Studies.

PubMed

Mansor, Syahir; Yaqub, Maqsood; Boellaard, Ronald; Froklage, Femke E; de Vries, Anke; Bakker, Esther D M; Voskuyl, Rob A; Eriksson, Jonas; Schwarte, Lothar A; Verbeek, Joost; Windhorst, Albert D; Lammertsma, Adriaan A

2017-03-01

In this study, the performance of various methods for generating quantitative parametric images of dynamic 11 C-phenytoin PET studies was evaluated. Methods: Double-baseline 60-min dynamic 11 C-phenytoin PET studies, including online arterial sampling, were acquired for 6 healthy subjects. Parametric images were generated using Logan plot analysis, a basis function method, and spectral analysis. Parametric distribution volume (V T ) and influx rate ( K 1 ) were compared with those obtained from nonlinear regression analysis of time-activity curves. In addition, global and regional test-retest (TRT) variability was determined for parametric K 1 and V T values. Results: Biases in V T observed with all parametric methods were less than 5%. For K 1 , spectral analysis showed a negative bias of 16%. The mean TRT variabilities of V T and K 1 were less than 10% for all methods. Shortening the scan duration to 45 min provided similar V T and K 1 with comparable TRT performance compared with 60-min data. Conclusion: Among the various parametric methods tested, the basis function method provided parametric V T and K 1 values with the least bias compared with nonlinear regression data and showed TRT variabilities lower than 5%, also for smaller volume-of-interest sizes (i.e., higher noise levels) and shorter scan duration. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.
Website-based PNG image steganography using the modified Vigenere Cipher, least significant bit, and dictionary based compression methods

NASA Astrophysics Data System (ADS)

Rojali, Salman, Afan Galih; George

2017-08-01

Along with the development of information technology in meeting the needs, various adverse actions and difficult to avoid are emerging. One of such action is data theft. Therefore, this study will discuss about cryptography and steganography that aims to overcome these problems. This study will use the Modification Vigenere Cipher, Least Significant Bit and Dictionary Based Compression methods. To determine the performance of study, Peak Signal to Noise Ratio (PSNR) method is used to measure objectively and Mean Opinion Score (MOS) method is used to measure subjectively, also, the performance of this study will be compared to other method such as Spread Spectrum and Pixel Value differencing. After comparing, it can be concluded that this study can provide better performance when compared to other methods (Spread Spectrum and Pixel Value Differencing) and has a range of MSE values (0.0191622-0.05275) and PSNR (60.909 to 65.306) with a hidden file size of 18 kb and has a MOS value range (4.214 to 4.722) or image quality that is approaching very good.
Including mixed methods research in systematic reviews: Examples from qualitative syntheses in TB and malaria control

PubMed Central

2012-01-01

Background Health policy makers now have access to a greater number and variety of systematic reviews to inform different stages in the policy making process, including reviews of qualitative research. The inclusion of mixed methods studies in systematic reviews is increasing, but these studies pose particular challenges to methods of review. This article examines the quality of the reporting of mixed methods and qualitative-only studies. Methods We used two completed systematic reviews to generate a sample of qualitative studies and mixed method studies in order to make an assessment of how the quality of reporting and rigor of qualitative-only studies compares with that of mixed-methods studies. Results Overall, the reporting of qualitative studies in our sample was consistently better when compared with the reporting of mixed methods studies. We found that mixed methods studies are less likely to provide a description of the research conduct or qualitative data analysis procedures and less likely to be judged credible or provide rich data and thick description compared with standalone qualitative studies. Our time-related analysis shows that for both types of study, papers published since 2003 are more likely to report on the study context, describe analysis procedures, and be judged credible and provide rich data. However, the reporting of other aspects of research conduct (i.e. descriptions of the research question, the sampling strategy, and data collection methods) in mixed methods studies does not appear to have improved over time. Conclusions Mixed methods research makes an important contribution to health research in general, and could make a more substantial contribution to systematic reviews. Through our careful analysis of the quality of reporting of mixed methods and qualitative-only research, we have identified areas that deserve more attention in the conduct and reporting of mixed methods research. PMID:22545681
Exploration of analysis methods for diagnostic imaging tests: problems with ROC AUC and confidence scores in CT colonography.

PubMed

Mallett, Susan; Halligan, Steve; Collins, Gary S; Altman, Doug G

2014-01-01

Different methods of evaluating diagnostic performance when comparing diagnostic tests may lead to different results. We compared two such approaches, sensitivity and specificity with area under the Receiver Operating Characteristic Curve (ROC AUC) for the evaluation of CT colonography for the detection of polyps, either with or without computer assisted detection. In a multireader multicase study of 10 readers and 107 cases we compared sensitivity and specificity, using radiological reporting of the presence or absence of polyps, to ROC AUC calculated from confidence scores concerning the presence of polyps. Both methods were assessed against a reference standard. Here we focus on five readers, selected to illustrate issues in design and analysis. We compared diagnostic measures within readers, showing that differences in results are due to statistical methods. Reader performance varied widely depending on whether sensitivity and specificity or ROC AUC was used. There were problems using confidence scores; in assigning scores to all cases; in use of zero scores when no polyps were identified; the bimodal non-normal distribution of scores; fitting ROC curves due to extrapolation beyond the study data; and the undue influence of a few false positive results. Variation due to use of different ROC methods exceeded differences between test results for ROC AUC. The confidence scores recorded in our study violated many assumptions of ROC AUC methods, rendering these methods inappropriate. The problems we identified will apply to other detection studies using confidence scores. We found sensitivity and specificity were a more reliable and clinically appropriate method to compare diagnostic tests.
Frequency of data extraction errors and methods to increase data extraction quality: a methodological review.

PubMed

Mathes, Tim; Klaßen, Pauline; Pieper, Dawid

2017-11-28

Our objective was to assess the frequency of data extraction errors and its potential impact on results in systematic reviews. Furthermore, we evaluated the effect of different extraction methods, reviewer characteristics and reviewer training on error rates and results. We performed a systematic review of methodological literature in PubMed, Cochrane methodological registry, and by manual searches (12/2016). Studies were selected by two reviewers independently. Data were extracted in standardized tables by one reviewer and verified by a second. The analysis included six studies; four studies on extraction error frequency, one study comparing different reviewer extraction methods and two studies comparing different reviewer characteristics. We did not find a study on reviewer training. There was a high rate of extraction errors (up to 50%). Errors often had an influence on effect estimates. Different data extraction methods and reviewer characteristics had moderate effect on extraction error rates and effect estimates. The evidence base for established standards of data extraction seems weak despite the high prevalence of extraction errors. More comparative studies are needed to get deeper insights into the influence of different extraction methods.
Comparison of Video Head Impulse Test (vHIT) Gains Between Two Commercially Available Devices and by Different Gain Analytical Methods.

PubMed

Lee, Sang Hun; Yoo, Myung Hoon; Park, Jun Woo; Kang, Byung Chul; Yang, Chan Joo; Kang, Woo Suk; Ahn, Joong Ho; Chung, Jong Woo; Park, Hong Ju

2018-06-01

To evaluate whether video head impulse test (vHIT) gains are dependent on the measuring device and method of analysis. Prospective study. vHIT was performed in 25 healthy subjects using two devices simultaneously. vHIT gains were compared between these instruments and using five different methods of comparing position and velocity gains during head movement intervals. The two devices produced different vHIT gain results with the same method of analysis. There were also significant differences in the vHIT gains measured using different analytical methods. The gain analytic method that compares the areas under the velocity curve (AUC) of the head and eye movements during head movements showed lower vHIT gains than a method that compared the peak velocities of the head and eye movements. The former method produced the vHIT gain with the smallest standard deviation among the five procedures tested in this study. vHIT gains differ in normal subjects depending on the device and method of analysis used, suggesting that it is advisable for each device to have its own normal values. Gain calculations that compare the AUC of the head and eye movements during the head movements show the smallest variance.
COMPARE : a method for analyzing investment alternatives in industrial wood and bark energy systems

Treesearch

Peter J. Ince

1983-01-01

COMPARE is a FORTRAN computer program resulting from a study to develop methods for comparative economic analysis of alternatives in industrial wood and bark energy systems. COMPARE provides complete guidelines for economic analysis of wood and bark energy systems. As such, COMPARE can be useful to those who have only basic familiarity with investment analysis of wood...
A modified form of conjugate gradient method for unconstrained optimization problems

NASA Astrophysics Data System (ADS)

Ghani, Nur Hamizah Abdul; Rivaie, Mohd.; Mamat, Mustafa

2016-06-01

Conjugate gradient (CG) methods have been recognized as an interesting technique to solve optimization problems, due to the numerical efficiency, simplicity and low memory requirements. In this paper, we propose a new CG method based on the study of Rivaie et al. [7] (Comparative study of conjugate gradient coefficient for unconstrained Optimization, Aus. J. Bas. Appl. Sci. 5(2011) 947-951). Then, we show that our method satisfies sufficient descent condition and converges globally with exact line search. Numerical results show that our proposed method is efficient for given standard test problems, compare to other existing CG methods.
Extraction of polycyclic aromatic hydrocarbons and organochlorine pesticides from soils: a comparison between Soxhlet extraction, microwave-assisted extraction and accelerated solvent extraction techniques.

PubMed

Wang, Wentao; Meng, Bingjun; Lu, Xiaoxia; Liu, Yu; Tao, Shu

2007-10-29

The methods of simultaneous extraction of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) from soils using Soxhlet extraction, microwave-assisted extraction (MAE) and accelerated solvent extraction (ASE) were established, and the extraction efficiencies using the three methods were systemically compared from procedural blank, limits of detection and quantification, method recovery and reproducibility, method chromatogram and other factors. In addition, soils with different total organic carbon contents were used to test the extraction efficiencies of the three methods. The results showed that the values obtained in this study were comparable with the values reported by other studies. In some respects such as method recovery and reproducibility, there were no significant differences among the three methods for the extraction of PAHs and OCPs. In some respects such as procedural blank and limits of detection and quantification, there were significant differences among the three methods. Overall, ASE had the best extraction efficiency compared to MAE and Soxhlet extraction, and the extraction efficiencies of MAE and Soxhlet extraction were comparable to each other depending on the property such as TOC content of the studied soil. Considering other factors such as solvent consumption and extraction time, ASE and MAE are preferable to Soxhlet extraction.
Validation sampling can reduce bias in healthcare database studies: an illustration using influenza vaccination effectiveness

PubMed Central

Nelson, Jennifer C.; Marsh, Tracey; Lumley, Thomas; Larson, Eric B.; Jackson, Lisa A.; Jackson, Michael

2014-01-01

Objective Estimates of treatment effectiveness in epidemiologic studies using large observational health care databases may be biased due to inaccurate or incomplete information on important confounders. Study methods that collect and incorporate more comprehensive confounder data on a validation cohort may reduce confounding bias. Study Design and Setting We applied two such methods, imputation and reweighting, to Group Health administrative data (full sample) supplemented by more detailed confounder data from the Adult Changes in Thought study (validation sample). We used influenza vaccination effectiveness (with an unexposed comparator group) as an example and evaluated each method’s ability to reduce bias using the control time period prior to influenza circulation. Results Both methods reduced, but did not completely eliminate, the bias compared with traditional effectiveness estimates that do not utilize the validation sample confounders. Conclusion Although these results support the use of validation sampling methods to improve the accuracy of comparative effectiveness findings from healthcare database studies, they also illustrate that the success of such methods depends on many factors, including the ability to measure important confounders in a representative and large enough validation sample, the comparability of the full sample and validation sample, and the accuracy with which data can be imputed or reweighted using the additional validation sample information. PMID:23849144
Comparison of safety effect estimates obtained from empirical Bayes before-after study, propensity scores-potential outcomes framework, and regression model with cross-sectional data.

PubMed

Wood, Jonathan S; Donnell, Eric T; Porter, Richard J

2015-02-01

A variety of different study designs and analysis methods have been used to evaluate the performance of traffic safety countermeasures. The most common study designs and methods include observational before-after studies using the empirical Bayes method and cross-sectional studies using regression models. The propensity scores-potential outcomes framework has recently been proposed as an alternative traffic safety countermeasure evaluation method to address the challenges associated with selection biases that can be part of cross-sectional studies. Crash modification factors derived from the application of all three methods have not yet been compared. This paper compares the results of retrospective, observational evaluations of a traffic safety countermeasure using both before-after and cross-sectional study designs. The paper describes the strengths and limitations of each method, focusing primarily on how each addresses site selection bias, which is a common issue in observational safety studies. The Safety Edge paving technique, which seeks to mitigate crashes related to roadway departure events, is the countermeasure used in the present study to compare the alternative evaluation methods. The results indicated that all three methods yielded results that were consistent with each other and with previous research. The empirical Bayes results had the smallest standard errors. It is concluded that the propensity scores with potential outcomes framework is a viable alternative analysis method to the empirical Bayes before-after study. It should be considered whenever a before-after study is not possible or practical. Copyright © 2014 Elsevier Ltd. All rights reserved.

Supplementary search methods were more effective and offered better value than bibliographic database searching: A case study from public health and environmental enhancement.

PubMed

Cooper, Chris; Lovell, Rebecca; Husk, Kerryn; Booth, Andrew; Garside, Ruth

2018-06-01

We undertook a systematic review to evaluate the health benefits of environmental enhancement and conservation activities. We were concerned that a conventional process of study identification, focusing on exhaustive searches of bibliographic databases as the primary search method, would be ineffective, offering limited value. The focus of this study is comparing study identification methods. We compare (1) an approach led by searches of bibliographic databases with (2) an approach led by supplementary search methods. We retrospectively assessed the effectiveness and value of both approaches. Effectiveness was determined by comparing (1) the total number of studies identified and screened and (2) the number of includable studies uniquely identified by each approach. Value was determined by comparing included study quality and by using qualitative sensitivity analysis to explore the contribution of studies to the synthesis. The bibliographic databases approach identified 21 409 studies to screen and 2 included qualitative studies were uniquely identified. Study quality was moderate, and contribution to the synthesis was minimal. The supplementary search approach identified 453 studies to screen and 9 included studies were uniquely identified. Four quantitative studies were poor quality but made a substantive contribution to the synthesis; 5 studies were qualitative: 3 studies were good quality, one was moderate quality, and 1 study was excluded from the synthesis due to poor quality. All 4 included qualitative studies made significant contributions to the synthesis. This case study found value in aligning primary methods of study identification to maximise location of relevant evidence. Copyright © 2017 John Wiley & Sons, Ltd.
A comparative study on the traditional Indian Shodhana and Chinese processing methods for aconite roots by characterization and determination of the major components

PubMed Central

2013-01-01

Background Aconitum is an indispensable entity of the traditional medicine therapy in Ayurveda and Traditional Chinese medicine (TCM), in spite of its known fatal toxicity characteristics. The prolonged use of this drug, irrespective of its known lethal effects, is governed by the practice of effective detoxification processes that have been used for decades. However, the processing methods of Ayurveda and TCM are different, and no comparative study has been carried out to evaluate their differences. The objective of the present study was to carry out comparative chemical profiling of the roots of Aconitum heterophyllum Wall, A. carmichaelii Debx., and A. kusnezoffii Reichb. after application of two detoxification methods used in Ayurveda and one method used in TCM . Results Analysis of the processed samples was carried out by ultra-high performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS). The results obtained in the study demonstrate that all three processing methods used in Ayurveda and TCM effectively extract the diester diterpenoid alkaloids and led to their conversion into monoester diterpenoid alkaloids. The efficiency of the processes in reduction of toxic alkaloid contents can be stated as: Processing with water > Shodhana with cow milk > Shodhana with cow urine. The analysis method was validated as per ICH-Q2R1 guidelines and all the parameters were found to comply with the recommendations stated in the guidelines. Conclusions There have been no reports till date, to compare the processing methods used in Ayurveda with the methods used in TCM for detoxification of aconite roots. Our study demonstrates that, these methods used in both the traditional systems of medicine, efficiently detoxify the aconite roots. Amongst the three selected procedures, the TCM method of decoction with water is the most efficient. Through experimental evidences, we prove the conversion of toxic diester diterpenoid alkaloids to relatively safer monoester diterpenoid alkaloids. Thus, this study demonstrates that comparative study on the traditional experiences accumulated in different medical systems is useful for expanding their respective applications. PMID:24156713
An experimental comparison of various methods of nearfield acoustic holography

DOE PAGES

Chelliah, Kanthasamy; Raman, Ganesh; Muehleisen, Ralph T.

2017-05-19

An experimental comparison of four different methods of nearfield acoustic holography (NAH) is presented in this study for planar acoustic sources. The four NAH methods considered in this study are based on: (1) spatial Fourier transform, (2) equivalent sources model, (3) boundary element methods and (4) statistically optimized NAH. Two dimensional measurements were obtained at different distances in front of a tonal sound source and the NAH methods were used to reconstruct the sound field at the source surface. Reconstructed particle velocity and acoustic pressure fields presented in this study showed that the equivalent sources model based algorithm along withmore » Tikhonov regularization provided the best localization of the sources. Reconstruction errors were found to be smaller for the equivalent sources model based algorithm and the statistically optimized NAH algorithm. Effect of hologram distance on the performance of various algorithms is discussed in detail. The study also compares the computational time required by each algorithm to complete the comparison. Four different regularization parameter choice methods were compared. The L-curve method provided more accurate reconstructions than the generalized cross validation and the Morozov discrepancy principle. Finally, the performance of fixed parameter regularization was comparable to that of the L-curve method.« less
An experimental comparison of various methods of nearfield acoustic holography

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

Chelliah, Kanthasamy; Raman, Ganesh; Muehleisen, Ralph T.

An experimental comparison of four different methods of nearfield acoustic holography (NAH) is presented in this study for planar acoustic sources. The four NAH methods considered in this study are based on: (1) spatial Fourier transform, (2) equivalent sources model, (3) boundary element methods and (4) statistically optimized NAH. Two dimensional measurements were obtained at different distances in front of a tonal sound source and the NAH methods were used to reconstruct the sound field at the source surface. Reconstructed particle velocity and acoustic pressure fields presented in this study showed that the equivalent sources model based algorithm along withmore » Tikhonov regularization provided the best localization of the sources. Reconstruction errors were found to be smaller for the equivalent sources model based algorithm and the statistically optimized NAH algorithm. Effect of hologram distance on the performance of various algorithms is discussed in detail. The study also compares the computational time required by each algorithm to complete the comparison. Four different regularization parameter choice methods were compared. The L-curve method provided more accurate reconstructions than the generalized cross validation and the Morozov discrepancy principle. Finally, the performance of fixed parameter regularization was comparable to that of the L-curve method.« less
UNDERSTANDING AND APPLYING ENVIRONMENTAL RELATIVE MOLDINESS INDEX - ERMI

EPA Science Inventory

This study compared two binary classification methods to evaluate the mold condition in 271 homes of infants, 144 of which later developed symptoms of respiratory illness. A method using on-site visual mold inspection was compared to another method using a quantitative index of ...
A Comparative Study on the Architecture Internet of Things and its’ Implementation method

NASA Astrophysics Data System (ADS)

Xiao, Zhiliang

2017-08-01

With the rapid development of science and technology, Internet-based the Internet of things was born and achieved good results. In order to further build a complete Internet of things system, to achieve the design of the Internet of things, we need to constitute the object of the network structure of the indicators of comparative study, and on this basis, the Internet of things connected to the way and do more in-depth to achieve the unity of the object network architecture and implementation methods. This paper mainly analyzes the two types of Internet of Things system, and makes a brief comparative study of the important indicators, and then introduces the connection method and realization method of Internet of Things based on the concept of Internet of Things and architecture.
[Customer satisfaction study in two roman hospitals: comparison between "cook & serve" and "cook & chill"].

PubMed

Perata, E; Ferrari, P; Tarsitani, G

2005-01-01

We studied patient's satisfaction rate for hospital dishes comparing "cook & chill" method with "cook & serve". As principal instrument we used a comparative questionnaire, anonymous and self-compiled, which is able to evaluate the differences of customer satisfaction's rate between the two methods.
Computerized test versus personal interview as admission methods for graduate nursing studies: A retrospective cohort study.

PubMed

Hazut, Koren; Romem, Pnina; Malkin, Smadar; Livshiz-Riven, Ilana

2016-12-01

The purpose of this study was to compare the predictive validity, economic efficiency, and faculty staff satisfaction of a computerized test versus a personal interview as admission methods for graduate nursing studies. A mixed method study was designed, including cross-sectional and retrospective cohorts, interviews, and cost analysis. One hundred and thirty-four students in the Master of Nursing program participated. The success of students in required core courses was similar in both admission method groups. The personal interview method was found to be a significant predictor of success, with cognitive variables the only significant contributors to the model. Higher satisfaction levels were reported with the computerized test compared with the personal interview method. The cost of the personal interview method, in annual hourly work, was 2.28 times higher than the computerized test. These findings may promote discussion regarding the cost benefit of the personal interview as an admission method for advanced academic studies in healthcare professions. © 2016 John Wiley & Sons Australia, Ltd.
Plant species classification using flower images—A comparative study of local feature representations

PubMed Central

Seeland, Marco; Rzanny, Michael; Alaqraa, Nedal; Wäldchen, Jana; Mäder, Patrick

2017-01-01

Steady improvements of image description methods induced a growing interest in image-based plant species classification, a task vital to the study of biodiversity and ecological sensitivity. Various techniques have been proposed for general object classification over the past years and several of them have already been studied for plant species classification. However, results of these studies are selective in the evaluated steps of a classification pipeline, in the utilized datasets for evaluation, and in the compared baseline methods. No study is available that evaluates the main competing methods for building an image representation on the same datasets allowing for generalized findings regarding flower-based plant species classification. The aim of this paper is to comparatively evaluate methods, method combinations, and their parameters towards classification accuracy. The investigated methods span from detection, extraction, fusion, pooling, to encoding of local features for quantifying shape and color information of flower images. We selected the flower image datasets Oxford Flower 17 and Oxford Flower 102 as well as our own Jena Flower 30 dataset for our experiments. Findings show large differences among the various studied techniques and that their wisely chosen orchestration allows for high accuracies in species classification. We further found that true local feature detectors in combination with advanced encoding methods yield higher classification results at lower computational costs compared to commonly used dense sampling and spatial pooling methods. Color was found to be an indispensable feature for high classification results, especially while preserving spatial correspondence to gray-level features. In result, our study provides a comprehensive overview of competing techniques and the implications of their main parameters for flower-based plant species classification. PMID:28234999
An Analysis of Initial Acquisition and Maintenance of Sight Words Following Picture Matching and Copy, Cover, and Compare Teaching Methods

ERIC Educational Resources Information Center

Conley, Colleen M.; Derby, K. Mark; Roberts-Gwinn, Michelle; Weber, Kimberly P.; McLaughlin, T.F.

2004-01-01

This study compared the copy, cover, and compare method to a picture-word matching method for teaching sight word recognition. Participants were 5 kindergarten students with less than preprimer sight word vocabularies who were enrolled in a public school in the Pacific Northwest. A multielement design was used to evaluate the effects of the two…
Comparing individual preferences for four meditation techniques: Zen, Vipassana (Mindfulness), Qigong, and Mantra.

PubMed

Burke, Adam

2012-01-01

A significant number of studies have been published examining the mind-body effects of meditation and its clinical efficacy. There are very few studies, however, which directly compare different meditation methods with each other to explore potentially distinct mechanisms and effects, and no studies comparing individual preferences for different methods. As preference is seen as an important factor in consumer healthcare decision making, greater understanding of this aspect is needed as meditation becomes a more widely used therapeutic modality. For this reason a pilot study was conducted to compare four meditation techniques for personal preference. A within-subjects comparison design was employed. A convenience sample of 247 undergraduate university students participated in the study. Participants learned two open observing meditation techniques-Vipassana (Mindfulness) and Zen, and two focused attention techniques-Mantra and Qigong Visualization, practicing one method per week. At the end of a six-week training period participants ranked the four meditation methods in order of personal preference. Ranking of subjective preference of meditations practiced. A within subjects comparison revealed that significantly more participants chose Vipassana or Mantra meditation as their preferred techniques compared with Qigong Visualization and Zen. This study provides information on differences in preference for type of meditation. As the benefits of meditation accrue over time, selecting a method that motivates sustained practice is a critical objective if therapeutic effects are to be achieved. Copyright © 2012 Elsevier Inc. All rights reserved.
A Comparative Study on the Effectiveness of Two Song-Teaching Methods: Holistic vs. Phrase-by-Phrase

ERIC Educational Resources Information Center

Persellin, Diane; Bateman, Laura

2009-01-01

The purpose of our study was to compare the effectiveness of two song-teaching methods: holistic and phrase-by-phrase. Thirty-two first-grade children (n = 32) from two music classes in an urban elementary school were taught two folksongs. The first class (n = 16) was taught one song through the phrase-by-phrase method and another song through the…
Comparing the Effect of Thinking Maps Training Package Developed by the Thinking Maps Method on the Reading Performance of Dyslexic Students

ERIC Educational Resources Information Center

Faramarzi, Salar; Moradi, Mohammadreza; Abedi, Ahmad

2018-01-01

The present study aimed to develop the thinking maps training package and compare its training effect with the thinking maps method on the reading performance of second and fifth grade of elementary school male dyslexic students. For this mixed method exploratory study, from among the above mentioned grades' students in Isfahan, 90 students who…
75 FR 14170 - Medical Device Epidemiology Network: Developing Partnership Between the Center for Devices and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-24

... methods for medical device comparative analyses, best practices and best design and analysis methods. II... the performance of medical devices (including comparative effectiveness studies). The centers...
Brain Imaging, Forward Inference, and Theories of Reasoning

PubMed Central

Heit, Evan

2015-01-01

This review focuses on the issue of how neuroimaging studies address theoretical accounts of reasoning, through the lens of the method of forward inference (Henson, 2005, 2006). After theories of deductive and inductive reasoning are briefly presented, the method of forward inference for distinguishing between psychological theories based on brain imaging evidence is critically reviewed. Brain imaging studies of reasoning, comparing deductive and inductive arguments, comparing meaningful versus non-meaningful material, investigating hemispheric localization, and comparing conditional and relational arguments, are assessed in light of the method of forward inference. Finally, conclusions are drawn with regard to future research opportunities. PMID:25620926
Brain imaging, forward inference, and theories of reasoning.

PubMed

Heit, Evan

2014-01-01

This review focuses on the issue of how neuroimaging studies address theoretical accounts of reasoning, through the lens of the method of forward inference (Henson, 2005, 2006). After theories of deductive and inductive reasoning are briefly presented, the method of forward inference for distinguishing between psychological theories based on brain imaging evidence is critically reviewed. Brain imaging studies of reasoning, comparing deductive and inductive arguments, comparing meaningful versus non-meaningful material, investigating hemispheric localization, and comparing conditional and relational arguments, are assessed in light of the method of forward inference. Finally, conclusions are drawn with regard to future research opportunities.
A comparative study of progressive versus successive spectrophotometric resolution techniques applied for pharmaceutical ternary mixtures.

PubMed

Saleh, Sarah S; Lotfy, Hayam M; Hassan, Nagiba Y; Salem, Hesham

2014-11-11

This work represents a comparative study of a novel progressive spectrophotometric resolution technique namely, amplitude center method (ACM), versus the well-established successive spectrophotometric resolution techniques namely; successive derivative subtraction (SDS); successive derivative of ratio spectra (SDR) and mean centering of ratio spectra (MCR). All the proposed spectrophotometric techniques consist of several consecutive steps utilizing ratio and/or derivative spectra. The novel amplitude center method (ACM) can be used for the determination of ternary mixtures using single divisor where the concentrations of the components are determined through progressive manipulation performed on the same ratio spectrum. Those methods were applied for the analysis of the ternary mixture of chloramphenicol (CHL), dexamethasone sodium phosphate (DXM) and tetryzoline hydrochloride (TZH) in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the official BP methods, showing no significant difference with respect to accuracy and precision. Copyright © 2014 Elsevier B.V. All rights reserved.
Comparison of reproducibility of natural head position using two methods.

PubMed

Khan, Abdul Rahim; Rajesh, R N G; Dinesh, M R; Sanjay, N; Girish, K S; Venkataraghavan, Karthik

2012-01-01

Lateral cephalometric radiographs have become virtually indispensable to orthodontists in the treatment of patients. They are important in orthodontic growth analysis, diagnosis, treatment planning, monitoring of therapy and evaluation of final treatment outcome. The purpose of this study was to evaluate and compare the maximum reproducibility with minimum variation of natural head position using two methods, i.e. the mirror method and the fluid level device method. The study included two sets of 40 lateral cephalograms taken using two methods of obtaining natural head position: (1) The mirror method and (2) fluid level device method, with a time interval of 2 months. Inclusion criteria • Subjects were randomly selected aged between 18 to 26 years Exclusion criteria • History of orthodontic treatment • Any history of respiratory tract problem or chronic mouth breathing • Any congenital deformity • History of traumatically-induced deformity • History of myofacial pain syndrome • Any previous history of head and neck surgery. The result showed that both the methods for obtaining natural head position-the mirror method and fluid level device method were comparable, but maximum reproducibility was more with the fluid level device as shown by the Dahlberg's coefficient and Bland-Altman plot. The minimum variance was seen with the fluid level device method as shown by Precision and Pearson correlation. The mirror method and the fluid level device method used for obtaining natural head position were comparable without any significance, and the fluid level device method was more reproducible and showed less variance when compared to mirror method for obtaining natural head position. Fluid level device method was more reproducible and shows less variance when compared to mirror method for obtaining natural head position.
Quantitative comparison of in situ soil CO2 flux measurement methods

Treesearch

Jennifer D. Knoepp; James M. Vose

2002-01-01

Development of reliable regional or global carbon budgets requires accurate measurement of soil CO2 flux. We conducted laboratory and field studies to determine the accuracy and comparability of methods commonly used to measure in situ soil CO2 fluxes. Methods compared included CO2...
Comparing three sampling techniques for estimating fine woody down dead biomass

Treesearch

Robert E. Keane; Kathy Gray

2013-01-01

Designing woody fuel sampling methods that quickly, accurately and efficiently assess biomass at relevant spatial scales requires extensive knowledge of each sampling method's strengths, weaknesses and tradeoffs. In this study, we compared various modifications of three common sampling methods (planar intercept, fixed-area microplot and photoload) for estimating...

DEVELOPMENT OF THE EPA RELATIVE MOLDINESS INDEX© AND ITS RELATIONSHIP TO HEALTH

EPA Science Inventory

This study compared two binary classification methods to evaluate the mold condition in 271 homes of infants, 144 of which later developed symptoms of respiratory illness. A method using on-site visual mold inspection was compared to another method using a quantitative index of ...
Necessary but Insufficient

PubMed Central

2017-01-01

Abstract Cross-national data production in social science research has increased dramatically in recent decades. Assessing the comparability of data is necessary before drawing substantive conclusions that are based on cross-national data. Researchers assessing data comparability typically use either quantitative methods such as multigroup confirmatory factor analysis or qualitative methods such as online probing. Because both methods have complementary strengths and weaknesses, this study applies both multigroup confirmatory factor analysis and online probing in a mixed-methods approach to assess the comparability of constructive patriotism and nationalism, two important concepts in the study of national identity. Previous measurement invariance tests failed to achieve scalar measurement invariance, which prohibits a cross-national comparison of latent means (Davidov 2009). The arrival of the 2013 ISSP Module on National Identity has encouraged a reassessment of both constructs and a push to understand why scalar invariance cannot be achieved. Using the example of constructive patriotism and nationalism, this study demonstrates how the combination of multigroup confirmatory factor analysis and online probing can uncover and explain issues related to cross-national comparability. PMID:28579643
Improved sampling and analysis of images in corneal confocal microscopy.

PubMed

Schaldemose, E L; Fontain, F I; Karlsson, P; Nyengaard, J R

2017-10-01

Corneal confocal microscopy (CCM) is a noninvasive clinical method to analyse and quantify corneal nerve fibres in vivo. Although the CCM technique is in constant progress, there are methodological limitations in terms of sampling of images and objectivity of the nerve quantification. The aim of this study was to present a randomized sampling method of the CCM images and to develop an adjusted area-dependent image analysis. Furthermore, a manual nerve fibre analysis method was compared to a fully automated method. 23 idiopathic small-fibre neuropathy patients were investigated using CCM. Corneal nerve fibre length density (CNFL) and corneal nerve fibre branch density (CNBD) were determined in both a manual and automatic manner. Differences in CNFL and CNBD between (1) the randomized and the most common sampling method, (2) the adjusted and the unadjusted area and (3) the manual and automated quantification method were investigated. The CNFL values were significantly lower when using the randomized sampling method compared to the most common method (p = 0.01). There was not a statistical significant difference in the CNBD values between the randomized and the most common sampling method (p = 0.85). CNFL and CNBD values were increased when using the adjusted area compared to the standard area. Additionally, the study found a significant increase in the CNFL and CNBD values when using the manual method compared to the automatic method (p ≤ 0.001). The study demonstrated a significant difference in the CNFL values between the randomized and common sampling method indicating the importance of clear guidelines for the image sampling. The increase in CNFL and CNBD values when using the adjusted cornea area is not surprising. The observed increases in both CNFL and CNBD values when using the manual method of nerve quantification compared to the automatic method are consistent with earlier findings. This study underlines the importance of improving the analysis of the CCM images in order to obtain more objective corneal nerve fibre measurements. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.
Effects of Environmental Toxicants on Metabolic Activity of Natural Microbial Communities

PubMed Central

Barnhart, Carole L. H.; Vestal, J. Robie

1983-01-01

Two methods of measuring microbial activity were used to study the effects of toxicants on natural microbial communities. The methods were compared for suitability for toxicity testing, sensitivity, and adaptability to field applications. This study included measurements of the incorporation of 14C-labeled acetate into microbial lipids and microbial glucosidase activity. Activities were measured per unit biomass, determined as lipid phosphate. The effects of various organic and inorganic toxicants on various natural microbial communities were studied. Both methods were useful in detecting toxicity, and their comparative sensitivities varied with the system studied. In one system, the methods showed approximately the same sensitivities in testing the effects of metals, but the acetate incorporation method was more sensitive in detecting the toxicity of organic compounds. The incorporation method was used to study the effects of a point source of pollution on the microbiota of a receiving stream. Toxic doses were found to be two orders of magnitude higher in sediments than in water taken from the same site, indicating chelation or adsorption of the toxicant by the sediment. The microbiota taken from below a point source outfall was 2 to 100 times more resistant to the toxicants tested than was that taken from above the outfall. Downstream filtrates in most cases had an inhibitory effect on the natural microbiota taken from above the pollution source. The microbial methods were compared with commonly used bioassay methods, using higher organisms, and were found to be similar in ability to detect comparative toxicities of compounds, but were less sensitive than methods which use standard media because of the influences of environmental factors. PMID:16346432
Application of cetylpyridinium chloride and sodium chloride decontamination method for recovery of Mycobacterium tuberculosis from clinically suspected cases of pulmonary tuberculosis.

PubMed

Shinu, Pottathil; Singh, Varsha; Nair, Anroop; Mehrishi, Priya; Mehta, Sonia; Joshi, Ekta

2013-10-01

The study was designed to compare the efficacy of cetylpyridinium chloride (CPC) and sodium chloride (NaCl) decontamination method with N-acetyl L-Cystine (NALC) and sodium hydroxide (NaOH) decontamination (the reference method) method for the recovery of Mycobacterium tuberculosis (MTB) from clinically suspected cases of pulmonary tuberculosis. To evaluate CPC-NaCl and NALC-NaOH decontamination methods, sputum specimens (n = 796) were studied (culturing on Löwenstein-Jensen medium), and the performances were compared. The CPC-NaCl decontamination method demonstrated a sensitivity, specificity, negative predictive value, and positive predictive value of 97.99%, 87.53%, 70.19%, and 99.32%, respectively, when compared to NALC-NaOH decontamination method. In summary, CPC-NaCl decontamination method effectively detected significantly higher number of MTB cases (n = 208) than NALC-NaOH decontamination method (n = 149) particularly in sputum with scanty bacilli and smear-negative cases, indicating the potential of CPC-NaCl decontamination method to preserve paucibacillary cases more efficient than NALC-NaOH decontamination method. © 2013.
Application of work sampling technique to analyze logging operations.

Treesearch

Edwin S. Miyata; Helmuth M. Steinhilb; Sharon A. Winsauer

1981-01-01

Discusses the advantages and disadvantages of various time study methods for determining efficiency and productivity in logging. The work sampling method is compared with the continuous time-study method. Gives the feasibility, capability, and limitation of the work sampling method.
The Effect of Culture Methods and Serum Supplementation on Developmental Competence of Bovine Embryos Cultured In Vitro

USDA-ARS?s Scientific Manuscript database

The objective of this study was to compare the developmental competence of bovine in vitro fertilized embryos in three different culture methods; microdrop method (50 µl of medium under mineral oil in petri dishes) compared to tube methods (1 ml of medium in tubes) with or without oil overlay, and t...
A Comparative Evaluation of Analytical Methods to Allocate Individual Marks from a Team Mark

ERIC Educational Resources Information Center

Nepal, Kali

2012-01-01

This study presents a comparative evaluation of analytical methods to allocate individual marks from a team mark. Only the methods that use or can be converted into some form of mathematical equations are analysed. Some of these methods focus primarily on the assessment of the quality of teamwork product (product assessment) while the others put…
The Effectiveness of School-Type Classes Compared to the Traditional Lecture/Tutorial Method for Teaching Quantitative Methods to Business Students.

ERIC Educational Resources Information Center

Goldfinch, Judy

1996-01-01

A study compared the effectiveness of two methods (medium-size class instruction and large lectures with tutorial sessions) for teaching mathematics and statistics to first-year business students. Students and teachers overwhelmingly preferred the medium-size class method, which produced higher exam scores but had no significant effect on…
Comparative analysis of image classification methods for automatic diagnosis of ophthalmic images

NASA Astrophysics Data System (ADS)

Wang, Liming; Zhang, Kai; Liu, Xiyang; Long, Erping; Jiang, Jiewei; An, Yingying; Zhang, Jia; Liu, Zhenzhen; Lin, Zhuoling; Li, Xiaoyan; Chen, Jingjing; Cao, Qianzhong; Li, Jing; Wu, Xiaohang; Wang, Dongni; Li, Wangting; Lin, Haotian

2017-01-01

There are many image classification methods, but it remains unclear which methods are most helpful for analyzing and intelligently identifying ophthalmic images. We select representative slit-lamp images which show the complexity of ocular images as research material to compare image classification algorithms for diagnosing ophthalmic diseases. To facilitate this study, some feature extraction algorithms and classifiers are combined to automatic diagnose pediatric cataract with same dataset and then their performance are compared using multiple criteria. This comparative study reveals the general characteristics of the existing methods for automatic identification of ophthalmic images and provides new insights into the strengths and shortcomings of these methods. The relevant methods (local binary pattern +SVMs, wavelet transformation +SVMs) which achieve an average accuracy of 87% and can be adopted in specific situations to aid doctors in preliminarily disease screening. Furthermore, some methods requiring fewer computational resources and less time could be applied in remote places or mobile devices to assist individuals in understanding the condition of their body. In addition, it would be helpful to accelerate the development of innovative approaches and to apply these methods to assist doctors in diagnosing ophthalmic disease.
Comparative Study of Different Methods for the Prediction of Drug-Polymer Solubility.

PubMed

Knopp, Matthias Manne; Tajber, Lidia; Tian, Yiwei; Olesen, Niels Erik; Jones, David S; Kozyra, Agnieszka; Löbmann, Korbinian; Paluch, Krzysztof; Brennan, Claire Marie; Holm, René; Healy, Anne Marie; Andrews, Gavin P; Rades, Thomas

2015-09-08

In this study, a comparison of different methods to predict drug-polymer solubility was carried out on binary systems consisting of five model drugs (paracetamol, chloramphenicol, celecoxib, indomethacin, and felodipine) and polyvinylpyrrolidone/vinyl acetate copolymers (PVP/VA) of different monomer weight ratios. The drug-polymer solubility at 25 °C was predicted using the Flory-Huggins model, from data obtained at elevated temperature using thermal analysis methods based on the recrystallization of a supersaturated amorphous solid dispersion and two variations of the melting point depression method. These predictions were compared with the solubility in the low molecular weight liquid analogues of the PVP/VA copolymer (N-vinylpyrrolidone and vinyl acetate). The predicted solubilities at 25 °C varied considerably depending on the method used. However, the three thermal analysis methods ranked the predicted solubilities in the same order, except for the felodipine-PVP system. Furthermore, the magnitude of the predicted solubilities from the recrystallization method and melting point depression method correlated well with the estimates based on the solubility in the liquid analogues, which suggests that this method can be used as an initial screening tool if a liquid analogue is available. The learnings of this important comparative study provided general guidance for the selection of the most suitable method(s) for the screening of drug-polymer solubility.
Effectiveness of Video Demonstration over Conventional Methods in Teaching Osteology in Anatomy.

PubMed

Viswasom, Angela A; Jobby, Abraham

2017-02-01

Technology and its applications are the most happening things in the world. So, is it in the field of medical education. This study was an evaluation of whether the conventional methods can compete with the test of technology. A comparative study of traditional method of teaching osteology in human anatomy with an innovative visual aided method. The study was conducted on 94 students admitted to MBBS 2014 to 2015 batch of Travancore Medical College. The students were divided into two academically validated groups. They were taught using conventional and video demonstrational techniques in a systematic manner. Post evaluation tests were conducted. Analysis of the mark pattern revealed that the group taught using traditional method scored better when compared to the visual aided method. Feedback analysis showed that, the students were able to identify bony features better with clear visualisation and three dimensional view when taught using the video demonstration method. The students identified visual aided method as the more interesting one for learning which helped them in applying the knowledge gained. In most of the questions asked, the two methods of teaching were found to be comparable on the same scale. As the study ends, we discover that, no new technique can be substituted for time tested techniques of teaching and learning. The ideal method would be incorporating newer multimedia techniques into traditional classes.
Three Advantages of Cross-National Comparative Ethnography--Methodological Reflections from a Study of Migrants and Minority Ethnic Youth in English and Spanish Schools

ERIC Educational Resources Information Center

Jørgensen, Clara Rübner

2015-01-01

This paper discusses the strengths of using ethnographic research methods in cross-national comparative research. It focuses particularly on the potential of applying such methods to the study of migrants and minority ethnic youth in education, where large-scale quantitative studies or single-sited ethnographies are currently dominant. By linking…
Double versus single cervical cerclage for patients with recurrent pregnancy loss: a randomized clinical trial.

PubMed

Zolghadri, Jaleh; Younesi, Masoumeh; Asadi, Nasrin; Khosravi, Dezire; Behdin, Shabnam; Tavana, Zohre; Ghaffarpasand, Fariborz

2014-02-01

To compare the effectiveness of the double cervical cerclage method versus the single method in women with recurrent second-trimester delivery. In this randomized clinical trial, we included 33 singleton pregnancies suffering from recurrent second-trimester pregnancy loss (≥2 consecutive fetal loss during second-trimester or with a history of unsuccessful procedures utilizing the McDonald method), due to cervical incompetence. Patients were randomly assigned to undergo either the classic McDonald method (n = 14) or the double cerclage method (n = 19). The successful pregnancy rate and gestational age at delivery was also compared between the two groups. The two study groups were comparable regarding their baseline characteristics. The successful pregnancy rate did not differ significantly between those who underwent the double cerclage method or the classic McDonald cerclage method (100% vs 85.7%; P = 0.172). In the same way, the preterm delivery rate (<34 weeks of gestation) was comparable between the two study groups (10.5% vs 35.7%; P = 0.106). Those undergoing the double cerclage method had longer gestational duration (37.2 ± 2.6 vs 34.3 ± 3.8 weeks; P = 0.016). The double cervical cerclage method seems to provide better cervical support, as compared with the classic McDonald cerclage method, in those suffering from recurrent pregnancy loss, due to cervical incompetence. © 2013 The Authors. Journal of Obstetrics and Gynaecology Research © 2013 Japan Society of Obstetrics and Gynecology.
Kidney volume measurement methods for clinical studies on autosomal dominant polycystic kidney disease

PubMed Central

Sharma, Kanishka; Caroli, Anna; Quach, Le Van; Petzold, Katja; Bozzetto, Michela; Serra, Andreas L.; Remuzzi, Giuseppe; Remuzzi, Andrea

2017-01-01

Background In autosomal dominant polycystic kidney disease (ADPKD), total kidney volume (TKV) is regarded as an important biomarker of disease progression and different methods are available to assess kidney volume. The purpose of this study was to identify the most efficient kidney volume computation method to be used in clinical studies evaluating the effectiveness of treatments on ADPKD progression. Methods and findings We measured single kidney volume (SKV) on two series of MR and CT images from clinical studies on ADPKD (experimental dataset) by two independent operators (expert and beginner), twice, using all of the available methods: polyline manual tracing (reference method), free-hand manual tracing, semi-automatic tracing, Stereology, Mid-slice and Ellipsoid method. Additionally, the expert operator also measured the kidney length. We compared different methods for reproducibility, accuracy, precision, and time required. In addition, we performed a validation study to evaluate the sensitivity of these methods to detect the between-treatment group difference in TKV change over one year, using MR images from a previous clinical study. Reproducibility was higher on CT than MR for all methods, being highest for manual and semiautomatic contouring methods (planimetry). On MR, planimetry showed highest accuracy and precision, while on CT accuracy and precision of both planimetry and Stereology methods were comparable. Mid-slice and Ellipsoid method, as well as kidney length were fast but provided only a rough estimate of kidney volume. The results of the validation study indicated that planimetry and Stereology allow using an importantly lower number of patients to detect changes in kidney volume induced by drug treatment as compared to other methods. Conclusions Planimetry should be preferred over fast and simplified methods for accurately monitoring ADPKD progression and assessing drug treatment effects. Expert operators, especially on MR images, are required for performing reliable estimation of kidney volume. The use of efficient TKV quantification methods considerably reduces the number of patients to enrol in clinical investigations, making them more feasible and significant. PMID:28558028
Pattern and Process in the Comparative Study of Convergent Evolution.

PubMed

Mahler, D Luke; Weber, Marjorie G; Wagner, Catherine E; Ingram, Travis

2017-08-01

Understanding processes that have shaped broad-scale biodiversity patterns is a fundamental goal in evolutionary biology. The development of phylogenetic comparative methods has yielded a tool kit for analyzing contemporary patterns by explicitly modeling processes of change in the past, providing neontologists tools for asking questions previously accessible only for select taxa via the fossil record or laboratory experimentation. The comparative approach, however, differs operationally from alternative approaches to studying convergence in that, for studies of only extant species, convergence must be inferred using evolutionary process models rather than being directly measured. As a result, investigation of evolutionary pattern and process cannot be decoupled in comparative studies of convergence, even though such a decoupling could in theory guard against adaptationist bias. Assumptions about evolutionary process underlying comparative tools can shape the inference of convergent pattern in sometimes profound ways and can color interpretation of such patterns. We discuss these issues and other limitations common to most phylogenetic comparative approaches and suggest ways that they can be avoided in practice. We conclude by promoting a multipronged approach to studying convergence that integrates comparative methods with complementary tests of evolutionary mechanisms and includes ecological and biogeographical perspectives. Carefully employed, the comparative method remains a powerful tool for enriching our understanding of convergence in macroevolution, especially for investigation of why convergence occurs in some settings but not others.
Qualitative Life-Grids: A Proposed Method for Comparative European Educational Research

ERIC Educational Resources Information Center

Abbas, Andrea; Ashwin, Paul; McLean, Monica

2013-01-01

Drawing upon their large three-year mixed-method study comparing four English university sociology departments, the authors demonstrate the benefits to be gained from concisely recording biographical stories on life-grids. They argue that life-grids have key benefits which are important for comparative European educational research. Some of these…
Comparative methods for the analysis of gene-expression evolution: an example using yeast functional genomic data.

PubMed

Oakley, Todd H; Gu, Zhenglong; Abouheif, Ehab; Patel, Nipam H; Li, Wen-Hsiung

2005-01-01

Understanding the evolution of gene function is a primary challenge of modern evolutionary biology. Despite an expanding database from genomic and developmental studies, we are lacking quantitative methods for analyzing the evolution of some important measures of gene function, such as gene-expression patterns. Here, we introduce phylogenetic comparative methods to compare different models of gene-expression evolution in a maximum-likelihood framework. We find that expression of duplicated genes has evolved according to a nonphylogenetic model, where closely related genes are no more likely than more distantly related genes to share common expression patterns. These results are consistent with previous studies that found rapid evolution of gene expression during the history of yeast. The comparative methods presented here are general enough to test a wide range of evolutionary hypotheses using genomic-scale data from any organism.
The Integration of Linguistic Theory: Internal Reconstruction and the Comparative Method in Descriptive Linguistics.

ERIC Educational Resources Information Center

Bailey, Charles-James N.

The author aims: (1) to show that generative phonology uses essentially the method of internal reconstruction which has previously been employed only in diachronic studies in setting up synchronic underlying phonological representations; (2) to show why synchronic analysis should add the comparative method to its arsenal, together with whatever…
Comparative study of key exchange and authentication methods in application, transport and network level security mechanisms

NASA Astrophysics Data System (ADS)

Fathirad, Iraj; Devlin, John; Jiang, Frank

2012-09-01

The key-exchange and authentication are two crucial elements of any network security mechanism. IPsec, SSL/TLS, PGP and S/MIME are well-known security approaches in providing security service to network, transport and application layers; these protocols use different methods (based on their requirements) to establish keying materials and authenticates key-negotiation and participated parties. This paper studies and compares the authenticated key negotiation methods in mentioned protocols.

Validation of cone-beam computed tomography and magnetic resonance imaging of the porcine spine: a comparative study with multidetector computed tomography and anatomical specimens.

PubMed

de Freitas, Ricardo Miguel Costa; Andrade, Celi Santos; Caldas, José Guilherme Mendes Pereira; Kanas, Alexandre Fligelman; Cabral, Richard Halti; Tsunemi, Miriam Harumi; Rodríguez, Hernán Joel Cervantes; Rabbani, Said Rahnamaye

2015-05-01

New spinal interventions or implants have been tested on ex vivo or in vivo porcine spines, as they are readily available and have been accepted as a comparable model to human cadaver spines. Imaging-guided interventional procedures of the spine are mostly based on fluoroscopy or, still, on multidetector computed tomography (MDCT). Cone-beam computed tomography (CBCT) and magnetic resonance imaging (MRI) are also available methods to guide interventional procedures. Although some MDCT data from porcine spines are available in the literature, validation of the measurements on CBCT and MRI is lacking. To describe and compare the anatomical measurements accomplished with MDCT, CBCT, and MRI of lumbar porcine spines to determine if CBCT and MRI are also useful methods for experimental studies. An experimental descriptive-comparative study. Sixteen anatomical measurements of an individual vertebra from six lumbar porcine spines (n=36 vertebrae) were compared with their MDCT, CBCT, and MRI equivalents. Comparisons were made for the absolute values of the parameters. Similarities were found in all imaging methods. Significant correlation (p<.05) was observed with all variables except those that included cartilaginous tissue from the end plates when the anatomical study was compared with the imaging methods. The CBCT and MRI provided imaging measurements of the lumbar porcine spines that were similar to the anatomical and MDCT data, and they can be useful for specific experimental research studies. Copyright © 2015 Elsevier Inc. All rights reserved.
Hypertext Glosses for Foreign Language Reading Comprehension and Vocabulary Acquisition: Effects of Assessment Methods

ERIC Educational Resources Information Center

Chen, I-Jung

2016-01-01

This study compared how three different gloss modes affected college students' L2 reading comprehension and vocabulary acquisition. The study also compared how results on comprehension and vocabulary acquisition may differ depending on the four assessment methods used. A between-subjects design was employed with three groups of Mandarin-speaking…
An Evaluation of Kernel Equating: Parallel Equating with Classical Methods in the SAT Subject Tests[TM] Program. Research Report. ETS RR-09-06

ERIC Educational Resources Information Center

Grant, Mary C.; Zhang, Lilly; Damiano, Michele

2009-01-01

This study investigated kernel equating methods by comparing these methods to operational equatings for two tests in the SAT Subject Tests[TM] program. GENASYS (ETS, 2007) was used for all equating methods and scaled score kernel equating results were compared to Tucker, Levine observed score, chained linear, and chained equipercentile equating…
Applications of propensity score methods in observational comparative effectiveness and safety research: where have we come and where should we go?

PubMed

Borah, Bijan J; Moriarty, James P; Crown, William H; Doshi, Jalpa A

2014-01-01

Propensity score (PS) methods have proliferated in recent years in observational studies in general and in observational comparative effectiveness research (CER) in particular. PS methods are an important set of tools for estimating treatment effects in observational studies, enabling adjustment for measured confounders in an easy-to-understand and transparent way. This article demonstrates how PS methods have been used to address specific CER questions from 2001 through to 2012 by identifying six impactful studies from this period. This article also discusses areas for improvement, including data infrastructure, and a unified set of guidelines in terms of PS implementation and reporting, which will boost confidence in evidence generated through observational CER using PS methods.
Developing comparative criminology and the case of China: an introduction.

PubMed

Liu, Jianhong

2007-02-01

Although comparative criminology has made significant development during the past decade or so, systematic empirical research has only developed along a few topics. Comparative criminology has never occupied a central position in criminology. This article analyzes the major theoretical and methodological impediments in the development of comparative criminology. It stresses a need to shift methodology from a conventional primary approach that uses the nation as the unit of analysis to an in-depth case study method as a primary methodological approach. The article maintains that case study method can overcome the limitation of its descriptive tradition and become a promising methodological approach for comparative criminology.
Statistical methods for detecting and comparing periodic data and their application to the nycthemeral rhythm of bodily harm: A population based study

PubMed Central

2010-01-01

Background Animals, including humans, exhibit a variety of biological rhythms. This article describes a method for the detection and simultaneous comparison of multiple nycthemeral rhythms. Methods A statistical method for detecting periodic patterns in time-related data via harmonic regression is described. The method is particularly capable of detecting nycthemeral rhythms in medical data. Additionally a method for simultaneously comparing two or more periodic patterns is described, which derives from the analysis of variance (ANOVA). This method statistically confirms or rejects equality of periodic patterns. Mathematical descriptions of the detecting method and the comparing method are displayed. Results Nycthemeral rhythms of incidents of bodily harm in Middle Franconia are analyzed in order to demonstrate both methods. Every day of the week showed a significant nycthemeral rhythm of bodily harm. These seven patterns of the week were compared to each other revealing only two different nycthemeral rhythms, one for Friday and Saturday and one for the other weekdays. PMID:21059197
MicroSEQ® Salmonella spp. Detection Kit Using the Pathatrix® 10-Pooling Salmonella spp. Kit Linked Protocol Method Modification.

PubMed

Wall, Jason; Conrad, Rick; Latham, Kathy; Liu, Eric

2014-03-01

Real-time PCR methods for detecting foodborne pathogens offer the advantages of simplicity and quick time to results compared to traditional culture methods. The addition of a recirculating pooled immunomagnetic separation method prior to real-time PCR analysis increases processing output while reducing both cost and labor. This AOAC Research Institute method modification study validates the MicroSEQ® Salmonella spp. Detection Kit [AOAC Performance Tested Method (PTM) 031001] linked with the Pathatrix® 10-Pooling Salmonella spp. Kit (AOAC PTM 090203C) in diced tomatoes, chocolate, and deli ham. The Pathatrix 10-Pooling protocol represents a method modification of the enrichment portion of the MicroSEQ Salmonella spp. The results of the method modification were compared to standard cultural reference methods for diced tomatoes, chocolate, and deli ham. All three matrixes were analyzed in a paired study design. An additional set of chocolate test portions was analyzed using an alternative enrichment medium in an unpaired study design. For all matrixes tested, there were no statistically significant differences in the number of positive test portions detected by the modified candidate method compared to the appropriate reference method. The MicroSEQ Salmonella spp. protocol linked with the Pathatrix individual or 10-Pooling procedure demonstrated reliability as a rapid, simplified, method for the preparation of samples and subsequent detection of Salmonella in diced tomatoes, chocolate, and deli ham.
Methods in the study of discrete upper hybrid waves

NASA Astrophysics Data System (ADS)

Yoon, P. H.; Ye, S.; Labelle, J.; Weatherwax, A. T.; Menietti, J. D.

2007-11-01

Naturally occurring plasma waves characterized by fine frequency structure or discrete spectrum, detected by satellite, rocket-borne instruments, or ground-based receivers, can be interpreted as eigenmodes excited and trapped in field-aligned density structures. This paper overviews various theoretical methods to study such phenomena for a one-dimensional (1-D) density structure. Among the various methods are parabolic approximation, eikonal matching, eigenfunction matching, and full numerical solution based upon shooting method. Various approaches are compared against the full numerical solution. Among the analytic methods it is found that the eigenfunction matching technique best approximates the actual numerical solution. The analysis is further extended to 2-D geometry. A detailed comparative analysis between the eigenfunction matching and fully numerical methods is carried out for the 2-D case. Although in general the two methods compare favorably, significant differences are also found such that for application to actual observations it is prudent to employ the fully numerical method. Application of the methods developed in the present paper to actual geophysical problems will be given in a companion paper.
Quantifying the quality of medical x-ray images: An evaluation based on normal anatomy for lumbar spine and chest radiography

NASA Astrophysics Data System (ADS)

Tingberg, Anders Martin

Optimisation in diagnostic radiology requires accurate methods for determination of patient absorbed dose and clinical image quality. Simple methods for evaluation of clinical image quality are at present scarce and this project aims at developing such methods. Two methods are used and further developed; fulfillment of image criteria (IC) and visual grading analysis (VGA). Clinical image quality descriptors are defined based on these two methods: image criteria score (ICS) and visual grading analysis score (VGAS), respectively. For both methods the basis is the Image Criteria of the ``European Guidelines on Quality Criteria for Diagnostic Radiographic Images''. Both methods have proved to be useful for evaluation of clinical image quality. The two methods complement each other: IC is an absolute method, which means that the quality of images of different patients and produced with different radiographic techniques can be compared with each other. The separating power of IC is, however, weaker than that of VGA. VGA is the best method for comparing images produced with different radiographic techniques and has strong separating power, but the results are relative, since the quality of an image is compared to the quality of a reference image. The usefulness of the two methods has been verified by comparing the results from both of them with results from a generally accepted method for evaluation of clinical image quality, receiver operating characteristics (ROC). The results of the comparison between the two methods based on visibility of anatomical structures and the method based on detection of pathological structures (free-response forced error) indicate that the former two methods can be used for evaluation of clinical image quality as efficiently as the method based on ROC. More studies are, however, needed for us to be able to draw a general conclusion, including studies of other organs, using other radiographic techniques, etc. The results of the experimental evaluation of clinical image quality are compared with physical quantities calculated with a theoretical model based on a voxel phantom, and correlations are found. The results demonstrate that the computer model can be a useful toot in planning further experimental studies.
Developing Appropriate Methods for Cost-Effectiveness Analysis of Cluster Randomized Trials

PubMed Central

Gomes, Manuel; Ng, Edmond S.-W.; Nixon, Richard; Carpenter, James; Thompson, Simon G.

2012-01-01

Aim. Cost-effectiveness analyses (CEAs) may use data from cluster randomized trials (CRTs), where the unit of randomization is the cluster, not the individual. However, most studies use analytical methods that ignore clustering. This article compares alternative statistical methods for accommodating clustering in CEAs of CRTs. Methods. Our simulation study compared the performance of statistical methods for CEAs of CRTs with 2 treatment arms. The study considered a method that ignored clustering—seemingly unrelated regression (SUR) without a robust standard error (SE)—and 4 methods that recognized clustering—SUR and generalized estimating equations (GEEs), both with robust SE, a “2-stage” nonparametric bootstrap (TSB) with shrinkage correction, and a multilevel model (MLM). The base case assumed CRTs with moderate numbers of balanced clusters (20 per arm) and normally distributed costs. Other scenarios included CRTs with few clusters, imbalanced cluster sizes, and skewed costs. Performance was reported as bias, root mean squared error (rMSE), and confidence interval (CI) coverage for estimating incremental net benefits (INBs). We also compared the methods in a case study. Results. Each method reported low levels of bias. Without the robust SE, SUR gave poor CI coverage (base case: 0.89 v. nominal level: 0.95). The MLM and TSB performed well in each scenario (CI coverage, 0.92–0.95). With few clusters, the GEE and SUR (with robust SE) had coverage below 0.90. In the case study, the mean INBs were similar across all methods, but ignoring clustering underestimated statistical uncertainty and the value of further research. Conclusions. MLMs and the TSB are appropriate analytical methods for CEAs of CRTs with the characteristics described. SUR and GEE are not recommended for studies with few clusters. PMID:22016450
A comparative study on effect of e-learning and instructor-led methods on nurses’ documentation competency

PubMed Central

Abbaszadeh, Abbas; Sabeghi, Hakimeh; Borhani, Fariba; Heydari, Abbas

2011-01-01

BACKGROUND: Accurate recording of the nursing care indicates the care performance and its quality, so that, any failure in documentation can be a reason for inadequate patient care. Therefore, improving nurses’ skills in this field using effective educational methods is of high importance. Since traditional teaching methods are not suitable for communities with rapid knowledge expansion and constant changes, e-learning methods can be a viable alternative. To show the importance of e-learning methods on nurses’ care reporting skills, this study was performed to compare the e-learning methods with the traditional instructor-led methods. METHODS: This was a quasi-experimental study aimed to compare the effect of two teaching methods (e-learning and lecture) on nursing documentation and examine the differences in acquiring competency on documentation between nurses who participated in the e-learning (n = 30) and nurses in a lecture group (n = 31). RESULTS: The results of the present study indicated that statistically there was no significant difference between the two groups. The findings also revealed that statistically there was no significant correlation between the two groups toward demographic variables. However, we believe that due to benefits of e-learning against traditional instructor-led method, and according to their equal effect on nurses’ documentation competency, it can be a qualified substitute for traditional instructor-led method. CONCLUSIONS: E-learning as a student-centered method as well as lecture method equally promote competency of the nurses on documentation. Therefore, e-learning can be used to facilitate the implementation of nursing educational programs. PMID:22224113
A Comparison of the OSHA Modified NIOSH Physical and Chemical Analytical Method (P and CAM) 304 and the Dust Trak Photometric Aerosol Sampler for 0-Chlorobenzylidine Malonitrile

DTIC Science & Technology

2013-04-02

photometric particle counting instrument, DustTrak, to the established OSHA modified NIOSH P&CAM 304 method to determine correlation between the two...study compared the non-specific, rapid photometric particle counting instrument, DustTrak, to the established OSHA modified NIOSH P&CAM 304 method...mask confidence training (27) . This study will compare a direct reading, non-specific photometric particle count instrument (DustTrak TSI Model
An Empirical Comparison of DDF Detection Methods for Understanding the Causes of DIF in Multiple-Choice Items

ERIC Educational Resources Information Center

Suh, Youngsuk; Talley, Anna E.

2015-01-01

This study compared and illustrated four differential distractor functioning (DDF) detection methods for analyzing multiple-choice items. The log-linear approach, two item response theory-model-based approaches with likelihood ratio tests, and the odds ratio approach were compared to examine the congruence among the four DDF detection methods.…
Midstory hardwood species respond differently to chainsaw girdle method and herbicide treatment

Treesearch

Ronald A. Rathfon; Michael R. Saunders

2013-01-01

Foresters in the Central Hardwoods Region commonly fell or girdle interfering trees and apply herbicide to the cut surface when performing intermediate silvicultural treatments. The objective of this study was to compare the use of single and double chainsaw girdle methods in combination with a herbicide treatment and, within the double girdle method, compare herbicide...
A comparison of heuristic and model-based clustering methods for dietary pattern analysis.

PubMed

Greve, Benjamin; Pigeot, Iris; Huybrechts, Inge; Pala, Valeria; Börnhorst, Claudia

2016-02-01

Cluster analysis is widely applied to identify dietary patterns. A new method based on Gaussian mixture models (GMM) seems to be more flexible compared with the commonly applied k-means and Ward's method. In the present paper, these clustering approaches are compared to find the most appropriate one for clustering dietary data. The clustering methods were applied to simulated data sets with different cluster structures to compare their performance knowing the true cluster membership of observations. Furthermore, the three methods were applied to FFQ data assessed in 1791 children participating in the IDEFICS (Identification and Prevention of Dietary- and Lifestyle-Induced Health Effects in Children and Infants) Study to explore their performance in practice. The GMM outperformed the other methods in the simulation study in 72 % up to 100 % of cases, depending on the simulated cluster structure. Comparing the computationally less complex k-means and Ward's methods, the performance of k-means was better in 64-100 % of cases. Applied to real data, all methods identified three similar dietary patterns which may be roughly characterized as a 'non-processed' cluster with a high consumption of fruits, vegetables and wholemeal bread, a 'balanced' cluster with only slight preferences of single foods and a 'junk food' cluster. The simulation study suggests that clustering via GMM should be preferred due to its higher flexibility regarding cluster volume, shape and orientation. The k-means seems to be a good alternative, being easier to use while giving similar results when applied to real data.
Comparative evaluation of ibuprofen/beta-cyclodextrin complexes obtained by supercritical carbon dioxide and other conventional methods.

PubMed

Hussein, Khaled; Türk, Michael; Wahl, Martin A

2007-03-01

The preparation of drug/cyclodextrin complexes is a suitable method to improve the dissolution of poor soluble drugs. The efficacy of the Controlled Particle Deposition (CPD) as a new developed method to prepare these complexes in a single stage process using supercritical carbon dioxide is therefore compared with other conventional methods. Ibuprofen/beta-cyclodextrin complexes were prepared with different techniques and characterized using FTIR-ATR spectroscopy, powder X-ray diffractometry (PXRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). In addition, the influences of the processing technique on the drug content (HPLC) and the dissolution behavior were studied. Employing the CPD-process resulted in a drug content of 2.8+/-0.22 wt.% in the carrier. The material obtained by CPD showed an improved dissolution rate of ibuprofen at pH 5 compared with the pure drug and its physical mixture with beta-cyclodextrin. In addition CPD material displays the highest dissolution (93.5+/- 2.89% after 75 min) compared to material obtained by co-precipitation (61.3 +/-0.52%) or freeze-drying (90.6 +/-2.54%). This study presents the CPD-technique as a well suitable method to prepare a drug/beta-cyclodextrin complex with improved drug dissolution compared to the pure drug and materials obtained by other methods.
Comparing the Effects of Objective Structured Assessment of Technical Skills (OSATS) and Traditional Method on Learning of Students.

PubMed

Mansoorian, Mohammad Reza; Hosseiny, Marzeih Sadat; Khosravan, Shahla; Alami, Ali; Alaviani, Mehri

2015-06-01

Despite the benefits of the objective structured assessment of technical skills (OSATS) and it appropriateness for evaluating clinical abilities of nursing students , few studies are available on the application of this method in nursing education. The purpose of this study was to compare the effect of using OSATS and traditional methods on the students' learning. We also aimed to signify students' views about these two methods and their views about the scores they received in these methods in a medical emergency course. A quasi-experimental study was performed on 45 first semester students in nursing and medical emergencies passing a course on fundamentals of practice. The students were selected by a census method and evaluated by both the OSATS and traditional methods. Data collection was performed using checklists prepared based on the 'text book of nursing procedures checklists' published by Iranian nursing organization and a questionnaire containing learning rate and students' estimation of their received scores. Descriptive statistics as well as paired t-test and independent samples t-test were used in data analysis. The mean of students' score in OSATS was significantly higher than their mean score in traditional method (P = 0.01). Moreover, the mean of self-evaluation score after the traditional method was relatively the same as the score the students received in the exam. However, the mean of self-evaluation score after the OSATS was relatively lower than the scores the students received in the OSATS exam. Most students believed that OSATS can evaluate a wide range of students' knowledge and skills compared to traditional method. Results of this study indicated the better effect of OSATS on learning and its relative superiority in precise assessment of clinical skills compared with the traditional evaluation method. Therefore, we recommend using this method in evaluation of students in practical courses.
A Comparative Meta-Analysis of 5E and Traditional Approaches in Turkey

ERIC Educational Resources Information Center

Anil, Özgür; Batdi, Veli

2015-01-01

The aim of this study is to compare the 5E learning model with traditional learning methods in terms of their effect on students' academic achievement, retention and attitude scores. In this context, the meta-analytic method known as the "analysis of analyses" was used and a review undertaken of the studies and theses (N = 14) executed…
A Comparative Study on Electronic versus Traditional Data Collection in a Special Education Setting

ERIC Educational Resources Information Center

Ruf, Hernan Dennis

2012-01-01

The purpose of the current study was to determine the efficiency of an electronic data collection method compared to a traditional paper-based method in the educational field, in terms of the accuracy of data collected and the time required to do it. In addition, data were collected to assess users' preference and system usability. The study…
Musical Practices and Methods in Music Lessons: A Comparative Study of Estonian and Finnish General Music Education

ERIC Educational Resources Information Center

Sepp, Anu; Ruokonen, Inkeri; Ruismäki, Heikki

2015-01-01

This article reveals the results of a comparative study of Estonian and Finnish general music education. The aim was to find out what music teaching practices and approaches/methods were mostly used, what music education perspectives supported those practices. The data were collected using questionnaires and the results of 107 Estonian and 50…

The Effectiveness of an Individualized Learning Method of Instruction When Compared to the Lecture-Discussion Method. A Research Report of a Graduate Study.

ERIC Educational Resources Information Center

Oen, Urban T.; Sweany, H. Paul

To compare the effectiveness of individualized and lecture-discussion methods with a non-instruction (Control) method in developing turfgrass competencies in 11th and 12th grade students as measured by achievement in a battery of tests, teachers from 29 Michigan schools were randomly placed in three groups and attended workshops where they were…
Using Global Positioning Systems (GPS) and temperature data to generate time-activity classifications for estimating personal exposure in air monitoring studies: an automated method

PubMed Central

2014-01-01

Background Personal exposure studies of air pollution generally use self-reported diaries to capture individuals’ time-activity data. Enhancements in the accuracy, size, memory and battery life of personal Global Positioning Systems (GPS) units have allowed for higher resolution tracking of study participants’ locations. Improved time-activity classifications combined with personal continuous air pollution sampling can improve assessments of location-related air pollution exposures for health studies. Methods Data was collected using a GPS and personal temperature from 54 children with asthma living in Montreal, Canada, who participated in a 10-day personal air pollution exposure study. A method was developed that incorporated personal temperature data and then matched a participant’s position against available spatial data (i.e., road networks) to generate time-activity categories. The diary-based and GPS-generated time-activity categories were compared and combined with continuous personal PM2.5 data to assess the impact of exposure misclassification when using diary-based methods. Results There was good agreement between the automated method and the diary method; however, the automated method (means: outdoors = 5.1%, indoors other =9.8%) estimated less time spent in some locations compared to the diary method (outdoors = 6.7%, indoors other = 14.4%). Agreement statistics (AC1 = 0.778) suggest ‘good’ agreement between methods over all location categories. However, location categories (Outdoors and Transit) where less time is spent show greater disagreement: e.g., mean time “Indoors Other” using the time-activity diary was 14.4% compared to 9.8% using the automated method. While mean daily time “In Transit” was relatively consistent between the methods, the mean daily exposure to PM2.5 while “In Transit” was 15.9 μg/m3 using the automated method compared to 6.8 μg/m3 using the daily diary. Conclusions Mean times spent in different locations as categorized by a GPS-based method were comparable to those from a time-activity diary, but there were differences in estimates of exposure to PM2.5 from the two methods. An automated GPS-based time-activity method will reduce participant burden, potentially providing more accurate and unbiased assessments of location. Combined with continuous air measurements, the higher resolution GPS data could present a different and more accurate picture of personal exposures to air pollution. PMID:24885722
Novel Ultrasound Joint Selection Methods Using a Reduced Joint Number Demonstrate Inflammatory Improvement when Compared to Existing Methods and Disease Activity Score at 28 Joints.

PubMed

Tan, York Kiat; Allen, John C; Lye, Weng Kit; Conaghan, Philip G; D'Agostino, Maria Antonietta; Chew, Li-Ching; Thumboo, Julian

2016-01-01

A pilot study testing novel ultrasound (US) joint-selection methods in rheumatoid arthritis. Responsiveness of novel [individualized US (IUS) and individualized composite US (ICUS)] methods were compared with existing US methods and the Disease Activity Score at 28 joints (DAS28) for 12 patients followed for 3 months. IUS selected up to 7 and 12 most ultrasonographically inflamed joints, while ICUS additionally incorporated clinically symptomatic joints. The existing, IUS, and ICUS methods' standardized response means were -0.39, -1.08, and -1.11, respectively, for 7 joints; -0.49, -1.00, and -1.16, respectively, for 12 joints; and -0.94 for DAS28. Novel methods effectively demonstrate inflammatory improvement when compared with existing methods and DAS28.
Development and validity of a 3-day smartphone assisted 24-hour recall to assess beverage consumption in a Chinese population: a randomized cross-over study.

PubMed

Smith, Lindsey P; Hua, Jenna; Seto, Edmund; Du, Shufa; Zang, Jiajie; Zou, Shurong; Popkin, Barry M; Mendez, Michelle A

2014-01-01

This paper addresses the need for diet assessment methods that capture the rapidly changing beverage consumption patterns in China. The objective of this study was to develop a 3-day smartphone-assisted 24-hour recall to improve the quantification of beverage intake amongst young Chinese adults (n=110) and validate, in a small subset (n=34), the extent to which the written record and smartphone-assisted recalls adequately estimated total fluid intake, using 24-hour urine samples. The smartphone-assisted method showed improved validity compared with the written record-assisted method, when comparing reported total fluid intake to total urine volume. However, participants reported consuming fewer beverages on the smartphone-assisted method compared with the written record-assisted method, primarily due to decreased consumption of traditional zero-energy beverages (i.e. water, tea) in the smartphone-assisted method. It is unclear why participants reported fewer beverages in the smartphone-assisted method than the written record -assisted method. One possibility is that participants found the smartphone method too cumbersome, and responded by decreasing beverage intake. These results suggest that smartphone-assisted 24-hour recalls perform comparably but do not appear to substantially improve beverage quantification compared with the current written record-based approach. In addition, we piloted a beverage screener to identify consumers of episodically consumed SSBs. As expected, a substantially higher proportion of consumers reported consuming SSBs on the beverage screener compared with either recall type, suggesting that a beverage screener may be useful in characterizing consumption of episodically consumed beverages in China's dynamic food and beverage landscape.
Development and validity of a 3-day smartphone-assisted 24-hour recall to assess beverage consumption in a Chinese population: a randomized cross-over study

PubMed Central

Smith, Lindsey P.; Hua, Jenna; Seto, Edmund; Du, Shufa; Zang, Jiajie; Zou, Shurong; Popkin, Barry M.; Mendez, Michelle A.

2014-01-01

This paper addresses the need for diet assessment methods that capture the rapidly changing beverage consumption patterns in China. The objective of this study was to develop a 3-day smartphone-assisted 24-hour recall to improve the quantification of beverage intake amongst young Chinese adults (n=110) and validate, in a small subset (n=34), the extent to which the written record and smartphone-assisted recalls adequately estimated total fluid intake, using 24-hour urine samples. The smartphone-assisted method showed improved validity compared to the written-assisted method, when comparing reported total fluid intake to total urine volume. However, participants reported consuming fewer beverages on the smartphone-assisted method compared to the written-assisted method, primarily due to decreased consumption of traditional zero-energy beverages (i.e. water, tea) in the smartphone-assisted method. It is unclear why participants reported fewer beverages in the smartphone-assisted method than the written-assisted method. One possibility is that participants found the smartphone method too cumbersome, and responded by decreasing beverage intake. These results suggest that smartphone-assisted 24-hour recalls perform comparably but do not appear to substantially improve beverage quantification compared to the current written record based approach. In addition, we piloted a beverage screener to identify consumers of episodically consumed SSBs. As expected, a substantially higher proportion of consumers reported consuming SSBs on the beverage screener compared to either recall type, suggesting that a beverage screener may be useful in characterizing consumption of episodically consumed beverages in China’s dynamic food and beverage landscape. PMID:25516327
Manual tracing versus smartphone application (app) tracing: a comparative study.

PubMed

Sayar, Gülşilay; Kilinc, Delal Dara

2017-11-01

This study aimed to compare the results of conventional manual cephalometric tracing with those acquired with smartphone application cephalometric tracing. The cephalometric radiographs of 55 patients (25 females and 30 males) were traced via the manual and app methods and were subsequently examined with Steiner's analysis. Five skeletal measurements, five dental measurements and two soft tissue measurements were managed based on 21 landmarks. The durations of the performances of the two methods were also compared. SNA (Sella, Nasion, A point angle) and SNB (Sella, Nasion, B point angle) values for the manual method were statistically lower (p < .001) than those for the app method. The ANB value for the manual method was statistically lower than that of app method. L1-NB (°) and upper lip protrusion values for the manual method were statistically higher than those for the app method. Go-GN/SN, U1-NA (°) and U1-NA (mm) values for manual method were statistically lower than those for the app method. No differences between the two methods were found in the L1-NB (mm), occlusal plane to SN, interincisal angle or lower lip protrusion values. Although statistically significant differences were found between the two methods, the cephalometric tracing proceeded faster with the app method than with the manual method.
A comparative study on effect of e-learning and instructor-led methods on nurses' documentation competency.

PubMed

Abbaszadeh, Abbas; Sabeghi, Hakimeh; Borhani, Fariba; Heydari, Abbas

2011-01-01

Accurate recording of the nursing care indicates the care performance and its quality, so that, any failure in documentation can be a reason for inadequate patient care. Therefore, improving nurses' skills in this field using effective educational methods is of high importance. Since traditional teaching methods are not suitable for communities with rapid knowledge expansion and constant changes, e-learning methods can be a viable alternative. To show the importance of e-learning methods on nurses' care reporting skills, this study was performed to compare the e-learning methods with the traditional instructor-led methods. This was a quasi-experimental study aimed to compare the effect of two teaching methods (e-learning and lecture) on nursing documentation and examine the differences in acquiring competency on documentation between nurses who participated in the e-learning (n = 30) and nurses in a lecture group (n = 31). The results of the present study indicated that statistically there was no significant difference between the two groups. The findings also revealed that statistically there was no significant correlation between the two groups toward demographic variables. However, we believe that due to benefits of e-learning against traditional instructor-led method, and according to their equal effect on nurses' documentation competency, it can be a qualified substitute for traditional instructor-led method. E-learning as a student-centered method as well as lecture method equally promote competency of the nurses on documentation. Therefore, e-learning can be used to facilitate the implementation of nursing educational programs.
Revisiting Individual Creativity Assessment: Triangulation in Subjective and Objective Assessment Methods

ERIC Educational Resources Information Center

Park, Namgyoo K.; Chun, Monica Youngshin; Lee, Jinju

2016-01-01

Compared to the significant development of creativity studies, individual creativity research has not reached a meaningful consensus regarding the most valid and reliable method for assessing individual creativity. This study revisited 2 of the most popular methods for assessing individual creativity: subjective and objective methods. This study…
Assessment of optional sediment transport functions via the complex watershed simulation model SWAT

USDA-ARS?s Scientific Manuscript database

The Soil and Water Assessment Tool 2012 (SWAT2012) offers four sediment routing methods as optional alternatives to the default simplified Bagnold method. Previous studies compared only one of these alternative sediment routing methods with the default method. The proposed study evaluated the impac...
A work study of the CAD/CAM method and conventional manual method in the fabrication of spinal orthoses for patients with adolescent idiopathic scoliosis.

PubMed

Wong, M S; Cheng, J C Y; Wong, M W; So, S F

2005-04-01

A study was conducted to compare the CAD/CAM method with the conventional manual method in fabrication of spinal orthoses for patients with adolescent idiopathic scoliosis. Ten subjects were recruited for this study. Efficiency analyses of the two methods were performed from cast filling/ digitization process to completion of cast/image rectification. The dimensional changes of the casts/ models rectified by the two cast rectification methods were also investigated. The results demonstrated that the CAD/CAM method was faster than the conventional manual method in the studied processes. The mean rectification time of the CAD/CAM method was shorter than that of the conventional manual method by 108.3 min (63.5%). This indicated that the CAD/CAM method took about 1/3 of the time of the conventional manual to finish cast rectification. In the comparison of cast/image dimensional differences between the conventional manual method and the CAD/CAM method, five major dimensions in each of the five rectified regions namely the axilla, thoracic, lumbar, abdominal and pelvic regions were involved. There were no significant dimensional differences (p < 0.05) in 19 out of the 25 studied dimensions. This study demonstrated that the CAD/CAM system could save the time in the rectification process and offer a relatively high resemblance in cast rectification as compared with the conventional manual method.
The comparative method of language acquisition research: a Mayan case study.

PubMed

Pye, Clifton; Pfeiler, Barbara

2014-03-01

This article demonstrates how the Comparative Method can be applied to cross-linguistic research on language acquisition. The Comparative Method provides a systematic procedure for organizing and interpreting acquisition data from different languages. The Comparative Method controls for cross-linguistic differences at all levels of the grammar and is especially useful in drawing attention to variation in contexts of use across languages. This article uses the Comparative Method to analyze the acquisition of verb suffixes in two Mayan languages: K'iche' and Yucatec. Mayan status suffixes simultaneously mark distinctions in verb transitivity, verb class, mood, and clause position. Two-year-old children acquiring K'iche' and Yucatec Maya accurately produce the status suffixes on verbs, in marked distinction to the verbal prefixes for aspect and agreement. We find evidence that the contexts of use for the suffixes differentially promote the children's production of cognate status suffixes in K'iche' and Yucatec.
Developing appropriate methods for cost-effectiveness analysis of cluster randomized trials.

PubMed

Gomes, Manuel; Ng, Edmond S-W; Grieve, Richard; Nixon, Richard; Carpenter, James; Thompson, Simon G

2012-01-01

Cost-effectiveness analyses (CEAs) may use data from cluster randomized trials (CRTs), where the unit of randomization is the cluster, not the individual. However, most studies use analytical methods that ignore clustering. This article compares alternative statistical methods for accommodating clustering in CEAs of CRTs. Our simulation study compared the performance of statistical methods for CEAs of CRTs with 2 treatment arms. The study considered a method that ignored clustering--seemingly unrelated regression (SUR) without a robust standard error (SE)--and 4 methods that recognized clustering--SUR and generalized estimating equations (GEEs), both with robust SE, a "2-stage" nonparametric bootstrap (TSB) with shrinkage correction, and a multilevel model (MLM). The base case assumed CRTs with moderate numbers of balanced clusters (20 per arm) and normally distributed costs. Other scenarios included CRTs with few clusters, imbalanced cluster sizes, and skewed costs. Performance was reported as bias, root mean squared error (rMSE), and confidence interval (CI) coverage for estimating incremental net benefits (INBs). We also compared the methods in a case study. Each method reported low levels of bias. Without the robust SE, SUR gave poor CI coverage (base case: 0.89 v. nominal level: 0.95). The MLM and TSB performed well in each scenario (CI coverage, 0.92-0.95). With few clusters, the GEE and SUR (with robust SE) had coverage below 0.90. In the case study, the mean INBs were similar across all methods, but ignoring clustering underestimated statistical uncertainty and the value of further research. MLMs and the TSB are appropriate analytical methods for CEAs of CRTs with the characteristics described. SUR and GEE are not recommended for studies with few clusters.
A Comparative Investigation of the Combined Effects of Pre-Processing, Wavelength Selection, and Regression Methods on Near-Infrared Calibration Model Performance.

PubMed

Wan, Jian; Chen, Yi-Chieh; Morris, A Julian; Thennadil, Suresh N

2017-07-01

Near-infrared (NIR) spectroscopy is being widely used in various fields ranging from pharmaceutics to the food industry for analyzing chemical and physical properties of the substances concerned. Its advantages over other analytical techniques include available physical interpretation of spectral data, nondestructive nature and high speed of measurements, and little or no need for sample preparation. The successful application of NIR spectroscopy relies on three main aspects: pre-processing of spectral data to eliminate nonlinear variations due to temperature, light scattering effects and many others, selection of those wavelengths that contribute useful information, and identification of suitable calibration models using linear/nonlinear regression . Several methods have been developed for each of these three aspects and many comparative studies of different methods exist for an individual aspect or some combinations. However, there is still a lack of comparative studies for the interactions among these three aspects, which can shed light on what role each aspect plays in the calibration and how to combine various methods of each aspect together to obtain the best calibration model. This paper aims to provide such a comparative study based on four benchmark data sets using three typical pre-processing methods, namely, orthogonal signal correction (OSC), extended multiplicative signal correction (EMSC) and optical path-length estimation and correction (OPLEC); two existing wavelength selection methods, namely, stepwise forward selection (SFS) and genetic algorithm optimization combined with partial least squares regression for spectral data (GAPLSSP); four popular regression methods, namely, partial least squares (PLS), least absolute shrinkage and selection operator (LASSO), least squares support vector machine (LS-SVM), and Gaussian process regression (GPR). The comparative study indicates that, in general, pre-processing of spectral data can play a significant role in the calibration while wavelength selection plays a marginal role and the combination of certain pre-processing, wavelength selection, and nonlinear regression methods can achieve superior performance over traditional linear regression-based calibration.
Comparison of four different methods for detection of biofilm formation by uropathogens.

PubMed

Panda, Pragyan Swagatika; Chaudhary, Uma; Dube, Surya K

2016-01-01

Urinary tract infection (UTI) is one of the most common infectious diseases encountered in clinical practice. Emerging resistance of the uropathogens to the antimicrobial agents due to biofilm formation is a matter of concern while treating symptomatic UTI. However, studies comparing different methods for detection of biofilm by uropathogens are scarce. To compare four different methods for detection of biofilm formation by uropathogens. Prospective observational study conducted in a tertiary care hospital. Totally 300 isolates from urinary samples were analyzed for biofilm formation by four methods, that is, tissue culture plate (TCP) method, tube method (TM), Congo Red Agar (CRA) method and modified CRA (MCRA) method. Chi-square test was applied when two or more set of variables were compared. P < 0.05 considered as statistically significant. Considering TCP to be a gold standard method for our study we calculated other statistical parameters. The rate of biofilm detection was 45.6%, 39.3% and 11% each by TCP, TM, CRA and MCRA methods, respectively. The difference between TCP and only CRA/MCRA was significant, but not that between TCP and TM. There was no difference in the rate of biofilm detection between CRA and MCRA in other isolates, but MCRA is superior to CRA for detection of the staphylococcal biofilm formation. TCP method is the ideal method for detection of bacterial biofilm formation by uropathogens. MCRA method is superior only to CRA for detection of staphylococcal biofilm formation.
Confidence-based ensemble for GBM brain tumor segmentation

NASA Astrophysics Data System (ADS)

Huo, Jing; van Rikxoort, Eva M.; Okada, Kazunori; Kim, Hyun J.; Pope, Whitney; Goldin, Jonathan; Brown, Matthew

2011-03-01

It is a challenging task to automatically segment glioblastoma multiforme (GBM) brain tumors on T1w post-contrast isotropic MR images. A semi-automated system using fuzzy connectedness has recently been developed for computing the tumor volume that reduces the cost of manual annotation. In this study, we propose a an ensemble method that combines multiple segmentation results into a final ensemble one. The method is evaluated on a dataset of 20 cases from a multi-center pharmaceutical drug trial and compared to the fuzzy connectedness method. Three individual methods were used in the framework: fuzzy connectedness, GrowCut, and voxel classification. The combination method is a confidence map averaging (CMA) method. The CMA method shows an improved ROC curve compared to the fuzzy connectedness method (p < 0.001). The CMA ensemble result is more robust compared to the three individual methods.
Advantages of using voiced questionnaire and image capture application for data collection from a minority group in rural areas along the Thailand-Myanmar border.

PubMed

Monyarit, Siriporn; Pan-ngum, Wirichada; Lawpoolsri, Saranath; Yimsamran, Surapon; Pongnumkul, Suporn; Kaewkungwal, Jaranit; Singhasivanon, Pratap

2014-01-01

To compare the quality of data collection via electronic data capture (EDC) with voiced questionnaire (QNN) and data image capture features using a tablet versus standard paper-based QNN, to assess the user's perception of using the EDC tool, and to compare user satisfaction with the two methods. Randomised cross-over study. Study sites: This study was conducted in two villages along the Thailand-Myanmar border. This study included 30 community health volunteers (CHVs) and 120 Karen hill tribe villagers. Employing a cross-over study design, the CHVs were allocated randomly to two groups, in which they performed interviews in different sequences using EDC and QNN. Data discrepancies were found between the two data-collection methods, when data from the paper-based and image-capture methods were compared, and when conducting skip pattern questions. More than 90% of the CHVs perceived the EDC to be useful and easy to use. Both interviewers and interviewees were more satisfied with the EDC compared with QNN in terms of format, ease of use, and system speed. The EDC can effectively be used as an alternative method to paper-based QNNs for data collection. It produces more accurate data that can be considered evidence-based.
Recruiting Adolescent Research Participants: In-Person Compared to Social Media Approaches.

PubMed

Moreno, Megan A; Waite, Alan; Pumper, Megan; Colburn, Trina; Holm, Matt; Mendoza, Jason

2017-01-01

Recruiting adolescent participants for research is challenging. The purpose of this study was to compare traditional in-person recruitment methods to social media recruitment. We recruited adolescents aged 14-18 years for a pilot physical activity intervention study, including a wearable physical activity tracking device and a Facebook group. Participants were recruited (a) in person from a local high school and an adolescent medicine clinic and (b) through social media, including Facebook targeted ads, sponsored tweets on Twitter, and a blog post. Data collected included total exposure (i.e., reach), engagement (i.e., interaction), and effectiveness. Effectiveness included screening and enrollment for each recruitment method, as well as time and resources spent on each recruitment method. In-person recruitment reached a total of 297 potential participants of which 37 enrolled in the study. Social media recruitment reached a total of 34,272 potential participants of which 8 enrolled in the study. Social media recruitment methods utilized an average of 1.6 hours of staff time and cost an average of $40.99 per participant enrolled, while in-person recruitment methods utilized an average of 0.75 hours of staff time and cost an average of $19.09 per participant enrolled. Social media recruitment reached more potential participants, but the cost per participant enrolled was higher compared to traditional methods. Studies need to consider benefits and downsides of traditional and social media recruitment methods based on study goals and population.
Comparative study between the hand-wrist method and cervical vertebral maturation method for evaluation skeletal maturity in cleft patients.

PubMed

Manosudprasit, Montian; Wangsrimongkol, Tasanee; Pisek, Poonsak; Chantaramungkorn, Melissa

2013-09-01

To test the measure of agreement between use of the Skeletal Maturation Index (SMI) method of Fishman using hand-wrist radiographs and the Cervical Vertebral Maturation Index (CVMI) method for assessing skeletal maturity of the cleft patients. Hand-wrist and lateral cephalometric radiographs of 60 cleft subjects (35 females and 25 males, age range: 7-16 years) were used. Skeletal age was assessed using an adjustment to the SMI method of Fishman to compare with the CVMI method of Hassel and Farman. Agreement between skeletal age assessed by both methods and the intra- and inter-examiner reliability of both methods were tested by weighted kappa analysis. There was good agreement between the two methods with a kappa value of 0.80 (95% CI = 0.66-0.88, p-value <0.001). Reliability of intra- and inter-examiner of both methods was very good with kappa value ranging from 0.91 to 0.99. The CVMI method can be used as an alternative to the SMI method in skeletal age assessment in cleft patients with the benefit of no need of an additional radiograph and avoiding extra-radiation exposure. Comparing the two methods, the present study found better agreement from peak of adolescence onwards.
Using Global Positioning Systems (GPS) and temperature data to generate time-activity classifications for estimating personal exposure in air monitoring studies: an automated method.

PubMed

Nethery, Elizabeth; Mallach, Gary; Rainham, Daniel; Goldberg, Mark S; Wheeler, Amanda J

2014-05-08

Personal exposure studies of air pollution generally use self-reported diaries to capture individuals' time-activity data. Enhancements in the accuracy, size, memory and battery life of personal Global Positioning Systems (GPS) units have allowed for higher resolution tracking of study participants' locations. Improved time-activity classifications combined with personal continuous air pollution sampling can improve assessments of location-related air pollution exposures for health studies. Data was collected using a GPS and personal temperature from 54 children with asthma living in Montreal, Canada, who participated in a 10-day personal air pollution exposure study. A method was developed that incorporated personal temperature data and then matched a participant's position against available spatial data (i.e., road networks) to generate time-activity categories. The diary-based and GPS-generated time-activity categories were compared and combined with continuous personal PM2.5 data to assess the impact of exposure misclassification when using diary-based methods. There was good agreement between the automated method and the diary method; however, the automated method (means: outdoors = 5.1%, indoors other =9.8%) estimated less time spent in some locations compared to the diary method (outdoors = 6.7%, indoors other = 14.4%). Agreement statistics (AC1 = 0.778) suggest 'good' agreement between methods over all location categories. However, location categories (Outdoors and Transit) where less time is spent show greater disagreement: e.g., mean time "Indoors Other" using the time-activity diary was 14.4% compared to 9.8% using the automated method. While mean daily time "In Transit" was relatively consistent between the methods, the mean daily exposure to PM2.5 while "In Transit" was 15.9 μg/m3 using the automated method compared to 6.8 μg/m3 using the daily diary. Mean times spent in different locations as categorized by a GPS-based method were comparable to those from a time-activity diary, but there were differences in estimates of exposure to PM2.5 from the two methods. An automated GPS-based time-activity method will reduce participant burden, potentially providing more accurate and unbiased assessments of location. Combined with continuous air measurements, the higher resolution GPS data could present a different and more accurate picture of personal exposures to air pollution.
Extending the Fellegi-Sunter probabilistic record linkage method for approximate field comparators.

PubMed

DuVall, Scott L; Kerber, Richard A; Thomas, Alun

2010-02-01

Probabilistic record linkage is a method commonly used to determine whether demographic records refer to the same person. The Fellegi-Sunter method is a probabilistic approach that uses field weights based on log likelihood ratios to determine record similarity. This paper introduces an extension of the Fellegi-Sunter method that incorporates approximate field comparators in the calculation of field weights. The data warehouse of a large academic medical center was used as a case study. The approximate comparator extension was compared with the Fellegi-Sunter method in its ability to find duplicate records previously identified in the data warehouse using different demographic fields and matching cutoffs. The approximate comparator extension misclassified 25% fewer pairs and had a larger Welch's T statistic than the Fellegi-Sunter method for all field sets and matching cutoffs. The accuracy gain provided by the approximate comparator extension grew as less information was provided and as the matching cutoff increased. Given the ubiquity of linkage in both clinical and research settings, the incremental improvement of the extension has the potential to make a considerable impact.

A comparative study of two methods for the orientation of the occlusal plane and the determination of the vertical dimension of occlusion in edentulous patients.

PubMed

Koller, M M; Merlini, L; Spandre, G; Palla, S

1992-07-01

The aim of this study was to compare two methods used to orientate the occlusal plane (OP) and to determine the vertical dimension of occlusion (VDO). In method A the VDO was established by means of the rest position, the minimal speaking distance, and the patient's profile. Method B used a newly developed registration pin assembly. The VDO was registered using a silicone occlusion rim and the swallowing technique. The results were compared to the values of the new dentures. Three standardized lateral radiographs were taken at the VDO obtained with methods A, B, and at that of the final dentures. On each radiograph the orientation of the OP to the Camper plane and the VDO were measured by two investigators independently. The results indicated no statistically significant differences between the mean VDO with method A and B compared with the new dentures (P greater than 0.05). With both methods it was not possible to orientate the OP parallel to the Camper plane. None of the occlusal planes of the new dentures were parallel either. Their OP diverged on average by 7 degrees dorso-caudally. The time spent with method B to orient the OP and to determine the VDO was significantly lower than with method A (17-50 min).
Measuring Link-Resolver Success: Comparing 360 Link with a Local Implementation of WebBridge

ERIC Educational Resources Information Center

Herrera, Gail

2011-01-01

This study reviewed link resolver success comparing 360 Link and a local implementation of WebBridge. Two methods were used: (1) comparing article-level access and (2) examining technical issues for 384 randomly sampled OpenURLs. Google Analytics was used to collect user-generated OpenURLs. For both methods, 360 Link out-performed the local…
A Residual Mass Ballistic Testing Method to Compare Armor Materials or Components (Residual Mass Ballistic Testing Method)

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

Benjamin Langhorst; Thomas M Lillo; Henry S Chu

2014-05-01

A statistics based ballistic test method is presented for use when comparing multiple groups of test articles of unknown relative ballistic perforation resistance. The method is intended to be more efficient than many traditional methods for research and development testing. To establish the validity of the method, it is employed in this study to compare test groups of known relative ballistic performance. Multiple groups of test articles were perforated using consistent projectiles and impact conditions. Test groups were made of rolled homogeneous armor (RHA) plates and differed in thickness. After perforation, each residual projectile was captured behind the target andmore » its mass was measured. The residual masses measured for each test group were analyzed to provide ballistic performance rankings with associated confidence levels. When compared to traditional V50 methods, the residual mass (RM) method was found to require fewer test events and be more tolerant of variations in impact conditions.« less
Comparing effects of fire modeling methods on simulated fire patterns and succession: a case study in the Missouri Ozarks

Treesearch

Jian Yang; Hong S. He; Brian R. Sturtevant; Brian R. Miranda; Eric J. Gustafson

2008-01-01

We compared four fire spread simulation methods (completely random, dynamic percolation. size-based minimum travel time algorithm. and duration-based minimum travel time algorithm) and two fire occurrence simulation methods (Poisson fire frequency model and hierarchical fire frequency model) using a two-way factorial design. We examined these treatment effects on...
A Prospective, Randomized Crossover Study Comparing Direct Inspection by Light Microscopy versus Projected Images for Teaching of Hematopathology to Medical Students

ERIC Educational Resources Information Center

Carlson, Aaron M.; McPhail, Ellen D.; Rodriguez, Vilmarie; Schroeder, Georgene; Wolanskyj, Alexandra P.

2014-01-01

Instruction in hematopathology at Mayo Medical School has evolved from instructor-guided direct inspection under the light microscope (laboratory method), to photomicrographs of glass slides with classroom projection (projection method). These methods have not been compared directly to date. Forty-one second-year medical students participated in…
Comparative Analysis of Western and Domestic Practice of Interactive Method Application in Teaching Social and Political Disciplines at the Universities

ERIC Educational Resources Information Center

Hladka, Halyna

2014-01-01

The comparative analysis of western and domestic practice of introducing active and interactive methods of studies in the process of teaching social science disciplines has been carried out. Features, realities, prospects and limitations in application of interactive methods of teaching in the process of implementing social-political science…
Outcomes of Group Care for Youth: A Review of Comparative Studies

ERIC Educational Resources Information Center

Lee, Bethany R.; Bright, Charlotte L.; Svoboda, Deborah V.; Fakunmoju, Sunday; Barth, Richard P.

2011-01-01

Objective: The purpose of this study was to review empirical evidence of the effects of placement in group care compared to other interventions. Method: Two-group empirical studies were identified and effect sizes for all reported outcomes were calculated. Results: Nineteen two-group studies were found that compared group care with family foster…
Multi-Reader ROC studies with Split-Plot Designs: A Comparison of Statistical Methods

PubMed Central

Obuchowski, Nancy A.; Gallas, Brandon D.; Hillis, Stephen L.

2012-01-01

Rationale and Objectives Multi-reader imaging trials often use a factorial design, where study patients undergo testing with all imaging modalities and readers interpret the results of all tests for all patients. A drawback of the design is the large number of interpretations required of each reader. Split-plot designs have been proposed as an alternative, in which one or a subset of readers interprets all images of a sample of patients, while other readers interpret the images of other samples of patients. In this paper we compare three methods of analysis for the split-plot design. Materials and Methods Three statistical methods are presented: Obuchowski-Rockette method modified for the split-plot design, a newly proposed marginal-mean ANOVA approach, and an extension of the three-sample U-statistic method. A simulation study using the Roe-Metz model was performed to compare the type I error rate, power and confidence interval coverage of the three test statistics. Results The type I error rates for all three methods are close to the nominal level but tend to be slightly conservative. The statistical power is nearly identical for the three methods. The coverage of 95% CIs fall close to the nominal coverage for small and large sample sizes. Conclusions The split-plot MRMC study design can be statistically efficient compared with the factorial design, reducing the number of interpretations required per reader. Three methods of analysis, shown to have nominal type I error rate, similar power, and nominal CI coverage, are available for this study design. PMID:23122570
Operational impact of using a vanadate oxidase method for direct bilirubin measurements at an academic medical center clinical laboratory.

PubMed

Dhungana, Neha; Morris, Cory; Krasowski, Matthew D

2017-08-01

The aim of this study was to compare the operational impact of using vanadate oxidase versus diazo direct bilirubin assays for an academic medical center patient population. Retrospective study was done over an approximately 3.5 year period. The main automated chemistry instrumentation was a Roche Diagnostics cobas 8000 line. The Roche Direct Bilirubin assay was compared to Diazyme Laboratories Direct Bilirubin Assay and Randox Laboratories Direct Bilirubin assay using manufacturer's guidelines for hemolysis index, lipemia index, and analytical measurement range (AMR). Retrospective data was analyzed for 47,333 serum/plasma specimens that had clinical orders for direct bilirubin. A total of 5943 specimens (12.6%) exceeded the hemolysis index limit for the Roche method compared to only 0.2% and 0.05% of specimens for the Diazyme and Randox methods, respectively. The impact was particularly large on patients less than 2 years old, for which 51.3% of specimens exceeded the hemolysis index for the Roche method. A total of 1671 specimens (3.5%) exceeded the lipemia index limit for the Roche method compared to less than 0.1% for the Randox method. Lastly, 988 (2.1%) of specimens had direct bilirubin concentrations exceeding the upper AMR limit of 10 mg/dL [171 µmol/L] for the Roche assay compared to less than 1% of specimens for the vanadate oxidase methods. Vanadate oxidase direct bilirubin methods offer advantages over diazo methods in terms of less interference by hemolysis and lipemia, as well as wider AMR. The advantages are particularly evident for neonatal and infant populations.
A comparative study of cultural methods for the detection of Salmonella in feed and feed ingredients

PubMed Central

Koyuncu, Sevinc; Haggblom, Per

2009-01-01

Background Animal feed as a source of infection to food producing animals is much debated. In order to increase our present knowledge about possible feed transmission it is important to know that the present isolation methods for Salmonella are reliable also for feed materials. In a comparative study the ability of the standard method used for isolation of Salmonella in feed in the Nordic countries, the NMKL71 method (Nordic Committee on Food Analysis) was compared to the Modified Semisolid Rappaport Vassiliadis method (MSRV) and the international standard method (EN ISO 6579:2002). Five different feed materials were investigated, namely wheat grain, soybean meal, rape seed meal, palm kernel meal, pellets of pig feed and also scrapings from a feed mill elevator. Four different levels of the Salmonella serotypes S. Typhimurium, S. Cubana and S. Yoruba were added to each feed material, respectively. For all methods pre-enrichment in Buffered Peptone Water (BPW) were carried out followed by enrichments in the different selective media and finally plating on selective agar media. Results The results obtained with all three methods showed no differences in detection levels, with an accuracy and sensitivity of 65% and 56%, respectively. However, Müller-Kauffmann tetrathionate-novobiocin broth (MKTTn), performed less well due to many false-negative results on Brilliant Green agar (BGA) plates. Compared to other feed materials palm kernel meal showed a higher detection level with all serotypes and methods tested. Conclusion The results of this study showed that the accuracy, sensitivity and specificity of the investigated cultural methods were equivalent. However, the detection levels for different feed and feed ingredients varied considerably. PMID:19192298
Comparative study on the welded structure fatigue strength assessment method

NASA Astrophysics Data System (ADS)

Hu, Tao

2018-04-01

Due to the welding structure is widely applied in various industries, especially the pressure container, motorcycle, automobile, aviation, ship industry, such as large crane steel structure, so for welded structure fatigue strength evaluation is particularly important. For welded structure fatigue strength evaluation method mainly has four kinds of, the more from the use of two kinds of welded structure fatigue strength evaluation method, namely the nominal stress method and the hot spot stress evaluation method, comparing from its principle, calculation method for the process analysis and research, compare the similarities and the advantages and disadvantages, the analysis of practical engineering problems to provide the reference for every profession and trade, as well as the future welded structure fatigue strength and life evaluation method put forward outlook.
Immunoturbidimetric quantification of serum immunoglobulin G concentration in foals.

PubMed

Bauer, J E; Brooks, T P

1990-08-01

Immunoturbidimetric determination of serum IgG concentration in foals was compared with the reference methods of single radial immunodiffusion and serum protein electrophoresis. High positive correlations were discovered when the technique was compared with either of these reference methods. The zinc sulfate turbidity test for serum IgG estimation was also evaluated. Although a positive correlation was discovered when the latter method was compared with reference methods, it was not as strong as the correlation between reference methods and the immunoturbidimetric method. The immunoturbidimetric method used in this study is specific and precise for equine serum IgG determination. It is rapid and, thus, is advantageous when timely evaluation of critically ill foals is necessary. The technique should be adaptable to various spectrophotometers and microcomputers for widespread application in veterinary medicine.
Measurement of single soybean seed attributes by near infrared technologies. A comparative study

USDA-ARS?s Scientific Manuscript database

Four near infrared spectrophotometers, and their associated spectral collection methods, were tested and compared for measuring three soybean single seed attributes: weight (g), protein (%), and oil (%). Using partial least squares (PLS) and 4 preprocessing methods, the attribute which was significa...
Comparative analysis of cryopreservation methods in Chlamydomonas reinhardtii.

PubMed

Scarbrough, Chasity; Wirschell, Maureen

2016-10-01

Chlamydomonas is a model organism used for studies of many important biological processes. Traditionally, strains have been propagated on solid agar, which requires routine passaging for long-term maintenance. Cryopreservation of Chlamydomonas is possible, yet long-term viability is highly variable. Thus, improved cryopreservation methods for Chlamydomonas are an important requirement for sustained study of genetically defined strains. Here, we tested a commercial cryopreservation kit and directly compared it's effectiveness to a methanol-based method. We also tested thaw-back procedures comparing the growth of cells in liquid culture or on solid agar media. We demonstrated that methanol was the superior cryopreservation method for Chlamydomonas compared to the commercial kit and that post-thaw culture conditions dramatically affect viability. We also demonstrated that cryopreserved cells could be successfully thawed and plated directly onto solid agar plates. Our findings have important implications for the long-term storage of Chlamydomonas that can likely be extended to other algal species. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.
Center index method-an alternative for wear measurements with radiostereometry (RSA).

PubMed

Dahl, Jon; Figved, Wender; Snorrason, Finnur; Nordsletten, Lars; Röhrl, Stephan M

2013-03-01

Radiostereometry (RSA) is considered to be the most precise and accurate method for wear-measurements in total hip replacement. Post-operative stereoradiographs has so far been necessary for wear measurement. Hence, the use of RSA has been limited to studies planned for RSA measurements. We compared a new RSA method for wear measurements that does not require previous radiographs with conventional RSA. Instead of comparing present stereoradiographs with post-operative ones, we developed a method for calculating the post-operative position of the center of the femoral head on the present examination and using this as the index measurement. We compared this alternative method to conventional RSA in 27 hips in an ongoing RSA study. We found a high degree of agreement between the methods for both mean proximal (1.19 mm vs. 1.14 mm) and mean 3D wear (1.52 mm vs. 1.44 mm) after 10 years. Intraclass correlation coefficients (ICC) were 0.958 and 0.955, respectively (p<0.001 for both ICCs). The results were also within the limits of agreement when plotted subject-by-subject in a Bland-Altman plot. Our alternative method for wear measurements with RSA offers comparable results to conventional RSA measurements. It allows precise wear measurements without previous radiological examinations. Copyright © 2012 Orthopaedic Research Society.
Quality of Austrian and Dutch Falls-Prevention Information: A Comparative Descriptive Study

ERIC Educational Resources Information Center

Schoberer, Daniela; Mijnarends, Donja M.; Fliedner, Monica; Halfens, Ruud J. G.; Lohrmann, Christa

2016-01-01

Objectives: The aim of this study was to evaluate and compare the quality of written patient information material available in Austrian and Dutch hospitals and nursing homes pertaining to falls prevention. Design: Comparative descriptive study design Setting: Hospitals and nursing homes in Austria and the Netherlands. Method: Written patient…
Compensation of kinematic geometric parameters error and comparative study of accuracy testing for robot

NASA Astrophysics Data System (ADS)

Du, Liang; Shi, Guangming; Guan, Weibin; Zhong, Yuansheng; Li, Jin

2014-12-01

Geometric error is the main error of the industrial robot, and it plays a more significantly important fact than other error facts for robot. The compensation model of kinematic error is proposed in this article. Many methods can be used to test the robot accuracy, therefore, how to compare which method is better one. In this article, a method is used to compare two methods for robot accuracy testing. It used Laser Tracker System (LTS) and Three Coordinate Measuring instrument (TCM) to test the robot accuracy according to standard. According to the compensation result, it gets the better method which can improve the robot accuracy apparently.
VIDAS Listeria species Xpress (LSX).

PubMed

Johnson, Ronald; Mills, John

2013-01-01

The AOAC GovVal study compared the VIDAS Listeria species Xpress (LSX) to the Health Products and Food Branch MFHPB-30 reference method for detection of Listeria on stainless steel. The LSX method utilizes a novel and proprietary enrichment media, Listeria Xpress broth, enabling detection of Listeria species in environmental samples with the automated VIDAS in a minimum of 26 h. The LSX method also includes the use of the chromogenic media, chromID Ottaviani Agosti Agar (OAA) and chromID Lmono for confirmation of LSX presumptive results. In previous AOAC validation studies comparing VIDAS LSX to the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) and the U.S. Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS) reference methods, the LSX method was approved as AOAC Official Method 2010.02 for the detection of Listeria species in dairy products, vegetables, seafood, raw meats and poultry, and processed meats and poultry, and as AOAC Performance Tested Method 100501 in a variety of foods and on environmental surfaces. The GovVal comparative study included 20 replicate test portions each at two contamination levels for stainless steel where fractionally positive results (5-15 positive results/20 replicate portions tested) were obtained by at least one method at one level. Five uncontaminated controls were included. In the stainless steel artificially contaminated surface study, there were 25 confirmed positives by the VIDAS LSX assay and 22 confirmed positives by the standard culture methods. Chi-square analysis indicated no statistical differences between the VIDAS LSX method and the MFHPB-30 standard methods at the 5% level of significance. Confirmation of presumptive LSX results with the chromogenic OAA and Lmono media was shown to be equivalent to the appropriate reference method agars. The data in this study demonstrate that the VIDAS LSX method is an acceptable alternative method to the MFHPB-30 standard culture method for the detection of Listeria species on stainless steel.
Cost-effectiveness of peer role play and standardized patients in undergraduate communication training.

PubMed

Bosse, Hans Martin; Nickel, Martin; Huwendiek, Sören; Schultz, Jobst Hendrik; Nikendei, Christoph

2015-10-24

The few studies directly comparing the methodological approach of peer role play (RP) and standardized patients (SP) for the delivery of communication skills all suggest that both methods are effective. In this study we calculated the costs of both methods (given comparable outcomes) and are the first to generate a differential cost-effectiveness analysis of both methods. Medical students in their prefinal year were randomly assigned to one of two groups receiving communication training in Pediatrics either with RP (N = 34) or 19 individually trained SP (N = 35). In an OSCE with standardized patients using the Calgary-Cambridge Referenced Observation Guide both groups achieved comparable high scores (results published). In this study, corresponding costs were assessed as man-hours resulting from hours of work of SP and tutors. A cost-effectiveness analysis was performed. Cost-effectiveness analysis revealed a major advantage for RP as compared to SP (112 vs. 172 man hours; cost effectiveness ratio .74 vs. .45) at comparable performance levels after training with both methods. While both peer role play and training with standardized patients have their value in medical curricula, RP has a major advantage in terms of cost-effectiveness. This could be taken into account in future decisions.
Circumferential finger measurements utilizing a torque meter to increase reliability.

PubMed

King, T I

1993-01-01

The purpose of this study was to compare the reliabilities of two methods of measuring finger circumference. Traditionally, finger circumference is determined clinically by the use of a tape measure. In this study, a tape-measure device for recording finger circumference utilizing a torque meter was compared with the traditional method to determine reliability differences. Ninety-two occupational therapists and occupational therapy students obtained circumferential measurements of the author's left index finger at the middle of the proximal phalanx utilizing the two methods. The readings obtained for each method were analyzed to determine the coefficient of variation and to compare their variances. The coefficient of variation for the traditional method was 2.92 and for the device utilizing the torque meter was 0.75. The F ratio was 15.63, which is significant at the 0.01 level. The results of this study indicate greater interrater reliability using a device that can accurately measure torque and allow the therapist to control the amount of tension applied when obtaining circumferential measurements using a tape measure.

Comparative evolution of the inverse problems (Introduction to an interdisciplinary study of the inverse problems)

NASA Technical Reports Server (NTRS)

Sabatier, P. C.

1972-01-01

The progressive realization of the consequences of nonuniqueness imply an evolution of both the methods and the centers of interest in inverse problems. This evolution is schematically described together with the various mathematical methods used. A comparative description is given of inverse methods in scientific research, with examples taken from mathematics, quantum and classical physics, seismology, transport theory, radiative transfer, electromagnetic scattering, electrocardiology, etc. It is hoped that this paper will pave the way for an interdisciplinary study of inverse problems.
Comarison of Four Methods for Teaching Phases of the Moon

NASA Astrophysics Data System (ADS)

Upton, Brianna; Cid, Ximena; Lopez, Ramon

2008-03-01

Previous studies have shown that many students have misconceptions about basic concepts in astronomy. As a consequence, various interactive engagement methods have been developed for introductory astronomy. We will present the results of a study that compares four different teaching methods for the subject of the phases of the Moon, which is well known to produce student difficulties. We compare a fairly traditional didactic approach, the use of manipulatives (moonballs) in lecture, the University of Arizona Lecture Tutorials, and an interactive computer program used in a didactic fashion. We use pre- and post-testing with the Lunar Phase Concept Inventory to determine the relative effectiveness of these methods.
Comparison of the vanadate oxidase method with the diazo method for serum bilirubin determination in dog, monkey, and rat.

PubMed

Ameri, Mehrdad; Schnaars, Henry; Sibley, John; Honor, David

2011-01-01

The most widely used method for bilirubin concentration determination is the diazo method, which measures the color of azobilirubin. The vanadate oxidase method is based on oxidation of bilirubin to biliverdin by vanadate. The objective of this study was to compare total and direct bilirubin concentration ([Bt] and [Bd], respectively) determined by the diazo and vanadate oxidase methods in pooled serum samples from dogs, monkeys, and rats spiked with panels of different concentrations of bilirubin standards. Pooled serum samples from 40 dogs, 40 monkeys, and 60 rats were spiked with either ditaurine conjugates of bilirubin or a standard reference material. The results obtained from both assays were compared using Deming regression analysis. The intra- and interassay precision, expressed as a percentage of the coefficient of variation (%CV), was determined for [Bt] and [Bd], and the mean percentage of recovery was calculated. The vanadate oxidase method displayed an excellent correlation (r = 0.99-1.00) with the diazo method. Using Deming regression, there were minimal negative or positive constant and proportional biases for [Bt] and [Bd]. The precision studies revealed that the vanadate oxidase method has comparable between-run and within-run CVs to those of the diazo method. The recovery study demonstrated that the diazo method more closely approximates the expected values of [Bt]. In conclusion, the vanadate oxidase method is a simple and rapid method that can be employed as an alternative to the diazo method when interfering substances are present in the serum samples of dog, monkey, and rat.
Comparing the long-term retention of a physiology course for medical students with the traditional and problem-based learning.

PubMed

Pourshanazari, A A; Roohbakhsh, A; Khazaei, M; Tajadini, H

2013-03-01

The rapid improvements in medical sciences and the ever-increasing related data, however, require novel methods of instruction. One such method, which has been given less than due attention in Iran, is problem-based learning (PBL). In this study, we aimed to evaluate the impact of study skills and the PBL methods on short and long-term retention of information provided for medical students in the course of respiratory physiology and compare it with traditional learning method. In this study, 39 medical students from Medical School of Kerman University of Medical Sciences, Kerman, Iran (2006-2010) were enrolled in the study and allocated randomly in three equal groups (13 in each group). All groups underwent a pre-test to be assessed for their basic information regarding respiratory physiology. Two groups were instructed using the traditional method, and one group used PBL. Among the two groups of the traditional method, one was instructed about study skills and the other was not. Once the PBL group took the study skill workshop, they were aided by tutors for their education. In the final term test, those students who had learned study skills and were instructed with the traditional method scored higher compared to other groups (p < 0.05). However, in the 1 year (p < 0.05) and 4 year (p < 0.01) interval examinations, the PBL group achieved significantly higher scores. Despite the fact that PBL had no positive effect on the final term exam of our students, it yielded a more profound and retained understanding of the subject course. Moreover, considering the positive effect of study skills on long-term student scores, we recommend students to receive instructions regarding the appropriate study skills when initiated into universities.
Comparison study on flexible pavement design using FAA (Federal Aviation Administration) and LCN (Load Classification Number) code in Ahmad Yani international airport’s runway

NASA Astrophysics Data System (ADS)

Santoso, S. E.; Sulistiono, D.; Mawardi, A. F.

2017-11-01

FAA code for airport design has been broadly used by Indonesian Ministry of Aviation since decades ago. However, there is not much comprehensive study about its relevance and efficiency towards current situation in Indonesia. Therefore, a further comparison study on flexible pavement design for airport runway using comparable method has become essential. The main focus of this study is to compare which method between FAA and LCN that offer the most efficient and effective way in runway pavement planning. The comparative methods in this study mainly use the variety of variable approach. FAA code for instance, will use the approach on the aircraft’s maximum take-off weight and annual departure. Whilst LCN code use the variable of equivalent single wheel load and tire pressure. Based on the variables mentioned above, a further classification and rated method will be used to determine which code is best implemented. According to the analysis, it is clear that FAA method is the most effective way to plan runway design in Indonesia with consecutively total pavement thickness of 127cm and LCN method total pavement thickness of 70cm. Although, FAA total pavement is thicker that LCN its relevance towards sustainable and pristine condition in the future has become an essential aspect to consider in design and planning.
A method for removing arm backscatter from EPID images

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

King, Brian W.; Greer, Peter B.; School of Mathematical and Physical Sciences, University of Newcastle, Newcastle, New South Wales 2308

2013-07-15

Purpose: To develop a method for removing the support arm backscatter from images acquired using current Varian electronic portal imaging devices (EPIDs).Methods: The effect of arm backscatter on EPID images was modeled using a kernel convolution method. The parameters of the model were optimized by comparing on-arm images to off-arm images. The model was used to develop a method to remove the effect of backscatter from measured EPID images. The performance of the backscatter removal method was tested by comparing backscatter corrected on-arm images to measured off-arm images for 17 rectangular fields of different sizes and locations on the imager.more » The method was also tested using on- and off-arm images from 42 intensity modulated radiotherapy (IMRT) fields.Results: Images generated by the backscatter removal method gave consistently better agreement with off-arm images than images without backscatter correction. For the 17 rectangular fields studied, the root mean square difference of in-plane profiles compared to off-arm profiles was reduced from 1.19% (standard deviation 0.59%) on average without backscatter removal to 0.38% (standard deviation 0.18%) when using the backscatter removal method. When comparing to the off-arm images from the 42 IMRT fields, the mean {gamma} and percentage of pixels with {gamma} < 1 were improved by the backscatter removal method in all but one of the images studied. The mean {gamma} value (1%, 1 mm) for the IMRT fields studied was reduced from 0.80 to 0.57 by using the backscatter removal method, while the mean {gamma} pass rate was increased from 72.2% to 84.6%.Conclusions: A backscatter removal method has been developed to estimate the image acquired by the EPID without any arm backscatter from an image acquired in the presence of arm backscatter. The method has been shown to produce consistently reliable results for a wide range of field sizes and jaw configurations.« less
A comparative study of clock rate and drift estimation

NASA Technical Reports Server (NTRS)

Breakiron, Lee A.

1994-01-01

Five different methods of drift determination and four different methods of rate determination were compared using months of hourly phase and frequency data from a sample of cesium clocks and active hydrogen masers. Linear least squares on frequency is selected as the optimal method of determining both drift and rate, more on the basis of parameter parsimony and confidence measures than on random and systematic errors.
Comparison of methods for estimating density of forest songbirds from point counts

Treesearch

Jennifer L. Reidy; Frank R. Thompson; J. Wesley. Bailey

2011-01-01

New analytical methods have been promoted for estimating the probability of detection and density of birds from count data but few studies have compared these methods using real data. We compared estimates of detection probability and density from distance and time-removal models and survey protocols based on 5- or 10-min counts and outer radii of 50 or 100 m. We...
Experimental study and neural network modeling of sugarcane bagasse pretreatment with H2SO4 and O3 for cellulosic material conversion to sugar.

PubMed

Gitifar, Vahid; Eslamloueyan, Reza; Sarshar, Mohammad

2013-11-01

In this study, pretreatment of sugarcane bagasse and subsequent enzymatic hydrolysis is investigated using two categories of pretreatment methods: dilute acid (DA) pretreatment and combined DA-ozonolysis (DAO) method. Both methods are accomplished at different solid ratios, sulfuric acid concentrations, autoclave residence times, bagasse moisture content, and ozonolysis time. The results show that the DAO pretreatment can significantly increase the production of glucose compared to DA method. Applying k-fold cross validation method, two optimal artificial neural networks (ANNs) are trained for estimations of glucose concentrations for DA and DAO pretreatment methods. Comparing the modeling results with experimental data indicates that the proposed ANNs have good estimation abilities. Copyright © 2013 Elsevier Ltd. All rights reserved.
Near-surface shear-wave velocity measurements in unlithified sediment

USGS Publications Warehouse

Richards, B.T.; Steeples, D.; Miller, R.; Ivanov, J.; Peterie, S.; Sloan, S.D.; McKenna, J.R.

2011-01-01

S-wave velocity can be directly correlated to material stiffness and lithology making it a valuable physical property that has found uses in construction, engineering, and environmental projects. This study compares different methods for measuring S-wave velocities, investigating and identifying the differences among the methods' results, and prioritizing the different methods for optimal S-wave use at the U. S. Army's Yuma Proving Grounds YPG. Multichannel Analysis of Surface Waves MASW and S-wave tomography were used to generate S-wave velocity profiles. Each method has advantages and disadvantages. A strong signal-to-noise ratio at the study site gives the MASW method promising resolution. S-wave first arrivals are picked on impulsive sledgehammer data which were then used for the tomography process. Three-component downhole seismic data were collected in-line with a locking geophone, providing ground truth to compare the data and to draw conclusions about the validity of each data set. Results from these S-wave measurement techniques are compared with borehole seismic data and with lithology data from continuous samples to help ascertain the accuracy, and therefore applicability, of each method. This study helps to select the best methods for obtaining S-wave velocities for media much like those found in unconsolidated sediments at YPG. ?? 2011 Society of Exploration Geophysicists.
Continuous Wavelet Transform, a powerful alternative to Derivative Spectrophotometry in analysis of binary and ternary mixtures: A comparative study.

PubMed

Elzanfaly, Eman S; Hassan, Said A; Salem, Maissa Y; El-Zeany, Badr A

2015-12-05

A comparative study was established between two signal processing techniques showing the theoretical algorithm for each method and making a comparison between them to indicate the advantages and limitations. The methods under study are Numerical Differentiation (ND) and Continuous Wavelet Transform (CWT). These methods were studied as spectrophotometric resolution tools for simultaneous analysis of binary and ternary mixtures. To present the comparison, the two methods were applied for the resolution of Bisoprolol (BIS) and Hydrochlorothiazide (HCT) in their binary mixture and for the analysis of Amlodipine (AML), Aliskiren (ALI) and Hydrochlorothiazide (HCT) as an example for ternary mixtures. By comparing the results in laboratory prepared mixtures, it was proven that CWT technique is more efficient and advantageous in analysis of mixtures with severe overlapped spectra than ND. The CWT was applied for quantitative determination of the drugs in their pharmaceutical formulations and validated according to the ICH guidelines where accuracy, precision, repeatability and robustness were found to be within the acceptable limit. Copyright © 2015 Elsevier B.V. All rights reserved.
Do observational studies using propensity score methods agree with randomized trials? A systematic comparison of studies on acute coronary syndromes

PubMed Central

Dahabreh, Issa J.; Sheldrick, Radley C.; Paulus, Jessica K.; Chung, Mei; Varvarigou, Vasileia; Jafri, Haseeb; Rassen, Jeremy A.; Trikalinos, Thomas A.; Kitsios, Georgios D.

2012-01-01

Aims Randomized controlled trials (RCTs) are the gold standard for assessing the efficacy of therapeutic interventions because randomization protects from biases inherent in observational studies. Propensity score (PS) methods, proposed as a potential solution to confounding of the treatment–outcome association, are widely used in observational studies of therapeutic interventions for acute coronary syndromes (ACS). We aimed to systematically assess agreement between observational studies using PS methods and RCTs on therapeutic interventions for ACS. Methods and results We searched for observational studies of interventions for ACS that used PS methods to estimate treatment effects on short- or long-term mortality. Using a standardized algorithm, we matched observational studies to RCTs based on patients’ characteristics, interventions, and outcomes (‘topics’), and we compared estimates of treatment effect between the two designs. When multiple observational studies or RCTs were identified for the same topic, we performed a meta-analysis and used the summary relative risk for comparisons. We matched 21 observational studies investigating 17 distinct clinical topics to 63 RCTs (median = 3 RCTs per observational study) for short-term (7 topics) and long-term (10 topics) mortality. Estimates from PS analyses differed statistically significantly from randomized evidence in two instances; however, observational studies reported more extreme beneficial treatment effects compared with RCTs in 13 of 17 instances (P = 0.049). Sensitivity analyses limited to large RCTs, and using alternative meta-analysis models yielded similar results. Conclusion For the treatment of ACS, observational studies using PS methods produce treatment effect estimates that are of more extreme magnitude compared with those from RCTs, although the differences are rarely statistically significant. PMID:22711757
Multi-reader ROC studies with split-plot designs: a comparison of statistical methods.

PubMed

Obuchowski, Nancy A; Gallas, Brandon D; Hillis, Stephen L

2012-12-01

Multireader imaging trials often use a factorial design, in which study patients undergo testing with all imaging modalities and readers interpret the results of all tests for all patients. A drawback of this design is the large number of interpretations required of each reader. Split-plot designs have been proposed as an alternative, in which one or a subset of readers interprets all images of a sample of patients, while other readers interpret the images of other samples of patients. In this paper, the authors compare three methods of analysis for the split-plot design. Three statistical methods are presented: the Obuchowski-Rockette method modified for the split-plot design, a newly proposed marginal-mean analysis-of-variance approach, and an extension of the three-sample U-statistic method. A simulation study using the Roe-Metz model was performed to compare the type I error rate, power, and confidence interval coverage of the three test statistics. The type I error rates for all three methods are close to the nominal level but tend to be slightly conservative. The statistical power is nearly identical for the three methods. The coverage of 95% confidence intervals falls close to the nominal coverage for small and large sample sizes. The split-plot multireader, multicase study design can be statistically efficient compared to the factorial design, reducing the number of interpretations required per reader. Three methods of analysis, shown to have nominal type I error rates, similar power, and nominal confidence interval coverage, are available for this study design. Copyright © 2012 AUR. All rights reserved.
Methods for Developing Evidence Reviews in Short Periods of Time: A Scoping Review

PubMed Central

Abou-Setta, Ahmed M.; Jeyaraman, Maya; Attia, Abdelhamid; Al-Inany, Hesham G.; Ferri, Mauricio; Ansari, Mohammed T.; Garritty, Chantelle M.; Bond, Kenneth; Norris, Susan L.

2016-01-01

Introduction Rapid reviews (RR), using abbreviated systematic review (SR) methods, are becoming more popular among decision-makers. This World Health Organization commissioned study sought to summarize RR methods, identify differences, and highlight potential biases between RR and SR. Methods Review of RR methods (Key Question 1 [KQ1]), meta-epidemiologic studies comparing reliability/ validity of RR and SR methods (KQ2), and their potential associated biases (KQ3). We searched Medline, EMBASE, Cochrane Library, grey literature, and checked reference lists, used personal contacts, and crowdsourcing (e.g. email listservs). Selection and data extraction was conducted by one reviewer (KQ1) or two reviewers independently (KQ2-3). Results Across all KQs, we identified 42,743 citations through the literature searches. KQ1: RR methods from 29 organizations were reviewed. There was no consensus on which aspects of the SR process to abbreviate. KQ2: Studies comparing the conclusions of RR and SR (n = 9) found them to be generally similar. Where major differences were identified, it was attributed to the inclusion of evidence from different sources (e.g. searching different databases or including different study designs). KQ3: Potential biases introduced into the review process were well-identified although not necessarily supported by empirical evidence, and focused mainly on selective outcome reporting and publication biases. Conclusion RR approaches are context and organization specific. Existing comparative evidence has found similar conclusions derived from RR and SR, but there is a lack of evidence comparing the potential of bias in both evidence synthesis approaches. Further research and decision aids are needed to help decision makers and reviewers balance the benefits of providing timely evidence with the potential for biased findings. PMID:27930662
A comparative uncertainty study of the calibration of macrolide antibiotic reference standards using quantitative nuclear magnetic resonance and mass balance methods.

PubMed

Liu, Shu-Yu; Hu, Chang-Qin

2007-10-17

This study introduces the general method of quantitative nuclear magnetic resonance (qNMR) for the calibration of reference standards of macrolide antibiotics. Several qNMR experimental conditions were optimized including delay, which is an important parameter of quantification. Three kinds of macrolide antibiotics were used to validate the accuracy of the qNMR method by comparison with the results obtained by the high performance liquid chromatography (HPLC) method. The purities of five common reference standards of macrolide antibiotics were measured by the 1H qNMR method and the mass balance method, respectively. The analysis results of the two methods were compared. The qNMR is quick and simple to use. In a new medicine research and development process, qNMR provides a new and reliable method for purity analysis of the reference standard.
Different spectrophotometric methods applied for the analysis of binary mixture of flucloxacillin and amoxicillin: A comparative study.

PubMed

Attia, Khalid A M; Nassar, Mohammed W I; El-Zeiny, Mohamed B; Serag, Ahmed

2016-05-15

Three different spectrophotometric methods were applied for the quantitative analysis of flucloxacillin and amoxicillin in their binary mixture, namely, ratio subtraction, absorbance subtraction and amplitude modulation. A comparative study was done listing the advantages and the disadvantages of each method. All the methods were validated according to the ICH guidelines and the obtained accuracy, precision and repeatability were found to be within the acceptable limits. The selectivity of the proposed methods was tested using laboratory prepared mixtures and assessed by applying the standard addition technique. So, they can be used for the routine analysis of flucloxacillin and amoxicillin in their binary mixtures. Copyright © 2016 Elsevier B.V. All rights reserved.
Automatic identification of comparative effectiveness research from Medline citations to support clinicians’ treatment information needs

PubMed Central

Zhang, Mingyuan; Fiol, Guilherme Del; Grout, Randall W.; Jonnalagadda, Siddhartha; Medlin, Richard; Mishra, Rashmi; Weir, Charlene; Liu, Hongfang; Mostafa, Javed; Fiszman, Marcelo

2014-01-01

Online knowledge resources such as Medline can address most clinicians’ patient care information needs. Yet, significant barriers, notably lack of time, limit the use of these sources at the point of care. The most common information needs raised by clinicians are treatment-related. Comparative effectiveness studies allow clinicians to consider multiple treatment alternatives for a particular problem. Still, solutions are needed to enable efficient and effective consumption of comparative effectiveness research at the point of care. Objective Design and assess an algorithm for automatically identifying comparative effectiveness studies and extracting the interventions investigated in these studies. Methods The algorithm combines semantic natural language processing, Medline citation metadata, and machine learning techniques. We assessed the algorithm in a case study of treatment alternatives for depression. Results Both precision and recall for identifying comparative studies was 0.83. A total of 86% of the interventions extracted perfectly or partially matched the gold standard. Conclusion Overall, the algorithm achieved reasonable performance. The method provides building blocks for the automatic summarization of comparative effectiveness research to inform point of care decision-making. PMID:23920677
Antenatal breastfeeding education for increasing breastfeeding duration

PubMed Central

Lumbiganon, Pisake; Martis, Ruth; Laopaiboon, Malinee; Festin, Mario R; Ho, Jacqueline J; Hakimi, Mohammad

2014-01-01

Background Breastfeeding (BF) is well recognised as the best food for infants. The impact of antenatal BF education on the duration of BF has not been evaluated. Objectives To evaluate the effectiveness of antenatal BF education for increasing BF initiation and duration. Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (21 April 2010), CENTRAL (The Cochrane Library 2010, Issue 2), MEDLINE (1966 to April 2010) and SCOPUS (January 1985 to April 2010). We contacted experts and searched reference lists of retrieved articles. We updated the search of the Pregnancy and Childbirth Group’s Trials Register on 28 September 2011 and added the results to the awaiting classification section of the review. Selection criteria All identified published, unpublished and ongoing randomised controlled trials (RCTs) assessing the effect of formal antenatal BF education or comparing two different methods of formal antenatal BF education, on duration of BF. We excluded RCTs that also included intrapartum or postpartum BF education. Data collection and analysis We assessed all potential studies identified as a result of the search strategy. Two review authors extracted data from each included study using the agreed form and assessed risk of bias. We resolved discrepancies through discussion. Main results We included 17 studies with 7131 women in the review and 14 studies involving 6932 women contributed data to the analyses. We did not do any meta-analysis because there was only one study for each comparison. Five studies compared a single method of BF education with routine care. Peer counselling significantly increased BF initiation. Three studies compared one form of BF education versus another. No intervention was significantly more effective than another intervention in increasing initiation or duration of BF. Seven studies compared multiple methods versus a single method of BF education. Combined BF educational interventions were not significantly better than a single intervention in initiating or increasing BF duration. However, in one trial a combined BF education significantly reduced nipple pain and trauma. One study compared different combinations of interventions. There was a marginally significant increase in exclusive BF at six months in women receiving a booklet plus video plus lactation consultation (LC) compared with the booklet plus video only. Two studies compared multiple methods of BF education versus routine care. The combination of BF booklet plus video plus LC was significantly better than routine care for exclusive BF at three months. Authors’ conclusions Because there were significant methodological limitations and the observed effect sizes were small, it is not appropriate to recommend any antenatal BF education. There is an urgent need to conduct RCTs study with adequate power to evaluate the effectiveness of antenatal BF education. PMID:22071830
Clothing Protection from Ultraviolet Radiation: A New Method for Assessment.

PubMed

Gage, Ryan; Leung, William; Stanley, James; Reeder, Anthony; Barr, Michelle; Chambers, Tim; Smith, Moira; Signal, Louise

2017-11-01

Clothing modifies ultraviolet radiation (UVR) exposure from the sun and has an impact on skin cancer risk and the endogenous synthesis of vitamin D. There is no standardized method available for assessing body surface area (BSA) covered by clothing, which limits generalizability between study findings. We calculated the body cover provided by 38 clothing items using diagrams of BSA, adjusting the values to account for differences in BSA by age. Diagrams displaying each clothing item were developed and incorporated into a coverage assessment procedure (CAP). Five assessors used the CAP and Lund & Browder chart, an existing method for estimating BSA, to calculate the clothing coverage of an image sample of 100 schoolchildren. Values of clothing coverage, inter-rater reliability and assessment time were compared between CAP and Lund & Browder methods. Both methods had excellent inter-rater reliability (>0.90) and returned comparable results, although the CAP method was significantly faster in determining a person's clothing coverage. On balance, the CAP method appears to be a feasible method for calculating clothing coverage. Its use could improve comparability between sun-safety studies and aid in quantifying the health effects of UVR exposure. © 2017 The American Society of Photobiology.
Comparative Robustness of Recent Methods for Analyzing Multivariate Repeated Measures Designs

ERIC Educational Resources Information Center

Seco, Guillermo Vallejo; Gras, Jaime Arnau; Garcia, Manuel Ato

2007-01-01

This study evaluated the robustness of two recent methods for analyzing multivariate repeated measures when the assumptions of covariance homogeneity and multivariate normality are violated. Specifically, the authors' work compares the performance of the modified Brown-Forsythe (MBF) procedure and the mixed-model procedure adjusted by the…

Multilevel Propensity Score Matching within and across Schools

ERIC Educational Resources Information Center

Kelcey, Benjamin

2011-01-01

A central issue in nonexperimental studies is the identification of comparable individuals (e.g. students) to remove selection bias. One such increasingly common method to identify comparable individuals and address selection bias is the propensity score (PS). PS methods rely on a model of the treatment assignment to identify comparable…
Comparison of volume estimation methods for pancreatic islet cells

NASA Astrophysics Data System (ADS)

Dvořák, JiřÃ.; Å vihlík, Jan; Habart, David; Kybic, Jan

2016-03-01

In this contribution we study different methods of automatic volume estimation for pancreatic islets which can be used in the quality control step prior to the islet transplantation. The total islet volume is an important criterion in the quality control. Also, the individual islet volume distribution is interesting -- it has been indicated that smaller islets can be more effective. A 2D image of a microscopy slice containing the islets is acquired. The input of the volume estimation methods are segmented images of individual islets. The segmentation step is not discussed here. We consider simple methods of volume estimation assuming that the islets have spherical or ellipsoidal shape. We also consider a local stereological method, namely the nucleator. The nucleator does not rely on any shape assumptions and provides unbiased estimates if isotropic sections through the islets are observed. We present a simulation study comparing the performance of the volume estimation methods in different scenarios and an experimental study comparing the methods on a real dataset.
A Simple and Efficient Method of Extracting DNA from Aged Bones and Teeth.

PubMed

Liu, Qiqi; Liu, Liyan; Zhang, Minli; Zhang, Qingzhen; Wang, Qiong; Ding, Xiaoran; Shao, Liting; Zhou, Zhe; Wang, Shengqi

2018-05-01

DNA is often difficult to extract from old bones and teeth due to low levels of DNA and high levels of degradation. This study established a simple yet efficient method for extracting DNA from 20 aged bones and teeth (approximately 60 years old). Based on the concentration and STR typing results, the new method of DNA extraction (OM) developed in this study was compared with the PrepFiler™ BTA Forensic DNA Extraction Kit (BM). The total amount of DNA extracted using the OM method was not significantly different from that extracted using the commercial kit (p > 0.05). However, the number of STR loci detected was significantly higher in the samples processed using the OM method than using the BM method (p < 0.05). This study aimed to establish a DNA extraction method for aged bones and teeth to improve the detection rate of STR typing and reduce costs compared to the BM technique. © 2017 American Academy of Forensic Sciences.
Weber, Durkheim, and the comparative method.

PubMed

Kapsis, R E

1977-10-01

This essay compares and contrasts the means by which Durkheim and Weber dealt with methodological issues peculiar to the comparative study of societies, what Smelser has called "the problem of sociocultural variability and complexity." More specifically, it examines how Weber and Durkheim chose appropriate comparative units for their empirical studies. The approaches that Weber and Durkheim brought to theproblem of cross-cultural comparison have critical implications for more current procedures used in the comparative study of contemporary and historical societies.
Use of the landmark method to address immortal person-time bias in comparative effectiveness research: a simulation study.

PubMed

Mi, Xiaojuan; Hammill, Bradley G; Curtis, Lesley H; Lai, Edward Chia-Cheng; Setoguchi, Soko

2016-11-20

Observational comparative effectiveness and safety studies are often subject to immortal person-time, a period of follow-up during which outcomes cannot occur because of the treatment definition. Common approaches, like excluding immortal time from the analysis or naïvely including immortal time in the analysis, are known to result in biased estimates of treatment effect. Other approaches, such as the Mantel-Byar and landmark methods, have been proposed to handle immortal time. Little is known about the performance of the landmark method in different scenarios. We conducted extensive Monte Carlo simulations to assess the performance of the landmark method compared with other methods in settings that reflect realistic scenarios. We considered four landmark times for the landmark method. We found that the Mantel-Byar method provided unbiased estimates in all scenarios, whereas the exclusion and naïve methods resulted in substantial bias when the hazard of the event was constant or decreased over time. The landmark method performed well in correcting immortal person-time bias in all scenarios when the treatment effect was small, and provided unbiased estimates when there was no treatment effect. The bias associated with the landmark method tended to be small when the treatment rate was higher in the early follow-up period than it was later. These findings were confirmed in a case study of chronic obstructive pulmonary disease. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
Comparative study of landslides susceptibility mapping methods: Multi-Criteria Decision Making (MCDM) and Artificial Neural Network (ANN)

NASA Astrophysics Data System (ADS)

Salleh, S. A.; Rahman, A. S. A. Abd; Othman, A. N.; Mohd, W. M. N. Wan

2018-02-01

As different approach produces different results, it is crucial to determine the methods that are accurate in order to perform analysis towards the event. This research aim is to compare the Rank Reciprocal (MCDM) and Artificial Neural Network (ANN) analysis techniques in determining susceptible zones of landslide hazard. The study is based on data obtained from various sources such as local authority; Dewan Bandaraya Kuala Lumpur (DBKL), Jabatan Kerja Raya (JKR) and other agencies. The data were analysed and processed using Arc GIS. The results were compared by quantifying the risk ranking and area differential. It was also compared with the zonation map classified by DBKL. The results suggested that ANN method gives better accuracy compared to MCDM with 18.18% higher accuracy assessment of the MCDM approach. This indicated that ANN provides more reliable results and it is probably due to its ability to learn from the environment thus portraying realistic and accurate result.
Boar taint detection: A comparison of three sensory protocols.

PubMed

Trautmann, Johanna; Meier-Dinkel, Lisa; Gertheiss, Jan; Mörlein, Daniel

2016-01-01

While recent studies state an important role of human sensory methods for daily routine control of so-called boar taint, the evaluation of different heating methods is still incomplete. This study investigated three common heating methods (microwave (MW), hot-water (HW), hot-iron (HI)) for boar fat evaluation. The comparison was carried out on 72 samples with a 10-person sensory panel. The heating method significantly affected the probability of a deviant rating. Compared to an assumed 'gold standard' (chemical analysis), the performance was best for HI when both sensitivity and specificity were considered. The results show the superiority of the panel result compared to individual assessors. However, the consistency of the individual sensory ratings was not significantly different between MW, HW, and HI. The three protocols showed only fair to moderate agreement. Concluding from the present results, the hot-iron method appears to be advantageous for boar taint evaluation as compared to microwave and hot-water. Copyright © 2015. Published by Elsevier Ltd.
A comparative study of electrochemical machining process parameters by using GA and Taguchi method

NASA Astrophysics Data System (ADS)

Soni, S. K.; Thomas, B.

2017-11-01

In electrochemical machining quality of machined surface strongly depend on the selection of optimal parameter settings. This work deals with the application of Taguchi method and genetic algorithm using MATLAB to maximize the metal removal rate and minimize the surface roughness and overcut. In this paper a comparative study is presented for drilling of LM6 AL/B4C composites by comparing the significant impact of numerous machining process parameters such as, electrolyte concentration (g/l),machining voltage (v),frequency (hz) on the response parameters (surface roughness, material removal rate and over cut). Taguchi L27 orthogonal array was chosen in Minitab 17 software, for the investigation of experimental results and also multiobjective optimization done by genetic algorithm is employed by using MATLAB. After obtaining optimized results from Taguchi method and genetic algorithm, a comparative results are presented.
A feasibility study in adapting Shamos Bickel and Hodges Lehman estimator into T-Method for normalization

NASA Astrophysics Data System (ADS)

Harudin, N.; Jamaludin, K. R.; Muhtazaruddin, M. Nabil; Ramlie, F.; Muhamad, Wan Zuki Azman Wan

2018-03-01

T-Method is one of the techniques governed under Mahalanobis Taguchi System that developed specifically for multivariate data predictions. Prediction using T-Method is always possible even with very limited sample size. The user of T-Method required to clearly understanding the population data trend since this method is not considering the effect of outliers within it. Outliers may cause apparent non-normality and the entire classical methods breakdown. There exist robust parameter estimate that provide satisfactory results when the data contain outliers, as well as when the data are free of them. The robust parameter estimates of location and scale measure called Shamos Bickel (SB) and Hodges Lehman (HL) which are used as a comparable method to calculate the mean and standard deviation of classical statistic is part of it. Embedding these into T-Method normalize stage feasibly help in enhancing the accuracy of the T-Method as well as analysing the robustness of T-method itself. However, the result of higher sample size case study shows that T-method is having lowest average error percentages (3.09%) on data with extreme outliers. HL and SB is having lowest error percentages (4.67%) for data without extreme outliers with minimum error differences compared to T-Method. The error percentages prediction trend is vice versa for lower sample size case study. The result shows that with minimum sample size, which outliers always be at low risk, T-Method is much better on that, while higher sample size with extreme outliers, T-Method as well show better prediction compared to others. For the case studies conducted in this research, it shows that normalization of T-Method is showing satisfactory results and it is not feasible to adapt HL and SB or normal mean and standard deviation into it since it’s only provide minimum effect of percentages errors. Normalization using T-method is still considered having lower risk towards outlier’s effect.
Comparison of three different prehospital wrapping methods for preventing hypothermia - a crossover study in humans

PubMed Central

2011-01-01

Background Accidental hypothermia increases mortality and morbidity in trauma patients. Various methods for insulating and wrapping hypothermic patients are used worldwide. The aim of this study was to compare the thermal insulating effects and comfort of bubble wrap, ambulance blankets / quilts, and Hibler's method, a low-cost method combining a plastic outer layer with an insulating layer. Methods Eight volunteers were dressed in moistened clothing, exposed to a cold and windy environment then wrapped using one of the three different insulation methods in random order on three different days. They were rested quietly on their back for 60 minutes in a cold climatic chamber. Skin temperature, rectal temperature, oxygen consumption were measured, and metabolic heat production was calculated. A questionnaire was used for a subjective evaluation of comfort, thermal sensation, and shivering. Results Skin temperature was significantly higher 15 minutes after wrapping using Hibler's method compared with wrapping with ambulance blankets / quilts or bubble wrap. There were no differences in core temperature between the three insulating methods. The subjects reported more shivering, they felt colder, were more uncomfortable, and had an increased heat production when using bubble wrap compared with the other two methods. Hibler's method was the volunteers preferred method for preventing hypothermia. Bubble wrap was the least effective insulating method, and seemed to require significantly higher heat production to compensate for increased heat loss. Conclusions This study demonstrated that a combination of vapour tight layer and an additional dry insulating layer (Hibler's method) is the most efficient wrapping method to prevent heat loss, as shown by increased skin temperatures, lower metabolic rate and better thermal comfort. This should then be the method of choice when wrapping a wet patient at risk of developing hypothermia in prehospital environments. PMID:21699720
Effectiveness and efficacy of minimally invasive lung volume reduction surgery for emphysema

PubMed Central

Pertl, Daniela; Eisenmann, Alexander; Holzer, Ulrike; Renner, Anna-Theresa; Valipour, A.

2014-01-01

Lung emphysema is a chronic, progressive and irreversible destruction of the lung tissue. Besides non-medical therapies and the well established medical treatment there are surgical and minimally invasive methods for lung volume reduction (LVR) to treat severe emphysema. This report deals with the effectiveness and cost-effectiveness of minimally invasive methods compared to other treatments for LVR in patients with lung emphysema. Furthermore, legal and ethical aspects are discussed. No clear benefit of minimally invasive methods compared to surgical methods can be demonstrated based on the identified and included evidence. In order to assess the different methods for LVR regarding their relative effectiveness and safety in patients with lung emphysema direct comparative studies are necessary. PMID:25295123
Effectiveness and efficacy of minimally invasive lung volume reduction surgery for emphysema.

PubMed

Pertl, Daniela; Eisenmann, Alexander; Holzer, Ulrike; Renner, Anna-Theresa; Valipour, A

2014-01-01

Lung emphysema is a chronic, progressive and irreversible destruction of the lung tissue. Besides non-medical therapies and the well established medical treatment there are surgical and minimally invasive methods for lung volume reduction (LVR) to treat severe emphysema. This report deals with the effectiveness and cost-effectiveness of minimally invasive methods compared to other treatments for LVR in patients with lung emphysema. Furthermore, legal and ethical aspects are discussed. No clear benefit of minimally invasive methods compared to surgical methods can be demonstrated based on the identified and included evidence. In order to assess the different methods for LVR regarding their relative effectiveness and safety in patients with lung emphysema direct comparative studies are necessary.
Cryopreservation of in vitro grown shoot tips of Diospyros kaki thunb. using different methods.

PubMed

Niu, Y L; Luo, Z R; Zhang, Y F; Zhang, Q L

2012-01-01

The objective of this study was to compare the potential of different cryopreservation strategies for in vitro shoot tips of Diospyros kaki Thunb. The treatments consisted of three different cryopreservation methods: vitrification, droplet-vitrification and modified droplet-vitrification. The following variables were assessed: cold acclimation, sucrose concentration in the preculture medium and PVS2 treatment time. A higher average survival level was obtained using the modified droplet-vitrification method compared to the other two methods.
Reply to “Ranking filter methods for concentrating pathogens in lake water”

USGS Publications Warehouse

Bushon, Rebecca N.; Francy, Donna S.; Gallardo, Vicente J.; Lindquist, H.D. Alan; Villegas, Eric N.; Ware, Michael W.

2013-01-01

Accurately comparing filtration methods is indeed difficult. Our method (1) and the method described by Borchardt et al. for determining recoveries are both acceptable approaches; however, each is designed to achieve a different research goal. Our study was designed to compare recoveries of multiple microorganisms in surface-water samples. Because, in practice, water-matrix effects come into play throughout filtration, concentration, and detection processes, we felt it important to incorporate those effects into the recovery results.
Imagery and Verbal Coding Approaches in Chinese Vocabulary Instruction

ERIC Educational Resources Information Center

Shen, Helen H.

2010-01-01

This study consists of two instructional experiments. Within the framework of dual coding theory, the study compares the learning effects of two instructional encoding methods used in Chinese vocabulary instruction among students learning beginning Chinese as a foreign language. One method uses verbal encoding only, and the other method uses…
Enhancing Learning Outcomes through Evaluation of Serious Gaming: A Mixed Methods Study

ERIC Educational Resources Information Center

Douglas, Kerrie Anna

2012-01-01

This study compared the change in counseling student's self-efficacy and skill related to suicide assessment and intervention through the use of a novel intervention-oriented evaluation method, evaluation focused discussion groups, in an experimental embedded mixed methods design. An innovation counselor pedagogical tool, Suicide Risk Assessment…
Theory, Method, and Triangulation in the Study of Street Children.

ERIC Educational Resources Information Center

Lucchini, Riccardo

1996-01-01

Describes how a comparative study of street children in Montevideo (Uruguay), Rio de Janeiro, and Mexico City contributes to a synergism between theory and method. Notes how theoretical approaches of symbolic interactionism, genetic structuralism, and habitus theory complement interview, participant observation, and content analysis methods;…
Research design and statistical methods in Pakistan Journal of Medical Sciences (PJMS).

PubMed

Akhtar, Sohail; Shah, Syed Wadood Ali; Rafiq, M; Khan, Ajmal

2016-01-01

This article compares the study design and statistical methods used in 2005, 2010 and 2015 of Pakistan Journal of Medical Sciences (PJMS). Only original articles of PJMS were considered for the analysis. The articles were carefully reviewed for statistical methods and designs, and then recorded accordingly. The frequency of each statistical method and research design was estimated and compared with previous years. A total of 429 articles were evaluated (n=74 in 2005, n=179 in 2010, n=176 in 2015) in which 171 (40%) were cross-sectional and 116 (27%) were prospective study designs. A verity of statistical methods were found in the analysis. The most frequent methods include: descriptive statistics (n=315, 73.4%), chi-square/Fisher's exact tests (n=205, 47.8%) and student t-test (n=186, 43.4%). There was a significant increase in the use of statistical methods over time period: t-test, chi-square/Fisher's exact test, logistic regression, epidemiological statistics, and non-parametric tests. This study shows that a diverse variety of statistical methods have been used in the research articles of PJMS and frequency improved from 2005 to 2015. However, descriptive statistics was the most frequent method of statistical analysis in the published articles while cross-sectional study design was common study design.
A review of randomized controlled trials comparing the effectiveness of hand held computers with paper methods for data collection

PubMed Central

Lane, Shannon J; Heddle, Nancy M; Arnold, Emmy; Walker, Irwin

2006-01-01

Background Handheld computers are increasingly favoured over paper and pencil methods to capture data in clinical research. Methods This study systematically identified and reviewed randomized controlled trials (RCTs) that compared the two methods for self-recording and reporting data, and where at least one of the following outcomes was assessed: data accuracy; timeliness of data capture; and adherence to protocols for data collection. Results A comprehensive key word search of NLM Gateway's database yielded 9 studies fitting the criteria for inclusion. Data extraction was performed and checked by two of the authors. None of the studies included all outcomes. The results overall, favor handheld computers over paper and pencil for data collection among study participants but the data are not uniform for the different outcomes. Handheld computers appear superior in timeliness of receipt and data handling (four of four studies) and are preferred by most subjects (three of four studies). On the other hand, only one of the trials adequately compared adherence to instructions for recording and submission of data (handheld computers were superior), and comparisons of accuracy were inconsistent between five studies. Conclusion Handhelds are an effective alternative to paper and pencil modes of data collection; they are faster and were preferred by most users. PMID:16737535
Prioritization of candidate disease genes by topological similarity between disease and protein diffusion profiles.

PubMed

Zhu, Jie; Qin, Yufang; Liu, Taigang; Wang, Jun; Zheng, Xiaoqi

2013-01-01

Identification of gene-phenotype relationships is a fundamental challenge in human health clinic. Based on the observation that genes causing the same or similar phenotypes tend to correlate with each other in the protein-protein interaction network, a lot of network-based approaches were proposed based on different underlying models. A recent comparative study showed that diffusion-based methods achieve the state-of-the-art predictive performance. In this paper, a new diffusion-based method was proposed to prioritize candidate disease genes. Diffusion profile of a disease was defined as the stationary distribution of candidate genes given a random walk with restart where similarities between phenotypes are incorporated. Then, candidate disease genes are prioritized by comparing their diffusion profiles with that of the disease. Finally, the effectiveness of our method was demonstrated through the leave-one-out cross-validation against control genes from artificial linkage intervals and randomly chosen genes. Comparative study showed that our method achieves improved performance compared to some classical diffusion-based methods. To further illustrate our method, we used our algorithm to predict new causing genes of 16 multifactorial diseases including Prostate cancer and Alzheimer's disease, and the top predictions were in good consistent with literature reports. Our study indicates that integration of multiple information sources, especially the phenotype similarity profile data, and introduction of global similarity measure between disease and gene diffusion profiles are helpful for prioritizing candidate disease genes. Programs and data are available upon request.

Comparative Analyses of the Teaching Methods and Evaluation Practices in English Subject at Secondary School Certificate (SSC) and General Certificate of Education (GCE O-Level) in Pakistan

ERIC Educational Resources Information Center

Behlol, Malik Ghulam; Anwar, Mohammad

2011-01-01

The study was conducted to compare the teaching methods and evaluation practices in English subject at secondary school certificate (SSC) and general certificate of education GCE-O-level in Pakistan. The population of the study was students, teachers and experts at SSC and 0-level in the Punjab province. Purposive and random sampling techniques…
Classification of LC columns based on the QSRR method and selectivity toward moclobemide and its metabolites.

PubMed

Plenis, Alina; Olędzka, Ilona; Bączek, Tomasz

2013-05-05

This paper focuses on a comparative study of the column classification system based on the quantitative structure-retention relationships (QSRR method) and column performance in real biomedical analysis. The assay was carried out for the LC separation of moclobemide and its metabolites in human plasma, using a set of 24 stationary phases. The QSRR models established for the studied stationary phases were compared with the column test performance results under two chemometric techniques - the principal component analysis (PCA) and the hierarchical clustering analysis (HCA). The study confirmed that the stationary phase classes found closely related by the QSRR approach yielded comparable separation for moclobemide and its metabolites. Therefore, the QSRR method could be considered supportive in the selection of a suitable column for the biomedical analysis offering the selection of similar or dissimilar columns with a relatively higher certainty. Copyright © 2013 Elsevier B.V. All rights reserved.
Study of swelling behavior in ArF resist during development by the QCM method (3): observations of swelling layer elastic modulus

NASA Astrophysics Data System (ADS)

Sekiguchi, Atsushi

2013-03-01

The QCM method allows measurements of impedance, an index of swelling layer viscosity in a photoresist during development. While impedance is sometimes used as a qualitative index of change in the viscosity of the swelling layer, it has to date not been used quantitatively, for data analysis. We explored a method for converting impedance values to elastic modulus (Pa), a coefficient expressing viscosity. Applying this method, we compared changes in the viscosity of the swelling layer in an ArF resist generated during development in a TMAH developing solution and in a TBAH developing solution. This paper reports the results of this comparative study.
A comparative study on methods of improving SCR for ship detection in SAR image

NASA Astrophysics Data System (ADS)

Lang, Haitao; Shi, Hongji; Tao, Yunhong; Ma, Li

2017-10-01

Knowledge about ship positions plays a critical role in a wide range of maritime applications. To improve the performance of ship detector in SAR image, an effective strategy is improving the signal-to-clutter ratio (SCR) before conducting detection. In this paper, we present a comparative study on methods of improving SCR, including power-law scaling (PLS), max-mean and max-median filter (MMF1 and MMF2), method of wavelet transform (TWT), traditional SPAN detector, reflection symmetric metric (RSM), scattering mechanism metric (SMM). The ability of SCR improvement to SAR image and ship detection performance associated with cell- averaging CFAR (CA-CFAR) of different methods are evaluated on two real SAR data.
Evaluation of Two New Smoothing Methods in Equating: The Cubic B-Spline Presmoothing Method and the Direct Presmoothing Method

ERIC Educational Resources Information Center

Cui, Zhongmin; Kolen, Michael J.

2009-01-01

This article considers two new smoothing methods in equipercentile equating, the cubic B-spline presmoothing method and the direct presmoothing method. Using a simulation study, these two methods are compared with established methods, the beta-4 method, the polynomial loglinear method, and the cubic spline postsmoothing method, under three sample…
Generalizing Observational Study Results: Applying Propensity Score Methods to Complex Surveys

PubMed Central

DuGoff, Eva H; Schuler, Megan; Stuart, Elizabeth A

2014-01-01

ObjectiveTo provide a tutorial for using propensity score methods with complex survey data. Data SourcesSimulated data and the 2008 Medical Expenditure Panel Survey. Study DesignUsing simulation, we compared the following methods for estimating the treatment effect: a naïve estimate (ignoring both survey weights and propensity scores), survey weighting, propensity score methods (nearest neighbor matching, weighting, and subclassification), and propensity score methods in combination with survey weighting. Methods are compared in terms of bias and 95 percent confidence interval coverage. In Example 2, we used these methods to estimate the effect on health care spending of having a generalist versus a specialist as a usual source of care. Principal FindingsIn general, combining a propensity score method and survey weighting is necessary to achieve unbiased treatment effect estimates that are generalizable to the original survey target population. ConclusionsPropensity score methods are an essential tool for addressing confounding in observational studies. Ignoring survey weights may lead to results that are not generalizable to the survey target population. This paper clarifies the appropriate inferences for different propensity score methods and suggests guidelines for selecting an appropriate propensity score method based on a researcher’s goal. PMID:23855598
Method and reporting quality in health professions education research: a systematic review.

PubMed

Cook, David A; Levinson, Anthony J; Garside, Sarah

2011-03-01

Studies evaluating reporting quality in health professions education (HPE) research have demonstrated deficiencies, but none have used comprehensive reporting standards. Additionally, the relationship between study methods and effect size (ES) in HPE research is unknown. This review aimed to evaluate, in a sample of experimental studies of Internet-based instruction, the quality of reporting, the relationship between reporting and methodological quality, and associations between ES and study methods. We conducted a systematic search of databases including MEDLINE, Scopus, CINAHL, EMBASE and ERIC, for articles published during 1990-2008. Studies (in any language) quantifying the effect of Internet-based instruction in HPE compared with no intervention or other instruction were included. Working independently and in duplicate, we coded reporting quality using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement, and coded study methods using a modified Newcastle-Ottawa Scale (m-NOS), the Medical Education Research Study Quality Instrument (MERSQI), and the Best Evidence in Medical Education (BEME) global scale. For reporting quality, articles scored a mean±standard deviation (SD) of 51±25% of STROBE elements for the Introduction, 58±20% for the Methods, 50±18% for the Results and 41±26% for the Discussion sections. We found positive associations (all p<0.0001) between reporting quality and MERSQI (ρ=0.64), m-NOS (ρ=0.57) and BEME (ρ=0.58) scores. We explored associations between study methods and knowledge ES by subtracting each study's ES from the pooled ES for studies using that method and comparing these differences between subgroups. Effect sizes in single-group pretest/post-test studies differed from the pooled estimate more than ESs in two-group studies (p=0.013). No difference was found between other study methods (yes/no: representative sample, comparison group from same community, randomised, allocation concealed, participants blinded, assessor blinded, objective assessment, high follow-up). Information is missing from all sections of reports of HPE experiments. Single-group pre-/post-test studies may overestimate ES compared with two-group designs. Other methodological variations did not bias study results in this sample. © Blackwell Publishing Ltd 2011.
Comparative study on the selectivity of various spectrophotometric techniques for the determination of binary mixture of fenbendazole and rafoxanide.

PubMed

Saad, Ahmed S; Attia, Ali K; Alaraki, Manal S; Elzanfaly, Eman S

2015-11-05

Five different spectrophotometric methods were applied for simultaneous determination of fenbendazole and rafoxanide in their binary mixture; namely first derivative, derivative ratio, ratio difference, dual wavelength and H-point standard addition spectrophotometric methods. Different factors affecting each of the applied spectrophotometric methods were studied and the selectivity of the applied methods was compared. The applied methods were validated as per the ICH guidelines and good accuracy; specificity and precision were proven within the concentration range of 5-50 μg/mL for both drugs. Statistical analysis using one-way ANOVA proved no significant differences among the proposed methods for the determination of the two drugs. The proposed methods successfully determined both drugs in laboratory prepared and commercially available binary mixtures, and were found applicable for the routine analysis in quality control laboratories. Copyright © 2015 Elsevier B.V. All rights reserved.
Receiver operating characteristic (ROC) curves: review of methods with applications in diagnostic medicine

NASA Astrophysics Data System (ADS)

Obuchowski, Nancy A.; Bullen, Jennifer A.

2018-04-01

Receiver operating characteristic (ROC) analysis is a tool used to describe the discrimination accuracy of a diagnostic test or prediction model. While sensitivity and specificity are the basic metrics of accuracy, they have many limitations when characterizing test accuracy, particularly when comparing the accuracies of competing tests. In this article we review the basic study design features of ROC studies, illustrate sample size calculations, present statistical methods for measuring and comparing accuracy, and highlight commonly used ROC software. We include descriptions of multi-reader ROC study design and analysis, address frequently seen problems of verification and location bias, discuss clustered data, and provide strategies for testing endpoints in ROC studies. The methods are illustrated with a study of transmission ultrasound for diagnosing breast lesions.
Comparing different methods for assessing contaminant bioavailability during sediment remediation.

PubMed

Jia, Fang; Liao, Chunyang; Xue, Jiaying; Taylor, Allison; Gan, Jay

2016-12-15

Sediment contamination by persistent organic pollutants from historical episodes is widespread and remediation is often needed to clean up severely contaminated sites. Measuring contaminant bioavailability in a before-and-after manner lends to improved assessment of remediation effectiveness. However, a number of bioavailability measurement methods have been developed, posing a challenge in method selection for practitioners. In this study, three different bioavailability measurement methods, i.e., solid phase microextraction (SPME), Tenax desorption, and isotope dilution method (IDM), were compared in evaluating changes in bioavailability of DDT and its degradates in sediment following simulated remediation treatments. When compared to the unamended sediments, all three methods predicted essentially the same degrees of changes in bioavailability after amendment with activated carbon, charcoal or sand. After normalizing over the unamended control, measurements by different methods were linearly correlated with each other, with slopes close to 1. The same observation was further made with a Superfund site marine sediment. This finding suggests that different methods may be used in evaluating remediation efficiency. However, Tenax desorption or IDM consistently offered better sensitivity than SPME in detecting bioavailability changes. Results from this study highlight the value of considering bioavailability when evaluating remediation effectiveness and provide guidance on the selection of bioavailability measurement methods in such assessments. Copyright Â© 2016 Elsevier B.V. All rights reserved.
Real-time fluorescence loop mediated isothermal amplification for the diagnosis of malaria.

PubMed

Lucchi, Naomi W; Demas, Allison; Narayanan, Jothikumar; Sumari, Deborah; Kabanywanyi, Abdunoor; Kachur, S Patrick; Barnwell, John W; Udhayakumar, Venkatachalam

2010-10-29

Molecular diagnostic methods can complement existing tools to improve the diagnosis of malaria. However, they require good laboratory infrastructure thereby restricting their use to reference laboratories and research studies. Therefore, adopting molecular tools for routine use in malaria endemic countries will require simpler molecular platforms. The recently developed loop-mediated isothermal amplification (LAMP) method is relatively simple and can be improved for better use in endemic countries. In this study, we attempted to improve this method for malaria diagnosis by using a simple and portable device capable of performing both the amplification and detection (by fluorescence) of LAMP in one platform. We refer to this as the RealAmp method. Published genus-specific primers were used to test the utility of this method. DNA derived from different species of malaria parasites was used for the initial characterization. Clinical samples of P. falciparum were used to determine the sensitivity and specificity of this system compared to microscopy and a nested PCR method. Additionally, directly boiled parasite preparations were compared with a conventional DNA isolation method. The RealAmp method was found to be simple and allowed real-time detection of DNA amplification. The time to amplification varied but was generally less than 60 minutes. All human-infecting Plasmodium species were detected. The sensitivity and specificity of RealAmp in detecting P. falciparum was 96.7% and 91.7% respectively, compared to microscopy and 98.9% and 100% respectively, compared to a standard nested PCR method. In addition, this method consistently detected P. falciparum from directly boiled blood samples. This RealAmp method has great potential as a field usable molecular tool for diagnosis of malaria. This tool can provide an alternative to conventional PCR based diagnostic methods for field use in clinical and operational programs.
Methods to Estimate the Variance of Some Indices of the Signal Detection Theory: A Simulation Study

ERIC Educational Resources Information Center

Suero, Manuel; Privado, Jesús; Botella, Juan

2017-01-01

A simulation study is presented to evaluate and compare three methods to estimate the variance of the estimates of the parameters d and "C" of the signal detection theory (SDT). Several methods have been proposed to calculate the variance of their estimators, "d'" and "c." Those methods have been mostly assessed by…
Cluster-randomized Studies in Educational Research: Principles and Methodological Aspects

PubMed Central

Dreyhaupt, Jens; Mayer, Benjamin; Keis, Oliver; Öchsner, Wolfgang; Muche, Rainer

2017-01-01

An increasing number of studies are being performed in educational research to evaluate new teaching methods and approaches. These studies could be performed more efficiently and deliver more convincing results if they more strictly applied and complied with recognized standards of scientific studies. Such an approach could substantially increase the quality in particular of prospective, two-arm (intervention) studies that aim to compare two different teaching methods. A key standard in such studies is randomization, which can minimize systematic bias in study findings; such bias may result if the two study arms are not structurally equivalent. If possible, educational research studies should also achieve this standard, although this is not yet generally the case. Some difficulties and concerns exist, particularly regarding organizational and methodological aspects. An important point to consider in educational research studies is that usually individuals cannot be randomized, because of the teaching situation, and instead whole groups have to be randomized (so-called “cluster randomization”). Compared with studies with individual randomization, studies with cluster randomization normally require (significantly) larger sample sizes and more complex methods for calculating sample size. Furthermore, cluster-randomized studies require more complex methods for statistical analysis. The consequence of the above is that a competent expert with respective special knowledge needs to be involved in all phases of cluster-randomized studies. Studies to evaluate new teaching methods need to make greater use of randomization in order to achieve scientifically convincing results. Therefore, in this article we describe the general principles of cluster randomization and how to implement these principles, and we also outline practical aspects of using cluster randomization in prospective, two-arm comparative educational research studies. PMID:28584874
Cluster-randomized Studies in Educational Research: Principles and Methodological Aspects.

PubMed

Dreyhaupt, Jens; Mayer, Benjamin; Keis, Oliver; Öchsner, Wolfgang; Muche, Rainer

2017-01-01

An increasing number of studies are being performed in educational research to evaluate new teaching methods and approaches. These studies could be performed more efficiently and deliver more convincing results if they more strictly applied and complied with recognized standards of scientific studies. Such an approach could substantially increase the quality in particular of prospective, two-arm (intervention) studies that aim to compare two different teaching methods. A key standard in such studies is randomization, which can minimize systematic bias in study findings; such bias may result if the two study arms are not structurally equivalent. If possible, educational research studies should also achieve this standard, although this is not yet generally the case. Some difficulties and concerns exist, particularly regarding organizational and methodological aspects. An important point to consider in educational research studies is that usually individuals cannot be randomized, because of the teaching situation, and instead whole groups have to be randomized (so-called "cluster randomization"). Compared with studies with individual randomization, studies with cluster randomization normally require (significantly) larger sample sizes and more complex methods for calculating sample size. Furthermore, cluster-randomized studies require more complex methods for statistical analysis. The consequence of the above is that a competent expert with respective special knowledge needs to be involved in all phases of cluster-randomized studies. Studies to evaluate new teaching methods need to make greater use of randomization in order to achieve scientifically convincing results. Therefore, in this article we describe the general principles of cluster randomization and how to implement these principles, and we also outline practical aspects of using cluster randomization in prospective, two-arm comparative educational research studies.
Effectiveness of pharmacovigilance training of general practitioners: a retrospective cohort study in the Netherlands comparing two methods.

PubMed

Gerritsen, Roald; Faddegon, Hans; Dijkers, Fred; van Grootheest, Kees; van Puijenbroek, Eugène

2011-09-01

Spontaneous reporting is a cornerstone of pharmacovigilance. Unfamiliarity with the reporting of suspected adverse drug reactions (ADRs) is a major factor leading to not reporting these events. Medical education may promote more effective reporting. Numerous changes have been implemented in medical education over the last decade, with a shift in training methods from those aimed predominantly at the transfer of knowledge towards those that are more practice based and skill oriented. It is conceivable that these changes have an impact on pharmacovigilance training in vocational training programmes. Therefore, this study compares the effectiveness of a skill-oriented, practice-based pharmacovigilance training method, with a traditional, lecture-based pharmacovigilance training method in the vocational training of general practitioners (GPs). The traditional, lecture-based method is common practice in the Netherlands. The purpose of this study was to establish whether the use of a practice-based, skill-oriented method in pharmacovigilance training during GP traineeship leads to an increase of reported ADRs after completion of this traineeship, compared with a lecture-based method. We also investigated whether the applied training method has an impact on the documentation level of the reports and on the number of unlabelled events reported. A retrospective cohort study. The number of ADR reports submitted to the Netherlands Pharmacovigilance Centre Lareb (between January 2006 and October 2010) after completion of GP vocational training was compared between the two groups. Documentation level of the reports and the number of labelled/unlabelled events reported were also compared. The practice-based cohort reported 32 times after completion of training (124 subjects, 6.8 reports per 1000 months of follow-up; total follow-up of 4704 months). The lecture-based cohort reported 12 times after training (135 subjects, 2.1 reports per 1000 months of follow-up; total follow-up of 5824 months) [odds ratio 2.9; 95% CI 1.4, 6.1]. Reports from GPs with practice-based training had a better documentation grade than those from GPs with lecture-based training, and more often concerned unlabelled events. The practice-based method resulted in significantly more and better-documented reports and more often concerned unlabelled events than the lecture-based method. This effect persisted and did not appear to diminish over time.
Using Virtual Social Networks for Case Finding in Clinical Studies: An Experiment from Adolescence, Brain, Cognition, and Diabetes Study.

PubMed

Pourabbasi, Ata; Farzami, Jalal; Shirvani, Mahbubeh-Sadat Ebrahimnegad; Shams, Amir Hossein; Larijani, Bagher

2017-01-01

One of the main usages of social networks in clinical studies is facilitating the process of sampling and case finding for scientists. The main focus of this study is on comparing two different methods of sampling through phone calls and using social network, for study purposes. One of the researchers started calling 214 families of children with diabetes during 90 days. After this period, phone calls stopped, and the team started communicating with families through telegram, a virtual social network for 30 days. The number of children who participated in the study was evaluated. Although the telegram method was 60 days shorter than the phone call method, researchers found that the number of participants from telegram (17.6%) did not have any significant differences compared with the ones being phone called (12.9%). Using social networks can be suggested as a beneficial method for local researchers who look for easier sampling methods, winning their samples' trust, following up with the procedure, and an easy-access database.
A Comparative Analysis of Method Books for Class Jazz Instruction

ERIC Educational Resources Information Center

Watson, Kevin E.

2017-01-01

The purpose of this study was to analyze and compare instructional topics and teaching approaches included in selected class method books for jazz pedagogy through content analysis methodology. Frequency counts for the number of pages devoted to each defined instructional content category were compiled and percentages of pages allotted to each…
Comparing Propensity Score Methods in Balancing Covariates and Recovering Impact in Small Sample Educational Program Evaluations

ERIC Educational Resources Information Center

Stone, Clement A.; Tang, Yun

2013-01-01

Propensity score applications are often used to evaluate educational program impact. However, various options are available to estimate both propensity scores and construct comparison groups. This study used a student achievement dataset with commonly available covariates to compare different propensity scoring estimation methods (logistic…
PRELIMINARY COMPARATIVE STUDY OF METHODS TO EXTRACT VIRUS FROM RAW AND PROCESSED SEWAGE SLUDGES

EPA Science Inventory

Two simple virus extraction techniques were compared to an EPA standard method for detection of human enteric viruses in raw sewage sludge and class A biosolids. The techniques were used to detect both indigenous and seeded virus from a plant that distributes class A material pr...
Programmed Instruction in Secondary Education: A Meta-Analysis of the Impact of Class Size on Its Effectiveness.

ERIC Educational Resources Information Center

Boden, Andrea; Archwamety, Teara; McFarland, Max

This review used meta-analytic techniques to integrate findings from 30 independent studies that compared programmed instruction to conventional methods of instruction at the secondary level. The meta-analysis demonstrated that programmed instruction resulted in higher achievement when compared to conventional methods of instruction (average…

Effectiveness and Efficiency of Flashcard Drill Instructional Methods on Urban First-Graders' Word Recognition, Acquisition, Maintenance, and Generalization

ERIC Educational Resources Information Center

Nist, Lindsay; Joseph, Laurice M.

2008-01-01

This investigation built upon previous studies that compared effectiveness and efficiency among instructional methods. Instructional effectiveness and efficiency were compared among three conditions: an incremental rehearsal, a more challenging ratio of known to unknown interspersal word procedure, and a traditional drill and practice flashcard…
Comparison of Performance Due to Guided Hyperlearning, Unguided Hyperlearning, and Conventional Learning in Mathematics: An Empirical Study

ERIC Educational Resources Information Center

Fathurrohman, Maman; Porter, Anne; Worthy, Annette L.

2014-01-01

In this paper, the use of guided hyperlearning, unguided hyperlearning, and conventional learning methods in mathematics are compared. The design of the research involved a quasi-experiment with a modified single-factor multiple treatment design comparing the three learning methods, guided hyperlearning, unguided hyperlearning, and conventional…
Comparative In Vitro Efficacy of Doripenem and Imipenem Against Multi-Drug Resistant Pseudomonas aeruginosa.

PubMed

Wali, Nadia; Mirza, Irfan Ali

2016-04-01

To compare the in vitro efficacy of doripenem and imipenem against multi-drug resistant (MDR) Pseudomonas aeruginosa from various clinical specimens. Descriptive cross-sectional study. Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi, from November 2012 to November 2013. MDR Pseudomonas aeruginosa isolates from various clinical samples were included in the study. Susceptibility of Pseudomonas aeruginosa against doripenem and imipenem was performed by E-test strip and agar dilution methods. The results were interpreted as recommended by Clinical Laboratory Standard Institute (CLSI) guidelines. The maximum number of Pseudomonas aeruginosa were isolated from pure pus and pus swabs. In vitro efficacy of doripenem was found to be more effective as compared to imipenem against MDR Pseudomonas aeruginosa with both E-test strip and agar dilution methods. Overall, p-values of 0.014 and 0.037 were observed when susceptibility patterns of doripenem and imipenem were evaluated with E-test strip and agar dilution methods. In vitro efficacy of doripenem was found to be better against MDR Pseudomonas aeruginosaas compared to imipenem when tested by both E-test and agar dilution methods.
[A comparative evaluation of the methods for determining nitrogen dioxide in an industrial environment].

PubMed

Panev, T

1991-01-01

The present work has the purpose to make a comparative evaluation of the different types detector tubes--for analysis, long-term and passive for determination of NO2 and the results to be compared, with those received by the spectrophotometric method and the reagent of Zaltsman. Studies were performed in the hall of the garage for repair of diesel buses during one working shift. The results point out that the analysing tubes for NO2 give good results with the spectrophotometric method. The measured average-shift concentrations of NO2 by long-term and passive tubes are juxtaposed with the average-received values with the analytical tubes and with the analytical method.
The intervals method: a new approach to analyse finite element outputs using multivariate statistics

PubMed Central

De Esteban-Trivigno, Soledad; Püschel, Thomas A.; Fortuny, Josep

2017-01-01

Background In this paper, we propose a new method, named the intervals’ method, to analyse data from finite element models in a comparative multivariate framework. As a case study, several armadillo mandibles are analysed, showing that the proposed method is useful to distinguish and characterise biomechanical differences related to diet/ecomorphology. Methods The intervals’ method consists of generating a set of variables, each one defined by an interval of stress values. Each variable is expressed as a percentage of the area of the mandible occupied by those stress values. Afterwards these newly generated variables can be analysed using multivariate methods. Results Applying this novel method to the biological case study of whether armadillo mandibles differ according to dietary groups, we show that the intervals’ method is a powerful tool to characterize biomechanical performance and how this relates to different diets. This allows us to positively discriminate between specialist and generalist species. Discussion We show that the proposed approach is a useful methodology not affected by the characteristics of the finite element mesh. Additionally, the positive discriminating results obtained when analysing a difficult case study suggest that the proposed method could be a very useful tool for comparative studies in finite element analysis using multivariate statistical approaches. PMID:29043107
[Study on trace elements of lake sediments by ICP-AES and XRF core scanning].

PubMed

Cheng, Ai-Ying; Yu, Jun-Qing; Gao, Chun-Liang; Zhang, Li-Sha; He, Xian-Hu

2013-07-01

It is the first time to study sediment of Toson lake in Qaidam Basin. Trace elements including Cd, Cr, Cu, Zn and Pb in lake sediment were measured by ICP-AES method, studied and optimized from different resolution methods respectively, and finally determined a optimum pretreatment system for sediment of Toson lake, namely, HCl-HNO3-HF-HClO4-H2O2 system in the proportions of 5 : 5 : 5 : 1 : 1 was determined. At the same time, the data measured by XRF core scanning were compared, the use of moisture content correction method was analyzed, and the influence of the moisture content on the scanning method was discussed. The results showed that, compared to the background value, the contents of Cd and Zn were a little higher, the content of Cr, Cu and Pb was within the background value limits. XRF core scanning was controlled by sediment elements as well as water content in sediment to some extent. The results by the two methods showed a significant positive correlation, with the correlation coefficient up to 0.673-0.925, and they have a great comparability.
[Comparative study of diagnostic methods for visceral leishmaniasis in dogs from Ilha Solteira, SP].

PubMed

de Assis, Juliana; de Queiroz, Nina Marí Gual Pimenta; da Silveira, Rita de Cássia Vieira; Nunes, Cáris Maroni; Oliveira, Trícia Maria Ferreira de Sousa; Junior, Antonio Carlos Faconti de Noronha; Neves, Maria Francisca; Machado, Rosangela Zacarias; Buzetti, Wilma Aparecida Starke

2010-01-01

The purpose of the present work was a comparative study of diagnostic methods for Canine Visceral Leishmaniasis (CVL) using serological methods, enzyme-linked immunosorbent assay (ELISA) and indirect fluorescent antibody test (IFAT), histochemical (HE) and immunohistochemical (IMHC) tests using spleen, lymph node and liver canine tissues. In addition, Polymerase Chain Reaction (PCR) was done in blood and in tissues in order to compare and confirm no conclusive and negative diagnosis by the methods above. For this study, 34 dogs were divided according to clinical signs in asymptomatic, oligosymptomatic and polisymptomatic Leishmania-infected dogs euthanized by Zoonotic Disease Control Center (CCZ) from Ilha Solteira, SP, Brazil. The positivism indexes of ELISA, IMHC, IFAT and HE were 65.0, 62.0, 56.0 and 56.0%, respectively with the highest numbers of positive dogs in polisymptomatic (92.0%) followed by oligosymptomatic (57.0%) and asymptomatic dogs (12.5%). Furthermore, PCR confirmed the positive results and detected DNA in tissues from 100% of negative dogs and 89.0% suspects raising the animal positivism index up to 97.0%. In conclusion, PCR was the most sensitive and a valuable method for a definitive CVL diagnosis.
A new method to address verification bias in studies of clinical screening tests: cervical cancer screening assays as an example.

PubMed

Xue, Xiaonan; Kim, Mimi Y; Castle, Philip E; Strickler, Howard D

2014-03-01

Studies to evaluate clinical screening tests often face the problem that the "gold standard" diagnostic approach is costly and/or invasive. It is therefore common to verify only a subset of negative screening tests using the gold standard method. However, undersampling the screen negatives can lead to substantial overestimation of the sensitivity and underestimation of the specificity of the diagnostic test. Our objective was to develop a simple and accurate statistical method to address this "verification bias." We developed a weighted generalized estimating equation approach to estimate, in a single model, the accuracy (eg, sensitivity/specificity) of multiple assays and simultaneously compare results between assays while addressing verification bias. This approach can be implemented using standard statistical software. Simulations were conducted to assess the proposed method. An example is provided using a cervical cancer screening trial that compared the accuracy of human papillomavirus and Pap tests, with histologic data as the gold standard. The proposed approach performed well in estimating and comparing the accuracy of multiple assays in the presence of verification bias. The proposed approach is an easy to apply and accurate method for addressing verification bias in studies of multiple screening methods. Copyright © 2014 Elsevier Inc. All rights reserved.
Five methods of breast volume measurement: a comparative study of measurements of specimen volume in 30 mastectomy cases.

PubMed

Kayar, Ragip; Civelek, Serdar; Cobanoglu, Murat; Gungor, Osman; Catal, Hidayet; Emiroglu, Mustafa

2011-03-27

To compare breast volume measurement techniques in terms of accuracy, convenience, and cost. Breast volumes of 30 patients who were scheduled to undergo total mastectomy surgery were measured preoperatively by using five different methods (mammography, anatomic [anthropometric], thermoplastic casting, the Archimedes procedure, and the Grossman-Roudner device). Specimen volume after total mastectomy was measured in each patient with the water displacement method (Archimedes). The results were compared statistically with the values obtained by the five different methods. The mean mastectomy specimen volume was 623.5 (range 150-1490) mL. The breast volume values were established to be 615.7 mL (r = 0.997) with the mammographic method, 645.4 mL (r = 0.975) with the anthropometric method, 565.8 mL (r = 0.934) with the Grossman-Roudner device, 583.2 mL (r = 0.989) with the Archimedes procedure, and 544.7 mL (r = 0.94) with the casting technique. Examination of r values revealed that the most accurate method was mammography for all volume ranges, followed by the Archimedes method. The present study demonstrated that the most accurate method of breast volume measurement is mammography, followed by the Archimedes method. However, when patient comfort, ease of application, and cost were taken into consideration, the Grossman-Roudner device and anatomic measurement were relatively less expensive, and easier methods with an acceptable degree of accuracy.
Elongation measurement using 1-dimensional image correlation method

NASA Astrophysics Data System (ADS)

Phongwisit, Phachara; Kamoldilok, Surachart; Buranasiri, Prathan

2016-11-01

Aim of this paper was to study, setup, and calibrate an elongation measurement by using 1- Dimensional Image Correlation method (1-DIC). To confirm our method and setup correctness, we need calibration with other methods. In this paper, we used a small spring as a sample to find a result in terms of spring constant. With a fundamental of Image Correlation method, images of formed and deformed samples were compared to understand the difference between deformed process. By comparing the location of reference point on both image's pixel, the spring's elongation were calculated. Then, the results have been compared with the spring constants, which were found from Hooke's law. The percentage of 5 percent error has been found. This DIC method, then, would be applied to measure the elongation of some different kinds of small fiber samples.
Robust estimation of pulse wave transit time using group delay.

PubMed

Meloni, Antonella; Zymeski, Heather; Pepe, Alessia; Lombardi, Massimo; Wood, John C

2014-03-01

To evaluate the efficiency of a novel transit time (Δt) estimation method from cardiovascular magnetic resonance flow curves. Flow curves were estimated from phase contrast images of 30 patients. Our method (TT-GD: transit time group delay) operates in the frequency domain and models the ascending aortic waveform as an input passing through a discrete-component "filter," producing the observed descending aortic waveform. The GD of the filter represents the average time delay (Δt) across individual frequency bands of the input. This method was compared with two previously described time-domain methods: TT-point using the half-maximum of the curves and TT-wave using cross-correlation. High temporal resolution flow images were studied at multiple downsampling rates to study the impact of differences in temporal resolution. Mean Δts obtained with the three methods were comparable. The TT-GD method was the most robust to reduced temporal resolution. While the TT-GD and the TT-wave produced comparable results for velocity and flow waveforms, the TT-point resulted in significant shorter Δts when calculated from velocity waveforms (difference: 1.8±2.7 msec; coefficient of variability: 8.7%). The TT-GD method was the most reproducible, with an intraobserver variability of 3.4% and an interobserver variability of 3.7%. Compared to the traditional TT-point and TT-wave methods, the TT-GD approach was more robust to the choice of temporal resolution, waveform type, and observer. Copyright © 2013 Wiley Periodicals, Inc.
Correcting for batch effects in case-control microbiome studies

PubMed Central

Gibbons, Sean M.; Duvallet, Claire

2018-01-01

High-throughput data generation platforms, like mass-spectrometry, microarrays, and second-generation sequencing are susceptible to batch effects due to run-to-run variation in reagents, equipment, protocols, or personnel. Currently, batch correction methods are not commonly applied to microbiome sequencing datasets. In this paper, we compare different batch-correction methods applied to microbiome case-control studies. We introduce a model-free normalization procedure where features (i.e. bacterial taxa) in case samples are converted to percentiles of the equivalent features in control samples within a study prior to pooling data across studies. We look at how this percentile-normalization method compares to traditional meta-analysis methods for combining independent p-values and to limma and ComBat, widely used batch-correction models developed for RNA microarray data. Overall, we show that percentile-normalization is a simple, non-parametric approach for correcting batch effects and improving sensitivity in case-control meta-analyses. PMID:29684016
A quantitative analysis of qualitative studies in clinical journals for the 2000 publishing year

PubMed Central

McKibbon, Kathleen Ann; Gadd, Cynthia S

2004-01-01

Background Quantitative studies are becoming more recognized as important to understanding health care with all of its richness and complexities. The purpose of this descriptive survey was to provide a quantitative evaluation of the qualitative studies published in 170 core clinical journals for 2000. Methods All identified studies that used qualitative methods were reviewed to ascertain which clinical journals publish qualitative studies and to extract research methods, content (persons and health care issues studied), and whether mixed methods (quantitative and qualitative methods) were used. Results 60 330 articles were reviewed. 355 reports of original qualitative studies and 12 systematic review articles were identified in 48 journals. Most of the journals were in the discipline of nursing. Only 4 of the most highly cited health care journals, based on ISI Science Citation Index (SCI) Impact Factors, published qualitative studies. 37 of the 355 original reports used both qualitative and quantitative (mixed) methods. Patients and non-health care settings were the most common groups of people studied. Diseases and conditions were cancer, mental health, pregnancy and childbirth, and cerebrovascular disease with many other diseases and conditions represented. Phenomenology and grounded theory were commonly used; substantial ethnography was also present. No substantial differences were noted for content or methods when articles published in all disciplines were compared with articles published in nursing titles or when studies with mixed methods were compared with studies that included only qualitative methods. Conclusions The clinical literature includes many qualitative studies although they are often published in nursing journals or journals with low SCI Impact Factor journals. Many qualitative studies incorporate both qualitative and quantitative methods. PMID:15271221
Comparison of haemoglobin estimates using direct & indirect cyanmethaemoglobin methods.

PubMed

Bansal, Priyanka Gupta; Toteja, Gurudayal Singh; Bhatia, Neena; Gupta, Sanjeev; Kaur, Manpreet; Adhikari, Tulsi; Garg, Ashok Kumar

2016-10-01

Estimation of haemoglobin is the most widely used method to assess anaemia. Although direct cyanmethaemoglobin method is the recommended method for estimation of haemoglobin, but it may not be feasible under field conditions. Hence, the present study was undertaken to compare indirect cyanmethaemoglobin method against the conventional direct method for haemoglobin estimation. Haemoglobin levels were estimated for 888 adolescent girls aged 11-18 yr residing in an urban slum in Delhi by both direct and indirect cyanmethaemoglobin methods, and the results were compared. The mean haemoglobin levels for 888 whole blood samples estimated by direct and indirect cyanmethaemoglobin method were 116.1 ± 12.7 and 110.5 ± 12.5 g/l, respectively, with a mean difference of 5.67 g/l (95% confidence interval: 5.45 to 5.90, P<0.001); which is equivalent to 0.567 g%. The prevalence of anaemia was reported as 59.6 and 78.2 per cent by direct and indirect methods, respectively. Sensitivity and specificity of indirect cyanmethaemoglobin method were 99.2 and 56.4 per cent, respectively. Using regression analysis, prediction equation was developed for indirect haemoglobin values. The present findings revealed that indirect cyanmethaemoglobin method overestimated the prevalence of anaemia as compared to the direct method. However, if a correction factor is applied, indirect method could be successfully used for estimating true haemoglobin level. More studies should be undertaken to establish agreement and correction factor between direct and indirect cyanmethaemoglobin methods.
Observational methods in comparative effectiveness research.

PubMed

Concato, John; Lawler, Elizabeth V; Lew, Robert A; Gaziano, J Michael; Aslan, Mihaela; Huang, Grant D

2010-12-01

Comparative effectiveness research (CER) may be defined informally as an assessment of available options for treating specific medical conditions in selected groups of patients. In this context, the most prominent features of CER are the various patient populations, medical ailments, and treatment options involved in any particular project. Yet, each research investigation also has a corresponding study design or "architecture," and in patient-oriented research a common distinction used to describe such designs are randomized controlled trials (RCTs) versus observational studies. The purposes of this overview, with regard to CER, are to (1) understand how observational studies can provide accurate results, comparable to RCTs; (2) recognize strategies used in selected newer methods for conducting observational studies; (3) review selected observational studies from the Veterans Health Administration; and (4) appreciate the importance of fundamental methodological principles when conducting or evaluating individual studies. Published by Elsevier Inc.
Comparison of cell counting methods in rodent pulmonary toxicity studies: automated and manual protocols and considerations for experimental design

PubMed Central

Zeidler-Erdely, Patti C.; Antonini, James M.; Meighan, Terence G.; Young, Shih-Houng; Eye, Tracy J.; Hammer, Mary Ann; Erdely, Aaron

2016-01-01

Pulmonary toxicity studies often use bronchoalveolar lavage (BAL) to investigate potential adverse lung responses to a particulate exposure. The BAL cellular fraction is counted, using automated (i.e. Coulter Counter®), flow cytometry or manual (i.e. hemocytometer) methods, to determine inflammatory cell influx. The goal of the study was to compare the different counting methods to determine which is optimal for examining BAL cell influx after exposure by inhalation or intratracheal instillation (ITI) to different particles with varying inherent pulmonary toxicities in both rat and mouse models. General findings indicate that total BAL cell counts using the automated and manual methods tended to agree after inhalation or ITI exposure to particle samples that are relatively nontoxic or at later time points after exposure to a pneumotoxic particle when the response resolves. However, when the initial lung inflammation and cytotoxicity was high after exposure to a pneumotoxic particle, significant differences were observed when comparing cell counts from the automated, flow cytometry and manual methods. When using total BAL cell count for differential calculations from the automated method, depending on the cell diameter size range cutoff, the data suggest that the number of lung polymorphonuclear leukocytes (PMN) varies. Importantly, the automated counts, regardless of the size cutoff, still indicated a greater number of total lung PMN when compared with the manual method, which agreed more closely with flow cytometry. The results suggest that either the manual method or flow cytometry would be better suited for BAL studies where cytotoxicity is an unknown variable. PMID:27251196
Comparison of cell counting methods in rodent pulmonary toxicity studies: automated and manual protocols and considerations for experimental design.

PubMed

Zeidler-Erdely, Patti C; Antonini, James M; Meighan, Terence G; Young, Shih-Houng; Eye, Tracy J; Hammer, Mary Ann; Erdely, Aaron

2016-08-01

Pulmonary toxicity studies often use bronchoalveolar lavage (BAL) to investigate potential adverse lung responses to a particulate exposure. The BAL cellular fraction is counted, using automated (i.e. Coulter Counter®), flow cytometry or manual (i.e. hemocytometer) methods, to determine inflammatory cell influx. The goal of the study was to compare the different counting methods to determine which is optimal for examining BAL cell influx after exposure by inhalation or intratracheal instillation (ITI) to different particles with varying inherent pulmonary toxicities in both rat and mouse models. General findings indicate that total BAL cell counts using the automated and manual methods tended to agree after inhalation or ITI exposure to particle samples that are relatively nontoxic or at later time points after exposure to a pneumotoxic particle when the response resolves. However, when the initial lung inflammation and cytotoxicity was high after exposure to a pneumotoxic particle, significant differences were observed when comparing cell counts from the automated, flow cytometry and manual methods. When using total BAL cell count for differential calculations from the automated method, depending on the cell diameter size range cutoff, the data suggest that the number of lung polymorphonuclear leukocytes (PMN) varies. Importantly, the automated counts, regardless of the size cutoff, still indicated a greater number of total lung PMN when compared with the manual method, which agreed more closely with flow cytometry. The results suggest that either the manual method or flow cytometry would be better suited for BAL studies where cytotoxicity is an unknown variable.
Temperature Dependence of Errors in Parameters Derived from Van't Hoff Studies.

ERIC Educational Resources Information Center

Dec, Steven F.; Gill, Stanley J.

1985-01-01

The method of Clarke and Glew is broadly applicable to studies of the temperature dependence of equilibrium constant measurements. The method is described and examples of its use in comparing calorimetric results and temperature dependent gas solubility studies are provided. (JN)
Research design and statistical methods in Pakistan Journal of Medical Sciences (PJMS)

PubMed Central

Akhtar, Sohail; Shah, Syed Wadood Ali; Rafiq, M.; Khan, Ajmal

2016-01-01

Objective: This article compares the study design and statistical methods used in 2005, 2010 and 2015 of Pakistan Journal of Medical Sciences (PJMS). Methods: Only original articles of PJMS were considered for the analysis. The articles were carefully reviewed for statistical methods and designs, and then recorded accordingly. The frequency of each statistical method and research design was estimated and compared with previous years. Results: A total of 429 articles were evaluated (n=74 in 2005, n=179 in 2010, n=176 in 2015) in which 171 (40%) were cross-sectional and 116 (27%) were prospective study designs. A verity of statistical methods were found in the analysis. The most frequent methods include: descriptive statistics (n=315, 73.4%), chi-square/Fisher’s exact tests (n=205, 47.8%) and student t-test (n=186, 43.4%). There was a significant increase in the use of statistical methods over time period: t-test, chi-square/Fisher’s exact test, logistic regression, epidemiological statistics, and non-parametric tests. Conclusion: This study shows that a diverse variety of statistical methods have been used in the research articles of PJMS and frequency improved from 2005 to 2015. However, descriptive statistics was the most frequent method of statistical analysis in the published articles while cross-sectional study design was common study design. PMID:27022365
A meta-analysis of in vitro antibiotic synergy against Acinetobacter baumannii.

PubMed

March, Gabriel A; Bratos, Miguel A

2015-12-01

The aim of the work was to describe the different in vitro models for testing synergism of antibiotics and gather the results of antibiotic synergy against multidrug-resistant Acinetobacter baumannii (MDR-Ab). The different original articles were obtained from different web sites. In order to compare the results obtained by the different methods for synergy testing, the Pearson chi-square and the Fischer tests were used. Moreover, non-parametric chi-square test was used in order to compare the frequency distribution in each analysed manuscript. In the current meta-analysis 24 manuscripts, which encompassed 2016 tests of in vitro synergism of different antimicrobials against MDR-Ab, were revised. Checkerboard synergy testing was used in 11 studies, which encompasses 1086 tests (53.9%); time-kill assays were applied in 12 studies, which encompass 359 tests (17.8%); gradient diffusion methods were used in seven studies, encompassing 293 tests (14.5%). And, finally, time-kill plus checkerboard were applied in two studies, encompassing 278 tests (13.8%). By comparing these data, checkerboard and time-kill methods were significantly more used than gradient diffusion methods (p<0.005). Regarding synergy rates obtained on the basis of the applied method, checkerboard provided 227 tests (20.9%) with a synergistic effect; time-kill assays yielded 222 tests (61.8%) with a synergistic effect; gradient diffusion methods only provided 29 tests (9.9%) with a synergistic effect; and, finally, time-kill plus checkerboard yielded just 15 tests (5.4%) with a synergistic effect. When comparing these percentages, synergy rates reported by time-kill methods were significantly higher than that obtained by checkerboard and gradient diffusion methods (p<0.005). On the basis of the revised data, the combinations of a bactericidal antibiotic plus Tigecycline, Vancomycin or Teicoplanin are not recommended. The best combinations of antibiotics are those which include bactericidal antibiotics such as Carbapenems, Fosfomycin, Amikacin, Polymyxins, Rifampicin and Ampicillin/Sulbactam. Copyright © 2015. Published by Elsevier B.V.

Recruitment bias in chronic pain research: whiplash as a model.

PubMed

Nijs, Jo; Inghelbrecht, Els; Daenen, Liesbeth; Hachimi-Idrissi, Said; Hens, Luc; Willems, Bert; Roussel, Nathalie; Cras, Patrick; Wouters, Kristien; Bernheim, Jan

2011-11-01

In science findings which cannot be extrapolated to other settings are of little value. Recruitment methods vary widely across chronic whiplash studies, but it remains unclear whether this generates recruitment bias. The present study aimed to examine whether the recruitment method accounts for differences in health status, social support, and personality traits in patients with chronic whiplash-associated disorders (WAD). Two different recruitment methods were compared: recruiting patients through a local whiplash patient support group (group 1) and local hospital emergency department (group 2). The participants (n=118) filled in a set of questionnaires: the Neck Disability Index, Medical Outcome Study Short-Form General Health Survey, Anamnestic Comparative Self-Assessment measure of overall well-being, Symptom Checklist-90, Dutch Personality Questionnaire, and the Social Support List. The recruitment method (either through the local emergency department or patient support group) accounted for the differences in insufficiency, somatization, disability, quality of life, self-satisfaction, and dominance (all p values <.01). The recruitment methods generated chronic WAD patients comparable for psychoneurotism, social support, self-sufficiency, (social) inadequacy, rigidity, and resentment (p>.01). The recruitment of chronic WAD patients solely through patient support groups generates bias with respect to the various aspects of health status and personality, but not social support. In order to enhance the external validity of study findings, chronic WAD studies should combine a variety of recruitment procedures.
Effectiveness of team-based learning methodology in teaching transfusion medicine to medical undergraduates in third semester: A comparative study.

PubMed

Doshi, Neena Piyush

2017-01-01

Team-based learning (TBL) combines small and large group learning by incorporating multiple small groups in a large group setting. It is a teacher-directed method that encourages student-student interaction. This study compares student learning and teaching satisfaction between conventional lecture and TBL in the subject of pathology. The present study is aimed to assess the effectiveness of TBL method of teaching over the conventional lecture. The present study was conducted in the Department of Pathology, GMERS Medical College and General Hospital, Gotri, Vadodara, Gujarat. The study population comprised 126 students of second-year MBBS, in their third semester of the academic year 2015-2016. "Hemodynamic disorders" were taught by conventional method and "transfusion medicine" by TBL method. Effectiveness of both the methods was assessed. A posttest multiple choice question was conducted at the end of "hemodynamic disorders." Assessment of TBL was based on individual score, team score, and each member's contribution to the success of the team. The individual score and overall score were compared with the posttest score on "hemodynamic disorders." A feedback was taken from the students regarding their experience with TBL. Tukey's multiple comparisons test and ANOVA summary were used to find the significance of scores between didactic and TBL methods. Student feedback was taken using "Student Satisfaction Scale" based on Likert scoring method. The mean of student scores by didactic, Individual Readiness Assurance Test (score "A"), and overall (score "D") was 49.8% (standard deviation [SD]-14.8), 65.6% (SD-10.9), and 65.6% (SD-13.8), respectively. The study showed positive educational outcome in terms of knowledge acquisition, participation and engagement, and team performance with TBL.
Interactive Learning in the Classroom: Is Student Response Method Related to Performance?

ERIC Educational Resources Information Center

Elicker, Joelle D.; McConnell, Nicole L.

2011-01-01

This study examined three methods of responding to in-class multiple-choice concept questions in an Introduction to Psychology course. Specifically, this study compared exam performance and student reactions using three methods of responding to concept questions: (a) a technology-based network system, (b) hand-held flashcards, and (c) hand…
Comparison of weighed food record procedures for the reference methods in two validation studies of food frequency questionnaires.

PubMed

Ishii, Yuri; Ishihara, Junko; Takachi, Ribeka; Shinozawa, Yurie; Imaeda, Nahomi; Goto, Chiho; Wakai, Kenji; Takahashi, Toshiaki; Iso, Hiroyasu; Nakamura, Kazutoshi; Tanaka, Junta; Shimazu, Taichi; Yamaji, Taiki; Sasazuki, Shizuka; Sawada, Norie; Iwasaki, Motoki; Mikami, Haruo; Kuriki, Kiyonori; Naito, Mariko; Okamoto, Naoko; Kondo, Fumi; Hosono, Satoyo; Miyagawa, Naoko; Ozaki, Etsuko; Katsuura-Kamano, Sakurako; Ohnaka, Keizo; Nanri, Hinako; Tsunematsu-Nakahata, Noriko; Kayama, Takamasa; Kurihara, Ayako; Kojima, Shiomi; Tanaka, Hideo; Tsugane, Shoichiro

2017-07-01

Although open-ended dietary assessment methods, such as weighed food records (WFRs), are generally considered to be comparable, differences between procedures may influence outcome when WFRs are conducted independently. In this paper, we assess the procedures of WFRs in two studies to describe their dietary assessment procedures and compare the subsequent outcomes. WFRs of 12 days (3 days for four seasons) were conducted as reference methods for intake data, in accordance with the study protocol, among a subsample of participants of two large cohort studies. We compared the WFR procedures descriptively. We also compared some dietary intake variables, such as the frequency of foods and dishes and contributing foods, to determine whether there were differences in the portion size distribution and intra- and inter-individual variation in nutrient intakes caused by the difference in procedures. General procedures of the dietary records were conducted in accordance with the National Health and Nutrition Survey and were the same for both studies. Differences were seen in 1) selection of multiple days (non-consecutive days versus consecutive days); and 2) survey sheet recording method (individual versus family participation). However, the foods contributing to intake of energy and selected nutrients, the portion size distribution, and intra- and inter-individual variation in nutrient intakes were similar between the two studies. Our comparison of WFR procedures in two independent studies revealed several differences. Notwithstanding these procedural differences, however, the subsequent outcomes were similar. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.
Comparative study between chemical and atmospheric pressure plasma jet cleaning on glass substrate

NASA Astrophysics Data System (ADS)

Elfa, Rizan Rizon; Ahmad, Mohd Khairul; Fhong, Soon Chin; Sahdan, Mohd Zainizan; Nayan, Nafarizal

2017-01-01

The atmospheric pressure plasma jet with low frequency and argon as working gas is presented in this paper to demonstrate its application for glass substrate clean and modification. The glass substrate clean by atmospheric pressure plasma jet is an efficient method to replace other substrate clean method. A comparative analysis is done in this paper between substrate cleaned by chemical and plasma treatment methods. Water contact angle reading is taken for a different method of substrate clean and period of treatment. Under the plasma treatment, the sample shows low surface adhesion due to having the surface property of super hydrophilic surface 7.26°. This comparative analysis is necessary in the industrial application for cost production due to sufficient time and method of substrate clean.
Defect inspection and printability study for 14 nm node and beyond photomask

NASA Astrophysics Data System (ADS)

Seki, Kazunori; Yonetani, Masashi; Badger, Karen; Dechene, Dan J.; Akima, Shinji

2016-10-01

Two different mask inspection techniques are developed and compared for 14 nm node and beyond photomasks, High resolution and Litho-based inspection. High resolution inspection is the general inspection method in which a 19x nm wavelength laser is used with the High NA inspection optics. Litho-based inspection is a new inspection technology. This inspection uses the wafer lithography information, and as such, this method has automatic defect classification capability which is based on wafer printability. Both High resolution and Litho-based inspection methods are compared using 14 nm and 7 nm node programmed defect and production design masks. The defect sensitivity and mask inspectability is compared, in addition to comparing the defect classification and throughput. Additionally, the Cost / Infrastructure comparison is analyzed and the impact of each inspection method is discussed.
Cost-Benefit Analysis for the Advanced Near Net Shape Technology (ANNST) Method for Fabricating Stiffened Cylinders

NASA Technical Reports Server (NTRS)

Stoner, Mary Cecilia; Hehir, Austin R.; Ivanco, Marie L.; Domack, Marcia S.

2016-01-01

This cost-benefit analysis assesses the benefits of the Advanced Near Net Shape Technology (ANNST) manufacturing process for fabricating integrally stiffened cylinders. These preliminary, rough order-of-magnitude results report a 46 to 58 percent reduction in production costs and a 7-percent reduction in weight over the conventional metallic manufacturing technique used in this study for comparison. Production cost savings of 35 to 58 percent were reported over the composite manufacturing technique used in this study for comparison; however, the ANNST concept was heavier. In this study, the predicted return on investment of equipment required for the ANNST method was ten cryogenic tank barrels when compared with conventional metallic manufacturing. The ANNST method was compared with the conventional multi-piece metallic construction and composite processes for fabricating integrally stiffened cylinders. A case study compared these three alternatives for manufacturing a cylinder of specified geometry, with particular focus placed on production costs and process complexity, with cost analyses performed by the analogy and parametric methods. Furthermore, a scalability study was conducted for three tank diameters to assess the highest potential payoff of the ANNST process for manufacture of large-diameter cryogenic tanks. The analytical hierarchy process (AHP) was subsequently used with a group of selected subject matter experts to assess the value of the various benefits achieved by the ANNST method for potential stakeholders. The AHP study results revealed that decreased final cylinder mass and quality assurance were the most valued benefits of cylinder manufacturing methods, therefore emphasizing the relevance of the benefits achieved with the ANNST process for future projects.
Evidence-based risk communication: a systematic review.

PubMed

Zipkin, Daniella A; Umscheid, Craig A; Keating, Nancy L; Allen, Elizabeth; Aung, KoKo; Beyth, Rebecca; Kaatz, Scott; Mann, Devin M; Sussman, Jeremy B; Korenstein, Deborah; Schardt, Connie; Nagi, Avishek; Sloane, Richard; Feldstein, David A

2014-08-19

Effective communication of risks and benefits to patients is critical for shared decision making. To review the comparative effectiveness of methods of communicating probabilistic information to patients that maximize their cognitive and behavioral outcomes. PubMed (1966 to March 2014) and CINAHL, EMBASE, and the Cochrane Central Register of Controlled Trials (1966 to December 2011) using several keywords and structured terms. Prospective or cross-sectional studies that recruited patients or healthy volunteers and compared any method of communicating probabilistic information with another method. Two independent reviewers extracted study characteristics and assessed risk of bias. Eighty-four articles, representing 91 unique studies, evaluated various methods of numerical and visual risk display across several risk scenarios and with diverse outcome measures. Studies showed that visual aids (icon arrays and bar graphs) improved patients' understanding and satisfaction. Presentations including absolute risk reductions were better than those including relative risk reductions for maximizing accuracy and seemed less likely than presentations with relative risk reductions to influence decisions to accept therapy. The presentation of numbers needed to treat reduced understanding. Comparative effects of presentations of frequencies (such as 1 in 5) versus event rates (percentages, such as 20%) were inconclusive. Most studies were small and highly variable in terms of setting, context, and methods of administering interventions. Visual aids and absolute risk formats can improve patients' understanding of probabilistic information, whereas numbers needed to treat can lessen their understanding. Due to study heterogeneity, the superiority of any single method for conveying probabilistic information is not established, but there are several good options to help clinicians communicate with patients. None.
Comparative analysis of methods and sources of financing of the transport organizations activity

NASA Astrophysics Data System (ADS)

Gorshkov, Roman

2017-10-01

The article considers the analysis of methods of financing of transport organizations in conditions of limited investment resources. A comparative analysis of these methods is carried out, the classification of investment, methods and sources of financial support for projects being implemented to date are presented. In order to select the optimal sources of financing for the projects, various methods of financial management and financial support for the activities of the transport organization were analyzed, which were considered from the perspective of analysis of advantages and limitations. The result of the study is recommendations on the selection of optimal sources and methods of financing of transport organizations.
A Study of Impact Point Detecting Method Based on Seismic Signal

NASA Astrophysics Data System (ADS)

Huo, Pengju; Zhang, Yu; Xu, Lina; Huang, Yong

The projectile landing position has to be determined for its recovery and range in the targeting test. In this paper, a global search method based on the velocity variance is proposed. In order to verify the applicability of this method, simulation analysis within the scope of four million square meters has been conducted in the same array structure of the commonly used linear positioning method, and MATLAB was used to compare and analyze the two methods. The compared simulation results show that the global search method based on the speed of variance has high positioning accuracy and stability, which can meet the needs of impact point location.
[The Misgav-Ladach method for cesarean section compared to the Pfannenstiel technique].

PubMed

Studziński, Zbigniew

2002-08-01

The aim of the study was to evaluate the outcome of two different methods of cesarean section. To determine whether the Misgav-Ladach caesarean technique can offer benefits when compared with conventional Pfannenstiel caesarean section technique. This study describes operative details and the postoperative course of 110 patients who underwent caesarean section in May 2000 to December 2000 in Department of Gynecology and Obstetrics in Regional Hospital in Slupsk, Poland. One group (50 women) was operated with the Misgav-Ladach method for caesarean section and the other group (60 women) with Pfannenstiel method. Operating time was significantly different between the two methods, with an average of 20.2 minutes with the Misgav-Ladach method and 47.3 minutes with the Pfannenstiel method (p < 0.001). Time of child delivery was with average 1.1 minutes with the Misgav-Ladach method and 3.8 minutes with the Pfannenstiel method (p < 0.001). The amount of blood loss different significantly, with 336 ml and 483 ml respectively (p < 0.001). No significant difference was found in Apgar scores. No difference was found in overall postoperative complications, wound infection, febrile illness, febrile morbidity, wound dehiscence affected by the new technique. Significantly less suture material was used during Misgav-Ladach caesarean section compared to Pfannenstiel technique (p < 0.001). The Misgav-Ladach method of caesarean section has advantages over the Pfannenstiel technique by being significantly quicker to perform, with the reduced amounts of bleeding and suture material. The women were satisfied with the appearance of their scars. In this study no negative effects of the new operation technique were discovered.
Relative Contributions of Three Descriptive Methods: Implications for Behavioral Assessment

ERIC Educational Resources Information Center

Pence, Sacha T.; Roscoe, Eileen M.; Bourret, Jason C.; Ahearn, William H.

2009-01-01

This study compared the outcomes of three descriptive analysis methods--the ABC method, the conditional probability method, and the conditional and background probability method--to each other and to the results obtained from functional analyses. Six individuals who had been diagnosed with developmental delays and exhibited problem behavior…
Evaluation of Techniques for Measuring Microbial Hazards in Bathing Waters: A Comparative Study

PubMed Central

Schang, Christelle; Henry, Rebekah; Kolotelo, Peter A.; Prosser, Toby; Crosbie, Nick; Grant, Trish; Cottam, Darren; O’Brien, Peter; Coutts, Scott; Deletic, Ana; McCarthy, David T.

2016-01-01

Recreational water quality is commonly monitored by means of culture based faecal indicator organism (FIOs) assays. However, these methods are costly and time-consuming; a serious disadvantage when combined with issues such as non-specificity and user bias. New culture and molecular methods have been developed to counter these drawbacks. This study compared industry-standard IDEXX methods (Colilert and Enterolert) with three alternative approaches: 1) TECTA™ system for E. coli and enterococci; 2) US EPA’s 1611 method (qPCR based enterococci enumeration); and 3) Next Generation Sequencing (NGS). Water samples (233) were collected from riverine, estuarine and marine environments over the 2014–2015 summer period and analysed by the four methods. The results demonstrated that E. coli and coliform densities, inferred by the IDEXX system, correlated strongly with the TECTA™ system. The TECTA™ system had further advantages in faster turnaround times (~12 hrs from sample receipt to result compared to 24 hrs); no staff time required for interpretation and less user bias (results are automatically calculated, compared to subjective colorimetric decisions). The US EPA Method 1611 qPCR method also showed significant correlation with the IDEXX enterococci method; but had significant disadvantages such as highly technical analysis and higher operational costs (330% of IDEXX). The NGS method demonstrated statistically significant correlations between IDEXX and the proportions of sequences belonging to FIOs, Enterobacteriaceae, and Enterococcaceae. While costs (3,000% of IDEXX) and analysis time (300% of IDEXX) were found to be significant drawbacks of NGS, rapid technological advances in this field will soon see it widely adopted. PMID:27213772
A comparative study on the graft copolymerization of acrylic acid onto rayon fibre by a ceric ion redox system and a γ-radiation method.

PubMed

Kaur, Inderjeet; Kumar, Raj; Sharma, Neelam

2010-10-13

Functionalization of rayon fibre has been carried out by grafting acrylic acid (AAC) both by a chemical method using a Ce(4+)-HNO(3) redox initiator and by a mutual irradiation (γ-rays) method. The reaction conditions affecting the grafting percentage have been optimized for both methods, and the results are compared. The maximum percentage of grafting (50%) by the chemical method was obtained utilizing 18.24 × 10(-3) moles/L of ceric ammonium nitrate (CAN), 39.68 × 10(-2) moles/L of HNO(3), and 104.08 × 10(-2) moles/L of AAc in 20 mL of water at 45°C for 120 min. For the radiation method, the maximum grafting percentage (60%) was higher, and the product was obtained under milder reaction conditions using a lower concentration of AAc (69.38 × 10(-2) moles/L) in 10 mL of water at an optimum total dose of 0.932 kGy. Swelling studies showed higher swelling for the grafted rayon fibre in water (854.54%) as compared to the pristine fibre (407%), while dye uptake studies revealed poor uptake of the dye (crystal violet) by the grafted fibre in comparison with the pristine fibre. The graft copolymers were characterized by IR, TGA, and scanning electron micrographic methods. Grafted fibre, prepared by the radiation-induced method, showed better thermal behaviour. Comparison of the two methods revealed that the radiation method of grafting of acrylic acid onto rayon fibre is a better method of grafting in comparison with the chemical method. Copyright © 2010 Elsevier Ltd. All rights reserved.
The Ultimate Pile Bearing Capacity from Conventional and Spectral Analysis of Surface Wave (SASW) Measurements

NASA Astrophysics Data System (ADS)

Faizah Bawadi, Nor; Anuar, Shamilah; Rahim, Mustaqqim A.; Mansor, A. Faizal

2018-03-01

A conventional and seismic method for determining the ultimate pile bearing capacity was proposed and compared. The Spectral Analysis of Surface Wave (SASW) method is one of the non-destructive seismic techniques that do not require drilling and sampling of soils, was used in the determination of shear wave velocity (Vs) and damping (D) profile of soil. The soil strength was found to be directly proportional to the Vs and its value has been successfully applied to obtain shallow bearing capacity empirically. A method is proposed in this study to determine the pile bearing capacity using Vs and D measurements for the design of pile and also as an alternative method to verify the bearing capacity from the other conventional methods of evaluation. The objectives of this study are to determine Vs and D profile through frequency response data from SASW measurements and to compare pile bearing capacities obtained from the method carried out and conventional methods. All SASW test arrays were conducted near the borehole and location of conventional pile load tests. In obtaining skin and end bearing pile resistance, the Hardin and Drnevich equation has been used with reference strains obtained from the method proposed by Abbiss. Back analysis results of pile bearing capacities from SASW were found to be 18981 kN and 4947 kN compared to 18014 kN and 4633 kN of IPLT with differences of 5% and 6% for Damansara and Kuala Lumpur test sites, respectively. The results of this study indicate that the seismic method proposed in this study has the potential to be used in estimating the pile bearing capacity.
A comparative analysis of ethnomedicinal practices for treating gastrointestinal disorders used by communities living in three national parks (Korea).

PubMed

Kim, Hyun; Song, Mi-Jang; Brian, Heldenbrand; Choi, Kyoungho

2014-01-01

The purpose of this study is to comparatively analyze the ethnomedicinal practices on gastrointestinal disorders within communities in Jirisan National Park, Gayasan National Park, and Hallasan National Park of Korea. Data was collected through participant observations and indepth interviews with semistructured questionnaires. Methods for comparative analysis were accomplished using the informant consensus factor, fidelity level, and internetwork analysis. A total of 490 ethnomedicinal practices recorded from the communities were classified into 110 families, 176 genera, and 220 species that included plants, animals, fungi, and alga. The informant consensus factor values in the disorder categories were enteritis, and gastralgia (1.0), followed by indigestion (0.94), constipation (0.93), and abdominal pain and gastroenteric trouble (0.92). In terms of fidelity levels, 71 plant species showed fidelity levels of 100%. The internetwork analysis between disorders and all medicinal species are grouped in the center by the four categories of indigestion, diarrhea, abdominal pain, and gastroenteric trouble, respectively. Regarding the research method of this study, the comparative analysis methods will contribute to the availability of orally transmitted ethnomedicinal knowledge. Among the methods of analysis, the use of internetwork analysis as a tool for analysis in this study provides imperative internetwork maps between gastrointestinal disorders and medicinal species.
Proposing a sequential comparative analysis for assessing multilateral health agency transformation and sustainable capacity: exploring the advantages of institutional theory

PubMed Central

2014-01-01

Background This article proposes an approach to comparing and assessing the adaptive capacity of multilateral health agencies in meeting country and individual healthcare needs. Most studies comparing multilateral health agencies have failed to clearly propose a method for conducting agency comparisons. Methods This study conducted a qualitative case study methodological approach, such that secondary and primary case study literature was used to conduct case study comparisons of multilateral health agencies. Results Through the proposed Sequential Comparative Analysis (SCA), the author found a more effective way to justify the selection of cases, compare and assess organizational transformative capacity, and to learn from agency success in policy sustainability processes. Conclusions To more affectively understand and explain why some multilateral health agencies are more capable of adapting to country and individual healthcare needs, SCA provides a methodological approach that may help to better understand why these agencies are so different and what we can learn from successful reform processes. As funding challenges continue to hamper these agencies' adaptive capacity, learning from each other will become increasingly important. PMID:24886283
Comparison of parameter-adapted segmentation methods for fluorescence micrographs.

PubMed

Held, Christian; Palmisano, Ralf; Häberle, Lothar; Hensel, Michael; Wittenberg, Thomas

2011-11-01

Interpreting images from fluorescence microscopy is often a time-consuming task with poor reproducibility. Various image processing routines that can help investigators evaluate the images are therefore useful. The critical aspect for a reliable automatic image analysis system is a robust segmentation algorithm that can perform accurate segmentation for different cell types. In this study, several image segmentation methods were therefore compared and evaluated in order to identify the most appropriate segmentation schemes that are usable with little new parameterization and robustly with different types of fluorescence-stained cells for various biological and biomedical tasks. The study investigated, compared, and enhanced four different methods for segmentation of cultured epithelial cells. The maximum-intensity linking (MIL) method, an improved MIL, a watershed method, and an improved watershed method based on morphological reconstruction were used. Three manually annotated datasets consisting of 261, 817, and 1,333 HeLa or L929 cells were used to compare the different algorithms. The comparisons and evaluations showed that the segmentation performance of methods based on the watershed transform was significantly superior to the performance of the MIL method. The results also indicate that using morphological opening by reconstruction can improve the segmentation of cells stained with a marker that exhibits the dotted surface of cells. Copyright © 2011 International Society for Advancement of Cytometry.
Upscaling permeability for three-dimensional fractured porous rocks with the multiple boundary method

NASA Astrophysics Data System (ADS)

Chen, Tao; Clauser, Christoph; Marquart, Gabriele; Willbrand, Karen; Hiller, Thomas

2018-02-01

Upscaling permeability of grid blocks is crucial for groundwater models. A novel upscaling method for three-dimensional fractured porous rocks is presented. The objective of the study was to compare this method with the commonly used Oda upscaling method and the volume averaging method. First, the multiple boundary method and its computational framework were defined for three-dimensional stochastic fracture networks. Then, the different upscaling methods were compared for a set of rotated fractures, for tortuous fractures, and for two discrete fracture networks. The results computed by the multiple boundary method are comparable with those of the other two methods and fit best the analytical solution for a set of rotated fractures. The errors in flow rate of the equivalent fracture model decrease when using the multiple boundary method. Furthermore, the errors of the equivalent fracture models increase from well-connected fracture networks to poorly connected ones. Finally, the diagonal components of the equivalent permeability tensors tend to follow a normal or log-normal distribution for the well-connected fracture network model with infinite fracture size. By contrast, they exhibit a power-law distribution for the poorly connected fracture network with multiple scale fractures. The study demonstrates the accuracy and the flexibility of the multiple boundary upscaling concept. This makes it attractive for being incorporated into any existing flow-based upscaling procedures, which helps in reducing the uncertainty of groundwater models.
Comparison of multiple methods to measure maternal fat mass in late gestation12

PubMed Central

Marshall, Nicole E; Murphy, Elizabeth J; King, Janet C; Haas, E Kate; Lim, Jeong Y; Wiedrick, Jack; Thornburg, Kent L; Purnell, Jonathan Q

2016-01-01

Background: Measurements of maternal fat mass (FM) are important for studies of maternal and fetal health. Common methods of estimating FM have not been previously compared in pregnancy with measurements using more complete body composition models. Objectives: The goal of this pilot study was to compare multiple methods that estimate FM, including 2-, 3- and 4-compartment models in pregnant women at term, and to determine how these measures compare with FM by dual-energy X-ray absorptiometry (DXA) 2 wk postpartum. Design: Forty-one healthy pregnant women with prepregnancy body mass index (in kg/m2) 19 to 46 underwent skinfold thickness (SFT), bioelectrical impedance analysis (BIA), body density (Db) via air displacement plethysmography (ADP), and deuterium dilution of total body water (TBW) with and without adjustments for gestational age using van Raaij (VRJ) equations at 37–38 wk of gestation and 2 wk postpartum to derive 8 estimates of maternal FM. Deming regression analysis and Bland-Altman plots were used to compare methods of FM assessment. Results: Systematic differences in FM estimates were found. Methods for FM estimates from lowest to highest were 4-compartment, DXA, TBW(VRJ), 3-compartment, Db(VRJ), BIA, air displacement plethysmography body density, and SFT ranging from a mean ± SD of 29.5 ± 13.2 kg via 4-compartment to 39.1 ± 11.7 kg via SFT. Compared with postpartum DXA values, Deming regressions revealed no substantial departures from trend lines in maternal FM in late pregnancy for any of the methods. The 4-compartment method showed substantial negative (underestimating) constant bias, and the air displacement plethysmography body density and SFT methods showed positive (overestimating) constant bias. ADP via Db(VRJ) and 3-compartment methods had the highest precision; BIA had the lowest. Conclusions: ADP that uses gestational age-specific equations may provide a reasonable and practical measurement of maternal FM across a spectrum of body weights in late pregnancy. SFT would be acceptable for use in larger studies. This trial was registered at clinicaltrials.gov as NCT02586714. PMID:26888714

Sample size and power estimation for studies with health related quality of life outcomes: a comparison of four methods using the SF-36.

PubMed

Walters, Stephen J

2004-05-25

We describe and compare four different methods for estimating sample size and power, when the primary outcome of the study is a Health Related Quality of Life (HRQoL) measure. These methods are: 1. assuming a Normal distribution and comparing two means; 2. using a non-parametric method; 3. Whitehead's method based on the proportional odds model; 4. the bootstrap. We illustrate the various methods, using data from the SF-36. For simplicity this paper deals with studies designed to compare the effectiveness (or superiority) of a new treatment compared to a standard treatment at a single point in time. The results show that if the HRQoL outcome has a limited number of discrete values (< 7) and/or the expected proportion of cases at the boundaries is high (scoring 0 or 100), then we would recommend using Whitehead's method (Method 3). Alternatively, if the HRQoL outcome has a large number of distinct values and the proportion at the boundaries is low, then we would recommend using Method 1. If a pilot or historical dataset is readily available (to estimate the shape of the distribution) then bootstrap simulation (Method 4) based on this data will provide a more accurate and reliable sample size estimate than conventional methods (Methods 1, 2, or 3). In the absence of a reliable pilot set, bootstrapping is not appropriate and conventional methods of sample size estimation or simulation will need to be used. Fortunately, with the increasing use of HRQoL outcomes in research, historical datasets are becoming more readily available. Strictly speaking, our results and conclusions only apply to the SF-36 outcome measure. Further empirical work is required to see whether these results hold true for other HRQoL outcomes. However, the SF-36 has many features in common with other HRQoL outcomes: multi-dimensional, ordinal or discrete response categories with upper and lower bounds, and skewed distributions, so therefore, we believe these results and conclusions using the SF-36 will be appropriate for other HRQoL measures.
Excitons in Potassium Bromide: A Study using Embedded Time-dependent Density Functional Theory and Equation-of-Motion Coupled Cluster Methods

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

Govind, Niranjan; Sushko, Petr V.; Hess, Wayne P.

2009-03-05

We present a study of the electronic excitations in insulating materials using an embedded- cluster method. The excited states of the embedded cluster are studied systematically using time-dependent density functional theory (TDDFT) and high-level equation-of-motion coupled cluster (EOMCC) methods. In particular, we have used EOMCC models with singles and doubles (EOMCCSD) and two approaches which account for the e®ect of triply excited con¯gurations in non-iterative and iterative fashions. We present calculations of the lowest surface excitations of the well-studied potassium bromide (KBr) system and compare our results with experiment. The bulk-surface exciton shift is also calculated at the TDDFT levelmore » and compared with experiment.« less
Sample size for post-marketing safety studies based on historical controls.

PubMed

Wu, Yu-te; Makuch, Robert W

2010-08-01

As part of a drug's entire life cycle, post-marketing studies are an important part in the identification of rare, serious adverse events. Recently, the US Food and Drug Administration (FDA) has begun to implement new post-marketing safety mandates as a consequence of increased emphasis on safety. The purpose of this research is to provide exact sample size formula for the proposed hybrid design, based on a two-group cohort study with incorporation of historical external data. Exact sample size formula based on the Poisson distribution is developed, because the detection of rare events is our outcome of interest. Performance of exact method is compared to its approximate large-sample theory counterpart. The proposed hybrid design requires a smaller sample size compared to the standard, two-group prospective study design. In addition, the exact method reduces the number of subjects required in the treatment group by up to 30% compared to the approximate method for the study scenarios examined. The proposed hybrid design satisfies the advantages and rationale of the two-group design with smaller sample sizes generally required. 2010 John Wiley & Sons, Ltd.
Comparative study of fourteen alkaloids from Uncaria rhynchophylla hooks and leaves using HPLC-diode array detection-atmospheric pressure chemical ionization/MS method.

PubMed

Qu, Jialin; Gong, Tianxing; Ma, Bin; Zhang, Lin; Kano, Yoshihiro; Yuan, Dan

2012-01-01

The purpose of the study is to compare alkaloid profile of Uncaria rhynchophylla hooks and leaves. Ten oxindole alkaloids and four glycosidic indole alkaloids were identified using HPLC-diode array detection (DAD) or LC-atmospheric pressure chemical ionization (APCI)-MS method, and a HPLC-UV method for simultaneous quantification of major alkaloids was validated. The hooks are characterized by high levels of four oxindole alkaloids rhynchophylline (R), isorhynchophylline (IR), corynoxeine (C) and isocorynoxeine (IC), while the leaves contained high level of two glycosidic indole alkaloids vincoside lactam (VL) and strictosidine (S). The presented methods have proven its usefulness in chemical characterization of U. rhynchophylla hooks and leaves.
Comparative study on the measurement of learning outcomes after powerpoint presentation and problem based learning with discussion in family medicine amongst fifth year medical students.

PubMed

Khobragade, Sujata; Abas, Adinegara Lutfi; Khobragade, Yadneshwar Sudam

2016-01-01

Learning outcomes after traditional teaching methods were compared with problem-based learning (PBL) among fifth year medical students. Six students participated each in traditional teaching and PBL methods, respectively. Traditional teaching method involved PowerPoint (PPT) presentation and PBL included study on case scenario and discussion. Both methods were effective in improving performance of students. Postteaching, we did not find significant differences in learning outcomes between these two teaching methods. (1) Study was conducted with an intention to find out which method of learning is more effective; traditional or PBL. (2) To assess the level of knowledge and understanding in anemia/zoonotic diseases as against diabetes/hypertension. All the students posted from February 3, 2014, to March 14, 2014, participated in this study. Six students were asked to prepare and present a lecture (PPT) and subsequent week other six students were asked to present PBL. Both groups presented different topics. Since it was a pre- and post-test, same students were taken as control. To maintain uniformity and to avoid bias due cultural diversity, language etc., same questions were administered. After taking verbal consent, all 34 students were given pretest on anemia and zoonotic diseases. Then lecture (PPT) by six students on the same topic was given it followed by posttest questionnaire. Subsequent week pretest was conducted on hypertension and diabetes. Then case scenario presentation and discussion (PBL) was done by different six students followed by posttest. Both the methods were compared. Analysis was done manually and standard error of means and students t -test was used to find out statistical significance. We found statistically significant improvement in performance of students after PPT presentation as well as PBL. Both methods are equally effective. However, Pretest results of students in anemia and zoonotic diseases (Group A) were poor compared to pretest results of students in hypertension and diabetes (Group B). The students who participated in presentation did not influence their performance as they were covering a small part of the topic and there were no differences in their marks compared to other students. We did not find significant differences in outcome after teaching between PBL and traditional methods. Performances of students were poor in anemia and zoonotic diseases which need remedial teaching. Assessment may influence retention ability and performance.
Should We Trust Web-Based Studies? A Comparative Analysis of Six Preconceptions about Internet Questionnaires

ERIC Educational Resources Information Center

Gosling, Samuel D.; Vazire, Simine; Srivastava, Sanjay; Oliver, John

2004-01-01

The rapid growth of the Internet provides a wealth of new research opportunities for psychologists. Internet data collection methods, with a focus on self-report questionnaires from self-selected samples, are evaluated and compared with traditional paper-and-pencil methods. Six preconceptions about Internet samples and data quality are evaluated…
Simultaneous and Comparable Numerical Indicators of International, National and Local Collaboration Practices in English-Medium Astrophysics Research Papers

ERIC Educational Resources Information Center

Méndez, David I.; Alcaraz, M. Ángeles

2016-01-01

Introduction: We report an investigation on collaboration practices in research papers published in the most prestigious English-medium astrophysics journals. Method: We propose an evaluation method based on three numerical indicators to study and compare, in absolute terms, three different types of collaboration (international, national and…
Does Comparing Solution Methods Facilitate Conceptual and Procedural Knowledge? An Experimental Study on Learning to Solve Equations

ERIC Educational Resources Information Center

Rittle-Johnson, Bethany; Star, Jon R.

2007-01-01

Encouraging students to share and compare solution methods is a key component of reform efforts in mathematics, and comparison is emerging as a fundamental learning mechanism. To experimentally evaluate the effects of comparison for mathematics learning, the authors randomly assigned 70 seventh-grade students to learn about algebra equation…
Is Health-Related Quality of Life after Radical Cystectomy Using Validated Questionnaires Really Better in Patients with Ileal Orthotopic Neobladder Compared to Ileal Conduit: A Meta-Analysis of Retrospective Comparative Studies

PubMed Central

Cerruto, Maria A.; D'Elia, Carolina; Siracusano, Salvatore; Porcaro, Antonio B.; Cacciamani, Giovanni; De Marchi, Davide; Niero, Mauro; Lonardi, Cristina; Iafrate, Massimo; Bassi, Pierfrancesco; Belgrano, Emanuele; Imbimbo, Ciro; Racioppi, Marco; Talamini, Renato; Ciciliato, Stefano; Toffoli, Laura; Rizzo, Michele; Visalli, Francesco; Verze, Paolo; Artibani, Walter

2017-01-01

Introduction From the most recent systematic revision of the literature, an orthotopic neobladder would seem to show marginally better health related quality of life (HR-QoL) scores compared with an ileal conduit. The aim of this study was to review all relevant published studies about the comparison between ileal orthotopic neobladder (IONB) and ileal conduit using validated HR-QoL questionnaires. Materials and Methods Studies were identified by searching multiple literature databases. Data were synthesized using meta-analytic methods conformed to the PRISMA statement. Results The literature search identified 10 papers; pooled effect sizes of combined quality of life outcomes for ileal conduit versus IONB showed a significantly better HR-QoL in patients with IONB (Hedges' g = 0.278; p = 0.000);. The present study has an important limitation due to the type of the analyzed comparative studies, all retrospective and not randomized. Conclusion This meta-analysis of not-randomized, retrospective comparative studies on the impact of ileal conduit versus IONB on HR-QoL showed a significant advantage of IONB subgroups. PMID:28785189
Use of Vein Conduit and Isolated Nerve Graft in Peripheral Nerve Repair: A Comparative Study

PubMed Central

Ahmad, Imran; Akhtar, Md. Sohaib

2014-01-01

Aims and Objectives. The aim of this study was to evaluate the effectiveness of vein conduit in nerve repair compared with isolated nerve graft. Materials and Methods. This retrospective study was conducted at author's centre and included a total of 40 patients. All the patients had nerve defect of more than 3 cm and underwent nerve repair using nerve graft from sural nerve. In 20 cases, vein conduit (study group) was used whereas no conduit was used in other 20 cases. Patients were followed up for 2 years at the intervals of 3 months. Results. Patients had varying degree of recovery. Sensations reached to all the digits at 1 year in study groups compared to 18 months in control group. At the end of second year, 84% patients of the study group achieved 2-point discrimination of <10 mm compared to 60% only in control group. In terms of motor recovery, 82% patients achieved satisfactory hand function in study group compared to 56% in control group (P < .05). Conclusions. It was concluded that the use of vein conduit in peripheral nerve repair is more effective method than isolated nerve graft providing good sensory and motor recovery. PMID:25405029
Effect of joint spacing and joint dip on the stress distribution around tunnels using different numerical methods

NASA Astrophysics Data System (ADS)

Nikadat, Nooraddin; Fatehi Marji, Mohammad; Rahmannejad, Reza; Yarahmadi Bafghi, Alireza

2016-11-01

Different conditions may affect the stability of tunnels by the geometry (spacing and orientation) of joints in the surrounded rock mass. In this study, by comparing the results obtained by the three novel numerical methods i.e. finite element method (Phase2), discrete element method (UDEC) and indirect boundary element method (TFSDDM), the effects of joint spacing and joint dips on the stress distribution around rock tunnels are numerically studied. These comparisons indicate the validity of the stress analyses around circular rock tunnels. These analyses also reveal that for a semi-continuous environment, boundary element method gives more accurate results compared to the results of finite element and distinct element methods. In the indirect boundary element method, the displacements due to joints of different spacing and dips are estimated by using displacement discontinuity (DD) formulations and the total stress distribution around the tunnel are obtained by using fictitious stress (FS) formulations.
Analytical evaluation of current starch methods used in the international sugar industry: Part I.

PubMed

Cole, Marsha; Eggleston, Gillian; Triplett, Alexa

2017-08-01

Several analytical starch methods exist in the international sugar industry to mitigate starch-related processing challenges and assess the quality of traded end-products. These methods use iodometric chemistry, mostly potato starch standards, and utilize similar solubilization strategies, but had not been comprehensively compared. In this study, industrial starch methods were compared to the USDA Starch Research method using simulated raw sugars. Type of starch standard, solubilization approach, iodometric reagents, and wavelength detection affected total starch determination in simulated raw sugars. Simulated sugars containing potato starch were more accurately detected by the industrial methods, whereas those containing corn starch, a better model for sugarcane starch, were only accurately measured by the USDA Starch Research method. Use of a potato starch standard curve over-estimated starch concentrations. Among the variables studied, starch standard, solubilization approach, and wavelength detection affected the sensitivity, accuracy/precision, and limited the detection/quantification of the current industry starch methods the most. Published by Elsevier Ltd.
Disinfection of transvaginal ultrasound probes in a clinical setting: comparative performance of automated and manual reprocessing methods.

PubMed

Buescher, D L; Möllers, M; Falkenberg, M K; Amler, S; Kipp, F; Burdach, J; Klockenbusch, W; Schmitz, R

2016-05-01

Transvaginal and intracavitary ultrasound probes are a possible source of cross-contamination with microorganisms and thus a risk to patients' health. Therefore appropriate methods for reprocessing are needed. This study was designed to compare the standard disinfection method for transvaginal ultrasound probes in Germany with an automated disinfection method in a clinical setting. This was a prospective randomized controlled clinical study of two groups. In each group, 120 microbial samples were collected from ultrasound transducers before and after disinfection with either an automated method (Trophon EPR®) or a manual method (Mikrozid Sensitive® wipes). Samples were then analyzed for microbial growth and isolates were identified to species level. Automated disinfection had a statistically significantly higher success rate of 91.4% (106/116) compared with 78.8% (89/113) for manual disinfection (P = 0.009). The risk of contamination was increased by 2.9-fold when disinfection was performed manually (odds ratio, 2.9 (95% CI, 1.3-6.3)). Before disinfection, bacterial contamination was observed on 98.8% of probes. Microbial analysis revealed 36 different species of bacteria, including skin and environmental bacteria as well as pathogenic bacteria such as Staphylococcus aureus, enterobacteriaceae and Pseudomonas spp. Considering the high number of contaminated probes and bacterial species found, disinfection of the ultrasound probe's body and handle should be performed after each use to decrease the risk of cross-contamination. This study favored automated disinfection owing to its significantly higher efficacy compared with a manual method. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
Kaplan-Meier Survival Analysis Overestimates the Risk of Revision Arthroplasty: A Meta-analysis.

PubMed

Lacny, Sarah; Wilson, Todd; Clement, Fiona; Roberts, Derek J; Faris, Peter D; Ghali, William A; Marshall, Deborah A

2015-11-01

Although Kaplan-Meier survival analysis is commonly used to estimate the cumulative incidence of revision after joint arthroplasty, it theoretically overestimates the risk of revision in the presence of competing risks (such as death). Because the magnitude of overestimation is not well documented, the potential associated impact on clinical and policy decision-making remains unknown. We performed a meta-analysis to answer the following questions: (1) To what extent does the Kaplan-Meier method overestimate the cumulative incidence of revision after joint replacement compared with alternative competing-risks methods? (2) Is the extent of overestimation influenced by followup time or rate of competing risks? We searched Ovid MEDLINE, EMBASE, BIOSIS Previews, and Web of Science (1946, 1980, 1980, and 1899, respectively, to October 26, 2013) and included article bibliographies for studies comparing estimated cumulative incidence of revision after hip or knee arthroplasty obtained using both Kaplan-Meier and competing-risks methods. We excluded conference abstracts, unpublished studies, or studies using simulated data sets. Two reviewers independently extracted data and evaluated the quality of reporting of the included studies. Among 1160 abstracts identified, six studies were included in our meta-analysis. The principal reason for the steep attrition (1160 to six) was that the initial search was for studies in any clinical area that compared the cumulative incidence estimated using the Kaplan-Meier versus competing-risks methods for any event (not just the cumulative incidence of hip or knee revision); we did this to minimize the likelihood of missing any relevant studies. We calculated risk ratios (RRs) comparing the cumulative incidence estimated using the Kaplan-Meier method with the competing-risks method for each study and used DerSimonian and Laird random effects models to pool these RRs. Heterogeneity was explored using stratified meta-analyses and metaregression. The pooled cumulative incidence of revision after hip or knee arthroplasty obtained using the Kaplan-Meier method was 1.55 times higher (95% confidence interval, 1.43-1.68; p < 0.001) than that obtained using the competing-risks method. Longer followup times and higher proportions of competing risks were not associated with increases in the amount of overestimation of revision risk by the Kaplan-Meier method (all p > 0.10). This may be due to the small number of studies that met the inclusion criteria and conservative variance approximation. The Kaplan-Meier method overestimates risk of revision after hip or knee arthroplasty in populations where competing risks (such as death) might preclude the occurrence of the event of interest (revision). Competing-risks methods should be used to more accurately estimate the cumulative incidence of revision when the goal is to plan healthcare services and resource allocation for revisions.
Reviewing subchondral cartilage surgery: considerations for standardised and outcome predictable cartilage remodelling: a technical note.

PubMed

Benthien, Jan P; Behrens, Peter

2013-11-01

The potential of subchondral mesenchymal stem cell stimulation (MSS) for cartilage repair has led to the widespread use of microfracture as a first line treatment for full thickness articular cartilage defects. Recent focus on the effects of subchondral bone during cartilage injury and repair has expanded the understanding of the strengths and limitations in MSS and opened new pathways for potential improvement. Comparative studies have shown that bone marrow access has positive implications for pluripotential cell recruitment, repair quality and quantity, i.e. deeper channels elicited better cartilage fill, more hyaline cartilage character with higher type II collagen content and lower type I collagen content compared to shallow marrow access. A subchondral needling procedure using standardised and thin subchondral perforations deep into the subarticular bone marrow making the MSS more consistent with the latest developments in subchondral cartilage remodelling is proposed. As this is a novel method clinical studies have been initiated to evaluate the procedure especially compared to microfracturing. However, the first case studies and follow-ups indicate that specific drills facilitate reaching the subchondral bone marrow while the needle size makes perforation of the subchondral bone easier and more predictable. Clinical results of the first group of patients seem to compare well to microfracturing. The authors suggest a new method for a standardised procedure using a new perforating device. Advances in MSS by subchondral bone marrow perforation are discussed. It remains to be determined by clinical studies how this method compares to microfracturing. The subchondral needling offers the surgeon and the investigator a method that facilitates comparison studies because of its defined depth of subchondral penetration and needle size.
Agreement between gastrointestinal panel testing and standard microbiology methods for detecting pathogens in suspected infectious gastroenteritis: Test evaluation and meta-analysis in the absence of a reference standard.

PubMed

Freeman, Karoline; Tsertsvadze, Alexander; Taylor-Phillips, Sian; McCarthy, Noel; Mistry, Hema; Manuel, Rohini; Mason, James

2017-01-01

Multiplex gastrointestinal pathogen panel (GPP) tests simultaneously identify bacterial, viral and parasitic pathogens from the stool samples of patients with suspected infectious gastroenteritis presenting in hospital or the community. We undertook a systematic review to compare the accuracy of GPP tests with standard microbiology techniques. Searches in Medline, Embase, Web of Science and the Cochrane library were undertaken from inception to January 2016. Eligible studies compared GPP tests with standard microbiology techniques in patients with suspected gastroenteritis. Quality assessment of included studies used tailored QUADAS-2. In the absence of a reference standard we analysed test performance taking GPP tests and standard microbiology techniques in turn as the benchmark test, using random effects meta-analysis of proportions. No study provided an adequate reference standard with which to compare the test accuracy of GPP and conventional tests. Ten studies informed a meta-analysis of positive and negative agreement. Positive agreement across all pathogens was 0.93 (95% CI 0.90 to 0.96) when conventional methods were the benchmark and 0.68 (95% CI: 0.58 to 0.77) when GPP provided the benchmark. Negative agreement was high in both instances due to the high proportion of negative cases. GPP testing produced a greater number of pathogen-positive findings than conventional testing. It is unclear whether these additional 'positives' are clinically important. GPP testing has the potential to simplify testing and accelerate reporting when compared to conventional microbiology methods. However the impact of GPP testing upon the management, treatment and outcome of patients is poorly understood and further studies are needed to evaluate the health economic impact of GPP testing compared with standard methods. The review protocol is registered with PROSPERO as CRD42016033320.
Analysis of small sample size studies using nonparametric bootstrap test with pooled resampling method.

PubMed

Dwivedi, Alok Kumar; Mallawaarachchi, Indika; Alvarado, Luis A

2017-06-30

Experimental studies in biomedical research frequently pose analytical problems related to small sample size. In such studies, there are conflicting findings regarding the choice of parametric and nonparametric analysis, especially with non-normal data. In such instances, some methodologists questioned the validity of parametric tests and suggested nonparametric tests. In contrast, other methodologists found nonparametric tests to be too conservative and less powerful and thus preferred using parametric tests. Some researchers have recommended using a bootstrap test; however, this method also has small sample size limitation. We used a pooled method in nonparametric bootstrap test that may overcome the problem related with small samples in hypothesis testing. The present study compared nonparametric bootstrap test with pooled resampling method corresponding to parametric, nonparametric, and permutation tests through extensive simulations under various conditions and using real data examples. The nonparametric pooled bootstrap t-test provided equal or greater power for comparing two means as compared with unpaired t-test, Welch t-test, Wilcoxon rank sum test, and permutation test while maintaining type I error probability for any conditions except for Cauchy and extreme variable lognormal distributions. In such cases, we suggest using an exact Wilcoxon rank sum test. Nonparametric bootstrap paired t-test also provided better performance than other alternatives. Nonparametric bootstrap test provided benefit over exact Kruskal-Wallis test. We suggest using nonparametric bootstrap test with pooled resampling method for comparing paired or unpaired means and for validating the one way analysis of variance test results for non-normal data in small sample size studies. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.
A comparative study of ChIP-seq sequencing library preparation methods.

PubMed

Sundaram, Arvind Y M; Hughes, Timothy; Biondi, Shea; Bolduc, Nathalie; Bowman, Sarah K; Camilli, Andrew; Chew, Yap C; Couture, Catherine; Farmer, Andrew; Jerome, John P; Lazinski, David W; McUsic, Andrew; Peng, Xu; Shazand, Kamran; Xu, Feng; Lyle, Robert; Gilfillan, Gregor D

2016-10-21

ChIP-seq is the primary technique used to investigate genome-wide protein-DNA interactions. As part of this procedure, immunoprecipitated DNA must undergo "library preparation" to enable subsequent high-throughput sequencing. To facilitate the analysis of biopsy samples and rare cell populations, there has been a recent proliferation of methods allowing sequencing library preparation from low-input DNA amounts. However, little information exists on the relative merits, performance, comparability and biases inherent to these procedures. Notably, recently developed single-cell ChIP procedures employing microfluidics must also employ library preparation reagents to allow downstream sequencing. In this study, seven methods designed for low-input DNA/ChIP-seq sample preparation (Accel-NGS® 2S, Bowman-method, HTML-PCR, SeqPlex™, DNA SMART™, TELP and ThruPLEX®) were performed on five replicates of 1 ng and 0.1 ng input H3K4me3 ChIP material, and compared to a "gold standard" reference PCR-free dataset. The performance of each method was examined for the prevalence of unmappable reads, amplification-derived duplicate reads, reproducibility, and for the sensitivity and specificity of peak calling. We identified consistent high performance in a subset of the tested reagents, which should aid researchers in choosing the most appropriate reagents for their studies. Furthermore, we expect this work to drive future advances by identifying and encouraging use of the most promising methods and reagents. The results may also aid judgements on how comparable are existing datasets that have been prepared with different sample library preparation reagents.
Desensitization And Study-Skills Training As Treatment For Two Types of Test-Anxious Students

ERIC Educational Resources Information Center

Osterhouse, Robert A.

1972-01-01

This study compared the effectiveness of systematic desensitization and training in efficient study methods for reducing test anxiety among subjects selected on the basis of two types of self reported anxiety. Desensitization offered more promise as a treatment method for test anxiety than did training in study skills. (Author)
Testing two methods to create comparable scale scores between the Job Content Questionnaire (JCQ) and JCQ-like questionnaires in the European JACE Study.

PubMed

Karasek, Robert; Choi, BongKyoo; Ostergren, Per-Olof; Ferrario, Marco; De Smet, Patrick

2007-01-01

Scale comparative properties of "JCQ-like" questionnaires with respect to the JCQ have been little known. Assessing validity and reliability of two methods for generating comparable scale scores between the Job Content Questionnaire (JCQ) and JCQ-like questionnaires in sub-populations of the large Job Stress, Absenteeism and Coronary Heart Disease European Cooperative (JACE) study: the Swedish version of Demand-Control Questionnaire (DCQ) and a transformed Multinational Monitoring of Trends and Determinants in Cardiovascular Disease Project (MONICA) questionnaire. A random population sample of all Malmo males and females aged 52-58 (n = 682) years was given a new test questionnaire with both instruments (the JCQ and the DCQ). Comparability-facilitating algorithms were created (Method I). For the transformed Milan MONICA questionnaire, a simple weighting system was used (Method II). The converted scale scores from the JCQ-like questionnaires were found to be reliable and highly correlated to those of the original JCQ. However, agreements for the high job strain group between the JCQ and the DCQ, and between the JCQ and the DCQ (Method I applied) were only moderate (Kappa). Use of a multiple level job strain scale generated higher levels of job strain agreement, as did a new job strain definition that excludes the intermediate levels of the job strain distribution. The two methods were valid and generally reliable.

Mobile Learning vs. Traditional Classroom Lessons: A Comparative Study

ERIC Educational Resources Information Center

Furió, D.; Juan, M.-C.; Seguí, I.; Vivó, R.

2015-01-01

Different methods can be used for learning, and they can be compared in several aspects, especially those related to learning outcomes. In this paper, we present a study in order to compare the learning effectiveness and satisfaction of children using an iPhone game for learning the water cycle vs. the traditional classroom lesson. The iPhone game…
Continuous nasogastric milk feeding versus intermittent bolus milk feeding for premature infants less than 1500 grams.

PubMed

Premji, Shahirose S; Chessell, Lorraine

2011-11-09

Milk feedings can be given via nasogastric tube either intermittently, typically over 10 to 20 minutes every two or three hours, or continuously, using an infusion pump. Although theoretical benefits and risks of each method have been proposed, effects on clinically important outcomes remain uncertain. To examine the evidence regarding the effectiveness of continuous versus intermittent bolus nasogastric milk feeding in premature infants less than 1500 grams. Searches were performed of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2011), MEDLINE, CINAHL and HealthSTAR up to July 2011. Randomised and quasi-randomised clinical trials comparing continuous versus intermittent bolus nasogastric milk feeding in premature infants less than 1500 grams. Two review authors independently assessed all trials for relevance and methodologic quality. The standard methods of the Cochrane Neonatal Review Group were used to extract data. Overall, the seven included trials, involving 511 infants, found no differences in time to achieve full enteral feeds between feeding methods (weighted mean difference (WMD) 2 days; 95% CI -0.3 to 3.9) . In the subgroup analysis of those studies comparing continuous nasogastric versus intermittent bolus nasogastric milk feedings the findings remained unchanged (WMD 2 days, 95% CI -0.4 to 4.1). There was no significant difference in somatic growth and incidence of NEC between feeding methods irrespective of tube placement. One study noted a trend toward more apneas during the study period in infants fed by the continuous tube feeding method compared to those fed by intermittent feedings delivered predominantly by orogastric tube placements [mean difference (MD) 14.0 apneas during study period; 95% CI -0.2 to 28.2]. In subgroup analysis based on weight groups, one study suggested that infants less than 1000 grams and 1000 to 1250 grams birth weight gained weight faster when fed by the continuous nasogastric tube feeding method compared to intermittent nasogastric tube feeding method (MD 2.0 g/day; 95% CI 0.5 to 3.5; MD 2.0 g/day; 95% CI 0.2 to 3.8, respectively). A trend toward earlier discharge for infants less than 1000 grams birth weight fed by the continuous tube feeding method compared to intermittent nasogastric tube feeding method (MD -11 days; 95% CI -21.8 to -0.2). Small sample sizes, methodologic limitations, inconsistencies in controlling variables that may affect outcomes, and conflicting results of the studies to date make it difficult to make universal recommendations regarding the best tube feeding method for premature infants less than 1500 grams. The clinical benefits and risks of continuous versus intermittent nasogastric tube milk feeding cannot be reliably discerned from the limited information available from randomised trials to date.
Elastic models: a comparative study applied to retinal images.

PubMed

Karali, E; Lambropoulou, S; Koutsouris, D

2011-01-01

In this work various methods of parametric elastic models are compared, namely the classical snake, the gradient vector field snake (GVF snake) and the topology-adaptive snake (t-snake), as well as the method of self-affine mapping system as an alternative to elastic models. We also give a brief overview of the methods used. The self-affine mapping system is implemented using an adapting scheme and minimum distance as optimization criterion, which is more suitable for weak edges detection. All methods are applied to glaucomatic retinal images with the purpose of segmenting the optical disk. The methods are compared in terms of segmentation accuracy and speed, as these are derived from cross-correlation coefficients between real and algorithm extracted contours and segmentation time, respectively. As a result, the method of self-affine mapping system presents adequate segmentation time and segmentation accuracy, and significant independence from initialization.
Comparative analysis of methods for concentrating venom from jellyfish Rhopilema esculentum Kishinouye

NASA Astrophysics Data System (ADS)

Li, Cuiping; Yu, Huahua; Feng, Jinhua; Chen, Xiaolin; Li, Pengcheng

2009-02-01

In this study, several methods were compared for the efficiency to concentrate venom from the tentacles of jellyfish Rhopilema esculentum Kishinouye. The results show that the methods using either freezing-dry or gel absorption to remove water to concentrate venom are not applicable due to the low concentration of the compounds dissolved. Although the recovery efficiency and the total venom obtained using the dialysis dehydration method are high, some proteins can be lost during the concentrating process. Comparing to the lyophilization method, ultrafiltration is a simple way to concentrate the compounds at high percentage but the hemolytic activities of the proteins obtained by ultrafiltration appear to be lower. Our results suggest that overall lyophilization is the best and recommended method to concentrate venom from the tentacles of jellyfish. It shows not only the high recovery efficiency for the venoms but high hemolytic activities as well.
A comparison between the dimensions of positive transtibial residual limb molds prepared by air pressure casting and weight-bearing casting methods.

PubMed

Hajiaghaei, Behnam; Ebrahimi, Ismail; Kamyab, Mojtaba; Saeedi, Hassan; Jalali, Maryam

2016-01-01

Creating a socket with proper fit is an important factor to ensure the comfort and control of prosthetic devices. Several techniques are commonly used to cast transtibial stumps but their effect on stump shape deformation is not well understood. This study compares the dimensions, circumferences and volumes of the positive casts and also the socket comfort between two casting methods. Our hypothesis was that the casts prepared by air pressure method have less volume and are more comfortable than those prepared by weight bearing method. Fifteen transtibial unilateral amputees participated in the study. Two weight bearing and air pressure casting methods were utilized for their residual limbs. The diameters and circumferences of various areas of the residual limbs and positive casts were compared. The volumes of two types of casts were measured by a volumeter and compared. Visual Analogue Scale (VAS) was used to measure the sockets fit comfort. Circumferences at 10 and 15 cm below the patella on the casts were significantly smaller in air pressure casting method compared to the weight bearing method (p=0.00 and 0.01 respectively). The volume of the cast in air pressure method was lower than that of the weight bearing method (p=0.006). The amputees found the fit of the sockets prepared by air pressure method more comfortable than the weight bearing sockets (p=0.015). The air pressure casting reduced the circumferences of the distal portion of residual limbs which has more soft tissue and because of its snug fit it provided more comfort for amputees, according to the VAS measurements.
Rapid comparison of properties on protein surface

PubMed Central

Sael, Lee; La, David; Li, Bin; Rustamov, Raif; Kihara, Daisuke

2008-01-01

The mapping of physicochemical characteristics onto the surface of a protein provides crucial insights into its function and evolution. This information can be further used in the characterization and identification of similarities within protein surface regions. We propose a novel method which quantitatively compares global and local properties on the protein surface. We have tested the method on comparison of electrostatic potentials and hydrophobicity. The method is based on 3D Zernike descriptors, which provides a compact representation of a given property defined on a protein surface. Compactness and rotational invariance of this descriptor enable fast comparison suitable for database searches. The usefulness of this method is exemplified by studying several protein families including globins, thermophilic and mesophilic proteins, and active sites of TIM β/α barrel proteins. In all the cases studied, the descriptor is able to cluster proteins into functionally relevant groups. The proposed approach can also be easily extended to other surface properties. This protein surface-based approach will add a new way of viewing and comparing proteins to conventional methods, which compare proteins in terms of their primary sequence or tertiary structure. PMID:18618695
Rapid comparison of properties on protein surface.

PubMed

Sael, Lee; La, David; Li, Bin; Rustamov, Raif; Kihara, Daisuke

2008-10-01

The mapping of physicochemical characteristics onto the surface of a protein provides crucial insights into its function and evolution. This information can be further used in the characterization and identification of similarities within protein surface regions. We propose a novel method which quantitatively compares global and local properties on the protein surface. We have tested the method on comparison of electrostatic potentials and hydrophobicity. The method is based on 3D Zernike descriptors, which provides a compact representation of a given property defined on a protein surface. Compactness and rotational invariance of this descriptor enable fast comparison suitable for database searches. The usefulness of this method is exemplified by studying several protein families including globins, thermophilic and mesophilic proteins, and active sites of TIM beta/alpha barrel proteins. In all the cases studied, the descriptor is able to cluster proteins into functionally relevant groups. The proposed approach can also be easily extended to other surface properties. This protein surface-based approach will add a new way of viewing and comparing proteins to conventional methods, which compare proteins in terms of their primary sequence or tertiary structure.
Implementation of density functional theory method on object-oriented programming (C++) to calculate energy band structure using the projector augmented wave (PAW)

NASA Astrophysics Data System (ADS)

Alfianto, E.; Rusydi, F.; Aisyah, N. D.; Fadilla, R. N.; Dipojono, H. K.; Martoprawiro, M. A.

2017-05-01

This study implemented DFT method into the C++ programming language with object-oriented programming rules (expressive software). The use of expressive software results in getting a simple programming structure, which is similar to mathematical formula. This will facilitate the scientific community to develop the software. We validate our software by calculating the energy band structure of Silica, Carbon, and Germanium with FCC structure using the Projector Augmented Wave (PAW) method then compare the results to Quantum Espresso calculation’s results. This study shows that the accuracy of the software is 85% compared to Quantum Espresso.
The Effect of Teaching Medical Ethics on Medical Students' Moral Reasoning.

ERIC Educational Resources Information Center

Self, Donnie J; And Others

1989-01-01

A study of the effect of incorporating medical ethics into the medical curriculum and comparing two teaching methods (lecture and case studies) found higher moral reasoning after instruction, but neither method was significantly more effective. (Author/MSE)
Comparing Results from Constant Comparative and Computer Software Methods: A Reflection about Qualitative Data Analysis

ERIC Educational Resources Information Center

Putten, Jim Vander; Nolen, Amanda L.

2010-01-01

This study compared qualitative research results obtained by manual constant comparative analysis with results obtained by computer software analysis of the same data. An investigated about issues of trustworthiness and accuracy ensued. Results indicated that the inductive constant comparative data analysis generated 51 codes and two coding levels…
Comparison of Floseal(r) and electrocautery in hemostasis after total knee arthroplasty

PubMed Central

Helito, Camilo Partezani; Gobbi, Riccardo Gomes; Castrillon, Lucas Machado; Hinkel, Betina Bremer; Pécora, José Ricardo; Camanho, Gilberto Luis

2013-01-01

Objective To evaluate whether hemostasis with eletrocauterization in comparison with Floseal(r) leads to different bleeding rates during total knee arthroplasty. Methods A comparative study was performed between two groups: group with ten consecutive total knee arthroplasties with Floseal(r) used as hemostatic method and control group with ten consecutive total knee arthroplasties with eletrocauterization as hemostatic method. Bleeding parameters such as debit of the drain, liquid infusion and blood transfusion rate were recorded. Results Floseal(r) group received less blood transfusion, less liquid infusion and lower drainage in absolute numbers compared to the control group. However, no parameter was statistically significant. Conclusion Hemostasis with Floseal(r) is as effective as hemostasis with eletrocauterization, what makes it a viable alternative to patients with contraindication to electric scalpel use. Level of Evidence II, Prospective Comparative Study. PMID:24453689
Evaluation of Existing Methods for Human Blood mRNA Isolation and Analysis for Large Studies

PubMed Central

Meyer, Anke; Paroni, Federico; Günther, Kathrin; Dharmadhikari, Gitanjali; Ahrens, Wolfgang; Kelm, Sørge; Maedler, Kathrin

2016-01-01

Aims Prior to implementing gene expression analyses from blood to a larger cohort study, an evaluation to set up a reliable and reproducible method is mandatory but challenging due to the specific characteristics of the samples as well as their collection methods. In this pilot study we optimized a combination of blood sampling and RNA isolation methods and present reproducible gene expression results from human blood samples. Methods The established PAXgeneTM blood collection method (Qiagen) was compared with the more recent TempusTM collection and storing system. RNA from blood samples collected by both systems was extracted on columns with the corresponding Norgen and PAX RNA extraction Kits. RNA quantity and quality was compared photometrically, with Ribogreen and by Real-Time PCR analyses of various reference genes (PPIA, β-ACTIN and TUBULIN) and exemplary of SIGLEC-7. Results Combining different sampling methods and extraction kits caused strong variations in gene expression. The use of PAXgeneTM and TempusTM collection systems resulted in RNA of good quality and quantity for the respective RNA isolation system. No large inter-donor variations could be detected for both systems. However, it was not possible to extract sufficient RNA of good quality with the PAXgeneTM RNA extraction system from samples collected by TempusTM collection tubes. Comparing only the Norgen RNA extraction methods, RNA from blood collected either by the TempusTM or PAXgeneTM collection system delivered sufficient amount and quality of RNA, but the TempusTM collection delivered higher RNA concentration compared to the PAXTM collection system. The established Pre-analytix PAXgeneTM RNA extraction system together with the PAXgeneTM blood collection system showed lowest CT-values, i.e. highest RNA concentration of good quality. Expression levels of all tested genes were stable and reproducible. Conclusions This study confirms that it is not possible to mix or change sampling or extraction strategies during the same study because of large variations of RNA yield and expression levels. PMID:27575051
Cotton Study: Albumin Binding and its Effect on Elastase Activity in the Chronic Non-healing Wound

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

Castro, Nathan J.; Goheen, Steven C.

A comparative examination of two methods, the classical- and chromatographic, commonly used to study adsorption isotherms is presented. Both methods were used to study the solid/liquid interface of two different derivatives of cotton fiber and bovine serum albumin (BSA).
Comparing the Similarity of Responses Received from Studies in Amazon’s Mechanical Turk to Studies Conducted Online and with Direct Recruitment

PubMed Central

Bartneck, Christoph; Duenser, Andreas; Moltchanova, Elena; Zawieska, Karolina

2015-01-01

Computer and internet based questionnaires have become a standard tool in Human-Computer Interaction research and other related fields, such as psychology and sociology. Amazon’s Mechanical Turk (AMT) service is a new method of recruiting participants and conducting certain types of experiments. This study compares whether participants recruited through AMT give different responses than participants recruited through an online forum or recruited directly on a university campus. Moreover, we compare whether a study conducted within AMT results in different responses compared to a study for which participants are recruited through AMT but which is conducted using an external online questionnaire service. The results of this study show that there is a statistical difference between results obtained from participants recruited through AMT compared to the results from the participant recruited on campus or through online forums. We do, however, argue that this difference is so small that it has no practical consequence. There was no significant difference between running the study within AMT compared to running it with an online questionnaire service. There was no significant difference between results obtained directly from within AMT compared to results obtained in the campus and online forum condition. This may suggest that AMT is a viable and economical option for recruiting participants and for conducting studies as setting up and running a study with AMT generally requires less effort and time compared to other frequently used methods. We discuss our findings as well as limitations of using AMT for empirical studies. PMID:25876027
Comparing the similarity of responses received from studies in Amazon's Mechanical Turk to studies conducted online and with direct recruitment.

PubMed

Bartneck, Christoph; Duenser, Andreas; Moltchanova, Elena; Zawieska, Karolina

2015-01-01

Computer and internet based questionnaires have become a standard tool in Human-Computer Interaction research and other related fields, such as psychology and sociology. Amazon's Mechanical Turk (AMT) service is a new method of recruiting participants and conducting certain types of experiments. This study compares whether participants recruited through AMT give different responses than participants recruited through an online forum or recruited directly on a university campus. Moreover, we compare whether a study conducted within AMT results in different responses compared to a study for which participants are recruited through AMT but which is conducted using an external online questionnaire service. The results of this study show that there is a statistical difference between results obtained from participants recruited through AMT compared to the results from the participant recruited on campus or through online forums. We do, however, argue that this difference is so small that it has no practical consequence. There was no significant difference between running the study within AMT compared to running it with an online questionnaire service. There was no significant difference between results obtained directly from within AMT compared to results obtained in the campus and online forum condition. This may suggest that AMT is a viable and economical option for recruiting participants and for conducting studies as setting up and running a study with AMT generally requires less effort and time compared to other frequently used methods. We discuss our findings as well as limitations of using AMT for empirical studies.
Comparative evaluation of two methods of enumerating enterococci in foods: collaborative study.

PubMed

Peterz, M; Steneryd, A C

1993-05-01

Two methods of enumerating enterococci in foods were compared in a collaborative study. Thirteen laboratories tested four blind duplicate samples containing different levels of enterococci and two negative control samples. Freeze-dried mixtures of bacteria were used as simulated food samples. The freeze-dried samples were reconstituted and either spread directly on the surface of Slanetz and Bartley medium (SB) and incubated at 44 degrees C for 48 h or preincubated in tryptone soya agar at 37 degrees C for 2 h before being overlaid by SB and incubated at 37 degrees C for a further 46 h. The numbers CFU of enterococci recovered by the two methods were not significantly different except for one sample where the 37 degrees C method gave a somewhat higher recovery. The 44 degrees C method was less time-consuming and less laborious.
Incidence and degree of Salmonella Heidelberg colonization of day old broiler chicks using several methods of inoculation

USDA-ARS?s Scientific Manuscript database

Before beginning a study that involves a large number of birds, it may be helpful to know what method of inoculation would be best for the experiment in question. The objective of this study was to compare several methods of Salmonella challenge (oral gavage, intracloacal inoculation and the seeder ...
Comparison of Nonoverlap Methods for Identifying Treatment Effect in Single-Subject Experimental Research

ERIC Educational Resources Information Center

Rakap, Salih; Snyder, Patricia; Pasia, Cathleen

2014-01-01

Debate is occurring about which result interpretation aides focused on examining the experimental effect should be used in single-subject experimental research. In this study, we examined seven nonoverlap methods and compared results using each method to judgments of two visual analysts. The data sources for the present study were 36 studies…
Personalized Introductory Courses: A Longitudinal Study. OASIS Research Report No. 1.

ERIC Educational Resources Information Center

Hedges, Larry V.

This study investigated the long term effects of the Personalized System of Instruction (PSI) method at the University of California, San Diego. Groups of 139 and 137 undergraduate students took three physics courses taught by either the PSI method or the lecture/discussion method. Students from these groups were compared in two subsequent…
Comparison of Three Tobacco Survey Methods with College Students: A Case Study

ERIC Educational Resources Information Center

James, Delores C. S.; Chen, W. William; Sheu, Jiunn-Jye

2005-01-01

The goals of this case study were to: (1) determine the efficiency and effectiveness of three survey methods--postal mail survey, web-based survey, and random in-class administration survey--in assessing tobacco-related attitudes and behaviors among college students and (2) compare the response rate and procedures of these three methods. There was…

Effect of Two Different Methods of Initiating Atomoxetine on the Adverse Event Profile of Atomoxetine

ERIC Educational Resources Information Center

Greenhill, Laurence L.; Newcorn, Jeffrey H.; Gao, Haitao; Feldman, Peter D.

2007-01-01

Objective: To compare the effects of two different methods for initiating atomoxetine in terms of the incidence of early adverse events. Method: Data on atomoxetine treatment-emergent adverse events in youths, ages 6 to 18 years, were analyzed from five randomized, double-blind, placebo-controlled, acute-phase studies. Two studies involve…
Quantifying the accuracy of the tumor motion and area as a function of acceleration factor for the simulation of the dynamic keyhole magnetic resonance imaging method.

PubMed

Lee, Danny; Greer, Peter B; Pollock, Sean; Kim, Taeho; Keall, Paul

2016-05-01

The dynamic keyhole is a new MR image reconstruction method for thoracic and abdominal MR imaging. To date, this method has not been investigated with cancer patient magnetic resonance imaging (MRI) data. The goal of this study was to assess the dynamic keyhole method for the task of lung tumor localization using cine-MR images reconstructed in the presence of respiratory motion. The dynamic keyhole method utilizes a previously acquired a library of peripheral k-space datasets at similar displacement and phase (where phase is simply used to determine whether the breathing is inhale to exhale or exhale to inhale) respiratory bins in conjunction with central k-space datasets (keyhole) acquired. External respiratory signals drive the process of sorting, matching, and combining the two k-space streams for each respiratory bin, thereby achieving faster image acquisition without substantial motion artifacts. This study was the first that investigates the impact of k-space undersampling on lung tumor motion and area assessment across clinically available techniques (zero-filling and conventional keyhole). In this study, the dynamic keyhole, conventional keyhole and zero-filling methods were compared to full k-space dataset acquisition by quantifying (1) the keyhole size required for central k-space datasets for constant image quality across sixty four cine-MRI datasets from nine lung cancer patients, (2) the intensity difference between the original and reconstructed images in a constant keyhole size, and (3) the accuracy of tumor motion and area directly measured by tumor autocontouring. For constant image quality, the dynamic keyhole method, conventional keyhole, and zero-filling methods required 22%, 34%, and 49% of the keyhole size (P < 0.0001), respectively, compared to the full k-space image acquisition method. Compared to the conventional keyhole and zero-filling reconstructed images with the keyhole size utilized in the dynamic keyhole method, an average intensity difference of the dynamic keyhole reconstructed images (P < 0.0001) was minimal, and resulted in the accuracy of tumor motion within 99.6% (P < 0.0001) and the accuracy of tumor area within 98.0% (P < 0.0001) for lung tumor monitoring applications. This study demonstrates that the dynamic keyhole method is a promising technique for clinical applications such as image-guided radiation therapy requiring the MR monitoring of thoracic tumors. Based on the results from this study, the dynamic keyhole method could increase the imaging frequency by up to a factor of five compared with full k-space methods for real-time lung tumor MRI.
Comparative effectiveness research methodology using secondary data: A starting user's guide.

PubMed

Sun, Maxine; Lipsitz, Stuart R

2018-04-01

The use of secondary data, such as claims or administrative data, in comparative effectiveness research has grown tremendously in recent years. We believe that the current review can help investigators relying on secondary data to (1) gain insight into both the methodologies and statistical methods, (2) better understand the necessity of a rigorous planning before initiating a comparative effectiveness investigation, and (3) optimize the quality of their investigations. Specifically, we review concepts of adjusted analyses and confounders, methods of propensity score analyses, and instrumental variable analyses, risk prediction models (logistic and time-to-event), decision-curve analysis, as well as the interpretation of the P value and hypothesis testing. Overall, we hope that the current review article can help research investigators relying on secondary data to perform comparative effectiveness research better understand the necessity of a rigorous planning before study start, and gain better insight in the choice of statistical methods so as to optimize the quality of the research study. Copyright © 2017 Elsevier Inc. All rights reserved.
Quantitative versus qualitative cultures of respiratory secretions for clinical outcomes in patients with ventilator-associated pneumonia.

PubMed

Berton, Danilo Cortozi; Kalil, Andre C; Cavalcanti, Manuela; Teixeira, Paulo José Zimermann

2008-10-08

Ventilator-associated pneumonia (VAP) is a common infectious disease in intensive care units (ICUs). The best diagnostic approach to resolve this condition remains uncertain. To evaluate whether quantitative cultures of respiratory secretions are effective in reducing mortality in immunocompetent patients with VAP, compared with qualitative cultures. We also considered changes in antibiotic use, length of ICU stay and mechanical ventilation. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, issue 4), which contains the Acute Respiratory Infections Group's Specialized Register; MEDLINE (1966 to December 2007); EMBASE (1974 to December 2007); and LILACS (1982 to December 2007). Randomized controlled trials (RCTs) comparing respiratory samples processed quantitatively or qualitatively, obtained by invasive or non-invasive methods from immunocompetent patients with VAP, and which analyzed the impact of these methods on antibiotic use and mortality rates. Two review authors independently reviewed and selected trials from the search results, and assessed studies for suitability, methodology and quality. We analyzed data using Review Manager software. We pooled the included studies to yield the risk ratio (RR) for mortality and antibiotic change with 95% confidence intervals (CI). Of the 3931 references identified from the electronic databases, five RCTs (1367 patients) met the inclusion criteria. Three studies compared invasive methods using quantitative cultures versus non-invasive methods using qualitative cultures, and were used to answer the main objective of this review. The other two studies compared invasive versus non-invasive methods, both using quantitative cultures. All five studies were combined to compare invasive versus non-invasive interventions for diagnosing VAP. The studies that compared quantitative and qualitative cultures (1240 patients) showed no statistically significant differences in mortality rates (RR = 0.91, 95% CI 0.75 to 1.11). The analysis of all five RCTs showed there was no evidence of mortality reduction in the invasive group versus the non-invasive group (RR = 0.93, 95% CI 0.78 to 1.11). There were no significant differences between the interventions with respect to the number of days on mechanical ventilation, length of ICU stay or antibiotic change. There is no evidence that the use of quantitative cultures of respiratory secretions results in reduced mortality, reduced time in ICU and on mechanical ventilation, or higher rates of antibiotic change when compared to qualitative cultures in patients with VAP. Similar results were observed when invasive strategies were compared with non-invasive strategies.
A Comparative Investigation of the Efficiency of Two Classroom Observational Methods.

ERIC Educational Resources Information Center

Kissel, Mary Ann

The problem of this study was to determine whether Method A is a more efficient observational method for obtaining activity type behaviors in an individualized classroom than Method B. Method A requires the observer to record the activities of the entire class at given intervals while Method B requires only the activities of selected individuals…
VOLATILE CONSTITUENTS OF GINGER OIL PREPARED ACCORDING TO IRANIAN TRADITIONAL MEDICINE AND CONVENTIONAL METHOD: A COMPARATIVE STUDY.

PubMed

Shirooye, Pantea; Mokaberinejad, Roshanak; Ara, Leila; Hamzeloo-Moghadam, Maryam

2016-01-01

Herbal medicines formulated as oils were believed to possess more powerful effects than their original plants in Iranian Traditional Medicine (ITM). One of the popular oils suggested for treatment of various indications was ginger oil. In the present study, to suggest a more convenient method of oil preparation (compared to the traditional method), ginger oil has been prepared according to both the traditional and conventional maceration methods and the volatile oil constituents have been compared. Ginger oil was obtained in sesame oil according to both the traditional way and the conventional (maceration) methods. The volatile oil of dried ginger and both oils were obtained by hydro-distillation and analyzed by gas chromatography/mass spectroscopy. Fifty five, fifty nine and fifty one components consisting 94 %, 94 % and 98 % of the total compounds were identified in the volatile oil of ginger, traditional and conventional oils, respectively. The most dominant compounds of the traditional and conventional oils were almost similar; however they were different from ginger essential oil which has also been to possess limited amounts of anti-inflammatory components. It was concluded that ginger oil could be prepared through maceration method and used for indications mentioned in ITM.
Evaluation of dysphagia in early stroke patients by bedside, endoscopic, and electrophysiological methods.

PubMed

Umay, Ebru Karaca; Unlu, Ece; Saylam, Guleser Kılıc; Cakci, Aytul; Korkmaz, Hakan

2013-09-01

We aimed in this study to evaluate dysphagia in early stroke patients using a bedside screening test and flexible fiberoptic endoscopic evaluation of swallowing (FFEES) and electrophysiological evaluation (EE) methods and to compare the effectiveness of these methods. Twenty-four patients who were hospitalized in our clinic within the first 3 months after stroke were included in this study. Patients were evaluated using a bedside screening test [including bedside dysphagia score (BDS), neurological examination dysphagia score (NEDS), and total dysphagia score (TDS)] and FFEES and EE methods. Patients were divided into normal-swallowing and dysphagia groups according to the results of the evaluation methods. Patients with dysphagia as determined by any of these methods were compared to the patients with normal swallowing based on the results of the other two methods. Based on the results of our study, a high BDS was positively correlated with dysphagia identified by FFEES and EE methods. Moreover, the FFEES and EE methods were positively correlated. There was no significant correlation between NEDS and TDS levels and either EE or FFEES method. Bedside screening tests should be used mainly as an initial screening test; then FFEES and EE methods should be combined in patients who show risks. This diagnostic algorithm may provide a practical and fast solution for selected stroke patients.
Determination of the Residual Anthracene Concentration in Cultures of Haloalkalitolerant Actinomycetes by Excitation Fluorescence, Emission Fluorescence, and Synchronous Fluorescence: Comparative Study

PubMed Central

Lara-Severino, Reyna del Carmen; Camacho-López, Miguel Ángel; García-Macedo, Jessica Marlene; Gómez-Oliván, Leobardo M.; Sandoval-Trujillo, Ángel H.; Isaac-Olive, Keila; Ramírez-Durán, Ninfa

2016-01-01

Polycyclic aromatic hydrocarbons (PAHs) are compounds that can be quantified by fluorescence due to their high quantum yield. Haloalkalitolerant bacteria tolerate wide concentration ranges of NaCl and pH. They are potentially useful in the PAHs bioremediation of saline environments. However, it is known that salinity of the sample affects fluorescence signal regardless of the method. The objective of this work was to carry out a comparative study based on the sensitivity, linearity, and detection limits of the excitation, emission, and synchronous fluorescence methods, during the quantification of the residual anthracene concentration from the following haloalkalitolerant actinomycetes cultures Kocuria rosea, Kocuria palustris, Microbacterium testaceum, and 4 strains of Nocardia farcinica, in order to establish the proper fluorescence method to study the PAHs biodegrading capacity of haloalkalitolerant actinobacteria. The study demonstrated statistical differences among the strains and among the fluorescence methods regarding the anthracene residual concentration. The results showed that excitation and emission fluorescence methods performed very similarly but sensitivity in excitation fluorescence is slightly higher. Synchronous fluorescence using Δλ = 150 nm is not the most convenient method. Therefore we propose the excitation fluorescence as the fluorescence method to be used in the study of the PAHs biodegrading capacity of haloalkalitolerant actinomycetes. PMID:26925294
Leaching of indium from obsolete liquid crystal displays: Comparing grinding with electrical disintegration in context of LCA

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

Dodbiba, Gjergj, E-mail: dodbiba@sys.t.u-tokyo.ac.jp; Nagai, Hiroki; Wang Lipang

2012-10-15

Highlights: Black-Right-Pointing-Pointer Two pre-treatment methods, prior to leaching of indium from obsolete LCD modules, were described. Black-Right-Pointing-Pointer Conventional grinding and electrical disintegration have been evaluated and compared in the context of LCA. Black-Right-Pointing-Pointer Experimental data on the leaching capacity for indium and the electricity consumption of equipment were inputted into the LCA model in order to compare the environmental performance of each method. Black-Right-Pointing-Pointer An estimate for the environmental performance was calculated as the sum of six impact categories. Black-Right-Pointing-Pointer Electrical disintegration method outperforms conventional grinding in all impact categories. - Abstract: In order to develop an effective recycling systemmore » for obsolete Liquid Crystal Displays (LCDs), which would enable both the leaching of indium (In) and the recovery of a pure glass fraction for recycling, an effective liberation or size-reduction method would be an important pre-treatment step. Therefore, in this study, two different types of liberation methods: (1) conventional grinding, and (2) electrical disintegration have been tested and evaluated in the context of Life Cycle Assessment (LCA). In other words, the above-mentioned methods were compared in order to find out the one that ensures the highest leaching capacity for indium, as well as the lowest environmental burden. One of the main findings of this study was that the electrical disintegration was the most effective liberation method, since it fully liberated the indium containing-layer, ensuring a leaching capacity of 968.5 mg-In/kg-LCD. In turn, the estimate for the environmental burden was approximately five times smaller when compared with the conventional grinding.« less
Semiquantitative visual approach to scoring lung cancer treatment response using computed tomography: a pilot study.

PubMed

Gottlieb, Ronald H; Kumar, Prasanna; Loud, Peter; Klippenstein, Donald; Raczyk, Cheryl; Tan, Wei; Lu, Jenny; Ramnath, Nithya

2009-01-01

Our objective was to compare a newly developed semiquantitative visual scoring (SVS) method with the current standard, the Response Evaluation Criteria in Solid Tumors (RECIST) method, in the categorization of treatment response and reader agreement for patients with metastatic lung cancer followed by computed tomography. The 18 subjects (5 women and 13 men; mean age, 62.8 years) were from an institutional review board-approved phase 2 study that evaluated a second-line chemotherapy regimen for metastatic (stages III and IV) non-small cell lung cancer. Four radiologists, blinded to the patient outcome and each other's reads, evaluated the change in the patients' tumor burden from the baseline to the first restaging computed tomographic scan using either the RECIST or the SVS method. We compared the numbers of patients placed into the partial response, the stable disease (SD), and the progressive disease (PD) categories (Fisher exact test) and observer agreement (kappa statistic). Requiring the concordance of 3 of the 4 readers resulted in the RECIST placing 17 (100%) of 17 patients in the SD category compared with the SVS placing 9 (60%) of 15 patients in the partial response, 5 (33%) of the 15 patients in the SD, and 1 (6.7%) of the 15 patients in the PD categories (P < 0.0001). Interobserver agreement was higher among the readers using the SVS method (kappa, 0.54; P < 0.0001) compared with that of the readers using the RECIST method (kappa, -0.01; P = 0.5378). Using the SVS method, the readers more finely discriminated between the patient response categories with superior agreement compared with the RECIST method, which could potentially result in large differences in early treatment decisions for advanced lung cancer.
The Americleft Project: A Modification of Asher-McDade Method for Rating Nasolabial Esthetics in Patients With Unilateral Cleft Lip and Palate Using Q-sort.

PubMed

Stoutland, Alicia; Long, Ross E; Mercado, Ana; Daskalogiannakis, John; Hathaway, Ronald R; Russell, Kathleen A; Singer, Emily; Semb, Gunvor; Shaw, William C

2017-11-01

The purpose of this study was to investigate ways to improve rater reliability and satisfaction in nasolabial esthetic evaluations of patients with complete unilateral cleft lip and palate (UCLP), by modifying the Asher-McDade method with use of Q-sort methodology. Blinded ratings of cropped photographs of one hundred forty-nine 5- to 7-year-old consecutively treated patients with complete UCLP from 4 different centers were used in a rating of frontal and profile nasolabial esthetic outcomes by 6 judges involved in the Americleft Project's intercenter outcome comparisons. Four judges rated in previous studies using the original Asher-McDade approach. For the Q-sort modification, rather than projection of images, each judge had cards with frontal and profile photographs of each patient and rated them on a scale of 1 to 5 for vermillion border, nasolabial frontal, and profile, using the Q-sort method with placement of cards into categories 1 to 5. Inter- and intrarater reliabilities were calculated using the Weighted Kappa (95% confidence interval). For 4 raters, the reliabilities were compared with those in previous studies. There was no significant improvement in inter-rater reliabilities using the new method. Intrarater reliability consistently improved. All raters preferred the Q-sort method with rating cards rather than a PowerPoint of photos, which improved internal consistency in rating compared to previous studies using the original Asher-McDade method. All raters preferred this method because of the ability to continuously compare photos and adjust relative ratings between patients.
Performance of the Effective Core Potentials of Ca, Hg and Pb in Complexes with Ligands Containing N and O Donor Atoms.

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

Ramirez, Jose Z.; Vargas, Rubicelia; Garza, Jorge

This paper presents a systematic study of the performance of the relativistic effective core potentials (RECPs) proposed by Stoll-Preuss, Christiansen-Ermler and Hay-Wadt for Ca2+, Hg2+ and Pb2+. The RECPs performance is studied when these cations are combined with ethylene glycol, 2-aminoethanol and ethylenediamine to form bidentate complexes. First, the description of the bidentate ligands is analyzed with the Kohn-Sham method by using SVWN, BLYP and B3LYP exchange-correlation functionals and they are compared with the Moeller-Plesset perturbation theory (MP2), for all these methods the TZVP basis set was used. We found that the BLYP exchange-correlation functional gives similar results that thosemore » obtained by the B3LYP and MP2 methods. Thus, the bidentate metal complexes were studied with the BLYP method combined with the RECPs. In order to compare RECPs performance, all the systems considered in this work were studied with the relativistic all-electron Douglas-Kroll (DK3) method. We observed that the Christiansen-Ermler RECPs give the best energetic and geometrical description for Ca and Hg complexes when compared with the all-electron method. For Pb complexes the spin-orbit interaction and Basis Set Superposition error must be taken into account in the RECP. In general, the trend showed in the complexation energies with the all-electron method is followed by the complexation energies computed with all the pseudopotential tested in this work. Battelle operates PNNL for the USDOE.« less
Classifying four-category visual objects using multiple ERP components in single-trial ERP.

PubMed

Qin, Yu; Zhan, Yu; Wang, Changming; Zhang, Jiacai; Yao, Li; Guo, Xiaojuan; Wu, Xia; Hu, Bin

2016-08-01

Object categorization using single-trial electroencephalography (EEG) data measured while participants view images has been studied intensively. In previous studies, multiple event-related potential (ERP) components (e.g., P1, N1, P2, and P3) were used to improve the performance of object categorization of visual stimuli. In this study, we introduce a novel method that uses multiple-kernel support vector machine to fuse multiple ERP component features. We investigate whether fusing the potential complementary information of different ERP components (e.g., P1, N1, P2a, and P2b) can improve the performance of four-category visual object classification in single-trial EEGs. We also compare the classification accuracy of different ERP component fusion methods. Our experimental results indicate that the classification accuracy increases through multiple ERP fusion. Additional comparative analyses indicate that the multiple-kernel fusion method can achieve a mean classification accuracy higher than 72 %, which is substantially better than that achieved with any single ERP component feature (55.07 % for the best single ERP component, N1). We compare the classification results with those of other fusion methods and determine that the accuracy of the multiple-kernel fusion method is 5.47, 4.06, and 16.90 % higher than those of feature concatenation, feature extraction, and decision fusion, respectively. Our study shows that our multiple-kernel fusion method outperforms other fusion methods and thus provides a means to improve the classification performance of single-trial ERPs in brain-computer interface research.
A comparison of treatment effectiveness between the CAD/CAM method and the manual method for managing adolescent idiopathic scoliosis.

PubMed

Wong, M S; Cheng, J C Y; Lo, K H

2005-04-01

The treatment effectiveness of the CAD/CAM method and the manual method in managing adolescent idiopathic scoliosis (AIS) was compared. Forty subjects were recruited with twenty subjects for each method. The clinical parameters namely Cobb's angle and apical vertebral rotation were evaluated at the pre-brace and the immediate in-brace visits. The results demonstrated that orthotic treatments rendered by the CAD/CAM method and the conventional manual method were effective in providing initial control of Cobb's angle. Significant decreases (p < 0.05) were found between the pre-brace and immediate in-brace visits for both methods. The mean reductions of Cobb's angle were 12.8 degrees (41.9%) for the CAD/CAM method and 9.8 degrees (32.1%) for the manual method. An initial control of the apical vertebral rotation was not shown in this study. In the comparison between the CAD/CAM method and the manual method, no significant difference was found in the control of Cobb's angle and apical vertebral rotation. The current study demonstrated that the CAD/CAM method can provide similar result in the initial stage of treatment as compared with the manual method.
EVALUATION OF THREE CLEANING METHODS FOR REMOVING ASBESTOS FROM CARPET. DETERMINATION OF AIRBORNE ASBESTOS CONCENTRATIONS ASSOCIATED WITH EACH METHOD

EPA Science Inventory

This study was conducted to compare the effectiveness of three cleaning methods to remove asbestos from contaminated carpet and to determine the airborne asbestos concentrations associated with the use of each method. The carpet on which the methods were tested was naturally cont...
Evaluation of winter pothole patching methods.

DOT National Transportation Integrated Search

2014-01-01

The main objective of this study was to evaluate the performance and cost-effectiveness of the tow-behind combination : infrared asphalt heater/reclaimer patching method and compare it to the throw and roll and spray injection methods. To : achieve t...
Kentucky highway rating system

DOT National Transportation Integrated Search

2003-03-01

This study had two goals: 1. Formulate a new method for generating roadway adequacy ratings; 2. Construct an appropriate data set and then test the method by comparing it to the results of the HPMS-AP method. The recommended methodology builds on the...
Comparison of two surface temperature measurement using thermocouples and infrared camera

NASA Astrophysics Data System (ADS)

Michalski, Dariusz; Strąk, Kinga; Piasecka, Magdalena

This paper compares two methods applied to measure surface temperatures at an experimental setup designed to analyse flow boiling heat transfer. The temperature measurements were performed in two parallel rectangular minichannels, both 1.7 mm deep, 16 mm wide and 180 mm long. The heating element for the fluid flowing in each minichannel was a thin foil made of Haynes-230. The two measurement methods employed to determine the surface temperature of the foil were: the contact method, which involved mounting thermocouples at several points in one minichannel, and the contactless method to study the other minichannel, where the results were provided with an infrared camera. Calculations were necessary to compare the temperature results. Two sets of measurement data obtained for different values of the heat flux were analysed using the basic statistical methods, the method error and the method accuracy. The experimental error and the method accuracy were taken into account. The comparative analysis showed that although the values and distributions of the surface temperatures obtained with the two methods were similar but both methods had certain limitations.
A factorial design experiment as a pilot study for noninvasive genetic sampling.

PubMed

Renan, Sharon; Speyer, Edith; Shahar, Naama; Gueta, Tomer; Templeton, Alan R; Bar-David, Shirli

2012-11-01

Noninvasive genetic sampling has increasingly been used in ecological and conservation studies during the last decade. A major part of the noninvasive genetic literature is dedicated to the search for optimal protocols, by comparing different methods of collection, preservation and extraction of DNA from noninvasive materials. However, the lack of quantitative comparisons among these studies and the possibility that different methods are optimal for different systems make it difficult to decide which protocol to use. Moreover, most studies that have compared different methods focused on a single factor - collection, preservation or extraction - while there could be interactions between these factors. We designed a factorial experiment, as a pilot study, aimed at exploring the effect of several collection, preservation and extraction methods, and the interactions between them, on the quality and amplification success of DNA obtained from Asiatic wild ass (Equus hemionus) faeces in Israel. The amplification success rates of one mitochondrial DNA and four microsatellite markers differed substantially as a function of collection, preservation and extraction methods and their interactions. The most efficient combination for our system integrated the use of swabs as a collection method with preservation at -20 °C and with the Qiagen DNA Stool Kit with modifications as the DNA extraction method. The significant interaction found between the collection, preservation methods and the extraction methods reinforces the importance of conducting a factorial design experiment, rather than examining each factor separately, as a pilot study before initiating a full-scale noninvasive research project. © 2012 Blackwell Publishing Ltd.
Preliminary evaluation of a gel tube agglutination major cross-match method in dogs.

PubMed

Villarnovo, Dania; Burton, Shelley A; Horney, Barbara S; MacKenzie, Allan L; Vanderstichel, Raphaël

2016-09-01

A major cross-match gel tube test is available for use in dogs yet has not been clinically evaluated. This study compared cross-match results obtained using the gel tube and the standard tube methods for canine samples. Study 1 included 107 canine sample donor-recipient pairings cross-match tested with the RapidVet-H method gel tube test and compared results with the standard tube method. Additionally, 120 pairings using pooled sera containing anti-canine erythrocyte antibody at various concentrations were tested with leftover blood from a hospital population to assess sensitivity and specificity of the gel tube method in comparison with the standard method. The gel tube method had a good relative specificity of 96.1% in detecting lack of agglutination (compatibility) compared to the standard tube method. Agreement between the 2 methods was moderate. Nine of 107 pairings showed agglutination/incompatibility on either test, too few to allow reliable calculation of relative sensitivity. Fifty percent of the gel tube method results were difficult to interpret due to sample spreading in the reaction and/or negative control tubes. The RapidVet-H method agreed with the standard cross-match method on compatible samples, but detected incompatibility in some sample pairs that were compatible with the standard method. Evaluation using larger numbers of incompatible pairings is needed to assess diagnostic utility. The gel tube method results were difficult to categorize due to sample spreading. Weak agglutination reactions or other factors such as centrifuge model may be responsible. © 2016 American Society for Veterinary Clinical Pathology.

[Meta-analysis of needle-knife treatment on cervical spondylosis].

PubMed

Kan, Li-Li; Wang, Hai-Dong; Liu, An-Guo

2013-11-01

To assess the efficacy of cervical spondylosis by needle-knife treatment according to the correlated literature of RCT,to compare advantages of needle-knife treatment. Randomized Controlled Trials about needle-knife treatment of cervical spondylosis were indexed from Chinese HowNet (CNKI) and Wanfang (WF) from 2000 to 2012, then were analyzed the efficacy by Review Manager 5.1 software. A total of 13 RCT literatures and 1 419 patients were included. The methods of included studies were poor in quality evaluation because of large sample and multi-center RCT studies was lacked, randomization method was not accurate enough, diagnostic criteria and efficacy evaluation were various, only four studies described long-term efficacy, most of the literature didn't describe the adverse event and fall off,all studies did not use the blind method. The Meta analysis outcome showed overall efficiency of needle-knife therapy was better than acupuncture and traction. Needle-knife therapy compared with Acupuncture, the total RR = 0.19, 95% confidence interval was (0.15, 0.24), P < 0.000.01. Compared with traction therapy the total RR = 1.30, 95% confidence intervalwas (1.18,1.42), P < 0.00001. Compared with acupuncture therapy,the overall effectiveness of needle-knife therapy is higher;compared with traction therapy, although,needle-knife therapy has a high overall effectiveness, but because of the loss of total sample size, the outcome RCT researches to confirm.
Comparison of Methods for Adjusting Incorrect Assignments of Items to Subtests: Oblique Multiple Group Method versus Confirmatory Common Factor Method

ERIC Educational Resources Information Center

Stuive, Ilse; Kiers, Henk A. L.; Timmerman, Marieke E.

2009-01-01

A common question in test evaluation is whether an a priori assignment of items to subtests is supported by empirical data. If the analysis results indicate the assignment of items to subtests under study is not supported by data, the assignment is often adjusted. In this study the authors compare two methods on the quality of their suggestions to…
Introducing conjoint analysis method into delayed lotteries studies: its validity and time stability are higher than in adjusting.

PubMed

Białek, Michał; Markiewicz, Łukasz; Sawicki, Przemysław

2015-01-01

The delayed lotteries are much more common in everyday life than are pure lotteries. Usually, we need to wait to find out the outcome of the risky decision (e.g., investing in a stock market, engaging in a relationship). However, most research has studied the time discounting and probability discounting in isolation using the methodologies designed specifically to track changes in one parameter. Most commonly used method is adjusting, but its reported validity and time stability in research on discounting are suboptimal. The goal of this study was to introduce the novel method for analyzing delayed lotteries-conjoint analysis-which hypothetically is more suitable for analyzing individual preferences in this area. A set of two studies compared the conjoint analysis with adjusting. The results suggest that individual parameters of discounting strength estimated with conjoint have higher predictive value (Study 1 and 2), and they are more stable over time (Study 2) compared to adjusting. We discuss these findings, despite the exploratory character of reported studies, by suggesting that future research on delayed lotteries should be cross-validated using both methods.
Comparative release studies on suppositories using the basket, paddle, dialysis tubing and flow-through cell methods I. Acetaminophen in a lipophilic base suppository.

PubMed

Hori, Seiichi; Kawada, Tsubasa; Kogure, Sanae; Yabu, Shinako; Mori, Kenji; Akimoto, Masayuki

2017-02-01

The release characteristics of lipophilic suppositories containing acetaminophen (AAP) were examined using four types of dissolution methods: the basket, paddle, dialysis tubing (DT) and flow-through cell (FTC) methods. The suitability of each apparatus for quality control in AAP compounded suppositories was evaluated using statistical procedures. More than 80% of the drug was released over 60 min in all the release methods studied, with the exception of the basket method. Reproducible and faster release was achieved using the paddle method at 100 and 200 rpm, whereas poor release occurred with the basket method. The mean dissolution time (MDT), maximum dissolved quantity of AAP at the end of the sampling time (Q) and dissolution efficiency (DE) were calculated by model-independent methods. The FTC method with a single chamber used in this study was also appreciable for AAP suppositories (Q of 100%, MDT of 71-91 min and DE of 75-80%). The DT apparatus is considered similar to the FTC apparatus from a quality control perspective for judging the release properties of lipophilic base suppositories containing AAP. However, even the single chamber FTC used in this study has potential as an in vitro drug release test for suppositories. The comparative dissolution method is expected to become one of the valuable tools for selecting an adequate dissolution test.
Systematic study for DNA recovery and profiling from common IED substrates: From laboratory to casework.

PubMed

Phetpeng, Sukanya; Kitpipit, Thitika; Thanakiatkrai, Phuvadol

2015-07-01

Improvised explosive devices (IEDs) made from household items are encountered in terrorist attacks worldwide. Assembling an IED leaves trace DNA on its components, but deflagration degrades DNA. To maximize the amount of DNA recovered, a systematic evaluation of DNA collection methods was carried out and the most efficient methods were implemented with IED casework evidence as a validation exercise. Six swab types and six moistening agents were used to collect dried buffy coat stains on four common IED substrates. The most efficient swab/moistening agent combinations were then compared with tape-lifting using three brands of adhesive tape and also with direct DNA extraction from evidence. The most efficient collection methods for different IED substrates (post-study protocol) were then implemented for IED casework and compared with the pre-study protocol using 195 pieces of IED evidence. There was no single best swab type or moistening agent. Swab type had the largest effect on DNA recovery percentages, but moistening agents, substrates, and the interactions between factors all affected DNA recovery. The most efficient swab/moistening agent combinations performed equally well when compared with the best adhesive tape and direct extraction. The post-study protocol significantly improved STR profiles obtained from IED evidence. This paper outlines a comprehensive study of DNA collection methods for trace DNA and the validation of the most efficient collection methods with IED evidence. The findings from both parts of this study emphasize the need to continuously re-evaluate standard operating protocols with empirical studies. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
A semi-blinded study comparing 2 methods of measuring nasal potential difference: Subcutaneous needle versus dermal abrasion.

PubMed

De Wachter, E; De Schutter, I; Meulemans, A; Buyl, R; Malfroot, A

2016-01-01

According to European and US protocols, two nasal potential difference (NPD) measurement methods are considered acceptable, although they have not been formally compared: subcutaneous agar-filled needle with calomel (Ndl) and dermal abrasion with conducting cream and Ag/AgCl electrodes (Abr). We compared both in CF and healthy volunteers (HV), assessing their discriminative value and subject's preference. Twelve classic CF and 17 HV underwent both NPD methods, performed by one operator in random order. A written questionnaire, assessing preference, was completed after each test. Tracings were coded, scored in a semi-blinded fashion and categorised as CF/non-CF. 110 tracings (56 Ndl/54 Abr) were collected: 42/110 scored CF and 68/110 non-CF, showing a good correlation. No significant preference for either method was reported. Both NPD methods are similar in terms of discriminative value and subject's preference, comparing classical CF and HV. For diagnosing CF, the operator's preferred NPD-method may be used. Copyright © 2015 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.
Comparative Analysis of Registered Nurses' and Nursing Students' Attitudes and Use of Nonpharmacologic Methods of Pain Management.

PubMed

Stewart, Malcolm; Cox-Davenport, Rebecca A

2015-08-01

Despite the benefits that nonpharmacologic methods of pain management have to offer, nurses cite barriers that inhibit their use in practice. The purpose of this research study was to compare the perceptions of prelicensed student nurses (SNs) and registered nurses (RNs) toward nonpharmacologic methods of pain management. A sample size of 64 students and 49 RNs was recruited. Each participant completed a questionnaire about their use and perceptions nonpharmacologic pain control methods. Sixty-nine percent of RNs reported a stronger belief that nonpharmacologic methods gave relief to their patients compared with 59% of SNs (p = .028). Seventy-five percent of student nurses felt they had adequate education about nonpharmacologic pain modalities compared with 51% of RN who felt less than adequately educated (p = .016). These findings highlight the need for education about nonpharmacologic approaches to pain management. Applications of these findings may decrease barriers to the use of nonpharmacologic methods of pain management. Copyright © 2015 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.
A comparative laboratory diagnosis of malaria: microscopy versus rapid diagnostic test kits.

PubMed

Azikiwe, C C A; Ifezulike, C C; Siminialayi, I M; Amazu, L U; Enye, J C; Nwakwunite, O E

2012-04-01

To compare the two methods of rapid diagnostic tests (RDTs) and microscopy in the diagnosis of malaria. RDTs and microscopy were carried out to diagnose malaria. Percentage malaria parasitaemia was calculated on thin films and all non-acute cases of plasmodiasis with less than 0.001% malaria parasitaemia were regarded as negative. Results were simply presented as percentage positive of the total number of patients under study. The results of RDTs were compared to those of microscopy while those of RDTs based on antigen were compared to those of RDTs based on antibody. Patients' follow-up was made for all cases. All the 200 patients under present study tested positive to RDTs based on malaria antibodies (serum) method (100%). 128 out of 200 tested positive to RDTs based on malaria antigen (whole blood) method (64%), while 118 out of 200 patients under present study tested positive to visual microscopy of Lieshman and diluted Giemsa (59%). All patients that tested positive to microscopy also tested positive to RDTs based on antigen. All patients on the second day of follow-up were non-febrile and had antimalaria drugs. We conclude based on the present study that the RDTs based on malaria antigen (whole blood) method is as specific as the traditional microscopy and even appears more sensitive than microscopy. The RDTs based on antibody (serum) method is unspecific thus it should not be encouraged. It is most likely that Africa being an endemic region, formation of certain levels of malaria antibody may not be uncommon. The present study also supports the opinion that a good number of febrile cases is not due to malaria. We support WHO's report on cost effectiveness of RDTs but, recommend that only the antigen based method should possibly, be adopted in Africa and other malaria endemic regions of the world.
An at-site flood estimation method in the context of nonstationarity I. A simulation study

NASA Astrophysics Data System (ADS)

Gado, Tamer A.; Nguyen, Van-Thanh-Van

2016-04-01

The stationarity of annual flood peak records is the traditional assumption of flood frequency analysis. In some cases, however, as a result of land-use and/or climate change, this assumption is no longer valid. Therefore, new statistical models are needed to capture dynamically the change of probability density functions over time, in order to obtain reliable flood estimation. In this study, an innovative method for nonstationary flood frequency analysis was presented. Here, the new method is based on detrending the flood series and applying the L-moments along with the GEV distribution to the transformed ;stationary; series (hereafter, this is called the LM-NS). The LM-NS method was assessed through a comparative study with the maximum likelihood (ML) method for the nonstationary GEV model, as well as with the stationary (S) GEV model. The comparative study, based on Monte Carlo simulations, was carried out for three nonstationary GEV models: a linear dependence of the mean on time (GEV1), a quadratic dependence of the mean on time (GEV2), and linear dependence in both the mean and log standard deviation on time (GEV11). The simulation results indicated that the LM-NS method performs better than the ML method for most of the cases studied, whereas the stationary method provides the least accurate results. An additional advantage of the LM-NS method is to avoid the numerical problems (e.g., convergence problems) that may occur with the ML method when estimating parameters for small data samples.
A comparative study of multivariable robustness analysis methods as applied to integrated flight and propulsion control

NASA Technical Reports Server (NTRS)

Schierman, John D.; Lovell, T. A.; Schmidt, David K.

1993-01-01

Three multivariable robustness analysis methods are compared and contrasted. The focus of the analysis is on system stability and performance robustness to uncertainty in the coupling dynamics between two interacting subsystems. Of particular interest is interacting airframe and engine subsystems, and an example airframe/engine vehicle configuration is utilized in the demonstration of these approaches. The singular value (SV) and structured singular value (SSV) analysis methods are compared to a method especially well suited for analysis of robustness to uncertainties in subsystem interactions. This approach is referred to here as the interacting subsystem (IS) analysis method. This method has been used previously to analyze airframe/engine systems, emphasizing the study of stability robustness. However, performance robustness is also investigated here, and a new measure of allowable uncertainty for acceptable performance robustness is introduced. The IS methodology does not require plant uncertainty models to measure the robustness of the system, and is shown to yield valuable information regarding the effects of subsystem interactions. In contrast, the SV and SSV methods allow for the evaluation of the robustness of the system to particular models of uncertainty, and do not directly indicate how the airframe (engine) subsystem interacts with the engine (airframe) subsystem.
Evaluation of Lysis Methods for the Extraction of Bacterial DNA for Analysis of the Vaginal Microbiota.

PubMed

Gill, Christina; van de Wijgert, Janneke H H M; Blow, Frances; Darby, Alistair C

2016-01-01

Recent studies on the vaginal microbiota have employed molecular techniques such as 16S rRNA gene sequencing to describe the bacterial community as a whole. These techniques require the lysis of bacterial cells to release DNA before purification and PCR amplification of the 16S rRNA gene. Currently, methods for the lysis of bacterial cells are not standardised and there is potential for introducing bias into the results if some bacterial species are lysed less efficiently than others. This study aimed to compare the results of vaginal microbiota profiling using four different pretreatment methods for the lysis of bacterial samples (30 min of lysis with lysozyme, 16 hours of lysis with lysozyme, 60 min of lysis with a mixture of lysozyme, mutanolysin and lysostaphin and 30 min of lysis with lysozyme followed by bead beating) prior to chemical and enzyme-based DNA extraction with a commercial kit. After extraction, DNA yield did not significantly differ between methods with the exception of lysis with lysozyme combined with bead beating which produced significantly lower yields when compared to lysis with the enzyme cocktail or 30 min lysis with lysozyme only. However, this did not result in a statistically significant difference in the observed alpha diversity of samples. The beta diversity (Bray-Curtis dissimilarity) between different lysis methods was statistically significantly different, but this difference was small compared to differences between samples, and did not affect the grouping of samples with similar vaginal bacterial community structure by hierarchical clustering. An understanding of how laboratory methods affect the results of microbiota studies is vital in order to accurately interpret the results and make valid comparisons between studies. Our results indicate that the choice of lysis method does not prevent the detection of effects relating to the type of vaginal bacterial community one of the main outcome measures of epidemiological studies. However, we recommend that the same method is used on all samples within a particular study.
Comparison of Manual Refraction Versus Autorefraction in 60 Diabetic Retinopathy Patients

PubMed Central

Shirzadi, Keyvan; Shahraki, Kourosh; Yahaghi, Emad; Makateb, Ali; Khosravifard, Keivan

2016-01-01

Aim: The purpose of the study was to evaluate the comparison of manual refraction versus autorefraction in diabetic retinopathy patients. Material and Methods: The study was conducted at the Be’sat Army Hospital from 2013-2015. In the present study differences between two common refractometry methods (manual refractometry and Auto refractometry) in diagnosis and follow up of retinopathy in patients affected with diabetes is investigated. Results: Our results showed that there is a significant difference in visual acuity score of patients between manual and auto refractometry. Despite this fact, spherical equivalent scores of two methods of refractometry did not show a significant statistical difference in the patients. Conclusion: Although use of manual refraction is comparable with autorefraction in evaluating spherical equivalent scores in diabetic patients affected with retinopathy, but in the case of visual acuity results from these two methods are not comparable. PMID:27703289
Dosimetry and microdosimetry using COTS ICs: A comparative study

NASA Technical Reports Server (NTRS)

Scheick, L.; Swift, G.; Guertin, S.; Roth, D.; McNulty, P.; Nguyen, D.

2002-01-01

A new method using an array of MOS transistors formeasuring dose absorbed from ionizing radiation is compared to previous dosimetric methods., The accuracy and precision of dosimetry based on COTS SRAMs, DRAMs, and WPROMs are compared and contrasted. Applications of these devices in various space missions will be discussed. TID results are presented for this summary and microdosimetricresults will be added to the full paper. Finally, an analysis of the optimal condition for a digital dosimeter will be presented.
A comparative study on different methods of automatic mesh generation of human femurs.

PubMed

Viceconti, M; Bellingeri, L; Cristofolini, L; Toni, A

1998-01-01

The aim of this study was to evaluate comparatively five methods for automating mesh generation (AMG) when used to mesh a human femur. The five AMG methods considered were: mapped mesh, which provides hexahedral elements through a direct mapping of the element onto the geometry; tetra mesh, which generates tetrahedral elements from a solid model of the object geometry; voxel mesh which builds cubic 8-node elements directly from CT images; and hexa mesh that automatically generated hexahedral elements from a surface definition of the femur geometry. The various methods were tested against two reference models: a simplified geometric model and a proximal femur model. The first model was useful to assess the inherent accuracy of the meshes created by the AMG methods, since an analytical solution was available for the elastic problem of the simplified geometric model. The femur model was used to test the AMG methods in a more realistic condition. The femoral geometry was derived from a reference model (the "standardized femur") and the finite element analyses predictions were compared to experimental measurements. All methods were evaluated in terms of human and computer effort needed to carry out the complete analysis, and in terms of accuracy. The comparison demonstrated that each tested method deserves attention and may be the best for specific situations. The mapped AMG method requires a significant human effort but is very accurate and it allows a tight control of the mesh structure. The tetra AMG method requires a solid model of the object to be analysed but is widely available and accurate. The hexa AMG method requires a significant computer effort but can also be used on polygonal models and is very accurate. The voxel AMG method requires a huge number of elements to reach an accuracy comparable to that of the other methods, but it does not require any pre-processing of the CT dataset to extract the geometry and in some cases may be the only viable solution.
Prospective cohort studies of newly marketed medications: using covariate data to inform the design of large-scale studies.

PubMed

Franklin, Jessica M; Rassen, Jeremy A; Bartels, Dorothee B; Schneeweiss, Sebastian

2014-01-01

Nonrandomized safety and effectiveness studies are often initiated immediately after the approval of a new medication, but patients prescribed the new medication during this period may be substantially different from those receiving an existing comparator treatment. Restricting the study to comparable patients after data have been collected is inefficient in prospective studies with primary collection of outcomes. We discuss design and methods for evaluating covariate data to assess the comparability of treatment groups, identify patient subgroups that are not comparable, and decide when to transition to a large-scale comparative study. We demonstrate methods in an example study comparing Cox-2 inhibitors during their postmarketing period (1999-2005) with nonselective nonsteroidal anti-inflammatory drugs (NSAIDs). Graphical checks of propensity score distributions in each treatment group showed substantial problems with overlap in the initial cohorts. In the first half of 1999, >40% of patients were in the region of nonoverlap on the propensity score, and across the study period this fraction never dropped below 10% (the a priori decision threshold for transitioning to the large-scale study). After restricting to patients with no prior NSAID use, <1% of patients were in the region of nonoverlap, indicating that a large-scale study could be initiated in this subgroup and few patients would need to be trimmed from analysis. A sequential study design that uses pilot data to evaluate treatment selection can guide the efficient design of large-scale outcome studies with primary data collection by focusing on comparable patients.
A CTSA Agenda to Advance Methods for Comparative Effectiveness Research

PubMed Central

Helfand, Mark; Tunis, Sean; Whitlock, Evelyn P.; Pauker, Stephen G.; Basu, Anirban; Chilingerian, Jon; Harrell Jr., Frank E.; Meltzer, David O.; Montori, Victor M.; Shepard, Donald S.; Kent, David M.

2011-01-01

Abstract Clinical research needs to be more useful to patients, clinicians, and other decision makers. To meet this need, more research should focus on patient‐centered outcomes, compare viable alternatives, and be responsive to individual patients’ preferences, needs, pathobiology, settings, and values. These features, which make comparative effectiveness research (CER) fundamentally patient‐centered, challenge researchers to adopt or develop methods that improve the timeliness, relevance, and practical application of clinical studies. In this paper, we describe 10 priority areas that address 3 critical needs for research on patient‐centered outcomes (PCOR): (1) developing and testing trustworthy methods to identify and prioritize important questions for research; (2) improving the design, conduct, and analysis of clinical research studies; and (3) linking the process and outcomes of actual practice to priorities for research on patient‐centered outcomes. We argue that the National Institutes of Health, through its clinical and translational research program, should accelerate the development and refinement of methods for CER by linking a program of methods research to the broader portfolio of large, prospective clinical and health system studies it supports. Insights generated by this work should be of enormous value to PCORI and to the broad range of organizations that will be funding and implementing CER. Clin Trans Sci 2011; Volume 4: 188–198 PMID:21707950
Comparing the Effectiveness of Self-Paced and Collaborative Frame-of-Reference Training on Rater Accuracy in a Large-Scale Writing Assessment

ERIC Educational Resources Information Center

Raczynski, Kevin R.; Cohen, Allan S.; Engelhard, George, Jr.; Lu, Zhenqiu

2015-01-01

There is a large body of research on the effectiveness of rater training methods in the industrial and organizational psychology literature. Less has been reported in the measurement literature on large-scale writing assessments. This study compared the effectiveness of two widely used rater training methods--self-paced and collaborative…
A Method of Assembling Cross-Sectional Indicators into a Community Quality of Life

ERIC Educational Resources Information Center

Epley, Donald R.; Menon, Mohan

2008-01-01

This study develops a new method of measuring quality of life at the local and state level. Further, it presents a methodology that combines heterogeneous indicators from different fields, such as economics, social, and health, into one total measurement. The technique shown can be used to compare one region with another, or compare one metro area…
The Relationship of Instructional Methods with Student Responses to the Survey of Attitudes Toward Statistics.

ERIC Educational Resources Information Center

Faghihi, Foroozandeh; Rakow, Ernest A.

This study, conducted at the University of Memphis (Tennessee), compared the effects of a self-paced method of instruction on the attitudes and perceptions of students enrolled in an undergraduate statistics course with those of a comparable group of students taking statistics in a traditional lecture setting. The non-traditional course used a…
Towards Extending Forward Kinematic Models on Hyper-Redundant Manipulator to Cooperative Bionic Arms

NASA Astrophysics Data System (ADS)

Singh, Inderjeet; Lakhal, Othman; Merzouki, Rochdi

2017-01-01

Forward Kinematics is a stepping stone towards finding an inverse solution and subsequently a dynamic model of a robot. Hence a study and comparison of various Forward Kinematic Models (FKMs) is necessary for robot design. This paper deals with comparison of three FKMs on the same hyper-redundant Compact Bionic Handling Assistant (CBHA) manipulator under same conditions. The aim of this study is to project on modeling cooperative bionic manipulators. Two of these methods are quantitative methods, Arc Geometry HTM (Homogeneous Transformation Matrix) Method and Dual Quaternion Method, while the other one is Hybrid Method which uses both quantitative as well as qualitative approach. The methods are compared theoretically and experimental results are discussed to add further insight to the comparison. HTM is the widely used and accepted technique, is taken as reference and trajectory deviation in other techniques are compared with respect to HTM. Which method allows obtaining an accurate kinematic behavior of the CBHA, controlled in the real-time.

The impact of loss to follow-up on hypothesis tests of the treatment effect for several statistical methods in substance abuse clinical trials.

PubMed

Hedden, Sarra L; Woolson, Robert F; Carter, Rickey E; Palesch, Yuko; Upadhyaya, Himanshu P; Malcolm, Robert J

2009-07-01

"Loss to follow-up" can be substantial in substance abuse clinical trials. When extensive losses to follow-up occur, one must cautiously analyze and interpret the findings of a research study. Aims of this project were to introduce the types of missing data mechanisms and describe several methods for analyzing data with loss to follow-up. Furthermore, a simulation study compared Type I error and power of several methods when missing data amount and mechanism varies. Methods compared were the following: Last observation carried forward (LOCF), multiple imputation (MI), modified stratified summary statistics (SSS), and mixed effects models. Results demonstrated nominal Type I error for all methods; power was high for all methods except LOCF. Mixed effect model, modified SSS, and MI are generally recommended for use; however, many methods require that the data are missing at random or missing completely at random (i.e., "ignorable"). If the missing data are presumed to be nonignorable, a sensitivity analysis is recommended.
[Comparative analysis of modification of Misgav-Ladach and Pfannenstiel methods for cesarean section in the material of Fetal-Maternal Clinical Department PMMH-RI between 1994-1999].

PubMed

Pawłowicz, P; Wilczyński, J; Stachowiak, G

2000-04-01

Comparative analysis of own modification of Misgav-Ladach (mML) and Pfannenstiel methods for caesarean section in the material of Fetal-Maternal Medicine Clinical Department PMMH-RI between 1994-99. Study group consists of 242 patients. In all women from this group we performed caesarean section using Misgav-Ladach method. Among all patients from control group counting 285 women we performed caesarean section applying Pfannenstiel method. To analyse clinical postoperative course in both groups we took account several parameters. Statistical analysis revealed that most of clinical postoperative course parameters was significantly better values in the study group we performed caesarean section using Misgav-Ladach method. The benefits of Misgav-Ladach method, with less pain post-operatively and quicker recovery, are all a by-product of doing the least harm during surgery and removing every unnecessary step. This method is appealing for its simplicity, ease of execution and its time-saving advantage.
Exploring Intercultural Competence in Teacher Education: A Comparative Study between Science and Foreign Language Teacher Trainers

ERIC Educational Resources Information Center

Akpinar, Kadriye Dilek; Ünaldi, Ihsan

2014-01-01

This study investigated the intercultural outcomes of short-term study visit programs for Foreign Language and Science teacher trainers. A mixed method including quantitative and qualitative data was used to compare the differences between the two groups' intercultural development in terms of their study field. Fantini's questionnaire was used for…
A comparison of locally adaptive multigrid methods: LDC, FAC and FIC

NASA Technical Reports Server (NTRS)

Khadra, Khodor; Angot, Philippe; Caltagirone, Jean-Paul

1993-01-01

This study is devoted to a comparative analysis of three 'Adaptive ZOOM' (ZOom Overlapping Multi-level) methods based on similar concepts of hierarchical multigrid local refinement: LDC (Local Defect Correction), FAC (Fast Adaptive Composite), and FIC (Flux Interface Correction)--which we proposed recently. These methods are tested on two examples of a bidimensional elliptic problem. We compare, for V-cycle procedures, the asymptotic evolution of the global error evaluated by discrete norms, the corresponding local errors, and the convergence rates of these algorithms.
Accounting for Scale Heterogeneity in Healthcare-Related Discrete Choice Experiments when Comparing Stated Preferences: A Systematic Review.

PubMed

Wright, Stuart J; Vass, Caroline M; Sim, Gene; Burton, Michael; Fiebig, Denzil G; Payne, Katherine

2018-02-28

Scale heterogeneity, or differences in the error variance of choices, may account for a significant amount of the observed variation in the results of discrete choice experiments (DCEs) when comparing preferences between different groups of respondents. The aim of this study was to identify if, and how, scale heterogeneity has been addressed in healthcare DCEs that compare the preferences of different groups. A systematic review identified all healthcare DCEs published between 1990 and February 2016. The full-text of each DCE was then screened to identify studies that compared preferences using data generated from multiple groups. Data were extracted and tabulated on year of publication, samples compared, tests for scale heterogeneity, and analytical methods to account for scale heterogeneity. Narrative analysis was used to describe if, and how, scale heterogeneity was accounted for when preferences were compared. A total of 626 healthcare DCEs were identified. Of these 199 (32%) aimed to compare the preferences of different groups specified at the design stage, while 79 (13%) compared the preferences of groups identified at the analysis stage. Of the 278 included papers, 49 (18%) discussed potential scale issues, 18 (7%) used a formal method of analysis to account for scale between groups, and 2 (1%) accounted for scale differences between preference groups at the analysis stage. Scale heterogeneity was present in 65% (n = 13) of studies that tested for it. Analytical methods to test for scale heterogeneity included coefficient plots (n = 5, 2%), heteroscedastic conditional logit models (n = 6, 2%), Swait and Louviere tests (n = 4, 1%), generalised multinomial logit models (n = 5, 2%), and scale-adjusted latent class analysis (n = 2, 1%). Scale heterogeneity is a prevalent issue in healthcare DCEs. Despite this, few published DCEs have discussed such issues, and fewer still have used formal methods to identify and account for the impact of scale heterogeneity. The use of formal methods to test for scale heterogeneity should be used, otherwise the results of DCEs potentially risk producing biased and potentially misleading conclusions regarding preferences for aspects of healthcare.
Comparative study of Wenner and Schlumberger electrical resistivity method for groundwater investigation: a case study from Dhule district (M.S.), India

NASA Astrophysics Data System (ADS)

Vasantrao, Baride Mukund; Bhaskarrao, Patil Jitendra; Mukund, Baride Aarti; Baburao, Golekar Rushikesh; Narayan, Patil Sanjaykumar

2017-12-01

The area chosen for the present study is Dhule district, which belongs to the drought prone area of Maharashtra State, India. Dhule district suffers from water problem, and therefore, there is no extra water available to supply for the agricultural and industrial growth. To understand the lithological characters in terms of its hydro-geological conditions, it is necessary to understand the geology of the area. It is now established fact that the geophysical method gives a better information of subsurface geology. Geophysical electrical surveys with four electrodes configuration, i.e., Wenner and Schlumberger method, were carried out at the same selected sites to observe the similarity and compared both the applications in terms of its use and handling in the field. A total 54 VES soundings were carried out spread over the Dhule district and representing different lithological units. The VES curves are drawn using inverse slope method for Wenner configuration, IPI2 win Software, and curve matching techniques were used for Schlumberger configuration. Regionwise lithologs are prepared based on the obtained resistivity and thickness for Wenner method. Regionwise curves were prepared based on resistivity layers for Schlumberger method. Comparing the two methods, it is observed that Wenner and Schlumberger methods have merits or demerits. Considering merits and demerits from the field point of view, it is suggested that Wenner inverse slope method is more handy for calculation and interpretation, but requires lateral length which is a constrain. Similarly, Schlumberger method is easy in application but unwieldy for their interpretation. The work amply proves the applicability of geophysical techniques in the water resource evaluation procedure. This technique is found to be suitable for the areas with similar geological setup elsewhere.
A COMPARISON OF SIX BENTHIC MACROINVERTEBRATE SAMPLING METHODS IN FOUR LARGE RIVERS

EPA Science Inventory

In 1999, a study was conducted to compare six macroinvertebrate sampling methods in four large (boatable) rivers that drain into the Ohio River. Two methods each were adapted from existing methods used by the USEPA, USGS and Ohio EPA. Drift nets were unable to collect a suffici...
Comparison of micrometeorological techniques in measuring gas emissions from waste lagoons

USDA-ARS?s Scientific Manuscript database

In this study, we evaluated and compared the accuracies of two micrometeorological methods using open-path tunable diode laser absorption spectrometers; vertical radial plume mapping method and the inverse dispersion model method. The accuracy of these two methods was evaluated using a 45m x 45m p...
Comparison of micrometeorological techniques in measuring gas emissions from waste lagoons

USDA-ARS?s Scientific Manuscript database

In this study, we evaluated and compared the accuracies of two micrometeorological methods using open-path tunable diode laser absorption spectrometers; vertical radial plume mapping method (US EPA OTM-10) and the inverse dispersion model method. The accuracy of these two methods was evaluated usin...
Evaluation of methods for detection of fluorescence labeled subcellular objects in microscope images.

PubMed

Ruusuvuori, Pekka; Aijö, Tarmo; Chowdhury, Sharif; Garmendia-Torres, Cecilia; Selinummi, Jyrki; Birbaumer, Mirko; Dudley, Aimée M; Pelkmans, Lucas; Yli-Harja, Olli

2010-05-13

Several algorithms have been proposed for detecting fluorescently labeled subcellular objects in microscope images. Many of these algorithms have been designed for specific tasks and validated with limited image data. But despite the potential of using extensive comparisons between algorithms to provide useful information to guide method selection and thus more accurate results, relatively few studies have been performed. To better understand algorithm performance under different conditions, we have carried out a comparative study including eleven spot detection or segmentation algorithms from various application fields. We used microscope images from well plate experiments with a human osteosarcoma cell line and frames from image stacks of yeast cells in different focal planes. These experimentally derived images permit a comparison of method performance in realistic situations where the number of objects varies within image set. We also used simulated microscope images in order to compare the methods and validate them against a ground truth reference result. Our study finds major differences in the performance of different algorithms, in terms of both object counts and segmentation accuracies. These results suggest that the selection of detection algorithms for image based screens should be done carefully and take into account different conditions, such as the possibility of acquiring empty images or images with very few spots. Our inclusion of methods that have not been used before in this context broadens the set of available detection methods and compares them against the current state-of-the-art methods for subcellular particle detection.
Impact of immortal person-time and time scale in comparative effectiveness research for medical devices: a case for implantable cardioverter-defibrillators.

PubMed

Mi, Xiaojuan; Hammill, Bradley G; Curtis, Lesley H; Greiner, Melissa A; Setoguchi, Soko

2013-08-01

To assess the extent of immortal time bias in estimating the clinical effectiveness of implantable cardioverter-defibrillators (ICDs) and the impact of methods of handling immortal time bias. Retrospective population-based cohort study of patients with heart failure in a national registry linked to Medicare claims (2003-2008). We compared three methods of handling immortal time bias, namely the Mantel-Byar (or time-dependent exposure assignment), the landmark, and the exclusion methods. Of the 5,226 study patients, 1,274 (24.4%) received ICD therapy. Total person-years in the Mantel-Byar method were 2,639, or 490 more than that in the exclusion method, reflecting potential immortal time in the study. The exclusion method yielded a hazard ratio of 0.71 (95% confidence interval [CI]: 0.63-0.80), which was 16% lower than the Mantel-Byar method (0.84; 95% CI: 0.75-0.95). The 120-day landmark method yielded similar results to those produced by the Mantel-Byar method (0.82; 95% CI: 0.72-0.95). Immortal time bias was detected in the ICD clinical effectiveness study, which might have led to substantial bias overestimating the treatment effect if handled by exclusion. When an appropriate landmark was selected, that method yielded similar hazard ratios to those obtained by the Mantel-Byar method, supporting the validity of the landmark method. Copyright © 2013 Elsevier Inc. All rights reserved.
Developing pongid dentition and its use for ageing individual crania in comparative cross-sectional growth studies.

PubMed

Dean, M C; Wood, B A

1981-01-01

This study of the developing pongid dentition is based on cross-sectional radiographic data of juvenile Pan troglodytes, Gorilla gorilla, and Pongo pygmaeus skulls. Comparisons with developmental features of the human dentition are made, and possible explanations for the formation of larger teeth within the reduced pongid growth period are discussed. The data presented in this study provide an alternative method for ageing individual pongid crania in comparative cross-sectional growth studies. The advantages of this method are demonstrated by ageing individual Gorilla crania form radiographs and plotting relative dental age against length of the jaw.
Comparing concentration methods: parasitrap® versus Kato-Katz for studying the prevalence of Helminths in Bengo province, Angola.

PubMed

Mirante, Clara; Clemente, Isabel; Zambu, Graciette; Alexandre, Catarina; Ganga, Teresa; Mayer, Carlos; Brito, Miguel

2016-09-01

Helminth intestinal parasitoses are responsible for high levels of child mortality and morbidity. Hence, the capacity to diagnose these parasitoses and consequently ensure due treatment represents a factor of great importance. The main objective of this study involves comparing two methods of concentration, parasitrap and Kato-Katz, for the diagnosis of intestinal parasitoses in faecal samples. Sample processing made recourse to two different concentration methods: the commercial parasitrap® method and the Kato-Katz method. We correspondingly collected a total of 610 stool samples from pre-school and school age children. The results demonstrate the incidence of helminth parasites in 32.8% or 32.3% of the sample collected depending on whether the concentration method applied was either the parasitrap method or the Kato-Katz method. We detected a relatively high percentage of samples testing positive for two or more species of helminth parasites. We would highlight that in searching for larvae the Kato-Katz method does not prove as appropriate as the parasitrap method. Both techniques prove easily applicable even in field working conditions and returning mutually agreeing results. This study concludes in favour of the need for deworming programs and greater public awareness among the rural populations of Angola.
Development and validity of methods for the estimation of temporal gait parameters from heel-attached inertial sensors in younger and older adults.

PubMed

Misu, Shogo; Asai, Tsuyoshi; Ono, Rei; Sawa, Ryuichi; Tsutsumimoto, Kota; Ando, Hiroshi; Doi, Takehiko

2017-09-01

The heel is likely a suitable location to which inertial sensors are attached for the detection of gait events. However, there are few studies to detect gait events and determine temporal gait parameters using sensors attached to the heels. We developed two methods to determine temporal gait parameters: detecting heel-contact using acceleration and detecting toe-off using angular velocity data (acceleration-angular velocity method; A-V method), and detecting both heel-contact and toe-off using angular velocity data (angular velocity-angular velocity method; V-V method). The aim of this study was to examine the concurrent validity of the A-V and V-V methods against the standard method, and to compare their accuracy. Temporal gait parameters were measured in 10 younger and 10 older adults. The intra-class correlation coefficients were excellent in both methods compared with the standard method (0.80 to 1.00). The root mean square errors of stance and swing time in the A-V method were smaller than the V-V method in older adults, although there were no significant discrepancies in the other comparisons. Our study suggests that inertial sensors attached to the heels, using the A-V method in particular, provide a valid measurement of temporal gait parameters. Copyright © 2017 Elsevier B.V. All rights reserved.
Evaluating the Risks of Clinical Research: Direct Comparative Analysis

PubMed Central

Abdoler, Emily; Roberson-Nay, Roxann; Pine, Daniel S.; Wendler, David

2014-01-01

Abstract Objectives: Many guidelines and regulations allow children and adolescents to be enrolled in research without the prospect of clinical benefit when it poses minimal risk. However, few systematic methods exist to determine when research risks are minimal. This situation has led to significant variation in minimal risk judgments, raising concern that some children are not being adequately protected. To address this concern, we describe a new method for implementing the widely endorsed “risks of daily life” standard for minimal risk. This standard defines research risks as minimal when they do not exceed the risks posed by daily life activities or routine examinations. Methods: This study employed a conceptual and normative analysis, and use of an illustrative example. Results: Different risks are composed of the same basic elements: Type, likelihood, and magnitude of harm. Hence, one can compare the risks of research and the risks of daily life by comparing the respective basic elements with each other. We use this insight to develop a systematic method, direct comparative analysis, for implementing the “risks of daily life” standard for minimal risk. The method offers a way of evaluating research procedures that pose the same types of risk as daily life activities, such as the risk of experiencing anxiety, stress, or other psychological harm. We thus illustrate how direct comparative analysis can be applied in practice by using it to evaluate whether the anxiety induced by a respiratory CO2 challenge poses minimal or greater than minimal risks in children and adolescents. Conclusions: Direct comparative analysis is a systematic method for applying the “risks of daily life” standard for minimal risk to research procedures that pose the same types of risk as daily life activities. It thereby offers a method to protect children and adolescents in research, while ensuring that important studies are not blocked because of unwarranted concerns about research risks. PMID:25210944
Use of continuous and grab sample data for calculating total maximum daily load (TMDL) in agricultural watersheds.

PubMed

Gulati, Shelly; Stubblefield, Ashley A; Hanlon, Jeremy S; Spier, Chelsea L; Stringfellow, William T

2014-03-01

Measuring the discharge of diffuse pollution from agricultural watersheds presents unique challenges. Flows in agricultural watersheds, particularly in Mediterranean climates, can be predominately irrigation runoff and exhibit large diurnal fluctuation in both volume and concentration. Flow and pollutant concentrations in these smaller watersheds dominated by human activity do not conform to a normal distribution and it is not clear if parametric methods are appropriate or accurate for load calculations. The objective of this study was to compare the accuracy of five load estimation methods to calculate pollutant loads from agricultural watersheds. Calculation of loads using results from discrete (grab) samples was compared with the true-load computed using in situ continuous monitoring measurements. A new method is introduced that uses a non-parametric measure of central tendency (the median) to calculate loads (median-load). The median-load method was compared to more commonly used parametric estimation methods which rely on using the mean as a measure of central tendency (mean-load and daily-load), a method that utilizes the total flow volume (volume-load), and a method that uses measure of flow at the time of sampling (instantaneous-load). Using measurements from ten watersheds in the San Joaquin Valley of California, the average percent error compared to the true-load for total dissolved solids (TDS) was 7.3% for the median-load, 6.9% for the mean-load, 6.9% for the volume-load, 16.9% for the instantaneous-load, and 18.7% for the daily-load methods of calculation. The results of this study show that parametric methods are surprisingly accurate, even for data that have starkly non-normal distributions and are highly skewed. Copyright © 2013 Elsevier Ltd. All rights reserved.
A review of the application of propensity score methods yielded increasing use, advantages in specific settings, but not substantially different estimates compared with conventional multivariable methods

PubMed Central

Stürmer, Til; Joshi, Manisha; Glynn, Robert J.; Avorn, Jerry; Rothman, Kenneth J.; Schneeweiss, Sebastian

2006-01-01

Objective Propensity score analyses attempt to control for confounding in non-experimental studies by adjusting for the likelihood that a given patient is exposed. Such analyses have been proposed to address confounding by indication, but there is little empirical evidence that they achieve better control than conventional multivariate outcome modeling. Study design and methods Using PubMed and Science Citation Index, we assessed the use of propensity scores over time and critically evaluated studies published through 2003. Results Use of propensity scores increased from a total of 8 papers before 1998 to 71 in 2003. Most of the 177 published studies abstracted assessed medications (N=60) or surgical interventions (N=51), mainly in cardiology and cardiac surgery (N=90). Whether PS methods or conventional outcome models were used to control for confounding had little effect on results in those studies in which such comparison was possible. Only 9 out of 69 studies (13%) had an effect estimate that differed by more than 20% from that obtained with a conventional outcome model in all PS analyses presented. Conclusions Publication of results based on propensity score methods has increased dramatically, but there is little evidence that these methods yield substantially different estimates compared with conventional multivariable methods. PMID:16632131
The Mixed Finite Element Multigrid Method for Stokes Equations

PubMed Central

Muzhinji, K.; Shateyi, S.; Motsa, S. S.

2015-01-01

The stable finite element discretization of the Stokes problem produces a symmetric indefinite system of linear algebraic equations. A variety of iterative solvers have been proposed for such systems in an attempt to construct efficient, fast, and robust solution techniques. This paper investigates one of such iterative solvers, the geometric multigrid solver, to find the approximate solution of the indefinite systems. The main ingredient of the multigrid method is the choice of an appropriate smoothing strategy. This study considers the application of different smoothers and compares their effects in the overall performance of the multigrid solver. We study the multigrid method with the following smoothers: distributed Gauss Seidel, inexact Uzawa, preconditioned MINRES, and Braess-Sarazin type smoothers. A comparative study of the smoothers shows that the Braess-Sarazin smoothers enhance good performance of the multigrid method. We study the problem in a two-dimensional domain using stable Hood-Taylor Q 2-Q 1 pair of finite rectangular elements. We also give the main theoretical convergence results. We present the numerical results to demonstrate the efficiency and robustness of the multigrid method and confirm the theoretical results. PMID:25945361
The structure, vibrational spectra and nonlinear optical properties of the L-lysine × tartaric acid complex—Theoretical studies

NASA Astrophysics Data System (ADS)

Drozd, M.; Marchewka, M. K.

2006-05-01

The room temperature X-ray studies of L-lysine × tartaric acid complex are not unambiguous. The disorder of three atoms of carbon in L-lysine molecule is observed. These X-ray studies are ambiguous. The theoretical geometry study performed by DFT methods explain the most doubts which are connected with crystallographic measurements. The theoretical vibrational frequencies and potential energy distribution (PED) of L-lysine × tartaric acid were calculated by B3LYP method. The calculated frequencies were compared with experimental measured IR spectra. The complete assignment of the bands has been made on the basis of the calculated PED. The restricted Hartee-Fock (RHF) methods were used for calculation of the hyperpolarizability for investigated compound. The theoretical results are compared with experimental value of β.
The Comparability of Focus Group and Survey Results: Three Case Studies.

ERIC Educational Resources Information Center

Ward, Victoria M.; And Others

1991-01-01

Focus group findings were compared with survey findings for three studies in which both methods were used. Studies conducted on voluntary sterilization in Guatemala, Honduras, and Zaire with over 2,000 subjects confirm that focus groups yield information similar to that obtained from surveys and are useful in program planning. (SLD)

Successful Developmental Math Students in Traditional Format and Online Delivery: A Comparative Study

ERIC Educational Resources Information Center

Thomas, Jeremy Lloyd

2016-01-01

The purpose of this study was to compare student performance in online and traditional classroom based developmental math courses at Texas community colleges. This study specifically examined: (a) student performance in both delivery methods, (b) students who successfully completed the developmental math course, and (c) student performance in the…
Ethinylestradiol and levonorgestrel preparations on the Belgian market: a comparative study.

PubMed

Vanheusden, V; De Braekeleer, K; Corthout, J

2012-03-01

Preparations formulated as coated or film-coated tablets, containing levonorgestrel and the combination ethinylestradiol/levonorgestrel, were evaluated in a comparative study. This study comprised in vitro dissolution, assay and content uniformity. The analytical methods were previously validated according to international guidelines. All examined products complied with the postulated requirements.
Comparative Study on the Senior Secondary School Mathematics Curricula Development in Ethiopia and Australia

ERIC Educational Resources Information Center

Meleta, Fufa E.; Zhang, Weizhong

2017-01-01

The main objective of this study is to compare the process of the senior secondary school mathematics curricula development in Ethiopia and Australia. The study was investigated qualitatively with document analysis and semi-structured interview research methods. The documents were collected from Federal Democratic Republic of Ethiopia Ministry of…
A Quantitative Comparative Study Measuring Consumer Satisfaction Based on Health Record Format

ERIC Educational Resources Information Center

Moore, Vivianne E.

2013-01-01

This research study used a quantitative comparative method to investigate the relationship between consumer satisfaction and communication based on the format of health record. The central problem investigated in this research study related to the format of health record used and consumer satisfaction with care provided and effect on communication…
The impact of cognitive remediation on cerebral activity in schizophrenia: Systematic review of the literature.

PubMed

Bon, Laura; Franck, Nicolas

2018-03-01

cognitive remediation involves either intensive training of impaired functions or implementing strategies to compensate for these impairments. In cases of schizophrenia, both methods have demonstrated benefits in terms of behavior and cerebral activity. However, despite the major differences between these two approaches, their impact has not yet been compared. We searched the PsychInfo, Pubmed, and ScienceDirect databases using the key words "cognitive remediation," "schizophrenia," "cerebral activity," and "magnetic resonance imaging," in order to select studies investigating the effects of cognitive remediation on patients with schizophrenia. The studies selected had to present their approach in detail and measure its impact in terms of both cerebral activity and cognitive function, both before and after therapy. We divided the studies into two groups, those using the strategy method and those using the training method. Eight studies were included in the review, four for the strategy method (88 patients, 44 of whom underwent remediation) and 4 for the training method (87 patients, 43 of whom underwent remediation). The analysis of the results of this study indicates that the training method is capable of activating more the targeted brain areas than the strategy method. However, the latter appears to encourage more extensive activation of the cerebral networks. The studies used for this review vary widely in terms of the imaging methods and protocol. However, differences were found between the two methods and lead us to suggest that further studies, with proper bias control, should be conducted to systematically compare the two approaches.
Prospective and Retrospective Studies of Substance Abuse Treatment Outcomes: Methods and Results of Four Large-Scale Follow-Up Studies.

ERIC Educational Resources Information Center

Gerstein, Dean R.; Johnson, Robert A.

This report compares the research methods, provider and patient characteristics, and outcome results from four large-scale followup studies of drug treatment during the 1990s: (1) the California Drug and Alcohol Treatment Assessment (CALDATA); (2) Services Research Outcomes Study (SROS); (3) National Treatment Improvement Evaluation Study (NTIES);…
Studies of mobile dust in scrape-off layer plasmas using silica aerogel collectors

NASA Astrophysics Data System (ADS)

Bergsåker, H.; Ratynskaia, S.; Litnovsky, A.; Ogata, D.; Sahle, W.

2011-08-01

Dust capture with ultralow density silica aerogel collectors is a new method, which allows time resolved in situ capture of dust particles in the scrape-off layers of fusion devices, without substantially damaging the particles. Particle composition and morphology, particle flux densities and particle velocity distributions can be determined through appropriate analysis of the aerogel surfaces after exposure. The method has been applied in comparative studies of intrinsic dust in the TEXTOR tokamak and in the Extrap T2R reversed field pinch. The analysis methods have been mainly optical microscopy and SEM. The method is shown to be applicable in both devices and the results are tentatively compared between the two plasma devices, which are very different in terms of edge plasma conditions, time scale, geometry and wall materials.
Comparison of ambulatory blood pressure reference standards in children evaluated for hypertension

PubMed Central

Jones, Deborah P.; Richey, Phyllis A.; Alpert, Bruce S.

2009-01-01

Objective The purpose of this study was to systematically compare methods for standardization of blood pressure levels obtained by ambulatory blood pressure monitoring (ABPM) in a group of 111 children studied at our institution. Methods Blood pressure indices, blood pressure loads and standard deviation scores were calculated using he original ABPM and the modified reference standards. Bland—Altman plots and kappa statistics for the level of agreement were generated. Results Overall, the agreement between the two methods was excellent; however, approximately 5% of children were classified differently by one as compared with the other method. Conclusion Depending on which version of the German Working Group’s reference standards is used for interpretation of ABPM data, the classification of the individual as having hypertension or normal blood pressure may vary. PMID:19433980
A simplified and efficient method for the analysis of fatty acid methyl esters suitable for large clinical studies.

PubMed

Masood, Athar; Stark, Ken D; Salem, Norman

2005-10-01

Conventional sample preparation for fatty acid analysis is a complicated, multiple-step process, and gas chromatography (GC) analysis alone can require >1 h per sample to resolve fatty acid methyl esters (FAMEs). Fast GC analysis was adapted to human plasma FAME analysis using a modified polyethylene glycol column with smaller internal diameters, thinner stationary phase films, increased carrier gas linear velocity, and faster temperature ramping. Our results indicated that fast GC analyses were comparable to conventional GC in peak resolution. A conventional transesterification method based on Lepage and Roy was simplified to a one-step method with the elimination of the neutralization and centrifugation steps. A robotics-amenable method was also developed, with lower methylation temperatures and in an open-tube format using multiple reagent additions. The simplified methods produced results that were quantitatively similar and with similar coefficients of variation as compared with the original Lepage and Roy method. The present streamlined methodology is suitable for the direct fatty acid analysis of human plasma, is appropriate for research studies, and will facilitate large clinical trials and make possible population studies.
Comparing four methods to estimate usual intake distributions.

PubMed

Souverein, O W; Dekkers, A L; Geelen, A; Haubrock, J; de Vries, J H; Ocké, M C; Harttig, U; Boeing, H; van 't Veer, P

2011-07-01

The aim of this paper was to compare methods to estimate usual intake distributions of nutrients and foods. As 'true' usual intake distributions are not known in practice, the comparison was carried out through a simulation study, as well as empirically, by application to data from the European Food Consumption Validation (EFCOVAL) Study in which two 24-h dietary recalls (24-HDRs) and food frequency data were collected. The methods being compared were the Iowa State University Method (ISU), National Cancer Institute Method (NCI), Multiple Source Method (MSM) and Statistical Program for Age-adjusted Dietary Assessment (SPADE). Simulation data were constructed with varying numbers of subjects (n), different values for the Box-Cox transformation parameter (λ(BC)) and different values for the ratio of the within- and between-person variance (r(var)). All data were analyzed with the four different methods and the estimated usual mean intake and selected percentiles were obtained. Moreover, the 2-day within-person mean was estimated as an additional 'method'. These five methods were compared in terms of the mean bias, which was calculated as the mean of the differences between the estimated value and the known true value. The application of data from the EFCOVAL Project included calculations of nutrients (that is, protein, potassium, protein density) and foods (that is, vegetables, fruit and fish). Overall, the mean bias of the ISU, NCI, MSM and SPADE Methods was small. However, for all methods, the mean bias and the variation of the bias increased with smaller sample size, higher variance ratios and with more pronounced departures from normality. Serious mean bias (especially in the 95th percentile) was seen using the NCI Method when r(var) = 9, λ(BC) = 0 and n = 1000. The ISU Method and MSM showed a somewhat higher s.d. of the bias compared with NCI and SPADE Methods, indicating a larger method uncertainty. Furthermore, whereas the ISU, NCI and SPADE Methods produced unimodal density functions by definition, MSM produced distributions with 'peaks', when sample size was small, because of the fact that the population's usual intake distribution was based on estimated individual usual intakes. The application to the EFCOVAL data showed that all estimates of the percentiles and mean were within 5% of each other for the three nutrients analyzed. For vegetables, fruit and fish, the differences were larger than that for nutrients, but overall the sample mean was estimated reasonably. The four methods that were compared seem to provide good estimates of the usual intake distribution of nutrients. Nevertheless, care needs to be taken when a nutrient has a high within-person variation or has a highly skewed distribution, and when the sample size is small. As the methods offer different features, practical reasons may exist to prefer one method over the other.
Comparison of Computed Tomography and Chest Radiography in the Detection of Rib Fractures in Abused Infants

ERIC Educational Resources Information Center

Wootton-Gorges, Sandra L.; Stein-Wexler, Rebecca; Walton, John W.; Rosas, Angela J.; Coulter, Kevin P.; Rogers, Kristen K.

2008-01-01

Purpose: Chest radiographs (CXR) are the standard method for evaluating rib fractures in abused infants. Computed tomography (CT) is a sensitive method to detect rib fractures. The purpose of this study was to compare CT and CXR in the evaluation of rib fractures in abused infants. Methods: This retrospective study included all 12 abused infants…
Identification of Child Maltreatment Using Prospective and Self-Report Methodologies: A Comparison of Maltreatment Incidence and Relation to Later Psychopathology

ERIC Educational Resources Information Center

Shaffer, Anne; Huston, Lisa; Egeland, Byron

2008-01-01

Objectives: One of the greatest methodological problems in the study of childhood maltreatment is the discrepancy in methods by which cases of child maltreatment are identified. The current study compared incidents of maltreatment identified prospectively, retrospectively, or through a combination of both methods. Method: Within a cohort of 170…
The Rivalry between Simulation and Problem-Based Learning: A Study of Learning Transfer in Physician Assistant Students

ERIC Educational Resources Information Center

Meyer, Kimberly E.

2010-01-01

The purpose of this dissertation was to evaluate learning transfer achieved by physician assistant students comparing two instructional methods, human patient simulation and electronic clinical case studies. This prospective, randomized, mixed-methods study utilized first and second-year physician assistant student volunteers taking a pretest and…
Studying the Impact of Three Different Instructional Methods on Preservice Teachers' Decision-Making

ERIC Educational Resources Information Center

Cevik, Yasemin Demiraslan; Andre, Thomas

2014-01-01

This study compared the impact of three types of instructional methods (case-based learning, worked example and faded worked example) on preservice teachers' (n?=?72) decision-making about classroom management. A quasi-experimental study was conducted to investigate both the outcomes and the processes of preservice teachers' decision-making…
[An in vitro method for studying the metabolism of young bone matrix].

PubMed

Bonneton, C; Guest, M; Delbarre, F

1977-07-04

A method for studying in vitro bone resorption by the use of 35S labeled injection was investigated. Various substances (papaine) and hormones (calcitonin, vitamin D analogues) were tested and their effects on 35S and 45Ca metabolism were compared.
Tree leaves extraction in natural images: comparative study of preprocessing tools and segmentation methods.

PubMed

Grand-Brochier, Manuel; Vacavant, Antoine; Cerutti, Guillaume; Kurtz, Camille; Weber, Jonathan; Tougne, Laure

2015-05-01

In this paper, we propose a comparative study of various segmentation methods applied to the extraction of tree leaves from natural images. This study follows the design of a mobile application, developed by Cerutti et al. (published in ReVeS Participation--Tree Species Classification Using Random Forests and Botanical Features. CLEF 2012), to highlight the impact of the choices made for segmentation aspects. All the tests are based on a database of 232 images of tree leaves depicted on natural background from smartphones acquisitions. We also propose to study the improvements, in terms of performance, using preprocessing tools, such as the interaction between the user and the application through an input stroke, as well as the use of color distance maps. The results presented in this paper shows that the method developed by Cerutti et al. (denoted Guided Active Contour), obtains the best score for almost all observation criteria. Finally, we detail our online benchmark composed of 14 unsupervised methods and 6 supervised ones.
Comparing and improving reconstruction methods for proxies based on compositional data

NASA Astrophysics Data System (ADS)

Nolan, C.; Tipton, J.; Booth, R.; Jackson, S. T.; Hooten, M.

2017-12-01

Many types of studies in paleoclimatology and paleoecology involve compositional data. Often, these studies aim to use compositional data to reconstruct an environmental variable of interest; the reconstruction is usually done via the development of a transfer function. Transfer functions have been developed using many different methods. Existing methods tend to relate the compositional data and the reconstruction target in very simple ways. Additionally, the results from different methods are rarely compared. Here we seek to address these two issues. First, we introduce a new hierarchical Bayesian multivariate gaussian process model; this model allows for the relationship between each species in the compositional dataset and the environmental variable to be modeled in a way that captures the underlying complexities. Then, we compare this new method to machine learning techniques and commonly used existing methods. The comparisons are based on reconstructing the water table depth history of Caribou Bog (an ombrotrophic Sphagnum peat bog in Old Town, Maine, USA) from a new 7500 year long record of testate amoebae assemblages. The resulting reconstructions from different methods diverge in both their resulting means and uncertainties. In particular, uncertainty tends to be drastically underestimated by some common methods. These results will help to improve inference of water table depth from testate amoebae. Furthermore, this approach can be applied to test and improve inferences of past environmental conditions from a broad array of paleo-proxies based on compositional data
Compiled visualization with IPI method for analysing of liquid liquid mixing process

NASA Astrophysics Data System (ADS)

Jasikova, Darina; Kotek, Michal; Kysela, Bohus; Sulc, Radek; Kopecky, Vaclav

2018-06-01

The article deals with the research of mixing process using visualization techniques and IPI method. Characteristics of the size distribution and the evolution of two liquid-liquid phase's disintegration were studied. A methodology has been proposed for visualization and image analysis of data acquired during the initial phase of the mixing process. IPI method was used for subsequent detailed study of the disintegrated droplets. The article describes advantages of usage of appropriate method, presents the limits of each method, and compares them.
The Effect of the Math Emporium Instructional Method on Students' Performance in College Algebra

ERIC Educational Resources Information Center

Cousins-Cooper, Kathy; Staley, Katrina N.; Kim, Seongtae; Luke, Nicholas S.

2017-01-01

This study aims to investigate the effectiveness of the Emporium instructional method in a course of college algebra and trigonometry by comparing to the traditional lecture method. The math emporium method is a nontraditional instructional method of learning math that has been implemented at several universities with much success and has been…
Friends in the Classroom: A Comparison between Two Methods for the Assessment of Students' Friendship Networks

ERIC Educational Resources Information Center

Pijl, Sip Jan; Koster, Marloes; Hannink, Anne; Stratingh, Anna

2011-01-01

One of the methods used most often to assess students' friendships and friendship networks is the reciprocal nomination method. However, an often heard complaint is that this technique produces rather negative outcomes. This study compares the reciprocal nomination method with another method to assess students' friendships and friendship networks:…

Docking and multivariate methods to explore HIV-1 drug-resistance: a comparative analysis

NASA Astrophysics Data System (ADS)

Almerico, Anna Maria; Tutone, Marco; Lauria, Antonino

2008-05-01

In this paper we describe a comparative analysis between multivariate and docking methods in the study of the drug resistance to the reverse transcriptase and the protease inhibitors. In our early papers we developed a simple but efficient method to evaluate the features of compounds that are less likely to trigger resistance or are effective against mutant HIV strains, using the multivariate statistical procedures PCA and DA. In the attempt to create a more solid background for the prediction of susceptibility or resistance, we carried out a comparative analysis between our previous multivariate approach and molecular docking study. The intent of this paper is not only to find further support to the results obtained by the combined use of PCA and DA, but also to evidence the structural features, in terms of molecular descriptors, similarity, and energetic contributions, derived from docking, which can account for the arising of drug-resistance against mutant strains.
Comparative analysis of methods for detecting interacting loci

PubMed Central

2011-01-01

Background Interactions among genetic loci are believed to play an important role in disease risk. While many methods have been proposed for detecting such interactions, their relative performance remains largely unclear, mainly because different data sources, detection performance criteria, and experimental protocols were used in the papers introducing these methods and in subsequent studies. Moreover, there have been very few studies strictly focused on comparison of existing methods. Given the importance of detecting gene-gene and gene-environment interactions, a rigorous, comprehensive comparison of performance and limitations of available interaction detection methods is warranted. Results We report a comparison of eight representative methods, of which seven were specifically designed to detect interactions among single nucleotide polymorphisms (SNPs), with the last a popular main-effect testing method used as a baseline for performance evaluation. The selected methods, multifactor dimensionality reduction (MDR), full interaction model (FIM), information gain (IG), Bayesian epistasis association mapping (BEAM), SNP harvester (SH), maximum entropy conditional probability modeling (MECPM), logistic regression with an interaction term (LRIT), and logistic regression (LR) were compared on a large number of simulated data sets, each, consistent with complex disease models, embedding multiple sets of interacting SNPs, under different interaction models. The assessment criteria included several relevant detection power measures, family-wise type I error rate, and computational complexity. There are several important results from this study. First, while some SNPs in interactions with strong effects are successfully detected, most of the methods miss many interacting SNPs at an acceptable rate of false positives. In this study, the best-performing method was MECPM. Second, the statistical significance assessment criteria, used by some of the methods to control the type I error rate, are quite conservative, thereby limiting their power and making it difficult to fairly compare them. Third, as expected, power varies for different models and as a function of penetrance, minor allele frequency, linkage disequilibrium and marginal effects. Fourth, the analytical relationships between power and these factors are derived, aiding in the interpretation of the study results. Fifth, for these methods the magnitude of the main effect influences the power of the tests. Sixth, most methods can detect some ground-truth SNPs but have modest power to detect the whole set of interacting SNPs. Conclusion This comparison study provides new insights into the strengths and limitations of current methods for detecting interacting loci. This study, along with freely available simulation tools we provide, should help support development of improved methods. The simulation tools are available at: http://code.google.com/p/simulation-tool-bmc-ms9169818735220977/downloads/list. PMID:21729295
Comparative analysis of methods for detecting interacting loci.

PubMed

Chen, Li; Yu, Guoqiang; Langefeld, Carl D; Miller, David J; Guy, Richard T; Raghuram, Jayaram; Yuan, Xiguo; Herrington, David M; Wang, Yue

2011-07-05

Interactions among genetic loci are believed to play an important role in disease risk. While many methods have been proposed for detecting such interactions, their relative performance remains largely unclear, mainly because different data sources, detection performance criteria, and experimental protocols were used in the papers introducing these methods and in subsequent studies. Moreover, there have been very few studies strictly focused on comparison of existing methods. Given the importance of detecting gene-gene and gene-environment interactions, a rigorous, comprehensive comparison of performance and limitations of available interaction detection methods is warranted. We report a comparison of eight representative methods, of which seven were specifically designed to detect interactions among single nucleotide polymorphisms (SNPs), with the last a popular main-effect testing method used as a baseline for performance evaluation. The selected methods, multifactor dimensionality reduction (MDR), full interaction model (FIM), information gain (IG), Bayesian epistasis association mapping (BEAM), SNP harvester (SH), maximum entropy conditional probability modeling (MECPM), logistic regression with an interaction term (LRIT), and logistic regression (LR) were compared on a large number of simulated data sets, each, consistent with complex disease models, embedding multiple sets of interacting SNPs, under different interaction models. The assessment criteria included several relevant detection power measures, family-wise type I error rate, and computational complexity. There are several important results from this study. First, while some SNPs in interactions with strong effects are successfully detected, most of the methods miss many interacting SNPs at an acceptable rate of false positives. In this study, the best-performing method was MECPM. Second, the statistical significance assessment criteria, used by some of the methods to control the type I error rate, are quite conservative, thereby limiting their power and making it difficult to fairly compare them. Third, as expected, power varies for different models and as a function of penetrance, minor allele frequency, linkage disequilibrium and marginal effects. Fourth, the analytical relationships between power and these factors are derived, aiding in the interpretation of the study results. Fifth, for these methods the magnitude of the main effect influences the power of the tests. Sixth, most methods can detect some ground-truth SNPs but have modest power to detect the whole set of interacting SNPs. This comparison study provides new insights into the strengths and limitations of current methods for detecting interacting loci. This study, along with freely available simulation tools we provide, should help support development of improved methods. The simulation tools are available at: http://code.google.com/p/simulation-tool-bmc-ms9169818735220977/downloads/list.
Assessing treatment effects in older breast cancer patients: systematic review of observational research methods.

PubMed

de Glas, N A; Kiderlen, M; de Craen, A J M; Hamaker, M E; Portielje, J E A; van de Velde, C J H; Liefers, G J; Bastiaannet, E

2015-03-01

Solid evidence of treatment effects in older women with breast cancer is lacking, as they are generally underrepresented in randomized clinical trials on which guideline recommendations are based. An alternative way to study treatment effects in older patients could be to use data from observational studies. However, using appropriate methods in analyzing observational data is a key condition in order to draw valid conclusions, as directly comparing treatments generally results in biased estimates due to confounding by indication. The aim of this systematic review was to investigate the methods that have been used in observational studies that assessed the effects of breast cancer treatment on survival, breast cancer survival and recurrence in older patients (aged 65 years and older). Studies were identified through systematic review of the literature published between January 1st 2009 and December 13th 2013 in the PubMed database and EMBASe. Finally, 31 studies fulfilled the inclusion criteria. Of these, 22 studies directly compared two treatments. Fifteen out of these 22 studies addressed the problem of confounding by indication, while seven studies did not. Nine studies used some form of instrumental variable analysis. In conclusion, the vast majority of observational studies that investigate treatment effects in older breast cancer patients compared treatments directly. These studies are therefore likely to be biased. Observational research will be essential to improve treatment and outcome of older breast cancer patients, but the use of accurate methods is essential to draw valid conclusions from this type of data. Copyright © 2015 Elsevier Ltd. All rights reserved.
Estimating Body Composition in Adolescent Sprint Athletes: Comparison of Different Methods in a 3 Years Longitudinal Design

PubMed Central

Aerenhouts, Dirk

2015-01-01

A recommended field method to assess body composition in adolescent sprint athletes is currently lacking. Existing methods developed for non-athletic adolescents were not longitudinally validated and do not take maturation status into account. This longitudinal study compared two field methods, i.e., a Bio Impedance Analysis (BIA) and a skinfold based equation, with underwater densitometry to track body fat percentage relative to years from age at peak height velocity in adolescent sprint athletes. In this study, adolescent sprint athletes (34 girls, 35 boys) were measured every 6 months during 3 years (age at start = 14.8 ± 1.5yrs in girls and 14.7 ± 1.9yrs in boys). Body fat percentage was estimated in 3 different ways: 1) using BIA with the TANITA TBF 410; 2) using a skinfold based equation; 3) using underwater densitometry which was considered as the reference method. Height for age since birth was used to estimate age at peak height velocity. Cross-sectional analyses were performed using repeated measures ANOVA and Pearson correlations between measurement methods at each occasion. Data were analyzed longitudinally using a multilevel cross-classified model with the PROC Mixed procedure. In boys, compared to underwater densitometry, the skinfold based formula revealed comparable values for body fatness during the study period whereas BIA showed a different pattern leading to an overestimation of body fatness starting from 4 years after age at peak height velocity. In girls, both the skinfold based formula and BIA overestimated body fatness across the whole range of years from peak height velocity. The skinfold based method appears to give an acceptable estimation of body composition during growth as compared to underwater densitometry in male adolescent sprinters. In girls, caution is warranted when interpreting estimations of body fatness by both BIA and a skinfold based formula since both methods tend to give an overestimation. PMID:26317426
Accelerated, microwave-assisted, and conventional solvent extraction methods affect anthocyanin composition from colored grains.

PubMed

Abdel-Aal, El-Sayed M; Akhtar, Humayoun; Rabalski, Iwona; Bryan, Michael

2014-02-01

Anthocyanins are important dietary components with diverse positive functions in human health. This study investigates effects of accelerated solvent extraction (ASE) and microwave-assisted extraction (MAE) on anthocyanin composition and extraction efficiency from blue wheat, purple corn, and black rice in comparison with the commonly used solvent extraction (CSE). Factorial experimental design was employed to study effects of ASE and MAE variables, and anthocyanin extracts were analyzed by spectrophotometry, high-performance liquid chromatography-diode array detector (DAD), and liquid chromatography-mass spectrometry chromatography. The extraction efficiency of ASE and MAE was comparable with CSE at the optimal conditions. The greatest extraction by ASE was achieved at 50 °C, 2500 psi, 10 min using 5 cycles, and 100% flush. For MAE, a combination of 70 °C, 300 W, and 10 min in MAE was the most effective in extracting anthocyanins from blue wheat and purple corn compared with 50 °C, 1200 W, and 20 min for black rice. The anthocyanin composition of grain extracts was influenced by the extraction method. The ASE extraction method seems to be more appropriate in extracting anthocyanins from the colored grains as being comparable with the CSE method based on changes in anthocyanin composition. The method caused lower structural changes in anthocaynins compared with the MAE method. Changes in blue wheat anthocyanins were lower in comparison with purple corn or black rice perhaps due to the absence of acylated anthocyanin compounds in blue wheat. The results show significant differences in anthocyanins among the 3 extraction methods, which indicate a need to standardize a method for valid comparisons among studies and for quality assurance purposes. © 2014 Her Majesty the Queen in Right of Canada Journal of Food Science © 2014 Institute of Food Technologists® Reproduced with the permission of the Minister of Agriculture and Agri-Food Canada.
Comparative study of two commercially pure titanium casting methods

PubMed Central

RODRIGUES, Renata Cristina Silveira; FARIA, Adriana Claudia Lapria; ORSI, Iara Augusta; de MATTOS, Maria da Gloria Chiarello; MACEDO, Ana Paula; RIBEIRO, Ricardo Faria

2010-01-01

The interest in using titanium to fabricate removable partial denture (RPD) frameworks has increased, but there are few studies evaluating the effects of casting methods on clasp behavior. Objective This study compared the occurrence of porosities and the retentive force of commercially pure titanium (CP Ti) and cobalt-chromium (Co-Cr) removable partial denture circumferential clasps cast by induction/centrifugation and plasma/vacuum-pressure. Material and Methods 72 frameworks were cast from CP Ti (n=36) and Co-Cr alloy (n=36; control group). For each material, 18 frameworks were casted by electromagnetic induction and injected by centrifugation, whereas the other 18 were casted by plasma and injected by vacuum-pressure. For each casting method, three subgroups (n=6) were formed: 0.25 mm, 0.50 mm, and 0.75 mm undercuts. The specimens were radiographed and subjected to an insertion/removal test simulating 5 years of framework use. Data were analyzed by ANOVA and Tukey's to compare materials and cast methods (α=0.05). Results Three of 18 specimens of the induction/centrifugation group and 9 of 18 specimens of plasma/vacuum-pressure cast presented porosities, but only 1 and 7 specimens, respectively, were rejected for simulation test. For Co-Cr alloy, no defects were found. Comparing the casting methods, statistically significant differences (p<0.05) were observed only for the Co-Cr alloy with 0.25 mm and 0.50 mm undercuts. Significant differences were found for the 0.25 mm and 0.75 mm undercuts dependent on the material used. For the 0.50 mm undercut, significant differences were found when the materials were induction casted. Conclusion Although both casting methods produced satisfactory CP Ti RPD frameworks, the occurrence of porosities was greater in the plasma/vacuum-pressure than in the induction/centrifugation method, the latter resulting in higher clasp rigidity, generating higher retention force values. PMID:21085805
Comparability analysis of protein therapeutics by bottom-up LC-MS with stable isotope-tagged reference standards

PubMed Central

Manuilov, Anton V; Radziejewski, Czeslaw H

2011-01-01

Comparability studies lie at the heart of assessments that evaluate differences amongst manufacturing processes and stability studies of protein therapeutics. Low resolution chromatographic and electrophoretic methods facilitate quantitation, but do not always yield detailed insight into the effect of the manufacturing change or environmental stress. Conversely, mass spectrometry (MS) can provide high resolution information on the molecule, but conventional methods are not very quantitative. This gap can be reconciled by use of a stable isotope-tagged reference standard (SITRS), a version of the analyte protein that is uniformly labeled with 13C6-arginine and 13C6-lysine. The SITRS serves as an internal control that is trypsin-digested and analyzed by liquid chromatography (LC)-MS with the analyte sample. The ratio of the ion intensities of each unlabeled and labeled peptide pair is then compared to that of other sample(s). A comparison of these ratios provides a readily accessible way to spot even minute differences among samples. In a study of a monoclonal antibody (mAb) spiked with varying amounts of the same antibody bearing point mutations, peptides containing the mutations were readily identified and quantified at concentrations as low as 2% relative to unmodified peptides. The method was robust, reproducible and produced a linear response for every peptide that was monitored. The method was also successfully used to distinguish between two batches of a mAb that were produced in two different cell lines while two batches produced from the same cell line were found to be highly comparable. Finally, the use of the SITRS method in the comparison of two stressed mAb samples enabled the identification of sites susceptible to deamidation and oxidation, as well as their quantitation. The experimental results indicate that use of a SITRS in a peptide mapping experiment with MS detection enables sensitive and quantitative comparability studies of proteins at high resolution. PMID:21654206
Comparability analysis of protein therapeutics by bottom-up LC-MS with stable isotope-tagged reference standards.

PubMed

Manuilov, Anton V; Radziejewski, Czeslaw H; Lee, David H

2011-01-01

Comparability studies lie at the heart of assessments that evaluate differences amongst manufacturing processes and stability studies of protein therapeutics. Low resolution chromatographic and electrophoretic methods facilitate quantitation, but do not always yield detailed insight into the effect of the manufacturing change or environmental stress. Conversely, mass spectrometry (MS) can provide high resolution information on the molecule, but conventional methods are not very quantitative. This gap can be reconciled by use of a stable isotope-tagged reference standard (SITRS), a version of the analyte protein that is uniformly labeled (13)C6-arginine and (13)C6-lysine. The SITRS serves as an internal control that is trypsin-digested and analyzed by liquid chromatography (LC)-MS with the analyte sample. The ratio of the ion intensities of each unlabeled and labeled peptide pair is then compared to that of other sample(s). A comparison of these ratios provides a readily accessible way to spot even minute differences among samples. In a study of a monoclonal antibody (mAb) spiked with varying amounts of the same antibody bearing point mutations, peptides containing the mutations were readily identified and quantified at concentrations as low as 2% relative to unmodified peptides. The method is robust, reproducible and produced a linear response for every peptide that was monitored. The method was also successfully used to distinguish between two batches of a mAb that were produced in two different cell lines while two batches produced from the same cell line were found to be highly comparable. Finally, the use of the SITRS method in the comparison of two stressed mAb samples enabled the identification of sites susceptible to deamidation and oxidation, as well as their quantitation. The experimental results indicate that use of a SITRS in a peptide mapping experiment with MS detection enables sensitive and quantitative comparability studies of proteins at high resolution.
A novel spinal kinematic analysis using X-ray imaging and vicon motion analysis: a case study.

PubMed

Noh, Dong K; Lee, Nam G; You, Joshua H

2014-01-01

This study highlights a novel spinal kinematic analysis method and the feasibility of X-ray imaging measurements to accurately assess thoracic spine motion. The advanced X-ray Nash-Moe method and analysis were used to compute the segmental range of motion in thoracic vertebra pedicles in vivo. This Nash-Moe X-ray imaging method was compared with a standardized method using the Vicon 3-dimensional motion capture system. Linear regression analysis showed an excellent and significant correlation between the two methods (R2 = 0.99, p < 0.05), suggesting that the analysis of spinal segmental range of motion using X-ray imaging measurements was accurate and comparable to the conventional 3-dimensional motion analysis system. Clinically, this novel finding is compelling evidence demonstrating that measurements with X-ray imaging are useful to accurately decipher pathological spinal alignment and movement impairments in idiopathic scoliosis (IS).
Numerical simulation for the air entrainment of aerated flow with an improved multiphase SPH model

NASA Astrophysics Data System (ADS)

Wan, Hang; Li, Ran; Pu, Xunchi; Zhang, Hongwei; Feng, Jingjie

2017-11-01

Aerated flow is a complex hydraulic phenomenon that exists widely in the field of environmental hydraulics. It is generally characterised by large deformation and violent fragmentation of the free surface. Compared to Euler methods (volume of fluid (VOF) method or rigid-lid hypothesis method), the existing single-phase Smooth Particle Hydrodynamics (SPH) method has performed well for solving particle motion. A lack of research on interphase interaction and air concentration, however, has affected the application of SPH model. In our study, an improved multiphase SPH model is presented to simulate aeration flows. A drag force was included in the momentum equation to ensure accuracy of the air particle slip velocity. Furthermore, a calculation method for air concentration is developed to analyse the air entrainment characteristics. Two studies were used to simulate the hydraulic and air entrainment characteristics. And, compared with the experimental results, the simulation results agree with the experimental results well.
An efficient graph theory based method to identify every minimal reaction set in a metabolic network

PubMed Central

2014-01-01

Background Development of cells with minimal metabolic functionality is gaining importance due to their efficiency in producing chemicals and fuels. Existing computational methods to identify minimal reaction sets in metabolic networks are computationally expensive. Further, they identify only one of the several possible minimal reaction sets. Results In this paper, we propose an efficient graph theory based recursive optimization approach to identify all minimal reaction sets. Graph theoretical insights offer systematic methods to not only reduce the number of variables in math programming and increase its computational efficiency, but also provide efficient ways to find multiple optimal solutions. The efficacy of the proposed approach is demonstrated using case studies from Escherichia coli and Saccharomyces cerevisiae. In case study 1, the proposed method identified three minimal reaction sets each containing 38 reactions in Escherichia coli central metabolic network with 77 reactions. Analysis of these three minimal reaction sets revealed that one of them is more suitable for developing minimal metabolism cell compared to other two due to practically achievable internal flux distribution. In case study 2, the proposed method identified 256 minimal reaction sets from the Saccharomyces cerevisiae genome scale metabolic network with 620 reactions. The proposed method required only 4.5 hours to identify all the 256 minimal reaction sets and has shown a significant reduction (approximately 80%) in the solution time when compared to the existing methods for finding minimal reaction set. Conclusions Identification of all minimal reactions sets in metabolic networks is essential since different minimal reaction sets have different properties that effect the bioprocess development. The proposed method correctly identified all minimal reaction sets in a both the case studies. The proposed method is computationally efficient compared to other methods for finding minimal reaction sets and useful to employ with genome-scale metabolic networks. PMID:24594118
Statistical Methods for Detecting Differentially Abundant Features in Clinical Metagenomic Samples

PubMed Central

White, James Robert; Nagarajan, Niranjan; Pop, Mihai

2009-01-01

Numerous studies are currently underway to characterize the microbial communities inhabiting our world. These studies aim to dramatically expand our understanding of the microbial biosphere and, more importantly, hope to reveal the secrets of the complex symbiotic relationship between us and our commensal bacterial microflora. An important prerequisite for such discoveries are computational tools that are able to rapidly and accurately compare large datasets generated from complex bacterial communities to identify features that distinguish them. We present a statistical method for comparing clinical metagenomic samples from two treatment populations on the basis of count data (e.g. as obtained through sequencing) to detect differentially abundant features. Our method, Metastats, employs the false discovery rate to improve specificity in high-complexity environments, and separately handles sparsely-sampled features using Fisher's exact test. Under a variety of simulations, we show that Metastats performs well compared to previously used methods, and significantly outperforms other methods for features with sparse counts. We demonstrate the utility of our method on several datasets including a 16S rRNA survey of obese and lean human gut microbiomes, COG functional profiles of infant and mature gut microbiomes, and bacterial and viral metabolic subsystem data inferred from random sequencing of 85 metagenomes. The application of our method to the obesity dataset reveals differences between obese and lean subjects not reported in the original study. For the COG and subsystem datasets, we provide the first statistically rigorous assessment of the differences between these populations. The methods described in this paper are the first to address clinical metagenomic datasets comprising samples from multiple subjects. Our methods are robust across datasets of varied complexity and sampling level. While designed for metagenomic applications, our software can also be applied to digital gene expression studies (e.g. SAGE). A web server implementation of our methods and freely available source code can be found at http://metastats.cbcb.umd.edu/. PMID:19360128
Quantitative Evaluation of Automated Skull-Stripping Methods Applied to Contemporary and Legacy Images: Effects of Diagnosis, Bias Correction, and Slice Location

PubMed Central

Fennema-Notestine, Christine; Ozyurt, I. Burak; Clark, Camellia P.; Morris, Shaunna; Bischoff-Grethe, Amanda; Bondi, Mark W.; Jernigan, Terry L.; Fischl, Bruce; Segonne, Florent; Shattuck, David W.; Leahy, Richard M.; Rex, David E.; Toga, Arthur W.; Zou, Kelly H.; BIRN, Morphometry; Brown, Gregory G.

2008-01-01

Performance of automated methods to isolate brain from nonbrain tissues in magnetic resonance (MR) structural images may be influenced by MR signal inhomogeneities, type of MR image set, regional anatomy, and age and diagnosis of subjects studied. The present study compared the performance of four methods: Brain Extraction Tool (BET; Smith [2002]: Hum Brain Mapp 17:143–155); 3dIntracranial (Ward [1999] Milwaukee: Biophysics Research Institute, Medical College of Wisconsin; in AFNI); a Hybrid Watershed algorithm (HWA, Segonne et al. [2004] Neuroimage 22:1060–1075; in FreeSurfer); and Brain Surface Extractor (BSE, Sandor and Leahy [1997] IEEE Trans Med Imag 16:41–54; Shattuck et al. [2001] Neuroimage 13:856 – 876) to manually stripped images. The methods were applied to uncorrected and bias-corrected datasets; Legacy and Contemporary T1-weighted image sets; and four diagnostic groups (depressed, Alzheimer’s, young and elderly control). To provide a criterion for outcome assessment, two experts manually stripped six sagittal sections for each dataset in locations where brain and nonbrain tissue are difficult to distinguish. Methods were compared on Jaccard similarity coefficients, Hausdorff distances, and an Expectation-Maximization algorithm. Methods tended to perform better on contemporary datasets; bias correction did not significantly improve method performance. Mesial sections were most difficult for all methods. Although AD image sets were most difficult to strip, HWA and BSE were more robust across diagnostic groups compared with 3dIntracranial and BET. With respect to specificity, BSE tended to perform best across all groups, whereas HWA was more sensitive than other methods. The results of this study may direct users towards a method appropriate to their T1-weighted datasets and improve the efficiency of processing for large, multisite neuroimaging studies. PMID:15986433
Physical methods for treating fever in children.

PubMed

Meremikwu, M; Oyo-Ita, A

2003-01-01

Health workers recommend bathing, sponging and other physical methods to treat fever in children and to avoid febrile convulsions. We know little about the most effective methods, or how these methods compare with commonly used drugs. To evaluate the benefits and harms of physical cooling methods used for managing fever in children. We searched the Cochrane Infectious Diseases Group specialized trials register (February 2003), the Cochrane Central Register of Controlled Trials (Issue 1, 2003), MEDLINE (1966 to February 2003), EMBASE (1988 to November 2002), CINHAL (1982 to February 2003), LILACS (February 2003), Science Citation Index (1981 to February 2003), and reference lists of articles. We also contacted researchers in the field. Randomized and quasi-randomized trials comparing physical methods with a drug placebo or no treatment in children with fever of presumed infectious origin. Studies where children in both groups were given an antipyretic drug were included. Two reviewers independently assessed trial methodological quality. One reviewer extracted data and the other checked the data for accuracy. Results were expressed as Relative Risk (RR) with 95% confidence intervals (CI) for discrete variables, and weighted mean differences for continuous outcomes. Seven trials, involving 467 participants, met the inclusion criteria. One small trial (n = 30), comparing physical methods with drug placebo, did not demonstrate a difference in the proportion of children without fever by one hour after treatment in a comparison between physical methods alone and drug placebo. In 2 studies, where all children received an anti-pyretic drug, physical methods resulted in a higher proportion of children without fever at one hour (n=125, RR 11.8, CI 3.39 to 40.8). I; in a third study (n=130), which only reported mean change in temperature, no differences wereas detected. Mild adverse events (shivering and goose pimples) were more common in the physical methods group (3 trials, RR 5.09; CI 1.56 to 16.60). A few small studies demonstrate that tepid sponging helps to reduce fever in children.
Comparing the effects of low-dose contraceptive pills to control dysfunctional uterine bleeding by oral and vaginal methods.

PubMed

Mehrabian, Ferdous; Abbassi, Fariba

2013-09-01

Background and Objective : Contraceptive pills are generally taken orally and can cause side effects such as nausea, vomiting and hypertension. The vaginal use of these pills can reduce such complications. Our objective was to compare the efficacy and side effects of low dose contraceptive pills by oral and vaginal route in the management of dysfunctional uterine bleeding-(DUB) Methods: This comparative observational study was conducted at Beheshti and Alzahra (SA) teaching hospitals, affiliated to Isfahan University of Medical Sciences in 2010-2011. One hundred women who presented with DUB were randomly assigned into two groups of equal number, receiving the low dose oral contraceptive pills by oral or vaginal route for three month. The amount and duration of bleeding were compared at the beginning and at the end of the study and side effects by these two methods compared. The results of this study showed that both oral and vaginal routes effectively reduced the duration and amount of bleeding due to DUB after three courses of treatment. This effect was better in the vaginal method compared with oral administration (P = 0.03). Regarding the side effects, nausea and vomiting were significantly higher in the oral group than in the vaginal group (P = 0.03). Vulvovaginitis infection was more frequent in the vaginal group than in the oral group (P = 0.03). Low dose contraceptive pills are effective in reducing the amount, time, and duration of bleeding in patients with DUB. In addition, reduction of gastrointestinal side effects by vaginal route helps to use these pills by the patient with proper training of physicians, midwives and patients.
Costs and Efficiency of Online and Offline Recruitment Methods: A Web-Based Cohort Study

PubMed Central

Riis, Anders H; Hatch, Elizabeth E; Wise, Lauren A; Nielsen, Marie G; Rothman, Kenneth J; Toft Sørensen, Henrik; Mikkelsen, Ellen M

2017-01-01

Background The Internet is widely used to conduct research studies on health issues. Many different methods are used to recruit participants for such studies, but little is known about how various recruitment methods compare in terms of efficiency and costs. Objective The aim of our study was to compare online and offline recruitment methods for Internet-based studies in terms of efficiency (number of recruited participants) and costs per participant. Methods We employed several online and offline recruitment methods to enroll 18- to 45-year-old women in an Internet-based Danish prospective cohort study on fertility. Offline methods included press releases, posters, and flyers. Online methods comprised advertisements placed on five different websites, including Facebook and Netdoktor.dk. We defined seven categories of mutually exclusive recruitment methods and used electronic tracking via unique Uniform Resource Locator (URL) and self-reported data to identify the recruitment method for each participant. For each method, we calculated the average cost per participant and efficiency, that is, the total number of recruited participants. Results We recruited 8252 study participants. Of these, 534 were excluded as they could not be assigned to a specific recruitment method. The final study population included 7724 participants, of whom 803 (10.4%) were recruited by offline methods, 3985 (51.6%) by online methods, 2382 (30.8%) by online methods not initiated by us, and 554 (7.2%) by other methods. Overall, the average cost per participant was €6.22 for online methods initiated by us versus €9.06 for offline methods. Costs per participant ranged from €2.74 to €105.53 for online methods and from €0 to €67.50 for offline methods. Lowest average costs per participant were for those recruited from Netdoktor.dk (€2.99) and from Facebook (€3.44). Conclusions In our Internet-based cohort study, online recruitment methods were superior to offline methods in terms of efficiency (total number of participants enrolled). The average cost per recruited participant was also lower for online than for offline methods, although costs varied greatly among both online and offline recruitment methods. We observed a decrease in the efficiency of some online recruitment methods over time, suggesting that it may be optimal to adopt multiple online methods. PMID:28249833
A New Method for Xenogeneic Bone Graft Deproteinization: Comparative Study of Radius Defects in a Rabbit Model

PubMed Central

Lei, Pengfei; Sun, Rongxin; Wang, Long; Zhou, Jialin; Wan, Lifei; Zhou, Tianjian; Hu, Yihe

2015-01-01

Background and Objectives Deproteinization is an indispensable process for the elimination of antigenicity in xenograft bones. However, the hydrogen peroxide (H2O2) deproteinized xenograft, which is commonly used to repair bone defect, exhibits limited osteoinduction activity. The present study was designed to develop a new method for deproteinization and compare the osteogenic capacities of new pepsin deproteinized xenograft bones with those of conventional H2O2 deproteinized ones. Methods Bones were deproteinized in H2O2 or pepsin for 8 hours. The morphologies were compared by HE staining. The content of protein and collagen I were measured by the Kjeldahl method and HPLC-MS, respectively. The physical properties were evaluated by SEM and mechanical tests. For in vivo study, X-ray, micro-CT and HE staining were employed to monitor the healing processes of radius defects in rabbit models transplanted with different graft materials. Results Compared with H2O2 deproteinized bones, no distinct morphological and physical changes were observed. However, pepsin deproteinized bones showed a lower protein content, and a higher collagen content were preserved. In vivo studies showed that pepsin deproteinized bones exhibited better osteogenic performance than H2O2 deproteinized bones, moreover, the quantity and quality of the newly formed bones were improved as indicated by micro-CT analysis. From the results of histological examination, the newly formed bones in the pepsin group were mature bones. Conclusions Pepsin deproteinized xenograft bones show advantages over conventional H2O2 deproteinized bones with respect to osteogenic capacity; this new method may hold potential clinical value in the development of new biomaterials for bone grafting. PMID:26719896
Comparison of Elementary Social Studies Curricula of Turkey and the United States on Values Education

ERIC Educational Resources Information Center

Merey, Zihni; Kus, Zafer; Karatekin, Kadir

2012-01-01

The purpose of this study is to compare the social studies teaching curricula of Turkey and the United States in terms of values education. The study is a model case study that relies upon one of the qualitative research methods. The data come from the elementary social studies curricula of both countries through the documents analysis method. The…
New method of scoliosis assessment: preliminary results using computerized photogrammetry.

PubMed

Aroeira, Rozilene Maria Cota; Leal, Jefferson Soares; de Melo Pertence, Antônio Eustáquio

2011-09-01

A new method for nonradiographic evaluation of scoliosis was independently compared with the Cobb radiographic method, for the quantification of scoliotic curvature. To develop a protocol for computerized photogrammetry, as a nonradiographic method, for the quantification of scoliosis, and to mathematically relate this proposed method with the Cobb radiographic method. Repeated exposure to radiation of children can be harmful to their health. Nevertheless, no nonradiographic method until now proposed has gained popularity as a routine method for evaluation, mainly due to a low correspondence to the Cobb radiographic method. Patients undergoing standing posteroanterior full-length spine radiographs, who were willing to participate in this study, were submitted to dorsal digital photography in the orthostatic position with special surface markers over the spinous process, specifically the vertebrae C7 to L5. The radiographic and photographic images were sent separately for independent analysis to two examiners, trained in quantification of scoliosis for the types of images received. The scoliosis curvature angles obtained through computerized photogrammetry (the new method) were compared to those obtained through the Cobb radiographic method. Sixteen individuals were evaluated (14 female and 2 male). All presented idiopathic scoliosis, and were between 21.4 ± 6.1 years of age; 52.9 ± 5.8 kg in weight; 1.63 ± 0.05 m in height, with a body mass index of 19.8 ± 0.2. There was no statistically significant difference between the scoliosis angle measurements obtained in the comparative analysis of both methods, and a mathematical relationship was formulated between both methods. The preliminary results presented demonstrate equivalence between the two methods. More studies are needed to firmly assess the potential of this new method as a coadjuvant tool in the routine following of scoliosis treatment.

Efficiencies of joint non-local update moves in Monte Carlo simulations of coarse-grained polymers

NASA Astrophysics Data System (ADS)

Austin, Kieran S.; Marenz, Martin; Janke, Wolfhard

2018-03-01

In this study four update methods are compared in their performance in a Monte Carlo simulation of polymers in continuum space. The efficiencies of the update methods and combinations thereof are compared with the aid of the autocorrelation time with a fixed (optimal) acceptance ratio. Results are obtained for polymer lengths N = 14, 28 and 42 and temperatures below, at and above the collapse transition. In terms of autocorrelation, the optimal acceptance ratio is approximately 0.4. Furthermore, an overview of the step sizes of the update methods that correspond to this optimal acceptance ratio is given. This shall serve as a guide for future studies that rely on efficient computer simulations.
COMPARISON OF MACROINVERTEBRATE SAMPLING METHODS FOR NONWADEABLE STREAMS

EPA Science Inventory

The bioassessment of nonwadeable streams in the United States is increasing, but methods for these systems are not as well developed as for wadeable streams. In this study, we compared six benthic macroinvertebrate field sampling methods for nonwadeable streams based on those us...
Fuzzy decision-making framework for treatment selection based on the combined QUALIFLEX-TODIM method

NASA Astrophysics Data System (ADS)

Ji, Pu; Zhang, Hong-yu; Wang, Jian-qiang

2017-10-01

Treatment selection is a multi-criteria decision-making problem of significant concern in the medical field. In this study, a fuzzy decision-making framework is established for treatment selection. The framework mitigates information loss by introducing single-valued trapezoidal neutrosophic numbers to denote evaluation information. Treatment selection has multiple criteria that remarkably exceed the alternatives. In consideration of this characteristic, the framework utilises the idea of the qualitative flexible multiple criteria method. Furthermore, it considers the risk-averse behaviour of a decision maker by employing a concordance index based on TODIM (an acronym in Portuguese of interactive and multi-criteria decision-making) method. A sensitivity analysis is performed to illustrate the robustness of the framework. Finally, a comparative analysis is conducted to compare the framework with several extant methods. Results indicate the advantages of the framework and its better performance compared with the extant methods.
Comparative study of 2D ultrasound imaging methods in the f-k domain and evaluation of their performances in a realistic NDT configuration

NASA Astrophysics Data System (ADS)

Merabet, Lucas; Robert, Sébastien; Prada, Claire

2018-04-01

In this paper, we present two frequency-domain algorithms for 2D imaging with plane wave emissions, namely Stolt's migration and Lu's method. The theoretical background is first presented, followed by an analysis of the algorithm complexities. The frequency-domain methods are then compared to the time-domain plane wave imaging in a realistic inspection configuration where the array elements are not in contact with the specimen. Imaging defects located far away from the array aperture is assessed and computation times for the three methods are presented as a function of the number of pixels of the reconstructed image. We show that Lu's method provides a time gain of up to 33 compared to the time-domain algorithm, and demonstrate the limitations of Stolt's migration for defects far away from the aperture.
Methodological Reporting in Qualitative, Quantitative, and Mixed Methods Health Services Research Articles

PubMed Central

Wisdom, Jennifer P; Cavaleri, Mary A; Onwuegbuzie, Anthony J; Green, Carla A

2012-01-01

Objectives Methodologically sound mixed methods research can improve our understanding of health services by providing a more comprehensive picture of health services than either method can alone. This study describes the frequency of mixed methods in published health services research and compares the presence of methodological components indicative of rigorous approaches across mixed methods, qualitative, and quantitative articles. Data Sources All empirical articles (n = 1,651) published between 2003 and 2007 from four top-ranked health services journals. Study Design All mixed methods articles (n = 47) and random samples of qualitative and quantitative articles were evaluated to identify reporting of key components indicating rigor for each method, based on accepted standards for evaluating the quality of research reports (e.g., use of p-values in quantitative reports, description of context in qualitative reports, and integration in mixed method reports). We used chi-square tests to evaluate differences between article types for each component. Principal Findings Mixed methods articles comprised 2.85 percent (n = 47) of empirical articles, quantitative articles 90.98 percent (n = 1,502), and qualitative articles 6.18 percent (n = 102). There was a statistically significant difference (χ2(1) = 12.20, p = .0005, Cramer's V = 0.09, odds ratio = 1.49 [95% confidence interval = 1,27, 1.74]) in the proportion of quantitative methodological components present in mixed methods compared to quantitative papers (21.94 versus 47.07 percent, respectively) but no statistically significant difference (χ2(1) = 0.02, p = .89, Cramer's V = 0.01) in the proportion of qualitative methodological components in mixed methods compared to qualitative papers (21.34 versus 25.47 percent, respectively). Conclusion Few published health services research articles use mixed methods. The frequency of key methodological components is variable. Suggestions are provided to increase the transparency of mixed methods studies and the presence of key methodological components in published reports. PMID:22092040
Comparative Evaluation of Three Methods (Microscopic Examination, Direct Fluorescent Antibody Assay, and Immunochromatographic Method) for the Diagnosis of Giardia intestinalis From Stool Specimens.

PubMed

Karadam, Senem Yaman; Ertuğ, Sema; Ertabaklar, Hatice

2016-03-01

The aim of this study was to compare direct microscopic examination, direct fluorescent antibody assay (DFA), and the immunochromatographic method (IK) and identify the best suitable method for the diagnosis of Giardia intestinalis. In this study, 25 stool samples that had been diagnosed as being infected with G. intestinalis using the native-Lugol and/or formol-ethyl acetate concentration method and 25 non-parasite-infected samples (the control group) were examined. After microscopic examination of stools, they were kept at -20°C for examination using DFA and IK. Stool samples were studied using DFA (CeLLabs, Crypto/Giardia-Cel IF) and IK (RIDA QUICK, Cryptosporidium/Giardia Combi Dipstick), as per the manufacturers' instructions. In our study, using the DFA method, parasites were detected in all 25 stool samples in which G. intestinalis was diagnosed by direct microscopic examination. Using the IK method, a particular band indicative of the parasite was detected in 24 samples. No parasites were detected in all 25 samples in the control group. Thus, when direct microscopic examination is taken as reference, the senstivity and specificity of DFA for the diagnosis of G. intestinalis were found to be 100% each, while those of IK were found to be 96% and 100%, respectively.
Quantifying the accuracy of the tumor motion and area as a function of acceleration factor for the simulation of the dynamic keyhole magnetic resonance imaging method

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

Lee, Danny; Pollock, Sean; Keall, Paul, E-mail: paul.keall@sydney.edu.au

2016-05-15

Purpose: The dynamic keyhole is a new MR image reconstruction method for thoracic and abdominal MR imaging. To date, this method has not been investigated with cancer patient magnetic resonance imaging (MRI) data. The goal of this study was to assess the dynamic keyhole method for the task of lung tumor localization using cine-MR images reconstructed in the presence of respiratory motion. Methods: The dynamic keyhole method utilizes a previously acquired a library of peripheral k-space datasets at similar displacement and phase (where phase is simply used to determine whether the breathing is inhale to exhale or exhale to inhale)more » respiratory bins in conjunction with central k-space datasets (keyhole) acquired. External respiratory signals drive the process of sorting, matching, and combining the two k-space streams for each respiratory bin, thereby achieving faster image acquisition without substantial motion artifacts. This study was the first that investigates the impact of k-space undersampling on lung tumor motion and area assessment across clinically available techniques (zero-filling and conventional keyhole). In this study, the dynamic keyhole, conventional keyhole and zero-filling methods were compared to full k-space dataset acquisition by quantifying (1) the keyhole size required for central k-space datasets for constant image quality across sixty four cine-MRI datasets from nine lung cancer patients, (2) the intensity difference between the original and reconstructed images in a constant keyhole size, and (3) the accuracy of tumor motion and area directly measured by tumor autocontouring. Results: For constant image quality, the dynamic keyhole method, conventional keyhole, and zero-filling methods required 22%, 34%, and 49% of the keyhole size (P < 0.0001), respectively, compared to the full k-space image acquisition method. Compared to the conventional keyhole and zero-filling reconstructed images with the keyhole size utilized in the dynamic keyhole method, an average intensity difference of the dynamic keyhole reconstructed images (P < 0.0001) was minimal, and resulted in the accuracy of tumor motion within 99.6% (P < 0.0001) and the accuracy of tumor area within 98.0% (P < 0.0001) for lung tumor monitoring applications. Conclusions: This study demonstrates that the dynamic keyhole method is a promising technique for clinical applications such as image-guided radiation therapy requiring the MR monitoring of thoracic tumors. Based on the results from this study, the dynamic keyhole method could increase the imaging frequency by up to a factor of five compared with full k-space methods for real-time lung tumor MRI.« less
Generalizing observational study results: applying propensity score methods to complex surveys.

PubMed

Dugoff, Eva H; Schuler, Megan; Stuart, Elizabeth A

2014-02-01

To provide a tutorial for using propensity score methods with complex survey data. Simulated data and the 2008 Medical Expenditure Panel Survey. Using simulation, we compared the following methods for estimating the treatment effect: a naïve estimate (ignoring both survey weights and propensity scores), survey weighting, propensity score methods (nearest neighbor matching, weighting, and subclassification), and propensity score methods in combination with survey weighting. Methods are compared in terms of bias and 95 percent confidence interval coverage. In Example 2, we used these methods to estimate the effect on health care spending of having a generalist versus a specialist as a usual source of care. In general, combining a propensity score method and survey weighting is necessary to achieve unbiased treatment effect estimates that are generalizable to the original survey target population. Propensity score methods are an essential tool for addressing confounding in observational studies. Ignoring survey weights may lead to results that are not generalizable to the survey target population. This paper clarifies the appropriate inferences for different propensity score methods and suggests guidelines for selecting an appropriate propensity score method based on a researcher's goal. © Health Research and Educational Trust.
Influence of 2 cryopreservation methods to induce CCL-13 from dental pulp cells.

PubMed

Ahn, Su-Jin; Jang, Ji-Hyun; Seo, Ji-Sung; Cho, Kyu Min; Jung, Su-Hee; Lee, Hyeon-Woo; Kim, Eun-Cheol; Park, Sang Hyuk

2013-12-01

Cryopreservation preserves periodontal ligament cells but has a lower success rate with dental pulp cells (DPCs) because it causes inflammation. There are 2 well-known cryopreservation methods that reduce inflammation, slow freezing and rapid freezing, but the effects of the 2 methods on inflammation are not well-established. The purpose of this study was to compare the effects of the 2 different cryopreservation methods on CCL-13 induction from DPCs by using microarrays, real-time polymerase chain reaction (PCR), Western blotting, enzyme-linked immunosorbent assay, and confocal laser scanning microscopy (CLSM). In this study, the concentration of cryoprotectant was fixed, and the methods compared differed with respect to freezing speed. Initially we screened the DPCs of cryopreserved teeth with expression microarrays, and CCL-13 was identified as a differentially expressed gene involved in generalized inflammation. We then compared the expression of CCL-13 after exposing teeth to the 2 cryopreservation methods by using real-time PCR, Western blot, enzyme-linked immunosorbent assay, and CLSM. Expression of CCL-13 was up-regulated significantly only in the rapid freezing group, except in measurements made by real-time PCR. CLSM analysis also confirmed this up-regulation visually. Rapid freezing increased the expression of CCL-13 in DPCs compared with slow freezing. Understanding the inflammatory effect of cryopreservation should help to establish an optimal cryoprofile to minimize inflammation of DPCs and reduce the need for endodontic treatment. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
Automation of Classical QEEG Trending Methods for Early Detection of Delayed Cerebral Ischemia: More Work to Do.

PubMed

Wickering, Ellis; Gaspard, Nicolas; Zafar, Sahar; Moura, Valdery J; Biswal, Siddharth; Bechek, Sophia; OʼConnor, Kathryn; Rosenthal, Eric S; Westover, M Brandon

2016-06-01

The purpose of this study is to evaluate automated implementations of continuous EEG monitoring-based detection of delayed cerebral ischemia based on methods used in classical retrospective studies. We studied 95 patients with either Fisher 3 or Hunt Hess 4 to 5 aneurysmal subarachnoid hemorrhage who were admitted to the Neurosciences ICU and underwent continuous EEG monitoring. We implemented several variations of two classical algorithms for automated detection of delayed cerebral ischemia based on decreases in alpha-delta ratio and relative alpha variability. Of 95 patients, 43 (45%) developed delayed cerebral ischemia. Our automated implementation of the classical alpha-delta ratio-based trending method resulted in a sensitivity and specificity (Se,Sp) of (80,27)%, compared with the values of (100,76)% reported in the classic study using similar methods in a nonautomated fashion. Our automated implementation of the classical relative alpha variability-based trending method yielded (Se,Sp) values of (65,43)%, compared with (100,46)% reported in the classic study using nonautomated analysis. Our findings suggest that improved methods to detect decreases in alpha-delta ratio and relative alpha variability are needed before an automated EEG-based early delayed cerebral ischemia detection system is ready for clinical use.
Parameter estimation method that directly compares gravitational wave observations to numerical relativity

NASA Astrophysics Data System (ADS)

Lange, J.; O'Shaughnessy, R.; Boyle, M.; Calderón Bustillo, J.; Campanelli, M.; Chu, T.; Clark, J. A.; Demos, N.; Fong, H.; Healy, J.; Hemberger, D. A.; Hinder, I.; Jani, K.; Khamesra, B.; Kidder, L. E.; Kumar, P.; Laguna, P.; Lousto, C. O.; Lovelace, G.; Ossokine, S.; Pfeiffer, H.; Scheel, M. A.; Shoemaker, D. M.; Szilagyi, B.; Teukolsky, S.; Zlochower, Y.

2017-11-01

We present and assess a Bayesian method to interpret gravitational wave signals from binary black holes. Our method directly compares gravitational wave data to numerical relativity (NR) simulations. In this study, we present a detailed investigation of the systematic and statistical parameter estimation errors of this method. This procedure bypasses approximations used in semianalytical models for compact binary coalescence. In this work, we use the full posterior parameter distribution for only generic nonprecessing binaries, drawing inferences away from the set of NR simulations used, via interpolation of a single scalar quantity (the marginalized log likelihood, ln L ) evaluated by comparing data to nonprecessing binary black hole simulations. We also compare the data to generic simulations, and discuss the effectiveness of this procedure for generic sources. We specifically assess the impact of higher order modes, repeating our interpretation with both l ≤2 as well as l ≤3 harmonic modes. Using the l ≤3 higher modes, we gain more information from the signal and can better constrain the parameters of the gravitational wave signal. We assess and quantify several sources of systematic error that our procedure could introduce, including simulation resolution and duration; most are negligible. We show through examples that our method can recover the parameters for equal mass, zero spin, GW150914-like, and unequal mass, precessing spin sources. Our study of this new parameter estimation method demonstrates that we can quantify and understand the systematic and statistical error. This method allows us to use higher order modes from numerical relativity simulations to better constrain the black hole binary parameters.
Simultaneous multiplicative column-normalized method (SMART) for 3-D ionosphere tomography in comparison to other algebraic methods

NASA Astrophysics Data System (ADS)

Gerzen, T.; Minkwitz, D.

2016-01-01

The accuracy and availability of satellite-based applications like GNSS positioning and remote sensing crucially depends on the knowledge of the ionospheric electron density distribution. The tomography of the ionosphere is one of the major tools to provide link specific ionospheric corrections as well as to study and monitor physical processes in the ionosphere. In this paper, we introduce a simultaneous multiplicative column-normalized method (SMART) for electron density reconstruction. Further, SMART+ is developed by combining SMART with a successive correction method. In this way, a balancing between the measurements of intersected and not intersected voxels is realised. The methods are compared with the well-known algebraic reconstruction techniques ART and SART. All the four methods are applied to reconstruct the 3-D electron density distribution by ingestion of ground-based GNSS TEC data into the NeQuick model. The comparative case study is implemented over Europe during two periods of the year 2011 covering quiet to disturbed ionospheric conditions. In particular, the performance of the methods is compared in terms of the convergence behaviour and the capability to reproduce sTEC and electron density profiles. For this purpose, independent sTEC data of four IGS stations and electron density profiles of four ionosonde stations are taken as reference. The results indicate that SMART significantly reduces the number of iterations necessary to achieve a predefined accuracy level. Further, SMART+ decreases the median of the absolute sTEC error up to 15, 22, 46 and 67 % compared to SMART, SART, ART and NeQuick respectively.
Combining Heterogeneous Correlation Matrices: Simulation Analysis of Fixed-Effects Methods

ERIC Educational Resources Information Center

Hafdahl, Adam R.

2008-01-01

Monte Carlo studies of several fixed-effects methods for combining and comparing correlation matrices have shown that two refinements improve estimation and inference substantially. With rare exception, however, these simulations have involved homogeneous data analyzed using conditional meta-analytic procedures. The present study builds on…
Critical evaluations of vegetation cover measurement techniques: a response to Thacker et al. (2015)

USDA-ARS?s Scientific Manuscript database

Comparison studies are necessary to reconcile methods that have arisen among disparate rangeland monitoring programs. However, Thacker et al.'s study comparing Daubenmire frame (DF) and line-point intercept (LPI) methods for estimating vegetation cover ignores definitional differences between what t...
New method to enhance the extraction yield of rutin from Sophora japonica using a novel ultrasonic extraction system by determining optimum ultrasonic frequency.

PubMed

Liao, Jianqing; Qu, Baida; Liu, Da; Zheng, Naiqin

2015-11-01

A new method has been proposed for enhancing extraction yield of rutin from Sophora japonica, in which a novel ultrasonic extraction system has been developed to perform the determination of optimum ultrasonic frequency by a two-step procedure. This study has systematically investigated the influence of a continuous frequency range of 20-92 kHz on rutin yields. The effects of different operating conditions on rutin yields have also been studied in detail such as solvent concentration, solvent to solid ratio, ultrasound power, temperature and particle size. A higher extraction yield was obtained at the ultrasonic frequency of 60-62 kHz which was little affected under other extraction conditions. Comparative studies between existing methods and the present method were done to verify the effectiveness of this method. Results indicated that the new extraction method gave a higher extraction yield compared with existing ultrasound-assisted extraction (UAE) and soxhlet extraction (SE). Thus, the potential use of this method may be promising for extraction of natural materials on an industrial scale in the future. Copyright © 2015 Elsevier B.V. All rights reserved.
A novel reversed-phase HPLC method for the determination of urinary creatinine by pre-column derivatization with ethyl chloroformate: comparative studies with the standard Jaffé and isotope-dilution mass spectrometric assays.

PubMed

Leung, Elvis M K; Chan, Wan

2014-02-01

Creatinine is an important biomarker for renal function diagnosis and normalizing variations in urinary drug/metabolites concentration. Quantification of creatinine in biological fluids such as urine and plasma is important for clinical diagnosis as well as in biomonitoring programs and urinary metabolomics/metabonomics research. Current methods for creatinine determination either are nonselective or involve the use of expensive mass spectrometers. In this paper, a novel reversed-phase high-performance liquid chromatographic (HPLC) method for the determination of creatinine of high hydrophilicity by pre-column derivatization with ethyl chloroformate is presented. N-Ethyloxycarbonylation of creatinine significantly enhanced the hydrophobicity of creatinine, facilitating its chromatographic retention as well as quantification by HPLC. Factors governing the derivatization reaction were studied and optimized. The developed method was validated and applied for the determination of creatinine in rat urine samples. Comparative studies with isotope-dilution mass spectrometric method revealed that the two methods do not yield systematic differences in creatinine concentrations, indicating the HPLC method is suitable for the determination of creatinine in urine samples.
Effects of problem-based learning in Chinese radiology education

PubMed Central

Zhang, Song; Xu, Jiancheng; Wang, Hongwei; Zhang, Dong; Zhang, Qichuan; Zou, Liguang

2018-01-01

Abstract Background: In recent years, the problem-based learning (PBL) teaching method has been extensively applied as an experimental educational method in Chinese radiology education. However, the results of individual studies were inconsistent and inconclusive. A meta-analysis was performed to evaluate the effects of PBL on radiology education in China. Methods: Databases of Chinese and English languages were searched from inception up to November 2017. The standard mean difference (SMD) with its 95% confidence interval (95% CI) was used to determine the over effects of PBL compared with the traditional teaching method. Results: Seventeen studies involving 1487 participants were included in this meta-analysis. Of them, 16 studies provided sufficient data for the pooled analysis and showed that PBL teaching method had a positive effect on achieving higher theoretical scores compared with the traditional teaching method (SMD = 1.20, 95% CI [0.68, 1.71]). Thirteen studies provided sufficient data on skill scores, and a significant difference in favor of PBL was also observed (SMD = 2.10, 95% CI [1.38, 2.83]). Questionnaire surveys were applied in most of the included studies and indicated positive effects of PBL on students’ learning interest, scope of knowledge, team spirit, and oral expression. Conclusion: The result shows that PBL appears to be more effective on radiology education than traditional teaching method in China. However, the heterogeneity of the included studies cannot be neglected. Further well-designed studies about this topic are needed to confirm the above findings. PMID:29489669
Bone implant sockets made using three different procedures: a stability study in dogs

PubMed Central

Campo, Julián

2012-01-01

Objective: This study compared the effects of three different methods of preparing bone implant sockets (drilling, osteotomes, and piezoelectric device) on osseointegration using resonance frequency analysis (RFA). Study Design: An experimental prospective study was designed. Material and Methods: Ten adult beagle dogs were studied. After 5 weeks, 23 out of 28 initially placed implants in the iliac crest were evaluated, comparing these three different procedures of bone implant socket. Student’s t-test (paired, two-tailed) was used to reveal differences among the three groups at each time point (SPSS 16.0, IL, USA). Results: After a 5-week healing period, the implants placed in sockets that were made using an osteotome or piezoelectric device were slightly more stable than those made by drilling. Reduced mechanical and heat injury to the bone is beneficial for maintaining and improving stability during the critical early healing period. Conclusion: Using RFA, there was evidence of a slight increase in implant stability in the iliac crest after 5 weeks of healing when the implant socket was made using a piezoelectric device or expansion procedure as compare with the drilling method. Key words:Bone implant sockets, drilling, osteotomes, piezoelectric, resonance frequency analysis, stability. PMID:24558558
A comparative simulation study of AR(1) estimators in short time series.

PubMed

Krone, Tanja; Albers, Casper J; Timmerman, Marieke E

2017-01-01

Various estimators of the autoregressive model exist. We compare their performance in estimating the autocorrelation in short time series. In Study 1, under correct model specification, we compare the frequentist r 1 estimator, C-statistic, ordinary least squares estimator (OLS) and maximum likelihood estimator (MLE), and a Bayesian method, considering flat (B f ) and symmetrized reference (B sr ) priors. In a completely crossed experimental design we vary lengths of time series (i.e., T = 10, 25, 40, 50 and 100) and autocorrelation (from -0.90 to 0.90 with steps of 0.10). The results show a lowest bias for the B sr , and a lowest variability for r 1 . The power in different conditions is highest for B sr and OLS. For T = 10, the absolute performance of all measurements is poor, as expected. In Study 2, we study robustness of the methods through misspecification by generating the data according to an ARMA(1,1) model, but still analysing the data with an AR(1) model. We use the two methods with the lowest bias for this study, i.e., B sr and MLE. The bias gets larger when the non-modelled moving average parameter becomes larger. Both the variability and power show dependency on the non-modelled parameter. The differences between the two estimation methods are negligible for all measurements.
An analytical study for the design of advanced rotor airfoils

NASA Technical Reports Server (NTRS)

Kemp, L. D.

1973-01-01

A theoretical study has been conducted to design and evaluate two airfoils for helicopter rotors. The best basic shape, designed with a transonic hodograph design method, was modified to meet subsonic criteria. One airfoil had an additional constraint for low pitching-moment at the transonic design point. Airfoil characteristics were predicted. Results of a comparative analysis of helicopter performance indicate that the new airfoils will produce reduced rotor power requirements compared to the NACA 0012. The hodograph design method, written in CDC Algol, is listed and described.

Meta-analysis of haplotype-association studies: comparison of methods and empirical evaluation of the literature

PubMed Central

2011-01-01

Background Meta-analysis is a popular methodology in several fields of medical research, including genetic association studies. However, the methods used for meta-analysis of association studies that report haplotypes have not been studied in detail. In this work, methods for performing meta-analysis of haplotype association studies are summarized, compared and presented in a unified framework along with an empirical evaluation of the literature. Results We present multivariate methods that use summary-based data as well as methods that use binary and count data in a generalized linear mixed model framework (logistic regression, multinomial regression and Poisson regression). The methods presented here avoid the inflation of the type I error rate that could be the result of the traditional approach of comparing a haplotype against the remaining ones, whereas, they can be fitted using standard software. Moreover, formal global tests are presented for assessing the statistical significance of the overall association. Although the methods presented here assume that the haplotypes are directly observed, they can be easily extended to allow for such an uncertainty by weighting the haplotypes by their probability. Conclusions An empirical evaluation of the published literature and a comparison against the meta-analyses that use single nucleotide polymorphisms, suggests that the studies reporting meta-analysis of haplotypes contain approximately half of the included studies and produce significant results twice more often. We show that this excess of statistically significant results, stems from the sub-optimal method of analysis used and, in approximately half of the cases, the statistical significance is refuted if the data are properly re-analyzed. Illustrative examples of code are given in Stata and it is anticipated that the methods developed in this work will be widely applied in the meta-analysis of haplotype association studies. PMID:21247440
Do sampling methods differ in their utility for ecological monitoring? Comparison of line-point intercept, grid-point intercept, and ocular estimate methods

USDA-ARS?s Scientific Manuscript database

This study compared the utility of three sampling methods for ecological monitoring based on: interchangeability of data (rank correlations), precision (coefficient of variation), cost (minutes/transect), and potential of each method to generate multiple indicators. Species richness and foliar cover...
Performance of human fecal anaerobe-associated PCR-based assays in a multi-laboratory method evaluation study

EPA Science Inventory

A number of PCR-based methods for detecting human fecal material in environmental waters have been developed over the past decade, but these methods have rarely received independent comparative testing. Here, we evaluated ten of these methods (BacH, BacHum-UCD, B. thetaiotaomic...
Detailed Hydrographic Feature Extraction from High-Resolution LiDAR Data

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

Danny L. Anderson

Detailed hydrographic feature extraction from high-resolution light detection and ranging (LiDAR) data is investigated. Methods for quantitatively evaluating and comparing such extractions are presented, including the use of sinuosity and longitudinal root-mean-square-error (LRMSE). These metrics are then used to quantitatively compare stream networks in two studies. The first study examines the effect of raster cell size on watershed boundaries and stream networks delineated from LiDAR-derived digital elevation models (DEMs). The study confirmed that, with the greatly increased resolution of LiDAR data, smaller cell sizes generally yielded better stream network delineations, based on sinuosity and LRMSE. The second study demonstrates amore » new method of delineating a stream directly from LiDAR point clouds, without the intermediate step of deriving a DEM. Direct use of LiDAR point clouds could improve efficiency and accuracy of hydrographic feature extractions. The direct delineation method developed herein and termed “mDn”, is an extension of the D8 method that has been used for several decades with gridded raster data. The method divides the region around a starting point into sectors, using the LiDAR data points within each sector to determine an average slope, and selecting the sector with the greatest downward slope to determine the direction of flow. An mDn delineation was compared with a traditional grid-based delineation, using TauDEM, and other readily available, common stream data sets. Although, the TauDEM delineation yielded a sinuosity that more closely matches the reference, the mDn delineation yielded a sinuosity that was higher than either the TauDEM method or the existing published stream delineations. Furthermore, stream delineation using the mDn method yielded the smallest LRMSE.« less
Comparability and repeatability of three commonly used methods for measuring endurance capacity.

PubMed

Baxter-Gilbert, James; Mühlenhaupt, Max; Whiting, Martin J

2017-12-01

Measures of endurance (time to exhaustion) have been used to address a wide range of questions in ecomorphological and physiological research, as well as being used as a proxy for survival and fitness. Swimming, stationary (circular) track running, and treadmill running are all commonly used methods for measuring endurance. Despite the use of these methods across a broad range of taxa, how comparable these methods are to one another, and whether they are biologically relevant, is rarely examined. We used Australian water dragons (Intellagama lesueurii), a species that is morphologically adept at climbing, swimming, and running, to compare these three methods of endurance and examined if there is repeatability within and between trial methods. We found that time to exhaustion was not highly repeatable within a method, suggesting that single measures or a mean time to exhaustion across trials are not appropriate. Furthermore, we compared mean maximal endurance times among the three methods, and found that the two running methods (i.e., stationary track and treadmill) were similar, but swimming was distinctly different, resulting in lower mean maximal endurance times. Finally, an individual's endurance rank was not repeatable across methods, suggesting that the three endurance trial methods are not providing similar information about an individual's performance capacity. Overall, these results highlight the need to carefully match a measure of performance capacity with the study species and the research questions being asked so that the methods being used are behaviorally, ecologically, and physiologically relevant. © 2018 Wiley Periodicals, Inc.
The Effectiveness Of Social Media (Facebook) Compared With More Traditional Advertising Methods for Recruiting Eligible Participants To Health Research Studies: A Randomized, Controlled Clinical Trial

PubMed Central

Thow, Megan; Ferguson, Stuart G

2016-01-01

Background Recruiting participants for research studies can be difficult and costly. The popularity of social media platforms (eg, Facebook) has seen corresponding growth in the number of researchers turning to social networking sites and their embedded advertising frameworks to locate eligible participants for studies. Compared with traditional recruitment strategies such as print media, social media advertising has been shown to be favorable in terms of its reach (especially with hard-to-reach populations), cost effectiveness, and usability. However, to date, no studies have examined how participants recruited via social media progress through a study compared with those recruited using more traditional recruitment strategies. Objectives (1) Examine whether visiting the study website prior to being contacted by researchers creates self-screened participants who are more likely to progress through all study phases (eligible, enrolled, completed); (2) compare conversion percentages and cost effectiveness of each recruitment method at each study phase; and, (3) compare demographic and smoking characteristics of participants recruited through each strategy to determine if they attract similar samples. Methods Participants recruited to a smoking cessation clinical trial were grouped by how they had become aware of the study: via social media (Facebook) or traditional media (eg, newspaper, flyers, radio, word of mouth). Groups were compared based on throughput data (conversion percentages and cost) as well as demographic and smoking characteristics. Results Visiting the study website did not result in individuals who were more likely to be eligible for (P=.24), enroll in (P=.20), or complete (P=.25) the study. While using social media was more cost effective than traditional methods when we examined earlier endpoints of the recruitment process (cost to obtain a screened respondent: AUD $22.73 vs $29.35; cost to obtain an eligible respondent: $37.56 vs $44.77), it was less cost effective in later endpoints (cost per enrolled participant: $56.34 vs $52.33; cost per completed participant: $103.66 vs $80.43). Participants recruited via social media were more likely to be younger (P=.001) and less confident in their quit attempts (P=.004) compared to those recruited via traditional methods. Conclusions Our study suggests that while social media advertising may be effective in generating interest from potential participants, this strategy’s ability to attract conscientious recruits is more questionable. Researchers considering using online resources (eg, social media advertising, matrix codes) should consider including prescreening questions to promote conversion percentages. Ultimately, researchers seeking to maximize their recruitment budget should consider using a combination of advertising strategies. Trial Registration Australian New Zealand Clinical Trials Registry ACTRN 12614000329662; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=365947l (Archived by WebCite at http://www.webcitation.org/6jc6zXWZI) PMID:27511829
Theoretic derivation of directed acyclic subgraph algorithm and comparisons with message passing algorithm

NASA Astrophysics Data System (ADS)

Ha, Jeongmok; Jeong, Hong

2016-07-01

This study investigates the directed acyclic subgraph (DAS) algorithm, which is used to solve discrete labeling problems much more rapidly than other Markov-random-field-based inference methods but at a competitive accuracy. However, the mechanism by which the DAS algorithm simultaneously achieves competitive accuracy and fast execution speed, has not been elucidated by a theoretical derivation. We analyze the DAS algorithm by comparing it with a message passing algorithm. Graphical models, inference methods, and energy-minimization frameworks are compared between DAS and message passing algorithms. Moreover, the performances of DAS and other message passing methods [sum-product belief propagation (BP), max-product BP, and tree-reweighted message passing] are experimentally compared.
Comparing Interrater reliability between eye examination and eye self-examination 1

PubMed Central

de Lima, Maria Alzete; Pagliuca, Lorita Marlena Freitag; do Nascimento, Jennara Cândido; Caetano, Joselany Áfio

2017-01-01

Resume Objective: to compare Interrater reliability concerning two eye assessment methods. Method: quasi-experimental study conducted with 324 college students including eye self-examination and eye assessment performed by the researchers in a public university. Kappa coefficient was used to verify agreement. Results: reliability coefficients between Interraters ranged from 0.85 to 0.95, with statistical significance at 0.05. The exams to check for near acuity and peripheral vision presented a reasonable kappa >0.2. The remaining coefficients were higher, ranging from very to totally reliable. Conclusion: comparatively, the results of both methods were similar. The virtual manual on eye self-examination can be used to screen for eye conditions. PMID:29069269
Evaluation of VIDAS Salmonella (SLM) easy Salmonella method for the detection of Salmonella in a variety of foods: collaborative study.

PubMed

Crowley, Erin; Bird, Patrick; Fisher, Kiel; Goetz, Katherine; Benzinger, M Joseph; Agin, James; Goins, David; Johnson, Ronald L

2011-01-01

The VIDAS Salmonella (SLM) Easy Salmonella method is a specific enzyme-linked fluorescent immunoassay performed in the automated VIDAS instrument. The VIDAS Easy Salmonella method is a simple 2-step enrichment procedure, using pre-enrichment followed by selective enrichment in a newly formulated broth, SX2 broth. This new method was compared in a multilaboratory collaborative study to the U.S. Food and Drug Administration's Bacteriological Analytical Manual, Chapter 5 method for five food matrixes (liquid egg, vanilla ice cream, spinach, raw shrimp, and peanut butter) and the U.S. Department of Agriculture's Microbiology Laboratory Guidebook 4.04 method for deli turkey. Each food type was artificially contaminated with Salmonella at three inoculation levels. A total of 15 laboratories representing government, academia, and industry, throughout the United States, participated. In this study, 1583 samples were analyzed, of which 792 were paired replicates and 791 were unpaired replicates. Of the 792 paired replicates, 285 were positive by both the VIDAS and reference methods. Of the 791 unpaired replicates, 341 were positive by the VIDAS method and 325 were positive by the cultural reference method. A Chi-square analysis of each of the six food types was performed at the three inoculation levels tested. For all foods evaluated, the VIDAS Easy SLM method demonstrated results comparable to those of the reference methods for the detection of Salmonella.
Deliberate Self-Harm within an International Community Sample of Young People: Comparative Findings from the Child & Adolescent Self-Harm in Europe (CASE) Study

ERIC Educational Resources Information Center

Madge, Nicola; Hewitt, Anthea; Hawton, Keith; de Wilde, Erik Jan; Corcoran, Paul; Fekete, Sandor; van Heeringen, Kees; De Leo, Diego; Ystgaard, Mette

2008-01-01

Background: Deliberate self-harm among young people is an important focus of policy and practice internationally. Nonetheless, there is little reliable comparative international information on its extent or characteristics. We have conducted a seven-country comparative community study of deliberate self-harm among young people. Method: Over 30,000…
A Comparative Study of Performance in the Conners' Continuous Performance Test between Brazilian and North American Children

ERIC Educational Resources Information Center

Miranda, Monica Carolina; Sinnes, Elaine Girao; Pompeia, Sabine; Bueno, Orlando Francisco Amodeo

2008-01-01

Objective: The present study investigated the performance of Brazilian children in the Continuous Performance Test, CPT-II, and compared results to those of the norms obtained in the United States. Method: The U.S. norms were compared to those of a Brazilian sample composed of 6- to 11-year-olds separated into 4 age-groups (half boys) that…
Comparative study on the nutritional and antioxidant properties of two Mexican corn (Zea mays) based meals versus processed cereals.

PubMed

Sánchez-Herrera, Marissa; Martínez-Cano, Evelia; Maldonado-Santoyo, María; Aparicio-Fernández, Xochitl

2014-06-01

The present study was conducted to analyze the chemical composition, total phenolics content and antioxidant capacity of two whole corn (Zea mays) based meals traditional from Mexico: "traditional pinole" and "seven grain pinole"; and compare it with information available from ready to eat cereal products based on refined corn and whole grain cereals. Proximate analyses (moisture, ash, fat, protein and fiber) were carried out according to the procedures of AOAC, sugars content was determined by HPLC method; calcium and iron were quantified using atomic absorption spectroscopy. Total phenolic compounds were determined by Folin-Ciocalteu spectrophotometric method; the antiradical capacity was determined by DPPH colorimetric method and total antioxidant capacity was determined by FRAP method. Traditional and seven grain pinole presented higher energy content and nutrient density (protein and fat) than processed cereals. Calcium content was higher in processed cereals than pinole; seven grain pinole presented the highest conentration of iron. Polyphenolic concentration was higher in both kinds of pinole compared to processed cereals; traditional pinole presented the highest antioxidant activity measured by DPPH and FRAP methods. The results provide evidence about the important nutrient and antioxidant content of traditional and seven grain pinole compared to processed cereals based on corn and other grains. It is recommended their incorporation in to regular diet as a healthy food, with a good protein level, low sugar content and good antioxidant capacity.
Point-Connecting Measurements of the Hallux Valgus Deformity: A New Measurement and Its Clinical Application

PubMed Central

Seo, Jeong-Ho; Boedijono, Dimas

2016-01-01

Purpose The aim of this study was to investigate new point-connecting measurements for the hallux valgus angle (HVA) and the first intermetatarsal angle (IMA), which can reflect the degree of subluxation of the first metatarsophalangeal joint (MTPJ). Also, this study attempted to compare the validity of midline measurements and the new point-connecting measurements for the determination of HVA and IMA values. Materials and Methods Sixty feet of hallux valgus patients who underwent surgery between 2007 and 2011 were classified in terms of the severity of HVA, congruency of the first MTPJ, and type of chevron metatarsal osteotomy. On weight-bearing dorsal-plantar radiographs, HVA and IMA values were measured and compared preoperatively and postoperatively using both the conventional and new methods. Results Compared with midline measurements, point-connecting measurements showed higher inter- and intra-observer reliability for preoperative HVA/IMA and similar or higher inter- and intra-observer reliability for postoperative HVA/IMA. Patients who underwent distal chevron metatarsal osteotomy (DCMO) had higher intraclass correlation coefficient for inter- and intra-observer reliability for pre- and post-operative HVA and IMA measured by the point-connecting method compared with the midline method. All differences in the preoperative HVAs and IMAs determined by both the midline method and point-connecting methods were significant between the deviated group and subluxated groups (p=0.001). Conclusion The point-connecting method for measuring HVA and IMA in the subluxated first MTPJ may better reflect the severity of a HV deformity with higher reliability than the midline method, and is more useful in patients with DCMO than in patients with proximal chevron metatarsal osteotomy. PMID:26996576
The contribution of Raman spectroscopy to the analytical quality control of cytotoxic drugs in a hospital environment: eliminating the exposure risks for staff members and their work environment.

PubMed

Bourget, Philippe; Amin, Alexandre; Vidal, Fabrice; Merlette, Christophe; Troude, Pénélope; Baillet-Guffroy, Arlette

2014-08-15

The purpose of the study was to perform a comparative analysis of the technical performance, respective costs and environmental effect of two invasive analytical methods (HPLC and UV/visible-FTIR) as compared to a new non-invasive analytical technique (Raman spectroscopy). Three pharmacotherapeutic models were used to compare the analytical performances of the three analytical techniques. Statistical inter-method correlation analysis was performed using non-parametric correlation rank tests. The study's economic component combined calculations relative to the depreciation of the equipment and the estimated cost of an AQC unit of work. In any case, analytical validation parameters of the three techniques were satisfactory, and strong correlations between the two spectroscopic techniques vs. HPLC were found. In addition, Raman spectroscopy was found to be superior as compared to the other techniques for numerous key criteria including a complete safety for operators and their occupational environment, a non-invasive procedure, no need for consumables, and a low operating cost. Finally, Raman spectroscopy appears superior for technical, economic and environmental objectives, as compared with the other invasive analytical methods. Copyright © 2014 Elsevier B.V. All rights reserved.
Practice-based evidence study design for comparative effectiveness research.

PubMed

Horn, Susan D; Gassaway, Julie

2007-10-01

To describe a new, rigorous, comprehensive practice-based evidence for clinical practice improvement (PBE-CPI) study methodology, and compare its features, advantages, and disadvantages to those of randomized controlled trials and sophisticated statistical methods for comparative effectiveness research. PBE-CPI incorporates natural variation within data from routine clinical practice to determine what works, for whom, when, and at what cost. It uses the knowledge of front-line caregivers, who develop study questions and define variables as part of a transdisciplinary team. Its comprehensive measurement framework provides a basis for analyses of significant bivariate and multivariate associations between treatments and outcomes, controlling for patient differences, such as severity of illness. PBE-CPI studies can uncover better practices more quickly than randomized controlled trials or sophisticated statistical methods, while achieving many of the same advantages. We present examples of actionable findings from PBE-CPI studies in postacute care settings related to comparative effectiveness of medications, nutritional support approaches, incontinence products, physical therapy activities, and other services. Outcomes improved when practices associated with better outcomes in PBE-CPI analyses were adopted in practice.
Clinical efficacy of electronic apex locators: systematic review.

PubMed

Martins, Jorge N R; Marques, Duarte; Mata, António; Caramês, João

2014-06-01

Apical constriction has been proposed as the most appropriate apical limit for the endodontic working length. Despite being the most used, some limitations are attributed to the radiographic method of working length determination. It lacks precision because it is based on the average position of the apical constriction. The electronic apex locators have been presented as an alternative to the odontometry performed by radiography. These devices detect the transition of the pulp to the periodontal tissue, which is anatomically very close to the apical constriction and may perform with improved accuracy. A systematic review was performed to compare the radiographic and electronic methods. Clinical studies that compared both methods were searched for on 7 electronic databases, a manual search was performed on the bibliography of articles collected on the electronic databases, and the authors were contacted to ask for references of more research not detected on the electronic and manual search. Twenty-one articles were selected. The majority were comparative or evaluation studies, and very few clinical studies comparing both methods are available. Several methodological limitations are present on the collected articles and debated in this review. Although the available scientific evidence base is short and at considerable risk of bias, it is still possible to conclude that the apical locator reduces the patient radiation exposure and also that the electronic method may perform better on the working length determination. At least one radiographic control should be performed to detect possible errors of the electronic devices. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
Hemoglobin measured by Hemocue and a reference method in venous and capillary blood: a validation study.

PubMed

Neufeld, Lynnette; García-Guerra, Armando; Sánchez-Francia, Domingo; Newton-Sánchez, Oscar; Ramírez-Villalobos, María Dolores; Rivera-Dommarco, Juan

2002-01-01

To assess the comparability of hemoglobin concentration (Hb) in venous and capillary blood measured by Hemocue and an automated spectrophotometer (Celldyn) and to document the influence of type of blood (capillary or venous) and analysis method on anemia prevalence estimates. Between February and May 2000, capillary and venous samples were collected from 72 adults and children at Hospital del Niño Morelense (Morelos State Children's Hospital) in Cuernavaca, Morelos, Mexico, and assessed for Hb using the Hemocue and Celldyn methods. Estimated Hb levels were compared using the concordance correlation coefficient and Student's t test for paired data. The sensitivity and specificity for anemia diagnosis were estimated and compared between type of blood and method of assessment. Capillary blood had higher Hb (+0.5 g/dl) than venous blood in adults and children, as did samples assessed by Celldyn compared to Hemocue (+0.3 g/dl). Specificity to detect anemia was adequate (> 0.90) but sensitivity was low for capillary blood assessed by Hemocue (< 0.80). The difference in Hb between venous and capillary blood is likely related to biological variability. Hemoglobin concentration in capillary blood assessed by Hemocue provides an adequate estimation of population anemia prevalence but may result in excess false negative diagnoses among individuals. The results of this study stress the importance of sample collection technique, particularly for children. Method of analysis and sampling site need to be taken into consideration in field studies. The English version of this paper is available too at: http://www.insp.mx/salud/index.html.
A Comparison of Protein Extraction Methods Suitable for Gel-Based Proteomic Studies of Aphid Proteins

PubMed Central

Cilia, M.; Fish, T.; Yang, X.; Mclaughlin, M.; Thannhauser, T. W.

2009-01-01

Protein extraction methods can vary widely in reproducibility and in representation of the total proteome, yet there are limited data comparing protein isolation methods. The methodical comparison of protein isolation methods is the first critical step for proteomic studies. To address this, we compared three methods for isolation, purification, and solubilization of insect proteins. The aphid Schizaphis graminum, an agricultural pest, was the source of insect tissue. Proteins were extracted using TCA in acetone (TCA-acetone), phenol, or multi-detergents in a chaotrope solution. Extracted proteins were solubilized in a multiple chaotrope solution and examined using 1-D and 2-D electrophoresis and compared directly using 2-D Difference Gel Electrophoresis (2-D DIGE). Mass spectrometry was used to identify proteins from each extraction type. We were unable to ascribe the differences in the proteins extracted to particular physical characteristics, cell location, or biological function. The TCA-acetone extraction yielded the greatest amount of protein from aphid tissues. Each extraction method isolated a unique subset of the aphid proteome. The TCA-acetone method was explored further for its quantitative reliability using 2-D DIGE. Principal component analysis showed that little of the variation in the data was a result of technical issues, thus demonstrating that the TCA-acetone extraction is a reliable method for preparing aphid proteins for a quantitative proteomics experiment. These data suggest that although the TCA-acetone method is a suitable method for quantitative aphid proteomics, a combination of extraction approaches is recommended for increasing proteome coverage when using gel-based separation techniques. PMID:19721822
The Acquisition of Mathematics Pedagogical Content Knowledge in University Mathematics Education Courses: Results of a Mixed Methods Study on the Effectiveness of Teacher Education in Germany

ERIC Educational Resources Information Center

Buchholtz, Nils Frederik

2017-01-01

This paper reports on a longitudinal mixed methods evaluation study on the acquisition and development of mathematical pedagogical content knowledge (MPCK) of future teachers at several German universities. The study is a German supplementary study to the international comparative TEDS-M 2008 study. Besides the pedagogical content knowledge that…
A comparative study of amplitude calibrations for the East Asia VLBI Network: A priori and template spectrum methods

NASA Astrophysics Data System (ADS)

Cho, Ilje; Jung, Taehyun; Zhao, Guang-Yao; Akiyama, Kazunori; Sawada-Satoh, Satoko; Kino, Motoki; Byun, Do-Young; Sohn, Bong Won; Shibata, Katsunori M.; Hirota, Tomoya; Niinuma, Kotaro; Yonekura, Yoshinori; Fujisawa, Kenta; Oyama, Tomoaki

2017-12-01

We present the results of a comparative study of amplitude calibrations for the East Asia VLBI Network (EAVN) at 22 and 43 GHz using two different methods of an "a priori" and a "template spectrum", particularly on lower declination sources. Using observational data sets of early EAVN observations, we investigated the elevation-dependence of the gain values at seven stations of the KaVA (KVN and VERA Array) and three additional telescopes in Japan (Takahagi 32 m, Yamaguchi 32 m, and Nobeyama 45 m). By comparing the independently obtained gain values based on these two methods, we found that the gain values from each method were consistent within 10% at elevations higher than 10°. We also found that the total flux densities of two images produced from the different amplitude calibrations were in agreement within 10% at both 22 and 43 GHz. By using the template spectrum method, furthermore, the additional radio telescopes can participate in KaVA (i.e., EAVN), giving a notable sensitivity increase. Therefore, our results will constrain the detailed conditions in order to measure the VLBI amplitude reliably using EAVN, and discuss the potential of possible expansion to telescopes comprising EAVN.

[Research progress on the technique and materials for three-dimensional bio-printing].

PubMed

Yang, Runhuai; Chen, Yueming; Ma, Changwang; Wang, Huiqin; Wang, Shuyue

2017-04-01

Three-dimensional (3D) bio-printing is a novel engineering technique by which the cells and support materials can be manufactured to a complex 3D structure. Compared with other 3D printing methods, 3D bio-printing should pay more attention to the biocompatible environment of the printing methods and the materials. Aimed at studying the feature of the 3D bio-printing, this paper mainly focuses on the current research state of 3D bio-printing, with the techniques and materials of the bio-printing especially emphasized. To introduce current printing methods, the inkjet method, extrusion method, stereolithography skill and laser-assisted technique are described. The printing precision, process, requirements and influence of all the techniques on cell status are compared. For introduction of the printing materials, the cross-link, biocompatibility and applications of common bio-printing materials are reviewed and compared. Most of the 3D bio-printing studies are being remained at the experimental stage up to now, so the review of 3D bio-printing could improve this technique for practical use, and it could also contribute to the further development of 3D bio-printing.
The validation study on a three-dimensional burn estimation smart-phone application: accurate, free and fast?

PubMed

Cheah, A K W; Kangkorn, T; Tan, E H; Loo, M L; Chong, S J

2018-01-01

Accurate total body surface area burned (TBSAB) estimation is a crucial aspect of early burn management. It helps guide resuscitation and is essential in the calculation of fluid requirements. Conventional methods of estimation can often lead to large discrepancies in burn percentage estimation. We aim to compare a new method of TBSAB estimation using a three-dimensional smart-phone application named 3D Burn Resuscitation (3D Burn) against conventional methods of estimation-Rule of Palm, Rule of Nines and the Lund and Browder chart. Three volunteer subjects were moulaged with simulated burn injuries of 25%, 30% and 35% total body surface area (TBSA), respectively. Various healthcare workers were invited to use both the 3D Burn application as well as the conventional methods stated above to estimate the volunteer subjects' burn percentages. Collective relative estimations across the groups showed that when used, the Rule of Palm, Rule of Nines and the Lund and Browder chart all over-estimated burns area by an average of 10.6%, 19.7%, and 8.3% TBSA, respectively, while the 3D Burn application under-estimated burns by an average of 1.9%. There was a statistically significant difference between the 3D Burn application estimations versus all three other modalities ( p < 0.05). Time of using the application was found to be significantly longer than traditional methods of estimation. The 3D Burn application, although slower, allowed more accurate TBSAB measurements when compared to conventional methods. The validation study has shown that the 3D Burn application is useful in improving the accuracy of TBSAB measurement. Further studies are warranted, and there are plans to repeat the above study in a different centre overseas as part of a multi-centre study, with a view of progressing to a prospective study that compares the accuracy of the 3D Burn application against conventional methods on actual burn patients.
A Comparative Study of Distribution System Parameter Estimation Methods

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

Sun, Yannan; Williams, Tess L.; Gourisetti, Sri Nikhil Gup

2016-07-17

In this paper, we compare two parameter estimation methods for distribution systems: residual sensitivity analysis and state-vector augmentation with a Kalman filter. These two methods were originally proposed for transmission systems, and are still the most commonly used methods for parameter estimation. Distribution systems have much lower measurement redundancy than transmission systems. Therefore, estimating parameters is much more difficult. To increase the robustness of parameter estimation, the two methods are applied with combined measurement snapshots (measurement sets taken at different points in time), so that the redundancy for computing the parameter values is increased. The advantages and disadvantages of bothmore » methods are discussed. The results of this paper show that state-vector augmentation is a better approach for parameter estimation in distribution systems. Simulation studies are done on a modified version of IEEE 13-Node Test Feeder with varying levels of measurement noise and non-zero error in the other system model parameters.« less
A Comparative Study of Strategic HRD Approaches for Workforce Planning in the Tourism Industry

ERIC Educational Resources Information Center

Bartlett, Kenneth; Johnson, Karen; Schneider, Ingrid E.

2006-01-01

This study compares the outcomes of two often used approaches for strategic HRD planning. Using methods framed within a strategic HRD planning framework the outcomes of a qualitative primary data approach are examined against quantitative labor market projections in a study of the future Minnesota tourism workforce. Results show each planning…
A Comparative Case Study of Developing Leaders through a Doctoral Program: A Study of One Academic Institution

ERIC Educational Resources Information Center

Scanlon, Sheryl Lynne

2012-01-01

The purpose of this comparative case study was to determine how one academic institution could address the leadership gap facing organizations today, through a traditional, classroom doctoral program in Organizational Leadership. Data was gathered utilizing mixed methods methodology that included a survey questionnaire, focus group information,…
Traditional Instruction versus Virtual Reality Simulation: A Comparative Study of Phlebotomy Training among Nursing Students in Kuwait

ERIC Educational Resources Information Center

William, Abeer; Vidal, Victoria L.; John, Pamela

2016-01-01

This quasi-experimental study compared differences in phlebotomy performance on a live client, between a control group taught through the traditional method and an experimental group using virtual reality simulation. The study showed both groups had performed successfully, using the following metrics: number of reinsertions, pain factor, hematoma…
Aggression in Dating Relationships Compared by Country of Origin

ERIC Educational Resources Information Center

Seligowski, Antonia; West, Doe

2009-01-01

Aims: The purpose of this study was to analyze prevalence levels of aggression in dating relationships and to compare this by country of origin. The study also seeks more understanding of the violence experienced by men in these countries. Method: A convenience sample was used; study participants were 194 females and 168 males ranging in age from…
Evaluation of three methods for the concentration of poliovirus from oysters.

PubMed

Bouchriti, N; Goyal, S M

1992-10-01

Three methods for the concentration of poliovirus from oyster homogenates were compared. The adsorption-elution-precipitation method gave the lowest average virus recovery (24.1%), while the beef extract elution-acid precipitation method and the non-fat dry milk elution-acid precipitation methods gave recoveries of 47.2% and 39.6%, respectively. Although the overall recovery rates with these methods were lower than those reported in previous studies, recoveries of 40-47% obtained with the elution-precipitation methods used in the present study are considered to be above average in terms of recovery efficiency.
Comprehensive comparative analysis of 5'-end RNA-sequencing methods.

PubMed

Adiconis, Xian; Haber, Adam L; Simmons, Sean K; Levy Moonshine, Ami; Ji, Zhe; Busby, Michele A; Shi, Xi; Jacques, Justin; Lancaster, Madeline A; Pan, Jen Q; Regev, Aviv; Levin, Joshua Z

2018-06-04

Specialized RNA-seq methods are required to identify the 5' ends of transcripts, which are critical for studies of gene regulation, but these methods have not been systematically benchmarked. We directly compared six such methods, including the performance of five methods on a single human cellular RNA sample and a new spike-in RNA assay that helps circumvent challenges resulting from uncertainties in annotation and RNA processing. We found that the 'cap analysis of gene expression' (CAGE) method performed best for mRNA and that most of its unannotated peaks were supported by evidence from other genomic methods. We applied CAGE to eight brain-related samples and determined sample-specific transcription start site (TSS) usage, as well as a transcriptome-wide shift in TSS usage between fetal and adult brain.
Comparison of Boiling and Robotics Automation Method in DNA Extraction for Metagenomic Sequencing of Human Oral Microbes.

PubMed

Yamagishi, Junya; Sato, Yukuto; Shinozaki, Natsuko; Ye, Bin; Tsuboi, Akito; Nagasaki, Masao; Yamashita, Riu

2016-01-01

The rapid improvement of next-generation sequencing performance now enables us to analyze huge sample sets with more than ten thousand specimens. However, DNA extraction can still be a limiting step in such metagenomic approaches. In this study, we analyzed human oral microbes to compare the performance of three DNA extraction methods: PowerSoil (a method widely used in this field), QIAsymphony (a robotics method), and a simple boiling method. Dental plaque was initially collected from three volunteers in the pilot study and then expanded to 12 volunteers in the follow-up study. Bacterial flora was estimated by sequencing the V4 region of 16S rRNA following species-level profiling. Our results indicate that the efficiency of PowerSoil and QIAsymphony was comparable to the boiling method. Therefore, the boiling method may be a promising alternative because of its simplicity, cost effectiveness, and short handling time. Moreover, this method was reliable for estimating bacterial species and could be used in the future to examine the correlation between oral flora and health status. Despite this, differences in the efficiency of DNA extraction for various bacterial species were observed among the three methods. Based on these findings, there is no "gold standard" for DNA extraction. In future, we suggest that the DNA extraction method should be selected on a case-by-case basis considering the aims and specimens of the study.
Mapping seagrass and colonized hard bottom in Springs Coast, Florida using WorldView-2 satellite imagery

NASA Astrophysics Data System (ADS)

Baumstark, René; Duffey, Renee; Pu, Ruiliang

2016-11-01

The offshore extent of seagrass habitat along the West Florida (USA) coast represents an important corridor for inshore-offshore migration of economically important fish and shellfish. Surviving at the fringe of light requirements, offshore seagrass beds are sensitive to changes in water clarity. Beyond and intermingled with the offshore seagrass areas are large swaths of colonized hard bottom. These offshore habitats of the West Florida coast have lacked mapping efforts needed for status and trends monitoring. The objective of this study was to propose an object-based classification method for mapping offshore habitats and to compare results to traditional photo-interpreted maps. Benthic maps were created from WorldView-2 satellite imagery using an Object Based Image Analysis (OBIA) method and a visual photo-interpretation method. A logistic regression analysis identified depth and distance from shore as significant parameters for discriminating spectrally similar seagrass and colonized hard bottom features. Seagrass, colonized hard bottom and unconsolidated sediment (sand) were mapped with 78% overall accuracy using the OBIA method compared to 71% overall accuracy using the photo-interpretation method. This study suggests an alternative for mapping deeper, offshore habitats capable of producing higher thematic and spatial resolution maps compared to those created with the traditional photo-interpretation method.
Comparative study of the ''Misgav Ladach'' and traditional Pfannenstiel surgical techniques for cesarean section.

PubMed

Belci, D; Kos, M; Zoricić, D; Kuharić, L; Slivar, A; Begić-Razem, E; Grdinić, I

2007-06-01

The aim of this study was to evaluate the advantages of the Misgav Ladach surgical technique compared to traditional cesarean section. A prospective randomized trial of 111 women undergoing cesarean section was carried out in the Pula General Hospital. Forty-nine operations were performed using the Pfannenstiel method of cesarean section, 55 by the Misgav Ladach method and 7 by lower midline laparotomy. It was proved that the cases where the Misgav Ladach method was implemented, compared to the Pfannenstiel method, showed a significantly shorter delivery/extraction and operative time (P=0.0009), the incision pain on the second postoperative day was significantly lower (0.021), we recorded a quicker stand up and walking time (P=0.013), significantly fewer analgesic injections and a shorter duration of analgesia were required (P=0.0009) and the bowel function was restored to normal sooner (P=0.001). The Misgav Ladach method of cesarean section has advantages over the Pfannenstiel method in so far as it is significantly quicker to perform, with diminished postoperative pain and less use of postoperative analgesics. The recovery of physiologic function is faster. No differences were found in intraoperative bleeding, maternal morbidity, scar appearance, uterus postoperative involution and the assessment of the inflammation response to the operative technique.
Micro-buffy coats of whole blood: a method for the electron microscopic study of mononuclear cells.

PubMed

Nunes, J F; Soares, J O; Alves de Matos, A P

1979-09-01

A method for the electron microscopic study of human peripheral lymphocytes by which very small buffy coats are obtained through centrifugation of heparinized whole blood in glass or plastic microhematocrit tubes is presented. This method is time saving and efficient, yielding well preserved material and a comparatively large number of mononuclear cells (mainly lymphocytes) in each thin section.
Hearing and Seeing Tone through Color: An Efficacy Study of Web-Based, Multimodal Chinese Tone Perception Training

ERIC Educational Resources Information Center

Godfroid, Aline; Lin, Chin-Hsi; Ryu, Catherine

2017-01-01

Multimodal approaches have been shown to be effective for many learning tasks. In this study, we compared the effectiveness of five multimodal methods for second language (L2) Mandarin tone perception training: three single-cue methods (number, pitch contour, color) and two dual-cue methods (color and number, color and pitch contour). A total of…
Robust sleep quality quantification method for a personal handheld device.

PubMed

Shin, Hangsik; Choi, Byunghun; Kim, Doyoon; Cho, Jaegeol

2014-06-01

The purpose of this study was to develop and validate a novel method for sleep quality quantification using personal handheld devices. The proposed method used 3- or 6-axes signals, including acceleration and angular velocity, obtained from built-in sensors in a smartphone and applied a real-time wavelet denoising technique to minimize the nonstationary noise. Sleep or wake status was decided on each axis, and the totals were finally summed to calculate sleep efficiency (SE), regarded as sleep quality in general. The sleep experiment was carried out for performance evaluation of the proposed method, and 14 subjects participated. An experimental protocol was designed for comparative analysis. The activity during sleep was recorded not only by the proposed method but also by well-known commercial applications simultaneously; moreover, activity was recorded on different mattresses and locations to verify the reliability in practical use. Every calculated SE was compared with the SE of a clinically certified medical device, the Philips (Amsterdam, The Netherlands) Actiwatch. In these experiments, the proposed method proved its reliability in quantifying sleep quality. Compared with the Actiwatch, accuracy and average bias error of SE calculated by the proposed method were 96.50% and -1.91%, respectively. The proposed method was vastly superior to other comparative applications with at least 11.41% in average accuracy and at least 6.10% in average bias; average accuracy and average absolute bias error of comparative applications were 76.33% and 17.52%, respectively.
Fine-resolution repeat topographic surveying of dryland landscapes using UAS-based structure-from-motion photogrammetry: Assessing accuracy and precision against traditional ground-based erosion measurements

USGS Publications Warehouse

Gillian, Jeffrey K.; Karl, Jason W.; Elaksher, Ahmed; Duniway, Michael C.

2017-01-01

Structure-from-motion (SfM) photogrammetry from unmanned aerial system (UAS) imagery is an emerging tool for repeat topographic surveying of dryland erosion. These methods are particularly appealing due to the ability to cover large landscapes compared to field methods and at reduced costs and finer spatial resolution compared to airborne laser scanning. Accuracy and precision of high-resolution digital terrain models (DTMs) derived from UAS imagery have been explored in many studies, typically by comparing image coordinates to surveyed check points or LiDAR datasets. In addition to traditional check points, this study compared 5 cm resolution DTMs derived from fixed-wing UAS imagery with a traditional ground-based method of measuring soil surface change called erosion bridges. We assessed accuracy by comparing the elevation values between DTMs and erosion bridges along thirty topographic transects each 6.1 m long. Comparisons occurred at two points in time (June 2014, February 2015) which enabled us to assess vertical accuracy with 3314 data points and vertical precision (i.e., repeatability) with 1657 data points. We found strong vertical agreement (accuracy) between the methods (RMSE 2.9 and 3.2 cm in June 2014 and February 2015, respectively) and high vertical precision for the DTMs (RMSE 2.8 cm). Our results from comparing SfM-generated DTMs to check points, and strong agreement with erosion bridge measurements suggests repeat UAS imagery and SfM processing could replace erosion bridges for a more synoptic landscape assessment of shifting soil surfaces for some studies. However, while collecting the UAS imagery and generating the SfM DTMs for this study was faster than collecting erosion bridge measurements, technical challenges related to the need for ground control networks and image processing requirements must be addressed before this technique could be applied effectively to large landscapes.
Sales Simulation Games: Student and Instructor Perceptions

ERIC Educational Resources Information Center

Beuk, Frederik

2016-01-01

This study combines the perspective of students (n = 137) and sales instructors (n = 248). It compares how well selling and sales management simulation games, case discussions, and traditional lectures are perceived to conform to the seven principles for good practice in undergraduate education. The study further compares each method's performance…
The Effectiveness of Problem-Based Instruction: A Comparative Study of Instructional Methods and Student Characteristics

ERIC Educational Resources Information Center

Mergendoller, John R.; Maxwell, Nan L.; Bellisimo, Yolanda

2006-01-01

This study compared the effectiveness of problem-based learning (PBL) and traditional instructional approaches in developing high-school students' macroeconomics knowledge and examined whether PBL was differentially effective with students demonstrating different levels of four aptitudes: verbal ability, interest in economics, preference for group…
Anxiety and Charles Bonnet Syndrome

ERIC Educational Resources Information Center

Geueke, Anna; Morley, Michael G.; Morley, Katharine; Lorch, Alice; Jackson, MaryLou; Lambrou, Angeliki; Wenberg, June; Oteng-Amoako, Afua

2012-01-01

Introduction: Some persons with Charles Bonnet syndrome (CBS) suffer significant anxiety because of their visual hallucinations, while others do not. The aim of the study presented here was to compare levels of anxiety in persons with low vision with and without CBS. Methods: This retrospective study compared the level of anxiety in 31 persons…
A PILOT STUDY TO COMPARE MICROBIAL AND CHEMICAL INDICATORS OF HUMAN FECAL CONTAMINATION IN WATER

EPA Science Inventory

Limitations exist in applying traditional microbial methods for the detection of human fecal contamination of water. A pilot study was undertaken to compare the microbial and chemical indicators of human fecal contamination of water. Sixty-four water samples were collected in O...

Collecting Student Feedback: A Comparison of Questionnaire and Other Methods

ERIC Educational Resources Information Center

Huxham, Mark; Laybourn, Phyllis; Cairncross, Sandra; Gray, Morag; Brown, Norrie; Goldfinch, Judy; Earl, Shirley

2008-01-01

A study was conducted comparing the feedback received from students about teaching obtained using different instruments. Twelve first- and second-year undergraduate modules were selected from seven different schools within a single university. Students studying each module were allocated to "questionnaire" and "comparator" groups. "Questionnaire"…
The SAVRY Improves Prediction of Reoffending: A Naturalistic Longitudinal Comparative Study

ERIC Educational Resources Information Center

Åström, Therese; Gumpert, Clara Hellner; Andershed, Anna-Karin; Forster, Martin

2017-01-01

Purpose: This study investigated the utility of the risk assessment "Structured Assessment of Violence Risk in Youth" (SAVRY) within the social services in Stockholm County, Sweden. Method: SAVRY assessments of 56 adolescents were compared to assessments guided by another instrument (Adolescent Drug Abuse Diagnosis [ADAD]; n = 38) and…
[The role of international comparison in surveying divorce trends].

PubMed

Cseh-szombathy, L

1982-04-01

In this study, the main survey methods and approaches to analyzing data on divorce in different countries are described. Some problems concerning the international comparability of divorce statistics are examined, and the value of international comparative studies for identifying common factors affecting divorce is stressed. (summary in ENG, RUS)
Socially Responsible Knowledge and Behaviors: Comparing Upper vs. Lower Classmen

ERIC Educational Resources Information Center

Kozar, Joy M.; Connell, Kim Y. Hiller

2010-01-01

Utilizing a sample of undergraduate students and survey research methods, this study examined knowledge on issues of social responsibility within the apparel and textiles industry, comparing the sophistication among upper- versus lower-classmen. The study also investigated the differences between students in their socially responsible apparel…
A scale-invariant change detection method for land use/cover change research

NASA Astrophysics Data System (ADS)

Xing, Jin; Sieber, Renee; Caelli, Terrence

2018-07-01

Land Use/Cover Change (LUCC) detection relies increasingly on comparing remote sensing images with different spatial and spectral scales. Based on scale-invariant image analysis algorithms in computer vision, we propose a scale-invariant LUCC detection method to identify changes from scale heterogeneous images. This method is composed of an entropy-based spatial decomposition, two scale-invariant feature extraction methods, Maximally Stable Extremal Region (MSER) and Scale-Invariant Feature Transformation (SIFT) algorithms, a spatial regression voting method to integrate MSER and SIFT results, a Markov Random Field-based smoothing method, and a support vector machine classification method to assign LUCC labels. We test the scale invariance of our new method with a LUCC case study in Montreal, Canada, 2005-2012. We found that the scale-invariant LUCC detection method provides similar accuracy compared with the resampling-based approach but this method avoids the LUCC distortion incurred by resampling.
A field study of selected U.S. Geological Survey analytical methods for measuring pesticides in filtered stream water, June - September 2012

USGS Publications Warehouse

Martin, Jeffrey D.; Norman, Julia E.; Sandstrom, Mark W.; Rose, Claire E.

2017-09-06

U.S. Geological Survey monitoring programs extensively used two analytical methods, gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry, to measure pesticides in filtered water samples during 1992–2012. In October 2012, the monitoring programs began using direct aqueous-injection liquid chromatography tandem mass spectrometry as a new analytical method for pesticides. The change in analytical methods, however, has the potential to inadvertently introduce bias in analysis of datasets that span the change.A field study was designed to document performance of the new method in a variety of stream-water matrices and to quantify any potential changes in measurement bias or variability that could be attributed to changes in analytical methods. The goals of the field study were to (1) summarize performance (bias and variability of pesticide recovery) of the new method in a variety of stream-water matrices; (2) compare performance of the new method in laboratory blank water (laboratory reagent spikes) to that in a variety of stream-water matrices; (3) compare performance (analytical recovery) of the new method to that of the old methods in a variety of stream-water matrices; (4) compare pesticide detections and concentrations measured by the new method to those of the old methods in a variety of stream-water matrices; (5) compare contamination measured by field blank water samples in old and new methods; (6) summarize the variability of pesticide detections and concentrations measured by the new method in field duplicate water samples; and (7) identify matrix characteristics of environmental water samples that adversely influence the performance of the new method. Stream-water samples and a variety of field quality-control samples were collected at 48 sites in the U.S. Geological Survey monitoring networks during June–September 2012. Stream sites were located across the United States and included sites in agricultural and urban land-use settings, as well as sites on major rivers.The results of the field study identified several challenges for the analysis and interpretation of data analyzed by both old and new methods, particularly when data span the change in methods and are combined for analysis of temporal trends in water quality. The main challenges identified are large (greater than 30 percent), statistically significant differences in analytical recovery, detection capability, and (or) measured concentrations for selected pesticides. These challenges are documented and discussed, but specific guidance or statistical methods to resolve these differences in methods are beyond the scope of the report. The results of the field study indicate that the implications of the change in analytical methods must be assessed individually for each pesticide and method.Understanding the possible causes of the systematic differences in concentrations between methods that remain after recovery adjustment might be necessary to determine how to account for the differences in data analysis. Because recoveries for each method are independently determined from separate reference standards and spiking solutions, the differences might be due to an error in one of the reference standards or solutions or some other basic aspect of standard procedure in the analytical process. Further investigation of the possible causes is needed, which will lead to specific decisions on how to compensate for these differences in concentrations in data analysis. In the event that further investigations do not provide insight into the causes of systematic differences in concentrations between methods, the authors recommend continuing to collect and analyze paired environmental water samples by both old and new methods. This effort should be targeted to seasons, sites, and expected concentrations to supplement those concentrations already assessed and to compare the ongoing analytical recovery of old and new methods to those observed in the summer and fall of 2012.
Methods for the Joint Meta-Analysis of Multiple Tests

ERIC Educational Resources Information Center

Trikalinos, Thomas A.; Hoaglin, David C.; Small, Kevin M.; Terrin, Norma; Schmid, Christopher H.

2014-01-01

Existing methods for meta-analysis of diagnostic test accuracy focus primarily on a single index test. We propose models for the joint meta-analysis of studies comparing multiple index tests on the same participants in paired designs. These models respect the grouping of data by studies, account for the within-study correlation between the tests'…
Effect of Jigsaw I Technique on Achievement in Written Expression Skill

ERIC Educational Resources Information Center

Maden, Sedat

2011-01-01

This study aims to compare the effects of Jigsaw I technique from the cooperative learning methods and traditional teaching method on academic achievement and retrieval of Turkish teacher candidates in the matter of written expression. The sample of the study consists of 70 students studying at the Department of Turkish teaching in the academic…
On Narrative Method, Biography and Narrative Unities in the Study of Teaching.

ERIC Educational Resources Information Center

Connelly, F. Michael; Clandinin, D. Jean

This paper outlines a narrative method for the study of teaching which has as its principle feature the reconstruction of classroom meaning in terms of narrative unities in the lives of classroom participants. This purpose is achieved by comparatively outlining similarities and differences with closely associated lines of work. This study of…
Teaching with the Case Study Method to Promote Active Learning in a Small Molecule Crystallography Course for Chemistry Students

ERIC Educational Resources Information Center

Campbell, Michael G.; Powers, Tamara M.; Zheng, Shao-Liang

2016-01-01

Implementing the case study method in a practical X-ray crystallography course designed for graduate or upper-level undergraduate chemistry students is described. Compared with a traditional lecture format, assigning small groups of students to examine literature case studies encourages more active engagement with the course material and…
A Meta-Analytic Review of Studies of the Effectiveness of Small-Group Learning Methods on Statistics Achievement

ERIC Educational Resources Information Center

Kalaian, Sema A.; Kasim, Rafa M.

2014-01-01

This meta-analytic study focused on the quantitative integration and synthesis of the accumulated pedagogical research in undergraduate statistics education literature. These accumulated research studies compared the academic achievement of students who had been instructed using one of the various forms of small-group learning methods to those who…
Do Zoo Visitors Come to Learn? An Internationally Comparative, Mixed-Methods Study

ERIC Educational Resources Information Center

Roe, Katie; McConney, Andrew

2015-01-01

Zoo visitors go to see animals, but are they there to learn? This mixed-methods study examines visitor learning from both zoos' and visitors' perspectives using qualitative and quantitative data. Five hundred and forty zoo visitor interviews from nine case studies provide insight into visitor intentions, which indicate that the majority of…
Comparison of Parametric and Nonparametric Bootstrap Methods for Estimating Random Error in Equipercentile Equating

ERIC Educational Resources Information Center

Cui, Zhongmin; Kolen, Michael J.

2008-01-01

This article considers two methods of estimating standard errors of equipercentile equating: the parametric bootstrap method and the nonparametric bootstrap method. Using a simulation study, these two methods are compared under three sample sizes (300, 1,000, and 3,000), for two test content areas (the Iowa Tests of Basic Skills Maps and Diagrams…
Inventory control of raw material using silver meal heuristic method in PR. Trubus Alami Malang

NASA Astrophysics Data System (ADS)

Ikasari, D. M.; Lestari, E. R.; Prastya, E.

2018-03-01

The purpose of this study was to compare the total inventory cost calculated using the method applied by PR. Trubus Alami and Silver Meal Heuristic (SMH) method. The study was started by forecasting the cigarette demand from July 2016 to June 2017 (48 weeks) using additive decomposition forecasting method. The additive decomposition was used because it has the lowest value of Mean Abosolute Deviation (MAD) and Mean Squared Deviation (MSD) compared to other methods such as multiplicative decomposition, moving average, single exponential smoothing, and double exponential smoothing. The forcasting results was then converted as a raw material needs and further calculated using SMH method to obtain inventory cost. As expected, the result shows that the order frequency of using SMH methods was smaller than that of using the method applied by Trubus Alami. This affected the total inventory cost. The result suggests that using SMH method gave a 29.41% lower inventory cost, giving the cost different of IDR 21,290,622. The findings, is therefore, indicated that the PR. Trubus Alami should apply the SMH method if the company wants to reduce the total inventory cost.
A comparative study of novel spectrophotometric methods based on isosbestic points; application on a pharmaceutical ternary mixture

NASA Astrophysics Data System (ADS)

Lotfy, Hayam M.; Saleh, Sarah S.; Hassan, Nagiba Y.; Salem, Hesham

This work represents the application of the isosbestic points present in different absorption spectra. Three novel spectrophotometric methods were developed, the first method is the absorption subtraction method (AS) utilizing the isosbestic point in zero-order absorption spectra; the second method is the amplitude modulation method (AM) utilizing the isosbestic point in ratio spectra; and third method is the amplitude summation method (A-Sum) utilizing the isosbestic point in derivative spectra. The three methods were applied for the analysis of the ternary mixture of chloramphenicol (CHL), dexamethasone sodium phosphate (DXM) and tetryzoline hydrochloride (TZH) in eye drops in the presence of benzalkonium chloride as a preservative. The components at the isosbestic point were determined using the corresponding unified regression equation at this point with no need for a complementary method. The obtained results were statistically compared to each other and to that of the developed PLS model. The specificity of the developed methods was investigated by analyzing laboratory prepared mixtures and the combined dosage form. The methods were validated as per ICH guidelines where accuracy, repeatability, inter-day precision and robustness were found to be within the acceptable limits. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed.
Matching-adjusted indirect comparison of efficacy in patients with moderate-to-severe plaque psoriasis treated with ixekizumab vs. secukinumab.

PubMed

Warren, R B; Brnabic, A; Saure, D; Langley, R G; See, K; Wu, J J; Schacht, A; Mallbris, L; Nast, A

2018-05-01

Head-to-head randomized studies comparing ixekizumab and secukinumab in the treatment of psoriasis are not available. To assess efficacy and quality of life using matching-adjusted indirect comparisons for treatment with ixekizumab vs. secukinumab. Psoriasis Area and Severity Index (PASI) improvement of at least 75%, 90% and 100% and Dermatology Life Quality Index (DLQI) 0/1 response rates for approved dosages of ixekizumab (160 mg at Week 0, then 80 mg every two weeks for the first 12 weeks) and secukinumab (300 mg at Weeks 0, 1, 2, 3 and 4, then 300 mg every 4 weeks) treatment were compared using data from active (etanercept and ustekinumab) and placebo-controlled studies. Comparisons were made using the Bucher (BU) method and two modified versions of the Signorovitch (SG) method (SG total and SG separate). Subsequently, results based on active treatment common comparators were combined using generic inverse-variance meta-analysis. In the meta-analysis of studies with active comparators, PASI 90 response rates were 12·7% [95% confidence interval (CI) 5·5-19·8, P = 0·0005], 10·0% (95% CI 2·1-18·0, P = 0·01) and 11·2% (95% CI 3·2-19·1, P = 0·006) higher and PASI 100 response rates were 11·7% (95% CI 5·9-17·5, P < 0·001), 12·7% (95% CI 6·0-19·4, P < 0·001) and 13·1% (95% CI 6·3-19·9, P < 0·001) higher for ixekizumab compared with secukinumab using BU, SG total and SG separate methods. PASI 75 results were comparable when SG methods were used and favoured ixekizumab when the BU method was used. Week 12 DLQI 0/1 response rates did not differ significantly. Ixekizumab had higher PASI 90 and PASI 100 responses at week 12 compared with secukinumab using adjusted indirect comparisons. © 2017 The Authors. British Journal of Dermatology published by John Wiley & Sons Ltd on behalf of British Association of Dermatologists.
A general probabilistic model for group independent component analysis and its estimation methods

PubMed Central

Guo, Ying

2012-01-01

SUMMARY Independent component analysis (ICA) has become an important tool for analyzing data from functional magnetic resonance imaging (fMRI) studies. ICA has been successfully applied to single-subject fMRI data. The extension of ICA to group inferences in neuroimaging studies, however, is challenging due to the unavailability of a pre-specified group design matrix and the uncertainty in between-subjects variability in fMRI data. We present a general probabilistic ICA (PICA) model that can accommodate varying group structures of multi-subject spatio-temporal processes. An advantage of the proposed model is that it can flexibly model various types of group structures in different underlying neural source signals and under different experimental conditions in fMRI studies. A maximum likelihood method is used for estimating this general group ICA model. We propose two EM algorithms to obtain the ML estimates. The first method is an exact EM algorithm which provides an exact E-step and an explicit noniterative M-step. The second method is an variational approximation EM algorithm which is computationally more efficient than the exact EM. In simulation studies, we first compare the performance of the proposed general group PICA model and the existing probabilistic group ICA approach. We then compare the two proposed EM algorithms and show the variational approximation EM achieves comparable accuracy to the exact EM with significantly less computation time. An fMRI data example is used to illustrate application of the proposed methods. PMID:21517789
A comparative study of physico-chemical properties of CBD and SILAR grown ZnO thin films

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

Jambure, S.B.; Patil, S.J.; Deshpande, A.R.

2014-01-01

Graphical abstract: Schematic model indicating ZnO nanorods by CBD (Z{sub 1}) and nanograins by SILAR (Z{sub 2}). - Highlights: • Simple methods for the synthesis of ZnO thin films. • Comparative study of physico-chemical properties of ZnO thin films prepared by CBD and SILAR methods. • CBD outperforms SILAR method. - Abstract: In the present work, nanocrystalline zinc oxide (ZnO) thin films have been successfully deposited onto glass substrates by simple and economical chemical bath deposition (CBD) and successive ionic layer adsorption reaction (SILAR) methods. These films were further characterized for their structural, optical, surface morphological and wettability properties. Themore » X-ray diffraction (XRD) patterns for both CBD and SILAR deposited ZnO thin films reveal the highly crystalline hexagonal wurtzite structure. From optical studies, band gaps obtained are 2.9 and 3.0 eV for CBD and SILAR deposited thin films, respectively. The scanning electron microscope (SEM) patterns show growth of well defined randomly oriented nanorods and nanograins on the CBD and SILAR deposited samples, respectively. The resistivity of CBD deposited films (10{sup 2} Ω cm) is lower than that of SILAR deposited films (10{sup 5} Ω cm). Surface wettability studies show hydrophobic nature for both films. From the above results it can be concluded that CBD grown ZnO thin films show better properties as compared to SILAR method.« less
Portfolio Development as a Three-Semester Process: The Value of Sequential Experience.

ERIC Educational Resources Information Center

Senne, Terry A.

This study examined nine cohort teacher candidates from each of two physical education teacher education (PETE) programs developed teaching portfolios in three consecutive semesters of comparable courses: (1) elementary methods; (2) secondary methods; and (3) the student teaching internship. Studied were changes over time in teacher candidate…
Combined Teaching Method: An Experimental Study

ERIC Educational Resources Information Center

Kolesnikova, Iryna V.

2016-01-01

The search for the best approach to business education has led educators and researchers to seek many different teaching strategies, ranging from the traditional teaching methods to various experimental approaches such as active learning techniques. The aim of this experimental study was to compare the effects of the traditional and combined…

Changes in Patterns of Teacher Interaction in Primary Classrooms: 1976-96.

ERIC Educational Resources Information Center

Galton, Maurice; Hargreaves, Linda; Comber, Chris; Wall, Debbie; Pell, Tony

1999-01-01

Addresses the effectiveness of teaching methods in English primary school classrooms. Evaluates the interventions designed to change primary educators' teaching methods by replicating the Observational Research and Classroom Learning Evaluation (ORACLE) study that was originally conducted in 1976. Compares the results from the original study to…
Teaching/Learning Methods and Students' Classification of Food Items

ERIC Educational Resources Information Center

Hamilton-Ekeke, Joy-Telu; Thomas, Malcolm

2011-01-01

Purpose: This study aims to investigate the effectiveness of a teaching method (TLS (Teaching/Learning Sequence)) based on a social constructivist paradigm on students' conceptualisation of classification of food. Design/methodology/approach: The study compared the TLS model developed by the researcher based on the social constructivist paradigm…
Course Delivery: Keystones of Effective Special Education Teacher Preparation

ERIC Educational Resources Information Center

Vernon-Dotson, Lisa J.; Floyd, Loury O.; Dukes, Charles; Darling, Sharon M.

2014-01-01

In this review of the literature, the authors examined studies investigating course delivery methods for preparing special education teachers. Ultimately, 17 studies were reviewed using a constant comparative qualitative method of analysis. This analysis led to the emergence of five themes: (a) established needs, (b) effectiveness, (c) logistics,…
Effect of processing methods on the stability and nutritional profiles of navy bean-soybean emulsions

USDA-ARS?s Scientific Manuscript database

In this study, an innovative emulsion made from soybean and navy bean blends of different proportionalities was developed. In addition, two processing methods were evaluated: traditional cooking and jet-cooking. The physical attributes and storage stability were measured and compared. This study fou...
Hermite WENO limiting for multi-moment finite-volume methods using the ADER-DT time discretization for 1-D systems of conservation laws

DOE PAGES

Norman, Matthew R.

2014-11-24

New Hermite Weighted Essentially Non-Oscillatory (HWENO) interpolants are developed and investigated within the Multi-Moment Finite-Volume (MMFV) formulation using the ADER-DT time discretization. Whereas traditional WENO methods interpolate pointwise, function-based WENO methods explicitly form a non-oscillatory, high-order polynomial over the cell in question. This study chooses a function-based approach and details how fast convergence to optimal weights for smooth flow is ensured. Methods of sixth-, eighth-, and tenth-order accuracy are developed. We compare these against traditional single-moment WENO methods of fifth-, seventh-, ninth-, and eleventh-order accuracy to compare against more familiar methods from literature. The new HWENO methods improve upon existingmore » HWENO methods (1) by giving a better resolution of unreinforced contact discontinuities and (2) by only needing a single HWENO polynomial to update both the cell mean value and cell mean derivative. Test cases to validate and assess these methods include 1-D linear transport, the 1-D inviscid Burger's equation, and the 1-D inviscid Euler equations. Smooth and non-smooth flows are used for evaluation. These HWENO methods performed better than comparable literature-standard WENO methods for all regimes of discontinuity and smoothness in all tests herein. They exhibit improved optimal accuracy due to the use of derivatives, and they collapse to solutions similar to typical WENO methods when limiting is required. The study concludes that the new HWENO methods are robust and effective when used in the ADER-DT MMFV framework. Finally, these results are intended to demonstrate capability rather than exhaust all possible implementations.« less
Comparative Study of Hand-Sutured versus Circular Stapled Anastomosis for Gastrojejunostomy in Laparoscopy Assisted Distal Gastrectomy.

PubMed

Seo, Su Hyun; Kim, Ki Han; Kim, Min Chan; Choi, Hong Jo; Jung, Ghap Joong

2012-06-01

Mechanical stapler is regarded as a good alternative to the hand sewing technique, when used in gastric reconstruction. The circular stapling method has been widely applied to gastrectomy (open orlaparoscopic), for gastric cancer. We illustrated and compared the hand-sutured method to the circular stapling method, for Billroth-II, in patients who underwent laparoscopy assisted distal gastrectomy for gastric cancer. Between April 2009 and May 2011, 60 patients who underwent laparoscopy assisted distal gastrectomy, with Billroth-II, were enrolled. Hand-sutured Billroth-II was performed in 40 patients (manual group) and circular stapler Billroth-II was performed in 20 patients (stapler group). Clinicopathological features and post-operative outcomes were evaluated and compared between the two groups. Nosignificant differences were observed in clinicopathologic parameters and post-operative outcomes, except in the operation times. Operation times and anastomosis times were significantly shorter in the stapler group (P=0.004 and P<0.001). Compared to the hand-sutured method, the circular stapling method can be applied safely and more efficiently, when performing Billroth-II anastomosis, after laparoscopy assisted distal gastrectomy in patients with gastric cancer.
Comparability of river suspended-sediment sampling and laboratory analysis methods

USGS Publications Warehouse

Groten, Joel T.; Johnson, Gregory D.

2018-03-06

Accurate measurements of suspended sediment, a leading water-quality impairment in many Minnesota rivers, are important for managing and protecting water resources; however, water-quality standards for suspended sediment in Minnesota are based on grab field sampling and total suspended solids (TSS) laboratory analysis methods that have underrepresented concentrations of suspended sediment in rivers compared to U.S. Geological Survey equal-width-increment or equal-discharge-increment (EWDI) field sampling and suspended sediment concentration (SSC) laboratory analysis methods. Because of this underrepresentation, the U.S. Geological Survey, in collaboration with the Minnesota Pollution Control Agency, collected concurrent grab and EWDI samples at eight sites to compare results obtained using different combinations of field sampling and laboratory analysis methods.Study results determined that grab field sampling and TSS laboratory analysis results were biased substantially low compared to EWDI sampling and SSC laboratory analysis results, respectively. Differences in both field sampling and laboratory analysis methods caused grab and TSS methods to be biased substantially low. The difference in laboratory analysis methods was slightly greater than field sampling methods.Sand-sized particles had a strong effect on the comparability of the field sampling and laboratory analysis methods. These results indicated that grab field sampling and TSS laboratory analysis methods fail to capture most of the sand being transported by the stream. The results indicate there is less of a difference among samples collected with grab field sampling and analyzed for TSS and concentration of fines in SSC. Even though differences are present, the presence of strong correlations between SSC and TSS concentrations provides the opportunity to develop site specific relations to address transport processes not captured by grab field sampling and TSS laboratory analysis methods.
Measurement and interpretation of skin prick test results.

PubMed

van der Valk, J P M; Gerth van Wijk, R; Hoorn, E; Groenendijk, L; Groenendijk, I M; de Jong, N W

2015-01-01

There are several methods to read skin prick test results in type-I allergy testing. A commonly used method is to characterize the wheal size by its 'average diameter'. A more accurate method is to scan the area of the wheal to calculate the actual size. In both methods, skin prick test (SPT) results can be corrected for histamine-sensitivity of the skin by dividing the results of the allergic reaction by the histamine control. The objectives of this study are to compare different techniques of quantifying SPT results, to determine a cut-off value for a positive SPT for histamine equivalent prick -index (HEP) area, and to study the accuracy of predicting cashew nut reactions in double-blind placebo-controlled food challenge (DBPCFC) tests with the different SPT methods. Data of 172 children with cashew nut sensitisation were used for the analysis. All patients underwent a DBPCFC with cashew nut. Per patient, the average diameter and scanned area of the wheal size were recorded. In addition, the same data for the histamine-induced wheal were collected for each patient. The accuracy in predicting the outcome of the DBPCFC using four different SPT readings (i.e. average diameter, area, HEP-index diameter, HEP-index area) were compared in a Receiver-Operating Characteristic (ROC) plot. Characterizing the wheal size by the average diameter method is inaccurate compared to scanning method. A wheal average diameter of 3 mm is generally considered as a positive SPT cut-off value and an equivalent HEP-index area cut-off value of 0.4 was calculated. The four SPT methods yielded a comparable area under the curve (AUC) of 0.84, 0.85, 0.83 and 0.83, respectively. The four methods showed comparable accuracy in predicting cashew nut reactions in a DBPCFC. The 'scanned area method' is theoretically more accurate in determining the wheal area than the 'average diameter method' and is recommended in academic research. A HEP-index area of 0.4 is determined as cut-off value for a positive SPT. However, in clinical practice, the 'average diameter method' is also useful, because this method provides similar accuracy in predicting cashew nut allergic reactions in the DBPCFC. Trial number NTR3572.
Preferences for partner notification method: variation in responses between respondents as index patients and contacts.

PubMed

Apoola, A; Radcliffe, K W; Das, S; Robshaw, V; Gilleran, G; Kumari, B S; Boothby, M; Rajakumar, R

2007-07-01

There have been very few studies focusing on what form of communication patients would find acceptable from a clinic. This study looks at the differences in preferences for various partner notification methods when the respondents were index patients compared with when they had to be contacted because a partner had a sexually transmitted infection (STI). There were 2544 respondents. When the clinic had to notify partners, respondents were more likely to report the method as good when a partner had an STI and they were being contacted compared with when the respondents had an infection and the partner was being contacted. The opposite was true for patient referral partner notification. Therefore, there are variations in the preferences of respondents for partner notification method, which depend on whether they see themselves as index patients or contacts.
Improving prokaryotic transposable elements identification using a combination of de novo and profile HMM methods.

PubMed

Kamoun, Choumouss; Payen, Thibaut; Hua-Van, Aurélie; Filée, Jonathan

2013-10-11

Insertion Sequences (ISs) and their non-autonomous derivatives (MITEs) are important components of prokaryotic genomes inducing duplication, deletion, rearrangement or lateral gene transfers. Although ISs and MITEs are relatively simple and basic genetic elements, their detection remains a difficult task due to their remarkable sequence diversity. With the advent of high-throughput genome and metagenome sequencing technologies, the development of fast, reliable and sensitive methods of ISs and MITEs detection become an important challenge. So far, almost all studies dealing with prokaryotic transposons have used classical BLAST-based detection methods against reference libraries. Here we introduce alternative methods of detection either taking advantages of the structural properties of the elements (de novo methods) or using an additional library-based method using profile HMM searches. In this study, we have developed three different work flows dedicated to ISs and MITEs detection: the first two use de novo methods detecting either repeated sequences or presence of Inverted Repeats; the third one use 28 in-house transposase alignment profiles with HMM search methods. We have compared the respective performances of each method using a reference dataset of 30 archaeal and 30 bacterial genomes in addition to simulated and real metagenomes. Compared to a BLAST-based method using ISFinder as library, de novo methods significantly improve ISs and MITEs detection. For example, in the 30 archaeal genomes, we discovered 30 new elements (+20%) in addition to the 141 multi-copies elements already detected by the BLAST approach. Many of the new elements correspond to ISs belonging to unknown or highly divergent families. The total number of MITEs has even doubled with the discovery of elements displaying very limited sequence similarities with their respective autonomous partners (mainly in the Inverted Repeats of the elements). Concerning metagenomes, with the exception of short reads data (<300 bp) for which both techniques seem equally limited, profile HMM searches considerably ameliorate the detection of transposase encoding genes (up to +50%) generating low level of false positives compare to BLAST-based methods. Compared to classical BLAST-based methods, the sensitivity of de novo and profile HMM methods developed in this study allow a better and more reliable detection of transposons in prokaryotic genomes and metagenomes. We believed that future studies implying ISs and MITEs identification in genomic data should combine at least one de novo and one library-based method, with optimal results obtained by running the two de novo methods in addition to a library-based search. For metagenomic data, profile HMM search should be favored, a BLAST-based step is only useful to the final annotation into groups and families.
Comparative study of some robust statistical methods: weighted, parametric, and nonparametric linear regression of HPLC convoluted peak responses using internal standard method in drug bioavailability studies.

PubMed

Korany, Mohamed A; Maher, Hadir M; Galal, Shereen M; Ragab, Marwa A A

2013-05-01

This manuscript discusses the application and the comparison between three statistical regression methods for handling data: parametric, nonparametric, and weighted regression (WR). These data were obtained from different chemometric methods applied to the high-performance liquid chromatography response data using the internal standard method. This was performed on a model drug Acyclovir which was analyzed in human plasma with the use of ganciclovir as internal standard. In vivo study was also performed. Derivative treatment of chromatographic response ratio data was followed by convolution of the resulting derivative curves using 8-points sin x i polynomials (discrete Fourier functions). This work studies and also compares the application of WR method and Theil's method, a nonparametric regression (NPR) method with the least squares parametric regression (LSPR) method, which is considered the de facto standard method used for regression. When the assumption of homoscedasticity is not met for analytical data, a simple and effective way to counteract the great influence of the high concentrations on the fitted regression line is to use WR method. WR was found to be superior to the method of LSPR as the former assumes that the y-direction error in the calibration curve will increase as x increases. Theil's NPR method was also found to be superior to the method of LSPR as the former assumes that errors could occur in both x- and y-directions and that might not be normally distributed. Most of the results showed a significant improvement in the precision and accuracy on applying WR and NPR methods relative to LSPR.
Modified Right Heart Contrast Echocardiography Versus Traditional Method in Diagnosis of Right-to-Left Shunt: A Comparative Study.

PubMed

Wang, Yi; Zeng, Jie; Yin, Lixue; Zhang, Mei; Hou, Dailun

2016-01-01

The purpose of this study was to evaluate the reliability, effectiveness, and safety of modified right heart contrast transthoracic echocardiography (cTTE) in comparison with the traditional method. We performed a modified right heart cTTE using saline mixed with a small sample of patient's own blood. Samples were agitated with varying intensity. This study protocol involved microscopic analysis and patient evaluation. 1. Microscopic analysis: After two contrast samples had been agitated 10 or 20 times, they underwent a comparison of bubble size, bubble number, and red blood cell morphology. 2. Patient analysis: 40 patients with suspected RLS (right- to-left shunt) were enrolled. All patients underwent right heart contrast echocardiography. Oxygen saturation, transit time and duration, presence of RLS, change in indirect bilirubin and urobilinogen concentrations were compared afterward. Modified method generated more bubbles (P<0.05), but the differences in bubble size were not significant (P>0.05). Twenty-four patients were diagnosed with RLS (60%) using the modified method compared to 16 patients (40%) with the traditional method. The transit time of ASb20 group was the shortest (P<0.05). However, the duration time in this group was much longer (P<0.05). Also, in semi-quantitative analysis mean rank of RLS was higher after injecting the modified contrast agent agitated 20 times (P<0.05). Modified right heart contrast echocardiography is a reliable, effective and safe method of detecting cardiovascular RLS.
Semiquantitative determination of mesophilic, aerobic microorganisms in cocoa products using the Soleris NF-TVC method.

PubMed

Montei, Carolyn; McDougal, Susan; Mozola, Mark; Rice, Jennifer

2014-01-01

The Soleris Non-fermenting Total Viable Count method was previously validated for a wide variety of food products, including cocoa powder. A matrix extension study was conducted to validate the method for use with cocoa butter and cocoa liquor. Test samples included naturally contaminated cocoa liquor and cocoa butter inoculated with natural microbial flora derived from cocoa liquor. A probability of detection statistical model was used to compare Soleris results at multiple test thresholds (dilutions) with aerobic plate counts determined using the AOAC Official Method 966.23 dilution plating method. Results of the two methods were not statistically different at any dilution level in any of the three trials conducted. The Soleris method offers the advantage of results within 24 h, compared to the 48 h required by standard dilution plating methods.
Numerical simulation of tunneling through arbitrary potential barriers applied on MIM and MIIM rectenna diodes

NASA Astrophysics Data System (ADS)

Abdolkader, Tarek M.; Shaker, Ahmed; Alahmadi, A. N. M.

2018-07-01

With the continuous miniaturization of electronic devices, quantum-mechanical effects such as tunneling become more effective in many device applications. In this paper, a numerical simulation tool is developed under a MATLAB environment to calculate the tunneling probability and current through an arbitrary potential barrier comparing three different numerical techniques: the finite difference method, transfer matrix method, and transmission line method. For benchmarking, the tool is applied to many case studies such as the rectangular single barrier, rectangular double barrier, and continuous bell-shaped potential barrier, each compared to analytical solutions and giving the dependence of the error on the number of mesh points. In addition, a thorough study of the J ‑ V characteristics of MIM and MIIM diodes, used as rectifiers for rectenna solar cells, is presented and simulations are compared to experimental results showing satisfactory agreement. On the undergraduate level, the tool provides a deeper insight for students to compare numerical techniques used to solve various tunneling problems and helps students to choose a suitable technique for a certain application.
Comments on Method in Comparative Higher Education.

ERIC Educational Resources Information Center

Wasser, Henry

The methodologies employed in comparative higher education and comparative education are briefly summarized and analyzed. Weaknesses of the following approaches used by scholars/researchers in the field are identified: (1) locating decision-making structures and relations in broadly differentiated aggregations of systems; (2) case study; (3)…
Comparison of Basic and Ensemble Data Mining Methods in Predicting 5-Year Survival of Colorectal Cancer Patients.

PubMed

Pourhoseingholi, Mohamad Amin; Kheirian, Sedigheh; Zali, Mohammad Reza

2017-12-01

Colorectal cancer (CRC) is one of the most common malignancies and cause of cancer mortality worldwide. Given the importance of predicting the survival of CRC patients and the growing use of data mining methods, this study aims to compare the performance of models for predicting 5-year survival of CRC patients using variety of basic and ensemble data mining methods. The CRC dataset from The Shahid Beheshti University of Medical Sciences Research Center for Gastroenterology and Liver Diseases were used for prediction and comparative study of the base and ensemble data mining techniques. Feature selection methods were used to select predictor attributes for classification. The WEKA toolkit and MedCalc software were respectively utilized for creating and comparing the models. The obtained results showed that the predictive performance of developed models was altogether high (all greater than 90%). Overall, the performance of ensemble models was higher than that of basic classifiers and the best result achieved by ensemble voting model in terms of area under the ROC curve (AUC= 0.96). AUC Comparison of models showed that the ensemble voting method significantly outperformed all models except for two methods of Random Forest (RF) and Bayesian Network (BN) considered the overlapping 95% confidence intervals. This result may indicate high predictive power of these two methods along with ensemble voting for predicting 5-year survival of CRC patients.
Technology-based vs. traditional instruction. A comparison of two methods for teaching the skill of performing a 12-lead ECG.

PubMed

Jeffries, Pamela R; Woolf, Shirley; Linde, Beverly

2003-01-01

The purpose of this study was to compare the effectiveness of an interactive, multimedia CD-ROM with traditional methods of teaching the skill of performing a 12-lead ECG. A randomized pre/posttest experimental design was used. Seventy-seven baccalaureate nursing students in a required, senior-level critical-care course at a large midwestern university were recruited for the study. Two teaching methods were compared. The traditional method included a self-study module, a brief lecture and demonstration by an instructor, and hands-on experience using a plastic manikin and a real 12-lead ECG machine in the learning laboratory. The second method covered the same content using an interactive, multimedia CD-ROM embedded with virtual reality and supplemented with a self-study module. There were no significant (p < .05) baseline differences in pretest scores between the two groups and no significant differences by group in cognitive gains, student satisfaction with their learning method, or perception of self-efficacy in performing the skill. Overall results indicated that both groups were satisfied with their instructional method and were similar in their ability to demonstrate the skill correctly on a live, simulated patient. This evaluation study is a beginning step to assess new and potentially more cost-effective teaching methods and their effects on student learning outcomes and behaviors, including the transfer of skill acquisition via a computer simulation to a real patient.
All-Systolic Non-ECG-gated Myocardial Perfusion MRI: Feasibility of Multi-Slice Continuous First-Pass Imaging

PubMed Central

Sharif, Behzad; Arsanjani, Reza; Dharmakumar, Rohan; Bairey Merz, C. Noel; Berman, Daniel S.; Li, Debiao

2015-01-01

Purpose To develop and test the feasibility of a new method for non-ECG-gated first-pass perfusion (FPP) cardiac MR capable of imaging multiple short-axis slices at the same systolic cardiac phase. Methods A magnetization-driven pulse sequence was developed for non-ECG-gated FPP imaging without saturation-recovery preparation using continuous slice-interleaved radial sampling. The image reconstruction method, dubbed TRACE, employed self-gating based on reconstruction of a real-time image-based navigator combined with reference-constrained compressed sensing. Data from ischemic animal studies (n=5) was used in a simulation framework to evaluate temporal fidelity. Healthy subjects (n=5) were studied using both the proposed and conventional method to compare the myocardial contrast-to-noise ratio (CNR). Patients (n=2) underwent adenosine stress studies using the proposed method. Results Temporal fidelity of the developed method was shown to be sufficient at high heart-rates. The healthy volunteers studies demonstrated normal perfusion and no artifacts. Compared to the conventional scheme, myocardial CNR for the proposed method was slightly higher (8.6±0.6 vs. 8.0±0.7). Patient studies showed stress-induced perfusion defects consistent with invasive angiography. Conclusions The presented methods and results demonstrate feasibility of the proposed approach for high-resolution non-ECG-gated FPP imaging and indicate its potential for achieving desirable image quality (high CNR, no dark-rim artifacts) with a 3-slice spatial coverage, all imaged at the same systolic phase. PMID:26052843
Comparative Study of Hand-Sutured versus Circular Stapled Anastomosis for Gastrojejunostomy in Laparoscopy Assisted Distal Gastrectomy

PubMed Central

Seo, Su Hyun; Kim, Min Chan; Choi, Hong Jo; Jung, Ghap Joong

2012-01-01

Purpose Mechanical stapler is regarded as a good alternative to the hand sewing technique, when used in gastric reconstruction. The circular stapling method has been widely applied to gastrectomy (open orlaparoscopic), for gastric cancer. We illustrated and compared the hand-sutured method to the circular stapling method, for Billroth-II, in patients who underwent laparoscopy assisted distal gastrectomy for gastric cancer. Materials and Methods Between April 2009 and May 2011, 60 patients who underwent laparoscopy assisted distal gastrectomy, with Billroth-II, were enrolled. Hand-sutured Billroth-II was performed in 40 patients (manual group) and circular stapler Billroth-II was performed in 20 patients (stapler group). Clinicopathological features and post-operative outcomes were evaluated and compared between the two groups. Results Nosignificant differences were observed in clinicopathologic parameters and post-operative outcomes, except in the operation times. Operation times and anastomosis times were significantly shorter in the stapler group (P=0.004 and P<0.001). Conclusions Compared to the hand-sutured method, the circular stapling method can be applied safely and more efficiently, when performing Billroth-II anastomosis, after laparoscopy assisted distal gastrectomy in patients with gastric cancer. PMID:22792525
A propensity score approach to correction for bias due to population stratification using genetic and non-genetic factors.

PubMed

Zhao, Huaqing; Rebbeck, Timothy R; Mitra, Nandita

2009-12-01

Confounding due to population stratification (PS) arises when differences in both allele and disease frequencies exist in a population of mixed racial/ethnic subpopulations. Genomic control, structured association, principal components analysis (PCA), and multidimensional scaling (MDS) approaches have been proposed to address this bias using genetic markers. However, confounding due to PS can also be due to non-genetic factors. Propensity scores are widely used to address confounding in observational studies but have not been adapted to deal with PS in genetic association studies. We propose a genomic propensity score (GPS) approach to correct for bias due to PS that considers both genetic and non-genetic factors. We compare the GPS method with PCA and MDS using simulation studies. Our results show that GPS can adequately adjust and consistently correct for bias due to PS. Under no/mild, moderate, and severe PS, GPS yielded estimated with bias close to 0 (mean=-0.0044, standard error=0.0087). Under moderate or severe PS, the GPS method consistently outperforms the PCA method in terms of bias, coverage probability (CP), and type I error. Under moderate PS, the GPS method consistently outperforms the MDS method in terms of CP. PCA maintains relatively high power compared to both MDS and GPS methods under the simulated situations. GPS and MDS are comparable in terms of statistical properties such as bias, type I error, and power. The GPS method provides a novel and robust tool for obtaining less-biased estimates of genetic associations that can consider both genetic and non-genetic factors. 2009 Wiley-Liss, Inc.

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